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[Keyword] PA(8249hit)

1701-1720hit(8249hit)

  • Reflection and Transmission Characteristics of Laminated Structures Consisting a Dipole Array Sheet and a Wire Grid and Dielectric Layer

    Shinichiro YAMAMOTO  Kenichi HATAKEYAMA  Takanori TSUTAOKA  

     
    PAPER

      Vol:
    E98-B No:7
      Page(s):
    1235-1241

    This paper proposes reflection and transmission control panels using artificially designed materials. As the artificially designed material, finite- and infinite-length metal wire array sheets are used here. Laminated structures consisting of the metal wire array sheets and dielectric material are proposed. Reflection and transmission characteristics of these structures can be controlled by changing the metal wire parameters such as wire length, spacing gaps between the wires, and the dielectric material's thickness and relative permittivity. The reflection and transmission characteristics of the laminated structures are evaluated by measurements in free space and by transmission line theory.

  • Centralized Inter-Cell Interference Coordination Using Multi-Band 3D Beam-Switching in Cellular Networks

    Hiroyuki SEKI  Fumiyuki ADACHI  

     
    PAPER-Terrestrial Wireless Communication/Broadcasting Technologies

      Vol:
    E98-B No:7
      Page(s):
    1363-1372

    The deployment of small cells is one of the most effective means to cope with the traffic explosion of cellular mobile systems. However, a small cell system increases the inter-cell interference, which limits the capacity and degrades the cell-edge user throughput. Inter-cell interference coordination (ICIC), such as fractional frequency reuse (FFR), is a well-known scheme that autonomously mitigates inter-cell interference. In the Long Term Evolution (LTE)-Advanced, the three-dimensional (3D) beamforming, which combines conventional horizontal beamforming and vertical beamforming, has been gaining increasing attention. This paper proposes a novel centralized ICIC scheme that controls the direction of narrow 3D beam for each frequency band of each base station. The centralized controller collects information from the base stations and calculates sub-optimum combinations of narrow beams so as to maximize the proportional fair (PF) utility of all users. This paper describes the throughput of the new centralized ICIC scheme as evaluated by computer simulations and shows it has a significant gain in both average user throughput and cell-edge user throughput compared with the conventional ICIC scheme. This paper also investigates the feasibility of the scheme by assessing its throughput performance in a realistic deployment scenario.

  • Reconstructing Sequential Patterns without Knowing Image Correspondences

    Saba Batool MIYAN  Jun SATO  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2015/04/13
      Vol:
    E98-D No:7
      Page(s):
    1343-1352

    In this paper, we propose a method for reconstructing 3D sequential patterns from multiple images without knowing exact image correspondences and without calibrating linear camera sensitivity parameters on intensity. The sequential pattern is defined as a series of colored 3D points. We assume that the series of the points are obtained in multiple images, but the correspondence of individual points is not known among multiple images. For reconstructing sequential patterns, we consider a camera projection model which combines geometric and photometric information of objects. Furthermore, we consider camera projections in the frequency space. By considering the multi-view relationship on the new projection model, we show that the 3D sequential patterns can be reconstructed without knowing exact correspondence of individual image points in the sequential patterns; moreover, the recovered 3D patterns do not suffer from changes in linear camera sensitivity parameters. The efficiency of the proposed method is tested using real images.

  • Learning Discriminative Features for Ground-Based Cloud Classification via Mutual Information Maximization

    Shuang LIU  Zhong ZHANG  Baihua XIAO  Xiaozhong CAO  

     
    LETTER-Image Recognition, Computer Vision

      Pubricized:
    2015/03/24
      Vol:
    E98-D No:7
      Page(s):
    1422-1425

    Texture feature descriptors such as local binary patterns (LBP) have proven effective for ground-based cloud classification. Traditionally, these texture feature descriptors are predefined in a handcrafted way. In this paper, we propose a novel method which automatically learns discriminative features from labeled samples for ground-based cloud classification. Our key idea is to learn these features through mutual information maximization which learns a transformation matrix for local difference vectors of LBP. The experimental results show that our learned features greatly improves the performance of ground-based cloud classification when compared to the other state-of-the-art methods.

