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[Keyword] Al(20498hit)

8621-8640hit(20498hit)

  • A Study of Inherent Pen Input Modalities for Precision Parameter Manipulations during Trajectory Tasks

    Yizhong XIN  Xiangshi REN  

     
    PAPER-Human-computer Interaction

      Vol:
    E92-D No:12
      Page(s):
    2454-2461

    Adjustment of a certain parameter in the course of performing a trajectory task such as drawing or gesturing is a common manipulation in pen-based interaction. Since pen tip information is confined to x-y coordinate data, such concurrent parameter adjustment is not easily accomplished in devices using only a pen tip. This paper comparatively investigates the performance of inherent pen input modalities (Pressure, Tilt, Azimuth, and Rolling) and Key Pressing with the non-preferred hand used for precision parameter manipulation during pen sliding actions. We elaborate our experimental design framework here and conduct experimentation to evaluate the effect of the five techniques. Results show that Pressure enabled the fastest performance along with the lowest error rate, while Azimuth exhibited the worst performance. Tilt showed slightly faster performance and achieved a lower error rate than Rolling. However, Rolling achieved the most significant learning effect on Selection Time and was favored over Tilt in subjective evaluations. Our experimental results afford a general understanding of the performance of inherent pen input modalities in the course of a trajectory task in HCI (human computer interaction).

  • Hydrogen Plasma Annealing of ZnO Films Deposited by Magnetron Sputtering with Third Electrode

    Kanji YASUI  Yutaka OOSHIMA  Yuichiro KUROKI  Hiroshi NISHIYAMA  Masasuke TAKATA  Tadashi AKAHANE  

     
    PAPER-Nanomaterials and Nanostructures

      Vol:
    E92-C No:12
      Page(s):
    1438-1442

    Al doped zinc oxide (AZO) films were deposited using a radio frequency (rf) magnetron sputtering apparatus with a mesh grid electrode. Improvement of crystalline uniformity was achieved by the use of an appropriate negative grid bias to effectively suppress the bombardment of high-energy charged particles onto the film surface. The uniformity of the film's electronic properties, such as resistivity, carrier concentration and Hall mobility, was also improved using the sputtering method. Hydrogen plasma annealing was investigated to further decrease the resistivity of the ZnO films and the carrier concentration was increased by 1-21020 cm-3 without decrease in the Hall mobility.

  • Macroblock and Motion Feature Analysis to H.264/AVC Fast Inter Mode Decision

    Yiqing HUANG  Qin LIU  Shuijiong WU  Zhewen ZHENG  Takeshi IKENAGA  

     
    PAPER-Coding

      Vol:
    E92-A No:12
      Page(s):
    3361-3368

    One fast inter mode decision algorithm is proposed in this paper. The whole algorithm is divided into two stages. In the pre-stage, by exploiting spatial and temporal information of encoded macrobocks (MBs), a skip mode early detection scheme is proposed. The homogeneity of current MB is also analyzed to filter out small inter modes in this stage. Secondly, during the block matching stage, a motion feature based inter mode decision scheme is introduced by analyzing the motion vector predictor's accuracy, the block overlapping situation and the smoothness of SAD (sum of absolute difference) value. Moreover, the rate distortion cost is checked in an early stage and we set some constraints to speed up the whole decision flow. Experiments show that our algorithm can achieve a speed up factor of up to 53.4% for sequences with different motion type. The overall bit increment and quality degradation is negligible compared with existing works.

  • Performance of Downlink DSTBC-WCDMA in Fast-Varying Time-Dispersive Channels

    Edwin M. UMALI  Joel Joseph S. MARCIANO, Jr.  Yasushi YAMAO  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E92-B No:12
      Page(s):
    3815-3826

