• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.45 no.6
• /
• pp.60-66
• /
• 2008

The operating voltage of Li/SOCl2 battery decrease immediately when we give a load battery stored for long time. It is called voltage delay. We cannot rapidly operate equipment at emergence situation because the voltage delays. So we have to overcome voltage delay. We reported the results improved voltage delay in this paper through the control of the carbon cathode forming density. It is the classic method in order to control of voltage delay that is coating polymer in the lithium surface or put in the additive to electrolyte. If the carbon cathode forming density decreases, the operating voltage of battery becomes to increasing because solution resistance of battery reduce.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.6 no.4
• /
• pp.73-79
• /
• 2003

Fatigue test is conducted to see the effect of pre-indentation on the fatigue crack retardation of Al5052-H18 plate. Metallographic observation is introduced to deduce the relationship between fatigue crack retardation and fracture appearance with indentation. The grain size of the specimen becomes smaller with the increase of indentation force and the plastic zone is formed with the decrease of grain size. The fatigue striations are appeared densely as the Indentation force becomes higher. Metallographic observation and fatigue test results show that the indentation force has the limited value in improving fatigue crack retardation. Important point to retard the fatigue crack growth is that the crack growth path should pass through the indented area.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.12 no.5
• /
• pp.42-49
• /
• 2013

In this study, in order to analyze the crack retardation behaviors, effective plastic zone concept was proposed. By use of the proposed concept, crack retardation period, compressive residual stress and variation of effective plastic zone shapes were obtained. The results were compared with those of Willenborg model. Retardation period, compressive residual stress and effective plastic zone size obtained by using effective plastic zone concept were larger then the results obtained by using Willenborg analysis. Effective stress intensity factors obtained by using effective plastic zone concept were smaller then the results obtained by using Willenborg analysis.

• Proceedings of the KSME Conference
• /
• 2001.06a
• /
• pp.597-602
• /
• 2001

A method for the retardation of fatigue crack growth using ring indentation at the vicinity of a crack is examined. Residual stresses near crack tip are evaluated using fracture mechanics approach. The motivation is to develop a simple and effective method for obtaining an increase in fatigue lives to total failure of materials with crack. Fatigue testing of aluminum specimen showed that the retardation effects are observed after the application of the method.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.11a
• /
• pp.928-932
• /
• 1996

Single overload fatigue tests with overload sizes ranging from 50% and 100% have been performed to investing ate the fatigue crack growth retardation behavior. A modified and experimental method of Willenborg's model for prediction of crack growth retardation behavior has been developed, based on evaluations of equivalent plastic zone size (EPZS) changing its size along the overload plastic zone boundary. The minimum crack growth rates of each overload size are linearly decreased with overload size increasing, but fatigue lives extended by single overload are increasing much more unlike the crack growth rates. Comparisons of crack growth behavior predicted by EPZS model and Willenborg model have shown that the EPZS model accounts for overload effects better than Willenborg model. These effects include delayed retardation, large retardation region, minimum crack growth rate, and the increase rate of crack growth rate in the region crack growth rate recovered.

• Proceedings of the KAIS Fall Conference
• /
• 2003.06a
• /
• pp.215-218
• /
• 2003

오늘날 인터넷의 광범위한 보급은 이제 유선을 넘어 무선 이동통신 기술로의 급발전을 가져오게되었고, 실생활에 있어서도 무선단말기를 통한 인터넷 상에서의 정보검색이 시간과 장소에 구애받지 않고 가능하게 되었다. 그러나 무선인터넷의 성장세는 무선 단말기가 가진 자체의 제한과 무선망의 제한으로 인해, 광범위한 보급과 활용만큼 성장이 급속화 되어지지는 못하다. 이러한 무선인터넷의 성장을 가로막는 요인들은 컨텐츠의 부족, 접속시간의 지연, 애플리케이션 미비, 무선인터넷 단말기의 보급지연, 완벽한 보완의 미흡등이다. 본 논문에서는 이러한 제한요인중에서 기존의 유선통신에서 사용되어지는 HTML로 구성된 웹페이지를 무선에서도 보다 효율적으로 이용할 수 있는 방법에 관해 제시함으로서 모바일 컨텐츠 개발의 생산성을 향상시키고 개발기간 및 비용을 단축할 수 있는 웹탐색 변환방법을 시도한다.

