Additional Zeros Research Articles

New Seamless Switching Control Technique Between CCM and DCM for Boost PFC Without Additional Zero Crossing Point Sensing Circuit

New Seamless Switching Control Technique Between CCM and DCM for Boost PFC Without Additional Zero Crossing Point Sensing Circuit

Examining across year genotype by environment interactions for production and reproduction traits in Merino sheep

Variation in feed resource availability within production systems can cause genotype by environment interactions that change the ranking of the best animals to select between environments. Mediterranean environments have high variation in pasture growth between years that could cause genetic by environment interactions for sheep production traits. Therefore, we estimated heritabilities for live weight, fleece weight, fibre diameter and number of lambs weaned in six years from 2000 to 2005 and correlations between years comparing multivariate analysis and random regression analysis. We compared 3 methods: 1 multivariate analysis estimating (co)variances for traits in each year, 2 Random regression estimated (co)variances for intercept and slope for traits as repeated measurements fitted against average pasture growth in each year and 3. Random regression fitted against corrected average performance of animals in each year. Random regression was estimated with an order of polynomial of one for additive genetic variance and zero for permanent environmental effects. This combination of polynomials was the best fit based on Bayesian information criterion. We estimated heritabilities for each year and correlations between years using records from 3299 pedigreed Merino ewes managed at Katanning in Western Australia. There were 4651 records for adult live weight, 6750 for adult clean fleece weight, 6965 for adult fibre diameter, and 7774 for number of lambs weaned across all 6 years. Number of lambs weaned had more genotype by environment interactions than other traits, with fibre diameter and fleece weight having genotype by environment interactions between only a few years. Based on Bayesian information criterion values, multivariate analysis fit the data better for live weight, fleece weight and fibre diameter. Additionally, random regression estimated higher genetic correlations between years than multivariate analysis suggesting there was not enough flexibility in the random regression analysis, which used only first order polynomials, to fit differences between years. Pasture growth across years did not explain differences in performance for traits across years. Therefore, for number of lambs weaned, random regression using corrected average performance was a better fit than average pasture growth. For other traits, more years or a better indicator of variation in performance within and between years are required to use random regression for genotype by environment interactions.

Synthesis of the Control Algorithm for Third-Order Object Models with Additional Zero and Time Delay

In this paper, the tuning procedure for the standardized PID controller for third-order object models with additional zero and time delay using the maximum stability degree method with iteration is analyzed. Analytical calculation expressions for the tuning parameters of the controller were obtained as nonlinear functions of the argument - the degree of system stability, and linear functions of the known parameters of the object model. By varying the degree of stability, these functions are graphically constructed, after which, for the same argument value, sets of controller tuning parameter values are chosen, and the performances of the automatic control system for the control object are verified. The proposed method was compared with other known methods and tested for tuning the PID controller for the temperature control in the extruder of a 3D printer. The advantages of the elaborated procedure were highlighted.

Design and implementation of virtual-single-length turbo decoder for multi-user parallel decoding

Dealing with multiple users in cellular basestation with multiple codewords of variable length is a challenging task in parallel decoding. Thus, a novel turbo decoder with variable codeword-based parallel decoding is proposed for the 3GPP LTE (4G) system. To make multi-user decoding more efficient, all users are aggregated into a single block with zero insertions where all users can be decoded in the same cycle. Different users are separated by additional zeros to decode in parallel and improve the hardware utilization. Moreover, a stationary boundary enhancement is utilized to exchange and update the decoded messages between different sub-blocks of codeword for the next decoding interaction. This scheme can balance the performance loss and decoding latency of variable codeword-based parallel decoding. The proposed turbo decoder has a maximum throughput of 280.5 Mbps (VC707) and 212 Mbps (ZC706), where the design has been integrated and tested with OpenAirInterface (OAI) 4G eNB in campus trials.

