exposure response relationships for transportation noise this article presents synthesis curves for the relationship between dnl and percentage highly annoyed for three transportation noise sources the results are based on all 21 datasets examined by schultz j acoust soc am 64 377 405 1978 and fidell et al j acoust soc am 89 221 233 1991 for which acceptable dnl and percentage highly annoyed measure could be derived augmented with 34 datasets separate nonidentical curves were found for aircraft road traffic and railway noise a difference between sources was found using data for all studies combined and for only those studies in which respondents evaluated two sources the latter outcome strengthens the conclusion that the differences between sources cannot be explained by differences in study methodology

impact of sampling volume on the probability density function of steady state concentration 1 in recent years statistical theory has been used to compute the ensemble mean and variance of solute concentration in aquifer formations with second order stationary velocity fields the merit of accurately estimating the mean and variance of concentration however remains unclear without knowing the shape of the probability density function pdf in a setup where a conservative solute is continuously injected into a domain the concentration is bounded between zero and the concentration value in the injected solution at small travel distances close to the fringe of the plume an observation point may fall into the plume or outside so that the statistical concentration distribution clusters at the two limiting values obviously this results in non gaussian pdf s of concentration with increasing travel distance the lateral plume boundaries are smoothed resulting in increased probability of intermediate concentrations likewise averaging the concentration in a larger sampling volume as typically done in field measurements leads to higher probabilities of intermediate concentrations we present semianalytical results of concentration pdf s for measurements with point like or larger support volumes based on stochastic theory applied to stationary media to this end we employ a reversed auxiliary transport problem in which we use analytical expressions for first and second central spatial lateral moments with an assumed gaussian pdf for the uncertainty of the first lateral moment and gauss like shapes in individual cross sections the resulting concentration pdf can be reasonably fitted by beta distributions the results are compared to monte carlo simulations of flow and steady state transport in 3 d heterogeneous domains in both methods the shape of the concentration pdf changes with distance to the contaminant source near the source the distribution is multimodal whereas it becomes a unimodal beta distribution far away from the contaminant source the semianalytical and empirical pdf s differ slightly which we contribute to the numerical artifacts in the monte carlo simulations but also to hard assumptions made in the semianalytical approach our results imply that geostatistical techniques for interpolation and other statistical inferences based on gaussian distributions such as kriging and cokriging may be feasible only far away from the contaminant source for calculations near the source the beta like distribution of concentration should be accounted for

particle tracking and the diffusion reaction equation 1 particle tracking algorithms are very useful methods to model conservative transport in surface and subsurface hydrological systems recently a novel ad hoc particle based method was proposed to account for multicomponent reactive transport by benson and meerschaert 2008 this one dimensional particle method has been shown to match theoretical predictions but to date there has been no rigorous demonstration that the particle method actually matches the governing equations for chemical transport we generalize this particle method to two dimensional and three dimensional systems and rigorously demonstrate that this particle method converges to the diffusion reaction equation at the limit of infinitely small time step we also investigate the numerical error associated with the method

nonlinear free vibration behavior of functionally graded plates in this paper an analytical solution is provided for the nonlinear free vibration behavior of plates made of functionally graded materials the material properties of the functionally graded plates are assumed to vary continuously through the thickness according to a power law distribution of the volume fraction of the constituents the fundamental equations for thin rectangular plates of functionally graded materials are obtained using the von karman theory for large transverse deflection and the solution is obtained in terms of mixed fourier series the effect of material properties boundary conditions and thermal loading on the dynamic behavior of the plates is determined and discussed the results reveal that nonlinear coupling effects play a major role in dictating the fundamental frequency of functionally graded plates

reactive random walk particle tracking and its equivalence with the advection diffusion reaction equation we acknowledge the support of the european research council erc through the project mhetscale 617511 and the spanish ministry of economy industry and competitiveness and european regional development fund through the project mecmat cgl2016 80022 r the numerical data can be reproduced following the numerical algorithms and parameter sets given in the paper alternatively the data can be obtained upon request from the corresponding author

