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‣ Impacto da radioterapia torácica na capacidade funcional de pacientes com neoplasia de mama; The impact of radiation therapy on functional capacity in patients with breast cancer

Suesada, Milena Mako
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 13/09/2010 Português
Relevância na Pesquisa
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Introdução: Durante a radioterapia torácica (RT) para o câncer de mama, parte do parênquima pulmonar adjacente a caixa torácica acaba secundariamente sendo incluída no campo de tratamento, podendo cursar com lesões pulmonares e perdas na capacidade funcional. Essas seqüelas necessitam ser mais bem compreendidas, considerando o bom prognóstico da doença. Objetivos: Avaliar o impacto da RT na capacidade funcional em pacientes com neoplasia de mama. Métodos: Estudo prospectivo que incluiu 41 pacientes consecutivas entre Janeiro de 2008 a Julho de 2009. As pacientes foram submetidas a uma avaliação da capacidade respiratória, da capacidade de exercício e tomografia de tórax de alta resolução antes do início e após 3 meses do término do tratamento. Para a avaliação respiratória foram mensurados a força de músculos respiratórios, mobilidade de caixa torácica e prova de função pulmonar completa. A capacidade de exercício foi avaliada através de teste cardiopulmonar de esforço (ergoespirometria). Foram calculados a dose pulmonar média e o volume pulmonar que recebeu uma dose de 25Gy em valor absoluto (V25cm3) e em porcentagem do volume pulmonar total (V25%). Os sintomas respiratórios (pneumonite) e dermatológicos (dermatite) foram classificados de acordo com escalas previamente descritos na literatura na avaliação final. Resultados: Após 3 meses da RT foram encontrados presença de sintomas de pneumonite actínica e dermatite actínica...

‣ Estimativa da capacidade de carga à tração de estacas helicoidais com base no ensaio SPT; Semi-empirical estimation of the uplift capacity of helical piles based on SPT results

Silva, Bruno Canoza da
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 07/07/2014 Português
Relevância na Pesquisa
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Na prática brasileira, usualmente a previsão da capacidade de carga de fundações por estacas é baseada em métodos semi-empíricos, por meio de correlações diretas da resistência de ponta e por atrito lateral ao longo da estaca com os valores de NSPT. Entretanto, no caso de fundações por estacas helicoidais, ainda utilizam-se métodos teóricos que necessitam de valores de parâmetros geotécnicos obtidos indiretamente a partir de correlações com os valores de NSPT (coesão, peso específico, ângulo de atrito, coeficiente de empuxo). Portanto, nesta dissertação foi desenvolvido um método semi-empírico para estimar a capacidade de carga à tração de fundações por estacas helicoidais profundas por meio de correlações diretas com o valor de NSPT do solo de instalação da estaca. Além disso, são apresentados no presente trabalho valores de fator de torque KT, obtidos por análise estatística, para a verificação da capacidade de carga à tração da estaca usando-se medidas do torque necessário para instalá-la no terreno. Nesta pesquisa dois diferentes modelos para estimativa da capacidade de carga foram desenvolvidos e analisados estatisticamente. O estudo das características das amostras de fundações por estacas helicoidais usadas nesta pesquisa permitiu a subdivisão em grupos (tipo de solo e quantidade de hélices) de modo a se obter modelos mais precisos. Com os resultados deste trabalho...

‣ Does absorptive capacity affect project performance? A study based on project management practices, organization learning, and knowledge

Dultra-de-Lima, Ronaldo Gomes
Fonte: Fundação Getúlio Vargas Publicador: Fundação Getúlio Vargas
Tipo: Tese de Doutorado
Português
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The literature has emphasized that absorptive capacity (AC) leads to performance, but in projects its influences still unclear. Additionally, the project success is not well understood by the literature, and AC can be an important mechanism to explain it. Therefore, the purpose of this study is to investigate the effect of absorptive capacity on project performance in the construction industry of São Paulo State. We study this influence through potential and realized absorptive capacity proposed by Zahra and George (2002). For achieving this goal, we use a combination of qualitative and quantitative research. The qualitative research is based on 15 interviews with project managers in different sectors to understand the main constructs and support the next quantitative phase. The content analysis was the technique used to analyze those interviews. In quantitative phase through a survey questionnaire, we collected 157 responses in the construction sector with project managers. The confirmatory factor analysis and hierarchical linear regression were the techniques used to assess the data. Our findings suggest that the realized absorptive capacity has a positive influence on performance, but potential absorptive capacity and the interactions effect have no influence on performance. Moreover...

