• Title/Summary/Keyword: efficiency assessment

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소형 가스엔진 열병합발전 시스템의 안전관리 방안에 관한 연구 (A Study on the Safety Management Methods of Micro-Gas Engine Combined Heat and Power System)

  • 김소현;김민우;이은경;이정운
    • 한국가스학회지
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    • 제22권6호
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    • pp.76-89
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    • 2018
  • 지속적인 산업 발전에 따른 에너지 수급의 불안정 및 환경오염 문제가 대두됨에 따라 이에 대한 해결 방안의 일환으로 열병합발전 시스템의 보급이 활발해지고 있다. 국내의 경우 가스엔진을 이용한 열병합발전기의 안전성능에 대한 검사기준이 미비하므로 이에 대한 연구가 필요한 실정이다. 본 연구에서는 20 kW급 가스엔진 열병합발전 시스템에 적용 가능한 안전성능 관련 표준화 연구 수행을 위해 열병합발전 시스템의 국내 외 기준에 대한 안전성능 및 구조/재료 평가기준을 분석하였다. 또한, 위험요소 분석 및 HAZOP (Hazard and Operability Studies)을 이용한 위험성평가를 수행하여 가스엔진 열병합발전 시스템의 안전성능 평가(안)을 도출하였으며, 평가항목으로는 안전성능 관련 엔진 시동, 배관 기밀 성능, 살수 및 온도 상승 성능, 연소 성능, 전기 효율, 열효율, 종합 효율, 습도 성능 등이 포함된다. 가스엔진 열병합발전 시스템의 구조 및 재료와 관련하여 가스 및 수배관, 가스 조절 및 차단밸브, 금속 또는 비금속 재료의 내구성, 내열성, 내한성에 대한 평가항목을 도출하였다.

경제성 평가에 의한 군함의 초기설계에 관한 연구 (A Study on Preliminary Design of Warships by Economic Evaluation)

  • 신수철
    • 대한조선학회논문집
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    • 제45권2호
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    • pp.221-228
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    • 2008
  • This paper describes to determine optimum main particulars of warships which satisfy user's requirements in a concept design stage with minimum construction cost and maximum transportation efficiency. Present worth was used as an assessment criteria of the economical efficiency. And Pareto optimal set was used to have the optimum design.

Productivity Growth of Vietnamese Commercial Banks: An Application of Non-Parametric Analysis

  • NGUYEN, Manh Hung
    • The Journal of Asian Finance, Economics and Business
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    • 제8권9호
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    • pp.177-187
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    • 2021
  • The purpose of the research to evaluate the efficiency and productivity growth rate of some Vietnamese commercial banks in the period 2008-2020. Using input and output selection theory, the author selected 2 models, estimating the efficiency for model 1 and estimating the yield change for both the models. We have built a model to estimate the efficiency and calculate as well as decompose the productivity growth of Vietnamese commercial banks during the period of active mergers and acquisitions activities in the banking system. Based on the results of the efficiency estimation, TFP shows during mergers and acquisitions, efficiency fluctuates but in an inverted U-shape (increasing from 2008-2011 but decreasing from 2013 to 2020). The estimated results of the impact assessment model show that FDI reduces the efficiency of banks. Productivity analysis shows that 6 out of 23 banks in the study period had positive TFP growth (tfpch > 1) due to technical progress and management efficiency. The findings of this study suggest that Vietnam's commercial banking system has many opportunities to improve operational efficiency in many aspects. In which, there are opportunities to increase credit, improve governance as well as improve the technology level of each bank. In addition, along with traditional products such as deposits and loans, diversification with a wide range of products and services is an important factor to enhance customer experience and demand in commercial banks.

