• Journal of Korean Dental Science
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• v.16 no.1
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• pp.47-62
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• 2023

Purpose: We aimed to investigate the objective cutoff values of unstimulated flow rates (UFR) and stimulated salivary flow rates (SFR) in patients with xerostomia and to present an optimal machine learning model with a classification and regression tree (CART) for all ages. Materials and Methods: A total of 829 patients with oral diseases were enrolled (591 females; mean age, 59.29±16.40 years; 8~95 years old), 199 patients with xerostomia and 630 patients without xerostomia. Salivary and clinical characteristics were collected and analyzed. Result: Patients with xerostomia had significantly lower levels of UFR (0.29±0.22 vs. 0.41±0.24 ml/min) and SFR (1.12±0.55 vs. 1.39±0.94 ml/min) (P<0.001), respectively, compared to those with non-xerostomia. The presence of xerostomia had a significantly negative correlation with UFR (r=-0.603, P=0.002) and SFR (r=-0.301, P=0.017). In the diagnosis of xerostomia based on the CART algorithm, the presence of stomatitis, candidiasis, halitosis, psychiatric disorder, and hyperlipidemia were significant predictors for xerostomia, and the cutoff ranges for xerostomia for UFR and SFR were 0.03~0.18 ml/min and 0.85~1.6 ml/min, respectively. Conclusion: Xerostomia was correlated with decreases in UFR and SFR, and their cutoff values varied depending on the patient's underlying oral and systemic conditions.

• Journal of Forest and Environmental Science
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• v.26 no.3
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• pp.161-170
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• 2010

A study was conducted for indentifying the floral biodiversity of woody species by calculating four diversity indices using data collected from 4 stands of different age groups and disturbance regimes in two areas of Madhupur tract. Results showed that highest species diversity in the old growth secondary coppice forest (>60 years) under moderate anthropogenic disturbances of Madhupur National Park area (delete (D=0.74, H'=3.36) followed by old growth secondary forest stands (>40 years) under moderate disturbances at Bhawal National Park area (D=0.65, H'=2.81). Plant species diversity of the young enrichment plantations (<20 years and <15 years) under high anthropogenic disturbances in both the areas are much low (D=0.54 and H'=2.16 and D=0.52 and H'=1.92 respectively), which indicate high anthropogenic disturbances coupled with introduction of invasive exotics that are rival for endemic species are detrimental for conservation of biological diversity of tropical moist deciduous forests of Madhupur tract in Bangladesh.

• Journal of Korea Trade
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• v.27 no.1
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• pp.119-138
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• 2023

Purpose - This research is to empirically explore the differences in apparel consumption among male and female teenagers and college students in Korea and China. By conducting a survey to understand customers' needs and behaviors, fashion businesses will be able to improve their customer satisfaction and avoid redundancy, inventory, and the waste of resources, effort and money. Design/methodology - The research design considers the consumption patterns of male and female high school and college students in Korea and China. To analyze the data, the study employs decision trees, a type of machine learning algorithm. A decision tree model was developed to examine the relationship between the explanatory and response variables, which can be either quantitative or qualitative in nature. Findings - The main findings of this study indicate that there are differences in shopping behavior among different customer segments. The results show that men have a simpler shopping behavior compared to women. Additionally, cultural factors and the difference in fashion needs between students and non-students have a significant impact on the shopping choices of Chinese and Korean individuals. Originality/value - Existing studies often assume that the shopping behavior of high school and university students is similar and that there are no significant differences in clothing purchases between men and women across countries. The results provide valuable insights into the unique shopping behavior of different customer segments, and can inform fashion businesses in their efforts to meet the needs of their customers.

• Journal of the Korean Society of Radiology
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• v.83 no.5
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• pp.979-990
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• 2022

Biliary atresia is a progressive, idiopathic, obliterative disease of the extrahepatic biliary tree that presents with biliary obstruction in the neonatal period. It is the most common indication for liver transplantation in children. If untreated, progressive liver cirrhosis leads to death by two years of age. Nowadays, more than 90% of biliary atresia patients survive into adulthood with the development of Kasai portoenterostomy and liver transplantation technology. Early diagnosis is critical since the success rate of the Kasai portoenterostomy decreases with time. This study comprehensively reviews the recent advances in the etiology, classification, prevalence, clinical manifestations, treatment, and prognosis of biliary atresia.

