• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 A
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• pp.177-179
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• 2000

In this paper, we developed the online Monitoring & Diagnostic(MD) system of distribution transformers. It consists of the Data Acquisition(DA) module and the DataBase(DB) module. The acquired data from the distribution transformers is stored to the DB in an on-line. The DB is planned and made to the RDBMS (Relative DataBase Management System) to manage the data efficiently. The developed MD system estimates the loss of life from the DB. Thus, it could be managed the career and the functional lifetime of the transformer more efficiently than existing systems. In the case study, the oil temperature rising experiment is performed by using the back loading method in the laboratory level. From the results, the proposed MB system can be a practical applications for the distribution transformers.

• Journal of Information Technology Applications and Management
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• 제23권4호
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• pp.55-70
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• 2016

Recently, development of indoor positioning system and IoT such as beacon makes it possible to collect and analyze each customer's shopping behavior in off-line shopping malls. In this study, we propose a realtime brand recommendation scheme based on each customer's brand visiting history for off-line shopping mall with indoor positioning system. The proposed scheme, which apply collaborative filtering to off-line shopping mall, is composed of training and apply process. The training process is designed to make the base brand network (BBN) using historical transaction data. Then, the scheme yields recommended brands for shopping customers based on their behaviors and BBN in the apply process. In order to verify the performance of the proposed scheme, simulation was conducted using purchase history data from a department store in Korea. Then, the results was compared to the previous scheme. Experimental results showd that the proposed scheme performs brand recommendation effectively in off-line shopping mall.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.397-398
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• 2007

In this paper, we have verified the applicability of the line-clustering segmentation method to steel-tube X-ray images. Image data is partitioned into three regions on the base of vertical line edge detection. Parameters for necessary condition, such as neighborlity, similarity and directional neighbor correlation coefficients, proposed in that method is calculated and applied to such selected regions separately Segmental features at each region is extracted statistically and functional classification is clustered by the point or space process. The analyzed data and experimental results show that the line-clustering segmentation method has a high applicability to X-ray image.

• International Journal of Aeronautical and Space Sciences
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• 제10권2호
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• pp.34-42
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• 2009

Gas turbine performance diagnostics is a method for detecting, isolating and quantifying faults in gas turbine gas path components. On-line precise fault diagnosis can promote greatly reliability and availability of gas turbine in real time operation. This work proposes a GUI-type on-line diagnostic program using SIMULINK and Fuzzy-Neuro algorithms for a helicopter turboshaft engine. During development of the diagnostic program, a look-up table type base performance module are used for reducing computer calculating time and a signal generation module for simulating real time performance data. This program is composed of the on-line condition monitoring program to monitor on-line measuring performance condition, the fuzzy inference system to isolate the faults from measuring data and the neural network to quantify the isolated faults. Evaluation of the proposed on-line diagnostic program is performed through application to the helicopter engine health monitoring.

• 디지털콘텐츠학회 논문지
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• 제4권1호
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• pp.57-66
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• 2003

본 논문에서는 인터넷 기반에서의 3자(환자, 의사, 약사)간의 상호대화형 원격진료 시스템 구현으로서, 효율적인 진료와 빠른 처리를 위한 전자진료차트 및 자료처리에 관한 내용을 제시하고 있다. 즉, 고가형 시스템, 비호환성 등 기존 원격진료시스템의 문제점을 해결한 저가형이면서, 누구나 참여할 수 있는 웹상에서의 시공간을 초월한 on-line 및 off-line 겸용모드의 지능형 원격진료시스템이다. 데이터베이스는 IIS 4.0 웹서버상에서 ASP와 SQL을 연동한 구현하여 효율적인 자료처리를 위한 시스템 통합과 환자와 의사간의 on-line 상담, 그리고 off-line상에서의 진료와 환자가 지정한 약사로의 처방전 전송 및 조제, 그리고 진료데이터의 저장 및 검색으로 인한 반영구적인 진료데이터저장, 환자 및 의사의 본 진료데이터를 이용한 보다 정확한 진료 및 처방등이 가능하다.

