• Korean Journal of Agricultural Science
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• v.2 no.2
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• pp.357-373
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• 1975

This study was conducted to evaluate the winter active polycross progenies of 10 genotypes selected at the hot and dry climate of the Southern Oregon in their performance in the progeny test comparing with a high yielding variety, 'Fawn', and a winter active variety, 'TFM', as the control varieties at Daejon, Korea. Various plant and leaf characteristics, especially which related to photosynthesis, and forage production during the first summer after their establishment, were examined. The important conclusions of this study are summarized as follows: 1. The winter active genotypes and variety had less leaf fresh weight and dry weight per leaf than variety 'Fawn'. Variations among polycross progenies of genotypes for these characteristics were great. 2. The winter active genotypes and variety had less leaf area per leaf than variety 'Fawn'. Leaf area among polycross progenies of genotypes deviated greatly and poly cross progenies of 'genotype-16' had the same average leaf area as 'Fawn'. 3. Differences of specific leaf weight (S. L. W.) in the winter active genotypes and variety were not significant. Probably the genetic diversity for S. L. W were not big and were narrowed down already in this genetic population. It was suggested that the photosynthate production within the population might not be different and there might be differences in the photosynthate production-translocation balance. Further study for the diurnal change in S. L. W. within the population might be useful. 4. The winter active variety and genotypes had less leaf width than 'Fawn' does. Leaf width among polycross progenies of genotypes deviated significantly. 5. Differences among controls and polycross progeny group in the initial plant height were significant and variety 'Fawn' was taller than the winter active genotypes and variety. But the differences were not significant in the regrowth of plant height after the first forage harvest. On the contrary. the differences among polycross progenies of genotypes were not significant in the initial plant but the differences in their polycross progeny performance became obvious and great in the regrowth ability which is an improtent agronomic characteristics for forage crops produced in the pasture and for hay and silage. 6. Plant width of the winter active genotypes and variety was lesser than 'Fawn' variety. 7. Differences of tiller number became evident and variety 'Fawn' had higher tiller number than the winter active genotypes and variety after the first forage cutting. There, deviations among polycross progenies of genotypes were great for this characteristic. It was obvious that the genetic differences became more evident in the second measurement after the first cutting of forage probably because this characteristic were stimulated by defoliation in the cartain genotypes and variety. 8. The winter active genotypes and variety on the initial growth. the regrowth ability andtotal yield had lesser forage yield than variety 'Fawn'. Deviation of forage yield among polycross progenies of genotypes were great and gave basis for selection according to their polycross progeny performance improving the forage yield of these winter active tall fescue population during summer. 9. It was concluded that the winter active variety and genotypes in this study was poorer than variety 'Fawn' for the most of leaf and plant characteristics including forage yield. For these measurements, the variations among polycross progenies of genotypes were great. and plant breeding might able to improve further this winter active tall fescue through the polycross progeny testing method for the higher forage production during summer in Korea. 10. The result of the associations among various characteristics under study were quite agreeable with the results of the analysis of variance and woul be useful in the selection of desirable genotypes for the development of a new variety.

• Korean Journal of Agricultural Science
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• v.2 no.2
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• pp.341-356
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• 1975

