This research program focused on the behaviour of low cycle fatigue (LCF) of wrinkled pipes, and was designed to develop the LCF life prediction models for the wrinkled pipes. It consisted of three phases of work, which are strip tests, full-scale pipe tests, and finite element analysis (FEA). In strip tests, 39 strip specimens were tested by a complete-reversed stroke-controlled method to investigate the effects of bend angle, bend radius, and stroke range on the low-cycle fatigue (LCF) life. Also, the LCF behaviour was explored by viewing the spectra of key variables and their corresponding hysteresis loops. The failure mechanism was discussed by examining the fracture surfaces. Two LCF life prediction models, life-based and deterioration rate-based, were developed and their prediction results were evaluated. In full-scale pipe tests, two specimens were tested according to a complicated loading procedure. The loading was a combination of axial load, bending moment, and internal pressure; and it consisted of monotonic loading stage and cyclic loading stage. Based on those two tests, the global and local behaviour were investigated, the failure mechanism was studied and the application of the developed LCF life prediction models was discussed. In FEA, three numerical models were developed and they were the strip model, the half-pipe model and the full-scale pipe model. In the strip model, the residual stresses and strains were analyzed and discussed. In the half-pipe model, the effects of pipe geometry, internal pressure, and global deformation on the wrinkle geometry were studied and discussed. In the full-scale pipe model, the full-scale pipe tests were simulated and both the global behaviour and local behaviour were discussed. From this research program, some important conclusions were obtained. The wrinkle geometry is found to be greatly related to the pipe geometry, internal pressure, and global deformation. The global deformation has become localized after the wrinkle is fully developed. The opening deformation cycle is more detrimental to wrinkled pipes than the closing deformation cycle. The test results also show that the seam weld governs the failure of wrinkled pipes if the pipes are subjected to cyclic axial deformation. The LCF life prediction models developed from this research program demonstrate good prediction capacity when they are applied to both strip tests and full-scale pipe tests. / Structural Engineering

As the demand for oil and gas resources increases pipeline construction pushes further into the Arctic and sub-Arctic regions. Consequently, these buried pipelines suffer much harsh environmental and complex loading conditions. Moreover, to increase the transporting efficiency, larger size pipes and higher operation pressure are used more frequently. Therefore, these conditions increase the risk of pipeline failure, especially local buckling (wrinkling) failure. To prevent the buried pipes from buckling failure, an automatic warning system for continuously monitoring pipeline buckling is needed. A method to achieve this purpose was studied and presented here. The research program is divided into three phases. In the first phase, a literature review has concluded that it is feasible to detect pipe wrinkling by monitoring the signatures of distributed strains and curvatures along a buried pipe and by using the distributed strain sensory systems in a structural health monitoring (SHM)system. Subsequently, the test results and the field strain distribution data were used to verify the viability of using distributed strain sensors for early detecting wrinkles in buried pipes. In the second phase, finite element (FE) models were developed and calibrated by the results of full-scale pipe buckling tests and then used to obtain the patterns (or signatures) of the strain distributions along pipes under combined loading. Based on the results of the parametric study, a SHM system is proposed. The system integrated the distributed strain sensing system (such as Brillouin scattering fiber-optic sensory system), numerical models (FE models), and damage detection models (artificial neural network (ANN)) into a reliable, real-time monitoring system. Thereby, a methodology of health monitoring of the buried pipe buckling was carried out. The last phase of the research focuses on the development of the damage detection models (DDM) in the SHM system. The effects of different parameters on the strain distribution patterns were studied by using a total of 74 FE models. The framework of the damage detection models was achieved mainly by four trained ANN protocols. The proposed damage detection model provides an accuracy of 90% in evaluating the health of the buried pipes during buckling and can reliably detect the onset of pipe wrinkling before the maximum strains accumulated on the monitored pipe reach 65% of the critical strain. / Structural Engineering

This study experimentally evaluated wheat straw slurry pipelines. Tests were conducted to determine the particle properties of the biomass mixed in water over time. The saturated particle density of 1,060kg/m3 was reached after 24 hours, while the saturated moisture contents of 78.5% and 79.5% were later reached for particle sizes of 1/8 and 3/4" respectively. A pipeline loop was redesigned to operate with 1/8, 1/4", and 3/4" straw particle slurries at up to 30% wet basis concentrations. The modifications allowed measurements of pressure loss through a length of pipe. These measurements which show the influences of drag reducing fibre suspension. Straw particles added to water lowered the pressure loss, by suppressing turbulence at lower concentrations or higher velocities. Additional straw further improved the result, until the maximum concentration was reached. High concentrations create plugs, increasing the pressure loss. Longer straw particles can further reduce losses, but have lower maximum concentrations. / Engineering Management

