Nos últimos anos, a crescente demanda por alto desempenho tem favorecido o surgimento de arquiteturas e algoritmos cada vez mais eficientes. A popularidade das plataformas distribuídas levanta novas questões no desenvolvimento de algoritmos paralelos tais como comunicação, heterogeneidade e dinamismo de recursos. Estas questões podem resultar em aplicações com carga de trabalho conhecida somente em tempo de execução. A irregularidade do algoritmo ou da entrada de dados também pode influenciar na carga de trabalho da aplicação. Uma aplicação paralela pode solucionar estas questões por meio de algoritmos dinâmicos ao utilizar técnicas de programação que definam o trabalho de uma tarefa e possibilitem a utilização de recursos sob demanda. A granularidade, que é a razão entre processamento e comunicação, considera questões práticas de execução e é um fator importante no desempenho de algoritmos dinâmicos. A implementação de um controle de granularidade é complicada e depende do suporte dos ambientes de programação. Porém, os ambientes de programação possuem interfaces extensas e complicadas que dificultam sua utilização em PAD. Este trabalho propõe a implementação de uma biblioteca (libSpawn) que incorpora um controle de granularidade em aplicações MPI dinâmicas. A biblioteca controla a granularidade ao mapear tarefas entre processos ou threads de acordo com três parâmetros: cores da arquitetura, carga e recursos de sistema. Os tempos obtidos com processos e libSpawn demonstram ganhos significativos em benchmarks sintéticos utilizados por outros ambientes de programação. Não obstante, constata-se carências na implementação atual que produzem tempos anômalos, ainda que estes sejam insignificantes em relação aos tempos com processos. / In the last years, the demand for high performance enables the emergence of more efficient computing platforms and algorithms. The increase of distributed computing platforms rises new challenges for parallel algorithm development like communication, heterogeneity, and resource management. These factors can result in applications whose work load is unknown until runtime. An irregular behavior from algorithm or data can also affect the work load. A parallel application can solve these questions through a programming technique which predicts the work load of a task and offers resource on demand. The granularity, which is the ratio of computation to communication, considers more practical issues, and is an important factor in performance of dynamic algorithms. However, this control is difficult to be designed and the support of a programming tool is needed. Yet, the programming tools have extensive and complicated interfaces which difficult your usage in HPC. This work implements a library (libSpawn) which adds a granularity control on MPI dynamic programs. The library controls the granularity by mapping tasks between processes or threads with three parameters: cores of architecture, load and resources of the operating system. The results obtained between processes and libSpawn show significant gains on synthetic benchmarks from other programming tools.

abstract: Blur is an important attribute in the study and modeling of the human visual system. In this work, 3D blur discrimination experiments are conducted to measure the just noticeable additional blur required to differentiate a target blur from the reference blur level. The past studies on blur discrimination have measured the sensitivity of the human visual system to blur using 2D test patterns. In this dissertation, subjective tests are performed to measure blur discrimination thresholds using stereoscopic 3D test patterns. The results of this study indicate that, in the symmetric stereo viewing case, binocular disparity does not affect the blur discrimination thresholds for the selected 3D test patterns. In the asymmetric viewing case, the blur discrimination thresholds decreased and the decrease in threshold values is found to be dominated by the eye observing the higher blur. The second part of the dissertation focuses on texture granularity in the context of 2D images. A texture granularity database referred to as GranTEX, consisting of textures with varying granularity levels is constructed. A subjective study is conducted to measure the perceived granularity level of textures present in the GranTEX database. An objective index that automatically measures the perceived granularity level of textures is also presented. It is shown that the proposed granularity metric correlates well with the subjective granularity scores and outperforms the other methods presented in the literature. A subjective study is conducted to assess the effect of compression on textures with varying degrees of granularity. A logarithmic function model is proposed as a fit to the subjective test data. It is demonstrated that the proposed model can be used for rate-distortion control by allowing the automatic selection of the needed compression ratio for a target visual quality. The proposed model can also be used for visual quality assessment by providing a measure of the visual quality for a target compression ratio. The effect of texture granularity on the quality of synthesized textures is studied. A subjective study is presented to assess the quality of synthesized textures with varying levels of texture granularity using different types of texture synthesis methods. This work also proposes a reduced-reference visual quality index referred to as delta texture granularity index for assessing the visual quality of synthesized textures. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2015

