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91.
Rational Filters for Passive Depth from Defocus 总被引:9,自引:0,他引:9
A fundamental problem in depth from defocus is the measurement of relative defocus between images. The performance of previously proposed focus operators are inevitably sensitive to the frequency spectra of local scene textures. As a result, focus operators such as the Laplacian of Gaussian result in poor depth estimates. An alternative is to use large filter banks that densely sample the frequency space. Though this approach can result in better depth accuracy, it sacrifices the computational efficiency that depth from defocus offers over stereo and structure from motion. We propose a class of broadband operators that, when used together, provide invariance to scene texture and produce accurate and dense depth maps. Since the operators are broadband, a small number of them are sufficient for depth estimation of scenes with complex textural properties. In addition, a depth confidence measure is derived that can be computed from the outputs of the operators. This confidence measure permits further refinement of computed depth maps. Experiments are conducted on both synthetic and real scenes to evaluate the performance of the proposed operators. The depth detection gain error is less than 1%, irrespective of texture frequency. Depth accuracy is found to be 0.51.2% of the distance of the object from the imaging optics. 相似文献
92.
93.
Koichi Hasegawa Hideki Nishimori Masahiro Tatsumisago Tsutomu Minami 《Journal of Materials Science》1998,33(4):1095-1098
Thick silica films were prepared by the electrophoretic sol–gel deposition technique in the presence of poly(acrylic acid) (PAA) using monodispersed silica particles; the particles were prepared by the sol–gel method, pre-heat treated and then re-dispersed in the mixture of H2O and ethanol. The weight of deposited silica films was maximized when 0.2 mass % of PAA against the whole amount of sol was added. The particles constructing the thick silica films were packed densely when the amount of added PAA was less than 0.2 mass%. The weight of the film increased with decrease in the content of H2O in the sol when a fixed amount of PAA was added. After the heat treatment of deposited films at 800 °C, crack-free silica films of about 30 m thickness were prepared. © 1998 Chapman & Hall 相似文献
94.
Takayuki Goto Takao Watanabe Kyoichi Kinoshita Azusa Matsuda Masafumi Sera Tetsuo Fukase 《Journal of Low Temperature Physics》1996,105(3-4):401-406
Cu-NMR spectra and the nuclear spin-lattice relaxation rate T
1
-1
have been studied intensively on the bilayer type high-Tc cuprate La1.89Ca1.11Cu2O6+ (La2126). The resonance line shift showed a monotonic decrease with lowering temperature in the normal state, indicating that this compound belongs to the lightly-doped region. The Curie-Weiss temperature dependence of (T1T)–1 in the normal state shows that the pseudo spin-gap does not always exist in the light-doped bilayer systems. 相似文献
95.
Masahiro Kitada Kazuhiro Yamamoto 《Journal of Materials Science: Materials in Electronics》1996,7(6):447-449
The effects of Ta addition on the magnetic properties of permalloy thin films have been investigated. The alloy compositions on a weight basis are (Ni81Fe19)1-x
Ta
x
with 0 x 0.105, and the films are sputtered onto a glass substrate at between room temperature and 300 C. The saturation magnetization and anisotropic magnetic field decrease with increasing Ta content. The saturation magnetization is 0.75 T at 5 wt % Ta. The coercivity remains constant at 125 Am-1. The electrical resistivity increases linearly with increasing Ta content, then saturates at approximately 7.5 wt% Ta. The saturation resistivity is approximately 1.00 m. The magnetoresistivity ratio (/) decreases with increasing Ta content, mainly due to increased electrical resistivity (). The magnetostriction changes from negative to positive with increasing Ta content and reaches nearly zero at 2 wt% Ta. The NiFeTa films containing 5–6 wt% Ta have potential for use as the soft-biasing film in magnetoresistive elements. 相似文献
96.
S Nakamura S Shibata K Shirota K Abe K Uetsuka H Nakayama N Goto K Doi 《Canadian Metallurgical Quarterly》1996,33(6):696-699
Renal glomerular fibrosis was observed in a 1-year-old spayed female Japanese domestic cat that showed clinically advanced renal failure. In the glomeruli, increased homogeneous materials were stained strongly with aniline blue by Masson's trichrome and positive for anti-type III collagen antibody by immunohistochemical staining, causing mesangial sclerosis and capillary collapse. By electron microscopy, randomly arranged fibrils were observed in the expanded subendothelial and mesangial areas, and the fibrils showed periodicity characteristic of collagen fibers in longitudinal sections. These findings of glomerular lesions closely resemble those of human "collagenofibrotic glomerulonephropathy," which has recently been described as a new type of glomerulonephropathy. 相似文献
97.
