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[Keyword] PAR(2741hit)

1261-1280hit(2741hit)

  • Does Secure Password-Based Authenticated Key Exchange against Leakage of Internal States Exist?

    Kazuki YONEYAMA  

     
    PAPER-Secure Protocol

      Vol:
    E92-A No:1
      Page(s):
    113-121

    In this paper, we raise a question about existence of secure password-based authenticated key exchange against leakage of internal states (i.e., the passwords and session-specific private information). Toward this question, first, we classify six models of adversary's capabilities about leakage. Next, as a result of considerations for 2-party PAKE, we find two negative answers, but also find a positive answer. More specifically, we show that there exists no scheme which is secure in strong leakage models, but we also show that there exists a scheme which is secure in weak leakage models. Also, we consider the case of 3-party setting which is a special setting of password-based authenticated key exchange, and we find similar impossibilities as 2-party setting.

  • Analysis of Post-Wall Waveguide Based on H-Plane Planar Circuit Approach

    Mitsuyoshi KISHIHARA  Isao OHTA  Kensuke OKUBO  Jiro YAMAKITA  

     
    PAPER

      Vol:
    E92-C No:1
      Page(s):
    63-71

    In this paper, we suggest a method of analyzing the post-wall waveguide (PWW) or the substrate integrated waveguide (SIW) by applying the analytical technique of the H-plane waveguide discontinuities based on the planar circuit approach. The analytical procedure consists of the derivation of the mode impedance matrices for regular-shaped circuits and the short-circuiting operation on fictitious ports arranged at the peripheries of the metallic posts. First, a straight section of the PWW is treated as an example and the analytical method for the calculation of the S-parameters is described in detail. Then the attenuation and phase constants of the PWW are computed with the aid of the Thru-Reflect Line (TRL) calibration technique. Next, the analytical method is applied to the design of two types of right-angled corners. The analysis and the design results are verified using an em-simulator (HFSS).

  • Multiparty Computation from El Gamal/Paillier Conversion

    Koji CHIDA  Hiroaki KIKUCHI  Keiichi HIROTA  Gembu MOROHASHI  

     
    PAPER-Secure Protocol

      Vol:
    E92-A No:1
      Page(s):
    137-146

    We propose a protocol for converting the encryption function of a ciphertext into another encryption function while keeping the corresponding message secret. The proposed protocol allows conversions of the El Gamal and Paillier cryptosystems and has the potential to design an efficient multiparty protocol intended for circuits consisting of arithmetic and logical operations. We clarify the condition of circuits such that the multiparty protocol based on the proposed protocol provides better performance than previous approaches. In addition, we introduce some privacy-preserving statistical computations as an effective application of the proposed protocol.

  • The Necessary and Sufficient Condition of a Class of Quasi-Cyclic LDPC Codes without Girth Four

    Ying ZHAO  Yang XIAO  

     
    LETTER-Fundamental Theories for Communications

      Vol:
    E92-B No:1
      Page(s):
    306-309

    This letter presents a necessary and sufficient condition for a class of quasi-cyclic low-density parity-check (QC LDPC) codes without girth four. Girth-four property of a class of QC LDPC codes is investigated. Good QC LDPC codes without girth four can be constructed by selecting proper shifting factors according to the proposed theorems. Examples are provided to verify the theorems. The simulation results show that the QC LDPC codes without girth four achieve a better BER performance compared with that of randomly constructed LDPC codes.

  • Serial-Parallel Content Addressable Memory with a Conditional Driver (SPCwCD)

    Mingu KANG  Seong-Ook JUNG  

     
    LETTER-Circuit Theory

      Vol:
    E92-A No:1
      Page(s):
    318-321

    In this paper, a novel content addressable memory (CAM) structure is proposed to improve the performance of a static divided word matching (SDWM) CAM. In the SDWM CAM, a small pmos has to be used to keep a noise margin, but it degrades performance significantly. To resolve this problem, a conditional driver is introduced in the proposed serial-parallel CAM. Performance is improved by 28.0% without additional power consumption at a cost of about 5.6% increased area when the total bit number is 32 with four series bits and 30% of VDD is allowed as noise.

