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Intelligent Signal Processing and Communication Systems, 2004. ISPACS 2004. Proceedings of 2004 International Symposium on

Date 18-19 Nov. 2004

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Displaying Results 1 - 25 of 188
  • Design of address generation unit for audio DSP

    Publication Year: 2004 , Page(s): 616 - 619
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (328 KB) |  | HTML iconHTML  

    The paper presents an address generation unit (AGU) for an audio DSP. The proposed AGU employs an enhanced FFT address generation unit (FAGU) that automatically calculates the butterfly input/output data addresses. The FFT is one of the key tasks for the modified discrete cosine transform (MDCT) mostly used in various audio algorithms. The number of FFT computation cycles can be reduced by the proposed FAGU. The proposed AGU has been synthesized using the SEC 0.18 μm standard cell library. The proposed FAGU has been implemented and the gate count is 1,523. The size is decreased about 73% compared with the FAGU that we have previously proposed. View full abstract»

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  • Enhanced active shape model using evolutionary computation and its extension to RGB color space

    Publication Year: 2004 , Page(s): 75 - 79
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (382 KB) |  | HTML iconHTML  

    This paper deals with an application of evolutionary computation to active shape model (ASM) for locating and analyzing objects an image. The ASM algorithm has proved to be a successful method for segmentation of objects in gray-scale images. However, a number of modifications and extensions to the basic ASM algorithm have been proposed to cope up with various limitations. The proposed method in this paper relies on two such extensions: (i) evolutionary algorithm for better local structure model; and (ii) incorporation of color information for solving the outlier problem in model fitting. View full abstract»

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  • Smooth adaptive playout control for synchronized multicast media streaming

    Publication Year: 2004 , Page(s): 129 - 132
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (346 KB) |  | HTML iconHTML  

    Recently we have proposed a synchronized multicast media streaming framework employing adaptive playout which is based on time-scale modification of audio. In our previous scheme, the playout speed at each client is varied to control intra/inter-client synchronization accuracy and buffer occupancy level by using adaptive playout. In this paper, we update the previous adaptive playout control scheme focusing on the buffer management aspect. The proposed scheme consists of three stages. First, adaptive playout control has a smoothing stage which gradually adjusts playout speed. Secondly, a variation stage changes the playout speed to the limit (i.e., till maximum playout factor) so that buffer occupancy level is stabilized back around target level. Finally, a stabilization stage needs to maintain the buffer occupancy level around target level. Simulation results show the proposed scheme can enhance the performance of buffer control while satisfying the synchronization need. View full abstract»

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  • MP3-resistant music steganography based on dynamic range transform

    Publication Year: 2004 , Page(s): 266 - 271
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (379 KB) |  | HTML iconHTML  

    In this paper, we present a novel audio steganography scheme for embedding high-capacity covert data in a music carrier, where the carrier is first filtered into a sub-signal, insensitive to the human auditory system, using a dynamic range filter, then the sub-signal is downsampled and transformed to a 2D arrangement (image), and finally the image is transformed to a wavelet domain singular value decomposition (SVD) on which a quantization-index-modulation process is applied for embedding the covert data. The proposed scheme, due to its indirect embedding on the singular values of the dynamic range filtered data in the visual domain, possesses a high and flexible embedding capacity and a superb MP3 robustness while retaining an excellent inaudibility. The MP3 robustness and the imperceptibility are further enhanced by adaptively modeling the quantization parameters, based on the statistics within subbands. The embedded data extraction is also secure and oblivious. View full abstract»

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  • Utilization of finite-alphabet (FA) signals for the underdetermined blind source separation in a weakly nonlinear channel

    Publication Year: 2004 , Page(s): 133 - 136
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (284 KB) |  | HTML iconHTML  

    In this paper, an underdetermined blind source separation in a weakly static (or memoryless) nonlinear channel with multi-input and single-output (MISO) is proposed. For that purpose, the finite alphabet coding, and a real-time self-organizing map algorithm are utilized. Finally, some simulation results, obtained by considering application of the proposed approach to power-line communications, are provided to demonstrate its validity. View full abstract»

