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  • Extraction of High-Resolution Frame from Low-Resolution Video Sequence Using Region-Based Motion Estimation

    Osama Ahmed OMER  Toshihisa TANAKA  

     
    PAPER-Digital Signal Processing

      Vol:
    E93-A No:4
      Page(s):
    742-751

    The problem of recovering a high-resolution frame from a sequence of low-resolution frames is considered. In general, video frames cannot be related through global parametric transformation due to the arbitrary individual pixel movement between frame pairs. To overcome this problem, we propose to employ region-matching technique for motion estimation with a modified model for frame alignment. To do that, the reference frame is segmented into arbitrary-shaped regions which are further matched with that of the other frames. Then, the frame alignment is accomplished by optimizing the cost function that consists of L1-norm of the difference between the interpolated low-resolution (LR) frames and the simulated LR frames. The experimental results demonstrate that using region matching in motion estimation step with the modified alignment model works better than other motion models such as affine, block matching, and optical flow motion models.

  • Closed Form Solutions to L2-Sensitivity Minimization Subject to L2-Scaling Constraints for Second-Order State-Space Digital Filters with Real Poles

    Shunsuke YAMAKI  Masahide ABE  Masayuki KAWAMATA  

     
    PAPER-Digital Signal Processing

      Vol:
    E93-A No:2
      Page(s):
    476-487

    This paper proposes closed form solutions to the L2-sensitivity minimization subject to L2-scaling constraints for second-order state-space digital filters with real poles. We consider two cases of second-order digital filters: distinct real poles and multiple real poles. The proposed approach reduces the constrained optimization problem to an unconstrained optimization problem by appropriate variable transformation. We can express the L2-sensitivity by a simple linear combination of exponential functions and formulate the L2-sensitivity minimization problem by a simple polynomial equation. As a result, L2-sensitivity is expressed in closed form, and its minimization subject to L2-scaling constraints is achieved without iterative calculations.

  • Robust Toponym Resolution Based on Surface Statistics

    Tomohisa SANO  Shiho Hoshi NOBESAWA  Hiroyuki OKAMOTO  Hiroya SUSUKI  Masaki MATSUBARA  Hiroaki SAITO  

     
    PAPER-Unknown Word Processing

      Vol:
    E92-D No:12
      Page(s):
    2313-2320

    Toponyms and other named entities are main issues in unknown word processing problem. Our purpose is to salvage unknown toponyms, not only for avoiding noises but also providing them information of area candidates to where they may belong. Most of previous toponym resolution methods were targeting disambiguation among area candidates, which is caused by the multiple existence of a toponym. These approaches were mostly based on gazetteers and contexts. When it comes to the documents which may contain toponyms worldwide, like newspaper articles, toponym resolution is not just an ambiguity resolution, but an area candidate selection from all the areas on Earth. Thus we propose an automatic toponym resolution method which enables to identify its area candidates based only on their surface statistics, in place of dictionary-lookup approaches. Our method combines two modules, area candidate reduction and area candidate examination which uses block-unit data, to obtain high accuracy without reducing recall rate. Our empirical result showed 85.54% precision rate, 91.92% recall rate and .89 F-measure value on average. This method is a flexible and robust approach for toponym resolution targeting unrestricted number of areas.

  • A 48 Cycles/MB H.264/AVC Deblocking Filter Architecture for Ultra High Definition Applications

    Dajiang ZHOU  Jinjia ZHOU  Jiayi ZHU  Satoshi GOTO  

     
    PAPER-Embedded, Real-Time and Reconfigurable Systems

      Vol:
    E92-A No:12
      Page(s):
    3203-3210

    In this paper, a highly parallel deblocking filter architecture for H.264/AVC is proposed to process one macroblock in 48 clock cycles and give real-time support to QFHD@60 fps sequences at less than 100 MHz. 4 edge filters organized in 2 groups for simultaneously processing vertical and horizontal edges are applied in this architecture to enhance its throughput. While parallelism increases, pipeline hazards arise owing to the latency of edge filters and data dependency of deblocking algorithm. To solve this problem, a zig-zag processing schedule is proposed to eliminate the pipeline bubbles. Data path of the architecture is then derived according to the processing schedule and optimized through data flow merging, so as to minimize the cost of logic and internal buffer. Meanwhile, the architecture's data input rate is designed to be identical to its throughput, while the transmission order of input data can also match the zig-zag processing schedule. Therefore no intercommunication buffer is required between the deblocking filter and its previous component for speed matching or data reordering. As a result, only one 2464 two-port SRAM as internal buffer is required in this design. When synthesized with SMIC 130 nm process, the architecture costs a gate count of 30.2 k, which is competitive considering its high performance.