community response to noise a review of factors influencing the relationship between noise exposure and reaction social surveys of the relationship between noise exposure and the subjective reactions to it were reviewed this review indicated that remarkably similar results have been obtained across different nationalities with different measurement techniques only a small percentage typically less than 20 of the variation in individual reaction is accounted for by noise exposure analysis of potential errors in both measurement of noise and reaction suggests that elimination of errors would only slightly increase the observed correlations variables such as attitude to the noise source and sensitivity to noise account for more variation in reaction than does noise exposure the weaker relationship between noise exposure and attitude than between reaction and attitude suggests that the attitude reaction relationship is not entirely due to noise exposure causing a change in attitude itself noise reaction correlations based on individual data are significantly lower in studies of impulsive noise than nonimpulsive noise this may be caused in part by the restricted range of noise exposure studied in some socioacoustic investigations of impulsive noise however the significantly higher correlations of attitude and reaction in impulsive noise studies suggest that attitude plays an even larger part while noise exposure plays a lesser part in determining reaction to impulsive noise relative to nonimpulsive noise

reaction rates for a generalized reaction diffusion master equation it has been established that there is an inherent limit to the accuracy of the reaction diffusion master equation specifically there exists a fundamental lower bound on the mesh size below which the accuracy deteriorates as the mesh is refined further in this paper we extend the standard reaction diffusion master equation to allow molecules occupying neighboring voxels to react in contrast to the traditional approach in which molecules react only when occupying the same voxel we derive reaction rates in two dimensions as well as three dimensions to obtain an optimal match to the more fine grained smoluchowski model and show in two numerical examples that the extended algorithm is accurate for a wide range of mesh sizes allowing us to simulate systems that are intractable with the standard reaction diffusion master equation in addition we show that for mesh sizes above the fundamental lower limit of the standard algorithm the generalized algorithm reduces to the standard algorithm we derive a lower limit for the generalized algorithm which in both two dimensions and three dimensions is of the order of the reaction radius of a reacting pair of molecules

nonlinear free and forced vibration analysis of thin circular functionally graded plates in this paper a semi analytical approach for nonlinear free and forced axisymmetric vibration of a thin circular functionally graded plate is developed the plate thickness is constant functionally graded material fgm properties vary through the thickness of the plate for harmonic vibrations by using assumed time mode method and kantorovich time averaging technique the governing equations are solved steady state free and forced vibration analysis is investigated in detail and corresponding results at uniform ambient temperature are illustrated some of these results in special cases are verified by comparing with those in the literature the results show that the free vibration frequencies are dependent on vibration amplitudes and that the volume fraction index has a significant influence on the nonlinear response characteristics of the plate

a logistic prediction model for individual allowable noise levels annoyance to noise is probably a good measure of the potential for complaint and community action each individual s degree of annoyance to noise cannot be accurately predicted from conventional laboratory studies and social surveys therefore a logistic prediction model for individual allowable noise levels has been developed in a previous paper k furihata et al acta acust acust 93 73 83 2007 an annoyance scale using the most frequently used annoyance ratings related to noise for community noise assessment in japan was constructed the dose response relationships were obtained by actually listening to sounds in a field situation 1474 subjects carried out at 14 metropolitan cities in japan the logistic prediction model was developed using the logistic regression parameters estimated from each cumulative percentage curve of seven annoyance scale scores based on all data n 2940 to verify the hypothesis individual relationships between annoyance and laeq 5min for 24 normal hearing subje

a particle number conserving lagrangian method for mixing driven reactive transport the purely lagrangian algorithm for chemical reactions introduced by benson and meerschaert 2008 suffers from a low concentration resolution problem we alleviate the problem by redefining the probabilistic collision reaction birth death stochastic process as a mass reduction operation theoretically this corresponds to replacing an on off particle with a large number of subparticles and tracking the number fraction the new particle reaction process maintains the original particle numbers but adjusts each particle s mass upon reaction several simulations show the veracity as well as the gains in low concentration resolution offered by the algorithm we also compare the results to those obtained by a traditional finite difference model with suitably defined initial condition demonstrating that the lagrangian models match these

connecting the dots semi analytical and random walk numerical solutions of the diffusion reaction equation with stochastic initial conditions we study a system with bimolecular irreversible kinetic reaction a b a where the underlying transport of reactants is governed by diffusion and the local reaction term is given by the law of mass action we consider the case where the initial concentrations are given in terms of an average and a white noise perturbation our goal is to solve the diffusion reaction equation which governs the system and we tackle it with both analytical and numerical approaches to obtain an analytical solution we develop the equations of moments and solve them approximately to obtain a numerical solution we develop a grid less monte carlo particle tracking approach where diffusion is modeled by a random walk of the particles and reaction is modeled by annihilation of particles the probability of annihilation is derived analytically from the particles co location probability we rigorously derive the relationship between the initial number of particles in the system and the amplitude of white noise represented by that number this enables us to compare the particle simulations and the approximate analytical solution and offer an explanation of the late time discrepancies

