• Title, Summary, Keyword: Dynamic Simulation

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The Process Simulation of Entrained Flow Coal Gasification in Dynamic State for 300MW IGCC (300MW급 IGCC를 위한 건식 분류층 석탄 가스화 공정의 동적 상태 모사)

  • Kim, Mi-Yeong;Joo, Yong-Jin;Choi, In-Kyu;Lee, Joong-Won
    • Transactions of the Korean hydrogen and new energy society
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    • v.21 no.5
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    • pp.460-469
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    • 2010
  • To develop coal gasfication system, many studies have been actively conducted to describe the simulation of steady state. Now, it is necessary to study the gasification system not only in steady state but also in dynamic state to elucidate abnormal condition such as start-up, shut-down, disturbance, and develop control logic. In this study, a model was proposed with process simulation in dynamic state being conducted using a chemical process simulation tool, where a heat and mass transfer model in the gasifier is incorporated, The proposed model was verified by comparison of the results of the simulation with those available from NETL (National Energy Technology Laboratory) report under steady state condition. The simulation results were that the coal gas efficiency was 80.7%, gas thermal efficiency was 95.4%, which indicated the error was under 1 %. Also, the compositions of syngas were similar to those of the NETL report. Controlled variables of the proposed model was verified by increasing oxygen flow rate to gasifier in order to validate the dynamic state of the system. As a result, trends of major process variables were resonable when oxygen flow rate increased by 5% from the steady state value. Coal flow rate to gasifier and quench gas flow rate were increased, and flow rate of liquid slag was also increased. The proposed model in this study is able to be used for the prediction of gasification of various coals and dynamic analysis of coal gasification.

Reinforcement Learning Approach to Agents Dynamic Positioning in Robot Soccer Simulation Games

  • Kwon, Ki-Duk;Kim, In-Cheol
    • Proceedings of the Korea Society for Simulation Conference
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    • pp.321-324
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    • 2001
  • The robot soccer simulation game is a dynamic multi-agent environment. In this paper we suggest a new reinforcement learning approach to each agent's dynamic positioning in such dynamic environment. Reinforcement Beaming is the machine learning in which an agent learns from indirect, delayed reward an optimal policy to choose sequences of actions that produce the greatest cumulative reward. Therefore the reinforcement loaming is different from supervised teaming in the sense that there is no presentation of input-output pairs as training examples. Furthermore, model-free reinforcement loaming algorithms like Q-learning do not require defining or loaming any models of the surrounding environment. Nevertheless it can learn the optimal policy if the agent can visit every state-action pair infinitely. However, the biggest problem of monolithic reinforcement learning is that its straightforward applications do not successfully scale up to more complex environments due to the intractable large space of states. In order to address this problem, we suggest Adaptive Mediation-based Modular Q-Learning(AMMQL) as an improvement of the existing Modular Q-Learning(MQL). While simple modular Q-learning combines the results from each learning module in a fixed way, AMMQL combines them in a more flexible way by assigning different weight to each module according to its contribution to rewards. Therefore in addition to resolving the problem of large state space effectively, AMMQL can show higher adaptability to environmental changes than pure MQL. This paper introduces the concept of AMMQL and presents details of its application into dynamic positioning of robot soccer agents.

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Comparison between test and simulation results of vibration for Korean High Speed Train (한국형 고속전철의 주행시험과 이론해석 결과의 비교분석)

  • 박찬경;김석원;김영국;목진용
    • Proceedings of the KSR Conference
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    • pp.210-215
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    • 2003
  • Korean High Speed Train (KHST) has been tested on high speed line in JungBu site since it was developed in 2002. The KHST figured 7 cars was modeled for dynamic simulation with Vampire program. and the data acquisition system was used to test successfully the on-line test for proving the dynamic performance of KHST. The comparison between test and simulation results for dynamic behavior of KHST was tried in this paper and it was very difficult because the environmental conditions and running conditions have an effect on the test results and these conditions are unable to be modeled for dynamic analysis. Also the parameters for data acquisition system for test are usually not same to simulation conditions. Therefor, in this paper the acceleration data after filtering with low pass filter below 1Hz were used to compare between test and simulation results because the low frequency range is useful to evaluate the dynamic performance for railway vehicle system, so as steady state curving acceleration. The results show that both are similar in low frequency range.

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Analysis on Dynamic Characteristics for Moving-Magnet Linear Oscillatory Actuator with Cylindrical Halbach Array (원통형 Halbach 배열 영구자석을 갖는 가동자석형 LOA의 동특성 해석)

  • Jang, Seok-Myeong;Choi, Jang-Young;Cho, Han-Wook
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.54 no.11
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    • pp.533-539
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    • 2005
  • In the previous work, we performed the analysis of a tubular type moving-magnet linear oscillatory actuator (LOA) with cylindrical Halbach array by using 2-d analytical formulas and confirmed validity of analytical results by comparison of those with both finite element (FE) computation and experimental results. This paper deals with the dynamic characteristic analysis of the moving-magnet LOA with cylindrical Halbach array. Control parameters such as the thrust constant, the back-emf constant, resistance and inductance are obtained from both analytical and experimental results. And then, the dynamic simulation algorithm is established by the state and output equation obtained from voltage and motion equation. Finally, for various values of frequency, the dynamic simulation and experimental results for the characteristics of the voltage, current and displacement of moving-magnet LOA are presented. The simulation results are validated extensively by experiments. The experimental and simulation results for the variation of stroke according to control voltage are also presented for various values of frequency.

