• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.2
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• pp.109-118
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• 2011

The aims of this study were analyze the amount of stress condition when the traction force was applied to the condyle head from the chin area of mandible and amount of distortion condition when intended 0.5 mm distraction distance from surface or one point of dissected midline of mandible. For this study, 3D finite element analysis were performed. The following results were obtained : 1. When traction force of 500 g was applied to the condyle head from the chin area, condylar neck area showed the greatest amount of stress and coronoid process was the least amount of stress area. For the amount of distortion condition, infra dental area showed the greatest. 2. When 0.5 mm of intended surface distortion was applied after dissection of mid-mandible area, base anterior area showed the greatest amount of stress but the least stress area was coronoid process. For the amount of distortion, infra dental, menton area showed the greatest amount. 3. One point distortion was applied after dissection of mid-mandible area, ramus posterior area showed the greatest amount of stress and menton area were the least stress condition. For the amount of distortion, menton area showed the greatest amount of distortion condition.

• The Journal of the Korea Contents Association
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• v.18 no.8
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• pp.646-657
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• 2018

Purpose: This study is to investigate factors affecting depression in nursing students. Methods: A survey was conducted with 216 nursing students in college at P city, D city, and K province. Data was collected from April 15 to May 21, 2018, and analyzed by descriptive statistics, t-test, one-way ANOVA and hierarchical regression with IBM SPSS Statistics 24.0. Results: There was a significant positive correlation between verbal violence and depression(r=.261, p<.001), between physical threat and depression(r=.291, p<.001). Also, Self-esteem had a significant positive correlation with resilience(r=.685, p<.001) and negative correlation with depression(r=-.590, p<.001). Moreover, resilience had a significant negative correlation with depression(r=-.612, p<.001). In the hierarchical analysis, factors affecting the nursing students' depression were resilience(${\beta}=-.337$, p<.001), self-esteem(${\beta}=-.279$, p<.001), physical threat(${\beta}=.177$, p=.001). The variable that had the highest impact on depression was resilience and the explanatory power of the regression model was 51.5%(F=17.965, p<.001). Conclusion: The findings of this study indicate that the major factors influencing nursing students depression are physical threat, self-esteem and resilience. Therefore, it suggests that an intervention program will be required to prevent violence during the clinical practice, enhances self-esteem and improves resilience in order to reduce depression of nursing students.

• Journal of Microbiology and Biotechnology
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• v.27 no.6
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• pp.1138-1149
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• 2017

The use of microalgal biomass is an interesting technology for the removal of heavy metals from aqueous solutions owing to its high metal-binding capacity, but the interactions with bacteria as a strategy for the removal of toxic metals have been poorly studied. The goal of the current research was to investigate the potential of Burkholderia tropica co-immobilized with Chlorella sp. in polyurethane discs for the biosorption of Hg(II) from aqueous solutions and to evaluate the influence of different Hg(II) concentrations (0.041, 1.0, and 10 mg/l) and their exposure to different contact times corresponding to intervals of 1, 2, 4, 8, 16, and 32 h. As expected, microalgal bacterial biomass adhered and grew to form a biofilm on the support. The biosorption data followed pseudo-second-order kinetics, and the adsorption equilibrium was well described by either Langmuir or Freundlich adsorption isotherm, reaching equilibrium from 1 h. In both bacterial and microalgal immobilization systems in the co-immobilization of Chlorella sp. and B. tropica to different concentrations of Hg(II), the kinetics of biosorption of Hg(II) was significantly higher before 60 min of contact time. The highest percentage of biosorption of Hg(II) achieved in the co-immobilization system was 95% at pH 6.4, at 3.6 g of biosorbent, $30{\pm}1^{\circ}C$, and a mercury concentration of 1 mg/l before 60 min of contact time. This study showed that co-immobilization with B. tropica has synergistic effects on biosorption of Hg(II) ions and merits consideration in the design of future strategies for the removal of toxic metals.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.362-373
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• 2018

