• 제목/요약/키워드: Scientific Maintenance

검색결과 142건 처리시간 0.026초

FMECA 적용을 통한 벨트식 도어시스템 신뢰성 향상에 관한 연구 (A Study for Reliability Improvement of Belt Type Door System using FMECA)

  • 안천헌;이도선;손영진;이희성
    • 한국철도학회논문집
    • /
    • 제13권1호
    • /
    • pp.58-64
    • /
    • 2010
  • 현대의 도시철도차량은 부품과 시스템이 복잡하고 첨단화되어 고장관리 또한 과학적이고 체계적인 접근이 반드시 수행되어야 한다. 고장모드 및 영향분석(FMEA)은 설계의 불완전성이나 사용 중에 일어날 수 있는 잠재적 결함을 알아내기 위해 구성요소의 고장 형태와 그 상위 시스템에 미치는 영향을 분석하는 기법으로 개선대책을 수립하여 신뢰도를 향상시키는 목적이며, 특히, 시스템에 큰 영향을 미치는 치명도를 중시하는 경우는 고장모드 및 영향, 치명도 분석(FMECA)이라는 기법을 사용한다. 철도차량의 경우 FMEA는 최근 차량시스템에 대한 신뢰성 개념을 도입하면서부터 설계 및 제작단계에서 발생 가능한 위험요인과 고장을 제거하기 위한 분석기법으로 활발히 활용되어 왔으나, 철도차량의 유지보수에 있어서 FMEA 기법은 연구 및 활용이 미미한 실정이다. 서울메트로에서 운영 중인 차량도 최근 도입된 신조차를 제외하고는 설계 및 생산단계의 FMEA가 수행되지 못하였다. 이에 본 논문은 1호선에서 운용되는 차량의 주요 장치인 벨트식 출입문에 대하여 서울메트로에서 운영 중인 차량분야 정보화시스템(RIMS)에 축적된 고장 및 유지보수데이터를 분석하여 FMECA 절차에 따른 적용방안을 제시하고자 하였으며, 특히, 고장 시 고객들의 안전과 만족도에 직접적인 영향을 미치는 출입문전자변과 도어연동 스위치, 도어엔진 장치에 대한 FMECA 관련 세부적 사항까지 접근하고자 하였다.

영상을 이용한 교량 신축이음부의 신축량 추출 (Extraction of Expansion Length for Expansion Jiont Bridge using Imagery)

  • 서동주;김가야
    • 한국지리정보학회지
    • /
    • 제11권4호
    • /
    • pp.139-149
    • /
    • 2008
  • 도로를 통과하는 차량하중 및 통행량의 증가로 인해 발생하는 하중효과는 교량에 급격한 손상을 유발시키기 때문에 교량의 유지관리차원에서 심각한 문제로 대두되고 있다. 그중 신축이음부는 차량의 주행을 원활하게 해주면서 주형에 유해한 응력이나 부가 하중이 최소화되도록 해주는 것이 가장 중요한 부분이다. 그러나 신축이음부는 향시 차량이 지나감으로 신축량을 측정하기란 매우 어려운 실정이다. 따라서, 신축이음부를 영상을 이용하여 신축량을 추출하면 정량적이고, 정성적인 유지관리를 할 수 있음을 알 수 있었다. 영상을 이용하여 량신축이음부에 대한 3차원 좌표를 취득할 수 있었으며, A지역 32개소과 B지역 28개소에 있어서 검사점(Check Point)의 잔차에 대한 RMSE를 산정한 결과 A,B지역 모두 RMSE는 0.829mm~1.680mm의 매우 양호한 결과가 나타났다. 영상에 의해서 추출한 신축량과 실측값과 비교분석한 결과, A지역 RMSE는 0.64mm, B지역 RMSE는 0.28mm로 분석하였으며, A지역 평균잔차는 0.60%, B지역평균잔차는 0.27%로 나타났다. 또한, 향후 교량의 유지관리시 신축량을 측정은 영상을 이용하여 측정하므로서 과거에 비해 과학적이고, 효율적인 방법으로 판단된다.

