• 인터넷정보학회논문지
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• 제18권3호
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• pp.29-36
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• 2017

오늘날 3D 다이내믹 시뮬레이션은 많은 산업들과 밀접한 관계를 가지고 있다. 과거에는 자동차 충돌, 건축물 분야에서 주로 사용되었으나 최근에는 영화나 게임 분야에도 물리 시뮬레이션이 중요한 역할을 하고 있다. 일반적으로 3D 물체를 사실적으로 표현하기 위해서는 많은 수학적 연산이 필요하기 때문에 기존의 CPU 기반의 응용 프로그램들은 이러한 많은 연산량을 실시간으로 처리하는데 무리가 있다. 최근 그래픽 하드웨어의 발전과 아키텍쳐의 개선으로 GPU는 기존의 렌더링 연산뿐만 아니라 범용 목적의 연산 기능을 제공하고 있고 이러한 GPU를 활용하는 연구가 활발히 진행되고 있다. 본 논문에서는 GPU를 이용한 천 시뮬레이션 수행시 수행 성능을 최적화하기 위하여, GPU 셰이더의 실행 환경 변화에 따른 천 시뮬레이션 알고리즘의 수행 성능의 변화를 분석하였다. GPU를 이용한 천 시뮬레이션은 GLSL 4.3의 Compute shader를 사용하여 스프링 중심 알고리즘과 노드 중심 알고리즘을 PC기반으로 구현하였고, GLSL Compute shader의 다양한 워크 그룹 (Work Group) 크기와 차원 분배에 따른 연산 속도의 변화를 비교 분석하였다. 실험은 5,000 프레임까지 10회 반복 수행하여 FPS(Frame Per Second)의 평균을 구하여 진행하였다. 실행결과, 노드 중심의 알고리즘이 오히려 스프링 중심의 알고리즘 보다 빠른 수행속도를 보여 주었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(2)
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• pp.176-179
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• 2000

Fault simulation is often necessary to determine the fault coverage of a given test, that is, to find all the faults detected by test. In this paper we implement a deductive fault simulation using counting method. Counting method uses f$\sub$ｉ/ of fault table and Search list to compute set operation. f$\sub$ｉ/ was counted by fault list of input gate. And we propagate fault list from primary inputs toward primary output by comparing with controling sum. It improved performance by reducing search of faults.

• 한국시뮬레이션학회논문지
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• 제5권1호
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• pp.13-27
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• 1996

The management of blood inventory is very important within the medical care system. The efficient management of blood supplies and demands for transfusion is of great economic and social importance to both hospitals and patients. Fro any blood type, there is a complex interaction among the optimal inventory level, daily demand level , daily supply level, transfusion to crossmatch ratio, crossmatch release period, issuing policy and the age of arriving units that determine the shortage and outdate rate. In this paper, we develop an efficient decision rule for blood inventory management in a hospital blood bank which can support efficient hospital blood inventory management using simulation, The primary use of the efficient decision rule will be to establish minimum cost function which consists of inventory levels , period in inventory, outdate and shortage rate for whole blood and various component inventories for a hospital blood bank or a transfusion service, If the adminstrator compute the mean daily demand for each blood type, the mean daily supply for each blood type, the length of the crossmatch release period and the average transfusion to crossmatch ratio , then it is possible to apply the efficient decision rule to compute the optimal inventory level, inventory period , outdate and shortage rate. This rule can also be used as a decision support system that allows the blood bank adminstrator to do sensitivity analysis related to controlled blood inventory parameters.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2005년도 춘계학술대회
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• pp.182-184
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• 2005

In this study, we propose a chi-squared test of spherical symmetry. The advantage of this test is that the test statistic and its asymptotic p-value are easy to compute. A simulation study is conducted to study the accuracy, in finite samples, of the limiting distribution of the test statistic under spherical symmetry. The power of our test is compared with those of other tests for spherical symmetry in various alternative distributions via simulation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.658-662
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• 1988

The performance of a strapdown attitude reference system(SDARS) under dynamic environments was analyzed by means of computer simulation. The study is aimed toward the performance evaluation in the presence of translational or angular vibration during 20 sec of flight time. The simulation was based on the error model of rate gyro, and Euler angle algorithm was employed to compute the attitude.

• Journal of the Korean Data and Information Science Society
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• 제16권2호
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• pp.227-236
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• 2005

A chi-squared test of spherical symmetry is suggested. This test is easy to apply in practice since it is easy to compute and has a limiting chi-squared distribution under spherical symmetry. The result of Park(1998) can be used to show that it has the limiting chi-squared distribution. A simulation study is conducted to study the accuracy, in finite samples, of the limiting distribution. Finally, a simulation study that compares the power of our test with those of other tests of spherical symmetry is performed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.47.5-47
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• 2002

Some integration methods for the linear subsystems are examined and which algorithm is optimal for real-time simulation is considered. First, a number of typical integration methods for a linear time-invariant system are given. Then, the dynamic errors are shown both from the point of view of characteristic root errors and transfer function errors. After that we compute the dynamic errors of integration and choose the appropriate method for each system.

• 품질경영학회지
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• 제27권1호
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• pp.80-90
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• 1999

In this paper, reliability estimation using Gibbs sampler is considered for the mixture model with Gamma family, Gibbs sampler is derived to compute the features for the posterior distribution. By simulation study, the maximum likelihood estimator and the Gibbs estimator are obtained. A numerical study with a simulated data is provided.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.547-552
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• 2003

In mold machining, there are many concave machining regions where chatter and tool deflection occur since MRR (material removal rate) increases as curvature increases even though cutting speed and depth of cut are constant. Boolean operation between stock and tool model is widely used to compute MRR in NC milling simulation. In finish cutting, the side step is reduced to about 0.3mm and tool path length is sometimes over 300m. so Boolean operation takes long computation time and includes much error if the resolution of stock and tool model is larger than the side step. In this paper, curvature of CL(cutter location) surface and side step of tool path is used to compute the feedrate for constant MRR machining. The data structure of CL surface is Z-map generated from NC tool path. The algorithm to get local curvature from discrete data was developed and applied to compute local curvature of CL surface. The side step of tool path was computed by point density map which includes cutter location point density at each grid element. The feedrate computed from curvature and side step is inserted to new tool path to regulate MRR. The resultants wire applied to feedrate optimization system which generates new tool path with feedrate from NC codes for finish cutting. The system was applied to speaker mold machining. The finishing time was reduced to 12.6%. tool wear was reduced from 2mm to 1.1mm and chatter marks and over cut on corner were removed.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.126-129
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• 2008

This paper concerns the progressive die design for an automotive bracket part aided by the computer simulation in order to eliminate the inferiority such as the crack. The computer simulation of the progressive forming process is utilized in order to investigate cause of the cracks. This paper proposes a new guideline for the die design which modifies intermediate shapes and adds intermediate forming stages in progressive forming process. The effectiveness of the proposed design is verified by the computer simulation. The simulation result shows that the modified die design for the progressive forming process can eliminate the crack and improve quality of the automotive bracket part.