VictorJuiz/thesis huggingface dataset:
Sufficient and approximately sufficient statistics for team decision problems [electronic resource]

In a decentralized control problem, multiple agents with access to different sets of information choose their actions in order to minimize a common cost. Although decentralized control problems are difficult to solve in general, several special classes of these problems have been found to be tractable. A common theme in these tractable cases is the existence of sufficient statistics, which are compressed versions of the information available to the agents that retain enough information to allow for optimal decisions. Although there is a general theory of sufficient statistics for single-agent decision problems, most of the sufficient statistics known for decentralized decision problems have been obtained through ad hoc analysis. Wu and Lall developed a theory of sufficient statistics for a simple class of decentralized decision problems called team decision problems, and proved that these statistics are sufficient for making optimal decisions, and can be updated efficiently, even when the agents affect how the world changes. This thesis presents a new theory of sufficient statistics for team decision problems. Our new definition is both necessary and sufficient for making optimal decisions in team decision problems, although statistics satisfying this definition can only be updated when the agents do not affect how the world changes. We then generalize our definition to give the first general definition of approximately sufficient statistics for team decision problems. This is an important development because decentralized decision making is such a complex problem that we may need to compress the information given to the agents beyond what is necessary for optimality in order to obtain a problem we can solve in practice. We also propose a practical algorithm for computing approximately sufficient statistics.

Keywords: Electrical Engineering.
Advisor: Lall Sanjay primary advisor. Thesis advisor
Boyd Stephen P. advisor. Thesis advisor
Ye Yinyu advisor. Thesis advisor
Supervised evaluation of representations [electronic resource]

Intuitively speaking, a good data representation (that is, a dimensionality-reducing mapping) reveals meaningful differences between inputs, while being relatively invariant to differences between inputs due to irrelevant factors or noise. In this work, we consider criteria for formally defining the quality of a representation, which all make use of the availability of a response variable Y to distinguish between meaningful and meaningless variation. Hence, these are criteria for supervised evaluation of representations. We consider three particular criteria: the mutual information between the representation and the response, the average accuracy of a randomized classification task, and the identification accuracy. We discuss methods for estimating all three quantities, and also show how these three quantities are interrelated. Besides the application of evaluating representations, our work also has relevance for estimation of mutual information in high-dimensional data, for obtaining performance guarantees for recognition systems, and for making statements about the generalizability of certain kinds of classification-based experiments which are found in neuroscience.

Keywords: Statistics.
Advisor: Hastie Trevor primary advisor. Thesis advisor
Taylor Jonathan
Efron Bradley advisor. Thesis advisor
Poldrack Russell A.
Suspended aluminum gallium nitride/gallium nitride-on-silicon microstructures for high-temperature-tolerant micro-electromechanical systems [electronic resource]

In this Ph.D. work, advances have been made in the development of AlGaN/GaN-on-Si as a material system for high-temperature-tolerant micro electromechanical systems (MEMS). Firstly, a unique micro-fabrication process for making fully-suspended MEMS devices from AlGaN/GaN-on-Si wafers has been developed. In addition, electrical and micro-structural behaviors of Ti/Al/Pt/Au Ohmic metallization for AlGaN/GaN devices at high temperatures in air has been studied for the first time in literature. It has been shown that the contact resistance of the Ti/Al/Pt/Au Ohmic metallization remained very stable (< 3% variations) at 600°C in air for 10 hours after the initial "burn-in". Moreover, the degradation phenomena and mechanisms of the two-dimensional electron gas (2DEG) in the AlGaN/GaN heterostructures at 600°C in both oxidizing and inert ambient conditions have been examined. It has been discovered that oxygen plays a critical role in suppressing the strain relaxation of the AlGaN layer. Furthermore, suspended AlGaN/GaN MEMS ultraviolet (UV) photodetectors with in-situ heating capability have been designed, micro-fabricated and tested. The in-situ heating is used to overcome the chronic problem suffered by GaN-based optical detectors -- long decay transients (hours to days) of the photocurrent after the UV illumination source has been removed. The decay times of AlGaN/GaN UV photodetectors have been reduced from ~39 hours to ~24 seconds using the suspended AlGaN/GaN device architecture. The results demonstrate that AlGaN/GaN-on-Si, when interfaced with appropriate metallization and dielectrics, is a promising material platform for manufacturing high-temperature-tolerant MEMS.

