• 제목/요약/키워드: Velocity Correlation

검색결과 1,145건 처리시간 0.029초

Damage potential of earthquake records for RC building stock

  • Ozmen, Hayri Baytan;Inel, Mehmet
    • Earthquakes and Structures
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    • 제10권6호
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    • pp.1315-1330
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    • 2016
  • This study investigates ground motion parameters and their damage potential for building type structures. It focuses on low and mid-rise reinforced concrete buildings that are important portion of the existing building stock under seismic risk in many countries. Correlations of 19 parameters of 466 earthquake records with nonlinear displacement demands of 1056 Single Degree of Freedom (SDOF) systems are investigated. Properties of SDOF systems are established to represent RC building construction practice. The correlation of damage and ground motion characteristics is examined with respect to number of story and site classes. Equations for average nonlinear displacement demands of considered RC buildings are given for some of the ground motion parameters. Velocity related parameters are generally found to have better results than the acceleration, displacement and frequency related ones. Correlation of the parameters may be expected to decrease with increasing intensity of seismic event. Velocity Spectrum Intensity and Peak Ground Velocity have been found to have the highest correlation values for almost all site classes and number of story groups. Common parameter of Peak Ground Acceleration has lower correlation with damage when compared to them and some other parameters like Effective Design Acceleration and Characteristic Intensity.

Estimating Correlation Dimensions of Land-Sea Breeze Phenomenon

  • Lee, Hwa-Woon;Kim, Yoo-Keun;Lee, Young-Gon
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • 제3권2호
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    • pp.81-89
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    • 1999
  • This study estimates the correlation dimensions of the land-sea breeze phenomenon, that has a clear diurnal cycle, in order to gain a more detailed understanding of this phenomenon. The data adopted include north-south wind velocity component(v) and temperature(T) time series that were observed at Kimhae Airport and Inje University over a period of 5 days, from the 4th to the 8th of August, 1994. The embedding phase space of the time series were reconstructed from 2 to 14 dimensions, and the correlation dimensions of the attractors were then estimated. The results show that the land-sea breeze phenomenon exhibits a deterministic chaos with non-integer correlation dimension values between 2 and 3. Accordingly, 3 is the minimum number of independent variables required to model the dynamics of the landsea breeze phenomenon in the Kimhae area. Since the saturated embedding dimension, when the correlation dimension remains unchanged, is larger for the wind velocity v-component than for temperature, this indicates that wind velocity is susceptible to topology.

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국가대표 소프트볼선수들의 흡기능력과 골밀도 및 골 질량 그리고 체간의 근력 및 근지구력의 상관관계 분석 (Analysis of correlation between the inspiratory capacity of the National softball players and the bone density, bon mass, muscle power, muscle endurance)

  • 김현철;박기준
    • 대한물리의학회지
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    • 제15권1호
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    • pp.95-104
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    • 2020
  • PURPOSE: A prospective study was conducted to investigate the correlation between the inspiration ability, bone mineral density, lumbar muscle strength, and muscular endurance for the national softball athletes in the national training center. METHODS: The general characteristics of study subjects, inspiration ability, bone mineral density, muscle strength, and muscular endurance data were analyzed using descriptive statistics. In addition, the Pearson product moment correlation was performed to investigate the correlation between the inspiratory capacity, bone mineral density, muscle strength, and muscular endurance. RESULTS: The inspiration, flow rates, and volume were not correlated with the bone mass and bone mineral density. Inspiration and the flow rates and volume were not correlated with the bone mass and bone mineral density. On the other hand, inspiration was correlated with the Extensor muscles (r=.464, p=.006) at an angular velocity of 60°/s and the flexors (r=.463, p=.006) and extensor muscles (r=.615, p<.001) at an angular velocity of 180°/s. The flow rate was also correlated with the extensor muscles (r=.444, p=.009) at an angular velocity of 60°/s and with flexor muscles (r=.432, p=.011) and extensor muscles (r=.589, p<.001) at an angular velocity of 180°/s. Finally, the volume was correlated at the extensor muscles at an angular velocity of 180°/s (r=.534, p=.001). CONCLUSION: The correlation between the inspiratory capacity, bone mineral density, muscle strength, and muscular endurance of softball athletes did not correlate with the bone mass and bone density. On the other hand, the lumbar muscle strength increased with increasing inspiratory capacity.

