Synchronous Node Research Articles

Development of Synchronization Selection Method in IoT with Secure Channel Bidirectional Communication

Background: The rapid development of wireless communications and mobile computation has given rise to the novel Internet of Things (IoT) systems, which is causing considerable research attention and industrial development. However, the lack of synchronization between the timers of IoT devices compromises the network's security. Aim: The purpose of this patent application is to present a technique for synchronizing the timepieces of IoT gadgets and establishing a secure channel for the transmission of data from source to destination. Objective: This study proposes a Synchronization Selection Method (SSM) for IoT systems to enhance network security and reduce packet loss. Methods: The method utilizes time-lay synchronization and RSA algorithm-based secure channel establishment. Time lay is a technique that was developed for IoT devices to achieve efficient clock synchronization of sensor nodes. Before synchronizing the sensor nodes' timings, the cluster leaders initiate the process. Utilizing a finite number of nodes, the proposed method was executed in MATLAB. Results: Time-lay synchronization involves all network nodes synchronizing their clocks with a third-party clock. In the context of time-lay synchronization, the term “third-party clock” refers to a single specific point that contains the time signal that all nodes in the network use as a reference. This third-party clock is outside of the network nodes and acts as the standard for the precise and synchronized time within the network. Therefore, it can be deduced that each of the techniques possesses its advantages and disadvantages. Each of the synchronization techniques has the potential to significantly benefit the IoT by offering smart clock synchronization that is more secure. Experimental results demonstrate that the proposed method improves throughput and reduces packet loss compared to existing techniques. Conclusion: The potential of this patent is highly significant for solving the synchronization problem of IoT devices and enhancing network security with decreased network packet loss. Other: The SSM would be assessed using the parameters of packet loss and throughput.

Enhancing cybersecurity in Edge IIoT networks: An asynchronous federated learning approach with a deep hybrid detection model

In the rapidly evolving field of the Industrial Internet of Things (IIoT), advancements in wireless technology have resulted in significant cybersecurity vulnerabilities. These weaknesses pose serious risks such as damage to manufacturing systems, theft of intellectual property, and substantial financial losses. This study introduces an advanced deep hybrid learning model in an asynchronous federated learning setup, aimed at improving the detection of cyberattacks and ensuring robust data privacy. The combination of Convolutional Neural Networks (CNN), Gated Recurrent Units (GRU), and Long Short-Term Memory (LSTM) networks provides an effective solution for quickly identifying anomalies in IIoT sensor traffic. Our model operates asynchronously, ensuring data remains localised to improve security while avoiding the need for complete node synchronisation. Demonstrating outstanding effectiveness, the model achieves an accuracy of 1.00%, precision of 1.00%, recall of 1.00%, and an F1 score of 1.00% across a variety of IIoT environments. These results highlight the model’s exceptional adaptability and its capability to rapidly respond to emergent threats, marking a significant step forward in the protection of IIoT infrastructures and the rigorous maintenance of data privacy.

Integrative multi-region molecular profiling of primary prostate cancer in men with synchronous lymph node metastasis

Localized prostate cancer is frequently composed of multiple spatially distinct tumors with significant inter- and intra-tumoral molecular heterogeneity. This genomic diversity gives rise to many competing clones that may drive the biological trajectory of the disease. Previous large-scale sequencing efforts have focused on the evolutionary process in metastatic prostate cancer, revealing a potential clonal progression to castration resistance. However, the clonal origin of synchronous lymph node (LN) metastases in primary disease is still unknown. Here, we perform multi-region, targeted next generation sequencing and construct phylogenetic trees in men with prostate cancer with synchronous LN metastasis to better define the pathologic and molecular features of primary disease most likely to spread to the LNs. Collectively, we demonstrate that a combination of histopathologic and molecular factors, including tumor grade, presence of extra-prostatic extension, cellular morphology, and oncogenic genomic alterations are associated with synchronous LN metastasis.

TERT RNAscope analysis of sub-centimetric papillary thyroid carcinomas and synchronous lymph node metastases.