The Strongly Coupled Resonator Quadruplet

A new structure, namely the strongly coupled resonator quadruplet (SCRQ), is presented in this article for the realization of compact pseudoelliptic evanescent mode filters. The SCRQ consists of a quadruplet of resonators, and it can be seen as the combination of a strongly coupled resonator triplet (SCRT) and a fourth resonator, the latter being exclusively coupled to the triplet by means of a regular coupling. Compared to the SCRT, which at the passband frequencies generates two poles and a transmission zero, the SCRQ generates an additional pole and an additional zero. The ability to locate the two zeros extremely close to both passband edges represents a unique feature of the SCRQ. The new structure is successfully validated by the experimental results of a manufactured 5th-order filter employing an SCRQ between two standard resonators.

Design of BPF-Integrated SPDT Switch Based on Slotline Resonators Loaded With Diodes

Slotline Stepped-impedance resonators (SIR) loaded with p-i-n diodes are used to develop bandpass filter (BPF) integrated switches in this brief. The loaded diodes are used to switch the resonant conditions of the short-ended slotline resonators. The equations for their resonant conditions under different loads at different locations are derived and discussed. With these derived equations, the switchable filters are designed and synthesized using the classical coupled-resonator filter theory. The design concept is demonstrated by a Cascaded Quadruplet (CQ) BPFintegrated single-pole single-throw (SPST) switch at center frequency f0 = 1 GHz with with 47.7 dB OFF-state suppression (OSS). Finally, two compact BPF-integrated single-pole double-throw (SPDT) switches are designed and fabricated. One of them combines source-load (S-L) coupling and introduces two additional zeros outside the desired passband to improve the frequency selectivity. The other on fractal common feeding line is developed to reduce the impact of accumulated residual admittances from OFFstate channels, which shows high roll-off rate of sidebands as well as high port-to-port isolation of 53.1 dB, and its overall circuit size is only 0.051 λg2.

Constrained profile estimation for distributed parameter system in one dimension using orthogonal collocation

Several industrial processes fall under the category of Distributed parameter systems (DPS) which are represented as coupled partial differential equations (PDEs). Obtaining accurate and physically meaningful profile estimates of states despite only a limited number of spatially distributed measurements, is a pre-requisite for adequately controlling such systems. In this work, we propose an online constrained state profile estimation approach for DPS. The approach is based on reduced-dimension model represented by differential and algebraic equations (DAE) which in turn is developed by discretization of the PDEs along the spatial coordinate using the orthogonal collocation (OC) method. A profile prediction error based approach is proposed for systematically fixing the dimension of the OC model to be used. Further, to compensate for the inevitable model plant mismatch (MPM) arising in the process of the dimensionality reduction, additive zero mean Gaussian white noise processes are introduced in both state dynamics as well as measurement model. Statistics of these noises are obtained based on simulation based realizations of approximation errors at collocation points and measurement locations. To incorporate the identified correlation between the resulting state and measurement noises in the estimation method, we propose a constrained DAE-EKF (extended Kalman Filter) extension to deal with such correlations. The estimation approach also involves an appropriately formulated optimization based update step to ensure constraint satisfaction over the entire spatial profile leading to physically meaningful state profile estimates. The constrained profile estimator is also integrated with an online moving window based parameter estimation, which enables tracking of both time varying parameters and state profiles. The efficacy of the proposed approach is demonstrated by conducting stochastic simulation studies using two tubular reactor systems. The results show that the proposed constrained online state estimation approach is able to obtain accurate profile estimates at low computational cost, while ensuring that the profile estimates satisfy the given constraints.

An effective controller design strategy for higher order systems

The recent methods that guarantee the stability of the reduced-order models are Mihailov stability, improved Pade approximation and truncation, improved generalized pole clustering, moment matching and salp swarm optimization. Further, these methods could overcome the limitations such as non-uniqueness, pole clustering, gain adjustment and difficulty to maintain the dominant roots in the lower order system for non-minimum higher order plants. This research emphasizes the design of the proposed compensating algorithm by using an additional open loop zero for the stable reduced-order models of large-scale single-input single-output linear time-invariant continuous time systems. The results of the proposed algorithm are compared with the existing compensating methods and the design is validated and illustrated numerically.

