Special Report - 블록체인과 DLT 상호운용성 표준 및 기술 동향

이원석,이강찬,Lee, Won-Seok,Lee, Gang-Chan 한국정보통신기술협회 2018 TTA저널 Vol.2018 No.-

정신분열병의 CDH2 유전자 다형성

이원석,김미경,정한용,우성일,권영준,김종우,이희제,Lee, Won Seok,Kim, Mi Kyung,Jung, Han Yong,Woo, Sung Il,Kwon, Young Joon,Kim, Jong Woo,Lee, Hee Je 대한생물정신의학회 2005 생물정신의학 Vol.12 No.1

Objective:There has been increasing evidence that neurodevelopmental dysfunction is involved in the pathophysiology of schizophrenia. Cadherin is known to be one of the important molecules in neurodevelopment. This study was performed to examine the relationship between T816C polymorphism of CDH2 gene and schizophrenia. Methods:Genoytypes of T816C polymorphism of CDH2 gene were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 156 Korea patents with schizophrenia and 170 controls. Results:No difference was found between the patients with schizophrenia and the controls in genotype and allele frequencies of T816C polymorphism of CDH2 gene. Conclusion:The results of this study do not support an association between T816C polymorphism of CDH2 gene and schizophrenia. However, it is necessary to investigate other polymorphic regions of CDH2 in schizophrenia.

20 MHz 의료용 고주파 선형 배열 초음파 트랜스듀서의 설계 및 제작

이원석,노용래,Lee, Wonseok,Roh, Yongrae 한국음향학회 2016 韓國音響學會誌 Vol.35 No.6

In this work, a medical linear array ultrasonic transducer working in the range of 20 MHz has been developed for high-resolution ultrasonic imaging. After devising the structure of the transducer suitable for the transmission of high-frequency waves, we optimized the dimension of constituent components. Then, the process to fabricate the transducer was developed to realize the designed structure, and a prototype of the transducer was fabricated and characterized. The center frequency of the fabricated transducer was measured to be 19 MHz, and the fractional bandwidth to be 84.5 %, and the standard deviation of the sensitivity over the entire channels to be 0.74 dB. These measurement results showed good agreement with design data, which confirmed the validity of the high frequency ultrasonic transducer structure developed in this work. It was confirmed that the developed transducer with new structure had wider frequency bandwidth and uniform sensitivity than a conventional 20 MHz transducer. 본 연구에서는 고분해능 초음파 영상 획득이 가능한 20 MHz 대역의 의료용 초음파 선형 배열 트랜스듀서를 개발하였다. 먼저 고주파 음파의 전파가 용이한 트랜스듀서의 구조를 고안한 후, 구성소자의 최적치수를 도출하였다. 이후 설계에 따라 트랜스듀서의 제작공정을 개발하고, 트랜스듀서 시편의 제작 및 평가를 수행하였다. 제작된 초음파 트랜스듀서는 중심주파수가 19 MHz이고, 비대역폭이 84.5 %, 감도의 표준편차가 0.74 dB로 측정되었다. 측정 결과는 설계 결과와 잘 일치하였으며, 이에 의해 본 연구에서 개발한 고주파 초음파 트랜스듀서 구조의 타당성을 검증하였다. 개발된 트랜스듀서는 새로운 구조에 의해 기존의 20 MHz 트랜스듀서에 비해 더 넓은 주파수 대역폭과 균일한 감도를 가지는 것으로 확인되었다.

표준·시험인증 기술 동향 - W3C 핵심 표준 개발 동향

이원석,이승윤,Lee, Won-Seok,Lee, Seung-Yun 한국정보통신기술협회 2016 TTA저널 Vol.165 No.-

MoO₃/camphene 슬러리의 동결건조 및 수소환원에 의한 Mo 다공체 제조

이원석,오승탁,Lee, Wonsuk,Oh, Sung-Tag 한국분말야금학회 2012 한국분말재료학회지 (KPMI) Vol.19 No.6

In order to fabricate the porous Mo with controlled pore characteristics, unique processing by using $MoO_3$ powder as the source and camphene as the sublimable material is introduced. Camphene-based 15 vol% $MoO_3$ slurries, prepared by milling at $50^{\circ}C$ with a small amount of dispersant, were frozen at $-25^{\circ}C$. Pores were generated subsequently by sublimation of the camphene during drying in air for 48 h. The green body was hydrogen-reduced at $750^{\circ}C$, and sintered at $1000-1100^{\circ}C$ for 1 h. After heat treatment in hydrogen atmosphere, $MoO_3$ powders were completely converted to metallic W without any reaction phases. The sintered samples showed large pores with the size of about $150{\mu}m$ which were aligned parallel to the camphene growth direction. Also, the internal wall of large pores and near bottom part of specimen had relatively small pores due to the difference in the camphene growth rate during freezing process. The size of small pores was decreased with increase in sintering temperature, while that of large pores was unchanged. The results are strongly suggested that the porous metal with required pore characteristics can be successfully fabricated by freeze-drying process using metal oxide powders.

