Papers by Keyword: Acoustic

Paper TitlePage

Authors: Lin Zou, De Feng Huang, Roberto Togneri
Abstract: Delay tolerance is a major design concern for supporting underwater acoustic wireless sensor networks (UA-WSNs) to carry out tasks in harsh subsea environments. Due to the great difference between the underwater acoustic channel and the radio frequency channel, most of the existing routing protocols developed for terrestrial wireless sensor networks perform poorly in underwater acoustic communications. In this work, we present a Neural-Q-Learning algorithm based delay tolerant protocol for UA-WSNs. Due to the advantages of the artificial neural network along with the Q-Learning algorithm, the ferry node is capable of determining an optimal route in a two-dimensional continuous space to relay packets effectively and efficiently between sensors. Simulation results show that the delivery delay and delivery cost of the network significantly decrease by maximizing the meeting probability between the ferry node and sensors.
Authors: Dhananjay Ghangale, Dhanesh Manik
Abstract: — Active noise control is used to reduce low frequency noises. A hybrid ANC structure combines feedforward and feedback structure to generate an anti-noise wave, which results in high performance in control of unwanted noise. In this paper, a hybrid structure for active noise control (ANC) is developed. The hybrid structure utilises a variable step size LMS algorithm for faster convergence. This structure also incorporates variable step size (VSS) online secondary path modelling, the white noise injection is stopped at the optimum point when the modelling accuracy is sufficient. Comparative simulation results shown in this paper indicate the effectiveness of the proposed approach in reducing acoustic noises.
Authors: Susilo Sidik, Azma Putra, Swee Leong Kok, Mohd Zaki Nuawi, Aswan Abdul Jalil Nawal
Abstract: Acoustic energy harvesting from ambient noise utilizing flexural vibration of a flexible panel is investigated. A flexural vibration of a flexible panel is use to extract more energy from the ambient noise level where piezoelectric materials of PVDF films are attached at the plate edges. The energy harvesting can be obtained with a maximum output power of 120 pW at the sound pressure level of 97.3 dBA.
Authors: Hong Kun Li, Jian Ding, Cheng Guo
Abstract: This paper concentrates on modeling the gear transmission system using a three-dimensional finite-element approach for the acoustic radiation analysis and control. The combination of dynamic analysis and vibration response calculation for the gear engagement system can contribute to evaluate acoustic radiation. A case study of for gear engagement system internally excited with gear mesh fluctuation is presented in this research. Acoustic radiation quantity investigation has been carried out by Virtual.Lab Acoustics software. It can be concluded that numerical simulation is very important during gear system design and noise control.
Authors: Gaurav Bharti, Dhananjay Ghangale, Dhanesh Manik
Abstract: — The performance of an ANC system depends on the convergence factor. A suitable value of convergence coefficient is extremely important as it impacts both the speed of convergence and the stability of the adaptive algorithm. Traditionally, in active noise control systems fixed convergence factor is used. In this paper, a novel approach of time-varying convergence factor μ is used and the results are compared with traditional feedforward and feedback noise control systems. This algorithm leads to faster convergence and provides reduced mean-squared error compared to the conventional fixed parameter algorithm.
Authors: Zafar Namazian, Koorosh Goudarzi
Abstract: In this paper, we investigate the effect of antenna location on aerodynamic and acoustic parameters. In order to study this, five different antenna positions are considered. The chosen positions are based on the common situation in actual cars. The finite volume numerical method is used. The obtained results show that the location of antenna at the trunk, perpendicular to the surface, produces the minimum noise.
Authors: Jiří Teslík, Naďa Zdražilová, Martina Vodičková
Abstract: With regard to the current European trends in civil engineering and sustainability are still explored new building materials. In this case it is ideal to use natural materials such as straw. Its use as a building material is both ecological and economical. Excellent thermal insulation properties of straw have been known for centuries but the aim of this paper and the measurements were also demonstrate air-tightness and acoustic properties of a straw houses in the Czech Republic.
Authors: Jiří Teslík, Naďa Zdražilová, Martina Vodičková
Abstract: Paper presents results of measuring of airtightness and acoustic properties of clay house. This clay house was built as a "SuperAdobe house" from the bags filled with clay. Construction of the clay house is a cupola. Objective of the measurement was to evaluate the quality of peripheral construction in terms of airtightness. We also wanted to verify the acoustic parameters of earthen structures and determine the value of airborne sound insulation.
Authors: Bao Kun Han, Feng Min Zheng
Abstract: As a new functional material, foam aluminum is characteristic of sound absorption and vibration attenuation. A multiple structure is put forward which composed of foam aluminum and base blankets. The sound insulation performance is investigated. The method of sound transmission loss for normal wave incidence is developed. The influences of different thick foam aluminum on the multiple structures are analyzed by numerical method, also verified by experiments. The results show that experimental results are in good agreement with the theoretical predictions and the thickness of foam aluminum has a great impact on the multiple structure’s sound transmission loss.
Authors: Tong Yue Wang, Q.P. Sun
Abstract: Vibration has a great influence on the cutting process and it can be detected by many signals. In this work, a set of experiments are conducted on Mikron UCP810 DURO high speed milling center with Fraisa carbide end mill for milling 2A12 aluminum workpiece, an acoustic method is used to detect the milling signals. The captured sound signals are analyzed using Matlab Daubechies5 wavelets with six levels of decomposition, the detail and approximation of the sound signal components are obtained. The analysis results demonstrate the relationship between the signal and the vibration.
Showing 1 to 10 of 56 Paper Titles