• The Korean Journal of Malacology
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• v.30 no.2
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• pp.107-116
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• 2014

Gonadal development and maturation mechanism were studied on the freshwater marsh clam Corbicula papyracea (Heude), which is the endangered species in Korea. The specimens were collected in the rearing ponds and waterway of NFRDI in Gapyeong-gun, Gyeonggi-do from January to December 2004, and then investigated by condition factor, relative growth, gonadal development phases and gonad histological characters based on 30-50 individuals every month. Comparing with the freshwater marsh clam, C. papyracea is small, light olive brown shell and violet interior. The hermaphrodite individuals of C. papyracea take an internal fertilization and fertilized eggs are stored in the foster-sack in the gills, then the hatched juveniles are released outside after an ovoviviparous process. The average water temperature of inhabit area was in range of $1.8-27.0^{\circ}C$ and usually took great effects on the gonad maturation of C. papyracea. The condition factor ranged from 0.14 to 0.21 throughout the year, which was the lowest during winter season (December-February), and gradually increased to the highest value of 0.21 in May. The ratio of meat weight to total weight was 25.9-38.7%, indicating the similar trend with condition factor. The highest values of condition factor and the ratio of meat weight appeared 1-2 months later than gonadosomatic index reached the peak value, it was probably because that the ovoviviparous eggs would spend a long period before hatching from the foster-sack in the gills. To synthesize the characters of meat weight, condition factor and gonad development by histological study, reproductive cycle of C. papyracea could be divided into five successive stages: multiplicative stage (December to February), growing stage (February to May), mature stage (June to August), spawning stage (August to November), recovery stage (November to December). The smallest shell length of matured C. papyracea was 12.6 mm, and individuals, larger than 16 mm, was formed the nursery in the gills.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.38
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• pp.327-376
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• 2008

China is marking 9.4% annual growth rate in average since 1978. GDP reached $1090 in 2003 as the first time and China ranked at 4th with their economy size in 2006. One of the remarkable change in China is the extension of foreign open-door policy. China joined WTO in the end of 2001 and it strengthen the foundation of Chinese market economy structure and encouraged the inflow of foreign capital. While 400 of the 500 global corporations advanced into China, the economy trade has been rapidly increasing between Korea and China. The economy trade in both countries has been regularized since 1992 and the annual trade is tending upwards in last 15 years. Korean trade toward China reached 134,400 million which is increased 27 times compared with the total of 1982. In this period, Korean trade toward China marked 24.5% in Export increasing rate and 16.7% in import increasing rate. China became the 2nd biggest export country of Korea in 2001 and became the top in 2003. As the China foreign direct investment has been increasing rapidly, the number of Korean companies advanced into China has been remarkably increasing. By focusing on a thorough review of the nationally published documents of Korean-Chinese business management research during more than two decades (1981-2004), the present paper has been systematically classified and analyzed the current status of Korean-Chinese business management research. The paper raised some important issues regarding Korean-Chinese business management research and predominantly, its future prospects are outlined. In the paper, the documents which are registered in the Korean Academic Processing Foundation registration of journals and candidate registration of journals have been classified by: research purpose, main subject, research method and the results. Careful analysis among the research clarified the active and inactive business management research fields. This clarification enables us to get a better understanding of the current research of Korean-Chinese business management, and more importantly, it pointed out to the direction of future development of research. In addition, the systematic classification made by this paper may contribute to the decision making of subject index of Korean-Chinese business management research since there has been no classification standard of it until now.

• Journal of Korean Society of Rural Planning
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• v.18 no.2
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• pp.47-56
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• 2012

