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

Keyword Search Result

[Keyword] ROS(1068hit)

761-780hit(1068hit)

  • On the Fault-Tolerant Hamiltonicity of Faulty Crossed Cubes

    Wen-Tzeng HUANG  Yen-Chu CHUANG  Jimmy Jiann-Mean TAN  Lih-Hsing HSU  

     
    PAPER-Graphs and Networks

      Vol:
    E85-A No:6
      Page(s):
    1359-1370

    An n-dimensional crossed cube, CQn, is a variation of the hypercube. In this paper, we prove that CQn is (n-2)-Hamiltonian and (n-3)-Hamiltonian connected. That is, a ring of length 2n-fv can be embedded in a faulty CQn with fv faulty nodes and fe faulty edges, where fv+fen-2 and n3. In other words, we show that the faulty CQn is still Hamiltonian with n-2 faults. In addition, we also prove that there exists a Hamiltonian path between any pair of vertices in a faulty CQn with n-3 faults. The above results are optimum in the sense that the fault-tolerant Hamiltonicity (fault-tolerant Hamiltonian connectivity respectively) of CQn is at most n-2 (n-3 respectively). A recent result has shown that a ring of length 2n-2fv can be embedded in a faulty hypercube, if fv+fen-1 and n4, with a few additional constraints. Our results, in comparison to the hypercube, show that longer rings can be embedded in CQn without additional constraints.

  • Effect of Surface Hydrophilicity and Solution Chemistry on the Adsorption Behavior of Cytochrome c in Quartz Studied Using Slab Optical Waveguide (SOWG) Spectroscopy

    Jose H. SANTOS  Naoki MATSUDA  Zhi-mei QI  Akiko TAKATSU  Kenji KATO  

     
    PAPER-Optoelectronics and Photonics

      Vol:
    E85-C No:6
      Page(s):
    1275-1281

    The adsorption behavior of cytochrome c was investigated using slab optical waveguide (SOWG) absorption spectroscopy at the near ultraviolet region utilizing thin quartz plates as planar waveguides. SOWG absorption spectra of cytochrome c measured at constant time intervals showed significant influence of surface hydrophilicity and solution chemistry on the adsorption of this important heme protein in quartz surface. Being polar and typically amphoteric, the protein preferred adsorption on hydrophilic surface than on hydrophobic surface as implied by the lower absorbance data obtained in the latter than in the former. At lower ionic strength and in the absence of buffer, the protein molecules tend to adsorb on the quartz surface. Plots of near steady-state absorbance versus protein concentration follow hyperbolic pattern in the absence of buffer or at low ionic strength and become more linear as the buffer concentration is increased. The results presented here are explained in terms of the general qualitative understanding of protein adsorption at solid-aqueous interfaces and further aids in elucidating the properties of protein monolayers and films.

  • Prospects of Electron Spectroscopy of Working Organic Electronic Device Structures

    Toshihiro SHIMADA  Atsushi KOMA  

     
    LETTER-Fabrication and Characterization of Thin Films

      Vol:
    E85-C No:6
      Page(s):
    1330-1331

    The prospects of electron spectroscopy of working organic electronic device structures are discussed. The experimental consideration and the result of actual measurement are presented.

  • Improvements in Solution of Integral Eigenvalue Equations for Waveguides of Arbitrary Cross Section

    Nguyen Hoang HAI  Masao KODAMA  

     
    PAPER-Optoelectronics

      Vol:
    E85-C No:5
      Page(s):
    1156-1163

    Cutoff frequencies and the modal fields in hollow conducting waveguides of arbitrary cross section are frequently calculated by the method of solving integral equations. This paper presents some improvements for the method by the integral equations. The improved method can calculate the cutoff frequencies and the modal fields only by using the real number, and this method can remove extraneous roots when calculating the cutoff frequencies. The former method calculates the cutoff frequency and the fields only at the cutoff frequency, but the improved method can calculate the fields at arbitrary phase constants.

  • All-Optical Wavelength Conversion Using Ultra-Fast Nonlinearities in Optical Fiber

    Shigeki WATANABE  Fumio FUTAMI  

     
    INVITED PAPER

      Vol:
    E85-C No:4
      Page(s):
    889-895

    The effectiveness and possible applications of all-optical wavelength conversion using optical fibers are described. Several types of ultra-broad and ultra-fast wavelength conversion using highly-nonlinear fiber are shown. Over 70 nm conversion band by four-wave mixing, 500-fs pulse trains conversion by cross-phase-modulation-based nonlinear optical loop mirror and time-based optical add-drop multiplexing for 160 Gbit/s signal using wavelength conversion by supercontinuum are successfully demonstrated.

