Piling is expensive but often necessary when building large structures, for example bridges. Some pile types, such as steel core piles, are very costly and it is therefore of great interest to keep the number piles in a pile group to a minimum. This thesis deals with optimization of pile groups with respect to placement, batter and angle of rotation in order to minimize the number of piles. A program has been developed, where two optimization algorithms named Genetic Algorithm and Direct Search, and four objective functions have been used. These have been tested and compared to find the most suitable for pile group optimization. Three real cases, two bridge supports and one culvert, have been studied, using the program.  It has been difficult to draw any clear conclusions since the results have been ambiguous. This is probably because only three cases have been tested and the results are very problemdependent.The outcome depends, for example, on the starting guess and settings for the optimization. However, the results show that the Genetic Algorithm is somewhat more robust in its ability to remove piles than Direct Search and is therefore to prefer in pile group optimization.

This paper presents an approach to operate multi-objective self-optimizing software systems based on the models@run.time paradigm. In contrast to existing approaches, which are usually specific to a single or selected set of objectives (e.g., performance and/or reliability), the presented approach is generic in that it allows the software architect to model the relevant concerns of interest to self-optimization. At runtime, these models are interpreted and used to generate optimization problems. To evaluate the applicability of the approach, a scalability analysis is provided, showing the approach’s feasibility for at least two objectives.

Im Vortrag wird das Vorgehen zur Konstruktionsoptimierung mittels parametrischer FE-Simulation beschrieben. Die einzelnen Schritte werden dargestellt und am Beispiel eines Übertragungselements für Klauenkupplungen erläutert. Zunächst wird der Optimierungsgegenstand vorgestellt und die Festlegung der Entwurfsvariablen und Zielfunktionen beschrieben. Im Anschluss werden die Erstellung des FE-Modells und die Durchführung der Optimierungsrechnung schrittweise erläutert. Abschließend folgen ein Vergleich verschiedener Optimierungsmethoden und die Zusammenfassung. Als Software wurden ANSYS und Autodesk Inventor verwendet.

Though still in relative infancy, the field of flapping flight has potential to have a far-reaching impact on human life. Nature presents a myriad of examples of successful uses of this locomotion. Human efforts in flapping flight have seen substantial improvement in recent times. Wing kinematics are a key aspect of this study. This study summarizes previous wing trajectory generators and presents a new trajectory generation method built upon previous methods. This includes a novel means of commanding unequal half-stroke durations subject to robotic trajectory continuity requirements. Additionally, previous optimization methods are improved upon. Experimental optimization is performed using the new trajectory generation method and a more traditional means. Methods for quantifying and compensating for sensor time-dependence are also discussed. Results show that the Polar Fourier Series trajectory generator advanced rapidly through the optimization process, especially during the initial phase of experimentation. The Modified Berman and Wang trajectory generator moved through the design space more slowly due to the increased number of kinematic parameters. When optimizing lift only, the trajectory generators produced similar results and kinematic forms. The findings suggest that the objective statement should be modified to reward efficiency while maintaining a certain amount of lift. It is expected that the difference between the capabilities of the two trajectory generators will become more apparent under such conditions.

In design of bridges and for estimation of dynamic properties and load carrying capacity Finite Element Method (FEM) is often used as a tool. The physical quantities used in the Finite Element (FE) model are often connected to varying degrees of uncertainty. To deal with these uncertainties conservative parameter estimates and safety factors are used. By calibrating the bridge FE model to better fit with the response of the real structure, less conservative parameter values can be chosen. This method of comparing measured and response with estimates from a FE model and calibrating the model parameters is called Finite Element Model Updating (FEMU). In the present thesis different aspects of FEMU are investigated. The first part comprises a literature review covering all aspects of FEMU with special focus on the choice of updating parameters, objective functions for iterative updating procedures and the automatic pairing of modes. This part is concluded with a flowchart suggesting a systematic approach to a FEMU project. In the second part of the text two bridge case studies are presented. In the first case study a railway bridge in the north of Sweden is studied. A detailed FE bridge model from a previous project is used as a simulation model for extraction of modal data by eigenvalue analysis. Then simplified models are created and attempts to update these models are performed. The updating parameters are chosen based on a simple sensitivity analysis. Tests are performed to investigate the influence of chosen updating parameters and objective function on the computational cost and the quality of the updated model. Case study number two is more comprehensive and focuses on the sensitivity analysis for the choice of updating parameters and on the choice of objective function. A road bridge in the Stockholm area is used and as for case study one a detailed model from a previous project is used as simulation model. Also a new criteria for the automatic pairing of modes is presented and tested. In the end an attempt to verify two of the updated models is performed. / <p>QC 20150825</p>

