Wave Structure Interaction

A B S T R A C T This paper reviews the available models for the estimation of mean wave overtopping rate at berm breakwaters. A sensitivity analysis was conducted on selected models in order to study the influence of input variables on estimated overtopping discharge. The dimensionless crest freeboard is the most significant factor influencing the predicted overtopping rate. The sensitivity of overtopping to wave steepness varies from being insensitive, constant, or a function of dimensionless crest freeboard across the formulae analysed. The berm width and berm level (with respect to the still water level) have lower impact on the predicted overtopping compared to that of the crest freeboard. A case study on the sensitivity of predicted overtopping was carried out on Sirevag and Bakkafjordur berm breakwaters and it illustrated that the existing models are most sensitive to the variables of dimensionless crest freeboard, when it is greater than 1.0; and dimensionless berm width, when it is greater than 2.0. Additionally, the case study demonstrated inconsistencies among the models for predicted over-topping. The sensitivities of the estimated overtopping rates to the governing variables were compared with those obtained from experimental data. Among the models, the sensitivity estimations using the artificial neural network of Van Gent et al. (2007) [58] and the Lykke Andersen (2006) [32] formula were found to be in more reasonable agreement with those of the experimental data. The Van der Meer and Janssen (1994) [56] formula showed oversensitivity to the major governing variables. The results of this study throws light on the disparities in accounting the influence of variables, in the estimated overtopping rate at berm breakwaters, using the existing prediction models.

A Modified Bayesian Method (MBM) for estimating directional wave spectra from Doppler spectra obtained by HF radar is examined using field data which were employed in the verification of Bayesian Method (BM). Applicability, validity and accuracy of the MBM are demonstrated compared with the directional wave spectra estimated by BM and observed by buoy acquired from the reliable field data obtained from Surface Current and Wave Variability Experiments (SCAWVEX) project. The necessary conditions of the Doppler spectral components to be used to estimate a reliable directional spectrum are correspondingly estimated by BM. The results clearly demonstrate that directional wave spectra can be estimated by MBM on the basis of Doppler spectra. In addition, though BM shows very time consuming in computations, BM is more robust against the presence of noise than MBM.

Many scientists have advocated that there must be a pilot wave or fundamental controlling wave. The leaders in this area are of course de Broglie and Bohm. contributors (2020d) contributors (2020c) They were correct, however, they never found the actual frequency or pilot wave that they knew must exist. Finally, it has been discovered. By Entangling the CMB not only was the Pilot wave revealed but also an incredible amount of information followed, such as the complete model of the Entangled Hydrogen Atom with the full decoherence cycle or wave collapse, and in this decoherence all the missing pieces of the puzzle were found. Solving all the remaining major problems of Quantum Mechanics, Relativity, and the Pilot Wave Theory. Proving these theories were not incorrect just incomplete. With the Entangled CMB model, it is proven that all these theories combine to make one unified theory. This can only be accomplished with The theory of Complementarity. This is a brief explanation of a small part of this discovery.

The phenomenon of conscious creation of our realities has been discussed with particular reference to three fundamental quantum mechanics theories known as the Schrodinger Cat Experiment (and its interpretation attributed to Copenhagen), the Many Worlds Theory, and the Young's so-called Double-Slit Experiment. It is elucidated that contrary to our common belief that the macroscopic world pre-exists and has a set reality, as far as the position in time and space is concerned, the quantum mechanics asserts that the position of a particle at the quantum state cannot be determined unless a "measurement" of its position is made. More, specifically the position of a particle in space is defined as a quantum wave function that predicts the probability of a position and not it's certain location. Furthermore, it is clarified that, in reality, the fundamental constituents of matter, the electrons, protons, etc. can have two distinct states of existence: particle and wave forms. While the particulate representation of the constituents of matter within the classical macroscopic theory gives the impression of 'existing' at a particular point in space and time, the wave representation asserts an uncertainty of location (known as "superposition'') at any point in the continuum of time and space, until the entity is 'observed.' In this regard, it ascertains that the act of observation affects the position and the energy of a particle. Therefore, an observer is the most important part of a quantum experiment. And, no observation or 'measurement' can be conducted without sentient consciousness. Thus, it is, ultimately, the consciousness that creates the reality behind positioning of any entity in a continuum of time and space. Simply put, quantities only become actual when they are observed consciously. Particles (electrons, protons, neutrons, etc.) as well as we, pop in and out of existence constantly. And, the destinations are what we refer to as the 'parallel dimensions.' In conclusion, the author strongly agrees with the Physicist David Deutsch's argument in his book The Fabric of Reality that the double-slit experiment is evidence for the many-worlds interpretation, thus testifying to the author's assessment that consciousness is a discrete, quantum, and multidimensional phenomenon.

