Ideal Filter Research Articles

Error rates of optically pre-amplified PPM wireless systems with coding and arbitrary optical filter response

We present novel results for the uncoded and coded bit-error probability (BEP) of optically pre-amplified pulse-position modulation (PPM) wireless systems. For uncoded systems, a novel analytic method for the evaluation of the BEP is derived. The method takes into account the non-ideal optical filter response and utilizes a finite Karhunen–Loève series expansion to calculate the BEP. Using the proposed approach, it is possible to accurately evaluate the PPM BEP for arbitrarily shaped filters where the well-established χ2 method only provides approximate results. Considering a Lorentzian filter response, the discrepancy between the two methods amounts to 0.5 dB in a variety of filter bandwidths and PPM modulation orders. The Lorentzian filter response was chosen as an illustrative practical example whose series can be calculated analytically. The proposed method is also valid for any type of optical filter for which the Karhunen–Loève series expansion can be calculated analytically or numerically. Due to the finite number of terms that are required irrespective of the signal energy level, the proposed method can also be applied without loss of accuracy to assess the system performance under the effects of turbulence and adverse weather conditions. For coded systems with Lorentzian filters, Monte-Carlo simulations are utilized to evaluate the BEP performance of the 5G LDPC codes, and it is demonstrated that they impart an energy gain up to 3.3 dB for 4–PPM and 2.3 dB for 16–PPM at a target BEP of 10−5. The optimal code rates are also discussed for several combinations of the optical filter bandwidth and PPM modulation order and it is shown that in almost all of the cases the optimal code rate is 11/13. Moreover, the sum-product and min-sum decoders perform within 0.1 dB from each other for the best code rates, which points towards the utilization of the min-sum decoder in all settings, since its operation does not require knowledge of the filter parameters. Finally, the comparison between the coded systems with Lorentzian and ideal passband filters exhibits the same 0.5 dB discrepancy that was observed for uncoded systems.

Study of the electrospun PVDF fibrous membrane in capturing particulate matters in smoke by the synergy between GO and CNWs

The filtration capability can be effectively adjusted by involving the incorporation of fillers into filter materials. Here, we present a promising filter material for capturing particulate matters in smoke, a polyvinylidene fluoride (PVDF) fibrous membrane modified by cellulose nanowhisker (CNWs) and graphene oxide (GO), which was prepared by a facile electrospinning method. GO with oxygen-containing groups can improve the capability of capturing particle owing to its excellent adsorption performance. CNWs with highly ordered crystalline regions can alter the dimension and properties of PVDF fibers. The synergistic effect of GO and CNWs enabled uniform fiber diameter, higher porosity, and better filtration property as compared with that of pristine PVDF membranes. Experimental results demonstrated a significant improvement in the filtration efficiency of PVDF fibrous membranes after blending with GO and CNWs. The filtration data showed that the filtration efficiency (95.58%) of GO/CNWs/PVDF membrane was higher than that (87.68%) of CNWs/PVDF membrane and that (86.36%) of PVDF membrane. The reusability for capturing pollutants showed that the fibrous membrane could keep a certain filtration capability (93.85%) after 5 cycles. Computational results suggested there was an interaction between GO and smoke pollutants (monoterpene) and the addition of GO play an effect on the filtration efficiency of fibrous membranes. These results showed that GO/CNWs/PVDF fibrous membranes was ideal filter materials for air pollutant.

Sparse FIR Filter Design using Double Generalized Orthogonal Matching Pursuit (DGOMP)

In this paper, sparse FIR filter was designed using Double Generalized Orthogonal Matching Pursuit (DGOMP) to reduce memory usage and increasing the speed thereby decreasing computational complexity of the algorithm. Mathematical models were formulated and simulations were conducted to validate the performance of the proposed method. The performance was compared with BOMP and Conventional FIR filter. The results showed that the DGOMP method achieved higher sparsity and a better approximation of an ideal filter. Additionally, the designed sparse FIR filters using DGOMP showed better performance in terms of time of execution when the signal lengths keep increasing, giving a 10% faster execution time when compared to BOMP. The passband and stopband attenuation, as well as ripple values were better, offering the flexibility of parameter adjustment. The results showed that DGOMP is a promising approach for designing sparse FIR filters.

