• Journal of the Korean Operations Research and Management Science Society
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• v.39 no.4
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• pp.153-165
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• 2014

We present a new framework for rental capacity management in which rental capacity is dynamically managed by means of temporary inventory addition/return. While serving customers with its own (native) capacity, the rental firm rents additional rental capacity from an upper echelon rental company so that it can avoid lost sales which may occur when stock is not sufficient, and returns it when stock becomes sufficiently large enough to cope with demands. Formulating the model as a Markov decision process, we investigate a flexible capacity addition/return policy that maximizes the firm's profit with respect to system costs. Numerical study indicates that rental operation with capacity addition/return can be economically favorable over rental operation without capacity expansion/return and can contribute the reduction in the size of native rental capacity.

• East Asian Economic Review
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• v.19 no.3
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• pp.275-322
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• 2015

The key objective of this study is to investigate the return and volatility spillover effects among stock market, credit default swap (CDS) market and foreign exchange market for three countries: Korea, the US and Japan. Using the trivariate VAR BEKK GARCH (1,1) model, the study finds that there are significant return and volatility spillover effects between the Korean CDS market and the Korean stock market. In addition, the return spillover effects from foreign exchange markets and the US stock market to the Korean stock market, and the volatility spillover effect from the Japanese stock market to the Korean stock market are both significant.

• Health Policy and Management
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• v.32 no.3
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• pp.323-329
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• 2022

Background: This study aimed to identify the characteristics of the referral and return of patients to clinics in the endocrinology and cardiology departments at the National Health Insurance Service Ilsan Hospital to evaluate the "referral and return of patients to clinics" program and reduce the rate of returning patients. Methods: From May 2018 to December 2020, we identified the number of visits to referral hospitals and hospital usage status at Ilsan Hospital after returning to clinics. We also identified the patients who returned to Ilsan Hospital within 6 months, defined as "failure to transport," among those recommended to be transported to clinics of the Medical Cooperation Center. Additionally, we evaluated the characteristics of the "failure to transport" patients. Results: Among the returning patients, the rate of visiting Ilsan Hospital within 6 months was higher in cardiology than in endocrinology (25.1% vs. 16.7%). Older age, more severe disease, and more number of visits to the department were associated with a high rate of failure to transport. The rate of failure to return was low in cases diagnosed with hyperlipidemia/lipoprotein metabolism disorder. With respect to diabetes, the rate of failure to transport differed according to each type of diagnosis of diabetes. Conclusion: The success rate of the "referral and return of patient to clinics" program differed based on each patient's characteristics, department of visit, and diagnosis. Individualizing according to the visit department and diagnosis is required to ensure successful transfers, and infrastructure expansion and institutional arrangements must be facilitated.

• Journal of Digital Convergence
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• v.12 no.6
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• pp.115-123
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• 2014

The first, this study analyzed empirically the effects of net profit on sales, total asset turnover and debt ratio on return on equity, the second, verified debt' s mediating effect on return on investment and return on equity and finally, tested the effect of adjusted debt ratio on return on equity in the small medium sized enterprises. Generally speaking, using debt has a positive effect on return on equity. Meanwhile, using debt accelerate return on equity through leverage effect in the quadric function curve model. Eventually, using debt has a positive and negative effects on return on equity. Accordingly, because of the debt' janus-faced reality, using debt is restricted within the level that operating cash flow(or return on asset) excess interest(or rate of interest).

• East Asian Economic Review
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• v.20 no.4
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• pp.469-491
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• 2016

In this paper, we estimate the exchange rate exposure, indicating the effect of exchange rate movements on firm values, for a sample of 1,400 firms in seven East Asian countries. The exposure estimates based on various exchange rate variables, return horizons and a control variable are compared. A key result from our analysis is that the long term effect of exchange rate movements on firm values is greater than the short term effect. And we find very similar results from using other exchange rate variables such as the U.S. dollar exchange rate, etc. Second, we add exchange rate volatility as a control variable and find that the extent of exposure is not much changed. Third, we examine the changes in exposure to exchange rate volatility with an increase in return horizon. Consequently the ratio of firms with significant exposures increases with the return horizons. Interestingly, the increase of exposure with the return horizons is faster for exposure to volatility than for exposure to exchange rate itself. Taken as a whole, our findings suggest that the socalled "exposure puzzle" may be a matter of the methodology used to measure exposure.

• East Asian Economic Review
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• v.25 no.2
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• pp.205-230
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• 2021

This study examines the impact of the number of coronavirus cases on regime-switching in stock return volatility. This study documents the empirical evidence that the COVID-19 cases had an asymmetric effect on the regime of stock return volatility. When the stock return is in the low volatility regime, the probability of switching to the high volatility regime in the next trading day increases as the number of cumulative cases increases. In contrast, in the high volatility regime, the effect of cumulative cases on the transition probability is not statistically significant. This study also documents the evidence that the government measures against the pandemic contribute to promoting the high volatility regime of the KOSPI during the pandemic. Besides, this study projects future stock prices through the Monte Carlo simulation based on the estimated parameters and the predicted number of the COVID-19 new cases. Under a scenario where the number of new cases rapidly increases, stock price indices in Korea are expected to be in a downward trend over the next three months. On the other hand, under the moderate scenario and the best scenario, the stock indices are likely to continue to rise.

