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

Keyword Search Result

[Keyword] shape(193hit)

21-40hit(193hit)

  • Compact LTE/WWAN Antenna with Reduced Ground Effects for Tablet/Laptop Applications

    Chow-Yen-Desmond SIM  Chih-Chiang CHEN  Che-Yu LI  Sheng-Yang HUANG  

     
    PAPER-Antennas

      Pubricized:
    2017/08/22
      Vol:
    E101-B No:2
      Page(s):
    324-331

    A compact uniplanar antenna design for tablet/laptop applications is proposed. The main design principle of this antenna is the use of the coupling-feed mechanism. The proposed antenna is composed of an inverted L-shaped parasitic element, T-shaped feeding strip, parasitic shorted strip, and a step tuning stub. With its small size of 55mm × 15mm × 0.8mm, the proposed antenna is able to excite dual wideband transmission over the full LTE/WWAN operation ranges of 698-960MHz and 1710-2690MHz. Furthermore, the proposed antenna also exhibits reduced ground effects, such that reducing the ground size of the proposed antenna will not affect its performance.

  • Automatic Optic Disc Boundary Extraction Based on Saliency Object Detection and Modified Local Intensity Clustering Model in Retinal Images

    Wei ZHOU  Chengdong WU  Yuan GAO  Xiaosheng YU  

     
    LETTER-Image

      Vol:
    E100-A No:9
      Page(s):
    2069-2072

    Accurate optic disc localization and segmentation are two main steps when designing automated screening systems for diabetic retinopathy. In this paper, a novel optic disc detection approach based on saliency object detection and modified local intensity clustering model is proposed. It consists of two stages: in the first stage, the saliency detection technique is introduced to the enhanced retinal image with the aim of locating the optic disc. In the second stage, the optic disc boundary is extracted by the modified Local Intensity Clustering (LIC) model with oval-shaped constrain. The performance of our proposed approach is tested on the public DIARETDB1 database. Compared to the state-of-the-art approaches, the experimental results show the advantages and effectiveness of the proposed approach.

  • Utilizing Shape-Based Feature and Discriminative Learning for Building Detection

    Shangqi ZHANG  Haihong SHEN  Chunlei HUO  

     
    LETTER-Image Recognition, Computer Vision

      Pubricized:
    2016/11/18
      Vol:
    E100-D No:2
      Page(s):
    392-395

    Building detection from high resolution remote sensing images is challenging due to the high intraclass variability and the difficulty in describing buildings. To address the above difficulties, a novel approach is proposed based on the combination of shape-specific feature extraction and discriminative feature classification. Shape-specific feature can capture complex shapes and structures of buildings. Discriminative feature classification is effective in reflecting similarities among buildings and differences between buildings and backgrounds. Experiments demonstrate the effectiveness of the proposed approach.

  • Simultaneous Optimal Design Method of Primary Radiator and Main Reflector for Shaped Beam Antennas

    Takashi TOMURA  Michio TAKIKAWA  Yoshio INASAWA  Hiroaki MIYASHITA  

     
    PAPER

      Vol:
    E100-B No:2
      Page(s):
    211-218

    Shaped beam reflector antennas are widely used because they can achieve a shaped beam even with a single primary feed. Because coverage shapes depend on service areas, optimum primary radiators and reflector shapes are determined by the service areas. In this paper, we propose a simultaneous optimal design method of the primary radiator and reflector for the shaped beam antenna. Particle swarm optimization and the conjugate gradient method are adopted to optimize the primary radiator and reflector. The design method is applied to Japan coverage to verify its effectiveness.

  • Micro-Vibration Patterns Generated from Shape Memory Alloy Actuators and the Detection of an Asymptomatic Tactile Sensation Decrease in Diabetic Patients

    Junichi DANJO  Sonoko DANJO  Yu NAKAMURA  Keiji UCHIDA  Hideyuki SAWADA  

     
    PAPER-Human-computer Interaction

      Pubricized:
    2016/08/10
      Vol:
    E99-D No:11
      Page(s):
    2759-2766

