• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2004년도 추계학술발표회 발표논문집
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• pp.1047-1048
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• 2004

Simulation Coated layers of a nuclear fuel particle were evaluated by field emission scanning electron microscopy and nano-indentation method to give basic data to estimate 'Amoeba effect' and give an optimum fabrication condition and high quality control. Coated layers on the fuel kernel are in the order of buffer pyrolytic carbon, inner pyrolytic carbon, silicon carbide and outer pyrolytic carbon layers, which average thicknesses are 95, 25, 30 and 28 ${\mu}m$, respectively. Their densities and hardnesses are 1.08, 1.15, 3.18, 1.82 $g/cm^3$ and 0.522, 0.874, 9.641, and 2.726 GPa, respectively. Comparing theoretical density of pyrolytic carbon of 2.22 $g/cm^3$, the relative amount of porosity in each layer is about 52% for buffer, 48% for inner PyC and 18% for outer PyC.

• Ocean and Polar Research
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• 제33권2호
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• pp.171-183
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• 2011

Despite technological developments and application advances of Acoustic Doppler Current Profilers (ADCPs), no standard procedure has been adopted or accepted for calibration of ADCPs. Limitations of existing facilities for calibrating ADCPs, the complexity of ADCP instruments, and rapid changes in ADCP technology are some of the reasons why a standard procedure has not been adopted. However, there is increasing realization of the need for effective Quality Assurance (QA) and as part of that the importance of standardized calibration. In this study, the significance of calibration and QA plans for ADCPs is discussed and the calibration facilities for ADCPs at home and abroad are reported. Furthermore, the method for calibrating ADCPs using a towed car and its limitations are discussed. This study contributes to discussions surrounding the establishment of standard procedures for calibrating ADCPs and QA plans, and the construction of calibration facilities in the future.

• 한국정보시스템학회지:정보시스템연구
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• 제19권4호
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• pp.87-109
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• 2010

The ubiquitous computing & technology is to make passive IT machinery as the smart-object to solve the problems of information management. These ubiquitous devices can be a concierge of humans lives. In addition, the ubiquitous computing & technology added with Pro-Active processing technology is the intellectual automatic process capacity that probably enhance quality of human's life. Although the social influencing power of ubiquitous computing technology is so critical, research on the social impact of ubiquitous has been studied insufficiently. And, we also need the countermeasures to protect the societies from the side effect of the ubiquitous computing technology. The purpose of this research is to minimize the loss which comes from the new ubiquitous society, by presenting the technological and systematic alternatives and by researching the various side effects. This research suggests the proper alternatives by reviewing and by researching the adverse effects of the ubiquitous computing technology.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.23-23
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• 2003

GaN-related semiconductors are of great technological importance for the fabrication of optoelectronic devices, such as blue and ultra violet light emitting diodes (LEDs), laser diodes, and photo-detectors. One of the most important applications of GaN-based LEDs is solid-state lighting, which could replace incandescent bulbs and ultimately fluorescent lamps. For solid-state lighting applications, the achievement of high extraction efficiency in LED structures is essential. For flip-chip LEDs (FCLEDS), the formation of low resistance and high reflective p-GaN contact is crucial. So far, a wide variety of different methods have been employed to improve the ohmic properties of p-type contacts to GaN. For example, surface treatments using different chemical solutions have been successfully used to produce high-quality ohmic contacts, Metallization schemes, such as Ta/Ti contacts to p-GaN, were also investigated. For these contacts, the removal of hydrogen atoms from the Mg atoms doped n the GaN was argued to be responsible for low contact resistances.

• 한국유기농업학회:학술대회논문집
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• 한국유기농업학회 2001년도 심포지엄
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• pp.248-265
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• 2001

Recently, agriculture in Korea is seriously depressed by economic globalization and trade liberalization because of low competitive power. Organic farming, which is favorable for small scale agriculture, is expected to be one of alternatives to boost agricultural activities in Korea. Organic agriculture requires systemic developments of new technologies considering the complex biological interaction within the system in connection with high quality and safety standard. The National Institute of Agricultural Science & Technology(NIAST) has been worked on the series of organic farming technologies, including bio-pesticides, pheromone, natural enemies as well as the testings of materials used in organic farming. NIAST will concentrate on the technological development for compromising to the conflict between commodity-oriented and ecological harmony. Research on systemic land and water use, management of plant nutrition, pest and disease control, post-harvest would also be important targets. Integrated efforts among researchers, professors, administrators, farmers, private sectors, and extension workers are substantial for fast technology development and its dissemination. Development and use of these technologies will homely enlighten the Korean organic farming although it may require quite a time and endeavor.

