A Chaotic-Based Pseudo-Random Bit Generator for Navigation Applications

2013 ◽  
Vol 311 ◽  
pp. 99-104 ◽  
Author(s):  
Yi Te Chiang ◽  
He Sheng Wang ◽  
Yung Nien Wang
Keyword(s):  
Navigation System ◽  
Secure Communication ◽  
Initial Conditions ◽  
Random Noise ◽  
Logistic Map ◽  
Random Bit Generator ◽  
Shift Keying ◽  
Chaotic Nature ◽  
Set Up ◽  
Correlation Properties

In this paper, we propose a novel method to generate pseudo-random-noise (PRN) bits for navigation applications. In the present method, the code sequence generator is constructed based on two chaotic logistic maps running parallel and starting from independent initial conditions. The logistic map is a simple mathematical model that shows bewildering complex behavior. By appro-priately setting the initial conditions, the PRN sequence is then generated by comparing the outputs of both logistic maps. Several simulations are set up to verify the correlation properties of the pseudo-random bit generator (PRBG). The result shows that the code sequences generated by the proposed PRBG have great auto- and cross-correlation properties, which are very similar to the PRN sequences used by GPS navigation system. The RPBG sequences are therefore suitable for signal ranging that is used comprehensively in the navigation system. On the other hand, the chaotic nature of the proposed PRBG codes can provide more secure communication than the traditional PRN sequences. The proposed PRN sequences are well suitable to be incorporated with the so-called chaotic shift keying (CSK) modulation.

scholarly journals Novel Method of Secure Communication using Logistic Map

2019 ◽  
Vol 8 (2S7) ◽  
pp. 603-605
Keyword(s):  
Chaotic System ◽  
Secure Communication ◽  
Control Parameter ◽  
Initial Conditions ◽  
Daily Life ◽  
Logistic Map ◽  
New Concepts ◽  
Chaotic Cryptography ◽  
Significant Research ◽  
Novel Method

Significant research efforts have been invested in recent years to export new concepts for secure cryptographic methods. Many mathematicians are attracted by Chaos functions as it has sensitive nature toward its initial conditions and their colossal suitability to problems in daily life. Inspired by new researches, a new chaotic cryptography algorithm is proposed in this paper. The key feature of this approach is that instantaneous key is generated at host independently that is used to determine the type of operations on each pixel. The information available in images is 24 bit RGB these value are modified mathematically using eight reversible operations. Also during encryption, the control parameter of the chaotic system is updated timely.

scholarly journals A Robust Watermarking Scheme for Online Multimedia Copyright Protection Using New Chaotic Map

2018 ◽  
Vol 2018 ◽  
pp. 1-20 ◽  
Author(s):  
Amir Anees ◽  
Iqtadar Hussain ◽  
Abdulmohsen Algarni ◽  
Muhammad Aslam
Keyword(s):  
Digital Media ◽  
Secure Communication ◽  
Initial Conditions ◽  
Chaotic Map ◽  
Logistic Map ◽  
Digital Data ◽  
Robust Watermarking ◽  
Unified Framework ◽  
Watermarking Scheme ◽  
Randomness Tests

The protection of copyrights of digital media uploaded to the Internet is a growing problem. In this paper, first, we present a unified framework for embedding and detecting watermark in digital data. Second, a new robust watermarking scheme is proposed considering this concern. The proposed work incorporates three chaotic maps which specify the location for embedding the watermark. Third, a new chaotic map, the Extended Logistic map, is proposed in this work. The proposed map has a bigger range than logistic and cubic maps. It has shown good results in a bifurcation, sensitivity to initial conditions, and randomness tests. Furthermore, with the detailed analysis of initial parameters, it is justified that Extended Logistic map can be used in secure communication, particularly watermarking. Fourth, to check the robustness of proposed watermarking scheme, we have done a series of analyses and standard attacks. The results confirm that the proposed watermarking scheme is robust against visual and statistical analysis and can resist the standard attacks.

