921 resultados para path continuity


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2000 Mathematics Subject Classification: 60G18, 60E07

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11TH INTERNATIONAL COLLOQUIUM ON ANCIENT MOSAICS OCTOBER 16TH  20TH, 2009, BURSA TURKEY Mosaics of Turkey and Parallel Developments in the Rest of the Ancient and Medieval World: Questions of Iconography, Style and Technique from the Beginnings of Mosaic until the Late Byzantine Era

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This paper addresses the problem of survivable lightpath provisioning in wavelength-division-multiplexing (WDM) mesh networks, taking into consideration optical-layer protection and some realistic optical signal quality constraints. The investigated networks use sparsely placed optical–electrical–optical (O/E/O) modules for regeneration and wavelength conversion. Given a fixed network topology with a number of sparsely placed O/E/O modules and a set of connection requests, a pair of link-disjoint lightpaths is established for each connection. Due to physical impairments and wavelength continuity, both the working and protection lightpaths need to be regenerated at some intermediate nodes to overcome signal quality degradation and wavelength contention. In the present paper, resource-efficient provisioning solutions are achieved with the objective of maximizing resource sharing. The authors propose a resource-sharing scheme that supports three kinds of resource-sharing scenarios, including a conventional wavelength-link sharing scenario, which shares wavelength links between protection lightpaths, and two new scenarios, which share O/E/O modules between protection lightpaths and between working and protection lightpaths. An integer linear programming (ILP)-based solution approach is used to find optimal solutions. The authors also propose a local optimization heuristic approach and a tabu search heuristic approach to solve this problem for real-world, large mesh networks. Numerical results show that our solution approaches work well under a variety of network settings and achieves a high level of resource-sharing rates (over 60% for O/E/O modules and over 30% for wavelength links), which translate into great savings in network costs.

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This study investigates topology optimization of energy absorbing structures in which material damage is accounted for in the optimization process. The optimization objective is to design the lightest structures that are able to absorb the required mechanical energy. A structural continuity constraint check is introduced that is able to detect when no feasible load path remains in the finite element model, usually as a result of large scale fracture. This assures that designs do not fail when loaded under the conditions prescribed in the design requirements. This continuity constraint check is automated and requires no intervention from the analyst once the optimization process is initiated. Consequently, the optimization algorithm proceeds towards evolving an energy absorbing structure with the minimum structural mass that is not susceptible to global structural failure. A method is also introduced to determine when the optimization process should halt. The method identifies when the optimization method has plateaued and is no longer likely to provide improved designs if continued for further iterations. This provides the designer with a rational method to determine the necessary time to run the optimization and avoid wasting computational resources on unnecessary iterations. A case study is presented to demonstrate the use of this method.

