• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.3
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• pp.183-189
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• 2006

Six japonica and three Tongil type cultivars that were released in different years and planted to a large area during different periods were grown at the experimental farm of Seoul National University in 2001 and compared for traits related to dry matter production and grain yield. The varieties chosen were Jodongji released in 1896, Paldal in 1944, Jinheung in 1962, Nagdong and Tongil (Tonsil type) in 1971, Milyang#23 (Tongil type) in 1976, Hwasung in 1986, Ilpum in 1991, and Dasan (Tonsil type) in 1996. The more recent cultivars tended to have lower canopy light extinction coefficients (K). The K value was 0.601 in the oldest cultivar, Jodongji, and decreased below 0.5 in the cultivars released since 1971. Radiation use efficiency (RUE) was significantly different among cultivars before heading stage, showing no consistent tendency with the year of release and not significantly different after heading. Leaf area duration (LAD) was significantly different among varieties, and LAD values tended to be higher in the more recent cultivars. In particular, this tendency was more obscure in Tongil type cultivars. LAD of whole growth period had a significantly positive correlation with dry matter yield at harvest $(r=0.776^*)$. Dry matters measured at heading and harvest tended to be higher in recently released cultivars, but not significantly. The grain yield of Jodongji was the lowest but there was no significant difference among the other varieties in japonica, while higher yield occurred in the more recent Tongil type. Grain yield was correlated with grain number per square meter, and the more recent Tongil type cultivars had the greater grain number per square meter, In conclusion, not only the dry matter and grain yield but also related traits except K value showed no clear changes when compared with the year of their release in japonica cultivars. However, the increased grain yield in the more recent Tonsil type cultivars might have resulted from the enhanced LAD that lead to the higher dry matter production and in turn to the enlarged sink size.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.536-540
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• 1997

Volatile terpenoids of carrots were measured by the direct headspace sampling method(DHS) with gas chromatography as a study for the breeding of high quality carrots. Using this method, 7 terpenoids such as ${\alpha}-pinene$, ${\beta}-pinene$, ${\beta}-myrcene$, ${\alpha}-terpinene$, limonene, ${\gamma}-terpinene$, and terpinolene were clearly separated. However ${\alpha}-phellandrene$ was not clearly separated from ${\beta}-myrcene$. In addition to this, higher boiling point compounds such as terpinen-4-ol, bornyl acetate, and ${\alpha}-bisbolol$ were not found. The coefficients of $determination(r^2)$ for the 7 terpenoids were higher than 0.99 and the standard curves were highly significant. Four replicated samples using this method demonstrated great reproducibility; the coefficidnt of variation (C.V.) for ${\alpha}-pinene$, ${\beta}-pinene$, ${\beta}-myrcene$, limonene, ${\gamma}-terpinene$, terpinolene, and total terpenoids were 6.8, 6.8, 8.4, 7.1, 3.8, 10.1, 7.1%. Sixty five carrot cultivars breeded worldwide were evaluated for the 7 terpenoids and total terpenoids; the range for ${\alpha}-pinene$, ${\beta}-pinene$, ${\beta}-myrcene$, ${\alpha}-terpinene$, limonene, ${\gamma}-terpinene$, terpinolene, and total terpenoids were $0.28{\sim}2.48\;ppm$, $0.35{\sim}1.87\;ppm$, $0.56{\sim}1.51\;ppm$, 0 ppm, $0.59{\sim}1.84\;ppm$, $0.87{\sim}3.33\;ppm$, $5.15{\sim}35.81\;ppm$, and $9.07{\sim}42.30\;ppm$, respectively. Big differences in each terpenoid and total terpenoids were found among cultivars. On the total terpenoids of the 65 cultivars, 5 cultivars(7.7%) contained less than 10 ppm, 15 cultivars (23.1%) $10{\sim}11.99\;ppm$, 14 cultivars(21.5%) $12{\sim}13.99\;ppm$, 9 cultivars(13.8%) $14{\sim}15.99\;ppm$, 10 cultivars(15.4%) $16{\sim}17.99\;ppm$, 4 cultivars(6.2%) $18{\sim}19.99\;ppm$, 5 cultivars(7.7%) $20{\sim}29.99\;ppm$, and 3 cultivars(4.6%) were higher than 30 ppm. Generally, cultivars developed in Japan contained less total terpenoids than cultivars developed in Europe and America.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.3
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• pp.292-300
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• 2013

