Mining Data Streams using Option Trees

Many organizations today have more than very large databases. The databases also grow without limit at a rate of several million records per day. Data streams are ubiquitous and have become an important research topic in the last two decades. Mining these continuous data streams brings unique opportunities, but also new challenges. For their predictive nonparametric analysis, Hoeffding-based trees are often a method of choice, which offers a possibility of any-time predictions. Although one of their main problems is the delay in learning progress due to the presence of equally discriminative attributes. Options are a natural way to deal with this problem. In this paper, Option trees which build upon regular trees is presented by adding splitting options in the internal nodes to improve accuracy, stability and reduce ambiguity. Adaptive Hoeffding option tree algorithm is reviewed and results based on accuracy and processing speed of algorithm under various memory limits is presented. The accuracy of Hoeffding Option tree is compared with Hoeffding trees and adaptive Hoeffding  option tree under circumstantial conditions. Keywords: data stream, hoeffding trees, option trees, adaptive hoeffding option trees, large database

An Effective Data Privacy Mechanism through Secure Session Key Exchange Model for MANET

Data privacy in the mobile ad-hoc network is a problem due to wireless medium, frequent node movement and lack of any centralized infrastructure support. In such case, it is very important to build a reliable and secure network and achieve high throughput in MANET. The reliability and security of a network depend on whether the network remains linked to different failures and malicious activities, which is the fundamental issue that needs to be focused when designing a secure routing protocol in MANET. This paper proposes an effective privacy mechanism to handle data security through a novel secure session key exchange model, which provides the node data privacy and network stability for a longer period of time and prevents abnormal behavior changes due to malicious behavior and different type of attacks in the network. The simulation results show improvement in throughput with nominal overhead and end-to-end delay in different malicious conditions against existing protocols

Classification of Solutions of Non-homogeneous Non-linear Second Order Neutral Delay Dynamic Equations with Positive and Negative Coefficients

In this paper we have studied the non-homogeneous non-linear second order neutral delay dynamic equations with positive and negative coefficients of the form classified all solutions of this type equations and obtained conditions for the existence or non-existence of solutions into four classes and these four classes are mutually disjoint. Examples are included to illustrate the validation of the main results

Hybrid Low Complex near Optimal Detector for Spatial Modulation

In our previous work maximum throughput in multi stream MIMO is analyzed by overcoming the inter antenna interference. To mitigate the Inter antenna interference spatial modulation can be used. Spatial Modulation(SM) aided MIMO systems are the emerging MIMO systems which are low complex and energy efficient. These systems additionally use spatial dimensions for transmitting information. In this paper a low complex detector based on matched filter is proposed for spatial modulation to achieve near maximum likelihood performance while avoiding exhaustive ML search since MF based detector exhibits a considerable reduced complexity since activated transmitting antenna and modulated amplitude phase modulation constellation are estimated separately. Simulation results show the performance of the proposed method with optimal ML detector, MRC and conventional matched filter methods

TRUST MANAGEMENT SCHEME FOR AD-HOC NETWORKS USING A SOCIAL NETWORK BASED APPROACH FOR SECURE ROUTING

ABSTRACT A social network is a social structure made up of actors which includes individuals or organizations. These actors are called "nodes", which are tied (connected) by one or more specific types of interdependency, such as friendship, information exchange, kinship, common interest, financial exchange, dislike, sexual relationships, or relationships of beliefs, knowledge or prestige. Social Network analysis is the mapping and measurement of relationships (ties) and flows between the actors (nodes) in terms of network theory. In this paper we propose a Trust Management Scheme for Ad-Hoc Networks using a Social Network Based Approach for secure routing

Homoplastic microinversions and the avian tree of life

Background: Microinversions are cytologically undetectable inversions of DNA sequences that accumulate slowly in genomes. Like many other rare genomic changes (RGCs), microinversions are thought to be virtually homoplasyfree evolutionary characters, suggesting that they may be very useful for difficult phylogenetic problems such as the avian tree of life. However, few detailed surveys of these genomic rearrangements have been conducted, making it difficult to assess this hypothesis or understand the impact of microinversions upon genome evolution. Results: We surveyed non-coding sequence data from a recent avian phylogenetic study and found substantially more microinversions than expected based upon prior information about vertebrate inversion rates, although this is likely due to underestimation of these rates in previous studies. Most microinversions were lineage-specific or united well-accepted groups. However, some homoplastic microinversions were evident among the informative characters. Hemiplasy, which reflects differences between gene trees and the species tree, did not explain the observed homoplasy. Two specific loci were microinversion hotspots, with high numbers of inversions that included both the homoplastic as well as some overlapping microinversions. Neither stem-loop structures nor detectable sequence motifs were associated with microinversions in the hotspots. Conclusions: Microinversions can provide valuable phylogenetic information, although power analysis indicate

Performance Evaluation of 802.11e with typical data rates

The type of the applications for which Internet is being used has changed dramatically over the years. Some of the applications require the network to provide Quality of Service (QOS). IEEE 802.11e is the QOS extension of the Wireless Local Area Network standard IEEE 802.11. This paper does the performance evaluation of 802.11e with voice, video, data and background traffic. The data rates and packet sizes considered are those used in the real environment. The results show that the 802.11e achieves service differentiation. NS2 is used as a network simulator.Keywords -QOS, Normalized throughput, IEEE 802.11e, ns2, evaluationNigerian Journal of Technological Research vol 7(1) 201

TCP over IEEE 802.11

IEEE 802.11 is a widely used wireless LAN standard for medium access control. TCP is a prominent transport protocol originally designed for wired networks. TCP treats packet loss as congestion and reduces the data rate. In wireless networks packets are lost not only due to congestion but also due to various other reasons. Hence there is need for making TCP adaptable to wireless networks. Various parameters of TCP and IEEE 802.11 can be set to appropriate values to achieve optimum performance results. In this paper optimum values for various parameters of IEEE 802.11 are determined. Network simulator NS2 is used for simulation