• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 10
  • 3
  • 1
  • 1
  • 1
  • Tagged with
  • 16
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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.
1

Virtual Characters for a Virtual Classroom

Nilsson, Jesper January 2015 (has links)
Projektet hade sin bakgrund i önskan att tillhandahålla en virtuell träningsmiljö för lärare där de kan öva på sin icke-verbala kommunikation med elever. Före det här projektet hade utvecklingen av träningsmiljön lett fram till ett visualiserings-system för ett tredimensionellt virtuellt klassrum med animerade karaktärer samt ett system för upptagning och igenkänning av användarens rörelser. För att en sådan träningsmiljö skall vara användbar krävs dock att de virtuella studenterna uppvisar ett trovärdigt mänskligt beteende. Den här rapporten avhandlar implementationen av mänskligt beteende i agenterna förkroppsligade i visualiseringssystemet. För detta ändamål användes det BDI-baserade multi-agent-systemet Jason tillsammans med inspiration från personlighetsteorin OCEAN, affektionsteorin OCC och beteendearkitekturen PMFserv. Rapporten avhandlar även resultatet av ett experiment som utfördes för att utvärdera systemet. I experimentet blev 16 testpersoner introducerade för två olika lärar-scenarion, varpå de, för var och en av dessa scenarion, fyllde i en enkät om deras upplevelse. / The project had its background in the desire to provide a virtual training environment for teachers in which they can exercise their non-verbal communication (e.g. gestures and orientation) with students. Prior to this project, the development of the training environment had led up to a visualisation system for a 3D virtual classroom with virtual students and a motion recognition system for capturing and recognising the user's movements. For such a training environment to be useful however, the virtual students need to express believable human behaviour. This report covers the implementation of human behaviour in the agents embodied in the visualisation system using the BDI-based Jason multi-agent simulation platform with further inspiration taken from the OCEAN personality theory, the OCC theory of emotions and the PMFserv cognitive architecture. It also covers the results of an experiment that was conducted to evaluate the system. During this experiment, 16 test persons were introduced to two different teaching scenarios and were asked to fill in a questionnaire about their experience after each scenario.
2

Advanced natural language processing for improved prosody in text-to-speech synthesis / G. I. Schlünz

Schlünz, Georg Isaac January 2014 (has links)
Text-to-speech synthesis enables the speech-impeded user of an augmentative and alternative communication system to partake in any conversation on any topic, because it can produce dynamic content. Current synthetic voices do not sound very natural, however, lacking in the areas of emphasis and emotion. These qualities are furthermore important to convey meaning and intent beyond that which can be achieved by the vocabulary of words only. Put differently, speech synthesis requires a more comprehensive analysis of its text input beyond the word level to infer the meaning and intent that elicit emphasis and emotion. The synthesised speech then needs to imitate the effects that these textual factors have on the acoustics of human speech. This research addresses these challenges by commencing with a literature study on the state of the art in the fields of natural language processing, text-to-speech synthesis and speech prosody. It is noted that the higher linguistic levels of discourse, information structure and affect are necessary for the text analysis to shape the prosody appropriately for more natural synthesised speech. Discourse and information structure account for meaning, intent and emphasis, and affect formalises the modelling of emotion. The OCC model is shown to be a suitable point of departure for a new model of affect that can leverage the higher linguistic levels. The audiobook is presented as a text and speech resource for the modelling of discourse, information structure and affect because its narrative structure is prosodically richer than the random constitution of a traditional text-to-speech corpus. A set of audiobooks are selected and phonetically aligned for subsequent investigation. The new model of discourse, information structure and affect, called e-motif, is developed to take advantage of the audiobook text. It is a subjective model that does not specify any particular belief system in order to appraise its emotions, but defines only anonymous affect states. Its cognitive and social features rely heavily on the coreference resolution of the text, but this process is found not to be accurate enough to produce usable features values. The research concludes with an experimental investigation of the influence of the e-motif features on human speech and synthesised speech. The aligned audiobook speech is inspected for prosodic correlates of the cognitive and social features, revealing that some activity occurs in the into national domain. However, when the aligned audiobook speech is used in the training of a synthetic voice, the e-motif effects are overshadowed by those of structural features that come standard in the voice building framework. / PhD (Information Technology), North-West University, Vaal Triangle Campus, 2014
3

