Nos últimos anos, computação em grade tem emergido como uma forma de utilização de recursos geograficamente distribuídos em múltiplas organizações. Devido ao fato de grids serem altamente distribuídos e compostos por recursos heterogêneos, a computação em grade tem dado importância a requisitos específicos, como escalabilidade, desempenho e a necessidade de um modelo de programação adequado. Vários modelos de programação já foram propostos para a computação em grade. Entretanto, ate agora, nenhum deles supriu todos os requisitos. Diferentemente, na área de alto desempenho em clusters, o modelo de passagem de mensagens se tornou um verdadeiro padrão com um grande número de bibliotecas e aplicações legadas. Este trabalho propõe um framework híbrido que combina os altos desempenho e aceitação do padrão MPI, melhorado com extensões intuitivas para permitir aos desenvolvedores o projeto e desenvolvimento de aplicações em grade ou a gridi-ficação de aplicações já existentes, com a flexibilidade de um runtime baseado em componentes, modelando uma hierarquia de recursos e suportando a comunicação entre clusters. A solução proposta se baseia na adição de comunicadores MPI e uma API relacionada, a qual oferece um suporte ao desenvolvimento de aplicações que levam em conta a topologia hierárquica de grades computacionais, adequado a desenvolvedores habituados a MPI. características (Simula_c~ao Baseada no Algoritmo de Monte Carlo, Mergesort e um solver Poisson3D) mostraram que a gridificação pode melhorar consideravelmente o desempenho dessas aplicações em ambientes de grade. Ainda que o objetivo deste trabalho não seja competir com distribuições MPI existentes, o desempenho da solução proposta _e comparável ao desempenho de MPI, sendo melhor em alguns casos. A partir dos resultados obtidos com o protótipo apresentado, é possível concluir que o custo adicionado pela utilização de componentes não é desprezível, mas dentro do esperado. Entretanto, espera-se que os benefícios para aplicações de grade devem superar os custos adicionais. Além disso, as extensões a interface MPI oferecem a usuários as abstrações necessárias ao projeto de algoritmos paralelos de forma hierárquica, visando ambientes de grade. / In the past several years, grid computing has emerged as a way to harness computing resources geographically distributed across multiple organizations. Due to its inherently largely distributed and heterogeneous nature, grid computing has enlarged the importance of specific requirements, such as scalability, performance and the need of an adequate programming model. Several programming models have been proposed for grid programming. Nonetheless, so far, none of them met all the requirements. Differently, in the field of high performance cluster computing, the message passing model became a true standard with a large number of libraries and legacy applications. This work proposes a hybrid framework that combines the high performance and high acceptability of the MPI standard boosted with intuitive extensions to enable developers to design grid applications or "gridify" existing ones with the flexibility of a component-based runtime modeling resources hierarchy and offering support to inter-cluster communication. The proposed solution relies on the addition of new MPI communicators and a related API, which may offer a support well-suited to programmers used to MPI in order to reflect a hierarchical topology within the deployed application. Carlo Simulation, a Mergesort and a Poissond3D solver) have shown that the "gridification" of applications improve application performance on grid environments. Even if the goal is not to compete against existing MPI distributions, the performance of the solution is comparable with MPI performance, even better in some cases. From the results obtained in the evaluation of this prototype, we conclude that the overhead introduced by the components is not negligible, but inside of the expected. However, we can expect the benefits to grid applications to bypass the generated overhead. Besides, the extended interface may offer users the adequate abstractions to design parallel algorithms in a hierarchical way addressing grid environments.

