• Journal of Korean Elementary Science Education
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• v.43 no.2
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• pp.269-283
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• 2024

This study compared the characteristics of an experiment f or determining whether gas occupies space presented in elementary school science textbooks to examine the validity of the experiment, identify and improve problems in its presentation, and verify its effectiveness. This study interviewed third-year elementary school teachers who had experience teaching this experiment to students. Based on teachers' opinions and observations, this study identified issues with the current experiment, developed an improved experiment, and determined its effectiveness. Through this analysis, three key findings emerged. First, the study found that the original experiment on gases was presented in the same or highly similar manner in 5 of 7 textbooks (71.4%). Thus, while various textbooks have been developed with the aim of promoting diversity and creativity in scientific literature, most experiments presented in these books are identical. Second, the existing experiment was not suitable for its target audience (third-year elementary school students) and was difficult to observe directly. The interviewed teachers also deemed the validity of the experiment to be considerably low. Finally, the original experiment was improved; this improved version was determined to be highly valid, showing a statistically significant difference compared with the original experiment. The improved experiment was effective for students as it involved activities suitable for their intellectual level and was directly observable through the senses. Thus, the study analyzed and improved an existing science experiment f or elementary students, providing insights into the 2022 revised science authorized textbooks and implications for future textbook development.

• Journal of Korean Clinical Health Science
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• v.1 no.2
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• pp.21-29
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• 2013

Purpose. This study was to investigate that the adjustment of Chiropractic pelvis method have effect on body balance and improvement people who has some problem in their daily life. Methods. With 20 students of experiment group and 20 students of compare group who has cervical syndrome, experiment group has adjustment of chiropractic pelvis 2 times a week for 4 weeks, the other group who didn't take any action. Results. As a result, center of body of experiment group wasn't improved relations between left and right statistically. But the relations between front and back of center of body increased statistically, cross analysis relations between short leg and center of body increased statistically. Conclusions. As a conclusion, experiment group with the front of center of body was improved 12.88% average of center of body. Experiment group with back of center of body was improved 13.84% average of center of body. This result come to the conclusion that chiropractic pelvis adjustment help the front and back of body balance.

• Journal of the Korean Society of Clothing and Textiles
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• v.14 no.4 s.36
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• pp.281-291
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• 1990

Experiment I and II had done to develop the solar heat proof hat for field work in the summer. In the experiment I physical characteristics of several fabrics was tested to determine which one Is proper to make the solar heat proof hat. On the base of above results in the experiment II three improved solar heat proof hat was deviced and tested solar heat proof effect and compared the existing summer working hat by wearing trials in the environmental chamber. The results obtained were as follows. 1. In the view of the physical characteristics of six fabrics (Blue T/C, White poplin, Vapor transfer silver coating nylon taffeta, No vapor trans(or silver coating nylon taffeta, Aluminum coating T/C, Microporous fabric), the light color T/C and no vapor transfer silver coating nylon ta(feta is proper to make improved solar heat proof working hat. 2. Three improved hats that are made of white T/C, grey T/C and no vapor transfer silver coating nylon taffeta have more solar heat proof effect than the existing summer working hat. 3. Among the three improved hats, the improved hat that is made of no vapor transfer silver coating nylon taffeta is most effective to proof the solar heat.

• Design & Manufacturing
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• v.13 no.3
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• pp.48-52
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• 2019

As the consumer market in the mold, automation and aerospace industries grows, the demand for chemical machining using on electrochemical polishing increases. To enhance the surface roughness and gloss of the micro-needle, we have studied for an electrochemical polishing. Electrochemical polishing requires the chemical reaction of solution and material according to the electrolyte and electrode. In this study, sulfuric acid(30%), phosphoric acid(50%), and DI-water(20%)were used as the electrolytic solution, and the electrolytic solution temperature used $58^{\circ}C$. Electrochemical polishing was carried out in experimental conditions, and the micro-needle experiment was carried out from the basic experiment to obtain the experimental conditions. Experimental results show that as the voltage and current increase, the surface roughness improved and the gloss is improved. So, the best result for this experiment was obtained in condition 6, which improved micro-needle.

