• Title/Summary/Keyword: pre-inspection

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A Study on the DC Leakage Current Test for Power Cable of Private Electrical Facilities considering Lightning Arrester (피뢰기를 고려한 자가용 전기설비 인입선로의 직류누설전류시험에 관한 연구)

  • Jeong, Ki-Seok;Gil, Hyoung-Jun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.1
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    • pp.142-147
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    • 2018
  • Private electrical facilities are judged whether it is suitable for the insulation aging condition of their incoming underground cables using DC leakage current test method. In the case where the service point of utility is the secondary side of cut out switch installed in the electric pole, there is a problem that it is difficult to separate the lightning arresters(LA) because of their high position of the pole. Therefore, the field test voltage is applied at value lower than DC 30 kV, which are stated in the inspection guideline. However, this test could reduced the insulation performance of the LA by accelerating the electrical stress of the metal oxide varistor element in the pre-breakdown region. In this study, we analyzed the relationship between the DC test voltage and the leakage current using the non-destructive DC high voltage equipment with leakage current measurement function. The results show that the leakage current increases sharply above the specified test voltage. As a consequence, it could be contributed to improve insulation aging inspection method by selecting the possible test area on the VI characteristic curve of the pre-breakdown area of the LA.

A Study on tests process for verification of AC Traction system performance (교류 급전시스템 성능검증을 위한 시험방안에 관한 연구)

  • Jung, Ho-Sung;Lee, Ki-Won;Kim, Joo-Rak;Han, Moon-Seob;Kim, Jin-Hee
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.2202-2203
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    • 2011
  • AC substation of urban transit supplies a suitable AC power on electricity vehicles. AC substation is verified electrical safety of system through pre-operation inspection on electrical installations to be supplied power from KEPCO. However, because test items and method for AC traction system are unprepared on pre-operation inspection, the general safety and performance verification of AC traction system are very insufficient. Therefore this paper analyze the test examples such as factory equipment tests, factory combined tests and railway tests for the safety and performance verification of AC traction system and present a suitable test items and test standard in domestic.

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Frequency Domain Pre-Processing for Automatic Defect Inspection of TFT-LCD Panels (TFT-LCD 패널의 자동 결함 검출을 위한 주파수영역 전처리)

  • Nam, Hyun-Do;Nam, Seung-Uk
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.7
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    • pp.1295-1297
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    • 2008
  • Large-sized flat-panel displays are widely used for PC monitors and TV displays. In this paper, frequency domain pre-filter algorithms are presented for detection of defects in large-sized Thin Film Transistor-Liquid Crystal Display(TFT-LCD) panel surfaces. Frequency analysis with 1-D, 2-D FFT methods for extract the periodic patterns of lattice structures in TFT-LCD is performed. To remove this patterns, frequency domain band-stop filters were used for eliminating specific frequency components. In order to acquire only defected images, 2-D inverse FFT methods to inverse transform of frequency domain images were used.

An analysis of tests process for verification of DC Traction system performance (직류 급전시스템 성능검증을 위한 시험방안 분석)

  • Jung, Ho-Sung;Han, Moon-Seob;Jang, Dong-Uk;Lee, Ki-Won
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.499-504
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    • 2008
  • DC substation of urban transit supplies a suitable DC power on electricity vehicles by being supplied from KEPCO. DC substation is verified electrical safety of system through pre-operation inspection on electrical installations to be supplied power from KEPCO. However, because test items and method for DC traction system are unprepared on pre-operation inspection, the general safety and performance verification of DC traction system are very insufficient. Therefore this paper analyze the overseas test examples such as factory equipment tests, factory combined tests and railway tests for the safety and performance verification of DC traction system and present a suitable test items and test standard in domestic.

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Research on Pre-service Inspection on Electrical Installations for Private Use based on Self-reliance (자가용전기설비의 사용전 자율검사제도 도입추진방안)

  • Kim, Han-Young;Ryu, Gi-Hyeon;Hwang, Min-Su
    • Proceedings of the KIEE Conference
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    • 2005.07e
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    • pp.112-114
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    • 2005
  • It is obvious that electrical safety cannot be secured soley by the efforts from public sector including government. With the global trend of deregulation as WTO/TBT agreement comes into effect, foreign countries strive to minimize unnecessary and inefficient regulations in every field by sharing responsibilities with the privae sector to secure international competency in trade. To this same end, in this paper 2 level approach plan is suggested to pave the way to the self-security system in electrical field by introducing self-reliance safety system by stage for pre-service inspection on the electrical installations for private use based on product requirements in terms of performance.