Um protótipo de autoria de histórias OCC-RDD para ambientes de aprendizagem presencial

Buttignon, Karina 01 September 2015 (has links)
Made available in DSpace on 2016-04-29T14:23:37Z (GMT). No. of bitstreams: 1 Karina Buttignon.pdf: 2998214 bytes, checksum: 29e7a72d8e08d7a68e766e6ee13e1ba1 (MD5) Previous issue date: 2015-09-01 / This study was designed with the desire to propose new approaches to teaching and learning process, modeling a teaching methodology that could support the teacher and the student, leading them to a more interactive experimentation for teaching in the course of computing by means of narratives as a way to teach using the OCC-RDD technique widely discussed in GEMS (Study Group on Software Modeling) of the TIDD at PUC / SP, supported by cognitive levels of Bloom's Taxonomy. The research proposes the development of a prototype for creating and manipulating stories within the educational context dealing conjectured scenarios scenes "objective," "mishap" and "Catastrophe", provided for in the OCC-RDD technique already mentioned. The literature review still permeates the work of Mieke Bal on the dynamics of functioning of fables, including guiding the entries used in this study. The motivation for this study, in addition to everyday observation arising from the unrest in the teaching practice, took breath in contact with the dropout data recorded in the area of computing, especially in the learning point of view. Among the situations mentioned by bibliographic studies, no understandings of the disciplines that require proficiency in logic, are the most incidents. Having done this formation process guided by the tenets found in the literature review, we understand the importance of bringing the creation of a prototype that could give plasticity ace mental conceptions formatted in the process of understanding of all these variables. The dissertation this separated into six chapters the first corresponds to contextualize the work, the second chapter deals with the theoretical framework of the relationship of computing with cognitive science, the OCC-RDD technique and its characteristics, the third chapter is based on the theories of Mieke Bal to construct fables in an attempt to create OCC-RDD fables scenarios in the fourth chapter presents three case studies applied at a college in the course of computing, chapter five describes and presents the model of a prototype and sixth chapter completion and collaborations for future work / Este estudo foi concebido com o anseio de propor novas abordagens no processo ensino e aprendizagem, modelando uma metodologia de docência que pudessem apoiar o professor e o aluno, levando-os a uma experimentação mais interativa quanto ao ensino no curso de computação, por meio do uso de narrativas como uma forma de ensinar, utilizando a técnica OCC-RDD amplamente discutida no GEMS (Grupo de Estudos em Modelagem de Software) do TIDD na PUC/SP, apoiada pelos níveis cognitivos da Taxonomia de Bloom. O trabalho de pesquisa propõe o desenvolvimento de um protótipo para criação e manipulação histórias dentro do contexto de ensino tratando cenários conjecturados de cenas Objetivo , Contratempo e Catástrofe , previstos na técnica OCC-RDD, já mencionada. A revisão bibliográfica ainda permeia o trabalho de Mieke Bal sobre a dinâmica de funcionamento das fábulas, orientando inclusive os verbetes utilizados neste estudo. A motivação para este estudo, além das inquietações oriundas da observação cotidiana na pratica docente, tomaram fôlego em contado com os dados de evasão escolar registrados para a área da computação, principalmente no ponto de vista da aprendizagem. Dentre as situações apontadas pelos estudos bibliográficos, o não entendimento das disciplinas que exigem uma proficiência em lógica, são os mais incidentes. Tendo feito esse itinerário formativo norteado pelos postulados encontrados na revisão bibliográfica, entendeu-se a importância da propositura da criação de um protótipo que pudesse dar plasticidade ás concepções mentais formatadas durante o processo de entendimento de todas essas variáveis. A dissertação esta separada em seis capítulos, o primeiro corresponde à contextualização do trabalho, o segundo capítulo trata da fundamentação teórica sobre a relação da computação com a ciência cognitiva, a técnica OCC-RDD e suas características, o terceiro capítulo fundamenta-se nas teorias de Mieke Bal para a construção de fábulas, na tentativa de criar cenários de fábulas OCC-RDD no quarto capítulo apresentam-se três estudos de casos aplicados em uma faculdade no curso de computação, o capítulo cinco descreve e apresenta o modelo de um protótipo e no sexto capítulo a conclusão e colaborações para trabalhos futuros
4

