• 기술경영경제학회:학술대회논문집
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• 기술경영경제학회 2002년도 제20회 동계학술발표회 논문집
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• pp.59-89
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• 2002

The rapid diffusion of information and telecommunication (IT) technologies during the recent decennia produced fundamental changes in the economic activity at a global level, resulting in what became coined as the "new economy". However, empirical evidence on the contribution of IT equipment to growth and productivity is at best mixed, with the more or less consistent results on the positive link between the two relating to the United States in the 1990-s. Although the empirical literature on the link between IT investment and economic performance employs a wide variety of methodologies, the overwhelming majority of the studies appears to be employing the assumption of linearity of the IT-performance relationship and predominantly explores the direct nature thereof. In this study we relax both these assumptions and find that the indirect, or aggregate productive efficiency, effects of IT investment are as important as are the direct ones The estimated non-linear nature of the indirect relationship between IT investment intensity and productive efficiency accommodates the concepts of critical mass and complementary (infrastructure) capital offered in the literature. Our key finding is that the world economy′s average level of IT investment intensity remained below the estimated critical mass. Since in this study we developed a methodology that allows one to explicitly measure the critical mass of IT investment intensity, its individual estimation at a country or industrialsector level may help evaluate the extent to which IT investment activity has to be encouraged or discouraged.

• 디지털융복합연구
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• 제14권7호
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• pp.57-72
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• 2016

최근 소비자들 개인이 가지고 있는 자원을 공유함으로써 자원의 효율성을 향상시키고, 개인의 욕구를 충족시키기 위한 방향으로 소비가 변모하게 되면서 공유경제 서비스가 확대되고 있다. 이에 본 연구는 공유경제 서비스가 가지고 있는 특징을 고려하여 실증적 분석모형을 개발하고, 공유경제의 이용의도에 영향을 미치는 요인들에 대한 분석 및 공유경제 서비스의 차별성을 반영하기 위하여 기술수용모형에 가격민감성과 신뢰성을 추가하고, 지각된 즐거움을 포함하여 확장된 기술수용모형을 활용한 연구를 수행하였다. 분석결과, 가격민감도, 자기효능감, 기술혁신성, 신뢰성, 지각된 유용성, 사용용이성, 지각된 즐거움 및 이용의도는 각각 서로 다른 방식으로 영향을 미치는 것으로 나타났다. 본 연구를 통해 공유경제 서비스의 이용의도를 명확하게 파악할 수 있었으며, 소비자에게 이용의도 확대를 위한 시사점을 제공할 수 있었다.

• International Journal of Automotive Technology
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• 제7권4호
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• pp.459-468
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• 2006

The objective of this paper is the development of the forward-looking dynamic simulation model of a hybrid electric vehicle(HEV) for a fuel economy study. The specification of the vehicle is determined based on two factors, engine peak power to curb weight ratio and specific engine power. The steady state efficiency models of the powertrain components are explained in detail. These include a spark ignition direct injection(SIDI) engine, an integrated starter alternator(ISA), and an infinitely variable transmission(IVT). The paper describes the integration of these models into a forward facing dynamic simulation diagram using the AMESim environment. Appropriate vehicle and driver models have been added and described. The controller was designed in Simulink and was combined with the physical powertrain model by the co-simulation interface. Finally, the simulation results of the HEV are compared with those of a baseline vehicle in order to demonstrate the fuel economy potential. Results for the vehicle speed error and the fuel economy over standard driving cycles are illustrated.

• 융복합기술연구소 논문집
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• 제5권1호
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• pp.23-26
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• 2015

The purpose of present study is to analysis the Characteristics of fuel economy and Green house gases due to the driving mode conditions of The hybrid electric vehicle(HEV). HEVs are divided into mild and power types according to the their functions. mild type HEVs are inexpensive because they do not need to implement a pure electric mode. Power type HEVs are more expensive but has also better fuel efficiency. In the present paper, the test results for the gasoline vehicle using FTP-75 mode and HWFET are present.

