• Journal of Korean Society of Forest Science
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• v.103 no.4
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• pp.670-678
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• 2014

This paper analyzes the characteristics of population change and makes the population projection in the mountainous area of Korea. Mountainous areas are defined as local towns (eup or myeon) with forest area more than 70 percent of land area, population density less than 111 people per square kilometer, and plowland area less than 21 percent of land area. The population in mountainous areas has decreased dramatically, while the ageing index has increased over the past two decades. To make the population projection, the cohort-change ratios method is applied. The results revealed that a multitude of young people aged 10 to 39 moved to cities to find education and job chance and some people aged 40 and over moved to mountainous areas as the trends of urban-to-rural migration. This continuing trend will culminate in 680 thousand people in population and 1,035 of ageing index in 2030, which will lead to the unequal land development and inefficient forest management. Thus, policy makers need to develop stimulus plans to revitalize and stabilize the economy of mountainous areas.

• Nutrition Research and Practice
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• v.1 no.3
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• pp.231-236
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• 2007

Underreporting patterns by the level of obesity have not been fully assessed yet. The purpose of this study was to examine the differential underreporting patterns on cardiovascular risk factor, macronutrient, and food group intakes by the level of Body Mass Index (BMI). We analyzed cross-sectional baseline nutritional survey data from the population-based longitudinal study, the Healthy Women Study (HWS) cohort. Study subjects included 538 healthy premenopausal women participating in the HWS. Nutrient and food group intakes were assessed by the one-day 24-hour dietary recall and a semi-quantitative food frequency questionnaire, respectively. The ratio of reported energy intake (EI) to estimated basal metabolic rate (BMR) was used as a measure of relative energy reporting status and categorized into tertiles. Overweight group ($BMI{\geq}25kg/m^2$) had a higher ratio of EI to BMR (EI/BMR) than normal weight group ($BMI<25kg/m^2$). Normal weight and overweight groups showed similar patterns in cardiovascular risk factors, nutrient intake, and food group intake by the EI/BMR. Fat and saturated fat intakes as a nutrient density were positively associated with the EI/BMR. Proportion of women who reported higher consumption (${\geq}4\;times/wk$) of sugar/candy, cream and red meat groups was greater in higher tertiles of the EI/BMR in both BMI groups. Our findings suggest similar patterns of underreporting of cardiovascular risk factors, and macronutrient and food group intakes in both normal and overweight women.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.7034-7042
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• 2015

The purpose of this study was to investigate the effects of metabolic syndrome(MS) on quality of life(QoL) using the Korea National Health and Nutrition Examination Survey of 2013. We analyzed data for 4,890 adults, aged 19 year or older and provided the correct data about MS and QoL. MS was defined by the National Cholesterol Education Program-Adult Treatment Panel III with Korea-specific waist circumference cutoffs and QoL was measured by the EuroQol 5-dimension(EQ-5D). The prevalence of MS was 22.1% and high density lipoprotein(HDL)-cholesterol was the highest prevalence in MS components. The mean of EQ-5D index was significantly lower in subject with MS compared to subjects without MS. Among MS components, only higher waist circumference led to EQ-5D index decreasing and the regression coefficient was -0.018. In conclusion, we suggest the attention to QoL and intervention program for improving the QoL in subjects with MS.

• Journal of KIISE
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• v.45 no.3
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• pp.294-302
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• 2018

With the emergence of the new service industry due to the development of information and communication technology, cyber space risks such as personal information infringement and industrial confidentiality leakage have diversified, and the security problem has emerged as a critical issue. In this paper, we propose a behavior-based anomaly detection method that is suitable for real-time and large-volume data analysis technology. We show that the proposed detection method is superior to existing signature security countermeasures that are based on large-capacity user log data according to in-company personal information abuse and internal information leakage. As the proposed behavior-based anomaly detection method requires a technique for processing large amounts of data, a real-time search engine is used, called Elasticsearch, which is based on an inverted index. In addition, statistical based frequency analysis and preprocessing were performed for data analysis, and the DBSCAN algorithm, which is a density based clustering method, was applied to classify abnormal data with an example for easy analysis through visualization. Unlike the existing anomaly detection system, the proposed behavior-based anomaly detection technique is promising as it enables anomaly detection analysis without the need to set the threshold value separately, and was proposed from a statistical perspective.