the schultz curve 25 years later a research perspective the contemporary technical rationale for assessing effects impacts of transportation noise on communities rests in large part on a purely descriptive dosage effect relationship of the sort first synthesized by schultz j acoust soc am 64 377 405 1978 although u s federal adoption of an annoyance based rationale for regulatory policy has made this approach a familiar one it is only one of several historical perspectives and not necessarily the most useful for all purposes last reviewed by the u s federal interagency committee on noise ficon 10 years ago the accuracy and precision of estimates of the prevalence of a consequential degree of noise induced annoyance yielded by functions of noise exposure leave much to be desired this tutorial article traces the development of the dosage effect relationship on which ficon currently relies in a wider historical context of efforts to understand and predict community response to transportation noise it also identifies areas in which advances in genuine understanding might lead to improved means for predicting community response to transportation noise

nonlinear vibration of edge cracked functionally graded timoshenko beams nonlinear vibration of beams made of functionally graded materials fgms containing an open edge crack is studied in this paper based on timoshenko beam theory and von karman geometric nonlinearity the cracked section is modeled by a massless elastic rotational spring it is assumed that material properties follow exponential distributions through beam thickness the ritz method is employed to derive the governing eigenvalue equation which is then solved by a direct iterative method to obtain the nonlinear vibration frequencies of cracked fgm beams with different end supports a detailed parametric study is conducted to study the influences of crack depth crack location material property gradient slenderness ratio and end supports on the nonlinear free vibration characteristics of cracked fgm beams it is found that unlike isotropic homogeneous beams both intact and cracked fgm beams show different vibration behavior at positive and negative amplitudes due to the presence of bending extension coupling in fgm beams

a kernel based lagrangian method for imperfectly mixed chemical reactions abstract current lagrangian particle tracking algorithms used to simulate diffusion reaction equations must employ a certain number of particles to properly emulate the system dynamics particularly for imperfectly mixed systems the number of particles is tied to the statistics of the initial concentration fields of the system at hand systems with shorter range correlation and or smaller concentration variance require more particles potentially limiting the computational feasibility of the method for the well known problem of bimolecular reaction we show that using kernel based rather than dirac delta particles can significantly reduce the required number of particles we derive the fixed width of a gaussian kernel for a given reduced number of particles that analytically eliminates the error between kernel and dirac solutions at any specified time we also show how to solve for the fixed kernel size by minimizing the squared differences between solutions over any given time interval numerical results show that the width of the kernel should be kept below about 12 of the domain size and that the analytic equations used to derive kernel width suffer significantly from the neglect of higher order moments the simulations with a kernel width given by least squares minimization perform better than those made to match at one specific time a heuristic time variable kernel size based on the previous results performs on par with the least squares fixed kernel size

nonlinear vibrations of functionally graded doubly curved shallow shells nonlinear forced vibrations of fgm doubly curved shallow shells with a rectangular base are investigated donnell s nonlinear shallow shell theory is used and the shell is assumed to be simply supported with movable edges the equations of motion are reduced using the galerkin method to a system of infinite nonlinear ordinary differential equations with quadratic and cubic nonlinearities using the multiple scales method primary and subharmonic resonance responses of fgm shells are fully discussed and the effect of volume fraction exponent on the internal resonance conditions softening hardening behavior and bifurcations of the shallow shell when the excitation frequency is i near the fundamental frequency and ii near two times the fundamental frequency is shown moreover using a code based on arclength continuation method a bifurcation analysis is carried out for a special case with two to one internal resonance between the first and second doubly symmetric modes with respect to the panel s center 13 2 11 bifurcation diagrams and poincare maps are obtained through direct time integration of the equations of motion and chaotic regions are shown by calculating lyapunov exponents and lyapunov dimension

thermal effects on geometrically nonlinear vibrations of rectangular plates with fixed edges nonlinear forced vibrations and postbuckling of isotropic rectangular plates subjected to thermal variations are studied geometric imperfections are taken into account since they play a fundamental role the plate is modelled by using the von karman hypothesis and the equations of motion are obtained by using an energy approach plates with fixed edges and additional rotational elastic constraint are considered a pseudo arclength continuation method is used in order to obtain numerical results laboratory experiments have been performed on two plates of different thickness