• Journal of Korean Society of Forest Science
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• v.60 no.1
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• pp.17-23
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• 1983

Total 83model forest owners in Korea were investigated to find out the relationship between their attitudes toward tree felling (or propensity to felling) and selected six independent variables, i.e, owner's age(X1), educational level(X2), forest land area (X3), socioeconomic status (X4), communication (X5) and sociopsychological factor(X6). The dependent variable was measured by Liken attitude scale, and analyzed by multiple regression. Major findings of the study are summarized as follows: 1) The degree of the propensity of felling is relatively high. The communication and sociopsychological variables are negatively, but education level is positively related to the dependent variable. 2) The multiple correlation coefficient between felling-attitude score and six independent variables is 0.5322. Of the variance of this sttitude score, about 13 percent can be explained by communication variable, 6 percent by sociopsychological variable and other 6 percent by age variable. 3) The model owners' attitudes toward felling are positively correlated with there sources of communication variable, i.e. personal contact, social participation and mass media contact. The multiple correlation coefficient between felling-attitude score and three sources of communication variable is 0.4049. This means that 16 percent of the variance of the attitude score can be explained by three sources of communication, that is, 9 percent by personal contact, 5 percent by social participation and 3 percent by mass media. 4) The fatalistic, untrustful and non-ambitious personalities were positively, but conservative personality negatively related to the propensity to tree felling. The multiple correlation coefficient between seven different personalities and the dependent variable is 0.5461. Of the variance of the dependent variable, 11 percent can be explained by untrustful personality, and other 11 percent by nonambitious personality.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.301-311
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• 2013

This study aims to analyze characteristics, health behaviors and health management level related to private health examination recipients in one general hospital. To achieve this, we analyzed 150,501 cases of private health examination data for 11 years from 2001 to 2011 for 20,696 participants in 2011 in a Dae-Jeon general hospital health examination center. The cluster analysis for classify private health examination group is used z-score standardization of K-means clustering method. The logistic regression analysis, decision tree and neural network analysis are used to periodic/non-periodic private health examination classification model. 1,000 people were selected as a customer management business group that has high probability to be non-periodic private health examination patients in new private health examination. According to results of this study, private health examination group was categorized by new, periodic and non-periodic group. New participants in private health examination were more 30~39 years old person than other age groups and more patients suspected of having renal disease. Periodic participants in private health examination were more male participants and more patients suspected of having hyperlipidemia. Non-periodic participants in private health examination were more smoking and sitting person and more patients suspected of having anemia and diabetes mellitus. As a result of decision tree, variables related to non-periodic participants in private health examination were sex, age, residence, exercise, anemia, hyperlipidemia, diabetes mellitus, obesity and liver disease. In particular, 71.4% of non-periodic participants were female, non-anemic, non-exercise, and suspicious obesity person. To operation of customized customer management business for private health examination will contribute to efficiency in health examination center.

• The Journal of Korean Society for Radiation Therapy
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• v.13 no.1
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• pp.75-90
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• 2001

Although it is presumed that cancer patients take various alternative therapies, the present status is not well recognized. The purpose of this study is to survey alternative therapies used by cancer patients receiving radiation therapy and then, find associated factors of taking alternative therapies. The study subjects were composed of those who receiving radiation therapy in the department of radiation oncology in 5 hospitals located at Extended Busan city and who were on follow-up after medical cure. They were 394 male and female patients over 20 years old. The mean age of the subjects was 53.2 years old and the age ranged from 23 to 83 years old. 188 patients($47.7\%$) used alternative therapies. Total 68 different kinds of alterative therapies were used, average 7.3 kinds per patient were experienced, and average total cost expenditure was 2,830,000 won. Among the alternative therapies, black bean($38.8\%$) was the most commonly used and brown rice($38.3\%$), ganoderm lucidum($37.8\%$), elm tree($33.5\%$), and phellinus linteus($30.8\%$) were followed in order of frequency. However in considering the time, cost and effort spent, phellinus linteus was the first. In terms of cost, phellinus linteus was the highest with average expenditure of 2,740,000 won. Among the motivation of using alternative therapies, expecting auxiliary help for the hospital therapy was the highest ($31.4\%$). About half of users($56.9\%$) of alternative therapies were recommended by their relatives to use alternative therapies. In comparing the characteristics of experienced and unexperienced groups, alternative therapy was experienced significantly more in patients of younger age(p=0.001), in patient of higher educational level(p=0.001), and in patients of higher income(p=0.030) The proportion of using alternative therapies was significantly higher in the group treated with chemotherapy(p=0.005), and in the patients who did not satisfy with radiation therapy(p=0.001). The frequency of drinking was significantly higher tendency in the inexperienced group(p=0.046), There was no significant difference in marital status, job, religion, other disease, surgical operation of the cancer and smoking staus between the two groups. Among the unexperienced group, $34.0\%$ of the patients did not take the alternative therapies because they did not have know]edge for the alternatives, and $22.3\%$ worried about negative effects on hospital-based therapy $58.7\%$ of them were willing to take the alternative therapies if the effects and safety were proven by the government or research institutes. $21.9\%$ of the patients wanted to take the alternatives if they were affordable. $72.3\%$ of the patients was willing to take them if their families recommend, but $27.2\%$ responded they would not take them in any situation. Conclusively, various kinds of alternative therapies which were not proved medically were exposed to patients, In these circumstances, it is required to investigate, study and evaluate the medical effects and safety of the alternative therapies.

