• 한국자동차공학회논문집
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• 제20권3호
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• pp.52-57
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• 2012

Proper door effort is required for the safety of passenger and pedestrian while securing door operating convenience. 3D finite element analyses for a hybrid door checker were carried out to estimate door checker arm resistance force. And, from the estimated door checker arm resistance force and theoretically calculated self-closing force, door effort was predicted. The analysis results at checker arm peaks showed excellent correlation with the test results. Also, in order to reduce solving time, a modified model with simple spring element was investigated. Finally an equation to easily calculate checker arm resistance force from checker arm shape and spring constant was suggested and its usefulness in early design stage was discussed.

• 한국기계가공학회지
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• 제11권3호
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• pp.86-91
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• 2012

Door effort was calculated for a new door checker with torsion bar spring and integrated checker case by FE analysis. A hybrid checker arm which has peaks and valleys only on the upper surface was adopted to reduce noise in operation and make operation with more distinctive steps. The checker arm was modeled using shell elements to estimate both the longitudinal and the lateral resistance force by checker arm. By combining the checker arm resistance force obtained from analysis and the door self-closing force by the theoretical calculation, door effort was predicted to show the good correlation with test results. In addition the unrolling effect of roller model was investigated and a new roller type for more smooth rolling was studied.

• 한국자동차공학회논문집
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• 제23권4호
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• pp.396-401
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• 2015

A door checker holds a car door at several opening angles and limits the maximum door opening, so that the door does not bump against to passengers. Recently, the performance of door checker becomes more important as the feeling of door opening and closing effects on the quality of a car. However, some of door checkers make squealing noise when they are used for ages, which causes consumer's complaints as well as decreasing commercial value of the product. In this study, after various experiments for the noise, we concluded that the major reasons of the noise are acceleration of wearing and loss of lubricant due to impurities in working parts. Therefore, we developed a new mechanism of door checker which can resolve the major reasons of the noise. The developed mechanism is effective to prevent inflow of impurities and loss of lubricant by locating working parts in the case. We also proved that the developed mechanism does not make any noise after the test of 50,000 times of operations.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.831-832
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• 2009

• 한국자동차공학회논문집
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• 제11권3호
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• pp.131-137
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• 2003

Proper door effort, required force to open or close a vehicle door, is an essential door design factor for the safety of passengers and pedestrians. Section shape of the door checker arm is the most influential design parameter for achieving a door effort design target. In this research. an analysis procedure to predict door effort using a simplified plane strain finite element model wes investigated for two passenger cars, for which mechanism of checker systems were: different. The variation of checker arm force to be required during moving on arm in opening and closing direction was estimated through analysis, and the result was transformed to the door effort with respect to door opening angle by considering door characteristics. Also, the self·closing force due to door weight was theoretically calculated and added to the door effort from checker arm force. Finally the estimated results of door effort were compared with test results.

• 정보보호학회논문지
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• 제29권4호
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• pp.739-751
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• 2019

임베디드 기기의 보안성이 주요한 문제로 부상하고 있다. 관련된 문제 중 특히 공급망 공격은 국가 간의 분쟁으로 이어질 수 있어 심각한 문제로 대두되고 있다. 공급망 공격을 완화하기 위하여 하드웨어 구성요소, 특히 AES와 같은 암호 모듈에 대한 CC(Common Criteria) EAL(Evaluation Assurance Level) 5 이상 고등급 보안성 인증 및 평가가 필요하다. 고등급 보안성 인증 및 평가를 위하여 암호 모듈에 대한 은닉 채널, 즉 백도어를 탐지하는 것이 필요하다. 그러나 기존의 연구로는 암호 모듈 그 중 AES의 비밀 키를 복구시킬 수 있는 정보가 유출되는 백도어를 탐지하지 못하는 한계가 있다. 따라서 본 논문은 기존의 하드웨어 AES 모듈 백도어의 정의를 확장하여 개선시킨 새로운 정의를 제안하고자 한다. 또한, 이 정의를 이용하여 기존 연구가 탐지하지 못했던 백도어를 탐색하는 과정을 제시한다. 이 탐색 과정은 Verilog HDL (Hardware Description Language)로 표현된 AES 모듈을 정형 기법 도구인 모델 체커(Model Checker) NuSMV를 이용하여 검증하는 것으로 백도어를 탐색한다.