Articles de revues : « Wave-based Methodology »

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Guan, X. « Supersonic wing-body wave drag co-ordinated optimisation based on FCE methodology ». Aeronautical Journal 118, n^o 1209 (novembre 2014) : 1359–72. http://dx.doi.org/10.1017/s0001924000010010.

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Abstract Wave drag reduction is important for the aerodynamic performance optimisation of supersonic cruise aircrafts, such as the supersonic civil transport and the supersonic cruise missile. In this paper a method of the supersonic wing-body wave drag optimisation, the wave drag co-optimisation based on far-field composite elements (CoFCE), is proposed based on class-shape-transformation (CST) parameterisation. Wave drag optimisation cases of a supersonic civil transport wing-body are presented, including the optimisation results and computation cost analyses. It is suggested that the supersonic wing-body wave drag can be significantly reduced by the proposed method with relatively small numbers of design parameter. In the optimisation case presented in this paper a 45% wave drag reduction is achieved. The wave drag optimised configuration also achieved significant lift to drag ratio improvements in small angles-of-attack supersonic cruise flight conditions.

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Zhang, Songhan, Ruili Shen, Kaoshan Dai, Lu Wang, Guido De Roeck et Geert Lombaert. « A methodology for cable damage identification based on wave decomposition ». Journal of Sound and Vibration 442 (mars 2019) : 527–51. http://dx.doi.org/10.1016/j.jsv.2018.11.018.

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Liu, Hongwei, Mustafa Naser Al-Ali et Yi Luo. « Converted-wave model building and imaging based on common-focus-point methodology ». GEOPHYSICS 85, n^o 6 (13 octobre 2020) : U139—U149. http://dx.doi.org/10.1190/geo2019-0549.1.

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Seismic images can be viewed as photographs for underground rocks. These images can be generated from different reflections of elastic waves with different rock properties. Although the dominant seismic data processing is still based on the acoustic wave assumption, elastic wave processing and imaging have become increasingly popular in recent years. A major challenge in elastic wave processing is shear-wave (S-wave) velocity model building. For this reason, we have developed a sequence of procedures for estimating seismic S-wave velocities and the subsequent generation of seismic images using converted waves. We have two main essential new supporting techniques. The first technique is the decoupling of the S-wave information by generating common-focus-point gathers via application of the compressional-wave (P-wave) velocity on the converted seismic data. The second technique is to assume one common VP/ VS ratio to approximate two types of ratios, namely, the ratio of the average earth layer velocity and the ratio of the stacking velocity. The benefit is that we reduce two unknown ratios into one, so it can be easily scanned and picked in practice. The PS-wave images produced by this technology could be aligned with the PP-wave images such that both can be produced in the same coordinate system. The registration between the PP and PS images provides cross-validation of the migrated structures and a better estimation of underground rock and fluid properties. The S-wave velocity, computed from the picked optimal ratio, can be used not only for generating the PS-wave images, but also to ensure well registration between the converted-wave and P-wave images.

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Amlani, Faisal, et Niema M. Pahlevan. « A stable high-order FC-based methodology for hemodynamic wave propagation ». Journal of Computational Physics 405 (mars 2020) : 109130. http://dx.doi.org/10.1016/j.jcp.2019.109130.

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Quiroga, Jabid, John Quiroga, Luis Mujica, Rodolfo Villamizar et Magda Ruiz. « Temperature Robust PCA Based Stress Monitoring Approach ». Key Engineering Materials 713 (septembre 2016) : 288–92. http://dx.doi.org/10.4028/www.scientific.net/kem.713.288.

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In this paper, a guided wave temperature robust PCA-based stress monitoring methodology is proposed. It is based on the analysis of the longitudinal guided wave propagating along the path under stress. Slight changes in the wave are detected by means of PCA via statistical T2 and Q indices. Experimental and numerical simulations of the guided wave propagating in material under different temperatures have shown significant variations in the amplitude and the velocity of the wave. This condition can jeopardize the discrimination of the different stress scenarios detected by the PCA indices. Thus, it is proposed a methodology based on an extended knowledge base, composed by a PCA statistical model for different discrete temperatures to produce a robust classification of stress states under variable environmental conditions. Experimental results have shown a good agreement between the predicted scenarios and the real ones

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Cilici, Florent, Manuel J. Barragan, Estelle Lauga-Larroze, Sylvain Bourdel, Gildas Leger, Loic Vincent et Salvador Mir. « A Nonintrusive Machine Learning-Based Test Methodology for Millimeter-Wave Integrated Circuits ». IEEE Transactions on Microwave Theory and Techniques 68, n^o 8 (août 2020) : 3565–79. http://dx.doi.org/10.1109/tmtt.2020.2991412.

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Nazarov, D. V., D. V. Antipov et O. V. Lomovskoy. « MANUFACTURING PROCESS OF FLEXIBLE WAVE GEAR WHEELS BASED ON THE PFMEA METHODOLOGY ». Izvestiya of Samara Scientific Center of the Russian Academy of Sciences 25, n^o 3 (2023) : 26–34. http://dx.doi.org/10.37313/1990-5378-2023-25-3-26-34.

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The article presents a model for assessing the risks of potential failures of the machining process of flexible wheels of wave gears (WG). The constructed model is based on the methodology for analyzing the types and consequences of potential process inconsistencies (PFMEA). Structural, functional analysis and analysis of failures arising in the process of turning, grinding and cutting the teeth of a flexible wheel are carried out. As a result of the analysis, a risk assessment was carried out and a list of measures aimed at improving the quality of the machining process of flexible wheels of the WG was established.

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Shi, Hongda, Chenyu Zhao, Martyn Hann, Deborah Greaves, Zhi Han et Feifei Cao. « WHTO : A methodology of calculating the energy extraction of wave energy convertors based on wave height reduction ». Energy 185 (octobre 2019) : 299–315. http://dx.doi.org/10.1016/j.energy.2019.07.068.

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Hegermiller, C. A., J. A. A. Antolinez, A. Rueda, P. Camus, J. Perez, L. H. Erikson, P. L. Barnard et F. J. Mendez. « A Multimodal Wave Spectrum–Based Approach for Statistical Downscaling of Local Wave Climate ». Journal of Physical Oceanography 47, n^o 2 (février 2017) : 375–86. http://dx.doi.org/10.1175/jpo-d-16-0191.1.

