Security management is one of the key functional areas in open systems network management. Two key aspects of security management are managing user security services and providing security to network management system...
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Security management is one of the key functional areas in open systems network management. Two key aspects of security management are managing user security services and providing security to network management systems. These are examined in tum to give the reader an overview of the state-of-the-art in security management. The ISO OSI Reference Model is used as a basis to present the security threats, security services and mechanisms which have to be managed. Telecommunications management networks are used as an example of management applications which both provide management and require the provision of security and security management services. The OSI approach to network management is examined in detail. This is followed by a survey of the categories of OSI security management activities, and a discussion of the security management needs of various common security services. The need for security for network management systems is examined.
Contents and implementation of a computer laboratory for undergraduate electromagnetics are described. The laboratory consists of four 3-hour sessions covering vector calculus, Maxwell's equations (integral and di...
Contents and implementation of a computer laboratory for undergraduate electromagnetics are described. The laboratory consists of four 3-hour sessions covering vector calculus, Maxwell's equations (integral and differential forms), wave propagation in materials, and wave behavior at planar interfaces. Each session contains theory (in the Help file), animations (where relevant) and a quiz. The program runs on IBM compatible 486-based PCs in a Windows environment and uses the Borland C ++ 4.0 compiler.
The processing of a join query in a distributed environment exacts the usage of both the network and its computational facilities. A formulation that accounts for both, and felicitously constructed as an integer linea...
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The processing of a join query in a distributed environment exacts the usage of both the network and its computational facilities. A formulation that accounts for both, and felicitously constructed as an integer linear program, is proposed. Information disseminated among the sites of a distributed system is to be amalgamated and presented to a user, in response to his request. From all possible strategies by which this might be achieved, one necessitating the smallest usage of system resources is to be chosen. The data transferal resources of the network are usually presumed to be of greatest significance, and therefore, an optimal strategy is most often defined to be one which minimizes the total transmission cost. One model conforming to this philosophy, appearing in [1), expediently takes the form of a linear integer program, and so forms the basis for further refinement. In the omission of processing costs, the various processor elements of the network are treated homologously;dissimilarities in processing ability are also ignored. By analyzing the nature of join computations at a single processor, the minimal transmission cost model can be hybridized to incorporate the cost of such computations and differences in processing power.
It is proposed that the execution of a chain query in a distributed system can be usefully and appropriately modeled as an integer linear program. In response to a user request, information in the form of relational t...
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It is proposed that the execution of a chain query in a distributed system can be usefully and appropriately modeled as an integer linear program. In response to a user request, information in the form of relational tables scattered across the network is to be combined and made available to the user. The formulation initially attained by considering the behavior of the distributed system in processing such a query is then reduced by removing redundant linear constraints, to produce a model of minimal transmission cost execution. In view of varying properties displayed by the possibly many optima of this problem, further attention is devoted to discriminating between them. By perturbing the objective function, those solutions requiring fewer network transmissions can be favored at the expense of equal-cost, but more complicated, strategies. This includes those strategies that may specify the transmission of a relation around a cycle;when the costs of transmission between sites forming the cycle are zero, such a solution might otherwise be optimal. Many different ways have been devised to solve programs having some number of variables restricted to taking only integer values in some interval, and virtually any of these might be used to solve the join query model. One possible method, using a tree-search approach, is discussed here.
作者：
LAVAGETTO, FCURINGA, SDIST
Department of Communication Computer and Systems Science University of Genova Via Opera Pia 11a Genova I-16145 Italy
This paper describes a new approach to very low bit-rate interpersonal visual communication based on suitable scene model, i.e. a flexible structure adapted to the specific characteristics of the speaker's face. T...