Keywords: Electrical Engineering.
Advisor: Senesky Debbie
Howe Roger Thomas
Pop Eric advisor. Thesis advisor
Sustainable development of large urban transportation infrastructure networks [electronic resource] : management optimization and incorporation of autonomous vehicles

At the nexus of environmental, social, and economic sustainability, transportation infrastructures have a large sustainability footprint. Because of the large sustainability footprint, he effect of sustainable development on transportation infrastructures can have a great impact. This dissertation focuses on management optimization frameworks for the sustainable development of transportation infrastructure and urban transportation infrastructure networks. It first introduces optimizing sustainability at the facility-level and presents a framework for probabilistic sustainability design of reinforced concrete transportation infrastructure incorporating optimization of maintenance programs. The framework adopts a life-cycle optimization model (LCO) automating the repair and limit state selection process to minimize sustainability impact. A case study is presented which computes the probability that the optimal maintenance scheme allowing more degradation will meet the CO\textsubscript{2}-eq emission reduction target of the UN Intergovernmental Panel on Climate Change (IPCC) by 2050. Then, on the network-level, this dissertation provides a formulation of sustainable development as a multi-objective problem with short-term and long-term objectives, and presents a multi-objective optimization framework for the sustainable development of transportation infrastructure networks. The maintenance and seismic retrofit of highway bridges of Santa Clara County, California, within the transportation network of San Francisco Bay Area are presented as case studies. The NSGA-ii genetic algorithm is used to search for the optimal maintenance and retrofit of the highway bridges within the network. A new fitness memorization technique is proposed with an improved NSGA-ii, which provides a robust evaluation of solutions in multi-objective stochastic optimization problems. Finally, this dissertation investigates how the introduction of autonomous vehicles could change the sustainable maintenance decision-making process, as an example of the potential impact of new technology on managerial actions towards sustainable development. The improvement in road capacity by introducing autonomous passenger cars into the transportation systems is quantified using fundamental equations that characterize traffic flow. A case study is presented on the possible impact of autonomous vehicles on the San Francisco Bay Area transportation network and its sustainable maintenance decisions. A framework is proposed for robust decision-making on sustainable maintenance decision taking new technology advancement like autonomous driving into consideration.

Advisor: Lepech Michael primary advisor. Thesis advisor
Baker Jack W. advisor. Thesis advisor
Kiremidjian Anne S. (Anne Setian) advisor. Thesis advisor
Synthesis and Characterization of Open-Metal Site Grafting to Metal- Organic Frameworks for Solid Electrolyte Applications

In order for clean energy use to become a significant fraction of global energy use, the energy captured from sources such as wind and solar must be available for consistent use in spite of the daily and seasonal fluctuations in the availability of these resources. Lithium-ion batteries are a promising and prevalent technology for providing this energy storage, but these batteries suffer from degradation modes such as lithium plating and dendrite formation [1] that can shorten the battery’s lifetime and can create significant safety risks, such as battery fires during electric vehicle collisions. The liquid electrolyte in a Li-ion battery contributes significantly to the aforementioned degradation modes, [1] so replacing the liquid with a solid electrolyte can improve both the reliability and safety of energy storage in batteries. Metal-organic frameworks (MOFs) show promise as solid electrolyte materials because of their intrinsic porosity and ion-transport ability. However, the fundamental structure that enables ion transport has not been adequately studied to the extent of being able to optimize the system for ionic conductivity. Here we made progress in understanding how to synthesize and characterize MOFs for potential use in future electrolyte studies. We found that the characterization of the MOF can be impacted by the solvent and additives of synthesis, we learned that the introduction of salt to the MOF for ionic conduction occurs more readily in the absence of water, and we developed a procedure for the growth and characterization of single crystals of MOF-74 for characterization by single-crystal x-ray diffraction (XRD) that allows for full structure solving. These techniques and protocols for MOF characterization that we developed set the stage for a future of MOF solid electrolytes that are designed with their structure-property relationships in mind. Methods for the characterization of MOFs allow for structural information that is integral to their eventual incorporation into batteries as solid electrolytes and their contribution to the energy solution.
Reference:
1. Kyusung Park and John B. Goodenough, Adv. Energy Mater., 2017, 7.

