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News

Join to Neural Data Processing Contest during MetroXRAINE conference!

The Neural Data Processing Contest wiil be held during the MetroXRAINE conference in Rome (National Research Council Headquarters) on Friday, Oct. 28 at 9 a.m. The contest has been though for both MSc and PhD students who want to test and develop their skills and competences in data analysis concerning emotional conditions and motor imagery. A cash prize of 500 euros from ab medica s.p.a. will be given to the participant who will be able to perform the best classification on EEG datasets acquired through the Helmate headset provided by ab medica spa.

Special fee of 30 euros for M.Sc. Student. Remote participation is allowed only for M.Sc. students from universities outside the Lazio Region.

On the MetroXRAINE conference website you can find: • the contest rules (https://lnkd.in/gBn__HCd) • the registration form (https://lnkd.in/gzcYNrkk) • the datasets to train your classifiers (https://lnkd.in/g6rszUip)

News

FuseNet PhD Event 2022 4-6 July Padova (Italy)

On 4^th-6^th July, the FuseNet PhD Event 2022 took place in Padua, Italy. 131 PhD students coming from 23 countries and 44 different institutes and universities, including the University of Tuscia in Viterbo, participated and animated the FuseNet PhD Event 2022. After two years, it finally took place in a live format again, in the amazing venues of University and Orto Botanico of Padua. The event was hosted by the University of Padua and Consorzio RFX and it was the place where European fusion PhD students meet and interact with affirmed international researchers in the field of Nuclear Fusion, aiming to strengthen and expand the fusion research network.
University of Tuscia was present at the event with 8 PhD students, who presented their research activities during poster sessions over the 3 days.
During three days, participants had the possibility to listen interesting talks of different important personalities in the fusion research as: Elena Righi (Head of Unit Euratom, European Commission), Piero Martin (professor at University of Padova), Elena de la Luna (researcher at LNF CIEMAT), Simone Peruzzo (Head of Technology and Engineering at Consorzio RFX), Gianluigi Serianni (researcher at Neutral Beam Test Facility), and Chiara Bustreo (project leader of the EUROfusion Socio Economic Studies). Three guided tours were organized to explore some important places of Padova: Palazzo Bo, Orto Botanico and Consorzio RFX. Furthermore, different oral sessions and poster sessions animated the days and permitted the students to know a lot about different topics related to the Nuclear Fusion world. To conclude social dinners entertained participants.
Different topics were exposed during the poster sessions from University of Tuscia. A brief presentation is reported.

A work concerning the conceptual design of the mirrors of the multi beam transmission line of the Electron Cyclotron Heating system of the Divertor Tokamak Test Facility (DTT) was presented. In particular different coupled thermal and structural finite element (FE) simulations were carried out to study some first proposals of mirror design, comparing different structures and materials.
A work concerning thermo-structural coupled analyses of the DTT vacuum vessel in multiple machine operating states was presented. The design was verified against the principle nuclear standards and design changes have been proposed according to the results of such verifications.
A work concerning the conceptual design of the vacuum system for DTT was presented, focusing on three main sub-systems: divertor, vacuum vessel and cryostat. In particular the systems operations were explained, and estimations of regeneration and evacuation times were carried out and a first layout shown.
A work concerning the Spherical Tokamak ST40, owned by Tokamak Energy Ltd, was presented. In particular the definition of the structural behaviour of the ST40 Inner Vacuum Chamber under the action of electromagnetic loads from plasma fast “upper vertical displacement event” scenario was investigated. The considered loads were obtained from the electromagnetic analysis of the device and interpolated on the structural model. Indeed, the study represents the final phase of the proposed procedure, and it verifies the compatibility for non-conventional low aspect ratio tokamaks.
A work concerning the structural assessment of tokamak components under thermal and electro-magnetic loads emerging during normal and off-normal operations (e.g., plasma disruptions) was presented. An approach aimed at 3D detailed evaluation of the electro-magnetic loads experienced by the tokamak structures both in normal and off-normal conditions was proposed, developed and successfully applied to DEMO, DTT and ST40.
A work concerning the description of the neutral model in the GBS simulation code was presented. The simulations are able to reproduce neutral-plasma interactions in the 3D turbulent fluid simulations made with GBS. They show the first simulations obtained with neutrals in a TCV-like scenario, a study of the density shoulder formation, along with the latest work made to simulate also the molecular neutral dynamics.

