Wireless communication has seen a tremendous growth in the last decades. Continuing on this trend, wireless multi-hop networks  are nowadays used or planned for use in a multitude of contexts, spanning from Internet access at home to emergency situations. The Transmission Control Protocol (TCP) provides reliable and ordered delivery of a data and is used by major Internet applications such as web browsers, email clients and file transfer programs. TCP traffic is also the dominating traffic type on the Internet. However, TCP performs less than optimal in wireless multi-hop networks due to packet reordering, low link capacity, packet loss and variable delay. In this thesis, we develop novel proposals for enhancing the network and transport layer to improve TCP performance in wireless multi-hop networks. As initial studies, we experimentally evaluate the performance of different TCP variants, with and without mobile nodes. We further evaluate the impact of multi-path routing on TCP performance and propose packet aggregation combined with aggregation aware multi-path forwarding as a means to better utilize the available bandwidth. The last contribution is a novel extension to multi-path TCP to  enable single-homed hosts to fully utilize the network capacity. / <p>Opponent changed. Prof. C. Lindeman from the University of Leipzig was substituted by Prof. Zhang.</p>

In recent years there has been an exponential growth in Internet traffic resulting in increased network bandwidth requirements which, in turn, has led to stringent processing requirements on network layer devices like routers. Present backbone routers on OC 48 links (2.5Gbps) have to process four million minimum-sized packets per second. Further, the functionality supported in the network devices is also on the increase leading to programmable processors, such as Intel's IXP, Motorola's C5 and IBM's.NP. These processors support multiple processors and multiple threads to exploit packet-level-parallelism inherent in network workloads. This thesis studies the performance of network processors. We develop a Petri Net model for a commercial network processors (Intel IXP 2400,2850) for three different applications viz., IPv4 forwarding, Network Address Translation and IP security protocols. A salient feature of the Petri net model is its ability to model the application, architecture and their interaction in great detail. The model is validated using the intel proprietary tool (SDK 3.51 for IXP architecture) over a range of configurations. Our Performance evaluation results indicate that 1. The IXP processor is able to support a throughput of 2.5 Gbps for all modeled applications. 2. Packet buffer memory (DRAM) is the bottleneck resource in a network proces sor and even multithreading is ineffective beyond a total of 16 threads in case of header processing applications and beyond 32 threads for payload processing applications. Since DRAM is the bottleneck resource we explore the benefits of increasing the DRAM banks and other software schemes like offloading the packet header to SRAM. The second part of the thesis studies the impact of parallel processing in network processor on packet reordering and retransmission. Our results indicate that the concurrent processing of packets in a network processor and buffer allocation schemes in TFIFO leads to a significant packet reordering, (61%), on a 10-hop network (with packet sizes of 64 B) which in turn leads to a 76% retransmission under the TCP fast-restransmission algorithm. We explore different transmit buffer allocation schemes namely, contiguous, strided, local, and global for transmit buffer which reduces the packet retransmission to 24%. Our performance results also indicate that limiting the number of microengines can reduce the extent of packet reordering while providing the same throughput. We propose an alternative scheme, Packetsort, which guarantees complete packet ordering while achieving a throughput of 2.5 Gbps. Further, we observe that Packetsort outperforms, by up to 35%, the in-built schemes in the IXP processor namely, Inter Thread Signaling (ITS) and Asynchronous Insert and Synchronous Remove (AISR). The final part of this thesis investigates the performance of the network processor in a bursty traffic scenario. We model bursty traffic using a Pareto distribution. We consider a parallel and pipelined buffering schemes and their impact on packet drop under bursty traffic. Our results indicate that the pipelined buffering scheme outperforms the parallel scheme.