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environmental noise beside an elevated box girder bridge for urban rail transit

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2021年第1期22卷 53-69页

作者： Yun-fei ZHANG Li LI Zhen-yu LEI Long-bo YU Zheng BU Institute of Rail Transit Tongji UniversityShanghai 201804China Shanghai Key Laboratory of Rail Infrastructure Durability and System Safety Shanghai 201804China

noise generated by trains running on elevated lines creates many disturbances to the normal lives of surrounding residents. Investigations have shown that people living along elevated lines complain that the noise is sometimes unbearable. To better control the noise and optimize the acoustic environment, noise spectrum characteristics were analyzed and compared with a field test and a numerical simulation. Through an energy analysis of the noise on the bridge side, the energy distribution characteristics of the noise at specific measuring points in different frequency bands were obtained. The influence of the Doppler effect on frequency shift was analyzed. Based on the partial coherence theory, a multi-input and single-output program was compiled to calculate the correlation and contribution degree of the bridge structure-borne noise and wheel/rail noise at the one-third octave center frequency. The results show that the peak noises of the bridge and the wheel/rail are concentrated at 31.5–63 Hz and 400–800 Hz, respectively. For environmental noise on the bridge side, the frequency band above 250 Hz is mainly affected by the wheel/rail noise. In areas of noise source strength, the relative ratio of noise energy above 250 Hz can reach 83.4%. noise in the near ground and far bridge area is mainly low-frequency, and the relative energy ratio is about 8.9%. The Doppler effect has an influence of less than 6% on the frequency shift with a speed of 67.9 km/h. In the low-frequency band below 250 Hz, the noise in the acoustic shadow area near the bridge and the ground is mainly contributed to by the vibration-radiated noise of the bridge, of which the contribution of the bottom panel is the most prominent. The noise in the comprehensive noise area of the far bridge is mainly caused by the structure-borne noise of the bridge, and the contribution of each bridge panel is different. This study can provide a reference for finding the source of elevated rail noise in some challe

关键词： Urban rail transit Elevated line environmental noise Box girder bridge Field measurement Acoustic model Doppler effect

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Influence of the environmental noise on determining the period of a torsion pendulum

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Chinese Physics B 2015年第3期24卷 72-77页

作者：罗杰田苑邵成刚王典洪 Faculty of Mechanical and Electronic Information China University of Geosciences School of Physics Huazhong University of Science and Technology

The environmental noise can restrict the accuracy of period estimation since the torsion pendulum is sensitive to weak forces. Two typical models for the environmental noise are proposed to make an evaluation. Generally, the stationary environmental noise is modeled as a white noise, and contributes to the period uncertainty as a function of the initial amplitude, the quality factor, the variance of noise and the time length. As to a sudden sharp disturbance acting on the pendulum, a narrow impulse model is constructed. It results in a sharp jump in the phase difference, which can be excluded with the 3σ criterion for a correction. An experimental data analysis for the measurement of the gravitational constant G with the time-of-swing method shows that the period uncertainty due to the environmental noise is about one and a half times the fundamental thermal noise limit. Though this result is dependent on the ambient environment, the analysis is instructive to improve the measurement accuracy of experiments.

关键词： period estimation environmental noise thermal noise limit uncertainty

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Processing and Unification of environmental noise Data from Road Traffic with Spatial Dimension Collected through Mobile Phones

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Journal of Geoscience and Environment Protection 2016年第13期4卷 1-26页

作者： Petr Duda Laboratory on Geoinformatics and Cartography Masaryk University Brno Czech Republic

noise measurement using mobile phones is now developed very well. While there are some good applications for the measurement of noise from road traffic, thus on processing of measured data is only paid a very little attention. The data, however, are burdened by specific errors and for further work with them it is necessary to adjust and determine their uncertainty. One of the biggest problems is inaccuracy in position versus the noise source and the shortest length of measurement that can be regarded as representative. Imprecision in terms of location can be determined by calculating the variance of possible distance from the noise source, which for measurement of traffic noise requires a map-matching data points both transverse to the street (sidewalk) network and in the longwise direction. During typical urban measurements, this error can even reach 7 - 10 dB. Three basic types of algorithms for the calculation of uncertainty and positional correction based on the type of input and output data (raster, vector, vector-oriented) were tested. Uncertainty in the variability of the measurement data is necessary to determine from the number of passing vehicles per time unit. The presented solutions are implemented in the Mobile noise system.