‣ Estudo comparativo entre o potencial eólico e a energia efetivamente gerada no complexo eólico de Osório; Comparative study of the wind potential and the wind energy generated in osorio wind complex

Pereira, Maurício Vieira da Rocha
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Trabalho de Conclusão de Curso Formato: application/pdf
Português
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O Brasil está se tornando uma potência mundial na geração de energia eólica, no entanto, apresenta poucas informações disponíveis para avaliar a qualidade dos parques eólicos existentes em operação. O presente estudo apresenta indicadores de desempenho do Complexo Eólico de Osório, para o período compreendido entre 2007 e 2010, utilizando a metodologia computacional do WAsP. Inicialmente é feita uma revisão bibliográfica onde são comentados trabalhos disponíveis na literatura, relacionando-os aos principais parâmetros utilizados neste trabalho. A contextualização no panorama eólico brasileiro é feita também neste capítulo. A metodologia baseia-se na seleção da fonte de dados eólicos que melhor representa o regime de ventos na região do complexo eólico e na modelagem numérica do sofware WAsP. Por fim conclui-se que o Complexo Eólico de Osório apresenta índices de desempenho razoáveis e coerentes com o previsto no local de estudo. O valor da razão de energia eólica gerada e prevista dos aerogeradores é de 94.3% e o fator de capacidade anual médio para o período de estudo - 2007 a 2010 - é de 0.29.; Brazil is becoming a world power in wind energy generation, however it has little information available to evaluate the quality of existing wind farms in operation. This paper presents performance indicators about the Osorio Wind Farm for the period between 2007 and 2010...

‣ Power system capacity expansion planning model considering carbon emissions constraints

Giraldo, Diego Adolfo Mejía; Lezama, Jesús María López; Pareja, Luis Alfonso Gallego
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 114-125
Português
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This paper presents a power system capacity expansion planning modelconsidering carbon emissions constraints. In addition to the traditionaltechnical and economical issues usually considered in the planning process, two environmental policies that consist on the taxation and the annual limitsof carbon dioxide (CO 2) emissions are considered. Furthermore, the gradualretirement of old inefficient generation plants has been included. The approachguarantees a cleaner electricity production in the expanded power system ata relatively low cost. The proposed model considers the transmission systemand is applied to a 4-region and 11-region power systems over a 20-yearplanning horizon. Results show practical investment decisions in terms of sustainability and costs.

‣ Canal M-APSK não-coerente de bloco : capacidade e proposta de codificação para receptores iterativos; Blockwise noncoherent M-APSK channel: capacity and coding scheme for iterative receivers

Daniel Carvalho da Cunha
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 26/05/2006 Português
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Em varios sistemas de transmissão passa-faixa, uma recepção coerente satisfatória é dif?cil de ser alcancada. Para alguns destes sistemas, é comum supor que a rotaçãoo de fase introduzida pelo canal é constante durante um bloco de L s?mbolos e que ela varia de maneira independente de bloco a bloco. Este canal é denominado canal não-coerente de bloco. Investigamos a capacidade de um canal não-coerente de bloco utilizando a modulação M-APSK (do inglês, M-ary Amplitude Phase Shift Keying). Apresentamos a caracterização da distribuição de entrada que atinge a capacidade e obtivemos limitantes superiores e inferiores para a mesma. Adicionalmente, desenvolvemos um algoritmo que simultaneamente fornece a distribuição de entrada e os parametros da modulação M-APSK que maximizam a informação mutua com recepção coerente. A investigação da capacidade mostrou que o aumento de L faz a capacidade não-coerente convergir para a coerente. Alem disso, o uso de codificação diferencial torna a convergência mais rapida. Motivados por este comportamento, apresentamos um esquema de codificação eficiente em faixa. Este esquema é formado pela concatenação serial de um codigo LDPC (do ingles, Low-Density Parity Check )...

