942 resultados para high-level synthesis
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An optimal measurement selection strategy based on incoherence among rows (corresponding to measurements) of the sensitivity (or weight) matrix for the near infrared diffuse optical tomography is proposed. As incoherence among the measurements can be seen as providing maximum independent information into the estimation of optical properties, this provides high level of optimization required for knowing the independency of a particular measurement on its counterparts. The proposed method was compared with the recently established data-resolution matrix-based approach for optimal choice of independent measurements and shown, using simulated and experimental gelatin phantom data sets, to be superior as it does not require an optimal regularization parameter for providing the same information. (C) 2014 Society of Photo-Optical Instrumentation Engineers (SPIE)
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High-level ab initio calculations have been used to study the interactions between the CH3 group of CH3X (X = F, Cl, Br, CN) molecules and pi-electrons. These interactions are important because of the abundance of both the CH3 groups and pi-electrons in biological systems. Complexes between C2H4/C2H2 and CH3X molecules have been used as model systems. Various theoretical methods such as atoms in molecules theory, reduced density gradient analysis, and natural bond orbital analysis have been used to discern these interactions. These analyses show that the interaction of the p-electrons with the CH3X molecules leads to the formation of X-C...p carbon bonds. Similar complexes with other tetrel molecules, SiH3X and GeH3X, have also been considered.
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The mechanisms of densification and creep were examined during spark plasma sintering (SPS) of alumina doped with a low and high level of zirconia or yttria, over a temperature range of 1173-1573 K and stresses between 25 and 100 MPa. Large additions of yttria led clearly to in situ reactions during SPS and the formation of a yttrium-aluminum garnet phase. Dopants generally lead to a reduction in the densification rate, with substantial reductions noted in samples with similar to 5.5 vol% second phase. In contrast to a stress exponent of n similar to 1 for pure alumina, the doped aluminas displayed n similar to 2 corresponding to an interface-controlled diffusion process. The higher activation energies in the composites are consistent with previous data on creep and changes in the interfacial energies. The results reveal a compensation effect, such that an increase in the activation energy is accompanied by a corresponding increase in the pre-exponential term for diffusion.
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While the tetrahedral face of methane has an electron rich centre and can act as a hydrogen bond acceptor, substitution of one of its hydrogens with some electron withdrawing group (such as -F/OH) can make the opposite face electron deficient. Electrostatic potential calculations confirm this and high level quantum calculations show interactions between the positive face of methanol/methyl fluoride and electron rich centers of other molecules such as H2O. Analysis of the wave functions of atoms in molecules shows the presence of an unusual C···Y interaction, which could be called 'carbon bonding'. NBO analysis and vibrational frequency shifts confirm the presence of this interaction. Given the properties of alkyl groups bonded to electronegative elements in biological molecules, such interactions could play a significant role, which is yet to be recognized. This and similar interactions could give an enthalpic contribution to what is called the 'hydrophobic interactions'.
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This paper presents the design and implementation of PolyMage, a domain-specific language and compiler for image processing pipelines. An image processing pipeline can be viewed as a graph of interconnected stages which process images successively. Each stage typically performs one of point-wise, stencil, reduction or data-dependent operations on image pixels. Individual stages in a pipeline typically exhibit abundant data parallelism that can be exploited with relative ease. However, the stages also require high memory bandwidth preventing effective utilization of parallelism available on modern architectures. For applications that demand high performance, the traditional options are to use optimized libraries like OpenCV or to optimize manually. While using libraries precludes optimization across library routines, manual optimization accounting for both parallelism and locality is very tedious. The focus of our system, PolyMage, is on automatically generating high-performance implementations of image processing pipelines expressed in a high-level declarative language. Our optimization approach primarily relies on the transformation and code generation capabilities of the polyhedral compiler framework. To the best of our knowledge, this is the first model-driven compiler for image processing pipelines that performs complex fusion, tiling, and storage optimization automatically. Experimental results on a modern multicore system show that the performance achieved by our automatic approach is up to 1.81x better than that achieved through manual tuning in Halide, a state-of-the-art language and compiler for image processing pipelines. For a camera raw image processing pipeline, our performance is comparable to that of a hand-tuned implementation.
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Bentonite is a preferred buffer and backfill material for deep geological disposal of high-level nuclear waste (HLW). Bentonite does not retain anions by virtue of its negatively charged basal surface. Imparting anion retention ability to bentonite is important to enable the expansive clay to retain long-lived I-129 (iodine-129; half-life = 16 million years) species that may escape from the HLW geological repository. Silver-kaolinite (AgK) material is prepared as an additive to improve the iodide retention capacity of bentonite. The AgK is prepared by heating kaolinite-silver nitrate mix at 400 degrees C to study the kaolinite influence on the transition metal ion when reacting at its dehydroxylation temperature. Thermo gravimetric-Evolved Gas Detection analysis, X-ray diffraction analysis, X-ray photo electron spectroscopy and electron probe micro analysis indicated that silver occurs as AgO/Ag2O surface coating on thermally reacting kaolinite with silver nitrate at 400 degrees C.
