75 research outputs found

    The Effects of Signal and Image Compression of SAR Data on Change Detection Algorithms

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    With massive amounts of SAR imagery and data being collected, the need for effective compression techniques is growing. One of the most popular applications for remote sensing is change detection, which compares two geo-registered images for changes in the scene. While lossless compression is needed for signal compression, the same is not often required for image compression. In almost every case the compression ratios are much higher in lossy compression making them more appealing when bandwidth and storage becomes an issue. This research analyzes different types of compression techniques that are adapted for SAR imagery, and tests these techniques with three different change detection algorithms. Many algorithms exist that allow large compression ratios, however, the usefulness of the data is always the final concern. It is necessary to identify compression methods that will not degrade the performance of change detection analysis

    Fault tolerant BeeHive routing in mobile ad-hoc multi-radio network

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    In this paper, fault tolerance in a multi-radio network is discussed. Fault tolerance is achieved using the BeeHive routing algorithm. The paper discusses faults added to the system as random fluctuations in hardware radio operation. The multi-radio nodes are designed using WiMAX and WiFi Radios that work in conjunction using traffic splitting to transfer data across a multi-hop network. During the operation of this network random faults are introduced by turning off certain radios in nodes. The paper discusses fault tolerance as applied to multi radio nodes that use traffic splitting in the transmission of data. We also propose a method to handle random faults in hardware radios by using traffic splitting and combining it with the BeeHive routing algorithm

    IOBR: Interoperable bee-hive routing in a heterogeneous multi-radio network

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    WiMAX and WiFi are the two proliferating wireless technologies with different physical and Media Access Control (MAC) layers. Today, WiFi radio is present in almost all the devices, and most of the devices are equipped with WiMAX radio. Both these technologies can be utilized, if the devices are equipped with both of them, to improve the performance. To cope up with the scenario, a method for routing in a heterogeneous infrastructure based mesh network is proposed. The heterogeneous network consists of a coordinator node and a subscriber node. In this paper, we assume that the coordinator nodes are equipped with both WiMAX and WiFi radios, whereas, the subscriber nodes need not have WiMAX radio. The protocol used for routing data is based on the bee-hive algorithm, in which the entire network is divided into foraging zones/regions. We propose a technique in which the intra-foraging zone communication happens through WiFi and the nodes across the foraging zone communicate via the coordinator using WiMAX. It is observed through simulations that our technique improves the overall network performance by making use of both the radios efficiently

    PARVIMONAS MICRA AND FUSOBACTERIUM NUCLEATUM SEPTIC ARTHRITIS: A RARE ANAEROBIC DOUBLE TROUBLE

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    Septic arthritis is a condition initiated by pathogenic inoculation of joints either by direct or hematogenous route, necessitating immediate medical attention. Among aerobic bacteria, Staphylococcus aureus and Streptococcus spp. are commonly found in association with septic joints. Anaerobes are very rarely involved in the causation of septic arthritis with an estimated rate of <1%. We are presenting a case of septic arthritis of knee joint by Parvimonas micra and Fusobacterium nucleatum, both being constituents of microbial flora in the oral cavity and gastrointestinal tract. Gram stain and anaerobic culture incorporated along with the aerobic culture of synovial fluid have played an important role in the preliminary diagnosis of anaerobic septic arthritis in this case

    DMN2SC: Detecting Malicious Nodes with 2-hop Secure Channel Support in Wireless Sensor Networks

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    Security in wireless sensor networks is critical due to its way of open communication. In this paper we have considered suite of attacks and provided a solution to detect malicious nodes. In literature, many schemes have been proposed to mitigate such attacks but very few detect the malicious nodes effectively and also no single solution detects all attacks. In the proposed approach, each node chooses the parent node for forwarding the packet towards Sink. Each node adds its identity as a routing path marker and encrypts only the bytes added by a node in packet before forwarding to parent. Child node observes the parent, handles acknowledgement from 2-hop distance node and decides the trust on parent based on successful and unsuccessful transactions. Data transmission is divided into multiple rounds of equal time duration. Each node sends a trust value report via multiple paths to Sink at the end of each round. Sink identifies the malicious node based on the number of packets a node participates in forwarding and also based on the trust value report sent from each node for its parent. Each node chooses the parent node at the beginning of a round based on its own observation on parent to recover itself from malicious parent node. With the combination of trust factor, 2-hop acknowledgement and fixed path routing to detect malicious activity, simulation results show that proposed method detect malicious nodes efficiently and early, and also with low percentage of false detection, compared to other recently proposed approaches

