To see the other types of publications on this topic, follow the link: Global Data Synchronization Network.
Journal articles on the topic 'Global Data Synchronization Network'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Global Data Synchronization Network.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Chen, Hui-Chuan, and Edmund Prater. "Information System Costs of Utilizing Electronic Product Codes in Achieving Global Data Synchronization within the Pharmaceutical Supply Chain Network." International Journal of Information Systems and Supply Chain Management 6, no. 1 (January 2013): 62–76. http://dx.doi.org/10.4018/jisscm.2013010104.
Full textAbstract:
Numerous benefits of implementation of global data synchronization (GDSN) in the pharmaceutical supply chain have been identified, including reduced counterfeiting, decreased medication errors, increased supply chain efficiency, and standardized regulatory evolution. For this study, a complete GDSN supply chain framework was developed as a model for the industry to achieve Global Standard (GS1) standards. Each supply chain member must have a strong enterprise resource planning (ERP) information system to accommodate the initial electronic product code information services (EPCIS). A web-based Datapool—which connects the manufacturer, distributor, and retailer—will assist in reaching the data synchronization stage. The most important step is to have an open standard of GS1 global registry to enable the Epedigree to be traced through the supply chain system. When combined with EPCIS, as well as electronic product code global (EPCglobal) standardization and GS1 Global Registry, the supply chain can achieve global data synchronization and traceability. The comprehensive GDSN framework provided in this study provides the pharmaceutical industry an estimate of the total costs of attaining a global data synchronization network.
2
Faizullin, Marsel, Anastasiia Kornilova, Azat Akhmetyanov, and Gonzalo Ferrer. "Twist-n-Sync: Software Clock Synchronization with Microseconds Accuracy Using MEMS-Gyroscopes." Sensors 21, no. 1 (December 24, 2020): 68. http://dx.doi.org/10.3390/s21010068.
Full textAbstract:
Sensor networks require a high degree of synchronization in order to produce a stream of data useful for further purposes. Examples of time misalignment manifest as undesired artifacts when doing multi-camera bundle-adjustment or global positioning system (GPS) geo-localization for mapping. Network Time Protocol (NTP) variants of clock synchronization can provide accurate results, though present high variance conditioned by the environment and the channel load. We propose a new precise technique for software clock synchronization over a network of rigidly attached devices using gyroscope data. Gyroscope sensors, or IMU, provide a high-rate measurements that can be processed efficiently. We use optimization tools over the correlation signal of IMU data from a network of gyroscope sensors. Our method provides stable microseconds accuracy, regardless of the number of sensors and the conditions of the network. In this paper, we show the performance of the gyroscope software synchronization in a controlled environment, and we evaluate the performance in a sensor network of smartphones by our open-source Android App, Twist-n-Sync, that is publicly available.
3
Nicol, Ruth M., Sandra C. Chapman, Petra E. Vértes, Pradeep J. Nathan, Marie L. Smith, Yury Shtyrov, and Edward T. Bullmore. "Fast reconfiguration of high-frequency brain networks in response to surprising changes in auditory input." Journal of Neurophysiology 107, no. 5 (March 1, 2012): 1421–30. http://dx.doi.org/10.1152/jn.00817.2011.
Full textAbstract:
How do human brain networks react to dynamic changes in the sensory environment? We measured rapid changes in brain network organization in response to brief, discrete, salient auditory stimuli. We estimated network topology and distance parameters in the immediate central response period, <1 s following auditory presentation of standard tones interspersed with occasional deviant tones in a mismatch-negativity (MMN) paradigm, using magnetoencephalography (MEG) to measure synchronization of high-frequency (gamma band; 33–64 Hz) oscillations in healthy volunteers. We found that global small-world parameters of the networks were conserved between the standard and deviant stimuli. However, surprising or unexpected auditory changes were associated with local changes in clustering of connections between temporal and frontal cortical areas and with increased interlobar, long-distance synchronization during the 120- to 250-ms epoch (coinciding with the MMN-evoked response). Network analysis of human MEG data can resolve fast local topological reconfiguration and more long-range synchronization of high-frequency networks as a systems-level representation of the brain's immediate response to salient stimuli in the dynamically changing sensory environment.
4
Kumar, N. Suresh, Mallikharjuna Rao K, Mahesh Kothuru, and Y. Narasimha Rao. "Multi-dimensional parametric assessment with IoT in acquaintance of digital pipeline." International Journal of Electrical and Computer Engineering (IJECE) 9, no. 6 (December 1, 2019): 4649. http://dx.doi.org/10.11591/ijece.v9i6.pp4649-4656.
Full textAbstract:
In IoT researches are found millions of devices are connected in global digital infrastructure framed in network fashion. Most of the things on the network use cloud or central database to share their data and control signals to control and manage the devices on the IoT network. Devices on the network need fast traversing paths, to take correct decision in right time. The data synchronization between source and destination is very important in real time parameter maintenance. The multidimensional parametric evaluation of the environment or the surrounding area is facing problems with data synchronization and congestion in the sensor network. This will lead arrival of fault data at the destination. The fault data also leads a misconception at user end. In the present work pipeline integration is proposed to overcome the misconception and synchronization failures. The pipeline and Arduino UNO processor are integrated on Proteus simulation tool. Transducer nodes and the functionalities are analysed with pipeline.
5
Zhao, Dezong, Qingqing Ding, Shangmin Zhang, Chunwen Li, and Richard Stobart. "Integrated Feedback Scheduling and Control Codesign for Motion Coordination of Networked Induction Motor Systems." Mathematical Problems in Engineering 2014 (2014): 1–14. http://dx.doi.org/10.1155/2014/578569.
Full textAbstract:
This paper investigates the codesign of remote speed control and network scheduling for motion coordination of multiple induction motors through a shared communication network. An integrated feedback scheduling algorithm is designed to allocate the optimal sampling period and priority to each control loop to optimize the global performance of a networked control system (NCS), while satisfying the constraints of stability and schedulability. A speed synchronization method is incorporated into the scheduling algorithm to improve the speed synchronization performance of multiple induction motors. The rational gain of the network speed controllers is calculated using the Lyapunov theorem and tuned online by fuzzy logic to guarantee the robustness against complicated variations on the communication network. Furthermore, a state predictor is designed to compensate the time delay which occurred in data transmission from the sensor to the controller, as a part of the networked controller. Simulation results support the effectiveness of the proposed control-and-scheduling codesign approach.
6
Ermakov, A. V., and L. I. Suchkova. "Development of algorithms of self-organizing network for reliable data exchange between autonomous robots." Dependability 20, no. 2 (June 8, 2020): 35–42. http://dx.doi.org/10.21683/1729-2646-2020-20-2-35-42.
Full textAbstract:
Factors affecting the reliability of data transmission in networks with nodes with periodic availability were considered. The principles of data transfer between robots are described; the need for global connectivity of communications within an autonomous system is shown, since the non-availability of information on the intentions of other robots reduces the effectiveness of the robotics system as a whole and affects the fault tolerance of a team of independent actors performing distributed activities. It is shown that the existing solutions to the problem of data exchange based on general-purpose IP networks have drawbacks; therefore, as the basis for organizing autonomous robot networks, we used developments in the domain of topological models of communication systems allowing us to build self-organizing computer networks. The requirements for the designed network for reliable message transfer between autonomous robots are listed, the option of organizing reliable message delivery using overlay networks, which expand the functionality of underlying networks, is selected. An overview of existing popular controlled and non-controlled overlay networks is given; their applicability for communication within a team of autonomous robots is evaluated. The features and specifics of data transfer in a team of autonomous robots are listed. The algorithms and architecture of the overlay self-organizing network were described by means of generally accepted methods of constructing decentralized networks with zero configurations. As a result of the work, general principles of operation of the designed network were proposed, the message structure for the delivery algorithm was described; two independent data streams were created, i.e. service and payload; an algorithm for sending messages between network nodes and an algorithm for collecting and synchronizing the global network status were developed. In order to increase the dependability and fault tolerance of the network, it is proposed to store the global network status at each node. The principles of operation of a distributed storage are described. For the purpose of notification on changes in the global status of the network, it is proposed to use an additional data stream for intra-network service messages. A flood routing algorithm was developed to reduce delays and speed up the synchronization of the global status of a network and consistency maintenance. It is proposed to provide network connectivity using the HELLO protocol to establish and maintain adjacency relations between network nodes. The paper provides examples of adding and removing network nodes, examines possible scalability problems of the developed overlay network and methods for solving them. It confirms the criteria and indicators for achieving the effect of self-organization of nodes in the network. The designed network is compared with existing alternatives. For the developed algorithms, examples of latency estimates in message delivery are given. The theoretical limitations of the overlay network in the presence of intentional and unintentional defects are indicated; an example of restoring the network after a failure is set forth.
