Time-frequency decomposition of seismic signals via quantum swarm evolutionary matching pursuit     

Amir Semnani  Liang Wang  Mehdi Ostadhassan  Majid Nabi-Bidhendi  Babak Nadjar Araabi 《Geophysical Prospecting》2019,67(7):1701-1719

Matching pursuit belongs to the category of spectral decomposition approaches that use a pre-defined discrete wavelet dictionary in order to decompose a signal adaptively. Although disengaged from windowing issues, matching point demands high computational costs as extraction of all local structure of signal requires a large size dictionary. Thus in order to find the best match wavelet, it is required to search the whole space. To reduce the computational cost of greedy matching pursuit, two artificial intelligence methods, (1) quantum inspired evolutionary algorithm and (2) particle swarm optimization, are introduced for two successive steps: (a) initial estimation and (b) optimization of wavelet parameters. We call this algorithm quantum swarm evolutionary matching pursuit. Quantum swarm evolutionary matching pursuit starts with a small colony of population at which each individual, is potentially a transformed form of a time-frequency atom. To attain maximum pursuit of the potential candidate wavelets with the residual, the colony members are adjusted in an evolutionary way. In addition, the quantum computing concepts such as quantum bit, quantum gate, and superposition of states are introduced into the method. The algorithm parameters such as social and cognitive learning factors, population size and global migration period are optimized using seismic signals. In applying matching pursuit to geophysical data, typically complex trace attributes are used for initial estimation of wavelet parameters, however, in this study it was shown that using complex trace attributes are sensitive to noisy data and would have lower rate of convergence. The algorithm performance over noisy signals, using non-orthogonal dictionaries are investigated and compared with other methods such as orthogonal matching pursuit. The results illustrate that quantum swarm evolutionary matching pursuit has the least sensitivity to noise and higher rate of convergence. Finally, the algorithm is applied to both modelled seismograms and real data for detection of low frequency anomalies to validate the findings.  相似文献   

Assessment of geomorphological bank evolution of the alluvial threshold rivers based on entropy concept parameters     

Azadeh Gholami  Majid Mohammadian  Amir Hossein Zaji  Bahram Gharabaghi 《水文科学杂志》2019,64(7):856-872

The complex stream bank profiles in alluvial channels and rivers that are formed after reaching equilibrium has been a popular topic of research for many geomorphologists and river engineers. The entropy theory has recently been successfully applied to this problem. However, the existing methods restrict the further application of the entropy parameter to determine the cross-section slope of the river banks. To solve this limitation, we introduce a novel approach in the extraction of the equation based on the calculation of the entropy parameter (λ) and the transverse slope of the bank profile at threshold channel conditions. The effects of different hydraulic and geometric parameters are evaluated on a variation of the entropy parameter. Sensitivity analysis on the parameters affecting the entropy parameter shows that the most effective parameter on the λ-slope multiplier is the maximum slope of the bank profile and the dimensionless lateral distance of the river banks.  相似文献   

Boundary Condition Nomenclature Confusion in Groundwater Flow Modeling     

Amir Jazayeri  Adrian D. Werner 《Ground water》2019,57(5):664-668

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Latitudinal and Longitudinal Variations of Earth’s Magnetic Force on Electrified Hydrometeors     

Sadeghi  Babak  Taghavi  Farahnaz  Akmal  Amir Abbas Shayegani 《Geomagnetism and Aeronomy》2019,59(6):770-781

Geomagnetism and Aeronomy - In this study, a hypothesis is proposed about the possible effect of Geomagnetic field (GMF) on the charge structure of a thundercloud based on Lorentz force equation...  相似文献   

Erratum to: Analysis of landslide causes and associated damages in the Kashmir Himalayas of Pakistan     

Atta-Ur-Rahman  Amir Nawaz Khan  Andrew E. Collins 《Natural Hazards》2014,74(2):1307-1307

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Incorporation of chitosan and glass substrate for improvement in adsorption,separation, and stability of TiO<Subscript>2</Subscript> photodegradation     

M. N. I. Amir  N. M. Julkapli  S. B. Abd Hamid 《International Journal of Environmental Science and Technology》2016,13(3):865-874

