A simplified procedure to estimate peak drift demands for mid-rise steel and R/C frames under narrow-band motions in terms of the spectral-shape-based intensity measure I

2017 ◽  
Vol 150 ◽  
pp. 334-345 ◽  
Author(s):  
Edén Bojórquez ◽  
Victor Baca ◽  
Juan Bojórquez ◽  
Alfredo Reyes-Salazar ◽  
Robespierre Chávez ◽  
...  
Keyword(s):  
Narrow Band ◽  
Spectral Shape ◽  
Intensity Measure ◽  
Simplified Procedure

On the Use of Vector-Valued Intensity Measure to Predict Peak and Cumulative Demands of Steel Frames under Narrow-Band Motions

2014 ◽  
Vol 595 ◽  
pp. 137-142 ◽  
Author(s):  
Edén Bojórquez ◽  
Alfredo Reyes-Salazar ◽  
Sonia E. Ruiz
Keyword(s):  
Narrow Band ◽  
Ground Motions ◽  
Steel Frames ◽  
Spectral Shape ◽  
Intensity Measure ◽  
Intensity Measures ◽  
Energy Demands ◽  
Long Duration ◽  
Story Drift ◽  
Vector Valued

In this study, various alternative vector-valued ground motion intensity measures (IMs) are used to estimate maximum inter-story drifts and hysteretic energy demands of steel framed buildings under long duration narrow-band ground motions. The vectors are based on the spectral acceleration at first mode of the structure as first parameterSa (T1). As the second parameter of the vector,IMsrelated to peak, integral and spectral shape parameters are selected. It is concluded that spectral-shape-based vector-valuedIMshave the best relation with maximum inter-story drift and energy demands in steel frames subjected to narrow-band earthquake ground motions.

Parametric Rainflow Fatigue Damage for Some Power Spectra of Common Use

2010 ◽  
Author(s):  
Michel Olagnon ◽  
Zakoua Gue´de´
Keyword(s):  
Fatigue Damage ◽  
Shape Parameter ◽  
Narrow Band ◽  
Power Spectra ◽  
Spectral Shape ◽  
Damage Reduction ◽  
The Family ◽  
Rainflow Counting ◽  
Semi Empirical ◽  
Irregular Loading

Rainflow counting is widely accepted as the method that is most suited to analysis of fatigue damage of materials submitted to irregular loading. Formulas such as the Wirsching-Light and the Dirlik one allow to take into account spectral shape and bandwidth in an empirical or semi-empirical manner to obtain a best estimate damage reduction of the rainflow counting with respect to the narrow-band approximation. However, if one considers parametric shape families of common use for the spectra, a more straightforward way is to make damage depend on the shape parameter of the family rather than on the spectral moments. We provide here such semi-empirical parametric formulas for the Jonswap, Wallops, Triangle and Power-tail families. In addition, the ICA formula allows us to extend the above formulas to the well-known bimodal spectral shape proposed by Ochi-Hubble.

Ductility-dependent intensity measure that accounts for ground-motion spectral shape and duration

2015 ◽  
Vol 45 (4) ◽  
pp. 653-672 ◽  
Author(s):  
Nasser A. Marafi ◽  
Jeffrey W. Berman ◽  
Marc O. Eberhard
Keyword(s):  
Ground Motion ◽  
Spectral Shape ◽  
Intensity Measure

Spectral shape discrimination of narrow‐band sounds

1992 ◽  
Vol 92 (5) ◽  
pp. 2586-2597 ◽  
Author(s):  
David M. Green ◽  
Bruce G. Berg ◽  
Huanping Dai ◽  
David A. Eddins ◽  
Zekiye Onsan ◽  
...  
Keyword(s):  
Narrow Band ◽  
Spectral Shape ◽  
Shape Discrimination

scholarly journals Spectral shape discrimination of narrow‐band spectra

1991 ◽  
Vol 89 (4B) ◽  
pp. 1911-1911 ◽  
Author(s):  
Bruce G. Berg ◽  
David M. Green
Keyword(s):  
Narrow Band ◽  
Spectral Shape ◽  
Shape Discrimination ◽  
Band Spectra

Dielectric Function of “Narrow” Band Gap InN

2002 ◽  
Vol 743 ◽  
Author(s):  
R. Goldhahn ◽  
S. Shokhovets ◽  
V. Cimalla ◽  
L. Spiess ◽  
G. Ecke ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Band Gap ◽  
Dielectric Function ◽  
First Principles ◽  
Molecular Beam ◽  
Narrow Band ◽  
Spectral Shape ◽  
Strong Increase ◽  
Sapphire Substrates ◽  
Ingan Alloys

ABSTRACTSpectroscopic ellipsometry studies in the energy range from 0.7 up to 5.5 eV were carried out in order to determine the dielectric function (DF) of ‘narrow’ band gap (< 1 eV) single-crystalline InN films grown by molecular beam epitaxy on sapphire substrates. The imaginary part of the DF is characterized by a strong increase immediately above the band gap and then by a nearly constant value up to 4 eV. Pronounced structures above 4 eV are attributed to transitions along the L-M direction in the Brillouin-zone as a comparison with first-principles calculations indicates. In contrast, sputtered layers (band gap ∼1.9 eV) studied for comparison show a completely different spectral shape of the DF. Finally, DF's of high In-content InGaN alloys are presented, providing further evidence that InN is a “narrow” band gap semiconductor.

