• Journal of Preventive Medicine and Public Health
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• v.49 no.1
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• pp.45-52
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• 2016

Objectives: Previous large-scale cohort studies conducted in Korea have found a positive association between diabetes mellitus (DM) and colorectal cancer (CRC) in men only, in contrast to studies of other populations that have found significant associations in both men and women. Methods: A total of 1070 CRC cases and 2775 controls were recruited from the National Cancer Center, Korea between August 2010 and June 2013. Self-reported DM history and the duration of DM were compared between cases and controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by binary and polytomous logistic regression models. Results: DM was associated with an elevated risk of CRC in both men (OR, 1.47; 95% CI, 1.13 to 1.90) and women (OR, 1.92; 95% CI, 1.24 to 2.98). This association remained when we controlled for age, body mass index, alcohol consumption, and physical activity level. In sub-site analyses, DM was associated with distal colon cancer risk in both men (multivariate OR, 2.04; 95% CI, 1.39 to 3.00) and women (multivariate ORs, 1.99; 95% CI, 1.05 to 3.79), while DM was only associated with rectal cancer risk in women (multivariate OR, 2.05; 95% CI, 1.10 to 3.82). No significant association was found between DM and proximal colon cancer risk in either men (multivariate OR, 1.45; 95% CI, 0.88 to 2.41) or women (multivariate OR, 1.79; 95% CI, 0.78 to 4.08). Conclusions: Overall, DM was associated with an increased risk of CRC in Koreans. However, potential over-estimation of the ORs should be considered due to potential biases from the case-control design.

• Journal of The Korean Association For Science Education
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• v.38 no.3
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• pp.419-430
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• 2018

The purpose of this study is to develop an assessment tool to evaluate student character competence in applying a Collaborative Problem-Solving Instruction Model in science education. Through the literature analysis, nine elements of character are extracted. They are: openness, empathy, tolerance, caring, integrity, self-regulation, honesty, responsibility, and cooperation. Based on these existing measures of character competence, experts discussed and developed items for evaluation of a student's character competence based on the Collaborative Problem-Solving Instruction Model. The first 88 preliminary items were investigated, corrected, and supplemented based on the results of the first survey. A second validity survey was conducted on 71 middle- and high school science teachers to determine the content validity of the items. Inter-rater reliability was calculated for the assessors to verify the reliability of the items. Overall, the inter-rater reliability and content validity of the assessment items are good with 53 items ultimately being selected based on the analysis results. The assessment tool developed in this study could be used to explore changes in student character competence through a Collaborative Problem-Solving Instruction Model, as well as to evaluate student character competence in science education.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.10
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• pp.566-573
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• 2016

In order to support effective usage of groundwater as an alternative water resource in future, we investigated distribution characteristics of minerals related with human health. While recent studies tended to focus on small scale, this study broadened research area up to nationwide scale to understand groundwater hydrology and regional, geological distributions of minerals in wide area; we investigated mineral distributions of national groundwater monitoring networks, developed GIS-based mineral maps, and reviewed correlation with geological features. As a result, calcium showed the highest concentration among 5 minerals (Ca, Mg, Na, K, Si) and potassium showed the lowest. Calcium concentration in limestone and sedimentary zone was the highest, and that in pore-volcanic-rock zone was the lowest. While calcium, magnesium and sodium showed differences in concentrations in intrusive-igneous-rock and sedimentary zone, potassium was not within geological features. When we studied regional differences, there were no tendency, but Jeju and Gangwon area showed differences in concentrations of calcium and silica.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.9
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• pp.511-516
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• 2015

