• The Journal of Asian Finance, Economics and Business
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• v.7 no.11
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• pp.835-842
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• 2020

The study aims to investigate the impact of debt on corporate profitability in the context of Vietnam. The paper investigates the impact of debt on corporate profitability in non-finance listed companies on the Vietnam stock market. The panel data of the research sample includes 118 non-financial listed companies on the Vietnam stock market for a period of nine years, from 2009 to 2017. The Generalized Method of Moments (GMM) is employed to address econometric issues and to improve the accuracy of the regression coefficients. In this research, corporate profitability is measured as the return of EBIT on total assets. The debt ratio is a ratio that indicates the proportion of a company's debt to its total assets. Firm sizes, tangible assets, growth rate, and taxes are control variables in the study. The empirical results show that debt has a statistically significant negative effect on corporate profitability. The result also shows this effect is stronger in a non-linear (concave) way, we show that the debt ratio has nonlinear effects on corporate profitability. From this, experimental evidence shows that the optimal debt ratio is 38.87%. This evidence provides a new insight to managers of the non-finance companies on how to improve the firm's profitability with debt.

• Journal of Korean Foot and Ankle Society
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• v.23 no.3
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• pp.83-90
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• 2019

Achilles tendon rupture is a common sports injury encountered in younger populations. Various treatment methods are used for acute and chronic rupture. Several treatments for each condition are available, each having their advantages and disadvantages. In an acute rupture, surgical treatment may be a priority for younger patients or those wishing a quick return to play, but the long-term functional outcome is similar to non-surgical treatment. In addition, the re-rupture rate shows a slight difference between the two treatments. The clinical outcomes are similar regardless of the surgical treatment, but an accelerated rehabilitation program should be accompanied by good results. In chronic and neglected rupture, surgical treatment is preferred over non-surgical treatment. Treatments are chosen based on the size of the tendon defect. This article reviews the current updates in the treatment of Achilles tendon rupture that will help clinicians choose the appropriate treatment.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.771-776
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• 2000

Fine grid calculations are reported for the developing turbulent flow in a straight duct and a curved duct of square cross-section with a radius of curvature to hydraulic diameter ratio ${\delta}=R_c/H_H=3.357$ and a bend angle of 180 deg. A sequence of modeling refinements is introduced; the replacement of wall function by a fine mesh across the sublayer and a low Reynolds number second moment closure up to the near wall sublayer in which the non-linear return to isotropy model and the cubic-quasi-isotropy model for the pressure strain are adopted; and the introduction of a multiple source model for the exact dissipation rate equation. Each refinement is shown to lead to an appreciable improvement in the agreement between measurement and computation.

• The Journal of the Korea Contents Association
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• v.13 no.3
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• pp.352-361
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• 2013

The purpose of this study is to analyse the impact of macroeconomic and non-macroeconomic forces on the management performance of the air transport firms and offer the useful information to the managers. To conduct the regression analysis, eight macroeconomic and non-macroeconomic variables were selected individually as an independent variable. Macroeconomic variables were the return of corporate bond, West Texas Intermediate, the unemployment rate, the money supply, the trade balance, the won to USD exchange rate, the consumer price index and the index of industrial production. And non-macroeconomic variables were Taiwan earthquake, the Asian economic crisis, the 911 terrorist attacks in the US, the Iraq war, Beijing Olympic, the outbreak of a swine flu epidemic, the 1st presidential election and the 2nd presidential election. And ROA was selected as a dependent variable. As the result of analysis, it was found that the changing rates of won to USD exchange rate and consumer price index affected the changing rate of ROA significantly. And also as the result of analysing the impact of two significant macroeconomic variables and eight non-macroeconomic variables on the changing rate of ROA, it was found that the Asian economic crisis and the outbreak of a swine flu epidemic had a negative impact on it. Therefore managers should take note of a change in macroeconomic and non-macroeconomic variables carefully to improve the management performance.

• Korean Journal of Agricultural Science
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• v.27 no.2
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• pp.158-175
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• 2000

Up to date, the economic feasibility analysis on land consolidation and on-farm development projects were mainly depended upon the direct benefits from market value of project outputs. Therefore the projects were neglected in allocation of the government's financial funds and loans on account of undervaluation of the project benefits including socio-economic and environmental values of the projects. Accordingly the Extended Benefit Cost Analysis Method should be adapted to cover not only the benefits such as non-market values of environmental functions of the projects and but also the economic market values of the project outputs. The main objectives of this study is (1) to provision of the guideline for economic feasibility analysis based on the IBRD and ADB guidelines, (2) to estimate the benefits such as Productivity increase effect, labor saving effect, off-farm income increase effect during off-farm season, saving of O&M cost of farm mechanization, enhance of farmer's public health, increase of environmental public function of paddy fields, effect of food security and establishment of peaceful and uncontroversial rural society by implementing the land consolidation and on-farm development, (3) to introduce the newly adapted analytical method as the extended benefit cost analysis which could make possible the analysis of non-market goods such as the food security value and the environmental public value of paddy fields. To carry out the study, the publication on the guideline for economic analysis of agricultural projects were reviewed and consulted and for the post evaluation of the land consolidation and on-farm development project, field survey in Jeongja area were made for the feasibility study of the project by new method. According to the initial project plan, Jeongja land consolidation and on-farm development project has 96ha of benefit area and the project was started in 1989 and completed in the spring, 1990. The total project costs were amounted to 1,052 million won and the annual project benefits were estimated at 135.4 million in 1989 constant market prices. On the other hand, the newly estimated project benefits as a part of post evaluation of the project were amounted to 602.1 million won including all the benefits from the market and non-market commodities of the project as mentioned above column. The original IRP(Internal rate of return) of the project was estimated at 15.81%. On the other hand, the IRR of the post evaluation of the project was amounted to 16.83%. In case of including the benefit from the environment public function of paddy field, the SRR(Social Rate of Return) was reached to 38.81% and when we added the benefit from food security of the project, the SRR showed very high rate as 46.41%. In conclusion, the project were verified socio-economically feasible and environmentally sustainable considering the above decision making criteria.

