Advances in the area of image and voice compression have given way to transmission rates of a few kilobits/second for acceptable quality audio and video. Audio/video conferencing among multiple parties in cellular net...
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Advances in the area of image and voice compression have given way to transmission rates of a few kilobits/second for acceptable quality audio and video. Audio/video conferencing among multiple parties in cellular networks is therefore a distinct possibility. We present an algorithm for designing a mobile cellular network that can support multicasting applications. The mobile network may consist of one or more tiers, which correspond to different user velocities. Communication channels are partitioned across tiers. The objective of network design is to minimize call loss probability by selecting an appropriate frequency reuse pattern and suitably partitioning network resources across tiers. Earlier work in this area has only concentrated on point-to-point communications. We permit multicast communications that may involve users from more than one tier. We describe a cost optimization algorithm for designing cellular networks that can support multicast traffic. We also describe a performance analysis of the designed network through analytical and simulation techniques.
Repetitive, or multipass, processes are a class of 2D systems of both practical and algorithmic/theoretical interest whose dynamics cannot be analysed or controlled using standard (1D) systems theory. Recently it has ...
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Repetitive, or multipass, processes are a class of 2D systems of both practical and algorithmic/theoretical interest whose dynamics cannot be analysed or controlled using standard (1D) systems theory. Recently it has been shown that the modelling of the boundary conditions, also known as the process initial conditions, is a crucial feature in the analysis and control of these processes. This paper presents some further results on the effects of so-called 'dynamic' process initial conditions on the controllability and stability properties of discrete linear repetitive processes. Previous work has shown that these dynamic process initial conditions alone can destroy the stability properties of these processes. Hence their effects must be 'adequately' accounted for the process modelling stage in order to ensure that subsequent analysis does not lead to incorrect results/conclusions. The main results developed in this paper can be summarised as follows. (i) Computationally efficient stability tests which can, in effect, be applied using standard, or 1D, linear systems tests. (ii) Characterisation of so-called pass controllability in the form of matrix rank based conditions. (iii) Conditions under which the dynamic process initial conditions can be selected to ensure stability and pass controllability.
The concept of the "Fixation", meaning to monitor features for identifying transport vehicles is proposed. And a framework of the "Fuzzy Hierarchical Pattern Recognition using a Fixation Feedback (FHPR/...
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The INSERT technology has demonstrated itself scalable to major weapon system avionics software. Initially developed at the SEI for providing software fault tolerance, its clean architecture and COTS approach enables ...
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The INSERT technology has demonstrated itself scalable to major weapon system avionics software. Initially developed at the SEI for providing software fault tolerance, its clean architecture and COTS approach enables its application to many problems. Under DARPA's Evolutionary Design of Complex software, this research has demonstrated the feasibility of using this technology to start with a reliable baseline algorithm, wrap it in the INSERT architecture, then safely and reliably implement new functionality with minimal testing. Along the same lines, one could use this architecture to actually do a "design a little, build a little, test a little" software development approach in real time systems. A design team could use the INSERT Architecture to "bootstrap" an OFP from the ground up and with highly reliable interim versions.
A project is currently underway which involves testing a distributed system-the Run Time Infrastructure (RTI) component of the High Level Architecture (HLA). As part of this effort, a test suite has been designed and ...
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A project is currently underway which involves testing a distributed system-the Run Time Infrastructure (RTI) component of the High Level Architecture (HLA). As part of this effort, a test suite has been designed and implemented to provide a coordinated and automated approach to testing this distributed system. This suite includes the creation and application of a Script Definition Language (SDL) to specify test sequences, and a test executive to control execution of the tests, coordinate the test environment, and record test results. This paper describes the design and implementation of this test environment.
A new distributed test system is used to verify the Runtime Infrastructure (RTI) component of the High Level Architecture (HLA). As part of this effort, a test suite has been designed and implemented to provide a coor...
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A new distributed test system is used to verify the Runtime Infrastructure (RTI) component of the High Level Architecture (HLA). As part of this effort, a test suite has been designed and implemented to provide a coordinated and automated approach to testing this distributed system. This paper describes the application of this test environment and its utility in verifying an HLA RTI.
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