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[Keyword] SI(16314hit)

11961-11980hit(16314hit)

  • Performance Analysis of IP Datagram Transmission Delay in MPLS: Impact of Both Number and Bandwidth of LSPs of Layer 2

    Shogo NAKAZAWA  Hitomi TAMURA  Kenji KAWAHARA  Yuji OIE  

     
    PAPER

      Vol:
    E85-B No:1
      Page(s):
    165-172

    LSR (Label Switching Router)s in MPLS (Multiprotocol Label Switching) networks map arriving IP flows into some labels on Layer 2 switching fabric and establish LSP (Label Switching Path)s. By using LSPs, LSRs not only transmit IP datagrams fast by cut-through mechanism, but also solve traffic engineering issue to optimize the delay of some IP datagram flows. So far, we have analyzed the performance of LSR focusing only on the maximum number of LSPs which can be set on Layer 2. In this paper, we will also consider the bandwidth allocated to each LSP and analyze the IP datagram transmission delay and the cut-through rate of LSR. We suppose the label mapping method as the data-driven scheme in the analytical model, so that the physical bandwidth of LSR is shared by both the default LSP for hop-by-hop transmission and the cut-through LSPs. Thus, we will investigate the impact of the bandwidth allocation among these LSPs on the performance.

  • Functional Mapping of Optically Detected Neural Activity onto a Standardized Cortical Structure of Rodent Barrels

    Ichiro TAKASHIMA  Riichi KAJIWARA  Toshio IIJIMA  

     
    PAPER-Optical Imaging

      Vol:
    E85-D No:1
      Page(s):
    143-151

    The concept of a "standardized brain" is familiar in modern functional neuro-imaging techniques including PET and fMRI, but it has never been adopted for optical imaging studies that deal with a regional cortical area rather than the whole brain. In this paper, we propose a "standardized barrel cortex" for rodents, and present a method for mapping optically detected neural activity onto the standard cortex. The standard cortex is defined as a set of simple cortical columns, which are modeled on the cytoarchitectonic patterns of cell aggregates in cortical layer IV of the barrel cortex. Referring to its underlying anatomical structure, the method warps the surface image of individual cortices to fit the standard cortex. The cortex is warped using a two-dimensional free-form deformation technique with direct manipulation. Since optical imaging provides a map of neural activity on the cortical surface, the warping consequently remaps it on the standard cortex. Data presented in this paper show that somatosensory evoked neural activity is successfully represented on the standardized cortex, suggesting that the combination of optical imaging with our method is a promising approach for investigating the functional architecture of the cortex.

  • A Temperature- and Supply-Insensitive Fully On-Chip 1 Gb/s CMOS Open-Drain Output Driver for High-Bandwidth DRAMs

    Young-Hee KIM  Jong-Doo JOO  Jae-Kyung WEE  Jin-Yong CHUNG  Young-Soo SOHN  Hong-June PARK  

     
    PAPER-Electronic Circuits

      Vol:
    E85-C No:1
      Page(s):
    204-211

    A fully on-chip open-drain CMOS output driver was designed for high bandwidth DRAMs, such that its output voltage swing was insensitive to the variations of temperature and supply voltage. An auto refresh signal was used to update the contents of the current control register, which determined the transistors to be turned-on among the six binary-weighted transistors of an output driver. Because the auto refresh signal is available in DRAM chips, the output driver of this work does not require any external signals to update the current control register. During the time interval while the update is in progress, a negative feedback loop is formed to maintain the low level output voltage (VOL) to be equal to the reference voltage (VOL.ref) which is generated by a low-voltage bandgap reference circuit. Test results showed the successful operation at the data rate up to 1 Gb/s. The worst-case variations of VOL.ref and VOL of the proposed output driver were measured to be 2.5% and 7.5% respectively within a temperature range of 20 to 90 and a supply voltage range of 2.25 V to 2.75 V, while the worst-case variation of VOL of the conventional output driver was measured to be 24% within the same ranges of temperature and supply voltage.

