Many research teams have developed mobile computing architectures to support the emergency and rescue services in a range of civil contingencies. These proposals are based on innovative technologies and show considerable creativity in the design of their user interfaces. In contrast, this paper presents lessons learned from the 2007 UK floods. Mobile telecommunications failed in many different ...

Optical chaos generated by perturbing semiconductor lasers has been viewed, over recent decades, as an excellent entropy source for fast physical random bit generation (RBG) owing to its high bandwidth and large fluctuations. However, most optical-chaos-based generators perform their quantization process in the electrical domain using analog-to-digital converters, so real-time rates a single ch...

Barnsley (2006) used chaos game in function systems and it gave rise to interesting fractals by combining it with function iterations. A fractal fern is generated by taking different probabilities in the chaos game. In this paper, we introduce two advanced iterations from nonlinear analysis into the study of IFS for generation and pattern recognition of new fractal ferns. Gottfried (1991), and ...

‎In the following text for arbitrary $X$ with at least two elements‎, ‎nonempty countable set $Gamma$‎ ‎we make a comparative study on the collection of generalized shift dynamical systems like $(X^Gamma,sigma_varphi)$ where $varphi:GammatoGamma$ is an arbitrary self-map‎. ‎We pay attention to sub-systems and combinations of generalized shifts with counterexamples regarding Devaney‎, ‎exact Dev...

{ The properties of time series generated by a perceptron with monotonic and non-monotonic transfer function, where the next input vector is determined from past output values, are examined. Analysis of the parameter space reveals the following main nding: a perceptron with a monotonic function can produce fragile chaos only whereas a non-monotonic function can generate robust chaos as well. Fo...

of the Dissertation Optimal Oscillations and Chaos Generation in Biologically-Inspired Systems by Saba Kohannim Doctor of Philosophy in Mechanical Engineering University of California, Los Angeles, 2016 Professor Tetsuya Iwasaki, Chair Biological systems display a variety of complex dynamic behaviors, ranging from periodic orbits to chaos. Regular rhythmic behavior, for instance, is associated ...

We propose in this paper a new simple continuous-time piecewise-linear three dimensional system for chaos generation. Nonlinearity in this model is introduced by the characteristic function of the Chua’s circuit given in [1]. Simulated results of some chaotic attractors are shown and justified numerically via computing the largest Lyapunov exponent. The possibility and the robustness of the cir...

In this paper, a fast chaos-based image encryption system with stream cipher structure is proposed. In order to achieve a fast throughput and facilitate hardware realization, 32-bit precision representation with fixed point arithmetic is assumed. The major core of the encryption system is a pseudo-random keystream generator based on a cascade of chaotic maps, serving the purpose of sequence gen...

We propose a scheme to generate binary code for baseband spread-spectrum communication by using a chain of coupled chaotic maps. We compare the performances of this type of spatiotemporal chaotic code with those of a conventional code used frequently in digital communication, the Gold code, and demonstrate that our code is comparable or even superior to the Gold code in several key aspects: sec...

Wideband chaos is of interest for applications such as random number generation or encrypted communications, which typically use optical feedback in a semiconductor laser. Here, we show that replacing conventional optical feedback with phase-conjugate feedback improves the chaos bandwidth. In the range of achievable phase-conjugate mirror reflectivities, the bandwidth increase reaches 27% when ...