Maintaining data consistency in embedded databases for vehicular systems

Gustafsson, Thomas January 2004 (has links)
<p>The amount of data handled by real-time and embedded applications is increasing. This calls for data-centric approaches when designing embedded systems, where data and its metainformation (e.g., temporal correctness requirements) are stored centrally. The focus of this thesis is on efficient data management, especially maintaining data freshness and guaranteeing correct age on data.</p><p>The contributions of our research are updating algorithms and concurrency control algorithms using data similarity. The updating algorithms keep data items up-to-date and can adapt the number of updates of data items to state changes in the external environment. Further, the updating algorithms can be extended with a relevance check allowing for skipping of unnecessary calculations. The adaptability and skipping of updates have positive effects on the CPU utilization, and freed CPU resources can be reallocated to, e.g., more extensive diagnosis of the system. The proposed multiversion concurrency control algorithms guarantee calculations reading data that is correlated in time.</p><p>Performance evaluations show that updating algorithms with a relevance check give significantly better performance compared to well-established updating approaches, i.e., the applications use more fresh data and are able to complete more tasks in time. The proposed multiversion concurrency control algorithms perform better than HP2PL and OCC and can at the same time guarantee correct age on data items, which HP2PL and OCC cannot guarantee. Thus, from the perspective of the application, more precise data is used to achieve a higher data quality overall, while the number of updates is reduced.</p> / Report code: LiU-Tek-Lic-2004:67.
5

Advanced natural language processing for improved prosody in text-to-speech synthesis / G. I. Schlünz

Schlünz, Georg Isaac January 2014 (has links)
Text-to-speech synthesis enables the speech-impeded user of an augmentative and alternative communication system to partake in any conversation on any topic, because it can produce dynamic content. Current synthetic voices do not sound very natural, however, lacking in the areas of emphasis and emotion. These qualities are furthermore important to convey meaning and intent beyond that which can be achieved by the vocabulary of words only. Put differently, speech synthesis requires a more comprehensive analysis of its text input beyond the word level to infer the meaning and intent that elicit emphasis and emotion. The synthesised speech then needs to imitate the effects that these textual factors have on the acoustics of human speech. This research addresses these challenges by commencing with a literature study on the state of the art in the fields of natural language processing, text-to-speech synthesis and speech prosody. It is noted that the higher linguistic levels of discourse, information structure and affect are necessary for the text analysis to shape the prosody appropriately for more natural synthesised speech. Discourse and information structure account for meaning, intent and emphasis, and affect formalises the modelling of emotion. The OCC model is shown to be a suitable point of departure for a new model of affect that can leverage the higher linguistic levels. The audiobook is presented as a text and speech resource for the modelling of discourse, information structure and affect because its narrative structure is prosodically richer than the random constitution of a traditional text-to-speech corpus. A set of audiobooks are selected and phonetically aligned for subsequent investigation. The new model of discourse, information structure and affect, called e-motif, is developed to take advantage of the audiobook text. It is a subjective model that does not specify any particular belief system in order to appraise its emotions, but defines only anonymous affect states. Its cognitive and social features rely heavily on the coreference resolution of the text, but this process is found not to be accurate enough to produce usable features values. The research concludes with an experimental investigation of the influence of the e-motif features on human speech and synthesised speech. The aligned audiobook speech is inspected for prosodic correlates of the cognitive and social features, revealing that some activity occurs in the into national domain. However, when the aligned audiobook speech is used in the training of a synthetic voice, the e-motif effects are overshadowed by those of structural features that come standard in the voice building framework. / PhD (Information Technology), North-West University, Vaal Triangle Campus, 2014
6