Dans cette thèse nous étudions l’isolation mémoire et les mesures de communications efficaces par passage de message dans le contexte des environnements à mémoire partagée et la programmation orientée-objets. L’état de l’art en la matière se base presque exclusivement sur deux techniques complémentaires dites de propriété des objets (ownership) et d’unicité de références (reference uniqueness) afin d’adresser les problèmes de sécurité dans les programmes concurrents. Il est frappant de constater que la grande majorité des travaux existants emploient des méthodes de vérification statique des programmes, qui requirent soit un effort d’annotations soit l’introduction de fortes contraintes sur la forme et les références vers messages échangés. Notre contribution avec SIAAM est la démonstration d’une solution d’isolation réalisée uniquement à l’exécution et basée sur le modèle de programmation par acteurs. Cette solution purement dynamique ne nécessite ni annotations ni vérification statique des programmes. SIAAM permet la communication sans copie de messages de forme arbitraire. Nous présentons la sémantique formelle de SIAAM ainsi qu’une preuve d’isolation vérifiée avec l’assistant COQ. L’implantation du modèle de programmation pour le langage Java est réalisé dans la machine virtuelle JikesRVM. Enfin nous décrivons un ensemble d’analyses statiques qui réduit automatiquement le cout à l’exécution de notre approche. / In this thesis we study state isolation and efficient message-passing in the context of concurrent object-oriented programming. The ’ownership’ and ’reference uniqueness’ techniques have been extensively employed to address concurrency safety in the past. Strikingly the vast majority of the previous works rely on a set of statically checkable typing rules, either requiring an annotation overhead or introducing strong restrictions on the shape and the aliasing of the exchanged messages.Our contribution with SIAAM is the demonstration of a purely runtime, actor-based, annotation-free, aliasing-proof approach to concurrent state isolation allowing efficient communication of arbitrary objects graphs. We present the formal semantic of SIAAM, along with a machine-checked proof of isolation. An implementation of the model has been realized in a state-of-the-art Java virtual-machine and a set of custom static analyses automatically reduce the runtime overhead.

This diploma thesis focuses on the analysis of the conditions of lighter-skin black women of mixed ancestry, both free and enslaved, before and after emancipation, as related in four novels written by the 19th century African-American novelists: Hannah Crafts, Harriet E. Wilson, Julia C. Collins and Frances E. W. Harper. The work especially deals with the main motifs appearing in their novels, such as the interracial relationships, variations of racism toward mulattos, the problematics of ``passing{\crqq} for white and the issue of ``racial uplift{\crqq}. The analyses of the novels themselves are preceded by a survey of the authors´ lives since they drew inspiration from their own personal experience. This is followed by a brief conclusive comparison of their novels.

Em ambientes de desastre urbano, grupos de agentes de resgate devem resolver tarefas de modo a minimizar os danos que podem ocorrer na cidade. Tais ambientes são dinâmicos e parcialmente observáveis, com características que dizem respeito à distância espacial, quantidade de recursos, à dificuldade da tarefa de desastre e à capacidade do agente de atendê-la. A comunicação entre os agentes pode ser ruidosa ou inexistente. Os sistemas multiagente são desenvolvidos para resolver problemas complexos e abrangentes, que estão além da capacidade de um único agente. Nesse contexto, os agentes são elementos computacionais autônomos que são responsáveis por uma parte da solução do problema. Os agentes são situados em um ambiente e podem ter habilidade social, interagindo com outros agentes para resolver as tarefas. Comumente, o domínio de desastre urbano é formalizado como um problema de alocação de tarefas e modelado como um problema de otimização de restrições distribuídas entre agentes heterogêneos, onde eles têm que escolher as tarefas que maximizam suas utilidades individuais ou minimizem seus custos individuais. Essa dissertação de mestrado propõe um modelo para formação de grupos de agentes baseado na minimização de uma métrica de distância. O modelo é formalizado como um problema de otimização de restrições distribuídas, usando algoritmos para troca de mensagens entre os agentes. O modelo chamado Formação de Grupos pela Minimização da Distância (FGMD) tem agentes autônomos que tem a capacidade de se auto-organizar sem a necessidade de um controle centralizado. Aplicamos o FGMD na plataforma RMASBench, que é um simulador para situações de desastre urbano. Comparou-se o FGMD com os algoritmos mais recentes de passagem de mensagens, tendo sido verificado que o FGMD use menos computação não-paralela. Com respeito a minimização dos danos na cidade, mostrou-se que é possível obter resultados melhores que as abordagens do estado-da-arte com leve aumento no esforço computacional. / In urban disaster environments, groups of rescue agents must solve tasks in order to minimize the damage that can occur in a city. Such environments are dynamic and partially observable, with features that correspond to spatial distance, amount of resources, difficulty of the disaster task, and the capability of the agent to handle it. The communication between the agents can be noisy or non-existent. Multiagent systems are developed to solve complex and comprehensive problems, that are beyond the capability of one single agent. In this context, the agents are autonomous computational elements that are responsible for a piece of the solution of the problem. The agents are situated in an environment, and may have social ability, interacting with other agents to solve the tasks. Commonly, the urban disaster domain is formalized as a task allocation problem, and modelled as a constraint optimization problem distributed among heterogeneous agents, where they have to choose the tasks that maximize their individual utilities or minimize their individual costs. This master thesis proposes a model for formation of groups of agents based in the minimization of a distance. The model is formalized as a distributed constraint optimization problem, using algorithms to exchange messages between agents. The model called Formation of Groups by Minimization of Distance (FGMD) has self-organizing autonomous agents without a centralized control. We applied the FGMD in the RMASBench platform, that is a simulator for urban disaster situations. We compare the FGMD with the most recent message passing algorithms, verifying that FGMD uses less non-parallel computation. With respect to the minimization of the damage in the city, we show that it is possible to obtain better results than the state-of-art approaches, with slightly increase of computational effort.