    Diabetes mellitus is a group of metabolic diseases that cause high blood sugar due to functional problems with the pancreas or metabolism. Diabetic patients have few subjective symptoms and may experience decreased sensation without being aware of it. The commonly performed tests for sensory disorders are qualitative in nature. The authors pay attention to the decline of the sensitivity of tactile sensations, and develop a non-invasive method to detect the level of tactile sensation using a novel micro-vibration actuator that employs shape-memory alloy wires. Previously, we performed a pilot study that applied the device to 15 diabetic patients and confirmed a significant reduction in the tactile sensation in diabetic patients when compared to healthy subjects. In this study, we focus on the asymptomatic development of decreased sensation associated with diabetes mellitus. The objectives are to examine diabetic patients who are unaware of abnormal or decreased sensation using the quantitative tactile sensation measurement device and to determine whether tactile sensation is decreased in patients compared to healthy controls. The finger method is used to measure the Tactile Sensation Threshold (TST) score of the index and middle fingers using the new device and the following three procedures: TST-1, TST-4, and TST-8. TST scores ranged from 1 to 30 were compared between the two groups. The TST scores were significantly higher for the diabetic patients (P<0.05). The TST scores for the left fingers of diabetic patients and healthy controls were 5.9±6.2 and 2.7±2.9 for TST-1, 15.3±7.0 and 8.7±6.4 for TST-4, and 19.3±7.8 and 12.7±9.1 for TST-8. Our data suggest that the use of the new quantitative tactile sensation measurement device enables the detection of decreased tactile sensation in diabetic patients who are unaware of abnormal or decreased sensation compared to controls.

  • A Broadband Circularly Polarized Waveguide Antenna Design for Low Cross-Polarization

    Ryoji YAMAUCHI  Takeshi FUKUSAKO  

     
    PAPER-Antennas and Propagation

      Pubricized:
    2016/04/19
      Vol:
    E99-B No:10
      Page(s):
    2187-2194

    An L-shaped probe with a surrounding aperture such as a waveguide can generate circular polarization (CP) waves. Circular waveguide antennas using an L-shaped probe have broadband characteristics both in axial ratio (AR) and in input impedance, however cross-polarization (XPOL) is easily generated due to its asymmetrical structure resulting in a radiation pattern that has narrow CP azimuth range. In this paper, design techniques to reduce the XPOL generated from a circular waveguide antenna using an L-shaped probe are proposed. As a result, XPOL is reduced by around 10 dB, and CP is radiated over a wide angle range of 120-150° covering frequencies from 7.35 to 9.75GHz.

  • Energy Distribution of Periodically Dielectric Waveguides by Arbitrary Shape of Dielectric Constants — The Influence of Dielectric Structures in the Middle Layer —

    Ryosuke OZAKI  Tsuneki YAMASAKI  

     
    BRIEF PAPER

      Vol:
    E99-C No:7
      Page(s):
    820-824

    In this paper, we have investigated a new structure which combines dielectric cylinders with air-hole cylinders array, and analyzed the guiding problem for periodically dielectric waveguides by arbitrary shape of dielectric constants in the middle layer. In the numerical analysis, we examined an influence of the dielectric circular cylinder along a middle layer by using the energy distribution and complex propagation constants at the first stop band region compared with hollow dielectric cylinder. In addition, we also investigated the influence of dielectric structure with equivalence cross section compared with dielectric cylinders, and clarified an influence of dielectric structures in the middle layer by energy distribution analysis for TE0 mode.

  • Automatic Recognition of Mycobacterium Tuberculosis Based on Active Shape Model

    Chao XU  Dongxiang ZHOU  Tao GUAN  Yongping ZHAI  Yunhui LIU  

     
    PAPER-Pattern Recognition

      Pubricized:
    2016/01/08
      Vol:
    E99-D No:4
      Page(s):
    1162-1171

    This paper realized the automatic recognition of Mycobacterium tuberculosis in Ziehl-Neelsen stained images by the conventional light microscopy, which can be used in the computer-aided diagnosis of the tuberculosis. We proposed a novel recognition method based on active shape model. First, the candidate bacillus objects are segmented by a method of marker-based watershed transform. Next, a point distribution model of the object shape is proposed to label the landmarks on the object automatically. Then the active shape model is performed after aligning the training set with a weight matrix. The deformation regulation of the object shape is discovered and successfully applied in recognition without using geometric and other commonly used features. During this process, a width consistency constraint is combined with the shape parameter to improve the accuracy of the recognition. Experimental results demonstrate that the proposed method yields high accuracy in the images with different background colors. The recognition accuracy in object level and image level are 92.37% and 97.91% respectively.

