• 한국자동차공학회논문집
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• 제18권1호
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• pp.44-50
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• 2010

Durability performance evaluation technology using Virtual Testing Method is a new concept of a vehicle design, which can reduce the automotive components design period and cost. In this paper, the fatigue life of an aluminum knuckle of a passenger car is evaluated using virtual testing method. The flexible multibody dynamic model of a front half car module is generated and solved with service loads which are measured from Belgian roads. Using a multibody dynamic analysis software, the flexible multibody dynamic simulation of a half car model is carried out and the dynamic stress profile of an aluminum knuckle is acquired. The stress profile is exported to a fatigue analysis software and durability performance of an aluminum knuckle is evaluated.

• 한국컴퓨터정보학회논문지
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• 제18권8호
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• pp.105-111
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• 2013

본 논문에서는 스마트 센서 응용 소프트웨어를 테스팅하기 위한 효율적인 방법인 가상 센서 시스템을 제안한다. 센서 응용 소프트웨어를 테스트하는 보편적인 방법은 테스트 보드에 센서를 직접 연결시켜 테스팅 환경의 센서 측정값으로 응용소프트웨어를 테스팅 하는 것이다. 센서 측정값을 입력으로 센서 응용 소프트웨어를 테스팅함으로 발생하는 문제는 테스트 데이터가 제한적이라는 것이다. 즉, 테스트 데이터가 센서로부터 생성되기 때문에 소프트웨어 테스터가 테스트 데이터를 조절하지 못하는 문제가 있다. 이러한 문제를 해결하기 위해 가상센서 시스템을 제안한다. 가상 센서 시스템은 소프트웨어 테스터가 센서의 측정값을 조절할 수 있게 한다. 가상 센서 시스템에서 센서 선택, 센서 특성화, 출력 패턴 정의의 세 단계를 통해 가상 센서를 정의한다. 가상 센서 시스템을 통해 조절 가능한 센서 측정값을 사용함으로써 센서 응용 소프트웨어에 대한 효율적인 테스트가 가능하다. 본 연구의 유용성을 보이기 위해 가상 센서 시스템을 안드로이드 앱의 센서 프로그램에 적용해 보고 실험 결과를 보인다.

• Advances in aircraft and spacecraft science
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• 제5권2호
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• pp.251-258
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• 2018

This work illustrates the progress of a TAS activity at exploring the challenges and the benefits of the Virtual Shaker Testing (VST) approach. The definition and the validation of new computational methodologies with respect to the state of the art were encouraged throughout this activity. The shaker Finite Element (FE) model in lateral configuration was built for the purpose and it was merged with the SpaceCraft (S/C) FE model, together with the S/C-Shaker adapter. FE matrices were reduced through the Craig-Bampton method. The VST transient analysis was performed in MATLAB(R) numerical computing environment. The closed-loop vibration control is accounted for and the solution is obtained through the fourth-order Runge Kutta method. The use of pre-existing built-in functions was limited by authors with the aim of tracing the impact of all the problems' parameters in the solution. Assumptions and limitations of the proposed methodology are detailed throughout this paper. Some preliminary results pertaining to the current progress of the activity are thus illustrated before the conclusions.

• 비파괴검사학회지
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• 제25권3호
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• pp.157-162
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• 2005

In order to evaluate the corrosion of reinforcing steel-bars (rebar) in concrete, a nondestructive evaluation by the half-cell potential method is currently applied. In this study, potentials measured on a concrete surface are compensated into those on the concrete-rebar interface by the inverse boundary element method (IBEM). Because these potentials are obtained three-dimensionally (3-D), 3-D visualization is desirable. To this end, a visualization system has been developed by using VRML (Virtual Reality Modeling Language). As an application, results of a reinforced concrete (RC) slab with corroded rebars are visualized and discussed.

• 한국정보처리학회논문지
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• 제4권11호
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• pp.2832-2839
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• 1997

본 연구에서는 Asynchronous Transfer Mode (ATM) 계층의 기능중 유휴 가상 채널에 프로토콜 프로토콜 적합성 시험 제어 기능을 갖게 하여 Test Coordination Procedures (TCP) 채널로 활용하는 방안을 제시하였다. 프로토콜 적합성 시험을 위하여 국제 기구에서 권고하고 있는 방법중 원격 시험 방법을 선택하면 System Under Test (SUT)측에 서 능동적으로 Test Event를 발생시켜야 하는 경우에 개발자가 직접 수동적으로 운용을 하거나, Implementation Under Test (IUT)에 대한 제어 및 관찰이 불가능한 경우도 발생하게 된다. ATM망에서 프로토콜 적합성 시험시 시험 영역(Test Coverage)을 최대화하고, 오류검출 영역(Fauit Coverase)을 극대화하기 위해서는 원격시험방법보다는 분산시험방법이 적절하며, 분산시험방법을 채택할 경우 TCP를 구현하기 위하여 시험정보를 전달하기 위한 채널을 확보하는 것이 요구된다. 본 고에서 제안하고 있는 방법은 오류 검출 영역을 극대화 시키고 오퍼레이터의 개입없이 시험의 자동화 구현이 용이하고, ATM장치의 정상동작에는 영향을 주지 않음은 물론 시험제어를 위한 별도의 채널을 확보하지 않고서도 분산시험방법을 적용할 수 있다는 점 을 특징으로 들 수 있다．

• 한국생산제조학회지
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• 제21권3호
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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.