The inclusion of entanglement and decoherence unifying Quantum Mechanics and Relativity. 1. Abstract A new system has been discovered that defies everything we thought we knew about mathematics and science. In a very stunning discovery, for the first time, we can see decoherence, entanglement, and particle creation.
We believed that decoherence would destroy the stable environment and make the particle or wave blink out of existence. However, we now find that decoherence can exist in a stable environment without destroying it and it is crucial to keep the system stable.
Science has largely ignored decoherence because until now we could not calculate or measure it. We assumed it must not be that important. However, with the new system Wave Pattern Entangled Math we have finally lifted the veil on entanglement and decoherence, and we find the bridge to Quantum Mechanics and Relativity.
We find in the decoherence all the answers we have been seeking. In one simple matrix made by decoherence the period or time is accurately calculated not just for the entire cycle but also for each individual photon energy release. Entanglement, coherence, decoherence, time, mass, force, spin, energy, frequency, temperature, and every single attribute known to modern-day physics are represented.
This makes it, I believe one of the most important scientific and mathematical discoveries of all time. It also says that without a doubt it is the key to unlocking the secrets to the universe. The universal code that makes all things. The very code of creation.

A fundamental asymmetry currently exists between the Einstein-Minkowski definition of a single unified spacetime and the separation of space and time variables required by wave theory. The source of this asymmetry is traced back to Einstein's definition of time dilation which, by following the 'world line' of a discrete material particle, not only contravenes Heisenberg's Uncertainty Principle but also the more general condition that time-frequency measurement must be carried out at a single rest point in space relative to each inertial system. Redefining space-time accordingly, the space and time axes for "moving"  systems, expressed in the coordinates of the "stationary" system, become identical to the phase and group velocities of spherical standing waves. By recognising that Einstein's "array" of synchronised clocks, and the Michelson-Morely experiment upon which it was based, has all of the salient features of equal and opposite standing waves, the Lorentz Transformation Equations can then be directly deduced as the wave arguments of these standing wave motions when transformed to other systems of coordinates. Only under this definition can the principle of relativity be upheld. Assigning the proper frame to the observer has the effect of inverting time dilation while leaving the mathematical structure essentially in tact; the standard time-like, space-like and light-like interpretations of the Minkowski interval, for example, find their most natural expression depending upon whether we are measuring frequency, wavelength, or the wavefront of an electromagnetic wave. Inasmuch as energy-momentum depend upon frequency-wavelength, then the equivalence of mass and energy still holds under this interpretation. However, this is no mere trivial change in our `point of view'. Time is now proportional to and transformed together with length, which was always a fundamental condition of wave theory. Since the array of clocks have been synchronised via light waves of universal speed c according to Einstein's second principle, then this leads to a satisfactory definition of time "in general". Reviewing some of the experimental evidence or arguments that are usually cited in defence of time dilation - the Transverse Doppler Effect, the Twins Paradox and acceleration - it is shown that they can and must be reinterpreted in terms of time contraction if the equations are to remain consistent. The empirical evidence obtained by Ives-Stillwel, Hafele-Keating et al. merely proved the existence of a Transverse Doppler Effect, which is here identified with time contraction; the "stationary"  clocks, now defined as objective wave motions, have been contracted with respect to clocks in relative motion and not dilated inversely. Since the empirical predictions are precisely the same as the conventional interpretation - it is the "stationary" clock's that are running fast -  then it becomes a clear case of affirming the consequent. Hence, all of this implies that our sense of space and time, and perhaps even our biological apparatus used in sensory perception, evolved from our experience of observable wave phenomena and not  post hoc from the rods and clocks of our own making. As a final consideration,  if we generalise this Minkowski metric for curved space-time, then the motion of quantum wave-particles under the influence of gravity should follow as a matter of course.

