NFC-based user interface for smart environments

The physical support of a home automation system, joined with a simplified user-system interaction modality, may allow people affected by motor impairments or limitations, such as elderly and disabled people, to live safely and comfortably at home, by improving their autonomy and facilitating the execution of daily life tasks. The proposed solution takes advantage of the Near Field Communications technology, which is simple and intuitive to use, to enable advanced user interaction. The user can perform normal daily activities, such as lifting a gate or closing a window, through a device enabled to read NFC tags containing the commands for the home automation system. A passive Smart Panel is implemented, composed of multiple Near Field Communications tags properly programmed, to enable the execution of both individual commands and so-calledscenarios. The work compares several versions of the proposed Smart Panel, differing for interrogation and composition of the single command, number of tags, and dynamic user interaction model, at a parity of the number of commands to issue. Main conclusions are drawn from the experimental results, about the effective adoption of Near Field Communications in smart assistive environments

DSA with SHA-1 for Space Telecommand Authentication: Analysis and Results

The issue of securing Telecommand data communications in civil and commercial space missions, by means of properly located security services and primitives, has been debated within the Security Working Group of the Consultative Committee for Space Data Systems since several months. In the context of Telecommand transmissions, that can be vital in determining a successful operational behavior of a space system, the interest is mainly focused on authentication, more than encryption. The object of this paper is to investigate, under the perspective of computational overhead, the possible applicability of a standard scheme, Digital Signature Algorithm with SHA- 1, to the authentication of Telecommand data structures, and to discuss the pros and cons related to its adoption in such a peculiar context, through numerical simulations and comparison with an alternative solution relying on the widely used MD5 hash algorithm

Human Action Recognition with RGB-D Sensors

Human action recognition, also known as HAR, is at the foundation of many different applications related to behavioral analysis, surveillance, and safety, thus it has been a very active research area in the last years. The release of inexpensive RGB-D sensors fostered researchers working in this field because depth data simplify the processing of visual data that could be otherwise difficult using classic RGB devices. Furthermore, the availability of depth data allows to implement solutions that are unobtrusive and privacy preserving with respect to classic video-based analysis. In this scenario, the aim of this chapter is to review the most salient techniques for HAR based on depth signal processing, providing some details on a specific method based on temporal pyramid of key poses, evaluated on the well-known MSR Action3D dataset

Binary De Bruijn sequences for DS-CDMA systems: analysis and results

Abstract Code division multiple access (CDMA) using direct sequence (DS) spread spectrum modulation provides multiple access capability essentially thanks to the adoption of proper sequences as spreading codes. The ability of a DS-CDMA receiver to detect the desired signal relies to a great extent on the auto-correlation properties of the spreading code associated to each user; on the other hand, multi-user interference rejection depends on the cross-correlation properties of all the spreading codes in the considered set. As a consequence, the analysis of new families of spreading codes to be adopted in DS-CDMA is of great interest. This article provides results about the evaluation of specific full-length binary sequences, the De Bruijn ones, when applied as spreading codes in DS-CDMA schemes, and compares their performance to other families of spreading codes commonly used, such as m-sequences, Gold, OVSF, and Kasami sequences. While the latter sets of sequences have been specifically designed for application in multi-user communication contexts, De Bruijn sequences come from combinatorial mathematics, and have been applied in completely different scenarios. Considering the similarity of De Bruijn sequences to random sequences, we investigate the performance resulting by applying them as spreading codes. The results herein presented suggest that binary De Bruijn sequences, when properly selected, may compete with more consolidated options, and encourage further investigation activities, specifically focused on the generation of longer sequences, and the definition of correlation-based selection criteria