• 경영과학
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• 제32권4호
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• pp.175-192
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• 2015

Due to the emergence of open innovation driven by development of network service technologies and convergence in ICT service industry, It is necessary for ICT service firms to examine their capabilities for open innovation. The purpose of this paper is to empirically examine determinants affecting open innovation in Korean ICT service industry. In order to analyze, this paper uses logistic and multiple regression models based on survey data of Korean ICT service firms. Estimation results show that external network for collaboration is positive on the technological innovation activity regardless of the innovation type. Specifically, user networks are significant in all types of technology innovation, revealing that it is important to innovation activities of the ICT service firms.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 The 8th Asian Symposium on Precision Forging ASPF
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• pp.10-17
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• 2003

The amount of production orders from Japanese car and construction machine industries have slightly increased in 2002, but the costs of the forged parts have decreased due to severe competitions with the other Asian countries. Most of the forging industries and some universities are making more efforts for technological researches and developments to meet the demand for higher accuracy and higher quality products, shortening of delivery time, and development of forged parts for new industrial fields. Some helical gears of which surfaces can be net-shaped have been started for commercial base production to be shipped to car industries. Some non-graphite lubricants for hot forging and some conversion coating free lubricants for cold forging have been developed to improve some environmental problems.

• 전자공학회논문지A
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• 제29A권10호
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• pp.8-16
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• 1992

Despite recent advances in electrical switch architectures, the practical switch performance is limited by both the technological and physical constraints of electrical device and wiring. Though an optical switch can have good features, optical devices are of poor quality. Therefore, we propose and study the switching architecture based on free-space optical interconnections and electrical logic devices. And an exchanging method using packets with a parallel form is introduced to solves the blocking problem of the switch that resulted from switching packets with a serial form. The free-space optical interconnections overcome the defects of electrical switch, such as, the complex connections of the wires. The proposed and demonstrated switch is nonblocking, simple and high performable. Other attractive features of the proposed switch include the guarantee of first-in first-out packet sequence. In this thesis, we also discuss the performance of proposed switch and show the experimental results of the 4$\times$4 switch.

• 대한치과의사협회지
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• 제54권7호
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• pp.542-550
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• 2016

Recent technological advance have greatly expanded the application of invisible orthodontic treatment using clear thermoplastic materials. However, the final outcomes using clear aligner system do not achieve the level of final goal frequently, which results in case refinement, midcourse correction, or fixed orthodontic treatment. Therefore, mechanical properties of thermoplastic materials should be considered to improve the quality of outcomes. The purposes of this special article were to evaluate the force and stress depending on the materials, deflection and thickness of thermoplastic materials and to evaluate the mechanical properties of thermoplastic materials after repeated loading. Thickness and amount of deflection rather than products and materials showed the largest effect on force and stress. In all products, at least 159 gf of force was required for more than 1.0 mm deflection or when materials with 1.0 mm thickness were deflected. Orthodontic forces delivered by thermoplastic materials depend on the materials, thickness, amount of activation, and intra-oral condition. Proper thickness of thermoplastic materials and deflection level of tooth movement should be decided for the efficient and physiologic tooth movement.

• 한국과학교육학회지
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• 제5권2호
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• pp.99-112
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• 1985

As long as there is education, there will be teacher education. This statement implies that science education is the first step for the improvement of science education of the secondary schools. And science education must reflect an everchanging reality of scientific, technological, and social changes. However there have been problems in the curiculum and its operation for science teacher education. Therefore this research has its objectives to: 1) investigate the current goals of science education in the Korean secondary schools. 2) analyze the quality' and Knowledge required for science teacher to achieve the goals. 3) investigate the status and problems of science teacher education in korea and foreign countries. 4) develop a model for curriculum and its operation for desirable science teacher education. As a result of the study, a model for curriculum is described and the summary of the results of the study and suggestions for operation of the model are followed.