• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.3
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• pp.79-84
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• 2007

Recently it is strongly required to develop the better fuel economy as well as basic power performance based on strict emission legislation. This paper focuses on studies of the engine cooling and ancillaries system among fuel economy factors in the developing stage. Firstly through the analysis of the current specifications, it is assessed whether each components may be designed properly, not overdesigned. Secondly, it is predicted how the fuel economy of each components can be improved. Finally the results are confirmed by vehicle field test equppted with the updatedcomponents. This study found good agreementbetween the prediction and the field test on the vehicle fuel economy improvements of the heavy duty engine vehicle with updated components such as engine cooling and ancilliaries.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.2
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• pp.1-15
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• 1995

The driving patterns in Seoul metropolitan area were surveyed in an experiment involving 1,212km of driving along seventeen representative routes. The speed and fuel consumption data were recorded and the influence of driving patterns on vehicle fuel economy was analyzed by statistical techniques. The results showed that characteristics of driving in Seoul metropolitan area are far different from that of CVS-75 mode and then on-road fuel economy in Seoul may be small as compared with that of CVS-75 mode. Finally, it was proposed that CVS-75 mode fuel economy should be modified by applying adjustment factor to represent actual on-road fuel economy.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.44-48
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• 2008

This paper describes on studies of the heavy duty engine calibration for better fuel economy based on real driving conditions. Using testbed validated software simulation of the engine and turbocharger system, an alternative turbocharger specification, with potential to improve fuel economy was identified. Secondly, the engine calibration was modified to optimize vehicle fuel economy over a typical customer drive cycle whilst still meeting the steady-state (testbed) emissions legislation. These results were confirmed by field testing of a vehicle equipped with the updated specifications. This study found good agreements between the prediction and the field test on the vehicle fuel economy improvements of the express bus with updated calibration and turbocharger.

• Tribology and Lubricants
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• v.21 no.3
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• pp.142-148
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• 2005

In order to improve the fuel economy by design change of automatic transmission, various technologies such as increased shift stages, slip control of lock-up clutch and compact and low-weight design have been developed. And also many OEMs have developed their own ATFs as a part of these automatic transmissions. In this study, to investigate the effects of ATF characteristics on fuel economy, we got the worldwide OEM ATFs and made some reference fluids. And physical properties, frictional characteristics and fuel economy using dynamometer test for these fluids were evaluated. From the investigation, it was found that viscosities of ATFs are correlated with fuel economy in dynamometer test and reducing the viscosities made it possible to obtain fuel economy.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.11a
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• pp.155-161
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• 2000

To improve the vehicle fuel economy, various technologies such as improvement of power train efficiency, use of light weight material, improvement of aerodynamic design, have been studied. One of the possible way to improve the vehicle fuel economy is to reduce the engine friction loss by improving the engine oil characteristics. In the present paper, it was examined the effect of the engine oil viscosity and the addition of friction modifier to engine oil on vehicle fuel economy improvements. Moreover, the effect of engine oil degradation on vehicle fuel economy was examined with two gasoline vehicles and one diesel vehicle by using the fuel economy test facility.

• International Journal of Computer Science & Network Security
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• v.22 no.2
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• pp.297-303
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• 2022

The main purpose of the study is to determine the main aspects of the problem of socio-economic development in the conditions of the digital economy. The post-industrial era is characterized by the development of the electronic environment and the transition to an information civilization. In this regard, the developed countries of the world pay considerable attention to the development of the digital economy. However, there are a significant number of problems associated with this process. The country cannot be successful in the development of the digital economy in the absence of the necessary legal framework, an economic development strategy based on digital technologies. The research methodology involves the use of several theoretical methods for analyzing and synthesizing information. As a result of the study, the key problems of socio-economic development in the digital economy were characterized.

• ETRI Journal
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• v.15 no.2
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• pp.69-74
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• 1993

The consumer surplus under the open economy is greater than that under the closed economy from the viewpoint of social welfare. This indication has been proved when only the product market is considered. This article is to show how this result is changed if the R&D market as well as the product market is considered. We find the possibility that the closed economy is preferred to the open economy in case of the (international) R&D joint venture.

• 한국디지털정책학회:학술대회논문집
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• 2004.05a
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• pp.37-49
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• 2004

According as the use of information and communication technologies and the Internet are advancing rapidly, the digital economy are no longer emerging or beginning today. They are here with ours already. We are living in a new era that the economic paradigm and structures are changed remarkably, namely the digital economy era. Tourism policy is crucial to tourism industry competitiveness by triggering changes in the digital economy. Better tourism policy in the digital economy should satisfy the tourist needs as well as create additional value for the tourism industry.

• The Journal of Industrial Distribution & Business
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• v.10 no.1
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• pp.39-49
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• 2019

Purpose - Previous studies examined effects of sharing economy in the fields such as accommodation and automobile sector, while there are lack of researches in the field of skill-sharing economy. By classifying skill-sharing into general and special skill-sharing, this study explored effects of variables such as transaction utility, social utility, sustainability utility, emotional utility, economic utility, and trust utility, on attitudes, intention, satisfaction, and loyalty of demand (i.e., customers) and supply (i.e., providers) sides, potential, and actual customers. Research design, data, and methodology - Data were collected via both online and offline surveys. This study applied factor analysis and multiple regression analysis for findings. Results - Results show that utilities for general suppliers' skill-sharing are significant than other cases. Among utilities, this study found that trust utility shows significant for the cases of special customers', general suppliers' and special suppliers' potential skill-sharing. The results implies that trust is crucial in the transaction of the sharing economy. Conclusions - Enhanced managerial systems help resolve issues on the sharing economy. This study provides implications what are positive effects of skill-sharing economy and recommends proper establishment of the sharing economy.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.5
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• pp.73-80
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• 2020

Tax is the main revenue of Government, so fighting tax evasion and sustainable growth have been the primary macroeconomic goals being pursued by every developing country, Vietnam included. The existence and development of the shadow economic sector are synonymous with the national budget losing out. In Vietnam, foreign direct investment projects do not promote economic growth and is also a sector that gives way to tax evasion.The purpose of this study is to investigate the impact of foreign direct investment, the quality of the informal institution on the size of the shadow economy in Vietnam, during the period 1991-2015. By applying the Autoregressive Distributed Lag approach and Toda and Yamamoto test, we found evidence to conclude that the quality of the informal institution harms the size of the shadow economy. The results of the causality test show that there is a unidirectional causality running from the shadow economy and the quality of the informal institution to foreign direct investment attraction in Vietnam. Political solutions need to be implemented carefully to counter the harmful effects of the shadow economy. Policymakers should adopt several economic policies to improve the 'human capital' and drive the shadow economy into the formal economy.