Solution verification procedures for modeling and simulation of fully coupled porous media: static and dynamic behavior

  • Tasiopoulou, Panagiota;Taiebat, Mahdi;Tafazzoli, Nima;Jeremic, Boris
    • Coupled systems mechanics
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    • v.4 no.1
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    • pp.67-98
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    • 2015
  • Numerical prediction of dynamic behavior of fully coupled saturated porous media is of great importance in many engineering problems. Specifically, static and dynamic response of soils - porous media with pores filled with fluid, such as air, water, etc. - can only be modeled properly using fully coupled approaches. Modeling and simulation of static and dynamic behavior of soils require significant Verification and Validation (V&V) procedures in order to build credibility and increase confidence in numerical results. By definition, Verification is essentially a mathematics issue and it provides evidence that the model is solved correctly, while Validation, being a physics issue, provides evidence that the right model is solved. This paper focuses on Verification procedure for fully coupled modeling and simulation of porous media. Therefore, a complete Solution Verification suite has been developed consisting of analytical solutions for both static and dynamic problems of porous media, in time domain. Verification for fully coupled modeling and simulation of porous media has been performed through comparison of the numerical solutions with the analytical ones. Modeling and simulation is based on the so called, u-p-U formulation. Of particular interest are numerical dispersion effects which determine the level of numerical accuracy. These effects are investigated in detail, in an effort to suggest a compromise between numerical error and computational cost.

Automobile Dynamic Simulation using CAD/CAE (CAD/CAE 기법을 이용한 자동차 동역학적 시뮬레이션)

  • No, Chang-Su
    • 한국기계연구소 소보
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    • pp.147-152
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    • 1988
  • The dynamic simulation for automobile running on bumpy road is introduced. The modeling method that is a very close approximation to automobile is presented. Because the output printed at every integration time step is lots of amount, to save the time of interpretation of dynamic response, the ouptput data are interactively processed by PLOT88, also a configuration of automobile is generated by animated graphic displays using PADL and APPLICON.

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Design Characteristics and Dynamic Simulation of High Speed LSRM (고속 LSRM의 설계 특성 및 동특성 시뮬레이션)

  • Sung, So-Young;Sung, Ho-Kyung;Park, Ji-Hoon;Jang, Seok-Myeong
    • Proceedings of the KIEE Conference
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    • pp.1155-1156
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    • 2007
  • This paper deals with dynamic simulation and design characteristic of Linear Switched Reluctance Motor (LSRM). First, we derived design factor from pole arc ratio of stator and mover. Second, we decided design parameter from design factor using time constant. Finally, analyze dynamic characteristics for LSRM using simulation.

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A Pilot Study of Moving Loads Simulation Techniques (이동하중 재현 시험 기법에 대한 선행 연구)

  • Kim, Hyun-Min;KIm, Sung-Il
    • Proceedings of the KSR Conference
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    • pp.1492-1499
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    • 2010
  • This paper is intended as an development of moving load simulation techniques. The concern with dynamic problem of railway bridge caused by the moving train loads has been growing. Over the past few years, several studies have been made on dynamic stability of railway bridge analytically. But very few attempts have been made at experimental research. From the dynamic stability view point, the moving train loads simulation test is revolutionary idea. It can be replace restrictive filed test with new laboratory test. This study investigates minimum specifications of hardware and basic parameters. it is used 39m girder and 4 actuators for experimental verification.

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Computer Simulation Program for Central Limit Theorem - Dynamic MS Excel Program -

  • Choi, Hyun-Seok;Kim, Tae-Yoon
    • Journal of the Korean Data and Information Science Society
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    • v.16 no.2
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    • pp.359-369
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    • 2005
  • Central limit theorem is known as one of the most important limit theorem in statistics and probability. This paper provides a dynamic MS Excel program that demonstrates computer simulation of various types of central limit theorems. Our result will be of great use for better understanding of central limit theorems.

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Computer Simulation of Dynamic Response of Vehicles on Rough Ground (노면가진에 의한 차체의 동적거동에 관한 연구)

  • 조선휘;이건우;박종근;조병관;송성재;한규진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.3
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    • pp.419-425
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    • 1988
  • It would be very useful if the dynamic response of a vehicle over rough ground could be predicted at the early design stage. This became more promising with the recent progress in computer hardware and software technologies. In this study, a model of a passenger car has been developed for the analysis of its dynamic response. This model can be easily used for the other passenger cars with little modification. This passenger car was modeled to be composed of lumped masses, rigid bodies, and the suspension systems with nonlinear properties. Even though a commercial dynamic simulation program, ADAMS, was used in this study, the developed model is valid for any other simulation program. Finally, the validity of the developed model and the analysis result was verified by an experiment.