Finally, a work about the first wall sacrificial limiters inside the vacuum vessel that represents the last protection resource to prevent the reactor wall from excessive damage was presented. The integration of W-lattices in the architecture of such components can allow to meet their conflictual requirements: through a prompt vapour shielding formation, these can ensure effective thermal decoupling between plasma and heat sink during disruptions and provide effective exhaust of the nominal thermal load during stationary operation.

FuseNet PhD event Article
FuseNet PhD Event website

News

Microwave Transducers for Gas Sensing: A Challenging and Promising…

The research of new typologies of gas sensors with improved detection performance has resulted in a wide adoption of gas sensors in different fields. The technology development has led to the introduction of low-cost, compact gas sensors with improved performance in detection process. The major purposes of gas detection are environmental monitoring, human health monitoring and industrial plant safety. Today, environmental monitoring is a subject of utmost importance. A substantial amount of airborne pollution, which has a negative influence on both public health and the climate, is a hallmark of the economic prosperity of contemporary society. The need for the development of gas sensors used in the detection of harmful chemicals such nitrogen oxides, sulfur dioxide, carbon monoxide, ozone, and benzene has become more pressing as a result of today’s pervasive and persistent atmospheric pollution. Additionally, concerns with public health are brought on by atmospheric pollution in metropolitan areas, rural areas, and even inside houses.

Moreover, gas sensors are employed in medical applications. As an example, oxygen sensors are used in the oxygen therapy, while ammonia sensors have been employed to identify chronic renal illness. Finally, gas sensors are frequently used in industrial environment, including hazardous emissions monitoring, chemical detection in the production of plastics, and in the chain of food production and storing.

Commercial gas sensors typically use conductometric transducers because they have a long lifespan, great resolution (at the ppm level), and are relatively inexpensive. Due to the alluring benefits of this technology, interest in research on gas detection using microwave transducers has increased in the last years. Since microwave gas sensors may operate at room temperature, less power is needed to manage them. Moreover, they are characterized by a fast response time.

In such a context, the University of Messina has contributed to researching novel microwave transducers for sensing applications. In particular, the research group held by Prof. Donato (University of Messina, Res4Net member) has proposed several configurations of microwave gas sensors.

A brief review of the latest advances in the development of microwave transducers for gas sensing can be found here

News

Localization and characterization of cable faults with tdr and…

Methodology: The situation considered is represented in Fig. 1. The cable has total length and contains localized faults, simulated by means of capacitors connected in parallel by means of T-junctions. The capacitors are placed at a distance from the beginning of the cable and have capacitance . The stimulus signal is generated by an Agilent 33250A AWG, while the TDR signals are acquired using a LeCroy Waverunner-2 LT262 oscilloscope. A Gaussian pulse is used as the stimulus signal.

The neural network employed was inspired by single-shot CNNs (YOLOs) for object detection. These neural networks consist of a sequence of convolutional and pooling layers. Since in the present case signals are processed in the time domain, 1D convolutional layers are used, rather than 2D ones, as the basic component of the model. The input of the first layer is the measured TDR signal, the output of the last layer is an matrix ( is number of cells into which the length of the line is divided), which identifies position, class, impedance and probability of the fault.

The training set of the neural network is obtained by generating simulated reflectograms under various fault conditions. The simulator uses the primary RCGL parameters of the line, which were identified using the stepped-frequency waveform reflectometry (SFWR) developed in [3]. This technique can be used easily for long cables and using low-cost, portable instrumentation. The identification obtained is quite accurate, as shown in Fig. 2.

