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In this paper, we examine the design and application of a one-time pad encryption system for protecting data stored in the Cloud. Personalising security using a one-time pad generator at the client-end protects data from break-ins, side-channel attacks and backdoors in public encryption algorithms. The one-time pad binary sequences from modified analogue chaos oscillators initiated by noise encoded...
This article introduces the concept of output observer to chaos synchronisation applications. Here output observer is understood as a low order system designed to estimate a single measured variable of a higher order system only. In this work we show how this notion can be used to evaluate nonlinear systems with single output, being a chaotic state variable used as an example. Following this point...
A truly random number generator based on an autonomous bipolar-transistor cross-coupled chaotic oscillator is introduced. The effect of noise on the chaotic trajectory is analyzed. Inclusion of noise renders generated bits unpredictable, qualifying the proposed chaos based generator to be used as a truly random source. Simulation and experimental results verifying the feasibility and correct operation...
Accurate estimation of the amplitude parameter of sinusoidal signals from noisy observations is an important problem in many signal processing applications. In this paper, the problem is investigated under the assumption of non-Gaussian noise of Alpha stable distribution. According to the chaos theory and the properties of almost periodic functions, a new estimation method for amplitude of sinusoidal...
A chaotic detection scheme for a small-sized range-spread target in white Gaussian noise is developed. The basic idea is that a chaotic oscillator system is less influenced by noise, but it is very sensitive to periodic or pseudo-periodic signals. Firstly we concatenate the echoes with the same interested range cells from three successive pulses transmitted by high resolution radar end to end into...
Nowadays the traditional detecting method of weak signal amplitude is to use Duffing system. However it is limited in actual engineering application. Its structure is very simple but its dynamic characteristics are very complex. There are a lot of chaos oscillators being used to detect unknown signal so that the detection method is too complex. In this paper the dynamic characteristics of Lorenz system...
This paper is concerned with the weak signal detection based on the Duffing chaotic model. To solve the problem of low SNR in traditional testing methods, a method of detecting weak signals based on the Duffing oscillator coupled synchronization is proposed. Through the chaos theory and simulations, the characteristics of the coupled Duffing oscillator, the SNR threshold of the weak signal detection...
By analyzing principle and method of wavelet denoising and the Duffing oscillator, this paper presents a joint detection measurement system that was composed by wavelet denoising and the Duffing oscillator. Simulation experiment shows that using joint measurement system to detect weak signal from high noise background have a more satisfactory result, and further improve the ability of detecting weak...
Mixed-mode oscillations in a slow-fast dynamical system under weak perturbation are studied numerically. First, we make a band-limited extremely weak Gaussian noise, and apply this noise to this oscillator. Then, we observe random phenomenon from numerical study even if the noise is extremely weak. The mixed-mode oscillations are submerged by chaos due to extremely weak noise. We imagine that mixed-mode...
This work presents the data of experimental research of the coherent resonance phenomenon in nonlinear dynamic system - klystron oscillator with delayed feedback. It is shown that when klystron oscillator operates on a threshold of excitation, addition of an external white noise signal leads to excitation of coherent oscillations in system. Maximum of these oscillations is reached at certain power...
This paper briefly analyses the characteristic of the weak Global Positioning System (GPS) signal, elaborates the principle of signal detection with Duffing chaotic oscillator, presents a new method which adopted Duffing chaotic oscillator to detect and capture weak GPS signal. The method utilized the character of Duffing chaotic oscillator system, which is sensitive to the periodic signals whose...
The chaotic oscillator detecting is a new kind of weak signal detecting methods. The present chaotic oscillator detecting system has certain limits. And there is no theoretical foundation to define what kind of chaotic oscillators can constitute weak signal detecting system. This paper analyzes the sensitivity to weak signals and noise immunity of Duffing-Holmes and L-Y chaotic oscillator detecting...
Improving the method of measurement frequency based on the optimal theory when applying it to measuring the weak sinusoidal signal frequency based on the modified ADVP model. Using the genetic algorithm to search the maximum variance of system output signal, and then the frequency of weak sinusoidal signal with strong noise is measured. The simulation results demonstrate this improved method is effectiveness...
The detection system of a metal detector is proposed using a chaotic system-Duffing oscillator. The Duffing equation is improved on its expression suitable for high frequency weak signal detection of a metal detector through a time scale conversion. By calculating the two Lyapunov exponents of the duffing oscillator, the threshold value in critical state has been obtained accurately and it will be...
This paper introduces the use of chaotic Duffing oscillators to ballistocardiograph system for detection of weak signal. A ballistocardiograph (BCG) is an instrument that records the motions of the body imparted to it by the heart beat. It has been found that digital filters are not suitable for processing the BCG signals in noise. So in this paper, we propose a chaotic oscillators algorithm to detect...
Weak signal detection is very important in the downhole acoustic telemetry system. This paper introduces the Duffing oscillator weak signal detection method for the downhole acoustic telemetry systems. First, by solving the Duffing equation, analyzed the dynamics characteristic of Duffing oscillator and weak signal detection principle; and then on this basis, built Duffing oscillator circuit based...
Detecting weak periodic signal by chaotic oscillator is not only a new method, but also practical applications on chaos theory. However, when using this method to detect weak periodic signal, we have to know the frequency of weak periodic signal in advance, which limits applications of the method. This paper studies the relation between the frequency of measured weak periodic signal and max-variance...
Some methods using artificial neural network were proposed for solving to the Two-Spiral Problem (TSP). TSP is a problem which classifies two spirals drawn on the plane, and it is famous as the high nonlinear problem. In this paper, we propose a chaos glial network which connected to Multi-Layer Perceptron (MLP). The chaos glial network is inspired by astrocyte which is glial cell in the brain. By...
Ballistocardiogram (BCG) is a new, noninvasive technique used to record the movement of the body synchronous with the heartbeat due to left ventricular pump activity. However, BCG signal is so weak and easy to be jammed. In this paper, we achieved it through the measure system which is made by our BCG laboratory. Then, attempt to detect useful information from noises by chaotic oscillators. Experimental...
Chaos synchronization between identical or non-identical chaotic systems, via either linear or nonlinear feedback control strategy, had been thoroughly studied during these several decades. Most of existed studies were carried out under the conditions where the control signal affects the interacted system's behavior without noise pollution (or with idea transmitter channel). Unfortunately, the real...
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