• 제목/요약/키워드: incorporation by reference

검색결과 31건 처리시간 0.025초

Post-earthquake fire performance-based behavior of reinforced concrete structures

  • Behnama, Behrouz;Ronagh, Hamid R.
    • Earthquakes and Structures
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    • 제5권4호
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    • pp.379-394
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    • 2013
  • Post-earthquake fire (PEF) can lead to a rapid collapse of buildings damaged partially as a result of prior earthquake. Almost all standards and codes for the design of structures against earthquake ignore the risk of PEF, and thus buildings designed using those codes could be too weak when subjected to a fire after an earthquake. An investigation based on sequential analysis inspired by FEMA356 is performed here on the Immediate Occupancy, Life Safety and Collapse Prevention performance levels of structures, designed to the ACI 318-08 code, after they are subjected to an earthquake level with PGA of 0.35g. This investigation is followed by a fire analysis of the damaged structures, examining the time taken for the damaged structures to collapse. As a point of reference, a fire analysis is also performed for undamaged structures and before the occurrence of earthquake. The results indicate that the vulnerability of structures increases dramatically when a previously damaged structure is exposed to PEF. The results also show that the damaging effects of post-earthquake fire are exacerbated when initiated from the second and third floor. Whilst the investigation is made for a certain class of structures (conventional buildings, intermediate reinforced structure, 3 stories), the results confirm the need for the incorporation of post-earthquake fire into the process of analysis and design, and provides some quantitative measures on the level of associated effects.

DETERMINATION OF GPS HEIGHT WITH INCORPORATION OF USING SURFACE METEOROLOGICAL MEASUREMENTS

  • Wang, Chuan-Sheng;Liou, Yuei-An;Yeh, Ta-Kang
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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    • pp.313-316
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    • 2008
  • Although the positioning accuracy of the Global Positioning System (GPS) has been studied extensively and used widely, it is still limited due to errors from sources such as the ionospheric effect, orbital uncertainty, antenna phase center variation, signal multipath and tropospheric influence. This investigation addresses the tropospheric effect on GPS height determination. Data obtained from GPS receivers and co-located surface meteorological instruments in 2003 are adopted in this study. The Ministry of the Interior (MOl), Taiwan, established these GPS receivers as continuous operating reference stations. Two different approaches, parameter estimation and external correction, are utilized to correct the zenith tropospheric delay (ZTD) by applying the surface meteorological measurements (SMM) data. Yet, incorrect pressure measurement leads to very poor accuracy. The GPS height can be affected by a few meters, and the root-mean-square (rms) of the daily solution ranges from a few millimeters to centimeters, no matter what the approach adopted. The effect is least obvious when using SMM data for the parameter estimation approach, but the constant corrections of the GPS height occur more often at higher altitudes. As for the external correction approach, the Saastamoinen model with SMM data makes the repeatability of the GPS height maintained at few centimeters, while the rms of the daily solution displays an improvement of about 2-3 mm.

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고해상도 카메라와의 동시 운영을 통한 드론 다분광카메라의 외부표정 및 영상 위치 정밀도 개선 연구 (Improving Precision of the Exterior Orientation and the Pixel Position of a Multispectral Camera onboard a Drone through the Simultaneous Utilization of a High Resolution Camera)

  • 백승일;변민수;김원국
    • 한국측량학회지
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    • 제39권6호
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    • pp.541-548
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    • 2021
  • 최근 농업, 산림관리, 해안환경 모니터링 등 다양한 분야에서 다분광 카메라의 활용, 특히 드론에 탑재되어 활용되는 사례가 증대되고 있다. 산출되는 다분광 영상은 위치정보를 위해 주로 드론에 탑재된 GPS (Global Positioning System)나 IMU (Inertial Measurement Unit) 센서를 이용해 지리참조(georeferencing)되는데, 보다 높은 정확도를 위해서는 직접 측량한 지상 기준점을 이용하기도 한다. 하지만, 직접 측량에 드는 비용 및 시간으로 인해 또는 직접 접근이 어려운 지역에 대해서는 지상 참조값을 활용하지 않고 지리참조를 수행해야하는 경우가 자주 발생하게 된다. 본 연구는 지상기준점이 가용하지 않은 경우에 다분광카메라로부터의 영상의 지리참조 정밀도를 향상시키기 위해 같이 탑재된 고해상도 RGB카메라의 영상을 활용하는 방안에 대하여 연구한다. 드론 영상은 우선 번들조정을 통해 카메라의 외부표정 요소를 추정하였고, 이를 지상 기준점을 이용한 경우의 외부표정 및 위치결과와 비교하였다. 실험결과, 고해상도 영상을 포함하여 번들조정을 하게 될 경우, 다분광 카메라 영상을 단독으로 활용할 때보다, 다분광 카메라 영상의 지리참조 오차가 비약적으로 감소하였음을 확인하였다. 추가로 한 지상 지점에서 드론으로의 방향각을 추정할 때의 오차를 분석한 결과, 마찬가지로 고해상도 RGB영상을 포함하여 번들조정하게 되면 기존의 방향각 오차가 한 단위이상 감소하는 것으로 나타났다.