Ce travail est le résultat de recherches réalisées d’abord dans le cadre d’un programme d’archéologie préventive (2001-2004), puis d’une bourse doctorale à l’ULB entre 2004 et 2010 (Introduction générale). Les sites étudiés sont localisés dans la région de Kribi (côte camerounaise) et sont essentiellement composés de fosses, qui sont très certainement les vestiges des premières entités villageoises ayant habité la zone forestière atlantique du Cameroun vers ca. 3000BP (Chap. 1). La méthodologie adoptée varie sensiblement selon les deux programmes (Chap. 2). Le matériel analysé, surtout la céramique (Chap. 3, 4 et 5), a été récolté au cours des fouilles de sauvetage et programmées et a permis de définir une chronoséquence générale entre ca. 1000 BC et ca. AD 1000 (Chap. 6) qui comprend trois traditions céramiques : la Tradition de Bissiang (période de Transition Âge de la Pierre/Âge du Fer, Cal 1000-400 BC), le Groupe de Mpoengu (Âge du Fer I, Cal 400-50 BC) et la Tradition de Bidjoka (Âge du Fer II, Cal AD 0-1000). Cette dernière tradition est aussi contemporaine de l’apparition de sociétés complexes sur la côte méridionale camerounaise et ses environs, dont les sites se caractérisent surtout par la présence de ce qui semble être des structures funéraires, dans lesquelles on trouve de nombreux objets en fer (parures, armes, etc.) disposés de manière particulière et généralement associés à de poteries carénées décorées. Une étude comparative de la chronoséquence de la zone côtière a été faite avec celles déjà établies pour les zones avoisinantes, notamment au centre du Cameroun et dans les pays voisins (Chap. 7). Ce rapprochement a permis de conclure, entre autres, à une parenté culturelle entre la Tradition de Bissiang et celle d’Obobogo identifiée dans la région de Yaoundé (zone de forêt mixte). Enfin, l’ensemble des études comparatives a aussi conduit à faire quelques spéculations sur le peuplement de l’Afrique Centrale forestière depuis environ 3000 BP (Conclusion générale).

Since the development of SoC is very fast, how to reduce the power consumption of SoC and improve the performance of SoC has become a very important issue. The power consumption of a system depends upon the hardware and software of a system. To overcome the issue of power consumption, the hardware circuit provides multi-voltage method to reduce task power consumption. On the other hand, the software tool decides the exact voltage for each task to minimize the total power consumption and finds a pipelined schedule of the periodic tasks to enhance the total throughput. In this thesis, a Tabu search is used to solve the voltage mapping and resource mapping problems of multi-voltage systems. This goal of this Tabu search is to find the solution with minimal power consumption for the multi-voltage system under the time constraints and resource constraints at the same time in the multi-voltage system to. Under the throughput constraints we use Tabu search to find solutions including the task¡¦s execution voltage and resource mapping, and then use list pipelined scheduling to schedule task and data communication and check their correctness. This method can reduce total power consumption. Experimental results show that our proposed algorithm can decide the resources mapping and pipeline in seconds, and it can reduce the power consumption efficiently.

Denna rapport är en reflekterande text över skapandet av en digital handbok för animatörer som är med och startar ett nytt spelprojekt. Handboken är ett verk som gjordes som examensarbete på Högskolan i Skövde vårterminen 2009. Rapporten beskriver processen bakom skapandet av handboken. Denna process innefattar praktiskt arbete på företaget Junebug AB i Malmö, en förberedande litteraturstudie av hur text skrivs på ett tydligt, pedagogiskt sätt, en ytterligare litteraturstudie av tidigare skrivna handböcker för animatörer, intervjuer med animatörer i branschen och på utbildningen och sammanställning av handboken. Den centrala frågeställningen var: Hur kan man i handboksform på bästa sätt förmedla hur en animationspipeline1 tas fram, underhålls/effektiviseras och dokumenteras? Målet med arbetet har varit att sammanställa en handbok som andra animatörer kan använda sig av. Syftet har varit att lära mig om en riktig arbetsmiljö i spelbranschen och förmedla detta i handboken. Ett sekundärt mål har varit att uppmana andra animatörer i spelbranschen och på utbildningen att bidra med sina erfarenheter, tips och råd genom intervjuer. Resultatet blev en digital handbok på Internet för animatörer som jobbar, eller snart ska börja jobba, med animation i spelbranschen.