The validation of a high-fidelity uncertainty quantification of a high-speed catamaran is presented, with focus on irregular wave analysis and approximation methods used in design optimization studies, namely a deterministic regular wave approximation, and a stochastic regular wave UQ model. The approach includes a priori CFD simulations, followed by the ex post facto EFD campaign. The validation variables are the wave elevation, x-force, heave and pitch motions, vertical acceleration of the bridge and vertical velocity of the flight deck. Time series values are addressed as primary variables, whereas mean-crossing amplitudes, height, and period are indicated as secondary variables. The subseries and bootstrap methods are applied in order to estimate the validation values and 95% confidence intervals for expected value (EV), standard deviation (SD), mode, and quantile function. Additionally, validation values and confidence intervals for time series EV and SD are evaluated by time series theory, based on the sample variance and size, and the autocovariance function. The deterministic regular wave model assesses the EV of the x-force, whereas the stochastic regular wave UQ focuses on SSAs of pitch, acceleration, and velocity, as relevant merit factors for design optimization. On average, all variables are validated, but the validation uncertainty is quite large, due to limited number of inlet wave components of CFD and short run length for both CFD and EFD. For the evaluation of confidence intervals, the subseries method is found on average more conservative for EV and less conservative for SD, compared to time series theory. Primary variables are validated with an average 5% error and 37% confidence interval. Secondary variables are validated with an average 21% error and 38% confidence interval. The regular wave model is validated with nearly 9% error and 15% confidence interval, whereas the UQ model is validated with an average 1% error and 30% confidence interval.

The booming developments of coastal/offshore renewable energies in recent years call for a powerful numerical code, ideally open-source packaged, to accelerate the researches in the spotlight. This paper presents such an efficient software package for evaluating the performance of floating renewable energy systems in the coastal and offshore regions. It aims to contribute an open-source effort in numerical simulations for ocean energy converters. Though computation of the free-surface effect in moderate depth region is extremely troublesome due to the singularities, the software package proposed in the present paper gives a satisfactory solution to keep the balance of accuracy and efficiency. In the present paper, the interface and structure of the package are introduced in detail so as to be well understood by the reader. Benchmark tests for various types of converters have confirmed the accuracy and efficiency of the package which can be incorporated easily with a frequency domain solver for efficient analysis. By contributing as one of the pioneer works in the open-source effort of evaluating the moderate-depth free-surface Green's function, with its advantages of a reliable accuracy and a relatively low cost, the authors are hoping that the publication of the present software package will promote the continuous researches in developing robust and reliable coastal and offshore renewable energy systems.

Hull-form stochastic optimization methods are developed and evaluated for resistance reduction and operability increase, addressing stochastic sea state and operations. The cost/benefit analysis of the design-optimization procedure is presented, by comparison of four hierarchical problems, from stochastic most general to deterministic least general. The parent hull is a 100 m Delft catamaran, with geometrical constraints for maximum variation of length, beam, draft and displacement. Problem 1 is used as a benchmark for the evaluation of the other problems. It is as a multi-objective stochastic optimization for resistance and operability, considering stochastic sea state and speed, but limited to head waves. Problem 2 is a multi-objective stochastic optimization for resistance and motions at fixed sea state and speed. Problem 3 is a multi-objective deterministic optimization for resistance and motions using a single regular wave at fixed speed. Problem 4 is a single-objective deterministic optimization for calm-water resistance at fixed speed. The design optimization is based on hull modifications by the Karhunen-Loève expansion of a free-form deformation space, URANS simulations, regular wave approximations for irregular wave, metamodels and multi-objective particle swarm. The design optimization achieves an 8.7, 23, 53, and 10% average improvement for problems 1, 2, 3, and 4, respectively. Comparing to problem 1, problem 2, 3, 4 optimized designs have average performances 1, 2.1 and 1.7% worse, respectively. The most efficient problem, from computational cost/benefit analysis, is problem 3. Nevertheless, problem 1 is needed in order to evaluate and compare the stochastic performance of the design, and assess the optimization cost/benefit.

