• Journal of Navigation and Port Research
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• v.48 no.2
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• pp.104-108
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• 2024

This study investigates the relationship between national controlling fleets and the managerial performance of ship management companies in Korea. As industries clearly show interrelations between upstream and downstream entities , it is likely that the managerial performance of ship management companies in Korea is affected by the size of national fleet. Therefore, the present study analyzes the impact of Korean fleet size on the growth and the profitability of ship management firms. To this end, the performances of 10 major ship management companies in the period from 2012-2022 are examined through panel data regressions. The results indicate that the size of the national fleet has a positive impact on growth in both the assets and the sales of ship management companies. Specifically, the size of the Korean-flagged fleet is the most crucial factor, while that of the foreign-flagged fleet has no significant effect. In stark contrast to the findings regarding growth, the size of national fleet is found to have no significant impact on the profitability of ship management companies. This study's findings are expected to provide valuable implications informing both the managerial decision-making of ship management companies as well as policy-making for shipping and its related industries.

• Journal of Korea Multimedia Society
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• v.19 no.3
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• pp.573-584
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• 2016

Recent application range of sensor networks is becoming diverse. It means collected sensor data types are becoming diverse too. These sensor data have their own characteristics. Thus achieving energy efficiency, existing sensor network management policy consider their own characteristics. However, it is inefficient to apply the existing network management schemes for controlling such kind of data at the same time. Because, existing network management schemes considered one type of data only. Therefore, we propose a novel routing scheme that is able to efficient energy conservation through effective data controlling on multi-sensor application environment.

• Journal of the military operations research society of Korea
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• v.17 no.1
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• pp.61-83
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• 1991

There has been a great deal of research dealing with the optimal replacement of stochastically deteriorating equipment and research in queueing systems with a finite calling population. However. there has been a lack of research which combines these two areas to deal with optimal replacement for a fixed number of machines and a limited number of repairmen. In this research, an optimal control policy for replacement involving two machines and one repairman is developed by investigating a class of age replacement policies in the context of controlling a G/M/1 queueing system with a finite calling population. The control policy to be imposed on this problem is an age-dependent control policy, described by the control limit $t^{\ast}$. The control limit is operational only when the repairman is idle; that is. if both machines are working, as soon as a machine reaches the age $t^{\ast}$ it is taken out of service for replacememt. We obtain the ${\epsilon}$-optimal control age which will minimize the long-run average system cost. An algorithm is developed that is applicable to general failure time distributions and cost functions. The algorithm does not require the condition of unimodality for implementation.

• The Journal of Korea Robotics Society
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• v.16 no.2
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• pp.137-146
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• 2021

When controlling manipulator, degree of freedom is lost in singularity so specific joint velocity does not propagate to the end effector. In addition, control problem occurs because jacobian inverse matrix can not be calculated. To avoid singularity, we apply Deep Deterministic Policy Gradient(DDPG), algorithm of reinforcement learning that rewards behavior according to actions then determines high-reward actions in simulation. DDPG uses off-policy that uses 𝝐-greedy policy for selecting action of current time step and greed policy for the next step. In the simulation, learning is given by negative reward when moving near singulairty, and positive reward when moving away from the singularity and moving to target point. The reward equation consists of distance to target point and singularity, manipulability, and arrival flag. Dual arm manipulators hold long rod at the same time and conduct experiments to avoid singularity by simulated path. In the learning process, if object to be avoided is set as a space rather than point, it is expected that avoidance of obstacles will be possible in future research.

• Journal of Society of Preventive Korean Medicine
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• v.8 no.2
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• pp.1-12
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• 2004

This paper estimated the demand and supply of physicians for oriental medicine for the period of $2009{\sim}2019$. Two equation models were used in the estimation of manpower. In 2004, the total number of physicians of oriental medicine was amounted to 13,662 registered and 10,532 available in clinical practice, respectively. According to estimates in the study, overall excess supply of physician manpower in oriental medicine was expected in the period, such as $5,300{\sim}5,700$ persons in 2009 and $900{\sim}1,700$ persons in 2019. However, the excess supply would be mitigated after 2019 mainly due to an increase in demand for oriental medical services. Specially, opening medical service market to overseas could be an exogenous variable in physician supply. An alternative manpower policy for oriental medical doctors is needed in a way of controlling oversupply.

