• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.6
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• pp.449-456
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• 2021

In this paper, we present a strategy to extend solution capability of an existing low Mach number preconditioned compressible solver to incompressible flows with a little modification. To this end, the energy equation that is of the same form of the total energy equation of compressible flows is used. The energy equation is obtained by a linear combination of the thermal energy equation, the continuity equation and the mechanical energy equation. Subsequently, a modified artificial compressibility method in conjunction with a time marching technique is applied to these incompressible governing equations for steady flow solutions. It is found that the Roe average of the common governing equations is equally valid for both the compressible and incompressible flow conditions. The extension of an existing compressible solver to incompressible flows does not affect the original compressible flow analysis. Validity for incompressible flow analysis of the extended solver is examined for various inviscid, laminar and turbulent flows.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.187-194
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• 2005

For the analysis of compressible multi-phase and real gas flows, characteristic form of Roe's Riemann solver was derived using real gas equation of state. It was extended to multi component reactive system considering variable specific heat. From this study, it is known that some correction should be made for the use of existing numerical algorithm. 1) Sonic speed and characteristic variable should be corrected with real gas effect. 2) Roe's average was applicable only with the assumption of constant properties. 3) Artificial damping term and characteristic variables should be corrected but their influences may not be significant.

• Animal Systematics, Evolution and Diversity
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• v.16 no.2
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• pp.169-176
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• 2000

As one of researches to clarify the taxonomic status of roe deer from Jeju island (C. pygargus tianschanicus), we analyzed partial sequences of mtDNA cytochrome b gene from six roe deers at Jeju island in Korea. Maximum nucleotide Tamura & Nei's distance among three haplotypes was 0.005, and this distance was comparable to the diversity within other roe deer subspecies: it is suggested that roe deers from the mainland dispersed rarely to Jejudo Island, although further analyses are ne-cessary to decide whether or not it was occurred by human introduction. Furthermore, nucleotide distance between cytochrome b sequences of roe deers from Jeju (C. pygargus tianschanicus) and the sequence of roe deer from west Siberia(C. p. pygargus), obtained from GenBank, was average 0.013, and it is suggested that C. p. tianschanicus diverged from C. p. pygargus of west Siberia 0.65 Myr ago.

• Korean Journal of Food Science and Technology
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• v.21 no.2
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• pp.242-251
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• 1989

The salted-dried mullet(Mugil japonicus) roe is a kind of traditional food particulary in the area of Young-am gun, Chunnam province. This study was conducted to conform the scientific processing conditions and to evaluate the nutritional quality and changes of major components during storage times. The manufacturing method was that the fresh roe was salted for about 20 hours for the preparation of salted-dried roe, washed by clean waters, drained, shaped a flat piece with 1.2cm thickness by pressing, and spreaded sesame oils on the surface of the salted roe periodically during wind drying for 20 days. The dried roe was blanched in heated water$(80^{\circ}C/3min)$ and packaged the dried product for storages. The fractional compositions of free lipid of wind dried roe were 40% of neutral lipids, 12% of glycolipids and 9% of phospholipids and those of bound lipids were 13% of neutral lipids. 10% of glycolipids and 13% of phospholipids respectively. The major fatty acids of the roe were $C_{16:0}$, $C_{18:0}$, $C_{18:1}$, $C_{18:2}$ and $C_{20:0}$ which was consisted of free and bound lipids in wind drying method during processing and storages. Total amino acids were 99.87g/100g and major amino acids were Glu, Pro, Leu, Lys and CySH and the protein score was average 155% and the chemical score was average 109%. Free amino acids was 1,376mg% that had 50.61% of Pro and the major kinds of those were Tyr and CySH.

• 한국전산유체공학회:학술대회논문집
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• 2000.05a
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• pp.153-158
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• 2000

For the analysis of compressible flow with real gas effect, characteristic form of Roe's Riemann solver was derived again using real gas equation of state and variable specific heal and it was extended to multi component reactive system. From this study, it is known that some correction should be made for the use of existing numerical algorithm. 1) Sonic speed and characteristic variable should be corrected with real gas effect. 2) Roe's average was applicable only with the assumption of constant properties. 3) Artificial damping term and characteristic variables should be corrected but their influence may not be significant.

