National Institute of Telecommunication

Warsaw, Poland

National Institute of Telecommunication

Warsaw, Poland

Time filter

Source Type

Batalla J.M.,Seidor S.A. | Batalla J.M.,National Institute of Telecommunication | Mavromoustakis C.X.,University of Nicosia | Mastorakis G.,Technological Educational Institute of Crete | And 2 more authors.
Journal of Supercomputing | Year: 2016

Critical applications which need to deliver multimedia through the Internet, may achieve the required quality of service thanks to the Content-Aware Networks (CAN). The key element of CAN is an efficient decision algorithm responsible for the selection of the best content source and routing paths for content delivery. This paper proposes a two-phase decision algorithm, exploiting the Evolutionary Multiobjective Optimization (EMO) approach. It allows to consider valid information in different time scales, adapting decision-maker to the evolving network and server conditions as well as to get the optimal solution in different shapes of Pareto front. The simulation experiments performed in a large-scale network model, confirm the effectiveness of the proposed two-phase EMO algorithm, comparing to other multi-criteria decision algorithms used in CAN. © 2016 The Author(s)


Aragao M.V.C.,National Institute of Telecommunication | Frigieri E.P.,National Institute of Telecommunication | Ynoguti C.A.,National Institute of Telecommunication | Paiva A.P.,Federal University of Itajubá
Expert Systems with Applications | Year: 2016

Over the last few decades, the advent of telecommunication systems has allowed a growing exchange of electronic messages around the world. Unfortunately, irrelevant and/or unsolicited content corresponds to the majority of this volume of data, and to decide whether to keep or discard each message is a known challenge in the context of machine learning. This paper proposes an anti-spam filtering approach base on linguistic techniques. The real effect of each system parameter is evaluated through design factorial analysis using two different classifiers: first using Support Vector Machine (SVM) and second applying Naive Bayesian (NB) classification. This analysis is detailed and discussed providing a step-by-step guide for developers and users of anti-spam filters. Based on different system metrics, multi-objective optimization is applied in order to obtain the optimal filter setup. Evaluation of anti-spam filter under optimal configuration showed that SVM-based system achieved an accuracy performance above 98% whereas the NB-based system reached 87%. Results also reveal that linguistic techniques are relevant for the NB classifier but do not contribute to improve the SVM-based system performance. © 2016 Elsevier Ltd


Frigieri E.P.,Federal University of Itajubá | Brito T.G.,Federal University of Itajubá | Ynoguti C.A.,National Institute of Telecommunication | Paiva A.P.,Federal University of Itajubá | And 2 more authors.
International Journal of Advanced Manufacturing Technology | Year: 2016

The main objective in machining processes is to produce a high-quality surface finish which, however, can be measured only at the end of the machining cycle. A more preferable method would be to monitor the quality during the cycle, what result a real-time, low-cost, and accurate monitoring method that can dynamically adjust the machining parameters and keep the target surface finish. Motivated by this premise, results of investigation on the relationship between emitted sound signal and surface finish during turning process are reported in this paper. Through experiments with AISI 52100 hardened steel, this work shows that such a correlation does exist presenting strong evidences that Mel-Frequency Cepstral Coefficients, extracted from sound energy, can detect different surface roughness levels, what makes it a promising feature for real-time process quality monitoring methods. © 2016 Springer-Verlag London


Welikow K.,Warsaw University of Technology | Gdula P.,Warsaw University of Technology | Gdula P.,National Institute of Telecommunication | Szczepanski P.,Warsaw University of Technology | And 4 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

This work is focused on the selected aspects of designing of microstructured POF (mPOF) with relatively large core, limited modal dispersion and improved resistance to bending losses, discussed in the context of its possible application in FTTH systems. The calculations confirmed the possibility of effective controlling both, the propagation and macrobending losses, as well as manipulation on the number of modes and modal area. The careful theoretical analysis allowed to design a series of geometries supporting the propagation of limited number of modes and, simultaneously, relatively large mode area together with limited bending losses. © 2012 SPIE.


Granat J.,National Institute of Telecommunication | Klimasara E.,National Institute of Telecommunication | Moacicka A.,National Institute of Telecommunication | Paczuska S.,National Institute of Telecommunication | And 2 more authors.
Studies in Computational Intelligence | Year: 2013

The paper discusses the role of tacit knowledge (including emotive and intuitive knowledge) in cognitive processes, recalls an evolutionary theory of intuition, academic and organizational knowledge creation processes, describes diverse cognitive processes in a research group, but especially concentrates on individual hermeneutic processes and processes of knowledge exchange while distinguishing their hermeneutic and semantic role. The functionality and main features of the PrOnto system are shortly recalled, and the relation of changes in individualized ontological profile of the user to her/his hermeneutical perspective is postulated. An interpretation of such changes for both hermeneutic and semantic aspects of knowledge exchange is presented. Conclusions and future research problems are outlined. © 2013 Springer-Verlag Berlin Heidelberg.


