• 한국국방경영분석학회지
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• 제33권2호
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• pp.61-73
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• 2007

본 연구의 목적은 미래 기술예측에 사용되는 TFDEA(Technological Forecasting with Data Envelopment Analysis)의 문제점을 살펴보고 이의 개선방향을 찾아 주력전차의 기술예측 문제에 적용해 보는 것이다. 기존의 TFDEA는 복수의 DMU(Decison Making Unit)를 효율적 DMU로 판정하는 DEA(Data Envelopment Analysis)의 특성상 실제로는 그다지 효율적이지 않은 DMU까지 포함해서 기슬예측을 수행함으로써 예측 결과의 정확도가 저하될 수 있다. 본 연구에서는 DEA의 확장된 개념을 적용하여 평가 대상 DMU에 대한 순위를 산정한 후 이를 토대로 기술 예측을 시행하는 방법을 검토해 보았다. 이를 위해 일반적인 DEA기반의 순위선정 방법 중 대표적인 Super-efficiency, Cross-efficiency, CCCA(Constrained Canonical Correlation Analysis)을 TFDEA에 결합 적용하고 이들을 비교해 보았다. 제시된 방법을 주력 전차의 미래 기술 예측 문제에 적용한 결과 CCCA를 이용한 순위선정방법이 실제 실현된 기술 수준과 비교했을 때 통계적으로 가장 작은 오차율을 보였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2022년도 춘계학술대회
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• pp.198-200
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• 2022

With the expansion of the global supply chain, the efficiency of maritime logistics is considered a crucial factor for countries' trade and competitiveness. Nevertheless, prior research has not thoroughly evaluated the efficiency of maritime logistics, including countries' ports and shipping capacities. Accordingly, this study examines integrated maritime logistics efficiency at the national level using DEA-CCR, BCC, and super-efficiency DEA. Furthermore, this study identifies a difference between the selected countries' maritime logistics efficiency and LPI (Logistics Performance Index) through Spearman's correlation test as an ad-hoc analysis. From this, Asian countries showed higher efficiency and European countries showed higher LPI scores. These results might be derived from this difference in port-city development patterns. Additionally, the main cause of inefficiency in Europe and Japan might be attributed to high fleet capacity of control. Consequently, this study can provide valuable implications for coastal countries to set more efficient directions for maritime logistics investment and policy.

• 전기학회논문지
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• 제57권12호
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• pp.2285-2290
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• 2008

Even though efficiency of coal-fired power plant is proportional to operating temperature, increasement of operating temperature is limited by a technological level of each power plant component. It is an alternative plan to increase operating pressure up to ultra super critical point for efficiency enhancement. It is difficult to control process of power plant in ultra super critical point because that point has highly nonlinear characteristics. In this paper, new control logic, Unit Response Optimizer Controller(URO Controller) which is based on Fuzzy logic and Model Predictive Controller, is introduced for better performance. Then its performance is tested and analyzed with design guideline.

• 해양환경안전학회지
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• 제23권2호
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• pp.161-167
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• 2017

본 연구는 3개의 투입변수와 3개의 산출변수로 구성된 DEA법을 이용하여 우리나라 항만의 노무효율성을 측정 평가하였다. 대상항만의 전체 기술적 효율성은 평균 94.18% 수준이었으며, 순수 기술적 효율성은 100%로 나타났고 규모의 효율성은 94.18%로 전체 기술적 비효율성이 가장 높게 나타났다. 분석결과 7개의 항만은 효율적인 항만으로 측정되었고 4개의 항만은 비효율적 항만으로 측정되었다. 4개의 비효율적 항만중 규모에 대한 수익체증은 동해항으로 나타났다. 그러나 비효율적인 항만들은 생산규모의 비효율성보다 자원운영의 비효율성이 높은 것으로 나타났다. 한편 초효율법을 이용하여 효율적인 항만의 우선순위를 분석한 결과 인천항, 목포항, 평택당진항, 마산항, 여수광양항, 제주항, 군산대산항 순으로 효율성이 높은 것으로 나타났다. 특히 비효율적인 부산항은 목포항 및 인천항을 벤치마킹하여 항만 물동량의 증대, 장비의 현대화 및 노무효율성의 향상을 위해 전면적인 노무상용화가 필요하다.