7
Lu, Wenlian, Ren Zheng, and Tianping Chen. "Centralized and decentralized global outer-synchronization of asymmetric recurrent time-varying neural network by data-sampling." Neural Networks 75 (March 2016): 22–31. http://dx.doi.org/10.1016/j.neunet.2015.11.006.
Full text
8
Milbredt, Paul, Efim Schick, and Michael Hübner. "Energy Efficiency Due to a Common Global Timebase—Synchronizing FlexRay to 802.1AS Networks as a Foundation." Journal of Low Power Electronics and Applications 8, no. 3 (August 17, 2018): 26. http://dx.doi.org/10.3390/jlpea8030026.
Full textAbstract:
Modern automotive control applications require a holistic time-sensitive development. Nowadays, this is achieved by technologies specifically designed for the automotive domain, like FlexRay, which offer a fault-tolerant time synchronization mechanism built into the protocol. Currently, the automotive industry adopts the Ethernet within the car, not only for embedding consumer electronics, but also as a fast and reliable backbone for control applications. Still, low-cost but highly reliable sensors connected over the traditional Controller Area Network (CAN) deliver data needed for autonomous driving. To fusion the data efficiently among all, a common timebase is required. The alternative would be oversampling, which uses more time and energy, e.g., at least double the perception rates of sensors. Ethernet and CAN do require the latter by default. Hence, a global synchronization mechanism eases tremendously the design of a low power automotive network and is the foundation of a transparent global clock. In this article, we present the first step: Synchronizing legacy FlexRay networks to the upcoming Ethernet backbone, which will contain a precise clock over the generalized Precision Time Protocol (gPTP) defined in IEEE 802.1AS. FlexRay then could still drive its strengths with deterministic transmission behavior and possibly also serve as a redundant technology for fail-operational system design.
9
Xu, Zhaowen, Peng Shi, Hongye Su, Zheng-Guang Wu, and Tingwen Huang. "Global $H_\infty $ Pinning Synchronization of Complex Networks With Sampled-Data Communications." IEEE Transactions on Neural Networks and Learning Systems 29, no. 5 (May 2018): 1467–76. http://dx.doi.org/10.1109/tnnls.2017.2673960.
Full text
10
Kuharskaya, O. V., and E. Z. Savin. "Influence of Synchronization Signal Inaccuracy on DVB-T2 Local Content Insertion." Journal of the Russian Universities. Radioelectronics, no. 1 (April 17, 2018): 19–24. http://dx.doi.org/10.32603/1993-8985-2018-21-1-19-24.
Full textAbstract:
The article is aimed at specifying criteria of synchronization signal inaccuracy when DVB-T2 system local content re-placement cannot be carried out. Some settings of digital information stream are set as the initial data. The first part of the article specifies network delay calculation method. The second part of the article considers the signal cycle instability impact on estimation of local content device delay during its insertion in global information flow. Network delay saw-toothlike dependence on time is revealed, statistical parameters of synchronization signal instability are specified. The third part of the article deals with analysis of method of substitution of two independent information flows by regionali-zation device. A model of T2 superframes comprising baseband frames (BB frames) which belong to different physical layer pipes (PLP) is described. The conditions under which the local information insertion becomes impossible are de-fined. Besides, the article considers other reasons of failure during single frequency networks (SFN) processing of local content insertion dealing with synchronization error at different stages of information flow digital content generation and delivery to DVB-T2.
11
LIU, XIAO FAN, and CHI K. TSE. "A COMPLEX NETWORK PERSPECTIVE OF WORLD STOCK MARKETS: SYNCHRONIZATION AND VOLATILITY." International Journal of Bifurcation and Chaos 22, no. 06 (June 2012): 1250142. http://dx.doi.org/10.1142/s0218127412501428.
Full textAbstract:
This paper studies the cross-correlations of 67 stock market indices in the past 5 years. In order to capture the interaction of the stock markets, we propose to take a complex network approach to analyzing the interdependence of the individual stock markets. Specifically, stock markets are considered as network nodes, and the network links (weights of links) are defined by the cross-correlations between market indices over a period of time (time window). Thus, the resulting network provides information about the interdependence of individual markets, with the network links representing the extents to which the markets are correlated. If we allow the time window to move in forward time and construct a network for each time window over a long period of time, we are able to capture the dynamics of the network. In our study, all networks are constructed from raw data of market indices, and our aim is to investigate how network properties can be used to infer market behavior. By examining the variation of the network parameters as time elapses, we show that stock markets of different countries have time-varying interaction, and that developed markets tend to demonstrate similar behavior while emerging markets are statistically independent of each other. Furthermore, we observe synchronization in the network of stock markets, which is an important universal property observed in many physical and man-made networks. Specifically, we show that stock markets of different countries generally behave in a synchronous manner when they experience fluctuation, which is especially notable in the developed markets. This work exposes the interdependence of stock markets in the world and proposes a complex network approach to identifying some salient global behavior of the interconnecting markets.
12
McCarthy, Philip James, and Christopher Nielsen. "Global Synchronization of Sampled-Data Invariant Systems on Exponential Lie Groups." IEEE Transactions on Control of Network Systems 7, no. 3 (September 2020): 1080–89. http://dx.doi.org/10.1109/tcns.2019.2963019.
Full text
13
Wang, Yan-Wu, Tao Bian, Jiang-Wen Xiao, and Changyun Wen. "Global Synchronization of Complex Dynamical Networks Through Digital Communication With Limited Data Rate." IEEE Transactions on Neural Networks and Learning Systems 26, no. 10 (October 2015): 2487–99. http://dx.doi.org/10.1109/tnnls.2014.2387443.
Full text
14
Baltakys, Kęstutis, Hung Le Viet, and Juho Kanniainen. "Structure of Investor Networks and Financial Crises." Entropy 23, no. 4 (March 24, 2021): 381. http://dx.doi.org/10.3390/e23040381.
Full textAbstract:
In this paper, we ask whether the structure of investor networks, estimated using shareholder registration data, is abnormal during a financial crises. We answer this question by analyzing the structure of investor networks through several most prominent global network features. The networks are estimated from data on marketplace transactions of all publicly traded securities executed in the Helsinki Stock Exchange by Finnish stock shareholders between 1995 and 2016. We observe that most of the feature distributions were abnormal during the 2008–2009 financial crisis, with statistical significance. This paper provides evidence that the financial crisis was associated with a structural change in investors’ trade time synchronization. This indicates that the way how investors use their private information channels changes depending on the market conditions.
15
Liu, Longgeng, Guangchun Luo, Ke Qin, and Xiping Zhang. "An on-demand global time synchronization based on data analysis for wireless sensor networks." Procedia Computer Science 129 (2018): 503–10. http://dx.doi.org/10.1016/j.procs.2018.03.031.
Full text
16
González, Almudena, Manuel Santapau, Antoni Gamundí, Ernesto Pereda, and Julián J. González. "Modifications in the Topological Structure of EEG Functional Connectivity Networks during Listening Tonal and Atonal Concert Music in Musicians and Non-Musicians." Brain Sciences 11, no. 2 (January 26, 2021): 159. http://dx.doi.org/10.3390/brainsci11020159.
