• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.11
• /
• pp.1511-1517
• /
• 2013

This study was performed to estimate the effect of age at first calving and first two calving intervals on productive life and life time profit in Korean Holsteins. Reproduction data of Korean Holsteins born from 1998 to 2004 and lactation data from 276,573 cows with birth and last dry date that calved between 2000 and 2010 were used for the analysis. Lifetime profit increased with the days of life span. Regression of Life Span on Lifetime profit indicated that there was an increase of 3,800 Won (approximately $3.45) of lifetime profit per day increase in life span. This is evidence that care of each cow is necessary to improve net return and important for farms maintaining profitable cows. The estimates of heritability of age at first calving, first two calving intervals, days in milk for lifetime, lifespan, milk income and lifetime profit were 0.111, 0.088, 0.142, 0.140, 0.143, 0.123, and 0.102, respectively. The low heritabilities indicated that the productive life and economical traits include reproductive and productive characteristics. Age at first calving and interval between first and second calving had negative genetic correlation with lifetime profit (-0.080 and -0.265, respectively). Reducing age at first calving and first calving interval had a positive effect on lifetime profit. Lifetime profit increased to approximately 2,600,000 (2,363.6) from 800,000 Won ($727.3) when age at first calving decreased to (22.3 month) from (32.8 month). Results suggested that reproductive traits such as age at first calving and calving interval might affect various economical traits and consequently influenced productive life and profitability of cows. In conclusion, regard of the age at first calving must be taken with the optimum age at first calving for maximum lifetime profit being 22.5 to 23.5 months. Moreover, considering the negative genetic correlation of first calving interval with lifetime profit, it should be reduced against the present trend of increase.

• Management & Information Systems Review
• /
• v.35 no.3
• /
• pp.195-212
• /
• 2016

Utilizing intra-day volume weighted average price (VWAP) based on 1 minute return data of stocks traded on the Korean Stock Exchange, this paper examines and analyzes abnormal returns in reaction to patent listing disclosures as well as the cumulative abnormal returns, traded volumes, the interaction of VWAP spreads, the reaction of volumes, the reaction of VWAP spreads and the realized returns obtained from trading using an event driven arbitrage strategy. The results of the aforementioned research topics are follows. First, our analysis suggests that on average, 0.92% positive cumulative returns arise 1 minute after the patent listing disclosure announcement with high statistical significance, thereby reconfirming that the Korean stock market is a semi-strong form of the efficient market. Employing 3 separate panel tests differentiated by the size factor, we find that the abnormal returns of small sized stocks were less than the returns of medium sized stocks, which goes to support recent research findings suggesting that the size premium is no longer existent in the Korean stock market. Secondly, we show that among the event driven type strategies, the most outstanding realized returns are from the market making strategies. Furthermore, placing market order trades only at the bid or ask price resulted in negative returns. This implies that strategies utilizing a combination of market orders and limit orders, order cancelations ratios and order flows can enhance realized returns.

• The Korean Journal of Financial Management
• /
• v.26 no.3
• /
• pp.199-226
• /
• 2009

We examine the intertemporal relation between risk and return in the Korean stock market and foreign exchange market based on the two factor ICAPM framework. The standard GARCH model and the GJR(1993) model are employed to estimate conditional variances of the stock returns and foreign exchange rates. The covariance between the rates of stock returns and changes in the exchange rates are estimated by the constant conditional correlation model of Bollerslev(1990) and the dynamic conditional correlation model of Engle(2002). The multivariate GARCH in mean model and quasi-maximum likelihood estimation method, consequently, are applied to investigate riskreturn relation jointly. We find that the estimated coefficient of relative risk aversion is negative and statistically significant in the post-financial crisis sample period in the Korean stock market. We also show that the expected stock returns are negatively related to the dynamic covariance with foreign exchange rates. Both estimated parameters of conditional variance and covariance in the foreign exchange market, however, are not statistically significant. The GJR model is better than the standard GARCH model to estimate the conditional variances. In addition, the dynamic conditional correlation model has higher explanatory power than the constant correlation model. The empirical results of this study suggest following two points to investors and risk managers in hedging and diversifying strategies for their portfolios in the Korean stock market: first, the variability of foreign exchange rates should be considered, and second, time-varying correlation between stock returns and changes in foreign exchange rates supposed to be considered.