    This paper presents the performance of DSTBC when applied on the downlink transmission of WCDMA cellular systems in fast-varying time-dispersive channels. First, three DSTBC-WCDMA receiver architectures are proposed and they are: (1) the DSTBC Rake receiver for combined-code (D-Rake-C), (2) the DSTBC deterministic receiver for combined-code (D-Det-C), and (3) the DSTBC deterministic de-prefix receiver for combined-code (D-Det-DP-C). Detection can be divided into a correlator that combines descrambling and despreading, and a DSTBC decoder. The correlator is designed to perform signal separation of the multipath-multiuser signal via least-square (LS) estimation. To enable the correlator to perform signal separation at every block period, the long combined spreading and scrambling codes are divided into shorter codes. Then, the proposed receivers are theoretically analyzed in time-dispersive channels and multiple-user environment using the moment generating function (MGF) of fading distributions. For analyzing interference tolerance, the standard Gaussian approximation is employed. Finally, simulations are performed. Theoretical performance well matches simulated results. Among the three receivers, the D-Det-DP-C receiver has the best performance in time-dispersive channels with a maximum excess delay of 4 chips and a maximum Doppler frequency of 250 Hz. Results also show minimal performance degradation for fast fading channels with a maximum Doppler frequency of 1200 Hz. The best performance is obtained when the receiver has the information on the maximum excess delay and all users' spreading codes.

  • A Simple Canonical Code for Fullerene Graphs

    Naoki SHIMOTSUMA  Shin-ichi NAKANO  

     
    LETTER-Algorithms and Data Structures

      Vol:
    E92-A No:12
      Page(s):
    3398-3400

    In this paper we give a simple algorithm to compute a canonical code for fullerene graphs. Our algorithm runs in O(n) time, while the best known algorithm runs in O(n2) time. Our algorithm is simple. One can generalize the algorithm to compute a canonical code for the skeleton of a convex polyhedron with n vertices. The algorithm runs in O(n2) time.

  • Activating Humans with Humor -- A Dialogue System That Users Want to Interact with

    Pawel DYBALA  Michal PTASZYNSKI  Rafal RZEPKA  Kenji ARAKI  

     
    PAPER-Spoken Dialogue System

      Vol:
    E92-D No:12
      Page(s):
    2394-2401

    The topic of Human Computer Interaction (HCI) has been gathering more and more scientific attention of late. A very important, but often undervalued area in this field is human engagement. That is, a person's commitment to take part in and continue the interaction. In this paper we describe work on a humor-equipped casual conversational system (chatterbot) and investigate the effect of humor on a user's engagement in the conversation. A group of users was made to converse with two systems: one with and one without humor. The chat logs were then analyzed using an emotive analysis system to check user reactions and attitudes towards each system. Results were projected on Russell 's two-dimensional emotiveness space to evaluate the positivity/negativity and activation/deactivation of these emotions. This analysis indicated emotions elicited by the humor-equipped system were more positively active and less negatively active than by the system without humor. The implications of results and relation between them and user engagement in the conversation are discussed. We also propose a distinction between positive and negative engagement.

  • A Novel Method for Information Gathering by Using Orthogonal Narrowband Signal for Cooperative Sensing in Cognitive Radio

    Mai OHTA  Takeo FUJII  Kazushi MURAOKA  Masayuki ARIYOSHI  

     
    PAPER-Spectrum Sensing

      Vol:
    E92-B No:12
      Page(s):
    3625-3634

    In this paper, we propose a novel method for gathering sensing information by using an orthogonal narrowband signal for cooperative sensing in cognitive radio. It is desirable to improve the spectrum sensing performance by countering the locality effect of a wireless channel; cooperative sensing by using multiple inputs of sensing information from the surrounding sensing nodes has attracted attention. Cooperative sensing requires that sensing information be gathered at the master node for determining the existence of a primary signal. If the used information gathering method leads to redundancies, the total capacity of the secondary networks is not improved. In this paper, we propose a novel method for gathering sensing information that maps the sensing information to the orthogonal narrowband signal to achieve simultaneous sensing information gathering at the master node. In this method, the sensing information is mapped to an orthogonal subcarrier signal of an orthogonal frequency division multiplexing (OFDM) structure to reduce the frequency resource required for sensing information gathering. The orthogonal signals are transmitted simultaneously from multiple sensing nodes. This paper evaluates the performance of the proposed information gathering method and confirms its effectiveness.