Full textAbstract:
The present work aims to demonstrate the hypothesis that atonal music modifies the topological structure of electroencephalographic (EEG) connectivity networks in relation to tonal music. To this, EEG monopolar records were taken in musicians and non-musicians while listening to tonal, atonal, and pink noise sound excerpts. EEG functional connectivities (FC) among channels assessed by a phase synchronization index previously thresholded using surrogate data test were computed. Sound effects, on the topological structure of graph-based networks assembled with the EEG-FCs at different frequency-bands, were analyzed throughout graph metric and network-based statistic (NBS). Local and global efficiency normalized (vs. random-network) measurements (NLE|NGE) assessing network information exchanges were able to discriminate both music styles irrespective of groups and frequency-bands. During tonal audition, NLE and NGE values in the beta-band network get close to that of a small-world network, while during atonal and even more during noise its structure moved away from small-world. These effects were attributed to the different timbre characteristics (sounds spectral centroid and entropy) and different musical structure. Results from networks topographic maps for strength and NLE of the nodes, and for FC subnets obtained from the NBS, allowed discriminating the musical styles and verifying the different strength, NLE, and FC of musicians compared to non-musicians.
17
Tang, Jian Bing, Qing Song Zhao, and Ya Bing Zha. "Real-Time Validation for Satellite Navigation Signal Simulation System." Applied Mechanics and Materials 667 (October 2014): 153–56. http://dx.doi.org/10.4028/www.scientific.net/amm.667.153.
Full textAbstract:
The satellite navigation signal system is so useful that it can provide autonomous geo-spatial positioning with global coverage. The satellite navigation signal simulation system possesses the traits of large scale, complex structure and various model types, and the real-time performance of the simulation system is exigent. The simulation real-time performance index will be analyzed and tested roundly. Firstly, the framework of the satellite navigation signal simulation system is introduced. Secondly, several index such as simulation step-time, time function and network data transfers, which can affect the real-time performance of the simulation system, are analyzed. Finally, four real-time performance indexes such as frame overflow, the definition of frame synchronization and time synchronization, the precision of time synchronization etc, are tested and validated in detail. By analysis and test, the result shows that this simulation system possessing higher real-time performance and it can meet the real-time simulation requirement of the simulation system. This simulation system can also be used to validate the real satellite navigation signal system.
18
Ahmad, Iftikhar, Rafidah Md Noor, Roobaea Alroobaea, Muhammad Talha, Zaheed Ahmed, Umm-e. Habiba, and Ihsan Ali. "Aiding Traffic Prediction Servers through Self-Localization to Increase Stability in Complex Vehicular Clustering." Complexity 2021 (January 19, 2021): 1–11. http://dx.doi.org/10.1155/2021/6627539.
Full textAbstract:
The integration of cellular networks and vehicular networks is complex and heterogeneous. Synchronization among vehicles in heterogeneous vehicular clusters plays an important role in effective data sharing and the stability of the cluster. This synchronization depends on the smooth exchange of information between vehicles and remote servers over the Internet. The remote servers predict road traffic patterns by adopting deep learning methods to help drivers on the roads. At the same time, local data processing at the vehicular cluster level may increase the capabilities of remote servers. However, global positioning system (GPS) signal interruption, especially in the urban environment, plays a big part in the detritions of synchronization among the vehicles that lead to the instability of the cluster. Instability of connections is a major hurdle in developing cost-effective solutions for deriving assistance and route planning applications. To solve this problem, a self-localization scheme within the vehicular cluster is proposed. The proposed self-localization scheme handles GPS signal interruption to the vehicle within the cluster. A unique clustering criterion and a synchronization mechanism for sharing traffic information system (TIS) data among multiple vehicles are developed. The developed scheme is simulated and compared with existing known approaches. The results show the better performance of our proposed scheme over others.
19
Nelson, Roger D. "Evoked Potentials and GCP Event Data." Journal of Scientific Exploration 34, no. 2 (June 7, 2020): 246–67. http://dx.doi.org/10.31275/20201475.
Full textAbstract:
Evoked potentials (EP) are measured in time-locked synchronization with repetitions of the same stimulus. The electrical measure in raw form is extremely noisy, reflecting not only responses to the imposed stimulus but also a large amount of normal, but unrelated activity. In the raw data no structure related to the stimulus is apparent, so the process is repeated many times, yielding multiple epochs that can be averaged. Such “signal averaging” reduces or washes out random fluctuations while structured variation linked to the stimulus builds up over multiple samples. The resulting pattern usually shows a large excursion preceded and followed by smaller deviations with a typical time-course relative to the stimulus.The Global Consciousness Project (GCP) maintains a network of random number generators (RNG) running constantly at about 60 locations around the world, sending streams of 200-bit trials generated each second to be archived as parallel random sequences. Standard processing for most analyses computes a network variance measure for each second across the parallel data streams. This is the raw data used to calculate a figure of merit for each formal test of the GCP hypothesis: we predict non-random structure in data taken during “global events” that engage the attention of large numbers of people. The data are combined across all seconds of the event to give a representative Z-score, and typically displayed graphically as a cumulative deviation from expectation showing the history of the data sequence. For the present work, we treat the raw data in the same way measured electrical potentials from the brain are processed to reveal temporal patterns. In both cases the signal to noise ratio is very small, requiring signal averaging to reveal structure in what otherwise appears to be random data.Applying this model to analyze GCP data from events that show significant departures from expectation, we find patterns that look like those found in EP work. While this assessment is limited to visual comparisons, the degree of similarity is striking. It suggests that human brain activity in response to stimuli may be a useful model to guide further research addressing th
20
TSONIS, ANASTASIOS A., and KYLE L. SWANSON. "CLIMATE MODE COVARIABILITY AND CLIMATE SHIFTS." International Journal of Bifurcation and Chaos 21, no. 12 (December 2011): 3549–56. http://dx.doi.org/10.1142/s0218127411030714.
Full textAbstract:
It has previously been shown from the collective behavior of a network of observed climate indices that this network synchronized several times in the period 1900–2000. Further, it has been found that in those cases where the synchronous state was followed by a steady increase in the coupling strength between the indices, the synchronous state was destroyed, after which a new climate state emerged. These shifts are associated with significant changes in global temperature trend and in El Niño/Southern Oscillation variability. Subsequently, the evidence for such type of behavior has been found to occur in three climate simulations using state-of-the-art models as well as in the observed data in the 21st century. This was the first time that this mechanism, which appears consistent with the theory of synchronized chaos, has been discovered in a physical system of the size and complexity of the climate system. Here we extend this approach to consider proxy data for climate modes going back several centuries. While noise in the proxy data in some cases masks the mechanism, we find significant coherence between both synchronization and coupling and global temperature. These results provide further support that the above mechanism for climate shifts is a robust feature of the climate system.
21
MANDAL, PARTHA SARATHI, and KRISHNENDU MUKHOPADHYAYA. "MOBILE AGENT BASED CHECKPOINTING WITH CONCURRENT INITIATIONS." International Journal of Foundations of Computer Science 18, no. 05 (October 2007): 1107–22. http://dx.doi.org/10.1142/s0129054107005157.
Full textAbstract:
Traditional message passing based checkpointing and rollback recovery algorithms perform well for tightly coupled systems. In wide area distributed systems these algorithms may suffer from large overhead due to message passing delay and network traffic. Mobile agents offer an attractive option for designing checkpointing schemes for wide area distributed systems. Network topology is assumed to be arbitrary. Processes are mobile agent enabled. When a process wants to take a checkpoint, it just creates one mobile agent. Concurrent initiations by multiple processes are allowed. Synchronization and creation of a consistent global state (CGS) for checkpointing is managed by the mobile agent(s). In the worst case, for k concurrent initiations among n processes, checkpointing algorithm requires a total of O(kn) hops by all the mobile agents. A mobile agent carries O(n/k) (on the average) size data.
22
Yang, Guangyu, Daolin Xu, and Haicheng Zhang. "Closeness-centrality-correlation for detecting interdependency between coupled systems." Modern Physics Letters B 35, no. 19 (June 12, 2021): 2150216. http://dx.doi.org/10.1142/s021798492150216x.
