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The Low Power Wide Area Networks (LPWANs) have been proposed as viable wireless connection method for the implementation of the Internet of Things (IoT), thanks to their wide coverage, low complexity and low power consumption. In this scenario, LoRaWAN emerged as a de-facto leading technology, because of its openness and the current availability of many devices (like sensors and gateways). Several implementations of the LoRaWAN specifications have appeared in the market, each one showing support for different hardware, different software architectures, and different operating systems. Thus, the need of test procedures for comparing them is evident. In this paper, a test methodology for the experimental assessment of architectural delays of LoRaWAN implementations is presented. The new approach is composed of: a mapping phase, needed for highlighting the LoRaWAN blocks inside the implementation under test; followed by a measurement phase, in which the relevant timestamps are taken along the information path from LoRaWAN node to LoRaWAN customer application. The use and the effectiveness of the proposed methodology are shown by means of use cases that involve different LoRaWAN implementations and several hardware platforms. The experiments described in the paper are not intended to evaluate particular implementations but they are aimed to assess the suitability of the proposed methodology. The results demonstrate that the proposed approach can be used to compare the performance of entire LoRaWAN systems, helping the owner of the infrastructure and the user in making choices and optimizations.

Background and objectives: We studied a large series of ductal carcinoma in situ with microinvasion (MIDC) an infrequent disease whose diagnosis and management are not well defined. Methods: 17,431 cases of breast carcinoma were treated between 2011 and 2016 by ten Italian Breast Units. Our analysis included diagnostic and clinic-pathological characteristics, surgical management, and the use of adjuvant therapies. Results: 15,091 cases (86.6%) were infiltrating carcinomas (IC), 2107 (12.1%) ductal carcinoma in situ (DCIS), and 233 (1.3%) MIDC. Age at diagnosis did not differ between DCIS and MIDC. MIDC were usually larger and expressed more frequently biologically aggressive features (higher Ki67 values, hormone receptor negativity and HER2/neu over-expression) (p < 0.01). Axillary lymph nodes were involved in 25 MIDC cases (12%), but >3 lymph nodes were involved in two cases only (1%). At multivariable analysis, only lymphovascular invasion (LVI) was associated with lymph node status (p < 0.01). Hormone therapy was prescribed in 388/1462 DCIS cases (26.5%), in 84/200 MIDC cases (42%), and in 11,086/14,188 IC cases (84.7%) (p < 0.01). Chemotherapy was administered in 28/190 MIDC cases (14.7%), and in 4080/11,548 IC cases (35.3%) (p < 0.001). Conclusions: This is one of the largest studies of MIDC reported in the literature. Approximately 10% of DCIS harbor one or more foci of MIDC, and the latter often expresses aggressive biological features. LVI is a predictor of axillary node involvement, but this is infrequent and usually limited. Conservative surgery is performed less often than in DCIS, and adjuvant chemotherapy is less frequently utilized compared to IC.

Distributed monitoring and control systems are mandatory for the efficient management of the distribution grid, due to the growing presence of renewable energy sources. Time synchronization among devices deployed in distribution grid plays a key role, since a common time reference is essential to correlate power quality and high sampling frequency measure, and generally coordinate any distributed actions. The design and the deployment of a time synchronization system over an existing heterogeneous network is investigated in the paper. The Network Time Protocol (NTP) has been chosen due to its backward compatibility, the good security level, and the intrinsically robust hierarchy. Several NTP synchronization architectures have been proposed and then applied to a real (operating) distribution grid, both at Medium Voltage (MV) and Low Voltage (LV). The experimental validation was carried out during several weeks on the live system. The results in the MV grid highlight the trade-off existing between synchronization accuracy and availability: the synchronization accuracy over MV Broadband Power Line (BPL) links decreases from 20ms to 50ms when a more reliable architecture, from the point of view of time synchronization, is used. On the other hand, experimental results show as end-nodes connected on LV grid by means of BPL have a mean offset typically below 50ms, and a synchronization accuracy on the order of 150ms. These results are due to the limitation of the synchronization protocol deployed in the LV end-nodes and to scalability issues of power line communication networks when the number of nodes increases.

The installation of Power Quality (PQ) meters is becoming mandatory in many countries to face the problems introduced by the increasing number of renewable energy sources with intermittent generation. Unfortunately, the current situation is unbalanced: PQ meters are installed on High Voltage (HV) transmission lines and sometimes on Medium Voltage (MV) lines, while the highest number of renewable generators is connected to Low Voltage (LV) grid. In this paper, a novel measurement system for the analysis of voltage dips is proposed. If compared with existing similar systems, the proposed distributed measuring system has the following new characteristics: it is composed of a network of PQ meters on HV, MV and also on LV lines; it uses a heterogeneous communication infrastructure to interconnect meters; it has a cost-effective network-based time synchronization instead of costly GPS solutions; it implements a distributed algorithm to determine the origin of PQ problems. This novel approach overcomes scalability issue, which currently is limiting a larger penetration of PQ systems. The proposed distributed system for monitoring of voltage dips has been deployed in a real distribution grid in Italy. The paper reports analyses on data collected during an entire year. Voltage dips have been correlated and analyzed thanks to the time synchronization of the system.

