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81.
82.
We introduce a new condition for {Yτn} to have the same asymptotic distribution that {Yn} has, where {Yn} is a sequence of random elements of a metric space (S, d) and {τn} is a sequence of random indices. The condition on {Yn} is that maxiDnd(Yi, Yan)→p0 as n → ∞, where Dn = {i: |ki−kan| ≤ δankan} and {δn} is a nonincreasing sequence of positive numbers. The condition on {τn} is that P(|(kτn/kan)−1| > δan) → 0 as n → ∞. Under these conditions, we will show that d(Yτn, Yan) → P0 and apply this result to the CLT for a general class of sequences of dependent random variables. 相似文献
83.
An Integrated Circuit for Two-Dimensional Edge-Detection with Local Adaptation Based on Retinal Networks 总被引:1,自引:0,他引:1
Hitoshi Yamada Takashige Miyashita Masahiro Ohtani Kimihiro Nishio Hiroo Yonezu Yuzo Furukawa 《Optical Review》2002,9(1):1-8
We designed an integrated circuit for edge detection of a two-dimensional image based on the vertebrate outer retina, which has wide dynamic range in image processing. The unit circuit is simple, and operates as a current-mode analog metal-oxide-semiconductor (MOS) circuit. In order to extract edges from an image composed of bright and dark domains, the circuit realizes a function called local adaptation in which the sensitivity adapts to local brightness of the image. Simulation results, using the simulation program with integrated circuit emphasis (SPICE), of two-dimensional Gaussian-distributed images in which the intensity ranged over four orders of magnitude, showed the local adaptation. As a result, the intensity of output images was in the range of one order of magnitude. Furthermore, as the simulation result of real images, it was shown that edges in the dark domain, which was five times darker than the bright domain, were successfully detected as the bright domain in which input photocurrents ranged over two orders of magnitude. 相似文献
84.
We proposed in this research a novel two-dimensional network based on the frog visual system, with a motion detection function
and a newly developed simple-shape recognition function, for use in object discrimination by integrated circuits. Specifically,
the network mimics the signal processing of the small-field cell in a frog brain, consisting of the tectum and thalamus, which
generates signals of the motion and simple shape of an object. The proposed network is constructed from simple analog complementary
metal oxide semiconductor (CMOS) circuits; a test chip of the proposed network was fabricated with a 1.2 μm CMOS process.
Measurements on the chip clarified that the proposed network can generate signals of the moving direction, velocity, and simple
shape, as well as perform information processing of the small-field cell. Results with the simulation program with integrated
circuit emphasis (SPICE) showed that the analog circuits used in the network have low power consumption. Applications of the
proposed network are expected to realize advanced vision chips with functions such as object discrimination and target tracking. 相似文献
85.
Nakanishi I Nishizawa C Ohkubo K Takeshita K Suzuki KT Ozawa T Hecht SM Tanno M Sueyoshi S Miyata N Okuda H Fukuzumi S Ikota N Fukuhara K 《Organic & biomolecular chemistry》2005,3(18):3263-3265
Photoreduction of pyridine N-oxide, which has a key structure of antitumor agents for hypoxic solid tumors, by 1-benzyl-1,4-dihydronicotinamide in deaerated aprotic media resulted in generation of hydroxyl radical, leading to the oxidation of salicylic acid to 2,3- and 2,5-dihydroxybenzoic acids, and catechol. 相似文献
86.
An enolate-imine condensation using the lithium dianion of 3-hydroxy-butanoate and N-acylaldimines gave the key intermediate for the preparation of (+)-thienamycin with improved stereoselection in the presence of lithium chloride. 相似文献
87.
Ikuo Narisawa Masaru Ishikawa Hiroyuki Ogawa 《Journal of Polymer Science.Polymer Physics》1977,15(6):1055-1066
The micromechanism of the fatigue process in highly oriented nylon 6 fibers is discussed on the basis of changes in mechanical and structural properties during fatiguing. Experimental results show that the fatigue process can be divided into two stages. The characteristic features in the initial period are increases in breaking strength, long period, and molecular orientation, and a reduction in dye penetration. In the second period, after about 500 cycles, breaking strength and orientation decrease slightly, and the long period, permanent strain, and dye penetration increase with duration of fatiguing. It is demonstrated that the structural changes mainly occur in the amorphous regions of the fiber structure. The structural and mechanical changes in the initial period lead to the conclusion that the initial cyclic strain causes strain hardening caused by extended tie chains which do not rupture. A combination of load bearing by tie chains and sliding motion of the fibrillar elements can explain the progressive degradation of the fiber during the second stage of fatiguing. 相似文献
88.
Mitsuru Yoshioka Ikuo Kikkawa Teruji Tsuji Yasuhiro Nishitani Sachio Mori Kyo Okada Masayuki Murakami Fumihiko Matsubara Masaaki Yamaguchi Wataru Nagata 《Tetrahedron letters》1979,20(44):4287-4290
A intermediate was obtained by novel reductive cleavage of , prepared from in steps including a new ester to ketone conversion. Regioselective bromination of followed by substitution and known conversions gave 1-oxacephems . 相似文献
89.
Lipase (Pseudomonas sp.) was immobilized in collagen membrane and used for the measurement of neutral lipids. The determination system for lipids consisted of a lipase-collagen membrane reactor and glass electrodes. Neutral lipids were hydrolyzed to fatty acids and glycerol by immobilized lipase. The liberated protons were determined potentiometrically by using glass electrodes. A linear relationship was obtained between the logarithm of lipid concentrations and potential differences. The measurement gave results comparable to a conventional assay and was found to be applicable to the assay of neutral lipids in sera. The relative error of the determination by this system was within 4%. 相似文献
90.
Masaru Ishikawa Ikuo Narisawa Hiroyuki Ogawa 《Journal of Polymer Science.Polymer Physics》1977,15(10):1791-1804
Plastic deformation and crazes were initiated in polycarbonate bars containing a round notch by three-point bending. Morphological observations revealed that internal crazes are nucleated by a hydrostatic stress component caused by plastic constraint ahead of the fully developed plastic deformation zone. The characteristics of the deformation bands for quenched and slowly cooled materials are in good agreement with the logarithmic spiral curves predicted from a slip-line theory. The distribution of the stress components in the plastic deformation zone was analyzed using this theory. The critical hydrostatic stress is 87 MN/m2 for slowly cooled polycarbonate and 89 MN/m2 for quenched material. These results are compared with those of the craze nucleation models of Gent and Argon. 相似文献