• Title/Summary/Keyword: and system dynamics

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A Study on the Heterogeneity in Multi-player VR Games : focused on (멀티플레이어 가상현실 게임에 나타난 비균질성 연구 : <더 플레이룸 VR>을 중심으로)

  • Park, Eun-Kyung;Nam, Yang-Hee
    • Journal of Korea Game Society
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    • v.16 no.6
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    • pp.151-162
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    • 2016
  • The purpose of this paper is to identify the significance of heterogeneity in multi-player VR games. Heterogeneity is a concept of multi-player mode that a game uses the immersive VR and non-immersive system at the same time. As immersive VR device has become more commercial, multi-player VR games try to use heterogeneity strategically. is the best example to explain a new phenomenon, so this paper analyses by using a revised and reinforced MDA framework. As a result, we can find heterogeneity concept not only in the separation of player's interface, but also in the division of play patterns and experiences within a game itself.

Design of Path Tracking Controller for Underactuated Autonomous Underwater Vehicle Using Approach Angle Concept (접근 각도 개념을 이용한 과소 작동기 무인 잠수정의 경로 추적 제어기 설계)

  • Kim, Kyoung-Joo;Choi, Yoon-Ho;Park, Jin-Bae
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.2
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    • pp.225-231
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    • 2012
  • In this paper, we propose a method for designing the path tracking controller using an approach angle concept for an underactuated autonomous underwater vehicle (AUV). The AUV is controlled by the surge speed and yaw rate: there is no side thruster. To solve this underactuated AUV problem in the path tracking, we introduce an approach angle concept which makes the AUV converge to the reference path. And we design the path tracking controller using the proposed approach angle. To design the path tracking controller, we obtain the new vehicle's error dynamics in the body-fixed frame, and then design the path tracking controller based on Lypunov direct method. Finally, some simulation results demonstrate the effectiveness of the proposed controller.

CFD Analysis of Axial Flow Cyclone Separator for Subway Station HVAC System (지하역사 공기조화기에 적용 가능한 미세먼지 제거용 사이클론의 수치해석적 연구)

  • Kim, Jin-Kwan;Kim, Ho-Joong;Lee, Myung-Jun;Kim, Tae-Sung;Kwon, Soon-Bark
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.546-550
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    • 2008
  • In this study, 3-dimensional Computational Fluid Dynamics (CFD) analysis was induced to simulate air flow and particle motion in the axial flow cyclone separator. The commercialized CFD code FLUENT was used to visualize pressure drop and particle collection efficiency inside the cyclone. We simulated 4 cyclone models with different shape of vane, such as turning angle or shape of cross section. For the air flow simulation, we calculated the flow field using standard ${\kappa}-{\varepsilon}$ turbulence viscous model. Each model was simulated with different inlet or outlet boundary conditions. Our major concern for the flow filed simulation was pressure drop across the cyclone. For the particle trajectory simulation, we adopted Euler-Lagrangian approach to track particle motion from inlet to outlet of the cyclone. Particle collection efficiencies of various conditions are calculated by number based collection efficiency. The result showed that the rotation angle of the vane plays major roll to the pressure drop. But the smaller rotation angle of vane causes particle collection efficiency difference with different inlet position.

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Effect of Gas Channel/Rib Width in Solid Oxide Fuel Cells (고체산화물 연료전지에서 가스채널/리브 폭의 영향에 관한 연구)

  • Jeon, Dong Hyup;Shin, Dong-Ryul;Ryu, Kwang-Hyun;Song, Rak-Hyun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.41 no.2
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    • pp.109-115
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    • 2017
  • Using the computational fluid dynamics (CFD) technique, we performed a numerical simulation in anodesupported solid oxide fuel cell (SOFC). The effect of gas channel/rib width on the cell performance and temperature uniformity was investigated in planar type SOFC. The open source CFD toolbox, OpenFOAM, was used as a numerical analysis tool. As a result, the effect of gas channel/rib width on the cell performance and temperature uniformity was not significant if the oxygen depletion is not occurring. On the other hand, the usage of a wide rib and operation at high current density may lead to performance degradation due to oxygen depletion.

Single Step Response Based Method for the Simple Identification of Wiener-type Nonlinear Process (단일 계단 응답에 근거한 Wiener형 비선형 공정의 간편한 모델 확인 방법)

  • Sanghun Lim;Jea Pil Heo;Su Whan Sung;Jietae Lee;Friedrich Y. Lee
    • Korean Chemical Engineering Research
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    • v.61 no.1
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    • pp.89-96
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    • 2023
  • The Wiener-type nonlinear model where a static nonlinear block follows a dynamic linear block is widely used to describe the dynamics of chemical processes. A long process excitation step is typically needed to identify this Wiener-type nonlinear model with two blocks. In order to cope with this disadvantage, an identification method for the Wiener-type nonlinear model that uses only a single-step response is proposed here. The proposed method estimates the response of the dynamic linear sub-block from the initial part of the step response, and then the static nonlinear sub-block is identified. Because the only single-step response is used to identify the Wiener-type nonlinear model, there is great benefit in time and cost for obtaining process response. The performance of the proposed identification method with the single-step response is verified through a representative Wiener-type nonlinear process, a pH titration process, and a liquid level system.

