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A quantum secure direct communication scheme based on single particles is proposed. In our scheme, we define a new Y-basis which is different from the traditional Z-basis and X-basis in BB84. Then we use the Pauli I operation and Z operation to encode the secret message into the single particles. Compared to Pauli X operation and Pauli Y operation, the merit of Pauli Z operation is that it only rotates the phase of the particle and not change the polarization of the particle, so its implementation will be easier than that of Pauli X operation or Pauli Y operation. Therefore, our scheme will be more practical than the existing schemes. [ABSTRACT FROM AUTHOR]

This work investigates the tracking consensus problem of multiagent systems over directed networks, where the control gains follow certain volatile patterns. Some event-based consensus protocols are formulated so as to reduce the redundant execution of control. By using an extended differential inequality with a time-dependent coefficient, criteria for tracking consensus under time- and state-dependent triggering conditions are constructed, respectively. It is proved that the time average of the control gain, together with the agent dynamics, network topology, and triggering conditions, governs the consensus despite the fluctuation of control gain. The derived theorem can be utilized to ensure consensus with intermittent strategies aiming to lessen the burden in communications, including aperiodic on–off control with periodic perturbation and pulse-modulated on–off control. Unlike existing works, the requirement of a positive lower bound of control ratios is removed and, thus, a wide range of control gain patterns is possible, signifying higher flexibility in intermittent policy design. Finally, numerical examples are provided to further illustrate the theoretical results. [ABSTRACT FROM AUTHOR]

A two-stage stochastic programming model is established to minimize EV's expected total journey time under stochastic traffic conditions, by jointly optimizing the allocation of chargers and the distribution of EV flows. Based on sample average approximation, a feasible deterministic equivalent of the original stochastic problem is obtained. Then, a hybrid solution method, composing of a Tabu-based search and sequential quadratic programming (SQP), is proposed. The Tabu heuristic manages the charger allocation problem, where each solution candidate undergoes a second-stage EV flow optimization. SQP is applied to optimally distribute the EV flows, which is proved to be a convex problem. Extensive simulations are carried out using the eastern Massachusetts highway network. Results show that the proposed algorithm outperforms existing approaches by finding high-quality charger allocation and optimal flow distribution policies under different traffic conditions. Additionally, the two-stage model designates charging resource sufficiency by statistically estimating a lower bound for the number of chargers to allocate, which in practice helps to prevent over-investment on charging resources. [ABSTRACT FROM AUTHOR]

This paper is devoted to the consensus problem of networked nonlinear agents with multiple self-delays and time-varying coupling. We first establish a generalized Halanay’s inequality based on comparison theorem, and then convert the consensus problem into a stability problem of retarded differential equation with time-varying coefficients, from which sufficient conditions for consensus are derived. Our results manifest that the time-average of coupling strength over intervals of certain length, together with the underlying topology and the values of self-delays, plays a crucial role in guaranteeing consensus. Based on the theoretical analysis, an estimation of the largest admissible delay is also available. This paper provides a general framework for achieving consensus in agents with time-varying coupling, such as coupling with external perturbations, intermittent control in on–off fashion, or pulse-modulated coupling strength, etc. Furthermore, useful criteria are given for various applications which have also been verified with numerical simulations. [ABSTRACT FROM AUTHOR]

In this paper, the second-order leader-following consensus of coupled nonlinear agents with intermittent control is investigated. A subset of followers is pinned while it is assumed that the underlying digraph contains a directed spanning tree with the leader node as the root. By using multiple Lyapunov functions method and algebraic graph theory, it is proved that second-order consensus is guaranteed by choosing the control and rest durations appropriately in each time interval. This result provides high flexibility in control gain design, allowing multiple switching with different gains in arbitrarily-chosen time intervals. As a result, it not only encompasses many existing intermittent control schemes but can also manage practical situations, such as recovery from occasional control failures. Numerical simulations are also given to demonstrate our theoretical results. [ABSTRACT FROM AUTHOR]

A quantum key distribution protocol with single-particle and Bell state is proposed, in which one player Alice sends the states from some special single-particles and Bell states, the other player Bob measures these states in the single-particle basis or Bell basis, and then establish their secret key. Through combining the single-particle and Bell state novelly, the error rate of eavesdropping in our protocol can be increased up to 3 8 . Compared to BB84, our protocol can get higher secure key rate in practice. [ABSTRACT FROM AUTHOR]

