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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.
201

Avaliação objetiva e subjetiva de qualidade de vídeo via rede IP com variação de atraso. / Objective and subjective assessment of video quality over IP network with packet delay variation.

Coaquira Begazo, Dante 04 October 2012 (has links)
Atualmente existe uma grande variedade de serviços de telecomunicações focados na transmissão de voz, vídeo e dados através de redes complexas, embora, em muitos casos, o usuário final não seja atendido com um nível de qualidade aceitável. Neste trabalho, se avalia como o serviço de streaming de vídeo em uma rede com protocolo Internet (IP) pode ser afetado por uma condição adversa da rede, tal como a variação de atraso (jitter). São mostrados os resultados de avaliações objetivas e subjetivas de streaming de vídeo que indicam que a qualidade de vídeo é diretamente afetada por fatores de degradação da rede IP como a variação de atraso de pacotes. Além disso, se verifica que cenas de maior movimento também são mais afetadas pela variação de atraso. Para a realização dos testes, utiliza-se um cenário de emulação de rede isolado, no qual são parametrizadas diferentes condições de rede. Assim, no canal de transmissão são configurados diversos valores de variação de atraso, obtendo-se uma Base de Dados de vídeos com diferentes graus de degradação de qualidade. Estes vídeos são avaliados utilizando métodos subjetivos: Índice por Categorias Absolutas (ACR - Absolute Category Rating) e Índice por Categorias de Degradação (DCR - Degradation Category Rating) e métricas objetivas: Relação Sinal-Ruído de Pico (PSNR - Peak Signal to Noise Ratio), Índice de Similaridade Estrutural (SSIM - Structural Similarity Index) e Medição de Qualidade de Vídeo (VQM - Video Quality Metric). Com a finalidade de mostrar o desempenho das métricas objetivas em relação às subjetivas são empregados os coeficientes de correlação, além do erro de predição e quadrático médio. Adicionalmente, é importante destacar que a partir dos resultados obtidos são estabelecidos intervalos de valores de variação de atraso para os quais a qualidade do vídeo é considerada aceitável ou não para o usuário final. Finalmente, obtém-se uma Base de Dados de vídeos com diferentes graus de degradação da qualidade e que pode ser utilizada em futuras pesquisas. / Nowadays, there is a wide range of telecommunications services focused on the transmission of voice, video and data across complex networks, although, in many cases, the end user is not satisfied with an acceptable quality level. In this work it is assessed how the video streaming service over an IP network can be affected by adverse conditions on the network, such as packet delay variation (jitter). Results from objective and subjective video streaming assessments are shown and indicate that the video quality is directly affected by IP network degradation factors such as packet delay variation. Beyond that, it is also verified that scenes with great movement content are also more sensitive to packet delay variation. For experimental tests, a network emulation totally isolated is considered, for which different network conditions are parameterized. Then, to the transmission channel, different values of packet delay variation are configured and videos are assessed, using subjective metrics: Absolute Category Rating (ACR) and Degradation Category Rating (DCR), and objective metrics: Peak Signal to Noise Ratio (PSNR), Structural Similarity (SSIM) and Video Quality Metric (VQM). In order to show the performance of objective metrics in relation to subjective ones correlation coefficients are employed as well as the prediction error and the mean square error. Finally, it is important to note that, from the results obtained, it can be established a range of delay variation values in which the video quality is acceptable or not at the end user. Additionally, a Video Data Base is obtained with different degrees of quality degradation and which can be used for future researches.
202

The linguistic elements of Old Germanic metre : phonology, metrical theory, and the development of alliterative verse

