인간포배기 배아의 효과적인 유리화 동결법의 개발을 위한 연구

이상민,이주희,이상원,이승민,윤산현,임진호,박흠대,이성구,Lee, Sang-Min,Lee, Ju-Hee,Lee, Sang-Won,Lee, Seoung-Min,Yoon, San-Hyun,Lim, Jin-Ho,Park, Huem-Dai,Lee, Seong-Goo 대한생식의학회 2003 Clinical and Experimental Reproductive Medicine Vol.30 No.3

Objective: The purpose of this study was to evaluate the survival rate of vitrified blastocyst according to the freezing vessels, equilibration time in cryoprotectant and artificial dehydration method. Methods: Human blastocysts were vitrified after loading onto the plastic straw, open-pulled straw (OPS), electron microscopy grid (EM grid) for 1.5 min or 3 min. They also were directly plunged into LN2 within 30sec. For artificial shrinkage of blastocysts, 36 gauge fine needle was pushed at the cellular junction of the trophectoderm into the blstocoele cavity until it shrank without damage of inner cell mass. Results: The survival rate of vitrified blastocysts on plastic straw, OPS, EM grid as freezing vessels were 26.7, 13.0 and 60.5%, respectively. The survival rate of EM grid was significantly higher than that of plastic straw and OPS (p<0.05). For 1.5 min equilibrium, the survival rates of early blastocyst (EB), middle blastocyst (MB) and late blastocyst (LB) were 64.4, 81.0, and 20.0% respectively. For 3 min equilibrium, the survival rates of EB, MB, and LB were 69.9, 50.0 and 57.5% respectively. The survival rates of EB and MB were significantly higher than that of LB in 1.5 min equilibrium group (p<0.05), however, the significance was not observed in 3 min equilibrium groups. In cytoplasmic shrinkage before vitrification, the survival rates of EB, MB and LB were 92.9, 100 and 75.9% respectively. The survival rate of MB was significantly higher than that of LB (p<0.05). The survival rates of vitrified blastocysts by artificial dehydration and slow-frozen blastocysts were not significantly different as 88.9 and 66.7%, respectively. Conclusion: This study showed that the vitrification of human blastocysts using EM grid and artificial dehydration is an effective method. Therefore, these methods would be an useful techniques for blastocyst cryopreservation.

교통조사의 개선방향에 관한 제언

이상민,추상호,Lee, Sang-Min,Chu, Sang-Ho 대한교통학회 2005 교통 기술과 정책 Vol.2 No.4

초등학교 공간계획을 위한 지역유형분류 및 특성분석 -서울·경기 지역을 중심으로-

이상민,Lee, Sang Min 한국교육녹색환경연구원 2003 교육·녹색환경연구 Vol.3 No.2

This study has the purpose for analysis of each region's property in order to plan a elementary school's space according to community property. For this analysis. we used classification method through classification analysis. classification analysis is one of the useful statistical analysis methode for determining each region's policy through classifying regions which have a similar property. On this study, Seoul and Kyongkido is classified by 4 groups and each group has a different community property. Such a analysis is thought of helping establishing the objective. reasonable space-plan through comparative analysis between subjective claim and objective state indicator of each region.

레이저 범프와 대기압 변화에 대한 하드디스크 슬라이더의 부상 특성

이상민,김대은,Lee, Sang-Min,Kim, Dae-Eun 대한기계학회 2000 大韓機械學會論文集A Vol.24 No.10

The performance of slider of a hard disk drive affects the durability of the system. Particularly, the flying ability of the slider is critical in terms of surface damage and head crash. In this work, the take-off characteristics of the slider for various types of laser zone textured bump geometries were investigated. Also, the effect of ambient pressure on the flying characteristics of the slider was experimentally observed. An index of air density which can be used as a parameter for evaluating the flying characteristic is introduced.

