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This paper investigates an observer-based state estimation issue for discrete-time semi-Markovian jump neural networks with Round-Robin protocol and cyber attacks. In order to avoid the network congestion and save the communication resources, the Round-Robin protocol is used to schedule the data transmissions over the networks. Specifically, the cyber attacks are modeled as a set of random variables satisfying the Bernoulli distribution. On the basis of the Lyapunov functional and the discrete Wirtinger-based inequality technique, some sufficient conditions are established to guarantee the dissipativity performance and mean square exponential stability of the argument system. In order to compute the estimator gain parameters, a linear matrix inequality approach is utilized. Finally, two illustrative examples are provided to demonstrate the effectiveness of the proposed state estimation algorithm. [ABSTRACT FROM AUTHOR]

This paper is concerned with the problem of fixed-time consensus tracking for a class of nonlinear multi-agent systems subject to unknown disturbances. Firstly, a modified fixed-time disturbance observer is devised to estimate the unknown mismatched disturbance. Secondly, a distributed fixed-time neural network control protocol is designed, in which neural network is employed to approximate the uncertain nonlinear function. Simultaneously, the technique of command filter is applied to fixed-time control, which circumvents the "explosion of complexity" problem. Under the proposed control strategy, all agents are enable to track the desired trajectory in fixed-time, and the consensus tracking error and disturbance estimation error converge to an arbitrarily small neighborhood of the origin, meanwhile, all signals in the closed-loop system remain bounded. Finally, a simulation example is provided to validate the effectiveness of the presented design method. [ABSTRACT FROM AUTHOR]

Evaluate the differences between clinical visual acuity (VA) as recorded in medical records and electronic Early Treatment Diabetic Retinopathy Study (eETDRS) protocol VA measurements and factors affecting the size of the differences. Retrospective chart review. Study and fellow eyes of participants enrolled in DRCR Retina Network Protocols AC and AE (diabetic macular edema), and W (nonproliferative diabetic retinopathy) with clinical VA recorded within 3 months before the protocol visit. Differences and their association with patient and ocular factors were evaluated using linear mixed models with random effects for correlations within sites and participants. Difference between VA letter scores measured by eETDRS during a study visit versus measured by Snellen during a regular clinical visit (Snellen fraction converted to eETDRS). Data from 1016 eyes (511 participants) across 74 sites were analyzed. The mean VA measurements were 68.6 letters (Snellen equivalent 20/50) at the clinical visit and 76.3 letters (Snellen equivalent 20/32) at the protocol visit, with a mean (standard deviation [SD]) of 26 (21) days between visits. Mean (SD) protocol VA was better than clinical VA by 7.6 (9.6) letters overall, 10.7 (12.6) letters in eyes with clinical VA ≤ 20/50 (n = 376), and 5.8 (6.6) letters in eyes with clinical VA ≥ 20/40 (n = 640). On average, the difference between clinical and protocol VA was 1.3 letters smaller for every 1-line (5 letters) increase in clinical VA (P < 0.001). Mean (SD) differences by clinical correction of refractive error were 3.9 (9.0) letters with refraction, 6.9 (9.2) letters with glasses/contact lenses, 7.9 (11.5) letters with pinhole, and 9.8 (9.3) letters without correction (P = 0.06). On average, clinical Snellen VA is 1 to 2 lines worse than eETDRS protocol refraction and VA testing, which may partly explain why clinical practice does not always replicate clinical trial results. Eyes with lower clinical measurements and eyes tested without clinical refraction tended to have larger differences. Considering the potential discrepancies between clinical and protocol VA measurements, refracting eyes in the clinic may benefit patients when determining treatment plans and study referrals based on vision. Proprietary or commercial disclosure may be found after the references. [ABSTRACT FROM AUTHOR]

When controlling cyber–physical systems via consensus algorithms, the robustness issue is of paramount importance because of model mismatching and/or disturbances that generally modify the Laplacian flow dynamics associated to the overall network, compromising the possibility to achieve any expected, orchestrated emergent behavior. To face this issue, the Variable Structure Control (VSC) approach has recently been shown to be an effective tool in designing control protocols over networks, providing robustness and often yielding finite-time convergence. Moreover, VSC further enables the decoupling of simultaneous control objectives where reaching a consensus state is only part of a more complex task, for instance as it happens in distributed optimization. Thus motivated, this paper overviews, from a tutorial perspective, some selected recent advances in the application of VSC with Sliding Modes to design robust consensus controllers in both the leader-less and the leader-following settings. Efforts are also made to unify the notation and to discuss the theoretical foundations of the nonsmooth analysis tools at the basis of their design for a wide readership unfamiliar with these problems and formal tools. To this aim, examples supporting the treatment, and numerical simulations, are given and discussed in detail. Finally, hints for future investigations along with some current open problems are provided. [ABSTRACT FROM AUTHOR]

This paper considers the reliable state estimation issue for discrete-time neural networks with the try-once-discard (TOD) scheduling protocol and mixed compensation strategy. For the phenomenon of medium access constraint, the measurement transmitted from sensors to the estimator is subjected to the TOD scheduling protocol. The mixed compensation is proposed to flexibly compensate those missing measurements caused by the TOD protocol. By using a novel polytopic uncertain model, a reliable state estimator is designed, where the gain matrix is determined by two vertex matrices. Then sufficient conditions are established, which ensure the error system meets the stochastic stability and the l 2 - l ∞ performance. Finally, an illustrative example shows the validity of the proposed reliable state estimator. [ABSTRACT FROM AUTHOR]