• 한국항만경제학회지
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• 제24권4호
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• pp.47-70
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• 2008

본 연구의 목적은 확률적 생산변경함수를 이용하여 총요소생산성 성장을 도출하고 그 내부요소를 기술효율성 변화, 기술진보, 규모효율변화, 배분적 효율변화로 구분하여 생산성 성장의 요인을 파악해 보고자 함이다. 1990-2003년간 항만물류산업의 총요소생산성 증가율은 연간 0.019 (1.9%)로서 전산업의 증가율 0.010보다 높다. 그 내부의 주된 기여요인은 기술진보이고 기술효율성변화는 감소하였다. 총요소생산성의 주된 기여요인으로는 항만산업은 배분효율성, 해운산업은 기술진보, 수송장비산업은 규모효율변화를 들 수 있다. 총요소생산성 변화는 1990년대 후반이후에 감소하는 추이를 보였다. 항만물류산업은 전산업에 비하여 매우 낮은 수준의 기술효율성수준을 보여주고 있고 산출탄력성 관점에서는 1990-2003년간 자본의 탄력성(0.391)이 노동의 탄력성(0.227)보다 높지만 규모에 대한 보수는 0.618로서 최적규모에 상당히 벗어나 있다.

• 산업경영시스템학회지
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• 제40권4호
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• pp.21-28
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• 2017

Improving efficiency of the telecommunication is crucial to the development and growth of Korean economy. Recently, it has become important with the huge development of information technology and its greater potential for extensive impact on the rest of the economy. Hence, it is useful to determine the factors that help enhance efficiency in telecommunication and consider them in improving the evaluation model. This study applies DEA (data envelopment analysis) to evaluate the relative efficiency of 51 branches of a Korean telecommunication company. Using the super-efficiency approach, we tested outliers which may affect the results and ranked the efficient branches. A method of deriving key variables applied to business operation is proposed to identify the key performance indicators for evaluation that takes environmental (non-discretionary) factors into account. We used the extended CCR model proposed by Banker and Morey to investigate the influence of non-discretionary factor. The information provided by the model (slacks, weights) and the sensitivity analysis shows that the most important indicator that affects the branch performance is operating cost. The results of sensitivity analysis show that average efficient score decreases from 0.972 (base case) to 0.863 for CASE2-COST. The average score of the data proves the priority of operating cost over other indicators. The effect of environmental (non-discretionary) variable was found to be significant. The population effect was positive and improved overall efficiency by 0.91% on average. Non-discretionary factor plays a meaningful role explaining the performance of branches. The performance optimization report can help a manager of an inefficient branch to develop branch strategies. Managers can identify the top-performing units, study best practices and adopt the strategy to the organization.

• 경영과학
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• 제32권3호
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• pp.37-54
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• 2015

This paper suggests energy efficiency which can be the foundation on corporate profit and effective energy management following by change of global climate and of energy-related regulations. Using comparable financial information and information related to energy use, an DEA (Data Envelopment Analysis) model has been used to identify energy efficiency with DMU (Decision Making Unit)s which are companies subjected to reduce greenhouse gas emission in 2009. Through this research, different from existing researches, environmental variables which can influence on energy efficiency are identified. The results show as follows. First, most of companies follow IRS, which means scale of economy exists among units so that they have more opportunity to increase efficiency by increasing scale of inputs. Second, this research identified that depending on the difference of environmental characters such as the emission structure and the size of companies, energy efficiency of the companies turns out differently.

• 유통과학연구
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• 제15권12호
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• pp.73-84
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• 2017

