994 resultados para Porter´s five competitive forces
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The dynamism and ongoing changes that the electricity markets sector is constantly suffering, enhanced by the huge increase in competitiveness, create the need of using simulation platforms to support operators, regulators, and the involved players in understanding and dealing with this complex environment. This paper presents an enhanced electricity market simulator, based on multi-agent technology, which provides an advanced simulation framework for the study of real electricity markets operation, and the interactions between the involved players. MASCEM (Multi-Agent Simulator of Competitive Electricity Markets) uses real data for the creation of realistic simulation scenarios, which allow the study of the impacts and implications that electricity markets transformations bring to different countries. Also, the development of an upper-ontology to support the communication between participating agents, provides the means for the integration of this simulator with other frameworks, such as MAN-REM (Multi-Agent Negotiation and Risk Management in Electricity Markets). A case study using the enhanced simulation platform that results from the integration of several systems and different tools is presented, with a scenario based on real data, simulating the MIBEL electricity market environment, and comparing the simulation performance with the real electricity market results.
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A forma como aprendemos depende do contexto tecnológico e sociocultural que nos rodeia, actualmente a inclusão de tecnologia recente na sala de aula não é mais considerada opcional, mas sim uma necessidade pois a forma como o aluno aprende está em constante evolução. Tendo em atenção esta necessidade, foi desenvolvido no decorrer desta tese um simulador em realidade virtual que utiliza comandos/interfaces hápticos. O objectivo deste simulador é ensinar conceitos de física de forma interactiva. Os dispositivos hápticos permitem adicionar o sentido táctil ou de toque à interacção entre homem e máquina, permitindo assim aceder a novas sensações relativas ao seu uso nomeadamente com objectivos de aprendizagem. O simulador desenvolvido designado por “Forces of Physics” aborda três tipos de forças da física: forças de atrito, forças gravitacionais e forças aerodinâmicas. Cada tipo de força corresponde a um módulo do simulador contendo uma simulação individual em que são explicados conceitos específicos dessa força num ambiente visual estimulante e com uma interacção mais realista devido à inclusão do dispositivo háptico Novint Falcon. O simulador foi apresentado a vários utilizadores bem como á comunidade científica através de apresentações em conferências. A avaliação foi realizada com recurso a um questionário com dez perguntas, cinco de sobre aprendizagem e cinco sobre a utilização, tendo sido preenchido por 14 utilizadores. O simulador obteve uma boa recepção por parte dos utilizadores, tendo vários utilizadores expressado as suas opiniões sobre estado actual do simulador, do futuro do mesmo e da respectiva validade para uso na sala de aula.
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The aim of this case series was to describe the clinical, laboratory and epidemiological characteristics and the presentation of bacillary angiomatosis cases (and/or parenchymal bacillary peliosis) that were identified in five public hospitals of Rio de Janeiro state between 1990 and 1997; these cases were compared with those previously described in the medical literature. Thirteen case-patients were enrolled in the study; the median age was 39 years and all patients were male. All patients were human immunodeficiency virus type 1 (HIV-1) infected and they had previous or concomitant HIV-associated opportunistic infections or malignancies diagnosed at the time bacillary angiomatosis was diagnosed. Median T4 helper lymphocyte counts of patients was 96 cells per mm³. Cutaneous involvement was the most common clinical manifestation of bacillary angiomatosis in this study. Clinical remission following appropriate treatment was more common in our case series than that reported in the medical literature, while the incidence of relapse was similar. The frequency of bacillary angiomatosis in HIV patients calculated from two of the hospitals included in our study was 1.42 cases per 1000 patients, similar to the frequencies reported in the medical literature. Bacillary angiomatosis is an unusual opportunistic pathogen in our setting.
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Whipple's disease (WD) is a rare systemic disease of infectious etiology which involves the small intestine but can virtually affect any organ. We present here five cases (four males and one female) ranging in age from 20 to 59 years. All patients had intestinal involvement associated or not with clinical manifestations linked to this organ. Vegetation in the tricuspid valve was observed in one patient, suggesting endocarditis caused by Tropheryma whippelii, with disappearance of the echocardiographic alterations after treatment. In one of the male patients the initial clinical manifestation was serologically negative spondylitis, with no diarrhea occurring at any time during follow-up. Ocular involvement associated with intestinal malabsorption and significant weight loss were observed in one case. In the other two cases, diarrhea was the major clinical manifestation. All patients were diagnosed by histological examination of the jejunal mucosa and, when indicated, of extraintestinal tissues by light and electron microscopy. After antibiotic treatment, full remission of symptoms occurred in all cases. A control examination of the intestinal mucosa performed after twelve months of treatment with sulfamethoxazole-trimethoprim revealed the disappearance of T. whippelii in four patients. The remaining patient was lost to follow-up.
