• 기술혁신학회지
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• 제19권1호
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• pp.191-229
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• 2016

우리나라 국가연구개발사업의 규모가 꾸준히 증가하면서 국가 R&D 예산의 투자 효율성 효과성 제고 필요성에 대한 꾸준한 논의가 이루어져 왔다. 따라서 국가연구개발사업의 효율성 효과성 제고를 위한 성과평가체계 구축에 노력하고 있으며 국가연구개발사업 상위평가 결과와 차기 년도 예산배분과의 연계를 명문화한 것이 대표적인 제도이다. 그러나 '국가연구개발사업 상위평가 결과 우수 등급 이상인 사업은 예산을 증액하며, 미흡 이하의 사업은 감액한다.'는 법 제도상 명문화된 규정과는 다르게 성과평가 결과와 예산배분 간 연계의 실효성에 대해서는 다양한 선행연구를 통해 나타났듯이 엇갈린 평가가 이뤄져 오고 있다. 본 연구에서는 그 간의 논란이 되어온 성과평과와 예산배분구조 연계정책 관련 법 제도적 명문화 규정의 순기능 작동여부에 대해 명확히 실증하기 위해 패널회귀분석 및 정량적 데이터를 활용하여 분석을 추진하였다. 또한 국가연구개발사업 성과평가결과와 예산배분 구조의 연계성을 저해하는 원인에 대해 분석하고 이러한 저해요인 최소화를 통해 성과평가 제도의 체계성 및 평가결과의 신뢰성을 극대화하기 위한 다각적인 고도화 방안에 대해 고찰하였다.

• 한국태양에너지학회 논문집
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• 제32권2호
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• pp.19-27
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• 2012

This paper describes an experimental study on efficiency of solar collector in solar water heating system connected to hourly water heating load. In general, the functional form of solar efficiency is expressed as a function of fluid temperature entering solar collector, ambient temperature, and solar irradiance. When energy saving from solar heating of water heating system is analyzed on along-term basis such as one year with given solar irradiance data, simplified analysis is more convenient han detailed system simulation for quick assessment. However, the functional form of the efficiency is not convenient for approximately simplified energy analysis because the inlet temperature can be obtained through a detailed system simulation. In the study, solar collector efficiency is obtained with various daily water heating load sand daily solar irradiance using experimental tests. The study also considers large residential buildings such as apartment buildings for application of solar water heating systems. From test results, it is found that daily solar collector efficiency is proportional to daily water heating loads and daily solar irradiance. The data obtained from the study can be utilized to find a functional relation between daily solar irradiance and daily heating load in stead of collector inlet temperature for application of solar collector efficiency to long-term approximated energy analysis of solar heating system.

• International Journal of Railway
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• 제6권2호
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• pp.33-44
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• 2013

In recent years, energy consumption in the transportation sector by expanding motorization continues to increase in almost every country in the world. Moreover, the growth rate of the transportation energy consumption is significantly higher than those of the civilian and industrial sectors. Therefore, every country strives to reduce its dependence on private transport, which is the main contributor to the transportation energy consumption. In many countries, concepts such as Transit Oriented Development (TOD) or New Urbanism, which controls road traffic by increasing the proportion of the public transportation significantly, have been implemented to encourage a modal shift to public transport. However, the level of change required for eliminating environmental problems is a challenging task. Minimizing transportation energy consumption by controlling the increase of the traffic demand and maintaining the level of urban mobility simultaneously is a pressing dilemma for each city. Grasping the impact of the diversity of the urban transport and infrastructure is very important to improve transportation energy efficiency. However, the potential for reducing urban transportation energy consumption has often been ineffectively demonstrated by the diversity of cities. Therefore, the accuracy of evaluating the current efficiency rate of the urban energy consumption is necessary. Nevertheless, quantitative analyses related to the efficiency of transportation energy consumption are scarce, and the research on the current condition of consumption efficiency based on international quantitative analysis is almost nonexistent. On the basis of this background problem definitions, this research first built a database of the transportation energy consumption of private modes in 119 cities, with an attempt to reflect individual travel behaviors calculated by Person Trip data. Subsequently, Data Envelopment Analysis (DEA) was used as an assessment method to evaluate the efficiency of transportation energy consumption by considering the diversity of the urban traffic features in the world cities. Finally, we clarified the current condition of consumption efficiency by attempting to propose a target values for improving transportation energy consumption.

