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[Keyword] CTI(8214hit)

4841-4860hit(8214hit)

  • A Novel Ranging Method using Energy Window Bank in Non-coherent UWB Systems

    Woon-Yong PARK  Won-Cheol LEE  Sungsoo CHOI  Kwan-Ho KIM  

     
    LETTER

      Vol:
    E89-A No:6
      Page(s):
    1766-1770

    This paper proposes a novel UWB ranging scheme employing 1-bit ADCs and analog window bank for energy collection. For an appropriate 1-bit ADC process DC offset is exploited and removed via performing analog low pass filter. To improve ranging accuracy in presence of ambiguity, dual overlapped window banks designated as primary and auxiliary windows are utilized. Corresponding to the proposed ranging scheme, its performance is verified by conducting simulations in two types of channel conditions. The simulation results show that the proposed ranging scheme performs well even in condensed multipath environment and low SNR situation.

  • Performance Evaluation and Experiment of a Configuration Algorithm for Three-Stage Multi-Granularity Optical Cross-Connects

    Yongmin QI  Wei GUO  Yi ZHANG  Siye ZUO  Yaohui JIN  Weisheng HU  

     
    PAPER-Switching for Communications

      Vol:
    E89-B No:6
      Page(s):
    1747-1754

    We study the configuration issue of three-stage multi-granularity optical cross-connects (MG-OXC) for the dynamic traffic model in all-optical networks. From the single node point of view, we propose a configuration algorithm to configure different granularity cross-connects for arrival sub-requests with different traffic types and bandwidths. The performance of the configuration algorithm is evaluated by simulation and, furthermore, is validated by experiment based on our flexible Multi-functional Optical Switching Testbed (MOST).

  • MIMO Interconnects Order Reductions by Using the Multiple Point Adaptive-Order Rational Global Arnoldi Algorithm

    Chia-Chi CHU  Ming-Hong LAI  Wu-Shiung FENG  

     
    PAPER

      Vol:
    E89-C No:6
      Page(s):
    792-802

    We extend the adaptive-order rational Arnoldi algorithm for multiple-inputs and multiple-outputs (MIMO) interconnect model order reductions. Instead of using the standard Arnoldi algorithm for the SISO adaptive-order reduction algorithm (AORA), we study the adaptive-order rational global Arnoldi (AORGA) algorithm for MIMO model reductions. In this new algorithm, the input matrix is treated as a vector form. A new matrix Krylov subspace, generated by the global Arnoldi algorithm, will be developed by a Frobenius-orthonormal basis. By employing congruence transformation with the matrix Krylov subspace, the one-sided projection method can be used to construct a reduced-order system. It will be shown that the system moment matching can be preserved. In addition, we also show that the transfer matrix residual error of the reduced system can be derived analytically. This error information will provide a guideline for the order selection scheme. The algorithm can also be applied to the classical multiple point MIMO Pade approximation by the rational Arnoldi algorithm for multiple expansion points. Experimental results demonstrate the feasibility and the effectiveness of the proposed method.

  • Realtime Hand Posture Estimation with Self-Organizing Map for Stable Robot Control

    Kiyoshi HOSHINO  Takanobu TANIMOTO  

     
    PAPER-Robot and Interface

      Vol:
    E89-D No:6
      Page(s):
    1813-1819

    The hand posture estimation system by searching a similar image from a vast database, such as our previous research, may cause the increase of processing time, and prevent realtime controlling of a robot. In this study, the authors proposed a new estimation method of human hand posture by rearranging a large-scale database with the Self-Organizing Map including self-reproduction and self-annihilation, which enables two-step searches of similar image with short period of processing time, within small errors, and without deviation of search time. The experimental results showed that our system exhibited good performance with high accuracy within processing time above 50 fps for each image input with a 2.8 GHz CPU PC.

  • An Investigation on the Plant Modeling Filter's Parameters for Active Noise Control System

    Jinjun WANG  Kean CHEN  Guoyue CHEN  Kenji MUTO  

     
    LETTER-Noise and Vibration

      Vol:
    E89-A No:6
      Page(s):
    1847-1851

    Usually an FIR filter is used to model the physical paths in an active noise control system. However, the order of the filter to be modeled is a key factor for determining the computational load for the adaptive algorithms associated with active noise control (ANC), particularly for multi-channel algorithms. In this letter, the relationships among the filter's order, the plant modeling error and the location of poles for the transfer functions of the physical paths in an ANC system are theoretically examined and numerical examples are given to verify the theoretical results.

