# Seminar / Colloquium

## Stanford Computer Forum and SystemX Seminar

Topic:
Silicon Engineering at Apple
Abstract / Description:

The last decade has seen massive improvements in mobile compute performance, along with dramatic improvements in power efficiency. At Apple, custom SoC designs drive multiple product breakthroughs. The CPU inside the Apple A9 chip in iPhone 6s runs up to 70% faster and the GPU up to 90% faster than they did in the A8, delivering both desktop-class and console-class performance that you can hold in your hand. This has all been done without decreasing battery life. In this talk some of the unique technical challenges faced by mobile SoC designers will be discussed, along with some of the complex decisions that are considered when engineering silicon at Apple.

Light refreshments will be provided following the talk. Students seeking permanent or intern positions at Apple are encouraged to bring a resume.

Date and Time:
Tuesday, November 3, 2015 - 4:30pm to 5:30pm
Venue:
Hewlett 200

## Special Seminar

Topic:
Conquering MPSoC Complexity with Bio-Inspired Self-Organization
Abstract / Description:

The complexity of hardware/software systems evolved as THE grand challenge for the effective deployment of multi-/many-core processor platforms in embedded and high performance computing systems. Whether we struggle with MPSoC power, resilience, mixed-criticality guarantees, software debugging or security shortcomings, all these are consequences of the economically driven increase in function integration and growing system complexity. Nature has intriguingly powerful mechanisms to cope with the inherent complexity of living organisms. For example, the visceral nervous and immune systems control vital body functions without conscious involvement. On a higher layer, the somatic nervous system or brain allows cognition, reasoning and learning. Both layers are dominantly founded on the principle of emergent self-organization: system constituents follow few, individual and simple rules which manifest in a desirable overall system behavior (or the opposite, chaotic behavior, which usually is being eliminated in nature through evolution). These principles inspired initiatives like autonomic and organic computing, cognitive sciences and humanoid robotics.

My talk will first provide an overview on the research activities at our institute, which are focused on architectures, accelerators and design methods for application specific MPSoC. I will then show examples for the successful application of self-organization principles on homogeneous MPSoC. Thereby, workload balancing and optimization of power consumption and system resilience were the target objective functions. Evolution, i.e. the identification of efficient local rules and behaviors, is being emulated by means of generic online and hardware-based reinforcement machine learning techniques. I will close with an outlook towards applying these concepts in the contexts of MPSoC diagnosis / software debugging and SDN/NFV (software defined networking/network function virtualization) scaling.

Date and Time:
Monday, November 2, 2015 - 4:30pm to 5:30pm
Venue:
Gates 415

## Invited Talk: GaN Electronics

Topic:
GaN Electronics– the Challenges of Phonons, Electrons and the Sparkling Diamond
Abstract / Description:

GaN electronic devices are presently being developed for microwave and power applications. Many challenges remain in particular how to manage heat and charge carrier trapping. Prof. Kuball will review his latest work in this field, including the benefit of using diamond for thermal heat sinking as well of carbon doping of the GaN and its implication on charge carrier trapping and electrical conduction.

Date and Time:
Monday, October 26, 2015 - 4:00pm to 5:00pm
Venue:
Allen 101X

## SystemX Seminar

Topic:
Cognitive Layering in Embedded Computing
Abstract / Description:

Embedded computing is often computing with extremes – extreme low cost, extreme low energy, extreme low latency, extreme high computation rates. Increasingly, it is about extreme responsiveness, connectedness and intelligence. Systems often need to maintain the energy illusion of "always off" and the computational illusion of "always on". This talk addresses this seeming paradox with the notion of 'cognitive layering', a hierarchy of processing subsystems making widely shifting trade-offs between generality and efficiency. Along the way we touch on key emerging embedded computing functions in vision, convolutional neural networks, ultra-low-power processing and distributed software environments.

Date and Time:
Thursday, October 29, 2015 - 4:30pm to 5:30pm
Venue:
Y2E2 - 111

## Statistics Seminar

Topic:
Sparse Inverse Problems
Abstract / Description:

We present an efficient algorithm and theoretical analysis for an infinite-dimensional analogue of the Lasso.

Compressed sensing seeks to explain an observed signal as the noisy measurement of a few weighted sources. Identifying a weighted collection of parametric sources with a measure on the parameter space allows one to estimate the underlying sources using an infinitedimensional analogue of the Lasso. In many applications the mapping from parameters to observations is differentiable; we propose an algorithm and theoretical analysis that leverages structure in the measurement mapping.

We propose an algorithm that interleaves conditional gradient steps on the infinite-dimensional Lasso with nonconvex local search over the parameter space. We outline applications of our algorithm to super-resolution imaging, low-rank matrix completion, linear system identification, and radiation treatment planning.

We prove that in ideal settings the optimization problem recovers the true parameters. Precisely, we restrict our theoretical analysis to the setting with a one-dimensional parameter space, positive weights, and noiseless observations. We establish conditions on the measurement function such that minimizing the weighted total variation recovers the true parameters and weights, with no minimum separation condition on the source locations

Date and Time:
Tuesday, October 27, 2015 - 4:30pm to 5:30pm
Venue:
Sequoia Hall, Room 200

## Applied Physics/Physics Colloquium

Topic:
Neutrino Oscillations: Past, Present and Future
Abstract / Description:
Neutrino oscillations had been one of the most successful stories in the history of particle physics. I will review the discovery of neutrino oscillation and confirmations afterwards. There are quite a number of neutrino experiments under operation now and many under planning. In particular, I will explain a reactor-based neutrino experiment, Daya Bay, for mixing angle theta-13 and its successor, JUNO experiment for the neutrino mass hierarchy.

Held Tuesdays at 4:30 pm in the William R. Hewlett Teaching Center, room 201.

Refreshments in the lobby of Varian Physics at 4:15 pm.

Autumn 2015/2016, Committee: A, Linde (Chair), S. Chu, P. Hayden, M. Schnitzer, L. Senatore

Date and Time:
Tuesday, November 10, 2015 - 4:30pm to 5:30pm
Venue:
Hewlett 201

## Applied Physics/Physics Colloquium

Topic:
Entanglement and Complexity: Gravity and Quantum Mechanics
Abstract / Description:
I will try to explain how it is that gravity and quantum information theory have come together to create a new way of thinking about physical systems. From fluid dynamics to strange metals to black holes to the foundations of quantum mechanics, almost all areas of physics are being touched by the new paradigm.

Held Tuesdays at 4:30 pm in the William R. Hewlett Teaching Center, room 201.

Refreshments in the lobby of Varian Physics at 4:15 pm.

Autumn 2015/2016, Committee: A, Linde (Chair), S. Chu, P. Hayden, M. Schnitzer, L. Senatore

Date and Time:
Tuesday, November 3, 2015 - 4:30pm to 5:30pm
Venue:
Hewlett 201

## Applied Physics/Physics Colloquium

Topic:
Inside Out: Visualizing Phase Transformations and Light-matter Interactions with Nanometer-scale Resolution
Abstract / Description:

In Pixar's Inside Out, Joy proclaims, "Do you ever look at someone and wonder, what's going on inside?" My group asks the same question about nanomaterials whose function plays a critical role in energy, biology, and information-relevant processes. In this presentation, I will describe new techniques that enable visualization of nanoparticle phase transitions and light-matter interactions with nanometer-scale resolution. First, we explore nanomaterial phase transitions induced by solute intercalation, to understand and improve materials for energy storage applications. As a model system, we investigate hydrogen absorption and desorption in individual palladium nanocrystals. Our approach is based on in-situ electron energy-loss spectroscopy in an environmental transmission electron microscope. By probing hydrogen-induced shifts of the palladium plasmon resonance, we find that sub-30nm single-crystalline nanoparticles do not exhibit phase-coexistence and that surface effects dictate the size dependence of the ​hydrogen absorption pressures. Then, we introduce a novel tomographic technique, cathodoluminescence spectroscopic tomography, to probe optical properties in three dimensions with nanometer-scale spatial and spectral resolution. Particular attention is given to reconstructing a 3D metamaterial resonator supporting broadband electric and magnetic resonances at optical frequencies. Our tomograms allow us to locate regions of efficient cathodoluminescence across visible and near-infrared wavelengths, with contributions from material luminescence and radiative decay of electromagnetic eigenmodes. This tomographic technique could be used to precisely locate radiative recombination centers in light-emitting diodes, to probe the nanoscale distribution of defect states in organic photovoltaics, and potentially to provide new label-free avenues for biological imaging. Taken together, our results provide a general framework for high-resolution visualization of chemical reactions and light-matter interactions, well-below the diffraction limit and in three-dimensions.

Held Tuesdays at 4:30 pm in the William R. Hewlett Teaching Center, room 201.

Refreshments in the lobby of Varian Physics at 4:15 pm.

Autumn 2015/2016, Committee: A, Linde (Chair), S. Chu, P. Hayden, M. Schnitzer, L. Senatore

Date and Time:
Tuesday, October 27, 2015 - 4:30pm to 5:30pm
Venue:
Hewlett 201

## EE380 Computer Systems Colloquium

Topic:
'IPFS: The Distributed, Permanent Web' or 'How I learned to Stop Worrying and Love the Merkle Web'
Abstract / Description:

The InterPlanetary File System (IPFS) is a new hypermedia distribution protocol, to complement – and eventually replace – HTTP. It improves the security, performance, operation modes, and data friendliness of the Web. In particular, it yields a powerful new model, where websites and web applications are decoupled from origin servers, are distributed trustlessly through the network, and are encrypted, authenticated, and executed safely.

Important properties include:

• immutable content-addressed graph (merkle dag, git, sfsro)
• mutable key-addressed name system (sfs-inspired)
• transport-agnosticism and clean protocol layering
• files are an abstraction on top of the merkle dag
• flexible graph data model (both json and xml friendly)
• clean layering on the web - works with today's browsers.
• clean layering on unix - can mount the web in the OS FS
• usable in IoT and other untraditional cases

This talk will cover:

1. the major problems plaguing today's web,
2. the architecture of IPFS (how it fits in the network stack, how it is deployed, how the problems are solved)
3. powerful new models for the web (distributed, offline-first, authenticated)
4. examples of important use cases (package managers, OSes, archives)
5. a discussion on open source protocol R & D
6. future research, development, and deployment directions

The talk will include a broad look at The IPFS Project, and a discussion on evolving the network stack through open source protocols R & D.
Today, IPFS is classified as alpha software, yet it is robust enough to be in use even in production.

Most notable related work includes: SFS, BitTorrent, Git, Bitcoin, CCNx/NDN, GNUnet, Freenet, Tahoe-LAFS.

Date and Time:
Wednesday, October 21, 2015 - 4:30pm to 5:30pm
Venue:
Gates B03

## EE380 Computer Systems Colloquium

Topic:
Progress Toward Wafer-Scale Thermionic Energy Conversion
Abstract / Description:

Thermionic energy converters (TECs) were conceived in 1915, demonstrated in 1939, and were the focus of huge investments during the Cold War by the U.S. and the Soviet Union. A 6 kW thermionic converter, fabricated using precision machining technology, was flown in 1987 by the Soviet Union. TEC research ramped down in the 1990s and the field withered to a few embers by 2005. I will review the simple physics of TECs and what the barriers have been to applying them to direct heat-to-electricity conversion for terrestrial applications.

Over the past decade, new materials, processes, and device architectures are being explored at Stanford, the Max Planck Institute, and other research groups around the world. I will provide an update on recent progress at Stanford on thermally isolated, suspended micro cathodes inspired by microbolometer infrared imagers. In order to reach useful efficiencies, both very high thermal isolation between the cathode and the anode and a much lower anode work function are needed. Over the past year, two approaches to fabricating anodes with work functions of 1 eV or less have been demonstrated at Stanford: the electrostatic doping of graphene and the surface photovoltage in a semiconductor anode.

Date and Time:
Wednesday, October 14, 2015 - 4:30pm to 5:30pm
Venue:
Gates B03

## Applied Physics/Physics Colloquium: Quantum mechanical bounds on transport and chaos

Topic:
Quantum mechanical bounds on transport and chaos
Abstract / Description:

Transport in strongly quantum systems is challenging to understand. I will describe a recently obtained bound on transport in terms of a characteristic quantum velocity (the Lieb-Robinson velocity) and the local thermalization time. This bound sheds some light on experiments in both condensed matter systems and ultracold atomic gases. At finite temperatures, a more powerful velocity is the so-called butterfly velocity, that is intimately related to quantum chaos. This velocity is still poorly understood; I will present some forthcoming results that constrain the temperature dependence of the butterfly velocity in terms of the underlying quantum scrambling of the system.

Date and Time:
Monday, October 8, 2018 - 4:15pm
Venue:
Spilker 232

## Applied Physics/Physics Colloquium

Topic:
TBA
Abstract / Description:

TBA

Aut. Qtr. Colloq. committee: R. Blandford (Chair), A. Kapitulnik, R. Laughlin, L. Senatore
Location: Hewlett Teaching Center, Rm. 200

Date and Time:
Tuesday, November 27, 2018 - 4:30pm
Venue:
Hewlett 200

## Applied Physics/Physics Colloquium: Tentative title: "Searching for Dark Sectors"

Topic:
Tentative title: "Searching for Dark Sectors"
Abstract / Description:

TBA

Aut. Qtr. Colloq. committee: R. Blandford (Chair), A. Kapitulnik, R. Laughlin, L. Senatore
Location: Hewlett Teaching Center, Rm. 200

Date and Time:
Tuesday, November 13, 2018 - 4:30pm
Venue:
Hewlett 200

## Applied Physics/Physics Colloquium

Topic:
TBA
Abstract / Description:

TBA

Aut. Qtr. Colloq. committee: R. Blandford (Chair), A. Kapitulnik, R. Laughlin, L. Senatore
Location: Hewlett Teaching Center, Rm. 200

Date and Time:
Tuesday, November 6, 2018 - 4:30pm
Venue:
Hewlett 200

## Applied Physics/Physics Colloquium

Topic:
TBA
Abstract / Description:

TBA

Aut. Qtr. Colloq. committee: R. Blandford (Chair), A. Kapitulnik, R. Laughlin, L. Senatore
Location: Hewlett Teaching Center, Rm. 200

Date and Time:
Tuesday, October 30, 2018 - 4:30pm
Venue:
Hewlett 200

## Applied Physics/Physics Colloquium: Visiting Newton's Atelier before the Principia, 1679-1684

Topic:
Visiting Newton's Atelier before the Principia, 1679-1684
Abstract / Description:

Newton's Principia ignited the Scientific Revolution, but the work-sheets and sketches showing how he composed his masterpiece have been lost. Fortunately, he left behind enough clues to make it possible to give a plausible reconstruction of how he did it. Surprisingly, such a reconstruction has not been attempted before. In the winter of 1679, Robert Hooke initiated a correspondence with Newton outlining the physics of planetary motion. But Hooke was unable to formulate his concepts in mathematical form, and afterward, Newton accomplished this formulation, which allowed him to give a geometrical expression for the passage of time, thus laying the foundations for the Principia. On Dec.10, 1684, four months after a visit of Edmond Halley, Newton sent the first manuscripts for the Principia to the London Royal Society, which he had made "designedly abstruse to be understood only by able Mathematicians". This lack of clarity remains up to the present time. In his talk, I will show, however, that with simply a pencil and a ruler, and without any calculus, good approximations of orbits for central forces can be calculated graphically that also clarify the content of the Principia.

