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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.
41

Elektrifieringen av personbilsflottan : En prognos över hur det ökade elbehovet påverkar Stockholms regionnät år 2030 / The electrification of the passenger car fleet : A forecast of how the increased electricity demand will affect Stockholm's regional network in 2030

Ekstrand, Charlotte January 2021 (has links)
Transportsektorn står i dagsläget för cirka en tredjedel av alla växthusgasutsläpp inom Sverige. För att arbeta i linje med Parisavtalet har Sveriges riksdag därmed beslutat att dessa utsläpp ska minska med 70 procent fram till år 2030, relativt de nivåer som uppmättes år 2010. För att uppnå målet och klara klimatomställningen, arbetar man bland annat med att påskynda elektrifieringen av transporter. Detta skulle kunna innebära stora utmaningar för det svenska elnätet, eftersom man inte byggt ut ledningar i samma takt som elbehovet har ökat. I Stockholm har det därför uppstått kapacitetsbrist, som innebär att man inte kan tillgodose regionen med el vid alla tidpunkter under året. Samtidigt kommer man inte kunna bygga ut nya ledningar till Stockholm förrän vi når cirka år 2030.  Syftet med denna studie, är att undersöka hur elektrifieringen av personbilsflottan kan komma att påverka regionnätet i Stockholm år 2030, där det redan idag råder kapacitetsbrist. Metoden som används är baserad på scenariometodik där både kvantitativa och kvalitativa data används för att konstruera två olika huvudscenarion, ett lågscenario där personbilsflottan elektrifieras långsamt och ett högscenario där personbilsflottan elektrifieras snabbt. Genom att utforska hur elbehovet skulle kunna utvecklas fram till år 2030 på timbasis för dessa scenarion, görs en uppskattning över hur många timmar om året som det skulle kunna råda kapacitetsbrist, samt hur stor effektbristen blir vid dessa tillfällen, om allt elbehov ska kunna tillgodoses. Vidare undersöks om även flexibilitetsresurser i hemmaladdningen, kan påverka hur många timmar det råder kapacitetsbrist och hur korrelation ser ut mellan antalet laddbara bilar och kapacitetsbrist.  Resultatet från studien visar att elektrifieringen av personbilsflottan kan leda till stora ansträngningar på elnätet om användare laddar utifrån egna preferenser och därmed okontrollerat, eftersom laddningen sannolikt sammanfaller med tider på dygnet när elbehovet redan är som störst. Vidare ökar antalet timmar med kapacitetsbrist proportionellt mot hur många personbilar som elektrifieras. När flexibilitetsresurser integreras i hemmaladdningen, minskar ansträngningen på elnätet dock betydligt. Att öka incitamenten för att människor ska ändra sina beteenden gällande laddning, kan därmed positiva effekter på elnätet. Men även om flexibilitetresurser integreras i hemmaladdningen, på det sätt som har antagits genomföras i denna studie, visar resultatet att det fortfarande kan uppstå kapacitetsbrist. Det finns därmed fortfarande en risk för att elektrifieringen av personbilsflottan skulle kunna försenas. / The transport sector currently accounts for about a third of all greenhouse gas emissions in Sweden. To work in line with the Paris Agreement, it has thus been decided that these emissions should be reduced by 70 percent by 2030, relative to the levels measured in 2010. To achieve this goal and cope with climate change, the Swedish parliament is, among other things, currently working towards accelerating the electrification of transports. This, in turn, could result in major challenges for the Swedish electricity grid, as power lines have not been expanded at the same rate as the need for electricity has increased. In Stockholm, it has become a problem with a lack of capacity, which means that it is not possible to satisfy the region with electricity at all times of the year. Meanwhile, it will not be possible to expand new power lines to Stockholm until we reach around the year 2030.  The purpose of this study is to investigate how the electrification of the passenger car fleet could affect the regional network in Stockholm when we reach the year 2030. The method that has been used is based on scenario methodology where both quantitative and qualitative data has been used to construct two different main scenarios. Firstly, a low scenario was constructed, where the passenger car fleet is electrified slowly, and secondly, a high scenario was constructed where the passenger car fleet is electrified rapidly. By examining how the electricity demand could develop until the year 2030 on an hourly basis for these two scenarios, an estimate is made of how many hours a year there could be a lack of capacity and how large the power shortage would be on these occasions if all the electricity demand is to be satisfied. Furthermore, it is also investigated whether flexible resources in the home-charging of electric vehicles can affect how many hours there could be a lack of capacity and what the correlation looks like between the number of electric vehicles and lack of capacity.  The result from the study shows that the electrification of the passenger car fleet can lead to a congested electricity grid if users charge their cars uncontrolled. This, as the charge is likely to coincide with times of the day when the electricity demand already is great. Furthermore, the number of hours with a lack of capacity increases in proportion to the number of passenger cars that are electrified. When flexible resources are integrated into the home-charging, the effort on the power grid is significantly reduced. Increasing the incentives for people to change their behaviours about charging can thus have positive effects on the electricity grid. However, even if flexible resources are integrated into the home charging system, the way it is assumed to be implemented here, the result shows that there may still be a lack of capacity. There is thus still a risk that the electrification of the passenger car fleet will be delayed.
42

