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Using the notion of intuitionistic fuzzy points, the concept of intuitionistic fuzzy filters and $(\in ,\in \vee q)$-intuitionistic fuzzy filters in pre-ordered residuated systems are introduced, and several related properties are investigated. Characterizations of intuitionistic fuzzy filters and $(\in ,\in \vee q)$-intuitionistic fuzzy filters are studied. By forming sub-structures called intuitionistic level set, intuitionistic $q$-set, intuitionistic $\in \vee q$-set, and $(0,1)$-set, the conditions under which they can be filters will be tracked.

Recently, there has been a surge of interest in gapped q-gram filters for approximate string matching. Important design parameters for filters are for example the value of q, the filter-threshold and in particular the shape (aka seed) of the filter. A good choice of parameters can improve the performance of a q-gram filter by orders of magnitude and optimizing these parameters is a nontrivial combinatorial problem. We describe a new method for analyzing gapped q-gram filters. This method is simple and generic. It applies to a variety of filters, overcomes many restrictions that are present in existing algorithms and can easily be extended to new filter variants. To implement our approach, we use an extended version of BDDs (Binary Decision Diagrams), a data structure that efficiently represents sets of bit-strings. In a second step, we define a new class of multi-shape filters and analyze these filters with the BDD-based approach. Experiments show that multi-shape filters can outperform the best single-shape filters, which are currently in use, in many aspects. The BDD-based algorithm is crucial for the design and analysis of these new and better multi-shape filters. Our results apply to the k-mismatches problem, i.e. approximate string matching with Hamming distance.

One-dimensional cellular automata are known to be able to present complex behaviors. In some cases, their evolution may be understood as movings, collisions, or creations of particles. In the case of the special Wolfram's rule 54, Boccara has previously pointed out basic particles. In this paper, we introduce a group which allows the formal study of interactions between these particles. Coming back to the complexity of rule 54 and using the new algebraic classification of Rapaport, we prove that rule 54 is not simple.

We study the behavior of one-dimensional chaotic signals and filtering using the discrete Haar wavelet and Daubechies wavelets.

Recent development in the applications of high temperature superconductor (HTS) filters is introduced. Breakthrough had been made in ultra selective band-pass filter with extremely small fractional bandwidth for 3G mobile base stations. Satisfactory results were achieved in the space qualification mechanical tests of the HTS filters. Field trail of the meteorological radar showed that with HTS subsystem the sensitivity and anti-interference ability of the radar were greatly improved.

Encoder is the measurement device that plays an important role in the electronic industry. In the process of manufacturing, the current mechanical testing methods are not of very high accuracy or are having problems in data processing algorithms. In this paper, the author represents a method for the testing mechanical work of an encoder product by measuring the torque induced by rotating the encoder. The advantages of this method are the high accuracy, stability and low cost. The accuracy of this method can go upto 95–98%. The measurement system uses LabView software as the data processing application and NI instruments as the data acquisition tools.

A cascaded asymmetric photonic crystal Mach–Zehnder filter structure is proposed to improve the quality factor (Q value) and the sensitivity of the tunable optical filter. The mathematical relationship between the output wavelength of M–Z filter and the voltage applied on the multilayer PZT is established. The simulation results show that the full width at half maximum can be decreased from 17 nm to 9 nm, in addition, the transmission peak wavelength varies by adjusting the applied voltage and the sensitivity can attain to 0.7 nm/V by using the multilayer PZT, which can achieve tunable filtering effectively.

In this paper, using a cross-shaped complementary Indium Tin Oxide (ITO)-based metasurface design, the transmission of THz radiation is shown to be filtered within the 3 dB level from maximum in the frequency range of interest ($\sim$333 GHz). Various metasurface structures primarily composed of cross-shaped openings with a 400 micron unit cell size are patterned on top of 1750 micron thick fused silica substrates. They are patterned using UV lithography methods after the films were grown using DC sputtering. The fabricated structures were characterized using Terahertz Time Domain Spectroscopy (THz-TDS) measurement technique. The measured transmission agrees well with the simulation of the structure for four different samples with different geometries. These results suggest that metasurface and/or metamaterial patterns based on ITO in visibly transparent media can be utilized for filtering of frequencies in the long wavelength spectrum. These types of filters can be very useful in the near future for THz communication and security applications.