Electrical resistivity and capillarity of self-compacting concrete with incorporation of fly ash and limestone filler

  • Silva, Pedro;de Brito, Jorge
    • Advances in concrete construction
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    • 제1권1호
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    • pp.65-84
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    • 2013
  • Electrical resistivity is a property associated with both the physical and chemical characteristics of concrete. It allows the evaluation of the greater or lesser difficulty with which aggressive substances penetrate the concrete's core before the dissolution of the passive film process and the consequent reinforcement's corrosion begin. This work addresses the capillary absorption of self-compacting concrete (SCC) with various types and contents of additions, correlating it with its electrical resistivity. To that effect, binary and ternary mixes of SCC were produced using fly ashes (FA) and limestone filler (LF). A total of 11 self-compactable mixes were produced: one with cement (C) only; three with C + FA in 30%, 60% and 70% substitution ratios; three with C + LF in 30%, 60% and 70% substitution ratios; four with C + FA + LF in combinations of 10-20%, 20-10%, 20-40% and 40-20% substitution ratios, respectively; and four reference mixes according to the LNEC E 464 specification, which refers to the NP EN 206-1 norm. The evaluation of the capillarity of the mixes produced was made through the determination of the water absorption by capillarity coefficient according to the LNEC E 393 specification. The electrical resistivity was evaluated using the European norm proposal presented by the EU-Project CHLORTEST (EU funded research Project under 5FP GROWTH programme) and based on the RILEM TC-154 EMC technical recommendation. The results indicate that SCC's capillarity is strongly conditioned by the type and quantity of the additions used. It was found that FA addition significantly improves some of the properties studied especially at older ages.

Investigating the Effect of Prior Damage on the Post-earthquake Fire Resistance of Reinforced Concrete Portal Frames

  • Ronagh, Hamid Reza;Behnam, Behrouz
    • International Journal of Concrete Structures and Materials
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    • 제6권4호
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    • pp.209-220
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    • 2012
  • Post-earthquake fire (PEF) can lead to a rapid collapse of buildings that have been partially damaged as a result of a prior earthquake. Almost all standards and codes for the design of structures against earthquake ignore the risk of PEF, and thus buildings designed using those codes could be too weak when subjected to a fire after an earthquake. An investigation based on sequential analysis inspired by FEMA356 is performed here on the immediate occupancy (IO), life safety (LS) and collapse prevention (CP) performance levels of two portal frames, after they are pushed to arrive at a certain level of displacement corresponding to the mentioned performance level. This investigation is followed by a fire analysis of the damaged frames, examining the time taken for the damaged frames to collapse. As a point of reference, a fire analysis is also performed for undamaged frames and before the occurrence of earthquake. The results indicate that while there is minor difference between the fire resistances of the fire-alone situation and the frames pushed to the IO level of performance, a notable difference is observed between the fire-alone analysis and the frames pushed to arrive at LS and CP levels of performance and exposed to PEF. The results also show that exposing only the beams to fire results in a higher decline of the fire resistance, compared to exposing only the columns to fire. Furthermore, the results show that the frames pushed to arrive at LS and CP levels of performance collapse in a global collapse mode laterally, whereas at the IO level of performance and fire-alone situation, the collapse mechanism is mostly local through the collapse of beams. Whilst the investigation is conducted for a certain class of portal frames, the results confirm the need for the incorporation of PEF into the process of analysis and design, and provide some quantitative measures on the level of associated effects.

효모세포의 당과 아미노산의 운반에 관한 연구 -I. 생장시기와 포자형성기의 포도당 운반- (Sugar and Amino Acid Transport in Yeast I. Glucose Transport during the Sporulation Stage with Reference to the Vegetative Stage.)

