VictorJuiz/thesis huggingface dataset:
Metamaterial-Inspired CMOS Tunable Microwave Integrated Circuits For Steerable Antenna Arrays
Keywords: tunable active inductors
phase shifters
directional couplers
steerable antenna arrays
metamaterials
CMOS MMIC

This thesis presents the design of radio-frequency (RF) tunable active inductors (TAIs) with independent inductance (L) and quality factor (Q) tuning capability, and their application in the design of RF tunable phase shifters and directional couplers for wireless transceivers. The independent L and Q tuning is achieved using a modided gyrator-C architecture with an additional feedback element. A general framework is developed for this Q- enhancement technique making it applicable to any gyrator-C based TAI. The design of a 1.5V, grounded, 0.13um CMOS TAI is presented. The proposed circuit achieves a 0.8nH-11.7nH tuning range at 2GHz, with a peak-Q in excess of 100. Furthermore, printed and integrated versions of tunable positive/negative refractive index (PRI /NRI) phase shifters, are presented in this thesis. The printed phase shifters are comprised of a microstrip transmission-line (TL) loaded with varactors and TAIs, which, when tuned together, extends the phase tuning range and produces a low return loss. In contrast, the integrated phase shifters utilize lumped L-C sections in place of the TLs, which allows for a single MMIC implementation. Detailed experimental results are presented in the thesis. As an example, the printed design achieves a phase of -40 to +34 degrees at 2.5GHz. As another application for the TAI, a reconfigurable CMOS directional coupler is presented in this thesis. The proposed coupler allows electronic control over the coupling coefficient, and the operating frequency while insuring a low return loss and high isolation. Moreover, it allows switching between forward and backward operation. These features, combined together, would allow using the coupler as a duplexer to connect a transmitter and a receiver to a single antenna. Finally, a planar electronically steerable patch array is presented. The 4-element array uses the tunable PRI/NRI phase shifters to center its radiation about the broadside direction. This also minimizes the main beam squinting across the operating bandwidth. The feed network of the array uses impedance transformers, which allow identical interstage phase shifters. The proposed antenna array is capable of continuously steering its main beam from -27 to +22 degrees of the broadside direction with a gain of 8.4dBi at 2.4GHz.
earPod: Efficient Hierarchical Eyes-free Menu Selection
Keywords: earPod
Human Computer Interaction
Computer Science
Interactive Techniques

The research in this dissertation developed and evaluated a new method for menuing interaction that is intended to be better suited than current methods with respect to mobile eyes-free scenarios. The earPod prototype was developed and then evaluated in a series of four experiments. In the first two experiments, earPod was first compared against an iPod-like (visual) interface and then against a fuller set of competitive techniques that included dual vs. single modality presentations, audio vs. visual modalities, and radial vs. linear mappings. The third experiment consisted of a longitudinal study designed to understand the learning patterns that occurred with these techniques. The fourth experiment examined performance in a conventional (single task) desktop setting and in a driving simulator (i.e., a dual task situation where participants carried out the driving task while interacting with the mobile device). The results of these experiments, comparing earPod with an iPod-like visual linear menu technique on fixed-sized static menus, indicated that earPod is comparable both in terms of speed and accuracy. Thus it seems likely that earPod should be an effective and efficient eyes-free menu selection technique. The comprehensive 3x2 study implemented in Experiment 2 showed that the benefit of earPod was largely due to the radial menu style design. While performance using it was comparable in both speed and accuracy with the visual linear menus, its performance was slower than for a visual radial style menu. In the multi-task simulated driving condition in Experiment 4, where concurrent tasks competed for visual attention, the eyes-free earPod interface was found to be beneficial in improving performance with respect to the safety related driving parameters of following distance and lateral movement in the lane. Thus auditory feedback appears to mitigate some of the risk associated with menu selection while driving. Overall, the results indicated that not only should earPod menuing be able to provide safer interaction in dual task settings, but also that, with sufficient training, audio only menu selection using innovative techniques such as those employed by earPod can be competitive with visual menuing systems even in desktop settings.
Nontradable Market Index and Its Derivatives
Keywords: Nontradable Market Index and Its Derivatives

