Background. Smart door locks are either replacing or adding on to more regular mechanical locks today. They come in many different sizes and with many different functionalities. Today, most consumer advertisements focus on the functionalities of the locks and not so much on security. A few years ago when the locks started first to appear, they were very easily hacked and dedicated hackers could ride along the road and unlock people's doors with ease. As this is not the case as it was then, the problem persists. Insecure locks exist but consumer media focuses only on functionality, how are consumers making their purchases? In blind faith or with educated guesses? Objectives. This thesis tends to find out if consumers research the security of a smart lock, how do they research it, and is it enough for them? What sources do they consider before purchasing a lock and do they trust the sources? Can an application with security as its main focus aid or change consumers' methods of research? Methods. To begin answering these questions knowledge of the subject is necessary. Therefore, a literature study was conducted in order to find out what aspects of a smart door lock are more or less secure. To answer the first research question a questionnaire was created to collect quantitative data. This questionnaire contained questions about the participants' knowledge of the subject. Then, interviews were held in order to gather qualitative data for answering the second research question. During the interviews, participants got to test a prototype application helping them understand the subject of the questions. Results. The result shows that a majority of the participants are conscious of security regarding smart locks, 59.8% even think it is the most important aspect. The results from the interviews show that people do want an application suggesting smart locks with security in mind. Conclusions. The research here shows that smart door lock consumers value security. Consumers are also aware that consumer media does not value it as much. However, what is left unanswered is if the consumers care enough to do their own research before purchasing a smart door lock?

Submitted by William Justo Figueiro (williamjf) on 2015-06-16T23:47:58Z No. of bitstreams: 1 27.pdf: 3460975 bytes, checksum: 6fb4884eb12bbee8490b27b6414b47c0 (MD5) / Made available in DSpace on 2015-06-16T23:47:58Z (GMT). No. of bitstreams: 1 27.pdf: 3460975 bytes, checksum: 6fb4884eb12bbee8490b27b6414b47c0 (MD5) Previous issue date: 2013-08 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / FINEP - Financiadora de Estudos e Projetos / Furnas Centrais Elétricas / Comportas segmento invertidas são frequentemente utilizadas no controle do enchimento e esgotamento de eclusas de navegação de alta queda. Durante o período de abertura, altas velocidades e flutuações de pressão ocorrem a jusante destas comportas, o que aumenta o potencial para a ocorrência de cavitação no escoamento. Neste trabalho buscou-se analisar por meio de simulação numérica as características do escoamento a jusante de uma comporta segmento invertida. O modelo matemático é bifásico, tridimensional e composto pelas equações da conservação da massa, quantidade de movimento, fração volumétrica e equações do modelo de turbulência. O modelo computacional foi desenvolvido com o software comercial ANSYS-CFX, com malha computacional do tipo hexaédrica. Perfis de pressões no teto e na base do conduto a jusante da comporta foram utilizados para validação do modelo numérico com resultados experimentais, provenientes de estudos realizados pelo IPH-UFRGS (Instituto de Pesquisas Hidráulicas da Universidade Federal do Rio Grande do Sul). A comparação entre os resultados mostrou que o modelo numérico reproduz com boa precisão as principais características do escoamento médio observado no modelo experimental. Os coeficientes hidráulicos calculados para os resultados numéricos também mostraram boa concordância com os resultados do modelo experimental e com os disponíveis na literatura. A análise do campo de pressões mostrou que as pressões mínimas encontram-se sob a borda da comporta. Além disso, verificou-se por meio do campo de tensões cisalhantes na base do conduto e por meio de vetores de velocidade um padrão de escoamento tridimensional no jato a jusante da comporta, caracterizado pela presença de regiões de rotação próximo da base e das paredes. / Reversed Tainter gates are often used to control the filling and emptying of high lift navigation locks. During the opening period, high velocities and pressure fluctuations occur downstream the gates, which increases the potential for the occurrence of cavitation in the flow. In this work we seek to analyze by means of numerical simulation the characteristics of the flow downstream of a reversed Tainter gate. The computational model was validated by comparing the profiles of pressure of the roof and at the base of the conduit downstream of the gate with the average pressure profiles obtained in an experimental model from studies conducted by IPH-UFRGS. A comparison of the results showed that the model reproduced with good accuracy the main flow characteristics observed in experimental medium. The hydraulic coefficient calculated for the numerical results also showed good agreement with experimental results and those available in the literature. The analysis of the pressure field showed that the minimum pressures are under the edge of the gate. Furthermore, it was found by means of the shear stress at the base of the conduit and through velocity vector a threedimensional pattern in the jet flow downstream of the gate, characterized by the presence of vortex near the base and walls.