  • Improvement of Gray Scale CCT for Mobile Phone LCD

    In-Ho SONG  Bong-Soo KIM  Eun-Su KIM  Sung-Hak LEE  Soo-Wook JANG  Kyu-Ik SOHNG  

     
    LETTER

      Vol:
    E89-A No:6
      Page(s):
    1724-1726

    Color reproductions in most LCD are quite different from those of standard CRT (cathode ray tube) monitor display because of the nonlinear characteristic in subtractive color reproduction. Moreover, gray scale CCT (correlated color temperature) reproductions in a typical mobile phone LCD depend on the input RGB levels. A simple LUT (Look-up table) method for constant gray scale CCT and gamma characteristic of mobile phone LCD is presented in this paper. We investigate the mobile phone LCD's characteristic of compensation of CCT with using the LUT. LCD's CCT is maintaining about 7500 K, which is the target CCT of mobile phone LCD in this paper. Also LCD's gamma is similar to target gamma.

  • Novel First-Order Non-inverting and Inverting Output of All-Pass Filter at the Same Configuration Using ICCII

    Hua-Pin CHEN  Ming-Tzau LIN  Wan-Shing YANG  

     
    LETTER-Electronic Circuits

      Vol:
    E89-C No:6
      Page(s):
    865-867

    A novel first order voltage-mode non-inverting and inverting output of all-pass filter using an inverting type current conveyor (ICCII) is given. It is a first announced about a first-order voltage-mode non-inverting and inverting output of all-pass filter at the same configuration in the literature. The proposed circuit is verified using HSPICE simulation with attractive results.

  • Noise-Predictive Equalization for Unique-Word Based Single-Carrier Systems

    Xiao-lin CHE  Chen HE  Ling-ge JIANG  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E89-B No:6
      Page(s):
    1903-1906

    In this letter two noise-predictive equalization schemes, which are based on zero-forcing (ZF) and minimum mean square error (MMSE) criteria, are presented for unique-word (UW) based single-carrier systems. The correlation properties of the noises in the outputs of the frequency domain equalizer are exploited to predict and cancel the noise contained in the estimation of data. Theoretical analyses show that both of the proposed techniques perform better than the conventional frequency domain equalizers. Simulation results have confirmed the significant performance improvement they could achieve.

  • A Method for English-Korean Target Word Selection Using Multiple Knowledge Sources

    Ki-Young LEE  Sang-Kyu PARK  Han-Woo KIM  

     
    PAPER

      Vol:
    E89-A No:6
      Page(s):
    1622-1629

    Target word selection is one of the most important and difficult tasks in English-Korean Machine Translation. It effects on the overall translation accuracy of machine translation systems. In this paper, we present a new approach to Korean target word selection for an English noun with translation ambiguities using multiple knowledge such as verb frame patterns, sense vectors based on collocations, statistical Korean local context information and co-occurring POS information. Verb frame patterns constructed with dictionary and corpus play an important role in resolving the sparseness problem of collocation data. Sense vectors are a set of collocation data when an English word having target selection ambiguities is to be translated to specific Korean target word. Statistical Korean Local Context Information is an N-gram information generated using Korean corpus. The co-occurring POS information is a statistically significant POS clue which appears with ambiguous word. To evaluate our approach, we applied the method to Tellus-EK system, English-Korean automatic translation system currently developed at ETRI [1],[2]. The experiment showed promising results for diverse sentences from web documents.

  • Emulation Circuit for Superconducting Quantum Interference Device (SQUID) Sensor in Magnetocardiography System

    Chang-Beom AHN  Dong-Hoon LEE  Hochong PARK  Seoung-Jun OH  

     
    LETTER

      Vol:
    E89-A No:6
      Page(s):
    1688-1689

    The superconducting quantum interference device (SQUID) is a transducer that converts magnetic flux into voltage. Its range of linear conversion, however, is very restricted. To overcome its narrow dynamic range, a flux-locked loop (FLL) is used to feedback the output field to cancel the input field. This prevents the operating point of the SQUID from moving far away from the null point. In this paper, an emulator for the SQUID sensor and the feedback coil has been proposed. Magnetic coupling between the original field and the generated field by the feedback coil was emulated by electronic circuits. By using the emulator, FLL circuits can be analyzed and optimized without use of SQUID sensors. This is a useful feature, especially in the early stage of development of the MCG system when a magnetically shielded room or real SQUID sensors may not yet be available. The emulator may also be used as a test signal generator for multi-channel gain calibration and for system maintenance.

