By Topic

Information, Communications and Signal Processing, 1997. ICICS., Proceedings of 1997 International Conference on

Date 12-12 Sept. 1997

Go

Filter Results

Displaying Results 1 - 25 of 124
  • 1997 International Conference on Information, Communications and Signal Processing Theme: Trends in Information Systems Engineering and Wireless Multimedia Communications

    Page(s): i - xxxiv
    Save to Project icon | Request Permissions | PDF file iconPDF (1891 KB)  
    Freely Available from IEEE
  • Author index

    Page(s): 0_3 - 0_7
    Save to Project icon | Request Permissions | PDF file iconPDF (487 KB)  
    Freely Available from IEEE
  • Subjective coding of best basis wavelet coefficients for multiresolution analysis

    Page(s): 1363 - 1367 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (764 KB)  

    This paper presents a wavelet based image compression algorithm using subjective thresholding and quantization of the wavelet coefficients. subjective compression techniques use the properties of the human visual system (HVS) to eliminate redundant information in an image. By combining the wavelet transform coefficients with psychovisual thresholding and quantization schemes, a coding result of 0.31 bits per pixels has been obtained with weighted PSNR of 39.07 dB View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The integration of VOD and Internet services

    Page(s): 1686 - 1690 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (540 KB)  

    As the information super highway being constructed, many kinds of multimedia on demand services, attracting significant attention, is being tested, and will be realized sooner or later. Considering these social environments, we have implemented a video on demand system. This paper describes the system architecture of the implemented video on demand system, and proposes the efficient structure for users to provide an easy Internet access method. Also, by a navigating service menu with a Web browser, the user can interact with the service provider more easily. Our system harmonizes Internet and VOD services using the World Wide Web View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Adaptive symbol-by-symbol reception of PSK on channels with unknown phase

    Page(s): 1493 - 1495 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (200 KB)  

    We propose an adaptive symbol-by-symbol receiver for phase shift-keying (PSK) over the Gaussian channel with unknown carrier phase. The statistical properties of the carrier phase are assumed unknown to the receiver, other than the fact that it is slowly varying so that a piecewise-constant approximation can be made. The coherent reference for detection is obtained using a first-order filter whose gain is adapted on-line, based on the received signal samples. The performance of the receiver is analyzed both via analysis and simulations View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Propagation modelling of cellular mobile communication on non-Rayleigh and non-Rician fading channels

    Page(s): 1705 - 1708 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (236 KB)  

    If a signal is transmitted between a base station and a mobile unit that is moving through a multipath environment, wave interference among the multipath components results in severe fading of the received signal. Amplitude fluctuations in signals received over mobile radio channels are typically modelled by a Rayleigh distribution. The Rician distribution applies to the case when there is a direct line-of-sight (LOS) component which contributes to the received signal. If there is a signal steady component and a large number of the multipath signals, the propagation environment of the mobile radio is modelled by Rician distribution. These models are theoretically predicted if a large number of random multipath signals exist in the channel with all signal contributions on the same order of magnitude (i.e. no dominate components). When the effective number of scatterers (N) is small, significant deviations from the both Rayleigh and Rician distributions can be expected. In this paper, we tried to examine same statistical characteristics in non-Rayleigh and non-Rician communications channels. Results indicates that, except for the 2 scatterer channel, the computed variations are well fitted to those of theoretically predicted Rayleigh and Rician models View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An invariant pulse-coder for 2-D shape recognition

    Page(s): 1552 - 1556 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (468 KB)  

    We present some novel schemes for (i) pulse coding for invariant representation of shape; and (ii) a neural architecture for recognizing the encoded shape. The proposed shape encoder utilizes the properties of complex logarithmic mapping (CLM) which transforms rotation and scaling (in its domain) to shifts (in its range). In order to handle this shift, in an attempt to provide increased speed of operation, the encoder converts the CLM output to a sequence of pulses. These pulses are fed to a novel multilayered neural recognizer which (i) invokes template matching with a distinct architecture; and (ii) achieves robustness (to noise and shape deformation) by virtue of its overlapping strategy for code classification. The proposed encoder-recognizer system, which is hardware implementable by a high-speed electronic switching circuit, and can add new shapes on-line to the existing ones, is illustrated by examples View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A network architecture for multiuser networked games on demand

