• 제목/요약/키워드: electric machine

검색결과 861건 처리시간 0.026초

한국의 FTA 체결국과의 기술무역 연구 (A Study on Technology Trade of the Korea and the Target for Concluding an FTA)

  • 백은영
    • 통상정보연구
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    • 제13권4호
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    • pp.125-149
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    • 2011
  • 최근 가속화되고 있는 한국의 FTA 체결 및 발효 시점에서 기술격차가 있는 국가간의 FTA는 산업집적효과 등에 의한 동태적인 산업구조 재편 차원에서 기술열위국에 부정적인 효과가 있을 수 있는 만큼 본 연구의 목적은 우리나라의 FTA를 통한 기술무역에 대한 현황 및 전략적 대웅방안을 모색해 보는데 있다. 우리나라가 체결한 FTA, 즉, 한-칠레, 한-EFTA, 한-Asean, 한-인도, 한-EU 이렇게 5개 그룹으로 분류한 FTA발효국만을 대상으로 각각 5년간 기술무역 수지 및 산업별, 기술유형별 중심으로 기술무역수지를 살펴보기로 한다. 또한 이러한 5개 그룹 FTA국과의 기술무역 장애요인 및 기술무역 활성화방안을 모색하였다.

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퍼지 분류자 시스템을 이용한 퍼지 규칙의 학습 (Learning of Fuzzy Rules Using Fuzzy Classifier System)

  • 정치선;심귀보
    • 전자공학회논문지CI
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    • 제37권5호
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    • pp.1-10
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    • 2000
  • 본 논문에서는 연속적인 입력을 연속적인 출력으로 매핑하는 것을 가능하게 하는 퍼지 분류자 시스템을 제안한다. 퍼지 분류자 시스템은 기계학습의 방법을 퍼지 제어기의 개념에 적용한 것이다. 즉 분류자의 조건부와 행동부는 퍼지 규칙에서의 전건부와 후건부와 같은 형태이다. 퍼지 분류자 시스템은 입력 값을 퍼지화된 메시지로 변환하고 메시지 리스트에 저장한다. 저장된 메시지와 퍼지 분류자 리스트의 분류자들과 정합과정을 통해 룰-베이스를 구성하고, 버킷 릴레이 알고리즘을 적용하여 퍼지 분류자들의 유용성을 검증한다. 또한 유전 알고리즘을 사용하여 새로운 규칙을 생성하거나 규칙을 수정하여 시스템의 성능을 향상시킨다. 이러한 과정을 통해 유용한 규칙집합을 찾아낸다. 제안된 퍼지 분류자 시스템을 자율이동로봇의 목적지 지향과 충돌 회피 학습에 적용하여 그 유용성을 확인하였다.

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수동운전(ATS)구간에서 PSD 적용 기술의 성공적 요인 분석연구 (A Study of Successful Factor on PSD Application Technique for Manual Operation Mode(ATS))

  • 손영진;박근수;민경윤
    • 한국철도학회논문집
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    • 제10권1호
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    • pp.57-66
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    • 2007
  • 1974. 8. 15 SeoulMetro, beginning with the first electric railway established at six cities, so it is managing mass transportation of traffic. Especially, in case of seoul, It is managing that from one to eight lines, 286.9km, 265 stations have installed and now it is carrying about 5.5million of passengers everyday, and 2,000million passengers a year. So accident is increasing from the station every year. For this measure, SeoulMetro prepares safety fence for passengers crash but, as suicides or people who watch the accident took place, for at the bottom of passengers crash protection, PSD installing is needed. Even though, PSD is managing ATO section but, in controlling SeoulMetro, one to four lines sections are (ATS, ATC)section. Between as ATS, ATC section, ATO section, subway gate and PSD must have opened and crossed always at the time. And the interlock control corrosion protection gate, managing skills with installation, method, using in history, apply to 10rail cars one train sets, and maximum applying 2224% sections of passengers congested that consideration is to be needed. So 2004, SeoulMetro improved technology and basie design of PSD at ATS section. Based on this, from 2005.4 to 2006.6, using subway 2lines per 12stations set the model installation(full type 11stations, half type 1station) After installing in case of success, it is going about to suggest that effective analysis and hereafter subject.

Establishment of CTE Measurement Procedure for PPLP at 77 K for HTS Power Cables using Double Extensometers

  • Dedicatoria, Marlon J.;Dizon, John Ryan C.;Shin, Hyung-Seop;Sim, Ki-Duk
    • 한국초전도ㆍ저온공학회논문지
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    • 제14권4호
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    • pp.24-27
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    • 2012
  • The measurement of the coefficient of thermal expansion (CTE) of polypropylene laminated paper (PPLP) as electric insulating material is important for its practical superconducting device application. The thermal strain induced to HTS tapes and its insulating material during cooling from room temperature might largely affect the critical current ($I_c$) of HTS tapes. In this study, the thermal contraction of PPLP material was measured during cooling from 300 K to 77 K using double extensometers. Initially, the CTE of a brass tape was measured and it was compared with a reference data. It was found that the measured thermal expansion data of the brass material approaches that of the reference one. Based on the results, it was then confirmed that the measurement technique could be applied to thin and flexible samples. Therefore, the same measurement procedure was applied to PPLP material using double extensometers. As a result, the linear CTE of the PPLP at 77 K has been measured to be ${\sim}15.3{\times}10^{-6}/K$. Also, it was found that the thermal contraction characteristics of PPLP was dominated by polypropylene on the cross direction (higher thermal contraction) while it was dominated by Kraft paper on the machine direction (lower thermal contraction). Overall, this measurement procedure could be adopted for the determination of CTE of flexible materials such as PPLP.

