Made available in DSpace on 2014-06-11T19:31:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-07-02Bitstream added on 2014-06-13T19:20:50Z : No. of bitstreams: 1 gabriel_cpc_dr_botfca.pdf: 833335 bytes, checksum: 4475ce35625358eeb8afee9bf905ce59 (MD5) / A região de Bastos-SP é responsável por grande parte da produção brasileira de ovos. Muitas granjas nesta região produzem a própria ração para alimentação de suas aves através da trituração de milho e soja com motores elétricos muitas vezes super-dimensionados, trabalhando em vazio ou em horário de pico. Esta atividade é responsável por grande parte do gasto energético da empresa. Existem dois fatores que avaliam o modo de utilização desta energia, denominados fator de potência ( fp) e fator de carga ( fc), que indicam a eficiência e racionalidade da forma de utilização da energia elétrica, respectivamente. A necessidade de uma avaliação global da utilização da energia, levando em consideração os dois fatores citados, é realizada por especialistas da área energética para a determinação da situação real da empresa. A lógica fuzzy estabelece a criação de algoritmos genéticos, que são capazes de imitar parte do raciocínio humano. Esta lógica aproxima métodos computacionais e o raciocínio humano, o que possibilita a avaliação global da empresa por métodos computacionais e não mais de especialistas da área energética. Estes métodos são sintetizados criando-se um programa computacional baseado em regras criadas a partir desta lógica, que denominamos controlador fuzzy.O presente trabalho preocupou-se em criar um controlador fuzzy para a avaliação do faturamento do consumo de energia elétrica e demanda de potência ativa e reativa em uma empresa de avicultura de postura. Para isto, coletaram-se dados sobre o comportamento dos parâmetros elétricos, tais como: fator de potência, fator de carga, demanda e consumo ativo. A criação de um controlador fuzzy necessita de um processador de entrada, um conjunto de regras lingüísticas, um método de inferência fuzzy e um processador de saída, gerando um número real como saída... / The region of Bastos-SP is responsible for great part of the Brazilian egg production. Many farms in this region produce the proper ration for feeding of its birds through the triturate of maize and soy with electric engines many large sized times, working in emptiness or schedule of peak. This activity is responsible for great part of the energy expense of the company. Two factors exist that evaluate the way of use of this energy, called power factor ( fp) and load factor ( fc), that indicates the efficiency and rationality of the form of use of the electric energy, respectively. The necessity of a global evaluation of the use of the energy, leading in consideration the two cited factors, is carried through by specialists of the energy area for the determination of the real situation of the company. The logic fuzzy establishes the creation of genetic algorithms, that are capable to imitate part of the human reasoning. This logic approaches computational methods and the human reasoning, what it not more than makes possible the global evaluation of the company for computational methods and specialists of the energy area. These methods are synthecized creating a based computational program in rules created from this logic, that we call controller fuzzy.The present work was worried in creating a controller fuzzy for the evaluation of the invoicing of the consumption of electric energy and demand of active and reactive power in a company of position poultry keeping. For this, they had been collected given on the behavior of the electric parameters, such as: factor of power, load factor, demand and active consumption. The creation of a controller fuzzy needs an entrance processor, a set of linguistic rules, a method of inference fuzzy and a processor of exit, generating a real number as exit. Defining the entrance 0 variable as the load and power factor,... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:22:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-05-31Bitstream added on 2014-06-13T20:09:50Z : No. of bitstreams: 1 guelfi_r_me_ilha.pdf: 667745 bytes, checksum: 4cf02e10ba92af5e81fd3f18fda6f6cd (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / No presente trabalho é apresentado um método para o cálculo de volumes determinados por K-Hiperbolóides de Carga e Potência, de modo a reduzir os gastos de empresas consideradas, em relação ao fator de potência. A redução de gastos é obtida alterando-se o valor máximo do fator potência que se pretende chegar, do fator de potência ideal 1, para o fator de potência de referência 0,92, ou mantendo-o quando já estiver acima de 0,92. Quando o fator de potência é maior ou igual a 0,92 ele já está eficiente, assim, não há necessidade de se chegar ao fator de potência ideal. É realizada uma comparação entre um método existente na literatura e o método proposto no presente trabalho, para determinar os pontos em que estes métodos diferem no cálculo dos volumes determinados pelos K-Hiperbolóides de Carga e Potência e mostrar a eficácia do método proposto. Estes métodos são equiparados, com relação a redução obtida no faturamento da conta de energia elétrica. A redução no faturamento da conta de energia elétrica que deve ser pago à concessionária é obtida por meio da diminuição da demanda contratada pela empresa; por sua vez a diminuição desta demanda é alcançada através da fórmula do fator de carga. Considerando-se a demanda média e o maior fator de carga obtido no período em estudo, encontra-se assim, uma nova demanda máxima menor que a demanda atual utilizada pela empresa. Logo, esta demanda máxima passa a ser a demanda que será contratada pela empresa, assim, esta nova demanda resulta em uma nova fatura que deve ser paga a concessionária de energia elétrica, menor que a fatura atual. / The present work presents a method for the calculation of volumes determined for K- Load and Power Hyperboloid, in order to reduce the expenses of considered companies, in relation to the power factor. The reduction of expenses is gotten by changing the maximum value of the wished power factor, of the ideal power factor1, to the reference power factor 0,92,or keeping it when it s above 0,92. When the power factor is higher or equal 0,92, it s already efficient, thus, it is not necessary to achieve the ideal power factor. A comparison is carried between an existing method in the literature and the considered method in the present work, to determine the points where these methods differ from each other in the calculation of the volumes determined for the K-Load and Power Hyperboloid and to show the effectiveness of the considered method. These methods are equalized, regarding the reduction gotten in the invoicing of the electric energy account. The reduction in the invoicing of the account of electric energy that must be paid to the concessionaire is gotten through the reduction of the contracted demand by the company; in turn the reduction of this demand is reached through the formula of the load factor. Considering the average demand and the highest load factor gotten in the period in study, this way a new demand, lower than the current demand used by the company, is gotten. Therefore, this maximum demand starts to be the demand that will be contracted by the company, thus, this new demand results in a new invoice which must be paid to the concessionaire of electric energy, lower than the current invoice.

