• Title/Summary/Keyword: economic cycle

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Development of Maintenance Information System for Electric Multiple Unit (도시철도 차량 유지보수 정보화시스템 개발)

  • Park, Kee-Jun;Kim, Moon-Hyun;Ahn, Tae-Ki
    • Journal of the Korean Society for Railway
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    • v.9 no.5 s.36
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    • pp.577-581
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    • 2006
  • Urban transit operation corporations perform repetitive work to investigate the EMU, electric multiple unit, by some fixed maintenance cycle. The quality of maintenance work usually depends on workers' know-how. Though some information to support the maintenance work is digitalized and provided to workers, it is not great help to them because of its non systematic structure. The information includes drawings, manuals, work results, work history, fault history, etc. The maintenance workers want to access the information anytime anywhere, and make an effect to promote the efficiency of maintenance for EMU. But it is difficult to achieve that without some structured information system which is able to use in work area. So we develop maintenance information system for EMU for about 4 years from 2002 to 2005. In this paper we present the configuration and characteristics of this system, and the results of the evaluation test. We install the system in two depots, Changdong and Jichuk, belonged to SeoulMetro to evaluate its efficiency and estimate its economic benefits.

A Study of the Quality Costs in Manufacturing Systems (제조시스템에서의 품질비용에 관한 연구)

  • Chang, Seog-Ju;Lee, Sung-Woong;Park, Young-Hyun
    • Journal of Korean Society for Quality Management
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    • v.23 no.2
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    • pp.10-27
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    • 1995
  • This paper illustrates a method of developing a function of quality costs in manufacturing systems. It begins with a discussion of the problem statement of this research. A review of existing literatures related to quality costs and economic design of quality inspection methods are discussed. Next mathematical models that quantify the production cycle time and quality costs are formulated. This paper ends with an example that demonstrates the usefulness of the model and highlights the importance of using a system approach. The main contribution of this work is the more realistic considerations of the four types of quality costs (prevention cost, appraisal cost, internal failure cost, external failure cost) in manufacturing systems.

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A Study on Development of Pavement Management System for Cement Concrete Pavement (시멘트콘크리트포장의 유지관리체계(PMS)에 관한 연구)

  • 엄주용;김남호;임승욱
    • Proceedings of the Korea Concrete Institute Conference
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    • 1996.04a
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    • pp.363-369
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    • 1996
  • PMS(Pavement Management System) is the effective and efficient decision making system to provide pavements in an acceptable condition at the lowest life-cycle cost. As the highway system become larger, the necessity of the PMS in increasing. As of December 1995, the 3rd stage of PMS project was completed. The accomplishment of the research work can be itemized to the followings : $\bullet$ Calibration of PMS submodules (1) Pavement Condition Evaluation Model (2) Pavement Distress Prediction Model (3) Pavement Performance Prediction Mode (4) Selection of Pavement Rehabilitation Criteria (5) Optimization Technique for PMS Economic Analysis $\bullet$ Development of Computer Program to Implement PMS Logic $\bullet$ A Study to Implement the Automized Pavement Condition Survey Equipment to PMS $\bullet$ PMS Test Run $\bullet$ Development of PMS Operation Guideline $\bullet$ The 2nd Pavement Condition Survey for Long-Term Pavement Performance Monitoring.

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A Post Occupancy Evaluation by the Rental Apartment tenants of National housing Size (국민주택규모 임대아파트 임차자의 거주 후 평가)

  • Lee, Sang-Un;Park, Kyoung-Ok
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2003.11a
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    • pp.289-294
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    • 2003
  • Purpose of this study is to supply data that need in qualitative improvement and plan for middle class through a post occupancy evaluation by the tenants in the rental apartment of national housing size. The results of this study are as follows; 1) Characteristic of household differ as the size tenants live in at present. But, usually characteristic of household was family life cycle was from child-rearing time to secondary education time, a family's number was 3${\sim}$4 person, and income per month was 1${\sim}$3 million won. 2) The satisfaction of whole and physical environment were satisfied more than average 3 points. However, the satisfaction of economic performance and administration environment were dissatisfied by average 3 points low. 3) Factors that affect in housing satisfaction were administration environment, the housing size, a family's number.

