15326279
GCS-MA: A group communication system for mobile agents
Reliable messaging is a key component necessary for mobile agent systems. Current researches focus on reliable one-to-one message delivery to mobile agents. But how to implement a group communication system for mobile agents remains an open issue, which is a powerful block that facilitates the development of fault-tolerant mobile agent systems. In this paper, we propose a group communication system for mobile agents (GCS-MA), which includes totally ordered multicast and membership management functions. We divide a group of mobile agents into several agent clusters, and each agent cluster consists of all mobile agents residing in the same sub-network and is managed by a special module, named coordinator. Then, all coordinators form a ring-based overlay for interchanging messages between clusters. We present a token-based algorithm, an intra-cluster messaging algorithm and an inter-cluster migration algorithm to achieve atomicity and total ordering properties of multicast messages, by building a membership protocol on top of the clustering and failure detection mechanisms. Performance issues of the proposed system have been analysed through simulations. We also describe the application of the proposed system in the context of the service cooperation middleware (SCM) project.
46077798
A Component-Based Analytical Performance Model of IP-Based SAN
In this paper we propose a component-based analytical performance model for IP-based SAN. This model evaluates and analyzes the behavior of IP network, cache, RAID and disks under multiple synchronous I/O workloads by using closed queueing networks. The theoretical results are compared with the results from a real IP-based SAN using a variety of synthetic workloads. These experiments prove that the component-based method is an appropriate way to build performance model for a complex storage system. Using the model, we can find out that the bottleneck of SAN performance is network or storage node under different workloads or applications. We also identify areas for future research in the performance analysis of real IP-based SAN.
17485840
A framework for application server based Web services management
Web services are considered as solution for solving the interoperability problem and the challenge of integration. How to manage Web services more efficiently is a key problem to the applications based on Web services at present. This paper presents a framework for application server based Web services management named FASWSM. The main contribution of FASWSM is Web service adaptation, so that a Web service can be plugged into the application server (AS) as a Web service adapter which enables a Web service to be managed by the application server. Therefore, the Web services management efforts are greatly reduced by leveraging various services provided by the AS. The FASWSM also provides mechanisms for dynamical reconfiguration which improve the extensibility and flexibility of Web services management. The FASWSM has been applied to OnceAS 2.0 application server, and the experiments data show that FASWSM outperforms JAX-RPC in terms of Web service invocation.
38303932
Fuzzy inference based on fuzzy concept lattice
In this paper, a fuzzy inference method based on the notion of fuzzy concept lattice is studied. We first propose a new form of fuzzy concept lattice, and then based on three kinds of known fuzzy concept lattices and our new fuzzy concept lattice, two coherent fuzzy inference methods, the lower approximate fuzzy inference and the upper approximate fuzzy inference, are proposed, and the combined use of the two methods will make the fuzzy inference more precise.
2507502
An Analytical Performance Model of IP-SAN
In this paper we propose a component-based analytical performance model for IP-SAN. We model four key components within IP-SAN individually and they are IP network, cache, RAID and disks. We validate these component models and compose them to give an entire IP-SAN performance model. The entire IP-SAN model analyzes the performance of an IP-SAN configuration under multiple synchronous workloads by using closed queueing network model and under asynchronous workload by using open queueing network model. We also validate the entire IP-SAN performance model against a real IP-SAN system. The theoretical results are compared with the results from a real IP-SAN using a variety of synthetic workloads. These experiments prove that the component-based method is an appropriate way to build performance model for a complex storage system. To our knowledge, this is the first exploration into building analytical performance model for entire IP-SAN system and validating against a real system. We also identify areas for future research in the performance analysis of real IP-SAN.
17469824
Extending OBDD graphs for composite event matching in content-based pub/sub systems
Content-based publish/subscribe offers a convenient abstraction for the information producers and consumers, supporting a large-scale system design and evolution by integrating several distributed independent application systems. Its core problem is how to match events by predicates on the content of events. In this paper, we propose three matching models, extend the simple matching to the multi-semantic matching and introduce the temporal constraint variable. The multi-semantic matching allows using different operations in accordance with different semantics; the temporal constraint variable supports processing the discrete events in the temporal sequence. Then, we extend OBDD graphs into hierarchy coloured OBDD graphs and prove the equivalence of the transformation. At last, based on OBDD graphs the composite matching algorithm is presented and analysed. By experiments, we show the proposed algorithm is efficient.
