A social network often has numerous interesting attributes. When an attribute is quantified, a social tomography would arise from the underlying social network. One of the most interesting attributes is crime hotspots, whose existence has been strongly supported by observations that serious crimes ranging from residential burglary to homicide are strongly patterned in time and space, and by mathematical modeling. So far, however, the structures of hotspots, including their size distributions, have not been adequately studied. Here, we focus on a special type of hotspots, the sex offender clusters, in the United States, and show that their size distribution, where size is defined as the ratio between sex offender population and total population in a 5-digit zip code area, follows a power-law distribution. In contrast, such local total population, both general and sex offenders, do not quite follow power-laws. A heavy-tailed power-law distribution is fundamentally different from a thin-tailed distribution such as a Poisson distribution, and can be used as an objective criterion for defining sex offender clusters. More fundamentally, a power-law is a defining property of self-similarity or fractal behavior. Therefore, our finding indicates that sex offender clusters, size-wise, self-organize into a fractal, due to interplay of economic conditions of offenders, policies and public perceptions.

Patterns of animate and inanimate systems show remarkable similarities in their aggregation. One similarity is the double-Pareto distribution of the aggregate-size of system components. Different models have been developed to predict aggregates of system components. However, not many models have been developed to describe probabilistically the aggregate-size distribution of any system regardless of the intrinsic and extrinsic drivers of the aggregation process. Here we consider natural animate systems, from one of the greatest mammals - the African elephant (Loxodonta africana) - to the Escherichia coli bacteria, and natural inanimate systems in river basins. Considering aggregates as islands and their perimeter as a curve mirroring the sculpting network of the system, the probability of exceedence of the drainage area, and the Hack’s law are shown to be the the Korˇcak’s law and the perimeter-area relationship for river basins. The perimeter-area relationship, and the probability of exceedence of the aggregate-size provide a meaningful estimate of the same fractal dimension. Systems aggregate because of the influence exerted by a physical or processes network within the system domain. The aggregate-size distribution is accurately derived using the null-method of box-counting on the occurrences of system components. The importance of the aggregate-size spectrum relies on its ability to reveal system form, function, and dynamics also as a function of other coupled systems. Variations of the fractal dimension and of the aggregate-size distribution are related to changes of systems that are meaningful to monitor because potentially critical for these systems.

An introduction to the key topics in the cognitive science of cyber defence analysis including an overview of the challenges that exist and need to be faced in the field.

The advent of technologies that can seamlessly operate in different environments with differing levels of security present new challenges to the cybersecurity specialist seeking to ensure the safety of data, process or output of a complex system. This paper reviews the human dimension of cybersecurity. The Human Factors Integration (HFI) framework is employed as a structure with which to consider the many ways in which the human can differentially affect the security of a system both positively and negatively. We conclude that when the human factors element is analysed when specifying and designing secure and safe systems, it is far more likely that the human can assist and increase the overall level of security. As in other high technology sectors such as aviation or petrochemical, if not considered, the human can often ‘bulldoze’ through the most carefully considered and designed security or safety barriers

Future conflicts will necessitate the ability to conduct effective military operations in a contested information environment. The building and maintaining of robust situational awareness, protection of decision-making effectiveness of individuals and teams, fighting through information attacks from both in, and through, the cyberspace domain, will be essential. Increasing the knowledge of the mechanisms involved in degrading task performance and decision-making during cyber attacks will enable the development of advanced human-centered defensive techniques that aid fight-through capability. In this position paper, the development and evaluation of software that simulates real-time and persistent manipulation of the information environment is discussed. Results of the evaluation indicated that the task performance of a team of decision-makers performing collaborative tasks could be degraded through real-time manipulation of cyberspace content and operation. The paper concludes with a discussion of focus and direction for future research and development. It is suggested that the building of a deeper understanding of the perceptual and cognitive factors that are significant in the relationship between information environment manipulation and reduction in task performance is required. This understanding will aid in the defence of cyberspace attacks, will aid in fight through and mission assurance, and will aid the Information Operations community.

Cyber insider threat is intentional theft from, or sabotage of, a cyber system by someone within the organization. This article explores the use of advanced cognitive and instructional principles to accelerate learning in organizational supervisors to mitigate the cyber threat. It examines the potential advantage of using serious games to engage supervisors. It also posits two systematic instructional approaches for this training challenge – optimal path modelling and a competency-based approach. The paper concludes by discussing challenges of evaluating training for seldom occurring real world phenomena, like detecting a cyber-insider threat.

Cyber analysis is a complex task that requires the coordination of a large sociotechnical system of human analysts working together with technology. Adequate situation awareness of such a complex system requires more than aggregate situation awareness of individuals. Teamwork in the form of communication and information coordination is at the heart of team-level situation awareness. In this position paper, we report observations from previously conducted cognitive task analyses that suggest that teamwork is lacking in many cyber analysis organizations. Communication is ineffective, team roles are inconsistent across organizations, reward structures and selection may thwart collaboration, and the environment is conducive to individual work. Suggestions for improving teamwork in the cyber domain are offered.

