Recently, interest in the development of alternative water resources has been increasing rapidly due to environmental pollution and depletion of water resources. In particular, seawater desalination has been attracting the most attention as alternative water resources. As seawater desalination consumes a large amount of energy due to high operating pressure, many researches have been conducted to improve energy efficiency such as energy recovery device (ERD). Consequently, this study aims to compare the energy efficiency of RO process according to ERD of isobaric type which is applied in scientific control pilot plant process of each 100 m3/day scale based on actual RO product water. As a result, it was confirmed that efficiency, mixing rate, and permeate conductivity were different depending on the size of the apparatus even though the same principle of the ERD was applied. It is believed that this is caused by the difference in cross-sectional area of the contacted portion for pressure transfer inside the ERD. Therefore, further study is needed to confirm the optimum conditions what is applicable to the actual process considering the correlation with other factors as well as the factors obtained from the previous experiments.

We studied the efficiency of service quality of loan consultants contracted to a bank in Korea. Since the consultant is not an employee of the bank, he/she is paid solely in proportion to how much he/she sell loans. In this study, a consultant is considered as a decision making unit (DMU) in the DEA (Data Envelopment Analysis) model. We use a principal component analysis-data envelopment analysis (PCADEA) model to evaluate quality efficiency of the consultants. In the first stage, we use PCA to obtain 6 synthetic indicators, including 4 input indicators and 2 output indicators, from survey results in which questionnaire items are constructed on the basis of SERVQUAL model. In the second stage, 3 DEA models allowing negative values are used to calculate the relative efficiency of each DMU. An example illustrates the proposed process of evaluating the relative quality efficiency of the loan consultants.

본 연구는 연안여객선사의 안전관리 운영 효율성을 분석하기 위한 기초연구로 적절한 안전경영지표 평가항목을 설계하고 연안여객선 사를 대상으로 평가항목의 유효성을 검증하는데 목적이 있다. 이를 위해 먼저 연안여객운송사업자의 안전관리책임자, 공무원(선박검사관), 여객 선 운항관리자 등으로 구성된 전문가 그룹을 통해 연안여객선사의 자발적 안전관리 활동을 평가하기 위한 5개의 평가항목과 14개의 세부 평가요 인을 선정하고 사전검증 및 테스트를 통해 객관성을 제고하였다. 이 안전경영지표 평가항목을 이용하여 44개 연안여객선사에 대한 자발적 안전 관리 수준을 평가하였다. 그리고 평가항목의 유효성을 검증하기 위하여 안전경영지표 평가항목 결과와 중대해양사고 비율을 비교분석하여 평가 항목의 타당성을 확인하였다. 이를 통해 자발적 안전경영 수준이 높은 업체일수록 중대해양사고가 발생하지 않고 자발적 안전관리에 무관심하거 나 소홀한 업체는 상대적으로 높은 중대해양사고가 발생하고 있는 것을 알 수 있었다. 이처럼 안전경영지표 평가항목 선정을 통해 연안여객선사 의 안전관리 운영 효율성을 분석하는데 중요한 항목을 객관적인 관점에서 도출하였다. 따라서 향후 안전관리 효율성 분석을 위한 기초자료로 활 용될 수 있을 것이다.

Loan consultants assist clients with loan application processing and loan decisions. Their duties may include contacting people to ask if they want a loan, meeting with loan applicants and explaining different loan options. We studied the efficiency of service quality of loan consultants contracted to a bank in Korea. They do not work as a team, but do work independently. Since he/she is not an employee of the bank, the consultant is paid solely in proportion to how much he/she sell loans. In this study, a consultant is considered as a decision making unit (DMU) in the DEA (Data Envelopment Analysis) model. We use a principal component analysis-data envelopment analysis (PCA-DEA) model integrated with Shannon’s Entropy to evaluate quality efficiency of the consultants. We adopt a three-stage process to calculate the efficiency of service quality of the consultants. In the first stage, we use PCA to obtain 6 synthetic indicators, including 4 input indicators and 2 output indicators, from survey results in which questionnaire items are constructed on the basis of SERVQUAL model. In the second stage, 3 DEA models allowing negative values are used to calculate the relative efficiency of each DMU. In the third stage, the weight of each result is calculated on the basis of Shannon’s Entropy theory, and then we generate a comprehensive efficiency score using it. An example illustrates the proposed process of evaluating the relative quality efficiency of the loan consultants and how to use the efficiency to improve the service quality of the consultants.

