110 resultados para ROMS


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Temple Emanuel was founded in 1920 in Lawrence, Massachusetts. It began by serving a small immigrant Jewish community that has since grown to an affluent and lively congregation of about 600 families. This growth occurred largely under the tenure of Rabbi Harry A. Roth, who lead the congregation from 1962 until 1990 and oversaw the temple’s move to Andover, Massachusetts. This collection includes correspondence, photographs, and sermons.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

CD-ROMs have proliferated as a distribution media for desktop machines for a large variety of multimedia applications (targeted for a single-user environment) like encyclopedias, magazines and games. With CD-ROM capacities up to 3 GB being available in the near future, they will form an integral part of Video on Demand (VoD) servers to store full-length movies and multimedia. In the first section of this paper we look at issues related to the single- user desktop environment. Since these multimedia applications are highly interactive in nature, we take a pragmatic approach, and have made a detailed study of the multimedia application behavior in terms of the I/O request patterns generated to the CD-ROM subsystem by tracing these patterns. We discuss prefetch buffer design and seek time characteristics in the context of the analysis of these traces. We also propose an adaptive main-memory hosted cache that receives caching hints from the application to reduce the latency when the user moves from one node of the hyper graph to another. In the second section we look at the use of CD-ROM in a VoD server and discuss the problem of scheduling multiple request streams and buffer management in this scenario. We adapt the C-SCAN (Circular SCAN) algorithm to suit the CD-ROM drive characteristics and prove that it is optimal in terms of buffer size management. We provide computationally inexpensive relations by which this algorithm can be implemented. We then propose an admission control algorithm which admits new request streams without disrupting the continuity of playback of the previous request streams. The algorithm also supports operations such as fast forward and replay. Finally, we discuss the problem of optimal placement of MPEG streams on CD-ROMs in the third section.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

CDS/ISIS is an advanced non-numerical information storage and retrieval software developed by UNESCO since 1985 to satisfy the need expressed by many institutions, especially in developing countries, to be able to streamline their information processing activities by using modern (and relatively inexpensive) technologies [1]. CDS/ISIS is available for MS-DOS, Windows and Unix operating system platforms. The formatting language of CDS/ISIS is one of its several strengths. It is not only used for formatting records for display but is also used for creating customized indexes. CDS/ISIS by itself does not facilitate in publishing its databases on the Internet nor does it facilitate in publishing on CD-ROMs. However, numbers of open source tools are now available, which enables in publishing CDS/ISIS databases on the Internet and also on CD-ROMs. In this paper, we have discussed the ways and means of integrating CDS/ISIS databases with GSDL, an open source digital library (DL) software.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Radio and sonic telemetry were used to investigate the tidal orientation, rate of movement (ROM), and surfacing behavior of nine Kemp's ridley turtles, Lepidochelys kempii, tracked east of the Cedar Keys, Florida. The mean of mean turtle bearings on incoming (48 ± 49 0) and falling (232 ± 41 0) tides was significantly oriented to the mean directions of tidal flow (37±9°, P<0.0025, and 234±9 0, P<0.005, respectively). Turtles had a mean ROM of 0.44±0.33 km/h (range: 0.004-1.758 km/h), a mean surface duration of 18± 15 s (range: 1-88 s), and a mean submergence duration of 8.4± 6.4 min (range: 0.2-60.0 min). ROM was negatively correlated with surface and submergence durations and positively correlated with the number of surfacings. Furthermore, ROMs were higher and surface and submergence durations were shorter during the day. Daily activities of turtles were attributed to food acquisition and bioenergetics.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The mixed layer depth (MLD) in the upper ocean is an important physical parameter for describing the upper ocean mixed layer. We analyzed several major factors influencing the climatological mixed layer depth (CMLD), and established a numerical simulation in the South China Sea (SCS) using the Regional Ocean Model System (ROMS) with a high-resolution (1/12A degrees x1/12A degrees) grid nesting method and 50 vertical layers. Several ideal numerical experiments were tested by modifying the existing sea surface boundary conditions. Especially, we analyzed the sensitivity of the results simulated for the CMLD with factors of sea surface wind stress (SSWS), sea surface net heat flux (SSNHF), and the difference between evaporation and precipitation (DEP). The result shows that of the three factors that change the depth of the CMLD, SSWS is in the first place, when ignoring the impact of SSWS, CMLD will change by 26% on average, and its effect is always to deepen the CMLD; the next comes SSNHF (13%) for deepening the CMLD in October to January and shallowing the CMLD in February to September; and the DEP comes in the third (only 2%). Moreover, we analyzed the temporal and spatial characteristics of CMLD and compared the simulation result with the ARGO observational data. The results indicate that ROMS is applicable for studying CMLD in the SCS area.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

