A novel down-sampling filter named moving accumulative sign filter (MASF) is proposed for low-power down-sampling of large-scale binary and ternary data. Besides, the MASF has greatly circuit realization advantages than state-of-the-art cascaded-integrator-comb (CIC) filter, especially in the area of low-power design. The theory of MASF is proposed and introduced comprehensively, including the algorithm model, transfer function, and frequency response characteristics. The pipeline voting architecture is applied to the implementation of the MASF to improve the speed of data processing, which simplifies the circuit structure and reduce the power consumption. The MASF circuits of general application based on pipeline voting are designed for binary and ternary signals only using D flip-flop and logic gates. The area and power consumption of MASF are reduced by 86% and 88% compared with CIC filter under the same conditions on FPGA. What’s more, a hardware-friendly pooling algorithm named polar-pooling is proposed based on MASF for binary and ternary feature maps, which greatly reduces the time and space complexity of pooling. Compared with max-pooling and average-pooling, the processing time of polar-pooling is reduced by more than 75% for a$200\times 200$binary image. The two-stage MASF circuit for ternary signal processing is implemented at 40-nm CMOS process, compared with state-of-the-arts cascade-of-integrators filter which cascading two integrators, the normalized power consumption of proposed two-stage MASF circuit has 67% reduction and the area has 75% reduction.

Although multiscroll attractors in dissipative chaotic systems (DCSs) have complex properties, they may be subject to reconstruction attacks in the field of information security. Conservative chaotic systems (CCSs) have no attractors and can effectively resist this danger. To obtain grid-scroll conservative chaotic flows with complex dynamical behaviors, this article proposes a symmetric sine function constrained by piecewise linear functions (Sin-PLF). Then, a 4-D Hamiltonian conservative chaotic system (HCCS) with line equilibrium and grid-scroll chaotic flows is presented by replacing the state variables with the Sin-PLF. Single-, two-, and three-directional controllable multiscroll chaotic flows are found in the system, and the stationary points of the Hamiltonian function are used to analyze the generation mechanism of these scrolls. Besides, the initial offset-boosted behavior is also found, which generates coexisting chaotic flows and coexisting quasiperiodic flows in single-, two-, and three-directions. Based on the FPGA board, the multiscroll chaotic flows in the 4-D HCCS are acquired experimentally to verify their feasibility. Finally, potential applications of the proposed grid-scroll CCS are shown through a simple pseudorandom number generator (PRNG).

Estimating stature based on skeleton plays an important role in forensic investigation and individual identification. The skull consists of hard tissue and is the best-preserved part of an individual’s postmortem skeleton. Therefore, in many cases, it is the only one available. The purpose of this study was to evaluate the correlation between stature and skull measurements in a contemporary Chinese population using a 3D skull model reconstructed from CT scans. A total of 320 skull models were sampled in this study. These data were collected from populations in northern and southern China. Of these, 256 were used to establish regression equations and 64 were used for blind testing. We performed twelve skull measurements for each skull and used the Pearson correlation coefficient to estimate the correlation between stature and each measurement. Simple linear regression equations and multiple regression equations are established based on the measurement data and the correlation between stature and measurement variables. The results showed that all skull measurements except for Frontal sinus height were significantly correlated with stature. The standard errors of estimation (SEE) of the multivariate regression equation are smaller than that of the simple linear regression equation, which indicates that the multivariate regression equation is more reliable in estimating the stature of the Chinese population. Compared with other researchers, the regression equation established in this paper is used to estimate the stature of the Chinese population is effective. The results of this study are meaningful to forensics, anthropologists, and archaeologists, and can help them solve complex medical-legal problems.

Conservative chaotic systems (CCSs) have unique advantages over dissipative chaotic systems (DCSs) in the fields of secure communication and pseudo-random number generators (PRNGs), etc. However, there are relatively fewer reports on CCSs than DCSs. To this end, this paper proposes an effective method for constructing a family of Hamiltonian conservative chaotic systems (HCCSs) by letting any three of the four sub-bodies denoted by 4D generalized Euler equations share a rotation axis. From theoretical analysis to experimental verification, one of the proposed HCCSs is studied thoroughly to demonstrate the effectiveness of this method. The example system has an infinite number of equilibrium points, which belong to either centers or saddles, resulting in hidden chaos. Besides, through the bifurcation diagram, parametric chaotic set, and Lyapunov exponent, richly dynamic behaviors related to parameters are displayed. Moreover, the 3D phase portraits verify that the Hamiltonian energy is conservative. Numerous energy-related coexisting orbits are discovered in this system, such as the coexistence of quasi-periodic orbits, chaotic orbits, and chaotic quasi-periodic orbits. Furthermore, the breadboard-based circuit is implemented to illustrate the HCCS’s physical feasibility. Finally, the PRNG based on the HCCS has excellent randomness in terms of NIST and TESTU01 test results.

Fractal and chaos are two major phenomena in nonlinear systems. A few combinations of chaos with fractal for generating multiscroll attractors are reported. Thus, based on Chua multiscroll chaotic systems, a novel multiring chaotic system is proposed via Julia multifractal processes. The main purpose of this work is to make up for the deficiency of various fractal processes to further improve the performance of chaotic systems. A new class of multiscroll attractors is generated by combining different fractal processes, including symmetrical multiring attractor, separated multiring attractor, and nested multiring attractor. Furthermore, dynamic behaviors of the fractal chaotic system are analyzed by means of Lyapunov exponents and bifurcation diagram to indicate that the system exhibits chaotic characteristics. Experiments on the spectrum entropy (SE) complexity and image encryption performance demonstrate the good performance of the proposed fractal-based attractors. To verify the feasibility of multiring chaotic system, the various fractal-based attractors generated are implemented by micro controller unit (MCU), and the separated multiring attractors are observed on the digital oscilloscope.