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High frequency Ethernet cabling analysis and optimizationOgundapo, Olusegun January 2016 (has links)
This thesis provides analytical and forensic tools for data cabling, with particular focus on Ethernet cabling to assist designers and those involved in deployments in analyzing cable performance and the reasons behind the actual performance obtained. The need for higher bandwidth to accommodate increasing demand for multimedia services and data centers network infrastructure led to the formation of IEEE P802.3bq to create standards for 40GBASE-T over twisted pair cables. The 40GBASE-T is expected to offer bandwidth of up to 2000MHz over a maximum channel length of 30m. The research investigated means of predicting key performance parameters in Ethernet cabling standardization using the 40GBASE-T as an example. The performance parameters prediction method provided is equally applicable to ongoing and future high data rate Ethernet cabling standardization such as the 2.5/5GBASE-T and 50/100GBASE-T. Another problem in the Ethernet networking world is the availability of counterfeit and non-standards compliant twisted pair cables in the market. The significant amount of communications cables in the market containing copper clad aluminum cable or other non-standards compliant conductors disguised as Category 6 cables can pose serious problems to companies’ networks, the contractors or the installers. This is in view of the growing demand for internet of things (IOT) services that makes it imperative to have a reliable Ethernet driven communication network to support the required infrastructure. This thesis therefore, provides techniques that can be used to evaluate cables key performance parameters using the Feature Selective Validation method and the Kolmogorov-Smirnov (KS) test. The technique can help engineers avoid subjective judgement and make objective decisions in the selection of cables. The research provided a technique that can be used to reverse engineer impedance profile from the return loss measurement of Ethernet cables using genetic algorithms. The method can be applied in situations where time domain tests are inaccessible or only simple (magnitude) tests in the frequency domain are available and there is the need for impedance profiles of cables to evaluate their performance or physical integrity before or after installation. The method can also be useful where only simple (magnitude) tests are the only historical data available for the cables and facilities for time domain reflectometry measurements are inaccessible. This research also presented a method of evaluating and predicting NEXT in unshielded twisted pair (UTP) using Category 6 cables as an example. The results obtained from the evaluation were used to provide crosstalk parameters for fast NEXT prediction in Category 6 (UTP) cables. The research used the measured NEXT of three Category 6 (UTP) cables from different manufacturers for evaluation and validation. The evaluation and modeling method can thus be useful to engineers investigating NEXT in the design of data communication systems.
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Från snack till verkstad : Om markverkstädernas dualistiska logikBergman, Marcus, Broström, Håkan January 2020 (has links)
Abstract In the year 2019 the vehicle workshops services returned to the Swedish Armed Forces. For six years they had been an integrated part of the Swedish Defence Materiel Administration and the business was set up in a corporate fashion. When returning to the Swedish Armed Forces the workshops will continue to use that corporate business model, and at the same time adjust to military setting and logic. Among other things, the workshops will be organized into military units, under the same conditions as all other parts of the Armed Forces. The purpose of this thesis is to examine and understand the meaning and consequences of the corporate and the military logic coexisting within the Vehicle Workshop Services units. A typology made specifically for this reason is used to depict the different configurations that occur when those two logic structures coexist. The study draws the conclusions that the dualistic relationship between the corporate and the military logic ends up in compromises that makes the goal and purpose of the organisation vague and the personnel involved experience a difference between how it is supposed to be functioning and how it actually does. Furthermore, the study states that the conditions for developing the Vehicle Workshop Services units into a strong and resilient organisation from a HR and symbolic perspective is less favourable. The Swedish Armed Forces need to address this actively to create a common understanding of the factors that are in play by all personnel involved in the matter. The study gives five hands on suggestions to mitigate those problems. Finally, some suggestions are given how to re-use the typology that was created for the study in other contexts.