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AbstractCharacterization of wave climate by bulk wave parameters is insufficient for many coastal studies, including those focused on assessing coastal hazards and long-term wave climate influences on coastal evolution. This issue is particularly relevant for studies using statistical downscaling of atmospheric fields to local wave conditions, which are often multimodal in large ocean basins (e.g., Pacific Ocean). Swell may be generated in vastly different wave generation regions, yielding complex wave spectra that are inadequately represented by a single set of bulk wave parameters. Furthermore, the relationship between atmospheric systems and local wave conditions is complicated by variations in arrival time of wave groups from different parts of the basin. Here, this study addresses these two challenges by improving upon the spatiotemporal definition of the atmospheric predictor used in the statistical downscaling of local wave climate. The improved methodology separates the local wave spectrum into “wave families,” defined by spectral peaks and discrete generation regions, and relates atmospheric conditions in distant regions of the ocean basin to local wave conditions by incorporating travel times computed from effective energy flux across the ocean basin. When applied to locations with multimodal wave spectra, including Southern California and Trujillo, Peru, the new methodology improves the ability of the statistical model to project significant wave height, peak period, and direction for each wave family, retaining more information from the full wave spectrum. This work is the base of statistical downscaling by weather types, which has recently been applied to coastal flooding and morphodynamic applications.

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Morency, Christina. « Electromagnetic wave propagation based upon spectral-element methodology in dispersive and attenuating media ». Geophysical Journal International 220, n^o 2 (13 novembre 2019) : 951–66. http://dx.doi.org/10.1093/gji/ggz510.

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SUMMARY We build on mathematical equivalences between Maxwell’s wave equations for an electromagnetic medium and elastic seismic wave equations. This allows us to readily model Maxwell’s wave propagation in the spectral-element codes SPECFEM2D and SPECFEM3D, written for acoustic, viscoelastic and poroelastic seismic wave propagation, providing the ability to handle complex geometries, inherent to finite-element methods and retaining the strength of exponential convergence and accuracy due to the use of high-degree polynomials to interpolate field functions on the elements, characteristic to spectral-element methods (SEMs). Attenuation and dispersion processes related to the frequency dependence of dielectric permittivity and conductivity are also included using a Zener model, similar to shear attenuation in viscoelastic media or viscous diffusion in poroelastic media, and a Kelvin–Voigt model, respectively. Ability to account for anisotropic media is also discussed. Here, we limit ourselves to certain dielectric permittivity tensor geometries, in order to conserve a diagonal mass matrix after discretization of the system of equations. Doing so, simulation of Maxwell’s wave equations in the radar frequency range based on SEM can be solved using explicit time integration schemes well suited for parallel computation. We validate our formulation with analytical solutions. In 2-D, our implementation allows for the modelling of both a transverse magnetic (TM) mode, suitable for surface based reflection ground penetration radar type of applications, and a transverse electric (TE) mode more suitable for crosshole and vertical radar profiling setups. Two 2-D examples are designed to demonstrated the use of the TM and TE modes. A 3-D example is also presented, which allows for the full TEM solution, different antenna orientations, and out-of-plane variations in material properties.

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Solari, SebastiÃ¡n, et Rodrigo Alonso. « A NEW METHODOLOGY FOR EXTREME WAVES ANALYSIS BASED ON WEATHER-PATTERNS CLASSIFICATION METHODS ». Coastal Engineering Proceedings, n^o 35 (23 juin 2017) : 23. http://dx.doi.org/10.9753/icce.v35.waves.23.

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Extreme Value Analysis is usually based on the assumption that the data is independent and homogeneous. Historically the hypothesis of independence has received more attention than the hypothesis of homogeneity. The two most common ways of ensuring independence is to use annual maxima or peaks over threshold approaches. In wave and wind extreme analysis, the usual approaches to achieve homogeneous series have been to work to differentiate according to type of process generating the extreme value (e.g. differentiate between hurricanes and cyclones) and conduct directional analyzes. In this work an alternative approach is proposed, based on the use of cluster analysis methodologies to identify weather circulation patterns that results in extreme wave conditions. The proposed methodology is successfully applied to a case study in the Uruguayan South Atlantic coast. From the obtained results it seems that the proposed methodology is able to differentiate the data in homogenous subsets, not only in terms of the target variable (significant wave height) but also in terms of relevant covariables, like wave direction or sea level, and that the extreme value distribution of the whole data, obtained from the distributions fitted to each subset, is fairly insensitive to the number of weather patterns used in the analysis.

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Inocencio, Ismael Aragorn, Eric Cruz et Edgardo Kasilag. « MULTI-CRITERIA RATINGS METHODOLOGY FOR SUITABILITY EVALUATION OF OPEN PIER SITES ». Coastal Engineering Proceedings, n^o 36v (28 décembre 2020) : 26. http://dx.doi.org/10.9753/icce.v36v.management.26.

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Along a long project coastline, the optimal selection of an open pier site is based on the criterion of minimum wave agitation under prevailing wave conditions. Where multiple sites are being considered, it becomes imperative to carry out a ratings approach where the possible sites are assessed based on a ratings scale with objective weighting coefficients. This paper discusses a methodology applied to a multiple pier site feasibility study of a proposed cargo pier along a relatively sheltered coastline in the Philippines. In order to select the optimal site based on both technical and operational considerations, a multi-criteria ratings approach was applied.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/2VtyKptBIVM

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Chen, Cheng-Tsung, Jaw-Fang Lee, Kuei-Ting Lin et Pi-Sheng Hu. « An Analytical Solution of Transient Wave Generation in the Wave Channel ». Journal of Marine Science and Engineering 10, n^o 9 (26 août 2022) : 1198. http://dx.doi.org/10.3390/jmse10091198.

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Transient characteristics of wave generation in the wave channel can provide unique and important information in contrast to the steady and periodic motion of propagation waves. In this paper, a new analytical solution is proposed for a transient wavemaker problem in the wave channel. The mathematical model of the wavemaker problem is established based on the linear potential wave theory, and a new analytical solution for the corresponding initial and boundary-value problem is presented. The present solution methodology is motivated and developed from old methods shown in literature. The present solution can be mathematically reformulated and shown to be identical to the previous solution using different solution methodology. The present analytical solution is further compared with numerical results and experiments to validate the mathematical model. The present solution is used to calculate the steady state generated wave forms that compare very well with the steady wave theory both in wave length and wave period. The present solution is also used to study unsteady characteristics of wave heights and wave lengths of the leading waves. The present analytical solution methodology can provide an easier approach to obtain the analytical solution for transient wave generation problem in the wave channel.

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Torregrosa, A. J., A. Broatch, X. Margot et J. García-Tíscar. « Experimental methodology for turbocompressor in-duct noise evaluation based on beamforming wave decomposition ». Journal of Sound and Vibration 376 (août 2016) : 60–71. http://dx.doi.org/10.1016/j.jsv.2016.04.035.