Recently urban areas have been advanced in the aspects of convenience, traffic, and cultural environments, but they have faced various problems including environmental issues, traffic congestion, and increasing stress. In contrast, rural areas are in charge of various functions, conservations of natural environments and traditional cultures. Rural life style may be beneficial to urbanites. As urbanites are increasingly interested in leisure activities, such as experiences of tradition cultures and education, safe foods and rural tourism are gaining attention as alternative ways of satisfying their desires. In other words, the rural tourism not only provides urbanites with leisure spaces by playing a role in relations between urban and rural areas, but also acts as a nonfarm income to the rural residents. With the changes of time, the number of current rural experience tourism on a nationwide is increasing and competition among locations is getting intensive. Particularly, despite various rural tourism villages in operation, there is not a standard in the dice for experience cost and accommodation costs. Accordingly, the aim of the study was to estimate urbanites' willingness to pay(WTP) for rural experience tourism and to provide basic data for qualitative growth and revitalization with regard to the tours. The estimated WTP for rural experience tourism was found to be 5,600won for experience, 5,600won for food, 42,000won for accommodation, and 13,000won for purchasing farm products, respectively. This trend could be similarly found (there were slight differences in food cost) on all analyses, such as the research of the current situations of rural tourism villages in Gyeongnam province, the pilot survey and the estimation depending on whether or not urbanites experienced the tours. In other words, the WTP for urban hands-on experience tours estimated by this study is considered highly significant in terms with possibility of its application in the sites. It is concluded that the urbanites' WTP for rural experience tourism obtained by this study will contribute to the setup of standard index of rural tourism, the qualitative development of rural hands-on experiences, and the raise of nonfarm income.

• Journal of Energy Engineering
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• v.20 no.1
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• pp.63-76
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• 2011

This paper studies the impact of Korean introduction of the Generalized System of Preferences(GSP) to developing countries, which are continuously arguing to support research and development for reducing greenhouse gas(GHG) emission with developed countries in the Conference of the Parties(COP) of UNFCCC. This paper is focusing on the expecting effects of trade and GHG emission reduction when Korea provides GSP to Indonesia, Brazil, and Ethiopia, which are selected in the first session of Global Green Growth Institute(GGGI). This paper uses the methodology of the intra-industry trade index multiplied by Korean import-induced coefficients. To Indonesia, Korean probable GSP would benefit exports of Indonesian agriculture, forestry, fishery, and livestock farming industries, which would contribute to Indonesian reduction of GHG emission. To Brazil, the exports to Korea would increase in the GHG sensitive industries such as metal, fat, oils, food, and beverage industries. Ethiopia belongs to the least developed countries. So Korean GSP would support the exports and GHG reduction in Ethiopian agriculture, forestry, fisheries, textiles, and leather industries. Without conflicting most favored nation treatment(MFN) principle in WTO, the introduction of GSP would be a good compensation for GHG reduction to developing countries.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.4
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• pp.393-398
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• 2013

Lodging in the direct seeded rice cultivation on flooded paddy is being severe problem due to the lower production and grain quality at ripening stage. This study was conducted to examine the effect of Iprobenfos-metconazole (IPM) treated 50, 40 and 30 days before heading respectively as a plant regulator to reduce the lodging at ripening stage of direct seeding rice cultivation. The culm length treated with IPM, especially the 4th culm internode, was shortened more than with untreated plot, and the most effective time was at 30 days before heading. At 20 days after heading the flag leaves colour showed more greening than in the untreated leaves and the plot with IPM treatment was to be maintained longer compared to the control plot. The Nitrogen concentration of leaves with IPM was lower than in the control plot, and $SiO_2$ contents were higher than in the untreated plot and $SiO_2/N$ ratio was increased more in the IPM plot than in the control plot. The breaking strength of 3rd and 4th culm internode with IPM treatment was higher than in the untreated plot, and the lodging index was reduced in the IPM plot significantly and the field lodging also was reduced. As the results the rice production in the IPM plot was increased more due to be higher ripening ratio and seed grain weight compared to the untreated plot to be occurred the field lodging.