In this paper we argue for a human-in-the-loop approach to the study of situation awareness in computer defence analysis (CDA). The cognitive phenomenon of situation awareness (SA) has received significant attention in cybersecurity/CDA research. Yet little of this work has attended to the cognitive aspects of situation awareness in the CDA context; instead, the human operator has been treated as an abstraction within the larger human-technology system. A more human-centric approach that seeks to understand the socio-cognitive work of human operators as they perform CDA will yield greater insights into the design of tools and interfaces for CDA. As support for this argument, we present our own work employing the Living Lab Framework through which we ground our experimental findings in contextual knowledge of real-world practice.

Antenna design for footwear is an essential part of enabling reliable wireless links with lower-limb sensors used in body centric networks. Sensors can report biomechanical pressure data to analyse kinematic and posture parameters for a range of medical and sporting applications. Consideration is given to antenna shapes, the fit with shoe shapes, the positioning on the shoe and the radiation patterns suited to on body and off-body communications.

Cardiopulmonary information can be extracted from the temporal variations of the input reflection coefficient of a single wearable antenna placed in close proximity of the human thorax. In a previous paper, the authors have shown the potentials of such non-invasive measurement technique through experimental results; as a proof of concept, phase samples were collected by using a Vector Network Analyzer, and conventional non-linear filtering techniques were used to isolate the spectral components related to heartbeat and respiration rate. To get more realistic measurement data, a first prototype of a low-cost RF sensor has been implemented, and improved algorithms have been developed to estimate both heartbeat and breathing rate. Preliminary measurement results are shown to validate the approach, and the effects of the human body movements are discussed.

The radio propagation signal between a pair of low-power wireless sensor nodes is analysed with the aim to identify and retrieve embedded physiological features. The latter is post-processed using popular time-frequency analyses, such as such as the Fast Fourier transform (FFT). The results show initial evidence that the electromagnetic wave propagation contains bio-mechanical markers, such as gait pattern and thoracic displacements.

Body Sensor Networks are an interesting emerging application to improve healthcare and the quality of life monitoring. In this paper, we compare the performances of multi-hop cooperative and single-hop networks with real-world sensor networks based on Zigbee technology. The network reliability, the data flow rate, the packet delivery ratio and the energy consumption are included as performances criteria. It is shown experimentally that the cooperative approach can provide a network more robust to link losses at the expenses of a lower bit rate and higher energy consumption. Specifically, for a packet delivery ratio >0.9, the cooperative scheme can provide the network with a link gain up to 14 dB traded off with an energy demand up to 30.7% higher and a data flow rate about 20% lower than a single-hop system. This work is a first exercise step in assessing reliability and life time trade-off with real-world platforms for body area sensor networks. Follow-up studies will address wireless ECG emulators with higher number of sensors (e.g. up to 10 for a typical 12-leads ECG system) employing ultra-low power chipsets in different specific health monitoring environments.

We present a novel respiratory sounds monitoring concept based on compressive sensing (CS). Respiratory sounds are streamed from a body-worn sensor node to a smartphone where processing is conducted. CS is used to simultaneously lower sampling frequency on the sensor node and over-the-air data rate. In this study we emphasize compressed sensing reconstruction via orthogonal matching pursuit (OMP) on Android smartphone. Accuracy of the reconstruction and execution speed are investigated using synthetic signals. We demonstrate applicability of the technique in real-time reconstruction of at least 10 components of compressible DCT spectrum of respiratory sounds containing asthmatic wheezing, acquired at 4x lower sampling rate.

In this article, we present two studies that pave the way towards a mobile implementation of the WAAVES certified medical image compression encoder. On the algorithmic side, we compared three techniques to increase the compression rate. The obtained results show a significant bit-rate reduction, around 40% with respect to the WAAVES encoder, while keeping the same visual quality. On the architectural side, we describe the HW/SW co-design of an architecture implemented in a FPGA platform. By using code profiling, critical portions of the code were identified, then two methods for hardware acceleration were used to implement the critical part of the coder. The tests were done on a StratixIVGX230 FPGA and the results showed that HW/SW co-design could achieve up to 20x performance gain in the critical portion. The combination of these results demonstrates the feasibility of a mobile implementation of the WAAVES certified medical image coder suitable for e-health applications.

Physical inactivity is nowadays defined as the fourth leading risk factor for global mortality. These levels are rising worldwide with major aftereffects on the prevention of several diseases and the general health of the population. Energy expenditure (EE) is a very important parameter usually used as a dimension in physical activity assessment studies. However, the most accurate methods for the measurement of the EE are usually costly, obtrusive and most are limited by laboratory conditions. Recent technological advancements in the sensor technology along with the great progress made in algorithms have made accelerometers a powerful technique often used to assess everyday physical activity. This paper discusses the use of support vector regression (SVR) to predict EE by using a single measurement unit, equipped with a triaxial accelerometer and a barometer, attached to the subject´s hip.