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Do, Trung Q., John W. van de Lindt et Daniel T. Cox. « Performance-based design methodology for inundated elevated coastal structures subjected to wave load ». Engineering Structures 117 (juin 2016) : 250–62. http://dx.doi.org/10.1016/j.engstruct.2016.02.046.

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Degrande, Geert, et Guido De Roeck. « FFT-based spectral analysis methodology for one-dimensional wave propagation in poroelastic media ». Transport in Porous Media 9, n^o 1-2 (octobre 1992) : 85–97. http://dx.doi.org/10.1007/bf01039628.

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Thiene, Marco, Z. Sharif-Khodaei et M. H. Aliabadi. « Optimal Sensor Placement for Damage Detection Based on Ultrasonic Guided Wave ». Key Engineering Materials 665 (septembre 2015) : 269–72. http://dx.doi.org/10.4028/www.scientific.net/kem.665.269.

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In this work a methodology for effective positioning of sensors and actuators for damage detection and characterisation is described. The novelty of the proposed methodology is that the fitness function to be optimised does not contain probability of detection (POD) which needs to be obtained for every possible sensor combination. The proposed fitness function is to provide the maximum coverage of the structure via Lamb waves and reduce the negative effects of boundary reflections. Once the fitness function is defines, genetic algorithm (GA) is used as an optimisation strategy to result in optimal sensor positioning.

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Jin, J., X. Wang, Y. Han, Y. Cai, Y. Cai, H. Wang, L. Zhu, L. Xu, L. Zhao et Z. Li. « Combined beef thawing using response surface methodology ». Czech Journal of Food Sciences 34, No. 6 (21 décembre 2016) : 547–53. http://dx.doi.org/10.17221/138/2016-cjfs.

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Based on four thawing methods (still air, still water, ultrasonic wave, and microwave) and single-factor tests, we established a four-factor three-level response surface methodology for a regression model (four factors: pH, drip loss rate, cooking loss rate, protein content). The optimal combined thawing method for beef rib-eye is: microwave thawing (35 s work/10 s stop, totally 170 s) until beef surfaces soften, then air thawing at 15°C until the beef centre temperature reaches –8°C, and finally ultrasonic thawing at 220 W until the beef centre temperature rises to 0°C. With this method, the drip loss rate is 1.9003%, cooking loss rate is 33.3997%, and protein content is 229.603 μg, which are not significantly different from the model-predicted theoretical results (P ≥ 0.05).

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Verdejo, Humberto, Almendra Awerkin, Wolfgang Kliemann, Cristhian Becker, Héctor Chávez, Karina Barbosa et José Delpiano. « A Dynamic Stochastic Hybrid Model to Represent Significant Wave Height and Wave Period for Marine Energy Representation ». Energies 12, n^o 5 (7 mars 2019) : 887. http://dx.doi.org/10.3390/en12050887.

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This paper presents a methodology to represent ocean wave power generation based on real data observation for significant wave height (SWH or H s ) and wave period (WP or T). This technique is based on a hybrid model, which considers Fourier series and stochastic differential equations, allowing a continuous time representation of the random changes in the parameters associated with wave power generation ( H s and T). The methodology is explained, including estimation methods and a validation procedure. The data series generated by the models erre used to create simulated wave power output applying a transformed matrix and a theoretical model. The results validate the utilization of this technique, when the objective is to obtain a robust dynamic representation of a random process, oriented to linear studies.

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CUI, Dongze, Mohamed ICHCHOU, Noureddine ATALLA et Abdel-Malek ZINE. « Computation of the sound transmission loss of heterogeneous periodic structure using the wave finite element-based methodology ». INTER-NOISE and NOISE-CON Congress and Conference Proceedings 270, n^o 4 (4 octobre 2024) : 7021–30. http://dx.doi.org/10.3397/in_2024_3900.

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In the present study, a Wave Finite Element-based method is introduced to estimate the Sound Transmission Loss (STL) of periodic structures with contrasting properties. This method addresses the precision and computational speed limitations of existing methodologies. It calculates the wave STL by applying a plane wave excitation from the ambient medium to a Unit Cell (UC), which is representative of the periodic structure. The STL under Diffuse Acoustic Field (DAF) is then computed by integrating the wave STL over all possible incidence angle ranges. The advantages of this methodology are demonstrated through various configurations, ranging from simple plates to complex laminated structures. Additionally, the study investigates the Mass Law of STL.

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Ramasubramanian, M., TKS Rathish Babu et VRS Rajesh Kumar. « An Conventional Methodology for Brain Finger Printing ». International Journal of Advanced Research in Computer Science and Software Engineering 7, n^o 8 (30 août 2017) : 301. http://dx.doi.org/10.23956/ijarcsse.v7i8.77.

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Brain fingerprinting is based on finding that the brain generates a unique brain wave pattern when a person encounters a familiar stimulus use of functional magnetic resonance imaging in lie detection derives from studies suggesting that persons asked to lie show different patterns of brain activity than they do when being truthful. Issues related to the use of such evidence in courts are discussed. In the field of criminology, a new lie detector has been developed in the United States of America.This invention is supposed to be the best lie detector available as on date and is said to detect even smooth criminals who pass the polygraph test (the conventional lie detector test) with ease. The new method employs brain waves which are, useful in detecting whether the person subjected to the test, remembers finer details of crime. According to the experts, even if the person willingly suppresses the necessary information, the brain wave is sure to trap him.

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Bennett, S. H. « Modeling methodology for vascular input impedance determination and interpretation ». Journal of Applied Physiology 76, n^o 1 (1 janvier 1994) : 455–84. http://dx.doi.org/10.1152/jappl.1994.76.1.455.

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The significance of pulse wave reflections in the pulmonary vascular system is elaborated using a new method to determine the broadband frequency response of input impedance up to frequencies of 100 Hz. A simple data model, based on the signal construct of a wavelet, is used to generalize and reconcile the common approaches to vascular frequency response estimation so that an accurate response can be calculated from physiological waveforms. Input impedance interpretation is accomplished using a structural and functional modeling methodology. To identify internal structural system properties, the methodology of inverse scattering is used to relate observed pulse wave echoes in the frequency response to a longitudinal distribution of reflection sites of anatomic significance. To identify functional interactions with pulmonary vascular wave mechanics, a time series analysis methodology is proposed to describe vascular interactions using a generalized principle of superposition. The methods of determination and interpretation are applied to a sample pressure-flow data set from the pulmonary circulation of a lamb experiencing vascular-ventilatory interaction. The example suggests that the frequency response is consistent with a discrete longitudinal distribution of reflection sites that may be affected by the ventilator.

