• 한국산업정보학회논문지
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• 제20권4호
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• pp.111-126
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• 2015

최근 많은 기업들이 협력을 통하여 투자비용과 위험은 분산시키고, 자원과 이익을 공유하여 경쟁력 강화를 시도하고 있다. 기업 간 공유경제는 기업 간 협력의 한 형태로 기업이 보유하고 있는 유휴자원을 공유하여 그 효용을 높이는 경제적 활동이다. 다양한 이해관계자가 참여하는 기업 간 공유경제에서는 이익의 명확한 배분 방안이 있어야 한다. 따라서 본 연구에서는 기업 간 공유경제를 위한 연합 구성시 발생하는 거래비용을 적용할 수 있는 MST(Minimal Spanning Tree) 방법, 각 참가자들이 주도하여 발생하는 거래비용의 평균, 참가자 간 발생하는 거래비용에 대하여 샤플리 밸류 적용의 3가지 방법을 제안하였다. 또한 협조적 게임이론에 근거한 이익 배분 방법인 이익 균등배분(Equal distribution of gain), 이익 비례배분(Proportional distribution of gain), 샤플리 밸류(Shapley Value)에 거래비용을 적용한 이익 배분 방안을 제시하였다.

• 동력기계공학회지
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• 제20권4호
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• pp.52-62
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• 2016

Nowadays, emissions of a vehicle are been getting by testing on a chassis dynamometer and a test modes. Also, fuel efficiency is calculated by carbon-balance method that is applying the emissions(CO, THC and $CO_2$) to the fuel calculation formular. In Korea, before 2014, the formular did not include the fuel factors (density, net heat value and carbon weight fraction), but the constants were based on the fuel properties of 2000s. So, this formular did not consider a characteristic of test fuel property that was changed when progressing fuel efficiency test. The characteristics of test fuel property which was distributed in domestic have a difference of quality depending on production regions and oil-refining facilities. Because the fuel properties are variable value during refineries, crude oils and blending contents of a bio-fuel, vehicle fuel is changed for each test. Therefore, the fuel qualities need to apply for a fuel economy test. In this paper, changing patterns of a fuel properties were reviewed during history of fuel standards. Also, the appropriateness of the methods was discussed by calculating and comparing fuel economies with the fuel factors and the constants.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2205-2216
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• 2011

Governments seek to advance public industry had planed to decreased by 50% of KORAIL management deficit in 2010, The transition to a profit in 2012. In addition. The government will not achieve the goal by 2010, management announced plans to review the case, and privatization. Office of unprofitable station and vehicle maintenance, maintenance work to make cost savings through outsourcing hed discussed how to create KORAIL advancement. April 2011 the government, "A study on th Efficiency of Conventional Railway Infrastructure Maintenance R&D Report" progresses, conventional railway infrastructure maintenance has focused attention on the field. However, the general maintenance of railway facilities without the knowledge and safety awareness, as compared to foreign railway personnel, and productivity has pointed out the contradiction. Economy and efficiency of the railway in order to pursue a public awareness and safety and professionalism is required. In this study, the conventional railway infrastructure maintenance in accordance with Facts would like to introduce efficiency measures.

• 한국자동차공학회논문집
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• 제18권1호
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• pp.8-13
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• 2010

Many vehicles have significantly under-inflated tires, primarily because drivers infrequently check their vehicles' tire pressure. When a tire is used while significantly under-inflated, its sidewalls flex more and the tire temperature increases, increasing stress and the risk of failure. In this study we evaluated tire safety and economical efficiency at various inflation pressure. For tire safety we performed FMVSS indoor durability test, measurement of rolling tire temperature, braking performance at dry/wet road condition, and rolling resistance test for economical efficiency. Results show that low pressure decreases tire durability of both speed-increase condition and load-increase condition. Heat temperature of rolling tire increases as pressure decreases and significantly under-inflated tires cause increase of vehicle's stopping distance at wet road condition. Also Under-inflation increases the rolling resistance of a tire and, correspondingly, decreases vehicle's fuel economy.

• International Journal of Automotive Technology
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• 제8권3호
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• pp.361-373
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• 2007

In previous work, an approach based on maximizing the efficiency of an internal combustion engine while ignoring the power conversion efficiency of other powertrain components, such as the electric motor and power battery or ultracapacitor, was implemented in the steady-state optimization of an internal combustion engine for hybrid electric vehicles. In this paper, a novel control algorithm was developed and successfully justified as the basis for maximal power conversion efficiency of overall powertrain components. Results indicated that fuel economy improvement by 3.9% compared with the conventional control algorithm under China urban transient-state driving-cycle conditions. In addition, using the view of the novel control algorithm, maximal power generation of the electric motor can be chosen.