Results: Tables I and II summarize some of the results obtained. In particular, Table I reports some results obtained on cables with four capacitive faults and shows the remarkable accuracy with which they are localized. The quantification may appear less accurate; however, it must be said that the capacities reported are simply nominal capacities of the capacitors used to simulate the fault. These capacities have quite high tolerances per se and are not related to the frequency range of the TDR signal used in the test. Table II reports statistics on the overall measurement errors in all the experiments conducted (six with a single failure, six with two failures, two with three failures, two with four failures), in terms of RMS error and mean absolute percentage error (MAPE).

Conclusions: The experiments showed that the proposed method is remarkably accurate, as well as being very general. It can be applied to the localization and characterization not only of faults in cables, but also of points of discontinuity in distributed sensitive elements.

References:

[1] Scarpetta, M.; Spadavecchia, M.; Adamo, F.; Ragolia, M.A.; Giaquinto, N. Detection and Characterization of Multiple Discontinuities in Cables with Time-Domain Reflectometry and Convolutional Neural Networks. Sensors 2021, 21, 8032. doi: 10.3390/s21238032 .

[2] M. Scarpetta, M. Spadavecchia, G. Andria, M. A. Ragolia and N. Giaquinto, “Analysis of TDR Signals with Convolutional Neural Networks,” 2021 IEEE International Instrumentation and Measurement Technology Conference (I2MTC), 2021, pp. 1-6, doi: 10.1109/I2MTC50364.2021.9460009.

[3] N. Giaquinto, M. Scarpetta and M. Spadavecchia, “Algorithms for Locating and Characterizing Cable Faults via Stepped-Frequency Waveform Reflectometry,” in IEEE Transactions on Instrumentation and Measurement, vol. 69, no. 9, pp. 7271-7280, Sept. 2020, doi: 10.1109/TIM.2020.2974110..

Table I. Estimation results for real cables with four capacitive faults.

	Experiment 1		Experiment 2
	Nominal	Estimated	Nominal	Estimated
Length of the cable (m)	143	142.96	143	142.96
Position of fault 1 (m)	50	49.87	50	49.88
Position of fault 2 (m)	65	65.12	65	65.03
Position of fault 3 (m)	115	114.93	115	114.95
Position of fault 4 (m)	131	131.40	131	131.32
Capacity of fault 1 (pF)	107	117	107	115
Capacity of fault 2 (pF)	217	214	152	165
Capacity of fault 3 (pF)	404	436	309	323
Capacity of fault 4 (pF)	450	441	450	439

Table II. Estimation errors obtained for experimental signals.

Cable length error			Fault position error				Fault capacity error
RMSE (m)	MAPE		RMSE (m)		MAPE		RMSE (pF)		MAPE
0.12		0.10%		0.13		0.22%		14		4.3%

News

The IEEE International Conference on Computational Intelligence and Virtual…

The IEEE International Conference on Computational Intelligence and
Virtual Environments for Measurement Systems and Applications (CIVEMSA June-2022) was held in Chemnitz from 15 to 17 June 2022.
It was dedicated to all aspects of computational intelligence, virtual environments, and human-computer interaction technologies for measurement systems and related applications.
Prof. Pasquale Arpaia of the Res4Net held the opening Keynote focused
on active, reactive, and passive Brain Computer Interface for 4.0
applications in the medical and industrial fields.

A brief history of CIVEMSA

In 1996, the IEEE Instrumentation and Measurement Society organized the IEEE Workshop on Emerging Technologies in Instrumentation and Measurement to explore the theoretical insights and the practical use of innovative technologies for the area of measurement systems and related applications. Two main areas were considered: computational intelligence and virtual environments.

The workshop evolved, with different names, in each of the subsequent years by focusing on various aspects of these areas and becoming a symposium.

In 2003 the organizers realized that the topics and the communities interested in this workshop were diverging and therefore started two conferences, each focusing on one of the two areas mentioned above: the IEEE International Conference on Computational Intelligence for Measurement Systems and Applications (IEEE CIMSA) and the IEEE International Conference on Virtual Environments, Human-Computer Interfaces, and Measurement Systems (IEEE VECIMS). IEEE CIMSA was sponsored by the IEEE Computational Intelligence Society and the IEEE Instrumentation and Measurement Society, while IEEE VECIMS was sponsored only by the IEEE Instrumentation and Measurement Society. The two meetings were held in parallel in the same location, to exploit synergies in local arrangement expenses and efforts, even though the communities started clearly to separating one from the other. These conferences constituted two successful series which reached the tenth edition in 2012.