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In today’s world heritage worldwide are at the risk not only because of natural process of decay and destruction but also by social change like urbanization, globalization and homogenization of cultures. With these emerging problems, the heritage conservation discourse also has reached to a new dimension including broader range of concepts like tangible heritage, intangible heritage, community participation, indigenous knowledge and many more. Even with the changing scenario in the international context about the heritage conservation, Nepal’s heritage conservation still focus on monuments, sites and buildings. In add to that the conservation practices are still top-down approach and community involvements are limited only in plans. While numerous intangible heritages like masking dances chariot processions, festivals and rituals, which form an integral part of the daily social life of people are still being continued and managed by the community and its people, without with out serious attention form the government. In Kathmandu Valley these heritages has been maintained with the traditional social association of people known as “Guthi” which has been continuing since 5th Century. Most of the tangible and intangible heritages have survived for centuries because of this unique association of people. Among the numerous festivals of the Kathmandu Valley, the festival Yenya Punhi was chosen as a case for this study, which is also a major festival of Kathmandu. This festival is the perfect example for the study as its celebrated in the city that is the most urbanized city of Nepal with the challenges of the every modern city like social changes and urbanization. Despite modern challenges Guthi still plays a major role in the heritage conservation in Kathmandu Valley. Now there are some interventions of the various formal institutions. So this study will be focusing on the management, continuity and problems of the festival along with Nepal’s position in terms of intangible heritage conservation. The problem of Kathmandu and Yenya Punhi festival is the problem of every country in the similar situation so with this case study it can be a good example for finding solutions of the similar problem not only the other festivals within Nepal but also elsewhere in the world; Resumo: Conexão de Património: Festival Yenya Punhi um caminho de fortalecimento de identidade: A experiência de Catmandu Nos dias de hoje, os patrimónios mundiais encontram-se em risco, não só devido ao processo natural de degradação e destruição, mas também pelas mudanças sociais, tais como a urbanização, globalização e homogeneização de culturas. Com o emergir destes problemas, o discurso de conservação de Património atingiu também uma nova dimensão, incluíndo uma área mais abrangente de conceitos, como por exemplo, património material, património imaterial, participação da comunidade, conhecimento indígena, entre outros. Mesmo com este cenário de mudança no contexto mundial de conservação do património, a preservação do património do Nepal continua a focar-se em monumentos, sítios e edíficios. A acrescentar a isso, as práticas de conservação ainda têm uma abordagem descendente e os envolvimentos da comunidade são limitados por planificações. Enquanto que os numerosos patrimónios imateriais como danças com máscaras, procissões, festivais e rituais, os quais formam uma parte integral da vida diária social das pessoas que as continuam e as gerem em comunidade, sem uma atenção séria por parte do governo. No Vale de Catmandu, este património tem sido mantido pela associação tradicional de pessoas conhecidas como ''Guthi'' desde o século V. A maior parte destes patrimónios materiais e imateriais tem sobrevivido durante séculos graças a esta associação única de pessoas. Entre os numerosos festivais do Vale de Catmandu, o festival Yenya Puhni foi escolhido para este estudo, pois é também um grande festival em Catmandu. Este festival é o exemplo perfeito para este estudo, pois é celebrado na cidade mais urbanizada do Nepal, com os desafios das cidades modernas tais como mudanças sociais e urbanização. Apesar dos desafios da modernização, os ''Guthi'' ainda desempenham um papel importante na preservação do património do Vale de Catmandu. Agora, existem algumas intervenções de várias instituições formais Então, este estudo irá focar-se na gestão, continuidade e problemas do festival, juntamente com a posição do Nepal em termos de conservação de património imaterial. O problema de Catmandu e do festival Yenya Punhi é o problema de todos os países em situação semelhante então, este estudo pode ser um bom exemplo para encontrar soluções de problemas parecidos, não só em outros festivais no Nepal mas também para qualquer parte do mundo.

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Universidade Estadual de Campinas . Faculdade de Educação Física

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Breast weight has great economic importance in poultry industry, and may be associated with other variables. This work aimed to estimate phenotypic correlations between performance (live body weight at 7 and 28 days, and at slaughter, and depth of the breast muscle measured by ultrasonography), carcass (eviscerated body weight and leg weight) and body composition (heart, liver and abdominal fat weight) traits in a broiler line, and quantify the direct and indirect influence of these traits on breast weight. Path analysis was used by expanding the matrix of partial correlation in coefficients which give the direct influence of one trait on another, regardless the effect of the other traits. The simultaneous maintenance of live body weight at slaughter and eviscerated body weight in the matrix of correlations might be harmful for statistical analysis involving systems of normal equations, like path analysis, due to the observed multicollinearity. The live body weight at slaughter and the depth of the breast muscle as measured by ultrasonography directly affected breast weight and were identified as the most responsible factors for the magnitude of the correlation coefficients obtained between the studied traits and breast weight. Individual pre-selection for these traits could favor an increased breast weight in the future reproducer candidates of this line if the broilers' environmental conditions and housing are maintained, since the live body weight at slaughter and the depth of breast muscle measured by ultrasonography were directly related to breast weight.

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We have measured the azimuthal anisotropy of pi(0) production for 1 < p(T) < 18 GeV/c for Au + Au collisions at root s(NN) = 200 GeV. The observed anisotropy shows a gradual decrease for 3 less than or similar to p(T) less than or similar to 7-10 GeV/c, but remains positive beyond 10 GeV/c. The magnitude of this anisotropy is underpredicted, up to at least similar to 10 GeV/c, by current perturbative QCD (PQCD) energy-loss model calculations. An estimate of the increase in anisotropy expected from initial-geometry modification due to gluon saturation effects and fluctuations is insufficient to account for this discrepancy. Calculations that implement a path-length dependence steeper than what is implied by current PQCD energy-loss models show reasonable agreement with the data.

