13,954 research outputs found
SQL Query Completion for Data Exploration
Within the big data tsunami, relational databases and SQL are still there and
remain mandatory in most of cases for accessing data. On the one hand, SQL is
easy-to-use by non specialists and allows to identify pertinent initial data at
the very beginning of the data exploration process. On the other hand, it is
not always so easy to formulate SQL queries: nowadays, it is more and more
frequent to have several databases available for one application domain, some
of them with hundreds of tables and/or attributes. Identifying the pertinent
conditions to select the desired data, or even identifying relevant attributes
is far from trivial. To make it easier to write SQL queries, we propose the
notion of SQL query completion: given a query, it suggests additional
conditions to be added to its WHERE clause. This completion is semantic, as it
relies on the data from the database, unlike current completion tools that are
mostly syntactic. Since the process can be repeated over and over again --
until the data analyst reaches her data of interest --, SQL query completion
facilitates the exploration of databases. SQL query completion has been
implemented in a SQL editor on top of a database management system. For the
evaluation, two questions need to be studied: first, does the completion speed
up the writing of SQL queries? Second , is the completion easily adopted by
users? A thorough experiment has been conducted on a group of 70 computer
science students divided in two groups (one with the completion and the other
one without) to answer those questions. The results are positive and very
promising
Information Extraction, Data Integration, and Uncertain Data Management: The State of The Art
Information Extraction, data Integration, and uncertain data management are different areas of research that got vast focus in the last two decades. Many researches tackled those areas of research individually. However, information extraction systems should have integrated with data integration methods to make use of the extracted information. Handling uncertainty in extraction and integration process is an important issue to enhance the quality of the data in such integrated systems. This article presents the state of the art of the mentioned areas of research and shows the common grounds and how to integrate information extraction and data integration under uncertainty management cover
Integrating Economic Knowledge in Data Mining Algorithms
The assessment of knowledge derived from databases depends on many factors. Decision makers often need to convince others about the correctness and effectiveness of knowledge induced from data.The current data mining techniques do not contribute much to this process of persuasion.Part of this limitation can be removed by integrating knowledge from experts in the field, encoded in some accessible way, with knowledge derived form patterns stored in the database.In this paper we will in particular discuss methods for implementing monotonicity constraints in economic decision problems.This prior knowledge is combined with data mining algorithms based on decision trees and neural networks.The method is illustrated in a hedonic price model.knowledge;neural network;data mining;decision trees
Data exploration systems for databases
Data exploration systems apply machine learning techniques, multivariate statistical methods, information theory, and database theory to databases to identify significant relationships among the data and summarize information. The result of applying data exploration systems should be a better understanding of the structure of the data and a perspective of the data enabling an analyst to form hypotheses for interpreting the data. This paper argues that data exploration systems need a minimum amount of domain knowledge to guide both the statistical strategy and the interpretation of the resulting patterns discovered by these systems
Efficient algorithms for decision tree cross-validation
Cross-validation is a useful and generally applicable technique often
employed in machine learning, including decision tree induction. An important
disadvantage of straightforward implementation of the technique is its
computational overhead. In this paper we show that, for decision trees, the
computational overhead of cross-validation can be reduced significantly by
integrating the cross-validation with the normal decision tree induction
process. We discuss how existing decision tree algorithms can be adapted to
this aim, and provide an analysis of the speedups these adaptations may yield.
The analysis is supported by experimental results.Comment: 9 pages, 6 figures.
http://www.cs.kuleuven.ac.be/cgi-bin-dtai/publ_info.pl?id=3478
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Multi-class protein fold classification using a new ensemble machine learning approach.
Protein structure classification represents an important process in understanding the associations
between sequence and structure as well as possible functional and evolutionary relationships.
Recent structural genomics initiatives and other high-throughput experiments have populated the
biological databases at a rapid pace. The amount of structural data has made traditional methods
such as manual inspection of the protein structure become impossible. Machine learning has been
widely applied to bioinformatics and has gained a lot of success in this research area. This work
proposes a novel ensemble machine learning method that improves the coverage of the classifiers
under the multi-class imbalanced sample sets by integrating knowledge induced from different base
classifiers, and we illustrate this idea in classifying multi-class SCOP protein fold data. We have
compared our approach with PART and show that our method improves the sensitivity of the
classifier in protein fold classification. Furthermore, we have extended this method to learning over
multiple data types, preserving the independence of their corresponding data sources, and show
that our new approach performs at least as well as the traditional technique over a single joined
data source. These experimental results are encouraging, and can be applied to other bioinformatics
problems similarly characterised by multi-class imbalanced data sets held in multiple data
sources
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