• Title/Summary/Keyword: Operating history

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A Study on the Fatigue Crack Evaluation Method of Railway Bogie Frame (철도차량 대차를 피로균열 평가법 연구)

  • Jun, Hyun-Kyu;Seo, Jung-Won;Lee, Dong-Hyong;Kim, Hyeong-Jin
    • Journal of the Korean Society for Railway
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    • v.12 no.1
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    • pp.16-24
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    • 2009
  • In this study, fatigue crack growth rate of a cracked railway bogie frame under variable amplitude loading is predicted by applying linear elastic fracture mechanics. For this purpose, we find the critical points by reference surveying on cracked railway bogie frames. And we make an effective load history by synthesizing the dynamic load measured from the critical points of railway bogie frame during commercial line operation and the static load calculated from structural analysis. Crack growth analyses are performed at the 3 critical points under the commercial operation loading condition by assuming an initial crack size as 40 mm. and the results are compared with the experimental results from Japanese railway bogie frame crack growth case. From the analysis results, we find that around 500,000 km operating distance is necessary to bring crack growth from the initial crack to unstable crack. And it takes around 3.8 normal operating years. We conclude that it is enough time to detect the crack between normal maintenance period.

Reset of Measurement Control Criteria for Monitoring Data through the Analysis of Measured Data (계측데이터 분석을 통한 모니터링 데이터의 계측관리기준 재설정)

  • Chung, Chul-Hun;An, Ho-Hyun;Shin, Soo-Bong;Kim, Yu-Hee
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.6
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    • pp.105-113
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    • 2014
  • Most operating civil structures measure response data continuously by various types of sensors and evaluate their health conditions. Measurement control criteria for such civil structures are usually defined in the first operating stage by experts working at a construction or engineering company. However, a few studies have been carried to examine the adequacy of these measurement control criteria based on the actual measured data. The paper introduces a systematic way of resetting the measurement control criteria for the measured monitoring data based on the statistical aspects of the measured data. The proposed statistical approach has been examined with actually measured time-history data from a bridge structure.

Quantitative Analysis of Workload for Classifying the Operating Area of Distribution Control Center (배전관제센터의 운전영역 구분을 위한 정량적 업무량 분석)

  • Go, Seok-Il;Seo, Dong-Kwen;Choi, Joon-Ho;Ahn, Seon-Ju;Kim, Hyun-Woo;Yun, Sang-Yun
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.67 no.4
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    • pp.200-207
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    • 2018
  • In recent, KEPCO (Korea Electric Power Corporation) faced difficulties of the DCC (distribution control center) due to the increase of field equipment and operational cost, and aging of operating staffs. In response to these changes in the DCC, KEPCO is trying to change the organization and system of the DCC. In this paper, we present a new attempt to change organization and structure of distribution control center, which was implemented by KEPCO recently. This paper is divided into three major parts. First, to examine the adequacy of the divided basis of current DCCs based on the quantity of installed electrical equipment, we analyzed the correlation between the operational history of the DCCs and the number of equipment. Through the analysis, we confirmed that there is little relationship between the number of equipment and actual workload. Second, we conducted visits and questionnaire surveys of all the DCCs to identify factors affecting the actual workload of distribution operators and then summarized the results. Third, based on this survey, a general formula for analyzing the workload of a DCC was derived, and each DCC's average annual total workload, day/night workload, and required number of personnel were calculated. Through this study, we proposed a more realistic management method of DCCs that can overcome the division criteria based on equipment quantity.

