Paramote Wardkein

Human Identification System Based ECG Signal

A new human identification system based electrocardiogram (ECG) signal is introduced in this work. The human heart is considered to be a unique system of each person. ECG signal therefore represents as an impulse response of the system. The frequency response of the system (Fourier transform of the ECG signal) is employed to be a tool for feature extraction. In addition, the ECG signals employed in this paper, which may be derived from different heart rates from different subjects at the recording time, are normalized to a standard heart rate. Furthermore, not only the whole sequence of 1 period EC signal, containing P, QRS, and T waves, is processed but also its three subsequences, each respectively representing P, QRS, and T waves, is examined. The results of using neural network have demonstrated that subsequences technique is superior to whole period of ECG signal method.

Reliability optimization of topology communication network design using an improved ant colony optimization

Network design problem is a well-known NP-hard problem which involves the selection of a subset of possible links or a network topology in order to minimize the network cost subjected to the reliability constraint. To overcome the problem, this paper proposes a new efficiency algorithm based on the conventional ant colony optimization (ACO) to solve the communication network design when considering both economics and reliability. The proposed method is called improved ant colony optimizations (IACO) which introduces two addition techniques in order to improve the search process, i.e. neighborhood search and re-initialization process. To show its efficiency, IACO is applied to test with three different topology network systems and its results are compared with those obtained results from the conventional approaches, i.e. genetic algorithm (GA), tabu search algorithm (TSA) and ACO. Simulation results, obtained these test problems with various constraints, shown that the proposed approach is superior to the conventional algorithms both solution quality and computational time.

A simple pulse width modulator using current conveyor

A simple pulse width modulator (PWM) is proposed. The circuit principle is based on a relaxation oscillator with a second generation current conveyor (CCII). The proposed scheme is simpler than the existing PWM methods and the duty factor linearly depends on the modulating signal. Another advantage is that the circuit is suitable for IC implementation. The simulation and experimental results are given. They show good agreement with the theoretical analysis.

Adaptive IIR notch filters based on new error criteria

Modified indirect and direct plain gradient (MIPG and MDPG) algorithms using new error criteria for second-order adaptive IIR (infinite-impulse response) notch filters (ANFs) with constrained poles and zeros are proposed in this paper. The proposed techniques are based on modifying error functions of the standard indirect and direct ANFs. In this work, the proposed error criteria are modified as the mean value of the product of the two signals which are, respectively, produced by the FIR (finite-impulse response) and IIR sections of the ANFs. Due to a non-zero slope straight line-like characteristic of the new cost functions, the gradient based adaptive algorithm rapidly converges to an optimum solution resulting in faster convergence speed than that of the conventional method. The closed form expressions for steady-state estimation bias and mean square error (MSE) of the proposed algorithms are also carried out. In addition, extensive simulations of the proposed algorithms compared to other methods are provided to support the theoretical analyses. Although, there are some limitations in the proposed algorithms, however, the demonstrated results obtained from tested algorithms at the same condition confirm that the proposed MIPG and MDPG algorithms are superior to others in convergent speed.

Direct frequency estimation based adaptive algorithm for a second-order adaptive FIR notch filter

This work deals with the problem of the frequency estimation of a sinusoidal signal corrupted by broad-band noise. The direct frequency estimation based adaptive algorithm for a second-order adaptive finite impulse response (FIR) notch filter (AFNF) is thus proposed. The proposed algorithm employs the bias removal technique to remove the bias existing in the estimated parameter. The performances including the rate of convergence and the mean square error (MSE) can be easily controlled by using only one parameter, i.e., step size parameter. Moreover, the proposed filter is simple to implement and suitable for real-time applications. In addition, the difference equations for the convergence in the mean and mean square, and the closed form expressions for the steady-state estimation bias and MSE are also carried out. Finally, the simulation results are provided to confirm the theoretical analysis.

Indirect frequency estimation based on second-order adaptive FIR notch filter

This paper deals with estimating the frequency of sinusoidal signal buried in broad band noise. The simple unbiased indirect frequency estimation (IFE) algorithm is proposed for a second-order adaptive finite impulse response (FIR) notch filter with constrained zeros. The technique of estimating input noise variance is employed to remove the bias existing in the estimated filter parameter. Also, the difference equation for the convergence of the expectation of the estimated parameter and the closed-form of steady state estimation mean square error (MSE) are derived. In addition, extensive simulations are conducted to corroborate the efficiency of the proposed estimator with the theoretical analysis.

Unbiased plain gradient algorithm for a second-order adaptive IIR notch filter with constrained poles and zeros

This article proposes an unbiased plain gradient algorithm for a second-order adaptive IIR notch filter with constrained poles and zeros. The proposed algorithm employs removing a dominant parameter that produces inherent bias. By using this technique, the performances are improved with slight expense in computational complexity. In this paper, theoretical analysis for deriving the estimations of bias and mean square error (MSE) at steady state are presented in closed form. Moreover, the stability bound of the algorithm is also derived. To confirm the analytical results, the computer simulations are provided to corroborate the effectiveness of the proposed algorithm. Furthermore, the performances of the algorithm are also compared with the plain gradient (PG) and modified plain gradient (MPG) algorithms.

Fast communication: Adaptive IIR notch filter using a modified sign algorithm

Modified sign algorithm (MSA) for a second-order constrained adaptive IIR notch filter (ANF) is proposed and analyzed in this paper. Difference equations for the convergence in the mean and of the mean square, and steady-state estimation bias and MSE are derived in closed form. Moreover, a coarse stability for the MSA is carried out. Computer simulations are conducted to corroborate the theoretical analysis.

An enhanced adaptive algorithm for PLI cancellation in ECG signals

This paper presents a technique for determining amplitude and phase of the power line interference (PLI), which is in sinusoidal waveform, by using two consecutive samples under identified sampling rate. The amplitude and phase information will then be employed to initialize parameters of the adaptive noise canceling algorithm whose the interfering noise is modeled as orthogonal sinusoidal functions. Based on computer simulation, the performance of the adaptive algorithm is improved over the conventional algorithm. In addition, the results in various cases of the PLI show that the proposed technique is superior to the results of the ASIC algorithm.

A Novel Monostable Multivibrator Circuit

This article represents a novel monostable multivibrator circuit in which width and height of the pulse output can be independent electronically adjusted. In addition, the pulse width of output is not restricted to be wider or narrower than that of input pulse as conventionally employed. Namely, there is no restriction on the width of input and output pulse, the circuits implementation is thus more convenient. The proposed circuit is composed of three OTAs, two resistors and one capacitor, basically constructed a simple pulse generator (Schmitt-trigger circuit). Therewith the compactness of the circuit, it is thus suitable to be fabricated for integrated circuit. The results of circuit simulation is accordance well with theoretical analysis.