关键词： Measurement Uncertainty environmental noise Mobile Phone Citizen Science noise Mapping

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Stability of a delayed predator prey model in a random environment

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Chinese Physics B 2015年第11期24卷 140-145页

作者：靳艳飞谢文贤 Department of Mechanics Beijing Institute of Technology Department of Applied Mathematics Northwestern Polytechnical University

The stability of the first-order and second-order solution moments for a Harrison-type predator-prey model with parametric Gaussian white noise is analyzed in this paper. The moment equations of the system solution are obtained under Ito interpretations. The delay-independent stable condition of the first-order moment is identical to that of the deterministic delayed system, and the delay-independent stable condition of the second-order moment depends on the noise intensities. The corresponding critical time delays are determined once the stabilities of moments lose. Further, when the time delays are greater than the critical time delays, the system solution becomes unstable with the increase of noise intensities. Finally, some numerical simulations are given to verify the theoretical results.

关键词： delay-independent stability predator-prey model moment equations environmental noise

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Quantum Entanglement and Nonlocality Properties of Two-Mode Squeezed Thermal States in a Common-Reservoir Model

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Communications in Theoretical Physics 2011年第2期55卷 232-238页

作者：向少华宋克慧文伟施振刚 Department of Physics and Information Engineering Huaihua University

We study a system consisting of two identical non-interacting single-mode cavity fields coupled to a common vacuum environment and provide general, explicit, and exact solutions to its master equation by means of the characteristic function method. We analyze the entanglement dynamics of two-mode squeezed thermal state in this model and show that its entanglement dynamics is strongly determined by the two-mode squeezing parameter and the purity. In particular, we find that two-mode squeezed thermal state with the squeezing parameter r ≤ -（1/2） In √u is extremely fragile and almost does not survive in a common vacuum environment. We investigate the time evolution of nonlocality for two-mode squeezed thermal state in such an environment. It is found that the evolved state loses its nonlocality in the beginning of the evolution, but after a time, the revival of nonlocality can occur.

关键词： keytwo-mode squeezed thermal state entanglement Bell's inequality environmental noise

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Synchronization in a Mutualism Ecosystem Induced by noise Correlation

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Communications in Theoretical Physics 2008年第9期50卷 793-796页

作者： ZHONG Wei-Rong SHAO Yuan-Zhi BIE Meng-Jie HE Zhen-Hui School of Physics ＆ Engineering Sun Yat-sen University Guangzhou 510275 China Centre for Nonlinear Studies Hong Kong Baptist University Kowloon Tong Hong Kong China

Understanding the cause of the synchronization of population evolution is an important issue for *** we present a Lotka-Volterra-type model driven by two correlated environmental noises and show,via theoretical analysis and direct simulation,that noise correlation can induce a synchronization of the *** series of mutual species exhibit a chaotic-like fluctuation,which is independent of the noise correlation,however,the chaotic fluctuation of mutual species ratio decreases with the noise correlation.A quantitative parameter defined forcharacterizing chaotic fluctuation provides a good approach to measure when the complete synchronization happens.

关键词： environmental noise correlation synchronous fluctuation chaos population dynamics mutualism

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Short Form of Weinstein noise Sensitivity Scale(NSS-SF): Reliability, Validity and Gender Invariance among Chinese Individuals

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Biomedical and environmental Sciences 2018年第2期31卷 97-105页

作者： ZHONG Tao CHUNG Pak-kwong LIU Jing Dong Faculty of Social Science Hong Kong Baptist University

Objective Independent from noise exposure, noise sensitivity plays a pivotal role in people＇s noise annoyance perception and concomitant health deteriorations. The present study empirically investigated the psychometric properties of the Chinese version of the Weinstein noise Sensitivity Scale-Short Form （CNSS-SF）, the widely used inventory measuring individual differences in noise *** In total, 373 Chinese participants （age = 21.41 ± 3.36） completed the online, anonymous questionnaire package. Examination of the CNSS-SF＇s reliability （internal consistency）, factorial validity through validation and cross-validation, nomological validity and measurement invariance across gender groups were *** The Cronbach alpha coefficients and composite reliabilities indicated sufficient reliability of the CNSS-SF. Two confirmatory factor analyses （CFA）, in two randomly partitioned groups of participants, substantiated the factorial validity of the scale. The nomological validity of the scale was also corroborated by the significant positive association of its score with the trait anxiety score. Measurement invariance of the CNSS-SF was also found across genders via multi-group *** Though not without limitations, findings from the present research provide promising evidence for the utility of the scale in measuring noise sensitivity among the Chinese population. The availability of the CNSS-SF can promote research related to environmental noise and health in China, as well as facilitate cross-cultural comparisons.