It is demonstrated that single titanium dioxide (TiO₂) has high potential for photodegradation of pollutants. However, it is still far from becoming an effective photocatalyst system, due to issues of adsorption process, separation, as well as dissolution. Therefore, this study highlights the high adsorption capacity, simplified separation, and the promising stability of TiO_2(SY) (synthesized via sol–gel method) photocatalyst, fabricated using chitosan–TiO_2(SY) and supported by glass substrate (Cs–TiO_2(SY)/glass substrate) photocatalysts. Chitosan (Cs), with abundant –R–NH and NH₂ groups, promotes the adsorption sites of methyl orange (MO) and OH groups for major attachment to TiO_2(SY). Meanwhile, the glass substrate increases stability and assists separation of the photocatalysts. Initially, nano-TiO_2(SY) has been characterized using high-resolution transmission electron microscope. Cs–TiO_2(SY)/glass substrate was fabricated via dip-coating. The distribution and interface between the photocatalytic components were characterized by Fourier transform infrared absorption spectroscopy, UV–Vis diffuse reflectance spectroscopy, field emission scanning electron microscopy, and energy-dispersive spectrometer. UV–Vis analysis of the multilayer photocatalyst (2, 4, 6, and 8 layers) was further carried out by the adsorption–photodegradation, with MO as model of pollutant. Seventy percent of the total removal of MO via optimized eight layers of photocatalyst was achieved within 1 h of UV irradiation. The adsorption photocatalyst achieved 50 % with no exposure to UV light for 15 min of irradiation. It is concluded that suitable photocatalytic conditions and sample parameters possessing the multilayer photocatalyst of Cs–TiO_2(SY) are beneficial toward the adsorption–photodegradation process in wastewater treatment.  相似文献   

Erratum to: Investigation of the atmospheric mesoscale circulation patterns and their simulation with WRF-CHEM model of the dust storm occurrence over the southern coast of the Caspian Sea     

Sammaneh Negah  Amir Hussain Meshkatee  Sohrab Hajjam  Ali Kamali 《Arabian Journal of Geosciences》2016,9(17):693

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Role of construction of large dams on river morphology (case study: the Karkheh dam in Iran)     

Arash Adib  Hesam Foladfar  Amir Roozy 《Arabian Journal of Geosciences》2016,9(15):661

Unfortunately in developing countries, human activities without attention to the environmental aspects damage to nature. For example, construction of large dams dries wetlands in southwest of Iran. Also, construction of dams is a very important factor for morphological changes. The case study of this research is downstream of the Karkheh dam. This dam is the largest Earth dam in Iran and locates in southwest of Iran. It was constructed in 1999. Small sinuosity coefficient of zone near to dam has been illustrated by satellite images in 2002 and 2014. This subject shows instability of this part of reach; also, the results of Shulits equation illustrate that this part is instable. But, increasing of morphological characteristics (sinuosity coefficient, central angle, and relative radius) show that stability of this reach is increasing. Surveying confirm this matter and shows that severe erosion in upstream and sedimentation in downstream of reach is finishing. Also, it is observed that flow discharge reduced (?56 %) after construction of dam and average width of river reduced (?21 %) from 2002 to 2014. In the early years after the construction of the dam, sediment discharge reduced considerably (?14 %) from Pay-e-Pol to Abdol Khan hydrometric stations. Increasing of morphological characteristics (especially at zones near to dam) and decreasing changes of bed level (sedimentation and erosion) prove that effects of dam are overcoming on effects of other factors, and these effects are permanent in long term.  相似文献   

Temperature-based estimation of global solar radiation using soft computing methodologies     

Kasra Mohammadi  Shahaboddin Shamshirband  Amir Seyed Danesh  Mohd Shahidan Abdullah  Mazdak Zamani 《Theoretical and Applied Climatology》2016,125(1-2):101-112

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Theory-guided machine learning to predict density evolution of sand dynamically compacted under Ko condition     

Tophel  Amir  Walker  Jeffrey P.  Dutta  Troyee Tanu  Kodikara  Jayantha 《Acta Geotechnica》2022,17(8):3479-3497

Acta Geotechnica - This paper introduces a theory-guided machine learning (TGML) framework, which combines a theoretical model (TM) and a machine learning (ML) algorithm to predict compaction...  相似文献