• Korean Journal of Applied Biomechanics
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• v.27 no.1
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• pp.1-7
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• 2017

Objective: The purpose of this study was to analyze the relationship between ground reaction force (GRF) and attack time according to the position of hand segments during counter attack in Kendo. Method: The participants consisted of 10 kendo athletes (mean age: $21.50{\pm}1.95yr$, mean height: $175.58{\pm}5.02cm$, mean body weight: $70.96{\pm}9.47kg$) who performed standard head strikes (A) and counter attack with a preferred hand position of +10 cm (B), 0 cm (C), and -10 cm (D). One force-plate (AMTI-OR-7., USA) was used to collect GRF data at a sample rate of 1,000 Hz. The variables analyzed were the attack time, medial-lateral GRF, anterior-posterior GRF (AP GRF), peak vertical force (PVF), and loading rate. Results: The total attack time was shorter in types A and C than in types C and D. The AP GRF, PVF, and loading rate had significantly higher forces in types C and D than in types A and C. The attack time (bilateral and unilateral leg support and total) was positively correlated with the GRF variables (vertical GRF and loading rate) during the counter attack in Kendo (r = 0.779 [$R^2=0.607$], p < 0.001). Conclusion: The positions of the hand segments can be changed by various conditions of the opponent in Kendo competitions; however, the position preferred by an individual can promote the successful ratio of the counter attack.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.4
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• pp.337-344
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• 2017

To date, no clear threshold that has been established for defining an adequate store of vitamin D for bone health. Therefore, this study aims to determine the required level of vitamin D to maintain a healthy skeleton based on bone remodelling process among healthy adult population. This was a cross sectional study, involving a healthy adult population in Kota Bharu, Malaysia, aged 18~50 years. We measured serum 25(OH)D (vitamin D), serum parathyroid hormone (PTH), serum C-terminal telopeptide of type 1 collagen (CTX), and Procollagen 1 Intact N-Terminal (P1NP) in 120 healthy adults selected via multi stage sampling (64 males, 56 females) from 6 subdistricts in Kota Bharu. The mean level of 25(OH)D was 23.50 (${\pm}8.74$) nmol/L. There was a significant difference of the vitamin D level between genders ($26.81{\pm}8.3nmol/L$ vs $19.72{\pm}7.68nmol/L$ in males and females respectively) (p value<0.001). More than 50% of female subjects had 25(OH)D less than 20 nmol/L, while only 20.3% of male subjects had 25(OH)D below 20 nmol/L. Based on the LOESS plot, the bone turnover markers showed a plateauing result, at the 25(OH)D level of 35 nmol/L for CTX and 20 nmol/L for P1NP. Contrastingly, PTH showed a step rise in the 25(OH)D level of 20 nmol/L. Based on the LOESS plot for CTX, P1NP and PTH versus 25(OH)D, level of vitamin D between 20 to 35 nmol/L is recommended to maintain healthy skeleton.

• Journal of Korean Academy of Oral Health
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• v.42 no.4
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• pp.167-174
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• 2018

Objectives: The aim of this study was to analyze the accessibility of dental care services among individuals with precarious employment in South Korea. Methods: We used the $9^{th}$ wave of the Korean Health Panel data (2015) and included 7,736 wage and non-wage earners in our study. We determined precariousness in the labor market as a combination of employment relationship and job income, and categorized individuals based on this into the following four groups: Group A comprising those who report job and income security, Group B comprising those who experience job insecurity alone, Group C comprising those who report a stable job but low income, and Group D comprising those who experience both job and income insecurity. Accessibility to dental care services was determined by experience of unmet dental care needs and unmet dental care needs caused primarily by financial burden. Logistic regression analyses were used to assess the effect of precarious work on access to dental care services. Results: Individuals with job insecurity (Group B; OR=1.445; 95% CI=1.22-1.70) and both job and income insecurity (Group D; OR=1.899; 95% CI=1.61-2.24) were more likely to have unmet needs than the comparison group. Both groups B and D were also 2.048 (95% CI=1.57-2.66) times and 4.435 (95% CI =3.46-5.68) times more likely, respectively, to have unmet dental care needs caused by financial burden. Education status, health insurance, and health status were all also effective factors influencing unmet dental care needs. Conclusions: Unstable employment and low income resulted in diminished access to dental care services. Therefore, governments should consider health policy solutions to reduce barriers preventing individuals with employment and income instability from accessing adequate dental care.

