This paper introduces a weighted context-based step length estimation algorithm for pedestrian dead reckoning. Six pedestrian contexts are considered: stationary, walking, walking sideways, climbing and descending stairs, and running. Instead of computing the step length based on a single context, the step lengths computed for different contexts are weighted by the context probabilities. This provides more robust performance when the context is uncertain. The proposed step length estimation algorithm is part of a pedestrian dead reckoning system which includes the procedures of step detection and context classification. The step detection algorithm detects the step time boundaries using continuous wavelet transform analysis, while the context classification algorithm determines the pedestrian context probabilities using a relevance vector machine. In order to assess the performance of the pedestrian dead reckoning system, a dataset of pedestrian activities and actions has been collected. Fifteen subjects have been equipped with a waist-belt smartphone and traveled along a predefined path. Acceleration, angular rate and magnetic field data were recorded. The results show that the traveled distance is more accurate using step lengths weighted by the context probabilities compared to using step lengths based on the highest probability context.

The biocompatibility and nanoscale features of Molecular Communication (MC) make this paradigm, based on molecules and chemical reactions, an enabler for communication theory applications in the healthcare at its biological level (e.g., bimolecular disease detection/monitoring and intelligent drug delivery). However, the adoption of MC-based innovative solutions into privacy and security-sensitive areas is opening new challenges for this research field. Despite fundamentals of information theory applied to MC have been established in the last decade, research work on security in MC systems is still limited. In contrast to previous literature focused on challenges, and potential roadmaps to secure MC, this paper presents the preliminary elements of a systematic approach to quantifying information security as it propagates through an MC link. In particular, a closed-form mathematical expression for the secrecy capacity of an MC system based on free molecule diffusion is provided. Numerical results highlight the dependence of the secrecy capacity on the average thermodynamic transmit power, the eavesdropper's distance, the transmitted signal bandwidth, and the receiver radius. In addition, the concept of secure distance in an MC system is introduced and investigated for two different techniques of signal detection, i.e., based on energy and amplitude. The secrecy capacity can be used to determine how much secure information (bit/sec/Hz) can be exchanged and within which operative range, while the secure distance can be used to set the transmit power to obtain a secure channel at a given distance. We envision these metrics will be of utmost importance for a future design framework tailored to MC systems and their practical applications.

Roads are a strategic asset of a country and are of great importance for the movement of passengers and goods. Increasing traffic volume and load, together with the aging of roads, creates various types of anomalies on the road surface. This work proposes a low-cost system for real-time screening of road pavement conditions. Acceleration signals provided by on-car sensors are processed in the time–frequency domain in order to extract information about the condition of the road surface. More specifically, a short-time Fourier transform is used, and significant features, such as the coefficient of variation and the entropy computed over the energy of segments of the signal, are exploited to distinguish between well-localized pavement distresses caused by potholes and manhole covers and spread distress due to fatigue cracking and rutting. The extracted features are fed to supervised machine learning classifiers in order to distinguish the pavement distresses. System performance is assessed using real data, collected by sensors located on the car’s dashboard and floorboard and manually labeled. The experimental results show that the proposed system is effective at detecting the presence and the type of distress with high classification rates.

The present study investigates whether different directions and tensions of Kinesio^® Tex tape (KT) application differently influence the precision of sensorimotor synchronization, defined as the ability to coordinate actions with predictable external events. 10 healthy participants performed sets of repetitive wrist flexion-extensions synchronized to a series of paced audio stimuli with an inter-onset interval (IOI) of 500 and 400 ms. KT was applied over the wrist and finger extensor muscles. 2 facilitatory (light and moderate tension) and one inhibitory KT applications were used in different sessions. Standard deviation of the asynchrony (SDasy) and percentage difference of SDasy were calculated and compared across KT and the no-KT control cases. Direction and tension of KT application did not differently influence the ability to coordinate rhythmic movements to an auditory stimulus. However, compared with the no-KT control case, SDasy decreased significantly in all KT cases in both 500- and 400-ms IOI. Independent of direction/tension, the effect of KT on improving sensorimotor synchronization is likely associated with variations in the nature of the neuro-anatomical constraints determining the control of voluntary movement. KT is then proposed to be tested on sensorimotor disorders associated with intense repetitive exercise to check for regaining effective motor control.

WBANs are envisioned as a key technology for enabling health services in the very next future. A body-centered system relying on the collection of information from sensors placed in or on the body and the transmission of this data to the cloud medical server requires new security solutions. Security for communication within the body is still a less investigated area that needs to be addressed due to the challenging limited resources of the involved nodes. Starting both from the analysis of the most critical communication links of the WBAN reference architecture and from the security threats and requirements, an overview of the state-of-the-art of the security challenges and solutions for WBAN applications is presented.

An innovative wireless sensor network (WSN) based on Ultra-Wide Band (UWB) technology for 3D accurate superficial monitoring of ground deformations, as landslides and subsidence, is proposed. The system has been designed and developed as part of an European Life+ project, called Wi-GIM (Wireless Sensor Network for Ground Instability Monitoring). The details of the architecture, the localization via wireless technology and data processing protocols are described. The flexibility and accuracy achieved by the UWB two-way ranging technique is analysed and compared with the traditional systems, such as robotic total stations (RTSs) and Ground-based Interferometric Synthetic Aperture Radar (GB-InSAR), highlighting the pros and cons of the UWB solution to detect the surface movements. An extensive field trial campaign allows the validation of the system and the analysis of its sensitivity to different factors (e.g., sensor nodes inter-visibility, effects of the temperature, etc.). The Wi-GIM system represents a promising solution for landslide monitoring and it can be adopted in combination with traditional systems or as an alternative in areas where the available resources are inadequate. The versatility, easy/fast deployment and cost-effectiveness, together with good accuracy, make the Wi-GIM system a possible solution for municipalities that cannot afford expensive/complex systems to monitor potential landslides in their territory.