• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.1000-1007
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• 2005

The aim of the present study was to examine the relationship of maternal factors such as knowledge, attitude and practice of weaning with infant feeding. The subjects were 103 mothers visiting a public health center in Gumi, Kyungbook who filled out self-administered Questionnaires. First of all, about $90\%$ of the participants recognized the importance of complementary foods and proper weaning practices. The response for the recognition of the importance of infant weaning process showed a significant difference by education levels. Concerning an appropriate time for the introduction of weaning foods, $53\%$ of mothers had commenced weaning at age $4\~6$ months, while $38\%$ had done so at age $6\~8$ months. Approximately $76\%$ of mothers fed their babies without the knowledge of age-related weaning method and type of weaning foods. There were no statistical differences in maternal weaning knowledges between levels of education and house income. Mothers with higher levels of education and family income tended to show high perception scores regarding possibility of food allergies caused by baby foods. A demand for reliable sources and education related to nutritious weaning foods and weaning practices were strong in the group with higher education. Knowledge of weaning method and baby foods were obtained by 59 of the 103 mothers from mass media, 35 from friends caring babies, and 9 obtained advice from health professionals or family. Advice from the heath professionals was not the main influence on their decision to introduce weaning foods. Although commercial baby foods are the most commonly used as first weaning foods, those with higher education groups considered commercial baby food are not nutritionally better than home-maid foods. The current findings suggest to us that to improve weaning process, mothers should be educated on the selection and preparation of nutritious, balanced weaning foods and on good weaning practices. It is advised that supportive health professionals from community public health centers should lead the education of infant feeding practices based on maternal characteristics and on basic food and nutritional knowledge.

• Journal of Korean Society of Forest Science
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• v.87 no.4
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• pp.631-641
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• 1998

The objectives of this study were 1) to classify the types of Quercus mongolica stands at Mt. Joongwang and compare their quality, and 2) to determine the proper future tree number of Q. mongolica per ha and the appropriate distance between the future trees. The results from this study were as follows : Q. mongolica stands at Mt. Joongwang was classified into four types, pure Q. mongolica stand as stand type I, Q. mongolica - hardwood stand as stand type II, Q. mongolica - Pines densiflora stand as stand type III, Hardwood - Q. mongolica stand as stand type IV, according to mixture rate in stand volume. Stand type IV showed the best quality stem of Q. mongolica among the stand types, and the stem quality of Q. mongolica in Q. mongolica stand mixed with hardwood as stand types II and IV was better than those in pure Q. mongolica stand as stand type I and in Q. mongolica - P. densiflora stand as stand type III. If the management goal for Q. mongolica stand is to produce its high quality-timber, it is desirable to sustain proper mixture rate of Q. mongolica with another hardwoods. The proper number of future trees in pure Q. mongolica stand as stand type I was 122trees/ha and reasonable distance between the future trees was 9.15m. The distance between future trees in other stand types was 7.2m to 9.3m for stand types II and IV, while 8.0m for stand type III. Thus, the classification of Q. mongolica stand type based on stand character and maturity, and proper stem number of future tree and optimum distance between future trees would be a useful forest tending work.

• 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.

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.26-34
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• 2015

This study was carried out to evaluate the growth characteristics, carbon and nitrogen content of containerized 1-0 Chamaecyparis obtusa seedlings at various levels of fertilizer (2 g/L, 1 g/L, control) and three container volumes (500 mL, 400 mL, 320 mL). The growth of root collar diameter was highest in the 2 g/L (3.14 mm), followed by the 1 g/L (2.75 mm) and control (2.41 mm) treatments, while the height of seedling was significantly higher in the 1 g/L (21.88 cm) than other treatments (2 g/L: 20.92 cm; control: 19.06 cm). The growth of root collar diameter by container volume was better in the 500 mL than in the 320 mL. Dry weight of seedling was the highest in the 1 g/L ($4.41g\;seedling^{-1}$), followed by the control ($3.67g\;seedling^{-1}$) and the 2 g/L ($2.92g\;seedling^{-1}$) treatments. The dry weight of seedlings by container volume was significantly higher in the 500 mL than in the 320 mL. Nitrogen concentration in foliage was ranged from 1.51% in the control to 2.45-2.60% in the fertilizer treatments. However, carbon concentration of seedlings was not affected by the fertilizer or the container volume treatments. The growth of seedlings following planting in mountain area was better in the fertilized seedlings compared with in the unfertilized seedlings. The results indicate that the 1 g/L fertilization was an optimum rate for growth following planting of Chamaecyparis obtusa seedlings.