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Automatic Safety Inspection Technique for Ammunition Fuzes using Radiographic Images (방사선 영상을 이용한 탄약신관 안전상태 자동인식기술 개발)

  • An, Ji Yeon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.18 no.3
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    • pp.283-292
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    • 2015
  • This paper presents the development of the automatic safety inspection technique for the ammunition fuzes using radiography images. The technique inspects 49-ammunition fuze by detecting the X-ray or neutron radiographic images to check whether the fuze is unintendedly armed or/and some major assembled parts are at right place. To execute the program, we loads the image(s) for under test. After reading images, the program conducts a series of pre-image processing, and then starts inspecting input images by using the detection algorithms which are designed distinctively for each fuze. After completing the detection process, the program displays the final result of the fuze status: "safety or danger." Through this program, we can cut off the fuzes which have any doubt about safety, and can only provide absolutely safe fuzes, compared with the current naked eye inspection method.

A Study on the Development of Work Activity Check List by Factor Analysis (요인분석을 통한 공종별 체크리스트 작성에 관한 연구)

  • 이재옥;윤여완;김천학;양극영
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2002.11a
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    • pp.95-98
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    • 2002
  • The purpose of this study was to Estimation the Risk of construction method to protect and reduce the risk of construction period. For this study we are using the pre and during construction period Inspection list. The inspection list was used by construction company for check a flaw of construction field. So we rearrange the individual item of inspection list to match the Risk factor, The results of this study were as follows: The inspection list was rearranged at Risk checklist for Risk estimation. So that we estimate the Risk of individual construction method.

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Semiconductor Process Inspection Using Mask R-CNN (Mask R-CNN을 활용한 반도체 공정 검사)

  • Han, Jung Hee;Hong, Sung Soo
    • Journal of the Semiconductor & Display Technology
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    • v.19 no.3
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    • pp.12-18
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    • 2020
  • In semiconductor manufacturing, defect detection is critical to maintain high yield. Currently, computer vision systems used in semiconductor photo lithography still have adopt to digital image processing algorithm, which often occur inspection faults due to sensitivity to external environment. Thus, we intend to handle this problem by means of using Mask R-CNN instead of digital image processing algorithm. Additionally, Mask R-CNN can be trained with image dataset pre-processed by means of the specific designed digital image filter to extract the enhanced feature map of Convolutional Neural Network (CNN). Our approach converged advantage of digital image processing and instance segmentation with deep learning yields more efficient semiconductor photo lithography inspection system than conventional system.

A Study on the Risk Analysis of Construction Method (건축공법 내부 리스크 분석에 관한 연구)

  • 윤여완;양극영
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2002.11a
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    • pp.117-121
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    • 2002
  • The purpose of this study was to Identification the Risk of construction method to protect and reduce the risk of construction period. For this study we are using the pre and during construction period Inspection list. The inspection list was used by construction company for check a flaw of Construction field. So we rearrange the individual item of inspection list to match the Risk factor. This inspection list usually has the difference of importance because this list is not made by Method which is not focused on Method. Therefore, To find the difference of these importance, We surveyed this matter by doing interview of specialist group. To find the application of field and the possibility of measurement of Risk status, We tested Risk occurring frequency and it's strength by checking the level of Risk. The results of this study were as follows; Each Method Check List made out through the rearrangement of Construction Inspection list which used in construction company. To solve and compensate the matter which happened by changing the each Method Check List to each General Inspection List, we added the each Method Check List by checking the importance of check list of each process. By doing this, The Check List for finding Risk level of Method was created by using the check list of each Method.

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A Study on the Risk Analysis of Construction Method (건축공법 내부 리스크 분석에 관한 연구)

  • Yoon, Yer-Wan;Yang, Keek-Young
    • Journal of the Korea Institute of Building Construction
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    • v.2 no.4
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    • pp.131-135
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    • 2002
  • The purpose of this study was to Identification the Risk of construction method to protect and reduce the risk of construction period. For this study we are using the pre and during construction period Inspection list. The inspection list was used by construction company for check a flaw of Construction field. So we rearrange the individual item of inspection list to match the Risk factor. This inspection list usually has the difference of importance because this list is not made by Method which is not focused on Method. Therefore, To find the difference of these importance, We surveyed this matter by doing interview of specialist group. To find the application of field and the possibility of measurement of Risk status, We tested Risk occurring frequency and it's strength by checking the level of Risk. The results of this study were as follows; Each Method Check List made out through the rearrangement of Construction Inspection list which used in construction company. To solve and compensate the matter which happened by changing the each Method Check List to each General Inspection List, we added the each Method Check List by checking the importance of check list of each process. By doing this, The Check List for finding Risk level of Method was created by using the check list of each Method.