• 한국태양에너지학회 논문집
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• 제34권2호
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• pp.32-43
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• 2014

This study set out to identify the importance of each factor influencing facility selection with a survey among public medical facilities under the category of public buildings and apply the importance of economy, technology and environment with the weighting factor method, thus proposing optimal application plans. The research content of each section can be summarized as follows:1) Estimated energy consumption according to the energy simulation was 65,129MWh/yr, which was 18.7% higher than that according to the calculation equation. Of the energy consumption, more than 80% was used by heating and cooling facilities and construction facilities, and 20% was used by electronics such as medical equipments and in and outdoor lighting. 2) The results of a survey on the factors influencing the importance when selecting a new and renewable energy system reveal that the upper items had a priority in economy, environment, and technology in the descending order and that the lower item shad a priority in initial investments, maintenance and repair costs=energy costs, supply reliability, energy efficiency and $CO_2$ emissions in the descending order. 3) The application alternatives were analyzed in economy, technology, and environment. As a result, a geothermal system turned out to be the most excellent one a cross all the upper and lower comparison items. Of the other systems, a solar thermal system was superior in initial investments, maintenance and repair costs, and energy efficiency, where as a photovoltaic system was superior in energy costs, supply reliability, and $CO_2$ emissions. 4) As for the mixed application ratio among economy, technology, and environment, when the percentage of a geothermal system was approximately 80% or higher in anew and renewable energy system, it was the best and most optimal application plan.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 2008년도 추계 공동 국제학술대회
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• pp.316-321
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• 2008

In the present emerging global economy, as the focus is shifted from manufacturing to service sector, the efficiency of service operations is crucial for the county's sustainable growth and development. As one of the fastest growing service sector industries in South Korea, the call center has become an inevitable part of customer service for most companies. Despite of the strategic importance of the call center, there has been no empirical study on the efficiency of call center service operations in the literature. The main purpose of this study is to evaluate the technical efficiency of call center services so as to not only identify the current status of call center service operations, but also suggest ways to improve service operations efficiency. For this purpose, we apply a non-parametric efficiency measurement method, DEA (Data Envelopment Analysis), to domestic call centers in order to compare their relative efficiency. Based on DEA evaluations, we provided specific directions for the inefficient call centers to possibly improve their operation efficiencies. It is expected that the measurement methods suggested in this study can be applied to various issues such as service KS certification, service operations management, and the productivity analysis of service personnel.

• The Journal of Asian Finance, Economics and Business
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• 제7권10호
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• pp.783-793
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• 2020

The purpose of this study is to investigate whether the ECFA impacted the efficiency of banks in China and Taiwan from 2008 to 2017. This study follows Seiford and Zhu (2002), who recommend using the standard data envelopment analysis model to measure performance by increasing the desirable outputs and decreasing the undesirables. The finding was that overall technical efficiency increased from 2012 to 2017, reaching 0.575, 0.652, 0617, 0.689, 0.701 and 0.74, respectively. This result implies bank efficiency did indeed improve after China and Taiwan signed the ECFA cooperation agreement. The study found that the mean technical efficiency was 0.8756 in China, greater than Taiwan's mean of 0.3511, implying that Chinese banks experienced a greater increase in efficiency after signing the EFCA. One possible reason explored in this study is that China's economy is currently growing at the highest rate in the world, and the banks' efficiency has benefited from greater economic growth. This suggests that cross-strait sustained negotiations to consummate an agreement on trade in the services will be a very important mission in the future. This result also provides significant evidence suggesting that not accounting for undesirable output while estimating the evolution of the model may seriously distort efficiency results.

• 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.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.165.1-165.1
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• 2010

In the past, drivers bought a fuel additives to treat a combustion chambers or injector nozzles for carbon or gum deposit at market. But, nowadays, as raised cost of fuel for a vehicle the consumers also start focusing on a function of fuel additives that increases fuel economy of one. Some fuel additive manufacturers and agents advertise that their goods make a car it's initial state. This paper shows data for 3 years that were acquired during test for registration of an additive in domestic. The data were sorted according to kind of vehicle, kind of fuel, test mode, CO, HC, NOx, PM, total emission, fuel economy and accumulated mileage. And than by using simple linear regression analysis changes according to accumulated mileage was displayed. Normal distribution and histogram of rate of increase and decrease were displayed. the analyzed data indicated that a fuel additive maintain and make a car the first state of one but can't make a car be batter than initial the one.