Rastreamento da m?xima pot?ncia utilizando o m?todo baseado na medi??o de temperatura com modula??o OCC digital

Leite, Alan C?ssio Queiroz Bezerra 26 June 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-08-01T12:09:06Z No. of bitstreams: 1 AlanCassioQueirozBezerraLeite_DISSERT.pdf: 6449528 bytes, checksum: 369bc54289511d188cd706add4d9379a (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-08-02T15:25:16Z (GMT) No. of bitstreams: 1 AlanCassioQueirozBezerraLeite_DISSERT.pdf: 6449528 bytes, checksum: 369bc54289511d188cd706add4d9379a (MD5) / Made available in DSpace on 2017-08-02T15:25:16Z (GMT). No. of bitstreams: 1 AlanCassioQueirozBezerraLeite_DISSERT.pdf: 6449528 bytes, checksum: 369bc54289511d188cd706add4d9379a (MD5) Previous issue date: 2017-06-26 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Os sistemas fotovoltaicos t?m se destacado entre os diferentes tipos de fontes de energia renov?veis por converterem diretamente a luz solar em eletricidade, apresentarem baixa manuten??o, bom rendimento na produ??o de eletricidade e n?o produzir gases do efeito estufa. Devido a algumas mudan?as clim?ticas de temperatura, radia??o e sombreamento no painel, a produ??o de eletricidade ? comprometida e isso provoca uma queda na efici?ncia de gera??o dos pain?is fotovoltaicos. Portanto, eles precisam de um sistema de rastreamento que fa?a o painel operar no ponto de m?xima pot?ncia. Esses sistemas de rastreamento s?o os chamados rastreadores de m?xima pot?ncia, ou do ingl?s Maximum Power Point Tracker - MPPT. O objetivo principal desse trabalho ? montar um sistema fotovoltaico controlado por um DSP TMS320F28335 e um conversor chaveado do tipo Boost, de modo que o sistema fa?a o rastreamento da m?xima pot?ncia do painel, maximizando sua efici?ncia. Neste trabalho ? implementada uma estrat?gia de controle baseada na medi??o da temperatura do painel para fornecer a tens?o de refer?ncia equivalente ao ponto de m?xima pot?ncia sob condi??es fora dos padr?es internacionais de testes e simulando efeitos de sombreamento das c?lulas fotovoltaicas, varia??es de temperatura e carga. De acordo com a temperatura lida pelo sensor LM35, o DSP TMS320F28335 ir? ajustar a tens?o de refer?ncia do controlador Proporcional Integral resultando em um valor de ciclo de trabalho do conversor Boost. O chaveamento do conversor Boost ser? feito utilizando a t?cnica de controle de um ciclo, One Cycle Control - OCC, ao inv?s da Modula??o por Largura de Pulso, a PWM. A t?cnica de chaveamento OCC fornece algumas vantagens frente ao PWM como uma r?pida resposta ? mudan?a de refer?ncia, erro nulo em regime e rejei??o de perturba??es na entrada. Foram feitos testes simulados variando condi??es clim?ticas de radia??o e temperatura e analisado o funcionamento do OCC em rela??o ao PWM. Os resultados experimentais mostram que o esquema baseado na medi??o de temperatura apresenta algumas vantagens em rela??o ao m?todo da Tens?o Constante utilizando a modula??o PWM. / Photovoltaic systems have stood out among the different types of renewable energy sources by directly converting sunlight into electricity, low maintenance, good performance in electricity production and do not produce greenhouse gases. Due to some climatic changes of temperature, radiation and shading on the panel, the production of electricity is compromised and this causes a decrease in the generation efficiency of the photovoltaic panels. Therefore, they need a tracking system that makes the panel operate at the maximum power point. These tracking systems are the so-called Maximum Power Point Tracker ? MPPT. The main objective of this work is to build a photovoltaic system controlled by a DSP TMS320F28335 and switched converter boost type, so that the system traces the maximum panel power, maximizing your efficiency. In this work a control strategy is implemented based on the panel temperature measurement to provide the reference voltage equivalent to the maximum power point under outside conditions of international testing standards and simulating shading effects of photovoltaic cells and temperature and load variations. According to the temperature read by the sensor LM35, the DSP TMS320F28335 will adjust the reference voltage of the PI controller resulting in a duty-cycle value of the Boost converter. The switch of the boost converter will be done using the control technique One Cycle Control ? OCC rather than the widely used PulseWidth Modulation ? PWM. The OCC switching technique provides some advantages over PWM as a quick response to the reference change, null error in steady state and rejection of input disturbances. Simulated tests were performed by varying the climatic conditions of radiation and temperature and analyzed the operation of the OCC in relation to the PWM. The experimental results show that the scheme based on temperature measurement has some advantages over the Constant Voltage method using PWM modulation.
7

