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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Creole Genesis and Universality: Case, Word Order, and Agreement

Snow, Gerald Taylor 01 March 2017 (has links)
The genesis of creole languages is important to the field of linguistics for at least two reasons. As newly emerging languages, creoles provide a unique window on the human language faculty and on the development of language generally (Veenstra 2008). They also offer insight into what are arguably universal linguistic structures. Two opposing theories have been in contention in the literature with respect to creole genesis: (1) that creoles owe their origin to the lexifier and substrate languages of their speech community and to other environmental influences (McWhorter 1997); and alternatively, (2) that universal innate linguistic structures or principles are the generative source of creole grammar (Bickerton 1981). Both theories have a claim to at least partial correctness. This thesis adds new evidence in support of the universalist/innatist argument. This thesis examines five written creole languages and two signed creole languages of geographic and historical diversity and focuses on the grammatical system of case, word order, and agreement of these languages as one axis along which to investigate the issue of creole genesis and universality. The signed languages in particular offer unique data, especially the data from Nicaraguan Sign Language, where there was an absence of significant lexifier and substrate influences. Patterns of what are termed core indispensable features in these seven language systems are uncovered, examined and compared. Further comparison is made with the case, word order, and agreement features of the world's languages generally and of creole languages as a subset of the world's languages, based on data in the World Atlas of Language Structures (Dryer & Haspelmath 2009) and in the Atlas of Pidgin and Creole Language Structures (Michaelis et al. 2013b), respectively. The findings and contributions to the field made possible from the data in this thesis are that there are commonalities in the case, word order, and agreement systems of the subject creole languages that qualify as core indispensable features and that these features are generated by universal innate linguistic expectations. These commonalities are: (1) that morphological case inflection is not a core indispensable feature; (2) that SVO word order is a core indispensable feature; and (3) that agreement as a feature, seen only when word order is apparently verb final, occurs only in the signed creole languages and is more accurately interpreted as topicalization incorporated into SVO word order rather than as an independent core feature. Nicaraguan Sign Language presents especially compelling evidence for these conclusions.
22

Design and Discrete Optimization of BIBO Stable FRM Digital Filters Incorporating IIR Digital Interpolation Subfilters

Bokhari, Syed 06 1900 (has links)
Digital filters having sharp transition band play a vital role in modern digital signal processing (DSP) applications. Emerging technologies require digital filters to be both computationally efficient in software/hardware realizations. This thesis is concerned with the design and structural-level optimization of sharp transition band digital filters employing the well known frequency response masking (FRM) approach. Unlike the conventional finite impulse response (FIR) based FRM approach, the FRM technique used in this thesis incorporates infinite impulse response (IIR) digital interpolation subfilters, thereby reducing the overall filter order that results in a reduction of hardware complexity. Two realization methods are discussed in this thesis, namely, the bilinear-lossless-discrete-integrators (bilinear-LDI) digital filter design technique, and the lattice wave digital filter (lattice WDF) digital filter design technique. Diversity controlled (DC) genetic algorithm (GA) is employed to optimize both types of IIR based FRM digital filters over the efficient canonical signed digit (CSD) multiplier coefficient space. DCGAs represent FRM digital filters by a binary chromosome and proceed from a population pool of candidate chromosomes to future generations in order to arrive at the desired FRM digital filter satisfying the design specifications. A novel cost-function is used that allows the DCGA to simultaneously optimize both the amplitude-frequency and group-delay frequency response. A fast convergence speed has been observed. / Communications
23

Quasisymmetric Functions and Permutation Statistics for Coxeter Groups and Wreath Product Groups

Hyatt, Matthew 22 July 2011 (has links)
Eulerian quasisymmetric functions were introduced by Shareshian and Wachs in order to obtain a q-analog of Euler's exponential generating function formula for the Eulerian polynomials. They are defined via the symmetric group, and applying the stable and nonstable principal specializations yields formulas for joint distributions of permutation statistics. We consider the wreath product of the cyclic group with the symmetric group, also known as the group of colored permutations. We use this group to introduce colored Eulerian quasisymmetric functions, which are a generalization of Eulerian quasisymmetric functions. We derive a formula for the generating function of these colored Eulerian quasisymmetric functions, which reduces to a formula of Shareshian and Wachs for the Eulerian quasisymmetric functions. We show that applying the stable and nonstable principal specializations yields formulas for joint distributions of colored permutation statistics. The family of colored permutation groups includes the family of symmetric groups and the family of hyperoctahedral groups, also called the type A Coxeter groups and type B Coxeter groups, respectively. By specializing our formulas to these cases, they reduce to the Shareshian-Wachs q-analog of Euler's formula, formulas of Foata and Han, and a new generalization of a formula of Chow and Gessel.
24

Design of a Low Power Cyclic/Algorithmic Analog-to-Digital Converter in a 130nm CMOS Process