Zigh E.,National Institute of Telecommunication | Belbachir M.F.,Oran University of Science and Technology - Mohamed Boudiaf | Kadiri M.,University of Mascara
Proceedings of 2015 International Conference on Electrical and Information Technologies, ICEIT 2015 | Year: 2015

Buildings extraction is extremely important for many applications such as natural disasters and crisis management, urban planning and development, or telecommunication, etc. However, extracting automatically buildings from multispectral urban satellite images isn't an easy task because, in one hand, it often needs other technological expensive resources such as Lidar data. In the other hand, the urban environment is becoming more complex and heterogeneous in colours and shapes of its components. From that, we propose in this paper a fuzzy-morphological method applied on urban satellite images delivered alone. It is an hybrid method based on a combination of spectral and spatial pixel information to overcome the limitation of traditional methods. The spectral information is treated using fuzzy logic concept and a spatial one using morphological operations. It can be considered as a thresholding method which achieves the aimed goal according two steps: at first, it does a soft clustering by attributing each pixel to a cluster according to a membership degree, after that, it keeps only interesting regions 'buildings'. Promising buildings extraction results are presented and to show even more the effectiveness of proposed approach, it has been compared to two other thresholding methods. © 2015 IEEE.


Ribeiro F.M.,National Institute of Telecommunication | Costa T.S.,National Institute of Telecommunication | Baratella A.,National Institute of Telecommunication | Santos M.M.,Federal Technological University of Paraná | Stevan S.,Federal Technological University of Paraná
International Journal of Innovative Computing, Information and Control | Year: 2014

Industrial Ethernet has appeared in order to support the industrial communication for distributed applications in easy and reliable way to field devices. The Ethernet network used in offices and other places does not provide the requirements demanded for industrial environment, real-time, flexibility, scalability and maintainability without dangerous changes on the network topology. This article shows the comparative analysis of three industrial Ethernet networks spreadly employed in the market for industrial automation. It will be showed communication characteristic, configurations and applications considering standard as PROFINET, Ethernet/IP and HSE networks. It is accomplished with a comprehensive analysis among these networks showing common characteristics to these standards. After this approach, it will be explained a case study with simulations that will be done using the information obtained to analyze the performance and possible improvements in the system previously studied. © 2014, IJICIC Editorial Office, Inc. All rights reserved.


Welikow K.,Warsaw University of Technology | Gdula P.,Warsaw University of Technology | Gdula P.,National Institute of Telecommunication | Piramidowicz R.,Warsaw University of Technology
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

This work is aimed at implementation and practical verification of effective index approach applicability to microstructured fibers modeling. In particular, the Effective Index Method, both in scalar and fully vectorial form, is presented and discussed with respect of its potential applications for fast and accurate modeling of chromatic dispersion of index guiding microstructured fibers. The developed models, implemented in Matlab environment, allow visualization of the dispersion profiles of index guiding microstructured fibers with hexagonal lattice. To verify accuracy and define the applicability range of developed models, the results of modeling were confronted with the sparse experimental data, reported up to now in scientific papers. The satisfying agreement between numerical and measured results has been obtained, confirming the accuracy of developed model and its applicability to fast analysis and designing of microstructured fibers with dielectric core. © 2011 SPIE.


Gdula P.,Warsaw University of Technology | Gdula P.,National Institute of Telecommunication | Welikow K.,Warsaw University of Technology | Szczepanski P.,Warsaw University of Technology | And 4 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

This paper is focused on selected aspects of designing and modeling of transmission parameters of plastic optical fibers (POFs), considered in the context of their potential applications in optical access networks and, specifically, in Fiber-To- The-Home (FTTH) systems. The survey of state-of-the-art solutions is presented and possibility of improving transmission properties of POFs by microstructurization is discussed on the basis of the first results of numerical modeling. In particular, the microstructured POF was designed supporting propagation of limited number of modes while keeping relatively large mode area and, simultaneously, significantly lowered bending losses. © 2011 SPIE.


Prabakaran K.,Anna University | Chandrasekaran R.,Government of Tamilnadu | Mahadevan G.,Anna University | Jaroszewicz Z.,Institute of Applied Optics | And 3 more authors.
Optics Communications | Year: 2013

Focusing properties of the generalized cylindrical vector beam with high numerical aperture lens axicon system is investigated theoretically by vector diffraction theory. Results show that intensity distribution in the focal region can be tailored considerably by appropriately adjusting the polarization angle. Peak-centered, donut and flat top focal shapes with extended focal depth, potentially useful in optical tweezers, material processing and laser printing can be obtained using this technique. © 2012 Elsevier B.V.

Loading National Institute of Telecommunication collaborators
Loading National Institute of Telecommunication collaborators