Numerical Modelling Techniques of VPMM for Manta Type UUV (만타형 UUV의 VPMM 전산해석기법 개발)

  • Sang-Eui Lee
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2023.05a
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    • pp.151-151
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    • 2023
  • An accurate prediction of the hydrodynamic maneuvering darivatives is essential to desing a robust control system of a UUV(unmanned underwater vehicle). Typically, these derivatives were estimated by either the towing tank experiment or semi-empirical methods. With the enhancement of high performance computing capacity, a numerical analysis using computational fluid dynamics has reach the level of experiment. Therefore, the aims of the present research are to numerically develop a computational model for the vertical planar motion mechanism of a UUV and to estimate the hydrodynamics loads in 6-DOF. The target structure of the present study was manta type UUV (12meter length). The numerical model was developed in 1/ 6 model scale. Numerical results were compared with the results of the towing tank experiment for validation. In the present study, a commercial RANS-based viscous solver STARCCM+ (ver 17.06) was used.

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Numerical Study on Aerodynamic Lift on Windshield Wiper of High-Speed Passenger Vehicles (자동차 고속 주행시 와이퍼 부상현상에 대한 수치해석 연구)

  • Lee, Seung-Ho;Lee, Sung-Won;Hur, Nahm-Keon;Choi, Woo-Nyoung;Sul, Jin-Hwan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.4
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    • pp.345-352
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    • 2011
  • In the present study, a three-dimensional CFD simulation on aerodynamic lift acting on windshield wiper blades was performed to improve the wiping performance of a vehicle moving at a high speed. To predict the reliable flow characteristics around the windshield wiper system, the computational domain included the full vehicle model with detailed geometry of wiper blades in the wind tunnel. From the numerical results, the drag and lift coefficients of wiper blade were obtained for the performance of windshield wiper. With this aerodynamic characteristics of windshield wiper, the effects of wiping angles and hood tip angle on the wiping performance of the windshield wiper were evaluated.

Real Time Textile Animation Using Fuzzy Inference (퍼지추론을 적용한 직물 애니메이션)

  • Hwang, Seon-Min;Song, Bok-Hee;Yun, Han-Kyung
    • The Journal of the Korea Contents Association
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    • v.11 no.9
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    • pp.1-8
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    • 2011
  • A fuzzy inference technique for real-time textile animation without integration at textile model based Mass-Spring model is introduced. Until now many techniques have used the Mass-Spring model to describe elastically deformable objects like textile. A textile object is able to represent as a deformable surface composed of spring and masses, the movement of textile surface which is analysed through the numerical integration by the fundamental law of dynamics such as Hooke's law. However, the integration methods have 'instability problems' if the explicit Euler's method is applied or 'large amounts of calculation' if the implicit Euler's method is applied. A simple and fast animation technique for Mass-Spring model of a textile with fuzzy inference is proposed. The stabilized simulation result is obtained the state of each mass-point in real-time for the n of mass-points by a relatively simple calculation.

xPMP : UML-based High-Level Modeling of Policy-Driven Management Applications (xPMP - 정책 기반 관리 어플리케이션의 상위 단계 모델링)

  • Tran, Doan Thanh;Choi, Eun-Mi
    • Journal of the Korea Society for Simulation
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    • v.17 no.4
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    • pp.209-218
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    • 2008
  • The Unified Modeling Language becomes popular to specify, visualize, construct, and document software-intensive systems, especially in supporting the design phase of software engineering. Most of designs in UML have focused on firm designing of software system structure. Recently, some researches have raised additional demands in many emerging complex software systems, such as aspect-oriented design. In this paper, we work on the dynamic aspect of policy-driven architecture. We present a UML-based high-level modeling of policy-driven management which is applicable in various application domains. In order to manage a number of activities of applications, dynamics and flexibility should be supported with policies consistently on different resources in the same context. Thus, a methodology of meta-modeling to represent dynamic aspects of policy-driven architecture is studied. Based on our methodology, we could achieve meta-modeling to develop a number of policy-driven management applications.

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A Study on Labor Market Policy according Wage and Labor time in the Korea (국내 임금과 노동시간의 추이를 통한 노동시장정책 방향에 관한 연구)

  • Jang, Yu-Mi
    • Journal of Convergence Society for SMB
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    • v.3 no.1
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    • pp.7-13
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    • 2013
  • It will prove that with a more plausible specification of the relationship between income and the value of leisure, we can develop a more accurate model of the labor market without necessarily losing the primary merit of the received model. Moreover, with an improved understanding of labor market dynamic we can see that progressive era labor market legislation, designed to mitigate the effects of bargaining power inequality in low wage labor markets, was in fact based upon sensible economic foundations. The results of this study as follow; These low-wage dynamics present an example of a positive feedback system or "vicious circle" at work in the economy. With the revised labor supply schedule presented above, the market dynamic of the low wage sector push the wage away from the range that is consistent with a self-regulating market.

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