Orientador: Angelo Cataneo / Banca: Helenice de Oliveira Florentino Silva / Banca: Ivam Resina / Banca: Flávio Ferrari Aragon / Banca: Fernando Natal de Pretto / Resumo: A região de Bastos-SP é responsável por grande parte da produção brasileira de ovos. Muitas granjas nesta região produzem a própria ração para alimentação de suas aves através da trituração de milho e soja com motores elétricos muitas vezes super-dimensionados, trabalhando em vazio ou em horário de pico. Esta atividade é responsável por grande parte do gasto energético da empresa. Existem dois fatores que avaliam o modo de utilização desta energia, denominados fator de potência ( fp) e fator de carga ( fc), que indicam a eficiência e racionalidade da forma de utilização da energia elétrica, respectivamente. A necessidade de uma avaliação global da utilização da energia, levando em consideração os dois fatores citados, é realizada por especialistas da área energética para a determinação da situação real da empresa. A lógica fuzzy estabelece a criação de algoritmos genéticos, que são capazes de imitar parte do raciocínio humano. Esta lógica aproxima métodos computacionais e o raciocínio humano, o que possibilita a avaliação global da empresa por métodos computacionais e não mais de especialistas da área energética. Estes métodos são sintetizados criando-se um programa computacional baseado em regras criadas a partir desta lógica, que denominamos controlador fuzzy.O presente trabalho preocupou-se em criar um controlador fuzzy para a avaliação do faturamento do consumo de energia elétrica e demanda de potência ativa e reativa em uma empresa de avicultura de postura. Para isto, coletaram-se dados sobre o comportamento dos parâmetros elétricos, tais como: fator de potência, fator de carga, demanda e consumo ativo. A criação de um controlador fuzzy necessita de um processador de entrada, um conjunto de regras lingüísticas, um método de inferência fuzzy e um processador de saída, gerando um número real como saída... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The region of Bastos-SP is responsible for great part of the Brazilian egg production. Many farms in this region produce the proper ration for feeding of its birds through the triturate of maize and soy with electric engines many large sized times, working in emptiness or schedule of peak. This activity is responsible for great part of the energy expense of the company. Two factors exist that evaluate the way of use of this energy, called power factor ( fp) and load factor ( fc), that indicates the efficiency and rationality of the form of use of the electric energy, respectively. The necessity of a global evaluation of the use of the energy, leading in consideration the two cited factors, is carried through by specialists of the energy area for the determination of the real situation of the company. The logic fuzzy establishes the creation of genetic algorithms, that are capable to imitate part of the human reasoning. This logic approaches computational methods and the human reasoning, what it not more than makes possible the global evaluation of the company for computational methods and specialists of the energy area. These methods are synthecized creating a based computational program in rules created from this logic, that we call controller fuzzy.The present work was worried in creating a controller fuzzy for the evaluation of the invoicing of the consumption of electric energy and demand of active and reactive power in a company of position poultry keeping. For this, they had been collected given on the behavior of the electric parameters, such as: factor of power, load factor, demand and active consumption. The creation of a controller fuzzy needs an entrance processor, a set of linguistic rules, a method of inference fuzzy and a processor of exit, generating a real number as exit. Defining the entrance 0 variable as the load and power factor,... (Complete abstract click electronic access below) / Doutor