Sub-centrimetric papillary thyroid carcinomas usually have a good prognosis with a cancer specific survival of > 99%, however in up to 65% of patients, lymph node metastases can be observed. Molecular alterations in BRAF, TERT and TP53 are associated with worse clinicopathological outcome in patients with papillary thyroid carcinoma. Twenty-two cases of papillary thyroid carcinomas measuring ≤ 1cm with synchronous lymph node metastases were examined regarding morphological patterns and immunohistochemical status of p53, Ki-67, and BRAF V600E status. TERT RNA expression in lymph node metastases were evaluated by RNAScope®. Morphological patterns were heterogeneous in both primary tumors and lymph node metastases. Proliferation indices measured by Ki-67 were low. Both primary and lymph node metastases were wild type for p53 by immunohistochemical analysis. No lymph node metastasis showed TERT expression by RNAScope®. Our data indicate that TERT expression is not involved in the development early lymph node metastasis in patients with sub-centimetric PTC.

Potential imaging targets in primary head and neck squamous cell carcinoma and lymph node metastases

PurposeTo investigate glycoprotein nonmetastatic melanoma protein B (GPNMB) and vascular endothelial growth factor (VEGF) as potential fluorescent imaging markers by comparing their protein expression to epidermal growth factor receptor (EGFR). Materials and methodsThirty-eight paired samples of untreated head and neck squamous cell carcinoma (HNSCC) primary tumours (PT) and corresponding synchronous lymph node metastases (LNM) were selected. After immunohistochemical staining, expression was assessed and compared by the percentage of positive tumour cells. Data were analysed using the Mann-Whitney test, effect sizes (ESr) and Spearman's correlation coefficient (r). ResultsGPNMB expression was observed in 100 % of PT, and median 80 % (range 5–100 %) of tumour cells, VEGF in 92 % and 60 % (0–100 %), EGFR in 87 % and 60 % (0–100 %) respectively. In corresponding LNM, GPNMB expression was observed in 100 % of LNM and median 90 % (20–100 %) of tumour cells, VEGF in 87 % and 65 % (0–100 %), and EGFR in 84 % and 35 % (0–100 %). A positive correlation was found between expression in PT and LNM for GPNMB (r = 0.548) and EGFR (r = 0.618) (p < 0.001), but not for VEGF (r = −0.020; p = 0.905). GPNMB expression was present in a higher percentage of tumour cells compared to EGFR in PT (p = 0.015, ESr = −0.320) and in LNM (p < 0.001, ESr = −0.478), while VEGF was not (p = 1.00, ESr = −0.109 and − 0.152, respectively). ConclusionGPNMB expression is higher than EGFR in untreated HNSCC PT and corresponding LNM, while VEGF expression is comparable to EGFR. GPNMB is a promising target for fluorescent imaging in HNSCC.

Analysis of End-to-End Delay in the Transport Segment of Fronthaul 4G/5G Networks Based on TSN Technology

One of the characteristic features of 4G/5G mobile networks is the spatial separation of functional blocks. The corresponding segments of the xHaul transport network are used to connect these blocks. One of them is the Fronthaul front end segment, which connects remote radio equipment with their control equipment. The data streams of standard CPRI/eCPRI radio interfaces in this segment impose strict requirements on the quality of service and, above all, on delays. To meet these requirements, it was proposed to use in the Fronthaul segment Ethernet bridge network based on the technology of time-sensitive networks TSN (Time Sensitive Networking), which provides determinated delays, reliable packet delivery and high accuracy of synchronization of nodes in the network. The IEEE 802.1CM standard describes profiles of TSN networks that defines the functions, options, configurations, default values, protocols and procedures of bridges, stations and local networks required to build the Fronthaul transport segment. The article presents a methodology for determining the maximum end-to-end traffic delays of standard CPRI/eCPRI radio interfaces in the Fronthaul segment of 4G/5G networks, built on the basis of TSN technology, in accordance with the requirements of IEEE 802.1CM standard. Two main components of end-to-end delay are identified ‒ delays in TSN bridges and delays in xEthernet channels. For high-priority traffic flows of CPRI/eCPRI radio interfaces in bridges, characteristic cases of mutual influence of flows arriving simultaneously at different input ports are given. An example of numerical calculation is given, which allowed to determine the permissible physical length of the Fronthaul segment at a given boundary end-to-end delay of transmission of high-priority traffic.