Aut. Qtr. Colloq. committee: R. Blandford (Chair), A. Kapitulnik, R. Laughlin, L. Senatore
Location: Hewlett Teaching Center, Rm. 200

Date and Time:
Tuesday, October 23, 2018 - 4:30pm
Venue:
Hewlett 200

## Applied Physics/Physics Colloquium: Botswana to Bolivia - The Life of an Itinerant Science Educator

Topic:
Botswana to Bolivia - The Life of an Itinerant Science Educator
Abstract / Description:

Ranging across Botswana, Bolivia, Nepal, Denmark, The Navajo Nation, and small-town New Jersey, the intricacies of being an international science educator are explored. Does everyone think and communicate as "we" do? How can we maintain our sanity in an increasingly insane world? What are ways that we can best communicate scientific knowledge? These topics are explored in a web of poignant and often humorous anecdotes. The speaker, award-winning educator Phil Deutschle, holds degrees in Physics and Astronomy, is the author of, "The Two-Year Mountain: A Nepal Journey" and "Across African Sand: Journeys of a Witch-Doctor's Son-in-Law," and is the producer of the feature-length documentary, "Searching for Nepal."

Aut. Qtr. Colloq. committee: R. Blandford (Chair), A. Kapitulnik, R. Laughlin, L. Senatore
Location: Hewlett Teaching Center, Rm. 200

Date and Time:
Tuesday, October 16, 2018 - 4:30pm
Venue:
Hewlett 200

## Applied Physics/Physics Colloquium: A High Energy View of the Extreme Universe

Topic:
A High Energy View of the Extreme Universe
Abstract / Description:

In the past 10 years, high energy gamma-ray astrophysics has undergone a renaissance. Dramatically improved capabilities from both ground based and space based observatories have combined to unveil dozens of new classes of gamma-ray emitters among the thousands of new sources, and studied each one with unprecedented spatial and spectral capabilities. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies, gamma-ray bursts and the discovery of transient sources in our galaxy – some with surprising counterparts. In this talk I will review some of the science highlights from the past decade with an emphasis on the surprises and remaining open questions.

Aut. Qtr. Colloq. committee: R. Blandford (Chair), A. Kapitulnik, R. Laughlin, L. Senatore
Location: Hewlett Teaching Center, Rm. 200

Date and Time:
Tuesday, October 9, 2018 - 4:30pm
Venue:
Hewlett 200

## Applied Physics/Physics Colloquium: Photovoltaic Restoration of Sight in Retinal Degeneration

Topic:
Photovoltaic Restoration of Sight in Retinal Degeneration
Abstract / Description:

Retinal degenerative diseases lead to blindness due to loss of the "image capturing" photoreceptors, while neurons in the "image-processing" inner retinal layers are relatively well preserved. Information can be reintroduced into the visual system using electrical stimulation of the surviving inner retinal neurons. Some electronic retinal prosthetic systems have been already approved for clinical use, but they provide low resolution and involve very difficult implantation procedures.

We developed a photovoltaic subretinal prosthesis which converts light into pulsed electric current, stimulating the nearby inner retinal neurons. Visual information is projected onto the retina from video goggles using pulsed near-infrared (~880nm) light. This design avoids the use of bulky electronics and wiring, thereby greatly reducing the surgical complexity. Optical activation of the photovoltaic pixels allows scaling the implants to thousands of electrodes.
In preclinical studies, we found that prosthetic vision with subretinal implants preserves many features of natural vision, including flicker fusion at high frequencies (>20 Hz), adaptation to static images, center-surround organization and non-linear summation of subunits in receptive fields, providing high spatial resolution. Initial results of the clinical trial with our implants (PRIMA, Pixium Vision) having 100mm pixels, as well as preclinical measurements, confirm that spatial resolution of prosthetic vision can reach the sampling density limit.

For a broad acceptance of this technology by millions of patients who lost central vision due to age-related macular degeneration, visual acuity should exceed 20/100, which requires pixels smaller than 25mm. I will describe the fundamental limitations in electro-neural interfaces and 3-dimensional configurations which should enable such a high spatial resolution. Ease of implantation of these wireless modules, combined with high resolution opens the door to highly functional restoration of sight.

Aut. Qtr. Colloq. committee: R. Blandford (Chair), A. Kapitulnik, R. Laughlin, L. Senatore

Location: Hewlett Teaching Center, Rm. 200

Date and Time:
Tuesday, October 2, 2018 - 4:30pm
Venue:
Hewlett 200

## Applied Physics/Physics Colloquium: Nuclear Geochronology and the Age of the Earth

Topic:
Nuclear Geochronology and the Age of the Earth
Abstract / Description:

How Old Is Earth? Because Earth formed by protracted accretion of planetestimals, asking the age of our planet is in some ways akin to asking your friends theirs and in other ways different. While your pals are unlikely to date themselves from the moment of conception, we can use U-Pb dating to pinpoint the arrival of our solar system to the formation of the first solids in primitive meteorites that condensed from the circumstellar disk at 4,567.2±0.5 million years (Ma). The timing of volatile loss from parent bodies constrains Earth to have accreted most of its mass by 4,550 Ma from impactors broadly similar in composition to meteorites but, surprisingly, of a class not yet recognized. Whereas your pals almost certainly know the day they emerged from the womb, the continuous mobility of our planet has erased any vestige of its origin. Clues remain nonetheless. Sixty years ago, Clair Patterson argued that the similarity of Pb isotopes between terrestrial rocks and meteorites established Earth's age as 4550 Ma. While his age was approximately correct, he was right for the wrong reason. Recently, two approaches have more clearly constrained an upper age bound to Earth formation; 182Hf-182W dating of core formation at ca. 4,540 Ma and 176Lu-176Hf data from terrestrial and lunar zircons as old as 4,380 Ma that require primary differentiation on both bodies to have ended by 4,510 Ma. The question of Earth's age remains of societal import as about half the population of our country believes that it is less than 10,000 years old and arose in the fashion described in Genesis. But creationists are not alone in promulgating origin myths. In the absence of any empirical evidence, the scientific community long coalesced around the view that the first (~500 Ma) of Earth history saw a continuously molten surface disrupted only by extraterrestrial impacts. Those ancient zircons noted above are seriously challenging that longstanding paradigm.

Date and Time:
Tuesday, September 25, 2018 - 4:30pm
Venue:
Hewlett 200

## Special Seminar: Formal Methods meets Machine Learning: Explorations in Cyber-Physical Systems Design

Topic:
Formal Methods meets Machine Learning: Explorations in Cyber-Physical Systems Design
Abstract / Description:

Cyber-physical systems (CPS) are computational systems tightly integrated with physical processes. Examples include modern automobiles, fly-by-wire aircraft, software-controlled medical devices, robots, and many more. In recent times, these systems have exploded in complexity due to the growing amount of software and networking integrated into physical environments via real-time control loops, as well as the growing use of machine learning and artificial intelligence (AI) techniques. At the same time, these systems must be designed with strong verifiable guarantees.

In this talk, I will describe our research explorations at the intersection of machine learning and formal methods that address some of the challenges in CPS design. First, I will describe how machine learning techniques can be blended with formal methods to address challenges in specification, design, and verification of industrial CPS. In particular, I will discuss the use of formal inductive synthesis --- algorithmic synthesis from examples with formal guarantees — for CPS design. Next, I will discuss how formal methods can be used to improve the level of assurance in systems that rely heavily on machine learning, such as autonomous vehicles using deep learning for perception. Both theory and industrial case studies will be discussed, with a special focus on the automotive domain. I will conclude with a brief discussion of the major remaining challenges posed by the use of machine learning and AI in CPS.

Date and Time:
Monday, December 4, 2017 - 4:00pm
Venue:
Gates 463A

## SpaceX's journey on the road to mars

Topic:
SpaceX's journey on the road to mars
Abstract / Description:

SSI will be hosting Gwynne Shotwell — President and COO of SpaceX — to discuss SpaceX's journey on the road to mars. The event will be on Wednesday Oct 11th from 7pm - 8pm in Dinkelspiel Auditorium. After the talk, there will be a Q&A session hosted by Steve Jurvetson from DFJ Venture Capital.

Claim your tickets now on eventbright

Date and Time:
Wednesday, October 11, 2017 - 7:00pm
Venue:
Dinkelspiel Auditorium

## CS Department Lecture Series (CS300)

Topic:
Faculty speak about their research to new PhD students
Abstract / Description:

Offered to incoming first-year PhD students in the Autumn quarter.

The seminar gives CS faculty the opportunity to speak about their research, which allows new CS PhD students the chance to learn about the professors and their research before permanently aligning.

4:30-5:15, Subhasish Mitra

5:15-6:00, Silvio Savarese

Date and Time:
Wednesday, December 7, 2016 - 4:30pm to 6:00pm
Venue:
200-305 Lane History Corner, Main Quad

## CS Department Lecture Series (CS300)

Topic:
Faculty speak about their research to new PhD students
Abstract / Description:

Offered to incoming first-year PhD students in the Autumn quarter.

The seminar gives CS faculty the opportunity to speak about their research, which allows new CS PhD students the chance to learn about the professors and their research before permanently aligning.

4:30-5:15, Phil Levis

5:15-6:00, Ron Fedkiw

Date and Time:
Monday, December 5, 2016 - 4:30pm to 6:00pm
Venue:
200-305 Lane History Corner, Main Quad

## CS Department Lecture Series (CS300)

Topic:
Faculty speak about their research to new PhD students
Abstract / Description:

Offered to incoming first-year PhD students in the Autumn quarter.

The seminar gives CS faculty the opportunity to speak about their research, which allows new CS PhD students the chance to learn about the professors and their research before permanently aligning.

4:30-5:15, Dan Boneh

5:15-6:00, Aaron Sidford

Date and Time:
Wednesday, November 30, 2016 - 4:30pm to 6:00pm
Venue:
200-305 Lane History Corner, Main Quad

## CS Department Lecture Series (CS300)

Topic:
Faculty speak about their research to new PhD students
Abstract / Description:

Offered to incoming first-year PhD students in the Autumn quarter.

The seminar gives CS faculty the opportunity to speak about their research, which allows new CS PhD students the chance to learn about the professors and their research before permanently aligning.

4:30-5:15, John Mitchell

5:15-6:00, James Zou

Date and Time:
Monday, November 28, 2016 - 4:30pm to 6:00pm
Venue:
200-305 Lane History Corner, Main Quad

## CS Department Lecture Series (CS300)

Topic:
Faculty speak about their research to new PhD students
Abstract / Description:

Offered to incoming first-year PhD students in the Autumn quarter.

The seminar gives CS faculty the opportunity to speak about their research, which allows new CS PhD students the chance to learn about the professors and their research before permanently aligning.

4:30-5:15, Emma Brunskill

5:15-6:00, Doug James

Date and Time:
Wednesday, November 16, 2016 - 4:30pm to 6:00pm
Venue:
200-305 Lane History Corner, Main Quad

## CS Department Lecture Series (CS300)

Topic:
Faculty speak about their research to new PhD students
Abstract / Description:

Offered to incoming first-year PhD students in the Autumn quarter.

The seminar gives CS faculty the opportunity to speak about their research, which allows new CS PhD students the chance to learn about the professors and their research before permanently aligning.

4:30-5:15, James Landay

5:15-6:00, Dan Jurafsky

Date and Time:
Monday, November 14, 2016 - 4:30pm to 6:00pm
Venue:
200-305 Lane History Corner, Main Quad

## CS Department Lecture Series (CS300)

Topic:
Faculty speak about their research to new PhD students
Abstract / Description:

Offered to incoming first-year PhD students in the Autumn quarter.

The seminar gives CS faculty the opportunity to speak about their research, which allows new CS PhD students the chance to learn about the professors and their research before permanently aligning.

4:30-5:15, Ken Salisbury

5:15-6:00, Noah Goodman

Date and Time:
Wednesday, November 9, 2016 - 4:30pm to 6:00pm
Venue:
200-305 Lane History Corner, Main Quad

## CS Department Lecture Series (CS300)

Topic:
Faculty speak about their research to new PhD students
Abstract / Description:

Offered to incoming first-year PhD students in the Autumn quarter.

The seminar gives CS faculty the opportunity to speak about their research, which allows new CS PhD students the chance to learn about the professors and their research before permanently aligning.

4:30-5:15, Kunle Olukotun

5:15-6:00, Jure Leskovec

Date and Time:
Monday, November 7, 2016 - 4:30pm to 6:00pm
Venue:
200-305 Lane History Corner, Main Quad

## EE380 Computer Systems Colloquium: Efficient and Resilient Systems in the Cognitive Era

Topic:
Efficient and Resilient Systems in the Cognitive Era
Abstract / Description:

A focus on energy efficiency in the late CMOS design era, requires extra careful attention to system reliability and resilience to hardware-sourced errors. At the same time, the emergence of AI (cognitive) applications as a key growth segment is quite obvious. This talk will attempt to address the special challenges that next generation AI (or cognitive) systems pose, with a particular focus on next generation cognitive IoT architectures. We will discuss this primarily from the point of view of providing energy-efficient resilience in environments that are likely to have built-in vulnerability to errors. Such uncertainty stems not just from potentially error-prone (late CMOS) hardware designed for extreme efficiency, but also from algorithmic brittleness of the most prevalent forms of machine learning/deep learning (ML/DL) solution strategies today. In that context, we will briefly examine the promise of the Adaptive Swarm Intelligence (ASI) architectural paradigm that we have recently started investigating at IBM Research. This is a form of distributed or decentralized computing applied to the world of mobile cognitive IoT, backed by resilient support from back-end cloud (server) systems. In addition to examining the promises of inherent system architectural scalability and in-field, continuous learning that ASI offers, we will argue (albeit philosophically!) about why this could open the door to new models of self-aware systems that mimic cooperative and conscious problem solving in a human setting.

The Stanford EE Computer Systems Colloquium (EE380) meets on Wednesdays 4:30-5:45 throughout the academic year. Talks are given before a live audience in Room B03 in the basement of the Gates Computer Science Building on the Stanford Campus. The live talks (and the videos hosted at Stanford and on YouTube) are open to the public.

Stanford students may enroll in EE380 to take the Colloquium as a one unit S/NC class. Enrolled students are required to keep and electronic notebook or journal and to write a short, pithy comment about each of the ten lectures and a short free form evaluation of the class in order to receive credit. Assignments are due at the end of the quarter, on the last day of examinations.

EE380 is a video class. Live attendance is encouraged but not required. We (the organizers) feel that watching the video is not a substitute for being present in the classroom. Questions are encouraged.

Many past EE380 talks are available on YouTube, see the EE380 Playlist.

Date and Time:
Wednesday, October 3, 2018 - 4:30pm
Venue:
Gates B03

## EE380 Computer Systems Colloquium: The Case for Learned Index Structures

Topic:
The Case for Learned Index Structures
Abstract / Description:

Indexes are models: a B-Tree-Index can be seen as a model to map a key to the position of a record within a sorted array, a Hash-Index as a model to map a key to a position of a record within an unsorted array, and a BitMap-Index as a model to indicate if a data record exists or not. In this talk, we take this premise and explain how existing database index structures can be replaced with other types of models, which we term learned indexes. The key idea is that a model can learn the sort order or structure of indexed data and use this signal to effectively predict the position or existence of records. We offer theoretical analysis under which conditions learned indexes outperform traditional index structures and we will delve into the challenges in designing learned index structures. Through addressing these challenges, our initial results show that learned indexes are able to outperform cache-optimized B-Trees by up to 70% in speed while saving an order-of-magnitude in memory over several real-world data sets. Finally, we will discuss the broader implications of learned indexes on database design and future directions for the ML for Database Systems research.

The Stanford EE Computer Systems Colloquium (EE380) meets on Wednesdays 4:30-5:45 throughout the academic year. Talks are given before a live audience in Room B03 in the basement of the Gates Computer Science Building on the Stanford Campus. The live talks (and the videos hosted at Stanford and on YouTube) are open to the public.

Stanford students may enroll in EE380 to take the Colloquium as a one unit S/NC class. Enrolled students are required to keep and electronic notebook or journal and to write a short, pithy comment about each of the ten lectures and a short free form evaluation of the class in order to receive credit. Assignments are due at the end of the quarter, on the last day of examinations.

