933 resultados para model driven system, semantic representation, semantic modeling, enterprise system development


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The occurrence of problems related to the scattering and tangling phenomenon, such as the difficulty to do system maintenance, increasingly frequent. One way to solve this problem is related to the crosscutting concerns identification. To maximize its benefits, the identification must be performed from early stages of development process, but some works have reported that this has not been done in most of cases, making the system development susceptible to the errors incidence and prone to the refactoring later. This situation affects directly to the quality and cost of the system. PL-AOVgraph is a goal-oriented requirements modeling language which offers support to the relationships representation among requirements and provides separation of crosscutting concerns by crosscutting relationships representation. Therefore, this work presents a semi-automatic method to crosscutting concern identification in requirements specifications written in PL-AOVgraph. An adjacency matrix is used to identify the contributions relationships among the elements. The crosscutting concern identification is based in fan-out analysis of contribution relationships from the informations of adjacency matrix. When identified, the crosscutting relationships are created. And also, this method is implemented as a new module of ReqSys-MDD tool

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Este trabalho teve como objetivo implementar um modelo computacional para simular a dinâmica operacional de uma linha industrial de abate de suínos. O sistema real modelado pertence à empresa Frigorífico Frimesa, sediada no município de Medianeira (PR). O modelo implementado é tipo dinâmico, discreto e estocástico. Este simula 34 operações unitárias e foi estruturado com o uso da linguagem de simulação EXTEND TM. Para validação do modelo foram coletados dados relativos a cinco dias de operação, em que foram abatidos 1.346, 1.630, 1.360, 1.585 e 1.550 suínos, respectivamente. Como parâmetros de comparação entre os dados obtidos a partir do sistema e gerados pelo modelo foram selecionadas as seguintes variáveis: (i) tempo de duração da operação; (ii) tempo de deslocamento da insensibilização até a depiladeira; (iii) tempo deslocamento da insensibilização até a câmara fria; (iv) número de carcaças re-inspecionadas; e (v) número final de carcaças. Na validação do modelo, foi constatado que, para a variável tempo de duração da operação por meio do teste Tukey a 1% de significância, não foram detectadas diferenças estatísticas entre os valores obtidos do sistema real e os gerados pelo modelo. Considerando-se esta e outras análises, foi concluído que o modelo aplica-se à finalidade para a qual foi implementado. Sendo assim, foram realizadas duas análises de sensibilidade. Na primeira, ao alterar o número de suínos a abater de 1 mil para 2 mil, foi determinado que os tempos de duração da operação variariam de 6,20 a 10,10 h, respectivamente. Para a segunda, ao abater 1.340 suínos e alterar a velocidade das nórias de 300 para 600 animais por hora, o tempo de duração da operação passou de 8,10 para 7,40 h, respectivamente.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The objective of this study was to determine models for ME requirements for broiler breeder pullets using the factorial method. The influence of the temperature on maintenance ME requirements was determined by experiments conducted in three environmental rooms with temperature kept constant at 15, 22, and 30°C, using the comparative slaughter technique. The energy requirements for weight gain were determined based on the body energy content and efficiency of energy utilization for weight gain. Two ME requirement models for each age were developed using the coefficients for maintenance and weight gain. The models for 3 to 8 wk were ME = W 0.75 (186.52 - 1.94T) + 2.47WG, and ME = W 0.75 (174 - 1.88T) + 2.83WG; for 9 to 14 wk, ME = W 0.75 (186.52 - 1.94T) + 2.69WG, and ME = W 0.75 (174 - 1.88T) + 2.50WG; and 15 to 20 wk, ME = W 0.75 (186.52 - 1.94T) + 2.76WG, and ME = W 0.75 (174 - 1.88T) + 3.24WG. In these equations, W is BW (kg), T is temperature (°C), and WG is daily weight gain (g). These models were compared to the breeder's recommendations in a feeding trial from 5 to 20 wk of age. Models 1 and 2 provided energy intakes that promoted BW smaller than the breeder's recommendation. However, all breeder pullets had weights above the standard recommendation. Model 2 gave the smallest ME intake and BW close to the standard recommendation and provided the best prediction of ME requirements.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Harris-Todaro model of the rural-urban migration process is revisited under an agent-based approach. The migration of the workers is interpreted as a process of social learning by imitation, formalized by a computational model. By simulating this model, we observe a transitional dynamics with continuous growth of the urban fraction of overall population toward an equilibrium. Such an equilibrium is characterized by stabilization of rural-urban expected wages differential (generalized Harris-Todaro equilibrium condition), urban concentration and urban unemployment. These classic results obtained originally by Harris and Todaro are emergent properties of our model.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The study of algorithms for active vibration control in flexible structures became an area of enormous interest for some researchers due to the innumerable requirements for better performance in mechanical systems, as for instance, aircrafts and aerospace structures. Intelligent systems, constituted for a base structure with sensors and actuators connected, are capable to guarantee the demanded conditions, through the application of diverse types of controllers. For the project of active controllers it is necessary, in general, to know a mathematical model that enable the representation in the space of states, preferential in modal coordinates to permit the truncation of the system and reduction in the order of the controllers. For practical applications of engineering, some mathematical models based in discrete-time systems cannot represent the physical problem, therefore, techniques of identification of system parameters must be used. The techniques of identification of parameters determine the unknown values through the manipulation of the input (disturbance) and output (response) signals of the system. Recently, some methods have been proposed to solve identification problems although, none of them can be considered as being universally appropriate to all the situations. This paper is addressed to an application of linear quadratic regulator controller in a structure where the damping, stiffness and mass matrices were identified through Chebyshev's polynomial functions.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Reliability is a key aspect in power system design and planning. Maintaining a reliable power system is a very important issue for their design and operation. Under the new competitive framework of the electricity sector, power systems find ever more and more strained to operate near their limits. Under this new scenario, it is crucial for the system operator to use tools that facilitate an energy dispatch that minimizes possible power cuts. This paper presents a mathematical model to calculate an energy dispatch that considers security constraints (single contingencies in transmission lines and transformers). The model involves pool markets and fixed bilateral contracts. Traditional methodologies that include security constraints are usually based in multistage dispatch processes. In this case, we propose a single-stage model that avoids the economic inefficiencies which result when conventional multi-stage dispatch approaches are applied. The proposed model includes an AC representation of the transport system and allows calculating the cost overruns incurred in due to reliability restrictions. We found that complying with fixed bilateral contracts, when they go above certain levels, might lead to congestion problems in transmission lines.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

