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The stability of fixed-speed induction generator (FSIG)-based wind turbines can be improved by a StatCom, which is well known and documented in the literature for balanced grid voltage dips. Under unbalanced grid voltage dips, the negative sequence voltage causes heavy generator torque oscillations that reduce the lifetime of the drive train. In this paper, investigations on an FSIG-based wind farm in combination with a StatCom under unbalanced grid voltage fault are carried out by means of theory, simulations, and measurements. A StatCom control structure with the capability to coordinate the control between the positive and the negative sequence of the grid voltage is proposed. The results clarify the effect of the positive- and the negative-sequence voltage compensation by a StatCom on the operation of the FSIG-based wind farm. With first priority, the StatCom ensures the maximum fault-ride-through enhancement of the wind farm by compensating the positive-sequence voltage. The remaining StatCom current capability of the StatCom is controlled to compensate the negative-sequence voltage, in order to reduce the torque oscillations.

The increase in the number of security breaches has made information security risk management an essential security activity for all type of organizations. Risk Management involves assessment involves identification of assets, threats and vulnerabilities. Attacks by outsiders continue to cause the most security breaches to all organizations. Existing approaches like attack graph based risk assessment have scalability issues and focus on only single step attacks. It is very difficult to predict multistep attacks that exploit a chain of vulnerabilities. The multistep attacks are based on the causality of relation where every cause has an effect. Causality refers to a cause i.e. one event and consequences i.e. another event that has occurred because of the cause. The proposed system aims to make use of fuzzy cognitive maps to model the causally dependent events. Fuzzy cognitive map is a concrete representation of knowledge that can handle incomplete or conflicting information. This is very important in risk assessment because important information may be unreliable as they may be a result of unreliable measurement techniques. The proposed system will aid in proactive information security risk assessment.

Recently, Synthetic aperture radar (SAR) systems have been employed for several remote sensing applications such as environmental monitoring, surveillance target identification, and navigation. The speckle noise inherent in SAR images reduces the potential of SAR images to be utilized as effective data in remote sensing applications. Therefore, removal of speckle noise is one of the more important tasks in SAR imaging. Multiresolution analysis is deeply related to various application of image processing field. Such approach like Wavelet transform, undecimated wavelet transform have great impact on denoisng speckle. In this work a multiscale directional curvelet transform is applied to various circularly shifted noisy images to remove speckle noise. The assessment parameters PSNR, NSD, ENL show good results for the proposed approach.

Wireless Mesh network plays a significant role in enhancement of various techniques in wireless communication. The primary goal of wireless mesh networking is to achieve high system throughput. As the topology of the network is unpredictable in a wireless medium due to its mobile nature and hence the routing with high throughput becomes more difficult. Interference is the major cause for performance degradation of any wireless network. In this paper, we provide an comparative study based on the unique features of different interference aware routing metrics and a survey about how interference level is estimated using those metrics.

Removing noise from the original signal is still a challenging problem for all types of image processing applications. Speckle noise is often an undesirable effect in SAR image processing. There is a contradiction between denoising effect and detail-preserving ability. The primary goal of speckle reduction is to remove the speckle without losing much detail contained in an image. This paper presents a denoising scheme for multiplicative speckle noise using multi spinning concept. The proposed approach provides good visual quality.