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9101-9120hit(18690hit)

  • 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.

  • Automatic Cell Segmentation Using a Shape-Classification Model in Immunohistochemically Stained Cytological Images

    Shishir SHAH  

     
    PAPER

      Vol:
    E91-D No:7
      Page(s):
    1955-1962

    This paper presents a segmentation method for detecting cells in immunohistochemically stained cytological images. A two-phase approach to segmentation is used where an unsupervised clustering approach coupled with cluster merging based on a fitness function is used as the first phase to obtain a first approximation of the cell locations. A joint segmentation-classification approach incorporating ellipse as a shape model is used as the second phase to detect the final cell contour. The segmentation model estimates a multivariate density function of low-level image features from training samples and uses it as a measure of how likely each image pixel is to be a cell. This estimate is constrained by the zero level set, which is obtained as a solution to an implicit representation of an ellipse. Results of segmentation are presented and compared to ground truth measurements.

  • Precise Top View Image Generation without Global Metric Information

    Hiroshi KANO  Keisuke ASARI  Yohei ISHII  Hitoshi HONGO  

     
    PAPER

      Vol:
    E91-D No:7
      Page(s):
    1893-1898

    We describe a practical and precise calibration method for generating a top view image that is transformed so that a planar object such as the road can be observed from a direction perpendicular to its surface. The geometric relation between the input and output images is described by a 3 3 homography matrix. Conventional methods use large planar calibration patterns to achieve precise transformations. The proposed method uses much smaller element patterns that are placed in arbitrary positions within the view of the camera. One of the patterns is used to obtain an initial homography. Then, the information from all of the patterns is used by a non-linear optimization scheme to reach a global optimum homography. The experiment done to evaluate the method showed that the precision of the proposed method is comparable to that of the conventional method where a large calibration pattern is used, making it more practical for automotive applications.

  • A GaAs SOI HEMT Fabricated by Fluidic Self-Assembly and Its Application to an RF-Switch

    Koichi MAEZAWA  Ikuo SOGA  Shigeru KISHIMOTO  Takashi MIZUTANI  Kazuhiro AKAMATSU  

     
    PAPER-Novel Integration Technology

      Vol:
    E91-C No:7
      Page(s):
    1025-1030

    The heterogeneous integration of GaAs HEMTs on a polyimide-covered AlN ceramic substrate was demonstrated using a fluidic self-assembly (FSA) technique. We used thin device blocks for the FSA, which have various advantages. In particular, they can reduce the drain-source capacitance Cds of the assembled HEMTs if the substrate has a low dielectric constant. This is a novel kind of semiconductor-on-insulator (SOI) technology. The dc and RF properties of the GaAs HEMTs on the polyimide/AlN substrate were studied and the reduction of Cds was confirmed. This technique was successfully applied to the SPDT switch, where a low Cds is essential for good isolation.

  • Midpoint-Validation Method for Support Vector Machine Classification

    Hiroki TAMURA  Koichi TANNO  

     
    LETTER-Biocybernetics, Neurocomputing

      Vol:
    E91-D No:7
      Page(s):
    2095-2098

    In this paper, we propose a midpoint-validation method which improves the generalization of Support Vector Machine. The proposed method creates midpoint data, as well as a turning adjustment parameter of Support Vector Machine using midpoint data and previous training data. We compare its performance with the original Support Vector Machine, Multilayer Perceptron, Radial Basis Function Neural Network and also tested our proposed method on several benchmark problems. The results obtained from the simulation shows the effectiveness of the proposed method.

  • Development of Mentalizing and Communication: From Viewpoint of Developmental Cybernetics and Developmental Cognitive Neuroscience Open Access

    Shoji ITAKURA  

     
    INVITED PAPER

      Vol:
    E91-B No:7
      Page(s):
    2109-2117

    The ability to mentalize is essential for human socialization. Such ability is strongly related to communication. In this paper, I discuss the development of mentalizing and communication from the perspectives of a new idea, Developmental Cybernetics, and developmental cognitive neuroscience. Children only attributed intention to a robot when they saw it behaving as a human and displaying social signals such as eye gaze. The emergence of powerful new methods and tools, such as neuroimaging, now allows questions about mentalizing to resolved more directly than before.

