Journal articles: 'Synchronizing scheme'

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WAH WU, CHAI, GUO-QUN ZHONG, and LEON O. CHUA. "SYNCHRONIZING NONAUTONOMOUS CHAOTIC SYSTEMS WITHOUT PHASE-LOCKING." Journal of Circuits, Systems and Computers 06, no. 03 (June 1996): 227–41. http://dx.doi.org/10.1142/s0218126696000182.

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Pecora and Carroll1 have shown how two nonautonomous chaotic circuits driven by periodic forcing can be synchronized using the master-slave driving principle. However, in their scheme, the periodic forcing in both circuits needs to be phase-locked through some additional circuitry for the system to synchronize. In this paper, we show two ways in which this can be avoided. In the first scheme, the two circuits are connected in a master-slave driving configuration and the periodic forcing is included in the driving signal such that it eliminates the need for the slave circuit to have an external periodic forcing signal. In addition, we can recover the periodic forcing signal at the slave circuit. In the second scheme, the two circuits are connected in a mutual coupling configuration. The two circuits will synchronize regardless of what the periodic forcing signals of the two circuits are. In particular, the two periodic forcing signals could have different phases, different frequencies, or different shapes. We discuss two interpretations of these synchronization schemes. First, we consider them as communication systems when the periodic forcing signal is replaced by a properly encoded information signal. We illustrate this in a physical circuit implementation. Second, we consider them as synchronization schemes for nonidentical systems by considering the external forcing signal as an error signal due to the difference between the two systems.

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Guo, Jie, David Zhang, and Peng-fei Shi. "Self-synchronizing watermarking scheme for an arbitrarily shaped object." Pattern Recognition 36, no. 11 (November 2003): 2737–41. http://dx.doi.org/10.1016/s0031-3203(03)00048-7.

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Liu, Tao, Avishai (Avi) Ceder, Jihui Ma, and Wei Guan. "Synchronizing Public Transport Transfers by Using Intervehicle Communication Scheme." Transportation Research Record: Journal of the Transportation Research Board 2417, no. 1 (January 2014): 78–91. http://dx.doi.org/10.3141/2417-09.

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Yeo, Sang-Soo, Dae-il Park, and Young-Ae Jung. "Enhanced ID-Based Authentication Scheme Using OTP in Smart Grid AMI Environment." Journal of Applied Mathematics 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/208424.

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This paper presents the vulnerabilities analyses of KL scheme which is an ID-based authentication scheme for AMI network attached SCADA in smart grid and proposes a security-enhanced authentication scheme which satisfies forward secrecy as well as security requirements introduced in KL scheme and also other existing schemes. The proposed scheme uses MDMS which is the supervising system located in an electrical company as a time-synchronizing server in order to synchronize smart devices at home and conducts authentication between smart meter and smart devices using a new secret value generated by an OTP generator every session. The proposed scheme has forward secrecy, so it increases overall security, but its communication and computation overhead reduce its performance slightly, comparing the existing schemes. Nonetheless, hardware specification and communication bandwidth of smart devices will have better conditions continuously, so the proposed scheme would be a good choice for secure AMI environment.

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Feng, Jianwen, Phillip Yam, Francis Austin, and Chen Xu. "Synchronizing the Noise-Perturbed Rössler Hyperchaotic System via Sliding Mode Control." Zeitschrift für Naturforschung A 66, no. 1-2 (February 1, 2011): 6–12. http://dx.doi.org/10.1515/zna-2011-1-202.

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This paper investigates the synchronization problem between two unidirectionally-coupled Rössler hyperchaotic systems in the presence of noise perturbations. Sufficient conditions are obtained for synchronization by using a particularly simple linear sliding mode surface that is based on the sliding mode control concept. Only one controller function is needed to achieve synchronization in our present approach which makes it much easier to implement in contrast to many other synchronization schemes that require two or more controllers. Numerical simulation results are also included to illustrate the superior features of this new scheme.

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ENDO, TETSURO, and LEON O. CHUA. "SYNCHRONIZING CHAOS FROM ELECTRONIC PHASE-LOCKED LOOPS." International Journal of Bifurcation and Chaos 01, no. 03 (September 1991): 701–10. http://dx.doi.org/10.1142/s0218127491000518.

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This note presents the first experimental demonstration that two similar phase-locked loops driven by a common chaotic signal derived from a master phase-locked loop can be synchronized under some suitably chosen but robust range of system parameters. Experimental observations are qualitatively consistent with both computer simulations, and with the recent synchronization criterion due to Pecora and Carrol. The robustness of this synchronization scheme suggests the intriguing possibility of using chaos as the scrambling codes for spread spectrum communications.

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Wang, Jin Feng, Zhen Feng Shi, Zhe Qu, and Shan Shan Li. "Research and Implementation of Oracle Database Synchronization Timing." Advanced Materials Research 989-994 (July 2014): 4917–19. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.4917.

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In the practical application of developmental internet, often synchronizing Oracle database tables, the establishment of a reliable remote database synchronization scheme is necessary. The paper uses the EXP/IMP logical backup tool of oracle, tuning of EXP/IMP, and combined with shell command, to implement a remote database synchronization scheme. In addition, this program implements the timing of the Oracle database synchronization.

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Jadoon, Rab, WuYang Zhou, Faizan Haq, Jawad Shafi, Iftikhar Khan, and Waqas Jadoon. "A Reliable Scheme for Synchronizing Multimedia Data Streams under Multicasting Environment." Applied Sciences 8, no. 4 (April 4, 2018): 556. http://dx.doi.org/10.3390/app8040556.

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dos Santos, R. V., and L. H. A. Monteiro. "A scheme for synchronizing clocks connected by a packet communication network." Communications in Nonlinear Science and Numerical Simulation 17, no. 7 (July 2012): 2722–27. http://dx.doi.org/10.1016/j.cnsns.2011.11.031.

