• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.2
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• pp.107-113
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• 2001

This work presents field-dependent Bingham and response characteristics of MR fluids under shear and flow modes. Two different types of magneto-viscometers are designed and manufactured for the shear and flow modes. respectively. For the MR fluid to be tested, MRF-132LD of Lord co. is employed. The field-dependent yield stress is experimentally distilled at various temperatures using the magneto-viscometers. Time responses of the MR fluids to step electric fields are also evaluated under two operating modes.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.75.4-76
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• 2015

우리는 동아시아 각국(대한민국, 중국, 일본)의 VLBI관측망을 통합하고 구성될 동아시아 VLBI 관측망(East Asia VLBI Network; EAVN)의 초기 검증 작업을 진행하고 있다. EAVN은 2 ~ 129 GHz로 관측이 가능하는데, 주로 6.7, 8, 22, 43 GHz로의 관측을 상정하고 있다. 또한 최대 기선장은 약 5,000 km으로 공간분해능은 약 0.3 mas(43 GHz로의 관측의 경우)가 된다. 높은 공간분해능과 고감도의 특징을 활용하고 저광도 활동성은하핵이나 우리 은하의 메이저 천체 등의 연구에 대해서 위력을 나타낼 수가 있다. 우리는 EAVN 시험관측, 상관처리, 자료처리의 실행, 및 그것들을 통한 EAVN 운영의 검증을 하는 EAVN Tiger Team을 2013년에 조직하고 현재까지에 8 GHz 및 22 GHz로 8회의 VLBI 시험관측을 실행하였다. 상관처리는 주로 한국천문연구원에서 운영하고 있는 한일 공동상관기(KJJVC)와 상하이천문대의 소프트웨어 상관기(DiFX)로 실행되어 있다. 현재까지에 8 GHz 및 22 GHz 쌍방에서 프린지검출에 성공하고 있고, 올해는 영상합성을 포함한 과학적인 관측을 진행할 예정이다. 이 발표에서는 EAVN의 개요와 과학목표, 시험관측 현황과 결과, 및 앞으로의 운영 계획 등을 소개하겠다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.2
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• pp.199-210
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• 2012

This paper is designed to put forth a proposal for configuration of an optimized observation network based on GNSS CORS with a view to continued monitoring of crustal deformation in the East-Asian region. For this purpose, a comprehensive analysis of the results of the testing of various forms of GNSS CORS observation network tentatively constructed based on the Asia-Pacific IGS station has confirmed that geometrically arranged minimum five and ten or more reference points and an EAREF, constructed with a baseline length no longer than 2,500km, can produce an optimum outcome. And an EAREF-applied analysis on the effects of the Great Eastern Japan Earthquake of March 2011 shows that there were conspicuous positional movements in Japan and Korea while there was no significant movement in other regions.

• The Journal of the Korea Contents Association
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• v.7 no.3
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• pp.176-186
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• 2007

As SAR data have the strong point that is not influenced by weather or light amount in comparison with optical sensor data, they are highly useful for temporary analysis and can be collected in time of unforeseen circumstances like disaster. This study is to extract DEM from L-band data of JERS-1 SAR imagery using InSAR and DInSAR processing techniques. As a result of analyzing the extracted coherence and interferogram images, it was shown that the DInSAR 3-pass method produces more suitable coherence values than the InSAR method. The accuracies of DEM extracted from the SAR data were evaluated by employing the DEM derived from the digital topographic maps of 1:5000 scale as reference data. And it was ascertained that baselines between antenna locations largely affect the accuracy of extracted DEM.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.12a
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• pp.19-22
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• 2001

In this paper, Streaming Current Monitor (SCM), Pilot Filter (PF) and Coagulant Feeding System(CFS) for fuzzy neural network are used as a coagulation control method in WTP and the results are compared. Several parameters such as coagulant dosage, pH, and turbidity have been changed to find the response characteristic of each equipment. SCM, PF and CFS responded for certain parameters but the range of sensitivity was different each other. It is demonstrated that WTP will be operated more efficiently when SCM, PF and CFS are used as coagulation control strategy.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.185_186
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• 2009