‣ Comparison of Three Methods for Wind Turbine Capacity Factor Estimation

Ditkovich, Y.; Kuperman, A.
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Publicado em 22/01/2014 Português
Relevância na Pesquisa
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Three approaches to calculating capacity factor of fixed speed wind turbines are reviewed and compared using a case study. The first “quasiexact” approach utilizes discrete wind raw data (in the histogram form) and manufacturer-provided turbine power curve (also in discrete form) to numerically calculate the capacity factor. On the other hand, the second “analytic” approach employs a continuous probability distribution function, fitted to the wind data as well as continuous turbine power curve, resulting from double polynomial fitting of manufacturer-provided power curve data. The latter approach, while being an approximation, can be solved analytically thus providing a valuable insight into aspects, affecting the capacity factor. Moreover, several other merits of wind turbine performance may be derived based on the analytical approach. The third “approximate” approach, valid in case of Rayleigh winds only, employs a nonlinear approximation of the capacity factor versus average wind speed curve, only requiring rated power and rotor diameter of the turbine. It is shown that the results obtained by employing the three approaches are very close, enforcing the validity of the analytically derived approximations, which may be used for wind turbine performance evaluation.

‣ Exercise capacity as an independent risk factor for adverse cardiovascular outcomes among nondiabetic and diabetic patients

Pierre-Louis, Bredy; Guddati, Achuta K.; Khyzar Hayat Syed, Muhammed; Gorospe, Vanessa E.; Manguerra, Mark; Bagchi, Chaitali; Aronow, Wilbert S.; Ahn, Chul
Fonte: Termedia Publishing House Publicador: Termedia Publishing House
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.80874%
Introduction: To investigate if decreased exercise capacity is an independent risk factor for major adverse cardiovascular events (MACE) in diabetics and nondiabetics. Material and methods The association of decreased exercise capacity (EC) during a treadmill exercise sestamibi stress test with MACE was investigated in 490 nondiabetics and 404 diabetics. Mean follow-up was 53 months. Results: Nondiabetics with a predicted EC < 85% had a higher prevalence of myocardial ischemia (34% vs. 19%, p = 0.0002), 2- or 3-vessel obstructive coronary artery disease (CAD) (31% vs. 13%, p = 0.016), myocardial infarction (MI) (17% vs. 7%, p = 0.0005), stroke (8% vs. 2%, p = 0.002), death (11% vs. 3%, p = 0.0002), and MI or stroke or death at follow-up (32% vs. 11%, p < 0.001) compared to nondiabetics with a predicted EC ≥ 85%. Diabetics with a predicted EC < 85% had a higher prevalence of myocardial ischemia (48% vs. 32%, p = 0.0009), 2- or 3-vessel obstructive CAD (54% vs. 28%, p = 0.001), MI (32% vs. 14%, p < 0.001), stroke (22% vs. 6%, p < 0.001), death (17% vs. 9%, p = 0.031), and MI or stroke or death at follow-up (65% vs. 27%, p < 0.001). Stepwise Cox regression analysis showed decreased EC was an independent and significant risk factor for MACE among nondiabetics (hazard ratio 3.3...

‣ An??lise do desempenho de um aerogerador de pequeno porte

Acunha Junior, Ivoni Carlos
Fonte: Universidade Federal do Rio Grande Publicador: Universidade Federal do Rio Grande
Tipo: Dissertação de Mestrado
Português
Relevância na Pesquisa
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Disserta????o(mestrado) - Universidade Federal do Rio Grande, Programa de P??s-Gradua????o em Engenharia Oce??nica, Escola de Engenharia, 2006.; O objetivo deste trabalho ?? analisar o desempenho de um gerador e??lico de pequeno porte. Para isto foi instalado um aerogerador de velocidade vari??vel com pot??ncia nominal de 250 W. O aerogerador utiliza o sistema de estol ativo para controle de rota????o e prote????o, maximizando a efici??ncia aerodin??mica, minimizando a complexidadee os custos de fabrica????o do sistema os quais poderiam ser impeditivos ?? gera????o de energia com estes equipamentos em fun????o da sua pequena capacidade de gera????o. Para monitoramento do sistema foi instalada uma torre anemom??trica contendo dois anem??metros de tr??s conchas, um sensor de dire????o do tipo leme direcional e um sistema de aquisi????o e armazenamento de dados (data logger), um amper??metro tipo alicate utilizado para medi????o da corrente el??trica e um volt??metro para medi????o da tens??o, ambos com um sistema de armazenamento de dados e um medidor de energia. Com os dados de vento medidos no local e a pot??ncia convertida, calculada atrav??s da tens??o e corrente el??trica produzida pelo aerogerador foi constru??da acurva de pot??ncia deste e comparada com a curva de pot??ncia fornecida pelo fabricante...

