THE CONTRIBUTION OF CRUISE SHIPS TO THE SOUND EMISSION OF A HARBOUR

In recent years, the growth of cruise tourism has often been at the centre of controversy due to the environmental impact, especially for those harbours that, for historical and urban planning reasons, are in close contact with urban areas of particular value or under cultural heritage protection. The deadlock of cruise activities due to the COVID-19 pandemic emergency created the conditions for observing the effects of the substantial disappearance of a specific sound source from the harbours of many cities. This paper presents the evaluation of the contribution of large cruise ships to the overall noise emitted by a specialized cruise harbour and the consequences of their absence on the urban acoustic climate. © International Institute of Acoustics and Vibration (IIAV), 2022.

MEMs Based Low-Cost Urban Noise Monitoring: Tests and Case Study

Noise pollution has been one of the main causes of citizens' discomfort in the urban centers in Brazil, an issue enhanced by the Covid pandemic that resulted in an increase of noise complaints, especially those related to noise from construction sites. This context triggered the construction industry to pursue solutions to understand the acoustic reality and minimize the impacts through regulations that require long-term noise measurements. Due to the necessity of a comprehensive evaluation in several locations, class 1 Sound Level Meters measurement systems can hardly be considered because of their high costs. This paper discusses the practical implementation of MEMs in a low-cost monitoring system for urban noise, focusing on construction sites. The prototype, based on a Raspberry Pi (a single-board computer model widely used in IoT projects) and a MEMs microphone with I2S interface for high-fidelity digital audio communication, was compared in a controlled environment to a Sound Level Meter of Class 1 through validation tests, such as calibration, frequency response, and dynamic range. Field measurements were also carried out in typical urban noise-generating sound environments. © 2022 Internoise 2022 - 51st International Congress and Exposition on Noise Control Engineering. All rights reserved.

Adaptive Group Testing on Networks with Community Structure: The Stochastic Block Model

Group testing was conceived during World War II to identify soldiers infected with syphilis using as few tests as possible, and it has attracted renewed interest during the COVID-19 pandemic. A long-standing assumption in the probabilistic variant of the group testing problem is that individuals are infected by the disease independently. However, this assumption rarely holds in practice, as diseases often spread through interactions between individuals and therefore cause infections to be correlated. Inspired by characteristics of COVID-19 and other infectious diseases, we introduce an infection model over networks which generalizes the traditional i.i.d. model from probabilistic group testing. Under this model, we ask whether knowledge of the network structure can be leveraged to perform group testing more efficiently, focusing specifically on community-structured graphs drawn from the stochastic block model. We prove that a simple community-aware algorithm outperforms the baseline binary splitting algorithm when the model parameters are conducive to “strong community structure.”Moreover, our novel lower bounds imply that the community-aware algorithm is order-optimal in certain parameter regimes. We extend our bounds to the noisy setting and support our results with numerical experiments. IEEE

Airborne Sound Power Levels and Spectra of Noise Sources in Port Areas.

Airborne port noise has historically suffered from a lack of regulatory assessment compared to other transport infrastructures. This has led to several complaints from citizens living in the urban areas surrounding ports, which is a very common situation, especially in countries facing the Mediterranean sea. Only in relatively recent years has an effort been made to improve this situation, which has resulted in a call for and financing of numerous international cooperation research projects, within the framework of programs such as EU FP7, H2020, ENPI-CBC MED, LIFE, and INTERREG. These projects dealt with issues and aspects of port noise, which is an intrinsically tangled problem, since several authorities and companies operate within the borders of ports, and several different noise sources are present at the same time. In addition, ship classification societies have recently recognized the problem and nowadays are developing procedures and voluntary notations to assess the airborne noise emission from marine vessels. The present work summarizes the recent results of research regarding port noise sources in order to provide a comprehensive database of sources that can be easily used, for example, as an input to the noise mapping phase, and can subsequently prevent citizens' exposure to noise.

Recovery Algorithms for Pooled RT-qPCR based Covid-19 Screening

We consider the problem of sparse signal recovery in a non-adaptive pool-test setting using quantitative measurements from a non-linear model. The quantitative measurements are obtained using the reverse transcription (quantitative) polymerase chain reaction (RT-qPCR) test, which is the standard test used to detect Covid-19. Each quantitative measurement refers to the cycle threshold, a proxy for the viral load in the test sample. We propose two novel, robust recovery algorithms based on alternating direction method of multipliers and block coordinate descent to recover the individual sample cycle thresholds and hence determine the sick individuals, given the pooled sample cycle thresholds and the pooling matrix. We numerically evaluate the normalized mean squared error, false positive rate, false negative rate, and the maximum sparsity levels up to which error-free recovery is possible. We also demonstrate the advantage of using quantitative measurements (as opposed to binary outcomes) in non-adaptive pool testing methods in terms of the testing rate using publicly available data on Covid-19 testing. The simulation results show the effectiveness of the proposed algorithms. IEEE

Determination of Annual Environmental Noise Indicators Using a Series of Short-Term Measurements

Completely reliable annual values of environmental noise indicators can be obtained only through continuous annual noise measurements. This paper examines the justification of using a series of short-term measurements to determine the annual values of environmental noise indicators. The examination involves the application of a proposed measurement program to the results of continuous annual noise monitoring at two locations in the city of Niš, Serbia, in which road traffic is the dominant noise source. Monitoring results include the period when the state of emergency was in effect because of the Covid-19 pandemic. The obtained results indicate that using the proposed program is fully justified if the goal is to define annual environmental noise indicator values for specific cases only. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.