  • Numerical Investigation of Octagonal Photonic Crystal Fibers with Strong Confinement Field

    Kenta KANESHIMA  Yoshinori NAMIHIRA  Nianyu ZOU  Hiroki HIGA  Yasunori NAGATA  

     
    PAPER-Optoelectronics

      Vol:
    E89-C No:6
      Page(s):
    830-837

    In this paper, the confinement loss of octagonal photonic crystal fibers (PCFs) with an isosceles triangle lattice of air-holes are numerically investigated. Taking into account the confinement loss, the mode field diameter (MFD), the effective area (Aeff) and the chromatic dispersion of octagonal PCFs are calculated, compared to conventional hexagonal PCFs. It is found from confinement loss and MFD results that the octagonal PCFs can confine the field strongly than the hexagonal PCFs due to the different air filling fraction. Moreover, it is shown that the octagonal PCFs are obtained not only positive but also negative larger dispersion values and smaller Aeff values compared to the hexagonal PCFs.

  • A -90 dBc@10 kHz Phase Noise Fractional-N Frequency Synthesizer with Accurate Loop Bandwidth Control Circuit

    Shiro DOSHO  Takashi MORIE  Koji OKAMOTO  Yuuji YAMADA  Kazuaki SOGAWA  

     
    PAPER

      Vol:
    E89-C No:6
      Page(s):
    739-745

    This paper describes a -90 dBc@10 kHz phase noise fractional-N frequency synthesizer of 110 M-180 MHz output with accurate loop bandwidth control. Stable phase noise characteristics are achieved by controlling the bandwidth correctly, even if the PLL uses a noisy but small ring oscillator. Digital controller adjusts voltage controlled oscillator (VCO) gain and time constant of the loop filter. Analog controller compensates temperature variance. Test chip fabricated on 0.13 µm CMOS process shows stable and 6.8 dB improvement of the phase noise performance is achieved against process and environmental variations.

  • I-Poll: Improved Polling Scheme for Augmenting Voice Support in IEEE 802.11 PCF

    Jun ZHENG  Emma REGENTOVA  

     
    LETTER-Terrestrial Radio Communications

      Vol:
    E89-B No:6
      Page(s):
    1964-1967

    In this paper, we present a polling scheme which allows for augmenting the support of voice communications in point co-ordination function (PCF) of IEEE 802.11 wireless networks. In this scheme, the Access Point (AP) of the Basic Service Set (BSS) maintains two polling lists, i.e. the talking list and the silence list. Based on the talking status of the stations identified via silence detection, two lists are dynamically adjusted by the AP. Temporary removal is applied to the stations in the silence list to further upgrade the performance. The conducted study based on simulation has shown that the proposed scheme can support more voice stations and has a lower packet loss rate than that obtained by four reference polling algorithms.

  • An Interactive Multimedia Instruction System: IMPRESSION for Double Loop Instructional Design Process Model

    Yuki HIGUCHI  Takashi MITSUISHI  Kentaro GO  

     
    PAPER-Service and System

      Vol:
    E89-D No:6
      Page(s):
    1877-1884

    In this paper, we propose an interactive instruction system named IMPRESSION, which allows performance of interactive presentations using multimedia educational materials in class. In recent years, although many practices of educational methodology with information technology and presentation tools using multimedia resources as educational materials have come into common use, instructors can only present such materials in a slide-sheet form through the use of such presentation tools in class. Therefore, instructors can neither do formative evaluations nor can they present suitable materials according to students' reactions in class. Our proposed methodology employs a scenario-based approach in a double loop instructional design process to overcome such problems. Instructors design an instructional plan as a scenario, and subsequently implement and modify the plan through formative evaluation during the class. They then conduct a summative evaluation based on planned and implemented instructions for redesign. To realize our methodology, in this paper we propose and design an instruction system that provides functions to select and present multimedia materials interactively provided on the Internet during the class; we then record these instructions. After implementing it, we confirmed that we can conduct the class flexibly based on our methodology through its practical use in an actual classroom environment.

  • Computer Aided Detection of Breast Masses from Digitized Mammograms

    Han ZHANG  Say-Wei FOO  

     
    PAPER-Biological Engineering

      Vol:
    E89-D No:6
      Page(s):
    1955-1961

    In this paper, an automated computer-aided-detection scheme is proposed to identify and locate the suspicious masses in the abnormal breasts from the full mammograms. Mammograms are examined using a four-stage detection method including pre-processing, identification of local maxima, seeded region-growing, and false positive (FP) reduction. This method has been applied to the entire Mammographic Image Analysis Society (MIAS) database of 322 digitized mammograms containing 59 biopsy-proven masses in 56 images. Results of detection show 95% true positive (TP) fraction at 1.9 FPs per image for the 56 images and 1.3 FPs per image for the entire database.