  • Discriminative Semantic Parts Learning for Object Detection

    Yurui XIE  Qingbo WU  Bing LUO  

     
    LETTER-Image Recognition, Computer Vision

      Pubricized:
    2015/04/15
      Vol:
    E98-D No:7
      Page(s):
    1434-1438

    In this letter, we propose a new semantic parts learning approach to address the object detection problem with only the bounding boxes of object category labels. Our main observation is that even though the appearance and arrangement of object parts might have variations across the instances of different object categories, the constituent parts still maintain geometric consistency. Specifically, we propose a discriminative clustering method with sparse representation refinement to discover the mid-level semantic part set automatically. Then each semantic part detector is learned by the linear SVM in a one-vs-all manner. Finally, we utilize the learned part detectors to score the test image and integrate all the response maps of part detectors to obtain the detection result. The learned class-generic part detectors have the ability to capture the objects across different categories. Experimental results show that the performance of our approach can outperform some recent competing methods.

  • Resonant Power Supply Noise Reduction by STO Capacitors Fabricated on Interposer

    Toru NAKURA  Masahiro KANO  Masamitsu YOSHIZAWA  Atsunori HATTORI  Kunihiro ASADA  

     
    PAPER-Electronic Circuits

      Vol:
    E98-C No:7
      Page(s):
    734-740

    This paper demonstrates the resonant power supply noise reduction effects of STO thin film decoupling capacitors, which are embedded in interposers. The on-interposer STO capacitor consists of SrTiO2 whose dielectric constant is about 20 and is sandwitched by Cu films in an interposer. The on-interposer STO capacitors are directly connected to the LSI PADs so that they provide large decoupling capacitance without package leadframe/bonding wire inductance, resulting in the reduction of the resonant power supply noise. The measured power supply waveforms show significant reduction of the power supply noise, and the Shmoo plots also show the contribution of the STO capacitors to the robust operations of LSIs.

  • Design of q-Parallel LFSR-Based Syndrome Generator

    Seung-Youl KIM  Kyoung-Rok CHO  Je-Hoon LEE  

     
    BRIEF PAPER

      Vol:
    E98-C No:7
      Page(s):
    594-596

    This paper presents a new parallel architecture of syndrome generator for a high-speed BCH (Bose-Chaudhuri-Hocquenghem) decoder. In particular, the proposed parallel syndrome generators are based on LFSR (linear feedback shift register) architecture to achieve high throughput without significant area overhead. From the experimental results, the proposed approach achieves 4.60 Gbps using 0.25-µm standard CMOS technology. This result is much faster than the conventional byte-wise GFM-based counterpart. The high throughputs are due to the well-tuned hardware implementation using unfolding transformation.

  • Design of Microwave Patch Hybrid Couplers with Arbitrary Power Ratio and Impedance Transformation

    Xianshi JING  Sheng SUN  Lei ZHU  

     
    PAPER-Passive Circuits/Components

      Vol:
    E98-C No:7
      Page(s):
    644-650

    A miniaturized patch hybrid coupler with arbitrary power ratio and impedance transformation is proposed and designed by loading a pair of asymmetric cross slots on a squared patch resonator. To obtain the arbitrary power ratio and impedance transformation, the rectangular size of stepped slot ends should be well designed to be asymmetry and thus to obtain the different inductive loadings along two current paths. Theoretically, the equivalent transmission line model is first developed to understand the physical relationship between the patch and traditional branch-line hybrids. The matching/isolation and power ratio conditions are then derived at center frequency. By following a detailed design guideline, a prototype of the hybrid with 1:2 power ratio and 1:1.3 impedance transformation is designed and fabricated at 4.2 GHz. The measured results show a good agreement with simulated results, where the measured -10 dB impedance bandwidth achieves 18% and the bandwidth of 90°±6° phase difference is about 35% in a frequency range from 3.5 GHz to 5 GHz.

