Adaptive Time Frequency Distribution Based on Linear Chirp Modulated Gaussian Functions

We propose a method that uses linear chirp modulated Gaussian functions as the elementary functions, by adaptively adjusting variances, time frequency centers and sweep rates, to decompose signals. By taking WVD, an improved adaptive time frequency distribution is developed, which is non negative, free of cross term interference, and of better time frequency resolution. The paper presents an effective numerical algorithm to estimate the optimal parameters of the basis. Simulations indicate that the proposed approach is effective in analyzing signal's time frequency behavior.

Adaptive Fourier Decomposition Based Time-Frequency Analysis

The attempt to represent a signal simultaneously in time and frequency domains is full of challenges. The recently proposed adaptive Fourier decomposition （AFD） offers a practical approach to solve this problem. This paper presents the principles of the AFD based time-frequency analysis in three aspects： instantaneous frequency analysis, frequency spectrum analysis, and the spectrogram analysis. An experiment is conducted and compared with the Fourier transform in convergence rate and short-time Fourier transform in time-frequency distribution. The proposed approach performs better than both the Fourier transform and short-time Fourier transform.

Promote the All-round Development of China's Human Right Cause in the New Era——Summary of the Symposium on “Deeply Studying and Implementing the Spirit of the 20th CPC National Congress and Adhering to the Chinese Path of Human Rights Development”

On November 8, 2022, the symposium on “Deeply Studying and Implementing the Spirit of the 20thCPC National Congress and Adhering to the Chinese Path of Human Rights Development” was held by the China Society for Human Rights Studies in Beijing. Focusing on “the leadership of the CPC and human rights development”, “adapting Marxism to the Chinese context and the needs of our times and human rights theories in contemporary China”, “the Chinese path to modernization and the new form of human rights civilization”, “Chinese human rights solutions and global human rights governance”, “making a better China’s story of advancing human rights and constructing human rights discourse system”, and other topics, the participants reached broad consensus after discussion, and the symposium achieved fruitful results.

INDIRECT ACCELERATED ADAPTIVE FUZZY CONTROLLER

According to a type of normal nonlinear system, an indirect adaptive fuzzy （IAF） controller has been applied to those systems where no accurate mathematical models of the systems under control are available. To satisfy with system performance, an indirect accelerated adaptive fuzzy （IAAF） controller is proposed, and its general form is presented. The general form IAAF controller ensures necessary control criteria and system＇s global stability using Lyapunov Theorem. It has been proved that the close-loop system error converges to a small neighborhood of equilibrium point. The optimal IAAF controller is derived to guarantee the process＇s shortest settling time. Simulation results indicate the IAAF controller make the system more stable, accurate, and fast.

Time-course effects of different fiber-rich ingredients on energy values,microbiota composition and SCFA profile in growing pigs

This study was to investigate time-course effects of different types of dietary fiber on the energy values,fecal microbiota and short-chain fatty acid(SCFA)concentration in growing pigs.A total of 24 barrows(initial body weight,19.8±0.5 kg)were assigned to 4 dietary treatments based on body weight(BW)in a completely randomized design,including a basal diet(CON)and 3 fiber-rich diets replacing corn,soybean meal and soybean oil in the CON diet with 20%sugar beet pulp(SBP),defatted rice bran(DFRB)or soybean hull(SBH),respectively.Fresh feces were sampled on d 7,14 and 21,followed by 5 d total feces and urine collections.The results showed that there were no differences in DE and ME between any of the fiber ingredients on d 7,14 or 21.However,fiber inclusion decreased the DE and ME of the diet(P<0.05)regardless of the time effect.Principal coordinate analysis(PCoA)revealed distinctly different microbial communities on the DFRB diet and SBH diet across different times(P<0.05)and the fecal microbiota of the 4 diet groups demonstrated notably distinct clusters at each time point(P<0.05).With adaptation time increased from 7 to 21 d,cellulose-degrading bacteria and SCFA-producing bacteria(e.g.,Ruminococcaceae_UCG-014,Rikenellaceae_RC9_gut_group and Bifidobacterium)increased in the fiber inclusion diets,and pathogenic genera(e.g.,Streptococcus and Selenomonas)were increased in the basal diet(P<0.05).Furthermore,the gut microbiota of growing pigs adapted more easily and quickly to the SBP diet compared to the DFRB diet,as reflected by the concentration of propionate,butyrate,isovalerate and total SCFA which increased with time for growing pigs fed the DFRB diet(P<0.05).Collectively,our results indicated at least 7 d adaptation was required to evaluate the energy values of fiber-rich ingredients,as the hindgut microbiota of growing pigs may need more time to adapt to a high fiber diet,especially for insoluble dietary fiber.