    Page(s): 1815 - 1819 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (548 KB)  

    Computer games are a multi-billion dollar a year industry in Japan alone. Multiplayer networked games are a small but growing segment of that market whose importance will increase as high bandwidth networks are deployed domestically through ADSL and cable-modem technology. We examine the software and network architectures of current multiplayer networked games, and identify the problems associated with them. We then propose a new model called multiplayer games on demand that better suits the capabilities of emerging networks. We conclude by evaluating the potential advantages and disadvantages of such a system View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Data flow architecture for the parallel implementation of the functional language

    Page(s): 1452 - 1456 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (404 KB)  

    Data now (DF) architecture resulting from the DF program representation by the functional language being developed at the Department of Computers and Informatics is proposed in the paper. The contribution is concentrated to the efficient implementation of functional language in the DF architecture supporting the idea of the programming parallel problems by specification and transformation using mathematical methods. The combination of a local control flow with a global data flow model in the proposed DF architecture is connected with the direct operand matching mechanism using matching vectors. The concepts of the data flow graph representation using the functional language, the approaches to the parallel execution of the functional program in the data now implementational environment and the DF architecture layout are presented in the paper. It is supposed that the hardware implementation of the architecture can be used as a specialised accelerator in problem-oriented computer systems with high requirements on the operation speed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • E-differentiation for analyzing scalability of parallel algorithms on parallel architectures

    Page(s): 1457 - 1461 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (420 KB)  

    The E-differentiation, which is derived from the idea of isoefficiency analysis and used for analyzing scalability of parallel algorithms on parallel architectures, is proposed in this paper. The basic philosophy of E-differentiation is that scalability analysis should be based on the ratio of the change of E (efficiency of processors) vs. W (Workload), Ew', and E vs. P (number of processors), Ep'. E-differentiation can overcome the incompletion of other metrics for analyzing scalability with assumptions which confine the manner of the increasement of W w.r.t. p; and it is easy to give the equivalent expression of these metrics in terms of E-differentiation so that relationships between these metrics can be studied more definitively. Because E-differentiation does not the restrict of isoefficiency, which confines the generality of the isoefficiency analysis, it can measure the scalability of any parallel algorithms on any parallel architectures, and can predict the change of performance of parallel algorithms when change manner of W w.r.t. p does not follow isoefficiency function View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An adaptive priority traffic control approach for guaranteed services in ATM networks

    Page(s): 1518 - 1521 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (340 KB)  

    This paper presents an adaptive priority traffic control approach which uses a dynamic buffer allocation scheme, and an adaptive priority queuing technique for handling the delay-sensitive traffic in ATM networks. The former adjusts the buffer size based on the real traffic demand, while the latter adaptively change the priority. The simulation results show that diverse delay-sensitive traffic achieve satisfactory performance through our approach. It may fulfill the emerging needs of guaranteed services View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Computer, multimedia and television

    Page(s): 1741 - 1745 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (456 KB)  

    This paper analyses the architecture features of PCs. Three levels of multimedia definition are proposed. The performances and platform features of PCs and TV for multimedia communication are compared. This results in a proposal of a digital TV (DTV) architecture that retains the good features of a PC but enhances the real-time bit stream processing capability. The key conclusion is that DTV is for entertainment and PCs are for work View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimization and quality measurement for the layer 2 compression scheme of MPEG audio coding

    Page(s): 1522 - 1526 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (520 KB)  

    The layer 2 compression scheme of MPEG audio coding is a very common audio coding standard for CD quality audio (music). However, its encoding process requires a large amount of computations. In this paper, we propose some optimization techniques to make the encoding program much faster while allowing to impair the audio quality a little. In order to measure how much quality loss, we define criteria to quantify the quality loss rate of an encoded audio stream. From the definition, we can say that the encoder encoding streams with a quality loss rate equivalently wastes a number of bits, if the encoder that completely conforms to the layer 2 standard can save the same number of bits while keeping the same quality loss rate. In our experiments, we optimize the layer 2 compression programs such that audio streams can be encoded real time on a Pentium Pro 180 with only 0.0003% quality loss and equivalently 1.5% bits wasted and on a Pentium 180 with only 0.0009% quality loss and equivalently 4% bits wasted View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An adaptive early video slice discard (A-ESD) scheme for non-guaranteed ATM services