Goering, Nelson January 2016 (has links)
I examine those linguistic features of Old English and Old Norse which serve as the basic elements for the metrical systems of those languages. I begin with a critical survey of recent work on Old English metrical theory in chapter 1, which suggests that the four-position and word-foot theories of metre are the most viable current frameworks. A further conclusion of this chapter is that stress is not, as is often claimed, a core element of the metre. In chapter 2, I reassess the phonological-metrical phenomenon of Kaluza's law, which I find to be much more regular and widely applicable within Bēowulf than has previously been recognized. I further argue that the law provides evidence that Old English phonological foot structure is based on a preference for precise bimoraism. In chapter 3, I examine the role of syllables in the Norse Eddic metre fornyrðislag, which supports a view of resolution and phonological feet similar to that found in Old English, though Norse prosody is much more tolerant of degenerate, light feet. I reconsider the other major Eddic metre, ljóðaháttr, in chapter 4, integrating the insights of Andreas Heusler and Geoffrey Russom to propose a new system of scansion for this notoriously recalcitrant verse form. This scansion provides important support for the word-foot theory, and suggests that linguistic elements larger than syllables or phonological feet play a crucial role in early Germanic verse. In the final chapter, I give a diachronic account of Germanic metre and relevant linguistic structures, arguing that the word-foot theory provides the best metrical framework for understanding the development of Germanic alliterative verse. This metrical system is linguistically supported by Germanic word structures and compounding rules, and interacts with bimoraic phonological feet, all of which have a long history in Proto- and pre-Germanic.
203

Avaliação objetiva e subjetiva de qualidade de vídeo via rede IP com variação de atraso. / Objective and subjective assessment of video quality over IP network with packet delay variation.

Dante Coaquira Begazo 04 October 2012 (has links)
Atualmente existe uma grande variedade de serviços de telecomunicações focados na transmissão de voz, vídeo e dados através de redes complexas, embora, em muitos casos, o usuário final não seja atendido com um nível de qualidade aceitável. Neste trabalho, se avalia como o serviço de streaming de vídeo em uma rede com protocolo Internet (IP) pode ser afetado por uma condição adversa da rede, tal como a variação de atraso (jitter). São mostrados os resultados de avaliações objetivas e subjetivas de streaming de vídeo que indicam que a qualidade de vídeo é diretamente afetada por fatores de degradação da rede IP como a variação de atraso de pacotes. Além disso, se verifica que cenas de maior movimento também são mais afetadas pela variação de atraso. Para a realização dos testes, utiliza-se um cenário de emulação de rede isolado, no qual são parametrizadas diferentes condições de rede. Assim, no canal de transmissão são configurados diversos valores de variação de atraso, obtendo-se uma Base de Dados de vídeos com diferentes graus de degradação de qualidade. Estes vídeos são avaliados utilizando métodos subjetivos: Índice por Categorias Absolutas (ACR - Absolute Category Rating) e Índice por Categorias de Degradação (DCR - Degradation Category Rating) e métricas objetivas: Relação Sinal-Ruído de Pico (PSNR - Peak Signal to Noise Ratio), Índice de Similaridade Estrutural (SSIM - Structural Similarity Index) e Medição de Qualidade de Vídeo (VQM - Video Quality Metric). Com a finalidade de mostrar o desempenho das métricas objetivas em relação às subjetivas são empregados os coeficientes de correlação, além do erro de predição e quadrático médio. Adicionalmente, é importante destacar que a partir dos resultados obtidos são estabelecidos intervalos de valores de variação de atraso para os quais a qualidade do vídeo é considerada aceitável ou não para o usuário final. Finalmente, obtém-se uma Base de Dados de vídeos com diferentes graus de degradação da qualidade e que pode ser utilizada em futuras pesquisas. / Nowadays, there is a wide range of telecommunications services focused on the transmission of voice, video and data across complex networks, although, in many cases, the end user is not satisfied with an acceptable quality level. In this work it is assessed how the video streaming service over an IP network can be affected by adverse conditions on the network, such as packet delay variation (jitter). Results from objective and subjective video streaming assessments are shown and indicate that the video quality is directly affected by IP network degradation factors such as packet delay variation. Beyond that, it is also verified that scenes with great movement content are also more sensitive to packet delay variation. For experimental tests, a network emulation totally isolated is considered, for which different network conditions are parameterized. Then, to the transmission channel, different values of packet delay variation are configured and videos are assessed, using subjective metrics: Absolute Category Rating (ACR) and Degradation Category Rating (DCR), and objective metrics: Peak Signal to Noise Ratio (PSNR), Structural Similarity (SSIM) and Video Quality Metric (VQM). In order to show the performance of objective metrics in relation to subjective ones correlation coefficients are employed as well as the prediction error and the mean square error. Finally, it is important to note that, from the results obtained, it can be established a range of delay variation values in which the video quality is acceptable or not at the end user. Additionally, a Video Data Base is obtained with different degrees of quality degradation and which can be used for future researches.
204

