Denilson C. Silva, Amaro A. de Lima, R. Maia, Daniela Braga, Joao F. de Moraes, Joao A. de Moraes, Fernando G. V. Resende
{"title":"A rule-based grapheme-phone converter and stress determination for Brazilian Portuguese natural language processing","authors":"Denilson C. Silva, Amaro A. de Lima, R. Maia, Daniela Braga, Joao F. de Moraes, Joao A. de Moraes, Fernando G. V. Resende","doi":"10.1109/ITS.2006.4433335","DOIUrl":"https://doi.org/10.1109/ITS.2006.4433335","url":null,"abstract":"This paper presents a grapheme-phone converter and stress determination algorithm based on rules. The proposed set of rules was implemented and tested on a randomly chosen extract of the CETEN-Folha text database. Computer experiments show it is achieve an accuracy of 97.44% and 98.58%, respectively, for the grapheme-phone converter and the stress determination algorithm.","PeriodicalId":271294,"journal":{"name":"2006 International Telecommunications Symposium","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116969675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A.P. da Silva, F. de S. Chaves, V. de Sousa, R.A. de O. Neto, F. Cavalcanti
{"title":"Performance evaluation of access selection algorithms for VoIP on wireless multi-access networks","authors":"A.P. da Silva, F. de S. Chaves, V. de Sousa, R.A. de O. Neto, F. Cavalcanti","doi":"10.1109/ITS.2006.4433356","DOIUrl":"https://doi.org/10.1109/ITS.2006.4433356","url":null,"abstract":"The tendency of wireless communication systems beyond 3G is the wireless multi-access (MA) environment, which is characterized by the integration of different radio access networks (RANs). Parallel to the wireless network evolution, Voice over Internet Protocol (VoIP) is one of the fastest growing Internet real-time applications. Implementation of VoIP over a multi-access network requires the incorporation of efficient resource allocation strategies, namely, common radio resource management (CRRM), in order to meet the optimum combined network performance. In this paper, we propose access selection (AS) algorithms for MA networks and evaluate their performance for VoIP service. Conventional AS algorithms are taken as reference.","PeriodicalId":271294,"journal":{"name":"2006 International Telecommunications Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117110282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An enhanced allocation resource mechanism for diffserv domains using bandwidth broker","authors":"L. Reis, P. R. Guardieiro","doi":"10.1109/ITS.2006.4433294","DOIUrl":"https://doi.org/10.1109/ITS.2006.4433294","url":null,"abstract":"Although the Bandwidth Broker has been proposed with the objective to give more intelligence to DiffServ networks, allowing the allocation of resources in a dynamic way for applications, once the resources are granted they remain statically allocated along the requested period. In this article, we propose an enhanced resource allocation mechanism, based on the fact that the instantaneous traffic load of the applications are generally dynamic in nature, and consequently, the required bandwidth is less than the allocated bandwidth during some periods. Simulation results demonstrate that the proposed mechanism yields better resource utilization while respecting limits of drop of packets and end-to-end delay.","PeriodicalId":271294,"journal":{"name":"2006 International Telecommunications Symposium","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115373042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Trilinear Space-Time-Frequency Codes for broadband MIMO-OFDM systems","authors":"A. D. de Almeida, G. Favier, J. Mota","doi":"10.1109/ITS.2006.4433375","DOIUrl":"https://doi.org/10.1109/ITS.2006.4433375","url":null,"abstract":"A new multi-antenna coding framework is proposed for space-time-frequency (STF) transmissions over broadband multiple input multiple output (MIMO) systems based on orthogonal frequency division multiplexing (OFDM). A tensor decomposition known as PARAFAC is used as the core of a multi- stream space-time-frequency coder that jointly multiplex and spreads several input streams over space (transmit antennas), time (symbol periods) and frequency (subcarriers). We coin the term trilinear STF codes since each input symbol is coded over a space-time-frequency grid by a triple product code: each trilinearly coded symbol is interpreted as an element of a third-order tensor, which can be decomposed using PAFAFAC analysis. Trilinear STF codes are designed for an arbitrary number of transmit and receive antennas. They afford a variable degree of multiplexing-spreading over each one of the three signal dimensions while providing full diversity gain for each multiplexed stream. At the receiver, a direct blind decoding based on a relatively simple linear processing is made possible thanks to the PARAFAC modeling of the received signal. Computer simulation results are provided for performance assessment of the proposed codes in a variety of configurations.","PeriodicalId":271294,"journal":{"name":"2006 International Telecommunications Symposium","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114516656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Sousa, C. Sales, J. Carvalho, J.C. Costa, C.R.L. Francs, M. Segatto