A Disturbance Decoupling Generalized Proportional–Integral Observer Design for Robust Sensor Fault Detection

This paper presents a novel disturbance decoupling generalized proportional-integral observer (DD-GPIO) for the early detection of sensor faults in dynamic systems subject to external semi-stationary periodic disturbances. The focus is to reduce the adverse impacts caused by the disturbance whose spectrum is uneven with some dominant frequencies. This achieved in a two-stage design procedure. In the first stage of zero-assignment, the additional zeros introduced by the state transition matrix of GPIO are allocated near the disturbance frequencies to construct a rank-deficient disturbance transfer function matrix (DFTM) relating from the disturbances to the fault detection residuals. In the second stage, an additional gain matrix is applied to the output estimation error before the error is fed into the GPIO. The additional matrix can be designed by using the eigenvector of zero eigenvalue of the rank deficient DFTM, such that the periodic perturbations can be completely decoupled from the fault detection residual for better performance in fault detection. The conditions to achieve disturbance decoupling is given. Finally, a novel condition number-based sensitivity objective is proposed to optimize the DD-GPIO's poles. Simulation and a two-wheeled robot experiment illustrate the outperformance of the DD-GPIO in decoupling periodic disturbances and detecting minor sensor faults.

Wideband High-Selective Linear Polarization Converter and Its Application in Bifunctional Metasurface for Reduced Isolation Band

In this article, a wideband high-selectivity filtering linear polarization converter is proposed and applied for ultranarrow isolation-band bifunctional metasurface. As the contribution of this work, the developed polarization converter based on slot-line loaded triangular resonator unit not only achieves the in-band multimode resonant characteristic, but also introduces two additional controllable zeros out-of-band, so as to enable simultaneous implementation of the wideband and high selectivity features. With the detailed analysis of the modes, field, and surface current distributions, the mechanisms of wideband, high selectivity, and polarization conversion are revealed. Finally, the linear polarization converter as well as the bifunctional metasurface are fabricated for demonstration. The linear polarization converter can attain a conversion bandwidth of 45% under a polarization conversion ratio of >90%. Due to the excellent filtering characteristic of the proposed linear polarization converter, the constructed bifunctional metasurface can reduce its isolation band to only 2.7%. As expected, the proposed converter has the attractive advantages of wideband operation and high selectivity, which are of great significance for reducing the isolation-band and improving the spectral utilization in various applications of multifunctional metasurfaces.

Patterned random matrices: deviations from universality

We investigate the level spacing distribution for three ensembles of real symmetric matrices having additional structural constraint to reduce the number of independent entries to only in contrast to the for a real symmetric matrix of size n × n. We derive all the results analytically exactly for the matrices and show that spacing distribution display a range of behaviour based on the structural constraint. The spacing distribution of the ensemble of reverse circulant matrices with additional zeros is found to fall slower than exponential for larger spacing while that of symmetric circulant matrices has poisson spacings. The palindromic symmetric Toeplitz matrices on the other hand show level repulsion but the distribution is significantly different from Wigner. The behaviour of spacings for all the three ensembles clearly show the departure from universal result of Wigner distribution for real symmetric matrices. The deviation from universality continues in large n cases as well, which we study numerically.

