Improvements in Hardware Transactional Memory for GPU Architectures

In the multi-core CPU world, transactional memory (TM)has emerged as an alternative to lock-based programming for thread synchronization. Recent research proposes the use of TM in GPU architectures, where a high number of computing threads, organized in SIMT fashion, requires an effective synchronization method. In contrast to CPUs, GPUs offer two memory spaces: global memory and local memory. The local memory space serves as a shared scratch-pad for a subset of the computing threads, and it is used by programmers to speed-up their applications thanks to its low latency. Prior work from the authors proposed a lightweight hardware TM (HTM) support based in the local memory, modifying the SIMT execution model and adding a conflict detection mechanism. An efficient implementation of these features is key in order to provide an effective synchronization mechanism at the local memory level. After a quick description of the main features of our HTM design for GPU local memory, in this work we gather together a number of proposals designed with the aim of improving those mechanisms with high impact on performance. Firstly, the SIMT execution model is modified to increase the parallelism of the application when transactions must be serialized in order to make forward progress. Secondly, the conflict detection mechanism is optimized depending on application characteristics, such us the read/write sets, the probability of conflict between transactions and the existence of read-only transactions. As these features can be present in hardware simultaneously, it is a task of the compiler and runtime to determine which ones are more important for a given application. This work includes a discussion on the analysis to be done in order to choose the best configuration solution.

Ocular scanning and perceptual size distortion in hemispatial neglect: effects of prism adaptation and sequential stimulus presentation

When asked to compare two lateralized shapes for horizontal size, neglect patients often indicate the left stimulus to be smaller. Gainotti and Tiacci (1971) hypothesized that this phenomenon might be related to a rightward bias in the patients' gaze. This study aimed to assess the relation between this size underestimation and oculomotor asymmetries. Eye movements were recorded while three neglect patients judged the horizontal extent of two rectangles. Two experimental manipulations were performed to increase the likelihood of symmetrical scanning of the stimulus display. The first manipulation entailed a sequential, rather than simultaneous presentation of the two rectangles. The second required adaptation to rightward displacing prisms, which is known to reduce many manifestations of neglect. All patients consistently underestimated the left rectangle, but the pattern of verbal responses and eye movements suggested different underlying causes. These include a distortion of space perception without ocular asymmetry, a failure to view the full leftward extent of the left stimulus, and a high-level response bias. Sequential presentation of the rectangles and prism adaptation reduced ocular asymmetries without affecting size underestimation. Overall, the results suggest that leftward size underestimation in neglect can arise for a number of different reasons. Incomplete leftward scanning may perhaps be sufficient to induce perceptual size distortion, but it is not a necessary prerequisite.

Traduction statistique par recherche locale

La traduction statistique vise l’automatisation de la traduction par le biais de modèles statistiques. Dans ce travail, nous relevons un des grands défis du domaine : la recherche (Brown et al., 1993). Les systèmes de traduction statistique de référence, tel Moses (Koehn et al., 2007), effectuent généralement la recherche en explorant l’espace des préfixes par programmation dynamique, une solution coûteuse sur le plan computationnel pour ce problème potentiellement NP-complet (Knight, 1999). Nous postulons qu’une approche par recherche locale (Langlais et al., 2007) peut mener à des solutions tout aussi intéressantes en un temps et un espace mémoire beaucoup moins importants (Russell et Norvig, 2010). De plus, ce type de recherche facilite l’incorporation de modèles globaux qui nécessitent des traductions complètes et permet d’effectuer des modifications sur ces dernières de manière non-continue, deux tâches ardues lors de l’exploration de l’espace des préfixes. Nos expériences nous révèlent que la recherche locale en traduction statistique est une approche viable, s’inscrivant dans l’état de l’art.