scholarly journals An Experimental Realization of a Chaos-Based Secure Communication Using Arduino Microcontrollers

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Mauricio Zapateiro De la Hoz ◽  
Leonardo Acho ◽  
Yolanda Vidal
Keyword(s):  
Simple Model ◽  
Communication System ◽  
Secure Communication ◽  
Initial Conditions ◽  
Logistic Map ◽  
Communication Channels ◽  
Receiver Side ◽  
Experimental Realization ◽  
Chaotic Signals ◽  
Message Signal

Security and secrecy are some of the important concerns in the communications world. In the last years, several encryption techniques have been proposed in order to improve the secrecy of the information transmitted. Chaos-based encryption techniques are being widely studied as part of the problem because of the highly unpredictable and random-look nature of the chaotic signals. In this paper we propose a digital-based communication system that uses the logistic map which is a mathematically simple model that is chaotic under certain conditions. The input message signal is modulated using a simple Delta modulator and encrypted using a logistic map. The key signal is also encrypted using the same logistic map with different initial conditions. In the receiver side, the binary-coded message is decrypted using the encrypted key signal that is sent through one of the communication channels. The proposed scheme is experimentally tested using Arduino shields which are simple yet powerful development kits that allows for the implementation of the communication system for testing purposes.

scholarly journals CONVERGENCE TO THE CRITICAL ATTRACTOR AT INFINITE AND TANGENT BIFURCATION POINTS

2006 ◽  
Vol 16 (08) ◽  
pp. 2369-2375
Author(s):  
R. TONELLI
Keyword(s):  
Phase Space ◽  
Lyapunov Exponent ◽  
Numerical Experiment ◽  
Power Law ◽  
Initial Conditions ◽  
Logistic Map ◽  
Nonextensive Statistical Mechanics ◽  
Bifurcation Points ◽  
Tangent Bifurcation ◽  
Set Up

The dynamics of the convergence to the critical attractor for the logistic map is investigated. At the border of chaos, when the Lyapunov exponent is zero, the use of the nonextensive statistical mechanics formalism allows to define a weak sensitivity or insensitivity to initial conditions. Using this formalism we analyze how a set of initial conditions spread all over the phase space converges to the critical attractor in the case of infinite bifurcation and tangent bifurcation points. We show that the phenomena is governed in both cases by a power-law regime but the critical exponents depend on the type of bifurcation and may also depend on the numerical experiment set-up. Differences and similarities between the two cases are also discussed.

scholarly journals On Kaufmann's theory of the impact of the pianoforte hammer

1920 ◽  
Vol 97 (682) ◽  
pp. 99-110 ◽  
Keyword(s):  
Initial Conditions ◽  
Practical Importance ◽  
Prima Facie ◽  
Point Of View ◽  
Infinite Length ◽  
Modes Of Vibration ◽  
Rigorous Treatment ◽  
The Subject ◽  
Set Up ◽  
The Impact

