• 제목/요약/키워드: Direct expansion

검색결과 402건 처리시간 0.023초

초기 모스크 건축의 보편적 유형 형성에 '예언자의 집'이 미친 영향에 관한 연구 (Research on influence by Prophet's house in general typologic of the early mosque)

  • 심복기
    • 한국실내디자인학회논문집
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    • 제19권3호
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    • pp.13-21
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    • 2010
  • Early mosque architecture is time that islam attempts fixing since hjira by Muhammad. Before Umayyad dynasty is established a country since islam occurrence, islamic influence was not extended much and stayed in Mecca area. Of course, when is Patriarchal Caliphate period, although there was part territorial expansion, was in existing islam influence still. Regular territorial expansion to Umayyad dynasty several influences and religious conflict happen. Change about islamic architecture occurred much fatally. Therefore, can find islamic archetype about islamic architecture until Prophet Muhammad period and Patriarchal Caliphate period. Also, Muhammad that is Islamic originator participated to mosque architecture directly in life. Can understand philosophy about islamic architecture that Muhammad seeks in mosque architecture. Was age that seek Muhammad's philosophy department religious succession strongly to Patriarchal Caliphate period. Therefore, can understand role of religion, mosque architecture's meaning and role that seek in Islam. It was just before that early mosque architecture receives effect of conquest area or the surrounding country. Therefore, characteristic of mosque received much effect of Prophet Muhammad and qur'an. Do construction according to qur'an's notice based on Prophet's house's function to early mosque. qur'an is no direct delineation as form or architecture element. qur'an refers thing about spiritual aspect or function about special quality of mosque, role etc..

수정 완경사파랑식과 EFEM 평면파 근사식의 해 비교 (Solution Comparisons of Modified Mild Slope Equation and EFEM Plane-wave Approximation)

  • 서승남
    • 한국해안·해양공학회논문집
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    • 제21권2호
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    • pp.117-126
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    • 2009
  • 억류파를 제외한 수정 완경사파랑식과 고유함수 전개법의 평면파 근사식에 대한 정밀도를 검토하기 위해 다수의 수치실험 결과를 제시하였다. 본 연구에서 두 해석해가 사용되었으며 하나는 수정 완경사파랑식에 대한 Porter(2003)의 해이고 다른 하나는 평면파 근사식에 산란체법을 적용한 서(2008a)의 해이다. 급변 지형에서의 파랑변형에 대한 기존 결과와의 직접 비교를 통해 평면파 근사식 모형이 수정 완경사파랑식 보다 잘 기술하는 것으로 나타났다.

고온하의 CW 레이져 스페클 사진법과 화상처리에 의한 열팽창계수 측정에 관한 연구 (Measurement of Thermal Coefficient at High Temperature by CW-Laser Speckle Photography and Image Processing)

  • 김경석;최정석
    • 한국정밀공학회지
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    • 제9권4호
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    • pp.90-99
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    • 1992
  • In resent year Laser Speckle and its development have enabled surface deformation of engineering components and materials to be interferometrically examined. Laser Speckle- Pettern Interferometry Method is a very useful method for measuring In-plane components of displacement. In measuring thermal expansion coefficient, the various problems generated were established, and the measuring limitation examined. Metarial INCONEL 601 was used in experiments. Specimen was heated to the high temperature(100$0^{\circ}C$) by diong current to the direct two specimen. Then, those problems appear to the influence of back-ground radiation by the heated specimen, the influence by air turbulence, the oxidation of specimen. The color monitor and interference filter prevented the back-ground radiation by rad heat. The oxidation occuring in specimen itself was not generated by the being acid-proof excellence of material INCONEL 601. Yet, in this experiments, the serious problems are the oxidation of specimen and influence by air turbulence. By more reserching these problems forward, it is helpful that the thermal expansion coefficient of many materials is directly measured under high temperature.

