• Title/Summary/Keyword: Condition-base maintenance

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Development of Equipment Operating Condition Diagnosis Model Using the Fuzzy Inference (퍼지추론을 이용한 설비가동상태진단 모델 연구)

  • Jeong, Young-Deuk;Park, Ju-Sik
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.28 no.4
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    • pp.109-115
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    • 2005
  • In the study, Methods for operating measures in equipment security to find out dangerousness timely in the system and to need for the prevention and measures. The method for analyzing and reconstructing the causes of accident of equipment in site, and try to save the information of site in real-time and to analyze the state of equipment to look for the factors of accidents. By this analysis, one plan for efficiency of production, Equipment Fault Diagnosis Management and security is integrating and building module of using the Fuzzy Inference based on fuzzy theory. The case study is applied to the industrial electric motors that are necessarily used to all manufacturing equipment. Using the sensor for temperature is attached to gain the site information in real time and to design the hardware module for signal processing. In software, realize the system supervising and automatically saving to management data base by the algorithm based in fuzzy theory from the existing manual input system

The Study on Evaluation Basis of Management Strategy in Public Buildings (공공건축물의 합리적인 운영평가기준 설정 방향에 관한 연구)

  • Lee, Sang-Beom;Noh, Byung-Ok
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.2
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    • pp.69-76
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    • 2009
  • Recently, the twenty-first century is called "the age of localization and regionalization" in Korea. So, local government should need to keep balance between the existing administrative management and new management strategies based on CEO's mind in order to deal with the situation of such that(the age of localization and regionalization) and improve efficiency of public service. In addition, they build public buildings after that they should operate and maintain them regularly. However, Korea local governments have tried to run many projects to expand insufficient local finance that was only for profit oriented public projects without considering management. Therefore, this paper is a basic study to establish and suggest the reasonable operation plan for local government by examining and reviewing actual operation condition in the public buildings. With the evaluation method which is demanded from public construction management to introduce a civil management technique manages an investment mind standard and management basis of assessment, proposes 8 sides of financial affairs, real estate maintenance and facility management, achievement evaluation, environmental safe crisis management, judiciary and explanation responsibility with base.

A Study on the Preventive Measures against Fall Injuries in Manufacturing Industry Focusing on the Portable Ladders (이동식 사다리를 중심으로 한 제조업에서의 추락재해 예방대책 연구)

  • Kim, Hyung-Seok;Lee, Seok-Won;Jung, Won-Jae;Ryu, Bo-Hyuk
    • Journal of the Korean Society of Safety
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    • v.24 no.6
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    • pp.136-143
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    • 2009
  • The injuries as a result of fall accidents is the one of the most common kind of injuries in Korea, especially fall from height is the top most common kind for fatal injuries. Futhermore, the number of fall injuries in manufacturing industry has been steadily increasing from 2000 to 2007. In 2007 the number of fall fatal injuries increased 10.6 % in comparison with the number in 2006. These numbers are 6~17 times higher than those for foreign countries such as the U.K and the USA. So, it is needed to make a study to reduce these numbers for manufacturing industry. To get the goals, we did research as followings. First, this study analyzed statistics by industry, by fall height, by common agent and so on to gain an insight into real aspect of fall injuries. It showed that ladder is the commonly cited agent for manufacturing industry, and 3 risky activities ; the ladder work, the load/unload work, and the maintenance work. Secondly, this study made a survey of manufacturing workers for their understandings of the most 3 risky activities. It showed that 'tendency to work easily' and 'difficulty of applying measures due to inherent working conditions' are main reasons for workers not to implement the preventive measures against the fall accidents. Thirdly, this study tested the slip characteristics of ladder base and lungs. The tests were done based on ANSI standard and KS. In addition to the standard condition, this study performed slip tests in wet and sandy conditions and compared the results with the those of standard condition. It showed that friction coefficient is standard condition > wet condition > sandy condition, and the friction coefficient of ladder for sandy condition is measured to be reduced by 63.9% compared with that for standard condition. Finally, this study developed safety work models for using of portable ladders in consideration of the safety standards of foreign countries such as the U.K, the USA, and the Australia.

GE 7FA+e DLN-2.6 Gas Turbine Combustor : Part Ⅰ Operating Condition Optimization (GE 7FA+e DLN-2.6 가스터빈 연소기 연구 : Part Ⅰ 운전조건 최적화)

  • Oh, Jeong-Seog;Kim, Min-Ki;Heo, Pil-Won;Lee, Jang-Soo;Yoon, Young-Bin
    • Journal of the Korean Society of Propulsion Engineers
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    • v.12 no.5
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    • pp.43-50
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    • 2008
  • DLN-2.6 combustion tuning was carried out for the maintenance of GE 7FA+e gas turbine at Seo-Incheon combined cycle power plant. DLN-2.6 combustion system has the higher level of yellow plume and combustion vibration problem in the initial operating mode than that of the base mode($100{\sim}160MW$). The objectives of this study are to investigate the causes of yellow plume and combustion vibration problems at the starting mode and to suggest the best operating condition for the reliable working of the real combustors. By the analysis of tuning data, we could conclude that a yellow plume is caused by the rich mixture(${\phi}{\sim}1$) in a PM 1 nozzle at mode 3($20{\sim}30MW$). In addition, the combustion vibration($120{\sim}140Hz$) might be related to the cold flow characteristics of PM 3 nozzles at mode 6B($40{\sim}45MW$).