Full textAbstract:
Generalized synchronization is a common interdependency between coupled systems which exists in many branches of life, social and physical science. In this paper, a novel method, called closeness-centrality-correlation is proposed for the detection of this interdependency. The proposed method is based on a global network measure (i.e., closeness centrality) of recurrence networks resulting from time series. We illustrate the feasibility of the proposed method using a paradigmatic coupled model and compare its performance to other commonly used interdependency methods. The numerical results show that the proposed method is quite satisfactory for detecting interdependency and outperforms the existing joint probability of recurrence method especially for the case that the dynamics of the two coupled subsystems are significantly different. Moreover, through analyzing the time series contaminated by white noise, we demonstrate that our method is robust against white noise. Finally, an application to recorded electroencephalogram data shows that the proposed measure is more reliable to detect the transitions of the interdependencies among the noisy electroencephalogram time series and thus provides longer pre-warning time for the onset of epilepsy.
23
Andreotti, Amedeo, Bianca Caiazzo, Alberto Petrillo, Stefania Santini, and Alfredo Vaccaro. "Decentralized Smart Grid Voltage Control by Synchronization of Linear Multiagent Systems in the Presence of Time-Varying Latencies." Electronics 8, no. 12 (December 3, 2019): 1470. http://dx.doi.org/10.3390/electronics8121470.
Full textAbstract:
Modern power distribution systems require reliable, self-organizing and highly scalable voltage control systems, which should be able to promptly compensate the voltage fluctuations induced by intermittent and non-programmable generators. However, their deployment in realistic operation scenarios is still an open issue due, for example, to the presence of non-ideal and unreliable communication systems that allow each component within the power network to share information about its state. Indeed, due to technological constraints, time-delays in data acquisition and transmission are unavoidable and their effects have to be taken into account in the control design phase. To this aim, in this paper, we propose a fully distributed cooperative control protocol allowing the voltage control to be achieved despite the presence of heterogeneous time-varying latencies. The idea is to exploit the distributed intelligence along the network, so that it is possible to bring out an optimal global behavior via cooperative distributed control action that leverages both local and the outdated information shared among the devices within the power network. Detailed simulation results obtained on the realistic case study of the IEEE 30-bus test system are presented and discussed in order to prove the effectiveness of the proposed approach in the task of solving complex voltage control problems. Finally, a robustness analysis with respect to both loads variations and hard communication delays was also carried to disclose the efficiency of the approach.
24
Park, Mingyu, and Jeongyeup Paek. "On-Demand Scheduling of Command and Responses for Low-Power Multihop Wireless Networks." Sensors 21, no. 3 (January 22, 2021): 738. http://dx.doi.org/10.3390/s21030738.
Full textAbstract:
Many IoT applications require a mechanism to disseminate commands and collect responses over a wireless network in order to control and collect data from multiple embedded devices. However, severe collisions may occur if a large number of nodes attempt to respond simultaneously and promptly, not only among the responses, but also with the dissemination of commands. This is because low-power wireless network protocols for dissemination and collection have been designed separately. Tuning the parameters of one side of the protocol has clear trade-off between reliability and latency. To address this challenge, we propose SCoRe, an on-demand scheme for joint scheduling of command and responses on multihop low-power wireless networks to improve both reliability and latency simultaneously at runtime. SCoRe gathers the amount of time required by network nodes for dissemination and collection, and allocates relative timeslots to each node recursively over multihop on-demand when (and only when) disseminating a command. While doing so, information exchange occurs only between local neighbor nodes without a need for global routing table nor time synchronization. We implement SCoRe on a low-power embedded platform, and compare with well-known dissemination and collection schemes through both simulations and testbed experiments on 30 devices. Our evaluation results show that SCoRe can improve both latency and reliability without tuning the parameters for one metric, while the legacy schemes require careful parameter selection to match only one side of SCoRe, never both.
25
Ramani,, Karthik, Abhishek Agrawal, and, Mahendra Babu, and Christoph Hoffmann. "CADDAC: Multi-Client Collaborative Shape Design System with Server-based Geometry Kernel." Journal of Computing and Information Science in Engineering 3, no. 2 (June 1, 2003): 170–73. http://dx.doi.org/10.1115/1.1582882.
Full textAbstract:
New and efficient paradigms for web-based collaborative product design in a global economy will be driven by increased outsourcing, increased competition, and pressures to reduce product development time. We have developed a three-tier (client-server-database) architecture based collaborative shape design system, Computer Aided Distributed Design and Collaboration (CADDAC). CADDAC has a centralized geometry kernel and constraint solver. The server-side provides support for solid modeling, constraint solving operations, data management, and synchronization of clients. The client-side performs real-time creation, modification, and deletion of geometry over the network. In order to keep the clients thin, many computationally intensive operations are performed at the server. Only the graphics rendering pipeline operations are performed at the client-side. A key contribution of this work is a flexible architecture that decouples Application Data (Model), Controllers, Viewers, and Collaboration. This decoupling allows new feature development to be modular and easy to develop and manage.
26
Li, Xin, Tao Che, Xinwu Li, Lei Wang, Anmin Duan, Donghui Shangguan, Xiaoduo Pan, Miao Fang, and Qing Bao. "CASEarth Poles: Big Data for the Three Poles." Bulletin of the American Meteorological Society 101, no. 9 (September 1, 2020): E1475—E1491. http://dx.doi.org/10.1175/bams-d-19-0280.1.
Full textAbstract:
Abstract Unprecedented changes in the climate and environment have been observed in the three poles, including the North Pole, the South Pole, and the Third Pole–Tibetan Plateau. Although considerable data have been collected and several observation networks have been built in these polar regions, the three poles are relatively data-scarce regions due to inaccessible data acquisition, high-cost labor, and difficult living environments. To address the obstacles to better understanding the unprecedented changes in the three poles and their effects on the global environment and humans, there is a pressing need for better data acquisition, curation, integration, service, and application to support fundamental scientific research and sustainable development for the three poles. CASEarth Poles, a project within the framework of the “CAS Big Earth Data Science Engineering” program of the Chinese Academy of Sciences, aims to construct a big data platform for the three poles. CASEarth Poles will be devoted to 1) breaking the bottleneck of polar data curation, integration, and sharing; 2) developing high-resolution remote sensing products over the three poles; 3) generating atmospheric reanalysis datasets for the polar regions; 4) exploring the synchronization, asynchronization, and teleconnection of the environmental changes in the three poles; 5) investigating the climate, water cycle, and ecosystem dynamics and the interactions among the multispheres in the polar regions and their global effects; and 6) supporting decision-making with regard to sea ice forecasting, infrastructure, and sustainable development in polar regions. CASEarth Poles will collaborate with international efforts to enable better data and information services for the three poles in the big data era.
27
Kong, Wanzeng, Bei Jiang, Qiaonan Fan, Li Zhu, and Xuehui Wei. "Personal Identification Based on Brain Networks of EEG Signals." International Journal of Applied Mathematics and Computer Science 28, no. 4 (December 1, 2018): 745–57. http://dx.doi.org/10.2478/amcs-2018-0057.
Full textAbstract:
Abstract Personal identification is particularly important in information security. There are numerous advantages of using electroencephalogram (EEG) signals for personal identification, such as uniqueness and anti-deceptiveness. Currently, many researchers focus on single-dataset personal identification, instead of the cross-dataset. In this paper, we propose a method for cross-dataset personal identification based on a brain network of EEG signals. First, brain functional networks are constructed from the phase synchronization values between EEG channels. Then, some attributes of the brain networks including the degree of a node, the clustering coefficient and global efficiency are computed to form a new feature vector. Lastly, we utilize linear discriminant analysis (LDA) to classify the extracted features for personal identification. The performance of the method is quantitatively evaluated on four datasets involving different cognitive tasks: (i) a four-class motor imagery task dataset in BCI Competition IV (2008), (ii) a two-class motor imagery dataset in the BNCI Horizon 2020 project, (iii) a neuromarketing dataset recorded by our laboratory, (iv) a fatigue driving dataset recorded by our laboratory. Empirical results of this paper show that the average identification accuracy of each data set was higher than 0.95 and the best one achieved was 0.99, indicating a promising application in personal identification.