  • Development of Wireless Systems for Disaster Recovery Operations Open Access

    Takashi HIROSE  Fusao NUNO  Masashi NAKATSUGAWA  

     
    INVITED PAPER

      Vol:
    E98-C No:7
      Page(s):
    630-635

    This paper presents wireless systems for use in disaster recovery operations. The Great East Japan Earthquake of March 11, 2011 reinforced the importance of communications in, to, and between disaster areas as lifelines. It also revealed that conventional wireless systems used for disaster recovery need to be renovated to cope with technological changes and to provide their services with easier operations. To address this need we have developed new systems, which include a relay wireless system, subscriber wireless systems, business radio systems, and satellite communication systems. They will be chosen and used depending on the situations in disaster areas as well as on the required services.

  • Far-Field Pattern Reconstruction Using an Iterative Hilbert Transform

    Fan FAN  Tapan K. SARKAR  Changwoo PARK  Jinhwan KOH  

     
    PAPER-Antennas and Propagation

      Vol:
    E98-B No:6
      Page(s):
    1032-1039

    A new approach to reconstructing antenna far-field patterns from the missing part of the pattern is presented in this paper. The antenna far-field pattern can be reconstructed by utilizing the iterative Hilbert transform, which is based on the relationship between the real and imaginary part of the Hilbert transform. A moving average filter is used to reduce the errors in the restored signal as well as the computation load. Under the constraint of the causality of the current source in space, we could successfully reconstruct the data. Several examples dealing with line source antennas and antenna arrays are simulated to illustrate the applicability of this approach.

  • Multi-Task Object Tracking with Feature Selection

    Xu CHENG  Nijun LI  Tongchi ZHOU  Zhenyang WU  Lin ZHOU  

     
    LETTER-Image

      Vol:
    E98-A No:6
      Page(s):
    1351-1354

    In this paper, we propose an efficient tracking method that is formulated as a multi-task reverse sparse representation problem. The proposed method learns the representation of all tasks jointly using a customized APG method within several iterations. In order to reduce the computational complexity, the proposed tracking algorithm starts from a feature selection scheme that chooses suitable number of features from the object and background in the dynamic environment. Based on the selected feature, multiple templates are constructed with a few candidates. The candidate that corresponds to the highest similarity to the object templates is considered as the final tracking result. In addition, we present a template update scheme to capture the appearance changes of the object. At the same time, we keep several earlier templates in the positive template set unchanged to alleviate the drifting problem. Both qualitative and quantitative evaluations demonstrate that the proposed tracking algorithm performs favorably against the state-of-the-art methods.

  • A Participating Fine-Grained Cloud Computing Platform with In-Network Guidance

    Kento NISHII  Yosuke TANIGAWA  Hideki TODE  

     
    PAPER-Network

      Vol:
    E98-B No:6
      Page(s):
    1008-1017

    What should be the ultimate form of the cloud computing environment? The solution should have two important features; “Fine-Granularity” and “Participation.” To realize an attractive and feasible solution with these features, we propose a “participating fine-grained cloud computing platform” that a large number of personal or small-company resource suppliers participate in, configure and provide cloud computing on. This enables users to be supplied with smaller units of resources such as computing, memory, content, and applications, in comparison with the traditional Infrastructure as a Service (IaaS). Furthermore, to search for nearby resources efficiently among the many available on the platform, we also propose Resource Breadcrumbs (RBC) as a key technology of our proposed platform to provide in-network guidance capability autonomously for users' queries. RBC allows supplier-nodes to distribute guidance information directed to themselves with dedicated control messages; in addition, the information can be logged along the trail of message from supplier to user. With this distributed information, users can to autonomously locate nearby resources. Distributed management also reduces computational load on the central database and enables a participating fine-grained cloud platform at lower cost.

  • A Forward/Reverse Body Bias Generator with Wide Supply-Range down to Threshold Voltage

    Norihiro KAMAE  Akira TSUCHIYA  Hidetoshi ONODERA  

     
    PAPER

      Vol:
    E98-C No:6
      Page(s):
    504-511

    A forward/reverse body bias generator (BBG) which operates under wide supply-range is proposed. Fine-grained body biasing (FGBB) is effective to reduce variability and increase energy efficiency on digital LSIs. Since FGBB requires a number of BBGs to be implemented, simple design is preferred. We propose a BBG with charge pumps for reverse body bias and the BBG operates under wide supply-range from 0.5,V to 1.2,V. Layout of the BBG was designed in a cell-based flow with an AES core and fabricated in a 65~nm CMOS process. Area of the AES core is 0.22 mm$^2$ and area overhead of the BBG is 2.3%. Demonstration of the AES core shows a successful operation with the supply voltage from 0.5,V to 1.2,V which enables the reduction of power dissipation, for example, of 17% at 400,MHz operation.