The present research investigates whether it is possible for a listener to identify a specific acoustic configuration, which presents a particular ratio between the fundamental frequency emerging from a major chord and the frequency at which that chord is repeated. This particular ratio is equivalent to the one defining unisons and octaves among pitches in contemporary western music theory.
Notes related through such proportion are conventionally classified into the same pitch class, and trained listeners can discern if two notes pertain to the same pitch class or not.
An experiment was conducted to determine whether subjects could perceive and recognize auditory stimuli whose tempi and tonics mathematically belonged to the same pitch class.
The results of this research indicate that, within a defined acoustic context, the presence of this particular ratio can be accurately identified by listeners.

It will be shown by experimental results that light propagating at right angles to the direction of source movement co-moves with the source due to inertia of energy, thereby allowing vector light speed to exceed the propagation velocity c. Stated another way there is no terrestrial light aberration.

The vast tidal and wave energy resources represent a potential to use marine energy systems to supply part of the global
energy demand. However, there are many advances required to develop economic and reliable marine energy systems,
which some of these advances can be achieved by using the existing knowledge and experience from offshore and wind
energy industry. This research presents a novel marine energy system that integrates the concept of a vertical and horizon-
tal axis wind turbines by combining a Darrieus and Wells type rotor. However, many other different concepts have been
proposed, but models that account for hydrodynamic, structure and control are needed to determine their technical and eco-
nomical feasibility. With the use of the double-multiple streamtube theory, a hydrodynamic model is developed to predict
the performance and the loads on the turbine blades coupled with a finite element model to compute strains and stresses.
To validate the model, we used strain data from field measurement of the demo prototype. The validated model was used
to compute extreme stresses and calculate the fatigue life. The model gives reliable estimates of stresses and fatigue life.
With this result, the design analysis of the turbine blades can be optimized for any site condition and expected life time.

This paper investigates a passive control method of a point absorbing wave energy
converter by considering the displacement and velocity constraints under irregular waves in
the time domain. A linear generator is used as a power take-off unit, and the equivalent
damping force is optimized to improve the power production of the wave energy converter.
The results from nonlinear and linear passive control methods are compared, and indicate
that the nonlinear passive control method leads to the excitation force in phase with the ...

This invention relates to apparatus for balancing inphase and amplitude pulsating or alternating electromotive force waves, and has for its object the provision of an apparatus of this character. For the sake of simplicity, I will throughout this specification, designate the apparatus as a wave balance.

Very large floating rectangular caissons can be used in the construction of breakwaters, piers, or harbor terminals. It may need more than one day to tow these large floating caissons to construction sites. The responses of the floating caissons to ocean waves, wind and tidal currents are one of the concerns in practice. In this paper, we report our on-going work on physical and numerical modeling of a deep draft floating caissons in wave environments. The numerical results obtained by WAMIT and CFD (Star-CCM+) are compared with the experimental results.

In this paper, new formulae are presented to estimate the wave overtopping rate of mass-armoured berm breakwaters. In addition to the effects of dimensionless crest freeboard and crest width, the formulae consider the influences of water depth at the toe of the structure and structure slope on the overtopping rate through simple dimensionless parameters. The performances of the new formulae were then compared with those of the existing empirical prediction formulae. Statistical indicators such as Root Mean Square Error (RMSE) showed that the new formulae are better predictors than the existing ones.

Horse earned special status throughout the human civilization as natural companion. Horses have been offering great contributions to mankind whether in war, movement, agriculture, productivity or developments. So, affection of man to horse and loyalty of horse to man historically seemed to be a real fact. Power, grace, beauty, notability, strength, freedom and peace are the common symbolic meaning of Horses. And the white Horses represent light, sun, day, vitality, illumination, resurrection, messenger of birth and purity.  I painted these thunder white Horses running on the beach with the acrylic on the paper (27.5x34.5 cm).

In this study, the boundary element method-finite element method (BEM-FEM) model is employed to investigate the sloshing and flexibility terms of elastic submerged structures on the behavior of a coupled domain. The methods are finite element and boundary elements which are utilized for structural dynamic and sloshing modeling, respectively. The applied models are used to assess dynamic parameters of a fluid-structure system. Based on the proposed model, a code is developed which can be applied to an arbitrary two-and three-dimensional tank with an arbitrarily shaped elastic submerged structure. Results are validated based on the existing methods represented in the literature and it is concluded that the absolute relative deviation is lower than 2%. Finally, the interactive influences of submerged components which are more meaningful are investigated. ARTICLE HISTORY KEYWORDS fluid-structure interaction; boundary element method (BEM); reduced order modeling; submerged elastic structure; finite element method (FEM)

