• 동력기계공학회지
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• 제21권6호
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• pp.46-55
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• 2017

Due to the arise of natural disasters caused by global warming, consumers have more interest in the fuel efficiency of their vehicles, and fuel efficiency became an important factor in comparing vehicles. In this market situation, methods to measure fuel efficiency has become one of the main interests of vehicle related organizations and laboratories, and the current method to measure fuel efficiency is to follow the notification established by the ministry of trade, industry and energy, ministry of environment, and the ministry of land, infrastructure and transport. In this study, we analyze the influence of vehicle fuel efficiency according to test temperature and cooling fan condition which have the possibility to cause difference in fuel efficiency. The analysis results of the influence of the fuel efficiency according to the test temperature, the difference of the fuel efficiency of the test temperature ($21{\sim}29^{\circ}C$) within the allowable range of the notification showed a maximum difference of 2.9%. Therefore, it is necessary to consider the introduction of a test method that permits only the temperature change based on the reference point as the allowable range even in the test within the allowable range. The analysis of the influence of the fuel efficiency according to the cooling method showed no significant effect, and it seems reasonable to maintain the test method of the current notification.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.282-285
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• 1997

The torque efficiency of oil hydraulic pump is an important factor for it's performance characteristics. A study on the performance test method of oil hydraulic pump is based on test standard, but there is to be desired an study for double or tandem type oil hydraulic piston pump. So in this study present a test method on the tandem pump for torque efficiency and analysis method of the results.

• 전기학회논문지
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• 제62권9호
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• pp.1223-1227
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• 2013

If the factory test efficiency and field operation efficiency of water turbine are different from each other, issues for efficiency warranty can be raised. So, This paper shows the result for comparative analysis of field operating efficiency vs plant testing efficiency of the water turbine generator installed in agricultural reservoir. The efficiency of the induction generator is analyzed by the change of rotational speed with the parameter obtained by test, the efficiency of water turbine is calculated by the change of head with the design flow. Efficiency deviation of induction generator is lower but the variation of developed power is pretty high near the rated speed and the efficiency variation of water turbine is high by the fluctuation of head for constant flow. It was found that factory test efficiency and total efficiency of water turbine generator calculated according to the rotational speed are very close.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.205.1-205.1
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• 2011

This study concerns a low head and kaplan turbine efficiency measurement using the acoustic scintillation flow meter(ASFM). The ASFM is one of absolute discharge measurement methods because it measures velocity-area of discharge with couples of transducers. This study shows that the highest efficiency of turbine is 87.7% and the efficiency is 85.8% in the rated output(600kW). The test result is reliable because the efficiency trend from this test is similar to the result of index test conducted in 1986. In this paper, the principle, measurement methods, application and test procedures of the test are discussed.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.506-511
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• 1998

In this paper we consider multiobjective linear programming problems with coefficients of the objective functions specified by possibility distributions. Possibly and necessarily efficient solution sets are defined as funny solution sets whose membership grades represent possibility and necessity degrees to which a feasible solution is efficient. Considering efficiency condition and its dual condition in ordinary multiobjective linear programming problem, we propose efficiency test methods based on an extreme ray generation method. Since the proposed methods can be put in the part of a bi-section method, we can develop calculation and methods of the degree of possible and necessary efficiency for feasible solutions.

• Journal of the Korean Statistical Society
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• 제26권4호
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• pp.467-476
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• 1997

The two-sample t-test is not expected to be optimal when the two samples are not drawn from normal populations. According to Box and Cox (1964), the transformation is estimated to enhance the normality of the tranformed data. We investigate the asymptotic relative efficiency of the ordinary t-test versus t-test applied transformation introduced by Yeo and Johnson (1997) under Pitman local alternatives. The theoretical and simulation studies show that two-sample t-test using transformed date gives higher power than ordinary t-test for location-shift models.

• 전기학회논문지
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• 제63권4호
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• pp.461-468
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• 2014

An efficiency test for generators is generally required in case of construction of a new power plant or replacement of an existing generator. Generally, the efficiency of generator is measured by the input-output ratio under any given condition. Therefore, the best way is to directly measure the value of input and output power of a generator and calculate the efficiency values. However, it is difficult to measure a generator's input values accurately, especially for large systems. So, we are usually measuring the losses of the generator. But for measuring these values, there are several constraints for test such as preparing additional power generator and releasing the protection relay for manual operation of auxiliary equipments. Therefore, this study suggests that a novel generator efficient test method using the shaft-torque method which can be carried out while the generator is normally operating. The reliability of the result value was verified by comparing with the efficiency test results of the conventional retardation method on IEEE Std 115-1995.

• The Journal of Asian Finance, Economics and Business
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• 제8권1호
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• pp.751-758
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• 2021

This research is conducted to measure the efficiency level of Islamic banking in Indonesia and also to analyze the factors that can affect its efficiency level. This research used a purposive sampling technique to determine the sample size that will be used, with criteria that the bank has been operating since 2010 and consistently published its financial reports during the research period from 2011 until 2019; therefore, the total sample obtained was 11 samples. Analysis for efficiency level is done by using linear programming Stochastic Frontier Analysis (SFA), with test tool in the form of Frontier 4.1 and Eviews9 to find out what factors that affect efficiency. Efficiency test is done by involving input and output, while influence test used bank-specific variables comprising bank size, bank financial ratio, and macro-economy variable. Research result shows that there are only two banks that are almost close to being fully efficient firms, but the result still does not indicate that Islamic bank works efficiently. Results of the influence test show that factors affecting Islamic banking efficiency in Indonesia are bank size, Capital Adequacy Ratio (CAR), Non-Performing Finance (NPF), and Financing to Deposit Ratio (FDR), while other factors are not influential over the study period.

• 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.

• 한국분무공학회지
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• 제29권1호
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• pp.1-6
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• 2024

This paper is a numerical analysis study for evaluating the energy efficiency of electric vehicles. Currently, the methods for testing and evaluating the energy consumption efficiency of electric vehicles have limitations such as resources and time. Therefore, there is a need for research on developing models to predict the energy consumption efficiency of electric vehicles. In this study, a numerical analysis research is conducted to predict the energy efficiency of electric vehicles using a vehicle dynamics numerical analysis model. To validate the accuracy of the simulation model, it is compared the results of dynamometer tests with the simulation results and used the Unified Diagnostic Services (UDS) protocol to acquire internal data from the electric vehicle. It is ensured the reliability of the simulation model by comparing data such as motor speed, battery voltage, current, state of charge (SOC), regenerative braking power generation, and total driving distance of the test vehicle with dynamometer test data and simulation model results.