The search functionality is under construction.
The search functionality is under construction.

Keyword Search Result

[Keyword] TE(21534hit)

10081-10100hit(21534hit)

  • Image Enhancement by Analysis on Embedded Surfaces of Images and a New Framework for Enhancement Evaluation

    Li TIAN  Sei-ichiro KAMATA  

     
    PAPER

      Vol:
    E91-D No:7
      Page(s):
    1946-1954

    Image enhancement plays an important role in many machine vision applications on images captured in low contrast and low illumination conditions. In this study, we propose a new method for image enhancement based on analysis on embedded surfaces of images. The proposed method gives an insight into the relationship between the image intensity and image enhancement. In our method, scaled surface area and the surface volume are proposed and used to reconstruct the image iteratively for contrast enhancement, and the illumination of the reconstructed image can also be adjusted simultaneously. On the other hand, the most common methods for measuring the quality of enhanced images are Mean Square Error (MSE) or Peak Signal-to-Noise-Ratio (PSNR) in conventional works. The two measures have been recognized as inadequate ones because they do not evaluate the result in the way that the human vision system does. This paper also presents a new framework for evaluating image enhancement using both objective and subjective measures. This framework can also be used for other image quality evaluations such as denoising evaluation. We compare our enhancement method with some well-known enhancement algorithms, including wavelet and curvelet methods, using the new evaluation framework. The results show that our method can give better performance in most objective and subjective criteria than the conventional methods.

  • A Coupled Dynamical Model of Redox Flow Battery Based on Chemical Reaction, Fluid Flow, and Electrical Circuit

    Minghua LI  Takashi HIKIHARA  

     
    PAPER-Nonlinear Problems

      Vol:
    E91-A No:7
      Page(s):
    1741-1747

    The redox (Reduction-Oxidation) flow battery is one of the most promising rechargeable batteries due to its ability to average loads and output of power sources. The transient characteristics are well known as the remarkable feature of the battery. Then it can also compensate for a sudden voltage drop. The dynamics are governed by the chemical reactions, fluid flow, and electrical circuit of its structure. This causes the difficulty of the analysis at transient state. This paper discusses the transient behavior of the redox flow battery based on chemical reactions. The concentration change of vanadium ions depends on the chemical reactions and the flow of electrolysis solution. The chemical reaction rate is restricted by the attached external electric circuit. In this paper, a model of the transient behavior is introduced. The validity of the derived model is examined based on experiments for a tested micro-redox flow battery system.

  • More Efficient VLR Group Signature Satisfying Exculpability

    Jingliang ZHANG  Lizhen MA  Rong SUN  Yumin WANG  

     
    LETTER-Cryptography and Information Security

      Vol:
    E91-A No:7
      Page(s):
    1831-1835

    In this letter, we improve NF'07 (Nakanishi and Funabiki) VLR group signature scheme such that it satisfies exculpability and has lower computation costs. In the proposed scheme, a group member generates his own private key together with the group manager in order to realize exculpability while the signature size is not made longer. Also, a new revocation check method is proposed at the step of verifying, and the computation costs of verifying are independent of the number of the revoked members, while they are linear with the number of the revoked members in the original scheme. Thus, the proposed scheme is more efficient than the original scheme and can be applicable to mobile environments such as IEEE 802.1x.

  • Energy Efficient Online Routing Algorithm for QoS-Sensitive Sensor Networks

    Sungwook KIM  Sungyong PARK  Sooyong PARK  Sungchun KIM  

     
    LETTER-Network

      Vol:
    E91-B No:7
      Page(s):
    2401-2404

    In this letter, we propose a new energy efficient online routing algorithm for QoS-sensitive sensor networks. An important design principle underlying our algorithm is online decision making based on real time network estimation. This on-line approach gives adaptability and flexibility to solve a wide range of control tasks for efficient network performance. In addition, our distributed control paradigm is practical for real sensor network management. Simulation results indicate the superior performance of our algorithm between energy efficiency and QoS provisioning.

