Polydimethylsiloxane(PDMS) thin films have the advantages of flexible , good chemicophysical properties , low energetic surface that supports the vertical anchoring of liquid crystal molecules , could be fabricated easily by Replica Molding Method , low cost and good optically transparent. We study of the use of PDMS in flexible liquid crystal displays and the Electro-Optical properties of LC flexible cell. In experiment we use PDMS to fabricate vertical alignment layer , elastomer substrate and spacer to maintain the Electro-Optical properties in flexible displays.

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Because horses are animals of flight, bone fractures in the horses' limbs are quite common. When foals fracture a bone in their leg, the healthy leg is often compromised. During convalescence, the animal tends to overstress the healthy leg in an attempt to relieve the stress on the injured leg. This results in angular limb deformities, lax tendons, laminitis, and similar problems. These problems could possibly be avoided through a load-bearing device that would relieve the additional weight from the foal's limbs. In order to allow for in-vitro testing of such a load-bearing device, this thesis describes the design, analysis, and procedure of construction of a robotic replica of a foal's limb. In particular, the robotic replica has been designed to replicate all of the anticipated motion of a foal's limb, including walking, shifting weight from one leg to the other, and kicking, for example, using gait-analysis data from an actual horse's gait. From such data, the robotic replica has been designed in IDEAS and analyzed using multibody dynamics simulations code and the finite-element-analysis software ANSYS. To evaluate the function of the robotic replica, a control system was developed to reproduce observed gait characteristics. Comparison of the computer-simulated gait with the observed gait showed that a linear feedback control algorithm resulted in a response adequate for the proposed function. The proposed robotic replica has the potential for aiding in the development of several other bioassistive devices. With minor modifications, the robotic replica could be used to test a device design to transfer load from the cannon bone to the ground for an animal inflicted with laminitis (founder). These possibilities should be investigated in the future. / Master of Science

Data Grids provide services and infrastructure for distributed data-intensive applications accessing massive geographically distributed datasets. An important technique to speed access in Data Grids is replication, which provides nearby data access. Although data replication is one of the major techniques for promoting high data access, the problem of replica placement has not been widely studied for large-scale Grid environments. In this thesis, I propose improved data placement techniques useful when replicating potentially large data files in wide area data grids. These techniques are aimed at achieving faster data access as well as efficient utilization of bandwidth and storage resources. At the core of my approach is a new highly distributed replica placement algorithm that places data in strategic locations to improve overall data access performance while satisfying varying user/application and system demands. This improved efficiency of access to large data will improve the practicality of large-scale data and compute intensive collaborative scientific endeavors. My thesis makes several contributions towards improving the state-of-the-art for replica placement in large-scale data grid environments. The major contributions are: (i) development of a new popularity-driven dynamic replica placement algorithm for hierarchically structured data grids that balance storage space utilisation and access latency; (ii) creation of an adaptive version of the base algorithm to dynamically adapt the frequency and degree of replication based on such factors as data request arrival rates, available storage capacities, etc.; (iii) development of a new highly distributed algorithm to determine a near-optimal replica placement while minimizing replication cost (access and update) for a given traffic pattern; (iv) creation of a distributed QoS-aware replica placement algorithm that supports multiple quality requirements both from user and system perspectives to support efficient transfers of large replicas. Simulation results using widely observed data access patterns demonstrate how the effectiveness of my replica placement techniques is affected by various factors such as grid network characteristics (i.e. topology, number of nodes, storage and workload capacities of replica servers, link capacities, traffic pattern), QoS requirements, and so on. Finally, I compare the performance of my algorithms to a number of relevant algorithms from the literature and demonstrate their usefulness and superiority for conditions of interest.

Data Grids provide services and infrastructure for distributed data-intensive applications accessing massive geographically distributed datasets. An important technique to speed access in Data Grids is replication, which provides nearby data access. Although data replication is one of the major techniques for promoting high data access, the problem of replica placement has not been widely studied for large-scale Grid environments. In this thesis, I propose improved data placement techniques useful when replicating potentially large data files in wide area data grids. These techniques are aimed at achieving faster data access as well as efficient utilization of bandwidth and storage resources. At the core of my approach is a new highly distributed replica placement algorithm that places data in strategic locations to improve overall data access performance while satisfying varying user/application and system demands. This improved efficiency of access to large data will improve the practicality of large-scale data and compute intensive collaborative scientific endeavors. My thesis makes several contributions towards improving the state-of-the-art for replica placement in large-scale data grid environments. The major contributions are: (i) development of a new popularity-driven dynamic replica placement algorithm for hierarchically structured data grids that balance storage space utilisation and access latency; (ii) creation of an adaptive version of the base algorithm to dynamically adapt the frequency and degree of replication based on such factors as data request arrival rates, available storage capacities, etc.; (iii) development of a new highly distributed algorithm to determine a near-optimal replica placement while minimizing replication cost (access and update) for a given traffic pattern; (iv) creation of a distributed QoS-aware replica placement algorithm that supports multiple quality requirements both from user and system perspectives to support efficient transfers of large replicas. Simulation results using widely observed data access patterns demonstrate how the effectiveness of my replica placement techniques is affected by various factors such as grid network characteristics (i.e. topology, number of nodes, storage and workload capacities of replica servers, link capacities, traffic pattern), QoS requirements, and so on. Finally, I compare the performance of my algorithms to a number of relevant algorithms from the literature and demonstrate their usefulness and superiority for conditions of interest.