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-05-11T12:37:34Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO DEFINITIVA..pdf: 1060899 bytes, checksum: f4e37d8ac8c033db6ea98cbb2e3cd92b (MD5) / Made available in DSpace on 2016-05-11T12:37:34Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO DEFINITIVA..pdf: 1060899 bytes, checksum: f4e37d8ac8c033db6ea98cbb2e3cd92b (MD5) Previous issue date: 2015-09-15 / CAPEs / Este trabalho objetivou compreender de que forma ocorre o processo de conversão entre as mulheres ao neopentecostalismo em Lajedo, cidade localizada no agreste meridional pernambucano a 192 km da capital Recife, tendo como principal mediador nesse processo de conversão os seus próprios maridos. Como forma de compreender a lógica sociocultural de tais conversões e ao próprio sentimento de pertencimento a comunidade religiosa ao qual se filiam, a conversão dessas mulheres, tendo seus esposos enquanto mediador, mostra-se fecundo para estabelecer uma nova análise da lógica da conversão ao cristianismo: o homem mediando a conversão da mulher. Analisarei a conversão desses homens a essas igrejas, e posteriormente mostrarei como eles se tornam mediadores na conversão de suas mulheres, se apresentando para elas como homens renovados após suas conversões. Farei também uma análise dos ritos batismais observados nessas igrejas, ritos direcionados para confirmação da conversão dos novos fiéis. Para realização deste estudo etnográfico utilizou-se metodologicamente a pesquisa qualitativa na medida em que se busca compreender o contexto social e cultural desses casais inseridos na comunidade religiosa. Como recorte etnográfico foi realizado pesquisa de campo na Igreja Universal do Reino de Deus (IURD) e na Igreja Mundial do Poder de Deus (IMPD), além da observação de ritos batismais na Igreja Apostólica Fonte da Vida, igrejas as quais os casais que participaram da pesquisa são filiados. / This study aimed to understand how the conversion process occurs among women in the neo-Pentecostalism Lajedo, a town in the southern wild Pernambuco 192 km away from the capital Recife, the main mediator in this conversion process are their own husbands. In order to understand the socio-cultural logic of such conversions and their own sense of belonging to a religious community which they are affiliated, the conversion of these women, with their husbands as a mediator, it is shown fruitful to establish a new analysis of the conversion logic to Christianity: man mediating the conversion their women. I analyze the conversion of these men to those churches, and then I will show how they become mediators in converting their wives, introducing themselves as men renewed after their conversions. I will do an analysis of the baptismal rites observed in those churches, directed rites to confirm the conversion of new believers. Carrying out this ethnographic study was used methodologically qualitative research on that seeking to understand the social and cultural context of those couples entered the religious community. As ethnographic highlight was carried out a field researching on the Universal Church of the Kingdom of God (UCKG) and the World Church of God's Power (IMPD), and the observation baptismal rites in the Apostolic Fountain of Life Church, churches which couples who participated on the researching are affiliated.

Made available in DSpace on 2016-12-23T14:33:47Z (GMT). No. of bitstreams: 1 Kamila Ribeiro Ghidetti parte 1 p 1-60.pdf: 1277319 bytes, checksum: 04f11c251510276dd05a0c29559e9cb9 (MD5) Previous issue date: 2011-07-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A análise da influência dos algoritmos de reordenamento de matrizes na resolução de sistemas lineares utilizando os m´métodos iterativos não estacionários GMRES e Gradiente Conjugado, ambos com e sem precondicionamento, é o objeto de estudo desse trabalho. Os algoritmos mais referenciados na literatura para reordenamento de matrizes são Reverse Cuthill-McKee (RCM), Gibbs-Poole-Stockmeyer (GPS), Nested Dissection (ND) e Espectral (ES). Neste trabalho esses algoritmos foram analisados e algumas modificações foram propostas. Todos os algoritmos e suas versões modificadas foram implementados e comparados quanto a qualidade de solução (minimização de largura de banda e minimização de envelope) e tempo de execução. Além disso, os sistemas lineares associados as matrizes esparsas são resolvidos via m´métodos iterativos tipo Krylov precondicionados. Os precondicionadores analisados nesse estudo são baseados na fatoração LU incompleta. Para os testes computacionais é considerado um conjunto de matrizes estruturalmente simétricas oriundas das mais diversas áreas do conhecimento. Nossos estudos concluem que o reordenamento das matrizes, na maioria dos casos, reduz o numero de iterações dos métodos iterativos, entretanto a redução do tempo de processamento é dependente da dimensão e do condicionamento da matriz / This work analyzes the influence of matrices reordering algorithms on solving linear systems using non-stationary iterative methods GMRES and Conjugate Gradient, both with and without preconditioning. The algorithms referenced most often in the literature for the reordering of matrices are Reverse Cuthill-McKee (RCM), Gibbs-Poole-Stockmeyer (GPS), Nested Dissection (ND) and Spectral (ES). We analyze these algorithms and propose some modifications comparing their solution qualities (minimizing bandwidth and minimizing envelope) and CPU times. Moreover, the linear systems associated with sparse matrices are solved via preconditioned Krylov-type iterative methods considering the incomplete LU factorization preconditioners. For the computational tests, we consider a set of structurally symmetric matrices that can come from various fields of knowledge. We conclude that the reordering of matrices, in most cases, reduces the number of iterations in the iterative methods, but the reducing of the CPU time depends on the size and conditioning of the matrix

No description available.

