The Farsite distributed file system provides availability, by replicating each file onto multiple desktop computers. Since this replication consumes significant storage space, it is important to reclaim used space whe...
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ISBN:
(纸本)0769515851
The Farsite distributed file system provides availability, by replicating each file onto multiple desktop computers. Since this replication consumes significant storage space, it is important to reclaim used space where possible. Measurement of over 500 desktop file systems shows that nearly, half of all consumed space is occupied by duplicate files. We present a mechanism to reclaim space from this incidental duplication to make it available for controlled file replication. Our mechanism includes 1) convergent encryption, which enables duplicate files to coalesced into the space of a single file, even if the files are encrypted with different users' keys, and 2) SALAD, a Self-Arranging, Lossy, Associative Database for aggregating file content and location information in a decentralized, scalable, fault-tolerant manner. Large-scale simulation experiments show that the duplicate-file coalescing system is scalable, highly, effective, and fault-tolerant.
Adaboost algorithm is difficult to implement on embedded platform for real-time face detection by software due to its high computation load and data throughput. This article presents a cell array architecture using pa...
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ISBN:
(纸本)9781424442331
Adaboost algorithm is difficult to implement on embedded platform for real-time face detection by software due to its high computation load and data throughput. This article presents a cell array architecture using parallel technology. Detection procedure can be greatly speeded up with its multi-pipeline. Besides it makes use of the continuity of image data to decrease the accesses to RAM This article uses Electronic System Level (ESL) tools to develop and simulate a cycle-accurate model of the cell array architecture. The result shows that cell array architecture with 200MHz clock can process 12 million HAAR features per second and detect faces on a 176*144 image at the frame rate of 103 frames per second, which is 14 times speedup compared with software implementation.
In this paper, we propose an algorithm to minimize the multihop route from each sensor node to a sink node in wireless sensor networks with multiple sink nodes. In addition to solving the shot-test path problem, the a...
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ISBN:
(纸本)9781424442331
In this paper, we propose an algorithm to minimize the multihop route from each sensor node to a sink node in wireless sensor networks with multiple sink nodes. In addition to solving the shot-test path problem, the algorithm solves a time slot problem to support TDAM (time division multiple access) communication. TDMA is effective for avoiding packet collisions;however, the time slot allocation itself is a difficult problem to solve. We introduce a distributed coloring algorithm to solve it. After describing the algorithm, some experimental results proving its effectiveness are presented
Many visions of the future predict a world with pervasive computing, where computing services and resources permeate the environment. In these visions, people will it,ant to execute a service on any available device w...
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ISBN:
(纸本)0769515851
Many visions of the future predict a world with pervasive computing, where computing services and resources permeate the environment. In these visions, people will it,ant to execute a service on any available device without worrying about whether the service has been tailored for the device. We believe that it it-ill be difficult to create services that can execute well on the wide variety of devices that are being developed because of problems with diversity and resource constraints. We believe that these problems can be greatly reduced by using an ad-hoe distributed platform to transparently offload portions of a service from a resource-constrained device to a nearby, server. We have implemeted a preliminary prototype and emulator to study this approach. Our experiments show the beneficial use of nearby resources to relieve both memory and processing constraints, when it is appropriate to do so. We believe that this approach will reduce the burden on developers by masking more device details.
The provision of telemedicine services involves integration of information, humun-machine and health care technologies, As different modalities of patient care require applications running on heterogeneous computing e...
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ISBN:
(纸本)078036466X
The provision of telemedicine services involves integration of information, humun-machine and health care technologies, As different modalities of patient care require applications running on heterogeneous computing environments, distributed health care applications are a major issue in telemedicine. A distributed application integrates resources located at distant places through networking. These resources include diagnostic instruments, medical expertise, hospital care and other related administrative services In health rare applications. A workflow based methodology fur development and implementation of distributed health care applications is presented, The workflow methodology involves process modeling, workflow design and implementation, and system evaluation, Using the specific example of a distributed telecardiology application, issues related to workflow management are reviewed and a design methodology to develop a distributed telecardiology system is proposed. The ECC process includes;data acquisition;encoding, transmission and storage;pattern recognition and feature extraction;and diagnostic classification. The key identified elements of the workflow implementation are;the point of need user;the assessor In tie online diagnostic center;ECC;knowledge repositories;online specialist and the further care center. As illustrated through the telecardiology case study, the proposed methodology can be effectively used as a guideline to develop distributed health care applications In other telecare areas.