  • Matching Josephson Junctions with Microstrip Lines for SFQ Pulses and Weak Signals

    Nikolai JOUKOV  Yoshihito HASHIMOTO  Vasili SEMENOV  

     
    PAPER-Digital Devices and Their Applications

      Vol:
    E85-C No:3
      Page(s):
    636-640

    We report recent achievements in interfacing Josephson junction circuits with superconductor MicroStrip Lines (MSLs). We studied basic techniques that allow satisfactory operation of different devices with MSLs. Successful operation of the interfaces with very low error rate has been demonstrated even at the MSL resonant frequency.

  • Microwave Surface Resistance Measurement Sensitivity of HTS Thin Films by Microstripline Resonator at Fundamental and Higher Resonant Modes

    Narayan D. KATARIA  Mukul MISRA  

     
    PAPER-Microwave Devices and Systems

      Vol:
    E85-C No:3
      Page(s):
    696-699

    The measurement sensitivity of microwave surface resistance, Rs, of high temperature superconducting (HTS) thin films using half-wavelength microstrip resonator with copper and HTS ground plane is analyzed for fundamental and higher order modes of the resonator. The estimated sensitivity of Rs-measurement is at least an order of magnitude greater at fundamental resonant frequency compared to when measured using higher order harmonic modes.

  • Intrinsic Josephson Junctions in BiSrCaCuO-2212: Recent Progress

    Huabing WANG  Jian CHEN  Lixing YOU  Peiheng WU  Tsutomu YAMASHITA  

     
    INVITED PAPER-Microwave Devices and Systems

      Vol:
    E85-C No:3
      Page(s):
    691-695

    In this paper, we review the progress in BiSrCaCuO-2212 Intrinsic Josephson junctions (IJJs) by summarizing our recent results in fabrication and high frequency experiments. Using a double-side fabrication process, a well defined number of intrinsic Josephson junctions in a well defined geometry can be fabricated. The junctions in the stack are quite homogeneous, and the power distribution of external irradiation among the junctions is even. Shapiro steps are clearly observed up to 2.5 THz, and the general condition for the occurrence of Shapiro steps at frequency frf is that it should be much greater than the plasma frequency fpl. Under certain conditions the Shapiro steps are zero-crossing, making some applications possible, such as quantum voltage standard etc.

  • A Novel All-Direction On-Chip Protection Circuit

    Haigang FENG  Ke GONG  Rouying ZHAN  Albert Z. H. WANG  

     
    PAPER-Circuit

      Vol:
    E85-C No:3
      Page(s):
    566-571

    A new low-voltage, all-in-one ESD (electrostatic discharging) protection circuit was designed. One such ESD protection unit is enough to protect each I/O pad against ESD stresses of all modes, i.e., from I/O to power supply and ground positively and negatively. This novel ESD circuit features adjustable trigger-voltage, i.e., 5 V to 60 V, with low turn-on threshold down to 5 V, symmetric active discharging channels in all directions, fast response time of 0.1 to 0.3 ns, and high ESD performance/area ratio of greater than 80 V per micrometer width. It was implemented in commercial BiCMOS technologies and achieved 14 kV human body model (HBM) and 15 kV air-gap IEC ESD protection levels. This compact ESD structure can not only provide adequate ESD protection, but also minimize the ESD-induced parasitic effects, which makes it a suitable ESD protection solution for mixed-signal and RF ICs in very deep sub-micron regime.

  • Flux-Quantum Transitions in a Three-Junction SQUID Controlled by Two RF Signals

    Yoshinao MIZUGAKI  Jian CHEN  Kensuke NAKAJIMA  Tsutomu YAMASHITA  

     
    PAPER-Novel Devices and Device Physics

      Vol:
    E85-C No:3
      Page(s):
    803-808

    We present analytical and numerical results on the flux-quantum transitions in a three-junction superconducting quantum interference device (3J-SQUID) controlled by two RF signals. The 3J-SQUID has two superconducting loops, and the RF signals are magnetically coupled to the loops. Flux-quantum transitions in the 3J-SQUID loops can be controlled by utilizing the phase difference of the two RF signals. Under proper conditions, we can obtain a situation where one flux quantum passes through the 3J-SQUID per one cycle of the RF signals without DC current biasing, which results in a zero-crossing step on the current-voltage characteristics. In this paper, we first explain the operation principle by using a quantum state diagram of a 3J-SQUID. Next, we numerically simulate RF-induced transitions of the quantum states. A zero-crossing step on the current-voltage characteristics is demonstrated. We also investigate dependence of zero-crossing steps upon parameters of the 3J-SQUID and RF signals.

