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  • Recent Progress in Medical Image Processing-Virtualized Human Body and Computer-Aided Surgery

    Jun-ichiro TORIWAKI  Kensaku MORI  

     
    INVITED SURVEY PAPER

      Vol:
    E82-D No:3
      Page(s):
    611-628

    In this article we present a survey of medical image processing with the stress on applications of image generation and pattern recognition / understanding to computer aided diagnosis (CAD) and surgery (CAS). First, topics and fields of research in medical image processing are summarized. Second the importance of the 3D image processing and the use of virtualized human body (VHB) is pointed out. Thirdly the visualization and the observation methods of the VHB are introduced. In the forth section the virtualized endoscope system is presented from the viewpoint of the observation of the VHB with the moving viewpoints. The fifth topic is the use of VHB with deformation such as the simulation of surgical operation, intra-operative aids and image overlay. In the seventh section several topics on image processing methodologies are introduced including model generation, registration, segmentation, rendering and the use of knowledge processing.

  • Influence of the Shape of Silver Contacts on the Spatial Distribution of Spectral Intensity of a Breaking Arc

    Mitsuru TAKEUCHI  Takayoshi KUBONO  

     
    PAPER

      Vol:
    E82-C No:1
      Page(s):
    41-48

    In a DC 50 V/3.3 A circuit, the spatial distributions of the spectral intensities of breaking arcs near the cathode for silver contacts were measured on the contact surfaces of three different shapes: flat and spherical (1 mm radius and 2 mm radius) and the arc temperature and the metal-vapor quantity were calculated from the spectral intensities. The influence of the contact shape on the arc temperature and the metal-vapor quantity were also examined, as well as the arc tracks on the contact surfaces and the gain and loss of the contacts. Findings show the distributions of spectral intensities are non-symmetrical from the beginning to the extinction of the breaking arc for the flat contact: However, they are symmetrical in the latter half of the breaking in spite of the number of breaking arcs and the shape of contact surface for the spherical contact. The relationship between the area of the arc tracks on the cathode and the shape of contact surface is the same as the relationship between the existent areas of measured spectra and the shape of the contact surface. For the spherical contacts, the arc temperature and the metal-vapor quantity are affected a little by the radius of the curved of contact surface and the number of breaking arcs. However, the longer the arc duration, the higher the metal-vapor quantity is in the latter period of the breaking arc. For the flat contacts, the metal-vapor quantity is lower than those for the spherical contacts. The gain and loss of the contacts are less and the arc duration is shorter for the flat contact than for the spherical contact.

  • New Surface-Wave-Like Mode on CPWs of Infinite Width and Its Role in Explaining the Leakage Cancellation Effect

    Mikio TSUJI  Hiroshi SHIGESAWA  Arthur A. OLINER  

     
    PAPER-Microwave and Millimeter Wave Technology

      Vol:
    E82-C No:1
      Page(s):
    133-140

    The presence of a new surface-wave-like mode on CPWs of infinite width produces a complex transition region at the onset of leakage, involving the unusual simultaneous combination of a coupling region and a spectral gap. An examination of this region leads to a clear physical explanation of why sharp minima occur in the leakage behavior.

  • A Fundamental Study on Effect of Contact Condition for Electromagnetic Noise at Copper-Carbon Electrodes

    Yasuo EBARA  Toshiaki KOIZUMI  Hideaki SONE  Yoshiaki NEMOTO  

     
    PAPER

      Vol:
    E82-C No:1
      Page(s):
    49-54

    The authors observed the correlation between electromagnetic noise and trace of discharge on surface for various surface areas of Cu in opening copper (Cu)-carbon (C) electrodes. In the case of Cu (anode)-C (cathode), the duration of sporadic burst noise generated by discharge becomes longer when Cu surface area is increased, and trace of discharge (melting area) distribute widely on electrodes. Also the forms of the burst noise in the start of arc are classified, and the traces of discharge correspond to each forms. The forms of the burst noise depend on the pattern which the trace of discharge are formed. As these results, the authors showed the correlation between form of burst noise and trace of discharge on electrode surface.

