Web-based 3D virtual environments suffer from the classic problem of users getting 'lost-in-cyberspace'. Apart from getting lost, it is hard for an average user to discover all that a specific world has to off...
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ISBN:
(纸本)1581133391
Web-based 3D virtual environments suffer from the classic problem of users getting 'lost-in-cyberspace'. Apart from getting lost, it is hard for an average user to discover all that a specific world has to offer without spending considerable time exploring that world. In order to remedy this situation we propose navigation by query. The user interface for 3D virtual environments usually allows users to 'walk' around in the virtual world. Navigation by query augments this interface by allowing users to navigate a virtual world by means of querying its content. We present the concept of navigation by query and discuss the requirements for an implementation for a VRML based environment. Additionally we illustrate problems an implementation must solve by presenting a prototype implementation.
In this paper, we propose and analyze a simple adaptive uplink power control scheme, called two-level channel inversion, for data traffic in a cellular CDMA system. The basic idea is to reduce out-cell interference by...
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In this paper, we propose and analyze a simple adaptive uplink power control scheme, called two-level channel inversion, for data traffic in a cellular CDMA system. The basic idea is to reduce out-cell interference by reducing the rate of, or even suspending, transmission when the wireless channel is in a bad condition. We first describe the scheme in detail, and then present a probabilistic analysis model for evaluating the system performance. With this model, we determine the queueing delay and system throughput. Numerical results show that in comparison with the traditional channel inversion scheme, the two-level channel inversion scheme can substantially improve system throughput at a moderate cost of extra queueing delay. Finally, we present a design algorithm to optimize the overall performance while maintaining each user's quality of service (QoS).
This paper describes the crucial role of Systems engineering and knowledge Management in business. The importance of postgraduate education in both systems engineering in general and knowledge management in particular...
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This paper describes the crucial role of Systems engineering and knowledge Management in business. The importance of postgraduate education in both systems engineering in general and knowledge management in particular is stressed and the subjects are discussed with particular reference to two distance learning MSc courses. These two degrees both plan to use the Barrington virtual building for delivery over the World Wide Web (WWW) in order to deliver real benefits to the workplace and to provide an effective knowledge Management medium to support the educational process.
Human computer interaction can be specified successfully using the concept of information resources and the formal notation of graph grammars. In order to achieve a precise and continuous specification process between...
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Computation intensive DSP applications usually require parallel/pipelined processors in order to meet specific timing requirements. data hazards are a major obstacle against the high performance of pipelined systems. ...
Computation intensive DSP applications usually require parallel/pipelined processors in order to meet specific timing requirements. data hazards are a major obstacle against the high performance of pipelined systems. This paper presents a novel efficient loop scheduling algorithm that reduces data hazards for such DSP applications. This algorithm has been embedded in a tool, called SHARP, which schedules a pipelined data flow graph to multiple pipelined units while hiding the underlying data hazards and minimizing the execution time. This paper reports significant improvement for some well-known benchmarks showing the efficiency of the scheduling algorithm and the flexibility of the simulation tool.
Multithreading support seems to be the most obvious approach for helping programmers to take the advantage of parallelism by operating systems. Although multithreading for a lot of multiprocessors is powerful, we some...
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Multithreading support seems to be the most obvious approach for helping programmers to take the advantage of parallelism by operating systems. Although multithreading for a lot of multiprocessors is powerful, we sometimes still lack good parallelizing compilers to help programmers exploit parallelism and gain performance benefit. In this paper, a model of FORTRAN parallelizing compiler on multithreading OSF/1 is first proposed and then generalized to be useful hi constructing a parallelizing compiler for a particular language, to generate insight into the development of a high-performance parallelizing compiler.
007, an intelligent modeling assistant, helps users formulate explicit, testable requirements and assess the current model. It then executes generic repair plans and revises the model until requirements are met.
007, an intelligent modeling assistant, helps users formulate explicit, testable requirements and assess the current model. It then executes generic repair plans and revises the model until requirements are met.
We should consider semistructured data of which have a weak schema information in networked information world. To manage such semistructured data efficiently, this paper introduces a data model for semistructured data...
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