331,005 research outputs found
Rough sets theory and uncertainty into information system
This article is focused on rough sets approach to expression of uncertainty into information system. We assume that the data are presented in the decision table and that some attribute values are lost. At first the theoretical background is described and after that, computations on real-life data are presented. In computation we wok with uncertainty coming from missing attribute values
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The effect of missing values using genetic programming on evolvable diagnosis
Medical databases usually contain missing values due the policy of
reducing stress and harm to the patient. In practice missing values has been a
problem mainly due to the necessity to evaluate mathematical equations obtained
by genetic programming. The solution to this problem is to use fill in methods to
estimate the missing values. This paper analyses three fill in methods: (1) attribute
means, (2) conditional means, and (3) random number generation. The methods
are evaluated using sensitivity, specificity, and entropy to explain the exchange in
knowledge of the results. The results are illustrated based on the breast cancer
database. Conditional means produced the best fill in experimental results
Solving Incomplete Datasets in Soft Set Using Supported Sets and Aggregate Values
AbstractThe theory of soft set proposed by Molodtsovin 1999[1]is a new method for handling uncertain data and can be defined as a Boolean-valued information system. Ithas been applied to data analysis and decision support systems based on large datasets. In this paper, it is shown that calculated support value can be used to determine missing attribute value of an object. However, in cases when more than one value is missing, the aggregate values and calculated support values will be used in determining the missing values. By successfully recovering missing attribute values, the integrity of a dataset can still been maintained
Revisiting Initializing Then Refining: An Incomplete and Missing Graph Imputation Network
With the development of various applications, such as social networks and
knowledge graphs, graph data has been ubiquitous in the real world.
Unfortunately, graphs usually suffer from being absent due to
privacy-protecting policies or copyright restrictions during data collection.
The absence of graph data can be roughly categorized into attribute-incomplete
and attribute-missing circumstances. Specifically, attribute-incomplete
indicates that a part of the attribute vectors of all nodes are incomplete,
while attribute-missing indicates that the whole attribute vectors of partial
nodes are missing. Although many efforts have been devoted, none of them is
custom-designed for a common situation where both types of graph data absence
exist simultaneously. To fill this gap, we develop a novel network termed
Revisiting Initializing Then Refining (RITR), where we complete both
attribute-incomplete and attribute-missing samples under the guidance of a
novel initializing-then-refining imputation criterion. Specifically, to
complete attribute-incomplete samples, we first initialize the incomplete
attributes using Gaussian noise before network learning, and then introduce a
structure-attribute consistency constraint to refine incomplete values by
approximating a structure-attribute correlation matrix to a high-order
structural matrix. To complete attribute-missing samples, we first adopt
structure embeddings of attribute-missing samples as the embedding
initialization, and then refine these initial values by adaptively aggregating
the reliable information of attribute-incomplete samples according to a dynamic
affinity structure. To the best of our knowledge, this newly designed method is
the first unsupervised framework dedicated to handling hybrid-absent graphs.
Extensive experiments on four datasets have verified that our methods
consistently outperform existing state-of-the-art competitors
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