This study was conducted to investigate the relationship between interest in smoking cessation and factors that define this interest. The study subjects were 593 male civil servants who work at D metropolitan city and were smokers at the time of the survey. The research method was a survey using a self-administered questionnaire in October 2015. Interest in smoking cessation of study subjects showed that 28.3% had no interest in smoking cessation, 45.7% were interested in smoking cessation, but had no intention to quit within six months, and 26.0% were interested in smoking cessation and intended to quit within six months. Multiple regression analysis revealed that the factors influencing interest in smoking cessation with explanatory powers of 23.6% were employment type, age when first starting smoking, number of cigarettes smoked per day, time from when you wake up until you smoke your first cigarette, recognition of susceptibility to lung cancer, and benefits to smoking cessation. Logistic regression analysis revealed that the odds ratio of recognition of susceptibility for lung cancer, benefits to smoking cessation, and barriers to smoking cessation were significantly increased in the group with interest in smoking cessation and intention to quit within six months vs. the group with no interest in smoking cessation. Taken together, these results suggest that cancer prevention due to smoking and awareness of the seriousness of health problems caused by smoking were factors increasing interest in smoking cessation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.178-185
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• 2018

The low birth rate in South Korea is a very serious problem. Recently, as personal happiness has emerged as an important life value of life, unmarried people have developed a negative tendency toward marriage. This study was conducted to investigate the attitude toward marriage, gender role and having children among college students, and to identify the factors affecting marriage. The participants were 383 unmarried nursing college students who live in D city. Data were collected from self-report questionnaires and analyzed using the t-test, one-way ANOVA, Pearson's correlation coefficients, and stepwise multiple regression using the SPSS 22.0 program. Gender was a significant variable influencing attitude toward marriage. Moreover, the attitude toward marriage was negatively correlated with gender role, and positively correlated with having children. Attitude toward gender role was negatively correlated with having children. Regression analysis of the factors affecting attitude toward marriage showed that gender (male), attitude toward gender role, and attitude toward having children were significant influencing factors. Moreover, this model explained 51.9% of variance in attitude toward marriage. Overall, it is necessary to change individual values to solve the problem of low birthrate.

• Journal of Korean Society of Forest Science
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• v.101 no.2
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• pp.185-194
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• 2012

The purpose of this contribution is to develop the framework of a methodology for identifying potential errors in georeferencing and in an application of it using specimens of Ox-Knee, Achyranthes bidentata Blume in Korea. At infraspecific level, uncertainty of identification showed that 41% of A. bidentata var. japonica and 28% of var. bidentata were misidentified, suggesting that the uncertainty level was independent of the reliability of experts' identification. For georeference specimen records, 71 specimens out of total 303 were selected and utilized as occurrence data: Uncertainty was 32.4 km at maximum and was 0.1297 km at minimum (mean = 4,055 m, s.d. = 5,772 m). Var. japonica is common throughout most of the southeastern Korea and west coastal areas, while var. bidentata has been found as far north as Gyeonggi and Gangwon provinces. We modelled the potential distribution of two varieties using Bioclim approach in Korea based on several environmental factors. Our results indicated the most important region for var. japonica lies the west coast ranges and southern area, while for Chungcheongnam-do of potential high diversity occurs for var. bidentata. This study shows that the major factors to determine the distribution patterns of two varieties were thermal factors, rather than precipitation. The Bioclim model using geocode and georeferencing data makes the information increasingly useful and reliable. To improve data quality, it requires full management from data collection to final databases including data cleaning.

• BMB Reports
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• v.40 no.3
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• pp.315-324
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• 2007

The novel $\alpha$-amylase purified from locally isolated strain, Bacillus sp. KR-8104, (KRA) (Enzyme Microb Technol; 2005; 36: 666-671) is active in a wide range of pH. The enzyme maximum activity is at pH 4.0 and it retains 90% of activity at pH 3.5. The irreversible thermoinactivation patterns of KRA and the enzyme activity are not changed in the presence and absence of $Ca^{2+}$ and EDTA. Therefore, KRA acts as a $Ca^{2+}$-independent enzyme. Based on circular dichroism (CD) data from thermal unfolding of the enzyme recorded at 222 nm, addition of $Ca^{2+}$ and EDTA similar to its irreversible thermoinactivation, does not influence the thermal denaturation of the enzyme and its Tm. The amino acid sequence of KRA was obtained from the nucleotide sequencing of PCR products of encoding gene. The deduced amino acid sequence of the enzyme revealed a very high sequence homology to Bacillus amyloliquefaciens (BAA) (85% identity, 90% similarity) and Bacillus licheniformis $\alpha$-amylases (BLA) (81% identity, 88% similarity). To elucidate and understand these characteristics of the $\alpha$-amylase, a model of 3D structure of KRA was constructed using the crystal structure of the mutant of BLA as the platform and refined with a molecular dynamics (MD) simulation program. Interestingly enough, there is only one amino acid substitution for KRA in comparison with BLA and BAA in the region involved in the calcium-binding sites. On the other hand, there are many amino acid differences between BLA and KRA at the interface of A and B domains and around the metal triad and active site area. These alterations could have a role in stabilizing the native structure of the loop in the active site cleft and maintenance and stabilization of the putative metal triad-binding site. The amino acid differences at the active site cleft and around the catalytic residues might affect their pKa values and consequently shift its pH profile. In addition, the intrinsic fluorescence intensity of the enzyme at 350 nm does not show considerable change at pH 3.5-7.0.

