• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.10
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• pp.1457-1465
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• 2009

This study was conducted to analyze the food safety management practices and to provide data that could be used to improve food safety management at kindergarten foodservice establishments in Daegu and Gyeongbuk province. Microbiological hazard analysis was conducted from May to July, 2008 at the four foodservice establishments. A total (20 items) of foodservice facilities, cooking utensils, and equipment were tested about total plate counts, coliforms, E. coli, Staphylococcus aureus, Salmonella spp., and Listeria monocytogenes. The microbiological detected levels were higher than the critical limits for prepreparing and cooking knives, chopping boards, working tables (both prepreparing and cooking), refrigerator (inside wall), bart, basket, and tray. E. coli, Salmonella spp., and Listeria monocytogens were not detected in any samples. However, Staphylococcus aureus were detected in rubber gloves for cooking and trench in the bottom at one foodservice establishment. In conclusion, these results suggest that a prerequisite programs guideline should be provided to improve the food safety levels at kindergarten foodservice establishments and the foodservice manager must maintain proper food safety technique for foodservice facilities, cooking utensils, and equipment at kindergarten foodservice establishments to prevent cross-contamination and spread of foodborne pathogens.

• The Journal of the Korea Contents Association
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• v.17 no.7
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• pp.113-123
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• 2017

This research is designed to review the systems thinking and STEAM theory while ascertaining the effects of the classroom application of the STEAM programs based on systems thinking appropriate for studying climate change. The systems thinking based STEAM program has been developed by researchers and experts, who had participated in expert meetings in a continued manner. The program was applied to science classes over the course of eight weeks. Therefore, the application effects of the systems thinking based STEAM program were analyzed in students' systems thinking, STEAM semantics survey, and students' academic achievement. The findings are as follows. First, the test group has shown a statistically meaningful difference in the systems thinking analysis compared to the control group in the four subcategories of 'Systems Analysis', 'Personal Mastery', 'Shared Vision' and 'Team Learning' except for 'Mental Model'. Second, in the pre- and post-knowledge tests, the independent sample t-test results in the areas of science, technology, engineering, art and mathematics show statistically meaningful differences compared to the control group. Third, in the academic performance test regarding climate change, the test group displayed higher achievement than the control group. In conclusion, the system-based STEAM program is considered appropriate to enhance amalgamative thinking skills based on systems thinking. In addition, the program is expected to improve creative thinking and problem-solving abilities by offering new ideas based on climate change science.

• Journal of The Korean Association For Science Education
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• v.29 no.1
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• pp.43-53
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• 2009

The teacher's role in education is important. Science education majors must be able to solve problems effectively and pertinently when facing new ones in various situations and complicated human relations in order to become successful science teacher. The purpose of this research is to develop a test that measures the Practical Ability of pre-service science teachers and to apply this to them. The Practical Efficacy Scale for Science Education Majors was also developed in order to be used for validation. In this research, Practical Ability of Science Education Majors consisted of four sub-domains: subject education, business administration, relations and self-development. The result of the correlations between the scores of four sub-domains and the composite score of Practical Ability Test for Preservice Science Teacher(PATPST) is relevant. Subject education and administration business is the highest correlation with PATPSP score specially, and correlation between two areas appeared high. The result of applying PATPSP scores differed according to the grade of science education majors, but not according to their majors. This study's limitation is that the subjects consisted only of female students. However, PATPSP could be a new method that will help science education majors be successful science teachers.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.1
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• pp.69-84
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• 2023

Despite the continuous installation and regular inspection of waste treatment facilities, complaints about excessive incineration and illegal dumping stench continue to occur at on-site treatment facilities. In addition, field surveys were conducted on the waste treatment facilities currently in operation (6 type) to understand the waste treatment process for each field, to grasp the main operating factors applied to the inspection. In addition, we calculated the material·energy balance for each main process and confirmed the proper operation of the waste disposal facility. As a result of the site survey, in the case of heat treatment facilities such as incineration, cement kilns, and incineration heat recovery facilities, the main factors are maintenance of the temperature of the incinerator required for incineration and treatment of the generated air pollutants, and in the case of landfill facilities Retaining wall stability, closed landfill leachate and emission control emerged as major factors. In the case of sterilization and crushing facilities, the most important factor is whether or not sterilization is possible (apobacterium inspection).In the case of food distribution waste treatment facilities, retention time and odor control during fermentation (digestion, decomposed) are major factors. Calculation results of material balance and energy resin for each waste treatment facility In the case of incineration facilities, it was confirmed that the amount of flooring materials generated is about 14 % and the amount of scattering materials is about 3 % of the amount of waste input, and that the facility is being operated properly. In addition, among foodwaste facilities, in the case of an anaerobic digestion facility, the amount of biogas generated relative to the amount of inflow is about 17 %, and the biogas conversion efficiency is about 81 %, in the case of composting facility, about 11 % composting of the inflow waste was produced, and it was comfirmend that all were properly operated. As a result, in order to improve the inspection method for waste treatment facilities, it is necessary not only to accumulate quantitative standards for detailed inspection methods, but also to collect operational data for one year at the time of regular inspections of each facility, Grasping the flow and judging whether or not the treatment facility is properly operated. It is then determined that the operation and management efficiency of the treatment facility will increase.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.2
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• pp.158-162
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• 2004