A wideband metasurface filter based on complementary split-ring resonators (CSRR) has been prepared. The frequency and transmission bandwidth of the metasurface filters with different split widths are discussed. After analyzing the mechanism of the metasurface, the proposed metasurface filters are fabricated. The electromagnetic properties of the metasurface are measured by a designed test system. The measured results are in good agreement with the simulated ones, which shows that the metasurface filter has a wideband property. As the split width of the CSRR increases, the frequency of the passband shifts to higher frequency regions and the transmission bandwidth decreases.

A spatially and spectrally resolved ultra-narrowband absorber with a dielectric grating and metal substrate has been reported. The absorber shows that the absorption rate is more than 0.99 with the absorption bandwidth less than 1.5 nm at normal incidence for TE polarization (electric field is parallel to grating grooves). The angular width of the absorption is about 0.27${}^{\circ }$. The wavelength-angle sensitivity and absorption-angle sensitivity are 13.4 nm per degree and 296.3% per degree, respectively. The simulation results also show the spatially and spectrally resolved ultra-narrowband absorption is originated from the guide-mode resonance. In addition, the wavelength-angle sensitivity can be improved by enlarging the grating period according to the guide-mode resonance mechanism. The proposed absorber has potential applications in optical filters, angle measurement and thermal emitters.

This paper designs a three-axis closed-loop fluxgate system for geophysical prospecting, which contains excitation, induction, and feedback circuits. By analyzing and comparing the noise levels before and after the system operation, it is concluded that the main factor affecting the fluxgate performance is the excitation circuit noise. By analyzing the principle of fluxgate, the noise on the induction signal and feedback signal can reduce the accuracy of fluxgate and even lead to system instability in serious cases. In this paper, a passive filter circuit is designed to reduce the noise associated with the fundamental frequency from the source to ensure stable operation and improved performance of the system. Simulation and experimental data show that after using the filter circuit, the secondary frequency noise level of the induction signal and the feedback signal noise level are reduced by 10 times, and the trend capturing capability under external magnetic field is greatly improved.

Novel features and weak classifiers are proposed for face detection within the AdaBoost learning framework. Features are histograms computed from a set of spatial templates in filtered images. The filter banks consist of Intensity, Laplacian of Gaussian (Difference of Gaussians), and Gabor filters, aiming to capture spatial and frequency properties of faces at different scales and orientations. Features selected by AdaBoost learning, each of which corresponds to a histogram with a pair of filter and template, can thus be interpreted as boosted marginal distributions of faces. We fit the Gaussian distribution of each histogram feature only for positives (faces) in the sample set as the weak classifier. The results of the experiment demonstrate that classifiers with corresponding features are more powerful in describing the face pattern than haar-like rectangle features introduced by Viola and Jones.

This paper briefly studies the method of collecting audio signals and the method of adding noise to audio signals. It comprehensively applies various basic knowledge of digital signal processing, and then performs spectrum analysis on noise-free frequency signals and spectral analysis of noise-added frequency signals, and filtering processing. Through theoretical derivation, the corresponding conclusions are drawn, and then MATLAB is used as a programming tool to carry out computer implementation to verify the conclusions derived. In the research process, the filter processing was completed by designing the IIR digital filter and the FIR digital filter, and MATLAB was used to draw the graphics and calculate and simulate some data in the whole design.

This article presents a new approach to the partitioning of large dictionaries by virtual views. The basic idea is that additional knowledge sources of text recognition and text analysis are employed for fast dictionary look-up in order to prune search space through static or dynamic views. The heart of the system is a redundant hashing technique which involves a set of hash functions dealing with noisy input efficiently. Currently, the system is composed of two main system components: the dictionary generator and the dictionary controller. While the dictionary generator initially builds the system by using profiles and source dictionaries, the controller allows the flexible integration of different search heuristics. Results prove that our system achieves a significant speed-up of dictionary access time.

