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A Structured Query Language extension uses an estimator module to evaluate quality profiles that rate the accuracy and completeness of query results. Users receive information that matches their defined quality constraints and better serves their data needs.
Nowadays, datasets grow enormously both in size and complexity. One of the key issues confronted by large-scale dataset analysis is how to adapt systems to new, unprecedented query loads. Existing systems nail down the data organization scheme once and for all at the beginning of the system design, thus inevitably will see the performance goes down when user requirements change. In this paper, we...
Earth and environmental scientists collect and use a wide range of observational data. This data often exhibits high structural and semantic heterogeneity due to the variety of data collected and the ways in which observational datasets are structured in practice. However, to address questions at broad temporal, geographic, and biological scales, researchers often need to access and combine data from...
Wheat organs database provides background data support and data validation in various studies of wheat growth virtual visualization. This paper has discussed data modeling method of wheat organ configuration, on this foundation we have designed and realized the wheat organ configuration data management system. Through organ configuration data structure design, wheat organ library model is built; through...
Businesses of all sizes and in different industries, as well as government agencies, are finding that they can realize significant benefits by implementing a data warehouse. A data warehouse provides the base for the powerful data analysis techniques that are available today such as data mining and multidimensional analysis, as well as the more traditional query and reporting. Having an enterprise...
Uncertain and imprecise datasets are more and more characterizing actual database applications. These kind of data are likely to be captured by so-called probabilistic data models, which are attracting a great deal of interest from a large community of database researchers. Effectively and efficiently computing OLAP data cubes over probabilistic data is a relevant research challenge that naturally...
Using data cube to analysis historical fact data online more faster than Ad-Hoc queries, but it need very large external storage. In DSMS (Data Stream Management System), due to capacity of memory is much smaller than disk, we meet even more problem in analyzing stream data by in-memory StreamCube. So, we compress StreamCube to gain more information about stream data in certain storage. We implement...
With advances in sensor devices and networking technologies, it is expected that future networks will contain immense numbers of sensors that are capturing time-varying data. It is necessary to process queries over the data for analysis and to store the data for later use. For querying the data, data disorder is a common problem. Existing approaches use buffers to recover the order but there are problems...
Processing multi-extreme value queries efficiently over data streams is important for data analysis in real-time environment. Cost-efficient processing of continuous extreme values queries over sliding windows, especially about resource sharing, is considered. Firstly, an effective storage structure to minimize the number of elements to be kept for queries is given. We prove the average the cardinality...
Data Integration refers to the problem of combining data residing at homogeneous, autonomous, and heterogeneous data sources, and providing users with a unified global schema. Users pose their queries in terms of this unified global schema. Data integration system allows users to perceive the entire collection as a single source, query it transparently, and receive a single and unambiguous answer...
Range sum queries are fundamental part of modern data analysis application. But traditional query algorithms can not be applied on data stream, which is an unbounded sequence of data elements generated at a rapid rate. In this paper, we propose a novel approach for computing range sum from data streams based on wavelet sliding window model. The basic idea is to divide sliding window into equally-sized...
Skyline computation has many applications including multi-criteria decision making. In this paper, we study the problem of efficient processing of continuous skyline queries over sliding windows on uncertain data elements regarding given probability thresholds. We first characterize what kind of elements we need to keep in our query computation. Then we show the size of dynamically maintained candidate...
Data analysis tasks at an Ocean Observatory require integrative and and domain-specialized use of database, workflow, visualization systems. We describe a platform to support these tasks developed as part of the cyberinfrastructure at the NSF Science and Technology Center for Coastal Margin Observation and Prediction integrating a provenance-aware workflow system, 3D visualization, and a remote query...
Provenance is essential in scientific experiments. It contains information that is key to preserving the data and to determine it's quality and authorship. In complex experiments and analyses, where multiple tools are used to derive data products, provenance captured by these tools must be combined in order to determine the complete lineage of the derived products. We propose a mediator-based architecture...
Network streaming data are the network traffic records coming from high-speed network links. They arrive continually and their volumes are huge. The key to analysis of network streaming data is to design a smaller yet well organized data subset to glean the most important information for quickly answering a specific type of query. In this paper, we propose a threshold sampling algorithm for network...
On-line data stream mining has attracted much research interest, but systems that can be used as a workbench for online mining have not been researched, since they pose many difficult research challenges. The proposed system addresses these challenges by an architecture based on three main technical advances, (i) introduction of new constructs and synoptic data structures whereby complex KDD queries...
The speed of data retrieval qualitatively affects how analysts visually explore and analyze their data. To ensure smooth interactions in massive time series datasets, one needs to address the challenges of computing adhoc queries, distributing query load, and hiding system latency. In this paper, we present ATLAS, a visualization tool for temporal data that addresses these issues using a combination...
Aggregate measures summarizing subsets of data are valuable in exploratory analysis and decision support, especially when dependent aggregations can be easily specified and computed. A novel class of queries, called composite subset measures, was previously introduced to allow correlated aggregate queries to be easily expressed. This paper considers how to evaluate composite subset measure queries...
The management of privacy and security in the context of data stream management systems (DSMS) remains largely an unaddressed problem to date. Unlike in traditional DBMSs where access control policies are persistently stored on the server and tend to remain stable, in streaming applications the contexts and with them the access control policies on the real-time data may rapidly change. A person entering...
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