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Legorreta, U. Uriostegui, E. S. Tututi Hernández, and G. Arroyo-Correa. "A new scheme of coupling and synchronizing low-dimensional dynamical systems." Revista Mexicana de Física 67, no. 2 Mar-Apr (July 15, 2021): 334–42. http://dx.doi.org/10.31349/revmexfis.67.334.

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A different manner of study synchronization between chaotic systems is presented. This is done by using two different forced coupled nonlinear circuits. The way of coupling the systems under study is different from those used in the analysis of chaos in dynamical systems of low dimensionality. The study of synchronization and how to manipulate it, is carried out through the variation of the couplings by calculating the bifurcation diagrams. We observed that for rather larger values of the coupling between the circuits it is reached total synchronization, while for small values of the coupling it is obtained, in the best of the cases, partial synchronization.

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Todorovic, Branislav, and Vladimir Orlic. "Analysis and optimization of direct sequence spread spectrum scheme for an unmanned aerial vehicle PPM control signal." Facta universitatis - series: Electronics and Energetics 23, no. 3 (2010): 319–32. http://dx.doi.org/10.2298/fuee1003319t.

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Binary pulse-position modulated (PPM) control signal is widely used in remotely controlled unmanned aerial vehicles. It consists of data frames, which contain a synchronizing pulse followed by a number of shorter pulses equal to the number of channels N. In this paper we present analysis and optimization of direct sequence spread spectrum (DS-SS) scheme for PPM control signal protection. That scheme uses (N+1) pseudonoise (PN) sequences: one of them (PN0) is assigned to the synchronizing pulse while the each of the remaining N sequences (PN1,PN2, . . . ,PNN) corresponds to the appropriate channel. At the receiving side, the set of (N+1) passive correlators is used to detect respective PN sequences and to reconstruct data. Onelevel and two-level detection are considered. Threshold settings optimization is based on the Neyman-Pearson procedure. As an additional performance measure we introduce probability of corruptive false alarms. Numerical results are presented.

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Schmitz, Roland, Shujun Li, Christos Grecos, and Xinpeng Zhang. "Towards Robust Invariant Commutative Watermarking-Encryption Based on Image Histograms." International Journal of Multimedia Data Engineering and Management 5, no. 4 (October 2014): 36–52. http://dx.doi.org/10.4018/ijmdem.2014100103.

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Invariant Commutative Watermarking-Encryption means to use a cipher that does not have any impact on a certain feature space, which can thus be used for embedding watermarks either before or after encryption. For example, histogram-based watermarking schemes are invariant to pixel permutations and can be combined with permutation-based ciphers to form a Commutative Watermarking-Encryption (CWE) scheme. However, typical histogram-based watermarking schemes based on comparison of histogram bins are prone to de-synchronization attacks, where the whole histogram is shifted by a certain amount. In this paper the authors investigate the possibility to avoid this kind of attacks by synchronizing the embedding and detection processes, using the mean of the histogram as a calibration point. The resulting watermarking scheme is resistant to three common types of shifts of the histogram, while the advantages of previous histogram-based schemes, especially commutativity of watermarking and permutation-based encryption, are preserved. The authors also report on the results of testing robustness of the scheme against JPEG and JPEG2000 compression.

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Bendali, Fatiha, Eloise Mole Kamga, Jean Mailfert, Alain Quilliot, and Hélène Toussaint. "Synchronizing energy production and vehicle routing." RAIRO - Operations Research 55, no. 4 (July 2021): 2141–63. http://dx.doi.org/10.1051/ro/2021093.

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The emergence of locally produced renewable energies induces the appearance of a new generation of local energy players, which are at the same time producers and consumers. In case of time dependent solar energy production, it raises the question of synchronizing production and consumption. We deal here with this issue, in the context of an experimental Solar Hydrogen (H2) production platform. More precisely, we try here to simultaneously schedule a H2 fueled vehicle which follows a pre-computed route while being compelled to periodically refuel, and the H2 production micro-plant which is required to produce related energy under time dependent production costs and productivity rates, both processes being subject to storage capacity constraints. In order to do it, we design a global dynamic programming (DP) algorithm for the resulting NP-Hard problem. This DP algorithm involves a 2D time space which links energy consumption by the vehicle and its production by the micro-plant. Since the number of states induced by this DP algorithm becomes an issue as soon as the size of the problem increases, we first propose a theoretical Polynomial Time Approximation Scheme (PTAS), next design several practical pruning devices and finally perform numerical tests in order to check their efficiency.

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Wang, Jing, and Hui Zhong. "Synchronization of Continuous Scalar Chaotic Signal from Uncertain Chaotic System." Advanced Materials Research 816-817 (September 2013): 843–46. http://dx.doi.org/10.4028/www.scientific.net/amr.816-817.843.

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This paper presents the synchronizing problem of scalar chaotic signal. A class of nonlinear chaotic systems is discussed which has unknown part in model. The proposed approach is based on canonical form of the response system. Simulation result shows the effectiveness of our synchronization scheme.

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Zhang, Chao, Qiang Guo, and Jing Wang. "Finite-Time Synchronizing Control for Chaotic Neural Networks." Abstract and Applied Analysis 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/938612.

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This paper addresses the finite-time synchronizing problem for a class of chaotic neural networks. In a real communication network, parameters of the master system may be time-varying and the system may be perturbed by external disturbances. A simple high-gain observer is designed to track all the nonlinearities, unknown system functions, and disturbances. Then, a dynamic active compensatory controller is proposed and by using the singular perturbation theory, the control method can guarantee the finite-time stability of the error system between the master system and the slave system. Finally, two illustrative examples are provided to show the effectiveness and applicability of the proposed scheme.