role of community tolerance level ctl in predicting the prevalence of the annoyance of road and rail noise fidell et al 2011 j acoust soc am 130 2 791 806 have shown 1 that the rate of growth of annoyance with noise exposure reported in attitudinal surveys of the annoyance of aircraft noise closely resembles the exponential rate of change of loudness with sound level and 2 that the proportion of a community highly annoyed and the variability in annoyance prevalence rates in communities are well accounted for by a simple model with a single free parameter a community tolerance level abbreviated ctl and represented symbolically in mathematical expressions as lct expressed in units of dnl the current study applies the same modeling approach to predicting the prevalence of annoyance of road traffic and rail noise the prevalence of noise induced annoyance of all forms of transportation noise is well accounted for by a simple loudness like exponential function with community specific offsets the model fits all of the road traffic findings well but the prevalence of annoyance due to rail no

demographic and attitudinal factors that modify annoyance from transportation noise the effect of demographic variables sex age education level occupational status size of household homeownership dependency on the noise source and use of the noise source and two attitudinal variables noise sensitivity and fear of the noise source on noise annoyance is investigated it is found that fear and noise sensitivity have a large impact on annoyance dnl equivalent equal to at most 19 and 11 db respectively demographic factors are much less important noise annoyance is not related to gender but age has an effect dnl equivalent equal to 5 db the effects of the other demographic factors on noise annoyance are very small i e the equivalent dnl difference is equal to 1 2 db and in the case of dependency 3 db the results are based on analyses of the original data from various previous field surveys of response to noise from transportation sources number of cases depending on the variable between 15 000 and 42000

community reaction to aircraft noise time of day penalty and tradeoff between levels of overflights a decrease in the level of sound events can compensate for an increase in the level of other events but noise metrics assume different tradeoffs noise metrics also differ in the penalty applied to noise in the evening and to noise in the night and in the definition of these periods these two aspects of noise metrics i e the tradeoff and the penalty for the nighttime 23 7h are investigated a general model of the relation between sels of sound events aircraft overflights and noise annoyance is presented which allows for a wide range of tradeoffs and time of day penalties the tradeoff and time of day penalty parameters of the model are fitted to the data from an aircraft noise study conducted around amsterdam airport schiphol which is especially suited for investigating the tradeoff and time of day penalties it was found that in this study the tradeoff between the levels of events in metrics based on l aeq s such as l aeq 24 h dnl and denl is approximately correct for the prediction of noise annoyance furthermore it was found that the strongest correlation with annoyance is obtained with a nighttime penalty of circa 10 db no suitable data were available for further tests of the tradeoff the result with respect to the nighttime penalty was weakly further supported by the outcome of analyses of the original data from four other aircraft noise surveys one survey conducted around british airports and three coordinated surveys carried out around paris orly amsterdam schiphol and glasgow abbotsinch c 2000 acoustical society of america

semi analytical solution for three dimensional vibration of functionally graded circular plates based on the three dimensional theory of elasticity and assuming that the mechanical properties of the materials vary continuously in the thickness direction and have the same exponent law variations the three dimensional free and forced vibration analysis of functionally graded circular plate with various boundary conditions is achieved in this paper a semi analytical method which makes use of the state space method and the one dimensional differential quadrature method is used to obtain the vibration frequencies and dynamic responses of circular plates the analytical solution in the thickness direction can be acquired using the state space method and approximate solution in the radial direction can be obtained using the one dimensional differential quadrature method numerical results are given to demonstrate the accuracy and superiority of the presented method the influences of the material property graded index the circumferential wave number and the forced frequencies on the dynamic behavior for different functionally graded circular plates are also studied

response to comments on a field survey on the annoyance caused by sounds from large firearms and road traffic j acoust soc am 106 1594 1597 1999 percentages of highly annoyed respondents were determined by utilizing the more commonly adopted cutoff point at 72 instead of at 63 of the rating scales the results showed that 1 the community response to the road traffic sounds was not different from that obtained in many other field surveys and 2 the overall adjustment to the c weighted day night level of the artillery sounds was equal to the previously derived adjustment the estimated optimal parameter values in schomer s new rating procedure for high energy impulsive sounds were hardly different from the previously obtained values it was shown that analyses in which inaudible or faintly audible single events with relatively low csel values were excluded yielded essentially the same results as reported earlier

effect of spatial concentration fluctuations on effective kinetics in diffusion reaction systems 1 the effect of spatial concentration fluctuations on the reaction of two solutes a b c is considered in the absence of fluctuations the concentration of solutes decays as adet bdet t 1 contrary to this experimental and numerical studies suggest that concentrations decay significantly slower existing theory suggests a t d 4 scaling in the asymptotic regime d is the dimensionality of the problem here we study the effect of fluctuations using the classical diffusion reaction equation with random initial conditions initial concentrations of the reactants are treated as correlated random fields we use the method of moment equations to solve the resulting stochastic diffusion reaction equation and obtain a solution for the average concentrations that deviates from t 1 to t d 4 behavior at characteristic transition time t we also derive analytical expressions for t as a function of damkohler number and the coefficient of variation of the initial concentration

