• Journal of Korean Elementary Science Education
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• v.28 no.1
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• pp.9-23
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• 2009

This research defined professionality of science teacher from the perspective of PCK. An teaching strategy in the in-service teacher training for the gifted education was proposed based on the definition and implemented at an in-service teacher training program for the gifted education in order to explore about the teaching strategy and suggest practical implications that could improve the program. The in-service teacher training teaching strategy proposed in this research consists of three components: 'crafting activity materials', 'conducting inquiry-based experiment', 'developing rubric for identification of giftedness'. The survey carried out for the participants of the teacher training program showed that teachers perceived the importance of the need for the rubric for gifted identification, developing activity materials for the gifted education in science, and developing the rubric of gifted identification as properties for in-service teacher training programs fur the gifted education. However, the insufficiency of time and opportunities for being fully engaged in such a program made teachers feel lack of self-confidence in developing activity materials for the gifted education in science and rubric for gifted identification. Therefore, teacher training programs reflecting real features of the gifted education should be constantly developed and provided to enhance the effectiveness of in-service teacher training programs.

• Journal of the Korean Society for Nondestructive Testing
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• v.18 no.4
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• pp.321-329
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• 1998

Structural integrity of nuclear components is important for a safe operation of nuclear power plants. Therefore, nuclear power plants require to perform reliable, periodic inservice inspections. Korea Electric Power Company(KEPCO) operates the entire Korean nuclear power plants. Since nuclear power plant safety and the associated inservice inspection(ISI) are under the plant owner's responsibility, Korea Electric Power Research Institute(KEPRI), the R&D division of KEPCO, has established the ISI NDE Total Support system(TSS) for an efficient performance of ISI tasks, and initiated both key ISI NDE technology development program and traing & qualification system development program for an independent ISI operation. This paper describes details of these programs.

• Journal of the Economic Geographical Society of Korea
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• v.24 no.2
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• pp.143-162
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• 2021

This study reviews the progress of maquiladora industry in Mexico and the development of the IMMEX program. The maquiladora program allows foreign-invested factories in Mexico to import raw materials and components duty free and to export the finished products to the U.S. It contributed to the increase in employment and population of border cities. Low wage level of Mexico induced not only standardized labor-intensive industries but also the high-tech automated industries requiring assembly process. In 2006, the Mexican government merged the maquiladora program and PITEX for Mexican export-oriented firms into a single new program, the IMMEX program, in order to promote exports more efficiently. This study presents the distributions of the IMMEX firms by industrial sector and by region. It is revealed that transport equipment sector leads the export industries in Mexico, and Tijuana and Juárez accommodate largest agglomerations of the IMMEX firms.

• Composites Research
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• v.27 no.4
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• pp.123-129
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• 2014

Ceramic matrix composites (CMCs) consist of such reinforcements as carbides, nitrides, borides and oxides, which have high melting points, low density, high modulus and high strength, for the purpose of increasing toughness. These materials are used for heat shielding systems for aerospace vehicles, high-temperature gas turbine combustion chambers, turbine blades, stator vane parts, etc. Oxide CMCs are used for the components of burner and flame holder and the high-temperature gas duct. CMCs are also applied to brake disks, which are subjected to severe thermal shock, and slide bearing parts under heavy loads. The research and development of the CMC are progressed for the strategic purpose in defense and energy industry; for instance, for aerospace applications in the U.S., and for hyper-speed aircraft, gas turbines, and atomic fissions in U.S., Japan, and Europe.

• Journal of the Korean Wood Science and Technology
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• v.34 no.4
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• pp.22-30
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• 2006

The volatile organic compound (VOC) Analyzer is a portable device to measure the four main aromatic hydrocarbon gases: toluene, ethylbenzene, xylene and styrene. With the VOC Analyzer, a semiconductor gas sensor eliminates the need for the carrier gas which is required for conventional gas chromatographs. In addition, since the semiconductor gas sensor is supersensitive to gas components, it is not necessary to use a conventional gas concentrator or other complicated equipment. Compared with other measurement methods, the VOC analyzer is useful for measuring toluene, ethylbenzene, xylene and styrene in wood-based panel because of its ease in obtaining field results and repeating the test. The VOC Analyzer primarily measures four VOC in the air. In this study, we designed a test method of VOC measurement for particle board. A specimen was sealed in 3L polyester bag, after 96hours we could measure maximum VOC emission level that is a stabilized VOC Value. For easy, fast and economic testing of TVOC emission from wood-based panel, we developed the test method with the VOC Analyzer. The VOC Analyzer is expected to gain widespread use in the manufacturing field where a quick and easy test for VOC emission from wood-based panel is required. Furthermore, the VOC Analyzer promises to become an easier, faster and more economic technique than the currently used standard methods.