REPLICA is a family of novel scalable chip multiprocessors with configurable emulated shared memory architecture, whose computation model is based on the PRAM (Parallel Random Access Machine) model. The purpose of this thesis is to, by benchmarking different types of computation problems on REPLICA, similar parallel architectures (SB-PRAM and XMT) and more diverse ones (Xeon X5660 and Tesla M2050), evaluate how REPLICA is positioned among other existing architectures, both in performance and programming effort. But it should also examine if REPLICA is more suited for any special kinds of computational problems. By using some of the well known Berkeley dwarfs, and input from unbiased sources, such as The University of Florida Sparse Matrix Collection and Rodinia benchmark suite, we have made sure that the benchmarks measure relevant computation problems. We show that today’s parallel architectures have some performance issues for applications with irregular memory access patterns, which the REPLICA architecture can solve. For example, REPLICA only need to be clocked with a few MHz to match both Xeon X5660 and Tesla M2050 for the irregular memory access benchmark breadth first search. By comparing the efficiency of REPLICA to a CPU (Xeon X5660), we show that it is easier to program REPLICA efficiently than today’s multiprocessors. / REPLICA är en grupp av konfigurerbara multiprocessorer som med hjälp utav ett emulerat delat minne realiserar PRAM modellen. Syftet med denna avhandling är att genom benchmarking av olika beräkningsproblem på REPLICA, liknande (SB-PRAM och XMT) och mindre lika (Xeon X5660 och Tesla M2050) parallella arkitekturer, utvärdera hur REPLICA står sig mot andra befintliga arkitekturer. Både prestandamässigt och hur enkel arkitekturen är att programmera effektiv, men även försöka ta reda på om REPLICA är speciellt lämpad för några särskilda typer av beräkningsproblem. Genom att använda välkända Berkeley dwarfs applikationer och opartisk indata från bland annat The University of Florida Sparse Matrix Collection och Rodinia benchmark suite, säkerställer vi att det är relevanta beräkningsproblem som utförs och mäts. Vi visar att dagens parallella arkitekturer har problem med prestandan för applikationer med oregelbundna minnesaccessmönster, vilken REPLICA arkitekturen kan vara en lösning på. Till exempel, så behöver REPLICA endast vara klockad med några få MHz för att matcha både Xeon X5660 och Tesla M2050 för algoritmen breadth first search, vilken lider av just oregelbunden minnesåtkomst. Genom att jämföra effektiviteten för REPLICA gentemot en CPU (Xeon X5660), visar vi att det är lättare att programmera REPLICA effektivt än dagens multiprocessorer.

The goal of the graduation thesis is building of a working replica of the motorcycle engine Laurin&Klement, type TB from 1902. The thesis focuses on the manufacturing of cast parts. The piece production of the engine has been based on extant original pieces, missing pieces have been manufactured according to period photographs and leaflets. This method can be applied for production of missing or damaged pieces of historical motorcycles‘ engines.