A Study in the legal standards of healthcare facilities in Korea, China, and Japan (한국·중국·일본의 의료시설 법적기준과 그 변화 과정에 관한 연구)

  • Cho, Junyoung;Lei, Qingyun;Yang, Naewon
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.26 no.4
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    • pp.39-47
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    • 2020
  • Purpose: Korea, China, and Japan can be seen as a geopolitical community that has developed through various relationships in terms of history. However, nowadays, it seems that they are pursuing different societal goals resulting from the difference in political and social systems, demographic structures, and economic situations. The law provides the minimum standards for people's lives in the direction that the society pursues. Therefore, the aim of this study is to examine the architectural differences in medical facilities and their causes comparing the legal standards of medical facilities in Korea, China, and Japan. Methods: The subject of the study is Korea, China, and Japan's legal standards of facilities corresponding to the Korean medical service act; enforcement decree of medical service act; and enforcement rules of medical service act. The scope of the study is as follows: First, the facilities standards and the reason for the revision of the standards after the 1950s when the current system of each country was established are investigated and thus the changing trends of the facilities standards that each country has pursued are analyzed. Second, the range and level presented by the current facilities standards of each country are compared and the differences are analyzed. Finally, cases in which the differences in the legal facilities standards are reflected in the actual design are compared and the effect of the facilities standards of medical facilities on the architectural plan is identified. Results & Implications: Each country differs in the legal standards of facilities because of changes in demographic structure and experience of disease. Moreover, it is identified that differences in social operating systems, especially in the operating methods of medical facilities, affect the range and level enforced by the facility standards. When investigating and researching foreign standards of facilities and cases for foreign medical facilities, it is required that they should be analyzed in consideration of the social and cultural aspects of each country.

Machine Learning-based Stroke Risk Prediction using Public Big Data (공공빅데이터를 활용한 기계학습 기반 뇌졸중 위험도 예측)

  • Jeong, Sunwoo;Lee, Minji;Yoo, Sunyong
    • Journal of Advanced Navigation Technology
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    • v.25 no.1
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    • pp.96-101
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    • 2021
  • This paper presents a machine learning model that predicts stroke risks in atrial fibrillation patients using public big data. As the training data, 68 independent variables including demographic, medical history, health examination were collected from the Korean National Health Insurance Service. To predict stroke incidence in patients with atrial fibrillation, we applied deep neural network. We firstly verify the performance of conventional statistical models (CHADS2, CHA2DS2-VASc). Then we compared proposed model with the statistical models for various hyperparameters. Accuracy and area under the receiver operating characteristic (AUROC) were mainly used as indicators for performance evaluation. As a result, the model using batch normalization showed the highest performance, which recorded better performance than the statistical model.

A Study for Development Scheme of National Qualification Korea: About the Apprenticeship Qualifications System and In-Firm Qualifications System (국가자격 법령 및 운영 개선방안에 관한 연구: 일학습병행자격제도와 사업내자격제도를 중심으로)

  • Jaehyeon, Park;Sunghee, Choi;Youngdeuk, Jung;Hwabong, Yuk
    • Journal of the Korea Safety Management & Science
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    • v.24 no.4
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    • pp.157-173
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    • 2022
  • In South Korea, the history of the qualifications has been matured with industry development. Since National Technical Qualifications Act was enacted in 1973, the government makes an effort to develop the ability for improving socioeconomic status and the contribution of qualifications to industry. As the industry has been diversified and globalized, the government has efficiently and systematically operating the qualification by enacting Framework Act on Qualifications in 1997. And then, the qualifications are classified into national qualifications, private qualifications, and foreign qualifications. However, it is hard for national qualifications to abolish or establish a qualification by each organization and the privileged license acquisitors as the qualifications are separately operated by the laws and the organizations and lack consistency. For private qualifications, it is harder to organize even by the government because of the entry barriers by each qualification association. For those reasons, it is necessary to organize the system adapted in the changing job market and operated by the organization managing the qualification system with consistency. This research indicates the inefficiency of the qualification system because the work-study parallelism National qualification system, enacted in 2020, is like the qualification system in business in terms of the general operating system and the operator, except the institute and the law related. Therefore, we analyze the work-study parallelism National qualification system and the qualification system in business and suggest the efficient method to operate and the future research plan regarding the whole qualification system.