La sectorización basada en criterios energéticos como herramienta para la gestión hídrica de redes de distribución de agua

Salguero Barceló, Francisco Javier 13 December 2021 (has links)
[ES] La sectorización de las redes ha demostrado ser una metodología estratégica en la reducción de los volúmenes incontrolados fugados, considerado uno de los principales problemas a los que tienen que enfrentarse diariamente los gestores de los sistemas de distribución de agua. Su principal objetivo es facilitar la monitorización de las redes, dividiéndolas en subsistemas, sobre los que se puede realizar un mejor y más fácil control de las anomalías en el consumo y presión. Uno de los inconvenientes que presenta esta técnica recae en su diseño. No existe una solución única, sino que atiende a diversos criterios para realizarlo. De manera generalizada, este diseño se basa en la experiencia del propio diseñador, siguiendo criterios puramente prácticos y con procesos manuales de prueba y error, cuyo grado de dificultad está vinculado al tamaño y complejidad de la propia red. Esta tesis plantea una metodología sistemática para el diseño de la sectorización de una red de distribución de agua, según criterios energéticos, con el fin de facilitar la delimitación de cada uno de los sectores de la red. Como resultado, se obtiene una organización de la red en sectores buscando una optimización energética de la misma, de tal modo que posteriores técnicas de mejora, como es el caso de la gestión de presiones, se vean favorecidas. La sectorización ha resultado ser una técnica eficaz en la búsqueda de fugas. Sin embargo, como supone una pérdida de capacidad hidráulica y una merma en la calidad del agua, esta tesis se cuestiona el planteamiento de una técnica no intrusiva alternativa que logre los mismos resultados. Así, se propone el desarrollo de una metodología que localice las fugas centrada en la interdependencia de todos los elementos y en el empleo de sensores de caudal y presión. El trabajo pone de manifiesto que es posible sectorizar la red de tal manera que se consigan mayores beneficios para la misma. Ahora bien, también es posible el empleo de otras técnicas que no requieran el cierre de tuberías pero que desprendan soluciones similares. El empleo de una técnica u otra dependerá de cada caso, de los objetivos establecidos y de la política de trabajo de cada gestor. / [CA] La sectorització de les xarxes ha demostrat ser una metodologia estratègica en la reducció dels volums incontrolats perduts, considerat un dels principals problemes als quals han d'enfrontar-se diàriament els gestors dels sistemes de distribució d'aigua. El seu principal objectiu és facilitar la monitorització de les xarxes, dividint-les en subsistemes, sobre els quals es pot realitzar un millor i més fàcil control de les anomalies en el consum i pressió. Un dels inconvenients que presenta aquesta tècnica recau en el seu disseny. No existeix una solució única, sinó que atén diversos criteris per a realitzar-ho. De manera generalitzada, aquest disseny es basa en l'experiència del propi dissenyador, seguint criteris purament pràctics i amb processos manuals de prova i error, el grau de dificultat del qual està vinculat a la grandària i complexitat de la pròpia xarxa. Aquesta tesi planteja una metodologia sistemàtica per al disseny de la sectorització d'una xarxa de distribució d'aigua, segons criteris energètics, amb la finalitat de facilitar la delimitació de cadascun dels sectors de la xarxa. Com a resultat, s'obté una organització de la xarxa en sectors buscant una optimització energètica d'aquesta, de tal manera que posteriors tècniques de millora, com és el cas de la gestió de pressions, es vegen afavorides. La sectorització ha resultat ser una tècnica eficaç en la cerca de fuites d'aigua. No obstant això, com suposa una pèrdua de capacitat hidràulica i una disminució en la qualitat de l'aigua, aquesta tesi es qüestiona el plantejament d'una tècnica no intrusiva alternativa que aconseguisca els mateixos resultats. Així, es proposa el desenvolupament d'una metodologia que localitze les fuites d'aigua centrada en la interdependència de tots els elements i en l'ús de sensors de cabal i pressió. El treball posa de manifest que és possible sectoritzar la xarxa de tal manera que s'aconseguisquen majors beneficis per a aquesta. Ara bé, també és possible l'ús d'altres tècniques que no requerisquen el tancament de canonades però que desprenguen solucions similars. L'ús d'una tècnica o una altra dependrà de cada cas, dels objectius establits i de la política de treball de cada gestor. / [EN] The sectorization of networks has proven to be a strategic methodology in the reduction of uncontrolled leakage volumes, considered one of the main problems that water distribution system managers must face on a daily basis. Its main objective is to facilitate the monitoring of the networks, dividing them into subsystems, on which a better and easier control of anomalies in consumption and pressure can be performed. One of the drawbacks of this technique lies in its design. There is no single solution, but it is based on different criteria. In general, this design is based on the designer's own experience, following purely practical criteria and with manual trial and error processes, whose degree of difficulty is linked to the size and complexity of the network itself. This thesis proposes a systematic methodology for the design of the sectorization of a water distribution network, according to energy criteria, in order to facilitate the delimitation of each of the sectors of the network. As a result, an organization of the network in sectors is obtained, looking for an energetic optimization of the same, in such a way that later improvement techniques, such as pressure management, are favoured. Sectorization has proven to be an effective technique in the search for leaks. However, as it implies a loss of hydraulic capacity and a decrease in water quality, this thesis questions the approach of an alternative non-intrusive technique that achieves the same results. Thus, it is proposed the development of a methodology to locate the leaks focused on the interdependence of all the elements and the use of flow and pressure sensors. The present work shows that it is possible to sectorize the network in such a way as to achieve greater benefits for the network. However, it is also possible to use other techniques that do not require pipe closure but provide similar solutions. The use of one technique or another will depend on each case, on the established objectives and on the working policy of each manager. / Salguero Barceló, FJ. (2021). La sectorización basada en criterios energéticos como herramienta para la gestión hídrica de redes de distribución de agua [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/178235
43