  • Wavelength Conversion Characteristics of SOA-MZI Based All-Optical NRZ-OOK/RZ-BPSK Modulation Format Converter

    Suresh M. NISSANKA  Ken MISHINA  Akihiro MARUTA  Shunsuke MITANI  Kazuyuki ISHIDA  Katsuhiro SHIMIZU  Tatsuo HATTA  Ken-ichi KITAYAMA  

     
    PAPER

      Vol:
    E91-B No:7
      Page(s):
    2160-2164

    All-optical wavelength conversion and modulation format conversion will be needed in the next generation high-speed optical communication networks. We have proposed and successfully demonstrated the error free operation of all-optical modulation format conversion from NRZ-OOK to RZ-BPSK using SOA based MZI wavelength converter. In this paper, we experimentally investigate the wavelength conversion characteristics of the proposed NRZ-OOK/RZ-BPSK modulation format converter. The results show that error free modulation format conversion is possible over the entire C band.

  • Theory and Practice of Rate Division in Distributed Video Coding

    Peng WANG  Jia WANG  Songyu YU  Yuye PANG  

     
    PAPER-Multimedia Environment Technology

      Vol:
    E91-A No:7
      Page(s):
    1806-1811

    Wyner and Ziv characterized the rate distortion function for lossy source coding with side information at the decoder. It is well known that for the quadratic Gaussian case, the Wyner-Ziv rate-distortion function coincides with the conditional rate-distortion function. In this paper, we extend the problem to the coding of multivariate Gaussian source with multiple Gaussian side information at the decoder. The achievable region is obtained, and it is easily extended to the case that the difference between the source and the side information is multivariate Gaussian, no matter what distributions the source and the side information are. We apply this theoretical model to Distributed Video Coding (DVC) by considering the difference of the Distributed frame (D frame) and the Side-information frame (S frame) to be multivariate Gaussian distributed. This introduces rate allocation problem into DVC, which can be solved by a reverse water-filling method. Simulation results show that around 1.5-2 dB coding gain benefits from the multivariate Gaussian Wyner-Ziv coding model.

  • Decomposition of Task-Level Concurrency on C Programs Applied to the Design of Multiprocessor SoC

    Mohammad ZALFANY URFIANTO  Tsuyoshi ISSHIKI  Arif ULLAH KHAN  Dongju LI  Hiroaki KUNIEDA  

     
    PAPER-VLSI Design Technology and CAD

      Vol:
    E91-A No:7
      Page(s):
    1748-1756

    A simple extension used to assist the decomposition of task-level concurrency within C programs is presented in this paper. The concurrency decomposition is meant to be used as the point of entry for Multiprocessor System-on-Chips (MPSoC) architectures' design-flow. Our methodology allows the (re)use of readily available reference C programs and enables easy and rapid exploration for various alternatives of task partitioning strategies; a crucial task that greatly influences the overall quality of the designed MPSoC. A test case using a JPEG encoder application has been performed and the results are presented in this paper.

  • RF Equivalent-Circuit Analysis of p-Type Diamond Field-Effect Transistors with Hydrogen Surface Termination

    Makoto KASU  Kenji UEDA  Hiroyuki KAGESHIMA  Yoshiharu YAMAUCHI  

     
    PAPER-Wide Bandgap Devices

      Vol:
    E91-C No:7
      Page(s):
    1042-1049

    On the basis of the RF characteristics of p-type diamond field-effect transistors (FETs) with hydrogen surface termination, we establish an equivalent circuit (EQC) model. From comparisons of three cases we reveal that to represent the device performance in the EQC, the source, gate, and drain resistance should be considered but that the gate-source and gate-drain resistance can be ignored. The features of diamond FETs are (1) a plateau of the gate capacitance in a certain gate voltage range. (2) maximum fT and fMAX cut-off frequencies near the threshold gate voltage, and (3) a high fMAX/fT ratio 3.8. We discuss these features in terms of the energy barrier between the gate metal and the two-dimensional hole channel and drift region below the gate.