In a typical orthogonal frequency division multiplexing (OFDM) broadband wireless communication system, a guard interval using cyclic prefix is inserted to avoid the inter-symbol interference and the inter-carrier interference. This guard interval is required to be at least equal to, or longer than the maximum channel delay spread. This method is very simple, but it reduces the transmission efficiency. This efficiency is very low in the communication systems, which inhibit a long channel delay spread with a small number of sub-carriers such as the IEEE 802.11a wireless LAN (WLAN). To increase the transmission efficiency, it is usual that a time domain equalizer (TEQ) is included in an OFDM system to shorten the effective channel impulse response within the guard interval. There are many TEQ algorithms developed for the low rate OFDM applications such as asymmetrical digital subscriber line (ADSL). The drawback of these algorithms is a high computational load. Most of the popular TEQ algorithms are not suitable for the IEEE 802.11a system, a high data rate wireless LAN based on the OFDM technique. In this thesis, a TEQ algorithm based on the minimum mean square error criterion is investigated for the high rate IEEE 802.11a system. This algorithm has a comparatively reduced computational complexity for practical use in the high data rate OFDM systems. In forming the model to design the TEQ, a reduced convolution matrix is exploited to lower the computational complexity. Mathematical analysis and simulation results are provided to show the validity and the advantages of the algorithm. In particular, it is shown that a high performance gain at a data rate of 54Mbps can be obtained with a moderate order of TEQ finite impulse response (FIR) filter. The algorithm is implemented in a field programmable gate array (FPGA). The characteristics and regularities between the elements in matrices are further exploited to reduce the hardware complexity in the matrix multiplication implementation. The optimum TEQ coefficients can be found in less than 4µs for the 7th order of the TEQ FIR filter. This time is the interval of an OFDM symbol in the IEEE 802.11a system. To compensate for the effective channel impulse response, a function block of 64-point radix-4 pipeline fast Fourier transform is implemented in FPGA to perform zero forcing equalization in frequency domain. The offsets between the hardware implementations and the mathematical calculations are provided and analyzed. The system performance loss introduced by the hardware implementation is also tested. Hardware implementation output and simulation results verify that the chips function properly and satisfy the requirements of the system running at a data rate of 54 Mbps.

This thesis aims to analyze the Turkish policy of being an energy hub. Within this context Turkey, as it is geographically very close to the two thirds of the world&#039 / s proven oil and natural gas reserves, has a very big advantage to manage its location and the purpose of this study is to discuss the measures taken to utilize this advantage. Therefore relative weakness of Turkey in comparison to the other actors like Russia, the USA or the EU and the strengths of the Turkish policy like the geopolitical advantage, the ethnic link between Turkey and the newly independent states of the Caspian and the already existing infrastructure for the transportation of oil and natural gas like Kirkuk-Yumurtalik Pipeline, Baku Tblisi Ceyhan Oil Pipeline, Ceyhan Terminal, and Baku Tblisi Erzurum Natural Gas Pipeline are discussed. With this respect, this study argues that, as a result of the existing and planned projects, Ceyhan&#039 / s claim to become a hub is a realistic objective and in addition to BTC and Kirkuk-Yumurtalik Pipeline, the realization of Samsun-Ceyhan Pipeline will increase Ceyhan&#039 / s potential as an energy hub.

