Vignan University

About: Vignan University is a education organization based out in Guntur, Andhra Pradesh, India. It is known for research contribution in the topics: Computer science & Control theory. The organization has 1138 authors who have published 1381 publications receiving 7798 citations.

Face Recognition with Modular Two Dimensional PCA under Uncontrolled Illumination Variations

Abstract: Person authenticaton using faces became one of the most popular security approaches for the last three decades. From the literature it is found that perofrmance of most of the methods used in recognition was limited due to uncontrolled conditions like illumination and pose variations. In this work, to address the limitations of uncontrolled environment, Modular two-dimensional Principle Component Analysis (M2D-PCA) is proposed. In this approach, the input image is partitioned into four equal segments and then Histogram Equalization is applied to reduce illumination impact caused due to varying lightening conditions. Then M2D-PCA algorithm is applied parallel on each segment and then all features extracted from the segments are fused with wieghted summation. Experiments are carried out on bench mark datasets like extended Yale database B, ORL and AR database. Results of the proposed approach produced good recognition rate with low computational time against various illumination environments.

Priority Based Centralized Scheduling for Time Slotted Channel Hopping Based Multihop IEEE 802.15.4 Networks

Abstract: To meet the growing demands of low power and determinism in Industrial Wireless applications, IEEE defined IEEE 802.15.4e amendment that includes many channel access methods. Time Slotted Channel Hopping protocol is one of the most popular MAC protocols under IEEE 802.15.4e. However, scheduling of time slots for time slotted channel hopping, was not part of the protocol and so different scheduling algorithms were proposed by researchers. A new time slotted channel hopping scheduling mechanism that considers priorities to meet the time critical industrial applications is proposed in this work. Latency improvements of about 40 percentage are obtained here, for slot allocations to higher priority devices, when compared with the conventional queuing methods.

ZC-CDTA Based Integrator Circuit Using Single Passive Component

Abstract: An integrator with a single passive component based on Z-copy current differencing transconductance amplifier (ZC-CDTA) is introduced in this paper. The major advantage professed in the circuit is that it uses a single ZC-CDTA and one capacitor. The proposed integrator circuit was operated under ±0.9 V supply voltage with bias current of 100 µA by means of Cadence tool with model constraints of gpdk 180 nm in CMOS technology. Monte Carlo results for transient response and noise analysis results are also depicted in the results section of this paper. The total power dissipation of this circuit is 1.2546 mW. The proposed integrator circuit is useful for instrumentation and measurement applications.

Design of Optimal State Observer-Based Controller for 4-DOF Planar Manipulator Using PSO

Abstract: The present paper aims at developing state observer-based controller for a 4-DOF planar serial manipulator. The kinematics of the manipulator has been achieved through D-H convention, and dynamics of the same has been derived after utilizing Lagrange–Euler formulation. The nonlinear dynamic equations have been linearized and expressed in state-space representation. Based on the arbitrarily chosen pole values, pole placement has been done and then observer is designed to evaluate the state variables. Further, PSO algorithm is also used to optimize the pole values and to minimize steady-state error. Once the optimal controller is designed, its performances have been tested in simulations.

Comparative Study of Automatic Urban Building Extraction Methods from Remote Sensing Data

Abstract: Building foot prints and building count information in urban areas are very much essential for planning and monitoring developmental activities, efficient natural resource utilization, and provision of civic facilities by governments. Remote sensing data such as satellite/aerial imagery in association with digital elevation model is widely used for automatic extraction of building information. Many researchers have developed different methods for maximizing the detection percentage with minimum errors. A comparative study of different methods available in the literature is presented in this paper by analyzing the primary data sets, derived data sets, and their usage in the automated and semiautomated extraction methods. It is found that the success of the method for automatic building detection in urban areas primarily depends on using combination of high-resolution image data with digital elevation model.