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排序方式: 共有1564条查询结果,搜索用时 15 毫秒
21.
This paper proposes bootstrap robust estimation methods for the Weibull parameters; it applies bootstrap estimators of order statistics to the parametric estimation procedure. Estimates of the Weibull parameters are equivalent to the estimates using the extreme value distribution. Therefore, the bootstrap estimators of order statistics for the parameters of the extreme value distribution are examined. Accuracy and robustness for outliers are examined by Monte Carlo experiments which indicate adequate efficiency of the proposed reliability estimators for data with some outliers 相似文献
22.
23.
Harada N. Yoshida A. Yokoyama N. 《Applied Superconductivity, IEEE Transactions on》2002,12(3):1852-1856
The high-speed operation of a one-channel output interface for a single-flux quantum (SFQ) system has been demonstrated. The interface consisted of a Josephson latching driver, a room-temperature semiconductor amplifier, and a decision circuit module. The Josephson latching driver was fabricated by using a 2.5-kA/cm2 standard Nb junction process and used to amplify an SFQ pulse into a 5.5-mV level signal at 10 Gb/s. The interface converted the SFQ pulse signal into a nonreturn-to-zero signal having an amplitude of 1 V at 10 Gb/s 相似文献
24.
Tetsuya Suemitsu Yoshino K. Fukai Hiroki Sugiyama Kazuo Watanabe Haruki Yokoyama 《Microelectronics Reliability》2002,42(1):47-52
The reliability of InP-based HEMTs is studied, focussing on how it is affected by the doped layer material and gate recess structure. Bias-and-temperature stress tests reveal that fluorine-induced donor passivation in the recess region, formed adjacent to the gate electrode, causes the source resistance (Rs) to increase at large drain bias voltages. The increase in Rs can be prevented by using InP or InAlP as the carrier supply layer material instead of InAlAs. On the other hand, the increase in the drain resistance (Rd) does not depend on the material of the carrier supply layer, which suggests that a mechanism different from that in the case of Rs should be considered. It is also found that a deep gate recess suppresses the increase in Rd after long-term stressing. 相似文献
25.
D. Xu T. Enoki T. Suemitsu Y. Umeda H. Yokoyama Y. Ishii 《Journal of Electronic Materials》1998,27(7):L51-L53
We have achieved a self-controlled asymmetrical etching in metalorganic chemical vapor deposition-grown InAlAs/InGaAs heterostructures,
which can be suitable for fabricating modulation-doped field-effect transistors (MODFETs) with gate-groove profiles for improved
performance. The technology is based on electrochemical etching phenomena, which can be effectively controlled by using different
surface metals for ohmic electrodes. When surface metals of Pt and Ni are deposited on the source and the drain, respectively,
the higher electrode potential of Pt results in slower etching on the source side than on the drain side. Thus, asymmetry
of gate grooves can be formed by wet-chemical etching with citric-acid-based etchant. This represents a new possibility to
conduct “recess engineering” for InAlAs/InGaAs MODFETs. 相似文献
26.
G. Meneghesso R. Luise D. Buttari A. Chini H. Yokoyama T. Suemitsu E. Zanoni 《Microelectronics Reliability》2000,40(8-10)
A study of InP based HEMTs implemented with different process options will be reported. It will be demonstrated that devices with an InP etch stopper layer or with a narrow lateral gate recess region do not present any kink effect, neither any transconductance frequency dispersion, gm(f) and a stable behavior with respect to hot electron aging is observed. The opposite occurs in devices without the InP etch stopper layer and a wide lateral gate recess region. The data presented confirm the effectiveness of an InP passivating layer in improving the reliability of advanced InP-HEMTs, and point out at the free InAlAs surface as responsible for the observed instabilities (kink effects, gm(f) dispersion). 相似文献
27.
An ultra-compact Mach-Zehnder (MZ) electro-optic (EO) modulator composed of nanoscale metal gap waveguides is numerically demonstrated. Propagation of surface plasmon polaritons in nano-size channels and their EO modulations is investigated by the finite-difference time-domain method considering the Lorentz-Drude model. The half-wave voltage (V pi) of the resulting MZ modulator for push-pull operation is 1.73 V using the interference arm with a sub-micron length (500-nm). 相似文献
28.
Yokoyama A. King R.W.P. Sandler S.S. 《Antennas and Propagation, IEEE Transactions on》1995,43(5):541-544
Yokoyama makes some comments on the “numerical distance” contained in the surface wave term in the paper by King and Sandler (see ibid., vol.42, p.383, 1994) comparing it with the one obtained by former authors. He comments on the parameter P in the Fresnel-integral term in the paper. Yokoyama concludes that for the calculation of such a problem in a semi-sphere, the spherical polar coordinate system is preferable to the cylindrical coordinate system including the case of lateral waves. King and Sandler reply to the Comment 相似文献
29.
Shigekawa N. Nishimura K. Suemitsu T. Yokoyama H. Hohkawa K. 《Electron Device Letters, IEEE》2007,28(2):90-92
We proposed surface acoustic wave (SAW) filters composed of interdigital Schottky and ohmic contacts on AlGaN/GaN heterostructures. The contribution of the SAWs appeared in the radio frequency characteristics of the filters when the Schottky contacts were reverse biased. Onsets of the SAW signals and the threshold voltage of simultaneously fabricated high-electron mobility transistors were found to almost agree with one another. We also obtained an isolation of >40 dB. These results suggest that SAW-based functional devices are likely to be realized using AlGaN/GaN heterostructures with interdigital Schottky and ohmic contacts 相似文献
30.
Yamashita J. Yamauchi Y. Mochimaru M. Fukui Y. Yokoyama K. 《IEEE transactions on bio-medical engineering》1999,46(1):107-116
This paper presents a three-dimensional (3-D)-model-based navigation system for endoscopic sinus surgery treating paranasal sinusitis. Endoscopic surgery is becoming more common because of its low invasiveness. Its problem with disorientation, however, is one of the toughest barriers for the novice and may lead even an expert to commit serious surgical errors, e.g., causing cerebrospinal fluid (CSF) leakage or blinding the patient. To prevent such complications and optimize training, the authors' system aids in navigation by showing a single perspective view of the patient and the endoscope models. This virtual endoscope has a viewing cone with a simulated light to indicate the viewing direction and visual field in real-time. The system's three clipping planes automatically follow the endoscope and help keep the surgeon aware of the endoscope's actual position. An experiment comparing the system to conventional navigation using a triplanar display showed that the perspective view was referenced very frequently, giving a positive impressions, while the triplanar display was almost completely ignored, apparently because it was too difficult to interpret immediately 相似文献