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Search Results: 1 - 10 of 333120 matches for " Silvia S; "
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Predispatch of Hydroelectric Power Systems with Modifications in Network Topologies  [PDF]
Silvia M. S. Carvalho, Aurelio Oliveira
Applied Mathematics (AM) , 2014, DOI: 10.4236/am.2014.515221

In this article, the primal-dual interior-point methods are used to minimize costs and losses in a predispatch model for the generation and transmission of direct current (DC) power flow in a hydroelectric system with pre-programmed manipulations; i.e., in cases of preventive maintenance, within a period of twenty-four hours. From the computational standpoint, the effort required to solve a problem with and without manipulations is similar, and the reasons why will be also discussed in this study. Computational results prove these findings.

Collaborative Intelligence in Smart Cities: A Systematic Review  [PDF]
Viviani Kwecko, Silvia S. da C. Botelho
Social Networking (SN) , 2018, DOI: 10.4236/sn.2018.73015
The objective of this research is to present a systematic analysis, in which we seek to identify the concepts of intelligent city, with the intention of recognizing the nature of this intelligence before the participation of the population. Therefore, the research associates concepts as smart cities, citizen participation and social web, identifying publications between 2012 and the first quarter of 2018 and questioning what the intelligent city is and how this concept is able to (re)organize the learning processes of the territory from the informal dynamics of the contemporary city. The qualitative analysis of the documents revealed an innumerable of definitions and related terms: smart, intelligent, ubiquitous, digital, knowledge, sustainable, crowd sourcing, innovative; structured in three types of approaches: technological focus, focus on human resources and focus on citizen-related governance from the following domains: media convergence, public and regulatory information policies, infrastructure management, real-time data mining and extraction, geographic information system, crowd computing, smart cities education, and social monitoring and control. In spite of the access to a great amount of data, we verify that the concept of intelligent city is referenced by a significant number of researches, but, in smaller number, works that present models of construction of a collective intelligence for the city. From this perspective, we identified the need to recognize technological education interventions for communication between individuals and the city. Because we believe that only through the implementation and management of techno-educommunication ecosystems will be able to promote a culture of participation.
Tres nuevas especies de Ruellia L. (Acanthaceae) de Venezuela
Acta Botánica Venezuelica , 2001,
Abstract: three new species of ruellia (acanthaceae) from the venezuelan coastal range, are described: ruellia carmenaemiliae, from wet forests of the states of carabobo and yaracuy, r. saeri, from xerophytic scrublands of the state of lara and r. salmeronensis, from ombrophilous forests of the states of miranda and vargas.
Tres nuevas especies de Ruellia L. (Acanthaceae) de Venezuela
Acta Botánica Venezuelica , 2001,
Abstract: Se describen tres nuevas especies de Ruellia (Acanthaceae), procedentes de la Cordillera de la Costa: Ruellia carmenaemiliae, de las selvas húmedas de los estados Carabobo y Yaracuy; R. saeri, del bosque xerofítico del estado Lara; R. salmeronensis, de bosques ombrófilos de los estados Miranda y Vargas. Three new species of Ruellia (Acanthaceae) from the Venezuelan Coastal Range, are described: Ruellia carmenaemiliae, from wet forests of the States of Carabobo and Yaracuy, R. saeri, from xerophytic scrublands of the State of Lara and R. salmeronensis, from ombrophilous forests of the States of Miranda and Vargas.
O risco e as estratégias de avalia o dos fundos de investimento de renda variável / El riesgo y las estrategias en la evaluación de los fondos de inversión de renta variable
Silvia Bou Ysás
Revista Organiza??es em Contexto , 2006,
Abstract: O objetivo deste trabalho em consiste prop r uma medida de desempenho adaptada para os fundos de investimento de renda variável. As características específicas desse tipo de portfólios induzem a fazer por meio de uma aproxima o baseada no L.M.C., raz o por que o risco total do portfólio é escolhido como medida de risco . Introduz o passivo e as estratégias ativas na análise, o que pode desenvolver uma medida de desempenho, que, além de medir o rendimento pela gerência efetiva, ainda busca-se medir o grau de suposta atividade pelo portfólio a avaliar.