‣ Innovative and Absorptive Capacity of International Knowledge : An Empirical Analysis of Productivity Sources in Latin American Countries

Castillo, Leopoldo Laborda; Salem, Daniel Sotelsek; Guasch, Jose Luis
Fonte: Banco Mundial Publicador: Banco Mundial
Português
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This paper examines two sources of global knowledge spillovers: foreign direct investments and trade. Empirical evidence demonstrates that foreign direct investment and trade can contribute to overall domestic productivity growth only when the technology gap between domestic and foreign firms is not too large and when a sufficient absorptive capacity is available in domestic firms. The paper proposes the terms research and development and labor quality to capture the innovative and absorptive capacity of the country. The spillover effects in productivity are analyzed using a stochastic frontier approach. This productivity (in terms of total factor productivity) is decomposed using a generalized Malmquist output oriented index, in order to evaluate the specific effect in technical change, technical efficiency change, and scale efficiency change. Using country-level data for 16 Latin American countries for 1996-2006, the empirical analysis shows positive productivity spillovers from foreign direct investment and trade only when the country has absorptive capacity in terms of research and development. Foreign direct investment and trade spillovers are found to be positive and significant for scale efficiency change and total productivity factor change.

‣ Monitoring Performance of Electric Utilities : Indicators and Benchmarking in Sub-Saharan Africa

Tallapragada V.S.N., Prasad; Shkaratan, Maria; Izaguirre, Ada Karina; Helleranta, Jaakko; Rahman, Saifur; Bergman, Sten
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Português
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36.716235%
Performance of electric utilities is essential for the reform of the electricity sector in the Sub-Saharan Africa (SSA) countries. The World Bank is leading a number of initiatives to improve electric utility performance in SSA. The Africa Energy unit of the World Bank recently introduced the Electric Utility Capacity Assistance Program (EUCAP) for Africa. Among other activities, the EUCAP aims to collate relevant utility performance data within the context of the Bank operations, with the dual objective of assessing the impact of reforms and motivating utility management to achieve better outcomes. In order to reach this objective, performance benchmarking approach was developed. In this approach, benchmarking starts with the selection of the Key Performance Indices (KPIs) reflecting major elements of utility day-to-day operations, including technical, operational and financial. Then a framework to compare performance of the sector in various countries and among utilities using these indices is applied.

‣ How Fit are Feed-in Tariff Policies? Evidence from the European Wind Market

Zhang, Fan
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Português
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36.80874%
Feed-in tariffs have become the most widely used policy instrument to promote renewable energy deployment around the world. This paper examines the relation between tariff setting and policy outcome based on wind capacity expansion in 35 European countries over the 1991-2010 period. Using a dynamic panel data model, it estimates the long-run elasticity of wind deployment with respect to the level of feed-in support. The analysis finds that higher subsidies do not necessarily yield greater levels of wind installation. Non-economic barriers and rent-seeking may have contributed to the weak correlation. On the other hand, the length of feed-in contract and guaranteed grid access are important determinants of policy effectiveness. A one-year extension of an original 5-year agreement on average increases wind investment by 6 percent annually, while providing an interconnection guarantee almost doubles wind investment in one year.