The S&P 500 Index is a leading indicator of U.S. equities and is meant to reflect the risk and return on the U.S. stock market. Many derivatives based on the S&P 500 are available to investors. The S&P 500 Futures of the Chicago Mercantile Exchange and the S&P 500 Index Options of the Chicago Board Options Exchange are both actively traded. My thesis argues that the S&P 500 Index is only a summary statistic designed to reflect the evolution of the stock market. It is not the value of a self-financed tradable portfolio, and its modifications do not coincide with changes of the value of any mimicking portfolio, due to the particular way the S&P 500 Index is computed and maintained. Therefore, the Spot-Futures Parity and the Put-Call Parity do not hold for the S&P 500 Index and its derivatives. Furthermore, its derivatives cannot be priced by using the standard option pricing models, which assume that the underlying asset is tradable. Chapter One analyzes why the S&P 500 Index does not represent the value of a self-financed tradable portfolio and why it cannot be replaced by the value of a tracker such as the SPDR. In particular, we show that the nonlinear and extreme risk dynamics of the SPDR and of the S&P 500 Index are very different. Chapter Two provides empirical evidence that the non-tradability of the S&P 500 Index can explain the Put-Call Parity deviations. Even after controlling for the liquidity risk of the options, we find that the Put-Call Parity implied dividends depend significantly on the option strike. In Chapter Three, we develop an affine multi-factor model to price coherently various derivatives such as forwards and futures written on the S&P 500 Index, and European put and call options written on the S&P 500 Index and on the S&P 500 futures. We consider the cases when the underlying asset is self-financed and tradable and when it is not, and show the difference between them. When the underlying asset is self-financed and tradable, an additional arbitrage condition has to be introduced and implies additional parameter restrictions.
A Biophysical Characterization of Phagolysosome Acidification
Keywords: Lysosome
Phagosome
pH
Microscopy
Macrophage
CFTR

Specialized cells of the innate immune system, such as macrophages, employ lysosomal enzymes, together with cationic peptides and reactive oxygen intermediates, to eliminate invading microorganisms ensnared within phagosomes. The effectiveness of this impressive armamentarium is potentiated by the acid pH generated by the vacuolar-type ATPase (V-ATPase). The determinants of the luminal pH of phagosomes and of the lysosomes they fuse with are not completely understood, but the V-ATPase is known to be electrogenic and net accumulation of protons requires charge compensation. For this reason, counter-ion pathways are thought to serve a central role in the control of acidification. It has generally been assumed that a parallel anion influx accompanies proton pumping to dissipate the voltage that tends to build up. In fact, impaired chloride channel activity in cystic fibrosis has been proposed to underlie the defective phagolysosome acidification and microbial killing reported in lung macrophages. In the first part of this thesis, I devised methods to dialyze the lumen of lysosomes in intact cells, while monitoring lysosomal pH, in order to assess the individual contribution of counter-ions to acidification. Surprisingly, anions were found to be completely dispensable for proton pumping, whereas the presence of permeant cations in the lysosomal lumen was essential. Accordingly, defects in lysosomal anion permeability cannot explain the impaired microbicidal capacity of phagocytes in cystic fibrosis. Even though counter-ion permeation pathways exist, dissipation of the electrical contribution of the V-ATPase may not be complete. If present, a transmembrane potential would alter the rate and extent of proton accumulation in phagosomes and lysosomes. However, no estimates of the voltage across the phagosomes were available. To overcome this deficiency, in the second part of this thesis, I describe a noninvasive procedure to estimate the voltage across the phagosome using fluorescence resonance energy transfer. This novel approach, in combination with organellar pH measurements, demonstrated that proton pumping is not limited by counter-ion permeability.
VLSI Implementation of Digital Signal Processing Algorithms for MIMO/SISO Systems
Keywords: ASIC Implementation
K-Best MIMO Detector
Sequential Monte Carlo
Lattice Reduction

