• Advances in materials Research
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• v.6 no.2
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• pp.169-184
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• 2017

Electro-Discharge machining (EDM) is a thermal process comprising a complex metal removal mechanism. This method works by forming of a plasma channel between the tool and the workpiece electrodes leading to the melting and evaporation of the material to be removed. EDM is considered especially suitable for machining complex contours with high accuracy, as well as for materials that are not amenable to conventional removal methods. However, several phenomena can arise and adversely affect the surface integrity of EDMed workpieces. These have to be taken into account and studied in order to optimize the process. Recently, artificial neural networks (ANN) have emerged as a novel modeling technique that can provide reliable results and readily, be integrated into several technological areas. In this paper, we use an ANN, namely, the multi-layer perceptron and the back propagation network (BPNN) to predict the mean surface roughness of electro-discharge machined surfaces. The comparison of the derived results with experimental findings demonstrates the promising potential of using back propagation neural networks (BPNNs) for getting a reliable and robust approximation of the Surface Roughness of Electro-discharge Machined Components.

• Journal of Technologic Dentistry
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• v.28 no.1
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• pp.177-198
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• 2006

This study purposed to offer basic data for safety education of the dental laboratory technology after the investigation of how much the students in the dept. of dental laboratory technology are aware of the danger of each instrument, equipment or laboratory procedure that they use during laboratory and how much they demand safety education for this. The objects for this study were 423 students who were in the dept. of dental laboratory technology. In this regard, four colleges which have the dept. of dental laboratory technology were randomly selected to do a questionnaire survey. SPSS 12.0 was used to analyze the collected data. The results were as follows: As for satisfaction with their major, the respondents answered Satisfied (59.1%), Average (35.5%) and Dissatisfied (5.4%). In terms of the production process of a partial denture, they considered casting, polishing the casting body, polishing denture and burn out were most dangerous in order. As for the production process of a full denture, what they regarded as the most dangerous in order was polishing denture, deflasking and wax wash. Regarding the laboratory procedures of porcelain material, casting, trimming casting body, polishing porcelain material and burn out were the most dangerous procedures that they perceived. With regard to materials for use, alcohol, polishing, metal and wire were the most dangerous ones they thought. As for the handling characteristics of each material, small towns showed a higher demand for safety of the handling characteristics of alcohol. In terms of school year and sex, juniors and girls had higher scores in the demand for safety of the handling characteristics of acid. Regarding the handling characteristics of each equipment and instrument, all of small towns, juniors and girls showed the highest demand for safety of the handling characteristics of alcohol lamps. With regard to scores in the demand for safety of other characteristics, all of small towns, juniors and girls had the highest demand for safety of emergency treatment. Concerning the demand for safety education by the completion of safety education, in terms of each material, highest was the demand for safety of acid from the group which completed safety education. In regard to equipments and instruments, when it came to the demand for safety of the handling characteristics of casting machine, the educated group's demand for safety of acid was higher. Regarding other characteristics, the group which was not educated gained higher scores in the demand for safety of emergency treatment. 11. In all areas(materials, machines and others), small towns, girls and juniors showed higher scores in the demand for safety. Based on the above results, it was found that when students conduct the laboratory of dental technology, they would think that many materials, instruments or equipments for use are very dangerous. However, safety education was not fully given to them. Regarding the scores in the damned for safety education, the highest was 4.16 and the lowest was 3.43, which suggests that the scores were generally very high. In this regard, it is necessary to continue delivering a systematic safety education of materials, equipments or instruments used during the laboratory of dental technology. Therefore, through the analysis of each material, instruments or facility used in every laboratory and each process, safety accident types and accident risk factors should be investigated to develop educational materials for this. Moreover, it is required to open safety education as a single course of study or insert safety contents of all materials and machines into the class of dental laboratory instrument or dental materials for the purpose of a systematic and thorough safety education to prevent a safety accident during laboratory.

• Korean Journal of Health Education and Promotion
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• v.17 no.1
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• pp.171-184
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• 2000

In present paper, author proposed an effective health education strategy for local health department, which was revised from the PATCH of CDC. The author suggested that an health department should follow several steps to have an effective health promotion programs in their community. First step would be community mobilization that encourage key persons and major organizations and agencies to participate in the program. The second step is collecting demographic and vital statistics in the community or for a target audience as well as social, psychological and behavioral data. Based on the data analysis, the next step is to choose a target audience and health problem(s) for the target audience in question. The fourth step is the development of health education strategy for the target audience and the health problem. The fourth step also includes selecting a proper communication channel and educational materials as well as pre- and post-testing. The final step is implementing health education programs and evaluating the process, outcome and impact of the program. Korean Institute for Health and Social Affairs(KIHASA) has developed a model for health education programs used in local health department. KIHASA can provide technical assistance and health education materials to assist local health departments in Korea.

