• Journal of People, Plants, and Environment
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• v.24 no.5
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• pp.519-527
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• 2021

Background and objective: This study was conducted to establish a Plant Hardiness Zone (PHZ) map, investigate the effect of global warming on changes in PHZ, and elucidate the difference in the distribution of evergreen trees between the central and southern region within hardiness Zone 7b in Korea. Methods: Mean annual extreme minimum temperature (EMT) and related temperature fluctuation data for 40 years (1981 to 2020) in each of the meteorological observation points were extracted from the Open MET Data Portal of the Korea Meteorological Administration. Using EMT data from 60 meteorological observation points, PHZs were classified according to temperature range in the USDA Plant Hardiness Zone Map. Changes in PHZs for each decade related to the effects of global warming were analyzed. Temperature fluctuation before and after the day of EMT were analyzed for 4 areas of Seoul, Suwon, Suncheon, and Jinju falling under Zone 7b. For statistical analysis, descriptive statistics and ANOVA were performed using the IBM SPSS 22 Statistics software package. Results: Plant hardiness zones in Korea ranged from 6a to 9b. Over four decades, changes to warmer PHZ occurred in 10 areas, especially in colder ones. Based on the analysis of daily temperature fluctuation, the duration of sub-zero temperatures was at least 2 days in Seoul and Suwon, while daily maximum temperatures were above zero in Suncheon and Jinju before and after EMT day. Conclusion: It was found that the duration of sub-zero temperatures in a given area is an important factor affecting the distribution of evergreen trees in PHZ 7b.

• Structural Engineering and Mechanics
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• v.19 no.3
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• pp.347-359
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• 2005

This paper attempts to develop the analytical model of estimating the fatigue damage using a linear elastic fracture mechanics method. The stress history on a welding member, when a truck passed over a bridge, was defined as a block loading and the crack closure theory was used. These theories explain the influence of a load on a structure. This study undertook an analysis of the stress range frequency considering both dead load stress and crack opening stress. A probability method applied to stress range frequency distribution and the probability distribution parameters of it was obtained by Maximum likelihood Method and Determinant. Monte Carlo Simulation which generates a probability variants (stress range) output failure block loadings. The probability distribution of failure block loadings was acquired by Maximum likelihood Method and Determinant. This can calculate the fatigue reliability preventing the fatigue failure of a welding member. The failure block loading divided by the average daily truck traffic is a predictive remaining life by a day. Fatigue reliability analysis was carried out for the welding member of the bottom flange of a cross beam and the vertical stiffener of a steel box bridge by the proposed model. Results showed that the primary factor effecting failure time was crack opening stress. It was important to decide the crack opening stress for using the proposed model. Also according to the 50% reliability and 90%, 99.9% failure times were indicated.

• Journal of the East Asian Society of Dietary Life
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• v.4 no.2
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• pp.17-26
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• 1994

This study was an attempt to investigate various factions, such as the calorie, nutrient intake, physical activity, blood lipids, obesity prevalence and body fat distribution on NIDDM male diabetics. General characteristics, physical activity and exercise levels of subjects were invesigated by interviewing, daily calorie and nutrient intake were measured by convenient method. The following anthropometric measurements were made on all participats : weight, height. Also waist and hip circumference were measured on 174 male diabetics to get waist-to-hip circumference ratio as index of the body fat distribution. For measurement of plasma lipids, 12-hour fasting blood samples were drawn The results of this study were summarized as follows : 1. At the onset of diabetes, the major self-diagnosed symptoms were polydipsia, fatigue, and body weight redution 2. The average of daily energy intake of male diabetics was 2106 Kcal which is 96% of the RDA Percentage of energy is that carbohydrate:protein : pat=70:14:16. 3. Among the NIDDM male subjects, 59% was exercise regularly. 4. Obese subjects above in the ideal body weight of 120% are presently 17%, but 39% of subjects were reported to be obese in the past. The mean BMI of the male NIDDM diabetics is 23.3${\pm}$2.6 and the past mean BMI was 25.2${\pm}$2.7 The mean WHR was 0.93${\pm}$0.10. 5. When diabetics were divided into obese and nonobese group according to RBW, energy intake, blood pressure, blood glucose and total cholesterol were not significantly different between the two groups, but LDL and VLDL-cholesterol were significantly higher in the obese group. 6. RBW did not correlate with cholesterol and triglyceride, but WHR correlated significantly with cholesterol and triglyceride. In conclusion, these results from a present study support previous findings indicating that not only the degree of obesity but also the localization of fat is a risk factor for diabetes.