[pt] Esta pesquisa consiste no estudo do processo de reordenamento vivido no cotidiano de um Centro Espírita localizado em território urbano. O reordenamento, como um paradigma consignado pelo Sistema Único de Assistência Social/SUAS, estabelece um padrão de qualificação dos serviços socioassistenciais. Isto significa para as instituições do universo filantrópico religioso o imperativo de transitar de uma prática tradicional sociorreligiosa para efetivação de um serviço socioassistencial, em conformidade com o marco regulatório do SUAS. O que implica, em um processo de mudança da cultura organizacional mediante ações pedagógicas, a partir do qual a caridade permanece, mas em seu significado original de princípio ético que fundamenta um padrão de sociabilidade reconhecedor do outro como sujeito de direitos. A base teórica do estudo contou com três conceitos, considerados fundamentais, por se constituírem em pedras angulares de três modelos de proteção social que marcaram a trajetória da assistência social no Brasil: CARIDADE, FILANTROPIA e JUSTIÇA. Destacou a construção da proteção sociorreligiosa espírita no Brasil, consoante as experiências humanas de proteção primária e secundária que atravessaram culturas e práticas sociais ao longo do tempo. Reconheceu a implementação de um modelo de proteção social não contributiva no Brasil como uma conquista civilizatória que afirma direitos para segmentos populacionais em situação de desproteções que configuram expressões da questão social. Para tanto, utilizou um tipo de investigação denominada de Observação Participante. No caso, aplicada em uma experiência singular de reordenamento de uma instituição religiosa espírita - Rocinha /Rio de Janeiro - que tem, além da finalidade de estudar e divulgar o Espiritismo, a de ofertar serviços e benefícios socioaasistencias, participando da rede de proteção social básica territorial. / [en] This Research project aims to analyses the reordering process experienced on the daily life of a spiritualist religious institution located in urban territory. The reordering, as a paradigm used by the Unique System of Social Assistance - SUAS (Portuguese abbreviation), establishes a standard of management and qualification of these social services. This means for the institutions of the religious philanthropic universe the need to move from a traditional socio-religious practice for realization of social assistance services in accordance with the regulatory framework of SUAS. What implies an organizational culture change process, through educational activities, from which charity remains, but in its original meaning of ethical principle that bases a pattern of social skills, that recognizes the other as a citizen with rights. The theoretical basis of the study will have three concepts considered fundamental, as they represent the origin of the models of social protection that marked the trajectory of social assistance in Brazil: Charity, Philanthropy and Justice. The study will highlight the construction of spiritualist socio-religious protection in Brazil, according to the human experiences of primary and secondary protection that have crossed cultures and social practices over time. The implementation of a non-contributory social protection model in Brazil will be recognized as a civilizational achievement that affirms rights for population segments in situations of lack of protection that configure expressions of the social issue. To achieve that, a type of research called Participant Observation will be used, applied in a unique experience of reordering a spiritualist religious institution located in Rocinha - city of Rio de Janeiro - which has, in addition to the purpose of study and disseminate Spiritualism, the purpose to offer services and social assistance benefits participating in the basic social and territorial protection services network.