Cluster shift keying: covert transmission of information via cluster synchronization in chaotic networks

A network of chaotic systems can be designed in such a way that the cluster patterns formed by synchronous nodes can be controlled through the coupling parameters. We present a novel approach to exploiting such a network for covert communication, where controlled clusters encode symbols spatio-temporally. The cluster synchronization network is divided into two subnetworks: transmitter and receiver. First, we specifically design the network with controlled parameters in the transmitter. Second, we ensure that the nodes of the links connecting the transmitter and receiver are not in the same clusters for all the control parameters. The former condition ensures that the control parameters changed at the transmitter change the whole clustering scheme. The second condition enforces that the transmitted signals are always continuous and chaotic. Hence, the transmitted signals are not modulated by the information directly but distributed over the links connecting the subnetworks. Without knowing the network topology, the information cannot be deciphered by eavesdropping on the channel links. The performance has been assessed by extensive simulations of bit error rates under noisy channel conditions.

Pinning Synchronization for Stochastic Complex Networks With Randomly Occurring Nonlinearities: Tackling Bit Rate Constraints and Allocations.

In this article, the ultimately bounded synchronization problem is investigated for a class of discrete-time stochastic complex networks under the pinning control strategy. Communication between system nodes and the remote controller is facilitated via wireless networks subject to bit rate constraints. The system model is distinguished by the inclusion of randomly occurring nonlinearities. A coding-decoding transmission mechanism under constrained bit rates is introduced to characterize the digital transmission process. To achieve synchronization of the network nodes with the unforced target node, a pinning controller is specifically devised based on the information from partially selected nodes. Through the application of the stochastic analysis method, a sufficient condition is derived for ensuring the mean-square boundedness of the synchronization error system. In addition, an optimization algorithm is introduced to address bit rate allocation and the design of desired controller gains. Within the presented theoretical framework, the correlation between the mean-square synchronization performance and bit rate allocation is further elucidated. To conclude, a simulation example is provided to substantiate the efficacy of the recommended pinning control approach.

Reconstruction of simplex structures based on phase synchronization dynamics

High-order interactions as exemplified by simplex and hyper-edge structures have emerged as a prominent area of interest in complex network research. These high-order interactions introduce much complexity into the interplay between nodes, which often require advanced analytical approaches to fully characterize the underlying network structures. For example, methods based on statistical dependencies have been proposed to identify high-order structures from multi-variate time series. In this work, we reconstruct the simplex structures of a network based on synchronization dynamics between network nodes. More specifically, we construct a topological structure of network by examining the temporal synchronization of phase time series data derived from the Kuramoto-Sakaguchi (KS) model. In addition, we show that there is an analytical relationship between the Laplacian matrix of the network and phase variables of the linearized KS model. Our method identifies structural symmetric nodes within a network, which therefore builds a correlation between node synchronization behavior and network’s symmetry. This representation allows for identifying high-order network structure, showing its advantages over statistical methods. In addition, remote synchronization is a complex dynamical process, where spatially separated nodes within a network can synchronize their states despite the lack of direct interaction. Furthermore, through numerical simulations, we observe the strong correlation between remote synchronization among indirectly interacting nodes and the network’s underlying symmetry. This finding reveals the intricate relationship between network structure and the dynamical process. In summary, we propose a powerful tool for analyzing complex networks, in particular uncovering the interplay between network structure and dynamics. We provide novel insights for further exploring and understanding the high-order interactions and the underlying symmetry of complex networks.

Double tracking control for the complex dynamic network with an unavailable link state

This research investigates the double tracking control problem for the complex dynamic network (CDN) with an unavailable link state. Firstly, from the angle of a large-scale system, the dynamical model of CDN is described by the vector differential equations, which consists of node dynamic subsystem (NDS) and link dynamic subsystem (LDS), in which the weighted-values of links are regarded as the state variables of LDS. Secondly, to realise the double tracking control (DT-Control) of CDN, the presented DT-Control scheme in this paper includes the synthesis of controller for NDS and the coupling term in LDS, which can ensure that the two subsystems track the given reference targets. The tracking of NDS contains the synchronisation of nodes as the special case, and the tracking of LDS shows that the eventual topologic structure of CDN will be determined only by the given link reference signal. Due to the economic and technological limitations of sensors in the practice applications, this paper assumes that the state variables of LDS are unavailable in the DT-Control scheme. Finally, the engineering simulation example is given to verify the validity of DT-Control scheme proposed in this paper.