• 조명전기설비학회논문지
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• 제29권11호
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• pp.35-40
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• 2015

In accordance with global energy conservation policies such as MEPS (Minimum Energy Performance Standard), electric motor industry is moving to super-high-efficiency machines and research to develop IE4 (International Energy Efficiency Class 4) motors has been launched. In this situation, SynRM (Synchronous Reluctance Motor) has been attracting attention in place of induction motor which hardly provides super premium efficiency. As a result, much research on SynRM is being performed at home and abroad. Also, some products have already been appearing in the market. Compared to induction motor, SynRM has better efficiency per unit area and wider operating range. Although the utilization of control system in synchronous motor results in higher prices, we still need to concentrate on developments of SynRM so as to comply with the new policies. This study demonstrated the electromagnetic design methods of super premium SynRM while maintaining the frame of existing IE3 induction motor. We documented the design procedures for generating high saliency which is the most essential and mechanical stress anlaysis is also treated. In conclusion, we proved the validity of our design by manufacturing and testing our 3 models.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.402-407
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• 2003

The main reason to select the maxium plant efficiency through the performance test in fossil power plant is to increase the efficiency of power plant as well as saving energy collated with the policy of government. This study is aimed at unerstanding the variantion trend of efficiency and analyzing the efficiency of boiler and turbine through each of the performance test. Ultimately, the maxium efficiency of power plant will be presented in super-critical pressure type power plant.

• 한국태양에너지학회 논문집
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• 제29권6호
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• pp.39-44
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• 2009

Entering in the time of high oil price, seriousness of an energy effect sector has given a huge impact and the importance of energy is growing. Especially, building energy occupying 24% of total demand of energy is expected to be possible to reduce energy demand more than other section. To reduce the building energy consumption, this study analyzes function and thermal performance of Super window by heat experimental apparatus. Super window is a 2-track low-e glazing window for high insulation efficiency. By applying the results of this experiment to building energy efficience rating tool, this study compares energy efficiency rates depending on a region.-Jeju, South, Central. And it shows how much does Super window reduce Building energy consumption.

• 한국유기농업학회지
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• 제23권2호
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• pp.207-231
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• 2015

This study evaluate examines the efficiency and the improvement measurement of Oilseed crops (Sesame and Perilla). For this purpose, In the first stage, this study analyzes the current conditions of oilseed industry. In the second stage, this study evaluates the efficiency and super-efficiency of environmentally-friendly agricultural product producers. The result of this study show that: (1) Changes in annual wholesale price of Sesame and Perilla; (2) An efficiency and ranking of environmentally-friendly product producers; (3) The solutions and improvement measurements for inefficient producers.

• 품질경영학회지
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• 제35권3호
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• pp.21-36
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• 2007

This article is to analyze the service efficiency of public sector using Data Envelopment Analysis(DEA). We tried to measure the public service quality and overall satisfaction by using several DEA models, degree of combination and top2box which is a little bit different methodology from traditional ones. We used CCR, Super-efficiency and Slack based measure(SBM) model in DEA to measure public service efficiency of the 16 public institutions(7 City Halls and 9 Provincial offices). Since the traditional method based on the measurement model(CCR, BCC) has the fundamental problems without taking account of the existence of slacks inputs and outputs in several efficient units, we suggest to measure the exact amount of efficiency and inefficiency of the public sector and rank analysis many efficient units exactly through the slacks-based measure model(SBM)

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.320-325
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• 2005

Power of fuel cell tram is supplied by only fuel cell system or hybrid system of fuel cell and battery/super capacity. Fuel cell is operated by hydrogen, which is fed directly from hydrogen tank or by reforming gasoline or methanol into hydrogen. Power system is preferred with hybrid of fuel cell and battery/super capacity since it improves total energy efficiency through interaction of hybrid components and restores energy regenerated by braking. Also, power supply system by fuel cell hybrid should be designed to output optimum energy efficiency depending on driving mode of fuel cell tram.