Archaeological investigations of the Gronauer lock #2 revealed the presence of the well-preserved lower portion of the lock and associated cribbing. Clearing of the fill in the lock proper and wing area and test excavations in the southern cribbing provided important details on the construction of the lock which were not completely consistent with the historical documentation and building specifications. Few artifacts directly associated with the construction and use of the lock were found although significant numbers of secondarily deposited artifacts from the adjacent lockkeeper's house were recovered. Dating of the artifacts was consistent with the recorded history of the construction and use of the lock. In general, without the physical details recovered through the archaeological investigations, interpretations of the site from the written records alone would have presented an inaccurate view of the actual situation.Ball State UniversityMuncie, IN 47306 / Department of Anthropology

Submitted by Luiz Felipe Barbosa (luiz.fbabreu2@ufpe.br) on 2015-03-09T13:43:25Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO Francisco Miranda Soares da Silva Neto.pdf: 1968720 bytes, checksum: 60383d7751d95b545cae9a16a83f611c (MD5) / Made available in DSpace on 2015-03-09T13:43:26Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO Francisco Miranda Soares da Silva Neto.pdf: 1968720 bytes, checksum: 60383d7751d95b545cae9a16a83f611c (MD5) Previous issue date: 2014-02-27 / In recent years, the diminishing rate with which we can increase the amount of transistors in a processor core has slowed down the increase of computers’ power. Moore’s Law appears to be drawing to an end. With it, the assumption that software written today will be more efficiently executed in the future simply due to processors’ evolution is being challenged. On the other hand, parallel applications can still be made more efficient by distributing work among different processors to be executed at the same time, thus reducing overall execution time. To enable parallelization, we must have multiple processor cores. This has led to the popularization of multicore architectures. However, writing parallel applications is not trivial. A program must be either written from the start to be executed in parallel, or later adapted for parallel execution. The programmer has the error-prone task of parallelizing the application through use of concurrency and parallelism constructs. Locking, the most common concurrency option, presents risks for inexperienced programmers, such as the famous Deadlock and Livelock problems. As we move from single core architectures to multicore, our programming languages need to make it easier for the programmers to use concurrency. Many researchers have pointed at Software Transactional Memory (STM) as an answer to that issue, as it is a lock-free, abstract way to guarantee isolated access to shared resources. But adapting for STM a program that uses lock is not simple. Besides being an error-prone task, technical details of the language might require special attention to preserve the program’s behavior. In this dissertation, we propose a set of program transformations for concurrency constructs in Haskell, a purely functional programming language. They may be used to refactor a program’s existing locks into transactional constructs from Haskell’s STM implementation. This allows a programmer to gain the benefits of working on STM even for programs which were already developed using locks. Each transformation is accompanied by execution examples and a discussion on its ability to preserve program behavior. We also present a supporting study, in which a controlled experiment was used to evaluate the benefits of locks or STM for the development of Haskell programs. Although subjects’ opinions tended to favor lock-based concurrency, those which used STM overall committed significantly fewer mistakes and required on average 12% less time to finish their assignments. / Recentemente, a queda na taxa de crescimento da quantidade de transístores integráveis em processadores tem desacelerado o crescimento de poder computacional. A lei de Moore parece aproximar-se de seu fim. Com isso, é desafiada a premissa de que software escrito hoje terá melhor desempenho no futuro simplesmente devido à evolução dos processadores. Ainda assim, aplicações paralelas ainda podem se tornar mais eficientes ao se distribuir trabalho entre diferentes processadores para execução simultânea. Para permitir a paralelização, são necessários múltiplos núcleos de processamento, o que tem levado à popularização de arquiteturas multinúcleo. Entretanto, a escrita de aplicações paralelas não é trivial. Deve-se escrever um