Research on Optimization of Node Deployment in Wireless Sensor Networks Driven by Artificial Intelligence

The security deployment of WSN (Wireless Sensor Network) nodes also needs to ensure the performance of node coverage, which affects the accuracy and integrity of information detected by the network and the quality of service of the network. It is not enough to improve the network coverage and network performance of nodes only by adjusting the network topology of WSN, so there will be a problem of excessive node density in the network deployment area, which will lead to node redundancy and coverage hole, which will eventually affect the accuracy and integrity of monitoring information. In this paper, the deployment of WSN nodes driven by AI(Artificial Intelligence) is optimized. The data fusion theory is introduced, and the data fusion model is used to integrate node synchronization task scheduling, dynamic node deployment and dynamic network topology recovery.

Joint time synchronization and localization of underwater mobile node

Joint time synchronization and localization of underwater mobile node

Measurement system for ultraviolet channel modeling and communications.

There has been an increasing interest in ultraviolet (UV) communications as a promising technology for non-line-of-sight (NLOS) networking by exploiting atmospheric scattering at UV wavelengths that enables a unique NLOS UV communication channel. While there has been significant theoretical and simulation-based investigation of the UV channel characteristics, there is limited work in terms of experimental research and validation of the analytical models. In this paper, we present a flexible experimental system for precise UV channel and communications measurements. Specifically, a transceiver system is developed that consists of a gimbal, UV light-emitting-diode array, and photomultiplier tube detector, node synchronization, and LabVIEW-based data acquisition subsystems. Novel techniques to precisely characterize the UV LED array radiation pattern, absolute transmit power, and field of view of the detector are also presented. The utility of the developed system is then demonstrated by performing a variety of experiments including UV channel model validation and steering optimization for UV communication links where the results were in very good agreement with theory and simulation.

In search for new targets: Differences of HER2 receptor expression between CNB and synchronous axillary lymph node metastases in 205 patients.

e12559 Background: Lately large clinical trials have provided new treatment options for patients with metastatic HER2-low breast cancer. Studies have shown that there may be change in the expression of HER2 during disease progression. Yet, it is rarely considered that there can be already differences between primary tumor and synchronous lymph node metastases (LMN) in the primary setting. The aim of the present study was to analyze different HER2 expression profiles between primary tumor and synchronous LNM. Methods: We included 205 patients with primary breast cancer and LNM who underwent oncologic surgery between 2008 and 2021. Formalin-fixed and paraffin-embedded (FFPE) material were routinely examined immunohistochemically according to the ASCO guidelines. Membranous HER2-staining was scored as follows: zero = 0, low = 1+, equivocal = 2+ and positive = 3+. Results: 205 patients were either HER2 low or HER2 zero in CNB. When comparing CNB and LNM 5 (2,4%) patients were HER2 zero in CNB and HER2 low in LNM. 161 (78.5%) patients were HER2 zero in both CNB and LNM. 21 (10.2%) patients had a shift from HER2 low to HER2 zero in LNM. 18 (8,8%) patients had a HER2 low expression in CNB and HER2 zero expression in LNM. Conclusions: There seems to be a high frequency of HER2 heterogeneity between primary tumor and LNM in the primary setting. Different HER2 expression profiles should be considered for an optimal and individual treatment.

Cosmic time calibrator for wireless sensor network

Time synchronization of sensor nodes is critical for optimal operation of wireless sensor networks (WSNs). Since clocks incorporated into each node tend to drift, recurrent corrections are required. Most of these correction schemes involve clients periodically receive RF timing signals from a time server. However, an RF-based scheme is prone to glitches or failure unless operating in a region with almost entirely unobstructed space; hence it only operates well in a limited range of environments. For example, GPS requires open-sky environments. Moreover, the precision of land-based RF schemes is limited to a few micro seconds. In this work, we report on a more versatile and new type of recurrent clock resynchronization scheme called cosmic time calibrator (CTC) and its development and testing. CTC utilizes cosmic-ray muon signals instead of RF signals. Muons are penetrative and continuously precipitating onto the Earth’s surface, and they tend to travel linearly through encountered matter at approximately the speed of light in vacuum. Therefore, muons themselves can periodically transfer the precise timing information from node to node; hence, the performance of the inter-nodal communication device such as Wi-Fi or Bluetooth is minimized/unnecessary for an online/offline WSN analysis. The experimental results have indicated that a resynchronization frequency and precision of 60 Hz and ± 4.3 ns (S.D.) can be achieved. Modelling work of the WSN-based structural health monitoring of aerospace structures has shown that CTC can contribute to the development of new critical and useful applications of WSN in a wider range of environments.