Social Emotions in Multiagent Systems

Rincón Arango, Jaime Andrés 19 February 2018 (has links)
A lo largo de los últimos años, los sistemas multi-agente (SMA) han demostrado ser un paradigma potente y versátil, con un gran potencial a la hora de resolver problemas complejos en entornos dinámicos y distribuidos. Este potencial no se debe principalmente a sus características individuales (como son su autonomía, su capacidad de percepción, reacción y de razonamiento), sino que también a la capacidad de comunicación y cooperación a la hora de conseguir un objetivo. De hecho, su capacidad social es la que más llama la atención, es este comportamiento social el que dota de potencial a los sistemas multi-agente. Estas características han hecho de los SMA, la herramienta de inteligencia artificial (IA) más utilizada para el diseño de entornos virtuales inteligentes (IVE), los cuales son herramientas de simulación compleja basadas en agentes. Sin embargo, los IVE incorporan restricciones físicas (como gravedad, fuerzas, rozamientos, etc.), así como una representación 3D de lo que se quiere simular. Así mismo, estas herramientas no son sólo utilizadas para la realización de simulaciones. Con la aparición de nuevas aplicaciones como \emph{Internet of Things (IoT)}, \emph{Ambient Intelligence (AmI)}, robot asistentes, entre otras, las cuales están en contacto directo con el ser humano. Este contacto plantea nuevos retos a la hora de interactuar con estas aplicaciones. Una nueva forma de interacción que ha despertado un especial interés, es el que se relaciona con la detección y/o simulación de estados emocionales. Esto ha permitido que estas aplicaciones no sólo puedan detectar nuestros estados emocionales, sino que puedan simular y expresar sus propias emociones mejorando así la experiencia del usuario con dichas aplicaciones. Con el fin de mejorar la experiencia humano-máquina, esta tesis plantea como objetivo principal la creación de modelos emocionales sociales, los cuales podrán ser utilizados en aplicaciones MAS permitiendo a los agentes interpretar y/o emular diferentes estados emocionales y, además, emular fenómenos de contagio emocional. Estos modelos permitirán realizar simulaciones complejas basadas en emociones y aplicaciones más realistas en dominios como IoT, AIm, SH. / Over the past few years, multi-agent systems (SMA) have proven to be a powerful and versatile paradigm, with great potential for solving complex problems in dynamic and distributed environments. This potential is not primarily due to their individual characteristics (such as their autonomy, their capacity for perception, reaction and reasoning), but also the ability to communicate and cooperate in achieving a goal. In fact, its social capacity is the one that draws the most attention, it is this social behavior that gives potential to multi-agent systems. These characteristics have made the SMA, the artificial intelligence (AI) tool most used for the design of intelligent virtual environments (IVE), which are complex agent-based simulation tools. However, IVE incorporates physical constraints (such as gravity, forces, friction, etc.), as well as a 3D representation of what you want to simulate. Also, these tools are not only used for simulations. With the emergence of new applications such as \emph {Internet of Things (IoT)}, \emph {Ambient Intelligence (AmI)}, robot assistants, among others, which are in direct contact with humans. This contact poses new challenges when it comes to interacting with these applications. A new form of interaction that has aroused a special interest is that which is related to the detection and / or simulation of emotional states. This has allowed these applications not only to detect our emotional states, but also to simulate and express their own emotions, thus improving the user experience with those applications. In order to improve the human-machine experience, this thesis aims to create social emotional models, which can be used in MAS applications, allowing agents to interpret and / or emulate different emotional states, and emulate phenomena of emotional contagion. These models will allow complex simulations based on emotions and more realistic applications in domains like IoT, AIm, SH. / Al llarg dels últims anys, els sistemes multi-agent (SMA) han demostrat ser un paradigma potent i versàtil, amb un gran potencial a l'hora de resoldre problemes complexos en entorns dinàmics i distribuïts. Aquest potencial no es deu principalment a les seues característiques individuals (com són la seua autonomia, la seua capacitat de percepció, reacció i de raonament), sinó que també a la capacitat de comunicació i cooperació a l'hora d'aconseguir un objectiu. De fet, la seua capacitat social és la que més crida l'atenció, és aquest comportament social el que dota de potencial als sistemes multi-agent. Aquestes característiques han fet dels SMA, l'eina d'intel·ligència artificial (IA) més utilitzada per al disseny d'entorns virtuals intel·ligents (IVE), els quals són eines de simulació complexa basades en agents. No obstant això, els IVE incorporen restriccions físiques (com gravetat, forces, fregaments, etc.), així com una representació 3D del que es vol simular. Així mateix, aquestes eines no són només utilitzades per a la realització de simulacions. Amb l'aparició de noves aplicacions com \emph{Internet of Things (IOT)}, \emph{Ambient Intelligence (AmI)}, robot assistents, entre altres, les quals estan en contacte directe amb l'ésser humà. Aquest contacte planteja nous reptes a l'hora d'interactuar amb aquestes aplicacions. Una nova forma d'interacció que ha despertat un especial interès, és el que es relaciona amb la detecció i/o simulació d'estats emocionals. Això ha permès que aquestes aplicacions no només puguen detectar els nostres estats emocionals, sinó que puguen simular i expressar les seues pròpies emocions millorant així l'experiència de l'usuari amb aquestes aplicacions. Per tal de millorar l'experiència humà-màquina, aquesta tesi planteja com a objectiu principal la creació de models emocionals socials, els quals podran ser utilitzats en aplicacions MAS permetent als agents interpretar i/o emular diferents estats emocionals i, a més, emular fenòmens de contagi emocional. Aquests models permetran realitzar simulacions complexes basades en emocions i aplicacions més realistes en dominis com IoT, AIM, SH. / Rincón Arango, JA. (2018). Social Emotions in Multiagent Systems [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/98090 / TESIS
8

Les jeunes Aborigènes : le sport, les activités ludiques et les relations interraciales dans le Kimberley (Australie-Occidentale)