  • Analysis on Empathy-Inducing Effect Brought by Haiku

    Masami SUZUKI  Yuichi KOBAYASHI  Takahiro NAKAI  Kaori YOSHIDA  

     
    PAPER-Language

      Vol:
    E89-D No:6
      Page(s):
    1860-1867

    In this paper, we discuss the issue of empathy-inducing effect brought by Japanese Haiku, regarded as the world-shortest poetry. Its condensed form of word combination sometimes arouses deep impression and empathy in readers. Its possibilities as communication media would be enhanced in multimedia contexts, when considering educational purpose or cross-cultural interchanges. An experimental result is shown for evaluating multimedia effect on combined presentation of a CG drawing and its associated haiku in English. We confirmed that various aspects of visual impression and empathy were sometimes enhanced with certain haiku text as linguistic stimuli, compared with the condition of viewing a CG drawing only. The reason of raised empathy was analyzed from the various aspects of the content provided by the associated haiku text complementary for the drawing. Moreover, we examined the effects of poetic styles on subjects' empathy, using Japanese prose and conventional haiku style (5-7-5 syllabic rhyme), both of them were translated from the same haiku in English.

  • Visualization Methods for Outdoor See-Through Vision

    Takahiro TSUDA  Haruyoshi YAMAMOTO  Yoshinari KAMEDA  Yuichi OHTA  

     
    PAPER-Vision and Image

      Vol:
    E89-D No:6
      Page(s):
    1781-1789

    Visualizing occluded objects is a useful applications of Mixed Reality (MR), which we call "see-through vision." For this application, it is important to display occluded objects in such a manner that they can be recognized intuitively by the user. Here, we evaluated four visualization methods for see-through vision that can aid the user to recognize occluded objects in outdoor scenes intuitively: "elimination of occluding objects," "ground grid," "overlaying model of occluding object," and "top-down view." As we used a new handheld MR device for outdoor see-through vision, we performed subjective experiments to determine the best combination of methods. The experimental results indicated that a combination of showing the ground grid, overlaying wireframe models of occluding objects, and top-down view to be optimal, while it was not necessary to display occluding objects for outdoor see-through vision with a handheld device, because users can see them with the naked eye.

  • Antenna Selection Using Genetic Algorithm for MIMO Systems

    Qianjing GUO  Suk Chan KIM  Dong Chan PARK  

     
    LETTER

      Vol:
    E89-A No:6
      Page(s):
    1773-1775

    Recent work has shown that the usage of multiple antennas at the transmitter and receiver in a flat fading environment results in a linear increase in channel capacity. But increasing the number of antennas induces the higher hardware costs and computational burden. To overcome those problems, it is effective to select antennas appropriately among all available ones. In this paper, a new antenna selection method is proposed. The transmit antennas are selected so as to maximize the channel capacity using the genetic algorithm (GA) which is the one of the general random search algorithm. The results show that the proposed GA achieves almost the same performance as the optimal selection method with less computational amount.

  • Collusion-Attack Free ID-Based Non-interactive Key Sharing

    Hatsukazu TANAKA  

     
    PAPER-Information Security

      Vol:
    E89-A No:6
      Page(s):
    1820-1824

    A new simply implemented collusion-attack free identity-based non-interactive key sharing scheme (ID-NIKS) has been proposed. A common-key can be shared by executing only once a modular exponentiation which is equivalent to RSA deciphering, and the security depends on the difficulty of factoring and the discrete logarithm problem. Each user's secret information can be generated by solving two simple discrete logarithm problems and synthsizing their solutions by linear combination. The detail comparison with the Maurer-Yacobi's scheme including its modified versions shows that the computational complexity to generate each user's secret information is much smaller and the freedom to select system parameters is much greater than that of the Maurer-Yacobi's scheme. Then our proposed scheme can be implemented very easily and hence it is suitable for practical use.

  • A Practical Method of Numerical Calculation of the Mapping Degree

    Sunao MURASHIGE  

     
    PAPER-Numerical Analysis and Optimization

      Vol:
    E89-A No:6
      Page(s):
    1813-1819

    This paper proposes a simple and efficient method to numerically obtain the mapping degree deg(f, 0, B) of a C1 map f : Rn → Rn at a regular value 0 relative to a bounded open subset B ⊂ Rn. For practical application, this method adopts Aberth's algorithm which does not require computation of derivatives and determinants, and reduces the computational cost with two additional procedures, namely preconditioning using the coordinate transformation and pruning using Krawczyk's method. Numerical examples show that the proposed method gives the mapping degree with 2n+1 operations using interval arithmetic.

4841-4860hit(8214hit)