A new approach to the integration of the results of several tools aimed at solving a single problem is considered. The approach is illustrated by the example of solving the authentication task for signature dynamics b...
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A new approach to the integration of the results of several tools aimed at solving a single problem is considered. The approach is illustrated by the example of solving the authentication task for signature dynamics based on the naive Bayesian classifier and the neural network. The approach guarantees results not worse than any of the classifiers separately from the point of view of a monotonous combination of the probabilities of errors of the first and second kind. The obtained results can be applied in the construction of a multifactor authentication system.
Compression is widely exploited in retrieval systems, such as search engines and text databases, to lower both retrieval costs and system latency. In particular, compression of repositories can reduce storage requirem...
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ISBN:
(纸本)9781450325981
Compression is widely exploited in retrieval systems, such as search engines and text databases, to lower both retrieval costs and system latency. In particular, compression of repositories can reduce storage requirements and fetch times, while improving caching. One of the most effective techniques is relative Lempel-Ziv, RLZ, in which a RAM-resident dictionary encodes the collection. With RLZ, a specified document can be decoded independently and extremely fast, while maintaining a high compression ratio. For terabyte-scale collections, this dictionary need only be a fraction of a per cent of the original data size. However, as originally described, RLZ uses a static dictionary, against which encoding of new data may be inefficient. An obvious alternative is to generate a new dictionary solely from the new data. However, this approach may not be scalable because the combined RAM-resident dictionary will grow in proportion to the collection. In this paper, we describe effective techniques for extending the original dictionary to manage new data. With these techniques, a new auxiliary dictionary, relatively limited in size, is created by interrogating the original dictionary with the new data. Then, to compress this new data, we combine the auxiliary dictionary with some parts of the original dictionary (the latter in fact encoded as pointers into that original dictionary) to form a second dictionary. Our results show that excellent compression is available with only small auxiliary dictionaries, so that RLZ can feasibly transmit and store large, growing collections. Copyright 2014 ACM.
Relative Lempel-Ziv (RLZ) compression has been shown to be effective for compression of large text repositories. It provides high compression ratios with extremely fast atomic decompression of individual documents. Ho...
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In data warehousing, ETL (Extract, Transform, and Load) processes take charge of extracting the data from data sources that would be contained in the data warehouse. Due to their relevance, the quality of these proces...
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ISBN:
(纸本)9781605588162
In data warehousing, ETL (Extract, Transform, and Load) processes take charge of extracting the data from data sources that would be contained in the data warehouse. Due to their relevance, the quality of these processes should be formally assessed since the early stages of development, in order to avoid making bad decisions as a result of incorrect data. In this paper, a set of measures to evaluate the structural complexity of ETL process models at conceptual level is presented. Moreover, this study is accompanied by four experiments whose aim is the empirical validation of the proposed measures. The main advantage of this approach is the early evaluation of ETL process models. This early evaluation support designers in their maintenance tasks. This proposal is based on UML (Unifield Modeling Language) activity diagrams for modeling ETL processes and the adoption of the FMESP (Framework for the Modeling and Evaluation of Software Processes) framework. Copyright 2009 ACM.
Data warehouses (DW) integrate different data sources in order to give a multidimensional view of them to the decision-maker. To this aim, the ETL (Extraction, Transformation and Load) processes are responsible for ex...
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ISBN:
(纸本)9781605588018
Data warehouses (DW) integrate different data sources in order to give a multidimensional view of them to the decision-maker. To this aim, the ETL (Extraction, Transformation and Load) processes are responsible for extracting data from heterogeneous operational data sources, their transformation (conversion, cleaning, standardization, etc.), and its load in the DW. In recent years, several conceptual modeling approaches have been proposed for designing ETL processes. Although these approaches are very useful for documenting ETL processes and supporting the designer tasks, these proposals fail to give mechanisms to carry out an automatic code generation stage. Such a stage should be required to both avoid fails and save development time in the implementation of complex ETL process. Therefore, in this paper we define an approach for the automatic code generation of ETL processes. To this aim, we align the modeling of ETL processes in DW with MDA (Model Driven Architecture) by formally defining a set of QVT (Query, View, Transformation) transformations. Copyright 2009 ACM.
The paper considers the condition and comparison of representation on the Internet of both unaffected and reformed research institutions, in order to form a methodology for assessing the possibility of adequate and ti...
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The maximal guaranteed result in a hierarchical game with an undetermined factor is found in the class of strategies with feedback. The stability of the problem under consideration concerning perturbations of the payo...
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The paper discusses the methods that may be used to set up a science-based digital ecosystem for agriculture;these methods are based on the ideas proposed by A. Kitov and Academician V. Glushkov about a national autom...
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Thepaper deals with a formalized description of a computer-aided crop rotation engineering system based on a mathematical crop system optimization model implemented in the digital platform for industry management that...
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The application of mobile robots is very important in environments that are dangerous or inappropriate for human life. One of the problems arising for the mobile robot when targeting point within the indoor applicatio...
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