Showing papers in "IEEE Transactions on Circuits and Systems Ii-express Briefs in 2018"
TL;DR: It is shown that bipartite tracking consensus in the close-loop MAS can be achieved if the gain matrix of protocol is suitably constructed and the control parameters of protocol are, respectively, larger than some positive quantities depending on global information of the considered MAS.
Abstract: In this brief, the distributed bipartite tracking consensus problem for linear multi-agent systems (MASs) in the presence of a single leader is investigated. Compared with some related works on this topic, the leader’s control inputs in the present MAS model are allowed to be nonzero and unknown to each follower. To guarantee bipartite tracking consensus, a new kind of distributed non-smooth protocols based on the relative state information of neighboring agents are proposed and analyzed. With the help of tools from Lyapunov stability theory and graph theory, it is shown that bipartite tracking consensus in the close-loop MAS can be achieved if the gain matrix of protocol is suitably constructed and the control parameters of protocol are, respectively, larger than some positive quantities depending on global information of the considered MAS. To provide some efficient criteria for consensus seeking without involving any global information, some fully distributed protocols with adaptive control parameters are further designed and discussed. Finally, numerical simulations are given for illustration.
231 citations
TL;DR: A novel model to investigate the cascading failures in interdependent power grids and communication networks is proposed, and the robustness of an interdependent system composed of an Internet AS-level network and the IEEE 118 Bus is assessed.
Abstract: In this brief, by considering realistic network operational settings, we propose a novel model to investigate the cascading failures in interdependent power grids and communication networks We perform a critical node analysis on single networks to identify the vital nodes from the perspective of network robustness Moreover, we assess the robustness of an interdependent system composed of an Internet AS-level network and the IEEE 118 Bus Our simulation results show that assortative coupling of node destructiveness is more robust for densely coupled networks, whereas disassortative coupling of node robustness and node destructiveness performs better for sparsely coupled cases
222 citations
TL;DR: Simulation results of IEEE 30-bus and IEEE 57-bus test cases show that the key nodes can be effectively identified with high electrical centrality and resultant cascading failures that eventually lead to a severe decrease in net-ability, verifying the correctness and effectiveness of the analysis.
Abstract: The analysis of blackouts, which can inevitably lead to catastrophic damage to power grids, helps to explore the nature of complex power grids but becomes difficult using conventional methods This brief studies the vulnerability analysis and recognition of key nodes in power grids from a complex network perspective Based on the ac power flow model and the network topology weighted with admittance, the cascading failure model is established first The node electrical centrality is further pointed out, using complex network centrality theory, to identify the key nodes in power grids To effectively analyze the behavior and verify the correctness of node electrical centrality, the net-ability and vulnerability index are introduced to describe the transfer ability and performance under normal operation and assess the vulnerability of the power system under cascading failures, respectively Simulation results of IEEE 30-bus and IEEE 57-bus test cases show that the key nodes can be effectively identified with high electrical centrality, the resultant cascading failures that eventually lead to a severe decrease in net-ability, verifying the correctness and effectiveness of the analysis
168 citations
TL;DR: In this paper, a scalable high performance depthwise separable convolution optimized CNN accelerator is proposed, which can fit into an FPGA of different sizes, provided the balancing between hardware resources and processing speed.
Abstract: Convolutional neural networks (CNNs) have been widely deployed in the fields of computer vision and pattern recognition because of their high accuracy. However, large convolution operations are computing intensive and often require a powerful computing platform such as a graphics processing unit. This makes it difficult to apply CNNs to portable devices. The state-of-the-art CNNs, such as MobileNetV2 and Xception, adopt depthwise separable convolution to replace the standard convolution for embedded platforms, which significantly reduces operations and parameters with only limited loss in accuracy. This highly structured model is very suitable for field-programmable gate array (FPGA) implementation. In this brief, a scalable high performance depthwise separable convolution optimized CNN accelerator is proposed. The accelerator can be fit into an FPGA of different sizes, provided the balancing between hardware resources and processing speed. As an example, MobileNetV2 is implemented on Arria 10 SoC FPGA, and the results show this accelerator can classify each picture from ImageNet in 3.75 ms, which is about 266.6 frames per second. The FPGA design achieves 20x speedup if compared to CPU.
