this paper deals with queries involving the retrieval of images that contain certain object configurations. Consider, for instance, that a user wants to "find all images where there exists a building adjacent to ...
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ISBN:
(纸本)9781581130614
this paper deals with queries involving the retrieval of images that contain certain object configurations. Consider, for instance, that a user wants to "find all images where there exists a building adjacent to the west side of a park which is southwest and near a commercial center". this query can be formulated as a constraint satisfaction problem (CSP) where the query variables are nodes of the corresponding constraint network and the image objects constitute the domain of each variable. the arcs of the network correspond to spatial constraints (e.g., adjacent ^ west (X1,X2), southwest ^ near (X2,X3)). Problems of the above nature are, in general, intractable. In addition, spatial constraints (e.g., southwest, near) lack universally accepted semantics and cannot always be modeled by crisp relations;a fact that further complicates query processing. this paper focuses on the development of effective methods that take advantage of the special structure of the spatial domain to achieve good average performance even for large images and queries. Copyright ACM 1998.
there has recently been an explosion of interest in the analysis of data in data warehouses in the field of On-Line Analytical processing (OLAP). Data warehouses can be extremely large, yet obtaining quick answers to ...
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ISBN:
(纸本)9781581130614
there has recently been an explosion of interest in the analysis of data in data warehouses in the field of On-Line Analytical processing (OLAP). Data warehouses can be extremely large, yet obtaining quick answers to queries is important. In many situations, obtaining the exact answer to an OLAP query is prohibitively expensive in terms of time and/or storage space. It can be advantageous to have fast, approximate answers to queries. In this paper, we present an I/O-efficient technique based upon a multiresolution wavelet decomposition that yields an approximate and space-efficient representation of the data cube, which is one of the core OLAP operators. We build our compact data cube on the logarithms of the partial sums of the raw data values of a multidimensional array. We get excellent approximations for on-line range-sum queries with limited space usage and computational cost. Multiple data cubes can be handled simultaneously. Each query can generally be answered, depending upon the accuracy supported, in one I/O or a small number of I/Os. Experiments show that our method performs significantly better than other approximation techniques such as histograms and random sampling. Copyright ACM 1998.
this paper presents a framework of traffic control in high-speed ATM networks on both connection level and cell level. On the connection level, we consider traffic classification, bandwidth allocation, call admission ...
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ISBN:
(纸本)0818690143
this paper presents a framework of traffic control in high-speed ATM networks on both connection level and cell level. On the connection level, we consider traffic classification, bandwidth allocation, call admission control, and billing method. On the cell level we examine a queueing architecture, flow control, and scheduling. We also capture the interdependencies among various traffic control aspects to ensure a proper network operation. the key contribution of this paper is an integrated methodology to handle bursty data traffic. Based on the per-VC queueing architecture, we introduce (1) a simple bandwidth allocation mechanism which requires no complex computation for call admission control, (2) an improved credit-based flow control scheme which ensures lossless and congestion-free cell transport, (3) an innovative scheduling algorithm withthroughput guarantee, and (4) an easy billing method which imposes tariff on bursty data flows without real-time measurement and processing.
A new hardware structure for implementation of soft morphological filters is presented in this paper. this is based on the modification of the majority gate technique. A pipelined systolic array architecture suitable ...
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the efficient query processing for complex spatial objects is one of most challenging requirements in many non-traditional applications such as geographic information systems, computer-aided design and multimedia data...
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ISBN:
(纸本)9783540616566
the efficient query processing for complex spatial objects is one of most challenging requirements in many non-traditional applications such as geographic information systems, computer-aided design and multimedia databases. the performance of spatial query processing can be improved by decomposing a complex object into a small number of simple components. this paper investigates a natural trade-off between the number and the complexity of decomposed components. In particular, we propose a new object decomposition method which can control the number of components using a parameter. the proposed method is able to fine-tune the trade-off by controlling the parameter. An optimal value of the parameter is explored through experimental measurements. the decomposition method withthis optimal value outperforms traditional decomposition methods. the gain by applying the optimal value is more clear as the complexity of spatial objects increases.
VIENA Classroom is a distance education system in which the teaching material is prepared as hypermedia documents and presented to the students within a CSCW environment. By applying language engineering techniques to...
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ISBN:
(纸本)354061656X
VIENA Classroom is a distance education system in which the teaching material is prepared as hypermedia documents and presented to the students within a CSCW environment. By applying language engineering techniques to the question support facilities of the system we create a multimodal natural language interface so that the students can formulate their questions directly in Japanese. Based on the computed semantic representations the questions are either answered by accessing a FAQ knowledge base or collected and transferred to the teacher for later processing. As valuable assistance for formulating questions we provide the possibility to browse through automatically generated FAQ lists. Language engineering is performed in an integrated framework by utilizing deductive object-oriented database technology.
Mobility is the cause for new requirements on database systems. Database systems used in classical LAN- or host-based environments provide these new features deficiently. New concepts are needed in mobile environments...
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ISBN:
(纸本)354061656X
Mobility is the cause for new requirements on database systems. Database systems used in classical LAN- or host-based environments provide these new features deficiently. New concepts are needed in mobile environments. the conventional client-server architecture has to extended in a client-agent-server architecture. We describe new approaches in database technology to meet the new requirements like adaptive database system components and intensified use of query statistics. this includes the management of queries and query results. the access to the information will be done via an OQL-like interface. the OQL query will be transformed into queries of the underlying relational or object-oriented database systems used by the information servers. Mobile computing withthe help of small devices via wireless networks is in our opinion only one possible mobile scenario. In this paper we present a new and more general interpretation of mobility based on mobility of users.
Most of the common techniques for estimating conditional probability densities are inappropriate for applications involving periodic variables. In this paper we introduce three novel techniques for tackling such probl...
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We construct a mixture of locally linear generative models of a collection of pixel-based images of digits, and use them for recognition. Different models of a given digit are used to capture different styles of writi...
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Deformable models are an attractive approach to recognizing nonrigid objects which have considerable within class variability. However, there are severe search problems associated with fitting the models to data. We s...
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