Special Report - W3C 오토모티브 웹(Automotive Web) 표준화 현황

이원석,이승윤,Lee, Won-Seok,Lee, Seung-Yun 한국정보통신기술협회 2016 TTA저널 Vol.166 No.-

A Study on Cerebral Ischemia-Reperfusion Injury: Involvement of Platelet-Activating Factor

이원석,임병용,홍기환,Lee, Won-Suk,Rhim, Byung-Yong,Hong, Ki-Whan The Korean Society of Pharmacology 1993 대한약리학잡지 Vol.29 No.1

뇌의 허혈-재관류 손상에 있어서 혈소판 활성인자 (PAF, platelet activating factor)의 관련을 증명하기 위하여 흰쥐와 생쥐에서 양측 총경동맥을 10분간 결찰하고 그후 6시간동안 재관류시켜 허혈-재관류 손상을 야기시켰다. 생쥐에 PAF 길항제인 BN52021과 CV6209 (각각 1 mg/kg, i.p.)를 총경동맥결찰 10분전 또는 재관류 시작 1시간 후에 투여시 McGram stroke index는 심하게 억제되었다. 흰쥐와 생쥐에서 뇌허혈-재관류에 의한 뇌수분함량의 증가는 BN52021 또는 CV6209 전처치에 의하여 유의하게 억제되었다. BN52021 전처치는 허혈 후의 혈압변동을 개선시켰을 뿐만 아니라 뇌연막동맥의 확장지연에 대하여도 효과가 있었다. 이러한 실험결과로 보아 PAF가 뇌허혈-재관류 손상의 발생에 내인성 인자로서 중요한 역할을 하는 것으로 사료된다. 나아가 PAF 길항제가 뇌허혈후의 병리학적 후휴증의 개선 내지는 예방에 사용 될 수 있을 것으로 기대된다. To elucidate involvement of platelet-activating factor (PAF) in cerebral ischemia-reperfusion injury, male Sprague-Dawley rats and albino mice of either sex were subjected to a 10-min bilateral carotid artery occlusion and 6-hr recirculation. The McGraw stroke index in mice was markedly inhibited by PAF antagonists, BN 52021 and CV 6209 (1 mg/kg, i.p., each) When they were administered 10 min before bilateral carotid artery occlusion or 1 hr after reperfusion. The increases in brain water content were significantly attenuated by treatment with BN 52021 or CV 6209 in both animals. BN 52021 exhibited a significant improvement in the postischemic blood pressure change in association with a beneficial effect on the delayed dilatation of pial arterioles after 10 min of ischemia. Thus it is suggested that PAF plays an important role as an endogenous mediator in development of cerebral ischemia-reperfusion injury, and further, specific antagonists to PAF will be able to prevent or reverse the pathological sequelae of cerebral ischemia.

1.75D 초음파 트랜스듀서의 설계 및 제작

이원석,노용래,Lee, Wonseok,Roh, Yongrae 한국음향학회 2013 韓國音響學會誌 Vol.32 No.3

In this paper, a $64{\times}8$ channel 1.75D ultrasonic transducer made of piezoelectric single crystals was designed, fabricated, and evaluated. First, a structure of the transducer was selected to be suitable for wiring on a planar array, and components were fabricated to correspond to the structure. Detailed structure of the transducer was designed through finite element analyses. As main performance factors, the crosstalk between neighboring elements was reduced through the control of kerf width and material, and desired frequency bandwidth of the transducer was achieved by designing the optimal thicknesses of the piezoelectric single crystal and matching layers. An experimental prototype of the transducer was fabricated following the design, and its performance was measured. Then the experimental results were compared with those of the finite element analysis, which led to the evaluation of the transducer developed in this work. 본 논문에서는 압전단결정으로 구성된 $64{\times}8$ 채널 1.75D 초음파 트랜스듀서의 설계, 제작 및 평가를 하였다. 우선, 평면 배열된 독립소자에 전기적 연결이 가능한 트랜스듀서의 구조를 선정하고 구조에 맞게 구성소자를 제작하였다. 그리고 유한요소 해석을 통해 트랜스듀서의 세부 구조를 설계하였다. 트랜스듀서의 주요 성능요소로서, 치폭의 너비와 재료를 조절하여 소자간 상호간섭의 영향을 줄이고, 압전단결정 및 정합층의 최적 두께를 설계함으로써 트랜스듀서의 원하는 대역폭을 구현하였다. 설계에 맞게 트랜스듀서 시편을 제작하고 실험적으로 그 특성을 측정한 후, 그 결과를 유한요소 해석 결과와 비교함으로써 개발된 트랜스듀서의 성능을 평가하였다.

Special Theme_모바일웹과 스마트폰 - HTML5와 모바일웹

이원석,Lee, Won-Seok 한국정보통신기술협회 2010 TTA저널 Vol.128 No.-

WS-ECA 프레임워크 설계 및 구현

이원석,신동민,이규철,Lee, Won-Suk,Shin, Dong-Min,Lee, Kyu-Chul 한국정보통신학회 2007 한국정보통신학회논문지 Vol.11 No.8

유비쿼터스 환경으로 발전하면서 이종의 디바이스들을 자연스럽게 연동시킬 수 있는 기술에 대한 요구가 크게 증가하고 있으며, 이를 해결하기 위한 하나의 대안으로 웹서비스가 주목받고 있다. 최근 디바이스 연동을 선언적인 ECA(Event-Condition-Action) 룰로 정의하고 이를 이용하여 디바이스 연동을 수행할 수 있는 웹서비스 기반의 WS-ECA(Web Services-ECA) 프레임워크가 제안되었다. 본 논문에서는 WS-ECA 프레임워크에 대한 구체적인 모듈 단위의 설계 부분을 제안하고, 이를 기반으로 WS-ECA 프레임워크를 구현하였다. Requirement of coordination among heterogeneous devices is significantly increasing to meet the challenges presented by the evolvement of the ubiquitous computing environment. The web services technology is receiving much attention as a promising solution to support the inter-operability between such heterogeneous devices by means of well-defined protocol. Recenlty, ECA(Event-Condition-Action) rule-based framework for coordinating devices is proposed, which is called WS-ECA(Web Services-ECA) framework In this paper we propose a specific design and an implementation methodology for WS-ECA framework.