Showing 4 results for Pattern Recognition
A. Ebrahimzadeh, S. A. Seyedin,
Volume 1, Issue 4 (10-2005)
Abstract
Automatic signal type identification (ASTI) is an important topic for both the
civilian and military domains. Most of the proposed identifiers can only recognize a few
types of digital signal and usually need high levels of SNRs. This paper presents a new high
efficient technique that includes a variety of digital signal types. In this technique, a
combination of higher order moments and higher order cumulants (up to eighth) are
proposed as the effective features. A hierarchical support vector machine based structure is
proposed as the classifier. In order to improve the performance of identifier, a genetic
algorithm is used for parameters selection of the classifier. Simulation results show that the
proposed technique is able to identify the different types of digital signal (e.g. QAM128,
ASK8, and V29) with high accuracy even at low SNRs.
E. Farshidi,
Volume 5, Issue 1 (3-2009)
Abstract
In this paper a new synthesis for circuit design of Euclidean distance calculation
is presented. The circuit is implemented based on a simple two-quadrant squarer/divider
block. The circuit that employs floating gate MOS (FG-MOS) transistors operating in weak
inversion region, features low circuit complexity, low power (<20uW), low supply voltage
(0.5V), two quadrant input current, wide dynamic range and immunity from body effect. In
addition, this circuit is designed in modular methodology, leading to a very regular
structure. The circuit was successfully applied to the recognition of some simple patterns.
Simulation results of the circuit by HSPICE show high performance in the separation and
confirm the validity of the proposed technique.
M. R. Aghamohammadi, S. Hashemi, M. S. Ghazizadeh,
Volume 7, Issue 2 (6-2011)
Abstract
Abstract: Voltage instability is a major threat for security of power systems. Preserving voltage security margin at a certain limit is a vital requirement for today’s power systems. Assessment of voltage security margin is a challenging task demanding sophisticated indices. In this paper, for the purpose of on line voltage security assessment a new index based on the correlation characteristic of network voltage profile is proposed. Voltage profile comprising all bus voltages contains the effect of network structure, load-generation patterns and reactive power compensation on the system behaviour and voltage security margin. Therefore, the proposed index is capable to clearly reveal the effect of system characteristics and events on the voltage security margin. The most attractive feature for this index is its fast and easy calculation from synchronously measured voltage profile without any need to system modelling and simulation and without any dependency on network size. At any instant of system operation by merely measuring network voltage profile and no further simulation calculation this index could be evaluated with respect to a specific reference profile. The results show that the behaviour of this index with respect to the change in system security is independent of the selected reference profile. The simplicity and easy calculation make this index very suitable for on line application. The proposed approach has been demonstrated on IEEE 39 bus test system with promising results showing its effectiveness and applicability.
S. Tannaz, T. Sedghi,
Volume 14, Issue 2 (6-2018)
Abstract
In this article, a fabulous method for database retrieval is proposed. The multi-resolution modified wavelet transform for each of image is computed and the standard deviation and average are utilized as the textural features. Then, the proposed modified bit-based color histogram and edge detectors were utilized to define the high level features. A feedback-based dynamic weighting of shape, color and textural features composition produce a resistant feature vectors for image retrieval and recall. A comprehensive and unified matching scheme based on matrix error rate technique was accomplished for similarity of image and retrieval procedure. The feature vectors size in our algorithm is the least one evaluated to the different techniques. Furthermore, the calculation time of previously published techniques is much more than the presented algorithm which is a benefit in proposed retrieval method. The experimental results illustrates that novel algorithm obtains more precious in retrieval and the efficiency in evaluating with the other techniques and algorithms at Corel color image database.
