• 한국시뮬레이션학회논문지
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• 제26권3호
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• pp.23-34
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• 2017

본 연구는 복수 품목을 정비하는 단일 정비부대의 정비 프로세스를 시뮬레이션으로 모델링하였다. 이를 통해 정비능력을 공유한 정비창이 최적 비용으로 구성품 가동률과 목표 가동율 등을 달성하는지를 분석할 수 있다. 구성품 가동률과 정비시간 등을 핵심 성과지표로 하여 육군 항공기 정비단 엔진 정비프로세스에 대한 시뮬레이션 모델을 구성하고 실증연구를 하였다. 영향요소의 식별을 위해 NOLH 실험설계법을 적용하여, 33가지 시나리오를 구성하고 다중회귀분석을 수행하였다. 이 비용분석 연구를 통해 정비 프로세스의 개선사항을 식별할 수 있었다. 본 연구는 시뮬레이션을 통해 복수품목을 정비하는 단일 정비부대의 비용대 효과 분석 모형을 제공했다는데 의의가 있다.

• Transactions on Control, Automation and Systems Engineering
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• 제4권2호
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• pp.114-123
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• 2002

Called VISTA (Variable-stability In-flight Simulator Test Aircraft), the one-of-a-kind NF-l6D has a simulation system that can mimic several aircraft. Though housed in an F-l6 Fighting Falcon airframe, VISTA can also act like the F-15 Eagle or the Navy's F-14 Tomcat. More importantly, such flexibility allows for improved training and consolidation of some sorties. Consequently USAF Test Pilot School students will have an opportunity to learn how to test future integrated cockpits. In this paper we will use the multiple model adaptive estimation (MMAE) and the multiple model adaptive controller (MMAC) techniques to model the aircraft's flight control system containing the longitudinal and lateral-directional axes. Single and dual actuator and sensor failures will also be included in the simulation. White Gaussian noise will be included to simulate the effects of atmospheric disturbances.

• 산업공학
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• 제7권2호
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• pp.87-97
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• 1994

Many vehicle routing methods have been suggested, which minimize the routing distances of vehicles to reduce the total transportation cost. But the more considerations the method takes, the higher complexites are involved in a large number of practical situations. The purpose of this paper is to develop a vehicle distribution planning system using heuristic algorithms and simulation techniques for home electronics companies. The vehicle distribution planning system developed by this study involves such complicated and stochastic conditions as one depot, multiple nodes(demand points), multiple vehicle types, multiple order items, and other many restrictions for operating vehicles. The proposed system is compared with the nearest neighbor method of the current system in terms of total logistics cost and driving time. This heuristics algorithm and simulation based distribution planning system is efficient in computational complexity, and give improved solutions with respect to the cost as well as the time. This method constructs a route with a minimum number of vehicles for a given demand.

• Communications for Statistical Applications and Methods
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• 제16권3호
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• pp.487-493
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• 2009

We consider a multiple defaultable zero coupon bond. Assuming defaults occur according to a marked point process, we explain how to estimate the time-t discounted price of zero coupon bond by simulation. For the special case of a given specific random face value, we show that the real probability measure is the risk neutral probability measure. In this case the time-t discounted conditional price can be obtained by observing a single sample path upto the time t in the real world. Furthermore the time-t discounted price can be estimated by observing real situations or by simulation under the real probability measure.

• 한국국방경영분석학회지
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• 제22권2호
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• pp.182-199
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• 1996

Many vehicle routing methods have been suggested, which minimize the routing distances of vehicles to reduce the total transportation cost. But the more considerations the method takes, the higher complexites are involved in a large number of practical situations. The purpose of this paper is to develop a vehicle distribution planning system using heuristic algorithms and simulation techniques for home electronics companies. The vehicle distribution planning system developed by this study involve so complicated and stochastic conditions such as one depot, multiple nodes(demand points), multiple vehicle types, multiple order items, and other many restrictions for operating vehicles. The proposed system is compared with the nearest neighbor method and the savings method in terms of total logistics cost and driving time. This heuristic algorithm and simulation based distribution planning system is efficient in computational complexity, and give improved solutions with respect to the cost as well as the time. This method constructs a route with a minimum number of vehicles for a given demand.

