distributed real-time applications require flexible and dynamic scheduling mechanisms to provide timeliness guarantees to application objects. In this paper we present a new scheduling algorithm that exploits the task...
详细信息
Recent work in opening up distributed object systems to make them suitable for applications needing quality of service control has had the side effect of increasing the complexity in setting up, configuring, and initi...
详细信息
A model for predicting relative performance in distributed shared memory systems is presented. The model is intended for use with systems that feature adaptive consistency schemes. Based on estimated read/write access...
详细信息
A model for predicting relative performance in distributed shared memory systems is presented. The model is intended for use with systems that feature adaptive consistency schemes. Based on estimated read/write access patterns, the model determines the average steady-state communication costs in the system, which serve as a performance indicator. The model is applied to data items which may be either compact data objects or objects consisting of smaller data elements. It is shown that the best results are attained when protocol selection is done at the level of data elements.
This paper considers the reliability of software distributed Shared Memory systems where the unit of sharing is a persistent read-write object. We present an extended coherence protocol for causal consistency model, w...
详细信息
ISBN:
(纸本)0769519199
This paper considers the reliability of software distributed Shared Memory systems where the unit of sharing is a persistent read-write object. We present an extended coherence protocol for causal consistency model, which integrates replication management with independent checkpointing. It uses a novel coordinated burst checkpoint operation in order to replicate consistent checkpoints of shared objects in local memory of distinct system nodes. No special reliable hardware devices are required. The protocol offers high availability of shared objects with limited overhead and ensures fast recovery in case of multiple node failures. In case of the network partitioning all the processes in a majority partition of the system can continuously access all the objects.
Parallelizing dynamic scientific applications involves solving the dynamic load balancing problem. The balancing should take the communication requirements of the application into account. Especially in the field of c...
详细信息
ISBN:
(纸本)1581130104
Parallelizing dynamic scientific applications involves solving the dynamic load balancing problem. The balancing should take the communication requirements of the application into account. Especially in the field of computer graphics many problems are dealing with objects in k-dimensional space with very special communication patterns. We describe a load balancing strategy based on a geometric clustering of objects with provable good performance, that is well suited to applications with interdependencies between neighbouring objects or between objects that have al least one coordinate in common.
We analyse the performance and dependability of protocols which implement 'sequence consistency' in distributed replicated systems. Sites send messages to each other from time to time, passing information abou...
详细信息
We analyse the performance and dependability of protocols which implement 'sequence consistency' in distributed replicated systems. Sites send messages to each other from time to time, passing information about the update requests that have been received. The recipient of a message is chosen according to some probability distribution which may depend on the sender. The random variables of main interest are (a) the interval between receiving an update request and being able to execute it on the original site, subject to the consistency requirement, and (b) the time it takes to bring all sites to a consistent state after the arrival of an update. (C) 1999 Elsevier Science B.V. All rights reserved.
In this paper we consider the distributed resource allocation problem, where the individual cost of each agent attempts to minimize when both the total resource and the capacity of local agents are limit. This problem...
详细信息
ISBN:
(纸本)9781728112985
In this paper we consider the distributed resource allocation problem, where the individual cost of each agent attempts to minimize when both the total resource and the capacity of local agents are limit. This problem is encountered in many practical applications such as demand response, cloud computing systems and economic dispatch of power systems. This kind of problem can be expressed as an optimization problem under constraints. Our goal is to obtain the optimal resource allocation under limited conditions and the global objective function is a sum of all local agents individual cost function. By combining with the distributed primal-dual method, we design a distributed optimization algorithm with a constant step-size. When the cost function of each agent is convex and smooth, we prove that our method can converge to the optimal solution. Finally, we apply the algorithm to the problem of the economic dispatch in power systems and get the optimal resource allocation, which verifies the effectiveness of the algorithm.
Web Services lack the possibility to exchange first-class objects as parameters and results. In current SOA practices, one has to give up years of experience in object-oriented programming, and return to procedural pr...
详细信息
ISBN:
(纸本)9781424442386
Web Services lack the possibility to exchange first-class objects as parameters and results. In current SOA practices, one has to give up years of experience in object-oriented programming, and return to procedural programming, passing as parameters XML data rather than objects. We propose to tackle this problem with our WS-object model which, by transmitting methods in XQuery, as well as data in XML, strives to combine Web Service calls with the power of object-oriented programming. Our concept reinterprets the basics of objects, state and behavior, within the XML world and is based on the use of interfaces and their implementation by classes generated at run-time to convert WS-objects into native language objects that can then be used by server- and client-side programs. WS-objects simplify decoupling, enhance the confidentiality of data and make Web Services more stable and resistant to changes. This paper introduces the WS-object concept and illustrates it with a first implementation in Java.
This paper is concerned with the distributed finite-time attitude tracking control problem for multiple uncertain rigid spacecraft in the presence of unavailable angular velocity under directed graph. First, a finite-...
详细信息
ISBN:
(纸本)9781728112985
This paper is concerned with the distributed finite-time attitude tracking control problem for multiple uncertain rigid spacecraft in the presence of unavailable angular velocity under directed graph. First, a finite-time neuro-adaptive observer is proposed for each follower to estimate its own unavailable angular velocity. Then based on adding a power integrator technique, a distributed finite-time control scheme with only attitude measurements is developed. A rigorous theoretical proof shows that the finite-time stability of the overall closed-loop system is ensured. It is seen that the velocity-free control scheme is distributed and model-independent, resulting in an effective and low-cost strategy for spacecraft applications. A simulation with multiple spacecraft is given to verify the effectiveness of the proposed control scheme.
A survey of modern information technologies of distributed computing for elaboration of netcentricity applications, for example, software and architecture of network computing is carried out. The existing standards fo...
详细信息
ISBN:
(纸本)0769524974
A survey of modern information technologies of distributed computing for elaboration of netcentricity applications, for example, software and architecture of network computing is carried out. The existing standards for distributedobjects, transactions processing and catalogues services are considered and analyzed.
暂无评论