• Journal of the Korean Society for Railway
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• v.19 no.2
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• pp.145-158
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• 2016

This paper introduces a risk graph which is one method for determining the SIL as a measure of the effectiveness of signaling system. The purpose of this research is to make up for the weakness of the qualitative determination, which has input value ambiguity and a boundary problem in the SIL range. The fuzzy input valuable consists of consequence, exposure, avoidance and demand rate. The fuzzy inference produces forty eight fuzzy rule by adapting the calibrated risk graph in the IEC 61511. The Max-min composition is utilized for the fuzzy inference. The result of the fuzzy inference is the fuzzy value. Therefore, using the de-fuzzification method, the result should be converted to a crisp value that can be utilized for real projects. Ultimately, the safety requirement for hazard is identified by proposing a SIL result with a tolerable hazard rate. For the validation the results of the proposed method, the fuzzy risk graph model is compared with the safety analysis of the signaling system in CENELEC SC 9XA WG A10 report.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.06a
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• pp.163-164
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• 2014

본 논문에서는 항만 입출항시 선박의 안전 강화를 위하여, 항만 PNT(Position, Navigation, and Timing) 수신 모듈의 예상 측위 정확도와 그 오차수준을 평가하여 사용자에게 제공하기 위한 해상 PNT 정보의 신뢰도 서비스 개념에 대해 다룬다. 국제해사기구(IMO)에서 요구하는 해양항법성능인 항만 입출항시의 측위정확도(Accuracy)와 무결성(Integrity), 그리고 가용성(Availability)을 충족하기 위한 성능 평가기법과 성능 검증방법에 대해 제시한다. 사용자 관점에서의 GPS 오차수준을 분석하기 위하여, 신뢰도 측정 및 평가를 위한 수평보호수준(HPL, Horizontal Protection Level)과 스탠포드 다이어그램 분석을 통한 평가를 실시하여, 신뢰도 측정지수를 기반으로 사용자에게 신뢰성 수준을 제공하기 위한 방안을 제시한다.

• Proceedings of the Korean Reliability Society Conference
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• 2011.06a
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• pp.271-279
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• 2011

Automotive safety integrity level of hardware components can be achieved by satisfying quantitative and qualitative requirements. Based on ASIL, quantitative requirements are composed of hardware architectural metrics and evaluation of safety goal violations due to random hardware failures in ISO 26262. In this paper, the types of hardware failures will be defined and classified. Based on various metrics related with hardware failures, design essentials to achieve hardware safety integrity will be studied specifically. Issues associated with hardware development and assessment process are presented briefly.

• Journal of the Korean Society for Railway
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• v.19 no.2
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• pp.170-186
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• 2016

This paper introduces a multi-phase fuzzy risk graph model, representing a method for determining for SIL values for railway industry systems. The purpose of this paper is to compensate for the shortcomings of qualitative determination, which are associated with input value ambiguity and the subjectivity problem of expert judgement. The multi-phase fuzzy risk graph model has two phases. The first involves the determination of the conventional risk graph input values of the consequence, exposure, avoidance and demand rates using fuzzy theory. For the first step of fuzzification this paper proposes detailed input parameters. The fuzzy inference and the defuzzification results from the first step will be utilized as input parameters for the second step of the fuzzy model. The second step is to determine the safety integrity level and tolerable hazard rate corresponding to be identified hazard in the railway industry. To validate the results of the proposed the multi-phase fuzzy risk graph, it is compared with the results of a safety analysis of a level crossing system in the CENELEC SC 9XA WG A0 report. This model will be adapted for determining safety requirements at the early concept design stages in the railway business.

• Journal of Applied Reliability
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• v.10 no.2
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• pp.107-122
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• 2010

Functional safety is the part of the overall safety of a system that depends on the system or equipment operating correctly in response to its inputs, including the safe management of likely operator errors, hardware failures, systematic failures, and environmental changes. One of the essential concepts of functional safety is Safety Integrity Level(SIL). It is defined as a relative level of risk-reduction provided by a safety function, or to specify a target level of risk reduction. In this paper, each element of SIL assessment will be defined. Based on each element, specific process of SIL selection will be established by using flowchart. The flowchart provides a SIL assessment guideline for functional safety engineers. The proposed theory will be verified by applying to a oil refining plant for SIL assessment.