This study was carried out to evaluate three winter active synthetic varieties in a succeeding generations of improvement and polycross progenies of seven genotypes selected at the cool and wet climate of the Western Oregon, in their performance of the polycross progeny test comparing with a control variety, high yielding 'Fawn', at Daejon, Korea. Various plant and leaf characteristics, especially related to photosynthesis, and forage production during the first summer after the establishment were examined. The important conclusions of this study are summarized as follows: 1. The differences of leaf fresh weight among groups and control exhibit genetic differences. The a verage of leaf fresh weight of polycross progeny group was the heaviest and those of winter active synthetic varieties in the succeeding generations of improvement was heavier than variety 'fawn'. Within polycross progeny group the genotypes exhibit genetic differences for leaf dry weight. 2. The leaf area exhibited genetic differences among groups and control. The average of winter active synthetic varieties in a succeeding generation was larger than variety 'Fawn'. Those oi the polycross progeny group was the largest among groups and control. 3. Differences of specific leaf weight(S. L. W.) among and within varieties, genotypes and control were not significant. Further investigation in this respect is necessary through the study of the diurnal change in S. L. W. 4. Differences of leaf width among groups and control exhibited genetic differences. The average leaf width of winter active varieties was larger than those of 'Fawn' variety. And those of polycross progenies of genotypes was the largest. 5. Plant height of 'fawn' variety in the first measurement was higher than those of winter active tall fescue varieties and genotypes. The deviation in plant height among polyeross progenies of seven genotypes gave a great deviation. The regrowth ability of plant height was not different suggesting that this characteristics was about the same among and within groups and control. 6. Plant width, spreading ability, improved through the succeeding generations of the improvement of the winter active synthetic varieties for the first measurement. Differences of plant width at the second measurement among genotypes within polycross progeny group were big enough to show the genetic difference. 7. Tiller number of the winter active synthetic varieties and the average of genotypes in polycross progeny was more than those of the control 'Fawn' in the first measurement. On the second measurement, the differences of tiller number appeared among three synthetic varieties indicating improvement, and there were genetic differences among seven genotypes in polycross progeny test. 8. Forage yield on the first cutting showed a considerble improvement of forage yield in the more advanced generation of synthetic varieties and genetic differences among seven genotypes in the polycross progeny test. The average of polycross progeny group was higher than those of the control or three winter active varieties. It was suggested that we could make a further improvement for the forage yield. 9. The regrowth ability of these winter active varieties and genotypes was about the same capacity at least on the measurement of the regrowth in forage yield and plant height during summer. 10. On the whole, the averages of the polycross progeny group was in the highest value and those of synthetic varieties were higher than the control variety, 'Fawn', for the most characteristics except S. L. W. and the plant height on the first measurement even though the differences were not always significant. And there were genetic differences among seven gentypes in their performance of the polycross progeny. 11. Although it was not always sgnificant, the most advanced winter active variety, '1002', had in the highest value for all plant characteristics and forage yield measurements than the other two varieties, '1001'. 12. The results of the association study among various characteristics were quite agreeable and would be useful in the selection of desirable genotypes for the development of a better variety.

• Progress in Medical Physics
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• v.26 no.3
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• pp.160-167
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• 2015

Radiation exposure from medical diagnostic imaging procedures to patients is one of the most significant interests in diagnostic x-ray system. A miniature x-ray intraoral tube was developed for the first time in the world which can be inserted into the mouth for imaging. Dose evaluation should be carried out in order to utilize such an imaging device for clinical use. In this study, dose evaluation of the new x-ray unit was performed by 1) using a custom made in vivo Pig phantom, 2) determining exposure condition for the clinical use, and 3) measuring patient dose of the new system. On the basis of DRLs (Diagnostic Reference Level) recommended by KDFA (Korea Food & Drug Administration), the ESD (Entrance Skin Dose) and DAP (Dose Area Product) measurements for the new x-ray imaging device were designed and measured. The maximum voltage and current of the x-ray tubes used in this study were 55 kVp, and 300 mA. The active area of the detector was $72{\times}72mm$ with pixel size of $48{\mu}m$. To obtain the operating condition of the new system, pig jaw phantom images showing major tooth-associated tissues, such as clown, pulp cavity were acquired at 1 frame/sec. Changing the beam currents 20 to $80{\mu}A$, x-ray images of 50 frames were obtained for one beam current with optimum x-ray exposure setting. Pig jaw phantom images were acquired from two commercial x-ray imaging units and compared to the new x-ray device: CS 2100, Carestream Dental LLC and EXARO, HIOSSEN, Inc. Their exposure conditions were 60 kV, 7 mA, and 60 kV, 2 mA, respectively. Comparing the new x-ray device and conventional x-ray imaging units, images of the new x-ray device around teeth and their neighboring tissues turn out to be better in spite of its small x-ray field size. ESD of the new x-ray device was measured 1.369 mGy on the beam condition for the best image quality, 0.051 mAs, which is much less than DRLs recommended by IAEA (International Atomic Energy Agency) and KDFA, both. Its dose distribution in the x-ray field size was observed to be uniform with standard deviation of 5~10 %. DAP of the new x-ray device was $82.4mGy*cm^2$ less than DRL established by KDFA even though its x-ray field size was small. This study shows that the new x-ray imaging device offers better in image quality and lower radiation dose compared to the conventional intraoral units. In additions, methods and know-how for studies in x-ray features could be accumulated from this work.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.5
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• pp.638-646
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• 2012

