• 대한공업교육학회지
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• v.35 no.2
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• pp.224-237
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• 2010

When the underwater structure sails high speed, noise and vibration propagate to the sensor in the nose of the dome. In this paper, to avoid this kind of noise and vibration CRP(Carbon Reinforced Plastic) material and SNORE ring(Self-NOise REduction Ring) are attached at the curved structure and simulates its isolation characteristics using commercial software. Vibration displacement and stress are calculated at the planar sensor array. The material of the curved structure is aluminum and maximum outer diameter is 53Omm, 215mm in length, 270mm in planar diameter, respectively. Based on the simulation results, reduction ratio of the received normal stress at the sensor is above 95% at the frequency of 12kHz and 15kHz. At the mid point of the planar sensor the normal stress is higher than 20mm and 40mm apart. This results can be used to increase the sensitivity of the acoustic sensor as a basic data.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.2
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• pp.10-18
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• 2011

In order to develop highly-integrated RGBY(Red, Green, Blue, Yellow) LED light, a high thermal radiation ceramic package was manufactured, and the encapsulation process was applied with a vacuum printing encapsulation system(VPES). After the completion of vacuum printing, the shape of the encapsulation layer could be controlled by heat treatment during the curing process, and the optical power became highly increased as the encapsulation layer approached a dome shape. The optical characteristics involved in a Correlated Color Temperature(CCT), a Color Rendering Index (CRI), and the efficiency of RGBY LED light were able to be identified by the experimental designing method. Regarding the characteristics of the white light of RGBY LED light, which were measured on the basis of the aforementioned optical characteristics, CRI posted 88, CCT recorded 5,720[$^{\circ}K$], and efficiency exhibited 52[lm/W]. The chip temperature of RGBY LEDs was below 55[$^{\circ}C$] when the consumption power of LED chips was 0.1[W] for the red, 0.3[W] for the green, 0.08[W] for the blue, and 0.24[W] for the yellow. Also, the thermal resistance of the highly-integrated RGBY LED light measured by T3Ster was 2.3[K/W].

• Journal of Korean Foot and Ankle Society
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• v.5 no.2
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• pp.103-111
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• 2001

Purpose: The purpose of this study was to evaluate prognostic factors of ankle arthroscopy and the effectiveness of high anteromedial and anterolateral portals in diagnosis and treatment for various disease entities. Materials and Methods: The results of ankle arthroscopy were evaluated between March 1992 and January 2000 by one surgeon. Total 169 patients who were followed for a minimum of 12 months, were included in this study. Using high anteromedial and high anterolateral portals, all procedures were done with accessory portals if necessary. A functional evaluation was performed using the Karlsson score and questionnaire subjectively. Results: Fifty-six synovial impingement, 48 osteochondral lesion on talus, 10 impingement exostosis, 8 loose body, 27 osteoarthritis and chondromalacia, 10 postfracture fibrosis, 3 lateral plica, and 1 pigmented villonodular synivitis(PVNS) among 169 patients were diagnosed. Patients with the former four groups had satisfactory results and the latter four groups had not. Remaining 6 patients underwent arthroscopic arthrodesis, and 5 had satisfactory results. Conclusion: Using high anteromedial and anterolateral portals, we could get better visualization of talar dome and posterior chamber of ankle. For better clinical results, in ankle arthroscopy, not only operative skill but also proper indications are important. In case of synovial impingement after trauma, arthroscopy should be considered within one year after initial trauma. There were little correlation between the radiographic findings and arthroscopic findings of articular cartilage in osteochondral lesion of talus, and it is better to determine treatment modality based on the arthroscopic or MRI findings. Osteochondral lesions were treated successfully only when they were traumatically induced and localized without diffuse chondromalacia of talus and tibia.