A novel capacitive sensor interface based on a simple capacitance-to-phase converter

Abstract A novel room temperature capacitive sensor interface circuit is proposed and successfully tested, which uses a modified All-Pass filter architecture combined with a simple series resonant tank circuit with a moderate Q-factor. It is fashioned from a discrete inductor with small dissipation resonating with a grounded capacitor acting as the sensing element to obtain a resolution of ∆C ~ 2 zF in a capacitance range of 10 – 30 pF. The circuit converts the change in capacitance to the change in the phase of a carrier signal in a frequency range with a central frequency set up by the tank circuit’s resonant frequency and is configured to act as a close approximation of the ideal All-Pass filter. This cancels out the effects of amplitude modulation when the carrier signal is imperfectly tuned to the resonance. The proposed capacitive sensor interface has been specifically developed for use as a front-end constituent in ultra-precision mechanical displacement measurement systems, such as accelerometers, seismometers, gravimeters and gravity gradiometers, where moving plate grounded air gap capacitors are frequently used. Some other applications of the proposed circuit are possible including the measurement of the electric field, where the sensing capacitor depends on the applied electric field, and cost effective capacitive gas sensors. In addition, the circuit can be easily adapted to function with very small capacitance values (1 - 2 pF) as is typical in MEMS-based transducers.

Development of a procedure for fragmenting astronomical frames to accelerate high frequency filtering

The object of this study is the process of filtering astronomical frames that contain images of potential objects in the Solar System. To contour the image of each such object and recognize it in contrast with the background of the frame, it is necessary to filter the image. Most often, a variety of high-pass filters are used to determine the high-frequency component of the image, which can be removed as a coarse-grained component. Any image filtering is aimed at increasing the signal-to-noise ratio and reducing the dynamic range of the background image. However, the filtering process is quite resource- and time-consuming. This is especially true for systems for parallel processing of series of astronomical frames in real time (online). Therefore, to solve the problem of lack of frame fragmentation, which leads to high consumption of RAM, a procedure for fragmenting astronomical frames has been proposed. Owing to the introduction of a formal connection between the values of frame pixels and fragments, as well as determining their number, it was possible to reduce RAM utilization. Testing was carried out using the following high-pass filters ‒ ideal filter, Butterworth filter, and Gaussian filter. Using the devised procedure for fragmenting astronomical frames has made it possible to reduce the utilization of RAM during filtering. As a result, with parallel processing, this has also made it possible to speed up the high-frequency filtering procedure itself. The procedure devised for fragmenting astronomical frames was tested in practice within the framework of the CoLiTec project. It was implemented in the On-Line Data Analysis System (OLDAS) of the Lemur software. The study showed that when using the devised procedure, RAM utilization was reduced by 7–10 times. And the speed of filtration itself increased by 2–3 times. Accordingly, the processing time for each astronomical frame was reduced by 2–3 times

Improving spatiotemporal image fusion incorporating unmixing step by considering the point spread function effect

ABSTRACT In this paper, an improving spatiotemporal image fusion (STIF) incorporating unmixing step by considering the point spread function (PSF) effect model (CPSF) is proposed to address the problem that unmixing accuracy in STIF models incorporating unmixing step is vulnerable to the PSF effect. First, an unsupervised clustering algorithm is used to cluster the fine image at previous date into a land cover map, and the coarse class fraction matrix is generated from this land cover map. Second, the fine class fraction matrix uncontaminated by the PSF effect is calculated by upsampling the coarse class fraction matrix using the Area-to-Point Kriging (ATPK) method under the PSF constraint. Third, this fine class fraction matrix is convolved with the ideal square wave filter to downsample, and then normalized to obtain the coarse class fraction matrix without the influence of the PSF effect. Finally, the CPSF-processed class fraction matrix is used to replace the original one in the following unmixing and prediction process to generate the fine resolution image at the prediction date. Experiments on two remote sensing data sets show that the proposed method can effectively improve the accuracy of spatiotemporal image fusion methods incorporating unmixing step.