• 31 years of Birch pollen records in the northwestern Iberian Peninsula. • Precipitation in early spring delays the onset of the pollen period. • Pollen intensity in the last decades is increasing. • Temperature during the pollen period affects each locality differently. • Pre-summer temperature increases pollen intensity at all studies locations We studied the relationship between the occurrence of airborne pollen of Betula spp. and climate, during the main pollination season, as well as before the pollen season and in the preceding year. Our aim was to understand how environmental conditions could influence the main pollen season and the intensity of airborne pollen presence at the meridional boundary of the Betula forest distribution in Europe. For this purpose, pollen monitoring was conducted using Lanzoni VPPS 2000 volumetric trap and weather data from the nearest meteorological station. The study area was located in the northwest of the Iberian Peninsula, specifically in three areas with diverse mesoclimate: Vigo (Atlantic), Ourense (Mediterranean) and Lugo (Cantabrian), which had a distinct oceanic influence. Aerobiological analysis was conducted based on the Spanish aerobiology network protocol. Data on precipitation, maximum, minimum and mean temperature were selected for three time windows: 1st the main pollen season period, 2nd from 5 to 90 days before the onset of pollen presence, with a cumulative five-day interval, and 3rd the average monthly climate of the previous year. Precipitation delays the onset of the main pollination season as well as the end of the season, increasing pollen counts in the post-peak interval at all three sites. Temperature during the pollen season affects duration and pollen integral differently among sites. The pollen integral shows an increasing trend over the last decade's at all three areas. The rise trend detected in the minimum temperature of the previous summer explains these increases in the three sites. In conclusion, the effect of climate prior to and during the main pollen season have varied effects on date-related data across mesoclimates, while temperature during bud floral primordia development can be considered as a timeframe for predicting pollen intensity in the following year through the entire area. [ABSTRACT FROM AUTHOR]

Developing a highly efficient multi-node media access control protocol tailored for ultraviolet (UV) networks poses a significant challenge. While our team's UV random-access collaborative networking protocol, utilizing time-division multiple access (UVCN-TDMA), has been instrumental, its scalability is hindered by the number of network nodes. To address this limitation and facilitate large-scale UV node networking, this study advances the UVCN protocol by introducing an enhanced collaborative networking protocol known as the enhanced collaborative clustering mechanism (eCOCM). This study examined the impact of network topology, various data services, and the number of cluster nodes on network performance within the proposed eCOCM framework. Additionally, a comparative analysis between the eCOCM protocol and conventional clustering systems was conducted. The findings demonstrate notable enhancements across key performance metrics including throughput, packet loss rate, delay, and channel utilization. Finally, functional experiments were conducted under two distinct network scenarios to validate the efficacy of the proposed protocol. This study addresses the immediate challenges in UV multi-node networking and offers pragmatic insights to steer its development forward. • This study proposes an enhanced collaborative networking protocol based on a clustering mechanism (eCOCM) to cope with large-scale Ultraviolet (UV) node networking. • The effects of network topology, types of data services, and number of cluster nodes on network performance under the proposed protocol were analyzed. The protocol was compared with the clustering system. The results reveal that it achieves improved throughput, packet loss rate, delay, and channel utilization performance. • Functional experiments were performed in two network scenarios. The operational status of the eCOCM protocol was analyzed in detail based on the output and input signal waveforms of the UV nodes, and the experimental results fully confirm the validity of the protocol. [ABSTRACT FROM AUTHOR]

Pre-trained models such as BERT have made great achievements in natural language processing tasks in recent years. In this paper, we investigate the privacy-preserving pre-training based neural network inference in a two-server framework based on additive secret sharing technique. Our protocol allows a resource-restrained client to request two powerful servers to cooperatively process the natural processing tasks without revealing any useful information about its data. We first design a series of secure sub-protocols for non-linear functions used in BERT model. These sub-protocols are expected to have broad applications and of independent interest. Based on the building sub-protocols, we propose SecBERT, a privacy-preserving pre-training based neural network inference protocol. SecBERT is the first cryptographically secure privacy-preserving pre-training based neural network inference protocol. We show security, efficiency and accuracy of SecBERT protocol through comprehensive theoretical analysis and experiments. [ABSTRACT FROM AUTHOR]

This paper proposes a distributed protocol for tracking the global maximum supremum (or minimum infimum) of a set of exogenous time-varying signals. Specifically, each agent has only access to one of these signals and, by implementing the proposed protocol, it is able to track in finite-time the maximum supremum (or the minimum infimum) of the exogenous time-varying signals in a distributed fashion. No assumption is made on the network size and, remarkably, the communication graph is directed (possibly switching) with the only requirement to be strongly connected at all times. The behavior of the protocol with open networks is discussed and numerical simulations are provided to corroborate the theoretical findings. [ABSTRACT FROM AUTHOR]

Quantum network coding can effectively alleviate bottlenecks in quantum networks thus improving the transmission efficiency and the throughput of the quantum network. Although various quantum network coding protocols have been constructed, most of them focus mainly on addressing the communication congestion issue of simultaneously transmitting single-qubit states via the bottleneck channel in quantum networks. In this paper, a protocol for the quantum two-pair unicast transmission of multi-particle states using quantum time-bin multiplexing is proposed. Parallel entanglement is established in a heralded way between two-dimensional quantum memories (QMs) of intermediate nodes by transmitting a high-dimensional encoded single photon via the bottleneck channel. Then the quantum unicast transmission of multi-particle states can be achieved by using quantum teleportation and the resultant entangled pairs. Additionally, a security enhanced protocol is presented when dishonest intermediate nodes or outside eavesdroppers are taken into account. No alternative measurements are needed to check security. This makes the present protocol cost-effective and efficient. Compared with existing methods, no pre-shared entangled states are required. This provides a new perspective for the development of quantum networks. [ABSTRACT FROM AUTHOR]

Filtered Smith predictors are well established for controlling linear plants with constant time delays. Apart from this classical application scenario, they are also employed within networked control loops, where the measurements are sent in separate packets over transmission channels that are subject to time-varying delays. Consequently, classical tools for the stability analysis, e.g., for time delay systems, have to be extended to facilitate an explicit consideration of network-induced effects such as packet skipping and disordering of sent packets. The present paper illustrates that the time-varying delays and, particularly important, the packetized character of the transmissions have to be explicitly taken into account for the stability analysis. Three network protocols, which use different packet selection and hold mechanisms, are considered to state criteria for the robust stability of the networked feedback loops with filtered Smith predictors. They are based on the small gain theorem and allow a computationally inexpensive way to check stability for the case with uncertain plant models and bounded time-varying packet delays in the communication channels. • Filtered Smith predictor for packet-based networked systems. • Communication network with bounded and time-varying packet delays. • Three different network protocols (different packet skipping and hold mechanisms). • Easy-to-use stability analysis for uncertain plants and time-varying packet delays. [ABSTRACT FROM AUTHOR]