EE380 is a video class. Live attendance is encouraged but not required. We (the organizers) feel that watching the video is not a substitute for being present in the classroom. Questions are encouraged.

Many past EE380 talks are available on YouTube, see the EE380 Playlist.

Date and Time:
Wednesday, October 17, 2018 - 4:30pm
Venue:
Gates B03

## EE380 Computer Systems Colloquium: 2017 Turing Award Recipients on Computer Architecture

Topic:
Computer Architecture
Abstract / Description:

TBA

The Stanford EE Computer Systems Colloquium (EE380) meets on Wednesdays 4:30-5:45 throughout the academic year. Talks are given before a live audience in Room B03 in the basement of the Gates Computer Science Building on the Stanford Campus. The live talks (and the videos hosted at Stanford and on YouTube) are open to the public.

Stanford students may enroll in EE380 to take the Colloquium as a one unit S/NC class. Enrolled students are required to keep and electronic notebook or journal and to write a short, pithy comment about each of the ten lectures and a short free form evaluation of the class in order to receive credit. Assignments are due at the end of the quarter, on the last day of examinations.

EE380 is a video class. Live attendance is encouraged but not required. We (the organizers) feel that watching the video is not a substitute for being present in the classroom. Questions are encouraged.

Many past EE380 talks are available on YouTube, see the EE380 Playlist.

Date and Time:
Wednesday, October 10, 2018 - 4:30pm
Venue:
Gates B03

## EE380 Computer Systems Colloquium: Interactive Autonomy: a human-centered approach for safe interactions

Topic:
Interactive Autonomy: a human-centered approach for safe interactions
Abstract / Description:

Today's society is rapidly advancing towards robotics systems that interact and collaborate with humans, e.g., semi-autonomous vehicles interacting with drivers and pedestrians, medical robots used in collaboration with doctors, or service robots interacting with their users in smart homes. In this talk, I will first discuss interactive autonomy, where we develop algorithms for autonomous systems that influence humans, and further leverage these effects for better safety, efficiency, coordination, and estimation. I will then focus on our efficient active learning methods to build predictive models of humans's preferences by eliciting comparisons from a mixed set of humans, and further analyzing the generalizability and robustness of the learned human models for safe and seamless interaction with robots.

The Stanford EE Computer Systems Colloquium (EE380) meets on Wednesdays 4:30-5:45 throughout the academic year. Talks are given before a live audience in Room B03 in the basement of the Gates Computer Science Building on the Stanford Campus. The live talks (and the videos hosted at Stanford and on YouTube) are open to the public.

Stanford students may enroll in EE380 to take the Colloquium as a one unit S/NC class. Enrolled students are required to keep and electronic notebook or journal and to write a short, pithy comment about each of the ten lectures and a short free form evaluation of the class in order to receive credit. Assignments are due at the end of the quarter, on the last day of examinations.

EE380 is a video class. Live attendance is encouraged but not required. We (the organizers) feel that watching the video is not a substitute for being present in the classroom. Questions are encouraged.

Many past EE380 talks are available on YouTube, see the EE380 Playlist.

Date and Time:
Wednesday, September 26, 2018 - 4:30pm
Venue:
Gates B03

## EE380 Computer Systems Colloquium presents Optional Static Typing for Python

Topic:
Optional Static Typing for Python
Abstract / Description:

Python is a dynamically typed language, and some of its appeal derives from this. Nevertheless, especially for large code bases, it would be nice if a compiler could find type errors before the code is even run. Optional static type checking promises exactly this, and over the past four years we have successfully introduced this feature into Python 3. This talk introduces the type system we've adopted and the syntax used for type annotations, some tips on how to get started with a large existing code base, and our experience using the 'mypy' type checker at Dropbox. The entire system is open source, and has also been adopted by other companies such as Lyft, Quora and Facebook.

Date and Time:
Wednesday, June 6, 2018 - 4:30pm
Venue:
Gates B03

## EE380 Computer Systems Colloquium: Artificial Intelligence: Current and Future Paradigms and Implications

Topic:
Artificial Intelligence: Current and Future Paradigms and Implications
Abstract / Description:

Artificial intelligence has advanced rapidly in the last five years. This talk intends to provide high level answers to questions like:

• What can the evolution of intelligence in the animal kingdom teach us about the evolution of AI?
• How should people who are not AI researchers view the societal transformation that is now underway? What are some of the social, economic, and political implications of this technology as it exists now?
• What will future AI systems likely be capable of, and what are the largest expected impacts of these systems?

The talk will be understandable for non-computer scientists.

Date and Time:
Wednesday, May 30, 2018 - 4:30pm
Venue:
Gates B03

## EE380 Computer Systems Colloquium: Towards theories of single-trial high dimensional neural data analysis

Topic:
Towards theories of single-trial high dimensional neural data analysis
Abstract / Description:

Neuroscience has entered a golden age in which experimental technologies now allow us to record thousands of neurons, over many trials during complex behaviors, yielding large-scale, high dimensional datasets. However, while we can record thousands of neurons, mammalian circuits controlling complex behaviors can contain tens of millions of behaviorally relevant neurons. Thus, despite significant experimental advances, neuroscience remains in a vastly undersampled measurement regime. Nevertheless, a wide array of statistical procedures for dimensionality reduction of multineuronal recordings uncover remarkably insightful, low dimensional neural state space dynamics whose geometry reveals how behavior and cognition emerge from neural circuits. What theoretical principles explain this remarkable success; in essence, how is it that we can understand anything about the brain while recording an infinitesimal fraction of its degrees of freedom?

We present a theory that addresses this question, and test it using neural data recorded from reaching monkeys. Overall, this theory yields a picture of the neural measurement process as a random projection of neural dynamics, conceptual insights into how we can reliably recover neural state space dynamics in such under-sampled measurement regimes, and quantitative guidelines for the design of future experiments. Moreover, it reveals the existence of phase transition boundaries in our ability to successfully decode cognition and behavior on single trials as a function of the number of recorded neurons, the complexity of the task, and the smoothness of neural dynamics. We will also discuss non-negative tensor analysis methods to perform multi-timescale dimensionality reduction and demixing of neural dynamics that reveal how rapid neural dynamics within single trials mediate perception, cognition and action, and how slow changes in these dynamics mediate learning.

Date and Time:
Wednesday, May 2, 2018 - 4:30pm
Venue:
Gates B03

## EE380 Computer Systems Colloquium: The End of Privacy

Topic:
The End of Privacy
Abstract / Description:

A growing proportion of human activities such as social interactions, entertainment, shopping, and gathering information are now mediated by digital devices and services. Such digitally mediated activities can be easily recorded, offering an unprecedented opportunity to study and measure intimate psycho-demographic traits using actual--rather than self-reported--behavior. Our research shows that digital records of behavior, such as samples of text, Tweets, Facebook Likes, web-browsing logs, or even facial images can be used to accurately measure a wide range of traits including personality, intelligence, and political views. Such Big Data assessment has a number of advantages: it does not require participants' active involvement; it can be easily and inexpensively applied to large populations; and it is relatively immune to cheating or misrepresentation. If used ethically, it could revolutionize psychological assessment, marketing, recruitment, insurance, and many other industries. In the wrong hands, however, such methods pose significant privacy risks. In this talk, we will discuss how to reap the benefits of Big Data assessment while avoiding the pitfalls.

Date and Time:
Wednesday, April 11, 2018 - 4:30pm
Venue:
Gates B03

## EE380 Computer Systems Colloquium: The future of low power circuits and embedded intelligence: emerging devices and new design paradigms

Topic:
The future of low power circuits and embedded intelligence: emerging devices and new design paradigms
Abstract / Description:

Circuit and design division at CEA LETI is focusing on innovative architectures and circuits dedicated to digital, imagers, wireless, sensors, power management and embedded software. After a brief overview of adaptive circuits for low power multi-processors and IoT architectures, the talk will detail new technologies opportunities for more flexibility. Digital and mixed-signal architectures using 3D technologies will be presented in the scope of multi-processors activity as well as imagers and neuro-inspired circuits. Also, the integration of non-volatile memories will be shown in the perspective of new architectures for computing. Finally, embedding learning will be addressed to solve power challenges at the edge and in end-devices: some new design approaches will be discussed.

Date and Time:
Wednesday, May 23, 2018 - 4:30pm
Venue:
Gates B03

## EE380 Computer Systems Colloquium: The Future of Wireless Communications Hint: It's not a linear amplifier

Topic:
The Future of Wireless Communications Hint: It's not a linear amplifier
Abstract / Description:

Wireless communications are ubiquitous in the 21 st century--we use them to read the newspaper, talk to our colleagues or children, watch sporting events or other forms of entertainment, and to monitor and control the environment we live ins-- among just a few. This exponentiation of demand for wireless capacity has driven a new era of innovation in this space because spectrum and energy are expensive and constrained resources.

The future of wireless communications will demand leaps in spectrum efficiency, bandwidth efficiency, and power efficiency for successful technology deployments. Key applications that will fundamentally change how we interact with wireless systems and the demands we place on wireless technologies include Dynamic Spectrum Access Networks, massive MIMO, and the evasive unicorn of the "universal handset". While each of these breakthrough "system" capabilities make simultaneous demands of spectrum efficiency, bandwidth efficiency, and power efficiency, the current suite of legacy technologies forces system designers to make undesirable trade-offs because of the limitations of linear amplifier technology.

Eridan's solution is the antithesis of "linear". The Switch Mode Mixer Modulator (SMs3 ) technology emphasizes precision and flexibility, and simultaneously delivers spectrum efficiency, bandwidth efficiency, and power efficiency. The resulting capabilities dramatically increase total wireless capacity with minimum need for expanding operations into extended regions of the wireless spectrum.

This presentation will discuss the driving forces behind wireless system performance, the physics of linear amplifiers and SM3, measured performance of SM3 systems, and the implications for wireless system capabilities in the near future.

Date and Time:
Wednesday, May 16, 2018 - 4:30pm
Venue:
Gates B03

## AP483, Ginzton Lab, & AMO Seminar Series

Topic:
TBA
Abstract / Description:

Academic year 2018-2019, please join us at Spilker room 232 every Monday afternoon from 4 pm for the AP 483 & Ginzton Lab, and AMO Seminar Series.

Refreshments begin at 4 pm, seminar at 4:15 pm.

Date and Time:
Monday, December 3, 2018 - 4:15pm
Venue:
Spilker 232

## AP483, Ginzton Lab, & AMO Seminar Series

Topic:
TBA
Abstract / Description:

Academic year 2018-2019, please join us at Spilker room 232 every Monday afternoon from 4 pm for the AP 483 & Ginzton Lab, and AMO Seminar Series.

Refreshments begin at 4 pm, seminar at 4:15 pm.

Date and Time:
Monday, November 26, 2018 - 4:15pm
Venue:
Spilker 232

## AP483, Ginzton Lab, & AMO Seminar Series

Topic:
When quantum-information scrambling met quasiprobabilities
Abstract / Description:

Academic year 2018-2019, please join us at Spilker room 232 every Monday afternoon from 4 pm for the AP 483 & Ginzton Lab, and AMO Seminar Series.

Refreshments begin at 4 pm, seminar at 4:15 pm.

Date and Time:
Monday, November 12, 2018 - 4:15pm
Venue:
Spilker 232

## AP483, Ginzton Lab, & AMO Seminar Series

Topic:
TBA
Abstract / Description:

Academic year 2018-2019, please join us at Spilker room 232 every Monday afternoon from 4 pm for the AP 483 & Ginzton Lab, and AMO Seminar Series.

Refreshments begin at 4 pm, seminar at 4:15 pm.

Date and Time:
Monday, October 29, 2018 - 4:15pm
Venue:
Spilker 232

## AP483, Ginzton Lab, & AMO Seminar Series

Topic:
New opportunities with old photonic materials
Abstract / Description:

Lithium niobate (LN) is an "old" material with many applications in optical and microwave technologies, owing to its unique properties that include large second order nonlinear susceptibility, large piezoelectric response, and wide optical transparency window. Conventional LN components, including modulators and periodically polled frequency converters, have been the workhorse of the optoelectronic industry. They are reaching their limits, however, as they rely on weakly guiding ion-diffusion defined optical waveguides in bulk LN crystal. I will discuss our efforts aimed at the development of integrated LN platform, featuring sub-wavelength scale light confinement and dense integration of optical and electrical components, that has the potential to revolutionize optical communication networks and microwave photonic systems, as well as enable realization of quantum photonic circuits. Good example is our recently demonstrated integrated LN electro-optic modulator that can be driven directly by a CMOS circuit, that supports data rates > 200 gigabits per second with > 90% optical transmission efficiency. I will also discuss our work on ultra-high Q LN optical cavities (Q ~ 10,000,000) and their applications, as well as nonlinear wavelength conversion using different approaches based on LN films.
Diamond is another "old" material with remarkable properties! It is transparent from the ultra-violet to infrared, has a high refractive index, strong optical nonlinearity and a wide variety of light-emitting defects of interest for quantum communication and computation. In my talk, I will summarize our efforts towards the development of integrated diamond quantum photonics platform aimed at realization of efficient photonic and phononic interfaces for diamond spin qubits.

Academic year 2018-2019, please join us at Spilker room 232 every Monday afternoon from 4 pm for the AP 483 & Ginzton Lab, and AMO Seminar Series.

Refreshments begin at 4 pm, seminar at 4:15 pm.

Date and Time:
Monday, October 22, 2018 - 4:15pm
Venue:
Spilker 232

## AP483, Ginzton Lab, & AMO Seminar Series presents Dynamic photonic structures

Topic:
Dynamic photonic structures: non-reciprocity, gauge potential, and synthetic dimensions.
Abstract / Description:

We show that dynamic photonic structures, where refractive index of the structure is modulated as a function of time, offers a wide ranges of possibilities for exploration of physics and applications of light. In particular, dynamic photonic structures naturally break reciprocity. With proper design such photonic structure can then be used to achieve complete optical isolation and to completely reproduce magneto-optical effects without the use of gyrotropic materials. Moreover, the phase of the modulation corresponds to an effective magnetic gauge potential for photons, through which one can explore a wide variety of fundamental physics effects of synthetic magnetic field using photons. Finally, such dynamic photonic structure can be used to explore physics, especially topological physics, in dimensions that are higher than the physical dimension of the structure, leading to intriguing possibilities in manipulation of the frequencies of light in non-trivial ways.

Academic year 2018-2019, please join us at Spilker room 232 every Monday afternoon from 4 pm for the AP 483 & Ginzton Lab, and AMO Seminar Series.

Refreshments begin at 4 pm, seminar at 4:15 pm.

Date and Time:
Monday, October 15, 2018 - 4:15pm
Venue:
Spilker 232

## New Directions in Management Science & Engineering: A Brief History of the Virtual Lab

Topic:
New Directions in Management Science & Engineering: A Brief History of the Virtual Lab
Abstract / Description:

Lab experiments have long played an important role in behavioral science, in part because they allow for carefully designed tests of theory, and in part because randomized assignment facilitates identification of causal effects. At the same time, lab experiments have traditionally suffered from numerous constraints (e.g. short duration, small-scale, unrepresentative subjects, simplistic design, etc.) that limit their external validity. In this talk I describe how the web in general—and crowdsourcing sites like Amazon's Mechanical Turk in particular—allow researchers to create "virtual labs" in which they can conduct behavioral experiments of a scale, duration, and realism that far exceed what is possible in physical labs. To illustrate, I describe some recent experiments that showcase the advantages of virtual labs, as well as some of the limitations. I then discuss how this relatively new experimental capability may unfold in the future, along with some implications for social and behavioral science.

Date and Time:
Thursday, March 16, 2017 - 12:15pm
Venue:
Packard 101

## Claude E. Shannon's 100th Birthday

Topic:
Centennial year of the 'Father of the Information Age'
Abstract / Description:

From UCLA Shannon Centennial Celebration website:

Claude Shannon was an American mathematician, electrical engineer, and cryptographer known as "the father of information theory". Shannon founded information theory and is perhaps equally well known for founding both digital computer and digital circuit design theory. Shannon also laid the foundations of cryptography and did basic work on code breaking and secure telecommunications.