  • An Efficient Index Dissemination in Unstructured Peer-to-Peer Networks

    Yusuke TAKAHASHI  Taisuke IZUMI  Hirotsugu KAKUGAWA  Toshimitsu MASUZAWA  

     
    PAPER-Algorithm Theory

      Vol:
    E91-D No:7
      Page(s):
    1971-1981

    Using Bloom filters is one of the most popular and efficient lookup methods in P2P networks. A Bloom filter is a representation of data item indices, which achieves small memory requirement by allowing one-sided errors (false positive). In the lookup scheme besed on the Bloom filter, each peer disseminates a Bloom filter representing indices of the data items it owns in advance. Using the information of disseminated Bloom filters as a clue, each query can find a short path to its destination. In this paper, we propose an efficient extension of the Bloom filter, called a Deterministic Decay Bloom Filter (DDBF) and an index dissemination method based on it. While the index dissemination based on a standard Bloom filter suffers performance degradation by containing information of too many data items when its dissemination radius is large, the DDBF can circumvent such degradation by limiting information according to the distance between the filter holder and the items holders, i.e., a DDBF contains less information for faraway items and more information for nearby items. Interestingly, the construction of DDBFs requires no extra cost above that of standard filters. We also show by simulation that our method can achieve better lookup performance than existing ones.

  • Bidirectional Gigabit Millimeter-Wave Wavelength Division Multiplexed-Radio over Fiber Link Using a Reflective Semiconductor Optical Amplifier

    Dae-Won LEE  Yong-Yuk WON  Sang-Kook HAN  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E91-B No:7
      Page(s):
    2418-2421

    We propose a new bidirectional gigabit mm-wave wavelength division multiplexed-radio over fiber link which shares the same wavelength. As the downlink, the central station transmits a 30 GHz single sideband wireless signal which is modulated 1.25 Gbps and also transmits a remote 32 GHz local oscillator for down-conversion of a uplink wireless signal by using a mach-zehnder modulator and a fiber bragg grating. As the uplink, the base station transmits a down-converted 1.25 Gbps wireless signal by using a reflective semiconductor optical amplifier. We achieve a BER < 10-9 in the downlink at -14.05 dBm and uplink at -12.5 dBm after 20 km transmission.

  • Fabrication and Characterization of Active and Sequential Circuits Utilizing Schottky-Wrap-Gate-Controlled GaAs Hexagonal Nanowire Network Structures

    Hong-Quan ZHAO  Seiya KASAI  Tamotsu HASHIZUME  Nan-Jian WU  

     
    PAPER-Emerging Devices

      Vol:
    E91-C No:7
      Page(s):
    1063-1069

    For realization of hexagonal BDD-based digital systems, active and sequential circuits including inverters, flip flops and ring oscillators are designed and fabricated on GaAs-based hexagonal nanowire networks controlled by Schottky wrap gates (WPGs), and their operations are characterized. Fabricated inverters show comparatively high transfer gain of more than 10. Clear and correct operation of hexagonal set-reset flip flops (SR-FFs) is obtained at room temperature. Fabricated hexagonal D-type flip flop (D-FF) circuits integrating twelve WPG field effect transistors (FETs) show capturing input signal by triggering although the output swing is small. Oscillatory output is successfully obtained in a fabricated 7-stage hexagonal ring oscillator. Obtained results confirm that a good possibility to realize practical digital systems can be implemented by the present circuit approach.

  • Adopting the Drowsy Technique for Instruction Caches: A Soft Error Perspective

    Soong Hyun SHIN  Sung Woo CHUNG  Eui-Young CHUNG  Chu Shik JHON  

     
    PAPER-VLSI Design Technology and CAD

      Vol:
    E91-A No:7
      Page(s):
    1772-1779

    As technology scales down, leakage energy accounts for a greater proportion of total energy. Applying the drowsy technique to a cache, is regarded as one of the most efficient techniques for reducing leakage energy. However, it increases the Soft Error Rate (SER), thus, many researchers doubt the reliability of the drowsy technique. In this paper, we show several reasons why the instruction cache can adopt the drowsy technique without reliability problems. First, an instruction cache always stores read-only data, leading to soft error recovery by re-fetching the instructions from lower level memory. Second, the effect of the re-fetching caused by soft errors on performance is negligible. Additionally, a considerable percentage of soft errors can occur without harming the performance. Lastly, unrecoverable soft errors can be controlled by the scrubbing method. The simulation results show that the drowsy instruction cache rarely increases the rate of unrecoverable errors and negligibly degrades the performance.

