The trend in implementing today's embedded applications is toward the use of commercial-off-the-shelf open architecture. Reducing costs and facilitating systems integration are among the motives for that trend. Th...
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The trend in implementing today's embedded applications is toward the use of commercial-off-the-shelf open architecture. Reducing costs and facilitating systems integration are among the motives for that trend. The use of the VME bus becomes very common in many industrial applications. The VME bus attracts developers with its rigorous specifications, multiprocessing support and boards availability through multiple vendors. However, VME bus standard supports multiprocessing through shared memory, which does not impose strong function partitioning and allows fault propagation from one board to another. Such weakness limits the use of the VME bus in highly critical applications such as avionics. This paper presents techniques for strong partitioning of multiprocessor applications that maintains fault containment on the VME bus. The suggested techniques do not require any modification in the standard and the existing boards, and consequently maintains the plug-and-play advantage of the VME bus hardware products. The techniques are equally applicable to other tightly coupled multiprocessor systems. In addition, the paper describes the implementation of these techniques and reports performance results. Finally, the benefits of this technology for a space vehicle and commercial avionics are discussed.
Cell delay variation(CDV) is one of the quality of service parameters that can be negotiated between applications and an ATM *** network should check during connection setup, as part of call admission control,whether ...
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Cell delay variation(CDV) is one of the quality of service parameters that can be negotiated between applications and an ATM *** network should check during connection setup, as part of call admission control,whether it can satisfy the requested CDV of an *** this comparison,the network should estimate the end-to-end CDV that it can support,by using local information about cell delays and delay variations in *** accurate estimation of the end-to-end CDV is important for decreasing call-blocking probability and increasing network *** this article,we will first describe,evaluate,and identify the short-comings of three proposed methods for end-to-end CDV *** we will present a new method based on Chernoff bound and compare it to the other *** Chernoff method is promising since it has good accuracy and applicability under current signaling support for ATM networks.
SNMPv2 management tools for networks based on Novell NetWare and TCP/IP facilitate management of individual network workstations which allows a very detailed description of the network operation to be constructed. Usi...
There is a need for information exchange and communication between management applications that are distributed over a large system. In this situation, a fundamental problem is how the management systems should cooper...
Effective communication requires support for interactive (e.g. telephony) as well as message-based (e.g. electronic mail, fax) communication. Message-based communication has the advantage for users in that it allows t...
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Effective communication requires support for interactive (e.g. telephony) as well as message-based (e.g. electronic mail, fax) communication. Message-based communication has the advantage for users in that it allows the recipient to answer and react to incoming correspondences when it suits them. Given the number of varying and differing message-based communication systems available and used these days, it is becoming necessary for users to flurry through an increasing array of 'mail boxes'. This leads to much unnecessary time being spent sorting and filing such messages into separated folders, file systems, etc. This paper introduces the basis for a Personal Message Centre (PMC). The PMC provides its users with one common message store for ail message communications. In addition, PMC users will have the possibility to access such a common message store from a range of terminal types, such as computer terminals, mobile/fixed fixed telephones. Users will be provided with a range of services to assist them in their personal communications tasks. (C) 1997 Elsevier science B.V.
The provision of services such as credit card facilities using Intelligent networks (IN) depends upon the ability to process real-time data. If their data is deliberately delayed during transit, these services may not...
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The provision of services such as credit card facilities using Intelligent networks (IN) depends upon the ability to process real-time data. If their data is deliberately delayed during transit, these services may not be able to function accurately. This paper examines INs and highlights their vulnerability to network delay attacks. In particular, the nature of rear-time communications and the main approach that has been developed to determine whether received data is being sent in real-time or not is discussed. The deficiencies in this approach in terms of its ability to counteract the different forms of a network delay attack are highlighted and an alternative method which addresses these drawbacks is presented. Finally, the results achieved following the implementation and subsequent testing of the alternative approach are discussed. (C) 1997 Elsevier science B.V.
Several international standards for asynchronous data compression are available today. In 1993 the International Telecommunication Union (ITU) started to research possible ways to compress synchronous data. Special at...
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Several international standards for asynchronous data compression are available today. In 1993 the International Telecommunication Union (ITU) started to research possible ways to compress synchronous data. Special attention was given to compatibility with previous asynchronous standards, namely V.42bis. In September 1993 a proposal for modification of the V.42bis standard to make ii applicable to synchronous data was published. In this paper a prototype of a synchronous data link layer protocol based on the ITU proposals is described. The protocol chosen is HDLC based. The V.42bis compression standard is adapted to serve the needs of a synchronous protocol. A functional model is designed followed by a performance analysis of the protocol. The analysis shows a decrease of the compression ratio due to the adaption of the compression algorithm. (C) 1997 Elsevier science B.V.
This paper proposes a multicasting strategy for multimedia services in multiple heterogeneous networks. By incorporating the Internet protocols used for multimedia services such as RTP (real time transport protocol) a...
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ISBN:
(纸本)0780336763
This paper proposes a multicasting strategy for multimedia services in multiple heterogeneous networks. By incorporating the Internet protocols used for multimedia services such as RTP (real time transport protocol) and RSVP (resource reservation protocol), into the CBT (core based trees) multicasting protocol, the deficiencies that the currently used multicasting protocols over the Internet have in supporting the heterogeneous QoS (quality of service) are supplemented. This paper introduces two concepts for the embodiment of the proposed multicasting strategy in a real-time communication protocol model supporting heterogeneous QoS. One is a synchronization core, a node with special functions similar to the ones of an RTP mixer or translator. The other is the SCBT (synchronization-CBT), a CBT with synchronization cores. This paper also discusses design factors to be extended in order to support the heterogeneous QoS classes, and service primitives for the interface among the network components. Finally, a computer simulation is carried out to compare the performance of the SCBT with DVMRP (distance vector multicast routing protocol) and CBT (core based tree).
This paper presents a new technique to derive features for images that are translated, scaled equally/unequally and rotated. The problem is formulated using conventional regular moments. It is shown that the conventio...
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This paper presents a new technique to derive features for images that are translated, scaled equally/unequally and rotated. The problem is formulated using conventional regular moments. It is shown that the conventional regular moment-invariants remain no longer invariant when the image is scaled unequally in the x- and y-directions. A method is proposed to form moment-invariants that do not change under such unequal scaling. The newly formed moments are also invariant to translation and reflection. However, it is not invariant for images that are rotated. A neural network is trained to estimate the angle of rotation; it is then used to derive the invariant moments for images that are unequally scaled, translated and rotated. computer simulation results are also included to show the validity of the method proposed.
This paper proposes an aproach to designing animal-like behavior of autonomous robots with use of a five-layered hierarchical model of the relation between consciousness and behavior. The hierarchy of behavior include...
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