충청지역 지층별 전단파속도와 N값의 상관관계 분석 (Analysis on Relation of S-wave Velocity and N Value for Stratums in Chungcheong Buk-do)

  • 도종남;황필재;정성래;천병식
    • 한국지반환경공학회 논문집
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    • 제12권10호
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    • pp.13-22
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    • 2011
  • 본 연구는 충청 지역에서 측정된 전단파 속도를 지층별로 점성토층, 사질토층, 자갈층, 풍화토층, 풍화암층으로 분류하여 표준관입시험 N값과 전단파 속도의 상관관계식을 제안하였으며, 참고적으로 풍화암층을 제외한 전체토층의 상관관계식을 도출하였다. 제안된 상관관계식은 국내외 기존 제안식을 고려하여 모두 멱함수로 산정하였으며 지반강도의 경우 N값이 50 이상일 경우에는 선형으로 환산하여 적용하였다. 금번 연구에서 제안한 관계식을 국내외 사례와 지층별로 비교 분석한 결과 점성토층, 사질토층, 자갈층, 풍화토층의 경우에는 유사한 특성을 보이고 있음을 알 수 있었다. 다만, 풍화암층에 대한 상관관계식의 경우 국내 관계식과 다소 낮은 결과치를 나타내는 차이가 있음을 확인하였다. 풍화암층의 경우 상관관계식 산정에 있어 N값이 50 이상일 경우는 선형으로 환산하여 적용함에 따라 지반 강도가 높은 지층인 풍화암층에서 차이가 발생한 것으로 파악된다.

경두개 도플러 초음파의 측정지표와 성/연령의 상관성 (Correlation of Gender/Age and Measurement Indices of Transcranial Doppler Ultrasonography)

  • 진복희
    • 대한임상검사과학회지
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    • 제42권3호
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    • pp.155-160
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    • 2010
  • Transcranial Doppler ultrasonography (TCD) allows measurement of blood flow velocity to be made from the basal intracerebral vessels. Blood flow velocity in TCD is highly affected not only by blood vessel diameter, blood flow volume, blood viscosity, but also age and sex. Therefore, the study is focused on the correlation between TCD measurement index and sex/age. Subjects were 214 (male 147, famale 67) who had TCD for headache and stroke evaluations at Dongguk University Ilsan Hospital neurology department from December 2009 to April 2010. Sex did not show significant differences with mean flow velocity (MFV), peak systolic flow velocity (PSFV), end diastolic flow velocity (EDFV), pulsatility index (PI) and resistance index (RI) in middle cerebral artery (MCA). Although age also did not show significant differences with MFV and PSFV, EDFV has statistically decreased with age, and PI and RI has statistically increased with age. In addition, age showed significant correlation with MFV, EDFV, PI and RI, but not with PSFV. Therefore, TCD is definitely correlated with age and sex, so that those influencial factors must be considered when being tested.

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BF 방법을 이용한 EX Leo의 시선속도 추정 (RADIAL VELOCITY ESTIMATION OF EX Leo USING BF ALGORITHM)

  • 강동일;박홍서;한인우;김강민
    • 천문학논총
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    • 제22권2호
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    • pp.35-41
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    • 2007
  • We present the result of radial velocity observation of a W UMa type binary star EX Leo. We observed the star on February 16, 2003, using Long-Slit spectrograph of BOAO(Bohyunsan Optical Astronomical Observatory). Since the spectral lines are broad due to its fast rotation, it is difficult to distinguish two radial velocities from cross correlation function. Instead of cross correlation function, we used broadening function to develop our own code which estimate the radial velocity of the broadened line spectra. With our own code, radial velocities of primary and secondary stars are derived simultaneously. From the radial velocity curve fit, we obtained $K_1=50.24{\pm}8.29km/s$ and $K_2=254.05{\pm}20.984km/s$ respectively.

