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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

AN INTELLIGENT MANAGER FOR A DISTRIBUTED TELEMETRY SYSTEM

Rasmussen, Arthur N. 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / A number of efforts at NASA's Johnson Space Center are exploring ways of improving operational efficiency and effectiveness of telemetry data distribution. An important component of this is the Real-Time Data System project in the Shuttle Mission Control Center. This project's telemetry system is based on a network of engineering workstations that acquire, distribute, analyze, and display the data. Telemetry data is acquired and partially processed through a commercial programmable telemetry processor. The data is then transferred into workstations where the remaining decommutation, conversion and calibration steps are performed. The results are sent over the network to applications operating within end user workstations. This complex distributed environment is managed by PILOT, an intelligent system that monitors data flow and process integrity with the goal of providing a very high level of availability requiring minimal human involvement. PILOT is a rule-based expert system that oversees the operation of the system. It interacts with agents that operate in the local environment of each workstation and advises the local agents of system status and configuration. This enables each local agent to manage its local environment and provides a resource to which it can come with issues that need a global view for resolution. PILOT is implemented using a commercially available real-time expert system shell and operates in a heterogeneous set of hardware platforms.
2

Synchronized Data Transportation for Distributed Acquirement System Through Direct Ethernet Connection and TDM

Wan, Zhongjie, Qi, Shengyuan, Song, Jian, Wang, Haijiao 10 1900 (has links)
ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / To use Ethernet is the most convenient way to set up a transportation network for a telemetry data acquirement system. However, due to its CSMA/CD (Carrier Sense Multiple Access and Collision Detection) mechanics, Ethernet cannot transport data synchronously. This paper analyzed important features of transportation in a distributed data acquirement system, and presents a resolve for synchronously transporting data in a distributed data acquirement system by using direct Ethernet connection and TDM (time division multiplexing) technique.
3

A Distributed Range Query Framework for Internet of Things

Zhang, Congcong January 2014 (has links)
With the rapid development of information technology, applications referring to the Internet of things are booming. Applications that gather information from sensors and affect the context environment with actuators can provide customized and intelligent behaviour to users. These applications have become widely used nowadays in daily life and have initiated the multi-dimensional range query demand referring to the Internet of things. As the data information is fully distributed and the devices like sensors, mobile phones, etc., has limited resources and finite energy, supporting efficient range query is a tough challenge. In this paper, we have proposed a distributed range query framework for Internet of things. In order to save energy costs and reduce the network traffic, we suggest a reporting data range mechanism in the sensing peers, which choose to report a data range and report again only when the peer senses an abnormal data instead of the common moving data method. In addition, we selected some strong peers to be used as the super peers to create a data index by collecting the reporting data range, which will be used for performing range queries. The study has shown that our proposal framework could reduce resource costs in the less strong peers like sensors and mobile phones, and reduce network traffic among all the peers within the network, as well as support a range query function. According the evaluation results, the reporting data range method could greatly reduce the data migration times and save energy costs, and the data index could significantly reduce accessing unnecessary peers and diminish the network traffic.
4

A REPLACEMENT OF ETHERNET SWICTH FOR NETWORKED TELEMETRY SYSTEM

Song, Jian, Zhu, Ximing 11 1900 (has links)
Ethernet is a common practice to reconstruct a networked telemetry system. However, Ethernet switch cannot best meet the requirement of data transportation in a telemetry system because of its asynchronous mode and the uncertainty of latency time. In addition, the temporal order of the telemetry data will be disrupted when using an Ethernet switch. A device similar to Ethernet switch is presented in this paper, which can transport data synchronously without losing the original temporal order of the telemetry data. Meantime, a special condition is arranged by the device that the timing signal could be transmit from the device to the receiver in a certain delay time, so a timing mechanism derived from IEEE 1588 PTP protocol could be adopted for high accuracy of timing and synchronous sampling control.
5

Delivery of Very High Bandwidth with ATM Switches and SONET

Gossage, Steven A. 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / To deliver high bandwidth, a ubiquitous inter-/intra-building cable plant consisting of single mode and multimode fiber as well as twisted pair copper is required. The selection of the "glue" to transport and interconnect distributed LANs with central facility resources over a pervasive cable plant is the focus of this paper. A description of the traditional problems that must be overcome to provide very high bandwidth beyond the narrow confines of a computer center is given. The applicability of Asynchronous Transfer Mode (ATM) switching (interconnection) and Synchronous Optical NETwork (SONET) (transport) for high bandwidth delivery is described using the environment and requirements of Sandia National Laboratories. Other methods for distributing high data rates are compared and contrasted. Sandia is implementing a standards based foundation utilizing a pervasive single mode fiber cable plant, SONET transport, and ATM switching to meet the goals of gigabit networking.
6

MICROMINIATURE DISTRIBUTED DATA ACQUISITION SYSTEM

PENHARLOW, DAVID 11 1900 (has links)
International Telemetering Conference Proceedings / October 29-November 02, 1990 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The new generation of advanced tactical aircraft and missiles places unique demands on the electronic and mechanical designs for flight test instrumentation, high bit rates, operating temperature range and system interconnect wiring requirements. This paper describes a microminiature PCM distributed data acquisition system with integral signal conditioning (MMSC) which has been used in advanced aircraft and missile flight testing. The MMSC system is constructed from microminiature, stackable modules which allow the user to reconfigure the system as the requirements change. A second system is also described which uses the same circuitry in hermetic hybrid packages on plug-in circuit boards.
7

Multi-writer consistency conditions for shared memory objects

Shao, Cheng 15 May 2009 (has links)
Regularity is a shared memory consistency condition that has received considerable attention, notably in connection with quorum-based shared memory. Lamport's original definition of regularity assumed a single-writer model, however, and is not well defined when each shared variable may have multiple writers. In this thesis, we address this need by formally extending the notion of regularity to a multi-writer model. We have shown that the extension is not trivial. While there exist various ways to extend the single-writer definition, the resulting definitions will have different strengths. Specifically, we give several possible definitions of regularity in the presence of multiple writers. We then present a quorum-based algorithm to implement each of the proposed definitions and prove them correct. We study the relationships between these definitions and a number of other well-known consistency conditions, and give a partial order describing the relative strengths of these consistency conditions. Finally, we provide a practical context for our results by studying the correctness of two well-known algorithms for mutual exclusion under each of our proposed consistency conditions.
8

Multi-writer consistency conditions for shared memory objects

Shao, Cheng 10 October 2008 (has links)
Regularity is a shared memory consistency condition that has received considerable attention, notably in connection with quorum-based shared memory. Lamport's original definition of regularity assumed a single-writer model, however, and is not well defined when each shared variable may have multiple writers. In this thesis, we address this need by formally extending the notion of regularity to a multi-writer model. We have shown that the extension is not trivial. While there exist various ways to extend the single-writer definition, the resulting definitions will have different strengths. Specifically, we give several possible definitions of regularity in the presence of multiple writers. We then present a quorum-based algorithm to implement each of the proposed definitions and prove them correct. We study the relationships between these definitions and a number of other well-known consistency conditions, and give a partial order describing the relative strengths of these consistency conditions. Finally, we provide a practical context for our results by studying the correctness of two well-known algorithms for mutual exclusion under each of our proposed consistency conditions.
9

Distributed Hierarchical Clustering

Loganathan, Satish Kumar January 2018 (has links)
No description available.
10

A grid-based middleware for processing distributed data streams

Chen, Liang 22 September 2006 (has links)
No description available.

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