• Journal of Korean Physical Therapy Science
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• v.16 no.3
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• pp.55-66
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• 2009

Background: The purpose of this research was to investigate the factors affecting the low back pain of workers in hospital. 214 subjects waking at two general hospitals in Yosu city participated in this survey. Subjects consisted of doctors, nurses, medical engineers, officers and general laborers. The survey data were collected by a written questionnaire which made out by themselves for 25 days, from fourth August to 29th August, 2008. Methods: The questionnaire consisted of four categories, general, occupational, working habitual and the daily living characteristics. The collected data were analyzed by Chi-square test based on the present or absent of low back pain. Results: 1. In the general characteristics, low back pain had no significant relationship to all factors, sex, ago, body mass index, weight and height. 2. In the occupational characteristics, the phase of distribution of low back pain had statistical significant differences in the working hours a week, satisfaction of pay, satisfaction of occupation(p<0.05). However low back pain did not significantly related to the kind of occupation, period of work and degree of stress. 3. In the habitual characteristics, low back pain was significantly influenced by working posture, frequency of using lumbar and heavy material lifting, monotonous repetition of working operation and noise(p<0.05). No significant difference was shown in the factor of convenience of chair. 4. In the daily living characteristics, low back pain shown the significant differences in walking time a day, status of health and smoking pattern(p<0.05). there were, however, no significant differences in the aspect of the kind of house and bed, sleeping attitude, driving, riding time on the vehicle, exercising, frequency of cultural life and drinking alcohol. Conclusion: when I see above resultants totally, it appears a higher incidence caused by working environment rather than living habit and then consequently compared to hospital workers, they also have high incidence like others. In order to reduce incidence of low back pain and enjoy the our life we need to educate ourselves preventing program for low back pain and try to effort for preventing of low back pain on each department and individual.

• Proceedings of the KAIS Fall Conference
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• 2002.11a
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• pp.141-144
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• 2002

Recently, the operation of power distribution systems has become more difficult because the peak demand load is increasing continuously and the daily load factor is getting worse and worse. Also, the consideration of deregulation and global environment in electric power industry is required. In order to overcome these problems, a study on the planning and operation in distribution systems of dispersed generating sources such as fuel cell systems, photovoltaic systems and wind power systems has been performed energetically. This study presents a method for determining an optimal operation strategy of dispersed co-generating sources, especially fuel cell systems, in the case of both only electric power supply and thermal supply as well as electric power supply. In other words, the optimal operation of these sources can be determined easily by the principle of equal incremental fuel cost and the thermal merits is evaluated quantitatively through Kuhn-Tucker's optimal conditions. In order to select the optimal locations of those sources, an priority method using the comparison of total cost at the peak load time interval is also presented. The validity of the proposed algorithms is demonstrated using a model system.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.325-330
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• 2006

Modern people spend more and more time in an automobile in their daily life. In this life, drivers and passengers should create HVAC environment in the automobile interior which is not only for convenient transportation but also give comfortable feeling with dwelling culture. Also, the latest cars give much importance for the role of HVAC system that controls the environment of the area for passengers more than just basic capability. There are solar radiant heat, surface temperature, refrigeration system(temperature, humidity, air current, velocity), and dust for the factor which have an effect on the HVAC environment in the automobile interior, also these are being carried for the HVAC environment delivered an individual character. In this study, we drew the automobile interior as three dimension and arranged a method of numerical analysis on HVAC environment in the automobile interior displaying air current distribution and temperature distribution through simulation of the automobile interior on the ventilation volume and outlet area. The aim of this study is to develop the estimated method for HVAC environment. in the automobile interior.

• Korean Journal of Child Studies
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• v.32 no.3
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• pp.1-17
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• 2011

This study was aimed at developing a scale to evaluate Korean home environments for infants and toddlers for the purpose of being used by teachers caring for infants and toddlers. The subjects of this study were 250 mothers of 0- to 2-year-olds. Mean, SD, $x^2$, Cramer's V, factor analysis, Pearson correlations, Cronbach's ${\alpha}$ were calculated in order to analyze the outcomes of this study. As a result, 38 items of the scale were found to be satisfactory in terms of item distribution and item discrimination. Four factors with 21 items were extracted from the factor analysis : 'developmental stimulus', 'responsivity', 'encouragement of verbal interaction', and 'arrangement of daily routines'. Our analysis of the correlation of this scale with SES, HOME, and children's developmental outcomes showed acceptable concurrent validity. Internal consistency of this scale was high. These results identify this scale as a valid and reliable measure of the Korean home environment for infants and toddlers.