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Moltchanov, D., A. Vinel, J. Jakubiak, and Y. Koucheryavy. "Synchronous Relaying in Vehicular Ad-hoc Networks." International Journal of Wireless Networks and Broadband Technologies 1, no. 2 (April 2011): 36–41. http://dx.doi.org/10.4018/ijwnbt.2011040104.

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In this paper, the authors propose a simple concept for emergency information dissemination in vehicular ad-hoc networks. Instead of competing for the shared wireless medium when transmitting the emergency information, the authors’ proposed method requires nodes to cooperate by synchronizing their transmissions. The proposed scheme is backward compatible with IEEE 802.11p carrier sense multiple access with collision avoidance. The authors also briefly address some of the implementation issues of the proposed scheme.

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SHORT, KEVIN M. "UNMASKING A MODULATED CHAOTIC COMMUNICATIONS SCHEME." International Journal of Bifurcation and Chaos 06, no. 02 (February 1996): 367–75. http://dx.doi.org/10.1142/s0218127496000114.

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This paper will address the problem of unmasking a new chaotic communication scheme using synchronizing circuits, where the Lorenz system is modulated by the message and the x-coordinate of the modulated system is added to the message and transmitted to the receiver. The receiver is driven into perfect synchrony with the transmitter even in the presence of the message, and since the message becomes part of the dynamics it provides very little distortion to the phase space of the dynamical system. However, this paper will demonstrate that it is still possible to extract a sinusoidal message from the transmitted signal. It will also be shown that it is possible to extract the sinusoidal signal solely from the x-coordinate, without secondarily adding back the message sinusoid before transmission. The message extraction is also shown to work for simple frequency-modulated and phase-modulated message signals. The modulated communication scheme does effectively nullify a multi-step unmasking technique which had been somewhat successful when applied to chaotic communication schemes which employed additive message signals.

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Hui, Ma, Zhu Kai-En, and Chen Tian-Lun. "A Self-synchronizing Stream Encryption Scheme Based on One-Dimensional Coupled Map Lattices." Communications in Theoretical Physics 47, no. 4 (April 2007): 679–84. http://dx.doi.org/10.1088/0253-6102/47/4/024.

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Leung, Andrew Y. T., Xian-Feng Li, Yan-Dong Chu, and Xiao-Bo Rao. "A simple adaptive-feedback scheme for identical synchronizing chaotic systems with uncertain parameters." Applied Mathematics and Computation 253 (February 2015): 172–83. http://dx.doi.org/10.1016/j.amc.2014.12.076.

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Mondal, Debasish. "Synchonizing phasor measurement and STATCOM controller in power system stability enhancement." International Journal of Applied Power Engineering (IJAPE) 10, no. 1 (March 1, 2021): 30. http://dx.doi.org/10.11591/ijape.v10.i1.pp30-40.

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<p>This paper presents the concepts of Synchronizing Phasor Measurement (SPM) and its application in addition with a STATCOM controller in order to enhance dynamic stability of a multi-machine power system. The bus voltage under consideration is estimated in the form of digital signal by a Synchronizing Phasor Measurement Unit (SPMU). The DSP based output of the SPMU is then applied to a fixed structure PI type lead-lag digital STATCOM controller. The performance of this discrete-time digital controller is compared with its analog counterpart. The parameters of the analog controller are first tuned with a popular soft computation technique, Particle Swarm optimization (PSO) and later this controller is converted to digital one for simulation with DSP based outputs received from SPMU. The effectiveness of the design of the proposed control scheme is illustrated through time domain simulation of a proposed 3-machine, 9-bus test power system. The simulation results established that the Synchronizing Phasor Measurement based digital control system is more effective and resulting better performance than the continuous-time analog control system in power system stability improvement<em>.</em></p>

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JUNGE, LUTZ, ULRICH PARLITZ, ZARKO TASEV, and LJUPCO KOCAREV. "SYNCHRONIZATION AND CONTROL OF SPATIALLY EXTENDED SYSTEMS USING SENSOR COUPLING." International Journal of Bifurcation and Chaos 09, no. 12 (December 1999): 2265–70. http://dx.doi.org/10.1142/s0218127499001735.

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We investigate the problem of synchronizing and controlling spatially extended systems. For this purpose a coupling scheme is introduced, that allows to synchronize and control the dynamics with only a few driving signals which are spatial averages of local regions. We estimate the optimal arrangement of the coupling signals and compare them with their usual periodic arrangement. The application in controlling, e.g. suppression of chaos, is demonstrated.

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CHEN, J. Y., K. W. WONG, and J. W. SHUAI. "PHASE SYNCHRONIZATION BETWEEN TWO DIFFERENT OSCILLATORS WITH UNIDIRECTIONAL SIGNAL COUPLING." International Journal of Bifurcation and Chaos 14, no. 05 (May 2004): 1877–84. http://dx.doi.org/10.1142/s0218127404010229.

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A control scheme is applied between two different oscillators to study their phase synchronization. It utilizes unidirectional signal coupling and only measures the time interval when the trajectories to the two oscillators' attractors cross the Poincaré surfaces respectively. By using this scheme, phase synchronization (without 2π phase slips) can be obtained between two different chaotic systems whose signal variables have large amplitude mismatch. This unidirectional signal coupling also provides a minimum information flow from the driving system to the response system. Therefore it can be used in synchronizing systems with substantially different dynamics via a channel with low information rate.

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ITOH, MAKOTO, TAO YANG, and LEON O. CHUA. "CONDITIONS FOR IMPULSIVE SYNCHRONIZATION OF CHAOTIC AND HYPERCHAOTIC SYSTEMS." International Journal of Bifurcation and Chaos 11, no. 02 (February 2001): 551–60. http://dx.doi.org/10.1142/s0218127401002262.