A Maximum Efficiency-86% Hybrid Power Modulator for 5G New Radio(NR) Applications

A hybrid power modulator is presented for the radio frequency (RF) power amplifiers of 5th generation mobile communication technology (5G) new radio (NR) applications. A hybrid power modulator utilizing a two-level switching converter and a broadband and high-efficiency linear amplifier is presented. A further improvement in the efficiency of the circuit is achieved by using an optimized supply voltage of the two-level switching converters of 4.5 V. In this way, the overall efficiency is improved by more than 5% compared to using a 5 V supply voltage. The linear amplifier consists of four stages. In order to improve bandwidth and circuit stability, a compensation circuit is added to the linear amplifier that eliminates the poles of the main amplifier by introducing additional zeros, indirectly pushing the pole distribution out of the bandwidth. Using this approach, the linear amplifier achieves a 3-dB bandwidth of 180 MHz and an efficiency of 51%. The hybrid power modulator achieves a maximum output power of 2.4 W and an efficiency of 86% when tracking a 100 MHz 5G-NR signal under a 4 Ω load in a 180 nm CMOS package.

An edge-based augmented system approach for second-order nodal consensus

Many works on multi-agent consensus protocol designs rely on the full states of nodes or the node- observer-based procedures, under both of which the nodal information plays a key role in the consensus design. In this paper, we propose an edge-based augmented system approach for second-order nodal consensus, based on the edge loop transfer matrix of the closed-loop multi-agent system, which is defined by cutting the loop at the inputs of the edges. Each agent is allowed to be of single-output and additional poles and zeros are introduced into edges to construct the channel filter with previous data stored in the memories. We firstly focus on the consensus design by reserving two terms of the non-recursive filter and then propose a simplified design approach exploiting a single parameter, which is of low complexity and can be readily implemented. We also discuss the consensus design by using the non-recursive channel filter with higher-order realizations. Finally, as an extension, we discuss the consensus design based on the first-order recursive channel filter. The effectiveness of the proposed method is verified by the illustrative simulations.

FREQUENCY FEATURES OF THE NUMERICAL METHOD SAMPLING OF DIGITAL CONTROL SYSTEMS

Context. The studies of the frequency properties of the explicit multistep numerical integrators which use for sampling of continuous transfer function in the digital control systems, are conducted in this article. Numerical integrators in such systems implement as an integral parts of the digital regulators. Objective. The goal of this research is an analysis of the behavior of explicit numerical integrators of different orders, which areused to discretize continuous systems, in order to study their impact on the properties of the synthesized digital system. Method. Numerical methods of integration are considered as digital filters, the behavior of which is studied by the frequency characteristics method. To do this, the z-transform apparatus was used. Integrators’ discrete transfer functions were found for frequency analysis using the Control Systems Toolbox package of the mathematical application MATLAB. For further analysis, two closed feedback test structures were used: with integrators in the forward channel and in the feedback loop. Both variants of structures were studied by the frequency characteristics method for sampling using numerical integrators of 1st–6th orders. Results. The inefficiency of using high-order numerical integrators for continuous systems’ discretization is shown. Given the behavior of the frequency characteristics of test systems, the most rational is the use of low-order integrators, namely – the first and second orders. Establishing the cause of this phenomenon requires additional research, in particular, to identify the possible impact of additional zeros and poles of discrete transfer functions of the numerical integrators. Conclusions. The use of low-order integrators, namely the first and second orders, is the most rational for sampling of digital control systems and the inefficiency of using high-order numerical integrators to sample continuous systems is proven.

Zero-assignment and complex coefficient gain design of generalized proportional-integral observer for robust fault detection

Aiming at early detection of faults in dynamic systems subject to external periodic disturbances, this paper proposes a new generalized proportional-integral observer (GPIO) fault detection scheme with zero-pole joint optimization and novel complex coefficient gain (CCG) of residual evaluation. The focus of the proposed scheme is to reduce the adverse impacts caused by the semi-stationary periodic disturbance whose spectrum is uneven, with most energy being at some dominant frequencies. The proposed GPIO with a complex coefficient gain is designed in a two-stage procedure. In the first stage of zero assignment and pole optimization, the additional zeros introduced by the GPIO’s integration action are allocated to near the disturbance frequency. The gain of the transfer function matrix relating from the disturbances to the fault indicator signals is minimized by pole optimization. In the second stage of designing complex coefficient gain in residual evaluation, the unique feature of rank-deficient caused by the additional zeros assigned in stage one is further exploited to cancel the disturbances in the fault indicator signals (which is also referred to as the fault detection residual in this article). It is proved that, for an arbitrary periodic disturbance with a specific spectrum, the remnant components of the disturbance in the indicator signals generated by the GPIO can cancel each other by a complex gain vector, which can be determined by the zero eigenvalue’s left eigenvector of the rank-deficient of the disturbance transfer function matrix. The sufficient conditions for the convergence of the proposed fault detection filter are also given. Numerical examples illustrate the proposed method’s better performance in detecting minor faults.

