In traditional grid, grid user can not validate whether grid service registered in grid platform can execute correctly or not because the system does not provide the measurement mechanism for grid service. In order to...
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In traditional grid, grid user can not validate whether grid service registered in grid platform can execute correctly or not because the system does not provide the measurement mechanism for grid service. In order to solve this problem, we propose a series of strategies and methods for trusted grid. These strategies and methods include: an access control policy for reference database, an integrity attestation for reference datasheet, a construction method of reference datasheet, a trusted storage algorithm of reference datasheet and a report algorithm of reference datasheet. All these constitute the measurement mechanism of service for trusted grid. Some experiments are done in order to validate the feasibility and the availability of this mechanism. The results show that it is feasible and efficient to validate whether grid service registered in trusted grid platform can execute correctly or not.
The research about the interaction between grid environments and users is becoming popular. Many scientists propose the integration for Web 2.0 technologies and gridcomputing. In this paper, we propose a flexible Web...
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The research about the interaction between grid environments and users is becoming popular. Many scientists propose the integration for Web 2.0 technologies and gridcomputing. In this paper, we propose a flexible Web-based framework for grid applications - WAGA, which tries to bridge the gap between grid middleware and grid applications. WAGA provides a WYSIWYG (what you see is what you get) way for the programming for grid applications by adopting participation, interaction and sharing features of Web 2.0 technology. With WAGA, a grid user is able to use the grid resources and to develop grid applications without understanding the underlying complexity of grids. WAGA is composed with a Web GUI (called WAGA-designer) and someWeb-based APIs. WAGA-designer is used by grid users to develop application-based Web portal, and the WebAPIs are used by the WAGA-designer. The use case study shows that WAGA is flexible for grid users, and the performance evaluation shows that WAGA works with high efficiency.
This paper proposes a novel parallel data transfer mechanism to improve the performance of data transfer in grid environment. It utilizes the servers distributed in grid system and selects some of them as the proxy se...
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This paper proposes a novel parallel data transfer mechanism to improve the performance of data transfer in grid environment. It utilizes the servers distributed in grid system and selects some of them as the proxy servers. It introduces the method of how to select the proxy server. Then data are divided into several parts and sent through the selected proxy servers with different physical links. By that, it can effectively improve the performance of data transfer.
Text categorization is the process of assigning documents to a set of previously fixed categories. It is widely used in many data-oriented management applications. Many popular algorithms for text categorization have ...
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ISBN:
(纸本)9780769533162
Text categorization is the process of assigning documents to a set of previously fixed categories. It is widely used in many data-oriented management applications. Many popular algorithms for text categorization have been proposed, such as Naive Bayes, k-Nearest Neighbor (k-NN), Support Vector Machine (SVM). However, those classification approaches do not perform well in every case, for example, SVM can not identify categories of documents correctly when the texts are in cross zones of multi-categories, k-NN cannot effectively solve the problem of overlapped categories borders. In this paper, we propose an approach named as Multi-class SVM-kNN (MSVM-kNN) which is the combination of SVM and k-NN. In the approach, SVM is first used to identify category borders, then k-NN classifies documents among borders. MSVM-kNN can overcome the shortcomings of SVM and k-NN and improve the performance of multi-class text classification. The experimental results show MSVM-kNN performs better than SVM or kNN.
In virtual machine (VM) systems, mandatory access control (MAC) enforcement is possible now. This technique is both stronger and more flexible than traditional VM isolation, even if network communication is controlled...
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In virtual machine (VM) systems, mandatory access control (MAC) enforcement is possible now. This technique is both stronger and more flexible than traditional VM isolation, even if network communication is controlled. Unfortunately all of the VM systems with the MAC enforcement does not consider that the MAC controls may be distorted by covert channels, which constitute an important risk in VM systems. Traditional MAC models have difficulties being enforced to reduce the risk of covert flows in VM systems due to the many constraints and the lack of flexibility. In this paper, we identify access control requirements for managing covert channels in VM systems through a critical analysis of the ways by which classical models constrain the covert information flows and we propose a model called the Prioritized Chinese Wall model (PCW) to reduce the risk of covert flows in VM systems while preserving the flexibility. Furthermore, we enforce the policy in sHype/Xen VM system.
