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

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.105-112
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• 2001

This study was carried out to analyze the genetic variation and to estimate both heritabilities and genetic gains for height and diameter growth of 20-year-old open-pollinated progenies of Korean white pine in three different sites. For there, analysis of variance for both height and diameter growth was conducted to see if there exist significant differences among families, sites, blocks, and their interactions exist or not and to analyze the variance components for each factor. Mean height and diameter at Gapyeong site were 7.65m and 11.92cm, respectively. they were 7.42m and 11.35cm at Gwangiu site, 6.13m and 8.41cm at Youngdong site, and 7.12m and 10.68cm for the overall sites. The family No. 20 showed the most excellent growth of 7.99m in mean height and 12.14cm in mean diameter for all sites surveyed. The estimates of heritabilities for individual-tree and family were, 0.35~0.73 and 0.65~0.83 for height growth, and 0.12~0.40 and 0.46~0.75 for diameter growth, respectively. For the combined data from all the sites, the estimates of individual tree heritability were 0.60 for height and 0.20 for diameter, and those of family were 0.91 for height and 0.77 for diameter. Heritability estimates varied with testing sites, and those for height were higher than those for diameter in all sites. Given equal intensity of selection, combined selection method provided the most efficient genetic gains for both height and diameter growth.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.7
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• pp.652-657
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• 2006

Combining ability and heterosis for $F_{1}$ population obtained $5{\times}5$ half diallel cross in sesame were estimated for six quantitative characters. The parental varieties used for diallel cross were Yangbaek and Ansan of normal type, Suwon 177 and 195 of placenta adhesion type (PA) and SIG960320-5-1-1 of indehiscent type (ID). PA and ID type are shattering-resistant sesames and Yangbaek and Ansan are shattering sesames. The high heterosis of $F_{1}$ hybrids was expressed in the number of capsules per plant (NC), grain yield per plant (GY) and number of branches per plant (NB). Shattering.ate (SR) showed high positive heterosis toward increase of seeds shattering in all the combination of $F_{1}$ generation which was presumed because the characters connected with shattering resistance of seeds were governed by recessive gene. At the analysis of combining ability, highly significant general combining ability (GCA) effects were observed on all the characters in $F_{1}$ generation, significant specific combining ability (SCA) effects were observed on the NC, GY and SR. GCA variances were greater than SCA variance, which suggested that additive gene effects were greater than other nonadditive gene effects. Considering the estimated GCA effects, Suwon 195 (PA type) was found to be good parent for SR and GY, SIG960320-5-1-1 (ID type) was poor for GY and plant height. SCA effect for NC was great in Yangbaek/Suwon 195, SCA for GY was great in Ansan/SIG960320-5-1-1, and SCA for decrease of SR was great in Ansan/Suwon177.

• Journal of Korea Port Economic Association
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• v.37 no.4
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• pp.161-173
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• 2021

The shipping industry plummeted and was depressed due to the global economic crisis caused by the bankruptcy of Lehman Brothers in the US in 2008. In 2020, the shipping market also suffered from a collapse in the unstable global economic situation due to the COVID-19 pandemic, but unexpectedly, it changed to an upward trend from the end of 2020, and in 2021, it exceeded the market of the boom period of 2008. According to the Clarksons report published in May 2021, the decrease in cargo volume due to the COVID-19 pandemic in 2020 has returned to the pre-corona level by the end of 2020, and the tramper bulk carrier capacity of 103~104% of the Panamax has been in the ports due to congestion. Earnings across the bulker segments have risen to ten-year highs in recent months. In this study, as factors affecting BDI, the capacity and congestion ratio of Cape and Panamax ships on the supply side, iron ore and coal seaborne tonnge on the demand side and Granger causality test, IRF(Impulse Response Function) and FEVD(Forecast Error Variance Decomposition) were performed using VAR model to analyze the impact on BDI by congestion caused by strengthen quarantine at the port due to the COVID-19 pandemic and the loading and discharging operation delay due to the infection of the stevedore, etc and to predict the shipping market after the pandemic. As a result of the Granger causality test of variables and BDI using time series data from January 2016 to July 2021, causality was found in the Fleet and Congestion variables, and as a result of the Impulse Response Function, Congestion variable was found to have significant at both upper and lower limit of the confidence interval. As a result of the Forecast Error Variance Decomposition, Congestion variable showed an explanatory power upto 25% for the change in BDI. If the congestion in ports decreases after With Corona, it is expected that there is down-risk in the shipping market. The COVID-19 pandemic occurred not from economic factors but from an ecological factor by the pandemic is different from the past economic crisis. It is necessary to analyze from a different point of view than the past economic crisis. This study has meaningful to analyze the causality and explanatory power of Congestion factor by pandemic.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.7
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• pp.942-952
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• 2008

