• 한국철도학회논문집
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• 제8권4호
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• pp.354-360
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• 2005

The railway track and the substructures constructed in the field test section of Kyongbu High Speed Line are the structures for HSL, for the first time designed and constructed by domestic technical group. It is very important to verify the local design criteria and specifications for these structures and also to assure the recordings for vibration or deflection produced on the essential parts of the structures. The study to verify the high-speed railway track performance and to ensure the run in safety on the track in curved section during the KTX run. Finally, the conclusion are drawn as follows. The measuring values of the deflection effort of the rail and displacement for verifying the track performance in the field test section of Kyoungbu HSL satisfy the criteria of the foreign countries (Japan and Germany). The measured value for the wheel load and the presumed value show the consistent tendency. The wheel loads of the exterior and interior of the rails at the speed superior to 300km/h are measured same. Finally, the comparison between the theoretical value presented during the verification of the derailment to evaluate the safety of the train run at the time of the detailed design of the track and the measured value in the field shows that the correct design of track structure was applied.

• Journal of Computing Science and Engineering
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• 제10권3호
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• pp.75-84
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• 2016

Medical cyber-physical systems (MCPS) integrate sensors, actuators, and software to improve patient safety and quality of healthcare. These systems introduce major challenges to safety analysis because the patient's physiology is complex, nonlinear, unobservable, and uncertain. To cope with the challenge that unidentified physiological parameters may exhibit short-term variances in certain clinical scenarios, we propose a novel run-time predictive safety monitoring technique that leverages a maximal model coupled with online training of a computational virtual subject (CVS) set. The proposed monitor predicts safety-critical events at run-time using only clinically available measurements. We apply the technique to a surgical glucose control case study. Evaluation on retrospective real clinical data shows that the algorithm achieves 96% sensitivity with a low average false alarm rate of 0.5 false alarm per surgery.

• 한국소음진동공학회논문집
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• 제25권4호
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• pp.247-254
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• 2015

Ride comfort is one of the major factors in evaluating the performance of the vehicle. Tire is closely related to the ride comfort of the vehicle as the only parts in contact with the road surface directly. Vertical stiffness which is one of the parameters to evaluate the tire performance is great influence on the ride comfort. In general, the lower the vertical stiffness, the ride comfort is improved. Research for improving the ride comfort has been mainly carried out by optimizing the shape of the pneumatic tire. However, demand for safety of the vehicle has been increased recently such as a run-flat tire which is effective in safety improvement. But a run-flat tire have trouble in practical use because of poor ride comfort than general tire. Therefore, In this paper, the research was carried out for improving the ride comfort through the optimization of the SIR shape inside a run-flat tire. Meta-model was generated by using the design of experiment and it was able to reduce the time for the finite element analysis of optimization. In addition, Shape optimization for improving the ride comfort was performed by using the genetic algorithm which is one of the global optimization techniques.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.396-413
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• 2017

Dynamically checking the integrity of software at run-time is always a hot and difficult spot for trusted computing. Control-flow integrity is a basic and important safety property of software integrity. Many classic and emerging security attacks who introduce illegal control-flow to applications can cause unpredictable behaviors of computer-based systems. In this paper, we present a software-based approach to checking violation of control flow integrity at run-time. This paper proposes a high-performance and low-overhead software control flow checking solution, control flow checking at virtual edges (CFCVE). CFCVE assigns a unique signature to each basic block and then inserts a virtual vertex into each edge at compile time. This together with insertion of signature updating instructions and checking instructions into corresponding vertexes and virtual vertexes. Control flow faults can be detected by comparing the run-time signature with the saved one at compile time. Our experimental results show that CFCVE incurs only 10.61% performance overhead on average for several C benchmark programs and the average undetected error rate is only 9.29%. Compared with previous techniques, CFCVE has the characteristics of both high fault coverage and low memory and performance overhead.

• 대한인간공학회지
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• 제36권5호
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• pp.535-543
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• 2017

Objective: This study was designed to identify factors affecting pilots' +Gz tolerance recovery from +Gz induced exhaustion. Background: +Gz tolerance of pilots has been considered as a crucial factor to fly the modern high performance fighter aircrafts. However, the factors affecting pilots' G-tolerance recovery from +Gz induced exhaustion have not been examined in the acceleration research community. Method: A centrifuge profile consisting of a high +Gz run for pilot's exhaustion and a low +Gz run for pilot's recovery and another high +Gz runs for pilot's second exhaustion was designed. The subjects' +Gz tolerance recovery ratio was measured by ratio of second high +Gz run time to the first high +Gz run time. The subjects' +Gz tolerance recovery rate was measured by dividing the subjects' +Gz tolerance recovery ratio by the low +Gz run time. The subjects' G-tolerance recovery rate was analyzed with respect to the subjects' personal factors including subjects' anthropometric and physiologic characteristics, flight time, flying aircraft type and so on. Results: The subjects' previous three-month flight hours (r=-0.336, p=0.039), six-month flight hours (r=-0.403, p=0.012) and one-year flight hours (r=-0.329, p= 0.044) correlated with the subjects' G-tolerance recovery rate. Conclusion: The subjects' G-tolerance recovery rate is clearly related to the subjects' previous flight hours. However, the subjects' anthropometric and physiologic characteristics do not show any statistically significant correlation with the subjects' G-tolerance recovery rate. Application: This research provides a safety critical insight to aviation community by identifying the factors to affect the gravity-induced loss of consciousness (GLOC) of pilots.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1935-1942
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• 2011