Nos últimos anos, a crescente demanda por alto desempenho tem favorecido o surgimento de arquiteturas e algoritmos cada vez mais eficientes. A popularidade das plataformas distribuídas levanta novas questões no desenvolvimento de algoritmos paralelos tais como comunicação, heterogeneidade e dinamismo de recursos. Estas questões podem resultar em aplicações com carga de trabalho conhecida somente em tempo de execução. A irregularidade do algoritmo ou da entrada de dados também pode influenciar na carga de trabalho da aplicação. Uma aplicação paralela pode solucionar estas questões por meio de algoritmos dinâmicos ao utilizar técnicas de programação que definam o trabalho de uma tarefa e possibilitem a utilização de recursos sob demanda. A granularidade, que é a razão entre processamento e comunicação, considera questões práticas de execução e é um fator importante no desempenho de algoritmos dinâmicos. A implementação de um controle de granularidade é complicada e depende do suporte dos ambientes de programação. Porém, os ambientes de programação possuem interfaces extensas e complicadas que dificultam sua utilização em PAD. Este trabalho propõe a implementação de uma biblioteca (libSpawn) que incorpora um controle de granularidade em aplicações MPI dinâmicas. A biblioteca controla a granularidade ao mapear tarefas entre processos ou threads de acordo com três parâmetros: cores da arquitetura, carga e recursos de sistema. Os tempos obtidos com processos e libSpawn demonstram ganhos significativos em benchmarks sintéticos utilizados por outros ambientes de programação. Não obstante, constata-se carências na implementação atual que produzem tempos anômalos, ainda que estes sejam insignificantes em relação aos tempos com processos. / In the last years, the demand for high performance enables the emergence of more efficient computing platforms and algorithms. The increase of distributed computing platforms rises new challenges for parallel algorithm development like communication, heterogeneity, and resource management. These factors can result in applications whose work load is unknown until runtime. An irregular behavior from algorithm or data can also affect the work load. A parallel application can solve these questions through a programming technique which predicts the work load of a task and offers resource on demand. The granularity, which is the ratio of computation to communication, considers more practical issues, and is an important factor in performance of dynamic algorithms. However, this control is difficult to be designed and the support of a programming tool is needed. Yet, the programming tools have extensive and complicated interfaces which difficult your usage in HPC. This work implements a library (libSpawn) which adds a granularity control on MPI dynamic programs. The library controls the granularity by mapping tasks between processes or threads with three parameters: cores of architecture, load and resources of the operating system. The results obtained between processes and libSpawn show significant gains on synthetic benchmarks from other programming tools.

Submitted by Haroudo Xavier Filho (haroudo.xavierfo@ufpe.br) on 2016-03-11T14:47:26Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) ONTOER+ Final.pdf: 7209205 bytes, checksum: fe6acd91293a1dd34f5ffe3a04d42c21 (MD5) / Made available in DSpace on 2016-03-11T14:47:26Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) ONTOER+ Final.pdf: 7209205 bytes, checksum: fe6acd91293a1dd34f5ffe3a04d42c21 (MD5) Previous issue date: 2015-05-29 / FACEPE / A facilidade de acesso e comunica#!o proporcionada pela Internet contribuiu para o surgimento de novas solu#'es, como as baseadas em Objetos de Aprendizagem, com o intuito de facilitar ainda mais o compartilhamento de conte*dos educacionais dispon(veis na Web. Os Recursos Educacionais Abertos +REA/ s!o objetos de aprendizagem disponibilizados por meio de licen#as de copyright, para qualquer usu%rio usar livremente, sendo *teis para o aprendizado de alunos dos ensinos a dist3ncia e presencial. Em geral, os REA quase sempre s!o encontrados em formatos que n!o permitem ao usu%rio utilizar apenas as partes desejadas. Por&m, disponibilizar as partes que comp'em o REA & de fundamental import3ncia para facilitar o seu re*so. Tomando como exemplo uma publica#!o do tipo artigo, este seria disponibilizado separando suas se#'es, par%grafos, figuras e tabelas. Neste contexto, este trabalho descreve o desenvolvimento de uma ontologia para o dom(nio de REA, a qual permite n!o apenas a representa#!o do REA como um todo, mas tamb&m a representa#!o de partes do conte*do dos recursos. Para facilitar o entendimento do uso de REA pelos usu%rios podem ser usadas ontologias, as quais objetivam melhor organizar o conhecimento comum de dom(nios espec(ficos. A ontologia de dom(nio dos REA aqui descrita, nomeada de ONTOER4, & baseada em metadados e descri#!o de conte*do, o que facilita o entendimento para se obter um n(vel de granularidade menor, uma das caracter(sticas de fragmenta#!o dos REA. Para guiar o processo de desenvolvimento da ontologia, uma metodologia, denominada Methontology, foi adotada. / Ease of access and communication provided by the Internet contributed to the emergence of new solutions such as those based on Learning Objects, in order to further facilitate the sharing of educational content available on the Web. Open Educational Resources +OER/ are learning objects available through copyright licenses for any user to use freely and are useful for learning to students from distance and classroom teaching. Generally, OER are almost always found in formats that do not allow the user to use only any portions of it. However, to provide the component parts of the OER is extremely important to facilitate their reuse. Taking as an example a publication of the article type, this would be made available by separating its sections, paragraphs, figures and tables. In this context, this work describes the development of an ontology for OER domain, which allows not only the representation of the OER as a whole, but also the representation of pieces of content resources. Ontology can be used to facilitate the understanding of the use of OER by users, which aims at better organizing common knowledge of specific areas. The domain ontology OER described herein, named ONTOER4, is based on metadata and content description, which facilitates understanding how to obtain a lower level of granularity, one of fragmentation characteristics of OER. To guide the ontology development process, a method called Methontology was adopted.

