• Journal of the Korean Society of Industry Convergence
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• v.9 no.4
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• pp.277-283
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• 2006

As the products such as HDD, Notebook, PDA, and Mobile Phone become smaller and thinner, the radius of threads as well as holes for assembling those products become smaller, even down to 1mm. To produce such small holes and thread efficiently, multi tapping is highly necessitated. However the multi tapping characteristics is not well known because its complicated cutting mechanism and thus the quality of the produced holes and threads is not well studied yet. In this paper, experiments have been conducted for small-radius threads using M2 and M2.6 and M3 cold forming tap to investigate multi tapping process using several useful signal such as torque and Z-axis encoder pulse. The surface and profile of the machined threads have been magnified and observed through a SEM.

• Journal of Nutrition and Health
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• v.37 no.6
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• pp.493-501
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• 2004

The purpose of this study was to evaluate weight control program provided by university health care center for female college students. The program was 8-week long and composed of diet, exercise, and behavioral modification. Evaluation was made on the completion of 8-week program and a follow-up survey was done at 3-24 months after the end of program by telephone or bye-mail. Total of 76 women completed the 8-week program and 51 for follow-up survey. On the completion of 8-week program, significant decreases in body weight, BMI, body fat (kg), ％ body fat, and WHR were resulted, however, no change in muscle mass was found. Even the subjects without weight change showed significant reduction in body fat (kg) and ％ body fat. Total food intake was decreased resulting in reduced intakes of most nutrients. Meal distribution of energy was changed; ％energy from snack decreased from 22％ to 14％, and proportion for breakfast increased. Blood values of hemoglobin, hematocrit, total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglyceride were within normal range, and no changes were observed by this program. The follow-up survey revealed that 88.3％ of the subjects continued to lose weight after completion of the program, while only 7.8％ gained weight. And 78.4％ of the subjects considered the program effective. In conclusion, the weight reducing regime with education is effective for long lasting weight control and health conscious behavior for female college student. Since the subjects reduced the size of meal, instead of cutting only calories down, food selection to meet all the nutrient requirements except energy should be emphasized.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.140-145
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• 2000

The Exchange-cooperation of the Korean peninsula on the Internet contains the possibility that forms the basic of the South-North relationship to meet the Age of information. the Exchange-cooperation on the Internet will make a contributes to the frame of mutual cooperation in the two nations as solving the inconvenience, which might follow the direct contact between them, and cutting down on expenses. Focusing on the Internet, especially Software and Communication service in the Information and Communication sector. This paper presents the Establishment scheme of Cyber network for obtaining mutual cooperation on the Korean peninsula.

• Korean Journal of Medicinal Crop Science
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• v.10 no.4
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• pp.237-242
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• 2002

It was found that the purified extract from A. gigas Nakai (polysaccharide, M.W., 25 kD) controled differentiating human ES cells. Its optimal supplementation concentration was decided as 0.8 $({\mu}g/ml)$ to efficiently control the differentiation. It also enhanced the cell growth, compared to the control. However, most widely used and commercially available differentiating agent, Leukemia Inhibitory Factor (LIF) negatively affected on the cell growth even though it controls the differentiation of ES cells, down to 40-50 % based on morphological observation and telomerase activity. It was presumed that the extract first affected on cell membrane and resulted in controlling signal system, then amplify gene expression of telomere, which enhanced the telomerase activity up to three times compared to the control. LIF only increased the enzyme activity up to two times. It was confirmed that the extract from A. gigas Nakai could be used for substituting currently used differentiation controlling agent, LIF from animal resources as a cheap plant resource and not affecting the cell growth. It can broaden the application of the plants not only to functional foods and their substitutes but also to fine chemicals and most cutting-edge biopharmaceutical medicine.

• Journal of Environmental Science International
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• v.15 no.1
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• pp.95-100
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• 2006

Heat transfer and flow characteristics in a pipe in which the rotating cutting tool for boring a underground pipe without digging were considered in this study. The amount of heat generation due to the friction between the rotating cutter and pipe wall, mixing (low of air and water injected to cool down are the two important factors to design the boring machine Computational fluid dynamics analysis using the Eulerian mixture model and the standard $\kappa-\varepsilon$ turbulence model was used to analyze the complex phenomena in a pipe during the process. Results show that pipe wall temperature decreased with increasing the cooling water inlet velocity. it is also shown that pipe wail temperature was lowered when the cutter rotation speed was increased until 600 rpm. There was no further cooling effect over 600 rpm.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1865-1868
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• 2003

This paper provides a new method for hybrid machining, particularly suited to micro fabrication applications such as micro point, micro line, micro structure, micro partition and so on. Developed micro fabrication process by electrical discharge machining (EDM) and electrical discharge deposition (EDD) with metal powder (Ti, Fe) has been studied to build TiC or FeC structure. Titanium powder or iron powder is supplied from working fluid (kerosene or de-ionized water with powder) and adheres on a workpiece by the heat and electric power caused by the electrical discharge. The use of a tool electrode is expected to keep powder concentration high in the gap between a workpiece and a tool electrode and to accrete powder material on the workpiece. The deposition is tried under various electrical conditions (workpiece. tool electrode, working fluid, discharge current, voltage and powder etc.). On the other hand. using electrical discharge machining (EDM) with the same tool electrode, it can be used as a removal process (cutting) by electro erosion at the same time. Therefore. this new method can do a hybrid machining to build up and down a structure with the workpiece.