In this thesis project we have successfully added an MPI extension layer to the LOIS framework. The framework defines an infrastructure for executing and connecting continuous stream processing applications. The MPI extension provides the same amount of stream based data as the framework’s original transport. We assert that an MPI-2 compatible implementation can be a candidate to extend the given framework with an adaptive and flexible communication sub-system. Adaptability is required since the communication subsystem has to be resilient to changes, either due to optimizations or system requirements.

The advent of social media enabled sexual minorities, as LGBTQ+ people, to find a community online. However, it can be difficult for transgender people to express their gender identity without risking a form of social injustice, as transgender people are not included in the prevailing gender binary. This thesis explores how transgender people present gender on the hashtag #TransIsBeautfiul on Instagram and to what extent to what extent can a form of ‘passing’ be seen in how transgender people adhere to expressing societal gender norms. Goffman’s (1979) theory on gender display is adapted as a main framework to analyse 346 posts with a qualitative content analysis. The theories of gender display (1979) and self-presentation (1956) by Goffman and the concept of passing by Serano (2007) are also employed for a deeper understanding of the social construction of gender. Findings show a great diversity of gender self-presentations. Transgender people tend to express their masculinity and femininity in an exaggerated way, by emphasizing certain masculine and feminine aspects according to societal gender norms and therefore ‘pass’ as a ‘natural’ member of the gender binary. In complete contrast, there are also transgender people who challenge the gender binary by expressing themselves as non-binary. They represent themselves within and outside the gender binary by mixing and minimizing feminine and masculine aspects. These results show that for transgender people there are two ways of coping with societal gender norms and put the gender binary model into question.

Survey propagation (SP) has recently been discovered as an efficient algorithm in solving classes of hard constraint-satisfaction problems (CSP). Powerful as it is, SP is still a heuristic algorithm, and further understanding its algorithmic nature, improving its effectiveness and extending its applicability are highly desirable. Prior to the work in this thesis, Maneva et al. introduced a Markov Random Field (MRF) formalism for k-SAT problems, on which SP may be viewed as a special case of the well-known belief propagation (BP) algorithm. This result had sometimes been interpreted to an understanding that “SP is BP” and allows a rigorous extension of SP to a “weighted” version, or a family of algorithms, for k-SAT problems. SP has also been generalized, in a non-weighted fashion, for solving non-binary CSPs. Such generalization is however presented using statistical physics language and somewhat difficult to access by more general audience. This thesis generalizes SP both in terms of its applicability to non-binary problems and in terms of introducing “weights” and extending SP to a family of algorithms. Under a generic formulation of CSPs, we first present an understanding of non-weighted SP for arbitrary CSPs in terms of “probabilistic token passing” (PTP). We then show that this probabilistic interpretation of non-weighted SP makes it naturally generalizable to a weighted version, which we call weighted PTP. Another main contribution of this thesis is a disproof of the folk belief that “SP is BP”. We show that the fact that SP is a special case of BP for k-SAT problems is rather incidental. For more general CSPs, SP and generalized SP do not reduce from BP. We also established the conditions under which generalized SP may reduce as special cases of BP. To explore the benefit of generalizing SP to a wide family and for arbitrary, particularly non-binary, problems, we devised a simple weighted PTP based algorithm for solving 3-COL problems. Experimental results, compared against an existing non-weighted SP based algorithm, reveal the potential performance gain that generalized SP may bring.