programa para execução paralela desde sua concepção, ou adaptá-lo posteriormente para execução paralela. O programador tem a difícil tarefa de paralelização da aplicação através do uso de construções de concorrência e paralelismo. Travas, a mais comum opção para concorrência, apresentam riscos para programadores inexperientes, tais quais os famosos problemas de Deadlock e Livelock. Ao adaptarem-se de arquiteturas de um único núcleo para as de multinúcleo, as linguagens de programação precisam facilitar o uso de concorrência para os programadores. Muitos pesquisadores têm indicado Memória Transacional em Software (STM, do inglês Software Transactional Memory) como a resposta para esse problema, por ser uma forma abstrata e não bloqueante para garantia de acesso isolado a recursos compartilhados. Mas adaptar para STM programas que usam travas não é simples. Além de ser uma atividade propensa a erros, detalhes técnicos da linguagem podem requerer cuidados para se preservar o comportamento do programa. Nesta dissertação, é proposto um conjunto de transformações de programas para construções de concorrência em Haskell, uma linguagem de programação puramente funcional. Elas podem ser usadas para refatorar travas de um programa para uso de construções transacionais da implementação de STM em Haskell. Isso permite ao programador aproveitar os benefícios do trabalho com STM mesmo para programas já desenvolvidos com uso de travas. Cada transformação é acompanhada de exemplos de execução e uma discussão sobre sua capacidade de preservar o comportamento do programa. Também é apresentado um estudo de apoio, no qual um experimento controlado foi usado para avaliar os benefícios do uso de travas ou STM no desenvolvimento de programas em Haskell. Apesar das opiniões dos participantes terem favorecido o uso de travas, aqueles que usaram STM cometeram em geral menos erros e em média precisaram de 12% a menos de tempo para terminar suas tarefas.

The design of microprocessors is undergoing radical changes that affect the performance and reliability of hardware and will have a high impact on software development. Future systems will depend on a deep collaboration between software and hardware to cope with the current and predicted system design challenges. Instead of higher frequencies, the number of processor cores per chip is growing. Eventually, processors will be composed of cores that run at different speeds or support specialized features to accelerate critical portions of an application. Performance improvements of software will only result from increasing parallelism and introducing asymmetric processing. At the same time, substantial enhancements in the energy efficiency of hardware are required to make use of the increasing transistor density. Unfortunately, the downscaling of transistor size and power will degrade the reliability of the hardware, which must be compensated by software. In this thesis, we present new algorithms and tools that exploit speculative and asymmetric execution to address the performance and reliability challenges of multicore architectures. Our solutions facilitate both the assimilation of software to the changing hardware properties as well as the adjustment of hardware to the software it executes. We use speculation based on transactional memory to improve the synchronization of multi-threaded applications. We show that shared memory synchronization must not only be scalable to large numbers of cores but also robust such that it can guarantee progress in the presence of hardware faults. Therefore, we streamline transactional memory for a better throughput and add fault tolerance mechanisms with a reduced overhead by speculating optimistically on an error-free execution. If hardware faults are present, they can manifest either in a single event upset or crashes and misbehavior of threads. We address the former by applying transactions to checkpoint and replicate the state such that threads can correct and continue their execution. The latter is tackled by extending the synchronization such that it can tolerate crashes and misbehavior of other threads. We improve the efficiency of transactional memory by enabling a lightweight thread that always wins conflicts and significantly reduces the overheads. Further performance gains are possible by exploiting the asymmetric properties of applications. We introduce an asymmetric instrumentation of transactional code paths to enable applications to adapt to the underlying hardware. With explicit frequency control of individual cores, we show how applications can expose their possibly asymmetric computing demand and dynamically adjust the hardware to make a more efficient usage of the available resources.

