• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.3
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• pp.368-375
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• 2012

Durability performance evaluation of automotive components is very important and time consuming task. In this paper, to reduce vehicle component development time and cost virtual testing simulation technology is used to evaluate durability performance of a passenger car front aluminum sub-frame. Multibody dynamics based vehicle model and virtual test simulation model of a half car road simulator are validated by comparisons between rig test results and simulation results. Durability life prediction of the sub-frame is carried out using the model with road load data of proving ground which can evaluate accelerated durability life. We found that the durability performance of the sub-frame is sufficient and it can be predicted within short time compared to rig test time.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.4 s.109
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• pp.355-365
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• 2006

The coupled time-integration method with a staggered algorithm based on computational structural dynamics (CSD), finite element method (FEM) and computational fluid dynamics (CFD) has been developed in order to demonstrate physical vibration phenomena due to dynamic aeroelastic excitations. Virtual flutter tests for the spanwise curved ing model have been effectively conducted using the present advanced computational method with high speed parallel processing technique. In addition, the present system can simultaneously give a recorded data file to generate virtual animation for the flutter safety test. The results for virtual flutter test are compared with the experimental data of wind tunnel test. It is shown from the results that the effect of spanwise curvature have a tendency to decrease the flutter dynamic pressure for the same flight condition.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.4
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• pp.144-150
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• 2003

Recently, the virtual test techniques using computer simulation play an important part in the vehicle development procedures in order to reduce the development time and cost by replacing the physical prototypes of the vehicle components or systems with the virtual prototypes. In this paper, virtual durability test procedures for the vehicle suspension module have been developed. Virtual durability test consists of dynamic simulation computing load history of suspension components, fatigue analysis computing the life of components. A vehicle suspension module for dynamic simulation are developed and validated by comparison with the measured data obtained from the field vehicle test. And on the basis of the validated vehicle suspension model, fatigue analysis has been performed for the virtual durability design of the suspension components.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.457-464
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• 2005

The coupled time-integration method with a staggered algorithm based on computational structural dynamics (CSD), finite element method (FEM) and computational fluid dynamics (CFD) has been developed in order to demonstrate physical vibration phenomena due to dynamic aeroelastic excitations. Virtual flutter tests for the spanwise curved wing model have been effectively conducted using the present advanced computational methods with high speed parallel processing technique. In addition, the present system can simultaneously give a recorded data fie to generate virtual animation for the flutter safety test. The results for virtual flutter test are compared with the experimental data of wind tunnel test. It is shown from the results that the effect of spanwise curvature have a tendency to decrease the flutter dynamic pressure for the same flight condition.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.315-316
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• 2022

항해 안전 강화 및 자율운항선박 대응을 위하여 디지털 항로표지 요구가 증가하고 있다. 이에 따라 해양 상황 및 선박 맞춤의 디지털 항로표지 서비스 연구를 수행하였다. 선박 맞춤의 항로표지 생성을 위한 해양 상황 정보 및 선박 위치 정보 수집 방법과 서버와 단말간의 디지털 항로표지 정보 제공 방안이 요구된다. 이러한 요구에 따라 서비스 표준 및 부처의 시스템을 활용하여 서비스를 제공하는 방법에 대하여 검토하였다. 국립해양측위정보원에서는 GICOMS에서 제공하는 선박 및 항로표지 정보를 수집하고 있으며, 이 시스템과 연동하여 디지탈 항로표지를 생성을 수행할 수있다. 또한 서비스 제공을 위하여 AIS 및 S-100 기반의 서비스 제공 표준이 있으며, 이 표준을 활용하여 서비스 제공이 가능할 것이다. 본 논문에서는 서비스 제공을 위한 시스템을 제안하였으며, 실내 시험을 통하여 기능을 점검하였다. 추후 실외시험을 통하여 실제 시스템 구성 운영을 검증하며, GICOMS 연동의 가상 항로표지 방송 시스템을 구성하여 AIS 서비스 제공 방안에 대하여 검토할 예정이다.