In the past few years, however, the organizers noticed a convergence of the two technological areas of these conferences. For this reason, the Steering Committees of the two conferences unanimously voted to terminate the two series and merge the meetings in a new conference series to maximize the benefits for the communities: IEEE International Conference on Computational Intelligence and Virtual Environments for Measurement Systems and Applications (IEEE CIVEMSA).

Past Conference Listings & Websites

IEEE CIVEMSA 2021

Virtual
2021 IEEE International Conference on Computational Intelligence and Virtual Environments for Measurement Systems and Applications

IEEE CIVEMSA 2020

Virtual
2020 IEEE International Conference on Computational Intelligence and Virtual Environments for Measurement Systems and Applications

IEEE CIVEMSA 2019

Tianjin, China
2019 IEEE International Conference on Computational Intelligence and Virtual Environments for Measurement Systems and Applications

IEEE CIVEMSA 2018

Ottawa, Canada
2018 IEEE International Conference on Computational Intelligence and Virtual Environments for Measurement Systems and Applications

IEEE CIVEMSA 2017

Annecy, France
2017 IEEE International Conference on Computational Intelligence and Virtual Environments for Measurement Systems and Applications

IEEE CIVEMSA 2016

Budapest, Hungary
2016 IEEE International Conference on Computational Intelligence and Virtual Environments for Measurement Systems and Applications

IEEE CIVEMSA 2015

Shenzhen, China
2015 IEEE International Conference on Computational Intelligence and Virtual Environments for Measurement Systems and Applications

IEEE CIVEMSA 2014

Ottawa, Canada
2014 IEEE International Conference on Computational Intelligence and Virtual Environments for Measurement Systems and Applications

IEEE CIVEMSA 2013

Milan, Italy
2013 IEEE International Conference on Computational Intelligence and Virtual Environments for Measurement Systems and Applications

IEEE CIMSA 2012

Tiajin, China
2012 IEEE International Conference on Computational Intelligence for Measurement Systems and Applications

IEEE VECIMS 2012

Tiajin, China
2012 IEEE International Conference on Virtual Environments, Human-Computer Interfaces and Measurement Systems

IEEE CIMSA 2011

Ottawa, Canada
2011 IEEE International Conference on Computational Intelligence for Measurement Systems and Applications

IEEE VECIMS 2011

Ottawa, Canada
2011 IEEE International Conference on Virtual Environments, Human-Computer Interfaces and Measurement Systems

IEEE CIMSA 2010

Taranto, Italy
2010 IEEE International Conference on Computational Intelligence for Measurement Systems and Applications

IEEE VECIMS 2010

Taranto, Italy
2010 IEEE International Conference on Virtual Environments, Human-Computer Interfaces and Measurement Systems

IEEE CIMSA 2009

Hong Kong, China
2009 IEEE International Conference on Computational Intelligence for Measurement Systems and Applications

IEEE VECIMS 2009

Hong Kong, China
2009 IEEE International Conference on Virtual Environments, Human-Computer Interfaces and Measurement Systems

IEEE CIMSA 2008

Istanbul, Turkey
2008 IEEE International Conference on Computational Intelligence for Measurement Systems and Applications

IEEE VECIMS 2008

Istanbul, Turkey
2008 IEEE International Conference on Virtual Environments, Human-Computer Interfaces and Measurement Systems

IEEE CIMSA 2007

Ostuni, Italy
2007 IEEE International Conference on Computational Intelligence for Measurement Systems and Applications

IEEE VECIMS 2007

Ostuni, Italy
2007 IEEE International Conference on Virtual Environments, Human-Computer Interfaces and Measurement Systems

IEEE CIMSA 2006

La Coruna, Spain
2006 IEEE International Conference on Computational Intelligence for Measurement Systems and Applications

IEEE VECIMS 2006

La Coruna, Spain
2006 IEEE International Conference on Virtual Environments, Human-Computer Interfaces and Measurement Systems

