• The Korean Journal of Financial Studies
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• v.3 no.1
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• pp.233-265
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• 1996

We examine the impact of public and private information on price movements using the thirty DJIA stocks and twenty-one NASDAQ stocks. We find that the standard deviation of daily returns on information days (dividend announcement, earnings announcement, insider purchase, or insider sale) is much higher than on no-information days. Both public information matters at the NYSE, probably due to masked identification of insiders. Earnings announcement has the greatest impact for both DJIA and NASDAQ stocks, and there is some evidence of positive impact of insider asle on return volatility of NASDAQ stocks. There has been considerable debate, e.g., French and Roll (1986), over whether market volatility is due to public information or private information-the latter gathered through costly search and only revealed through trading. Public information is composed of (1) marketwide public information such as regularly scheduled federal economic announcements (e.g., employment, GNP, leading indicators) and (2) company-specific public information such as dividend and earnings announcements. Policy makers and corporate insiders have a better access to marketwide private information (e.g., a new monetary policy decision made in the Federal Reserve Board meeting) and company-specific private information, respectively, compated to the general public. Ederington and Lee (1993) show that marketwide public information accounts for most of the observed volatility patterns in interest rate and foreign exchange futures markets. Company-specific public information is explored by Patell and Wolfson (1984) and Jennings and Starks (1985). They show that dividend and earnings announcements induce higher than normal volatility in equity prices. Kyle (1985), Admati and Pfleiderer (1988), Barclay, Litzenberger and Warner (1990), Foster and Viswanathan (1990), Back (1992), and Barclay and Warner (1993) show that the private information help by informed traders and revealed through trading influences market volatility. Cornell and Sirri (1992)' and Meulbroek (1992) investigate the actual insider trading activities in a tender offer case and the prosecuted illegal trading cased, respectively. This paper examines the aggregate and individual impact of marketwide information, company-specific public information, and company-specific private information on equity prices. Specifically, we use the thirty common stocks in the Dow Jones Industrial Average (DJIA) and twenty one National Association of Securities Dealers Automated Quotations (NASDAQ) common stocks to examine how their prices react to information. Marketwide information (public and private) is estimated by the movement in the Standard and Poors (S & P) 500 Index price for the DJIA stocks and the movement in the NASDAQ Composite Index price for the NASDAQ stocks. Divedend and earnings announcements are used as a subset of company-specific public information. The trading activity of corporate insiders (major corporate officers, members of the board of directors, and owners of at least 10 percent of any equity class) with an access to private information can be cannot legally trade on private information. Therefore, most insider transactions are not necessarily based on private information. Nevertheless, we hypothesize that market participants observe how insiders trade in order to infer any information that they cannot possess because insiders tend to buy (sell) when they have good (bad) information about their company. For example, Damodaran and Liu (1993) show that insiders of real estate investment trusts buy (sell) after they receive favorable (unfavorable) appraisal news before the information in these appraisals is released to the public. Price discovery in a competitive multiple-dealership market (NASDAQ) would be different from that in a monopolistic specialist system (NYSE). Consequently, we hypothesize that NASDAQ stocks are affected more by private information (or more precisely, insider trading) than the DJIA stocks. In the next section, we describe our choices of the fifty-one stocks and the public and private information set. We also discuss institutional differences between the NYSE and the NASDAQ market. In Section II, we examine the implications of public and private information for the volatility of daily returns of each stock. In Section III, we turn to the question of the relative importance of individual elements of our information set. Further analysis of the five DJIA stocks and the four NASDAQ stocks that are most sensitive to earnings announcements is given in Section IV, and our results are summarized in Section V.

• Tuberculosis and Respiratory Diseases
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• v.55 no.4
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• pp.378-387
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• 2003

Background : Promoter methylation of tumor suppressor genes is one of the key epigenetic changes in many human cancers. The aim of this study was to evaluate the promoter methylation status of the Death-associated protein(DAP) kinase gene, which played an important role in lung cancer, in the serum DNA of primary lung cancer patients. Methods : This study investigated the aberrant methylation of DAP kinase in the serum of 65 primary lung cancer patients by methylation-specific PCR (MSP). Results : Methylation in the serum was detected in 29 of 65(44.6%) for DAP kinase. There was no statistical association between methylation of DAP kinase and age, smoking history, histologic type, or stage. Methylation of DAP kinase was found more frequently in men (p=0.044). Conclusions : This study suggests that the aberrant methylation of the DAP kinase promoter is readily detectable in the serum DNA of lung cancer patients using MSP analysis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.1077-1081
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• 2005