3137385
Automatic Recognition of Logical Relations for English, Chinese and Japanese in the GLARF Framework
We present GLARF, a framework for representing three linguistic levels and systems for generating this representation. We focus on a logical level, like LFG's F-structure, but compatible with Penn Treebanks. While less finegrained than typical semantic role labeling approaches, our logical structure has several advantages: (1) it includes all words in all sentences, regardless of part of speech or semantic domain; and (2) it is easier to produce accurately. Our systems achieve 90% for English/Japanese News and 74.5% for Chinese News -- these F-scores are nearly the same as those achieved for treebank-based parsing.
28994560
A Transaction-Aware Coordination Protocol for Web Services Composition
With the rapid development of WWW, Web Service is becoming a new application model for decentralized computing based on Internet. However, the tradeoff problem between consistency and resource utilization is the primary obstructer for building a transactional environment for Web Services Compositions. Since a resource may not be acceptable to lock exclusively by an unknown Internet user, we propose a Transaction-Aware Tentative Hold Protocol (taTHP) to perceive the transaction context information and play a more active role in transaction coordination. With the capability of forecasting the will-succeed transactions in a fairly small scope of candidates, taTHP is able to achieve more resource utilization with smaller complaints about the transaction coordination. Finally, a comprehensive comparison is carried out to demonstrate the improvement of the proposed protocol. And it can be concluded from the result that taTHP is provided with better efficiency and satisfactory quality of service.
19005326
A hybrid particle swarm optimization approach with prior crossover differential evolution
Particle swarm optimization (PSO) is population-based heuristic searching algorithm. PSO has excellent ability of global optimization. However, there are some shortcomings of prematurity, low convergence accuracy and speed, similarly to other evolutionary algorithms (EA). To improve its performance, a hybrid particle swarm optimization is proposed in the paper. Firstly, the average position and velocity of particles are incorporated into basic PSO for concerning with the effect of the evolution of the whole swarm. Then a differential evolution (DE) computation, which introduces an extra population for prior crossover, is hybridized with the improved PSO to form a novel optimization algorithm, PSOPDE. The role of prior crossover is to appropriately diversify the population and increase the probability of reaching better solutions. DE component takes into account the stochastic differential variation, and enhances the exploitation in the neighborhoods of current solutions. PSOPDE is implemented on five typical benchmark functions, and compared with six other algorithms. The results indicate that PSOPDE behaves better, and greatly improve the searching efficiency and quality.
17935039
Data manipulation techniques to reduce phase change memory write energy
Due to its great scalability potential, phase change memory has become a topic of great current interest. However, high write energy consumption appears to be one of the biggest challenges to be tackled before phase change memory can be adopted as a mainstream memory technology. This paper presents architecture level technique to reduce phase change memory write energy consumption through data manipulations. Motivated by the fact that phase change memory read incurs much less energy than write and write of different value to a phase change memory cell incurs largely different energy, we present two memory write data manipulation techniques that can effectively reduce the overall memory write energy consumption. Their effectiveness has been demonstrated based on mathematical analysis and computer system simulation using phase change memory as the main memory in the computer memory hierarchy. Significant energy savings with up to more than 60% have been shown over a wide range of computer system benchmarks.
1951107
CCSMOMS:A Composite Communication Scheme for Mobile Object Management System
In this paper, we discuss the design and implementation of a mobile object management system that makes use of the existing GSM (Global System for Mobile Communication) networks and it's extension-GPRS (general packet radio service) for data communication. We use a novel composite communication scheme (CCS), which uses SMS (short message service) and GPRS to achieve reliable and economical communication between mobile objects and the control center. We also use unified data management (UDM) for control center management, which significantly reduces the cost of maintaining separate data centers. We have deployed our services in two medium-sized cities with real users. The cost evaluation shows the high performance, usability and cost-effectiveness of this service in real production environment