In this paper, a universal current-mode second-order active-C filter for simultaneously realizing low-pass, band-pass and high-pass responses is proposed. The presented filter employs only three plus-type second-generation current-controlled conveyors (CCCII+s). This filter needs no critical active and passive component matching conditions and no additional active and passive elements for realizing high output impedance low-pass, band-pass and high-pass characteristics. The angular resonance frequency (ω₀) and quality factor (Q) of the proposed resistorless filter can be tuned electronically. To verify the theoretical analysis and to exhibit the performance of the proposed filter, it is simulated with SPICE program.

A new, self-biasing, differential pair-based and high performance CMOS CCII circuit is proposed which uses no additional biasing voltage or current sources other than the two supply rails. The proposed circuit has high voltage swings on ports X and Y, very low equivalent impedance on port X, high equivalent impedances on ports Y and Z and also wideband voltage and current transfer ratios. The noise analysis of the proposed CCII circuit is studied. Input referred noise voltage at high impedance port Y and input referred noise current at low impedance port X are obtained to form the noise model. Some filter circuits are selected from the literature and their noise comparisons are performed. It is shown that the noise values can differ greatly even though the filter circuits or the passive element values are identical.

In this paper, a new voltage-mode (VM) multifunctional filter comprising two second-generation current conveyors (CCIIs) is proposed. The proposed filter with one input and three outputs is also composed of three resistors and two grounded capacitors. The proposed filter has high input impedance; thus, it can be easily connected with other VM circuits. The proposed filter can simultaneously provide low-pass (LP), band-pass (BP) and high-pass (HP) responses. A number of time domain and frequency domain simulation results are included to confirm the claimed theory.

Operational Transconductance Amplifier (OTA) is an important circuit block used in the design of filter, amplifiers and oscillators for various analog-mixed circuit systems. However, design of a low-noise, high-gain OTA with low-power consumption is a challenging task in CMOS technology owing to high-power requirements of OTA for emulating high gain. This paper represents the design of gate-driven quasi-floating bulk recycling folded cascode (GDQFB RFC) OTA which has been shown to provide low-noise operation, emulates high gain and draws very less power. The design utilizes the gate-driven quasi-floating bulk (GDQFB) technique on a recycling folded cascode structure, which enhances the transconductance of OTA and improves its performance. All the post-layout simulation results have been obtained in 0.18-μm CMOS N-well technology using BSIM3V3 device models. The obtained results indicate very high gain of 100.4 dB, gain-bandwidth of 69 kHz, phase margin of 51.9^∘ with power consumption of 2.31μW from ±0.9V supply voltage. The input referred noise emulated by proposed OTA is 0.684, 0.21 and 0.0592μV/√Hz @ 1 Hz, 10 Hz and 1 kHz, respectively. The input common mode range and output voltage swing are found to be −0.402 to 0.669 V and −0.493 to 0.610 V, respectively. Corner simulations and Monte Carlo analysis have been performed to verify the robustness of the proposed OTA. The proposed OTA can be used in design of filters and amplifiers for bio-instruments, sensor applications, neural recording applications and human implants etc.

The detrended fluctuation analysis (DFA) [Peng et al., 1994] and its extensions (MF-DFA) [Kantelhardt et al., 2002] have been used extensively to determine possible long-range correlations in self-affine signals. While the DFA has been claimed to be a superior technique, recent reports have indicated its susceptibility to trends in the data. In this report, a smoothing filter is proposed to minimize the effect of sinusoidal trends and distortion in the log–log plots obtained by DFA and MF-DFA techniques.

A new viewpoint on the notion of the limit of a function is proposed. We define a series of algebraic limit transitions of a function and prove that every real function has a number of non-trivial algebraic limits.