  • High Gain and Wide Range Time Amplifier Using Inverter Delay Chain in SR Latches

    Jaejun LEE  Sungho LEE  Yonghoon SONG  Sangwook NAM  

     
    LETTER-Electronic Circuits

      Vol:
    E92-C No:12
      Page(s):
    1548-1550

    This paper presents a time amplifier design that improves time resolution using an inverter chain delay in SR latches. Compared with the conventional design, the proposed time amplifier has better characteristics such as higher gain, wide range, and small die size. It is implemented using 0.13 µm standard CMOS technology and the experimental results agree well with the theory.

  • A Novel Bandelet-Based Image Inpainting

    Kuo-Ming HUNG  Yen-Liang CHEN  Ching-Tang HSIEH  

     
    PAPER-Image Coding and Processing

      Vol:
    E92-A No:10
      Page(s):
    2471-2478

    This paper proposes a novel image inpainting method based on bandelet transform. This technique is based on a multi-resolution layer to perform image restoration, and mainly utilizes the geometrical flow of the neighboring texture of the damaged regions as the basis of restoration. By performing the warp transform with geometrical flows, it transforms the textural variation into the nearing domain axis utilizing the bandelet decomposition method to decompose the non-relative textures into different bands, and then combines them with the affine search method to perform image restoration. The experimental results show that the proposed method can simplify the complexity of the repair decision method and improve the quality of HVS, and thus, repaired results to contain the image of contour of high change, and in addition, offer a texture image of high-frequency variation. These repair results can lead to state-of-the-art results.

  • Analysis and Design of a Reflection-Cancelling Transverse Slot-Pair Array with Grating-Lobe Suppressing Baffles

    Takehito SUZUKI  Jiro HIROKAWA  Makoto ANDO  

     
    PAPER-Antennas and Propagation

      Vol:
    E92-B No:10
      Page(s):
    3236-3242

    This paper presents the analysis and design of a reflection-cancelling transverse slot-pair array antenna with baffles by using the Spectrum of Two-Dimensional Solutions (S2DS) method. For the transverse slot array, the slot spacings with more than one free-space wavelength cause the grating-lobes. The baffles suppress the grating-lobes effectively. A one-dimensional slot array is extracted from the 2D array with in-phase excitation by assuming periodicity in the transversal direction. The uniform excitation over the finite array is synthesized iteratively to demonstrate the fast and accurate results by S2DS. A unit design model with the baffles is introduced to determine the initial parameters of the slot-pairs, which greatly accelerate the iterations process. Experiments at 25.3 GHz demonstrate the suppression of the grating lobes to the level less than -20.0 dB and also the good uniformity of the aperture field distribution.

  • A New Approach to Rotation Invariant Texture Analysis Based on Radon Transform

    Mehdi CHEHEL AMIRANI  Ali A. BEHESHTI SHIRAZI  

     
    PAPER-Image Recognition, Computer Vision

      Vol:
    E92-D No:9
      Page(s):
    1736-1744

    In this paper, we propose a new approach to rotation invariant texture analysis. This method uses the Radon transform with some considerations in direction estimation of textural images. Furthermore, it utilizes the information obtained from the number of peaks in the variance array of the Radon transform as a realty feature. The textural features are then generated after rotation of texture along principle direction. Also, to eliminating the introduced error due to rotation of texture, a simple technique is presented. Experimental results on a set of images from the Brodatz album show a good performance achieved by the proposed method in comparison with some recent texture analysis methods.