Det ständigt växande e-handelssegmentet ställer helt nya krav på transporter inom sista milenleveranser. Sista milen är ofta förknippad med negativa externaliteter som buller, trängsel ochutsläpp och dessutom låg kostnadseffektivitet. Sista milen är därför en del i logistikkedjan somhar stor förbättringspotential. Det har därför på senare tid uppkommit en del innovationer inomsista milen som ska kunna öka effektiviteten och minska de negativa externaliteterna.I denna studie har vi, med hjälp av virtuella fokusgruppsintervjuer, undersökt åtta individersinställning till tre olika innovativa leveransmetoder; crowdsourcing, paketskåp och smarta lås.Vi har även undersökt vad det är som påverkar denna inställning och antagandet av dem, samt vilka förväntningar som individerna har på nya leveranssätt. Till vår hjälp har vi bland annat haft teori kring hur individer antar nya innovationer, vad en tjänsteinnovation är samt tidigare forskning om våra undersökta leveranssätt. Fortsättningsvis har vi även haft teori kring upplevd risk och vad som skapar värde för kunder. Med hjälp av dessa teorier kunde vi i analysen besvara våra frågeställningar. Det visade sig att deltagarna generellt sett har en negativ inställning till crowdsourcing och smarta lås som leveranssätt. Beträffande paketskåp fanns en generellt sett positiv inställning. Det var också det leveranssätt som många deltagare provat tidigare. De är generellt sett nöjda med de leveranssätt som redan existerar och därför är intresset för innovativa leveranssätt inte så stort. Vid diskussioner gällande samtligaleveranssätt fördes resonemang kopplat till värde och risk. Beträffande både inställningen tillinnovationerna och förväntningarna på dem uppfattar vi det som att relativa fördelar,komplexitet och kompatibilitet spelar stor roll vid antagande av innovationer. Även recensioneroch “word of mouth” har visat sig spela in. / A continuously growing B2C e-commerce sector creates new challenges and a differentdemand in the transport sector, especially in the final step of a logistic supply chain - the lastmile delivery. Furthermore, the last mile is also known as the least cost effective part of alogistic chain as well as the part that is associated with negative externalities like congestion,air pollution and noise pollution, especially in urban areas. Considering this, the last mile is apart with high potential of improvement. This is also why last mile delivery innovations arestarting to show up on the market.With the help of virtual focus group methodology, we have in this study aimed to investigateeight people’s attitude towards three last mile delivery innovations; crowdsourcing, parcellockers and smart locks. We have studied things that can have an affect on this attitude and the adoption of innovations, but also what expectations the customers have on last mileinnovations in general. To be able to analyze our data, we have used a variety of theories,including Diffusion of innovations theory, and theories regarding customer value, risk andservice innovation. Regarding our three service innovations, we have also included previousresearch concerning those.Our research showed a negative attitude towards crowdsourcing and smart locks, and a positive attitude towards parcel lockers, which also was the innovation that a lot of our participants had tried. In general, all participants were satisfied with existing delivery methods, why the motivating factors for using the innovations are few. Discussions regarding customer value and risk were influential in our results. We also found mutual factors in what affects attitude and expectations, factors like complexity, compatibility and relative advantages. Furthermore, reviews and word of mouth also seem to have an affect on their attitude towards the innovations.