• Health Policy and Management
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• v.10 no.4
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• pp.20-56
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• 2000

The purpose of this article was to evaluate the effects of reimbursement system on the basis of diagnosis-related groups(DRGs). We searched articles which was published from 1970 to 2000 using MEDLINE ； Key words "diagnosis-related groups, DRGs, prospective payment system, PPS. Then we reviewed 97 articles on classifying them into several categories of contents. It seems that the effects of DRGs in controlling hospitals cost in the U.S. was not clear cut. The U.S. Medicare PPS using DRGs remains vulnerable to compensatory increases in ambulatory care and long-term care facilities utilization despite cost per case and cost per admission being reduced. Also some research indicated the possibilities of deterioration in health care service quality. So putting theses results together, much more consideration is needed before the application of DRGs reimbursement system in Korea. Particularly there is the crucial difference between U.S. health care system and Korean, we must be aware of the limitations of DRGs and revise the DRG system to applicable in Korea.orea.

• Journal of Korea Water Resources Association
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• v.40 no.11
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• pp.869-876
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• 2007

This paper estimates the output and price elasticities of disaggregated industrial water in order to afford some information for improving the efficiency of government water policy. This paper uses the marginal productivity method for estimating the output and price elasticities of industrial water. The estimated output elasticity shows that the value of industrial water is much higher than the average price of industrial water and the estimated price elasticity shows that the water pricing policy is effective for controlling the demand of industrial water.

• KDI Journal of Economic Policy
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• v.44 no.3
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• pp.27-48
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• 2022

This paper reconsiders the empirical evidence of the relationship between tax treaties and FDI using U.S. outbound FDI to 78 countries over the period of 2007-2018. Unlike previous studies, we explicitly consider differences in the tax environments of recipient economies, including their tax-haven status, transfer pricing rules, CFC rules and anti-avoidance regulations, in our estimations. Our results confirm the importance of controlling for country-specific tax environments, especially the tax-haven status and transfer pricing rules. We find that tax treaties positively contribute to FDI inflows in developing countries, while they have no statistically significant impacts on OECD countries. Recently signed tax treaties still foster FDI but less than older ones do. Finally, our results indicate, all other things being equal, that the weaker the transfer pricing regulations, the greater the amount of U.S. direct investment into a non-OECD economy.

• East Asian Economic Review
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• v.27 no.2
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• pp.89-114
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• 2023

This paper empirically examines how controlling strategic goods affects productivity by focusing on Korean industries from 2015 to 2019. We hypothesize that strategic goods control positively affects productivity because it promotes international trade by making up for market failures, building up national credibility, and stabilizing market environment; in turn, international trade contributes to productivity growth. The regression results are congruent with our hypothesis. The effects of strategic goods control on productivity were positive and statistically significant in general. These positive effects were more prominent in the group of industries that include strategic goods and, thus, are technologically intensive. The results also support that international trade is a key medium for the effects of strategic goods control on productivity. Consequently, our empirical results support government policy on strategic goods control, ensuring that strategic goods control can contribute to economic growth by reducing diplomatic friction and stabilizing the global market.

• Journal of Korean Library and Information Science Society
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• v.47 no.3
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• pp.213-239
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• 2016

As Open Data has been emphasized globally, discussions on data policies have occurred for minimizing problems resulting from data sharing and reuse. This study aimed at investigating policy components for controlling access and use of data and examining similarities and differences of the policy components across disciplines. For the purpose, the study analyzed policy components for data access and use controls provided by 37 research data repositories overseas. These included twenty repositories in biological and health science, ten in chemistry, earth and environmental science and physics, as well as seven in social science and general science. The analysis showed that common policy components involve copyright/licenses, data citation, disclaimers and embargoes. However, there were differences in diversity of policy components among the disciplines and it indicated that the rationales of access and use controls emphasized would be different in the disciplines.