• Journal of Korean Institute of Industrial Engineers
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• v.4 no.2
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• pp.107-118
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• 1978

The paper illustrates a possible application of control theory to an economic growth system. Simultaneous nonlinear system of differential equations has been modeled which is different from the traditional formulation, based on the theory of economic growth for a two-sector (dual) economy. Necessary and sufficient conditions for the existence of the optimal control are derived directly from the Hamiltonian, and the optimal controls are also obtained by solving simultaneous equations. Obtaining the trajectories of the optimal control and state variables, however, should rely on the numerical procedures. Empirical application has been conducted for the case of the Korean economy as an illustration.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.3
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• pp.74-80
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• 2009

The objective of this paper was to investigate the slip rate and the slip frequency number of damper clutch of torque converter in 2.4L passenger vehicle with 5-speed A/T and analyze the effect of slip control and control strategy on driving characteristics and the fuel economy. The newly developed torque converter with the more durable wet friction material and the slip-controlled damper clutch system, the DCC system, was installed, which was easily compatible and amendable of the lock-up clutch of the base system. The vehicle has been tested on the fuel economy modes such as FTP-75, HWFET and NEDC (ECE15+EUDC) driving cycle at chassis dynamometer. The DCC mode (II), of which the control strategy had both the lock-up and the slip-controlled clutch, and the DCC mode (I) with full slip-controlled clutch were compared with the base system with only the lock-up clutch. As the research result, comparison to base system, the fuel consumption of the vehicle with the DCC control (II) was effectively improved by 6.6% and 7.7% on FTP-75 and NEDC mode.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.6
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• pp.908-912
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• 2013

Because of their longer operating times and larger size relative to conventional fans, the cooling fans mounted in buses consume larger amounts of energy. Most of the cooling fans mounted in a bus are connected to the engine by a viscous clutch. A viscous cooling fan's speed is determined by its fluid temperature, which is affected by the air flow through the radiator. The fan does not react immediately to the coolant temperature and in doing so causes unnecessary energy consumption. Therefore, the fuel economy of buses using viscous fans can be improved by changing to an electric cooling fan design, which can be actively controlled. In addition, electric power consumption is increased by using electric cooling fans. Thus, when electric fans are applied in conjunction with the alternator management system (AMS), the fuel economy is further enhanced. In this study, simulations were performed to predict coolant temperature and cooling fan speeds. Simulations were performed for both viscous and electric cooling fans, and power consumption was calculated. Additionally, fuel economy was calculated applying both the alternator management system and the electric cooling fan.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.1
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• pp.71-76
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• 2014

This Research focuses on how to maximize fuel economy improvement of I.S.G. while keeping 12V system. With 12V system the maximum gain of fuel economy with I.S.G. is known to be about 3~5% in FTP-75 mode because engine stop is only conducted in standstill idle. But in this study deceleration engine stop (engine speed is zero) has been tried additionally and the optimum condition for deceleration engine stop was found to maximize fuel economy improvement in practical point of view, the result of which is about 8.8% in FTP-75.

• International Journal of Advanced Culture Technology
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• v.9 no.3
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• pp.152-159
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• 2021

Small local businesses such as corner shops and street markets have been severely impacted by the COVID-19 pandemic and declining consumption. A community currency is a local currency that can be used to exchange for one of the local currencies within an online community. Community currencies can be effective not only in supporting small businesses, but also in helping the local economy more vibrant, benefiting consumers in the community. An important goal of Community Currency is to foster a vibrant local economy by building mutually beneficial relationships between local business owners and customers. The purpose of this study was to identify how the existing community currencies of participating SMEs and self-employed in Seoul and Gyeonggi-do metropolitan areas contributed to commercial revitalization by category and to suggest a new or better approach to community currency operation. It also focused on presenting the best solutions for the future direction of mobile community currencies, measures that are better than current currency operations, revitalize the community and develop the economy.