‣ Peru Opportunities and Challenges of Small Hydropower Development

Meier, Peter; Zolezzi, Eduardo H.; Bogach, Susan V.; Muir, Terence; Bazex, Karen
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Português
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Peru is favored by a stable and growing economy and the availability of indigenous sources of energy for electricity generation, including hydro and natural gas. The Peruvian electricity sector is among the few in Latin America and Caribbean (LAC) that has not confronted a crisis in recent years. The power sector in Peru was reformed and restructured between 1991 and 1993, followed by a privatization and concession process. A modern legal and regulatory framework was established in the electricity concessions law of 1992-93. This report contains the following chapters: (1) introduction; (2) resource potential and technical capacity for development of small hydropower in Peru; (3) economic and financial viability of small hydro development in Peru; (4) institutional and regulatory environment; (5) identification of barriers to small hydropower development and mitigation measures; (6) international experience with small hydropower development; and finally (7) conclusions and recommendations.

‣ How Much Could South Asia Benefit from Regional Electricity Cooperation and Trade?

Timilsina, Govinda R.; Toman, Michael; Karacsonyi, Jorge; de Tena Diego, Luca
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Trabalho em Andamento
Português
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The South Asia region is lagging behind many regions in the world in regional electricity cooperation and trading, despite the huge anticipated benefits. This study uses an electricity planning model that produces optimal expansion of electricity generation capacities and transmission interconnections in the long-term to quantify the benefits of unrestricted cross-border electricity trade in the South Asia during 2015–40. The study finds that the unrestricted electricity trade provision would save US$226 billion (US$9 billion per year) of electricity supply costs over the period. The ratio of the present value of benefits, in the form of reduction of fuel costs, to the present value of increased costs due to generation and interconnection would be 5.3. The provision would reduce regional power sector carbon dioxide emissions by 8 percent, mainly because of substitution of coal-based generation with hydro-based generation, although regional emissions would be well above current levels absent other policy interventions. To achieve these benefits...

‣ Measures of capacity realisation and productivity growth for Bangladesh food processing industries

Salim, Ruhul A; Kalirajan, Kaliappa
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Working/Technical Paper Formato: 134668 bytes; application/pdf
Português
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This paper evaluates the performance of firms in the Bangladesh food processing industries in terms of their productive capacity realisation and total factor growth. Using the random coefficient frontier production function is used for this purpose, the total factor productivity growth is decomposed into a change in productive capacity realisation and technical progress. Empirical results show that there is some technological progress in a number of the food processing industries, however, the overall poor performance of this sector is due to the low capacity realisation of many individual firms, even after the implementation of economic reforms. The results also show that output growth in recent years was mainly do to input growth.

‣ Effect of soil variability on the bearing capacity of footings on multi-layered soil.

Kuo, Yien Lik
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2009 Português
Relevância na Pesquisa
46.723594%
Footings are often founded on multi-layered soil profiles. Real soil profiles are often multi-layered with material constantly varying with depth, which affects the footing response significantly. Furthermore, the properties of the soil are known to vary with location. The spatial variability of soil can be described by random field theory and geostatistics. The research presented in this thesis focuses on quantifying the effect of soil variability on the bearing capacity of rough strip footings on single and two layered, purely-cohesive, spatially variable soil profiles. This has been achieved by using Monte Carlo analysis, where the rough strip footings are founded on simulated soil profiles are analysed using finite element limit analysis. The simulations of virtual soil profiles are carried out using Local Average Subdivision (LAS), a numerical model based on the random field theory. An extensive parametric study has been carried out and the results of the analyses are presented as normalized means and coefficients of variation of bearing capacity factor, and comparisons between different cases are presented. The results indicate that, in general, the mean of the bearing capacity reduces as soil variability increases and the worst case scenario occurs when the correlation length is in the range of 0.5 to 1.0 times the footing width. The problem of estimating the bearing capacity of shallow strip footings founded on multi-layered soil profiles is very complex...