In this study, we examine the palatability and physicochemical properties of rice in the year, when there was 10% increase in yield compared to normal year due to daily temperature range and sunshine hours. The results of the analysis of rice yield over the last 20 years (1993-2012) showed 10% difference between the yield in 2000, which was normal, and that in 2001. With regard to the crop weather condition during the ripening period in 2001 compared to 2000, the daily range and sunshine hours were higher, but the mean temperature was similar. The rice yield in 2001 was 9.8% higher than that in 2000 due to the increased number of spikelets per panicles and ratio of ripened grain. In terms of chemical traits, protein, Mg, and K contents decreased in 2001 compared to 2000, but amylose content increased. Trough and final viscosity assessed with a Rapid Visco Analyser were significantly higher in 2001 than 2000. The quality of cooked rice was measured through the Toyo Mido Meter Glossiness Value (TGV) instead of a palatability score because a sensory test produces relative comparison values rather than absolute values. The correlation coefficients between the sensory evaluation parameters and the TGV in several rice materials harvested in two years showed a highly significant positive correlation ($r=0.81^{**}-0.89^{**}$, n=27-47). TGV was also significantly higher in 2001 than in 2000. The results suggested that the palatability of cooked rice was good in 2001 with about 10% increase in rice yield compared to normal year in 2000 due to daily temperature range and sunshine hours.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.3
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• pp.221-232
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• 1999

Dry matter yield and ear percent are commonly considered the most important factors for evaluating silage corn(Zea mays L.) hybrids for silage production. But quality of stover as well as forage production in important in identification of hybrids. The objective of this study was to evaluate nutritional value of stover, ear and whole plant from eight corn hybrids for silage at two dates of planting. In content of fiber components(ADF, NDF, ADL, hemicellulose and cellulose) from stover, ear and whole plant samples, optimum planting corn was lower than late planting one(P<0.01). Differences(P<0.01) in the content of fiber components in stover and whole plant were observed among the corn hybrids. Differences between different planting dates in TDN and $NE_1$ were detected in the stover and whole plant samples(P<0.05). Differences among the corn hybrids in TDN and $NE_1$ were also observed in stover, ear and whole plant samples. TDN and $NE_1$ of 'G4624', 'P3352' and 'P3394' for whole plant were higher than those of the other corn hybrids. ln vitro dry matter digestibility(IVDMD) at optimum planting date was higher than that of late(P<0.05), and there also were significant differences among the corn hybrids. Correlation coefficients for whole plant IVDMD with NDF, ADF, hemicellulose, and cellulose were $-0.82^{**}$, $-0.71^{**}$, $-0.63^{**}$, and $-0.69^{**}$, respectively. Results of this study indicate that optimum planting of corn resulted in increased quality of silage corn. Differences among corn hybrid, particularly, in nutritive value of stover and whole plant were also observed. Therefore, the nutritional value of stover and whole plant may be important in assessing the corn hybrids for silage.