Events taking place around the world are listed at IEEE Information Theory Society.

Date and Time:
Saturday, April 30, 2016 - 12:00pm
Venue:
N/A

## Ginzton Lab / AMO Seminar

Topic:
2D/3D Photonic Integration Technologies for Arbitrary Optical Waveform Generation in Temporal, Spectral, and Spatial Domains
Abstract / Description:

Beginning Academic year 2015-2016, please join us at Spilker room 232 every Monday afternoon from 4 pm for the AP 483 & Ginzton Lab, and AMO Seminar Series.

Refreshments begin at 4 pm, seminar at 4:15 pm.

Date and Time:
Monday, February 29, 2016 - 4:15pm to 5:15pm
Venue:
Spilker 232

## Ginzton Lab / AMO Seminar

Topic:
Silicon-Plus Photonics for Tomorrow's (Astronomically) Large-Scale Networks
Abstract / Description:

Beginning Academic year 2015-2016, please join us at Spilker room 232 every Monday afternoon from 4 pm for the AP 483 & Ginzton Lab, and AMO Seminar Series.

Refreshments begin at 4 pm, seminar at 4:15 pm.

Date and Time:
Monday, February 22, 2016 - 4:15pm to 5:15pm
Venue:
Spilker 232

## ISL Colloquium: Battling Demons in Peer Review

Topic:
New Battling Demons in Peer Review
Abstract / Description:

Peer review is the backbone of scholarly research. It is however faced with a number of challenges (or "demons") such as subjectivity, bias/miscalibration, noise, and strategic behavior. The growing number of submissions in many areas of research such as machine learning has significantly increased the scale of these demons. This talk will present some principled and practical approaches to battle these demons in peer review:

(1) Subjectivity: How to ensure that all papers are judged by the same yardstick?

(2) Bias/miscalibration: How to use ratings in presence of arbitrary or adversarial miscalibration?

(3) Noise: How to assign reviewers to papers to simultaneously ensure fair and accurate evaluations in the presence of review noise?

(4) Strategic behavior: How to insulate peer review from strategic behavior of author-reviewers?

The work uses tools from statistics and learning theory, social choice theory, information theory, game theory and decision theory. (No prior knowledge on these topics will be assumed.)

The Information Theory Forum (IT-Forum) at Stanford ISL is an interdisciplinary academic forum which focuses on mathematical aspects of information processing. With a primary emphasis on information theory, we also welcome researchers from signal processing, learning and statistical inference, control and optimization to deliver talks at our forum. We also warmly welcome industrial affiliates in the above fields. The forum is typically held in Packard 202 every Thursday at 4:15 pm during the academic year.

The Information Theory Forum is organized by graduate students Martin Zhang, Farzan Farnia, and Zhengyuan Zhou. To suggest speakers, please contact any of the students.

Date and Time:
Thursday, October 25, 2018 - 4:15pm
Venue:
Packard 202

## ISL Colloquium: New Breakthroughs in Scheduling Theory

Topic:
New Breakthroughs in Scheduling Theory
Abstract / Description:

Scheduling policies are at the heart of computer systems. The right scheduling policy can dramatically reduce response times, ensure fairness, provide class-based priority, etc., without requiring additional resources. While stochastic response time analysis of different scheduling policies has been the focus of thousands of theoretical papers, results are limited to analyzing a relatively small number of "simple" scheduling policies.

In this talk, we introduce the SOAP class of scheduling policies: Schedule Ordered by Age-based Priority. The SOAP policies include almost all scheduling policies in the literature as well as an infinite number of variants which have never been analyzed, or maybe even conceived. SOAP policies include the highly intractable SERPT policy (Shortest-Expected-Remaining-Processing-Time), as well as the famously complex Gittins Index policy. SOAP also includes all sorts of "combination" policies, like a policy that performs Shortest-Job-First on jobs with known size and Foreground-Background scheduling on jobs with unknown size, or a policy that is allowed to preempt jobs only when they hit certain ages. In this talk we present a stochastic response time analysis of all SOAP policies via a single universal framework.

Joint work with: Ziv Scully and Alan Scheller-Wolf

Appeared in ACM SIGMETRICS/POMACS 2018. APS 2018 Best Student Paper Finalist.

The Information Theory Forum (IT-Forum) at Stanford ISL is an interdisciplinary academic forum which focuses on mathematical aspects of information processing. With a primary emphasis on information theory, we also welcome researchers from signal processing, learning and statistical inference, control and optimization to deliver talks at our forum. We also warmly welcome industrial affiliates in the above fields. The forum is typically held in Packard 202 every Thursday at 4:15 pm during the academic year.

The Information Theory Forum is organized by graduate students Martin Zhang, Farzan Farnia, and Zhengyuan Zhou. To suggest speakers, please contact any of the students.

Date and Time:
Thursday, October 11, 2018 - 4:15pm
Venue:
Packard 202

## General Strong Polarization

Topic:
General Strong Polarization
Abstract / Description:

A martingale is a sequence of random variables that maintain their future expected value conditioned
on the past. A [0,1]-bounded martingale is said to polarize if it converges in the limit to either 0
or 1 with probability 1. A martingale is said to polarize strongly, if in t steps it is
sub-exponentially close to its limit with all but exponentially small probability. In 2008, Arikan
built a powerful class of error-correcting codes called Polar codes. The essence of his theory
associates a martingale with every invertible square matrix over a field (and a channel) and showed
that polarization of the martingale leads to a construction of codes that converge to Shannon
capacity. In 2013, Guruswami and Xia, and independently Hassani et al. showed that strong
polarization of the Arikan martingale leads to codes that converge to Shannon capacity at finite
block lengths, specifically at lengths that are inverse polynomial in the gap to capacity, thereby
resolving a major mathematical challenge associated with the attainment of Shannon capacity.

We show that a simple necessary condition for an invertible matrix to polarize over any non-trivial
channel is also sufficient for strong polarization over all symmetric channels over all prime
fields. Previously the only matrix which was known to polarize strongly was the 2×2Hadamard matrix.
In addition to the generality of our result, it also leads to arguably simpler proofs. The essence
of our proof is a local definition'' of polarization which only restricts the evolution of the
martingale in a single step, and a general theorem showing the local polarization suffices for
strong polarization.

In this talk I will introduce polarization and polar codes and, time permitting, present a full
proof of our main theorem. No prior background on polar codes will be assumed.

Based on joint work with Jaroslaw Blasiok, Venkatesan Guruswami, Preetum Nakkiran and Atri Rudra.

Date and Time:
Friday, October 5, 2018 - 3:00pm
Venue:
Gates 463A

## ISL Colloquium: A Differential View of Reliable Communications

Topic:
A Differential View of Reliable Communications
Abstract / Description:

This talk introduces a "differential" approach to information theory. In contrast to the more traditional "elemental" approach, in which we work to understand communication networks by studying the behavior of their elements in isolation, the differential approach works to understand the impact components can have on the larger networks in which they are employed. Results achieved through this differential viewpoint highlight some startling facts about network communications -- including both opportunities where even very small changes to a communication network can have a big impact on network performance and vulnerabilities where small failures can cause big harm.

Date and Time:
Thursday, May 31, 2018 - 4:15pm
Venue:
Packard 101

## ISL Colloquium: Finite Sample Guarantees for Control of an Unknown Linear Dynamical System

Topic:
Finite Sample Guarantees for Control of an Unknown Linear Dynamical System
Abstract / Description:

In principle, control of a physical system is accomplished by first deriving a faithful model of the underlying dynamics from first principles, and then solving an optimal control problem with the modeled dynamics. In practice, the system may be too complex to precisely characterize, and an appealing alternative is to instead collect trajectories of the system and fit a model of the dynamics from the data. How many samples are needed for this to work? How sub-optimal is the resulting controller?

In this talk, I will shed light on these questions when the underlying dynamical system is linear and the control objective is quadratic, a classic optimal control problem known as the Linear Quadratic Regulator. Despite the simplicity of linear dynamical systems, deriving finite-time guarantees for both system identification and controller performance is non-trivial. I will first talk about our results in the "one-shot" setting, where measurements are collected offline, a model is estimated from the data, and a controller is synthesized using the estimated model with confidence bounds. Then, I will discuss our recent work on guarantees in the online regret setting, where noise injected into the system for learning the dynamics needs to trade-off with state regulation.

This talk is based on joint work with Sarah Dean, Horia Mania, Nikolai Matni, and Benjamin Recht.

Date and Time:
Thursday, May 24, 2018 - 4:15pm
Venue:
Packard 101

## ISL Colloquium & IT Forum: Random initialization and implicit regularization in nonconvex statistical estimation

Topic:
Random initialization and implicit regularization in nonconvex statistical estimation
Abstract / Description:

Recent years have seen a flurry of activities in designing provably efficient nonconvex procedures for solving statistical estimation / learning problems. Due to the highly nonconvex nature of the empirical loss, state-of-the-art procedures often require suitable initialization and proper regularization (e.g. trimming, regularized cost, projection) in order to guarantee fast convergence. For vanilla procedures such as gradient descent, however, prior theory is often either far from optimal or completely lacks theoretical guarantees.

This talk is concerned with a striking phenomenon arising in two nonconvex problems (i.e. phase retrieval and matrix completion): even in the absence of careful initialization, proper saddle escaping, and/or explicit regularization, gradient descent converges to the optimal solution within a logarithmic number of iterations, thus achieving near-optimal statistical and computational guarantees at once. All of this is achieved by exploiting the statistical models in analyzing optimization algorithms, via a leave-one-out approach that enables the decoupling of certain statistical dependency between the gradient descent iterates and the data. As a byproduct, for noisy matrix completion, we demonstrate that gradient descent achieves near-optimal entrywise error control.

Date and Time:
Wednesday, May 23, 2018 - 4:15pm
Venue:
Building 370

## ISL Colloquium: Low-dimensional Structures and Deep Models for High-dimensional Data

Topic:
Low-dimensional Structures and Deep Models for High-dimensional Data
Abstract / Description:

In this talk, we will discuss a class of models and techniques that can effectively model and extract rich low-dimensional structures in high-dimensional data such as images and videos, despite nonlinear transformation, gross corruption, or severely compressed measurements. This work leverages recent advancements in convex optimization from Compressive Sensing for recovering low-rank or sparse signals that provide both strong theoretical guarantees and efficient and scalable algorithms for solving such high-dimensional combinatorial problems. We illustrate how these new mathematical models and tools could bring disruptive changes to solutions to many challenging tasks in computer vision, image processing, and pattern recognition. We will also illustrate some emerging applications of these tools to other data types such as 3D range data, web documents, image tags, bioinformatics data, audio/music analysis, etc. Throughout the talk, we will discuss strong connections of algorithms from Compressive Sensing with other popular data-driven methods such as Deep Neural Networks, providing some new perspectives to understand Deep Learning.

This is joint work with John Wright of Columbia, Emmanuel Candes of Stanford, Zhouchen Lin of Peking University, Shenghua Gao of ShanghaiTech, and my former students Zhengdong Zhang of MIT, Xiao Liang of Tsinghua University, Arvind Ganesh, Zihan Zhou, Kerui Min of UIUC.

Date and Time:
Thursday, May 3, 2018 - 4:15pm
Venue:
Packard 101

## ISL Colloquium: Reinforcement Learning: Hidden Theory, and New Super-Fast Algorithms

Topic:
Reinforcement Learning: Hidden Theory, and New Super-Fast Algorithms
Abstract / Description:

Stochastic Approximation algorithms are used to approximate solutions to fixed point equations that involve expectations of functions with respect to possibly unknown distributions. The most famous examples today are TD- and Q-learning algorithms. The first half of this lecture will provide an overview of stochastic approximation, with a focus on optimizing the rate of convergence. A new approach to optimize the rate of convergence leads to the new Zap Q-learning algorithm. Analysis suggests that its transient behavior is a close match to a deterministic Newton-Raphson implementation, and numerical experiments confirm super fast convergence.

Date and Time:
Tuesday, May 1, 2018 - 4:30pm
Venue:
Packard 101

## ISL Seminar: Inventing Algorithms via Deep Learning

Topic:
Inventing Algorithms via Deep Learning
Abstract / Description:

Deep learning is a part of daily life, owing to its successes in computer vision and natural language processing. In these applications, the success of the model-free deep learning approach can be attributed to a lack of (mathematical) generative model. In yet other applications, the data is generated by a simple model and performance criterion mathematically precise and training/test samples infinitely abundant, but the space of algorithmic choices is enormous (example: chess). Deep learning has recently shown strong promise in these problems too (example: alphazero). In this talk, we study two canonical problems of great scientific and engineering interest through the lens of deep learning.

The first is reliable communication over noisy media where we successfully revisit classical open problems in information theory; we show that creatively trained and architected neural networks can beat state of the art on the AWGN channel with noisy feedback by a 100 fold improvement in bit error rate.

The second is optimization and classification problems on graphs, where the key algorithmic challenge is scalable performance to arbitrary sized graphs. Representing graphs as randomized nonlinear dynamical systems via recurrent neural networks, we show that creative adversarial training allows one to train on small size graphs and test on much larger sized graphs (100~1000x) with approximation ratios that rival state of the art on a variety of optimization problems across the complexity theoretic hardness spectrum.

Apart from the obvious practical value, this study of mathematically precise problems sheds light on the mysteries of deep learning methods: training example choices, architectural design decisions and loss function/learning methodologies. Our (mostly) empirical research is conducted under the backdrop of a theoretical research program of understanding gated neural networks (eg: attention networks, GRU, LSTM); we show the first provably (globally) consistent algorithms to recover the parameters of a classical gated neural network architecture: mixture of experts (MoE).

Date and Time:
Thursday, April 26, 2018 - 4:15pm
Venue:
Packard 101

## ISL Colloquium: Reinforcement Learning without Reinforcement

Topic:
Reinforcement Learning without Reinforcement
Abstract / Description:

Reinforcement Learning (RL) is concerned with solving sequential decision-making problems in the presence of uncertainty. RL is really about two problems together. The first is the 'Bellman problem': Finding the optimal policy given the model, which may involve large state spaces. Various approximate dynamic programming and RL schemes have been developed, but either there are no guarantees, or not universal, or rather slow. In fact, most RL algorithms have become synonymous with stochastic approximation (SA) schemes that are known to be rather slow. This is an even more difficult problem for MDPs with continuous state (and action) spaces. We present a class of non-SA algorithms for reinforcement learning in continuous state space MDP problems based on 'empirical' ideas, which are simple, effective and yet universal with probabilistic guarantees. The idea involves randomized Kernel-based function fitting combined with 'empirical' updates. The key is the first known "probabilistic contraction analysis" method we have developed for analysis of fairly general stochastic iterative algorithms, wherein we show convergence to a probabilistic fixed point of a sequence of random operators via a stochastic dominance argument.

The second RL problem is the 'online learning (or the Lai-Robbins) problem' when the model itself is unknown. We propose a simple posterior sampling-based regret-minimization reinforcement learning algorithm for MDPs. It achieves O(sqrt{T})-regret which is order-optimal. It not only optimally manages the "exploration versus exploitation tradeoff" but also obviates the need for expensive computation for exploration. The algorithm differs from classical adaptive control in its focus on non-asymptotic regret optimality as opposed to asymptotic stability. This seems to resolve a long standing open problem in Reinforcement Learning.

