• 제목/요약/키워드: Current collection quality

검색결과 133건 처리시간 0.03초

블럭펄스함수를 이용한 판토그래프와 가선시스템사이의 동특성 해석 (The Dynamic Characteristics Analysis Between Pantograph and Catenary System Using Block Pulse Function)

  • 신숭권;송용수;엄주환;엄기영
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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    • pp.748-750
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    • 2004
  • The pantograph should supply the electrification equipments of a train with the current from the overhead catenary system over a broad range of speeds. For a high-speed electrical train, the dynamic interaction between the pantograph and the overhead catenary system causes the variation of the contact force. As the operational speed increases, the variation of the contact force increases. The contact force variation can cause contact losses, arcing and sparking. If the spark happens between the pantograph and the overhead catenary system, the EMI(electro magnetic interface) and noises may occur. After all, the quality of current collection is deteriorated. This paper deals with the dynamic characteristics analysis between pantograph and catenary system using block pulse function.

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Quality Enhancement of MIROS Wave Radar Data at Ieodo Ocean Research Station Using ANN

  • Donghyun Park;Kideok Do;Miyoung Yun;Jin-Yong Jeong
    • 한국해양공학회지
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    • 제38권3호
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    • pp.103-114
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    • 2024
  • Remote sensing wave observation data are crucial when analyzing ocean waves, the main external force of coastal disasters. Nevertheless, it has limitations in accuracy when used in low-wind environments. Therefore, this study collected the raw data from MIROS Wave and Current Radar (MWR) and wave radar at the Ieodo Ocean Research Station (IORS) and applied the optimal filter by combining filters provided by MIROS software. The data were validated by a comparison with South Jeju ocean buoy data. The results showed it maintained accuracy for significant wave height, but errors were observed in significant wave periods and extreme waves. Hence, this study used an artificial neural network (ANN) to improve these errors. The ANN was generalized by separating the data into training and test datasets through stratified sampling, and the optimal model structure was derived by adjusting the hyperparameters. The application of ANN effectively improved the accuracy in significant wave periods and high wave conditions. Consequently, this study reproduced past wave data by enhancing the reliability of the MWR, contributing to understanding wave generation and propagation in storm conditions, and improving the accuracy of wave prediction. On the other hand, errors persisted under high wave conditions because of wave shadow effects, necessitating more data collection and future research.

Depth-dependent EBIC microscopy of radial-junction Si micropillar arrays

  • Kaden M. Powell;Heayoung P. Yoon
    • Applied Microscopy
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    • 제50권
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    • pp.17.1-17.9
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    • 2020
  • Recent advances in fabrication have enabled radial-junction architectures for cost-effective and high-performance optoelectronic devices. Unlike a planar PN junction, a radial-junction geometry maximizes the optical interaction in the three-dimensional (3D) structures, while effectively extracting the generated carriers via the conformal PN junction. In this paper, we report characterizations of radial PN junctions that consist of p-type Si micropillars created by deep reactive-ion etching (DRIE) and an n-type layer formed by phosphorus gas diffusion. We use electron-beam induced current (EBIC) microscopy to access the 3D junction profile from the sidewall of the pillars. Our EBIC images reveal uniform PN junctions conformally constructed on the 3D pillar array. Based on Monte-Carlo simulations and EBIC modeling, we estimate local carrier separation/collection efficiency that reflects the quality of the PN junction. We find the EBIC efficiency of the pillar array increases with the incident electron beam energy, consistent with the EBIC behaviors observed in a high-quality planar PN junction. The magnitude of the EBIC efficiency of our pillar array is about 70% at 10 kV, slightly lower than that of the planar device (≈ 81%). We suggest that this reduction could be attributed to the unpassivated pillar surface and the unintended recombination centers in the pillar cores introduced during the DRIE processes. Our results support that the depth-dependent EBIC approach is ideally suitable for evaluating PN junctions formed on micro/nanostructured semiconductors with various geometry.

국가 수준 평생교육 정보시스템의 회원 정보 수집 현황 분석 (Analysis of Member Information Collection in the National Level of Lifelong Education Information System)

  • 범상윤;정영식
    • 한국정보교육학회:학술대회논문집
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    • 한국정보교육학회 2021년도 학술논문집
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    • pp.247-252
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    • 2021
  • Coursera, edX 등 원격 교육 플랫폼으로 촉발된 온라인 교육의 질적 성장으로 온라인 플랫폼을 통한 평생교육의 수요가 증가하였다. 이에 부응하여, 우리나라도 정부 기관, 지자체에서 다양한 평생교육 지원 제도와 사이트를 만들었다. 각 지원 제도와 사이트의는 각각의 회원 정보 수집 체계를 만들었다. 학습자의 정보를 체계적으로 수집하고 이용하기 위해서는 각 시스템들의 통합된 회원 관리 체계가 필요하다. 따라서 국가 수준의 평생교육 지원 시스템들의 회원 정보 수집 현황을 분석하였다. 이를 바탕으로 시스템들이 공통적으로 수집하는 회원정보와 개별적으로 수집하는 정보를 구분한다. 통합 회원 체계의 바탕이 되는 항목들을 갈무리하는 데 도움을 줄 것이다.