28
Kumar Sahu, Prabhat, Susrita Mahapatro, and Pradeep Kumar Dash. "Comparison between Different Queue Management Techniques in Mobile Ad-Hoc Network: A Survey." International Journal of Engineering & Technology 7, no. 2.6 (March 11, 2018): 182. http://dx.doi.org/10.14419/ijet.v7i2.6.10564.
Full textAbstract:
The world is running in a lightning speed with the rapid up gradation of technology. In fraction of second human civilization experiences a unique set of technologies and for this human sentiment started to demand better quality of service in almost all the areas which provides ease to it by minimizing human work efforts. Communication becomes an integral part of this rapidly changing technology. From the introduction of internet, the taste and preferences of virtual communication has been changed. A new technology called as Mobile Ad Hoc Network (MANet) is also getting its popularity due to its infrastructure less and mobility property. The rapid increase in demand for use of MANets tends it to further development to provide better quality of service. However Congestion in these networks creates a challenge to achieve desired Quality of Service. Different Queue Management techniques such as Passive and Active Queue management techniques are used to minimize the congestion in these networks which uses the concept of managing the buffers though algorithms. The Passive Queue Management technique Droptail, in the introduction stage, somehow manages to increase its efficiency. However in later stage, when data traffic increases, due to global synchronization problem many other algorithms including active queue management techniques such as RED and variants, REM have been developed to increase the efficiency by decreasing the congestion. The concepts even travel from congestion control to congestion avoidance. In this paper we have taken into account different passive and active queue management techniques and compared them based on our literature review to find out the best among them by considering different situations.
29
Tarjan, Laslo, Ivana Šenk, Jelena Erić Obućina, Stevan Stankovski, and Gordana Ostojić. "Extending Legacy Industrial Machines by a Low-Cost Easy-to-Use IoT Module for Data Acquisition." Symmetry 12, no. 9 (September 10, 2020): 1486. http://dx.doi.org/10.3390/sym12091486.
Full textAbstract:
Industry 4.0 is a paradigm that enhances industrial automation systems with the recent advances in the domain of the Internet of Things (IoT), gaining new possibilities and providing new services. Traditional industrial machines do not have IoT capabilities, and in order to integrate such a machine into Industry 4.0, there is a need for an intermediary device or system that communicates with the machine through its supported communication interfaces and protocols and forwards the communication to the global network. This paper presents the development and experimental validation of a low-cost hardware module that can easily integrate the machine’s existing control unit into the IoT and enable synchronization of the measurements and states of the variables of the machine and its environment with a cloud server. The developed module is universal, can connect to any control unit that is able to communicate through basic RS232 serial communication, and does not require the control unit to have any higher level communication protocol implemented. On the other end, the presented solution uses a dedicated smartphone application to provide remote monitoring and control of the machine through the cloud by using the synchronized variable states, as well as further possibilities for storing, processing, and analyzing the historical data from the system. The developed solution was experimentally validated on an experimental setup consisting of a conveyor belt driven by a three-phase asynchronous electromotor controlled by a programmable logic controller through a variable-frequency drive.
30
Hyder, Waheeduddin, Miguel-Ángel Luque-Nieto, Javier Poncela, and Pablo Otero. "Self-Organized Proactive Routing Protocol for Non-Uniformly Deployed Underwater Networks." Sensors 19, no. 24 (December 12, 2019): 5487. http://dx.doi.org/10.3390/s19245487.
Full textAbstract:
Electromagnetic (EM) waves cannot propagate more than few meters in sea water due to the high absorption rate. Acoustic waves are more suitable for underwater communication, but they travel very slowly compared to EM waves. The typical speed of acoustic waves in water is 1500 m/s, whereas speed of EM waves in air is approximately 3 × 108 m/s. Therefore, the terrestrial wireless sensor network (WSN) protocols assume that the propagation delay is negligible. Hence, reactive protocols are deemed acceptable for WSNs. Other important issues related to underwater wireless sensor networks (UWSNs) are determining the position of the underwater nodes and keeping a time synchronization among the nodes. Underwater nodes can neither determine their position nor synchronize using Global Navigation Satellite Systems (GNSS) because of the short penetration of EM waves in sea water. The limited mobility of UWSN nodes and variation in the propagation speed of acoustic waves make time synchronization a challenging task for underwater acoustic networks (UASNs). For all these reasons, WSN protocols cannot be readily used in UASNs. In this work, a protocol named SPRINT is designed to achieve high data throughput and low energy operation in the nodes. There is a tradeoff between the throughput and the energy consumption in the wireless networks. Longer links mean higher energy consumption. On the other hand, the number of relay nodes or hops between the source node and the final destination node is a key factor which affects the throughput. Each hop increases the delay in the packet forwarding and, as a result, decreases the throughput. Hence, energy consumption requires the nearest nodes to be chosen as forwarding nodes, whereas the throughput requires the farthest node to be selected to minimize the number of hops. SPRINT is a cross-layer, self-organized, proactive protocol which does not require positioning equipment to determine the location of the node. The routing path from the node to the gateway is formed based on the distance. The data sending node prefers to choose the neighbor node which is closest to it. The distance is measured by the signal strength between the two nodes.
31
Gouzman, Michael, and Serge Luryi. "Reflections on the Future Electric Power Grid Monitoring System." International Journal of High Speed Electronics and Systems 23, no. 03n04 (September 2014): 1450024. http://dx.doi.org/10.1142/s0129156414500244.
Full textAbstract:
A shortcoming of the contemporary power grid monitoring is that the system does not know its own state. Instead of taking automatic note of energy-flow disruptions, one deals with haphazard telephone reports of “no light in our house”. We propose a novel monitoring system that requires no restructuring of the power distribution network and can be applied both to the existing grids and the future “smart grids”. The proposed system is based on a network of inexpensive sensors, installed on every connecting line and communicating measured data to a central processing unit. Our approach is topological in nature, based on the connectivity aspects of the power grid embodied in Kirchhoff's current law that must be valid at every node of the network. We argue that the state of the network can be adequately characterized by specifying the RMS currents and the direction of energy flow in all connecting lines. It is essential that in this description one does not have to know the magnitude of the energy flow, only its direction. This eliminates the need to measure voltage, which would be prohibitively costly on the massive scale. In contrast, the relative phase between the current and voltage can be measured easily. Another essential point is that the instantaneous RMS currents are impractical to record and communicate, hence local averaging is required. Since Kirchhoff's law should remain valid upon averaging, the latter must be carried out at each sensor synchronously over the entire network with global synchronization provided by the GPS.
32
Boffi, Nicholas M., and Jean-Jacques E. Slotine. "A Continuous-Time Analysis of Distributed Stochastic Gradient." Neural Computation 32, no. 1 (January 2020): 36–96. http://dx.doi.org/10.1162/neco_a_01248.
Full textAbstract:
We analyze the effect of synchronization on distributed stochastic gradient algorithms. By exploiting an analogy with dynamical models of biological quorum sensing, where synchronization between agents is induced through communication with a common signal, we quantify how synchronization can significantly reduce the magnitude of the noise felt by the individual distributed agents and their spatial mean. This noise reduction is in turn associated with a reduction in the smoothing of the loss function imposed by the stochastic gradient approximation. Through simulations on model nonconvex objectives, we demonstrate that coupling can stabilize higher noise levels and improve convergence. We provide a convergence analysis for strongly convex functions by deriving a bound on the expected deviation of the spatial mean of the agents from the global minimizer for an algorithm based on quorum sensing, the same algorithm with momentum, and the elastic averaging SGD (EASGD) algorithm. We discuss extensions to new algorithms that allow each agent to broadcast its current measure of success and shape the collective computation accordingly. We supplement our theoretical analysis with numerical experiments on convolutional neural networks trained on the CIFAR-10 data set, where we note a surprising regularizing property of EASGD even when applied to the non-distributed case. This observation suggests alternative second-order in time algorithms for nondistributed optimization that are competitive with momentum methods.
33
Steriade, M. "Impact of Network Activities on Neuronal Properties in Corticothalamic Systems." Journal of Neurophysiology 86, no. 1 (July 1, 2001): 1–39. http://dx.doi.org/10.1152/jn.2001.86.1.1.