On this study, we investigated the removal characteristics of residual chlorine and DBPs in tap-water during boiling. Also we investigated the releasing characteristics of essential minerals in infusion tea. While recent studies focused on removal mechanisms of harmful heavy metals in infusion tea, this study tried to suggest the way to drink tap-water healthier and safer by examining releasing mechanisms of essential minerals in infusion tea. As a result, residual chlorine(initial conc. was 0.7 mg/L) was all removed in 20 minutes after heating and DBPs (the sum of THMs, HAAs and CH) were removed up to 65%. 6 kinds of essential minerals (Ca, K, Na, Mg, S, P) were released from 5 kinds of infusion tea (barley tea, corn tea, brown rice tea, cassia seed tea, solomon's seal tea) on the market. In cassia seed tea, the amount of essential minerals released from tea showed the highest values, 9.6 mg/g, and brown rice tea was the lowest, 1.6 mg/g. Particularly, the released amounts of potassium, playing a key role in human body in maintaining normal blood pressure, cell metabolism and enzyme action, showed relatively high. Through this study, we got to know that essential minerals can be obtained up to 40% of recommended nutritional intake for Korean by boiling tap-water with infusion tea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.10
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• pp.1178-1185
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• 2017

Two types of kimchi with a different total acidity (TA, 0.75% or 1.19%) were heated at $100^{\circ}C$ for up to 60 min to develop a gratin added with heated-kimchi. Their browning index and color intensity increased with increasing heating time, which was more apparent for the kimchi with the higher TA. This was attributed to the Maillard reaction facilitated at a higher heat intensity and by the smaller fermentation products. The same tendency was also observed for the antioxidant activities determined by the total reducing capacity, metal-chelating activity, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. In particular, heating kimchi at $100^{\circ}C$ only for 10 min increased the activities significantly. Therefore, the heated-kimchi was added to gratin at 20%. With the addition, the dietary fiber, ${\gamma}-aminobutyric$ acid (GABA) and ornithine contents in the gratin were increased appreciably (P<0.01). Nevertheless, there was little change in its salinity. The antioxidant activities of the gratin were significantly (P<0.001) higher than the control gratin without kimchi, with DPPH radical scavenging activity being 3.6 times higher. The results suggest that the functionality of kimchi could be effectually added to gratin even after heat treatment.

• Journal of Radiation Protection and Research
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• v.42 no.4
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• pp.197-204
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• 2017

Background: X-ray imaging detectors for the nondestructive cargo container inspection using MeV-energy X-rays should accurately portray the internal structure of the irradiated container. Internal and external factors can cause noise, affecting image quality, and scattered radiation is the greatest source of noise. To obtain a high-performance transmission image, the influence of scattered radiation must be minimized, and this can be accomplished through several methods. The scatter rejection method using an anti-scatter grid is the preferred method to reduce the impact of scattered radiation. In this paper, we present an evaluation the characteristics of the signal and noise according to physical and material changes in the anti-scatter grid of the imaging detector used in cargo container scanners. Materials and Methods: We evaluated the characteristics of the signal and noise according to changes in the grid ratio and the material of the anti-scatter grid in an X-ray image detector using MCNP6. The grid was composed of iron, lead, or tungsten, and the grid ratio was set to 2.5, 12.5, 25, or 37.5. X-ray spectrum sources for simulation were generated by 6- and 9-MeV electron impacts on the tungsten target using MCNP6. The object in the simulation was designed using metallic material of various thicknesses inside the steel container. Using the results of the computational simulation, we calculated the change in the scatter-to-primary ratio and the signal-to-noise ratio improvement factor according to the grid ratio and the grid material, respectively. Results and Discussion: Changing the grid ratios of the anti-scatter grid and the grid material decreased the scatter linearly, affecting the signal-to-noise ratio. Conclusion: The grid ratio and material of the anti-scatter grid affected the response characteristics of a container scanner using high-energy X-rays, but to a minimal extent; thus, it may not be practically effective to incorporate anti-scatter grids into container scanners.

