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[Keyword] ATI(18690hit)

8941-8960hit(18690hit)

  • Complexity Oscillations in Random Reals

    ChenGuang LIU  Kazuyuki TANAKA  

     
    LETTER-Complexity Theory

      Vol:
    E91-D No:10
      Page(s):
    2517-2518

    The C-oscillation due to Martin-Löf shows that {α| ∀ n [C(α n)≥ n-O(1)]=, which also follows {α| ∀ n [K(α n)≥ n+K(n)-O(1)]=. By generalizing them, we show that there does not exist a real α such that ∀ n (K(α n)≥ n+λ K(n)-O(1)) for any λ>0.

  • Secure and Reliable Broadcasting Based on Cooperative Diversity in Wireless Ad Hoc Networks

    Taejoon PARK  

     
    LETTER-Network

      Vol:
    E91-B No:10
      Page(s):
    3338-3341

    In wireless ad hoc networks, providing an authentication service to verify that the broadcast packet is from the claimed sender without modification, is challenging due mainly to the inherently lossy wireless links. This paper presents a novel Secure and Reliable Broadcasting that reinforces the broadcast authentication with reliability and energy-efficiency capabilities by using the cooperative diversity to superimpose two distinct signals. The proposed protocol achieves significant savings of transmission power and fair assurance of reliability among receivers.

  • Design and Implementation of a Non-pipelined MD5 Hardware Architecture Using a New Functional Description

    Ignacio ALGREDO-BADILLO  Claudia FEREGRINO-URIBE  Rene CUMPLIDO  Miguel MORALES-SANDOVAL  

     
    LETTER-VLSI Systems

      Vol:
    E91-D No:10
      Page(s):
    2519-2523

    MD5 is a cryptographic algorithm used for authentication. When implemented in hardware, the performance is affected by the data dependency of the iterative compression function. In this paper, a new functional description is proposed with the aim of achieving higher throughput by mean of reducing the critical path and latency. This description can be used in similar structures of other hash algorithms, such as SHA-1, SHA-2 and RIPEMD-160, which have comparable data dependence. The proposed MD5 hardware architecture achieves a high throughput/area ratio, results of implementation in an FPGA are presented and discussed, as well as comparisons against related works.

  • MR-MIL: Manifold Ranking Based Multiple-Instance Learning for Automatic Image Annotation

    Yufeng ZHAO  Yao ZHAO  Zhenfeng ZHU  Jeng-Shyang PAN  

     
    LETTER-Image

      Vol:
    E91-A No:10
      Page(s):
    3088-3089

    A novel automatic image annotation (AIA) scheme is proposed based on multiple-instance learning (MIL). For a given concept, manifold ranking (MR) is first employed to MIL (referred as MR-MIL) for effectively mining the positive instances (i.e. regions in images) embedded in the positive bags (i.e. images). With the mined positive instances, the semantic model of the concept is built by the probabilistic output of SVM classifier. The experimental results reveal that high annotation accuracy can be achieved at region-level.

  • Analysis and Approximation of Statistical Distribution of Eigenvalues in i.i.d. MIMO Channels under Rayleigh Fading

    Tetsuki TANIGUCHI  Shen SHA  Yoshio KARASAWA  

     
    PAPER-Communication Theory

      Vol:
    E91-A No:10
      Page(s):
    2808-2817

    In multiple input multiple output (MIMO) communication systems, eigenvalues of channel correlation matrices play an essential role for the performance analysis, and particularly the investigation about their behavior under time-variant environment ruled by a certain statistics is an important problem. This paper first gives the theoretical expressions for the marginal distributions of all the ordered eigenvalues of MIMO correlation matrices under i.i.d. (independent and identically distributed) Rayleigh fading environment. Then, an approximation method of those marginal distributions is presented: We show that the theory of SIMO space diversity using maximal ratio combining (MRC) is applicable to the approximation of statistical distributions of all eigenvalues in MIMO systems with the same number of diversity branches. The derived approximation has a monomial form suitable for the calculation of various performance measures utilized in MIMO systems. Through computer simulations, the effectiveness of the proposed method is demonstrated.

  • Indirectly Reactive Sputtering Coater for High Quality Optical Coatings

    Kei-ichi C. NAMIKI  Xinbin CHENG  Haruo TAKAHASHI  

     
    LETTER

      Vol:
    E91-C No:10
      Page(s):
    1673-1674

    An indirectly reactive sputtering coater has been developed to deposit various high quality metallic and metal oxide films at high deposition rate. In this letter, several kinds of filters such as antireflection (AR) coating, IR-cut filter, and Rugate filter were deposited for the benchmark test of implemental capabilities. Our coater was established to be a powerful tool for both discrete multilayer and Rugate filters due to high stability and reproducibility of the refractive index and the deposition rate.