Network Migration Problem: A Hybrid Logic-Based Benders Decomposition Approach

Telecommunication networks frequently face technological advancements and need to upgrade their infrastructure. Adapting legacy networks to the latest technology requires synchronized technicians responsible for migrating the equipment. The goal of the network migration problem is to find an optimal plan for this process. This is a defining step in the customer acquisition of telecommunications service suppliers, and its outcome directly impacts the network owners’ purchasing behavior. We propose the first exact method for the network migration problem, a logic-based Benders decomposition approach that benefits from a hybrid constraint programming–based column generation in its master problem and a constraint programming model in its subproblem. This integrated solution technique is applicable to any integer programming problem with similar structure, most notably the vehicle routing problem with node synchronization constraints. Comprehensive evaluation of our method over instances based on six real networks demonstrates the computational efficiency of the algorithm in obtaining quality solutions. We also show the merit of each incorporated optimization paradigm in achieving this performance. History: Accepted by David Alderson, Area Editor for Network Optimization: Algorithms &amp; Applications. Funding: This work was supported by Mitacs. SciNet is funded by the Canada Foundation for Innovation, the Government of Ontario, Ontario Research Fund–Research Excellence, and the University of Toronto. Supplemental Material: The e-companion is available at https://doi.org/10.1287/ijoc.2023.1280 .

Clonal and “Intrinsic” Heterogeneity of Somatic Variants in Microsatellite-Stable Colorectal Carcinomas and Their Metastases

To test the traditional model of tumor progression, Darwinian-type evolution, against the more recent Big Bang model, we selected 6 microsatellite-stable colorectal standard-type adenocarcinomas and their synchronous lymph node and liver metastases. Somatic genomic variants were identified by whole-exome sequencing (WES) of large tumor fragments from the primaries and 1 liver metastasis each, and used to design targeted resequencing next-generation sequencing (NGS) panels, 1 per case. Targeted deep resequencing (mean coverage, 2725; median, 2222) was performed with DNA from punch samples (1-mm tissue microarrayer needles) obtained from different regions of the primaries and their metastases. In total, 255 genomic variants were interrogated in 108 punch samples. Clonal heterogeneity was infrequent: a pattern of clonal heterogeneity consistent with a role in metastasis formation was observed only in 1 case in a single gene (p. Asp604Tyr of the PTPRT gene). However, when comparing variant allele frequencies (VAFs) of genomic variants in adjacent positions on chromosomes (“matched genomic variant loci”) across punch samples, differences that exceeded 2 SD of the NGS assay variations (ad hoc dubbed VAF dysbalance) were observed in 7.1% of the punch samples (2.6%-12.0% per case), which indicates an intricate intermixing of mutated and nonmutated tumor cells (“intrinsic heterogeneity”). Additional OncoScan array analyses on a subset of the punch samples (31 in total) showed gross genomic aberrations as a possible explanation in only some (39.2%) of the matched genomic variant loci with VAF dysbalance. Our study provides a fairly direct (statistical model-free) view of the genomic states of microsatellite-stable colorectal carcinomas and their metastases, and suggests that Darwinian-type tumor evolution is not the key pathway of the metastasizing disease; instead, we recorded an “intrinsic” genomic heterogeneity, which may echo an initial Big Bang-like event.

Distributed synchronization based on model-free reinforcement learning in wireless ad hoc networks

Time synchronization is a key issue in wireless ad hoc networks. Due to the dynamic characteristics of such networks, distributed synchronization (DS) is preferred for its reliability and validity. However, one major drawback of this synchronization mechanism is that nodes exchange time synchronization messages with their neighbors, which can be very time-consuming. In order to reduce network synchronization overhead while maintaining synchronization quality, this paper presents a model-free reinforcement learning distributed synchronization (RLDS) by evaluating the current network state and node synchronization level, adaptively deciding that the current node interacts with a certain portion of its neighbors instead of all of them for synchronization information. The simulation results indicated that during the initial network synchronization, RLDS achieves the same synchronization accuracy as the traditional DS, while reducing the total communication overhead by 15%. The superiority of RLDS is more evident in the long-term maintenance of network synchronization, reducing the communication overhead by 48% during 500 rounds of synchronization. This is because the number of node neighbors in communication can be appropriately reduced, thus achieving an adaptive trade-off between ensuring time synchronization and saving communication overhead. This study shows the latent capacity of reinforcement learning in improving the performance of traditional ad hoc networking technologies.

