• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.305-310
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• 2004

The Hot Embossing Lithography(HEL) as a method for the fabrication of nanostructure with polymer is becoming increasingly important because of its simple process, low cost, high replication fidelity and relatively high throughput. In this study, we investigated the characteristics of hot embossing lithography as a nanoreplication technique. To grasp characteristics of nano patterning rheology by process parameters(embossing temperature, pressure and time), we have carried out various experiments by using the DVD(400nm pattern width) and Blu-ray nickel stamps(150nm pattern width). During the hot embossing process, we have observed the characteristics of the size effect. The quality of products made by hot embossing is affected by its cooling shrinkage. The demolding process at the glass transition temperature results in low quality because of the shrinkage of the polymer. Therefore, the quantification of the temperature condition is essential for the replication of high quality.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.200-203
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• 2008

Water mist fire suppression system utilizes the fire suppression features such as cooling of fire source, dilution of ambient oxygen, and shielding of radiation heat with the evaporation of microscopic water droplets. The momentum of water mist is relatively low and the infiltration of water mist to the fire source is not effective. In addition to lower penetration force, the evaporated water vapor is liable to decline to limited portion of fire source due to its light weight and sparse density. On the other hand, the cycling water mist system is expected to improve the penetration force of water mist as well as the dilution coverage capability with the stratified spray characteristics. At this paper we present the analyzed fire suppression capability of intermittent water spray pattern by use of FDS which is computational fire dynamics fire model. We expect this analysis shall be supportive to the development of the prototype of water mist nozzle.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.11a
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• pp.97-102
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• 2002

Resident's agreeableness anger elevation request by improvement of life environment with economy development is increasing recently. However, research about air current estimation in dwelling environment that make use of air conditioner summer and cooling room is lacking going yet much. We are going to prefer most air current pattern(speed 3 steps of swing) that offer in PAC after figure processing because user's life hysteresis and present air current pattern that is supposed and offer more agreeable environment to room resident.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1761-1766
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• 2004

Recently, Plastic optical products are widely used. Injection molding process has advantages of low cost and high productivity. However, it remains a residual birefringence and residual stress by difference cooling. The present study focused on measuring birefringence in optical plastic parts using interference color pattern. The main idea of an analysis comes from chromatic aberration which is caused by difference light wavelengths. As a result, a complete system measuring the high order 2-D birefringence pattern was built. Further investigation is under way to improve the accuracy of birefringence measurement system by diode laser.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.9
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• pp.1201-1208
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• 2002

A numerical flow-field analysis is performed to investigate flow configurations in the anode, cathode and cooling channels on the bipolar plates of a proton exchange membrane fuel cell (PEMFC). Continuous open-faced flow channels are formed on the bipolar plate surface to supply hydrogen, air and water. In this analysis, two types of channel pattern are considered: serpentine and spiral. The averaged pressure distribution and velocity profiles of the hydrogen, air and water channels are calculated by two-dimensional flow-field analysis. The equations for the conservation of mass and momentum in the two-dimensional fluid flow analysis are slightly modified to include the characteristics of the PEMFC. The analysis results indicate that the serpentine flow-fields are locally unstable (because two channels are cross at right angles). The spiral flow-fields has more stable than the serpentine, due to rotational fluid-flow inertia forces. From this study, the spiral channel pattern is suggested for a channel pattern of the bipolar plate of the PEMFC to obtain better performance.

• The Journal of Korean Medicine
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• v.16 no.1 s.29
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• pp.370-378
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• 1995

In order to consider the clinical efficacy of moxa combustion, understand the quality and quantity of heat stimulation and get the basic data for the development of electric moxibustion apparatus, the pattern of combustion temperature was measured by size of moxa(small, medium, large and maximum size). The results were as follows. 1. The pattern of combustion temperature by moxa burning was classified into input period, consisting of preheating and heating periods, and output period, consisting of heat retaining and cooling periods, in all experimental groups. But it was difficult to observe the preheating period in small sized moxa. 2. It was inclined that the more moxa size was large, the more the heating and heat retaining periods were long and the maximum temperature was high. The characteristics of moxa combustion is primarily by the rate of combustion temperature, gradient temperature and duration of combustion, and their correlation among these factors and their clinical effects in practice.