DOProC-based reliability analysis of structures

  • Janas, Petr;Krejsa, Martin;Sejnoha, Jiri;Krejsa, Vlastimil
    • Structural Engineering and Mechanics
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    • 제64권4호
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    • pp.413-426
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    • 2017
  • Probabilistic methods are used in engineering where a computational model contains random variables. The proposed method under development: Direct Optimized Probabilistic Calculation (DOProC) is highly efficient in terms of computation time and solution accuracy and is mostly faster than in case of other standard probabilistic methods. The novelty of the DOProC lies in an optimized numerical integration that easily handles both correlated and statistically independent random variables and does not require any simulation or approximation technique. DOProC is demonstrated by a collection of deliberately selected simple examples (i) to illustrate the efficiency of individual optimization levels and (ii) to verify it against other highly regarded probabilistic methods (e.g., Monte Carlo). Efficiency and other benefits of the proposed method are grounded on a comparative case study carried out using both the DOProC and MC techniques. The algorithm has been implemented in mentioned software applications, and has been used effectively several times in solving probabilistic tasks and in probabilistic reliability assessment of structures. The article summarizes the principles of this method and demonstrates its basic possibilities on simple examples. The paper presents unpublished details of probabilistic computations based on this method, including a reliability assessment, which provides the user with the probability of failure affected by statistically dependent input random variables. The study also mentions the potential of the optimization procedures under development, including an analysis of their effectiveness on the example of the reliability assessment of a slender column.

환경비용을 고려한 공공시설물의 환경경제성 평가 -국내 다목적댐 비상여수로 시설 사례연구 - (The Economic Efficiency Assessment of Infrastructure considering Environmental Cost - A Case Study of Emergency Spillway for Korean Multipurpose Dam -)

  • 권석현;김상범
    • 한국건설관리학회논문집
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    • 제8권3호
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    • pp.168-176
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    • 2007
  • 본 연구는 LCA(Life Cycle Assessment, 전과정평가) 개념을 바탕으로 공공 시설물의 환경성 및 경제성 평가를 위한 의사 결정시 유용한 정보를 제공하기 위하여 사례대상으로 선정된 다목적댐 비상여수로의 위치 및 형식별로 발생 가능한 환경오염물질에 대한 환경 비용을 예측하고자 하였다. 이를 위해 LCA 기 법 및 조건부가치측정 법(Contingent Valuation Method, CVM)의 이론을 고찰하고, 환경 비용 분석모델을 제안하였다. 제안된 공공시설물 환경비용 분석모델을 사례대상인 다목적 댐 비상여수로에 적용하기 위해 전과정 동안 발생하는 환경오염물질에 대한 환경부하량을 산출하고, 이를 비용으로 환산하여 환경비용을 예측하였고, 예측결과를 통하여 비상여수로의 환경경제성을 평가하고 친환경적이고 경제적 인 치적대안을 도출하였다.

캡스톤디자인 교과목 기반의 프로그램 학습성과 평가 연구 (A Study on the Assessment of Program Outcomes Based on Capstone Design Course)

  • 이희원;김성환;박근;김정엽
    • 공학교육연구
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    • 제13권6호
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    • pp.143-151
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    • 2010
  • 본 논문은 서울과학기술대학교(구 서울산업대학교) 기계설계자동화공학부에서 16년간의 캡스톤디자인 운영경험과 개선을 바탕으로 캡스톤디자인 교과목 기반의 프로그램 학습성과의 평가 사례에 대해 서술하였다. 우선, 캡스톤디자인 교과목과 관련된 프로그램 학습성과를 소개하였고, 평가 방법 및 항목에 대해서 설명하였다. 이를 바탕으로 하여 2008년도의 학습성과 평가 결과를 도출하였고, 이를 분석한 후 개선 전략을 수립하였다. 전략으로서 학생들에게 심사 기준과 모범사례를 온라인상에 미리 공개하였고, 그 결과 2009년도에는 전반적으로 약 3.3% 개선된 학습성과 평가 결과를 얻을 수 있었다. 마지막으로 코스 임베디드 평가 개념 측면에서 캡스톤디자인 교과목을 이용한 프로그램 학습성과 평가의 타당성, 효율성, 내실성, 그리고 지속가능성에 대해서도 논의하였다.