  • A Compact On-Frequency Indoor Repeater Antenna with High Isolation for WCDMA Applications

    Youngki LEE  Jeongpyo KIM  Jaehoon CHOI  

     
    LETTER-Antennas and Propagation

      Vol:
    E92-B No:12
      Page(s):
    3964-3967

    In this paper, an indoor repeater antenna with high isolation for WCDMA application is proposed. The designed repeater has very small separation of 20 mm between the donor and server antennas. The antenna has two resonance frequencies to cover the WCDMA band from 1.92 GHz to 2.17 GHz. The fabricated antenna has VSWR below 1.5, gain over 8 dBi, and isolation between server and donor antennas less than -80 dB in the WCDMA band.

  • Improve Throughput of Ad Hoc Networks Using Power Controlled Busy Tone

    Kewang ZHANG  Deyun ZHANG  

     
    PAPER-Network

      Vol:
    E92-B No:12
      Page(s):
    3784-3793

    The hidden terminal problem leads to frequent collisions and decreases the throughput of ad hoc networks dramatically. Low network spatial reuse also results in fewer parallel transmissions, which further leads to reduced network throughput. Eliminating the hidden terminals and improving the spatial reuse are two important approaches to improving network throughput. In this paper, spatial distribution of the hidden terminals is analyzed in consideration of accumulated interference and environmental noise. As the distribution of hidden terminals is affected by many factors such as transmitter-receiver distance, SINR requirement and nodes density, it is inefficient to use fixed busy tone transmission power. To eliminate the hidden terminals and improve network spatial reuse, an enhancement to DBTMA named EDBTMA is proposed. This is achieved by using an adaptive busy tone power control scheme. Receivers adjust the transmission power of busy tone according to received signal power and accumulated interference adaptively so that all hidden terminals (and only hidden terminals) are covered by the busy tone. Simulation results show that EDBTMA protocol can solve the hidden terminal problem and improve network spatial reuse better than DBTMA and achieves 65% additional network throughput compared to DBTMA.

  • Peak Temperature Reduction by Physical Information Driven Behavioral Synthesis with Resource Usage Allocation

    Junbo YU  Qiang ZHOU  Gang QU  Jinian BIAN  

     
    PAPER-High-Level Synthesis and System-Level Design

      Vol:
    E92-A No:12
      Page(s):
    3151-3159

    High temperature adversely impacts on circuit's reliability, performance, and leakage power. During behavioral synthesis, both resource usage allocation and resource binding influence thermal profile. Current thermal-aware behavioral syntheses do not utilize location information of resources from floorplan and in addition only focus on binding, ignoring allocation. This paper proposes thermal-aware behavioral synthesis with resource usage allocation. Based on a hybrid metric of physical location information and temperature, we rebind operations and reallocate the number of resources under area constraint. Our approach effectively controls peak temperature and creates even power densities among resources of different types and within resources of the same type. Experimental results show an average of 8.6 drop in peak temperature and 5.3% saving of total power consumption with little latency overhead.

  • Randomized Online File Allocation on Uniform Cactus Graphs

    Yasuyuki KAWAMURA  Akira MATSUBAYASHI  

     
    PAPER-Algorithm Theory

      Vol:
    E92-D No:12
      Page(s):
    2416-2421

    We study the online file allocation problem on ring networks. In this paper, we present a 7-competitive randomized algorithm against an adaptive online adversary on uniform cactus graphs. The algorithm is deterministic if the file size is 1. Moreover, we obtain lower bounds of 4.25 and 3.833 for a deterministic algorithm and a randomized algorithm against an adaptive online adversary, respectively, on ring networks.

  • Moments Added Statistical Shape Model for Boundary Extraction

    Haechul CHOI  Ho Chul SHIN  Si-Woong LEE  Yun-Ho KO  

     
    LETTER-Pattern Recognition

      Vol:
    E92-D No:12
      Page(s):
    2524-2526

    In this paper, we propose a method for extracting an object boundary from a low-quality image such as an infrared one. To take full advantage of a training set, the overall shape is modeled by incorporating statistical characteristics of moments into the point distribution model (PDM). Furthermore, a differential equation for the moment of overall shape is derived for shape refinement, which leads to accurate and rapid deformation of a boundary template toward real object boundary. The simulation results show that the proposed method has better performance than conventional boundary extraction methods.

