Dealing with arithmetic overflows in the polyhedral model

International audienceThe polyhedral model provides techniques to optimize Static Control Programs (SCoP) using some complex transforma- tions which improve data-locality and which can exhibit par- allelism. These advanced transformations are now available in both GCC and LLVM. In this paper, we focus on the cor- rectness of these transformations and in particular on the problem of integer overflows. Indeed, the strength of the polyhedral model is to produce an abstract mathematical representation of a loop nest which allows high-level trans- formations. But this abstract representation is valid only when we ignore the fact that our integers are only machine integers. In this paper, we present a method to deal with this problem of mismatch between the mathematical and concrete representations of loop nests. We assume the exis- tence of polyhedral optimization transformations which are proved to be correct in a world without overflows and we provide a self-verifying compilation function. Rather than verifying the correctness of this function, we use an approach based on a validator, which is a tool that is run by the com- piler after the transformation itself and which confirms that the code produced is equivalent to the original code. As we aim at the formal proof of the validator we implement this validator using the Coq proof assistant as a programming language [4]

Implementar la tecnología BIM en diseño y construcción

Este documento define los pasos para la implementación futura de un proyecto de optimización de herramientas tecnológicas al interior de una empresa de diseño y construcción de proyectos arquitectónicos, por medio de la migración de las técnicas de diseño asistido y coordinación de obras tradicionales, hacia sistemas de reconstrucción virtual, en los cuales la solución de problemas se dan de forma dinámica y anticipada, logrando reducir los impactos por ajustes posteriores de obra o reprocesos asociados a estas actividades dentro de los equipos de trabajo y así mejorar los rendimientos de la empresa en torno a los factores asociados a costo, calidad y tiempo. Así mismo este modelo de ejecución de proyectos, crea un proceso de innovación muy destacado, que permitirá a la empresa dar un gran salto de capacidad técnica y consolidarse en torno al uso de tecnologías de diseño de última generación.This document defines the stages for a future implementation tool associated to a technological actualization inside a design and construction company, through the migration from a traditional design and coordination techniques to a virtual preconstruction system, to solved materialization issues using a dynamic and analytic software, to reduce project adjustments impact associated, seeking to improve company’s performance around cost, quality, and time factors. Likewise, this project execution model will allow the company to make a remarkable advance about technical capacity and new design technologies knowledge

Prueba piloto madera inmunizada

Debido a la poca durabilidad de la madera que se presenta en algunas labores de preparación de la mina de carbón térmico Carboquia S.A.S., localizada en el municipio de Cucunubá, Cundinamarca, surge la inquietud de buscar una solución óptima a este problema en función de mejorar la resistencia a la humedad que tiene que soportar la madera, para disminuir los costos de inversión en sostenimiento al titular minero. A partir del problema identificado se determinaron dos posibles soluciones por medio de una consulta previa en bases de datos y en la mina de los tratamientos más usados en las maderas para mejorar su durabilidad. Se llegó a determinar que una solución es la aplicación de inmunizante Sika y la otra es la aplicación es aceite quemado. Teniendo las dos posibles soluciones, se desarrolló una metodología de investigación para realizar una prueba piloto al tipo de madera que se utiliza en el sostenimiento de la mina, en este caso, eucalipto. Se tomaron cuatro muestras, in situ, de la mina, a las que se les aplicaron los dos inmunizantes, con un tiempo establecido de prueba de 6 días hábiles para obtener resultados y determinar cuál es la solución más óptima para solucionar el problema en la mina Carboquia

Chain transfer to solvent in the radical polymerization of structurally diverse acrylamide monomers using straight-chain and branched alcohols as solvents