No description available.

The use of Internet of Things systems has increased to meet the need for smart systems in various fields, such as smart homes, intelligent industries, medical systems, agriculture, and the military. IoT networks are expanding daily to include hundreds and thousands of IoT devices, which transmit information through other linked devices to reach the network sink or gateway. The information follows different routes to the network sink. Finding an ideal routing solution is a big challenge due to several factors, such as power, computation, storage, and memory limitation for IoT devices. In 2011, A new standardized routing protocol for low-power and lossy networks was released by the Internet Engineering task force (IETF). The IETF adopted a distance vector routing algorithm for the RPL protocol. RPL protocol utilizes the objective functions (OFs) to select the path depending on diffident metrics.These OFs with different metrics must be evaluated and tested to develop the best routing solution.This project aims to test the performance of standardized RPL objective functions in a simulation environment. Afterwards, a new objective function with a new metric will be implemented and tested in the same environmental conditions. The performance results of the standard objective functions and the newly implemented objective function will be analyzed and compared to evaluate whether the standard objective functions or the new objective function is better as a routing solution for the IoT devices network.

Esta tese de doutorado aborda os tópicos de modelagem e de reconhecimento de objetos estruturados, ou sistemas estruturados de objetos, em imagens. Um objeto ou sistema estruturado é aquele que pode ser descrito através de elementos primitivos que o compõem e pelas relações existentes entre esses elementos. Por exemplo, uma aeronave pode ser descrita pelos seguintes elementos primitivos: asas direita e esquerda, fuselagem e cockpit. O aspecto relacional de um objeto estruturado direciona sua representação computacional e seu reconhecimento em imagens ao paradigma estrutural de reconhecimento de padrões. Contudo, a variabilidade das características dos seus elementos primitivos é melhor representada através do paradigma estatístico de reconhecimento de padrões. Devido à complementaridade dos paradigmas, a conjunção dessas abordagens é um tema de pesquisa de interesse atual. Para conjugar esses dois aspectos, esta tese propôs uma metodologia que combina o conhecimento a priori das relações que caracterizam um objeto estruturado com dados estatísticos coletados de amostras desse objeto, num modelo híbrido denominado grafo estatístico-relacional (GER). Segundo essa representação, foi estudada uma abordagem probabilística para reconhecer um objeto estruturado em imagens. Nesse cenário, o GER modelo é considerado uma variável aleatória, enquanto uma rotulação de uma imagem de entrada é interpretada como uma potencial observação do modelo. A tarefa de reconhecimento foi então formulada como um problema de otimização, que busca maximizar a probabilidade da observação de acordo com o modelo. O método foi aplicado à modelagem de órgãos abdominais em imagens de ressonância magnética não-contrastadas. Esses órgãos apresentam um arranjo espacial consistente em imagens distintas, além de propriedades de aparência e anatômicas variáveis, o que vem ao encontro da proposta da representação por GER e da abordagem probabilística para o reconhecimento dos órgãos em novas imagens. / The purpose of this thesis was to propose a formalism for the problems of modeling and recognition of a structured object, or a system of structured objects, in images. A structured object is one that may be described in terms of its compound primitive elements and their inherent relations. For instance, an aircraft may be described in terms of the following primitives: right and left wings, fuselage, and cockpit. The relational aspect of structured objects leads these problems to solutions in structural pattern recognition, which describes patterns as primitives and relations. Nevertheless, the variability of primitive elements and of their relations is better modeled by traditional statistical pattern recognition methods. Because of the complementary capabilities of these approaches, the fusion of both has recently been pointed out as a trend in computer vision. To consider these sources of information, the methodology presented herein combines relational cues inherent to a structured object with statistical information learned from a set of object samples. A hybrid model of a structured object is represented by means of a statistical relational graph (SRG). The SRG is a prototype attributed relational graph (ARG) in which nodes represent primitive elements and arcs link nodes representing related primitives. Each node or arc is associated with attributes which are parameters of probability distributions that describe random variables representing primitive or relational attributes. Based on this representation, a probabilistic approach was proposed to tackle the problem of recognizing a structured object in an input image. The model SRG is interpreted as a random variable, whereas a labeling of the input image is considered a potential observation of the model. The recognition task was formulated as the optimization of an objective-function that is actually a probability measure to be maximized. The proposed approach was applied to the modeling of abdominal organs in non-contrasted magnetic resonance images. These organs present consistent spatial arrangement in distinct images, as well as varying appearance and anatomical properties, which meet the principle of the SRG representation and the associated probabilistic recognition scenario.