  • A Fast Full Search Motion Estimation Algorithm Using Sequential Rejection of Candidates from Multilevel Decision Boundary

    Jong Nam KIM  ByungHa AHN  

     
    LETTER-Multimedia Systems

      Vol:
    E85-B No:1
      Page(s):
    355-358

    We propose a new and fast full search (FS) motion estimation algorithm for video coding. The computational reduction comes from sequential rejection of impossible candidates with derived formula and subblock norms. Our algorithm reduces more the computations than the recent fast full search (FS) motion estimation algorithms.

  • Edge-Based Image Synthesis Model and Its Synthesis Function Design by the Wavelet Transform

    Makoto NAKASHIZUKA  Hidetoshi OKAZAKI  Hisakazu KIKUCHI  

     
    PAPER-Digital Signal Processing

      Vol:
    E85-A No:1
      Page(s):
    210-221

    In this paper, a new image synthesis model based on a set of wavelet bases is proposed. In the proposed model, images are approximated by the sum of synthesis functions that are translated to image edge positions. By applying the proposed model to sketch-based image coding, no iterative image recovery procedure is required for image decoding. In the design of the synthesis functions, we define the synthesis functions as a linear combination of wavelet bases. The coefficients for wavelet bases are obtained from an iterative procedure. The vector quantization is applied to the vectors of the coefficients to limit the number of the synthesis functions. We apply the proposed synthesis model to the sketch-based image coding. Image coding experiments by eight synthesis functions and a comparison with the orthogonal transform methods are also given.

  • Concurrent Gate Re-Sizing and Buffer Insertion to Reduce Glitch Power in CMOS Digital Circuit Design

    Sungjae KIM  Hyungwoo LEE  Juho KIM  

     
    PAPER-VLSI Design Technology and CAD

      Vol:
    E85-A No:1
      Page(s):
    234-240

    We present an efficient heuristic algorithm to reduce glitch power dissipation in CMOS digital circuits. In this paper, gate sizing is classified into three types and the buffer insertion is classified into two types. The proposed algorithm combines three types of gate sizing and two types of buffer insertion into a single optimization process to maximize the glitch reduction. The efficiency of our algorithm has been verified on LGSynth91 benchmark circuits with a 0.5 µm standard cell library. Experimental results show an average of 69.98% glitch reduction and 28.69% power reduction that are much better than those of gate sizing and buffer insertion performed independently.

  • Asynchronous Multirate Real-Time Scheduling for Programmable DSPs

    Ichiro KURODA  

     
    PAPER-VLSI Design Technology and CAD

      Vol:
    E85-A No:1
      Page(s):
    241-247

    A novel scheduling method for asynchronous multirate/multi-task processing by programmable digital signal processors (DSPs) has been developed. This mixed scheduling method combines static and dynamic scheduling, and avoids runtime overheads due to interrupts in context switching to realizes asynchronous multirate systems. The processing delay introduced when using static scheduling with static buffering is avoided by introducing deadline scheduling in the static schedule design. In the developed software design system, a block-diagram description language is extended to describe asynchronous multi-task processing. The scheduling method enables asynchronous multirate processing, such as arbitrary-sampling-ratio rate conversion, asynchronous interface, and multimedia applications, to be efficiently realized by programmable DSPs.

