Data uncertainty is an inherent property in various applications due to reasons such as measurement errors, incompleteness of data and so on. While On-Line Analytical Processing (OLAP) has been a powerful method for a...
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Data uncertainty is an inherent property in various applications due to reasons such as measurement errors, incompleteness of data and so on. While On-Line Analytical Processing (OLAP) has been a powerful method for analyzing large data warehouse, OLAP over uncertain data has become a valuable and attractive issue because of the increasingly demand for handling uncertainty in multidimensional data. In this paper, we firstly describe our UStar-Schema model that extends the traditional OLAP model to support uncertain dimension attributes in fact table, uncertain measures in fact table and uncertainty in dimension table. Then we extend the processing model of the aggregate queries and cube computing on Ustar-Schema. Secondly, we design a novel index structure called PSI-Index on UStar-Schema to improve efficiency of OLAP quering and cube computing. Furthermore, an advanced index structure called HB-Index and an efficient algorithm are proposed to accelerate iceberg cube computing based on our model using pruning techniques to eliminate huge amounts of useless computations. Finally, extensive experiments are performed to examine the efficiency and effectiveness of our proposed techniques.
The method of splitting a plane-wave finite-difference time-domain (SP-FDTD) algorithm is presented for the initiation of plane-wave source in the total-field / scattered-field (TF/SF) formulation of high-order sy...
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The method of splitting a plane-wave finite-difference time-domain (SP-FDTD) algorithm is presented for the initiation of plane-wave source in the total-field / scattered-field (TF/SF) formulation of high-order symplectic finite- difference time-domain (SFDTD) scheme for the first time. By splitting the fields on one-dimensional grid and using the nature of numerical plane-wave in finite-difference time-domain (FDTD), the identical dispersion relation can be obtained and proved between the one-dimensional and three-dimensional grids. An efficient plane-wave source is simulated on one-dimensional grid and a perfect match can be achieved for a plane-wave propagating at any angle forming an integer grid cell ratio. Numerical simulations show that the method is valid for SFDTD and the residual field in SF region is shrinked down to -300 dB.
An edge matching method based on mean shift algorithm is proposed in this paper. According to the mode of seeking ability in mean shift algorithm, a pre-process is presented in the matching process which adjusts the e...
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An edge matching method based on mean shift algorithm is proposed in this paper. According to the mode of seeking ability in mean shift algorithm, a pre-process is presented in the matching process which adjusts the edge information of target and candidate models to their stable states. In addition, the optimizing solutions to the matching process are presented which include of using combined morphological operations in edge extraction, updating target edge information, limiting the iterations of candidate mean shift, and shifting the initial iterating positions of candidate models through the interfering vector. The proposed method and the optimizing solutions can alleviate the influence of noise interference. In addition, the matching method is applied in an improved particle filter tracking framework. The experiment results indicate the close relationship between the value of interfering coefficient and the tracking performance, and show that the proposed method can increase the robustness of matching and efficiently improve the performance of tracking.
With the rapid development of Internet, MANET is becoming a popular network organization. Automatic service discovery plays an important role in the appliance of auto-finding and using the resource in the dynamic netw...
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Infrared images are by nature fuzzy and thus the segmentation of human targets from them is a challenging task. To handle this ambiguity, a new kind of thresholding method using both the spatial information and fuzzin...
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For Petri net models whose legal reachability spaces are non-convex, one cannot optimally control them by the conjunctions of linear constraints. This work proposes a method to find a set of linear constraints such th...
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With the rapid development of service-oriented computing (SOC) and service-oriented architecture (SOA), the number of services is rapidly increasing. How to organize and manage services effectively in repositories to ...
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With the rapid development of service-oriented computing (SOC) and service-oriented architecture (SOA), the number of services is rapidly increasing. How to organize and manage services effectively in repositories to improve the efficiency of service discovery and composition is important. This paper proposes three categorization rules to classify services for a large scale repository to form a relational taxonomy. The service retrieve scope can be drastically narrowed by this taxonomy. Therefore, the efficiency of service discovery and service composition can be greatly improved. We evaluate and compare the performance of the proposed method and other related ones via a publicly available test set, ICEBE05. The experimental results validate the effectiveness and high efficiency of the proposed one.
In this paper, we study multicast capacity for cognitive networks. We consider the cognitive network model consisting of two overlapping ad hoc networks, called the primary ad hoc network (PaN) and secondary ad hoc ne...
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In this paper, we study multicast capacity for cognitive networks. We consider the cognitive network model consisting of two overlapping ad hoc networks, called the primary ad hoc network (PaN) and secondary ad hoc network (SaN), respectively. PaN and SaN operate on the same space and spectrum. For PaN (or SaN, respectively), we assume that primary (or secondary, respectively) nodes are placed according to a Poisson point process of intensity n (or m, respectively) over a unit square region. We randomly choose n s (or m s , respectively) nodes as the sources of multicast sessions in PaN (or SaN, respectively), and for each primary source vp (or secondary source v s , respectively), we pick uniformly at random nd primary nodes (or md secondary nodes, respectively) as the destinations of v p (or v s , respectively). Above all, we assume that PaN can adopt the optimal protocol in terms of the throughput. Our main work is to design the multicast strategy for SaN by which the optimal throughput can be achieved, without any negative impact on the throughput for PaN in order sense. Depending on nd and n, we choose the optimal one for PaN from two strategies called percolation strategy and connectivity strategy, respectively. Subsequently, we design the corresponding throughput-optimal strategy for SaN. We derive the regimes in terms of n, n d , m, and m d in which the upper bounds on multicast capacities for PaN and SaN can be achieved simultaneously. Unicast and broadcast capacities for the cognitive network can be derived by our results as the special cases by letting n d = 1 (or m d = 1) and n d = n - 1 (or m d = m - 1), respectively, which enhances the generality of this work.
It is challenging to schedule time-constrained cluster tools subject to activity time variation. With the help of their Petri net model, a real-time control policy is used to offset the activity time variation. Based ...
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It is challenging to schedule time-constrained cluster tools subject to activity time variation. With the help of their Petri net model, a real-time control policy is used to offset the activity time variation. Based on it, the schedulability conditions and scheduling algorithms are presented for single-arm cluster tools. The schedulability conditions can be analytically checked. Algorithms are developed based on analytical expressions such that it is also computationally efficient. The schedule obtained by the scheduling algorithms together with a real-time control policy forms the real-time schedule. It is optimal in terms of cycle time.
This paper present a geometric method to reconstruct human motion pose from 2D point correspondences obtained from uncalibrated monocular images. The proposed algorithm can handle images with very strong perspective e...
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