Evaluating A New Proxy For Spectral Shape To Be Used As An Intensity Measure

2008 ◽  
Author(s):  
Eden Bojorquez ◽  
Iunio Iervolino ◽  
Gaetano Manfredi ◽  
Adolfo Santini ◽  
Nicola Moraci
Keyword(s):  
Spectral Shape ◽  
Intensity Measure

scholarly journals Comparing Hysteretic Energy and Ductility Uniform Annual Failure Rate Spectra for Traditional and a Spectral Shape-Based Intensity Measure

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Joel Carvajal ◽  
Edén Bojórquez ◽  
Sonia Ruiz ◽  
Juan Bojórquez ◽  
Alfredo Reyes-Salazar ◽  
...  
Keyword(s):  
Failure Rate ◽  
Structural Reliability ◽  
Soft Soil ◽  
Spectral Shape ◽  
Design Tool ◽  
Hysteretic Behavior ◽  
Intensity Measure ◽  
Traditional Use ◽  
Intensity Measures ◽  
Hysteretic Energy

In this study, with the objective to develop a reliability-based seismic design tool, ductility and dissipated hysteretic energy uniform annual failure rate (UAFR) spectra are obtained and compared using the spectral acceleration at first mode of vibration of the structure Sa(T1) and the well-known spectral shape-based intensity measure INp. Notice that this is the first time in the literature that UAFR spectra are obtained for the advanced spectral shape intensity measure INp. For this aim, 110 simulated ground motions recorded from the soft soil of Mexico City were selected due to their large energy amount demanded to the structures; moreover, four elastoplastic hysteretic behavior models are considered for the dynamic analyses with post-yielding stiffness of 0, 3, 5, and 10%. It is observed that the use of elasto-perfectly plastic models provided similar UAFR spectra in comparison with hysteretic models with different post-yielding stiffness. This conclusion is valid for the two selected intensity measures. In addition, the lateral resistance required to achieve similar structural reliability levels is larger when the INp intensity measure is used, especially for buildings with vibration periods equal or larger than the soil period, in such a way that the traditional use of Sa(T1) could provide structures with less structural reliability levels.

Statistical analysis of classification

1966 ◽  
Vol 24 ◽  
pp. 188-189
Author(s):  
T. J. Deeming
Keyword(s):  
Multivariate Analysis ◽  
Statistical Analysis ◽  
Classification Scheme ◽  
Analytical Procedure ◽  
Narrow Band ◽  
Scientific Research ◽  
Maximum Amount ◽  
Amount Of Information

If we make a set of measurements, such as narrow-band or multicolour photo-electric measurements, which are designed to improve a scheme of classification, and in particular if they are designed to extend the number of dimensions of classification, i.e. the number of classification parameters, then some important problems of analytical procedure arise. First, it is important not to reproduce the errors of the classification scheme which we are trying to improve. Second, when trying to extend the number of dimensions of classification we have little or nothing with which to test the validity of the new parameters.Problems similar to these have occurred in other areas of scientific research (notably psychology and education) and the branch of Statistics called Multivariate Analysis has been developed to deal with them. The techniques of this subject are largely unknown to astronomers, but, if carefully applied, they should at the very least ensure that the astronomer gets the maximum amount of information out of his data and does not waste his time looking for information which is not there. More optimistically, these techniques are potentially capable of indicating the number of classification parameters necessary and giving specific formulas for computing them, as well as pinpointing those particular measurements which are most crucial for determining the classification parameters.

Photo-electric Hβ and uvby photometry

1966 ◽  
Vol 24 ◽  
pp. 170-180
Author(s):  
D. L. Crawford
Keyword(s):  
Narrow Band ◽  
Line Strength ◽  
Interference Filter ◽  
B Stars ◽  
Relative Line ◽  
The Mean ◽  
F Stars ◽  
Two Parameters ◽  
Filter Photometry ◽  
The Continuum

Early in the 1950's Strömgren (1, 2, 3, 4, 5) introduced medium to narrow-band interference filter photometry at the McDonald Observatory. He used six interference filters to obtain two parameters of astrophysical interest. These parameters he calledlandc, for line and continuum hydrogen absorption. The first measured empirically the absorption line strength of Hβby means of a filter of half width 35Å centered on Hβand compared to the mean of two filters situated in the continuum near Hβ. The second index measured empirically the Balmer discontinuity by means of a filter situated below the Balmer discontinuity and two above it. He showed that these two indices could accurately predict the spectral type and luminosity of both B stars and A and F stars. He later derived (6) an indexmfrom the same filters. This index was a measure of the relative line blanketing near 4100Å compared to two filters above 4500Å. These three indices confirmed earlier work by many people, including Lindblad and Becker. References to this earlier work and to the systems discussed today can be found in Strömgren's article inBasic Astronomical Data(7).

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