• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.235-237
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• 2005

철도차량에 취부되는 추진장치는 차량의 성능을 결정하는 매우 중요한 요소이다. 이러한 추진장치에 대한 다양한 성능을 평가하고 진단하기 위해 상시계측시스템을 구축하여 활용하고 있다. 이러한 계측장비들은 추진장치에 대한 계측 및 분석을 통한 시험을 평가하고 완성차 시험이나 본선시운전 시험시에 발생할 수 있는 고장원인을 찾아내고 해결하는데 많은 도움을 주고 있다 본 논문에서는 한국형 고속전철차량에 설치되어있는 상시계측시스템을 통해 추진장치에 대한 고장진단을 실시한 내용에 대하여 기술하였다.

• Journal of the Korean Society for Railway
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• v.16 no.3
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• pp.183-188
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• 2013

The purpose of maintaining rolling stock is to perform train service without failure during operation. It is not possible to prevent failure, however, by using periodic preventive maintenance methods, because new rolling stock is made from many electric components and requires the application of IT skills. RAMS (Reliability, Availability, Maintainability, Safety) methods have consequently been applied to new manufactured rolling stock in KORAIL since implementation of the KTX. With this approach it is possible to verify the reliability at the operating stage, and RCM (Reliability Centered Maintenance) methods for maintenance have been applied to manufactured rolling stock since the beginning of KTX service. A RCRM (Reliability Centered Rolling-stocks Maintenance) system suitable for the characteristics of rolling stock and operational factors is introduced in this paper.

• Journal of Intelligence and Information Systems
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• v.26 no.1
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• pp.47-73
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• 2020

KTX rolling stocks are a system consisting of several machines, electrical devices, and components. The maintenance of the rolling stocks requires considerable expertise and experience of maintenance workers. In the event of a rolling stock failure, the knowledge and experience of the maintainer will result in a difference in the quality of the time and work to solve the problem. So, the resulting availability of the vehicle will vary. Although problem solving is generally based on fault manuals, experienced and skilled professionals can quickly diagnose and take actions by applying personal know-how. Since this knowledge exists in a tacit form, it is difficult to pass it on completely to a successor, and there have been studies that have developed a case-based rolling stock expert system to turn it into a data-driven one. Nonetheless, research on the most commonly used KTX rolling stock on the main-line or the development of a system that extracts text meanings and searches for similar cases is still lacking. Therefore, this study proposes an intelligence supporting system that provides an action guide for emerging failures by using the know-how of these rolling stocks maintenance experts as an example of problem solving. For this purpose, the case base was constructed by collecting the rolling stocks failure data generated from 2015 to 2017, and the integrated dictionary was constructed separately through the case base to include the essential terminology and failure codes in consideration of the specialty of the railway rolling stock sector. Based on a deployed case base, a new failure was retrieved from past cases and the top three most similar failure cases were extracted to propose the actual actions of these cases as a diagnostic guide. In this study, various dimensionality reduction measures were applied to calculate similarity by taking into account the meaningful relationship of failure details in order to compensate for the limitations of the method of searching cases by keyword matching in rolling stock failure expert system studies using case-based reasoning in the precedent case-based expert system studies, and their usefulness was verified through experiments. Among the various dimensionality reduction techniques, similar cases were retrieved by applying three algorithms: Non-negative Matrix Factorization(NMF), Latent Semantic Analysis(LSA), and Doc2Vec to extract the characteristics of the failure and measure the cosine distance between the vectors. The precision, recall, and F-measure methods were used to assess the performance of the proposed actions. To compare the performance of dimensionality reduction techniques, the analysis of variance confirmed that the performance differences of the five algorithms were statistically significant, with a comparison between the algorithm that randomly extracts failure cases with identical failure codes and the algorithm that applies cosine similarity directly based on words. In addition, optimal techniques were derived for practical application by verifying differences in performance depending on the number of dimensions for dimensionality reduction. The analysis showed that the performance of the cosine similarity was higher than that of the dimension using Non-negative Matrix Factorization(NMF) and Latent Semantic Analysis(LSA) and the performance of algorithm using Doc2Vec was the highest. Furthermore, in terms of dimensionality reduction techniques, the larger the number of dimensions at the appropriate level, the better the performance was found. Through this study, we confirmed the usefulness of effective methods of extracting characteristics of data and converting unstructured data when applying case-based reasoning based on which most of the attributes are texted in the special field of KTX rolling stock. Text mining is a trend where studies are being conducted for use in many areas, but studies using such text data are still lacking in an environment where there are a number of specialized terms and limited access to data, such as the one we want to use in this study. In this regard, it is significant that the study first presented an intelligent diagnostic system that suggested action by searching for a case by applying text mining techniques to extract the characteristics of the failure to complement keyword-based case searches. It is expected that this will provide implications as basic study for developing diagnostic systems that can be used immediately on the site.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.6
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• pp.41-50
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• 2011