• Korean Journal of Poultry Science
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• v.47 no.3
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• pp.181-188
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• 2020

In this study, sixteen egg quality traits, including egg weight, albumen weight, yolk weight, eggshell weight, albumen weight ratio, yolk weight ratio, eggshell weight ratio, yolk color, eggshell color, egg height, egg width, shape index, albumen height, Haugh unit, eggshell thickness, and eggshell strength were investigated in 12 strains of Korean native chicken using 600 eggs from birds at 38 weeks of age. Results showed that the Korean White Leghorn F strain had the highest egg weight of 62.7 g and the lowest (47.5 g) was observed in the Korean native chicken W strain. The Haugh unit was significantly different between strains. The mean Haugh unit for Korean native chicken ranged between 84.2 (L strain) and 76.0 (F strain), with an overall average of 79.9. Eggshells were the thinnest in Korean Rhode Island Red C and D strains (0.342 mm), whereas the highest eggshell thickness (0.393 mm) was observed in the Korean White Leghorn K strain. Korean Rhode Island Red C and D strains had low egg strength compared to that of other strains. Korean Cornish and Korean native chicken showed significant differences in egg quality traits between strains within breeds. Positive correlation coefficients were observed between egg weight and egg quality traits. The traits for color showed zero or low correlations with most egg quality traits. Egg shape index showed no correlation with most egg quality traits. Albumen height and the Haugh unit showed a positive correlation with albumen traits. Eggshell strength showed a positive correlation with eggshell traits.

• Management & Information Systems Review
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• v.34 no.3
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• pp.17-39
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• 2015

This study examined the structural changes and volatility in the global stock markets using a Markov Regime Switching ARCH model developed by the Hamilton and Susmel (1994). Firstly, the US, Italy and Ireland showed that variance in the high volatility regime was more than five times that in the low volatility, while Korea, Russia, India, and Greece exhibited that variance in the high volatility regime was increased more than eight times that in the low. On average, a jump from regime 1 to regime 2 implied roughly three times increased in risk, while the risk during regime 3 was up to almost thirteen times than during regime 1 over the study period. And Korea, the US, India, Italy showed ARCH(1) and ARCH(2) effects, leverage and asymmetric effects. Secondly, 278 days were estimated in the persistence of low volatility regime, indicating that the mean transition probability between volatilities exhibited the highest long-term persistence in Korea. Thirdly, the coefficients appeared to be unstable structural changes and volatility for the stock markets in Chow tests during the Asian, Global and European financial crisis. In addition, 1-Step prediction error tests showed that stock markets were unstable during the Asian crisis of 1997-1998 except for Russia, and the Global crisis of 2007-2008 except for Korea and the European crisis of 2010-2011 except for Korea, the US, Russia and India. N-Step tests exhibited that most of stock markets were unstable during the Asian and Global crisis. There was little change in the Asian crisis in CUSUM tests, while stock markets were stable until the late 2000s except for some countries. Also there were stable and unstable stock markets mixed across countries in CUSUMSQ test during the crises. Fourthly, I confirmed a close relevance of the volatility between Korea and other countries in the stock markets through the likelihood ratio tests. Accordingly, I have identified the episode or events that generated the high volatility in the stock markets for the financial crisis, and for all seven stock markets the significant switch between the volatility regimes implied a considerable change in the market risk. It appeared that the high stock market volatility was related with business recession at the beginning in 1990s. By closely examining the history of political and economical events in the global countries, I found that the results of Lamoureux and Lastrapes (1990) were consistent with those of this paper, indicating there were the structural changes and volatility during the crises and specificly every high volatility regime in SWARCH-L(3,2) student t-model was accompanied by some important policy changes or financial crises in countries or other critical events in the international economy. The sophisticated nonlinear models are needed to further analysis.

• Journal of Global Scholars of Marketing Science
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• v.20 no.3
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• pp.249-261
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• 2010