    EFFECT OF ETHANOLIC EXTRACT OF CYANOTIS CRISTATA LEAVES APPLIED TOPICALLY ON WOUND HEALING IN WISTAR RATS

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      Objective: The objective of this study was to assess the effect of ethanolic extract of Cyanotis cristata leaves when applied topically on healing of wound in Wistar rats.Methods: C. cristata leaves were evaluated for its effect on healing of wound in three models, namely, incision, excision, and burn wound. Each model included five groups, each consisting of 6 rats. The five groups were as follows: Group I rats (control and ointment base), Group II rats (standard and silver sulfadiazine), and Group III, Group IV, Group V (treated with C. cristata extract ointment of 0.5%, 1%, and 2%, respectively). Variables evaluated included breaking strength in incision wound while it was contraction rate and epithelialization in excision and burn wound. One-way analysis of variance and Tukey's post hoc test was used to analyze data.Result: In incision wound, breaking strength in test group was significantly increased (p<0.001) as compared to control. In excision and burn wound of test group, time to epithelialization and contraction rate was significantly decreased (p<0.001). The granulation tissue from excision and burn wound showed increased collagen and less inflammatory cells in test groups in comparison to the control.Conclusion: The ethanolic extract of leaves of C. cristata, when applied topically, enhanced wound strength and accelerated healing of incision, excision, and burn wounds in rats

    CFT: Co-operative file transfer algorithm for multi network interface sessions

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    File transfer is one of the important operations on the Internet. Generally files are transferred from one machine to another machine through one interface. File transfer can occur through multiple interface connections also. Protocols such as SCTP, transfers data in multiple data stream within a single connection and LFTP transfers file sourced from multiple servers to a single host. Here, we present the concept of using multiple network interfaces for transferring files from a single server. This would ensure the utilization of combined bandwidth of all the interfaces used, so that the rate of file transfer would increase considerably compared to single bandwidth transfer. In this work, we use two interfaces i.e, IEEE 802.3 (Ethernet) and IEEE 802.11 (WiFi) to accomplish the above task. We use a non pre-emptive context switching framework Twisted where threading is avoided for an effective resource utilization. The required file is downloaded utilizing two interfaces instead of one unlike normal file transfer. We analyze the improvement in performance by observing the time taken to download a file using two different interfaces (Ethernet and WiFi) and comparing that with a single interface download (using either Ethernet or WiFi) in real time scenario. We attempt to deal with the issue of when and how to connect through two interfaces which combines the bandwidths of both these interfaces, aiding in improving the performance of file transfer when compared to file transfer using single interface

    Throughput Analysis in an Infrastructure-based Mesh Network using BeeHive Algorithm

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    WiMAX and WiFi are among the major wireless technologies escalating today. Both these technologies provide last mile connectivity and differ in their Media Access Control (MAC) layer and physical (PHY) layers. Since most of the devices are equipped with WiFi, and WiMAX is prevailing in today’s devices, an efficient way of routing the data is by making use of both these technologies simultaneously. This work presents such a technique based on the Bee-hive routing algorithm for an infrastructure-based mesh network, which promotes interoperability between the WiMAX and WiFi technologies. The network consists of two types of nodes-1) coordinator node 2) subscriber node, and divides the entire network into regions called foraging regions/zones based on the hop count from the coordinator node. A detailed implementation of this algorithm is presented in this work. The algorithm is tested for various mobile and static topologies by varying the parameters such as the speed of motion of the mobile nodes and the hop limit

    Analysis of Throughput in Infrastructure based Multi-Radio Network

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    This paper deals with the design of an infrastructure based network consisting of Multi-radio Hybrid mobile nodes that perform traffic splitting over the network. The multi- radio mobile nodes have a WiMAX and a WiFi Radio that are used in transmitting data traffic over two different radio channels. Data traffic is split statically over a node and transmitted over the two radio channels. We analyse the Throughput and End-to-End delay for data transmission in the network

    Performance analysis of bee-hive routing in multi-radio networks

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    In recent years, wireless communication technology has reduced the distance between people and has hence become a significant part of our lives. Two such technologies are WiFi(IEEE 802.11) and WiMAX(IEEE 802.16) where the latter is a long range system covering many kilometers, whereas former is a synonym for WLAN providing a coverage of only short ranges. This work describes the implementation of a framework in which a multi-hop, ad-hoc network is deployed with hybrid nodes to enhance network throughput. The data traffic received is split between the WiFi and WiMAX radios on the basis of th e split coefficient value statically. The routing algorithm being implemented in this paper is the be e-hive algorithm. Bee-hive algorithm is a multi-path routing algorithm inspired by the social behavior of swarms of bees. It is dynamic, robust and flexible yet simple algorithm which can prove helpful for optimal
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