  • Tag-Annotated Text Search Using Extended Region Algebra

    Katsuya MASUDA  Jun'ichi TSUJII  

     
    PAPER-Information Retrieval

      Vol:
    E92-D No:12
      Page(s):
    2369-2377

    This paper presents algorithms for searching text regions with specifying annotated information in tag-annotated text by using Region Algebra. The original algebra and its efficient algorithms are extended to handle both nested regions and crossed regions. The extensions are necessary for text search by using rich linguistic annotations. We first assign a depth number to every nested tag region to order these regions and write efficient algorithms using the depth number for the containment operations which can treat nested tag regions. Next, we introduce variables for attribute values of tags into the algebra to treat annotations in which attributes indicate another tag regions, and propose an efficient method of treating re-entrancy by incrementally determining values for variables. Our algorithms have been implemented in a text search engine for MEDLINE, which is a large textbase of abstracts in medical science. Experiments in tag-annotated MEDLINE abstracts demonstrate the effectiveness of specifying annotations and the efficiency of our algorithms. The system is made publicly accessible at http://www-tsujii.is.s.u-tokyo.ac.jp/medie/.

  • OTHR Impulsive Interference Suppression in Strong Clutter Background

    Tao LIU  Yu GONG  Yaohuan GONG  

     
    PAPER-Digital Signal Processing

      Vol:
    E92-A No:11
      Page(s):
    2866-2873

    External interferences can severely degrade the performance of an Over-the-horizon radar (OTHR), so suppression of external interferences in strong clutter environment is the prerequisite for the target detection. The traditional suppression solutions usually began with clutter suppression in either time or frequency domain, followed by the interference detection and suppression. Based on this traditional solution, this paper proposes a method characterized by joint clutter suppression and interference detection: by analyzing eigenvalues in a short-time moving window centered at different time position, clutter is suppressed by discarding the maximum three eigenvalues at every time position and meanwhile detection is achieved by analyzing the remained eigenvalues at different position. Then, restoration is achieved by forward-backward linear prediction using interference-free data surrounding the interference position. In the numeric computation, the eigenvalue decomposition (EVD) is replaced by singular values decomposition (SVD) based on the equivalence of these two processing. Data processing and experimental results show its efficiency of noise floor falling down about 10-20 dB.

  • IQ Imbalance Estimation Scheme in the Presence of DC Offset and Frequency Offset in the Frequency Domain

    Mamiko INAMORI  Shuzo TAKAYAMA  Yukitoshi SANADA  

     
    PAPER

      Vol:
    E92-A No:11
      Page(s):
    2688-2696

    Direct conversion receivers in orthogonal frequency division multiplexing (OFDM) systems suffer from direct current (DC) offset, frequency offset, and IQ imbalance. We have proposed an IQ imbalance estimation scheme in the presence of DC offset and frequency offset, which uses preamble signals in the time domain. In this scheme, the DC offset is eliminated by a differential filter. However, the accuracy of IQ imbalance estimation is deteriorated when the frequency offset is small. To overcome this problem, a new IQ imbalance estimation scheme in the frequency domain with the differential filter has been proposed in this paper. The IQ imbalance is estimated with pilot subcarriers. Numerical results obtained through computer simulation show that estimation accuracy and bit error rate (BER) performance can be improved even if the frequency offset is small.

