VictorJuiz/thesis huggingface dataset:
A modulation spectra approach to sound texture analysis and synthesis [electronic resource]
Keywords: Electrical Engineering.

What information is perceived when listening to the sound of flowing water, blowing wind or crackling fire? These are examples of a class of sounds that are characterized as textures, because their frequency and temporal attributes are irregular and difficult to resolve, yet retain overall stability. Sound textures contain more structure than filtered noise and thus are not well modeled as such. Tonal methods often used for speech or music do not work well either. A better understanding of sound textures can provide insights into our auditory process, and the information extracted from auditory inputs. But to do so, it is necessary to find a quantitative representation of the added information. In this dissertation, various representations used for audio signal processing are investigated. This leads us to a carrier-modulator view of signals. For modeling the modulator, we find that modulation spectra captures the sound texture information in a compact representation. Based on this approach, we define a feature set that captures the information of sound textures. The derive features are relatively independent and are intuitive to understand. We present a system that extracts the feature set from a sound texture example and uses the extracted feature set to synthesize new samples. Through a listening test it is shown that the proposed feature set and analysis- synthesis method improves sound texture resynthesis compared to state-of-the-art method. Noticeably, our proposed method improves the resynthesis of sound textures with tonal components. Our method also works for long term stable instrument sounds, sounds not conventionally thought to be sound textures. Our study in sound texture further shows the importance of modulation in auditory perception. Such knowledge can be used to find sparse representations of sounds and be applied to data compression, machine-hearing applications and improve audio analysis-synthesis methods. It also gives insight into the perception of timbre.
Molecular and functional profiling of antigen-driven B-cell responses at single cell resolution in autoimmunity and infectious disease [electronic resource]
Keywords: Immunology.

Innovations in deep sequencing have enabled the analysis of single cell transcriptomes and immune repertoires in immune cell populations. Despite this, the mechanisms underlying humoral responses in many autoimmune and infectious diseases contexts remain poorly understood due to technical limitations that prevent the characterization of relationships between immune receptor and transcriptome as well as functional analyses of prominent antibodies. Here, we develop and utilize next-generation sequencing approaches to understand B-cell responses in patients with rheumatoid arthritis and in patients with Staphylococcus aureus infection. First, we utilize a novel single-cell RNA-seq approach that enables simultaneous transcriptomic profiling and B-cell receptor (BCR) reconstitution to analyze subset-specific dysregulation in tetramer-positive B cells from RA patients that target RF (RF) and citrullinated proteins (ACPA). We find that B cells in naive, memory, and plasmablast stages all target RF and ACPA, indicating mechanisms of defective central and peripheral tolerance. We also elucidate affinity maturation gene signatures, innate immune signatures, and coexpression pathways that differentiate the RF and ACPA responses, demonstrating that unique costimulatory pathways are required for different autoantigen responses. Second, we perform deep sequencing of paired IgG plasmablast antibody repertoires in Staphylococcus aureus bacteremia patients who eventually recovered from infection to identify rapidly expanding B cell clones during infection and enable rational selection of antibodies for recombinant expression. Through functional characterization of antibodies from S. aureus patients, we identify fibronectin binding protein A as a prominent antigen in productive humoral responses and show that recombinant antibodies promote opsonophagocytosis. Taken together, these studies demonstrate the ability of single cell B-cell analyses to uncover the functional heterogeneity of the humoral response, characterize transcriptional profiles at different stages of B-cell differentiation, and identify antigens targeted by the active antibody response.
Molecular design of hybrid materials for novel mechanical properties [electronic resource]
Keywords: Materials Science and Engineering.

Hybrid molecular materials are an important class of nanomaterials as the combination of organic and inorganic species at the molecular scale leads to novel properties and functionalities. However, designing hybrids to maintain high levels of mechanical strength and stiffness remains a significant challenge that can ultimately limit their integration into emerging nanotechnologies including dielectrics in microelectronics, antireflective (AR) coatings, protective coatings in flexible electronics, and molecular sieves for biosensing. Before strategies can be proposed to enhance the mechanical integrity of these materials, their fundamental properties must be understood. As a result, the discovery of elastic and thermal expansion asymmetries (these materials have different mechanical properties in compression and tension) is introduced, which has significant implications for thermomechanical reliability. The underlying atomistic/molecular-level mechanism is developed and molecular design strategies are presented on how to control these asymmetries. After establishing the fundamental properties of these materials and their connection to molecular structure, a new molecular design principle is introduced for these materials to achieve exceptional mechanical properties: hyperconnected network architectures. Here, the key innovation is to understand how the intrinsic molecular structure can be designed to enhance network connectivity beyond an atom's chemical coordination number. This results in mechanically robust hybrid materials (e.g. hybrids with significantly lower density but higher stiffness than fully dense silica), a vital step towards their successful integration into emerging nanotechnologies.
Moments and zeros of L-functions over function fields [electronic resource]
Keywords: Mathematics.