학교화장실 계획의 최적화 모델개발 연구

이상민,김성중,맹준호,Lee, Sang Min,Kim, Sung Joong,Meang, Joon Ho 한국교육녹색환경연구원 2009 교육·녹색환경연구 Vol.8 No.2

The toilet in school building is one of most crucial elements for the recent changing face in school design, but the number of toilets and urinals in most school may not be sufficient to meet current needs, especially in the girl's toilet rooms. This study aims to suggest a guideline in designing the toilet in school buildings and propose the optimum area and development of models. The survey for this study is conducted through questionnaires collected and research from 9 schools in Seoul. The results of this study, it is suggested that the number of toilet facilities in school buildings be required by ratio of 0.5 toilets per a class and 1.1 urinal per a class for boy. In case of girls, it is suggested that ratio of 1.6 toilets per a class. Based on the result, it also propose various unit plans for each class block with space such as rest zone, green zone, powder zone etc.

시간 지연과 시변 상관성 제거 필터를 이용한 디지털보청기용 궤환제거 알고리즘

이상민,박영철,정세영,김인영,김선일,Lee, Sang-Min,Park, Young,Jung, Se-Young,Kim, In-Young,Kim, Sun-I 대한전자공학회 2005 電子工學會論文誌-SC (System and control) Vol.42 No.4

In digital hearing aid system, one of the main problems is acoustic feedback which is known as howling because of miniaturization md high-gain amplification. In this paper, we proposed a feedback cancellation algorithm for hearing aid using time delay and time-varying decorrelation filter. The proposed algorithm has a kind of adaptive filter structure, which is combined with time delay and time-varying decorrelation filter to improve feedback cancellation. An all pass filter was implemented as the time-varying decorrelation filter using low frequency modulator. From the result of computer simulation, it is verified that the proposed algorithm has good ability to cancel feedback. 디지털 보청기 시스템에서는 소형화, 고이득 증폭이 요구되는데 이로 인한 문제점 중의 하나가 하울링(howling)이라는 음향의 궤환이다. 본 논문에서는 시간지연과 시변 상관성 제거 필터를 이용하여 보청기에서 사용 가능한 음향 궤환 제거 알고리즘을 제안하였다. 제안한 알고리즘은 적응형 필터 구조를 기본으로 음향 궤환 신호 제거 효과를 증대시키기 위해 시간 지연과 상관성 제거 필터를 삽입하였다. 상관성 제거 필터로 사용된 전대역 통과 필터는 저주파 변조기를 이용하여 시변 특성을 갖도록 구현 하였다. 컴퓨터 시뮬레이션 결과를 통하여 제안한 알고리즘의 궤환 제거 특성이 우수함을 확인하였다.

지르코니아 단일구조 전부도재관과 금속도재관의 파절강도 비교

이상민,정희찬,전영찬,Lee, Sang-Min,Jeong, Hee-Chan,Jeon, Young-Chan 대한치과보철학회 2007 대한치과보철학회지 Vol.45 No.1

Purpose: The purpose of this study was to compare the fracture strength of the zirconia monolithic all-ceramic crowns according to the thickness (0.5mm, 0.8mm, 1.1mm) and metal-ceramic crowns (1.0mm, 1.5mm) Material and method: Twelve crowns for each of 3 zirconia crown groups were fabricated using CAD/CAM system (Kavo, Germany) and twelve crowns for each of 2 metal-ceramic crown groups were made by the conventional method. All crowns were luted to the metal dies using resin cement. Half of the specimens were exposed to thermocycling ($5-55^{\circ}C$, 1 Hz) and cyclic loading (300,000 cycles, 50N). Subsequently, all crowns were mounted on the testing jig in a universal testing machine. The load was directed at the center of crown with perpendicular to the long axis of each specimen until catastrophic failure occurred. Analysis of variance and Tukey multiple comparison test (P<.05) were used for statistical analysis of all groups, and paired t-test (P<.05) was followed for statistical comparison between each groups' fracture load before and after cyclic loading. Results: 1. The fracture strength of the zirconia monolithic crowns and the metal-ceramic crown increased as thickness increased (P<.05). 2. The cyclic loading and thermocycling significantly decreased the fracture strength of the zirconia monolithic crowns (P<.05). 3. The standard deviation of fracture strength of the zirconia monolithic crowns was very low. Conclusion: The fracture strength of the zirconia monolithic crowns for the posterior area tends to be higher with thickness increased and 0.8mm or over in thickness is recommended to have similar or over the fracture strength of metal-ceramic crowns.

