With the advent of Grid and application technologies, scientists and engineers are building more and more complex applications to manage and process large data sets, and execute scientific experiments on distributed r...
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Distributed denial of service (DDoS) attacks on the Internet have become an immediate problem. As DDoS streams do not have common characteristics, currently available intrusion detection systems (IDS) can not detect t...
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ISBN:
(纸本)9728865252
Distributed denial of service (DDoS) attacks on the Internet have become an immediate problem. As DDoS streams do not have common characteristics, currently available intrusion detection systems (IDS) can not detect them accurately. As a result, defend DDoS attacks based on current available IDS will dramatically affect legitimate traffic. In this paper, we propose a distributed approach to defend against distributed denial of service attacks by coordinating across the Internet. Unlike traditional IDS, we detect and stop DDoS attacks within the intermediate network. In the proposed approach, DDoS defense systems are deployed in the network to detect DDoS attacks independently. A gossip based communication mechanism is used to exchange information about network attacks between these independent detection nodes to aggregate information about the overall network attacks observed. Using the aggregated information, the individual defense nodes have approximate information about global network attacks and can stop them more effectively and accurately. To provide reliable, rapid and widespread dissemination of attack information, the system is built as a peer to peer overlay network on top of the internet.
This paper identifies challenges in managing resources in a Grid computing environment and proposes computational economy as a metaphor for effective management of resources and application scheduling. It identifies d...
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This paper describes TRAP/C++, a software tool that enables new adaptable behavior to be added to existing C++ programs in a transparent fashion. In previous investigations, we used an aspectoriented approach to manua...
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ISBN:
(纸本)1595930396
This paper describes TRAP/C++, a software tool that enables new adaptable behavior to be added to existing C++ programs in a transparent fashion. In previous investigations, we used an aspectoriented approach to manually define aspects for adaptation infrastructure, which were woven into the original application code at compile time. In follow-on work, we developed TRAP, a transparent shaping technique for automatically generating adaptation aspects, where TRAP/J is a specific instantiation of TRAP. This paper presents our work into building TRAP/C++, which was intended to be a port of TRAP/J into C++. Designing TRAP/C++ required us to overcome two major hurdles: lack of reflection in C++ and the incompatibility between the management of objects in C++ and the aspect weaving technique used in TRAP/J. We used generative programming methods to produce two tools, TrapGen and TrapCC, that work together to produce the desired TRAP/C++ functionality. Details of the TRAP/C++ architecture and operation are presented, which we illustrate with a description of a case study that adds dynamic auditing capabilities to an existing distributed C++ application. Copyright 2005 ACM.
Embedded systems are pervasive and frequently used for critical systems with time-dependent functionality. Dwyer et al. have developed qualitative specification patterns to facilitate the specification of critical pro...
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ISBN:
(纸本)9781581139631
Embedded systems are pervasive and frequently used for critical systems with time-dependent functionality. Dwyer et al. have developed qualitative specification patterns to facilitate the specification of critical properties, such as those that must be satisfied by embedded systems. Thus far, no analogous repository has been compiled for real-time specification patterns. This paper makes two main contributions: First, based on an analysis of timing-based requirements of several industrial embedded system applications, we created real-time specification patterns in terms of three commonly used real-time temporal logics. Second, as a means to further facilitate the understanding of the meaning of a specification, we offer a structured English grammar that includes support for real-time properties. We illustrate the use of the real-time specification patterns in the context of property specifications of a real-world automotive embedded system. Copyright 2005 ACM.
Recomposable software enables a system to change its structure and behavior during execution, in response to a dynamic execution environment. This paper proposes an approach to ensure that such adaptations are safe wi...
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Internet networked virtual environments, such as VRML-based environments, should provide a satisfactory immersive experience to users. However, the time needed to download them and display them in the user platform, a...
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ISBN:
(纸本)0946881324
Internet networked virtual environments, such as VRML-based environments, should provide a satisfactory immersive experience to users. However, the time needed to download them and display them in the user platform, as well as the time delays in effectively starting an interaction, may adversely influence the overall user satisfaction. This article shows the results of a series of usability tests oriented towards improving Internet networked virtual environments construction by analysing the influence of time delays and other problems in the users' perception of virtual environments.
Persistent use of an information technology is necessary if it is to enhance productivity and user satisfaction. In this paper, we examine the process of appropriation of an application software over time, to gain a d...
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Open-source and industrial softwaresystems often lack up-to-date documents on the implementation of user-observable functionalities. This lack of documents is particularly hindering for large systems. Moreover, as wi...
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ISBN:
(纸本)1595932437
Open-source and industrial softwaresystems often lack up-to-date documents on the implementation of user-observable functionalities. This lack of documents is particularly hindering for large systems. Moreover, as with any other software artifacts, user-observable functionalities evolve through software evolution activities. Evolution activities sometimes have undesired and unexpected side-effects on other functionalities, causing these to fail or to malfunction. In this position paper, we promote the idea that a traceability link between user-observable functionalities and constituents of a software architecture (classes, methods. . . implementing the functionalities) is essential to reduce the software evolution effort. We outline an approach to recover and to study the evolution of features -subsets of the constituents of a software architecture - responsible for a functionality. Copyright 2005 ACM.
The need for mass-produced inexpensive wireless devices operating under strict energy constraints poses new challenges in the system design methodology. This paper presents a methodology for designing wireless nodes i...
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The need for mass-produced inexpensive wireless devices operating under strict energy constraints poses new challenges in the system design methodology. This paper presents a methodology for designing wireless nodes in which a low cost, reliable antenna is realized by printed circuit traces. We show how to combine the analysis from 2.5D and 3D EM simulators with the PCB design tools to create predictable nodes with printed antennas that meet stringent power and data transmission range goals. The presented approach is applied to the design of a IEEE802.15.4 wireless node deployed in several indoor environments. Copyright 2005 ACM.
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