Keywords: Metal-organic framework
solid polymer electrolyte
solid electrolyte
MOF-74
MOF
single-crystal XRD
PXRD
energy storage
battery
ion transport
lithium ion
lithium-ion grafting
grafting
single-ion transport
Thesis
Advisor: Bao Zhenan
Tarpeh William
Synthesis of Janus graphene for spatial separation of charges and reduction-oxidation reactions in colloidal photocatalysts [electronic resource]

Photocatalyst particles are attractive for many applications, but electron-hole recombination and surface back-reactions are major problems limiting their efficiency. These problems stem from short separation (~ nanometers) between reduction and oxidation (redox) sites in conventional systems. Here, we show that 2-dimensional Janus particles — Janus graphenes — can be used to spatially separate redox sites by large distances (~ micrometers) on opposite faces of conductive, atomically thin sheets. We used a silicon wafer and a polymer film to successively expose and protect alternate graphene oxide (GO) faces for asymmetric deposition of Pt and TiO2 nanocrystals, thus producing Janus graphene particles (Pt [vertical line] GO [vertical line] TiO2). We used electron microscopy of Janus graphene cross-sections to directly and conclusively show Pt and TiO2 particles on opposite faces of monolayer GO sheets. Spatial separation of redox sites in Pt [vertical line] GO [vertical line] TiO2 — dispersed in liquid — was demonstrated by photoinduced, reductive deposition of Pd onto reduction sites. Although future scale-up of the synthesis is necessary, Janus graphenes could be synthesized with many photocatalytic materials and may provide a general system for spatial separation of redox sites in photocatalyst particles.

Keywords: Chemical Engineering.
Advisor: Cargnello Matteo primary advisor. Thesis advisor
Frank C. W. primary advisor. Thesis advisor
Bent Stacey advisor. Thesis advisor
Synthetic biology and life's imagined futures [electronic resource]

Synthetic biology, a postgenomic discipline that aims to make biology easy to engineer, is marked by bold claims about democratizing biotechnology and a distinctive attitude towards the natural world expressed in the figure of the biohacker. Analyzing the narrative and aesthetic frameworks that surround efforts to engineer life in both synthetic biology and science fiction, this dissertation argues that late- twentieth century science fiction introduces a new way of thinking about the relationship between life and technology -- and a new affective and aesthetic framing of biotechnology -- that is taken up in synthetic biology and related efforts to expand the tools of the field to nonprofessional biologists known as biohacking. It demonstrates the two-way influence between science fiction and developments in science and technology, drawing on the literary analysis of selected works of science fiction; textual analysis of scientific papers and popular science writing relating to synthetic biology; and participant-observation in a biohackerspace, attendance at synthetic biology conferences, and interviews with synthetic biologists.

Advisor: Heise Ursula K. primary advisor. Thesis advisor
Saldívar Ramón
McGurl Mark
Riskin Jessica advisor. Thesis advisor
Synthetic efficiency through strategic design [electronic resource] : (I) the design and development of novel reactivity regenerating reagents for step economy, (II) the supply-impacting total synthesis of bryostatin 1