Devising a procedure for the brightness alignment of astronomical frames background by a high frequency filtration to improve accuracy of the brightness estimation of objects

The object of this study is the background substrate of astronomical frames. To detect and compare the image of an object in a frame with its real image from astronomical catalogs, it is necessary to uniformly distribute the brightness of the background image substrate. Most often, the background alignment of astronomical frames is performed using the hardware calibration method applying the construction of service frames. However, it does not make it possible to eliminate the background from temporary stray light. Therefore, to solve this problem, a procedure has been proposed for brightness alignment of the background frame using high-pass filtering. For high-pass filtering of images, three high-pass filters were considered – an ideal filter, a Butterworth filter, and a Gaussian filter. To remove coarse-grained image components from the image, a high-pass filter was used, which attenuates low-frequency harmonics of the image spectrum while simultaneously passing high-frequency harmonics. Applying the devised procedure for brightness alignment of the background substrate of the frame has made it possible to increase the signal-to-noise ratio and reduce the dynamic range of the background substrate of the image. The study showed that when assessing brightness and identifying frames, the fitting provides better accuracy of reference to the starry sky. Also, the standard deviation of frame identification errors in this case is 5–7 times less than without using the devised procedure. The devised procedure for brightness alignment of the background frame substrate was tested in practice within the framework of the CoLiTec project. It was implemented at the stage of intra-frame processing in the Lemur software for automated detection of new objects and tracking of known objects

Ideals and Filters on Neutrosophic Topologies Generated by Neutrosophic Relations

Recently, Milles and Hammami presented and studied the concept of a neutrosophic topology generated by a neutrosophic relation. As a continuation in the same direction, this paper studies the concepts of neutrosophic ideals and neutrosophic filters on that topology. More precisely, we offer the lattice structure of neutrosophic open sets of a neutrosophic topology generated via a neutrosophic relation and examine its different characteristics. Furthermore, we enlarge to this lattice structure the notions of ideals (respectively, filters) and characterize them with regard to the lattice operations. We end this work by studying the prime neutrosophic ideal and prime neutrosophic filter as interesting types of neutrosophic ideals and neutrosophic filters.

Fault-tolerant shunt active power filter with synchronous reference frame control and self-tuning filter

This research proposes a novel method that combines Proportional-Integral (PI) control, Artificial Neural Networks (ANNs), and Synchronous Reference Frame (SRF) theory to improve the performance of a three-phase shunt Active Power Filter (APF) under fault situations. The main goal is to reduce power quality problems in electrical grids that are having problems, such harmonics and voltage sags. To precisely manage the APF, the reference frame in which the grid voltages and currents are synchronized is identified using the SRF theory. In order to provide quick and precise correction of voltage and current distortions, the PI controller is integrated to control the APF's compensatory action. The PI controller offers trustworthy control while running normally, but during errors or disruptions, its functionality may suffer. In order to overcome this difficulty, a self-tuning filter in the form of an Artificial Neural Network (ANN) is presented, which may adaptively modify the PI controller's settings under fault situations. To maintain ideal filter performance, the ANN constantly learns from the system's reaction and modifies in real-time. This self-adjusting feature makes sure that even in the event of grid failures, the APF maintains its ability to mitigate problems with power quality. The suggested method effectively reduces harmonics, voltage sags, and other power quality disturbances under both normal and fault circumstances, as shown by the simulation results. In complicated electrical grid systems, the combination of SRF theory, PI control, and ANN-based self-tuning provides a strong way to improve the dependability and effectiveness of three-phase shunt Active Power Filters.

