VictorJuiz/thesis huggingface dataset:
Modern Low-Complexity Capacity-Achieving Codes For Network Communication

Communication over unreliable, interfering networks is one of the current challenges inengineering. For point-to-point channels, Shannon established capacity results in 1948, and it took more than forty years to find coded systems approaching the capacity limit with feasible complexity. Significant research efforts have gone into extending Shannon's capacity results to networks with many partial successes. By contrast, the development of low-complexity codes for networks has received limited attention to date./nThe focus of this thesis is the design of capacity-achieving network codes realizable by modern signal processing circuits. For classes of networks, the following codes have been invented on the foundation of algebraic structure and probability theory: i ) Broadcast codes which achieve multi-user rates on the capacity boundary of several types of broadcast channels. The codes utilize Arýkan's polarization theory of random variables, providing insight into information-theoretic concepts such as random binning, superposition coding, and Marton's construction. Reproducible experiments over block lengths n = 512, 1024, 2048 corroborate the theory; ii ) A network code which achieves the computing capacities of a countably infinite class of simple noiseless interfering networks. The code separates a network into irreducible parallel sub-networks and applies a new vector-space function alignment scheme inspired by the concept of interference alignment for channel communications. New bounds are developed to tighten the standard/ncut-set bound for multi-casting functions./nAs an additional example of low-complexity codes, reduced-dimension linear transforms and convex optimization methods are proposed for the lossy transmission of correlated sources across noisy networks. Surprisingly, simple un-coded or one-shot strategies achieve a performance which is exactly optimal in certain networks, or close to optimal in the low signal-to-noise regime relevant for sensor networks.

Advisor: Gastpar, Michael
Nanomaterials processing toward large-scale flexible/stretchable electronics

In recent years, there has been tremendous progress in large-scale/nmechanically flexible electronics, where electrical components are/nfabricated on non-crystalline substrates such as plastics and glass. These devices are currently serving as the basis for various applications such as flat-panel displays, smart cards, and wearable electronics./n/nIn this thesis, a promising approach using chemically synthesized/nnanomaterials is explored to overcome various obstacles current technology faces in this field. Here, we use chemically synthesized semiconducting nanowires (NWs) including group IV (Si, Ge), III-V (InAs) and II-IV (CdS, CdSe) NWs, and semiconductor-enriched SWNTs (99 % purity), and developed reliable, controllable, and more importantly uniform assembly methods on 4-inch wafer-scale flexible substrates in the form of either parallel NW arrays or SWNT random networks, which act as the active components in thin film transistors (TFTs)./nThusly obtained TFTs composed of nanomaterials show respectable/nelectrical and optical properties such as 1) cut-off frequency, ft ~ 1 GHz and maximum frequency of oscillation, fmax ~ 1.8 GHz from InAs parallel NW array TFTs with channel length of ~ 1.5 μm, 2) photodetectors covering visible wavelengths (500-700 nm) using compositionally graded CdSxSe1-x (0 < x < 1) parallel NW arrays, and 3) carrier mobility of ~ 20 cm2/Vs, which is an order of magnitude larger than conventional TFT materials such as a-Si and organic semiconductors, without sacrificing current on/off ratio (Ion/Ioff ~ 104) from SWNT network TFTs./nThe capability to uniformly assemble nanomaterials over large-scale/nflexible substrates enables us to use them for more sophisticated/napplications. Artificial electronic skin (e-skin) is demonstrated by laminating pressure sensitive rubber on top of nanomaterial-based active matrix backplanes. Furthermore, an x-ray imaging device is also achieved by combining organic photodiodes with this backplane technology.

Advisor: Javey, Ali
Essays in the Economics of Emigration and the Lifecycle Deficit in Ethiopia