• Tribology and Lubricants
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• v.30 no.5
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• pp.265-270
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• 2014

Frictional heat greatly influences the friction behaviors during clutch engagement. Therefore, the engagement of a wet or dry clutch is frequently not under control by the frictional heat. In a wet clutch, the frictional temperature also specially needs to be controlled, and in many cases, the clutch material is selected to prevent a temperature rise from the friction between friction pad and separator. However, only the selection of the clutch material cannot ensure sufficient control of the temperature rise by the friction. The groove pattern on a friction pad is designed for more flow rates of transmission fluid between the contact gap of clutch pad and separator for the cooling effect. In this work, grove patterns are designed for more flow rates out of the contact gap between friction pad and separator plate. Selected groove design shows the improvement flow rates of transmission fluid through both inner and outer radius, where most of the transmission fluid flows through the outer radius when the clutch is engaged due to the centrifugal force in conventional wet clutch groove. Several comparisons of the amounts of frictional heat generated on clutch pads are made in order to verify the decrease of the temperature rise according to the flow rates along the groove patterns.

• Journal of muscle and joint health
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• v.17 no.2
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• pp.151-161
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• 2010

Purpose: The purpose of this study was to identify the effect of Tai Chi exercise on loneliness, sleep pattern, and instrumental activities of daily living in elderly women. Methods: A quasi-experimental design, a nonequivalent control group pretest-posttest was used. Elderly women who agreed to participated in the study were assigned into an experimental group (n=20) or a control group (n=20). The experimental group participated in Tai Chi exercise program (Sun-style 12 forms) for 50 minutes per session, 2 times a week for 8 weeks. Tai Chi exercise program consisted of 10 minutes for warm-up, 35 minutes for main session, and 5 minutes for cooling down. Study outcomes were measured through study questionnaires. Data were analyzed using Chi-square test, t-test and Mann-Whitney test by SPSS WIN 14.0 program. Results: Compared with the control group, the experimental group showed significant improvement in loneliness (t=-2.733, p=.009), sleep pattern (t=2.552, p=.015), and instrumental activities of daily living (z=-2.171, p=.030). Conclusion: Tai Chi exercise program may be an effective nursing intervention for elderly women.

• Korean Journal of Metals and Materials
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• v.46 no.6
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• pp.377-381
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• 2008

Prism sheet of LCD BLU which depends on supply from Japan and U.S.A was studied by using Si anisotropic etching and injection molding technologies. First, the prism sheet was patterned on Si wafer through photolithography, and the best conditions of Si etching were determined through etching Si wafer with TMAH to obtain straight optimized zigzag patterns, and a cross pattern to provide light diffusion and concurrent focusing. The etch rate of TMAH was concluded to be constant for $25wt%-70^{\circ}C$ condition. Ni stamp of prism sheet was made by electrodeposition using patterned Si wafer, normal or fast H/C(Heating/Cooling) injections were carried out to fabricate prism sheet. It was known that fast H/C injection could fabricate prism sheet more accurately than normal injection. Zigzag patterns and the cross pattern showed higher transmissivity than the straight patterns because of light diffusion through diagonal direction. The fast H/C injection for zigzag patterns showed lower transmissivity than normal injection because there occurred more light diffusion through precise injection patterns, but the fast H/C injection for straight patterns showed only refraction without diffusion, causing lower transmissivity than normal injection.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.10
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• pp.109-115
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• 2016

In this paper, In this paper, we use two methods to compare the slim speakers. That way, the diaphragm scan using laser and diaphragm photographed using a thermal imaging camera. Slim speaker has the structure of a flat plate type. Break-up mode by this characteristic is displayed in a larger size. Further, since the installation space is narrow, it has limited moving coil cooling. As a result, the break-up mode slim speakers, a significant impact on quality. In this study, try to connect the break-up mode of the diaphragm, the heat transfer mode of the diaphragm. Experiment for comparison, a two-step. The first step is to measure the divided vibration through the vibration plate scan. The second step measures the diaphragm photographed using a thermal imaging camera. Then, compare the results of both of the same frequency. Thus, comparing the heat transfer pattern and the pattern of break-up mode. Tend to be analysis of break-up mode from the pattern comparison, and document for the optimum design.