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Azizi, Sadegh, Majid Sanaye-Pasand, Moein Abedini et Abbas Hassani. « A Traveling-Wave-Based Methodology for Wide-Area Fault Location in Multiterminal DC Systems ». IEEE Transactions on Power Delivery 29, n^o 6 (décembre 2014) : 2552–60. http://dx.doi.org/10.1109/tpwrd.2014.2323356.

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Thompson, Michael, Ivan Zelich, Evan Watterson et Tom E. Baldock. « Wave Peel Tracking : A New Approach for Assessing Surf Amenity and Analysis of Breaking Waves ». Remote Sensing 13, n^o 17 (25 août 2021) : 3372. http://dx.doi.org/10.3390/rs13173372.

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The creation and protection of surfing breaks along populated coastlines have become a consideration for many councils and governments as surfing breaks are a major driver of tourism. To assess the surf amenity of surfing breaks, a quantitative and objective assessment method is required. A new wave peel tracking (WPT) method has been developed using a shore-based camera to assess surf amenity by measuring and quantifying potential surfing ride rate, length, duration, speed and direction on a wave-by-wave basis. The wave peel (or “curl” below the wave peak) is the optimal surfing region on a wave, and each wave peel track represents a surfable ride. Wave peel regions are identified, classified and tracked using traditional and machine learning-based computer vision techniques. The methodology is validated by comparing the rectified wave peel tracks with GPS-measured tracks from surfers in the wave peel regions. The WPT methodology is evaluated with data from a reef and adjacent natural beach at the Gold Coast, Australia. The reef produced longer ride lengths than the nearshore region and showed a consistent breaking location along the reef crest. Spatial maps of the wave peel tracks show the influence of tides on the wave breaking patterns and intensity. The WPT algorithm provides a robust, automated method for quantifying surf amenity to provide baseline data for surf break conservation. The methodology has potential uses to verify numerical modelling of surf breaks and to assess the impact of coastal development on surf breaks.

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Bilbao, Stefan. « Complex Source Distributions in Wave-based Virtual Acoustics ». INTER-NOISE and NOISE-CON Congress and Conference Proceedings 268, n^o 4 (30 novembre 2023) : 4706–16. http://dx.doi.org/10.3397/in_2023_0669.

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In the typical scenario in time-domain wave-based acoustics, the solution to the acoustic wave equation is approximated over a three-dimensional volumetric grid using a time stepping method. In the setting of very large simulations, the grid is normally assumed to be regular (e.g. Cartesian) so that massive parallelism may be exploited. One difficulty has been in representing source distributions that do not conform neatly to a regular grid. Using a Fourier-based optimisation procedure in the wave vector domain, it is possible to represent arbitrary source distributions in a flexible way over a pre-defined collection of grid points. Such a methodology is independent of the particular choice of simulation method and depends only on the regularity of the grid. In this paper, approximations to various simple distributions, including the line source and piston, are examined, with regard to accuracy, rotation of the distribution relative to the grid, and the size of the point cloud used to represent the source. Numerical results are presented.

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Ramos, Victor, Gianmaria Giannini, Tomás Calheiros-Cabral, Paulo Rosa-Santos et Francisco Taveira-Pinto. « An Integrated Approach to Assessing the Wave Potential for the Energy Supply of Ports : A Case Study ». Journal of Marine Science and Engineering 10, n^o 12 (14 décembre 2022) : 1989. http://dx.doi.org/10.3390/jmse10121989.

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In recent years, seaports have faced increasing pressure to transition towards a low-carbon and more sustainable energy model. In this context, the exploitation of the local wave energy resource may appear as a promising alternative. Therefore, the objective of this work is to present a methodology to select the best WEC-site combination to supply the energy demands of ports. To illustrate this methodology, the Port of Leixões (Portugal) is used as a case study. For the selection of wave energy sites in port areas, the methodology proposes a detailed spatial characterisation of both the wave resource and marine uses. For the area of study, having considered the main marine uses (sediment disposal, biodiversity, aquaculture, recreational and navigation), two exploitable wave energy sites (Areas I and II) with average annual energy resources of 24 and 17 kWm−1, respectively, were found. Next, the methodology proposes a techno-economic optimisation of WECs, based on the local wave conditions of Areas I and II, to minimise their associated Levelised Cost of Energy (LCoE). The results obtained confirm the effectiveness of the methodology, with the novel oCECO device, appearing as the most feasible option (with an LCoE of EUR 387.6/MWh) to exploit the wave potential in the surrounding areas of the port.

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Golovin, Yu, I. Nesterenko et S. Vasylenko. « METHODOLOGY FOR CALCULATING THE COVERAGE AREAS OF DIGITAL TELEVISION BROADCASTING ». Information and communication technologies, electronic engineering 4, n^o 1 (12 mai 2024) : 81–92. http://dx.doi.org/10.23939/ictee2024.01.081.

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The introduction of DVB-T2 digital television broadcasting in the VHF waveband is currently underway, and test trials have already been conducted in some regions of Ukraine. To assess the effectiveness of the projects, it is of particular interest to compare the radio coverage areas of digital TV transmitters operating in the VHF and UHF wave bands. This requires extensive calculations for specific locations. For comparison, the city of Kyiv was chosen, where there is one multiplex MX-7 (8 TV channels) in the VHF band, and the following four multiplexes are represented in the UHF band: MX 1 (26 TV channels) and MX 3 (49 TV channels), which operate at the lowest and highest frequencies of the band. In this article, to predict the coverage areas of digital television broadcasting transmitters, the justification of the selected Longley-Rice radio wave propagation model is provided, which allows calculating the radio signal attenuation compared to free space propagation using terrain profiles (digital elevation maps) and the electrical characteristics of the Earth's surface, Taking into account the main mechanisms of radio wave propagation (interference on the line of sight, diffraction on irregular terrain, tropospheric scattering), it is more accurate and its results are closer to actual measurements. The calculations will be carried out using Radio Mobile software based on the Longley-Rice Irregular Terrain Model (ITM) and using Terrain Mission SRTM satellite maps with the possibility of further adding map data and roads from various sources. Based on the ITU R Recommendations on the design of DVB-T2 digital television broadcasting networks, the minimum required field strength to ensure reception with a given quality was calculated and the initial data for predicting the coverage areas of DVB-T2 digital television transmitters were prepared using the example of Kyiv. The proposed methodology and the data obtained will allow to calculate the boundaries of the coverage areas of DVB-T2 digital standard television transmitters in the VHF and UHF wave bands for selected television channels

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Santos, Diogo, Tiago Abreu, Paulo A. Silva, Fábio Santos et Paulo Baptista. « Nearshore Bathymetry Retrieval from Wave-Based Inversion for Video Imagery ». Remote Sensing 14, n^o 9 (30 avril 2022) : 2155. http://dx.doi.org/10.3390/rs14092155.