Industrial Internet-of-Things systems suffer from a vast and vulnerable attack surface, raising widespread concerns about shielding IIoT devices from malicious attacks and reducing cyber risks. Device identification is the prerequisite to safeguard IIoT systems. We leverage the observation that IIoT network protocol implementations vary due to different hardware architectures/configurations and design tasks of IIoT devices, which cause the difference in their network traffic payloads. Specifically, we develop a novel neural network to learn the semantic/syntax features among multiple IIoT packets. The neural network has multiple branches, each of which consists of convolution layers, attention modules, and highway units for learning the classification model of IIoT devices. To validate the precision and recall of our neural network in IIoT devices fingerprinting, we have implemented a prototype of the proposed IIoT device identification system. Our results show that our approach achieves 95.8% precision and 95.4% recall, significantly outperforming other classification models. • We propose a novel IIoT fingerprinting approach based on neural network. • We conduct experiments to validate the effectiveness of it. • The results show that our approach can achieve 95.8% precision. • We demonstrate the usefulness of fingerprinting in application. • Our approach is useful in shielding industrial systems. [ABSTRACT FROM AUTHOR]

Time cost is an important indicator for evaluating the control protocol of the designed network system. The issue of flocking in Cucker–Smale type models is investigated in this article. Two new switching protocols are articulated to achieve finite-time (FT) and fixed-time (FDT) flocking. Sufficient conditions and the upper bounds of time cost (TC) for flocking are obtained. The influence of parameters and group size on TC is revealed. Especially, the new control strategy proposed successfully reduces the convergence time compared to the general FT and FDT control protocols. • The new switching protocols can ensure the Cucker–Smale type models achieve finite-time and fixed-time flocking. • The upper bound estimation of flocking time cost convincingly illustrates that the models achieve flocking faster. • It is revealed that the time cost is closely related to both the control parameters and the group size. [ABSTRACT FROM AUTHOR]

In this paper, the output feedback H ∞ control is investigated for the networked singularly perturbed systems (SPSs) with Markov lossy network, in which the packet loss probability varies in different modes. A new network mode-dependent round-robin-like protocol (RRLP) is introduced to the networked SPSs, which can dynamically adjust the number of the selected sensor nodes according to the network environment condition. Based on this RRLP and Markov lossy network, a Markov mode and scheduling order co-dependent output feedback controller is constructed to ensure the system control performance. By constructing a novel Lyapunov-Krasovskii functional dependent on the singular perturbation parameter, Markov mode, and scheduling order simultaneously, sufficient conditions of mean square stability for SPSs are obtained, and numerical stiffness is avoided. Finally, a direct current motor-controlled inverted pendulum example is proposed to verify the effectiveness of our main results. • Compared with the conventional RRP, a network mode-dependent RRLP is first introduced into SPSs, by which the number of scheduled sensors can be adjusted appropriately according to different network environments. • Based on the Markov lossy network and multi-node RRP, a novel output feedback controller is designed, which can effectively improve the control performance of system. • By constructing a new Lyapunov-Krasovskii functional dependent on SPP, Markov mode, and scheduling order simultaneously, the sufficient condition of the mean square stability is obtained for SPSs. [ABSTRACT FROM AUTHOR]

• A dynamic-distributed structure is designed as a satellite organizational structure. • An improved contract network protocol under the dynamic-distributed structure is proposed. • A blackboard model mechanism is proposed to coordinate the satellites under uncertainty. • An online single-satellite scheduling algorithm is designed. • The applicability of the proposed methods to different implementations of problems is studied. To meet the demand for real-time response to emergent events in the uncertain environment, the multi-autonomous-satellite system with real-time inter-satellite links and on-board scheduling capability has been proposed. This paper focuses on the multi-autonomous-satellite coordination and scheduling problem which is formulated by a novel mathematical model based on the multi-agent system (MAS). To solve the problem, we firstly analyze general organizational structures for the MAS and propose a new dynamic-distributed organizational structure. For these different structures, an improved contract network protocol (ICNP) and a blackboard model (BM) negotiation mechanism are proposed to coordinate the satellites. Then, an online single-satellite scheduling algorithm is proposed to schedule the tasks. In the experiments, we build up a multi-satellite system to analyze the performance of different autonomous coordination mechanisms. Experimental results indicate that the ICNP mechanism can increase the total revenue and reduce the inter-satellite communication cost. In scenarios where satellites could break down randomly, the BM can reduce the revenue losses and the number of task failures efficiently, which proves the good performance of the proposed methods in terms of robustness. The proposed methods have important practicality in the real application of the multi-autonomous-satellite system. [ABSTRACT FROM AUTHOR]

To evaluate pneumatic vitreolysis (PVL) in eyes with vitreomacular traction (VMT) with and without full-thickness macular hole (FTMH). Two multicenter (28 sites) studies: a randomized clinical trial comparing PVL with observation (sham injection) for VMT without FTMH (Protocol AG) and a single-arm study assessing PVL for FTMH (Protocol AH). Participants were adults with central VMT (vitreomacular adhesion was ≤3000 μm). In Protocol AG, visual acuity (VA) was 20/32 to 20/400. In Protocol AH, eyes had a FTMH (≤250 μm at the narrowest point) and VA of 20/25 to 20/400. Pneumatic vitreolysis using perfluoropropane (C 3 F 8) gas. Central VMT release at 24 weeks (Protocol AG) and FTMH closure at 8 weeks (Protocol AH). From October 2018 through February 2020, 46 participants were enrolled in Protocol AG, and 35 were enrolled in Protocol AH. Higher than expected rates of retinal detachment and tear resulted in early termination of both protocols. Combining studies, 7 of 59 eyes (12% [95% CI, 6%–23%]; 2 eyes in Protocol AG, 5 eyes in Protocol AH) that received PVL developed rhegmatogenous retinal detachment (n = 6) or retinal tear (n = 1). At 24 weeks in Protocol AG, 18 of 23 eyes in the PVL group (78%) versus 2 of 22 eyes in the sham group (9%) achieved central VMT release without rescue vitrectomy (adjusted risk difference, 66% [95% CI, 44%–88%]; P < 0.001). The mean change in VA from baseline at 24 weeks was 6.7 letters in the PVL group and 6.1 letters in the sham group (adjusted difference, –0.8 [95% CI, –6.1 to 4.5]; P = 0.77). In Protocol AH, 10 of 35 eyes (29% [95% CI, 16%–45%]) achieved FTMH closure without rescue vitrectomy at 8 weeks. The mean change in VA from baseline at 8 weeks was –1.5 letters (95% CI, –10.3 to 7.3 letters). In most eyes with VMT, PVL induced hyaloid release. In eyes with FTMH, PVL resulted in hole closure in approximately one third of eyes. These studies were terminated early because of safety concerns related to retinal detachments and retinal tears. [ABSTRACT FROM AUTHOR]