  • A 0.31 pJ/Conversion-Step 12-Bit 100 MS/s 0.13 µm CMOS A/D Converter for 3G Communication Systems

    Young-Ju KIM  Kyung-Hoon LEE  Myung-Hwan LEE  Seung-Hoon LEE  

     
    PAPER-Electronic Circuits

      Vol:
    E92-C No:9
      Page(s):
    1194-1200

    This work describes a 12-bit 100 MS/s 0.13 µm CMOS ADC for 3G wireless communication systems such as two-carrier W-CDMA applications. The proposed ADC employs a four-step pipeline architecture to optimize power consumption and chip area at the target resolution and sampling rate. Area-efficient gate-bootstrapped sampling switches of the input SHA maintain high signal linearity over the Nyquist rate even at a 1.0 V supply. The cascode compensation using a low-impedance feedback path in two-stage amplifiers of the SHA and MDACs achieves the required conversion speed and phase margin with less power consumption and area compared to the Miller compensation. A low-glitch dynamic latch in the sub-ranging flash ADCs reduces kickback noise referred to the input of comparator by isolating the pre-amplifier from the regeneration latch output. The proposed on-chip current and voltage references are based on triple negative TC circuits. The prototype ADC in a 0.13 µm 1P8M CMOS technology demonstrates the measured DNL and INL within 0.38LSB and 0.96LSB at 12-bit, respectively. The ADC shows a maximum SNDR and SFDR of 64.5 dB and 78.0 dB at 100 MS/s, respectively. The ADC with an active die area of 1.22 mm2 consumes 42.0 mW at 100 MS/s and a 1.2 V supply, corresponding to a figure-of-merit of 0.31 pJ/conversion-step.

  • Graph Cuts Segmentation by Using Local Texture Features of Multiresolution Analysis

    Keita FUKUDA  Tetsuya TAKIGUCHI  Yasuo ARIKI  

     
    PAPER-Image Recognition, Computer Vision

      Vol:
    E92-D No:7
      Page(s):
    1453-1461

    This paper proposes an approach to image segmentation using Iterated Graph Cuts based on local texture features of wavelet coefficients. Using Haar Wavelet based Multiresolution Analysis, the low-frequency range (smoothed image) is used for the n-link and the high-frequency range (local texture features) is used for the t-link along with the color histogram. The proposed method can segment an object region having not only noisy edges and colors similar to the background, but also heavy texture change. Experimental results illustrate the validity of our method.

  • Key Enabling Physical Layer Technologies for LTE-Advanced

    Meilong JIANG  Narayan PRASAD  Yan XIN  Guosen YUE  Amir KHOJASTEPOUR  Le LIU  Takamichi INOUE  Kenji KOYANAGI  Yoshikazu KAKURA  

     
    PAPER

      Vol:
    E92-B No:5
      Page(s):
    1751-1759

    The 3GPP Long Term Evolution Advanced (LTE-A) system, as compared to the LTE system, is anticipated to include several new features and enhancements, such as the usage of channel bandwidth beyond 20 MHz (up 100 MHz), higher order multiple input multiple output (MIMO) for both downlink and uplink transmissions, larger capacity especially for cell edge user equipment, and voice over IP (VoIP) users, and wider coverage and etc. This paper presents some key enabling technologies including flexible uplink access schemes, advanced uplink MIMO receiver designs, cell search, adaptive hybrid ARQ, and multi-resolution MIMO precoding, for the LTE-A system.

  • HSWIS: Hierarchical Shrink-Wrapped Iso-Surface Algorithm

    Young-Kyu CHOI  Eun-Jin PARK  

     
    LETTER-Computer Graphics

      Vol:
    E92-D No:4
      Page(s):
    757-760

    A new hierarchical isosurface reconstruction scheme from a set of tomographic cross sectional images is presented. From the input data, we construct a hierarchy of volume, called the volume pyramid, based on a 3D dilation filter. After extracting the base mesh from the volume at the coarsest level by the cell-boundary method, we iteratively fit the mesh to the isopoints representing the actual isosurface of the volume. The SWIS (Shrink-wrapped isosurface) algorithm is adopted in this process, and a mesh subdivision scheme is utilized to reconstruct fine detail of the isosurface. According to experiments, our method is proved to produce a hierarchical isosurface which can be utilized by various multiresolution algorithms such as interactive visualization and progressive transmission.

