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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
231

Desambiguação lexical de sentidos para o português por meio de uma abordagem multilíngue mono e multidocumento / Word Sense Disambiguation for portuguese through multilingual mono and multi-document

Fernando Antônio Asevêdo Nóbrega 28 May 2013 (has links)
A ambiguidade lexical é considerada uma das principais barreiras para melhoria de aplicações do Processamento de Língua Natural (PLN). Neste contexto, tem-se a área de Desambiguação Lexical de Sentido (DLS), cujo objetivo é desenvolver e avaliar métodos que determinem o sentido correto de uma palavra em um determinado contexto por meio de um conjunto finito de possíveis significados. A DLS é empregada, principalmente, no intuito de prover recursos e ferramentas para diminuir problemas de ambiguidade e, consequentemente, contribuir para melhorias de resultados em outras áreas do PLN. Para o Português do Brasil, pouco se tem pesquisado nesta área, havendo alguns trabalhos bem específicos de domínio. Outro fator importante é que diversas áreas do PLN engajam-se no cenário multidocumento, onde a computação é efetuada sobre uma coleção de textos, todavia, não há relato de trabalhos de DLS direcionados a este cenário, tampouco experimentos de desambiguação neste domínio. Portanto, neste trabalho de mestrado, objetivou-se o desenvolvimento de métodos de DLS de domínio geral voltado à língua Portuguesa do Brasil e o desenvolvimento de algoritmos de desambiguação que façam uso de informações multidocumento, bem como a experimentação e avaliação destes no cenário multidocumento. Para tanto, a fim de subsidiar experimentos, desenvolvimento e avaliação deste projeto, anotou-se manualmente o córpus CSTNews, caracterizado como um córpus multidocumento, utilizando a WordNet de Princeton como repositório de sentidos, que organiza os significados por meio de conjuntos de sinônimos ( synsets) e relações linguísticas entre estes. Foram desenvolvidos quatro métodos de DLS e algumas variações, sendo: um método heurístico (para aferir valores de baseline); variações do algoritmo de Lesk (1986); adaptação do algoritmo de Mihalcea and Moldovan (1999); e uma variação do método de Lesk para o cenário multidocumento. Foram realizados três experimentos para avaliação dos métodos, cujos objetivos foram: determinar o desempenho geral dos algoritmos em todo o córpus; avaliar a qualidade de desambiguação de palavras mais ambíguas no córpus; e verificar o ganho de qualidade da desambiguação ao empregar informação multidocumento. Após estes experimentos, pôde-se observar que o método heurístico apresenta um melhor resultado geral. Contudo, é importante ressaltar que a maioria das palavras anotadas no córpus tiveram apenas um synset, que, normalmente, era o mais frequente, o que, consequentemente, apresenta um cenário mais propício ao método heurístico. Outro fato importante foi que, neste cenário, a diferença de desempenho entre o método de DLS multidocumento e o heurístico é estatisticamente irrelevante. Já para a desambiguação de palavras mais ambíguas, o método heurístico foi inferior, evidenciando que, para a desambiguação de palavras mais ambíguas, são necessários métodos mais sofisticados de DLS. Por fim, verificou-se que a utilização de informação multidocumento auxilia o processo de desambiguação. As contribuições deste trabalho podem ser agrupadas entre teóricas e técnicas. Nas teóricas, tem-se a investigação e análises da DLS no cenário multidocumento. Entre as contribuições técnicas, foram desenvolvidos métodos de DLS, um córpus anotado e uma ferramenta de anotação direcionados à língua Portuguesa do Brasil, que podem avançar as pesquisas em DLS para o idioma / The lexical ambiguity is considered one of the main barries to improving applications of Natural Language Processing (NLP). In this context, it has benn the area of Word Sense Disambiguation (WSD), whose goal is to develop and evaluate methods to determine the correct sense of a word in a give context by a nite set of possible meanings. The DLS is used mainly in order to provide resources and tools to reduce problems of ambiguity and thus contribute to improved results in other areas of NLP. In the Portuguese of Brazil, little has been researched in this area, with some work and specic domain. Another important factor is that many areas of NLP commit themselves in multidocument scenario, where the computation is performed on a collection of texts, however, there is no report of WSD work directed to this scenario, either disambiguation experiments in this eld. Therefore, this master thesis aimed to develop methods of WSD general domain facing the Portuguese language in Brazil and the development of algorithms that make use of disambiguation multidocument informations, as well as experimentation and evaluation of the multidocument scenario. Therefore, in order to support experiments, development and evaluation of this project, the corpus CSTNews with 50 document collections, was manually annotated by means of synsets of the WordNet Princeton. Four methods were developed: A heuristic method (to measure values fo baseline); variations of the Lesk (1986) algorithm; a adaptation of the Mihalcea and Moldovan (1999) algorithm; and a variation of the Lesk method for multidocument scenario. Three experiments were conducted to evaluate the methods, whose objectives were to determine the general performance algorithms across the corpus; evaluate the quality of disambiguation of most ambiguous words in the corpus, and check the gain quality of disambiguation by employing information multidocumento. After these experiments, it was observed that the heuristic method presents a better overall result. However, it is important to note that most of the words in the annotated corpus had only one synset, which usually was the most frequent, which, in turn, presents a scenario more conducive to the heuristic method. Another important fact was that in this scenario, the performance dierence between the heuristic method and multidocument algorithm was statistically irrelevant. As for the disambiguation of most ambiguous words, the heuristic method was lower, indicating that, for the disambiguation of ambiguous words, more sophisticated WSD methods are needed. Finally, it has been found that the use of multidocument information assists the disambiguation process. The contributions of this work can be divided between theoretical and technical. In theory, there is the research and analysis of WSD in multidocument scenario. Among the techniques contributions, WSD methods have been developed an annotated corpus and annotation tool targeted to the Portuguese language in Brazil that can advance research in WSD for the language
232

