Bloom Filter is a simple space-efficient randomized data structure for representing a set in order to support membership queries, which uses an m-bit array to represent a data set. In order to support representing dyn...
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Wireless sensor networks are often densely deployed for environmental monitoring applications. Collecting raw data from these networks can lead to excessive energy consumption. Thus using the spatial and temporal corr...
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ISBN:
(纸本)9783540730897
Wireless sensor networks are often densely deployed for environmental monitoring applications. Collecting raw data from these networks can lead to excessive energy consumption. Thus using the spatial and temporal correlations that exist between adjacent nodes we appoint a few as representative nodes that perform in-network aggregation. This reduces the total number of transmissions. Our distributed scheduling algorithm autonomously assigns a particular node to perform aggregation and reassigns schedules when network topology changes. These topology changes are detected using cross-layer information from the underlying MAC layer. We also present theoretical performance estimates and upper bounds of our algorithm and evaluate it by implementing the algorithm on actual sensor nodes, demonstrating an energy-saving of up to 80% compared to raw data collection.
The imminent mass deployment of pervasive computing technologies such as sensor networks and RFID tags, together with the increasing participation of the Web community in feeding geo-located information within tools s...
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ISBN:
(纸本)9780769527840
The imminent mass deployment of pervasive computing technologies such as sensor networks and RFID tags, together with the increasing participation of the Web community in feeding geo-located information within tools such as Google Earth, will soon make available an incredible amount of information about the physical and social worlds and their processes. Overall, both the above trends contribute to the forming of a decentralized infrastructure that, by accumulating and making available in a ubiquitous way detailed digital information about the surrounding world, opens up the possibility of conceiving innovative context-aware services for "browsing the world" around us, as well as of enhancing the quality and effectiveness of current ICT services via context-awareness and dynamic personalization. However, this will also introduce a dramatic complexity increase in data and service management, making impossible for humans to stay in the control loop and directly manage the configuration and functioning of these systems, and compulsory calling for unsupervised self-organizing approaches at both the data and the service level. On the one hand, proper self-organizing approaches must be defined for processing and aggregating large amounts of data into a meaningful and manageable "world model" to be made available to services. On the other hand, proper distributedcomputing models and infrastructures must be defined to enable services to exploit such information to self-organize their distributed and context-aware activities at the best. In this talk, after having introduced my general vision of future pervasive computing scenarios, I try to identify the key research challenges that should be faced towards the effective provisioning of self-organizing and context-aware services in such scenarios, and will sketch some possibly promising research directions currently being investigated within the "Agents and Pervasive computing Group" of the Universita di Modena e Reggio Emil
distributed applications running on clusters may be composed of several components with very different performance requirements. The FIowVR middleware allows the developer to deploy such applications and to define com...
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ISBN:
(纸本)9783540747833
distributed applications running on clusters may be composed of several components with very different performance requirements. The FIowVR middleware allows the developer to deploy such applications and to define communication and synchronization schemes between components without modifying the code. While it eases the creation of mappings, FlowVR does not come with a performance model. Consequently the optimization of mappings is left to the developer's skills. But this task becomes difficult as the number of components and cluster nodes grow and even more complex if the cluster is composed of heterogeneous nodes and networks. In this paper we propose an approach to predict performance of FIowVR distributed applications given a mapping and a cluster. We also give some advice to the developer to create efficient mappings and to avoid configurations which may lead to unexpected performance. Since the FlowVR model is very close to underlying models of lots of distributed codes, our approach can be useful for all designers of such applications.
Wireless ad hoc networks are consisted of mobile nodes with limited bandwidth, computing ability and energy, which is different from the traditional wired networks. On demand routing protocols are proposed for this ty...
