The emergence of monitoring applications has precipitated the need for Data Stream Management Systems (DSMSs), which constantly monitor incoming data feeds (through registered continuous queries), in order to detect e...
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The emergence of monitoring applications has precipitated the need for Data Stream Management Systems (DSMSs), which constantly monitor incoming data feeds (through registered continuous queries), in order to detect events of interest. In this article, we examine the problem of how to schedule multiple Continuous Queries (CQs) in a DSMS to optimize different Quality of Service (QoS) metrics. We show that, unlike traditional online systems, scheduling policies in DSMSs that optimize for average response time will be different from policies that optimize for average slowdown, which is a more appropriate metric to use in the presence of a heterogeneous workload. Towards this, we propose policies to optimize for the average-case performance for both metrics. Additionally, we propose a hybrid scheduling policy that strikes a fine balance between performance and fairness, by looking at both the average- and worst-case performance, for both metrics. We also show how our policies can be adaptive enough to handle the inherent dynamic nature of monitoring applications. Furthermore, we discuss how our policies can be efficiently implemented and extended to exploit sharing in optimized multi-query plans and multi-stream CQs. Finally, we experimentally show using real data that our policies consistently outperform currently used ones.
Human cytogenetics is the study of chromosomes (typically at mitotic metaphase). The study of chromosomes has recently become integrated with molecular biology and genomics. Thus, it is an important part of genetics e...
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Human cytogenetics is the study of chromosomes (typically at mitotic metaphase). The study of chromosomes has recently become integrated with molecular biology and genomics. Thus, it is an important part of genetics education. However, it is time consuming to train students and clinical technologists to recognize patterns of G-banded human chromosomes because of the dynamic nature of G-band resolutions in different metaphase spreads. Moreover, there are limited resources to obtain the images of abnormal chromosomes. We present in this paper an advanced version of computer based interactive tutorial program capable of simulating chromosome abnormalities, altering chromosome shapes, and manipulating G-band resolutions for human cytogenetic seduction. By simulating chromosomes using digital image processing and pattern recognition, the versatile software, together with various strategies such as website links and dialogs, will provide students with a virtual learning environment for self-practicing and testing, thus transforming the traditionally dry and ineffective approach into an exciting and efficient learning process. (c) 2012 Elsevier Ireland Ltd. All rights reserved.
Two algorithms are presented for compressing image documents, with a high compression ratio for both colour and monochromatic compound document images. The proposed algorithms apply a new method of segmentation to sep...
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Two algorithms are presented for compressing image documents, with a high compression ratio for both colour and monochromatic compound document images. The proposed algorithms apply a new method of segmentation to separate the text from the image in a compound document in which the text overlaps the background. The segmentation method classifies document images into three planes: the text plane, the background (non-text) plane and the text's colour plane, each of which are processed using different compression techniques. The text plane is compressed using the pattern matching technique, called JB2. Wavelet transform and zerotree coding are used to compress the background plane and the text's colour plane. Assigning bits for different planes yields high-quality compound document images with both a high compression ratio and well presented text. The proposed algorithms greatly outperform two well known image compression methods, JPEG and DjVu, and enable the effective extraction of the text from a complex background, achieving a high compression ratio for compound document images.
A method of data acquisition and data analysis is described in which the performance of Michelson-type interferometers with unequal arms can be made nearly the same as interferometers with equal arms. The method requi...
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A method of data acquisition and data analysis is described in which the performance of Michelson-type interferometers with unequal arms can be made nearly the same as interferometers with equal arms. The method requires a separate readout of the relative phase in each arm, made by interfering the returning beam in each arm with a fraction of the outgoing beam. Instead of throwing away the information from a single arm by subtracting it from that from the other arm, the data in one arm is first used to estimate the laser phase noise and then correct for its effect in the normal differenced interferometer data.
We consider the problem of utilizing a pack of m batteries serving n current demands in electric vehicles. When serving a demand, the current allocation might be split among the batteries in the pack. A battery's ...
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We consider the problem of utilizing a pack of m batteries serving n current demands in electric vehicles. When serving a demand, the current allocation might be split among the batteries in the pack. A battery's life depends on the discharge current used for supplying the requests. Any deviation from the optimal discharge-current is associated with a penalty. Thus, the problem is to serve an online sequence of current requests in a way that minimizes the total penalty associated with the service. We show that the offline problem, for which the sequence of current demands is known in advance, is strongly NP-hard and hard to approximate within an additive gap of omega(m) from the optimum. For the online problem, we present a competitive algorithm associated with the redundant penalty at most m. Finally, we provide a lower bound of 1.5 for the multiplicative competitive ratio of any online algorithm.