Efficiency of a Scenario Editor for Connectivity Between Virtual Military Combat Systems / Effektivitet av en scenarioredigerare för kontakt mellan virtuella militära stridsledningssystem

Mellberg, Tobias, Vilhelmsson, Liam January 2019 (has links)
Today people spend a lot of time trying to complete software-related assignments. Poorly designed software can waste both time and resources needed to complete a task. It is therefore important to have efficient ways to complete these tasks. The Swedish Defence Research Agency, also known as FOI has developed software to calculate whether simulated units in the terrain have radio contact or not. In the current approach the employees manu-ally writes scenario files which contains information about the contact. However, these sce-nario files quickly become very large and difficult to work with. A possible solution to this issue is creating a scenario editor where the user can use an interface to create information about the contact between the units. This thesis suggests a Military Combat System Scenario Editor (MCSSE) which is compared to writing scenario files manually. The comparison is made by first performing a number of tasks with both applications. The applications thereafter evaluated using a metric called Minimal Actions Performed (MAP) which is defined for this comparison. The thesis also suggests appropriate tasks for evaluating the applications using an iterative method consisting of meetings with an expert with specified questions. By using the MAP metric, the application can be evaluated and the results show that the MCSSE is on average 66% more efficient than the current approach.
233

Modélisation des impacts énergie/carbone de changements de modes de vie. Une prospective macro-micro fondée sur les emplois du temps. / Modelling energy demand and CO2 emissions associated with changes in household consumption patterns. A macro-micro long-term analysis based on time use.