  • A Design Method for Separable-Denominator 2D IIR Filters with a Necessary and Sufficient Stability Check

    Toma MIYATA  Naoyuki AIKAWA  Yasunori SUGITA  Toshinori YOSHIKAWA  

     
    LETTER-Digital Signal Processing

      Vol:
    E92-A No:1
      Page(s):
    307-310

    In this paper, we propose designing method for separable-denominator two-dimensional Infinite Impulse Response (IIR) filters (separable 2D IIR filters) by Successive Projection (SP) methods using the stability criteria based on the system matrix. It is generally known that separable 2D IIR filters are stable if and only if each of the denominators is stable. Therefore, the stability criteria of 1D IIR filters can be used for separable 2D IIR filters. The stability criteria based on the system matrix are a necessary and sufficient condition to guarantee stability in 1D IIR filters. Therefore, separable 2D IIR filters obtained by the proposed design method have a smaller error ripple than those obtained by the conventional design method using the stability criterion of Rouche's theorem.

  • Cluster System Capacity Improvement by Transferring Load in Virtual Node Distance Order

    Shigero SASAKI  Atsuhiro TANAKA  

     
    PAPER-Computer Systems

      Vol:
    E92-D No:1
      Page(s):
    1-9

    Cluster systems are prevalent infrastructures for offering e-services because of their cost-effectiveness. The objective of our research is to enhance their cost-effectiveness by reducing the minimum number of nodes to meet a given target performance. To achieve the objective, we propose a load balancing algorithm, the Nearest Underloaded algorithm (N algorithm). The N algorithm aims at quick solution of load imbalance caused by request departures while also preventing herd effect. The performance index in our evaluation is the xth percentile capacity which we define based on throughputs and the xth percentile response times. We measured the capacity of 8- to 16-node cluster systems under the N algorithm and existing Least-Loaded (LL) algorithms, which dispatch or transfer requests to the least-loaded node. We found that the N algorithm could achieve larger capacity or could achieve the target capacity with fewer nodes than LL algorithms could.

  • A Parallel Method to Extract Critical Areas of Net Pairs for Diagnosing Bridge Faults

    Keiichi SUEMITSU  Toshiaki ITO  Toshiki KANAMOTO  Masayuki TERAI  Satoshi KOTANI  Shigeo SAWADA  

     
    PAPER-Logic Synthesis, Test and Verification

      Vol:
    E91-A No:12
      Page(s):
    3524-3530

    This paper proposes a new parallel method of producing the adjacent net pair list from the LSI layouts, which is run on workstations connected with the network. The pair list contains pairs of adjacent nets and the probability of a bridging fault between them, and is used in fault diagnosis of LSIs. The proposed method partitions into regions each mask layer of the LSI layout, produces a pair list corresponding to each region in parallel and merges them into the entire pair list. It yields the accurate results, because it considers the faults between two wires containing different adjacent regions. The experimental results show that the proposed method has greatly reduced the processing time from more than 60 hrs. to 3 hrs. in case of 42M-gate LSIs.

  • Efficient Encoding Architecture for IEEE 802.16e LDPC Codes

    Jeong Ki KIM  Hyunseuk YOO  Moon Ho LEE  

     
    LETTER-Embedded, Real-Time and Reconfigurable Systems

      Vol:
    E91-A No:12
      Page(s):
    3607-3611

    The weakness of implementation for LDPC encoder is that conventional binary Matrix Vector Multiplier has many clock cycles which lead to limited throughput. In this letter in order to construct efficient architecture, we target on IEEE 802.16e LDPC encoders. Over the standard H matrices with Circulant Permutation Matrices, we propose semi-parallel architecture by using cyclic right shift registers and exclusive-OR instead of complex Matrix Vector Multipliers. Proposed efficient encoder for IEEE 802.16e LDPC satisfies compact size and high throughput.

  • Performance Evaluation of Grid Computing with Parallel Routes Transmission

    Hiroyuki MIYAGI  Yusuke OKAZAKI  Ryota USUI  Yutaka ARAKAWA  Satoru OKAMOTO  Naoaki YAMANAKA  

     
    LETTER

      Vol:
    E91-B No:12
      Page(s):
    3882-3885

    In a grid computing environment, the network characteristics such as bandwidth and latency affect the task performance. The demands for bandwidth of wide-area networks become large and it reaches more than 100 Gbps. In this article, we focus on parallel routes transmission, such as link aggregation, to realize large bandwidth network. The performance of grid computing with parallel routes transmission is evaluated on the emulated wide-area network.

