• Journal of the Korean Society of Industry Convergence
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• v.25 no.3
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• pp.467-476
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• 2022

The Bank of Korea raised the benchmark interest rate by a quarter percentage point to 1.75 percent per year, and analysts predict that South Korea's policy rate will reach 2.00 percent by the end of calendar year 2022. Furthermore, because market volatility has been significantly increased by a variety of factors, including rising rates, inflation, and market volatility, many investors have struggled to meet their financial objectives or deliver returns. Banks and financial institutions are attempting to provide Robo-Advisors to manage client portfolios without human intervention in this situation. In this regard, determining the best hyper-parameter combination is becoming increasingly important. This study compares some activation functions of the Deep Deterministic Policy Gradient(DDPG) and Twin-delayed Deep Deterministic Policy Gradient (TD3) Algorithms to choose a sequence of actions that maximizes long-term reward. The DDPG and TD3 outperformed its benchmark index, according to the results. One reason for this is that we need to understand the action probabilities in order to choose an action and receive a reward, which we then compare to the state value to determine an advantage. As interest in machine learning has grown and research into deep reinforcement learning has become more active, finding an optimal hyper-parameter combination for DDPG and TD3 has become increasingly important.

• Journal of Navigation and Port Research
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• v.46 no.5
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• pp.441-448
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• 2022

The aim of this study was to examine determinants of secondhand Bulk carrier and Oil tanker prices. This study compiled S& P transaction data taken from the Clarksons Research during J anuary 2018 to April 2022 to see how independent variables influenced secondhand ship prices. In the secondhand ship pricing model of entire segments, size, age, and LIBOR showed significant effects on prices. A vessel built in J apan and Korea was traded at a higher price than a vessel built in other countries. In the bulk segment, size, age, Clarksea index, LIBOR, and inflation were meaningful variables. In the Tanker segment, unlike Bulk carrier, only size and age were useful variables. This study performed regression analyses for various sizes of Bulk carriers and Oil tankers. It verified that impacts of variables other than ship size and age were significantly associated with ship type and size while macroeconomic variables had no influence except for bulk carriers. By applying diverse variables affecting secondhand ship price estimation according to various sizes of Bulk carriers and Oil tankers, this study will expand the scope of practical application for investors. It also reaffirms prior research findings that the secondhand ship market is primarily market-driven.

• Health Policy and Management
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• v.32 no.3
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• pp.247-257
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• 2022

The presidential election and the inauguration of the new government are a period of the policy window opening. The newly launched government is expected to improve the quality of life of the people. The Yoon Suk-yeol Government is also launched with new expectations with a transitional period in health care. The sustainability of health care in Korea is threatened. The environment of health care and the main policy issues of health care are difficult to secure the necessary finance for health care in spite of the increasing health care burden. Accordingly, the Yoon Suk-yeol Government's health care policy aims to provide intensive support to those in need of health and welfare and to improve the health of the people through investment in health. And for integrating fragmented health care and welfare services and creating people-centered community-based health care, a health care innovation center will be established for the evaluation platform of new delivery and payment systems, a health care development plan will be established for the blueprint of health care, and reorganizing the central & local government should be reviewed. Although we are facing unfavorable situations such as the distribution of the National Assembly, inflation, and the possibility of economic recession, we expect that announced health care policies will be implemented, recognizing that health care innovation is the only way to improve health care sustainability.

• Journal of radiological science and technology
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• v.45 no.4
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• pp.355-363
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• 2022

This study was to investigate the prevalence rate of musculoskeletal disorders in relation to general characteristic factors, living environment factors, and work environment factors for sonographer's. For the response questions, the guidelines for musculoskeletal burden work were used. For statistical analysis, SPSS 26.0 version was used. For the common body parts of the sonographer's who responded, the prevalence was investigated by dividing the group into a group with high pain or discomfort and a group with low pain or discomfort according to the degree to which they experienced symptoms during the past 12 months. Multiple logistic regression analysis was used to determine the variance inflation factor(VIF), odds ratio (OR) and corresponding 95% confidence interval (CI). A p-value of <0.05 was considered statistically significant. As a result, housework hours, examination history, regular physical activity, number of patient examinations per day, and sitting posture were investigated as variables for rate musculoskeletal disorders. The sonographer's occupational group was found to have a high prevalence rate of musculoskeletal disorders like various other occupational groups. Based on the results of this study, it is judged that musculoskeletal disorders can be reduced by recognizing musculoskeletal disorders and improving work environment factors.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.5
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• pp.853-859
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• 2022

In this study, we analyzed the instantaneous trajectory generation capability and target arrival rate of a mobile robot by changing the parameter of the TEB (Timed Elastic Band) Local Planner among local planners that affect the instantaneous obstacle avoidance ability of the mobile robot using ROS (Robot Operating System) simulation and real experience. As a result, we can expect a decrease in the target arrival time of the mobile robot through a decrease in the parameter values of the TEB Local Planner's min_obstacle_dist, inflation_dist, and penalty_epsilon. However, if this parameter is reduced too much, the risk of obstacle collision of the moving robot is increases, so it is important to combine the appropriate values to construct the parameter.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.171-176
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• 2023