Submitted by Mariana Dornelles Vargas (marianadv) on 2015-04-09T18:40:24Z No. of bitstreams: 1 influencia_caracteristicas.pdf: 5180915 bytes, checksum: df667ffda685e6774d46e64735e32e82 (MD5) / Made available in DSpace on 2015-04-09T18:40:25Z (GMT). No. of bitstreams: 1 influencia_caracteristicas.pdf: 5180915 bytes, checksum: df667ffda685e6774d46e64735e32e82 (MD5) Previous issue date: 2012 / Nenhuma / Este trabalho apresenta um estudo de comportamento fluidodinâmico na operação de válvula do tipo segmento invertida, utilizadas em sistemas de enchimento e esvaziamento de navegação de eclusas. Nesta pesquisa é verificada a influência da alteração geométrica no conduto a jusante da comporta. O objetivo principal é encontrar dentre alterações geométricas aquela que oferece melhores condições de operação, isto é, minimizando os efeitos nocivos provocados pelas baixas pressões. O estudo é realizado através de abordagem numérica (CFD -Computer Fluid Dynamics), com o software comercial ANSYS-CFX, utilizando-se as equações da conservação da massa e quantidade de movimento como modelo básico. Foram simulados 3 comprimentos de expansão (Lexp = 0,3, 0,6 e 0,9 m) no teto a jusante da comporta, mantendo a mesma inclinação (1E:10 Lexp, onde E é a elevação do teto). Para cada comprimento de expansão foram simuladas 3 vazões (Q) e 3 aberturas (a), totalizando 27 simulações.As comparações entre os resultados numéricos para as expansões propostas são realizadas a partir do modelo numérico (original) já validado em trabalhos publicados. Também são feitas análises de parâmetros, como: alterações geométricas, pressões mínimas, regiões do conduto submetidas à pressões críticas (negativas), recuperação da pressão, coeficientes de perda de carga e de contração. Estas análises permitiram observar qual a influência da expansão no escoamento, mostrando que a simulação numérica pode ser utilizada como de apoio na definição de novas geometrias a serem adotadas nos projetos de novas eclusas, bem como na avaliação de eclusas já existentes identificando condições de operação nocivas na região junto a comporta. Verifica-se neste trabalho que as alterações geométricas propostas não são capazes de resolverem os problemas relativos às pressões negativas, e que seu desempenho depende das condições operação (principalmente a vazão). Contudo, quanto maiores forem as vazões, maiores serão as pressões mínimas obtidas com a expansão para o teto. Espera-se que os resultados obtidos possam ser usados como base para projetos, visando à diminuição dos efeitos nocivos na válvula (como cavitação, vibrações, erosões, ruídos e esforços espasmódicos) e perturbações que danificam as embarcações, durante a operação dentro da eclusa. / This paper presents a study of fluid dynamic behavior in the operation of inverted Tainter gate, used in filling and emptying systems of navigation locks. In this research is verified the influence of geometric change in the conduit downstream of the gate. The main objective is to find among geometric changes one that offers the best operating condition, i.e., minimizing the harmful effects of low pressures. The study is conducted through numerical approach (CFD-Computer Fluid Dynamics) with the commercial software ANSYS-CFX, using the equations of conservation of mass and momentum as the basic model. Were simulated 3 expansion lengths (Lexp = 0.3, 0.6 and 0.9 m) in the roof of downstream gate, keeping the same slope (1E:10 Lexp, where E is the elevation of the roof). For each expansion length were three simulated stream flow (Q) and 3 openings (a), totaling 27 numerical simulations. Comparisons between the numerical results for the proposed expansions are made from the numerical model (original) previously validated in published works. Also analysis are made of parameters such as geometric changes, minimum pressures, the conduit regions undergoing critical pressures (negative) pressure recovery, pressure loss and contraction coefficients. This analysis allowed observing the influence of the expansion in the flow, showing that the numerical simulation can be used to support the definition of new geometries to be adopted in the design of new navigation locks, as well as evaluation of existing locks, identifying the harmful operating conditions in the region near the gate. It is verified in this work that the geometric changes proposed are not able to solve the problems relating to negative pressures, and its performance depends on operating conditions (mainly the flow). However, the higher the flow rate, the greater the pressures obtained with minimal expansion to the roof. It is hoped that the results obtained can be used as a basis for projects in order to reduce the harmful effects on the valve (as cavitation, vibration, erosion, noise and spasmodic efforts) and disorders that damage the vessels, while operating within the lock.

