Electrical and Electronics

A mobile ad hoc network consists of mobile nodes that communicate in an open wireless medium. Adversaries can launch analysis against the routing information embedded in the routing message and data packets to detect the traffic pattern of the communications; thereby they can obtain the sensitive information of the system, like the identity of a critical node. Privacy-preserving routing is crucial for some ad hoc networks that require stronger privacy protection. A number of schemes have been proposed to protect privacy in ad hoc networks. However, none of these schemes offer complete unlinkability or unobservability properties since data packets and control packets are still linkable and distinguishable in these schemes. In this paper, we define stronger privacy requirements regarding privacy-preserving routing in mobile ad hoc networks. Then we propose an unobservable secure routing scheme Secure Un-Obseravable Routing Protocol to offer complete unlinkability and content unobservability for all types of packets. On- Demand secure Routing protocol is efficient as it uses a novel combination of group signature and ID-based encryption for route discovery. Security analysis demonstrates that SRTURP can well protect user privacy against both inside and outside attackers. This Secure Routing Protocol is implemented on ns2, and evaluated its performance by comparing with Ad-hoc On Demand Distance Vector and MASK. The simulation results show that SRTURP not only has satisfactory performance compared to Ad-hoc On Demand Distance Vector, but also achieves stronger privacy protection than existing schemes like MASK.A mobile ad hoc network consists of mobile nodes that communicate in an open wireless medium. Adversaries can launch analysis against the routing information embedded in the routing message and data packets to detect the traffic pattern of the communications; thereby they can obtain the sensitive information of the system, like the identity of a critical node. Privacy-preserving routing is crucial for some ad hoc networks that require stronger privacy protection. A number of schemes have been proposed to protect privacy in ad hoc networks. However, none of these schemes offer complete unlinkability or unobservability properties since data packets and control packets are still linkable and distinguishable in these schemes. In this paper, we define stronger privacy requirements regarding privacy-preserving routing in mobile ad hoc networks. Then we propose an unobservable secure routing scheme Secure Un-Obseravable Routing Protocol to offer complete unlinkability and content unobservability for all types of packets. On- Demand secure Routing protocol is efficient as it uses a novel combination of group signature and ID-based encryption for route discovery. Security analysis demonstrates that SRTURP can well protect user privacy against both inside and outside attackers. This Secure Routing Protocol is implemented on ns2, and evaluated its performance by comparing with Ad-hoc On Demand Distance Vector and MASK. The simulation results show that SRTURP not only has satisfactory performance compared to Ad-hoc On Demand Distance Vector, but also achieves stronger privacy protection than existing schemes like MASK.

Modern landmines are mainly non- metallic or contain small amount of metal, that they cannot be detected using conventional detectors. Ground Penetration Radar (GPR) is capable of detecting shallowly buried non-metallic objects. GPR is the best alternative for detecting non-metallic landmines. But, GPR also performs inadequately due to the presence of clutter which dominates the data and obscures the main information. In this paper symmetrical ?ltering method is going to be applied on measured B-scan data to reduce unsymmetrical clutter. Results of the symmetry ?ltering and symmetry point location algorithm are presented.

Antenna arrays are particularly preferred as they provide flexibility in design, excellent gain and high directivity. They allow optimization via the tapering of amplitude, the special distribution, the phase distribution or their combination providing also the option to generate specific sector and cosec beams for advanced radar applications. The narrow beams obtained from parabolic antennas or from an array of radiators are used to achieve high gain, precise direction finding and high degree of resolution of complex targets. But these narrow beams require multi scans which is highly involved and time consuming. These difficulties can be overcome by providing flat beams which are broad basically. The phase only control allows a fast scanning of the beam without moving the antenna structure. In this paper an attempt is made to design an array of antennas to produce shaped beams like sectors by introducing an optimally designed phase distribution. The results of this paper are extremely useful for designers of antenna arrays for scanning and non-scanning radar and communication applications.

Practical transceivers have hardware impairments, which may affect the data rate of a system. In this paper, two way relaying with hardware losses is considered and is different from previous methods, which considers only ideal hardware case. Here both hops are subjected to independent and non-identical distributed nakagami-m fading variants with Amplify-and-Forward (AF) protocol and Decode-and-forward (DF) protocol. Hardware impairments are calculated at source, relay and destination. The outage probability is calculated with a function effective end-to-end signal-to-noise-and-distortion ratio (SNDR). In a similar way ergodic capacity also achieved. For low SNR values losses will be less but substantial. And for high SNR values losses will increase without bounds. But for SNDR case, increasing SNR makes some constant value of threshold, which is inversely proportional to the SNDR, called SNDR ceiling. Finally, this paper suggests the design guidelines for selecting hardware equipment to overcome hardware impairments with maximum extent.

