• Journal of Biosystems Engineering
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• 제22권2호
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• pp.217-226
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• 1997

This study was to develop a machine vision system to detect and to discriminate 5 kinds of apple surface defectbruise, decay. fleck, worm hole and scar. To detect the defects from an image of apple, thresholding technique was applied to images on various frames (R, G, B, H, S and I) of the color machine vision and an image of near infrared (NIR). To discriminate the detected region of defect, various features of the 5 kind defect regions were extracted from the 4 kinds of images selected above. The features were size of area, roundness, axes length ratio, mean and valiance of pixel values, standard deviation of real part of amplitude spectrum in frequency domain obtained by Fourier transform of pixel data and mean and standard deviation of power spectrum obtained by the same transform of pixel data. Routines to discriminate the defects from the features of image were developed and tested to prove their validity. The test resulted that I-frame and NIR images were the most desirable. Accuracies of the two images to discriminate the defects were noted as 76% and 77%, respectively.

• 한국공작기계학회논문집
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• 제14권6호
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• pp.110-116
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• 2005

A single-piece-machined-part has superior characteristics to an assembly of several pieces of part especially for aircraft components. It is necessary to develop high efficient 'multi-head router machine' for machining a large size single-piece-part on a large scale. In this type machine, many cutting chips are generated. These chips should be removed automatically f3r productivity and part precision. In this study, the design evaluation of the cutting chip collecting apparatus for 'multi-head router machine' was complemented using performance test and finite element analysis.

• 한국수학사학회지
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• 제17권4호
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• pp.27-36
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• 2004

이 논문에서는 튜링의 기계주의에 대한 괴델의 비평을 다룬다. 여기에서 튜링의 기계주의란 튜링기계의 기호배열이 인간의 마음의 각 상태에 대응된다는 것을 의미한다. 첫째 부분에서는 계산으로서의 인지과정에 대한 튜링의 분석을 검토한다. 두 번째 부분에서는 튜링기계의 개념을 살펴보고, 세 번째 부분에서는 인지적 체계로서의 튜링기계가 갖는 계산적 한계를 설명한다. 네 번째 부분에서는 괴델이 튜링의 기계주의에 동의하지 않았음을 보이고, 마지막으로 오라클 튜링기계과 그 함의에 대하여 논의한다.

• 한국재난정보학회 논문집
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• 제13권4호
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• pp.422-441
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• 2017

사물 인터넷을 기반으로 지하철역사의 재난 전조를 조기에 발견하고 승객들에게 피난을 유도하는 지하철 재난전조 감지 시스템 개발에 있어서 재난 발생시 상황대피 유도방법과 정확한 재난 위치 알림 및 대피경로 안내는 재난 상황에 빠른 대피와 인명피해를 최소화 할수 있는 매우 적극적인 대안이 될 수 있다. 좁은 출구밖에 없는 지하공간 구조상 소방 시설 및 장비들의 완벽한 작동을 담보하기란 쉽지 않다. 따라서 본 연구에서는 대피를 가장 효율적으로 유도할 수 있는 재난대응 EL Display 통합 보드를 개발하였으며 이를 현장 실험을 통해 실제 활용성에 대한 검토를 실험하였다. 특히, EL패널을 재난 대피유도용으로 활용한 사례가 없어 현장적용테스트를 거쳐 그 활용 가능성을 검증하였다.

• 설비공학논문집
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• 제7권4호
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• pp.654-666
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• 1995

R502 has been extensively used as a working fluid in transport refrigerating vehicles and low temperature refrigerating machines but is to be phased out by the end of 1995 due to ozone layer depletion problem. In this study, both theoretical cycle analysis and experiments were carried out to examine the best substitutes for R502. Theoretical results indicate that the alternatives available in the market today may replace R502 without significant changes in the system without suction line heat exchanger(SLHX). When the system contains a SLHX, however, COPs of the alternatives increase up to approximately 15~20% than those without the SLHX. But simultaneously, the discharge temperatures of the compressor also increrease significantly with the SLHX. Actual test results obtained from the experiment with a transport vehicle's refrigerator indicate the similar trend as those of the theoretical results. Especially, HFCs and their mixtures show lower discharge temperature than those of R502, which is one of the desirable features. Further research is needed to study the effect of the SLHX on the performance of the real machine as well as on the oil return for reliability of the system.

• 한국생산제조학회지
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• 제22권2호
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• pp.318-323
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• 2013

For fast and accurate motion of 6-axis articulated robot, more noble motion control strategy is needed. In general, the movement strategy of industrial robots can be divided into two kinds, PTP (Point to Point) and CP (Continuous Path). Recently, industrial robots which should be co-worked with machine tools are increasingly needed for performing various jobs, as well as simple handling or welding. Therefore, in order to cope with high-speed handling of the cooperation of industrial robots with machine tools or other devices, CP should be implemented so as to reduce vibration and noise, as well as decreasing operation time. This paper will realize CP motion (especially joint-linear) blending in 3-dimensional space for a 6-axis articulated (lab-manufactured) robot (called as "RS2") by using LabVIEW$^{(R)}$ (6) programming, based on a parametric interpolation. Another small contribution of this paper is the proposal of motion blending simulation technique based on Recurdyn$^{(R)}$ V7 and Solidworks$^{(R)}$, in order to figure out whether the joint-linear blending motion can generate the stable motion of robot in the sense of velocity magnitude at the end-effector of robot or not. In order to evaluate the performance of joint-linear motion blending, simple PTP (i.e., linear-linear) is also physically implemented on RS2. The implementation results of joint-linear motion blending and PTP are compared in terms of vibration magnitude and travel time by using the vibration testing equipment of Medallion of Zonic$^{(R)}$. It can be confirmed verified that the vibration peak of joint-linear motion blending has been reduced to 1/10, compared to that of PTP.