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ISBN:
(纸本)9783540735489
Wireless ad hoc networks are consisted of mobile nodes with limited bandwidth, computing ability and energy, which is different from the traditional wired networks. On demand routing protocols are proposed for this type of network, and they scale well with the topology of ad hoc network. But due to lack of knowledge of global topology and the mobility of nodes, they may be not optimal. We propose a Neighbor-Aware Optimizing Routing algorithm (called NAOR) based on SHORT [1] which uses hop comparison array to optimize the routing protocol. Our NAOR algorithm solves those special cases which SHORT fails to handle. Finally, we use ns-2 simulator to evaluate the performance of AODV, AODV using SHORT and AODV using NAOR. The results show that NAOR gets better improvement on performance such as delivery rate and latency than SHORT.
Service sharing and discovery play a relevant role in mobile ad hoc environments. Upon joining a self-organizing network, mobile nodes should be able to explore the environment to learn about, locate, and share the av...
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ISBN:
(纸本)9783540747833
Service sharing and discovery play a relevant role in mobile ad hoc environments. Upon joining a self-organizing network, mobile nodes should be able to explore the environment to learn about, locate, and share the available services. In this paper, we propose a distributed and scalable service discovery and sharing framework for ad hoc networks. The proposed framework defines three types of nodes: service directories, service providers and requesting nodes. Service directory nodes act as mediators for lookup requests from requesting nodes. Joining service provider nodes register their services with the nearest service directory. A requesting node discovers the available services by submitting requests to its nearest service directory which determines the node providing the requesting service. The performance of the proposed model is evaluated and compared to the broadcast-based model that has been extensively studied in the literature.
The proceedings contain 44 papers. The discussed topics include: performance analysis of interconnection networks under bursty and batch arrival traffic;a lazy EDF interrupt scheduling algorithm for multiprocessor in ...
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ISBN:
(纸本)9783540729044
The proceedings contain 44 papers. The discussed topics include: performance analysis of interconnection networks under bursty and batch arrival traffic;a lazy EDF interrupt scheduling algorithm for multiprocessor in parallelcomputing environment;a time and interaction model for open distributed timing computation;efficient linkable ring signatures and threshold signatures from linear feedback shift register;an improved algorithm for Alhusaini's algorithm in heterogeneous distributed systems;a framework of software component adaptation;data interoperation between ChinaGrid ad SRB;method for computational grids resources allocate based on auction and utility analyses;automatic conceptual indexing of web services and its application to service retrieval;on-demand capacity framework;implementing digital right management in P2P content sharing system;and a generalized critical task anticipation technique for DAG scheduling.
We propose a distributed coalition formation strategy for collaborative sensing tasks in camera sensor networks. The proposed model supports task-dependent node selection and aggregation through an announcement/biddin...
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ISBN:
(纸本)9783540730897
We propose a distributed coalition formation strategy for collaborative sensing tasks in camera sensor networks. The proposed model supports task-dependent node selection and aggregation through an announcement/bidding/ selection strategy. It resolves node assignment conflicts by solving an equivalent constraint satisfaction problem. Our technique is scalable, as it lacks any central controller, and it is robust to node failures and imperfect communication. Another unique aspect of our work is that we advocate visually and behaviorally realistic virtual environments as a simulation tool in support of research on large-scale camera sensor networks. Specifically, our visual sensor network comprises uncalibrated static and active simulated video surveillance cameras deployed in a virtual train station populated by autonomously self-animating pedestrians. The readily reconfigurable virtual cameras generate synthetic video feeds that emulate those generated by real surveillance cameras monitoring public spaces. Our simulation approach, which runs on high-end commodity PCs, has proven to be beneficial because this type of research would be difficult to carry out in the real world in view of the impediments to deploying and experimenting with an appropriately complex camera network in extensive public spaces.
A new coordination language for distributed data-parallel programs is presented, call SNet. The intention of SNet is to introduce advanced structuring techniques into a coordination language: stream processing and var...
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ISBN:
(纸本)9783540708803
A new coordination language for distributed data-parallel programs is presented, call SNet. The intention of SNet is to introduce advanced structuring techniques into a coordination language: stream processing and various forms of subtyping. The talk will present the organisation of SNet, its major type inferencing algorithms and will briefly discuss the current state of implementation and possible applications.
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