A possible solution to reduce healthcare costs in a world that is aging is the adoption of telehealth technologies. Several solutions appeared, in the past suggesting the use of smart devices (mobile phones or tablets) for supporting telehealth. Unfortunately, elderly people may have difficulties in the use of such devices even if user interfaces are becoming friendly and intuitive. This work introduces the concept of “Smartstone”, that is the use of a (low-cost) smartphone as a simple, effective, and portable gateway/edge server for mobile healthcare towards cloud and Internet of Things (IoT) applications. The Smartstone is designed in order to minimize the user interaction, thanks to its autonomous behavior. The adoption of smart devices as a building block ensures state-of-the-art connectivity and relatively high computational power, complemented by an ensemble of additional onboard sensors. In particular, results about the management of a new photoplethysmographic /bio-impedance monitor and a smart pill dispenser are presented in this work.

In the last few years, the availability of powerful personal computing devices, like smartphones, has opened new scenarios to the so called “Body Area Network” (BAN), i.e., sensor networks specifically designed to monitor physical conditions of the user. The traditional methods adopted to monitor physical parameters, like heart beat rate or exertion level, are not suitable for real-time measurements. However, a continuous monitoring of such kind of parameters would allow the athletes to constantly control their physical conditions, furnishing useful information to prevent overstrain and to improve their performance. In this work, a simple, portable and low-cost system for non-invasive and real-time measurement of physical parameters is proposed and experimentally characterized. It is composed of three units: the sensor apparatus, electronic interface circuit, and the data transmission unit. Two different sensors are combined in a unique structure to be placed in a clip-like fashion on the earlobe or other body part of a person. A photoplethysmographic sensor is used to optically measure the changes of blood volume in the arteries, thus to acquire information about heart beat, blood pressure, and arrhythmias. The second sensor is composed of two electrodes, hence an impedance measurement of the tissue is carried out. The impedance estimation can be used to monitor the dielectric properties of biological tissues and fluids, like blood flow. A commercial battery-operated Bluetooth earphone is used both to transmit sensor data and to provide the power supply for the sensors and the first conditioning electronics. Data transmission is operated by the standard Bluetooth Hands-Free profile; therefore, sensor data can be easily acquired, elaborated and visualized by a broad range of commercial devices. In fact, Hands-Free is the only Bluetooth data communication profile supported by any smartphone, from the low-cost ones to the high-end devices. The experimental characterization of the prototype, performed by using a specifically designed application for Android smartphone systems, has demonstrated the validity of the proposed approach.

In the last years, the availability of performing personal computing devices, like smartphones, opens new scenarios to the so called Body Area Network, i.e., sensor networks used to monitor physical conditions of the user. Generally speaking, the sensors adopted to monitor physical parameters, like heartbeat or exertion level, are not suitable for run–time measurements. However, the physical performance of athletes may be improved by a continuous monitoring of the body conditions. In this work, a simple, portable and low-cost system for non-invasive measurement of physical parameters is proposed and experimentally characterized. It is based on two different sensors combined in a unique structure to be applied in a clip-like fashion to the earlobe or analogue body part of a person. A photoplethysmographic sensor is used to optically measure the change in volume of blood in the arteries, thus to acquire information about heart beating, blood pressure, and arrhythmias. The second sensor is composed of two electrodes, thus an impedance measurement of the tissue is conducted. The impedance estimation can be used to monitor application-specific parameters, such as blood pH. The structure is compact in size and low-power, making it suitable for portable and battery-operated systems. The experimental characterization of the prototype demonstrates the feasibility of the proposed approach.

The rare earth-iron systems, RFe2, have enormous magnetic anisotropy and magnetostriction. They are ferrimagnets, with canting at both sites in the amorphous phase. In amorphous materials the remanence is enhanced by exchange pulling between spins, unlike in large grain polycrystals, and we calculate at lowanisotropy a cutoff in the coercivity, and at large anisotropy/exchange, a proportionality of coercivity to anisotropy. Taking account of exchange, we can fit the composition dependence of Tc and the magnetization, and taking account of anisotropy, we can describe the coercive force and initial magnetization. Next, the elastic properties: Single crystal Terfenol has a 50% reduction in c44 with field, the largest known. In polycrystal and amorphous samples the moment breaks the rotation symmetry. There are then two normal shear wave modes with strain polarizations parallel and perpendicular to the magnetic field. This splitting comes from magnetoelastic coupling and is new effect.

The structures of amorphous DyFe2, TbFe2 and HoFe2 have been investigated using the extended X-ray absorption fine structure (EXAFS). The rare earth environment changes dramatically in going from the crystalline to amorphous form while the iron environment remains approximately the same.