The efficient high-throughput VLSI implementation of near-optimal multiple-input multiple-output (MIMO) detectors for 4x4 MIMO systems in high-order quadrature amplitude modulation (QAM) schemes has been a major challenge in the literature. To address this challenge, this thesis introduces a novel scalable pipelined VLSI architecture for a 4x4 64-QAM MIMO receiver based on K-Best lattice decoders. The key contribution is a means of expanding/visiting the intermediate nodes of the search tree on-demand, rather than exhaustively along with three types of distributed sorters operating in a pipelined structure. The combined expansion and sorting cores are able to find the K best candidates in K clock cycles. The proposed architecture has a fixed critical path independent of the constellation order, on-demand expansion scheme, efficient distributed sorters, and is scalable to a higher number of antennas/constellation orders. Fabricated in 0.13um CMOS, it operates at a significantly higher throughput (5.8x better) than currently reported schemes and occupies 0.95 mm2 core area. Operating at 282 MHz clock frequency, it dissipates 135 mW at 1.3 V supply with no performance loss. It achieves an SNR-independent decoding throughput of 675 Mbps satisfying the requirements of IEEE 802.16m and Long Term Evolution (LTE) systems. The measurements confirm that this design consumes 3.0x less energy/bit compared to the previous best design.
Beyond Chronic Rejection: Tissue Remodelling in Obliterative Bronchiolitis after Lung Transplantation
Keywords: Lung transplantation
chronic rejection

The long-term success of lung transplantation has been challenged by chronic graft dysfunction, which is manifested as obliterative bronchiolitis (OB). We demonstrated that allograft airway fibrosis is a dynamic process of tissue remodelling, in which cellular and matrix components dynamically change before or after complete obliteration of the airway lumen. This dynamic process was associated with changes in expression and activity of matrix metalloproteinases (MMPs). The early inflammatory phase was associated with MMP-dependent migration of blood-borne fibrocytes, which highly express MMP-9 and MMP-12. ‘Established’ fibrosis was associated with MMP-2 and MMP-14 expressed by myofibroblasts in both human OB lesions and their animal models. In established allograft airway fibrosis, general MMP inhibition resulted in apoptosis of myofibroblasts in vivo and in vitro, while low-doses of MMP-inhibitor treatment induced upregulation of MMP-2, increased collagenolytic activity, and significantly decreased myofibroblasts and collagen. The dynamic process of tissue remodelling in established allograft airway fibrosis was supported by underlying continuous alloimmune responses, in particular, direct T-cell-myofibroblast contact. iii Modulation of tissue remodelling using a low-dose MMP inhibitor in combination with cyclosporine induced partial regression of fibrosis after its establishment. We further demonstrated the mechanism of alloimmune responses unique to the lung. Human and animal studies demonstrated that bronchioles develop de novo lymphoid tissue characterized by formation of high endothelial venules and homing of effector memory T-cells. A following study demonstrated the important role of local immunological memory maintained by the intrapulmonary lymphoid tissue in exerting effector function in allograft rejection. Collectively, the present studies support the hypothesis that tissue remodelling is an important mechanism of allograft airway fibrosis. Regulation of tissue remodelling and underlying tissue injury is important not only to arrest aberrant remodelling of allograft airways but likely to reverse aberrant remodelling and to regenerate normal tissue architecture in airways after lung transplantation.
Opportunities of Contact: Derrida and Deleuze/Guattari on Translation
Keywords: translation