150 citations
TL;DR: By employing the techniques from nonsmooth analysis, it is proved that all agents can be guaranteed to asymptotically reach bipartite consensus for any logarithmic quantizer accuracy under connected and structurally balanced topology.
Abstract: This brief deals with the consensus problem in a network of agents with cooperative and antagonistic interactions subject to quantization. By employing the techniques from nonsmooth analysis, we prove that all agents can be guaranteed to asymptotically reach bipartite consensus for any logarithmic quantizer accuracy under connected and structurally balanced topology and the states of all agents asymptotically converge to zero under connected and structurally unbalanced topology. In addition, finite-time bipartite consensus is considered for single-integrator agents with binary quantized information. The simulation results are given to demonstrate the effectiveness of the theoretical results.
143 citations
TL;DR: A fast yet energy-efficient reconfigurable approximate carry look-ahead adder that has the ability of switching between the approximate and exact operating modes making it suitable for both error-resilient and exact applications is proposed.
Abstract: In this brief, we propose a fast yet energy-efficient reconfigurable approximate carry look-ahead adder (RAP-CLA). This adder has the ability of switching between the approximate and exact operating modes making it suitable for both error-resilient and exact applications. The structure, which is more area and power efficient than state-of-the-art reconfigurable approximate adders, is achieved by some modifications to the conventional carry look ahead adder (CLA). The efficacy of the proposed RAP-CLA adder is evaluated by comparing its characteristics to those of two state-of-the-art reconfigurable approximate adders as well as the conventional (exact) CLA in a 15 nm FinFET technology. The results reveal that, in the approximate operating mode, the proposed 32-bit adder provides up to 55% and 28% delay and power reductions compared to those of the exact CLA, respectively, at the cost of up to 35.16% error rate. It also provides up to 49% and 19% lower delay and power consumption, respectively, compared to other approximate adders considered in this brief. Finally, the effectiveness of the proposed adder on two image processing applications of smoothing and sharpening is demonstrated.
135 citations
TL;DR: A new class of finite-time consensus controller is designed for second-order multi-agent systems subject to input saturation with only a single saturation function involved, which distinguishes it from the previous ones.
Abstract: In this brief, a new class of finite-time consensus controller is designed for second-order multi-agent systems subject to input saturation. Only a single saturation function is involved in the proposed controller, which distinguishes it from the previous ones. The proposed controllers achieve finite-time consensus using only relative state measurements. Both leaderless and leader-following consensus problems are studied. Comparisons of the proposed controllers with other existing controllers are shown through simulation examples.
89 citations
TL;DR: The purpose is to synthesize an OF controller, which ensures that the closed-loop system is mean-square $\sigma $ -error stable, and some sojourn time-dependent criteria are established for the realizability of admissible OF controller.
Abstract: This brief is concerned with the problem of quantized output feedback (OF) control for semi-Markov jump systems subject to unreliable links. The jump among the operation modes is subject to the semi-Markov process, where the transition probabilities depend not only on the next system mode but the sojourn time at current mode as well. The communication link is considered to be unreliable, in which the packet dropouts described by a stochastic Bernoulli parameter and signal quantization are taken into account simultaneously. The purpose is to synthesize an OF controller, which ensures that the closed-loop system is mean-square $\sigma $ -error stable. Some sojourn time-dependent criteria are established for the realizability of admissible OF controller. With the help of those criteria, the controller gains could be obtained by finding a solution to a convex optimization problem. Finally, both a numerical example and a PWM-driven boost converter are presented to confirm the availability and feasibility of the proposed approach.
86 citations
TL;DR: A novel non-isolated three-port converter (NITPC) is introduced in this brief, which is a compact but fully functional design by combining and integrating basic converters to form a simplified single-inductor converter structure while keeping a minimum amount of switches.
