• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.10 no.2
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• pp.45-56
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• 2004

OBJECTIVE: The objective of this study was to know the effects of the postoperative lumbar extensor strengthening exercise program on back muscles strength and volume, pain, and the time of return to work. METHODS: A prospective controlled trial of lumbar extensor exercise program in patients who underwent microdiscectomy or percutaneous endoscopic discectomy for prolapsed lumbar intervertebral disc. Seventy-five patients were randomized into exercise group (20 male, 15 female) and non-exercise group (18 male, 22 female). Six weeks after surgery, patients in exercise group undertook a 12-week lumbar extension exercise (MedX) program. Assessment of spinal function was performed in all patients on postoperative 6 weeks, 18 weeks. The assessment included measures of lumbar extensor power, muscle mass of erector spinalis. All patients completed the visual analog scale (VAS) for evaluation of pain, and return to work. RESULTS: In muscle power, there were statistically significant improvements between pre and post test on muscle power in exercise group. But there were not statistically significant difference on muscle power in non-exercise group. In muscle mass, there were statistically significant difference between pre and post test on muscle mass in exercise group. But there were not statistically significant difference on muscle mass in non-exercise group. In the pain, there were statistically significant decrease between pre and post test on both group. But there were not statistically significant difference on fatty tissue and obesity in non-exercise group. The percentages of return to work in postoperative 4 months were significantly greater in the exercise group than in the non -exercise group. CONCLUSIONS: Postoperative lumbar extensor strengthening exercise program appears to be more beneficial to the patients who underwent operation for prolapsed lumbar intervertbral disc.

• Journal of Biosystems Engineering
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• v.39 no.4
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• pp.267-273
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• 2014

Purpose: This study was conducted to develop a web-based business management system to ensure the efficient operation and transparent management of government-subsidized agricultural machinery rental businesses. Methods: An MS_SQL2000 database management system (DBMS) solution was utilized in the system for high system compatibility and integrated management. This system was targeted to be compatible with Internet Explorer 6.0 or later and to ensure security and seamless web operations. The system administrator is able to manage a fleet of agricultural machinery, including various inventory codes, release and return, fleet registry, and business performance. Users (farmers) may search the database of rental machinery and reserve them. Results: With respect to rental reservations, the system administrator can manage the fleet by setting the rental status to Approved, Released, or Returned. Through the web, the administrator can also create a database that includes machinery specifications, features, and rental rates. In addition, business performance data can be analyzed using a diverse array of tools to streamline the rental business. Without having to go to the rental office, users can save time and money by searching for and renting agricultural machinery through the information available on the website, including availability, specifications, and rental fees. After deploying the system, the time required to analyze monthly performance and create reports was dramatically reduced from 20 days per person to one day per person. Conclusions: Since 2014, AMRB has been installed and is operating in agricultural machinery rental businesses in 31 cities and counties in South Korea. This study recommends continued expansion and dissemination of AMRB for the systematic and efficient management of agricultural machinery rental businesses.

• Management & Information Systems Review
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• v.27
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• pp.131-147
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• 2008

The study examines common component existing in five Asian countries from 1991 to 2007. To do this, the daily stock market indices of Korea, Malaysia, Thailand, Indonesia, and the Philippines were used. Using a Vector Autoregressive Model this paper analyzes causal relations and dynamic interactions between five Asian stock markets. The findings in this study indicate that level of five Asian stock markets' stock return linkages are low. First, from the statistics for pair-wise Granger causality tests, I find Granger-causal relationship between Korea and Indonesia and between Malaysia and and Indonesia. Second, from the results of response function and the statistics of variance decomposition, I find that week shocks to Korean stock market return on Malaysia, Indonesia, Thailand, and the Philippines stock market returns. The results indicate increased Asian stock market linkages but the level is very low. This implies that the benefits of diversification within the five Asian stock markets are still existed.

• The Korean Journal of Financial Studies
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• v.3 no.2
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• pp.329-364
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• 1996

Writing naked put options is a strategy employed either as a speculation to capture premium income, or as a method of placing a limit order to buy the underlying at the strike price in return for premium received. Using a Monte Carlo simulation, twenty thousand equity prices are generated under known volatility and return parameters. A binomial tree is constructed using the same volatility and return parameters. Put options on these 'equities' are valued with the binomial methodology. The performance of various put writing strategies is evaluated on a risk-adjusted basis. Evidence presented suggests that the judicious use of put options may enhance returns during portfolio construction.