Abstract/nEssays in The Economics of Emigration and The Lifecycle Deficit in Ethiopia/nby/nTeferi Mergo/nDoctor of Philosophy in Economics/nUniversity of California, Berkeley/nProfessor Ronald Lee, Chair/nThis work explores the effects of international migration on sending families, and the lifecycle deficit in Ethiopia. The first two chapters examine the effects of emigration on the living standards and health of the sending families, using (for identification) the Diversity Visa (DV) lottery program - a migration channel through which about a million people have relocated to the US since 1995. The random assignment of migration opportunities allows estimation of experimental treatment effects./nIn chapter 1, I use data from a survey of Ethiopian DV participants to study the causal effects of emigration. I infer that migration contributes positively to the wellbeing of source families. Overall, migrant sending families spend about 22% more on food and 41% more on energy, reflecting their improved standard of living. They have better quality durables, drinking water and sanitation facilities. However, migration does not improve the senders' saving, bank use and business ownership. The positive treatment effects do not diminish with longer stay of emigrants abroad. Migrant men contribute more to the increase in their families' standard of living than their female counterparts do. I find that DV participants are favorably selected relative to the overall population./nIn chapter 2, I exploit the survey on Ethiopian DV participants (lottery winners and non-winners) to explore the health effects of emigration on those left behind. I find that the health effects of emigration are mixed. Migration increases overall BMI of those remaining behind by 0.56, contributing affirmatively to physical health of about 80% of them, while causing an uptick in the obesity rate by 5%. It increases the incidence of vascular diseases and diabetes by 10%, and has adverse effects on the mental health of the migrant senders. Adults fare poorly in terms of the less desirable health effects of migration./nChapter 3 estimates the support ratio for Ethiopia, using the US Census Bureau's population projections by age and the method developed by the National Transfer Accounts (NTA), which employs the age-profiles of labor income and consumption. Ethiopia has a labor income profile with high youth and old-age earnings, much like a typical poor agrarian country with low savings, low levels of upward public transfers and low levels of schooling. Interestingly, private consumption declines more than moderately in the country with age, beginning in the early 30's, implying that poverty might be pronounced in older age groups. The average Ethiopian consumes more than s/he produces for roughly half the number of years s/he can expect to live. The support ratio for Ethiopia is expected to increase for another generation or so, potentially augmenting its per-capita income.

Advisor: Lee, Ronald
Isoperimetry and noise sensitivity in Gaussian space

We study two kinds of extremal subsets of Gaussian space:/nsets which minimize the surface area, and sets which minimize the noise sensitivity./nFor both problems, affine half-spaces are extremal: in the case of surface area,/nthis is was discovered independently by Borell and by Sudakov and Tsirelson in the 1970s;/nfor noise sensitivity, it is due to Borell in the 1980s./nWe give a self-contained treatment of these two subjects,/nusing semigroup methods. For Gaussian surface area, these methods were developed by/nBakry and Ledoux, but their application to noise sensitivity is new./n/nCompared to other approaches to these two problems, the semigroup method has the/nadvantage of giving accurate characterizations of the extremal and near-extremal sets./nWe review the Carlen-Kerce argument showing that (up to null sets) half-spaces are the/nunique minimizers of Gaussian surface area. We then give an analogous argument/nfor noise sensitivity,/nproving that half-spaces are also the unique minimizers of noise sensitivity./nUnlike the case of Gaussian isoperimetry, not even a partial characterization of/nthe minimizers of noise sensitivity was previously known./nAfter characterizing the extremal sets, we study near-extremal sets. For both surface/narea and noise sensitivity, we show that near-extremal sets must be close to half-spaces./nOur bounds are dimension-independent, but they are not sharp./n/nFinally, we discuss some applications of noise sensitivity: in economics, we/ncharacterize the extremal voting methods in/nKalai's quantitative version of Arrow's impossibility theorem. In computer science,/nwe characterize the optimal rounding methods in Goemans and Williamson's semidefinite/nrelaxation of the Max-Cut problem.

Advisor: Mossel, Elchanan
The Development of Semiconducting Materials for Organic Photovoltaics

The chemical structure of conjugated semiconducting materials strongly influences the performance of organic photovoltaic (OPV) devices. Thus a good understanding of the structure-function relationships that govern the optoelectronic and physical properties of OPV materials is necessary. In this dissertation, organic polymers and small molecules are evaluated in terms of OPV device output parameters, and molecular design rules are elucidated./nThe development of molecules with alternating electron-rich and electron-deficient backbone units provides materials with suitable optoelectronic properties for OPVs and favorable modularity for organic semiconductor design. The choice of specific aromatic units and side chains for conjugated materials are shown to modulate the energy levels and architecture of OPV devices, affecting each of the four mechanistic steps of OPV operation./nIn Chapter 2, the relationship between molecular packing parameters and the bulkiness of aliphatic solubilizing group extending away from a polymer backbone is elucidated, and high-performance OPV devices are achieved. In Chapter 3, the inclusion of a post-processing functionality on a polymer side chain is found to have a positive effect on the bulk morphology and overall performance of OPV devices. In Chapter 4, the influence of electron-withdrawing and quinoidal monomers on the optoelectronic properties of conjugated polymers is established, and energy level modulation is shown to affect the electron accepting and donating capabilities of OPV materials in a blended device. In Chapter 5, small molecules are designed with complementary light absorption properties in order to investigate a rarely observed charge generation mechanism.