In this thesis we study some questions related to L-functions over function fields. We obtain asymptotic formulas for the first four moments of the family of quadratic Dirichlet L-functions, when the size of the finite field is fixed and the genus goes to infinity. For the first moment we also compute an explicit lower order term of size approximately the cube root of the main term. In joint work with Hung Bui, we study low-lying zeros in the same family of L-functions. For the one-level density of zeros, we detect a lower order term when the support of the Fourier transform of the test function is sufficiently restricted. We also compute the pair correlation of zeros and obtain a non-vanishing result and a lower bound for the proportion of simple zeros in the family.
Monolithic three-dimensional integration of III-V compound semiconductors on silicon [electronic resource]
Keywords: Electrical Engineering.

The planar scaling of silicon-based electronics technology has become much more challenging. Stacking devices in the vertical direction provides possible better performance and higher device density. Integrating different electronic or even optical components on top of silicon integrated circuits (ICs) can realize multi-functional ICs or ultimately, a system-on-chip. III-V semiconductor compounds have been used in optoelectronics and are also promising candidates for alternative channel materials in the next generation complementary-metal-oxide-semiconductor (CMOS) technology. Hetero-integration of high quality III-V single crystals on top of Si ICs will enable a wide variety of applications. However, there are three major challenges in building monolithic 3-dimensional integration circuits (3DICs): obtaining single crystalline device-grade semiconductor films; transfer of these films on to prefabricated silicon wafers; and fabricating devices that are compatible with existing structures in the silicon wafer. A possible experimental solution is to use the rapid-melt-growth (RMG) method to prepare single crystalline materials on silicon, which could solve the first two challenges together. In the first part of this dissertation, a modified RMG process is proposed and examined specifically for GaSb and InAs growth on silicon in order to solve the low III-V single crystalline yield problem using the conventional RMG method. Several possible causes of the low yields in the process design and conditions are identified, and experimental solutions are given. The geometry dependence of the RMG structure and the scaling potential are also discussed. III-V MOSFETs using the RMG-grown GaSb and InAs crystals are then fabricated to demonstrate the viability of 3DIC hetero-integration, under low thermal-budget (< 400oC) constraints. The second issue discussed in this work is using the wafer bonding method to realize monolithic 3D integration. Comparisons between wafer bonding and the RMG approach are made.
Monotone interactions of random walks and graphs [electronic resource]
Keywords: Statistics.

This thesis deals with the behavior of random walks on monotonically time-varying graphs, where due to this monotonicity we can establish certain universality properties. In Chapter 1, we consider normally reflected Brownian motion (RBM) and simple random walk (SRW) on independently growing-in-time d-dimensional domains, d> =3. We establish a sharp criterion for recurrence versus transience in terms of the growth rate. For more general growing subgraphs of an infinite graph, we use evolving sets to establish heat kernel bounds that yield sufficient transience/recurrence criteria. In contrast, we demonstrate rich and non-universal behavior of certain non-Markovian models of random walks, in which monotone interaction enforces domain growth as a result of visits by the walk (or probes it sent), to the neighborhood of domain boundary. This is complemented by Chapter 2, where we address stability issues for random walks among time-dependent conductances. For both the discrete-time uniformly-lazy and continuous-time constant-speed random walks (DTRW/CSRW), we show that Gaussian heat kernel estimates are not stable under perturbations. As a by-product, we refute an open question about inhomogeneous merging of finite Markov chains. We establish matching Gaussian upper and lower transition density bounds for the CSRW among time-increasing conductances on any graph satisfying a uniform-in-time Poincare inequality and volume growth regularity. In contrast, stability is known for the variable-speed random walk (VSRW), for which the counting measure is the reversing measure.
Mountains and messiahs [electronic resource] : the Roshaniyya, revelation, and Afghan becoming
Keywords: Religious Studies.

