878 resultados para Receiver operating characteristic
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Este trabalho tem como objetivo fornecer uma análise detalhada do cenário da sustentabilidade ambiental e iniciativas de responsabilidade social corporativa nas empresas que operam no mercado de bens de consumo brasileiro. Para alcançar este objetivo as dez maiores empresas do mercado-alvo presente no Brasil foram analisadas por meio da classificação das suas iniciativas em três perspectivas amplas. Com esta classificação o cenário do mercado pode ser visto. As perspectivas utilizadas para a elaboração do trabalho são: (1) iniciativa ambiental ou social; (2) o foco interno ou externo e (3) a marca ou o custo como motivador. Depois de classificar todas as iniciativas, foi possível ver que as empresas similares, que operam em mercados semelhantes, têm estratégias que são muito parecidos entre si. Além disso, ficou claro que a estratégia de negócios da empresa influencia as suas políticas ambientais e sociais, em particular os objetivos que estas políticas procuram obter.Embora este trabalho apresente um panorama abrangente do setor de bens de consumo em relação a políticas de comportamento responsável das empresas, ele tem algumas limitações. A limitação mais significativa diz respeito a metodologia. As iniciativas foram avaliadas pela quantidade e a abrangência dos benefícios do impacto positivo não foram avaliados, impossibilitando assim a comparação do tamanho do impacto de cada empresa. Uma vez que pode haver um projeto de uma empresa que tem maior impacto do que vários outros feitos por alguma outra empresa. A metodologia foi baseada em clusters de categorias, no entanto, as iniciativas não são completamente uma coisa ou outra, ou seja, uma iniciativa pode ter diferentes impactos, drivers ou foco, nesses casos, os aspectos mais relevantes foram a escolhidos para classificá-los.
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Although the existence of spinoff equity gains is well documented, their source remains controversial. Arnong many potential causes, the literature suggests that spinoff equity gains could arise from expected tax benefits, expected takeover premia, operating performance improvement or from refocusing benefits. This paper investigates the link between spinoff announcement and post completion equity gains and post spinoff operating performance changes, takeover activity and refocusing benefits. The results indicate that spinoff announcement retums reflect anticipated takeover premiums as well as expected operating performance gains and refocusing benefits unrelated to operating performance. However, only the parent's operating performance gains are anticipated at the spinoff announcement. We find that post spinoff equity gains are driven mostly by operating performance changes for both parents and spun off subsidiaries. Takeover activity and unrelatedness of business lines between parent and subsidiary expIain littIe of post spinoff equity gains. OveralI, the data suggests that spinoffs equity gains mostly reflect anticipated real economic gains in terms of improved operating performance, and to a lesser extent takeover premium and refocusing benefit.
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FERNANDES, Fabiano A. N. et al. Optimization of Osmotic Dehydration of Papaya of followed by air-drying. Food Research Internation, v. 39, p. 492-498, 2006.
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This study attempts to investigate the school administration in the Department of Education of Rio Grande de Norte, in the period 1924 to 1928, in the context of conservative modernization in its management, implemented by Nestor Lima dos Santos. Addresses the trends of administrative Nestor Santos Lima and sequence of these variables so that we can correlate and monitor the development of various economic, social, cultural and political, to show how influenced and even determined the direction of education, not only the state of RN, but throughout the country. For this purpose, it is the recapitulation of the history of life, experiences of work and travel reports of this important figure, including administrative concepts, aiming to identify the school administration, introduced by him in the 1920s, as those who received influence of characters that included the social and historical context of the time, reconstituting the ways following the education. It was developed by Nestor shares in Lima on the administration of public schools, their way of management, and can see how was the process of modernization of education in Rio Grande do Norte state and how it followed the rapid changes, experienced by Brazil, during this period. Show up on the design aspects of modernizing Nestor Lima in the Department of Education, the Director General of Administrative Acts, the internal record of school groups, Isolated Schools, Schools rudimentary and the newly created Board of Education, highlighting the Internal Rules of Council but the General Regulations of the Department of Education. This work also highlights the proposed administrative Nestor of Lima, while educational model of an operating system of the organization, training and education, which is present in the area of production of discourse, through body practice, characteristic of the record established levels of policy development and implementation of educational instruction in all state. Key-words: school administration. Conservative modernization. Public Education
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The aim of this work is to characterize and use the characteristic parameters of the planar structures constructed with fin lines looking for their applications in devices, using PBG Photonic Band Gap photonic materials as substrate, operating in the millimeter and optic wave bands.The PBG theory will be applied for the relative permittivity attainment for the PBG photonic substrate s and p polarizations. The parameters considered in the structures characterization are the complex propagation constant and the characteristic impedance of unilateral and bilateral fin lines that were obtained by the use of the TTL Transverse Transmission Line Method, together with the Method of the Moments. The final part of this work comprises studies related to the behavior of the asymmetric unilateral fin line coupler with photonic substrate. This research opens perspectives for new works in this modern area. Numerical results are shown by means of bi-dimensional and three-dimensional graphics. Conclusions and suggestions for future works are also presented
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Three ranges of increasing temperatures (35-43, 37-45, 39-47degreesC) were sequentially applied to a five-stage system continuously operated with cell recycling so that differences of 2degreesC (between one reactor to the next) and 8degreesC (between the first reactor at the highest temperature and the fifth at the lowest temperature) were kept among the reactors for each temperature range. The entire system was fed through the first reactor. The lowest values of biomass and viability were obtained for reactor R-3 located in the middle of the system. The highest yield of biomass was obtained in the effluent when the system was operated at 35-43degreesC. This nonconventional system was set up to simulate the local fluctuations in temperature and nutrient concentrations that occur in different regions of the medium in an industrial bioreactor for fuel ethanol production mainly in tropical climates. Minimized cell death and continuous sugar utilization were observed at temperatures normally considered too high for Saccharomyces cerevisiae fermentations.
