Urban noise distributions and the influence of geometric spreading on skewness

2021 ◽  
Vol 150 (2) ◽  
pp. 783-800
Author(s):  
D. Keith Wilson ◽  
Matthew J. Kamrath ◽  
Caitlin E. Haedrich ◽  
Daniel J. Breton ◽  
Carl R. Hart
Keyword(s):  
Urban Noise ◽  
Geometric Spreading

Urban noise distributions and the influence of geometric spreading on skewness

2021 ◽  
Author(s):  
D. Wilson ◽  
Matthew Kamrath ◽  
Caitlin Haedrich ◽  
Daniel Breton ◽  
Carl Hart
Keyword(s):  
Traffic Noise ◽  
Temporal Variations ◽  
Sound Level ◽  
Noise Sources ◽  
Urban Noise ◽  
Broad Perspective ◽  
Source Power ◽  
The North ◽  
Leibler Divergence ◽  
Geometric Spreading

Statistical distributions of urban noise levels are influenced by many complex phenomena, including spatial and temporal variations in the source level, multisource mixtures, propagation losses, and random fading from multipath reflections. This article provides a broad perspective on the varying impacts of these phenomena. Distributions incorporating random fading and averaging (e.g., gamma and noncentral Erlang) tend to be negatively skewed on logarithmic (decibel) axes but can be positively skewed if the fading process is strongly modulated by source power variations (e.g., compound gamma). In contrast, distributions incorporating randomly positioned sources and explicit geometric spreading [e.g., exponentially modified Gaussian (EMG)] tend to be positively skewed with exponential tails on logarithmic axes. To evaluate the suitability of the various distributions, one-third octave band sound-level data were measured at 37 locations in the North End of Boston, MA. Based on the Kullback-Leibler divergence as calculated across all of the locations and frequencies, the EMG provides the most consistently good agreement with the data, which were generally positively skewed. The compound gamma also fits the data well and even outperforms the EMG for the small minority of cases exhibiting negative skew. The lognormal provides a suitable fit in cases in which particular non-traffic noise sources dominate.

Environmental Urban Noise

2003 ◽  
Vol 114 (3) ◽  
pp. 1199-1199
Author(s):  
Daniel R. Raichel
Keyword(s):  
Urban Noise

Effects of urban noise variability on cognitive abilities in indoor spaces: Gender differences

2021 ◽  
pp. 095745652110307
Author(s):  
Massimiliano Masullo ◽  
Gennaro Ruggiero ◽  
Daniel Alvarez Fernandez ◽  
Tina Iachini ◽  
Luigi Maffei
Keyword(s):  
Working Memory ◽  
Verbal Memory ◽  
Cognitive Abilities ◽  
Cognitive Domain ◽  
Cognitive Tasks ◽  
Indoor Environments ◽  
Urban Noise ◽  
Male And Female ◽  
Open Window ◽  
Indoor Spaces

Previous evidence has shown that exposure to urban noise negatively influences some cognitive abilities (i.e. verbal fluency and delayed recall of prose memory) of people in indoor spaces. However, long-standing literature in the cognitive domain has reported that men and women can show different performance on cognitive tasks. Here, we aimed to investigate if and how different patterns of perceived urban noises in indoor environments could affect male and female participants’ cognitive abilities. Ambisonic sound recordings representing scenarios with varying noise patterns (low, medium and high variability) were acquired with an open window at three dwellings in a southern Italian city. As a control condition, the recordings were caught inside a quiet room. While exposed to theses four auditory conditions, participants had to perform cognitive tasks assessing free verbal memory recall, auditory–verbal recognition and working memory. The results show that male and female participants have a different tolerance to noise patterns. Women overperform men on verbal tasks, while the contrary effect emerges with men outperforming women on visuospatial working memory tasks.

Approaches to Urban Noise Management in India

2012 ◽  
Author(s):  
Neelima S. Naik
Keyword(s):  
Urban Areas ◽  
Central Government ◽  
Environmental Concern ◽  
Noise Pollution ◽  
Noise Levels ◽  
Urban Noise ◽  
Master Plans ◽  
The Past ◽  
Metropolitan Cities

Noise pollution in urban areas is recognized as a major environmental concern in India. The lack of infrastructure and fast paced life in major metropolitan cities of India has made the urban environment extremely crowded, busy as well as noisy and as a result the millions of people living in the major metropolitan areas are suffering from the impacts of noise pollution. Noise levels are escalating at such a rate that it has become a major threat to the quality of human lives. Direct links between noise and health have been established by research conducted over the past few decades. There are several causes for urban degradation such as population migration, environmental considerations not adequately being incorporated into master plans, uncoordinated and haphazard development, weak implementation of plans and laws and inadequate institutional competences and resource crunch. This paper discusses the causal factors, impacts and the different approaches adopted by the Central Government as well as some major State Pollution Control Boards to curb the urban noise problem and the need for looking into non-conventional solutions such as Ecocity programme to bring in visible environmental improvement.

scholarly journals Estimation of Spatial Variations in Urban Noise Levels with a Land Use Regression Model

2014 ◽  
Vol 3 (4) ◽  
Author(s):  
Sophie Goudreau ◽  
Céline Plante ◽  
Michel Fournier ◽  
Allan Brand ◽  
Yann Roche ◽  
...  
Keyword(s):  
Land Use ◽  
Regression Model ◽  
Spatial Variations ◽  
Noise Levels ◽  
Land Use Regression ◽  
Urban Noise