História, memória e espaços: experiências dos ex-combatentes de Parelhas-RN na defesa do litoral brasileiro durante a Segunda Guerra Mundial

The present essay has how I aim to analyse the memories of the ex-combatants of Parelhas-RN, specially of the components of the Força de Vigilância e Segurança do Litoral - FVSL, protagonists of the Brazilian participation in the scenery of the Second World war. Along this we looked to understand in which surrounding geographicalpartner these men were living before the War and what were the consequences of a brusque change of space owing to the convocation for the Armed Brazilian Strength in that historical context. The defense of the Brazilian coast during the War was not a so simple task, I have in mind the precariedade logistics of the Armed Strength, the attacks of submarines of the Axle that killed hundreds of civilians and Brazilian soldiers and the net of espionage mounted by Germany in Brazil. Leaving from the notion of collective memory and estrangement in Maurice Halbwachs, we will use the oral history like principal methodology, with the end of rescue these underground memories what also will make possible us the vision realizes that the protagonists themselves have of the event, besides the use of documents, photos, maps and any sort of fountains that make possible us to rebuild the scenery of Parelhas in the beginning of the War and the trajectory of life of his veterans

Cidade Velha e Feliz Lusitânia: cenários do Patrimônio Cultural em Belém

A Tese foi motivada pela redescoberta do bairro da Cidade Velha, na cidade de Belém, estado do Pará, redescoberta da autora em sua infância e do bairro em si enquanto espaço da memória e marco para o risorgimento do Pará. Analisa os conceitos de Patrimônio na cidade moderna, bem como a construção de um imaginário mítico que povoa a memória dos cidadãos belemenses em três etapas: da Colonização Pombalina; da Belle Èpoque e do Novo Pará. A argumentação é construída a partir de narrativas de diversos atores que interagem com o bairro: moradores antigos, moradores novos, comerciantes, técnicos do patrimônio, bem como pela leitura de imagens que ajudam a contar a história do bairro e de como ele é visto enquanto patrimônio. O método etnográfico juntamente com a semiótica foram os guias para a leitura dos materiais escritos, orais e visuais, ajudando no posicionamento da pesquisadora nos papéis de antiga moradora, arquiteta e artista plástica. Traçando um panorama sobre os conceitos de Cultura presentes na Cidade Velha, desde a visão dos residentes até a dos planejadores do projeto Feliz Lusitânia, este trabalho monta um mosaico onde aparecem as arestas entre as concepções de patrimônio dos técnicos e dos segmentos sociais.

Estudo exploratório comparativo do declínio cognitivo senil após estimulação multissensorial e cognitiva em idosos institucionalizados e não institucionalizados

O objetivo do presente trabalho foi investigar, empregando testes neuropsicológicos selecionados, a duração dos efeitos benéficos do programa de estimulação multissensorial e cognitiva realizado em idosos vivendo em instituições de longa permanência ou em comunidade. Os participantes do estudo foram idosos institucionalizados (n=20, 75,1 ± 6,8 anos de idade) e não institucionalizados (n=15, 74,1 ± 3,9 anos de idade), com 65 anos de idade ou mais, sem histórico de traumatismo crânio-encefálico, acidente vascular encefálico ou depressão primária, acuidade visual mínima 20/30 mensurada pelo Teste de Snellen e que participaram regularmente do Programa de Estimulação Multissensorial e Cognitiva. Foram realizadas reavaliações em cinco períodos (2, 4, 6, 8 e 12 meses) após a finalização da intervenção multissensorial e cognitiva. Para isso empregou-se o Mini Exame do Estado Mental (MEEM); nomeação de Boston; fluência verbal semântica (FVS) e fonológica (FVF), testes da Bateria Montreal de Avaliação da Comunicação (MAC), Teste de Narrativa “Roubo de Biscoitos” e testes neuropsicológicos selecionados da Bateria Cambridge (CANTAB) incluindo: Triagem Motora (Motor Screening – MOT); Processamento Rápido de Informação Visual (Rapid Visual Information Processing – RVP); Tempo de Reação (Reaction Time - RTI); Aprendizagem Pareada (Paired Associates Learning - PAL); Memória de Trabalho Espacial (Spatial Working Memory - SWM) e Pareamento com Atraso (Delayed matching to sample - DMS). Os resultados apontaram diferenças estatisticamente significativas entre os grupos revelando taxa de declínio cognitivo maior nos idosos institucionalizados. Esses resultados confirmam sugestão anterior de que o ambiente pobre de estímulos somato-motores e cognitivos das instituições de longa permanência aceleram o declínio cognitivo senil. Além disso, a análise das curvas ROC seguido dos cálculos de sensibilidade, especificidade e eficiência para cada teste revelou que os testes da bateria CANTAB para memória e aprendizado espacial pareado assim como para memória espacial de trabalho permitiram a distinção entre os grupos I e NI em todas janelas de reavaliação. Os resultados demonstraram que uma vez cessado o programa de estimulação, se observa em ambos os grupos declínio cognitivo progressivo, com perdas mais precoces e mais intensas nos idosos institucionalizados do que naqueles vivendo em comunidade com suas famílias. Além disso, observou-se que a duração dos efeitos benéficos sobre o desempenho nos testes neuropsicológicos de ambos os grupos é heterogêneo, e que os efeitos de proteção guardam relação estreita com a natureza das oficinas. Por conta disso os escores dos testes de linguagem declinaram mais lentamente. Os resultados reúnem evidências que permitem a recomendação de programas regulares de estimulação somatomotora e cognitiva para idosos institucionalizados com o intuito de promover a redução da taxa de progressão do declínio cognitivo senil.