  • 2D Photonic Crystal Surface-Emitting Laser Using Triangular-Lattice Structure

    Susumu NODA  Masahiro IMADA  

     
    INVITED PAPER

      Vol:
    E85-C No:1
      Page(s):
    45-51

    A 2D photonic crystal surface-emitting laser using a triangular lattice is developed, and current-injected lasing oscillation is demonstrated. From consideration of the Bragg diffraction condition in the 2D triangular-lattice structure, it is shown that the 2D coupling phenomenon occurs in the structure. As a result of the 2D periodicity of the structure, the longitudinal mode and lateral mode can be controlled, and stable single-mode oscillation is possible over a large 2D area. The lasing mode of the structure is analyzed by calculating the photonic band diagram by the 2D plane-wave expansion method, and we show that four band edges at which the lasing oscillation can occur exist at the Γ point. Current-injected lasing oscillation is successfully demonstrated at room temperature under pulsed conditions. The threshold current density is 3.2 kA/cm2 and the lasing wavelength is 1.285 µm. From the near-field and far-field patterns, it is shown that large-area 2D (diameter 480 µm) lasing oscillation occurs in the device and the divergence angle is very narrow (less than 1.8). We also demonstrate the correspondence between the measured lasing wavelengths and calculated band diagram by comparing the polarization characteristics with the calculated distribution of the electromagnetic field. The results indicate that 2D coherent lasing oscillation occurs due to the multi-directional coupling effect in the 2D photonic crystal. Finally, we show that the polarization patterns of the lasers can be controlled by introducing artificial lattice defects from the theoretical calculation.

  • A Lossless Image Compression for Medical Images Based on Hierarchical Sorting Technique

    Atsushi MYOJOYAMA  Tsuyoshi YAMAMOTO  

     
    PAPER-Image Processing

      Vol:
    E85-D No:1
      Page(s):
    108-114

    We propose new lossless medical image compression method based on hierarchical sorting technique. Hierarchical sorting is a technique to achieve high compression ratio by detecting the regions where image pattern varies abruptly and sorting pixel order by its value to increase predictability. In this method, we can control sorting accuracy along with size and complexity. As the result, we can reduce the sizes of the permutation-tables and reuse the tables to other image regions. Comparison using experimental implementation of this method shows better performance for medical image set measured by X-ray CT and MRI instruments where similar sub-block patterns appear frequently. This technique applies quad-tree division method to divide an image to blocks in order to support progressive decoding and fast preview of large images.

  • Software Creation: Clich as Intermediate Knowledge in Software Design

    Hassan ABOLHASSANI  Hui CHEN  Zenya KOONO  

     
    PAPER-Software Engineering

      Vol:
    E85-D No:1
      Page(s):
    221-232

    This paper reports on clich and related mechanisms appearing in a process of human design of software. During studies on human design knowledge, the authors found frequent instance of same pattern of detailing, named clich. In our study, clich is an intermediate level of design knowledge, during a hierarchical detailing step, residing in between simple reuse and creation by micro design rules, which have already been reported. These three kinds of design knowledge are of various types and have different complexities. Discussions on them, focusing on clich type, with procedures of formation of a simple clich skeleton and generation of a clich are given. The studies show a working model of Zipf's principle, and are some trials to reveal a more detail of human designs.

  • Delegation Chains Secure up to Constant Length

    Masayuki ABE  Tatsuaki OKAMOTO  

     
    PAPER

      Vol:
    E85-A No:1
      Page(s):
    110-116

    In this paper we discuss how one can delegate his power to authenticate or sign documents to others who, again, can delegate the power to someone else. A practical cryptographic solution would be to issue a certificate that consists of one's signature. The final verifier checks verifies the chain of these certificates. This paper provides an efficient and provably secure scheme that is suitable for such a delegation chain. We prove the security of our scheme against an adaptive chosen message attack in the random oracle model. Though our primary application would be agent systems where some agents work on behalf of a user, some other applications and variants will be discussed as well. One of the variants enjoys a threshold feature whereby one can delegate his power to a group so that they have less chance to abuse their power. Another application is an identity-based signature scheme that provides faster verification capability and less communication complexity compared to those provided by existing certificate-based public key infrastructure.