Pour utiliser la puissance de calcul des ordinateurs modernes, nous devons écrire des programmes concurrents. L’écriture de programme concurrent efficace est notoirement difficile, principalement en raison de la nécessité de gérer les coûts de synchronisation. Dans cette thèse, nous nous concentrons sur les coûts de synchronisation dans les programmes parallèles et les structures de données concurrentes.D’abord, nous présentons une nouvelle technique de contrôle de la granularité pour les programmes parallèles conçus pour un environnement de multi-threading dynamique. Ensuite, dans le contexte des structures de données concurrentes, nous considérons la notion d’optimalité de concurrence (concurrency-optimality) et proposons la première implémentation concurrence-optimal d’un arbre binaire de recherche qui, intuitivement, accepte un ordonnancement concurrent si et seulement si l’ordonnancement est correct. Nous proposons aussi la combinaison parallèle (parallel combining), une technique qui permet l’implémentation efficace des structures de données concurrences à partir de leur version parallèle par lots. Nous validons les techniques proposées par une évaluation expérimentale, qui montre des performances supérieures ou comparables à celles des algorithmes de l’état de l’art.Dans une perspective plus formelle, nous considérons le phénomène d’assistance (helping) dans des structures de données concurrentes. On observe un phénomène d’assistance quand l’ordre d’une opération d’un processus dans une trace linéarisée est fixée par une étape d’un autre processus. Nous montrons qu’aucune implémentation sans attente (wait-free) linéarisable d’une pile utilisant les primitives read, write, compare&swap et fetch&add ne peut être “sans assistance” (help-free), corrigeant une erreur dans une preuve antérieure de Censor-Hillel et al. Finalement, nous proposons une façon simple de prédire analytiquement le débit (throughput) des structures de données basées sur des verrous à gros grains. / To use the computational power of modern computing machines, we have to deal with concurrent programs. Writing efficient concurrent programs is notoriously difficult, primarily due to the need of harnessing synchronization costs. In this thesis, we focus on synchronization costs in parallel programs and concurrent data structures.First, we present a novel granularity control technique for parallel programs designed for the dynamic multithreading environment. Then in the context of concurrent data structures, we consider the notion of concurrency-optimality and propose the first implementation of a concurrency-optimal binary search tree that, intuitively, accepts a concurrent schedule if and only if the schedule is correct. Also, we propose parallel combining, a technique that enables efficient implementations of concurrent data structures from their parallel batched counterparts. We validate the proposed techniques via experimental evaluations showing superior or comparable performance with respect to state-of-the-art algorithms.From a more formal perspective, we consider the phenomenon of helping in concurrent data structures. Intuitively, helping is observed when the order of some operation in a linearization is fixed by a step of another process. We show that no wait-free linearizable implementation of stack using read, write, compare&swap and fetch&add primitives can be help-free, correcting a mistake in an earlier proof by Censor-Hillel et al. Finally, we propose a simple way to analytically predict the throughput of data structures based on coarse-grained locking