3D mapping of kinematic attributes in anisotropic media

Geophysics ◽  
2019 ◽  
Vol 84 (3) ◽  
pp. C159-C170 ◽  
Author(s):  
Yuriy Ivanov ◽  
Alexey Stovas
Keyword(s):  
Anisotropic Medium ◽  
Heterogeneous Media ◽  
Homogeneous Medium ◽  
Anisotropic Media ◽  
Transformation Matrix ◽  
3D Mapping ◽  
Slowness Surface ◽  
Point Correspondence ◽  
Geometric Spreading ◽  
Point To Point

Based on the rotation of a slowness surface in anisotropic media, we have derived a set of mapping operators that establishes a point-to-point correspondence for the traveltime and relative-geometric-spreading surfaces between these calculated in nonrotated and rotated media. The mapping approach allows one to efficiently obtain the aforementioned surfaces in a rotated anisotropic medium from precomputed surfaces in the nonrotated medium. The process consists of two steps: calculation of a necessary kinematic attribute in a nonrotated, e.g., orthorhombic (ORT), medium, and subsequent mapping of the obtained values to a transformed, e.g., rotated ORT, medium. The operators we obtained are applicable to anisotropic media of any type; they are 3D and are expressed through a general form of the transformation matrix. The mapping equations can be used to develop moveout and relative-geometric-spreading approximations in rotated anisotropic media from existing approximations in nonrotated media. Although our operators are derived in case of a homogeneous medium and for a one-way propagation only, we discuss their extension to vertically heterogeneous media and to reflected (and converted) waves.

scholarly journals Experimental evidence for real-time song frequency shift in response to urban noise in a passerine bird

2012 ◽  
Vol 8 (2) ◽  
pp. 320-320 ◽  
Author(s):  
Eira Bermúdez-Cuamatzin ◽  
Alejandro A. Ríos-Chelén ◽  
Diego Gil ◽  
Constantino Macías Garcia
Keyword(s):  
Frequency Shift ◽  
Experimental Evidence ◽  
Real Time ◽  
Passerine Bird ◽  
Urban Noise ◽  
Song Frequency

Amplitude, Fresnel zone, and NMO velocity for PP and SS normal-incidence reflections

Geophysics ◽  
2006 ◽  
Vol 71 (2) ◽  
pp. W1-W14 ◽  
Author(s):  
Einar Iversen
Keyword(s):  
Phase Shift ◽  
Ray Tracing ◽  
Explicit Knowledge ◽  
Fresnel Zone ◽  
Normal Wave ◽  
Normal Incidence ◽  
Geometric Spreading ◽  
Dynamic Ray Tracing ◽  
The One ◽  
Paraxial Ray

Inspired by recent ray-theoretical developments, the theory of normal-incidence rays is generalized to accommodate P- and S-waves in layered isotropic and anisotropic media. The calculation of the three main factors contributing to the two-way amplitude — i.e., geometric spreading, phase shift from caustics, and accumulated reflection/transmission coefficients — is formulated as a recursive process in the upward direction of the normal-incidence rays. This step-by-step approach makes it possible to implement zero-offset amplitude modeling as an efficient one-way wavefront construction process. For the purpose of upward dynamic ray tracing, the one-way eigensolution matrix is introduced, having as minors the paraxial ray-tracing matrices for the wavefronts of two hypothetical waves, referred to by Hubral as the normal-incidence point (NIP) wave and the normal wave. Dynamic ray tracing expressed in terms of the one-way eigensolution matrix has two advantages: The formulas for geometric spreading, phase shift from caustics, and Fresnel zone matrix become particularly simple, and the amplitude and Fresnel zone matrix can be calculated without explicit knowledge of the interface curvatures at the point of normal-incidence reflection.

scholarly journals Comparison study between the elevation and datum statics in NC 210, western Libya

2021 ◽  
Author(s):  
Riyadh Alhajni
Keyword(s):  
Conventional Method ◽  
Seismic Data ◽  
Seismic Velocity ◽  
Sand Dunes ◽  
Angle Of Repose ◽  
Amplitude Analysis ◽  
Reflected Waves ◽  
Geometric Spreading ◽  
Amplitude Compensation ◽  
Seismic Lines

Abstract This research compares the results of each method to solve problems caused by sand dunes, In the southwestern region of Libya, the Murzuq basin is covered with sand dunes, which are a significant source of noise in land seismic data, which caused issues in seismic processing, also sand dunes cause increases of travel time of reflected events in seismic data, procuring false structures this problem caused by residual static errors. The presence of extensive sand dunes causes logistic and technical difficulties for seismic reflection prospecting, Due to the steep angle of repose of the sand dunes faces and the low seismic velocity within them, which causes significant time delay to the reflected waves. In this research, three seismic lines (202, 207, 209), of total length 12 km, have been completely reprocessed at Western Geco processing center (Tripoli) using omega software. the methods of gain corrections: time function gain and geometric spreading. Spreading amplitude compensation, has been proceed the results will be compared to another method of gain corrections called residual amplitude analysis compensation (RAAC) which is has better results for static problems the conventional method of computing field statics has been implemented and the result is compared with elevation static. It is obtained by using uphole method (conventional method) yielded a significant improvement over the elevation method.

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