La evolución tecnológica en el diseño de microprocesadores ha conducido a sistemas paralelos con múltiples hilos de ejecución. Estos sistemas son más difíciles de programar y presentan overheads mayores que los sistemas uniprocesadores tradicionales, que pueden limitar su rendimiento y escalabilidad: sincronización, coherencia, consistencia y otros mecanismos requeridos para garantizar una ejecución correcta. La programación paralela tradicional se basa en primitivas de sincronización como barreras y locks de lectura/escritura, con alta tendencia a fallos de programación. La Memoria Transaccional (TM) oculta estos problemas de sincronización al programador; sin embargo, múltiples sistemas TM aún se basan en locks, y se beneficiarían de una implementación eficiente de los mismos.Esta tesis presenta nuevas técnicas hardware para acelerar la ejecución de estos programas paralelos. Proponemos un sistema TM híbrido basado en locks de lectura/escritura, que minimiza los overheads del software cuando la aceleración hardware está presente. Desarrollamos un mecanismo para garantizar fairness entre transacciones hardware y software. Introducimos un mecanismo distribuido de aceleración de locks de lectura/escritura, llamado Lock Control Unit. Finalmente, proponemos una organización de multiprocesadores basadas en Kilo-Instruction Processors que garantiza Consistencia Secuencial y permite especulación en secciones críticas. / Technological evolution in microprocessor design has led to parallel systems with multiple execution threads. These systems are more difficult to program and present higher performance overheads than the traditional uniprocessor systems, what may limit their performance and scalability: synchronization, coherence, consistency and other mechanisms required to guarantee a correct execution. Traditional parallel programming is based on synchronization primitives such as barriers, critical sections and reader/writer locks, highly prone to programming errors. Transactional Memory (TM) removes the synchronization problems from the programmer. However, many TM systems still rely on reader/writer locks, and would get benefited from an efficient implementation.This thesis presents new hardware techniques to accelerate the execution of such parallel programs. We propose a Hybrid TM system based on reader/writer locks, which minimizes the software overheads when acceleration hardware is present, still allowing for correct software-only execution. We propose a mechanism to guarantee fairness between hardware and software transactions is provided. We introduce a low-cost distributed mechanism named the Lock Control Unit to handle fine-grain reader-writer locks. Finally, we propose an organization of a mutiprocessor based on Kilo-Instruction Processors, which guarantees Sequential Consistency while allowing for speculation in critical sections.

Ο στόχος της διπλωματικής αυτής εργασίας είναι η μελέτη ενός διαφορικού ταλαντωτή Collpits ο οποίος λειτουργεί ως διαιρέτης συχνότητας με έγχυση ρεύματος στην πηγή, χαμηλού θορύβου και διαφορικής εισόδου, ως προς την κατανάλωση και το θόρυβο. Επίσης συγκρίνεται η απόδοσή του σε αυτούς τους τομείς με την απόδοση άλλων τοπολογιών αναλογικών διαιρετών συχνότητας αλλά και ψηφιακών. / The objective of this thesis is to study a Collpits differential oscillator which works as a low noise and differential input, current source injection frequency divider, by taking into account consumption and noise. Also the performance in these areas is compared with other topologies of analogue and/or digital frequency dividers.

The design of microprocessors is undergoing radical changes that affect the performance and reliability of hardware and will have a high impact on software development. Future systems will depend on a deep collaboration between software and hardware to cope with the current and predicted system design challenges. Instead of higher frequencies, the number of processor cores per chip is growing. Eventually, processors will be composed of cores that run at different speeds or support specialized features to accelerate critical portions of an application. Performance improvements of software will only result from increasing parallelism and introducing asymmetric processing. At the same time, substantial enhancements in the energy efficiency of hardware are required to make use of the increasing transistor density. Unfortunately, the downscaling of transistor size and power will degrade the reliability of the hardware, which must be compensated by software. In this thesis, we present new algorithms and tools that exploit speculative and asymmetric execution to address the performance and reliability challenges of multicore architectures. Our solutions facilitate both the assimilation of software to the changing hardware properties as well as the adjustment of hardware to the software it executes. We use speculation based on transactional memory to improve the synchronization of multi-threaded applications. We show that shared memory synchronization must not only be scalable to large numbers of cores but also robust such that it can guarantee progress in the presence of hardware faults. Therefore, we streamline transactional memory for a better throughput and add fault tolerance mechanisms with a reduced overhead by speculating optimistically on an error-free execution. If hardware faults are present, they can manifest either in a single event upset or crashes and misbehavior of threads. We address the former by applying transactions to checkpoint and replicate the state such that threads can correct and continue their execution. The latter is tackled by extending the synchronization such that it can tolerate crashes and misbehavior of other threads. We improve the efficiency of transactional memory by enabling a lightweight thread that always wins conflicts and significantly reduces the overheads. Further performance gains are possible by exploiting the asymmetric properties of applications. We introduce an asymmetric instrumentation of transactional code paths to enable applications to adapt to the underlying hardware. With explicit frequency control of individual cores, we show how applications can expose their possibly asymmetric computing demand and dynamically adjust the hardware to make a more efficient usage of the available resources.