Ensuring stability of inverse functions and minimized models in MATLAB

Plotting of inverse functions of high-order models in MATLAB can generate positive zeros that distort the dynamic properties of the model. Minimizing the dimension of models with the "mineral" function in MATLAB significantly reduces the computation time, but creates additional zeros and generates positive poles, leading to instability of the model. Variants of constructing models with inverse functions and minimizing the dimension of models in MATLAB, which do not create additional zeros and poles, are proposed. Keywords: MATLAB, ADAMS software, inversion, minimization, dynamic model. v123std@mail.ru

Current Account Dynamics: On Income and Trade Balance

We investigate the dynamics of Japan's income and trade balance between 1996:Q1 and 2019:Q4 via a structural VAR model. The two most important constituents of the current account (trade balance and income balance) and seven other macroeconomic variables are entered in our VAR model. We implement a shadow rate for the measure of monetary policy under the unconventional monetary policy regime, including a zero lower bound interest rate. By using a standard SVAR model from the literature, we find that world shocks dominate and rule the dynamics of Japan's current account. Through additional short-run zero restrictions, we also find that exogenous exchange rate shocks affect the current account.

The geometry of Hermitian self-orthogonal codes

We prove that if n >k^2 then a k-dimensional linear code of length n over {mathbb F}_{q^2} has a truncation which is linearly equivalent to a Hermitian self-orthogonal linear code. In the contrary case we prove that truncations of linear codes to codes equivalent to Hermitian self-orthogonal linear codes occur when the columns of a generator matrix of the code do not impose independent conditions on the space of Hermitian forms. In the case that there are more than n common zeros to the set of Hermitian forms which are zero on the columns of a generator matrix of the code, the additional zeros give the extension of the code to a code that has a truncation which is equivalent to a Hermitian self-orthogonal code.

Novel control strategy for non-minimum-phase unstable second order systems: generalised predictor based approach

Abstract A control structure based on generalized predictor is proposed to control non-minimum phase unstable second order processes with time delay. The scheme contains a predictor structure and a direct synthesis method based primary controller for servo tracking. The predictor structure consists of two filters acting on input and current output which are designed to provide noise attenuation and disturbance rejection. A set-point filter minimises the overshoot caused by the introduction of additional zeros of the controller in the overall closed loop transfer function so as to smooth the tracking performance. Different second order unstable time delay systems are considered and Integral Absolute Error (IAE) and Total Variation (TV) measures are used for comparing the performances quantitatively. The method is implemented experimentally on an inverted pendulum. The proposed predictive strategy is found to provide enhanced control performances in comparison to the existing literature methods.

Design of Two-Stage Comb-Based Decimation Filter with High Aliasing Rejection and Low Passband Droop

This paper presents a simple method for the design of comb-based decimation filter with a high aliasing rejection and low passband droop. The method is based on the application of the mathematical result on zeros of symmetric polynomials on the unit circle. The application of this result leads to the introduction of the four additional single zeros into comb folding bands, where aliasing occur. As a result, the folding bands become wider and the aliasing rejection is increased. The passband droop is compensated by a simple compensator who works at low rate. The comparisons with the most recent methods from literature confirmed the advantages of this proposal regarding magnitude responses and the required complexity.