As consumers' concern for the environment has continued to increase, many firms have actively engaged in environmental marketing to achieve their objectives. However, consumers' high concerns about the environment are not always reflected in their purchasing behavior. This indicates the need for an in-depth understanding of the development of green consumption within the individual's belief system. In consideration of psychological approaches, a large body of research has examined the factors underlying ecologically conscious "green" consumer behavior and the interrelationships of these factors. However, most previous studies have concentrated on Western countries. Using a sample of Korean consumers, this study attempts to understand the basis of Korean green consumerism and find universal values that are cross-culturally important in guiding consumers' environmental attitudes and behaviors. To this end, this study relates Schwartz's 10 universal values (Schwartz 1992) to environmental behaviors in a hierarchical model of value-attitude-behavior. With reference to the value-attitude-behavior framework, the conceptual model developed for the study explains what motivations can be manifested in Korean consumers' environmental attitudes, and subsequently how the attitudes affect their green choices. Using the pattern of relationships among values that can be related to environmentalism, the first hypothesis holds that there would be particular relationships between motivational value types and environmental attitudes. Hypothesis 2 assumes that environmental attitudes predict environmental behaviors. On the basis of the claim that favorable attitudes toward the environment may be expressed in many different behaviors, the assumption is that consumers' favorable attitudes toward the environment would be linked to a variety of environmental behaviors because people with high environmental attitudes can be more interested in and knowledgeable about environmental actions. Consistent with H2, H3 hypothesizes that there would be a positive relationship between different types of environmental behavior. A total of 564 university students participated in the study. The sample included 308 men, 254 women, and two participants who did not indicate their gender. The average age of the participants was 22.5 years, with a range of 19 to 39. Regarding majors, special efforts were made to draw the participants from different departments of the university. Data were collected by a survey administered via self-completion questionnaires., which assessed the participants' value priorities, environmental attitudes, and behaviors. Path analysis conducted to test the proposed model found the overall fit to be ${\chi}^2$=72.01 (p=0.00), GFI=0.983, CFI=0.982, NFI=0.970, RMR=0.070, and REMSEA=0.050. Thus, most of the fit measures indicated a good fit of the model with the data, and a hierarchical relationship from values to environmental attitudes to environmental non-purchasing behavior to environmental purchasing behavior was confirmed. An assessment of all the predicted paths by path coefficients led to several major hypothesized effects being confirmed. Out of the ten value types, universalism and power were significantly but conversely related to environmental attitudes. In line with the other studies, these findings confirm that environmental attitudes are an important factor in leading to a variety of green behaviors. Finally, significant relationships were found between environmental purchasing and non-purchasing behaviors. The path analysis supported the idea that universalism values provide a motivation for Korean consumers' greenness and indirectly promote environmental acts through favorable attitudes toward the environment. Participants with high environmental attitudes were found to actively engage in diverse forms of green consumer behavior. This research provides an opportunity to examine cross-cultural differences with respect to values leading to environmentalism, and, further, to verify previous findings. The study also examined the attitude-behavior relationship with respect to three distinct types of environmental behaviors. The different strengths of paths between green attitudes and behaviors suggest that researchers should consider the specificity of behavior explained as an effort to improve the low attitude-behavior correlation. Finally, the findings here illustrate that with increased environmental concerns among people, they come to include more such behaviors in their green portfolios.

• Korean Journal of Health Education and Promotion
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• v.26 no.5
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• pp.57-70
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• 2009

Objectives: This purpose of this study was to make clear the fitness to data of the causality model related to father's child-rearing participation in a double-income household. Methods: Subjects of this survey consisted of the fathers of 2,006 households that use 21 day-care centers and 4 kindergartens whose cooperation was received via the city government departments that have jurisdiction over day-care centers and kindergartens in cities A and B in prefecture I and in city C in prefecture II (city A: 499 households; city B: 1,113 households; city C: 988 households). The surveyed items consisted of the father's age, the father's educational history, the number of children, the age of the youngest child, the father's parental-role awareness, the father's daily working hours, the father's return-home time, and child-rearing participation by the father. Results: The fit indices were found to be CFI = 0.912, GFI = 0.948, and RMSEA = 0.082. Regarding the path coefficients, the path coefficient of the pathway from the age of the youngest child to the father's parent positivity (0.08) and the path coefficient of the pathway from the father's parent positivity to child-rearing participation (0.19) were both at statistically significant levels. Also, the father's return-home time and the working hours, which were considered as disincentives exhibited a direct effect on child-rearing participation without being influenced by the father's parent positivity or parent negativity. The path coefficient of the pathway from return-home time to child-rearing participation was -0.43, and the path coefficient of the pathway from working hours to child-rearing participation was -0.13. The value of the path coefficient expressing the relationship between the return-home time and working hours was 0.80. Conclusion: Authors infered that it'll be the basic material to build a generation mechanism about vanity and father's child-rearing participation appropriately as a result of this research.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.296-305
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• 2006

