The SOLIS solar telescope collects data at a high rate, resulting in 500 GB of raw data each day. The SOLIS data Handling System (DHS) has been designed to quickly process this data down to 156 GB of reduced data. The...
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ISBN:
(纸本)0819446270
The SOLIS solar telescope collects data at a high rate, resulting in 500 GB of raw data each day. The SOLIS data Handling System (DHS) has been designed to quickly process this data down to 156 GB of reduced data. The DHS design uses pools of distributed reduction processes that are allocated to different observations as needed. A farm of 10 dual-cpu Linux boxes contains the pools of reduction processes. Control is through CORBA and data is stored on a fibre channel storage area network (SAN). Three other Linux boxes are responsible for pulling data from the instruments using SAN-based ringbuffers. Control applications are Java-based while the reduction processes are written in C++. This paper presents the overall design of the SOLIS DHS and provides details on the approach used to control the pooled reduction processes. The various strategies used to manage the high data rates are also covered.
The selected aspects of design methodology of a telemetric system for monitoring civil engineering constructions-using fiber-optic strain sensors-are considered. Particular attention is paid to the design decisions co...
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The selected aspects of design methodology of a telemetric system for monitoring civil engineering constructions-using fiber-optic strain sensors-are considered. Particular attention is paid to the design decisions concerning the choice of a method for sensor calibration and measurand reconstruction, resulting requirements for computing power and their consequence on the distribution of dataprocessing in the considered telemetric system. The results of this study may be applied for designing a specific telemetric system with fiber-optic sensors of strain.
Target tracking using multiple sensors can provide better performance than using a single sensor. One approach to multiple target tracking with multiple sensors is to first perform single sensor tracking and then fuse...
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Target tracking using multiple sensors can provide better performance than using a single sensor. One approach to multiple target tracking with multiple sensors is to first perform single sensor tracking and then fuse the tracks from the different sensors. Two processing architectures for track fusion are presented: sensor to sensor track fusion, and sensor to system track fusion. Technical issues related to the statistical correlation between track estimation errors are discussed. Approaches for associating the tracks and combining the track state estimates of associated tracks that account for this correlation are described and compared by both theoretical analysis and Monte Carlo simulations.
Describes a system for using the World Wide Web to distribute computational tasks to multiple hosts on the Web. A programmer with a computation to distribute registers it with a Web server. An idle host uses this serv...
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Describes a system for using the World Wide Web to distribute computational tasks to multiple hosts on the Web. A programmer with a computation to distribute registers it with a Web server. An idle host uses this server to identify available computations and downloads a Java class to perform the computation - we call this class a distriblet. The paper describes the programs written to carry out the load distribution, the structure of a distriblet class, and our experience in using this system.
The Java programming language supports the concept of downloadable executable content;a key technology in a wide range of emerging applications including collaborative systems, electronic commerce, and Web information...
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The Java programming language supports the concept of downloadable executable content;a key technology in a wide range of emerging applications including collaborative systems, electronic commerce, and Web information services. Java enables the execution of a program, on almost any modem computer regardless of hardware configuration and operating system. Safe-Tcl was proposed as an executable content type of MIME and thus as the standard language for executable contents within e-mail messages. However, the ability to download, integrate, and execute code from a remote computer, provided by both Java and Safe-Tcl, introduces serious security risks since it enables a malicious remote program to obtain unauthorised access to the downloading system's resources. In this paper, the two proposed security models are described in detail and the efficiency and flexibility of current implementations are evaluated in a comparative manner. Finally upcoming extensions are discussed.
Nomadicity is a new challenge for computing and communication technologies. Modern cellular telephone systems extend the usability of portable personal computers enormously. A nomadic user can be given ubiquitous acce...
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Nomadicity is a new challenge for computing and communication technologies. Modern cellular telephone systems extend the usability of portable personal computers enormously. A nomadic user can be given ubiquitous access to remote information stores and computing services. However, the behaviour of wireless links creates severe inconveniences within the traditional data communication paradigm. In this paper we give an overview of the problems related to wireless mobility We also present a new software architecture for mastering the problems and discuss a new paradigm for designing mobile distributed applications. The key idea in the architecture is to place a mediator, a distributed intelligent agent, between the mobile node and the wireline network.
The World Wide Web has experienced explosive growth as a content delivery mechanism, delivering hypertext files and static media content in a standardised way. However, this content has been unable to interact with ot...
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The World Wide Web has experienced explosive growth as a content delivery mechanism, delivering hypertext files and static media content in a standardised way. However, this content has been unable to interact with other content, making the Web a distribution system rather than a distributed system. This is changing, however, as distributed component architectures are being adapted to work with the Web's architecture. This paper tracks the development of the Web as a distributed platform, and highlights the potential to employ an often neglected feature of distributed computing: migration. Argues that all content on the Web, be it static images or distributed components, should be free to migrate according to either the policy of the server, or the content itself. The requirements of such a content migration mechanism are described, and an overview of a new migration mechanism, currently being developed by the authors, is presented.
It is proposed that future work should move on from existing network and system management methodologies to consider enhancing the management methodology for ATM and other networking technologies to meet existing and ...
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It is proposed that future work should move on from existing network and system management methodologies to consider enhancing the management methodology for ATM and other networking technologies to meet existing and future requirements. This paper outlines an area where significant potential for further research exists and proposes a component-based management architecture. The discussion indentifies the technological limitations and architectural drawbacks of current solutions and proposes the extension of existing services and an enhanced management framework to overcome the current restrictions.
This part of ISO/IEC 2382 is intended to facilitate international communication in distributed data processing. It presents, in two languages, terms and definitions of selected concepts relevant to the field of inform...
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标准号:
ISO/IEC 2382-18-1999
This part of ISO/IEC 2382 is intended to facilitate international communication in distributed data processing. It presents, in two languages, terms and definitions of selected concepts relevant to the field of information technology and identifies relationships among the entries. In order to facilitate their translation into other languages, the definitions are drafted so as to avoid, as far as possible, any peculiarity attached to a language. This part of ISO/IEC 2382 defines concepts related to distributed data processing, and specially network elements and components, network topology, network architecture, and network functions and applications.
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