Annoyance of helicopter impulsive noise

Psychoacoustic studies of helicopter impulsive noise were conducted in order to qualify additional annoyance due to this feature and to develop physical impulsiveness descriptors to develop impulsivity correction methods. The currently proposed descriptors and methods of impulsiveness correction are compared using a multilinear regression analysis technique. It is shown that the presently recommended descriptor and correction method provides the best correlation with the subjective evaluations of real helicopter impulsive noises. The equipment necessary for data processing in order to apply the correction method is discussed

A taxonomical framework of socio-cultural hazards in transport hubs

This article presents a taxonomical framework that supports the considerations of socio-cultural hazards that may affect crowd management in transport hubs, i.e. airports, ports, underground and train stations, both in normal and emergency situations. Such hazards include communication breakdowns with passengers due, for instance, to language barriers; increased potential for revolts, as in stranded passenger situations; misreporting of security threats; and uncooperative behaviour in case of emergencies. Such socio-cultural hazards are not normally considered from the integrated perspective of transport hub operators, e.g. security staff, first responders and service assistants as well as safety and security managers. The present study provides an integrated perspective of these hazards as a means to increase the performance of transport staff members that interact with the public and with passengers on a daily basis. The methodology used to develop the framework comprises: (i) a focus group with relevant experts, (ii) semi-structured interviews at operational facilities with front-end practitioners, and (iii) a review of academic literature and media reports. The framework has also been qualitatively corroborated with transport operators in dedicated interviews and a focus group session. The study identified 10 socio-cultural hazards that were combined into a single framework comprising three high-level sub-categories: (i) crowd–staff interactions, (ii) crowd–crowd interactions, and (iii) crowd–environment interactions. The framework of socio-cultural factors can increase staff’s awareness of relevant socio-cultural hazards, their potential consequences in both normal and emergency situations, and the associated mitigation strategies. In turn, this can increase the quality and continuity of service, safety and security in the management of members of the public and passengers in transport hubs

Natural language processing for aviation safety: Extracting knowledge from publicly-available loss of separation reports

Background: The air traffic management (ATM) system has historically coped with a global increase in traffic demand ultimately leading to increased operational complexity. When dealing with the impact of this increasing complexity on system safety it is crucial to automatically analyse the losses of separation (LoSs) using tools able to extract meaningful and actionable information from safety reports. Current research in this field mainly exploits natural language processing (NLP) to categorise the reports,with the limitations that the considered categories need to be manually annotated by experts and that general taxonomies are seldom exploited. Methods: To address the current gaps,authors propose to perform exploratory data analysis on safety reports combining state-of-the-art techniques like topic modelling and clustering and then to develop an algorithm able to extract the Toolkit for ATM Occurrence Investigation (TOKAI) taxonomy factors from the free-text safety reports based on syntactic analysis. TOKAI is a tool for investigation developed by EUROCONTROL and its taxonomy is intended to become a standard and harmonised approach to future investigations. Results: Leveraging on the LoS events reported in the public databases of the Comisión de Estudio y Análisis de Notificaciones de Incidentes de Tránsito Aéreo and the United Kingdom Airprox Board,authors show how their proposal is able to automatically extract meaningful and actionable information from safety reports,other than to classify their content according to the TOKAI taxonomy. The quality of the approach is also indirectly validated by checking the connection between the identified factors and the main contributor of the incidents. Conclusions: Authors' results are a promising first step toward the full automation of a general analysis of LoS reports supported by results on real-world data coming from two different sources. In the future,authors' proposal could be extended to other taxonomies or tailored to identify factors to be included in the safety taxonomies

Adherence issues related to sublingual immunotherapy as perceived by allergists

Objectives: Sublingual immunotherapy (SLIT) is a viable alternative to subcutaneous immunotherapy to treat allergic rhinitis and asthma, and is widely used in clinical practice in many European countries. The clinical efficacy of SLIT has been established in a number of clinical trials and meta-analyses. However, because SLIT is self-administered by patients without medical supervision, the degree of patient adherence with treatment is still a concern. The objective of this study was to evaluate the perception by allergists of issues related to SLIT adherence. Methods: We performed a questionnaire-based survey of 296 Italian allergists, based on the adherence issues known from previous studies. The perception of importance of each item was assessed by a VAS scale ranging from 0 to 10. Results: Patient perception of clinical efficacy was considered the most important factor (ranked 1 by 54% of allergists), followed by the possibility of reimbursement (ranked 1 by 34%), and by the absence of side effects (ranked 1 by 21%). Patient education, regular follow-up, and ease of use of SLIT were ranked first by less than 20% of allergists. Conclusion: These findings indicate that clinical efficacy, cost, and side effects are perceived as the major issues influencing patient adherence to SLIT, and that further improvement of adherence is likely to be achieved by improving the patient information provided by prescribers. © 2010 Scurati et al, publisher and licensee Dove Medical Press Ltd

Time-invariant filtering and segmentation of SAR images by using mean-field annealing

A stochastic model for restoration of and edge extraction from synthetic aperture radar (SAR) images is presented. This model is based on an observation-prediction model which favors the restoration of piecewise-constant patches separated by long continuous edges. Speckle noise is filtered out by means of an a-priori fixed probability distribution dependent on the number of views. Results on synthetic and real images are reported. To reduce the computational cost, simulated annealing is replaced with a deterministic algorithm based on the weak membrane model and on the mean field equations adapted to SAR

Remote sensing data fusion by means of a region-overlapping technique

An approach to data fusion, based on the overlapping of regions from two or more different channels and on a fuzzy reasoning about the result of the overlapping process, is introduced. Resulting regions are labeled as slivers (regions created by imperfect boundary superimposition) and kernels (all remaining regions). Kernels are classified by a matching with multisensor models, while for slivers a more complex reasoning is necessary to take into account their source (misregistration, segmentation error, or temporal change). The region-overlapping technique is described, and its potentialities are assessed. Experimental results on multitemporal TM (Thermatic Mapper) images are shown, including the multichannel segmented image produced by overlapping, and kernel/sliver distinction

Variability of underwater radiated ship noise measured using two hydrophone arrays

The Impacts of man-made underwater noise on the marine environment have received increased attention over recent years, primarily resulting from recognition of the increased pressures placed on the oceans by human activities. Underwater noise from shipping has long been acknowledged as a major contributor to overall ambient sea noise levels. Furthermore, recent evidence from long term measurements at a deep water location suggest that the increase in global merchant shipping has led to an increase in ambient noise levels in the oceans (although it should be noted that the data also show that this trend may be levelling off).To date, measurements of radiated noise from ships have been carried out primarily at fixed noise ranges. However, in recent years researchers have increasingly used other systems, most commonly portable measurement systems deployed from support vessels. The use of various bespoke or proprietary measurement systems and the various ways of reporting the data in the literature has prompted the recent publication of national and international standards covering measurement and data processing methodologies. These standards cover in detail many aspects of full scale ship radiated noise measurements including the measurement system specification, target vessel operating sequence and trials location requirements as well as the processing, analysis and reporting of the data. The objective of this paper is to present some analysis of measured radiated underwater noise data from a small vessel operating under realistic test conditions at sea in shallow water undertaken as part of the SONIC project. The measurements followed the requirements of the published standards as closely as possible although it was not possible to meet all of the criteria. Two multiple hydrophone arrays operated by two of the project partners, CETENA and the University of Southampton, were deployed from the same moored support vessel over a period of several days. The comparison of the data from these two systems provides an opportunity to investigate the typical variability and repeatability of radiated underwater noise from ships using mobile arrays.<br/