• The Korean Journal of Community Living Science
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• v.21 no.3
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• pp.299-310
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• 2010

The purpose of this study was to develop a scale to assess a Korean home environment for middle childhood children. The subjects were 283 mothers of 6- to 8-year-old children in Korea. The method for data analysis included Mean, SD, $x^2$, Cramer's V, factor analysis, Pearson correlations, and Cronbach's $\alpha$. As a result, 45 items of the scale were found to be satisfactory in terms of item distribution and item discrimination(Cramer's discriminant coefficients ranged from .256-.615). Four factors with 21 items were extracted from the factor analysis. Subscales were 'academic stimulation(9)', 'acceptance(4)', 'child-centered environment(4)', 'basic care for daily routine(4)'. Analysis of the relation of this scale to SES, MC-HOME, and children's developmental functioning(cognitive, language, and social) showed acceptable concurrent validity. Internal consistency of this scale was high, including internal reliability of subscales. These results confirm this scale as a valid and reliable measure of the Korean home environment for middle childhood children.

• Clinical and Experimental Pediatrics
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• v.51 no.4
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• pp.355-361
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• 2008

Pollen is very important causing factor for allergy such as allergic rhinitis, allergic conjunctivitis, and asthma, and pollen allergy has a remarkable clinical impact all over Korea. The main pollination period covers about half the year, from spring to autumn, and the distribution of airborne pollen taxa of allergological interest is related to pollen season dynamics. Korean academy of pediatric allergy and respiratory diseases (KAPARD) has evaluated the pollen characteristics and nationwide pollen count for over 10 years since 1997. Airborne particles carrying allergens were collected daily from nationwide 8 stations (Seoul, Guri, Cheongju, Daegu, Kwangju, Busan, Kangneung, and Jeju) by using 7 days-Burkard sampler (Burkard Manufacturing Co Ltd, Hertfordshire, UK) in South Korea (July 1, 1997-June 30, 2007). They were counted and recorded along with the meteorological factors daily. Tree pollen is a major airborne allergen in spring, grass is most common in summer, and weed pollen is major pollen in autumn in Korea. There has two peak seasons for pollen allergy, as summer and autumn. There is some evidence suggesting that the prevalence of allergic diseases in Korea has been on the increase in the past decade. However, recent findings of the phase I and II studies of the international Study of Asthma and Allergies in Childhood (ISAAC) study showed the absence of increases or little changes in prevalence of asthma symptoms and diagnosis rates in Korea, whereas the prevalence of allergic rhinitis and atopic dermatitis were increased. We reported the evidence that sensitization rate to weed pollen has been increased yearly since 1997 in childhood. Climate change and air pollution must be the major causing factors for the increase of pollen counts and sensitization rate to pollen. Climate change makes the plants earlier pollination and persisting pollination longer. In conclusion, data on pollen count and structure in the last few years, the pathogenetic role of pollen and the interaction between pollen and air pollutants with climate change gave new insights into the mechanism of respiratory allergic diseases in Korea.

• Journal of the Korean Society of Industry Convergence
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• v.2 no.1
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• pp.35-43
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• 1999

The purpose of this study is to derive the optimal methodology estimating the changes of fluvial hydraulic characteristics due to semi-covering work of urban stream. First, after collecting the data of the daily maximum rainfall of Chungju gaging station, the frequency analysis was carried out with frequency factor method, which includes normal, two-parameter and three-parameter lognormal, Gumbel-Chow, pearson type III, log-pearson type III distribution, and the goodness of fit test was executed by $x^2$-test and Kormogorov-Smimov test. Using the SCS method, the effective rainfall was estimated and the peak flow was calculated by the area-routing method. The HEC-2 model was applied to calculate water surface profiles for steady, gradually varied flow at Kyohyun river system in Chungju city. The model was applied to floodplain and riverbed management to evaluate flood way encroachments and to delineate flood hazard by riverside roadway construction. The model also was used to evaluate effects on water surface profiles of river improvement and levees as well as the presence of bridges or other hydraulic structures in the floodplain.