Abstract: A novel non-isolated three-port converter (NITPC) is introduced in this brief. The purpose of this topology is to integrate a regenerative load such as DC bus and motor with dynamic braking, instead of the widely reported consuming load, with a photovoltaic (PV)-battery system. Conventional methods require either a separate DC–DC converter to process the reversible power flow or employing an isolated three-port converter (TPC), which allows bi-directional power flow between any two ports. However, these methods require many switches, which increases the converter size and control complexity. This brief hence presents a compact but fully functional design by combining and integrating basic converters to form a simplified single-inductor converter structure while keeping a minimum amount of switches. The resultant converter is fully reconfigurable that all possible power flow combinations among the sources and load are achieved through different switching patterns, while preserving the single power processing feature of TPC. This brief presents a design example of the proposed NITPC for a PV-battery powered DC microgrid. Detailed circuitry analysis, operation principles of both DC grid-connected and islanded modes, and experimental results of different modes in steady state and mode transitions are presented.
84 citations
TL;DR: A fully integrated implementation of a parallel fractional-order resonator that employs together a fractionalThe design utilizes current-controlled operational transconductance amplifiers as building blocks, designed, and fabricated in AMS.
Abstract: A fully integrated implementation of a parallel fractional-order resonator that employs together a fractional-order capacitor and a fractional-order inductor is proposed in this brief. The design utilizes current-controlled operational transconductance amplifiers as building blocks, designed, and fabricated in AMS ${0.35{-}\mu {\mathrm{ m}}}$ CMOS process and based on a second-order approximation of a fractional-order differentiator/integrator magnitude optimized in the range 10 Hz–700 Hz. An attractive benefit of the proposed scheme is its electronic tuning capability.
81 citations
TL;DR: The BSI DAVis achieves a peak QE of 93% compared with the FSI DAVIS, peakQE of 24%, but reduced MTF, due to pixel crosstalk and parasitic photocurrent, and effects of parasites photocurrent and modulation transfer functions with and without IR cut filters are reported.
Abstract: Back side illumination has become standard image sensor technology owing to its superior quantum efficiency and fill factor. A direct comparison of front and back side illumination (FSI and BSI) used in event-based dynamic and active pixel vision sensors (DAVIS) is interesting because of the potential of BSI to greatly increase the small 20% fill factor of these complex pixels. This brief compares identically designed front and back illuminated DAVIS silicon retina vision sensors. They are compared in term of quantum efficiency (QE), leak activity and modulation transfer function (MTF). The BSI DAVIS achieves a peak QE of 93% compared with the FSI DAVIS, peak QE of 24%, but reduced MTF, due to pixel crosstalk and parasitic photocurrent. Significant “leak events” in the BSI DAVIS limit its use to controlled illumination scenarios without very bright light sources. Effects of parasitic photocurrent and modulation transfer functions with and without IR cut filters are also reported.
TL;DR: A stochastic model based on state transition theory is proposed to investigate the dynamics of cascading failures in communication networks and reveals the effects of the initial failure pattern, community structure and network design parameters on the dynamic propagation of cascades failures.
Abstract: In this brief, we propose a stochastic model based on state transition theory to investigate the dynamics of cascading failures in communication networks. We describe the failure events of the nodes in the network as node state transitions. Taking a probabilistic perspective, we focus on two uncertain conditions in the failure propagation process: which node in the network will fail next and how long it will last before the next node state transition takes place. The stochastic model gives each overloaded element a probability of failing, and the failure rate is relevant to the degree of overloading. Moreover, the time dimension is considered in the stochastic process, by removing a node after a time delay when its traffic load exceeds its capacity. We employ this proposed model to study the dynamics of cascading failure evolution in a Barabasi–Albert scale-free network and an Internet AS-level network. Simulation results reveal the effects of the initial failure pattern, community structure and network design parameters on the dynamic propagation of cascading failures.
TL;DR: A new method based on autocorrelation to measure the RR and HR using IR-UWB radar with high accuracy and variational mode decomposition algorithm is adopted to successfully separate the respiration and heartbeat signals.
Abstract: Respiration rate (RR) and heartbeat rate (HR) are important physiological parameters for a person. Impulse radio ultra-wideband (IR-UWB) is a promising technology for non-contact sensing and monitoring. This brief presents a new method based on autocorrelation to measure the RR and HR using IR-UWB radar. The correlation coefficient waveform contains the vital sign signals, overcoming the effect of noise and clutter. Applying fast Fourier transform, the respiration frequency can be acquired easily. A clever method also based on autocorrelation is proposed to locate the subject. The receive signal matrix is divided into a set of bins in the direction of fast time. By removing one block from the matrix each time and re-applying the autocorrelation, the removed block resulting the smallest correlations is corresponding to the location of a subject. Moreover, variational mode decomposition algorithm is adopted to successfully separate the respiration and heartbeat signals. Experiments are carried out using a PulsOn410 UWB radar. The results show that the proposed low-complexity algorithm has high accuracy.
