• Journal of Oral Medicine and Pain
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• v.23 no.3
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• pp.241-247
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• 1998

Salivary research is at a critical crossroads regarding the clinical application of the basic knowledge. The purpose of this article is to introduce the current progress on salivary research to Korean dental scientists. The accumulated results based on advance technologies such as protein chemistry, molecular biology, and structural biology have showed that salivary macromolecules need structural requirements for proper function. Currently, several concepts or principles, which can be applied to salivary macromolecules, have been suggested. These include the role of molecules' conformation on biological activity, their multifunctional nature, their redundancy of function, their amphifunctional properties, and the potential importance of complexing between molecules. These concepts and the information available will help the development of saliva substitutes, the design of drug carriers and chimera molecules with enhanced function and the development of gene therapy protocols. These approaches will alleviate or restore lost salivary function and can be used to treat various kinds of oral and systemic diseases.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.101-103
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• 2000

Research for the synthesis of high-temperature polymers by the Photochemical method has been carrying out. The use of cheap and available compounds (viz. benzene, its alkyl, aryl and halogen substitutes, furan and maleic anhydride) subject to ultra violet irradiation resulted in a single stage quantitative yield of about 40 new polymers: polyimide films, enamel insulation, molding materials. At present experimental ＆ industrial lots of wire have been produced. Polymer insulation possesses temperature exploitation range (from -l00$^{\circ}C$ to +300$^{\circ}C$) without significant changing of properties. As a result, new polyimide lacquers for production of a wide number of technical articles, such as polyimide films, fibers, enamel-wires, press-materials have been synthesized. An application field of the polyimides in membrane technology, printing plate and optic electronics manufactures has been outlined.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.10
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• pp.791-797
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• 2012

Mineral insulating oils are an important insulating materials in oil-filled transformer. However, the mineral oil is the cause of the environmental problem. The vegetable oils are substitutes for mineral oil because of its biodegradability characteristic. As large size and high rating of the transformer increases, the losses increase at a faster rate. So insulating oil is forced circulation in the oil-filled transformer by using oil pumps. The flow electrification occurs when insulating oil was forced to be circulated. To check the flow electrification, had conducted experiments varying factors. As a result, the streaming electrification could see the changes according to flow velocity, oil temperature and insulation materials.

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.271-273
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• 2000

This paper presents the dynamic characteristics Linear DC Motor(LDM) using 3 Dimensional Equivalent Magnetic Circuit Network Method(3-D EMCN) by voltage driven. The movement of mover substitutes for the movement of magnetization in permanent magnet expressed by Fourier series. The Dynamic characteristics are carried out from coupling the electrical circuit equation and mechanical kinetic equation.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.221-222
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• 1996

In order to prepare the porous hydroxyapatite (HA) ceramics with different porosity, interconnectivity, mechanical properties, surface chemistry and tissue response, several methods have been developed. Of the different forms of Porous HA ceramics which were prepared by various methods, only the coralline HA has undergone major clinical applications in orthopaedic, maxillofacial and ophthalmic surgery. In this study, totally synthetic macroporous HA ceramics with various pore size distribution were prepared. It is shown that the new reticulate HA ceramics, comprised of interconnected voids surmunded by a web of ceramic, have a morphology which mimics that of human trabecular bone.

• Journal of the Korean Society of Safety
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• v.23 no.6
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• pp.95-99
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• 2008

Halon was known as a cause of the ozone layer destruction. In 1987, it was designated as one of the ozone-layer-destroying materials in the Montreal Protocol. Therefore substitutes of Halon agent has been developed including inert gas extinguish system, which is one of the most widely used fire extinguishing system. This study intended to increase the efficiency of inert gas extinguishing agent by using inert gas additives. As IG-541 shows high extinguishing power, the experiment was performed to measure the effects of gaseous additives to it. Cup-burner fire extinguishing apparatus was used with n-Heptane fuel. Among many of pure inert gaseous agents, Helium showed the most excellent extinguishing power. When Helium was added to IG-541, fire extinguishing power was increased and the concentration of oxygen in chimney also risen. By adding Helium to IG-541, the effectiveness of inert gas fire extinguishing system is able to be increased.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.4
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• pp.390-394
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• 2010

This paper describes a study on developing an insert and detect system of digital watermark to the MPEG-2 coder and decoder. Digital watermark inserting system substitutes a coefficient among the DCT coefficients for new one. This replacement performs in MPEG-2 PS format. Watermark detecting system analyzes the input data stream of MPEG-2 and detect the probability of occurrence of a specific code or watermarking code. Our inserting system had very high invisibility and the PSNR of the results was 130 dB around. And our detection rate of watermark was over 99% in digital format and over 85% in analog captured format according to the quality of contents.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.3B
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• pp.464-471
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• 2000

The number of quantization bits of the input signals $X_k$,$Y_k$ need to be optimally determined through the trade-off between the H/W complexity and the BER performance in Turbo codes applications. Also, an effective means to incorporate a channel reliability $L_c$ in the Log-MAP-based Turbo decoding is highly required. because it has a major effect on both the complexity and the performance. In this paper, a novel bit-shifting approach that substitutes for the multiplying is proposed so as to effectively incorporate. $L_c$ in Turbo decoding. The optimal number of quantization bits of $X_k$,$Y_k$ is investigated through Monte-Carlo simulations assuming that bit-shifting approach is adopted. In addition. The effects of an incorrect estimation of noise variance on the performance of Turbo codes is investigated. There is a confined range in which the effects of an incorrect estimation can be ignored.

• Knowledge Management Research
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• v.11 no.4
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• pp.79-89
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• 2010

Companies always competing with rivals in global market ought to cope with various kinds of crises coming from substitutes, new technologies, changing consumer tastes, and government regulations, etc. In this sense, it is highly required that companies should always remain well-prepared for crisis management. Nevertheless, many companies still lack detailed and well-guided strategies about how to handle crisis. This study proposes a case study to propose an effective crisis management by using knowledge management. Cases analyzed by this study are concerned with Daewoo International Corporation (http://www.daewoo.com) and Decoline (http://www.decoline.co.kr) where crises have been successfully overcome by using effective knowledge management strategies, and company performance reached sustainable level.

• Earthquakes and Structures
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• v.12 no.4
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• pp.449-455
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• 2017

Using X-braced frames in steel structures is a current procedure to achieve good strength against lateral loads. Study on mid-connections of X-braces and their effects on frame behavior is a subject whose importance has been more or less disregarded by researchers. Experimentally inspecting models involves considerable expense and time; however, computer models can be more suitable substitutes. In this research, a numerical model of X-braced frame has been analyzed using finite element software. The results of pushover analysis of this frame are compared with those of the experimental test. With the help of computer model, the effects of different mid-connection details on ductility and lateral strength of the frame are inspected. Also performances of bolted and welded connections are compared. Taking into account ductility and strength, this study suggests details of a decent pattern for the mid-connection.