Slotted ALOHA Overlay on LoRaWAN: a Distributed Synchronization Approach

LoRaWAN is one of the most promising standards for IoT applications. Nevertheless, the high density of end-devices expected for each gateway, the absence of an effective synchronization scheme between gateway and end-devices, challenge the scalability of these networks. In this article, we propose to regulate the communication of LoRaWAN networks using a Slotted-ALOHA (S-ALOHA) instead of the classic ALOHA approach used by LoRa. The implementation is an overlay on top of the standard LoRaWAN; thus no modification in pre-existing LoRaWAN firmware and libraries is necessary. Our method is based on a novel distributed synchronization service that is suitable for low-cost IoT end-nodes. S-ALOHA supported by our synchronization service significantly improves the performance of traditional LoRaWAN networks regarding packet loss rate and network throughput.Comment: 4 pages, 8 figure

Older People’s Well-being Affordances at the Local High Street: A Study of Local Town Centres in Edinburgh

This paper discusses the key tenets of my research which looks at the positive health-promoting features of the public realm of local High Streets accruing to the experiential dimension of well-being in everyday life of older people. Away from functional models of ageing in place, it locates my work at the intersection between James Gibson ecological theory of perception and the salutogenic interpretive framework of people-urban public realm interaction, adapted from medical sociologist Aaron Antonovsky’s Sense of Coherence (SOC) construct (Antonovsky 1993b)(Eriksson & Lindstrӧm 2007). SOC’s three main categories: comprehensibility, manageability and meaningfulness, frames older people’s interaction with the local High Street public realm which is re-imagined as a landscape of well-being affordances. The paper explores the links between the SOC constructs and the emotional, social, cultural and physical resources these locales may afford to older people

Lightweight Synchronization Algorithm with Self-Calibration for Industrial LORA Sensor Networks

Wireless sensor and actuator networks are gaining momentum in the era of Industrial Internet of Things IIoT. The usage of the close-loop data from sensors in the manufacturing chain is extending the common monitoring scenario of the Wireless Sensors Networks WSN where data were just logged. In this paper we present an accurate timing synchronization for TDMA implemented on the state of art IoT radio, such as LoRa, that is a good solution in industrial environments for its high robustness. Experimental results show how it is possible to modulate the drift correction and keep the synchronization error within the requirements

Between Emic and Etic:A Design Pedagogy with Older People

The case study describes the pedagogy and the theoretical underpinning of an architectural design unit run in 2016 within the 3rd year “Explorations” course at the Edinburgh School of Architecture and Landscape Architecture (ESALA). The unit Domesti-city drawn on tools borrowed from visual ethnography, interaction design and psychogeography to set up an inquiry on the socio-spatial conditions affecting a specific social group: the elderly. It focused on the construction of a narrative at the intersection of the etic (students’) and emic (elderly’s) perspectives to ground design interventions in the urban context of local town centres in Edinburgh. The paper explores how the brief fostered this emic-etic connection to transcend the studio and engage outer socio – spatial reality

Low-cost and distributed health monitoring system for critical buildings

In this paper we present a low-cost distributed embedded system for Structural Health Monitoring (SHM) that uses very cost-effective MEMS accelerometers, instead of more expensive piezoelectric analog transducers. The proposed platform provides online filtering and fusion of the collected data directly on-board. Data are transmitted after processing using a WiFi transceiver. Low-cost and synchronized devices permit to have more fine-grained measurements and a comprehensive assessment of the whole building, by evaluating their response to vibrations. The challenge addressed in this paper is to execute a quite computationally-demanding digital filtering on a low-cost microcontroller STM32, and to reduce the signal-to-noise ratio typical of MEMS devices with a spatial redundancy of the sensors. Our work poses the basis for low-cost methods for elaborating complex modal analysis of buildings and structures

Older people’s everyday life and well-being at the local high street : a study of local town centres in Edinburgh

For many older people, ageing in place in a familiar environment is beneficial for their well-being, through having opportunities to access local amenities and services, to be connected to the community and to participate in local civic and social life. In spite of their perceived decline, local high streets remain valuable central and well-connected places that can foster ageing in place, yet their potential to sustain well-being in old age has been overlooked. This research explores how everyday use of local high streets supports older people’s well-being, focusing on three case studies – three local town centres – in Edinburgh. It takes a phenomenological approach to study how people interact with these places which involves structured and unstructured field observations, focus groups, and one-to-one and walking interviews with people aged 60-96. The findings illustrate that local high streets enable four key dimensions of older adults’ well-being, by helping to: reduce isolation, providing a restorative social experience away from the home; strengthen sense of place and feelings of attachment; sustain physical health and the pleasure of being out from home; and retain a sense of mastery and autonomy in the completion of everyday living activities. The research revealed aspects of local high streets in Edinburgh and more widely in Scotland that can be improved to enhance well-being in later life. Three main areas of intervention are suggested: an improved pedestrian-friendly, inclusive and walkable public realm integrated with public transport infrastructure; more proactive land use policies and place management to achieve adequate clustering of mixed uses, including social care services, community spaces and a variety of informal settings; and the promotion of town centre living for older people through accessible housing provision located next to local high streets.Heriot-Watt University scholarshi

Effects of loop corrections on string inflation

In this Master Thesis we study the effects of loop corrections to the inflationary potential of the Kahler moduli inflation model. After reviewing basic concepts of String Theory and String Compactifications, focusing in particular on the Large Volume Scenario (LVS) in Type IIB String Theory, we introduce the model of Kahler moduli inflation, and the cosmological predictions thereof. We then consider two forms of open-string loop effects: Kaluza-Klein and Winding corrections. After comparing their relative magnitude, we study the inflationary potential arising upon inclusion of these corrections. We constrain the values of the parameters for which it can still support slow-roll inflation, and find the preferred range of the compactification volume. Afterwards, we analyze the post-inflationary dynamics of the model in two possible scenarios, and find a consistent prediction for the number of e-foldings of inflation in both cases. This yields a unique prediction for the scalar spectral index, which has to be compared with the experimental value obtained considering the amount of Dark Radiation predicted by our model

A Survey of Multi-Source Energy Harvesting Systems

Energy harvesting allows low-power embedded devices to be powered from naturally-ocurring or unwanted environmental energy (e.g. light, vibration, or temperature difference). While a number of systems incorporating energy harvesters are now available commercially, they are specific to certain types of energy source. Energy availability can be a temporal as well as spatial effect. To address this issue, ‘hybrid’ energy harvesting systems combine multiple harvesters on the same platform, but the design of these systems is not straightforward. This paper surveys their design, including trade-offs affecting their efficiency, applicability, and ease of deployment. This survey, and the taxonomy of multi-source energy harvesting systems that it presents, will be of benefit to designers of future systems. Furthermore, we identify and comment upon the current and future research directions in this field

Hibernus: sustaining computation during intermittent supply for energy-harvesting systems

A key challenge to the future of energy-harvesting systems is the discontinuous power supply that is often generated. We propose a new approach, Hibernus, which enables computation to be sustained during intermittent supply. The approach has a low energy and time overhead which is achieved by reactively hibernating: saving system state only once, when power is about to be lost, and then sleeping until the supply recovers. We validate the approach experimentally on a processor with FRAM nonvolatile memory, allowing it to reactively hibernate using only energy stored in its decoupling capacitance. When compared to a recently proposed technique, the approach reduces processor time and energy overheads by 76-100% and 49-79% respectively