• Journal of the Korean Chemical Society
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• v.50 no.5
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• pp.404-414
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• 2006

this study we analyzed and improved an experiment measuring chemical reaction rates introduced in the high school science textbooks through an understanding of the phenomena observed in carrying out the experiment. For this purpose, the contents of textbooks related to the experiment were analyzed, and the problems observed in carrying out the experiment were addressed through experimental analysis. When the experiment was carried out by the method of aquatic transposition presented in textbooks, the observed volume change of H2 gas was delayed and chemical reaction rate was increased in the early stage of reaction period. To resolve these problems, an improved method for measuring the reaction rates was suggested. In the improved experiment the reaction rate was measured to be constant on time, which was interpreted in terms of the concentration of H+ and the surface area of magnesium.

• Journal of Nutrition and Health
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• v.36 no.10
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• pp.1071-1082
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• 2003

The objective of this study was to evaluate and improve the microbiological quality of HACCP application in school foodservice operations. The microbiological quality of foods and utensils were evaluated two times at each critical control point (CCP) with 3M petrifilm in five Daegu elementary schools. Two processes were evaluated: Heating process and after-heating process. The CCPs of the heating process were receiving, cooking and serving temperatures. The CCPs of the after-heating process were personal hygiene, cross contamination avoidance and serving temperature. After the first experiment, 31 employees of five schools were classroom educated, trained on-site, and pre- and post-tested on HACCP-based sanitation with the goal of improving the microbiological quality of the foodservice. Scores representing knowledge of holding, thawing, washing, food temperature, sanitizing and food-borne illness increased after education. In the heating process, internal food temperatures in the first and second experiments were higher than 74$^{\circ}C$, the holding temperature in the first experiment was less than 6$0^{\circ}C$. In the second experiment, the serving temperature improved to a satisfactory level. The microbiological quality in the second experiment improved by decreasing the time from cooking to serving. In the after-heating process, the ingredients were boiled before being cut in the first experiment. In the second experiment, ingredients were cut before being boiled, improving microbiological quality. Also in the second experiment, cooking just before serving food improved its microbiological quality through time-temperature control. These results strongly suggest it is essential to measure microbiological quality regularly and to educate employees on HACCP continuously, especially time-temperature control and cross contamination avoidance in order to improve foodservice quality.

• Proceedings of the Korean Society of Crop Science Conference
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• 2004.04a
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• pp.104-105
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• 2004

[ $\bigcirc$ ] In the phenology model of ORYZA2000, the effect of photoperiod on the developmental rate was a little ignored because most crop parameters were measured with IRRI varieties which are insensitive to photoperiod, therefore it is very difficult to apply this phenology model directly to Korean varieties which are usually sensitive to photoperiod. $\bigcirc$ After introducing PPFAC and PPSE to improve the phenology model, the precision of heading date prediction was improved but not satisfied. $\bigcirc$ In the growth simulation using data from several regions, yield tended to be overestimated under high nitrogen applicated condition. $\bigcirc$ The precision of yield was much improved by introducing nitrogen use efficiency, but still different between regions because of different soil fertility or property of irrigation water between regions

• Journal of the Korean Chemical Society
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• v.50 no.4
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• pp.328-337
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• 2006

purpose of this study was to find out problems in experiments for electrolysis of an aqueous CuCl2 solution in high school science textbooks and to suggest an improved experiment considering students' capability of experimenting and laboratory safety in high schools. For this study, the experiments for electrolysis of an aqueous CuCl2 solution presented in 11 high school science textbooks were classified by their experimental methods. After high school chemistry teachers performed the experiments as presented in the high school science textbooks, an analysis was performed on problems of the experiments, and an improved experiment was devised. According to the results of this study, in the experiments for electrolysis of an aqueous CuCl2 solution using a U type tube and a U type tube with branch, reaction velocity of the electrolysis was slow, therefore, a side reaction was generated. In the experiment using a beaker, reaction of each electrode could not be observed separately. And in the experiment using an electrolysis instrument, it was difficult to identify property of the reaction product. In the improved experiment using a reaction vessel of ㅂshape, reaction velocity of the electrolysis was fast, reaction of each electrode could be observed separately, and the side reaction decreased. From these results, it was suggested that the improved experiment would help high school students understand scientific conception regarding electrolysis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1173-1176
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• 1995