This study introduces the comparison of efficiency levels of photovoltaics systems by analyzing various installation systems of photovoltaics systems and optimization techniques and proposes a system using techniques In this study, the generation time and power generation of two types of photovoltaic power generation system were measured and compared. Comparing the monthly power generation time with the power generation amount, it is found that there are many fixed variable photovoltaic power generation systems with a large average daily power generation time of 0.8h and an average power generation capacity of 2,871kw from November to December. Total Fixed Variable Total Daily Power Generation Time 2.4h The power generation amount is 23,184kw, showing a large amount of electric power generation.

This paper was to evaluate social enterprises’ management efficiency with Data Envelope Analysis (DEA). The data was based on the 168 social enterprises’ of annual performance reports published in 2015. The research focused on to measure both financial efficiency and social impact of the companies simultaneously. To apply DEA, the paper classified the enterprises into seven types based on types of socal impacts which each company provides before the estimation of the efficiency. The research results showed that group D, which employes disadvantaged people, provides social services and shares resources was the most efficient group and had higest net worths in Pure Technical Efficiency. In contrast, Group B, which only employs social advantage people and provides social service, was the least efficient one. The research suggests a practical and efficient framework in measuring social enterprises’ management efficiency, including both the financial performance and social impacts simultaneously with their self-publishing reports. Because the Korea Social Enterprise Promotion Agency does not open business reports which social enterprises submit each year, there are basic limitations on researchers attempting to analyse with data from all social enterprises in Korea. Thus, this study dealt with only 10% of the social enterprises which self-published their performance report on the Korea Social Enterprise Promotion Agency’s web site. Regardless of these limitations, this study suggested substantial methods to estimate management efficiency with the self-published reports. Because self-publishing is increasing each year, it will be the main source of information for researchers in examining and evaluating social enterprises’ financial performance or social contribution. The research suggests a practical and efficient framework in measuring social enterprises’ management efficiency, including both the financial performance and social impacts simultaneously with their self-publishing reports. The research results suggest not only list of efficient enterprises but also methods of improvement for less efficient enterprises.

Cutting tools tend to wear gradually with progressing of machining process due to extremely high surface loads and temperature from the relative motions between tool and workpiece. Especially, the high cutting temperature is a dominant factor in the relation to tool life. High-pressure coolant has been reported as an effective method to prevent the severe wear from cutting temperature. This research investigates efficient supplying conditions of high-pressure coolant with the CFD results from a internal-flush drilling process. The flow rate of coolant is increased drastically up to three times under 70 bar compared to conventional way.

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.

PURPOSES: The goal of this study is to analyze the operational efficiencies of special roundabouts using simulated programs. METHODS: This study primarily focuses on comparing the delays and traffic flow disturbances occurring at special roundabouts. In this study, the operational efficiencies of 450 scenarios (5 roundabout types × traffic volumes × directional ratios × measures) are analyzed according to the corresponding delays and traffic flow disturbances using VISSIM and SSAM. RESULTS : The main results are as follows: 1) the Hamburger roundabouts are determined to yield the least common-type delays, 2) the amount of delays at Turbo and Flower roundabouts with respect to relatively increased right-turn-type delays, in addition to the amount of delays at the Left-turn slip-lane roundabout with respect to relatively increased left-turn-type delays, are found to be reduced as compared to the common-type delays. Lastly, common- and increased right-turn-type traffic flow disturbances at the Turbo roundabout and increased left-turntype traffic flow disturbances at the Left-turn slip-lane roundabout are determined to be the most infrequent. CONCLUSIONS: This study comparatively analyzes five roundabout types: standard, Flower, Turbo, Hamburger, and Left-turn slip-lane. The effectiveness of roundabouts can increase according to given traffic volume, directional ratio, and measure of effectiveness.

The analytical investigations of the filtering efficiency with multi-layered stainless screen filter, which is designed to generate swirling stream of micro metal dust from industrial manufacturing processes, were conducted. Compared to general filter dust collecting using bag filter, it can be expected that the metallic screen filters in this study enable the higher dust collecting efficiency of a system to be maintained even under harsh filtering conditions. The CFD analysis includes dust particles behavior, filtering efficiency, and pressure loss in the flow-field. The results show that the proposed 16 layered screen filter is able to collect 10 microns metal dust up to 97 % under 487.84 ㎩ differential pressure.