  • NDE of Semiconductor Samples and Photovoltaic Devices with High Spatial Resolution Utilizing SQUID Photoscanning

    Thomas SCHURIG  Jorn BEYER  Dietmar DRUNG  Frank LUDWIG  Anke LUDGE  Helge RIEMANN  

     
    INVITED PAPER-SQUIDs and Their Applications

      Vol:
    E85-C No:3
      Page(s):
    665-669

    SQUID (Superconducting QUantum Interference Device) Photoscanning is an analytical technique intended for the noninvasive evaluation of semiconductor wafers and device structures. This method is based on the detection of the magnetic field of photocurrents locally induced in the sample under investigation by a focused laser beam. The magnetic field is monitored by means of a sensitive SQUID magnetometer while scanning the sample surface with the laser beam. Doping inhomogeneities in electronic grade silicon, grain boundaries in solar silicon, and defects in photovoltaic device structures have been analyzed.

  • Physical Design Methodology for On-Chip 64-Mb DRAM MPEG-2 Encoding with a Multimedia Processor

    Hidehiro TAKATA  Rei AKIYAMA  Tadao YAMANAKA  Haruyuki OHKUMA  Yasue SUETSUGU  Toshihiro KANAOKA  Satoshi KUMAKI  Kazuya ISHIHARA  Atsuo HANAMI  Tetsuya MATSUMURA  Tetsuya WATANABE  Yoshihide AJIOKA  Yoshio MATSUDA  Syuhei IWADE  

     
    PAPER-Product Designs

      Vol:
    E85-C No:2
      Page(s):
    368-374

    An on-chip, 64-Mb, embedded, DRAM MPEG-2 encoder LSI with a multimedia processor has been developed. To implement this large-scale and high-speed LSI, we have developed the hierarchical skew control of multi-clocks, with timing verification, in which cross-talk noise is considered, and simple measures taken against the IR drop in the power lines through decoupling capacitors. As a result, the target performance of 263 MHz at 1.5 V has been successfully attained and verified, the cross-talk noise has been considered, and, in addition, it has become possible to restrain the IR drop to 166 mV in the 162 MHz operation block.

  • Fluorescence Image Analysis for Quantification of Reactive Oxygen Species Derived from Monocytes Activated by Photochemical Reaction

    Miho TAKAHASHI  Tomokazu NAGAO  Yoshiharu IMAZEKI  Kazuki MATSUZAKI  Haruyuki MINAMITANI  

     
    PAPER-Cellular Imaging

      Vol:
    E85-D No:1
      Page(s):
    160-166

    This study attempts to demonstrate that activated leukocytes are involved in vascular shut down effect (VSD) in photodynamic therapy (PDT). Hydrogen peroxide (H2O2), a reactive oxygen specie (ROS) that is found in monocytes, was visualized under a confocal laser scanning microscope, and ROS formation was quantified by fluorescence image analysis. The fluorescence intensity was expressed as a gray level graded from 0 to 255. Only the fluorescence derived from monocytes that had ZnCP-III incorporated and were irradiated with an HeNe laser caused increases in the fluorescence distribution over time, while no change of distribution was observed in three other conditions (only Zn CP-III added, only HeNe laser irradiation, or non-treated). The result indicates that the photochemical reaction induced by excitation of a photosensitizer, and ROS was derived from the reaction-stimulated monocytes. The activated monocytes generated ROS themselves and H2O2 was visualized by the DCFH fluorescence method. In conclusion, the result clearly shows that activated monocytes are involved in the VSD effect.