Contextualisation & Capture de Gestuelles Utilisateur : Contributions à l'Adaptativité des Applications Interactives Scénarisées / Contextualization & User Body Language Capture : Contribution to the Adaptivity of Interactive Applications

Picard, François 11 July 2011 (has links)
Depuis 50 ans, une évolution permanente de l’interaction homme-machine a permis qu’aujourd’hui, nous tendions vers des systèmes temps réel proposant une interaction simple et intuitive à l’utilisateur et s’adaptant automatiquement à l’activité observée et interprétée. L’utilisateur peut dorénavant interagir avec un système informatique, volontairement ou de manière non consciente, par le biais de plusieurs modalités, comme il ferait dans la vie courante. Actuellement, les systèmes les plus développés sont ceux permettant à l’utilisateur d’interagir par le biais de gestuelles, qu’elles soient explicites ou implicites. Ces systèmes sont intégrés de plus en plus dans notre environnement, la plupart du temps invisibles pour nous, et s’adaptent en fonction d’un scénario qui définit les objectifs que nous devons atteindre.Plusieurs domaines d’application sont le cadre du développement de tels systèmes, comme celui du jeu vidéo ou encore de la surveillance vidéo. Nous proposons, dans ces travaux de thèse, l’architecture d’un système interactif, sur lequel s’exécute une application scénarisée de type jeu vidéo. L’interactivité est alimentée par les gestuelles du corps d’un unique utilisateur, en temps réel et de manière non invasive. Le système réagit également à divers événements prenant place au sein de la scène réelle, qui sont dus au dynamisme de cette dernière et dont l’utilisateur n’est pas directement responsable (changement d’éclairage, présence de spectateurs, etc.). L’utilisateur est immergé au sein d’un environnement virtuel qui traduit la réponse interactive du système. Ce dernier répond également, en temps réel, à l’activité observée et interprétée, de manière adaptative, adaptant à la fois sa réponse interactive et son fonctionnement global.Nos travaux se basent sur l’hypothèse que l’activité observée au sein de la scène est caractérisée par le contexte d’interaction qui l’englobe. Notre système reconnaît ainsi l’activité en modélisant le contexte d’interaction au sein duquel elle prend place. Notre contribution principale se traduit donc par l’introduction de la notion de contexte au sein des processus interactif et adaptatif. La modélisation du contexte d’interaction que nous proposons nous a servi de base pour celle du scénario d’une application. La gestion et l’analyse de ce contexte au cours de l’interactivité permettent au système d’interpréter l’activité observée et de paramétrer les différents mécanismes adaptatifs qui en découlent. L’activité est capturée et codifiée par un système étendu, adopté en accord avec le cadre industriel de cette thèse (convention CIFRE avec la société XD Productions). Initialement dédié à la capture, invasive et en milieu contrôlé, des mouvements de l’utilisateur, nos travaux ont permis l’augmentation du processus vers une capture plus générale de l’activité globale,de manière non invasive et en environnement dynamique. Enfin, nous avons développé une application immergeant l’utilisateur au sein d’une simulation virtuelle d’entrainement au tennis. Par le biais d’études de cas extraites de ce scénario, nous avons implémenté les processus interactif et adaptatif prenant place entre le système et l’utilisateur. L’adaptativité du système, supportée par le scénario de l’application, est concrétisée par la mise en place de mécanismes spécifiques à tous les niveaux de l’architecture, en fonction de l’activité observée et interprétée. Nous mettons en évidence un ensemble de boucles logicielles, appelées « boucles vertueuses », générées par l’accumulation des effets d’adaptation du système