TL;DR: It is proved that the formation errors are uniformly bounded and can converge to an adjustable small neighborhood of zero by the proposed continuous protocol under the influences of actuator failures.
Abstract: This brief investigates the distributed fault-tolerant time-varying formation control problems for second-order multi-agent systems with directed interaction topologies in the presence of both bias and loss of effectiveness actuator failures. Using the adaptive updating mechanism and the boundary layer theory, a continuous fault-tolerant formation control protocol is constructed to compensate for the actuator failures and the derivative of the time-varying formations. The proposed protocol is totally distributed without requiring any global knowledge about the interaction topologies or the bounds of the actuator failures. The formation feasible condition is provided, and it is proved that the formation errors are uniformly bounded and can converge to an adjustable small neighborhood of zero by the proposed continuous protocol under the influences of actuator failures.
TL;DR: This brief proposes a fifth-order Butterworth operational transconductance amplifier-C (OTA-C) low-pass filter (LPF) with multiple-output differential-input (MODI) OTA structure and metal–insulator–metal capacitors for electrocardiography applications.
Abstract: This brief proposes a fifth-order Butterworth operational transconductance amplifier-C (OTA-C) low-pass filter (LPF) with multiple-output differential-input (MODI) OTA structure and metal–insulator–metal capacitors for electrocardiography applications. The current division technology is used as an alternative output pair to provide multiple outputs and achieve high linearity. This technique reduces the number of OTAs of the fifth-order LPF from 11 to 6 as compared with the conventional structure. The design issue of linearity is also considered in the implementation of MODI OTA. The proposed filter is fabricated in a 0.18 ${\mu }\text{m}$ complementary metal–oxide–semiconductor technology with an area of 0.12 mm2. The LPF achieved a total harmonic distortion of 49.8 dBc under a bandwidth of 50 Hz and input voltage of 86 mV $_\text{pp}$ at a 1-V supply voltage. The total power dissipation is 350 nW.
TL;DR: This brief proposes a novel locally active memristor based on a voltage-controlled genericmemristor model and uses the analysis methods of standard nonlinear theory to analyze its characteristics and illustrates the concept of local activity via the dc v-i loci of memristors and non-volatile memory via the power-off plot of mem Bristor.
Abstract: In this brief, we propose a novel locally active memristor based on a voltage-controlled generic memristor model and use the analysis methods of standard nonlinear theory to analyze its characteristics and illustrate the concept of local activity via the dc v-i loci of memristor and non-volatile memory via the power-off plot of memristor. A chaotic attractor is observed with a simple nonlinear circuit that only includes three circuit elements in parallel: 1) a nonlinear locally active memristor; 2) a linear passive inductor; and 3) a linear passive capacitor. Then, we analyze the dynamical characteristics of the above circuit and show complex bifurcation behaviors.
TL;DR: The analytical (closed-form) extraction process for the transmission poles and zeros of the proposed dual-band BPF is presented based on the rigorous scattering-parameters theory and the even- and odd-mode analysis method.
Abstract: A simple and planar design structure for dual-band bandpass filter (BPF) with multiple transmission poles and zeros is proposed in this brief. According to frequency response transformation, two passbands are realized on both sides of the operation frequency. Sharp selectivity and high isolation level with eight transmission poles and seven transmission zeros are achieved just by employing three-section coupled lines and three short-circuit stubs. Besides, the analytical (closed-form) extraction process for the transmission poles and zeros of the proposed dual-band BPF is presented based on the rigorous scattering-parameters theory and the even- and odd-mode analysis method. A prototype for the dual-band BPF with 3-dB fractional bandwidth of 41.1% and 19.0% is designed and fabricated. The measured and simulated results are in good agreement to verify the validity of the proposed design principle.