All human activity that is directly related to the sea, and the phenomenon coastal tides need information about. Sea tides Sounding in the Central Java city of Semarang a crucial factor in the sector transformation sea or management of the sect in relation to an early warning system and the deluge. Sea tides Information which is accurate, it is very important for the community, especially prone to flooding which was within rob or basin area so that the process done earlier evacuation to a lot of material and the sacrifice and soul can be avoided. Functions wavelet able to represent the functions that are not smooth. This is because base in wavelet is determined by the layout and scale (translation and dilatation). Transformation wavelet there are two kinds, Discrete Wavelet Transform (DWT) and Continue Wavelet Transform (CWT). The use a decomposition wavelet has been growing and is considered more suitable is Maximal Overlap Discrete Wavelet Transform (MODWT). Many coefficient wavelet every level MODWT is always the same, it is different with the method DWT that there is always experienced (decimated) in every increase levels. This nature causes MODWT has the advantage doing time series data modeling. Analysis of data can be concluded tide of Semarang using MODWT acquired MSE at least, the decomposition level 4 and there are many coefficient on that level is 5 with the coefficient determination R2 99.26 %
Keywords : Tides, Wavelet, CWT, DWT, MODWT, Time Series

In this paper it has been tried to propose a hypothesis for Universe life cycle from its birth to death along with a cyclic view into its rebirth referring to the concept of Cosmic Microwave Background Radiation, Spiral Structure of Galaxies and Spiral Structure of Elementary Particles. It has been tried to inherit the behaviour of Big Bang in consensus with the proposals of Steady State Cosmology within the vicinity of all modern ongoing researches. It also provides a unified approach for various force interactions of particles through the intrinsic behaviours of Spiral Structure of Elementary Particles. The inverse relation between mass of particle and rate of change of cross section of spiral arms gives us a distinct view of gravitational interactions. Also the orientation of the curl of spiral differentiate the electromagnetic interaction when has revolution and electroweak interaction when has rotational curl. Strong interaction can be described through the phase differences of particles with charge not in multiple of ½. This paper also describes the process for formation off composite particles and the atomic structure through various dynamics of interactions by spiral structured particles.

To analyze seismic wave propagation in geological structures, it is possible to consider various numerical approaches: the finite difference method, the spectral element method, the boundary element method, the finite element method, the finite volume method, etc. All these methods have various advantages and drawbacks. The amplification of seismic waves in surface soil layers is mainly due to the velocity contrast between these layers and, possibly, to topographic effects around crests and hills. The influence of the geometry of alluvial basins on the amplification process is also know to be large. Nevertheless, strong heterogeneities and complex geometries are not easy to take into account with all numerical methods. 2D/3D models are needed in many situations and the efficiency/accuracy of the numerical methods in such cases is in question. Furthermore, the radiation conditions at infinity are not easy to handle with finite differences or finite/spectral elements whereas it is explicitely accounted in the Boundary Element Method. Various absorbing layer methods (e.g. F-PML, M-PML) were recently proposed to attenuate the spurious wave reflections especially in some difficult cases such as shallow numerical models or grazing incidences. Finally, strong earthquakes involve nonlinear effects in surficial soil layers. To model strong ground motion, it is thus necessary to consider the nonlinear dynamic behaviour of soils and simultaneously investigate seismic wave propagation in complex 2D/3D geological structures! Recent advances in numerical formulations and constitutive models in such complex situations are presented and discussed in this paper. A crucial issue is the availability of the field/laboratory data to feed and validate such models.

In his 2015/16 installation piece [INFINITE SPACE], multimedia artist James Weingrod addresses the overlapping disciplines of art, science and architectural theory.  He breaks down the physical space of the Granoff Center of the Arts at Brown University by combining scientific wave theory and the Sublime, while also continuing the "death of the author" through student collaboration and crowdfunding. [INFINITE SPACE] ultimately questions multiple binaries: form and substance, academic division of disciplines, and the assumed transitory nature of installation art.

