A Performance Analysis of Security Protocols for Distributed Measurement Systems Based on Internet of Things with Constrained Hardware and Open Source Infrastructures.

The widespread adoption of Internet of Things (IoT) devices in home, industrial, and business environments has made available the deployment of innovative distributed measurement systems (DMS). This paper takes into account constrained hardware and a security-oriented virtual local area network (VLAN) approach that utilizes local message queuing telemetry transport (MQTT) brokers, transport layer security (TLS) tunnels for local sensor data, and secure socket layer (SSL) tunnels to transmit TLS-encrypted data to a cloud-based central broker. On the other hand, the recent literature has shown a correlated exponential increase in cyber attacks, mainly devoted to destroying critical infrastructure and creating hazards or retrieving sensitive data about individuals, industrial or business companies, and many other entities. Much progress has been made to develop security protocols and guarantee quality of service (QoS), but they are prone to reducing the network throughput. From a measurement science perspective, lower throughput can lead to a reduced frequency with which the phenomena can be observed, generating, again, misevaluation. This paper does not give a new approach to protect measurement data but tests the network performance of the typically used ones that can run on constrained hardware. This is a more general scenario typical for IoT-based DMS. The proposal takes into account a security-oriented VLAN approach for hardware-constrained solutions. Since it is a worst-case scenario, this permits the generalization of the achieved results. In particular, in the paper, all OpenSSL cipher suites are considered for compatibility with the Mosquitto server. The most used key metrics are evaluated for each cipher suite and QoS level, such as the total ratio, total runtime, average runtime, message time, average bandwidth, and total bandwidth. Numerical and experimental results confirm the proposal's effectiveness in foreseeing the minimum network throughput concerning the selected QoS and security. Operating systems yield diverse performance metric values based on various configurations. The primary objective is identifying algorithms to ensure suitable data transmission and encryption ratios. Another aim is to explore algorithms that ensure wider compatibility with existing infrastructures supporting MQTT technology, facilitating secure connections for geographically dispersed DMS IoT networks, particularly in challenging environments like suburban or rural areas. Additionally, leveraging open firmware on constrained devices compatible with various MQTT protocols enables the customization of the software components, a crucial necessity for DMS.

Local Distributed Node for Power Quality Event Detection Based on Multi-Sine Fitting Algorithm.

The new power generation systems, the increasing number of equipment connected to the power grid, and the introduction of technologies such as the smart grid, underline the importance and complexity of the Power Quality (PQ) evaluation. In this scenario, an Automatic PQ Events Classifier (APQEC) that detects, segments, and classifies the anomaly in the power signal is needed for the timely intervention and maintenance of the grid. Due to the extension and complexity of the network, the number of points to be monitored is large, making the cost of the infrastructure unreasonable. To reduce the cost, a new architecture for an APQEC is proposed. This architecture is composed of several Locally Distributed Nodes (LDNs) and a Central Classification Unit (CCU). The LDNs are in charge of the acquisition, the detection of PQ events, and the segmentation of the power signal. Instead, the CCU receives the information from the nodes to classify the PQ events. A low-computational capability characterizes low-cost LDNs. For this reason, a suitable PQ event detection and segmentation method with low resource requirements is proposed. It is based on the use of a sliding observation window that establishes a reasonable time interval, which is also useful for signal classification and the multi-sine fitting algorithm to decompose the input signal in harmonic components. These components can be compared with established threshold values to detect if a PQ event occurs. Only in this case, the signal is sent to the CCU for the classification; otherwise, it is discarded. Numerical tests are performed to set the sliding window size and observe the behavior of the proposed method with the main PQ events presented in the literature, even when the SNR varies. Experimental results confirm the effectiveness of the proposal, highlighting the correspondence with numerical results and the reduced execution time when compared to FFT-based methods.

Evaluation of the Effects of Mobile Smart Object to Boost IoT Network Synchronization.