  • 민경희;권영명
    • 미생물학회지
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    • 제16권3호
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    • pp.122-130
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    • 1978
  • Saccharomyces cerevisiae J170, matant를 사용하여 YEP 배지에서 20시간 진탕 배양하여 생장이 왕성한 영양시기의 효모세포를 얻었다. 이 세포를 sporulation medium에 접종하여 $30^{\circ}C$에서 20시간 진탕 배양하면 약 80%의 ascospore를 형성함을 볼 수 있었다. 포자행성시기와 생장시기를 택하여 D-$^{14}C$-glucose 운반에 관하여 바교 검도한 결과는 다음파 같다. haploid인 포자형성시나 diploid인 생장시기의 포도당 흡수는 pH6.0에서 최대이었다. 이 두 시기의 포도당 운반은 2, 4-dinitrophenol에 의하여 저해되었으므로 포자형성기의 포도당운반도 역시 egergy를 요구하는 능동수송파 연관이 있음을 알게 되었다. 생장시기의 포도당 흡수정도는 포자형성기 보다 높았으며 이때에 fructose나 galactose와 포도당흡수의 관계는 서로 경쟁적으로 작용함을 알 수 있었다. 효모세포의 당 성분은 ribose, mannose, $\alpha$, $\beta$-glucose로 되어 있으며 특히 포자형성기의 mannose 함량은 영양세포 때보다 현저히 적었다.

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산화 알루미늄 및 냉각거울 노점계의 온도 의존성에 관한 연구 (The Effect of Temperature on Aluminum Oxide and Chilled Mirror Dew-point Hygrometers)

  • 김종철;최병일;우상봉;김용규;이상욱
    • 센서학회지
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    • 제26권1호
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    • pp.50-55
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    • 2017
  • The measurement of absolute humidity of gases is essential in many industries. The effect of temperature on aluminum oxide and chilled mirror dew-point hygrometers is investigated. The temperature of laboratory, pipe line, and sensor is varied and the dew point is measured by two different aluminum oxide hygrometers. In all cases, the dew point of hygrometers is increased as the temperature is elevated. The reason behind this observation is due to desorption of water from the inside of pipe line and/or sensor surroundings at elevated temperature that result in the increase of the absolute humidity. Moreover, the sensor itself shows a certain degree of temperature dependency in sensing the humidity especially at low temperature. It is also studied that chilled mirror dew-point hygrometer may indicate a higher dew point than the reference at high temperature because the cooling capability of mirror is decreased at high temperature. Our study will provide evidences in the incorporation of the temperature effect as uncertainty factors in the standard calibration procedure for dew point hygrometers.

Enhanced electrocapacitive performance and high power density of polypyrrole/graphene oxide nanocomposites prepared at reduced temperature

  • Mudila, Harish;Joshi, Varsha;Rana, Sweta;Zaidi, Mohmd. Ghulam Haider;Alam, Sarfaraz
    • Carbon letters
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    • 제15권3호
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    • pp.171-179
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    • 2014
  • An attempt was made to investigate the effect of the preparation temperature on the electrocapacitive performance of polypyrrole (PPY)/graphene oxide (GO) nanocomposites (PNCs). For this purpose, a series of PNCs were prepared at various temperatures by the cetyltrimethylammonium bromide-assisted dilute-solution polymerization of pyrrole in presence of GO (wt%) ranging from 1.0 to 4.0 with ferric chloride as an oxidant. The formation of the PNCs was ascertained through Fourier-transform infrared spectrometry, X-ray diffraction spectra, scanning electron microscopy and simultaneous thermogravimetric-differential scanning calorimetry. The electrocapacitive performance of the electrodes derived from sulphonated polysulphone-bound PNCs was evaluated through cyclic voltammetry with reference to Ag/AgCl at a scan rate (V/s) ranging from 0.2 and 0.001 in potassium hydroxide (1.0 M). The incorporation of GO into the PPY matrix at a reduced temperature has a pronounced effect on the electrocapacitive performance of PNCs. Under identical scan rates (0.001 V/s), PNCs prepared at $10{\pm}1^{\circ}C$ render improved specific conductivity (526.33 F/g) and power density (731.19 W/Kg) values compared to those prepared at $30{\pm}1^{\circ}C$ (217.69 F/g, 279.43 W/Kg). PNCs prepared at $10{\pm}1^{\circ}C$ rendered a capacitive retention rate of ~96% during the first 500 cycles. This indicates the excellent cyclic stability of the PNCs prepared at reduced temperatures for supercapacitor applications.