Full textAbstract:
Data from in vivo and in vitro experiments are discussed to emphasize that synaptic activities in neocortex and thalamus have a decisive impact on intrinsic neuronal properties in intact-brain preparations under anesthesia and even more so during natural states of vigilance. Thus the firing patterns of cortical neuronal types are not inflexible but may change with the level of membrane potential and during periods rich in synaptic activity. The incidences of some cortical cell classes (defined by their responses to depolarizing current pulses) are different in isolated cortical slabs in vivo or in slices maintained in vitro compared with the intact cortex of naturally awake animals. Network activities, which include the actions of generalized modulatory systems, have a profound influence on the membrane potential, apparent input resistance, and backpropagation of action potentials. The analysis of various oscillatory types leads to the conclusion that in the intact brain, there are no “pure” rhythms, generated in simple circuits, but complex wave sequences (consisting of different, low- and fast-frequency oscillations) that result from synaptic interactions in corticocortical and corticothalamic neuronal loops under the control of activating systems arising in the brain stem core or forebrain structures. As an illustration, it is shown that the neocortex governs the synchronization of network or intrinsically generated oscillations in the thalamus. The rhythmic recurrence of spike bursts and spike trains fired by thalamic and cortical neurons during states of decreased vigilance may lead to plasticity processes in neocortical neurons. If these phenomena, which may contribute to the consolidation of memory traces, are not constrained by inhibitory processes, they induce seizures in which the neocortex initiates the paroxysms and controls their thalamic reflection. The results indicate that intact-brain preparations are necessary to investigate global brain functions such as behavioral states of vigilance and paroxysmal activities.
34
Thanh Duc, Nguyen, Samuel Silverstein, Martin Wik, Patrick Crill, David Bastviken, and Ruth K. Varner. "Technical note: Greenhouse gas flux studies: an automated online system for gas emission measurements in aquatic environments." Hydrology and Earth System Sciences 24, no. 7 (July 6, 2020): 3417–30. http://dx.doi.org/10.5194/hess-24-3417-2020.
Full textAbstract:
Abstract. Aquatic ecosystems are major sources of greenhouse gases (GHGs). Robust measurements of natural GHG emissions are vital for evaluating regional to global carbon budgets and for assessing climate feedbacks of natural emissions to improve climate models. Diffusive and ebullitive (bubble) transport are two major pathways of gas release from surface waters. To capture the high temporal variability of these fluxes in a well-defined footprint, we designed and built an inexpensive device that includes an easily mobile diffusive flux chamber and a bubble counter all in one. In addition to automatically collecting gas samples for subsequent various analyses in the laboratory, this device also utilized a low-cost carbon dioxide (CO2) sensor (SenseAir, Sweden) and methane (CH4) sensor (Figaro, Japan) to measure GHG fluxes. Each of the devices was equipped with an XBee module to enable local radio communication (DigiMesh network) for time synchronization and data readout at a server controller station on the lakeshore. The software of this server controller was operated on a low-cost computer (Raspberry Pi), which has a 3G connection for remote control and monitor functions from anywhere in the world. This study shows the potential of a low-cost automatic sensor network system for studying GHG fluxes on lakes in remote locations.
35
Schumacher, Johannes, Thomas Wunderle, Pascal Fries, Frank Jäkel, and Gordon Pipa. "A Statistical Framework to Infer Delay and Direction of Information Flow from Measurements of Complex Systems." Neural Computation 27, no. 8 (August 2015): 1555–608. http://dx.doi.org/10.1162/neco_a_00756.
Full textAbstract:
In neuroscience, data are typically generated from neural network activity. The resulting time series represent measurements from spatially distributed subsystems with complex interactions, weakly coupled to a high-dimensional global system. We present a statistical framework to estimate the direction of information flow and its delay in measurements from systems of this type. Informed by differential topology, gaussian process regression is employed to reconstruct measurements of putative driving systems from measurements of the driven systems. These reconstructions serve to estimate the delay of the interaction by means of an analytical criterion developed for this purpose. The model accounts for a range of possible sources of uncertainty, including temporally evolving intrinsic noise, while assuming complex nonlinear dependencies. Furthermore, we show that if information flow is delayed, this approach also allows for inference in strong coupling scenarios of systems exhibiting synchronization phenomena. The validity of the method is demonstrated with a variety of delay-coupled chaotic oscillators. In addition, we show that these results seamlessly transfer to local field potentials in cat visual cortex.
36
Loviknes, Karina, Zeinab Jeddi, Lars Ottemöller, and Thibaut Barreyre. "When Clocks Are Not Working: OBS Time Correction." Seismological Research Letters 91, no. 4 (May 27, 2020): 2247–58. http://dx.doi.org/10.1785/0220190342.
Full textAbstract:
Abstract Ocean-bottom seismographs (OBSs) are used to obtain seismic recordings offshore and are an increasingly important tool for investigating the globe. However, because OBS data cannot be time stamped using Global Positioning System (GPS) during deployment, correction for drift of the internal clock is required. This time drift is typically derived by synchronizing the clock before and after deployment. Linear correction is then applied using the timing deviation between GPS and the instrument’s internal clock at recovery, that is, the skew measurement. If synchronization measurements are missing, ambient noise cross-correlation functions (CCFs) are commonly used for time correction. When investigating recordings from a small-scale OBS network located on the Mohn’s mid-ocean ridge, we observed a remaining drift on the skew-corrected data. After recalculating the drift of the raw data using CCFs, we found that the skew-based time correction was incorrect. This was also verified with the observation of teleseismic P-wave arrivals. We describe a method to obtain properly time-corrected data and discuss the OBS timing issues in detail. The results shown were obtained using a software package that we developed for this specific purpose and made available as open-source software. Although we cannot explain the technical reason for the failure of skew correction, this study shows that skew corrections should not be trusted alone, and OBS timing should always be verified by either ambient noise correlations or P-wave arrival times.
37
Sun, Chun-I., Jung-Tang Huang, Shih-Chi Weng, and Meng-Fan Chien. "City Marathon Active Timing System Using Bluetooth Low Energy Technology." Electronics 8, no. 2 (February 22, 2019): 252. http://dx.doi.org/10.3390/electronics8020252.
Full textAbstract:
This study proposes and implements city marathon timing technology using Bluetooth Low-Energy (BLE) communication technology. This study also performs a prevalidation of the athletes’ physiological sensory data that is sent out by the same timing system—the BLE active communication technology. In order to verify the timing and positioning technology, 621 K records of static measurement of the Received Signal Strength Indicator (RSSI) were first collected. The trend of the RSSI between the location and the BLE Receiver when the runners carried a BLE Tag was analyzed. Then, the difference between the runners’ passing timestamp and the runners’ actual passing time when the runners carried a BLE Tag and ran past the BLE Receivers was dynamically recorded and analyzed. Additionally, the timing sensing rate when multiple runners ran past the BLE Receivers was verified. In order to confirm the accuracy of the time synchronization in the remote timing device, the timing error, synced by the Network Time Protocol (NTP), was analyzed. A global positioning system (GPS) signal was used to enhance the time synchronization’s accuracy. Additionally, the timing devices were separated by 15 km, and it was verified that they remained within the timing error range of 1 ms. The BLE communication technology has at least one more battery requirement than traditional passive radio frequency identification (RFID) timing devices. Therefore, the experiment also verified that the BLE Tag of this system can continue to operate for at least 48 h under normal conditions. Based on the above experimental results, it is estimated that the system can provide a timing error of under ±156 ms for each athlete. The system can also meet the scale of the biggest international city marathon event.
38
Dou, Ziming, Elena Naumova, Ryan Simpson, Lauren E. Sallade, Yutong Zhang, Kristin Leonberg, Emily Sanchez, and Bingjie Zhou. "Seasonal Associations Between Foodborne Campylobacter Infections and Ambient Temperature in US, 2010–2019." Current Developments in Nutrition 5, Supplement_2 (June 2021): 85. http://dx.doi.org/10.1093/cdn/nzab060_003.
