• The Korean Journal of Malacology
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• v.24 no.1
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• pp.59-66
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• 2008

The ark shell, Scapharca broughtonii were collected from the Jinhae bay in Kyungnam, Korea from April 2006 to October 2007. To assess how much they have tolerance against hypoxia under the compound condition of temperature and salinity, survivorship, oxygen consumption rate and external features of Scapharca broughtonii were measured, The 7 days-$LC_{50}$ of dissolved oxygen (DO) for Scapharca broughtonii at $15^{\circ}C$-ordinary sea water and $26{\pm}1$ psu was 1.98mg/L (confidence limit: 1,45-2.39 mg/L) and 2.63mg/L (confidence limit: 1.76-3.37mg/L) respectively. Whereas 3 days-$LC_{50}$ at $25^{\circ}C$-ordinary sea water was 3.89mg/L (confidence limit: 3.36-4.55 mg/L) and 4 days-$LC_{50}$ at $25^{\circ}C-26{\pm}1$ psu was 3.74mg/L (confidence limit: 3.19-4,43 mg/L). Oxygen consumption rate with each experimental group was decreased during the period exposed to hypoxia. To recovery, they were replaced to ordinary and oxygen consumption rate was increased a little, but all died, The color of the umbo of shell in Scapharca broughtonii was changed dark during hypoxia. These data will provide important fundamental information for examining the causes of mass mortality of shellfish in the summer.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.4
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• pp.393-400
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• 2011

In this study, a procedure for the inverse estimation of the fatigue life parameters of springs which utilize the field fatigue life test data is proposed to replace real test with the FEA on fatigue life prediction. The Bayesian approach is employed, in which the posterior distributions of the parameters are determined conditional on the accumulated life data that are routinely obtained from the regular tests. In order to obtain the accurate samples from the distributions, the Markov chain Monte Carlo (MCMC) technique is employed. The distributions of the parameters are used in the FEA for predicting the fatigue life in the form of a predictive interval. The results show that the actual fatigue life data are found well within the posterior predictive distributions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.1045-1050
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• 2010

Fatigue analysis and lifetime evaluation are very important in design procedure for assuring the safety and reliability of rubber components for mechanical systems. Till recently, the technology for the design, analysis, and evaluation of rubber products was required to manufacture rubber products with high quality, fidelity, and reliability. However, in the rubber-manufacturing companies in Korea, the processes of compound mixing, manufacturing of rubber products, and improvement of rubber properties are based on the trial-and-error method and experience. The objectives of this study are to establish methods for testing rubber materials, to develop a database of the properties of rubber materials, to evaluate the performance of rubber components, and to develop a system for predicting fatigue life. A method to predict fatigue-life of rubber components was proposed; in this method, the finite-element analysis and fatigue damage parameter as determined from a fatigue test are incorporated.

• Journal of the Korean Institute of Gas
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• v.21 no.3
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• pp.39-45
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• 2017

The LNG storage tank as core facility of LNG industry is mainly composed of the inner tank of nikel 9% steel and the outer tank of prestressed concrete. To respond proactively increased risk of structure performance deterioration due to fatigue of the inner tank and durability reduction of the outer tank, life evaluation program for LNG storage tank is needed. In this study, life evaluation program for LNG storage tank was developed to assess fatigue of the inner tank and durability(carbonation and chloride attack) of the outer tank. By defining the main three scenarios in the inner tank, the fatigue life analysis is conducted from structural analysis and Miner's damage rule. Carbonation progress of the outer tank is predicted according to thickness of cover concrete by using carbon dioxide contents and data of penetration depth. To consider a variety of input conditions and a reliability in results of chloride attack, the evaluation of choride attack for the outer tank is constructed through Life-365 program of open source.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.631-633
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• 2001

인터넷의 대중화로 컴퓨터 네트워크의 사용이 보편화 되었고, 그룹통신 기법이 화상회의 등 많은 응용분야에서 활용되고 있다. 분산 실시간 시스템에서 피를 통신의 신뢰성을 보장하는 일은 매우 중요하다. 또, 그룹 통신에서 효과적으로 그룹을 관리할 필요가 있고, 현재 실시간 환경에서의 그룹통신은 네트워크의 부하 때문에 생기는 패킷의 손실과 노드의 고장 같은 여러 가지 문제점들을 가지고 있다. 본 논문에서는 이러한 문제점들을 개선시켜 보고자 고장이 발생했을 때에도 그를 변경을 가능하게 하는 분산 실시간 환경을 위한 신뢰성 있는 그룹관리기법을 제안하고, 실시간 시뮬레이션을 통해 제안된 기법을 평가한다.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.06a
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• pp.348-352
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• 2002