This paper deals with the synchronization of Mobile Smart Objects (MSOs). Today, this scenario is becoming typical in Industrial IoT applications due to the plethora of MSOs available as robots, drones and wearables, equipped by sensors making them measurement instruments cooperating in distributed measurement systems. In this context, the synchronization accuracy is directly tied with the accuracy of the performed measurements. In hierarchical synchronization approaches, the presence of an MSO makes the network topology time varying, and this could prevent the synchronization of the whole network. Peer to peer approaches do not need node hierarchy to synchronize but could not converge to a common sense of time. To overcome these challenges, this paper proposes a consensus-based approach for which the convergence to a common sense of time is here demonstrated. The proposal deploys the MSO to bring the common sense of time from an SO to another, establishing new paths among SOs. The new paths are temporary and depend on the MSO's route. In the paper, the influence of the MSO's route on the synchronization accuracy σ and the time interval to synchronize all the SOs ∆TIS is investigated, also. The mathematical proof, the simulations and the experimental tests confirm that the MSO can reduce both the values of σ and ∆TIS, because the new connections introduced by the MSO can boost the exchange of information among SOs. Consequently, the criteria to a priori select the route ameliorating σ and ∆TIS values are proposed.

Totally implantable central venous access devices in adult oncological patients.

Totally implantable vascular access devices (ports) were introduced into clinical practice to replace external catheters in patients undergoing prolonged intravenous therapy. Today, they are also designed to provide repeated access to the vascular system for the delivery of blood products and are also used for the withdrawal of blood samples. As regards cancer patients, the availability of these continuous reliable intravenous catheterisation devices has provided an opportunity to deliver more complex, multi-drug regimens, in safety and with a good quality of life. One hundred and eight patients underwent the subcutaneous positioning of a totally implanted reservoir (via the right subclavian vein) for aggressive combination chemotherapy in an operating room suite, using local anaesthesia. No patients suffered from air embolism, severe bleeding, brachial plexus injury, cardiac tamponade, haemothorax or hydrothorax. No patients experienced catheter occlusion or catheter-related venous thrombosis. One patient suffered from a pocket infection. Two patients experienced pneumothorax, but neither of them required catheter removal or required chest drainage. Indications, contraindications and complications are discussed. With careful routine care, totally subcutaneously implanted ports are very safe and provide reliable access to the venous system.

Endovenous laser therapy combined with a surgical approach for primary varicose veins of the lower limbs.

In recent years, the minimal invasive alternatives to surgical ligation and stripping for the treatment of an incompetent greater saphenous vein have been explored. Endovenous laser therapy (EVLT) is one of these therapeutic options. We report on our initial experience with endovenus laser therapy combined with a surgical approach. Over the period from September 2006 to September 2007, in the Colleferro City Hospital General Surgery Department, 19 patients were submitted to endovenous laser therapy combined with a surgical approach. We opted for a combined technique in which the use of the laser was preceded by high ligation of the saphenous vein ("crossectomy") together with complete sectioning of the venous collaterals. We observed no severe complications and endovenous laser therapy proved safe and easy to perform. However, this study is too limited and too short in terms of follow-up and number of patients to establish the superiority of the procedure over stripping in terms of recurrences. Endovenous laser therapy seems promising, but larger numbers and longer follow-up are needed to suggest this technique as the best approach to the management of varicose vein disease.

Pancreatic pseudocyst caused by extracorporeal shock wave lithotripsy for right renal pelvic calculi.

A 39-year-old white man with a history of right renal pelvic stones treated 1 year before by extracorporeal shock wave lithotripsy, but with no history of major surgery, alcoholism, pancreatitis, hyperparathyroidism or trauma, was admitted, suffering from an abdominal mass. Abdominal and pelvic computed tomography revealed an enlarged pancreatic head (9 cm in transverse diameter) with, inside it, a heterogeneous, cyst-like structure, measuring 7 cm in diameter. It was suspected that this lesion was a cystic neoplasm and the patient underwent a proximal pancreaticoduodenectomy and a cholecystectomy. After the operation, the microscopic findings ruled out the presence of a neoplasm and we were obliged to reconsider the case. Speculating as to the possible role of past extracorporeal shock wave lithotripsy in determining the pancreatic pseudocyst, it was found that damage to the intra-abdominal organs during extracorporeal shock wave lithotripsy has been mentioned in published series, but it was also noted that this case seemed to differ from the other published cases, where cirrhosis and thrombocytopenia, gallbladder stones, or adhesions between the pancreas and surrounding tissue caused by laparotomy were considered the causes of the lithotripsy complications. We suggest a direct traumatic disruption of the pancreas as a result of the extracorporeal shock wave lithotripsy and conclude that the post-lithotripsy follow-up should include periodic ultrasonographic investigation of the pancreas and serum amylase level determinations in order to diagnose pancreatic complications, if any, and plan the correct treatment.