Les problèmes de satisfaction de contraintes distribués (DisCSP) permettent de formaliser divers problèmes qui se situent dans l'intelligence artificielle distribuée. Ces problèmes consistent à trouver une combinaison cohérente des actions de plusieurs agents. Durant cette thèse nous avons apporté plusieurs contributions dans le cadre des DisCSPs. Premièrement, nous avons proposé le Nogood-Based Asynchronous Forward-Checking (AFC-ng). Dans AFC-ng, les agents utilisent les nogoods pour justifier chaque suppression d'une valeur du domaine de chaque variable. Outre l'utilisation des nogoods, plusieurs backtracks simultanés venant de différents agents vers différentes destinations sont autorisés. En deuxième lieu, nous exploitons les caractéristiques intrinsèques du réseau de contraintes pour exécuter plusieurs processus de recherche AFC-ng d'une manière asynchrone à travers chaque branche du pseudo-arborescence obtenu à partir du graphe de contraintes dans l'algorithme Asynchronous Forward-Checking Tree (AFC-tree). Puis, nous proposons deux nouveaux algorithmes de recherche synchrones basés sur le même mécanisme que notre AFC-ng. Cependant, au lieu de maintenir le forward checking sur les agents non encore instanciés, nous proposons de maintenir la consistance d'arc. Ensuite, nous proposons Agile Asynchronous Backtracking (Agile-ABT), un algorithme de changement d'ordre asynchrone qui s'affranchit des restrictions habituelles des algorithmes de backtracking asynchrone. Puis, nous avons proposé une nouvelle méthode correcte pour comparer les ordres dans ABT_DO-Retro. Cette méthode détermine l'ordre le plus pertinent en comparant les indices des agents dès que les compteurs d'une position donnée dans le timestamp sont égaux. Finalement, nous présentons une nouvelle version entièrement restructurée de la plateforme DisChoco pour résoudre les problèmes de satisfaction et d'optimisation de contraintes distribués. / Distributed Constraint Satisfaction Problems (DisCSP) is a general framework for solving distributed problems. DisCSP have a wide range of applications in multi-agent coordination. In this thesis, we extend the state of the art in solving the DisCSPs by proposing several algorithms. Firstly, we propose the Nogood-Based Asynchronous Forward Checking (AFC-ng), an algorithm based on Asynchronous Forward Checking (AFC). However, instead of using the shortest inconsistent partial assignments, AFC-ng uses nogoods as justifications of value removals. Unlike AFC, AFC-ng allows concurrent backtracks to be performed at the same time coming from different agents having an empty domain to different destinations. Then, we propose the Asynchronous Forward-Checking Tree (AFC- tree). In AFC-tree, agents are prioritized according to a pseudo-tree arrangement of the constraint graph. Using this priority ordering, AFC-tree performs multiple AFC-ng processes on the paths from the root to the leaves of the pseudo-tree. Next, we propose to maintain arc consistency asynchronously on the future agents instead of only maintaining forward checking. Two new synchronous search algorithms that maintain arc consistency asynchronously (MACA) are presented. After that, we developed the Agile Asynchronous Backtracking (Agile-ABT), an asynchronous dynamic ordering algorithm that does not follow the standard restrictions in asynchronous backtracking algorithms. The order of agents appearing before the agent receiving a backtrack message can be changed with a great freedom while ensuring polynomial space complexity. Next, we present a corrigendum of the protocol designed for establishing the priority between orders in the asynchronous backtracking algorithm with dynamic ordering using retroactive heuristics (ABT_DO-Retro). Finally, the new version of the DisChoco open-source platform for solving distributed constraint reasoning problems is described. The new version is a complete redesign of the DisChoco platform. DisChoco 2.0 is an open source Java library which aims at implementing distributed constraint reasoning algorithms.

