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Telecommunications Symposium, 1998. ITS '98 Proceedings. SBT/IEEE International

Date 9-13 Aug. 1998

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  • ITS/98 Proceedings-SBT/IEEE International Telecommunications Symposium [front matter]

    Publication Year: 1998, Page(s):i - xxiv
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    Freely Available from IEEE
  • Author index

    Publication Year: 1998, Page(s):676 - 677
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    Freely Available from IEEE
  • Two-scale transmission of DCT-coded video over lossy packet networks

    Publication Year: 1998, Page(s):510 - 515 vol.2
    Cited by:  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (408 KB)

    This paper discusses the development and results of a simulation package for two-scale transmission of discrete cosine transform (DCT)-coded video over lossy packet networks. The considered scalability of coded video sequences is based on variations of data partitioning and requantization techniques. These variations contemplate situations in which the reference signal used in predicted (P-type) o... View full abstract»

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  • Reducing Bayes equalizer complexity: a new approach for clusters determination

    Publication Year: 1998, Page(s):428 - 433 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (388 KB)

    A new strategy for channel equalization in digital communication is presented. In this approach, the clustering problem is treated analytically. We propose a systematic Bayesian classification using a Gaussian approximation of the probability density function for each cluster. The quality of the approximation depends on the number of clusters considered. We show analytically that we can obtain the... View full abstract»

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  • Implementing a distributed Web-based management system in Java

    Publication Year: 1998, Page(s):554 - 559 vol.2
    Cited by:  Papers (3)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (496 KB)

    The distribution requirement of current and future networked environments has led to a shift from traditional centralized towards distributed management approaches. A distributed architecture for network management is presented The architecture implementation is based on an extensive use of emerging client/server, Web and Java technologies, the pursued objective being to promote flexibility, openn... View full abstract»

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  • A supervised neural constant bit rate video controller for MPEG2 encoders

    Publication Year: 1998, Page(s):504 - 509 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (400 KB)

    A supervised training algorithm is used in a radial basis function neural network in order to improve the performance of a recently introduced nonlinear predictive rate controller for MPEG2 encoders. The algorithm, which is based on the stochastic gradient method, is used for updating the radial basis centers. By means of extensive computer simulation with standard video sequences, practical desig... View full abstract»

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  • Novel reuse patterns for microcellular networks

    Publication Year: 1998, Page(s):383 - 387 vol.2
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (464 KB)

    This paper proposes novel reuse patterns for a microcellular network based on a square grid. An initial carrier-to-interference ratio assessment for these patterns considers the mobiles positioned at the worst-case condition and the system operating at full load. Among the possible reuse patterns (1, 2, 4, 5, 8, 9, 10, 13, ...microcells per cluster) the performance analysis investigates systems wi... View full abstract»

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  • Texture smoothing and object segmentation using feature-adaptive weighted Gaussian filtering

    Publication Year: 1998, Page(s):650 - 655 vol.2
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1052 KB)

    Gaussian filter kernels can be used to smooth out textures in order to obtain uniform regions for image segmentation. In so-called anisotropic diffusion techniques, the smoothing process is adapted according to the edge direction in order to preserve the edges. However, the segment borders obtained with that approach do not necessarily coincide with physical object contours, especially in the case... View full abstract»

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  • A new class of wide-band microstrip arrays

    Publication Year: 1998, Page(s):424 - 427 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (252 KB)

    Wide-band microstrip antennas are still a challenge and in the last couple of years a number of new configurations have been reported. Most of these configurations are multilayer patch antennas with some of them achieving up to 40% in bandwidth. Recently, another new geometry has been reported, a single patch fed by a three-dimensional feed line, which in essence is a very tall patch fed by a wide... View full abstract»

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  • Enhancing an optical access network with ADSL technology

    Publication Year: 1998, Page(s):548 - 553 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (408 KB)

    This paper gives a short overview on narrowband access networks and the need for enhancing these networks with ADSL transmission techniques. After a short introduction to ADSL, the current status of the standardization process for ADSL is reflected. A major open topic in the physical layer is ADSL over ISDN transmission. There are many other open issues for higher layers. The work of the ADSL Foru... View full abstract»

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  • Video quality assessment using objective parameters based on image segmentation

    Publication Year: 1998, Page(s):498 - 503 vol.2
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (604 KB)

    This work presents a methodology for video quality assessment using objective parameters based on image segmentation. Natural scenes are segmented into plane, edge and texture regions, and a set of objective parameters are assigned to each of these contexts. A perception-based model that predicts subjective ratings is defined by computing the relationship between objective measures and results of ... View full abstract»

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  • Throughput evaluation of TMN EMS for ATM switch

    Publication Year: 1998, Page(s):566 - 570 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (384 KB)

    The development of the TMN (telecommunication management network) system is active in Korea. ETRI has developed TMN EMS (element management system) with the development of an ATM switch. In the next year, these systems will be in operation in the Korean ATM network. We introduce our EMS and analyse the throughput of EMS. In order to analyse the throughput, we use an open queuing network model and ... View full abstract»

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  • On the statistics of the Nakagami-m signal

    Publication Year: 1998, Page(s):377 - 382 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (340 KB)

    This paper proposes a fading model that leads to a formal, but simple, method to obtain the exact formula of the Nakagami-m distribution for m=n/2, n a non-zero integer number. Based on such a model the joint distribution of the envelope and its time derivative is accomplished and exact formulas for the level crossing rate (closed-form formula) and for the average fade duration are derived. Simula... View full abstract»