  • Color Constancy Based on Effective Regions

    Rui LU  De XU  Xinbin YANG  Bing LI  

     
    LETTER-Image Recognition, Computer Vision

      Vol:
    E91-D No:7
      Page(s):
    2091-2094

    None of the existing color constancy algorithms can be considered universal. Furthermore, they use all the image pixels, although actually not all of the pixels are effective in illumination estimation. Consequently, how to select a proper color constancy algorithm from existing algorithms and how to select effective(or useful) pixels from an image are two most important problems for natural images color constancy. In this paper, a novel Color Constancy method using Effective Regions (CCER) is proposed, which consists of the proper algorithm selection and effective regions selection. For a given image, the most proper algorithm is selected according to its Weilbull distribution while its effective regions are chosen based on image similarity. The experiments show promising results compared with the state-of-the-art methods.

  • AlN/GaN Metal Insulator Semiconductor Field Effect Transistor on Sapphire Substrate

    Sanghyun SEO  Kaustav GHOSE  Guang Yuan ZHAO  Dimitris PAVLIDIS  

     
    PAPER-Nitride-based Devices

      Vol:
    E91-C No:7
      Page(s):
    994-1000

    AlN/GaN Metal Insulator Semiconductor Field Effect Transistors (MISFETs) were designed, simulated and fabricated. DC, S-parameter and power measurements were also performed. Drift-diffusion simulations using DESSIS compared AlN/GaN MISFETs and Al32Ga68N/GaN Heterostructure FETs (HFETs) with the same geometries. The simulation results show the advantages of AlN/GaN MISFETs in terms of higher saturation current, lower gate leakage and higher transconductance than AlGaN/GaN HFETs. First results from fabricated AlN/GaN devices with 1 µm gate length and 200 µm gate width showed a maximum drain current density of 380 mA/mm and a peak extrinsic transconductance of 85 mS/mm. S-parameter measurements showed that current-gain cutoff frequency (fT) and maximum oscillation frequency (fmax) were 5.85 GHz and 10.57 GHz, respectively. Power characteristics were measured at 2 GHz and showed output power density of 850 mW/mm with 23.8% PAE at VDS = 15 V. To the authors knowledge this is the first report of a systematic study of AlN/GaN MISFETs addressing their physical modeling and experimental high-frequency characteristics including the power performance.

  • Adaptively Combining Local with Global Information for Natural Scenes Categorization

    Shuoyan LIU  De XU  Xu YANG  

     
    LETTER-Image Recognition, Computer Vision

      Vol:
    E91-D No:7
      Page(s):
    2087-2090

    This paper proposes the Extended Bag-of-Visterms (EBOV) to represent semantic scenes. In previous methods, most representations are bag-of-visterms (BOV), where visterms referred to the quantized local texture information. Our new representation is built by introducing global texture information to extend standard bag-of-visterms. In particular we apply the adaptive weight to fuse the local and global information together in order to provide a better visterm representation. Given these representations, scene classification can be performed by pLSA (probabilistic Latent Semantic Analysis) model. The experiment results show that the appropriate use of global information improves the performance of scene classification, as compared with BOV representation that only takes the local information into account.

  • 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.

  • The Optimal H Norm of a Parametric System Achievable by an Output Feedback Controller

    Takuya KITAMOTO  Tetsu YAMAGUCHI  

     
    PAPER-Systems and Control

      Vol:
    E91-A No:7
      Page(s):
    1713-1724

    H∞ optimal control is one of the most successful achievements in the post modern control theory. In the H∞ optimal control, we design a controller that minimizes the H∞ norm of a given system. Although the algorithms to solve the problem have already been reported, they focus on numerical systems (systems without any unknown parameters) and, can not be applied for parametric systems (systems with unknown parameters). Given a parametric system, this paper presents an algorithm to compute the optimal H∞ norm of the system achieved by an output feedback controller. The optimal H∞ norm is expressed as , where φ(k) denotes a root of a bivariate polynomial. A numerical example is given to show the effectiveness of the algorithm.

