Dispersion of Love-type wave and its limitation in a nonlocal elastic model of nonhomogeneous layer upon an orthotropic extended medium

In inversion of viscoelastic full-wavefield seismic data, the choice of model parameterization influences the uncertainties and biases in estimating seismic and petrophysical parameters. Using an incomplete model parameterization results in solutions in which the effects of missing parameters are attributed erroneously to the parameters that are included. Incompleteness in this context means assuming the earth is elastic rather than viscoelastic. The inclusion of compressional and shear-wave quality factors [Formula: see text] and [Formula: see text] in inversion gives better estimates of reservoir properties than the less complete (elastic) model parameterization. [Formula: see text] and [Formula: see text] are sensitive primarily to fluid types and saturations. The parameter correlations are sensitive also to the model parameterization. As noise increases in the viscoelastic input data, the resolution of the estimated parameters decreases, but the parameter correlations are relatively unaffected by modest noise levels.

Download Full-text

Evaluation of floor acceleration demands from the 2017 Mexico City code seismic provisions using a continuous elastic model and records of instrumented buildings

Earthquake Spectra ◽

10.1177/8755293020974692 ◽

2020 ◽

Vol 36 (2_suppl) ◽

pp. 213-237

Author(s):

Miguel A Jaimes ◽

Adrián D García-Soto

Keyword(s):

Mexico City ◽

Seismic Design ◽

Soft Soil ◽

Response Spectra ◽

Elastic Model ◽

Ground Acceleration ◽

Nonstructural Components ◽

Floor Response Spectra ◽

Instrumented Buildings ◽

Floor Acceleration

This study presents an evaluation of floor acceleration demands for the design of rigid and flexible acceleration-sensitive nonstructural components in buildings, calculated using the most recent Mexico City seismic design provisions, released in 2017. This evaluation includes two approaches: (1) a simplified continuous elastic model and (2) using recordings from 10 instrumented buildings located in Mexico City. The study found that peak floor elastic acceleration demands imposed on rigid nonstructural components into buildings situated in Mexico City might reach values of 4.8 and 6.4 times the peak ground acceleration at rock and soft sites, respectively. The peak elastic acceleration demands imposed on flexible nonstructural components in all floors, estimated using floor response spectra, might be four times larger than the maximum acceleration of the floor at the point of support of the component for buildings located in rock and soft soil. Comparison of results from the two approaches with the current seismic design provisions revealed that the peak acceleration demands and floor response spectra computed with the current 2017 Mexico City seismic design provisions are, in general, adequate.

Download Full-text

Holistic simulation of wind turbines with fully aero-elastic and electrical model

Forschung im Ingenieurwesen ◽

10.1007/s10010-021-00479-6 ◽

2021 ◽

Author(s):

Marcus Wiens ◽

Sebastian Frahm ◽

Philipp Thomas ◽

Shoaib Kahn

Keyword(s):

Renewable Energy ◽

Wind Turbine ◽

Wind Turbines ◽

Low Voltage ◽

Renewable Energy Sources ◽

Elastic Model ◽

Electrical Model ◽

Holistic Model ◽

Electric System ◽

Electrical Components

AbstractRequirements for the design of wind turbines advance facing the challenges of a high content of renewable energy sources in the public grid. A high percentage of renewable energy weaken the grid and grid faults become more likely, which add additional loads on the wind turbine. Load calculations with aero-elastic models are standard for the design of wind turbines. Components of the electric system are usually roughly modeled in aero-elastic models and therefore the effect of detailed electrical models on the load calculations is unclear. A holistic wind turbine model is obtained, by combining an aero-elastic model and detailed electrical model into one co-simulation. The holistic model, representing a DFIG turbine is compared to a standard aero-elastic model for load calculations. It is shown that a detailed modelling of the electrical components e.g., generator, converter, and grid, have an influence on the results of load calculations. An analysis of low-voltage-ride-trough events during turbulent wind shows massive increase of loads on the drive train and effects the tower loads. Furthermore, the presented holistic model could be used to investigate different control approaches on the wind turbine dynamics and loads. This approach is applicable to the modelling of a holistic wind park to investigate interaction on the electrical level and simultaneously evaluate the loads on the wind turbine.

Download Full-text

Dynamic pricing with demand disaggregation for hotel revenue management

Journal of Heuristics ◽

10.1007/s10732-021-09480-2 ◽

2021 ◽

Author(s):

Andrei M. Bandalouski ◽

Natalja G. Egorova ◽

Mikhail Y. Kovalyov ◽

Erwin Pesch ◽

S. Armagan Tarim

Keyword(s):

Dynamic Pricing ◽

Programming Model ◽

Computer Experiments ◽

Price Policy ◽

Linear Constraints ◽

Economic Consequences ◽

Elastic Model ◽

Computationally Efficient ◽

Data Set ◽

Dynamic Price

AbstractIn this paper we present a novel approach to the dynamic pricing problem for hotel businesses. It includes disaggregation of the demand into several categories, forecasting, elastic demand simulation, and a mathematical programming model with concave quadratic objective function and linear constraints for dynamic price optimization. The approach is computationally efficient and easy to implement. In computer experiments with a hotel data set, the hotel revenue is increased by about 6% on average in comparison with the actual revenue gained in a past period, where the fixed price policy was employed, subject to an assumption that the demand can deviate from the suggested elastic model. The approach and the developed software can be a useful tool for small hotels recovering from the economic consequences of the COVID-19 pandemic.