‣ Strengthening Inclusive Ownership through Capacity Development; Operational Lessons from Case Studies

Balbo Di Vinadio, Tommaso; Sinha, Priyanka; Sachdeva, Paramjit
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Working Paper; Publications & Research :: Working Paper; Publications & Research
Português
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Ownership of development goals and priorities by local stakeholders is widely viewed as a critical factor impacting development effectiveness and achievement of the Millennium Development Goals (MDGs). The 2008 Accra Agenda for Action identifies the concept as one of inclusive ownership, involving parliaments, local authorities and civil society organizations (CSOs), as well as governments. The importance and challenges of building such broad-based ownership across society were a key discussion topic at the Fourth High Level Forum on Aid Effectiveness in November 2011 at Busan. This study aims to generate deeper operational knowledge on what can be done to foster inclusive ownership; its initial findings were presented at Busan. This study involves a retrospective review of a small sample of cases. From these cases it is possible to demonstrate that inclusive ownership, when considered in terms of the operational dimensions examined in the study, can improve as a result of strategic capacity development efforts. It also shows how using an analytic lens such as the CDRF...

‣ Moving Up the Value Chain : A Study of Malaysia's Solar and Medical Device Industries

World Bank
Fonte: Washington, DC Publicador: Washington, DC
Tipo: Economic & Sector Work :: Other Urban Study; Economic & Sector Work
Português
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This report responds to a request by the Government of Malaysia to examine how Malaysia can move up the value chain in the solar and medical device industries. Through the lens of long-term development, the overall growth performance of the Malaysian economy has been a resounding success story. The Commission on growth and development listed Malaysia as one of only 13 countries that registered sustained growth of 7 percent or more for a period of 25 years or longer. Much of this growth occurred on the back of a buoyant manufacturing sector, which was spurred by Malaysia's export-led industrialization model reliant on foreign direct investment (FDI). Multinational firms favored the country for its geographical location, political stability, reliable infrastructure, elastic supply of low-cost labor and attractive incentives. As a result of this success, Malaysia became the region's third-most open economy to trade, with the electrical and electronics (E&E) industry accounting at its peak for approximately half of all trade. Moving up the value chain concerns the process of shifting the productive activity of a nation...

‣ Capacity Factors of a Point-to-point Network

Li, Yuan; Zhao, Yue; Kan, Haibin
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
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In this paper, we investigate some properties on capacity factors, which were proposed to investigate the link failure problem from network coding. A capacity factor (CF) of a network is an edge set, deleting which will cause the maximum flow to decrease while deleting any proper subset will not. Generally, a $k$-CF is a minimal (not minimum) edge set which will cause the network maximum flow decrease by $k$. Under point to point acyclic scenario, we characterize all the edges which are contained in some CF, and propose an efficient algorithm to classify. And we show that all edges on some $s$-$t$ path in an acyclic point-to-point acyclic network are contained in some 2-CF. We also study some other properties of CF of point to point network, and a simple relationship with CF in multicast network. On the other hand, some computational hardness results relating to capacity factors are obtained. We prove that deciding whether there is a capacity factor of a cyclic network with size not less a given number is NP-complete, and the time complexity of calculating the capacity rank is lowered bounded by solving the maximal flow. Besides that, we propose the analogous definition of CF on vertices and show it captures edge capacity factors as a special case.

‣ Assessment of the behaviour factor for the seismic design of reinforced concrete structural walls according to SANS 10160 - Part 4

Le Roux,R C; Wium,J A
Fonte: Journal of the South African Institution of Civil Engineering Publicador: Journal of the South African Institution of Civil Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2012 Português
Relevância na Pesquisa
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Reinforced concrete structures, designed according to proper capacity design guidelines, can deform inelastically without loss of strength. Therefore, such structures need not be designed for full elastic seismic demand, but could be designed for a reduced demand. In codified design procedures this reduced demand is obtained by dividing the full elastic seismic demand by a code-defined behaviour factor. There is, however, no consensus in the international community regarding the appropriate value to be assigned to the behaviour factor. The purpose of this study is to assess the value of the behaviour factor currently prescribed by SANS 10160-4 (2011) for the design of reinforced concrete structural walls. This is done by comparing displacement demand to displacement capacity for a series of structural walls. The first step in seismic force-based design is the estimation of the fundamental period of the structure. The influence of this first crucial step is investigated in this study by considering two period calculation methods. It was found that, regardless of the period calculation method, the current behaviour factor value prescribed in SANS 10160-4 (2011) is adequate to ensure that inter-storey drift of structural walls would not exceed code-defined drift limits.