Marceau, Audrey 20 April 2018 (has links)
Ce mémoire porte un regard sur les dynamiques identitaires et relationnelles des jeunes Aborigènes du Kimberley – une région située au nord de l’Australie-Occidentale – plus précisément à Kununurra et à Kalumburu. Il résulte d’un pré-terrain (2010) et d’une recherche sur le terrain (2012). C’est à travers la pratique sportive, notamment le football australien (Australian Rules Football) et le basketball, ainsi que par les activités ludiques, dont la danse, que j’ai pu rendre compte des particularités de ces jeunes Aborigènes. D’autres sphères de leur vie ont aussi retenu mon attention, dont l’importance de la famille élargie dans les formes aborigènes de socialité et de solidarité, ainsi que les relations, souvent difficiles, avec la société dominante (les Euro-Australiens). À l’aide d’un survol socio-historique global mais aussi local – distinguant la vie semi-urbaine (Kununurra) versus la vie en communauté éloignée (Kalumburu) – il m’a été possible de déployer certains aspects de leur contemporanéité. / This Master’s thesis relate some relational dynamics of Aboriginal youth of the Kimberley – which is situated at the top end of Western Australia – specifically from Kununurra and Kalumburu. It results from a pre-fieldwork (2010) and a field research (2012). It is through sport, especially Australian football (Australian Rules Football) and basketball, as well as playful activities, including dance, that I could account for the peculiarities of these young Aborigines. Other spheres of their lives also caught my attention, mainly the importance of the extended family in aboriginal forms of sociality and solidarity, and relationships, often difficult, with the dominant society (Euro-Australians). Using an overview of the wide but also local socio-historical context – distinguishing the semi-urban life (Kununurra) versus remote community life (Kalumburu) – I could better explain various aspects of their contemporaneity.
9

Disintegration of packaging material:an experimental study of approaches to lower energy consumption