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A Study on Operation Scheme of STS with Emergency Generator for Peak Shedding (첨두부하 저감을 위한 비상발전기 연계형 STS 운영 방안에 관한 연구)

  • Kim, Chang-Hwan;Rhee, Sang-Bong;Kim, Kyu-Ho
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.155-156
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    • 2015
  • Recently, electricity consumption has rapidly increased along with economic growth. The operating strategy using emergency generator is aimed, to resolve a demand response management. For strategy of peak shedding using emergency generator, it is essential to introduce the fast transfer switching device. One of the most effective solutions is to use a static transfer switch (STS) based on thyristor. However, the characteristic of natural commutated SCR thyristor should anticipate short duration voltage sag. STS system thus requires more than a quarter cycle to successfully complete transfer process. This paper proposes the operation scheme of the STS system using the forced-commutation technique to mitigate instantaneous voltage sag during peak transfer process. Proposed STS system improved turn-off characteristic thus accomplishes the peak load shedding satisfied power quality. Performance of the proposed STS system is evaluated using electromagnetic transient program (EMTP) to confirm the effectiveness.

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A Health Index of Aged Undeground MV Cables in Domestic (경년열화된 지중 MV급 케이블의 Aging Index)

  • KIM, Yong-Hyun;KIM, Su-Hwan;LEE, Seung-Won;LIM, Jang-Seob
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1216-1216
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    • 2015
  • In this study, the author apply the VLF(Very Low Frequency) tan-delta data that has been measured at each office of the KEPCO 2012 to the Weibull distribution which is the statistical analysis as previous studies for the remaining life prediction through the improvement of the sensitivity and reliability of the degradation state assessment of underground distribution power cables. Also, in this paper, UCD(Used Cable Diagnosis) Matrix proposed by KEPCO was applied to the hierarchy of assessment prioritization. it suggests Aging Index for condition assessment and high reliability of proper economic replacement cycle using the weight according to the assessment prioritization.

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The construction management of BIM-based small building remodeling. (BIM 적용을 통한 소규모 건물 리모델링 시 현장시공관리)

  • Jung, Tae-Ho;Kim, Sang-Won;Park, Seung-Hwan;Hong, Seong-Wook
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.05a
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    • pp.191-192
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    • 2012
  • The BIM(Building Information Modeling) introduction of the construction and maintenance at the design phase through the life cycle of the building until it is destroyed, I will bring big changes in the process. If you are building a small action by a variety of variables difficult to manage on-site construction, but, BIM remodeling of the building by applying a small improvement in the quality of imported building and construction delays, such as design changes or re-construction by removing the elements of economic 04 to make. Since the early stages of applying BIM to complement the introduction part, but the future seems to lead to changes in the built environment, academics and practitioners of the construction industry seem to have an active research.

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Examination of the Optimal Insulation Thickness of Exterior Walls for Climate Change (기후변화를 고려한 외벽 최적단열두께 검토)

  • Jung, Jae-Hoon
    • KIEAE Journal
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    • v.11 no.6
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    • pp.81-86
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    • 2011
  • By strengthening the insulation performance of a building, a great deal of energy can be saved and a comfortable indoor environment can be offered to people. On the other hand, the climate, which has a great influence on the indoor environment, is changed by global warming. Therefore, in planning building envelope structure and design, climate change should be considered. In this paper, the optimal insulation thickness of exterior walls was calculated by an economic assessment method using heating degree-days. Additionally, how much influence climate change has on planning building insulation was investigated. The examination showed that heating degree-days have decreased by about 10% due to climate change in the past few decades. It was also shown that the optimal insulation thickness of exterior walls was thin, at about 6%, in three representative Korean cities (Seoul, Daejeon, Jeju).

한국의 해외 기술도입 보상구조의 결정에 관한 연구

  • Park, Hyeon-U
    • Proceedings of the Technology Innovation Conference
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    • 2004.06a
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    • pp.151-169
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    • 2004
  • Studies on compensation structures of international technology licensing show that the level of intellectual property protection in the host market and the favorableness of the host country's economic environment are positively related to the use of running royalty-based compensation structure. Lump-sum fee or fixed royalty compensation is more likely to be used in the introduction and decline stages of the technology life cycle, and running royalty compensation in the growth stage. The international experience and the size of the licensor company are positively related to the use of running royalty. In this theoretical context, this paper analyzes the compensation structures of technology import in Korea. The paper uses the officially reported data to analyze the compensation structures. It analyzes the characteristics of the compensation structures in terms of fixed royalty and running royalty by licensor country, group of licensor countries and size of licensee companies.

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Biological Characterization of Marssonina coronaria Infecting Apple Trees in Korea (사과나무를 가해하는 한국산 갈색무늬병균의 생물학적 특성)

  • Back, Chang-Gi;Jung, Hee-Young
    • The Korean Journal of Mycology
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    • v.42 no.3
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    • pp.183-190
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    • 2014
  • Apple blotch is a major apple disease and recently it causes critical economic losses in apple orchards in Korea. In this review, we described the history of apple blotch researches, ecology and life cycle of Marssonina coronaria, cultural and molecular characteristics and simple isolation method as well. Furthermore, characteristic of apple blotch like symptoms, its cause still unknown, occurs frequently in cv. "Fuji" was described in detail.