Preliminary Investigation into the Use of Methyl Methacrylate(MMA)-Based Materials for Road Repair (메틸 메타크릴레이트 기반 도로 보수재 개발을 위한 기초 연구)

  • Ji, Sung-Jun;Pyeon, Su-Jeong;Choi, Byung-Cheol;Kim, Jae-Hwan;Kim, Do-Su;Nam, Jeong-Soo
    • Journal of the Korea Institute of Building Construction
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    • v.24 no.1
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    • pp.35-42
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    • 2024
  • This research explores the potential of methyl methacrylate(MMA) as a material for road repair applications. It specifically examines two MMA formulations, referred to as type A and type B, in relation to their performance on concrete substrates. The evaluation criteria included drying time, tensile bond strength, and resistance to alkali. The condition of the substrate surface was varied across three curing environments: constant temperature and humidity(R), immersion in water(W), and immersion in water with chloride ions(N). The findings indicate that type B MMA exhibits a quicker drying time and superior resistance to alkali compared to type A. While type A demonstrated greater tensile bond strength, it failed to maintain adhesion with the concrete base. Based on the parameters tested in this study, type B MMA emerges as the more favorable option for road repair contexts. Nonetheless, the study underscores the necessity for additional testing on asphalt substrates to fully assess the material's durability and applicability for long-term road maintenance.

Durability and Bioassay of a Sulfur Polymer Surface Protecting Agent for Concrete Structures (콘크리트 구조물용 유황폴리머 표면보호재의 내구성능 및 생물독성)

  • Seok, Byoung-Yoon;Lee, Byung-Jae;Kim, Yun-Yong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.19 no.6
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    • pp.29-36
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    • 2015
  • In this study, to examine the use of sulfur polymer as a coating agent for concrete, durability and hazard evaluations were performed. The result of the evaluation indicated that the chemical resistance of the coating agent for concrete was outstanding against acidic, base, and alkaline solutions. The evaluation of the bond strength after an accelerated weathering test depending on the mixing condition indicated that the most outstanding strength characteristic was obtained when silica powder and fly ash were mixed at the same time. The bond strength exceeded 1 MPa in every mixing condition even after the repeated hot and cold treatment of the coating agent specimen for concrete, and the SFS mix proportion showed the highest bond strength. The examination of the accelerated carbonation and chloride ion penetration resistance of the concrete coated with the coating agent indicated that the specimen coated with the coating agent using silica powder as a filler showed the most outstanding durability. When a fish toxicity test was performed to examine the hazard of the use of the functional polymer as a coating agent for concrete, the functional polymer was found to have no effect on the organisms. When the chemical resistance, freezing and thawing resistance, carbonation, and chloride ion penetration resistance of the coating agent were considered, substituting silica powder and fly ash as the fillers of the functional polymer by 20%, respectively, was the optimal level in the range of this study.

Determination of Base Capacity Values for Short-Term Freeway Work Zone (고속도로 단기공사구간 기본용량 결정에 관한 연구)

  • Kim, Sang Gu;Hong, Gil Seong
    • Journal of Korean Society of Transportation
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    • v.31 no.1
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    • pp.37-46
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    • 2013
  • Lane closure in freeway work zone due to maintenance and repair of freeway facilities results in abrupt change of traffic flow. Sudden change of traffic flow results strong interactions among vehicles, and reduces capacity compared to the ordinary traffic condition. Such capacity reduction is likely to cause congestion, traffic queues, and economic loss cost. This study aims to determine the base capacity for a short-term freeway work zone that can be used to establish a work zone schedule in advance without any traffic impact. First, the research collected detector data and schedule data of road works on all freeways in Korea. Second, the research determined 23 study sites finding the capacity values of work zone after matching two kinds of data. All study sites had varying characteristics regarding traffic flow being adjacent to work zone during road works. The capacity values were reviewed in terms of lane closure configuration, the types of work, and design speed. Finally, research proposed capacity values for a short-term freeway work zone with the design speeds of 100 kph, 120 kph and 1,700 pcphpl, 1,750 pcphpl, respectively.