• 한국습지학회지
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• 제16권3호
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• pp.371-381
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• 2014

현재까지 국내에서 수질관리 정책이 점오염원 관리를 우선 시 하고 있다. 비점오염원은 배출특성, 배출지점 및 배출량의 파악에 매우 어려움이 있다. 이러한 비점오염 관리를 위해 다양한 비점오염저감시설들에 대한 개발 및 연구가 진행되고 있다. 비점오염시설의 평가를 위해 다양한 효율산정 방법들이 제시되고 있다. 본 연구에서는 강우 시 식생수로 모니터링 결과를 통해 체류시간이 저감효율에 미치는 영향에 대해 연구를 수행하였다. 또한 여러 가지 저감효율 산정 방법에 따른 차이를 비교하고자 하였다. 식생수로에서 체류시간에 따른 효율 분석 결과 체류시간이 길수록 저감효율도 높아지는 것으로 나타났다. 이는 식생수로의 안정적인 저감효율을 확보하기 위해선 충분한 체류시간이 확보 되어야 한다고 판단된다.

• 방사선산업학회지
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• 제17권4호
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• pp.471-479
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• 2023

In In-situ radioactivity measurement techniques, efficiency calibration models use predefined models to simulate a sample's geometry and radioactivity distribution. However, simplified efficiency calibration models lead to uncertainties in the efficiency curves, which in turn affect the radioactivity concentration results. This study aims to develop an efficiency calibration optimization methodology to improve the accuracy of in-situ gamma radiation measurements for byproducts from industrial facilities. To accomplish the objective, a drive mechanism for rotational measurement of an byproduct simulator and a sample was constructed. Using ISOCS, an efficiency calibration model of the designed object was generated. Then, the sensitivity analysis of the efficiency calibration model was performed, and the efficiency curve of the efficiency calibration model was optimized using the sensitivity analysis results. Finally, the radiation concentration of the simulated subject was estimated, compared, and evaluated with the designed certification value. For the sensitivity assessment of the influencing factors of the efficiency calibration model, the ISOCS Uncertainty Estimator was used for the horizontal and vertical size and density of the measured object. The standard deviation of the measurement efficiency as a function of the longitudinal size and density of the efficiency calibration model decreased with increasing energy region. When using the optimized efficiency calibration model, the measurement efficiency using IUE was improved compared to the measurement efficiency using ISOCS at the energy of ²²⁸Ac (911 keV) for the nuclide under analysis. Using the ISOCS efficiency calibration method, the difference between the measured radiation concentration and the design value for each simulated subject measurement direction was 4.1% (1% to 10%) on average. The difference between the estimated radioactivity concentration and the design value was 3.6% (1~8%) on average when using the ISOCS IUE efficiency calibration method, which was closer to the design value than the efficiency calibration method using ISOCS. In other words, the estimated radioactivity concentration using the optimized efficiency curve was similar to the designed radioactivity concentration. The results of this study can be utilized as the main basis for the development of regulatory technologies for the treatment and disposal of waste generated during the operation, maintenance, and facility replacement of domestic byproduct generation facilities.

• 기술혁신연구
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• 제12권1호
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• pp.25-48
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• 2004

The relative efficiency of loan projects of information technology promotion fund is measured using Data Envelopment Analysis. Information technology promotion project is supervised by the Ministry of Information and Communication and is managed by the Institute of Information Technology Assessment. Among all the projects of information technology supported by this fund, this study deals with the themes that have been completed from 2000 to 2002. With multiple input and output data including the amount of fund, the period of study, the rate of increase in revenue, the increase in the amount of export and the increase in the number of patent, the relative efficiency scores of all the 119 subjects were calculated in CCR and BCC models of DEA. From the reference sets of some inefficient Decision Making Units, the causes of their inefficiency were analyzed. To compare the relative efficiencies among various DMUs, Super-Efficiency Ranking Method and Logistic Regression Model were used. As the result of this study, it was shown that W promotion funds in the fields related to mobile technology, visual equipment and communication device were used most efficiently.