• Research in Community and Public Health Nursing
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• v.27 no.1
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• pp.9-20
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• 2016

Purpose: The purpose of this study was to survey the current status of mental health education and need for mental health education enhancing protective factors in the elementary schools. Methods: We surveyed 10 school health teachers and 328 fifth- and sixth-grade students using 19- and 20-item questionnaires, respectively. Results: All of the teachers and 65.2% of the students replied that they were either teaching or being taught mental health in school. Topics covered suicide, depression, school violence, and Internet addiction. All of the teachers and 84.1% of the students expressed the need for mental health education enhancing protective factors in school. Both groups replied that two sessions are enough. The teachers preferred role play and discussion as teaching methods, and audiovisual materials and computer as instructional media. The students preferred lecture and role play as teaching methods, and audiovisual materials and smartphone as instructional media. Both groups ranked self-esteem, parent-child relationship, peer relationship, and emotional regulation as the most important topics to be covered in the education. Conclusion: There is a high demand for mental health education enhancing protective factors. Therefore, it is recommended to develop educational programs enhancing protective factors by enabling formal and informal learning using smartphone.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1529-1531
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• 2008

Since the discovery over a decade ago, carbon nanotubes (CNTs) have been attracting considerable attentions both from scientists and engineers. Because of the excellent field emission properties, such as high aspect ratio, extremely small diameter, and high emission current, CNTs become a potential candidate as field emitter for field emission display (FED) and lighting (FEL) as backlight for LCD. Due to the exceptional physical properties, such as superior thermal and electrical conductivities, as well as high stiffness and strength, the CNT-based composites can be as light-weight heat-sink or thermal spreader materials used for power electronic devices, such as power LED for general illumination. The CNTs for above applications will be reviewed, and related materials and devices will be demonstrated in this paper.

• Journal of The Korean Association of Information Education
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• v.20 no.2
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• pp.161-170
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• 2016

Currently computer education has been emphasized improving thinking skill instead of practical education of applied software. There are various studies that are to teach algorithm with visualization learning materials or activitives-centered unplugged class. However, algorithm classes for elementary school have various difficulties. One of the reasons is insufficient learning materials and teaching methods. Therefore we designed a activities-centered algorithm class for elementary school students. We hope this study will contribute to the study of algorithm classes for improving kids' thinking skill.

• Hwankyungkyoyuk
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• v.20 no.3
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• pp.45-62
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• 2007

The purpose of this study was to analyze the status of environment-related teaching in elementary and secondary schools. A questionnaire survey was conducted for the study. Items in the questionnaire were developed based on the theory of environmental education and integrated education. The questionnaire was responded to 501 elementary school teachers, 273 middle school teachers, and 210 high school teachers in the city of Seoul and Kyunggi Province. The survey analysis revealed that elementary and secondary school teachers recognized 'environmental action skills' as the most important objective for school environmental education. Contrary to the teachers' expectations, it was found that there is insufficient teaching and learning materials for teaching in the domain of 'environmental action skills' and they could not confidently teach the skills in environment-related classes. For professional development of teachers in integrated environmental education, pre- and in-service programs will be developed systematically in a workshop to give teachers an opportunity to analyze teaching materials, design instruction plan, perform class trial, and evaluate the class situation for feedback. The results of this study can serve as a basic reference for improvement of environment-related subject education.

• Journal of Korean Elementary Science Education
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• v.24 no.5
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• pp.583-594
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• 2005

The purpose of this study was to investigate beginning elementary teachers' characteristics and improvement of their teaching skills in science class. The methodology of this study was a qualitative approach that included interviews, classroom observations, and teaching materials. In urban area, low beginning elementary teacher were selected. Four beginning elementary teachers were observed and recorded with VCR in their classroom at seven-times. The results showed that the beginning elementary teachers did not improve in their teaching skills in science teaching, and their characteristics of teaching skills in science were summarized as following; 1) their teaching methods were not inquiry-based science teaching, but explaining-based science teaching, 2) their main aims of the science teaching were focused on the science knowledges, 3) there were little students' science processes involved in their classes, 4) they focused on using textbook as teaching materials, 5) there were little waiting times after their questioning, and they usually used closed-questions rather than open-ended questions.

• Proceedings of The Korean Society of Health Promotion Conference
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• 1999.07a
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• pp.73-92
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• 1999

In present paper, author proposed an effective health education strategy for local health department, which was revised from the PATCH of CDC. The author suggested that an health department should follow several steps to have an effective health promotion programs in their community. First step would be community mobilization that encourage key persons and major organizations and agencies to participate in the program. The second step is collecting demographic and vital statistics in the community or for a target audience as well as social, psychological and behavioral data. Based on the data analysis, the next step is to choose a target audience and health problem(s) for the target audience in question. The fourth step is the development of health education strategy for the target audience and the health problem. The fourth step also includes selecting a proper communication channel and educational materials as well as pre- and post-testing. The final step is implementing health education programs and evaluating the process, outcome and impact of the program. Korean Institute for Health and Social Affairs(KIHASA) has developed a model for health education programs used in local health department. KIHASA can provide technical assistance and health education materials to assist local health departments in Korea.

• Journal of Korean Home Economics Education Association
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• v.9 no.2
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• pp.31-45
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• 1997

The theoretical rationale and basic materials for the improvement of the recognition on home economics teachers are suggested in this study through the close examination of the teacher’s recognition and its related variables. For this study, review of literature and questionnaire survey were performed. As the results, the following may be suggested. 1. There teachers more experienced and non-majored the home economics or those who finished professional course should be reeducated adequately for new direction of home economics education in secondary school and new curriculum. 2. The development of qualification for home economics teacher and the educational system and program for training preliminary should be try to find a solution to improve the new and positive recognition of home economics education in secondary school. 3. The institutional and environmental conditions, such as pay and welfare facilities, should be improved to satisfy home economics teacher with new view of home economics education in secondary school with their duties. 4. The systematic and concrete teaching programs for contents of improving new recognition of home economics education in secondary school, and for promoting positive self-recognition as home economics teacher, and for training the abilities of developing teaching materials and guiding practical techniques should be developed.