O objetivo desta dissertação é desenvolver uma ferramenta computacional para a análise do potencial de bombeamento de água com base nos valores de velocidades de vento de uma localidade, utilizando um aerogerador de pequeno porte acoplado a um conjunto motobomba convencional, por intermédio de um inversor de frequência. No trabalho são apresentados dois métodos para o cálculo da vazão. O método 1 utiliza um modelo teórico, enquanto que no método 2 o modelamento é feito a partir de dados de bombeamento obtidos em laboratório. Os dois métodos descrevem o funcionamento de um sistema de bombeamento de água envolvendo os equipamentos citados. Utilizando os modelos matemáticos descritos, foi criado um programa em linguagem Delphi®, para a obtenção dos valores de vazão e volume de água bombeada, além do número de pessoas que podem ser atendidas, com base nos dados de velocidade de vento do local, para com isso, ser possível analisar a viabilidade ou não de instalação do sistema. O funcionamento do programa é descrito através de um exemplo, que contém valores reais de velocidade de vento, e cujos resultados são analisados de forma a possibilitar seu entendimento.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The objective of this paper is to introduce a model, called the Model of the System of Schemes of Actions and Operations on Symbols and Signs (MoSSAOSS), that articulates a systemic, systematic, and synthetic view of some of the principal theoretic and experimental results obtained by Piaget and his coworkers. Here, the term model means a schematic representation of experience, the relation of whose elements can be explored by means of logic and mathematics in order to deduce properties that correspond, in a sufficiently accurate form, to direct observable empirical properties. The MoSSAOSS model is intended to reveal in an abstract and simplified form, and through explicit hypothesis and definitions, the general structure and function of the System of Schemes of Actions and Operations on Symbols and Signs. It is this system that furnishes the elements that make possible the diverse structures necessary for the knowledge of the epistemic subject, the subject of knowledge, the stages in their construction, and the attribution of significations to objects, to situations, and to the actions and operations of the subject itself.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We investigate the formation of molecules under the action of external field acting during the atomic collision. To describe this process, the collision of atomic pairs, we use the Morse oscillator model driven The study was developed from the standpoint of classical mechanics by analyzing the sensitivity of the system with respect to initial conditions, the verification of chaotic dynamics associated with the process of formation of molecules with laser and analysis of system dynamics and the likelihood of photoassociation in response to the external field parameters

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The term model refers to any representation of a real system. The use of models in Hydrogeology can be valuable predictive tools for management of groundwater resources. The numeric models of groundwater flow, object of this study, consist on a set of differential equations that describe the water flow in the porous medium. In this context, numeric simulations were made for a sub-basin located at Cara Preta farm – Santa Rita do Passa Quatro – SP. The aquifer at the local is composed by rocks of Pirambóia Formation, which is part of Guarani Aquifer System. It was developed a conceptual model from previous studies in the area, and from that, simulations were made through the software Visual Modflow®. The conceptual model established previously was considered consistent through the results of simulation.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Software Engineering originated with the motivation to mass produce components for increased productivity in production systems. Since its origins, numerous studies have been proposed on the subject as new features in the creation of systems, like the Object- Oriented Programming and Aspect-Oriented Programming, have been established and methodologies have been developed to control them efficiently. However, years of studies in the area were not sufficient to create a methodology for reusing software artifacts really efficient and easy enough to be widespread. Given this, the Model-Driven Development (MDD) is trying to promote it using the modeling of systems as a reference, becoming part of it and establishing a huge productivity gain. One of his approaches is called Model-Driven Software Development (MDSD), which focuses on improving the practices and systems development using Domain-Specific Languages (DSL) for this purpose. In this Final Paper, Xtext is used as a tool to prove the productivity and efficiency of this approach, and for that bibliographic studies were made on the approach and the tool, and show the methodology and a case study to demonstrate results and conclusions regarding this work