The adsorption and persistence of pencycuron {1-(4-chlorobenzyl) cyclopentyl-3-phenylurea} in soils were investigated under laboratory and field conditions to in order to assess the safety use and environmental impact. In the adsorption rate experiments, a significant power function of relation was found between the adsorbed amount of pencycuron and the shaking time. Within one hour following the shaking, the adsorption amounts in the SCL and the SiCL were 60 and 65% of the maximum adsorption amounts, respectively. The adsorption reached a quasi-equilibrium 12 hours after shaking. The adsorption isotherms followed the Freundlich equation. The coefficient (1/n) indicating adsorption strength and degree of nonlinearity was 1.45 for SCL and 1.68 to SiCL. The adsorption coefficients ($K_d$) were 2.31 for SCL and 2.92 to SiCL, and the organic carbon partition coefficient, $K_{oc}$, was 292.9 in SCL and 200.5 inSiCL. In the laboratory study, the degradation rate of pencycuron in soils followed a first-order kinetic model. The degradation rate was greatly affected by soil temperature. As soil incubation temperature was increased from 12 to $28^{\circ}C$, the residual half life was decreased from 95 to 20 days. Arrhenius activation energy was 57.8 kJ $mol^{-1}$. Furthermore, the soil moisture content affected the degradation rate. The half life in soil with 30 to 70% of field moisture capacity was ranged from 21 to 38 days. The moisture dependence coefficient, B value in the empirical equation was 0.65. In field experiments, the half-life were 26 and 23 days, respectively. The duration for period of 90% degradation was 57 days. The difference between SCL and SiCL soils varied to pencycuron degradation rates were very limited, particularly under the field conditions, even though the characteristics of both soils are varied.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.4
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• pp.100-108
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• 2016

The climatic index for tourism(CIT) has recently been advanced, which includes complete human energy balance models such as physiological equivalent temperature(PET) and universal thermal climate index(UTCI). This study investigated human thermal sensation and comfort at Woljung-ri Beach, Jeju, Republic of Korea, in spring and summer 2015 for landscape planning and design in beach areas. Microclimatic data measurements and human thermal sensation/comfort surveys from ISO 10551 were conducted together. There were 869 adults that participated. As a result, perceptual and thermal preference that consider only physiological aspects had high coefficients of determination($r^2$) with PET in linear regression analyses: 92.8% and 87.6%, respectively. However, affective evaluation, personal acceptability and personal tolerance, which consider both physiological and psychological aspects, had low $r^2s$: 60.0%, 21.1% and 46.4%, respectively. However, the correlations between them and PET were all significant at the 0.01 level. The neutral PET range in perceptual for human thermal sensation was $25{\sim}27^{\circ}C$, but a PET range less or equal to 20% dissatisfaction, which was recommended by ASHRAE Standard 55, could not be achieved in perceptual. Only PET ranges in affective evaluation and personal tolerance affected by both aspects were qualified for the recommendation as $21{\sim}32^{\circ}C$ and $17{\sim}37^{\circ}C$, respectively. Therefore, the PET range of $21{\sim}32^{\circ}C$ is recommended to be used for the human thermal comfort zone of beach areas in landscape planning and design as well as tourism and recreational planning. PET heat stress level ranges on the beach were $2{\sim}5^{\circ}C$ higher than those in inland urban areas of the Republic of Korea. Also, they were similar to high results of tropical areas such as Taiwan and Nigeria, and higher than those of western and middle Europe and Tel Aviv, Israel.