A hierarchical quantum secret sharing scheme is proposed, for which participants are divided into multiple layers. In this scheme, the number of participants and the shared secrets can be different for layers. The shared secret of a layer can only be recovered by the cooperation of all the participants at that layer. Moreover, each participant is able to obtain the shared secrets at lower layers, but not those at higher layers. The design is based on a special high-dimensional entangled state, in which the particles have different dimensions and can be set as subtle values to satisfy the hierarchical requirement. The correctness and security of the proposed scheme are analyzed. As compared to existing quantum secret sharing schemes, it possesses distinct features which are demanded by some specified scenarios. [ABSTRACT FROM AUTHOR]

A public-key quantum signature (QS) scheme is proposed, in which the phase shift is the private key and the quantum state after the phase shift operation is the public key. The signatory uses the private key to encode the quantum state, and uses the Bell measurement to generate the signature. The receiver performs the unitary operation according to the signature, and then compares the quantum state with the public key to verify the signature. Our scheme does not need a trusted arbitrator, and the signature can be verified by the receiver publicly. Compared to the existing arbitrated QS scheme, our scheme will be more practical. [ABSTRACT FROM AUTHOR]

Quantum group signature is an important branch of quantum signature. Most of the existing quantum group signature schemes require that all the signatories must be present to generate a valid signature, and this property may limit their application in practice. In this paper, we will propose a quantum (t, n) threshold group signature scheme. In our scheme, n signatories compose a group, and any t out of these n signatories can generate a valid signature on behalf of the group. The t signatories use the quantum-controlled-not operations to expand the quantum message into t-particle entangled states, and then use the entanglement swapping to transmit the quantum message to the receiver. The receiver performs the single-particle measurements and unitary operations to recover the initial quantum message, and then verifies the signature with the help of the arbitrator. Compared to the existing quantum group signature schemes, our (t, n) threshold scheme will be more flexible in practice. [ABSTRACT FROM AUTHOR]

For the benefit of global environmental preservation, electric vehicles (EVs) have been gradually accepted by people in the past few years. However, the technical problem of limited drivable range and long charging duration is still a major hurdle for the popularization of EVs, especially for commercial usage. In this paper, a dynamic electric vehicle routing problem (D-EVRP) model is designed for planning the itinerary for goods delivery by the utilization of EVs in logistics industry. To reflect the real situation, the D-EVRP considers a time-dependent stochastic traffic condition and captures the discharging/charging pattern of an EV using an analytical battery model. Its aim is to minimize the overall service duration, subject to a variety of the state-of-art constraints common in EV routing problems. Furthermore, to address the D-EVRP, a hybrid rollout algorithm (HRA), which incorporates a dedicated pre-planning strategy and a rollout algorithm, is also proposed. The effectiveness of the HRA and benefits of incorporating the analytical battery model are justified by extensive simulations using the real-world D-EVRP instances. [ABSTRACT FROM AUTHOR]

A three-party quantum secret sharing scheme is proposed, in which the dealer uses the d-dimensional Bell state to distribute the secret, the participants perform the single-particle measurements to get their shares, and the dealer performs the Bell-basis measurements to check the eavesdropping. The main merit of our scheme is that the participants only need to measure the particles in one basis. Compared to the existing schemes in which the participants need to measure the particles in two bases, our scheme will be more practical. [ABSTRACT FROM AUTHOR]

This brief addresses the consensus problem of a group of agents coupled via nonlinear locally passive functions over a time-varying network. A consensus protocol is designed which is solely dependent on an agent’s own instantaneous state and the states broadcasted from its neighbors. A time-dependent triggering condition is defined to govern the broadcasting of one’s state to all its neighbors. Information exchange only occurs when the triggering condition is met, as a result, communication overhead can be greatly reduced. It is mathematically proved that consensus is reachable and Zeno behavior is excluded if the union of the underlying graphs over any time interval of certain length admits a directed spanning tree. The proposal is applicable for various kinds of networks, such as continuously time-varying network, switching network, blinking network, and its effectiveness is confirmed with numerical examples. [ABSTRACT FROM AUTHOR]