To investigate the seasonal and interannual variations in biological productivity in the South China Sea (SCS), a Pacific basin-wide physical - biogeochemical model has been developed and used to estimate the biological productivity and export flux in the SCS. The Pacific circulation model, based on the Regional Ocean Model Systems (ROMS), is forced with daily air-sea fluxes derived from the NCEP (National Centers for Environmental Prediction) reanalysis between 1990 and 2004. The biogeochemical processes are simulated with a carbon, Si(OH)(4), and nitrogen ecosystem (CoSiNE) model consisting of silicate, nitrate, ammonium, two phytoplankton groups (small phytoplankton and large phytoplankton), two zooplankton grazers (small micrograzers and large mesozooplankton), and two detritus pools. The ROMS-CoSiNE model favourably reproduces many of the observed features, such as ChI a, nutrients, and primary production (PP) in the SCS. The modelled depth-integrated PP over the euphotic zone (0-125 m) varies seasonally, with the highest value of 386 mg C m (-2) d (-1) during winter and the lowest value of 156 mg C m (-2) d (-1) during early summer. The annual mean value is 196 mg C m (-2) d (-1). The model-integrated annual mean new production (uptake of nitrate), in carbon units, is 64.4 mg C m (-2) d (-1) which yields an f-ratio of 0.33 for the entire SCS. The modelled export ratio (e-ratio: the ratio of export to PP) is 0.24 for the basin-wide SCS. The year-to-year variation of biological productivity in the SCS is weaker than the seasonal variation. The large phytoplankton group tends to dominate over the smaller phytoplankton group, and likely plays an important role in determining the interannual variability of primary and new production.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Esta comunicação está inserida no desenvolvimento de um projecto de investigação que procura compreender a forma como os professores de matemática podem integrar o uso de materiais tecnológicos em benefício da aprendizagem dos alunos. O projecto centra-se essencialmente nos materiais electrónicos que acompanham os manuais escolares, CD-Roms, eBooks, portais, filmes e conjuntos de outras actividades que apelam ao uso do computador. Procura-se compreender o papel que estes materiais desempenham no processo de ensino aprendizagem, nomeadamente na forma como os professores se apropriam desses materiais e o uso que fazem dos mesmos na sala de aula. Procurar-se-á apresentar nesta comunicação um breve enquadramento teórico do tema em estudo indicando as principais opções assumidas pelos autores.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Thermal comfort is defined as “that condition of mind which expresses satisfaction with the thermal environment’ [1] [2]. Field studies have been completed in order to establish the governing conditions for thermal comfort [3]. These studies showed that the internal climate of a room was the strongest factor in establishing thermal comfort. Direct manipulation of the internal climate is necessary to retain an acceptable level of thermal comfort. In order for Building Energy Management Systems (BEMS) strategies to be efficiently utilised it is necessary to have the ability to predict the effect that activating a heating/cooling source (radiators, windows and doors) will have on the room. The numerical modelling of the domain can be challenging due to necessity to capture temperature stratification and/or different heat sources (radiators, computers and human beings). Computational Fluid Dynamic (CFD) models are usually utilised for this function because they provide the level of details required. Although they provide the necessary level of accuracy these models tend to be highly computationally expensive especially when transient behaviour needs to be analysed. Consequently they cannot be integrated in BEMS. This paper presents and describes validation of a CFD-ROM method for real-time simulations of building thermal performance. The CFD-ROM method involves the automatic extraction and solution of reduced order models (ROMs) from validated CFD simulations. The test case used in this work is a room of the Environmental Research Institute (ERI) Building at the University College Cork (UCC). ROMs have shown that they are sufficiently accurate with a total error of less than 1% and successfully retain a satisfactory representation of the phenomena modelled. The number of zones in a ROM defines the size and complexity of that ROM. It has been observed that ROMs with a higher number of zones produce more accurate results. As each ROM has a time to solution of less than 20 seconds they can be integrated into the BEMS of a building which opens the potential to real time physics based building energy modelling.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Reduced Order Models (ROMs) have proven to be a valid and efficient approach to model the thermal behaviour of building zones. The main issues associated with the use of zonal/lumped models are how to (1) divide the domain (lumps) and (2) evaluate the pa- rameters which characterise the lump-to-lump exchange of energy and momentum. The object of this research is to develop a methodology for the generation of ROMs from CFD models. The lumps of the ROM and their average property values are automatically ex- tracted from the CFD models through user defined constraints. This methodology has been applied to validated CFD models of a zone of the Environmental Research Insti- tute (ERI) Building in University College Cork (UCC). The ROM predicts temperature distribution in the domain with an average error lower than 2%. It is computationally efficient with an execution time of 3.45 seconds. Future steps in this research will be the development of the procedure to automatically extract the parameters which define lump-to-lump energy and momentum exchange. At the moment these parameters are evaluated through the minimisation of a cost function. The ROMs will also be utilised to predict the transient thermal behaviour of the building zone.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Accurate modelling of the internal climate of buildings is essential if Building Energy Management Systems (BEMS) are to efficiently maintain adequate thermal comfort. Computational fluid dynamics (CFD) models are usually utilised to predict internal climate. Nevertheless CFD models, although providing the necessary level of accuracy, are highly computationally expensive, and cannot practically be integrated in BEMS. This paper presents and describes validation of a CFD-ROM method for real-time simulations of building thermal performance. The CFD-ROM method involves the automatic extraction and solution of reduced order models (ROMs) from validated CFD simulations. ROMs are shown to be adequately accurate with a total error below 5% and to retain satisfactory representation of the phenomena modelled. Each ROM has a time to solution under 20seconds, which opens the potential of their integration with BEMS, giving real-time physics-based building energy modelling. A parameter study was conducted to investigate the applicability of the extracted ROM to initial boundary conditions different from those from which it was extracted. The results show that the ROMs retained satisfactory total errors when the initial conditions in the room were varied by ±5°C. This allows the production of a finite number of ROMs with the ability to rapidly model many possible scenarios.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Este trabalho combina esforços de simulação numérica e de análise de dados para investigar a dinâmica em diversos compartimentos (oceano aberto, plataforma continental e zona costeira-estuarina) e, em multiplas escalas, na Margem Continental Leste Brasileira (MCLB). A circulação de largo e mesoescala espacial e a propagação da maré barotrópica são investigadas através de uma configuração aninhada do modelo numérico ROMS. O estudo da dinâmica regional da Baía de Camamu (CMB) baseia-se na análise de dados locais. A MCLB, localizada a SW do Atlântico Sul entre 8±S e 20±S, possui plataforma estreita, batimetria complexa, e baixa produtividade primária. A sua dinâmica é influenciada pela divergência da Corrente Sul Equatorial (CSE). As simulações refletem as conexões sazonais e espaciais entre a Corrente do Brasil e a Contra Corrente Norte do Brasil , em conexão com a dinâmica da CSE. As simulações revelam atividades vorticais nas proximidades da costa e interações com a dinâmica costeira, cujos padrões são descritos. A validação do modelo em mesoescala é baseada em cálculos de energia cinética turbulenta e em dados históricos de transporte. A CMB, localizada a 13±400S, abriga uma comunidade piscatória tradicional e extenso de manguezal. Situa-se porém sobre uma bacia sedimentar com grande reservas de óleo e gás, estando em tensão permanente de impacto ambiental. Neste trabalho sumarizamos as condições físicas regionais e investigamos sua dinâmica interna, focando sua variabilidade em amostragens realizadas sob condições de seca (Setembro de 2004) e de chuva (Julho de 2005). Finalmente, o modelo numérico ROMS é forçado com o sinal de maré, empregando-se uma configuração simples (com coeficientes de atrito de fundo constantes e condições hidrográficas homogéneas), com o intuito de avaliar sua resposta e investigar a natureza da propagação da maré barotrópica na MCLB, convergindo na CMB. A análise da resposta do modelo à maré basea-se em séries históricas do nível do mar para a MCLB e dados recentes da CMB.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Tese de doutoramento, Ciências Geofísicas e da Geoinformação (Oceanografia), Universidade de Lisboa, Faculdade de Ciências, 2014