  • A Support Vector Machine-Based Gender Identification Using Speech Signal

    Kye-Hwan LEE  Sang-Ick KANG  Deok-Hwan KIM  Joon-Hyuk CHANG  

     
    LETTER-Fundamental Theories for Communications

      Vol:
    E91-B No:10
      Page(s):
    3326-3329

    We propose an effective voice-based gender identification method using a support vector machine (SVM). The SVM is a binary classification algorithm that classifies two groups by finding the voluntary nonlinear boundary in a feature space and is known to yield high classification performance. In the present work, we compare the identification performance of the SVM with that of a Gaussian mixture model (GMM)-based method using the mel frequency cepstral coefficients (MFCC). A novel approach of incorporating a features fusion scheme based on a combination of the MFCC and the fundamental frequency is proposed with the aim of improving the performance of gender identification. Experimental results demonstrate that the gender identification performance using the SVM is significantly better than that of the GMM-based scheme. Moreover, the performance is substantially improved when the proposed features fusion technique is applied.

  • Azimuthal and Elevation Localization Using Inter-Channel Phase and Level Differences for a Hemispheric Object

    Yoshifumi CHISAKI  Toshimichi TAKADA  Masahiro NAGANISHI  Tsuyoshi USAGAWA  

     
    LETTER-Engineering Acoustics

      Vol:
    E91-A No:10
      Page(s):
    3059-3062

    The frequency domain binaural model (FDBM) has been previously proposed to localize multiple sound sources. Since the method requires only two input signals and uses interaural phase and level differences caused by the diffraction generated by the head, flexibility in application is very high when the head is considered as an object. When an object is symmetric with respect to the two microphones, the performance of sound source localization is degraded, as a human being has front-back confusion due to the symmetry in a median plane. This paper proposes to reduce the degradation of performance on sound source localization by a combination of the microphone pair outputs using the FDBM. The proposed method is evaluated by applying to a security camera system, and the results showed performance improvement in sound source localization because of reducing the number of cones of confusion.

  • A Method for Recognizing Noisy Romanized Japanese Words in Learner English

    Ryo NAGATA  Jun-ichi KAKEGAWA  Hiromi SUGIMOTO  Yukiko YABUTA  

     
    PAPER-Educational Technology

      Vol:
    E91-D No:10
      Page(s):
    2458-2466

    This paper describes a method for recognizing romanized Japanese words in learner English. They become noise and problematic in a variety of systems and tools for language learning and teaching including text analysis, spell checking, and grammatical error detection because they are Japanese words and thus mostly unknown to such systems and tools. A problem one encounters when recognizing romanized Japanese words in learner English is that the spelling rules of romanized Japanese words are often violated. To address this problem, the described method uses a clustering algorithm reinforced by a small set of rules. Experiments show that it achieves an F-measure of 0.879 and outperforms other methods. They also show that it only requires the target text and an English word list of reasonable size.

  • An Estimation Method of Parameters for Closed-box Loudspeaker System

    Rika NAKAO  Yoshinobu KAJIKAWA  Yasuo NOMURA  

     
    PAPER-Engineering Acoustics

      Vol:
    E91-A No:10
      Page(s):
    3006-3013

    In this paper, we propose a method that uses Simulated Annealing (SA) to estimate the linear and nonlinear parameters of a closed-box loudspeaker system for implementing effective Mirror filters. The nonlinear parameters determined by W. Klippel's method are sometimes inaccurate and imaginary. In contrast, the proposed method can estimate the parameters with satisfactory accuracy due to its use of SA; the resulting impedance and displacement characteristics match those of an actual equivalent loudspeaker. A Mirror filter designed around these parameters can well compensate the nonlinear distortions of the loudspeaker system. Experiments demonstrate that the method can reduce the levels of nonlinear distortion by 5 dB to 20 dB compared to the before compensation condition.

  • Eigenpolarization States of Photoinduced Anisotropy in Azobenzene Film

    Daisuke BARADA  Kiyonobu TAMURA  Takashi FUKUDA  Akira EMOTO  Toyohiko YATAGAI  

     
    LETTER

      Vol:
    E91-C No:10
      Page(s):
    1675-1676

    Optical anisotropy was induced in azobenzene copolymer film using linearly or elliptically polarized laser beams. The Jones matrix of the anisotropic film was calculated from the change in polarization of the probe light. Two eigenpolarization states were obtained from the matrix. These two eigenstates are useful as a polarization basis for a polarization-tunable component.

