• Journal of Power System Engineering
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• v.7 no.4
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• pp.38-43
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• 2003

This paper proposes an optimum design problem of structural and control systems. taking a 3-D truss structure as an example. The structure is supposed to be subjected to initial static loads and time-varying disturbances. The structure is controlled by a state feedback $H_{\infty}$ controller to suppress the effect of the disturbances. The design variables are the cross sectional areas of truss members. The structural objective function is the structural weight. As the control objective, we consider two types of performance indices. The first function represents the effect of the initial loads. The second one is the norm of the feedback gain. These objective functions are in conflict with each other. Then, first, two control objective functions are transformed into one control objective by the weighting method. Next, the structural objective is treated as the constraint. By introducing the second control objective which considers the magnitude of the feedback gain, we can per limn the design which is robust in modeling errors.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.07a
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• pp.293-294
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• 2013

다양한 생물체의 행동 원리를 이용하여 모델링한 알고리즘을 생체모방 알고리즘(Biologically Inspired Algorithm)이라고 한다. 본 논문에서는 생체모방 알고리즘 중 동물 집단의 행동을 모델링한 플로킹 알고리즘(Flocking Algorithm)을 이용한 집단 게임 캐릭터의 길찾기 방법을 제안한다. 플로킹 알고리즘의 조타행동은 크게 분리(Separation), 정렬(Alignment), 응집(Cohesion), 회피(Avoidance)로 구성되어 있다. 게임에서의 기존 플로킹 알고리즘은 주로 여러 개의 몬스터나 NPC 들로 구성된 몇 개의 그룹 단위로 독자적인 집단 행동을 하는 경우에 적합하다. 그러나, 게임플레이어가 제어하는 캐릭터가 많은 경우, 기존 알고리즘은 플레이어가 선택한 캐릭터 그룹을 목표지점으로 이동하는 방법으로 적합하지 않다. 따라서 본 논문에서는 게임 플레이어가 제어하는 집단 게임캐릭터의 목표 지점까지의 길찾기를 위한 수정된 정렬 조타행동 알고리즘을 제안한다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.117-120
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• 2003

A method for PID controller tuning based on process models for unstable processes was introduced. The optimal. proportional and derivative gains of the AMBs were determined by the tuning method and utilized for the chatter stability analysis in order to search for the chatter-free cutting region. The stability analysis results showed that the optimal gains give wider chatter-free cutting region, and as a result the proposed tuning method was confirmed to be an effective tuning method for determining the optimal gains of the AMBs.

• Proceedings of the Korea Contents Association Conference
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• 2005.05a
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• pp.55-58
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• 2005

The existing game development way is adopting a direct engine design way. It was hard to learn game development, but it can learn the process that uses a script an abstraction. And it improves productivity and convenience anger because modeling does not do an engine directly and reduce a development cost and can solve a problem of a development human power security. The representative characteristic of this paper was able to change a development environment into an abstract script language with modeling having done an engine in the existing game development environment directly.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.1
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• pp.124-134
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• 2000

The power wteering system for automobiles is becoming core popular for supporting steering efforts of the drivers, especially for a parking lot maneuver. Though hydraulic power steering has been widely used for a long time, the efficiency of that is not high enough. The motor driven power steering system can solve the problems associated with the hydraulic power steering system. In this study, dynamic model and control algorithm of the ball screw type of MDPS systenem have been derived and analysed by using the method of discrete modeling technology. To improve steering feel and power steering characteristics, the additional scheme is proposed to the conventional power boosting control algorithm. Through simulations, control gain effects to the steering angle gain in the frequency domain were verified. The steering returnability and steering torque phase lag in on-center handing test were performed also.

• Journal of Auto-vehicle Safety Association
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• v.9 no.2
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• pp.26-32
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• 2017

This paper presents the lateral stability criteria for integrated chassis control. To determine the intervention timing of chassis control system, the lateral stability criteria is needed. The proposed lateral stability criteria is based on velocity-yawrate gain domain to determine whether vehicle is stable. If the yawrate gain violates the proposed criteria, the stability of the vehicle is considered as unstable. Characteristic velocity and critical velocity are employed to distinguish lateral stability criteria. The inside of the two boundaries is stable and the outside is unstable. If yawrate gain of vehicle violates the lateral stability criteria, the chassis control begin to intervene. To validate the lateral stability criteria, both computer simulations and vehicle test are conducted with respect to circular turn scenario. The proposed lateral stability criteria makes it possible to reduce intervention of chassis control system.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.492-493
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• 2012

본 논문은 계통 연계형 인버터에서 FFT를 이용한 선택적 고조파 제거 알고리즘을 제안한다. 제안하는 FFT 기법은 별도의 게인 튜닝 없이 직접제어가 가능하며, 노이즈에 강인한 특징을 가진다. 기본적으로 신재생 에너지원을 통해 계통 연계 인버터는 계통에 전력 공급할 뿐만 아니라 계통 전원 전류에 나타나는 저차 고조파를 선택적으로 제거할 수 있다. 제안된 제어 전략의 타당성을 실험을 통하여 검증하였다.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1996.04b
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• pp.99-105
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• 1996

공기 베어링은 마찰과 열 발생이 적고 회전 정밀도가 우수하여 고속 회전하는 축을 지지하는 용도로 많이 사용되고 있다. 그러나 공기 베어링도 유체 베어링이라면 어느것이나 갖는 Whirl 불안정성이라는 치명적인 결점을 갖는데 현재 이것의 발생 시점이 공기 베어링을 사용하는 시스켐에 있어서 고속화의 한계로 되어있다. 본 논문에서는 불안정성의 원인이 되는 동압 발생을 억제할 수 있는 방법으로 베어링의 위치가 축의 위치에 대해 일정한 각도 지연을 갖도록 제어되는 것을 제안하고 여러 각도지연 크기와 제어게인에 따른 안정특성을 이론 해석을 통해 조사하였다.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.749-755
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• 2009

BCI (Brain-Computer Interface) is a way to control computer by using the human brain waves. As the hardware using brain wave technologies has developed, former expensive and big sized brain wave measuring devices have recently become much smaller and cheaper in their prices, making it possible for the individuals to buy them. This predicts them to be applied in various fields of multimedia industry. This thesis is to give an insight into whether the BCI device can be used as a new gaming device approaching it in a game designing point of view. At first, we propose game play elements that can effectively utilizing the BCI devices and produce a game prototype adopting the BCI device based on such game play elements. Next, we verify it with statistical data analysis to show that the prototype adopting the BCI device gives more clear and efficient controls in its game play than a game of only adopting keyboard & mouse devices. The results will give a guideline for effective game design methodology for making BCI based games.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.135-143
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• 2015

A Multiplayer Online Game(MOG) is a game capable of supporting hundreds or thousands of players and is mostly played using the Internet. P2P(peer-to-peer) architectures for MOGs can potentially achieve high scalability, low cost, and good performance. The basic idea of many P2P-based games is to distribute the game state among peers and along with it processing, network, and storage tasks. In a primary-copy based replication scheme where any update to the object has to be first performed on the primary copy, this means distributing primary copies of objects among peers. Most multiplayer games use a primary-copy model in order to provide strong consistency control over an object. Games consist of various types of actions that have different levels of sensitivity and can be categorized according to their consistency requirements. With the appropriate consistency level of each action type within a game, this paper allows developers to choose the right trade-off between performance and consistency. The performance for P2P game architecture with the primary-copy model is evaluated through simulation experiments and analysis.