crack identification in plates using wavelet analysis in this paper a method for crack identification in plates based on wavelet analysis is presented the case of an all over part through crack parallel to one edge of the plate is considered the vibration modes of the plate are analyzed using the continuous wavelet transform and both the location and depth of the crack are estimated the position of the crack is determined by the sudden change in the spatial variation of the transformed displacement response to estimate the depth of the crack an intensity factor is defined which relates the depth of the crack to the coefficients of the wavelet transform an intensity factor law is established which allows accurate prediction of crack depth the viability of the proposed approach is demonstrated using simulation examples in view of the obtained results the advantages and limitations of the proposed approach as well as suggestions for future work are presented and discussed

do we really need a large number of particles to simulate bimolecular reactive transport with random walk methods a kernel density estimation approach random walk particle tracking methods are a computationally efficient family of methods to solve reactive transport problems while the number of particles in most realistic applications is in the order of 10 6 10 9 the number of reactive molecules even in diluted systems might be in the order of fractions of the avogadro number thus each particle actually represents a group of potentially reactive molecules the use of a low number of particles may result not only in loss of accuracy but also may lead to an improper reproduction of the mixing process limited by diffusion recent works have used this effect as a proxy to model incomplete mixing in porous media in this work we propose using a kernel density estimation kde of the concentrations that allows getting the expected results for a well mixed solution with a limited number of particles the idea consists of treating each particle as a sample drawn from the pool of molecules that it represents this way the actual location of a tracked particle is seen as a sample drawn from the density function of the location of molecules represented by that given particle rigorously represented by a kernel density function the probability of reaction can be obtained by combining the kernels associated to two potentially reactive particles we demonstrate that the observed deviation in the reaction vs time curves in numerical experiments reported in the literature could be attributed to the statistical method used to reconstruct concentrations fixed particle support from discrete particle distributions and not to the occurrence of true incomplete mixing we further explore the evolution of the kernel size with time linking it to the diffusion process our results show that kdes are powerful tools to improve computational efficiency and robustness in reactive transport simulations and indicates that incomplete mixing in diluted systems should be modeled based on alternative mechanistic models and not on a limited number of particles

analysis of the nonlinear vibrations of unsymmetrically laminated composite beams large amplitude free vibrations of unsymmetrically laminated beams using von karman large deflection theory are investigated herein one dimensional finite elements based on classical lamination theory first order shear deformation theory and higher order shear deformation theory having 8 10 and 12 degrees of freedom per node respectively are developed

self reported sleep disturbances due to railway noise exposure response relationships for nighttime equivalent and maximum noise levels the objective of the present survey was to study self reported sleep disturbances due to railway noise with respect to nighttime equivalent noise level lp a eq night and maximum noise level lp a max a sample of 1349 people in and around oslo in norway exposed to railway noise was studied in a cross sectional survey to obtain data on sleep disturbances sleep problems due to noise and personal characteristics including noise sensitivity individual noise exposure levels were determined outside of the bedroom facade the most exposed facade and inside the respondents bedrooms the exposure response relationships were analyzed by using logistic regression models controlling for possible modifying factors including the number of noise events train pass by frequency lp a eq night and lp a max were significantly correlated and the proportion of reported noise induced sleep problems increased as both lp a eq night and lp a max increased noise sensitivity type of bedroom window and pass by frequen

free vibration analysis of functionally graded curved panels using a higher order finite element formulation free vibration analysis of functionally graded curved panels is carried out using a higher order formulation a c0 finite element formulation is used to carry out the analysis the element consists of nine degrees of freedom per node with higher order terms in the taylor s series expansion which represents the higher order transverse cross sectional deformation modes the formulation includes sanders approximation for doubly curved shells considering the effects of rotary inertia and transverse shear a realistic parabolic distribution of transverse shear strains through the shell thickness is assumed and the use of shear correction factor is avoided material properties are assumed to be temperature independent and graded in the thickness direction according to a simple power law distribution in terms of the volume fractions of the constituents heat conduction between ceramic and metal constituents is neglected the accuracy of the formulation is validated by comparing the results with those available in the literature effects of panel geometry parameters and boundary conditions are studied