• Management Science and Financial Engineering
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• v.21 no.2
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• pp.13-23
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• 2015

This study addresses the question as to whether the option prices have useful predictive information on the direction of stock markets by investigating a forecasting power of volatility curvatures and skewness premiums implicit in S&P 500 index option prices traded in Chicago Board Options Exchange. We begin by estimating implied volatility functions and risk neutral price densities every minute based on non-parametric method and then calculate volatility curvature and skewness premium using them. The rationale is that high volatility curvature or high skewness premium often leads to strong bullish sentiment among market participants. We found that the rate of return on the signal following trading strategy was significantly higher than that on the intraday buy-and-hold strategy, which indicates that the S&P500 index option prices have a strong forecasting power on the direction of stock index market. Another major finding is that the information contents of S&P 500 index option prices disappear within one minute, and so one minute-delayed signal following trading strategy would not lead to any excess return compared to a simple buy-and-hold strategy.

• Journal of ILASS-Korea
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• v.11 no.4
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• pp.228-233
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• 2006

There are two types of electric controlled fuel injection system in the gasoline engines of common vehicles. One is fuel return system and the other is fuel returnless system according to the methods of controlling injection pressures. It is important to understand the characteristics of these system in loaming and studying of engine, but it is very difficult without a special equipment in reality. The purpose of this paper is to develop the emulation system that can be compensated with the amount of injection fuel according to various driving conditions, battery voltage, cooling water temperature, and engine speed, may be appeared in real driving, and especially can analyze the difference between the electric signal controlling the amount of injection fuel and its result, and nullity injection duration. With the developed system, we can conveniently set various and completed driving condition and so can acquire the useful information such as non-uniformity rate and mass of injection fuel using waveform analysis and measurement modules. It must be a very useful and sophisticated system to instruct and learn the features and operating states of injection system, and to study f3r improving the performance of it.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.2
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• pp.81-92
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• 2022

The necessity for a theoretical explanation of the negative association between capital structure and company performance is identified in this study. By focusing on accounting metrics of business performance, this study is the first to investigate the moderating effects of firm size between these variables using logical reasoning. Due to the possibility of endogeneity, this study applies a two-step system GMM approach with data from 285 non-financial enterprises from PSX over a 21-year period. For robustness, we employed pooled OLS, fixed effect, and two-step difference GMM. Our data show that leverage has a detrimental impact on business performance, with size acting as a moderator in the same direction. Our analysis empirically supports some studies while refuting others due to inconsistent results in the literature, but no study has theoretically justified their negative link. We believe that because larger companies have more and easier access to capital markets, they focus primarily on the amount of return, even if the investment is inefficient in terms of the rate of return, but small businesses do not. As a result of this thinking, firm managers' performance suffers as a result of leverage.

• The Korean Journal of Applied Statistics
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• v.31 no.6
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• pp.677-692
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• 2018

The total fertility rate of Korea was 1.05 in 2017, showing a return to the 1.08 level in the year 2005. 1.05 is a very low fertility level that is far from replacement level fertility or safety zone 1.5. The number may indicate a low fertility trap. It is therefore important to predict fertility than at any other time. In the meantime, we have predicted the age-specific fertility rate and total fertility rate by various statistical methods. When the data trend is disconnected or fluctuating, it applied a nonparametric method applying the smoothness and weight. In addition, the Bayesian method of using the pre-distribution of fertility rates in advanced countries with reference to the three-stage transition phenomenon have been applied. This paper examines which method is reasonable in terms of precision and feasibility by applying estimation, forecasting, and comparing the results of the recent variability of the Korean fertility rate with parametric, non-parametric and Bayesian methods. The results of the analysis showed that the total fertility rate was in the order of KOSTAT's total fertility rate, Bayesian, parametric and non-parametric method outcomes. Given the level of TFR 1.05 in 2017, the predicted total fertility rate derived from the parametric and nonparametric models is most reasonable. In addition, if a fertility rate data is highly complete and a quality is good, the parametric model approach is superior to other methods in terms of parameter estimation, calculation efficiency and goodness-of-fit.

• Journal of The Korean Digital Architecture Interior Association
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• v.12 no.1
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• pp.89-98
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• 2012

While the housing transaction price of Seoul tends to be stagnant or declining in line with the housing market recession since 2007, the jeonse price keeps continual increase. Such flow of jeonse price change has a serious influence on ordinary person's housing stability seriously. Therefore, it is very meaningful in terms of social policy to analyze the trend of recent jeonse price change. This study aims to have an empirical analysis of structural characteristics of the trend of recent jeonse price change. After the review of various previous studies, this study selected housing jeonse price index, non-sold house quantity, jeonse vs. transaction price rate, and housing construction performance as analytical variables, and employed monthly time series resources from January 2007 to April 2011. As a result, when the housing supply reduced, the potential quantity for jeonse market reduced that occurred unbalance of supply and demand in jeonse market. In turn, it caused the increase of jeonse price. And, in case of jeonse vs. transaction price rate change, the rate increased which means the increase of required rate of return of invested demand. As such, the increase of market risk degenerates the investment sentiment which caused the reduction of quantity for jeonse market as a submarket.