Sobre rigidez de métricas quasi-Einstein / On rigidity of quasi-Einstein metrics

Borges, Laena Furtado 03 March 2017 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2017-03-17T21:10:56Z No. of bitstreams: 2 Dissertação - Laena Furtado Borges - 2017.pdf: 2090414 bytes, checksum: afc3416e502ab5aedc5390b7986a9fcf (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-03-20T13:53:29Z (GMT) No. of bitstreams: 2 Dissertação - Laena Furtado Borges - 2017.pdf: 2090414 bytes, checksum: afc3416e502ab5aedc5390b7986a9fcf (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-03-20T13:53:29Z (GMT). No. of bitstreams: 2 Dissertação - Laena Furtado Borges - 2017.pdf: 2090414 bytes, checksum: afc3416e502ab5aedc5390b7986a9fcf (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-03-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work, we will present some concepts of quasi-Einstein metrics. From this, we will enunciate and demonstrate rigidity results for quasi-Einstein metrics until we have enough material to demonstrate a stiffness result for quasi-Einstein metrics of dimension two. Finally, we will give some concepts of Kähler metrics, prove a theorem and finally demonstrate a corollary that connects the main theorem of our work with Kähler metrics. / Nesse trabalho, apresentaremos alguns conceitos de métricas quasi-Einstein. A partir disso, enunciaremos e demonstraremos resultados de rigidez para métricas quasi-Einstein, até que tenhamos material suficiente para a demonstração de um resultado de rigidez para métricas quasi-Einstein em dimensão dois. Por fim, daremos alguns conceitos de métricas kähler, provaremos um teorema e por fim demonstraremos um corolário que conecta o teorema principal do nosso trabalho com as métricas Kähler.
205

Mapeamento de soja e milho com mineração de dados e imagens sintéticas landsat e modis / Mapping of soybean and corn with data mining and synthetic images Landsat and MODIS

