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[Keyword] SCE(344hit)

101-120hit(344hit)

  • Scenario Generation Using Differential Scenario Information

    Masayuki MAKINO  Atsushi OHNISHI  

     
    PAPER

      Vol:
    E95-D No:4
      Page(s):
    1044-1051

    A method of generating scenarios using differential scenaro information is presented. Behaviors of normal scenarios of similar purpose are quite similar each other, while actors and data in scenarios are different among these scenarios. We derive the differential information between them and apply the differential information to generate new alternative/exceptional scenarios. Our method will be illustrated with examples. This paper describes (1) a language for describing scenarios based on a simple case grammar of actions, (2) introduction of the differential scenario, and (3) method and examples of scenario generation using the differential scenario.

  • Algorithm of Determining BER-Minimized Block Delay for Joint Linear Transceiver Design with CSI

    Chun-Hsien WU  

     
    LETTER-Digital Signal Processing

      Vol:
    E95-A No:3
      Page(s):
    657-660

    This letter proposes an algorithm of determining the BER-minimized block delay for detection and the associated precoder design once the channel state information and limited transmission power are given. Simulation cases demonstrate the adjusting capability of the proposed algorithm for achieving best BER performance of the joint linear transceiver design.

  • Broadband Light Source Based on Four-Color Self-Assembled InAs Quantum Dot Ensembles Monolithically Grown in Selective Areas

    Nobuhiko OZAKI  Koichi TAKEUCHI  Shunsuke OHKOUCHI  Naoki IKEDA  Yoshimasa SUGIMOTO  Kiyoshi ASAKAWA  Richard A. HOGG  

     
    BRIEF PAPER

      Vol:
    E95-C No:2
      Page(s):
    247-250

    We developed advanced techniques for the growth of self-assembled quantum dots (QDs) for fabricating a broadband light source that can be applied to optical coherence tomography (OCT). Four QD ensembles and strain reducing layers (SRLs) were grown in selective areas on a wafer by the use of a 90° rotational metal mask. The SRL thickness was varied to achieve appropriate shifts in the peak wavelength of the QD emission spectrum of up to 120 nm. The four-color QD ensembles were expected to have a broad bandwidth of more than 160 nm due to the combination of excited state emissions when introduced in a current-induced broadband light source such as a superluminescent diode (SLD). Furthermore, a desired shape of the SLD spectrum can be obtained by controlling the injection current applied to each QD ensemble. The broadband and spectrum shape controlled light source is promising for high-resolution and low-noise OCT systems.

  • Precoding Scheme Robust to Imperfect CSI in Downlink Multiuser MIMO-OFDM System

    Linchen CHANG  Kazuhiko FUKAWA  Hiroshi SUZUKI  Satoshi SUYAMA  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E94-B No:12
      Page(s):
    3515-3524

    This paper proposes a precoding scheme for downlink multiuser MIMO-OFDM systems. The proposed precoding employs the minimum average bit error rate (MABER) criterion, and obtains precoding matrices by the steepest descent algorithm in order to minimize average BER of mobile stations. As the cost function of the proposed scheme, an upper bound of the average BER is derived from the pairwise error probability (PEP) and is averaged with respect to channel state information (CSI) errors. Thus, the MABER scheme is robust against imperfect CSI. Computer simulations under a frequency-selective fading condition demonstrate that the proposed precoder is more robust against the CSI errors than both the zero-forcing (ZF) precoder and a robust sum mean square error (SMSE) precoder, and that it is superior in BER to the conventional schemes.

  • Alkoxyphenyl Group-Containing Starburst Host Materials for Efficient Blue and Green Organic Light-Emitting Devices

    Hisahiro SASABE  Masatoshi ISHIBA  Yong-Jin PU  Junji KIDO  

     
    BRIEF PAPER

      Vol:
    E94-C No:12
      Page(s):
    1848-1850

    We designed and synthesized alkoxyphenyl group containing starburst host materials 1. Using 1 as a host material, efficient phosphorescent OLEDs with the power efficiencies of 32 lm W-1 for blue, and 85 lm W-1 for green at 100 cd m-2 were developed.

  • Nano-Structured Organic Devises and Biosensors Utilizing Evanescent Waves and Surface Plasmon Resonance Open Access

    Futao KANEKO  Akira BABA  Kazunari SHINBO  Keizo KATO  

     
    INVITED PAPER

      Vol:
    E94-C No:12
      Page(s):
    1824-1831

    In this review, we introduce a variety of surface sensitive techniques for the study of organic thin films, and applications to organic devices. These studies include surface plasmon emission light, organic thin film transistors, combination of quartz crystal microbalance and optical waveguide spectroscopy, evaluation of alignment of liquid crystal molecules at surfaces, and biosensor applications.