A Wearable Fall Detection System based on LoRa LPWAN Technology

Several technological solutions now available in the market offer the possibility of increasing the independent life of people who by age or pathologies otherwise need assistance. In particular, internet-connected wearable solutions are of considerable interest, as they allow continuous monitoring of the user. However, their use poses different challenges, from the real usability of a device that must still be worn to the performance achievable in terms of radio connectivity and battery life. The acceptability of a technology solution, by a user who would still benefit from its use, is in fact often conditioned by practical problems that impact the person’s normal lifestyle. The technological choices adopted in fact strongly determine the success of the proposed solution, as they may imply limitations both to the person who uses it and to the achievable performance. In this document, targeting the case of a fall detection sensor based on a pair of sensorized shoes, the effectiveness of a real implementation of an Internet of Things technology is examined. It is shown how alarming events, generated in a metropolitan context, are effectively sent to a supervision system through Low Power Wide Area Network technology without the need for a portable gateway. The experimental results demonstrate the effectiveness of the chosen technology, which allows the user to take advantage of the support of a wearable sensor without being forced to substantially change his lifestyle

Evaluation of a skeleton-based method for human activity recognition on a large-scale RGB-D dataset

Paper accepted for presentation at 2nd IET International Conference on Technologies for Active and Assisted Living (TechAAL), 24-25 October 2016, IET London: Savoy Place.Low cost RGB-D sensors have been used extensively in the field of Human Action Recognition. The availability of skeleton joints simplifies the process of feature extraction from depth or RGB frames, and this feature fostered the development of activity recognition algorithms using skeletons as input data. This work evaluates the performance of a skeleton-based algorithm for Human Action Recognition on a large-scale dataset. The algorithm exploits the bag of key poses method, where a sequence of skeleton features is represented as a set of key poses. A temporal pyramid is adopted to model the temporal structure of the key poses, represented using histograms. Finally, a multi-class SVM performs the classification task, obtaining promising results on the large-scale NTU RGB+D dataset.The authors would like to acknowledge the contribution of the COST Action IC1303 AAPELE (Architectures, Algorithms and Platforms for Enhanced Living Environments)

Self-Adaptive and Lightweight Real-Time Sleep Recognition With Smartphone

It is widely recognized that sleep is a basic phys- iological process having fundamental effects on human health, performance and well-being. Such evidence stimulates the re- search of solutions to foster self-awareness of personal sleeping habits, and correct living environment management policies to encourage sleep. In this context, the use of mobile technologies powered with automatic sleep recognition capabilities can be helpful, and ubiquitous computing devices like smartphones can be leveraged as proxies to unobtrusively analyse the human behaviour. To this aim, we propose a real-time sleep recognition methodology relied on a smartphone equipped with a mobile app that exploits contextual and usage information to infer sleep habits. During an initial training stage, the selected features are processed by k-Nearest Neighbors, Decision Tree, Random Forest, and Support Vector Machine classifiers, to select the best performing one. Moreover, a 1st-order Markov Chain is applied to improve the recognition performance. Experimental results, both offline in a Matlab environment, and online through a fully functional Android app, demonstrate the effectiveness of the proposed approach, achieving acceptable results in term of Precision, Recall, and F1-score

A home automation architecture based on LoRa technology and Message Queue Telemetry Transfer protocol

none5noIn recent years, Internet of Things technologies gained momentum in various application areas, including the Smart Home field. In this view, the smart objects available in the house can communicate with each other and with the outside world by adopting solutions already proposed for Internet of Things. In fact, among the challenges to face during the design and implementation of an Internet of Things–based Smart Home infrastructure, battery usage represents a key point for the realization of an efficient solution. In this context, the communication technology chosen plays a fundamental role, since transmission is generally the most energy demanding task, and Internet of Things communication technologies are designed to reduce as much as possible the power consumption. This article describes an Internet of Things-oriented architecture for the Smart Home, based on the long-range and low-power technology LoRa. Moreover, in order to enable the devices to communicate with each other and the outside world, the Message Queue Telemetry Transfer protocol is used as a domotic middleware. We show that LoRa, designed by having in mind the typical requirements of Internet of Things (i.e. low power consumption, sporadic transmission, and robustness to interference), is well-suited to also meet the need of more established home automation systems, specifically the low latency in message delivery. Interoperability among different devices may also be obtained through the Message Queue Telemetry Transfer midlleware.openEnnio Gambi, Laura Montanini, Danny Pigini, Gianluca Ciattaglia, Susanna SpinsanteGambi, Ennio; Montanini, Laura; Pigini, Danny; Ciattaglia, Gianluca; Spinsante, Susann