Oldoni, Lucas Volochen 05 February 2018 (has links)
Submitted by Rosangela Silva (rosangela.silva3@unioeste.br) on 2018-06-04T17:12:56Z No. of bitstreams: 2 Lucas Oldoni.pdf: 9472745 bytes, checksum: 1b2c1a8ee59169fa471b43d27a762f6e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-06-04T17:12:56Z (GMT). No. of bitstreams: 2 Lucas Oldoni.pdf: 9472745 bytes, checksum: 1b2c1a8ee59169fa471b43d27a762f6e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-02-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Studies related to the monitoring of agricultural production play a decisive and strategic role in the economic planning of the country, due to the importance of agribusiness, as well as food safety. Orbital remote sensing is an effective alternative to perform agricultural crop monitoring due to its low cost, large scale and speed of data collection. However, most of the sensors with high spatial resolution are of low temporal resolution, and the ones with higher temporal resolution have low spatial resolution. Therefore, for the monitoring of agricultural crops with a higher spatial solution, cloud covering can be a limiting factor. Such problems can be circumvented by using a fusion of images of several sensors with different spatial and temporal characteristics, thus creating new images, also called synthetic images. Thus, the objective of the work was the mapping of areas sown with soybean and corn using space-temporal fusion, such as Landsat 8 and MODIS images. In the first part of the research, agricultural crops were separated from other targets. The generated classification served as input to one of the classification algorithms, the Flexta Spatiotemporal Data Fusion (FSDAF), in the second part of the research. In addition to this algorithm, both the Spatial and Temporal Adaptive Reflection Fusion Model (STARFM) and the Advanced and Temporal Spatial Adaptive Reflection Fusion Model (ESTARFM) were employed to generate images for the 2016/2017 summer crops. Then, 5 rating scenarios were created. In the 1st and 2nd scenarios, only the images from the Landsat 8 with no occurrence of clouds were considered. For the 3rd, 4th, and 5th were carried out using images generated by STARFM, ESTARFM and FSDAF. In the third scenario, the metric images of images, Landsat 8 and images of fusion algorithms were used, 4th as a summary of statistical metrics, and in the 5th one as phenological metrics of the temporal profile of the Enhanced Vegetation Index (EVI). The scenario using the EVI phenological metrics from images generated by FSDAF and STARFM yielded better results, with global accuracy of 93.11 and 91.33%, respectively. These results are statistically better than those obtained using only existing Landsat 8 images. Thus, the use of phenological metrics obtained from synthetic images are important alternatives for mapping soybean and corn crops. / Estudos referentes ao acompanhamento da produção agrícola têm um peso determinante e estratégico no planejamento econômico do país, devido à importância do agronegócio, e também para segurança alimentar. O sensoriamento remoto orbital é uma alternativa eficaz para realizar o monitoramento das culturas agrícolas, devido ao baixo custo, grande escala de abrangência e rapidez na coleta de dados. Porém, geralmente os sensores com alta resolução espacial possuem baixa resolução temporal, e os com alta resolução temporal possuem baixa resolução espacial. Assim, para se realizar o acompanhamento de culturas agrícolas com uma resolução espacial mais alta, a cobertura por nuvens pode ser um fator limitante. Estes problemas podem ser contornados com a utilização de fusão de imagens de diversos sensores com características temporais e espaciais diferentes, criando, assim, novas imagens, também chamadas de imagens sintéticas. Deste modo, o objetivo do trabalho foi realizar o mapeamento de áreas semeadas com soja e milho utilizando fusão espaço-temporal de imagens Landsat 8 e MODIS. Na primeira parte do trabalho, foram separadas culturas agrícolas de outros alvos. A classificação gerada serviu de entrada em um dos algoritmos de classificação, o Flexible Spatiotemporal Data Fusion (FSDAF), na segunda parte do trabalho. Nessa parte, além deste algoritmo, também foram utilizados os algoritmos Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) e Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model (ESTARFM) para gerar imagens nas safras de verão 2016/2017. Então, foram criados 5 cenários de classificação. Nos 1º e 2º foram considerados a utilização apenas das imagens espectrais das imagens Landsat 8 livres de nuvens. As 3º, 4º e 5º foram realizadas com as imagens geradas pelo STARFM, ESTARFM e FSDAF. No 3º cenário foram utilizadas as métricas espectrais das imagens Landsat 8 e as imagens espectrais gerados pelos algoritmos de fusão, no 4º foram considerados as métricas estatísticas e no 5º as métricas fenológicas extraídas do perfil temporal do Enhanced Vegetation Index (EVI). Os cenários que utilizaram métricas fenológicas do EVI a partir de imagens geradas pelo FSDAF e STARFM obtiveram melhores resultados, com exatidão global de 93,11 e 91,33%, respectivamente, resultados estes estatisticamente melhores que os obtidos apenas com as imagens Landsat 8 existentes. Assim, a utilização de métricas fenológicas obtidas de imagens sintéticas são importantes alternativas para o mapeamento de soja e milho.
206

UI Performance Comparison of Jetpack Compose and XML in Native Android Applications / UI-Prestanda jämförelse mellan Jetpack Compose och XML inom Nativa Android Applikationer

Noori, Zaed, Eriksson, Caesar January 2023 (has links)
This thesis explores the differences in UI performance between Jetpack Compose, a modern declarative UI toolkit, and traditional XML in the context of UI design for native Android applications. The aim is to provide developers with insights into the potential tradeoffs associated with each approach, particularly in terms of the end user experience. In order to achieve this, a series of benchmark tests were conducted on two prototype applications: one developed with XML and the other with Jetpack Compose, in order to evaluate the UI performance in various scenarios of real-world use cases. The data collected was subsequently analyzed and discussed, in order to evaluate which UI design approach delivers better performance for the end user. The test results indicate that Jetpack Compose and XML excel at different use cases. Jetpack Compose is demonstrated to have faster app startup time and rendering time for navigation and animation, whereas XML delivers smoother and faster rendering time when scrolling through a layout. Notably, Jetpack Compose has also shown an improvement in UI performance since previous works were conducted. / Den här studien utforskar skillnaden i användargränssnitt-prestanda mellan Jetpack Compose, ett modernt deklarativt användargränssnitt verktyg, och traditionell XML i kontexten av användargränssnitt design för nativa Android applikationer. Syftet är att förse utvecklare med insikter om de potentiella avvägningar som är förknippade med varje tillvägagångssätt, särskilt när det gäller slutanvändarupplevelsen. För att uppnå detta genomfördes en serie prestandatester på två prototyp applikationer: en utvecklad med XML och den andra med Jetpack Compose, för att utvärdera användargränssnitt-prestandan inom olika scenarier av verkliga användningsfall. Den insamlade datan analyserades och diskuterades sedan för att utvärdera vilken användargränssnitt-design metod som levererar bättre prestanda för slutanvändaren. Testresultaten indikerar att Jetpack Compose samt XML presterar bättre vid olika användningsfall. Jetpack Compose har visat sig ha snabbare applikations starttid och renderingstid för navigering och animering, medan XML ger smidigare och snabbare renderingstid vid skrollning genom en layout. Framför allt har Jetpack Compose dessutom visat en förbättring i användargränssnitt-prestanda sedan tidigare arbeten utfördes.
207

