950 resultados para Missions -- British Columbia.
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The effect of mistuning on the vibration of bladed disks has been extensively studied in the past 30 years. Most of these analysis typically cover the case of small variations of the elastic characteristics (mass and stiffness) of the blades. In this work we study the not so common case of the forced response of a stable rotor with damping mistuning. The Asymptotic Mistuning Model (AMM) is used to analyze this problem. The AMM methodology provides a simplified model that describes the effect of blade to blade damping variation, and gives precise information on the underlying mechanisms involved in the action of damping mistuning.
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This paper presents and illustrates with an example a practical approach to the dataflow analysis of programs written in constraint logic programming (CLP) languages using abstract interpretation. It is first argued that, from the framework point of view, it sufnces to propose relatively simple extensions of traditional analysis methods which have already been proved useful and practical and for which efncient fixpoint algorithms have been developed. This is shown by proposing a simple but quite general extensión of Bruynooghe's traditional framework to the analysis of CLP programs. In this extensión constraints are viewed not as "suspended goals" but rather as new information in the store, following the traditional view of CLP. Using this approach, and as an example of its use, a complete, constraint system independent, abstract analysis is presented for approximating definiteness information. The analysis is in fact of quite general applicability. It has been implemented and used in the analysis of CLP(R) and Prolog-III applications. Results from the implementation of this analysis are also presented.
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Studying independence of literals, variables, and substitutions has proven very useful in the context of logic programming (LP). Here we study independence in the broader context of constraint logic programming (CLP). We show that a naive extrapolation of the LP definitions of independence to CLP is unsatisfactory (in fact, wrong) for two reasons. First, because interaction between variables through constraints is more complex than in the case of logic programming. Second, in order to ensure the efUciency of several optimizations not only must independence of the search space be considered, but also an orthogonal issue - "independence of constraint solving." We clarify these issues by proposing various types of search independence and constraint solver independence, and show how they can be combined to allow different independence-related optimizations, from parallelism to intelligent backtracking. Sufficient conditions for independence which can be evaluated "a-priori" at run-time are also proposed. Our results suggest that independence, provided a suitable definition is chosen, is even more useful in CLP than in LP.
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This paper presents a time-domain stochastic system identification method based on maximum likelihood estimation (MLE) with the expectation maximization (EM) algorithm. The effectiveness of this structural identification method is evaluated through numerical simulation in the context of the ASCE benchmark problem on structural health monitoring. The benchmark structure is a four-story, two-bay by two-bay steel-frame scale model structure built in the Earthquake Engineering Research Laboratory at the University of British Columbia, Canada. This paper focuses on Phase I of the analytical benchmark studies. A MATLAB-based finite element analysis code obtained from the IASC-ASCE SHM Task Group web site is used to calculate the dynamic response of the prototype structure. A number of 100 simulations have been made using this MATLAB-based finite element analysis code in order to evaluate the proposed identification method. There are several techniques to realize system identification. In this work, stochastic subspace identification (SSI)method has been used for comparison. SSI identification method is a well known method and computes accurate estimates of the modal parameters. The principles of the SSI identification method has been introduced in the paper and next the proposed MLE with EM algorithm has been explained in detail. The advantages of the proposed structural identification method can be summarized as follows: (i) the method is based on maximum likelihood, that implies minimum variance estimates; (ii) EM is a computational simpler estimation procedure than other optimization algorithms; (iii) estimate more parameters than SSI, and these estimates are accurate. On the contrary, the main disadvantages of the method are: (i) EM algorithm is an iterative procedure and it consumes time until convergence is reached; and (ii) this method needs starting values for the parameters. Modal parameters (eigenfrequencies, damping ratios and mode shapes) of the benchmark structure have been estimated using both the SSI method and the proposed MLE + EM method. The numerical results show that the proposed method identifies eigenfrequencies, damping ratios and mode shapes reasonably well even in the presence of 10% measurement noises. These modal parameters are more accurate than the SSI estimated modal parameters.
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Spanish Educational Laws have been promoting the widespread use of English; as a result, Spanish Uni versities are looking for ways to give students more international training in order to prepare them for a future that will increasingly involve global problems and partnerships. Therefore, the Polytechnic University of Madrid, Spain (UPM), and the University of British Columbia, Okanagan, Canada (UBCO) have come together to offer opportunities for international collaboration and learning, thus facilitating virtual encounters among Spanish and Canadian students. The Language Exchange Program between the UPM and UBCO acts as a model for sustainability innovation in language and culture engagement as the students can interact with native speakers in communication tasks. This interdisciplinary initiative supports the latest methodological principles observed in the Common European Framework for Languages, such as autonomous and life-long learning, self-assessment and peer-assessment as well as the incorporation of new technologies to the learning process. Additionally the ‘virtual’ mobility is provided at no extra cost. This article presents the preliminary results of two virtual exchange programs that have been offering varied forms of study which are venue-independent, and have clearly expanded the range of scenarios for the students on both sides by promoting collaborative work and cultural exchange.