Upola, H. (Heikki) 31 January 2017 (has links)
Abstract The old corrugated container (OCC) recycling process produces pulp suspension from recovered packaging material with sufficient strength and cleanliness to meet regulatory requirements for produced packaging material. Pulping is the first unit operation in the OCC recycling process and the most energy-intensive unit operation, accounting for 20–30% of the total energy used in the process, if dispersion is not used. From the viewpoint of improving the energy efficiency of the OCC recycling process, the pulping stage is an important research target. The approach of this thesis work was to experimentally study practical possibilities to decrease the energy requirements of the OCC pulping process by understanding disintegration mechanisms and pulping fundamentals. The pulping process was conceptually divided into three separate phases: wetting, bulk disintegration, and residual disintegration. The aim was to elucidate the effect of each phase on disintegration kinetics and specific energy consumption of pulping, and to discuss how those phases could be intensified to minimize energy consumption. The results suggest that forced wetting of OCC material by mechanical pressing increases the disintegration rate owing to thorough impregnation of water into the OCC material, which efficiently reduces the material’s wet strength by cutting hydrogen bonds. The method can potentially reduce the energy requirement of the pulping process by about 30%. Bulk disintegration by falling the material in high-consistency drum pulping was emulated in a specially designed device. The results reveal that the energy needed for material disintegration depends significantly on the material’s wet strength. Pulping energy consumption can be lowered in the residual disintegration phase by separating the easily disintegrated weaker materials in an early stage from the drum and continuing pulping of the remaining non-disintegrated material (Fractional pulping). This setup led to estimated energy savings of around 20%. During the thesis work, the authors developed an analysis device that photographs flakes separated from the pulp and determines flake size distribution by image analysis. The device revealed the difference between the low- and medium-consistency OCC pulping mechanisms. / Tiivistelmä Pahvin kierrätysprosessissa kerätyistä pakkausmateriaaleista valmistetaan uusiomassaa, joka käytetään uuden pahvin valmistukseen. Kierrätysprosessin ensimmäinen yksikköoperaatio on pulpperointi eli pahviraaka-aineen kuiduttaminen sulpuksi. Pulpperointi on usein koko kierrätysprosessin energiankulutukseltaan suurin yksikköprosessi, joka voi viedä jopa 20 – 30 % koko prosessin energiankulutuksesta. Tämän vuoksi pulpperoinnin energiankulutuksen pienentämiseen tähtäävä tutkimus on erittäin tärkeää. Työn tarkoituksena oli tutkia kokeellisin menetelmin mahdollisuuksia vähentää pulpperoinnin energiankulutusta. Tavoitteena oli saada ymmärrystä pulpperoinnin hajotusmekanismeista ja pulpperointiin vaikuttavista tekijöistä. Tässä työssä pulpperointi jaettiin kolmeen vaiheeseen: pahvin vettymiseen, varsinaiseen bulkkihajotukseen ja jälkihajotukseen. Tarkoituksena oli havainnollistaa