Puppala, Ajith kumar January 2012 (has links)
Analog-to-digital converters are inevitable in the modern communication systems and there is always a need for the design of low-power converters. There are different A/D architectures to achieve medium resolution at medium speeds and among all those Cyclic/Algorithmic structure stands out due to its low hardware complexity and less die area costs. This thesis aims at discussing the ongoing trend in Cyclic/Algorithmic ADCs and their functionality. Some design techniques are studied on how to implement low power high resolution A/D converters. Also, non-ideal effects of SC implementation for Cyclic A/D converters are explored. Two kinds of Cyclic A/D architectures are compared. One is the conventional Cyclic ADC with RSD technique and the other is Cyclic ADC with Correlated Level Shift (CLS) technique. This ADC is a part of IMST Design + Systems International GmbH project work and was designed and simulated at IMST GmbH. This thesis presents the design of a 12-bit, 1 Msps, Cyclic/Algorithmic Analog-to-Digital Converter (ADC) using the “Redundant Signed Digit (RSD)” algorithm or 1.5-bit/stage architecture with switched-capacitor (SC) implementation. The design was carried out in 130nm CMOS process with a 1.5 V power supply. This ADC dissipates a power of 1.6  mW when run at full speed and works for full-scale input dynamic range. The op-amp used in the Cyclic ADC is a two-stage folded cascode structure with Class A output stage. This op-amp in typical corner dissipates 631 uW power at 1.5 V power supply and achieves a gain of 77 dB with a phase margin of 64° and a GBW of 54 MHz at 2 pF load.
25

Key Randomization Countermeasures to Power Analysis Attacks on Elliptic Curve Cryptosystems

Ebeid, Nevine Maurice 04 1900 (has links)
It is essential to secure the implementation of cryptosystems in embedded devices agains side-channel attacks. Namely, in order to resist differential (DPA) attacks, randomization techniques should be employed to decorrelate the data processed by the device from secret key parts resulting in the value of this data. Among the countermeasures that appeared in the literature were those that resulted in a random representation of the key known as the binary signed digit representation (BSD). We have discovered some interesting properties related to the number of possible BSD representations for an integer and we have proposed a different randomization algorithm. We have also carried our study to the $\tau$-adic representation of integers which is employed in elliptic curve cryptosystems (ECCs) using Koblitz curves. We have then dealt with another randomization countermeasure which is based on randomly splitting the key. We have investigated the secure employment of this countermeasure in the context of ECCs.
26

Key Randomization Countermeasures to Power Analysis Attacks on Elliptic Curve Cryptosystems

Ebeid, Nevine Maurice 04 1900 (has links)
It is essential to secure the implementation of cryptosystems in embedded devices agains side-channel attacks. Namely, in order to resist differential (DPA) attacks, randomization techniques should be employed to decorrelate the data processed by the device from secret key parts resulting in the value of this data. Among the countermeasures that appeared in the literature were those that resulted in a random representation of the key known as the binary signed digit representation (BSD). We have discovered some interesting properties related to the number of possible BSD representations for an integer and we have proposed a different randomization algorithm. We have also carried our study to the $\tau$-adic representation of integers which is employed in elliptic curve cryptosystems (ECCs) using Koblitz curves. We have then dealt with another randomization countermeasure which is based on randomly splitting the key. We have investigated the secure employment of this countermeasure in the context of ECCs.
27

Statistical model building and inference about the normalized site attenuation (NSA) measurements for electromagnetic interference (EMI)

Chiu, Shih-ting 09 August 2004 (has links)
Open site measurement on the electromagnetic interference is the most direct and universally accepted standard approach for measuring radiated emissions from an equipment or the radiation susceptibility of a component or equipment. A site is qualified for testing EMI or not is decided by the antenna measurements. In this work, we use data from setups with di erent factors to find relations of measurement and the situation of antenna. A one change point model has been used to fit observed measurements and compare the di erences with two kinds of antenna (broadband antenna and dipole antenna). However, with only one change point model it may not give a suitable fit for all data sets in this work. Therefore, we have tried other models and applied them to the data. Furthermore, we try to set up another standard more strict than ¡Ó4dB based on statistical inference results in deciding whether a site is a better one with more precision in measuring EMI values. Finally, a program by Matlab with a complete analysis based on the procedure performed here is provided, so that it may be used as a standard tool for evaluating whether a site is with good measurement quality in practice.
28

Toward More Composable Software-Security Policies: Tools and Techniques

Lomsak, Daniel 01 January 2013 (has links)
Complex software-security policies are dicult to specify, understand, and update. The same is true for complex software in general, but while many tools and techniques exist for decomposing complex general software into simpler reusable modules (packages, classes, functions, aspects, etc.), few tools exist for decomposing complex security policies into simpler reusable modules. The tools that do exist for modularizing policies either encapsulate entire policies as atomic modules that cannot be decomposed or allow ne-grained policy modularization but require expertise to use correctly. This dissertation presents a policy-composition tool called PoliSeer [27, 26] and the PoCo policy-composition software-security language. PoliSeer is a GUI-based tool designed to enable users who are not expert policy engineers to exibly specify, visualize, modify, and enforce complex runtime policies on untrusted software. PoliSeer users rely on expert policy engineers to specify universally composable policy modules; PoliSeer users then build complex policies by composing those expert-written modules. This dissertation describes the design and implementation of PoliSeer and a case study in which we have used PoliSeer to specify and enforce a policy on PoliSeer itself. PoCo is a language for specifying composable software-security policies. PoCo users specify software-security policies in terms of abstract input-output event sequences. The policy outputs are expressive, capable of describing all desired, irrelevant, and prohibited events at once. These descriptive outputs compose well: operations for combining them satisfy a large number of algebraic properties, which allows policy hierarchies to be designed more simply and naturally. We demonstrate PoCo's capability via a case study in which a sophisticated policy is implemented in PoCo.
29