IEEE CIMSA 2005

Giardini Naxos – Taormina, Italy
2005 IEEE International Conference on Computational Intelligence for Measurement Systems and Applications

IEEE VECIMS 2005

Giardini Naxos – Taormina, Italy
2005 IEEE International Conference on Virtual Environments, Human-Computer Interfaces and Measurement Systems

IEEE CIMSA 2004

Boston, MA, USA
2004 IEEE International Conference on Computational Intelligence for Measurement Systems and Applications

IEEE VECIMS 2004

Boston, MA, USA
2004 IEEE International Conference on Virtual Environments, Human-Computer Interfaces and Measurement Systems

IEEE CIMSA 2003

Lugano, Switzerland
2003 IEEE International Conference on Computational Intelligence for Measurement Systems and Applications

IEEE VECIMS 2003

Lugano, Switzerland
2003 IEEE International Conference on Virtual Environments, Human-Computer Interfaces and Measurement Systems

IEEE VIMS 2002

Girdwood, AK, USA
2002 IEEE International Symposium on Virtual and Intelligent Measurement Systems

IEEE VIMS 2001

Budapest, Hungary
2001 IEEE International Workshop on Virtual and Intelligent Measurement Systems

IEEE VIMS 2000

Annapolis, MD, USA
2000 IEEE International Workshop on Virtual and Intelligent Measurement Systems

IEEE VIMS 1999

Venice, Italy
1999 IEEE International Workshop on Virtual and Intelligent Measurement Systems

IEEE ETIMVIS 1998

St. Paul, MN, USA
IEEE International Workshop on Emergent Technologies, Intelligent Measurement and Virtual System for Instrumentation and Measurement

IEEE ETVSIM 1997

Niagara Falls, Canada
IEEE International Workshop on Emergent Technologies and Virtual System for Instrumentation and Measurement

IEEE ETIM 1996

Como, Italy
IEEE International Workshop on Emergent Technologies for Instrumentation and Measurement

View details of conference

News

Deep Learning-Based Computer Vision for Real-Time Intravenous Drip Infusion…

Two basic tasks in the perioperative period are i) surgery and ii) patient monitoring and care. The outcome of diagnosis and surgical interventions can be improved by means of electromagnetic tracking systems (EMTSs) [1], widely used in surgical navigation. They employ very small EM sensors, which measure the magnetic field produced by a field generator, thus accurately estimating the pose of the instrument in the operative scenario. Moreover, in the pre- and postoperative phase, monitoring the flow rate of the fluid being administered to patients is very important for their safety. Hence, our proposed system [2] uses a camera to film the intravenous (IV) drip infusion kit and a deep learning-based algorithm to detect and count drops. The usage of a camera as a sensing element is safe in medical environments and can be easily integrated into current health facilities.

1. Example of Application field: Health, Tracking
2. Example of Activity: Monitoring, Diagnosis, Surgery

News

Using MAXFEA code in combination with ANSYS APDL for…

A new scientific paper has been published by the UNITUS Nuclear Fusion Research team, concerning the development of a new multiphysics and multicode approach aimed at 3D detailed evaluation of the electro-magnetic loads experienced by the tokamak structures both in normal and off-normal conditions, e.g. plasma disruptions [2].

Plasma disruptions are one of the major concerns in the design phase of fusion devices. The very high eddy and halo currents, induced in the passive structures, crossing the electromagnetic field generate huge loads. According to [3], plasma disruptions are usually classified depending on the position of the plasma column at the Thermal Quench (TQ), as Major Disruptions (MDs) and Vertical Displacement Events (VDEs). A Vertical Displacement Event (VDE) begins with a loss of position control that develops before any appreciable cooling of the plasma core. The occurrence of undesired plasma perturbations such as Edge Localized Modes (ELMs), unforeseen H-L and L-H transitions, minor disruptions (mDs), etc., that are strongly connected to variations of plasma internal parameters and, consequently, to plasma displacements, are among the possible causes of such instabilities [4]. During a VDE, in an initial phase, the plasma moves vertically away from its equilibrium position and starts to induce current in the passive structure mainly by its movement. In this phase, the plasma moves towards the wall, reducing progressively its area, typically with a little change in the total plasma current, since the plasma thermal energy is still present. Then, when the plasma starts to significatively interact with the structures or when plasma reaches a critical value of the safety factor, conditions for a rapid growth of MHD activity inevitably arise and the TQ occurs. As a consequence of the TQ, the ensuing increase in plasma resistivity produces the Current Quench (CQ) phase.