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  • Multiscale surface representation scheme for point clouds

    Publication Year: 2004 , Page(s): 232 - 237
    Cited by:  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (446 KB) |  | HTML iconHTML  

    We introduce a new multiscale point cloud representation scheme based on a tree-structured multiscale piecewise plane approximation of the underlying 3D surface geometry. Dyadic division and plane approximation of points within each dyadic cube result in a tree-structured multiscale representation of the 3D surface described by point cloud data. We then perform a complexity-regularized tree pruning combined with adaptive control of plane thickness to obtain a very compact representation of the surface geometry. Based on its adaptivity and multiscale structure, the proposed representation scheme provides a desirable framework for modelling, coding and processing of point cloud data. We demonstrate the performance of the proposed algorithm through experiments of rendering point clouds. View full abstract»

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  • A study on noise reduction system based on ALE and noise reconstruction filter

    Publication Year: 2004 , Page(s): 305 - 308
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (335 KB) |  | HTML iconHTML  

    A noise reduction technique to cancel wideband and sinusoidal noise in noisy speech is proposed. In actual environments, the background noise frequently includes sinusoidal noise, for example ventilating fan noise. Therefore, it is important to reduce sinusoidal noise. We have proposed a noise reconstruction system (NRS) with adaptive line enhancer (ALE). However, the quality of the enhanced speech is remarkably degraded. In order to solve the problem, we propose a new noise reduction system which uses two types of ALE and a noise reconstruction filter (NRF). First, the two ALEs estimate the speech components. However, since two ALEs cannot estimate the unvoiced sound, the quality of the speech enhanced by the two ALEs is inadequate. Thus, the NRF is used to improve the noise reduction ability. The NRF accurately estimates the background noise from the signal occupied by the noise components, which is obtained by subtracting the speech enhanced by the two ALEs from the noisy speech. The enhanced speech is obtained by subtracting the reconstructed noise from the noisy speech. Finally, the cascaded structure of the noise reduction system is proposed to improve further the quality of the enhanced speech. View full abstract»

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  • Fast encoding method for vector quantization based on subvector technique with a modified data structure

    Publication Year: 2004 , Page(s): 570 - 573
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (363 KB) |  | HTML iconHTML  

    The encoding process of vector quantization (VQ) is a time bottleneck to its practical application. In order to speed up the process of VQ encoding, it is possible to estimate the Euclidean distance first with just a lighter computation to try to reject a candidate codeword. In order to estimate the Euclidean distance, appropriate features of a vector become necessary. By using the famous statistical features of the sum and variance for a k-dimensional vector and furthermore for its two corresponding (k/2)-dimensional subvectors, it is easy to estimate the Euclidean distance so as to reject most of the unlikely codewords for a certain input vector (Guan, L and Kamel, M., 1992; Lec, C.H. and Chen, L H., 1994; Baek, S. et al., 1997; Pan, J.S. et al., 2003). Because it is very heavy to compute the variance of a k-dimensional vector online, a new feature, which is based on the variances of two subvectors, is constructed to estimate the Euclidean distance. Meanwhile, a modified more memory-efficient data structure is proposed for storing all features of a vector to reduce extra memory requirement compared to the latest previous work (Pan, J.S. et al., 2003). Experimental results confirmed that the proposed method is more search efficient. View full abstract»

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  • Programmable low-density parity-check decoder

    Publication Year: 2004 , Page(s): 801 - 804
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (363 KB) |  | HTML iconHTML  

    This paper presents a programmable semi-parallel architecture for low-density parity-check (LDPC) codes. Communication conflicts are avoided by edge-coloring the code graph and grouping of edges/physical connections by color. The architecture model is easily scalable and programmable for larger block sizes. Though the communication hardware cost is high, the model can be easily reconfigured to reduce hardware cost at the expense of flexibility in code design and decoding performance. The hardware cost, latency, code flexibility and code performance tradeoffs can be varied over a wide range to suit a wide range of applications. Simple execution control and mapping are other advantages of this model. A behavioral VHDL implementation was developed to verify the functionality of the architecture. View full abstract»

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  • Rapid shape acquisition for face recognition using the absolutely coded pattern