• Journal of Haehwa Medicine
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• v.9 no.1
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• pp.387-397
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• 2000

Background : Intravascular Laser Irrardiation of Blood(ILIB) is used in disorder of cerebral and peripheral blood circulation, dysfunction of brain, atherosclerosis etc., but there are little study about ILIB in oriental medicine. We wished to assess the efficacy of ILIB for the treatment of cerebral infarction. Method : The study group comprised 40 patients who arrived at hospital during 48 hours after attack. All patient were divided into two group. The control group was treated with Uhuangcheongsimhuan(牛黃淸心丸), Seonghyangjeonggisan(星香正氣散), acupuncture therapy only, while the ILIB group was treated with above therapy plus 5 days of irradiation of He-Ne Laser(1.8~2.5mW, 50min. per day). In rat model of middle cerebral artery(MCA) occlusion, the control group was not treated, while the ILIB group was treated with irradiation of He-Ne Laser(1.8~2.5mW, 24sec.). Result : 1. Symptom improve scores did not showed significant difference between control and ILIB group. 2. Vasoreactivity of carotid siphon did not showed significant difference between control and ILIB group. 3. Vasoreactivity of radial artery did not showed significant difference between control and ILIB group. 4. PT a-PTT did not showed significant changes between before and after treatment in both group. Fibrinogen significantly increased after treatment in ILIB group(p<0.05)), but it was in normal degree. 5. ILIB showed a significant decrease of brain ischemic area and edema in rat model of middle cerebral artery(MCA) occlusion. Conclusion : These findings suggest that additional treatment of ILIB is not more useful than traditional therapy only in acute cerebral infarction. But ILIB showed potential effect in rat model of MCA occlusion. So further investigation will be necessary.

• Korean journal of applied entomology
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• v.47 no.2
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• pp.133-139
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• 2008

This study was performed to investigate the immature development period, fecundity, emergence rate and sex ratio of Sclerodermus harmandi against different host insects, Monochamus alternatus, M. saltuarius and Psacothea hilaris. Full grown larvae and pupae of host insects were provided with foods. The mean larval period of S. harmandi female was $29.2{\pm}0.93\;and\;25.1{\pm}0.47$ days in larvae and pupae of M. alternatus, $27.1{\pm}0.41\;and\;26.0{\pm}0.69$ days in M. saltuarius, and $26.3{\pm}0.38\;and\;31.2{\pm}0.24$ days in P. hilaris, respectively. S. hilaris adults were emerged at $12.9{\pm}0.2$ days in female and $11.9{\pm}0.2$ days in male after pupation when hosted M. alternatus pupa. Development period in male showed shorter one day than in female. Success rate of oviposition against different hosts was higher as 98.6 and 97.5% on full grown larva and pupa of M saltuarius. Emergence rate was higher as 90.1 and 87.3% on M. saltuarius larvae and pupae. Sex ratio of emerged S. harmandi adults was approximately 10:1 (Female : Male), females showed higher emergence rate than males. The period until first oviposition after emergence in S. harmandi female was the shortest in $4.6{\pm}0.1$ days on M. saltuarius pupa. When three females of S. harmandi were inoculated on M. saltuarius larva, the number of laid eggs was the highest $62.7{\pm}2.5$ per female.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.302-311
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• 2018