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원자력 증기발생기 결함 세관 보수용 폭발 Plugging에 관한 연구 (A Study on the Explosive Plugging of A Repair for Defective Tube/Tubeplate on the Nuclear Steam Generator)

  • 이병일;심상한;강정윤;이상래
    • 화약ㆍ발파
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    • 제17권4호
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    • pp.18-31
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    • 1999
  • The explosive forming has been used for many year to expand tubes into tubesheets. this process has demonstrated ability to direct carefully the energy of an explosive to expand tubes into tubesheet holes without damaging the tubesheet and without causing the excessive cold work at the tube I.D. that is normally associated with mechanical expansion. The success of explosive tube expansion provided the background for the development of the explosive tube plug. The main results are as follows : (1) The optimum explosives and explosive qualities are PETN, RDX, HMS and about 18~31gr/ft of explosive plugging in nuclear steam generator. (2) Explosive plugging's thickness is 0.9~1.8mm. If groove of 0.4 mm formed in plug outside, For the hydraulic leakage is go up, explosive plugging of formed groove are applicate tube and tubrplate. (3) Sheath is designed on the polyethylene of low density, In thermal impact test of the $430^\circ{C}$, hydraulic leakage is $300kg/cm^2$. (4) About 10~60mm oxide inclusions are existed on the space of explosive plug and tube protect to the leakage.

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리드 온 칩 패키징 기술을 이용하여 조립된 반도체 제품에서 패시베이션 박막의 TC 신뢰성에 영향을 미치는 요인들 (Factors to Influence Thermal-Cycling Reliability of Passivation Layers in Semiconductor Devices Utilizing Lead-on-Chip (LOC) Die Attach Technique)

  • 이성민;이성란
    • 한국재료학회지
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    • 제19권5호
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    • pp.288-292
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    • 2009
  • This article shows various factors that influence the thermal-cycling reliability of semiconductor devices utilizing the lead-on-chip (LOC) die attach technique. This work details how the modification of LOC package design as well as the back-grinding and dicing process of semiconductor wafers affect passivation reliability. This work shows that the design of an adhesion tape rather than a plastic package body can play a more important role in determining the passivation reliability. This is due to the fact that the thermal-expansion coefficient of the tape is larger than that of the plastic package body. Present tests also indicate that the ceramic fillers embedded in the plastic package body for mechanical strengthening are not helpful for the improvement of the passivation reliability. Even though the fillers can reduce the thermal-expansion of the plastic package body, microscopic examinations show that they can cause direct damage to the passivation layer. Furthermore, experimental results also illustrate that sawing-induced chipping resulting from the separation of a semiconductor wafer into individual devices might develop into passivation cracks during thermal-cycling. Thus, the proper design of the adhesion tape and the prevention of the sawing-induced chipping should be considered to enhance the passivation reliability in the semiconductor devices using the LOC die attach technique.

다성분 혼합연료를 이용한 디젤 분무 및 연소특성의 광계측 진단 (Laser Diagnostics of Spray and Combustion Characteristics Using Multi-Component Mixed Fuels in a D.I. Diesel Engine)

  • 윤준규;명광재;천전이랑;등본원;차경옥
    • 한국자동차공학회논문집
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    • 제14권5호
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    • pp.172-180
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    • 2006
  • This study was to analyze the effect of mixed fuel composition and mass fraction on the characteristics of evaporating diesel spray and combustion under the various ambient conditions. The characteristics of vaporization distribution and combustion were visualized by laser induced fluorescent method and direct photography. The experiments were conducted in the constant volume vessel and rapid compression expansion machine with optical access. Multi-component fuels mixed i-octane, n-dodecane and n-hexadecane were injected the vessel and rapid compression expansion machine with electronically controlled common rail injector. Experimental results show that fuel vapor formed stratified distribution. And vaporization and diffusion are become actively increasing in mass fraction of low boiling point component. Consequently multi-component fuels were expected to control the evaporating behavior according to their suitable mass fraction.

Nd:YVO4 Laser Patterning of Various Transparent Conductive Oxide Thin Films on Glass Substrate at a Wavelength of 1,064 nm

  • Wang, Jian-Xun;Kwon, Sang Jik;Cho, Eou Sik
    • Transactions on Electrical and Electronic Materials
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    • 제14권2호
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    • pp.59-62
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    • 2013
  • At an infra-red (IR) wavelength of 1,064 nm, a diode-pumped Q-switched $Nd:YVO_4$ laser was used for the direct patterning of various transparent conductive oxide (TCO) thin films on glass substrate. With various laser beam conditions, the laser ablation results showed that the indium tin oxide (ITO) film was removed completely. In contrast, zinc oxide (ZnO) film was not etched for any laser beam conditions and indium gallium zinc oxide (IGZO) was only ablated with a low scanning speed. The difference in laser ablation is thought to be due to the crystal structures and the coefficient of thermal expansion (CTE) of ITO, IGZO, and ZnO. The width of the laser-patterned grooves was dependent on the film materials, the repetition rate, and the scanning speed of the laser beam.

