Nanogenerators: Fully Rollable Transparent Nanogenerators Based on Graphene Electrodes (Adv. Mater. 19/2010)

Choi, Dukhyun,Choi, Min-Yeol,Choi, Won Mook,Shin, Hyeon-Jin,Park, Hyun-Kyu,Seo, Ju-Seok,Park, Jongbong,Yoon, Seon-Mi,Chae, Seung Jin,Lee, Young Hee,Kim, Sang-Woo,Choi, Jae-Young,Lee, Sang Yoon,Kim, Jo WILEY-VCH Verlag 2010 ADVANCED MATERIALS Vol.22 No.19

<B>Graphic Abstract</B> <P>The cover shows an image of fully rollable transparent nanogenerators synthesized using chemical vapor deposition grown large-scale graphene sheets as transparent electrodes and piezoelectric ZnO nanorod arrays. Sang-Woo Kim, Jae-Young Choi, and co-workers report on p. 2187 the electrical and structural stability of the nanogenerators, with excellent charge scavenging performance under external mechanical loads such as bending and rolling. This study shows that graphene-based nanogenerators are very promising for self-powered rollable transparent device applications. <img src='wiley_img_2010/09359648-2010-22-19-ADMA201090066-content.gif' alt='wiley_img_2010/09359648-2010-22-19-ADMA201090066-content'> </P>

열공형과 비열공형 피질하 혈관성 치매에서 위험인자의 차이에 관한 비교 연구

배희준,정지향,유경호,나덕렬,김상윤,최경규,양동원,손의주,이상도,김재우,박경원,김응규,이재홍,박미영,한일우,함동석,최문성,하충건,최성혜,이애영,이병철,한설희 대한치매학회 2003 Dementia and Neurocognitive Disorders Vol.2 No.2

Backgrounds and Objectives: Vascular dementia is a group of dementing disoders arising from various stroke syndrome. Among these. subcortical ischemic vascular dementia (SIVD) is regarded as a relatively distinct clinical entity. However, MRI patterns of SIVD are not homogenous. In some patients, lacunes are dominant, and in others, subcortical white matter changes are. This study was designed to compare risk factor profiles between SIVD with and without multiple lacunes. Methods: We divided 47 subjects (22 males, mean age. 68 years) recruited from VADAPET (Multicenter Trial For Evaluation Of The Changes In the PET Images Of Subcortical Vascular Dementia Patient) study into two groups one with more than 5 lacunes in deep gray matter (lacune group) and the other with 5 or less(non-lacune group) Clinical characteristics and laboratory findings of two groups were compared. Results: Nineteen of 47 patients (40%) belonged to the lacune group. The lacune and non-lacune groups d d not differ in the following variables: age, hypertension, diabetes mellitus, hyperlipidemia heart disease, history of stroke or TIA, history of trauma or major surgery, family history of hypertension stroke, or dementia, age at diagnosis of dementia, body mass index, white blood cell count, ESR, CRP, fibrinogen, hemoglobin A1C, total cholesterol. LDL cholesterol creatinine, proteinuria, glucosuria, and microhematuria. However, male sex, smoking alcohol. hemoglobin, and HDL cholesterol were possibly associated more with lacune group SIVD than with non-lacune group (p<0 1) Multivariate analyses revealed that smoking, hemoglobin, and HDL cholesterol were independent predictors of SIVD with multiple lacunes Conclusion: Our study suggests that SIVD with multiple lacunes may be significantly different in smoking habits hemoglobin, and HDL cholesterol from SIVD without multiple lacunes.

응답특성 개선을 위한 강인한 적응제어기의 개발

최재석,최진배,이순영 慶尙大學校 工科大學 自動化및컴퓨터應用技術硏究所 1995 自動化 및 컴퓨터應用技術 Vol.2 No.1

This paper introduces a new approach to adaptive control using a combination of direct, indirect and variable structure method. A new variable structure input is derived to counteract the effects of disturbances. Direct input is used to have fast response and indirect input improves the transient behavior of the system. Computer simulation results illustrate the very satisfactory performance of the proposed algorithm.

