• KIEE International Transactions on Power Engineering
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• 제3A권2호
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• pp.93-99
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• 2003

This paper deals with the development and testing of a large-scale, realtime digital power system simulator for the Korean Electric Power Corporation. The KEPS Simulation Center is located at KEPCO's research center (KEPRI) in Taejon, South Korea and has been operated since September 2001. The KEPS Simulation Center includes a wide range of off line power system simulation and analysis tools, as well as an advanced realtime digital simulator for the study of large scale AC and DC system performance. Because the application scope of the KEPS realtime simulator is broad and because the network models being considered are significantly larger and more complex than in traditional realtime simulator applications, many developments and tests have been required during the course of the project. In this paper, the authors describe some of these developments and present results from various benchmark tests that have been performed.

• 산업공학
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• 제16권2호
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• pp.258-267
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• 2003

Recently, virtual reality technologies have been rapidly developed and realtime virtual simulation methods have been extensively employed for several application areas such as game, sports, manufacturing, military, and so on. A 3D database in realtime virtual simulation plays a key role because it makes users feel reality in virtual space. In a application view of 3D database, a systematic construction approach is required to reduce its construction time and increase its quality. However, many researches have been mostly focused on realtime graphic issues and its key technologies. In virtual simulation of transportation equipments, this paper proposes a systematic construction process of 3D database consisting of four stages as follows: 1) determine the activity space of a equipment, 2) collect data related to 3D database construction, 3) make a 3-dimensional modeling strategy, and 4) generate and evaluate a 3D model. This paper also introduces a new procedure of 3D environment modeling, which summarizes and expands our modeling experiences, to be used as a modeling guide.

• 한국해양공학회지
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• 제11권3호
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• pp.163-169
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• 1997

The simulation of target-scattered echo with the moving sonar platform and target in 3-dimensional ocean environment is essential to validate and evaluate the performance of a sonar system. This paper presents the improved target signal simulation on the basis of the highlight(HL) model and its realtime algorithm. In order to simulate the scattering highlight, the highlight is represented as a directional scatterer. The realtime generation algorithm of the target signal is realized by use of DSP chip, TMS320C40, where the 40 channels are equally separated to form a parallel processing task in 4 processors. The presented realtime-version of target signal simulation can be used as a target signal simulator in the development of ACM(Acoustic Counter Measure) and advanced sonar signal processing techniques.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.261-264
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• 1997

In case of high speed and high mobility multibody tracked vehicle, it is hard to develop the realtime simulation model for track tension control because of the hundreds of highly nonlinear equations. In order to design more trustworthy realtime simulator for track tension control, it is necessary to use off-line tracked vehicle model. In this study, a step by step procedure is presented to develop realtime simulation model based on off-line tracked vehicle model. Simulation results show that modified off-line multibody tracked vehicle model can be used for real time simulation to control the track tension.

• 한국통신학회논문지
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• 제25권9A호
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• pp.1340-1347
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• 2000

The international mobile telecommunication-2000(IMT-2000) system can support not only the non-realtime multimedia traffic such as data such as data image but also the realtime multimedia traffic such as voice, video. In the paper we propose multicode allocation and handoff schemes for efficient transmission of realtime and non-realtime data in cdma2000. In those schemes the bandwidth of target cell is reserved based on moving direction of mobiles to support QoS of realtime multimedia data and the reserved bandwidths is used by the non-realtime mobiles of the target cell until the mobiles want to perform hadoff. Our framework is able to guarantee QoS continuity of realtime multimedia data and carries the maximum number of subscriber. System performance is evaluated and compared with conventional scheme considering transmission delay channel utilization and blocking probability by computer simulation.

• 한국게임학회 논문지
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• 제9권4호
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• pp.97-106
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• 2009

본 논문은 적응적 메쉬 구조를 이용하여 가상 종이 객체를 실시간에 시뮬레이션 하는 방법을 제안한다. 제안된 기법은 임의의 삼각 메쉬에 적용될 수 있으며, 안정적인 수치 적분과 변형 기반 메쉬 세분화를 이용하여 효율적으로 종이 표면의 주름과 구김을 생성한다. 종이 객체의 구겨짐을 사실적으로 표현하기 위하여 부러지는 스프링을 가진 적응적 메쉬 구조를 사용한다. 적응적 구조가 지속적으로 질점을 삽입 혹은 삭제하기 때문에, 질량과 운동량의 보존이 고려되어야만 사실적인 종이 시뮬레이션이 가능하다. 제안된 기법은 실시간 환경에서 종이와 같이 얇은 쉘 구조의 사실적인 애니메이션을 생성한다.