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Experimental results show that chaotic and hyperchaotic systems can be synchronized by impulses sampled from one or two state variables. In this paper, we study the conditions under which chaotic and hyperchaotic systems can be synchronized by impulses sampled from a part of their state variables. By calculating the Lyapunov exponents of variational synchronization error systems, we show that this kind of impulsive synchronization can be applied to almost all hyperchaotic systems. We also study the selective synchronization of chaotic systems. In a selective synchronization scheme, the synchronizing signal is chosen in the time periods when the Lyapunov exponents of variational synchronization error systems are negative. Since only driving signals during the time periods when synchronization error can be reduced are applied to reduce the synchronization error, and no signal is applied during the time periods when synchronization error can be increased, selective synchronization scheme can be used to achieve synchronization even in the case when continuous synchronization schemes fail to work.

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Rodriguez-Angeles, Alejandro, and Henk Nijmeijer. "Synchronizing Tracking Control for Flexible Joint Robots via Estimated State Feedback." Journal of Dynamic Systems, Measurement, and Control 126, no. 1 (March 1, 2004): 162–72. http://dx.doi.org/10.1115/1.1636197.

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In this paper, we propose a synchronization controller for flexible joint robots, which are interconnected in a master-slave scheme. The synchronization controller is based on feedback linearization and only requires measurements of the master and slave link positions, since the velocities and accelerations are estimated by means of model-based nonlinear observers. It is shown, using Lyapunov function based stability analysis, that the proposed synchronization controller yields local uniformly ultimately boundedness of the closed loop errors. A tuning gain procedure is presented. The results are supported by simulations in a one degree of freedom master-slave system.

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Zou, Peichao, Sum‐Wai Chiang, Houchao Zhan, Yiming Sui, Kangwei Liu, Shengyu Hu, Songyang Su, Jing Li, Feiyu Kang, and Cheng Yang. "A Periodic “Self‐Correction” Scheme for Synchronizing Lithium Plating/Stripping at Ultrahigh Cycling Capacity." Advanced Functional Materials 30, no. 21 (March 13, 2020): 1910532. http://dx.doi.org/10.1002/adfm.201910532.

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Tai, Weipeng, Dandan Zuo, Jing Han, and Jianping Zhou. "Fuzzy resilient control for synchronizing chaotic systems with time-variant delay and external disturbance." International Journal of Modern Physics B 35, no. 17 (July 2, 2021): 2150177. http://dx.doi.org/10.1142/s0217979221501770.

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This paper focuses on the issue of fuzzy resilient control for synchronizing chaotic systems with time-variant delay and external disturbance. The goal is to design a fuzzy resilient controller with additive gain perturbations to guarantee that not only the drive and response systems are asymptotically synchronized in the absence of external disturbance, but also the synchronization error system has a prescribed disturbance attenuation index under the zero initial condition. By utilizing an appropriate Lyapunov–Krasovskii functional, the Bessel–Legendre inequality, and the reciprocally convex combination technique, a criterion on the stability and [Formula: see text] performance of the synchronization error system is derived. Then, by means of some decoupling methods, a design scheme of the fuzzy resilient controller is developed. Finally, one numerical example is provided to examine the effectiveness of the fuzzy resilient controller design scheme.

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Guyomar, Daniel, Mickaël Lallart, Kaixiang Li, Jean-Yves Gauthier, and Thomas Monnier. "A self-synchronizing and low-cost structural health monitoring scheme based on zero crossing detection." Smart Materials and Structures 19, no. 4 (March 16, 2010): 045017. http://dx.doi.org/10.1088/0964-1726/19/4/045017.

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Chen, J. Y., K. W. Wong, H. Y. Zheng, and J. W. Shuai. "Synchronizing spatiotemporal chaos by introducing a finite flat region in the local map." Discrete Dynamics in Nature and Society 6, no. 3 (2001): 201–6. http://dx.doi.org/10.1155/s1026022601000218.

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An approach to synchronize spatiotemporal chaos is proposed. It is achieved by introducing a finite flat region in the local map. By using this scheme, a number of orbits in both the drive and the response subsystems are forced to pass through a fixed point in every dimension. With only an arbitrary phase space variable as drive signal, synchronization of spatiotemporal chaos can be achieved rapidly in the response subsystem. This is an advantage when compared with other synchronization methods that require a linear combination of the original phase space variables.

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Hamidi, Mohamed, Aladine Chetouani, Mohamed El Haziti, Mohammed El Hassouni, and Hocine Cherifi. "Blind Robust 3D Mesh Watermarking Based on Mesh Saliency and Wavelet Transform for Copyright Protection." Information 10, no. 2 (February 18, 2019): 67. http://dx.doi.org/10.3390/info10020067.

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Three-dimensional models have been extensively used in several applications including computer-aided design (CAD), video games, medical imaging due to the processing capability improvement of computers, and the development of network bandwidth. Therefore, the necessity of implementing 3D mesh watermarking schemes aiming to protect copyright has increased considerably. In this paper, a blind robust 3D mesh watermarking method based on mesh saliency and wavelet transform for copyright protection is proposed. The watermark is inserted by quantifying the wavelet coefficients using quantization index modulation (QIM) according to the mesh saliency of the 3D semiregular mesh. The synchronizing primitive is the distance between the mesh center and salient points in the descending order. The experimental results show the high imperceptibility of the proposed scheme while ensuring a good robustness against a wide range of attacks including smoothing, additive noise, element reordering, similarity transformations, etc.

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Lee, Hyo Jung, Geuk Lee, and Young Mi Kwon. "Schemes for Indoor Network Synchronization in UWB Positioning." Key Engineering Materials 277-279 (January 2005): 233–41. http://dx.doi.org/10.4028/www.scientific.net/kem.277-279.233.