This article is concerned with the technology to provide car driver the car's status which are composed of car trouble code in car engine and many sensors. In addition, it installs vehicle diagnostic programs on wireless communication's portable device, for example, Smart phone, PDA, PMP, UMPC. As a result, this is to provide car manager with many information of car sensors when we go to car maintenance. it can monitor relevant information on vehicle by portable device in real time, alert drivers with specific messages and also enable them to address abnormalities immediately. Moreover, the technology could help the drivers who perhaps don't know very well about their vehicles to drive safely and economically as well; the reason is because the whole system is composed of just Vehicle-information collecting device and personal wireless communication's portables and transfers the relating data to server computers through wireless network in order to handle information on vehicles. This technology make us monitor vehicle's running, failure and disorder by using wireless communication's portable device. Finally, this study system is composed of a lot of application to display us the car's status which get car's inner sensor information while driving a car.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.299-312
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• 2021

Autonomous vehicles using V2X can drive safely information on areas outside the sensor coverage of autonomous vehicles conventional autonomous vehicles. As V2X technology has emerged as a key component of autonomous vehicles, research on V2X security is actively underway research on risk analysis due to failure of V2X communication is insufficient. In this paper, the service scenario and function of autonomous driving system V2X were derived by presenting the intersection scenario of the autonomous vehicle, the malfunction was defined by analyzing the hazard of V2X. he ISO26262 Part3 process was used to analyze the risk of malfunction of autonomous vehicle V2X. In addition, a fault injection scenario was presented to verify the fail-safe of the simulation-based intersection scenario.

• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.242-244
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• 2004

현재, 고속철도차량의 국내기술확보를 위해 한국형 고속전철이 개발되어 단품시험, 완성차시험, 공장시험 등을 통해 기본적인 성능을 확인한 후 현재는 본선시운전 시험을 실시하고 있다. 시제차량의 성능 및 기능을 종합적이고 효율적으로 확인하기 위해 고속철도 시운전시험시 상시 계측시스템을 시제차량에 설치하여 운영하고 있다. 본 논문에서는 상시계측시스템을 이용하여 보조전원장치에 대한 고장진단을 실시한 것에 대하여 기술하였다.

• The KIPS Transactions:PartD
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• v.14D no.6
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• pp.649-656
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• 2007

Today, controller area network(CAN) is a field bus that is nowadays widespread in distributed embedded systems due to its electrical robustness, low price, and deterministic access delay. However, its use safety-critical applications has been controversial due to dependability limitation, such as those arising from its bus topology. Thus it is important to analyze the performance of the network in terms of load of data bus, maximum time delay, communication contention, and others during the design phase of the controller area network. In this paper, a simulation algorithm is introduced to evaluate the communication performance of the vehicle network and apply software base fault injection techniques. This can not only reduce any erratic implementation of the vehicle network but it also improves the reliability of the system.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.10
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• pp.47-55
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• 2015

To verify the function of vehicle is becoming more and more difficult because many electronic control units have been embedded in vehicle with development of electronics industry. The reliability of vehicle should be considered above all important because malfunction of vehicle can cause damage of human life. In this paper, defect diagnosis platform based on CAN network is proposed to improve the reliability of vehicle. Reliability of vehicle is significantly increased by adopting the structural test via dedicated test path after manufacturing. Besides, the test cost is reduced because additional test pins are not required.

• The tire
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• s.93
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• pp.40-41
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• 1981

일본도로공단에서는 요즈음 동공단에석 관리하고 잇는 전국고속도로와 일반유료도로에서 1979년(1월~12월)에 발생한 교통사고와 차량고장의 건수를 도로별ㆍ원인별로 조사하는 한편 차종별ㆍ원인별로도 종합분석 하였다.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2003.05a
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• pp.545-550
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• 2003

교통사고의 요인은 크게 운전자 요인, 도로환경 요인, 차량 요인으로 구분 할 수 있다. 운전자의 안전의식미비, 심리상태, 피로 등 운전자 요인과 차량의 고장, 정비상태 불량 등 차량요인은 운수업체의 경영과 직ㆍ간접적인 관계가 있으므로 사고예방을 위한 경영자의 안전의식이 교통사고에 영향을 끼친다는 것은 분명한 사실이다.(중략)