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A wavelet-based method for bathymetry retrieval using a sequence of static images of the surface wave field, as obtained from video imagery, is proposed. Synthetic images of the water surface are generated from a numerical Boussinesq type model simulating the propagation of irregular waves. The spectral analysis is used to retrieve both wave periods and wavelengths by evaluating the spectral peaks in the time and spatial domains, respectively. The water depths are estimated using the linear dispersion relation and the results are validated with the model’s bathymetry. To verify the proposed methodology, 2D and 3D simulations considering effects of wave shoaling and refraction were performed for different sea conditions over different seafloors. The method’s ability to reproduce the original bathymetry is shown to be robust in intermediate and shallow waters, being also validated with a real case with images obtained with a shore-based video station. The main improvements of the new method compared to the consideration of a single image, as often used in Satellite Derived Bathymetry, is that the use of successive images enables the consideration of different wave periods, improving depth estimations and not requiring the use of subdomains or filters. This image processing methodology shows very positive results to provide bathymetry maps for shallow marine environments and can be useful to monitor the nearshore with high time- and space-resolution at low cost.

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Sardon, J. P. « The 2003 heat wave ». Eurosurveillance 12, n^o 3 (1 mars 2007) : 11–12. http://dx.doi.org/10.2807/esm.12.03.00694-en.

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The July-August 2005 issue of Eurosurveillance focused on the impact on mortality of the 2003 heat wave in Europe, with articles that were based on various methods and looked at different time periods. The subject of this letter is to assess, using a unique methodology, the excess mortality related to the 2003 heat wave across the continent.

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Ciortan, Sorin, et Eugen Rusu. « Analysis of Wave Energy Conversion with Dynamic Systems Theory ». E3S Web of Conferences 103 (2019) : 02003. http://dx.doi.org/10.1051/e3sconf/201910302003.

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In wave energy conversion one of the most important steps is building scenarios about long term efficiency, taking into account that several factors are involved. Based on the assumption that actually the weather conditions show important modifications year by year, analyses of wave power evolution during the exploitation time range must rely on both prediction models and on several options for the conversion device. From this point of view, the wave energy conversion process can be considered a dynamic system. The dynamic system theory based methodology approach systems behaviour through relationships between systems components. Comparing to usual scientific approaches, which try to decompose the analyzed system, this methodology offers a view of entire system behaviour The paper presents a method for building scenarios of wave energy conversion, in the nearshore of the Black Sea, based on a model which includes also forecasts of the weather influence.

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Sakhare, Rahul Suryakant, Howell Li et Darcy M. Bullock. « Methodology for the Identification of Shock Wave Type and Speed in a Traffic Stream Using Connected Vehicle Data ». Future Transportation 3, n^o 4 (1 octobre 2023) : 1147–74. http://dx.doi.org/10.3390/futuretransp3040063.

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The concept of traffic shock waves was first theorized by Lighthill and Whitham in 1955. The identification of shock wave type and speed in a traffic stream provides critical information about the queue formation and its dissipation. This information can be utilized by various stakeholders for traffic management, emergency response, etc. Such information can also be integrated into the travel time prediction models and real-time route diversions for navigation. Past efforts at identifying shock waves used simulation or analysis based on location-based sensors such as loop detectors. This paper describes scalable methodologies for measuring shock wave propagation using Connected Vehicle (CV) data. The techniques to identify the six different types of shock waves are illustrated through case studies from Indiana highways that use both CV data and the corresponding surveillance camera images. The shock wave speeds for each event are estimated using the linear regression model, with most shock wave speed estimates having a coefficient of determination (R2) of 0.9 or better. Although shock wave speeds vary by traffic flow rates and geometry, the typical backward forming shock wave speeds ranged from 1.75 to 11.76 mph whereas the backward recovery shock wave speeds were observed to be between 5.78 and 16.54 mph. These techniques can be adapted for real-time use to assist traffic management centers with estimating upstream propagation and recovery time. A case study with a car fire is used to illustrate how this shock wave speed data can be used to frame discussions with first responders regarding how reducing incident clearance time can reduce the risk of secondary crashes.

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Quan, Yu Sheng, Dai Juan Wang, Guang Chen et Zong Cheng Zhang. « Study on the Methodology of Detection for Power Cable Insulation Defects Based on Oscillatory Wave ». Advanced Materials Research 805-806 (septembre 2013) : 880–83. http://dx.doi.org/10.4028/www.scientific.net/amr.805-806.880.

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Water tree, electrical tree and electrochemical tree formed by premature defects of the cable can induce fault. The failure rate of the cable connecter which is higher than cable itself can emerge water tree, electrical tree and electrochemical tree. Meanwhile, the flashover, partial discharge and overheated of the cable joint are also the important reasons for fault. The oscillatory wave of detecting the power cable insulation defects based on is put forward in this paper in terms of the problems existed in the cable detection technology. With the application of oscillatory wave and signal source on the spot, this method dynamically generates reference database of detecting the cable insulation defects, to discriminate the fault patterns correspond to the maximum of function and detect the type, location and severity of cable insulation's defects. Water tree fault of premature cable itself and cable joint can also be detected in this method.

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Wang, Junfang, Cheuk Ming Mak et Yi Yun. « A methodology for direct identification of characteristic wave-types in a finite periodic dual-layer structure with transverse connection ». Journal of Vibration and Control 18, n^o 9 (5 octobre 2011) : 1406–14. http://dx.doi.org/10.1177/1077546311419699.

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In a companion paper the phenomenon of flexural-longitudinal wave coupling in an infinite dual-beam periodic structure with transverse connection is investigated. The remarkable finding obtained that there was such a periodic structure which conveyed fundamentally three symmetric and three antisymmetric characteristic coupled waves. In this paper, a methodology is proposed to realize the direct identification of characteristic waves from the responses of a finite periodic structure. This represents a considerable departure from traditional methods, in which the assumption of infinite dimension of a periodic structure is implied. It is the inverse process of the traditional studies which obtain characteristic wave-types based on the assumption and then continue the studies with the wave-types. A general expression for the individual transition matrix of one periodic element is defined and derived from two adjacent junction-mobilities of a finite periodic structure. A common transition matrix for all elements is then constructed using responses based on the mathematical analysis of the relations between responses or junction-mobilities, individual transition matrices and characteristic wave-types. Finally, a specific experimental structure and approach was designed to extract the characteristic waves from the responses. All the symmetrical and antisymmetrical characteristic wave-types, except the pairing of near-field wave-types, are extracted from the common transition matrix of the finite periodic structure, demonstrating the feasibility of the method presented.