The purpose of this study was to find a relationship between eating behavior, dietary self-efficacy and nutrition knowledge by comparing these items in elementary school students according to food service type. The survey was made through a questionnaire from 759 students in the 6th grade of elementary school in 39 Gangwon Province. The average score of eating behaviors according to food service type was highest for urban type, followed by agri-fishery type, and finally remote island and country type, for the questions asking about the application of nutrition knowledge and the frequency of eating out. The average score of nutrition knowledge according to food service type showed significant differences for the questions about eating snacks before going to sleep and weight increase as well as calorie comparisons between foods. For the correlation of eating behavior, dietary self-efficacy and nutrition knowledge, the agri-fishery type showed positive in all of the three items with significant differences. In the remote island and country type, there was a positive relationship between nutrition knowledge and dietary self-efficacy, and between eating behavior and dietary self-efficacy. However, there was no significant difference of correlation between nutrition knowledge and eating behavior. In order to confirm the predictable variables for eating behavior, a regression analysis was made by injecting variables in every stage with independent variables of dietary self-efficacy and nutrition knowledge, which showed a significant relationship with eating behavior. The results showed that, in the urban type, dietary self-efficacy and nutrition knowledge affected the eating behavior and, in the agriculture type and the remote island and country type, only dietary self-efficacy affected the eating behavior.

• Journal of Intelligence and Information Systems
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• v.24 no.2
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• pp.111-124
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• 2018

This study aims to develop a classification model for predicting the occurrence of hyperlipidemia, one of the chronic diseases. Prior studies applying data mining techniques for predicting disease can be classified into a model design study for predicting cardiovascular disease and a study comparing disease prediction research results. In the case of foreign literatures, studies predicting cardiovascular disease were predominant in predicting disease using data mining techniques. Although domestic studies were not much different from those of foreign countries, studies focusing on hypertension and diabetes were mainly conducted. Since hypertension and diabetes as well as chronic diseases, hyperlipidemia, are also of high importance, this study selected hyperlipidemia as the disease to be analyzed. We also developed a model for predicting hyperlipidemia using SVM and meta learning algorithms, which are already known to have excellent predictive power. In order to achieve the purpose of this study, we used data set from Korea Health Panel 2012. The Korean Health Panel produces basic data on the level of health expenditure, health level and health behavior, and has conducted an annual survey since 2008. In this study, 1,088 patients with hyperlipidemia were randomly selected from the hospitalized, outpatient, emergency, and chronic disease data of the Korean Health Panel in 2012, and 1,088 nonpatients were also randomly extracted. A total of 2,176 people were selected for the study. Three methods were used to select input variables for predicting hyperlipidemia. First, stepwise method was performed using logistic regression. Among the 17 variables, the categorical variables(except for length of smoking) are expressed as dummy variables, which are assumed to be separate variables on the basis of the reference group, and these variables were analyzed. Six variables (age, BMI, education level, marital status, smoking status, gender) excluding income level and smoking period were selected based on significance level 0.1. Second, C4.5 as a decision tree algorithm is used. The significant input variables were age, smoking status, and education level. Finally, C4.5 as a decision tree algorithm is used. In SVM, the input variables selected by genetic algorithms consisted of 6 variables such as age, marital status, education level, economic activity, smoking period, and physical activity status, and the input variables selected by genetic algorithms in artificial neural network consist of 3 variables such as age, marital status, and education level. Based on the selected parameters, we compared SVM, meta learning algorithm and other prediction models for hyperlipidemia patients, and compared the classification performances using TP rate and precision. The main results of the analysis are as follows. First, the accuracy of the SVM was 88.4% and the accuracy of the artificial neural network was 86.7%. Second, the accuracy of classification models using the selected input variables through stepwise method was slightly higher than that of classification models using the whole variables. Third, the precision of artificial neural network was higher than that of SVM when only three variables as input variables were selected by decision trees. As a result of classification models based on the input variables selected through the genetic algorithm, classification accuracy of SVM was 88.5% and that of artificial neural network was 87.9%. Finally, this study indicated that stacking as the meta learning algorithm proposed in this study, has the best performance when it uses the predicted outputs of SVM and MLP as input variables of SVM, which is a meta classifier. The purpose of this study was to predict hyperlipidemia, one of the representative chronic diseases. To do this, we used SVM and meta-learning algorithms, which is known to have high accuracy. As a result, the accuracy of classification of hyperlipidemia in the stacking as a meta learner was higher than other meta-learning algorithms. However, the predictive performance of the meta-learning algorithm proposed in this study is the same as that of SVM with the best performance (88.6%) among the single models. The limitations of this study are as follows. First, various variable selection methods were tried, but most variables used in the study were categorical dummy variables. In the case with a large number of categorical variables, the results may be different if continuous variables are used because the model can be better suited to categorical variables such as decision trees than general models such as neural networks. Despite these limitations, this study has significance in predicting hyperlipidemia with hybrid models such as met learning algorithms which have not been studied previously. It can be said that the result of improving the model accuracy by applying various variable selection techniques is meaningful. In addition, it is expected that our proposed model will be effective for the prevention and management of hyperlipidemia.

