Post-Silicon validation is playing an increasingly important role as more chips are failing in the functional mode due to either manufacturing defects escaped during scan-based tests or design bugs missed during pre-silicon validation. Critical to the diagnosis engineer is the ability to observe as many relevant internal signal values as possible during debug. To do so, trace buffers have been proposed for enhancing the observability of internal signals during post-silicon debug. Trace Buffers are used to trace (record the values of) the internal signals in real-time when chip is in its normal operation. However, existing trace buffer architectures trace very few signals for a large number of cycles. Thus, even with a good subset of signals traced, one often still cannot restore all the relevant values in the circuit. In this work, we propose two different flexible trace buffer architectures that can restore the values for all signals by making the trace signals configurable. In addition, the buffer space can also be shared among different traced signals which makes the architectures highly flexible. As compared to conventional trace buffer architectures, the new architectures have comparable area overhead but offer the ability to restore all signals in the circuit. For cases of less than 100% restoration, the ability of circuit invariants to improve the signal restoration is explored. A promising direction for the future work is provided where targeted invariants may lead to better restoration scenario during post-silicon validation. / Master of Science

Keratin is a biomaterial derived from biological sources and can be used in a variety of medical applications. This study focuses on keratin derived from human hair. Unfortunately, there is not a lot of information in the literature describing how keratin reacts to subtle changes in an aqueous solution such as differences in pH, keratin concentration, buffer concentration, salt concentration, and temperature. To have a better understanding of this effect, dynamic light scattering was used to test the size ranges and volume percentages in each range. Dynamic light scattering shows the size of the keratin in each environment and its consistency with time. The results showed that there is a difference in keratin behavior between water and buffer solutions, but very subtle differences between each buffer, buffer concentration, keratin concentration, pH and temperature. Keratins aggregate extensively in un-buffered conditions (i.e. pure water), which has implications to both purification and fabrication of biomaterials as water is used extensively in these processes. Interestingly, there was little effect of keratin concentration, pH, and temperature on the buffers used in this study, suggesting there may be a wide range of conditions in which aggregation can be minimized. / Master of Science

Networks which use real-time communication have high requirements on latency and packet loss. Improving one aspect may results in worse performance for another, and it can be difficult to prioritize one over the other as all the requirements need to be met in order for the network tooperate as expected. Many studies have investigated reducing the size of packet buffers to improve the latency. However, they have mainly focused on studying TCP traffic which may not be optimal for real-time traffic, where it instead could be more suitable to use UDP. We have performed an experiment where we compared the performance of real-time traffic over multiple different buffer sizes. We generated traffic using synchronized bursts of packets which were either sample value (SV) or IP packets, as defined by IEC 61850. We measured the packet loss and latency for situations where the traffic was either entirely composed of SV packets, or when it had mixed SV and IP traffic. For the mixed traffic, we also experimented with using different VLAN priorities for the two types of packets. We have determined deadline thresholds that show what size of packet buffer will start causing packets to miss their deadline, and what size will lead every packet in bursts oftraffic to miss their deadlines. We also found that increasing the priority of SV packets in mixed traffic can have either a positive or a negative impact on their performance, depending on how highly they are prioritized.

High variety and low volume manufacturing environment always been a challenge for organisations to maintain their overall performance especially because of the high level of variability induced by ever changing customer demand, high product variety, cycle times, routings and machine failures. All these factors consequences poor flow and degrade the overall organisational performance. For most of the organisations, therefore, process improvement has evidently become the core component for long term survival. The aim of this research here is to develop a methodology for automating operations in process improvement as a part of lean creative problem solving process. To achieve the stated aim, research here has investigated the job sequence and buffer management problem in high variety/low volume manufacturing environment, where lead time and total inventory holding cost are used as operational performance measures. The research here has introduced a novel approach through integration of genetic algorithms based multi-objective combinatorial optimisation and discrete event simulation modelling tool to investigate the effect of variability in high variety/low volume manufacturing by considering the effect of improvement of selected performance measures on each other. Also, proposed methodology works in an iterative manner and allows incorporating changes in different levels of variability. The proposed framework improves over exiting buffer management methodologies, for instance, overcoming the failure modes of drum-buffer-rope system and bringing in the aspect of automation. Also, integration of multi-objective combinatorial optimisation with discrete event simulation allows problem solvers and decision makers to select the solution according to the trade-off between selected performance measures.