전력산업분야는 스마트그리드 표준체계 및 고도화된 정보 통신 인프라의 도입과 분산전력 등에 대한 신기술 도입에 의해서 급격한 변화기를 맞이하고 있다. 현재 미국과 EU에서는 세계시장을 겨냥해서 스마트그리드의 국제표준화를 주도하고 있으며, 제3세계에서는 전력 설비 시장의 지속적 성장이 예상되고 있다. 이에 국내에서도 국제 경쟁력 확보 및 신성장동력 창출을 목표로 K-Grid 구성을 위한 연구가 진행 중이다. K-Grid 시험평가를 위해서는 전력체계의 운영망과 별개의 시험망 구성이 필요하며, 그 시험망을 통한 검증을 위해 시험망내 표준 규격의 통신환경의 설계 및 기능검증은 매우 중요한 요소이다. 본 논문에서는 K-Grid 시험평가망 구성이후 평가를 위해 사용할 수 있는 주요 Component의 설계과정 중의 일부인 MMS 기반의 Node간 통신 환경구성 및 기능검증을 위한 연구결과에 대해 설명한다.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.3
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• pp.62-74
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• 1994

This paper addresses on the model synthesis and performance analysis of an engine mount featuring electro-rheological(ER) fluids which undergo a phase change when subjected to electric fields. A novel type of ER fluid-filled engine mount is devised and its hydraulic model is constructed. An equivalent mechanical model is subsequently obtained from the governing equation of the hydraulic model. The model parameters associated with the ER fluids are distilled from experimental investigations on the Bingham properties of the fluids. The distilled data are then incorporated into the governing model to undertake feasible work through computer simulations,. It is shown that the proposed engine mount has an inherent capability of controlling both the damping force and the resonance frequency. Other superior performance characteristics accrued from the proposed methodology are also evaluated.

• Annual Conference on Human and Language Technology
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• 1994.11a
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• pp.395-399
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• 1994

정보 검색의 효율은 정보검색 시스템에서 사용되는 지식의 질에 상당한 영향을 받는다. 이러한 지식 표현의 한 가지로 널리 사용되고 있는 것이 시소러스이다. 이러한 시소러스의 구축은 지식을 얼마만큼 잘 구성하는가에 있다. 따라서 시소러스의 자동 구축은 상당한 효용을 지니게 된다. 시소러스의 자동구축시에 대량의 말뭉치로부터 지식을 추출하는 방법론이 많이 연구되어 오고 있다. 그러나 이러한 방법은 단어의 통계적인 행태에 크게 의존하고 있기때문에 자료 회귀(data sparseness)의 문제가 큰 장에 요인이 되고 있다. 본 연구에서는 이러한 자료회귀문제를 해결하기 위해 추론망을 사용하고자 하는 모험을 제시하고자 한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.105-108
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• 2004

This paper introduces a process of the development of a vibration test dummy for the posture of inclined seating. Experimental devices was invented to measure apparent mass curves on the contact point of the hip and the back of a seated human body. During the excitation of a rigid seat secured to a hydraulic exciter, force and acceleration signals were measured on the contact points to determine the apparent mass. In order to describe nonlinear characteristics of a human body, seven levels of Gaussian random signal were used for the base excitation. The modeling of the human body will be performed using measured apparent mass curves. The modeling will be done by June and the prototype of the test dummy will be invented in the following six months.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.4 no.3_4
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• pp.103-104
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• 1971

A cod, Gadus macrocephalus TILESIUS was studied on the length-weight relationship. The fish were sampled from those caught by set nets for cod in the Yellow Sea during the period from April 1964 to May 1964. The data for this study were taken from 247 fish. The relationship between the body length (X) in mm and body weight(Y) in g is indicated as follow : 160mm to 339mm : $Y=0.000001225X^{3.42706}$