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ispartof: 2022 IEEE 28TH INTERNATIONAL SYMPOSIUM ON ON-LINE TESTING AND ROBUST SYSTEM DESIGN (IOLTS 2022) ispartof: 28th IEEE International Symposium on On-Line Testing and Robust System Design (IOLTS) location:ITALY, Politecnico Torino, Torino date:12 Sep - 14 Sep 2022 status: published

A wide range of modern science and engineering applications are formulated as optimization problems with a system of partial differential equations (PDEs) as constraints. These PDE-constrained optimization problems are typically solved in a standard discretize-then-optimize approach. In many industry applications that require high-resolution solutions, the discretized constraints can easily have millions or even billions of variables, making it very slow for the standard iterative optimizer to solve the exact gradients. In this work, we propose a general framework to speed up PDE-constrained optimization using online neural synthetic gradients (ONSG) with a novel two-scale optimization scheme. We successfully apply our ONSG framework to computational morphogenesis, a representative and challenging class of PDE-constrained optimization problems. Extensive experiments have demonstrated that our method can significantly speed up computational morphogenesis (also known as topology optimization), and meanwhile maintain the quality of final solution compared to the standard optimizer. On a large-scale 3D optimal design problem with around 1,400,000 design variables, our method achieves up to 7.5x speedup while producing optimized designs with comparable objectives., Comment: Accepted by IJCNN 2021

A way to grow and characterize isolated and coalesced ZnO nanorods on $p$ -GaN/sapphire structure is presented. Chemical bath deposition can be used to grow ZnO nanorods of device-quality, simply controlling the duration time of the growth process and the concentration of the nutrient solution in the bath. Increasing the duration of the process, as well as the concentration of the solution, leads to compact and sound layers instead of separated nanorods. However, too high concentrations stop the growth process. Light-emitting diodes fabricated on these ZnO-p-GaN heterostructure have a peak of electroluminescence at 400 nm and exhibit interesting electrical and optical properties. Optical power of 225 µW at 0.425 $A$ /cm2and a related wall-plug efficiency of 0.23% are obtained with 2 mm-diameter LEDs fabricated on a ZnO layer grown for 30 h in a solution of concentration 70 mM. The performances shown by these LEDs can be used as a way to test the quality of the ZnO growth.

This paper provides a detailed overview of the reliability and radiation tests (both TID and SEE) performed inside the QML-V qualification phase and a high voltage application of RHRPMICL1A IC (integrated circuit) device, a rad-hard integrated current limiter designed and developed by STMicroelectronics. The device was born from the idea of ESA to have an ICL (Integrated Current Limiter) of universal use and containing most of the components for the relevant current limiter functions (such as the Latching and Re-triggerable modes), in order to avoid recurrent re-design and implementation by using discrete components. The device has obtained recently the QML-V qualification with SMD number 5962–17211. The high voltage application, described in the second part of this paper, allows using the device in power bus of 100V or higher, as those ones required more and more in the telecom satellites. The related application tests, performed in the laboratory for the validation of the proposed solution, are also presented.

This paper provides a detailed overview of the qualification activities including the radiation tests (both TID and SEE) of the RHRPMPOL01 IC device, a radiation hardened 7A synchronous step-down monolithic switching regulator with high precision internal voltage reference and integrated power MOSFETs for synchronous conversion. The device is the outcome of a development activity entitled “Miniaturised core element for Point of Load (PoL) conversion”, ESA TRP contract n. 4000107184/12/NL/LVH with STMicroelectronics.

In this paper we describe silicon miniaturized electrochemical cells composed by three planar microelectrodes. The cells are embedded on PCB board for the electrical driving and reading. The microelectrodes are produced using the VLSI technology, in particular the counter and reference are made of gold, while the working microelectrodes was manufactured in platinum and nickel depending the application. The device contains also heater and sensors for temperature control and measurement.

Resilient systems maintain state awareness and an accepted level of operational normalcy in response to disturbances, including threats of an unexpected and malicious nature [1]. In this paper we present a resilience metric for a large scale multi-physics system. We summarize the resilience metric calculations methods from different domains and analyze the fundamental challenges for case-by-case resilience metric calculation methods. We propose to decompose complex systems into subsystems and calculate multiple performance metrics, which are then combined to determine the resilience metric. Based on the context of ship automation system, we define a normalized resilience metric, which can be estimated by the system decomposition approach. The value of the resilience metric is between 0 and 1, where 1 is the best possible resilience. In a case study presented in this paper, we consider a ship chiller system that is partially damaged due to an external event. The control strategy takes proper action to determine new configuration that maximizes the resilience metric.