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Dissertation submitted in partial fulfillment of the requirements for degree of Master in Statistics and Information Management.
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The authors report five cases of seabather's eruption, a typical dermatitis associated predominantly to the jellyfish Linuche unguiculata (Cnidaria), that causes erythematous and pruriginous papules on areas of the skin of bathers covered by swimsuits. The rash is characteristic and the eruption is commom in the Caribbean, Florida, Mexico and Gulf States of USA. The cases are the first reported in Brazil and larvae of the jellyfish are present in the waters where the accidents happened.
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Currently excessive fossil fuel consumption has become a serious problem. People are searching for new solutions of energy production and there are several options to obtain alternative sources of energy without further devastating the already destroyed environment. One of these solutions is growing microalgae, from which biodiesel can be obtained. The microalgae production is a growing business because of its many useful compounds. In order to collect these compounds microalgae must first be harvested and then dried. Nowadays the solutions used for drying use too much energy and therefore are too expensive and not sustainable. The goal of this project, one of the possible choices during the EPS@ISEP 2013 Spring, was to develop a solar microalgae dryer. The multinational team involved in its development was composed of five students, from distinct countries and fields of study, and was the responsible for designing a solar microalgae dryer prototype for the microalgae laboratory of the chemical engineering department at ISEP, suitable for future tests and incorporating control process (in order not to destroy the microalgae during the drying process). The solar microalgae dryer was built to work as a distiller that gets rid of the excess water from the microalgae suspension. This paper presents a possible solution for this problem, the steps to create the device to harvest the microalgae by drying them with the use of solar energy (also used as an energy source for the solar dryer control system), the technologies used to build the solar microalgae dryer, and the benefits it presents compared to current solutions. It also presents the device from the ethical and sustainable viewpoint. Such alternative to already existing methods is competitive as far as energy usage is concerned.
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The antifungal activities of itraconazole, ketoconazole, fluconazole, terbinafine and griseofulvin were tested by broth microdilution methods against 71 isolates of dermatophytes isolated from Nigerian children. Most drugs were very active against all the dermatophytes and the MIC 90 ranged from 0.03 to 8.0 µg/mL. This appears to be the first documented data on the antifungal susceptibility testing of isolates of dermatophytes from Nigerian children.
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The development of nations depends on energy consumption, which is generally based on fossil fuels. This dependency produces irreversible and dramatic effects on the environment, e.g. large greenhouse gas emissions, which in turn cause global warming and climate changes, responsible for the rise of the sea level, floods, and other extreme weather events. Transportation is one of the main uses of energy, and its excessive fossil fuel dependency is driving the search for alternative and sustainable sources of energy such as microalgae, from which biodiesel, among other useful compounds, can be obtained. The process includes harvesting and drying, two energy consuming steps, which are, therefore, expensive and unsustainable. The goal of this EPS@ISEP Spring 2013 project was to develop a solar microalgae dryer for the microalgae laboratory of ISEP. A multinational team of five students from distinct fields of study was responsible for designing and building the solar microalgae dryer prototype. The prototype includes a control system to ensure that the microalgae are not destroyed during the drying process. The solar microalgae dryer works as a distiller, extracting the excess water from the microalgae suspension. This paper details the design steps, the building technologies, the ethical and sustainable concerns and compares the prototype with existing solutions. The proposed sustainable microalgae drying process is competitive as far as energy usage is concerned. Finally, the project contributed to increase the deontological ethics, social compromise skills and sustainable development awareness of the students.
