• Title/Summary/Keyword: Scientific Maintenance

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

  • An, Cheon-Heon;Lee, Do-Sun;Son, Young-Jin;Lee, Hi-Sung
    • Journal of the Korean Society for Railway
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    • v.13 no.1
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    • pp.58-64
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    • 2010
  • As a modem urban train is getting complex in terms of high-technology in its systems and components, the failure management should be performed with scientific and systematic technique. FMEA is a technique to analyze the failure trends of component parts and influences to the higher level system in order to discover the design incompleteness and potential defects, which is for improving reliability. Especially, FMECA (Failure Mode Effects, and Criticality Analysis) is used in case that the criticality that has an immense influence to the system is important. In case of urban train, in its design and manufacturing steps, FMEA is frequently used as an analysis technique to meet the safety objectives and eliminate potential hazards/failures since the concepts of reliability of train is introduced these days. Though, FMEA technique in the maintenances steps lacks in its investigation and applications yet. FMEA is also not applied to the trains operated by Seoul metro in the design and manufacture steps excepts the newest trains. In this paper, through analyzing the failures/maintenance data of the belt-type door systems used in trains operated in Seoul metro Line 1, which is accumulated in RIMS (Rolling-stock Information Maintenance System), FMEA procedures to the belt-type door engines are proposed. Especially, an effort is made, to approach the detailed FMECA procedures to the door magnet valve and switch and door engine devices which vastly influences the customer safety and satisfaction.

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

  • Seo, Dong-Ju;Kim, Ga-Ya
    • Journal of the Korean Association of Geographic Information Studies
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    • v.11 no.4
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    • pp.139-149
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    • 2008
  • A load effect by vehicles running on a road and an increase of traffic is distinguished as a serious issue in the level of bridges' maintenance and management since it causes a quick damage of bridges. The expansion joint is the most important since it makes vehicles' traveling amicable and stress or additional load harmful to molding patterns minimized. However, it is very difficult to measure its expansion length since vehicles continue to pass on the expansion joint. Therefore, the study could see that it was possible to carry out a qualitative and quantitative maintenance and management if its expansion length is extracted with images. The study could acquire three dimensional coordinates of expansion joints with images. As the results of calculating RMSE of check point residual at 32 points in A area and at 28 points in B area, both A and B areas had very good results of RMSEsms 0.829mm~1.680mm. As the results of analyzing expansion length and immediate value extracted by images, the study analyzed that RMSE of A area was 0.64mm and RMSE of B area was 0.28. The average residual of A area was 0.60% and the average rresidual of B area was 0.27%. Therefore, it is judged that it is more scientific and efficient than the past to measure expansion length with images at the time of repairing and managing bridges in the future.

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

  • Kim, Jihyun
    • Journal of Korean Society of Archives and Records Management
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    • v.11 no.1
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    • pp.139-159
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    • 2011
  • This study investigated the perceived significance of laboratory(lab) notebooks and the creation and maintenance of them from the perspectives of graduate students and professors in science fields. Semi-structured interviews of three professors and four graduate students were conducted. The interviewees were from three university laboratories of physics, chemistry and biological science. While professors perceived administrative continuity to be a reason for creating lab notebooks, students valued lab notebooks as a memory, and emphasized learning professional knowledge and skills through the recordkeeping practice. Students understood the ownership of lab notebooks and professors wanted to keep lab notebooks until they retire. Interviewees focused more on the content of lab notebooks rather than the form and the structure. They were also not willing to adopt an electronic lab notebook system. Students learned how to create lab notebooks through a course, their current or former academic advisors, seniors in the lab or well-written sample lab notebooks. In particular, students have learned how to create lab notebooks within their laboratories, which are considered to be communities of practice. In this sense, professors responsible for managing laboratories play an important part in teaching students the recordkeeping practice. University archives should also be more concerned with managing and preserving lab notebooks created from their universities.

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

  • Kim, Eun-Ja;Ahn, Sam-Young;Kim, Young;Rhee, Sang-Young;Lee, Jeung-Won
    • Journal of Agricultural Extension & Community Development
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    • v.16 no.4
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    • pp.869-912
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    • 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.

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

  • MOON, Sungchae
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.5
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    • pp.1236-1251
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    • 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
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    • v.17 no.4
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    • pp.348-352
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    • 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.

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

  • 유정곤;이승우;황진욱
    • The Journal of Fisheries Business Administration
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    • v.29 no.2
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    • pp.177-197
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    • 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.

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

  • Lee, Sun-Dong;Choi, Chan-Ho
    • The Journal of Korean Medical History
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    • v.24 no.1
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    • pp.9-15
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    • 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
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    • v.6 no.4
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    • pp.333-340
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    • 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.

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

  • Choi, Jae-Myeong;Woo, Byung-Hoon;Kang, Heau-Jo
    • Journal of Advanced Navigation Technology
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    • v.18 no.5
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    • pp.518-523
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    • 2014
  • The development of Societal and Scientific technologies have increased risk of dysfunction caused by new technologies such as nuclear power, information technology. Also, urbanization and population density is increasing risk to high-rise building fires, traffic accidents, crime and etc. Implementation of wireless communication network on the societal security is very necessary for prevention, preparation and response against these risks. It always consists maintenance, management and the network must be maintained in an emergency. In this paper, we studied the societal security wireless communication network for prevention, preparation and response against complex disasters, and analyzed requirements(essential function, add-ons) for implementation network in the societal security wireless network.