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This paper describes a new approach to very low bit-rate interpersonal visual communication based on suitable scene model, i.e. a flexible structure adapted to the specific characteristics of the speaker's face. The face model is dynamically adapted to time-varying facial expressions by means of few parameters, estimated from the analysis of the real image sequence, which are used to apply knowledge-based deformation rules on a simplified muscle structure. Facial muscles are distributed in correspondence to the primary facial features and can be activated through the direct stimulation of each individual fiber or, indirectly, by interaction with adjacent stimulated fibers. The analysis algorithms performed of the transmitter to estimate the model parameters are based on feature-oriented operators aimed at segmenting the real incoming frames and at the extraction of the primary facial descriptors. The analysis/synthesis algorithms have been developed on a Silicon Graphics workstation and have been tested on various 'head-and-shoulder' sequences: the obtained results are very promising for applications both in videophone coding and in picture animation, where the facial expressions of a synthetic actor is reproduced according to the parameters extracted from a real speaking face.
Most structured design methods claim to address the needs of hard real-time systems. However, few contain abstractions which directly relate to common hard real-time activities, such as periodic or sporadic processes....
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Most structured design methods claim to address the needs of hard real-time systems. However, few contain abstractions which directly relate to common hard real-time activities, such as periodic or sporadic processes. Furthermore, the methods do not constrain the designer to produce systems which can be analyzed for their timing properties. In this article we present a structured design method called HRT-HOOD (Hard Real-Time Hierarchical Object Oriented Design). HRT-HOOD is an extension of HOOD, and includes object types which enable common hard real-time abstractions to be represented. The method is presented in the context of a hard real-time system life cycle, which enables issues of timeliness and dependability to be addressed much earlier on in the development process. We argue that this will enable dependable real-time systems to be engineered in a more cost effective manner than the current practice, which in effect treats these topics as performance issues. To illustrate our approach we present a simple case study of a Mine Drainage Control System, and show how it can be designed using the abstractions presented in the article.
The paper presents an enhancement to the OSF DCE platform for distributed computing that is designed to enhance interoperability of applications. Concepts from Open distributed Processing have been taken, extended and...
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The rapid advances in computer and communication technologies, and their merger, is leading to a global information market place. It will consist of federations of very large number of information systems that will co...
ISBN:
(纸本)9780897916745
The rapid advances in computer and communication technologies, and their merger, is leading to a global information market place. It will consist of federations of very large number of information systems that will cooperate to varying extents to support the users' information needs. We discuss an approach to information brokering in the above environment. We discuss two of its tasks: information resource discovery, which identifies relevant information sources for a given query, and query processing, which involves the generation of appropriate mapping from relevant but structurally heterogeneous objects. Query processing consists of information focusing and information *** approach is based on: semantic proximity, which represents semantic similarities based on the context of comparison, and schema correspondences which are used to represent structural mappings and are associated with the context. The context of comparison of the two objects is the primary vehicle to represent the semantics for determining semantic proximity. Specifically, we use a partial context representation to capture the semantics in terms of the assumptions in the intended use of the objects and the intended meaning of the user query. Information focusing is supported by subsequent context comparison. The same mechanism can be used to support information resource discovery. Context comparison leads to changes in schema correspondences that are used to support information correlation.
Two different approaches are here presented for converting speech into graphic animation, suitable to lipreading. Coarticulation modeling has been taken into account by means of an original algorithm for multistep sta...
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Very high compression in videophone coding can be reached successfully only if model-based segmentation is performed to allow suitable bit allocation. The exploitation of a priori knowledge suggests the application of...
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Very high compression in videophone coding can be reached successfully only if model-based segmentation is performed to allow suitable bit allocation. The exploitation of a priori knowledge suggests the application of fast and simple segmentation algorithms oriented at partitioning the image into variable resolution domains for subsequent texture encoding. In this paper we describe, together with the achieved preliminary results, a model-based approach to image segmentation relying on the estimation of the face symmetry axis and of the primary facial features. Through these parameters a flexible lattice is adapted frame by frame on the image, identifying a time-varying net of triangular patches whose texture is eventually encoded via Legendre basis functions. Target applications for videophone coding of QCIF color sequences at very low bitrate, less than 16 Kbit/sec., are foreseen.< >
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