• Journal of Institute of Control, Robotics and Systems
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• v.16 no.9
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• pp.905-912
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• 2010

Modern version of advanced supersonic fighter have ATCS (Automatic Thrust Control System) to maximum flight safety, fuel efficiency and mission capability the integrated advanced autopilot system such as TFS (Terrain Following System), GCAS (Ground Collision Avoidance System) and AARS (Automatic Attitude Recovery System) and etc. This paper addresses the design and verification of ATCS based on advanced supersonic trainer in HILS (Hardware In the Loop Simulator) with minimum hardware modification to reduce of development cost and maintain of system reliability. The function of ATCS is consisted of target speed hold mode in UA (Up and Away) and angle of attack hold mode in PA (Power Approach). The real-time pilot evaluation reveals that pilot workload is minimized in cruise and approach flight stage by ATCS.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1252-1253
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• 2011

The railway signaling system is being converted to the computer system from the existing mechanical device, and the dependency on software is being increased rapidly. Though the size and degree of complexity of software for railway signaling system are slower than the development speed of hardware, it is expected that the size will be grown bigger gradually and the degree of complexity will be increased also. Accordingly, the validation of reliability and safety of embedded software for train control system was started to become influential as the important issue. In this paper, we presented boundary value analysis tool for railway signaling system software, and presented its result of implementation.

• Journal of Advanced Research in Ocean Engineering
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• v.1 no.1
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• pp.36-43
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• 2015

Since the crack generation and its propagation caused by welding defects is one of the main hull damage patterns, the simulation of crack propagation process has an important significance for ship safety. Based on interface element method, a finite element model to simulate crack propagation is studied in the paper. A Lennard-Jones type potential function is employed to define potential energy of the interface element. Tensile tests of steel flat plates with initial central crack are carried out. Surface energy density and spring critical stress that are suitable for the simulation of crack propagation are determined by comparing numerical calculation and tests results. Based on a large number of simulation results, the curve of simulation correction parameter plotted against the crack length is calculated.

• Annual Conference of KIPS
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• 2017.04a
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• pp.591-594
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• 2017

안전 필수 시스템(Safety-critical system) 중 하나인 차량 전장용 운영체제의 엄밀한 검증을 위하여 모델 기반 테스트 생성기법들이 연구되어 왔다. 그러나 기존의 연구들은 이러한 차량 전장용 운영체제에서 빈번히 사용되는 주기적인 동작을 요하는 작업들에 대한 테스트 생성 문제를 해결하지 못하였다. 본 연구에서는 주기적 태스크의 검증을 지원하지 않았던 기존의 테스트 케이스 생성기에 알람 모델을 추가하여 보완하였다. 이를 통해 차량 전장용 운영체제의 검증에 있어서 주기적 태스크를 포함한 다양한 테스트 케이스를 생성할 수 있었고 차량 전장용 운영체제의 보다 엄밀한 검증이 가능해졌다.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.861-866
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• 2007

This paper presents development of a vehicle lateral and longitudinal control for autonomous driving control and test results obtained using an electric vehicle. Sliding control theory has been used to develop a vehicle speed and distance control algorithm. The longitudinal control algorithm that maintains safety and comfort of the vehicle consists of a cruise and STOP&GO control depending on traffic conditions. Desired steering angle is determined through the lateral position error and the yaw angle error based on preview optimal control. Motor control inputs have been directly derived from the sliding control law. The performance of the autonomous driving control which is integrated with a lateral and longitudinal control is investigated by computer simulations and driving test using an electric vehicle. Electric vehicle system consists of DC driving motor, an electric power steering system, main controller (Autobox)

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.62 no.1
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• pp.30-35
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• 2013

Many function of railway signalling system which is in charge of most core function in a railway system are being operated by the software according to the development of computer technology. Accordingly, the source code testing to verify the safety of the railway signalling system software becomes to be more important, and related international standards highly recommend verifications on the source code also. For this reason, several related studies on vital source code verification were executed from several years ago in Korea. This paper performed tests through the application to railway signalling system being applied to the existing actual domestic railway sites through automated testing tools for coding rules of signalling system software and another signaling system software under development in Korea recently, and analyzed their results.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.166-169
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• 2011

안전성이 중요한 실시간 내장형 시스템인 유도조종장치에서 시간 제약성을 만족하는 것은 매우 중요한 문제이다. 기존 유도조종장치 소프트웨어 개발에서는 주로 테스트 단계에서 시간 제약성 만족을 확인한다. 하지만 이 방법은 늦은 오류의 발견으로 인해 전체 소프트웨어 개발 비용이 커질 가능성이 있다. 이러한 단점을 극복하기위해 본 논문에서는 설계 단계에 정형 기법을 적용하여 유도조총장치 소프트웨어의 시간 제약성을 검증하고자 한다. 이를 위해서 실시간 시스템에 대한 모델링과 검증을 지원하는 TIMES 도구를 유도조종장치 소프트웨어 설계에 적용하는 사례 연구를 수혈하고 그 결과를 분석 및 평가하였다.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1047-1056
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• 2004

The turnout system is typical railway facility to be in the way of conventional railway line's speed-up. The KNR(Korean National Railroad) :has a speed limit regulation(130km/h) for the passing the turnout to guarantee a safety. This research had been performed to confirm the propriety of this regulation by using experimental and analytical way before it was carried out. The reasonableness of the speed-limit regulation was judged base on the several experiments. It was proved that the regulation was not useless as it had been regarded and very important guide at least up to now.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.667-670
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• 2001

For major structural components periodic inspections and integrity assessments are needed for the safety. However, many flaws are undetectable because sampling inspection is carried out during in-service inspection. Probabilistic integrity assessment is applied to take into consideration of uncertainty and variance of input parameters arise due to material properties and undetectable cracks. This paper describes a Probabilistic Fracture Mechanics(PEM) analysis based on the Monte Carlo(MC) algorithms. Taking a number of sampling data of probabilistic variables such as fracture toughness value, crack depth and aspect ratio of an initial surface crack, a MC simulation of failure judgement of samples is performed. For the verification of this analysis, a comparison study of th PFM analysis using a commercial code, mathematical method is carried out and a good agreement was observed between those results.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1159-1160
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• 2008

For safety railway vehicle movement, analysis and recoding of railway vehicle speed and driving information has written by law. nowadays, base in europe, these system is spread of various advanced country. In this paper, We implement an event recorder which record the driving and breaking information of running railway vehicle. For the event recorder, We designed the data structures with data analysis tools and a protocol between Event recorder and data analysis tool. The verification of Analysis tool was tested by to made data by Event Recorder's emulator and information of real railway driving recording.