et améliorant en permanence l’interactivité. Les perspectives à ces travaux de thèse concernent la normalisation et la gestion haut niveau de notre modèle de contexte, la complexification de notre scénario et l’amélioration de notre système de capture dans le cadre de nouvelles applications scénarisées. / For 50 years, human-computer interaction has evolved permanently. Nowadays, real-time systems offer the user simple and intuitive interaction and adapt automatically to the observed and interpreted activity. From now on, the user can interact with computer systems, voluntarily or unconsciously, by several modalities, as he would do it in his everyday life.Currently, the most developed systems are the ones allowing the user to interact by his explicit or implicit body language. These systems are more and more integrated in our environment, are invisible, and adapt according to the scenario that defines the objectives the user has to achieve. Several application fields are the development frameworks of such systems, like video games or video surveillance. We define in this work the architecture of an interactive system, upon which runs a scripted application such as a video game. The interactivity is fed by an only user body language, in real-time and without markers. The system reacts as well to various events taking place within the real scene. These events aredue to the scene dynamism for which the user is not directly responsible (illumination changes, spectators, etc.).The user is immersed within a virtual environment that renders the system interactive response. The system responds adaptively as well, in real-time, to the observed and interpreted activity, adapting at the same time its interactive response and its global functioning. Our work is based on the following hypothesis: the activity, observed within the scene, is characterized by the interaction context that includes it. Thus, our system recognizes the activity by modelling the interaction context within which it takes place. Our main contribution is then the introduction of the notion of context within the interactive and adaptive processes. We use our interaction context modelling to model the application scenario. The context management and analysis during the interactivity allow the system to interpret the observed activity and to configure the different adaptive mechanisms which follow it. The activity is captured and codified by an extended system, chosen according to our work industrial framework (Industrial Convention of Formation by Research – CIFRE – with XDProductions). Initially dedicated to the invasive capture of the user movements in a controlled environment, our work enhances the process towards the general capture of the global activity, without markers and within an uncontrolled environment. Finally, we have developed an application immersing the user within a virtual simulation of tennis training. Thanks to different case studies extracted from this scenario, we have implemented the interactive and adaptive processes taking place between the system and the user. The system adaptivity, supported by the application scenario, is materialized by the implementation of specific mechanisms at every level of the architecture, according to the observed and interpreted activity. We have brought to light a set of software loops, called virtuous loops, generated by the accumulation of the system adaptation effects and improving the interactivity permanently. Our work perspectives concern the formalization and the high-level management of our context model, the complexity of our scenario and the improvement of our capture systemwithin the framework of new scripted applications.
44

Reconhecimento multibiométrico baseado em imagens de face parcialmente ocluídas / Multibiometric Recognition Based on Partially Occluded Face Images