  • An Adaptive Likelihood Distribution Algorithm for the Localization of Passive RFID Tags

    Yuuki OTA  Toshihiro HORI  Taiki ONISHI  Tomotaka WADA  Kouichi MUTSUURA  Hiromi OKADA  

     
    PAPER

      Vol:
    E91-A No:7
      Page(s):
    1666-1675

    The RFID (Radio Frequency IDentification) tag technology is expected as a tool of localization. By the localization of RFID tags, a mobile robot which installs in RFID readers can recognize surrounding environments. In addition, RFID tags can be applied to a navigation system for walkers. In this paper, we propose an adaptive likelihood distribution scheme for the localization of RFID tags. This method adjusts the likelihood distribution depending on the signal intensity from RFID tags. We carry out the performance evaluation of estimated position error by both computer simulations and implemental experiments. We show that the proposed system is more effective than the conventional system.

  • 3D Precise Inspection of Terminal Lead for Electronic Devices by Single Camera Stereo Vision

    Takashi WATANABE  Akira KUSANO  Takayuki FUJIWARA  Hiroyasu KOSHIMIZU  

     
    PAPER

      Vol:
    E91-D No:7
      Page(s):
    1885-1892

    It is very important to guarantee the quality of the industrial products by means of visual inspection. In order to reduce the soldering defect with terminal deformation and terminal burr in the manufacturing process, this paper proposes a 3D visual inspection system based on a stereo vision with single camera. It is technically noted that the base line of this single camera stereo was precisely calibrated by the image processing procedure. Also to extract the measuring point coordinates for computing disparity; the error is reduced with original algorithm. Comparing its performance with that of human inspection using industrial microscope, the proposed 3D inspection could be an alternative in precision and in processing cost. Since the practical specification in 3D precision is less than 1 pixel and the experimental performance was around the same, it was demonstrated by the proposed system that the soldering defect with terminal deformation and terminal burr in inspection, especially in 3D inspection, was decreased. In order to realize the inline inspection, this paper will suggest how the human inspection of the products could be modeled and be implemented by the computer system especially in manufacturing process.

  • Accurate Modeling Method for Cu Interconnect

    Kenta YAMADA  Hiroshi KITAHARA  Yoshihiko ASAI  Hideo SAKAMOTO  Norio OKADA  Makoto YASUDA  Noriaki ODA  Michio SAKURAI  Masayuki HIROI  Toshiyuki TAKEWAKI  Sadayuki OHNISHI  Manabu IGUCHI  Hiroyasu MINDA  Mieko SUZUKI  

     
    PAPER-Semiconductor Materials and Devices

      Vol:
    E91-C No:6
      Page(s):
    968-977

    This paper proposes an accurate modeling method of the copper interconnect cross-section in which the width and thickness dependence on layout patterns and density caused by processes (CMP, etching, sputtering, lithography, and so on) are fully incorporated and universally expressed. In addition, we have developed specific test patterns for the model parameters extraction, and an efficient extraction flow. We have extracted the model parameters for 0.15 µm CMOS using this method and confirmed that 10% τpd error normally observed with conventional LPE (Layout Parameters Extraction) was completely dissolved. Moreover, it is verified that the model can be applied to more advanced technologies (90 nm, 65 nm and 55 nm CMOS). Since the interconnect delay variations due to the processes constitute a significant part of what have conventionally been treated as random variations, use of the proposed model could enable one to greatly narrow the guardbands required to guarantee a desired yield, thereby facilitating design closure.

  • Mechanism of Perceptual Categorization in the Pre-Linguistic Period

    Tamami SUDO  Ken MOGI  

     
    PAPER-Human Information Processing

      Vol:
    E91-D No:6
      Page(s):
    1649-1655

    In this study, we conducted a series of experiments using stimuli characterized by various attributes in order to understand the categorization process in an infant's pre-linguistic development. The infants are able to assign the same label to members within the same category by focusing attention on specific features or functions common to the members. The ability to categorize is likely to play an essential role in an infant's overall cognitive development. Specifically, we investigated how the infants use different strategies in the process of linguistic categorization. In one strategy, members of a single category are derived from perceptual similarities within the most representative members, i.e., the prototypical members. Alternatively, each membership is established by referring to the linguistic labels for each category provided by the caretaker, in a symbol grounding process. We found that the infant is able to employ these strategies in a flexible manner in its development. We discuss the interplay between different cognitive strategies, including the prototype effects in the infant's cognitive development and the implications for cortical mechanism involved.