Morgongåva is an urban centre in Sweden, with several challenges in the electrical power grid. In order to use the power grid more efficiently, this report investigates potentials of installing a battery energy storage system (BESS). Focus lies on finding economic and technical benefits of reducing power peaks, which occur during high demand hours when transmitting energy is more expensive. This method is referred to as peak shaving. Further, economic calculations if installing a BESS are based on electricity pricing data. Calculations regarding technical benefits are based on net power demand data. Further, the study shows that the usage of the grid, which was measured with the load factor, would increase and thus allow installation of more power sources and connecting more load to the grid. The load factor was estimated to increase by an average of 2.12 percent each month in 2019. In one year, the economic profit was estimated to be 91,000 kr. The conclusion is that there are economic profits for Sala-Heby Energi of installing a BESS, but more importantly a BESS has technical consequences in the power grid. Where technical benefits are important in order to reach the goals of Agenda 2030 but also to obtain a more reliable grid for the customers. A sensitivity analysis shows that the model is robust. Thus, the conclusion is that Sala-Heby Energi and the local electricity grid in Morgongåva would benefit from installing a BESS.

In spite of many multiaxial fatigue life prediction methods proposed over decades of research, no universally accepted approach yet exists. A multiaxial fatigue damage model developed for approximately proportional random amplitude loading is proposed in this study. A normal strain based analysis incorporating the multiaxial state of stress is conducted along a critical orientation assuming a constant strain ratio. The dominant deformation direction is chosen to be the critical orientation which is selected with the help of a principal strain histogram generated from the given multiaxial loading history. The uniaxial cyclic stress-strain curve is modified for the biaxial state of stress present along the critical orientation for the plane stress conditions. Modified versions of Morrow's and of Smith, Watson, and Topper's (SWT) mean-stress models are used to incorporate mean stresses. A maximum shear strain based analysis is, in addition, conducted to check for the shear dominant fatigue crack growth possibility along the critical direction. The most damaging maximum shear strain is chosen after analyzing the in-plane and the two out-of-plane shear strains. The minimum of the two life values obtained from SWT model and the shear strain model is compared with the life estimated by the proposed model with the modified Morrow's mean stress model. The former is essentially the life predicted by Socie. The results of the proposed model, as reduced to the uniaxial case, are also compared with the experimental data obtained by conducting one-channel random amplitude loading history experiments. / Master of Science

This dissertation argues that admission control should be applied as early as possible within a system. To that end, this dissertation examines the benefits and trade-offs involved in applying admission control to a networked computer system at the level of the network interface hardware. Admission control has traditionally been applied in software, after significant resources have already been expended on processing a request. This design decision leads to systems whose algorithmic cost is a function of the load applied to the system, rather than the load admitted to the system. By performing admission control at the network interface, it is possible to develop systems whose algorithmic cost is a function of load admitted to the system, rather than load applied to the system. Such systems are able to deal with excessive applied loads without exhibiting performance degradation. This dissertation first examines existing admission control approaches, focussing on the cost of admission control within those systems. It then goes on to develop a model of system behaviour under overload, and the impact of admission control on that behaviour. A new class of admission control mechanisms which are able to perform load rejection using the network interface hardware are then described, along with a prototype implementation using commodity hardware. A prototype implementation in the FreeBSD operating system is evaluated for a variety of network protocols and performance is compared to the standard FreeBSD implementation. Performance and scalability under overload is significantly improved.