• Journal of Preventive Medicine and Public Health
• /
• v.19 no.2 s.20
• /
• pp.213-223
• /
• 1986

Ratio analysis allows a hospital to evaluate its own performance over time and to compare its performance with that of other hospitals. For this study, three types of ratio analysis were conducted based on some data on hospitals in Massachusetts. First, Key ratios influencing financial performance were identified using discriminant analysis. Second, the financial structures of the teaching and the non-teaching hospitals were compared using ratios and multiple comparison method. Third, the effects of the prospective reimbursement law of the state on financial performance were examined using ratios and paired t-test. The purpose of the law is to reduce hospital costs by setting the revenue ceiling prior to the effective budget year. The findings of this study were as follows: 1) When hospitals were divided into three groups, according to their operating income, only profitability ratios showed a consistent difference among the groups. 2) In the discriminant analysis, five ratios were selected: current ratio, operating margin, return on assets, fixed assets turnover, and inventory turnover. They are the key ratios to be monitored periodically for the purpose of evaluating the financial performance of hospitals. 3) When teaching hospitals were compared with non-teaching hospitals, acid ratio, days of cash on hand, and inventory turnover were statistically significant before the law went into effect, whereas only fixed assets turnover and inventory turnover were significant afterward. Contrary to previous studies, profitability ratios of teaching hospitals were higher than those of non-teaching hospitals, although the differences were not statistically significant. 4) When the ratios between the two periods (before and after the law) were compared, three profitability ratios (operating margin, return on assets, and return on equity) were significant for teaching hospitals, whereas three activity ratios (total assets turnover, fixed assets turnover, current assets turnover) were significant for non-teaching hospitals. Furthermore, while both total operating revenue and expenses were decreased, net operating income was increased, due to a greater decrease in total operating expenses. This shows that the law can indeed, simultaneously, achieve both a reduction in costs as well as an improvement in the financial situation of hospitals.

• Management & Information Systems Review
• /
• v.31 no.4
• /
• pp.287-307
• /
• 2012

We empirically examine the price discovery dynamics among the VKOSPI, the KOSPI200 spot, and the KOSPI200 futures markets. The analysis employs the vector-autoregression, Granger causality, impulse response function, and variance decomposition using both daily data from 2009. 04. 13 to 2011. 12. 30 and 1 minute data from the bull market, bear market, and the flat period. The main results are as follows; First, the lead lag relationships between KOSPI200 spot(futures) yield VKOSPI returns could not be found from the daily data analysis. But KOSPI200 spot(futures) have a predictive power for VKOSPI from 1 minute data. Especially KOSPI200 spot(futures) and VKOSPI show the bi-directional effects to each other during the return rising period Second, We chose the VAR(1) the model in daily data but adopt the VAR(3) model in the one minute data to determine the lead lag time. We know that there is predictability during the very short period Third, Spot returns and futures returns makes no difference in daily data results. According to the one minite data results, VKOSPI returns have a predictive power for KOSPI200 spot return, but have no predictive power for KOSPI200 futures return.

• KEPCO Journal on Electric Power and Energy
• /
• v.5 no.3
• /
• pp.141-147
• /
• 2019

Recently, the biggest issue in the electricity industry is the increase in renewable energy, and various technologies are being developed to ensure the capacity of the power system. In addition, super-grids linking power systems are being pushed to utilize eco-friendly energy between countries and regions worldwide. The HVDC transmission technology is required to link the power network between regions with different characteristics of the power system such as frequency and voltage. Until now, Korea has applied HVDC transmission technology that connects mainland and Jeju Island with submarine cables. But, the HVDC transmission technology is still developing for long-distance high-capacity power transmission from power parks on the east coast to load-tight areas near the metropolitan area. Considering the high population density and mountainous domestic environment, it is pushing for commercialization of the design technology of the ${\pm}500kV$ Double Bipole with metallic return wire transmission line to transmit large-scale power of 8 GW using minimal right of ways. In this paper, the insulation characteristics were studied for the design of double-bipole transmission tower with metallic return wire, which is the first time in the world. And the air insulation characteristics resistant to the various overvoltage phenomena occurring on transmission lines were verified through a full-scale impulse voltage test.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.9 no.5
• /
• pp.129-139
• /
• 2014