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암 관련 삶의 질 평가도구에 관한 연구 현황 (Current Status of Studies on Cancer-Related Quality of Life Instruments)

  • 조정효;손창규;이연월;유화승;성정현;김소영;이명민;강위창;조종관
    • 대한한방내과학회지
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    • 제27권1호
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    • pp.84-91
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    • 2006
  • The importance of measurement of health-related quality of life (HRQL) cannot be overemphasized. However, efforts to implement HRQL measurement often fail because of differences in definition and insufficient information about available measures. In this paper, many available HRQL measures are reviewed, which have been designed for, or frequently used with, people with cancer in order to aid in the evaluation of effects of oriental medicine on cancer patients. A total of 28 articles were selected from three different databases. The selected articles were analyzed according to three aspects of application of the Korean version of HRQL measures, namely generic, disease specific and symptoms related instruments. Nine HRQL measures are completed with Korean validation and data collection under contact and permission of the author. However, research studies that reported data on quality of life (QOL) in cancer patients treated with oriental medicine were wholly lacking. It is recommended that further studies be performed, using methods of data collection whose validity and reliability has been confirmed.

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교육의 질 관리를 위한 의과대학 코호트 구축과 운영: 건양대학교 의과대학 사례 (Design and Implementation of a Cohort for Quality Management of Medical Education: A Case Study from Konyang University College of Medicine)

  • 천경희;이태희;정수진;박영순
    • 의학교육논단
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    • 제25권2호
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    • pp.102-108
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    • 2023
  • This study shares details on the operating process and results of the cohort of students and graduates that was designed and implemented at Konyang University College of Medicine in Daejeon and discusses future directions for cohort establishment and improvement. First, Konyang University College of Medicine established the necessity and defined the purpose of cohort design and implementation. A task force was formed to establish guidelines for analysis targets, procedures, reports, and data management, and cohort operation was classified as a quality control activity. Data were collected through surveys of current students and graduates, and data generated during the curriculum were collected, analyzed, and reported every 2 years. The cohort data collection and analysis methods are designed by the Department of Medical Education, and data collection is carried out by the administrative team and each committee. Data management and analysis are handled by the Center for Medical Education Support, and analysis and reporting are conducted by the Department of Medical Education. Various members of the medical school are working to collect and analyze data, report findings, provide feedback, and improve. In the future, we plan to advance database computerization and work toward more effective data analysis. Cohort operation should not be another burden for medical schools; instead, it is hoped that operating cohorts will be a meaningful activity to increase the effectiveness of medical education and help in the operation and policy decisions of medical schools.

국방분야 품질정책 고도화를 위한 군수품 생산업체 품질경영수준 조사 및 분석 (A Survey and Analysis of Defense Industry Quality Management Level for Advancement of Defense Quality Policy)

  • 노태주;서상원
    • 산업경영시스템학회지
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    • 제40권3호
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    • pp.18-26
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    • 2017
  • Defense industries which require high reliability need an optimized quality management system with well-planned implementation. And the government should examine the overall status of defense industries, then establish practical policies with a proper support plan in required areas to upgrade the quality management level of manufacturers. Thus, DTaQ developed the model for 2 years from 2014, which specialized in quality management level analysis for defense industries. And a survey has been undertaken with that model by DTaQ and Korea Research Center in 2016. The surveyed companies randomly sampled among those which have more than 30 employees and delivery history over past 3 years, and finally 106 defense industries were selected. This paper present survey method and indexes for survey of defense industry quality management level. The survey was conducted in the order of planning, data collection and data processing, and the validity and reliability of the data were verified to increase objectivity of survey results. The survey contents mainly consist of system quality and management quality. System quality includes Product Development Management, Production Operation Management, supply chain quality management, Safety & Environment Management and Reliability Management, on the other hand, management quality includes Strategic Leadership, Human Resource Management, Customer Market Management and Information & Knowledge Management. Thus this proposes the current overall quality management status of the 106 defense industries and shows level differences by company sizes and manufacturing sectors based on the result of survey. Specifically, this paper enables to track the areas which need prompt government support with the policy directions to make quality management level higher. Therefore, it is expected that this can be used as reference data in establishing quality policies for military supplies in the future.