This paper deals with the problem of a logistics company that has to serve its customers by first putting the products on pallets and then loading the pallets into trucks. Besides the standard geometric constraints of...
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This paper deals with the problem of a logistics company that has to serve its customers by first putting the products on pallets and then loading the pallets into trucks. Besides the standard geometric constraints of products not overlapping each other and not exceeding the dimensions of pallets and trucks, in this real problem, there are many other constraints, related to the total weight of the load, the maximum weight supported by each axle, and the distribution of the load inside the truck. Although the problem can be decomposed into two phases, pallet loading and truck loading, we have taken a combined approach, building and placing pallets at the same time. For each position in the truck, a pallet is built and tailored for that position according to the constraints of height and weight. We have developed a GRASP algorithm, in which the constructive algorithmis randomized and an improvement phase is added to obtain high-quality solutions. The algorithm has been tested on two sets of real instances with different characteristics, involving up to 44 trucks. The results show that solutions with an optimal or near optimal number of trucks are obtained in very short computing times.
The results of simulating the algorithms developed for noncoherent iterative reception of signals based on highly redundant serial turbo codes and Walsh signal ensembles are presented. It is assumed that transmission ...
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The results of simulating the algorithms developed for noncoherent iterative reception of signals based on highly redundant serial turbo codes and Walsh signal ensembles are presented. It is assumed that transmission is carried out over nonstationary channels.
We introduce algorithms and architectures for automatic spike detection and alignment that are designed for low power. Some of the algorithms are based on principal component analysis (PCA). Others employ a novel inte...
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We introduce algorithms and architectures for automatic spike detection and alignment that are designed for low power. Some of the algorithms are based on principal component analysis (PCA). Others employ a novel integral transform analysis and achieve 99% of the precision of a PCA detector, while requiring only 0.05% of the computational complexity. The algorithms execute autonomously, but require off-line training and setting of computational parameters. We employ pre-recorded neuronal signals to evaluate the accuracy of the proposed algorithms and architectures: the recorded data are processed by a standard PCA spike detection and alignment software algorithm, as well as by the several hardware algorithms, and the outcomes are compared.
The minimal model structure detection (MMSD) problem in nonlinear dynamic system identification is formulated as a search for the optimal orthogonalization path. While an exhaustive search for a model with 20 candidat...
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The minimal model structure detection (MMSD) problem in nonlinear dynamic system identification is formulated as a search for the optimal orthogonalization path. While an exhaustive search for a model with 20 candidate terms would involve 2.43 x 10(18) possible paths, it is shown that this can typically be reduced to 2 x 10(3) by augmenting the orthogonal estimation algorithm with genetic search procedures. The MMSD algorithm provides the first practical solution for optimal structure detection in NARMAX modelling, training neural networks and fuzzy systems modelling. Based on the MMSD algorithm, a refined forward regression orthogonal (RFRO) algorithm is developed. The RFRO algorithm initially detects a parsimonious model structure using the forward regression orthogonal algorithm and then refines the model structure by applying the MMSD algorithm to the reduced model term set. The RFRO algorithm cannot guarantee to find the minimal model structure, but it is computationally more efficient than the MMSD algorithm and can find a smaller model than the forward regression orthogonal algorithm.
Software for analyzing pseudotranslational sublattices (PTSs) in crystal structures is described. This software makes it possible to enumerate triads of reflections, sort them out with respect to different characteris...
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Software for analyzing pseudotranslational sublattices (PTSs) in crystal structures is described. This software makes it possible to enumerate triads of reflections, sort them out with respect to different characteristics, calculate linear and angular subcell parameters, and express the sublattice vectors in terms of the initial lattice vectors. The solution to the most widespread problems is illustrated by the example of the well-known [Ru(NH(3))(6)]Cl(3) and [CuL](NO(3))(ReO(4)) crystal structures (L is 4,6,6-trimethyl-1,9-diamino-3,7-diazanon-3-en) and the structure of mineral iltisite, which is still unknown. In all cases we observed a tendency of crystal structures to have a higher symmetry, which was noted by Academician Belov in his time. "A material that in fact crystallizes in a lower system is nevertheless rather close (in its crystalline form) to numerical relations characteristic of a higher system." (Belov [1, p. 227]).
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