In this brief, a multi-carrier differential chaos shift keying system capable of mitigating channel noise is proposed. In this system, subcarriers are allocated to the reference and data signals in an optimal way, while noise reduction is achieved through reference diversity. To verify its performance, the bit error rate of the proposed system over multipath Rayleigh fading channels is derived, together with a detailed discussion about the determination of the optimal number of reference-carrying subcarriers. Extensive simulations are carried out for performance evaluation, which are further compared to other state-of-the-art systems. Results confirm the superior bit error rate performance of the proposed system, which has only small loss in energy and spectral efficiencies. [ABSTRACT FROM AUTHOR]

A multiparty to multiparty quantum secret sharing (QSS) scheme is proposed. In our scheme, the participants can transmit their shared secret to other participants. The old participants and the new participants all can keep their shares secret. The main operations in our scheme are the quantum-logic-gate transformations and the single-particle measurements, which can be realized easily within the present technology. [ABSTRACT FROM AUTHOR]

The traditional quantum secret sharing does not succeed in the presence of rational participants. A rational participant's motivation is to maximize his utility, and will try to get the secret alone. Therefore, in the reconstruction, no rational participant will send his share to others. To tackle with this problem, we propose a rational quantum secret sharing scheme in this paper. We adopt the game theory to analyze the behavior of rational participants and design a protocol to prevent them from deviating from the protocol. As proved, the rational participants can gain their maximal utilities when they perform the protocol faithfully, and the Nash equilibrium of the protocol is achieved. Compared to the traditional quantum secret sharing schemes, our scheme is fairer and more robust in practice. [ABSTRACT FROM AUTHOR]

Naming game simulates the evolution of vocabulary in a population of agents. Through pairwise interactions in the games, agents acquire a set of vocabulary in their memory for object naming. The existing model confines to a one-to-one mapping between a name and an object. Focus is usually put onto name consensus in the population rather than knowledge learning in agents, and hence simple learning model is usually adopted. However, the cognition system of human being is much more complex and knowledge is usually presented in a complicated form. Therefore, in this work, we extend the agent learning model and design a new game to incorporate domain learning, which is essential for more complicated form of knowledge. In particular, we demonstrate the evolution of color categorization and naming in a population of agents. We incorporate the human perceptive model into the agents and introduce two new concepts, namely subjective perception and subliminal stimulation, in domain learning. Simulation results show that, even without any supervision or pre-requisition, a consensus of a color naming system can be reached in a population solely via the interactions. Our work confirms the importance of society interactions in color categorization, which is a long debate topic in human cognition. Moreover, our work also demonstrates the possibility of cognitive system development in autonomous intelligent agents. [ABSTRACT FROM AUTHOR]

In this paper, the effect of the parameter switching (PS) algorithm in a fractional order chaotic circuit is investigated both in simulation and experiment. The Chen system of fractional order is focused and realized in an electronic circuit. By designing a switching circuit, the PS algorithm is implemented and it is the first time, the paradoxical 'Chaos Chaos Order' is presented in an electronic circuit. Both the simulation and experimental results confirm that the obtained attractor under switching approximates the attractor of the time-averaged model. Some important design issues for the circuitry realization of the PS scheme are pointed out. Finally, our work confirms the practical usage of PS algorithm in potential applications such as attractor synthesis and chaos control. [ABSTRACT FROM AUTHOR]

In this paper, we aim to identify a directed complex network with optimal controllability, for which pinning control is to be applied. Since the controllability of a network can be reflected by the smallest nonzero eigenvalue of a matrix related to its topology, an optimal network design problem is formulated based on the maximization of this eigenvalue. To better consider the practical reality, constraints on node degree sequence are specified. Based on the derived bounds of the eigenvalue, an effective rewiring scheme is designed and solutions close to or equal to the upper bound are obtained. Finally, the relationship between network characteristics and controllability is studied. Through complexity analysis, it is concluded that the network with high controllability should possess two properties, i.e. nodes with high out-degree for pinning and other nodes with uniform degree distribution. [ABSTRACT FROM AUTHOR]

In this paper, a modified degree-based strategy is proposed for pinning control of complex networks under constrained control capacity. Limited by the total control strength, the pinning strategy design problem is reconsidered as a constrained optimization problem. To provide a fast and effective solution, a decrease-and-conquer approach has been designed to assign the best control strengths to the pinned highest-degree nodes. Simulation results have demonstrated that the obtained strategy provides an outperformed control effect on various kinds of complex networks, as compared with strategies derived from degree, betweenness or closeness using evenly-distributed control strength. [ABSTRACT FROM AUTHOR]