• Journal of Korean Foot and Ankle Society
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• v.8 no.2
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• pp.157-160
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• 2004

Purpose: This study aimed to investigate and compare the micro-structural profiles of trabecular bone from different facets at the ankle joint. Materials and Methods: In a fresh cadaver ankle, four cored 10 mm of diameter cylindrical specimens of trabecular bone were harvested from the distal tibia, the talar dome, the medial malleolus, and the lateral malleolus. Using a micro-computed tomography, two-dimensional and three-dimensional micro-structural indices of the trabecular bone were analyzed. Results: Each specimen from the tibia, talus, medial malleolus, and the lateral malleolus showed unique micro-structural pattern. Tibia versus talus, the talus was seen a higher bone volume fraction and a wider supporting zone subchondrally whereas the tibia was seen a relatively lower bone volume fraction and a much narrower supporting zone subchondrally. Lateral malleolus versus medial malleolus, the lateral malleolus was seen the thicker but sparse trabeculae pattern whereas the medial malleolus was seen the thinner but more compact trabecular pattern. Conclusion: Each four locations from the different facet at the ankle joint have distinct own micro-structural patterns of the trabecular bone, suggesting different mechanical properties.

• Fashion & Textile Research Journal
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• v.18 no.3
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• pp.272-281
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• 2016

From the year 2000 on, Seoul has aimed to be a fashion city, and thus has been supporting young designers through Seoul Fashion Creative Studio, Generation Next, Le Dome, Concept Korea, etc. London is famous for nurturing young designers through the joint help of government, schools and industries: Alexander McQueen, Christopher Kane and Peter Pilotto are successful cases. Therefore, this research aims to suggest a direction for policies aimed at helping young designers in the international market, on the basis of London's nurturing programs and ideas from a literature review and case studies. The results are below. Firstly, a step-by-step supporting program is recommended. Secondly, long-lasting, sustainable programs are considered essential to support designers after the end of their contracts. Thirdly, practical assistance is preferred to monetary funding in order to lighten the designers' lot and in the interests of transparency. The mentoring service should be strengthened for the designers to eventually become independent. The support should be tailor-made according to items. Fourthly, the supporting programs should be promoted. Fifthly, government and industries should collaborate. Sixthly, 'de minimis' against overlapped support should be legislated. For these, the change of supporting method can be helpful; an independent administrative organisation plans and collects funds from governments and companies. Through these programs and any subsequent studies, Seoul could become a fashion city where young designers play active roles at a global level.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.4 s.121
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• pp.342-349
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• 2007

Following the 2002 World-Cup held in Korea, studies have been actively conducted on plans to utilize all-weather stadiums of fine figures, where large-scale spaces are available for various utilizations. In Japan, dome-type stadiums have been built and are utilizing across the whole nation not only for sports events but also variety of other large-scale events. PTFE(poly tetra fluoro ethylene) is one of the membrane material mainly used for the outer ceiling surface of membrane structures. However, there has not been enough research on the acoustical properties of PTFE membrane material which has been widely used in the multi-purpose stadiums. In this study, air permeability values and sound absorption coefficient of PTFE membrane materials were measured and evaluated in the gymnasium. From the results of measurements of sound absorption coefficient and air permeability of inner membrane materials, it was found that the sound absorption coefficient was good in the air permeability range of $5{\sim}15\;cc/cm^2/s$. Also the relation ship between air permeability and sound absorption coefficient was very high and the sound absorption coefficient was the highest in the range of $6{\sim}9\;cc/cm^2/s$. Secondly, an analysis on the measurements sound absorption characteristics of inner membrane material reveals that the overall sound absorption coefficient was stabilized(higher than 0.5 throughout the whole frequency bands) when the air space behind the membrane material was deeper than 600 mm. When PTFE sound absorptive membrane material was installed in the ceiling of gymnasium, it was confirmed that sound absorptive membrane material can reduce reverberation and increase speech intelligibility in the gymnasium.

• Journal of Conservation Science
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• v.8 no.1 s.11
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• pp.1-9
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• 1999

The present aspect of the Seoggulam is the result of natural weathering of the rocks and influences by mankind. The rocks constituting the Seoggulam is granodiorite of medium and coarse grains which show brown to dark brown weathered surface resulted mainly from chemical weathering of feldspars. It also shows partly milky white or black colors due to influences by weathering products of cement used in the concrete dome and cracks. There are cracks and crack zones with very small cracks which may be formed by strong weathering and influences of shocks during operations of reconstitution and repair. However, for the better conservation, it must be considered to maintain the balances of temperature and moisture, especially relative moisture in places within the room, structural stability, and the influences of vibration made up by some reasons.