    Page(s): 1632 - 1637 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (444 KB)  

    A novel cell dropping mechanism named adaptive early slice discard (adaptive-ESD) scheme is proposed to minimize the video quality degradation in a situation of losses due to buffer overflow. The mechanism runs at the video slice level and adaptively and selectively adjusts the discard level to switch buffer occupancy and video cell payload types. To evaluate its performance, we have designed an extended priority assignation scheme (ExPAS) which permits the definition of up to three priority classes per virtual connection. In comparison with previous space priority techniques based on the CLP mechanism, the adaptive-ESD associated with ExPAS shows better results in minimizing the probability of reception of corrupted video slices, as well as a significant improvement of the effective network throughput View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The strategy of inter-processor communication in BDCS for network survivability

    Page(s): 1428 - 1431 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (340 KB)  

    This paper proposes a new inter-processor communication (IPC) method that can reduce the processing time of network restoration such as self healing mesh (SHM) and presents the performance evaluation through the analysis and simulation of the proposed method. This IPC mechanism was adopted at the SDH-based broadband digital cross-connect system (BDCS). Results of simulations are presented. And its performance was proved at the implementation of the SHM function in the BDCS View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A comparison of prediction methods for 900 MHz urban mobile radio propagation

    Page(s): 1696 - 1700 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (484 KB)  

    The field strength or transmission loss prediction is a very important question in the mobile radio systems planning and design. A wide variety of approaches have been developed for the prediction in different conditions. So, the task of selecting an appropriate method, which can be useful in a particular situation, is complex and difficult. A practical comparison of current methods is given in the paper. To verify their prediction accuracy, field tests have been carried out in Belgrade urban area at 950 MHz and the measured and predicted values were compared View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Measurement of blood pressure using wavelet transforms

    Page(s): 1358 - 1362 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (520 KB)  

    This paper describes automatic blood pressure measurement for non-stationary subjects. The objectives include systolic and diastolic pressure measurements for a subject at rest, walking with arm held, and walking with arm swinging. The wavelet transform method was employed to process the blood pressure signals obtained using the auscultatory method. Detection techniques were developed to de-noise the signal, identify the blood pressure pulses and to determine the systolic and diastolic points View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Speech and image compressions by DCT, wavelet, and wavelet packet

    Page(s): 1353 - 1357 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (380 KB)  

    In this paper, the lossy compression methods of speech and image signals by DCT, WT, and WPT are compared for finding the effective compression method. After lossy compression using the threshold criterion, the compressed speech and image signals were reconstructed. The reconstructed signals are measured by SNR and PSNR. The results have showed that for both speech and image signals, WT and WPT have a better performance than DCT. WPT gives the best PSNR among others except for the computational complexity View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Parallel processing in LIPS

    Page(s): 1480 - 1483 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (312 KB)  

    Major problems with parallel languages are concerned with the complexity and lack of expressive power which makes it difficult to produce efficient code and the ease of mapping onto parallel hardware. Also, a parallel language must be independent of specific hardware features as well as the underlying run-time support for it to be manned efficiently on a range of hardware. This paper presents a parallel language (LIPS) which allows the programs to be mapped onto a range of parallel hardware in an efficient manner. LIPS encourages a pipelining effect to occur onboard each processor in a parallel system, with data becoming available to each node once the pipe is full. LIPS uses an asynchronous communication subsystem so that synchronisation delays can be avoided. The communication dynamics being of a dataflow nature, where variables are passed from one process to another as the values become available. LIPS offers facilities for representation of data, flow of control and the manipulation of the network of processes in a practical form suitable for constructing programs for MIMD computing View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Scheduling algorithms for multiprocessor real-time systems

    Page(s): 1470 - 1474 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (452 KB)  

