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TENCON '96. Proceedings., 1996 IEEE TENCON. Digital Signal Processing Applications

Date 29-29 Nov. 1996

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  • 1996 IEEE TENCON Digital Signal Processing Applications

    Page(s): 0_3 - xii
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    Freely Available from IEEE
  • DSP-based testing system for A/D converters applying quantization theory

    Page(s): 749 - 753 vol.2
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    Classical testing procedures for A/D converters are based on mathematical methods that do not need large and expensive hardware resources. A number of works devoted to introducing new methodologies to test the ADC performance led, on the other hand, to powerful hardware systems in order to implement these tests in a reasonable time. However, these innovative methods, introducing the full dynamic testing condition and considering both the sampling and signal frequencies as evaluation parameters, and the newer testing methodologies, based on completely different mathematical techniques are more efficient and reliable from the accuracy point of view. This article opens the way to the definition of hardware characteristics necessary to allow the dedicated testing for ADCs when Fourier transform analysis based on deterministic quantization is adopted. View full abstract»

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  • Author index

    Page(s): 0_11 - 0_14
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    Freely Available from IEEE
  • 2-dimensional motion-analysis in object-oriented coding

    Page(s): 945 - 948 vol.2
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    This paper describes a motion analysis algorithm in the object-oriented coding for video sequences and objects in the two consecutive frames of the video sequence are assumed to have moved in translational motion only. It incorporates the knowledge of the border coding process which exploits the temporal redundancies between successive image frames. After segmentation, the boundary information of an object can be obtained by employing a chain-coding technique and then this information is used to estimate the motion in the video sequences. Unlike the conventional scheme, our proposed method calculates individual sets of the mapping parameters for each object requiring motion compensation after segmentation View full abstract»

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  • Specialised hardware for state space control of a dynamic process

    Page(s): 895 - 899 vol.2
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    This paper considers the use of an application specific integrated circuit (ASIC) for a stand alone controller. The ASIC estimates process-states and controls a dynamic process. As a case study, an inverted pendulum is used as the controlled process. The process is nontrivial and reflects several industrially related control problems. To control the inverted pendulum it is necessary to estimate the states of the process. This is done with a Kalman filter. The estimated states are used to control the process with a linear quadratic Gaussian regulator. The design of the standalone controller device is divided in two stages: the first is to design the control system; the second is to design the hardware controller device. The control system design is done with Mathlab/Simulink and the hardware controller design is done with Viewlogic/VHDL-models. The first choice target technology is field programmable gate arrays (FPGA) since this technology offers fast prototyping and reasonable cost for experimental work View full abstract»

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  • Band-limited combined orthonormal wavelet bases

    Page(s): 593 - 597 vol.2
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    First, a general procedure for constructing a variety of orthogonal wavelets which are compactly supported in frequency domain is presented. These orthogonal wavelets, as a result of the method of multiresolution analysis (MRA), share the same space structure. This property makes it possible to construct a “combined” orthonormal base of L2(R) which contains more than one wavelet functions. This kind of combined orthonormal wavelet bases are more flexible and are expected to be more efficient than the conventional wavelet bases in data compression, speech coding and image coding View full abstract»

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  • Listening to musical rhythms with progressive wavelets

    Page(s): 508 - 513 vol.2
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    Analysing and modelling the human perception of musical rhythm provides insights into non-verbal knowledge representation, quantification of musicological theories, and intelligent tools for music performance and composition. Linear phase Gabor transform wavelets are an analysis technique capable of making explicit many elements of musical rhythm theory. Transforms over a continuous time-scale plane (the scalogram) spanning rhythmic frequencies (0.1 to 100 Hz) decompose the multiple temporal relationships between beats into hierarchies of periodicities. Wavelets represent well the transient nature of these rhythmic frequencies in performed music, in particular those from expressive deviations from written notation during performance. Using measures of phase congruence over a range of dilation scales are shown to be useful in highlighting structurally important beats. The performance of the wavelet transform is demonstrated on examples of performed monophonic percussive rhythms possessing intensity accents, changing meters and rubato. The transform results indicate the location of such accents and from these, the inducement of phrase structures View full abstract»

