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The throughput of conventional wireless multicast systems is limited by the multicast user with the lowest channel quality, which leads to a very low throughput especially if the number of users is large. In this paper, we show that hybrid-automatic repeat request with Chase combining (HARQ-CC) is a promising technique to overcome this problem and optimize the transmission rate of wireless multicast...
Recently, various wireless networks are emerging and it leads to spectrum congestions. Cognitive radio, which allows users of the emerging wireless networks to opportunistically utilize the unused bands of the existing primary systems, can alleviate this problem. As one of the emerging wireless networks, 802.16 networks are suggested to explore TV “White Space” and then it is necessary to study cognitive...
The seamless integration of heterogeneous wireless access networks is currently one of the issues of major interest in the field of telecommunication systems. In an early future technologies like UMTS, WLAN and WiMAX will give broadband access to users that perform their voice/video calls or data sessions without knowledge of the specific technology their terminals are using, following the paradigm...
The problem of dynamic Quality of Service (QoS) management for multimedia services has been addressed from two complementary, yet interrelated directions; one mainly dealing with designing adaptive or “elastic” services, and the other, dealing with “smarter” resource allocation. We adopt this approach in this paper, by performing a graceful quality degradation and the corresponding resource (re)allocation...
In this paper we propose a radio problem detection based rescue handover for 3G Long Term Evolution (LTE). The radio problem detection based handover algorithm takes advantage of already existing Radio Link Failure (RLF) detection mechanism specified in 3GPP for LTE. In coverage limited scenarios as well as challenging interference and mobility conditions, the event triggered handover measurement...
In this paper we show how game theory and Gibbs sampling techniques can be used to design a self-optimizing algorithm for minimizing end-to-end delays for all flows in a multi-class mobile ad hoc network (MANET). This is an improvement over the famed Ad-Hoc On-demand Distance Vector (AODV) protocol, that computes the routes with minimal number of hops for each flow in a multi-flow ad-hoc network....
The self-installation nature of femtocells sharing the same frequency band can lead to harmful femto-to-femto interference levels. The possibility for operators to share its licensed spectrum allows femtocells of one operator to exploit the frequency resources of other operators. In this paper we propose and analyze the performance of two dynamic frequency selection algorithms that permit to the generic...
Energy efficiency becomes evergreen than ever before. Over the last few years a significant research in wireless communications, aiming to enhance communications efficiency subject to constraint of power consumption, has given rise to optimization techniques of power control and management in wireless networks. Although the initial target was the utilization of resources in order to exploit communications...
Real-world social networks from a variety of domains can naturally be modelled as dynamic graphs. However, approaches to detecting communities have largely focused on identifying communities in static graphs. Recently, researchers have begun to consider the problem of tracking the evolution of groups of users in dynamic scenarios. Here we describe a model for tracking the progress of communities over...
The vertex-betweenness centrality index is an essential measurement for analyzing social networks, but the computation time is excessive. At present, the fastest algorithm, proposed by Brandes in 2001, requires O(|V| |E|) time, which is computationally intractable for real-world social networks that usually contain millions of nodes and edges. In this paper, we propose a fast and accurate algorithm...
This article investigates the dynamic features of social tagging vocabularies in Delicious, Flickr and YouTube from 2003 to 2008. It analyzes the evolution of the usage of the most popular tags in each of these three social networks. We find that for different tagging systems, the dynamic features reflect different cognitive processes. At the macro level, the tag growth obeys power-law distribution...
Given a dataset comprising a temporal sequence of communications between actors, how can we visualize the `flow' of communication over time? Current practice transforms the dataset into a dynamic graph - vertices represent the actors and directed edges represent the communications. The directed edges are added and removed over time. There are then several approaches to visualizing dynamic graphs that...
Cluster analysis describes the division of a dataset into subsets of related objects, which are usually disjoint. There is considerable variety among the different types of clustering algorithms. Some of these clustering algorithms represent the dataset as a graph, and use graph-based properties to generate the clusters. However, many graph properties have not been explored as the basis for a clustering...
The paper is reviewing the new trends of the image sensing, the Super CCDs and the Backlit CMOS. One proposes a new HDR fuzzy-interpolative algorithm that can extend the dynamic range of a still Backlit CMOS image in the Super CCD SR manner: the fusion of two images, the first one with a normal exposure and the other underexposed.
This paper proposes a new method to cluster law texts based on referential relation of laws. We extract law entities (an entity represents a law) and their referential relation from law texts. Then SimRank algorithm is applied to calculate law entity's similarity through referential relation and law clustering is carried out based on the SimRank similarity. This is the first time to apply SimRank...
Grid is evolving to a more efficient global computing infrastructure by introducing more and more task scheduling algorithms. With the grid expansion and users' requirements in an intuitive way, a new robust multi-criteria scheduling algorithm is needed. Resource brokers should provide a more comprehensive solution for users. Multiple scheduling criteria addressed by the related grid research include...
Based on the analysis that H.Agrawal's slicing algorithm produced imprecise result for Circular program, from which a conclusion was drawn that the reason for the imprecision was that the dependence relation of the relied graph was defined too coarsely. Upon which, dynamic program slice algorithm of optimizing dependence was proposed, the connection of the states in a program can be denoted by arrival...
Currently, a large number of clustering algorithms are available for data mining. But it will be difficult for people who to a large extent know little about data mining to select an appropriate clustering algorithm. In order to solve this problem, in this paper, we first comprehensively analyze a number of clustering algorithms, then summarize their evaluation criteria and apply the so-called fuzzy...
Advances in speech technology and computing power have created a surge of interest in the practical application of speech recognition. The main goal of this paper is to facilitate recognition accuracy, with emphasis on acoustic and language modeling. With the Dynamic time warping algorithm, recognition of speech commands and generation of the commands for desktop items activation has been done in...
Chaos sequence produced by the chaos system existence of defects of the probability distribution non-uniform, that easily cause the system to be identified attack. By analyzing the value probability distribution in different number position which in chaos sequence, proposed to the chaos sequence kinetic property improvement algorithm. After the improvement chaos sequence distribution is even, has...
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