    Publication Year: 2004 , Page(s): 620 - 624
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (355 KB) |  | HTML iconHTML  

    The paper presents a rapid shape acquisition system for face recognition. For face recognition, time efficiency is very important. So we focus on acquiring rough face data rapidly. The system is composed of two cameras and one projector. The technique works by projecting a pattern on the object and capturing two images with two cameras. We use a 'one shot' system which provides 3D data acquired by a single image per camera. The system is good for rapid data acquisition. We use the 'absolutely coded pattern' using the hue and saturation of pattern lines. In this 'absolutely coded pattern', all patterns have absolute identification numbers. We solve the correspondence problem between the two images by using epipolar geometry and absolute identification numbers. In comparison to the 'relatively coded pattern' which uses relative identification numbers, the 'absolutely coded pattern' helps obtain rapid 3D data by one to one point matching on an epipolar line. Because we use two cameras, we obtain two images which have similar hue and saturation. This enables us to have the same absolute identification numbers in both images, and we can use the absolutely coded pattern for solving the correspondence problem. The proposed technique is applied to face data and the total time for shape acquisition is estimated. View full abstract»

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  • Robust speech enhancement using multi H filters

    Publication Year: 2004 , Page(s): 169 - 172
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (328 KB) |  | HTML iconHTML  

    Since the speech enhancement algorithm based on a Kalman/Wiener filter requires a priori knowledge of the noise statistics and is focused on the minimization of the variance of the estimation error of the speech signal, a small estimation error on the noise may lead to a large estimation error. However, an H filter does not require any assumptions and a priori knowledge on the noise statistics and it searches the best estimated signal that has the minimum error from all the estimated signals applying least upper bound, so it is more robust to a change of noise than the Kalman/Wiener filter. We propose a speech enhancement method based on multi H filters. First, HMM parameters are estimated with the training data. Second, the speech signal is filtered with a fixed number of H filters. Finally, the estimated clean speech is obtained from the sum of the weighted filtered outputs. Experimental results shows about 1-2 dB SNR improvement with increment of computation compared with the conventional Kalman filtering method. View full abstract»

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  • Digital watermarking for color video using a nonlinear filter in detection process

    Publication Year: 2004 , Page(s): 278 - 282
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (339 KB) |  | HTML iconHTML  

    A new watermarking method for color video, using a nonlinear digital filter, is proposed. This method is based on Haitsma and Zhao's methods which embed watermark signals into the luminance mean series, but newly introduce a nonlinear digital filter, named a component separating filter (CS filter), in the detecting process to improve the detection performance. The CS filter can effectively extract the small-amplitude watermark signals on the mean series without being affected by an abrupt shot change. Moreover, it is shown that higher performance is realized by embedding into the color difference signal instead of the luminance. Computer simulations verify its performance. View full abstract»

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  • The voltage controlled crystal oscillator with the positive emitter coupled logic

    Publication Year: 2004 , Page(s): 781 - 783
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (235 KB) |  | HTML iconHTML  

    We have developed the voltage controlled crystal oscillator (VCXO) with positive emitter coupled logic (PECL). The PECL has a delay time less than 2 ns and faster logic gate, and high level output greater than 2.3 V and low level output smaller than 1.68 V. View full abstract»

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  • Implementation of application-specific signal processor for high-speed communication systems

    Publication Year: 2004 , Page(s): 250 - 255
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (420 KB) |  | HTML iconHTML  

    This paper describes the implementation of an application-specific DSP for OFDM communication systems. The proposed instructions can support computations of various blocks in OFDM systems. The data ALU is specially designed and optimized for the proposed instructions. Performance comparisons show that the number of clock cycles improves over 10% compared with Carmel DSP, over 50% compared with TMS320C62X for FFT computation and over 40%-80% for scrambling, convolutional encoding and interleaving, compared with these DSPs. However, the size of the DSP is much smaller than existing DSPs. The proposed architecture is implemented using the iPROVE FPGA board and verification is performed using assembly programs that implement most of the OFDM blocks. View full abstract»

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  • POCS supperresolution image reconstruction using wavelet transform

