A thin, hollow, monocone antenna above a ground plane was constructed and studied. The antenna was used to roughly model the convergent region of a rocket exhaust nozzle. The input impedances and currents on the alumi...
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A thin, hollow, monocone antenna above a ground plane was constructed and studied. The antenna was used to roughly model the convergent region of a rocket exhaust nozzle. The input impedances and currents on the aluminum antenna were measured. The monocone field expansions were found for the exterior and interior regions of the antenna. Mode matching was used to determine the coefficients of expansion with an edge condition applied to the rim of the antenna. After the approximate electric and magnetic fields were found, the associated time-averaged Poynting vector was produced and mapped.
The easy access and wide usage of the Internet make it more convenient for technical research and information exchange. However, malicious codes, such as Code Red, Nimda, SQL Slammer and W32/Blaster, also occur more f...
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The easy access and wide usage of the Internet make it more convenient for technical research and information exchange. However, malicious codes, such as Code Red, Nimda, SQL Slammer and W32/Blaster, also occur more frequently and severely than ever. These self-propagating malicious codes can invade network and paralyze normal network operation. These Internet worms could, in a very short time, cause great damage to network and information infrastructure. Therefore, Internet worms have become vital threats to network and security management. In this paper, we present a proactive responding scheme to deal with Internet worms. Based on this scheme, we designed and implemented a pro-active defending system against Internet worms. This proactive defending system will monitor network traffic, detect hosts with abnormal network behavior and isolate these hosts from the managed network. The results show that it can efficiently mitigate the impact caused by Internet worms and stop the wide-spreading of Internet worms.
This paper proposes a Context Based Emotional controller (CBEC) to Thyrislor controlled Series Capacitor (TCSC), which might have a significant impact on power system dynamics. The role of a CBEC is to control a firin...
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This paper proposes a Context Based Emotional controller (CBEC) to Thyrislor controlled Series Capacitor (TCSC), which might have a significant impact on power system dynamics. The role of a CBEC is to control a firing angle of the TCSC. In this case, the CBEC is used for damping the low frequency oscillations caused by disturbances such 3s a sudden change of small or large loads or an outage in the generators or transmission lines. To evaluate the usefulness of the proposed method, we compare the response of CBEC with fumy PI) controller. The simulation results show that our method has the better control performance than fuzzy PD controller.
This paper considers the stability of the fractional-order linear time-invariant systems with interval type uncertainties in both fractional orders and the relevant coefficients. It is an extension of our previous res...
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This paper considers the stability of the fractional-order linear time-invariant systems with interval type uncertainties in both fractional orders and the relevant coefficients. It is an extension of our previous result on the robust stability analysis of the interval type uncertain fractional order LTI systems with crisply known fractional orders. We have proposed a stability check procedure for uncertain LTI systems with interval fractional orders and interval coefficients. The procedure is demonstrated with some simple examples
Neuroscientists believe that human beings recognize faces not only by utilizing some holistic search among all learned faces, but also through a feature analysis that aimed to specify more important features of each s...
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Neuroscientists believe that human beings recognize faces not only by utilizing some holistic search among all learned faces, but also through a feature analysis that aimed to specify more important features of each specific face. In this paper, we propose a hierarchical classifier that uses both holistic search and per face dominant feature analysis to recognize faces. Reinforcement learning is used to find a set of dominant features for each image in a training dataset. Wavelet transform is employed as a preprocessing tool, which results in higher discrimination among classes. Simulation studies justify the better performance of the proposed method as compared to that of eigenface method.
Images are often contaminated by impulse noise. The major drawback of median filtering and its variants - that are widely used for removing impulsive noise - is the blurring effect for large window sizes and low noise...
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Images are often contaminated by impulse noise. The major drawback of median filtering and its variants - that are widely used for removing impulsive noise - is the blurring effect for large window sizes and low noise suppression for small window sizes. In this paper, a fuzzy-competitive algorithm for removing impulse noise in images is proposed. The proposed algorithm utilized fuzzy inference systems for impulse detection. The detected impulses are then removed using long-range correlation information in a competitive scheme. The experimental results show that the performance of our method in removing impulsive noises is better than that of most other state-of-the-art methods
This paper proposes a new method of face representation which is used for face recognition by SVM. For face representation we have used a two-step method, first two-dimensional discrete wavelet transform (DWT) is used...
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This paper proposes a new method of face representation which is used for face recognition by SVM. For face representation we have used a two-step method, first two-dimensional discrete wavelet transform (DWT) is used to transform the faces to a more discriminated space and then principal component analysis (PCA) is applied. The proposed method produced a significant improvement which includes a substantial reduction in error rate and in time of processing during the obtaining PCA orthonormal basis.
This paper deals with modeling and analysis for the landing motion of a human-body model. First, the dynamic model of a floating human body and the impact model are derived and the external impulse exerted on the grou...
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This paper deals with modeling and analysis for the landing motion of a human-body model. First, the dynamic model of a floating human body and the impact model are derived and the external impulse exerted on the ground as well as the internal impulse experienced at the joints of the human body model are investigated. Second, a motion planning algorithm exploiting the kinematic redundancy is suggested to ensure stability in terms of ZMP stability condition during a series of landing phases. Four phases of landing motion are investigated. In simulation, the external and internal impulses experienced at the human joints and the ZMP history resulting from the motion planning are analyzed for two different configurations. A desired landing posture is suggested by comparison of the simulation results.
This paper focuses on genetic optimization and filtering efficiency ofa recently developed class ofWeighted Vector Directional Filters (WVDFs), which minimize the aggregated weighted angular distances between the samp...
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In this paper, we provide a new noise reduction method for the enhancement of the images of gene chips. We demonstrate that the new technique is capable of reducing outliers present in microarray images while preservi...
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