• 한국자기공명학회논문지
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• 제18권1호
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• pp.1-4
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• 2014

It is generally understood that protein-protein interactions proceed via transient encounter complexes that rapidly evolve into the functional stereospecific complex. Direct detection and characterization of the encounter complexes, however, been difficult due to their low population and short lifetimes. Recent application of NMR paramagnetic relaxation enhancement first visualized the structures of the encounter complex ensemble, and allowed the characterization of their physicochemical properties. Further, rational protein mutations that perturbed the encounter complex formation provided a clue to the target search pathway during protein-protein association. Understanding the structure and dynamics of encounter complexes will provide useful information on the mechanism of protein association.

• 대한수학회지
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• 제31권3호
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• pp.457-466
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• 1994

When we study complex analysis, we often encounter multi-valued functions. Provably the best known example would be $\sqrt{z}$, which has a singularity at the oritgin. In general, let $\Omega_1 and \Omega_2$ be domains in C, and let $\Gamma$ be a subvariety of $\Omega_1 \times \Omega_2$.

• Journal of Biosystems Engineering
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• 제16권3호
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• pp.327-335
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• 1991

In Korea, farming population is rapidly decreased in each decade. Consequently, farming is becoming more complex with multi cropping, animal production and green house farming. In order to encounter this complexity of farming, expert system applications on diagnosis, planning, designing, management, control, and training are demanded to meet the needs of agricultural society. In this article, expert system establishment procedures are stated step by step and extensive literature review was conducted on the expert system development techniques.

• 한국환경생태학회지
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• 제23권4호
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• pp.309-316
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• 2009

휴양지역의 평가기준 설정을 위한 다양한 시각매체의 활용가능성에 대한 관심이 높다. 그러나 기준평가를 위한 시각 매체의 유용성은 시각매체가 얼마나 정확하게 현장 상태를 반영하는가에 달려있다. 본 연구는 정적 이미지와 동적 이미지를 이용하여 산정된 조우기준을 비교함으로써 움직임의 효과를 평가하였다. 연구대상지는 무등산도립공원 내 중머리 지역이었다. 총 50명의 대학생이 실험실 조사에 참여하였으며 Photoshop과 Flash 컴퓨터 프로그램을 이용하여 제작된 정적이미지와 동적 이미지의 허용도를 평가하였다. 조사결과, 정적 이미지와 동적 이미지 간에 최대허용수에 차이가 없는 것으로 분석되었으며 전반적 조우규범측정곡선도 거의 동일한 것으로 나타났다. 이미지 노출 순서와 움직이는 사람의 비율에 따른 조우기준도 조사되었다. 그러나 본 지역과 같은 특정 상황에서 조우기준을 개발하기 위하여 정적 이미지 대신 보다 복잡한 방법을 요구하는 동적 이미지를 이용함으로써 얻는 이점은 없다고 판단된다. 보다 정교한 매체이용에 따른 장단점에 대하여 토의하였으며 다른 자원환경 평가에 움직임 또는 소리와 같은 요소들이 조우규범에 미치는 영향에 대한 보다 많은 연구가 요구된다.

• Interdisciplinary Bio Central
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• 제2권2호
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• pp.2.1-2.4
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• 2010

Complex diseases, such as stroke and cancer, have two or more genetic influences and are affected by environmental factors, which complicate them. Due to the complex characteristics of these diseases, we must search and study comprehensive literature-based article resources. Some disease-related literature databases have been developed through specialized journal issues or major websites. Most of them, however, are scattered throughout a website, and users encounter difficulties in finding accurate and comprehensive information easily and quickly. We developed StrokeMed, an integrated literature database for stroke and the differentiation of stroke syndrome. The system allows users to explore PubMed search results, categorized by MeSH (Medical Subject Headings), and the differentiation of stroke syndrome in Oriental medicine. StrokeMed collects data from important sites, such as PubMed, Scirus, and Scopus, automatically to maintain higher-quality and updated content. Currently, the system indexes more than 20,000 PubMed abstracts that are related to stroke, stroke etiology, and Oriental medicine. The system provides valuable literature information to the scientific and medical fields in stroke.