The purpose of this research was to evaluate the quality of take-out services at restaurants in Chungbuk Province. A questionnaire survey by 450 customers who had experience in take-out service at the restaurants was conducted and 378 completed questionnaires were available for statistical evaluation. Statistical analyses were made of raw data by SAS V8.2. The scale for analyzing the importance and performance of the service quality was composed of 5-point Likert scales. The main results of this study are as follow: The quality attributes of take-out service were rearranged into four factors in terms of food, sanitation, access and service. The importance score was higher than performance score. IPA showed that 'freshness of food material', 'cleanliness and hygiene in food', 'sanitation of facilities', 'neatness of employees' and 'price in food' was included in 'focus here' area. There was significantly positive correlation between factors such as food, sanitation, access, service and overall customer satisfaction (p<.001); between factors and repurchasing intentions (p<.001); and between customer satisfaction and repurchasing intentions (p<.001). According to multiple regression analysis, 26.27% of the variance in respondents' overall satisfaction score and 9.21% of the variance in respondents' repurchasing intention score could be explained by factors such as food, sanitation, access and service.

• 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.

• Current Research on Agriculture and Life Sciences
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• v.3
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• pp.158-165
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• 1985

The study was conducted to obtain some genetic information for breeding of mice. Average performance, heterosis and genetic variance were estimated with 362 progenies from a full diallel cross of four lines of mice (BALB/c, CBA, C3H and C57BL). The progenies were reared at the Experimental Animal Farm. College of Agriculture, Kyungpook National University from November, 1984 to February, 1985. Data for litter size. sex ratio, body weight and weaning rate were analyzed into heterosis effects, and genetic variance with Hayman's model. The results obtained are summarized as follows : 1. Average performance was 7.54 in litter size, 53.20 % in sex ratio, 1.55 g in birth weight, 10.45 g in weaning weight and 94.13 % in weaning rate. 2. The estimated heterois was 6.97% in litter size, 7.26 % in sex ratio, 6.08% in birth weight, 3.54% in weaning weight and 2.05% in weaning rate, respectively. 3. Additive gene effects were not observed in litter size, sex ratio, birth weight, weaning weight and weaning rate. In litter size and weaning weight, dominance effects were observed, which were shown due to individual crosses in litter size and were shown mean dominance effects of parental line in weaning weight. Mat-Maternal effects appeared in birth weight and weaning weight, and reciprocal effects were observed in weaning weight.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.395-401
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• 2002

The combination of early heading time, maturing time and short grain-filling period is very important to develop early varieties in winter barley. The 4 parental half diallel crosses (parents, $F_1$s, $F_2$s) were cultivated at the field. The heading date was from April 3 to 26, maturing date from May 15 to 27 and grain-filling period from 31 days to 42 days, showing that the varietal differences about the 3 traits were remarkable. According to half diallel cross analyses, Dongbori 1 for heading time (late heading) was dominant, but Oweolbori (early heading) was recessive, showing partial dominance with high additive component of genetic variance. Dongbori 1 for maturing time was dominant, but Oweolbori was recessive, showing partial dominance with high additive variance. Reno for grain-filling period (short grain-filling period) was dominant, but Oweolbori (long grain-filling period) was recessive with additive, and partial dominance. There were highly significant mean squares for both GCA and SCA effects on the heading and maturing times, and GCA/SCA ratios for all traits were high, showing the additive gene effects more important. Sacheon 6 and Oweolbori had greater GCA effects for early heading and maturing times, and Dongbori 1 and Reno had greater GCA effects for late times. GCA effects were highly significant in $F_1$ and $F_2$ generations, showing high GCA/SCA ratios (7.02). The heading and maturing times in field were positively correlated with antifreeze proteins concentrations, accumulation, resistance to photoinhibition and winter survival, respectively) but the grain-filling period did negatively correlated with the trails.