• 자동차안전학회지
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• 제15권3호
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• pp.34-42
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• 2023

Simulation-based virtual testing is known to be a major requirement for verifying the safety of autonomous driving functions. However, in the simulation environment, there is a difficulty in that all driving environments related to the autonomous driving system must be realistically modeled. In particular, C-ITS (Cooperative-Intelligent Transport Systems) is essential for urban autonomous driving of Lv.4, but the approach to modeling for C-ITS service in the MILS (Model in the Loop Simulation) environment is not yet clear. Therefore, this paper aims to deal with V2X (Vehicle to Everything) modeling methods to effectively apply C-ITS-based autonomous cooperative driving services in the MILS environment. First, major C-ITS services and use cases for autonomous cooperative driving are analyzed, and a modeling method of V2X signals for C-ITS service simulation is proposed. Based on the modeled V2X messages, the validity of the proposed approach is reviewed through simulations on the C-ITS service use case.

• 한국ITS학회 논문지
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• 제20권6호
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• pp.331-345
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• 2021

시뮬레이션 기반 가상 검증은 자율주행 기능의 안전성 검증을 위한 주요 요구사항으로 간주되고 있다. 가상 검증 환경에서는 자율주행차량과 주행 환경은 모두 모델링되어야 하며 특히, 카메라 및 레이더 센서와 같은 환경 센서의 현실적인 모델링이 중요하다. 하지만 현실적인 인식 결과를 일관되게 제공하기 위한 모델링에 관한 연구는 부족한 실정이다. 이에 본 논문에서는 MILS(Model in the Loop Simulation) 환경에서 현실적인 오브젝트 인식 결과를 제공하기 위한 센서 모델링 방법이 다루어진다. 먼저, 모델링을 위한 주요 파라미터가 정의되며 카메라 및 레이더 센서의 오브젝트 감지 특성이 분석된다. 분석 결과로부터 모델링된 가상 센서 모델의 감지 특성은 실물 센서와의 상관계수 분석을 통해 유효성이 검증된다.

• 비파괴검사학회지
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• 제23권3호
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• pp.189-197
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• 2003

Nucleation of a crack is readily defected by acoustic emission (AE) method. One powerful technique for AE waveform analysis has been developed as SiGMh (Simplified Greens functions for Moment tensor Analysis), as crack kinematics of locations, types and orientations are quantitatively determined. Because these kinematical outcomes are obtained as three-dimensional (3-D) locations and vectors, 3-D visualization is definitely desirable. To this end, the visualization system has been developed by using VRML (Virtual Reality Modeling Language). As an application, failure protest of a reinforced concrete beam is discussed.

• Nuclear Engineering and Technology
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• 제36권4호
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• pp.346-356
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• 2004

14 Pressurized Water Reactors (PWR) in Korea use a remote monitoring system (RMS), which have been used in Korea since 1998. A Memorandum of Understanding on Remote Monitoring, based on Enhanced Cooperation on PWRs, was signed at the 10th Safeguards Review Meeting in October 2001 between the International Atomic Energy Agency (IAEA) and Ministry Of Science and Technology (MOST). Thereafter, all PWR power plants applied for remote monitoring systems. However, the existing method is high cost (involving expensive telephone costs). So, it was eventually applied to an Internet system for Remote Monitoring. According to the Internet-based Virtual Private Network (VPN) applied to Remote Monitoring, the Korea Atomic Energy Research Institute (KAERI) came to an agreement with the IAEA, using a Member State Support Program (MSSP). Phase I is a Lab test. Phase II is to apply it to a target power plant. Phase III is to apply it to all the power plants. This paper reports on the penetration testing of Phase I. Phase I involved both domestic testing and international testing. The target of the testing consisted of a Surveillance Digital Integrated System (SDIS) Server, IAEA Server and TCNC (Technology Center for Nuclear Control) Server. In each system, Virtual Private Network (VPN) system hardware was installed. The penetration of the three systems and the three VPNs was tested. The domestic test involved two hacking scenarios: hacking from the outside and hacking from the inside. The international test involved one scenario from the outside. The results of tests demonstrated that the VPN hardware provided a good defense against hacking. We verified that there was no invasion of the system (SDIS Server and VPN; TCNC Server and VPN; and IAEA Server and VPN) via penetration testing.