• The Journal of the Korea Contents Association
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• v.22 no.4
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• pp.677-688
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• 2022

Precarious employment is negatively associated with mental health including depression. The aim of the study is to suggest the multidimensional definition of precarious employment and examine its impacts on depression. Using the fifth save of the Korean Working Condition Survey, we first measured six different dimensions of employment precariousness: temporariness, disempowerment, vulnerability, difficulty exercising rights, unpredictability of working times, and low wage. All of six precariousness indicators consisted of a scale from 0 to 100. Then, we conducted logistic regression to examine the association between employment precariousness and depression. For men, the risk of depression increased by 3.1%, 1%, and 0.5%, respectively, for each one point increase in vulnerability, difficulty in exercising rights, and unpredictability of working times. For women, the risk increased by 0.5%, 2.3%, and 0.8%, respectively, for each one point increase in temporariness, vulnerability, and difficulty in exercising rights. Our findings suggest that not only a secure employment contract, but also their substantive labor rights should be guaranteed for health for workers.

• Journal of Species Research
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• v.5 no.1
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• pp.179-187
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• 2016

As a subset investigation to discover indigenous prokaryotic species in Korea, a total of 21 bacterial strains assigned to the class Betaproteobacteria were isolated from a wide range of environmental samples which collected from fresh water, roots of plants, mineral water and soil from ginseng farm. Phylogenetic analysis based on 16S rRNA gene sequences indicated that 21 isolated strains were most closely related to the class Betaproteobacteria, with high 16S rRNA gene sequence similarity (>99.1%) and constructed a robust phylogenetic clade with the closest species in the class Betaproteobacteria. These isolated species have no previous report or publication in Korea; therefore 17 species in 14 genera of 6 families in the order Burkholderiales, 1 species in the order Methylophilales, 2 species in 2 genera of 1 family in the order Neisseriales are reported for betaproteobacterial species found in Korea. Gram reaction, colony and cell morphology, basic biochemical characteristics, isolation source, and strain IDs are also described in the species description section and as an image.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.9
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• pp.1014-1020
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• 2009

In this paper, a novel UWB(Ultra Wide-band) antenna with suppressed band of IEEE 802.11a($5.15{\sim}5.825\;GHz$) WLAN was designed and fabricated by using SRR(Split Ring Resonator) with band rejection property. MWS(Micro-wave Studio) of CST company was utilized in the design stage. The antenna was fabricated on a substrate, Rogers 4003, with the thickness of 0.8 mm and relative permittivity of 3.38. The measured result shows that the proposed antenna has a good return loss below -10 dB and group delay below 1nsec over UWB communication band($3.1{\sim}10.6\;GHz$) except WLAN band. It also shows the omni-directional radiation pattern.

• Magazine of the Korea Concrete Institute
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• v.4 no.1
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• pp.81-87
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• 1992

In this thesis, the fatigue tests were performed on a series of SFRC(steel fiber reinforced concrete) to investigate the fatigue behavior of SFRC varying with the steel fiber contents and the steel fiber aspect ratios. The three point loading system is used in the fatigue tests. In tl1ese tests, relations between the repeated loading cycles and the mid-span deflections, number of repeated loadmg cycles when specimen was fractured were observed. On this basis, the mid-span deflections, the elastic strain energy and inelastic strain energy of SFRC were studied. A S - N curve \vas drawn to present the fatigue strength of SFRC beam. From che test results, by increasing the steel fiber content the energy lost on the permanent deformation decreases and the energy spent on crack growth increases. But in case of SFRC with the same steel fiber content the higher the steel fiber aspect ratio is, the less the elastic strain energy is. According to S - N curve drawn by the regression analysis on the fatugue test results, the fatigue strength with 2,000,000 repeated loading cycles in SFRC with the steel fiber content is 1.0% shows about 70% on the first crack static flexural strength.