• Journal of agricultural medicine and community health
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• v.44 no.4
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• pp.165-184
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• 2019

Objectives: The purpose of this study was to identify and compare the difference and related factors with general characteristic and health behaviors, a experience of diagnosis and treatment of chronic diseases between rural and urban among elderly in Korea. Methods: We used the data of Community Health Survey 2017 which were collected by the Korean Center for Disease Control and Prevention. The study population comprised 67,835 elderly peopled aged 65 years or older who participated in the survey. The chi-square test, univariate and multivariate logistic regression analysis were used to analyze data. Results: We identified many significant difference of health behaviors, an experience of diagnosis and treatment with chronic diseases between rural and urban. Compared to urban elderly, the odds ratios (ORs) (95% confidence interval) of rural elderly were 1.136 (1.092-1.183) for diagnosis of diabetes, 1.278 (1.278-1.386) for diagnosis of dyslipidemia, 0.940 (0.904-0.977) for diagnosis of arthritis, 0.785(0.736-0.837) for treatment of arthritis, 1.159 (1.116-1.203) for diagnosis of cataracts, and 1.285(1.200-1.375) for treatment of cataracts. In the experience of diagnosis and treatment of chronic diseases, various variables were derived as contributing factors for each disease. Especially, there were statistically significant difference in the experience of diabetes diagnosis, arthritis diagnosis, cataract diagnosis and dyslipidemia except for hypertension diagnosis (p <0.01) between urban and rural elderly. There were statistically significant differences in the experience of treatment for arthritis and cataract (p <0.01), but there was no significant difference in the experience of treatment for hypertension, diabetes, dyslipidemia between urban and rural elderly. Conclusion: Therefore, it would be necessary to implement a strategic health management project for diseases that showed significant experience of chronic diseases with diagnosis and treatment, reflecting the related factors of the elderly chronic diseases among the urban and rural areas.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.2
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• pp.129-146
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• 2008