The fundamental paradigm of context-aware computing has lead to a diversity of conceivable context-based applications. In order to support these applications, efficient and scalable context management platforms have b...
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ISBN:
(纸本)9781424442331
The fundamental paradigm of context-aware computing has lead to a diversity of conceivable context-based applications. In order to support these applications, efficient and scalable context management platforms have become utterly important. In this paper we propose a layered reference model that encapsulates suitable abstractions to tackle the complexity of context management in mobile ad-hoc networks. For each layer we outline strategies and mechanisms we have developed to manage context information efficiently so that it can readily be used by context-based services and applications in these networks. In addition, we discuss refinements of the current model that we currently investigate, which are related to data semantics such as context quality and expressive location models, performance enhancement by adaptation, and aspects regarding the integration of ad-hoc context management with infrastructure-based systems leading to a hybrid system structure.
This paper proposes a data propagation method for improving data availability in ad hoc networks in which nodes are locally distributed. Our method makes use of a special mobile terminal which moves to transfer data i...
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ISBN:
(纸本)9781424442331
This paper proposes a data propagation method for improving data availability in ad hoc networks in which nodes are locally distributed. Our method makes use of a special mobile terminal which moves to transfer data items. Moreover the mobile terminal propagates data items effectively by deciding the moving route considering the length of the route, access requests issued by nodes, and data items held by nodes. Furthermore, we verify the effectiveness of our method by simulation experiments.
Mobile teamwork applications are often deployed in heterogeneous environments with various devices and connections. To support a broad variety of platforms for mobile teamwork in heterogeneous environments, this paper...
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ISBN:
(纸本)0769515886
Mobile teamwork applications are often deployed in heterogeneous environments with various devices and connections. To support a broad variety of platforms for mobile teamwork in heterogeneous environments, this paper presents a framework for development of applications adaptive to the client's computing platform. The framework supports both shared data adaptation and user interface adaptation to user's preferences and display characteristics. Both shared data and the user interface are specified in two XML documents. The user interface XML document specifies the application interface by a generic "view" graph (should also specify the valid data types). Global view graph is transformed into a device-dependant view graph for individual client devices.
Making the network programmable simplifies network management and enables network innovations. The Recursive InterNetwork Architecture (RINA) is our solution to enable network programmability. ProtoRINA is a user-spac...
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ISBN:
(纸本)9781479962044
Making the network programmable simplifies network management and enables network innovations. The Recursive InterNetwork Architecture (RINA) is our solution to enable network programmability. ProtoRINA is a user-space prototype of RINA and provides users with a framework with common mechanisms so a user can program recursive-networking policies without implementing mechanisms from scratch. In this paper, we focus on how routing policies, which is an important aspect of network management, can be programmed using ProtoRINA, and demonstrate how ProtoRINA can be used to achieve better performance for a video streaming application by instantiating different routing policies over the GENI (Global Environment for Network Innovations) testbed, which provides a large-scale experimental facility for networking research.
The computing disciplines and the computing profession continue to appear gender segregated;despite limited progress, the number of women in computing still remains a minority. Differences persist at all levels, parti...
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The computing disciplines and the computing profession continue to appear gender segregated;despite limited progress, the number of women in computing still remains a minority. Differences persist at all levels, particularly when women attempt to reach higher levels of the corporate hierarchy. Today's social networking and friendly-computing provide an opportunity to redesign curricula to better engage young women in pursuing degrees and careers in computing. This may in turn increase participation and engagement and transform the study of computing from an isolated experience to an always-connected and socially-rich one.
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