A Study on the Export Competitiveness of Korea IT Industry to China (한국 IT산업의 대중국 수출경쟁력 분석에 관한 연구)

  • Jeong, Boon-Do;Yun, Bong-Ju
    • International Commerce and Information Review
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    • v.11 no.4
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    • pp.111-128
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    • 2009
  • As it is expected that change in trade environment has a significant impact on Korean economic growth as well as foreign trade of Korean economy we need an appropriate political response to it. Therefore, this study aims to analyse the Export Competitiveness of IT Industry to China and our trade policy. Korean balance of trade to China in 2007 records surplus of 18.9 billion dollars. However, many experts estimate unfavorable balance of trade will appear from 2010. In consideration of this condition, this study suggests a desirable trade policy for long-term maintenance of current Export Competitiveness between Korea and China. Using TSI and RCA, it analyses a Export Competitiveness of IT Industry to China from 2003 to 2007. To sum up the results, the TSI has been declining since 2005. RCA of semi-conductors has been declining since 2005 while that of communication equipment and computers has been increasing. During the analysis period, the mean RCA of semi-conductors is 55.01, which indicates that its export advantage is somewhat weak, and the mean RCA of communication equipment and computers are 227.22 and 175.83 respectively, which indicates that their export advantage is very strong. Production and export of Korea IT industry have greatly increased in quantity, but its technological quality and diversity have not been satisfactory. In particular, the base of IT industry is growing weaker due to serious dependence of core spare parts on advanced countries and transfer of simple assembly plants to China. To maintain export competitiveness of IT industry, we should pay more attention to technological improvement through more investment to the original technology for local production of core spare parts.

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An Analysis of Social Carrying Capacity in Natural Park (자연공원의 사회적 수용능력 분석 - 국립공원과 도립공원을 대상으로 -)

  • 배민기;장병문
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.6
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    • pp.79-97
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    • 2003
  • The purpose of this paper is to analyze a causal model determining social carrying capacity(SCC) in natural parks, to answer the research question: What is the mechanism for determining SCC in natural parks (NP)\ulcorner After reviewing the literature on SCC and recreation activities in Korean natural parks, we constructed a conceptual framework and formulated the hypothesis of this research. We obtained data through a questionnaire which surveyed 487 visitors at 6 of the 73 NP in Korea during 2001, based on a stratified sampling method. We analyzed the data using descriptive statistical methods, the mean difference test, Pearson's correlation analysis, and path analysis method. We found that 1) The direct effect of resources, activity space(AS), visitor's expectation(VE), encounter, crowding, damage of resources(DR), maintenance condition of resources and facility(MCRF) to SCC are 3.45, 3.62, 2.75, 2.72, 1.32, and 4.77 times more important than that of crowding, respectively, while the indirect effect of resources, AS, VE, encounter, and DR to SCC is 13.03, 11.19, 3.34, 1.3, 2.05, 1.10, 0.05 and 2.30 times more important then that of crowding, respectively, 2) Causal effects of resources, facility, AS, VE, number of visitors(NV), encounter, crowding, VM, DR, and MCRF to SCC turned out to have 0.3523, 0.3321, 0.1751, 0.1465, 0.0307, 0.0762, 0.0604, -0.0510, -0.1177 and 0.2165, respectively, and 3) The causal effect of activity base(AB) and activity atmosphere(AA) to SCC turned out to have 2.57 and 1.1 times higher than that of MCRF, respectively. The research results suggest that 1) this conceptual framework is highly useful for the development of substantive theory and methodology; 2) management issues of AA and MCRF turned out to have 0.81 times in SCC that of AB, i.e, SCC can be significantly improved from control of AA and MCRF; and 3) supply of excellent resources and convenient facilities is needed to increase social carrying capacity. It is recommended that more empirical studies be performed in the future according to the season, visitor characteristics, and AS by NP.

System Design and Application of External Feature Extraction for Quality Maintenance of Yukwa (유과의 품질규격 유지를 위한 외형 정보 측정 시스템 설계 및 적용 연구)

  • Cho, Sung Ho;Kim, Tae Jung;Hwang, Heon
    • The Korean Journal of Community Living Science
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    • v.24 no.2
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    • pp.251-258
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    • 2013
  • Korean oil and honey Yukwa has been paid attention as formal cake for traditional national seasons' holiday and religious service. Quality of Yukwa, however, has been maintained arbitrarily by each Yukwa manufacturer. Since even same Yukwa had severe differences in size, weight, and pattern, it has given the negative effect to the consumer. Yukwa industries need to setup the quantitative quality specifications instead of qualitative ones to maintain the uniformity of Yukwa quality. Efficient and economical inspection and process control system should be developed. In developing quality standards of Yukwa, features which can measure quality quantitatively in real time should be properly chosen. Existing quality features such as acidity, oxidization, hardness, viscosity, and texture were measured by the chemical or physical base destructive methods. Many research and developments have been performed in investigating and analyzing chemical transition states of those quality features as environment or storage condition changes. Most methods, however, require either off-line or complex treatment or time consuming process of analysis in evaluating quality features. Consumer, however, selects products mostly based on the external features such as shape, size, and color. Therefore, critical visual quality features should be chosen and the efficient real time measurement system must be developed. In this paper, computer image acquisition and processing system were developed and software modules were developed to extract the quantitative data of those features in real-time. Computer image processing system will promote in maintaining uniform quality of Yukwa and establishing quality standards of Yukwa.