• Journal of applied mathematics & informatics
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• 제8권1호
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• pp.59-69
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• 2001

The paper deals with the interaction between three Griffith cracks propagating under antiplane shear stress at the interface of two dissimilar infinite elastic half-spaces. The Fourier transform technique is used to reduce the elastodynamic problem to the solution of a set of integral equations which has been solved by using the finite Hilbert transform technique and Cooke’s result. The analytical expressions for the stress intensity factors at the crack tips are obtained. Numerical values of the interaction efect have been computed for and results show that interaction effects are either shielding or amplification depending on the location of each crack with respect to other and crack tip spacing. AMS Mathematics Subject Classification : 73M25.

• 한국안전학회지
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• 제24권6호
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• pp.86-92
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• 2009

In the safety check of gravity dams at earthquake, there have been two types of analysis conducted simultaneously; one is stability analysis and the other stress analysis. But those are essentially the same calculation other than the former considers the dams rigid, while the latter considers the dams' dynamic characteristics which results in the amplification of response acceleration on the upper part of dam body. In this paper, the identity of those two methods is verified by example calculation in terms of stability check of gravity dam. It can be concluded that if stress analysis were performed, stability check of gravity dam could be accomplished with the results from stress analysis, removing unnecessary present dual calculation practice.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4215-4220
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• 2011

This study introduces a new concept for a simple, efficient and cheap sensitivity amplification of a Quartz Crystal Microbalance (QCM) based immunosensor system for the detection of tumor necrosis factor-alpha (TNF-${\alpha}$, TNF) by using an in-built magnetic system. The frequency shift due to the applied magnetic field was successfully observed on magnetic particles labeled detection antibodies, anti-human TNF-${\alpha}$, which were bound to the immunologically captured TNF-${\alpha}$ on the gold coated quartz crystals. In the present system, the magnitude of frequency shift depends on both the strength of magnetic field and the amount of target antigen applied. Significant signal amplification was observed when the additional built-in residual stress generated by the modified magnetic particles under the magnetic field applied. Used in conjunction with a sandwich type non-competitive immunoassay format, the lower detection limit was calculated to be 25 $ngmL^{-1}$ and showed good linearity up to TNF-${\alpha}$ concentrations as high as 2.0 ${\mu}gmL^{-1}$. The sensitivity, most importantly, was improved up to 4.3 times compared with the same QCM system which was used only an antigen-antibody binding without additional magnetic amplification.

• 한국해안해양공학회지
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• 제10권1호
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• pp.18-26
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• 1998

금강하구에서 대규모 공사의 영향으로 인한 수동역학적 변화를 해석하기 위하여, 2차원 유한요소 수동역학모형을 적용하었다. 수치모형을 조석과 조류번화 해석에 적용한 결과 금강하구둑의 수문이 열렸을 때와 eke혔을 때는 조석체계가 급격히 변화되어 M$_2$, 분조가 각각 군산내항에서 17 cm 및 6 cm 확폭되고, 군산외항에서는 5 cm 및 3 cm 확폭되는 것을 알 수 있었다. 연차별 단계별로 진척되는 공사로 인한 조류와 해저 퇴적성향의 변화결과는 도류제 축조로 조류속이 증가되는 것이 뚜렷하게 나타났으며, 금강하구역의 동적평형을 이루는 해저마찰응력은 0.4N/$m^2$로 분석되었다. 일대해역의 퇴적율 R은 최대마찰응력(equation omitted)와 상관이 있으며 R=-0.37-0.40 ln $\tau$의 관계로 설명된다.

• 동의신경정신과학회지
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• 제22권3호
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• pp.23-42
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• 2011

Objectives : The purpose of this study was to investigate the difference of somatization psychological mechanism among Sasang constitution. Methods : Subjects were seventy four students of Won-Kwang university responded the questionnaire. We evaulated the subjects using Minnesota Questionnaire for the Sasang Constitution Classification II(QSCC II), Multiphasic Personality Inventory-2(MMPI-2), 20-item Toronto Alexithymia Scale (TAS-20), Somato-Sensory Amplification Scale(SSAS), Symptom Interpretation Questionnaire(SIQ) and The Ways of Stress Coping Questionnaire(SCQ). Results : From the results of Clinical scale of MMPI-2, the scores of 2nd, 9th, 10th scales was significantly difference. In Lesser Yin group 10th score was the significantly highest of the others, 1st, 3rd, 6th, 7th, 8th score were the highest but not significant. and From the results of PSY-5 scale(The Personality Psychopathology Five scale) of MMPI-2, In Lesser Yin goup, INTR(Introversion/Low Positive Emotion) score was significantly highest, PSYC(psychoticism), NEGE (Negative Emotionality/Neuroticism) was higher than the others. In TAS-20K, SSAS, SIQ and SCQ Lesser Yin group was not significantly difference. but Lesser Yin group had the tendency of difficulty describing feelings and externally oriented thinking and higher score in physical and psychological interpretation. We observed generally lower levels of stress coping strategy scores than the others. Conclusions : These results showed that Lesser Yin group tend to somatization compared other constitution.

