• 대한견주관절학회:학술대회논문집
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• 대한견주관절학회 2007년도 제15차 대한견주관절학회 및 제3차 Mayo Asia Elbow Club 합동 학술대회
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• pp.25-26
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• 2007

• 임산에너지
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• 제19권2호
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• pp.79-85
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• 2000

월악산에 소재하여 있는 소나무림을 대상으로 조사 분석함으로써 소나무림의 숲틈형성과 재생 및 천이에 관하여 다음과 같은 결과를 얻었다. (1) 월악산 소나무림을 이루고 있는 수종들로는 교목층으로 소나무와 굴참나무가 우점하고 있으며, 중층으로는 신갈나무, 졸참나무, 쇠물푸레 등의 수종이 우점하고 있다. (2) 소나무림의 숲틈형성요인으로서 고사목의 고사유형은 입목고사형이 가장 많았다. (3) 흉고직경급별 분포를 분석한 결과 소나무림은 먼저 굴참나무림으로 바뀌다가 다시 신갈나무와 졸참나무로 천이가 진행될 것으로 판단되었다. (4) 소나무 치수는 건조한 지역에서 생성된 숲틈에서만 발견되고 있어 이러한 지역에서만 환경적 극상으로서 소나무림이 유지될 가능성을 조여주고 있었다.

• 대한기계학회논문집B
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• 제24권3호
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• pp.435-442
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• 2000

The present study is conducted to investigate the local heat/mass transfer characteristics for flow through perforated plates. A naphthalene sublimation method is employed to determine the local heat/mass transfer coefficients on the effusion plate. Two parallel perforated plates are arranged for the two different ways: staggered and shifted in one direction. The experiments are conducted for hole pitch-to-diameter ratios of 6.0, for gap distance between the perforated plates of 0.33 to 10 hole diameters, and for Reynolds numbers of 5,000 to 12,000. The result shows that the high transfer region is formed at stagnation region and at the mid-line of the adjacent impinging jets due to secondary vortices and flow acceleration to the effusion hole. For flows through the perforated plates, the mass transfer rates on the surface of the effusion plate are about six to ten times higher than for effusion cooling alone (single perforated plate). More uniform and higher heat/mass transfer characteristic is obtained in overall region with small gap between two perforated plates.

• 한국전자파학회논문지
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• 제27권10호
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• pp.945-948
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• 2016

최근 프리미엄급 스마트폰들은 대부분 메탈 프레임을 채용하고 있으며, 이는 중저가 스마트폰으로 확산되고 있는 추세이다. 하지만, 메탈 프레임은 스마트폰 내 디지털 부품에서 발생하는 전자파 노이즈의 좋은 전달 경로가 되어, 스마트폰 상단부 또는 하단부에 위치한 무선 안테나에 전자파 간섭을 일으키는 원인이 될 수 있다. 본 논문에서는 메탈 프레임에 EBG(Electromagnetic Band Gap) 구조를 적용하여 안테나로의 전자파 간섭을 줄일 수 있는 방법을 제안하였다. $7{\times}6$ 배열의 다중 비아(Multi-via) EBG 구조를 갖는 메탈 프레임을 설계하였으며, 이를 적용할 경우, 메탈 프레임을 통한 표면 전자파 노이즈 간섭을 20 dB 정도 저감시킬 수 있음을 시뮬레이션을 통해 확인하였다.

• Wind and Structures
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• 제15권6호
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• pp.531-553
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• 2012

Many tall buildings possess through-building gaps at middle levels of the building elevation. Some of these floors are used as sky gardens, or refuge floors, through which wind can flow with limited blockage. It has been reported in the literature that through-building gaps can be effective in reducing across-wind excitation of tall buildings. This paper systematically examines the effectiveness of two configurations of a through-building gap, at the mid-height of a tall building, in reducing the wind-induced dynamic responses of the building. The two configurations differ in the pattern of through-building opening on the gap floor, one with opening through the central portion of the floor and the other with opening on the perimeter of the floor around a central core. Wind forces and moments on the building models were measured with a high-frequency force balance from which dynamic building responses were computed. The results show that both configurations of a through-building gap are effective in reducing the across-wind excitation with the one with opening around the perimeter of the floor being significantly more effective. Wind pressures were measured on the building faces with electronic pressure scanners to help understand the generation of wind excitation loading. The data suggest that the through-building gap reduces the fluctuating across-wind forces through a disturbance of the coherence and phase-alignment of vortex excitation.