Date and Time:
Tuesday, April 24, 2018 - 4:00pm
Venue:
Packard 101

## IT-Forum: Arbitrarily Varying Broadcast and Relay Channels

Topic:
Arbitrarily Varying Broadcast and Relay Channels
Abstract / Description:

Two models of an arbitrarily varying channel (AVC) are studied; both are relevant to modern networks under jamming attacks by an adversary or a hacker. The arbitrarily varying broadcast channel is considered when state information is available at the transmitter in a causal manner. Inner and outer bounds are established, on both the random code capacity region and the deterministic code capacity region with degraded message sets. The form of the bounds raises the question whether the minimax theorem can be generalized to rate regions, i.e. whether the order of the intersection over state distributions and the union over Shannon strategies can be interchanged. A sufficient condition is given, under which this assertion holds and the random code capacity region is determined. As an example, the arbitrarily varying binary symmetric broadcast channel is examined, showing that there are cases where the condition holds, hence the capacity region is determined, and other cases where there is a gap between the bounds. The gap implies that the minimax theorem does not always hold for rate regions.

In the second part of the talk, a new model is introduced, namely, the arbitrarily varying relay channel. The results include the cutset bound, decode-forward bound and partial decode-forward bound on the random code capacity, which require modification of the usual methods for the AVC to fit the block Markov coding scheme. The random code capacity is further determined for special cases. Then, deterministic coding schemes are considered, and the deterministic code capacity is derived under certain conditions, for the degraded and reversely degraded relay channel, and the case of orthogonal sender components. The following question is addressed: If the encoder-decoder and encoder-relay marginals are both symmetrizable, does that necessarily imply zero capacity? We show and explain why the answer is no. The random code capacity is determined for the arbitrarily varying Gaussian relay channel with sender frequency division, and the deterministic code capacity is bounded using the techniques of Csisz\'ar and Narayan's 1991 paper on the Gaussian AVC. It is observed that the gap vanishes as the input becomes less constrained. It is commonly believed that the primitive relay channel "captures most essential features and challenges of relaying, and thus serves as a good testbed for new relay coding techniques" (Kim, 2007). It is observed that in the arbitrarily varying case, this may no longer be true.

This work is part of a Ph.D. thesis under the supervision of Yossef Steinberg.

Date and Time:
Friday, October 12, 2018 - 1:15pm
Venue:
Packard 202

## IT-Forum: Structured Cooperation for Channels with Feedback and beyond

Topic:
Structured Cooperation for Channels with Feedback and beyond
Abstract / Description:

The capacities of fundamental communication problems such as channels with feedback and two-way communications channels are characterized with multi-letter expressions. The challenge in simplifying these expressions is their exhaustive dependence on all information that is accumulated throughout the communication. In this talk, we aim to simplify such capacities by imposing a structure on the accumulated data via a new sequential quantization technique on a directed graph.

First application of this method is for channels with memory and feedback. We will show upper and lower single-letter bounds on the capacity. The bounds are expressed with structured auxiliary random variable (r.v.), a notion that suits problems of sequential nature. For all cases where the capacity is known, the bounds are tight (with small cardinality of the structured auxiliary r.v.). This reveals a simple capacity formula that captures the major role of structure in feedback problems. We will also present a simple and sequential coding scheme, which is based on the posterior matching principle, and achieves the lower bound (and the capacity in many cases).

As time permits, we will show that structure is beneficial for other communication scenarios such as two-way communication channels with common outputs and the energy harvesting model.

The talk is based on a joint work with Prof. Henry Pfister (Duke Univeristy), Prof. Haim Permuter (BGU) and Prof. Navin Kashyap (IISc).

Date and Time:
Monday, October 8, 2018 - 4:15pm
Venue:
Packard 202

## IT-Forum: Data-Driven Policy Learning: Generalization and Optimization

Topic:
Data-Driven Policy Learning: Generalization and Optimization
Abstract / Description:

The problem of learning good treatment assignment rules from observational data lies at the heart of many challenges in data-driven decision making. While there is a growing body of literature devoted to this problem, most existing results are focused on the binary-action case (i.e., where one action corresponds to assignment to control and to assignment to treatment). In this paper, we study the offline multi-action policy learning problem with observational data and, building on the theory of efficient semi-parametric inference, propose and implement a policy learning algorithm that achieves asymptotically minimax-optimal regret. To the best of our knowledge, this is the first result of this type in the multi-action setup and provides a substantial performance improvement over the existing learning algorithms. We additionally investigate the application aspects of policy learning by working with decision trees, and discuss two different approaches for solving the key step of the learning algorithm to exact optimality, one using a mixed integer program formulation and the other using a tree-search based algorithm.

This is joint work with Susan Athey and Stefan Wager.

The Information Theory Forum (IT-Forum) at Stanford ISL is an interdisciplinary academic forum which focuses on mathematical aspects of information processing. With a primary emphasis on information theory, we also welcome researchers from signal processing, learning and statistical inference, control and optimization to deliver talks at our forum. We also warmly welcome industrial affiliates in the above fields. The forum is typically held in Packard 202 every Friday at 1:15 pm during the academic year.

The Information Theory Forum is organized by graduate students Yanjun Han and Yihui Quek. To suggest speakers, please contact any of the students.

Date and Time:
Friday, October 5, 2018 - 1:15pm
Venue:
Packard 202

## IT-Forum presents Representations, fairness, and privacy: information-theoretic tools for machine learning

Topic:
Representations, fairness, and privacy: information-theoretic tools for machine learning
Abstract / Description:

Information theory can shed light on the algorithm-independent limits of learning from data and serve as a design driver for new machine learning algorithms. In this talk, we discuss a set of flexible information-theoretic tools called the principal inertia components (PICs) that can be used to (i) understand fairness and discrimination in machine learning models, (ii) provide an estimation-theoretic view of privacy, and (iii) characterize data representations learned by complex learning models. The PICs enjoy a long history in both the statistics and information theory, and provide a fine-grained decomposition of the dependence between two random variables. We illustrate these techniques in both synthetic and real-world datasets, and discuss future research directions.

Date and Time:
Friday, September 28, 2018 - 1:15pm
Venue:
Packard 202

## IT-Forum: Reverse hypercontractivity beats measure concentration for information theoretic converses

Topic:
Reverse hypercontractivity beats measure concentration for information theoretic converses
Abstract / Description:

Concentration of measure is a collection of tools and results from analysis and probability theory that have been used in many areas of pure and applied mathematics. Arguably, the first data science application of measure concentration (under the name ''blowing-up lemma'') is the proof of strong converses in multiuser information theory by Ahlswede, G\'acs and K\"orner in 1976. Since then, measure concentration has found applications in many other information theoretic problems, most notably the converse (impossibility) results in information theory. Motivated by this, information theorists (e.g. Marton) have also contributed to the mathematical foundations of measure concentration using their information-theoretic techniques.

Now, after all the past 40 years of such progress, we found that, amusingly, measure concentration is not the right hammer for many of these information theoretic applications. We introduce a new machinery based on functional inequalities and reverse hypercontractivity which yields strict improvements in terms of sharpness of the bounds, generality of the source/channel distributions, and simplicity of the proofs. Examples covered in the talk include: 1. optimal second-order converse to common randomness generation with rate-limited communication; 2. sharpening the relay channel converse bounds by and Wu and Ozgur with much simpler proofs.

The work benefited from collaborations with Thomas Courtade, Paul Cuff, Ayfer Ozgur, Ramon van Handel, and Sergio Verd\'u.

Date and Time:
Friday, August 24, 2018 - 1:15pm
Venue:
Packard 202

Topic:
Abstract / Description:

Quantization plays a critical role in digital signal processing systems. Quantizers are typically designed to obtain an accurate digital representation of the input signal, operating independently of the system task, and are commonly implemented using serial scalar analog-to-digital converters (ADCs). This talk is concerned with hardware-limited task-based quantization, where a system utilizing a serial scalar ADC is designed to provide a suitable representation in order to allow the recovery of a parameter vector underlying the input signal. We propose hardware-limited task-based quantization systems for a fixed and finite quantization resolution, and characterize their achievable distortion. Our results illustrate the benefits of properly taking into account the underlying task in the design of the quantization scheme.

Date and Time:
Wednesday, June 13, 2018 - 1:15pm
Venue:
Packard 202

## IT Forum: Phase transitions in generalized linear models

Topic:
Phase transitions in generalized linear models
Abstract / Description:

This is joint work with Jean Barbier, Florent Krzakala, Nicolas Macris and Lenka Zdeborova.

We consider generalized linear models (GLMs) where an unknown $n$-dimensional signal vector is observed through the application of a random matrix and a non-linear (possibly probabilistic) componentwise output function.

We study the models in the high-dimensional limit, where the observations consists of $m$ points, and $m/n \to \alpha > 0$ as $n \to \infty$. This situation is ubiquitous in applications ranging from supervised machine learning to signal processing.

We will analyze the model-case when the observation matrix has i.i.d. elements and the components of the ground-truth signal are taken independently from some known distribution.

We will compute the limit of the mutual information between the signal and the observations in the large system limit. This quantity is particularly interesting because it is related to the free energy (i.e. the logarithm of the partition function) of the posterior distribution of the signal given the observations. Therefore, the study of the asymptotic mutual information allows to deduce the limit of important quantities such as the minimum mean squared error for the estimation of the signal.

We will observe some phase transition phenomena. Depending on the noise level, the distribution of the signal and the non-linear function of the GLM we may encounter various scenarios where it may be impossible / hard (only with exponential-time algorithms) / easy (with polynomial-time algorithms) to recover the signal.

Date and Time:
Friday, May 18, 2018 - 1:15pm
Venue:
Packard 202

## ISL Colloquium & IT Forum: Random initialization and implicit regularization in nonconvex statistical estimation

Topic:
Random initialization and implicit regularization in nonconvex statistical estimation
Abstract / Description:

Recent years have seen a flurry of activities in designing provably efficient nonconvex procedures for solving statistical estimation / learning problems. Due to the highly nonconvex nature of the empirical loss, state-of-the-art procedures often require suitable initialization and proper regularization (e.g. trimming, regularized cost, projection) in order to guarantee fast convergence. For vanilla procedures such as gradient descent, however, prior theory is often either far from optimal or completely lacks theoretical guarantees.

This talk is concerned with a striking phenomenon arising in two nonconvex problems (i.e. phase retrieval and matrix completion): even in the absence of careful initialization, proper saddle escaping, and/or explicit regularization, gradient descent converges to the optimal solution within a logarithmic number of iterations, thus achieving near-optimal statistical and computational guarantees at once. All of this is achieved by exploiting the statistical models in analyzing optimization algorithms, via a leave-one-out approach that enables the decoupling of certain statistical dependency between the gradient descent iterates and the data. As a byproduct, for noisy matrix completion, we demonstrate that gradient descent achieves near-optimal entrywise error control.

Date and Time:
Wednesday, May 23, 2018 - 4:15pm
Venue:
Building 370

## IT-Forum: Tight sample complexity bounds via dualizing LeCam's method

Topic:
Tight sample complexity bounds via dualizing LeCam's method
Abstract / Description:

In this talk we consider a general question of estimating linear functional of the distribution based on the noisy samples from it. We discover that the (two-point) LeCam lower bound is in fact achievable by optimizing bias-variance tradeoff of an empirical-mean type of estimator. We extend the method to certain symmetric functionals of high-dimensional parametric models.

Next, we apply this general framework to two problems: population recovery and predicting the number of unseen species. In population recovery, the goal is to estimate an unknown high-dimensional distribution (in $L_\infty$-distance) from noisy samples. In the case of \textit{erasure} noise, i.e. when each coordinate is erased with probability $\epsilon$, we discover a curious phase transition in sample complexity at $\epsilon=1/2$. In the second (classical) problem, we observe $n$ iid samples from an unknown distribution on a countable alphabet and the goal is to predict the number of new species that will be observed in the next (unseen) $tn$ samples. Again, we discover a phase transition at $t=1$. In both cases, the complete characterization of sample complexity relies on complex-analytic methods, such as Hadamard's three-lines theorem.

Joint work with Yihong Wu (Yale).

Date and Time:
Friday, May 4, 2018 - 1:15pm
Venue:
Packard 202

## IT Forum: From Gaussian Multiterminal Source Coding to Distributed Karhunen–Loève Transform

Topic:
From Gaussian Multiterminal Source Coding to Distributed Karhunen–Loève Transform
Abstract / Description:

Characterizing the rate-distortion region of Gaussian multiterminal source coding is a longstanding open problem in network information theory. In this talk, I will show how to obtain new conclusive results for this problem using nonlinear analysis and convex relaxation techniques. A byproduct of this line of research is an efficient algorithm for determining the optimal distributed Karhunen–Loève transform in the high-resolution regime, which partially settles a question posed by Gastpar, Dragotti, and Vetterli. I will also introduce a generalized version of the Gaussian multiterminal source coding problem where the source-encoder connections can be arbitrary. It will be demonstrated that probabilistic graphical models offer an ideal mathematical language for describing how the performance limit of a generalized Gaussian multiterminal source coding system depends on its topology, and more generally they can serve as the long-sought platform for systematically integrating the existing achievability schemes and converse arguments. The architectural implication of our work for low-latency lossy source coding will also be discussed.

This talk is based on joint work with Jia Wang, Farrokh Etezadi, and Ashish Khisti.

The Information Theory Forum (IT-Forum) at Stanford ISL is an interdisciplinary academic forum which focuses on mathematical aspects of information processing. With a primary emphasis on information theory, we also welcome researchers from signal processing, learning and statistical inference, control and optimization to deliver talks at our forum. We also warmly welcome industrial affiliates in the above fields. The forum is typically held in Packard 202 every Friday at 1:15 pm during the academic year.

The Information Theory Forum is organized by graduate students Jiantao Jiao and Yanjun Han. To suggest speakers, please contact any of the students.

Date and Time:
Friday, April 13, 2018 - 1:15pm
Venue:
Packard 202

## AP483, Ginzton Lab, & AMO Seminar Series

Topic:
TBA
Abstract / Description:

Academic year 2018-2019, please join us at Spilker room 232 every Monday afternoon from 4 pm for the AP 483 & Ginzton Lab, and AMO Seminar Series.

Refreshments begin at 4 pm, seminar at 4:15 pm.

Date and Time:
Monday, December 3, 2018 - 4:15pm
Venue:
Spilker 232

## AP483, Ginzton Lab, & AMO Seminar Series

Topic:
TBA
Abstract / Description:

Academic year 2018-2019, please join us at Spilker room 232 every Monday afternoon from 4 pm for the AP 483 & Ginzton Lab, and AMO Seminar Series.

Refreshments begin at 4 pm, seminar at 4:15 pm.

Date and Time:
Monday, November 26, 2018 - 4:15pm
Venue:
Spilker 232

## AP483, Ginzton Lab, & AMO Seminar Series

Topic:
When quantum-information scrambling met quasiprobabilities
Abstract / Description:

Academic year 2018-2019, please join us at Spilker room 232 every Monday afternoon from 4 pm for the AP 483 & Ginzton Lab, and AMO Seminar Series.

Refreshments begin at 4 pm, seminar at 4:15 pm.

Date and Time:
Monday, November 12, 2018 - 4:15pm
Venue:
Spilker 232

## AP483, Ginzton Lab, & AMO Seminar Series

Topic:
TBA
Abstract / Description:

Academic year 2018-2019, please join us at Spilker room 232 every Monday afternoon from 4 pm for the AP 483 & Ginzton Lab, and AMO Seminar Series.

Refreshments begin at 4 pm, seminar at 4:15 pm.

