Sensor-based ICT Systems for Smart Societies

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Infrastrutture digitali nei componenti di involucro per la gestione degli edifici

La rivoluzione digitale portata dall’IoT sta rapidamente mutando il modo in cui progettiamo, viviamo e gestiamo gli ambienti urbani. In questo contesto la componente immateriale legata al progetto architettonico assume una valenza nuova nell’uso consapevole delle risorse, nella tracciabilità dei processi e nella gestione sostenibile degli edifici. L’articolo presenta i primi risultati di una ricerca mirata allo sviluppo di tecnologie low-cost integrabili nei componenti edilizi di involucro. Si riporta l’esperienza condotta sull’utilizzo di sensori per il monitoraggio della qualità dell’aria

Understanding the Impact of Cutting in Quantum Circuits Reliability to Transient Faults

Quantum Computing is a highly promising new computation paradigm. Unfortunately, quantum bits (qubits) are extremely fragile and their state can be gradually or suddenly modified by intrinsic noise or external perturbation. In this paper, we target the sensitivity of quantum circuits to radiation-induced transient faults. We consider quantum circuit cuts that split the circuit into smaller independent portions, and understand how faults propagate in each portion. As we show, the cuts have different vulnerabilities, and our methodology successfully identifies the circuit portion that is more likely to contribute to the overall circuit error rate. Our evaluation shows that a circuit cut can have a 4.6x higher probability than the other cuts, when corrupted, to modify the circuit output. Our study, identifying the most critical cuts, moves towards the possibility of implementing a selective hardening for quantum circuits

A Densely-Deployed, High Sampling Rate, Open-Source Air Pollution Monitoring WSN

Air quality, especially particulate matter, has recently attracted a lot of attention from governments, industry, and academia, motivating the use of denser air quality monitoring networks based on low-cost sensing strategies. However, low-cost sensors are frequently sensitive to aging, environmental conditions, and pollutant cross-sensitivities. These issues have been only partially addressed, limiting their usage. In this study, we develop a low-cost particulate matter monitoring system based on special-purpose acquisition boards, deployed for monitoring air quality on both stationary and mobile sensor platforms. We explore the influence of all model variables, the quality of different calibration strategies, the accuracy across different concentration ranges, and the usefulness of redundant sensors placed in each station. The collected sensor data amounts to about 50GB of data, gathered in six months during the winter season. Tests of statically immovable stations include an analysis of accuracy and sensors’ reliability made by comparing our results with more accurate and expensive standard β radiation sensors. Tests on mobile stations have been designed to analyze the reactivity of our system to unexpected and abrupt events. These experiments embrace traffic analysis, pollution investigation using different means of transport and pollution analysis during peculiar events. With respect to other approaches, our methodology has been proved to be extremely easy to calibrate, to offer a very high sample rate (one sample per second), and to be based on an open-source software architecture. Database and software are available as open source in [1]

Understanding the Effect of Transpilation in the Reliability of Quantum Circuits

Transpiling is a necessary step to map a logical quantum algorithm to a circuit executed on a physical quantum machine, according to the available gate set and connectivity topology. Different transpiling approaches try to minimize the most critical parameters for the current transmon technology, such as Depth and CNOT number. Crucially, these approaches do not take into account the reliability of the circuit. In particular, transpilation can modify how radiation-induced transient faults propagate. In this paper, we aim at advancing the understanding of transpilation impact on fault propagation by investigating the low-level reliability of several transpiling approaches. We considered 4 quantum algorithms transpiled for 2 different architectures, increasing the number of qubits, and all possible logical-to-physical qubit mapping, adding to a total of 4, 640 transpiled circuits. We inject a total of 202, 124 faults and track their propagation. Our experiments show that by simply choosing the proper transpilation, the reliability of the circuit can improve by up to 14%

Quantum Computing tutorial

Il Quantum Computing (QC) è rimasto a lungo un’idea nell’immaginario della comunità scientifica, ma grazie agli enormi progressi degli ultimi decenni sta acquistando una credibilità crescente al punto da ritenere realistica la sua applicazione su larga scala su un orizzonte temporale relativamente vicino. I computer quantistici implementano una nuova modalità di processare le informazioni e, se la tecnologia riuscirà a rendere disponibile la capacità di calcolo che promette, potranno essere utilizzati per analizzare problemi non trattabili dai computer classici, aprendo nuove opportunità in termini di scoperte, innovazione e applicazione con impatti che potrebbero essere rivoluzionari in tutti i settori. Anche se la tecnologia non ha raggiunto ancora la piena maturità, è già conveniente utilizzare il QC eventualmente con opportuni adattamenti, capendo le modalità e le logiche della programmazione quantistica, beneficiando dei vantaggi e delle opportunità di sviluppo di nuovi use cases e di apertura di nuovi scenari. L’articolo si propone di fornire una panoramica sulle applicazioni, le tipologie di quantum computer, gli ambienti di sviluppo e la modellizzazione algoritmica per mostrare come il QC possa a tutti gli effetti essere preso in considerazione per sviluppare use case reali. In fondo il quantum non è poi così “spooky” come potrebbe sembrare

QuFI: a Quantum Fault Injector to Measure the Reliability of Qubits and Quantum Circuits