  • Highly Efficient Comparator Design Automation for TIQ Flash A/D Converter

    Insoo KIM  Jincheol YOO  JongSoo KIM  Kyusun CHOI  

     
    PAPER-Physical Level Design

      Vol:
    E91-A No:12
      Page(s):
    3415-3422

    Threshold Inverter Quantization (TIQ) technique has been gaining its importance in high speed flash A/D converters due to its fast data conversion speed. It eliminates the need of resistor ladders for reference voltages generation which requires substantial power consumption. The key to TIQ comparators design is to generate 2n - 1 different sized TIQ comparators for an n-bit A/D converter. This paper presents a highly efficient TIQ comparator design methodology based on an analytical model as well as SPICE simulation experimental model. One can find any sets of TIQ comparators efficiently using the proposed method. A 6-bit TIQ A/D converter has been designed in a 0.18 µm standard CMOS technology using the proposed method, and compared to the previous measured results in order to verify the proposed methodology.

  • DAC: A Device-Aware Cache Management Algorithm for Heterogeneous Mobile Storage Systems

    Young-Jin KIM  Jihong KIM  

     
    PAPER-System Programs

      Vol:
    E91-D No:12
      Page(s):
    2818-2833

    In recent years, heterogeneous devices have been employed frequently in mobile storage systems because a combination of such devices can supply a synergistically useful storage solution by taking advantage of each device. One important design constraint in heterogeneous storage systems is to mitigate I/O performance degradation stemming from the difference between access times of different devices. To this end, there has not been much work to devise proper buffer cache management algorithms. This paper presents a novel buffer cache management algorithm which considers both I/O cost per device and workload patterns in mobile computing systems with a heterogeneous storage pair of a hard disk and a NAND flash memory. In order to minimize the total I/O cost under varying workload patterns, the proposed algorithm employs a dynamic cache partitioning technique over different devices and manages each partition according to request patterns and I/O types along with the temporal locality. Trace-based simulations show that the proposed algorithm reduces the total I/O cost and flash write count significantly over the existing buffer cache algorithms on typical mobile traces.

  • Throughput Efficiency of Go-Back-N ARQ Protocol on Parallel Multi-Channel with Burst Errors

    Kenichi NAGAOKA  Chun-Xiang CHEN  Masaharu KOMATSU  

     
    LETTER-Fundamental Theories for Communications

      Vol:
    E91-B No:12
      Page(s):
    3994-3997

    In this paper, we investigate the throughput efficiency of the Go-Back-N ARQ protocol on parallel multiple channels with burst errors. We assume that packet errors occur according to a two-state Markov chain on each channel. The effect of the decay factor of the Markov chain on throughput efficiency is evaluated based on the results of numerical analysis.

  • GridFTP-APT: Automatic Parallelism Tuning Mechanism for GridFTP in Long-Fat Networks

    Takeshi ITO  Hiroyuki OHSAKI  Makoto IMASE  

     
    PAPER-Network

      Vol:
    E91-B No:12
      Page(s):
    3925-3936

    In this paper, we propose an extension to GridFTP that optimizes its performance by dynamically adjusting the number of parallel TCP connections. GridFTP has been used as a data transfer protocol to effectively transfer a large volume of data in Grid computing. GridFTP supports a feature called parallel data transfer that improves throughput by establishing multiple TCP connections in parallel. However, for achieving high GridFTP throughput, the number of TCP connections should be optimized based on the network status. In this paper, we propose an automatic parallelism tuning mechanism called GridFTP-APT (GridFTP with Automatic Parallelism Tuning) that adjusts the number of parallel TCP connections according to information available to the Grid middleware. Through simulations, we demonstrate that GridFTP-APT significantly improves the performance of GridFTP in various network environments.

  • Electrochromic Thin Film of Water-Dispersible Prussian-Blue Nanoparticles

    Ayako OMURA  Hirofumi SHIOZAKI  Shigeo HARA  Tohru KAWAMOTO  Akihito GOTOH  Masahito KURIHARA  Masaomi SAKAMOTO  Hisashi TANAKA  

     
    LETTER-Materials & Devices

      Vol:
    E91-C No:12
      Page(s):
    1887-1888

    The insoluble Prussian-blue (PB) pigment becomes possible to disperse in aqueous solution by covering their surfaces with ferrocyanide anions. The thin film fabricated with these water-dispersible PB nanoparticles shows evident electrochromic color changes between +0.8 V to -0.4 V on an ITO substrate. The mass change of the thin film during an electrochemical reaction is measured by means of electrochemical quartz crystal microbalance (EQCM). According to the EQCM analysis, the filling rate of water-dispersible PB nanoparticles in the film is 37.7% as compared with an assumed perfect crystal PB film.

