A key challenge for wireless networks in which nodes can move is for each node to keep track of its dynamically changing set of nearby nodes (neighbors). We present a solution for nodes to maintain neighbor knowledge ...
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ISBN:
(纸本)9781457702952
A key challenge for wireless networks in which nodes can move is for each node to keep track of its dynamically changing set of nearby nodes (neighbors). We present a solution for nodes to maintain neighbor knowledge where nodes communicate via wireless broadcast and are restricted to move on a two-dimensional road network. A road network is a collection of one-dimensional lines that may intersect each other. For nodes to exchange neighbor information, we construct a deterministic collision-free broadcast schedule which utilizes time division multiplexing and geographical segmentation. Under a certain node density requirement and assuming initial neighbor knowledge, our broadcast schedule tolerates node movement on the road network while providing deterministic guarantees in maintaining neighbor knowledge. We also provide a lower bound on the speed of a message propagation given our broadcast schedule. In addition, we consider grouping nodes into clusters and show that, under certain conditions, neighbor knowledge is maintained when two different clusters move close to each other. Finally, we address the issue of obtaining initial neighbor knowledge.
Assume that each vertex of an arbitrary n-vertex tree T is assigned a nonnegative integer weight. This paper considers partitioning the vertices of tree T into p disjoint clusters such that the total weight of each cl...
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ISBN:
(纸本)9780769548791
Assume that each vertex of an arbitrary n-vertex tree T is assigned a nonnegative integer weight. This paper considers partitioning the vertices of tree T into p disjoint clusters such that the total weight of each cluster is at least l and at most u, where l and u are given integers with l
In this paper, we present Automatic Network-based Testing Service (ANTS), a web service to verify functionality of a semiconductor intellectual property (IP) core or a system-on-a-chip (SoC), using computers attached ...
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ISBN:
(纸本)9781467329880;9781467329897
In this paper, we present Automatic Network-based Testing Service (ANTS), a web service to verify functionality of a semiconductor intellectual property (IP) core or a system-on-a-chip (SoC), using computers attached to network. ANTS system performs automated regression testing of IP/SoC cores whenever design change has been made. ANTS system manages a lot of computers and FPGA prototyping boards in computing farm or in an office. FPGA boards are initialized by ANTS automatically. Engineers use web browsers to control ANTS and to see the test results on the fly. We provide users with a skeleton code generator so that they can easily make their own verification projects/applications working on ANTS. One of automated tests with 25 ANTS computers becomes 100 times faster than manual execution of a single C-Model.
We consider the problem of reliably broadcasting information in a multihop asynchronous network that is subject to Byzantine failures. That is, some nodes of the network can exhibit arbitrary (and potentially maliciou...
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ISBN:
(纸本)9781457702952
We consider the problem of reliably broadcasting information in a multihop asynchronous network that is subject to Byzantine failures. That is, some nodes of the network can exhibit arbitrary (and potentially malicious) behavior. Existing solutions provide deterministic guarantees for broadcasting between all correct nodes, but require that the communication network is highly-connected (typically, 2k + 1 connectivity is required, where k is the total number of Byzantine nodes in the network). In this paper, we investigate the possibility of Byzantine tolerant reliable broadcast between most correct nodes in low-connectivity networks (typically, networks with constant connectivity). In more details, we propose a new broadcast protocol that is specifically designed for low-connectivity networks. We provide sufficient conditions for correct nodes using our protocol to reliably communicate despite Byzantine participants. We present experimental results that show that our approach is especially effective in low-connectivity networks when Byzantine nodes are randomly distributed.
There are considerations on the problem of time-consuming calculations in this article. This type of computational problems concerns to multiple aspects of earth sciences. distributed computing allows to perform calcu...
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ISBN:
(纸本)9783642312168
There are considerations on the problem of time-consuming calculations in this article. This type of computational problems concerns to multiple aspects of earth sciences. distributed computing allows to perform calculations in reasonable time. This way of processing requires a cluster architecture. The authors propose using Apache Hadoop technology to solve geophysics inversion problem. This solution is designed rather for analyzing data, but it also enables to perform computations. There is an architecture of solution proposed and real test carried out to determine the performance of method.