Quantum computing is a new technology that is expected to revolutionize the computation paradigm in the next few years. Qubits exploit the quantum physics proprieties to increase the parallelism and speed of computation. Unfortunately, besides being intrinsically noisy, qubits have also been shown to be highly susceptible to external sources of faults, such as ionizing radiation. The latest discoveries highlight a much higher radiation sensitivity of qubits than traditional transistors and identify a much more complex fault model than bit-flip. We propose a framework to identify the quantum circuits sensitivity to radiation-induced faults and the probability for a fault in a qubit to propagate to the output. Based on the latest studies and radiation experiments performed on real quantum machines, we model the transient faults in a qubit as a phase shift with a parametrized magnitude. Additionally, our framework can inject multiple qubit faults, tuning the phase shift magnitude based on the proximity of the qubit to the particle strike location. As we show in the paper, the proposed fault injector is highly flexible, and it can be used on both quantum circuit simulators and real quantum machines. We report the finding of more than 285M injections on the Qiskit simulator and 53K injections on real IBM machines. We consider three quantum algorithms and identify the faults and qubits that are more likely to impact the output. We also consider the fault propagation dependence on the circuit scale, showing that the reliability profile for some quantum algorithms is scale-dependent, with increased impact from radiation-induced faults as we increase the number of qubits. Finally, we also consider multi qubits faults, showing that they are much more critical than single faults. The fault injector and the data presented in this paper are available in a public repository to allow further analysis

Towards Optimal Graph Coloring Using Rydberg Atoms

Quantum mechanics is expected to revolutionize the computing landscape in the near future. Among the many candidate technologies for building universal quantum computers, Rydberg atoms-based systems stand out for being capable of performing both quantum simulations and working as gate-based universal quantum computers while operating at room temperature through an optical system. Moreover, they can potentially scale up to hundreds of quantum bits (qubits). In this work, we solve a Graph Coloring problem by iteratively computing the solutions of Maximal Independent Set (MIS) problems, exploiting the Rydberg blockade phenomenon. Experimental results using a simulation framework on the CINECA Marconi-100 supercomputer demonstrate the validity of the proposed approach

PROMET&O: A Multidisciplinary Approach to Monitor Indoor Environmental Quality

Recent studies have explored the influence of Indoor Environmental Quality (IEQ) on the occupants’ perception, behavior and productivity at work [1]. Also, it has been proved that a poor IEQ may turn in negative further consequences on occupants also affecting mental comfort and health [2]. The assessment of IEQ is thus a complex task due to its nature that considers the thermal, air quality, lighting and acoustics domains at the same time. Alongside with these aspects, there is no evidence of the extent to which exposure to day-to-day low-frequency electromagnetic fields may arise long term health issues, although international guidelines specify exposure limits for work places. Recent works, such as [3], have also investigated the use of Wireless Sensor Networks (WNSs) for air pollution monitoring, however, they typically refer to urban environment. To sum up, multi-domain investigations are therefore needed, and the use of accurate devices for the acquisition of objective IEQ metrics is mandatory. This research aims at developing an innovative, accurate and low-cost system for the in-field monitoring of IEQ, i.e., the so called PROMET&O system. With respect to the current state of the art, PROMET&O will provide the integration of the measured IEQ metrics with feedback of the perceived Indoor Environmental Comfort (IEC) from occupants, encouraging best practices for energy saving. The proposed system architecture is shown in Fig. 1 and consists in several Multi-Sensors (MSs) collecting data related to the IEQ metrics to be monitored, which are sent to an open-access platform for further processing. Each MS is provided with a set of sensors, whose outputs are periodically sampled by a controller, shown in Fig. 2. Sensors have been selected being low-cost, low-power and small-sized. The respective measurement range and accuracy are reported in Tab. 1 and agree with the specific IEQ standards. To avoid self-heating or cross-sensitivity issues, a first placement of the MS layout is proposed as shown in Fig. 3. Based on the sampled data, statistics of the measured quantities are evaluated and transferred to the server to be stored in a database. Future work will focus on further development and experimental validation of such system in an open space offices to correlate IEQ measured metrics with occupants’ feedback

Comparison of heuristic approaches to PCI planning for Quantum Computers

Quantum Computing (QC) provides the possibility to develop new approaches to tackle complex problems. Real-world applications, however, cannot yet be managed directly due to the limitation of present and near-future noisy intermediate-scale quantum (NISQ) computers. Decomposition into smaller and manageable subproblems is often needed to take advantage of QC even when using hybrid (classical-quantum) solvers or solvers that already apply decomposition techniques. In this paper, heuristic decomposition algorithms to solve the Physical Cell Identifier (PCI) problem in 4G cellular networks in a way suitable for QC are presented. The PCI problem can be viewed as a map coloring problem with additional constraints and has been represented in a Quadratic Unconstrained Binary Optimization (QUBO) model, a form that, for instance, a quantum annealing machine could crunch. We propose two strategies, with variable decomposition granularity. The first one solves the problem recursively through bisection (max-cut problem), to use only one qubit to represent the status of the objects, avoiding one-hot encoding and thus minimizing the qubit requirement. The second is a multi-step approach, finally solving sets of randomized modified max-k-cut problems of customizable qubit size. We executed the algorithms on real cellular networks of one of the main Italian national telecom operators (TIM). The results show that all proposed QUBO approaches can be effectively applied to very large problems with similar or better performance of the reference classical algorithm, paving the way for the use on NISQ computers