The theory of the vibrations of the pianoforte string put forward by Kaufmann in a well-known paper has figured prominently in recent discussions on the acoustics of this instrument. It proceeds on lines radically different from those adopted by Helmholtz in his classical treatment of the subject. While recognising that the elasticity of the pianoforte hammer is not a negligible factor, Kaufmann set out to simplify the mathematical analysis by ignoring its effect altogether, and treating the hammer as a particle possessing only inertia without spring. The motion of the string following the impact of the hammer is found from the initial conditions and from the functional solutions of the equation of wave-propagation on the string. On this basis he gave a rigorous treatment of two cases: (1) a particle impinging on a stretched string of infinite length, and (2) a particle impinging on the centre of a finite string, neither of which cases is of much interest from an acoustical point of view. The case of practical importance treated by him is that in which a particle impinges on the string near one end. For this case, he gave only an approximate theory from which the duration of contact, the motion of the point struck, and the form of the vibration-curves for various points of the string could be found. There can be no doubt of the importance of Kaufmann’s work, and it naturally becomes necessary to extend and revise his theory in various directions. In several respects, the theory awaits fuller development, especially as regards the harmonic analysis of the modes of vibration set up by impact, and the detailed discussion of the influence of the elasticity of the hammer and of varying velocities of impact. Apart from these points, the question arises whether the approximate method used by Kaufmann is sufficiently accurate for practical purposes, and whether it may be regarded as applicable when, as in the pianoforte, the point struck is distant one-eighth or one-ninth of the length of the string from one end. Kaufmann’s treatment is practically based on the assumption that the part of the string between the end and the point struck remains straight as long as the hammer and string remain in contact. Primâ facie , it is clear that this assumption would introduce error when the part of the string under reference is an appreciable fraction of the whole. For the effect of the impact would obviously be to excite the vibrations of this portion of the string, which continue so long as the hammer is in contact, and would also influence the mode of vibration of the string as a whole when the hammer loses contact. A mathematical theory which is not subject to this error, and which is applicable for any position of the striking point, thus seems called for.

scholarly journals Formation of supermassive black hole seeds in nuclear star clusters via gas accretion and runaway collisions

2021 ◽  
Author(s):  
Arpan Das ◽  
Dominik R G Schleicher ◽  
Nathan W C Leigh ◽  
Tjarda C N Boekholt
Keyword(s):  
Black Holes ◽  
Initial Conditions ◽  
High Redshift ◽  
Star Clusters ◽  
Gas Reservoir ◽  
Highly Sensitive ◽  
Stellar Collisions ◽  
Key Variables ◽  
Chaotic Nature ◽  
Gas Accretion

Abstract More than two hundred supermassive black holes (SMBHs) of masses ≳ 109 M⊙ have been discovered at z ≳ 6. One promising pathway for the formation of SMBHs is through the collapse of supermassive stars (SMSs) with masses ∼103 − 5 M⊙ into seed black holes which could grow upto few times 109 M⊙ SMBHs observed at z ∼ 7. In this paper, we explore how SMSs with masses ∼103 − 5 M⊙ could be formed via gas accretion and runaway stellar collisions in high-redshift, metal-poor nuclear star clusters (NSCs) using idealised N-body simulations. We explore physically motivated accretion scenarios, e.g. Bondi-Hoyle-Lyttleton accretion and Eddington accretion, as well as simplified scenarios such as constant accretions. While gas is present, the accretion timescale remains considerably shorter than the timescale for collisions with the most massive object (MMO). However, overall the timescale for collisions between any two stars in the cluster can become comparable or shorter than the accretion timescale, hence collisions still play a crucial role in determining the final mass of the SMSs. We find that the problem is highly sensitive to the initial conditions and our assumed recipe for the accretion, due to the highly chaotic nature of the problem. The key variables that determine the mass growth mechanism are the mass of the MMO and the gas reservoir that is available for the accretion. Depending on different conditions, SMSs of masses ∼103 − 5 M⊙ can form for all three accretion scenarios considered in this work.

Comparison of Times of Synchronization of Chaotic Burke-Shaw Attractor with Active Control and Integer and Optimum Fractional-Order Pecaro Carroll Method

2021 ◽  
Author(s):  
Ali Durdu ◽  
Yılmaz Uyaroğlu
Keyword(s):  
Active Control ◽  
Fractional Order ◽  
Chaotic Attractor ◽  
Secure Communication ◽  
Chaotic Systems ◽  
Control Method ◽  
Initial Conditions ◽  
Data Communication ◽  
Experimental Results ◽  
Active Control Method

Abstract Many studies have been introduced in the literature showing that two identical chaotic systems can be synchronized with different initial conditions. Secure data communication applications have also been made using synchronization methods. In the study, synchronization times of two popular synchronization methods are compared, which is an important issue for communication. Among the synchronization methods, active control, integer, and fractional-order Pecaro Carroll (P-C) method was used to synchronize the Burke-Shaw chaotic attractor. The experimental results showed that the P-C method with optimum fractional-order is synchronized in 2.35 times shorter time than the active control method. This shows that the P-C method using fractional-order creates less delay in synchronization and is more convenient to use in secure communication applications.