TL;DR: The modeling and experimental validation of a capacitive link as an emerging strategy for wireless power transfer to biomedical implants and in very good agreement with simulation results from the related circuit model is reported.
Abstract: This brief reports on the modeling and experimental validation of a capacitive link as an emerging strategy for wireless power transfer to biomedical implants. The capacitive link comprises two pairs of coated parallel plates that are placed at a distance of ${L}$ apart, with a tissue layer acting as the dielectric material. A series-resonant structure is then formed by placing two inductors in series with the capacitive link. A comprehensive circuit model is proposed that accounts for the ${L}$ -dependent, parasitic, cross-coupled, and longitudinal resistive elements contributed by the tissue between the two pairs. The series-resonant capacitive link is also realized with 400-mm $^{2}$ capacitive pads on printed-circuit boards that are coated with a 1- $\mu \text{m}$ -thick layer of Parylene- ${N}$ , aligned around a 5-mm-thick tissue layer, and placed in series with two 100- $\mu \text{H}$ inductors, resulting in resonance frequencies of ~115 and 127 kHz. At an operation frequency of 120 kHz and over a wide range of load resistance from $10~\Omega $ to 100 $\text{k}\Omega $ , the effect of ${L}$ on the power delivered to the load and power transfer efficiency parameters of the link is measured from 2 cm to $\infty $ and shown to be in very good agreement with simulation results from the related circuit model.
TL;DR: This brief presents a design procedure of a compact 33-GHz low-noise amplifier (LNA) for fifth generation (5G) applications realized in 28-nm LP CMOS, with emphasis on the optimization of design and layout techniques for active and passive components in the presence of rigorous metal density rules and other back-end-of-the-line challenges.
Abstract: This brief presents a design procedure of a compact 33-GHz low-noise amplifier (LNA) for fifth generation (5G) applications realized in 28-nm LP CMOS. Based on the unique set of challenges presented by advanced nanoscale CMOS, the emphasis is put here on the optimization of design and layout techniques for active and passive components in the presence of rigorous metal density rules and other back-end-of-the-line challenges. All passive components are designed and optimized with full-wave electromagnetic simulations for a high quality factor. In addition, layout techniques help to miniaturize the total area as the suggested 5G frequency band of 33 GHz is not high enough to provide a sufficiently compact chip size. The resulting increase in the concentration of required metal fills furthermore makes this optimization more challenging. The fabricated LNA consists of two cascode stages with a total core area of $0.68{\times }0.34$ mm2. It exhibits 4.9-dB noise figure and 18.6-dB gain at 33 GHz while consuming only 9.7 mW from a 1.2-V power supply.
TL;DR: This brief presents a fixed-time disturbance observer for Brunovsky systems that can achieve exact disturbance estimation within finite time upper bounded by a constant independent of initial estimation error.
Abstract: This brief presents a fixed-time disturbance observer for Brunovsky systems The proposed disturbance observer is composed of a uniform convergent part and a finite time convergent part The uniform convergent part first drives the estimation error trajectories into a compact set containing the origin and then the finite time convergent part achieves exact disturbance estimation The proposed disturbance observer can achieve exact disturbance estimation within finite time upper bounded by a constant independent of initial estimation error In addition, the upper bound of the estimation time can be calculated theoretically Numerical simulations are provided to demonstrate the effectiveness of the proposed disturbance observer and verify the declared fixed-time property
TL;DR: A compact dual-band impedance matching network is introduced and applied to the design of rectifying circuits and theoretical analysis is carried out and closed-form design formulas are derived.
Abstract: In this brief, a compact dual-band impedance matching network is introduced and applied to the design of rectifying circuits. The matching network can work at two arbitrary frequencies with arbitrary complex impedance simultaneously. Theoretical analysis is carried out and the closed-form design formulas are derived. For validation, a dual-band rectifier working at 0.915 and 2.45 GHz is implemented. The measured maximum RF-to-dc efficiencies are 77.2% and 73.5% at 0.915 and 2.45 GHz, respectively.
TL;DR: An improved pulse-width-modulation-based sliding-mode (SM) controller for the regulation of a 2-stage dc–dc cascade boost converter and the derivation of equivalent control signal and the stability analysis of the closed-loop system are presented.