    Publication Year: 2004 , Page(s): 67 - 70
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (325 KB) |  | HTML iconHTML  

    Research interest in multi-frame supperresolution has risen substantially in recent years and it is expected to have wide applications to medicine. This paper presents a modified projection onto convex sets (POCS) superresolution method based on the wavelet transform. Based on the principle of POCS, an iterative procedure is proposed to extract information hidden in a group of low resolution images to update the corresponding high frequency band of the reference image, thus augmenting the individual low-resolution image to a high resolution image. The simulation results show that the new proposed algorithm is effective in constructing high-resolution medical images. View full abstract»

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  • The design of PCI Express for future communication platform

    Publication Year: 2004 , Page(s): 734 - 739
    Cited by:  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (471 KB) |  | HTML iconHTML  

    We design a PCI Express controller for endpoint (APCE). APCE supports the full functionality of the transaction layer and data link layer of PCI Express. We propose an efficient buffer management scheme for APCE to obey the replay mechanism and it can dynamically adjust the size of a replay buffer space. We employ 80C51 to manage the designed functional blocks in APCE effectively, and implement the real-time OS, MicroC/OS II, on 80C51. We also code software under a real time environment. This coded software covers supporting the replay mechanism, checking and generating error messages, processing TLP (transaction layer packet) acknowledgment, and management for exchanging flow control. To verify APCE, we built a test bench including behavioral models of host bridge, local master, and local slave. We also propose an effective verification for compliance and corner case testing when using a behavioral reference model of APCE, random generator, and compare engine. View full abstract»

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  • A study on the regulations concerning base stations for next-generation mobile communications networks in Korea

    Publication Year: 2004 , Page(s): 717 - 722
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (389 KB) |  | HTML iconHTML  

    Mobile communications services, which offer one way to realize the informed society of the 21st century, have developed rapidly worldwide. With the commercialization of CDMA 2000-1× late in 2000, a high-speed wireless Internet, based on a mobile communication network, appeared in Korea. This will develop into the next-generation of mobile communications (4G) with faster transmission of increased volumes of data in the future. The new cell layout requires the cellular configuration of 4G and the services 4G have to offer a more universal mobile communication service and helps to reduce the digital divide. We would need legislation with respect to base stations and for building the mobile communication networks, as well as the optimization of mobile communication systems. In this study, in order to provide 4G, I examined and analyzed the current laws related to licensing and operating a mobile communication base station in Korea. View full abstract»

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  • Personal identification using footstep detection

    Publication Year: 2004 , Page(s): 43 - 47
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (339 KB) |  | HTML iconHTML  

    Footsteps, with different shoes of heels, sneakers, leathers or even bare footed, will appear in different grounds of concrete, wood, etc. To recognize human footsteps is not only the need of surveillance but the home service center also can use this information to understand the motion of people with techniques of sound localization, etc. Thus, if a footstep is discriminable, the application to various fields can be considered. In this paper, the feature extraction of a footstep is investigated. We focused on the mel-cepstrum analysis, walking interval, and the degree of similarity of spectrum envelope. It is shown for personal identification that the performance of the proposed method is effective. View full abstract»

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  • A secure mobile IP authentication based on identification protocol

    Publication Year: 2004 , Page(s): 709 - 712
    Cited by:  Papers (1)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (295 KB) |  | HTML iconHTML  

    Mobile IP, which was designed at the working group of IETF, intended to enable nodes to move from one IP subnet to another. That is, it can support node mobility across heterogeneous networks. For this mobility support, a mobile node (MN) must achieve registration at a home agent (HA) when the MN is away from home. In this article, we propose a mobile IP authentication that is based on an identification scheme using a one-way function. It ensures a secure mobile IP authentication against replay attack and man-in-the-middle attack. Furthermore, its implementation is expected to be efficient, since it does not use any public key cryptography operations. View full abstract»

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  • An image quality control technique for the ROI coding in JPEG2000 and its application to the motion pictures

    Publication Year: 2004 , Page(s): 356 - 361
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (411 KB) |  | HTML iconHTML  