The objective of this study was to investigate the components and nutritional quality of red-tanner crab (Chionoecetes japonicus) paste in order to explore possibility for food processing source such as surimi gel containing crab paste. Yield of crab paste was $30\%$ from whole body after crushing and dehydrating. Crude protein contents $(9.5\%)$ of crab paste was lower than that $(13.1\%)$ of crab muscle, but fat $(0.5\%)$ and ash contents $(8.0\%)$ of paste were higher than $0.2\%\;and\;1.3\%$ of crab muscle, respectively. Volatile basic nitrogen (VBN) content of the crab paste was lower than those of the edible parts. Total amino acid content (9,497mg/l00g) of paste was lower than that (12,980mg/100g) of muscle. Aspartic acid, glutamic acid, lysine and leucine were the predominant amino acids in the protein fraction. The calcium content (6,539mg/l00g) was higher than those of phosphorus (579mg/100g), and potassium (793mg/100g) while manganese and iron were present in trace amounts. Major fatty acids of total lipid were 16:0, 18:1n-9, 20:5n-3 and 22:6n-3, and no difference of composition between paste and muscle. Sensory evaluation showed that scores of color and flavor of $15\%$ substituted surimi gel increased significantly when compared to surimi gel without crab paste (p<0.05). From the above results, the addition of crab paste enhanced nutrition and functionality of surimi gel.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.357-361
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• 2008

In this study, the antioxidant properties and physical characteristics of irradiated Sargassum siliquastrum water extract were evaluated. Samples were irradiated with $Co^{60}{\gamma}$-ray at doses ranging from 3 to 20 kGy. They were then analyzed to investigate antioxidant properties, including total phenolic compound content and DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity. In addition, physical properties such as viscosity and color were evaluated. The results demonstrated that total phenolic compound content and DPPH radical scavenging activity were significantly improved (p<0.05) by irradiation. In terms of physical properties, viscosity and color were reduced in the irradiated extracts as compared to non-irradiated samples. In conclusion, gamma irradiation improved the antioxidant properties of Sargassum siliquastrum water extract, improving its original weak point as a natural antioxidant when applied in the food industry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.348-356
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• 2008

For the effective use of rainbow trout, the seasoned and dried rainbow trout slice (SR) was prepared and its characterization was compared with the commercial skipjack tuna (CSS) and pork products (CSP) by determining chemical components and sensory evaluation. The moisture content of SR, 20.5%, was lower, and the lipid content of SR, 7.5%, was higher than those of commercial products, CSS and CSP. The protein content of SR (41.4%) was higher than that of CSS (28.6%), but lower than that of CSP (50.1%). The water activity of SR was 0.654, which was lower than those of CSS and CSP, 0.724 and 0.771, respectively. According to the results, the color of SR was lower in lightness and redness and higher in browning index and ${\Delta}$E value than that of commercial products. The texture of SR was harder than that of CSS, but softer than that of CSP. According to the result of taste value, the taste of SR was stronger than that of CSP, while weaker than that of CSS. The mineral (Ca, P, and Fe), total amino acid contents, and the n-3/n-6 of SR showed significant levels in nutrition and health functional senses.

• Journal of Intelligence and Information Systems
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• v.22 no.4
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• pp.177-192
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• 2016