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The polyhedral model provides an expressive intermediate representation that is convenient for the analysis and subsequent transformation of affine loop nests. Several heuristics exist for achieving complex program transformations in this model. However, there is also considerable scope to utilize this model to tackle the problem of automatic memory footprint optimization. In this paper, we present a new automatic storage optimization technique which can be used to achieve both intra-array as well as inter-array storage reuse with a pre-determined schedule for the computation. Our approach works by finding statement-wise storage partitioning hyper planes that partition a unified global array space so that values with overlapping live ranges are not mapped to the same partition. Our heuristic is driven by a fourfold objective function which not only minimizes the dimensionality and storage requirements of arrays required for each high-level statement, but also maximizes inter statement storage reuse. The storage mappings obtained using our heuristic can be asymptotically better than those obtained by any existing technique. We implement our technique and demonstrate its practical impact by evaluating its effectiveness on several benchmarks chosen from the domains of image processing, stencil computations, and high-performance computing.
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The effects of curvature and wrinkling on the growth of turbulent premixed flame kernels were studied using both two-dimensional OH Planar Laser-Induced Fluorescence (PLIF) and three-dimensional Direct Numerical Simulation (DNS). Comparisons of results between the two approaches showed a high level of agreement, providing confidence in the simplified chemistry treatment employed in the DNS, and indicating that chemistry might have only a limited influence on the evolution of the freely propagating flame. The usefulness of PLIF in providing data over a wide parameter range was illustrated using statistics obtained from both CH4/air and H2/air mixtures, which show markedly different behavior due to their different thermo-diffusive properties. The results provided a demonstration of the combined power of PLIF and DNS for flame investigation. Each technique compensate for the weaknesses of the other, and to reinforce the strengths of both.
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The 30,000 km2 province of Luristan is situated in western Iran and encompasses the upper valleys of the Zagros Mountains. Even today, local tribesmen inhabit Luristan with their settlement patterns similar to ancient times. Several scientific excavations in the Luristan region have uncovered evidence that this particular region was a major attraction for human settlements from the Paleolithic era onwards. In Ancient Iran, the existence of rich mines together with discoveries made by innovative and inventive artisans spurred the growth of the metalworking culture as an art and a skill among early human communities in Ancient Iran. The art of Luristan can be described as the art of nomadic herdsmen and horsemen with an emphasis on the crafting of small, easily portable objects, among these a number of bronze daggers, swords and other weapons. Throughout its history, Luristan was never an ethnic or political entity because Luristan has been occupied by various tribes and races, throughout its history. Next to Elamites, other tribes who inhabited Luristan were the Hurrians, Lullubians, Kutians, and Kassites. As local tribesmen of Luristan were illiterate, information about their history can only be partially reconstructed from the literature of their southern neighbors: the Elamites and Babylonians. Luristan smiths made weapons for both civilizations. The region was later invaded by Assyrians and finally the Iranians settled the area and absorbed the local tribes. Following an accidental find by the local inhabitants in Luristan in 1928 CE, a number of unlawful diggings reveal a number of metal objects made of bronze and iron that showed a high level of craftsmanship. These objects were offered for sale on the art market with fancy names to hide their origin. The subsequent scientific excavations several decades after the initial discovery provided fascinating information about the culture of Luristan. The metalworking art of Luristan spans a time period from the third millennium BC to the Iron Age. The artifacts from Luristan seem to possess many unique and distinctive qualities, and are especially noteworthy for the apparently endless, intricate diversity and detail that they characteristically depict. The bronze artifacts found in or attributed to Luristan can be each be classed under five separate heads: a) arms and armor, including swords, dirks, daggers, axes, mace heads, spearheads, shields, quiver plaques, protective bronze girdles, helmets; b) implements related to horsemanship, including decorative or ornamental objects for horses as well as bits and snaffles; c) items for personal adornment and hygiene, including anklets, bangles, bracelets, finger rings, earrings and tweezers; d) ceremonial and ritual objects, including talismans, idols, pins, anthropomorphic and zoomorphic figurines; and e) utilitarian objects comprising various vessels and tools, including beakers, bowls and jugs. The scope of this article is limited to a discussion of the bronze and iron weapons made in Luristan. The techniques used for making bronze weapons in Luristan included: casting with open molds, casting with close molds, and casting with lost wax process. For metal sheets used for quiver plaques and bronze protective belts, the hammering technique was used. Edged weapons made in Luristan can be classified into: a) daggers, dirks, and swords with tangs; b) daggers, dirks, and swords with flanges; and c) daggers, dirks, and swords with cast-on hilts. Next to bronze, iron was also used for making weapons such as the characteristic weapon from this area, the iron mask sword.