Nature inspired algorithm based design of near ideal fractional order low pass Chebyshev filters and their realization using OTAs and CCII

Fractional order filters offer greater freedom of design and a precise control over stopband attenuation in electronic circuits and systems. This paper presents the design of a fractional order low pass Chebyshev filter (FOLCF) that achieves near-ideal response characteristics. The methodology introduced utilizes metaheuristic optimization methods, including particle swarm optimization, firefly algorithm, and grey wolf optimization. These techniques are employed to precisely adjust the filter coefficients for the orders (1+α), (2+α), and (3+α). The adjustment is carried out by comparing the desired behaviour of the FOLCF with generalized fractional order low pass transfer functions. Throughout these instances, the parameter α is varied within the range of (0, 1). The designed filters are then tested and compared on the basis of various factors. Simulation results demonstrate that the designed filters closely follow the behaviour of an ideal Chebyshev filter with maximum passband and stopband magnitude errors being −31.93 dB and −52.74 dB respectively for (1+α) order filters. These values for (2+α) and (3+α) order FOLCF have been observed to be −30.04 dB and −55.91 dB; −17.72 dB and −49.52 dB respectively. Furthermore, it has been observed that the proposed work outperforms existing state-of-the-art approaches in various aspects, including magnitude error, stopband attenuation, and cut-off frequency. The stability of the designed filters has been verified through stability analysis. Additionally, practical feasibility of the proposed FOLCF is demonstrated through SPICE simulations for α = [0.2,0.5,0.8] using second generation current conveyor (CCII) and operational transconductance amplifier (OTA) based topologies while approximating the constant phase element using fifth order continued fraction expansion. The SPICE implementations closely follow the behaviour of ideal filter with −48.67 dB and −62.8 dB as mean square errors for CCII and OTA circuits respectively, showcasing the proposed filters' superiority and practical applicability in advanced electronic design.

Zeofilters for potentially innovative sunscreen products: formulation, stability and spectroscopic studies

Exposure to both UVA and UVB radiation from the sun stands as the primary cause of skin cancers, contributing to the escalating yearly count of diagnosed cases. Sunscreen products, (i.e. organic and inorganic UV filters) have become ubiquitous in personal-care products, packaging, plastics, dyes, and many other sectors. Ideal UV filters should be photostable and dissipate the absorbed energy efficiently. However, most organic UV filters are photolabile upon protracted UV exposure, leading to the formation of photoproducts of unknown toxicity for human health and environment. The chemical environment surrounding UV filters may strongly affect their behaviour: the interaction with other components of sunscreen formulations may enhance their degradation. Particularly, the interaction between photochemically incompatible ingredients must be avoided. Therefore, much effort has been invested in developing more effective and safe sunscreens.Our team recently focused on the preparation and characterization of hybrid UVfs obtained by the encapsulation of organic UV filters into various zeolites differing for topology. The zeolite most efficient for the encapsulation of organic UV filters, in term of stability and efficiency in radiation filtration, resulted to be LTL zeolite. Here, hybrid materials realized after the encapsulation of octinoxate (OMC) and avobenzone (AVO) in LTL zeolite were tested in terms of skin permeation profiles, cytotoxicity and photostability once the materials are dispersed in cream formulations, so to mimicking the real condition of use.The results show that the hybrids were successfully incorporated into oil-in-water emulsions and the skin permeation tests displayed a very low UV filter permeation through pig skin and no UV filter accumulation in dermis layer.The photostability of the hybrid-based emulsions were compared with that of emulsions containing a mixture of bare OMC and AVO, highlighting a reduced decrease in UV screening efficiency upon irradiation for the samples containing the hybrid materials with respect to the free filters. This evidence confirms that the encapsulation in the zeolite frameworks prevents some of the photodegradation reactions. The result of this paper highlights that zeolite encapsulation is increasingly establishing as a viable way to stabilize UV filters and other photoactive molecules.