A Study of Huh-Im(許任)'s ChimGuKyungHumBang(『鍼灸經驗方』) (허임(許任) 『鍼灸經驗方』 연구(硏究))

  • Park, Mun-Hyun
    • The Journal of Korean Medical History
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    • v.15 no.1
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    • pp.63-146
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    • 2002
  • Huh-Im(許任, 1570~1647) was an acupuncture doctor of Chosun(朝鮮) era through the late 16th century and early 17th century. Even though he was a person of low birth, he participated in the loyal medication through three loyal generations, Sunjo(宣祖), Kwanghaegun(光海君) and Injo(仁祖). He was recognized of his services and became an official, 'Dangsanggwan'(堂上官) and Kyunggi(京畿) district official several times. In the early Chosun era, acupuncture medicine was focused. During the late 16th century, Imjin(壬辰) war aroused more needs about acupuncture medicine, and acupuncture doctors showed remarkable work. Under these circumstances, Huh-Im(許任)'s fame spread throughout the country. Huh-Im(許任) wrote ChimGuKyungHumBang("鍼灸經驗方") in 1644 based on his lifetime clinical acupuncture & moxibustion experience. It was the first specialized book of acupuncture in Chosun era. This event took place 30 years after DongEuiBoGam - Acupuncture Chapter("東醫寶鑑-鍼灸篇") was published. But it was not influenced much by DongEuiBoGam - Acupuncture Chapter("東醫寶 鑑-鍼灸篇") in the form or contents. ChimGuKyungHumBang("鍼灸經驗方") and Huh-Jun(許浚)'s DongEuiBo- Gam - Acupuncture Chapter("東醫寶鑑-鍼灸篇") were the fruits of the middle Chosun, and they are complementary to each other in theory and practice. The chief distinctions of ChimGuKyungHumBang("鍼灸經驗方") are in it's compact and practical edition and a lot of his clinical acupuncture prescriptions mentioned in the book. Huh-Im(許任) not only accepted the existing books such as NaeKyung("內經"), DongInSuHyulChimGuDoKyung and Shin- Eung Kyung("神應經") with his point of view and clinical experience, but also showed creative operation of studies. Indicating incorrect acupuncture points(訛穴), acupuncture remedy based on the visceral pathogenesis(臟腑病機) and the channel pathogenesis, research on new acupuncture points, sorting out plenty of outer meridian acupuncture points(經外奇穴), creating supplementary and purging acupuncture method(鍼補瀉法) which is a change of hand treatment of KiHyoYangBang("奇效良方"), operating variety of acupuncture and moxibustion treatments, and application of acupuncture treatments on surgery field such as intumescences and emergency cases are the examples. Huh-Im(許任)'s ChimGuKyungHumBang("鍼灸經驗方") influenced on the folk remedy books(民間經驗方書) in the late Chosun era. Compact and practical characteristics of the book let acupuncture treatment be freindly to the people. It can be confirmed in JeungBoSanRimKyungJe-Emergency Chapter("增補山林經濟-救急篇") or the formation of SaAmChimBob(舍巖鍼法). ChimGuKyungHumBang("鍼灸經驗方") was introduced to Japan in 18th century and published twice. ChimGuJibSung("鍼灸集成"), known as an acupuncture medical book of late Qing dynasty(淸末, 1874), is confirmed to be an plagiarization of DongEuiBoGam-Acupuncture Chapter("東醫寶鑑-鍼灸篇") and ChimGuKyungHum- Bang("鍼灸經驗方") of 17th century Chosun. Confusions and errors arouse from mistaken editional trend of ChimGuJIbSung("鍼灸集成") which had not disclosed it's original author and the title of the book must be reformed. In this way, fruits of acupuncture of the middle Chosun era including Huh-Im(許任)'s ChimGuKyungHumBang("鍼灸經驗方") will take a right place in acupuncture medicine history.