This paper analyzes three different solutions for human-robot cooperation. The proposed applications are based on two sensing devices: the Microsoft Kinect, a 3D camera by Microsoft, and a Graphics Tablet. The first solution, based on the Kinect, uses hand motion detection based on a clustering hand detection algorithm. The coordinates of the hands are sent to an application that computes the inverse kinematics and the desired robot trajectory. The second solution is based on a Graphic Tablet, which uses pen or finger input and operates in a similar way as the first system, but with higher accuracy. The third solution is also based on the Kinect but it uses the detection of the human body and voice commands together, to safely move the robotic arm without the need of a traditional teach pendant. All the three solutions adopt network sockets to send the commands to the robot controller. Behind the solutions, real time security procedures, monitors and avoids any collision of the robotic arm with humans during the movements.

The paper deals with the 3D survey of Palazzo Raimondi in Cremona, featuring a renowned Renaissance facade, first step of a knowledge program aimed to define strengthening strategies consistent with the objective of building conservation. The laser-scanning campaign involved both external facades and the loggia on the court, extending to the flat coved vaults of the first floor, allowing detecting possible deviations from an ideal geometric reference. Non-destructive tests were also performed on materials and structures in order to widen the awareness on building behavior and attempt a first vulnerability analysis.

Industrial Wireless Sensor Networks (IWSNs) are found in many application domains that require low latency, robustness, and determinism. The IEEE 802.15.4 standard is not able to cope with the requirements of these applications. For this reason, the IEEE 802.15.4e amendment was introduced, which provides novel MAC-layer profiles that are optimized for a broad range of application domains, including process automation. This paper focuses on two of these profiles, i.e., the Deterministic and Synchronous Multi-channel Extension (DSME) and the Time Slotted Channel Hopping (TSCH). The aim of the paper is twofold. First, assessing their behavior in realistic process automation scenarios. Second, comparing their performance in terms of end-to-end delay, reliability and scalability. The ultimate aim of the work is identifying the limits of those protocols, thus paving the way to further work addressing suitable approaches to tackle them.

Today ultra-flexible electronic devices can be successfully embedded in smart clothes, integrated in transparent displays, hidden in tubular structures to increase the numbers of sensors in an urban space or in a specific environment, thus enhancing the interaction of a person and maximizing the shared amount of available information. Coupling this technology with nanostructures based sensing devices is a further step to revolutionize the idea of distributed smart objects. Polysilicon based materials on plastic is a mature technology to fabricate electronic read-out circuits suitable to manage and control the signals coming from sensors of different nature, conceiving new applications and wearable solutions. Moreover, the possibility of directly integrating active devices together with sensors reduces issues related to signal to noise ratio, providing a local preamplification.

This paper proposes a Lightweight version of the Precision Time Protocol, called L-PTP, for implementation on Powerline communication systems. The aim of this novel protocol is to reduce the number of messages exchanged to achieve synchronization, without penalizing its quality. L-PTP introduces several modifications to the original PTP and can be implemented on COTS devices. The paper focuses on the protocol and on the benefits of its combination with a virtual clock computation performed by a dynamic clock synchronization algorithm.

This paper presents a motion capture system which provides both an accurate measurement of some motion parameters of a human arm and a graphical reconstruction of the movement on a synthetic model. The hardware uses several MEMS inertial sensors whose data are processed using mathematical tools based on quaternions. Measurements on a prototype have proven the system to be very accurate, since through the sensors placed on the joints of the arms it was possible to extract a video motion very faithful to the real.

This paper deals with load management in flexible industrial networks, characterized by a hybrid wired/wireless architecture and mobile wireless nodes. Our target scenario is an industrial network, in which data is exchanged between sensors and actuators running on the wireless side and a wired automation network. As many unpredictable elements affect the performance of wireless data transmission, it is necessary to control the load over the different Access Points (AP) through dynamic balancing policies. In traditional WLANs, one station selects the AP to connect with on the basis of the received signal strength indicator (RSSI). This approach may cause all active mobile stations to connect to a small subset of the APs and saturate their capacity, while other APs may still be underloaded. This paper shows a dynamic technique to manage the unbalanced load caused by moving nodes and fluctuating channel characteristics. Simulation results highlight the advantage of the proposed technique over the standard AP selection mechanism and another load balancing approach in the literature.

Clock synchronization is an important feature in Wireless Sensor Networks, as a common vision of time can be required in order to perform synchronous operations. In this paper we present a new version of the Dynamic Continuous Clock Synchronization protocol which offers a greater robustness and requires less power than the original protocol. The role of the Reference Node which sends periodic snapshots necessary for the synchronization is in turn assigned to different slaves under the control of the time Master. The discussion in the paper explains the features and the advantages of this approach. The measurements performed on a testbed point out the effectiveness of the new protocol and its suitability for real applications.

