Amount Of Bytes Research Articles

Effects of Wormhole Attack on Routing Topology

The article is devoted to investigating the effects of wormhole attack on routing topology in Wireless Sensor Networks (WSNs). Currently, WSNs are increasingly vulnerable to numerous security attacks. One of the major attacks affecting WSNs involves a wormhole attack where attackers receive packets at a single end in the network and tunnel the packets to other points in the network and are subsequently replayed in the network. The wormhole attacks can affect the routing topology by redirecting traffic. Because of the nature of WNSs, attackers can develop a wormhole for packets not destined for them due to overhearing them within the wireless network and tunneling them to colluding attackers on the opposite side of the wormhole. Mainly, wormhole attacks are hazardous to ad-hoc network routing protocols. Therefore, it is evident that routing topology suffers from various vulnerabilities and needs robust security measures. This research investigates the effects of wormhole attacks on routing topology, and a simulation is presented to depict wormhole attack effects. In addition, an analysis of whormhole simulation of packet transmission with and without attacker node using Network Simulator NS-2 environment has been carried out. A simulation conducted using NS2 determined the performance of two reactive routing protocols (AODV and DSR) using their throughput, the first and the last packet received, and the total amount of bytes received in two conditions (with and without wormhole). Findings obtained demonstrate that the performance of DSR was better compared to that of AODV. The introduction of wormhole attacks in both routing protocols significantly affected the performance.

Performance Evaluation and Optimization of Multi-dimensional Indexes in Hive

Apache Hive has been widely used for big data processing over large scale clusters by many companies. It provides a declarative query language called HiveQL. The efficiency of filtering out query-irrelevant data from HDFS closely affects the performance of query processing. This is especially true for multi-dimensional, high-selective, and few columns involving queries, which provides sufficient information to reduce the amount of bytes read. Indexing (Compact Index, Aggregate Index, Bitmap Index, DGFIndex, and the index in ORC file) and columnar storage (RCFile, ORC file, and Parquet) are powerful techniques to achieve this. However, it is not trivial to choosing a suitable index and columnar storage based on data and query features. In this paper, we compare the data filtering performance of the above indexes with different columnar storage formats by conducting comprehensive experiments using uniform and skew TPC-H data sets and various multi-dimensional queries, and suggest the best practices of improving multi-dimensional queries in Hive under different conditions.

Analysis of Map Reduce Performance using Prefetching Mechanism

In this massive technological atmosphere the number of information generated is increasing at an awfully high rate. Distributed storage system will be used for storing this immense quantity of information. Massive information will be handled by victimization hadoop and map reduces. The multiple node clusters will discover victimization the hadoop framework. Hadoop comes with default distributed file system that is hadoop distributed file system. The mapped is enforced by map technique and that we can see the performance of map reduce task on the bases of bytes written. The amount of bytes written by map task doesn't increase with the amount of files increasing. The explanation is that once the reduce function perform reduces the map output it simply combines the output of the map function. Thus so as to enhance the performance of map reduce task we are going to setup the cluster of nodes in heterogeneous atmosphere and analyze the behavior of map reduce task victimization the perfecting mechanism.

Implementation of Distributed Variable Chunk based Switching in Peer to Peer Network

The Peer-to-peer (P2P) computing has been one of the emerging technologies, particularly contributing in distributed file sharing. Experimental studies show that for a file download, network congestion or service capacity fluctuation takes minutes to several hours. For a P2P n/w one of the fundamental performance metrics is the average download time. The common approach to analyse the average download time is average service capacity. Heterogeneity and fluctuation have significant impact on service capacity and hence averages the download time. Random Chunk Based Switching is one of the file downloading scheme where, the file to be downloaded is divided into many chunks but the shortcomes of this scheme are mentioned below. User sequentially downloads one chunk at a time. If user gets stuck in a low service capacity peer, downloading a fixed amount of bytes from that peer may take a long time. Chunk size remains fixed and it does not change with time. We have designed and implemented a new scheme Distributed Variable Chunk Based Switching where chunk size changes with time. The downloader will be downloading the file from different peers. If bandwidth available is increased then downloading can complete before specified time. If bandwidth available is decreased then downloader will search another peer with good bandwidth and get it replaced. Our new scheme removes heterogeneity and fluctuation. It also provides a distributed approach to a sequential Random Chunk Based Switching.

Statistical Analysis of Compression Methods for Storing Binary Image for Low-Memory Systems

The paper is focused on the statistical comparison of the selected compression methods which are used for compression of the binary images. The aim is to asses, which of presented compression method for low-memory system requires less number of bytes of memory. For assessment of the success rates of the input image to binary image the correlation functions are used. Correlation function is one of the methods of OCR algorithm used for the digitization of printed symbols. Using of compression methods is necessary for systems based on low-power micro-controllers. The data stream saving is very important for such systems with limited memory as well as the time required for decoding the compressed data. The success rate of the selected compression algorithms is evaluated using the basic characteristics of the exploratory analysis. The searched samples represent the amount of bytes needed to compress the test images, representing alphanumeric characters.