• Management & Information Systems Review
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• v.27
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• pp.31-52
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• 2008

Intangible Assets are more important determinants of firm value than others in a digital information-based economy(Lev, 2001). Prior research reveals that investments in intangible assets such as R&D and advertising expenditures are associated with firm value. This paper examines the effects of the corporate investments in the information technologies(IT) on stock return and economic goodwill. The sample consists of 152 firms listed on the Korean stock market in 2002. To test hypothesis We employed multiple regression models. Results are as follows; First, IT environment, IT process, and IT human resource are positively associated with firm's IT value. Second, firm's IT value is positively correlated with firm's economic goodwill. Third, firm's IT value is positively correlated with firm's stock return. These results suggest that the investments related with IT are effective in cultivating firm's value and Stock investors can make the best use of firm's announcements related with IT value. Thus the authorities concerned need to expand the public announcements related IT value.

• 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 the Korea Safety Management & Science
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• v.11 no.3
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• pp.181-188
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• 2009

This paper presents the economic validity with the cost/benefit analysis on establishing R&D Supreme Academy. To evaluate the profitability of R&D Supreme Academy, willingness to pay (WTP) is measured by contingent valuation method (CVM) and then the net present value (NPV), internal rate of return (IRR) and benefit/cost ratio(BCR) are calculated. The results of economic evaluation verified that the establishment of R&D Supreme Academy is timely and effective in an economic perspective.

• Culinary science and hospitality research
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• v.24 no.1
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• pp.130-139
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• 2018

The purpose of this study was to grasp the profitability of coffee franchise companies using ROIC tree, ROA and ROE. As a result, ROA was using assets efficiently, and some companies are in desperate need to improve their management based on past brand recognition, and a new paradigm management strategy is urgently required. In particular, the franchise company's current cost burden is greater than comparable firms. In ROE, the capital was operating efficiently. Since ROIC is very difficult to classify business related and operating related amounts accurately based on financial statement information, there is a limit to accurate ROIC calculation. Therefore, ROIC is estimated to be 7.6~38.29% as of 2016 based on ROIC calculation. In the case of continuous growth companies, investments are made to improve steady sales, but some companies seem to be unable to escape from past paradigm. In order to continue the growth of the company beyond the accounting profit in the future, the ROIC Tree can be used to measure the subdivided management performance and propose efficiency plan.

• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3126-3132
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• 2023

To meet the increasing heating needs of the China Fusion Experimental Tokamak Reactor (CFETR), the output power in each Lower Hybrid Current Drive (LHCD) transmission line should be increased from 250 kW to 500 kW. Therefore, a new high-power water load must be developed for the 4.6 GHz 500 kW LHCD system. This paper aims to report the most recent research progress of the water load: aluminum nitride (AlN) ceramic is used as the media material to isolate the water and vacuum, and the radio frequency (RF) simulation results show that the return loss of the water load is less than -25dB at 4.6 GHz over a wide temperature range. Under 500 kW continuous wave (CW) operation, the maximum temperatures of the ceramic and water are separately 67 ℃ and 62 ℃, resulting in thermal deformation of the ceramic of approximately 0.003 mm. Moreover, the AlN water load was tested on the 4.6 GHz 250 kW high-power test bench and found to work well with low reflected power.

• Management & Information Systems Review
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• v.26
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• pp.1-26
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• 2008

Since Capital Asset Pricing Model(CAPM) was proposed in the early 1960s by William Sharpe(1964) and John Lintner(1965) researchers have investigated the validity of the model. The results of empirical researches do not show that expected returns of stocks seem to be determined solely by systematic risk of the stocks as precicted by CAPM. In this paper the relationship between transaction volume and expected returns of stocks was investigated. Empirical cross-sectional analysis about the data collected from Stock Market of Korea Exchange shows transaction volume and variability of stock returns play an important role in pricing assets. The well-known variables which were used traditionally to explain the differences of expected returns among stocks such as the size and beta of a stock seems to be unimportant in pricing assets.