환자만족도 조사설문지의 설문문항 배열에 따른 신뢰도 분석

최귀선,조우현,홍재석,이선희,강명근 한국의료QA학회 2000 한국의료질향상학회지 Vol.7 No.2

Objectives : The purpose of this study was to evaluate the reliability of questionnaire according to item arrangement on patient satisfaction questionnaire. Methods : We developed the two types of questionnaire with different item arrangement. In the first type (A), questions were arranged according to medical service dimensions. Questions in the second type (B) were arranged according to medical process. Both questionnaires were composed of six dimensions: physical environments, process, competence, courtesy, information giving, understanding patients. Measurements were performed on a 5-score Likert scale. In an outpatients and inpatient survey, total 777 patients answered the type A (outpatients: 257, inpatients: 128) or Type B (outpatients: 257, inpatients: 135). In order to compare the internal consistency of two types. Cronbach's α were calculated. Multiple regression analysis was also performed to know which type of questionnaire explain more of the overall satisfaction. Results : In outpatient survey, type A questionnaire showed higher internal consistency than B except physical environments dimension. Also in inpatient survey, type A had higer internal consistency than B in four dimensions(process, competence, courtesy, understanding patients). In the results of multiple regression analysis, type A questionnaire (R² =0.53) explained more of the variation in overall satisfaction then B questionnaire (R2=0.43) in outpatient survey. In inpatient survey, type B questionnaire (R²=0.40) explained, more of the variation in overall satisfaction than type A questionnaire (R² =0.33).But the.difference of R was not significant in inpatient survey. Conclusion : The results of this study support that type A questionnaire has higer reliability in assessment of consumer satisfaction than type B.

실무개발자를 위한 BSD 소켓프로그래밍에 관한 연구

최대석,권중장,최재원 경성대학교 공학기술연구소 2002 공학기술연구지 Vol.9 No.-

네트워크 응용 프로그램을 개발하기 위해서는 Socket API를 많이 이용한다. Socket API를 이용해 정상적인 동작을 하는 것은 아주 쉽다. 그러나 실제 개발 과정에서 정상적인 상황이 아닌 여러 가지 비정상적인 오류에 처하게 됨에 따라 속수무책일 때가 많다. 따라서 본 논문에서 각 플랫폼별로 비정상적인 오류들의 사례 연구를 통하여 효율적인 응용시스템 개발에 도움을 주고자 한다.

남북상사중재위원회 운영상의 문제점과 활성화방안

최석범,박근식,김태환,김재학,박선영 한국중재학회 2007 중재연구 Vol.17 No.1

The commercial relationship between South and North Korea is defined under the concept of economic relation and cooperation. To resolve any dispute that can arise from the trade and investment relations between South and North Korea, 'Agreement on the Procedures to Resolve Commercial Arbitration of South-North Korea' came into force in August 2003. Commercial Arbitration Committee of South-North Korea will be organized as the member lists of the committee were exchanged in July 2006 between South and North Korea. This committee must become a central system to settle the trade and investment disputes between South and North Korea. North Korea's Foreign Economic Arbitration Act was enacted to provide the foreign investors with the safe measures in their investments such as dispute resolution. But this Act can not dispute the trade and investment disputes between South and North Korea. The purpose of this paper is to contribute to the activation of arbitration between South and North Korea by studying Commercial Arbitration Committee of South-North Korea introduced by Agreement on the Procedures to Resolve Commercial Arbitration of South-North Korea and Agreement on the Construction and Operation of Commercial Arbitration Committee of South-North Korea and finding the problems and solutions of Commercial Arbitration Committee of South-North Korea.