During the plasma evolution, especially during the TQ and CQ, toroidal and poloidal eddy currents are induced in the metallic components, respectively due to the dynamic effect of plasma Poloidal Field Variation (PFV) and Toroidal Field Variation (TFV). The plasma time evolution and the effects of such events on the passive structures can estimated through 2D axisymmetric codes, such as MAXFEA. However, the presence of 3D structures (e.g. ports, divertor, etc.) generates non-trivial currents paths and distribution of EM loads. In order to estimate the 3D effects, MAXFEA has been used in combination with ANSYS, allowing to estimate both PFV and TFV consequences on the 3D model. Considering the DEMO PMI configuration and a fast upper Vertical Displacement Event (VDE), the procedure was successfully benchmarked, comparing the MAXFEA and APDL results, in a case where the 3D Vacuum Vessel (VV) was considered axisymmetric. The methodology has been then exploited and applied to estimate the EM load distribution on the real DEMO VV.

[1] Maviglia et al., “Integrated design strategy for EU-DEMO first wall protection from plasma transients,” Fusion Eng. Des., vol. 177, no. February, p. 113067, Apr. 2022.

[2] Lombroni et al., “Using MAXFEA code in combination with ANSYS APDL for the simulation of
plasma disruption events on EU DEMO”, Fusion Eng. Des., vol. 170, September 2021 112697, https://doi.org/10.1016/j.fusengdes.2021.112697

[3] Hender et al., “Chapter 3: MHD stability, operational limits and disruptions,” Nucl. Fusion, vol. 47, no. 6, pp. S128–S202, Jun. 2007.

[4] Sias et al., “Inter-machine plasma perturbation studies in EU-DEMO relevant scenarios: lessons learnt for EM forces prediction during VDEs,” Nucl. Fusion, Feb. 2022.

News

Res4Net presents TC-06 – Emerging Technologies in Measurements

In recent years, different areas have been explored, technical meetings have been organized (including special sessions in I2MTC, our Society’s main conference and workshops) to broaden analysis and discussion, and related communities have been aggregated in our Society. The committee also organized special sessions at other IEEE conferences to draw attention to specific areas of incubation and promote instrumentation and measurement principles, methods and technologies to other communities. Finally, the committee organized special issues in the IEEE Transactions on Instrumentation and Measurement, the I&M journal, and other emerging area journals. These efforts have led to the creation of some technical committees in our company, such as intelligent measurement systems and fault tolerant measurement systems. In addition, the TC-6 also inspired the creation of other technical groups and committees.

The TC-6 was recently launched with a focus on autonomous vehicle measurement and quantum computing technologies. Autonomous vehicles (such as those that fly or are underwater) have become a popular and cost-effective tool for many sensing and measurement applications (such as infrastructure inspection and testing, environmental monitoring and mariculture or agriculture), combining time and space coverage and accessibility unattainable with other technologies. A new generation of rovers are engaged in space missions. There is a demand for the development of new and advanced instruments, as well as for their calibration and testing. Astronomical Observation Instruments That Measure the Earth ‘

For quantum technologies, TC-6 began studying to determine the main technical areas where experience and expertise in our measurement community could be useful to more efficiently support the development and implementation of quantum systems. Recently, there have been breakthroughs in the accurate measurement of atomic qubit states, which is a key step in the development of quantum computers.

The objectives of this Committee are:

Stimulate the interest of researchers and professionals in emerging technologies in their application in the field of instrumentation, measurement and testing;
Respond to the growing demand for emerging technologies in terms of performance and functionality;
To disseminate the use and knowledge of emerging technologies in the I&M fields to the academic and scientific communities;
Provide forums such as workshops and conferences where such new and emerging technologies can be discussed;
Promote the use of these technologies in real applications;
Maintain contact with other groups, companies and standardization activities operating in the same fields.

