497 resultados para MAXIMIZATION
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In this study, thermal, exergetic analysis and performance evaluation of seawater and fresh wet cooling tower and the effect of parameters on its performance is investigated. With using of energy and mass balance equations, experimental results, a mathematical model and EES code developed. Due to lack of fresh water, seawater cooling is interesting choice for future of cooling, so the effect of seawater in the range of 1gr/kg to 60gr/kg for salinity on the performance characteristics like air efficiency, water efficiency, output water temperature of cooling tower, flow of the exergy, and the exergy efficiency with comparison with fresh water examined. Decreasing of air efficiency about 3%, increasing of water efficiency about 1.5% are some of these effects. Moreover with formation of fouling the performance of cooling tower decreased about 15% which this phenomena and its effects like increase in output water temperature and tower excess volume has been showed and also accommodate with others work. Also optimization for minimizing cost, maximizing air efficiency, and minimizing exergy destruction has been done, results showed that optimization on minimizing the exergy destruction has been satisfy both minimization of the cost and the maximization of the air efficiency, although it will not necessarily permanent for all inputs and optimizations. Validation of this work is done by comparing computational results and experimental data which showed that the model have a good accuracy.
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This work describes preliminary results of a two-modality imaging system aimed at the early detection of breast cancer. The first technique is based on compounding conventional echographic images taken at regular angular intervals around the imaged breast. The other modality obtains tomographic images of propagation velocity using the same circular geometry. For this study, a low-cost prototype has been built. It is based on a pair of opposed 128-element, 3.2 MHz array transducers that are mechanically moved around tissue mimicking phantoms. Compounded images around 360 degrees provide improved resolution, clutter reduction, artifact suppression and reinforce the visualization of internal structures. However, refraction at the skin interface must be corrected for an accurate image compounding process. This is achieved by estimation of the interface geometry followed by computing the internal ray paths. On the other hand, sound velocity tomographic images from time of flight projections have been also obtained. Two reconstruction methods, Filtered Back Projection (FBP) and 2D Ordered Subset Expectation Maximization (2D OSEM), were used as a first attempt towards tomographic reconstruction. These methods yield useable images in short computational times that can be considered as initial estimates in subsequent more complex methods of ultrasound image reconstruction. These images may be effective to differentiate malignant and benign masses and are very promising for breast cancer screening. (C) 2015 The Authors. Published by Elsevier B.V.
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From the end of the 80s, the Brazilian higher education experience strong growth, coming from the private sector, which would intensify further in the late 90th Higher education has become a lucrative business. With a drop in the number of students entering and strong competition, the number of idle places in private institutions of higher education reached 49.5% in 2004. That same year, by Measure, was the University for All Program (PROUNI) program, to include high school students from public higher education, offering scholarships to those students in private HEIs. In exchange, the IES gain tax exemption. The objective of this research is to investigate the game of interest occurred in the formulation of this program and identify the model and the political game and has led to the creation of PROUNI, analyzing the process occurred since the wording of a bill, the issue of Measure Law and that the legitimacy PROUNI, with the most important changes made initial model. Since the first draft of the Law to the final Act, the PROUNI was disfigured in its main points, as the percentage of stock for paying students, the process of selection of stock and bond of the IES program. Throughout the process of creating the program, it is quite clear the performance of the institutions representing the private higher education. As reference for the analysis was based on Rational Choice Theory of Political Science. The basic argument of the methods based on rational choice is the maximization of the benefit will be the main motivation of individuals, but they can give that your goals can be achieved more effectively through institutional action and thereby discover that their conduct is shaped by institutions. Thus, individuals rationally choose to get to a certain extent constrained to join in certain institutions, whether voluntarily or not. The PROUNI was submitted by government and public policy covered by the mystical aura of the discourse of social justice and economic development, as in higher education includes a stratum of people who would not have access to the university, due to restrictions in the supply network public higher education. However, the greatest benefit from the program are the private HEIs, which through a difficult time in a scenario marked by high competition and idleness of nearly half of the vacancies offered. The PROUNI became a program that prioritizes access and not the residence of the student to higher education. More serious than a supporting program for students Fellows is a program supporting the institutions of private education