A escolha de micro-habitats termais é um processo altamente importante nas linhagens de animais ectotérmicos, que exibem termorregulação. Nas famílias destes animais estão englobadas algumas espécies de anfíbios pequenos, que pelo seu pequeno tamanho, apresentam limitada capacidade de manter temperaturas corporais endógenas independentes do meio ambiente. A regulação da temperatura corporal, nesse sentido, pode exigir comportamentos ativos de escolha de micro-habitats termais incluindo a exploração da paisagem termal, a detecção das temperaturas microambientais (em diferentes localidades), a definição de preferências termais, além de aprendizado e memória de onde estão os locais selecionados para termorregular. Nesta ordem de ideias, o objetivo central da presente dissertação de mestrado foi o de definir o comportamento de escolha de micro-habitat termal por parte do anuro Rhinella ornata, dentro de uma paisagem termal artificial complexa, testando as seguintes hipóteses: (1) Se há preferência termal em um ambiente termal complexo não linear; (2) Havendo preferências, se essas são efetivadas mesmo quando é necessário se expor à condições distantes da preferencial; (3) Quando se explora um ambiente termal mais complexo do que os típicos gradientes lineares, os animais voluntariamente se expõem a temperaturas distantes das chamadas \"preferenciais\". Para testar as hipóteses foi desenhada uma passagem termal artificial de quatro BODs com temperaturas fixas (4.1+1°C, 11.1+1°C, 15.7+1°C e 24.7+1°C), interconectadas por uma arena central. Catorze indivíduos de R. ornata (um por vez, realizando três repetições por indivíduo) foram colocados na areia central e foi filmado todo o comportamento de escolha de micro-habitat durante 72 horas, analisando posteriormente a presença dos indivíduos nas diferentes BODs ao longo dos experimentos. Neste experimento foi encontrado que dentro de uma paisagem termal complexa, quando forem ofertadas as quatro temperaturas fixas, R. ornata apresenta uma preferência termal por locais com temperaturas intermédias (15,7+1°C e 11,1+1°C), sendo que esta preferência foi definida em menos de 12 horas, mas não limito a exploração continua dos outros locais termais. O presente estudo apoia a ideia de que R. ornata \"aprende\" a definir os refúgios termais em menos de 12 horas quando chega em um local novo, e o uso de substratos termais preferidos vai aumentando, mesmo que exista um contínuo forrageio termal do ecossistema / The choice of thermal microhabitats is a highly important process for ectothermic animal which exhibit thermoregulation. Within this group of animals are comprised several species of small amphibians, which limited capacity to maintain endogenous body temperatures independent of the environment. The regulation of body temperature, in this sense, may require active behaviors related with choice of thermal microhabitats, what it includes the exploration of the thermal landscape, the detection of micro-environmental temperatures (in different locations), the definition of termal preferences, as well as learning and memory of where the selected thermoregulate sites are located. The main goal of this thesis was define the behavior of the choice of thermal microhabitat by the anuran Rhinella ornata within an artificial complex thermal landscape, testing the following hypotheses: (1) If there is thermal preference in a complex non-linear termal environment; (2) If there are preferences, if these are effective even when it is necessary to expose oneself to conditions that are far from preferential; (3) When exploring a more complex thermal environment than the typical linear gradients, the animals voluntarily expose themselves to temperatures far from the so-called \"preferential\" ones. To test the hypotheses, an artificial thermal labyrinth of four BODs with fixed temperatures (4.1 ± 1 °C, 11.1 ± 1 °C, 15.7 ± 1 °C and 24.7 ± 1 °C) was constructed and interconnected by a central division. Fourteen individuals of R. ornata (one at a time, performing three replications per individual) were placed in the central division and all behaviors of choice of microhabitat was filmed for 72 hours, analyzing later the presence of the individuals in the different BODs along the experiments. In these experiments were founded that in a complex thermal landscape, when the four fixed temperatures are offered, R. ornata presents thermal preference for locations with intermediate temperatures (15.7 ± 1° C and 11.1 ± 1°C respectively), and this preference was set in less than 12 hours but did not limit the continued exploration of other thermal microhabitats. The presente study supports the idea that R. ornata \"learns\" to define thermal refuges in less than 12 hours when it arrives in a new location, and the use of preferred thermal substrates is increasing, even though he continues the termal foraging of the ecosystem

This thesis is composed of two parts : a 3¡ÑVDD bidirectional mixed-voltage-tolerant I/O buffer, and a 2¡ÑVDD output buffer with process and temperature compensation. In the first topic, a 3¡ÑVDD bidirectional mixed-voltage-tolerant I/O buffer, which is able to tolerate 3¡ÑVDD using stacking transistors in the output stage, is proposed. These transistors are biased by corresponding voltage levels which are generated by a dynamic gate bias generator and a floating N-well circuit when transmitting or receiving signals. In order to prevent the input stage transistors from gate-oxide overstress, an NMOS clamping technique is used to block high input voltages. This design can receive and transmit 0.9 V to 5.0 V (0.9/1.2/1.8/2.5/3.3/5.0 V) signals, which has been implemented using TSMC 1P6M 0.18 £gm CMOS process. The second topic shows a 2¡ÑVDD output buffer with process and temperature compensation using 1P6M 0.18 £gm CMOS process. In this design, a novel process and temperature variation detector is proposed to detect the corners of NMOS and PMOS, respectively. The driving capability of the output stage is enhanced at those corners with low output currents. By contrast, the driving currents is reduced at those corners with high output currents to reduce the variation of output slew rate.

Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 102-110). Also available on the World Wide Web.

Orientador: Fernando Alvarez / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-19T11:28:04Z (GMT). No. of bitstreams: 1 MoralesCorredor_Monica_M.pdf: 2275286 bytes, checksum: d91a17b2e37d2c4976aa37dc6d5d5026 (MD5) Previous issue date: 2011 / Resumo: Dado o interesse nas propriedades e aplicações dos nanotubos de carbono devidas às suas características morfológicas, este trabalho tem como objetivo principal o estudo da influência do substrato no crescimento dos nanotubos de carbono. Com este objetivo em mente foram preparados filmes de nitreto de titânio, com o intuito de ser usados como suporte para a deposição dos nanotubos de carbono. Os nanotubos foram crescidos por decomposição térmica de acetileno, usando partículas de níquel como precursor catalisador. Os filmes finos não estequiométricos de TiNx foram depositados sobre silício cristalino utilizando a técnica de Deposição por Feixe de Íons (IBD). Análise composicional dos substratos mostrou a presença de Ti, N e O. Distintas concentrações destes elementos permitiram a variação na estrutura e dureza dos substratos. Nos filmes bem caracterizados, partículas de níquel e nanotubos de carbono foram crescidos sequencialmente. Os carpetes de nanotubos obtidos no substrato mostraram diferentes densidades populacionais (nanotubos por unidade de área) e diâmetro. Este comportamento está associado com a presença do oxigênio, elemento que inibe o fenômeno conhecido como Ostwald ripening. O efeito de Ostwald ripening55 causa a coalescência do níquel formando partículas maiores a expensas das menores, um estado final mais favoravelmente energético. A presença do oxigênio impede a difusão do níquel na superfície, interferindo no processo de coalescência. Consequentemente, uma grande densidade de partículas catalisadoras por unidade de área é mantida levando a maior densidade de nanotubos assim como modificações morfológicas das nanoestruturas. Portanto, estes resultados indicaram que filmes finos de TiNx, além de atuar como barreira difusora entre as partículas catalisadoras e o substrato de silício, também influencia a cinética dos nanotubos de carbono / Abstract: Given the increasing interest in the properties and applications of carbon nanotubes due to their morphological characteristics, this work has as main objective the study of the influence of substrate on the growth properties of carbon nanotubes. With this main goal in mind were first prepared titanium nitride films in order to be used as substrate support for carbon nanotubes deposition. The nanotubes were growth by thermal decomposition of acetylene using nickel particles as catalyst precursors. The thin films non-stoichiometric TiNx were deposited on crystalline silicon by ion beam deposition (IBD) technique. Compositional analysis of the substrates showed the presence of Ti, N and O. The different concentrations of these elements led to the variation in the structure and hardness of the coating. On the well characterized substrate coating, nickel particles and nanotubes growth were sequentially deposited. The quite well organized carpets of nanotubes obtained on the substrate show different population density (nanotubes per unit of area) and diameter. This behavior is associated with the presence of oxygen, element inhibiting the phenomenon known as ¿Ostwald ripening?. The Ostwald ripening effect55 causes the coalescence of nickel by forming bigger nickel particles at expenses of smaller ones, a more energetic favorable final state. The presence of oxygen prevents the nickel surface diffusion and thus interfering on the coalescence process. Consequently, a larger density of relatively small catalyst nickel islands per unit of area is preserved leading to higher nanotubes density as well as morphology modifications of the nano structures. Therefore, these results indicate that thin films of TiNx, besides acting as diffusion barrier between the catalyst particles and the silicon substrate also influences the kinetics of growth of carbon nanotubes / Mestrado / Mestra em Física

