•A fractional-order hyperchaotic complex system is constructed.•The fractional-order hyperchaotic complex system is digital circuit implemented by DSP platform.•An image encryption algorithm based on ...fractional-order hyperchaotic complex system is proposed.•Simulation results and performance analysis demonstrate the security and robustness of the proposed algorithm.
To explore characteristic of a new system with fractional order and complex variables, based on Adomian decomposition method (ADM), its nonlinear dynamical behaviors are discussed by bifurcation diagram, Lyapunov exponent spectrum, spectral entropy (SE) complexity, and DSP implementation. It is found that, for each parameter and order, there exists a large interval to make the system remain a hyper-chaotic state, which illustrates that the hyper-chaotic sequence could be more random to be applied in image encryption. Especially, a novel image encryption algorithm is proposed based on the fractional-order hyper-chaotic complex system and Galois field (GF). The column cyclic shift is used to scrambling part, the GF(17) algorithm is to diffuse pixel value. The security performances of algorithm are also analyzed. Finally, experiment results indicate that the proposed algorithm not only can effectively encrypt image, but also has better security features.
Several Dinophysis species produce diarrhoetic toxins (okadaic acid and dinophysistoxins) and pectenotoxins, and cause gastointestinal illness, Diarrhetic Shellfish Poisoning (DSP), even at low cell ...densities (<103 cells·L⁻¹). They are the main threat, in terms of days of harvesting bans, to aquaculture in Northern Japan, Chile, and Europe. Toxicity and toxin profiles are very variable, more between strains than species. The distribution of DSP events mirrors that of shellfish production areas that have implemented toxin regulations, otherwise misinterpreted as bacterial or viral contamination. Field observations and laboratory experiments have shown that most of the toxins produced by Dinophysis are released into the medium, raising questions about the ecological role of extracelular toxins and their potential uptake by shellfish. Shellfish contamination results from a complex balance between food selection, adsorption, species-specific enzymatic transformations, and allometric processes. Highest risk areas are those combining Dinophysis strains with high cell content of okadaates, aquaculture with predominance of mytilids (good accumulators of toxins), and consumers who frequently include mussels in their diet. Regions including pectenotoxins in their regulated phycotoxins will suffer from much longer harvesting bans and from disloyal competition with production areas where these toxins have been deregulated.
•An improper fractional-order laser chaotic system is constructed.•The improper fractional-order laser chaotic system is digital circuit implemented by DSP platform.•An image encryption algorithm ...based on improper fractional-order laser chaotic system is proposed.•Simulation results and performance analysis demonstrate the security and robustness of the proposed algorithm.
The fractional-order chaotic systems have characteristics of the all chaotic systems, however, the improper fractional-order chaotic systems have more complexity random sequences, which more suitable for chaotic cryptosystems. To investigate the application of improper fraction order chaotic system in chaotic cryptography, in this paper, an improper fractional-order laser chaotic system is constructed and applied in image encryption algorithm. The dynamic performances of the system are studied through phase diagrams, Lyapunov exponents spectrum, bifurcation diagrams and C0 complexity. Meanwhile, the improper fractional-order laser chaotic system is realized based on DSP platform. In addition, the performances of the designed encryption scheme are analyzed by key space, correlation coefficients, information entropy, histogram, differential attacks and robustness analysis. The experimental simulation results indicate that the improper fractional-order laser chaotic system not only has the abundant dynamic characteristics, but also has better security when it is used to image encryption algorithm. Therefore, this research would provide theoretical basis for the improper fractional-order laser chaotic system in security communications application.
In steel manufacturing process, one X-ray fluorescence analyzer with 40 crystal spectrometers is sometimes used for elemental compositional monitoring to control the process. The present paper is a ...suggestion to improve the performance of this bulk of X-ray fluorescence spectrometers by replacing the proportional/scintillation counters by silicon drift detectors (SDD) with digital signal processors (DSP). The wavelength dispersive X-ray fluorescence spectrometer with SDDs will enable the automatic adjustment of the optimal measuring condition. The shortcomings of both SDD and proportional counters are discussed.
Several species of Dinophysis produce one or two groups of lipophilic toxins: okadaic acid (OA) and its derivatives; or the dinophysistoxins (DTXs) (also known as diarrhetic shellfish poisons or DSP ...toxins) and pectenotoxins (PTXs). DSP toxins are potent inhibitors of protein phosphatases, causing gastrointestinal intoxication in consumers of contaminated seafood. Forty years after the identification of Dinophysis as the causative agent of DSP in Japan, contamination of filter feeding shellfish exposed to Dinophysis blooms is recognized as a problem worldwide. DSP events affect public health and cause considerable losses to the shellfish industry. Costly monitoring programs are implemented in regions with relevant shellfish production to prevent these socioeconomic impacts. Harvest closures are enforced whenever toxin levels exceed regulatory limits (RLs). Dinophysis species are kleptoplastidic dinoflagellates; they feed on ciliates (Mesodinium genus) that have previously acquired plastids from cryptophycean (genera Teleaulax, Plagioselmis, and Geminigera) nanoflagellates. The interactions of Dinophysis with different prey regulate their growth and toxin production. When Dinophysis cells are ingested by shellfish, their toxins are partially biotransformed and bioaccumulated, rendering the shellfish unsuitable for human consumption. DSP toxins may also affect shellfish metabolism. This book covers diverse aspects of the abovementioned topics—from the laboratory culture of Dinophysis and the kinetics of uptake, transformation, and depuration of DSP toxins in shellfish to Dinophysis population dynamics, the monitoring and regulation of DSP toxins, and their impact on the shellfish industry in some of the aquaculture regions that are traditionally most affected, namely, northeastern Japan, western Europe, southern Chile, and New Zealand.