The future network is expected to support extremely large bandwidth, ultra-low latency or deterministic delay, extremely high reliability, and massive connectivity for novel forward-looking scenarios. As one of the most fundamental parts of the network, routing plays a vital role in a well-performed network. Recently, some new techniques using machine intelligence to optimize the network routing have been proposed. Although they have demonstrated great potential to improve the network performance, it is still a great challenge to apply machine intelligence-based routing in real network environment due to the limitations of current network architectures and protocols. Fortunately, the future network research program is on-going for designing new network paradigms, which provides an opportunity to address those limitations. In this paper, we investigate state-of-the-art techniques in machine intelligence-enabled network routing and discuss the development trends of machine intelligence-enabled routing optimization techniques for the future network. [ABSTRACT FROM AUTHOR]

Constand-round secure multi-party computation enables a group of mutually distrustful parties to jointly compute a function of their inputs in a constant-round of communication. In recent years, the constant-round secure multi-party computation protocol has improved the efficiency of the online phase by completing the multiplication computation in advance of the online phase through the Beaver triples generated in the preprocessing phase. However, the preprocessing phase of these protocols is extremely overhead-intensive and there is room for improvement. In this paper, we propose an active, constant-round secure multi-party computation (MPC) protocol which can tolerate arbitrary n − 1 corruptions. At the high level, we follow the Tiny-OT protocol and the unauthenticated garbling for garbled circuits in the preprocessing phase presented by Carmit Hazay and Peter Scholl (ASIACRYPT 2017). Particularly, we first present a new optimized Tiny-OT protocol for generating Beaver (AND) triples which is more efficient than the previous protocol, and then combine the information generated by Tiny-OT to construct an unauthenticated garbled circuit. To be precise, we also reduce the number of commitments and hash function calls in the correctness check of AND triples, and avoid using additional OT operations to compute the circuit, thus further improving communication efficiency. Our new constant-round MPC protocol has a communication complexity O (| C | Bnk) per party. Moreover, we further provide solutions to the open problem of introducing the half-gate technique into multi-party distributed garbled, which will reduce half size of the garbled table per gate. [ABSTRACT FROM AUTHOR]

The growth in the usage of the Internet of Things (IoT) has resulted in the deployment of diverse networks. However, the multiple networking interfaces and embedded protocols pose a significant challenge to communication compatibility. To tackle this problem and establish a flexible networking framework, we propose the implementation of a general-purpose message parser utilizing a recurrent neural network model with stack memory (RNN-SM). This parser has the ability to extract crucial keywords from the various communication network messages, which are trained on multiple network protocol specifications. During the training phase, the RNN-SM predicts candidate keywords and cross-references them with predefined keywords in an expandable dictionary, thus improving the accuracy of keyword extraction. Additionally, we have introduced the concept of minimum prediction fork level as a hyperparameter to balance the simplicity and flexibility of the RNN-SM. The proposed parser proves to be an effective solution in facilitating smooth communication between multiple devices and also has the added benefit of filtering out noise. The RNN-SM's robust keyword extraction capability holds up even in noisy environments, making it a reliable solution for the compatibility challenges posed by the IoT. [ABSTRACT FROM AUTHOR]

The in-vehicle voltage-based intrusion detection system (VIDS) can recognize the identity of the ECUs and detect the physical layer attacks that cannot be detected by the content-based or frequency-based IDS. However, recent research in VIDS has discovered an overlapped voltage attack that can bypass the existing VIDS by generating overlapped voltage signals from two compromised ECUs to distort the fingerprint of the target ECU. The existing solutions need to change the communication protocol or network topology to mitigate the attack, which may involve additional development costs or scheduling mechanisms to coordinate the tasks. In this paper, motivated by not changing the network topology and protocols, we propose an improved VIDS that can efficiently detect the overlapped voltage attack of the in-vehicle CAN network. Before retraining the VIDS classifier model, we add the mechanism for detecting and filtering overlapped signals in the voltage samples by applying the Long Short-Term Memory (LSTM) autoencoder network to preserve the fingerprint characteristics of the benign waveform in the original samples. First, we establish an LSTM autoencoder model with benign voltages collected in a usual scenario and then apply the automatic thresholding approach to obtain the threshold to separate the overlapped and benign voltages. Next, we filter the overlapped voltages and extract the fingerprint features from the filtered voltage samples to predict the classification of the masquerade CAN packet during the attack. Finally, we evaluate the performance and attack success rate of the proposed VIDS on a CAN bus testbench. The results show that the proposed VIDS can effectively detect the overlapped voltage attack and identify the compromised ECU mimicking the distorted voltage fingerprints with an accuracy of 99.4%. The attack success rate of the proposed VIDS drops to 0 ∼ 18%, which is about 60 ∼ 95% for the existing VIDS. [Display omitted] • We propose an improved in-vehicle VIDS to mitigate the overlapped voltage attack. • We present an LSTM-AE-based examination mechanism to protect VIDS from poisoning. • We evaluate VIDS and prove the effectiveness of overlapped voltage attack detection. [ABSTRACT FROM AUTHOR]

We consider networks where each node represents a server with a queue. An active node deactivates at unit rate. An inactive node activates at a rate that depends on its queue length, provided none of its neighbors is active. For complete bipartite networks, in the limit as the queues become large, we compute the average transition time between the two states where one half of the network is active and the other half is inactive. We show that the law of the transition time divided by its mean exhibits a trichotomy, depending on the activation rate functions. [ABSTRACT FROM AUTHOR]