Modeling and prediction for the oxidation efficiency of magnesium sulfite in aeration tank of magnesium-based seawater exhaust gas clean system

2017 ◽  
Vol 233 (1) ◽  
pp. 164-173
Author(s):  
Quan Liu ◽  
Yimin Zhu ◽  
Tie Li ◽  
Xiaojia Tang ◽  
Weifeng Liu ◽  
...  
Keyword(s):  
Flow Field ◽  
Initial Conditions ◽  
Negative Impact ◽  
Fluid Model ◽  
Aeration Tank ◽  
Exhaust Gas ◽  
Clean System ◽  
Physics Modeling ◽  
Set Up ◽  
Oxidation Efficiency

In magnesium-based seawater exhaust gas clean system, the desulfurization by-product, magnesium sulfite (MgSO3), has a negative impact on the ecological environment, which needs to be treated to make harmless. Due to the limited space on board, the aeration oxidation method is used to convert it to magnesium sulfate. Because of the variable size, shape and flow field of aeration tank, it is difficult and expensive to design and verify the oxidation efficiency of the aeration tank by experimental method. In this work, in order to predict the oxidation efficiency accurately, RFlow, a computational fluid dynamics software, was used to analyze the flow field and MgSO3 oxidation reaction in aeration tank. The subdomain technology was adopted for physics modeling and mesh generation of the aeration tank, and the total number of meshes was 285,000. The multi-phase flow field model was set up using the multi-fluid model and dispersive k-ε turbulence model. Under the given initial conditions, the predicted oxidation efficiency was 94.2%. Compared with the results of the actual ship test, the prediction model for MgSO3 oxidation efficiency of the aeration tank is reliable.

scholarly journals Efficient error correcting scheme for chaos shift keying signals

2019 ◽  
Vol 9 (5) ◽  
pp. 3550
Author(s):  
Hikmat N. Abdullah ◽  
Thamir R. Saeed ◽  
Asaad H. Sahar
Keyword(s):  
Error Correction ◽  
Logistic Map ◽  
Chaotic Sequence ◽  
Chaos Communication ◽  
Shortest Distance ◽  
Correction Scheme ◽  
Shift Keying ◽  
Minimum Delay ◽  
Modified Logistic Map ◽  
Chaos Shift Keying

An effective error-correction scheme based on normalized correlation for a non coherent chaos communication system with no redundancy bits is proposed in this paper. A modified logistic map is used in the proposed scheme for generating two sequences, one for every data bit value, in a manner that the initial value of the next chaotic sequence is set by the second value of the present chaotic sequence of the similar symbol. This arrangement, thus, has the creation of successive chaotic sequences with identical chaotic dynamics for error correction purpose. The detection symbol is performed prior to correction, on the basis of the suboptimal receiver which anchors on the computation of the shortest distance existing between the received sequence and the modified logistic map’s chaotic trajectory. The results of the simulation reveal noticeable Eb/No improvement by the proposed scheme over the prior to the error- correcting scheme with the improvement increasing whenever there is increase in the number of sequence N. Prior to the error-correcting scheme when N=8, a gain of 1.3 dB is accomplished in E<sub>b</sub>/N<sub>o</sub> at 10<sup>-3 </sup>bit error probability. On the basis of normalized correlation, the most efficient point in our proposed error correction scheme is the absence of any redundant bits needed with minimum delay procedure, in contrast to earlier method that was based on suboptimal method detection and correction. Such performance would render the scheme good candidate for applications requiring high rates of data transmission.

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