Studying cost-sensitive learning for multi-class imbalance in Internet traffic classification

Cost-sensitive learning has been applied to resolve the multi-class imbalance problem in Internet traffic classification and it has achieved considerable results. But the classification performance on the minority classes with a few bytes is still unhopeful because the existing research only focuses on the classes with a large amount of bytes. Therefore, the class-dependent misclassification cost is studied. Firstly, the flow rate based cost matrix (FCM) is investigated. Secondly, a new cost matrix named weighted cost matrix (WCM) is proposed, which calculates a reasonable weight for each cost of FCM by regarding the data imbalance degree and classification accuracy of each class. It is able to further improve the classification performance on the difficult minority class (the class with more flows but worse classification accuracy). Experimental results on twelve real traffic datasets show that FCM and WCM obtain more than 92% flow g-mean and 80% byte g-mean on average; on the test set collected one year later, WCM outperforms FCM in terms of stability.

Analysis of mobile-oriented energy consumption for heterogeneous connections in hybrid wireless networks

While more and more mobile devices are equipped with both cellular and WLAN interfaces for internet access, the energy consumption aspect of these connections has not been studied in depth in the literature. In this paper, a hybrid network with three alternative wireless connections, namely, a cellular component, a combined component with a mixed ad hoc and cellular link, or an infrastructure-based WLAN component, is investigated. A distance-based analysis on the energy consumption of a mobile station has been performed for each alternative wireless connection, and corresponding numerical results have been obtained. The results suggest that, to increase link throughput while maintaining minimal power consumption, the remaining energy of the mobile station as well as the amount of bytes communicated over a link should be taken into consideration for connection selection. Furthermore, the remaining battery level of the mobile station could also be used as the criterion for handover decision, from both the mobile station's and the network operator's perspectives.

Optical smart packaging to reduce transmitted information

We demonstrate a smart image-packaging optical technique that uses what we believe is a new concept to save byte space when transmitting data. The technique supports a large set of images mapped into modulated speckle patterns. Then, they are multiplexed into a single package. This operation results in a substantial decreasing of the final amount of bytes of the package with respect to the amount resulting from the addition of the images without using the method. Besides, there are no requirements on the type of images to be processed. We present results that proof the potentiality of the technique.

Isolines: efficient spatio‐temporal data aggregation in sensor networks

AbstractThis paper introduces an energy‐efficient data collection technique that takes advantage of spatial and temporal data correlation for monitoring continuously changing conditions such as temperature, humidity, rain fall, radiation, substance concentrations, etc. The proposed technique, isoline aggregation, generates contour maps representing the condition being monitored. The resulting contour map consist of isolines which delimit regions within which the monitored condition is within a certain value range. Energy efficiency is achieved by taking advantage of the spatial and temporal correlation of the data field. Simulation results show that isoline aggregation can reduce the amount of bytes transmitted considerably. At the same time, we are able to keep high data accuracy. Copyright © 2007 John Wiley & Sons, Ltd.

A Study upon SNMP MIB II Algorithm: For the Calculation of the Line Utilization

This study proposes an algorithm of the maximum value accumulation method that uses the SNMP MIB II to calculate the line utilization on a network based on TCP/IP protocol. There are four types of algorithms to calculate it; the utilization accumulation method, the utilization midterm calculation method, the maximum calculation method, and the maximum accumulation method. The first two methods are not suitable to detect the faults or process the transmission delays in that they are to be followed by their line utilization, if applicable. On the contrary, the other two whose calculations are based on their accumulated amount of bytes, can be used to not only detect the faults but also compensate for the packet delays. The calculations of the line utilization have their practical uses in the capacity planning, the best calculation algorithm for which the maximum accumulation method would serve as. Its practicability includes coping with system faults, line and routing faults and wraparound of the MIB variables, along with its availability as an indicator for the bandwidth upgrade. The study includes its comparison of the latter two methods above by collecting the current traffic on a TCP/IP network to work on the characteristics of the proposed algorithm, as would help a network manager understand the current status of the line capacity to use series of data as an indicator in the line capacity planning.

Analysis of resource transfers in peer-to-peer file sharing applications using fluid models

This paper proposes a stochastic fluid flow model to compute the transfer time distribution of resources in peer-to-peer file sharing applications. The amount of bytes transferred among peers is represented by a continuous quantity (the fluid level) whose flow rate is modulated by a set of discrete states representing the concurrent upload and download operations on the peers participating to the transfer. A transient solution of the model is then performed to compute the probability that a peer can download a given resource in less than t units of time as a function of several system parameters. In particular, the impact of file popularity, bandwidth characteristics, concurrent downloads and uploads, cooperation level among peers, and user behavior are included in our model specification. We also provide numerical results aiming at proving the potentialities of the approach we adopted as well as to investigate interesting issues related to the effect of incentive mechanisms on the user cooperation.

Energy efficient MAC protocol with spatial reusability for wireless ad hoc networks

In this paper we propose a Spatial Reuse MAC (SRM) protocol based on the IEEE 802.11 which employs a combination of power control and a fully distributed scheme of transmission sneaking to achieve energy efficiency and spatial re-use in wireless ad hoc networks without using a separate control channel. Through extensive performance evaluation, we show that SRM considerably improves the total amount of bytes delivered per unit of energy as compared to existing solutions.