• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.27 no.1
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• pp.23-36
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• 2023

The vector wave equation is widely used in electromagnetic wave analysis. This paper solves the vector wave equation using curl-conforming finite elements. The variational problem is established from Riesz functional based on vector wave equation and the unique existence of weak solution is explored. The edge elements are used in computation and the simulation results are compared with those obtained from a commercial simulator, ANSYS HFSS (high-frequency structure simulator).

• Korean Journal of Health Education and Promotion
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• v.16 no.1
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• pp.1-29
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• 1999

Safety and health education in technical high schools is especially important because the great majority of the students engage in the industrial field after graduation. But there are few reports on the state. of safety and health education in technical high schools in Korea. The aims of this study were to identify the problems of the present safety and health education in technical high schools in Korea and to propose the ways of improving health and safety education. To conduct this study, the textbooks for health and safety related courses, i.e., Introduction to Industry, Gyoryun(dril), and Physical Education, were reviewed. A questionnaire was mailed to the teachers of Introduction to Industry, Gyoryun, Physical Education, and school nurses in 188 technical high schools and the teachers of Gyoryun, Physical Education, and school nurses in 376 general high schools in November 1997. The final response rates were 42.0% for teachers of Introduction to Industry, 62.9% for teachers of Gyoryun, 47.9% for teachers of Physical Education, and 33.0% for school nurses. Also, a survey by self-administered questionnaire on the knowledge, attitude, and practice about safety and health was conducted from May through July 1998 among 44 employees graduated from technical high schools and 44 employees graduated from general high schools since 1995. The analysis of the textbooks showed that the contents of the ‘Industrial Safety and Environment’ section in Introduction to Industry were rather for safety managers than industrial workers and the contents about occupational hygiene and health were scanty. The majority of ‘Accident and Disaster’ and ‘Hazardous Substances’ section in Gyoryun overlapped with those in Introduction to Industry and several mistakes about health related descriptions were found. Some contents of Physical Education. ‘Mental Health’. ‘Emergency Care’. ‘Communicable Disease’, ‘Noncommunicable Disease’, and ‘Food Hygiene’ overlapped with those of Gyoryun. The teachers lectured safety and health related sections of textbook completely in 84.8% for Introduction to Industry, 62.1% for Gyoryun, 20.8% for Physical Education and the most frequent reason for the incomplete education was shortage of time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.173-179
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• 2019

This study aimed to provide basic data for the development of education programs on food hygiene attitude and personal hygiene management of high school students by type of school. From July 16 to October 15, 2015, questionnaires were distributed to 30 students per grade at 16 high schools in Chungcheongnam-do, and a total of 1214 questionnaires (excluding unrecurring and insufficient questionnaires) were processed using SPSS (ver 18.0). As a result, academic high school students answered more checking food's shelf life when they bought it in the store(3.79, 3.60), not eating the cooked and heated food after keeping without heating(2.85, 2.98), and storing food in the refrigerator in accordance with its characteristics(3.90, 3.76) than specialized high school students. Academic high school students were found to be more careful than specialized high school students, to wash hands before meals(3.66, 3.52), after went to toilet(4.30, 3.95), in the right way(3.63 and 3.45), and to go around less during meal time(2.19, 2.43) and to go to the toilet less often during meal time(2.28, 2.47). In this study, academic and specialized high school students showed significant differences in food hygiene attitude and personal hygiene management, and academic high school students had significantly better food hygiene attitude and personal hygiene control than specialized high school students. but still need to be improved. Therefore, it is suggested that education on food hygiene attitude and personal hygiene management should be strengthened according to the type of school.

• Rapid Communication in Photoscience
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• v.4 no.1
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• pp.12-15
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• 2015

Intramolecular photocycloaddition of ferulic acid derivatives proceeded in high yields to give head-to-head intramolecular photodimers as three atropisomers. The photocycloaddition was sensitized by triplet sensitizers such as benzophenone, whereas photocycloreversion was promoted by 9,10-dicyanoanthracene (DCA) as an electron-transfer photocatalyst. On the other hand, intermolecular photocycloaddition afforded a head-to-tail photodimer.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.6
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• pp.267-271
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• 2003

In this work, chemical solution derived Ca-doped zirconia fiber has been prepared by using calcium- and zirconium-naphthenate. Fibrous $ZrO_2$-CaO was drawn from a sticky mixture. Dried gel fibers were finally annealed at $1000^{\circ}C$ for 1 h in argon. 91 mol%$ZrO_2$-9 mol%CaO fiber consisted of tetragonal, monoclinic and $CaZrO_3$ phases after annealing at $1000^{\circ}C$. On the other hand, samples annealed at $500^{\circ}C$ consisted of almost tetragonal single phase. Homogeneous fibers surface at $500^{\circ}C$ became rougher after $1000^{\circ}C$-annealing. The sample annealed at $1000^{\circ}C$ with relatively rough surface structure showed a high Calcium phocphate forming ability.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.2
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• pp.58-65
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• 2021