자동차의 바킹류 및 방음고무는 자동차의 소음 및 오일등 각종유액의 누설의 대부분을 차지하고 있기 때문에 자동차의 생명연장에 필수적인 부품이다. 현재까지 선별시스템의 고가로 인해서 대부분의 선별이 수작업으로 이루어져 왔다. 이는 피로누적에 의한 오류가 많을 수 있고 제품의 신뢰도에 치명적일 수 있다. 선별 시스템을 완전 자동화 하므로서 공정개선 및 인건비 절감, 신뢰도 개선의 효과가 있다. 이 연구는 앞으로 이들 고무 제품의 검사 장비의 자동화를 이루는 기반을 만든다고 할 수 있다. 특히 컨베이어 벨트를 타고 흐르는 부품을 제어하는 부분과, 움직이는 물체의 타이밍을 설계하여 영상획득하여 내부 불량 제품에 DCT를 적용하여 선별시스템을 만들었다.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.05c
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• pp.240-244
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• 2002

자동차의 바킹류 및 방음고무는 자동차의 소음 및 오일둥 각종유액의 누설의 대부분을 차지하고 있기 때문에 자동차의 생명연장에 필수적인 부품이다. 현재까지 선별시스템의 고가로 인해서 대부분의 선별이 수작업으로 이루어져 왔다. 이는 피로누적에 의한 오류가 많을 수 있고 제품의 신뢰도에 치명적일 수 있다. 선별 시스템을 완전 자동화 하므로서 공정개선 및 인건비 절감, 신뢰도 개선의 효과가 있다. 이 연구는 앞으로 이들 고무 제품의 검사 장비의 자동화를 이루는 기반을 만든다고 할 수 있다. 특히 컨베이어 벨트를 타고 흐르는 부품을 제어하는 부분과, 움직이는 물체의 타이밍을 설계하여 영상획득하여 내부 불량 제품에 DCT를 적용하여 선별시스템을 만들었다.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.1
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• pp.29-33
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• 2018

Flexible electronics must be stable under various deformations such as bending, folding, and rolling. The reliability of ITO (Indium Tin Oxide) film used widely as a transparent electrode for flexible electronics has been studied using rolling fatigue test and bending test. During repeated rolling deformations, the electrical resistance was in-situ measured with different number of rotation. During rolling fatigue test, the electrical resistance of ITO film was significantly increased with increasing the number of rotation. As the stress state of ITO film is different according to the relative position of ITO and substrate, the rolling fatigue test was investigated under both outer and inner bending conditions. Inner rolling fatigue test showed superior electrical stability because the crack nucleation and propagation were retarded under compressive stress state.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.46-49
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• 2004

The spider of a drum washing machine receives the repeated fatigue loadings during laundering. Although the spider is designed statically safely, it often happens fatigue failure. Therefore it requires the safe design for fatigue and needs the prediction of quantitative fatigue life. The S-N diagram for a spider material is developed by fatigue test and statistical analysis. The stresses are measured directly from strain gages on the spider. To predict the fatigue life of spider, the rainflow counting method and Miner's rule are used. The data for fatigue life are analyzed statistically. From these data, reliability estimation for fatigue life can be done and also, equivalent fatigue life can be obtained. It will be applied to make and improve to a short period for design and prototype test.

• Proceedings of the KSRS Conference
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• 2009.03a
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• pp.22-25
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• 2009

본 논문은 기 구축된 환경부의 중분류 토지피복도를 올해 KOMPSAT-2 화상으로 갱신하기 위한 예비연구에서 분류결과의 정확도 평가를 중점적으로 나타낸다. KOMPSAT-2 화상기반의 중분류 토지피복도는 객체지향의 분류기법을 이용하였고, 경계선 수정의 경우 반자동 기법에 의해 제작되었다. 계통표집과 임의표집에 의한 Kappa 분석에서 계통 표집의 KHAT값은 0.81, 임의표집의 KHAT값은 0.89를 각각 가지므로 거의 완벽의 일치성을 표시한다. 따라서 전술한 지도화 방법을 통해 제작된 KOMPSAT-2 화상의 중분류 토지피복도는 이용자에게 토지피복정보의 신뢰성도 함께 제공한다.