In this paper, the distributed set-membership filtering problem is investigated for general nonlinear systems subject to Round-Robin and stochastic communication protocols over sensor networks. The considered disturbances are assumed to be unknown but bounded within certain known ellipsoidal regions. Two types of frequently used protocols, i.e., the Round-Robin and stochastic communication protocols are adopted separately to regulate the data transmission among sensor nodes. According to the Round-Robin protocol, each node is able to receive information from only one of its neighboring nodes in a circular order at each time step, whereas the stochastic communication protocol allows each node randomly receive the information sent from one of the neighboring nodes. By resorting to the recursive linear matrix inequalities approach, sufficient conditions are established for the existence of the desired distributed filter, guaranteeing that the state estimates are constrained within certain pre-determined ellipsoidal regions at each time step. Then two optimization problems aiming to minimize the ellipsoids (in the sense of matrix trace) are put forward to seek the locally optimal filtering performance. Finally, simulation examples are given to illustrate the effectiveness of the proposed algorithms. [ABSTRACT FROM AUTHOR]

Contrary to many previous studies on population protocols using the uniformly random scheduler, we consider a more general non-uniform case. Here, pair-wise interactions between agents (moving and communicating devices) are assumed to be drawn non-uniformly at random. While such a scheduler is known to be relevant for modeling many practical networks, it is also known to make the formal analysis more difficult. This study concerns data collection , a fundamental problem in mobile sensor networks (one of the target networks of population protocols). In this problem, pieces of information given to the agents (e.g., sensor readings) should be eventually delivered to a predefined sink node without loss or duplication. Following an idea of the known deterministic protocol TTF solving this problem, we propose an adapted version of it and perform a complete formal analysis of execution times in expectation and with high probability (w.h.p.). We further investigate the important issue of energy consumption. The goal is to improve TTF in terms of energy complexity, while still keeping good time complexities (in expectation and w.h.p.). Namely, we propose a new parameterized protocol for data collection, called lazy TTF, and present a study showing that an appropriate choice of the protocol parameters can considerably improve energy performances (compared to TTF), at a slight expense of time performance. [ABSTRACT FROM AUTHOR]

• The performance of SCLEACH, SCPEGASIS, SCTEEN is analyzed. • Single report is enough to transfer to the sink, to avoid redundant reports. • Proposed protocols have been compared with k-d tree algorithm. • Five parameters are considered for the analysis. SCHRP model takes less time to measure the parameters of the network. In Wireless Sensor Networks (WSNs), the most significant task is to gather the data from the sensor nodes available in specific region available in event sensing field. The nodes in WSNs are energy constrained. To enhance the lifetime of WSNs, energy efficient protocols are needed. Spatial Correlation based Low Energy Adaptive Clustering Hierarchy (SCLEACH), Spatial Correlation based Power-efficient Gathering in Sensor Information Systems (SCPEGASIS), Spatial Correlation based Threshold Sensitive Energy Efficient Sensor Network Protocol (SCTEEN) are well-designed solutions to rectify this problem. These protocols minimize the overall dissipation by means of individual sensor nodes located in the network. Spatial correlation based Hierarchical Routing Protocols (SCHRP) adapt clustering concept and enhance the energy efficiency and the performance of over all network. The Performance of SCHRP model is compared with existing LEACH and PEGASIS, TEEN protocols and results have been taken for various parameters such as End-to-End delay, Packet drop, Packet delivery ratio, Throughput, Energy Efficiency and Energy Consumption. The proposed SCLEACH has 6.35% higher energy efficiency than the existing LEACH protocol. The impact of the proposed protocols are evaluated using various parameters and compared with k-d tree algorithm. The importance of spatial correlation based routing concept is analyzed with respect to k-d tree algorithm and the simulation results have been taken using Network Simulator tool. [ABSTRACT FROM AUTHOR]

Aims: The aim of this study was to examine the impact of vigorous intensity, high dose exercise (DEI) on cannabis use among stimulant users compared to a health education intervention (HEI) using data from the Stimulant Reduction Intervention using Dosed Exercise, National Institute of Drug Abuse National Drug Treatment Clinical Trials Network Protocol Number 0037 (STRIDE).Methods: Adults (N = 302) enrolled in the STRIDE randomized clinical trial were randomized to either the DEI or the HEI. Interventions included supervised sessions three times a week during the Acute phase (12 weeks) and once a week during the Follow-up phase (6 months). Cannabis use was measured at each assessment via Timeline Follow Back and urine drug screens. Cannabis use was compared between the groups during the Acute and Follow-up phases using both the intent-to-treat sample and a complier average causal effects (CACE) analysis.Findings: Approximately 43% of the sample reported cannabis use at baseline. The difference in cannabis use between the DEI and HEI groups during the Acute phase was not significant. During the Follow-up phase, the days of cannabis use was significantly lower among those in the DEI group (1.20 days) compared to the HEI group (2.15 days; p = 0.04).Conclusions: For those who adhered to the exercise intervention, vigorous intensity, high dose exercise resulted in less cannabis use. Results suggest that there were no significant short-term differences in cannabis use between the groups. Further study on the long-term impact of exercise as a treatment to reduce cannabis use should be considered. [ABSTRACT FROM AUTHOR]

Underwater acoustic sensor network (UASN) effectively improves the reliability of underwater long distance transmission through multi-hop transmission between multiple nodes. However, the limited energy of underwater acoustic nodes and large end-to-end transmission delay lead to uneven load and short lifetime of UASN. In this paper, we propose a dynamic layered routing protocol based on back propagation neural network (BP-NN), named as BPDLR, to address the above issues. In the proposed scheme, considering such factors as node topology, residual energy and communication environments, the UASN is vertically divided into the top layer, the middle layer and the bottom layer. The routing designs in each layer are different, and each of them is predicted by BP-NN training model for routing. In addition, we compare the proposed BPDLR protocol with the existing schemes such as static layered routing (SLR) protocol and depth-based routing (DBR) protocol in terms of network node survival, average end-to-end delay and packet loss rate. The simulation results show that, the proposed BPDLR protocol effectively alleviates the energy hole problem of UASN and extends the network lifetime. [ABSTRACT FROM AUTHOR]