• Nuclear Engineering and Technology
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• 제37권6호
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• pp.565-574
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• 2005

The CANFLEX Mk-V bundle is designed to improve upon the critical heat flux (CHF) characteristics of the CANFLEX Mk-IV bundle. The main difference between these two bundles is an increase in bearing pad height of about 0.3 mm in the CANFLEX Mk-IV bundle. This change in bearing pad height leads to an increase in gap flow at the bottom of the bundle, primarily eliminating the localized narrow-gap effect that limits the CHF of the CANFLEX Mk-IV bundle. The objective of this paper is to examine the effects of bearing pad height and pressure tube creep on the sheath-temperature distribution, dryout power, and dryout location, as observed ken full-scale bundle tests, between CANFLEX Mk-IV and Mk-V bundles In uncrept and crept channels. A comparison of surface-temperature differences between the top and bottom elements of the bundles showed that increasing the bearing pad height has led to a more homogeneous enthalpy distribution in subchannels of the bundle. Initial dryout locations of the CANFLEX Mk-V bundle were mainly observed at the mid-spacer plane of either the $10^{th}$ (about $80\%$) or $11^{th}$ ($20\%$) bundle in the 12-bundle string, as compared to the mid-spacer and downstream-button planes for the CANFLEX Mk-IV bundle. Dryout power and boiling-length-average (BLA) CHF values exhibit consistent trends and little scatter with varying flow conditions for both types of CANFLEX bundles in uncrept and crept channels. An increase in pressure tube creep has led to a reduction in dryout power (about $20\%$ far the $3.3\%$ crept channel and $27\%$ for the $5.1\%$ crept channel as compared to dryout powers for the uncrept channel). Increasing the bearing pad height of the CANFLEX bundle has led to an increase in the dryout power. Overall, the dryout power of the CANFLEX Mk-V bundle is 7 to $10\%$ higher than that of the CANFLEX Mk-IV bundle at the inlet temperature range of interest (i.e., between 243 and $290^{\circ}C$).

• The Journal of Advanced Prosthodontics
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• 제6권4호
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• pp.253-258
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• 2014

PURPOSE. To compare marginal and internal gaps of zirconia substructure of single crowns with those of three-unit fixed dental prostheses. MATERIALS AND METHODS. Standardized Co-Cr alloy simulated second premolar and second molar abutments were fabricated and subsequently duplicated into type-III dental stone for working casts. After that, all zirconia substructures were made using $Lava^{TM}$ system. Marginal and internal gaps were measured in 2 planes (mesial-distal plane and buccal-palatal plane) at 5 locations: marginal opening (MO), chamfer area (CA), axial wall (AW), cusp tip (CT) and mid-occlusal (OA) using Replica technique. RESULTS. There were significant differences between gaps at all locations. The $mean{\pm}SD$ of marginal gap in premolar was $43.6{\pm}0.4{\mu}m$ and $46.5{\pm}0.5{\mu}m$ for single crown and 3-unit bridge substructure respectively. For molar substructure the $mean{\pm}SD$ of marginal gap was $48.5{\pm}0.4{\mu}m$ and $52.6{\pm}0.4{\mu}m$ for single crown and 3-unit bridge respectively. The largest gaps were found at the occlusal area, which was $150.5{\pm}0.5{\mu}m$ and $154.5{\pm}0.4{\mu}m$ for single and 3-unit bridge premolar substructures respectively and $146.5{\pm}0.4{\mu}m$ and $211.5{\pm}0.4{\mu}m$ for single and 3-unit bridge molar substructure respectively. CONCLUSION. Independent-samples t-test showed significant differences of gap in zirconia substructure between single crowns and three-unit bridge (P<.001). Therefore, the span length has the effect on the fit of zirconia substructure that is fabricated using CAD/CAM technique especially at the occlusal area.