Yusuke Fukui Yosuke Honda Yasuhiro Yamauchi Michiko Okafuji Masahiro Sakai Mikihiko Nishitani Yusuke Takata 《Journal of the Society for Information Display》2010,18(12):1090-1094
Abstract— MgO thin film is currently used as a surface protective layer for dielectric materials because MgO has a high resistance during ion sputtering and exhibits effective secondary electron emission. The secondary‐electron‐emission coefficient γ of MgO is high for Ne ions; however, it is low for Xe ions. The Xe content of the discharge gas of PDPs needs to be raised in order to increase the luminous efficiency. Thus, the development of high‐γ materials replacing MgO is required. The discharge properties and chemical surface stability of SrO containing Zr (SrZrO) as the candidate high‐γ protective layer for noble PDPs have been characterized. SrZrO films have superior chemical stability, especially the resistance to carbonation because of the existence of a few adsorption sites due to their amorphous structure. The firing voltage is 60 V lower than that of MgO films for a discharge gas of Ne/Xe = 85/15 at 60 kPa. 相似文献
98.
Fujihara H. Goto M. Kitahara T. Okuno H. G. 《IEEE transactions on audio, speech, and language processing》2010,18(3):638-648
99.
This paper deals with a motion control system for a space robot with a manipulator. Many motion controllers require the positions of the robot body and the manipulator hand with respect to an inertial coordinate system. In order to measure them, a visual sensor using a camera is frequently used. However, there are two difficulties in measuring them by means of a camera. The first one is that a camera is mounted on the robot body, and hence it is difficult to directly measure the position of the robot body by means of it. The second one is that the sampling period of a vision system with a general-purpose camera is much longer than that of a general servo system. In this paper, we develop an adaptive state observer that overcomes the two difficulties. In order to investigate its performance, we design a motion control system that is constructed by combining the observer with a PD control input, and then conduct numerical simulations for the control system. Simulation results demonstrate the effectiveness of the proposed observer. 相似文献
100.
Tajima K Orisaka M Yata H Goto K Hosokawa K Kotsuji F 《Microscopy research and technique》2006,69(6):450-458
We developed a culture system in which two types of ovarian follicular cells were allowed to attach to opposite sides of a collagen membrane. Using this in vitro cell culture system, we studied the effects of granulosa- and theca-cell interaction on the morphology, structure, and function of bovine ovarian follicular cells. In the first part of the study, we explored how the interaction between theca and granulosa cells affects the morphology and structure of the cells. This study was done using follicular cells collected from bovine ovarian follicles at the early developmental stage. Granulosa cells cultured alone were flattened, and formed a monolayer sheet. By contrast, granulosa cells cultured with theca cells were convex, and formed multilayer sheets. Theca cells cultured alone were thin, flat, and spindle-shaped. Theca cells cultured with granulosa cells were also spindle-shaped; however, they appeared convex and more densely packed when compared with theca cells cultured alone. In the second part of the study, the possible role of the cellular interaction in the control of differentiation and growth of granulosa and theca cells was investigated. When follicular cells were isolated from the early stage of follicular development, theca cells reduced progesterone and inhibin production by granulosa cells and augmented the growth of granulosa cells. When the cells were isolated from the late stage of follicular development, by contrast, theca cells augmented hormonal production by granulosa cells, and did not affect the growth of granulosa cells. The growth and androstenedione production by theca cells were increased by the presence of granulosa cells, irrespective of the origin of follicular cells. These results demonstrated that communication between two types of follicular cells results in reciprocal modulation of their morphology, structure, growth, and function. Cellular interactions seem to be one of the major factors controlling the differentiation and growth of the follicular cells during the follicular maturation process. In contrast to granulosa and theca cells cultured alone, cells in the coculture seemed to possess morphological and functional characteristics more similar to those of cells in the growing follicular wall in vivo. Thus, we speculate that the interaction between these two types of follicular cells is essential for the maintenance of original structure and function of the bovine follicular wall. 相似文献