Date and Time:
Monday, October 29, 2018 - 4:15pm
Venue:
Spilker 232

## AP483, Ginzton Lab, & AMO Seminar Series

Topic:
New opportunities with old photonic materials
Abstract / Description:

Lithium niobate (LN) is an "old" material with many applications in optical and microwave technologies, owing to its unique properties that include large second order nonlinear susceptibility, large piezoelectric response, and wide optical transparency window. Conventional LN components, including modulators and periodically polled frequency converters, have been the workhorse of the optoelectronic industry. They are reaching their limits, however, as they rely on weakly guiding ion-diffusion defined optical waveguides in bulk LN crystal. I will discuss our efforts aimed at the development of integrated LN platform, featuring sub-wavelength scale light confinement and dense integration of optical and electrical components, that has the potential to revolutionize optical communication networks and microwave photonic systems, as well as enable realization of quantum photonic circuits. Good example is our recently demonstrated integrated LN electro-optic modulator that can be driven directly by a CMOS circuit, that supports data rates > 200 gigabits per second with > 90% optical transmission efficiency. I will also discuss our work on ultra-high Q LN optical cavities (Q ~ 10,000,000) and their applications, as well as nonlinear wavelength conversion using different approaches based on LN films.
Diamond is another "old" material with remarkable properties! It is transparent from the ultra-violet to infrared, has a high refractive index, strong optical nonlinearity and a wide variety of light-emitting defects of interest for quantum communication and computation. In my talk, I will summarize our efforts towards the development of integrated diamond quantum photonics platform aimed at realization of efficient photonic and phononic interfaces for diamond spin qubits.

Academic year 2018-2019, please join us at Spilker room 232 every Monday afternoon from 4 pm for the AP 483 & Ginzton Lab, and AMO Seminar Series.

Refreshments begin at 4 pm, seminar at 4:15 pm.

Date and Time:
Monday, October 22, 2018 - 4:15pm
Venue:
Spilker 232

## AP483, Ginzton Lab, & AMO Seminar Series presents Dynamic photonic structures

Topic:
Dynamic photonic structures: non-reciprocity, gauge potential, and synthetic dimensions.
Abstract / Description:

We show that dynamic photonic structures, where refractive index of the structure is modulated as a function of time, offers a wide ranges of possibilities for exploration of physics and applications of light. In particular, dynamic photonic structures naturally break reciprocity. With proper design such photonic structure can then be used to achieve complete optical isolation and to completely reproduce magneto-optical effects without the use of gyrotropic materials. Moreover, the phase of the modulation corresponds to an effective magnetic gauge potential for photons, through which one can explore a wide variety of fundamental physics effects of synthetic magnetic field using photons. Finally, such dynamic photonic structure can be used to explore physics, especially topological physics, in dimensions that are higher than the physical dimension of the structure, leading to intriguing possibilities in manipulation of the frequencies of light in non-trivial ways.

Academic year 2018-2019, please join us at Spilker room 232 every Monday afternoon from 4 pm for the AP 483 & Ginzton Lab, and AMO Seminar Series.

Refreshments begin at 4 pm, seminar at 4:15 pm.

Date and Time:
Monday, October 15, 2018 - 4:15pm
Venue:
Spilker 232

## OSA/SPIE Seminar: New Forms of Microscopy Enabled by Nanostructured Surfaces

Topic:
New Forms of Microscopy Enabled by Nanostructured Surfaces
Abstract / Description:

Since the advent of optical microscopy, a flat glass microscope slide has been the standard surface upon which tissues, cells, and biomolecules are attached for observation. Recently, we have utilized the optically resonant properties of nanostructured photonic crystal (PC) surfaces to enable several new microscopy modalities where the nanostructure provides new forms of contrast for a wide variety of compelling applications. By designing PC surfaces with resonances that match the excitation and emission spectra of photon emitters such as fluorophores and quantum dots, PC enhanced fluorescence (PCEF) microscopy reduces the detection limits of any surface-based fluorescence assay. By generating spatial images of the PC resonant reflection intensity, we can selectively and dynamically visualize the cell-extracellular matrix interface during processes that include stem cell differentiation, cancer cell response to drugs, and chemotaxis – including the ability to observe the formation and evolution of cell membrane focal adhesion sites. We call this approach Photonic Resonator Outcoupler Microscopy (PROM), as we observe highly localized outcoupling of light from the PC that occurs due to scattering by dense regions in the cell membrane. By utilizing metallic nanoparticle tags with plasmon resonances that match the PC resonance, we obtain highly efficient coupling of light into nanometer-scale electromagnetic hotspots, that is accompanied by highly localized "quenching" of the PC reflection efficiency, which we are using for digital-resolution detection of miRNA biomarkers for cancer with 100 aM limits of detection, using an approach called Photonic Resonator Absorption Microscopy (PRAM). The seminar will describe the physical principles, nanostructure design/fabrication, instrumentation, and applications for nanostructure-enabled microscopy for disease diagnostics, personalized medicine, and life science research.

Date and Time:
Thursday, October 18, 2018 - 4:15pm
Venue:
Spilker 232

## OSA/SPIE Seminar: Tunable and nonlinear metasurfaces: fundamentals and applications

Topic:
Tunable and nonlinear metasurfaces: fundamentals and applications
Abstract / Description:

Metasurfaces are artificial quasi-planar structures that can tailor light fields on demand. Their optical properties, however, are fixed upon fabrication, and a challenge is to find how to tune them externally. In the first part of the talk, I will review different approaches to tune optical properties of metasurfaces, including thermo-optic, electro-optic and all-optical ones, with applications in high-speed polarimetric devices and controllable ultrathin lens. In the second part, we will explore resonant semiconductor nanoparticles and metasurfaces as nonlinear frequency converters that have a potential to serve as ultrafast, nanoscale all-optical logic elements.

Date and Time:
Tuesday, August 28, 2018 - 4:15pm
Venue:
Spilker 232

## OSA/SPIE Seminar: Glassification of the telecom/datacom world

Topic:
Glassification of the telecom/datacom world
Abstract / Description:

Emerging trends in applications of communication and data management are driving exciting challenges in the telecom/datacom industry. From 5G driving optical-wireless convergence all the way to hyperscale datacenters bringing the optical signal closer to the switch ASIC, breakthroughs in the technology enabling optical connectivity are becoming critical for the future. In this discussion, we will provide a quick overview of recent evolution and some emerging challenges in advanced optical connectivity, as well as insight on how Corning is embracing the opportunity to solve those challenges with glass.

Date and Time:
Wednesday, August 8, 2018 - 12:30pm
Venue:
Shriram 108

## OSA/SPIE Seminar: Computational Optics for Multidimensional Nanoscale Imaging of Single Fluorescent Molecules

Topic:
Computational Optics for Multidimensional Nanoscale Imaging of Single Fluorescent Molecules
Abstract / Description:

Visualizing the dynamic movements and interactions between biomolecules remains a challenge, motivating the development of new optical technology and computational algorithms for imaging at the nanoscale. We have built two technologies for multidimensional imaging of single molecules (SMs): the Tri-spot point spread function (PSF) and the Robust Statistical Estimation (RoSE) algorithm. The Tri-spot PSF measures each second moment of SM orientation with near-uniform sensitivity, thereby capturing the orientation and rotational diffusion of SMs using just one camera frame. For 3D imaging, we developed RoSE to minimize the vectorial localization errors in super-resolution microscopy that result from both the structure of the sample and the PSF itself. By estimating the likelihood of a blinking event to be present in each imaging frame, RoSE localizes molecules accurately and minimizes false localizations even when images overlap.

Date and Time:
Thursday, June 7, 2018 - 4:15pm
Venue:
Spilker 232

## SCIEN Talk: Plenoptic Medical Cameras

Topic:
Plenoptic Medical Cameras
Abstract / Description:

Optical imaging probes like otoscopes and laryngoscopes are essential tools used by doctors to see deep into the human body. Until now, they have been crucially limited to two-dimensional (2D) views of tissue lesions in vivo that frequently jeopardize their diagnostic usefulness. Depth imaging is critically needed in medical diagnostics because most tissue lesions manifest themselves as abnormal 3D structural changes. In this talk, I will talk our recent effort to develop three-dimensional (3D) plenoptic imaging tool that revolutionizes diagnosis with unprecedented sensitivity and specificity in the images produced. Particularly, I will discuss two plenoptic medical cameras, a plenoptic otoscope and a plenoptic laryngoscope, and their applications for in-vivo imaging.

Date and Time:
Wednesday, December 5, 2018 - 4:30pm
Venue:
Packard 101

## SCIEN Talk: Perceptual Modeling with Multimodal Sensing

Topic:
Perceptual Modeling with Multimodal Sensing
Abstract / Description:

The research of human perception has enabled many visual applications in computer graphics that efficiently utilize computation resources to deliver a high quality experience within the limitations of the hardware. Beyond vision, humans perceive their surrounding using variety of senses to build a mental model of the world and act upon it. This mental image is often incomplete or incorrect which may have safety implications. As we cannot directly see inside the head, we need to read indirect signals projected outside. In the first part of the talk I will show how perceptual modeling can be used to overcome and exploit limitations of one specific human sense - the vision. Then, I will describe how we can build sensors to observe other human interactions connected first with physical touch and then with eye gaze patterns. Finally, I will outline how such readings can be used to teach computers to understand human behavior, to predict and to provide assistance or safety.

Date and Time:
Wednesday, November 28, 2018 - 4:30pm
Venue:
Packard 101

## SCIEN Talk: Photo Forensics from JPEG Coding Artifacts

Topic:
Photo Forensics from JPEG Coding Artifacts
Abstract / Description:

The past few years have seen a startling and troubling rise in the fake-news phenomena in which everyone from individuals to state-sponsored entities produce and distribute mis-information, which is then widely promoted and disseminated on social media. The implications of fake news range from a mis-informed public to an existential threat to democracy, and horrific violence. At the same time, recent and rapid advances in machine learning are making it easier than ever to create sophisticated and compelling fake images and videos, making the fake-news phenomena even more powerful and dangerous. I will start by providing a broad overview of the field of image and video forensics and then I will describe in detail a suite of image forensic techniques that explicitly detect inconsistencies in JPEG coding artifacts.

Date and Time:
Wednesday, November 14, 2018 - 4:30pm
Venue:
Packard 101

## SCIEN Talk: Image Domain Transfer

Topic:
Image Domain Transfer
Abstract / Description:

TBA

Date and Time:
Wednesday, November 7, 2018 - 4:30pm
Venue:
Packard 101

## SCIEN Talk: Wavefront coding techniques and resolution limits for light field microscopy

Topic:
Wavefront coding techniques and resolution limits for light field microscopy
Abstract / Description:

Light field microscopy is a rapid, scan-less volume imaging technique that requires only a standard wide field fluorescence microscope and a microlens array. Unlike scanning microscopes, which collect volumetric information over time, the light field microscope captures volumes synchronously in a single photographic exposure, and at speeds limited only by the frame rate of the image sensor. This is made possible by the microlens array, which focuses light onto the camera sensor so that each position in the volume is mapped onto the sensor as a unique light intensity pattern. These intensity patterns are the position-dependent point response functions of the light field microscope. With prior knowledge of these point response functions, it is possible to "decode" 3-D information from a raw light field image and computationally reconstruct a full volume. In this talk I present an optical model for light field microscopy based on wave optics that accurately models light field point response functions. I describe an algorithm that solves for volumes using a GPU-accelerated iterative algorithm, and discuss priors that are useful for reconstructing biological specimens. I then explore the diffraction limit that applies for light field microscopy, and how it gives rise to a position-dependent resolution limits for this microscope. I'll explain how these limits differ from more familiar resolution metrics commonly used in 3-D scanning microscopy, like the Rayleigh limit and the optical transfer function (OTF). Using this theory of resolution limits for the light field microscope, I explore new wavefront coding techniques that can modify the light field resolution limits and can address certain common reconstruction artifacts, at least to a degree. Certain resolution trade-offs exist that suggest that light field microscopy is just one of potentially many useful forms of computational microscopy. Finally, I describe our application of light field microscopy in neuroscience where we have used it to record calcium activity in populations of neurons within the brains of awake, behaving animals.

Date and Time:
Wednesday, October 31, 2018 - 4:30pm
Venue:
Packard 101

## SCIEN Talk: Is it real? Deep Neural Face Reconstruction and Rendering

Topic:
Is it real? Deep Neural Face Reconstruction and Rendering
Abstract / Description:

A broad range of applications in visual eﬀects, computer animation, autonomous driving, and man-machine interaction heavily depend on robust and fast algorithms to obtain high-quality reconstructions of our physical world in terms of geometry, motion, reflectance, and illumination. Especially, with the increasing popularity of virtual, augmented and mixed reality devices, there comes a rising demand for real-time and low-latency solutions.

This talk covers data-parallel optimization and state-of-the-art machine learning techniques to tackle the underlying 3D and 4D reconstruction problems based on novel mathematical models and fast algorithms. The particular focus of this talk is on self-supervised face reconstruction from a collection of unlabeled in-the-wild images. The proposed approach can be trained end-to-end without dense annotations by fusing a convolutional encoder with a differentiable expert-designed renderer and a self-supervised training loss.

The resulting reconstructions are the foundation for advanced video editing effects, such as photo-realistic re-animation of portrait videos. The core of the proposed approach is a generative rendering-to-video translation network that takes computer graphics renderings as input and generates photo-realistic modified target videos that mimic the source content. With the ability to freely control the underlying parametric face model, we are able to demonstrate a large variety of video rewrite applications. For instance, we can reenact the full head using interactive user-controlled editing and realize high-fidelity visual dubbing.

Date and Time:
Wednesday, October 24, 2018 - 4:30pm
Venue:
Packard 101

## SCIEN Talk: Computational microscopy of dynamic order across biological scales

Topic:
Computational microscopy of dynamic order across biological scales
Abstract / Description:

Living systems are characterized by emergent behavior of ordered components. Imaging technologies that reveal dynamic arrangement of organelles in a cell and of cells in a tissue are needed to understand the emergent behavior of living systems. I will present an overview of challenges in imaging dynamic order at the scales of cells and tissue, and discuss advances in computational label-free microscopy to overcome these challenges.

Date and Time:
Wednesday, October 17, 2018 - 4:30pm
Venue:
Packard 101

## SCIEN Talk: How to train neural networks on LiDAR point clouds

Topic:
How to train neural networks on LiDAR point clouds
Abstract / Description:

Accurate LiDAR classification and segmentation is required for developing critical ADAS & Autonomous Vehicles components. Mainly, its required for high definition mapping and developing perception and path/motion planning algorithms. This talk will cover best practices for how to accurately annotate and benchmark your AV/ADAS models against LiDAR point cloud ground truth training data.

Date and Time:
Wednesday, October 10, 2018 - 4:30pm
Venue:
Packard 101

## SCIEN & EE 292E: The challenge of large-scale brain imaging

Topic:
The challenge of large-scale brain imaging
Abstract / Description:

Advanced optical microscopy techniques have enabled the recording and stimulation of large populations of neurons deep within living, intact animal brains. I will present a broad overview of these techniques, and discuss challenges that still remain in performing large-scale imaging with high spatio-temporal resolution, along with various strategies that are being adopted to address these challenges.

Date and Time:
Wednesday, October 3, 2018 - 4:30pm
Venue:
Packard 101

## SCIEN Talk, eWear seminar: 'Immersive Technology and AI' with focus on mobile AR research

Topic:
'Immersive Technology and AI' with focus on mobile AR research
Abstract / Description:

Talk Title: Saliency in VR: How Do People Explore Virtual Environments,presented by Vincent Sitzmann

Understanding how people explore immersive virtual environments is crucial for many applications, such as designing virtual reality (VR) content, developing new compression algorithms, or learning computational models of saliency or visual attention. Whereas a body of recent work has focused on modeling saliency in desktop viewing conditions, VR is very different from these conditions in that viewing behavior is governed by stereoscopic vision and by the complex interaction of head orientation, gaze, and other kinematic constraints. To further our understanding of viewing behavior and saliency in VR, we capture and analyze gaze and head orientation data of 169 users exploring stereoscopic, static omni-directional panoramas, for a total of 1980 head and gaze trajectories for three different viewing conditions. We provide a thorough analysis of our data, which leads to several important insights, such as the existence of a particular fixation bias, which we then use to adapt existing saliency predictors to immersive VR conditions. In addition, we explore other applications of our data and analysis, including automatic alignment of VR video cuts, panorama thumbnails, panorama video synopsis, and saliency-based compression.

