839 resultados para Scientific literature -- Evaluation
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This paper presents methodologies for residual strength evaluation of concrete structural components using linear elastic and nonlinear fracture mechanics principles. The effect of cohesive forces due to aggregate bridging has been represented mathematically by employing tension softening models. Various tension softening models such as linear, bilinear, trilinear, exponential and power curve have been described with appropriate expressions. These models have been validated by predicting the remaining life of concrete structural components and comparing with the corresponding experimental values available in the literature. It is observed that the predicted remaining life by using power model and modified bi-linear model is in good agreement with the corresponding experimental values. Residual strength has also been predicted using these tension softening models and observed that the predicted residual strength is in good agreement with the corresponding analytical values in the literature. In general, it is observed that the variation of predicted residual moment with the chosen tension softening model follows the similar trend as in the case of remaining life. Linear model predicts large residual moments followed by trilinear, bilinear and power models.
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Levy flights can be described using a Fokker-Planck equation, which involves a fractional derivative operator in the position coordinate. Such an operator has its natural expression in the Fourier domain. Starting with this, we show that the solution of the equation can be written as a Hamiltonian path integral. Though this has been realized in the literature, the method has not found applications as the path integral appears difficult to evaluate. We show that a method in which one integrates over the position coordinates first, after which integration is performed over the momentum coordinates, can be used to evaluate several path integrals that are of interest. Using this, we evaluate the propagators for (a) free particle, (b) particle subjected to a linear potential, and (c) harmonic potential. In all the three cases, we have obtained results for both overdamped and underdamped cases. DOI: 10.1103/PhysRevE.86.061105
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Pervasive use of pointers in large-scale real-world applications continues to make points-to analysis an important optimization-enabler. Rapid growth of software systems demands a scalable pointer analysis algorithm. A typical inclusion-based points-to analysis iteratively evaluates constraints and computes a points-to solution until a fixpoint. In each iteration, (i) points-to information is propagated across directed edges in a constraint graph G and (ii) more edges are added by processing the points-to constraints. We observe that prioritizing the order in which the information is processed within each of the above two steps can lead to efficient execution of the points-to analysis. While earlier work in the literature focuses only on the propagation order, we argue that the other dimension, that is, prioritizing the constraint processing, can lead to even higher improvements on how fast the fixpoint of the points-to algorithm is reached. This becomes especially important as we prove that finding an optimal sequence for processing the points-to constraints is NP-Complete. The prioritization scheme proposed in this paper is general enough to be applied to any of the existing points-to analyses. Using the prioritization framework developed in this paper, we implement prioritized versions of Andersen's analysis, Deep Propagation, Hardekopf and Lin's Lazy Cycle Detection and Bloom Filter based points-to analysis. In each case, we report significant improvements in the analysis times (33%, 47%, 44%, 20% respectively) as well as the memory requirements for a large suite of programs, including SPEC 2000 benchmarks and five large open source programs.
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A necessary step for the recognition of scanned documents is binarization, which is essentially the segmentation of the document. In order to binarize a scanned document, we can find several algorithms in the literature. What is the best binarization result for a given document image? To answer this question, a user needs to check different binarization algorithms for suitability, since different algorithms may work better for different type of documents. Manually choosing the best from a set of binarized documents is time consuming. To automate the selection of the best segmented document, either we need to use ground-truth of the document or propose an evaluation metric. If ground-truth is available, then precision and recall can be used to choose the best binarized document. What is the case, when ground-truth is not available? Can we come up with a metric which evaluates these binarized documents? Hence, we propose a metric to evaluate binarized document images using eigen value decomposition. We have evaluated this measure on DIBCO and H-DIBCO datasets. The proposed method chooses the best binarized document that is close to the ground-truth of the document.
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Quantitative use of satellite-derived rainfall products for various scientific applications often requires them to be accompanied with an error estimate. Rainfall estimates inferred from low earth orbiting satellites like the Tropical Rainfall Measuring Mission (TRMM) will be subjected to sampling errors of nonnegligible proportions owing to the narrow swath of satellite sensors coupled with a lack of continuous coverage due to infrequent satellite visits. The authors investigate sampling uncertainty of seasonal rainfall estimates from the active sensor of TRMM, namely, Precipitation Radar (PR), based on 11 years of PR 2A25 data product over the Indian subcontinent. In this paper, a statistical bootstrap technique is investigated to estimate the relative sampling errors using the PR data themselves. Results verify power law scaling characteristics of relative sampling errors with respect to space-time scale of measurement. Sampling uncertainty estimates for mean seasonal rainfall were found to exhibit seasonal variations. To give a practical example of the implications of the bootstrap technique, PR relative sampling errors over a subtropical river basin of Mahanadi, India, are examined. Results reveal that the bootstrap technique incurs relative sampling errors < 33% (for the 2 degrees grid), < 36% (for the 1 degrees grid), < 45% (for the 0.5 degrees grid), and < 57% (for the 0.25 degrees grid). With respect to rainfall type, overall sampling uncertainty was found to be dominated by sampling uncertainty due to stratiform rainfall over the basin. The study compares resulting error estimates to those obtained from latin hypercube sampling. Based on this study, the authors conclude that the bootstrap approach can be successfully used for ascertaining relative sampling errors offered by TRMM-like satellites over gauged or ungauged basins lacking in situ validation data. This technique has wider implications for decision making before incorporating microwave orbital data products in basin-scale hydrologic modeling.
