• studies_in_simulation

    Cím: Studies in Simulation (McLeod Institute of Simulation Sciences Hungarian Center)

    Kiadó:
    BME GTK ITM

    Kiadás éve:
    2006. július

    Oldalak száma:
    133

  • Cím:
    Model Identification using Intelligent Agents
    Írta:
    András Jávor
    Oldalak száma:
    9-20
    Simulation is an effective tool for investigating the behavior of highly complex systems and determining optimal solutions in a wide range of various fields. In a number of cases however before starting simulation experiments the task is to determine the simulation model representing adequately the system to be investigated. In certain cases they are so called soft systems where in the initial phase the model describing them with sufficient accuracy is not known. Such problems often occur in the field of economy. In this paper a methodology is outlined for identifying the simulation models by model reconstruction using intelligent demons (agents).
  • Cím:
    The Simulation of Rare Events using the RESTART Method
    Írta:
    Gábor Szűcs
    Oldalak száma:
    21-32
    Nowadays the estimation of small probabilities by simulation is one of the key issues in the simulation literature. In a wide range of fields, financial, marketing problems, environmental protection, micro-, and macro-economy, simulation can be used to investigate systems, but after having completed simulation it is an important problem to determine the confidence of the results obtained, particularly in case of the investigation of rare events. In order to get the results with adequate accuracy long simulation time is required. This paper deals with rare event simulation techniques, which helps us to get the solution faster. Three procedures are shown, and an extended version of the RESTART method implemented in Petri nets is described.
  • Cím:
    Simulation of the Choice of Bank Offices using a High Level Petri Net
    Írta:
    Gergely Mészáros-Komáromy
    Oldalak száma:
    33-43
    The reason for analyzing systems by simulation is usually substantiated by their size and complexity. One approach used widely is the application of Petri nets. Highly complex economic and other problems can be solved efficiently using high level Petri nets, e.g. the development of regions. In this paper the highly effective Knowledge Attributed Petri Nets (KAPN) are used. This paper outlines an economic model implemented using KAPN, modeling the decision of bank clients when choosing bank offices. Offices and clients’ homes are connected by roads, building up a complex net. The decision is based on different factors: fixed parameters (the clients’ own preferences), variables changing runtime (interest rate at the office) and experimental values (traveling time required to get to the bank office and the service time at the office).
  • Cím:
    Simulation of Voice Traffic on a Liberalized TELECOM Market using a High Level Petri Net
    Írta:
    András Varga
    Oldalak száma:
    45-59
    A liberalized telecom market has a number of different players, a number of different interconnection and retail services and many different structures depending on how carriers relate to and interconnect with each other, therefore estimating the volume of the voice traffic going through the network of the different carriers on such a market is a highly complex and large economic problem. For solving such problems computer simulation applying high level Petri nets and agents is an effective, flexible and transparent tool. This paper outlines an economic model, which helps to estimate and forecast both at retail and at wholesale level the volume of the voice traffic going through the network of different market players. The model implemented in CASSANDRA 3.0 uses historical data to estimate future trend variables and carrier selection ratios and probabilities. The estimation of the daily traffic is done at a customer segment and traffic direction level. Intelligent agents so called demons can influence different parameters of the trend functions and the physical interconnection points of the different carriers.
  • Cím:
    Portfolio Management to Help Decision Making in Investment in Information Technology
    Írta:
    László Wágner
    Oldalak száma:
    61-79
    The reasons for using the portfolio management in Information Technology planning and investment is: The companies need a way to know that the projects they are selecting are the best projects where overall business mission and enterprise goals are concerned. To show this way we have to analyze a lot of parameters. Parameters should be time, money, resources, company needs, etc. Using Information Technology (IT) portfolio model can help to examine the business challenges, determine future trends in the industry by analyzing customer demands and competitors actions, and evaluate the existing IT portfolio. Portfolio management model can help to identify opportunities to achieve greater business value, competitive advantage and Return On Investment (ROI), and provides companies with a holistic view of their organization and what it will take from a technology, process, and people standpoint to achieve their goals. We have studied the relevant economic principles, for example present value, cash flow, internal rate of return, etc. We have paid attention to the resource management too. We have adopted the risk management model to the Information Technology market. Based on these principles we have created a simulation model to find optimal portfolio. We have showed two algorithms too. The first is an iterative process, the second uses backtracking model.
  • Cím:
    Tax System and Simulation
    Írta:
    Éva Szabó Bonifert
    Oldalak száma:
    81-91
    The equitableness and effectiveness of the tax system just as finding successful compromise between these contradictory requirements are always current problems. In connection with these, investigation of the extent of the state budget and possible reduction of the tax burden are also essential issues. Because of the system complexity and difficulties of an optimal system determination, there is increasingly stronger need to use simulation models in the analysis of tax and subsidy system. By the help of simulation, outcomes of decision alternatives become comparable without expensive experiments with the real system. Agent-based simulation models – in which individual decision-making and behavior are in the center of interest – enlarge instruments of analysis even more and give the chance to improve the quality of elucidation schemes.
  • Cím:
    Vision Modeling by Knowledge Attributed Petri Nets and Synthesized Symbolic Descriptions
    Írta:
    Attila Fűr — Ákos Tóth
    Oldalak száma:
    93-121
    In our days, when intelligent vision systems are needed tools for many applications in robotics, or interactive systems, the perfection of those is highly demanded. Machine vision, as a young science, applies lots of modern mathematical concepts to solve special problems, but the results are not always exquisite. If the problem is well defined, so precise, trusty systems can be built, otherwise the ability of problem-solving, or trustiness does not meet the requirements. The greatest problem of logic-based image processing, is making choice, separating between noise and signal, so that is why it is useful to turn to biologic systems, which are free of decisions, and are based on analogical concepts. In this paper, at first we give an overview in the application area of biologic systems, especially those using neural computing, after that we delineate the five-level intelligent cell-model, and the results of simulation. The cell, and the structured cell-network was implemented using high-level AI-controlled Knowledge Attributed Petri Net (KAPN) based discrete simulation system (CASSANDRA 3.0). This model can be used for studying basic cell functions, or neural learning mechanisms, which are always the most important part of image processing classification units. Although Petri net based simulation could be very precise, it has a great demand on computer capacities, so simulation runs slowly, that is why it cannot be used in real-time applications. To eliminate the mentioned disadvantages, keeping the main cell functions, we effectuated a symbolic model, which is appropriate to describe the information and signal-streaming in arbitrary cell network. This model works perfect for large neuron networks, so it can be used for image processing. In this paper we analyze that synthetic description. During the testing of the symbolic model we examine basic problems of image processing, such as preprocessing, filtering, classifying, and the ways how biologic systems solve these. Beyond presenting results, we made an effort to obtain biologic-based conclusions, which can help solving special problems of machine vision and numerous relevant areas.
  • Cím:
    Building an Agent-Based Manufacturing Model
    Írta:
    Miklós Szegedi
    Oldalak száma:
    123-133
    This paper contains the results of a recent survey on agent based economic models. Agent based approach tries to model systems from the bottom-up without the exact knowledge of how the whole system should work. Agents are the atomic bricks having individual parameters. The model defines the rules of how these atomic elements interact with each other. The survey is intended to check the basic features of such models and whether they can be taught to show realistic behavior. All simulations were based on a market model. The first caseworks dealt with a simple market where producer and consumer agents traded together. More complex models were created with the attachment of more of these markets. The final model made a loop of goods and showed that a realistic economic system can be simulated based on the agent approach that is capable of growth.