The purpose of this thesis is to explore how to enable forward traceability of textile and fashion products at product level, using BC based traceability solutions. The study finds that within TC industry, forward traceability using available technologies (RFIDs, NFCs, QR codes ) is technically possible, however there could be impending regulatory, legal, technical implications of using these technologies. These implications may result in a slew of added compliance requirements, risk assessments and resources allocations from brands and retailers. As a result, this study uncovered that using QR codes with BC technology offers a suitable forward traceability solution which has the potential to set off most of the implications explored during this study. Moreover, to attain forward traceability at product levels, a complete mechanism involving readiness from customers, suppliers and all other stake holders is required. All these stake holders need to be connected to the central BC network, where data is protected and made tamper proof. Lastly, forward tracing at product levels is a futuristic concept, as TC industry is still majorly focused on the backward traceability, however this study finds that forward traceability at product levels may pave its way as a beneficial component of overall sustainability.

Waiting for service is inevitable. Service cannot be easily supplied to match fluctuating peaks of demand, and its pre-production is limited. Unfortunately, however, most people do not tolerate waiting well. To effectively deal with the inevitable waiting, service organizations endeavor to manage customer perceptions of the wait using various strategies to make waiting seem short and less wasteful and uncomfortable. Therefore, finding ways to manage customer perceptions of waiting is an essential part of the service experience. To encourage customers to join in and help them remain being patient, service operations provide estimated waiting time. Information on the estimated wait time affects customer expectations and responses, which may further lead to undesirable customer behaviors such as balking (i.e., refusal to wait in line) and reneging (i.e., give up to get the service and leave away from the line). That is, customers’ understanding of quantitative meanings often deviates from the objective value even when the estimated waiting time is well delivered. Therefore, how service providers structure and deliver quantitative information causes customers to differ in their estimation of the time to be waitlisted as well as the expectation of service promptness, and eventually determine their behaviors. Existing research, however, has overlooked how customer experience of waiting is altered by the wait time is communicated as part of strategies for managing waiting for services. While waiting, people will have quantitative information for the duration in both numbers and units. Thus, granularity and its effect on customers’ affective and cognitive responses as well as their waiting behaviors (i.e., joining in, keep staying on, or leaving away from the line) require further investigation in that numbers and units are inseparable and change simultaneously. The purpose of this study was to explore how information, through various psychological mechanisms both cognitive and affective responses, affects waiting behavior. This dissertation consisted of three studies. Study 1 was conducted to investigate how information on delays have a granularity effect on customer perceptions of time estimation for being waitlisted in numerical cognition, particularly depending on its format. Study 2 further explored the effect of information on waiting with communicator’s cooperativeness on balking behavior, and that are incorporated into expectation of the service promptness and anxiety as a part of cognitive and affective responses. Finally, Study 3 examined the effect of information on time delays on reneging behavior with customer mind-sets with matching of cognitive salience of unit (verse number), especially when delays are imposed by the wait staff, and that are incorporated into understanding psychological mechanisms (information processing fluency and anxiety). Study 1 found that providing waiting information in a coarse-grained unit with an interval is not ideal for customers assured to join a queue because they less expected the time on being waitlisted far less shortly. In general, less balking occurs if information is delivered as a single value (than an interval), even the information is delivered in a coarse-grained unit. Therefore, for an in-depth understanding of the granularity effect of information on waiting to be seated, Study 2 was narrowed to use only a single value. Study 2 showed that when information is delivered in a coarse-grained unit with a point estimate by a professionally trained employee, balking is far less common than if the same information is delivered by an unprofessional employee because the professional employee elicits a higher level of expectation of service promptness. With emphasizing the role of the employees, how employees deliver the information in point estimate professionally encourages customers to less balking or more joining a queue even if the information is delivered in a coarse-grained unit (i.e., hours). Finally, Study 3 revealed that more reneging occurred when additional wait time was communicated in a coarse-grained interval than when the wait time was delivered in a fine-grained interval. Furthermore, when the additional wait time was communicated using a coarse-grained (rather than a fine-grained) interval to customers with an abstract mind-set, they felt more anxious and subsequently were more likely to renege. During sequential delays, therefore, information on waiting could be framed at a concrete level (how-laden) to reduce anxiety and further to keep customers stay in line. The insight gained from the three studies is discussed, and theoretical and practical implications presented in conclusion. / Tourism and Sport