• There is no collaborative multihop LoRa protocol. Users 'nodes cannot relay each-other's messages. • MauMe assumes users have a home-node with permanent power supply (base-node) acting as a relay for all users. • MauMe is single channel and designed for a controlled flooding of messages. • Messages are acknowledged. Acknowledgments kill lost messages. • Users can activate local Wi-Fi connection to allow sending free emergency SMS using a smartphone. • MauMe has a ready-to-use Github C++ library which allows immediate deployment on ESP32 microcontrollers. • The proposed implementation respects the legal duty-cycle. Low-cost low-power long-distance LoRa radio devices recently made available on the market allow the emerging of a new generation of networking paradigms on the Internet of Things. While the LoRaWan offers an efficient way of connecting LoRa end-point devices to the internet, LoRaWan nodes do not act as peers, but rather as terminals connected to gateways. As such, the current state of the art does not offer a public protocol for easily taking advantage of the fact that individuals and professionals wishing to aggregate data using LoRa devices are likely to run each a "base-node" on a continuous basis. Such permanently-powered base-nodes could potentially offer an increased cumulated area coverage to other nodes if they would behave as relays. In the present study, an Epidemic Delay Tolerant Network messaging protocol is proposed, which allows multi-hops between peer LoRa relay-nodes through a raw-LoRa controlled-flooding approach. This protocol has been implemented on low-cost LoRa-chip-equipped microcontrollers in the form of an open-source library acting as a network transport-layer. The design analysis concluded that MauMe is better suited for networks with reduced connectivity (≤ 9), and that a 4-connectivity redundant network could allow each user to send several tens of messages several tens of hops away. The proposed approach was tested on three different LoRa network topologies, and the totality of the packets and acknowledgments reached their destination. Furthermore, the network's activity ceased after delivery, confirming the ability of the protocol to return the network to rest after the flooding. The proposed library also offers to users a free emergency-messaging system implemented as an http server embedded in each node and accessible via Wi-fi. End-users can readily use our solution to easily deploy a network of sensors at a much lower cost than when using multiple gateways. The MauMe protocol is a first step towards the creation of collaborative and application-friendly extended-range LoRa-peers networks, and is intended for use in remote regions with scattered housings such as in the islands and atolls of Polynesia. [ABSTRACT FROM AUTHOR]

With the development of the Internet of Things, multi-access edge computing (MEC) is widely used in industrial IoT, intelligent transport systems, and IoT data management. As a decentralized, tamper-proof, multiparty trusted ledger technology, blockchain can enhance MEC security, privacy, and automatic use of resources. However, highly redundant storage and complex consensus prevent the blockchain from being directly deployed to edge computing nodes with limited resources. Unlike existing lightweight schemes, which do not consider liberating transaction data from blocks, this paper proposes a lightweight blockchain ledger protocol for MEC networks. The novelty of this work is that the transaction data in the block is compressed into a succinct proof through the zero-knowledge proof algorithm. To reduce the storage of block data, this paper proposes the proof-of-state-transfer model in which nodes verify the correctness of the global state transfer in the block without transactions. To reduce the communication complexity of consensus, this paper proposes a lightweight consensus protocol, which reduces the communication complexity of block voting and view switching to O (n). This paper develops the prototype system of TinyLedger to experiment and evaluate the performance of the system in terms of storage, verification, throughput, and communication. Experimental results show that compared to Ethereum, TinyLedger reduces storage capacity by 98.16%, communication volume by 74.53%, and block verification time by 87%. [ABSTRACT FROM AUTHOR]

The use of collaborative applications in which several individuals interact to solve a problem is an important strategy both in educational settings as well as professional environments. Virtual Reality (VR) technology, in particular, has acquired a predominant role in many industries. However, as the level of immersion and realism of the VR experience increases, so does the demand for computational resources, as rendering processes become increasingly intensive and can negatively affect other communication processes that are critical in collaborative environments. In this paper, we present a software framework based on multi-agent systems that enables the separation of rendering processes from internal data management tasks and communication processes between users, which are prevalent in collaborative virtual reality applications. The results of our validation studies show that, compared to other techniques based on protocol or network enhancements, the proposed architecture can significantly improve collaborative processes in general, and virtual reality-based applications in particular. • A multi-agent paradigm is proposed for the development of collaborative VR-based applications. • The multi-agent architecture enables separating data management and communication tasks from rendering tasks. • The proposed paradigm demonstrates significant improvements in terms of computational cost in collaborative applications. • The use of an agent-based architecture enables the scalability of the platform. [ABSTRACT FROM AUTHOR]

Real-time simulation is crucial in time-critical situations within the environmental modeling domain. The advancement of web technologies has facilitated the sharing and integration of various resources over the Internet. Web-based real-time modeling has gained increasing attention. However, interoperability remains a challenge when integrating environmental models and real-time observations in a web environment. This paper proposes an interoperable and service-oriented approach for real-time modeling by coupling the Open Geospatial Consortium (OGC) Web Processing Service (WPS) and SensorThings Application Programming Interface (API). The SensorThings API provides a unified way to interconnect environmental sensors, data, and applications. The OGC WPS defines standard operations for accessing online processes. We extended OGC WPS to support the Message Queuing Telemetry Transport (MQTT) protocol and integrated it with SensorThings API. This integration enables real-time access to sensor observations and time-series simulation results. A prototype system using the Storm Water Management Model (SWMM) demonstrates the applicability and effectiveness of our approach. • We proposed an interoperable and web-based approach for integrating IoT real-time observations into environmental models. • OGC WPS and SensorThings API work collaboratively for environmental modeling using the MQTT protocol. • Key issues, including network protocol, data exchange, and execution workflow, are considered to improve interoperability. [ABSTRACT FROM AUTHOR]

Abstract Routing in Wireless Sensor Networks (WSNs) is the most significant and the challenging issue for the researchers in terms of enhancing its performance in terms of network lifetime, energy efficiency, scalability, connectivity, throughput, etc. They have the incredible capability to interact and gather data from any physical environment with help of routing protocols. Many routing protocols based solutions have been proposed in the recent years for accomplishing the preferred level of performance in WSNs for these issues. The hierarchical heterogeneous cluster based energy efficient routing protocols are more efficient as compared to flat and location based routing protocols due to the presence of nodes heterogeneity in terms of energy level of sensor nodes which enhances the lifetime of the network. The most recent trend that extensively enhances the functionality and the performance of WSNs is the use of mobile sensor nodes. In this paper, the authors proposed a novel concept regarding mobile sensor nodes is proposed called Mobile Energy Aware Cluster Based Multi-hop (MEACBM) routing protocol for hierarchical heterogeneous WSNs which selects CHs on the basis of newly proposed probability equation which selects only that sensor node as Cluster Head (CH) which has the highest energy among other sensor nodes by introducing a new term S(i).E in the equation. It considers hierarchical heterogeneous clustering considering three levels of sensor nodes; multi-hoping for inter-cluster communication and connectivity of sensor nodes within the whole network area. In MEACBM, after the deployment of sensor nodes and formation of clusters, the whole network area is divided into sectors and inside each sector a mobile sensor node is placed which act as Mobile Data Collector (MDC) for collecting data from CHs. This technique helps in significantly reducing the energy consumption of sensor nodes for transferring information to the Base Station (BS). Simulation performance based results indicates the effectiveness of MEACBM routing protocols by comparing it with other contemporary cluster based routing protocols in terms of network lifetime, stability, throughput, number of CHs and number of dead nodes. [ABSTRACT FROM AUTHOR]