[pt] A dissertação trata da Instituição Romão de Mattos Duarte, enfocando as transformações, as adequações e os desafios em se reorganizar diante dos novos imperativos legislativos que se operaram na instituição após 1990, com o Estatuto da Criança e do Adolescente (ECA, L. n. 8.069/90), que inovam em relação ao Código de Menores de 1979, para analisar como a instituição se organiza hoje, pós 2009, seguindo o percurso metodológico com observação participante, entrevistas e pesquisa em documentos. O objetivo principal deste estudo é analisar o espaço de acolhimento da Instituição Romão Duarte, enfocando a nova organização da instituição para atender a essas legislações: no que diz respeito ao atendimento das crianças acolhidas; ao seu espaço físico; à estrutura da sua equipe profissional; à idade das crianças em acolhimento; ao número de crianças acolhidas; às causas que levaram ao acolhimento; e às formas de solucionar seus destinos através da reintegração na sua família de origem pós tratamento social e/ou psicológico dos familiares ou encaminhamento para adoção. De fato, essa reorganização da Instituição Romão Duarte não se deu imediatamente, mas foi um processo longo, contínuo e gradual, demorando de 12 a 19 anos para se consolidar totalmente, gerando grandes transformações na forma de organização da instituição. / [en] This dissertation talks about Romão de Mattos Duarte Institution, focusing the transformations, adaptations and challenges to reorganize against new laws had produced in institution after 1990, with the Child and Adolescent Statute (ECA, Law nº 8.069/90), that innovate regarding to the Code of Minors from 1979, for analyzing as the institution has organized nowadays, after 2009, following the methodological route with participant observation, interviews and documentary research. This main study objective is examine the Romão Duarte host institution, highlighting the new organization to follow those laws: as for attending children cared; its physical space; professional team structure; age of children cared; the number of children cared; the reasons caused host; and the ways to solve their destinies thru origin family reintegration after social and/or psychological familiar treatment or forwarding for adoption. In fact, that Romão Duarte Institution reorganization was not occurred immediately, it was a long process, continuous and progressive it delayed from 12 to 19 years to consolidate completely, generating profound transformations in organization way of the institution.

Power dissipated during scan testing is becoming increasingly important for today’s very complex sequential circuits. It is shown that the power dissipated during test mode operation is in general higher than the power dissipated during functional mode operation, the test mode average power may sometimes go upto 3x and the peak power may sometimes go upto 30x of normal mode operation. The power dissipated during the scan operation is primarily due to the switching activity that arises in scan cells during the shift and capture operation. The switching in scan cells propagates to the combinational block of the circuit during scan operation, which in turn creates many transition in the circuit and hence it causes higher dynamic power dissipation. The excessive average power dissipated during scan operation causes circuit damage due to higher temperature and the excessive peak power causes yield loss due to IR-drop and cross talk. The higher peak power also causes the thermal related issue if it last for sufficiently large number of cycles. Hence, to avoid all these issues it is very important to reduce the peak power during scan testing. Further, in case of multi-module SoC testing the reduction in peak power facilitates in reducing the test application time by scheduling many test sessions parallelly. In this dissertation we have addressed all the above stated issues. We have proposed three different techniques to deal with the excessive peak power dissipation problem during test. The first solution proposes an efficient graph theoretic methodology for test vector reordering to achieve minimum peak power supported by the given test vector set. Three graph theoretic problems are formulated and corresponding algorithms to solve the problems are proposed. The proposed methodology also minimizes average power for the given minimum peak power. Further, a lower bound on minimum achievable peak power for a given test set is defined. The results on several benchmarks show that the proposed methodology is able to reduce peak power significantly. To address the peak power problem during scan test-cycle (the cycle between launch and capture pulse) we have proposed a scan chain reordering technique. A new formulation for scan chain reordering as TSP (Traveling Sales Person) problem and a solution is proposed. The experimental results show that the proposed methodology is able to minimize considerable amount of peak power compared to the earlier proposals. The capture power (power dissipated during capture cycle) problem in testing multi chip module (MCM) is also addressed. We have proposed a methodology to schedule the test set to reduce capture power. The scheduling algorithm consist of reordering of test vector and insertion of idle cycle to prevent capture cycle coincidence of scheduled cores. The experimental results show the significant reduction in capture power without increase in test application time.