Talk Title: "Immersive Technology and AI" with focus on mobile AR research

Abstract: not available

Date and Time:
Thursday, May 31, 2018 - 3:30pm
Venue:
Spilker 232

## SmartGrid Seminar: Energy Management

Topic:
Energy Management
Abstract / Description:

TBA

The seminars are scheduled for 1:30 pm on the dates listed above. The speakers are renowned scholars or industry experts in power and energy systems. We believe they will bring novel insights and fruitful discussions to Stanford. This seminar is offered as a 1 unit seminar course, CEE 272T/EE292T. Interested students can take this seminar course for credit by completing a project based on the topics presented in this course.

Yours sincerely,
Smart Grid Seminar Organization Team,

Ram Rajagopal, Associate Professor, Civil & Environmental Engineering, and Electrical Engineering
Sila Kiliccote, Managing Director of Grid Innovations, Bits & Watts
Chin-Woo Tan, Director, Stanford Smart Grid Lab
Yuting Ji, Postdoctoral Scholar, Civil and Environmental Engineering

Date and Time:
Thursday, December 6, 2018 - 1:30pm
Venue:
Y2E2 111

## SmartGrid Seminar: Battery storage

Topic:
Battery storage
Abstract / Description:

TBA

The seminars are scheduled for 1:30 pm on the dates listed above. The speakers are renowned scholars or industry experts in power and energy systems. We believe they will bring novel insights and fruitful discussions to Stanford. This seminar is offered as a 1 unit seminar course, CEE 272T/EE292T. Interested students can take this seminar course for credit by completing a project based on the topics presented in this course.

Yours sincerely,
Smart Grid Seminar Organization Team,

Ram Rajagopal, Associate Professor, Civil & Environmental Engineering, and Electrical Engineering
Sila Kiliccote, Managing Director of Grid Innovations, Bits & Watts
Chin-Woo Tan, Director, Stanford Smart Grid Lab
Yuting Ji, Postdoctoral Scholar, Civil and Environmental Engineering

Date and Time:
Thursday, November 15, 2018 - 1:30pm
Venue:
Y2E2 111

## SmartGrid Seminar: Power electronics

Topic:
Power electronics
Abstract / Description:

TBA

The seminars are scheduled for 1:30 pm on the dates listed above. The speakers are renowned scholars or industry experts in power and energy systems. We believe they will bring novel insights and fruitful discussions to Stanford. This seminar is offered as a 1 unit seminar course, CEE 272T/EE292T. Interested students can take this seminar course for credit by completing a project based on the topics presented in this course.

Yours sincerely,
Smart Grid Seminar Organization Team,

Ram Rajagopal, Associate Professor, Civil & Environmental Engineering, and Electrical Engineering
Sila Kiliccote, Managing Director of Grid Innovations, Bits & Watts
Chin-Woo Tan, Director, Stanford Smart Grid Lab
Yuting Ji, Postdoctoral Scholar, Civil and Environmental Engineering

Date and Time:
Thursday, November 8, 2018 - 1:30pm
Venue:
Y2E2 111

## SmartGrid Seminar: Clean Energy at the Crossroads: A Look Ahead Through the Eyes of an Environmental Economist

Topic:
Clean Energy at the Crossroads: A Look Ahead Through the Eyes of an Environmental Economist
Abstract / Description:

California has the will, ambition, technology and legal requirement to decarbonize our energy sector by 2045. In the dozen years since passage of AB32, we have made great progress but we may be making some grave mistakes. In this discussion, Dr. Fine describes how distributed energy resources are presenting new opportunities in distribution resources, transmission and procurement planning, and market reforms that will determine if our clean energy future is one that is affordable for all.

Date and Time:
Thursday, October 11, 2018 - 1:30pm
Venue:
Y2E2 111

## SmartGrid Seminar: Future Power System Control Functions: An Industry Perspective

Topic:
Future Power System Control Functions: An Industry Perspective
Abstract / Description:

This talk provides an overview of Siemens Corporate Technology's recent research on new control functions for future power systems. Three different topics are discussed: (a) adaptive power oscillation damping optimization to increase the stability reserve of power systems, (b) robust power flow optimization to increase power system resilience to volatile generation, and (c) new research challenges for autonomous microgrids that provide autonomous operation and plug-and-produce capabilities.

Date and Time:
Thursday, May 31, 2018 - 1:30pm
Venue:
Y2E2 111

## SmartGrid Seminar: Trends in Electric Power Distribution System Analysis at PNNL

Topic:
Trends in Electric Power Distribution System Analysis at PNNL
Abstract / Description:

Pacific Northwest National Laboratory (PNNL) originated and continues to maintain one of the two leading open-source distribution system simulators, called GridLAB-D, which has been downloaded 80,000+ times world-wide. While it continues to improve core functionality, PNNL is placing more emphasis recently on GridLAB-D as part of a development platform, improving its interoperability and opening the software up to more customization by researchers. This talk will cover two ongoing open-source development projects, funded by the U. S. Department of Energy, that incorporate and extend GridLAB-D. One of these projects is also expected to contribute distribution feeder model conversion tools for a new California Energy Commission project headed by SLAC. Highlights of the talk will include:

• Transactive energy simulation platform, at tesp.readthedocs.io/en/latest
• GridAPPS-D application development platform, at gridappsd.readthedocs.io/en/latest
• Evole GridLAB-D's co-simulation support from FNCS interface, to a multi-lab interface called HELICS compliant with Functional Mockup Interface (FMI): https://github.com/GMLC-TDC/HELICS-src
• Leveraging new capabilities for large-building simulation in JModelica, power flow analysis in OpenDSS, and transactive energy system agents in Python
• Implementation and use of the Common Information Model (CIM) in a NoSQL triple-store database for standardized feeder model conversion
• Comparison of different types of stochastic modeling for load and distributed energy resource (DER) output variability, and its impact on feeder model order reduction and state estimation
• Special system protection example concerns on urban secondary networks with high penetration of DER
Date and Time:
Thursday, May 24, 2018 - 1:30pm
Venue:
Y2E2 111

## SmartGrid Seminar: Renewable Scenario Generation Using Adversarial Networks

Topic:
Renewable Scenario Generation Using Adversarial Networks
Abstract / Description:

Scenario generation is an important step in the operation and planning of power systems. In this talk, we present a data-driven approach for scenario generation using the popular generative adversarial networks, where to deep neural networks are used in tandem. Compared with existing methods that are often hard to scale or sample from, our method is easy to train, robust, and captures both spatial and temporal patterns in renewable generation. In addition, we show that different conditional information can be embedded in the framework. Because of the feedforward nature of the neural networks, scenarios can be generated extremely efficiently.

Date and Time:
Thursday, April 19, 2018 - 1:30pm
Venue:
Y2E2 111

## SmartGrid Seminar: Increasing Power Grid Resiliency for Adverse Conditions & the Role of Renewable Energy Resources and Microgrids

Topic:
Increasing Power Grid Resiliency for Adverse Conditions & the Role of Renewable Energy Resources and Microgrids
Abstract / Description:

System resiliency is the number 1 concern for electrical utilities in 2018 according to the CEO of the PJM, the nation's largest independent system operator. This talk will offer insights and practical answers through examples, of how power grids can be affected by weather and how countermeasures, such microgrids, can be applied to mitigate them. It will focus on two major events; Super Storm Sandy and Hurricane Maria, and the role of renewable energy resources and microgrids in these two natural disasters. It will discuss the role of microgrids in blackstarting the power grid after a blackout.

Date and Time:
Thursday, April 12, 2018 - 1:30pm
Venue:
Y2E2 111

## SmartGrid Seminar: Transmission-Distribution Coordinated Energy Management: A Solution to the Challenge of Distributed Energy Resource Integration

Topic:
Transmission-Distribution Coordinated Energy Management: A Solution to the Challenge of Distributed Energy Resource Integration
Abstract / Description:

Transmission-distribution coordinated energy management (TDCEM) is recognized as a promising solution to the challenge of high DER penetration, but lack of a distributed computation method that universally and effectively works for TDCEM. To bridge this gap, a generalized master-slave-splitting (G-MSS) method is proposed based on a general-purpose transmission-distribution coordination model (G-TDCM), enabling G-MSS to be applicable to most central functions of TDCEM. In G-MSS, a basic heterogeneous decomposition (HGD) algorithm is first derived from the heterogeneous decomposition of the coupling constraints in the KKT system regarding G-TDCM. Optimality and convergence properties of this algorithm are proved. Furthermore, a modified HGD algorithm is developed by utilizing subsystem's response function, resulting in faster convergence. The distributed G-MSS method is then demonstrated to successfully solve central functions of TDCEM including power flow, contingency analysis, voltage stability assessment, economic dispatch and optimal power flow. Severe issues of over-voltage and erroneous assessment of the system security that are caused by DERs are thus resolved by G-MSS with modest computation cost. A real-world demonstration project in China will be presented.

Date and Time:
Thursday, April 5, 2018 - 1:30pm
Venue:
Y2E2 111

## SmartGrid Seminar: Johanna Mathieu

Topic:
TBA
Abstract / Description:

The speakers are renowned scholars or industry experts in power and energy systems. We believe they will bring novel insights and fruitful discussions to Stanford. This seminar is offered as a 1 unit seminar course, CEE 272T/EE292T. Interested students can take this seminar course for credit by completing a project based on the topics presented in this course.

Date and Time:
Thursday, March 1, 2018 - 1:30pm
Venue:
Y2E2 111

## Claude E. Shannon's 100th Birthday

Topic:
Centennial year of the 'Father of the Information Age'
Abstract / Description:

From UCLA Shannon Centennial Celebration website:

Claude Shannon was an American mathematician, electrical engineer, and cryptographer known as "the father of information theory". Shannon founded information theory and is perhaps equally well known for founding both digital computer and digital circuit design theory. Shannon also laid the foundations of cryptography and did basic work on code breaking and secure telecommunications.

Events taking place around the world are listed at IEEE Information Theory Society.

Date and Time:
Saturday, April 30, 2016 - 12:00pm
Venue:
N/A

## NetSeminar

Topic:
BlindBox: Deep Packet Inspection over Encrypted Traffic
Abstract / Description:

SIGCOMM 2015, Joint work with: Justine Sherry, Chang Lan, and Sylvia Ratnasamy

Many network middleboxes perform deep packet inspection (DPI), a set of useful tasks which examine packet payloads. These tasks include intrusion detection (IDS), exfiltration detection, and parental filtering. However, a long-standing issue is that once packets are sent over HTTPS, middleboxes can no longer accomplish their tasks because the payloads are encrypted. Hence, one is faced with the choice of only one of two desirable properties: the functionality of middleboxes and the privacy of encryption.

We propose BlindBox, the first system that simultaneously provides both of these properties. The approach of BlindBox is to perform the deep-packet inspection directly on the encrypted traffic. BlindBox realizes this approach through a new protocol and new encryption schemes. We demonstrate that BlindBox enables applications such as IDS, exfiltration detection and parental filtering, and supports real rulesets from both open-source and industrial DPI systems. We implemented BlindBox and showed that it is practical for settings with long-lived HTTPS connections. Moreover, its core encryption scheme is 3-6 orders of magnitude faster than existing relevant cryptographic schemes.

Date and Time:
Wednesday, November 11, 2015 - 12:15pm to 1:30pm
Venue:
Packard 202

## NetSeminar

Topic:
Precise localization and high throughput backscatter using WiFi signals
Abstract / Description:

Indoor localization holds great promise to enable applications like location-based advertising, indoor navigation, inventory monitoring and management. SpotFi is an accurate indoor localization system that can be deployed on commodity WiFi infrastructure. SpotFi only uses information that is already exposed by WiFi chips and does not require any hardware or firmware changes, yet achieves the same accuracy as state-of-the-art localization systems.

We then talk about BackFi, a novel communication system that enables high throughput, long range communication between very low power backscatter IoT sensors and WiFi APs using ambient WiFi transmissions as the excitation signal. We show via prototypes and experiments that it is possible to achieve communication rates of up to 5 Mbps at a range of 1 m and 1 Mbps at a range of 5 meters. Such performance is an order to three orders of magnitude better than the best known prior WiFi backscatter system.

Date and Time:
Thursday, October 15, 2015 - 12:15pm to 1:30pm
Venue:
Gates 104

## NetSeminar

Topic:
TBA
Abstract / Description:

TBA

Date and Time:
Thursday, December 3, 2015 - 12:15pm to 1:30pm
Venue:
Gates 104

## NetSeminar

Topic:
BlindBox: Deep Packet Inspection over Encrypted Traffic
Abstract / Description:

SIGCOMM 2015, Joint work with: Justine Sherry, Chang Lan, and Sylvia Ratnasamy

Many network middleboxes perform deep packet inspection (DPI), a set of useful tasks which examine packet payloads. These tasks include intrusion detection (IDS), exfiltration detection, and parental filtering. However, a long-standing issue is that once packets are sent over HTTPS, middleboxes can no longer accomplish their tasks because the payloads are encrypted. Hence, one is faced with the choice of only one of two desirable properties: the functionality of middleboxes and the privacy of encryption.

We propose BlindBox, the first system that simultaneously provides both of these properties. The approach of BlindBox is to perform the deep-packet inspection directly on the encrypted traffic. BlindBox realizes this approach through a new protocol and new encryption schemes. We demonstrate that BlindBox enables applications such as IDS, exfiltration detection and parental filtering, and supports real rulesets from both open-source and industrial DPI systems. We implemented BlindBox and showed that it is practical for settings with long-lived HTTPS connections. Moreover, its core encryption scheme is 3-6 orders of magnitude faster than existing relevant cryptographic schemes.

Date and Time:
Wednesday, October 7, 2015 - 12:15pm to 1:30pm
Venue:
AllenX Auditorium

## Statistics Seminar: Inference, Computation, and Visualization for Convex Clustering and Biclustering

Topic:
Inference, Computation, and Visualization for Convex Clustering and Biclustering
Abstract / Description:

Hierarchical clustering enjoys wide popularity because of its fast computation, ease of interpretation, and appealing visualizations via the dendogram and cluster heatmap. Recently, several have proposed and studied convex clustering and biclustering which, similar in spirit to hierarchical clustering, achieve cluster merges via convex fusion penalties. While these techniques enjoy superior statistical performance, they suffer from slower computation and are not generally conducive to representation as a dendogram. In the first part of the talk, we present new convex (bi)clustering methods and fast algorithms that inherit all of the advantages of hierarchical clustering. Specifically, we develop a new fast approximation and variation of the convex (bi)clustering solution path that can be represented as a dendogram or cluster heatmap. Also, as one tuning parameter indexes the sequence of convex (bi)clustering solutions, we can use these to develop interactive and dynamic visualization strategies that allow one to watch data form groups as the tuning parameter varies. In the second part of this talk, we consider how to conduct inference for convex clustering solutions that addresses questions like: Are there clusters in my data set? Or, should two clusters be merged into one? To achieve this, we develop a new geometric representation of Hotelling's T2-test that allows us to use the selective inference paradigm to test multivariate hypotheses for the first time. We can use this approach to test hypotheses and calculate confidence ellipsoids on the cluster means resulting from convex clustering. We apply these techniques to examples from text mining and cancer genomics.

This is joint work with John Nagorski and Frederick Campbell.

The Statistics Seminars for Winter Quarter will be held in Room 380Y of the Sloan Mathematics Center in the Main Quad at 4:30pm on Tuesdays.

Date and Time:
Tuesday, March 13, 2018 - 4:30pm
Venue:
Sloan Mathematics Building, Room 380Y

## Statistics Seminar presents Daniela Witten

Topic:
TBA
Abstract / Description:

TBA

The Statistics Seminars for Winter Quarter will be held in Room 380Y of the Sloan Mathematics Center in the Main Quad at 4:30pm on Tuesdays.