For some decades, power quality did not cause any problem, because it had no effect on most of the loads connected to the electrical distribution system. Voltage sags is the most common type of power quality disturbance in the distribution. Recently various power electronic devices are proposed for this purpose. Among these devices special attention was given to the family based on the VSC technology for faster response. This project intends to investigate mitigation technique that is suitable for different type of voltage sags source with different type of loads. The mitigation techniques that will be studied are such as Dynamic Voltage Restorer (DVR), Distribution Static Compensator (DSTATCOM). The simulation is done using PSCAD/EMTDC software.

Power electronic devices are non-linear loads that create harmonic distortion and can be susceptible to voltage dips if not adequately protected. The non linear nature of these switching devices causes harmonic current injection into the ac mains; there by polluting the power quality (PQ) at the point of common coupling (PCC).This power quality (PQ) improvement is achieved by using multi-pulse converters in THREE-PHASE ac-dc converters (ADCs).The proposed multi-pulse ac-dc converter is based on autotransformer configurations and passive tuned filters. The proposed ac–dc converter is able to eliminate lower order harmonics in the ac supply current. The resulting supply current is near sinusoidal in shape with low total harmonic distortion and a nearly unity power factor. The proposed multi-pulse ac-dc converter is designed and the simulation model is developed in MATLAB. It improves the power quality at the ac mains and meets IEEE-519 standard requirements at varying loads.

Several approaches have been introduced in literature for active noise control (ANC) systems. Since FxLMS algorithm appears to be the best choice as a controller filter, researchers tend to improve performance of ANC systems by enhancing and modifying this algorithm. In this paper, modification is in done the existing FxLMS algorithm that provides a new structure for improving the tracking performance and convergence rate based on the secondary path modeling technique. The convergence rate is improved by the dynamically varying the step size of the error signal. It is also implemented using FPGA.

An efficient approach for producing electricity from the abundant energy of the sun is discussed. The Nantenna Electromagnetic Collectors (NEC) [1] devices target mid-infrared wavelengths, where conventional photovoltaic (PV) solar cells are inefficient and where there is an abundance of solar energy. The initial concept of designing NEC was based on scaling of radio frequency antenna theory. This NEC is basically a Nano antenna which collects the sun radiation and thermal radiation and converts it into electrical signal. The aim is to realize a low-cost device that will collect and convert this radiation into electricity, which will lead to a wide spectrum, high conversion efficiency, and low-cost solution to complement conventional photovoltaic (PV) solar cells.

Advancement in the field of embedded system and VLSI has induced the researcher in designing low power embedded systems and VLSI circuit design. The embedded systems are mostly batteries operated in nature. The power loss during static, dynamic and switching characteristics are tabulated. The switching nature in cmos constitutes a large value of power loss during the switching condition. Many research papers have been proposed in reducing the switching loss, and low power estimation, this paper clearly demonstrates the comparison of them. The main features of the dominated design techniques and methodologies of transistor level, gate level, RTL level, behavior level and system level are reviewed. The corresponding advantages and drawbacks, as well as comparisons between the techniques and the methodologies are also presented. The low-power design process such as transistor level, gate level, RTL level, behavior level and system-level models are explained.

The range of brightness levels and Histogram shows how individual brightness levels are occupied in any image, for image contrast measurement .Low-level image processing is one of the most important issues of image enhancement. To control and enhance the contrast, Histogram Equalization (HE) is the simple and effective technique, but this approach causes some unnatural look in output image. For best effect the brightness of input image must be retained. Fuzzy techniques can manage the vagueness and ambiguity efficiently. Fuzzy logic is a powerful tool to represent and process human knowledge in form of fuzzy if-then rules. In this work we are using fuzzy membership function in the proposed algorithm. The proposed concept in this paper is named as Brightness Preservation by Fuzzy based Multi-peak Generalized Histogram Equalization (BPFMGHE) and it is simulated by MATLAB; this technique first combined the global histogram equalization of image with local information and then after calculating noise free generalised multi-peak histogram by equalization, the image was again decomposed into several sub-images, and then applied the fuzzy membership function dependent HE process to each of them to preserve image brightness.The distribution of grey level is in complete control with the given method and image improvement is effective. Image is improved and brightness is preserved effectively with the discussed process.