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51.
In the theory of shape from shading, behaviours of the local solution around a critical point of the image play an important role. This paper shows that the second derivatives of the object surface can be locally determined at these image critical points. Closed form expressions of the surface second derivatives in terms of the second derivatives of the image brightness and of the reflectance map are shown. They are derived as follows: By differentiating the image irradiance equation twice at an image critical point, a set of polynomial equations is obtained that contains the second derivatives of the surface, of the image brightness and of the reflectance map. Regarding these equations as simultaneous equations for unknown surface second derivatives, they are algebraically solved and their explicit expressions are derived. Such a derivation is possible only at image critical points and is impossible at any other image point. The applicability of the derived expressions to noisy images is tested using synthetic images. 相似文献
52.
Straight-through microchannel devices for generating monodisperse emulsion droplets several microns in size 总被引:1,自引:1,他引:0
Isao Kobayashi Takayuki Takano Ryutaro Maeda Yoshihiro Wada Kunihiko Uemura Mitsutoshi Nakajima 《Microfluidics and nanofluidics》2008,4(3):167-177
The authors recently proposed a promising technique for producing monodisperse emulsions using a straight-through microchannel
(MC) device composed of an array of microfabricated oblong holes. This research developed new straight-through MC devices
with tens of thousands of oblong channels of several microns in size on a silicon-on-insulator plate, and investigated the
emulsification characteristics using the microfabricated straight-through MC devices. Monodisperse oil-in-water (O/W) and
W/O emulsions with average droplet diameters of 4.4–9.8 μm and coefficients of variation of less than 6% were stably produced
using surface-treated straight-through MC devices that included uniformly sized oblong channels with equivalent diameters
of 1.7–5.4 μm. The droplet size of the resultant emulsions depended greatly on the size of the preceding oblong channels.
The emulsification process using the straight-through MC devices developed in this research had very high apparent energy
efficiencies of 47–60%, defined as (actual energy input applied to droplet generation/theoretical minimum energy input necessary
for making droplets) × 100. Straight-through MC devices with numerous oblong microfluidic channels also have great potential
for increasing the productivity of monodisperse fine emulsions. 相似文献
53.
Hoshino O 《Neural computation》2007,19(2):351-370
Auditory communication signals such as monkey calls are complex FM vocal sounds and in general induce action potentials in different timing in the primary auditory cortex. Delay line scheme is one of the effective ways for detecting such neuronal timing. However, the scheme is not straightforwardly applicable if the time intervals of signals are beyond the latency time of delay lines. In fact, monkey calls are often expressed in longer time intervals (hundreds of milliseconds to seconds) and are beyond the latency times observed in the brain (less than several hundreds of milliseconds). Here, we propose a cochleotopic map similar to that in vision known as a retinotopic map. We show that information about monkey calls could be mapped on a cochleotopic cortical network as spatiotemporal firing patterns of neurons, which can then be decomposed into simple (linearly sweeping) FM components and integrated into unified percepts by higher cortical networks. We suggest that the spatiotemporal conversion of auditory information may be essential for developing the cochleotopic map, which could serve as the foundation for later processing, or monkey call identification by higher cortical areas. 相似文献
54.
Case learning for CBR-based collision avoidance systems 总被引:1,自引:1,他引:0
Yuhong Liu Chunsheng Yang Yubin Yang Fuhua Lin Xuanmin Du Takayuki Ito 《Applied Intelligence》2012,36(2):308-319
With the rapid development of case-based reasoning (CBR) techniques, CBR has been widely applied to real-world applications
such as collision avoidance systems. A successful CBR-based system relies on a high-quality case base, and a case creation
technique for generating such a case base is highly required. In this paper, we propose an automated case learning method
for CBR-based collision avoidance systems. Building on techniques from CBR and natural language processing, we developed a
methodology for learning cases from maritime affair records. After giving an overview on the developed systems, we present
the methodology and the experiments conducted in case creation and case evaluation. The experimental results demonstrated
the usefulness and applicability of the case learning approach for generating cases from the historic maritime affair records. 相似文献
55.
Several- Ni-Al and Ni-Al-Ti two-phase bicrystals were made by the solid-state diffusion couple method. Each couple consisted of a-phase single crystal and a pure-Ni polycrystal, and was annealed at 1473 K in an Ar gas atmosphere. Single crystal layers of-phase with uniform thickness always grow into the parent-phase single crystals. The resultant/ interface has no voids or facets regardless of the orientation of interface and the chemical composition of the-phase. Porosity formation due to the Kirkendall effect is observed in the diffused region. Concentration profiles exhibit nearly constant gradients in-phase. The orientation relationship between both phases is found to be 001//001, that is, the-phase grows epitaxially along the crystal orientation of-phase. 相似文献
56.