• Korea Journal of Hospital Management
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• v.2 no.1
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• pp.80-95
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• 1997

It has been an issue in the field of hospital management to develope a systematic and comprehensive analysis frame for financial position. This study developed a return on equity(ROE) model that includes the components of financial profitability, activity, stability and growth with reference to that developed in the USA The application of the model was attempted to assess its feasibility using data collected from a general hospital that has long been in the red. The hospital's financial ratio were compared to those of another private hospital in the black and also to the average ratios values of the similar bed-sized hospitals. Factors that cause the financial deficit and the strategies that can help to reorient the management's financial decision-making together with requisite conditions for effective use of the model, were identified. This study concludes that the ROE model can be usefull when effective financial strategies of the private hospitals are to be formulated.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.4
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• pp.213-228
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• 2022

This paper investigates the association between key corporate governance characteristics and the performance of general insurance businesses listed on the Saudi stock exchange (TADAWUL). The methodology for the study is based on a pooled data collection for 11 Saudi general insurance companies from 2011 to 20. The linear regression model and the logarithm regression model are suggested to assess the relationship between performance and corporate governance characteristics. The dependent variable is firm performance measured using ROA, ROE, and Tobin's Q. The independent variables are corporate governance variables consisting of a complete set of board and audit committee characteristics. Insurer-specific control variables are introduced. The empirical results reveal that the characteristics of corporate governance influence the performance of insurance companies. In particular, the board size, board's tenure, the proportion of independent directors in the board, audit committee size, audit committee meeting frequency, and proportion of health insurance premiums have a positive impact. However, audit committee independence, size of the company, and proportion of reinsurance premiums have a negative impact on the performance of the Saudi general insurance companies. Finally, the empirical results indicated also that there is an unclear relationship between the performance and board meeting frequency, compensations of the Board, and the average age of the Board.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.8
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• pp.75-83
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• 2021

For many years, many academics and practitioners have paid attention to the increasing popularity of corporate social responsibility (CSR) and its relationship with financial performance. They have shown that creating social and sustainable responsibility can strengthen the organization's financial performance as the organization can achieve its current needs without compromising the ability to meet future needs. While much theoretical and empirical evidence has been provided to support this argument in developed countries, this topic is under-researched, and the outcomes are controversial in developing countries. Therefore, this paper aims to examine and investigate the relationship between corporate social responsibility and financial performance in Vietnamese organizations. The dataset includes 27 firms listed on the stock market exchanges in Ho Chi Minh city (HOSE) and Hanoi (HNX) from 2015 to 2019. The disclosure approach is adopted to measure corporate social activities; four areas were developed: environment, community, employee and product, customer, and supplier practices. Return on average equity (ROE) and return on average assets (ROA) are two proxies for measuring financial performance. The research results confirm the existing literature with a strong correlation between employees and returns on average assets.

• Journal of the Korea Convergence Society
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• v.9 no.7
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• pp.213-222
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• 2018

This study attempts to empirically investigate the excess returns of growth stocks in the Korean stock market comparing with those of value stocks. Recently, a few of IT and bio-pharmaceutical stocks with high growth potentials have accomplished dramatically high returns in the Korean stock market. Whereas, important prior studies in this line have observed negative excess returns from investment of growth stocks on average. And a few studies have reported that the distribution of excess returns from growth stocks is not normal but positively skewed. Empirical results of the present study are consistent with those of prior studies. Interestingly, the present study observed serial inverse correlation between excess returns of growth stocks and value stocks. Also, regardless of growth or value stocks, the stocks with higher PEG(=PER/ROE) showed higher excess returns.

• Korea Trade Review
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• v.41 no.1
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• pp.67-90
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• 2016

This study examines whether there is any significant relation between executive compensation and future firm performance for the Korean export manufacturing small and medium-sized firms. We sorted the whole sample firms into the sub-groups of 10 deciles by firm size and the KSIC standard. We found the following empirical results. First, Korean export manufacturing small and medium-sized firms typically showed lower or even negative profitability in terms of return on equity and operating profit ratio to sales. Foreign equity ownership is very low with an average of 3.77%. Second, for the firms with higher ratio of excess executive compensation to asset had lower future firm performance. It implies that the typical owner-manager in Korean export manufacturing SMEs earns excess pay, but do not contribute much to firm performance. Third, as for future cumulative abnormal returns for future one- and three-year periods, firms with higher owner-executive pay had lower returns compared with firms with lower pay. So the stock market investors set a lower value on them. Fourth, there is a positive relation between excess executive pay and executive overconfidence, and it implies that owner-CEOs with higher pay may become overconfident, thereby lowering future firm performance somehow.