Araújo Junior, Jozias Rolim de 28 May 2018 (has links)
Com o avanço da tecnologia, as estratégias tradicionais para identificação de pessoas se tornaram mais suscetíveis a falhas. De forma a superar essas dificuldades algumas abordagens vêm sendo propostas na literatura. Dentre estas abordagens destaca-se a Biometria. O campo da Biometria abarca uma grande variedade de tecnologias usadas para identificar ou verificar a identidade de uma pessoa por meio da mensuração e análise de aspectos físicos e/ou comportamentais do ser humano. Em função disso, a biometria tem um amplo campo de aplicações em sistemas que exigem uma identificação segura de seus usuários. Os sistemas biométricos mais populares são baseados em reconhecimento facial ou em impressões digitais. Entretanto, existem sistemas biométricos que utilizam a íris, varredura de retina, voz, geometria da mão e termogramas faciais. Atualmente, tem havido progresso significativo em reconhecimento automático de face em condições controladas. Em aplicações do mundo real, o reconhecimento facial sofre de uma série de problemas nos cenários não controlados. Esses problemas são devidos, principalmente, a diferentes variações faciais que podem mudar muito a aparência da face, incluindo variações de expressão, de iluminação, alterações da pose, assim como oclusões parciais. Em comparação com o grande número de trabalhos na literatura em relação aos problemas de variação de expressão/iluminação/pose, o problema de oclusão é relativamente negligenciado pela comunidade científica. Embora tenha sido dada pouca atenção ao problema de oclusão na literatura de reconhecimento facial, a importância deste problema deve ser enfatizada, pois a presença de oclusão é muito comum em cenários não controlados e pode estar associada a várias questões de segurança. Por outro lado, a Multibiométria é uma abordagem relativamente nova para representação de conhecimento biométrico que visa consolida múltiplas fontes de informação visando melhorar a performance do sistema biométrico. Multibiométria é baseada no conceito de que informações obtidas a partir de diferentes modalidades ou da mesma modalidade capturada de diversas formas se complementam. Consequentemente, uma combinação adequada dessas informações pode ser mais útil que o uso de informações obtidas a partir de qualquer uma das modalidades individualmente. A fim de melhorar a performance dos sistemas biométricos faciais na presença de oclusão parciais será investigado o emprego de diferentes técnicas de reconstrução de oclusões parciais de forma a gerar diferentes imagens de face, as quais serão combinadas no nível de extração de característica e utilizadas como entrada para um classificador neural. Os resultados demonstram que a abordagem proposta é capaz de melhorar a performance dos sistemas biométricos baseados em face parcialmente ocluídas / With the advancement of technology, traditional strategies for identifying people have become more susceptible to failures. In order to overcome these difficulties, some approaches have been proposed in the literature. Among these approaches, Biometrics stands out. The field of biometrics covers a wide range of technologies used to identify or verify a person\'s identity by measuring and analyzing physical and / or behavioral aspects of the human being. As a result, a biometry has a wide field of applications in systems that require a secure identification of its users. The most popular biometric systems are based on facial recognition or fingerprints. However, there are biometric systems that use the iris, retinal scan, voice, hand geometry, and facial thermograms. Currently, there has been significant progress in automatic face recognition under controlled conditions. In real world applications, facial recognition suffers from a number of problems in uncontrolled scenarios. These problems are mainly due to different facial variations that can greatly change the appearance of the face, including variations in expression, illumination, posture, as well as partial occlusions. Compared with the large number of papers in the literature regarding problems of expression / illumination / pose variation, the occlusion problem is relatively neglected by the research community. Although attention has been paid to the occlusion problem in the facial recognition literature, the importance of this problem should be emphasized, since the presence of occlusion is very common in uncontrolled scenarios and may be associated with several safety issues. On the other hand, multibiometry is a relatively new approach to biometric knowledge representation that aims to consolidate multiple sources of information to improve the performance of the biometric system. Multibiometry is based on the concept that information obtained from different modalities or from the same modalities captured in different ways complement each other. Accordingly, a suitable combination of such information may be more useful than the use of information obtained from any of the individuals modalities. In order to improve the performance of facial biometric systems in the presence of partial occlusion, the use of different partial occlusion reconstruction techniques was investigated in order to generate different face images, which were combined at the feature extraction level and used as input for a neural classifier. The results demonstrate that the proposed approach is capable of improving the performance of biometric systems based on partially occluded faces
45

Reconhecimento multibiométrico baseado em imagens de face parcialmente ocluídas / Multibiometric Recognition Based on Partially Occluded Face Images