  • PDF

자연과학분야 대학실험실에서의 연구노트 작성 및 관리에 관한 연구 (A Study on the Creation and Maintenance of Laboratory Notebooks in Scientific Laboratories of a University)

  • 김지현
    • 한국기록관리학회지
    • /
    • 제11권1호
    • /
    • pp.139-159
    • /
    • 2011
  • 본 연구는 대학 내 실험실에서 연구노트의 기록자인 학생들과 관리자인 교수들의 관점에서 연구노트의 중요성과 생산 및 관리의 측면을 조사하고자 하였다. 이를 위해 대학 내 물리, 화학, 생명과학 실험실의 교수 3명과 대학원생 4명을 대상으로 반구조화된 심층 면담을 실시하였다. 교수들은 연구 연속성을 연구노트 작성의 중요한 목적으로 인식한 반면 학생들은 기억으로서의 연구노트의 중요성과 이를 작성하는 과정을 통한 지식과 노하우의 학습을 강조하였다. 학생들은 연구노트가 연구실의 소유임을 분명히 인식하고 있었으며 교수들은 연구노트를 퇴임 시까지 실험실에 보관할 것이라고 언급하였다. 면담 참여자들은 연구노트의 형식적인 측면보다 내용적인 측면에 초점을 맞추고 있었으며 전자연구노트의 도입 필요성은 인식하지 못하고 있었다. 학생들은 정규 실험수업, 실험실 내 교수님과 선배, 견본 연구노트를 통해 연구노트 작성법을 습득하고 있었고 특히 실험실이라는 지식실행공동체 내에서의 학습이 큰 부분을 차지하고 있었다. 이는 연구노트 작성 교육에 있어 실험실의 총책임자인 교수의 역할이 중요하다는 것을 보여준다. 또한 대학 내 연구노트 작성과 관리에 있어 대학기록관의 역할이 보다 강조될 필요성이 있다.

초.중.고 과학교과서에 나타난 농업.농촌 다원적 기능 교육 내용 분석 (Content Analysis on Rural Multi-Functionality published in Science Textbooks of Elementary.Middle.High School)

  • 김은자;안삼영;김영;이상영;이정원
    • 농촌지도와개발
    • /
    • 제16권4호
    • /
    • pp.869-912
    • /
    • 2009
  • The objective of this study is to promote alternative plans on the prejudiced and distorted contents in school textbooks in the aspect of multi-functionality of agriculture and rural community. This was done through analysis of contents in 47 kinds of textbooks in science (8 of elementary school, 27 of middle school and 12 of high school). This will lead to promote understanding about the multi-functionality and form the proper value system related to agriculture and rural community for children and juveniles using textbooks. A content analysis was employed to examine to what extent the contents on agriculture and rural community were reflected in the textbooks for elementary school, middle school and high school. The content analysis was done in three categories, including presentation form, application method and function view. The followings are results of contents analysis in textbooks. The most frequently used presentation forms related to agriculture and rural community was figures and tables. In analysis of application methods, this research found that the contents related to agriculture and rural community were used to explain scientific facts and phenomena. In the function view, maintenance of local societies was most frequent among the various multi-functionalities in elementary and middle school, and food security in high school. Based on the results of content analysis, findings and recommendations in textbooks for elementary, middle and high school have been drawn, and several examples for contents development to be included in the textbooks were listed.

  • PDF

패널토론을 적용한 지속가능발전교육에서 대학생의 원자력발전소 건립에 대한 지속가능발전 인식과 태도 (Understanding and Attitude to Sustainable Development of College Students for a Nuclear Power Plant Construction in Education for Sustainable Development through Panel Discussion)

  • 문성채
    • 수산해양교육연구
    • /
    • 제27권5호
    • /
    • pp.1236-1251
    • /
    • 2015
  • This study examined understanding and attitude of sustainable development(SD) of 38 college students in a nuclear power plant construction after education for sustainable development(ESD) through panel discussion. The results were as follows: First, after lesson 66% of students were expected that SD is possible if scientific technology is developed and a frugal life for the protection of environment is carried out. However, the remaining students regarded SD as an ideal concept, because they thought it is not possible to pursue environmental sustainability and socio-economic development simultaneously. Second, students' opinions in the evaluation of constructing a nuclear power plant in three aspects(environment, society and economy) before and after panel discussion were changed as follows; 1) After panel discussion, the objectors increased to 21% in economic evaluation, while the supporters increased to 11% in environmental evaluation. 2) Students majoring in engineering or natural sciences changed their opinions to agree in environmental evaluation because they considered a nuclear power plant safe and eco-energy. However students majoring in social science/business or liberal arts/arts changed their opinions to disagree in economic evaluation because they considered a nuclear power plant as high-cost energy when assessing danger-accidents cost, public consensus cost, operation and maintenance cost, and waste disposal cost. 3) This change of decision-making in students majoring in social science/business or liberal arts/arts after panel discussion was statistically significant(p<0.05). Implications of panel discussion as a teaching and learning method in ESD are also discussed.