정전기 방전 평가를 위한 간이형 도구 개발에 관한 연구 (A Study on the Development of Simulating Tool for Evaluation of Electrostatic Discharge)

  • 최상원
    • 한국안전학회지
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    • 제26권3호
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    • pp.15-22
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    • 2011
  • Explosion and fire cause about 30 reported industrial major accidents a year by ignition source which discharge of electrostatic generated to flammable gas, vapor, dust and mixtures. It brings economically and humanly very large loss that accident was caused by fire and explosion from electrostatic discharge. Thus, it is very important that electrostatic discharge energy is to be control below not to be igniting flammable mixtures. There are two kinds of analysis model for electrostatic discharge, human body model and machine model. Human body model is available the parameter of human's electrical equivalent that capacitance is 100 pF, resistance is $1.5k{\Omega}$. To simulate and visualize the electrostatic discharge from human body need a very expensive and high voltage simulator. In this paper, we measured the value of capacitance and resistance concerned with test materials and sizing of specimen and the value of charged voltage concerned with test specimen and distance to develop an electrostatic charge/discharge simulating tool for teaching with which concerned industrial employee and students. The result of experiments, we conformed that the minimum ignition energy of methane-oxygen mixtures meets well the equation $W=1/2CV^2$, and found out that the insulating material and sizing of equivalent value having human body mode are the poly ethylene of 200 mm and 300 mm of diameter. Developed electrostatic charge/discharge simulating tool has many merits; simple mechanism, low cost, no need of electric power and so on.

PLC 내장형 무인 반송차(AGV) 제어기 설계 (Design of Automatic Guided Vehicle Controller with Built-in Programmable Logic Controller)

  • 이주원;이병로
    • 융합신호처리학회논문지
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    • 제20권3호
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    • pp.118-124
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    • 2019
  • 최근 산업현장에서는 생산성, 품질, 고객 만족도를 향상시키기 위해 정보통신기술(ICT)을 기반으로 한 스마트 팩토리 체제로 전환하고 있다. 스마트 팩토리를 실현함에 있어 가장 중요한 장치는 무인 반송차(AGV)이며, AGV의 도입이 증가하고 있다. 일반적으로 AGV은 범용 PLC를 이용하여 개발하고 있으나, 범용 PLC로 개발된 AGV의 가격은 고가이며, 부피 또한 크다. 한편, 산업현장에서는 작업장의 공간적 제약 때문에 소형화, 용이한 재구성 등이 가능한 저가의 AGV를 요구하고 있다. 따라서 본 연구에서는 이러한 문제점을 해결하기 위해 PLC 내장형 AGV 제어기의 설계법을 제안하고, 그 성능을 평가하였다. 그 결과, 우수한 속도제어와 주행 정밀도(속도제어 오차=0.021[m/s], 주행자세제어의 평균오차 = 2.1[mm])를 보였다. 이와 같이 제안된 AGV 제어기를 산업현장에 적용한다면, 저비용으로 소형화와 재구성 등이 가능할 것이다.

Thermal properties and mechanical properties of dielectric materials for thermal imprint lithography

  • Kwak, Jeon-Bok;Cho, Jae-Choon;Ra, Seung-Hyun
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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    • pp.242-242
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    • 2006
  • Increasingly complex tasks are performed by computers or cellular phone, requiring more and more memory capacity as well as faster and faster processing speeds. This leads to a constant need to develop more highly integrated circuit systems. Therefore, there have been numerous studies by many engineers investigating circuit patterning. In particular, PCB including module/package substrates such as FCB (Flip Chip Board) has been developed toward being low profile, low power and multi-functionalized due to the demands on miniaturization, increasing functional density of the boards and higher performances of the electric devices. Imprint lithography have received significant attention due to an alternative technology for photolithography on such devices. The imprint technique. is one of promising candidates, especially due to the fact that the expected resolution limits are far beyond the requirements of the PCB industry in the near future. For applying imprint lithography to FCB, it is very important to control thermal properties and mechanical properties of dielectric materials. These properties are very dependent on epoxy resin, curing agent, accelerator, filler and curing degree(%) of dielectric materials. In this work, the epoxy composites filled with silica fillers and cured with various accelerators having various curing degree(%) were prepared. The characterization of the thermal and mechanical properties wasperformed by thermal mechanical analysis (TMA), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), rheometer, an universal test machine (UTM).