The aim of this study was to compare and analyze wear resistance of acrylic resin tooth in denture opposing to different types of restoration materials. Also, it aimed to compare and analyze the hardness of three various types of resin artificial teeth when using five different types of denture detergents. In this study three types of artificial teeth were used. As ordinary acrylic resin tooth $Trubyte^{(R)}Biotone^{(R)}$ (Dentsply, U.S.A.) was used, and as high hardness resin tooth Endura $Posterio^{(R)}$ (Shofu, Japan) and Physio $Duracross^{(R)}$ (Nissin, Japan) were used. To compare wear resistance, gold alloy, dental porcelain, and composite resin were used as opposing restorations. In addition, with three types of resin tooth stated above, five types of denture detergents, which are $Yuhanrox^{(R)}$ (Yuhanclorox, Korea), $Polident^{(R)}$ (Yuhan Co., Korea), $Cidex^{(R)}OPA$ (Johnson & Johnson Medical Co., Korea), $Hexamedin^{(R)}$ (Bukwang Pharm Co., Korea) and Daihan sterile $water^{(R)}$ (Daihan Pharm Co., Korea) were used to compare and analyze the effects denture detergents have on the surface hardness. The results of this study were as follow : 1. When composite resin and dental porcelain were used as the opposing restorations, $Trubyte^{(R)}$ $Biotone^{(R)}$, Endura $Posterio^{(R)}$, Physio $Duracross^{(R)}$ in ascending order showed decrease of cusp height with significant difference (p<0.05). 2. When gold alloy was used as opposing restoration, there was decrease in the cusp height in order of $Trubyte^{(R)}Biotone^{(R)}$, Endura $Posterio^{(R)}$, Physio $Duracross^{(R)}$ and $Trubyte^{(R)}$ $Biotone^{(R)}$ especially showed significant decrease in high cusp height as compared to two other types of artificial tooth (p<0.05). 3. When composite resin, gold alloy and dental porcelain were used as opposing restorations, $Trubyte^{(R)}$ $Biotone^{(R)}$, Endura $Posterio^{(R)}$, Physio $Duracross^{(R)}$ in order decreased greatly in weight and these three materials showed significant difference (p<0.05). 4. Comparing the experiment values, decrease in strength had significant difference in all resin artificial teeth before and after the denture detergents were used (p<0.05). 5. When resin artificial teeth were subsided in $Yuhanrox^{(R)}$, $Cidex^{(R)}OPA$, and $Hexamedin^{(R)}$, $Trubyte^{(R)}$ $Biotone^{(R)}$, Endura $Posterio^{(R)}$, Physio $Duracross^{(R)}$ in order showed decrease in hardness, and $Trubyte^{(R)}$ $Biotone^{(R)}$ especially showed significant high decrease hardness as to other two types of artificial teeth (p<0.05). Therefore, Physio $Duracross^{(R)}$ seems to have superior wear resistance, and together with Endura $Posterio^{(R)}$, it presents excellent hardness as compared to $Trubyte^{(R)}$ $Biotone^{(R)}$. However, since this study is fragmentary, it should be given careful consideration and more study need to be done before making a definitive conclusion.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.4
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• pp.343-358
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• 2011

As implant treatment has become popular, lots of different shapes and materials of the implant upper component have been supplied. And there are also diverse reports about failures including loosening of the abutment screw which is one of the most common reason. Purpose : The purpose of this study is to find out how different screw tightening orders and methods influence on screw loosening according to the different connection systems. The upper component was fabricated by casting method. After fabricating master models that are precisely attached to the upper component, 5 experimental models each for the external connection system and internal connection system were fabricated using splinting impression technique. First, to find out the influence of the screw tightening order, screws were tightened in 3 orders; 1-2-3-4, 2-3-1-4, 2-4-3-1. After tightening, removal torque values (RTV) of each group was measured. And also to find out the influence of screw tightening method, a model with 2-3-1-4 screw tightening order was tightened with 30 Ncm at one time(1-step method) and the RTV was compared with the same order group (2-3-1-4) in the 2 step method. In the external connection system, RTV appeared significantly lower in group 2-3-1-4 than group 2-4-3-1 (p<0.05). And also in the internal connection system, the RTV of group 2-3-1-4 appeared significantly lower than that of group 2-4-3-1 and 1-2-3-4 (p<0.05). When comparing the tightening number of the screw without considering the screw tightening order, the first tightened screw appeared significantly higher RTV than the second one in the external connection system (p<0.05), however there was no significant difference from the first tightened screw to the last tightened screw in the internal connection system. And there was no statistically significant difference between the two screw tightening methods in both internal and external connection system. In the comparison of external and internal connection system, each RTV appeared 16.27 Ncm and 14.25 Ncm and appeared as a statistically significant difference (p<0.05). There was a significant difference in RTV measured according to the screw tightening order. The lowest RTV appeared in the groups started tightening from the middle. There was also a significant difference in RTV between the two connection system groups. A further study is needed to find out the influence factors in RTV and also a study is required related to the load condition.

