Patterns of sidemount four-bay FM antenna system

This paper presents the radiation characteristics of a 4-bay collinear FM antenna system, both in free-space and with the presence of a metallic tower where the bays are mounted, with the use of powerful computers and accurate antenna simulation software. The radiation characteristics of the array are presented and discussed, such as the total gain, polarization components, circularity, beamwidth and minor lobe of the array. This is to determine the conformity of the array performance with existing standards. The possible effects of the metallic tower and the downward radiation from the minor lobe are emphasized. Being aware with these radiation characteristics, broadcast practitioners can optimize the use of this popular array. Results of numerical analyses show that the array is basically a vertically polarized radiator, the beamwidth is quite small which makes it disadvantageous for high-elevated antenna systems, the metallic tower affects the circularity of the azimuth pattern, and the downward radiation from the minor lobes can cause adverse effects. Adjustments on the basic elements and bay placements are recommended

Sonification of guidance data during road crossing for people with visual impairments or blindness

In the last years several solutions were proposed to support people with visual impairments or blindness during road crossing. These solutions focus on computer vision techniques for recognizing pedestrian crosswalks and computing their relative position from the user. Instead, this contribution addresses a different problem; the design of an auditory interface that can effectively guide the user during road crossing. Two original auditory guiding modes based on data sonification are presented and compared with a guiding mode based on speech messages. Experimental evaluation shows that there is no guiding mode that is best suited for all test subjects. The average time to align and cross is not significantly different among the three guiding modes, and test subjects distribute their preferences for the best guiding mode almost uniformly among the three solutions. From the experiments it also emerges that higher effort is necessary for decoding the sonified instructions if compared to the speech instructions, and that test subjects require frequent `hints' (in the form of speech messages). Despite this, more than 2/3 of test subjects prefer one of the two guiding modes based on sonification. There are two main reasons for this: firstly, with speech messages it is harder to hear the sound of the environment, and secondly sonified messages convey information about the "quantity" of the expected movement

The in vitro influence of the burrowing polychaete Nereis diversicolor on the fate of petroleum hydrocarbons in marine sediments

The in vitro fate of the saturated hydrocarbon fraction (SF) of Arabian Light crude oil has been studied in PVC cores filled with a coastal marine sediment defaunated by sieving. Experiments were conducted in absence or presence of polychaetes Nereis diversicolor. The luminophore tracer technique was used to quantify the mixing of sediment by worms. Presence of crude oil reduced the building of burrows by polychaetes. This work demonstrates the ability of infaunal organisms to stimulate both downard and outward transfers of hydrocarbons from sediment reservoirs. In non-bioturbated sediment hydrocarbons were confined to the sediment surface. Introduction of polychaetes in sediment (1) induced the burying of SF in sediment (2.5 % and 13.5 % of the initial surface input after 15 and 45 days, respectively); (2) enhanced the exportation of SF in the overlying water (plus 59 % and 23.5 % compared to defaunated control sediment after 15 and 45 days, respectively). Buried hydrocarbons were submitted to biodegradation, from 2 cm to 10 cm depth in polychaete burrows, after 45 days

Characterization and Optimization of a Collinear Array of Circularly Polarized Side-Mounted Elements

This paper presents the radiation characteristics of a two-element collinear array of shunt-fed, slanted dipoles side-mounted to a metallic tower. It presents the radiation characteristics of the array as commonly implemented by FM broadcasters and suggests methods on how to optimize these characteristics such as the power gain, pattern circularity, side-lobe reduction, and horizontal-vertical polarization component ratio for the array to better conform to broadcast standards. By determining these characteristics using an advance antenna simulation software, optimization variables are identified, and their optimized values are determined. The optimized values lead to improved radiation characteristics of the array in conforming with broadcast requirements. Results show that adjusting the distance between the dipoles to less than one wavelength reduces the sidelobe of the array radiation pattern; varying the dipole physical specifications improves the polarization component ratio and the circularity of the radiation pattern. However, varying the dipole specifications also reduces the gain of the array. For applications requiring higher gains, other methods of realizing high collinear array gains are recommended

PlugSonic: a web- and mobile-based platform for binaural audio and sonic narratives