  • Ultrahigh-Speed OTDM Transmission beyond 1 Tera Bit-Per-Second Using a Femtosecond Pulse Train

    Masataka NAKAZAWA  Takashi YAMAMOTO  Koichi Robert TAMURA  

     
    INVITED PAPER-OTDM Transmission System, Optical Regeneration and Coding

      Vol:
    E85-C No:1
      Page(s):
    117-125

    Progress on a single wavelength channel OTDM terabit/s transmission is described. In particular, we focus on 1.28 Tbit/s OTDM transmission over 70 km which we realized recently. A pre-chirping technique using a high speed phase modulator is emphasized to simultaneously compensate for third- and fourth-order dispersion. The input pulse width was 380 fs, and the pulse broadening after a 70 km transmission was as small as 20 fs. All 128 channels time-division-demultiplexed to 10 Gbit/s had a bit error rate of less than 110-9, in which we employed a lot of new technique for pulse generation, dispersion compensation and demultiplexing. These techniques help pave the path for OTDM technology of the 21 century.

  • Steady State Analysis of the RED Gateway: Stability, Transient Behavior, and Parameter Setting

    Hiroyuki OHSAKI  Masayuki MURATA  

     
    PAPER

      Vol:
    E85-B No:1
      Page(s):
    107-115

    Several gateway-based congestion control mechanisms have been proposed to support an end-to-end congestion control mechanism of TCP (Transmission Control Protocol). One of promising gateway-based congestion control mechanisms is a RED (Random Early Detection) gateway. Although effectiveness of the RED gateway is fully dependent on a choice of control parameters, it has not been fully investigated how to configure its control parameters. In this paper, we analyze the steady state behavior of the RED gateway by explicitly modeling the congestion control mechanism of TCP. We first derive the equilibrium values of the TCP window size and the buffer occupancy of the RED gateway. Also derived are the stability condition and the transient performance index of the network using a control theoretic approach. Numerical examples as well as simulation results are presented to clearly show relations between control parameters and the steady state behavior.

  • Call Admission Control Using a Constraint on Total Composite Received Power in DS-CDMA Systems with Multi-Class Traffic

    Min Kyu PARK  Seong Keun OH  

     
    LETTER-Wireless Communication Technology

      Vol:
    E85-B No:1
      Page(s):
    336-339

    We propose a call admission control (CAC) scheme for the reverse link of direct sequence-code division multiple access (DS-CDMA) systems with multi-class traffic, in which the admissibility of the set of requested channels is decided by checking the outage probability of the total composite power at a cell-site receiver. The reverse link capacities under various traffic conditions are evaluated. From numerical results, we see that the proposed scheme can utilize a given radio resource more effectively as compared with the existing scheme using constraints on the individual power levels.

  • Polarimetric Correlation Coefficient Applied to Tree Classification

    Makoto MURASE  Yoshio YAMAGUCHI  Hiroyoshi YAMADA  

     
    PAPER

      Vol:
    E84-C No:12
      Page(s):
    1835-1840

    Tree canopies contain various scattering elements such as leaves, branches and trunks, which contribute to complex backscattering, depending on frequency and polarization. In this paper, we propose to use the polarimetric correlation coefficient for classifying trees, forests, and vegetations. The polarimetric correlation coefficient can be derived by the elements of Sinclair scattering matrix. Since the scattering matrix can be defined in any polarization basis, we examined the coefficient in the linear HV, circular LR, and optimum polarization bases. First, the change of correlation coefficient inside trees along the range direction is examined using small trees in a laboratory. The wider the range, the better the index. The coefficient defined in the LR polarization basis showed the largest change within tree canopy, which also contribute to retrieve scattering mechanism. Second, this index for discrimination is applied to polarimetric SAR data sets (San Francisco and Briatia area) acquired by AIRSAR and SIR-C/X-SAR. It is shown that polarimetric correlation coefficient in the LR basis best serves to distinguish tree types.

