نتایج جستجو برای: parallel noise barrier
تعداد نتایج: 501061 فیلتر نتایج به سال:
the paper presents the results of an investigation on the acoustic performance of vertical profile parallel barriers with quadratic residue diffuser tops and faces. a 2d boundary element method (bem) was used to predict the barrier insertion loss. the results of rigid and with absorptive coverage were also calculated for comparisons. using qrd on the top surface and faces of all vertical profil...
performance of profiled vertical reflective parallel noise barriers with quadratic residue diffusers
the paper presents the results of an investigation on the acoustic performance of vertical profile parallel barriers with quadratic residue diffuser tops and faces. a 2d boundary element method (bem) is used to predict the barrier insertion loss. the results of rigid and with absorptive coverage are also calculated for comparisons. using qrd on the top surface and faces of all vertical profile ...
Background and aimsThe paper presents the results of an investigation on the acoustic performance of tilted profile parallel barriers with quadratic residue diffuser tops and faces.MethodsA2D boundary element method (BEM) is used to predict the barrier insertion loss. The results of rigid and with absorptive coverage are also calculated for comparisons. Using QRD on the top surface and faces o...
Introduction: Over recent years, various programs have been conducted to reduce noise, indicating the increasing concerns of society over noise pollution. This study has been performed to enhance the performance of parallel barriers on two sides of a highway considering the surrounding buildings. Material and Methods: The 2D boundary element simulation method was employed to predict the noise ...
Background and aims Traffic noise barriers are the most important measure to control the environmental noise pollution. Diffraction from top edge of noise barriers is the most important path of indirect sound wave moves towards receiver.Therefore, most studies are focused on improvement of this kind. Methods T-shape profile barriers are one of the most successful barrier among many dif...
Background and Objective: Efforts to improve the effectiveness of noise barriers have been made, including shape, aesthetics, form and gender. Therefore, the aim of this study was to investigate the effect of the angle upper edge in shaped noise barriers with a T-shaped upper edge. Materials and Methods: A 2D boundary element method (BEM) was used to predict the insertion loss of the tested ba...
Backgrounds and Objectives: There is a considerable notice in the use of noise barriers in recent years. Noise barriers as a control noise solution can increase the insertion loss to protect receivers. This paper presents the results of an investigation about the acoustic efficiency of primitive root sequence diffuser (PRD) on environmental single T-shape barrier.Materials and Methods: A 2D bou...
the paper describes an investigation about the application of the new multiple-impedance discontinuities model for optimizing profile diffuser barriers. the new multiple-impedance discontinuities model is much faster than the numerical method, thus it is used in an optimization process. the a-weighted insertion loss was used for the traffic noise spectrum. the result of optimization, which is d...
noise removal operation is commonly applied as pre-processing step before subsequent image processing tasks due to the occurrence of noise during acquisition or transmission process. a common problem in imaging systems by using cmos or ccd sensors is appearance of the salt and pepper noise. this paper presents cellular automata (ca) framework for noise removal of distorted image by the salt an...
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