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A Study of the Curriculum Operating Model and Standard Courses for Library & Information Science in Korea (한국문헌정보학 교과과정 운영모형 및 표준교과목 개발에 관한 연구)

  • Noh, Young-Hee;Ahn, in-Ja;Choi, Sang-Ki
    • Journal of the Korean Society for Library and Information Science
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    • v.46 no.2
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    • pp.55-82
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    • 2012
  • This study seeks to develop a curriculum operating model for Korean Library and Information Science, based on investigations into LIS curricula at home and abroad. Standard courses that can be applied to this model were also proposed. This study comprehensively analyzed the contents of domestic and foreign curricula and surveyed current librarians in all types of library fields. As a result, this study proposed required courses, core courses, and elective courses. Six required LIS courses are: Introduction to Library and Information Science, Information Organization, Information Services, Library and Information Center Management, Information Retrieval, and Field Work. Six core LIS courses are: Classification & Cataloging Practice, Subject Information Resources, Collection Development, Digital Library, Introduction to Bibliography, and Introduction to Archive Management. Twenty selective LIS courses include: the General Library and Information Science area (Cultural History of Information, Information Society and Library, Library and Copyright, Research Methods in Library and Information Science), the Information Organization area (Metadata Fundamentals, KORMARC Practice), the Information Services area (Information Literacy Instruction, Reading Guidance, Information User Study), the Library and Information Center Management area (Library Management, including management for different kinds of libraries, Library Information Cooperator, Library Marketing, Non-book Material and Multimedia Management (Contents Management), the Information Science area (Database Management, including Web DB Management, Indexing and Abstracting, Introduction to Information Science, Understanding Information Science, Automated System of Library, Library Information Network), and the Archival Science area (Preservation Management).

An Analysis of Transmitted-Vibration Characteristics by Different Wrist Posture during Grinding Tasks (그라인딩 작업시 손목자세별 국소진동 전달특성 분석)

  • Hwang, Seong-Hwan;Lee, Dong-Choon
    • Journal of the Ergonomics Society of Korea
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    • v.26 no.1
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    • pp.29-37
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    • 2007
  • This study was performed to evaluate the characteristics of transmitted vibration to hand-arm system under different work posture while operating a light-weighted powered hand grinder. For the experiment, 8 different types of wrist posture (natural, unlar-flexion, radual-flexion, flexion, extension, complex posture, and etc.) and 3 types of feed force (20[N], 50[N], 70[N]) were considered. 10 male subjects were employed to polish metal plate with a hand grinder. All of them were normal and healthy with no history and symptom of the work related musculoskeletal disorders in the dominant hand. Vibration acceleration data were recorded with sampling rate, 2048[Hz]. In addition, unweighted overall R.M.S. acceleration at the tool and wrist, and transmissibility between them were used to evaluate factors from the recorded tri-axial vibration acceleration. The results indicate that transmissibility of natural wrist posture was significantly higher than others. In addition, as the feed force becomes larger, the vibration was transmitted in large quantities to hand-arm system through radius.

A Plan of Efficient Images Display Using Shared Memory (공유메모리를 이용한 효율적인 감시 영상 표출 방안)

  • Lee, Won-Jae;An, Tae-Ki;Shin, Jeong-Ryol
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.3306-3311
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    • 2011
  • Last Subway video surveillance system consists of a network device that is used. Through the network to transmit video data to digital conversion of analog video via a process server or a PC video to a split-screen in various forms is expressed. In recent years, multi-monitor video cameras from the same pop-up or more, such as history, structure expressed on a variety of video is required by express. The problem with these systems, video compression and transmission of many cameras, and this image data received from the server or PC to take out all the images you want to watch to occur when in order to express all of the images because of the need to decode most of the program per limit of number of channels is positioned. This limited number of channels to have a video that nothing forced, but it is likely to do so in the future performance of the hardware evolves gradually channeled images available number of channels will increase proportionately. However, as the development of hardware required for a single screen video channel will be more gradual capital. The hardware rather than relying solely on the performance of the decoded video data on the screen in order to express a more efficient utilization of shared memory for video surveillance software will provide the operating plan.

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