• Tuberculosis and Respiratory Diseases
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• v.40 no.1
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• pp.6-15
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• 1993

Background: Positive end, expiratory pressure (PEEP) has become one of the standard therapies for adult respiratory distress syndrome (ARDS). Total static compliance has been proposed as a guide to determine the size of PEEP ('best PEEP') which is of unproven clinical benefit and remains controversial. Besides increasing functional residual capacity and thus improving oxygenation, PEEP stimulate prostacyclin secretion and was proposed for the treatment of acute pulmonary embolism. But little is known about the effect of PEEP on hemodynamic and gas exchange disturbances in acute pulmonary embolism. Methods: To study the validity of total static compliance as a predictor of 'best PEEP' in ARDS and acute pulmonary embolism, experimental ARDS was induced in mongrel dog with oleic acid and acute pulmonary embolism with autologous blood clot. Then hemodynamic and gas exchange parameters were measured with serial increment of PEEP. Results:In ARDS group, total static compliance and oxygen transport were maximal at 5 cm$H_2O$, and decreased thereafter (p<0.05). With increment of PEEP, arterial oxygen tension ($PaO_2$) and arterial carbon dioxide tension ($PaCO_2$) increased and cardiac output and physiological shunt decreased. In pulmonary embolism group, total static compliance, oxygen transport, physiological shunt and cardiac output decreased and $PaO_2$ and $PaCO_2$ increased with increment of PEEP (p<0.05). Comparing the change induced by increment of PEEP by 1 cm$H_2O$ in ARDS group with that in pulmonary embolism group, there was no significant difference between two groups except cardiac output which decreased more in pulmonary embolism group (p<0.05). In ARDS group, oxygen transport and total static compliance increased after PEEP application, and total static compliance was maximal at the PEEP level where oxygen transport was maximal. However in pulmonary embolism group, oxygen transport and total static compliance decreased after application of PEEP. There was significant correlation between change of total static compliance and change of oxygen transport in both groups. Conclusion: In both ARDS and acute pulmonary embolism, it can be concluded that total static compliance is useful as a predictor of 'best PEEP'.

• Clinical and Experimental Pediatrics
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• v.49 no.3
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• pp.305-311
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• 2006

Purpose : GnRH analogues(GnRHa) are used to treat central precocious puberty(CPP). However, in some patients, the GV decrease is so remarkable that it impairs predicted adult height(PAH); and there fore, the addition of growth hormone(GH) is suggested. We analysed the growth changes during two years and final adult height(FAH) in girls with idiopathic CPP treated with combined therapy, compared with those of girls treated with GnRHa alone. Methods : For the analysis, we classified the patients, who was treated for longer than two years, into three groups depending on the initial PAH and combination of GH; PAH_L, treated with GnRHa and PAH less than midparental height(MPH) - 5 cm. PAH_H, treated with GnRHa and PAH greater than MPH - 5 cm. GnRHa＋GH, combined GH treatment, regardless of PAH before treatment. We analysed the GV and PAH change during the first two years and FAH. Results : In PAH_L, the PAH(SDS) at first year of therapy was significantly increased to $153.5{\pm}6.5cm(-1.4{\pm}1.3)$ from $149.7{\pm}6.4cm(-2.1{\pm}1.3)$ before treatment(P=0.004). In PAH_H, there was no significant increase in PAH during the two years of treatment. During the first year of combination of GH and GnRHa, GV and PAH increased significantly. We observed significant increases in FAH, comparing to the initial PAH in the PAH_L and GnRHa＋GH groups. The height gains(FAH - initial PAH) were significantly higher in the PAH_L and GnRHa＋GH groups than that in the PAH_H group. Conclusion : This study suggests the FAH and height gains are improved in patients, whose predicted adult height before treatment was shorter than those with higher predicted adult height, with the treatment of GnRHa alone or in combination with GH. GH could not improve the final adult height, but compensated the growth in patients whose growth velocity was decelerated by GnRHa alone.