정신분열병 환자의 반응시간

최형식,정범석,김한규,송현주,이재원,김창윤 大韓神經精神醫學會 2000 신경정신의학 Vol.39 No.5

연구배경: 주의력은 인지적인 정보처리과정(information processing)의 가장 기본적인 단계이다. 반응시간 (reaction time)은 주의력을 가장 잘 반영하는 검사 중 하나로서, 자극이 제시된 후 반응이 시작되기까지 반응 여부를 결정하는데 걸리는 시간인 판단 시간(decision time)과 반응이 시작되면서 목표에 도달할 때까지 시간인 운동시간(motor time)으로 나누어 볼 수 있다. 기존의 연구결과로는, 정신분열병 환자군에서 반응시간의 수행이 떨어져 있다는 보고는 많이 되어왔으나 차이가 없다는 보고도 있으며, 판단시간과 운동시간 중 어느 부분에 장애가 있는지 명확하지 않다. 또한 반응시간 측정값은 질병의 진단적 유형(diagnostic subtype), 증상, 경과 등의 영향을 받으며 개체간의 변동(inter-individual variation)이 크고, 같은 피험자라도 측정시점이 다를 때마다 차이를 보이는 개체내 변동(intra-individual variation)이 커서 검사결과마다 차이를 보이고 있는 상태이다. 목적: 환자군은 개체간 변동이 크고 다른 임상적 요소에 의해 영향받는 점을 고려하여, 임상적으로 안정적인 경과에 있는 정신분열병 환자만을 대상으로 정상인 군과 반응시간의 차이를 비교하고자 하였다. 또한 반응시간을 판단시간과 운동시간으로 나누어 측정하여 각각을 비교분석 하고자 하였고, 개체내 변동이 큰점을 고려하여 25회 반복 측정을 실시하고 이에 따른 변동의 경향성을 조사하고자 하였다. 방법: DSM-Ⅳ에 의해 '정신분열병'으로 진단된 환자로서, 급성기 이후 항정신병약물을 유지하고 있으며BPRS(brief psychiatric rating scale) 30점 이하의 임상적으로 안정적인 상태가 3개월 이상 유지된10명이 환자군으로 포함되었고, 정상인은 자원자 10명이 포함되었다. 검사도구는 비엔나 테스트 시스템 반응유닛(Reation Unit) 파라미터 S8을 이용하였다. 총 6가지의 자극이 무작위로 1측정시기(session) 당 총 32회 주어지고, 피험자는 이중 특정 자극에 8번만 반응하도록 되어 있다. 시작 전 1회 연습 후 총 25측정시기를 5분 간격으로 반복하였다. 반응 시간을 판단시간과 운동시간의 합으로 정의하고 세 가지 모두 컴퓨터를 이용하여 자동 측정되었다. 반응·판단·운동 시간의 비교에는 반복 측정을 고려한 분산분석(repeated measures analysis of variance)을 사용하였다. 결과: 환자군은 정상인에 비하여 유의하게 반응시간의 수행속도가 저하되어 있었다(p<0.01). 판단시간과 운동시간으로 나누어 볼 때, 환자군에서 판단시간이 유의하게 느렸고(p<0.01), 운동시간은 수행저하의 경향을 보였으나 통계적으로 유의하지는 않았다. 25회 반복측정시 양군 모두 측정시기에 따른 유의한 변화를 보였고(p<0.01), 환자군의 반응시간은 개체간의 차이뿐 아니라 개체내 변동이 큰 경향을 보였다. 옳게 반응한 횟수(correct response)는 환자군에서 저하되는 경향을 보였으나 통계적으로 유의하지는 않았다. 고찰: 정신분열병 환자군에서 판단시간이 유의하게 저하된 것은, 반응시간의 저하가 운동요소 보다는 인지적 요소에 의한 것임을 시사하는 것으로, 정보처리과정의 기본적인 단계인 주의력 장애를 보여주는 것으로 생각된다. 비교적 안정적이고 임상적인 특성이 동일한 환자군에서도 반응시간이 대조군에 비해 큰 개체간 차이와 개체내 변동성의 경향을 보였으며, 이는 단순한 측정오차라기 보다는 정신분열병 환자군의 인지기능의 특성을 반영하는 것으로 생각된다. 중심단어:정신분열병·반응시간·판단시간·운동시간·개체간 변동·개체내 변동. The reaction time(RT) has been known to reflect attention that controls the flow of information processing. Extensive research has demonstrated cognitive impairment in schizophr-enia subjects using RT taske. However, little work has been done examining the relative contribution of DT(decision time) and MT(motor time) to slowed RT in schizophrenics. Also, recent investigators have observed that schizophrenic patients exhibit larger intra-individual variability in RT than do normal comparison subjects. The purpose of this study, using multi-stimulus convergent RT task, was to explore the speed of RT, relative contribution of decision time(DT) and motor time(MT) to slowed RT, overall sequential profile in 25 repeated-time measurements in 10 schizophrenic out-patients and 10 normal control subjects. Overall reaction time and decision time were slower in schizophrenic subjects than in normal controls. The motor time was not shown to be significantly different between the two groups with 0.05 significance level, although there was some trend indicating schizophrenic subjects were slower consistently in repreated measurements over time. These results suggested that the slower reaction time in schizophrenic subjects was mostly determined by cognitive component, decision time rather than motor time. Sequential profile of repeated measurements showed greater intraindividual and interindividual variations in schizphrenics than in normal controls. These results indicate that high variabilities are not merely measurement errors but characteristic of schizophrenic psychopathology. KEY WORDS: Schizophrenia·Reaction time·Decision time·Motor time·Inter-individual variation·Intra-individual variation.