PAPR reduction using polynomial based compressing with Rapp model in GFDM

Generalized Frequency Division Multiplexing (GFDM) has been considered as an attractive candidate to replace Orthogonal Frequency Division Multiplexing (OFDM) for the fifth generation (5 G) mobile networks. GFDM system has better spectral characteristics compared to the OFDM system due to the usage of properly selected pulse shaping filters. Non-causal ideal filters, such as the raised cosine (RC), are commonly used in the GFDM systems. Here, Generalized frequency division multiplexing is a promising candidate to deploy. However, as an intrinsic property of multi-carrier modulation, the high signal amplitude fluctuation can cause several degradation effects when the signal is affected by nonlinearities. The pulse shaping filters are designed using the computationally efficient quadratic programming (QP) approach. Therefore, the aim of this paper is to evaluate the performance of Generalized frequency division multiplexing systems undergoing nonlinear amplification. We evaluate the bit error ratio using high power amplifier, namely the Rapp model. The results show that the fault rate is apparently affected according to the particular high power amplifier model and its transmission parameters.

Feature Extraction and Classification of Gray-Scale Images of Brain Tumor using Deep Learning

Deep Learning using CNN plays a paramount role for the classification methods applied on medical image data. With a crucial role in accurate diagnosis, treatment planning and patient management for medical and healthcare systems, CNNs won accolades in the Deep Learning research. As simple the learning model so precise are the results for decision making. The proposed Sequential model of CNN is built with Parametric ReLU with the values aligned to geometric mean, attains a specific goal of tumor classification. The additional support of ground-truth aid in deciding the shape and severity of tumor in the Grayscale MRI of brain tumor. The simple Sequential model, although a minimal version has proved achieved significant classification goals using the GMP-ReLU. Comparative results with variants of ReLU have been charted in this article standing with the proof of consistent classification model with parametric-ReLU. The proposed design is conducted on images from Kaggle and a model is trained (classifier is built), which can be considered as ideal filter for all the benchmark images. The accuracy of proposed design is considerably improved compared to normal ReLU up to 89.214%.

Efficient Performance Analysis of Image Enhancement Filtering Methods Using MATLAB

Image enhancement is both an art and a science, playing a pivotal role in enhancing the quality of high-resolution images like those captured by digital cameras. Its primary goal is to unveil hidden details within an image and augment the contrast in images with low contrast. This method offers a plethora of options for elevating the visual appeal of images, making it an indispensable tool in numerous applications that face challenges such as noise reduction, degradation, and blurring. In this paper, we implemented frequency domain low pass filters like ideal low pass filter, Butterworth low pass filter and Gaussian low pass filters with execution time using MATLAB. The Butterworth low pass filter given better results than other two with less execution time.

Milk thistle extracts could enhance the UV-protection efficiency and stability of mineral filters in sunscreen formulations

This paper was aimed to determine the total silymarin content, total antioxidant capacity, free radical scavenging activity of methanolic extracts obtained by ultrasonic assisted extraction of defatted milk thistle fruits, as well as to evaluate the sunscreen activity of the cream formulation containing milk thistle extract (MTE) using in vitro SPF method. Antibacterial and antibiofilm effect of extract was also evaluated. Moreover, the probable mode of action for the antioxidant activity of the extract detected via the in vitro assay was explored through molecular docking and molecular dynamics (MD) simulation. The total amount of silymarin in MTE was determined spectrophotometrically as silibinin equivalent. While the total antioxidant capacity of MTE and cream containing MTE was determined by the copper ions (Cu2+) reducing antioxidant capacity (CUPRAC) method, the radical scavenging capacity was determined by the 1,1-diphenyl-2-picryl-hydrazil (DPPH) method. Total tocopherol content was determined spectrophotometrically. In the present study, the amount of silymarin in the MTE was determined as 330.19 ± 1.95 mg silibinin equivalent/g-extract. The CUPRAC and DPPH values of MTE were calculated to be 2.49 ± 0.03, 0.675 ± 0.0006 mmol TE/g-extract, respectively, while the CUPRAC and DPPH values of the cream containing MTE were 0.327 ± 0.003, 0.156 ± 0.0006 mmol TE/g-cream, respectively. The total tocopherol content of the oils of milk thistle fruits was found to be 383.43 mg/kg oil. According to microbial tests results the MIC values of S. aureus and E. coli was detected 0.15625 and 0.3125, respectively. And inhibition rate of extract on biofilm formation on P. aeruginosa PAO1 was found 33 % rate. The molecular docking study demonstrated that the major constituent, silibinin, had a high potential of binding to the human peroxiredoxin 5. On the other hand, the MD simulation of the enzyme-silibinin complex revealed that the compound could be unstable in the binding region of the enzyme. The addition of MTE, which has antioxidant properties, to creams improved its effectiveness on sun protection and contributed to obtaining high SPF values. At the end of day 28 under accelerated test conditions, the combination of ZnO and MTE exhibited greater ability for sun protection compared to the cream containing ZnO as a sun filter agent. Additionally, milk thistle extracts is an ideal filter agent as an ingredient in sunscreens.

