Search results for "methodologie"
showing 10 items of 2141 documents
Fast Computation by Subdivision of Multidimensional Splines and Their Applications
2016
We present theory and algorithms for fast explicit computations of uni- and multi-dimensional periodic splines of arbitrary order at triadic rational points and of splines of even order at diadic rational points. The algorithms use the forward and the inverse Fast Fourier transform (FFT). The implementation is as fast as FFT computation. The algorithms are based on binary and ternary subdivision of splines. Interpolating and smoothing splines are used for a sample rate convertor such as resolution upsampling of discrete-time signals and digital images and restoration of decimated images that were contaminated by noise. The performance of the rate conversion based spline is compared with the…
ON SOME GENERALIZATION OF SMOOTHING PROBLEMS
2015
The paper deals with the generalized smoothing problem in abstract Hilbert spaces. This generalized problem involves particular cases such as the interpolating problem, the smoothing problem with weights, the smoothing problem with obstacles, the problem on splines in convex sets and others. The theorem on the existence and characterization of a solution of the generalized problem is proved. It is shown how the theorem gives already known theorems in special cases as well as some new results.
Large-scale nonlinear dimensionality reduction for network intrusion detection
2017
International audience; Network intrusion detection (NID) is a complex classification problem. In this paper, we combine classification with recent and scalable nonlinear dimensionality reduction (NLDR) methods. Classification and DR are not necessarily adversarial, provided adequate cluster magnification occurring in NLDR methods like $t$-SNE: DR mitigates the curse of dimensionality, while cluster magnification can maintain class separability. We demonstrate experimentally the effectiveness of the approach by analyzing and comparing results on the big KDD99 dataset, using both NLDR quality assessment and classification rate for SVMs and random forests. Since data involves features of mixe…
Guaranteed error bounds for linear algebra problems and a class of Picard-Lindelöf iteration methods
2012
This study focuses on iteration methods based on the Banach fixed point theorem and a posteriori error estimates of Ostrowski. Their application for systems of linear simultaneous equations, bounded linear operators, as well as integral and differential equations is considered. The study presents a new version of the Picard–Lindelöf method for ordinary differential equations (ODEs) supplied with guaranteed and explicitly computable upper bounds of the approximation error. The estimates derived in the thesis take into account interpolation and integration errors and, therefore, provide objective information on the accuracy of computed approximations.
DOCUMENT MANAGEMENT USING CLUSTERING ALGORITHMS
2015
Document management systems are complex systems, which offer services as storage, versioning, metadata, security, as well as indexing and retrieval capabilities. Large numbers of documents could be automatically grouped into classes of documents, which contain similar information. Therefor we propose to use clustering methods in order to group the documents. Clustering is an important process in text mining used for groping documents based on their contents in order to extract knowledge. In this paper we will present some requirements for clustering algorithms for a document management system
Interpretation of journalistic photographs as an instrument of visual literacy education
2016
Images are produced, used and distributed on an enormous scale. However, the skills of understanding, interpreting and using images as well as thinking and learning in terms of images are taken for granted, and thus, they are not sufficiently taught and developed, especially in higher education. The need for introducing visual literacy into the curriculum was identified in late 1960s, but no concrete guidelines have followed. This study proposes to apply interpretation of journalistic photographs as an instrument of visual literacy education. The main focus is on the image interpretation process and the kinds of meanings viewers apply to a photograph in the interpretation process. In each o…
Verkkoproosa : tutkimus dialogisesta kirjoittamisesta
2007
This theoretical work scrutinizes poetical aspects of writing in the web (blogs, chat, forums). The practice of writing called web prose use the elements of speech and textualize it. This brings web prose near the tradition of literature, not as art, but as style of prose writing. By using H-G Gadamer`s hermeneutics, philosophy of conversation and poetics, I ask how the tradition of writing comes in to the web. Web is scrutinized from the aspects of poetics, dialogue and publicity. The work examines language and genre from the approach of the writing studies. Dialoque has an important function also in the web prose, when writing is getting closer to conversation. At last part I ask what cha…
Hybrid vibration signal monitoring approach for rolling element bearings
2019
New approach to identify different lifetime stages of rolling element bearings, to improve early bearing fault detection, is presented. We extract characteristic features from vibration signals generated by rolling element bearings. This data is first pre-labelled with an unsupervised clustering method. Then, supervised methods are used to improve the labelling. Moreover, we assess feature importance with each classifier. From the practical point of view, the classifiers are compared on how early emergence of a bearing fault is being suggested. The results show that all of the classifiers are usable for bearing fault detection and the importance of the features was consistent. peerReviewed
HIGH QUALITY TEXTURE MAPPING PROCESS AIMED AT THE OPTIMIZATION OF 3D STRUCTURED LIGHT MODELS
2019
Abstract. This article presents the evaluation of a pipeline to develop a high-quality texture mapping implementation which makes it possible to carry out a semantic high-quality 3D textured model. Due to geometric errors such as camera parameters or limited image resolution or varying environmental parameters, the calculation of a surface texture from 2D images could present several color errors. And, sometimes, it needs adjustments to the RGB or lightness information on a defined part of the texture. The texture mapping procedure is composed of mesh parameterization, mesh partitioning, mesh segmentation unwraps, UV map and projection of island, UV layout optimization, mesh packing and mes…
HYPERSPECTRAL REFLECTANCE SIGNATURES AND POINT CLOUDS FOR PRECISION AGRICULTURE BY LIGHT WEIGHT UAV IMAGING SYSTEM
2018
Abstract. The objective of this investigation was to study the use of a new type of a low-weight unmanned aerial vehicle (UAV) imaging system in the precision agriculture. The system consists of a novel Fabry-Perot interferometer based hyperspectral camera and a high-resolution small-format consumer camera. The sensors provide stereoscopic imagery in a 2D frame-format and they both weigh less than 500 g. A processing chain was developed for the production of high density point clouds and hyperspectral reflectance image mosaics (reflectance signatures), which are used as inputs in the agricultural application. We demonstrate the use of this new technology in the biomass estimation process, w…