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This investigation presents a comprehensive characterization of magnetic and transport properties of an interesting superconducting wire, Nb-Ti -Ta, obtained through the solid-state diffusion between Nb-12 at.% Ta alloy and pure Ti. The physical properties obtained from magnetic and transport measurements related to the microstructure unambiguously confirmed a previous proposition that the superconducting currents flow in the center of the diffusion layer, which has a steep composition variation. The determination of the critical field also confirmed that the flux line core size is not constant, and in addition it was possible to determine that, in the center of the layer, the flux line core is smaller than at the borders. A possible core shape design is proposed. Among the wires studied, the one that presented the best critical current density was achieved for a diffusion layer with a composition of about Nb-32% Ti-10% Ta, obtained with a heat treatment at 700 degrees C during 120 h, in agreement with previous studies. It was determined that this wire has the higher upper critical field, indicating that the optimization of the superconducting behavior is related to an intrinsic property of the ternary alloy.

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This work deals with the determination of crack openings in 2D reinforced concrete structures using the Finite Element Method with a smeared rotating crack model or an embedded crack model In the smeared crack model, the strong discontinuity associated with the crack is spread throughout the finite element As is well known, the continuity of the displacement field assumed for these models is incompatible with the actual discontinuity However, this type of model has been used extensively due to the relative computational simplicity it provides by treating cracks in a continuum framework, as well as the reportedly good predictions of reinforced concrete members` structural behavior On the other hand, by enriching the displacement field within each finite element crossed by the crack path, the embedded crack model is able to describe the effects of actual discontinuities (cracks) This paper presents a comparative study of the abilities of these 2D models in predicting the mechanical behavior of reinforced concrete structures Structural responses are compared with experimental results from the literature, including crack patterns, crack openings and rebar stresses predicted by both models

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Simulated annealing (SA) is an optimization technique that can process cost functions with degrees of nonlinearities, discontinuities and stochasticity. It can process arbitrary boundary conditions and constraints imposed on these cost functions. The SA technique is applied to the problem of robot path planning. Three situations are considered here: the path is represented as a polyline; as a Bezier curve; and as a spline interpolated curve. In the proposed SA algorithm, the sensitivity of each continuous parameter is evaluated at each iteration increasing the number of accepted solutions. The sensitivity of each parameter is associated to its probability distribution in the definition of the next candidate. (C) 2010 Elsevier Ltd. All rights reserved.

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Causal inference methods - mainly path analysis and structural equation modeling - offer plant physiologists information about cause-and-effect relationships among plant traits. Recently, an unusual approach to causal inference through stepwise variable selection has been proposed and used in various works on plant physiology. The approach should not be considered correct from a biological point of view. Here, it is explained why stepwise variable selection should not be used for causal inference, and shown what strange conclusions can be drawn based upon the former analysis when one aims to interpret cause-and-effect relationships among plant traits.

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Objective: We compared service consumption, continuity of care and risk of readmission in a record linkage follow-up study of cohorts of patients with schizophrenia and related disorders in Victoria (Australia) and in Groningen (The Netherlands). These areas are interesting to compare because mental health care is in a different stage of deiustitutionalization. More beds are available in Groningen and more community resources are available in Victoria. Method: The cohorts were followed for 4 years, since discharge from inpatient services using record linkage data available in the psychiatric case-registers in both areas. Survival analysis was used to study continuity of care and risk of readmission. Results: Available indicators showed a higher level of continuity of care in Victoria. While the relative risk of readmission was the same in both areas and not affected by aftercare contact after discharge, the number of days spent in hospital was much higher in the Groningen register area. Conclusion: These findings provide further support for earlier reports that the risk of readmission is predominantly affected by attributes of mental illness. However, the duration of admissions, is strongly affected by service system variables, including the provision of continuity of care.

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In this work a new approach for designing planar gradient coils is outlined for the use in an existing MRI apparatus. A technique that allows for gradient field corrections inside the diameter-sensitive volume is deliberated. These corrections are brought about by making changes to the wire paths that constitute the coil windings, and hence, is called the path correction method. The existing well-known target held method is used to gauge the performance of a typical gradient coil. The gradient coil design methodology is demonstrated for planar openable gradient coils that can be inserted into an existing MRI apparatus. The path corrected gradient coil is compared to the coil obtained using the target field method. It is shown that using a wire path correction with optimized variables, winding patterns that can deliver high magnetic gradient field strengths and large imaging regions can be obtained.