Abstract: This brief presents an improved pulse-width-modulation-based sliding-mode (SM) controller for the regulation of a 2-stage dc–dc cascade boost converter The main drawback of the existing SM controller is that its use in the regulation of the high-order dc–dc converter results in a trade-off between the overshoot and speed of the transient output response In order to overcome this problem, the sliding surface of the proposed SM controller is designed such that the integral action in the resulting equivalent control signal is based on the normalized output voltage error of the converter Also, the derivative of the integrand is bounded by a user defined constant The derivation of equivalent control signal of the proposed SM controller and the stability analysis of the closed-loop system are presented Finally, an experimental comparative study involving the proposed and existing SM controllers is provided
TL;DR: Theoretical analysis and performance comparison show that the proposed topology of a novel rectifier with power recycling based on a branch-line coupler features recycling ability within a wide input power range.
Abstract: In this brief, a novel rectifier with power recycling based on a branch-line coupler is proposed to operate within a wide input power range. In the proposed topology, two output ports of the coupler are connected with two subrectifiers dealing with higher power level (main branches), while the isolation port is connected with the subrectifier dealing with lower power level (power recycling branch). By using the branch-line coupler, the power reflected from the two main branches can be efficiently transmitted to the power recycling branch. Consequently, the power can be reused and thus the RF-dc conversion efficiency can be improved. In this way, the rectifier can maintain high efficiency in a wide input power range. Theoretical analysis and performance comparison are carried out, which show that the proposed topology features recycling ability within a wide input power range. For validation, a rectifier working at 2.45 GHz is implemented and compared to other designs. The measured efficiency remains over 50% from 8.5 to 32.5 dBm, indicating that high efficiency can be obtained within wide input power range.
TL;DR: This brief presents an energy efficient wideband low noise amplifier (LNA) operating in subthreshold regime using a gate inductor-assisted impedance matching and a current reuse feed-forward noise cancelation technique, respectively.
Abstract: This brief presents an energy efficient wideband low noise amplifier (LNA) operating in subthreshold regime. Wideband matching and low noise figure in subthreshold domain is achieved by using a gate inductor-assisted impedance matching and a current reuse feed-forward noise cancelation technique, respectively. Fabricated in UMC 0.18- $ {\mu }\text{m}$ CMOS technology, the proposed LNA draws 1 mA from 1.8-V supply and achieves a voltage gain of 13 dB (taking into account a 8 dB loss in buffer), minimum noise figure ( ${\text {NF}}_{\text {min}}$ ) of 6 dB, and 3 dB bandwidth from 2 to 5 GHz.
TL;DR: The theoretical foundations of the engineered balanced filter approach, along with guidelines to design the differential-mode transfer function and to attain optimum in-band common-mode power-attenuation characteristics, are expounded.
Abstract: A new type of RF $/$ microwave differential-mode planar multiband bandpass filters (BPFs) are presented. Each symmetrical half of the proposed balanced filtering architecture is composed of the in-series cascade of $K$ $N$ -stub-loaded cells through $K-1$ inter-connection transmission-line segments to synthesize a differential-mode transfer function with $N$ $K$ th-order passbands. Additional features of this balanced multiband BPF topology are as follows: 1) generation of transmission zeros at both sides of all differential-mode passbands; 2) high common-mode power-rejection levels within the differential-mode passband ranges; 3) scalability to any number of arbitrary-order differential-mode transmission bands; and 4) lack of electromagnetic couplings in its physical structure. The theoretical foundations of the engineered balanced filter approach, along with guidelines to design the differential-mode transfer function and to attain optimum in-band common-mode power-attenuation characteristics, are expounded. Furthermore, for experimental-demonstration purposes, a third-order triple-band microstrip prototype with differential-mode passbands that are located within the range 1.4–3 GHz is manufactured and characterized.
TL;DR: This brief concerns a general cooperative–competitive network with weighted interactions, based on which the cluster consensus problem is addressed, and simulations are presented to verify the theoretical results.