Pharmacological Therapies of Obesity: A Review of Current Treatment Options

  • Bacher, H.Peter;Shepherd, Gillian M.;Legler, Udo F.
    • Biomolecules & Therapeutics
    • /
    • 제17권4호
    • /
    • pp.348-352
    • /
    • 2009
  • Over the last decade, the incidence of overweight and obesity has nearly doubled in many countries and is considered a pandemic. Obesity was identified as a major risk factor for cardiovascular disease as the same level as smoking and diabetes. Visceral fat is considered one of the key contributors to outcome and certain ethnic groups such as Asians seem to be more affected than others. Weight reduction through lifestyle changes was found to be impactful to improve overall health, but weight loss and maintenance thereof is limited and difficult to sustain. Surgical intervention demonstrated a greater weight loss in the severely obese and was associated with improved all-cause mortality. Despite numerous pharmacological targets and a high medical need, only few drugs have been successfully developed. Earlier studies with amphetamine-derived compounds showed significant weight loss but their critical safety profiles led to market withdrawals and disappointment. More recent compounds; orlistat - a lipase inhibitor, rimonabant - a cannaboid-1-receptor antagonist, and sibutramine - a combined serotonin/norepinephrine re-uptake inhibitor, all demonstrated similar significant efficacy; however, they carry specific safety profiles making them unsuitable for every patient. The main limitation of pharmacotherapy is the absence of clear benefit-risk assessments through outcome studies. Such a study - the SCOUT trial - was designed to compare sibutramine versus placebo and the effect on morbidity and mortality in nearly 10,000 obese patients with additional risk factors. Such studies could provide new scientific evidence for obesity treatment and may support future pharmacological approaches.

인공어초시설사업의 경제적 효과에 관한 연구 -수우도 인공어초어장을 중심으로- (A Study on the Economic Effects of Artificial Reefs -In Case of Suwoo-do Artificial Reefs-)

  • 유정곤;이승우;황진욱
    • 수산경영론집
    • /
    • 제29권2호
    • /
    • pp.177-197
    • /
    • 1998
  • Korean fisheries industry is surrounding by domestic and international difficulties due to the effectuation of the UN Convention on the Law of the Sea and declaration by many coastal states of 200-mile Exclusive Economic Zone and acceleration of ocean pollution in global recognition increasing of the importance of the ocean Resource enhancement policy in Korea fisheries industry is very important strategy fer the fostering of the fisheries resource and proper conservation and management of the coastal and off-shore living marine. Among resource enhancement policy, artificial reefs project has been the most effective strategy. The objectives of this paper are to find the economic effects of artificial reefs. The sampling artificial reefs is constructed at Suiido with 6~7m height. In order to analyze the fishing effect of artificial reefs, a few research have been conducted since 1975. For these analysis focuses on the side of scientific effect of artificial reefs, we analyzed on the side of economic effect. The results of the economic effects of artificial reefs are as follows ; First, the fishing effect analysis by using the NPV method in artificial reefs of Suiido ground prove to be economic feasibility. Second, the major socio-economic effect from artificial reefs include the increasing of recreation fishing, maintenance of fishing community, protection illegal fishing, conservation of coastal environment, and enlargement of advanced fisheries supply. Based on the above results, we conclude that artificial reefs project not only contributes to the welfare of fishermen by increasing of economic income, but enlarges to socio-economic gains by protection of illegal fishing and conservation coastal environment and so on.