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Acknowledgments Financial Support: HERU and HSRU receive a core grant from the Chief Scientist’s Office of the Scottish Government Health and Social Care Directorates, and the Centre for Clinical epidemiology & Evaluation is funded by Vancouver Coastal Health Authority. The model used for the illustrative case study in this paper was developed as part of a NHS Technology Assessment Review, funded by the National Institute for Health Research (NIHR) Health Technology Assessment Program (project number 09/146/01). The views and opinions expressed in this paper are those of the authors and do not necessarily reflect those of the Scottish Government, NHS, Vancouver Coastal Health, NIHR HTA Program or the Department of Health. The authors wish to thank Kathleen Boyd and members of the audience at the UK Health Economists Study Group, for comments received on an earlier version of this paper. We also wish to thank Cynthia Fraser (University of Aberdeen) for literature searches undertaken to inform the manuscript, and Mohsen Sadatsafavi (University of British Columbia) for comments on an earlier draft
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Esta investigação teve por objetivo analisar a participação de idosos em direção à promoção da saúde considerando a articulação com oito aspectos da vida urbana do projeto cidade amiga do idoso (espaços abertos e prédios, transporte, moradia, participação social, respeito e inclusão social, participação cívica e emprego, comunicação e informação, e apoio comunitário e serviços de saúde) do bairro Vila Tibério, município de Ribeirão Preto, estado de São Paulo, Brasil. Trata-se de pesquisa descritiva de abordagem qualitativa sustentada pelos conceitos e princípios da promoção da saúde, a partir da perspectiva da participação social e do estabelecimento de ambientes saudáveis, motivo do alinhamento com os aspectos da vida urbana do Projeto Cidade Amiga do Idoso. A pesquisa atendeu aos preceitos éticos, sendo sua realização aprovada por Comitê de Ética em Pesquisa. A captação do empírico se deu por meio da realização de grupos focais com base no Protocolo de Vancouver, desenvolvido pelo Government of British Columbia, somando 32 idosos e 6 representantes de prestadores de serviços em 5 grupos focais. Adicionalmente, foi aplicado instrumento de avaliação funcional para verificar condição de independência ou dependência dos 32 idosos, sendo feita avaliação qualitativa da capacidade autorreferida pelos idosos, segundo a escala utilizada. Realizou-se análise de conteúdo na vertente temática para o material dos grupos, com a identificação de três temas: território: lugar de vida e cidadania, formação de redes de suporte social ao idoso e participação dos idosos na vida do bairro. A violência, o abandono presentes no território, em especial nos espaços coletivos, trazem preocupação e medo aos idosos, pois dificultam a livre circulação no território. Por outro lado, há no bairro certa tradição e possibilidade de serem construídas relações de amizade e apoio, que permitem ao idoso sentir-se acolhido, sendo enfatizado que as relações de amizade e mesmo as institucionalizadas, como por exemplo, o trabalho dos agentes comunitários de saúde, são necessárias às relações de convivência e sustentação na vida dos idosos. É trazida a importância dos jornais do bairro e de seu papel como elemento constitutivo da rede apoio na área de comunicação e informação dentro do território. A vinculação ao mundo do trabalho, com atividades remuneradas, ainda é uma forma que os idosos encontram de se manterem próximos aos amigos e participantes da vida em comunidade. Há dificuldade em ampliar a participação dos idosos por diferentes motivos que vão desde a dificuldade de mobilidade dentro do bairro, acesso à informação sobre as atividades disponíveis, ausência de canais mais ágeis de comunicação, baixa adesão aos processos de participação social no campo da saúde e assistência social, trabalho dos idosos como cuidadores de outros idosos familiares ou de netos. Situações que dificultam maior adesão aos processos de participação social, embora seja assinalada a importância destes processos para a melhoria do bairro. O conjunto dos resultados aponta que os idosos apresentam muitas dificuldades para ampliar sua participação nos processos coletivos no bairro, que por vezes se mostra hostil em suas condições a este grupo. Por outro lado se fazem presentes potencialidades, nas brechas e sugestões que indicam a possibilidade para se situarem no processo de construção da Promoção da Saúde no território em que estão inseridos, utilizando de suas características, perfis de vida e atuação para agir com autonomia e constituírem-se como protagonistas dos processos e de ações no território. Com a ciência dos limites, credita-se a esta investigação a possibilidade de que os elementos aqui discutidos possam oferecer subsídios para que as políticas voltadas ao envelhecimento saudável nos âmbitos da saúde, segurança, educação, assistência social, dentre outras possam se repensadas ou reestruturadas
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Bioaerosols are a subgroup of atmospheric aerosols and are often linked to the spread of human, animal and plant diseases. Bioaerosols also may play an indirect effect on environmental processes, including the formation of precipitation and alteration of the global climate through their role as nuclei for cloud droplet formation. Several types of biological organisms (e.g., fungi and bacteria) have been shown to be effective ice nuclei (IN) and cloud condensation nuclei (CCN). During 21 days in August 2013 we participated in a collaborative international campaign at a rural, coastal site near the village of Ucluelet on the west coast of Vancouver Island, British Columbia, Canada. The experiments were conducted as part of the NETCARE project (the NETwork on Climate and Aerosols: Addressing Key Uncertainties in Remote Canadian Environments), in part to examine cloud nuclei properties of marine aerosol. The study was conducted from a mobile trailer located approximately 100 m from the coast. A suite of aerosol instrumentation was operated for approximately one month. Key instruments utilized as a part of this thesis include the wideband integrated bioaerosol sensor (WIBS-4A) and the multiple orifice uniform deposition impactor (MOUDI) coupled with an off-line droplet freezing technique (DFT) for the measurement of ice nucleation activity of particles in immersion mode. The WIBS measures the concentration and properties of individual fluorescent particles suspended in the air, which can serve as a proxy for airborne biological particle content. Particles shown to be fluorescent by the WIBS instrument were divided into seven categories based on the pattern of fluorescence each particle exhibited in the three fluorescent channels. Results of the WIBS analysis show that the fluorescent particle concentration in the region correlated well with IN number. The fluorescent particle concentration correlated well with the number of particles shown to be ice active as a function of both particle size and freezing temperature. Correlations involving marine aerosols and marine biological activity indicate that the majority of IN measured at the coastal site likely are not from have marine sources.