We have tested the developed Korean tilting train in main exisiting commercial line for speed-up on cuve section to achive reduction effects of running time. We have conducted a trial run test to speed-up 30km/h on curves in Gyeongbu line successfully. Normal current train have been operated 110km/h in 600m radius. Yet, tilting train was tested 135km/h(maximum operation line speed) in same sections. We confirmed that the dynamic runing stability of train was safety by regarding wheel load and lateral force.

• 정보과학회 논문지
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• 제42권4호
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• pp.487-495
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• 2015

요즘에는 대부분 정보가 전산화되어 다루어지고 있기 때문에 전산화된 정보의 안전성을 높이는 것이 매우 중요하다. 하지만 코딩 실수로 발생하는 많은 메소드 오용 때문에 소프트웨어 자체가 취약해짐에 따라 정보의 안전성이 위협받을 수 있다. 해킹 공격을 원천적으로 차단하여 정보의 안전성을 높이기 위해 시큐어 코딩 가이드가 제안된 바 있지만, C와 Java 프로그래머를 위주로 작성되었기 때문에 다른 프로그래밍 언어에서는 적용하기 어렵다. 이 논문에서는 다른 프로그래밍 언어에도 사용할 수 있도록 시큐어 코딩 가이드의 규칙을 재분류한다. 구체적으로 행정자치부에서 발표한 C 시큐어 코딩 가이드를 이용하였다. 그리고 이 분류에 따라 구별된 규칙을 새로 제안한 한글 프로그래밍 언어인 새싹에 적용해 보았다. 그 결과 새싹에서는 C 언어 대비 점검해야 할 취약점 규칙의 수가 52% 줄어든 것으로 나타났다.

• 한국항해항만학회지
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• 제30권3호
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• pp.247-251
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• 2006

다양화 개성화로 확산되고 있는 21세기 고도화된 산업사회에 진입하면서 소득수준의 향상과 토요일 휴무제에 따른 여가활용 시간의 증대에 수반하여 수상레저활동의 인구가 증가한 동시에 그 내용은 매우 활동적이다. 종래 여가활동이라고 하면 정적인 옥내활동이 주류였으나, 현시점의 여가활동은 사회발전과 더불어 옥외활동, 나아가서는 스스로 활동하고 경험하는 쪽으로 전개되고 있다. 이러한 관점에서 수상 레저는 안전한 수상활동으로 성취될 수 있는데, 수상레저활동의 급성장으로 인하여 수상안전사고가 심각한 문제로 대두되고 있다. 따라서 수상 레저기구 활동자의 체계적인 안전관리를 위하여 종합적인 육성과 관리대책 마련하고자한 결론은 안전사고를 예방하기위해서는 소양교육을 실시하여야 하며 안전검사 및 등록을 의무화하여 제도권에서 활동하도록 하여야하며 수상레저활동 안전사고에 대한 피해보전을 위해서 보험에 가입할 수 있도록 강력한 제도적 보완장치가 필요하다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.614-620
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• 2011

Railway intelligent transportation systems and related Ministry of Land and rail operating agency's railway informatization planning of information technology, effective through the use of management strategies to establish or run to support the systematic informatization investment that you want to execute work in progress, during and yet the institutional informatization of operations mainly in the form of efficiency is Chinhae. Accordingly, in order to promote the details of the final challenge of providing real-time information and the usefulness of this information collection is clearly for the railway sector by function of the components is necessary to distinguish. In this paper, the details of the plan goals, promoting convenient rail-based real-time information, to promote optimal gohyoeuleul railways, railway safety and comfort, was defined as three. Selection of each goal, because the direction of vision and ITS around the railroad center of road users by highlighting the benefits of the railroad's traffic information center user switching, real-time delivery of information diversity (enhanced content) that can increase the capacity of line train operating systems, enhancing the safety management system introduced in the monitoring system and is a railroad crossing. Because urban railway project in accordance with the goal of decreasing the annual rate of the train support, and the average passenger wait time savings, increased future demand for railway, rail safety, including securing the expected effects may occur.

• 한국시스템다이내믹스연구
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• 제7권1호
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• pp.213-228
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• 2006

This paper reports the results of a study designed to understand and facilitate disaster mitigation for communities located in low frequency/high magnitude earthquake zones. The study is based on a small town located near the New Madrid Fault Zone and is therefore at significant earthquake risk. A system dynamics model describes the variables and policies governing the distribution of building safety over time. Data from this town is used to establish a 25-year baseline. Simulations are run to demonstrate the consequences of different building policies.