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1.
CMOS器件进入深亚微米阶段,VLSI集成电路(IC)继续向高集成度,高速度,低功耗发展,使得IC在制造、设计、封装,测试上都面临新的挑战,测试已从IC设计流程的后端移至前端,VLSI芯片可测试性设计已成为IC设计中必不可少的一部分,本文介绍近几年来VLSI芯片可测试性设计的趋势,提出广义可测试性设计(TDMS技术)概念,即可测试试性,可调试性,可制造性和可维护性设计,并对可调试性设计方法学和广义可测试性设计的系统化方法作了简单介绍。  相似文献   

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We study the dynamics of expansive cellular automata. We prove that a cellular automaton is expansive if and only if it is topologically conjugate to an appropriate one-sided subshift. We define a large class of expansive cellular automata in terms of the permutivity of the local rule on which they are based. We prove that each cellular automaton of this class is topologically conjugate to a one-sided full shift. Since one-sided full shifts are widely recognized as the paradigm of chaotic systems, we conclude that the above mentioned cellular automata are chaotic according to any reasonable definition of chaos. We provide a technique to construct expansive cellular automata which are topologically conjugate to one-sided full shifts but do not belong to the above defined class. Finally, we investigate connections between expansivity, topological transitivity, and surjectivity. Received February 1996, and in final form October 1997.  相似文献   

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We present a formal semantics for an object-oriented specification language. The formal semantics is presented as a conservative shallow embedding in Isabelle/hol and the language is oriented towards ocl formulae in the context of uml class diagrams. On this basis, we formally derive several equational and tableaux calculi, which form the basis of an integrated proof environment including automatic proof support and support for the analysis of this type of specifications. We show applications of our proof environment to data refinement based on an adapted standard refinement notion. Thus, we provide an integrated formal method for refinement-based object-oriented development.  相似文献   

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This paper studies normalization of typeable terms and the relation between approximation semantics and filter models for Combinator Systems. It presents notions of approximants for terms, intersection type assignment, and reduction on type derivations; the last will be proved to be strongly normalizable. With this result, it is proved that every typeable term has an approximant with the same type, and a characterization of the normalization behaviour of terms using their assignable types is given. Then the two semantics are defined and compared, and it is shown that the approximants semantics is fully abstract but the filter semantics is not.  相似文献   

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The provenance (i.e., origins) of derived information on the Web is crucial in many applications to allow information quality assessment, trust judgments, accountability, as well as understanding the temporal and spatial status of the information. On the other hand, the inclusion of negative information in knowledge representation both in the form of negation-as-failure and explicit negation is also important to allow various forms of reasoning, provided that weakly negated information is associated with the sources (contexts) in which it holds. In this work, we consider collections of g-RDF ontologies, distributed over the web, along with a set of conflict statements expressing that information within a pair of g-RDF ontologies cannot be combined together for deriving new information. A g-RDF ontology is the combination of (i) a g-RDF graph G (i.e., a set of positive and strongly negated RDF triples, called g-RDF triples) and (ii) a g-RDF program P containing derivation rules with possibly both explicit and scoped weak negation. Information can be inferred through the g-RDF graphs or the derivation rules of the g-RDF ontologies, or through the RDFS derivation rules. We associate each derived grounded g-RDF triple [¬] p(s, o) with the set of names S of the g-RDF ontologies that contributed to its derivation. To achieve this, we define the provenance stable models of a g-RDF ontology collection. We show that our provenance g-RDF semantics faithfully extends RDFS semantics. Finally, we provide an algorithm based on Answer Set Programming that computes all provenance stable models of a g-RDF ontology collection and provides the answer to various kinds of queries. Various complexity results are provided.  相似文献   

8.
Ergonomics, gerontechnology, and design for the home-environment   总被引:1,自引:0,他引:1  
An ergonomic approach could improve the quality of life and activities in daily living. Gerontechnology reduces the effects of age-related impairments with technological devices and particular design for the home-environment. Physiological decline with increasing age renders the daily activities at home more difficult. This paper highlights some "common sense" and specific design suggestions in the entrance and kitchen, aimed to increase the self-sufficiency of elderly people. We suggest that gerontechnology may have a particular role in the improvement of comfort and safety for aged people.  相似文献   

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We propose a method for characterizing sound activity in fixed spaces through segmentation, indexing, and retrieval of continuous audio recordings. Regarding segmentation, we present a dynamic Bayesian network (DBN) that jointly infers onsets and end times of the most prominent sound events in the space, along with an extension of the algorithm for covering large spaces with distributed microphone arrays. Each segmented sound event is indexed with a hidden Markov model (HMM) that models the distribution of example-based queries that a user would employ to retrieve the event (or similar events). In order to increase the efficiency of the retrieval search, we recursively apply a modified spectral clustering algorithm to group similar sound events based on the distance between their corresponding HMMs. We then conduct a formal user study to obtain the relevancy decisions necessary for evaluation of our retrieval algorithm on both automatically and manually segmented sound clips. Furthermore, our segmentation and retrieval algorithms are shown to be effective in both quiet indoor and noisy outdoor recording conditions.   相似文献   

