• Reproductive and Developmental Biology
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• 제41권2호
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• pp.41-50
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• 2017

Until today, success in germline cells and tissue cryopreservation is limited mainly due to the poor understanding of the complex physiological processes can lead to cell damage during cryopreservation. Germline cells, from both male and female, have unique ability to differentiate into one or more cell lines and thus it becomes a crucial point to store them in subzero temperature with the minimal damage of their functional properties and maximum recovery of unchanged and viable cells when thawed. In the past three decades, a vast research has been performed using various different animal models which in fact have led to development of new methodologies and optimization of older one. However, successful use of animal model has provided the opportunity in research with human germline cells and tissues preservation, but not in all the cases. Therefore, the use of new cryo-protective chemicals and modified protocols have been often found in different groups of researchers based on the types, physical structures, utility and animal species of the specimens to be cryopreserved. This review discusses about the basics of different types of cryopreservation methodologies and commonly used optimized protocols and cryoprotectants for germline cells and tissues preservation.

• Journal of Trauma and Injury
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• 제29권2호
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• pp.47-50
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• 2016

Transcatheter arterial embolization (TAE) for blunt hepatic injury in children is not common and is especially rare after damage control surgery (DCS). We report a successful TAE after DCS on a child for massive bleeding from the left hepatic artery due to a motor vehicle accident. The car (a sport utility vehicle) ran over the chest and abdomen of a 4-year-old boy. On arrival, initial vital signs were as follows: blood pressure, 70/40 mmHg; heart rate, 149/min; temperature, $36.7^{\circ}C$; respiratory rate, 38/min. After resuscitation, computed tomography was done, and a suspicious contrast leakage from a branch of the left hepatic artery and a spleen injury (grade V) were found. TAE was performed successfully after DCS for a liver injury.

• 한국지능시스템학회논문지
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• 제17권4호
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• pp.534-539
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• 2007

본 논문에서는 저압 배선 진단 시스템 개발을 위한 지능형 차단 시스템을 제안한다. 제안된 배선 진단 시스템은 TFDR(Time-Frequency Domain Reflectometry) 알고리즘을 통해 배선이 어떤 상태인지를 보여 주는 시스템이다. 그리고 제안된 진단 시스템으로부터 얻은 신호를 분석하여 이상 종류에 따라 분류하는 시스템을 통해 지능형 차단 시스템을 제안한다. 일반적으로, TFDR을 통해 알아 낼 수 있는 이상의 종류는 damage, open 그리고 short 이다. 각 상황에 대한 효율적인 분류를 위하여 IF-THEN 규칙에 기반 한 분류기가 사용된다. 기존 TFDR이 수행되었던 통신선 케이블의 실험 데이터에 기반 한 실험을 통해 본 제안 내용의 우수성을 보이게 된다.

• 한국산업융합학회 논문집
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• 제25권6_2호
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• pp.1047-1053
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• 2022

The leaf spring for a truck absorbs shocks or vibrations from the road surface while driving with the elastic force of the material and prevents the shock from being transmitted to the vehicle body. It is subjected to cyclic stress, and fatigue fracture occurs frequently. This study analyzes fractured leaf spring from a 25 ton truck that has been operating for about a year. In the fractured portion, which is the origin of crack, inclusions were observed, and fatigue failure was caused by cyclic stress. In the stress calculation and FE analysis, the stress at the center of the leaf spring was obtained to be 54~65% of the yield strength of the base material and damaged material. It is most important to prevent the mixing of impurities in the steel manufacturing for leaf springs. The large stress portion of the leaf spring needs to introduce compressive residual stress by peening etc.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.286-290
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• 2006