• 한국노년학
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• v.37 no.1
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• pp.173-200
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• 2017

This study is designed to verify the actual effect on the prevention of the elderly suicide of the integrated crisis intervention service which has been widely provided across all local communities in Gyeonggi-province focusing on the integrated crisis intervention model developed for the prevention of elderly suicide. The integrated crisis intervention model for the local communities and its manual were developed for the prevention of elderly suicide by integrating the crisis intervention theory which contains local community's integrated system approach and the stress vulnerability theory. For the analysis of the effect, the geriatric depression and suicidal ideation scale was adopted and the data was collected as follows; The data was collected from 258 people in the first preliminary test. Then, it was collected from the secondary test of 184 people after the integrated crisis intervention service was performed for 6 months. The third collection of data was made from 124 people after 2 or 3 years later using the backward tracing method. As for the analysis, the researcher used the R Statistics computing to conduct the test equating, and the vertical scaling between measuring points. Then, the researcher conducted descriptive statistics analysis and univariate analysis of variance, and performed multi-level modeling analysis using Bayesian estimation. As a result of the study, it was found out that the integrated crisis intervention model which has been developed for the elderly suicide prevention has a statistically significant effect on the reduction of elderly suicide in terms of elderly depression and suicide ideation in the follow-up measurement after the implementation of crisis intervention rather than in the first preliminary scores. The integrated crisis intervention model for the prevention of elderly suicide was found to be effective to the extent of 0.56 for the reduction of depression and 0.39 for the reduction of suicidal ideation. However, it was found out in the backward tracing test conducted 2-3 years after the first crisis intervention that the improved values returned to its original state, thus showing that the effect of the intervention is not maintained for long. Multilevel analysis was conducted to find out the factors such as the service type(professional counseling, medication, peer counseling), characteristics of the client (sex, age), the characteristics of the counselor(age, career, major) and the interaction between the characteristics of the counselor and intervention which affect depression and suicidal ideation. It was found that only medication can significantly reduce suicidal ideation and that if the counselor's major is counseling, it significantly further reduces suicidal ideation by interacting with professional counseling. Furthermore, as the characteristics of the suicide prevention experts are found to regulate the intervention effect on elderly suicide prevention in applying integrated crisis intervention model, the primary consideration should be given to the counseling ability of these experts.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.1
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• pp.61-69
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• 2009

Statement of problem: Porcelain veneers have become a popular treatment modality for aesthetic anterior prosthesis. Fitting porcelain veneers in the mouth usually involve a try-in appointment, which frequently results in salivary contamination of fitting surfaces. Purpose: An in vitro study was carried out to investigate the effect of silane treatment timing and saliva contamination on the resin bond strength to porcelain veneer surface. Material and methods: Cylindrical test specimens (n=360) and rectangular test specimens (n=5) were prepared for shear bond test and contact angle analysis. Whole cylindrical specimens divided into 20 groups, each of which received a different surface treatment and/or storage condition. The composite resin cement stubs were light-polymerized onto porcelain adherends. The shear bond strengths of cemented stubs were measured after dry storage and thermocycling (3,000 cycles) between 5 and $55^{\circ}C$. The silane and their reactions were chemically monitored by using Fourier Transform Infrared Spectroscopy analysis (FTIR) and contact angle analysis. One-way analysis of variance (ANOVA) and Dunnett's multiple comparison were used to analyze the data. Results: FT-IR analysis showed that salivary contamination and silane treatment timing did not affect the surface interactions of silane. Observed water contact angles were lower on the saliva contaminated porcelain surface and the addition of 37% phosphoric acid for 20 seconds on saliva contaminated porcelain increased the degree of contact angle. Silane applied to the porcelain, a few days before cementation, resulted in increasing the bond strength after thermocycling. Conclusion: Within the limitation of this study, it can be concluded that it would be better to protect porcelain prosthesis before saliva contamination with silane treatment and to clean the contaminated surface by use of phosphoric acid.