  • PDF

최근 한방의료기관의 환자감소요인 고찰 (Reasons for Decrease Number of Patients at Oriental Medical Clinic)

  • 이선동;최찬호
    • 한국의사학회지
    • /
    • 제24권1호
    • /
    • pp.9-15
    • /
    • 2011
  • Recently, the oriental medicine industry in Korea has faced much hardship, due to the decreasing number of patients. Therefore, it is essential to investigate the reasons why patients are avoiding oriental medicine, because the percentage of people consuming medical service is an important marker that assesses the value of medical service. The researcher(s), based on theories on factors that affect health, health behaviors, and diseases, sought to find reasons why oriental medicine clinics saw a decline in the number of patients. Also, by proposing the problems inside the oriental medicine, I came to the following conclusion. -Because Koreans have low expectations for oriental medicine, they do not consider it as full medical service. Also, when they get sick, they are reluctant to seek oriental medicine because of reasons such as the limits of oriental medicine and check-ups, expensive medical cost, negative perception of oriental medicine, not enough support from the media, the old image of the oriental medicine and the little power the industry has on the society. -Among the inner problems of the oriental medicine community was the limitations that the science face on incurable and chronic diseases in terms of treatment and management, little professionalism, lack of scientific evidence, the attitude of the oriental medicine society, lack of sophistication in research methodology, and limitations in responding to changes in public health and the surroundings. The purpose of medicine is to eliminate the possibility of shortened life and dangers by treatment of diseases and health maintenance. For this to happen, structural and developed medical theories and means of treatment are necessary. The researcher hypothesizes that the problems that the oriental medicine society is facing mainly come from the lack of efforts and ability to provide such necessities.

MEASUREMENT OF OPERATIONAL ACTIVITY FOR NONROAD DIESEL CONSTRUCTION EQUIPMENT

  • HUAI T.;SHAH S. D.;DURBIN T. D.;NORBECK J. M.
    • International Journal of Automotive Technology
    • /
    • 제6권4호
    • /
    • pp.333-340
    • /
    • 2005
  • In order to better quantify the contribution from nonroad sources to emission inventories, it is important to understand not only the emissions rates of these engines but also activity patterns that can be used to accurately portray their in-use operation. To date, however, very little information is available on the actual activity patterns of nonroad equipment. In this study, a total of 18 pieces of nonroad equipment were instrumented with collected data including intake manifold air pressure (MAP), exhaust temperature and, on a subset of vehicles, engine rpm and throttle position. The equipment included backhoes, compactors, dozers, motor graders, loaders and scrappers used in applications such as landfilling, street maintenance and general roadwork. The activity patterns varied considerably depending on the type of equipment and the application. Daily equipment operating time ranged from less than 30 minutes to more than 8 hours, with landfill equipment having the highest daily use. The number of engine starts per day ranged from 3-11 lover the fleet with an average of 5 starts per day. The average percent idle time for the fleet was approximately $25\%$ with a range from 11 to $65\%$ for individual pieces of equipment. Duty cycles based on exhaust temperature/throttle position profiles were also developed for two graders and one dozer.

스마트 사회안전무선통신망 요구사항 분석에 관한 연구 (A Study on Analysis of Requirements in the Smart Societal Security Wireless Network)

  • 최재명;우병훈;강희조
    • 한국항행학회논문지
    • /
    • 제18권5호
    • /
    • pp.518-523
    • /
    • 2014
  • 현대사회는 사회, 과학기술의 발달로 원자력, 정보화 등 신기술에 기인하는 역기능의 위험성이 증가하고, 재난 또한 과거에 없었던 새로운 위험들이 증가하면서 복합적인 재난으로 변화하였다. 이와 함께 도시화와 인구밀집은 고층건물화재, 교통사고, 범죄등의 위험도를 증가시키고 있다. 이렇게 다양한 위험요소로부터 예방 대비 대응하기 위하여 사회안전무선통신망의 구축은 절대적으로 필요하다. 사회안전무선통신망의 구축, 유지 및 관리가 항상 이루어져야하며 긴급한 상황에서도 통신망이 유지되도록 힘써야 한다. 본 논문에서는 복합재난으로부터 예방 및 대비, 대응하기 위한 사회안전무선통신망을 알아보고, 사회안전무선통신망을 분석하여 망 구현을 위한 필수기능, 부가기능 등의 요구사항을 연구하였다.