Yasuyuki Kaneno Tetsuo Yamaguchi Takayuki Takasugi 《Journal of Materials Science》2006,41(20):6871-6880
The texture evolution during the hot-rolling and the recrystallization of B2-type Fe–48Al, Ni–50Al and Co–50Ti (expressed
by at.%) intermetallic compounds were investigated. By hot-rolling at 973 K, Fe–48Al showed a microstructure with coarse grains
elongated along rolling direction, while Ni–50Al and Co–50Ti showed a deformed microstructure featured by the heavily distorted
(elongated) grains and/or the deformation bands. The hot-rolling texture of Fe–48Al was composed of {111}<uvw>, while those
of Ni–50Al and Co–50Ti were composed of {111}<110> and {111}<112>, respectively. After annealing, the recrystallized grains
were preferentially nucleated at the grain boundaries for Fe–48Al, and in the heavily distorted regions or the deformation
bands for Ni–50Al and Co–50Ti. The orientations of the recrystallized grains were similar with those of the deformed matrix,
especially for Ni–50Al and Co–50Ti. The recrystallization textures were generally more dispersive than the hot-rolling texture.
Based on these results, the texture evolution during the hot rolling and the recrystallization of the B2-type intermetallic
compounds were discussed. 相似文献
57.
Takayuki Iseki 《Vacuum》2006,80(7):662-666
A flat erosion-sputtering system has been developed using a rotating unbalanced and asymmetrical magnet. Target utilization and uniformity of erosion on the 5-in. target were greatly improved over the usual magnetron sputtering system by using a novel magnetron cathode to generate a wider, rotating magnetic flux. The novel magnetron cathode used the yoke magnet in which the stronger magnet set shifted towards the center and the weaker towards the periphery. This yoke magnet was attached to slant toward the center of rotation and rotated during sputtering. The estimated target utilization went up to 80% when the target was finally used up, and the uniformity of sputtered film was within 5% over an area 80 mm in diameter. 相似文献
58.
Hiroyuki Hirakata Yoshimasa Takahashi Shohei Matsumoto Takayuki Kitamura 《Engineering Fracture Mechanics》2006,73(17):2698-2709
In order to examine the mechanics of crack initiation at the free interface edge of a microcomponent on a substrate, delamination tests are carried out for two specimen shapes of Cr microdots on a SiO2 substrate. The microdots of the first specimen are shaped like the frustum of a round cone. The Cr microdots are successfully delaminated from the SiO2 substrate in a brittle manner and the critical load is measured by atomic force microscopy (AFM) with a lateral loading apparatus. Stress analysis reveals that a singular stress field exists near the interface edge and the strength for the crack initiation is governed by the intensified normal stress field. The critical stress intensity parameter is evaluated as KσC ≈ 0.24 MPa m0.39. Similar delamination tests are conducted for microdots shaped like the frustum of an oval cone. The stress distributions at the crack initiation of this specimen shape show a higher normal stress than the first specimen shape in the region near the interface edge of about x < 40 nm, while it is lower in the region of about x > 50 nm (x: distance from the edge). This suggests a limitation of conventional fracture mechanics: namely, the crack initiation in these specimens is not uniquely governed by the intensity of the singular field. It is found that the delamination crack is initiated when the averaged stress σya in the region of 90-130 nm reaches 190-270 MPa, regardless of the specimen shape. This indicates that the dominant stress region of crack initiation is roughly estimated as 90-130 nm and the criterion is given in terms of the averaged stress in the region. 相似文献
59.
Yoshihiro Takahashi Kenji Kitamura Yasuhiko Benino Takumi Fujiwara Takayuki Komatsu 《Materials Science and Engineering: B》2005,120(1-3):155-160
Flower-shaped crystals with diameters of 100–200 μm consisting of LaBGeO5 (LBGO) single crystals similar to petals were observed in the interior of transparent LBGO surface-crystallized glasses. Each flower-shaped crystal was radially grown from the surface of the included bubbles. A more intense second-harmonic generation was observed from the LBGO crystallized glasses with the flower-shaped LBGO single crystals compared to the samples without such crystals based on the Maker fringe technique and second-harmonic (SH) generation microscopy. The SH intensity for the flower-shaped LBGO single crystals monotonically decreased with increasing temperature up to 350 °C, less than the Curie temperature reported so far (530 °C). It is considered that the internal compressive stress induced by the difference in the thermal expansion between the LBGO single crystal and the corresponding glass affect the ferroelectric property of the flower-shaped LBGO single crystals in glass. 相似文献
60.
Yukio Tachibana Shigeaki Nakagawa Takeshi Takeda Akio Saikusa Takayuki Furusawa Kuniyoshi Takamatsu Kazuhiro Sawa Tatsuo Iyoku 《Nuclear Engineering and Design》2003,224(2):1010-197
Safety demonstration tests using the High Temperature Engineering Test Reactor (HTTR) will be conducted for the purpose of demonstrating inherent safety features of High Temperature Gas-cooled Reactors (HTGRs) as well as providing the core and plant transient data for validation of HTGR safety analysis codes. The first phase safety demonstration test items include the reactivity insertion test and the coolant flow reduction test. In the reactivity insertion test, which is the control rod withdrawal test, one pair out of 16 pairs of control rods is withdrawn, simulating a reactivity insertion event. The coolant flow reduction test consists of the partial loss of coolant flow test and the gas circulators trip test. In the partial loss of coolant flow test, primary coolant flow rate is slightly reduced by control system. In the gas circulators trip test one and two out of three gas circulators are run down, simulating coolant flow reduction events. The gas circulators trip tests, in which position of control rods are kept unchanged, are simulation tests of anticipated transients without scram (ATWS). 相似文献