jokaisen vaiheen vaikutusta materiaalin hajotuskinetiikkaan ja pulpperoinnin energiankulutukseen. Lisäksi tavoitteena oli pohtia mahdollisia tapoja tehostaa jokaista vaihetta ja näin minimoida energiankulutusta. Tulosten perusteella pahvin pakotettu kostuttaminen mekaanisella puristuksella kasvattaa hajotusnopeutta johtuen vedestä, joka kastelee materiaalin läpikotaisin. Tämä pienentää materiaalin märkälujuutta katkomalla kuitujen välisiä vetysidoksia. Menetelmän avulla pulpperoinnin energiankulutusta pystytään vähentämään jopa 30 %. Rumpupulpperin bulkkihajotusta jäljiteltiin tarkoitukseen suunnitellulla pudotuslaitteella. Tulokset paljastivat, että energiatarve materiaalin hajottamiseen on verrannollinen materiaalin märkälujuuteen. Pulpperoinnin energiankulutusta jälkihajotuksessa voidaan pienentää ns. fraktioivalla pulpperoinnilla, jossa pulpperin kuormaa kevennetään poistamalla nopeasti hajoava heikkolujuuksinen materiaali mahdollisimman aikaisin, jonka jälkeen pulpperointia jatketaan hajoamattomalla materiaalilla. Tällaisella menetelmällä voidaan parhaimmillaan säästää 20 % rumpupulpperoinnin energiankulutuksesta. Työn aikana kehiteltiin myös kuvantamiseen perustuva analyysimenetelmä, jolla voidaan analysoida hajoamattoman materiaalin kokojakaumaa. Analyysimenetelmä paljasti hajotusmekanismieron matala- ja keskisakeuspulpperoinnin välillä.
10

Maintaining data consistency in embedded databases for vehicular systems

Gustafsson, Thomas January 2004 (has links)
The amount of data handled by real-time and embedded applications is increasing. This calls for data-centric approaches when designing embedded systems, where data and its metainformation (e.g., temporal correctness requirements) are stored centrally. The focus of this thesis is on efficient data management, especially maintaining data freshness and guaranteeing correct age on data. The contributions of our research are updating algorithms and concurrency control algorithms using data similarity. The updating algorithms keep data items up-to-date and can adapt the number of updates of data items to state changes in the external environment. Further, the updating algorithms can be extended with a relevance check allowing for skipping of unnecessary calculations. The adaptability and skipping of updates have positive effects on the CPU utilization, and freed CPU resources can be reallocated to, e.g., more extensive diagnosis of the system. The proposed multiversion concurrency control algorithms guarantee calculations reading data that is correlated in time. Performance evaluations show that updating algorithms with a relevance check give significantly better performance compared to well-established updating approaches, i.e., the applications use more fresh data and are able to complete more tasks in time. The proposed multiversion concurrency control algorithms perform better than HP2PL and OCC and can at the same time guarantee correct age on data items, which HP2PL and OCC cannot guarantee. Thus, from the perspective of the application, more precise data is used to achieve a higher data quality overall, while the number of updates is reduced. / <p>Report code: LiU-Tek-Lic-2004:67.</p>

Page generated in 0.0487 seconds