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Nesta dissertação pretende-se contribuir para a compreensão do papel do professor na integração de novos materiais didáticos na sua prática pedagógica, em particular dos modos como desenvolvem e aplicam ferramentas didáticas para utilizar novos recursos tecnológicos (CD-ROMs e portais web). Recorrendo ao paradigma da teoria da atividade, o problema central é a caracterização dos processos através dos quais os professores replicam, adaptam e improvisam tarefas com utilização dos recursos tecnológicos e envolve cinco objetivos: 1. Identificar os esquemas de utilização dos professores nas ações mediadas por estes recursos tecnológicos. 2. Identificar os tipos de interação entre os professores e estes recursos tecnológicos. 3. Identificar as orquestrações instrumentais que os professores utilizam quando trabalham com estes recursos tecnológicos. 4. Promover o desenvolvimento pessoal e profissional dos professores em contexto de formação contínua. 5. Refinar o protótipo de "uma ferramenta de análise de tarefas" para fornecer retorno aos professores. Para atingir estes objetivos a investigadora no papel de formadora acompanhou professores de matemática do ensino secundário português na apreciação de tarefas didáticas envolvendo o uso de novos recursos tecnológicos e na análise dos retornos (feedback) dos desempenhos didáticos depois da sua implementação na aula. Este retorno foi obtido através dos seus pares, dos formadores e da reflexão dos professores sobre as ações desenvolvidas nas aulas que ocorreu durante as sessões das ações de formação. Foi utilizada uma metodologia de cariz interpretativo. O estudo mostra que os professores planificam tarefas que integram os recursos tecnológicos e as aplicam nas aulas adequando-as aos ambientes tecnológicos das suas escolas. No entanto, revelam algumas dificuldades em interpretar os retornos. Com base na análise dos dados foi desenvolvido um instrumento de apoio à construção de ferramentas didáticas complementando um outro proposto por Brigit Pepin e que pode ser usado na autoformação ou em ações de formação contínua.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Thèse de doctorat réalisée en cotutelle avec la Faculté de droit de l'Université Aix-Marseille 3.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Resumen basado en la publicación