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The electricity market restructuring, and its worldwide evolution into regional and even continental scales, along with the increasing necessity for an adequate integration of renewable energy sources, is resulting in a rising complexity in power systems operation. Several power system simulators have been developed in recent years with the purpose of helping operators, regulators, and involved players to understand and deal with this complex and constantly changing environment. The main contribution of this paper is given by the integration of several electricity market and power system models, respecting to the reality of different countries. This integration is done through the development of an upper ontology which integrates the essential concepts necessary to interpret all the available information. The continuous development of Multi-Agent System for Competitive Electricity Markets platform provides the means for the exemplification of the usefulness of this ontology. A case study using the proposed multi-agent platform is presented, considering a scenario based on real data that simulates the European Electricity Market environment, and comparing its performance using different market mechanisms. The main goal is to demonstrate the advantages that the integration of various market models and simulation platforms have for the study of the electricity markets’ evolution.
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The gelatinase, urease, lipase, phospholipase and DNase activities of 11 chromoblastomycosis agents constituted by strains of Fonsecaea pedrosoi, F. compacta, Phialophora verrucosa, Cladosporium carrionii, Cladophialophora bantiana and Exophiala jeanselmei were analyzed and compared. All strains presented urease, gelatinase and lipase activity. Phospholipase activity was detected only on five of six strains of F. pedrosoi. DNase activity was not detected on the strains studied. Our results indicate that only phospholipase production, induced by egg yolk substrate, was useful for the differentiation of the taxonomically related species studied, based on their enzymatic profile.
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Biomechanical gait parameters—ground reaction forces (GRFs) and plantar pressures—during load carriage of young adults were compared at a low gait cadence and a high gait cadence. Differences between load carriage and normal walking during both gait cadences were also assessed. A force plate and an in-shoe plantar pressure system were used to assess 60 adults while they were walking either normally (unloaded condition) or wearing a backpack (loaded condition) at low (70 steps per minute) and high gait cadences (120 steps per minute). GRF and plantar pressure peaks were scaled to body weight (or body weight plus backpack weight). With medium to high effect sizes we found greater anterior-posterior and vertical GRFs and greater plantar pressure peaks in the rearfoot, forefoot and hallux when the participants walked carrying a backpack at high gait cadences compared to walking at low gait cadences. Differences between loaded and unloaded conditions in both gait cadences were also observed.
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Methanol decomposition is one of the key reactions in direct methanol fuel cell (DMFC) state-of-the-art technology, research, and development. However, its mechanism still presents many uncertainties, which, if answered, would permit us to refine the manufacture of DMFCs. The mechanism of methanol decomposition on ruthenium surfaces was investigated using density functional theory and a periodic supercell approach. The possible pathways, involving either initial C−H, C−O or O−H scission, were defined from experimental evidence regarding the methanol decomposition on ruthenium and other metallic surfaces. The study yielded the O−H scission pathway as having both the most favorable energetics and kinetics. The computational data, which present a remarkable closeness with the experimental results, also indicate methanol adsorption, the starting point in all possible pathways, to be of weak nature, implying a considerable rate of methanol desorption from the ruthenium, compromising the reaction.
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The antifungal activities of fluconazole, itraconazole, ketoconazole, terbinafine and griseofulvin were tested by broth microdilution technique, against 60 dermatophytes isolated from nail or skin specimens from Goiania city patients, Brazil. In this study, the microtiter plates were incubated at 28 ºC allowing a reading of the minimal inhibitory concentration (MIC) after four days of incubation for Trichophyton mentagrophytes and five days for T. rubrum and Microsporum canis. Most of the dermatophytes had uniform patterns of susceptibility to the antifungal agents tested. Low MIC values as 0.03 µg/mL were found for 33.3%, 31.6% and 15% of isolates for itraconazole, ketoconazole and terbinafine, respectively.
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In the Yucatan Peninsula of Mexico, 95% of the human cases of Cutaneous Leishmaniasis are caused by Leishmania (Leishmania) mexicana with an incidence rate of 5.08 per 100,000 inhabitants. Transmission is limited to the winter months (November to March). One study on wild rodents has incriminated Ototylomys phyllotis and Peromyscus yucatanicus as primary reservoirs of L. (L.) mexicana in the focus of La Libertad, Campeche. In the present study, the prevalence of both infection and disease caused by L. (L.) mexicana in small terrestrial mammals were documented during five transmission seasons (1994-2004) in five foci of Leishmaniasis in the state of Campeche. Foci separated by only 100 km, with similar relative abundances of small mammals, were found to differ significantly in their prevalence of both symptoms and infection. Transmission rates and reservoir species seemed to change in space as well as in time which limited the implementation of effective control measures of the disease even in a small endemic area such as the south of the Yucatan Peninsula.