Chain transfer to solvent in conventional radical polymerizations of N-tert-butylacrylamide (TBAM) and N-(2-morpholin-4-ylethyl) acrylamide (MEA) in a range of alcohol solvents is investigated. Mayo analysis of polymerization of TBAM in linear alcohols (C-3-C-9) resulted in an approximately linear increase in chain transfer to solvent constant (C-tr,(S)) with the number of methylene (CH2) units in the solvent. The branched alcohol 3-methyl-3-pentanol gave the smallest C-tr,C-S (using Mayo analysis), and thus allowed attainment of higher molecular weights (MWs) in the nitroxide-mediated polymerizations (NMP) of TBAM. Overall, the data show that MEA is more prone to chain transfer to solvent than TBAM (higher C-tr,C-S), and further analysis of the conventional radical polymerization of MEA in 3-methyl-3-pentanol indicate chain transfer to monomer may also be occurring. The first controlled/ living polymerizations of MEA are detailed with chain transfer having a greater impact on maximum achievable MWs in NMP in comparison to TBAM

Synthesis of fluorinated alkoxyamines and alkoxyamine-initiated nitroxide-mediated precipitation polymerizations of styrene in supercritical carbon dioxide

TIPNO (2,2,5-trimethyl-4-phenyl-3-azahexane-3-nitroxide)-alkoxyamine was found to give reasonably controlled/living nitroxide-mediated (NMP) precipitation polymerizations of styrene in supercritical carbon dioxide (scCO(2)). In contrast under the same conditions, the analogous SG1 (N-tert-butyl-N-(1-diethylphosphono-2,2-dimethylpropyl)nitroxide)-alkoxyamine gave higher rates of polymerization and inferior controlled/living character. The circumvention of the requirement for excess free (nitroxide](0) allowed the study of nitroxide partitioning effects in scCO(2) for three newly synthesized fluorinated alkoxyamines. Two alkoxyamines dissociated into scCO(2)-philic fluorinated TIPNO-nitroxide derivatives, while another contains a similar sized fluorinated "foot". Despite the increased steric bulk about the N-O bond for the novel fluorinated alkoxyamines, all polymerizations proceeded at a similar rate and level of control to the TIPNO system in solution (toluene). PREDICI simulations for the styrene/TIPNO system are used to support extensive partitioning effects observed in scCO(2) for the fluorinated alkoxyamines.Irish Research Council (formerly IRCSET) IUPAC Transnational Call in Polymer Chemistry to F.Aldabbagh. National Science Foundation (NSF CHE-1057927, USA) to R. Braslau.peer-reviewe

¿Descendió el producto agrario por habitante en la Europa moderna? El caso castellano

Este trabajo cuantifica el crecimiento del producto agrario y del producto agrario per cápita en cuatro provincias castellanas entre las últimas décadas del siglo XVI y el tercer cuarto del XVIII. Para ello utiliza la vía del producto y se basa en la documentación decimal generada por las diócesis de Ávila, Burgos, Salamanca y Segovia para el reparto del subsidio y del excusado. Su principal conclusión no corrobora la imagen negativa que ofrece parte de la historiografía reciente sobre la evolución del sector primario castellano en los siglos XVI y XVIII: entre 1588-1592 y 1771-1775, tanto el producto agrario como el producto agrario por habitante, lejos de reducirse, crecieron en la región estudiada

Association Between Preexisting Versus Newly Identified Atrial Fibrillation and Outcomes of Patients With Acute Pulmonary Embolism

Background Atrial fibrillation (AF) may exist before or occur early in the course of pulmonary embolism (PE). We determined the PE outcomes based on the presence and timing of AF. Methods and Results Using the data from a multicenter PE registry, we identified 3 groups: (1) those with preexisting AF, (2) patients with new AF within 2 days from acute PE (incident AF), and (3) patients without AF. We assessed the 90-day and 1-year risk of mortality and stroke in patients with AF, compared with those without AF (reference group). Among 16 497 patients with PE, 792 had preexisting AF. These patients had increased odds of 90-day all-cause (odds ratio [OR], 2.81; 95% CI, 2.33-3.38) and PE-related mortality (OR, 2.38; 95% CI, 1.37-4.14) and increased 1-year hazard for ischemic stroke (hazard ratio, 5.48; 95% CI, 3.10-9.69) compared with those without AF. After multivariable adjustment, preexisting AF was associated with significantly increased odds of all-cause mortality (OR, 1.91; 95% CI, 1.57-2.32) but not PE-related mortality (OR, 1.50; 95% CI, 0.85-2.66). Among 16 497 patients with PE, 445 developed new incident AF within 2 days of acute PE. Incident AF was associated with increased odds of 90-day all-cause (OR, 2.28; 95% CI, 1.75-2.97) and PE-related (OR, 3.64; 95% CI, 2.01-6.59) mortality but not stroke. Findings were similar in multivariable analyses. Conclusions In patients with acute symptomatic PE, both preexisting AF and incident AF predict adverse clinical outcomes. The type of adverse outcomes may differ depending on the timing of AF onset.info:eu-repo/semantics/publishedVersio

