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.
Channel compensation has been proved to be an effective approach for robust speech recognition. We first use two level cepstral mean substraction (CMS) for channel compensation in telephone speech recognition, and the...
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Channel compensation has been proved to be an effective approach for robust speech recognition. We first use two level cepstral mean substraction (CMS) for channel compensation in telephone speech recognition, and then propose a new channel compensation method, RMFCC. For all experiments, a Korean isolated 84 words database consisting of 80 speakers collected from a local telephone line is adopted. Using the RMFCC, a 39.8% reduction in word error rate is obtained relative to the conventional HMM system. It is shown from the experiments that the RMFCC, compared with RASTA, reduces the computational complexity without losing accuracy, and is also better than the CMS and two level CMS in performance.
Although several access control policies can be devised for controlling access to information, all existing authorization models, and the corresponding enforcement mechanisms, are based on a specific policy (usually t...
ISBN:
(纸本)9780897919111
Although several access control policies can be devised for controlling access to information, all existing authorization models, and the corresponding enforcement mechanisms, are based on a specific policy (usually the closed policy). As a consequence, although different policy choices are possible in theory, in practice only a specific policy can be actually applied within a given system. However, protection requirements within a system can vary dramatically, and no single policy may simultaneously satisfy them *** this paper we present a flexible authorization manager (FAM) that can enforce multiple access control policies within a single, unified system. FAM is based on a language through which users can specify authorizations and access control policies to be applied in controlling execution of specific actions on given objects. We formally define the language and properties required to hold on the security specifications and prove that this language can express all security specifications. Furthermore, we show that all programs expressed in this language (called FAM/CAM-programs) are also guaranteed to be consistent (i.e., no conflicting access decisions occur) and CAM-programs are complete (i.e., every access is either authorized or denied). We then illustrate how several well-known protection policies proposed in the literature can be expressed in the FAM/CAM language and how users can customize the access control by specifying their own policies. The result is an access control mechanism which is flexible, since different access control policies can all coexist in the same data system, and extensible, since it can be augmented with any new policy a specific application or user may require.
In our paper, "An analytical model for designing memory hierarchies" (see ibid., vol. 45, no. 10, p. 180-1, 194 (1996)), we made the following statement: "Failing to apply a specific model of workload l...
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In our paper, "An analytical model for designing memory hierarchies" (see ibid., vol. 45, no. 10, p. 180-1, 194 (1996)), we made the following statement: "Failing to apply a specific model of workload locality makes it impossible to provide an easily used, closed-form solution for the optimal cache configuration, and so the results from these papers have contained dependencies on the cache configuration-the number of levels, or the sizes and hit rates of the levels." Our description did not accurately reflect the contents of the paper by J.E. MacDonald and K.L. Sigworth (1975), and we regret any false impressions caused by the inaccuracy.
As a very promising new data model, constraint database is attracting a growing interest recently. For better applications, we need to study its design theory. But to the best of our knowledge, no papers about the des...
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