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51.
Kentaro Yanagihara Jumpei Taketsugu Kiyoshi Fukui Shigeru Fukunaga Shinsuke Hara Ken-ichi Kitayama 《Wireless Personal Communications》2007,40(3):401-415
In this paper, we propose a new energy efficient clustering scheme with transmission power control named “EACLE” (Energy-Aware
CLustering scheme with transmission power control for sEnsor networks) for wireless sensor networks, which are composed of
the following three components; “EACLE clustering” is a distributed clustering method by means of transmission power control,
“EACLE routing” builds a tree rooted at a sink node and sets the paths from sensor nodes taking energy saving into consideration,
and “EACLE transmission timing control” changes the transmission timing with different levels of transmission power to avoid
packet collisions and facilitates packet binding.
With an indoor wireless channel model which we obtained from channel measurement campaigns in rooms and corridors and an energy
consumption model which we obtained from a measurement of a chipset, we performed computer simulations to investigate the
performance of EACLE in a realistic environment. Our simulation results indicate that EACLE outperforms a conventional scheme
such as EAD (Energy-Aware Data-centric routing) in terms of communication success rate and energy consumption. Furthermore,
we fully discuss the impact of transmission power and timing control on the performance of EACLE. 相似文献
52.
Bit-patterned media (BPM) consisting of land parts for read/writing and grooves, which are almost filled with non-magnetic materials to prevent magnetic interference between recording bits, are considered to be promising media for achieving ultrahigh density recording. A flying head slider flying over a BPM disk suffers from variations in both the spacing and van der Waals (vdW) attractive forces, which induce slider vibrations and spacing fluctuations. In the present study, we considered that BPM disks not only have a groove depth distribution, but that they also have a distribution of material properties (e.g., refractive index), which gives rise to a distribution in the vdW force. In the dynamic responses of sliders with small groove depths and a small variation in the refractive index, spacing fluctuations are found to be a superposition of fluctuations due to slider behaviors (1) over a disk with transverse grooves in a uniform material with a uniform refractive index (Case 1) and (2) over a flat disk with a refractive index distribution (Case 2). When the effects of Cases 1 and 2 cancel each other, the spacing fluctuations for the two cases cancel each other, reducing the total spacing fluctuation. 相似文献
53.
Yasuyoshi Fukui Hiroshi Okada Noriyoshi Kumazawa Yashimi Watanabe 《Metallurgical and Materials Transactions A》2000,31(10):2627-2636
A possibility to make near-net-shape functionally graded material (FGM) products has been examined. The FGM billets having
a graded volume fraction of Al3Ni in thickness direction were machined from an Al-Al3Ni FGM thick-walled tube manufactured by a vacuum centrifugal method. Billets, which were set in the container for the backward
extruding, were heated to 650 °C to 680 °C, at which temperature the FGM becomes a mixture of molten aluminum eutectic and
solid intermetallics. Then, billets were extruded successfully to FGM cups by a semisolid forming, except at 650 °C. Residual
bulky Al3Ni particles are found at higher temperature. Thus, an optimum operation temperature is found to be around 660 °C, because
bulky Al3Ni particles transform to fine spheroidal or fibrous shape after the forming. The volume fraction of intermetallics at the
bottom region of the cup was condensed more than 60 vol pct in a proper billet setting. 相似文献
54.
Masayuki Itagaki Isao Shitanda Wataru Nakamura Kunihiro Watanabe 《Electrochimica acta》2007,52(23):6421-6426
A partial nickel plating method was developed by using the organic gel electrolyte. The gel electrolyte was made from polyvinylchloride as a gelling agent and tetrahydrofuran as an organic solvent. The suitable conditions for nickel plating were investigated by the measurements of polarization curve and electrochemical impedance. The pattern electroplating using thin layer of gel electrolyte was carried out on the copper substrate. The substrate surface could be plated by nickel with high uniformity and sharp edge line. The present method will be widely used for the surface patterning without masking. 相似文献
55.