  • Quantitative Analysis for Intracellular Distribution of a Photosensitizer Using Confocal Laser Scanning Microscope

    Tomokazu NAGAO  Kazuki MATSUZAKI  Miho TAKAHASHI  Yoshiharu IMAZEKI  Haruyuki MINAMITANI  

     
    PAPER-Cellular Imaging

      Vol:
    E85-D No:1
      Page(s):
    152-159

    Confocal laser scanning microscope (CLSM) is capable of delivering a high axial resolution, and with this instrument even thin layers of cells can be imaged in good quality. Therefore, intracellular uptake and distribution properties of photosensitizer zinc coproporphyrin III tetrasodium salt (Zn CP-III) in human lung small cell carcinoma (Ms-1) were examined by using CLSM. In particular, the uptake of Zn CP-III in cytoplasm, plasma membrane, and nucleus was individually evaluated for the first time from fluorescence images obtained by CLSM. The results show that the Zn CP-III content in three cellular areas correlates with extracellular Zn CP-III concentration and time of incubation with Zn CP-III. Furthermore, it was found that the cytoplasmic fluorescence was approximately two times higher than that in the nucleus under all uptake conditions. In addition, cellular accumulation of Zn CP-III was compared with photodynamic cytotoxicity. The photocytotoxicity was to a great extent dependent on the uptake of the photosensitizer. The damaged site of Ms-1 cells induced by photodynamic therapy was plasma membrane. However, the content of Zn CP-III accumulated in cytoplasm was the highest among the three areas, implying that, besides the direct damage on plasma membrane, an oxidative damage to cellular component arose from the cytoplasmic Zn CP-III may also play an important role in photocytotoxicity. The quantitative information obtained in this study will be useful for further investigation of the photocytotoxicity as well as the uptake mechanism of photosensitizer.

  • Measurement of the Electrical Properties of Tissue--New Developments in Impedance Imaging and Spectroscopy--

    Brian BROWN  

     
    INVITED PAPER

      Vol:
    E85-D No:1
      Page(s):
    2-4

    Human tissues conduct electricity about as well as semiconductors. However, there are large differences between tissues which have recently been shown to be determined mainly by the structure of the tissue. For example, the impedance spectrum of a layered tissue such as skin is very different to that of the underlying tissues. The way in which the cells are arranged and also the size of the nucleus are both important. Some of the recent developments in measurement and modelling techniques are described and the relationship between tissue structures and impedance spectra is outlined. The illustrations and examples look at the effect of premalignant changes on localised impedance spectra measured from cervical tissues. Electrical Impedance Tomographic measurements on lung tissue are used to show the maturational changes of lung structure in neonates. The conclusion contains some speculation as to what further research outcomes might occur over the next few years.

  • Low-Crosstalk LD and PD Arrays with Isolated Electrodes for Parallel Optical Communications

    Naofumi SUZUKI  Kazuhiko SHIBA  Takumi TSUKUDA  Takahiro NAKAMURA  

     
    PAPER

      Vol:
    E85-C No:1
      Page(s):
    93-97

    Low-crosstalk 1.3-µm Fabry-Perot laser diode (FP-LD) and photodiode (PD) arrays are developed. The arrays are fabricated on semi-insulating substrates and their anodes and cathodes are separated channel by channel to suppress inter-channel electrical crosstalk at high frequency. Crosstalk of less than -30 dB is achieved between neighboring LDs at 3.125 GHz. This is low enough for BER characteristics observed under asynchronous operation of a 4-channel LD array to be no worse than those under single-channel operation. Excellent uniformity of both LD and PD characteristics, high-temperature operation of the LD array, and low-voltage operation of the PD array are also attained. These arrays are suitable for low-cost high-bit-rate parallel optical communications.

  • A 200-Channel Imaging System of Muscle Oxygenation Using CW Near-Infrared Spectroscopy

    Masatsugu NIWAYAMA  Katsuyuki YAMAMOTO  Daisuke KOHATA  Kosuke HIRAI  Nobuki KUDO  Takafumi HAMAOKA  Ryotaro KIME  Toshihito KATSUMURA  

     
    PAPER-Optical Imaging

      Vol:
    E85-D No:1
      Page(s):
    115-123

    We have developed a 200-channel imaging system that enables measurement of changes in oxygenation and blood volume and that covers a wider area (45 cm 15 cm) than that covered by conventional systems. This system consisted of 40 probes of five channels, a light-emitting diode (LED) driver, multiplexers and a personal computer. Each probe was cross-shaped and consisted of an LED, five photo diodes, and a current-to-voltage (I-V) converter. Lighting of the LEDs and acquisition of 200-channel data were time-multiplexed. The minimum data acquisition time for 200 channels, including the time required for calculation of oxygenation and monitoring of a few traces of oxygenation on a computer display, was about 0.2 s. We carried out exercise tests and measured the changes in oxy- and deoxy-hemoglobin concentrations in the thigh. Working muscles in exercises could be clearly imaged, and spatio-temporal changes in muscle oxygenation during exercise and recovery were also shown. These results demonstrated that the 200-channel imaging system enables observation of the distribution of muscle metabolism and localization of muscle function.

