This paper describes the design and implementation of extensions to the Regis distributed programming platform which add protocol stacks to communication endpoints. Although our initial goal was to extend Regis to sup...
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This paper describes the design and implementation of extensions to the Regis distributed programming platform which add protocol stacks to communication endpoints. Although our initial goal was to extend Regis to support multiple transport protocols, groupcast and multimedia communication, the dynamic nature of the protocol framework allowed new approaches to the design of communication protocol software. Transient protocol layers provide support for binding establishment and connection management in a manner which is largely transparent to the user of the endpoint. The paper describes this approach through examples and shows how it leads to greater efficiency and a greater degree of code reuse.
As distributedsystems grow larger and more complex, the problem of managing them becomes more serious, and automated assistance becomes essential. Automated management services need to become a standard part of distr...
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As distributedsystems grow larger and more complex, the problem of managing them becomes more serious, and automated assistance becomes essential. Automated management services need to become a standard part of distributedsystems, but in order for them to be of any value they must be general enough to adapt to the needs of any organization, without sacrificing practical usability. That challenge is partially addressed in this paper with a proposal for automated configuration management based upon descriptions of configuration states. The proposed model is very general, yet the language and algorithms that are introduced are designed to be very practical. Experimental application of this approach to a real-life configuration problem is presented, with comparison to the existing solution that is in production use.
Quiescent current monitoring is considered as an interesting and efficient technique for mixed-signal testing, where fault detection of analog parts requires the precise measure of the Iddq. This paper presents a very...
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Quiescent current monitoring is considered as an interesting and efficient technique for mixed-signal testing, where fault detection of analog parts requires the precise measure of the Iddq. This paper presents a very simple current sensor for on-chip current monitoring giving an accurate analog output proportional to the quiescent current. The proposed circuit is based on a second generation current conveyor. Experimental results show the functionality of the proposed configuration and its linear output characteristic.
This paper presents the architecture and base services of Sampa, a System for Availability Management of Process-based Applications. The system has been designed to support the management of fault-tolerant DCE-based d...
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This paper presents the architecture and base services of Sampa, a System for Availability Management of Process-based Applications. The system has been designed to support the management of fault-tolerant DCE-based distributed programs according to user-provided and application-specific availability specifications. Sampa is supposed to detect and automatically react to faults such as node crashes, network partitions, process crashes and hang-ups. In this paper we focus on the design of its base services - the monitoring, reliable group communication and checkpointing facilities - and show how they can be used for managing a generic replicated service.
With the increasing demand for long running and highly available distributed services, interest in systems which can undergo dynamic reconfiguration has risen. However for dynamic change to yield valid systems, change...
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With the increasing demand for long running and highly available distributed services, interest in systems which can undergo dynamic reconfiguration has risen. However for dynamic change to yield valid systems, change actions must be carried out such that the consistency of the software modules making up the system is not breached. This can be ensured if the subset of the system which is to undergo change is in a state amenable to reconfiguration. This paper presents an algorithm which imposes a safe state over the part of the system undergoing change. The algorithm suits a particular class of transactional systems and places special emphasis on minimising the interference to the rest of the system and reducing the programmer contribution necessary for achieving this safe state.
This paper is concerned with the identification of corresponding points in curves related together, as time series, or in epipolar lines of stereo images. The properties of the corresponding points are defined by the ...
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ISBN:
(纸本)7505338900
This paper is concerned with the identification of corresponding points in curves related together, as time series, or in epipolar lines of stereo images. The properties of the corresponding points are defined by the near neighbourhood but also further points which are related to the corresponding point. Filtering with special non-linearities is applied to suppress non-relevant information and to find interrelations. For this the curves are represented by non-linear stochastic differential equations. The properties of the curves are obtained by the estimation of the expectation values of these stochastic equations and represented by different fuzzy measures. The corresponding points are determined by fusion of information obtained from different properties related to a special corresponding point with the help of fuzzy integrals. Using filtering and fuzzy integration of properties, feature and intensity based methods are combined.
This paper describes a family of design patterns that enhance the flexibility and extensibility of communication software by permitting network services to evolve independently of the strategies used to passively init...
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This paper describes a family of design patterns that enhance the flexibility and extensibility of communication software by permitting network services to evolve independently of the strategies used to passively initialize the services. The paper makes three contributions to the study and development of configurable distributedsystems. First, it identifies five orthogonal dimensions of passive service initialization: service advertisement, endpoint listening, service handler creation, passive connection establishment, and service handler activation. Second, the paper illustrates how a family of design patterns have been used to build a communication software framework that supports flexible configuration of different strategies for each of these five dimensions. Third, the paper demonstrates how design patterns and frameworks are being used successfully to develop configurable large-scale production distributedsystems.
＜正＞This paper provides a new approach to spatial spectral estimation,called eigenvalue shift superresolution Algorithm（ESSA）.This method avoids the inverse covariance *** can be applied to the processing of data ...
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ISBN:
(纸本)0780329120
＜正＞This paper provides a new approach to spatial spectral estimation,called eigenvalue shift superresolution Algorithm（ESSA）.This method avoids the inverse covariance *** can be applied to the processing of data received by spatially distributed arrays of sensors.
This paper exhibits the use of existing software bus technology in interconnecting Virtual-Reality Environment (VE) software. Interoperability and application construction from heterogeneous modules are well-explored ...
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ISBN:
(纸本)0818673958
This paper exhibits the use of existing software bus technology in interconnecting Virtual-Reality Environment (VE) software. Interoperability and application construction from heterogeneous modules are well-explored topics of distributedsystems. A joint project using the Polylith software bus from the University of Maryland and VE software from the UNC graphics lab has shown the utility of composing existing applications as opposed to making extensive individual modifications. This paper claims only a unique application of these methods to a new client area. Multi-user VE walkthroughs (software navigators) are an exciting new area in graphics software but we see that with the rapid development of graphics technology, next-generation applications (including multi-user systems) are commonly redesigned from the ground up. Here we see an excellent opportunity to examine module reusability, with proven software, in a new application area. As well, we hope our experiments will likely lead to conclusions about VE programming abstractions and produce development methods for making easily interoperable next-generation VE applications.
Data handles and virtual connections are presented as a solution to the problem of supporting application-driven reconfiguration without sacrificing the separation of communication and computation. The solution suppor...
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Data handles and virtual connections are presented as a solution to the problem of supporting application-driven reconfiguration without sacrificing the separation of communication and computation. The solution supports anonymous reconfiguration, meaning that the module performing the reconfiguration and the modules affected by the reconfiguration need not be aware of each other's presence in the system. The solution allows modules to reconfigure the system within the limits of a specified communication structure while retaining support for dynamic end-user reconfiguration. The work is presented in the context of I/O abstraction, a programming model that defines the communication structure of a distributed system in terms of connections among narrow data interfaces of encapsulated modules. I/O abstraction supports dynamic end-user reconfiguration of distributed applications by separating the communication structure from the module definitions.
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