  • A Study of the Approximate Expressions for Constriction Resistance of Multitude Conducting Spots

    Hitoshi NISHIYAMA  Isao MINOWA  

     
    PAPER

      Vol:
    E82-C No:1
      Page(s):
    25-32

    Simple expressions for constriction resistance of multitude conducting spots were analytically formulated by Greenwood. These expressions, however, include some approximations. Nakamura presented that the constriction resistance of one circular spot computed using the BEM is closed to Maxwell's exact value. This relative error is only e=0. 00162 [%]. In this study, the constriction resistances of two, five and ten conducting spots are computed using the boundary element method (BEM), and compared with those obtained using Greenwood's expressions. As the conducting spots move close to each other, the numerical deviations between constriction resistances computed using Greenwood's expressions and the BEM increase. As a result, mutual resistance computed by the BEM is larger than that obtained from Greenwood's expressions. The numerical deviations between the total resistances computed by Greenwood's expressions and that by the BEM are small. Hence, Greenwood's expressions are valid for the total constriction resistance calculation and can be applied to problems where only the total resistance of two contact surfaces, such as a relay and a switch, is required. However, the numerical deviations between the partial resistances computed by Greenwood's expression and that by the BEM are very large. The partial resistance calculations of multitude conducting spots are beyond the applicable range of Greenwood's expression, since Greenwood's expression for constriction resistance of two conducting spots is obtained by assuming that the conducting spots are equal size. In particular, the deviation between resistances of conducting spots, which are close to each other, is very large. In the case of partial resistances which are significant in semiconductor devices, Greenwood's expressions cannot be used with high precision.

  • Efficient Evaluation of Aperture Field Integration Method for Polyhedron Surfaces and Equivalence to Physical Optics

    Suomin CUI  Makoto ANDO  

     
    PAPER-Electromagnetic Theory

      Vol:
    E81-C No:12
      Page(s):
    1948-1955

    The equivalence between Aperture Field Integration Method (AFIM) and Physical Optical (PO) is discussed for polyhedron surfaces in this paper. The necessary conditions for the equivalence are summarized which demand complete equivalent surface currents and complete apertures. The importance of the exact expressions for both incident and reflected fields in constructing equivalent surface currents is emphasized and demonstrated numerically. The fields from reflected components on additional surface which lies on the Geometrical Optics (GO) reflection boundary are evaluated asymptotically. The analytical expression enhances the computational efficiency of the complete AFIM. The equivalent edge currents (EECs) for AFIM (AFIMEECs) are used to extract the mechanism of this equivalence between AFIM and PO.

  • Excitation of Magnetostatic Surface Wave by Coplanar Waveguide Transducers

    Yoshiaki ANDO  Ning GUAN  Ken'ichiro YASHIRO  Sumio OHKAWA  

     
    PAPER-Electromagnetic Theory

      Vol:
    E81-C No:12
      Page(s):
    1942-1947

    Excitation of magnetostatic surface waves by coplanar waveguide transducers is analyzed by using the integral kernel expansion method. The Fourier integral for the current density is derived in terms of an unknown normal component of the magnetic flux density on slot region of a coplanar waveguide. The integral kernel is expanded into a series of Legendre polynomials and then applying Galerkin's method to the unknown field reduces the Fourier integral to a system of linear equations for the unknown coefficients. In this process, we should take into account the edge conditions which show nonreciprocal characteristics depending on frequency. The present method shows excellent agreement with experiments.

  • A Study on Millimeter-Wave Radar Cross Section Characteristics for Road Condition Sensing

    Hiroyuki YAMAGUCHI  Akihiro KAJIWARA  Shogo HAYASHI  

     
    PAPER-Electronic and Radio Applications

      Vol:
    E81-B No:12
      Page(s):
    2559-2566

    In this paper, millimeter-wave radar cross section (RCS) characteristics for rough surface is investigated by means of an approximation method of the magnetic field integral equation and the feasibility of road condition sensing is discussed. The RCS measurement at 94 GHz is carried out in order to verify the numerical result, thereby the numerical results are in good agreement with the measured RCS. The dependence of RCS on the radar incidence angle and surface roughness is investigated where the cross-polarized RCS characteristic is also considered.