Using cylindrical paper pot nursery method, three kinds of commercial tomatoes 'Dafnis', 'DOTAERANG DIA' and 'Maescala' were grafted onto a commercial rootstock 'B blocking'. From 10 to 40 days after graft-take, growth traits of seedlings were investigated by 0.5, 1.0 and 2.0S treatments of standard nutrient solution(S) for seedling growth, and top to root ratio(TRR), compactness(CP) and Dickson Quality Index(DQI) were calculated. Two weeks after transplanting of the seedlings under three different night temperature targeting to 10, 15, and $25^{\circ}C$, which were not precisely controlled, the relative growth rate (RGR) was investigated. The quantitative growth traits of grafted seedlings increased with increasing fertilizer concentration, and various range of seedling size could be produced. Compactness and DQI were significantly regressed (Adj $R^2=0.9480$). Short-term RGR after transplanting was higher at 1.0S treatment of standard nutrient solution at the seedling age of 30 days and 40 days after graft-take(DAGT). DQI and RGR were significantly regressed linearly at respective fertigation strength. Specially the diminishing slope of RGR was lower at 1.0S fertigation strength with the increase of DQI than others. The results indicate that DQI could be applied as a quality index of grafted tomato seedlings and the relation analysis between DQI and short-term RGR also could be used to determine the good quality seedlings of grafted tomato grown in cylindrical paper pot.

• Journal of Mushroom
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• v.11 no.3
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• pp.131-136
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• 2013

The effects of fixed and variable relative humidity on fruiting body formation and characters of Pleurotus eryngii were investigated with normal and thinning treatment plots. In fixed relative humidity, as humidity was lower, period of harvest was longer as well as days for pinheading in the both of normal and thinning plots. In the normal plot, qualities of mushroom were 5.5, 5.8, and 6.3 and yield was 98.6 g per bottle for 90% relative humidity, it was best. In the thinning plot, qualities of mushroom were 7.7, 8.4, and 8.5 and yields were 102.1, 105.8, and 116.9 g at 70, 80, and 90% respectively. In variable relative humidity with a thinning plot, the yield of P. eryngii on condition I(>90% for 1 day ${\rightarrow}$ 85% until thinning(for about 11 days) ${\rightarrow}$ 80%) and III(>90% until pin-heading(about for a week) ${\rightarrow}$ 85% until thinning(about for 5 days) ${\rightarrow}$ 80%) were 85.5 and 87.8 g per bottle, and qualities were 7.8 and 8.0 respectively. For long shelf life and a cultural control of bacterial soft rot disease, the condition I will be more largely adopted by mushroom farmers.

• The korean journal of orthodontics
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• v.38 no.4
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• pp.275-282
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• 2008

Objective: The purpose of this study was to investigate the effect of using laser for ceramic bracket bonding of porcelain surfaces and to compare it with conventional treatment of porcelain surfaces. Methods: Ninety feldspathic porcelain specimens were divided into 9 groups of 10, with each group having different surface treatments performed. Surface treatment groups were orthophosphoric acid, orthophosphoric acid with silane, hydrofluoric acid, hydrofluoric acid with silane, sandblasted, sandblasted with silane, laser etched, laser etched with silane, and glazed surface served as a control group. In the laser etched groups, the specimens were irradiated with 2-watt superpulse carbon dioxide ($CO_2$) laser for 20 seconds. Ceramic brackets were bonded with light-cure composite resin and all specimens were stored in water at $37^{\circ}C$ for 24 hours. Shear bond strength was determined in megapascals (MPa) by shear test at 1 mm/minute crosshead speed and the failure pattern was assessed. For statistical analysis, one-way ANOVA and tukey test were used. Results: Statistical analysis showed significant differences between the groups. The HFA + S group showed the highest mean shear bond strength ($13.92{\pm}1.94\;MPa$). This was followed by SB + S ($10.16\;{\pm}\;1.27\;MPa$), HFA ($10.09\;{\pm}\;1.07\;MPa$), L + S ($8.25\;{\pm}\;1.24\;MPa$), L ($7.86\;{\pm}\;0.96\;MPa$), OFA + S ($7.22\;{\pm}\;1.09\;MPa$), SB ($3.41\;{\pm}\;0.37\;MPa$), OFA ($2.81\;{\pm}\;0.37\;MPa$), G ($2.46\;{\pm}\;1.36\;MPa$), Bond failure patterns of HFA and silane groups, except L + S, were cohesive modes in porcelain while adhesive failure was observed in the control group and the rest of the groups. Conclusions : A 2-watt superpulse $CO_2$ laser etching of porcelain surfaces can provide a satisfactory result for porcelain surface treatment for ceramic bracket bonding. Laser irradiation may be an alternative conditioning method for the treatment of porcelain surfaces.

• 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.