  • 3D Face and Motion from Feature Points Using Adaptive Constrained Minima

    Varin CHOUVATUT  Suthep MADARASMI  Mihran TUCERYAN  

     
    PAPER-Image, Vision

      Vol:
    E94-A No:11
      Page(s):
    2207-2219

    This paper presents a novel method for reconstructing 3D geometry of camera motion and human-face model from a video sequence. The approach combines the concepts of Powell's line minimization with gradient descent. We adapted the line minimization with bracketing used in Powell's minimization to our method. However, instead of bracketing and searching deep down a direction for the minimum point along that direction as done in their line minimization, we achieve minimization by bracketing and searching for the direction in the bracket which provides a lower energy than the previous iteration. Thus, we do not need a large memory as required by Powell's algorithm. The approach to moving in a better direction is similar to classical gradient descent except that the derivative calculation and a good starting point are not needed. The system's constraints are also used to control the bracketing direction. The reconstructed solution is further improved using the Levenberg Marquardt algorithm. No average face model or known-coordinate markers are needed. Feature points defining the human face are tracked using the active appearance model. Occluded points, even in the case of self occlusion, do not pose a problem. The reconstructed space is normalized where the origin can be arbitrarily placed. To use the obtained reconstruction, one can rescale the computed volume to a known scale and transform the coordinate system to any other desired coordinates. This is relatively easy since the 3D geometry of the facial points and the camera parameters of all frames are explicitly computed. Robustness to noise and lens distortion, and 3D accuracy are also demonstrated. All experiments were conducted with an off-the-shelf digital camera carried by a person walking without using any dolly to demonstrate the robustness and practicality of the method. Our method does not require a large memory or the use of any particular, expensive equipment.

  • Image Categorization Using Scene-Context Scale Based on Random Forests

    Yousun KANG  Hiroshi NAGAHASHI  Akihiro SUGIMOTO  

     
    PAPER-Image Recognition, Computer Vision

      Vol:
    E94-D No:9
      Page(s):
    1809-1816

    Scene-context plays an important role in scene analysis and object recognition. Among various sources of scene-context, we focus on scene-context scale, which means the effective scale of local context to classify an image pixel in a scene. This paper presents random forests based image categorization using the scene-context scale. The proposed method uses random forests, which are ensembles of randomized decision trees. Since the random forests are extremely fast in both training and testing, it is possible to perform classification, clustering and regression in real time. We train multi-scale texton forests which efficiently provide both a hierarchical clustering into semantic textons and local classification in various scale levels. The scene-context scale can be estimated by the entropy of the leaf node in the multi-scale texton forests. For image categorization, we combine the classified category distributions in each scale and the estimated scene-context scale. We evaluate on the MSRC21 segmentation dataset and find that the use of the scene-context scale improves image categorization performance. Our results have outperformed the state-of-the-art in image categorization accuracy.

  • Global Selection vs Local Ordering of Color SIFT Independent Components for Object/Scene Classification

    Dan-ni AI  Xian-hua HAN  Guifang DUAN  Xiang RUAN  Yen-wei CHEN  

     
    PAPER-Pattern Recognition

      Vol:
    E94-D No:9
      Page(s):
    1800-1808

    This paper addresses the problem of ordering the color SIFT descriptors in the independent component analysis for image classification. Component ordering is of great importance for image classification, since it is the foundation of feature selection. To select distinctive and compact independent components (IC) of the color SIFT descriptors, we propose two ordering approaches based on local variation, named as the localization-based IC ordering and the sparseness-based IC ordering. We evaluate the performance of proposed methods, the conventional IC selection method (global variation based components selection) and original color SIFT descriptors on object and scene databases, and obtain the following two main results. First, the proposed methods are able to obtain acceptable classification results in comparison with original color SIFT descriptors. Second, the highest classification rate can be obtained by using the global selection method in the scene database, while the local ordering methods give the best performance for the object database.

  • Noise Robust Gradient Descent Learning for Complex-Valued Associative Memory

    Masaki KOBAYASHI  Hirofumi YAMADA  Michimasa KITAHARA  

     
    LETTER-Nonlinear Problems

      Vol:
    E94-A No:8
      Page(s):
    1756-1759

    Complex-valued Associative Memory (CAM) is an advanced model of Hopfield Associative Memory. The CAM is based on multi-state neurons and has the high ability of representation. Lee proposed gradient descent learning for the CAM to improve the storage capacity. It is based on only the phases of input signals. In this paper, we propose another type of gradient descent learning based on both the phases and the amplitude. The proposed learning method improves the noise robustness and accelerates the learning speed.