This paper describes the research made on current mobile health monitoring systems targeting the elderly and the development of an elderly-oriented solution, serving as a proof-of-concept of the research done. It provides a scientific contribution by specifying a system with characteristics never combined before, when applied to the health monitoring of older adults. Also, a prototype for that system was developed and evaluated with its end users – the elderly.

This paper deals with providing adapted media content and services for elderly and dependent persons living alone. In our approach, providing solutions and technologies for elderly requires to consider the simplification of architectures and the acceptance of the user. We propose to provide content and services using familiar TV sets and to consider medical advices and recommendations in using media and TV programs. As the user control is a key criterion in adopting context-aware systems, we consider the user actions and preferences. The proposed media selection scheme considers the evolution of the user preferences based on the recent user behavior patterns.

Influent voices from different areas like government and insurance companies already realized the savings that could be done with remote health monitoring and assistance systems. The TV is still the technology that older adults feel more comfortable with, and therefore we present , a new prototype that perfectly integrates with TV viewing experience and uses this almost ubiquitous mean to provide some features that they really feel the need in their daily lives: health agenda, medication intake and vital sign measurement scheduling and alerts, vital sign monitoring, videoconference with doctors and other features that may be also useful for doctors like support for medical questionnaires and health videos.

The proliferation of private, corporate and community Wi-Fi hotspots in city centers and residential areas opens up new opportunities for the collection of biomedical data produced by sensors carried by mobile non-hospitalized subjects.

New wireless wearable monitoring systems worn by patients and caregivers require a high degree of reliability and autonomy. We show that active textile antenna systems may serve as robust platforms to deploy such wireless links, in the meanwhile being comfortable and invisible to the wearer, thanks to recent developments in the design process combined with dedicated signal processing techniques. The key idea is to exploit the large amount of real estate available in patients’ and caregivers’ garments to deploy multiple textile antennas each with a size large enough to make them efficient radiators when deployed on the body. The antenna area is then reused by positioning active electronics directly underneath and energy harvesters directly on top of the antenna patch, ensuring the autonomy of the module. Combining different antenna signals by means of low-power multi-antenna processing techniques then ensures good signal quality at low transmit power in all situations.

We present a device-free localization method oriented to Ambient Assisted Living applications. The system exploits the received signal strength (RSS) measured by fixed wireless communications devices, whose position is known a priori, in order to localize a person in the transmission coverage area. The proposed localization system is passive, by not requiring the user to wear anything, and is able to trade complexity for accuracy by simply changing the number of deployed devices. The presentation is validated by an indoor experimental study.

Designing HCI in a medical context is not trivial. It needs to provide patients and medical experts with essential information for the tasks to be performed while ensuring the safety of operations. In this paper, we tackle this issue focused on the HCI requirements and expectations revealed by the use of mobile devices (Smartphone for patients/Tablet for specialists) on the assistance of cochlear or cardiac implanted patients. To illustrate the feasibility of our research work, we report several experiments and evaluations attempting to guarantee the safety of operations on adjusting cochlear implants and supporting the monitoring of patients with cardiac implants. This work is carried out as part of an academic and industrial research project.

Intrabody communication (IBC) uses the human body as a transmission medium for electrical signals, providing an efficient channel to interconnect devices in Body Sensor Networks. For IBC galvanic coupling, the signal path is accomplished through two pairs of electrodes deployed on the skin, which suggest the dependence of the attenuation signal on the subject’s electrophysiological skin properties. With the purpose of gaining an insight into the attenuation differences observed for diverse subjects, a simple transmission line-based model has been used for the identification of those personalized parameters that best emulate the attenuation behavior. Experimental results for two different subjects have been carried out using a harmonized measurement set-up. Model simulations have shown to match measurement data more accurately when individualized instead standard skin parameters were used, thus highlighting the need to deal with personalized models in IBC research.

The paper presents an analogue front-end and ADC integrated circuit for processing signals of sensors implanted into joint prosthesis. The circuit is designed to be operated with Wheatstone bridge sensors, such as strain gauges, pressure, Hall Effect, magneto-resistive sensors, etc. It performs sensor supply multiplexing, sensor signal amplification with chopper modulation, offset compensation and 14-bit analog to digital conversion in a single chip. It can operate simultaneously up to eight sensors at an overall bandwidth of 8 kHz, and can be directly interfaced to a remotely powered RFID system in order to constitute a complete multi-sensor, low-power, small size and externally powered micro-system. Integrated into a 180 nm CMOS process, it measures 5 mm, is supplied with 1.8 Volt and consumes 1.8 mW.

Power efficient communication in a Wireless Body Area Network (WBAN) is critical for successful system deployment. Stringent constraints of size and weight of sensors significantly limit available sensor power, particularly in the case of implantable sensors. This paper discusses and analyses methods that could be used to improve power efficiency of implantable WBAN systems, with focus on the Wake Up Radio (WUR), which allows power efficient listening of wireless channel. The paper presents analysis of existing hardware and design trade offs in WUR implementation.