  • An Efficient Pattern Matching Algorithm for Ordered Term Tree Patterns

    Yusuke SUZUKI  Takayoshi SHOUDAI  Tomoyuki UCHIDA  Tetsuhiro MIYAHARA  

     
    PAPER

      Vol:
    E98-A No:6
      Page(s):
    1197-1211

    A term tree pattern is a rooted ordered tree pattern which consists of ordered tree structures with edge labels and structured variables with labels. All variables with the same label in a term tree pattern can be simultaneously replaced with ordered trees isomorphic to the same rooted ordered tree. Then, a term tree pattern is suitable for representing structural features common to tree structured data such as XML documents on the web, the secondary structures of RNA in biology and parse trees describing grammatical structures of natural languages. Let $ott$ be the set of all term tree patterns which have one or more variables with the same label. Let $lott$ be the set of all term tree patterns t such that all variables in t have distinct labels. We remark that $lottsubsetneq ott$ holds. In this paper, we consider a problem, called Matching problem for term tree patterns, of deciding whether or not a given rooted ordered tree T is obtained from a given term tree pattern t by replacing variables in t with rooted ordered trees. We show that Matching problem for term tree patterns in $ott$ is NP-complete, by giving a reduction from the string pattern matching problem, which is NP-complete. Next, by giving operations on an interval, which is a set containing all integers between two given integers representing vertex identifiers, we propose an efficient algorithm for solving Matching problem for term tree patterns in $lottsubsetneq ott$. Then, we show that, when an ordered tree having N vertices and a term tree pattern $t in lott$ having n vertices are given, the proposed matching algorithm correctly solves this problem in O(nN) time.

  • Face Recognition Across Poses Using a Single 3D Reference Model

    Gee-Sern HSU  Hsiao-Chia PENG  Ding-Yu LIN  Chyi-Yeu LIN  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2015/02/24
      Vol:
    E98-D No:6
      Page(s):
    1238-1246

    Face recognition across pose is generally tackled by either 2D based or 3D based approaches. The 2D-based often require a training set from which the cross-pose multi-view relationship can be learned and applied for recognition. The 3D based are mostly composed of 3D surface reconstruction of each gallery face, synthesis of 2D images of novel views using the reconstructed model, and match of the synthesized images to the probes. The depth information provides crucial information for arbitrary poses but more methods are yet to be developed. Extended from a latest face reconstruction method using a single 3D reference model and a frontal registered face, this study focuses on using the reconstructed 3D face for recognition. The recognition performance varies with poses, the closer to the front, the better. Several ways to improve the performance are attempted, including different numbers of fiducial points for alignment, multiple reference models considered in the reconstruction phase, and both frontal and profile poses available in the gallery. These attempts make this approach competitive to the state-of-the-art methods.

  • Improving Width-3 Joint Sparse Form to Attain Asymptotically Optimal Complexity on Average Case

    Hiroshi IMAI  Vorapong SUPPAKITPAISARN  

     
    LETTER

      Vol:
    E98-A No:6
      Page(s):
    1216-1222

    In this paper, we improve a width-3 joint sparse form proposed by Okeya, Katoh, and Nogami. After the improvement, the representation can attain an asymtotically optimal complexity found in our previous work. Although claimed as optimal by the authors, the average computation time of multi-scalar multiplication obtained by the representation is 563/1574n+o(n)≈0.3577n+o(n). That number is larger than the optimal complexity 281/786n+o(n)≈0.3575n+o(n) found in our previous work. To optimize the width-3 joint sparse form, we add more cases to the representation. After the addition, we can show that the complexity is updated to 281/786n+o(n)≈0.3575n+o(n), which implies that the modified representation is asymptotically optimal. Compared to our optimal algorithm in the previous work, the modified width-3 joint sparse form uses less dynamic memory, but it consumes more static memory.

