A distributed computing system consists of heterogeneous computing devices, communication networks, operating system services, and applications. As organisations move toward distributed computing environments, there w...
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A distributed computing system consists of heterogeneous computing devices, communication networks, operating system services, and applications. As organisations move toward distributed computing environments, there will be a corresponding growth in distributed applications central to the enterprise. The design, development, and management of distributed applications presents many difficult challenges. As these systems grow to hundreds or even thousands of devices and similar or greater magnitude of software components, it will become increasingly difficult to manage them without appropriate support tools and frameworks. Further, the design and deployment of additional applications and services will be, at best, ad hoc without modelling tools and timely data on which to base design and configuration decisions. This paper presents a framework for management of distributed applications and systems. The framework is based on a set of common management services that support management activities. The services include monitoring, control, configuration, and data repository services. A prototype system built on the framework is described that implements and integrates management applications providing visualisation, fault location, performance monitoring and modelling, and configuration management. The prototype also demonstrates how various management services can be implemented.
It is a crucial factor to find the robust and simple computation methods for the actual application of telephone speech recognition. In this paper, we propose a new channel compensation method, which uses a RASTA-like...
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The transportation of prerecorded, compressed video data without loss of picture quality requires the network and video servers to support large fluctuations in bandwidth requirements. Fully utilizing a client-side bu...
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The transportation of prerecorded, compressed video data without loss of picture quality requires the network and video servers to support large fluctuations in bandwidth requirements. Fully utilizing a client-side buffer for smoothing bandwidth requirements can limit the fluctuations in bandwidth required from the underlying network and the video-on-demand servers. This paper shows that, for a fixed-size buffer constraint, the critical bandwidth allocation technique results in plans for continuous playback of stored video that have (1) the minimum number of bandwidth increases, (2) the smallest peak bandwidth requirements, and (3) the largest minimum bandwidth requirements. In addition, this paper introduces an optimal bandwidth allocation algorithm which, in addition to the three critical bandwidth allocation properties, minimizes the total number of bandwidth changes necessary for continuous playback. A comparison between the optimal bandwidth allocation algorithm and other critical bandwidth-based algorithms using 17 full-length movie videos and 3 seminar videos is also presented.
An early version of the Z Standard included the deductive system W for reasoning about Z specifications. Later versions contain a different deductive system. In this paper we sketch a proof that W is relatively sound ...
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ISBN:
(纸本)3540627170
An early version of the Z Standard included the deductive system W for reasoning about Z specifications. Later versions contain a different deductive system. In this paper we sketch a proof that W is relatively sound with respect to this new deductive system. We do this by demonstrating a semantic basis for a correspondence between the two systems, then showing that each of the inference rules of W can be simulated as derived rules in the new system. These new rules are presented as tactics over the the inference rules of the new deductive system.
Knowledge-Based systems (KBS) are developed to contain substantial elements of human knowledge and expertise in a well-defined domain, and use these to support user or expert tasks. Issues related to the social and or...
Knowledge-Based systems (KBS) are developed to contain substantial elements of human knowledge and expertise in a well-defined domain, and use these to support user or expert tasks. Issues related to the social and organisational contexts of these systems are widely acknowledged to be particularly critical to their success. However, methodology proposals usually stop short of adequately handling soft and unstructured data that frame the contexts of use. The handling of qualitative data needs to be done in a way that directly impinges on the wider Knowledge-Based System engineering processes and decisions. In this paper, we discuss the nature of context-sensitive issues, and describe a methodological approach for resolving them through the rigorous analysis of qualitative data, using a methodology which is based upon the Grounded Theory method from the social sciences.
Use of formal specification does not a priori guarantee correctness. So far a number of animation approaches have been used for validating formal specification correctness. However, they require complex validation pro...
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ISBN:
(纸本)0818682183
Use of formal specification does not a priori guarantee correctness. So far a number of animation approaches have been used for validating formal specification correctness. However, they require complex validation procedures and exhaustive testing and have some intrinsic limitations. On the other hand, formal specification can be validated by showing that certain properties are logical consequences of the specification, which is called formal reasoning or verification. Tool support, in particular an automated theorem prover, is needed for this task. We discuss some experiences in formal specification validation with the automated theorem prover.
作者：
R.I. DamperImage
Speech and Intelligent Systems ISIS Research Group Department of Electronics and Computer Science University of Southampton Southampton UK Center for Spoken Language Understanding
Department of Computer Science and Engineering Oregon Graduate Institute of Science and Technology Portland OR USA
Important aspects of the voiced/unvoiced categorization of synthetic syllable-initial stop consonants are reproduced by a two stage biocybernetic simulation of the auditory system. This behavior is emergent - it is no...
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Important aspects of the voiced/unvoiced categorization of synthetic syllable-initial stop consonants are reproduced by a two stage biocybernetic simulation of the auditory system. This behavior is emergent - it is not explicitly programmed into the model - and no fine timing information is necessary. Unlike real (human and animal) listeners, the computational auditory model can be systematically manipulated and probed to determine the basis of its behavior. This reveals the importance of the region of first formant onset to the perception of voicing for these stimuli. Spectral analysis of this region in the raw stimuli show that processing by the first stage of the model, mimicking the functions of the peripheral auditory system, is not essential to the observed behavior. Thus, in this case at least, the phonetic perception of voicing is directly recoverable from both acoustic and auditory representations of the stimuli.
In this paper we present a method and a tool for modelling a teletraining session in heterogenous, distributed open environments. We propose a mathematical notion for the training process. Therefore we divide a whole ...
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In this paper we present a method and a tool for modelling a teletraining session in heterogenous, distributed open environments. We propose a mathematical notion for the training process. Therefore we divide a whole training session into presentation units, define some relations on these units and develop a controller for running the session. Units consist of multimedia objects, such as text, graphics, video and audio, which have to be displayed with time and space synchronisation and coordination. In a related project at the department of softwareengineering at the Upper Austria Polytechnic University a tool for modelling and running such teletraining sessions was developed. It is based on the herein defined formalism and compiles well defined unit models into JAVAT/sup TM/ code, which can be executed by usual WEB-Browsers.
We describe the application of model checking tools to analyze a real-time software challenge in the design of Lucent Technologies' 5ESS telephone switching system. We use two tools: COSPAN for checking real-time ...
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ISBN:
(纸本)0897919149
We describe the application of model checking tools to analyze a real-time software challenge in the design of Lucent Technologies' 5ESS telephone switching system. We use two tools: COSPAN for checking real-time properties, and TPWB for checking probabilistic specifications. We report on the feedback given by the tools, and based on our experience, discuss the advantages and the limitations of the approach used.
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