• Transactions of Materials Processing
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• v.25 no.3
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• pp.161-168
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• 2016

Sheet metals are often required to be formed into three dimensional curved shapes for use as skin structures. As a result various sheet metal forming methods, such as press die forming, stretch forming, and line heating have been used over the years in industrial production lines. Although they are extensively used in industry, these methods are not suitable for small quantity batch productions. Studies have been conducted to improve or replace these methods with plausible flexible forming technologies. As a part of these studies, we developed a new and more efficient forming device named flexibly-reconfigurable roll forming (FRRF). The current study presents the process development and experimental verification for the applicability of this device. To improve the efficiency of the FRRF apparatus, several hardware components were invented and a suitable operating program was developed using MFC of visual C++. The ways to make the FRRF apparatus fully functional are also described. Sheet metal was formed into three dimensional shapes using the FRRF apparatus and the final products are presented as evidence for the applicability of the developed device.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.11
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• pp.100-107
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• 2021

The use of new and renewable energy is essential to solve the problem of increasing fossil fuel use due to industrial development. The paradigm of the automobile industry has changed due to the strengthening of environmental regulations in developed countries, and the development of eco-friendly cars is underway. Fuel cell electric vehicles (FCEVs), which use hydrogen as fuel, require strict standards for fuel-related components. In particular, check valves for FCEV control high-pressure hydrogen and thus, must be sufficiently strong for the challenging environment caused by high-pressure hydrogen. Therefore, this study used DEFORM 3D, a regular finite element analysis program, to check the moldability of check valves for FCEV, design the process, verify reliability through single streamline analysis, tensile tests, and ANSYS simulations, and identify suitable materials for the high-pressure hydrogen environment.

• 연구논문집
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• s.30
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• pp.101-110
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• 2000

Weft insertion mechanism is for completing the structure of yarn and weft yarn and its driving method is screw type. In the high speed rapier loom, weft yarn is thrown by insert rapier and carrier rapier into the shed which make divide two parts of upper part ant lower part for warp yarn. It is possible for this mechannism to reduce the size of rapier and wheel, and directly connected to the main shaft without gear belt. Therefore, exact rapier motion through realization of arbitrary acceleration diagram requested rapier and optimal design for high speedization and operating rate increasing are necessary. In this study, with a view to exact system analysis for understanding of overall trace and high speedization of rapier loom through computer simulation. we report not only deduction of displacement, velocity, and acceleration components of rapier for analysis theory establishment, of weft insertion mechanism and exact motion induction according to screw rotation, but also development of simulation program for realization these on the monitor.

• Research in Community and Public Health Nursing
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• v.15 no.3
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• pp.385-396
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• 2004

Purpose: Hypertension has been a major cause of death in Korea since the 1970s, and has resulted in being a significant economic burden to the finances of national health care. The Ministry of Health and Welfare made several efforts. but hypertension control programs in Korea are still non standardized and ineffective. We wanted to investigate the current hypertension control program in public health centers systematically and suggest the direction for future programs. Method: The design of this study is a cross sectional investigation. From September to October in 2002, we sent a set of questionnaires to all PHCs, and 179 centers responded (response rate = 74.0%). The instrument was developed based on components of National health systems. Results: 1) Resources: The department responsible for hypertension control programs is the Department of Health Promotion. Health Education Center, Community Health Center, Citizen's Health Center, etc. The chief personnel of those departments are nurses. but 27.4% of PHCs have no full time nurse for hypertension management programs. PHCs had a lot of teaching materials (nine types per a PHC) and most of the recommended contents were included. But, periodical evaluation and revision were not being made, 2) Management: Nurses' (13.03 9.46 in 23 score) actions for hypertension control were not qualitative, but regular training and evaluation were seldom carried out. Need assessment (25.9%) and evaluation (about 10-20%) for the hypertension control program were indicated as low. 3) Programs: Programs focused on individuals rather than community or public, and 2nd prevention rather than 1st, 3rd prevention. Conclusion: The Ministry of Health and Welfare has to construct the infrastructure for hypertension control programs. Related scholars and committees should develop and declare standardized manuals for hypertension control and the management system, as well.

• Transactions of Materials Processing
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• v.28 no.6
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• pp.321-327
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• 2019

In this study, a hot and cold forging process was investigated to produce a complex-shaped hub of dual clutch transmission with low material loss and high productivity. The process was designed by the commercial finite element (FE) analysis program, DEFORM-2D (hot forging) and 3D (cold forging). And, the material flow and ductile fracture characteristics were studied to check the surface crack initiation of the specimen. The simulation results indicated that the proposed process could manufacture the complex-shaped hub with no surface crack and high-efficiency compared to the conventional machining process. For verification the numerical results, the hub of the SCM440 was fabricated by the proposed process and the mechanical properties and microstructure evolution were studied. It was demonstrated that the suggested hot and cold forging process might be useful in producing the key components of the automobile industry as a high-efficiency and environmentally friendly process.