Thermoluminescence kinetics in beta-irradiated novel ZnGa2O4:Eu3+ phosphor produced via gel combustion synthesis

Eu3+ doped ZnGa2O4 phosphors with varying dopant concentrations were successfully synthesized using the combustion technique. X-ray diffraction analysis confirmed the consistency of both undoped and Eu3+ doped ZnGa2O4 samples with PDF#38–1240 card structure. The investigation of thermoluminescence (TL) characteristics involved studying TL glow curves in Eu3+ doped ZnGa2O4 samples with different dopant concentrations, employing various optical detection filter combinations. Among these, ZnGa2O4: 2%Eu3+ and the IRSL-TL wide blue band (wbb) proved to be the optimal sample and ideal detection filter pairing for identifying TL features. Following preheating experiments, the TL maximum was observed at around 190 °C, with a heating rate of 2 °Cs−1. The dose-response experiment for ZnGa2O4:2%Eu3+ exhibited satisfactory linearity, with a coefficient of b = 0.988 and an R2 value of 0.989 for doses up to 100 Gy. Moreover, for the dose range of 200–500 Gy, a sublinear relationship was maintained, with a coefficient of b = 0.31 and an R2 value of 0.988. Hoogenstraaten's method, along with the initial rise method and the Tm-Tstop experiment, was also employed in conjunction with a glow curve fitting package. This comprehensive approach facilitated the determination of the number of peaks, trap structure, and kinetic parameters within the thermoluminescence glow curve. Glow curve deconvolution using specialized software revealed the presence of five well-isolated and overlapping TL glow peaks, achieving a figure of merit (FOM) value of 1.39.

Examination of the Efficiency of Fabric Filter Media in Two-Stage Crossflow Pre-Filtration of Turbid Surface Water Using the Davies Flow Equation

Clogging of rapid sand filters during heavy rainfall causes surface water treatment plants to stop their operations until the river water turbidity decreases to a level that the rapid sand filter is capable of filtering. As clogging of rapid sand filters is impediment in surface water treatment, two-stage crossflow pre-filtration with fabric filter media (linen, crepe-backed satin, burlap, and cotton) was considered in a previous study by Davis and Ekwue (2020) as a possible solution. Pre-filtration with linen fabric filter medium was found to be the most efficient at retaining particles. The present paper incorporated properties of various fabrics previously measured and identified by Davis and Ekwue (2020) with the aim of identifying ideal fabric properties that were effective in removing particles from turbid water. Mechanisms of filtration (surface straining, depth filtration and cake filtration) depicted by each selected fabric during two-stage crossflow pre-filtration were identified and compared to the operation of standard filter media (absorbent, adsorbent, biological and woven). The Davies equation was used to calculate the flow of water through single layer and four layers of fabric filter media. Results indicate that no one specific fabric property could be used to proclaim a fabric as the ideal filter media, but rather all properties of the various fabric contribute to their performance during filtration.Linen fabric was once again determined as the fabric type most efficacious at retaining particles during two-stage crossflow pre-filtration of turbid river water and is therefore recommended.