3차원 파넬방법에 의한 파중 선박의 조종성능 해석 (Analysis of Manoeuvrability of a Ship in Waves by 3-Dimensional Panel Method)

  • 안성필;이기표
    • 대한조선학회논문집
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    • 제31권4호
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    • pp.82-98
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    • 1994
  • 본 논문에서는 파중에서 조종운동을 하는 선박에 작용하는 유체력에 대한 수학적 모델을 확립하고, 이에 대한 수치해석을 수행하였다. 파중에서 운항하는 선박은 입사파의 주파수에 의존하는 고주파수 운동과 선박의 조종운동에 따른 저주파수 운동을 하게되므로, two time scale expansion 방법을 적용하여 속도포텐셜에 대한 선형경계치 문제를 정립하였으며, 선박의 조종운동에 미치는 파의 영향은 2차차수 저주파수 표류력만을 조종운동방정식에 포함시켜 고려하였다. 속도포텐셜에 대한 적분방정식의 해는 3차원 파넬방법을 사용하여 구하였으며, 선박에 작용하는 힘은 직접적분법을 사용하여 계산하였다.

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Evidence for a decelerating cosmic expansion from supernova cosmology

  • Lee, Young-Wook
    • 천문학회보
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    • 제46권1호
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    • pp.27.3-27.3
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    • 2021
  • Supernova (SN) cosmology is based on the assumption that the width-luminosity relation (WLR) in the type Ia SN luminosity standardization would not vary with progenitor age. Unlike this expectation, recent age datings of stellar populations in host galaxies have shown significant correlations between progenitor age and Hubble residual (HR). It was not clear, however, how this correlation arises from the SN luminosity standardization process, and how this would impact the cosmological result. Here we show that this correlation originates from a strong progenitor age dependence of the WLR and color-luminosity relation (CLR), in the sense that SNe from younger progenitors are fainter each at given light-curve parameters x1 and c. This is reminiscent of Baade's discovery of two Cepheid period-luminosity relations, and, as such, causes a serious systematic bias with redshift in SN cosmology. We illustrate that the differences between the high-z and low-z SNe in the WLR and CLR, and in HR after the standardization, are fully comparable to those between the correspondingly young and old SNe at intermediate redshift, indicating that the observed dimming of SNe with redshift is most likely an artifact of over-correction in the luminosity standardization. When this systematic bias with redshift is properly taken into account, there is no evidence left for an accelerating universe, and the SN data now support a decelerating cosmic expansion. Since the SN cosmology has long been considered as the most direct evidence for an accelerating universe with dark energy, this finding poses a serious question to one of the cornerstones of the concordance model.

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공동주택의 엘리베이터 수직 확장 공사를 위한 사전 검토항목 (Preliminary Checklist For Vertical Extension of Elevator in Apartment Buildings)

  • 박진구;이찬식
    • 한국건설관리학회:학술대회논문집
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    • 한국건설관리학회 2008년도 정기학술발표대회 논문집
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    • pp.813-816
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    • 2008
  • 국민소득의 증가로 인한 개개인의 보유 차량의 증가는 심각한 주차장 부족현상을 초래하였다. 특히 노후공동주택의 경우 인근도로까지 주차장으로 변해버리면서 심각한 교통체증을 겪고 있는 것은 물론 화재 등 위급 상황 발생에 대처하지 못하는 사회적인 문제를 야기하고 있다. 이러한 문제점에 대한 대책으로 노후 공동주택의 리모델링이 논의되고 있으나·주차장확대 시공에 대한 연구는 미흡한 실정이다. 노후 공동주택 리모델링에 관한 설문조사 결과 공동주택 리모델링 시 최우선 개선사항으로 주차장 부족이 30% 이상의 비율을 차지하였고 주차장확대 방법은 지하수평확대방식 중 직접진입방식을 선호하였다. 지하직접진입방식은 주차장에 서 엘리베이터를 통해 단위세대로 직접 진입하는 방식으로 엘리베이터의 연장운행이 필요하다. 하지만 엘리베이터확장을 위한 체계적인 공정이 정립되어 있지 않고 시공사례가 부족하여 비효율적으로 엘리베이터 확장이 이루어지고 있다. 본 연구는 효율적인 엘리베이터확장 공사를 위한 검토항목을 제시하기 위해 공정을 재분석하였고 전문가의 면담을 통해 공정별로 관리적 측면, 기술적 측면의 검토항목을 도출하였다. 본 연구는 공동주택의 지하주차장 증설에 따른 엘리베이터확장 공사 시 참고자료로 활용 될 것이다.

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