합리적인 용수배분 방안을 수립하는 것은 최근 증가일로에 있는 물 분쟁을 해결하는 데에 사전적 해소 차원에서 매우 중요한 의미를 갖는다. 본 연구는 물 부족상황에서의 용수배분을 경제적 효율성과 사회적 효용극대화에 중점을 두었으며 이를 위해 각종 통계자료를 활용하여 물 부족에 따른 피해함수를 산정하였다. 산정된 물부족 피해함수는 용도별로 물 가격이나 생산성 등의 차이가 현격하므로 그대로 비교하는 것은 불가능하다. 따라서 피해함수를 효용함수로 전환하였으며 '한계효용균등의 법칙'을 적용하여 사회적 효용을 극대화하고자 하였다. 이러한 용수배분방법을 한강권역에 적용한 결과, 생활용수의 배분량이 농업 및 공업용수에 비해 상대적으로 크게 산정되었다. 이는 생활용수의 경우 물 부족에 따른 사회적 효용감소가 타 용도에 비해 상대적으로 크다는 것을 나타낸다. 본 연구는 국내의 용수공급 체계상 어려움이 있는 경제학적 용수배분에 대한 하나의 대안을 제공한 것이라 하겠다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.478-481
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• 1991

This paper discusses the principle and structure of instantaneous voltage drop compensator, which protects damage from instantaneous voltage drop in systems such as computer, variable speed drive, high voltage discharge-lamp, magnet switch. When instantaneous voltage drop occurs, control circuits detect it, then produce output voltage the same as normal condition voltage. Instantaneous voltage drop compensator has condenser bank as energy storage component, so system can be made small, light weight compared with UPS. In normal state, utility source transfers power, and in instantaneous voltage drop state, the energy of condenser bank transfers power through inverter, so high efficiency, compact, and especially low cost system can be manufactured.

• 전기학회논문지P
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• 제58권3호
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• pp.257-262
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• 2009

Capacitor is basically used for the power-factor compensation and sometimes as the passive filter to reduce harmonics of nonlinear load. Since the impedance of capacitor is inversely proportional to the frequency. The harmonic current may result in the problems of voltage distortion and resonance. Capacitor has easily fall under by two harmonic components, a nonlinear load and a distorted utility voltage. The amplified harmonic current and voltage may damage power capacitor. Hence the pre-investigation of harmonic is needed before designing and application the power factor for reducing fault rate. In this paper, we analyzed that voltage and current with harmonics components act on the capacitor under the resonance condition. we concluded that both voltage and current harmonics have an bad effect on the capacitor and current harmonics is a bitter rather than effect by voltage harmonics.

• 조명전기설비학회논문지
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• 제16권2호
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• pp.38-44
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• 2002

전력변환기와 같은 비선형 부하의 사용증가는 전력시스템에 고조파를 발생시킨다. 고조파를 포함하는 전류와 전압은 전기설비에 고장과 오동작을 일으키게된다. 위상조정 변압기는 고조파 발생원이 병렬로 설치되어 있는 곳에 설치하면 고조파 문제를 효과적으로 해결할 수 있다. 본 논문에서는 EDSA고조파 분석 프로그램을 사용하여 고조파를 제거하기 위한 위상조정 변압기의 효과를 분석하고 검증하였다.

• 조명전기설비학회논문지
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• 제14권3호
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• pp.81-87
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• 2000

전력변환기와 같은 비선형 부하의 사용증가는 전원 전력설비시스템에 고조파을 발생시킨다. AD/DC 변환설비는 전력시스템에서 중요한 고조파 발생원이 되고 있다. 고조파를 포함하는 전류와 전압은 전기설비에 고장과 오동작등과 같은 나쁜 영향을 미친다. 고조파 문제를 해결하는 일반적인 방법으로는 고조파 필터룹 사용한다. 본 논문에서는 EDSA 고조파 분석 프로그램을 사용하여 고조파를 제거하는 동조필터를 설치하여 그 효고를 검증하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.1433-1437
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• 2010

The deep excavation work in Korean downtown is almost excuted near by existing structures and utility lines because of the diminution of available yard for construction. So, it was required more and more that the accurate control of displacement on the earth retaining system for minimizing the popular complaint and the damage from constructional accident. Automatic monitoring system is adopted in fracture zone for real time monitoring. In addition, Face mapping is carried out on the face of fracture zone according to excavation sequence. As the result of automatic monitoring system and face mapping, we was able to take the necessary reinforcement and changing excavation method within suitable time. This paper is informed about a stability case on the deep rock excavation site with fracture zone in urban area by automatic monitoring system.