  • A Wide Dynamic Range Variable Gain Amplifier with Enhanced IP1 dB and Temperature Compensation

    Hisayasu SATO  Takaya MARUYAMA  Toshimasa MATSUOKA  Kenji TANIGUCHI  

     
    PAPER-Integrated Electronics

      Vol:
    E94-C No:8
      Page(s):
    1311-1319

    This paper presents the design consideration of a four-stage variable gain amplifier (VGA) with a wide dynamic range for receivers. The VGA uses parallel amplifiers for the first and second amplifiers in order to improve the input third-order intercept point (IIP3) in the low gain region. To investigate the behavior of the VGA, the gain and linearity analyses are newly derived for the parallel amplifiers, and are compared with the measured results. In addition, the principle of the temperature compensation is described. The gain control range of 110 dB, the IP1 dB of -11 dBm, and noise figure (NF) of 5.1 dB were measured using a 0.5 µm 26 GHz fT BiCMOS process.

  • A 4.7 µA Quiescent Current, 450 mA CMOS Low-Dropout Regulator with Fast Transient Response

    Sau Siong CHONG  Hendra KWANTONO  Pak Kwong CHAN  

     
    PAPER-Electronic Circuits

      Vol:
    E94-C No:8
      Page(s):
    1271-1281

    This paper presents a new low-dropout (LDO) regulator with low-quiescent, high-drive and fast-transient performance. This is based on a new composite power transistor composed of a shunt feedback class-AB embedded gain stage and the application of dynamic-biasing schemes to both the error amplifier as well as the composite power transistor. The proposed LDO regulator has been simulated and validated using BSIM3 models and GLOBALFOUNDRIES 0.18-µm CMOS process. The simulation results have shown that the LDO regulator consumes 4.7 µA quiescent current at no load, regulating the output at 1 V from a minimum 1.2 V supply. It is able to deliver up to 450 mA load current with a dropout of 200 mV. It can be stabilized using a 4.7 µF output capacitor with a 0.1 Ω ESR resistor. The maximum transient output voltage is 64.6 mV on the basis of a load step change of 450 mA/10 ns under typical condition. The full load transient response is less than 350 ns.

  • Scene Categorization with Classified Codebook Model

    Xu YANG  De XU  Songhe FENG  Yingjun TANG  Shuoyan LIU  

     
    LETTER-Image Recognition, Computer Vision

      Vol:
    E94-D No:6
      Page(s):
    1349-1352

    This paper presents an efficient yet powerful codebook model, named classified codebook model, to categorize natural scene category. The current codebook model typically resorts to large codebook to obtain higher performance for scene categorization, which severely limits the practical applicability of the model. Our model formulates the codebook model with the theory of vector quantization, and thus uses the famous technique of classified vector quantization for scene-category modeling. The significant feature in our model is that it is beneficial for scene categorization, especially at small codebook size, while saving much computation complexity for quantization. We evaluate the proposed model on a well-known challenging scene dataset: 15 Natural Scenes. The experiments have demonstrated that our model can decrease the computation time for codebook generation. What is more, our model can get better performance for scene categorization, and the gain of performance becomes more pronounced at small codebook size.

  • Iterative Minimum Mean Square Error Interference Alignment Scheme for the MIMO X Channel

    Hui SHEN  Bin LIN  Yi LUO  Feng LIU  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E94-B No:5
      Page(s):
    1348-1354

    In this paper, we propose a new interference alignment (IA) scheme that jointly designs the linear transmitter and receiver for the 2-user MIMO X channel system, using minimum total mean square error criterion, subject to each transmitter power constraint. We show that transmitters and receivers under such criteria could be realized through a joint iterative algorithm. Considering the imperfection of channel state information (CSI), we also extend the minimum mean square error interference alignment schemes for the MIMO X channel with CSI estimation error. A robust iterative algorithm which is insensitve to CSI estimation error is proposed. Simulation results are also provided to demonstrate the proposed algorithm.

  • High Power and Stable High Coupling Efficiency (66%) Superluminescent Light Emitting Diodes by Using Active Multi-Mode Interferometer

    Zhigang ZANG  Keisuke MUKAI  Paolo NAVARETTI  Marcus DUELK  Christian VELEZ  Kiichi HAMAMOTO  

     
    BRIEF PAPER

      Vol:
    E94-C No:5
      Page(s):
    862-864

    The fabricated 1.55 µm high power superluminescent light emitting diodes (SLEDs) with 115 mW maximum output power and 3 dB bandwidth of 50 nm, using active multi-mode interferometer (MMI), showed high coupling efficiency of 66% into single-mode fiber, which resulted in maximum fiber-coupled power of 77 mW.

