Deepak Bagai

A new algorithm for skew detection and correction

Here we have proposed two algorithms. The first one detects the skewing of words and the second corrects the skewing from handwritten words. Both algorithms make use of the Radon transform based projection profile technique. The method does not require pre-processing and it works equally good even with noise. The method is fast. The algorithms have been tested on words taken from more than 200 writers and the results obtained confirm the overall accuracy of proposed system. No error was detected.

Fusion for registration of medical images - a study

The paper is a study demonstrating the application of discrete multiwavelets in medical image registration. The idea is to improve the image content by fusing images like MRI, CT and SPECT images, so as to provide more information to the doctor. The process of fusion is not new but here the results of study have been compared with the results from FCM algorithm used for similar application. Multiwavelets have been used for better clustering, as their decomposition results were better than Daubechies decomposition. A new feature based fusion algorithm has been used. This method shows results better than other methods for image registration when the images have been taken for the same person at a particular angle. The selective fusion not only gives more information but also helps in disease detection.

Analysis of Bandwidth Utilization for Wireless Mesh Networks

Mobile Ad-hoc networks are characterized as networks without any physical connections. In these networks there is no fixed topology due to the mobility of nodes, interference, multi-path propagation and path loss. One particularly challenging environment for multicast is a mobile ad-hoc network (MANET), where the network topology can change randomly and rapidly, at unpredictable times.In this paper, it is proposed to analyze the possibilities of improving the quality of service in multicast routing by using Priority based Bandwidth Reservation Protocol (PBRP) for wireless mesh networks. The routing Protocol used here is On Demand Multicast Routing Protocol (ODMRP),DVMRP and PIM-DM. By simulation results, it is shown that the proposed protocol achieves high bandwidth utilization and throughput with reduced delay, when used in multicast routing protocols.

Propagation modeling — a CSP approach

Radio wave propagation models are extremely important in radio network planning as well as in interference planning, for the frequency range between 500 MHz and 5 GHz. This is because of the fact that an accurate propagation model enables efficient prediction of the coverage area of a cell and efficient resource reallocation in the form of better coverage prediction at the desired area. A certain model is usually applicable to limited distances and other parameter values. The simplest approach to the prediction of the field strength in urban scenarios is empirical models. The empirical models are very fast but they are not very accurate. Each of these models can also be viewed as a Constraint Satisfaction Problem (CSP).

Performance Analysis of Multicasting Routing Protocols in MANETs

—Multicasting is intended for group-oriented communication services. One particularly challenging environment for multicast is a mobile ad-hoc network (MANET), where the network topology can change randomly and rapidly, at unpredictable times. As a result, several specific multicast routing protocols for MANET have been proposed. Multicast approaches can generally be categorized into two: Proactive and On-demand. The proactive approach pre-computes and maintains routes to all nodes, including nodes to which no packets are being sent. The on-demand approach creates the routes between nodes that are solely determined when they are explicitly needed to route packets. Multicasting protocols can also be categorized based on the structure used to forward multicast packets which are tree and mesh based. The uses of on-demand routing approaches have been shown to have significant benefits in terms of reducing the routing protocol overheads. Therefore, this paper focuses on performance of tree and mesh based multicast routing protocols over MANET. This paper also evaluates well known multicast routing protocols, like on-demand multicast routing protocol (ODMRP), protocol independent protocol-dense mode (PIM-DM) and multicast open shortest path first (MOSPF) under a wide range of network conditions and realistic scenarios. More specifically, the concern is to characterize the merits of tree and mesh-based protocols over various ranges of MANET scenarios based on representative performance metrics. The simulation environment is Qualnet-5.0. As a result this paper investigates the relative strength, weaknesses and applicability of each protocol to diverse situation.

A Comparative Analysis of Signaling Systems and Protocols for ATM Networks

ATM provides elaborate signaling support for dynamic establishment and release of switched virtual circuits. The information necessary for traffic contracting is exchanged between the user and the network through the signaling messages. ATM signaling standards exist for both point-to-point as well as point-to-multipoint signaling model. The tasks and procedures defined for setting-up an ATM connection are often very different concerning the relevant specifications of various working bodies (such as ITU-T or ATM-Forum) or certain vendors, although the basics for maintaining ATM connections are always principally the same. The reason for this situation is that the intentions of working bodies are different and each one of them follows specific strategies for certain scenarios (such as for point-to-point or point-to-multipoint). This comparative analysis of signaling systems and protocols for ATM networks identifies several important characteristics and relevant scenarios of selected approaches.