L’inertie et les changements urbains au prisme des prix du logement : Bogota, 1970-2012

Following the evolution of the gaps in housing and land values between seven sectors of Bogotá between 1970 and 2012, this thesis analyzes the scale of urban socio-spatial transformations. By overlapping urban analysis with the study of real estate markets, this analysis deals with the evolution of already-built areas and their housing prices. In contrast with research that emphasizes the depth and rapidity of transformations in Latin American cities during globalization, our findings show that gaps in housing prices from one area to another remain stable. During the period studied, only in the realm of land value gaps in prices between one area and another did actually widen. The statistical analysis of factors explaining the stability of gaps between housing prices from one area to another reveals that overall stability results from the conjunction of two trends with opposite effects. The spatial diffusion of shopping outlets reduces the gaps in housing prices from one area to another, to the same extent as the symbolic or perceived value of each of these residential areas keeps these gaps in prices entrenched. As for land prices, the densification of buildings explains to some extent the widening gaps in prices between some sectors of the city, but this one factor is not enough to explain the extent of the observed evolutionsA partir de l’évolution des écarts spatiaux des prix du logement et des prix fonciers entre sept secteurs de Bogota, entre 1970 et 2012, cette thèse analyse l’ampleur des recompositions socio-spatiales de la ville. En croisant l’analyse urbaine et l’étude de marchés immobiliers, cette recherche aborde l’évolution des secteurs déjà construits de la ville et les variations des prix des logements anciens. Contrairement aux recherches qui insistent sur la profondeur et la rapidité des transformations des villes latino-américaines sous l’effet de la globalisation, nos résultats montrent que les différences spatiales des prix du logement restent stables. Seuls les écarts spatiaux des prix fonciers augmentent pendant notre période d’étude. L’analyse statistique des facteurs explicatifs de l’inertie des écarts spatiaux des prix montre que la stabilité globale résulte de la conjonction de deux tendances ayant des effets opposés. La diffusion des commerces réduit les écarts spatiaux des prix, alors que la valeur symbolique du secteur de résidence explique le maintien des différences spatiales des prix. Quant aux prix fonciers, la densification des constructions explique une portion des écarts croissants entre secteurs de la ville, mais reste insuffisante pour comprendre l’ampleur des évolutions constatée

An analysis of urban inertia and transformations throught housing prices : Bogotá, 1990-2012