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We focus on the mechanism half of the policy-mechanism divide for networked control systems, and address the issue of what are the appropriate abstractions and architecture to facilitate their development and deployment. We propose an abstraction of “virtual collocation” and its realization by the software infrastructure of middleware. Control applications are to be developed as a collection of software components that communicate with each other through the middleware, called Etherware. The middleware handles the complexities of network operation, such as addressing, start-up, configuration and interfaces, by encapsulating application components in “Shells” which mediate component interactions with the rest of the system. The middleware also provides mechanisms to alleviate the effects of uncertain delays and packet losses over wireless channels, component failures, and distributed clocks. This is done through externalization of component state, with primitives to capture and reuse it for component restarts, upgrades, and migration, and through services such as clock synchronization. We further propose an accompanying use of local temporal autonomy for reliability, and describe the implementation as well as some experimental results over a traffic control testbed.   相似文献   

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In this paper we give axiom systems for classical and intuitionistic hybrid logic. Our axiom systems can be extended with additional rules corresponding to conditions on the accessibility relation expressed by so-called geometric theories. In the classical case other axiomatisations than ours can be found in the literature but in the intuitionistic case no axiomatisations have been published. We consider plain intuitionistic hybrid logic as well as a hybridized version of the constructive and paraconsistent logic N4.  相似文献   

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While electronic books (e-books) can make intellectual content more accessible, librarians are faced with uncertainties about e-book acceptance and decreasing materials budgets. What are library user attitudes toward books accessible in print or in electronic form? How might library user attitudes inform the practices of reference, instruction, and collection management librarians? Librarians at a Midwestern public university sought guidance from its users by conducting a survey examining the relative preferences for books in paper and electronic formats. Characteristics of readers and their purposes for using books were explored, as were characteristics of the formats such as accessibility, portability, and convenience.  相似文献   

13.
S.Y.   《Annual Reviews in Control》2007,31(2):281-292
Recent developments in collaborative control theory and e-Work influence the emergence of e-Production and e-Service. The influence includes impacts of e-Work on enterprises, and proliferation of applications of robotics and agents’ services. Our concern is the effective design and implementation of such e-systems. The purpose of this article is to review design principles and collaborative control theory guiding these new developments. The “four wheels” of e-Work, their 15 e-dimensions and their role in e-Production and e-Service are explained and illustrated. Network models and their bio-inspired redesign counterparts are explained with implications to the future of production and service systems.  相似文献   

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A dynamic logic for acting, sensing, and planning   总被引:2,自引:0,他引:2  
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This paper explores the issue of user embodiment within collaborative virtual environments. By user embodiment we mean the provision of users with appropriate body images so as to represent them to others and also to themselves. By collaborative virtual environments we mean multi-user virtual reality systems which explicitly support cooperative work (although we argue that the results of our exploration may also be applied to other kinds of collaborative system). The main part of the paper identifies a list of embodiment design issues grouped by the general themes of personal representation, conveying activity, embodiment in heterogeneous systems, embodiment of agents, and ethical issues. These issues are illustrated with examples from our own DIVE and MASSIVE collaborative virtual environments. The paper also uses this set of issues as an analytical framework for comparing a number of other communication technologies.  相似文献   

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Genomic data visualization is essential for interpretation and hypothesis generation as well as a valuable aid in communicating discoveries. Visual tools bridge the gap between algorithmic approaches and the cognitive skills of investigators. Addressing this need has become crucial in genomics, as biomedical research is increasingly data‐driven and many studies lack well‐defined hypotheses. A key challenge in data‐driven research is to discover unexpected patterns and to formulate hypotheses in an unbiased manner in vast amounts of genomic and other associated data. Over the past two decades, this has driven the development of numerous data visualization techniques and tools for visualizing genomic data. Based on a comprehensive literature survey, we propose taxonomies for data, visualization, and tasks involved in genomic data visualization. Furthermore, we provide a comprehensive review of published genomic visualization tools in the context of the proposed taxonomies.  相似文献   

18.
The existence of a structured, complete project authorization request (PAR) tool significantly aids in the training and growth of project and organizational staff and can be a major source of knowledge sharing. This case study examines one project office that successfully built and implemented such a tool.  相似文献   

19.
A central issue for the design of massively parallel computers is their ability to sort. We consider organizations that are suitable for fast sorting, both those that use point-to-point connections and those that connect processors with multipoint nets. We show that for fast sorting and minimal area, nets must connect at least √n nodes each, if the network has n nodes. We then discuss some of the ways that fast-sorting networks can be used to speed up other processes, such as combinatorial search.  相似文献   

20.
A major goal of this paper is to compare Case-Based Reasoning with other methods searching for knowledge. We consider knowledge as a resource that can be traded. It has no value in itself; the value is measured by the usefulness of applying it in some process. Such a process has info-needs that have to be satisfied. The concept to measure this is the economical term utility. In general, utility depends on the user and its context, i.e., it is subjective. Here, we introduce levels of contexts from general to individual. We illustrate that Case-Based Reasoning on the lower, i.e., more personal levels CBR is quite useful, in particular in comparison with traditional informational retrieval methods.  相似文献   

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