Purpose - Over recent years, O2O and shared economy have been an eye-catching topic. Many researches on O2O and shared economy have been published gradually. The emerging enterprise of chauffeured car services developed rapidly in the past two years. Therefore, it is necessary to explore the influencing factors of use intention of the chauffeured car services users. Through active use of O2O and shared economy, put up with operation strategy in line with their use intention. Research design, data, and methodology - After collecting 324 respondents in China with questionnaires, this study begin the empirical research with users of Chauffeured Car Services, and analyzes data with IBM SPSS 24.0 and IBM AMOS 24.0. Results - Personal Propensity to Trust significantly affects the Initial Trust of chauffeured car services users. Firm Reputation significantly affects the Initial Trust and use intention of chauffeured car services users. Initial Trust significantly affects the use intention of chauffeured car services users. Performance Expectancy and Effort Expectancy significantly affect chauffeured car services users' use intention. Social Influence also significantly affects the use intention of chauffeured car services users. Conclusions - First, Initial Trust significantly affects the use intention of chauffeured car services users. Thus, the enterprise should make efforts to improve users' initial trust in order to attract their attention. For this reason, chauffeured car services enterprises should conduct questionnaires to deeply explore what needs can improve users' initial trust. Second, performance expectancy and effort expectancy significantly affect chauffeured car services users' use intention. When users enjoy chauffeured car services, they attach great importance to the convenience, simplicity and efficiency, which reflects that chauffeured car services' desire for greater development in the O2O and shared economy market. Therefore, they need to grasp users' needs (convenience, simplicity and efficiency) and carefully improve the quality of chauffeured car services. Finally, social influence also significantly affects the use intention of chauffeured car services users. It means friend recommendation or mass media influences users' intention. So, it is more important to increase differentiated benefits, advertising and publicity of chauffeured car services.

• 한국자동차공학회논문집
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• 제25권2호
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• pp.207-218
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• 2017

Improving fuel consumption, particularly that of commercial vehicles, has become a global concern. The reduction in logistics cost has been a key issue in efforts to improve fuel economy and efficiency of transportation equipment. Typical technologies for reducing reduce fuel usage include air resistance reduction technologies, tire rolling resistance technologies, and idle technologies among others. Air resistance technology is a highly effective method that can be easily applied in a short period. As with air resistance technology, several devices involving side skirt, boat tail and gap fairing have been developed based on an analytical 3-D modeling technique for reducing air resistance attributed to the vehicle configuration. The devices were on a 45 feet tractor-trailer and the emission test was done using PEMS equipment. Fuel economy was evaluated by introducing several devices to reduce outer air resistance. The test was conducted by changing the experimental method of SAE J1321 Joint TMC/SAE Fuel Consumption Test Procedure - Type II test. As a result, air resistance decreased by at least 15 % and fuel economy improved by at least 13 %. This study sought to reduce greenhouse gas and improve fuel economy by applying several devices to a test vehicle to lower air resistance.

• 한국항만경제학회지
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• 제26권3호
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• pp.165-174
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• 2010

본 논문의 DMU는 9개 지역(부산, 경북, 인천, 경기, 전남, 경남, 전북, 울산)이며, 이 지역들의 경제활동인구, 총고정자본형성, 항만수출액을 투입요소로, 총부가가치액을 산출물로 선정하였다. 그리고 본 논문에서는 항만수출액을 포함하지 않은 경우와 항만수출액을 포함한 경우의 효율성과 생산성을 비교 분석하였다. 분석결과를 요약하면 다음과 같다. 첫째, 항만수출액을 포함시킨 경우가 그렇지 않은 경우에 비해 효율성이 증가하였다. 그룹 2의 경우는 그룹 1에 비해 초효율성 값이 커졌으나 2000년 이래로 꾸준히 그 값이 작아지고 있다. 이것은 효율성을 100% 유지하기 위해서 투입요소를 거의 늘일 여유가 없게 된 것을 의미한다. 둘째, 그룹1에서 생산성 지수가 1를 하회한 지역은 경남과 전북으로 나타났다. 그룹2에서 생산성 지수가 1를 상회한 지역은 부산, 경북, 충남으로 나타났다. 셋째, 그룹1에서 LDP로 측정해 보면 인천이 9년간 효율성의 변화가 가장 작았고, 충남의 경우가 효율성의 변화가 가장 큰 것으로 나타났다. 반면에 그룹2에서 LDP로 보았을 때는 충남이 9년간 효율성의 변화가 가장 작았고, 전남의 경우가 효율성의 변화가 가장 큰 것으로 나타났다.