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Pipberger, H. A., H. V. Pipberger et C. D. McManus. « Methodology of ECG Interpretation in the AVA Program ». Methods of Information in Medicine 29, n^o 04 (1990) : 337–40. http://dx.doi.org/10.1055/s-0038-1634797.

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AbstractThe AVA program combines a thirty-year history with an approach that remains innovative; namely: multivariate statistical analysis on orthogonal ECG leads. Its diagnostic reference base includes only diagnoses independently verified by non-ECG criteria. The diagnostic module assesses probabilities of nine alternative disease categories, based on QRS-T parameters; or four other categories in case of conduction defects. Probabilities of left or right atrial overload are also computed. The program also recognizes wall injury, T-wave abnormalities, electrolyte disturbances, myocardial ischemia, and makes differential diagnoses between strain and digitalis effects. An arrhythmia classification module can generate any of 40 rhythm statements. Signal recognition is based on the spatial velocity function. The program has been translated to a microcomputer version.

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Starodub, Yu, et V. Bagnyuk. « MODELING AND METHODOLOGY OF EVALUATION OF ENGINEERING SITUATION IN RIVER BREAKDOWN OF SEREDNYODNIPROVSKA HES ». Bulletin of Lviv State University of Life Safety 20 (24 janvier 2020) : 96–100. http://dx.doi.org/10.32447/20784643.20.2019.14.

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The article deals with the process of parameters estimation of the flood zone at the dam break or its destruction, and a scale of possible destruction caused by possible emergencies. Modeling is carried out for the time of approach of the breakthrough wave to a given distance, the height of the breakthrough wave, the time of discharge of the reservoir, the duration of the passage of the wave at a predetermined distance for buildings and structures in the area of shock wave. The example is done for the dam of the Middle Dnieper hydroelectric power station. A technique for modeling a hazardous situation related to the consequences of a breakthrough of the dam at the Middle Dnieper Hydropower Plant has been developed. The prediction and simulation is based on the phenomenological parameters of the Kamyansky reservoir.The simulation of the assessment of the engineering environment for the dam of the Serednyodniprovska hydroelectric power station was carried out using the parameters of flooding of the terrain. Parameters used - the possible maximum depth of flooding, the width of flooding and the rate of water flow at the break of the dam, the time of arrival of the wave front, the crest and tail of the break wave, maximal flow dams, wave heights above water level above domestic flow. As a result, the maximum flooded area was estimated.Based on the use of dam and reservoir characteristics and the use of appropriate formulas for calculating emergency factors and using modeling using ArcGIS, the possible topographic consequences of the breakthrough of the dam in the city Kamianske and the locations of industrial enterprises in its vicinity were obtained. The latter enables rescue services to promptly assess the threat of an emergency in the event of an emergency, to have an idea of the consequences in order to take preemptive measures to prevent the occurrence of an emergency.

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Yan, Binpeng, Yongzhen Ji et Peidong Shi. « Frequency-dependent inversion based on spherical-wave reflection coefficient in elastic medium : Theory and methodology ». Journal of Applied Geophysics 209 (février 2023) : 104908. http://dx.doi.org/10.1016/j.jappgeo.2022.104908.

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Davydov, Roman, Anna Zaitceva, Vadim Davydov, Daria Isakova et Maria Mazing. « New Methodology of Human Health Express Diagnostics Based on Pulse Wave Measurements and Occlusion Test ». Journal of Personalized Medicine 13, n^o 3 (28 février 2023) : 443. http://dx.doi.org/10.3390/jpm13030443.

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Nowadays, with the increase in the rhythm of life, the relevance of using express diagnostics methods for human health state estimation has significantly increased. We present a new express diagnostics method based on non-invasive measurements (the pulse wave shape, heart rate, blood pressure, and oxygen saturation of blood vessels and tissues). A feature of these measurements is that they can be carried out both in the hospital and at home. The new compact and portable optical hardware–software complex has been developed to measure tissue oxygen saturation. This complex makes it possible to reduce the measurement time from 60 min to 7–8 min, which reduces the likelihood of artifacts in the measurement process and increases its reliability. A new technique has been developed to carry out these measurements. A new optical sensor based on a line of charge-coupled devices has been developed to register a pulse wave in the far peripheral zone. The developed new technique for processing the pulse waveform and data on the oxygen saturation of hemoglobin in the blood and tissues allows a person to obtain additional information about their state of health independently. It will help to make conclusions about taking the necessary measures. This additional information allows the attending physician to provide more effective control over the course of treatment of the patient at any time since the methods of express diagnostics proposed by us have no restrictions on the number of applications. The functional state of more than 300 patients was studied. The results of various measurements are presented.

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De Leo, Francesco, Sebastián Solari et Giovanni Besio. « Extreme wave analysis based on atmospheric pattern classification : an application along the Italian coast ». Natural Hazards and Earth System Sciences 20, n^o 5 (11 mai 2020) : 1233–46. http://dx.doi.org/10.5194/nhess-20-1233-2020.

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Abstract. This paper provides a methodology for classifying samples of significant wave-height peaks in homogeneous subsets in terms of the atmospheric circulation patterns behind the observed extreme wave conditions. Then, a methodology is given for the computation of the overall extreme value distribution by starting from the distributions fitted to each single subset. To this end, the k-means clustering technique is used to classify the shape of the wind fields that occurred simultaneously to and prior to the occurrences of the extreme wave events. This results in a small number of characteristic circulation patterns related to as many subsets of extreme wave values. After fitting an extreme value distribution to each subset, bootstrapping is used to reconstruct the omni-circulation pattern's extreme value distribution. The methodology is applied to several locations along the Italian buoy network, and it is concluded from the obtained results that it yields a two-fold advantage: first, it is capable of identifying clearly differentiated subsets driven by homogeneous circulation patterns; second, it allows one to estimate high-return-period quantiles consistent with those resulting from the usual extreme value analysis. In particular, the circulation patterns highlighted are analyzed in the context of the Mediterranean Sea's atmospheric climatology and are shown to be due to well-known cyclonic systems typically crossing the Mediterranean basin.

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Rickett, James E. « Illumination‐based normalization for wave‐equation depth migration ». GEOPHYSICS 68, n^o 4 (juillet 2003) : 1371–79. http://dx.doi.org/10.1190/1.1598130.