• Journal of the KSME
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• v.52 no.1
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• pp.50-54
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• 2012

감성품질로서의 BSR(Buzz, Squeak, Rattle)은 시스템의 공진특성으로 인해 부품 간의 간극에서 발생하는 간섭현상이며, 재료의 열화 특성과 조립공차의 영향으로 확률적으로 발생하는 신뢰성 문제이다. 일반적으로 BSR 문제는 제품의 개발 과정 중 완료 단계에 발견되고 있으며 설계 사양 변경이 제한적이고 고비용의 시험에 의해 해결되어 왔다. 따라서 초기 설계 단계에서 BSR의 발생을 최소화하기 위하여 재료의 열화와 결합부 이완을 고려한 CAE를 통한 BSR 가상 평가 방법이 필요하다.

• Proceedings of the Korea Contents Association Conference
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• 2018.05a
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• pp.463-464
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• 2018

리얼리티를 추구하는 영상기술의 발달은 가상현실을 구현하는 하드웨어의 발달을 불러왔다. 최근의 가상현실 콘텐츠들은 프로토타입이나 게임에의 시험 적용을 넘어 영화시장에도 문을 두드리고 있다. VR 콘텐츠가 보급되기 위해서는 하드웨어 뿐 아니라 콘텐츠의 제작방식에도 기존과 다른 접근 방식이 필요하다는 내용들이 제작 사례들을 통해 알려지고 있다. 본문에서는 VR 단편 영화의 카메라 설정과 관객들의 청취에 방해요소들을 사전에 줄여나가기 위해 모션캡쳐를 통해 사전영상제작을 수행한 사례를 통해 필요한 사전제작의 작업공정을 분석해 보았다.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.383-385
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• 2013

안드로이드의 최상위 윈도우를 활용하여 광과민성 증후군자를 위한 모바일용 가상 색 오버레이를 구현하였다. 필름 오버레이의 색도 정보와 투과율을 분광측색계로 측정하여 가상 색 오버레이에 적용할 색상 정보를 추정하는 방법을 제안하였고, Intuitive Overlays에서 표현하는 모든 색상을 구현하였다. 시험 결과 기존의 필름 오버레이를 사용한 것과 동일한 효과를 얻었다.

• Journal of the Korea Society of Computer and Information
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• v.12 no.5
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• pp.103-112
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• 2007

In this paper, we implement a hypervisor that runs multiple uC/OS-II real-time kernels on one microprocessor. The hypervisor virtualizes microprocessor and memory that are main resources managed by uC/OS-II kernel. Microprocessor is virtualized by controlling interrupts that uC/OS-II real-time kernel handles and memory is virtualized by partitioning physical memory. The hypervisor consists of three components: interrupt control routines that virtualize timer interrupt and software interrupt, a startup code that initializes the hypervisor and uC/OS-II kernels, and an API that provides communication between two kernels. The original uC/OS-II kernel needs to be modified slightly in source-code level to run on the hypervisor. We performed a real-time test and an independent computation test on Jupiter 32-bit EISC microprocessor and showed that the virtualized kernels run without problem. The result of our research can reduce the hardware cost, the system space and weight, and system power consumption when the hypervisor is applied in embedded applications that require many embedded microprocessors.

• Journal of the Korea Society for Simulation
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• v.22 no.1
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• pp.53-61
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• 2013

The purpose of this paper is to examine how the humans learn and perceive the weight of objects corresponding to visual information in virtual environment. We conducted two kinds of load-on-tasks with two virtual objects that have same weight but different visual cues; have same visual cues but changed weight by trails. We found that the subject could not generate appropriate force for the smaller and changed weight objects in the beginning of the trials. the discrepancy between the expected weight and actual force consequences sue to visually invoked size and previous experience made subjects perceive the small object were heavier. one the other hand, after the tasks were repeated, the subject responded the weights were the same or very similar when the mismatch between the expected weight and the actual weight became vanished. this means that the sensorimotor feedback influences the anticipatory control scheme and weight perception aggressively in virtual environment.