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지방공무원 역량평가제도의 인식과 발전방안 대한 연구 - B광역시를 중심으로 - (A Study on the Recognition and Development plan of Local official's Competency assessment system in B Metropolitan city)

  • 양승은;강버들
    • 수산해양교육연구
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    • 제29권2호
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    • pp.479-491
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    • 2017
  • The purpose of this study is to seek the recognition and development method of the competency assessment in order to set up the competency assessment system introduced for the manager promotion in B metropolitan city. The following conclusion were obtained by studying the recognition of competency assesment system of candidates for promotion and non-candidates. First, it is found that non-candidates have a higher recognition of the necessity of competency assessment system and its credibility, fairness and influence on relieving nepotism than candidates for promotion. Second, competency factors that recognized to be necessary for the performance of manager's role were direction guidance, fostering members, integrative thinking and communication in sequence by candidates for promotion, while direction guidance, communication, integrative thinking and management of organization in sequence the non-candidates. Third, in terms of the operational aspect of the competency assessment system, both candidates and non-candidates wanted a pass rate of 70~90%. And the time required for the assessment task was most favored for 1~2hrs, and the judges of the competency assessment were preferred in the order of professors, public official, consultants, and headhunters. Fourth, $1^{st}$ candidates than non-candidates recognized that the person who are from $5^{th}$ or $7^{th}$ class appointment are younger, have high education, are better at presenting, are in administrative positions, and are more optimistic would be more advantageous in competency assessment.

생산 가능한 토지면적산정기법을 이용한 지속성 평가에 대한 연구: 제주도 지역을 중심으로 (The Assessment of the Sustain ability on Human Activities through Ecologically Productive Land Calculated by the Ecological Footprint of Cheju Island)

  • 김용범;현연주;정용
    • 환경영향평가
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    • 제6권2호
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    • pp.103-112
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    • 1997
  • The object of this study is the introduction and the application of Ecological Footprint(EF) for sustainability of regional people activities. It is a tool for the evaluation of specific projects through various lifestyles or consumption to area of broad policy and budgets. But in Korea there is no assessment for consumption level of human activities by EF. Therefore this study try to analyse ecologically productive land for human activities of Cheju-island in order to assess the sustainability in Cheju and compares with another industrized countries. We analyze the human activities level of Cheju-island then the EF is about 0.9(ha/cap). This value is not more than another countries like Canada and United States. EF assists in choosing technologies, policies and Life Cycle Assessment(LCA) which can perform a certain task with the smallest ecological footprint. It will help society to avoid collapse and move towards sustainability and ecological efficiency.

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가압중수로 증기발생기의 경년열화 관리를 위한 안전성 평가 시스템 개발 (Development of a Safety Assessment System on Aging Management in Existing CANDU Steam Generators)

  • 신소은;이정훈;박동규;정종엽
    • 시스템엔지니어링학술지
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    • 제10권1호
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    • pp.49-56
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    • 2014
  • Since steam generator (SG) tubes are located in the boundary between the primary and secondary systems of nuclear power plant (NPP), the SG is one of the most important components in the aspects of the safety of NPP. The magnetite ($Fe_30_4$) deposition, so-called fouling, is generally known as a major aging mechanism of CANDU SGs, and this aging mechanism makes the heat transfer efficiency between the primary and secondary systems of NPP reduced. Therefore, the development of SG safety assessment system which can evaluate the effect of the SG aging degradation mechanism should be needed for safety of NPP. In this study, through the suggestion of the guideline for SG safety assessment, it is possible to strengthen the basic of establishing the effective SG aging management technique. The SG safety assessment is carried out by CATHENA(Canadian Algorithm for THErmalhydraulic Network Analysis). It is possible to determine the integrity of SGs by identifying the main safety parameters which can be changed by the aging degradation of CANDU SGs.

초기 설계단계 에너지 성능평가를 위한 IFC 기반 IDF 변환기 개발 (Development of the IFC based IDF Converter for Energy Performance Assessment in the Early Design Phase)

  • 김인한;김지은;최중식
    • 한국CDE학회논문집
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    • 제16권2호
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    • pp.146-155
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    • 2011
  • As the seriousness of environmental pollution being on a rise, a low carbon and environment-friendly design for energy efficiency has been issued. With respect to energy in the construction industry, an adoption of BIM which is possible for the various energy performance assessments in the early design phase has been actively working on. In the most cases of energy performance assessment, the data compatibility from the lack of standard software and format became a problem and the improvement for data compatibility system has been needed. This study is to develop the IFC based IDF converter as a middleware which connects between BIM software and energy analysis software. For the building energy performance assessment, Energy Plus and IFC are selected for the standard energy analysis software and its file format. Parameters are organized by steps and the integrated material library is built so it is trying to reduce the existing problem of energy software interface as much as possible. The development of IDF Converter will promote the spread of related fields with increasing the BIM standard and the utilization of energy performance assessment.