Challenges with Measuring Software Delivery Performance Metrics : A case study at a software organisation

Gebrewold, Yamo, Wirell, Johanna January 2023 (has links)
Online software businesses constantly face new challenges. Businesses are competing to deliver high-quality software solutions to their end users as quickly as possible. The performance of a software team in terms of software delivery needs to be measured to identify bottlenecks and understand what can be improved. This project is a case study of a software organisation that delivers online web solutions for a business. The organisation strives to follow a DevOps mindset and work data-driven by collecting data, learning from it and acting on the learnings. Our method to perform the case study was to study existing data collected by the organisation and conduct interviews with software professionals to get their insights about the software delivery performance of three software teams within the organisation. We focus on two metrics - deployment frequency and lead time for change - which measure the throughput of a software team and how often and fast it can deploy changes to production. Software organisations that adopt a DevOps approach are facing challenges with collecting data about their software delivery performance and learning from that data to improve their throughput. We aim to identify these challenges and discuss various problems that software organisations need to be aware of when measuring software delivery performance. We present the results from the interviews and collected metrics, analyse them and discuss them, as well as give suggestions on future research. We observe that there are multiple factors impacting software delivery performance and various challenges with measuring it accurately. This is related to the way of reporting data reliably and developing models to study and understand the collected data.
208

APPROCHE INTELLIGENTE À BASE DE RAISONNEMENT À PARTIR DE CAS POUR LE DIAGNOSTIC EN LIGNE DES SYSTÈMES AUTOMATISÉS DE PRODUCTION / Intelligent case based reasoning approach for online diagnosis of automated production systems