The presented study introduces a new theoretical model of collapse for social, cultural, or political systems. Based on the current form of quantum anthropology conceptualized by Heidi Ann Russell, further development of this field is provided. The new theoretical model is called the spiral model of collapses, and is suggested to provide an analytical framework for collapses in social, cultural, and political systems. The main conclusions of this study are:
1) The individual crises in the period before a collapse of social, cultural, and political systems form the trajectory of a conical helix similar to a vortex.
2) The occurrences of crises in the period before a collapse have the shape of the trajectory on the surface of the circular cone with a convex wall narrowing up to its peak. The shape of this cone is based on the Fibonacci sequence coiled into the three-dimensional space.
3) The constant circular movement along the trajectory of crises can occur in exceptional situations in the development of social, cultural, and political systems; however, such a state is
always temporary. In such cases, the trajectory of the crisis does not follow the Fibonacci sequence, but the shape of a regular helix. Remaining on the trajectory of a regular helix in the long-term is highly improbable for social, cultural, and political systems.
4) The creation of new potentialities after the final collapse of a system is explained by the conception of topological inversion, when the heretofore embodied part of the energy-information
field returns to the global, wave-particle energy-information potential.
5) The global, wave-particle energy-information potential is a source of energy-information for future embodiments in the sense of the future collapses of wave functions.

In this paper we have tried to deduce the possible origin of particle and evolution of their intrinsic properties through spiral dynamics.  We consider some of the observations which include exponential mass function of particles following a sequence when fitted on logarithmic potential spiral, inwardly rotating spiral dynamics in Reaction-Diffusion System, the separation of Electron’s Spin-Charge-Orbit into quasi-particles. The paper brings a picture of particles and their Anti Particles in spiral form and explains how the difference in structure varies their properties. It also explains the effects on particles in Accelerator deduced through spiral dynamics.

A Modified Bayesian method (MBM) for estimating directional spectra from the Doppler spectra obtained with HF radar is examined using data acquired during the SCAWVEX project. Applicability, validity and accuracy of the MBM are confirmed compared with the directional spectrum observed with a directional buoy. Some assessment studies of a boundary condition are examined to be given at the lowest frequency of directional spectrum so that a suitable directional spectrum can be estimated. The results clearly demonstrate that the directional spectra can properly be estimated without losing its applicability and practicality for estimating directional spectra from field data.

HIGHLIGHT 1. A numerical wave tank (NWT) for violent wave-body interaction is built based on the recently developed δ +-SPH scheme. 2. Adaptive-particle resolution is utilized to improve the local accuracy and reduce total computational costs. 3. Nonlinear interaction between a focusing wave and a floating body with green water overtopping is modeled.

Аннотация. В статье численно исследованы осцилляции амплитуды перекрывающихся им-пульсов – прямоугольного и гауссова в результате интерференции узкополосных составля-ющих импульсов. Исследовано расплывание квантового волнового пакета при распаде ста-ционарного состояния для гармонического осциллятора и прямоугольной потенциальной ямы. Ключевые слова: импульс, узкополосная составляющая, фурье-гармоника, дисперсия.


English version is published in American Journal of Mathematical and Computer Modelling, 2018; 3(1);22-26
Abstract. Numerical analysis of amplitude oscillations of overlapping pulses (rectangular and Gaussian) due to interference of narrowband components of pulses is presented. Spreading of quantum wave packets in the process of decay of stationary state of harmonic oscillator and rectangular potential well have been investigated.

Abstract In case of blast loading on structures, analysis is carried out in two stages, first the blast loading on a particular structure is determined and second, an evaluation is made for the response of the structure to this loading. In this paper, a review of the first part is presented which includes various empirical relations available for computation of blast load in the form of pressure-time function resulting from the explosion in the air.

This document is the final report that provides the summary and findings of a research project into the fields of coastal engineering and recreational surfing parameters. Many high-quality surfing waves exist as by-products of coastal engineering projects, particularly around breakwater structures. This project investigates the relationship between coastal processes, surfability and engineered structures. The aim of the research was to predict the surfability of a site in the vicinity of a breakwater structure, through utilising a numerical wave model (Boussinesq approximation theory) of a chosen site under ideal surfing conditions. A thorough literature review is the foundation of the background section into the fields of coastal processes and surfability is provided to aid the reader to understand the complex phenomena occurring at the site and in the model. The main processes discussed include wave generation, wave classification, refraction, diffraction, reflection, shoaling, breaking, currents, tides, breaker type, peel angle, ride length and wind conditions. An existing site (Dawesville Cut/Mandurah Wedge) was chosen as the case study example for the project because it allowed for physical observations to valid the model. The selected site is an ideal example of the relationship between recreational surfing amenity and fixed coastal engineering structures. This document also discusses the detailed methodology that was followed to achieve the aim and includes a discussion of the results. This research project will benefit future coastal developments by demonstrating the methodology behind the collaborative design of coastal engineering and recreational surfing amenities. A coastal development that promotes community engagement and recreation is more likely to be accepted by the general public and receive positive feedback.

