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Real-time noise control system for building work noise areas
Published in Manuel Martínez, Raimar Scherer, eWork and eBusiness in Architecture, Engineering and Construction, 2020
J. Gosalbez, A. Salazar, I. Bosch, J.V. Fuente, J.V. Sabater
Concerning controlling construction noise, there are several problems posed. Unlike general industry, construction activities are not always stationary and in one location. Construction activities often take place outside where they can be affected by weather, wind tunnels, topography, atmosphere and landscaping. Construction noise markers, e.g., heavy earth moving equipment, can move from location to location and is likely to vary considerably in its intensity throughout a work day. On construction worksites there are many different noise sources and these sources exhibit many different types of noise such as background noise, idling noise, blast noise, impact noise, rotating noise, intermittent noise, howling, screeches and squeals that need to be controlled. Nevertheless, the noise levels of common construction noise sources are well-known, e.g., background (86 dB average), earth moving-front end loader (85-91 dB), material handling-concrete mixer (<85 dB), crane (97–102), impact-pneumatic breaker (94-111 dB), and so on (California Public Utilities Commission 2004).
Human Factors in systems modeling
Published in Adedeji B. Badiru, Systems Engineering Models, 2019
To maximize the reliability with which important information will reach workers, work environment design must consider sensation. The work environment must be designed to maximize the clarity with which workers can sense important sources of information. Lighting must be maintained to allow workers to see at requisite accuracy levels. Effective choice of color for signs and displays can maximize contrast with backgrounds and the accuracy of interpretation. Background noise can be controlled to allow workers to hear important signals and maintain verbal communication. The frequency and loudness of auditory signals and warnings can be selected to maximize comprehension. Location is also important. Key sources of visual information should be placed within the worker’s natural line of sight.
Industrial Engineering and Human Factors
Published in Adedeji B. Badiru, The Story of Industrial Engineering, 2018
To maximize the reliability with which important information will reach workers, work environment design must consider sensation. The work environment must be designed to maximize the clarity with which workers can sense important sources of information. Lighting must be maintained to allow workers to see at requisite accuracy levels. Effective choice of color for signs and displays can maximize contrast with backgrounds and the accuracy of interpretation. Background noise can be controlled to allow workers to hear important signals and maintain verbal communication. The frequency and loudness of auditory signals and warnings can be selected to maximize comprehension. Location is also important. Key sources of visual information should be placed within the worker's natural line of sight.
Implementation and evaluation of ASHRAE’s acoustic Performance Measurement Protocols
Published in Science and Technology for the Built Environment, 2019
Gabrielle McMorrow, Liping Wang
During intermediate-level measurement, background noise and reverberation time of selected spaces are evaluated. These measurements are then compared to recommended criteria for rooms of the same space type. Background noise measurements are taken simultaneously on a range of frequencies (⅓-octave bands) using a sound-level meter. Sound pressure levels at each octave band are then used to find Noise Criteria or Room Criterion ratings. The PMP requires that background noise measurements be taken for at least four locations within a selected room. Reverberation time, the time (in seconds) that it takes for a loud noise to decay 60 dB, should also be measured at the intermediate level. A loud noise is generated, either through a loudspeaker or a hand-generated noise, such as the popping of a balloon. A sound pressure-level meter can be used to measure and calculate the reverberation time across frequencies.
Detection method based on Kalman filter for high speed rail defect AE signal on wheel-rail rolling rig
Published in Nondestructive Testing and Evaluation, 2018
Qiushi Hao, Yi Shen, Yan Wang, Xin Zhang
Figure 3 shows raw AE signal acquired at 48 km/h. Amplitude of background noise rises apparently as the speed increases, however valid signal can still be distinguished. In fact, the background noise is composed of electromagnetic noise, mechanical noise, and the noise derived from contact rolling of the two wheels. Since the rig is electric grounding, and frequency of mechanical noise is low enough for filtering, contact rolling noise counts as the main component of background noise, which varies with speed with regard to different contact situations. Continue to add the speed, a raw AE signal acquired at 78 km/h is shown in Figure 4 with amplitude of background noise up to 74.5575 mV. Noteworthily, it is the first time that the valid signal of rail defect be buried in background noise in experiments.