L’expérience GBAR repose sur la production d’ions antihydrogène positifs dans le but de mesurer l’accélération gravitationnelle à laquelle est soumise l’antimatière au repos. Le projet ANTION, sous-projet de GBAR, a pour but la production de ces ions d’antimatière. Il vise également à mesurer la section efficace de production d’antihydrogène dans les collisions d’antiprotons sur des atomes de positronium, ainsi que les sections efficaces correspondantes avec la matière, de production d’hydrogène et de l’ion hydrogène négatif. Ces expériences reposent sur la formation d’un nuage très dense de positronium, et nécessitent donc une grande quantité de positons qui seront implantés sur un matériau convertisseur de positons en positronium. Cette thèse décrit la construction d’un piège à “buffer gas” à trois étages, destiné à piéger et accumuler des positons pour le projet ANTION. L’association d’un piège de Penning avec une source basée sur un Linac constitue un montage expérimental unique. Le piège a été construit et optimisé, et est maintenant pleinement opérationnel. Les protocoles de piégeage ont été étudiés et les effets du gaz tampon et du gaz de refroidissement sur le taux de piégeage et la durée de vie des positons ont été quantifiés. Afin de faciliter la mesure de la section efficace de production de l’hydrogène, une simulation avec GEANT4 a été mise au point. Elle décrit l’évolution temporelle et spatiale des atomes d’ortho-positronium dans la cavité où aura lieu la production d’hydrogène. On estime que 2.7 atomes d’hydrogène sont produits pour des proton de 6 keV d’énergie incidente, en utilisant les sections efficaces calculées avec le modèle “Coulomb-Born Approximation”, et 1.6 atomes d’hydrogène pour des protons de 10 keV, si l’on utilise la méthode “two-center convergent close-coupling”. Les simulations permettent également d’estimer le bruit de fond associé aux positons et à l’annihilation du para-positronium. Cette étude amène à proposer une modification permettant d’augmenter le nombre d’atomes de positronium dans la cavité. En parallèle, une étude a porté sur l’efficacité de modération de positons d’une couche épitaxiale de carbure de silicium 4H-SiC. Une efficacité de modération de 65% a été mesurée pour des positons implantés avec une énergie de l’ordre du kilo- électronvolt. Ce résultat intéresse les expériences de physique utilisant des positons lents, car il permet d’améliorer la luminosité de faisceaux de positons; dans le cas de GBAR cela permettrait d’augmenter l’efficacité de piégeage des positons. / The GBAR experiment relies on the production of antihydrogen positive ions to achieve its goal of measuring the gravitational acceleration of antimatter at rest. The ANTION project, included in the GBAR enterprise, is responsible for the production of these antimatter ions. Moreover, it also aims to measure the cross section of antihydrogen production throughout the collision of antiprotons and positronium atoms, as well as the matter cross sections of hydrogen and the hydrogen negative ion. These experiments imply the formation of a very dense positronium cloud, thus a large amount of positrons will be implanted on a positron/positronium converter material. This thesis reports the construction of a three stage buffer gas trap with the goal of trapping and accumulating positrons for the ANTION project. The combination of the Penning-type trap with a LINAC source constitutes a unique experimental setup. The trap was commissioned and optimized and is now fully operational. Trapping protocols were studied and the effect of the buffer and cooling gases on the positron trapping rate and lifetime was assessed. In order to assist the cross section measurement of hydrogen, a GEANT4 simulation was developed. It evaluates the time and spatial evolution of the ortho-positronium atoms in a cavity, where hydrogen production will take place. It was estimated that 2.7 hydrogen atoms are produced for proton impact energy of ∼ 6 keV, according to the cross sections computed with the Coulomb-Born Approximation model, and 1.6 hydrogen atoms for a proton impact energy of ∼ 10 keV, according to the two-center convergent close-coupling method. The simulations also allow the estimation of the background associated with the positron and para-positronium decay. In addition, a suggestion is proposed to increase the number of positronium atoms in the cavity. In parallel, the positron moderation efficiency of a commercially available 4H-SiC epitaxial layer was studied. A 65% moderation efficiency was observed for kiloelectronvolt implanted positrons. This result can be of interest to slow positron physics experiments by improving the brightness of positron beams, and in particular to GBAR as it can potentially increase the efficiency of positron trapping.

Hydrophilic interaction liquid chromatography is a frequently used separation method for analysis of polar compounds. It is an alternative method to reversed-phase chromatography, where these compounds show insufficient or very weak retention. A high number of stationary phases are currently available for HILIC and new ones are still being developed. The aim of this diploma thesis was to characterize and compare three relatively new HILIC columns containing an unmodified silica gel (HILIC-A), aminopropyl modified silica (HILIC-B) and polyhydroxyl chain modified silica (HILIC-N) as stationary phase. Based on the study of the effect of acetonitrile content in mobile phase on the retention of a model set of peptides, a multimodal retention mechanism was demonstrated. Analysis of 18 model analytes with different pKa values showed, that the composition of aqueous part of mobile phase (buffer), more specifically it's concentration and pH value, has a significant impact on retention of ionized analytes and peptides on the studied stationary phases. A significant contribution of ionic interactions to retention was observed on HILIC-B and HILIC-A columns. The retention of basic compounds on the HILIC-B column increased with increasing ionic strength, while it decreased on the HILIC-A column. Increasing the...