Recently, the identification of biological neural networks has been reformulated as an optimization problem based on a framework of adaptive synchronization. In this paper, four different optimization algorithms, including genetic algorithm, jumping gene genetic algorithm (JGGA), tabu search, and simulated annealing, have been applied for this optimization problem. Based on the simulation results, their performances are compared, and it is concluded that JGGA can outperform the other three methods in term of minimizing the synchronization and parameter estimation errors. [ABSTRACT FROM AUTHOR]

Lorenz system, as the first classical chaotic system, has been intensively investigated over the last four decades. Based on the sawtooth wave function, this paper initiates a novel approach for generating multi-wing butterfly chaotic attractors from the generalized first and second kinds of Lorenz-type systems. Compared with the traditional ring-shaped multi-scroll Lorenz chaotic attractors, the proposed multi-wing butterfly chaotic attractors are much easier to be designed and implemented by analog circuits. The dynamical behaviors of these multi-wing butterfly chaotic systems are further studied. Theoretical analysis shows that every index-2 saddle-focus equilibrium corresponds to a unique wing in the butterfly attractors. Finally, a module-based unified circuit diagram is constructed for realizing various multi-wing butterfly attractors. It should be especially pointed out that this is the first time in the literature that a maximal 10-wing butterfly chaotic attractor is experimentally verified by analog circuits. [ABSTRACT FROM AUTHOR]

In this paper, a modulated optical injection system is proposed. It mainly consists of a semiconductor laser subject to a modulated optical injection. It is known that optical injection will force a laser intensity into high-speed periodic oscillation without modulation, while the oscillation will be locked with weak external modulation. However, the route to chaos in such a system is observed and reported for the first time. It is shown that the generated oscillation frequency shifts away from the external frequency when the modulation amplitude becomes sufficiently large. Due to the nonlinearities of the laser, the frequencies are mixed inside the laser cavity, which causes the dynamics to follow a quasi-periodic route to chaos. In addition, the resultant chaotic signal possesses a larger bandwidth than that attainable with constant optical injection alone. Since the system is capable of generating both narrowband photonic microwave signals with low phase variances and chaotic signals with large bandwidths, it is practically important for Doppler and chaotic lidar applications. [ABSTRACT FROM AUTHOR]

This paper addresses the cryptanalysis of three chaos-based secure communication schemes recently proposed by Yu et al. [2007]. Attacks with adaptive observers designed by the dynamical minimization algorithm are assumed. Considering Kerckhoff's principle, i.e. assuming that the basic structure of a cryptosystem is known but some user-specified parameters remain in secret, it is demonstrated that the covered messages in all these schemes can be estimated and hence their securities are challenged. [ABSTRACT FROM AUTHOR]

This paper proposes a new three-dimensional chaotic generator, for which the nonlinearity is based on sinusoidal function. Based on a practical circuit design for realizing a wide angular range of sinusoidal functions, chaotic attractors with large number of scrolls have been obtained. Different types of attractors are available, governed by the choices of variables used in the sinusoidal function. The design is illustrated with both simulations and experiments. [ABSTRACT FROM AUTHOR]

This paper addresses the cryptanalysis of a secure communication scheme recently proposed by Wu [Chaos 16, 043118 (2006)], where the information signal is modulated into a system parameter of a unified chaotic system. With the Kerckhoff principle, assuming that the structure of the cryptosystem is known, an adaptive observer can be designed to synchronize the targeted system, so that the transmitted information and the user-specific parameters are obtained. The success of adaptive synchronization is mathematically proved with the use of Lyapunov stability theory, based on the original assumption, i.e., the dynamical evolution of the information signal is available. A more practical case, but yet much more difficult, is also considered. As demonstrated with simulations, generalized synchronization is still possible, even if the derivative of the information signal is kept secret. Hence, the message can be coarsely estimated, making the security of the considered system questionable. [ABSTRACT FROM AUTHOR]

