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Frequency diverse array (FDA) radars have the ability to generate a beam pattern that is a function of range angle and time. The wavy beam pattern can be controlled by using a suitable frequency increment applied at the input of the array elements. Instead of using fixed frequency increment for FDA, we propose a cognitive frequency offset calculation method that supports to beam steer the target position...
Ground clutter has significant effect on height of burst (HOB) accuracy of radio proximity fuzes. Different terrains have different back scattering coefficient that vary with grazing angles and hence will result in different radar cross sections. Therefore it is necessary to analyze the effect of different terrains at different grazing angles on the HOB accuracy of radio proximity fuze. In this paper,...
Sauter Mean Diameter of droplets plays a key role in many industrial applications like engines of gas turbine, furnaces, boilers and also in agricultural sprays. Prediction of optimum SMD is vital not only in the design phase of gas turbine combustor but also influences its performance. Due to complex phenomena involved in atomization of pressure swirl atomizers, the physical phenomena of atomization...
Proper orthogonal decomposition based reduced-order models is a significant model reduction technique in computational fluid dynamics, which are used in many industrial and practical applications e.g., flow control, design, and optimization. The reduced-ordered model works well for laminar flows however, lacks accuracy for complex and turbulent flows. In this paper, we use the 1D and 2D Burgers equations...
This study is focused on the mechanism of propagation of tip clearance flow and corner separation of a high speed, low Reynolds number millimeter size centrifugal compressor passage in a situation with high temperature wall. The physical basis of increasing tip clearance vortex and corner separation vortex, on blade suction surface, is explained by the severe effects when heat transfer is considered...
In dynamical systems, regions containing similar dynamics can be identified and their boundaries visualized using Lagrangian Coherent Structures (LCS). In fluid flows, LCS can be approximated as virtual boundaries dictating the structure of flow. Current study makes use of LCS to simulate two cases for fluid flows; flow features around the turbine blade and a ventilation system. Detection of LCS will...
Distributed Denial of Service (DDoS) attacks comprise of sending huge network traffic to a victim system using multiple systems. Detecting such attacks has gained much attention in current literature. Studies have shown that flow-based anomaly detection mechanisms give promising results as compared to typical signature based attack detection mechanisms which have not been able to detect such attacks...
The objective of this study was to determine the rolling moment for hemispherical nose cylinder configuration caused by the two asymmetric strips on the cylinder. The rolling moment for this configuration was initially predicted using Finite volume based CFD code. The study was carried out at different angles of attack and side slip angles to measure the rolling moment coefficient of the Configuration...
The fatigue life of a large-scale 5MW composite wind turbine blade is carried out in accordance with the simplified stress-based fatigue life estimation method recommended by Germanischer-Lloyd regulations. Two kinds of composite layups, ply-level and laminate-level, for the blade are developed and evaluated. The fatigue loads are computed from aero-servo-elastic simulations for the turbine power...
One of the major research directions in robotic vision focuses on calculating the real world size of objects in a scene using stereo imaging. This information can be used while decision making for robots, manipulator localization in the workspace, path planning and collision prevention, augmented reality, object classification in images and other areas that require object sizes as a feature. In this...
Cryptography is the most effective and common technique used to achieve confidentiality, authentication and non-repudiation of data. In cryptography MACs are used between two parties that share a secret to authenticate information exchange between those parties. Galois/Counter Mode (GCM) is an algorithm for authenticated encryption proposed by National Institute of Standards and Technology (NIST)...
An adaptive stepsize kernel least mean square(AKLMS) algorithm is presented in this paper. A mechanism is introduced here to adjust the stepsize parameter in the output of the KLMS algorithm using gradient descent method. The proposed method improves the results by reducing the training time of the algorithm that also helps in converging to global minima instead of local minima. We named the algorithm,...
Cloud-based services are becoming more prevalent for businesses along with home users who are benefiting from this opportunity by automating backups, making files available online, uploading files from any computer, sharing files and photos, and so on. Generally, limited cloud storage space is available free of cost and while extended storage can be purchased at reasonable price. Evidently, this leads...
WSN nodes operate in an unattended environment and thus have irreplaceable batteries. Thus an important concern is the network lifetime; we need to utilize their energy for a longer time otherwise nodes run out of power. For this purpose various protocols have been established and the subject of our matter is the LEACH protocol. The LEACH protocol is self-organizing and is characterized as an adaptive...
Control mode based on rotor acceleration has been used in many advanced aero-engines to improve the performances of transient process. Under this control mode, acceleration and deceleration performances of all same type engines are consistent ignoring the variances of manufacture, materials and performance degradation. In this paper, we proposed a complete design process of N-dot transient controller...
The switched mode dc-dc converters have been extensively analyzed for an appropriate method of modeling and analysis along with selection of a suitable control technique for improved stability. Various approaches are followed to develop and analyze a suitable scheme for the control of dc-dc converters. Stability is the primary goal in the design of any controller, which can be achieved by appropriate...
Considerable challenges arise in hand tracking due to background clutter, inconsistent lighting, scale changes, occlusions and total object disappearance. In order to cope with these difficulties, we present a robust hand tracker based on enhanced particle filters. To overcome the inherent shortcomings of the particle filter approach, we infuse it with the mean shift (CAMSHIFT) method, thereby reducing...
Problem of finding the null-space arises times and often in many important science and engineering applications. A few of them are bioinformatics, gene expression analysis, structural analysis, computation fluid dynamics, electromagnetics, and optimization theory. Many of the existing methods rely heavily on the structure, size, and sparsity of the matrices in question and are therefore, tailored...
Many websites have made use of motions, videos, flash, gif animations and static images to implement Captcha in order to ensure that the entity trying to connect to their website(s) or system is not a Bot, but a human being. A wide variety of Captcha types and solution methods are available and few are described in section II. All of these Captcha systems possess the functionality of distinguishing...
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