Abstract We introduce the estimation protocol for detecting the temperature of the transverse vibrational modes of linear ion crystal. We show that thanks to the laser induced laser coupling between the vibrational modes and the collective spin states the estimation of the temperature is carried out by set of measurements of the spin populations. We show that temperature estimation protocol using single ion as a quantum probe is optimal in a sense that the set of state projective measurements saturate the fundamental Cramer–Rao bound. We find a plateau of the maximal temperature sensitivity using ion chain as a quantum probe. Moreover, we show that the non-classical part of the quantum Fisher information could leads to enhancement of the temperature sensitivity compared to the single ion case. Highlights • Estimation of the temperature of the transverse vibrational modes of linear ion crystal. • The methods rely on using spin–phonon coupling in a system of trapped ions. • The estimation precision is quantified in terms of quantum Fisher Information. [ABSTRACT FROM AUTHOR]

Abstract Boosted by trends such as Industrial IoT and Industry 4.0, industrial Ethernet networks (EtherNet/IP, EtherCAT and PROFINET IRT as top-3 players) have been commonly deployed in industrial automation. The aim of this paper is to provide a practical guideline for selecting the right protocol in industrial networked control systems (NCSs) by comparing the performance of these protocols. Communication delays are discussed, formulated and evaluated with a study of a typical NCS. Simulation results demonstrate that with different frame packing, media access scheme, etc., EtherNet/IP, EtherCAT and PROFINET IRT offer different levels of real-time capabilities which lead to different control performance. Highlights • EtherCAT, PROFINET IRT and EtherNet/IP offers various real-time capabilities. • A generic process is established to evaluate communication and control performance. • A guideline to choose the right protocol for a networked control system is provided. [ABSTRACT FROM AUTHOR]

Abstract Previous task mapping assumes that applications directly fetch data on remote nodes and build up their energy efficient mapping based on pattern of the NoC traffic. However, the data movement is actually managed by a cache coherence mechanism that executes a much more complicated protocol under application layer to guarantee data correction. Thus, we propose an energy efficient task mapping referring the protocol layer, rather than application layer, to precisely model protocol activities and energy dissipation. By a probabilistic description of cache accessing, we find a efficient method to convert application activities to energy consumption, generating an energy evaluation as a global optimization goal. We also propose a task mapping algorithm to minimize the energy consumption by referring activity intensity of the protocol. The experimental results show that the proposed energy model achieves a precision with less than 2% error and provides a credible quantitative criterion for energy optimization of cache coherence protocols. Comparing to application-layer optimization, our task mapping can obtain 20% energy saving and 15% latency reduction on average. [ABSTRACT FROM AUTHOR]

Abstract In this paper, we investigate the finite-time consensus control problem for heterogeneous nonlinear multi-agent systems (MASs) subject to nonlinear uncertainties. In the case of a connected and undirected communication graph, a new finite-time consensus control algorithm for leaderless MASs is presented. The designed consensus protocol can guarantee that the steady state error of every two agents converge to zero in a finite-time. Compared with some existing studies, in which the upper bounds of uncertainties are assumed to be some positive constants, the upper bound assumption conditions of uncertainties are relaxed to be some positive functions. Finally, a numerical example and a practical model are presented to demonstrate the effectiveness of the proposed consensus control method. [ABSTRACT FROM AUTHOR]

Abstract Mobile Wireless Sensor Network (MWSN) is a set of interconnected mobile sensor devices forming a dynamic network without a fixed administration. MWSN is used in various domains, such as disaster detection, medical systems, military applications, vehicular communications, and in other sensitive applications. Compared to the classical sensor networks, MWSNs involve an additional constraint consisting of the topology change frequency caused by the mobility of sensor devices. This influences highly the energy consumption and consequently the network reliability. In this paper, we take in charge this important issue and we contribute by the proposition of an efficient and energy-aware routing protocol. The proposed protocol operates for both request and event oriented MWSN applications. It introduces the sensor device mobility history in order to build-up stable routing paths, and incorporates a novel technique of dissimulation in order to exchange the mobility control messages without overhead. We have evaluated the performances of the proposed protocol through simulations, in which it provides effective results in terms of energy consumption and load-balancing. [ABSTRACT FROM AUTHOR]

Abstract This paper describes the overlay protocol Chord using the formalism of Abstract State Machines. The formalization concerns Chord actions that maintain ring topology and manipulate distributed keys. We define a minimal set of deterministic constraints and prove that they guarantee the stability of the topological structure of the network and the consistency of data handling. [ABSTRACT FROM AUTHOR]

Abstract Bit commitment is an important tool in the design of many secure cryptographic protocols, such as coin flipping, zero-knowledge proof, and secure computation. In this paper, we present a computationally light-weight bit commitment protocol over a noisy channel. For the security of the proposed protocol, we show that the receiver has almost no information about the committer's secret due to unpredictability of the noises in the communication channel. Hence, the security of our bit commitment protocol does not depend on hard problems; it is information-theoretically secure. Furthermore, the protocol needs only exclusive-or operations. Thus, it is computationally light-weight, and it can be used in the devices whose computing resources are limited. [ABSTRACT FROM AUTHOR]