In a typical orthogonal frequency division multiplexing (OFDM) broadband wireless communication system, a guard interval using cyclic prefix is inserted to avoid the inter-symbol interference and the inter-carrier interference. This guard interval is required to be at least equal to, or longer than the maximum channel delay spread. This method is very simple, but it reduces the transmission efficiency. This efficiency is very low in the communication systems, which inhibit a long channel delay spread with a small number of sub-carriers such as the IEEE 802.11a wireless LAN (WLAN). To increase the transmission efficiency, it is usual that a time domain equalizer (TEQ) is included in an OFDM system to shorten the effective channel impulse response within the guard interval. There are many TEQ algorithms developed for the low rate OFDM applications such as asymmetrical digital subscriber line (ADSL). The drawback of these algorithms is a high computational load. Most of the popular TEQ algorithms are not suitable for the IEEE 802.11a system, a high data rate wireless LAN based on the OFDM technique. In this thesis, a TEQ algorithm based on the minimum mean square error criterion is investigated for the high rate IEEE 802.11a system. This algorithm has a comparatively reduced computational complexity for practical use in the high data rate OFDM systems. In forming the model to design the TEQ, a reduced convolution matrix is exploited to lower the computational complexity. Mathematical analysis and simulation results are provided to show the validity and the advantages of the algorithm. In particular, it is shown that a high performance gain at a data rate of 54Mbps can be obtained with a moderate order of TEQ finite impulse response (FIR) filter. The algorithm is implemented in a field programmable gate array (FPGA). The characteristics and regularities between the elements in matrices are further exploited to reduce the hardware complexity in the matrix multiplication implementation. The optimum TEQ coefficients can be found in less than 4µs for the 7th order of the TEQ FIR filter. This time is the interval of an OFDM symbol in the IEEE 802.11a system. To compensate for the effective channel impulse response, a function block of 64-point radix-4 pipeline fast Fourier transform is implemented in FPGA to perform zero forcing equalization in frequency domain. The offsets between the hardware implementations and the mathematical calculations are provided and analyzed. The system performance loss introduced by the hardware implementation is also tested. Hardware implementation output and simulation results verify that the chips function properly and satisfy the requirements of the system running at a data rate of 54 Mbps.

En los últimos años, el diseño de procesadores de altas prestaciones ha progresado a lo largo de dos corrientes de investigación: incrementar la profundidad del pipeline para permitir mayores frecuencias de reloj, y ensanchar el pipeline para permitir la ejecución paralela de un mayor numero de instrucciones. Diseñar un procesador de altas prestaciones implica balancear todos los componentes del procesador para asegurar que el rendimiento global no esta limitado por ningún componente individual. Esto quiere decir que si dotamos al procesador de una unidad de ejecución mas rápida, hay que asegurarse de que podemos hacer fetch y decodificar instrucciones a una velocidad suficiente para mantener ocupada a esa unidad de ejecución.Esta tesis explora los retos presentados por el diseño de la unidad de fetch desde dos puntos de vista: el diseño de un software mas adecuado para las arquitecturas de fetch ya existente, y el diseño de un hardware adaptado a las características especiales del nuevo software que hemos generado.Nuestra aproximación al diseño de un suevo software ha sido la propuesta de un nuevo algoritmo de reordenación de código que no solo pretende mejorar el rendimiento de la cache de instrucciones, sino que al mismo tiempo pretende incrementar la anchura efectiva de la unidad de fetch. Usando información sobre el comportamiento del programa (profile data), encadenamos los bloques básicos del programa de forma que los saltos condicionales tendrán tendencia a ser no tomados, lo cual favorece la ejecución secuencial del código. Una vez hemos organizado los bloques básicos en estas trazas, mapeamos las diferentes trazas en memoria de forma que minimicen la cantidad de espacio requerida para el código realmente útil, y los conflictos en memoria de este código. Además de describir el algoritmo, hemos realizado un análisis en detalle del impacto de estas optimizaciones sobre los diferentes aspectos del rendimiento de la unidad de fetch: la latencia de memoria, la anchura efectiva de la unidad de fetch, y la capacidad de predicción del predictor de saltos.Basado en el análisis realizado sobre el comportamiento de los códigos optimizados, proponemos también una modificacion del mecanismo de la trace cache que pretende realizar un uso mas efectivo del escaso espacio de almacenaje disponible. Este mecanismo utiliza la trace cache únicamente para almacenar aquellas trazas que no podrían ser proporcionadas por la cache de instrucciones en un único ciclo.También basado en el conocimiento adquirido sobre el comportamiento de los códigos optimizados, proponemos un nuevo predictor de saltos que hace un uso extensivo de la misma información que se uso para reordenar el código, pero en este caso se usa para mejorar la precisión del predictor de saltos.Finalmente, proponemos una nueva arquitectura para la unidad de fetch del procesador basada en explotar las características especiales de los códigos optimizados. Nuestra arquitectura tiene un nivel de complejidad muy bajo, similar al de una arquitectura capaz de leer un único bloque básico por ciclo, pero ofrece un rendimiento muy superior, siendo comparable al de una trace cache, mucho mas costosa y compleja.