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Location Positioning is a major technology for ubiquitous computing. A research on Location Positioning using UWB is ongoing. In order to construct an indoor location network, synchronization of base stations is very important. NTP is popularly used as a clock synchronization protocol ranging from LAN to WAN. The Master-Slave scheme, however, is the simplest method for synchronizing an indoor network that uses UWB. In this paper, we compare and analyze the NTP and Master-Slave schemes according to the statistical channel model for an indoor multi-path propagation environment. Error ranges are calculated at various circumstances such as when the indoor network expands from one primary base station to several base stations. In particular, we compare the correctness of the NTP and Master-Slave synchronization methods. We have found that NTP is a more reasonable synchronization protocol in UWB positioning.

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SU, JUHNG-PERNG, and CHUN-CHIEH WANG. "SYNCHRONIZING CASCADE-CONNECTED CHAOTIC SYSTEMS WITH UNCERTAINTIES AND BREAKING CHAOTIC CRYPTOSYSTEMS VIA A NOVEL ADAPTIVE CONTROL SCHEME." International Journal of Bifurcation and Chaos 15, no. 08 (August 2005): 2457–68. http://dx.doi.org/10.1142/s0218127405013411.

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This paper deals with synchronization problems of chaotic systems by applying a new adaptive variable structure control (AVSC) scheme. On the basis of Lyapunov synthesis method and Barbalat's Lemma, the proposed control law is shown to render the slave system asymptotically synchronized with the master system even though the parameters of the master system are unknown. A robust adaptive control scheme is presented to guarantee the robustness of the synchronization against bounded disturbances. Even for the case that the slave and master chaotic systems are not of the same type, the proposed AVSC may approximately null the synchronization error. We used an uncertain Rössler system, an uncertain Chua's circuit and an uncertain Duffing–Holmes oscillator as examples to illustrate the controller design. Both theoretical and simulation results strongly suggest that chaotic cryptosystems could be broken by the proposed adaptive control method. This reveals the fact that chaos-based cryptosystems may fail to achieve the secure communication.

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MILANOVIĆ, VELJKO, and MONA E. ZAGHLOUL. "SYNCHRONIZATION OF CHAOTIC NEURAL NETWORKS AND APPLICATIONS TO COMMUNICATIONS." International Journal of Bifurcation and Chaos 06, no. 12b (December 1996): 2571–85. http://dx.doi.org/10.1142/s0218127496001648.

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Methods for synchronizing discrete time chaotic neural networks are presented with possible applications in single- or multi-user private communications. Chaotic neurons, characterized with a piecewise-linear N-shaped transfer function, are connected into Hopfield-like networks with parameters set for chaos. The networks are used as transmitter and receiver circuits in chaotic communications schemes. The first algorithm is a modification of simple chaotic masking which makes synchronization robust and insensitive to the perturbation from the added information signal. A mathematical proof and simulation results of the scheme are shown for small networks. We have verified the method experimentally, using single- and two-neuron circuits. The second algorithm utilizes modulation of the transmitting chaotic network by a binary bit stream and detection of the corresponding synchronization error at the receiver. A method for multiple-user chaotic communication is also presented, utilizing chaotic neurons and spread spectrum techniques. The effects of additive noise in the proposed communication schemes are considered and simulated. Synchronization of larger networks and possible applications are also discussed.

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Bazylev, V. A., S. A. Mikheev, and A. V. Tulupov. "About a FEL scheme with a synchronizing magnetic field for beam cooling and operation with hot beams." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 341, no. 1-3 (March 1994): ABS73. http://dx.doi.org/10.1016/0168-9002(94)90451-0.

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VEPA, RANJAN. "ACTIVE–PASSIVE DECOMPOSITION WITH APPLICATION TO ARRAYS OF CHAOTIC SYSTEMS." International Journal of Bifurcation and Chaos 11, no. 06 (June 2001): 1593–606. http://dx.doi.org/10.1142/s0218127401002882.

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In this paper an alternate method of Active–Passive Decomposition of chaotic systems based on the notion of passivity is presented. The concepts of model following in control theory are applied to show how such a decomposition is useful in achieving synchronization. Besides the fact that model following control may be implemented in a whole class of systems, it is also the basis for designing adaptive systems where the convergence of the scheme is often proved by the use of passivity concepts. The method is shown to be extremely useful in synchronizing passively coupled chaotic systems in general and arrays of coupled but identical controlled chaotic systems in particular.

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Chen, Zhenping, Yourui Huang, Zheng Wang, and Feng Tao. "Time synchronization for long-chain-type wireless sensor networks." International Journal of Distributed Sensor Networks 14, no. 9 (September 2018): 155014771879782. http://dx.doi.org/10.1177/1550147718797824.

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In view of the requirement on time synchronization for a kind of typical wireless sensor networks with long-chain-type topologies, taking into account the three-dimensional network model currently used by the localization algorithms, one feasible time synchronization algorithm is proposed in this article. Under the three-dimensional topology, nodes in the wireless sensor networks are divided into three kinds: the sensing nodes, the relay nodes, and the measured nodes. By analyzing the distribution characteristics of these three kinds of nodes, with the introduction of the pairwise broadcast synchronization and the series multi-hop synchronization protocol, the estimation of the clock offset and the clock skew of all the nodes in the wireless sensor networks are performed by virtue of the joint maximum likelihood and the least-squares method, thus the time synchronization of the wireless sensor networks with long-chain-type topology is solved. Moreover, the sink node evaluates the network periodically and adjusts the synchronizing cycle based on the difference between the network synchronization error and the given synchronization accuracy. The feasibility and effectiveness of this scheme are analyzed by simulations from the synchronization accuracy, the number of synchronization message, and the synchronizing cycle points of view.

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Obzherin, Yuriy E., and Stanislav M. Sidorov. "Semi-Markov Model and Phase-Merging Scheme of a Multi-Component System with the Group Instantly Replenished Time Reserve." International Journal of Reliability, Quality and Safety Engineering 26, no. 03 (May 7, 2019): 1950014. http://dx.doi.org/10.1142/s0218539319500141.