  • Robust Face Alignment with Random Forest: Analysis of Initialization, Landmarks Regression, and Shape Regularization Methods

    Chun Fui LIEW  Takehisa YAIRI  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2015/10/27
      Vol:
    E99-D No:2
      Page(s):
    496-504

    Random forest regressor has recently been proposed as a local landmark estimator in the face alignment problem. It has been shown that random forest regressor can achieve accurate, fast, and robust performance when coupled with a global face-shape regularizer. In this paper, we extend this approach and propose a new Local Forest Classification and Regression (LFCR) framework in order to handle face images with large yaw angles. Specifically, the LFCR has an additional classification step prior to the regression step. Our experiment results show that this additional classification step is useful in rejecting outliers prior to the regression step, thus improving the face alignment results. We also analyze each system component through detailed experiments. In addition to the selection of feature descriptors and several important tuning parameters of the random forest regressor, we examine different initialization and shape regularization processes. We compare our best outcomes to the state-of-the-art system and show that our method outperforms other parametric shape-fitting approaches.

  • False Image Suppression in Two-Dimensional Shape Estimates of a Walking Human Using Multiple Ultra-Wideband Doppler Radar Interferometers

    Hiroki YAMAZAKI  Takuya SAKAMOTO  Hirofumi TAKI  Toru SATO  

     
    PAPER-Sensing

      Vol:
    E99-B No:1
      Page(s):
    134-142

    Microwave systems have a number of promising applications in surveillance and monitoring systems. The main advantage of microwave systems is their ability to detect targets at distance under adverse conditions such as dim, smoky, and humid environments. Specifically, the wide bandwidth of ultra-wideband radar enables high range resolution. In a previous study, we proposed an accurate shape estimation algorithm for multiple targets using multiple ultra-wideband Doppler interferometers. However, this algorithm produces false image artifacts under conditions with severe interference. The present paper proposes a technique to suppress such false images by detecting inconsistent combinations of the radial velocity and time derivative of image positions. We study the performance of the proposed method through numerical simulations of a two-dimensional section of a moving human body, and demonstrate the remarkable performance of the proposed method in suppressing false image artifacts in many scenarios.

  • Node Symbol Timing Error Estimator for Physical-Layer Network-Coded Relay

    Xiaoyu DANG  Qiang LI  Hao XIAO  Cheng WAN  

     
    LETTER-Communication Theory and Signals

      Vol:
    E98-A No:12
      Page(s):
    2733-2737

    Network coding on the physical-layer has recently been widely discussed as a potentially promising solution to the wireless access problem in a relay network. However, the existing research on physical-layer network coding (PNC), usually assumes that the symbol timing of the nodes is fully synchronized and hardly investigates the unavoidable symbol timing errors. Similar to many telecommunication systems, symbol timing plays a critical role in PNC and precise alignment has to be provided for the encoding. In this work, we propose a novel symbol timing algorithm with a low oversampling factor (samples per symbol) based on the a priori knowledge of the transmitted pulse shape. The proposed algorithm has the dual advantages of the low oversampling rate and high precision. The mean square error (MSE) performance is verified by simulations to be at least one order of magnitude better than that of the conventional optimum phase (OP) algorithm for a signal noise ratio (SNR) greater than 5dB.

  • Robust Moving Object Extraction and Tracking Method Based on Matching Position Constraints

    Tetsuya OKUDA  Yoichi TOMIOKA  Hitoshi KITAZAWA  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2015/04/28
      Vol:
    E98-D No:8
      Page(s):
    1571-1579

    Object extraction and tracking in a video image is basic technology for many applications, such as video surveillance and robot vision. Many moving object extraction and tracking methods have been proposed. However, they fail when the scenes include illumination change or light reflection. For tracking the moving object robustly, we should consider not only the RGB values of input images but also the shape information of the objects. If the objects' shapes do not change suddenly, matching positions on the cost matrix of exclusive block matching are located nearly on a line. We propose a method for obtaining the correspondence of feature points by imposing a matching position constraint induced by the shape constancy. We demonstrate experimentally that the proposed method achieves robust tracking in various environments.