Machine learning is a field of artificial intelligence. It refers to an area of computer science related to providing machines the ability to perform their own data analysis, decision making and forecasting. For example, one of the representative machine learning models is artificial neural network, which is a statistical learning algorithm inspired by the neural network structure of biology. In addition, there are other machine learning models such as decision tree model, naive bayes model and SVM(support vector machine) model. Among the machine learning models, we use SVM model in this study because it is mainly used for classification and regression analysis that fits well to our study. The core principle of SVM is to find a reasonable hyperplane that distinguishes different group in the data space. Given information about the data in any two groups, the SVM model judges to which group the new data belongs based on the hyperplane obtained from the given data set. Thus, the more the amount of meaningful data, the better the machine learning ability. In recent years, many financial experts have focused on machine learning, seeing the possibility of combining with machine learning and the financial field where vast amounts of financial data exist. Machine learning techniques have been proved to be powerful in describing the non-stationary and chaotic stock price dynamics. A lot of researches have been successfully conducted on forecasting of stock prices using machine learning algorithms. Recently, financial companies have begun to provide Robo-Advisor service, a compound word of Robot and Advisor, which can perform various financial tasks through advanced algorithms using rapidly changing huge amount of data. Robo-Adviser's main task is to advise the investors about the investor's personal investment propensity and to provide the service to manage the portfolio automatically. In this study, we propose a method of forecasting the Korean volatility index, VKOSPI, using the SVM model, which is one of the machine learning methods, and applying it to real option trading to increase the trading performance. VKOSPI is a measure of the future volatility of the KOSPI 200 index based on KOSPI 200 index option prices. VKOSPI is similar to the VIX index, which is based on S&P 500 option price in the United States. The Korea Exchange(KRX) calculates and announce the real-time VKOSPI index. VKOSPI is the same as the usual volatility and affects the option prices. The direction of VKOSPI and option prices show positive relation regardless of the option type (call and put options with various striking prices). If the volatility increases, all of the call and put option premium increases because the probability of the option's exercise possibility increases. The investor can know the rising value of the option price with respect to the volatility rising value in real time through Vega, a Black-Scholes's measurement index of an option's sensitivity to changes in the volatility. Therefore, accurate forecasting of VKOSPI movements is one of the important factors that can generate profit in option trading. In this study, we verified through real option data that the accurate forecast of VKOSPI is able to make a big profit in real option trading. To the best of our knowledge, there have been no studies on the idea of predicting the direction of VKOSPI based on machine learning and introducing the idea of applying it to actual option trading. In this study predicted daily VKOSPI changes through SVM model and then made intraday option strangle position, which gives profit as option prices reduce, only when VKOSPI is expected to decline during daytime. We analyzed the results and tested whether it is applicable to real option trading based on SVM's prediction. The results showed the prediction accuracy of VKOSPI was 57.83% on average, and the number of position entry times was 43.2 times, which is less than half of the benchmark (100 times). A small number of trading is an indicator of trading efficiency. In addition, the experiment proved that the trading performance was significantly higher than the benchmark.

• Korean Journal of Environment and Ecology
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• v.26 no.1
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• pp.39-45
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• 2012

To explore on the defense strategies against hervivory of 67 broadleaved tree species, morphological characteristics of the leaf, leaf domatia structure and the number, herbivores insects and mites on the leaves, collected from the trees growing in Taean-gun, Chuncheongnam-do were investigated. 46 broadleaved tree species(68.7%) had the domatia structures, and 21 species including Quercus salicina and Magnolia grandiflora did not. 31 species including Juglans mandshurica and Carpinus laxiflora reveals tuft type, 12 species including Quercus dentata and Corylus heterophylla reveals pocket+tuft type, and 2 species, Sorbus alnifolia and Prunus yedoensis does pocket type, and Viburnum odoratissimum var. awabuki does pouch type. Domatia number per leaf proves the highest figures, 23.4/leaf for Quercus dentata. Plant defense strategies using leaf lower-surface trichomes of Magnolia grandiflora reveals dense villous, those of Populus alba and Vitis vinifera reveals dense pilose, that of Elaeagnus umbellata does dense scaly hairs, that of Pueraria lobata does dense strigose. Plant defense strategies using extrafloral nectaries were adapted 23 tree species(34.3%). Observed examples are Prunus tomentosa, Ficus carica, Viburnum dilatatum and Carpinus laxiflora. Predatory mites were observed on the leaves of 40 tree species(59.7%), and mean values of predatory mites was highest values 23.4/leaf in Quercus dentata. Minute arthropods destroying the leaf of broadleaved trees. are such as Periphyllus californiensis, P. viridis, Diaspididae sp., gall mites, thrips, and total numbers observed were odered gall mites, Diaspididae sp., aphids and thrips. Natural enemies of these hervivores arthropods are such as predatory mites, Chilocorus rubidus, Coccinella septempunctata and the nymph, Aphidius ervi. These results indicate that defense strategies including protective mutualisms may be frequent in the temperate broadleave trees.

