Showing papers by "Parma Nand published in 2011"

Probability Based Improved Broadcasting for AODV Routing Protocol

Abstract: Broadcasting is an inevitable operation of route discovery in Mobile Adhoc Network (MANET). Though the broadcast by flooding is simple but inefficient and results in redundant message relays. This in turn over use limited network resources like channel bandwidth and node energy. The alleviated broadcasting with energy saving technique is necessary for the efficient route discovery and to improve network lifetime. In this paper Probability based Broadcasting technique for routing protocol is proposed to trim down flooding problem. It uses node's current remaining energy strength and threshold random delay to generate rebroadcast probability dynamically for the efficient broadcasting in route discovery. This technique is analyzed over reactive Adhoc On-Demand Distance Vector (AODV) protocol. The route request (RREQ) packet of AODV is modified to gather energy information of nodes. The performance modified protocol is analyzed over broadcast packets sent and End-to-End Delay using ns2 simulator. Simulation results are observed to reduce redundant transmission by 19 to 28 percent and hence improve network performance.

Cardiac surgery in the Pacific Islands.

Abstract: Background: Rheumatic heart disease constitutes a significant disease burden in under-resourced communities. Recognition of the devastating impact of rheumatic heart disease has resulted in volunteer cardiac teams from Australasia providing surgical services to regions of need. The primary objective of this study was to compare New Zealand hospitals' volunteer cardiac surgical operative results in Samoa and Fiji with the accepted surgical mortality and morbidity rates for Australasia. Methods: A retrospective review from seven volunteer cardiac surgical trips to Samoa and Fiji from 2003 to 2009 was conducted. Patient data were retrospectively and prospectively collected. Preoperative morbidity and mortality risk were calculated using the European System for Cardiac Operative Risk Evaluation (euroSCORE). Audit data were collated in line with the Australasian Society of Cardiac and Thoracic Surgeons guidelines. Results: One hundred and three operations were performed over 6 years. EuroSCORE predicted an operative mortality of 3.32%. In-hospital mortality was 0.97% and post-discharge mortality was 2.91%, resulting in a 30-day mortality of 3.88%. Conclusion: This study demonstrated that performing cardiac surgery in Fiji and Samoa is viable and safe. However, the mortality was slightly higher than predicted by euroSCORE. Difficulties exist in predicting mortality rates in patients with rheumatic heart disease from Pacific Island nations as known risk scoring models fail to be disease, ethnically or culturally inclusive. Audit processes and risk model development and assessment are an essential part of this complex surgical charity work and will result in improved patient selection and outcomes.

Performance analysis of FSR and ZRP routing protocols for MANET

Abstract: An adhoc wireless network is a self-organizing and self-configuring network with the capability of rapid deployment in response to application needs. Each host is equipped with a CSMA/CA (carrier sense multiple access with collision avoidance) transceiver. All the nodes are free to move independently and randomly without any problem. This creates the scenario of multihop, where the packets originated from the source host are relayed by several intermediate hosts before reaching the destination. Routing is the process of finding a path from a source to destination among randomly distributed routers. In this paper hybrid routing protocol called Zone Routing Protocol (ZRP) and Fisheye State Routing Protocol (FSR) are examined. The performance analysis is done using performance metrics throughput, end-to-end delay packet delivery ratio is presented using network simulator Qualnet 5.0.2. The characteristic summery is also presented.

Comparative Analysis of Broadcasting Techniques for Routing Protocols

Abstract: The adhoc network comprises of nodes with a wireless radio interface is multihop network environment in which messages are transmitted from one to another node via intermediate nodes within the range To find an effective and an efficient routing protocol, which is used to transmit information from source to destination across whole network topology, is a major issue in networking research The broadcasting is used to diffuse information among all the neighbors and thus route establishment This approach makes it challenging to control redundant rebroadcasts, channel contention problem, bandwidth congestion and packet collision problem The optimization of communication with mobile routers in dynamic nature of topology is another challenge This paper presents classification of routing protocols with different broadcasting schemes These schemes are summarized and presented in a table

A relational framework for interpreting anaphora

Abstract: In this paper we present a novel way to resolve indirect or bridging anaphora which gives us a richer interpretation then the current frameworks. The new framework uses the core set of relations that have been used to describe compound noun generation. We firstly argue that the linguistic processes of compound noun generation and the use of NP anaphora are based on a common relational framework. In order to validate this theory we used human annotators to interpret indirect anaphora from naturally occurring discourses. The annotators were asked to classify the relation between an anaphor and the antecedent into relation types that have been previously used to describe the relation between the modifier and the head noun of a compound noun. We obtained very encouraging results with a Fleiss’s κ value of 0.66 for inter-annotation agreement. This compares well with other similar annotation experiments for relation interpretation in compound nouns. The annotation results strongly indicate that anaphora and noun compounds are based on very similar relational framework, hence should treated the same.