  • NoC-Compatible Wrapper Design and Optimization under Channel-Bandwidth and Test-Time Constraints

    Fawnizu Azmadi HUSSIN  Tomokazu YONEDA  Hideo FUJIWARA  

     
    PAPER-Dependable Computing

      Vol:
    E91-D No:7
      Page(s):
    2008-2017

    The IEEE 1500 standard wrapper requires that its inputs and outputs be interfaced directly to the chip's primary inputs and outputs for controllability and observability. This is typically achieved by providing a dedicated Test Access Mechanism (TAM) between the wrapper and the primary inputs and outputs. However, when reusing the embedded Network-on-Chip (NoC) interconnect instead of the dedicated TAM, the standard wrapper cannot be used as is because of the packet-based transfer mechanism and other functional requirements by the NoC. In this paper, we describe two NoC-compatible wrappers, which overcome these limitations of the 1500 wrapper. The wrappers (Type 1 and Type 2) complement each other to optimize NoC bandwidth utilization while minimizing the area overhead. The Type 2 wrapper uses larger area overhead to increase bandwidth efficiency, while Type 1 takes advantage of some special configurations which may not require a complex and high-cost wrapper. Two wrapper optimization algorithms are applied to both wrapper designs under channel-bandwidth and test-time constraints, resulting in very little or no increase in the test application time compared to conventional dedicated TAM approaches.

  • 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.

  • Channel Estimation Based on Adaptive Neuro-Fuzzy Inference System in OFDM

    M. Nuri SEYMAN   Necmi TAPINAR  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E91-B No:7
      Page(s):
    2426-2430

    In this letter we purpose adaptive neuro-fuzzy inference system (ANFIS) for channel estimation in orthogonal frequency division multiplexing (OFDM) systems. To evaluate the performance of this estimator, we compare the ANFIS with least square (LS) algorithm, minimum mean square error (MMSE) algorithm by using bit error rate (BER) and mean square error (MSE) criterias. According to computer simulations the performance of ANFIS has better performance than LS algorithm and close to MMSE algorithm. Besides there is unnecessity to send pilot when used the ANFIS.

  • 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.

  • Introducing a Translation Dictionary into Phrase-Based SMT

    Hideo OKUMA  Hirofumi YAMAMOTO  Eiichiro SUMITA  

     
    PAPER-Natural Language Processing

      Vol:
    E91-D No:7
      Page(s):
    2051-2057

    This paper presents a method to effectively introduce a translation dictionary into phrase-based SMT. Though SMT systems can be built with only a parallel corpus, translation dictionaries are more widely available and have many more entries than parallel corpora. A simple and low-cost method to introduce a translation dictionary is to attach a dictionary entry into a phrase table. This, however, does not work well. Target word order and even whole target sentences are often incorrect. To solve this problem, the proposed method uses high-frequency words in the training corpus. The high-frequency words may already be trained well; in other words, they may appear in the phrase table and therefore be translated with correct word order. Experimental results show the proposed method as far superior to simply attaching dictionary entries into phrase tables.

  • Reversible Watermark with Large Capacity Based on the Prediction Error Expansion

    Minoru KURIBAYASHI  Masakatu MORII  Hatsukazu TANAKA  

     
    PAPER-Cryptography and Information Security

      Vol:
    E91-A No:7
      Page(s):
    1780-1790

    A reversible watermark algorithm with large capacity has been developed by applying the difference expansion of a generalized integer transform. In this algorithm, a watermark signal is inserted in the LSB of the difference values among pixels. In this paper, we apply the prediction errors calculated by a predictor in JPEG-LS for embedding watermark, which contributes to increase the amount of embedded information with less degradation. As one of the drawbacks discovered in the above conventional method is the large size of the embedded location map introduced to make it reversible, we decrease the large size of the location map by vectorization, and then modify the composition of the map using the local characteristics. We also exclude the positions such that the modification in the embedding operation cannot increase the capacity but merely degrade the image quality, which can be applicable to the conventional methods.

  • Design of a High-Precision DDS-Based Configurable Clock Generator

    Hsin-Chuan CHEN  

     
    PAPER-Integrated Electronics

      Vol:
    E91-C No:7
      Page(s):
    1151-1157

    Configurable clock is necessary for many applications such as digital communication systems, however, using the conventional direct digital frequency synthesizer (DDS) as a pulse or clock generator may cause jitter problems. People usually employ phase-interpolation approaches to generate a pulse or clock with correct time intervals. This work proposes a new phase-interpolation DDS scheme, which uses the output of the phase accumulator to provide an initial voltage on an integration capacitor by pre-charging in the first phase, and then performs integration operation on the same integration capacitor in the second phase. By using single capacitor integration, the instability of the delay generator existed in the phase-interpolation DDS can be avoided, and the impact caused by capacitance error in the circuit implementation also can be reduced. Furthermore, without ROM tables, the proposed DDS using pre-charging integration not only reduces the spurious level of the clock output, but also has a low hardware complexity.

  • 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.

9101-9120hit(18690hit)