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Availability of land for conventional air-insulated substations is becoming increasingly difficult not only in urban but also in semiurban areas. When the land made available is highly uneven, the associated technoeconomic factors favors the erection of substations on a steplike-formed ground surface and such constructions are in service for more than ten years in some parts of southern India. Noting that the literature on the performance of ground grids in such a construction is rather scarce, the present work was taken up. Evaluation of the performance of earthing elements in steplike ground forms the main goal of the present work. For the numerical evaluation, a suitable boundary-based methodology is employed. This method retains the classical Galerkin approach for the conductors, while the interfaces are replaced by equivalent fictitious surface sources defined over unstructured mesh. Details of the implementation of this numerical method, along with special measures to minimize the computation, are presented. The performance of basic earthing elements, such as the driven rod, counterpoise, and simple grids buried in steplike ground, are analyzed and compared with that for the case with uniform soil surface. It is shown that more than the earthing resistances, the step potentials can get significantly affected.
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[EN] This paper focuses on how to initiate discussions of the regulatory gaze in primary school classrooms through the study of characters in literature. It specifically focuses on two renowned characters in Spanish literature: Xola (Bernardo Atxaga) and Iholdi (Mariasun Landa). These characters are composed of a chorus of looks which in turn also look. We shall carefully reflect upon these looks and discuss how we see others, how others see us, and how we would like others to see us.
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222 p. : il.
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The extent of rural women fisherfolks contribution to fisheries was grossly under estimated and certainly under valued. The basis of their involvement in fisheries activities is to make themselves equal partners to men productive and self reliant participants in the process of improving their own and their family living standard and to enable them realize their full potentials. This survey is informed a system of data collection with the aid of questionnaires and analysis. Ninety-six of the questionnaires were administered to women fisher folks in eight fishing communities selected at random. Thirty seven (97) percent of the women fisher folks are between the ages of 25-35 years, 59.4% of them can only read and write in Arabic language and 21.9% only are literature in western education, which is a general characteristic of the rural population in Nigeria. 24.0% of the respondents are in full time fishing activities while 65-5% are fishmongers. They belong to cooperative societies but only 26% indicated to have benefited from loan and credit facilities. 84.4% of the respondents are sustained by the business. The major problems facing women fisherfolks includes poor market price, fish spoilage, high transport cost and lack of access to loan and credit facilities and extension assistance. Solution to these problems will increase their status benefit and development
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A proposta da presente pesquisa teve como objetivo analisar criticamente as melhores práticas de recrutamento e de seleção, direcionadas a pessoas com deficiência, candidatas a emprego em cinco empresas privadas, na cidade do Rio de Janeiro, que possuem em seu quadro de funcionários mais de 100 empregados, sendo assim, obrigadas ao cumprimento da Lei n 8.213/1991, a Lei de Cotas. Analisou-se também o modo como profissionais de Recursos Humanos adquiriram conhecimentos técnicos acerca destas práticas. Parte dos objetivos desta proposta de pesquisa foi identificar as bases desta determinação legal, no que se refere ao amparo técnico aos profissionais de RH no processo seletivo. Neste aspecto, o foco da investigação foi verificar a existência de programas de qualificação para estes profissionais, tendo em vista que a exigência de capacitação está sempre centrada na pessoa com deficiência, quando, na verdade, a carência está presente também nos responsáveis que lidam com este público, por ocasião do seu ingresso nas organizações corporativas. A abordagem metodológica incluiu uma pesquisa de campo com base em dados de entrevistas semi-estruturadas, sendo complementada pela técnica de análise de relato verbal. Seis foram os profissionais de RH escolhidos como participantes da pesquisa e que atuam diretamente na área de recrutamento e de seleção de pessoas com deficiência. Inevitavelmente, estes profissionais de RH se utilizam de instrumentos psicométricos dentre outros, cotidianamente empregados no processo seletivo, inclusive na avaliação de pessoas com deficiência. Os resultados da presente pesquisa apontam que as melhores práticas de recrutamento e de seleção, atualmente em uso, direcionadas a pessoas com deficiência, são discriminatórias, pois os profissionais envolvidos neste processo, por demonstrarem falta de conhecimento acerca de práticas apropriadas, se utilizam dos mesmos procedimentos adotados no atendimento de vagas para o público de pessoas ditas normais. Complementarmente, a revisão da literatura aponta a inexistência de amparo técnico e científico, no sentido de qualificar profissionais responsáveis pelo ingresso e permanência de pessoas com deficiência no mercado de trabalho, confirmando-se, assim, a limitação da ação de política pública em vigor. Por conta desse fato, propõe-se a adoção de ações afirmativas, neste caso de órgãos privados, no sentido de mobilizar esforços em prol da contratação de grupos socialmente excluídos no mercado de trabalho, como é o caso das pessoas com deficiência.