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Understanding spatial distributions and how environmental conditions influence catch-per-unit-effort (CPUE) is important for increased fishing efficiency and sustainable fisheries management. This study investigated the relationship between CPUE, spatial factors, temperature, and depth using generalized additive models. Combinations of factors, and not one single factor, were frequently included in the best model. Parameters which best described CPUE varied by geographic region. The amount of variance, or deviance, explained by the best models ranged from a low of 29% (halibut, Charlotte region) to a high of 94% (sablefish, Charlotte region). Depth, latitude, and longitude influenced most species in several regions. On the broad geographic scale, depth was associated with CPUE for every species, except dogfish. Latitude and longitude influenced most species, except halibut (Areas 4 A/D), sablefish, and cod. Temperature was important for describing distributions of halibut in Alaska, arrowtooth flounder in British Columbia, dogfish, Alaska skate, and Aleutian skate. The species-habitat relationships revealed in this study can be used to create improved fishing and management strategies.
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La principal imagen del movimiento 15-M viene simbolizada por las acampadas en las plazas de numerosas ciudades españolas, es decir, su apariencia urbana. No obstante, el derecho a la alimentación sana, el consumo responsable, el acceso a la tierra, la conservación de ecosistemas agrarios y la despoblación del medio rural han sido algunas de las temáticas debatidas en el seno del movimiento. Ello demuestra una sustancial preocupación por la cuestión tanto ambiental como agraria, para las cuales se reclaman alternativas desde una perspectiva propiamente rural. Como se pretende hacer ver en este artículo, en el seno del movimiento 15-M las cuestiones urbanas y rurales son indisociables. Entre ellas destaca la reivindicación de la soberanía alimentaria y de la agroecología como horizontes de una transformación en la organización del territorio. En este artículo se sintetizan los aspectos de ruralidad del movimiento 15-M y sus reivindicaciones de carácter social, ambiental y territorial. De manera particular, se consideran las características propias de iniciativas incipientes que se están llevando a cabo en la provincia de Alicante, en el sureste del Estado español, así como de sus interrelaciones con movimientos rurales en el ámbito regional, nacional e internacional.
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This paper explores the paleoseismic record potentially preserved in the upper 40 m of hydraulic piston cores collected in 1996 at two sites in Saanich Inlet, British Columbia, during ocean drilling program (ODP) Leg 169S. The ODP cores are missing 1-2 m of water-rich sediment directly underlying the seafloor, but this sediment is preserved in shorter piston cores collected in 1989 and 1991. The upper part of the ODP cores consists of rhythmically laminated (varved) marine mud with intercalated massive beds, interpreted to be debris flow deposits. Some of the debris flow deposits are linked to past earthquakes, including the 1946 Vancouver Island earthquake (M7.2), a great (M8-9) plate-boundary earthquake at the Cascadia subduction zone in January 1700, and a large crustal or plate-boundary earthquake about 1000 yr ago. Earthquakes may also be responsible for debris flows in about AD 1600, 1500, 1250, 1150, 850, 450, 350, 180, and BC 200, 220, 500, 900, and 1050. If so, the average recurrence interval for moderate to large earthquakes, which trigger debris flows in Saanich Inlet, is about 150 yr. This recurrence interval is broadly consistent with the frequency of moderate to large earthquakes in the region during the historical period. Debris flows, however, can also be triggered by non-seismic processes, making it difficult to assemble a complete earthquake record from the Saanich Inlet cores. We propose that extensive debris flow deposits, emplaced by single large failures or many smaller coincident failures, probably have a seismic origin.