  • Electrical Properties of YBa2Cu3Ox Films Grown by Liquid Phase Epitaxy

    Sadahiko MIURA  Kenji HASHIMOTO  Jian-Guo WEN  Katumi SUZUKI  Tadataka MORISHITA  

     
    INVITED PAPER-High-Frequency Properties of Thin Films

      Vol:
    E81-C No:10
      Page(s):
    1549-1556

    YBa2Cu3Ox films were grown on MgO(100) substrates by liquid phase epitaxy. Their structural and electrical properties were examined. From TEM plan-view images, it is found that the film consists of large grains whose misorientation angles are less than 1. Although the DC critical current density values decrease with increasing the film thickness, the critical current density value of 9. 3105 A/cm2 at 77 K is obtained for a 7 µm-thick film. A microstrip resonator at 10. 8 GHz with a YBCO ground plane shows Q0 values of 14200 at 77 K and 23300 at 40 K, which correspond to surface resistance values of 650 and 400 µΩ, respectively. By using a microstrip line resonator with a Ti/Au ground plane, the critical field of the film at 77 K and 10. 8 GHz is estimated to be 30 Oe. The third-order intercept of the resonator with the Ti/Au ground plane is the input power of +43 dBm and the output power of +30 dBm at 77 K.

  • Determining Pose of Curved 3-D Objects Based on 2-D Contour Matching

    Kazuho ITO  Kyoichi TAKEUCHI  Yoshihiko SUZUKI  

     
    PAPER-Image Processing,Computer Graphics and Pattern Recognition

      Vol:
    E81-D No:10
      Page(s):
    1087-1094

    This paper addresses the problem of determining the 3-D pose of a curved rigid object from a single 2-D image. The surface of the object are assumed to be modeled with several patches, each of which be expressed by an implicit polynomial. Moreover, the sensed data are assumed to be the coordinates of those points that are on the image contours. Based on the idea of contour matching, the algorithm proposed computes the parameters defining the pose of the object, and achieves the segmentation of the sensed data and the recognition of the object.

  • Investigation of Dynamic Orientation Process of Nematic Liquid Crystals Triggered by Conformational Change of Surface Monolayer

    Yutaka MAJIMA  Keisuke KATO  Mitsumasa IWAMOTO  Kunihiro ICHIMURA  

     
    PAPER

      Vol:
    E81-C No:7
      Page(s):
    1070-1076

    We developed a measuring system that measures both capacitance and transmittance of a liquid crystal (LC) cell simultaneously. We then studied the dynamic orientation process of nematic LC molecules between two-photochromic command surfaces. The command surfaces consist of a polymer monolayer bearing azobenzene side chains and they are deposited on glass substrate coated with indium-tin-oxide by using the Langmuir-Blodgett technique. The capacitance of LC cells increased and decreased alternately due to orientation transition in LC molecules by irradiating ultraviolet (UV) and visible light, respectively. Similarly, with the alternating irradiation of UV and visible lights, the transmittance of the LC cell changed periodically. Mean tilt angles of LC molecules under irradiation of UV and visible lights were evaluated from the results of capacitance and transmittance. It was found that the transient transmittance response was delayed to the transient capacitance under the UV irradiation. This result corresponds to that the LC molecules in homeotropic mode tend to remain the optical alignment.

  • Evaluation of Arachidic Acid Langmuir-Blodgett Ultrathin Films on Silver Thin Films from Scattered Light Using Surface Plasmon Polariton Excited at the Interfaces

    Yusuke AOKI  Keizo KATO  Kazunari SHINBO  Futao KANEKO  Takashi WAKAMATSU  

     
    PAPER

      Vol:
    E81-C No:7
      Page(s):
    1098-1105

    Attenuated total reflection (ATR) properties and scattered light properties were measured for Ag thin films and arachidic acid (C20) Langmuir-Blodgett (LB) ultrathin films on the Ag thin films to obtain the information about their complex dielectric constants and surface roughness utilizing an excited surface plasmon polariton. The complex dielectric constants for the Ag thin films and the C20 LB films were obtained by fitting the calculated ATR curves to the experimental ones. The surface roughnesses of these films were estimated by the angular distribution of the scattered light assuming the Gaussian function as an autocorrelation function and a linear superposition of roughness spectra. The angular spectra strongly depended on the roughness parameters: the transverse correlation length σ and the surface corrugation depth δ. The experimental angular distributions were explained by some pairs of σ and δ. It was suggested that the surface roughness of the C20 LB films changed with the number of monolayers since the angular spectra varied with the number of the C20 LB monolayers on the Ag films. It is thought that the measurement of the scattered light is useful to evaluate surface roughnesses of LB ultrathin films.