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Time redundancy is a method of increasing the reliability and efficiency of the operation of systems for various purposes. A system with time redundancy provides additional time (a time reserve) for restoring characteristics and synchronizing the work of its individual elements. Time reservation is used in production, energy, gas transportation, information, ergonomic systems and some others. In this paper, based on the theory of semi-Markov processes with a common phase space of states, a semi-Markov model of a multicomponent system with a group instantly replenished time reserve is constructed. The reliability characteristics of the system are determined. To approximate the probability and the average time of failure-free operation of the system in conditions of high reliability, asymptotic phase-merging scheme algorithms are used.

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Chaudhari, Sandeep C., Yashwant Gupta, Ajith Kumar, Navnath D. Shinde, Sweta Gupta, and Ajay Vishwakarma. "Reducing Effects of Cross-Talk in a Radio Telescope Using Walsh Modulation." Journal of Astronomical Instrumentation 06, no. 01 (March 2017): 1641017. http://dx.doi.org/10.1142/s2251171716410178.

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Traditional Walsh technique is used to eliminate cross-talk in a array of radio telescope where achieving synchronization between modulator and demodulator without compromising sensitivity is a real challenge. The paper describes a novel approach named Walsh Delay Hunting (WDH) to synchronize independently running modulator and demodulator with no additional hardware. This approach is unique and can easily be implemented in any existing radio telescope with minimal changes, thus by putting Walsh modulator at telescope and demodulation can be done in digital back-end. The scheme greatly reduces antenna electronics and overhead of sending synchronizing Walsh start pulse back to center station and vice versa. The paper describes WDH method and its feasibility study for Giant Meterwave Radio Telescope (GMRT) along with test results. The modulator is a low cost CPLD-based module and demodulation is done in a Reconfigurable Open Architecture Computing Hardware (ROACH)-based digitizer and packetizer. The scheme requires noise injection facility before modulator, which GMRT has for antenna calibration.

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Gomez-Ricardez, Juan Jose, and Jose Juan Garcia-Hernandez. "A Low Distortion Audio Self-Recovery Algorithm Robust to Discordant Size Content Replacement Attack." Computers 10, no. 7 (July 14, 2021): 87. http://dx.doi.org/10.3390/computers10070087.

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Although the development of watermarking techniques has enabled designers to tackle normal processing attacks (e.g., amplitude scaling, noise addition, re-compression), robustness against malicious attacks remains a challenge. The discordant size content replacement attack is an attack against watermarking schemes which performs content replacement that increases or reduces the number of samples in the signal. This attack modifies the content and length of the signal, as well as desynchronizes the position of the watermark and its removal. In this paper, a source-channel coding approach for protecting an audio signal against this attack was applied. Before applying the source-channel encoding, a decimation technique was performed to reduce by one-half the number of samples in the original signal. This technique allowed compressing at a bit rate of 64 kbps and obtaining a watermarked audio signal with an excellent quality scale. In the watermark restoration, an interpolation was applied after the source-channel decoding to recover the content and the length. The procedure of decimation–interpolation was taken because it is a linear and time-invariant operation and is useful in digital audio. A synchronization strategy was designed to detect the positions where the number of samples in the signal was increased or reduced. The restoration ability of the proposed scheme was tested with a mathematical model of the discordant size content replacement attack. The attack model confirmed that it is necessary to design a synchronizing strategy to correctly extract the watermark and to recover the tampered signal. Experimental results show that the scheme has better restoration ability than state-of-the-art schemes. The scheme was able to restore a tampered area of around 20% with very good quality, and up to 58.3% with acceptable quality. The robustness against the discordant size content replacement attack was achieved with a transparency threshold above −2.

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Hussain, Ghayyur, Muhammad Siddique, Muhammad Majid Hussain, Muhammad Tahir Hassan, and Naeem Aslam. "Synchronization of N-Non-linear Slave Systems with Master System Using Non-Adaptive and Adaptive Coupled Observers." Energies 14, no. 11 (May 29, 2021): 3190. http://dx.doi.org/10.3390/en14113190.

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Synchronization of N-slave chaotic systems with a master system is a challenging task, particularly in recent times. In this paper, a novel methodology is proposed for synchronizing the N number of slave systems with a master system. The proposed methodology is based on coupled adaptive synchronous observers. The difference between the corresponding states of master and slave systems is converged to the origin by means of a novel feedback control scheme to achieve synchronization between the master and slave systems. The efficacy of the proposed methodology is verified through a simulation of FitzHugh–Nagumo non-linear systems in MATLAB. The simulation results validate and prove claims, and these systems are successfully synchronized by CCS and CCAS observer-based control.

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Tan, Yifei, Wenhe Yang, Kohtaroh Yoshida, and Soemon Takakuwa. "Application of IoT-Aided Simulation to Manufacturing Systems in Cyber-Physical System." Machines 7, no. 1 (January 3, 2019): 2. http://dx.doi.org/10.3390/machines7010002.

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With the rapid development of mobile and wireless networking technologies, data has become more ubiquitous and the IoT (Internet of Things) is attracting much attention due to high expectations for enabling innovative service, efficiency, and productivity improvement. In next-generation manufacturing, the digital twin (DT) has been proposed as a new concept and simulation tool for collecting and synchronizing real-world information in real time in cyber space to cope with the challenges of smart factories. Although the DT is considered a challenging technology, it is still at the conceptual stage and only a few studies have specifically discussed methods for its construction and implementation. In this study, we first explain the concept of DT and important issues involved in developing it within an IoT-aided manufacturing environment. Then, we propose a DT construction framework and scheme for inputting data derived from the IoT into a simulation model. Finally, we describe how we verify the effectiveness of the proposed framework and scheme, by constructing a DT-oriented simulation model for an IoT-aided manufacturing system.

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Chen, Wei, Yifei Wu, Renhui Du, Qingwei Chen, and Xiaobei Wu. "Speed Tracking and Synchronization of a Dual-Motor System via Second Order Sliding Mode Control." Mathematical Problems in Engineering 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/919837.