Computer simulations need a large amount of computational resources. We've believed that tightly-coupled computer is the first choice to perform the large scale simulations. This approach developing supercomputers...
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ISBN:
(纸本)9780769547374;9781467320016
Computer simulations need a large amount of computational resources. We've believed that tightly-coupled computer is the first choice to perform the large scale simulations. This approach developing supercomputers never allows users to execute the interactive simulations so far. Here, a real time simulation indicates an interactive or streaming supercomputing, not batch queue one. The advantage of the streaming can be found when users execute coupled simulations combining a number of different simulations. To overcome the conventional batch queue supercomputing, we consider the effect of the characteristics of the internet. We proposed a strategic streaming supercomputing model to estimate total cost of the coupled simulation in widely distributed computing environment.
With network developed quickly and used widely, how to store mass data has become a problem we have to face. Traditional methods usually add more servers into to increase computing speed and storage ability, while the...
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ISBN:
(纸本)9781467302395
With network developed quickly and used widely, how to store mass data has become a problem we have to face. Traditional methods usually add more servers into to increase computing speed and storage ability, while the hardware cost is very expensive and the storage efficiency is low. Through deep study of MapReduce programming model and Hadoop framework, this paper presented a mass data storage model based on Hadoop framework, then we designed and implemented a mass data storage system for campus network based on cloud computing. This system can effectively solved issues in mass data storage management in teaching and study. This system is cheap, easily operated, fast dealing and stable.
Advances in bioinformatics have contributed towards a significant increase in available information. Information analysis requires the use of distributed computing systems to best engage the process of data analysis. ...
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ISBN:
(纸本)9783642288388
Advances in bioinformatics have contributed towards a significant increase in available information. Information analysis requires the use of distributed computing systems to best engage the process of data analysis. This study proposes a multiagent system that incorporates grid technology to facilitate distributed data analysis by dynamically incorporating the roles associated to each specific case study. The system was applied to genetic sequencing data to extract relevant information about insertions, deletions or polymorphisms.
Capabilities are a more scalable and adaptive access control approach compared with the conventional approaches such as ACLs, due to their being held and managed by users or agents in systems, but not the middleware. ...
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ISBN:
(纸本)9781467344999
Capabilities are a more scalable and adaptive access control approach compared with the conventional approaches such as ACLs, due to their being held and managed by users or agents in systems, but not the middleware. This feature makes capabilities more suitable in distributed environments that have unstable populations. However capabilities have a simple structure that only supports independent and unbounded access rights, and this shows their weakness in complex cases. Treaties have been proposed to enhance the capability approach by introducing sequences of actions. In this way, treaties can capture characteristics of behaviours, and provide finer control over accesses. Treaties are also designed to be refinable by users, using the functionality provided by specific treaty operations. In this paper we introduce the concept of treaties and operations in more detail, proving that specific treaty operations maintain behavioural integrity.
Modern cloud-based applications (e.g., Facebook, Dropbox) serve a wide range of edge clients (e.g., laptops, smartphones). The clients' characteristics vary significantly in terms of hardware, operating systems, n...
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ISBN:
(纸本)9781467345651;9780769549033
Modern cloud-based applications (e.g., Facebook, Dropbox) serve a wide range of edge clients (e.g., laptops, smartphones). The clients' characteristics vary significantly in terms of hardware, operating systems, network connections, and software versions, just to name a few. Unfortunately, due to misconfiguration, outdated software, faulty hardware, or other reasons, many edge systems operate at suboptimal performance. Identifying poor performance and root causes is extremely challenging for the client of the cloud system. In this paper, we propose a novel troubleshooting service that leverages such heterogeneity to identify and debug performance problems on edge devices. First, by looking at many runs across many different clients, the service groups clients into different clusters based on performance. Next, the service enables logging on remote clients to collect run time traces, and subsequently identifies the root cause by analyzing logs automatically. We leverage high level features such as machine/OS type along with more low level kernel level statistics such as I/O rate and system calls. To demonstrate our system, we first introduce a configuration bug that was artificially injected in a recently built cluster by changing the TCP buffer size. Next, we present two real-life case studies, one related to I/O inefficiency on Android platform, and another misconfiguration bug in VirtualBox, that were identified using our tool.
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