News

UAVs for Agriculture 4.0 Applications

With a mean production of 450–550

\times 10^{6}

kg/year of olive oil, olive tree cultivation is undoubtedly one of the main sources of agricultural revenue for Italy. In particular, the Apulia region in the south, with over 360 kha (kilohectares) covered with 21 different olive cultivars with a prevalence of Ogliarola and Coratina cultivars, is the region with the highest percentage of production (>35% of the total yearly Italian production) [1]. In the past decade, this production has been greatly impacted by many threats, primarily Xylella fastidiosa (Xf), a pathogen that has been known around the world for decades, but which since 2013 has put the survival of Apulian olive cultivation at great risk. It is a bacterium that can attack olive trees, vines, oleander, and some species of citrus fruits, causing them to rapidly dry out. This phenomenon, when observed on the olive trees, is known as olive quick decline syndrome (OQDS) [2,3,4,5,6,7,8,9,10,11].

Xf is endemic to the American continent and, until recently, it did not exist in Europe [12]; indeed, its arrival in Europe was tracked back to the import of some infected ornamental plants from Costa Rica (Central America) to Gallipoli (province of Lecce in southern Italy) in 2013 [13]. From there, the bacterium spread to the northwest provinces of Brindisi and Taranto, and some infected trees have also been recently reported in the province of Bari (northeast). A large number of publications about the impact of Xf in Puglia are available; a small selection is included in the references [14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31].

The main problems concerning the detection of this disease in olive trees are the possible lack of symptoms over an incubation period ranging from 6 to 18 months from infection and the nonuniform distribution of the bacterium on the infected plants, making it somewhat difficult to identify until it is too late.

Characterization of infection spread may potentially be achieved as was done previously for citrus using geostatistical analysis and kriging estimation, which might also be combined with Kalman filter prediction; however, the availability of data from extended monitoring is fundamental [32,33].

To date, the most accurate method to detect the presence of the Xf bacterium is by means of laboratory genetic analyses using the PCR technique (polymerase chain reaction [34,35]), a sophisticated and complex technique used to reproduce small segments of DNA many times in order to be able to process them in successive tests. The PCR technique is more sensitive than serological analyses of the ELISA type (enzyme-linked immunosorbent assay [36,37]), which are sensitive to antibodies or antigens of a given pathogen. Due to their inherent lower sensitivity, ELISA-type tests can produce a greater number of false negatives. However, both these techniques require medium to long waiting times (some days) to produce results and are applicable only in a laboratory using high-cost analytical instruments, so they are not applicable in real time in the field. Indeed, they require intensive in situ inspection though interesting methods useful to estimate water content and thermal characterization have been proposed [38,39,40,41]. Recently introduced alternative techniques involve proximity or remote sensing, i.e., the use of electromagnetic radiation and its interaction with objects and living beings. The advancement of satellite and aerial detection techniques, telecommunications systems and optical sensors has led to the application of these analysis techniques to images acquired by satellites (remote sensing by satellite), small manned planes or helicopters, or aerial platforms with a remote pilot (unmanned aerial vehicles; UAVs), commonly called “drones” in a wide range of fields [41,42,43,44,45]. UAV platforms can be further distinguished as fixed-wing types, which allow monitoring of large areas from medium–high altitudes, and rotary-wing types, which allow observation of less extensive areas from medium–low altitudes. In recent years, the application of UAVs in precision agriculture as well as in many other fields is becoming more and more common, requiring test systems able to guarantee and certify both electrical and mechanical performance aspects of their propulsion subsystems [46,47,48].

Typically, the radiation reflected by vegetation is concentrated in the visible (VIS), near-infrared (NIR), and medium infrared (SWIR; short-wave infrared) spectral regions, while the emitted radiation is concentrated in the thermal infrared (TIR) spectral region.