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Dual-motor systems have been widely used in industrial applications, and speed synchronization of the motors can always be deteriorated by system parameter uncertainties and load torque perturbations. In this paper, a new robust control strategy for the dual-motor systems is developed by incorporating second order sliding mode control (2-SMC) techniques. The strategy is to design chatting-free control laws to stabilize speed tracking of each motor while synchronizing their velocity. In the proposed scheme, firstly, speed controller for a single motor is designed to eliminate the effects of system parameter variations and load torque perturbations. Secondly, a cross-coupled architecture based synchronous controller is designed to reduce speed error of the motors caused by characteristic inconsistency and unbalanced load torque. Stability of the closed loop system is analyzed by Lyapunov theory; it is proven that both speed tracking errors and synchronous error can converge to zero. Finally, experiments are performed to examine the effectiveness of the developed controllers. Experimental results will show the good performance of the proposed control scheme.

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Misbahuddin, Syed, and Mohammed Talal Simsim. "4 Maximum Likelihood Decoder for Variable Length Codes." Sir Syed Research Journal of Engineering & Technology 1, no. 1 (December 20, 2012): 5. http://dx.doi.org/10.33317/ssurj.v1i1.69.

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Variable Length Codes (VLC) are used to transfer same amount of digital information in relatively short period of time. In variable length coding, the characters with higher probability of occurrence are assigned shorter bits sequence and the characters with less probability of occurrence are assigned relatively longer bits sequence. However, due to variable length nature of codes, the decoding circuitry at the receiving end loses the synchronization due to single or multiple bit inversions. This typically happens when data is transmitted through a Binary Symmetric Channel (BSC). This paper investigates synchronizing scheme to control the error propagation due to single or multiple bit inversions through BSC. The hardware implementation of the proposed algorithm has been presented using a hardware description language. The functional level simulation of the implementation is discussed to test the proposed algorithm.

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Misbahuddin, Syed, and Mohammed Talal Simsim. "Maximum Likelihood Decoder for Variable Length Codes." Sir Syed University Research Journal of Engineering & Technology 2, no. 1 (December 20, 2012): 5. http://dx.doi.org/10.33317/ssurj.v2i1.69.

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Variable Length Codes (VLC) are used to transfer same amount of digital information in relatively short period of time. In variable length coding, the characters with higher probability of occurrence are assigned shorter bits sequence and the characters with less probability of occurrence are assigned relatively longer bits sequence. However, due to variable length nature of codes, the decoding circuitry at the receiving end loses the synchronization due to single or multiple bit inversions. This typically happens when data is transmitted through a Binary Symmetric Channel (BSC). This paper investigates synchronizing scheme to control the error propagation due to single or multiple bit inversions through BSC. The hardware implementation of the proposed algorithm has been presented using a hardware description language. The functional level simulation of the implementation is discussed to test the proposed algorithm.

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Buscarino, Arturo, Luigi Fortuna, and Mattia Frasca. "Experimental separation of chaotic signals through synchronization." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 366, no. 1865 (August 13, 2007): 569–77. http://dx.doi.org/10.1098/rsta.2007.2111.

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In this paper using a negative feedback scheme we study the problem of synchronizing two systems (each of them made of n independent chaotic circuits) through the transmission of a unique signal (i.e. a scalar variable). To find the appropriate values of the feedback gains, an approach based on the design of an asymptotic observer leading to a set of linear matrix inequalities is used for piecewise linear systems, while for systems with continuous nonlinearities a master stability function approach is adopted. Numerical results showing the suitability of the approach are reported. Furthermore, the experiment showing separation and synchronization of two pairs of chaotic circuits is discussed. Despite the presence of parameter mismatches, separation and synchronization of the two systems can be achieved. This is an experimental demonstration of the successful possibility of multiplexing two (or more) chaotic signals in the same channel.

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Chang, Yong-Nong, Shun-Yu Chan, and Hung-Liang Cheng. "A Single-Stage High-Power Factor Converter with Synchronized Self-Excited Technique for LED Lighting." Applied Sciences 8, no. 8 (August 20, 2018): 1408. http://dx.doi.org/10.3390/app8081408.

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This paper proposes a single-stage, high power-factor light-emitting diode (LED) driver with a self-excited control scheme for the power switches. The self-excited mechanism is accomplished by fetching the driving voltages from a center-tapped transformer. The frequency of the driving voltages is exactly the same as the resonant frequency of the resonant converter, thus synchronizing the resonant frequency with the switching frequency and achieving zero-voltage switching (ZVS) and zero-current switching (ZCS) of power switches. The circuit topology is mainly composed of a half-bridge LC resonant converter, along with a boost-type power-factor corrector (PFC) to fulfill the single-stage structure, meaning that the presented LED driver possesses high power-factor features and low switching loss. Finally, a 40 W prototype circuit is implemented and tested, and the experimental results exhibit a satisfactory performance.

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Santos, Márcia Adriana Carvalho dos, Mailson Monteiro do Rego, Manoel Abilio de Queiroz, Bárbara França Dantas, and Wagner Campos Otoni. "SYNCHRONIZING THE in vitro GERMINATION OF Psidium guineense Sw. SEEDS BY MEANS OF OSMOTIC PRIMING." Revista Árvore 40, no. 4 (August 2016): 649–60. http://dx.doi.org/10.1590/0100-67622016000400008.