[EN] The quality of traffic on two-lane roads is closely linked to the possibility of making the overtaking maneuver that is especially critical in addition to the level of risk posed to do it. Options to facilitate overtaking are providing a path with geometric conditions for overtaking can be performed on the road with enough opportunities or provide a cross section that facilitates this advancement by auxiliary lanes. In this research, the second option with passing and climbing lanes was discussed. To characterize the passing maneuver on steep grades an experimental study that allowed access to data and important information for calibrating TWOPAS, a microscopic traffic simulation model of two-lane roads, which is main element of the Traffic Analysis Module (TAM) that integrates the Interactive Highway Safety Design Model (IHSDM) was developed. TWOPAS was validated in other two-lane road with very different characteristics to the road considered during calibration thereby evaluating the usefulness of this simulation model was completed. Considering a target of this research the TWOPAS was applied in the analysis of auxiliary lanes in a multitude of scenarios, around 98,000, where traffic volumes, longitudinal gradients, initiation and length of the auxiliary lane and percentage of trucks were varied; the influence of random variation of traffic generated wealth of information for the scope of this paper and considered for further analysis. A computational tool, the PEMAT, which allows automatic execution of TWOPAS (TAM), capturing the results of each simulation and generating outputs in terms of operational indicators was created. Among the results of the analysis of auxiliary lanes are factors to consider the effect of passing and climbing lanes in the Percentage Time Spent Following (PTSF) and the Average Travel Speed (ATS) to adapt the procedure of Highway Capacity Manual (HCM) in 2010 and to estimate the level of service on two-lane road sections with individual auxiliary lanes. The manuals for the calculation of the capacity and level of service on conventional roads does not cover the diversity of geometric and traffic conditions so that a procedure for analyzing the transit operation in any conventional road was proposed to facilitate overtaking by consideration of a number of auxiliary lanes in both directions of traffic simulation model with TWOPAS; thus overtaking can be solved for any configuration of road and transit improvements in methods in manuals or technical guidance. / [ES] La calidad de la circulación en carreteras convencionales está estrechamente vinculada con la posibilidad de realizar la maniobra de adelantamiento que es especialmente crítica además por el nivel de riesgo que supone realizarla. Las opciones para facilitar el adelantamiento son proveer en el trazado las condiciones geométricas para que el adelantamiento se pueda realizar a lo largo de la vía con suficientes oportunidades pero cuando esta se dificulta se dispone de la alternativa de proveer una sección transversal que facilite este adelantamiento mediante los carriles auxiliares. En este trabajo de investigación se abordó esta segunda opción con los carriles de adelantamiento y de ascenso. Para caracterizar la maniobra de adelantamiento en pendientes ascendentes se hizo un estudio experimental que permitió disponer de datos y extraer información importante para la calibración de un modelo de simulación microscópica del tránsito en carreteras convencionales denominado TWOPAS, el cual es elemento principal del Traffic Analysis Module (TAM) que integra el Interactive Highway Safety Design Model (IHSDM). TWOPAS fue validado en otra carretera convencional de características bien diferentes a la considerada en la calibración que completó la evaluación de la utilidad de este modelo de simulación. Orientado hacia el objetivo de este trabajo de investigación se aplicó el TWOPAS en el análisis de carriles auxiliares en una multiplicidad de escenarios, alrededor de 98.000, en los cuales se variaron los volúmenes de tránsito, pendientes longitudinales, inicio y longitud del carril auxiliar, porcentaje de camiones y considerando la influencia de la variación aleatoria del tránsito que generó gran cantidad de información para el alcance de este trabajo y para nuevos análisis. Se creó una herramienta computacional, el PEMAT, que permite la ejecución automática del TWOPAS (TAM), la captura de los resultados de cada simulación y la generación de las salidas en términos de indicadores operacionales. Entre los resultados obtenidos del análisis de carriles auxiliares están factores para considerar el efecto de carriles de adelantamiento y ascenso en el Porcentaje de Tiempo Consumido en el Seguimiento (PTSF) y la Velocidad Media de Recorrido (ATS) para adaptar el procedimiento del Highway Capacity Manual (HCM) de 2010 para estimar el nivel de servicio en tramos de carretera convencional con carriles auxiliares individuales. Los manuales para el cálculo de la capacidad y el nivel de servicio en carreteras convencionales no cubre la diversidad de condiciones geométricas y de tránsito por lo que se propuso un procedimiento para adelantar el análisis de la operación del tránsito en cualquier carretera convencional para facilitar el adelantamiento mediante la consideración de una serie de carriles auxiliares en los dos sentidos de circulación de dicha vía sustentado en la aplicación de la simulación con el modelo TWOPAS de manera que puede atenderse la necesidad de demanda de adelantamiento para cualquier configuración de carretera y condición de tránsito mejorando los métodos contemplados en los manuales o guía técnicas. / [CAT] La qualitat de la circulació en carreteres convencionals està estretament vinculada amb la possibilitat de realitzar la maniobra d'avançament que és especialment crítica a més per el nivell de risc que suposa el realitzar-la. Les opcions per facilitat l'avançament son proveir en el traçat les condicions geomètriques per a que l'avançament es puga realitzar al llarg de la via amb suficients oportunitats però quan aquesta es dificulta es disposa de l'alternativa de proveir una secció transversal per facilitar aquest avançament mitjançant els carrils auxiliars. En aquest treball d'investigació es va abordar aquesta segona opció amb els carrils d'avançament i d'ascens. Per caracteritzar la maniobra d'avançament en pendent ascendent es va fer un estudi experimental que va possibilitar disposar de dades i extraure informació important per a la calibració d'un model de simulació microscòpica del trànsit en carreteres convencionals denominat TWOPAS, el qual es element principal del Traffic Analysis Module (TAM) que integra l'Interactive Highway Safety Design Model (IHSDM). TWOPAS va ser validat en un altra carretera convencional de característiques ben diferents a la considerada en la calibració que va completar la avaluació de la utilitat de aquest model de simulació. Orientat a l'objectiu d'aquest treball d'investigació es va aplicar el TWOPAS en l'anàlisi de carrils auxiliars en una multiplicitat d'escenaris, voltant els 98.000, en els quals es variaren els volums de trànsit, pendents longitudinals, inici i longitud del carril auxiliar, percentatge de camions i tenint en compte la influència de la variació aleatòria del trànsit que va generar gran quantitat d'informació per al alcans d'aquest treball i per a nous anàlisis. Es va crear una ferramenta computacional, el PEMAT, que permet la execució automàtica del TWOPAS (TAM), la captura dels resultats de cada simulació i la generació de les eixides en terminis d'indicadors operacionals. Entre els resultats obtinguts de l'anàlisi de carrils auxiliars estan factors per considerar l'efecte de carrils d'avançament i ascens en el Percentatge de Temps Consumit en el Seguiment (PTSF) i la Velocitat Mitjana de Recorregut (ATS) per a adaptar el procediment del Highway Capacity Manual (HCM) de 2010 per a estimar el nivell de servici en trams de carretera convencional amb carrils auxiliars individuals. Els manuals per al càlcul de la capacitat i el nivell de servici en carreteres convencionals no cobreixen la diversitat de condicions geomètriques i de trànsit per el que es va proposar un procediment per avançar l'anàlisi de la operació del trànsit en qualsevol carretera convencional per a facilitat l'avançament mitjançant la consideració d'una sèrie de carrils auxiliars en els dos sentits de circulació d'eixa via sustentat en l'aplicació de la simulació amb el model TWOPAS de manera que es puga atendre la necessitat de demanda d'avançaments per a qualsevol configuració de carretera i condició de trànsit millorant els mètodes contemplats en els manuals o guies tècniques. / Valencia Alaix, VG. (2016). ELABORACIÓN DE PROCEDIMIENTOS PARA FACILITAR EL ADELANTAMIENTO EN CARRETERAS CONVENCIONALES APLICANDO SIMULACIÓN [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62413 / TESIS