Jozias Rolim de Araújo Junior 28 May 2018 (has links)
Com o avanço da tecnologia, as estratégias tradicionais para identificação de pessoas se tornaram mais suscetíveis a falhas. De forma a superar essas dificuldades algumas abordagens vêm sendo propostas na literatura. Dentre estas abordagens destaca-se a Biometria. O campo da Biometria abarca uma grande variedade de tecnologias usadas para identificar ou verificar a identidade de uma pessoa por meio da mensuração e análise de aspectos físicos e/ou comportamentais do ser humano. Em função disso, a biometria tem um amplo campo de aplicações em sistemas que exigem uma identificação segura de seus usuários. Os sistemas biométricos mais populares são baseados em reconhecimento facial ou em impressões digitais. Entretanto, existem sistemas biométricos que utilizam a íris, varredura de retina, voz, geometria da mão e termogramas faciais. Atualmente, tem havido progresso significativo em reconhecimento automático de face em condições controladas. Em aplicações do mundo real, o reconhecimento facial sofre de uma série de problemas nos cenários não controlados. Esses problemas são devidos, principalmente, a diferentes variações faciais que podem mudar muito a aparência da face, incluindo variações de expressão, de iluminação, alterações da pose, assim como oclusões parciais. Em comparação com o grande número de trabalhos na literatura em relação aos problemas de variação de expressão/iluminação/pose, o problema de oclusão é relativamente negligenciado pela comunidade científica. Embora tenha sido dada pouca atenção ao problema de oclusão na literatura de reconhecimento facial, a importância deste problema deve ser enfatizada, pois a presença de oclusão é muito comum em cenários não controlados e pode estar associada a várias questões de segurança. Por outro lado, a Multibiométria é uma abordagem relativamente nova para representação de conhecimento biométrico que visa consolida múltiplas fontes de informação visando melhorar a performance do sistema biométrico. Multibiométria é baseada no conceito de que informações obtidas a partir de diferentes modalidades ou da mesma modalidade capturada de diversas formas se complementam. Consequentemente, uma combinação adequada dessas informações pode ser mais útil que o uso de informações obtidas a partir de qualquer uma das modalidades individualmente. A fim de melhorar a performance dos sistemas biométricos faciais na presença de oclusão parciais será investigado o emprego de diferentes técnicas de reconstrução de oclusões parciais de forma a gerar diferentes imagens de face, as quais serão combinadas no nível de extração de característica e utilizadas como entrada para um classificador neural. Os resultados demonstram que a abordagem proposta é capaz de melhorar a performance dos sistemas biométricos baseados em face parcialmente ocluídas / With the advancement of technology, traditional strategies for identifying people have become more susceptible to failures. In order to overcome these difficulties, some approaches have been proposed in the literature. Among these approaches, Biometrics stands out. The field of biometrics covers a wide range of technologies used to identify or verify a person\'s identity by measuring and analyzing physical and / or behavioral aspects of the human being. As a result, a biometry has a wide field of applications in systems that require a secure identification of its users. The most popular biometric systems are based on facial recognition or fingerprints. However, there are biometric systems that use the iris, retinal scan, voice, hand geometry, and facial thermograms. Currently, there has been significant progress in automatic face recognition under controlled conditions. In real world applications, facial recognition suffers from a number of problems in uncontrolled scenarios. These problems are mainly due to different facial variations that can greatly change the appearance of the face, including variations in expression, illumination, posture, as well as partial occlusions. Compared with the large number of papers in the literature regarding problems of expression / illumination / pose variation, the occlusion problem is relatively neglected by the research community. Although attention has been paid to the occlusion problem in the facial recognition literature, the importance of this problem should be emphasized, since the presence of occlusion is very common in uncontrolled scenarios and may be associated with several safety issues. On the other hand, multibiometry is a relatively new approach to biometric knowledge representation that aims to consolidate multiple sources of information to improve the performance of the biometric system. Multibiometry is based on the concept that information obtained from different modalities or from the same modalities captured in different ways complement each other. Accordingly, a suitable combination of such information may be more useful than the use of information obtained from any of the individuals modalities. In order to improve the performance of facial biometric systems in the presence of partial occlusion, the use of different partial occlusion reconstruction techniques was investigated in order to generate different face images, which were combined at the feature extraction level and used as input for a neural classifier. The results demonstrate that the proposed approach is capable of improving the performance of biometric systems based on partially occluded faces
46