• Journal of Korean Society on Water Environment
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• v.33 no.6
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• pp.626-639
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• 2017

Based on an ecological monitoring in a Korean stream (Gapyeong), Habitat Suitability Index (HSI) of nine fish species was developed for three physical habitat factors : current velocity, water depth and substrate. The species were chosen based on their abundance and frequency in the fish community of the Gapyeong stream. The Weibull model was used as the probability density function to analyze the distribution and number of each fish species according to the three identified physical factors, which showed good results. This HSI equation has advantages because it statistically expresses habitat preferences of fish species simply and clearly. From that, we can quantitatively deduce the central tendency and variation of environmental factors for fish distribution. The selected fish species showed different preferences for each habitat factor respectively. Although there are some exceptions, the distribution and abundance of individual species of nektonic fish (Zacco koreanus, Zacco platypus, Microphysogobio longidorsalis and Pungtungia herzi) were positively skewed to deep water and fine substrate while riffle-benthic fish (Koreocobitis rotundicaudata and Coreoleuciscus splendidus) were normally distributed at the shallow and coarse substrate zone. It seems that the species showing the positively skewed distribution to the current, Z. koreanus, Z. platypus, M. longidorsalis and P. herzi have adapted themselves to the fast current and have expanded their niche.

• Journal of Nutrition and Health
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• v.37 no.3
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• pp.210-222
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• 2004

In recent years, the number and proportion of Korean elderly have grown rapidly, and elderly individuals show a disproportionate risk for poor nutritional status. The purpose of this study was to examine the relationship of sociodemographic background to nutrient intake of persons 65 years of age or older, living in 15 cities in Korea. Data on 1973 subjects (603 males, 1370 females), who participated in the Korean Elderly Nutrition Survey (2000), were analyzed. Their mean age was 72.3 years and their mean body mass index (BMI) was 24.2 kg/$m^2$. Basic sociodemographic data were obtained through personal interviews. The 98-item semi-food frequency questionnaire, developed and previously validated for Korean middle-aged and elderly subjects, was administered. “Percentage of subjects who consumed under 75％ Korean RDA,” “number of nutrients consumed below 75％ Korean RDA,” “mean nutrient adequacy ratio,” and “nutrient density” were used to determine nutritional status. Male elderly had better nutritional quality than female elderly. Nutritional quality decreased with age, especially in older elderly (over 75). Elderly who were underweight (BMI 〈 20 kg/$m^2$) showed poorer nutritional quality than those who were normal weight (BMI 20∼25 kg/$m^2$) and overweight (BMI $\geq$ 25 kg/$m^2$). Elderly who lived alone had significantly poorer nutritional quality than those who lived with a spouse, and/or with children. Lower education level and economic dependence also showed lower nutritional quality. A stepwise multiple regression analysis was performed to examine the effects of specific sociodemographic factors on nutritional quality. For number of nutrients under 75％ RDA as a dependent variable, education level explained 4.8％ of the variance, followed by living status, age, body mass index, gender, and living expense support (Model $R^2$ = 0.091). For mean nutrient adequacy ratio as a dependent variable, model $R^2$ was 0.098. Therefore, sociodemographic variables such as gender, age, body mass index, living status, educational level, and economic status influenced elderly nutrition status. These results indicate that an elderly nutrition intervention should focus on subjects who are poorly educated, living alone, age 75 or older, and/or underweight.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.1
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• pp.37-51
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• 2021