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O principal objetivo deste estudo foi compreender as etapas do percurso artístico do compositor portuense Ciríaco de Cardoso (1846 – 1900) e os discursos em torno de uma das suas obras mais célebres: O burro do Sr. Alcaide (1891). No primeiro capítulo procurou-se identificar e discutir os critérios que estiveram na base das opções profissionais tomadas por Ciríaco. O decurso da sua carreira leva a crer que possuía uma noção profunda das atividades que, no espaço lusófono, apresentavam maior potencial de aquisição quer de capital económico, quer de capital simbólico. É por isso que, mobilizando recursos das suas redes de sociabilidade, circula por instituições no Porto e em Lisboa mas, também, pelo lucrativo mercado teatral do Rio de Janeiro, assim como em Paris. Concentra-se no popular teatro musical – principal fonte de sustento – em paralelo com a atividade concertística e operática – forma de distinção atendendo à competitividade no mercado musico-teatral. Percebe também que a maximização do seu poder simbólico depende da legitimação alcançada pela sua associação às elites socioculturais locais, pelo que fomenta o estabelecimento de sociabilidades que se estendem inclusive às casas reais portuguesa e brasileira. Paradoxalmente, as edes mais próximas de Ciríaco estavam vinculadas a um idealismo republicano, relacionamento que exponencial proliferação de discursos dessa índole pelos media lusófonos (sobretudo a partir do tricentenário camoniano de 1880) e, por outro, pela aparente inexistência de registos que associem inequivocamente o artista ao ativismo republicano. Não obstante, é provável que Ciríaco de Cardoso tenha explorado o filão antimonárquico na programação da temporada de 1891 do Teatro da Avenida. O segundo capítulo explora a produção de O burro do Sr. Alcaide, através da análise da sua estrutura e das relações da obra com a realidade portuguesa da última década do século XIX. Embora respeite o modelo da opereta francesa, apresenta também características que poderão levar a que seja interpretada como transmissora de uma portugalidade idealizada, em linha com o nacionalismo português do último quartel do século. A ação decorre em Lisboa, cenário de interação entre personagens-tipo e caricaturas de personalidades concretas da elite sociopolítica portuguesa. Através de referências ao sebastianismo, satiriza-se o comportamento dessas elites, assim como as instituições da monarquia constitucional e a prevalência de uma visão messiânica dos governantes por parte da sociedade em geral. Faz-se a apologia da ruralidade através de tópicos musicais e de quadros onde se constrói uma imagem da música tradicional, correspondendo a uma idealização da nação – notada e enfatizada na receção pela crítica. Utiliza também outros tópicos pertencentes à paisagem sonora do público burguês, completando a expressão da urbanidade de um país onde essas duas realidades não eram ainda completamente dissociáveis. Contudo, ao não propor alterações efetivas à hierarquia da sociedade portuguesa finissecular, o desfecho da obra leva a concluir que esta terá consistido numa forma de propaganda o que, por um lado, explica o seu mediatismo e, por outro, vincula os seus autores – mais ou menos conscientes disso – às lutas políticas em curso aquando do ano da sua estreia.
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We provide a comprehensive study of out-of-sample forecasts for the EUR/USD exchange rate based on multivariate macroeconomic models and forecast combinations. We use profit maximization measures based on directional accuracy and trading strategies in addition to standard loss minimization measures. When comparing predictive accuracy and profit measures, data snooping bias free tests are used. The results indicate that forecast combinations, in particular those based on principal components of forecasts, help to improve over benchmark trading strategies, although the excess return per unit of deviation is limited.
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International audience
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Dissertação de mest. em Aquacultura, Unidade de Ciências e Tecnologia dos Recursos Aquáticos, Univ. do Algarve, 1997
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Os sistemas de informação têm cada vez mais importância nos serviços de saúde. Sistemas de informação eficientes, permitem a maximização da gestão dos serviços promovendo a melhoria da qualidade dos cuidados. A ordem dos enfermeiros sugere a implementação de sistemas de registos que englobem necessidades de cuidados, intervenções de enfermagem e resultados dessas mesmas intervenções. A associação portuguesa de enfermeiros faz referência à importância de uma linguagem comum entre os enfermeiros. A linguagem CIPE® “é uma classificação de fenómenos, intervenções e resultados a nível da enfermagem. Pretende ser uma matriz unificadora em que as taxonomias e classificações de enfermagem já existentes se possam entrecruzar, de modo a permitir comparar dados em enfermagem” (CIE,2000:11) A adaptação da linguagem CIPE à gravidez, trabalho de parto e parto, é uma mais-valia no que concerne á realização de registos de qualidade que permitam uma linguagem comum, abrangente e facilitadora da comunicação entre os enfermeiros, e entre estes e outros profissionais de saúde. Através da consulta de bibliografia, dos manuais CIPE® disponíveis, de documentos existentes no serviço, dos processos clínicos e pelos conhecimentos adquiridos durante a especialização de enfermagem de saúde materna e obstetrícia, foi feito o levantamento dos fenómenos, diagnósticos e intervenções de enfermagem em relação aos focos gravidez, trabalho de parto e parto, para futura introdução no sistema informático, tendo em conta as actividades mais frequentes na maternidade para estes focos. A definição de uma Linguagem uniforme a ser utilizada por todos os enfermeiros do serviço, levou a um esforço conjunto da equipa de enfermagem e chefia. Este trabalho continua em curso, uma vez que as actividades que se realizam na maternidade têm que ser todas parametrizadas, o que torna o trabalho de parametrização um pouco mais moroso. Os dados só serão introduzidos no sistema depois da parametrização de todas actividades do serviço. Após a introdução dos dados no sistema informático e da linguagem CIPE perfeitamente adaptada à realidade da maternidade, é nossa convicção que a economia de tempo e a desburocratização dos registos libertará os profissionais para uma relação enfermeiro/utente que se pretende mais humana.
