9730668
Broadening the Semantic Coverage of Agent Communicative Acts
Communicative acts-based ACLs specify domain-independent information about communication and relegate domain-dependent information to an unspecified content language. This is reasonable, but the ACLs cover only a small fraction of the domain-independent information possible. As a key element of modern ACLs, the set of communicative acts needs to be as complete as possible to allow agents to communicate the widest range of information with agreed-upon semantics. This paper describes a new approach to broaden the semantic coverage of agent communicative acts. It provides agents with the ability to express more of the semantics of human languages and yields a more powerful ACL. We first describe the main meaning categories and semantics for an ACL, which we derive from prior work on speech-act classifications. Next, we prove the resultant semantic coverage. Finally, we present some example applications, which demonstrate that the approach can combine the benefits of the FIPA ACL with Ballmer and Brennenstuhl’s speech act classification, resulting in a more expressive and efficient ACL.
18773100
An Approach to Broaden the Semantic Coverage of ACL Speech Acts
Current speech-act based ACLs specify domain-independent information about communication and relegate domain-dependent information to an unspecified content language. This is reasonable, but the ACLs cover only a small fraction of the domain-independent information possible. As a key element of modern ACLs, the set of communicative acts needs to be as complete as possible to enable agents to communicate the widest range of information with agreed-upon semantics. This paper describes a new approach to broaden the semantic coverage of ACL speech acts. It provides agents with the ability to express more of the possible meanings in human languages and yields a more powerful ACL. Specifically, we first compare Austin's and Searle's classifications, and Ballmer and Brennenstuhl's comprehensive classification of speech acts. The main meaning categories and their semantics are given next. Finally, a multifaceted evaluation of our approach is presented, which points out that the approach potentially can combine the benefits of the FIPA ACL with Ballmer and Brennenstuhl's speech act classification, resulting in a more expressive ACL.
40224327
Performance and cost effectiveness of a cluster of workstations and MD-GRAPE 2 for MD simulations
Molecular dynamics (MD) simulations are performed on systems of various sizes up to 32 million atoms. Performance is compared between an MD-GRAPE 2 board, specialized hardware optimized for MD, and a general purpose cluster computer utilizing varied numbers of processors for both short- and long-range potentials. While it is possible to outperform a single MD-GRAPE 2 board with a sufficient number of processors, tests verses a local cluster and comparison of original purchase price show the MD-GRAPE 2 board is often cost-effective. Potential-specific considerations are discussed.
2360073
Performance properties of combined heterogeneous networks
We study the performance properties of combined multiple heterogeneous networks. We consider two nodes: node1 and node2, with multiple heterogeneous physical networks connecting them. Each network has some properties such as bandwidth, latency, and packet loss ratio. We develop an analytical model to find the peak performance, or upper bound, of combined networks for the transfer of a message of a given size in parallel. The model is based on the existence of an optimal load balancing mechanism for parallel transfer that fully utilizes the existing networks. The paper provides a framework to find the peak performance parameters of message transfer over combined heterogenous networks as well as to measure the actual utilization and efficiency of parallel message transfer implementations.
8918525
An efficient, low-cost inconsistency detection framework for data and service sharing in an Internet-scale system
In this paper, we argue that a broad range of Internet-scale distributed applications can benefit from an underlying low-cost consistency detection framework that is an alternative to inconsistency avoidance and can detect inconsistency among nodes sharing data or services in a timely manner. This paper first presents an overview of the inconsistency detection framework. Then, it discusses the detailed design of the two-layer inconsistency detection module, the core component of this framework, which can detect inconsistency among nodes in a timely manner. The proposed two-layer inconsistency detection module is evaluated both analytically and via simulations, which shows that this module can significantly reduce the time to detect inconsistency among nodes without adding much maintenance cost. Finally, this paper outlines the possible mechanisms to discern the application semantics and to resolve the detected inconsistencies
1310060
Multiagent Coalition Formation for Computer-Supported Cooperative Learning
In this paper, we describe a computer-supported cooperative learning system in education and the results of its deployment. The system, called I-MINDS, consists of a set of teacher agents, group agents, and student agents. While the agents possess individual intelligent capabilities, the novel invention of I-MINDS lies in multiagent intelligence and coalition formation. I-MINDS supports student participation and collaboration and helps the instructor manage large, distance classrooms. Specifically, it uses a Vickrey auction-based and learning-enabled algorithm called VALCAM to form student groups in a structured cooperative learning setting. We have deployed I-MINDS in an introductory computer science course (CS1) and conducted experiments in the Spring and Fall semesters of 2005 to study how I-MINOS-supported collaboration fares against traditional, face-to-face collaboration. Results showed that students using I-MINDS performed (and outperformed in some aspects) as well as students in traditional settings.
23742969
High-performance message striping over reliable transport protocols
This paper introduces a high-performance middleware-level message striping approach to increase communication bandwidth for data transfer in heterogeneous clusters equipped with multiple networks. In this scheme, concurrency is used for the striping process. The proposed striping approach is designed to work at the middleware-level, between the distributed applications and the reliable transport protocols such as TCP. The middleware-level striping approach provides flexible, scalable, and hardware-, network-, and operating systems-independent communication bandwidth solution. In addition, techniques to enhance the performance of this approach over multiple networks are introduced. The proposed techniques, which minimize synchronization contention and eliminate the striping sequence header, rely on the features of a reliable transport protocol such as TCP to reduce some of the concurrent striping overhead. The techniques have been implemented and evaluated on a real cluster with multiple networks and the results show significant performance gains for data transfer over existing approaches.