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Background: Neonatal trials remain difficult to conduct for several reasons: in particular the need for study sites to have an existing infrastructure in place, with trained investigators and validated quality procedures to ensure good clinical, laboratory practices and a respect for high ethical standards. The objective of this work was to identify the major criteria considered necessary for selecting neonatal intensive care units that are able to perform drug evaluations competently. Methodology and Main Findings: This Delphi process was conducted with an international multidisciplinary panel of 25 experts from 13 countries, selected to be part of two committees (a scientific committee and an expert committee), in order to validate criteria required to perform drug evaluation in neonates. Eighty six items were initially selected and classified under 7 headings: "NICUs description - Level of care'' (21), "Ability to perform drug trials: NICU organization and processes (15), "Research Experience'' (12), "Scientific competencies and area of expertise'' (8), "Quality Management'' (16), "Training and educational capacity'' (8) and "Public involvement'' (6). Sixty-one items were retained and headings were rearranged after the first round, 34 were selected after the second round. A third round was required to validate 13 additional items. The final set includes 47 items divided under 5 headings. Conclusion: A set of 47 relevant criteria will help to NICUs that want to implement, conduct or participate in drug trials within a neonatal network identify important issues to be aware of. Summary Points: 1) Neonatal trials remain difficult to conduct for several reasons: in particular the need for study sites to have an existing infrastructure in place, with trained investigators and validated quality procedures to ensure good clinical, laboratory practices and a respect for high ethical standards. 2) The present Delphi study was conducted with an international multidisciplinary panel of 25 experts from 13 countries and aims to identify the major criteria considered necessary for selecting neonatal intensive care units (NICUs) that are able to perform drug evaluations competently. 3) Of the 86 items initially selected and classified under 7 headings - "NICUs description - Level of care'' (21), "Ability to perform drug trials: NICU organization and processes (15), "Research Experience'' (12), "Scientific competencies and area of expertise'' (8), "Quality Management'' (16), "Training and educational capacity'' (8) and "Public involvement'' (6) - 47 items were selected following a three rounds Delphi process. 4) The present consensus will help NICUs to implement, conduct or participate in drug trials within a neonatal network.
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The purpose of the project is to improve our understanding about best management practices that can be utilized on diked managed wetlands in Suisun Marsh for reducing the occurrence of low dissolved oxygen (DO) and high methylmercury (MeHg) events associated primarily with fall flood-up practices. Low DO events are of concern because they can lead to undue stress and even mortality of sensitive aquatic organisms. Elevated MeHg levels are of concern because MeHg is a neurotoxin that bio-magnifies up the food chain and can cause deleterious effects to higher trophic level consumers such as piscivorous fish, birds, and mammals (including humans). This study involved two years (2007-2008) of intensive field data collection at two managed wetland sites in northwest Suisun Marsh and their surrounding tidal sloughs, an area with prior documented low DO events. In addition, the study collected limited soils and water quality field data and mapped vegetation for three managed wetland sites in the central interior of Suisun Marsh, for the purpose of examining whether wetlands at other locations exhibit characteristics that could indicate potential for similar concerns. In Year 1 of the study, the objective was to identify the baseline conditions in the managed wetlands and determine which physical management conditions could be modified for Year 2 to reduce low DO and MeHg production issues most effectively. The objective of Year 2 was to evaluate the effectiveness of these modified management actions at reducing production of low DO and elevated MeHg conditions within the managed wetlands and to continue improving understanding of the underlying biogeochemical processes at play. This Final Evaluation Memorandum examined a total of 19 BMPs, 14 involving modified water management operations and the remaining five involving modified soil and vegetation management practices. Some of these BMPs were previously employed and others have not yet been tested. For each BMP this report assesses its efficacy in improving water quality conditions and potential conflicts with wetland management. It makes recommendations for further study (either feasibility assessments or field testing) and whether to consider for future use. Certain previously used BMPs were found to be important contributors to poor water quality conditions and their continued use is not recommended. Some BMPs that could improve water quality conditions appear difficult to implement in regards to compatibility with wetland management; these BMPs require further elaboration and feasibility assessment to determine whether they should be field tested. In practice for any given wetland, there is likely a combination of BMPs that would together have the greatest potential to address the low DO and high MeHg water quality concerns. Consequently, this report makes no sweeping recommendations applicable to large groups of wetlands but instead promotes a careful consideration of factors at each wetland or small groups of wetlands and from that assessment to apply the most effective suite of BMPs. This report also identifies a number of recommended future actions and studies. These recommendations are geared toward improving the process understanding of factors that promote low DO and high MeHg conditions, the extent of these problems in Suisun Marsh, the regulatory basis for the DO standards for a large estuarine marsh, the economics of BMPs, and alternative approaches to BMPs on diked managed wetlands that may address the water quality issues. The most important of these recommendations is that future BMP implementation should be carried out within the context of rigorous scientific evaluation so as to gain the maximum improvement in how to manage these water quality issues in the diked managed wetlands of Suisun Marsh.