DNA-methylation and genomic copy number in primary tumors and corresponding lymph node metastases in prostate cancer from patients with low and high Gleason score

In prostate cancer, the indication to irradiate the pelvic lymphatic pathways in clinical node-negative patients is solely based on clinical nomograms. To define biological risk patterns of lymphatic spread, we studied DNA-methylation and genomic copy number in primary tumors and corresponding lymph nodes metastases. DNA-methylation and genomic copy number profiles of primary tumors (PT) and paired synchronous lymph node metastases (LN) from Gleason Score (GS)-6/7a (n=20 LN-positive, n=20 LN-negative) and GS-9/10 patients (LN-positive n=20) after prostatectomy and lymphonodectomy were analyzed. GS-6/7a pN0 PTs and GS-6/7a pN1 PTs differed in histone H3K27me3/H3K9me3 mediated methylation. PTs compared to LNs, in both, GS-6/7a pN1 and GS-9/10 pN1 patients showed large differences in DNA-methylation mediated by histones H3K4me1/2, in addition to copy number changes of chromosomal regions 11q13.1, 14q11.2 and 15q26.1. Between GS-6/7a pN1 and GS-9/10 pN1 patients, methylation levels differed more when comparing LNs than PTs. 16q21-22.1 was specifically lost in GS-9/10 pN0 PTs. Immune system-related pathways characterized the differences between PTs and LNs in both GS-6/7a pN1 and GS-9/10 pN1 patients. Comparing PTs and LKs between GS-6/7a pN1 and GS-9/10 pN1 patients revealed altered transmembrane and G-protein-coupled receptor signaling. Our data suggest that progression of prostate cancer, including lymphatic spread, is associated with histone-mediated DNA-methylation and we hypothesize a methylation signature predicting lymphatic spread in GS-6/7a patients from primary tumors. Lymphatic spread in GS-6/7a patients, flanked by DNA-methylation and CNA alterations, appears to be more complex than in GS-9/10 patients, in whom the primary tumors already appear to bear lymph node metastasis-enabling alterations.

LIMCH1 protein expression associated with lymph node metastasis in breast cancer

Background. Lymph node metastasis in breast cancer is not only a variant of cancer progression, but is also associated with the development of hematogenous metastases. The LIMCH1 protein is involved in the mesenchymal type of migration due to the activation of non-muscle myosin IIA.The objective of the study was to investigate the association of different LIMCH1 protein expression variants with lymph node metastasis.Material and Methods. The retrospective study included 53 patients with invasive breast carcinoma of no special type. The study group included all molecular genetic types (luminal A, luminal B, HER2-positive and triple negative). The median age of the patients was 55.4 ± 14 years. According to the TNM classification, patients had stage T1–3N0–3M0 breast cancer. The patients did not receive preoperative chemotherapy. The expression of the LIMCH1 protein in tumor cells was assessed using immunohistochemistry. Anti-LIMCH1Prestige (HPA004184, Sigma Aldrich, Germany) and anti-LIMCH1-C-term (SAB2700402, Sigma Aldrich, Germany) antibodies were used.Results. Lymph node metastases were more frequent in patients with LIMCH1 protein expression in tumor cells. This is true for cytoplasmic expression of the LIMCH1 protein detected by the CH domain, but not for submembrane expression or expression of the LIMCH1 protein detected by the LIM domain, regardless of localization in the cell. This phenomenon was not associated with the morphological heterogeneity of breast cancer. The most unfavorable factor for worse metastasis-free survival is the combination of the presence of lymph node metastases and cytoplasmic expression of the LIMCH1 protein detected by the CH domain.Conclusion. The development of synchronous lymph node metastases in breast cancer is associated with the presence of cytoplasmic expression of the LIMCH1 protein detected by the CH domain in the primary tumor tissue.