  • An Opportunistic Forwarding Scheme Exploiting both Long Progress and Adaptive Rate in Wireless Networks

    Suhua TANG  Mehdad N. SHIRAZI  Oyunchimeg SHAGDAR  Ryutaro SUZUKI  Sadao OBANA  

     
    PAPER-Network

      Vol:
    E91-B No:10
      Page(s):
    3241-3250

    In Mobile Ad hoc Networks (MANET) geographic routing is characterized by local forwarding decision. Links with a long progress are preferred under the greedy forwarding rule. However in a real system long links tend to have a high packet loss rate due to multipath fading. A sub-optimal solution may separately exploit path diversity or rate adaptation. In this paper we study channel efficiency of multi-hop forwarding and try to jointly optimize rate adaptation and forwarder selection in geographic routing by the tradeoff between progress and instantaneous rate. We define a new metric -- Bit Transfer Speed (BTS) -- as the ratio of the progress made towards the destination to the equivalent time taken to transfer a payload bit. This metric takes overhead, rate and progress into account. Then we propose a packet forwarding scheme that Opportunistically exploits both long Progress and Adaptive Rate (OPAR) by a cross-layer design of routing and MAC. In OPAR each node selects for a packet the forwarder with the highest BTS. The forwarder changes as local topology (progress), packet size (overhead ratio) or channel state (data rate) varies. Simulation results show that compared with the normalized advance (NADV) [7] scheme and contention-based forwarding (CBF) [17] scheme, OPAR has lower packet loss and can effectively reduce channel occupation time by over 30% in the scenario with moderate mobility speeds.

  • Achievements and Challenges in the Design and Production of High Quality Optical Coatings

    Alexander TIKHONRAVOV  Michael TRUBETSKOV  Ichiro KASAHARA  

     
    INVITED PAPER

      Vol:
    E91-C No:10
      Page(s):
    1622-1629

    A new paradigm in the design of optical coatings connected with an outstanding computational efficiency of modern design techniques is discussed. Several other topics including pre-production error analysis, monitoring of coating production, and computational manufacturing of optical coatings are considered.

  • Skin Color Segmentation Using Coarse-to-Fine Region on Normalized RGB Chromaticity Diagram for Face Detection

    Aryuanto SOETEDJO  Koichi YAMADA  

     
    PAPER-Image Recognition, Computer Vision

      Vol:
    E91-D No:10
      Page(s):
    2493-2502

    This paper describes a new color segmentation based on a normalized RGB chromaticity diagram for face detection. Face skin is extracted from color images using a coarse skin region with fixed boundaries followed by a fine skin region with variable boundaries. Two newly developed histograms that have prominent peaks of skin color and non-skin colors are employed to adjust the boundaries of the skin region. The proposed approach does not need a skin color model, which depends on a specific camera parameter and is usually limited to a particular environment condition, and no sample images are required. The experimental results using color face images of various races under varying lighting conditions and complex backgrounds, obtained from four different resources on the Internet, show a high detection rate of 87%. The results of the detection rate and computation time are comparable to the well known real-time face detection method proposed by Viola-Jones [11],[12].

  • Scalable Video Streaming Adaptive to Time-Varying IEEE 802.11 MAC Parameters

    Kyung-Jun LEE  Doug-Young SUH  Gwang-Hoon PARK  Jae-Doo HUH  

     
    LETTER-Multimedia Systems for Communications

      Vol:
    E91-B No:10
      Page(s):
    3404-3408

    This letter proposes a QoS control method for video streaming service over wireless networks. Based on statistical analysis, the time-varying MAC parameters highly related to channel condition are selected to predict available bitrate. Adaptive bitrate control of scalably-encoded video guarantees continuity in streaming service even if the channel condition changes abruptly.

  • Enhanced Class-of-Service Oriented Packet Scheduling Scheme for EPON Access Networks

    Intark HAN  Hong-Shik PARK  Man-Soo HAN  

     
    LETTER-Fiber-Optic Transmission for Communications

      Vol:
    E91-B No:10
      Page(s):
    3334-3337

    A fast class-of-service oriented packet scheduling (FCOPS) has a service fairness problem since a credit pool for a service class is initialized at the beginning of a transmission cycle whose starting moment is fixed at a specific ONU. To remedy the service unfairness of FCOPS, we suggest an enhanced class-of-service oriented packet scheduling (ECOPS) that uses a new initialization cycle whose starting moment is fairly distributed to each ONU. Also, ECOPS generates a colorless grant to utilize the resource wastage, when traffic is light and the total sum of grants of an ONU is less than a minimum size. Using simulation, we validate ECOPS as superior to FCOPS in the mean delay and the service fairness.