• Korean Journal of Agricultural Science
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• v.11 no.2
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• pp.322-327
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• 1984

As a basic studies for the laboratory scale production of alfalfa inoculum, Rhizobium meliloti M14 was characterized for its carbon and nitrogen sources, and some parameters for broth cultivation in a chemostat were studied by semi-continuous operation. The result s obtained were as follows. 1. Growth rate of the strain was increased by disaccharides than by monosaccharides tested, and pentoses resulted in poor growth than hexoses. Sugar alcohols including inositol supported the best growth among sugars. 2. Mannitol in the yeast-mannitol-broth was substituted by natural carbon sources such as malt extract or molasses. 3. Ten per cent of fresh yeast water appeared to supply enough amount of growth factor s for the strain, and the effect was equivalent to 0.24 percent of the commercial yeast extract powder. 4. Batch growth of the stain in a chemostat, New Brunswick Micro Ferm 28L, reached in the early stationary growth phase of $5{\sim}7{\times}10^9cells/ml$ after 36 hours of incubation. The culture at this stage was switched to semi-continuous cultivation, and the culture broth of four-fifth of the working volume was recovered every 24 hours when the maximal count was obtained.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.26 no.4
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• pp.253-266
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• 2014

The ECOM3D is used to study the circulation characteristics and density current from the Sumjin River runoff in the Kwangyang Estuarine System, South Sea, Korea. Annual mean value of $120m^3/s$ was imposed from the Sumjin River. The numerical model results in terms of tidal height, current and salinity field show satisfactory with skill scores over 90%. The current velocity showed the range of 1~2.5 m/s during flood and ebb phases. In particular, very strong flow occur in the narrow Channels of Noryang, Daebang and Changson exceeding over 2.0 m/s. The tidal residual currents in the various locations in the Kwangyang Estuary showed the range of 1~21 cm/s, The density-driven current through the Yeosu and Noryang Channels are about 12 cm/s and 4 cm/s, respectively. The current path through the Yeosu Channel is deflected toward west Bank. Based on budget analysis of the volume flux, the volume flux through the Yeosu Channel and the Noryang Channel were estimated to be 97.4 and $22.1m^3/s$ accounting for the 81.5% and 18.5% of total flux, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.3
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• pp.322-329
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• 2011

A whole genome association (WGA) study was conducted to identify quantitative trait loci (QTL) for body conformation traits in Hanwoo cattle. The phenotypes of 497 steers were recorded from the Hanwoo Improvement Center of National Agricultural Cooperative Federation, Seosan, Korea, and analyzed using the Illumina Bovine 50 k SNP chip. A set of 35,987 SNPs that were available in the Hanwoo population was selected from the chip. After adjustments for the effects of year-season of birth, region and sire, phenotypes were regressed on each SNP using a linear regression model. Three hundred nineteen SNPs were detected for the ten conformation traits (p<0.003). For the significant SNPs, stepwise regression procedures were applied to determine best sets of markers. A total of 72 SNPs were selected (p<0.001), for which the sets of 5, 9, 10, 9, 8, 11, 4, 6, 3 and 7 SNPs were determined for height at withers, rump height, body length, chest depth, chest width, rump length, hip width, thurl width, pinbone width and heart girth, respectively. About 7-26% of the total phenotypic variation was explained by the set of SNPs for each trait. QTL for the conformation traits were harbored on most bovine chromosomes (BTAs). Four SNPs with pleiotropic effects on height at withers and rump height were detected on BTAs 3, 4, 6 and 16. A SNP with pleiotropic effects on chest width and rump length was also detected on BTA10. Two QTL regions, i.e. between 87 and 97 Mb in BTA3 and between 41 and 44 Mb in BTA7, were found, in which SNPs were detected for the five and three conformation traits, respectively. The detected SNPs need to be validated in other Hanwoo populations for commercial application to the genetic improvement of conformation characteristics in Hanwoo via marker-assisted selection (MAS).