• 항공우주기술
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• 제3권2호
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• pp.238-247
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• 2004

실시간 시뮬레이션 및 HILS(Hardware In the Loop Simulation)는 항공기 설계 및 개발에 있어서 개발기간의 단축과 비용절감 측면에서 필수적이며 컴퓨팅 기술의 발달로 그 중요성이 더욱 부각되고 있다. 복잡한 운동모델과 실시간 시뮬레이션에 대한 요구사항을 충족시키기 위하여 분산처리에 의한 시뮬레이션이 요구되며 실시간 컴퓨터 환경 내에서 시뮬레이션 소프트웨어를 개발해야 하므로 개발 및 디버그, 유지보수가 매우 어렵다. 특히 실시간, 무 교착상태의 고성능 분산코드를 작성하는 경우는 더욱 그러하다. 본 연구에서 구축하는 회전익기 HILS 환경은 이러한 어려움을 상당부분 처리함으로써 사용자가 직접 코드를 손대지 않고 HILS 및 시뮬레이션을 수행할 수 있도록 상용화된 부품과 개발된 최신 툴을 이용하여 구성하였다. Matlab/Simulink 환경에서 개발된 회전익기 비행시뮬레이션 소프트웨어를 기준으로 하여 HILS 환경 및 MILS(Man In the Loop) 환경이 추가되어 조종사의 직접 입력에 대한 반응을 실제 하드웨어에 피드백 하는 MILS-HILS 통합 환경을 구축하였다. 개발기간의 단축 및 유지보수의 편의를 위하여 RT-Lab을 사용하여 실시간 코드를 생성하고 타켓컴퓨터에 다운로드 하는 방식으로 실시간 시뮬레이션이 가능하다.

• 한국공작기계학회논문집
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• 제14권5호
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• pp.55-61
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• 2005

In this paper, we propose the visual simulation system for virtual reality motion rider system. The visual simulation system can apply verity virtual reality system. This paper deals with programs on 3D automatic creation of terrain, road design, and a realtime rendering program for the virtual reality system. For the 3D automatic creation of terrain, DEM data and rectangular grid method are applied. We can make two different road object with the road design program. One of them includes road definition, and the other is obtained by using 'NURBS curve.' Visual simulation is consisted by additional modeling and real-time rendering. We can apply the programs made in this way to visual system of driving simulator.

• 한국통신학회논문지
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• 제28권9A호
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• pp.736-745
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• 2003

본 논문은 CDMA/TDD 시스템에서, 높은 전송률과 일정한 QoS를 갖는 실시간 클래스의 무선 자원 할당에 대한 방법론을 제시한다. 실시간 클래스와 비실시간 클래스를 제어하기 위하여, 예약 액세스 기법과 우선 순위 기법이 각각 제안된다. 또한 각 셀 링크간 간섭에 의한 성능 감소를 예방하기 위하여 슬롯 할당 기법을 제안한다. 제시된 방안들을 통하여 실시간 클래스의 연속성을 보장하고 비실시간 가입자를 최대로 수용할 수 있다. 다중 셀 환경과 멀티미디어 서비스 모델을 가정하여, 제안된 기법의 성능이 전송 지연, 채널 이용률 그리고 데이터 손실 등을 근거로 하여 평가된다. 시뮬레이션 결과는 상당한 성능 향상이 있음을 보인다.

• 한국멀티미디어학회논문지
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• 제17권9호
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• pp.1104-1114
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• 2014

In large-scale crowd simulations, it is very important for the decision-making system of manipulating interactive behaviors to minimize the computational cost for controlling realistic behaviors such as collision avoidance. In this paper, we propose a large-scale realtime crowd simulation method using the affordance and navigation potential fields such as attractive and repulsive forces of electromagnetic fields. In particular, the model that we propose locally handles the realistic interactions between agents, and thus radically reduces the cost of expensive computation on interactions which has been the most problematic in crowd simulation. Our method is widely applicable to the expression and analysis of various crowd behaviors that are needed in behavior control in computer games, crowd scenes in movies, emergent behaviors of evacuation, etc.