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  1. Objective Cellphone ubiquity has increased distracted pedestrian behaviour and contributed to growing pedestrian injury rates. A major barrier to large-scale implementation of prevention programmes is unavailable information on potential monetary benefits. We evaluated net economic societal benefits of StreetBit, a programme that reduces distracted pedestrian behaviour by sending warnings from intersection-installed Bluetooth beacons to distracted pedestrians’ smartphones. Methods Three data sources were used as follows: (1) fatal, severe, non-severe pedestrian injury rates from Alabama’s electronic crash reporting system; (2) expected costs per fatal, severe, non-severe pedestrian injury—including medical cost, value of statistical life, work-loss cost, quality-of-life cost—from CDC and (3) prevalence of distracted walking from extant literature. We computed and compared estimated monetary costs of distracted walking in Alabama and monetary benefits from implementing StreetBit to reduce pedestrian injuries at intersections. Results Over 2019–2021, Alabama recorded an annual average of 31 fatal, 83 severe and 115 non-severe pedestrian injuries in intersections. Expected costs/injury were US$11 million, US$339 535 and US$93 877, respectively. The estimated distracted walking prevalence is 25%–40%, and StreetBit demonstrates 19.1% (95% CI 1.6% to 36.0%) reduction. These figures demonstrate potential annual cost savings from using interventions like StreetBit statewide ranging from US$18.1 to US$29 million. Potential costs range from US$3 208 600 (beacons at every-fourth urban intersection) to US$6 359 200 (every other intersection). Conclusions Even under the most parsimonious scenario (25% distracted pedestrians; densest beacon placement), StreetBit yields US$11.8 million estimated net annual benefit to society. Existing data sources can be leveraged to predict net monetary benefits of distracted pedestrian interventions like StreetBit and facilitate large-scale intervention adoption. 
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    Cities offer extensive facilities to enrich the quality of life by utilizing smart devices and sensors. The Internet of Things and smart sensors connect various city services with the inhabitants. The services should be convenient and accessible to all, especially pedestrians and people with visual impairment. However, the lack of information about service locations often limits their availability and use. To this end, we developed FinderX, a Bluetooth beacon-based system to search for the nearest services and amenities. FinderX identifies the locations of nearby amenities in real-time using the signal from attached beacons. The system does not require Internet or other communication infrastructure and can function where the GPS signal is inaccessible. To demonstrate the feasibility of FinderX, we set up a testbed and evaluated the system in an urban environment. We show that FinderX has adequate usability and feasibility and reduces the time to find the amenities by 18.98\% on average. We also demonstrate that Bluetooth beacons have lower horizontal error compared to GPS in micro-positioning (where semi-indoor or surrounding infrastructure limits signal accessibility), which motivates the use of Bluetooth beacons for such applications. 
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    The purpose of alerts and warnings is to provide necessary information to the public that will lead to their safety in emergencies. The nation’s alerting capabilities need to evolve and progress with the extensive use of smartphones, and newer technologies become available, especially to be more precisely targeted to sub-populations at risk. Historically, this has been a challenge as the delivery of alerts and warning messages to the public is primarily through broadcast media and signs. However, deploying such signs takes time and may not be visible to people imminent of natural hazards. Especially for road closing, marking hazards, emergency evacuation, etc., it would be beneficial to have an easy-to-deploy and automated alert/warning system that requires no line of sight. To this end, we have developed Insight – a Bluetooth beacon-based system that uses a smartphone application to sense signals from beacons marking hazard zones. The system does not require any Internet or communication infrastructure and therefore, it is resilient to breakdowns in communications during disasters. To demonstrate the feasibility of Insight, we conducted a study in an urban university campus location. The system demonstrated adequate usability and feasibility. 
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  5. null (Ed.)
    The safety of distracted pedestrians presents a significant public health challenge in the United States and worldwide. An estimated 6,704 American pedestrians died and over 200,000 pedestrians were injured in traffic crashes in 2018, according to the Centers for Disease Control and Prevention (CDC). This number is increasing annually and many researchers posit that distraction by smartphones is a primary reason for the increasing number of pedestrian injuries and deaths. One strategy to prevent pedestrian injuries and death is to use intrusive interruptions that warn distracted pedestrians directly on their smartphones. To this end, we developed StreetBit, a Bluetooth beacon-based mobile application that alerts distracted pedestrians with a visual and/or audio interruption when they are distracted by their smartphones and are approaching a potentially-dangerous traffic intersection. In this paper, we present the background, architecture, and operations of the StreetBit Application. 
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    The Internet of Things (IoT) devices exchange certificates and authorization tokens over the IEEE 802.15.4 radio medium that supports a Maximum Transmission Unit (MTU) of 127 bytes. However, these credentials are significantly larger than the MTU and are therefore sent in a large number of fragments. As IoT devices are resource-constrained and battery-powered, there are considerable computations and communication overheads for fragment processing both on sender and receiver devices, which limit their ability to serve real-time requests. Moreover, the fragment processing operations increase energy consumption by CPUs and radio-transceivers, which results in shorter battery life. In this article, we propose CATComp -a compression-aware authorization protocol for Constrained Application Protocol (CoAP) and Datagram Transport Layer Security (DTLS) that enables IoT devices to exchange smallsized certificates and capability tokens over the IEEE 802.15.4 media. CATComp introduces additional messages in the CoAP and DTLS handshakes that allow communicating devices to negotiate a compression method, which devices use to reduce the credentials’ sizes before sending them over an IEEE 802.15.4 link. The decrease in the size of the security materials minimizes the total number of packet fragments, communication overheads for fragment delivery, fragment processing delays, and energy consumption. As such, devices can respond to requests faster and have longer battery life. We implement a prototype of CATComp on Contiki-enabled RE-Mote IoT devices and provide a performance analysis of CATComp. The experimental results show that communication latency and energy consumption are reduced when CATComp is integrated with CoAP and DTLS. 
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