JOURNAL OF IRANIAN ASSOCIATION OF ELECTRICAL AND ELECTRONICS ENGINEERS
Year:2010 | Volume:6 | Issue:2|Papers Count:7

A new automatic target recognition algorithm to recognize and distinguish three classes of targets: personnel, wheeled vehicles and animals, is proposed using a low-resolution ground surveillance pulse Doppler radar. The Chirplet transformation, a time frequency signal processing technique, is implemented in this paper. The parameterized RADAR signal is then analyzed by the Zernike Moments (ZM) in order to feature extraction and they trained to the Nearest Neighbor classifier. The current work provides a new approach for multi-resolution analysis and classification of non stationary signals with the objective of revealing important features in noisy and cluttered environment. The algorithm is trained and tested on real RADAR signatures of multiple examples of moving targets from each class. Results show that the classifier is invariant to target aspect angle and speed.

In a dense modern electronic warfare environment, there are a lot of radar signals. Pulse repetition intervals of signals received from radars can have various modulations and levels. It is very important to recognize these modulations and to determine their levels in electronic warfare support systems. In this paper, a method of estimating PRI levels is proposed. The extensions of the biased autocorrelation functions of the PRI sequences are derived and a new method of recognizing PRI modulation type and its levels is proposed which is based on the properties of the biased autocorrelation function of the PRI sequences and their hierarchical clustering. The performance of the proposed method has also been evaluated in a simulation scenario.

This paper reports a four-pole microstrip high-temperature superconducting (HTS) band-pass filter with a quasi-elliptic function response. A microstrip filter configuration that allows a pair of transmission zeros to be placed at the band edges is described. The filter was fabricated using singlesided YB2Cu3O7 superconducting thin film deposited on a LaAl2O3 single crystal substrate of size 1mm´10mm´10mm by pulsed laser deposition. Very good experimental results were obtained when the filter cooled using liquid nitrogen. The minimum pass-band loss was measured to be approximately 0.5 dB. The pass-band width at points 1 dB down from the minimum loss point was 110 MHz for a center frequency of 3.25 GHz.

Stereophonic acoustic echo cancellation is one of the expanding areas in the field of the speech / multimedia communication systems. In a conventional stereophonic acoustic echo canceller, working in a stereo communication system, the existence of the strong cross-correlation between the input signals to the two channels has the problem of the low convergence speed of the weights of the adaptive filters. In this paper, an algorithm is proposed for reducing the cross correlation of the input signals to adaptive filters that utilizes a special technique for clipping the input signals. The proposed algorithm has the flexibility in the determination of the desirable clipping level with respect to the position of the human-speaker relative to the position of microphones in the transmission section. The simulation results show an improvement in the convergence behavior of the adaptive filters utilizing the proposed scheme.

In MTSC, correlated sources are separately encoded but jointly decoded. With appropriate modeling of all kinds of correlation among three non binary correlated sources, in this paper we propose a method for performing IMTSC among three sources. Due to the possibility of providing an approach for practical code design for more than two correlated sources in IMTSC / CEO setup, the multicast system based on multiterminal source coding is applied to the cases with three servers. At severs IMTSC is implemented via the framework of Slepian - Wolf coded quantization. Experimental results with data, image and video signals show the superiority of our proposed method over the conventional solutions and over multimedia multicast based on multiterminal source coding with two servers. In addition, the advantages of parallel downloading from multiple servers such as robustness to a server failure and security are improved with increasing the number of servers.

An important factor to be considered in electric power system expansion planning is the security of service that the system is able to provide. In restructured power systems, variables such as agents’ profit or Locational Marginal Price (LMP) variances are considered in transmission expansion planning. To have a secure network this plan would be refined for simulated contingencies. This paper proposes a new method for transmission expansion planning in which the grid owner is responsible for expansion while benefiting a fair benefit percentage. The defined objective function of transmission expansion tries to maximize Global Welfare (GW) and reduce the construction cost as well as the cost of security enhancement. For different scenarios of expansion; at first, the cost of security enhancement is calculated and then it is considered in the objective function of expansion. None of the existing methods have considered the optimum security enhancement cost into the objective function along with the other factors of transmission expansion planning under market environment. To implement the proposed method on large scale networks, the ordinal optimization is used and simulation results are performed for the modified “Garver 6-bus test system for expansion” and “IEEE 24-bus reliability test system”.

Load frequency control includes the operating system and functions that provide real time balance of load and generation. On the other hand, depending on technical capabilities and operational constraints, generating units may be classified for participating in frequency control.Simultaneous scheduling of generation together with primary reserve, in market based power system, has been investigated during the past decade. However, in most approaches, real technical capabilities of modern generating units (such as the capability of selecting governor operation modes and selecting the ramp rate) together with operational constraints of generating units have not been considered. In this paper we propose a new approach for simultaneous scheduling of generation and primary reserve considering real technical capabilities and operational constraints of the units. The optimal scheduling is obtained using a heuristic iterative method supported by genetic algorithm. The simulations confirm that our formulation results in a more appropriate solution as compared with previous method.