关键词： environmental noise Individual differences Cross-cultural validation Measurement Publichealth

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The main projects and development status of noise forecasting and controlling on working face in coal mine

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Journal of Coal Science & Engineering(China) 2010年第2期16卷 198-205页

作者： PENG You-duo GUO Ying-fu WU Li-tao LI Xin XIE Wei-hua Dhillon B S Hunan Provincial Key Laboratory of Health Maintenance for Mechanical Equipment Hunan University of Science and Technology Xiangtan 411201 China Department of Mechanical Engineering of University of Ottawa Canada ON K1N 6N5 Canada

noise from the machine on coal working face seriously influenced the miners' physical and mental health, and also, due to the noise, there may be a major hidden danger in safety from accidents as all safety warning signals may be masked by the noise. This paper summarized the features of mine environmental noise on working face, such as the variety of noise sources, the continuity of high intensity and slow attenuation in narrow space, *** main projects about noise forecasting and controlling on working face was emphatically expounded;the development status about mines machinery noise mechanism and environmental noise acoustic characteristics of space-time of these main research topics were also introduced.

关键词： coal mine working face environmental noise main projects development status

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noise Exposure Levels in Basic School Environments in a City in Ghana

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Open Journal of Civil Engineering 2021年第1期11卷 81-95页

作者： Lois N. K. Quartey Samuel Amos-Abanyie Samuel O. Afram Project Coordinator Building Early Accra Project/Sociarchi Accra Ghana Department of Architecture Kwame Nkrumah University of science and Technology Kumasi Ghana

Basic schools that are located in heavily populated residential and commercial areas in Ghana are exposed to environmental noise that can have detrimental effects on the academic attainments of children. Limited studies have been conducted on noise level in basic schools to date in Ghana. The objective of the study was to assess noise levels in and around learning spaces in basic schools in Ghana with a focus on Kumasi. A survey employing the use of interviews and an empirical monitoring of noise levels in and around learning spaces in four selected basic schools were adopted. The study revealed that mean outdoor and indoor noise levels exceed the World Health Organisation permissible limits by 30 - 40 percent and 90 - 107 percent respectively for schools in the commercial zones and schools that are located near highways. The school that is sited in an educational environment with a setback from the highway attained mean noise levels ranging from 1.2 percent below to 3.7 percent above the permissible limits for outdoor and between 64 - 105 percent for indoor. The outcome of the study is expected to engender the design of environmental noise resilient buildings to facilitate teaching and learning in basic schools in Ghana.

关键词： environmental noise Sound Level Basic Schools Central Business District Kumasi

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The Concept of Using the Strategic noise Maps inPlanning of Urban Space in Poland

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Journal of Civil Engineering and Architecture 2013年第5期7卷 601-608页

作者： Kinga Szopifiska Janusz Kwieciefi Department of Geomatics Geodesy and Spatial Economy University of Technology and Life Sciences Bydgoszcz 85-225 Poland

In the territory of Poland the manner of urban space management is defined by a planning document called LLUP （local land use plan）. When analyzing the development process of Polish cities, an obvious conclusion emerges about the lack of complex studies and researches of the environment concerning the issue of acoustic climate. The procedures of development of local land use plan involve merely a general diagnosis of an environment excluding measured values of pollution, including noise levels. The main aim of this article is to introduce the issue of the influence that acoustic climate has on the urban space planning with the application of SNM （strategic noise mapping）. The map enables holistic assessment of the degree to which urban areas are exposed to noise, determines its sources and forecasts variations of its levels. Preliminary research results confirmed the necessity of including noise level influence in the procedures related to urban space planning especially concerning its forecasted levels resulting from estimates of local land use plans. Applying SNM in verification of conceptual space arrangements in terms of protection against noise in the preparation of LLUP as well as their further application in the plan is a considerable advantage.

关键词： Spatial planning environmental noise strategic noise map.

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