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  • An implementation of real-time hardware for moving object detection and discrimination

    Page(s): 961 - 966 vol.2
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    In this paper, we introduce real-time hardware implemented for the purpose of detecting the boundary points of a moving object and discriminating it from non-targets, which are basic functions of an unmanned surveillance system. The implemented hardware is composed of the two parts; one is a hard-wired logic part which computes spatio-temporal derivatives, and the other is a discrimination part including a micro-controller and memory devices. The object boundary is extracted by using a moving region and an edge map which can be detected by temporal derivative followed by morphological erosion and spatial derivative, respectively. We propose newly devised logic circuits for subtraction and thresholding, and spatio-temporal derivatives. Scarcely before individual hardware modules complete their functions, the second image capturing is done by performing the above functions in real-time View full abstract»

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  • Digital-signal-processor-based multirate PID control of a two-link flexible-joint robot

    Page(s): 900 - 905 vol.2
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    Multirate control has become an area of active research. Concurrent with the development of multirate strategies, there have been increasing applications of digital signal processors in high speed control. This paper presents the design and implementation of a multirate PID controller for a two-link flexible-joint robot. The controller is implemented using the TI Digital Signal Processor TMS320C30 evaluation module. Two multirate algorithms, namely multirate output PID controller and multirate input PID controller were designed and implemented. The multirate controllers are shown to be superior to the conventional single-rate PID Controller. Comparison is made in terms of maximum overshoot, rise time and steady-state error of the closed-loop system View full abstract»

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  • Image coding with wavelet software package using lattice quantization

    Page(s): 602 - 607 vol.2
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    An application of lattice quantization for encoding the wavelet coefficients of grey scale images is examined. The wavelet expansion is performed using a wavelet software package. We formally show that lattices give rise to optimal or near optimal quantizers for wavelet coefficients. The theoretical considerations are supported by a number of simulation experiments View full abstract»

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  • An efficient vector-space approach for accurately modeling fixed-point digital signal processors

    Page(s): 659 - 664 vol.2
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    This paper presents the DSP Software Engineering (DSPSE) Fixed Arithmetic Tool (FATTM) method for modeling DSP fixed-point processors and converting an algorithm from a floating-point model to a given DSP fixed-point processor model. All DSP fixed-point processors have associated with them a set of fixed bit length data representations for the storage and manipulation of binary information. We define a vector sub-space for each DSP fixed-point processor, as a direct sum of each distinct fixed bit length data representation sub-space. The direct sum of all DSP fixed-point processor vector subspaces forms a FATTM DSP vector space. Furthermore, for our discussion, we define an operator projection to be performed on our DSP vector space such that redundancy in the operational behavior of the DSPs to be modeled can be exploited. In our preferred embodiment we implement the FATTM vector space in a C++ environment, resulting in a Fixed Arithmetic C++ Tool (FACTTM) library for all associated fixed-point DSPs. For our own development we have created, a FACTTM library for the Texas Instrument TMS320C54x DSP fixed-point processor. The TMS320C54x library has been used in the development of the Japanese Vector Sum Excited Linear Prediction (JVSELP) algorithm and the International Telecommunications Union G.728 standard algorithm View full abstract»

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  • Precise carrier phase GPS and its application to real-time landslide detection

    Page(s): 906 - 911 vol.2
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    The authors have developed a system using precise carrier phase GPS (Global Positioning System) techniques to detect displacement for monitoring the mechanical behavior of an extensive area at the level of a few centimeters. In this paper, the system concepts are described and results of the field experiments to prove the applicability of the system are given. Field tests show that displacements on the order of 2 cm can be detected View full abstract»

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  • Estimation of array mutual coupling and sensor positions for over-the-horizon radar