Ben Rabah, Nourhène 14 December 2018 (has links)
Les systèmes automatisés de production (SAP) représentent une classe importante des systèmes industriels qui sont de plus en plus complexes vue le grand nombre d’interaction et d’interconnexion entre leurs différents composants. En conséquence, ils sont plus sensibles aux dysfonctionnements dont les conséquences peuvent être importantes en termes de productivité, de sécurité et de qualité de production. Un défi majeur est alors de développer une approche intelligente qui peut être utilisée pour le diagnostic de ces systèmes afin de garantir leurs suretés de fonctionnement. Dans le cadre de cette thèse, nous nous intéressons seulement au diagnostic des SAP ayant une dynamique discrète. Nous présentons dans le premier chapitre ces systèmes, les dysfonctionnements possibles et la terminologie du diagnostic utilisée. Ensuite, nous présentons un état de l’art de différentes méthodes et approches existantes et aussi une synthèse de ces méthodes. Cette synthèse nous a motivé de choisir une approche à base de donnée qui s’appuie sur une technique d’apprentissage automatique, qui est le raisonnement à partir de cas (RàPC). Pour cela, nous avons présenté dans le deuxième chapitre un état de l’art sur l’apprentissage automatique et ses différentes méthodes en mettant l’accent essentiellement sur le RàPC et ses utilisations pour le diagnostic des systèmes industriels. Cette étude nous a permis de proposer dans le chapitre 3 une approche d’aide au diagnostic qui se base sur le RàPC. Cette approche s’appuie sur une phase hors ligne et une phase en ligne. La phase hors ligne permet de définir un format de représentation de cas et de construire une base de cas normaux (BCN) et une base de cas défaillants (BCD) à partir d’une base de données d’historique. La phase en ligne permet d’aider les opérateurs humains de surveillance à la prise de la décision du diagnostic la plus adéquate. Les résultats des expérimentations sur un système de tri de caisses ont présentés les piliers de cette approche qui résident au niveau du format de représentation de cas proposé et au niveau de la base de cas utilisé. Pour résoudre ces problèmes et améliorer les résultats, un nouveau format de représentation de cas est proposé dans le chapitre 4. Selon ce format et à partir des données issues du système simulé après son émulation en mode normal et fautif, les cas de la base de cas initiale sont construits. Ensuite, une phase de raisonnement et d’apprentissage incrémental est présentée. Cette phase permet non seulement le diagnostic du système surveillé mais aussi d’enrichir la base de cas suite à l’apparition des nouveaux comportements inconnus. Les expérimentations présentées dans le chapitre 5 sur « le plateau tournant » qui est un sous système du système « tri de caisses » ont permis de montrer l’amélioration des résultats et aussi d’évaluer et de comparer les performances de l’approche proposée vis-à-vis certaines approches d’apprentissage automatique et vis-à-vis une approche à base de modèle pour le diagnostic du plateau tournant. / Automated production systems (APS) represents an important class of industrial systems that are increasingly complex given the large number of interactions and interconnections between their different components. As a result, they are more susceptible to malfunctions, whose consequences can be significant in terms of productivity, safety and quality of production. A major challenge is to develop an intelligent approach that can be used to diagnose these systems to ensure their operational safety. In this thesis, we are only interested in the diagnosis of APS with discrete dynamics. We present in the first chapter these systems, the possible malfunctions and the used terminology for the diagnosis. Then, we present a state of the art of the existing methods for the diagnosis of this class of systems and also a synthesis of these methods. This synthesis motivated us to choose a data-based approach that relies on a machine learning technique, which is Case-Based Reasoning (CBR). For this reason, we presented in the second chapter a state of the art on machine learning and its different methods with a focus mainly on the CBR and its uses for the diagnosis of industrial systems. This study allowed us to propose in Chapter 3 a Case Based Decision Support System for the diagnosis of APS. This system is based on an online block and an offline block. The Offline block is used to define a case representation format and to build a Normal Case Base (NCB) and a Faulty Case Base (FCB) from a historical database. The online block helps human operators of monitoring to make the most appropriate diagnosis decision. The experiments results perform on a sorting system presented the pillars of this approach, which reside in the proposed case representation format and in the used case base. To solve these problems and improve the results, a new case representation format is proposed in chapter 4. According to this format and from the data acquired from the simulated system after its emulation in normal and faulty mode, cases of the initial case base are build. Then, a reasoning and incremental learning phase is presented. This phase allows the system diagnosis and the enrichment of the case base following the appearance of new unknown behaviors. The experiments presented in Chapter 5 and perform on the 'turntable' which is a subsystem of the 'sorting system” allowed to show the improvement of the results and also to evaluate and compare the performances of the proposed approach with some automatic learning approaches and with a model-based approach to turntable diagnosis.
209

Konzeption und Aufbau eines Geoinformationssystems zur Modellierung und Simulation von Offenlandschaften