• The Journal of Korean Society for School & Community Health Education
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• v.20 no.2
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• pp.37-51
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• 2019

Purpose: This study aims to substantiate a correlation between the period of living alone in a shabby one-room and a depression experience. Methods: We conducted a cross-sectional study using data from the Korea Homeless Survey carried out by the Korea Institute for Health and Social Affairs in 2016. In the study, the data included 485 survey participants who resided in a single room. The period of single-room occupancy being divided into three groups: less than 1 year, 1 to 4 years, and more than 5 years was considered a primary independent variable. The outcome variable which represented a depression experience was measured by CESD-11(The Center for Epidemiological Studies-Depression Scale). We carried out a Chi-square test and multiple logistic regression to evaluate the association. Results: The rate of depression experienced in this population was 77.5%. Almost 83.9% of the participants were reported as being unable to receive the mental health counselling in the last 12 months. After controlling for covariates, subjects who were living in a single room occupancy for 1-5 years(OR=3.89; 95% CI=1.43-10.56) and more than 5 years(OR=2.71; 95% CI= 1.05-6.95) were found to be more likely to experience depression. Conclusions: The results showed that living alone in a shabby one-room had a high correlation with experiencing depression. We proposed that there is a need to develop a new strategy for mental health promotion program for the poor, vulnerable and deprived population.

• Journal of Microbiology and Biotechnology
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• v.33 no.11
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• pp.1448-1456
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• 2023

A Gram-positive, non-motile, and non-spore-forming lactic acid bacterium, designated as BK2^T, was isolated from kimchi, a Korean traditional fermented vegetable food, and the taxonomic characteristics of strain BK2^T, along with strain LMG 11983, were analyzed. Both strains optimally grew at 30℃, pH 7.0, and 1.0% NaCl. Cells of both strains were heterofermentative and facultatively anaerobic rods, demonstrating negative reactions for catalase and oxidase. Major fatty acids (>10%) identified in both strains were C_18:1 ω9c, C_16:0, and summed feature 7 (comprising C_19:1 ω6c and/or C_19:1 ω7c). The genomic DNA G+C contents of both strains were 44.7 mol%. The 16S rRNA gene sequence similarity (99.9%), average nucleotide identity (ANI; 99.9%), and digital DNA-DNA hybridization (dDDH; 99.7%) value between strains BK2^T and LMG 11983 indicated that they are different strains of the same species. Strain BK2^T was most closely related to Weissella confusa JCM 1093^T and Weissella cibaria LMG 17699^T, with 100% and 99.4% 16S rRNA gene sequence similarities, respectively. However, based on the ANI and dDDH values (92.3% and 48.1% with W. confusa, and 78.4% and 23.5% with W. cibaria), it was evident that strain BK2^T represents a distinct species separate from W. confusa and W. cibaria. Based on phylogenetic, phenotypic, and chemotaxonomic features, strains BK2^T and LMG 11983 represent a novel species of the genus Weissella, for which the name Weissella fermenti sp. nov. is proposed. The type of strain is BK2^T (=KACC 22833^T=JCM 35750^T).

• Korean Journal of Applied Biomechanics
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• v.24 no.1
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• pp.43-50
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• 2014

The purpose of this study was to analyze of the GRF (ground reaction force) parameters according to the change of positions and weights of bag during downward stairs between dominant and non-dominant in upper & lower limbs. To perform this study, participants were selected 9 healthy women (age: $21.40{\pm}0.94yrs$, height: $166.50{\pm}2.68cm$, body mass: $57.00{\pm}3.61kg$, BMI: $20.53{\pm}1.03kg/m^2$), divided into 2 carrying bag positions (dominant arm/R, non-dominant arm/L) and walked with 3 type of bag weights (0, 3, 5 kg) respectively. One force-plate was used to collect GRF (AMTI OR6-7) data at a sample rate of 1000 Hz. The variables analyzed were consisted of the medial-lateral GRF (Fx), anterior-posterior GRF (Fy), vertical GRF (Fz), impact loading rate and center of pressure (COPx, COPy, COP area, COPy posterior peak time) during downward stairs. 1) The Fx, Fy, Fz, COPx, and COP area of GRF were not statistically significant between dominant leg and non-dominant leg, but non-dominant leg, that is, showed the higher COPy, and showed higher impact loading rate than that dominant leg during downward stairs. 2) In bag wearing to non-dominant arm, Fx, Fz, COPx, COPy, impact loading rate and COP area showed increase tendency according to increase of bag weights. Also, against bag wearing to dominant arm, non-dominant showed different mechanism according to increase of bag weights. The Ground Reaction Force parameters showed different characteristics according to the positions and weights of bag during downward stairs between dominant and non-dominant arm.