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Illumination problems caused by finite‐recording aperture and lateral velocity lensing can bias amplitudes in migration results. In this paper, I develop a normalization scheme appropriate for wave‐equation migration algorithms that compensates for irregular illumination. I generate synthetic seismic data over a reference reflectivity model, using the adjoint of wave‐equation shot‐profile migration as the forward modeling operator. I then migrate the synthetic data with the same shot‐profile algorithm. The ratio between the synthetic migration result and the initial reference model is a measure of seismic illumination. Dividing the true data migration result by this illumination function mitigates the illumination problems. The methodology can take into account reflector dip as well as both shot and receiver geometries, and, because it is based on wave‐equation migration, it naturally models the finite‐frequency effects of wave propagation. The reference model should be as close to the true model as possible; good choices include the migrated image, or a synthetic image with a single known dip that corresponds to the expected dip of a reflector of interest. Computational shortcuts allow the illumination functions to be computed at about the cost of a single migration. Results indicate that normalization can significantly reduce amplitude distortions due to irregular subsurface illumination.

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Xiang, Ning, Jack Taylor et Max Miller. « Laser Doppler vibrometry-based measurements on viscoelastic panels for flexural damping properties ». Journal of the Acoustical Society of America 153, n^o 3_supplement (1 mars 2023) : A239. http://dx.doi.org/10.1121/10.0018766.

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Bending wave propagation is of central importance when enhancing sound transmission losses of sandwiched wall board systems incorporating viscoelastic panels as constrained damping layers. The damping properties of constrained damping layers made of viscoelastic materials can often be characterized by bending wave excitations. However, the multifactor, dispersive nature of the bending waves leads to challenges in reliable dynamic material characterization. To better understand the damping mechanism of the constrained damping layers, an experimental methodology employing complex bending wave theory has been developed to determine these flexural wave properties, including the loss factor and the bending stiffness of highly viscous panels. Relying on a transfer function from the experimentally measured bending velocities between two locations radially away from a flexural wave exciter on the viscoelastic panel under test, this methodology yields the broadband bending loss factor, the bending phase speed, and the bending stiffness. This paper discusses the experimental method for characterizing the above properties from laser Doppler vibrometry-based measurements of bending velocities. This paper also discusses the challenges with this method as well as an approach to mitigate the challenging effects and improve measurement accuracy.

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Tien, Nguyen Anh. « To study impact level of dominat parameters and propose estimate methodology for wave transmission efficiency of unconventional complex pile submerged breakwater ». Tạp chí Khoa học và Công nghệ Biển 19, n^o 4 (27 mars 2020) : 611–25. http://dx.doi.org/10.15625/1859-3097/19/4/13080.

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This article proposes semi-empirical equations to estimate wave transmission coefficient through submerged complex with solid pile breakwater based on theories of random wave energy conservation of perpendicular wave transmission incorporated with physical hydraulic experiments in wave flume applied on both types of submerged breakwater with and without piles. These equations are able to describe interactions and energy dissipation process for each element of this complex structure which are foundation block and pile rows. Energy dissipation process depends on three major factors which are [relative submerge depth (Rc/Hm0), relative crest width (B/Hm0), wave slope at construction location (sm=Hm0/Lm)] and wave energy dissipation process through pile rows is determined by two major factors [relative submerged depth or submerged length of piles (Rc/Hm0), relative pile row width (Xb/Lm)].

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Ciortan, Sorin, et Eugen Rusu. « Prediction of the wave power in the Black Sea based on wind speed using artificial neural networks ». E3S Web of Conferences 51 (2018) : 01006. http://dx.doi.org/10.1051/e3scconf/20185101006.

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The paper proposes a prediction methodology for the significant wave height (and implicitly the wave power), based on the artificial neural networks. The proposed approach takes as input data the wind speed values recorded for different time periods. The prediction of significant wave height is useful both for assessment of wave energy as also for marine equipment design and navigation. The data used cover the time interval 1999 to 2007 and it was measured on Gloria drilling unit, which operates in the Romanian nearshore of the Black Sea at about 500 meters depth.

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Ciortan, Sorin, et Eugen Rusu. « Prediction of the wave power in the Black Sea based on wind speed using artificial neural networks ». E3S Web of Conferences 51 (2018) : 01006. http://dx.doi.org/10.1051/e3sconf/20185101006.

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The paper proposes a prediction methodology for the significant wave height (and implicitly the wave power), based on the artificial neural networks. The proposed approach takes as input data the wind speed values recorded for different time periods. The prediction of significant wave height is useful both for assessment of wave energy as also for marine equipment design and navigation. The data used cover the time interval 1999 to 2007 and it was measured on Gloria drilling unit, which operates in the Romanian nearshore of the Black Sea at about 500 meters depth.

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SHABADI, PRASAD, SANKARA NARAYANAN RAJAPANDIAN, SANTOSH KHASANVIS et CSABA ANDRAS MORITZ. « DESIGN OF SPIN WAVE FUNCTIONS-BASED LOGIC CIRCUITS ». SPIN 02, n^o 03 (septembre 2012) : 1240006. http://dx.doi.org/10.1142/s2010324712400061.

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Over the past few years, several novel nanoscale computing concepts have been proposed as potential post-complementary metal oxide semiconductor (CMOS) computing fabrics. In these, key focus is on inventing a faster and lower power alternative to conventional metal oxide semiconductor field effect transators. Instead, we propose a fundamental shift in mindset towards more functional building blocks, replacing simple switches with more sophisticated information encoding and computing based on alternate state variables to achieve a significantly more efficient and compact logic. Specifically, we propose wave computation enabled by magnetic spin wave interactions called as spin wave functions (SPWFs). In SPWFs, computation is based on wave interference and information can be encoded in a wave's phase, amplitude and frequency. In this paper, we provide an update on key fabric concepts and design aspects. Our analysis shows that circuit design choices can have a significant impact on overall fabric/device capabilities required and vice versa. Thereby, we adapt an integrated fabric-circuit exploration methodology. Control schemes for wave streaming and synchronization are also discussed with several SPWF circuit topologies. Our estimations show that significant area and power benefits can be expected for SPWF-based designs versus CMOS. In particular, for a 1-bit adder up to 40X area benefit and up to 304X power consumption reduction may be possible with SPWF-based implementation versus 45 nm CMOS.

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Janquart, Justin, Otto A. Hannuksela, K. Haris et Chris Van Den Broeck. « A fast and precise methodology to search for and analyse strongly lensed gravitational-wave events ». Monthly Notices of the Royal Astronomical Society 506, n^o 4 (15 juillet 2021) : 5430–38. http://dx.doi.org/10.1093/mnras/stab1991.