A partir de l’évolution des écarts spatiaux des prix du logement et des prix fonciers entre sept secteurs de Bogota, entre 1970 et 2012, cette thèse analyse l’ampleur des recompositions socio-spatiales de la ville. En croisant l’analyse urbaine et l’étude de marchés immobiliers, cette recherche aborde l’évolution des secteurs déjà construits de la ville et les variations des prix des logements anciens. Contrairement aux recherches qui insistent sur la profondeur et la rapidité des transformations des villes latino-américaines sous l’effet de la globalisation, nos résultats montrent que les différences spatiales des prix du logement restent stables. Seuls les écarts spatiaux des prix fonciers augmentent pendant notre période d’étude. L’analyse statistique des facteurs explicatifs de l’inertie des écarts spatiaux des prix montre que la stabilité globale résulte de la conjonction de deux tendances ayant des effets opposés. La diffusion des commerces réduit les écarts spatiaux des prix, alors que la valeur symbolique du secteur de résidence explique le maintien des différences spatiales des prix. Quant aux prix fonciers, la densification des constructions explique une portion des écarts croissants entre secteurs de la ville, mais reste insuffisante pour comprendre l’ampleur des évolutions constatéesFollowing the evolution of the gaps in housing and land values between seven sectors of Bogotá between 1970 and 2012, this thesis analyzes the scale of urban socio-spatial transformations. By overlapping urban analysis with the study of real estate markets, this analysis deals with the evolution of already-built areas and their housing prices. In contrast with research that emphasizes the depth and rapidity of transformations in Latin American cities during globalization, our findings show that gaps in housing prices from one area to another remain stable. During the period studied, only in the realm of land value gaps in prices between one area and another did actually widen. The statistical analysis of factors explaining the stability of gaps between housing prices from one area to another reveals that overall stability results from the conjunction of two trends with opposite effects. The spatial diffusion of shopping outlets reduces the gaps in housing prices from one area to another, to the same extent as the symbolic or perceived value of each of these residential areas keeps these gaps in prices entrenched. As for land prices, the densification of buildings explains to some extent the widening gaps in prices between some sectors of the city, but this one factor is not enough to explain the extent of the observed evolution

Os avatares da moradia na pesquisa urbana e regional latinoamericana (1990-2012)

La revisión de los términos utilizados como palabras clave de tres revistas, editadas en México y Chile, y los encuentros de investigación urbana y regional brasileños se utilizan para analizar las tendencias de la investigación en vivienda. Su dinámica se interpreta a la luz de las transformaciones  generales identificadas para la investigación urbana y regional, sintetizadas por otros autores como la emergencia de nuevos temas de investigación y agentes del cambio urbano (la sociedad civil, la  participación, el medioambiente, el género) y el proceso de la globalización (en sus facetas de reestructuración  productiva, precarización, distanciamiento social) como contexto general de análisis. Se encuentra que los temas centrales de la investigación en vivienda se relacionan principalmente  con la acción estatal en la vivienda. Las nuevas preocupaciones, como la participación ciudadana,  el medioambiente o el género, se articulan a estas acciones como elementos valorativos de los programas o políticas, mas no   como campos autónomos de estudio de la vivienda. Además de esta preocupación central, se identifican un crecimiento importante de la producción académica y algunos  indicios de la internacionalización de la investigación.A revisão dos termos utilizados como palavras chave de três revistas, editadas no México e no Chile, e os encontros de pesquisa urbana e regional brasileiros utilizam-se para analisar as tendências da pesquisa em moradia. Sua dinâmica interpreta-se à luz das transformações gerais identificadas para a pesquisa urbana e regional, sintetizadas por outros autores como a emergência de novos temas de pesquisa e agentes de mudança urbana (a sociedade civil, a participação, o medioambiente, o gênero) e o processo da globalização (em suas facetas de reestruturação produtiva, precarização, distanciamento social) como contexto geral de análise. Encontra-se que os temas centrais da pesquisa em moradia se relacionam principalmente com a ação estatal na moradia. As novas preocupações, como a participação cidadã, o medioambiente ou o gênero, se articulam a estas ações como elementos valorativos dos programas ou políticas, mas não como campos autônomos de estudo da moradia. Além desta preocupação central, identificam-se um crescimento importante da produção acadêmica e alguns indícios da internacionalização da pesquisa.The review of the terms used as keywords in three journals (published in Mexico and Chile) and the Brazilian meetings of regional and urban research are used to analyze the trends in housing research. Their dynamics are interpreted in the light of the general changes identified for urban and regional  research, synthesized by other authors as the emergence of new research topics and agents of urban change (civil society, participation, environment, gender) and the process of globalization (in its facets  of productive restructuration, job flexibility, social exclusion) as a general framework of analysis. It is found that the central themes of research in housing relate primarily to government action in  housing. New concerns, such as citizen participation, the environment or gender are linked to these actions as normative elements to the evaluation of programs or policies, but not as autonomous fields of study of the housing.In addition to this central concern, a significant growth of academic  production and  ome indication of the internationalization of research are mentione