• The Korean Journal of Ecology
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• v.19 no.3
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• pp.223-230
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• 1996

Five measurements of species diversity (richness index, diversity index, evenness index, dominance index and species sequences-importance curve) and their relationships with sltitude, tree age and community type were studied in $T\v{o}gyusan$ National Park, Korea. Altitude and tree age were the major variables explaining the differences of species diversity in the whole forest. Species richness index, diversity index and evenness index of Quercus mongolica and Pinus densiflora communities were lower than those of Carpinus laxiflora, Q. serrata, Fraxinus mandshurica, Q. mongolica - P. densiflora communities than that in the other communities. The species sequence-importance curve of the forest communities in $T\v{o}gyusan$ coincided with the ideal curve calculated by the lognormal-distribution theory.

• Annals of Clinical Neurophysiology
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• v.3 no.1
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• pp.31-36
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• 2001

Background & Objectives : Fractal Dimension(FD) could be an index of correlation between variable parameters in non-linear chaotic signals. We tried to demonstrate that EEG wave is compatible with chaotic waves by measuring the Lyapunov exponent index and compared the difference of FD between variable age groups(teens, 30's, 50's) Methods : We estimated the Lyapunov exponent index and the FD from digital EEG data among five persons in each normal age groups by using the software which is programmed in our laboratory. Statistical analysis was done with SPSS win 8.0. The statistical differences of Lyapunov exponent index and FD between each electrodes and each age groups were done with ANOVA and paired sample t-test. Result : The Lyapunov exponent indexes were larger than 1 in each electrode and age group. There is no statistical difference in FD between each electrodes and each age groups. Except in 30th age group. In this group the FD of right hemisphere is larger than that of left hemisphere. Conclusion : The result of Lyapunov exponent index means EEG wave is a non-linear chaotic signal. And the results of FD suggest that chaotic parameters of right hemisphere is larger than those of left hemisphere at rest at least in younger people. We think that chaotic parameters can be a useful tool in investigating the variable diseases or brain states.

• Journal of Preventive Medicine and Public Health
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• v.12 no.1
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• pp.24-30
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• 1979

This study was conducted to find out the most suitable weight-height index out of the $weight/height^{p}-type$ indices that could be used for the evaluation of nutritional status in an epidemiological survey and for the screening of the obesity. The subjects were chosen randomly, 2,182 males and 719 females from college students and office workers in Seoul districts. The 'best' power-type weight-height index for Korean men and women of all ages from 16 to 59 was found to be $weight/height^{1.54}$ for males and $weight/height^{1.42}$ for females. $Weight/height^2$ (Kaup index), however, was the best suited weight-height index for each age group of both sexes except that relative weight (weight/height) was considered to be desirable to apply for males of teen-aged and of over fifties and for females of over forties of age. Normal ranges of Kaup index values for males and females of each age group were presented in tables 5 and 6. These findings suggest that Koreans are generally leaner than other ethnic groups of the same sex and age.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.19-28
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• 2010

The purpose of this study was to increase the current understanding of the acoustic characteristics of voices with advancing age. The relationship between age-related changes in body physiology and certain acoustic characteristics of voice was studied in a sample of 80 men representing four chronological age groupings (20-29, 50-59, 60-69, 70-79) who were all of good physical condition. Each subject was asked to phonate the vowel /a/, /i/, and /u/ for as long as possible at comfortable frequency and intensity level and read the sentence. A promising voice analysis program (Multi-Dimensional Voice $Program^{TM}$) was used to measure the fundamental frequency ($f_0$), jitter, shimmer, $f_0$ variation, peak-amplitude variation, smoothed pitch perturbation quotient, smoothed amplitude perturbation quotient, soft phonation index, $f_0$-tremor intensity index, amplitude tremor intensity index, and noise-to-harmonics ratio from the samples.

• Human Ecology Research
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• v.56 no.3
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• pp.217-232
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• 2018

This study analyzes the determining factors of the digital divide index in married female immigrants based on panel data from the National Information Society Agency (2016). There were 287 participants, all of whom owned a smartphone. The study divided the consumer groups into three age groups: 20-29, 30-39, and 40-49 years. SPSS 19.0 was used to statistically analyze the results. The findings of the analysis were described using frequency, descriptive, cross-tab, ANOVA, correlation, and multiple regression analysis. The findings of this research are as follows. First, nationality, acquisition of Korean nationality, and duration of living in Korea were significantly different among the three groups. Second, digital competency and online service usage were also significantly different among the three groups. Third, PC usage ability, mobile usage ability, and diversity of online usage significantly influenced the digital divide index in all age groups. Fourth, residential duration in Korea significantly decreased the digital divide index for groups in their 30s and 40s. Fifth, Loneliness significantly increased the digital divide index for groups in their 20s. Sixth, depression significantly increased the digital divide index for groups in their 30s. The study will help to further understand age-related differences and the digital divide of married female immigrants.

• Journal of Korean Biological Nursing Science
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• v.24 no.1
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• pp.26-35
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• 2022

Purpose: The purpose of this study was to investigate the influencing factors on health-related quality of life according to body mass index (BMI) in middle age people. Methods: Using the 2017 Korea Health Panel Data, a total of 4,711 subjects age 40-64 were selected and classified into four groups based on BMI levels (underweight, normal weight, overweight, obese). Influencing factors according to BMI in middle age people was analyzed using multiple regression. Results: Activity limited was the most influential factor for health-related quality of life in middle age people. Walking and stress were factors influencing health-related quality of life in all weight groups. In the overweight and obese group, suicidal impulse was a significant influencing factor on health-related quality of life. Conclusion: To improve the health-related quality of life of middle age people, effective walking and stress management for maintaining and managing health, as well as managing suicide risk in the overweight group and obese group are required.