The numerical model FUNWAVE+Ship simulates the generation and propagation of ship waves to shore, including phenomena such as refraction, diffraction, currents and breaking of waves. The interaction of two wave trains, generated by ships moving either in the same direction at different speeds or in opposite directions, is studied. Focus is given to the wave orbital velocities and to the free surface pattern.

The Green function of the diffraction-radiation theory of time-harmonic waves under a moderate water depth is considered. The paper presents a newly developed enhanced algorithm based on Endo's approach, which employs a direct Gauss-Laguerre quadrature in the calculation of the principal value integrations. This methodology was firstly originated from Endo (1983), and had been subsequently improved by Liu et al. (2008) and Shan et al. (2019). Unfortunately, the latest version of Endo's approach still has two fatal problems with (1) incredibly large or small values at some "weird frequencies", and (2) nonsense values in the high-frequency region under a large depth. The present algorithm proposes special techniques for the removal of the singularities at these "weird frequencies", and provides special treatments to avoid exceeding hardware's limitation when the input parameter k 0 h is overlarge. The developed algorithm is thereafter tested against a variety of sea conditions, via a comparison with Newman's polynomial algorithm (Newman, 1985), certifying its good accuracy in various circumstances. By carrying out a benchmark test on the DeepCwind semisubmersible, through a comparison with Shan's algorithm (Shan et al., 2019) and the commericial software Hydrostar®, the cause of the occurrence of the "weird frequencies" is found, in association with other important findings. The computations demonstrate that the present enhanced algorithm is free from the preceding problems and is sufficiently accurate to compute wave loads in practice.

The paper presents the results of mathematical and computer simulation of the interaction of radio pulses of an arbitrary nature. Pulses of a rectangular and Gaussian shape are considered. We also consider the evolution of the wave packet formed as a result of the decay of the bound quantum state. The main reason for the distortion of the pulse shape is the interaction of narrow-band spectral components of pulses.