De Lauretis, Simona 06 July 2017 (has links)
Les ménages sont responsables d’une part significative des consommations d’énergie et des émissions de CO2, en particulier si l’on tient compte des consommations d’énergie et des émissions indirectes liées aux processus de production des biens et services consommés. Plusieurs travaux scientifiques et recommandations d’organisations gouvernementales et d’associations non-gouvernementales soulignent que des modifications des modes de consommations seront sans doute nécessaires pour atteindre les objectifs climatiques fixés aujourd’hui. Notre thèse propose une méthode d’analyse prospective de changements de mode de vie, qui permet d’en estimer les impacts macro-économiques ainsi que ceux sur les consommations d’énergie et les émissions de CO2, tout en tenant compte de l'hétérogénéité des ménages en matière de comportements et de consommations d'énergie. Notre méthode explore les modes de consommation des ménages de manière fine, en prenant en considération le lien entre emplois du temps et consommations. En effet, les choix de consommation sont soumis non seulement à des contraintes de budget, mais également à des contraintes qui dérivent du temps à disposition et qui ne sont jamais prises en compte dans la prospective macro- économique. Nous construisons une base de données détaillant emplois du temps, dépenses et consommations d’énergie des ménages français et nous l’articulons à un modèle de prospective économique énergie-émissions par un processus de repondération itératif. Nous illustrons la portée de cet outil à travers l’analyse de trois scénarios, centrés respectivement sur la diffusion de nouvelles formes de mobilité (covoiturage et autopartage), la généralisation des achats en ligne et le retour vers le faire soi-même en matière d'alimentation. Pour les trois scénarios nous observons des réductions des consommations d’énergie et des émissions de CO2. Par exemple, les émissions totales diminuent de 2,3% en 2050 dans le scénario sur la mobilité. / Household energy consumption represents a significant share of final energy use, especially when both direct and embodied energy are taken into account. Several academic studies, as well as the recommendations of the United Nations and of non-governmental organisations, suggest that a shift in consumption patterns will be necessary to achieve sustainable development. The aim of our research is to analyse long-term scenarios of changes in lifestyle. We propose a methodology that allows to analyse the macro-economic impacts of these changes, as well as the impacts on energy use and CO2 emissions, while taking into account the heterogeneity of behaviours and energy consumptions among households. Consumption choices do not derive solely from monetary considerations but they are influenced by several factors. One binding constraint, never taken into account in macro-economic energy modelling, is the available time. For this reason, our analysis considers time use data in addition to expenditure and energy use data. We build a data base that combines time use, expenditure and energy consumption data for French households, which provides detailed information about household consumption patterns. Then, for scenario analyses, we link the data base with an Energy-EconomyEmissions model, using an iteration process based on a reweighting technique. We illustrate the methodology by exploring three areas of change in consumption patterns: cooking habits, ecommerce and shared transport (carpooling and car sharing). We obtain CO2 emissions reductions in all scenarios. As an example, emissions decrease by 2.3% by 2050 in the scenario focusing on transport.
234

Gestion avancée du Plutonium en REP Complémentarité des cycles thorium et uranium / Advanced plutonium management in PWR, complementarity of thorium and uranium cycles

Ernoult, Marc 21 November 2014 (has links)
Dans le but d'étudier les possibilités de gestion avancée du plutonium dans les réacteurs actuels, 8 stratégies de multi-recyclage du plutonium dans des REP sont étudiées. Suite à des études à l'équilibre, il a été montré que, en utilisant des assemblages homogènes, l'utilisation du thorium ne permet pas de réduire les inventaires de plutonium en cycle à l'équilibre ni la production d'américium. En répartissant les différents types de combustibles au sein d'un même assemblage, certaines stratégies thoriées permettent cependant d'obtenir des inventaires et des productions d'américium inférieur aux meilleures stratégies utilisant uniquement le cycle uranium. Cependant dans tous les cas, le faible taux de conversion des combustibles thoriés en REP conduit à l'impossibilité de faire baisser la consommation de ressources de plus de quelques pour-cent par rapport aux stratégies sans thorium. Afin d'étudier la transition, une participation active au développement du code de scénario CLASS a eu lieu. Elle a aboutie à la simulation de deux scénarios parmi ceux étudiés à l'équilibre avec CLASS. Ces simulations ont montrées des écarts avec les scénarios simulés précédemment. Les causes majeures de ces écarts ont été identifiées et quantifiées. / In order to study the possibility of advanced management of plutonium in existing reactors, 8 strategies for plutonium multi-recycling in PWRs are studied. Following equilibrium studies, it was shown that, by using homogeneous assemblies, the use of thorium cannot reduce the plutonium inventory of equilibrium cycle or production of americium. By distributing the different fuel types within the same assembly, some thoriated strategies allow however lower inventories and lower production americium best strategies using only the uranium cycle. However, in all cases, low fuel conversion theories in PWRs makes it impossible to lower resource consumption more than a few percent compared to strategies without thorium. To study the transition, active participation in development of the scenario code CLASS has been taken. It led to the two simulation scenarios among those studied in equilibrium with CLASS. These simulations have shown discrepancies with previously simulated scenarios. The major causes of these differences were identified and quantified.
235