La plupart des méthodes de traitement automatique des langues (TAL) peuvent être formalisées comme des problèmes de prédiction, dans lesquels on cherche à choisir automatiquement l'hypothèse la plus plausible parmi un très grand nombre de candidats. Malgré de nombreux travaux qui ont permis de mieux prendre en compte la structure de l'ensemble des hypothèses, la taille de l'espace de recherche est généralement trop grande pour permettre son exploration exhaustive. Dans ce travail, nous nous intéressons à l'importance du design de l'espace de recherche et étudions l'utilisation de contraintes pour en réduire la taille et la complexité. Nous nous appuyons sur l'étude de trois problèmes linguistiques — l'analyse morpho-syntaxique, le transfert cross-lingue et le problème du réordonnancement en traduction — pour mettre en lumière les risques, les avantages et les enjeux du choix de l'espace de recherche dans les problèmes de TAL.Par exemple, lorsque l'on dispose d'informations a priori sur les sorties possibles d'un problème d'apprentissage structuré, il semble naturel de les inclure dans le processus de modélisation pour réduire l'espace de recherche et ainsi permettre une accélération des traitements lors de la phase d'apprentissage. Une étude de cas sur les modèles exponentiels pour l'analyse morpho-syntaxique montre paradoxalement que cela peut conduire à d'importantes dégradations des résultats, et cela même quand les contraintes associées sont pertinentes. Parallèlement, nous considérons l'utilisation de ce type de contraintes pour généraliser le problème de l'apprentissage supervisé au cas où l'on ne dispose que d'informations partielles et incomplètes lors de l'apprentissage, qui apparaît par exemple lors du transfert cross-lingue d'annotations. Nous étudions deux méthodes d'apprentissage faiblement supervisé, que nous formalisons dans le cadre de l'apprentissage ambigu, appliquées à l'analyse morpho-syntaxiques de langues peu dotées en ressources linguistiques.Enfin, nous nous intéressons au design de l'espace de recherche en traduction automatique. Les divergences dans l'ordre des mots lors du processus de traduction posent un problème combinatoire difficile. En effet, il n'est pas possible de considérer l'ensemble factoriel de tous les réordonnancements possibles, et des contraintes sur les permutations s'avèrent nécessaires. Nous comparons différents jeux de contraintes et explorons l'importance de l'espace de réordonnancement dans les performances globales d'un système de traduction. Si un meilleur design permet d'obtenir de meilleurs résultats, nous montrons cependant que la marge d'amélioration se situe principalement dans l'évaluation des réordonnancements plutôt que dans la qualité de l'espace de recherche. / Most natural language processing tasks are modeled as prediction problems where one aims at finding the best scoring hypothesis from a very large pool of possible outputs. Even if algorithms are designed to leverage some kind of structure, the output space is often too large to be searched exaustively. This work aims at understanding the importance of the search space and the possible use of constraints to reduce it in size and complexity. We report in this thesis three case studies which highlight the risk and benefits of manipulating the seach space in learning and inference.When information about the possible outputs of a sequence labeling task is available, it may seem appropriate to include this knowledge into the system, so as to facilitate and speed-up learning and inference. A case study on type constraints for CRFs however shows that using such constraints at training time is likely to drastically reduce performance, even when these constraints are both correct and useful at decoding.On the other side, we also consider possible relaxations of the supervision space, as in the case of learning with latent variables, or when only partial supervision is available, which we cast as ambiguous learning. Such weakly supervised methods, together with cross-lingual transfer and dictionary crawling techniques, allow us to develop natural language processing tools for under-resourced languages. Word order differences between languages pose several combinatorial challenges to machine translation and the constraints on word reorderings have a great impact on the set of potential translations that is explored during search. We study reordering constraints that allow to restrict the factorial space of permutations and explore the impact of the reordering search space design on machine translation performance. However, we show that even though it might be desirable to design better reordering spaces, model and search errors seem yet to be the most important issues.