The most important concept of a market is price – the terms on which the trading objects (products or services) are exchanged. In an ideal market, the price is a reflection of the current state of the market, and the...
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ISBN:
(纸本)9781424432806
The most important concept of a market is price – the terms on which the trading objects (products or services) are exchanged. In an ideal market, the price is a reflection of the current state of the market, and therefore it should be dynamic. From the seller perspective, using an effective dynamic pricing strategy can make a difference between making a profit or loss in a makret. In a grid marketplace, the strategy is even more important given it is very dynamic and volatile nature. In this paper, we describe and review three different pricing strategies for the grid market: Demand-Response, Revenue-Response and Price-Maximizing strategy, and analyze their behavior in different market conditions using simulation approach. Our results show that two of the strategies are able to generate high revenue in various market conditions.
In the existing data fetching algorithms for P2P streaming systems, the peers usually fetch data independently, leading to huge inter-AS traffic (AS: autonomous system). This paper proposes CoFetch, a collaborative fe...
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In the existing data fetching algorithms for P2P streaming systems, the peers usually fetch data independently, leading to huge inter-AS traffic (AS: autonomous system). This paper proposes CoFetch, a collaborative fetching algorithm for P2P live streaming systems to decrease inter-AS traffic. In CoFetch, to avoid that all peers fetch the same data from inter-AS connection, instead of aggressively fetching data depending on the peers' own desires, the peers divide requests into multiple steps. In each step, peers mainly and locally share data fetched in previous steps by other collaborating peers and request subset data from inter-AS connections. The analytical results show that, inter-AS traffic in CoFetch is independent of the number of peers in AS but the number of collaborating peers in AS. Furthermore, in each overlay, when we limit the number of collaborating peers in one AS from 5 to 20, the inter-AS traffic is about 1.7-3 times of the streaming rate, regardless of the number of peers.
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 gridsystem 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 gridsystem 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.
This article consists of a collection of slides from the author's conference presentation. It is concluded that unrealistic targets are endemic to a highly visible project managed by executives disconnected from t...
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This article consists of a collection of slides from the author's conference presentation. It is concluded that unrealistic targets are endemic to a highly visible project managed by executives disconnected from the engineers doing the real work.
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.
Automated trust negotiation (ATN) is a new means to establish trust relationship through the mutual exchange of access control policy and credentials in the open and distributed environments. In ATN, access control po...
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Automated trust negotiation (ATN) is a new means to establish trust relationship through the mutual exchange of access control policy and credentials in the open and distributed environments. In ATN, access control policy plays a key role in protecting resources from unauthorized access. In practice, a policy may contain sensitive information, and its disclosure may cause damages. In order to protect the sensitive policy or its content, the policy is usually designed complex. Even worse, the policy may be self contradictory, which would lead the negotiation to fail. To solve such a problem, a new approach for checking policy consistency is proposed in the paper. In the approach, we analyze why the policy inconsistency happens and specify how to avoid it by simplifying a compound policy. Meanwhile, the approach is proved useful to hide policy by presenting some useful theorems to generate minimal policy set and credential set.
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.
With the development of virtualization technology, it¿s desirable to deploy virtual machines to high performance clusters used for data centers. VNIX, developed in servicescomputingtechnology and systemlab, tr...
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With the development of virtualization technology, it¿s desirable to deploy virtual machines to high performance clusters used for data centers. VNIX, developed in servicescomputingtechnology and systemlab, tries to help cluster administrators to manage a large number of virtual machines (VMs) distributed on clusters. To reduce the complexity of virtualization management, VNIX provides a whole-set of tools for monitoring, deploying, controlling, and configuring virtual machines on clusters. In addition to those basic management functions, VNIX also offers a number of specialized tools for clustering VMs. Due to the complex dynamic environment in clusters, it¿s challenging to design such tools. In this paper, we present the design of VNIX, and we describe several use cases of managing VMs in clusters with VNIX. Such use cases illustrate various ways of using VNIX to simplify the management work and to improve resource utilization.
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