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Enhancing numerical modelling efficiency for electromagnetic simulation of physical layer componentsSasse, Hugh Granville January 2010 (has links)
The purpose of this thesis is to present solutions to overcome several key difficulties that limit the application of numerical modelling in communication cable design and analysis. In particular, specific limiting factors are that simulations are time consuming, and the process of comparison requires skill and is poorly defined and understood. When much of the process of design consists of optimisation of performance within a well defined domain, the use of artificial intelligence techniques may reduce or remove the need for human interaction in the design process. The automation of human processes allows round-the-clock operation at a faster throughput. Achieving a speedup would permit greater exploration of the possible designs, improving understanding of the domain. This thesis presents work that relates to three facets of the efficiency of numerical modelling: minimizing simulation execution time, controlling optimization processes and quantifying comparisons of results. These topics are of interest because simulation times for most problems of interest run into tens of hours. The design process for most systems being modelled may be considered an optimisation process in so far as the design is improved based upon a comparison of the test results with a specification. Development of software to automate this process permits the improvements to continue outside working hours, and produces decisions unaffected by the psychological state of a human operator. Improved performance of simulation tools would facilitate exploration of more variations on a design, which would improve understanding of the problem domain, promoting a virtuous circle of design. The minimization of execution time was achieved through the development of a Parallel TLM Solver which did not use specialized hardware or a dedicated network. Its design was novel because it was intended to operate on a network of heterogeneous machines in a manner which was fault tolerant, and included a means to reduce vulnerability of simulated data without encryption. Optimisation processes were controlled by genetic algorithms and particle swarm optimisation which were novel applications in communication cable design. The work extended the range of cable parameters, reducing conductor diameters for twisted pair cables, and reducing optical coverage of screens for a given shielding effectiveness. Work on the comparison of results introduced ―Colour maps‖ as a way of displaying three scalar variables over a two-dimensional surface, and comparisons were quantified by extending 1D Feature Selective Validation (FSV) to two dimensions, using an ellipse shaped filter, in such a way that it could be extended to higher dimensions. In so doing, some problems with FSV were detected, and suggestions for overcoming these presented: such as the special case of zero valued DC signals. A re-description of Feature Selective Validation, using Jacobians and tensors is proposed, in order to facilitate its implementation in higher dimensional spaces.
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Adequação às condições brasileiras de modelo de caracterização para a categoria de impacto uso do solo. / Compliance to Brazilian conditions of a characterization mode for impact category land use.Chirinos Marroquín, Maritza 06 May 2013 (has links)
O uso intensivo de áreas do solo provoca alterações na sua qualidade, tornando-se necessária a criação de métodos de avaliação e monitoramento. A técnica de Avaliação do Ciclo de Vida (ACV) é uma importante ferramenta para o cálculo de impactos ambientais, relativos a um sistema de produto com fronteiras delimitadas, sendo o Uso do Solo uma das categorias de impacto avaliada. Na ACV este impacto é avaliado, a partir de fatores de caracterização, os quais utilizam indicadores que quantificam as consequências de modificações na estrutura do solo, levando em consideração a realidade e as características morfológicas de cada país ou região. Este estudo tem como objetivo apresentar adequações relacionadas às condições brasileiras do modelo para a caracterização de impactos provocados pelo uso do solo, a partir da adaptação de fatores de caracterização. De acordo com a pesquisa bibliográfica acerca dos métodos de avaliação do uso do solo na ACV, dois grupos são avaliados a Biodiversidade e as Funções de Suporte de Vida (FSV). Neste estudo foram identificados diferentes métodos que avaliam os impactos nas FSV e a partir de alguns critérios adotados foram posteriormente submetidos a uma análise, a fim de se determinar o método de maior relevância para as condições brasileiras. O método escolhido utiliza como indicador a Matéria Orgânica do Solo (MOS), porém devido à ausência de dados em algumas regiões, podem ser utilizados valores de Carbono Orgânico do Solo (COS), componente essencial da MOS. Os valores para o COS no estado natural foram atribuídos segundo dados de literatura para o bioma Amazônia, os quais foram posteriormente adaptados para se obter o COS para os tipos de uso de solo considerados neste estudo, segundo a realidade brasileira. / The intensive use of land areas cause changes in its quality, making it necessary to create methods for assessing and monitoring. The technique of Life Cycle Assessment (LCA) is an important tool for the calculation of environmental impacts related to a product system with defined borders, and the Land Use category of impact assessed. In this LCA impacts are assessed from factors characterization using indicators that quantify the effects of changes in soil structure, taking into account the reality and the morphological characteristics of each country or region. This study aims to present adjustments related to the Brazilian model for characterizing impacts caused by land use, based on the calculation of characterization factors. In accordance with the literature of the LCA methods, two groups contribute to this category Biodiversity and Life Support Functions (FSV). In this study were discussed and evaluated different methods to calculate (FSV), from some criteria adopted, these were subjected to a comparative analysis, to the method of greatest relevance to Brazilian conditions. The method chosen to use as an indicator of Soil Organic Matter (SOM), but due to lack of data in some regions, can be used values of Soil Organic Carbon (COS) essential component of SOM. The values for COS in the natural state were assigned according to the literature data of the Amazon biome, which were adapted to obtain the COS for the types of land use considered in this study according to the Brazilian reality.