The purpose of this paper is to supply a summary of library subroutines and functions for parallel MIMD computers. The subroutines have been developed and continously extended at the University of Chemnitz since the end of the eighties. In detail, they are concerned with vector operations, inter-processor communication and simple graphic output to workstations. One of the most valuable features is the machine-independence of the communication subroutines proposed in this paper for a hypercube topology of the parallel processors (excepting a kernel of only two primitive system-dependend operations). They were implemented and tested for different hardware and operating systems including PARIX for transputers and PowerPC, nCube, PVM, MPI. The vector subroutines are optimized by the use of C language and unrolled loops (BLAS1-like). Hardware-optimized BLAS1 routines may be integrated. The paper includes hints for programmers how to use the libraries with both Fortran and C programs.

The purpose of this paper is to supply a summary of library subroutines and functions for parallel MIMD computers. The subroutines have been developed at the University of Chemnitz during a period of the last five years. In detail, they are concerned with vector operations, inter-processor communication and simple graphic output to workstations. One of the most valuable features is the machine-independence of the communication subroutines proposed in this paper for a hypercube topology of the parallel processors (excepting a kernel of only two primitive system-dependend operations). They were implemented and tested for different hardware and operating systems including transputer, nCube, KSR, PVM. The vector subroutines are optimized by the use of C language and enrolled loops (BLAS1-like). The paper includes hints for using the libraries with both Fortran and C programs.