Spectral analysis finds frequent and extensive use in many areas of the physical sciences; this technique is one of the statistical methods used to characterize and analyze sequenced data in one-, two-, and three-dimensional space. In this area, many studies have been devoted to reducing bias and variance of the estimates [49,50].

The spectral signature of vegetation, which is the relative intensity of the re-radiated radiation as a function of the wavelength of the incident light, contains a range of information. Indeed, the shape of this curve

depends on the photosynthetic activity in the VIS region;
depends on the structure of plants’ leaves and foliage (size, number of leaf layers, etc.) in the NIR region;
is strongly influenced by the water content in the SWIR region.

The use of terrestrial or aerial drones, both manned and unmanned, equipped with multi- or hyperspectral image cameras to study the health status of plantations of various kinds is not a novelty in precision agriculture or for forestry monitoring [51,52,53,54,55]. There are also pioneering applications of drones for the detection of Xf-infected plants [56,57,58,59].

Xf represents such a serious threat to the future survival of the olive orchards in Italy that the Italian Ministry of Economic Development (MiSE) recently committed €3.5 million to funding another important research project named REDoX (Remote Early Detection of Xylella), which is focused on the detection and monitoring of Xf using multispectral, hyperspectral, and thermal imagery obtained by aircrafts, UAVs, and satellites. The REDoX project is being coordinated by the Apulian Aerospace Technological District (DTA) [60].

In this paper, it is shown that multispectral imagery shot using a midsized rotary-wing UAV can be successfully used to evaluate the health of olive trees in nearly real time with respect to olive quick decline syndrome due to Xf. For this purpose, a tree segmentation algorithm was developed and linear discriminant analysis (LDA) was applied to multispectral stacks. In Section 2, after a brief introduction to remote sensing in agriculture, the equipment used in this research and standard vegetation indexes are described. The proposed algorithm is also presented: image preprocessing is described Section 2.1; 3D reconstruction of the scene is described in Section 2.2; tree segmentation is detailed in Section 2.3; and health status classification is described in Section 2.4. Experimental results and performance evaluation are provided in Section 3, followed by discussion in Section 4 and conclusions in Section 5.

News

Sensors and sensor-based measurement systems: design, development and challenges

In the last decade, the sensors market has witnessed an abrupt rising adoption rate in the wake of a variety of factors, including widespread IoT applications, growing wireless network demand, and rising demand for high accuracy sensors and more efficient and reliable measurement systems. Sensors are used for a wide range of applications such as environmental monitoring, agriculture, healthcare, and human-machine interaction. With the increasing advances of sensor technologies in a wide range of applications, sensing devices have become more and more pervasive and capable. For instance, the number of sensors included in the latest generation of smartphones is huge: from the touchscreen and fingerprint sensors to the heart rate sensor passing through the Global Positioning System (GPS) sensor. Their combination enables users to interact with the device, support their everyday activities, and monitor their state of health. Likewise, wearables equipped with sensors (e.g., smartwatches and smart bands) have also become an increasingly popular option for monitoring health and fitness.

Additionally, several factors have also resulted in the surging demand for sensors, such as increasing Internet connectivity worldwide, growing industrial automation, and growing requirements for improved efficiency in industries. The global sensing market is thus expected to experience strong growth in the next few years. The market is also expected to gain prominence over the forthcoming years owing to the rise in the integration of IIoT and 5G networks.

In this context, the research of novel sensors and sensor-based measurement systems represents one of the most important challenges for the development of new and advanced applications.

This is the main topic of the Sensors Journal (MDPI) Special Issue (SI) entitled “Sensors and Sensor-Based Measurement Systems: Design, Development and Challenges” and edited by Prof. Nicola Donato from the University of Messina (Res4Net member) in collaboration with Dr. Luca Lombardo (Politecnico di Torino) and Dr. Giovanni Gugliandolo (University of Messina).

The scope of this SI is to publish high-quality research papers as well as review articles including, but not limited to, design, development, characterization, and employment of sensors and sensor-based measurement systems. New application scenarios, as well as sensor technology and sensor fusion and measurement issues, are also topics of interest.

The SI is open and will accept paper proposals up to 20 January 2023.

For more information visit the official SI page