Organic synthesis as a discipline is driven at the delivery of high-value molecular entities as research tools, therapeutic agents, reagents, and materials. The simple delivery of these entities, however, does not constitute a successful synthetic effort. Instead, synthetic chemists are in constant pursuit of ideal syntheses that minimize step counts, waste, and development and delivery time; yet maximize chemical yield, safety, and purity and quantity of the resulting outputs. Presented in this defense will be three strategies aimed at this overall goal of efficient synthetic strategies. First, the design and development of 1,2,3-butatriene equivalents will be discussed, including their enabling application to the synthesis of a novel class of staurosporine-inspired kinase inhibitors using a [5+2]/[4+2] tandem cycloaddition sequence. Using a related reactivity regeneration strategy, the second story in this defense demonstrates the scalable synthesis of a new solvatochromic fluorophore enabled by the development of two new tetramethyleneethane equivalents. Finally, a scalable and supply-impacting synthesis of the marine macrolide bryostatin 1, a lead compound for the treatment of Alzheimer's disease and cancer, as well as for the eradication of HIV/AIDS, will be described. This synthesis represents a solution to the supply of bryostatin 1 and related analogs and enables further clinical and academic research on the potential of these transformative PKC modulators. Overall, these three stories serve as a demonstration of how strategic design strategies can contribute to the overall synthetic efficiency and economy of a synthetic sequence.

Keywords: Chemistry.
Advisor: Wender Paul A. primary advisor. Thesis advisor
Kanan Matthew William
Waymouth Robert M. advisor. Thesis advisor
Synthetic studies toward pactamycin using oxidative alkene and C-H amination technologies [electronic resource]

Selective, oxidative methods for C--N bond formation have been advanced to facilitate a de novo synthesis of pactamycin. A method for the synthesis of 1,2-diamines was developed through a single-step, tandem sequence involving Rh-catalyzed alkene aziridination followed by NaI-promoted rearrangement to an isomeric cyclic sulfamide. Facile ring opening of these products in hot water and pyridine affords differentially protected vicinal diamines. The utility of the method was validated through the preparation of the polyaminoacid-derived natural products, (±)-enduracididine and (±)-allo-enduracididine. A strategy has been delineated toward a synthesis of pactamycin enabled by alkene and C--H amination technologies. Two synthetic routes to the five-membered carbocyclic core of pactamycin were developed, the first utilizing an intramolecular benzoin reaction that enabled access to advanced intermediates for testing the key amination reactions. A second approach proceeded without recourse to protecting groups and makes possible access to enantioenriched material. Efforts to assemble the C1, C2, C3 triamino motif of the cyclopentane core are highlighted by a late-stage Rh-catalyzed chemoselective allylic C--H amination reaction and a Rh-catalyzed intramolecular alkene aziridination. Different approaches for assembling the C1, C2 cis-diamine, including use of the Rh-catalyzed aziridination and subsequent isomerization, are described. In the course of these studies, the core of the C2-epi-pactamycate, which bears all of the requisite nitrogen and oxygen functional groups to the epimeric natural product, was successfully synthesized.

Keywords: Chemistry.
Advisor: Du Bois Justin primary advisor. Thesis advisor
Stack T. (T. Daniel P.)
Trost Barry M. advisor. Thesis advisor
Systematic Study of Promoting Effects in Titania-Based Systems for Hydrogen Production in Photoreforming Reactions

There is a pressing need in society to begin to move away from fossil fuels as our main source of
energy due to the production of CO2 caused by their combustion. One promising alternative energy
vector is hydrogen, which burns cleanly in fuel cells, producing only water as a byproduct. Yet,
currently more than 95% of hydrogen is produced through steam reforming fossil fuels in a process
which releases significant amounts of carbon dioxide. A promising alternative to this process is
photoreforming of biomass (i.e. glycerol and glucose) to produce hydrogen and CO2 in a net carbon
neutral cycle which uses only the energy from the sun. TiO2 (titania) is a potential photocatalyst for
this process, but it has issues due to the fast recombination of electron-hole pairs after excitation.
Studies have shown that depositing different metal (i.e. Pd, Pt, Au) nanocrystals on the TiO2 helps
prevent recombination by serving as electron sinks and thus increases catalytic efficiency. In this
study, we used palladium nanocrystals as a co-catalyst with the titania. To further reduce
recombination, we also deposited different metal oxides (MnOx, NiOx, CoOx) to act as hole
collectors and thus promoting agents for the oxidative reaction in order to minimize recombination.
Our results demonstrated a decrease in catalytic activity throughout various deposition techniques
leading us to conclude that the metal oxide co-catalysts were detrimental to catalytic activity at the
concentrations tested (3-10 wt%), possibly due to obstruction of the TiO2’s active surface area.