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ABSTRACT Gravitational waves, like light, can be gravitationally lensed by massive astrophysical objects such as galaxies and galaxy clusters. Strong gravitational-wave lensing, forecasted at a reasonable rate in ground-based gravitational-wave detectors such as Advanced LIGO, Advanced Virgo, and KAGRA, produces multiple images separated in time by minutes to months. These images appear as repeated events in the detectors: gravitational-wave pairs, triplets, or quadruplets with identical frequency evolution originating from the same sky location. To search for these images, we need to, in principle, analyse all viable combinations of individual events present in the gravitational-wave catalogues. An increasingly pressing problem is that the number of candidate pairs that we need to analyse grows rapidly with the increasing number of single-event detections. At design sensitivity, one may have as many as $\mathcal {O}(10^5)$ event pairs to consider. To meet the ever-increasing computational requirements, we develop a fast and precise Bayesian methodology to analyse strongly lensed event pairs, enabling future searches. The methodology works by replacing the prior used in the analysis of one strongly lensed gravitational-wave image by the posterior of another image; the computation is then further sped up by a pre-computed lookup table. We demonstrate how the methodology can be applied to any number of lensed images, enabling fast studies of strongly lensed quadruplets.

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Lee, Jae-Hoon, Yoon-Seo Nam, Jaehak Lee, Yuming Liu et Yonghwan Kim. « Estimation of Significant Wave Height Using Wave-Radar Images ». Journal of Marine Science and Engineering 12, n^o 7 (5 juillet 2024) : 1134. http://dx.doi.org/10.3390/jmse12071134.

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Characteristics of random ocean waves have been measured by different devices, and X-band marine radar is one of the typical devices. This study proposes an enhanced methodology for estimating the significant wave height of ocean waves through the analysis of X-band radar images, particularly leveraging the shadowing characteristics inherent within radar images. The enhancement of the shadowing-based algorithm is achieved by incorporating three different key physical properties of ocean waves. These include the spatial autocorrelation function (SACF) in the Smith function, the orthogonal property of mean surface slopes, and the relationship of high-order spectral moments. The enhanced algorithm is complementarily integrated with fast Fourier transform (FFT)-based spectral analysis, facilitating the determination of significant wave height without the necessity for supplementary reference measurements. Numerical tests have been conducted using synthetic and real radar images corresponding to various sea states to validate the accuracy and reliability of the proposed methodology. The results demonstrate that the proposed techniques consistently improve the estimation accuracy of significant wave heights for both synthetic and real radar images. Even though the measured real radar images used for validation are not exhaustive in terms of the amount of dataset and range of sea state severity, considering that the proposed technique is in its early development stage, it is inspiring that its effectiveness and physical validity have been demonstrated through the present study.

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Shrivastava, Ruchi, et Dr Krishna Teerth Chaturvedi. « Correlation Enhanced Machine Learning Approach based Wave Height Prediction ». SMART MOVES JOURNAL IJOSCIENCE 4, n^o 5 (26 mai 2018) : 10. http://dx.doi.org/10.24113/ijoscience.v4i5.136.

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The prediction of wave height is one of the major problems of coastal engineering and coastal structures. In recent years, advances in the prediction of significant wave height have been considerably developed using flexible calculation techniques. In addition to the traditional prediction of significant wave height, soft computing has explored a new way of predicting significant wave heights. This research was conducted in the direction of forecasting a significant wave height using machine learning approaches. In this paper, a problem of significant wave height prediction problem has been tackled by using wave parameters such as wave spectral density. This prediction of significant wave height helps in wave energy converters as well as in ship navigation system. This research will optimize wave parameters for a fast and efficient wave height prediction. For this Pearson’s, Kendall’s and Spearman’s Correlation Coefficients and Particle Swarm Optimization feature reduction techniques are used. So reduced features are taken into consideration for prediction of wave height using neural network. In this work, performance evaluation metrics such as MSE and RMSE values are decreased and gives better performance of classification that is compared with existing research’s implemented methodology. From the experimental results, it is observed that proposed algorithm gives the better prediction as compared to PSO feature reduction technique. So, it is also concluded that Co-relation enhanced neural network is better as compared to PSO based neural network with increased number of features.

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Wu, Dazhi, Junyi Wang, Tong Miao, Keyu Chen et Zilong Zhang. « Performance Optimization of FA-GGBS Geopolymer Based on Response Surface Methodology ». Polymers 15, n^o 8 (14 avril 2023) : 1881. http://dx.doi.org/10.3390/polym15081881.

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Many scholars have focused on the workability and mechanical properties of fly ash (FA)- ground granulated blast furnace slag (GGBS) geopolymer. To enhance the compressive strength of geopolymer, zeolite powder was added in the present study. A series of experiments were carried out to investigate the effect of using zeolite powder as an external admixture on the per-formance of FA-GGBS geopolymer, 17 sets of experiments were designed and tested to deter-mine the unconfined compressive strength based on the response surface methodology, and then, the optimal parameters were obtained via modeling of 3 factors (zeolite powder dosage, alkali exciter dosage, and alkali exciter modulus) and 2 levels of compressive strength (3 d and 28 d). The experimental results showed that the strength of the geopolymer was the highest when the three factors were 13.3%, 40.3%, and 1.2. Finally, a combination of scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and 29Si nuclear magnetic resonance (NMR) analysis was used to conduct micromechanical analysis and explain the reaction mechanism from a microscopic perspective. The SEM and XRD analysis revealed that the microstructure of the geopolymer was the densest when the zeolite powder was doped at 13.3%, and the strength increased accordingly. The NMR and Fourier transform infrared spectroscopy analyses revealed that the absorption peak wave number band shifted toward the lower wave number band under the optimal ratio, and the silica–oxygen bond was replaced by an aluminum–oxygen bond, which generated more aluminosilicate structures.

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Arcos, Robert, Paulo J. Soares, Kenny F. Conto, Pedro Alves Costa et Luís Godinho. « A numerical validation of a 3D hybrid meshless methodology for dynamic soil-structure interaction problems ». Journal of Physics : Conference Series 2647, n^o 20 (1 juin 2024) : 202009. http://dx.doi.org/10.1088/1742-6596/2647/20/202009.

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Abstract In this paper, a hybrid meshless methodology for the simulation of dynamic soil-structure interaction problems is verified in a three-dimensional context. The method aims to predict the ground-borne noise and vibration levels to which a new building to be constructed close to a ground vibration source will be subjected. The method is based on three steps: incident wave field evaluation in a set of collocation points, incident wave field virtualization by a set of virtual forces and structure response determination applying the set of virtual forces to a coupled soil-structure model. The proposed meshless method is verified in the context of the problem of one and four shallows foundations embedded in a homogeneous half-space subjected to harmonic loading using synthetic data for the incident wave field in the ground surface. Discussions on the practical deployment of the method are also included.

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INAFUNE, K. « W-Band Active Integrated Antenna Oscillator Based on Full-Wave Design Methodology and 0.1- m Gate InP-Based HEMTs ». IEICE Transactions on Electronics E89-C, n^o 7 (1 juillet 2006) : 954–58. http://dx.doi.org/10.1093/ietele/e89-c.7.954.

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