The memristor has received much attention in recent years because of its natural nonlinearity, but the research on discrete memristor is just beginning. For this reason, a new discrete memristor ...model is constructed, and a new three-dimensional hyperchaotic map is constructed by coupling the new discrete memristor. Firstly, the stability of the map is discussed. And then, the dynamical characteristics are analyzed by using the phase diagram, Lyapunov exponent spectrum (LEs), bifurcation diagram and attractor basins, etc. Meanwhile, the state transition and the attractor coexistence with periodic, quasi-periodic, chaotic and hyperchaotic have been studied. In particular, the hyperchaotic map is implemented on the DSP hardware platforms, demonstrating the realizability of the map. Finally, the discrete hyperchaotic map is applied to image encryption. The results of the study provide a reference for the application and teaching of discrete memristor circuits in chaos.
The design of application-specific integrated circuits (ASIC) is at the core of modern ultra-high-speed transponders employing advanced digital signal processing (DSP) algorithms. This manuscript ...discusses the motivations for jointly utilizing transmission techniques such as probabilistic shaping and digital sub-carrier multiplexing in digital coherent optical transmissions systems. First, we describe the key-building blocks of modern high-speed DSP-based transponders working at up to 800G per wave. Second, we show the benefits of these transmission methods in terms of system level performance. Finally, we report, to the best of our knowledge, the first long-haul experimental transmission - e.g., over 1000 km - with a real-time 7 nm DSP ASIC and digital coherent optics (DCO) capable of data rates up to 1.6 Tb/s using two waves (2 × 800G).
Infrared detectors are usually characterized by 1/f noise when operating with biasing. This type of noise significantly reduces detection capabilities for low-level and slow signals. There are a few ...methods to reduce the influence of 1/f noise, like filtering or chopper stabilization with lock-in. Using the first one, a simple 1st-order analog low-pass filter built-in amplifier usually cuts off 1/f noise fluctuations at low frequencies. In comparison, the stabilization technique modulates the signal transposing to a higher frequency with no 1/f noise and then demodulates it back (lock-in amplifiers). However, the flexible tuned device, which can work precisely at low frequencies, is especially desirable in some applications, e.g., optical spectroscopy or interferometry. The paper describes a proof-of-concept of an IR detection module with an adjustable digital filter taking advantage of finite impulse response type. It is based on the high-resolution analog-to-digital converter, field-programmable gate array, and digital-to-analog converter. A microcontroller with an implemented user interface ensures control of such a prepared filtering path. The module is a separate component with the possibility of customization and can be used in experiments or applications in which the reduction of noises and unexpected interferences is needed.
We discuss technology options and challenges for scaling intra-datacenter interconnects beyond 1 Tb/s bandwidths, with focus on two possible approaches: pulse amplitude modulation (PAM)-based ...intensity modulation-direct detection (IM-DD) and baud-rate sampled coherent technology. In our studies, we compare the performance of various orders of PAM modulation (PAM4 to 8). In addition to these fixed PAM signaling options, a flexible PAM (FlexPAM) technique leveraging granularity in spectral efficiency (SE) is proposed to maximize link margin. For baud-rate sampled coherent technology, we propose a simplified digital signal processing (DSP) architecture to bring down power consumption of the coherent approach closer to that of IM-DD PAM. We also propose two new phase noise tolerant 2D coherent modulation formats to relax the laser linewidth requirement. In closing, a comparative study of fixed IM-DD PAM versus coherent polarization multiplexed-quadrature amplitude modulation (PM-QAM) is presented for a 1.6 Tb/s solution (200 Gb/s per dimension), with consideration of link loss/reach budget, power consumption, implementation complexity, as well as fan-out granularity.
In long haul optical fiber communication networks, whichcan span thousands of kilometers, bandwidth is at a premium due to the relatively low availability of optical fibers when compared with network ...traffic demands. Therefore, these networks require the highest performance in the physical layer, with transceivers that are capable of extracting all the available capacity from each optical fiber. Digital coherent transmitters and receivers, which enhance optical transmission systems by using digital signal processing, are essential for achieving this goal. This tutorial discusses the digital signal processing techniques that are used in the design of high performance coherent modems to compensate for adverse channel effects such as fiber impairments and optoelectronic device non-idealities.
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