    Page(s): 846 - 851 vol.2
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    In this paper the Weiss-Friedlander (1989, 1991) MUSIC-type approach, for estimating sensor positions and mutual coupling, are combined and extended for over-the-horizon (OTH) radar applications. The method proposed uses a more accurate model for the coupling matrix, with more unknowns, and uses disjoint sources of opportunity to estimate the coupling matrix and sensor positions. Simulations are conducted, using an experimentally measured coupling matrix, to illustrate the performance of this method. We also show that for OTH radar, echoes from ionised meteor trails may be used as reliable sources of opportunity View full abstract»

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  • Time-frequency analysis of heart sounds

    Page(s): 553 - 558 vol.2
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    From a study of the physical characteristics of heart sounds and human hearing capabilities, it is seen that only the highly trained ear may be able to detect heart sounds events. Also from a study of heart sound signals nature and the frequency domain analysis based on direct application of the Fourier transform technique, it is seen that this technique is inappropriate because important time events and features such as frequency change will be lost. To solve the above mentioned problems the wavelet transform, which is a new time-scale technique suitable for transient signal detection is applied to phonocardiogram signals taken from group of patients. It has been shown that using this new technique the separation between the normal and abnormal subject could easily be obtained. Moreover, a separation between the high frequency systolic and diastolic murmurs, and the low frequency systolic and diastolic murmurs can be achieved. Furthermore, the temporal location of the auscultatory gap can be detected, which is usually very difficult to discern even to the trained ear View full abstract»

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  • Non-linear system/linear measurements approach to passive position location using extended Kalman filtering

    Page(s): 665 - 669 vol.2
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    In solving navigation and tracking problems it has been a widely held view that only the linear system/nonlinear measurement approach is feasible and that it is extremely difficult to derive a non-linear system linear measurements model. Contrary to this view we present here a very simple non-linear system linear measurements model for passive position location problem and apply an extended Kalman filter (EKF) for obtaining position estimates of a stationary emitter. The tabulated results obtained from the Monte Carlo simulations clearly indicate its superiority over the linear system non-linear measurements approach. The problem of a stationary signal being received by a moving aircraft is discussed View full abstract»

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  • Digital analysis of signal intensities

    Page(s): 536 - 540 vol.2
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    In this paper two algorithms for the power intensity and time-frequency characteristics of non-stationary signals are proposed, tested and compared to standard schemes. The first algorithm is based on the continuous time-frequency characteristic and the second is based on the discrete time-frequency characteristic. The performance of each algorithm is evaluated and compared to the existing standard spectrogram analysis. The results show that the proposed power intensity waveform analysis provides very good performance in both continuous and discrete time-frequency characteristics for classical evaluation criteria, and for the preservation of data statistics. The Fourier transform of the intensity of signals is computed in continuous and discrete form. Two methods for the digital implementation of the proposed algorithm are suggested and described. Moreover, it is shown that this algorithm is useful for detecting possible nonstationarity of signals View full abstract»

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  • Design of directional filters using downsampling

    Page(s): 822 - 827 vol.2
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    We present a design method of a directionally oriented 2-D filter (directional filters) and filter bank. At first, we consider the 2-D prototype passband filter. Next, using downsampling, we decimate the prototype filter coefficient and design the directional filters. The passband regions of the component filters are wedge shaped and thus provide the directional information. By using this method, we can reduce the number of filters which we must design. Finally, we show the 2-D filter bank structure with above-mentioned filter View full abstract»

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  • Parallel digital signal processing for image sequence compression

    Page(s): 716 - 721 vol.2
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    This paper presents a practical approach of employing parallel digital signal processing (DSP) techniques to accelerate the execution of an image sequence compression algorithm. The proposed parallel DSP platform consists of an IBM-compatible 486DX33 PC and two identical TMS320C32 DSP cards connected in a star configuration. On average, a speed-up factor of 2.3 has been recorded for the proposed platform View full abstract»

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  • Handwriting and bilevel graphics coding based on quadtree segmented block-run run-length coding