Bacterial diversity and denitrifier communities in arable soils

Coyotzi Alcaraz, Sara Victoria January 2014 (has links)
Agricultural management is essential for achieving optimum crop production and maintaining soil quality. Soil microorganisms are responsible for nutrient cycling and are an important consideration for effective soil management. The overall goal of the present research was to better understand microbial communities in agricultural soils as they relate to soil management practices. For this, we evaluated the differential impact of two contrasting drainage practices on microbial community composition and characterized active denitrifiers from selected agricultural sites. Field drainage is important for crop growth in arable soils. Controlled and uncontrolled tile drainage practices maintain water in the field or fully drain it, respectively. Because soil water content influences nutrient concentration, moisture, and oxygen availability, the effects of these two disparate practices on microbial community composition was compared in paired fields that had diverse land management histories. Libraries of the 16S rRNA gene were generated from DNA from 168 soil samples collected from eight fields during the 2012 growing season. Paired-end sequencing using next-generation sequencing was followed by read assembly and multivariate statistical analyses. Results showed that drainage practice exerted no measureable effect on the bacterial communities. However, bacterial communities were impacted by plant cultivar and applied fertilizer, in addition to sampled soil depth. Indicator species were only recovered for depth; plant cultivar or applied fertilizer type had no strong and specific indicator species. Among indicator species for soil depth (30-90 cm) were Chloroflexi (Anaerolineae), Betaproteobacteria (Janthinobacterium, Herminiimonas, Rhodoferax, Polaromonas), Deltaproteobacteria (Anaeromyxobacter, Geobacter), Alphaproteobacteria (Novosphingobium, Rhodobacter), and Actinobacteria (Promicromonospora). Denitrification in agricultural fields transforms nitrogen applied as fertilizer, reduces crop production, and emits N2O, which is a potent greenhouse gas. Agriculture is the highest anthropogenic source of N2O, which underlines the importance of understanding the microbiology of denitrification for reducing greenhouse gas emissions by altered management practices. Existing denitrifier probes and primers are biased due to their development based mostly on sequence information from cultured denitrifiers. To circumvent this limitation, this study investigated active and uncultivated denitrifiers from two agricultural sites in Ottawa, Ontario. Using DNA stable-isotope probing, we enriched nucleic acids from active soil denitrifiers by exposing intact replicate soil cores to NO3- and 13C6-glucose under anoxic conditions using flow-through reactors, with parallel native substrate controls. Spectrophotometric chemistry assays and gas chromatography confirmed active NO3- depletion and N2O production, respectively. Duplicate flow-through reactors were sacrificed after one and four week incubation periods to assess temporal changes due to food web dynamics. Soil DNA was extracted and processed by density gradient ultracentrifugation, followed by fractionation to separate DNA contributed by active denitrifiers (i.e., “heavy” DNA) from that of the background community (i.e., “light” DNA). Light and heavy DNA samples were analyzed by paired-end sequencing of 16S rRNA genes using next-generation sequencing. Multivariate statistics of assembled 16S rRNA genes confirmed unique taxonomic representation in heavy fractions from flow-through reactors fed 13C6-glucose, which exceeded any site-specific or temporal shifts in putative denitrifiers. Based on high relative abundance in heavy DNA, labelled taxa affiliated with the Betaproteobacteria (71%; Janthinobacterium, Acidovorax, Azoarcus, Dechloromonas), Alphaproteobacteria (8%; Rhizobium), Gammaproteobacteria (4%; Pseudomonas), and Actinobacteria (4%; Streptomycetaceae). Metagenomic DNA from the original soil and recovered heavy fractions were subjected to next-generation sequencing and the results demonstrated enrichment of denitrification genes with taxonomic affiliations to Brucella, Ralstonia, and Chromobacterium in heavy fractions of flow-through reactors fed 13C6-glucose. The vast majority of heavy-DNA-associated nitrite-reductase reads annotated to the copper-containing form (nirK), rather than the heme-containing enzyme (nirS). Analysis of recovered nirK genes demonstrated low sequence identity across common primer-binding sites used for the detection and quantification of soil denitrifiers, indicating that these active denitrifiers would not have been detected in molecular surveys of these same soils.
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Perception and control of upper limb movement: Insights gained by analysis of sensory and motor variability

Domkin, Dmitry January 2005 (has links)
Chronic neck-shoulder pain is associated with impairments of proprioception and motor control. Thus, assessment of proprioceptive and motor function may be powerful tools both for research and clinical practice. However, insufficient knowledge of certain features of human sensorimotor control hampers both development and interpretation of results of clinically relevant tests. For example, evidence is lacking which proprioception submodalities are reflected in common tests of proprioception. For testing motor function, a better understanding of the control of goal directed arm movements is needed. The purpose of the thesis was to gain further insights into the sensorimotor control of the upper limb in healthy subjects, with implications for clinical testing. The main aims were: (1) to study relationships of outcomes of different tests of shoulder proprioception and (2) to study control strategies in bimanual pointing tasks by analysis of the structure of joint angle variability with the Uncontrolled Manifold (UCM) method. Correlations between proprioceptive acuity in different variants of ipsilateral position-matching and velocity-discrimination were studied. The main finding was that two uncorrelated mechanisms based either on perception of position or movement might underlie perception of limb location in ipsilateral position-matching. The results provided important information for interpretation of common and development of novel tests of shoulder proprioception. The structure of joint angle variance was computed with respect to several task variables during bimanual pointing. Joint angle variability was decomposed in variance affecting and not affecting a task variable. The results showed that the variance in joint space was structured according to the predictions of the UCM hypothesis. It was also shown that the arms were united into one synergy to significantly larger degree than joints within each arm were united into single-arm synergies. It was concluded that the UCM approach might quantify components of motor variability during repetitive motor tasks.
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Low-cost housing in Witzenberg local municipality