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  • Fuzzy image processing based on spatial convolution operators

    Publication Year: 1998, Page(s):662 - 666 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (568 KB)

    This paper presents a method for image processing based on a set of fuzzy inference rules. These rules generate a mapping by considering the results obtained from the convolutional operation between classic operators and a given image. The spatial convolution masks are selected due their easy implementation. Experimental results reveal some promising applications of the proposed method View full abstract»

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  • Compressing images using edges and textures separately

    Publication Year: 1998, Page(s):577 - 581 vol.2
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1012 KB)

    This paper presents an image compression technique that codifies edges and textures of a given image separately using the wavelet transform. The proposed method has been developed in order to improve a low bit-rate scheme for still images. This kind of approach produces image contours that are well-defined and are not destroyed by the compression process, which is what usually happens on most codi... View full abstract»

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  • Image coding with low blocking effects using discrete sine transform with axis rotation

    Publication Year: 1998, Page(s):588 - 593 vol.2
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (576 KB)

    The blocking effect is a problem that is always present in image coding by blocking transform. A simple method for image coding, with low blocking effect, using pre- and post-axis rotation and the discrete sine transform, is presented. The method was implemented, and the results obtained by simulation in the image coding are compared with image coding by DCT and LOT View full abstract»

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  • Mobile code implementation of the RTP protocol in Java: design choices and evaluation

    Publication Year: 1998, Page(s):644 - 649 vol.2
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (384 KB)

    The use of a mobile code, partly interpreted language such as Java is investigated as a tool to build highly portable implementations of multimedia communication protocols. In particular, we concentrate on the implementation of the real-time protocol and focus our attention on three main issues: first, we evaluate the quality and accuracy of the services offered by some relevant primitive operatio... View full abstract»

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  • Efficient tree construction for the multicast problem

    Publication Year: 1998, Page(s):632 - 637 vol.2
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (604 KB)

    A new heuristic for the Steiner minimal tree problem is presented. The method described is based on the detection of particular sets of nodes in networks, the “hot spot” sets, which are used to obtain better approximations of the optimal solutions. An algorithm is also proposed which is capable of improving the solutions obtained by classical heuristics, by means of a stirring process ... View full abstract»

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  • On the equivalence between propelinear and binary G-linear codes

    Publication Year: 1998, Page(s):525 - 527 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (160 KB)

    The main objective of this paper is to establish a relationship between propelinear codes and binary G-linear codes as defined in Costa et al., (1997). We show that every binary G-linear code is a propelinear code by showing that the group structure induced by either one of these codes is related to the semi-direct product View full abstract»

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  • Limits on bit rate capacity improvement induced by SPM in installed standard fiber links at 1550 nm

    Publication Year: 1998, Page(s):606 - 610 vol.2
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (348 KB)

    Limits are obtained to a method which utilizes fiber nonlinearity (self phase modulation) to increase the bit-rate capacity of installed single channel non-dispersion-shifted fiber links at a wavelength of 1550 nm. We focus on a set-up that uses no in-line optical amplifiers. Maximum attainable bit rate versus distance are obtained under optimal transmitted powers for different pulse shapes, which... View full abstract»

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  • Superconductivity in generic microstrip line with multilayer semiconductor substrate

    Publication Year: 1998, Page(s):419 - 423 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (300 KB)

    The theory of multilayer shielded and open microstrip lines considering the superconductor strip on semiconductor regions is presented. The transverse transmission line (TTL) is used in the analysis. The superconductor effect is included in the boundary conditions with the surface impedance that is related to the complex conductivity of the material, calculated from the advanced two-fluid model. A... View full abstract»

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  • Nonlinear switching recovery in planar directional coupler with loss

    Publication Year: 1998, Page(s):405 - 409 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (284 KB)

    Twin-core nonlinear directional couplers that include loss and nonlinear refractive index are examined. The inclusion of loss results in the increase of the critical power of the coupler while the switching characteristics deteriorate. To compensate for this behavior associated with the loss, we investigate the effect of the nonlinearity profile on the performance of an increasing nonlinearity cou... View full abstract»

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  • FLEXOS, a telecommunications management network system

    Publication Year: 1998, Page(s):542 - 547 vol.2
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (676 KB)

    This paper presents an experiment with an integrated telecommunication management system construction. It refers to the development of FLEXOS, a system that accomplishes the configuration management and fault management of telecommunications networks, comprising equipment manufactured by Digitro Tecnologia Ltda. This work embraces the whole development process, from the information modeling and im... View full abstract»

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  • Service location for mobile agent systems

    Publication Year: 1998, Page(s):623 - 626 vol.2
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (308 KB)

    One of the main challenges of the mobile agent technology is how to obtain a host that provides the service specified by the agent. This work proposes a service location module for a development environment for agent-based systems named GTA/AG infrastructure (GTA/agent). This module makes easier the agent programming since the service location module provides the agent's destination View full abstract»

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  • A coded modulation scheme for a broadcast AWGN channel

    Publication Year: 1998, Page(s):458 - 461 vol.2
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (264 KB)

    This paper proposes a coded modulation scheme for transmission of two classes of information on a broadcast AWGN channel. The scheme is based on multilevel coding with a nonstandard partition of a 32-QAM constellation. The QAM constellation consists of four groups of 8-PSK subconstellations instead of 8-QAM subconstellations. This results in a constellation with reduced peak-to-average power ratio... View full abstract»

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