  • An Illumination-Adaptive Colorimetric Measurement Using Color Image Sensor

    Sung-Hak LEE  Jong-Hyub LEE  Kyu-Ik SOHNG  

     
    LETTER

      Vol:
    E91-C No:10
      Page(s):
    1608-1610

    An image sensor for a use of colorimeter is characterized based on the CIE standard colorimetric observer. We use the method of least squares to derive a colorimetric characterization matrix between RGB output signals and CIE XYZ tristimulus values. This paper proposes an adaptive measuring method to obtain the chromaticity of colored scenes and illumination through a 33 camera transfer matrix under a certain illuminant. Camera RGB outputs, sensor status values, and photoelectric characteristic are used to obtain the chromaticity. Experimental results show that the proposed method is valid in the measuring performance.

  • Adaptive Transmission with Mixed Band-AMC and Diversity Modes for Multiuser OFDMA

    Sung Bo SIM  Yun Hee KIM  Kwang Soon KIM  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E91-B No:9
      Page(s):
    3021-3024

    In this letter, we propose an adaptive transmission method for an OFDMA system supporting both band-AMC and diversity modes in a frame, simultaneously. In the proposed method, users are classified into the two groups preferring the band-AMC mode or the diversity mode based on their channel parameters. Then the BS performs resource allocation to maximize the throughput. It is observed that the proposed adaptive transmission method can reduce the feedback overhead with negligible performance loss.

  • Near-Field to Far-Field Transformation for an Outdoor RCS Range

    Yoshio INASAWA  Shinji KURODA  Ken-ichi KAKIZAKI  Hitoshi NISHIKAWA  Naofumi YONEDA  Shigeru MAKINO  

     
    PAPER-Electromagnetic Theory

      Vol:
    E91-C No:9
      Page(s):
    1463-1471

    This paper presents the near-field to far-field transformation for an outdoor radar cross section (RCS) range. Direct measurement of the large actual target requires quite a long measurement range. The near-field to far-field RCS transformation method achieves the reduction of measurement range. However the non-uniformity of the incident electric field distribution on the target causes some errors in RCS prediction. We propose a novel near-field to far-field RCS transformation method that can be applied to an outdoor RCS measurement. The non-uniformity of the incident electric field distribution is successfully resolved by introducing the correction term of the ground bounce. We investigate the validity of the proposed method by the simulation and measurement.

  • New Sequences with Low Correlation and Large Family Size

    Fanxin ZENG  

     
    PAPER-Information Theory

      Vol:
    E91-A No:9
      Page(s):
    2615-2625

    In direct-sequence code-division multiple-access (DS-CDMA) communication systems and direct-sequence ultra wideband (DS-UWB) radios, sequences with low correlation and large family size are important for reducing multiple access interference (MAI) and accepting more active users, respectively. In this paper, a new collection of families of sequences of length pn-1, which includes three constructions, is proposed. The maximum number of cyclically distinct families without GMW sequences in each construction is , where p is a prime number, n is an even number, and n=2m, and these sequences can be binary or polyphase depending upon choice of the parameter p. In Construction I, there are pn distinct sequences within each family and the new sequences have at most d+2 nontrivial periodic correlation {-pm-1,-1,pm-1,2pm-1,,dpm-1}. In Construction II, the new sequences have large family size p2n and possibly take the nontrivial correlation values in {-pm-1,-1,pm-1,2pm-1,,(3d-4)pm-1}. In Construction III, the new sequences possess the largest family size p(d-1)n and have at most 2d correlation levels {-pm-1,-1,pm-1,2pm-1,,(2d-2)pm-1}. Three constructions are near-optimal with respect to the Welch bound because the values of their Welch-Ratios are moderate, WR d, WR 3d-4 and WR 2d-2, respectively. Each family in Constructions I, II and III contains a GMW sequence. In addition, Helleseth sequences and Niho sequences are special cases in Constructions I and III, and their restriction conditions to the integers m and n, pm≠ 2(mod 3) and n≡ 0 (mod 4), respectively, are removed in our sequences. Our sequences in Construction III include the sequences with Niho type decimation 32m-2, too. Finally, some open questions are pointed out and an example that illustrates the performance of these sequences is given.

8941-8960hit(18690hit)