Philander, Theresa-Anne 02 1900 (has links)
ABSTRACT The purpose of the study is to evaluate the housing process of Witzenberg Local Municipality and determine the involvement of the community and their perception regarding the whole process. The researcher is using a qualitative method to obtain the views, perspectives and feelings of the participants. For the purpose of the study is data collection limited to the sample population of people on the waiting list and those already in possession of low-cost house of the seven townships in the Witzenberg Local Municipality to. The researcher made use of questionnaires and interviews to collect data to make a profound finding and recommendation. In Witzenberg, 41% of households earn less than R30000 per annum (Witzenberg Local Municipality 2012: Online) which indicate that the Witzenberg Local Municipality has a high need for subsidized housing. The waiting list for low-cost housing in the Witzenberg Local Municipality currently stands at 6278 of which 1478 are a blocked housing project and a backlog of 4800 houses. The inhabitants of the Municipality received low-cost housing 8 years ago (Witzenberg Local Municipality 2012: Online). Witzenberg Local Municipality does has a housing problem, which stems from finance, affordability, insufficient land to erect housing projects, overcrowding, and quality of housing, staff shortage, unemployment, uncontrolled farm evictions and community involvement (Witzenberg Local Municipality 2007a:Online). Low-cost housing is in demand to address the challenges. Farm evictions, influx into the Witzenberg Local Municipality and forming of informal dwellings and increasing of squatter camps hold a serious threat to build sustainable, quality low-cost housing in the Witzenberg Local Municipality and with limit staff is in-flux control very hard to manage. Although the homeowners of the Witzenberg Local Municipality are happy to have received houses, they expressed much concern about the poor construction work, overall quality of the materials used as well as the housing process adopted by the Witzenberg Local Municipality. / Public Administration / M. Admin.
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Repousser les limites de l'identification faciale en contexte de vidéo-surveillance / Breaking the limits of facial identification in video-surveillance context.

Fiche, Cécile 31 January 2012 (has links)
Les systèmes d'identification de personnes basés sur le visage deviennent de plus en plus répandus et trouvent des applications très variées, en particulier dans le domaine de la vidéosurveillance. Or, dans ce contexte, les performances des algorithmes de reconnaissance faciale dépendent largement des conditions d'acquisition des images, en particulier lorsque la pose varie mais également parce que les méthodes d'acquisition elles mêmes peuvent introduire des artéfacts. On parle principalement ici de maladresse de mise au point pouvant entraîner du flou sur l'image ou bien d'erreurs liées à la compression et faisant apparaître des effets de blocs. Le travail réalisé au cours de la thèse porte donc sur la reconnaissance de visages à partir d'images acquises à l'aide de caméras de vidéosurveillance, présentant des artéfacts de flou ou de bloc ou bien des visages avec des poses variables. Nous proposons dans un premier temps une nouvelle approche permettant d'améliorer de façon significative la reconnaissance des visages avec un niveau de flou élevé ou présentant de forts effets de bloc. La méthode, à l'aide de métriques spécifiques, permet d'évaluer la qualité de l'image d'entrée et d'adapter en conséquence la base d'apprentissage des algorithmes de reconnaissance. Dans un second temps, nous nous sommes focalisés sur l'estimation de la pose du visage. En effet, il est généralement très difficile de reconnaître un visage lorsque celui-ci n'est pas de face et la plupart des algorithmes d'identification de visages considérés comme peu sensibles à ce paramètre nécessitent de connaître la pose pour atteindre un taux de reconnaissance intéressant en un temps relativement court. Nous avons donc développé une méthode d'estimation de la pose en nous basant sur des méthodes de reconnaissance récentes afin d'obtenir une estimation rapide et suffisante de ce paramètre. / The person identification systems based on face recognition are becoming increasingly widespread and are being used in very diverse applications, particularly in the field of video surveillance. In this context, the performance of the facial recognition algorithms largely depends on the image acquisition context, especially because the pose can vary, but also because the acquisition methods themselves can introduce artifacts. The main issues are focus imprecision, which can lead to blurred images, or the errors related to compression, which can introduce the block artifact. The work done during the thesis focuses on facial recognition in images taken by video surveillance cameras, in cases where the images contain blur or block artifacts or show various poses. First, we are proposing a new approach that allows to significantly improve facial recognition in images with high blur levels or with strong block artifacts. The method, which makes use of specific noreference metrics, starts with the evaluation of the quality level of the input image and then adapts the training database of the recognition algorithms accordingly. Second, we have focused on the facial pose estimation. Normally, it is very difficult to recognize a face in an image taken from another viewpoint than the frontal one and the majority of facial identification algorithms which are robust to pose variation need to know the pose in order to achieve a satisfying recognition rate in a relatively short time. We have therefore developed a fast and satisfying pose estimation method based on recent recognition techniques.
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Metodika zdaňování úroků z titulu poskytnutí zápůjčky mezi spojenými osobami / Methodology for Taxation of Loan Interests between Associated Enterprises

Kropáčová, Hana January 2017 (has links)
Diploma thesis deals with the issue of loan interest taxation between associated enterprises which are Czech residents. The basic theoretical concepts are described in the first part of thesis. The second part is focused on the analysis Czech law connected with interest taxation. The practical part is based on forming methodological tool for associated enterprises. This methodology can help to set the right loan interest rate. There are also practical examples solved in the end of the diploma thesis.

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