This dissertation analyzes a sixteenth-century Sufi messianic movement known as the Roshaniyya ("the illuminated ones") popular among the Afghan communities of the northwestern regions of the Mughal Empire. While the Roshaniyya under the leadership of Bayazid Ansari and his family clashed with Mughal armies, there was a more profound contest over the nature of language and divine revelation. How does a "vernacular" language become the language of God? By telling a history of the "practice of revelation" amid the Afghan highlands, this project rejects the over-reliance upon tribe and ethnicity as explanatory categories that isolate the Roshaniyya movement. Rather, through an immanent reading of Roshani texts and the text of their critics, this project traces rival ideologies of language and temporality, demonstrating the significance of these contests in the emergence of new imaginings of Afghan identity and the role of Pashto. The Roshaniyya experimentation with language reveals a community that engaged the Qur'an and the concept of revelation as an open, continuous phenomenon that could be grasped through dhikr practice, narratives of dreams and saints, and literary techniques such as repetition, imitation, and rhyme. The Roshaniyya thus offer both a demonstration of the participation of Afghans in larger, Persianate religio-cultural trends as well as a striking example of the diverse ways premodern Muslims engaged the Qur'an and prophetic history. This dissertation also analyzes sources from a wide range of contexts that engage, critique, and remember the Roshaniyya in diverse ways for multiple ideological purposes. Among the sources considered are Mughal courtly chronicles, Persian biographical dictionaries, the reports of nineteenth-century British scholars and soldiers, and various works by a popular seventeeth-century heresiographer and Sunni scholar by the name of Akhund Darweza.
Multifunctional separators for improving battery safety [electronic resource]
Keywords: Materials Science and Engineering.

Rechargeable lithium-ion batteries have without a doubt transformed the world of portable electronics and consumer devices. However, recent high-profile failures of lithium-ion batteries caused by internal short-circuits have led to numerous fires and explosions. As the industry moves to higher energy-density electrode materials to satisfy consumer demand, the consequences and severity of failures will only increase. There is a clear need for improved safety mechanisms to enable the safe use of lithium-based batteries. Particularly for lithium metal electrodes where the continuous formation of dendrites during cycling increases the likelihood of failure by short-circuits. In this dissertation, I will discuss my work on developing in-situ detection and protection schemes using the battery separator as a platform. In the first part I will present an in-situ method for detecting the penetration of dendrites into the battery separator via a bifunctional separator with a conductive metal interlayer. Both metallic and carbon-based bifunctional separators are demonstrated with aluminum and carbon showing excellent stability in the battery environment. In the worst case scenario of a pinhole which extends through the entire separator, the advance warning preceding failure can be extended to several hours. In the second part, I will present a lithium cobalt oxide (LCO) coated separator which is demonstrated as a temperature sensor to reversibly and accurately measure the internal temperature of a battery. A heating fault is detected internally via the LCO separator as a 25C differential over the temperature measured at the cell surface. In the final section, the reaction of lithium with a silica nanoparticle-coated separator is demonstrated as a mechanism for suppressing the further growth of lithium dendrites which penetrate into the separator. This reaction-protective separator can greatly slow the growth of dendrites and extend the battery lifetime up to five times over traditional separators. Together these detection and protection schemes can be simultaneously used to improve the safety of lithium-based batteries.
Multilingual Students as Ethnographers: Toward a Culturally Sustaining Education Model for Elementary School Indigenous-Language Speakers
Keywords: Stanford School of Education
bilingual education
photovoice
ethnography
autoethnography
language ideology
culturally sustaining pedadogy
culturally responsive education
indigenous languages of Guatemala
Mayan languages
Mam
Kanjobal
Spanish
dual-immersion school
Thesis