• 한국측량학회지
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• 제10권2호
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• pp.63-71
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• 1992

디지탈 지도 데이타베이스는 다중 축적의 개념을 포함하여 여러 가지 목적을 두고 제작되며 단일 축적으로만 사용하기 위해 Base Map을 구축하는 사례는 극히 보기 드믄 현상이라고 할 수 있다. 따라서 지도의 일반화와 다중표현에 대한 Line의 단순화 처리에 있어서 가장 중요한 문제는 일반화된 그래픽 데이타의 정확도와 인식도를 모두 부여하기 위해 Base Map 상의 정보를 단순화하기 위해 설정하는 허용범위를 디지틸 화일내에서 Feature의 형태에 따라 수정이 가능하도록 하는 것이다. 본 연구에서는 하나의 디지털 화일내에서 다양한 축척상으로 수행되는 Line의 단순화에 대한 여러가지 알고리즘을 고찰하였으며, 지도의 표현상에 변화를 줄 수 있는 선형성 Feature 별로 축척에 따른 규칙을 설정하였다. 수치화된 line 데이타 사이의 상관성을 분석하기 위하여 2가지 변형량을 측정하여 5가지 알고리즘에 대한 평가를 시도하였다. 데이타의 분석결과 Douglas-Peucker 알고리즘이 단순화 후의 변형량에 있어 가장 작은 영향을 받음을 알 수 있었다. 이러한 연구 결과로부터 디지탈 화일을 소축척으로 표현하기 위해 단순화를 실시할 경우 내부적으로 지니고 있어야 하는 기하학적인 항목으로서 그 크기와 변동량에 대한 수치적인 안을 제시함에 따라 지도의 단순화에 대한 가능성을 입증하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.577-580
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• 2003

Stress state of chip formation zone is one of the main problems in metal cutting mechanics. In two-dimensional case this process is usually considered as consistent shears of work material along single of several shear surfaces. separating chip from workpiece. These shear planes are assumed to be trajectories of maximum shear stress forming corresponding slip-line field. This paper suggests new approach to the constriction of slip-line field, which Implies uniform compression in chip formation zone. On the base of given model it has been found that imaginary shear line in orthogonal cutting is close to the trajectory of maximum normal stress and the problem about its determination have been considered. It has been shown that there is a second central slip-line field inside chip, which corresponds well to experimental data about stress distribution on tool rake face and tool-chip contact length. The suggested model could be useful in solution of various problems of machining.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1419-1424
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• 2004

Railway safety is based on a risk analysis and safety assessment for the whole railway system as human, train, electric, signaling, operation, maintenance and etc. Therefore in this study, after investigating the accidents happened in electric railway on Choongang line for 5 years, from '97 to '01, a Data-Base was made through a cause and result analysis. In consideration of economic loss and human resources damage, a risk assessment for electric railway was also performed.

• Journal of Electrical Engineering and information Science
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• 제2권6호
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• pp.116-122
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• 1997

The audible noise produced by corona discharge in high voltage transmission lines is the most important line design consideration. In this paper, more accurate and useful formulas for predicting the A-weighted audible noise during heavy and light rain in alternative current (AC) transmission lines are proposed through comparison with the existing formulas. The proposed formulas are developed by the applications of evolutionary computations (ECs) to audible noise data base from long-term measurement.

• 한국전산유체공학회지
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• 제1권1호
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• pp.134-141
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• 1996

Wall interference is one of the major obstacles to increase the model size and data accuracy. There have been many treatments for wall interference including interference correction and adaptive wall test section. Recently, two-flexible-walled adaptive wall test section is concluded adequate for three-dimensional test. But proper location of target line and pressure holes are critical to its success. In this study, a new adaptive algorithm which dispenses target line and dependency of pressure hole distribution is suggested. The wind tunnel and free air tests are simulated by the numerical computation of Euler equations. The optimum wall shape is achieved by two variable optimization which is composed of two base streamlines. The wall interference is reduced well in the optimized result which is not sensitive to the base streamlines.