Ce rapport présente les résultats d'impacts de vagues sur un mur vertical obtenus lors d'une étude comportant des expériences à grande échelle. Cette étude s'intéresse particulièrement aux variations rapides de pression et à sa distribution sur différents types de mur en mer, en rivière ou portuaire. La protection contre les événements extrêmes et l'érosion côtière qui peut en découler constitue une application majeure de ces murs. Les tests ont été effectués dans le nouveau canal à vagues du Laboratoire hydraulique environnemental à Québec (http://lhe.ete.inrs.ca), sur un mur vertical bordé d'une plage présentant une pente de 1:10 et composée d'un mélange de sable, de gravier et de galets. Ce rapport présente les résultats de tests préliminaires effectués à l'automne 2014. Vingt-sept capteurs de pression, distribués sur trois colonnes, ont été installés sur la portion centrale d'un mur constitué d'une plaque d'aluminium renforcée afin d'étudier la distribution des forces sur un mur vertical. Cette section centrale mesure 2.4 m de haut sur 1.2 m de large. Pour couvrir le reste de la largeur du canal (sur 5 m), des pans de mur faits en acier sont ajoutés dans les zones externes. Le mur est conçu de façon à se comporter comme une plaque rigide. Le facteur d'échelle géométrique entre le modèle et le mur réel se situe autour de 1:4. Les vagues incidentes se développent d'abord sur un fond plat, puis grimpent le long d'une plage de 25 m possédant une pente de 1:10. La profondeur d'eau est constante, à h_0 = 3.8 m. Des petits trains de vagues régulières incidentes, dont la hauteur se situe dans l'intervalle 0.85 m < H_0 < 1.3 m, ont été utilisés dans le cadre de cette étude. L'amplitude des vagues incidentes était modérée avec un nombre d'Ursell allant de 18 < Ur < 30. Une profondeur d'eau intermédiaire de 0.107 < h_0/L < 0.109 (où L est la longueur d'onde) a été conservée pour obtenir un déferlement au mur à de faibles profondeurs, 0.021 < hw/L < 0.034. Le nombre de Froude des tests associé au mouvement de la surface libre au pied de la plage était de 0.14 < Fr < 0.23. Les résultats préliminaires rapportés sont basés sur une sélection de six séries de tests (18 impacts sur 150). Les mécanismes sous-jacents aux différents types de déferlement et d'impact sur le mur sont discutés. Premièrement, les résultats montrent que les vagues incidentes d'amplitude maximale ne sont pas nécessairement les plus critiques puisque les vagues peuvent déferler avant d'atteindre le mur. Les cas critiques trouvés sont associés à des déferlantes plongeantes déferlant près du mur xb/Hb < 1 à des profondeurs de hw/h_0 < 1 (où Hb est la hauteur de la déferlante, x b la position du déferlement par rapport au mur et hw est la profondeur au pied du mur). Même si elles sont parfois petites, les poches d'air emprisonnées sous les déferlantes contribuent par leur explosion à l'énergie du jet, impliquant de ce fait des effets de compressibilité. Dans la littérature, des pressions sur le mur de plus de 1 MPa et des jets de 10 m de haut ont été décrits, même pour des vagues incidentes d'amplitude modérée. Le pic de pression maximal identifié dans la présente étude, qui a impliqué une plage composée d'un mélange de gravier, est de 1.2 MPa et a duré 0.1 ms à l'intérieur d'un triple pic de pression. Ce pic a été causé par une déferlante plongeante avec une poche d'air relativement grande et dont la pointe de la crête était située sur le haut du mur. Il a en plus été observé que le pic de pression maximal dans l'eau était du même ordre de grandeur que la pression maximale dans la poche d'air. Par ailleurs, il a pu être observé que les pressions les plus élevées sur le mur n'étaient pas nécessairement associées aux vitesses de jet les plus grandes (liées à la force verticale devant être considérée dans la conception des déflecteurs). Ce sont des variables indépendantes dans ces processus d'interaction très aléatoires, qui comportent des structures d'écoulement variant rapidement dans le temps. La vitesse de jet maximale était de l'ordre de 34 m/s, mais pourrait être plus élevée sur une surface de plage différente (une surface rigide et régulière résultant en de plus grands maximums). Pour cet impact, on retrouvait deux pics de pression quasi simultanés générés par une déferlante plongeante avec deux poches d'air relativement petites. Enfin, un moment de renversement maximal équivalent à 87 MNm/m et une force de cisaillement au pied du mur équivalent à 15.4 MN/m à l'échelle réelle (huit fois plus grand qu'une étude à échelle réduite 1:10.3 a révélé) ont été identifiés. Un affouillement local important pouvait aussi être observé au pied du mur. L'affouillement doit donc être considéré lors de la conception de ce type de mur afin de maintenir sa stabilité.

Very large floating rectangular caissons can be used in the construction of breakwaters, piers, or harbor terminals. It may need more than one day to tow these large floating caissons to construction sites. The responses of the floating caissons to ocean waves, wind and tidal currents are one of the concerns in practice. In this paper, we report our on-going work on physical and numerical modeling of a deep draft floating caissons in wave environments. The numerical results obtained by WAMIT and CFD (Star-CCM+) are compared with the experimental results.

A comparison of two methods, Bayesian Method (BM) and Modified Bayesian Method (MBM), for estimating directional wave spectra from high frequency (HF) ocean radar has been carried out. In terms of validity and applicability, the two recent approaches are compared theoretically and numerically with the equation derived by Barrick (1972). The results show that
the performances of the BM and MBM are adequately good. This comparison suggested that the MBM was more efficient than the BM since the MBM is capable of executing high speed computing and reducing the memory usage. Accordingly, the MBM has a good potential for operational application. The
accuracy and suitability of both the methods are also compared to reliable field data of SCAWVEX`s project. The results indicate that the estimated directional spectra by using the BM and MBM well agree with the result from buoy.
Although the BM is very time consuming to estimate directional spectra from Doppler spectra, this method is more robust in the presence of noise than the MBM.