Mathematical modeling and simulations of a submerged renewable storage system integrated to a wind farm, chosen based on the geographical and wind conditions at the Baltic Sea, gives insight on the feasibility of the submerged renewable storage and an approximation of the payback period and profits that could be generated. Genetic Algorithms were used to obtain the optimal number of spheres for a certain depth, based on 2 objective functions I.e. Minimum Life Cycle Cost (LCC) and maximum reduction in wind curtailment. The new arrangement concept shows that the Initial Capital Cost (ICC) could be decreased by 25% to 60% depending upon the number of sphere employed. Based on the inputs considered in the study, the results prove that the submerged renewable storage system would be feasible, and the profits ranging from 15 Million Euro to 29 Million Euro can be achieved at the chosen location, towards the Swedish side of the Baltic sea. Although, in a real life scenario it is assumed that only up to half of the profits obtained in the results would be achievable. The results also show that, the Pump/Turbine with a high turbine efficiency and lower pump efficiency, generated better profits, compared to a Pump/Turbine running with a higher pump efficiency and lower turbine efficiency. An attempt to increase the round-trip efficiency by adding a multi stage submersible pump, resulted in additional ICC and LCC, which saw a decrease in profits.

Made available in DSpace on 2016-03-15T19:26:34Z (GMT). No. of bitstreams: 1 Edson Aparecido Dias.pdf: 907626 bytes, checksum: e4d9757a83fb8593062c00e7b381b5ee (MD5) Previous issue date: 2008-02-14 / Fundo Mackenzie de Pesquisa / There has been a lot of debate about Sustainability into the organizations recently. Some theorists state the organization should consider in their strategies elements that include the interest of the different stakeholders. This theoretical chain considers that economics, social and environmental systems are integrated, and so the organizations can t implement strategies which consider just one dimension. Other chain affirms the organizations should maximize the long term value and concentrate their efforts and investments on production and competitiveness, so they need to focus in only one objective, which is the long term value maximization of the firm, in this way, according this theory social welfare will be also maximized. In this complex context, sustainability indexes were created worldwide. These indexes in general, evaluate several dimensions and relations between the organization and society, environment and equity holders. In Brazil, was created in 2005 the sustainability index, ISE. Annually the BOVESPA announces to the market the new ISE Group, in which is included the companies that submit voluntarily, the answers to a wide survey about their sustainability practices. The inclusion on such group indicates the companies were evaluated according the rules of BOVESPA s sustainability rules. There are several discussions, if the organizations that make part of ISE group or similar, can capture abnormal returns to their shareholders, and if investments done in sustainability receive special attention by capital markets. This study investigates, using the event study methodology, if the announcement of being part of ISE group, creates value to shareholders. As event period was defined -15 to 120 days from announcement date, and in this period were created several event windows. In this research, the methodology is applied in two different ways: first; comparing the ISE group companies with a traditional Brazilian market index, the Ibovespa; second is the comparison with companies that have most part of their revenues from activities and products categorized in the same sector class (according BOVESPA) as the ISE ones, called in this study as control group. The results indicate the companies included in the