• 한국시뮬레이션학회논문지
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• 제2권1호
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• pp.13-22
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• 1993

In a multiple-bus multiprocessor system in which processors and memory modulus are interconnected through system buses, time delay due to bus contention degrades system performance. In order to reduce such a problem , and optimal bus arbitration scheme and its hardware are neccessary. In this study, performaces of four arbitration schemes are analyzed and compared : fixed-priority, equal-priority, rotating-priority and round-robin priority schemes. For the study, the software simulator of a multiple-bus multiprocessor system is developed by using SLAM II. Simulation results show that, when memory sccesses are evenly distributed to all memory modulus, round-robin priority scheme provides the best performance. But when a hot spot exists, the use of the fixed priority scheme results in the shortest access time.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권8호
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• pp.4120-4132
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• 2017

In this research, we implement a deformable object simulation system using OpenGL's shader language, GLSL4.3. Deformable object simulation is implemented by using volumetric mass-spring system suitable for real-time simulation among the methods of deformable object simulation. The compute shader in GLSL 4.3 which helps to access the GPU resources, is used to parallelize the operations of existing deformable object simulation systems. The proposed system is implemented using a compute shader for parallel processing and it includes a bounding box-based collision detection solution. In general, the collision detection is one of severe computing bottlenecks in simulation of multiple deformable objects. In order to validate an efficiency of the system, we performed the experiments using the 3D volumetric objects. We compared the performance of multiple deformable object simulations between CPU and GPU to analyze the effectiveness of parallel processing using GLSL. Moreover, we measured the computation time of bounding box-based collision detection to show that collision detection can be processed in real-time. The experiments using 3D volumetric models with 10K faces showed the GPU-based parallel simulation improves performance by 98% over the CPU-based simulation, and the overall steps including collision detection and rendering could be processed in real-time frame rate of 218.11 FPS.

• 한국시뮬레이션학회논문지
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• 제14권1호
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• pp.9-18
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• 2005

Attempts to attack hosts in the network have become diverse, due to crackers developments of new creative attacking methods. Under these circumstances the role of intrusion detection system as a security system component gets considerably importance. Therefore, in this paper, we have suggested multiple intrusion detection system based on the contract net protocol which provides the communication among multiple agents. In this architecture, fuzzy rule based system has been applied for agent selection among agents competing for being activated. The simulation models are designed and implemented based on DEVS formalism which is theoretically well grounded means of expressing discrete event simulation models.

• 한국군사과학기술학회지
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• 제10권2호
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• pp.47-52
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• 2007

Missile staging and airframe separation simulation were performed by using a numerical technique for simulating the dynamics of multiple moving bodies. A 6DOF model is fully integrated into the CFD solution procedure to determine the body dynamics. Chimera grid technique offered efficient CFD simulation of multiple moving bodies. Through this simulation the safety of deployed staging and airframe separation mechanism was verified.

• 정보처리학회논문지B
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• 제14B권2호
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• pp.127-134
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• 2007

기계 학습 등 인공 지능 기법의 발전에 힘입어 지능형 주식 거래 시스템에 관한 많은 연구가 이루어져 왔다. 그러나 현실 주식 거래에서 적절한 거래 정책의 수립이 거래의 결과에 커다란 영향을 미치는 중요 요소로 작용하고 있음에도 불구하고, 기존의 연구에서는 예측 모듈의 예측 성능 향상에 주력하였거나, 거래 정책을 다룬 경우라도 예측 모듈에 종속적인 단순한 정책만을 제시하였다. 본 논문에서는 이러한 문제를 개선하기 위한 방안의 하나로, 신경망 기반 주식 거래 시스템의 구축을 위한 통합 개발 도고인 NXShell에서 채택하고 있는 ‘통합 다중 시뮬레이션‘ 기법을 제안한다. 통합 다중 시뮬레이션 기법에서는 신경망의 출력 값과 거래 정책 인자들 간의 모든 주어진 예측기의 특성에 맞는 고유의 최적 거래 정책을 수립한다. 제안된 기법의 효용성을 검증하기 위해, 한국 거래소 시장 및 코스닥 시장에서 수집한 데이터를 사용하여 수행한 거래 성능 비교 실험 결과를 제시한다.