This work engages with three contemporary thinkers who offer directions for a philosophy of translation. The initial thesis is that translation is a privileged mode of examining difference in language, because it indicates both the necessity to bring what is irreducibly other or foreign into terms of familiarity, and the extreme difficulties, perhaps the impossibility, of such an enterprise. I examine the particular responses to this translation dilemma given by Jacques Derrida and Gilles Deleuze/Félix Guattari, ultimately arguing that although Derrida gives crucial insights into the problem itself, a future theory of translation would need to go beyond Derrida’s approach and adopt the radically pragmatic approach to language articulated by Deleuze and Guattari. Throughout, I examine this problem in terms of the distinction between Derrida as a philosopher of transcendence and Deleuze and Guattari as philosophers of immanence. Derrida’s work insists on the impossibility of representing the other in language, and his simultaneous necessity and impossibility of translation is valuable insofar as it offers resistances to the presumptions of translation as standing in for the other. I argue, however, that Derrida’s insistence on impossibility as marked in the performativity of language itself is ultimately unable to give us a satisfying account of the relation between language and the world, which leaves us with no direction for how we might engage with concrete problems in actual translation situations in a productive way. The central problem with Derrida’s view is his insistence on the model of inter-lingual translation as figuring the paradox of difference in language. The approach of Deleuze and Guattari reverses this order and re-conceives of translation in a pragmatic context, where inter-semiotic translations are uniquely able to release the creative power of language. Through their articulation of the expressivity of matter, Deleuze and Guattari place language in a wider context in which it is intricately engaged in a world. I place translation in this wider context in order to demonstrate how Deleuze and Guattari’s thinking about language allows us to re-conceive of translation practices as opportunities for transformations of both language and world.
Power of Non-uniformity in Proof Complexity
Keywords: proof complexity
computational complexity

As the title indicates, this thesis is concerned with the strength of non-uniformity in proof complexity. The non-uniform part is there because we look at quantified propositional proof systems. With these proof systems we are interested in the minimum size of proofs that prove a family of tautologies. Like circuits, these proofs are not necessarily easy to construct. We measure the strength of a proof system by characterizing which families of tautologies have polynomial-size proofs in the proof system. The proof systems we examine were first introduced by Krajícek and Pudlák [23], but have only received limited attention since then. These systems are called Gi and [special characters omitted]. Gi is the propositional version of Gentzen's LK with cut formulas restricted to formulas with i − 1 quantifier alternations, and [special characters omitted] is the treelike version of Gi. We look at the strength of these proof systems in three ways. The first is to compare them with bounded arithmetic. We find the weakest theory that can prove that a given proof system is sound. The second method is to compare proof systems with respect to computational complexity. We determine the complexity of finding a witness for the outermost existential quantifiers of a formula given a proof of that formula. The final method is to compare the proof systems to each other. This is done using the notion of p-simulations. An important tool in all of this work is an adaptation of the Herbrand theorem for the propositional setting. Most proof-theoretic proofs of the Herbrand theorem require cut-elimination which causes the size of the proof to increase exponentially. We adapt the statement of the theorem and the proof to avoid this increase. We finish by defining new proof systems that meet given requirements. The goal is to determine where proof systems get their strength. In all cases, it comes down to the eigenvariables. The strength of a proof system that allows quantifiers in the cut formulas is determined by the difficulty of witnessing the eigenvariables.
A Game Theoretical Approach to Constrained OSNR Optimization Problems in Optical Networks
Keywords: Game theory
Constrained optimization
Optical Networks