ISE group do not capture Cumulated Abnormal Returns (CAR), when compared with the index market, in any event window. Anyhow, there were not found results that infer about lost of value, due the ISE announcement to the firm. By the other way, the results indicated that ISE companies can capture cumulated abnormal returns with statistically significant levels, when compared with the control group, in windows close to the announcement day. These results could be used to support manager s processes of decision, for establishing policies regarding sustainability of organizations. / O tema Sustentabilidade nas organizações tem sido bastante debatido, recentemente. Algumas correntes teóricas afirmam que, para garantir a perenidade, as organizações devem inserir na sua estratégia elementos que considerem o perfeito equilíbrio nas relações com diversos grupos de interesse. Esta linha teórica descreve que, os sistemas econômicos, sociais e ambientais estão integrados, e, portanto, as organizações não podem implementar estratégias que contemplem somente uma das dimensões. Outras correntes afirmam que, as organizações devem criar valor no longo prazo e concentrar seus esforços e investimentos na produção e na busca da competitividade e, para tanto, enfocando em um único objetivo: a maximização de valor da organização no longo prazo e, desta forma, haverá, conseqüentemente, ganhos e bem estar para toda sociedade. Neste contexto complexo, Índices de Sustentabilidade foram criados em escala global. Estes índices, em geral, avaliam várias dimensões das relações da organização com a sociedade, meio ambiente e com os provedores de capital para a empresa. No Brasil, especificamente no ano de 2005, foi criado o Índice de Sustentabilidade Empresarial (ISE). Anualmente, a BOVESPA anuncia ao mercado a nova carteira do ISE, na qual constam empresas que respondem, voluntariamente, um questionário amplo sobre as suas práticas de Sustentabilidade. A participação na carteira indica que estas empresas foram avaliadas de acordo com os critérios de Sustentabilidade da Bolsa. Existe muita discussão se as organizações que fazem parte deste indicador ou de indicadores similares trazem retornos anormais aos acionistas, e se, investimentos em práticas de sustentabilidade são bem vistos pelo mercado de capitais. O presente trabalho investigou, por meio da metodologia de estudo de evento, se a entrada de uma empresa na carteira do ISE, traz valor ao acionista. Foi estabelecido um período de evento de -15 até 120 dias do dia do anúncio e criado, dentro deste período, diversas janelas de evento. Nesta pesquisa, a metodologia foi aplicada de duas formas distintas: a primeira, por meio da comparação das empresas do ISE com um índice de bastante tradição no mercado de capitais brasileiro, o Ibovespa; e a segunda, fazendo-se a comparação com empresas que tem suas atividades principais dentro da mesma classificação setorial (de acordo com a BOVESPA) das empresas pertencentes à carteira do ISE, e que são chamadas, neste trabalho, de Grupo de Controle. Com relação aos resultados encontrados, quando comparadas com o índice de mercado as empresas participantes da carteira do ISE não demonstram retornos anormais acumulados positivos e, estatisticamente significantes, em nenhuma das janelas de evento do estudo. De qualquer forma, não foram encontrados, também, resultados robustos que levem a inferência de destruição de valor devido ao anúncio de entrada da empresa na carteira. Por outro lado, os resultados com Grupo de Controle indicam que, empresas que foram anunciadas como participantes do ISE, conseguem obter retornos anormais acumulados, estatisticamente significantes, em janelas próximas a data de anúncio. Sendo assim, estes resultados podem servir de apoio para os processos de tomada de decisão dos gestores das companhias, no estabelecimento de políticas relacionadas às práticas de Sustentabilidade nas organizações.