• Korean Journal of Environment and Ecology
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• v.19 no.3
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• pp.258-268
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• 2005

The objective of this study was to monitor the edge vegetation development process after timber harvesting at deciduous hardwood forest in Seoul National University Research Forest of Baekwoonsan (Mt), Korea The results from the 4th (2001) and 5th (2003) survey for edge vegetation development process after timber harvesting are summarized as follows. The competitive species at the harvested forest edge are Lindera erythrocarpa, Weigela subsessilis, Lespedeza maximowiczii, Lindera obtusiioba, Arajia eiata. There were Lindera erythrocarpa, Ivelgela subsessilis, Staphyiea bumaida as competitive species at harvested forest border between harvested forest edge and harvested interior. And at the forest interior, the competitive species were Lindera erythrocarpa, Lindera obtusiloba. There were differences in the competitive species at the forest edge due to the differences in direction, altitude, and existing dominant species. But Lindera erythrocarpa, Weigela subsessilis were appeared to be a competitive specieg at the southwestern slope (A site) and northeastern slope (B site). After timber harvesting, Sasa borealisshowed a good growth in early days, but showed a tendency of declining with the developing of canopy layer And coverage was generally higher at the Northeastern slope (Site B) than southwestern slop (Site A). The similarity index was lower as the distance from the forest edge becomes farther.

• Nutrition Research and Practice
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• v.8 no.6
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• pp.705-712
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• 2014

BACKGROUND/OBJECTIVES: Dietary guidelines for Korean children were released in 2009. The goal of the present study was to examine diet quality in terms of adherence to these dietary guidelines as well as explore the association between guideline adherence and risk of obesity in Korean children. SUBJECTS/METHODS: Children aged 5-11 years (mean age = 8.9 years old, n = 191, 80.6% girls) were recruited from a university hospital in Seoul, Korea. Adherence to dietary guidelines for Korean children was calculated using the Likert scale (1-5), and children were then categorized into low, moderate, and high groups based on adherence scores. Obesity or being overweight was determined based on an age- and gender-specific percentile for body mass index (BMI) of the 2007 Korean National Growth Charts. Diet quality was evaluated from 3 days of dietary intake data. RESULTS: Children in the high adherence group were characterized by significantly lower BMI percentiles and paternal BMIs as well as higher percentages of fathers with a high level of education and higher household incomes compared to those in the low or moderate group. Children in the high adherence group consumed significantly higher amounts of milk and dairy products, were less likely to consume lower than the EAR of phosphorus and iron, and had higher NARs for calcium, phosphorus, iron, zinc, and MAR than those in low groups. The ORs for obesity ($BMI{\geq}95^{th}$ percentile) or being overweight including obesity ($BMI{\geq}85^{th}$ percentile) were significantly lower in the high adherence group compared to the low adherence group (OR: 0.33, 95% CI = 0.13-0.82, P for trend = 0.019; OR: 0.26, 95% CI: 0.11-0.61 P for trend = 0.002). CONCLUSIONS: Korean children who adhered to dietary guidelines displayed better diet quality and a reduced risk of obesity.

• Journal of Distribution Science
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• v.13 no.9
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• pp.37-45
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• 2015

Purpose - This paper's aim is to investigate whether or not gross profitability explains the cross-sectional variation of the stock returns in the Korean stock market. Gross profitability is an alternative profitability measure proposed by Novy-Marx in 2013 to predict cross-sectional variation of stock returns in the US. He shows that the gross profitability adds explanatory power to the Fama-French 3 factor model. Interestingly, gross profitability is negatively correlated with the book-to-market ratio. By confirming the gross profitability premium in the Korean stock market, we may provide some implications regarding the well-known value premium. In addition, our empirical results may provide opportunities for the fund distribution industry to promote brand new styles of funds. Research design, data, and methodology - For our empirical analysis, we collect monthly market prices of all the companies listed on the Korea Composite Stock Price Index (KOSPI) of the Korea Exchanges (KRX). Our sample period covers July1994 to December2014. The data from the company financial statementsare provided by the financial information company WISEfn. First, using Fama-Macbeth cross-sectional regression, we investigate the relation between gross profitability and stock return performance. For robustness in analyzing the performance of the gross profitability strategy, we consider value weighted portfolio returns as well as equally weighted portfolio returns. Next, using Fama-French 3 factor models, we examine whether or not the gross profitability strategy generates excess returns when firmsize and the book-to-market ratio are controlled. Finally, we analyze the effect of firm size and the book-to-market ratio on the gross profitability strategy. Results - First, through the Fama-MacBeth cross-sectional regression, we show that gross profitability has almost the same explanatory power as the book-to-market ratio in explaining the cross-sectional variation of the Korean stock market. Second, we find evidence that gross profitability is a statistically significant variable for explaining cross-sectional stock returns when the size and the value effect are controlled. Third, we show that gross profitability, which is positively correlated with stock returns and firm size, is negatively correlated with the book-to-market ratio. From the perspective of portfolio management, our results imply that since the gross profitability strategy is a distinctive growth strategy, value strategies can be improved by hedging with the gross profitability strategy. Conclusions - Our empirical results confirm the existence of a gross profitability premium in the Korean stock market. From the perspective of the fund distribution industry, the gross profitability portfolio is worthy of attention. Since the value strategy portfolio returns are negatively correlated with the gross profitability strategy portfolio returns, by mixing both portfolios, investors could be better off without additional risk. However, the profitable firms are dissimilar from the value firms (high book-to-market ratio firms); therefore, an alternative factor model including gross profitability may help us understand the economic implications of the well-known anomalies such as value premium, momentum, and low volatility. We reserve these topics for future research.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.1
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• pp.24-29
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• 1984

