Search results for "Data type"
showing 10 items of 1183 documents
A novel evaluation model for hybrid power system based on vague set and Dempster-Shafer evidence theory
2012
Published version of an article from the journal: Mathematical Problems in Engineering. Also available from the publisher:http://dx.doi.org/10.1155/2012/784389 Because clean energy and traditional energy have different advantages and disadvantages, it is of great significance to evaluate comprehensive benefits for hybrid power systems. Based on thorough analysis of important characters on hybrid power systems, an index system including security, economic benefit, environmental benefit, and social benefit is established in this paper. Due to advantages of processing abundant uncertain and fuzzy information, vague set is used to determine the decision matrix. Convert vague decision matrix to …
Evaluation of the effect of chance correlations on variable selection using Partial Least Squares -Discriminant Analysis
2013
Variable subset selection is often mandatory in high throughput metabolomics and proteomics. However, depending on the variable to sample ratio there is a significant susceptibility of variable selection towards chance correlations. The evaluation of the predictive capabilities of PLSDA models estimated by cross-validation after feature selection provides overly optimistic results if the selection is performed on the entire set and no external validation set is available. In this work, a simulation of the statistical null hypothesis is proposed to test whether the discrimination capability of a PLSDA model after variable selection estimated by cross-validation is statistically higher than t…
A method for determining the position and size of optimal sequence regions for phylogenetic analysis.
1995
The availability of fast and accurate sequencing procedures along with the use of PCR has led to a proliferation of studies of variability at the molecular level in populations. Nevertheless, it is often impractical to examine long genomic stretches and a large number of individuals at the same time. In order to optimize this kind of study, we suggest a heuristic procedure for detection of the shortest region whose informational content can be considered sufficient for significant phylogenetic reconstruction. The method is based on the comparison of the pairwise genetic distances obtained from a set of sequences of reference to those obtained for different windows of variable size and posit…
A graph colouring model for assigning a heterogeneous workforce to a given schedule
1996
Abstract We analyze a heterogeneous workforce assignment problem in which the minimum number of workers required to carry out a machine load plan is calculated. The problem is formulated as a restricted vertex colouring problem and a branch and bound algorithm is presented. The special characteristics of the graph to be coloured allow an efficient implementation of the branch and bound. Computational results show that the algorithm can solve problems of 50 activities, 5, 10 and 15 machines and between 2 to 15 different types of workers in just a few seconds.
The PAPIA system
1991
In 1983 an Italian research program was begun for the design, simulation and construction of a multiprocessor image processing system. After a first phase devoted to the comparison of suggested and existing systems and to the definition of a set of benchmarks, a new system was defined. The structure of this new system is introduced here: it is based on a fine-grained pyramid of processors built up by means of a pyramidal cell implemented on a VLSI multiprocessor chip. The peculiarities and the capabilities of the processing element are highlighted. The complete hardware and software system has been fully designed and is described. A first working prototype has been built and is now operatio…
Visual dynamic environment for distributed systems
2002
Algorithms, based on information fusion, are often embodied in visual perception systems. Distributed architectures have been recently proposed to perform integrated computation. The complexity of distributed systems regards both their design, and the software environment to develop applications. Visual and iconic programming style intends to provide expressive tools to implement, to debug, and to execute programs in distributed environment. Multi-layers graphs languages seem suitable to handle such complexity. This paper describes the design of a visual dynamic environment (VDE), which is based on a graph-grammar. A new class of dynamic visual interfaces is also introduced, and its propert…
Fillets:Cues for connections in Focus+Context views of graph-like diagrams
2003
We apply fillets-smoothing of sharp angles at the joints-between the connections and nodes of graph-like diagrams. In situations where the graph layout is constrained, e.g. Focus+Context views or views where the coordinates of the nodes are informative, fillets can clarify the relationships considerably without altering the layout. A visual search experiment supports our hypothesis that with fillets it is considerably easier to perceive node-connection structures. We discuss algorithms with different tradeoffs for flexibility and performance for rendering these connections in a single pass using OpenGL.
Conceptual graph operations for formal visual reasoning in the medical domain
2014
International audience; Objective - Conceptual graphs (CGs) are used to represent clinical guidelines because they support visual reasoning with a logical background, making them a potentially valuable representation for guidelines.Materials and methods - Conceptual graph formalism has an essential and basic component: a formal vocabulary that drives all of the other mechanisms, notably specialization and projection. The graph's theoretical operations, such as projection, rules, derivation, constraints, probabilities and uncertainty, support diagrammatic reasoning.Results - A conceptual graph's graphical user interface includes a multilingual vocabulary management, some query and decision-m…
A practical solution to the problem of automatic part-of-speech induction from text
2005
The problem of part-of-speech induction from text involves two aspects: Firstly, a set of word classes is to be derived automatically. Secondly, each word of a vocabulary is to be assigned to one or several of these word classes. In this paper we present a method that solves both problems with good accuracy. Our approach adopts a mixture of statistical methods that have been successfully applied in word sense induction. Its main advantage over previous attempts is that it reduces the syntactic space to only the most important dimensions, thereby almost eliminating the otherwise omnipresent problem of data sparseness.
Pseudodifferential operators of Beurling type and the wave front set
2008
AbstractWe investigate the action of pseudodifferential operators of Beurling type on the wave front sets. More precisely, we show that these operators are microlocal, that is, preserve or reduce wave front sets. Some consequences on micro-hypoellipticity are derived.