• Journal of the Korean Society of Mechanical Technology
• /
• v.13 no.2
• /
• pp.31-37
• /
• 2011

Sheet aluminum alloys have been used in manufacturing of machine structures. In fatigue crack propagation behavior of thin sheet aluminum alloys, it is important that fatigue crack growth rate is affected by crack closure phenomenon. In this work, we analyzed the characteristics of fatigue crack propagation behavior in experiment of constant stress condition for thin sheet Al 2024-T3 alloys, and identified the retardation behavior of crack growth by comparing experimental results of thin and thick plate specimen. We attempt to operate the fatigue life estimating process using the fatigue related material constants from referred fatigue crack propagation analysis. And we analyzed the experimental and prediction results of fatigue life of thin sheet aluminum alloy in order to identify the relation between retardation behavior of fatigue crack growth and crack closure phenomenon.

• Proceedings of the Korea Contents Association Conference
• /
• 2012.05a
• /
• pp.29-30
• /
• 2012

하드웨어 기술이 빠르게 성장함에 따라 임베디드 시스템의 발전이 가속화 되고 있다. 이러한 임베디드 시스템 상에서 논리적이고 신뢰성 있는 처리를 지원해 주기 위해 실시간 운영체제를 도입하게 되었다. 이러한 실시간 운영체제의 인터럽트 처리는 더 높은 우선순위의 인터럽트 서비스 루틴 수행에 의해 현재 발생한 인터럽트가 마스킹 되어 인터럽트 지연시간이 길어질 수 있다. 이러한 경우 시간결정성이 보장되지 않아 실시간성이 저해 된다. 범용 운영체제인 윈도우즈 운영체제의 경우 DPC(Deferred Procesure Call)라는 메커니즘을 이용하여 인터럽트 지연시간을 줄이는데, DPC란 인터럽트에서 보다 덜 중요한 부분을 지연처리호출로 처리하도록 하여 인터럽트의 지연시간을 줄이는 방식으로 이러한 DPC 메커니즘을 국산 실시간 운영체제인 CNU_RTOS상에서 HISR(High Level Interrupt Service Routine)을 이용하여 구현하였다. 본 논문에서는 CNU_RTOS상에서 HISR을 이용하여 구현된 DPC기법을 이용한 인터럽트의 처리 시간과 일반 인터럽트의 처리시간을 비교하여 측정하고 분석한다.

• Applied Biological Chemistry
• /
• v.40 no.6
• /
• pp.541-545
• /
• 1997

This study was conducted to investigate the effect of cocoon silk fibroin hydrolyzate(CSFH) on shelf-life extension of kimchi. CSFH was added in kimchi in the concentration of 0.3%(w/w), 0.6% and 0.9%. Kimchi with CSFH showed higher pH and lower titratable acidity than control and it was supposed that the growth of lactic acid bacteria was inhibited by CSFH. In model system, for complex lactic acid bacteria, CSFH showes antimicrobial activity.

• 건강소식
• /
• v.34 no.8
• /
• pp.14-15
• /
• 2010

거듭 두통을 호소하는 아이에게 "어린애가 무슨 머리가 아프냐?"며 꾀병 부리지 말라는 얼굴을 해서는 안 된다. 아이들의 두통은 그렇게 가벼이 여길 증상이 아니다. 소아 두통은 성인의 두통과 다르며 방치할 경우 아이의 성장지연과 학습장애, 성격변화를 초래할 수 있다.