Seedling yield of panax ginseng depended on soil water in a modified Yang-jig seedbed with rice hull mulch and peat application which increased soil water content. Water dependency tended to increase with the increase of potassium in soil. Effect of potassium on water dependency seemed to be constant in certain range of soil water which might be the optimum water for seedling growth. Partial correlation coefficient between seedling yield and water was significant in relation to organic matter (OM), Mg and Ca. The best multiple regression of seedling yield was with $H_2O$, K and Ca. Available phosphorus (P) in soil increased with low level of peat but decreased with high level or with mulching. There was interaction between mulching and peat for P. There was significant linear relation between two of pH, $H_2O$, Ca, Mg, K, OM except between K and $H_2O$ or pH. Ammonium nitrogen negatively correlated with Mg Quadratic relation held between $NO_3-N$ and K or $NH_4-N$ and between P and K+Ca+Mg. Quadratic relation was more significant than linearity between soil factors. Mulching increased stem length. Leaf area index ranged from 1.06 to 1.67. Leaf area per plant ranged $16.0-18.8cm^2$.

• Korean Journal of Health Education and Promotion
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• v.23 no.5
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• pp.1-11
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• 2006

Objectives: The 2003 WHO/FAO technical report described that Korea has largely maintained its traditional high-vegetable diet despite major social and economic changes, and had lower than expected levels of obesity prevalence than other industrialized countries. However, the prevalence of obesity in Korea has recently been rapidly increasing. The aim of this study was to elucidate the determinants of this rapid growth of obesity prevalence in Korea and to compare the results of national nutrition surveys between Korea and Japan. Methods: The trends of the National Health and Nutrition Survey in Korea instituted every 3 years and that in Japan conducted every year were compared. The results of obesity prevalence defined as more than 25 of the Body Mass Index, the percentage of habitual exercisers and the results of the nutritional surveys were examined from 1992 to 2005 in Korea and from 1992 to 2004 in Japan. Results: The prevalence of obesity in males has been gradually increasing in both Korea and Japan since 1992. Though until 1995 the prevalence of obesity in the Korean male population was less than that in Japan, after 1998 Korea surpassed Japan and a markedly increasing trend was observed. In females, the increasing trend of obesity was slower than males in both Korea and Japan. However, the prevalence of obesity was much higher in Korea compared with that in Japan. The percentage of exercisers was much lower in Korea than in Japan. Although, the definition of an exerciser varies with the survey year in Korea and is different from that in Japan, almost 70% of the population was not regularly engaging in moderate or hard intensity exercise in Korea. From 1995, the total energy intake was increased by 9.8% in Korea but it was decreased by 6.9% in Japan. Presently, the energy intake per capita per day in Korea exceeded that in Japan. Remarkable increases in the intake of meat and poultry, vegetable oils and fats, and milk and dairy products were observed in Korea from 1995 to 2005. On the other hand, these values decreased during the same period in Japan. Conclusion: The prevalence of obesity in Korea is increasing and has surpassed that of Japan. The current trends could be attributed to the low prevalence of habitual exercisers, and an increase in energy intake and the proportion of energy intake from fat.