[pt] As fontes renováveis de energia tem adquirido grande relevância no contexto mundial devido as diretrizes tomadas pelas políticas globais. Embora sejam termoelétricas, as usinas a biomassa são consideradas fontes de energia renováveis por manter os níveis de gás carbônico na atmosfera. Além disso, as usinas termoelétricas têm mais autonomia na geração do que as demais fontes renováveis como hidrelétricas, eólicas e solares que dependem de incertezas como vazões de água, velocidade do vento e irradiação solar, respectivamente. Este conjunto de características torna a biomassa uma fonte de energia indispensável para futuros planejamentos de operação do sistema. No entanto, esta fonte apresenta períodos intermitentes por estar usualmente atrelada a cultura de cana-de-açúcar. Poucos são os estudos de previsão e simulação desta fonte de energia. Dessa forma, a dissertação visa a implementação do modelo de cadeias de Markov com simulações de Monte Carlo. / [en] Renewable energy sources have acquired great relevance in the world context due to the guidelines taken by global policies. Although they are thermoelectric, biomass power plants are considered renewable energy sources because they maintain the levels of carbon dioxide in the atmosphere. In addition, thermoelectric plants have more autonomy in generation than other renewable sources such as hydro, wind and solar, which depend on uncertainties such as water flow, wind speed and solar irradiation, respectively. This set of characteristics makes biomass an indispensable energy source for future system operation planning. However, this source has intermittent periods as it is usually linked to the sugarcane crop. There are few prediction and simulation studies of this energy source. Thus, the dissertation aims to implement the Markov chain model with Monte Carlo simulations.

yes / A two dimensional (2D) RNG k-ε sediment model including the effects of secondary currents is developed to simulate sediment transport and bed deformation in rivers with continuous bends. Nonuniform suspended and bedload sediment transports and variation of effective bed material size distribution are included in the model. A semi-coupled scheme for sediment model is proposed, which can be used for simulating both the long- and short-term sediment transport whenever riverbed changes. The model is applied to simulate the flow and sediment transport in the Shapotou reservoir in the upper reach of the Yellow River which is a typical natural river reach with continuous bends. River bed deformations caused by suspended and bedload sediment transport are investigated. Good agreement between the numerically simulated results and the field measurements is obtained, indicating that the model is capable of simulating the sediment transport and predicting the bed deformation of rivers having continuous bends with reasonable accuracy. / the Major Research Plan Project, National Natural Science Foundation of China(Grant No.: 91230111 and 51279071); National Key BasicResearch Development Program of China (973 Program, Grant No.: 2010CB429002);Project of Science and Technology of Colleges in Ningxia, China (Grant No.:NGY2012097)

Learning objects have received attention because of their potential to improve current methods of teaching and learning. Despite perceived importance, there has been lack of studies that examine the use of learning objects across various contexts. In response, this study examined the actual use of learning objects and their perceptions among Instructional Design and Technology (IDT) practitioners in U.S. This study was based on the data from 191 IDT practitioners from various sectors, including higher education, business, government, and K-12. The study results contribute to the body of knowledge on learning objects in terms of four areas: conceptualization, utilization, benefits, and adoption. First, the study results should allay the concern that the conceptualization of learning objects focuses too much on technical aspects. IDT practitioners emphasized both technical and learning aspects in conceptualizing learning objects. In conclusion, the present study laid the foundation for a working definition of learning objects. Second, the study showed that IDT practitioners were utilizing learning objects to empower learners to have control over their own learning. The current study identified design strategies that IDT practitioners were frequently using. The most frequently utilized strategy was the provision of concrete, authentic examples and problems. Along with design strategies, this study identified the frequently adopted granularity levels: assets, combined media, one complete instructional unit, lesson or module, and course. Combined media, which consists of content and optional media, was the most frequently utilized granularity level of the five levels. The study provided empirical data to help determine formal design strategies and optimal granularity levels in utilizing learning objects based on the frequent use among IDT practitioners. Third, this study filled the research gap on the benefits of learning objects from an IDT perspective. Study results showed that IDT practitioners were positive about the overall benefits for the ID process, along with reusability and the support for the motivation and interactivity features. However, they were less convinced of the time and cost savings. Generally, IDT practitioners were satisfied with the benefits of learning objects. Fourth, the present study improved the understanding of the adoption status of learning objects. Currently, many of the participants' organizations were adopting or exploring the implementation of learning objects. The adoption of learning objects has a promising future, as IDT practitioners were positive about their organizations' intentions to use learning objects in the future. At the individual level, IDT practitioners were found to use learning objects for their professional role and across various projects. As an adoption factor, IDT practitioners showed the positive reactions to learning objects' perceived usefulness. / Ph. D.