  • On the Eternal Vertex Cover Numbers of Generalized Trees

    Hisashi ARAKI  Toshihiro FUJITO  Shota INOUE  

     
    PAPER

      Vol:
    E98-A No:6
      Page(s):
    1153-1160

    Suppose one of the edges is attacked in a graph G, where some number of guards are placed on some of its vertices. If a guard is placed on one of the end-vertices of the attacked edge, she can defend such an attack to protect G by passing over the edge. For each of such attacks, every guard is allowed either to move to a neighboring vertex, or to stay at where she is. The eternal vertex cover number τ∞(G) is the minimum number of guards sufficient to protect G from any length of any sequence of edge attacks. This paper derives the eternal vertex cover number τ∞(G) of such graphs constructed by replacing each edge of a tree by an arbitrary elementary bipartite graph (or by an arbitrary clique), in terms of easily computable graph invariants only, thereby showing that τ∞(G) can be computed in polynomial time for such graphs G.

  • The List Coloring Reconfiguration Problem for Bounded Pathwidth Graphs

    Tatsuhiko HATANAKA  Takehiro ITO  Xiao ZHOU  

     
    PAPER

      Vol:
    E98-A No:6
      Page(s):
    1168-1178

    We study the problem of transforming one list (vertex) coloring of a graph into another list coloring by changing only one vertex color assignment at a time, while at all times maintaining a list coloring, given a list of allowed colors for each vertex. This problem is known to be PSPACE-complete for bipartite planar graphs. In this paper, we first show that the problem remains PSPACE-complete even for bipartite series-parallel graphs, which form a proper subclass of bipartite planar graphs. We note that our reduction indeed shows the PSPACE-completeness for graphs with pathwidth two, and it can be extended for threshold graphs. In contrast, we give a polynomial-time algorithm to solve the problem for graphs with pathwidth one. Thus, this paper gives sharp analyses of the problem with respect to pathwidth.

  • Secrecy Capacity of Wiretap Channels with Additive Colored Gaussian Noise

    Hachiro FUJITA  

     
    PAPER-Information Theory

      Vol:
    E98-A No:6
      Page(s):
    1276-1287

    Wyner has shown in his seminal paper on (discrete memoryless) wiretap channels that if the channel between the sender and an eavesdropper is a degraded version of the channel between the sender and the legitimate receiver, then the sender can reliably and securely transmit a message to the receiver, while the eavesdropper obtains absolutely no information about the message. Later, Leung-Yan-Cheong and Hellman extended Wyner's result to the case where the noise is white Gaussian. In this paper we extend the white Gaussian wiretap channel to the colored Gaussian case and show the finite block length secrecy capacity of colored Gaussian wiretap channels. We also show the asymptotic secrecy capacity of a specific colored Gaussian wiretap channel for which optimal power allocation can be found by a water-filling procedure.

  • Blind Interference Suppression Scheme by Eigenvector Beamspace CMA Adaptive Array with Subcarrier Transmission Power Assignment for Spectrum Superposing

    Kazuki MARUTA  Jun MASHINO  Takatoshi SUGIYAMA  

     
    PAPER-Antennas and Propagation

      Vol:
    E98-B No:6
      Page(s):
    1050-1057

    This paper proposes a novel blind adaptive array scheme with subcarrier transmission power assignment (STPA) for spectrum superposing in cognitive radio networks. The Eigenvector Beamspace Adaptive Array (EBAA) is known to be one of the blind adaptive array algorithms that can suppress inter-system interference without any channel state information (CSI). However, EBAA has difficulty in suppressing interference signals whose Signal to Interference power Ratio (SIR) values at the receiver are around 0dB. With the proposed scheme, the ST intentionally provides a level difference between subcarriers. At the receiver side, the 1st eigenvector of EBAA is applied to the received signals of the subcarrier assigned higher power and the 2nd eigenvector is applied to those assigned lower power. In order to improve interference suppression performance, we incorporate Beamspace Constant Modulus Algorithm (BSCMA) into EBAA (E-BSCMA). Additionally, STPA is effective in reducing the interference experienced by the primary system. Computer simulation results show that the proposed scheme can suppress interference signals received with SIR values of around 0dB while improving operational SIR for the primary system. It can enhance the co-existing region of 2 systems that share a spectrum.

1701-1720hit(8249hit)