참깨 품질 연구의 현황과 문제점 및 전망 (Current Status and Perspectives of Quality Improvement in Sesame)

  • 이봉호;이정일;박래경
    • 한국작물학회지
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    • 제33권s01호
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    • pp.86-97
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    • 1988
  • Sesame(Sesamum indicum L.) is probably the most ancient oilseed crop known in the world. The seed of sesame is used in a variety of ways as food. The whole seed may be eaten raw, either roasted or parched, or fed to birds and stock. Sesame oil is used as a salad or cooking oil, in shortening, margarine and in the manufacture of soap. Minor uses are as a fixative in the perfume industry and formerly as a carrier for fatsoluble substances in pharmaceuticals such as penicillin. One of the minor constituents of sesame oil, sesamin, is used for its synergistic effect in pyrethrin insecticides, in addition of a small quantity of this substance markedly increases the effectiveness of fly sprays. The meal remaining after oil extraction can be used as and animal feed-stuff or as manure. In general sesame meal is considered to be equal to cottonseed or soybean meal as a protein supplement for livestock and poultry. It is especially high in certain amino-acids such as methionine, which is low in soybean meal, and thus can be combined with it or similar meal to form a more balanced ration. An attempt to summarize the literature review on quality improvement of sesame was made to discuss the accomplishments of the past and perspectives in the future. The reviews on quality improvement of sesame were mainly discussed in connection with the cultural practices and genetic informations in current status. The emphasis focussed on environmental variation of quality in cultural practices, such as harvest time, variety by location, climatic condition, fertilizer application, and growth regulator treatment. On the genetic variation of quality, it was discussed on variety background, mutation breeding, correlations, and inheritance of quality related characteristics. It also was discussed on relationship between quality and plant traits, storage condition or period, and seed coat color. Moreover, current research status were reviewed on some minor elements such as sesamin, oxalic acid, and trypsin inhibitor. As a results of the review, the lack of an effort to quality improvement in each utilization area was indicated as a problem area. More active efforts for the improvement of quality were also insufficient to incorporate the available genes for quality in breeding method or collection and analysis of breeding materials. Therefore, researches in the future would be recommended to emphasize on these problem areas.

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Recent Insights from the International Common-Cause Failure Data Exchange Project

  • Kreuser, Albert;Johanson, Gunnar
    • Nuclear Engineering and Technology
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    • 제49권2호
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    • pp.327-334
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    • 2017
  • Common-cause failure (CCF) events can significantly impact the availability of safety systems of nuclear power plants. For this reason, the International Common Cause Data Exchange (ICDE) project was initiated by several countries in 1994. Since 1997 it has been operated within the Organisation for Economic Co-operation and Development (OECD)/Nuclear Energy Agency (NEA) framework and has successfully been operated over six consecutive terms (the current term being 2015-2017). The ICDE project allows multiple countries to collaborate and exchange CCF data to enhance the quality of risk analyses, which include CCF modeling. As CCF events are typically rare, most countries do not experience enough CCF events to perform meaningful analyses. Data combined from several countries, however, have yielded sufficient data for more rigorous analyses. The ICDE project has meanwhile published 11 reports on the collection and analysis of CCF events of specific component types (centrifugal pumps, emergency diesel generators, motor operated valves, safety and relief valves, check valves, circuit breakers, level measurement, control rod drive assemblies, and heat exchangers) and two topical reports. This paper presents recent activities and lessons learnt from the data collection and the results of topical analysis on emergency diesel generator CCF impacting entire exposed population.

뿌리기업 스마트공장 구축 현황과 영향관계 분석 (Investigation of Factors for Smartization of Ppuri Enterprises Based on the Smart Factory Status)

  • 김보경;이상목;김태범;김택수;김창경
    • 한국분말재료학회지
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    • 제29권2호
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    • pp.166-175
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    • 2022
  • Ppuri or Root technology primarily includes technologies such as casting, mold, plastic working, welding, heat treatment and surface treatment. It is regarded as an essential element for improving the competitiveness of the quality of final products. This study investigates the current status of smart factory implementation for Ppuri companies and analyzes the influencing relationships among various company factors. The factors affecting smart factory implementation for Ppuri companies are sales, exports, number of technical employees, and holding corporate research institutes. In addition, this research shows that even if smart factory implementation is pursued for data collection, data utilization is not implemented properly. Thus, it is suggested that the implementation of smart factories requires not only the availability of facilities and systems but also proper data utilization.