    Page(s): 712 - 715 vol.2
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    An efficient coding scheme for handwriting and bilevel graphics based on quadtree segmentation and block-run run-length coding (RLC) is presented. By segmenting a captured handwriting or graphic image into variable size blocks according to the image activity inside the blocks and run-length coding on a block-run basis, the proposed scheme is able to achieve higher coding efficiency than the conventional one-dimensional RLC and its bit rate is close to that of on-line dynamographical chain coding View full abstract»

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  • A new wavelet network architecture for echo cancellation

    Page(s): 598 - 601 vol.2
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    We put forward a new wavelet network architecture for echo cancellation. We can efficiently identify the echo path by the proposed network structure based on the theory of multiresolution analysis and functional analysis. The corresponding multiresolutional learning algorithm is also presented. The performance of the proposed wavelet network architecture with the corresponding learning algorithm are compared to that of the direct form FIR NLMS adaptive filter with application to echo cancellation. Simulation results indicate that the proposed method can provide faster convergence than the conventional FIR NLMS algorithm while not increasing the computational complexity View full abstract»

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  • Phase coupling detection using a finite number of realizations and non-independent phases

    Page(s): 648 - 653 vol.2
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    Phase coupling detection and quantification by using the bispectrum is theoretically attractive and easy to understand. However some problems appear in practice, especially the bispectrum estimation on a finite (and small) trials number implies false phase coupling detection and bad quantification. Moreover the phase independence which is assumed, for each realization, is not always verified. So, in this paper we discuss an alternative method of phase coupling detection taking into account these two limitations View full abstract»

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  • Slant manipulation and character segmentation for forensic document examination

    Page(s): 933 - 938 vol.2
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    This paper presents some research work that has been undertaken in the area of software tools for forensic document analysis. The purpose of research into this area is to study the methods used by human experts in the forensic analysis and examination of questioned hand-written documents and to formulate computer tools to assist in this task. The computer tools needed will require image processing and pattern recognition techniques View full abstract»

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  • Self-certified identity information using the minimum knowledge

    Page(s): 641 - 647 vol.2
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    We propose the new notion of self-certified identity information that applies the notion of self-certified public key to the case in which the public key is just the identity information. Using the notion of self-certified identity information, we propose a truly “paradoxical” identity-based identification scheme, the corresponding signature scheme which any user can choose his(her) own secret key though it is an identity-based method (that is, it is not a certification-based method). Also as an application of self-certified self-certified information, we propose a practical group signature which was proposed by Chaum (1991). The security of our schemes is based on the difficulty of the γth-residuosity problem and discrete logarithm problem simultaneously. Also our schemes are in the level 2 of trust or in the level 3 of trust. In particular, our schemes are almost as efficient as the Schnorr's (1989) scheme View full abstract»

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  • An application of the wavelet transform for the echo signal from a rotating object

    Page(s): 587 - 592 vol.2
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    The backscattering field from a rotating-moving object is a complex-modulated signal, where the overall scattered field from the object changes over time in both amplitude and phase. Consequently, the Doppler spectrum consists of a central Doppler spectral line caused by the motion and many additional Doppler shift spectral lines caused by the rotation of the object. This paper presents an application of wavelet analysis for the echo signal from a spinning rotor in the time-scale domain. A comparison was also made of the measured-data with the simulated-signal for two rotor speeds through the scalograms of the wavelet transform View full abstract»

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  • Accurate time delay and Doppler stretch estimation in noisy environment

    Page(s): 676 - 680 vol.2
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    A wavelet based wideband cross ambiguity function (WB-WBCAF) has been used in the context of joint estimation of the time delay and Doppler stretch between two received signals (radar and sonar). But in a noisy environment, the performance of the method deteriorates because the WBCAF is severely corrupted by the contamination. In order to provide accurate measurements of the time delay and Doppler stretch for practical applications, a simple denoising method is introduced to the WB-WBCAF algorithm. This has improved the accuracy of the estimation significantly but without involving any additional computation load View full abstract»

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