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91.
To deal with uncertainty of the spectral distribution, we consider minimax interpolation and extrapolation problems in Lp for stationary processes. The interpolation and extrapolation problems can be regarded as a linear approximation problem on the unit disk in the complex plane. Although the robust one-step-ahead predictor and interpolator has already been considered separately in the previous literature, we give two conditions for the uncertainty class to find the minimax interpolator and extrapolator in the general framework from both the point of view of the observation set and the point of view of evaluation on the interpolation and extrapolation error under the Lp-norm. We show that there exists a minimax interpolator and extrapolator for the class of spectral densities ε-contaminated by unknown spectral densities under our conditions. When the uncertainty class contains spectral distribution functions which are not absolutely continuous to the Lebesgue measure, we show that there exists an approximate interpolator and extrapolator in Lp such that its maximal interpolation and extrapolation error is arbitrarily close to the minimax error when the spectral distributions have densities. Our results are applicable to the stationary harmonizable stable processes. 相似文献
92.
Suzuki Atsushi Taguchi Masaya Oku Takeo Okita Masanobu Minami Satoshi Fukunishi Sakiko Tachikawa Tomoharu 《Journal of Materials Science: Materials in Electronics》2021,32(22):26449-26464
Journal of Materials Science: Materials in Electronics - Fabrication and characterization of methylammonium lead iodide perovskite solar cells incorporated with methylammonium bromide (MABr),... 相似文献
93.
To clarify the effect of hydrogen gas on fretting fatigue strength of the materials, which supposed to be used for hydrogen utilization machines, fretting fatigue tests were conducted in hydrogen gas. It is important to take fretting fatigue into account in strength design, because many fatigue failure accidents have occurred at joints or contact parts between components. As a part of the experiments, an austenitic stainless steel was focused in this paper. The material was SUS 304. Fretting fatigue strength in hydrogen gas decreased compared with that in air. Tangential force coefficient increased in the reverse order of fretting fatigue strength. Therefore, one of the reasons of the decrease of fretting fatigue strength was that tangential force was different depending on the environment. Absorption of hydrogen occurred during fretting in hydrogen gas was detected. The absorption could be considered as one of the causes of the decrease of fretting fatigue strength, since fretting fatigue life of pre-charged specimen was decreased and also the crack propagation threshold of short fatigue crack was reduced by hydrogen charge. 相似文献
94.
Natsui Shungo Sudo Takuya Shibuya Ryota Nogami Hiroshi Kikuchi Tatsuya Suzuki Ryosuke O. 《Metallurgical and Materials Transactions B》2020,51(1):11-15
Metallurgical and Materials Transactions B - An in situ observation technique of the TiO2 interfacial behavior in molten LiCl-KCl electrolysis was developed. The variation of the thin TiO2... 相似文献
95.
The major challenge in wireless body area networks (WBAN) is setting up a protected communication between data consumers and a body area network controller while meeting the security and privacy requirements. This paper proposes efficient and secure data communication in WBANs using a Twofish symmetric algorithm and ciphertext‐policy attribute‐based encryption with constant size ciphertext; in addition, the proposed scheme incorporates policy updating to update access policies. To the best of the author's knowledge, policy updating in WBAN has not been studied in earlier works. The proposed scheme is evaluated in terms of message size, energy consumption, and computation cost, and the results are compared with those of existing schemes. The result shows that the proposed method can achieve higher efficiency than conventional methods. 相似文献
96.
97.
Zhang Lan Lu Jian Nogami Hirofumi Okada Hironao Itoh Toshihiro Arai Shozo 《Microsystem Technologies》2018,24(1):457-463
Microsystem Technologies - During the growth of Japanese cows, the ruminal pH value is an important physiological parameter, which remarkably affects their nutritional status. To monitor the health... 相似文献
98.