  • A Two-Microphone Noise Reduction Method in Highly Non-stationary Multiple-Noise-Source Environments

    Junfeng LI  Masato AKAGI  Yoiti SUZUKI  

     
    PAPER

      Vol:
    E91-A No:6
      Page(s):
    1337-1346

    In this paper, we propose a two-microphone noise reduction method to deal with non-stationary interfering noises in multiple-noise-source environments in which the traditional two-microphone algorithms cannot function well. In the proposed algorithm, multiple interfering noise sources are regarded as one virtually integrated noise source in each subband, and the spectrum of the integrated noise is then estimated using its virtual direction of arrival. To do this, we suggest a direction finder for the integrated noise using only two microphones that performs well even in speech active periods. The noise spectrum estimate is further improved by integrating a single-channel noise estimation approach and then subtracted from that of the noisy signal, finally enhancing the desired target signal. The performance of the proposed algorithm is evaluated and compared with the traditional algorithms in various conditions. Experimental results demonstrate that the proposed algorithm outperforms the traditional algorithms in various conditions in terms of objective and subjective speech quality measures.

  • Dive into the Movie

    Shigeo MORISHIMA  

     
    INVITED PAPER

      Vol:
    E91-D No:6
      Page(s):
    1594-1603

    "Dive into the Movie (DIM)" is a name of project to aim to realize a world innovative entertainment system which can provide an immersion experience into the story by giving a chance to audience to share an impression with his family or friends by watching a movie in which all audience can participate in the story as movie casts. To realize this system, several techniques to model and capture the personal characteristics instantly in face, body, gesture, hair and voice by combining computer graphics, computer vision and speech signal processing technique. Anyway, all of the modeling, casting, character synthesis, rendering and compositing processes have to be performed on real-time without any operator. In this paper, first a novel entertainment system, Future Cast System (FCS), is introduced which can create DIM movie with audience's participation by replacing the original roles' face in a pre-created CG movie with audiences' own highly realistic 3D CG faces. Then the effects of DIM movie on audience experience are evaluated subjectively. The result suggests that most of the participants are seeking for higher realism, impression and satisfaction by replacing not only face part but also body, hair and voice. The first experimental trial demonstration of FCS was performed at the Mitsui-Toshiba pavilion of the 2005 World Exposition in Aichi Japan. Then, 1,640,000 people have experienced this event during 6 months of exhibition and FCS became one of the most popular events at Expo.2005.

  • Extending LogicWeb via Hereditary Harrop Formulas

    Keehang KWON  Dae-Seong KANG  

     
    LETTER-Fundamentals of Software and Theory of Programs

      Vol:
    E91-D No:6
      Page(s):
    1827-1829

    We propose HHWeb, an extension to LogicWeb with hereditary Harrop formulas. HHWeb extends the LogicWeb of Loke and Davison by allowing goals of the form ( x1... xn D) G (or equivalently x1... xn(D G)) where D is a web page and G is a goal. This goal is intended to be solved by instantiating x1,...,xn in D by new names and then solving the resulting goal. The existential quantifications at the head of web pages are particularly flexible in controlling the visibility of names. For example, they can provide scope to functions and constants as well as to predicates. In addition, they have such simple semantics that implementation becomes more efficient. Finally, they provide a client-side interface which is useful for customizing web pages.

  • Quantization Parameter Refinement in H.264 through ρ-Domain Rate Model

    Yutao DONG  Xiangzhong FANG  Jing YANG  

     
    LETTER-Speech and Hearing

      Vol:
    E91-D No:6
      Page(s):
    1834-1837

    This letter proposes a new algorithm of refining the quantization parameter in H.264 real-time encoding. In the H.264 encoding, the quantization parameter computed according to the quadratic rate model is not accurate in meeting the target bit rate. In order to make the actual encoded bit rate closer to the target bit rate, ρ-domain rate model is introduced in our proposed quantization parameter refinement algorithm. Simulation results show that the proposed algorithm achieves obvious gain in PSNR and has stabler encoded bit rate compared to Jiang's algorithm.

10081-10100hit(21534hit)