We design and analyze two type stators for brushless DC linear motors by the experiment and the computational analysis. For a U-shape stator, the maximum manetic flux density by the finite element method(FEM) is large than that by the experiment by 1.0~2.2%. The result by the FEM is so accurate that it can be applied to the geometric design for the optimization. To increase the maximum magnetic flux density, we suggest an improved stator and analyze it by the 3-D and 2-D models. The maximum magnetic flux density of the improved stator is large than that of the U-Shape stator by 2.7%. Considering the size of the improved stator and maximum magnetic flux density, we determine that the optimized thickness is 5mm for a given specification.

• Journal of East-West Nursing Research
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• v.7 no.1
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• pp.18-31
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• 2002

This study, as a basic research to manage a Chinese Medicine Health Promotion Center by way of showing an example, is a before and after experiment research for simple group to verify a difference with cholesterol, health status and perception of health in order to confirm a effectiveness of diet and regimen according to the 4th status of physical constitution. Research object was chosen of 42 persons who operate a physical constitutional dietary regimen among them after selecting professors and clinical nurses (55 persons) majoring in the science of nursing who participated in Chinese Medicine-oriented Nurse Training Course from Aug. of 2001 to Feb. of 2002 all over the country. Diagnostic tools for physical constitution was used of the questionary that is currently consisted of physical constitution grouping test in Eastern & Western Diagnose Center of K Medical Center, and rating of health status was used of the tool that standardized CMI(Cornell Medical Index) to be available for Korean, and perception measurement for health status was used of a visual analogue scale for the health status that each one perceive personally, and physiological status was measured of cholesterol in blood. Analysis for the collected data was carried out by percentage, $X^2$ test, paired t-test according to research object by using SPSS, and the results of this study are as follows. 1) There was no difference with cholesterol before or after the experiment for objects. As a result of estimation about difference with health status by areas before or after the experiment, there are more improved result in eyes, ears, digestive organs, bones and sinews organs, frequency of a disorder, habit, adaptation status, angry, healthy status than before the experiment. As a whole, after the experiment the health was more improved than before the experiment. As the result to inspect a difference of health perception between before and after experiment, after the experiment the health perception level was improved than before, however there was no meaningful differences. 2) As the result to inspect a difference of cholesterol between before and after experiment according to object's physical constitution, in the case of So-yang-in(a person with the minimum male: according to the male and female principles(the sun and the moon)) among the 4th status of physical constitution there was only meaningful difference statistically, however, after the experiment their cholesterol's value was increased. As the result to inspect the difference of health status between before and after the experiment according to physical constitution, all of Ta-um-in(a person with maximum the female), So-yang-in(with the minimum male), So-um-in(with the minimum female) had a meaningful difference before and after the experiment, which means that in all case by physical constitutional groups, after the experiment their health status was more improved than before the experiment. As the result to inspect a difference of health perception between before and after according to physical constitutions, in the case of Tae-um-in and So-um-in, average score after the experiment was risen than before the experiment so that it means that the level of health perception was improved, however, there was no meaning statistically. According to the above results, if continuous diet and regimen by each physical constitutions could be implemented, it is certain that the health could be maintained and promoted. And, what we are healthy is for oneself to feel it subjectively. However, I think that cholesterol score in blood that we can view objectively could be changed distinctly if we can implement a strict diet and regimen. Accordingly, it is necessary for a method and period of experiment to be more strict and longer. According to the above results, I would like to suggest as follows. 1) In order to understand health status by Korean's physical constitutions and to generalize it, these research will be repeated against much more objects that could be selected by proper grouping method to consider a representative. 2) It is necessary for a research to inspect health status by physical constitution by developing a health status measurement tool that has higher confidence and propriety based on physical constitutional theory.