• 한국정밀공학회지
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• 제10권3호
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• pp.69-80
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• 1993

It is important to prevent roll failure in hot rolling process for reducing maintenance coat and production loss. Roll material and rolling conditions such as the roll force and torque have been intensively investigated to overcome the roll failures. In this study, a computer roll life prediction system under working condition is developed and evaluated on IBM-PC level. The system is composed and fatigue estimation models which are stress analysis, crack propagation, wear and fatigue estimation. Roll damage can be predicted by calculating the stress anplification, crack depth propagation and fatigue level in the roll using this computer model. The developed system is applied to a work roll in actual hot rolling process for reliability evaluation. Roll failures can be diagnosed and the propriety of current working condition can be determined through roll life prediction simulation.

• 정신신체의학
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• 제29권2호
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• pp.102-110
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• 2021

연구목적 본 연구는 외상후스트레스장애 환자들의 신체증상 지각 특성과 인지적 정서조절전략을 탐색하기 위해 시행하였다. 방 법 본 연구는 2019년 7월 1일부터 2021년 2월 28일까지 48명의 외상후스트레스장애 환자들과 48명의 정상인을 대상으로 시행하였다. 환자군에 대해 임상가용 외상후스트레스장애 척도, 신체감각 증폭 척도, 인지적 정서조절전략 척도, Hamilton 불안 척도를 평가하였고 정상대조군에 대해 신체감각 증폭 척도를 평가하였다. 신체감각 증폭 척도에 대해 집단간 차이를 검증하였고 환자군에서 척도간 상관 관계를 확인하였다. 결 과 신체감각 증폭 정도는 외상후스트레스장애 환자들이 정상인보다 평균적으로 높았으나 유의하지는 않았다. 외상후스트레스장애 환자군에서, 외상후스트레스장애 증상 심각도는 반추, 파국화의 인지적 정서조절전략과 유의한 양의 상관관계를 나타냈고, 신체감각 증폭 정도는 외상후스트레스장애 과각성 증상과 파국화, 타인비난의 부적응적 인지적 정서조절전략과 유의한 양의 상관관계를 보였다. 결 론 외상후스트레스장애 환자들은 반추, 파국화와 같은 부적응적인 인지적 정서조절전략을 가지고 있으며, 신체감각의 증폭은 외상후스트레스 증상 중 과각성 증상 및 파국화, 타인비난의 인지전략과 관련이 있을 것으로 보인다. 또한 반추, 파국화, 타인비난, 신체감각 증폭과 같은 부정적인 인지를 줄여주는 것이 외상후스트레스장애 증상과 신체증상에 도움이 될 수 있을 것이다.

• 한국생산제조학회지
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• 제19권6호
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• pp.852-858
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• 2010

Recently, the high-tech industries, such as aerospace industry, auto industry, and electronics industry, are growing up considerably. Because of that, high machining accuracy and productivity of precision parts have been required. The tooling system is important part in the machining center. HSK tooling system is more suitable than BT tooling system for that of high speed machining center. It is because static stiffness and machining accuracy of HSK tooling system are higher than those of BT tooling system. In this paper, stress distribution characteristics of the HSK tooling System is analyzed according to the spindle speed. In order that, the mechanism and the force amplification principle of HSK tooling system are analyzed. The HSK tooling system is modelled by using a 3D modeling/design program. Then stress distribution characteristics of HSK tooling system are analyzed according to spindle speed by using the finite element analysis.

• 한국컴퓨터정보학회논문지
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• 제16권2호
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• pp.17-23
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• 2011

본 연구에서는 일상생활 속에서의 심전도를 측정하여 HRV(Heart Rate Variability)를 모니터링 하며 스트레스를 추정할 수 있는 시스템을 제안한다. 제안된 무선 생체 측정기 모듈은 전처리필터와 BFP사용으로 잡음은 감소 시키면서 신호의 크기는 증가시키기는 회로를 설계하였고, ECG를 측정하여 R-wave를 추출하고 이를 통한 HRV로 인간의 감성 중 스트레스를 평가하는 알고리즘을 개발하였다. 또한 무선 생체 측정기 시스템은 활동 모니터링을 위해 휴대하기 편한 사각형의 작은 사이즈로 구성되며 측정방법이 간단하여 언제든지 측정이 가능하다. 실험을 통해서 취득한 사용자의 HRV 정보는 스트레스 평가 지수 도출 알고리즘을 통한 스트레스를 추정할 수 있으며 스트레스 부하 프로토콜을 수행 한 전후를 비교 분석하여 많은 파라미터에서 유의미한 차이가 나타났다. 본 연구에서 수행된 실험은 일상생활 중에 심장의 전기 활동을 모니터링 할 수 있는무선 생체측정기를 개발하였으며 이를 이용하여 시간영역 분석 및 주파수 영역 분석을 통하여 스트레스 지수를 평가 할 수 있는 알고리즘 시스템은 건강 모니터링 시스템으로 활용도가 높을 것으로 기대된다.

• 한국자동차공학회논문집
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• 제11권3호
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• pp.209-213
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• 2003

It is advantage of accelerated vibration testing to compress service exposures to operating vibration into a reduced laboratory test by increasing the amplitude or frequency of the applied input excitations. This paper proposes an accelerated test method to estimate the high-cycle fatigue life under random excitation. The method consists of conducting a test with amplified input excitation and extrapolating linearly the lift in the accelerated condition into the real lift in field condition. The extrapolation is carried out applying the high-cycle irregular excitation fatigue theory including the rainflow counting, Miner’s damage accumulation rule, and Goodman’s mean stress correction. As a verification, those estimated lift is compared with that acquired by experiment f3r the simple case of spot welding specimen with good agreement. This testing procedure will provide an useful scheme that can reduce testing period associated with developing time schedule of new product.