난청인을 위한 전화기 음성증폭 및 하울링 억제

이상민,Lee, Sang-Min 대한의용생체공학회 1998 의공학회지 Vol.19 No.6

일반전화기로 통화가 어려운 난청인에게 충분한 수신음량을 공급하기 위해서는 큰 증폭이 필요한데 큰 증폭은 하울링(howling)을 발생시킨다. 본 연구에서는 소리를 크게 증폭하면서 하울링을 억제하는 새로운 방법을 제안하고 이를 적용한 보청전화기를 개발하여 평가하였다. 통화수신 음성은 3개의 밴드로 나뉘어져 각각 독립적으로 증폭되어 난청인의 청력에 알맞게 적합(fitting)된다. 수신음성의 주파수는 카운터에 의하여 시간영역에서 모니터링되는데 카운터부는 비교기를 이용하여 수신 정현파를 구형파로 변환시키고 시간영역에서 구형파 수를 계수함으로써 주파수를 분석하여 하울링이 발행하는가를 판단한다. 전화기는 송수화기 구조가 결정되어 있고 송수신 주파수 범위가 제한되어 있으므로 하울링 또한 일정주파수 범위내 발생하게 된다. 계수기에 의해 하울링이 검출되면 중앙제어부는 해당대역의 증폭도를 빠르게 낮춤으로써 하울링을 억제시킨다. 시험결과 개발전화기는 하울링 없이 40dB 이상 증폭할 수 있으며 중고도 난청인의 어음인지력이 1음절어의 경우는 20%에서 60.8%로, 2음절어의 경우는 28.9%에서 78%로 향상되는 탁월한 개선 효과를 보였다. To provide sufficient sound to the hearing-impaired person(HIP) who have many difficulty in communication with others using general telephone, big amplification is needed. But big amplification can occur howling as a side effect. In this study we developed the new technique of big amplification without howling, manufactured and estimated the new hearing aid telephone. Telephone speech is divided to three frequency band, amplified respectively and fitted to HIP's hearing ability. The telephone speech frequency is monitored by counter in time domain. The counter transfers the sinusoidal sound to rectangular wave using comparator and counts the number of rectangular wave in a certain time period, that is frequency, to monitor the howling. Telephone have microphone and speaker, which are fitted in a rigid structure and frequency band of telephone sound is limited, so howling occurs in the limited frequency band. If the counter notices that howling conditions happen, microprocessor decreases quickly the gain of the related frequency band. The result of test of our new hearing aid telephone showed that we can amplifiy the sound as much as 40dB, which is meaningful level to many HIP, and make HIP increase their perception ability from 20% to 60.8% in 1 syllable test and from 28.9% to 78% in 2 syllable test.

경두개 자기 자극이 인지 기능에 미치는 영향

이상민,채정호,Lee, Sang Min,Chae, Jeong-Ho 대한생물정신의학회 2016 생물정신의학 Vol.23 No.3

Transcranial magnetic stimulation (TMS) is a safe, noninvasive and useful technique for exploring brain function. Especially, for the study of cognition, the technique can modulate a cognitive performance if the targeted area is engaged, because TMS has an effect on cortical network. The effect of TMS can vary depending on the frequency, intensity, and timing of stimulation. In this paper, we review the studies with TMS targeting various regions for evaluation of cognitive function. Cognitive functions, such as attention, working memory, semantic decision, discrimination and social cognition can be improved or deteriorated according to TMS stimulation protocols. Furthermore, potential therapeutic applications of TMS, including therapy in a variety of illness and research into cortical localization, are discussed.

녹색건축 전문가 자격제도 개발 연구

이상민,이승민,Lee, Sang Min,Lee, Seung Min 한국교육녹색환경연구원 2014 교육·녹색환경연구 Vol.13 No.1

In an effort to resolve environmental pollution problems, developed countries enforce green building certification systems. The same is true in Korea. However compared professional accreditation system to certification systems did not systematically in Korea. Therefore, in accordance with development of green building related systems and technology the requirement for foster green building professionals is urgent. Accordingly this study is purposed to analyze and propose that green building professional accreditation system development and operation of the direction. Through data analysis domestic and international green building professional accreditation system for draw a development plan. And then conduct an expert Delphi survey reflected in the survey results to development plan.