Optical signal-to-noise ratio (OSNR) is considered as the dominant performance parameter at the physical layer in optical networks. This thesis is interested in control and optimization of channel OSNR by using optimization and game-theoretic approaches, incorporating two physical constraints: the link capacity constraint and the channel OSNR target. To start, we study OSNR optimization problems with link capacity constraints in single point-to-point fiber links via two approaches. We first present a framework of a Nash game between channels towards optimizing individual channel OSNR. The link capacity constraint is imposed as a penalty term to each cost function. The selfish behavior in a Nash game degrades the system performance and leads to the inefficiency of Nash equilibria. From the system point of view, we formulate a system optimization problem with the objectives of achieving an OSNR target for each channel while satisfying the link capacity constraint. As an alternative to study the efficiency of Nash equilibria, we use the system framework to investigate the effects of parameters in cost functions in the game-theoretic framework. Then extensions to multi-link and mesh topologies are carried out. We propose a partition approach by using the flexibility of channel power adjustment at optical switches. The multi-link structure is partitioned into stages with each stage being a single sink. By fully using the flexibility, a more natural partition approach is applied to mesh topologies where each stage is a single link. The closed loop in mesh topologies can be unfolded by selecting a starting link. Thus instead of maximization of channel OSNR from end to end, we consider minimization of channel OSNR degradation between stages. We formulate a partitioned Nash game which is composed of ladder-nested stage Nash games. Distributed algorithms towards the computation of a Nash equilibrium solution are developed for all different game frameworks. Simulations and experimental implementations provide results to validate the applicability of theoretical results.
Theory of Ultrafast Electron Diffraction
Keywords: Ultrafast physics
electron diffraction
electron propagation

Ultrafast electron diffraction (UED) is a method of directly imaging system dynamics at the atomic scale with picosecond time resolution. In this thesis I present theoretical analyses of the experimental processes, and construct models in order to better understand UED experiments and to guide future refinements. In particular, I derive a model of electron bunch propagation and a model of electron bunch diffraction, where both models take into account all bunch parameters. To analyse the propagation of electron bunches, I present a mean-field analytic Gaussian (AG) model. I derive a system of ordinary differential equations that are solved quickly and easily to give the bunch dynamics. The AG model is compared to N -body numerical simulations of initially Gaussian bunches, and I demonstrate excellent agreement between the two result sets. I also present a comparison of the AG model with numerical simulations of quasi-Gaussian and non-Gaussian distributions, extending the applicability of the AG model to the propagation of ``real-world'' bunches. During propagation, electron bunches can be shaped by electron-optic devices, which are necessary to attain high brightness, sub-100 fs bunches. I investigate two types of electron-optic devices: one is a magnetic lens used for collimating or focusing bunches, the other is a bunch compressor. I derive bunch parameter transformations for each of the electron-optic devices, and present numerical calculations using these transformations along with the AG model showing the effects of the devices on the evolution of the bunch parameters. To analyse electron bunch diffraction in UED experiments, I present a general scattering formalism. Using single-scattering and far-field approximations, I derive an expression for the diffracted signal that depends on the electron bunch properties just before scattering. Using this expression I identify the transverse and longitudinal coherence lengths and discuss the importance of these length scales in diffraction pattern formation. I also discuss the effects of different bunch parameters on the measured diffracted flux, and present sample numerical calculations for scattering by nanosize particles based on this model. This simulation demonstrates the cumulative effects of the bunch parameters, and shows the complex interplay of the bunch and target properties on the diffracted signal.
Contrast and Similarity in Consonant Harmony Processes
Keywords: phonology
similarity
contrast
consonant harmony

This thesis deals with the nature and definition of phonological similarity and shows that, when similarity plays a role in the motivation of phonological processes, it is evaluated over abstract, phonological features and not purely phonetic properties. Empirical evidence for this position is drawn from the domain of consonant harmony. Typological studies of consonant harmony (Hansson 2001, Rose and Walker 2004) have argued that segments which interact in consonant harmony processes must be highly similar to one another. This thesis provides analyses of a range of consonant harmony processes and demonstrates that, in each case, the notion of similarity needed in order to determine participating segments is evaluated over contrastive feature specifications. Contrastive specifications are established according to language-specific feature hierarchies (Jackobson and Halle 1956, Dresher 2003, forthcoming) with some features taking scope over others. Languages analyzed in some detail include Bumo Izon, Kalabari Ijo, Hausa, Dholuo, Anywa, Tzutujil and Aymara. Two definitions of similarity are proposed in order to account for two sets of cases. In one set of consonant harmony processes, interacting segments are similar in the sense that they constitute the natural class of segments contrastively specified in the harmonic feature. In another set of cases, participating segments must be similar according to the following definition; they must differ in only a single marked and contrastive feature specification.