Using Bluetooth Low Energy devices to monitor visitor activity in remote amenity spaces

Tracking of pedestrian behaviour, particularly route selection and temporal behaviours, can be difficult to undertake. This is especially true of studies at a community or campus level where the anonymity of pedestrians can be difficult to protect. The introduction of the EU’s General Data Protection Regulations 2016 (GDPR) has increased the complexity of this challenge. Advances in Bluetooth Low Energy (BLE) technology in recent years have increased the potential to monitor human behaviour by tracking and triangulating pedestrians. This paper describes an experiment undertaken along The Great South Wall at the Port of Dublin, which is considered a leading amenity location. Monitoring of visitor behaviour in places of this type can provide valuable information about the use of this and other public resources. The aims of this study were to test two prototypes to: i) determine the direction of participants carrying BLE devices, ii) determine the capabilities of two BLE scanning prototypes, (ESP32 & Raspberry Pi3), iii) test the ability of detecting a small number of BLE devices simultaneously while minimising interference or loss of passers-by data, iv) to investigate the use of a hash encoding scheme to anonymise BLE device identifiers. The findings show that the direction of the visitors to the pier can be detected by correlating the received signal strength indicator (RSSI) from multiple Bluetooth scanning devices and this can work where scanning devices are as close as 10m apart. The locations of the BLE scanners has a slight effect on detecting the RSSI from different distances and the distance between scanners needs to be considered to facilitate accurate measurement of direction. As a pier like the South Wall has only one entrance and exit point, this approach can also be used to determine the length of time spent on the pier. The technical performance of the two BLE scanners was also reviewed and the ESP32 was shown to have significantly lower power consumption with only a slight decrease in performance. Finally, it was shown that the BLE scanners can detect multiple carried BLE devices successfully without interference or loss of data as long as those devices are within range of the BLE scanners

Two Paths to Transforming Markets through Public Sector Energy Efficiency: Bottom Up versus Top Down

ABSTRACT The evolution of government purchasing initiatives in Mexico and China, part of the PEPS (Promoting an Energy-efficient Public Sector) program, demonstrates the need for flexibility in designing energy-efficiency strategies in the public sector. Several years of pursuing a top-down (federally led) strategy in Mexico produced few results, and it was not until the program was restructured in 2004 to focus on municipal-level purchasing that the program gained momentum. Today, a new partnership with the Mexican federal government is leading to an intergovernmental initiative with strong support at the federal level. By contrast, the PEPS purchasing initiative in China was successfully initiated and led at the central government level with strategic support from international experts. The very different success trajectories in these two countries provide valuable lessons for designing country-specific public sector energy-efficiency initiatives. Enabling conditions for any successful public sector purchasing initiative include the existence of mandatory energyefficiency performance standards, an effective energy-efficiency endorsement labeling program, an immediate need for energy conservation, a simple pilot phase (focusing on a limited number of strategically chosen products), and specialized technical assistance. Top-down purchasing programs are likely to be more successful where there is high-level political endorsement and a national procurement law in place, supported by a network of trained purchasers. Bottom-up (municipally led) purchasing programs require that municipalities have the authority to set their own purchasing policies, and also benefit from existing networks of cities, supported by motivated municipal leaders and trained purchasing officials

Model selection and parameter estimation in structural dynamics using approximate Bayesian computation

This paper will introduce the use of the approximate Bayesian computation (ABC) algorithm for model selection and parameter estimation in structural dynamics. ABC is a likelihood-free method typically used when the likelihood function is either intractable or cannot be approached in a closed form. To circumvent the evaluation of the likelihood function, simulation from a forward model is at the core of the ABC algorithm. The algorithm offers the possibility to use different metrics and summary statistics representative of the data to carry out Bayesian inference. The efficacy of the algorithm in structural dynamics is demonstrated through three different illustrative examples of nonlinear system identification: cubic and cubic-quintic models, the Bouc-Wen model and the Duffing oscillator. The obtained results suggest that ABC is a promising alternative to deal with model selection and parameter estimation issues, specifically for systems with complex behaviours

Women and ARVâ based prevention: opportunities and challenges

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138349/1/jia29419.pd