Date and Time:
Tuesday, March 6, 2018 - 4:30pm
Venue:
Sloan Mathematics Building, Room 380Y

## Statistics Seminar presents Jelena Bradic

Topic:
TBA
Abstract / Description:

TBA

The Statistics Seminars for Winter Quarter will be held in Room 380Y of the Sloan Mathematics Center in the Main Quad at 4:30pm on Tuesdays.

Date and Time:
Tuesday, February 27, 2018 - 4:30pm
Venue:
Sloan Mathematics Building, Room 380Y

## Statistics Seminar: A pliable lasso

Topic:
A pliable lasso
Abstract / Description:

TBA

The Statistics Seminars for Winter Quarter will be held in Room 380Y of the Sloan Mathematics Center in the Main Quad at 4:30pm on Tuesdays.

Date and Time:
Tuesday, February 20, 2018 - 4:30pm
Venue:
Sloan Mathematics Building, Room 380Y

## Statistics Seminar presents Art Owen

Topic:
TBA
Abstract / Description:

TBA

The Statistics Seminars for Winter Quarter will be held in Room 380Y of the Sloan Mathematics Center in the Main Quad at 4:30pm on Tuesdays.

Date and Time:
Tuesday, February 13, 2018 - 4:30pm
Venue:
Sloan Mathematics Building, Room 380Y

## Statistics Seminar presents Yuting Wei

Topic:
TBA
Abstract / Description:

TBA

The Statistics Seminars for Winter Quarter will be held in Room 380Y of the Sloan Mathematics Center in the Main Quad at 4:30pm on Tuesdays.

Date and Time:
Tuesday, February 6, 2018 - 4:30pm
Venue:
Sloan Mathematics Building, Room 380Y

## Statistics Seminar: Understanding rare events in models of statistical mechanics

Topic:
Understanding rare events in models of statistical mechanics
Abstract / Description:

Statistical mechanics models are ubiquitous at the interface of probability theory, information theory, and inference problems in high dimensions. To develop a refined understanding of such models, one often needs to study not only typical fluctuation theory but also the realm of atypical events. In this talk, we will focus on sparse networks and polymer models on lattices. In particular we will consider the rare events that a sparse random network has an atypical number of certain local structures, and that a polymer in random media has atypical weight. The random geometry associated with typical instances of these rare events is an important topic of inquiry: this geometry can involve merely local structures, or more global ones. We will discuss recent solutions to certain longstanding questions and connections to stochastic block models, exponential random graphs, eigenvalues of random matrices, and fundamental growth models.

Date and Time:
Tuesday, January 30, 2018 - 4:30pm
Venue:
Sloan Mathematics Building, Room 380Y

## New Directions in Management Science & Engineering: A Brief History of the Virtual Lab

Topic:
New Directions in Management Science & Engineering: A Brief History of the Virtual Lab
Abstract / Description:

Lab experiments have long played an important role in behavioral science, in part because they allow for carefully designed tests of theory, and in part because randomized assignment facilitates identification of causal effects. At the same time, lab experiments have traditionally suffered from numerous constraints (e.g. short duration, small-scale, unrepresentative subjects, simplistic design, etc.) that limit their external validity. In this talk I describe how the web in general—and crowdsourcing sites like Amazon's Mechanical Turk in particular—allow researchers to create "virtual labs" in which they can conduct behavioral experiments of a scale, duration, and realism that far exceed what is possible in physical labs. To illustrate, I describe some recent experiments that showcase the advantages of virtual labs, as well as some of the limitations. I then discuss how this relatively new experimental capability may unfold in the future, along with some implications for social and behavioral science.

Date and Time:
Thursday, March 16, 2017 - 12:15pm
Venue:
Packard 101

## Statistics Seminar

Topic:
Brownian Regularity for the Airy Line Ensemble
Abstract / Description:

The Airy line ensemble is a positive-integer indexed ordered system of continuous random curves on the real line whose finite dimensional distributions are given by the multi-line Airy process. It is a natural object in the KPZ universality class: for example, its highest curve, the Airy2 process, describes after the subtraction of a parabola the limiting law of the scaled weight of a geodesic running from the origin to a variable point on an anti-diagonal line in such problems as Poissonian last passage percolation. The Airy line ensemble enjoys a simple and explicit spatial Markov property, the Brownian Gibbs property.

In this talk, I will discuss how this resampling property may be used to analyse the Airy line ensemble. Arising results include a close comparison between the ensemble's curves after affine shift and Brownian bridge. The Brownian Gibbs technique is also used to compute the value of a natural exponent describing the decay in probability for the existence of several near geodesics with common endpoints in Brownian last passage percolation, where the notion of "near" refers to a small deficit in scaled geodesic weight, with the parameter specifying this nearness tending to zero.

Date and Time:
Monday, September 26, 2016 - 4:30pm
Venue:
Sequoia Hall, room 200

## Claude E. Shannon's 100th Birthday

Topic:
Centennial year of the 'Father of the Information Age'
Abstract / Description:

From UCLA Shannon Centennial Celebration website:

Claude Shannon was an American mathematician, electrical engineer, and cryptographer known as "the father of information theory". Shannon founded information theory and is perhaps equally well known for founding both digital computer and digital circuit design theory. Shannon also laid the foundations of cryptography and did basic work on code breaking and secure telecommunications.

Events taking place around the world are listed at IEEE Information Theory Society.

Date and Time:
Saturday, April 30, 2016 - 12:00pm
Venue:
N/A

## SystemX Seminar presents How to Build a Processor for Machine Learning

Topic:
How to Build a Processor for Machine Learning
Abstract / Description:

Compute, data, and algorithms have combined to power the recent huge strides in machine intelligence. But there is still plenty of scope for improvement, and hardware is finally coming to the fore. Machine intelligence is the future of computing, so what needs to happen at a hardware level to make it faster and more energy- and cost-efficient?

This talk will outline the key considerations in how to build an efficient processor for machine intelligence both for today's state of the art networks and also to more rapidly and more flexibly support future innovations in algorithms and model structures.

Date and Time:
Tuesday, October 23, 2018 - 1:30pm
Venue:
Gates B12

## SystemX Seminar: BONUS LECTURE- Automatic Implementation of Secure SOC'

Topic:
BONUS LECTURE Automatic Implementation of Secure SOC's
Abstract / Description:

Need for incorporation of security into next generation of microelectronics, improved economics of the platform-based design and advances in high level synthesis make efficient implementation of secure, complex SoCs possible. An opportunity exists to consider new approaches, tools, methodologies and IP that enable semi-automated and automatic approaches to assembly and integration that substantially improve SoC security. One path forward may be to develop a technology where secure, configurable, extensible, application-specific platforms can be used in conjunction with synthesis technology to automatically incorporate original functionality derived from an implementation-independent executable models as either hardware or software. Program concept for addressing this challenge at DARPA will be presented.

Date and Time:
Wednesday, October 17, 2018 - 3:00pm
Venue:
Packard 202

## EE380 Computer Systems Colloquium: Efficient and Resilient Systems in the Cognitive Era

Topic:
Efficient and Resilient Systems in the Cognitive Era
Abstract / Description:

A focus on energy efficiency in the late CMOS design era, requires extra careful attention to system reliability and resilience to hardware-sourced errors. At the same time, the emergence of AI (cognitive) applications as a key growth segment is quite obvious. This talk will attempt to address the special challenges that next generation AI (or cognitive) systems pose, with a particular focus on next generation cognitive IoT architectures. We will discuss this primarily from the point of view of providing energy-efficient resilience in environments that are likely to have built-in vulnerability to errors. Such uncertainty stems not just from potentially error-prone (late CMOS) hardware designed for extreme efficiency, but also from algorithmic brittleness of the most prevalent forms of machine learning/deep learning (ML/DL) solution strategies today. In that context, we will briefly examine the promise of the Adaptive Swarm Intelligence (ASI) architectural paradigm that we have recently started investigating at IBM Research. This is a form of distributed or decentralized computing applied to the world of mobile cognitive IoT, backed by resilient support from back-end cloud (server) systems. In addition to examining the promises of inherent system architectural scalability and in-field, continuous learning that ASI offers, we will argue (albeit philosophically!) about why this could open the door to new models of self-aware systems that mimic cooperative and conscious problem solving in a human setting.

The Stanford EE Computer Systems Colloquium (EE380) meets on Wednesdays 4:30-5:45 throughout the academic year. Talks are given before a live audience in Room B03 in the basement of the Gates Computer Science Building on the Stanford Campus. The live talks (and the videos hosted at Stanford and on YouTube) are open to the public.

Stanford students may enroll in EE380 to take the Colloquium as a one unit S/NC class. Enrolled students are required to keep and electronic notebook or journal and to write a short, pithy comment about each of the ten lectures and a short free form evaluation of the class in order to receive credit. Assignments are due at the end of the quarter, on the last day of examinations.

EE380 is a video class. Live attendance is encouraged but not required. We (the organizers) feel that watching the video is not a substitute for being present in the classroom. Questions are encouraged.

Many past EE380 talks are available on YouTube, see the EE380 Playlist.

Date and Time:
Wednesday, October 3, 2018 - 4:30pm
Venue:
Gates B03

## SystemX FALL Conference: Nov 13-15, 2018

Topic:
SystemX Fall Conference
Abstract / Description:

Save the Date for the SystemX Fall Conference.

Details published as available.

Date and Time:
Tuesday, November 13, 2018 (All day) to Thursday, November 15, 2018 (All day)
Venue:
Li Ka Shing Conference Center, Stanford University
Tags:

## SystemX Seminar: On-chip quantum technologies based on rare-earth ion crystals

Topic:
On-chip quantum technologies based on rare-earth ion crystals
Abstract / Description:

Quantum technologies for computing, communication, and metrology become much more powerful if they are part of an integrated network operating at the quantum level. The first part of the this talk will introduce some of the interconnect technologies that can help to build up large quantum networks, including quantum memories and transducers. The second part of the talk will focus on demonstrations of these types of interconnects in crystals containing rare-earth ions, including on-chip technology developed at Caltech.

Date and Time:
Thursday, October 18, 2018 - 4:30pm
Venue:
Huang 018

## SystemX Seminar: Toward Ultra-Low-Power Computing in the Era of Artificial Intelligence

Topic:
Toward Ultra-Low-Power Computing in the Era of Artificial Intelligence
Abstract / Description:

Computing technology has been a backbone of our society. Its importance is hard to overemphasize. Today, we again confirm its extreme importance with recent advances in artificial intelligence and deep learning. Those emerging workloads impose an unprecedented amount of arithmetic complexity and data access beyond our existing computing systems can barely handle. Particularly, mobile and embedded computing systems will face a major challenge in achieving energy-efficient computing for truly enabling intelligent systems. In this seminar, we will outline the bottlenecks of energy-efficient computing, notably the broken Dennard scaling and the memory wall problem. We will then discuss several approaches that our group has been working on, including a massively-parallel near-threshold processor, circuits and architectures to tolerate variability, active leakage suppression, integrated DCDC converters and voltage regulators for per-core DVFS, in-memory computing hardware, hybrid analog-digital computing, and a deep learning algorithm that reduces communication to off-chip memory. We will introduce several test-chip prototypes and their measurement results.

Date and Time:
Thursday, October 11, 2018 - 4:30pm
Venue:
Huang 018

## SystemX Seminar: Quantum Computing on Near Term Hardware

Topic:
Quantum Computing on Near Term Hardware
Abstract / Description:

Within the last few years, quantum computing has moved from an academic field of study to a blossoming industry with a healthy ecosystem comprised of startups as well as research groups at large corporations. In this talk we will give a general introduction to this topic, describe a selection of the currently competing hardware platforms and demonstrate how to program a near term quantum computer.

Date and Time:
Thursday, October 4, 2018 - 4:30pm
Venue:
Huang 018

## SystemX Seminar: Wireless Electric Vehicle Charging Overview

Topic:
Wireless Electric Vehicle Charging Overview
Abstract / Description:

The talk will provide an overview of Wireless Electric Vehicle Charging (WEVC) technology and the market. It will include a discussion of the system and its high-level components, safety and emissions considerations and standards work. Current state of the art systems both in late stage and early stage development will be discussed, including dynamic wireless charging. It will also include a brief overview on Formula E, the electric racing series.

Date and Time:
Thursday, September 27, 2018 - 4:30pm
Venue:
Huang 018

## SystemX Seminar: Intracellular recording of thousands of connected neurons on a silicon chip

Topic:
Intracellular recording of thousands of connected neurons on a silicon chip
Abstract / Description:

Massively parallel, intracellular recording of a large number of neurons across a network is a great technological pursuit in neurobiology, but it has not been achieved. The intracellular recording by the patch clamp electrode boasts unparalleled sensitivity that can measure down to sub-threshold synaptic events, but it is too bulky to be implemented into a dense massive-scale array: so far only ~10 parallel patch recordings have been possible. Optical methods––e.g., voltage-sensitive dyes/proteins––have been developed in hopes of parallelizing intracellular recording, but they have not been able to perform recording from more than ~30 neurons in parallel. As an opposite example, the microelectrode array can record from many more neurons, but this extracellular technique has too low a sensitivity to tap into synaptic activities. In this talk, I would like to share our on-going effort, a silicon chip that conducts intracellular recording from thousands of connected mammalian neurons in vitro, and discuss applications in high-throughput screening, functional connectome mapping, neuromorphic engineering, and data science.

Date and Time:
Tuesday, May 15, 2018 - 2:00pm
Venue:
Allen 101X

## SystemX Seminar: Hardware Opportunities for AI/Cognitive Computing

Topic:
Hardware Opportunities for AI/Cognitive Computing
Abstract / Description:

Deep Neural Networks (DNNs) are very large artificial neural networks trained using very large datasets, typically using the supervised learning technique known as backpropagation. Currently, CPUs and GPUs are used for these computations. Over the next few years, we can expect special-purpose hardware accelerators based on conventional digital-design techniques to optimize the GPU framework for these DNN computations. Here there are opportunities to increase speed and reduce power for two distinct but related tasks: training and forward-inference. During training, the weights of a DNN are adjusted to improve network performance through repeated exposure to the labelled data-examples of a large dataset. Often this involves a distributed network of chips working together in the cloud. During forward-inference, already trained networks are used to analyze new data-examples, sometimes in a latency-constrained cloud environment and sometimes in a power-constrained environment (sensors, mobile phones, "edge-of-network" devices, etc.)

Even after the improved computational performance and efficiency that is expected from these special-purpose digital accelerators, there would still be an opportunity for even higher performance and even better energy-efficiency from neuromorphic computation based on analog memories.

In this presentation, I discuss the origin of this opportunity as well as the challenges inherent in delivering on it, with some focus on materials and devices for analog volatile and non-volatile memory. I review our group's work towards neuromorphic chips for the hardware acceleration of training and inference of Fully-Connected DNNs [1-5]. Our group uses arrays of emerging non-volatile memories (NVM), such as Phase Change Memory, to implement the synaptic weights connecting layers of neurons. I will discuss the impact of real device characteristics – such as non-linearity, variability, asymmetry, and stochasticity – on performance, and describe how these effects determine the desired specifications for the analog resistive memories needed for this application. I present some novel solutions to finesse some of these issues in the near-term, and describe some challenges in designing and implementing the CMOS circuitry around the NVM array. I will end with an outlook on the prospects for analog memory-based DNN hardware accelerators.

[1] G. W. Burr et al., IEDM Tech. Digest, 29.5 (2014).
[2] G. W. Burr et al., IEEE Trans. Elec. Dev, 62(11), pp. 3498 (2015).
[3] G. W. Burr et al., IEDM Tech. Digest, 4.4 (2015).
[4] P. Narayanan et al., IBM J. Res. Dev., 61(4/5), 11:1-11 (2017).
[5] S. Ambrogio et al., Nature, to appear (2018).

Date and Time:
Thursday, May 31, 2018 - 4:30pm
Venue:
Gates B03