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To simplify computer management, various administration systems based on wired connections adopt advanced techniques to manage software configuration. Nevertheless, the strong relation between hardware and software makes for an individualism of that management, besides penalizing computational mobility and ubiquity. All these issues lead to degradation of scalability, flexibility and the facility to install and maintain distributed applications. This article presents an environment for centralized wireless communication network management, named WSE-OS (Wireless Sharing Environment - Operating Systems): a model based on Virtual Desktop Infrastructure (VDI) which associates virtualization techniques and safe remote access systems to create a distributed architecture as a base for a managing system. WSE-OS is capable of accomplishing the replication of operating system images using wireless communication network, besides offering abstraction of hardware to its clients, making the management more flexible and independent of wired connections. Results obtained from this work indicate that WSE-OS allows disseminating, through a single software configuration, the execution of data related to operating system images in client computers. WSE-OS can also be used as a management tool for operating systems in a wireless network.
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This paper presents the basic principles of the evaporative cooling process for human thermal comfort, the principles of operation for the direct evaporative cooling system and the mathematical development of the equations of thermal exchanges, allowing the determination of the effectiveness of saturation. It also presents the results of experimental tests in a direct evaporative cooler that take place in the Air Conditioning Laboratory at the University of Taubate Mechanical Engineering Department, and the experimental results are used to determinate the convective heat transfer co-efficient and to compare with the mathematical model. (c) 2005 Elsevier Ltd and IIR. All rights reserved.
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The effects of combustion driven acoustic oscillations in carbon monoxide and nitrogen oxides emission rates of a combustor operated with liquefied petroleum gas (LPG) were investigated. Because the fuel does not contain nitrogen, tests were also conducted with ammonia injected in the fuel, in order to study the formation of fuel NOx. The main conclusions were: (a) the pulsating combustion process is more efficient than the non-pulsating one and (b) the pulsating combustion process generates higher rates of NOx, with and without ammonia injection, as shown by CO and NO concentrations as function of the O-2 concentration. An increase in the LPG flow rate, keeping constant the air to fuel ratio, increased the acoustic pressure amplitude and the frequency of oscillation. The injection of ammonia had no influence on either pressure amplitude or frequency. (c) 2005 Elsevier Ltd. All rights reserved.
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This paper presents a new single-phase interleaved high power factor boost pre-regulator operating in critical conduction mode, where the switches and boost diode performing zero-current commutations during its turn-off, eliminating the disadvantages related to the reverse recovery losses and electromagnetic interference problems of the boost diode, when operating in the continuous conduction mode. The interleaving technique is applied in the power cell, providing a significant input current ripple reduction in comparison to discontinuous mode of operation, due to its input current continuous conduction operation. This paper presents a complete modeling for the converter operating in critical conduction mode, resulting in an improved design procedure for interleaved techniques with high input power factor, a complete design procedure, and main simulation results from a design example with two interleaved cells rated at 1kW, 400V output voltage and 220V rms input voltage.
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This work describes the use of a large-aperture PVDF receiver in the measurement of liquid density and composite material elastic constants. The density measurement of several liquids is obtained with accuracy of 0.2% using a conventional NDE emitter transducer and a 70-mm-diameter, 52-mu m P(VDF-TrFE) membrane with gold electrodes. The determination of the elastic constants is based on the phase velocity measurement. Diffraction can lead to errors around 1% in velocity measurement when using alternatively the conventional pair of ultrasonic transducers (1-MHz frequency and 19-mm-diameter) operating in through-transmission mode, separated by a distance of 100 mm. This effect is negligible when using a pair of 10-MHz, 19-mm-diameter transducers. Nevertheless, the dispersion at 10 MHz can result in errors of about 0.5%, when measuring the velocity in composite materials. The use of an 80-mm diameter, 52-mu m-thick PVDF membrane receiver practically eliminates the diffraction effects in phase velocity measurement. The elastic constants of a carbon fiber reinforced polymer were determined and compared with the values obtained by a tensile test. (C) 2009 Elsevier B. V. All rights reserved.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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We study curves of genus 3 over algebraically closed fields of characteristic 2 with the canonical theta characteristic totally supported in one point. We compute the moduli dimension of such curves and focus on some of them which have two Weierstrass points with Weierstrass directions towards the support of the theta characteristic. We answer questions related to order sequence and Weierstrass weight of Weierstrass points and the existence of other Weierstrass points with similar properties.