A crítica literária como representa o: estudo de uma modalidade ensaística de Azorín
Silvia Inês Cárcamo
Caligrama : Revista de Estudos Romanicos , 1997,
Abstract: Resumo: Examinamos um tipo particular de ensaio de crítica literária produzido nas primeiras décadas de nosso século em que o autor, José Martínez Ruiz (Azorín), recria obras clássicas da literatura espanhola. Estudamos a intera o do discurso citado com o discurso narrativo que evidencia o problema da transmiss o do discurso do outro. Relacionamos, ainda, a referida quest o com a contradi o apresentada na época entre o subjetivismo e os requerimentos coletivos. Situamos a crítica literária de Azorín em duas perspectivas: em primeiro lugar, o contexto cultural e sócio-político de princípios do século; em segundo lugar, as releituras que a posteridade realizou da sua ora, em cois momentos importantes de reformula o da tradi o na Espanha. Palavras-chave: José Martínez Ruiz; Azorín; literatura espanhola; crítica literaria; discurso citado; discurso narrativo. Resumen: Examinamos un tipo particular de ensayo de crítica literaria practicado en las primeras décadas de nuestro siglo, en el que el autor, José Martínez Ruiz (Azorín), recra obras clásicas de la literatura espa ola. Estudiamos la interación del discurso citado y del discurso narrativo que pone en evidencia el problema de la transmisión del discurso del Otro. Relacionamos dicha cuestión a la contracción existente en la época entre el subjetivismo y los requerimientos colectivos. Enfocamos la crítica literaria de Azorín teniendo en cuenta dos perspectivas: en primer lugar, la que atiende al contexto cultural y sociopolítico de principios de siglo, y considerando, en segundo lugar, las relecturas que la posteridad realizó de su obra, en dos momentos importantes de reformulación de la tradición en Espa a. Palabras-clave: José Martínez Ruiz; Azorín; literatura espa ola; crítica literaria; discurso citado; discurso narrativo. Keywords: José Martínez Ruiz; Azorín; Spanish literature; literary criticism; cited discourse; narrative discourse.
Validation of a SPME-GC Method for Azoxystrobin and Pyraclostrobin in Blueberries, and Their Degradation Kinetics  [PDF]
Martín S. Munitz, Silvia L. Resnik, María I. T. Montti, Silvia Visciglio
Agricultural Sciences (AS) , 2014, DOI: 10.4236/as.2014.511104
Abstract: Analytical method for the residues of strobilurins azoxystrobin and pyraclostrobin in blueberries was developed. Fungicide residues were determined by solid-phase microextraction (SPME) cou-pled to gas chromatography with micro-electron capture detector. The effect of pH values and fiber coatings were studied. The SPME fiber coating selected was 100 μm PDMS. The method is selective with adequate precision and high accuracy and sensitivity. Recoveries ranged within the 100% - 106% range for azoxystrobin, and 96% - 106% range for pyraclostrobin; and detection and quantification limits were 2.0 and 6.0 μg/kg for azoxystrobin, and 26.0 and 86.0 μg/kg for py-raclostrobin, respectively. Statistical parameters indicated the occurrence of matrix effect; con-sequently calibration was performed on spiked samples. Degradation of azoxystrobin and pyra-clostrobin was studied in blueberry fields located in Concordia, Argentina, with fruits from Emerald and Jewel varieties. The degradation of these fungicides in both blueberry varieties studied followed a first order rate kinetics, and the half-life for azoxystrobin was 11.6 and 17.8 days for Emerald and Jewel cultivars; and for pyraclostrobin was 5.5 and 8.0 days, respectively.
Interior-Point Methods Applied to the Predispatch Problem of a Hydroelectric System with Scheduled Line Manipulations  [PDF]
Silvia M. S. Carvalho, Aurelio R. L. Oliveira
American Journal of Operations Research (AJOR) , 2012, DOI: 10.4236/ajor.2012.22032
Abstract: Transmission line manipulations in a power system are necessary for the execution of preventative or corrective main- tenance in a network, thus ensuring the stability of the system. In this study, primal-dual interior-point methods are used to minimize costs and losses in the generation and transmission of the predispatch active power flow in a hydroelectric system with previously scheduled line manipulations for preventative maintenance, over a period of twenty-four hours. The matrix structure of this problem and the modification that it imposes on the system is also broached in this study. From the computational standpoint, the effort required to solve a problem with or without line manipulations is similar, and the reasons for this are also discussed in this study. Computational results sustain our findings.
Application of Simplex Method in the Radiotherapy Treatment  [PDF]
Thais R. Salvador, Silvia M. S. Carvalho, Mayk V. Coelho
Applied Mathematics (AM) , 2016, DOI: 10.4236/am.2016.717177
Abstract: This work presents an application of the Simplex Method for solving an optimal planning problem for cancer treatment by radiotherapy. Linear Programming can aid the optimal planning for radiation therapy, where the concern is to apply a high enough radiation in the tumor while saving significantly healthy regions or critical organs.
Sistema de asentamiento prehispánico en la Sierra Meridional de Cha?i (Salta, Argentina)
Vitry,Christian; Soria,Silvia S;
Andes , 2007,
Abstract: the area of research is located in the southern area of the cha?i mountain, salta province, argentina. the spatial and distributional structure of the archaeological sites and nearby mountain ranges has a great potential for research. these attributes, both qualitative and quantitative, allow the study of the variability and complexity of the settlement system in the region. our perspective is based in the evolution of the cultural landscape and the process of geopolitical change. the archaeological record reveals a recurrence in the settlement system, and we proposed a hypothetical model for the occupation of space in the regional development and inka periods. in this paper, different forms of power and possible emergent situations of social inequality are analyzed during these periods.
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