Abstract: This brief concerns a general cooperative–competitive network with weighted interactions, based on which the cluster consensus problem is addressed. A directed network with the weighted cooperative–competitive interactions is classified into three categories: 1) interactively balanced; 2) sub-balanced; and 3) unbalanced digraphs. In interactively balanced or sub-balanced networks, cluster consensus can be achieved, while in interactively unbalanced networks, cluster consensus can be reached in need of additional control inputs exerted on specific pinned agents. Simulations are finally presented to verify the theoretical results.
TL;DR: The optimal high-pass filter section parameters that cover six frequency decades are obtained using the flower pollination algorithm while the effect of the number of filter sections on the accuracy of the approximation is investigated.
Abstract: A new approximation method of the fractional-order Laplacian operator ${s}^{\alpha }$ is introduced. The approximation is based on a weighted sum of first-order filter sections and its analytical proof is given. The optimal high-pass filter section parameters that cover six frequency decades are obtained using the flower pollination algorithm while the effect of the number of filter sections on the accuracy of the approximation is investigated. Approximations of fractional-order capacitors of orders ${\alpha =0.5}$ and ${\alpha =0.7}$ synthesized in Foster-II form are given as a validating example. Further, an active emulator of a fractional-order differentiator function based on this technique is also proposed and experimentally validated.
TL;DR: It is shown that the positive consensus can be achieved with the combined effect of edge dynamics, the number of edges, and the minimum diagonal element of the Perron matrix of line graph.
Abstract: This brief addresses the positive consensus of the edges with multi-input and multi-output positive dynamics for undirected and directed networks. The line graph is derived from the given nodal graph to represent the interaction of the edges, and the discrete-time positive systems are introduced to describe the edge dynamics. Based on the positive system theory and consensus analysis, a necessary and sufficient condition for positive edge-consensus is established, which reveals how the edge dynamics and the eigenvalues of the Perron matrix of line graph affect the consensus. Moreover, with further analysis, sufficient conditions for positive edge-consensus are derived without using the global interaction topology. It shows that the positive consensus can be achieved with the combined effect of edge dynamics, the number of edges, and the minimum diagonal element of the Perron matrix of line graph. The feedback matrix can be computed by solving linear programming problem. Finally, the simulations explicitly verify the proposed theoretical results.
TL;DR: This brief presents an MOS-only voltage reference circuit with high-slope proportional-to-absolute-temperature (PTAT) voltage generators for ultra-low-power applications and shows that much power and chip area can be saved.
Abstract: This brief presents an MOS-only voltage reference circuit with high-slope proportional-to-absolute-temperature (PTAT) voltage generators for ultra-low-power applications. Biased by a nano-ampere current reference circuit, the PTAT voltage generator is realized by an asymmetrical differential cell with two additional cross-coupled nMOS/pMOS pairs, which enhance the slope of the PTAT voltage remarkably. As a result, only two cascaded PTAT stages are used to compensate the complementary-to-absolute-temperature voltage generated directly by a diode-connected nMOS in the current reference circuit. Therefore, much power and chip area can be saved. A trimming circuit is also adopted to compensate the process-related reference voltage variations. The experimental results of the proposed reference circuit fabricated in a 0.18- $ {\mu }$ m standard CMOS process demonstrate that the circuit could operate under a minimum supply voltage of 1 V, and generate a reference voltage of 756 mV with temperature coefficient of 74 and 49.6 ppm/°C under 1-V and 1.8-V power supply, respectively. The proposed circuit consumes only 23 nA under a 1-V power supply, and the active area is only 95 $ {\mu }\text{m}\,\, {\times } \,\, 170 ~{\mu }\text{m}$ .
TL;DR: A constrained adaptive filtering algorithm under MEE criterion is proposed, called CMEE, which is derived by incorporating a set of linear equality constrains into MEE to handle a constrained MEE optimization problem.
Abstract: Minimum error entropy (MEE), as a robust adaption criterion, has received considerable attention due to its broad applicability, especially in the presence of non-Gaussian noises. In this brief, we propose a constrained adaptive filtering algorithm under MEE criterion, called CMEE, which is derived by incorporating a set of linear equality constrains into MEE to handle a constrained MEE optimization problem. In addition, convergence analysis of the proposed CMEE including the stability and steady-state mean square deviation is studied. Simulation results validate the theoretical conclusions, and confirm the effectiveness of the new algorithm in non-Gaussian noises.