This study supplements the limitation as much as possible that existing literatures have, and, on the target of new registered businesses to KOSDAQ, this study presents answers to the worries raised earlier by recovering problems on causal relationship direction between foreigner investment and dividend level and by analyzing them with dividend level as an independent variable. First, with the whole samples used, dividend income rate didn't show significant relationship with foreigners' investments. It is similar to study result of the existing literature. A panel analysis, on the target of sample businesses that paid dividends before foreigners' investments originated, showed that foreigners' investments didn't have a significant effect on dividend rate. It means that foreigner investors don't have an effect on dividend level. But, a panel analysis of samples shows that foreigner investments have a significant thesis relationship with dividend level variable, that is dividend return rate, except the businesses which paid dividend before foreigners' investments originated. It means that in case foreign investors' preference is controlled, in the businesses which pay dividends, foreign investors have a significant effect on dividend level to native KOSDAQ. Especially, this study result is very significant, for it shows that dividend return rate, insignificant in existing studies, was significant when foreigners' preferences to the businesses which pay dividends was controlled. It means that the more foreigners' shares increase, the more relative importance of dividend out of all profits increases, compared with all of the amounts at the time, and that foreign investors stick to short-term profit and induce big dividend.

• Journal of Navigation and Port Research
• /
• v.39 no.1
• /
• pp.69-75
• /
• 2015

The concrete purpose of this study is to suggest actually a debt ratio to optimize the capital structure providing a kind of approach to estimate the proper debt ratio with an analytical model and empirical data in Korean shipping industry. The mathematical and analytical model is started from the first equation about ROE, return of net operating income on equity, with an independent variable, debt ratio. It is constructed with several parameters, ROS(return of operating income on sales), TAT(total assets turnover), and NFCL(net finance cost to liabilities). There could not be a certain relationship between debt ratio and ROS or TAT, while some correlation or causality between debt ratio and NFCL. In other words, most of firms with high debt ratio is likely to burden higher finance cost than others with low one. In this case, there is a linearity relationship between debt ratio and NFCL, so then the second equation considering this relation could be included within the analytical approach of this paper. To be short, if the criteria of adequate debt ratio has to be defined as some level of debt ratio to optimize ROE, the ROE could be illustrated as a quadratic equation to debt ratio from two equations. Next, this research estimated those parameters' numbers through the single regression method with data over 12 years of Korean shipping industry, and identified empirically the fact that optimal debt ratio would be approximately 400%. To conclude, if that industry's sales and operating incomes are stable, the debt ratio could be accepted until twice of 200% had forced in order to guarantee its financial safety in past time.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.18 no.2
• /
• pp.4096-4104
• /
• 1976

This experiment was carried out to investigate the efficient turning method which will be able to use every cutting methods, to calculate the width of the center field which must transpose from rotary cutting method to return cutting method, to investigate the effects of L/W and unit field on the operation efficiency. The results are summarized as follows: 1. In case of cutting in the outer field, the efficient turning method is the "$\alpha$" type turning method (half U-shaped turning method) at the first rotation, is the "$\beta$" type turning method (T-shaped turning method) at the second to fourth rotation. 2. In case of cutting in the inner field, the efficient turning method which takes the least turning time is the "a" type turning method ($\Delta$-shaped turning method). 3. The width of the center field (W') changes by the length-width ratio (L/W) and width (W), W' is 9.0m in case that L/W is 2.5 and W is 30m. 4. The larger L/W and area of unit field (A) become, the more operation efficiency (E) increases, and the limits that E is affected signicantly by L/W is 2 to 3.5 and A is within 5,000$m^2$. within 5,000$m^2$.

• IE interfaces
• /
• v.11 no.3
• /
• pp.89-101
• /
• 1998

The randomness of the input variables in simulation experiments produce output responses which are also realizations of random variables. The random responses make necessary the use of statistical inferences to adequately describe the stochastic nature of the output. The analysis of the simulation output of non-terminating simulations is frequently complicated by the autocorrelation of the output data and the effect of the initial conditions that produces biased estimates. The regenerative method has been developed to deal with some of the problems created by the random nature of the simulation experiments. It provides a simple solution to some tactical problems and can produce valid statistical results. However, not all processes can he modeled using the regenerative method. Other processes modeled as regenerative may not return to a given demarcating state frequently enough to allow for adequate statistical analysis. This paper shows how the state transformation concept was successfully used in a queueing model and a job shop model. Although the first example can be analyzed using the regenerative method. it has the problem of too few recurrences under certain conditions. The second model has the problem of no recurrences. In both cases, the state transformation increase the frequency of the demarcating state. It was shown that time state transformations are regenerative and produce more cycles than the best typical discrete demarcating state in a given run length.