Highlights • This study investigates what and how source information is attended to and utilized in the SCWT. • The findings indicated that the SCWT required knowledge-transforming process. • Test-takers could rely on the conceptual information for story interpretation and story development. • Test-takers could directly employ or imitate the noticed textual information in the continued part. • Teachers' perceptions of source use in the SCWT were also examined. Abstract The story continuation writing task (SCWT) is a newly developed type of integrated writing task that is observed to be able to stimulate language learning efficiently. Nevertheless, little is known with respect to what source knowledge test-takers notice and how they process the noticed information during the task. This paper contributes to the literature by investigating what and how source information is attended to and utilized in SCWT. Think-aloud protocols and retrospective interviews were collected from 19 students. In addition, nine teachers were interviewed for their perceptions about source use in SCWT. Findings indicated that the SCWT required knowledge-transforming process, as the test-takers attended to both conceptual and textual aspects of the source text. The SCWT represented a unique integrated writing task, because test-takers could rely on the conceptual information for source interpretation and writing development. They could directly employ or imitate the noticed textual information in the continuation. The implications of adopting SCWT as an integrated writing task for assessing students are discussed. [ABSTRACT FROM AUTHOR]

Abstract This paper investigates the consensus problem of multi-agent systems (MASs) described by linear dynamic models. In order to avoid using the global information and reduce communication burden, the distributed adaptive event-based control approach is presented. Some novel triggering functions and control protocols are designed. The obtained results show that consensus can be achieved only with local information and communicating with neighbors continually is avoided as well. In addition, the Zeno-behavior for the concerned closed-loop system is excluded. Finally, a numerical example is provided to validate the availability of the obtained theoretical results. [ABSTRACT FROM AUTHOR]

Abstract The Threshold-based Low-energy Adaptive Clustering Hierarchy (T-LEACH) protocol declares that cluster heads do not have to turn over every round but rather every batch of rounds. In other words, nodes keep serving as cluster heads as long as their energy is higher than a threshold energy. This article imposes upon major drawbacks of T-LEACH protocol and presents a Modified Threshold-based Cluster Head Replacement (MT-CHR) protocol. In the MT-CHR protocol, a new probability of being a cluster head, for any node in any round, has been proposed which agrees fairly with the assumptions introduced in LEACH protocol. Moreover, a new expression for threshold energy is proposed in which delaying the first node death and avoiding any data loss are taken into consideration. The performance of MT-CHR is evaluated using alive nodes, network lifetime, as well as network utilization performance metrics. The results are further compared with those obtained importantly from LEACH and T-LEACH protocols and the contributions of MT-CHR protocol are extremely impressive. As far as the real sensor network is concerned, the MT-CHR protocol is highly applicable and very effective as long-lasting networks are ascertained. [ABSTRACT FROM AUTHOR]

Abstract In the classic cake-cutting problem (Steinhaus, 1948), a heterogeneous resource has to be divided among n agents with different valuations in a proportional way —giving each agent a piece with a value of at least 1 ∕ n of the total. In many applications, such as dividing a land-estate or a time-interval, it is also important that the pieces are connected. We propose two additional requirements: resource-monotonicity (RM) and population-monotonicity (PM). When either the cake or the set of agents grows or shrinks and the cake is re-divided using the same rule, the utility of all remaining agents must change in the same direction. Classic cake-cutting protocols are neither RM nor PM. Moreover, we prove that no Pareto-optimal proportional division rule can be either RM or PM. Motivated by this negative result, we search for division rules that are weakly-Pareto-optimal — no other division is strictly better for all agents. We present two such rules. The relative-equitable rule, which assigns the maximum possible relative value equal for all agents, is proportional and PM. The so-called rightmost mark rule, which is an improved version of the Cut and Choose protocol, is proportional and RM for two agents. [ABSTRACT FROM AUTHOR]

One popular approach employed to tackle classification problems in a static environment consists in using a Dynamic Classifier Selection (DCS)-based method to select a custom classifier/ensemble for each test instance according to its neighborhood in a validation set, where the selection can be considered region-dependent. This idea can be extended to concept drift scenarios, where the distribution or the a posteriori probabilities may change over time. Nevertheless, in these scenarios, the classifier selection becomes not only region but also time-dependent. By adding a time dependency, in this work, we hypothesize that any DCS-based approach can be used to handle concept drift problems. Since some regions may not be affected by a concept drift, we introduce the idea of concept diversity, which shows that a pool containing classifiers trained under different concepts may be beneficial when dealing with concept drift problems through a DCS approach. The impacts of pruning mechanisms are discussed and seven well-known DCS methods are evaluated in the proposed framework, using a robust experimental protocol based on 12 common concept drift problems with different properties, and the PKLot dataset considering an experimental protocol specially designed in this work to test concept drift methods. The experimental results have shown that the DCS approach comes out ahead in terms of stability, i.e., it performs well in most cases requiring almost no parameter tuning. [ABSTRACT FROM AUTHOR]

Wireless body area networks (WBANs) are receiving significant interest as the next generation of wireless networks and emerging technology in the field of health monitoring. One of the most important factors for the acceptance of WBANs is the provision of appropriate security and access control mechanisms. Due to its nature in transferring the patients' sensitive data, WBAN has both classical and specific security requirements. In this paper, we survey such requirements and propose a new security scheme for satisfying them in WBANs. The proposed scheme deals with the overall network architecture, including intra- and inter-WBAN tiers, and proposes two mutual authentication and key exchange protocols for diverse WBAN environments. In our scheme, we use biometrics as one part of the solution for authentication and key exchange, and the simple password three-party key exchange protocol as the other part of the WBAN security. Our scheme meets security requirements along with energy-constraint considerations. We verify our scheme through BAN Logic. Unlike the majority of the existing security protocols, our scheme proposes a solution for entire WBANs communications, from biosensors to the medical server as a trusted third party. [ABSTRACT FROM AUTHOR]

The paper discusses second-order consensus problem of nonlinear multi-agent systems with time delay and intermittent communications. Basing on local intermittent information among the agents, an effective control protocol is proposed by node-based distributed adaptive intermittent information, which a time-varying coupling weight to each node in the communication, some novel criteria are derived in matrix inequalities form by resorting to the generalized Halanay inequality. It is proved that second-order consensus can be reached if the measure of communication is larger than a threshold value under the strongly connected and balanced topology. Moreover, consensus problem is also considered for second-order non-delayed nonlinear multi-agent systems. Finally, a simulation example is presented to illustrate the theoretical results. [ABSTRACT FROM AUTHOR]