  • Transition Edge Sensor-Energy Dispersive Spectrometer (TES-EDS) and Its Applications Open Access

    Keiichi TANAKA  Akikazu ODAWARA  Atsushi NAGATA  Yukari BABA  Satoshi NAKAYAMA  Shigenori AIDA  Toshimitsu MOROOKA  Yoshikazu HOMMA  Izumi NAKAI  Kazuo CHINONE  

     
    INVITED PAPER

      Vol:
    E92-C No:3
      Page(s):
    334-340

    The Transition Edge Sensor (TES)-Energy Dispersive Spectrometer (EDS) is an X-ray detector with high-energy resolution (12.8 eV). The TES can be mounted to a scanning electron microscope (SEM). The TES-EDS is based on a cryogen-free dilution refrigerator. The high-energy resolution enables analysis of the distribution of various elements in samples under low acceleration voltage (typically under 5 keV) by using K-lines of light elements and M lines of heavy elements. For example, the energy of the arsenic L line differs from the magnesium K line by 28 eV. When used to analyze the spore of the Pteris vittata L plant, the TES-EDS clearly reveals a different distribution of As and Mg in the micro region of the plant. The TES-EDS with SEM yields detailed information about the distribution of multi-elements in a sample.

  • A Dynamic Framed Slotted ALOHA Algorithm Using Collision Factor for RFID Identification

    Seung Sik CHOI  Sangkyung KIM  

     
    LETTER-Network

      Vol:
    E92-B No:3
      Page(s):
    1023-1026

    In RFID systems, collision resolution is a significant issue in fast tag identification. This letter presents a dynamic frame-slotted ALOHA algorithm that uses a collision factor (DFSA-CF). This method enables fast tag identification by estimating the next frame size with the collision factor in the current frame. Simulation results show that the proposed method reduces slot times Required for RFID identification. When the number of tags is larger than the frame size, the efficiency of the proposed method is greater than those of conventional algorithms.

  • An Adjustable Scheduling Algorithm for Multi-User MIMO Systems

    Jaehong KIM  Sangjae LEE  Sehun KIM  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E92-B No:2
      Page(s):
    527-532

    Multiple Input Multiple Output (MIMO) represents a highly promising technique for 4G communication networks as it uses multiple antennas at the transmitter and receiver to improve the reliability of transmissions and to provide a high data rate. This paper introduces an adjustable scheduling algorithm for multi-user MIMO systems that can provide an advantageous trade-off solution between throughput maximization and fair resource allocation among users. Specifically, our algorithm is proposed as a solution to system requirement issues through the flexible control of fairness factors.

  • Name-Based Address Mapping for Virtual Private Networks

    Peter SURANYI  Yasushi SHINJO  Kazuhiko KATO  

     
    PAPER-Internet

      Vol:
    E92-B No:1
      Page(s):
    200-208

    IPv4 private addresses are commonly used in local area networks (LANs). With the increasing popularity of virtual private networks (VPNs), it has become common that a user connects to multiple LANs at the same time. However, private address ranges for LANs frequently overlap. In such cases, existing systems do not allow the user to access the resources on all LANs at the same time. In this paper, we propose name-based address mapping for VPNs, a novel method that allows connecting to hosts through multiple VPNs at the same time, even when the address ranges of the VPNs overlap. In name-based address mapping, rather than using the IP addresses used on the LANs (the real addresses), we assign a unique virtual address to each remote host based on its domain name. The local host uses the virtual addresses to communicate with remote hosts. We have implemented name-based address mapping for layer 3 OpenVPN connections on Linux and measured its performance. The communication overhead of our system is less than 1.5% for throughput and less than 0.2 ms for each name resolution.