Design and Discrete Optimization of BIBO Stable FRM Digital Filters Incorporating IIR Digital Interpolation Subfilters

Bokhari, Syed Unknown Date
No description available.
30

Animação de humanos virtuais aplicada para língua brasileira de sinais / Virtual human animation applied in brazilian sign language

Schneider, Andréia Rodrigues de Assunção January 2008 (has links)
Os surdos possuem a capacidade de utilizar a língua oral para se comunicar limitada e por isso tem como língua materna as línguas gestuais. Isso dificulta a utilização, de maneira satisfatória, dos serviços básicos, bem como a inserção na sociedade ouvinte, que é composta pela maioria da população. Devido ao fato desta língua ser gestual, é viável afirmar que se pode simular seus sinais através de animação de humanos virtuais, sem perder a percepção correta do significado do mesmo (que palavra o sinal representa). O presente trabalho descreve uma técnica de animação aplicada em LIBRAS. A idéia principal é, baseado na descrição da animação de um determinado sinal, executar seu movimento de forma mais, ou menos ampla para que se consiga aproveitar o espaço disponível para a gesticulação, sem entretanto perder o significado do sinal. A animação computacional de um sinal deve o mais próximo possível do real, ou seja, seu significado deve ser facilmente entendido e sua execução deve ser natural (suave e contínua). Para isso os sinais devem ser definidos de acordo com as limitações de movimentação das articulações humanas, bem como ao campo de visão do receptor. Além disso alguns parâmetros devem ser analisados e definidos: velocidade do movimento, tempo e amplitude dos sinais. Outro aspecto importante a ser tratado é o espaço que é disponível para a execução do sinal: dependendo do espaço, o sinal deve ser animado de forma a se adequar a ele. A implementação da técnica resultou em um sistema de animação para LIBRAS composto por três módulos: • um modelador do humano virtual, de forma que as articulações e DOFs deste sejam anatomicamente coerentes com a realidade; • um gerador de gestos, o qual é responsável pela transformação dos parâmetros como velocidade, tempo de execução do gesto, configuração das juntas, em um arquivo que descreve a animação da pose. Cabe ressaltar que as palavras em LIBRAS são conhecidas como sinais. Já um sinal é composto por um ou vários gestos e estes são compostos por poses; • um animador, o qual é responsável por gerar a animação de um sinal previamente criado, adequando (se necessário) a amplitude deste sinal ao espaço disponível para a execução do mesmo. O sistema criado foi submetido a testes para que a técnica fosse validada. O que se buscou com os testes foi verificar se os sinais gerados eram passíveis de entendimento, ou seja, se a animação gerada representava determinada palavra. Todos os aspectos acima mencionados são apresentados e analisados em detalhes. / Deaf people have a limited capacity of using oral language to communicate. Because of this, they use gestural languages as their native language. This makes it especially difficult for them to make use of basic services in a satisfactory way and to properly integrate the hearing world, to which the majority of the population belongs. Due to the fact that this language is only gestural, it is possible to say that the signs it comprises of can be simulated with the animation of virtual humans without losing the correct perception of their inherent meanings (what words they represent). This work describes a technique of animation for LIBRAS. The main idea is to take the movement of a sign from a description of its animation and execute it in a more or less wide manner in order to better use the available space for gesticulation without losing the meaning. The computer animation of a sign must be as close to the real gesture as possible. Its meaning must be easily understood and its execution must be natural (smooth and continuous). For that, the signs must be defined in accordance with the movement limitations imposed by the human joints, and the field of view of the receiver. Besides that, some relevant parameters must be analyzed and defined: speed of the movement, time and amplitude of the signs. Another important aspect to be addressed is the space that is available for the execution of the sign: depending on the area, the sign must be animated in a manner that makes it properly fit in it. The implementation of the technique resulted in a animation system for LIBRAS, that consists of three modules: • a virtual human modeler, so that the joints and DOFs are anatomically consistent with reality; • a gesture generator, which is responsible for the processing of parameters such as speed, time of execution of the gesture, joint configuration, in a file that describes the animation of the pose. It is worth emphasizing that the words in LIBRAS are known as signs. Already a sign is composed of one or more gestures and they are composed of poses; • an animator, which is responsible for generating the animation of a previously created sign, fitting (if necessary) the sign amplitude to the space available for its animation. The generated system has been submitted for tests in order to validate the technique. The goal of the tests was to check whether the generated signs were understandable - if the generated animation represented a certain word. All aspects above are presented and analyzed in detail.

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