  • Response of a Superconducting Transition-Edge Sensor Microcalorimeter with a Mushroom-shaped Absorber to L X-rays Emitted by Transuranium Elements Open Access

    Keisuke MAEHATA  Makoto MAEDA  Naoko IYOMOTO  Kenji ISHIBASHI  Keisuke NAKAMURA  Katsunori AOKI  Koji TAKASAKI  Kazuhisa MITSUDA  Keiichi TANAKA  

     
    INVITED PAPER

      Vol:
    E98-C No:3
      Page(s):
    178-185

    A four-pixel-array superconducting transition-edge sensor (TES) microcalorimeter with a mushroom-shaped absorber was fabricated for the energy dispersive spectroscopy performed on a transmission electron microscope. The TES consists of a bilayer of Au/Ti with either a 50-nm or 120-nm thickness. The absorber of 5.0,$mu$m thick is made from a Au layer and its stem is deposited in the center of the TES surface. A Ta$_{2}$O$_{5}$ insulating layer of 100-nm thickness is inserted between the overhang region of the absorber and the TES surface. A selected pixel of the TES microcalorimeter was operated for the detection of Np L X-rays emitted from an $^{241}$Am source. A response of the TES microcalorimeter to L X-rays was obtained by analyzing detection signal pulses with using the optimal filter method. An energy resolution was obtained to be 33,eV of the full width at half maximum value at 17.751,keV of Np L$_{eta 1}$ considering its natural width of 13.4,eV. Response to L X-rays emitted from a mixture source of $^{238}$Pu, $^{239}$Pu and $^{241}$Am was obtained by operating the selected pixel of the TES microcalorimeter. Major L X-ray peaks of progeny elements of $alpha$ decay of Pu and Am isotopes were clearly identified in the obtained energy spectrum. The experimental results demonstrated the separation of $^{241}$Am and plutonium isotopes by L X-ray spectroscopy.

  • Local Information, Observable Parameters, and Global View Open Access

    Hiroshi SAITO  

     
    INVITED PAPER

      Vol:
    E96-B No:12
      Page(s):
    3017-3027

    The “Blind Men and an Elephant” is an old Indian story about a group of blind men who encounter an elephant and do not know what it is. This story describes the difficulties of understanding a large concept or global view based on only local information. Modern technologies enable us to easily obtain and retain local information. However, simply collecting local information does not give us a global view, as evident in this old story. This paper gives a concrete model of this story on the plane to theoretically and mathematically discuss it. It analyzes what information we can obtain from collected local information. For a convex target object modeling the elephant and a convex sensing area, it is proven that the size and perimeter length of the target object are the only parameters that can be observed by randomly deployed sensors modeling the blind men. To increase the number of observable parameters, this paper argues that non-convex sensing areas are important and introduces composite sensor nodes as an approach to implement non-convex sensing areas. The paper also derives a model on the discrete space and analyzes it. The analysis results on the discrete space are applicable to some network related issues such as link quality estimation in a part of a network based on end-to-end probing.

  • M-Shaped Dielectric Phase Shifter for Beam-Steerable Base-Station Antenna

    Kengo NISHIMOTO  Takeshi OSHIMA  Toru FUKASAWA  Hiroaki MIYASHITA  Yoshihiko KONISHI  Manabu KURIHARA  Yoshiyuki CHATANI  

     
    PAPER-Antennas and Propagation

      Vol:
    E96-B No:8
      Page(s):
    2095-2101

    We propose a simple and small phase shifter for a beam-steerable base-station antenna. This phase shifter has no metallic heterojunction, and the phase shift is controlled by moving an M-shaped dielectric plate between the strip conductor and the ground plane of a strip line. We derive a design equation from the condition that at the center frequency f0, the reflection coefficient = 0. In this phase shifter, the reflection coefficient becomes minimum at f0 regardless of the movement distance, r, of the dielectric plate, and the relationship between the phase shift and r is linear. These characteristics are verified by performing simulations and measurements. The size of the M-shaped dielectric phase shifter is 0.27λ00.12λ0, where λ0 is the free-space wavelength at f0. The insertion loss is smaller than about 0.2 dB within a fractional bandwidth of 10%, and the phase shift can vary from 0 to about 80 degrees.

  • Novel Tunneling Field-Effect Transistor with Sigma-Shape Embedded SiGe Sources and Recessed Channel

    Min-Chul SUN  Sang Wan KIM  Garam KIM  Hyun Woo KIM  Hyungjin KIM  Byung-Gook PARK  

     
    PAPER

      Vol:
    E96-C No:5
      Page(s):
    639-643

    A novel tunneling field-effect transistor (TFET) featuring the sigma-shape embedded SiGe sources and recessed channel is proposed. The gate facing the source effectively focuses the E-field at the tip of the source and eliminates the gradual turn-on issue of planar TFETs. The fabrication scheme modified from the state-of-the-art 45 nm/32 nm CMOS technology flows provides a unique benefit in the co-integrability and the control of ID-VGS characteristics. The feasibility is verified with TCAD process simulation of the device with 14 nm of the gate dimension. The device simulation shows 5-order change in the drain current with a gate bias change less than 300 mV.