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Resumen: El análisis de los indicadores de ingresos, desigualdad y pobreza en cada uno de los 32 centros urbanos muestra las grandes disparidades regionales de la Argentina. En la Zona Norte del país el ingreso per capita es un 35% inferior al promedio nacional, la pobreza es 4 veces mayor que en la capital y la distribución del ingreso es más desigual. Los datos estadísticos disponibles indican que el crecimiento económico y las políticas públicas que se han implementado recientemente han reducido los niveles de pobreza agregados, pero han tenido poco impacto en las regiones más pobres del país. Por otra parte, el impacto distributivo de las políticas y programas públicos en la Argentina es reducido cuando se los compara con lo que sucede en los países mas desarrollados. Se requiere el diseño y la implementación de nuevas políticas públicas de reducción de la pobreza que se focalicen en los problemas y dificultades específicas que enfrentan las regiones más pobres. Entre ellas se destaca la necesidad de políticas para disminuir la alta informalidad del empleo que caracteriza a estas zonas. Por otra parte, las nuevas políticas deberían transferir las responsabilidades y premiar los esfuerzos propios de los gobiernos locales, reemplazando la actual “cultura de la dependencia” de los programas del gobierno central por un desarrollo institucional local que enfatice la gestión eficiente de las administraciones públicas provinciales y el desarrollo del capital social local.
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El presente estudio plantea como objetivo evaluar la comprensión de emociones en niños, aspecto central del funcionamiento reflexivo, a través del Test de Rorschach. Para lograrlo se seleccionó una muestra de 30 niños a quienes se administró el “Test of Emotion Comprehension” y el Test de Rorschach. Se presentan los resultados obtenidos a partir de la correlación entre los datos arrojados por ambas técnicas, lo cual permitió identificar determinados indicadores Rorschach (determinantes/ contenidos/ localizaciones/ cómputos) que se modifican de acuerdo al nivel de comprensión de emociones del niño y que, por ende, podrían resultar útiles para evaluarlo. Además, dichos resultados muestran que los niños con alto nivel de comprensión de emociones presentan un protocolo Rorschach mucho más rico, de lo cual se deduce la presencia de mayor cantidad de recursos emocionales en este grupo en comparación con los niños de bajo nivel de comprensión de emociones.
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Uma questão central em uma democracia é descobrir o que leva os eleitores a decidir por um candidato em vez de outro. Em democracias já estabelecidas, fatores como a identificação partidária e o elevado nível de informações disponíveis durante a campanha diminuem a possibilidade de persuasão dos eleitores. Já nas novas democracias, como é o caso do Brasil, acredita-se que a identificação partidária é baixa e, por conta disso, os eleitores têm dificuldades em associar determinadas questões aos partidos políticos. No presente artigo busca-se verificar se há indícios da associação de questões aos partidos políticos durante as campanhas presidenciais no Brasil de 2002 a 2010
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This paper investigates the relationship between linguistic polarization and conflict in the Basque Country. During the 40 years of Franco’s dictatorship the use of the Basque language was banned. Therefore, there may be some linguistic roots underlying the conflict in the Basque Country. We show that at the municipality level, linguistic polarization reduces the level of conflict. This finding is robust to various ways of measuring linguistic and ideological polarization and the inclusion of other covariates. In addition, we find that a high level of the stock of human capital is beneficial for reducing conflict intensity.
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[Es] Las habilidades sociales, o habilidades interpersonales, han sido objeto de creciente interés durante los últimos años en psicología social, clínica y educativa; y, sin embargo, tanto su evaluación como la intervención psicológica para su mejora se topan con una desconcertante proliferación de clasificaciones o categorías divergentes de las mismas. En este trabajo, y como resultado de sucesivos análisis factoriales, se proponen cinco grandes categorías de habilidades sociales (Interacción con personas desconocidas en situaciones de consumo, Interacción con personas que atraen, Interacción con amigos y compañeros, Interacción con familiares, y Hacer y rechazar peticiones a los amigos/as) que responden a distintos contextos de interacción social. Las cinco escalas, correspondientes a tales categorías, de un nuevo instrumento de medida, el Cuestionario de Dificultades Interpersonales (CDI), con alta consistencia interna (·= 0,896), explican el 47,47% de la varianza total. Los análisis correlacionales entre el CDI y el Test de Autoverbalizaciones en la Interacción Social (SISST) de Glass, Merluzzi, Biever y Larsen (1982) revelan diferencias cognitivas significativas entre los sujetos de alta y baja habilidad social, dándose una mayor frecuencia de autoverbalizaciones positivas y una menor frecuencia de autoverbalizaciones negativas en los sujetos de alta habilidad social que en los sujetos de baja habilidad social.
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