In a previous paper by Payeur et al. (1997), probabilistic occupancy modeling has been successfully extended to 3D environments by means of a closed-form approximation of the probability distribution. In this paper, t...
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In a previous paper by Payeur et al. (1997), probabilistic occupancy modeling has been successfully extended to 3D environments by means of a closed-form approximation of the probability distribution. In this paper, the closed-form approximation is revisited in order to provide more reliable and meaningful models. A merging strategy of local probabilistic occupancy grids originating from each sensor viewpoint is introduced. The merging process takes advantage of the multiresolution characteristics of octrees to minimize the computational complexity and enhance performances. An experimental testbed is used to validate the approach and models computed from real range images are presented.
Diffraction spectrum has been widely utilized for optical methods of stress analysis[1].Such application would require a photoelastic *** this paper,the application of simple Michelson interferometer is directed to me...
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Diffraction spectrum has been widely utilized for optical methods of stress analysis[1].Such application would require a photoelastic *** this paper,the application of simple Michelson interferometer is directed to measure the pressure applied to a photoelastic sensing *** measurement is based on the analysis of the optical path difference along the two-interferometer arms and the observation of interference due to the birefringence, which is caused by the pressure *** interference which happen because of the Michelson interferometer and the birefringe show the potential of such a system for wider pressure-sensor application.
MBP(Memory Based Processor)-light is a dedicated processor for management of cache coherent distributed shared memory(DSM) in a massively parallel processor called *** traditional complicated controllers to manage ***...
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MBP(Memory Based Processor)-light is a dedicated processor for management of cache coherent distributed shared memory(DSM) in a massively parallel processor called *** traditional complicated controllers to manage *** provides a simple but powerful 16-bit RISC processor as a *** the other hand,memory controller,bus interface and network packet handler are implemented completely with a hardwired logic to require high-speed operation. Using 0.4μm CMOS embedded array technology and the TBGA(Tape Ball Grid Array) package,it works at 50MHz *** with chips used in Sequent's *** supports almost the same performance with much smaller amount of hardware.
Mobile software objects are computational entities that travel in large-scale and widely-distributed heterogeneous systems, and whose functionality can be attached to diverse computing environments. When employed over...
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ISBN:
(纸本)0818681268
Mobile software objects are computational entities that travel in large-scale and widely-distributed heterogeneous systems, and whose functionality can be attached to diverse computing environments. When employed over decentralized sites with operational and administrative autonomy, support for mobility raises difficult issues with respect to object management services. In particular it impacts persistence, reference handling, object naming, and requires extensive support for security. This paper discusses the requirements from an object management system that incorporates mobile, autonomous and reflective objects and presents the design and implementation of the Mobile Object Manager (MOM) which fulfills these requirements.
No cache based techniques for roll-forward fault recovery exist at present. A split-cache approach is proposed that provides efficient support for checkpointing and roll-forward fault recovery in distributedsystems. ...
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ISBN:
(纸本)0818681268
No cache based techniques for roll-forward fault recovery exist at present. A split-cache approach is proposed that provides efficient support for checkpointing and roll-forward fault recovery in distributedsystems. This approach obviates the use of discrete stable storage or explicit synchronization among the processors. Stability of the checkpoint intervals is used as a driver for real time operations.
This paper reports the development of a cost-effective framework for the implementation of a versatile computer vision system, namely the Cyvis-1. Presenting a strong biological motivation the Cyvis-1 approach is char...
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ISBN:
(纸本)0818681268
This paper reports the development of a cost-effective framework for the implementation of a versatile computer vision system, namely the Cyvis-1. Presenting a strong biological motivation the Cyvis-1 approach is characterized by the multi-stage integration paradigm, which is inherently suitable for parallelization and representation through the OOP/GUI concepts. A model for the parallelization of this system has been developed that incorporates multitasking, distributed processors, and message interchange through channels. The implementation of each of these parallel features in IBM-PC compatible machines running under Windows 95/NT has been described. An application example of RGB image edge and line detection has been presented and assessed in terms of execution rime, efficiency of hardware utilization and speed-up.
Techniques of customizing and extending operating systems (OSs) have a growing impact on system architectures in the field of distributedcomputing and parallel programming. Even if traditional methods of adaption hav...
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ISBN:
(纸本)0780342291
Techniques of customizing and extending operating systems (OSs) have a growing impact on system architectures in the field of distributedcomputing and parallel programming. Even if traditional methods of adaption have been limited to the user-level, modern OSs cannot do without kernel support. Hence concepts and structures of microkernel architectures must be redefined to meet the requirements of today's and future applications. In this paperwork we are proposing a new customizable low-level OS architecture - the Dycos kernel. In a first part we will discuss customization demands on microkernels. In a second part we are passing over to describe the basic kernel concept. Dycos is an object-based approach providing a toolbox of operations to build user-definable compositions of kernel structures. The Dycos approach has been evaluated on a Solaris 2.5.1 platform.
In this paper we put forward a distributed model for accessing heterogeneous database systems. The processing of database operations requested by the user are processed in a distributed manner that takes advantage of ...
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ISBN:
(纸本)0780342291
In this paper we put forward a distributed model for accessing heterogeneous database systems. The processing of database operations requested by the user are processed in a distributed manner that takes advantage of the inherent parallelism of distributedsystems, minimises network traffic and uses almost any general purpose computer on the network. Processing is not confined to DBMS sites but is provided as a distributed service. The design is modular and provides the mechanisms that may be arranged in a variety of ways providing a range of integration paradigms from loosely coupled integrations to more tightly coupled integrations.
Hard real-time multitask-multiprocessor systems are one of the more important species of the taxonomic genus of distributedsystems. The assignment of m preemptible periodic tasks to be executed in a set of n processo...
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ISBN:
(纸本)0818681268
Hard real-time multitask-multiprocessor systems are one of the more important species of the taxonomic genus of distributedsystems. The assignment of m preemptible periodic tasks to be executed in a set of n processors (interconnected through a communications network) is a NP-complete problem that must meet several constraints: time, allocation, resources, communication and precedence. The first three are processor-dependent and the fourth is network-dependent, but all of them can be verified as the assignment process goes on. Precedence constraints, instead, can be best verified when a tentative assignment, meeting the first four constraints, is obtained. In this paper, a formally proved method is presented to validate tentative assignments. In order to solve the problem of fitter in data arrivals, timed release counters are proposed.
In a distributed real-time database system, if data conflicts occur between executing and committing transactions the performance can be severely affected. In this paper, we propose an approach, called deadline driven...
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ISBN:
(纸本)0818681268
In a distributed real-time database system, if data conflicts occur between executing and committing transactions the performance can be severely affected. In this paper, we propose an approach, called deadline driven conflict resolution (DDCR), which integrates concurrency control and commitment management in resolving data conflicts between executing and committing transactions, while at the same time maintaining the schedules to be serializable. With DDCR, many of the data conflicts can be alleviated, and concurrent execution of transactions is allowed to access data items being held by committing transactions. The impact of temporary failures occurred during the commitment of a transaction an other transactions is reduced by reversing the dependencies between the transactions. Simulation experiments have been performed and the results show that DDCR can significantly improve the system performance especially when the duration for the voting phase is long.
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