Full textAbstract:
Abstract Objectives In order to effectively mitigate the effects of climate change on human health, spatiotemporal relationships between Campylobacter infections and environmental drivers have to be systematically examined to determine whether common seasonal summer peaks observed in Campylobacter infections are well aligned with peaks in raising ambient temperatures. This study aims to evaluate the seasonal relationship between monthly ambient temperature and the monthly Campylobacter infections routinely collected by the CDC Foodborne Diseases Active Surveillance Network (FoodNet) in the United States in 2010–2019. Methods We created time series of monthly Campylobacter infection rates from the FoodNet Fast platform for ten participating states from January 2010 to December 2019 (120 months). We estimated average monthly temperatures for the ten states for the study period using the National Climate and Data Center's Global Summary of the Day database. To assess the seasonal synchronization and determine the lag effect, we used serial cross-correlation analysis. To examine the associations between Campylobacter rates with ambient temperature and adjust for seasonality and trend, we applied a harmonic negative binomial mixed-effects regression model. We also estimated peak timing and amplitude for infections and temperature using the δ-method. Results Serial synchronization between monthly Campylobacter infection rates and ambient temperature was observed in all FoodNet Surveillance states except for California. A one-month delay in peak infection after the peak in temperature was detected in Colorado, Connecticut, Maryland, Minnesota, New Mexico, New York, and Oregon. After adjusting for seasonality and trend across ten states, the relative risk of infection rates increased by 5% with the increase in monthly average temperature by 5.45°C equivalent to a shift from 75th to 95th percentile (95%CI: 1.02–1.09, p < 0.002). Conclusions An increase in monthly average temperature is associated with an increased risk of Campylobacter infection after adjusting for common summer seasonal patterns. Knowledge of the relationship will potentially improve the reliability and accuracy of integrated early warning outbreak forecasts and could guide climate mitigation strategies. Funding Sources None.
39
Yu, Yang, Qingyu Hou, Wei Zhang, and Jinxiu Zhang. "A Sequential Two-Stage Track-to-Track Association Method in Asynchronous Bearings-Only Sensor Networks for Aerial Targets Surveillance." Sensors 19, no. 14 (July 19, 2019): 3185. http://dx.doi.org/10.3390/s19143185.
Full textAbstract:
Successful track-to-track association (TTTA) in a multisensor and multitarget scenario is predicated on a reasonable likelihood function to evaluate the similarity of asynchronous mono tracks. To deal with the lack of synchronous data and prior knowledge of the targets in practical applications, this paper investigates a global optimization method with a novel likelihood function constructed by finite asynchronous measurements with joint temporal and spatial constraints (JTSC). For a scenario with more than two independent sensors, a sequential two-stage strategy is proposed to calculate the similarity of multiple asynchronous mono tracks. For the first stage, based on the temporal features of measurements from different sensors, a pairwise fusion model to estimate the position of the target with two mono tracks is established based on the asynchronous crossing location approach. For the other stage, to evaluate the similarity of the outputs, a pairwise similarity model is constructed by searching for the optimal matching points by setting temporal and spatial constraints. Thus, the likelihood of multiple asynchronous tracks is obtained. Simulations are performed to verify that the proposed method can achieve favorable performance without data-synchronization, and also demonstrate the superiority over the methods based on hinge angle differences (HADs) in some scenarios.
40
Brummitt, Charles D., George Barnett, and Raissa M. D'Souza. "Coupled catastrophes: sudden shifts cascade and hop among interdependent systems." Journal of The Royal Society Interface 12, no. 112 (November 2015): 20150712. http://dx.doi.org/10.1098/rsif.2015.0712.
Full textAbstract:
An important challenge in several disciplines is to understand how sudden changes can propagate among coupled systems. Examples include the synchronization of business cycles, population collapse in patchy ecosystems, markets shifting to a new technology platform, collapses in prices and in confidence in financial markets, and protests erupting in multiple countries. A number of mathematical models of these phenomena have multiple equilibria separated by saddle-node bifurcations. We study this behaviour in its normal form as fast–slow ordinary differential equations. In our model, a system consists of multiple subsystems, such as countries in the global economy or patches of an ecosystem. Each subsystem is described by a scalar quantity, such as economic output or population, that undergoes sudden changes via saddle-node bifurcations. The subsystems are coupled via their scalar quantity (e.g. trade couples economic output; diffusion couples populations); that coupling moves the locations of their bifurcations. The model demonstrates two ways in which sudden changes can propagate: they can cascade (one causing the next), or they can hop over subsystems. The latter is absent from classic models of cascades. For an application, we study the Arab Spring protests. After connecting the model to sociological theories that have bistability, we use socioeconomic data to estimate relative proximities to tipping points and Facebook data to estimate couplings among countries. We find that although protests tend to spread locally, they also seem to ‘hop' over countries, like in the stylized model; this result highlights a new class of temporal motifs in longitudinal network datasets.
41
Brecht, Michael, Wolf Singer, and Andreas K. Engel. "Correlation Analysis of Corticotectal Interactions in the Cat Visual System." Journal of Neurophysiology 79, no. 5 (May 1, 1998): 2394–407. http://dx.doi.org/10.1152/jn.1998.79.5.2394.
Full textAbstract:
Brecht, Michael, Wolf Singer, and Andreas K. Engel. Correlation analysis of corticotectal interactions in the cat visual system. J. Neurophysiol. 79: 2394–2407, 1998. We have studied the temporal relationship between visual responses in various visual cortical areas [17, 18, postero medial lateral suprasylvian (PMLS), postero lateral lateral suprasylvian (PLLS), 21a]) and the superficial layers of the cat superior colliculus (SC). To this end, simultaneous recordings were performed in one or several visual cortical areas and the SC of anesthetized paralyzed cats, and visually evoked multiunit responses were subjected to correlation analysis. Significant correlations occurred in 117 (24%) of 489 cortex-SC pairs and were found for all cortical areas recorded. About half of the significant correlograms showed an oscillatory modulation. In these cases, oscillation frequencies covered a broad range, the majority being in the alpha- and beta-band. On average, significant center peaks in cross-correlograms had a modulation amplitude of 0.34. Our analysis revealed a considerable intertrial variability of correlation patterns with respect to both correlation strength and oscillation frequency. Furthermore, cortical areas differed in their corticotectal correlation patterns. The percentage of cells involved a corticotectal correlation, as well as the percentage of significantly modulated correlograms in such cases, was low for areas 17 and PMLS but high for areas 18 and PLLS. Analysis of the cortical layers involved in these interactions showed that consistent temporal relationships between cortical and collicular responses were not restricted to layer V. Our data demonstrate a close relationship between corticotectal interactions and intracortical or intracollicular synchronization. Trial-by-trial analysis from these sites revealed a clear covariance of corticotectal correlations with intracortical synchronization. The probability of observing corticotectal interactions increased with enhanced local cortical and collicular synchronization and, in particular, with interareal cortical correlations. Corticotectal correlation patterns resemble in many ways those described among areas of the visual cortex. However, the correlations observed are weaker than those between nearby cortical sites, exhibit usually broader peaks and for some cortical areas show consistent phase-shifts. Corticotectal correlations represent population phenomena that reflect both the local and global temporal organization of activity in the cortical and collicular network and do not arise from purely monosynaptic interactions. Our findings show that both striate and extrastriate inputs affect the superficial SC in a cooperative manner and, thus, do not support the view that responses in the superficial SC depend exclusively on input from the primary visual areas as implied by the concept of “two corticotectal systems.” We conclude that the corticotectal projections convey temporal activation patterns with high reliability, thus allowing the SC evaluation of information encoded in the temporal relations between responses of spatially disseminated cortical neurons. As a consequence, information distributed across multiple cortical areas can affect the SC neurons in a coherent way.
42
Zhang, Jin-E. "Centralized Data-Sampling Approach for GlobalOt-αSynchronization of Fractional-Order Neural Networks with Time Delays." Discrete Dynamics in Nature and Society 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/6157292.