  • 3D Triangular Mesh Parameterization with Semantic Features Based on Competitive Learning Methods

    Shun MATSUI  Kota AOKI  Hiroshi NAGAHASHI  

     
    PAPER-Computer Graphics

      Vol:
    E91-D No:11
      Page(s):
    2718-2726

    In 3D computer graphics, mesh parameterization is a key technique for digital geometry processings such as morphing, shape blending, texture mapping, re-meshing and so on. Most of the previous approaches made use of an identical primitive domain to parameterize a mesh model. In recent works of mesh parameterization, more flexible and attractive methods that can create direct mappings between two meshes have been reported. These mappings are called "cross-parameterization" and typically preserve semantic feature correspondences between target meshes. This paper proposes a novel approach for parameterizing a mesh into another one directly. The main idea of our method is to combine a competitive learning and a least-square mesh techniques. It is enough to give some semantic feature correspondences between target meshes, even if they are in different shapes or in different poses.

  • Simultaneous Tunable Wavelength Conversion and Power Amplification Using a Pump-Modulated Wide-Band Fiber Optical Parametric Amplifier

    Guo-Wei LU  Kazi Sarwar ABEDIN  Tetsuya MIYAZAKI  

     
    LETTER-Fiber-Optic Transmission for Communications

      Vol:
    E91-B No:11
      Page(s):
    3712-3714

    We propose and experimentally demonstrate an all-optical broadband wavelength conversion scheme with simultaneous power amplification based on a pump-modulated fiber optic parametric amplifier (FOPA). All-optical tunable wavelength conversion from one to two wavelengths was achieved with ≥13 dB extinction ratio and <2.7-dB power penalty, accompanied by a high (≥37 dB) and flat ( 3 dB variation) FOPA gain spectrum over 47 nm.

  • Configuration Sharing to Reduce Reconfiguration Overhead Using Static Partial Reconfiguration

    Sungjoon JUNG  Tag Gon KIM  

     
    PAPER-Computer Systems

      Vol:
    E91-D No:11
      Page(s):
    2675-2684

    Reconfigurable architectures are one of the most promising solutions satisfying both performance and flexibility. However, reconfiguration overhead in those architectures makes them inappropriate for repetitive reconfigurations. In this paper, we introduce a configuration sharing technique to reduce reconfiguration overhead between similar applications using static partial reconfiguration. Compared to the traditional resource sharing that configures multiple temporal partitions simultaneously and employs a time-multiplexing technique, the proposed configuration sharing reconfigures a device incrementally as an application changes and requires a backend adaptation to reuse configurations between applications. Adopting a data-flow intermediate representation, our compiler framework extends a min-cut placer and a negotiation-based router to deal with the configuration sharing. The results report that the framework could reduce 20% of configuration time at the expense of 1.9% of computation time on average.

  • Fast Tracking of a Real Sinusoid with Multiple Forgetting Factors

    Md. Tawfiq AMIN  Kenneth Wing-Kin LUI  Hing-Cheung SO  

     
    LETTER-Digital Signal Processing

      Vol:
    E91-A No:11
      Page(s):
    3374-3379

    In this paper, a recursive Gauss-Newton (RGN) algorithm is first developed for adaptive tracking of the amplitude, frequency and phase of a real sinusoid signal in additive white noise. The derived algorithm is then simplified for computational complexity reduction as well as improved with the use of multiple forgetting factor (MFF) technique to provide a flexible way of keeping track of the parameters with different rates. The effectiveness of the simplified MFF-RGN scheme in sinusoidal parameter tracking is demonstrated via computer simulations.

  • Characteristcs of Ga-Doped ZnO Films Prepared by RF Magnetron Sputtering in Ar+H2 Ambience

    Koichi MUTO  Satoru ODASHIMA  Norimitsu NASU  Osamu MICHIKAMI  

     
    PAPER

      Vol:
    E91-C No:10
      Page(s):
    1649-1652

    Ga-doped ZnO thin films were prepared by RF magnetron sputtering. The effects of adding H2 to pure Ar sputtering gas were investigated. In the case of pure Ar at 2 Pa, the resistivity is 7.4510-3 Ωcm, whereas for Ar+1%H2 at 0.3 Pa, it markedly decreases to 2.5210-4 Ωcm. In this case, the carrier density and Hall mobility are 1.121021 cm-3 and 23.4 cm2/Vs, respectively. This conductive film also exhibits a transmittance of 90% within the visible-wavelength range. The addition of H2 and the decrease in the pressure results in the fabrication of a significantly more transparent and conductive film.

1261-1280hit(2741hit)