Development of data-driven models for the optimal design of multilayer sand filters for on-site treatment of greywater

Greywater, with limited content of pathogens, makes up more than half of the produced wastewater in urban areas. Given the high cost of wastewater management and treatment, it causes sense to collect greywater separately at the source and employ an on-site treatment system to increase opportunities for on-site water reuse. For this purpose, this paper aims to propose a multilayer granular filter as an inexpensive and simple on-site treatment method for greywater reuse. Furthermore, as determining the optimal structure of multilayer filters is a serious challenge, a simulation-optimization model is developed for determining the best filter configuration. An Artificial Neural Network (ANN) is trained based on experimental results to simulate the filter performance with different combinations of layers and the Genetic Algorithm (GA) is used to find the optimal thickness of different layers based on ANN simulation results. The proposed filter in this paper for greywater treatment consists of silica sand (in three different gradings) and activated carbon (with fixed grading) and treatment measures for evaluation of filter performance are considered as Chemical Oxygen Demand (COD) and Electrical Conductivity (EC). Due to difficulties in collecting, transferring, and storing the real greywater, synthetic greywater was used in this study. 49 experiments with different combinations of filter media thicknesses were performed and the performance of the filter was analyzed. Generally, three-layer filters perform better in COD and EC reduction, however, the average COD and EC elimination equals 36.3% and 15.1%, respectively, which indicates more efficiency of filter in COD reduction in comparison with EC. Based on the optimization-simulation model and experimental results, a filter consisting of 33 cm of fine sand, 20 cm of activated carbon, and 7 cm of medium sand results in the maximum efficiency and can reduce the COD and EC of greywater by 72% and 30%, simultaneously. According to the optimization outputs, the ideal filter can treat greywater up to having EC of 1000 μS/cm and COD of 321 mg/L, which is generally suitable for irrigation purposes.

Jointly Distributed Filtering Based on Generalized Maximum Correntropy Criterion: Memory-Based Event-Triggered Cases

This article addresses jointly distributed entropy filtering issues based on the generalized maximum correntropy criterion (GMCC) for discrete-time stochastic parameter systems with fault and non-Gaussian noise effects. By taking current and historical triggered information, a memory-based event-triggered scheme with a time-varying threshold is put forward to govern the network communication. According to the constructed jointly distributed entropy filter with a two-step form, the upper bounds of the filtering error covariance matrices are derived and an ideal filter gain is obtained to maximize GMCC. Furthermore, an accessible gain is received via fixed-point iterative rules and the corresponding convergence is disclosed in theory. Finally, an application of the proposed distributed filter in ballistic object tracking is provided to show its effectiveness under non-Gaussian environments.

A Novel Synthesis of Quasi-Chebyshev Ultra-Wideband Bandpass Filter Using Nth Order Stub Loaded Coupled-Line Resonator.

This paper presents a novel synthesis of a quasi-Chebyshev Nth order stub-loaded coupled-line ultra-wideband bandpass filter. A unit element of a proposed filter topology consists of two short-circuited stubs loaded at the edges of coupled lines. A distributed equivalent circuit model of a proposed topology is extracted and used to acquire a generalized filtering function. The extracted filtering function is of rational form. The denominator of the filtering function causes a mismatch with Chebyshev type-I polynomials. For conventional narrowband filters, the denominator term can be neglected because of the close vicinity of band-edge frequencies; however, for the ultra-wideband filter response, the factor in the denominator cannot be neglected and hence requires a new mathematical procedure to compensate for the effect of the frequency-dependent term in the denominator. The electrical parameters are calculated using the proposed synthesis and used to design an ideal filter topology on ADS. To validate the proposed design procedure, fabrication is performed on a high-frequency substrate. The proposed filter is miniaturized in size and has good out-of-band performance. The simulated and measured results provide good agreement.