  • 0. 012-cc Miniaturized GaAs P-Pocket Power MESFET Amplifier Operating with a Single Voltage Supply for PHS Applications

    Masami NAGAOKA  Hironori NAGASAWA  Katsue K. KAWAKYU  Kenji HONMYO  Shinji ISHIDA  Yoshiaki KITAURA  Naotaka UCHITOMI  

     
    PAPER-Microwave and Millimeter Wave Technology

      Vol:
    E81-C No:6
      Page(s):
    985-992

    A GaAs power amplifier IC has been developed for 1. 9-GHz digital mobile communication applications, such as the handsets of the Japanese personal handy phone system (PHS), which was assembled into a very small 0. 012-cc surface mount plastic package. This power amplifier using refractory WNx/W self-aligned gate MESFETs with p-pocket layers can operate with high efficiency and low distortion with a single 3-V supply. A very low dissipated current of 119 mA was obtained with an output power of 21. 1 dBm and a low 600-kHz adjacent channel leakage power (ACP) of -63 dBc for π/4-shifted quadrature phase shift keying (QPSK) modulated input.

  • Does Hertzian Contact Area Act as an Effective Zone Generating the Friction Resistance?

    Tadashi SASADA  Harumi NAKABAYASHI  

     
    PAPER

      Vol:
    E81-C No:3
      Page(s):
    326-329

    Coulombs law of friction, in which the coefficient of friction is constant independently of apparent area of contact and applied load, is deduced from the modern adhesion theory. That is, the friction resistance is caused by shearing of solid/solid junctions which are formed through plastic deformation of surface asperities of mating solids. In so-called point contact, on the other hand, different experimental results from Coulombs law have been sometimes reported. In these cases, coefficient of friction is not constant, but reduces with increasing normal load. A weighty interpretation for these facts developed formerly is that Hertzian contact area acts as an effective zone to generate the friction resistance. This interpretation has, however, an important doubt, as the Hertzian contact area is not formed through plastic but through elastic deformation of solids. If the friction resistance is generated in an elastic contact area, the adhesion theory of friction would be shaken at its standing basis. To give an explanation of this inconsistency between the experimental facts reported previously and the adhesion theory of friction, the authors propose a new idea in this paper. The plastic deformation occurs at surface asperities even in Hertzian contact. If the rubbing condition is kept dry, the friction resistance would be generated only at those plastically deformed zone dotted in the elastic contact area, so that Coulombs law is realized. If the rubbing condition is kept wet, the clearance between mating surfaces in the elastic contact zone is filled with any lubricant or contaminant molecules, the friction resistance would be generated through shearing of them within the Hertzian area. In this case, the coefficient of friction would be proportional to(load)-1/3, which is close to observational facts reported previously. An experimental verification made in this study can describe the authors proposal.

  • Influence of the Shape of Contact Surface on the Spatial Distribution of Spectral Intensity of Breaking Arcs in Palladium Contacts

    Mitsuru TAKEUCHI  Takayoshi KUBONO  

     
    PAPER

      Vol:
    E81-C No:3
      Page(s):
    384-391

    In a DC 50 V/5 A circuit, the relationship between the number of breaking arcs and the spatial distribution of the spectral intensity of breaking arcs of long duration near the cathode in palladium contact were examined through substitution of the contact surfaces of three different shapes: flat and spherical (1 mm radius and 2 mm radius). Findings show the distribution of spectral intensity in Pd arcs to be influenced remarkably by the shape of contact surface and the number of breaking arcs. However, the temperature of Pd arcs was affected neither by the shape of contact surface nor by the number of breaking arcs. The metal-vapor quantity present differed for flat and spherical surface contacts; however, it was not affected by the radius of the curved contact surfaces or by the number of breaking arcs. Additionally, the longer the duration of the breaking arc, the more metal-vapor was presented in the beginning of the arc. Furthermore, arc tracks on contact surfaces were observed with microscopes, clarifying that the relationship between the area of the clouded white metal on the cathode and the shape of contact surface is the same as the relationship between the existent area of measured spectra and the shape of the contact surface.

  • A Proposal on Contact Surface Model of Electromagnetic Relays Based on the Change in Showering Arc Waveforms with the Number of Contact Operations

    Kiyotomi MIYAJIMA  Shuichi NITTA  Atsuo MUTOH  

     
    PAPER

      Vol:
    E81-C No:3
      Page(s):
    399-407

    The showering arc waveforms generated when contact is being separate have poor reproducibility whose causes are not sufficiently clear. This paper describes that the contact surface conditions which change with the number of contact operations are deeply related to the showering arc waveforms. First, it is experimentally shown that the contacts' surface roughness increases with the number of contact operations, and the growth model of contact surface roughness is proposed based on the change of contact resistance for the number of contact operations. Second, the growth model of molten metal bridge is proposed based on the fact that the showering arc waveforms change with the number of contact operations and the evaluation indexes of showering arc are proposed.