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The literature on preferences for redistribution has paid little attention to the effect of social mobility on the demand for redistribution, which is in contrast with the literature on class-voting, where studies on the effect of social mobility has been very common. Some works have addressed this issue but no systematic test of the hypotheses connecting social mobility and preferences has been done. In this paper we use the diagonal reference models to estimate the effect of origin and destination class on preferences for redistribution in a sample of European countries using data from the European Social Survey. Our findings indicate that social origin matters to a little extent to explain preferences, as newcomers tend to adopt the preferences of the destination class. Moreover, we have found only limited evidence supporting the acculturation hypothesis and not support for the status maximization hypothesis. Furthermore, the effect of social origin varies largely between countries. In a second step of the analysis we investigate what are the national factors explaining this variation. The empirical evidence we present leads to conclude that high rates of upward social mobility sharply reduce the effect of social origin on preferences for redistribution
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Due to lack of information on the use of non-protein energy sources in diets for pacu (Piaractus mesopotamicus), a 2 x 2 x 3 factorial experiment was conducted to evaluate the performance and digestibility of 12 diets containing approximately two crude protein (CP; 220 and 250 g kg(-1)), two lipid (40 and 80 g kg(-1)) and three carbohydrate levels (410, 460 and 500 g kg(-1)). The pacu juveniles-fed diets containing 220 g kg(-1) CP did not respond (P > 0.05) to increased dietary lipid and carbohydrate levels, but the fish-fed diets containing 250 g kg(-1) CP showed a better feed conversion ratio. There were interactions in weight gain (WG), specific growth rate (SGR), crude protein intake (CPI) and feed conversion rate (FCR) dependent on dietary carbohydrate and lipid levels, showing positive effects of increasing carbohydrate levels only for fish-fed diets containing 80 g kg(-1) lipid level. However, when the diets contained 40 g kg(-1) lipid, the best energy productive value (EPV) results were obtained at 460 g kg(-1) carbohydrate. A higher usage of lipids (80 g kg(-1)) reduced CPI and was detrimental to protein [apparent digestibility coefficient (ADC)(CP)] and energy (ADC(GE)), but did not affect growth. The ADC(GE) improved proportionally as dietary carbohydrate levels increased (P < 0.05), increasing the concentration of digestible energy. In addition, the WG, CPI, ADC(GE) results showed best use of the energy from carbohydrates when dietary protein level was 250 g kg(-1) CP. The utilization of 250 g kg(-1) CP in feeds for juvenile pacu for optimal growth is suggested. Therefore, the optimum dietary lipid and carbohydrate levels depend on their combinations. It can be stated that pacu uses carbohydrates as effectively as lipids in the maximization of protein usage, as long as it is not lower than 250 g kg(-1) CP or approximately 230 g kg(-1) digestible protein.
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In this study, interactions between potential hierarchical value chains existing in the production structure and industry-wise productivity growths are sought. We applied generalized Chenery-Watanabe heuristics for matrix linearity maximization to triangulate the input-output incidence matrix for both Japan and the Republic of Korea, finding the potential directed flow of values spanning the industrial sectors of the basic (disaggregated) industry classifications for both countries. Sector specific productivity growths were measured by way of the Trönquvist index, using the 2000-2005 linked input-output tables for both Japan and Korea.
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Background: Adolescents with chronic disease (CD) can be more vulnerable to adverse psychosocial outcomes. This study aims: 1) to identify differences in psychosocial variables (health-related quality of life, psychosomatic complaints, resilience, self-regulation and social support) among adolescents who feel that CD affects or does not affect school/peers connectedness (measured by self-reported participation in school and social activities); and 2) to assess the extent to which psychosocial variables are associated with connectedness in school and peer domains. Methods: A cross-sectional study was conducted in 135 adolescents with CD (51.9% boys), average age of 14 ± 1. 5 years old (SD = 1.5). Socio-demographic, clinical, and psychosocial variables were assessed, using a self-reported questionnaire, which included the Chronic Conditions Short Questionnaire, KIDSCREEN-10 Index, Symptoms Check-List, Healthy Kids Resilience Assessment Module Scale, Adolescent Self-Regulatory Inventory, and Satisfaction with Social Support Scale. Descriptive statistics, GLM-Univariate ANCOVA and Logistic Regression were performed using the IBM Statistical Package for Social Sciences (SPSS), version 22.0. The significance level was set at p < 0.05. Results: Thirteen to eighteen percent of the adolescents felt that CD affected participation at school (PSCH) and participation in leisure time with friends (PLTF). These adolescents presented lower results for all psychosocial study variables, when compared with adolescents who did not feel affected in both areas of participation. From the studied psychosocial variables, the most important ones associated with PSCH (after controlling for age, gender, diagnosis, and education level of father/mother) were self-regulation and psychosomatic health. Concerning the PLTF, social support was the sole variable explaining such association. Conclusions: The present study pointed out the association between psychosocial variables; and living with a CD and school/peers connectedness. The need to focus on the assessment of the effects of a CD on adolescents’ lives and contexts is suggested, as well as on the identification of vulnerable adolescents. Such identification could help to facilitate the maximization of social participation of adolescents with CD, and to plan interventions centered on providing support and opportunities for a healthy youth development. For that purpose, a complex and multifactorial approach that includes clinicians, schools, family, and peers may be proposed.