  • A Low-Overhead and Low-Power RF Transceiver for Short-Distance On- and Off-Chip Interconnects

    Jongsun KIM  Gyungsu BYUN  M. Frank CHANG  

     
    BRIEF PAPER

      Vol:
    E94-C No:5
      Page(s):
    854-857

    One of the most difficult problems that remains to be solved in wire interconnect architectures is the achievement of lower latency and higher concurrency on a shared bus or link without increasing the power and circuit overhead. Novel improvements in short distance on- and off-chip interconnects can be provided by using a multi-band RF interconnect (RF-I) system. Unlike the conventional current- or voltage-mode square wave signaling transceivers that use binary or multilevel baseband signals, the proposed RF-I transceiver uses high-frequency modulated RF passband signals with binary phase-shift keying (BPSK) modulation. The proposed low-overhead RF-I transceiver using 0.18-µm CMOS technology achieves an aggregate data rate of 4 Gb/s/pin between four I/Os (2Tx-to-2Rx) on a shared FR4 PCB line using two carriers of 6 GHz and 12 GHz. The two transceivers occupy an area of 0.077 mm2 and dissipate a power of about 25 mW with a power efficiency of 6.25 pJ/bit.

  • Query Expansion and Text Mining for ChronoSeeker -- Search Engine for Future/Past Events --

    Hideki KAWAI  Adam JATOWT  Katsumi TANAKA  Kazuo KUNIEDA  Keiji YAMADA  

     
    PAPER

      Vol:
    E94-D No:3
      Page(s):
    552-563

    This paper introduces a future and past search engine, ChronoSeeker, which can help users to develop long-term strategies for their organizations. To provide on-demand searches, we tackled two technical issues: (1) organizing efficient event searches and (2) filtering out noises from search results. Our system employed query expansion with typical expressions related to event information such as year expressions, temporal modifiers, and context terms for efficient event searches. We utilized a machine-learning technique of filtering noise to classify candidates into information or non-event information, using heuristic features and lexical patterns derived from a text-mining approach. Our experiment revealed that filtering achieved an 85% F-measure, and that query expansion could collect dozens more events than those without expansion.

  • RF CMOS Integrated Circuit: History, Current Status and Future Prospects

    Noboru ISHIHARA  Shuhei AMAKAWA  Kazuya MASU  

     
    INVITED PAPER

      Vol:
    E94-A No:2
      Page(s):
    556-567

    As great advancements have been made in CMOS process technology over the past 20 years, RF CMOS circuits operating in the microwave band have rapidly developed from component circuit levels to multiband/multimode transceiver levels. In the next ten years, it is highly likely that the following devices will be realized: (i) versatile transceivers such as those used in software-defined radios (SDR), cognitive radios (CR), and reconfigurable radios (RR); (ii) systems that operate in the millimeter-wave or terahertz-wave region and achieve high speed and large-capacity data transmission; and (iii) microminiaturized low-power RF communication systems that will be extensively used in our everyday lives. However, classical technology for designing analog RF circuits cannot be used to design circuits for the abovementioned devices since it can be applied only in the case of continuous voltage and continuous time signals; therefore, it is necessary to integrate the design of high-speed digital circuits, which is based on the use of discrete voltages and the discrete time domain, with analog design, in order to both achieve wideband operation and compensate for signal distortions as well as variations in process, power supply voltage, and temperature. Moreover, as it is thought that small integration of the antenna and the interface circuit is indispensable to achieve miniaturized micro RF communication systems, the construction of the integrated design environment with the Micro Electro Mechanical Systems (MEMS) device etc. of the different kind devices becomes more important. In this paper, the history and the current status of the development of RF CMOS circuits are reviewed, and the future status of RF CMOS circuits is predicted.

  • The Precoder Design for Intrablock MMSE Equalization and Block Delay Detection with a Modified Oblique Projection Framework

    Chun-Hsien WU  

     
    LETTER-Digital Signal Processing

      Vol:
    E94-A No:2
      Page(s):
    829-832

    This letter presents a method to enable the precoder design for intrablock MMSE equalization with previously proposed oblique projection framework. The joint design of the linear transceiver with optimum block delay detection is built. Simulation results validate the proposed approach and show the superior BER performance of the optimized transceiver.

  • Surface Plasmon Excitation and Emission Light Properties Using Hybrid Setup of Prism and Grating Coupling

    Kazunari SHINBO  Yuta HIRANO  Masayuki SAKAI  Masahiro MINAGAWA  Yasuo OHDAIRA  Akira BABA  Keizo KATO  Futao KANEKO  

     
    BRIEF PAPER

      Vol:
    E94-C No:2
      Page(s):
    196-197

    A half-cylindrical BK-7 prism/dielectric film with a grating/Ag film/fluorescent polymer film structure was prepared, and its surface plasmon (SP) excitation property was investigated. It was confirmed experimentally that SP excitations are possible in this structure by using prism and grating couplings. The SP excitation property depended on the direction of the grating vector. Furthermore, intense photoluminescence was observed when the SPs were simultaneously excited at the Ag/polymer interface by prism coupling and at the Cytop/Ag interface by grating coupling.

101-120hit(344hit)