적응제어계의 응답특성 및 강인성 향상에 관한 연구

최재석,최진배,이순영 慶尙大學校 工科大學 自動化및컴퓨터應用技術硏究所 1994 自動化 및 컴퓨터應用技術 Vol.1 No.1

This paper proposes a new adaptive algorithm to improve the robustness and performance of the adaptive control systems. This adaptive algorithm counteracts the effects of disturbances and makes the time derivative of Lyapunov function non-positive, V≤0. As a result, the output error approaches zero as t → ∞ not only in the presence of bounded disturbances, but ideal case. Computer simulation results are presented to show the effectiveness of the proposed algorithm.

공동주택의 장수명화 및 재생을 위한 IHCS 표준모델 개발 : 개념 및 특성을 중심으로 With a focus of Concept and Character

최경석,강재식,양관섭,이승언 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1

Recently Excessive national resources, energy losses and social·economical problems are induced by reconstruction apartment housing which was constructed about 20 years and is enough to keep one's residence structurally. Especially, the greatest obstruction in longevity & recycling technology of apartment housing is the current Ondol system of wet process integrated structures. Also the current Ondol system is difficult to improve due to its character of material and process. The object of this study is to develop IHCS(Infill Heating & Cooling System) standard model with prefabricated & dry process that shall be the substitution for the current wet Ondol system.

재삽입을 수행하는 고차원 색인 구조를 위한 효율적인 동시성 제어 알고리즘

최길성,이석희,송석일,유재수,조기형 충북대학교 컴퓨터 정보통신 연구소 1999 컴퓨터정보통신연구 Vol.7 No.1

본 논문에서는 기존의 동시성 제어 기법들을 분석하고 CIR-트리를 위한 효율적인 동시성 제어 알고리즘을 제안한다. 기존에 다차원 색인구조에 대한 동시성 제어 기법으로 제시된 ??-트리는 다른 기법들에 비해 동시성 효율이 우수한 것으로 알려져 있다. 하지만 ??-트리를 CIR-트리에 그대로 적용할 경우 두 가지 문제점이 발생된다. 첫째는, CIR-트리의 성능 향상에 중요한 요소가 되는 재삽입에 대한 동시성 제어를 ??-트리에서 고려하지 않고 있다. 둘째는, ??-트리는 동시성 수준의 한계가 있는 잠금 결합 기법을 사용하고 있다. 본 논문은 두 가지 문제점을 해결할 수 있는 새로운 동시성 제어 알고리즘을 제안하며, 제안된 동시성 제어 알고리즘의 정확성을 증명한다. 또한, 제안한 알고리즘이 기존의 알고리즘에 비해 성능이 우수함을 실험을 통해서 보인다. In this paper we analyze existing concurrency control methods and propose an efficient concurrency control algorithm for CIR-tree. Among the existing concurrency control methods for multidimensional index structures, ??-Tree is one of the most efficient concurrency control algorithm. However, when we apply ??-Tree to the CIR-tree, there are two problems. First ??-Tree does not consider concurrency control for reinsertion operations that are main factor of performance improvement in the CIR-tree. Second since the ??-Tree uses lock-coupling strategy, it limits concurrency of the CIR-tree. The proposed concurrency control algorithm overcomes the two problems. We show the correctness of our proposed currency control algorithm. It is also shown through experiments that our algorithm outperforms the existing algorithms.