Guangming Li Masayuki Nogami Yoshihiro Abe 《Journal of the American Ceramic Society》1994,77(11):2885-2888
Borosilicate glasses, 5B2 O3 · 95SiO2 (mol%), containing TeO2 and ZnO nominally equivalent to 10 wt% Te and ZnTe were prepared by a solgel method from Si(OC2 H5 )4 , B(OCH3 )3 , H6 TeO6 , and Zn(NO3 )2 . A study by electron spectroscopy for chemical analysis (ESCA) showed that glasses heated at high temperature (450°C) in air contained both Te6+ and Te4+ ions on the surface layer, but that mainly Te4+ ions occurred inside the bulk glass. When solgel-derived borosilicate glasses containing the TeO2 compound were reduced at elevated temperature in a hydrogen atmosphere, Te crystallites ranging in size from 4 to 15 nm were produced at a lower temperature, between 200° and 250°C. The absorption edge moved from the infrared to the visible wavelength region as the particle size decreased to about 4 nm. For glasses containing both TeO2 and ZnO, ZnTe crystallites formed at high temperature—over 300°C—and existed along with the Te phase. 相似文献
99.
Masanobu Wakasa Kuniyuki Nakanishi Kenji Manago Tsutomu Isobe Yoshiyuki Eshita Masayuki Okamoto Toshiyuki Isshiki 《Microscopy research and technique》2016,79(1):14-22
Objective : The aim of this study was to clarify an influence of the fine structure of human tooth enamel to the yellowing teeth. Materials and methods : Sound maxillary first premolars of 15–50‐year‐old females that were extracted for the orthodontic treatment were used as the test samples. The tooth enamel sections of these teeth that prepared by ion polishing were observed by scanning electron microscopy (SEM). Furthermore, the fine structure of substance filling the inter‐rod spaces was analyzed by high resolution transmission electron microscopy (HRTEM). Results : In white tooth, the inter‐rod spaces were observed at the width of about 0.1 μm, while in yellow tooth, the inter‐rod spaces were not clearly observed by SEM. HRTEM observations revealed for the first time that the inter‐rod spaces were filled with fine particles of poorly crystallized hydroxyapatite in the yellow tooth. In yellow tooth, it was considered that the color of the inner dentin was recognized due to the decrease of light scattering by filling the tooth enamel inter‐rod spaces. The generation of particles in the tooth enamel inter‐rod spaces was considered to be caused by the long‐time progression of calcification. Conclusions : These results suggested that the change in fine structure, filling in inter‐rod spaces of tooth enamel, was related to progression of calcification in the inter‐rod spaces with advancing age and one of the factors of yellowness of human tooth. Microsc. Res. Tech. 79:14–22, 2016. © 2015 Wiley Periodicals, Inc. 相似文献
100.
Understanding the Structural Evolution and Redox Mechanism of a NaFeO2–NaCoO2 Solid Solution for Sodium‐Ion Batteries
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Kei Kubota Takuya Asari Hiroaki Yoshida Hiromasa Shiiba Masanobu Nakayama Shinichi Komaba 《Advanced functional materials》2016,26(33):6047-6059
Na‐ion batteries have become promising candidates for large‐scale energy‐storage systems because of the abundant Na resources and they have attracted considerable academic interest because of their unique behavior, such as their electrochemical activity for the Fe3+/Fe4+ redox couple. The high‐rate performance derived from the low Lewis‐acidity of the Na+ ions is another advantage of Na‐ion batteries and has been demonstrated in NaFe1/2Co1/2O2 solutions. Here, a solid solution of NaFeO2‐NaCoO2 is synthesized and the mechanisms behind their excellent electrochemical performance are studied in comparison to those of their respective end‐members. The combined analysis of operando X‐ray diffraction, ex situ X‐ray absorption spectroscopy, and density functional theory (DFT) calculations for Na1– x Fe1/2Co1/2O2 reveals that the O3‐type phase transforms into a P3‐type phase coupled with Na+/vacancy ordering, which has not been observed in O3‐type NaFeO2. The substitution of Co for Fe stabilizes the P3‐type phase formed by sodium extraction and could suppress the irreversible structural change that is usually observed in O3‐type NaFeO2, resulting in a better cycle retention and higher rate performance. Although no ordering of the transition metal ions is seen in the neutron diffraction experiments, as supported by Monte‐Carlo simulations, the formation of a superlattice originating from the Na+/vacancy ordering is found by synchrotron X‐ray diffraction for Na0.5Fe1/2Co1/2O2, which may involve a potential step in the charge/discharge profiles. 相似文献