Download Full-text

Data processing in Software-type Wave–Particle Interaction Analyzer onboard the Arase satellite

Earth Planets and Space ◽

10.1186/s40623-018-0856-y ◽

2018 ◽

Vol 70 (1) ◽

Cited By ~ 11

Author(s):

Mitsuru Hikishima ◽

Hirotsugu Kojima ◽

Yuto Katoh ◽

Yoshiya Kasahara ◽

Satoshi Kasahara ◽

...

Keyword(s):

Data Processing ◽

Particle Interaction ◽

Wave Particle Interaction ◽

Type Wave

Download Full-text

Simultaneous observations of IPDP type wave events in the evening and morning hours

Planetary and Space Science ◽

10.1016/0032-0633(87)90044-4 ◽

1987 ◽

Vol 35 (6) ◽

pp. 827-832 ◽

Cited By ~ 2

Author(s):

J. Kangas ◽

T. Pikkarainen ◽

J.V. Olson

Keyword(s):

Type Wave

Download Full-text

A study of gate-type wave attenuators

PROCEEDINGS OF CIVIL ENGINEERING IN THE OCEAN ◽

10.2208/prooe.13.591 ◽

1997 ◽

Vol 13 ◽

pp. 591-596

Author(s):

Masaya Kato ◽

Masaru Murata ◽

Keiichi Tsukada ◽

Kenji Oda ◽

Hideaki Watarai

Keyword(s):

Type Wave

Download Full-text

PHASE-FIELD MODELING OF ELASTIC EFFECTS IN EUTECTIC GROWTH WITH MISFIT STRESSES

International Journal of Modeling Simulation and Scientific Computing ◽

10.1142/s1793962312500249 ◽

2012 ◽

Vol 04 (01) ◽

pp. 1250024

Author(s):

ZOHREH EBRAHIMI ◽

JOAO REZENDEH

Keyword(s):

Phase Field ◽

Elastic Energy ◽

Field Model ◽

Phase Field Model ◽

Solidification Process ◽

Eutectic Growth ◽

Point Of View ◽

Eutectic Solidification ◽

Elastic Model ◽

Sharp Interface Model

Elastic interactions, arising from a difference of lattice spacing between two coherent phases in eutectic alloys with misfit stresses, can have an influence on microstructural pattern formation of eutectic colonies during solidification process. From a thermodynamic point of view the elastic energy contributes to the free energy of the phases and modifies their mutual stability. Therefore, the elastic stresses will have an effect on stability of lamellae, lamellae spacing and growth modes. In this paper, a phase-field model is employed to investigate the influence of elastic misfits in eutectic growth. The model reduces to the traditional sharp-interface model in a thin-interface limit, where the microscopic interface width is small but finite. An elastic model is designed, based on linear microelasticity theory, to incorporate the elastic energy in the phase-field model. Theoretical and numerical approaches, required to model elastic effects, are formulated and the stress distributions in eutectic solidification structures are evaluated. The two-dimensional simulations are performed for directed eutectic growth and the simulation results for different values of the misfit stresses are illustrated.

Download Full-text

A Study on Development of the Performance Analysis Method of the Floating OWC-WEC Using the MPS Method

Volume 6: Ocean Space Utilization ◽

10.1115/omae2015-42049 ◽

2015 ◽

Cited By ~ 1

Author(s):

Yutaro Sasahara ◽

Mitsuhiro Masuda ◽

Kiyokazu Minami

Keyword(s):

Wave Energy ◽

Two Phase Flow ◽

Wave Energy Converter ◽

Response Analysis ◽

Phase Flow ◽

Energy Converter ◽

Wave Impact ◽

Two Phase ◽

Mps Method ◽

Type Wave

When concrete examination towards utilization is needed, it is necessary to estimate the safety and the performance of a floating Oscillation Water Column (OWC)-type wave energy converter under abnormal oceanographic phenomenon such as large waves, wave impact force, deck wetness and complex motion of mooring system. Therefore, to choose a proper numerical method is important. This present paper describes a fundamental study about estimation of safety and performance of floating OWC-type wave energy converter using the two-phase flow MPS method. In this research, firstly, new algorithm is installed in order to solve problems of the two-phase flow MPS method. Secondly, applicability to an response analysis of a wharf installation type OWC-WEC of the improved MPS method is examined by wave pressure acting to the OWC-WEC and response in the air chamber of the OWC-WEC.

Download Full-text