This paper carries out a further cryptanalysis of two Lorenz-based masking secure communication systems, which have been recently attacked by a high-pass filter. As demonstrated with our simulations, high-pass filter attack works well only when the covered information signal is monotonic. However, with an adaptive observer, it is still possible to coarsely obtain the information signal and correctly identify the system user-defined parameters if a multitonic information signal is transmitted, making the security of these two systems questionable. [ABSTRACT FROM AUTHOR]

This paper explores the generation of n- and n × m-wing Lorenz-type attractors from a modified Shimizu-Morioka system. The basic idea is to increase the number of index-2 equilibrium points by introducing a multisegment quadratic function and a stair function in the 2-D state-space of the system. The design is verified by both simulation and experiment, where multiwing attractors over a grid can be clearly observed. [ABSTRACT FROM AUTHOR]

Random number generators are widely used in different applications. However, it is difficult to obtain a good random number generator in low precision and resource constrained system, such as an eight-bit micro-controller system which is still commonly used in industrial and consumer markets. This paper provides a practical solution for this problem based on chaotic systems. By the use of a modified Chua's circuit, it is demonstrated that the sampled state, after post-processing by a high-dimensional chaotic map, can be used as a random source even in an eight-bit environment. The randomness of the generated sequence is testified and confirmed by different statistical tests and the up-to-date statistical suite. [ABSTRACT FROM AUTHOR]

In this letter, a three-dimensional continuous-time smooth autonomous system with quadratic nonlinear terms is proposed for generating multiscroll chaotic attractors. Observation of 2 × 2-scroll attractors generated from this kind of system is reported for the first time. The result is confirmed by both numerical simulations and electronic circuit experiments. [ABSTRACT FROM AUTHOR]

In this paper, the generation of n × m-scroll attractors under a Chua-circuit framework is presented. By using a sawtooth function, f1(x), and a staircase function, f2(y), n × m-scroll attractors can be generated and observed from a third-order circuit. Its dynamical behaviors are investigated by means of theoretical analysis as well as numerical simulation. Moreover, two electronic circuits are designed for its realization, and experimental observations of n × m-scroll attractors based on Chua's circuit are reported, for the first time in the literature. [ABSTRACT FROM AUTHOR]

In this paper, a fast chaos-based pseudo-random number generator (PRNG) is proposed for secured communications. In order to achieve fast throughput and facilitate hardware realization, 32-bit fixed point representation and arithmetic are used. Even under such configuration with quantization errors which will make the normal chaos-based PRNG impractical, our scheme can pass all the statistical tests in the up-to-date National Institute of Standards and Technology (NIST) test suite with the output bit rate up to 134 Mbps in a 2.6 GHz Pentium-4 machine. With such a fast PRNG, a stream cipher is hence designed for the application of online secure voice communication system with User Datagram Protocol (UDP). [ABSTRACT FROM AUTHOR]

This paper proposes a general multiscroll Lorenz system family by introducing a novel parameterized nth-order polynomial transformation. Some basic dynamical behaviors of this general multiscroll Lorenz system family are then investigated, including bifurcations, maximum Lyapunov exponents, and parameters regions. Furthermore, the general multiscroll Lorenz attractors are physically verified by using digital signal processors. [ABSTRACT FROM AUTHOR]

In this paper, a chaos-based cryptographic hash function is proposed for message authentication where a fixed length message digest can be generated from any messages with arbitrary length. The compression function in-use is developed according to the diffusion and confusion properties of a novel high-dimensional discrete chaotic map. A symmetric key structure can also be easily embedded based on the high sensitivity to initial conditions and system parameters of the map. As demonstrated in experiments, the throughput of the proposed scheme is about 1.5 times of that with MD5, and the hash value appears randomly without any correlation with the message or the key. [ABSTRACT FROM AUTHOR]

In this letter, a simple nonlinear state feedback controller is designed for generating hyperchaos from a three-dimensional autonomous chaotic system. The hyperchaotic system is not only demonstrated by computer simulations but also verified with bifurcation analysis, and is implemented experimentally via an electronic circuit. [ABSTRACT FROM AUTHOR]

In this paper, a neuron is introduced for chaotifying nonchaotic discrete-time systems with arbitrary dimensions. By modeling the neuron with a hyperbolic tangent activation function, a scalar feedback signal expressed in a linear combination of the neuron outputs is used. Chaos can then be generated from the controlled discrete-time system. The existence of chaos is verified by both theoretical proof and computer simulations. [ABSTRACT FROM AUTHOR]