Advisor: Fréchet, Jean M. J.
Tradeoffs between Costs and Greenhouse Gas Emissions in the Design of Urban Transit Systems

Public transit is often touted as a "green" transportation option and a way for users to reduce their environmental footprint by avoiding automobile emissions. Many transit systems, however, have considerable emissions, and when vehicles run with ridership significantly below capacity, the per-passenger-kilometer emissions can be greater than for automobile. Efforts to reduce public transit emissions have centered on shifting users from more polluting modes and improving technology either by retrofitting existing vehicles or replacing them with more efficient models. I explore an approach to optimizing the design and operations of transit systems for both costs and emissions using continuum approximation models. The research identifies the Pareto frontier for designing an idealized transit network, and compares transit modes, including bus, bus rapid transit, light rail, and metro heavy rail, over four city scenarios. The slope at any point on the Pareto curve represents the cost of decreasing emissions by another unit, and this can be used to identify an emissions level that is equal to the market value of carbon. Further, I explore how the level of service for users impacts emissions: first, comparing modes at a given emissions level to see which provides the best service to users in terms of average travel time; second, incorporating travel time elasticities into the optimization to allow demand to reduce subject to increases in the travel time. Results of the parametric analysis suggest that a BRT system is a low cost and low emissions transit option for many types of cities. Choosing GHG reduction levels based on the market price of carbon has a small impact on user travel time, so further reductions may be reasonable. In general, the lowest-cost mode will provide the fastest travel time to users at a given emissions level. When shifting demand is accounted for, emissions reductions are moderated, but not eliminated, by the increase in automobile emissions when users are relatively inelastic. Including automobile emissions in the optimization shifts the problem from the agency to the city perspective and produces results that can avoid the unintended emissions consequences associated with users changing modes. This research provides a strategic framework for transit agencies to cost-effectively reduce GHG emissions, demonstrating how operational and network changes can be used to reduce the costs and emissions of a transit system. The methods can be used to estimate the system cost of GHG emissions reductions to facilitate comparison with other approaches, such as vehicle replacement or engine upgrades. One can identify the scale of reasonable reductions and estimate the net effect on emissions as service is reduced and users switch modes.

Advisor: Madanat, Samer M
Horvath, Arpad
Family Structure and Child Health in Cambodia, 2000-2010

In developing countries, where there are limited resources and social support, children rely primarily on their family for their well-being. Their lives are affected by the configuration of household members, by the type of family structure, and by household decision processes that determine the resources that are allocated for their well-being. This dissertation examines the influence of family structure on the outcomes of children's well-being, using the case of Cambodia, where between 2000 and 2010 the children composed more than a third of the population./nTo assess the link between family structure and the well-being of children in Cambodia, this dissertation uses multilevel modeling. It examines three aspects of well-being. The first is the amount of time invested on children. The second examines the nutritional status of children. The third is the risk of infant mortality. In this investigation I focus on two forms of family structure: nuclear and multigenerational. For our purposes, a multi-generational household is one containing one or more grandparents./nTo consider the investment of time, I take advantage of time-use data collected by the Cambodia Socio-Economic Survey and assess time spent on childcare individually and collectively by members of the household. My analysis reveals that children in multigenerational households receive more childcare time than those in nuclear households. Moreover, the additional care time these children receive is due to the presence of grandparents. Grandparents supplement maternal care time./nTo assess the nutritional status of children in Cambodia, I use three waves of the Cambodia Demographic and Health Survey from 2000, 2005 and 2010. My findings reveal that children in multigenerational households have better nutritional outcomes than children in nuclear households. The gains of children in multigenerational households increased over the decade. This finding suggests that even though national economic development improves the overall health status of children, those coresiding with grandparents are the most advantaged./nTo detect possible influences of family structure on infant and child mortality, I explore whether or not the health advantage of children in multigenerational households extends to a survival advantage. Findings reveal that even in the earliest stages of life, the presence of grandparents safeguard infant survival more than the presence of a father in the household.

Advisor: Wachter, Kenneth W
Needs-Satisfaction, Motivation, and Achievement in High School Students: Testing Predictive Models by Gender and Ethnicity