Meta-heuristic algorithms have been developed to efficiently solve difficult problems and obtain a global optimal solution. A common feature mimics phenomenon occurring in nature and reliably improves the solution through repetition. And at the same time, the probability is used to deviate from the regional optimal solution and approach the global optimal solution. This study compares the algorithm created based on the above common points with existed SA and HS to show advantages in time and accuracy of results. Existing algorithms have problems of low accuracy, high memory, long runtime, and ignorance. In a two-variable polynomial, the existing algorithms show that the memory increases and the accuracy decrease. In order to improve the accuracy, the new algorithm increases the number of initial inputs and increases the efficiency of the search by introducing a direction using vectors. And, in order to solve the optimization problem, the results of the last experiment were learned to show the learning effect in the next experiment. The new algorithm found a solution in a short time under the experimental conditions of long iteration counts using a two-variable polynomial and showed high accuracy. And, it shows that the learning effect is effective in repeated experiments.

• Journal of Sensor Science and Technology
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• v.29 no.5
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• pp.342-347
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• 2020

In this study, a portable total-phosphorus (TP) monitoring system utilizing a photocatalytic-reaction-based pretreatment method is proposed, fabricated, and characterized. Commercial TP monitoring systems are only used in laboratories because of their complex monitoring procedure, bulk-size, and high-cost. In particular, pretreatment in commercial TP monitoring systems is performed at high temperatures (> 120 ℃) and pressure (> 1.1 kg cm^-2) making it difficult to minimize the scale of the systems. The proposed TP monitoring system employs a pretreatment method with a photocatalytic reaction; thus, its size can be reduced, as photocatalytic reactions occur at room temperature and atmospheric pressure. Analytes with various TP concentrations are pretreated using the proposed portable TP monitoring system and are quantitatively measured with an LED and a photodiode.

• Nutrition Research and Practice
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• v.7 no.4
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• pp.267-272
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• 2013

The anti-obesity effects of a hot water extract from wasabi (Wasabia japonica Matsum.) leaves (WLE), without its specific pungent constituents, such as allyl-isothiocyanate, were investigated in high fat-diet induced mice. C57J/BL mice were fed a high-fat diet (control group) or a high-fat diet supplemented with 5% WLE (WLE group). Physical parameters and blood profiles were determined. Gene expression associated with lipid metabolism in liver and white adipose tissue were analyzed. After 120 days of feeding, significantly lower body weight gain, liver weight and epididymal white adipose tissue weight was observed in the WLE group compared to the control group. In liver gene expression within the WLE group, PPAR${\alpha}$ was significantly enhanced and SREBP-1c was significantly suppressed. Subsequent downstream genes controlled by these regulators were significantly suppressed. In epididymal white adipose tissue of the WLE group, expression of leptin, PPAR${\gamma}$, and C/EBP${\alpha}$ were significantly suppressed and adiponectin was significantly enhanced. Acox, related to fatty acid oxidization in adipocytes, was also enhanced. Our results demonstrate that the WLE dietary supplement induces mild suppression of obesity in a high-fat diet induced mice, possibly due to suppression of lipid accumulation in liver and white adipose tissue.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7385-7393
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• 2015

This study aimed to identify the effect of brown rice-vegetable school meals program on the subjective health status, BMI and hematological parameters of high school students. This is a single group pre-post study design that includes 17 high school boys and 18 high school girls. Students were catered for lunch and dinner with brown rice and a vegetarian diet for 12 weeks at the school. The collected data on subjective health status, BMI levels and hematological parameters were measured in pre and post, and changes were compared by paired t-test. Subjective health status of the participants has improved and BMI was reduced. Blood Hct, Hb, Hct, total protein and albumin have also been reduced. Ca and triglyceride levels decreased in females. However, all levels were reduced within the normal range. These results show that brown rice-vegetable intake of high school students reduces weight and helps them prevent from acquiring cardiovascular diseases in adulthood through the reduction of serum triglyceride and in practicing healthy eating habits.

• Journal of The Korean Association For Science Education
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• v.8 no.1
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• pp.73-79
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• 1988

According to the previous studies, the science education departments in the college of education should develop better curricula to teach future secondary school teachers in a more professional way As one example of such curricula developments. one important topics of modem physics was integrated to teach the future high school physics teachers In the physics education departments. The title is "The Physics of Solar Constant Measurement The surrounding core physics for this measurements were pulled together with these important points in minds(1) clear goal of learning In the teachers college physics(2) Clear explanation of physics and visualization of important technologies for the high school students(3) these teachings should encourage for the students to use the knowledge and technologies learned through the class toward the industrial applications Korea will move toward one of the heavily industrialized countries in the world where the physics education can become key player to manufacture physics based products. Therefore developments of physics curricula which relates teachers college, high school, and industry will become more and more Important.