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ABSTRACT The Brazilian guava (Psidium guineense Swartz) is seed-propagated and, being native to the Caatinga biome, may frequently have uneven germination.Thus, we aimed to evaluate the synchronization of the in vitro seed germination of three accessions of the Brazilian guava, using water, polyethyleneglycol (PEG 6000), and potassium nitrate (KNO3) at different potentials and times of osmotic priming. Seeds from three accessions of the Brazilian guava (Y85, Y93,and Y97) from the UNEB/BA Germplasm Active Bank were subjected to the following pretreatments: -0.6, -1.0, -1.4, and -1,8 MPa PEG 6000; 10 and 20% KNO3 for 24h; 10 and 20% KNO3 for 48h; water for 24 and 48h; and non-primed seeds as the control. The experimental design was therefore a 10x3+1 factorial scheme. We assessed the germination percentage (G), mean germination time (MGT), germination speed (GS), and germination speed index (GSI). Data was subjected to analysis of variance followed by a means test (Duncan at 5% probability) and regression. There was interaction between the priming treatments and accessions for all evaluated features, except G. PEG 6000 decreased the MGT (from 6 to 8 days) and increased GS and GSI of seeds from all three accessions at potentials -1.0 to -1.5 MPa.Water-priming had a positive effect on MGT, GS, and GSI of accession Y85 seeds. KNO3 negatively affected germination of seeds from all three accessions. Thereby, we could synchronize seed germination of accessions Y85 and Y97 with PEG 6000.

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Sun, Tao, and Wei-yang Qin. "Obtaining Dynamic Responses of Rotor from a Synchronizing Derived System Driven by Responses of Some Elastic Supports." International Journal of Turbo & Jet-Engines 38, no. 1 (November 3, 2017): 31–40. http://dx.doi.org/10.1515/tjj-2017-0045.

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Abstract For rotating machinery, during its running, direct measuring for vibration of rotating components is very difficult. To overcome this defect, we presented a scheme to obtain dynamical responses of a rotor system by synchronizing with a derived virtual system. For a rotor system, a derived system is established, of which some parts are designed to be incorporated with the measurable part of the original rotor system. Then it is proved theoretically that the two systems can reach synchronization, which implies the two systems’ responses are identical. We hope that the derived virtual system can exhibit the dynamical response of the original system, especially in the case of faults occurring. Thus in simulations, first we add a base disturbance to the rotor system. The simulation results reveal that the derived system can reach synchronization with the disturbed rotor quiet well and thus show the disturbed response. Then we assume that there occurs bolt looseness in the rotor support, the simulation shows that the derived system can maintain synchronization with the fault rotor. Thus we can obtain the response of the rotor from the derived system, even the angle response difficult to measure in practice.

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Weidner, H., and R. E. Peale. "Event-Locked Time-Resolved Fourier Spectroscopy." Applied Spectroscopy 51, no. 8 (August 1997): 1106–12. http://dx.doi.org/10.1366/0003702971941917.

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A low-cost method of adding time-resolving capability to commercial Fourier transform spectrometers with a continuously scanning Michelson interferometer has been developed. This method is specifically designed to eliminate noise and artifacts caused by mirror-speed variations in the interferometer. The method exists of two parts: (1) a novel timing scheme for synchronizing the transient events under study and the digitizing of the interferogram and (2) a mathematical algorithm for extracting the spectral information from the recorded data. The novel timing scheme is a modification of the well-known interleaved, or stroboscopic, method. It achieves the same timing accuracy, signal-to-noise ratio, and freedom from artifacts as step-scan time-resolving Fourier spectrometers by locking the sampling of the interferogram to a stable time base rather than to the occurrences of the HeNe fringes. The necessary pathlength-difference information at which samples are taken is obtained from a record of the mirror speed. The resulting interferograms with uneven pathlength-difference spacings are transformed into wavenumber space by least-squares fits of periodic functions. Spectra from the far-infrared to the upper visible at resolutions up to 0.2 cm−1 are used to demonstrate the utility of this method.

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Manoj, S., S. Pradeep Kumar, and N. Ashok Babu. "Automatic Synchronverter: Inverter Lacking a Devoted Synchronization Unit." International Journal of Engineering & Technology 7, no. 2.25 (May 3, 2018): 20. http://dx.doi.org/10.14419/ijet.v7i2.25.12359.

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The design of self-synchronized synchronverter is made by removing the keen synchronization unit. Synchronization with the grid takes place before connection and it will track the grid frequency after connection. Like the original synchronverter it functions in various modes to deliver the grid frequency as the reference frequency. The functions of frequency regulation, voltage regulation, real and reactive power control are maintained. Moreover, it can share the real power and reactive power accurately. Distributed energy sources delivers the major contribution to the power system operation. Generally the renewable sources are non-linear and uncontainable. Majority of renewable energy sources were associated to power systems through dc/ac converters. For this kind of application synchronizing the inverter with the grid is necessary before and after the connections to be made. It is one of the biggest challenges. So synchronverter is designed to deliver a scheme for power systems to regulate the renewable energy connected to the grid and enables smart grid integration.

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Yang, Tao, and Leon O. Chua. "Chaotic Digital Code-Division Multiple Access (CDMA) Communication Systems." International Journal of Bifurcation and Chaos 07, no. 12 (December 1997): 2789–805. http://dx.doi.org/10.1142/s0218127497001886.

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In this paper, the structure, principle and framework of chaotic digital code-division multiple access ((CD)2 MA) communication systems are presented. Unlike the existing CDMA systems, (CD)2MA systems use continuous pseudo-random time series to spread the spectrum of message signal and the spread signal is then directly sent through a channel to the receiver. In this sense, the carrier used in (CD)2MA is a continuous pseudo-random signal instead of a single tone as used in CDMA. We give the statistical properties of the noise-like carriers. In a (CD)2MA system, every mobile station has the same structure and parameters, only different initial conditions are assigned to different mobile stations. Instead of synchronizing two binary pseudo-random sequences as in CDMA systems, we use an impulsive control scheme to synchronize two chaotic systems in (CD)2MA. The simulation results show that the channel capacity of (CD)2MA is twice as large than that of CDMA.

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Journal articles on the topic 'Synchronizing scheme'

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