  • Analysis of Ground Wave Propagation over Land-to-Sea Mixed-Path by Using Equivalent Current Source on Aperture Plane

    Toru KAWANO  Keiji GOTO  Toyohiko ISHIHARA  

     
    PAPER

      Vol:
    E92-C No:1
      Page(s):
    46-54

    In this paper, we have obtained the integral representation for the ground wave propagation over land-to-sea mixed-paths which uses the equivalent current source on an aperture plane. By extending the integral to the complex plane and deforming the integration path into the steepest descent path, we have derived a simple integral representation for the mixed-path ground wave propagation. We have also derived the hybrid numerical and asymptotic representation for an efficient calculation of the ground wave and for easy understanding of the diffraction phenomena. By using the method of the stationary phase applicable uniformly as the stationary phase point approaches the endpoint, we have derived the high-frequency asymptotic solution for the ground wave propagation over the mixed-path. We have confirmed the validity of the various representations by comparing both with the conventional mixed-path theory and with the experimental results performed in Kanto areas including the sea near Tokyo bay. By examining the asymptotic solution in detail, we have found out the cause or the mechanism of the recovery effect occurring on the portion of the sea over the land-to-sea mixed-path.

  • Analysis and Uniform Design of a Single-Layer Slotted Waveguide Array Antenna with Baffles

    Takehito SUZUKI  Jiro HIROKAWA  Makoto ANDO  

     
    PAPER-Devices/Circuits for Communications

      Vol:
    E92-B No:1
      Page(s):
    150-158

    This paper presents the formulation for the evaluation of external coupling in the alternating-phase feed single-layer slotted waveguide array antenna with baffles by using the Spectrum of Two-Dimensional Solutions (S2DS) method. A one-dimensional slot array is extracted from the array by assuming the periodicity in transversal direction and introducing the perfect electric conductors in the external region. The uniform excitation over the finite array is synthesized iteratively to demonstrate the fast and accurate results by S2DS. A unit design model with the baffles is introduced to determine the initial parameters of the slot pair which accelerate the iteration. Experiment at 25.3 GHz demonstrates good uniformity of the aperture field distribution as well as the effects of the baffles. The directivity is 32.7 dB which corresponds to the aperture efficiency 90.5% and the reflection is below -15.0 dB over 1.3 GHz.

  • Regularization Super-Resolution with Inaccurate Image Registration

    Ju LIU  Hua YAN  Jian-de SUN  

     
    PAPER-Image Processing and Video Processing

      Vol:
    E92-D No:1
      Page(s):
    59-68

    Considering the inaccuracy of image registration, we propose a new regularization restoration algorithm to solve the ill-posed super-resolution (SR) problem. Registration error is used to obtain cross-channel error information caused by inaccurate image registration. The registration error is considered as the noise mean added into the within-channel observation noise which is known as Additive White Gaussian Noise (AWGN). Based on this consideration, two constraints are regulated pixel by pixel within the framework of Miller's regularization. Regularization parameters connect the two constraints to construct a cost function. The regularization parameters are estimated adaptively in each pixel in terms of the registration error and in each observation channel in terms of the AWGN. In the iterative implementation of the proposed algorithm, sub-sampling operation and sampling aliasing in the detector model are dealt with respectively to make the restored HR image approach the original one further. The transpose of the sub-sampling operation is implemented by nearest interpolation. Simulations show that the proposed regularization algorithm can restore HR images with much sharper edges and greater SNR improvement.

  • Transitional Dynamics and Quasi-Periodic Solution Observed in Two Asymmetrical Coupled Oscillators

    Kuniyasu SHIMIZU  Tetsuro ENDO  Takuya YOSHIMURA  

     
    PAPER-Nonlinear Problems

      Vol:
    E92-A No:1
      Page(s):
    270-278

    In this paper, we investigate the transitional dynamics and quasi-periodic solution appearing after the Saddle-Node (SN) bifurcation of a periodic solution in an inductor-coupled asymmetrical van der Pol oscillators with hard-type nonlinearity. In particular, we elucidate, by investigating global bifurcation of unstable manifold (UM) of saddles, that transitional dynamics and quasi-periodic solution after the SN bifurcation appear based on different structure of UM.

161-180hit(404hit)