• Journal of the Korean Society for Railway
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• v.14 no.2
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• pp.121-129
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• 2011

This paper presents the methods to acquire the Safety Certificate from Independent Safety Assessment based on the IEC or EN standard which is commonly applied to railway system for Automatic Train Protection (ATP) system in accordance with ERTMS/ETCS Level 1 system. This also shows approach methods and relative activities for project lifecycle to accomplish and ensure the system requirements of ATP system, RAMS and system quality activities. These kind of activities for quality assurance of ATP system to obtain Safety Certificate could improve the quality of domestic railway system based on On-Board system of ERTMS/ETCS Level 1 and also contribute to the growth of railway business.

• Journal of the Korean Society for Railway
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• v.14 no.5
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• pp.416-424
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• 2011

The recent development of USN (Ubiquitous Sensor Network) technology has broadened its applications to many fields of industry. The USN technology enables the system to monitor and control the status of distributed sensor nodes based on the low-powered communications. Applying the USN in the train control domain, the operational efficiency can be enhanced, where the reliability and the safety of the system are the key challenges. This paper suggests the system design for evaluating and improving the reliability and safety of the gateway, which is a USN component that manages the radio network among the sensors and collects the information from them. For this purpose, the reliability and the level of safety integrity of a general gateway have been predicted quantitatively and the supplementary design has been proposed for the selected week points. The verification on the reliability and the safety of the improved gateway according to the related standards has been followed. With the results of the study, the applicability of USN gateway for train control systems has been reviewed.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.4
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• pp.743-755
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• 2013

In recent years, the malicious apps with malicious code in normal apps are increasingly redistributed in Android market, which may incur various problems such as the leakage of authentication information and transaction information and fraudulent transactions when banking apps to process the financial transactions are exposed to such attacks. Thus the financial authorities established the laws and regulations as an countermeasures against those problems and domestic banks provide the integrity verification functions in their banking apps, yet its reliability has not been verified because the studies of the safety of the corresponding functions have seldom been conducted. Thus this study suggests the vulnerabilities of the integrity verification functions of banking apps by using Android reverse engineering analysis techniques. In case the suggested vulnerabilities are exploited, the integrity verification functions of banking apps are likely to be bypassed, which will facilitate malicious code inserting attacks through repackaging and its risk is very high as proved in a test of this study. Furthermore this study suggests the specific solutions to those vulnerabilities, which will contribute to improving the security level of smartphone financial transaction environment against the application forgery attacks.

• Journal of the Korean Society for Railway
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• v.13 no.4
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• pp.412-418
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• 2010

This paper presents the methods to acquire the Safety Certificate from Independent Safety Assessment based on the IEC standard62279 which is commonly applied to railway system for Automatic Train Control(ATC) system in accordance with Urban Maglev project. This also shows approach methods and relative activities for project life- cycle to accomplish and ensure the system requirements of ATC system, RAMS and S/W quality activities. Furthermore, the key tasks conducted with ISA are noted in detail. These kind of activities for software quality of ATC system to obtain S afety Certificate could be a CASE model to improve the quality of domestic railway system and products, and also contribute to the growth of railway business and toward the achievement of overseas' railway signaling markets.

• Journal of the Korea Society of Computer and Information
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• v.15 no.5
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• pp.113-124
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• 2010

In this study, the hybrid authorization quotation technique is based on the device ID for the integrity of the source region guarantee of user certificate, in order to improve the convenience and security for user in the hybrid PKI certificate Mechanism for authentication. The feature of the model in which it is presented from this paper is 5. First, because the user can select the policy himself in which it matches with each authentication situation and security level, the convenience can be improved. Second, the integrity of the source region of the user certificate can be guaranteed through the comparison of the DLDI Key, that is the hash-value of the device ID. Third, the security can be improved by continuously changing an encoding, and the value of the key in which it decodes through the EOTP Key. Fourth, the index value is added to a certificate, and the storage of a certificate is possible at the Multi-Device. Fifth, since the addi the inan aratus for the integrity of the source region guarantee of a certificate is not needed, the authentication process time can be reduced and the computational load of the certificate server can be reduced also.