Gesture recognition has been extensively investigated and has traditionally been accomplished by methods based on computer vision. In this paper we present an hand gesture recognition system which is of general use and can be used for different applications. The system is based on a MEMS accelerometer and it is able to recognise several gestures which have been previously recorded into a suitable vocabulary.

Power Line Communication Networks (PLCN) represent a very attractive communication system which can be used for many applications in the area of both home/building automation and street lighting control. The main problem is how to organize the many nodes, in order to implement a network where all nodes can exchange information with a master node. In this paper a tree-based clustering approach is introduced and discussed. The approach has been tested on a real power line system and some operational tests and evaluations have been performed.

This paper presents a novel frequency hopping management mechanism for Bluetooth networks used in industrial environments. In these contexts, time-critical transmissions have to be supported by the automation network. Transmission timeliness can be compromised by interference between co-located cells, that increases the delay because of retransmissions. The paper introduces a novel mechanism, called a Piconet Management Approach, based on an innovative frequency hopping methodology which reduces the interference among co-located piconets, thus improving the network performance in terms of transmission delay and throughput. The paper describes the approach and discusses its performance.

Application of wireless technologies in Industrial communication claims for timely data delivery, since many applications are based on processes with real-time constraints. Currently, the 802.11B is the most used wireless protocol in the industrial applications area but it is not the ideal solution owing to the contention for medium access which can cause unbounded delays. In this paper the authors discuss the use of a token based approach as a possible solution and present the WTB protocol which is a middleware located over the 802.11B protocol. The analysis and the measurements performed on a real testbed have shown the potentiality of this approach which is able to support both the real-time and non real-time traffic still maintaining the delay within suitablel bounds.

Performance evaluation via simulation requires to create models that are often difficult and are not able to faithfully reflect the operating conditions. This paper discusses an approach based on the integration of trace files into an OMNeT + + model. This approach allows to represent and evaluate complex systems by simple models. Moreover, in the case a simulation model of the communication system is not available, a trace file can efficiently substitute it. The results obtained with reference to a specific case study confirm the validity of the proposed approach and the advantages it offers over using just simulators.

Evolution of electrically active dose, sheet resistance and hole mobility has been investigated for high B concentration profiles in pre-amorphized Si. For this purpose, Hall measurements combined with atomistic simulations have been performed. An apparent anomalous behavior has been observed for the evolution of the active dose and the sheet resistance, in contrast to opposite trend evolutions reported previously. Our results indicate that this anomalous behavior is due to large variations in hole mobility with active dopant concentration, much larger than that associated to the classical dependence of hole mobility with carrier concentration. Simulations suggest that hole mobility is significantly degraded by the presence of a large concentration of boron-interstitial clusters, indicating the existence of an additional scattering mechanism.

In this paper we compare three clock synchronization protocols for Wireless Sensor Networks and evaluate their performances under different operating conditions. The “Dynamic Continuous Clock Synchronization” (DCCS), here is compared with the “Reference Broadcast Synchronization” (RBS) and the “Continuous Clock Synchronization” (CCS). The performance evaluation of the three protocols has been carried out via simulation using the OMNeT++ discrete event simulation system. Synchronization is a key aspect in WSNs but some features such as the limited bandwidth, hardware and energy available, as well as the nature of the wireless medium, make a good synchronization a challenging objective. We performed a set of simulations to evaluate how the protocols behave by varying some influent factors, and compared the results obtained in order to achieve information useful to select the most suitable protocol for a specific application.

In this paper we focus on the problems related to the management of a farm made up of several greenhouses. Management of this kind of farms requires data acquisition in each greenhouse and their transfer to a control unit which is usually located in a control room, separated from the production area. At present, data transfer between the greenhouses and the control system is mainly provided by a suitable wired communication system, such as a Fieldbus. In such contexts, even though the replacement of the wired system with a fully wireless one can appear very attractive, a fully wireless system can introduce some disadvantages. A solution based on a hybrid wired/wireless network, where CAN and ZigBee protocols are used, is presented along with all the related problems that this integration involves. In particular, in order to integrate the wireless section with the wired one at the Data Link Layer, a suitable multi-protocol bridge has been implemented, while, at the application layer, a porting of SDS services on ZigBee, which we called ZSDS, allows us to access the network resources independently from the network segment they are connected to.

This paper addresses the performance evaluation of a full duplex wireless protocol for an industrial backbone making a comparison with the traditional IEEE802.11 half duplex protocol. A Petri net model is used as the basis for the evaluation. The paper first examines the features of a wireless backbone and some issues they impose. Then, the paper describes the limits of the 802.11 and the solution here proposed which is based on the use of full duplex wireless links and discusses the PN models. At last the results of the performance evaluation are presented and the advantages offered by the full duplex solution are discussed.