Full textAbstract:
In this paper, the globalO(t-α)synchronization problem is investigated for a class of fractional-order neural networks with time delays. Taking into account both better control performance and energy saving, we make the first attempt to introduce centralized data-sampling approach to characterize theO(t-α)synchronization design strategy. A sufficient criterion is given under which the drive-response-based coupled neural networks can achieve globalO(t-α)synchronization. It is worth noting that, by using centralized data-sampling principle, fractional-order Lyapunov-like technique, and fractional-order Leibniz rule, the designed controller performs very well. Two numerical examples are presented to illustrate the efficiency of the proposed centralized data-sampling scheme.
43
Zou, Deyue, and Shouchuan Ma. "Satellite Navigation and Communication Integration Based on Correlation Domain Indefinite Pulse Position Modulation Signal." Wireless Communications and Mobile Computing 2021 (June 7, 2021): 1–11. http://dx.doi.org/10.1155/2021/5545285.
Full textAbstract:
Ubiquitous signal coverage is a basic demand of Internet of Things (IoT) communications, which meets the feature of satellite communications. Infinite user number is a basic demand of IoT location-based services, which meets the feature of Global Navigation Satellite System (GNSS). Both of these demands make Satellite Navigation and Communication Integration (SNCI) an important supporting technology for IoT. Inherited from the satellite communications system, GNSS itself has a certain data transmission capacity. Thus, enhancing the communication function of the GNSS is a promising means of achieving SNCI. Considering that a unified signal system cannot currently realize high-precision positioning and high-speed data transmission simultaneously in SNCI, this project proposes a Correlation Domain Indefinite Pulse Position Modulation (CDIPPM). A pilot channel and a data channel are introduced in this technology, which are distinguished by Code Division Multiplexing (CDMA). The synchronization function is provided by the pilot channel, thereby freeing the data channel of this function. The phase of the pseudorandom code can then be used as the carrier of information. In order to transmit more information, the transmitter of the proposed technology superimposes on the data channel multiple sets of spread spectrum sequence, which are generated from one set of spread spectrum sequence by different cyclic shifting operations. The receiver will identify the number and location of the correlation function peaks by a detection algorithm and recover the message. It can be seen by theoretical analysis and simulation verification. The technology can significantly improve satellite data transmission rates and maintain the original positioning function while minimizing change in the original GNSS signal. Therefore, the SNCI system based on this technology has the following advantages: a unified signal system, high positioning accuracy, high data transmission rate, and a backward navigation function, and it is easy to promote.
44
Gabryś, Marta, and Łukasz Ortyl. "Georeferencing of Multi-Channel GPR—Accuracy and Efficiency of Mapping of Underground Utility Networks." Remote Sensing 12, no. 18 (September 11, 2020): 2945. http://dx.doi.org/10.3390/rs12182945.
Full textAbstract:
Due to the capabilities of non-destructive testing of inaccessible objects, GPR (Ground Penetrating Radar) is used in geology, archeology, forensics and increasingly also in engineering tasks. The wide range of applications of the GPR method has been provided by the use of advanced technological solutions by equipment manufacturers, including multi-channel units. The acquisition of data along several profiles simultaneously allows time to be saved and quasi-continuous information to be collected about the subsurface situation. One of the most important aspects of data acquisition systems, including GPR, is the appropriate methodology and accuracy of the geoposition. This publication aims to discuss the results of GPR measurements carried out using the multi-channel Leica Stream C GPR (IDS GeoRadar Srl, Pisa, Italy). The significant results of the test measurement were presented the idea of which was to determine the achievable accuracy depending on the georeferencing method using a GNSS (Global Navigation Satellite System) receiver, also supported by time synchronization PPS (Pulse Per Second) and a total station. Methodology optimization was also an important aspect of the discussed issue, i.e., the effect of dynamic changes in motion trajectory on the positioning accuracy of echograms and their vectorization products was also examined. The standard algorithms developed for the dedicated software were used for post-processing of the coordinates and filtration of echograms, while the vectorization was done manually. The obtained results provided the basis for the confrontation of the material collected in urban conditions with the available cartographic data in terms of the possibility of verifying the actual location of underground utilities. The urban character of the area limited the possibility of the movement of Leica Stream C due to the large size of the instrument, however, it created the opportunity for additional analyses, including the accuracy of different location variants around high-rise buildings or the agreement of the amplitude distribution at the intersection of perpendicular profiles.
45
Chen, Cheng, and Wei Zhu. "Synchronization Analysis of Boolean Network." Applied Mechanics and Materials 432 (September 2013): 528–32. http://dx.doi.org/10.4028/www.scientific.net/amm.432.528.
Full textAbstract:
Boolean network and its synchronization have been gradually used to the global behavior analysis of large gene regulatory network. Network synchronization depends mainly on the dynamics of each node and the topology of the network. In this paper, using the semi-tensor product of matrices, a necessary and sufficient condition based on transition matrix for Boolean network complete synchronization is presented. The synchronization of Boolean control network is also discussed. Two examples are given to illustrate the theoretical result.
46
Wang, Yan-Wu, Jiang-Wen Xiao, and Hua O. Wang. "Global synchronization of complex dynamical networks with network failures." International Journal of Robust and Nonlinear Control 20, no. 15 (August 19, 2010): 1667–77. http://dx.doi.org/10.1002/rnc.1537.
Full text
47
Apsel, Alyssa B., and Enkhbayasgalan Gantsog. "Global synchronization and the challenges of building network awareness." XRDS: Crossroads, The ACM Magazine for Students 22, no. 2 (December 30, 2015): 36–39. http://dx.doi.org/10.1145/2845151.
Full text
48
Yang, Xiaoli, and Manman Wang. "The evolution to global burst synchronization in a modular neuronal network." Modern Physics Letters B 30, no. 14 (May 29, 2016): 1650210. http://dx.doi.org/10.1142/s0217984916502109.
Full textAbstract:
In this paper, we investigated the development of global burst synchronization in a modular neuronal network at the mesoscale level. The modular network consists of some subnetworks, each of them presenting a scale-free property. Numerical results have demonstrated that, upon increasing the coupling strength, all neurons in the modular network initially burst in a desynchronous pattern; then the burst synchronization within each subnetwork is followed at the mesoscale; finally, the global burst synchronization at the macroscale is formed by the bursting activities on each subnetwork moving forward in harmony. This implies the network behavior possesses two distinct mesoscopic and macroscopic properties for some coupling strengths, i.e. the mesoscopic dynamics of burst synchronization on subnetworks is different from the macroscopic property of desynchronous activity on the whole network. It is also found that global burst synchronization can be promoted by large interconnection probability and hindered by small interconnection probability.
49
MURGUIA, C., R. H. B. FEY, and H. NIJMEIJER. "NETWORK SYNCHRONIZATION BY DYNAMIC DIFFUSIVE COUPLING." International Journal of Bifurcation and Chaos 23, no. 04 (April 2013): 1350076. http://dx.doi.org/10.1142/s0218127413500764.
Full textAbstract:
The problem of controlled network synchronization for a class of nonlinear observable systems interconnected via dynamic diffusive coupling is studied. We construct a dynamic diffusive coupling combining a nonlinear observer and an output feedback controller. Sufficient conditions on the systems to be interconnected, on the network topology, and on the coupling strength that guarantee (global) synchronization are derived. Moreover, using the notion of semipassivity, we prove that under some mild assumptions, the solutions of interconnected semipassive systems are ultimately bounded. The results are illustrated by computer simulations of coupled FitzHugh–Nagumo oscillators.
50
Yuan, Zhengzhong, Jianping Cai, and Meili Lin. "Global Synchronization in Complex Networks with Adaptive Coupling." Mathematical Problems in Engineering 2010 (2010): 1–10. http://dx.doi.org/10.1155/2010/826721.
Full textAbstract:
Global synchronization in adaptive coupling networks is studied in this paper. A new simple adaptive controller is proposed based on a concept of asymptotically stable led by partial state variables. Under the proposed adaptive update law, the network can achieve global synchronization without calculating the eigenvalues of the outer coupling matrix. The update law is only dependent on partial state variables of individual oscillators. Numerical simulations are given to show the effectiveness of the proposed method, in which the unified chaotic system is chosen as the nodes of the network with different topologies.