• Wind and Structures
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• v.23 no.6
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• pp.505-521
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• 2016

The objective of this study is to investigate numerically the effect of building roof shaps on wind flow and pollutant dispersion in a street canyon with one row of trees of pore volume, $P_{vol}=96%$. A three-dimensional computational fluid dynamics (CFD) model is used to evaluate air flow and pollutant dispersion within an urban street canyon using Reynolds-averaged Navier-Stokes (RANS) equations and the Explicit Algebraic Reynolds Stress Models (EARSM) based on k-${\varepsilon}$ turbulence model to close the equation system. The numerical model is performed with ANSYS-CFX code. Vehicle emissions were simulated as double line sources along the street. The numerical model was validated by the wind tunnel experiment results. Having established this, the wind flow and pollutant dispersion in urban street canyons (with six roof shapes buildings) are simulated. The numerical simulation results agree reasonably with the wind tunnel data. The results obtained in this work, indicate that the flow in 3D domain is more complicated; this complexity is increased with the presence of trees and variability of the roof shapes. The results also indicated that the largest pollutant concentration level for two walls (leeward and windward wall) is observed with the upwind wedge-shaped roof. But the smallest pollutant concentration level is observed with the dome roof-shaped.

• Journal of Astronomy and Space Sciences
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• v.12 no.1
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• pp.90-101
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• 1995

We determined three dimensional precise WGS 84 corrdinates of two points in Bohyunsan Optical Astronomy Observatory using the GPS. One of the two points is the center on the top of pier for 1.8m telescope, and the other one is placed on the hill beside the dome of 1.8m telescope. We performed the simultaneous GPS observation at the KAO GPS station and Bohyunsan Obervatory for 5 days from December 18 to 22, 1993. We employed three Trimble 4000SST receivers for these observations. The observed data were processed by TRIMVEC-PLUS software of Trimble with the MBPS method and the Triple Difference L1/L2 ION free technique. Through this research, we determined WGS 83 latitude, longitude and height of 1.8m telescope in Bohyunsan Optical Astronomy Observatory with the values of $36^{circ}9'53".1943N\pm0."0018,\;128^{circ}58'35".6829E\pm0."0029,\;1162.47m\pm0.04m$, respectively.

• Journal of Korean Neurosurgical Society
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• v.48 no.3
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• pp.207-212
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• 2010

Objective : To assess the feasibility, safety, and effectiveness of the balloon-assisted technique with HyperForm balloon in the endovascular treatment of wide-necked intracranial aneurysms. Methods : A total of 34 patients with 34 wide-necked intracranial aneurysms were treated with endovascular coil embolization using balloon-assisted technique with Hyperform balloon. Twenty-nine aneurysms (85.3%) were located in the anterior circulation. The group of patients was comprised of 16 men and 18 women, aged 33 to 72 years (mean : 60.6 years). The size of aneurysms was in the range of 2.0 to 22.0 mm (mean 5.5 mm) and one of neck was 2.0 to 11.9 mm (mean 3.8 mm). The dome to neck ratio was ranged from 0.83 to 1.43 (1.15). Sixteen patients were treated for unruptured aneurysms and the remaining 18 presented with a subarachnoid hemorrhage. Results : In the 34 aneurysms treated by the remodeling technique with HyperForm balloon, immediate angiographic results consisted of total occlusion in 31 cases (91.2%) and partial occlusion in three cases (8.8%). There were five procedure-related complications (14.7%), including two coil protrusions and three thromboembolisms; Except one patient, all were successfully resolved without permanent neurologic deficit. No new bleeding occurred during the follow-up. Twenty patients (59%) underwent angiographic follow-up from 2 to 33 months (mean 9.2 months) after treatment. Focal recanalization with coil compaction of the neck portion was observed in 5 cases (25%). Only one case showed major recanalization and underwent stent-assisted coil embolization. Conclusion : The balloon-assisted technique with Hyperform balloon is a feasible, safe, and effective endovascular treatment of wide-necked cerebral aneurysms.