Keywords:  Department of Chemical Engineering
Chemical Engineering
Stanford University
Undergraduate Honors Thesis
Cargnello Lab
photocatalysis
hydrogen production
titanium dioxide
metal oxides
Thesis
Advisor: Cargnello Matteo
Frank Curt
Tax Responsiveness of the Rich: Revisiting Evidence from Executive Compensation

This paper measures the responsiveness of taxable income to changes in the marginal tax rate using panel data on executive compensation since 1992. It exploits variation
from four tax acts: the Omnibus Budget Reconciliation Act of 1993, the Economic
Growth and Tax Relief Reconciliation Act of 2001, the Jobs and Growth Reconciliation Act of 2003, and the American Taxpayer Relief Act of 2012. Stock options have increased significantly as a share of compensation since 1992. I revisit results on the
responsiveness of executives given this trend towards the use of options, and find a
small short-run elasticity for executives, a larger short-run elasticity for CEOs specifically, and no long-run elasticity for either group.

Keywords:  Department of Economics
executive compensation
elasticity of taxable income
tax policy
Stanford Department of Economics
Thesis
Advisor: Shoven John
Teaching machines to converse [electronic resource]

The ability of a machine to communicate with humans has long been associated with the general success of AI. This dates back to Alan Turing's epoch-making work in the early 1950s, which proposes that a machine's intelligence can be tested by how well it, the machine, can fool a human into believing that the machine is a human through dialogue conversations. Despite progress in the field of dialogue learning over the past decades, conventional dialog systems still face a variety of major challenges such as robustness, scalability and domain adaptation: many systems learn generation rules from a minimal set of authored rules or labels on top of handcoded rules or templates, and thus are both expensive and difficult to extend to open-domain scenarios. Meanwhile, dialogue systems have become increasingly complicated: they usually involve building many different complex components separately, rendering them unable to accommodate the large amount of data that we have to date. Recently, the emergence of neural network models the potential to solve many of the problems in dialogue learning that earlier systems cannot tackle: the end-to-end neural frameworks offer the promise of scalability and language-independence, together with the ability to track the dialogue state and then mapping between states and dialogue actions in a way not possible with conventional systems. On the other hand, neural systems bring about new challenges: they tend to output dull and generic responses such as ``I don't know what you are talking about"; they lack a consistent or a coherent persona; they are usually optimized through single-turn conversations and are incapable of handling the long-term success of a conversation; and they are not able to take the advantage of the interactions with humans. This dissertation attempts to tackle these challenges: Contributions are twofold: (1) we address new challenges presented by neural network models in open-domain dialogue generation systems, which includes (a) using mutual information to avoid dull and generic responses; (b) addressing user consistency issues to avoid inconsistent responses generated by the same user; (c) developing reinforcement learning methods to foster the long-term success of conversations; and (d) using adversarial learning methods to push machines to generate responses that are indistinguishable from human-generated responses; (2) we develop interactive question-answering dialogue systems by (a) giving the agent the ability to ask questions and (b) training a conversation agent through interactions with humans in an online fashion, where a bot improves through communicating with humans and learning from the mistakes that it makes.

Advisor: Jurafsky Dan
Brunskill Emma advisor. Thesis advisor
Potts Christopher
Techniques for proving data structure lower bounds [electronic resource]

We present several techniques for proving the nonexistence of "too- efficient" data structures. Then we apply these techniques to prove lower bounds for three data structure problems: dynamic interval union, 2D weighted orthogonal range counting, and 2D orthogonal range parity.

Advisor: Reingold Omer primary advisor. Thesis advisor
Williams Ryan (Richard Ryan)
Valiant Gregory advisor. Thesis advisor