    Real-time systems are subject to fundamental user requirements, such as correctness of the systems, taking into account timeliness and simultaneity, a high degree of predictability. This means that the scheduling algorithm is an important component of these systems. A scheduling algorithm is used to determine a schedule for a set of tasks so that the task's deadlines and resource requirements are satisfied. The potential speedup of applications has motivated the widespread use of multiprocessors in recent years. In this paper, recent results on multiprocessor real-time scheduling algorithms are reviewed. The review takes the form of an analysis of the problems presented by different application requirements and characteristics. A scheduling algorithm for real-time systems to be implemented on multiprocessors is proposed. This algorithm is appropriate for real-time tasks with the precedence constraints View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Characterization and source modeling of MPEG-2 VBR video source

    Page(s): 1652 - 1656 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (364 KB)  

    This paper presents the results of our study on the statistical characterization of MPEG-2 VBR video stream and the modeling of such source. The frame trace, marginal distribution of the frame size and the high autocorrelation existing in the continuous frames are analyzed. An ARMA process is used to model MPEG-2 video source. The different frame types of MPEG-2 video are considered together by performing a normalization transformation during modeling. The performance of the model is examined and the results show that the model is good in fitting the histogram and preserving the property of autocorrelation. We also indicate that the proper order of the ARMA model depends on the frame pattern of the MPEG source View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Linear approach to the least-squares multidimensional polynomial fitting

    Page(s): 1288 - 1292 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (296 KB)  

    It is well known that the least-squares one-dimensional (1-D) polynomial fitting problem is linear. However, multidimensional (M-D) polynomial fitting is often treated as a nonlinear problem. This paper shows that the least-squares M-D polynomial fitting problem is also a linear problem, and proposes a linear method for solving it. Two fitting examples in the 2-D case are given to illustrate the effectiveness of the proposed method View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Estimation of the hysteresis value for handover decision algorithms using Bayes criterion

    Page(s): 1771 - 1775 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (336 KB)  

    In mobile radio communications, inter-cell handover is the process whereby a call in progress is maintained while the mobile unit passes through different cells. Current handover decision algorithms compare the difference between the received signal strengths from different base-stations to a hysteresis value. The proposed paper is a contribution towards an optimal estimation of the hysteresis value using Bayes criterion. An expression of the threshold value h is derived in terms of the standard deviation a of the log-normal shadowing affecting the received signals and the ratio η between the a priori probability of handover and probability of no handover. The performance of the handover decision algorithm is evaluated in terms of the probability of false alarm, or probability of unnecessary handover, and probability of detection, or probability of successful handover View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Determining optimum subband edges for signal compression

    Page(s): 1542 - 1546 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (356 KB)  

    The coding gain in subband coding, a popular technique for achieving signal compression, depends on how the input signal spectrum is decomposed into subbands. The optimality of such decomposition is conventionally addressed by designing appropriate filter banks. The issue of optimal decomposition of the input spectrum is addressed by choosing the set of band that, for a given number of bands, will achieve maximum coding gain. A set of necessary conditions for such optimality is derived, and an algorithm to determine the optimal band edges is then proposed. These band edges along with ideal filters, achieve the upper bound of coding gain for a given number of bands. It is shown that with ideal filters, as well as with realizable filters for some given effective length, such a decomposition system performs better than the conventional nonuniform binary tree-structured decomposition in some cases for AR sources as well as images View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Parallel functional disk array for high performance computing

    Page(s): 1447 - 1451 vol.3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (548 KB)  

    In high performance scientific computing, operations such as searching, sorting, filtering are very frequent. Due to limited access ability of storage system and limited capacity of main memory, it is difficult to archive high performance of data access using traditional methods, and it is also impossible to carry all the data into main memory and operate in the memory. A new kind of storage system architecture, called Parallel Functional Disk Array (PFDA), is proposed in this paper. The study of the PFDA in this paper is mainly focused on the following two aspects: one is the architecture study of PFDA, including the storage requirement of high performance scientific computing environment and the operation frequency for different function, the other is the algorithm of dynamic analysis and scheduling of function units to perform in parallel, so as to solve the conflict problem among function units and the data dependent problem caused by the data distribution in the redundant disk array View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.