  • L-Shaped Tunneling Field-Effect Transistors for Complementary Logic Applications

    Sang Wan KIM  Woo Young CHOI  Min-Chul SUN  Hyun Woo KIM  Jong-Ho LEE  Hyungcheol SHIN  Byung-Gook PARK  

     
    PAPER

      Vol:
    E96-C No:5
      Page(s):
    634-638

    In order to implement complementary logic function with L-shaped tunneling field-effect transistors (TFETs), current drivability and subthreshold swing (SS) need to be improved more. For this purpose, high-k material such as hafnium dioxide (HfO2) has been used as gate dielectric rather than silicon dioxide (SiO2). The effects of device parameters on performance have been investigated and the design of L-shaped TFETs has been optimized. Finally, the performance of L-shaped TFET inverters have been compared with that of conventional TFET ones.

  • A Survey on Statistical Modeling and Machine Learning Approaches to Computer Assisted Medical Intervention: Intraoperative Anatomy Modeling and Optimization of Interventional Procedures Open Access

    Ken'ichi MOROOKA  Masahiko NAKAMOTO  Yoshinobu SATO  

     
    SURVEY PAPER-Computer Assisted Medical Intervention

      Vol:
    E96-D No:4
      Page(s):
    784-797

    This paper reviews methods for computer assisted medical intervention using statistical models and machine learning technologies, which would be particularly useful for representing prior information of anatomical shape, motion, and deformation to extrapolate intraoperative sparse data as well as surgeons' expertise and pathology to optimize interventions. Firstly, we present a review of methods for recovery of static anatomical structures by only using intraoperative data without any preoperative patient-specific information. Then, methods for recovery of intraoperative motion and deformation are reviewed by combining intraoperative sparse data with preoperative patient-specific stationary data, which is followed by a survey of articles which incorporated biomechanics. Furthermore, the articles are reviewed which addressed the used of statistical models for optimization of interventions. Finally, we conclude the survey by describing the future perspective.

  • Model-Based Approach to Recognize the Rectus Abdominis Muscle in CT Images Open Access

    Naoki KAMIYA  Xiangrong ZHOU  Huayue CHEN  Chisako MURAMATSU  Takeshi HARA  Hiroshi FUJITA  

     
    LETTER-Medical Image Processing

      Vol:
    E96-D No:4
      Page(s):
    869-871

    Our purpose in this study is to develop a scheme to segment the rectus abdominis muscle region in X-ray CT images. We propose a new muscle recognition method based on the shape model. In this method, three steps are included in the segmentation process. The first is to generate a shape model for representing the rectus abdominis muscle. The second is to recognize anatomical feature points corresponding to the origin and insertion of the muscle, and the third is to segment the rectus abdominis muscles using the shape model. We generated the shape model from 20 CT cases and tested the model to recognize the muscle in 10 other CT cases. The average value of the Jaccard similarity coefficient (JSC) between the manually and automatically segmented regions was 0.843. The results suggest the validity of the model-based segmentation for the rectus abdominis muscle.

  • Asymmetry in Facial Expressions as a Function of Social Skills

    Masashi KOMORI  Hiroko KAMIDE  Satoru KAWAMURA  Chika NAGAOKA  

     
    PAPER-Face Perception and Recognition

      Vol:
    E96-D No:3
      Page(s):
    507-513

    This study investigated the relationship between social skills and facial asymmetry in facial expressions. Three-dimensional facial landmark data of facial expressions (neutral, happy, and angry) were obtained from Japanese participants (n = 62). Following a facial expression task, each participant completed KiSS-18 (Kikuchi's Scale of Social Skills; Kikuchi, 2007). Using a generalized Procrustes analysis, faces and their mirror-reversed versions were represented as points on a hyperplane. The asymmetry of each individual face was defined as Euclidian distance between the face and its mirror reversed face on this plane. Subtraction of the asymmetry level of a neutral face of each individual from the asymmetry level of a target emotion face was defined as the index of “expression asymmetry” given by a particular emotion. Correlation coefficients of KiSS-18 scores and expression asymmetry scores were computed for both happy and angry expressions. Significant negative correlations between KiSS-18 scores and expression asymmetries were found for both expressions. Results indicate that the symmetry in facial expressions increases with higher level of social skills.

21-40hit(193hit)