A novel memristor-based chaotic system with line equilibria and its complex dynamics

Memristor, as a nonlinear element, provides many advantages thanks to its superior properties to design different chaotic circuits. Thus, a novel four-dimensional double-scroll chaotic system with line equilibria as well as two unstable equilibria based on the flux-memristor model is proposed in this paper. The effects of initial values and parameters on the dynamic characteristics of the system are studied in detail by means of phase diagrams, Lyapunov exponent spectrums, bifurcation diagrams, two-parameter bifurcation diagrams and basins of attraction. Besides, a series of complex phenomena in the system, such as sustained chaos, bistability, transient chaos and coexisting attractors are observed, proving that the chaotic system has rich dynamic characteristics. Also, spectral entropy (SE) complexity algorithm and [Formula: see text] complexity algorithm based on structure complexity are adopted to analyze the complexity of the system. Additionally, PSPICE circuit simulation and Micro-Controller Unit (MCU) hardware experiment are carried out to verify the correctness of theoretical analysis and numerical simulation. Finally, the pulse chaos synchronization is achieved from the perspective of maximum Lyapunov exponent, and numerical simulations demonstrate the occurrence of the proposed system and practicability of the pulse synchronization control.

Purchase Planning for Minimum Assortment Goods Given the Uncertainty of Demand

Some retailers (e.g. pharmacies) are responsible for satisfying the demand for the minimum range of goods, which are generally unprofitable. With respect to such goods, the enterprise seeks to satisfy uncertain demand rather than to make profit. We assume that: (a) the vector of demand for goods of the minimum assortment in the planning period lies “between” the demand vectors of several previous periods (is a convex linear combination of these vectors); (b) the smaller the maximum unsatisfied demand (by product groups and possible vectors of demand), the greater is the reliability of meeting the demand. Under these assumptions, we address the problem of allocating a limited procurement budget among commodity groups to meet uncertain demand most reliably. The article shows that this problem is equivalent to finding an optimal strategy by Wald’s criterion in some game with nature and can be reduced to a linear programming problem. Using the problem features, we propose a fast (having quadratic complexity) algorithm for constructing an optimal procurement plan. The model can be used when planning the minimum assortment goods procurement in order to maximize the meeting demand reliability, achievable within the allocated budget. As far as we know, such a formulation of the problem has not been studied in the previous literature.

A Graceful Labeling of Square of Path Graph with Quadratic Complexity Algorithm

A method for relaxed graceful labeling of P2n graphs is presented together with an algorithm designed for labeling these graphs. Graceful labeling is achieved by relaxing the range to 2m and perform the labeling using an algorithm with quadratic complexity (O(n2)). The algorithm can be used for labeling any P2n graph with n ≥ 3, as far as the machine can handle the size of the problem.

The Shortest Duration Constrained Hidden Markov Model: Data denoise and forecast optimization on the country-product matrix for the Fitness-Complexity Algorithm

The Economic Fitness Index describes industrial completeness and comprehensively reflects product diversification with competitiveness and product complexity in production globalization. The Fitness-Complexity Algorithm offers a scientific approach to predicting GDP and obtains fruitful results. As a recursion algorithm, the non-linear iteration processes give novel insights into product complexity and country fitness without noise data. However, the Country-Product Matrix and Revealed Comparative Advantage data have abnormal noises which contradict the relative stability of product diversity and the transformation of global production. The data noise entering the iteration algorithm, combined with positively related Fitness and Complexity, will be amplified in each recursion step. We introduce the Shortest Duration Constrained Hidden Markov Model (SDC-HMM) to denoise the Country-Product Matrix for the first time. After the country-product matrix test, the country case test, the noise estimation test and the panel regression test of national economic fitness indicators to predict GDP growth, we show that the SDC-HMM could reduce abnormal noise by about 25% and identify change points. This article provides intra-sample predictions that theoretically confirm that the SDC-HMM can improve the effectiveness of economic fitness indicators in interpreting economic growth.

Blockchain-Based IoT Secured Energy-Efficient Collaborative Neighbor Discovery Protocol

This paper proposes an Energy-efficient Secured Distributed Collaborative Neighbor Discovery protocol for IoT mobile sensing applications to enhance on IoT capabilities and efficiencies. Maximum throughput access control model with ultra-low-power constraints is proposed for blockchain-based IoT framework. Simulation result demonstrates the proposed protocol can achieve better discovery performance with minimum discovery latency and maximum duty cycle. Analysis of the comparison results present best choice of primes and duty cycle in the designed low-complexity algorithm.

A Secure Live Signature Verification with Aho–Corasick Histogram Algorithm for Mobile Smart Pad

There is a long history of using handwritten signatures to verify or authenticate a “signer” of the signed document. With the development of Internet technology, many tasks can be accomplished through the document management system, such as the applications of digital contracts or important documents, and more secure signature verification is demanded. Thus, the live handwriting signatures are attracting more interest for biological human identification. In this paper, we propose a handwriting signature verification algorithm by using four live waveform elements as the verification features. A new Aho–Corasick Histogram mechanism is proposed to perform this live signature verification. The benefit of the ACH algorithm is mainly its ability to convert time-series waveforms into time-series short patterns and then perform a statistical counting on the AC machine to measure the similarity. Since AC is a linearly time complexity algorithm, our ACH method can own a deterministic processing time. According to our experiment result, the proposed algorithm has satisfying performance in terms of speed and accuracy with an average of 91% accuracy.

Detection Line Spectrum of Ship Radiated Noise Based on a New 3D Chaotic System

This paper proposes a new detection model of a weak signal based on a third-order chaotic system. Using a dynamic analysis tool, such as the Lyapunov exponent and the bifurcation diagram, variations of dynamic behavior can be observed, and the weak signal underwater can be picked up. In order to improve the observability of detection signals in the time domain and frequency domain, the spectral entropy complexity algorithm (SE) and C0 complexity algorithms are used to analyze and extract the weak signal. The experimental results show that the spectrum extraction based on the complexity algorithm can accurately reflect the dynamic characteristics of the detected signal. It provides the theoretical direction and experimental data support for the application of the chaotic system in the field of acoustic detection.