Wagner, Anja January 2004 (has links)
Zwischen 1990 und 1994 wurden rund 1000 Liegenschaften, die in der ehemaligen DDR von der Sowjetarmee und der NVA für militärische Übungen genutzt wurden, an Bund und Länder übergeben. Die größten Truppenübungsplätze liegen in Brandenburg und sind heute teilweise in Großschutzgebiete integriert, andere Plätze werden von der Bundeswehr weiterhin aktiv genutzt. <br /> <br /> Aufgrund des militärischen Betriebs sind die Böden dieser Truppenübungsplätze oft durch Blindgänger, Munitionsreste, Treibstoff- und Schmierölreste bis hin zu chemischen Kampfstoffen belastet. Allerdings existieren auf fast allen Liegenschaften neben diesen durch Munition und militärische Übungen belasteten Bereichen auch naturschutzfachlich wertvolle Flächen; gerade in den Offenlandbereichen kann dies durchaus mit einer Belastung durch Kampfmittel einhergehen. Charakteristisch für diese offenen Flächen, zu denen u.a. Zwergstrauchheiden, Trockenrasen, wüstenähnliche Sandflächen und andere nährstoffarme baumlose Lebensräume gehören, sind Großflächigkeit, Abgeschiedenheit sowie ihre besondere Nutzung und Bewirtschaftung, d.h. die Abwesenheit von land- und forstwirtschaftlichem Betrieb sowie von Siedlungsflächen. Diese Charakteristik war die Grundlage für die Entwicklung einer speziell angepassten Flora und Fauna. <br /> <br /> Nach Beendigung des Militärbetriebs setzte dann in weiten Teilen eine großflächige Sukzession &ndash; die allmähliche Veränderung der Zusammensetzung von Pflanzen- und Tiergesellschaften &ndash; ein, die diese offenen Bereiche teilweise bereits in Wald verwandelte und somit verschwinden ließ. Dies wiederum führte zum Verlust der an diese Offenlandflächen gebundenen Tier- und Pflanzenarten.<br /> <br /> Zur Erhaltung, Gestaltung und Entwicklung dieser offenen Flächen wurden daher von einer interdisziplinären Gruppe von Naturwissenschaftlern verschiedene Methoden und Konzepte auf ihre jeweilige Wirksamkeit untersucht. So konnten schließlich die für die jeweiligen Standortbedingungen geeigneten Maßnahmen eingeleitet werden.<br /> <br /> Voraussetzung für die Einleitung der Maßnahmen sind zum einen Kenntnisse zu diesen jeweiligen Standortbedingungen, d.h. zum Ist-Zustand, sowie zur Entwicklung der Flächen, d.h. zur Dynamik. So kann eine Abschätzung über die zukünftige Flächenentwicklung getroffen werden, damit ein effizienter Maßnahmeneinsatz stattfinden kann.<br /> Geoinformationssysteme (GIS) spielen dabei eine entscheidende Rolle zur digitalen Dokumentation der Biotop- und Nutzungstypen, da sie die Möglichkeit bieten, raum- und zeitbezogene Geometrie- und Sachdaten in großen Mengen zu verarbeiten. Daher wurde ein fachspezifisches GIS für Truppenübungsplätze entwickelt und implementiert. Die Aufgaben umfassten die Konzeption der Datenbank und des Objektmodells sowie fachspezifischer Modellierungs-, Analyse- und Präsentationsfunktionen. Für die Integration von Fachdaten in die GIS-Datenbank wurde zudem ein Metadatenkatalog entwickelt, der in Form eines zusätzlichen GIS-Tools verfügbar ist. Die Basisdaten für das GIS wurden aus Fernerkundungsdaten, topographischen Karten sowie Geländekartierungen gewonnen.<br /> <br /> Als Instrument für die Abschätzung der zukünftigen Entwicklung wurde das Simulationstool AST4D entwickelt, in dem sowohl die Nutzung der (Raster-)Daten des GIS als Ausgangsdaten für die Simulationen als auch die Nutzung der Simulationsergebnisse im GIS möglich ist. Zudem können die Daten in AST4D raumbezogen visualisiert werden.<br /> Das mathematische Konstrukt für das Tool war ein so genannter Zellulärer Automat, mit dem die Flächenentwicklung unter verschiedenen Voraussetzungen simuliert werden kann. So war die Bildung verschiedener Szenarien möglich, d.h. die Simulation der Flächenentwicklung mit verschiedenen (bekannten) Eingangsparametern und den daraus resultierenden unterschiedlichen (unbekannten) Endzuständen. Vor der Durchführung einer der drei in AST4D möglichen Simulationsstufen können angepasst an das jeweilige Untersuchungsgebiet benutzerspezifische Festlegungen getroffen werden. / Between 1990 and 1994 more than a thousand military properties in East Germany used for military exercise by the Soviet army and the East German forces were handed over to government institutions of the national state and federal states (Laender), respectively. The largest military training areas are located in the federal state of Brandenburg. Some of these are, by now, part of environmentally protected areas, others are still being used by the German forces. <br /> <br /> As a result of long-lasting military operations the soils of these areas are heavily polluted by ammunition, duds, fuel and lubricants as well as a range of chemicals. Due to these special environmental conditions specifically adapted vegetation and fauna developed in these environments which make these areas valuable from an environmental protection perspective. Unlike other environments in North West Germany these former military training areas are characterised by wideness, separateness as well as the absence of agricultural, forest and settlement land use. This allowed for the development of a characteristic vegetation cover composed of dwarf bush heaths, drying lawns, desert-like sand surfaces and other nutrient-poor treeless habitats. <br /> <br /> Following the end of military use the process of succession &ndash; a gradual change of flora and fauna over space and time &ndash; set in. More a than a decade later the former open plains have, in part, developed into forests. The loss of open range land effected the disappearance of adapted animal and plant populations. To retain, preserve and develop these environmentally valuable areas different methods and concepts were examined for the respective effectiveness by multi-disciplinary group of scientists.<br /> <br /> Prerequisites of the application of methods to preserve the open plains are up-to-date knowledge of local conditions as well as in-depth understanding of the land surface developments and their dynamics, in particular. Based on this expertise the future surface development of these areas can be estimated which, in term, is a prerequisite for selecting the appropriate methods.<br /> <br /> Geo information systems (GIS) play an important role for the digital documentation and monitoring of biotopes, land use etc as they provide for acquisition, processing and storage of mass geo data including their locational and feature attributes. To make this GIS functionality available for the management and development of former military training areas a dedicated GIS has been developed and implemented. Tasks tackled included a database concept and object model as well as application-specific modelling, analysis and map presentation functions. Integration of relevant spatial and attribute data into this system required a meta data catalogue made available as an add-on GIS tool. <br /> Topographic base data for GIS input were taken from remote sensing imagery, topographic maps and additional field surveys.<br /> <br /> To simulate the development of the former military areas over space and time a specific simulation tool had to be developed as conventional GIS lack dynamic functionalities. The AST4D tool enables the user to utilise existing GIS data. Processed results, in term, can then be used within the GIS application. Additionally AST4D data may be visualised in map form.<br /> The AST4D GIS tool is based on the mathematical model of cellular automata. This model allows for the user-defined setting of status quo and simulation of future developments under different input parameters and target conditions.
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Risk Measures Constituting Risk Metrics for Decision Making in the Chemical Process Industry