Nesta tese utilizamos o modelo do replicador aleatório, proposto por Diederich e Opper, para analisar as propriedades de equilíbrio de ecossistemas complexos (formados por um grande número de espécies) em três situações distintas. Na primeira parte desta tese, investigamos os efeitos de interações variáveis sobre a estrutura do ecossistema, utilizando o método de réplicas generalizado, introduzido por Penney et al. Este formalismo propõe uma nova interpretação para o índice de réplicas n, a saber, como sendo a razão entre duas temperaturas características: a temperatura relacionada aos acoplamento e a temperatura associada às variáveis de spin. Empregando t\\\'ecnicas de campo m\\\'edio de Mec\\^anica Estat\\\'stica e tamb\\\'em simula\\c\\~oes num\\\'ericas tratamos, em particular, do estado fundamental ($\\beta ightarrow + \\infty$). Encontramos dois regimes distintos, um onde prevalece a coopera\\c\\~ao entre as diferentes esp\\\'ecies ($\\beta^{\\prime} > 0$) e outro no qual a competi\\c\\~ao \\\'e predominante ($\\beta^ < 0$). No primeiro caso temos uma transi\\c\\~ao descont\\\'{\\i}nua para um regime de diversidade nula e no outro temos uma m\\\'axima diversidade das esp\\\'ecies. Na segunda parte desta tese \\cite, estudamos as implica\\c\\~oes de uma temperatura finita sobre a estrutura do ecossistema. Utilizamos a regra de Hebb para descrever as intera\\c\\~oes entre as diferentes esp\\\'ecies. A temperatura surge, no modelo, atrav\\\'es de um ru\\\'do gaussiano introduzido na equa\\c\\~ao estoc\\\'astica que rege a din\\^amica do processo. Tratamos analiticamente o caso recozido ({\\em annealed}), no qual as caracter\\\'sticas das esp\\\'ecies evoluem t\\~ao rapidamente quanto suas concentra\\c\\~oes, e o caso temperado ({\\em quenched}), onde tais caracter\\\'sticas est\\~ao fixas. Conclu\\\'{\\i}mos que h\\\'a uma transi\\c\\~ao de fase descont\\\'{\\i}nua entre um estado onde a competi\\c\\~ao prevalece, determinando baixa diversidade, para outro estado onde predomina a coopera\\c\\~ao. Por fim \\cite, analisamos as poss\\\'veis consequ\\^encias de uma interven\\c\\~ao humana sobre as propriedades de equil\\\'{\\i}brio do ecossistema. Admitimos o princ\\\'pio da exclus\\~ao competitiva para modelar os acoplamentos entre as diferentes esp\\\'ecies, a regra de Hebb. Interferimos na comunidade impondo que um conjunto de caracteres, selecionados previamente, esteja presente em uma fra\\c\\~ao bem definida dos seus membros. O principal resultado deste estudo revela, desde que o par\\^ametro de competi\\c\\~ao entre indiv\\\'duos semelhantes n\\~ao seja muito pequeno, que o efeito de uma tal manipula\\c\\~ao conduz a perda da diversidade e, portanto, ao empobrecimento do ecossistema. / In this thesis we use the random replicator model, proposed by Diederich and Opper \\cite, to analyse the equilibrium properties of complex ecosystems (formed by a large number of species) in three distinct situations. In the first part of this thesis \\cite, we investigate the effects of variable interactions upon ecosystem structure, using the generalized replica method, introduced by Penney et al \\cite. In this formalism we find a new interpretation for the replica number $n$ as the ratio between two characteristic temperatures: the temperature related to the couplings ($\\beta^$) and the temperature associated to the spin variables ($\\beta$). We approach the problem using mean field methods of statistical mechanics and intensive numerical simulations; in particular we are concerned with the ground state ($\\beta ightarrow + \\infty$). We find two distinct regimes, one where cooperation between different species prevails ($\\beta^ > 0$) and the other in which competition is predominant ($\\beta^ < 0$). In the first case we have a discontinuous transition to the zero diversity regime and in the other we have the maximum species diversity. In the second part of this thesis \\cite, we examine the finite temperature implications upon ecosystem structure. Through the Hebb rule we can describe the interactions between different species. With the aid of a Gaussian noise in the stochastic equation, that governs the temporal evolution, we have a way to introduce the finite temperature in the model. We treat analytically the annealed case, in which the species characteristics evolve so fast as its concentrations, as well as the quenched case, in which such characteristics are fixed. We conclude that there is a discontinuous phase transition between a state where competition prevails, implying low diversity, to another state in which cooperation is stronger. At last \\cite, we analyse the possible consequences of human intervention upon the equilibrium properties of the ecosystem. We assume the competitive exclusion principle to model the couplings between different species, the Hebb rule. We interfere in the community by imposing that a set of characters, previously selected, be present in a well defined fraction of its members. The main result of this study reveals, provided that the intraspecies competition parameter is not too weak, that the effect of such a manipulation leads to the impoverishment of the ecosystem.

Mechanical rubbing alignment is the most common used method in the liquid crystal display manufacturing process. However, it may cause dust and electrostatic problem. In this study, we investigate effects of low surface free energy Polydimethylsiloxane (PDMS) on orientation of liquid crystal molecules in a confined structure and fabricate alignment layer using PDMS. In the present study, we show that liquid crystal molecules are arranged in consistency without rubbing process and it may be a new homogeneously aligned mode in liquid crystal display. In this thesis, liquid crystal textures were observed using polarizing optical microscopy (POM). It was found that liquid crystal molecules were homogeneously aligned in PDMS holes. In addition, this thesis indicated that how liquid crystal alignment affected by PDMS layer thickness and surface treatment. We learned that using treatment of JALS-9800 film on the bottom substrate from liquid crystal texture can obtain the arrangement of expected liquid crystal molecules. The liquid crystal device can be produced using PDMS structure. The measurement of electro-optic characteristics showed that the circular shape in the confined structure had better transmittance and contrast ratio.

The unprecedented demand for performance in the latest technologies will ultimately require changes in the way we design cache. Emerging high density embedded memories such as Spin-Transfer Torque Random Access Memory (STTRAM) have emerged as a possible candidate for universal memory due to its high speed, low power, non-volatility, and low cost. Although attractive, STTRAM is susceptible to contactless tampering through malicious exposure to magnetic field with the intention to steal or modify the bitcell content. In this thesis, we explore various attack techniques on STTRAM and then propose a novel array-based sensor to detect the polarity and magnitude of such attacks and then propose two design techniques to mitigate the attack. With our research, we have been able to successfully implement and accurately detect an attack while providing sufficient compensation window (few ns to ~100 us) to enable proactive protection measures. Finally, we show that variable-strength ECC can adapt correction capability to tolerate failures with various strength of an attack.