Cluster analysis for forest and wood-processing industry sector development in Ethiopia

Tolera, Busha Teshome 01 December 2021 (has links)
The majority of the people in sub-Saharan Africa depend on natural and planted forests for subsistence use and income generation. Despite this, the status of forests and wood-processing industries and their multiple uses are poorly understood. In Ethiopia information on the status and contribution of the forest and wood-processing industries to economic development is scanty and fragmented. The study was designed to contribute to filling this gap by analysing the status of the forest resource, assessing the contribution of the forest and wood-processing industries to the national economy with emphasis on the cost structure, and identifying innovations in the wood-processing industries. The study was further developed scenarios to upgrade wood product supply in Ethiopia. The study focuses on the macro-level analysis complementing same with micro-level data that looks into wood-processing industries of the country. Cluster analysis and innovation systems are frameworks employed in collecting and analysing both primary and secondary data. Secondary data on forests in Ethiopia are generally lacking. The analysis was conducted using data from 2010 as the reference year. The year 2010 was chosen as it is the only year for which the most recent aggregated social accounting matrix table for Ethiopia was available. Primary data were collected from key informant interviews and by undertaking survey in selected wood processing industries. A consultation workshop was conducted with different stakeholders to develop alternative scenarios regarding options to meet national wood demands and to share and validate findings of the study. The quantitative data were analysed using descriptive statistics such as frequencies, means, and percentages. The qualitative information gathered was summarised, analysed, and interpreted in the form of narratives. The study covered the six major forest types in Ethiopia from which significant wood volume is collected. The volume of wood reported to be harvested from these forests exceeded the annual incremental yield, indicating widening of the gap between supply and demand over time. The estimated wood product gap was 39 million m³ in 2013. The expanding gap between supply and demand of wood products in Ethiopia led to rapid increment in the volume of wood products imported, from 17,750 m3 in 1997 to 128,914 m3 in 2017. The estimated economic contribution of the forest sector and wood-processing industries in 2010 to the GDP was 4.2% and 0.036%, respectively. Regarding labour composition, both forest and wood-processing industries are dependent on unskilled labour with the respective share of 44.6% and 40.4%. The results also show that the forest sector has a strong linkage with the domestic economy, with 99.95% share as the input source. Wood-processing industries are mainly dependent on imported raw materials with a share of 51.6% of inputs. If the multiplier effect of the forest sector is considered, its contribution to the GDP could increase by up to 72%. Thus, a unit increment in the forest and wood-processing industries will have a multiplier effect on household income by 1.35 and 0.43, respectively. It is the non-poor households in small urban settlements that would benefit more in both cases. The strong forward and backward linkages of the forest sector indicated the potential of forests to support the national economic development as compared to the wood processing industries that showed a weak backward linkage due to its dependency on imported raw material, high price of round wood from domestic markets, and underdevelopment of plantation forestry in Ethiopia. Production factors related and supporting sectors, and government supports were found to be the constraining factors that affect the competitiveness of studied wood processing industries. The demand for wood products has a positive influence on the competitiveness of wood processing industries. The cost structure analysis