11 research outputs found

    A new fair marker algorithm for DiffServ networks

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    Internet Engineering Task Force (IETF) has proposed many new technologies to cover the new real time applications which have become very important in today's Internet demands. One such technology is Differentiated Services (DiffServ). DiffServ routers provide Per Hop Behaviors (PHBs) to aggregate traffic for different level of services. There is an unfairness problem that occur in a DiffServ networks. In this paper an improved version of the time sliding window three color marker is proposed and analyzed. The proposed algorithm is based on the adaptability concept of changing the constant value in the previous version of the algorithm (ItswTCM), in other words, changing the limit for the constant value without affecting the simplicity of the algorithm. The paper design and implement the algorithm with extensive simulations using NS-2 simulator to compare the proposed algorithm with previous algorithms. Results show that our new marker performs better than previous algorithms such as srTCM, trTCM, tswWTCM and ItswTCM in terms of fairness and number of yellow packets injected to the network in proportion to the committed rate

    Parallel implementation for HSLO(3)-FDTD with message passing interface on distributed memory architecture

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    Finite-Difference Time-Domain (FDTD) method is a numerical method that can be used to solve electromagnetic problems in time domain. However, this method needs large computer memory and long execution time. Recently, a new scheme of FDTD has been develop which is called the High Speed Low Order (3) FDTD (HSLO(3)-FDTD) method which reduced the speed of FDTD method by 67%. In this paper, we develop the parallel distributed version of the HSLO (3)-FDTD method on Distributed Memory Architecture Machine (Sunfire V1280) with message passing interface. We execute some numerical simulations by a new method with direct-domain (DD) approach to simulate one dimensional free space wave propagation represented by a Gaussian pulse. The simulation is conducted on 2 meter of solution domain truncated by a perfectly conducting boundary condition. The performance of the new schemes are analyzed and compared with the conventional parallel FDTD method in terms of processing time, speed-up, efficiency and cost. The new schemes is shown to be ultra-fast and very efficient with some superlinear speed-up

    New approach of solving time-domain free space wave propagation

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    In this paper, a numerical simulation by a new high speed low order FDTD (HSLO-FDTD) method will be conducted to simulate one dimensional free space wave propagation of 2.4 GHz Gaussian pulse. The efficiency of the new schemes are analyze and compared with the standard FDTD method in terms of processing time, phase velocity and global error. The amplitude in volts by both methods is also displayed. Results obtained using the new schemes compare well with published results and solve the problem faster than the standard FDTD method

    Increasing packet delivery in Ad hoc On-Demand Distance Vector (AODV) routing protocol

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    Broadcasting in the route discovery and the route maintenance of Ad hoc On-demand Distance Vector (AODV) routing protocol provokes a high number of unsuccessful packets deliveries from the source nodes to the destination nodes. Studies have been undertaken to optimize the rebroadcast focused on the route discovery of the AODV. In this study, lifetime ratio (LR) of the active route for the intermediate node is introduced to increase the number of unsuccessful packets delivery. Simulation results focused on the improvement of the packet delivery in the routing protocol compared to standard AODV. The performance metrics are measured by varying the number of nodes and the speeds. The OMNET++ is used to simulate the performance of the metrics

    Protocols for secure routing and transmission in mobile ad hoc network: a review

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    Mobile ad hoc network security is a new area for research that it has been faced many difficulties to implement. These difficulties are due to the absence of central authentication server, the dynamically movement of the nodes (mobility), limited capacity of the wireless medium and the various types of vulnerability attacks. All these factor combine to make mobile ad hoc a great challenge to the researcher. Mobile ad hoc has been used in different applications networks range from military operations and emergency disaster relief to community networking and interaction among meeting attendees or students during a lecture. In these and other ad hoc networking applications, security in the routing protocol is necessary to protect against malicious attacks as well as in data transmission. The goal of mobile ad hoc security is to safeguard the nodes’ operation and ensure the availability of communication in spite of adversary nodes. The node operations can be divided into two phases. The first phase is to discover the route (s) path. The second phase is to forward the data on the available discovered routes. Both stages need to protect from attacks; so many protocols have been proposed to secure the routing and data forwarding. This is a review study to mobile ad hoc protocols for securing routing as well as protocols for securing packets forwarding. Furthermore, it will present the characteristics and the limitations for each protocol and attributes

    Hydroxyproline determination for initial detection of halal-critical food ingredients (gelatin and collagen)

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    Gelatin and collagen are considered halal-critical ingredients as they are typically derived from either bovine or porcine animals. Current analytical methods for determining the sources of gelatin and collagen suffer from limitations in terms of robustness and false positives in peptide matching. Thus, the aim of this study was to investigate the utility of monitoring hydroxyproline, a signature amino acid for gelatin and collagen, for identifying potentially haram foodstuffs. To determine the hydroxyproline profiles among animal- and plant-based samples, one-way univariate analysis of variance followed by pair-wise comparison was used to establish statistical significance. Multivariate chemometric analysis through principal component analysis revealed a discrete distribution pattern among 59 samples due to hydroxyproline variability. Finally, inter- and intra-laboratory comparisons demonstrated the validity and robustness of hydroxyproline determination according to ISO 17025. Thus, this preliminary identification technique will aid the identification of potentially haram foodstuffs

    Comparative study of congestion control techniques in high speed network

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    Due to enhancement of broadband infrastructure, many multimedia applications such as streaming media, IPTV, video conference, online gaming and video surveillance are emerging. These video streaming generally require high bandwidth but are not responding to network congestion. And most of them prefer timeliness to reliability. TCP seems not suitable to real time applications because it rather focuses on ensuring data transmission. Currently most of the applications are using UDP, but UDP is lacking of congestion protocol and no guarantee of packet delivery. DCCP is a new transport protocol being standardized by IETF that provides unreliable congestion controlled flows of data packets. In this paper, we compare the behavior of congestion control of these transport protocol by manipulating the queue size, link capacity and packet delay. Network Simulator NS-2 was used to evaluate the network scenarios

    Face detection in thermal imaging using head curve geometry

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    This paper presents an effective method to detect face in thermal imaging. It utilises the head curve geometry to extract the face from the images. Thermal imaging system is chosen due to its inherent nature of being immune towards drastic ambient light changes. A detailed face detection algorithm is explained in the paper, together with the performance comparison. Several conditions have to be fulfilled prior to the face detection. There should be one person facing the camera and no other external heat-emitting objects are captured by the camera. Overall, the face detection method demonstrates a high accuracy, which is 90.68% for the near images, 92.12% for the far images and 91.4% as an overall

    Fuzzy Logic Based Viola Jones Fever Detection Method in Thermal Imaging System

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    This paper presents an effective automated fever detection method in thermal imaging system. It utilizes the Viola Jones method for eye detection, mean sample method for canthus region detection and fuzzy logic based for fever classification. It integrates the Viola Jones eye localization method, mean sample canthus region detection method and fuzzy logic based fever classification method into an automated fever detection algorithm to be applied in thermal imaging system on contactless human body temperature measurement. The detailed fever detection algorithm is explained in the paper explain in this paper with proper experimental results. Several conditions have to be fulfilled prior to the fever detection. There should be one person facing the thermal camera and no other external heat-emitting objects in background are captured by thermal camera. Overall, the fever detection method demonstrates 63% of accuracy
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