Prem, Katherine 2010 December 1900 (has links)
The occurrence of catastrophic incidents in the process industry leave a marked legacy of resulting in staggering economic and societal losses incurred by the company, the government and the society. The work described herein is a novel approach proposed to help predict and mitigate potential catastrophes from occurring and for understanding the stakes at risk for better risk informed decision making. The methodology includes societal impact as risk measures along with tangible asset damage monetization. Predicting incidents as leading metrics is pivotal to improving plant processes and, for individual and societal safety in the vicinity of the plant (portfolio). From this study it can be concluded that the comprehensive judgments of all the risks and losses should entail the analysis of the overall results of all possible incident scenarios. Value-at-Risk (VaR) is most suitable as an overall measure for many scenarios and for large number of portfolio assets. FN-curves and F$-curves can be correlated and this is very beneficial for understanding the trends of historical incidents in the U.S. chemical process industry. Analyzing historical databases can provide valuable information on the incident occurrences and their consequences as lagging metrics (or lagging indicators) for the mitigation of the portfolio risks. From this study it can be concluded that there is a strong statistical relationship between the different consequence tiers of the safety pyramid and Heinrich‘s safety pyramid is comparable to data mined from the HSEES database. Furthermore, any chemical plant operation is robust only when a strategic balance is struck between optimal plant operations and, maintaining health, safety and sustaining environment. The balance emerges from choosing the best option amidst several conflicting parameters. Strategies for normative decision making should be utilized for making choices under uncertainty. Hence, decision theory is utilized here for laying the framework for choice making of optimum portfolio option among several competing portfolios. For understanding the strategic interactions of the different contributing representative sets that play a key role in determining the most preferred action for optimum production and safety, the concepts of game theory are utilized and framework has been provided as novel application to chemical process industry.

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