전략환경영향평가와 지속가능한 발전 지표의 연계방안 (Implication Measures between Strategic Environmental Impact Assessment and Sustainable Development Indicators)

  • 홍상표
    • 환경영향평가
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    • 제25권1호
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    • pp.63-76
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    • 2016
  • 2015년 9월에 세계 각국의 정상이 UN 총회에 모여 지속가능한 발전을 위한 2030 Agenda를 구축하기로 합의하였다. 2030 Agenda에는 사회적 안전성, 경제적 효율성 및 환경적 건전성이라는 3대축을 달성하기 위한 17개의 지속가능한 발전목표(SDG)가 채택되었다. UN 지속가능 발전 구축연합(UN SDSN)에서는 SDG 실행 정도를 측정하기 위한 지속가능 발전지표(SDI)를 개발하여 빈곤퇴치, 사회적 통합, 환경관리 같은 총체적 접근을 통하여 지속가능성의 달성 정도를 확인할 수 있는 지속가능성평가(SA)에 적용할 수 있도록 하였다. 우리나라에서는 전략환경영향평가(SEIA)를 PPP(정책, 계획, 프로그램)에 환경부가 시행하는 반면에, 전략환경평가(SEA)의 일종인 국토계획평가(NLPA)는 국토교통부 자체의 계획에 적용되고 있다. SEIA와 NLPA가 고위 정책당국자를 포함한 이해당사자들에게 의사결정 지원도구로 활용되어 왔지만, 이들 SEA 제도의 핵심원리인 최적 대안 선정의 평가기준은 구체성이 미흡한 실정이다. 우리나라 실정에 적합하게 고안된 SDI를 SEIA에 반영하면 지속가능성을 비교적 간략하게 평가하여 SDG 실행의 실효성을 향상시키는데 기여할 수 있을 것으로 판단된다.

GK2A AMI를 이용한 한반도 식생건강지수 산출 (Retrieval of Vegetation Health Index for the Korean Peninsula Using GK2A AMI)

  • 이수진;조재일;류재현;김나리;김광진;손은하;박기홍;장재철;이양원
    • 대한원격탐사학회지
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    • 제38권2호
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    • pp.179-188
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    • 2022
  • 지구온난화는 기후변화를 야기하며 전지구적으로 이상기상 현상을 유발하고 있다. 우리나라에서도 폭염, 가뭄과 같은 이상기상 현상이 증가하고 있는 상황이다. 이상기상 감시를 위하여 지표면온도(Land Surface Temperature, LST), 온도상태지수(Temperature Condition Index, TCI), 식생활력지수(Normalized Difference Vegetation Index, NDVI), 식생상태지수(Vegetation Condition Index, VCI), 식생건강지수(Vegetation Health Index, VHI) 등의 위성자료가 활용되고 있다. TCI와 VCI를 이용하여 계산되는 VHI는 온도, 강수와 같은 기상 요인에 의한 식생 스트레스를 나타내며, 기후변화 상황에서 가뭄 평가에 주로 활용되고 있다. TCI, VCI는 날짜 및 장소에 따른 LST, NDVI의 과거 평년치를 참조해서 산출되기 때문에, 아직 2년여의 자료밖에 없는 천리안위성 2A호(GK2A) AMI (Advanced Meteorological Imager) 자료로부터 TCI, VCI, VHI를 산출하는 것은 현재로서는 쉽지 않은 일이다. 본 연구에서는 대안적인 방법으로 VIIRS (Visible Infrared Imaging Radiometer Suite) 센서의 LST, NDVI를 이용하여 GK2A의 VHI 산출 가능성을 모색하였다. GK2A와 VIIRS의 LST, NDVI는 상당히 높은 상관성을 보이기 때문에, GK2A에 존재하지 않는 과거 평년치를 VIIRS 자료로 대체하는 방식을 택하였다. 8일 간격으로 GK2A 격자에 해당하는 LST, NDVI의 최소·최대값 조견표를 구축하여 TCI, VCI, VHI를 산출하였고, 최근 우리나라 이상기상 현상에 대한 해석을 수행하였다. GK2A VHI는 2020년 3월과 6월의 폭염, 4월과 7월의 저온, 8월의 폭우 등으로 인한 식생 스트레스의 변화를 잘 표현하는 것으로 나타났지만, 미국 해양대기청(National Oceanic and Atmospheric Administration, NOAA)의 VHI 산출물은 그렇지 않았다. 본 연구에서 제시한 GK2A VHI는 향후 LST, NDVI의 과거 평년치에 대한 통계적으로 엄밀한 보완을 거친다면 폭염, 가뭄으로 인한 식생 스트레스 감시에 활용될 수 있을 것으로 사료된다.