What we have in common worldwide today is economic difficulties due to high inflation and uncertainty in the financial industry. The root cause of this is the war between Russia and Ukraine. The war between Russia and Ukraine is not simply a war between two countries. The United States and the European Union are providing military aid such as missiles to Ukraine, and Russia is attacking Ukraine by introducing UAVs (unmanned aerial vehicles) from Iran. A prominent weapon in this Russia-Ukraine war is the UAVs used in Russia. It is predicted that the form of war using UAVs will gradually expand in the future based on stealth. In addition, UAVs will continue to be used due to the fact that they can cause serious damage to the other country without harming their own lives, and because they have good cost-effectiveness. In this study, UAVs based on autonomous driving were studied. The target countries of the study include the United States, the European Union, China, and Iran, and the UAVs used in these countries have characteristics that can represent the world. In this study, the main specifications of major UAVs in use in major countries were investigated. In addition, the future technology and development direction were described through specifications and characteristics of UAVs currently in operation in major countries.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.5
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• pp.355-363
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• 2022

The debt maturity structure has a significant impact on a company's financial situation. Any debt maturity structure decisions substantially impact investment decisions due to changes in capital cost and dividend decisions due to cash flow consequences. This study used the system generalized method of moment (Sys-GMM) to investigate the debt maturity structure of real estate companies listed on the Ho Chi Minh Stock Exchange (HOSE) in the duration from 2008 to 20019. It found that the firm size, liquidity, and tangible assets affected the decision on debt maturity structure. The tangible asset had the most significant impact on the possibility for companies to access long-term loans. This finding revealed that the majority of the real estate companies listed on HOSE borrowed money from banks. Such decisions are most likely affected by the collateral. Another finding of the study is that financial institutions had a major impact on loan maturity structure, whereas the effects of the financial market were negligible. Besides, the real estate companies listed on HOSE seemed not to pay attention to changes in inflation, economic growth, and institutional qualities when deciding on the debt maturity structure.

• Archives of Plastic Surgery
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• v.49 no.3
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• pp.373-377
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• 2022

Currently, robot-assisted latissimus dorsi muscle flap (RLDF) surgery is used in treating patients with Poland syndrome and for breast reconstruction. However, conventional RLDF surgery has several inherent issues. We resolved the existing problems of the conventional system by introducing the da Vinci single-port system in patients with Poland syndrome. Overall, three patients underwent RLDF surgery using the da Vinci single-port system with gas insufflation. In the female patient, after performing RLDF with silicone implant, augmentation mammoplasty was also performed on the contralateral side. Both surgeries were performed as single-port robotic-assisted surgery through the transaxillary approach. The mean operating time was 449 (335-480) minutes; 8.67 (4-14) minutes were required for docking and 59 (52-67) minutes for robotic dissection and LD harvesting. No patients had perioperative complication and postoperative problems related to gas inflation. The single-port robot-assisted surgical system overcomes the drawbacks of previous robotic surgery in patients with Poland syndrome, significantly shortens the procedure time of robotic surgery, has superior cosmetic outcomes in a surgical scar, and improves the operator's convenience. Furthermore, concurrent application to another surgery demonstrates the possibility in the broad application of the robotic single-port surgical system.

• Health Policy and Management
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• v.3 no.1
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• pp.84-101
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• 1993

The current method of rate adjustment is based on the evaluation of the financial performance of hospitals. The method has the disadvantages such as too complicated, expensive process as well as low reliability due to small sample size. This study, therefore, develops a new model for the rate adjustment with the use of the composite index. In addition to that, it examines the validity of the model by comparing the result of the new method with that of the conventional method. The idea of the new model comes from the Medicare Economic Index(MEI) on which physician fees for the Medicare patients are adjusted periodically in the United States. Medical costs are classified into three groups : labor costs, materials and other expenses. Labor costs are subdivided into physicians and other personnels. Materials are subdivided into drugs and others. Other expenses are subdivided into 5 items. Macro economic indices are selected for each cost item in order to reflect the cost inflation during the specific period. Then the composite index which integrate all items according to the ration of each item in the total costs is calculated. The result from the application of empirical data to the new model is very similar to that of the current method. Furthermore, this method is very simple and also to easy to get social concensus. This model can be replaced the current method based on the analysis of the financial performance for the adjustment of medical fees.

• The Korean Journal of Franchise Management
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• v.14 no.2
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• pp.1-17
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• 2023

Purpose: Due to the COVID-19 and inflation, participation sports companies, including fitness centers, are facing challenges. Since a fitness center must simultaneously manage facilities and operate services, both factors must be considered when developing a marketing strategy. Therefore, this study examines the effects of expanded marketing mix factors (price, physical evidence, place, people, product, and promotion) including facilities and services on the consumption behavior (satisfaction, recommendation intention, repurchase intention) of fitness center customers. Research design, data, and methodology: The data were collected from sample of 323 fitness club members in Seoul and analyzed with SPSS Win Ver.28.0 program. Result: The specific results of the study were as follows; First, extended marketing mix factors had significant positive (+) effect on satisfaction. Second, extended marketing mix factors had significant positive (+) effect on recommendation intention. Third, extended marketing mix factors had significant positive (+) effect on repurchase intention. Fourth, satisfaction had significant positive (+) effect on recommendation intention and repurchase intention. Conclusions: To encourage consumption behavior, it is necessary to convert existing customers into loyal ones by increasing satisfaction and establishing a virtuous cycle structure that recommends them to others while also improving repurchase intention.