• Journal of Preventive Medicine and Public Health
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• 제10권1호
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• pp.94-101
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• 1977

Noise pollution, both in the environment and in the workplace, has been recognized as a major health hazard -one that can impair not only a person's hearing but also his physical and mental well-being. As industrialization progresses, the prevalence rate of occupational diseases is increasing, especially hearing loss, which has the highest prevalence rate among the occupational diseases. The major cause of noise is the construction of various large industries without any regulation of noise sources. Therefor, we must establish an enactment to control mechanical noise sources. as soon as possible. For the purpose of controlling the noise source, we must have exact data about such things as the sound level, the frequency of the peak sound and the revolutions per minute (r.p.m.) of the machine (a measure of the power of its motor). This study was undertaken in order to define the noise characteristics, the power of the machine's motor, the change of the sound level and the peak sound as the r.p.m. increases, and the permissible exposure time. The sample size of this study was 74 machines at 11 plants in 6 industries. The results are as follows; 1. The breakdown of the types of mechanical noise noted was : 63.6% continuous normal sound, 26.9% intermittent sound, 4.7% continuous repeating sound and 4.6% impulsive sound. 2. With respect to the type of industry, the overall sound level was the highest in the mechanical industry, with $103.8{\pm}2.8dB(A)$, and lowest in the textile industry, with $89.2{\pm}1.43dB(A)$. 3. With respect to the type of machine, the highest sound level was 124 dB(A) caused by Gauzing(II), in the mechanical industry, and the lowest was 76 dB(A) caused by Attachment (Jup Chack) (I) in the timber industry. 4. The shortest permissible exposure time to Gauzing(II) in the mechanical industry was less than 15 minutes. 5. Among 74 machines, 68.2% of the peak sound was situated in the high frequency range (52.7% at 2 KHz, 4.1% at 4 KHz and 1.4% at 8 KHz). 41.8% of the peak sound was in the middle frequency range (4.1% at 250Hz, 14.8% at 500Hz and 22.9% at 1KHz). 6. If one machine had two motors or more, the peak sound was shifted to the low frequency range. 7. As the r.p.m. increased, the overall and peak sound levels were increased without any change of the frequency of the peak sound. 8. Whenever the machines had the same kind and the same r.p.m., the overall and peak sounds were changed by the physicochemical characteristics of the raw materials and the management.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1626-1628
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• 2003

The lightning arrester is a very important overvoltage protection device in the electric power system. Therefore, the inspection of lightning arrester whether it keeps its performance or not properly has close related to verifying the safety confidence of the electric power system. But the development of the deterioration measuring method and on-line detecting system, is necessary to monitor the deterioration of the lightening arrestor. In this paper, we developed the lightning arrester degradation monitoring system. This system detected leakage current of lightning arrester by using the ZCT, and analyze the third harmonics ingredient of leakage current using DFT method in the Data Acquisition Unit(DAU). The analyzed current signal is transmit to the Human-Machine Interface(HMI), and HMI alarmed when accident are occurred and informed with the amplitude of leakage current to the operator.

• 한국산업정보학회논문지
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• 제11권2호
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• pp.18-28
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• 2006

최근에 새로운 교수 학습 방법의 하나로 대두되고 있는 e-NIE는 학습자 중심의 흥미와 적성, 창의성 개발, 비판적 사고력의 함양을 통한 문제해결능력과 의사결정 능력을 키워 준다. 본 논문에서는 공업계 고등학교 전기과의 '전기 전자 측정' 과목 중에서 'I. 측정 일반' 단원을 중심으로 보충 심화 학습지를 개발하였으며, 이를 활용한 e-NIE 수업 모형을 설계하고 구현하였다. 본 논문에서 제안한 e-NIE 수업 모형의 효과를 검증하기 위하여 통제 집단에게는 전통적 수업을 실시하고 실험 집단에게는 e-NIE 수업을 실시한 후 결과를 분석하였다. 그 결과 e-NIE 수업을 실시한 학습자들이 학습 동기, 학습 태도, 자기 주도적 탐구력 분야에서 긍정적인 효과가 있는 것으로 확인되었다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(1)
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• pp.219-226
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• 1997

This paper presents the development of an Integrated Test Facility (ITF) that consists of a full-scope Human Machine Simulator (HMS) and some experimental measurement systems. This facility is aimed to experiment with tile design of the control room environment and the human interaction as it relates to the control of advanced nuclear power plants.