Starting in the 1980s and 90s, indigenous Mayan communities began to form in the US. Many members of these communities speak a language besides English or Spanish natively and are subject to a number of social barriers and discrimination, including access to a quality education. Situated in a bilingual Spanish-English elementary school in the Pacific Northwest, the study explored the multilinguistic practices of nine 4th grade Mayan Mam speakers using PhotoVoice. After being asked to show “the languages of [their] lives,” students took photos using a disposable camera for a period of three weeks. Afterward, students were asked to select one photo each and participated in PhotoVoice interviews conducted in a group setting. Students were asked about the photo they selected, as well as more about their linguistic practices inside and outside of school. Using a combination of both a-priori and emergent codes, 102 photos in total were coded. The photos as well as recordings and transcripts of the PhotoVoice interviews and participant demographic information informed analysis. Analysis results showed student conceptions of Fishman’s sociolinguistic domains. Actual participant descriptions of place-based linguistic practices complicate this finding somewhat, suggesting that languages described by participants as separate may see considerable overlap in practice. The study also found that although Mam was not described as a language used in school by the students, Mam was incredibly present in the home and with family; furthermore, half of prompted participants expressed some interest in the possibility of using Mam in school in the future. Finally, although some students described the utility of Mam as a common language in order to help those who don’t speak another language, others described a preference for Mam as a motivating factor for use. Building on Martínez’ work on language ideologies, these findings suggest that although students did express attitudes that reflected dominant language ideologies whereby Mam is deemed a non-academic language, student interest in the use of Mam in school simultaneously challenges this notion. Therefore, some students articulated what Martínez refers to as counter-hegemonic language ideologies, in which a language is valorized in spite of its current subordination in society. These findings demonstrate the potential benefits of facilitating autoethnographic exploration of linguistic practices in the classroom, particularly in a culturally responsive context.
Multiphase Equilibrium Calculations with Gas Solubility in Water for Enhanced Oil Recovery
Keywords:  Department of Energy Resources Engineering
School of Earth Energy &amp; Environmental Sciences
Petroleum Engineering Program
Thesis

In this thesis, we have developed a robust algorithm for three phase compositional simulation of gas injection (especially CO2) in the presence of water. In this work, Henry’s law is applied to calculate component fugacities in the aqueous phase, while an equation of state (EOS) is used for the hydrocarbon vapor and liquid phases.
The basis of the algorithm is stability analysis in combination with phase split calculations. The stability analysis and phase split kernels can be framed as optimization problems. Specifically, stability analysis involves locating the minimum of the tangent plane distance function. The phase split calculation seeks to find the minimum Gibbs free energy of the system.
Successive substitution iteration method, Newton’s method and Trust Region method are applied to ensure robust and efficient computations. We tested two-phase cases and three-phase cases, and compared results with WinProp in CMG. Complex three-phase cases were also tested and phase diagrams were generated to verify our algorithm.
Multivariate methods for the analysis of structured data [electronic resource]
Keywords: Statistics.

We describe methods for incorporating information about variable structure in multivariate analysis. We are motivated by the example of microbiome data, where we have species abundances in addition to information about the evolutionary history of those species. However, the methods we develop are applicable to more general types of structure on the variables, and we expect to find many other applications both in biology and in other fields. We develop a method for structured dimensionality reduction, adaptive gPCA. This method allows for tunable incorporation of the variable structure, so that the fine-scale structure of the variables, the global structure, or anything in between can be brought out. We then move to the problem of incorporating sparsity in addition to the structure to obtain a sparse and structured PCA as well as sparse and structured discriminant analysis for classification problems. The primary motivation behind incorporating sparsity and structure together is to obtain more interpretable results, but we also show that incorporating these two elements can substantially improve classification accuracy in the supervised setting.
MyHood: Mapping Opportunities Around Every Corner
Keywords: civic engagement
design thinking
community
high school
map
mapping
empowerment
awareness
Thesis

Many high school mission statements involve transforming the youth into leaders of their community. Yet there appears to be a disconnect between school content and its application to the challenges in the youth’s community that results in a low-level sense of empowerment. MyHood addresses this gap by having the youth see themselves as critical thinkers and citizens fully engaged in the transformation of their communities.
Students are aware of conditions in their communities and opinionated about the changes they would like to see happen. Adolescents need to be able to uncover, explore, and discuss topics related to their territories as a means to engage with their communities and grow up involved in the solution of problems that matter to them. Instead of believing that changes are not possible – or only the government’s responsibility – these learners need to develop a positive, personal and in-depth relationship with the places they live in. By developing youth protagonism and civic engagement, MyHood seeks to give voice to young learners of underprivileged neighborhoods using the Design Thinking framework and digital mapping technologies.
The combination of such elements makes MyHood a distinctive and powerful platform for young underrepresented learners. First, maps help students develop a sense of place toward their own neighborhoods and a sense of belonging to larger urban areas. Using map layers, learners and users will be able to visualize their communities in a powerful, augmented way and, thus, learn to ask different questions and tell different, more critical stories about their lives. Second, learning the human-centered approach of Design Thinking will allow students to dive deep into other realities and different possibilities, developing a critical and mature stance towards reality.