Student motivation is one proposed contributing factor to disparate rates of high school achievement. Guided by self-determination theory (SDT; Ryan & Deci, 2000a), the purpose of the present study is to investigate whether a process model of the relationship between motivation and achievement varied by gender and racial subsamples of students within one large high school (see Figure 1). First, I examined the reliability and structural validity of the measures within the model. Second, I examined the extent to which the climate of one large urban high school was related to individual perceptions of autonomy, competence, and relatedness across gender and racial/ethnic subgroups. Then, I used structural equation modeling to test a process model in which autonomous motivation mediated the relationship between perceived climate or needs-satisfaction and achievement (with and without accounting for prior year achievement). The sample consisted of 863 students from an urban high school in the Western United States. The reliability and structural validity for the Basic Psychological Needs Scale (BNS) were below acceptable ranges, whereas the reliability and structural validity for the Academic Motivation Scale (AMS) were within the acceptable ranges. The relationships among needs-satisfaction, autonomous motivation, and achievement were not fully consistent with SDT; that is, competence and relatedness were significantly related to achievement (r = .20, r = .19, respectively, p < .01) whereas autonomy was not (r = .09, p > .01). European American and Asian American students showed significantly and meaningfully higher mean-level GPA than African American and Latino students, whereas differences among groups in needs-satisfaction and autonomous motivation were not both meaningful and significant. The process model without prior achievement explained 1% of the variance in achievement and fit indices approached acceptable ranges, whereas the model with prior year achievement showed unacceptable fit indices. This study highlights the importance of valid and reliable measures of psychological constructs before examining their relationships to achievement. Additionally, the value of studying hypothesized models across gender and racial subsamples is demonstrated. Lastly, this study illuminates the importance of continually testing theories, even those that are relatively well established.

Advisor: Worrell, Frank C.
Secular Regimes and State Engagement with Religion in post-Soviet Eurasia

The post-Soviet region is the only area of the world in which every state is secular. Since independence in 1991, each of the 15 states has formally declared its secular nature; however, they have had drastically different policies towards religion. The Baltic states and Ukraine have relatively liberal policies in which religious groups and people are more or less free to operate without much restriction. In Armenia, Russia, Moldova and Georgia there is a certain level of cooperation between the state and religious groups, including state subsidies or formal support for religions of declared people or nations. In the Central Asian countries, Azerbaijan and Belarus, the state poses considerable regulations and restrictions on religion, and controls religious activities by incorporating (or subjugating) religion into the state order./nThis project analyzes the determinates of the level of state engagement with religion (SER) in the 15 post-Soviet countries, with special focus on Estonia, Georgia and Uzbekistan as three examples of countries with low, medium and high SER, respectively. It examines SER in terms of state funding for religion, use of religious symbols by the state, formal incorporation of religion into the state, and regulations and restrictions placed on religion. The project assesses several possible explanatory variables (i.e. regime type, economic development, predominant religion and religious fractionalization), and shows SER is impacted by regime type, predominant religion, and presence or absence of consensus between secular leaders and religious authorities in each country during the state-building period after 1991./nThis study is the first systematic comparative analysis of secular state regimes and SER across the 15-post-Soviet countries. The project also provides more explanatory power to the term secular state and shows that there are a variety of secular states throughout the world. Finally, the research connects this region with the vast body of literature on state-religion relations from which it is has been largely absent.

Advisor: Fish, M. Steven
Contemporary Modernity and 'Death Ethics': Antecedents and Impacts of Western Expansion as War in the Northern Plains, 1820 - 1880

In the broadest sense, the dissertation identifies the "death ethics of war" during Western expansion of the United States, its claims to exceptionalism, and its enduring legacies in Native American contexts historically and today. The logic of Western European expansion in the Americas can be argued to have exemplified the theory the "death ethics of war". I engage Nelson Maldonado-Torres's articulation of the "death ethics of war" to identify the political logics behind the normalization of genocide in western expansion. I argue that its gendered dimensions engendered violence against Native Americans and fostered an anti-"Indian" logic that traversed the historical boundaries of its inception and became embedded in American institutional and social imaginaries. As one of the most enduring legacies of colonialism, anti-"Indianism" was enabled by racial and gendered logics that permeated the laws and discourses of colonial expansion and became part-and-parcel of the Western imaginary largely through popular culture mediums. The resulting compulsory subject formations established the ostensibly natural human difference between "Indians" and Western European civilizations and in doing so negated the humanity of Native Americans while substantiating the incomparable superiority of Western European and "white" settler societies in America. It was a paradigm, I argue, that continues to underpin Western modernity, American social relationships, and ultimately the systemization of differential political justice for Native Americans in the United States./nI centralize the 1864 Sand Creek massacre because it is one of the highest points of state sanctioned anti-"Indian" violence in during Western expansion on record. Because of the inhumane violence exacted by American military personnel who perpetrated the massacre, the Sand Creek massacre most clearly exemplifies how Western expansion was infused with "death ethics" that facilitated epistemological and literal forms of death in the Native American context. In response to the enduring legacies of anti-"Indianism," the activism of Native American women across the U.S. exemplifies the "ethics of revolutionary love". I employ Dr. Patricia Penn Hilden's theory of the "Red Zone," which identifies Native American activism as a political and spatial consciousness. I explore the myriad life-affirming efforts of Native American women activists to combat and ameliorate the negative effects of contemporary anti-"Indianism".

Advisor: Penn Hilden, Patricia
Maldonado-Torres, Nelson