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Pitch Estimation, also known as Fundamental Frequency (F0) estimation, has been a popular research topic for many years, and is still investigated nowadays. The goal of Pitch Estimation is to find the pitch or fundamental frequency of a digital recording of a speech or musical notes. It plays an important role, because it is the key to identify which notes are being played and at what time. Pitch Estimation of real instruments is a very hard task to address. Each instrument has its own physical characteristics, which reflects in different spectral characteristics. Furthermore, the recording conditions can vary from studio to studio and background noises must be considered. This dissertation presents a novel approach to the problem of Pitch Estimation, using Cartesian Genetic Programming (CGP).We take advantage of evolutionary algorithms, in particular CGP, to explore and evolve complex mathematical functions that act as classifiers. These classifiers are used to identify piano notes pitches in an audio signal. To help us with the codification of the problem, we built a highly flexible CGP Toolbox, generic enough to encode different kind of programs. The encoded evolutionary algorithm is the one known as 1 + , and we can choose the value for . The toolbox is very simple to use. Settings such as the mutation probability, number of runs and generations are configurable. The cartesian representation of CGP can take multiple forms and it is able to encode function parameters. It is prepared to handle with different type of fitness functions: minimization of f(x) and maximization of f(x) and has a useful system of callbacks. We trained 61 classifiers corresponding to 61 piano notes. A training set of audio signals was used for each of the classifiers: half were signals with the same pitch as the classifier (true positive signals) and the other half were signals with different pitches (true negative signals). F-measure was used for the fitness function. Signals with the same pitch of the classifier that were correctly identified by the classifier, count as a true positives. Signals with the same pitch of the classifier that were not correctly identified by the classifier, count as a false negatives. Signals with different pitch of the classifier that were not identified by the classifier, count as a true negatives. Signals with different pitch of the classifier that were identified by the classifier, count as a false positives. Our first approach was to evolve classifiers for identifying artifical signals, created by mathematical functions: sine, sawtooth and square waves. Our function set is basically composed by filtering operations on vectors and by arithmetic operations with constants and vectors. All the classifiers correctly identified true positive signals and did not identify true negative signals. We then moved to real audio recordings. For testing the classifiers, we picked different audio signals from the ones used during the training phase. For a first approach, the obtained results were very promising, but could be improved. We have made slight changes to our approach and the number of false positives reduced 33%, compared to the first approach. We then applied the evolved classifiers to polyphonic audio signals, and the results indicate that our approach is a good starting point for addressing the problem of Pitch Estimation.
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This paper presents a stochastic mixed-integer linear programming approach for solving the self-scheduling problem of a price-taker thermal and wind power producer taking part in a pool-based electricity market. Uncertainty on electricity price and wind power is considered through a set of scenarios. Thermal units are modelled by variable costs, start-up costs and technical operating constraints, such as: forbidden operating zones, ramp up/down limits and minimum up/down time limits. An efficient mixed-integer linear program is presented to develop the offering strategies of the coordinated production of thermal and wind energy generation, having as a goal the maximization of profit. A case study with data from the Iberian Electricity Market is presented and results are discussed to show the effectiveness of the proposed approach.
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In a recent paper [1] Reis showed that both the principles of extremum of entropy production rate, which are often used in the study of complex systems, are corollaries of the Constructal Law. In fact, both follow from the maximization of overall system conductivities, under appropriate constraints. In this way, the maximum rate of entropy production (MEP) occurs when all the forces in the system are kept constant. On the other hand, the minimum rate of entropy production (mEP) occurs when all the currents that cross the system are kept constant. In this paper it is shown how the so-called principle of "minimum energy expenditure" which is often used as the basis for explaining many morphologic features in biologic systems, and also in inanimate systems, is also a corollary of Bejan's Constructal Law [2]. Following the general proof some cases namely, the scaling laws of human vascular systems and river basins are discussed as illustrations from the side of life, and inanimate systems, respectively.