  • Nonlinear Characteristics of Insulating LB Films with Nanometer Thickness Sandwiched between Au-Au Contact

    Isao MINOWA  Mitsumasa IWAMOTO  

     
    PAPER

      Vol:
    E81-C No:3
      Page(s):
    330-336

    It is well known that the existence of electrically resistive film layers formed on contact surfaces increases contact resistance and it causes a nonlinear relationship between voltage and current observed in a contact layer. Nonlinear distortion voltages can be detected by our sensitive detection system based on the dual frequency method when a thin film exists on the surface. In this study, multilayer films of polyimide (PI) was used as an ideal material of ultra thin film, because of electrically good insulator with simple molecular structure, to study non-linearity through metal-insulator-metal contact. The number of deposited layers between one and twenty one were formed on three types of substrates; (a) evaporated gold on a glass plate, (b) gold plate and (c) evaporated gold on gold plate, to obtain good insulating film. Where each layer of PI film has 0. 4 nanometer thickness. A pin contact was made by pressing a bent gold wire on the PI film. It is concluded that [1]; the second-order distortion voltage increases exponentially as the film thickness increases, [2]; polarity of the surface potential of PI depends on the film thickness, and that I-V characteristic depends on the polarity of the surface potential.

  • Application of Digital Image Measuring System (DIMS) and Shadow Image Processing Technique (SIPT) to Damage Analysis of Electrical Sliding Contact Surface

    Masanari TANIGUCHI  Miyataka KANAZAWA  Tasuku TAKAGI  

     
    PAPER

      Vol:
    E81-C No:3
      Page(s):
    377-383

    Surface damage of the electrical contact is a primary cause of failure in many electronic devices which use sliding contacts. Therefore, the quantitative observation of the contact surface is one of the most important subjects for improvement of contact reliability. In this study, in order to clarify the relationship between the contact resistance and the damage on the contact surface, a digital image measuring system (DIMS) was developed. A shadow image processing technique (SIPT) was applied to the damage analysis on the sliding contact surface. The damage width on the contact surface and the damaged image could be obtained with a 3-D graphic image by applying both DIMS and SIPT. Part of the relationship between the damage on the contact surface and the contact resistance could be obtained in the case when Cu is used for the moving contact and Cu and Ni are used for the static contact.

  • Natural Convection Cooling in Vertical Finned Plates in a Cabinet for Communication Equipment

    Norio NAKAZATO  Shigeki HIRASAWA  Takanori MATO  

     
    PAPER

      Vol:
    E81-C No:3
      Page(s):
    421-426

    A simulation model for natural convection was developed for determining the surface temperature distribution in base plates with rectangular vertical fins in communication equipment. An estimated velocity derived from the buoyancy and pressure drop equations in a duct was used for laminar forced convection cooling simulations in parallel plates. Temperature distributions in finned plates were calculated by numerical integration of the heat conduction equation. An experimental study was also performed, to check these simulation results, by changing the height of fins, the pitch of fins, and the heat generation conditions. Experimental results and analytical results were found to agree well. Also, this simulation method was extended to analyze natural convection cooling in vertical base plates with inclined parallel fins. We placed alternately on the plates the sections without fins and the sections with fins on the plates. Using the inclined fins, air flow rate between fins was large and fresh air flew into the fins from the side of the plates. The natural convective heat-transfer rate for inclined fins was found to be 14% higher than that for vertical fins.

  • A High-Resolution Measurement System for Surface Profile of Electric Contact

    Yasuo EBARA  Hideaki SONE  Yoshiaki NEMOTO  Tasuku TAKAGI  

     
    LETTER

      Vol:
    E81-C No:3
      Page(s):
    432-434

    We discussed on relationship between the width of slit ray and the accuracy of the measurement system for surface profile of electric contact. To obtain resolution of 10 [µm], we designed the mechanism which keeps constant the focal length between the object and the lens. As a result, the width of slit ray was clear in the whole surface. A section image could measured exactly and enhanced the resolution.

301-320hit(404hit)