• 천문학회보
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• 제42권2호
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• pp.48.3-49
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• 2017

Interplanetary space of the solar system contains a large number of dust particles, referred to as Interplanetary Dust Particles (IDPs) cloud complex. They are observable through meteors and zodiacal lights. The relative contribution of possible sources to the IDPs cloud complex was an controversial topic, however, recent research (Yang & Ishiguro, 2015 and references therein) suggested a dominance of cometary origin. In this study, we numerically investigated the orbital evolution of cometary dust particles, with special concerns on different evolutionary tracks and its consequences according to initial orbits, size and particle shape. The effect of dust particle density and initial size-frequency distribution (SFD) were not decisive in total cloud complex mass and mass supply rate, when these physical quantities are confined by observed zodiacal light brightness and dust particle SFD at 1 au. We noticed that, if we assume the existence of fluffy aggregates discovered in the Earth's stratosphere and the coma of 67P/Churyumov-Gerasimenko, the required mass supply rate decreases significantly. We also found out that close encounters with planets (mostly Jupiter) are the dominating factor of the orbital evolution of dust particles, as the result, the lifetime of cometary dust particles are shorter than Poynting-Robertson lifetime (around 250 thousand years). As another consequence of severe close encounters, only a small fraction of cometary dust particles can be transferred into the orbit < 1 au. This effect is significant for large size particles of ${\beta}$ < 0.01. The exceptional cases are dust particles ejected from 2P/Encke and active asteroids. Because they rarely encounter with Jupiter, most dust particles ejected from those objects are governed by Poynting-Robertson effect and well transferred into the orbits of small semimajor axis. In consideration of the above effects, we directly estimated probability of mutual collisions between dust particles and concluded that mutual collisions in the IDPs cloud complex is mostly ignorable, except for the case of large sized particles from active asteroids.

• Composites Research
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• 제20권5호
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• pp.56-63
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• 2007

복소퍼텐셜을 이용하여 타원공 또는 균열을 내재한 복합재 적층판구조 해석법을 고찰하였다. 복합재 적층판은 충격에 취약하며 이러한 충격손상은 타원공이나 균열형태의 노치로 모델화된 바 있다. 이와 같이 컷아웃부를 내재한 복잡한 형태의 복합재 적층판 해석에 유한요소해석법이 널리 사용되고 있으나 피로하중 하에서의 손상허용성 평가와 같이 손상진전에 따라 반복적으로 유한요소모델링을 수정하여 해석을 수행하여야 하는 경우 매우 번거로운 작업이 요구된다. 이러한 관점에서 복소퍼텐셜을 이용한 해석적 기법은 매우 간편하고 사용하기 손쉬운 기법이라고 할 수 있다. 이러한 해석법에 의한 계산결과를 유한요소해석 결과와 비교 분석함으로써 계산과정의 유효성과 용이성을 검증하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.10-13
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• 2007

System requirements (SRs), which describe the technical attributes to be satisfied by a desired system, serve as a fundamental guideline for system development. Standard methods and processes to define SRs are suggested in systems engineering literature. But in practice, we encounter many difficulties in defining and managing SRs since there are few experiences on development of complex systems in accordance with systems engineering processes of development. In this paper, to expanding SRs management experiences in a working-level, we reviewed problems occured in SRs defining process in 'Urban MAGLEV Train Project', and analyzed our activities to adjust and solve the problems.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국제학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.909-914
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• 1988

The structure of a digital controller based on modern control theory is more complex than that of a PID controller. In implementing the digital control of an actual system by using the digital controller, we often encounter gaps between theory and practice e.g. quantization error, sampling error, modeling error, contaminated noise etc. In such cases, simulator plays an important role in detecting difficulties. This paper demonstrates the importance of the computer simulator for designing a digital controller. The controller and the simulator are constructed by different computer respectively, with a link between the blocks by analogue signals through the A/D, D/A converters. Through the simulator test, we can evaluate the digital controller; identify and solve difficulties in the digital control. The controller, which pasted the simulator test, is used identically in the actual system. This was a successful procedure for designing the controller. As an example, we successfully constructed the digital controller using the computer simulator for inverted pendulum control. We then compared the control results of simulator and actual equipment. Furthermore we commented on the construction of the computer simulator which exactly expressed the actual system.

• Advances in Computational Design
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• 제2권3호
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• pp.195-210
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• 2017

Simultaneous optimization of trusses which concurrently takes into account design variables related to the size, shape and topology of the structure is recognized as highly complex optimization problems. In this class of optimization problems, it is possible to encounter several unstable mechanisms throughout the solution process. However, to obtain a feasible solution, these unstable mechanisms somehow should be rejected from the set of candidate solutions. This study proposes triangular unit based method (TUBM) instead of ground structure method, which is conventionally used in the topology optimization, to decrease the complexity of search space of simultaneous optimization of the planar truss structures. TUBM considers stability of the triangular units for 2 dimensional truss systems. In addition, integrated particle swarm optimizer (iPSO) strengthened with robust technique so called improved fly-back mechanism is employed as the optimizer tool to obtain the solution for these class of problems. The results obtained in this study show the applicability and efficiency of the TUBM combined with iPSO for the simultaneous optimization of planar truss structures.