The minimum test collection problem is defined as follows. Given a ground set S and a collection C of tests (subsets of S), find the minimum subcollection C‘ of C such that for every pair of elements (x;y) in S there...
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Responsibility for management of the main memory of each machine in a network of workstations has migrated from the paging concept to an object structure. We propose a new hybrid memory management mechanism that combi...
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Responsibility for management of the main memory of each machine in a network of workstations has migrated from the paging concept to an object structure. We propose a new hybrid memory management mechanism that combines the advantages of both pages and objects while avoiding their disadvantages. Our approach is based on the inherent relationship among objects for caching different type of remote pages and objects. High-profile and low-profile objects with their respective h-cache and h-cache axe introduced. We implemented our technique through simulation and showed that it dramatically reduces miss-penalties and outperforms earlier methods.
This paper describes a chat room application suitable for teaching basic network programming and security protocols. A client/server design illustrates the structure of current scalable network services while a multic...
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This paper describes a chat room application suitable for teaching basic network programming and security protocols. A client/server design illustrates the structure of current scalable network services while a multicast version demonstrates the need for efficient simultaneous distribution of network content to multiple receivers (e.g., as required by video broadcasts). The system also includes implementations of two security protocols, one similar to Kerberos and another based on public key encryption.
We deal with the problem of a center sending a messageto a group of users such that some subset of the users is consideredrevoked and should not be able to obtain the content of the *** concentrate on the stateless re...
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Dynamic events can be regarded as long-term temporal objects, which are characterized by spatio-temporal features at multiple temporal scales. Based on this, we design a simple statistical distance measure between vid...
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ISBN:
(纸本)0769512720
Dynamic events can be regarded as long-term temporal objects, which are characterized by spatio-temporal features at multiple temporal scales. Based on this, we design a simple statistical distance measure between video sequences (possibly of different lengths) based on their behavioral content. This measure is non-parametric and can thus handle a wide range of dynamic events. We use this measure for isolating and clustering events within long continuous video sequences. This is done without prior knowledge of the types of events, their models, or their temporal extent. An outcome of such a clustering process is a temporal segmentation of long video sequences into event-consistent sub-sequences, and their grouping into event-consistent clusters. Our event representation and associated distance measure can also be used for event-based indexing into long video sequences, even when only one short example-clip is available. However, when multiple example-clips of the same event are available (either as a result of the clustering process, or given manually), these can be used to refine the event representation, the associated distance measure, and accordingly the quality of the detection and clustering process.
This paper shows how two image sequences that have no spatial overlap between their fields of view can be aligned both in time and in space. Such alignment is possible when the two cameras are attached closely togethe...
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ISBN:
(纸本)0769511430
This paper shows how two image sequences that have no spatial overlap between their fields of view can be aligned both in time and in space. Such alignment is possible when the two cameras are attached closely together and are moved jointly in space. The common motion induces "similar" changes over time within the two sequences. This correlated temporal behavior is used to recover the spatial and temporal transformations between the two sequences. The requirement of "coherent appearance" in standard image alignment techniques is therefore replaced by "coherent temporal behavior", which is often easier to satisfy. This approach to alignment can be used not only for aligning nan-overlapping sequences, but also for handling other cases that are inherently difficult for standard image alignment techniques. We demonstrate applications of this approach to three real-world problems: (i) alignment of non-overlapping sequences for generating wide-screen movies, (ii) alignment of images (sequences) obtained at significantly different zooms, for surveillance applications, and (iii) multi-sensor image alignment for multi-sensor fusion.
Prototyping in the development cycle claims to improve analyst understanding of system requirements leading to systems which match those requirements more closely. The quality of the end systems, from a user perspecti...
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Prototyping in the development cycle claims to improve analyst understanding of system requirements leading to systems which match those requirements more closely. The quality of the end systems, from a user perspective, is thus improved. In this paper, the results of an empirical investigation into the use of prototyping in the development of various systems is described. Nine processes across eight different sites were analysed and data relating to each process was collected. The notation of Role Activity Diagrams (RADs) was used to capture each of the nine processes. Five hypotheses were then investigated: these related the prototyping role to features of other roles such as extent of interaction during the prototyping process, the effect site size had on the prototyping role and the dependence of the prototyping role on other roles in the prototyping process. Two coupling metrics were introduced to quantitatively analyse these RAD features. Results indicated a strong similarity between large and medium-sized sites in terms of interactions and behaviour. The prototyping process in small sites, however, was found to be different to large and medium-sized sites in both respects. The study demonstrates how measures of business models can aid analysis of the process as well as the products of systems development and highlights the need for more empirical investigation into this and other facets of the software development process.
Representation theorems for systems of regions have been of interest for some time, and various contexts have been used for this purpose: Mormann has demonstrated the fruitfulness of the methods of continuous lattices...
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ISBN:
(纸本)1581133774
Representation theorems for systems of regions have been of interest for some time, and various contexts have been used for this purpose: Mormann has demonstrated the fruitfulness of the methods of continuous lattices to obtain a topological representation theorem for his formalisation of Whiteheadian ontological theory of space;similar results have been obtained by Roeper. In this note, we prove a topological representation theorem for a connection based class of systems, using methods and tools from the theory of proximity spaces. The key novelty is a new proximity semantics for connection relations.
作者：
Ahmad Nasri[a]Gerald Farin[b][a]American University of Beirut
Department of Math. and Computer Science Faculty of Arts & Sciences PO Box 11-236 Beirut Lebanon E-mail: [b]Arizona State University Computer Science and Engineering Tempe AZ 85287 E-mail:
The well-known Chaikin algorithm generates uniform quadratic Bspline curves by repeating the process of cutting off the corners of a polygon. One disadvantage of this algorithm is the incapability of generating circle...
The well-known Chaikin algorithm generates uniform quadratic Bspline curves by repeating the process of cutting off the corners of a polygon. One disadvantage of this algorithm is the incapability of generating circles. This paper proposes a modification of this algorithm to produce piecewise rational curves; in particular a circle is produced from a given square. For a general control polygon, every two subsequent polygon legs of equal length will correspond to a circular arc. Such an arc will be parameterized by arc length and will remain circular under affine transformations. Both properties are not shared by the standard rational quadratic form.
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