showed variations with the types of wood processing industries. Raw material was the main input cost for the Ethiopian Chip Wood and Furniture Company (43%), and Ethiopian Plywood Enterprise (51%), while the overhead cost was the main costs (76%) for the Arsi Negelle sawmill. Imported chemicals raised the cost of the studied panel industries. However, the Arsi Negelle sawmill incurs a relatively low cost for raw material. This is because the Arsi Negelle sawmill uses its own plantations nearby the industry, which reduces the transportation cost. The analysis of sectoral innovation system actors indicated weak implementation of the expected roles. They are also poorly networked with the wood-processing industries. The identified constraining factors for innovation activities also include out-dated machines, lack of incentives for the employees, limited skilled manpower, insufficient financial resources, and inadequacy in research and development. Innovation activities identified are processing and marketing innovations in Maichew particleboard and Mitike sawmill, respectively. The introduction of innovation contributed to increasing the number of customers, revenue generated, jobs created, and volume of products sold. More innovation activities were identified in privately owned than in state-owned factories. Three scenarios were developed in identifying and examining prevailing options to reduce the gap between supply and demand of wood products in the country. These are business-as-usual, the government plan, and the independent experts’ opinion scenarios. The business-as-usual scenario assumes that no major change will happen in the forest sector. This scenario assumed that the main problems remain the same and the supply-demand gap will widen using the current trend. The government plan scenario assumes that the country will build a climate-resilient green economy by 2030 as envisages in its CRGE strategy issued in 2011. In this scenario, significant investment is expected to reduce the gap. Official records show that between 2016 and 2019, the production of wood products increased and reached 8,703,439 m³ and revenue collection grew to 9,352,816 USD. Despite this, supply-demand gap continued to widen, resulting in increased importation of various wood products. The independent experts’ scenario was developed based on the assessment of the unsustainability of the first scenario and the ambitious and unrealistic goals of the second scenario. The scenario of experts considered factors that will improve or undermine production and productivity of forests and meet demands for biomass fuel, industrial wood, and small diameter poles. As per this scenario, sustainable wood product supply is expected to increase and imports to be reduced by 20% in the coming decade. Scenarios developed provided insights for policymakers and suggested the need for strategic planning for developing forest resources and wood industries in the country. Measures to transform the forest sector and wood processing industries of Ethiopia need to consider their contribution and multiplier effects to the national economy. Regarding theoretical aspects, the thesis demonstrated there are some limitations associated with Social Accounting Matrix data quality, which limits the ability to interpret the forward and backward linkages. Yet, the analysis revealed that there is weak cooperation among innovation systems actors to work together. The study hopes to form the basis for further studies and proposed areas for future research to improve the economic contribution of forests and wood processing industries to the national economy.:1 Introduction 2 Theoretical concepts and analytical framework 3 Methodological framework 4 Overview of the forestry sector and its contribution to the national economy 5 Competitiveness and cost structure analysis of wood-processing industries in Ethiopia 6 Innovation system and innovations in the wood-processing industries of Ethiopia 7 Scenario development to upgrade the wood product supply in Ethiopia 8 Synthesis and conclusion References
236