PlugSonic is a suite of web- and mobile-based applications for the curation and experience of binaural interactive soundscapes and sonic narratives. It was developed as part of the PLUGGY EU project (Pluggable Social Platform for Heritage Awareness and Participation) and consists of two main applications: PlugSonic Sample, to edit and apply audio effects, and PlugSonic Soundscape, to create and experience binaural soundscapes. The audio processing within PlugSonic is based on the Web Audio API and the 3D Tune-In Toolkit, while the exploration of soundscapes in a physical space is obtained using Apple's ARKit. In this paper we present the design choices, the user involvement processes and the implementation details. The main goal of PlugSonic is technology democratisation; PlugSonic users - whether institutions or citizens - are all given the instruments needed to create, process and experience 3D soundscapes and sonic narrative; without the need for specific devices, external tools (software and/or hardware), specialised knowledge or custom development. The evaluation, which was conducted with inexperienced users on three tasks - creation, curation and experience - demonstrates how PlugSonic is indeed a simple, effective, yet powerful tool

MOBILE ASSISTIVE TECHNOLOGIES FOR PEOPLE WITH VISUAL IMPAIRMENT: SENSING AND CONVEYING INFORMATION TO SUPPORT ORIENTATION, MOBILITY AND ACCESS TO IMAGES

Smartphones are accessible to persons with visual impairment or blindness (VIB): screen reader technologies, integrated with mobile operating systems, enable non-visual interaction with the device. Also, features like GPS receivers, inertial sensors and cameras enable the development of Mobile Assistive Technologies (MATs) to support people with VIB. A preliminary analysis, conducted adopting an user-centric approach, highlighted some issues experienced by people with VIB in everyday activities from three main fields: orientation, mobility and access to images. Traditional approaches to address these issues, based on assistive tools and technologies, have some limitations: in the field of mobility, for example, existing navigation support solutions (e.g. the white cane) cannot be used to perceive some environmental features like crosswalks or the current state of traffic lights; in the field of orientation, tactile maps adopted to develop cognitive maps of the environment are limited in the amount of information that can be represented on a single surface and by the lack of interactivity, two issues experienced also in other fields where access to graphical information is of paramount importance like, for example, didactics of STEM subjects. This work presents new MATs that deal with these limitations by introducing novel solutions in different fields of Computer Science. Original computer vision techniques, designed to detect the presence of pedestrian crossings and the state of traffic lights, are used to sense information from the environment and support mobility of people with VIB. Novel sonification techniques are introduced to efficiently convey information with three different goals: first, to convey guidance information in urban crossings; second, to enhance the development of cognitive maps by augmenting tactile surfaces; third, to enable quick access to images. Experience reported in this dissertation shows that the proposed MATs are effective in supporting people with VIB and, in general, that mobile devices are a versatile platform to enable affordable and pervasive access to assistive technologies. Involving target users in the evaluation of MATs emerged as a major challenge in this work. However, it is shown how such challenge can be addressed by adopting large scale evaluation techniques typical of HCI research

Design and evaluation of a web-and mobile-based binaural audio platform for cultural heritage

PlugSonic is a suite of web- and mobile-based applications for the curation and experience of 3D interactive soundscapes and sonic narratives in the cultural heritage context. It was developed as part of the PLUGGY EU project (Pluggable Social Platform for Heritage Awareness and Participation) and consists of two main applications: PlugSonic Sample, to edit and apply audio effects, and PlugSonic Soundscape, to create and experience 3D soundscapes for headphones playback. The audio processing within PlugSonic is based on the Web Audio API and the 3D Tune-In Toolkit, while the mobile exploration of soundscapes in a physical space is obtained using Apple’s ARKit. The main goal of PlugSonic is technology democratisation; PlugSonic users-whether cultural institutions or citizens-are all given the instruments needed to create, process and experience 3D soundscapes and sonic narratives; without the need for specific devices, external tools (software and/or hardware), specialised knowledge or custom development. The aims of this paper are to present the design and development choices, the user involvement processes as well as a final evaluation conducted with inexperienced users on three tasks (creation, curation and experience), demonstrating how PlugSonic is indeed a simple, effective, yet powerful tool

Loneliness, Resilience, Mental Health, and Quality of Life in Old Age: A Structural Equation Model

In the scientific literature on aging, a recent core issue has been the role of individuals' internal and external resources, which are considered intrinsically connected, in contributing synergistically to physical and psychological quality of life (QoL). The current study investigates the way in which psychological factors—such as, loneliness, resilience, and mental states, in terms of depression and anxiety symptoms—affect the perceived QoL among elderly individuals

Loneliness, Resilience, Mental Health, and Quality of Life in Old Age: A Structural Equation Model

In the scientific literature on aging, a recent core issue has been the role of individuals' internal and external resources, which are considered intrinsically connected, in contributing synergistically to physical and psychological quality of life (QoL). The current study investigates the way in which psychological factors—such as, loneliness, resilience, and mental states, in terms of depression and anxiety symptoms—affect the perceived QoL among elderly individuals