Development of multianode photomultiplier tube 总被引:1,自引:0,他引:1
Fumuhiko Takasaki Hitoshi Saito Tohru Fukui Teruhiko Matsushita Toshihiro Suzuki 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1987,260(2-3):447-450
We have developed a multianode photomultiplier tube (MAPMT) which has a sensitive cathode diameter of 36 mm and an anode with 88 segments. The position sensitivity of the tube was studied by using light from a LED and scintillation light from a scintillation-fiber bundle. We observed particle tracks for the first time by using a single photomultiplier tube. 相似文献
56.
The stannous ion consumption in methane sulfonic acid (MSA) baths with and without catechol was quantitatively evaluated using platinum and IrO2–Ta2O5/Ti anodes. The stannous ion is consumed at the same rate with both anodes, accompanied by the generation of tin sludge on the anode surfaces in the bath without catechol, while these undesirable phenomena are significantly suppressed in the bath containing catechol. Spectroscopic measurements indicate that stannous ion and catechol form a complex at the mole ratio of 1:2, thus preventing the oxidation of stannous ions. This complexation effect is independent of the anode material at low current density, but depends on the anode material at high current density. The stannous ion consumption at high current density is sufficiently inhibited only with the IrO2–Ta2O5/Ti anode due to the low oxygen evolution potential. Voltammetric measurements also suggest that the continuous oxidation of stannous ion in the catechol-containing bath is simultaneous with oxygen evolution. 相似文献
57.
Masahiro Shirato Yoshinori Nonomura Jiro Fukui Shoichi Nakatani 《Soils and Foundations》2008,48(3):375-396
This paper describes the results of large-scale shake-table experiments involving a 3×3 pile-group. The pile-group was embedded in dry sand and subjected to sinusoidal waves and an earthquake motion recorded from the 1995 Hyogo-ken Nanbu (Kobe) earthquake. The load transfer between soil and pile was derived and the group effect was captured. Numerical simulations were also performed using a Beam-on-Nonlinear-Winkler-Foundation approach with a new hysteretic p-y curve. A comparison of the experimental and numerical results revealed that the numerical simulation is capable of accounting for the soil-pile interaction observed in the experiment. 相似文献
58.
A mechanistic aspect of the susceptibility to the delayed fracture is studied with an emphasis on the critical behaviour of the subsurface growth of Quasi-Cleavage (QC) and Inter-Granular (IG) cracks. The materials employed are 0.35%C plain carbon steel and boron added bolt steel which were quenched and tempered to have various levels of yield strength ranging from 500 to 1400 MPa. Fractographic analysis shows us that QC + IG cracking process can be an essential mode in the delayed fracture of steels. A low susceptibility to delayed fracture can be explained by the crack growth behavior when the crucial blunting occurs at the crack tip. 相似文献
59.
60.
A. Mizuno T. Nagahama A. Morihira H. Ogawa N. Mizuno Y. Yonekura H. Yamamoto H. Nakane Y. Fukui 《Journal of Infrared, Millimeter and Terahertz Waves》2002,23(7):981-995
A new sensitive radiometer for atmospheric minor constituents has been developed by Nagoya University and the National Institute for Environmental Studies (NIES). The instrument equipped low-noise superconducting (SIS) mixer with a system noise temperature of ≈200K (SSB) at 204GHz. The SIS mixer is operated in a single side band mode with a side band ratio grater than 10dB by adjusting the two tunable backshorts of the mixer. Since any additional SSB filters are not necessary, we can simplify the quasi-optical system and reduce the standing waves which makes difficult to achieve a flat spectral baseline. We installed the observation system at Las Campanas Observatory, Chile in December 1999, and started the test observation from 2000 October. We have detected significant ClO emission at 204.3 GHz with an actual observation time of only 4 hours. This is the first detection of the ClO at 40km altitude from the mid-latitude region of the southern hemisphere. The Nagoya-NIES system has enabled continuous monitoring of ClO in the stratosphere with a time resolution of 4 or 5 hours. 相似文献