Simulace a vyhodnocení scénářů nasazení služeb reálného času do sítí UMTS v prostředí Opnet Modeler / Simulation and evaluation of scenarios running real-time UMTS services in Opnet Modeler environment

Klimeš, Roman January 2009 (has links)
This work deals with the Universal Mobile Telecommunications System problems. It researches the parameters of influencing the UMTS Terrestrial Radio Access Network behaviour where is the Quality of Services support necessary. The aim of this master’s thesis is the simulation and evaluation of scenarios running real-time UMTS services in Opnet Modeler environment. In the first part is the short introduction to this technology problem. The requirements and the aims, the frequency plan, the network architecture and the Quality of Services support in UMTS are described. Creating the mobile network in the OPNET Modeler environment, configuration of the particular elements with the correct functionality and finally the parameters configuration for the Quality of Service at all workstations was the practical part of this work. At last phase was needed to compare the final statistics of the model without QoS support and the model with QoS support. I verified my knowledge in the OPNET Modeler program and the expected simulation results were confirmed. The final part of the thesis was creating the laboratory problem on the basis experience gained.
237

Modelování pohybu mobilní stanice v simulačním prostředí OPNET Modeler / Modelling the movement of mobile stations in the OPNET Modeler simulation environment

Kuběna, Pavel January 2013 (has links)
The main topic of this master´s thesis is a practical simulation of wireless mobile networks. For this purpose, the model simulating urban enviroment in which mobile nodes move according to desgined trajectories was created. The parameters of transmitted signal and impact of obstacles in the way of propagation were examined by the simulation. Number of obstacles and type of material of given obstacle was taken into consideration.
238

Effects of host plants, temperature regimes, and mating scenarios on the population dynamics of the cabbage whitefly Aleyrodes proletella L. (Hemiptera: Aleyrodidae)

Askoul, Khaldon 20 June 2017 (has links)
No description available.
239

A Scenario-Based evaluation of Game Architecture

AL Halbouni, Hadi, Hansen, Frank January 2020 (has links)
When developers or organizations need to develop a game, simulation or a similar project, they phase the question of whether or not to use a game engine as well as the question on which one to use. Are all game engines the same or does the architecture change and how is the game design different between various game engines? The objective of this thesis is to research these questions as well as giving a concrete understanding of the impact of picking one engine over the other and how each engine influences the way games are developed and answer some more specific questions regarding architecture and usability.  A project was designed with the goal of developing a game. This game was developed by two separate teams over a period of 6 weeks, using two different game engines. The development was split into separate iterations done simultaneously between the teams and questionnaires were filled in to gather data. The game engines used for projects had similarities but also things which were different. Each engine offered ways to speed up development by allowing the developer to reuse and distribute changes among objects to reduce work. The differences caused one engine’s code architecture to be more complex than the other while allowing a better code structure as well as adding more time to learn how the engine handles certain things such as collisions. In conclusion, there is an importance to properly evaluating different game engines depending on the project a developer or organization is creating, not evaluating this properly will impact development speed and project complexity. Even though each engine has their differences, there is no superior game engine as it all depends on the project being developed. The game developed for this project was only touching on certain areas related to 2D games.
240

Energy Modelling in Residential Houses: A Case Study of Single Family Houses in Bahir Dar City, Ethiopia

Ejigu, Netsanet Adgeh January 2016 (has links)
Several studies have been conducted and revealed that household is the major energy consumer sector in developing countries like Ethiopia. This study focuses on evaluation of the existing residential energy consumption and projection of the energy demand.   The energy consumption has been studied by conducting survey on 350 households using stratified random sampling technique. Then the analyzed data have been used to model the energy demand and to project the future energy consumption till 2030 using LEAP (Long Range Energy Alternative Planning) simulation software.   The model is done based upon baseline scenario and energy efficiency improvement scenario (mitigation scenario). The total energy consumption in Bahir dar in 2014 is nearly 330 Giga watt hour per year, and of this value about 83.8% is used for cooking and TV, lighting, refrigerator, and water heater consume 7%, 4.5%, 3.5%, 1%  of the total energy and remaining 0.2% is consumed for other auxiliary appliances. The projection of the energy consumption in 2030 will be more 450 Giga-watt-hour with business as usual scenario compared to just less than 350 Giga-watt-hour with mitigation scenario. As the result of the poor consumption efficiency, households that use traditional biomass tend to have more primary energy intensity than household that use electricity. The consumption of electricity is projecting rapidly while charcoal and firewood will still be the significant energy sources. The potential for energy saving is from improving the efficiency of stoves. Comparing with developed countries, for example Sweden, where the energy in dwellings is mostly used for space and water heating and the energy saving mostly target on improving wall insulations, the energy saving on Bahir dar is based mostly on cooking. The findings obtained in this shows options to improve household energy efficiency intervention planning and to enhance the effectiveness of policy interventions. Further studies could be done on modeling of other sectors.

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