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O município de São João da Barra, localizado na mesorregião do norte-fluminense do Estado do Rio de Janeiro, por possuir uma vasta riqueza natural, sobretudo de praias, é um local muito procurado pelo turismo, principalmente no verão, período mais propício à balneabilidade, também atrai uma grande demanda de turistas através de diversos eventos organizados pela prefeitura, como carnaval, acarretando como consequência o desenvolvimento do turismo de massa. Além disso, o município foi escolhido para hospedar o Complexo Logístico e Industrial Portuário do Açu (CLIPA), maior empreendimento porto-indústria da América Latina, e um dos três maiores complexos portuários do mundo, que está em fase de implantação. Diante deste cenário, considerando a necessidade de buscar uma alternativa ao turismo de massa, bem como, proteger este destino turístico dos impactos provocados pelo mesmo, e pelo complexo portuário, a pesquisa teve por objetivo identificar o potencial turístico do município de São João da Barra, com enfoque ao desenvolvimento do turismo alternativo a fim de oferecer subsídios para o planejamento turístico sustentável do local. O trabalho se baseou na metodologia proposta por Braga (2007) referente às etapas do processo de planejamento turístico, que se constituíram em quatro etapas: definição do objeto de estudo e missão do planejamento; inventário da situação atual, diagnóstico, e diretrizes de ação. As análises revelaram, através da pesquisa bibliográfica e empírica área de estudo, os principais impactos socioambientais que ocorrem em São João da Barra, provocados não só pelo turismo, como também pela implantação do complexo portuário e por outras fontes; também foi possível obter a percepção da comunidade acerca de como a atividade turística se desenvolve no local, permitindo a elaboração de diretrizes no contexto da gestão participativa. Além disso, o estudo revelou o grande potencial turístico de modalidades alternativas ao turismo de massa, como o turismo científico, educacional, histórico-cultural e esportivo, através da elaboração do inventário da oferta local e do mapa de localização dos atrativos.
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O papel da religiosidade na determinação do comportamento suicida é controverso, havendo estudos que a consideram um fator protetor e outros um fator de risco. Neste estudo os autores conduziram uma revisão sistemática da literatura para avaliar a relação entre a religiosidade e o comportamento suicida. Dentre os 154 artigos publicados em periódicos científicos inicialmente identificados nas bases Medline, Lilacs, Scielo e PsycInfo, foram selecionados 59 artigos que enfocavam a associação entre religiosidade e comportamento suicida. Para a avaliação dos atributos qualitativos dos artigos foi desenvolvido um Roteiro de Avaliação Qualitativa. Os resultados mostram que grande parte dos artigos encontrados apresentava falta de rigor metodológico na mensuração do conceito de religiosidade, possivelmente devido à característica subjetiva desse constructo. Contudo, verificou-se que o papel protetor contra o comportamento suicida exercido pela religiosidade, sofre variações de acordo com a cultura na qual está inserida, considerando que para algumas culturas o comportamento suicida não é visto com total desaprovação. Porém, a maioria dos estudos reforça a hipótese de que a religiosidade diminui o risco de comportamento suicida nos indivíduos que professam algum tipo de credo e, que participam de algum espaço religioso. Não foram encontrados, nesta pesquisa, estudos que medissem a associação, entre religiosidade e comportamento suicida, em religiões de matriz africana.