• 한국가시화정보학회지
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• 제9권1호
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• pp.20-28
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• 2011

An experimental assessment has been made of the drag reducing efficiency of the outer-layer vertical blades, which were first devised by Hutchins. The drag reduction efficiency of the blades was reported to reach as much as 30%. However, the drag reduction efficiency was quantified only in terms of the reduction in the local skin-friction coefficient. In the present study, a series of drag force measurements in towing tank has been performed toward the assessments of the total drag reduction efficiency of the outer-layer vertical blades. A maximum 9.6% of reduction of total drag was achieved. The scale of blade geometry is found to be weakly correlated with outer variable of boundary layer. In addition, detailed flow field measurements have been performed using 2-D time resolved PIV with a view to enabling the identification of drag reduction mechanism.

• 설비공학논문집
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• 제24권11호
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• pp.806-812
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• 2012

Air curtains are widely used in commercial and public buildings to replace solid doors where traffic of people is predicted. At doorways where the solid door is open continuously or intermittently, an air curtain may be installed in order to reduce the flow of heat and moisture from the enclosed space to the outside. The purpose of this paper is to predict isolation performance of the single-sided air curtain when the wind is blowing. For the study, a numerical simulation is used to find the influence of various jet velocities on the efficiency of the single-sided air curtain device which is mounted at the side of the doorway. The isolation performance of the single-sided air curtain is evaluated by sealing efficiency which provides the assessment of the infiltration air ratio. According to the result of this study, the single-sided air curtain has lower sealing efficiency than downward-blowing air curtain. Therefore, for energy conservation in heating space, the single-sided air curtain is not recommended because of its low effectiveness.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.517-520
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• 2006

The Korean peninsula has a number of coastal sites where the rhythmic rising and lowering of water surface due to tides results in strong tidal current. The kinetic energy of these currents can be efficiently exploited by use of tidal current turbines. The pilot tidal current power plant is to be constructed at the Uldolmok narrow channel between J info and Haenam, Our ins next Year, and extensive coastal engineer ing research works have been carried out. This paper describes and analyzes some observation results of field test about the efficiency of Helical turbine for tidal current power plant. The efficiency of turbine, which is diameter 2.2m and height 2.5m, is evaluated meximum RPM, torque, and current velocity. The tested turbines had the maximum efficiencies of the bounds of 25 to 35% in the current velocity range between 1.4 and 2.6 m/s. This result shows that the pilot tidal current power plant needs three helical turbines with diameter 3.0m and height 3.6m to produce electric power 500kW.

• 대한토목학회논문집
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• 제28권6B호
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• pp.723-729
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• 2008

본 연구에서는 홍수지수법의 불확실성을 평가하기 위해 우리나라 강우자료의 지역빈도해석에 적합한 것으로 제안된 generalized logistic 분포형의 quantile에 대한 점근 분산식을 이용하여 성장곡선에 대한 신뢰구간을 산정하였다. 또한 지점 빈도해석과 지역빈도해석에 의한 quantile의 분산을 이용하여 빈도해석의 효율성 지표(efficiency index)를 계산하였다. 우리나라 378개 강우 관측 지점을 바탕으로 구분한 14개 동질 지역에 대해 효율성 지표를 계산한 결과 홍수지수법이 지점빈도 해석보다 불확실성이 더 작은 quantile을 추정하는 것으로 나타났다. 한 지역에 포함되는 지점 개수가 과다하지 않도록 조정하는 것이 지역빈도해석의 효율성 측면에서 나은 것으로 나타났다.