• Journal of Preventive Medicine and Public Health
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• v.46 no.5
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• pp.226-236
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• 2013

Objectives: The aim of this study was to examine the levels of serum 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and evaluate their association with age, body mass index, smoking, military record-based variables, and estimated exposure to Agent Orange in Korean Vietnam veterans. Methods: Serum levels of TCDD were analyzed in 102 Vietnam veterans. Information on age, body mass index, and smoking status were obtained from a self-reported questionnaire. The perceived exposure was assessed by a 6-item questionnaire. Two proximitybased exposures were constructed by division/brigade level and battalion/company level unit information using the Stellman exposure opportunity index model. Results: The mean and median of serum TCDD levels was 1.2 parts per trillion (ppt) and 0.9 ppt, respectively. Only 2 Vietnam veterans had elevated levels of TCDD (>10 ppt). The levels of TCDD did not tend to increase with the likelihood of exposure to Agent Orange, as estimated from either proximity-based exposure or perceived self-reported exposure. The serum TCDD levels were not significantly different according to military unit, year of first deployment, duration of deployment, military rank, age, body mass index, and smoking status. Conclusions: The average serum TCDD levels in the Korean Vietnam veterans were lower than those reported for other occupationally or environmentally exposed groups and US Vietnam veterans, and their use as an objective marker of Agent Orange exposure may have some limitations. The unit of deployment, duration of deployment, year of first deployment, military rank, perceived self-reported exposure, and proximity-based exposure to Agent Orange were not associated with TCDD levels in Korean Vietnam veterans. Age, body mass index and smoking also were not associated with TCDD levels.

• The Journal of Internal Korean Medicine
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• v.41 no.3
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• pp.434-446
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• 2020

Objectives: The cardio-ankle vascular index (CAVI) and ankle-brachial index (ABI) are non-invasive methods to evaluate cardiovascular disease and arteriosclerosis. This study investigated the relationship between CAVI, ABI, and factors related to arteriosclerosis. Methods: This study included 535 healthy adults who underwent health examinations in 2019. We analyzed the correlation between CAVI, ABI and clinical variables. Multiple regression analysis was performed on the independent clinical variables associated with CAVI and ABI. Results: The correlation analysis of CAVI showed that body mass index (BMI) and HDL-cholesterol (HDL-C) had a negative correlation, and the other variables had a significant positive correlation. The correlation analysis with ABI on the right side showed that age, diastolic blood pressure (DBP), gender, and LDL-cholesterol (LDL-C) had a significant positive correlation, while HDL-C had a significant negative correlation. There was no statistical significance on the left. In the multiple regression analysis, DBP, age, BMI, gender, and HDL-C were proved to be independent factors in CAVI (right) (R²=0.365); DBP, age, gender, BMI, fasting blood sugar, and total cholesterol in CAVI (left) (R²=0.357); and age, gender, DBP, and systolic blood pressure in ABI (right) (R²=0.133). There were no statistically significant factors in ABI (left). It could be inferred that smoking and drinking are determinants that play an important role in CAVI. Conclusion: CAVI showed a high correlation with gender, age, and blood pressure. A significant correlation between CAVI and serum lipid values could be observed, but this showed a low correlation coefficient. ABI showed a high correlation with age and DBP. These results support the use of CAVI and ABI as primary diagnostic devices in medical treatment.

• The Research Journal of the Costume Culture
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• v.11 no.1
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• pp.153-164
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• 2003

For this study, 148 female adults between the ages of 20 and 60 who satisfied the plus-size judgment criteria took part in this study. Criteria were Rohrer index is higher than 1.5, bust girth larger than 90cm, and RBW(relative body weight) index higher than 110. Using anthropometric measurement values, indirect measurement values, and index values, this study analyzed frequencies, Duncan multiple range, and ANOVA to obtain information on characteristics that determine a representative body shape, by age, 1'3r Plus-sized women. The results are as follows: Physical Characteristics of Pius-Sized Women by Their Age: Women in their 20s md 30s had broader shoulders with smaller waists, with large buttocks and thighs. Among women in their 50s and 60s, body fat level increased significantly in regions such as the chest and abdomen, which made their upper body heavier.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.311-316
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• 2002

The following results are achieved from a mortar flow test depending on stainless steel slag fineness, rate of replacement, and a research on material age compressive strength, strength activity index. 1. Flow is proportional to the stainless steel slag fineness. 2. Mixing stainless steel slag decreases compressive strength 3. Material age compressive strength has the maximum value when stainless steel slag fineness is 6000$cm^2$/g. 4. Material age 7day strength activity index satisfies KSCE 95-01 at all conditions except the case of fineness 8000$cm^2$/gㆍstainless steel slag rate of replacement 30%. 5. Material age 28day strength activity index satisfies KSCE 95-01 in case of stainless steel slag fineness 4000$cm^2$/gㆍrate of replacement 10%, fineness 6000$cm^2$/gㆍ10%, or 20%.