• Safety and Health at Work
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• v.13 no.3
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• pp.286-293
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• 2022

Background: The death rate of workers due to industrial accidents in South Korea (3.61 persons in 2017) is higher than the Organization for Economic Cooperation and Development average (2.43) and the fifth highest among Organization for Economic Cooperation and Development member countries. Although the pandemic of novel coronavirus (COVID-19) has changed, the socioeconomic aspects of Korean society, the number of Koreans suffering accidents and the number of deaths in 2020 have increased. It is necessary to take measures to prevent accidents and make comprehensive efforts to return to work. This study proposes research questions about the effect of workers' positive perception on whether to work after accidents and the impact of the experience of rehabilitation services on the return to work. Methods: This research performed a panel logistic regression analysis using data on workers' compensation insurance in Korea for two years (2018-2019). Results: This research finds that workers' positive perceptions of workability and life satisfaction contributed affirmatively to their re-employment. Several factors related to employment (e.g., work period, the number of job qualifications) also positively affect their return to work. However, the experience of rehabilitation services did not have a significant effect on re-employment. The variables of their health conditions (e.g., disability grade, feelings of health problems, age) negatively influenced their return to jobs. Conclusion: These results suggest the importance of workers' mental recovery and the need to innovate rehabilitation services for their employment. Positive thinking and self-rehabilitation could be critical for workers, parallel with social welfare policies.

• Journal of Korean Society of Forest Science
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• v.103 no.2
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• pp.278-286
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• 2014

Forestry management problems in South Korea have been caused by small and scattered forest lands, aging forest owners, and the increase of absentee forest owners. To solve these problems, it is a time to consider the introduction of forest land bank system for the expansion of forestry management scale, the effective management of neglected forest lands, and the stable livelihood support for aged forest owners. Therefore, this research implemented the questionnaire survey of necessity, expectation, willingness to use, and introduction plans for the forest land bank system in order to examine the feasibility and demand of the system focused on forest owners, non-forest owners, and people who return to the farm. The questionnaire survey was conducted for 262 of resident forest owners, 152 of absentee forest owners, 427 of non-forest owners, and 101 of people who return to the farm. 77.5% of forest owners and 63.8% of non-forest owners agreed with the necessity of the introduction for the forest land bank system. Both forest owners and non-forest owners would prefer to use forest land reverse mortgage and leasing among projects of the forest land bank. In addition, 75% of people who return to the farm also expected that forest land bank would be helpful to their rural and mountain life, and they would have higher preference to participate in leasing and buying forest lands than other projects. Based on the outputs of the feasibility and demand survey in this research, this study can play a key role in determining basic direction, major functions, types and range of projects as well as providing information for establishing policies of the forest land bank system.

• Journal of Korean Society of Rural Planning
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• v.9 no.3 s.20
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• pp.17-23
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• 2003

This paper aimed at identifying rural amenities valuable in terms of marketed value and economic analysis of green tourism so as to develop policy instruments for new rural communities. We conducted the case study on Jik-Dong rural community in Taejeon city and estimated income effects of green tourism and internal rate of return of investment for rural amenity facilities. The research results are as followings; (1) green tourism participant will spend the worth of 50,392 won per person, (2) earnings from green tourism amounts to about 2,471 thousand won per household, (3) internal rate of return of green tourism investment is estimated as 7%. The strategies far green tourism is suggested as follows; (1) rural amenities should be well maintained for green tourism infrastructure (2) measures to internalize the value of rural amenities should be developed for market oriented peen tourism (3) effective program for inducing visitors with purchasing power should be designed.

• Atmosphere
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• v.32 no.1
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• pp.1-15
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• 2022

Recently, Japan's Meteorological Research Institute presented the d4PDF database (Database for Policy Decision-Making for Future Climate Change, d4PDF) through large-scale climate ensemble simulations to overcome uncertainty arising from variability when the general circulation model represents extreme-scale precipitation. In this study, the change of precipitation characteristics between the historical and future climate conditions in the Yongdam-dam basin was analyzed using the d4PDF data. The result shows that annual mean precipitation and seasonal mean precipitation increased by more than 10% in future climate conditions. This study also performed an analysis on the change of the return period rainfall. The annual maximum daily rainfall was extracted for each climatic condition, and the rainfall with each return period was estimated. In this process, we represent the extreme-scale rainfall corresponding to a very long return period without any statistical model and method as the d4PDF provides rainfall data during 3,000 years for historical climate conditions and during 5,400 years for future climate conditions. The rainfall with a 50-year return period under future climate conditions exceeded the rainfall with a 100-year return period under historical climate conditions. Consequently, in future climate conditions, the magnitude of rainfall increased at the same return period and, the return period decreased at the same magnitude of rainfall. In this study, by using the d4PDF data, it was possible to analyze the change in extreme magnitude of rainfall.