• Microbiology and Biotechnology Letters
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• v.42 no.1
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• pp.41-50
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• 2014

In this study, the performances of PVA-encapsulation and non-encapsulation in a fed-batch bioreactor system were compared for biohydrogen production. Hydrogen production in the PVA-encapsulation bioreactor was not significantly different in comparison to the non-encapsulation bioreactor. However, the hydrogen gas in the encapsulation bioreactor could be stably produced when it was exposed to environmental difficulties such as pH impact by the accumulation of organic acids as fermentative metabolic products. Bacterial communities by DGGE analysis were differently shifted between the PVA-encapsulation and non-encapsulation bioreactors from the initial sludge. The community of hydrogen producing bacteria was stable during the experimental period in the PVA-encapsulation bioreactor compared to the non-encapsulation method. The absolute quantitation of the DNA copy number by a high-throughput droplet digital PCR system for six genera contributed to hydrogen production showing that the numbers of dominant bacteria existed at similar levels in the two bioreactors regardless of encapsulation. In both of two bioreactors, not only Clostridium and Enterobacter, which are known as anaerobic hydrogen producing bacteria, but also Firmicutes, Ruminococcus and Escherichia existed with $1{\times}10^5-1{\times}10^6$ copy numbers of ml-samples exhibiting rapid growth during the initial operation period.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.1
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• pp.85-92
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• 2017

purpose: Image Guide System offers therapy precise, especially Intensity Modulated Radiation Therapy. However, organs at pelvis have variation and uncertainties each therapy. it brings IG system for verifying patient's position. In this study, analysis the variation at pelvis during rectal cancer radiation therapy. Moreover design the patient re-setup technique and apply to patients. Material and Method: 40 rectal cancer patient who have radiation therapy. The 530 image which acquired from IG system are analyzed. The bone structure, bladder, gas in the rectum, small bowel, soft tissue, weigh loss are evaluated by the criterion. The criterion are classified by best, good, bad and figure out the ratio with count. The re-setup proceed in case of one or over the two get the bad criterion and figure out the ratio of re-setup results: The ideal of therapy ratio is 19.2 % each criterion. And the good for therapy ratio is 54.9 %, the cases of bad for therapy is 25.8 %. The bad cases are have therapy after re-setup with post process. conclusion: Each pre-treatment image that acquired IG system has different results despite of same patients. The 25.8 % need to re-setup in order to unsuitable therapy. It is implies that the IG system is necessary establishing precise treatment plan like IMRT especially rectal cancer.

• Journal of the Korean Chemical Society
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• v.65 no.2
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• pp.151-165
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• 2021

The study applied chemistry classes based on Collaborative Problem-Solving for Competency(CoProC) Instruction Model to 86 high school seniors and recognized the resulting changes in Character Competence through character competence test, analysis of argumentation, and analysis of reflective writing. In addition, the analysis of the correlation between the assessment results showed what each evaluation method meant to assess Character Competence. The study found that the average score of Character Competence rose in all three assessments, but differences were found in the detailed factors. Character competency test is meaningful in helping students participate with a sense of mastery of learning as a self-evaluation, and the analysis of the argumentation process seems to be an appropriate evaluation method to evaluate the Character Competence shown by students' words and actions through course evaluations. An analysis of reflective writing showed the advantage of being able to analyze Character competencies that are difficult to show in action by looking back on the entire course of learning. In addition, given that the correlation between the three assessment results is very low, it is expected that the three Character competency assessment methods will be conducted together to obtain detailed and comprehensive information on students' character competencies.

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.55-62
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• 2021

Purpose: This study aims to contribute to the reduction of complications of breast cancer radiation therapy by analyzing skin dose differences due to Set-up error. Materials and Method: Pseudo breast was produced using a 3D printer, applied to the phantom, and images were acquired through CT. Treatment plan was carried out that the PTV, which contains 95% of the prescription dose, could be more than 95% of the volume, so that Dmax did not exceed 107% of the prescription dose. The Set-up error was evaluated by applying ±1mm/±3mm/±5mm to the X-axis, Y-axis, and Z-axis. Results: The dose-variation in skin due to Set-up error was approximately 106% to 123% compared to prescription dose, and the highest dose in skin was 49.24 Gy at 5mm Set-up error in the lateral direction of the X-axis. More than 107% of the prescription dose was the widest at 6.87 cc in skin lateral. Conclusions: If a Set-up error occurs during left breast cancer VMAT, a great difference in skin dose was shown in the lateral direction of the X-axis. If more effort is made to align the X-axis of the breast treated during CBCT registration, the dose-variation of skin will be reduced.