Data encryption based on a 9D complex chaotic system with quaternion for smart grid

With the development of smart grid, operation and control of a power system can be realized through the power communication network, especially the power production and enterprise management business involve a large amount of sensitive information, and the requirements for data security and real-time transmission are gradually improved. In this paper, a new 9-dimensional(9D) complex chaotic system with quaternion is proposed for the encryption of smart grid data. Firstly, we present the mathematical model of the system, and analyze its attractors, bifurcation diagram, complexity,and 0–1 test. Secondly, the pseudo-random sequences are generated by the new chaotic system to encrypt power data.Finally, the proposed encryption algorithm is verified with power data and images in the smart grid, which can ensure the encryption security and real time. The verification results show that the proposed encryption scheme is technically feasible and available for power data and image encryption in smart grid.

A novel suspension-floating-circulating fluidized combustion technology for coal slurry

A novel suspension-floating-circulating fluidized combustion technology is proposed for burning coal slurry fuel in traditional circulating ftuidized bed boilers （CFBB）. This technology can solve some existing problems in large- capacity CFBB burning coal slurry. The principles of the suspension-floating-circulating fluidized combustion technology were introduced in detail in this paper. A 130 t/h CFBB was retrofitted based on the technology, and the retrofitted system mainly includes a long-distance transport sub-system, a bed-material conveying sub-system with a wind-seal device invented by the authors, a superheater thermoregulation device using a novel temperature regulator, a return loop flu- idization facility, and a pneumatic ash conveying sub-system with sealed pump. The achieved performance of the retro- fitted CFBB shows that the thermal efficiency is 89.83 %, the combustion efficiency is 96.24 %, and the blending proportion of slurry is 94 %.

Multi-Object Tracking Based on Segmentation and Collision Avoidance

An approach to track multiple objects in crowded scenes with long-term partial occlusions is proposed. Tracking-by-detection is a successful strategy to address the task of tracking multiple objects in unconstrained scenarios,but an obvious shortcoming of this method is that most information available in image sequences is simply ignored due to thresholding weak detection responses and applying non-maximum suppression. This paper proposes a multi-label conditional random field（ CRF） model which integrates the superpixel information and detection responses into a unified energy optimization framework to handle the task of tracking multiple targets. A key characteristic of the model is that the pairwise potential is constructed to enforce collision avoidance between objects,which can offer the advantage to improve the tracking performance in crowded scenes. Experiments on standard benchmark databases demonstrate that the proposed algorithm significantly outperforms the state-of-the-art tracking-by-detection methods.

High-sensitivity modulation of electromagnetically induced transparency analog in a THz asymmetric metasurface integrating perovskite and graphene

Active control of the electromagnetically induced transparency(EIT)analog is desirable in photonics development.Here,we theoretically and experimentally proposed a novel terahertz(THz)asymmetric metasurface structure that can possess high-sensitivity modulation under extremely low power density by integrating perovskite or graphene.Using the novel metasurface structure with the perovskite coating,the maximum amplitude modulation depth(AMD)of this perovskite-based device reached 490.53%at a low power density of 12.8037 mW/cm^(2).In addition,after the novel THz metasurface structure was combined with graphene,this graphene-based device also achieved high AMD with the maximum AMD being 180.56%at 16.312 mW/cm^(2),and its transmission amplitude could be electrically driven at a low bias voltage.The physical origin of this modulation was explained using a two-oscillator EIT model.This work provides a promising platform for developing high-sensitivity THz sensors,light modulators,and switches.