    In JPEG2000 coding, SNR scalability on the basis of regions of interests (ROI) is considered as one of the main features. However, the image quality of the background region is severely degraded in this case. This paper proposes an image control technique for ROI coding with consideration of SNR scalability by separating the ROI coding and the rate-control operation. The proposed method can improve the image quality for the background region, without severely degrading the image quality of the ROI. An application of the proposed technique to motion pictures is also considered. View full abstract»

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  • A medical EEG/video multimedia content description system

    Publication Year: 2004 , Page(s): 592 - 595
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (344 KB) |  | HTML iconHTML  

    Neurological diagnostic information management for clinical applications requires significant collaboration among clinicians and integration of data in different forms, such as textual records, monitoring video, recorded physiological waveforms, and diagnostic images. In medical settings, these multimedia data are often generated in large amounts and are routinely compared and examined. In order to manage this type of information efficiently, an advanced information management system is investigated which handles not only the traditional textual and pictorial information, but also manages audio and video. This information system utilizes the newly developed MPEG-7 standard (multimedia content description interface standard) which provides a context-based platform for our application. In addition, MPEG-7 allows medical information to be accessed remotely and securely through the Internet. View full abstract»

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  • Variable exponent nonlinearly processed correlation algorithm: analysis and simulations

    Publication Year: 2004 , Page(s): 313 - 316
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (288 KB) |  | HTML iconHTML  

    A new algorithm for adaptive filters, named variable exponent nonlinearly processed correlation algorithm (VE-NPCA), is proposed and studied. The exponent, r, in the "rth power function" of the correlation between the error and the filter input is adaptively controlled by an estimate of the error power. The variable exponent achieves a significant improvement in the convergence rate of the sign-sign algorithm that is known to be highly robust against disturbances but considerably slow in convergence. The results of simulations for some examples prove the effectiveness of the proposed VE-NPCA. Analysis yields a set of difference equations for calculating the theoretical convergence curves which appear to be in good agreement with the simulated ones. View full abstract»

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  • A proposal of blind equalization for nonlinear transmission channel

    Publication Year: 2004 , Page(s): 137 - 140
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (235 KB) |  | HTML iconHTML  

    This paper presents a new blind equalization for nonlinear transmission channel. Conventional algorithms assume linear channel, and estimate reverse system of channel using linear equalizer. But, on biomedical signals or sound signals, channels are almost nonlinear, so the performance of blind equalization algorithms deteriorates. Then, we propose blind equalization using Volterra-filter for nonlinear channels. We confirm the validity of the proposed algorithm through computer simulation. View full abstract»

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  • Capacity reduction of the IS-95 reverse link in the presence of interference from adjacent WCDMA networks in the 850 MHz bands [3G communications]

    Publication Year: 2004 , Page(s): 690 - 695
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (365 KB) |  | HTML iconHTML  

    This paper focuses on the capacity reduction of an IS-95 reverse link in the presence of a wideband code-division multiple access (WCDMA) deployed at an adjacent frequency band in the 850 MHz bands. The models used in the simulation are described firstly, then the principle of the network interference analysis is discussed in detail. Furthermore, simulation results are provided and analyzed. Finally, the function expressions between capacity loss and ACIR are derived. The adjacent channel interference analysis method used in the paper can be utilized for frequency allocation, WCDMA network planning, and system design of mobile telecommunication systems. View full abstract»

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  • Maximum likelihood detection of I/Q imbalance signal with self-organized clustering assistance

    Publication Year: 2004 , Page(s): 660 - 664
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (318 KB) |  | HTML iconHTML  

    For the detection of a quadrature phase shift keying (QPSK) modulated signal, in the presence of I/Q imbalance, maximum likelihood detection with self-organized clustering assistance (ML-SOCA) is proposed in this paper. In modulation techniques employed in a quadrature receiver, gain and phase imbalance between I and Q channel filters and amplifiers can cause asymmetry and rotation in signal constellations, then the probability of error moves far away from the ideal point. The self-organized clustering system is used to learn the behavior of the received signals and estimate the new decision boundaries that are fed to the maximum likelihood detector. Simulation results were obtained with Matlab. View full abstract»

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