본 사례는 공작기계산업의 A사에서 수행한 R&D 개발완료 과제 79건을 대상으로 R&D 효율성을 DEA를 활용하여 분석하고, 그 개선방안을 제시한 것이다. DEA 분석에서투입변수는 R&D 투자비와 연구인력 맨먼스, 산출변수는 개발기간 목표달성률과 예상매출액(5년간)으로 설정하였으며, 표본은 제품, 선행기술, 제어기술로 구분하여 분석하였다. 여기서선행기술은 제품성능을 위한 요소기술과 응용프로그램을 개발하는 것이고 제어기술은 컴퓨터를 토대로 수치제어 프로그램을 설계하는 것이다. 분석결과에 따르면 제품, 제어기술, 선행기술 순으로 효율적으로 운영되고 있어 선행기술의 효율성이 가장 낮았다. 그 이유는 선행기술의 불학실성에 기인한다. 선행기술은 개발목표를 정하기 어렵고 개발계획도 수립하기 어렵다. 심지어 운영하는 과정에도 환경변화가 영향을 미친다. 투자효율성 분석결과에서 CRS는 제품 34.6%, 선행기술 14.3%, 제어기술 38.9%이다. IRS는 제품 53.8%, 선행기술 85.7%, 제어기술 38.9%이다. DRS는 제품 11.5%, 선행기술0%, 제어기술 22.2%이다. 전체적으로 본 사례는 과다투입보다는 과소투입이 문제가 되고 있다. 이는 R&D 투자 부족을 의미한다. 주목할 부분은 기업의 미래 경쟁력이 될 수 있는 응용기술에 대한 과소투입이 심각하다는 것이다. 비효율적 DMU의 효율적 운영을 위해서는 최적의 투입량을 관리해야하며, 이것은 준거집단과의 비교를 통해 구할 수 있다.

본 연구에서는 capacitive deionization(CDI) 공정에 사용되는 셀을 디자인하여 염 제거 성능비교 연구를 수행하였다. 디자인한 셀의 데드존을 알아보기 위하여 computational fluid dynamics(CFD)로 분석하였다. CFD분석은 15, 25, 35ml/min 의 유속에서 진행하였으며, 같은 유속에서의 CDI 결과와 비교하였다. hexagon flow channel 1(HFC1), hexagon flow channel 2(HFC2)의 경우 15ml/min의 유 속에서 88-124%효율을, 25ml/min 에서는 49-50%의 염 제거 효율을 나타내었다. 35ml/min의 유속에서는 HFC1과 HFC2를 foursquare flow channel (FFC)와 비교해보았을 때 차이가 없었다.

현재 항로표지시설에 대한 객관적 지표 및 평가기준에 따른 적정성 및 효용성 등 사후평가는 설치 이후 항만 운영 중 변경될 수 있는 위험요소 및 환경 변화를 고려하여 이루어지지 않고 있는 실정이다. 항로표지시설에 대한 객관적 지표를 설계하여 모든 항로표지시설에 공통된 평가기준 및 분석모델을 적용하여 환경 및 항만 여건 변화에 따른 적정성 및 효용성을 분석할 필요성을 인식하고, 이 연구에서는 우선적으로 항로표지시설 중 전국 37기가 운영 중인 유인등대를 중심으로 20개의 기능평가 지표를 설계하고 적용하였다. 객관적 평가지표에 따라 기능평가 후 계층분석과정(AHP, Analytic Hierarchy Process) 기법을 통해 항만 운영의 특성, 국가정책, 전문가 의견 등을 반영하였으며, 항로표지시설의 특수성 평가를 위해 리커트척도(Likert scale)를 적용하여 사후평가 하였다. 효용성분석 결과 전체 37기 중 영도등대, 가거도등대, 거문도등대, 죽변등대의 기능 및 효용성이 높은 것으로 분석되었으며, 울릉도등대, 가사도등대, 송대말등대, 울기등대의 경우 세부적인 적정성분석이 이루어질 필요가 있는 것으로 분석되었다. 이러한 항로표지시설 효용성분석은 항로표지시설의 관리체계의 효율성 향상, 항로표지의 재배치 및 정책결정을 위한 기초자료 등으로 활용할 수 있을 것이다.

With the interest on operational efficiency due to the rapid growth of food material distribution industry and food service industry, the study adopts DEA (Data Envelopment Analysis) model and examines to measure the technological, pure technical and scale efficiency those companies engaging in the food material distribution and food service business. As a result of analysis, the companies operating integrated business have relatively higher efficiency than those operating only food material distribution or food service companies while the result indicates that three efficiencies don’t have significant difference depending on whether affiliated companies or not. In the results from the measuring by DEA.

This study applied the Stochastic Frontier Analysis to estimate which independent variable affects to efficiency of aquaculture household. This study used wage and facility scale as input variables, sales volume as an output variable to estimate efficiency. Also, the study used region, species, water quality to estimate technical inefficiency factors of the model. The data used for this study were obtained by the operating costs survey using 1:1 interview method. The study selected translog production model with technical inefficiency term estimated as half-normal distribution. In addition, the study used pearson and spearman correlation coefficient among efficiency estimating models. Also, the study analysed differences among estimated efficiencies through t-test, and showed us 0.1793 in species, 0.4677 between Geojae and Masan.