• Geomechanics and Engineering
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• v.8 no.5
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• pp.675-685
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• 2015

Weathering is the breaking/cutting down process of rocks due to physical and chemical processes in natural as well as artificial environment including $CO_2$ injection for storage in the sediment, or natural resource recovery process. This study suggests an alternative method to estimate the degree of weathering for granites. A series of laboratory and field experiments are performed to measure electrical resistivities on various rock samples experienced different degrees of weathering and their residual soils under different saturation conditions. It is found that the normalized electrical resistivity increases with a decrease in water absorption and the saturation. Simple boundaries are suggested to identify the weathering degree of granites, based on limited data. Field test results for three sites confirm that the suggested method could be estimated well the degree of weathering of granites compared with the other methods suggested previously. Although further research is required, this study suggests that an electrical resistivity could be an effective approach to estimate the degree of weathering of granites compared with the other methods suggested previously.

• Journal of Korean Society of Water and Wastewater
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• v.14 no.1
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• pp.108-116
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• 2000

Chlorine is widely used as a disinfectant in drinking-water systems throughout the world. Chlorine residual was used as an indicator for prediction of water quality in water distribution systems. The variation of chlorine residual in drinking water distribution systems of Suwon city was simulated using EPANET. EPANET is a computerized simulation model which predicts the dynamic hydraulic and water quality behavior within a water distribution system operating over an extended time period. Sampling and analysis were performed to calibrated the computer model in 1999 (Aug. Summer). Water quality variables used in simulations are temperature, roughness coefficient, pipe diameter, pipe length, water demand, velocity and so on. Extended water residence time affected water quality due to the extended reaction time in some areas. All area showed the higher concentration of chlorine residual than 0.2mg/l(standard). So it can be concluded that any area in Suwon city is not in biological regrowth problem. Rechlorination turned out to be an useful method for uniform concentration of free chlorine residual in distribution system. The cost of disinfectant could be saved remarkably by cutting down the initial chlorine concentration to the level which guarantees minimum concentration (0.2mg/l) throughout the distribution system.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.1
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• pp.111-124
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• 2014

Decentralized water supply systems, treating the water in users'vicinity, cutting down the distribution system, utilizing the alternative water resources(rainwater harvesting, water reclamation and reuse and so on.) and saving energy and other resources, could be categorized into POU(Point-Of-Use), POE(Point-Of-Entry) and community small scale system. From the literature review, we could thought that decentralized water supply system and hybrid system(integrating centralized and decentralized water supply system within urban water management) might have strengthening comparative advantages to centralized system with respect to: (1) water security, (2) sustainability, (3) economical affordability. Even though it is difficult to derive and quantify direct benefit advantages from decentralized and hybrid system in comparison with centralized system, (1) operational cost reduction, (2) assurance for safe and stability water supply and (3) greenhouse gas reduction can be expected from successful establishment of the former.

• Journal of the Korean Society of Costume
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• v.7
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• pp.115-126
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• 1983

Myun Bok originated in China was introduced into Korea in ancient times. Some evidences show that it had settlled down as our own official robe already under Koryo Dynasty. And Koryo made her own regulations on Myun Bok. Kook Cho O Rye Eui(國朝五禮儀) of Choson Dynasty has comparatively detailed explanations on the way of cutting and shapes and materials. And the regulations are modeled after those of Ming China. But it has been impossible to know whether the regulations of Kook Cho O Rye Eui were strictly kept or not, because we have not enough remains through which to see it. And then we got very useful materials, Eui kue(儀軌), which are well known but have not been used in studying the history of costumes. Every Kook Chang Do Gam Eui Gue(國葬都監儀軌) have the provision of the so-called Pok Wan(服玩) set which includes the imitations or the full set of Myun Bok. And the provisions show us the illustrations colored in detail which help us understand the real shapes and the transformations of Myun Bok. After surveying the Pok wan provisions, author arrived at conclusions as follow; 1) Myun Boks are not always made in the same shape and colors. 2) The Provisions of Kook Cho O Rye Eui were not always kept strictly due to the lack of detailed directions.