Memória e Memórias: entre o eu da ficção e a ficcionalização do eu

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

João Miramar e as dobras do texto

This study about Memórias Sentimentais de João Miramar, by Oswald de Andrade, aims to explore the voices that organize the space of language in the narrative. Such space has an operative vision called polyphony, by which the signs organize themselves out of a hierarchical scale, although the chronological axis of the life of João Miramar is the guiding principle of the episodes.

Memória e identidade em Jaguariaíva, Paraná: contribuição à cartografia escolar

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Memória e identidade em Jaguariaíva, Paraná: contribuição à cartografia escolar

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Gauss-Seidel Estimation of Generalized Linear Mixed Models with Application to Poisson Modeling of Spatially Varying Disease Rates

Generalized linear mixed models (GLMMs) provide an elegant framework for the analysis of correlated data. Due to the non-closed form of the likelihood, GLMMs are often fit by computational procedures like penalized quasi-likelihood (PQL). Special cases of these models are generalized linear models (GLMs), which are often fit using algorithms like iterative weighted least squares (IWLS). High computational costs and memory space constraints often make it difficult to apply these iterative procedures to data sets with very large number of cases. This paper proposes a computationally efficient strategy based on the Gauss-Seidel algorithm that iteratively fits sub-models of the GLMM to subsetted versions of the data. Additional gains in efficiency are achieved for Poisson models, commonly used in disease mapping problems, because of their special collapsibility property which allows data reduction through summaries. Convergence of the proposed iterative procedure is guaranteed for canonical link functions. The strategy is applied to investigate the relationship between ischemic heart disease, socioeconomic status and age/gender category in New South Wales, Australia, based on outcome data consisting of approximately 33 million records. A simulation study demonstrates the algorithm's reliability in analyzing a data set with 12 million records for a (non-collapsible) logistic regression model.

Hippocampus is place of interaction between unconscious and conscious memories retrieval

Recent experiments suggest that humans can form and later retrieve new semantic relations unconsciously by way of hippocampus - the key structure thought to support conscious relational (episodic) memory. Given that the hippocampus subserves both conscious and unconscious relational encoding/retrieval, we expected the hippocampus to be place of unconscious-conscious interactions. This hypothesis was tested in an fMRI experiment on the interaction between the unconscious retrieval of face-associated occupations and the subsequent conscious retrieval of celebrities’ occupations. For subliminal encoding, masked combinations of an unfamiliar face and a written occupation (“actor” or “politician”) were subliminally presented. At test, we presented the former subliminal faces again, without occupations and masks, as conscious retrieval cues. We hypothesized that faces would trigger the unconscious reactivation of the associated occupation - actor or politician -, which in turn would facilitate or inhibit the subsequent conscious recollection of a celebrity’s occupation. Following the presentation of a former subliminal face, we presented the portrait of a celebrity that participants were required to sort according to “actor” or “politician”. Depending on whether the triggered unconscious occupation was congruent or incongruent with the celebrity’s occupation, we expected an expedited or retarded conscious retrieval process as reflected in reaction times. Conscious retrieval was expedited in the congruent condition, but there was no effect in the incongruent condition. fMRI data collected during subliminal relational encoding confirmed that the hippocampus was interacting with neocortical semantic storage sites. fMRI data collected at test indicated that the facilitated conscious retrieval of celebrity-associated occupations was related to deactivations in this same network spanning hippocampus and neocortical semantic storage sites. Hence, unconscious retrieval likely preactivated this network, which allowed for a sparing recruitment of additional neural resources to assist conscious retrieval. This finding supports the notion that consciously and unconsciously acquired relational memories are stored in a single, cohesive hippocampal-neocortical memory space.