Reliability of welded structures in power plant facilities is very important, and their reliability evaluation requires exact materials properties. But, the conventional PQR (Procedure Qualification Record) can hardly reflect the real material properties in the field because the test is only done on specimens with simulated welding. Therefore, a continuous indentation technique is proposed in this study for simple and non-destructive testing of in-field structures. This test measures the indentation load-depth curve during indentation and analyzes the mechanical properties such as the yield strength, tensile strength and work hardening index. This technique has been applied to evaluate the tensile properties of the weldment in the main steam pipe and hot reheater pipe in power plants under construction and in operation.

• Communications of Mathematical Education
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• v.27 no.3
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• pp.321-339
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• 2013

This study is basic research about actualizing mathematical teaching and learning based on storytelling that is raised for reforming school mathematics education. We have developed mathematics textbook model for 2nd grade in middle school based on storytelling. It was applied in the middle school classroom and the results were analyzed. In order to develop the mathematics textbook model, the procedures and methods of development were extracted from the literature. And mathematics textbook model was developed in accordance with the process and methods. To apply it in school 20 hours of instruction were carried out. For the analysis of the results, we conducted a questionnaire survey, the teachers' interview, the affective test and math anxiety test. Through the results of this study, we will be able to check the possibility of storytelling in mathematics class. And it will be also the foundation of mathematics teaching and learning based on storytelling in middle school.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.3
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• pp.246-253
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• 2002

This paper describes the development and the field application of the ultrasonic gas flowmeter for accurate measurement of the volumetric flow rate of gases in a harsh environmental conditions in iron & steel making company. This ultrasonic flowmeter is especially suited for measuring LDG, COG, BFG gases produced in iron & steel making process. This is a transit time type ultrasonic flowmeter. We have developed the transmitting & receiving algorithm of ultrasonic wave and the ultrasonic signal processing algorithm to develope a transit time type ultrasonic flowmeter. We have evaluated the performance of ultrasonic flowmeter by the calibration system with Venturi type standard flowmeter. We has confirmed its reliability by extensive field tests for a year in POSCO, iron & steel making company. Now we have developed the commercial model of ultrasonic flowmeter and applied to the POSCO gas line.

• Journal of the Korean Society for Nondestructive Testing
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• v.17 no.4
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• pp.248-261
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• 1997

Ultrasonic pattern recognition is the most effective approach to the problem of discriminating types of flaws in weldments based on ultrasonic flaw signals. In spite of significant progress in the research on this methodology, it has not been widely used in many practical ultrasonic inspections of weldments in industry. Hence, for the convenient application of this approach in many practical situations, we develop an intelligent ultrasonic signature classification software which can discriminate types of flaws in weldments based on their ultrasonic signals using various tools in artificial intelligence such as neural networks. This software shows the excellent performance in an experimental problem where flaws in weldments are classified into two categories of cracks and non-cracks. This performance demonstrates the high possibility of this software as a practical tool for ultrasonic flaw classification in weldments.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.1
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• pp.40-46
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• 2011

In the field application of the conventional acoustic nonlinear technique using through transmission of bulk waves to evaluate the contact acoustic nonlinearity(CAN) in solid-solid contact interfaces like as in the closed crack, it has difficulty to access inner position for attaching the pulsing or receiving transducer. In the present study, a new reflection technique has been suggested to measure the acoustic nonlinearity in solid-solid contact interfaces, which uses both of pulsing and receiving transducers on the same side of target and so that it will be very useful for the field application. For this, based on the linear and the nonlinear contact stiffness estimated by the power-model of the contacting pressure, the nonlinear parameter of the reflected ultrasonic wave at the interfaces has been theoretically calculated. Experimental results in contact interfaces of A1606l-T6 alloy specimens with loading pressure showed good agreement with the theoretical predictions, which proves the validity of the suggested reflection mode technique.

• Journal of the Korean Society for Railway
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• v.13 no.4
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• pp.447-454
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• 2010

The defects of rail head induced by fatigue and deterioration are mainly classified by two types ; one occurred on the surface of rail head the another occurred on the inner rail head. This study performed the surface irregularity measurement of rail head according to the passing tonnage in the urban railway. Also, we carried out microscopic structure test, chemical component test and micro-hardness test for the specimen which is the used rail on metro line by accumulated passing tonnage. As a result of this study, for new rail, it should be performed initial grinding in order to remove 0.3mm of de-carbonized layer. The preventive-cyclic grinding for preventing RCF defects is proposed two options : grinding by the whole line and grinding by specified sections.