{"title":"Optimization of bragg grating in optical fiber using modified fitness function and an accelerated genetic algorithm","authors":"M. Sousa, C. Sales, J. Carvalho, J.C. Costa, C.R.L. Francs, M. Segatto","doi":"10.1109/ITS.2006.4433278","DOIUrl":"https://doi.org/10.1109/ITS.2006.4433278","url":null,"abstract":"This work presents modified genetic algorithm to optimize the fiber Bragg gratings parameters. It is shown that appropriate reformulation of the fitness function and modifications in GA operation are possible to project high quality optical filters and to reduce the computational cost of the technique. The genetic algorithm is used to optimize the index modulation profile and geometry of the Bragg grating for application in WDM systems. In theses systems, optical filters with side lobes levels below -30 dB in the 1550-nm window are demanded. Some projects of optical filter are used to compare this new approach with traditional GA.","PeriodicalId":271294,"journal":{"name":"2006 International Telecommunications Symposium","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116164833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Optimization of the number of Gaussian components for speaker identification","authors":"R. R. Cirigliano, F. Resende","doi":"10.1109/ITS.2006.4433310","DOIUrl":"https://doi.org/10.1109/ITS.2006.4433310","url":null,"abstract":"In this paper we present an algorithm that searches the optimal number of components for each speaker based on the rate between the maximum and the average distortion in each cell obtained through the k-means algorithm. The speakers are modeled by orthogonal GMM and each of them has a different number of components. The tests showed that the usage of this algorithm decreases the error rate in average 36.2% and also decreases the computational effort of the identification process in average 48% when compared to orthogonal GMM models.","PeriodicalId":271294,"journal":{"name":"2006 International Telecommunications Symposium","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114171282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Hierarchical multiscale image segmentation","authors":"K. S. Silva, G.G. Lima, F. Medeiros","doi":"10.1109/ITS.2006.4433372","DOIUrl":"https://doi.org/10.1109/ITS.2006.4433372","url":null,"abstract":"We present a new image segmentation algorithm by developing a hierarchical tree through a non-linear scale-space approach. Aiming at preserving edges better than the Gaussian blurring, this segmentation process is accomplished in three stages. Our method starts creating a scale-space from the original image and a whole family of blurred images is generated using a modified version of the wavelet a trous algorithm. In the following steps, the hierarchical tree of blurred images is built and the linking procedure is performed so that the segmentation process is concluded. Experiments show that the proposed method works quite satisfactory and produces good results.","PeriodicalId":271294,"journal":{"name":"2006 International Telecommunications Symposium","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127543999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
LISANDRO LOVISOLO, Eduardo A. B. da Silva, P. Diniz
{"title":"An efficient Lloyd-Max quantizer for Matching Pursuit decompositions","authors":"LISANDRO LOVISOLO, Eduardo A. B. da Silva, P. Diniz","doi":"10.1109/ITS.2006.4433248","DOIUrl":"https://doi.org/10.1109/ITS.2006.4433248","url":null,"abstract":"Several applications are using the matching pursuit algorithm for signal and video compression. The matching pursuit approximates signals iteratively using linear combinations of pre-defined atoms of a dictionary. In compression applications matching pursuits coefficients, which multiply the atoms in the linear combination, need to be quantized. The Lloyd-Max quantizer is known to be the best quantizer for a given source. However, to design a Lloyd-Max quantizer the statistics of the source need to be known. The statistics of matching pursuit coefficients are difficult to model. In this paper, starting from the observation that the statistics of the angles between the residues and the atoms present little variation along matching pursuit iterations, we propose to use these statistics to model the ones of matching pursuit coefficients. This permits the design of Lloyd-Max quantizers for matching pursuit coefficients. The Lloyd-Max quantize is compared to a state-of-the-art off-loop matching pursuit quantization scheme. Results show that the proposed scheme has good rate-distortion performance, specially at low rates.","PeriodicalId":271294,"journal":{"name":"2006 International Telecommunications Symposium","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126810440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Accelerating the convergence of the widely linear LMS algorithm for channel equalization","authors":"F. de Aquino, C. D. da Rocha, L. Resende","doi":"10.1109/ITS.2006.4433369","DOIUrl":"https://doi.org/10.1109/ITS.2006.4433369","url":null,"abstract":"In this paper, we investigate the use of some classical techniques for accelerating the convergence of the LMS algorithm in widely linear (WL) adaptive processing. The application of channel equalizing is considered. Simulation results permit to verify that the normalized LMS strategy presents the best performance as far as a reduction of the trade-off between the convergence rate and steady-state error is concerned.","PeriodicalId":271294,"journal":{"name":"2006 International Telecommunications Symposium","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127066630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"5-ary turbo codes with 4-5-PSK modulation","authors":"J. da Silva Barros, R. B. Filho","doi":"10.1109/ITS.2006.4433409","DOIUrl":"https://doi.org/10.1109/ITS.2006.4433409","url":null,"abstract":"This work presents 5-ary turbo coded phase modulation. 5-ary turbo coded modulation consists of two 5-ary recursive systematic convolutional encoders, an interleaver together with a puncturing and a hybrid 4-5-PSK modulation scheme. The turbo decoding process is performed by a 5-ary iterative algorithm, based on the maximum a posteriori (MAP) decoding. The simulations show that 5-ary turbo coded phase modulation presents better performance than 4-ary (quaternary) turbo codes.","PeriodicalId":271294,"journal":{"name":"2006 International Telecommunications Symposium","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125902523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}