PIV를 이용한 터빈펌프의 동${\cdot}$정익 속도장 계측 (Measurement of the Velocity field of Rotor-Stator in a Centrifugal Turbine Pump by Using PIV)

  • 임유청;서민식;이영호
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 1998년도 유체기계 연구개발 발표회 논문집
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    • pp.11-18
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    • 1998
  • The present experimental study is focused on the application of multi-point simultaneous measurement by PIV(Particle Image Velocimetry) to rotor-stator region within centrifugal turbine pump. Six different kinds of rpm(120, 500, 1000, 1500, 2000 and 2500) are selected as experimental condition. Optimized cross correlation identification to obtain velocity vectors is implemented by direct calculation of correlation coefficients. Fine optical setup deeply concerned with PIV performance is arranged for accurate PIV measurement of high-speed complex flow. The instantaneous and time-mean velocity distribution and velocity profile are represented quantitatively at the rotor and stator region.

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N값과 전단파 속도의 상관식 비교 (Comparison of Correlation Equations between N value and Shear Wave Velocity)

  • 공진영;채휘영;천병식
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 춘계 학술발표회
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    • pp.656-665
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    • 2010
  • Shear modulus has been recognized as one of the important soil properties in dynamic analysis of ground and can be calculated from in situ measurement of shear wave velocity. Field seismic tests are the most accurate but expensive methods to investigate dynamic ground characteristics. Due to that reason, empirical equations for estimating the shear wave velocity are widely used rather than conducting in-situ tests. The most common equations are based on the N value obtained in conjuctions with a standard penetration test. In this paper, the field datas of standard penetration test and suspension PS logging measured in 126 sites of Korea were summarized and the correlation equations between N value and shear wave velocity are suggested.

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수치계산을 이용한 LFG 혼합가스의 연소속도 상관식 도출 (A Suggestion for the Burning Velocity Correlation of LFG Mixed Gas Using Numerical Simulation)

  • 이창언;오창보;정익산;정영식
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집B
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    • pp.906-912
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    • 2000
  • In this study, for the use of LFG, the burning velocities of LFG and LFG mixed fuels have been numerically analyzed. C3 reaction mechanism which consists of 92 species and 621 reaction was adopted in the calculation. The results show that the burning velocities of LFG and LFG mixed fuels are obtained as a function of $CH_4$ and LFG percentage at stoichiometric conditions. In addition, the correlations of burning velocities LFG and LFG mixed fuels were obtained over a wide range of the equivalence ratio. The comparison of burning velocity correlated from numerically calculated results with experimental ones shows good agreements. From these results, the suggested burning velocity correlations far LFG and LFG mixed fuels in this study can be applied to the practical utilization of LFG.

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PIV를 이용한 터빈펌프의 동${\cdot}$정익 속도장 계측 (Measurement of the Velocity Field of Rotor-Stator in a Centrifugal Turbine Pump Using PIV)

  • 임유청;서민식;이영호
    • 한국유체기계학회 논문집
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    • 제2권1호
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    • pp.35-42
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    • 1999
  • The present experimental study is focused on the application of multi-point simultaneous measurement by PIV(Particle Image Velocimetry) to rotor-stater region within centrifugal turbine pump. Six different kinds of rpm(120, 500, 1000, 1500, 2000 and 2500) are selected as experimental condition. Optimized cross correlation identification to obtain velocity vectors is implemented with direct calculation of correlation coefficients. Fine optical setup concerned with PIV performance is arranged for the accurate PIV measurement of high-speed complex flow. The instantaneous and time-mean velocity distribution and velocity profile are represented quantitatively at the rotor and stator region.

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