17,732 research outputs found
Natural Language Dialogue Service for Appointment Scheduling Agents
Appointment scheduling is a problem faced daily by many individuals and
organizations. Cooperating agent systems have been developed to partially
automate this task. In order to extend the circle of participants as far as
possible we advocate the use of natural language transmitted by e-mail. We
describe COSMA, a fully implemented German language server for existing
appointment scheduling agent systems. COSMA can cope with multiple dialogues in
parallel, and accounts for differences in dialogue behaviour between human and
machine agents. NL coverage of the sublanguage is achieved through both
corpus-based grammar development and the use of message extraction techniques.Comment: 8 or 9 pages, LaTeX; uses aclap.sty, epsf.te
An occam Style Communications System for UNIX Networks
This document describes the design of a communications system which provides occam style communications primitives under a Unix environment, using TCP/IP protocols, and any number of other protocols deemed suitable as underlying transport layers. The system will integrate with a low overhead scheduler/kernel without incurring significant costs to the execution of processes within the run time environment. A survey of relevant occam and occam3 features and related research is followed by a look at the Unix and TCP/IP facilities which determine our working constraints, and a description of the T9000 transputer's Virtual Channel Processor, which was instrumental in our formulation. Drawing from the information presented here, a design for the communications system is subsequently proposed. Finally, a preliminary investigation of methods for lightweight access control to shared resources in an environment which does not provide support for critical sections, semaphores, or busy waiting, is made. This is presented with relevance to mutual exclusion problems which arise within the proposed design. Future directions for the evolution of this project are discussed in conclusion
The design and implementation of a multimedia storage server tosupport video-on-demand applications
In this paper we present the design and implementation of a client/server based multimedia architecture for supporting video-on-demand applications. We describe in detail the software architecture of the implementation along with the adopted buffering mechanism. The proposed multithreaded architecture obtains, on one hand, a high degree of parallelism at the server side, allowing both the disk controller and the network card controller work in parallel. On the other hand; at the client side, it achieves the synchronized playback of the video stream at its precise rate, decoupling this process from the reception of data through the network. Additionally, we have derived, under an engineering perspective, some services that a real-time operating system should offer to satisfy the requirements found in video-on-demand applications.This research has been supported by the Regional Research Plan of the Autonomus Community of Madrid under an F.P.I. research grant.Publicad
GraphMP: An Efficient Semi-External-Memory Big Graph Processing System on a Single Machine
Recent studies showed that single-machine graph processing systems can be as
highly competitive as cluster-based approaches on large-scale problems. While
several out-of-core graph processing systems and computation models have been
proposed, the high disk I/O overhead could significantly reduce performance in
many practical cases. In this paper, we propose GraphMP to tackle big graph
analytics on a single machine. GraphMP achieves low disk I/O overhead with
three techniques. First, we design a vertex-centric sliding window (VSW)
computation model to avoid reading and writing vertices on disk. Second, we
propose a selective scheduling method to skip loading and processing
unnecessary edge shards on disk. Third, we use a compressed edge cache
mechanism to fully utilize the available memory of a machine to reduce the
amount of disk accesses for edges. Extensive evaluations have shown that
GraphMP could outperform state-of-the-art systems such as GraphChi, X-Stream
and GridGraph by 31.6x, 54.5x and 23.1x respectively, when running popular
graph applications on a billion-vertex graph
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