  • A Novel SNR Estimation Technique Associated with Hybrid ARQ

    Qingchun CHEN  Pingzhi FAN  

     
    PAPER-Communication Theory and Signals

      Vol:
    E92-A No:11
      Page(s):
    2895-2909

    By using multiple repeated signal replicas to formulate the accumulative observed noisy signal sequence (AONSS) or the differential observed noisy signal sequence (DONSS) in the hybrid ARQ system, a novel data-aided maximum likelihood (DA ML) SNR estimation and a blind ML SNR estimation technique are proposed for the AWGN channel. It is revealed that the conventional DA ML estimate is a special case of the novel DA ML estimate, and both the proposed DA ML and the proposed blind ML SNR estimation techniques can offer satisfactory SNR estimation without introducing significant additional complexity to the existing hybrid ARQ scheme. Based on the AONSS, both the generalized deterministic and the random Cramer-Rao lower bounds (GCRLBs), which include the traditional Cramer-Rao lower bounds (CRLBs) as special cases, are also derived. Finally, the applicability of the proposed SNR estimation techniques based on the AONSS and the DONSS are validated through numerical analysis and simulation results.

  • An LTE-Band Dual-Antenna Design with an Enhanced Antenna Efficiency

    Jinyong KIM  Kyungho CHUNG  Yochuol HO  Moonil KIM  

     
    LETTER-Antennas and Propagation

      Vol:
    E92-B No:11
      Page(s):
    3554-3556

    A neutralization line is internally added to a 770 MHz LTE-band miniature dual-antenna system to improve its antenna efficiency. The odd-mode antenna impedance simulations indicate that the position of the neutralization line along the radiating structure determines the operation frequency. Measurement results show that the line reduces the antenna coupling loss from -6 to -17 dB while improving the individual antenna efficiency from 42 to 65 percent at 770 MHz.

  • Characterization of Left-Handed Traveling-Wave Transistors

    Shun NAKAGAWA  Koichi NARAHARA  

     
    PAPER-Microwaves, Millimeter-Waves

      Vol:
    E92-C No:11
      Page(s):
    1396-1400

    The characteristics of a left-handed traveling-wave transistor, which is formulated as two composite right- and left-handed (CRLH) transmission lines with both passive and active couplings, are discussed for generating unattenuated waves having left-handedness. The design criteria for convective instability are described, together with results of numerical calculations that solve the transmission equation for the device.

  • Antenna Beam Pattern Characteristics of HAPS User Terminal

    Bon-Jun KU  Dae Sub OH  Nam KIM  Do-Seob AHN  

     
    LETTER

      Vol:
    E92-B No:11
      Page(s):
    3394-3396

    High Altitude Platform Stations (HAPS) are recently considered as a green infrastructure to provide high speed multimedia services. The critical issue of HAPS is frequency sharing with satellite systems. Regulating antenna beam pattern using adaptive antenna schemes is one of means to facilitate the sharing with a space receiver for fixed satellite services on the uplink of a HAPS system operating in U bands. In this letter, we investigate antenna beam pattern characteristics of HAPS user terminals with various values of scan angles of main beam, null position angles, and null width.

  • Error Probability of MRC in Frequency Selective Nakagami Fading in the Presence of CCI and ACI

    Mohammad Azizur RAHMAN  Chin-Sean SUM  Ryuhei FUNADA  Shigenobu SASAKI  Tuncer BAYKAS  Junyi WANG  Hiroshi HARADA  Shuzo KATO  

     
    PAPER

      Vol:
    E92-A No:11
      Page(s):
    2679-2687

    An exact expression of error rate is developed for maximal ratio combining (MRC) in an independent but not necessarily identically distributed frequency selective Nakagami fading channel taking into account inter-symbol, co-channel and adjacent channel interferences (ISI, CCI and ACI respectively). The characteristic function (CF) method is adopted. While accurate analysis of MRC performance cannot be seen in frequency selective channel taking ISI (and CCI) into account, such analysis for ACI has not been addressed yet. The general analysis presented in this paper solves a problem of past and present interest, which has so far been studied either approximately or in simulations. The exact method presented also lets us obtain an approximate error rate expression based on Gaussian approximation (GA) of the interferences. It is shown, especially while the channel is lightly faded, has fewer multipath components and a decaying delay profile, the GA may be substantially inaccurate at high signal-to-noise ratio. However, the exact results also reveal an important finding that there is a range of parameters where the simpler GA is reasonably accurate and hence, we don't have to go for more involved exact expression.

8621-8640hit(20498hit)