• 한국지역지리학회지
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• 제16권5호
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• pp.537-548
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• 2010

중국경제의 비약적인 발전과 더불어 지역 간 소득격차 문제는 더 이상 간과할 수 없는 사회적인 문제로 대두되고 있다. 따라서 본 연구는 중국의 동 중 서 3대 지역 도농 간 주민소득 격차의 현주소를 살펴보고 이와 같은 구조가 형성된 원인을 실증분석 하였다. 분석 결과 경제발전 정도가 상이한 3대 지역의 주민소득에 영향 주는 요인이 각자 다른 것으로 나타났다. 동부지역의 경우 정부의 교육지원 요인이 지역 내 도농 간 소득격차를 가장 효과적으로 완화시켜 주고 있는 것으로 나타났으며 특히 최근에 그 영향 정도가 점차 뚜렷해지는 추세를 보이고 있다. 그리고 중부지역의 경우 공업화 요인이 도농 간 소득격차를 효과적으로 완화시키고, 서부지역의 경우 정부의 농업생산지원 요인이 도농 간 소득격차를 효과적으로 완화시켜 주고 있는 것으로 나타났다. 따라서 중국 각 지역의 도농 간 소득격차 문제를 해소함에 있어 중국 전역에서 도사와 농촌을 모두 아우르는 통합적인 의료보험정책이나 사회복지정책 등을 추진시키는 것도 중요하지만 동부지역 지방정부의 교육비 지원 증가, 중부지역 지방정부의 공업추진특별정책, 서부지역 지방정부의 농업생산지원 증가 등 지역적 정책조치도 시급하다는 결론을 얻었다.

• 산경연구논집
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• 제8권5호
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• pp.43-52
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• 2017

Purpose - The domestic liquor market is steadily increasing, but locally made liquor markets remain stagnant. The market opening due to the FTA and westernized eating habits are expanding the consumption of imported liquor by Koreans and the demand for beer and soju is still high. Therefore, we analyzed the scale efficiency of Korean locally made liquor companies. Research design, data, and methodology - Based on a translog-cost function, a scale efficiency analysis was conducted using the government's information survey on the liquor industry. Data from 541 liquor companies analyzed from 2013 to 2014 were used for analysis. Results - As a result of the scale efficiency analysis, the average sales of the mid-sized locally made liquor companies is 171 million won, but the appropriate sales amount is 1 million won. It is estimated that there is a need to increase sales. Conclusions - The gap between the actual sales and the appropriate sales of mid-sized locally made liquor companies with 3~10 employees is larger, so it is necessary to reduce the average cost by increasing the sales of locally made liquor companies. In order to do so, it is necessary to acquire customer strategies such as product differentiation, advertising and publicity.

• Earthquakes and Structures
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• 제22권3호
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• pp.319-330
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• 2022

Retrofit of soft-story buildings due to seismic loads using Gap-Inclined-Brace (GIB) system is considered a new retrofit technique that aims to maintain both strength and stiffness of structure. In addition, it provides more ductility and less P-delta effect, and subsequently better performance is observed. In this paper, the effect of the eccentricity between GIB and the retrofitted column due to installation on the efficiency of the retrofitting system is studied. In addition, a modification in the determination method of GIB properties is introduced to reduce the eccentricity effect. Also, the effect of GIB system on the seismic response of mid-rise buildings with different heights considering soft-story at various heights has been studied. A numerical model is developed to study the impact of such system on the response of retrofitted soft-story buildings under the action of seismic loads. To achieve that goal, this model is used to perform a numerical investigation, by considering five case study scenarios represent several locations of soft-story of two mid-rise reinforced concrete buildings. At first, Non-linear static pushover analysis was carried out to develop the capacity curves for case studies. Then, Non-linear time history analyses using ten earthquake records with five peak ground accelerations is performed for each case study scenario before and after retrofitting with GIB. The results show that large GIB eccentricity reduce the ultimate lateral resistance and deformation capacity of the retrofitting system. Moreover, the higher the retrofitted building, the more deformation capacity is observed but without significant increase in ultimate lateral resistance.