Hippocampus Is Place of Interaction between Unconscious and Conscious Memories.

Recent evidence suggests that humans can form and later retrieve new semantic relations unconsciously by way of hippocampus-the key structure also recruited for conscious relational (episodic) memory. If the hippocampus subserves both conscious and unconscious relational encoding/retrieval, one would expect the hippocampus to be place of unconscious-conscious interactions during memory retrieval. We tested this hypothesis in an fMRI experiment probing the interaction between the unconscious and conscious retrieval of face-associated information. For the establishment of unconscious relational memories, we presented subliminal (masked) combinations of unfamiliar faces and written occupations ("actor" or "politician"). At test, we presented the former subliminal faces, but now supraliminally, as cues for the reactivation of the unconsciously associated occupations. We hypothesized that unconscious reactivation of the associated occupation-actor or politician-would facilitate or inhibit the subsequent conscious retrieval of a celebrity's occupation, which was also actor or politician. Depending on whether the reactivated unconscious occupation was congruent or incongruent to the celebrity's occupation, we expected either quicker or delayed conscious retrieval process. Conscious retrieval was quicker in the congruent relative to a neutral baseline condition but not delayed in the incongruent condition. fMRI data collected during subliminal face-occupation encoding confirmed previous evidence that the hippocampus was interacting with neocortical storage sites of semantic knowledge to support relational encoding. fMRI data collected at test revealed that the facilitated conscious retrieval was paralleled by deactivations in the hippocampus and neocortical storage sites of semantic knowledge. We assume that the unconscious reactivation has pre-activated overlapping relational representations in the hippocampus reducing the neural effort for conscious retrieval. This finding supports the notion of synergistic interactions between conscious and unconscious relational memories in a common, cohesive hippocampal-neocortical memory space.

Reflexionar sobre los lugares de memoria : Los emplazamientos de memoria como marcas territoriales

El presente artículo se propone contribuir al estudio de la dimensión espacial de las prácticas de resignificación de los lugares que funcionaroncomo Centros Clandestinos de Detención en la última dictadura militar en la Argentina, haciendo foco en el Proyecto Mansión Seré, sitio en el que funcionó el ex Centro Clandestino Atila, entre los años 1977 y 1978, a cargo de la Fuerza Aérea. El lugar de memoria es delimitado y marcado, se hace visible a la mirada; en los hechos se definen procesos de lugarización que articulan las categorías de espacio urbano y memoria colectiva con un fin determinado (rememorar/conmemorar/denunciar), el cual establece los vínculos nuevamente significados por los que atraviesan y son atravesados los sujetos en ese espacio construido, en ese lugar de memoria.

Reflexionar sobre los lugares de memoria : Los emplazamientos de memoria como marcas territoriales

El presente artículo se propone contribuir al estudio de la dimensión espacial de las prácticas de resignificación de los lugares que funcionaroncomo Centros Clandestinos de Detención en la última dictadura militar en la Argentina, haciendo foco en el Proyecto Mansión Seré, sitio en el que funcionó el ex Centro Clandestino Atila, entre los años 1977 y 1978, a cargo de la Fuerza Aérea. El lugar de memoria es delimitado y marcado, se hace visible a la mirada; en los hechos se definen procesos de lugarización que articulan las categorías de espacio urbano y memoria colectiva con un fin determinado (rememorar/conmemorar/denunciar), el cual establece los vínculos nuevamente significados por los que atraviesan y son atravesados los sujetos en ese espacio construido, en ese lugar de memoria.