Application of adaptive filter in time delay estimation——generalized quadratic interpolation method

The time delay estimation (TDE) of two different received signals from the same source has attracted many interests of researchers in the field of signal processing. A method described for precisely estimating time delay in this paper is based on the assumption that little priori knowledge on statistical characteristics is available for the received signals. The variance of the estimate is derived . The basic architecture of this method is to use the adaptive noise canceller, in the steady state , and to interpolate the weight coefficients by using a generalized quadratic interpolation matrix. The formula of the time delay estimation is presented . The method proposed by F.A. Reed is a special case of this method . The hardware implementation is much easier than that of the conventional time delay estimation method . The results of the system simulation and the experimental results at sea show a good agreement with the theoretical analysis.

Adapting Backward Error Recovery to Parallel Real Time Systems

The problem of adapting backward error recovery to parallel real time systems is discussed in this paper. Because of error propagation among different cooperating processes, an error occurring in one process may influence some important outputs in other processes. Therefore, a local output has to be delayed until its validity is confirmed globally. Since backward error recovery adopts redundancy of computing time instead of processing equipment, the variation of the actual execution time of a cooperating process may be very large if it works in an unreliable environment. These problems are the primary obstacles to be removed. Previous studies focus their attentions on how to eliminate domino-effect dynamically. But backward error recovery cannot be applied directly in parallel real time systems even under the condition that no domino-effect exists. How to reduce output delays efficiently if no domino-effect remains? How to estimate this delay time? How to calculate the actual execution time of every process and how to schedule these processes under an unstable condition? These problems were omitted in literature unfortunately. The interest of this paper is to provide satisfactory solutions to these problems to make it possible to adopt backward error recovery efficiently in parallel real time systems.

Robust Adaptive Actuator Failure Compensation for a Class of Uncertain Nonlinear Systems

This paper presents a robust adaptive state feedback control scheme for a class of parametric-strict-feedback nonlinear systems in the presence of time varying actuator failures. The designed adaptive controller compensates a general class of actuator failures without any need for explicit fault detection. The parameters, times, and patterns of the considered failures are completely unknown. The proposed controller is constructed based on a backstepping design method. The global boundedness of all the closed-loop signals is guaranteed and the tracking error is proved to converge to a small neighborhood of the origin. The proposed approach is employed for a two-axis positioning stage system as well as an aircraft wing system. The simulation results show the correctness and effectiveness of the proposed robust adaptive actuator failure compensation approach.

Decision-Aided Extended Kalman Filter Based Adaptive Timing Recovery for Wavelet Packet Modulated Signals

One of the major issues with multi-carrier systems is their vulnerability to timing synchronization errors resulting in the loss of time synchronization which causes loss of orientation of incoming data at the receiver. This paper presents an acquisition algorithm to timing recovery using the decision-aided extended Kalman filtering （EKF） technique for nonlinear disturbance channels in a wavelet packet transform-based multicarrier modulation communication system. This timing recovery algorithm gives faster convergence, smaller root mean square （RMS） errors, and better bit error rate （BER） performance than traditional timing recovery methods, such as the phase-locked loop （PLL）, maximum likelihood （ML）, and Kalman filter （KF） methods. Thus, the algorithm is able to handle larger timing errors more reliably and to provide better timing recovery, since the scheme takes into account the nonlinear relationship between the signal samples and timing errors. Simulations for various time-varying channels show that the timing recovery algorithm works well for wavelet packet transform-based multicarrier modulation communication systems.