• International Journal of Computer Science & Network Security
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• v.23 no.10
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• pp.21-29
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• 2023

Recently there has been an increase in interest and competition in sharing economy platforms. The success stories of many companies have spread in this field, such as Uber, but on the other hand, there are many other companies that have failed. We studied and analyzed the factors that affect the user's participation in the sharing economy platforms as an essential part of this system, and how to maintain the consumer's intention of use without compromising consumer satisfaction, as it has become an issue of great importance on the path to the success of the sharing platforms. Relying on the expanded valence framework and expectation confirmation theory as a basis, we constructed hypotheses that influence intention to participate in participatory platforms. Results show that system quality, trust, perceived benefits, and satisfaction are important factors that positively influence intention to continue to participate. This research is expected to help researchers move forward with research related to the future and help business managers understand user insights and integrate them with their business model to help the success, development and expansion of their business in the Kingdom of Saudi Arabia.

• Journal of Korean Institute of Industrial Engineers
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• v.8 no.1
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• pp.40-60
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• 1982

Since the first oil embargo (1973), there have been developed many different types of energy-economy interaction models based upon various aspects of energy impact mechanism. We will propose to develop an integrated energy-economy interaction analysis system for less developed countries' energy policy analysis, especially for investment analysis toward constructing energy-saving industry infrastructure ; which is based on the motivation of combined energy models by John P. Weyant. This modeling system can cover the economic growth, inter-industry transactions including production features, and process analysis of energy sector in the total network scheme of general equilibrium, so that it can give many political implications as well as the modeling concept to be used for analyzing various political issues and making decisions related to national energy environment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.11a
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• pp.33.2-42
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• 2000

This study probes the necessity of establishing a logistic free zone in Port of Busan. It considers the economic effects of establishing the logistic free zone of Busan Port, and suggests policy prescriptions for introducing the free zone system and improving the logistics functions of Busan Port. Using input-output table data, the regression analysis was able to provide a quantitative prediction on effects of making the Busan Port a tariff-free zone. Influence for the regional economy due to the enforcement of the free zone system this research found that a strong positive effects should be expected on the Busan regional economy once the logistic free zone would be set up at the Port of Busan. The positive economic effects on Busan regional industries might be further strengthened if the value-added logistics function of Busan Port could be supplemented by linking to the hinterland of Busan Port.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.4
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• pp.41-49
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• 2007

This study aims to examine the ripple effect of the '119 Integrated Information System' for city disaster management on the local economy. The study was conducted in the area of Gyeongnam province, and the study method is the interdependence analysis based on the Input Coefficient drawn from Input-Output Tables in which Intermediary Transaction Tables drawn through RAS was taken advantage of to grasp the correlation among industries and regions in terms of the local economy, and the ripple effect of the changes of political exogenous variables on the local economy was divided to such elements as production, added value, and employment so as to attempt empirical analysis on the local economy system. To estimate the ripple effect on the local economy, three different amounts of the expected input were applied to the study respectively and the results are as follows: Some $28.7{\sim}42.4$ billion won for the production induction effect, some $7.5{\sim}11.4$ billion won for the added-value induction effect, some $103{\sim}157$ job openings for the employment induction effect, and some $3.8{\sim}5.7$ billion won for the income induction effect are expected to take place as the ripple effect on the local economy.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.27 no.3
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• pp.75-98
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• 2016

The sharing economy has been evaluated as a sustainable system dominating the next 10 years and one of the 10 ideas which can change the world. The purpose of this study is to reveal whether there is any relevance between the sharing economy and libraries, if the library can be the core model of the sharing economy, and to propose how libraries could contribute to a sharing economy. To this end, literature related to the sharing economy and the actual cases of its implementation were analyzed. The results are as follows: First, the library was evaluated as a successful model of the sharing economy because it has shared information and tools for centuries. Therefore, it was concluded that the library could be an institution that can lead to a sharing economy. Second, it was analyzed that the library could foster the sharing economy through offering its space, and functioning as the infinite imagination room and smart work center, sharing goods through Little Free Libraries, as well as various other resources of library, and sharing various types of knowledge including reference services. Third, it can be said that the possibility of realizing a shared economy in libraries is inexhaustible, and librarians can play an active role and will positively influence the success or failure in terms of realizing the sharing economy. In the future, there needs to be a study to measure the practices and the performance of the sharing economy of libraries.