  • Polarimetric SAR Image Classification Using Support Vector Machines

    Seisuke FUKUDA  Haruto HIROSAWA  

     
    PAPER

      Vol:
    E84-C No:12
      Page(s):
    1939-1945

    Support vector machines (SVMs), newly introduced in the 1990s, are promising approach to pattern recognition. They are able to handle linearly nonseparable problems without difficulty, by combining the maximal margin strategy with the kernel method. This paper addresses a novel SVM-based classification scheme of land cover from polarimetric synthetic aperture radar (SAR) data. Polarimetric observations can reveal existing different scattering mechanisms. As the input into SVMs, the polarimetric feature vectors, composed of intensity of each channel, sometimes complex correlation coefficients and textural information, are prepared. Classification experiments with real polarimetric SAR images are satisfactory. Some important properties of SVMs, for example the relation between the number of support vectors and classification accuracy, are also investigated.

  • Balanced Foil Decomposition of Complete Graphs

    Kazuhiko USHIO  Hideaki FUJIMOTO  

     
    PAPER-Graphs and Networks

      Vol:
    E84-A No:12
      Page(s):
    3132-3137

    Let t and n be positive integers. We show that the necessary and sufficient condition for the existence of a balanced t-foil decomposition of the complete graph Kn is n 1 (mod 6t). Decomposition algorithms are also given.

  • Synthesising Application-Specific Heterogeneous Multiprocessors Using Differential Evolution

    Allan RAE  Sri PARAMESWARAN  

     
    PAPER-VLSI Design Technology and CAD

      Vol:
    E84-A No:12
      Page(s):
    3125-3131

    This paper presents an application-specific, heterogeneous multiprocessor synthesis system, named HeMPS, that combines a form of Evolutionary Computation known as Differential Evolution with a scheduling heuristic to search the design space efficiently. We demonstrate the effectiveness of our technique by comparing it to similar existing systems. The proposed strategy is shown to be faster than recent systems on large problems while providing equivalent or improved final solutions.

  • Packaging Technology Trends and Challenges for System-in-Package

    Akihiro DOHYA  

     
    INVITED PAPER

      Vol:
    E84-C No:12
      Page(s):
    1756-1762

    The packaging hierarchy is not fixed structure. It can be changed depending on the packaging technology itself, and the number of hierarchy levels tends to decrease. In LSI-package technology including package-to-board interconnections, there were two evolutionary changes. The first evolution was from PTH to SMT, and the second evolution was from "Peripheral connections" to "Area-array connections. " These evolutions have been caused by ICs integration and application products requirements. Now, the third evolution appears to be in progress, which is from SCP to MCP or SIP. Although SoC has many remarkable features, it has been not applied for many systems contrary to expectations, and its limitations or issues have become clear. SIP is the answer for above SoC's issues. MCP can be considered to be primitive SIP. The purpose of MCP is making up the technology gap between SMT and SoC to address the issues. The targets of SIP are mainly the next two items. (1) Overcoming the interconnection crisis of SoC. (2) Opening new application fields in electronics. In order to achieve those targets, several consortiums in the world are doing research and developing core technologies.

  • Self-Alignment Process Using Liquid Resin for Assembly of Electronic or Optoelectronic Devices

    Kozo FUJIMOTO  Jong-Min KIM  Shuji NAKATA  

     
    PAPER-Optoelectronics

      Vol:
    E84-C No:12
      Page(s):
    1967-1974

    We have developed a novel self-alignment process using the surface tension of the liquid resin for assembly of electronic or optoelectronic devices. Though the liquid resins have a characteristics as low as one tenth of the surface tension of solder in general, restoring forces for self-alignment capability can be produced by making it constrained on the 3-dimensional pads on chip and substrate. In this paper, its principle and characteristics are described and the relationship between process parameters and joint geometry were examined. And the possibility of self-alignment process was verified by analytic numerical method and scaled-up experiment. A self-alignment accuracy was examined experimentally and show that it became less than 0.4 µm. It can provide a useful information on various parameters involved in joint geometry and optimal design guideline to generate the proper profiles.

11961-11980hit(16314hit)