The purpose of this research is to develop the Habitat Suitability Index (HSI) for habitat environments of Aix galericulata (A. galericulata) and Dendrocopos major (D. major), which tend to inhabit urban environments. A. galericulata and D. major are the keystone species representing the ecosystem of wetlands and forests. Based on the analysis of their urban habitat environments, this study selects artificially adjustable levels of the environmental index in order to produce the HSI model, which can be used when either restoring or creating the urban habitats for these species. To develop the HSI, we conducted field surveys at Jungnangcheon Stream, Changgyeonggung, Jangneung, Bangbae Neighborhood Park, Gildong Ecological Park, and Seodalsan Mountain. These surveys were conducted between April and August 2020, and this period includes the breeding season of both A. galericulata and D. major. Based on our findings from the surveys, we conclude that there are six SI factors for A. galericulata. These include (1) the presence of alluvial islands, (2) waterfront vegetation cover rate, (3) type of aquatic plants for food, (4) size of forest patch, (5) type of trees in nearby forests, and (6) connectivity of waterfront and forest. We also conclude that there are five SI factors for D. major, which include (1) size of forest patch, (2) rate of broadleaf trees in forest patches, (3) type of nesting trees, (4) diameter at breast height (DBH) of nesting trees, and (5) density of dead trees. The result of this research can provide future studies with useful guidance when both (1) comparing the habitat suitability of the target species in different environments and (2) restoring or creating habitats for these species.

• Journal of Advanced Navigation Technology
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• v.25 no.3
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• pp.177-184
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• 2021

This paper proposes an assessment method using probability-based index for safe and successful underwater docking of autonomous underwater vehicles(AUVs) to the docking stations(DSs). The proposed method assesses the probability of docking according to the degree to which the state of the AUV is consistent with the state criteria for docking. The assessment is performed within a specific area considering the kinematic constraints and docking plans of the AUV. The assessment process is defining probability density function, calculating probabilities for reaching the docking station according to the difference to position and heading criteria, and computing the probability-based index in real-time. We verify the validity of the proposed method through analyzing the data acquired on operation test.

• Journal of Ecology and Environment
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• v.46 no.4
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• pp.324-333
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• 2022

Background: The Korean scarlet dwarf, Nannophya koreana Bae (Odonata: Libellulidae), is anendangered dragonfly with an increasing risk of extinction owing to rapid climate changes and human activities. To prevent extinction, the N. koreana population and their habitat should be protected. Therefore, suitable habitat evaluation is important to build the N. koreana restoration project. The habitat suitability index model (HSI) has been widely used for habitat evaluation in diverse organisms. Results: To build a suitable HSI model for N. koreana, 16 factors were examined by seven experienced researchers. A field survey for N. koreana observed sites and spatial analysis were conducted to improve the model. Five factors were finally selected by this procedure (crown density, open water surface, water depth, pioneer plant cover, and type of water source). Finally, the N. koreana HSI model was generated with the five adjusted factors based on interview, field survey, and spatial analysis. This model was validated by a current N. koreana habitat in 2021. With this model, 46 sites in Uljin-gun, Korea, were surveyed for N. koreana habitats; five sites were identified as core habitats and seven as potential core habitats. Conclusions: This model will serve as a strong foundation for the N. koreana restoration project and as a reference for future studies on N. koreana and other endangered insect populations. Further analysis and long-term data will improve the efficacy of this model and restore endangered wildlife.

• Korean Journal of Materials Research
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• v.32 no.12
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• pp.560-564
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• 2022

In this study, lanthanum boron silicate glasses were prepared with a composition of x Li₂O-(60-x)B₂O₃-5CaO-5BaO-7ZnO-10SiO₂-10La₂O₃-3Y₂O₃ where x = 1,3,5,7, and 9 mol%. Each composition was melted in a platinum crucible under atmospheric conditions at 1,400 ℃ for 2 h. Clear glasses with a transmittance exceeding 85 % were fabricated. Their optical, thermal, and physical properties, such as refractive index, Abbe number, density, glass transition (T_g) and Knoop hardness were studied. The results demonstrated that refractive index was between 1.6859 and 1.6953 at 589.3 nm. The Abbe number was calculated using an equation for 589.3 nm (nd), 656.3 nm (nf) and 486.1 nm (nc) and was observed to be in the range from 57.5 to 62.6. As the Li₂O content increased, the glass transition temperature of the optical glass decreased from 608 ℃ to 564 ℃. If glass mold pressing is performed using a material with a low transition temperature and high mechanical strength, then the optical glasses developed in this study can be completely commercialized.