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Adequação às condições brasileiras de modelo de caracterização para a categoria de impacto uso do solo. / Compliance to Brazilian conditions of a characterization mode for impact category land use.Maritza Chirinos Marroquín 06 May 2013 (has links)
O uso intensivo de áreas do solo provoca alterações na sua qualidade, tornando-se necessária a criação de métodos de avaliação e monitoramento. A técnica de Avaliação do Ciclo de Vida (ACV) é uma importante ferramenta para o cálculo de impactos ambientais, relativos a um sistema de produto com fronteiras delimitadas, sendo o Uso do Solo uma das categorias de impacto avaliada. Na ACV este impacto é avaliado, a partir de fatores de caracterização, os quais utilizam indicadores que quantificam as consequências de modificações na estrutura do solo, levando em consideração a realidade e as características morfológicas de cada país ou região. Este estudo tem como objetivo apresentar adequações relacionadas às condições brasileiras do modelo para a caracterização de impactos provocados pelo uso do solo, a partir da adaptação de fatores de caracterização. De acordo com a pesquisa bibliográfica acerca dos métodos de avaliação do uso do solo na ACV, dois grupos são avaliados a Biodiversidade e as Funções de Suporte de Vida (FSV). Neste estudo foram identificados diferentes métodos que avaliam os impactos nas FSV e a partir de alguns critérios adotados foram posteriormente submetidos a uma análise, a fim de se determinar o método de maior relevância para as condições brasileiras. O método escolhido utiliza como indicador a Matéria Orgânica do Solo (MOS), porém devido à ausência de dados em algumas regiões, podem ser utilizados valores de Carbono Orgânico do Solo (COS), componente essencial da MOS. Os valores para o COS no estado natural foram atribuídos segundo dados de literatura para o bioma Amazônia, os quais foram posteriormente adaptados para se obter o COS para os tipos de uso de solo considerados neste estudo, segundo a realidade brasileira. / The intensive use of land areas cause changes in its quality, making it necessary to create methods for assessing and monitoring. The technique of Life Cycle Assessment (LCA) is an important tool for the calculation of environmental impacts related to a product system with defined borders, and the Land Use category of impact assessed. In this LCA impacts are assessed from factors characterization using indicators that quantify the effects of changes in soil structure, taking into account the reality and the morphological characteristics of each country or region. This study aims to present adjustments related to the Brazilian model for characterizing impacts caused by land use, based on the calculation of characterization factors. In accordance with the literature of the LCA methods, two groups contribute to this category Biodiversity and Life Support Functions (FSV). In this study were discussed and evaluated different methods to calculate (FSV), from some criteria adopted, these were subjected to a comparative analysis, to the method of greatest relevance to Brazilian conditions. The method chosen to use as an indicator of Soil Organic Matter (SOM), but due to lack of data in some regions, can be used values of Soil Organic Carbon (COS) essential component of SOM. The values for COS in the natural state were assigned according to the literature data of the Amazon biome, which were adapted to obtain the COS for the types of land use considered in this study according to the Brazilian reality.
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„Sprecht Deutsch, bitte!“ : Die Fremdsprachenverwendung unter schwedischen SchülerInnen in Bezug auf ihre Fremdsprachenverwendungsangst und Fremdsprachenverwendungsfertigkeiten / "Sprecht Deutsch, bitte!" : Foreign language use among Swedish upper secondary school students with regard to their foreign language speaking anxiety and foreign language speaking skillsRudberg, Josef January 2017 (has links)
Previous studies that have utilized the Foreign Language Speaking Anxiety Scale (FLSAS) have performed their studies with the assumption that Foreign Language Speaking Anxiety is negatively correlated with oral skills, i.e. as anxiety increases, speaking skills decrease. In order to confirm this assumption, this study included a survey, the purpose of which is to measure three factors, in order to verify the possibility of other factors playing possibly bigger roles, among upper secondary school students in Sweden: the frequency of language use, their anxiety levels, and foreign language speaking skills. In order to be able to discuss the data thoroughly, this study includes theories regarding motivation, Self-Determination Theory, and Willingness to Communicate (WTC). The data showed that as the anxiety of the students increased, their language speaking skills decreased, i.e. a negative correlation was discovered. However, their frequency of foreign language use remained virtually the same, regardless of their anxiety levels, i.e. no strong correlation was discovered here. Lastly, the language skills of the students showed a weak positive correlation with their language use, i.e. the more they spoke, the higher their oral skills were. Therefore, the results of this study confirm previous studies claiming that foreign language speaking competence has a strong negative correlation with foreign language speaking anxiety.
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