• Journal of Korean Society of Forest Science
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• v.68 no.1
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• pp.52-59
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• 1985

This study was carried out to compare the diameter increment of Pinus densiflora for.erecta, Pinus koraiensis, Larix leptolepis, Abies holophylla and Abies koreana growing in middle area of Korea. The results obtained were summarized as follows; 1) The difference in annual diameter increment among five species according to D.B.H classes showed to be the strongest in Pinus koraiensis the second rank Larix leptolepis, the third rank Pinus densiflora erecta, the fourth rank Abies holophylla and the weakest in Abies koreana. 2) It was inferred that when the D.B.H of Pinus densiflora for.erecta comes to 95cm, Pinus koraiensis 80cm, Larix leptolepis 80cm, Abies holophylla 140cm and Abies koreana 85cm respectively, their diameter do not increase. 3) Total D.B.H increment among five species according to tree age classes were ranked as follows; Larix leptolepis, Pinus koraiensis, Pinus derasiflora for.erecta, Abies holophylla and Abies koreana. 4) It was inferred that when the age of Pinus densiflora for.erecta comes to 200yrs, Pinus koraiensis 120yrs, Larix leptolepis 120yrs, Abies holophylla 260yrs and Abies koreana 300yrs respectively, their diameter do not increase. 5) Abies koreana showed the lowest diameter increment in comparison with other four species, while diameter increment in Abies holophylla and Abies koreana decreased in later age than other species.

• Pediatric Infection and Vaccine
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• v.22 no.2
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• pp.81-90
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• 2015

Purpose: Group A rotavirus (RV) is most common etiologic agent of acute gastroenteritis (AGE) in children worldwide. Recently, vaccination has been introduced in several countries to reduce the disease burden caused by RV infections, but continuous surveillance of RV strains is necessary to detect the emergence of potential variants induced by vaccine-immune pressure. This study aimed to investigate the changing pattern of RV genotypes in children with AGE, following the introduction of vaccination in Korea. Methods: Genotyping of RVs by RT-PCR on the basis of VP7 and VP4 gene segment sequence was carried out on 201 rotavirus-positive stool samples, from children hospitalized with AGE between August 2009 and June 2013. We have directly sequenced PCR products and analyzed the phylogenetic tree. Results: The most prevalent G genotype was G9 (33.3%), followed by G1 (22.4%), G3 (15.9%), G2 (6.0%), G4 (3.0%), G10 (1.5%), and mixed G-type (15.4%), with some nontypeable cases (2.5%). The detected P genotypes were P[4] (45.3%), P[8] (43.8%), mixed P-type (10.4 %), and P[2] (0.5%). The G9P[4] genotype was predominantly observed in hospitalized cases in Seoul in 2010/2011, however G1P[8] has been re-emerged as the predominant genotype in the following season (P =0.004). Conclusions: It seems that the periodic fluctuation in predominance of the G1, G3, and G9 strains occurred in Korea during 2009-2013, following the introduction of RV vaccination.

• Journal of Korean Society of Forest Science
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• v.106 no.2
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• pp.267-273
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• 2017

This study was conducted to construct a empirical yield table for Pinus densiflora in real forest. Since existing normal yield tables have been derived by studying and analyzing communities in ideal environment for tree growth, those tables provide more over-estimated values than ones from real forest. Because of this, there are some difficulties to apply the tables to empirical forest except for normal forest. In this study, therefore, we estimated stand growth for real forest on P. densiflora as the representative species of conifers. We used 1,957 sample plot data of P. densiflora in central Korea from National Forest Inventory (NFI) system, and analyzed through estimation, recovery and prediction in order by using Weibull function as a diameter distribution model. Weilbull and Schumacher models were applied for estimating mean DBH and mean basel area and it was found that the site index for P. densiflora in central Korea ranges from 8 to 14 at reference age 30. According to site 12 in the stand yield table, the Mean Annual Increment (MAI) of P. densiflora was $4.42m^3/ha$ at 30 years of age. Compared to existing volume table constructed before, it is showed that MAI of this study were lower. According to the paired t-test that is conducted with the gap of volume values between normal forest and real forest by site index and age, the P-value was less than 0.001 which is recognized to have a statistically significant difference. Based on the results in this study, it is considered to be helpful for practical management and management policy on P. densiflora in central Korea.