Monitor substation equipment temperature is one of the most important factors for power systems to ensure safe transmission of electricity. Traditional methods for monitoring the substation temperature shows many disa...
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The first step towards the information lifecycle management is to differentiate information by values. This paper presents an evaluation model for information value. The idea of the model is from commodity value disci...
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ISBN:
(纸本)9780769532639
The first step towards the information lifecycle management is to differentiate information by values. This paper presents an evaluation model for information value. The idea of the model is from commodity value discipline in economic area. The output of information value evaluation model is determined by information itself which is like commodity price is determined by use-value in economic area. The output of the model is changed around the real information value and controlled by the relationship between information supply and demand. The output of the model is determined by factors from three aspects that are information itself, information supply, and information demand. When applying the model into traditional information management approaches, such as replication, data migration, and backup, those mechanisms control the output of the model through adjusting the ability of information supply.
There has been significant progress in the development and deployment of peer-to-peer (P2P) live video streaming systems. However, there has been little study on the security aspect in such systems. Our prior experien...
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ISBN:
(纸本)9781424432134
There has been significant progress in the development and deployment of peer-to-peer (P2P) live video streaming systems. However, there has been little study on the security aspect in such systems. Our prior experiences in Anysee exhibit that existing systems are largely vulnerable to intermediate attacks, in which the content pollution is a common attack that can significantly reduce the content availability, and consequently impair the playback quality. This paper carries out a formal analysis of content pollution and discusses its implications in P2P live video streaming systems. Specifically, we establish a probabilistic model to capture the progress of content pollution. We verify the model using a real implementation based on Anysee system; we evaluate the content pollution effect through extensive simulations. We demonstrate that (1) the number of polluted peers can grow exponentially, similar to random scanning worms. This is vital that with 1% polluters, the overall system can be compromised within minutes; (2) the effective bandwidth utilization can be sharply decreased due to the transmission of polluted packets; (3) Augmenting the number of polluters does not imply a faster progress of content pollution, in which the most influential factors are the peer degree and access bandwidth. We further examine several techniques and demonstrate that a hash-based signature scheme can be effective against the content pollution, in particular when being used during the initial phase.
Peers in multiple P2P applications execute overlapped operations with different implementation, like neighbour management, resource publish/lookup, delay investigation, which leads to poor interoperability and unneces...
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Peers in multiple P2P applications execute overlapped operations with different implementation, like neighbour management, resource publish/lookup, delay investigation, which leads to poor interoperability and unnecessary network load. Peers contribute their resources only when they stay in same application. We propose a P2P middleware, called Ripple, to accomplish common functions in a layered architecture. Ripple manages all peers running various applications in a uniform substrate overlay network. The substrate overlay is designed with a hybrid topology. This hybrid topology does not aim at only a particular type of applications, but also enables the flexibility for various applications. Our work is an attempt to address common needs of P2P applications, which may simplify the development and improve the performance of P2P networks, as well as mitigate the sampling stress to physical networks.
As the world of gridcomputing is continuously growing, scalability and complexity of grid systems are in an increasing rate. Moreover, grid systems are dynamic and subject to various changes. Management of such chang...
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As the world of gridcomputing is continuously growing, scalability and complexity of grid systems are in an increasing rate. Moreover, grid systems are dynamic and subject to various changes. Management of such changes is a challenging issue facing grid communities. Namely, how to efficiently maintain grid system to adopt the environment modification, to meet the user demands and to manage the dynamic changes has become a big challenge. Manual- or script based maintenance approaches are tedious, time consuming and complex, in addition to being highly prone to errors. Therefore, state-of-the-art maintenance models are designed to support transparent runtime maintenance, fast and comprehensive respond to environmental changes and requirements, consequently, improve the availability and efficiency of the grid system. This paper focuses on investigating maintenance models and their common characteristics for grid. To this end, this paper surveys several representative grid maintenance model systems developed by various projects worldwide. The contributions of this paper are (i) discussing the motivations of maintenance for grid system, (ii) discussing the issues and the challenges in building maintenance mechanisms for grid system, (iii) reviewing maintenance models and compare their efficiencies for grid system, and (iv) discussing possible new directions.
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