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선삭가공에 있어서 절삭저항의 동적성분에 관한 연구 [I] -동적성분에 의한 Chip배출상태의 인식- (A Study on the Dynamic Component of Cutting Force in Turning[1] -Recognition of Chip Flow by the Dynamic Cutting Force Component-)

  • 정의식
    • 한국정밀공학회지
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    • 제5권1호
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    • pp.84-93
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    • 1988
  • The on-line detection of the chip flow is one of the most important technologies in com- pletly automatic operation of machine tool, such as FMS and Unmanned Factories. This problem has been studied by many researchers, however, it is not solved as yet. For the recognition of chip flow in this study, the dynamic cutting force components due to the chip breaking were measured by dynamometer of piezo-electric type, and the frequency components of cutting force were also analyzed. From the measured results, the effect of cutting conditions and tool geometry on the dynamic cutting force component and chip formation were investigated in addition to the relationships between frequency of chip breaking (fB) and side serrated crack (fC) of chip. As a result, the following conclusions were obtaianed. 1) The chip formations have a large effect on the dynamic cutting force components. When chip breaking takes place, the dynamic cutting force component greatly increases, and the peridoic components appear, which correspond to maximum peak- frequency. 2) The crater wear of tool has a good effect on the chip control causing the chiup to be formed as upward-curl shape. In this case, the dymamic cutting force component greatly increases also 3) fB and fC of chip are closely corelated, and fC of chips has a large effect on the change of the situation of chip flow and dynamic cutting force component. 4) Under wide cutting conditions, the limit value (1.0 kgf) of dynamic cutting force component exists between the broken and continuous chips. Accordingly, this value is suitable for recognition of chip flow in on-line control of the cutting process.

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공백행의 중심점 추출에 의한 고속 문서 기울기 검출 (Fast Skew Detection of Document Images by Extraction of Center Points of Blank Lines)

  • 정재영;김문현
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제26권11호
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    • pp.1342-1349
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    • 1999
  • 본 논문에서는 문서 내의 인접한 두 행 사이에는 일정한 두께의 공백 행이 존재하며 그 공백 행의 기울기는 실제 문서의 기울어진 정도를 반영한다는 사실에 기반하여, 선형적으로 기울어진 문서 영상의 기울기 추정을 위한 고속의 알고리즘을 제안한다. 먼저, 간단한 모폴로지 연산(dilation)을 이용하여 문자행 영역과 공백행 영역을 분리한 후, 이를 일정 간격으로 수직 샘플링하여 수직선 상에 있는 모든 공백행의 중심점(행간점)을 찾는다. 동일한 공백 행 상에 있는 인접한 두 행간점 간에 기울기를 계산하고, 전체 영상으로부터 이들의 분포를 조사하여 최대 빈도를 가지는 기울기를 입력 문서의 기울기로 추정한다. 실험에서는 제안한 알고리즘을 필기체 및 인쇄체를 포함하는 다양한 형태의 가로쓰기 문서에 적용한 결과를 보인다.Abstract In this paper, we propose a fast algorithm to estimate the skew angle of linearly skewed document images. This paper is based on the fact that there is a blank line with uniform thickness between two adjacent text lines and the slope of the line is the same as that of the document. Firstly, we apply a dilation operation to the image to separate blank lines from text lines, and we detect center points of blank lines along the vertically sampled lines. Then we calculate the slope between neighboring center points in the same blank line. Calculated slopes for the entire image are accumulated on the histogram to display the distribution of them. Finally, the peak in the histogram is detected and estimated as the slope of the document image. In the experiments, we adopted a lot of images of various format with hand-printed or machine-printed document to verify our algorithm.

열화상 이미지 분석을 통한 배전 설비 공정능력지수 감지 시스템 개발 (Identifying Process Capability Index for Electricity Distribution System through Thermal Image Analysis)

  • 이형근;홍용민;강성우
    • 품질경영학회지
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    • 제49권3호
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    • pp.327-340
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    • 2021
  • Purpose: The purpose of this study is to propose a system predicting whether an electricity distribution system is abnormal by analyzing the temperature of the deteriorated system. Traditional electricity distribution system abnormality diagnosis was mainly limited to post-inspection. This research presents a remote monitoring system for detecting thermal images of the deteriorated electricity distribution system efficiently hereby providing safe and efficient abnormal diagnosis to electricians. Methods: In this study, an object detection algorithm (YOLOv5) is performed using 16,866 thermal images of electricity distribution systems provided by KEPCO(Korea Electric Power Corporation). Abnormality/Normality of the extracted system images from the algorithm are classified via the limit temperature. Each classification model, Random Forest, Support Vector Machine, XGBOOST is performed to explore 463,053 temperature datasets. The process capability index is employed to indicate the quality of the electricity distribution system. Results: This research performs case study with transformers representing the electricity distribution systems. The case study shows the following states: accuracy 100%, precision 100%, recall 100%, F1-score 100%. Also the case study shows the process capability index of the transformers with the following states: steady state 99.47%, caution state 0.16%, and risk state 0.37%. Conclusion: The sum of caution and risk state is 0.53%, which is higher than the actual failure rate. Also most transformer abnormalities can be detected through this monitoring system.