  • Vector Signal Processing for 60-120 GHz Gas Absorption Measurement

    Toshitatsu SUZUKI  Hidenori SASANUMA  Masashi SANO  Kenichi SHIODA  Yasuo WATANABE  

     
    PAPER

      Vol:
    E84-C No:12
      Page(s):
    1900-1904

    This study is intended to realize an in-situ gas sensor based upon the principle of millimeter/submillimeter wave spectroscopy. In-situ gas sensor will be attractive because of gas selectivity, multiple parametric measurement such as gas temperature, pressure and density, and of the in-situ measurement capability. One of the major technical problem to be solved is to develop an instrument accurate enough to discern the spectrum change due to the variation of parameters such as temperature. In this paper a proposed gas absorption measurement system is investigated, which schematically consists of Fabry-Perot type gas cell for effective long path length, and vector signal processing to reject leak signal coupled between resonator input and output ports so as to achieve precise absorption measurement. Also included is an parametric study of oxygen absorption characteristics, which is served as the predicted value in the evaluation of the instrument. The experiment at 60 GHz and 120 GHz bands using oxygen demonstrates the effectiveness of the current system configuration.

  • High Resolution Long Array Thermal Ink Jet Printhead with On-Chip LSI Heater Plate and Micromachined Si Channel Plate

    Michiaki MURATA  Masaki KATAOKA  Regan NAYVE  Atsushi FUKUGAWA  Yoshihisa UEDA  Tohru MIHARA  Masahiko FUJII  Toshimichi IWAMORI  

     
    PAPER

      Vol:
    E84-C No:12
      Page(s):
    1792-1800

    This paper presents a high resolution long array thermal ink jet (TIJ) printhead which has been developed and demonstrated to operate successfully by combining two functional Si wafers, a bubble generating heater plate fabricated using LSI process and a channel plate fabricated using Si bulk micromachining technology. The heater plate consists of logic LSIs, high voltage MOS transistor, polycrystalline Si (Poly Si) heating resistor and polyimide protective layer. The polymide layer is patterned by O2 plasma reactive ion etching (RIE) and is applicable to high resolution heater array. The Si channel plate consists of an ink chamber and an ink inlet formed by KOH etching, and a nozzle formed by inductively coupled plasma RIE (ICP RIE). The nozzle formed by RIE has squeezed structures which contribute to high energy efficiency of drop ejector and therefore successful ejection of small ink drop. These two wafers are directly bonded by using a novel electrostatic bonding of full-cured polyimide to Si. The adhesive-less bonding provided an ideal shaped small nozzle orifice. And also, the bonding method enabled to use an on-chip LSI wafer because of the contamination free material and the suitable processing conditions (low temperature). The bonded wafer is diced to form printhead chip. No delamination or displacement of the chip was observed even though the chip was subjected to thermal stress during assembly process. This is because of no difference in thermal expansion coefficient between both chips (Si and Si). And therefore it is suitable for long chip concept. With the above technologies, we have fabricated a 1.3" long printhead with 1024 nozzles having a 800 dots per inch (dpi) resolution, a 2.7 pl. ink drop volume, 14 m/sec. ink drop velocity and 18 kHz jetting frequency. And we have confirmed high speed printing and high quality printing.

  • Characteristic Analysis of Large Bandwidth Dual-Offset Microstrip-Fed Printed Slot Antenna Using FDTD Method

    Yong-Woong JANG  

     
    LETTER-Antenna and Propagation

      Vol:
    E84-B No:11
      Page(s):
    3072-3074

    A dual-offset microstrip-fed slot antenna having large bandwidth studied in this paper. The proposed antenna is analyzed by the Finite Difference Time Domain (FDTD) method. In this case, two offsets and other design parameters of the antenna lead to the good impedance matching over a wide frequency band. The experimental bandwidth is approximately 1.587 octave (-10 dB S11). And the experimented data for the impedance loci, the radiation patterns, and gain of the antenna are also described. The measured results are relatively in good agreement with the FDTD results.

761-780hit(1068hit)