• Journal of Ginseng Research
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• v.31 no.4
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• pp.181-190
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• 2007

Compound K (CK), a protopanaxadiol ginsenoside metabolite, was previously shown to have immunomodulatory effects. In this study, we isolated the CK rich fractions (CKRF) from Korean Red Ginseng and investigated the regulation of CKRF-mediated inflammatory signaling during Toll-like receptor (TLR)-mediated cellular activation. Among various TLR ligands, CKRF considerably abrogated TLR4- or TLR9-induced inflammatory signaling. Both LPS and CpG-containing oligodeoxynucleotides (CpG-ODN) stimulation rapidly activates mitogen-activated protein kinases [MAPKs; extracellular signal-regulated kinases 1/2 and p38], NF-${\kappa}B$, and expression of pro-inflammatory cytokines tumor necrosis factor-${\alpha}$, and interleukin-6 in murine bone marrow-derived macrophages (BMDMs) in a time- and dose-dependent manner. Of interest, pre-treatment of CKRF in either LPS/TLR4- or CpG-ODN/TLR9-stimulated macrophages substantially attenuated the LPS-induced inflammatory cytokine production and mRNA expressions, as well as MAPK and NF-${\kappa}B$ activation. To our knowledge, this is the first description of the inhibitory roles for CKRF in TLR4- or TLR9-associated signaling in BMDMs. Collectively, these results demonstrate that CKRF specifically modulates distinct TLR4 and TLR9-mediated inflammatory responses, and further studies are urgently needed for their in vivo roles for potential therapeutic uses, such as in systemic inflammatory syndromes.

• Journal of agricultural medicine and community health
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• v.36 no.4
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• pp.238-250
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• 2011

Objectives: This study was performed to investigate the service needs of the beneficiaries who had enrolled in home-based management programs for cancer patients. Methods: From March to May 2009, 676 cancer patients who were registered in home-based cancer patient management programs were selected as subjects for this study. The data were collected using a questionnaire along with a face-to-face interview performed by officers in charge of the home-based care programs of 47 regional health centers. Fifteen patients were excluded due to incomplete data, leaving 661 subjects who were ultimately enrolled in the study. Results: The mean age of subjects was $64.0{\pm}2.5$ years, and males comprised 45.1% (298/661) of the sample. The results of factor analysis for service needs showed that there were five main categories and Cronbach's alpha ranged from 0.593 to 0.890 for each factor. The service needs categories in order of importance were social support, information and education, psychological problems, physical symptoms and household chores. The service needs scores were significantly different when subjects were stratified by age, habitation, religion and disease classification. When we divided the subjects into complete remission, under treatment and terminally ill groups, the needs scores of the terminally ill patient group were significantly higher than those of the other groups (p<0.001). Conclusions: Service provision based on patient and beneficiary needs could be an effective intervention to reduce the economic burden of cancer management and to improve the quality of life of cancer patients receiving home-based care. Therefore, it is recommended that individual cancer patient care programs be developed and administered according to patient age, habitation and disease severity.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.1
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• pp.1-7
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• 2010

Purpose: The purpose of this study was to evaluate the fit of zirconia core using MAD/MAM system comparing to that of conventional metal-ceramic and CAD/CAM system. Materials and methods: Duplicating the prepared resin tooth, 50 improved stone dies were fabricated. These dies are classified as a group of 5 to create the core. The groups were composed of metal-ceramic, $Cercon^{(R)}$, $Ceramill^{(R)}$, $Rainbow^{TM}$, and $Zirkonzhan^{(R)}$. Each core was cemented to stone die, and then, absolute marginal discrepancy was measured with microscope at a magnification of ${\times}50$. Statistical analysis was done with one-way ANOVA test and Tukey's HSD test. Results: The mean absolute marginal discrepancy for metal-ceramic was $51.97{\pm}23.38{\mu}m$, for $Cercon^{(R)}$ was $62.16{\pm}25.88{\mu}m$, for $Ceramill^{(R)}$ was $67.64{\pm}40.38{\mu}m$, for $Rainbow^{TM}$ was $125.07{\pm}42.19{\mu}m$, and for $Zirkonzhan^{(R)}$ was $105{\pm}44.61{\mu}m$. Conclusion: 1. Fit of margin was identified as in the order of metal-ceramic, $Cercon^{(R)}$, $Ceramill^{(R)}$, $Zirkonzhan^{(R)}$, and $Rainbow^{TM}$. 2. Absolute marginal discrepancy of the zirconia core that designed by MAD/MAM system had significant differences in order of $Ceramill^{(R)}$, $Zirkonzhan^{(R)}$, and $Rainbow^{TM}$. 3. The mean absolute marginal discrepancy between $Cercon^{(R)}$ and $Ceramill^{(R)}$ did not show significant differences.