Thesis (Ph. D.)--Florida State University, 2005. / Includes bibliographical references (p. 175-176). Also available online via the Florida State University electronic theses website (http://etd.lib.fsu.edu/).

In preliminary building energy assessments, it is often desired to estimate a motor's input power. Motor power estimates in this context should be rapid, safe, and noninvasive. Existing methods for motor input power estimation, such as direct measurement (wattmeter), Current Method, and Slip Method were evaluated. If installed equipment displays input power or average current, then using such readings are preferred. If installed equipment does not display input power or current, the application of wattmeters or current clamps is too time-consuming and invasive for the preliminary energy audit. In that case, if a shaft speed measurement is readily available, then the Slip Method is a satisfactory method for estimating motor input power. An analysis of performance data for 459 motors suggests comparable performance for predicting normalized (to the nominal motor input power) motor input power with the Current and Slip Methods: 10.0% and 9.9% RMSE, respectively. Both of these methods may be improved by applying regression on the predicted variable and/or nameplate parameters. For example, the Slip Method could be improved by applying a second-order regression, thereby reducing the predicted load factor residual RMSE of the data set from 9.0% to 8.2%. The Current and Slip Methods were also evaluated on two real motors. The normalized (to the nominal motor input power) predicted input power RMSE for the Current Method was on average 15% for the two motors; for the Slip Method the corresponding average was 17.5%. In some cases, shaft speed measurements may not be available. A temperature-based approach for estimating motor input power was investigated. Other required parameters include ambient temperature, motor efficiency, and a motor thermal constant. The temperature approach offers quick, safe, and non-invasive motor power estimation. However, thermal coefficients may vary significantly across motors and a model to predict the thermal coefficients has yet to be developed. Furthermore, the temperature approach has a very strong dependence on motor efficiency uncertainty. Experiments were performed on two motors to determine their motor thermal constants. If a motor's thermal constants and running efficiency are known, then this method gave motor input power estimates with a RMSE (normalized to the nominal input power) on the order of 4% for the studied motors.

In this thesis, the seat inventory control problem is studied for airlines from the perspective of a risk-averse decision maker. There are only a few studies in the revenue management literature that consider the risk factor. Most of the studies aim at finding the optimal seat allocations while maximizing the expected revenue and do not take the variability of the revenue and hence a risk measure into account. This study aims to decrease the variance of the revenue by increasing the capacity utilization called load factor in the revenue management literature. In addition to expected revenue, load factor is an important performance measure the state companies work with. For this purpose, two types of models with load factor formulations are proposed. This thesis is the first study in the revenue management literature for the airline industry that uses the load factor formulations in the mathematical models. It is an advantage to work with load factor formulations since the models with load factor formulations are much easier to formulate and solve as compared to other risk sensitive models in the literature. The results of the proposed models are evaluated by using simulation for a sample network under different scenarios. The models we propose allow us to control the variability of revenue by changing the used capacity of the aircraft. This is at the expense of a decrease in the revenue under some scenarios. The models we propose perform satisfactorily under all scenarios and they are strongly recommended to be used especially for the small-scale airline companies and state companies and for scheduling new flights even in large scale, well established airline companies.

This thesis addresses the results of an experimental and analytical investigation aimed at examining the static load-displacement response of braced plane frame structures composed of fiber reinforced polymeric (FRP) composite material structural members manufactured by the pultrusion process. In the experimental part of this investigation, eighteen full-scale lateral loading tests for FRP composite frames with different brace configurations and beam column connection types were performed. The load-displacement responses of such frames were measured and are reported herein. In the analytical part of this investigation, a frame analysis method that accounts for the anisotropic nature of FRP composite material structural members was investigated. The results from the experimental work are compared with the results from the analytical procedures. The effects of various structural parameters of the frame such as (1) effective mechanical material properties of members, (2) beam-column connection types, and (3) the influence of diagonal structural members on the lateral load-displacement response of the braced plane frames are also investigated. The numerical load-displacement results from the proposed FRP composite frames analysis procedure provided good agreement with the results from the full-scale laboratory tests.