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91.
We propose a new method for enhancing the sensitivity of the reflectance spectrum to the scattering feature of the superficial tissue layer. This method is based on multiple-discriminant analysis in the eigensubspace of the spectrum. Considering the application of scattering imaging, we evaluated this method by performing multispectral imaging of two-layered tissue phantoms. A color map converted from the spectral reflectance corresponds well to variations in the size of the scattering in the first layer. 相似文献
92.
Development of a numerical wave tank for analysis of nonlinear and irregular wave field 总被引:9,自引:0,他引:9
A numerical wave-absorption filter has been developed for an open boundary condition in the analysis of nonlinear and irregular wave evolution. The filter is composed of a simulated sponge layer and Sommerfeld's radiation condition at the outer edge of the layer. The wave-absorption characteristics of the filter have been investigated by applying the linear potential theory and a two-dimensional nonlinear boundary element model. In both cases, the filter is found to he applicable for a wide range of wave parameters. In order to realize an idealized “numerical wave tank”, the present model also incorporates a nonreflective wave generator in the computational domain composed of a series of vertically aligned point sources. Numerous numerical experiments demonstrate that the present approach is effective in generating an arbitrary wave profile without reflection not only at the open boundaries but also at the wave generator. 相似文献
93.
Xiaoyan Hou Nikolaos Kaplaneris Binbin Yuan Johanna Frey Tsuyoshi Ohyama Antonis M. Messinis Lutz Ackermann 《Chemical science》2022,13(12):3461
Ruthenaelectro(ii/iv)-catalyzed intermolecular C–H acyloxylations of phenols have been developed by guidance of experimental, CV and computational insights. The use of electricity bypassed the need for stoichiometric chemical oxidants. The sustainable electrocatalysis strategy was characterized by ample scope, and its unique robustness enabled the late-stage C–H diversification of tyrosine-derived peptides.Ruthenaelectro(ii/iv)-catalyzed intermolecular C–H acyloxylations of oligopeptides have been developed by the guidance of key experimental, CV and computational insights. 相似文献
94.
Kaname Ohyama Yuki Fukahori Kenichiro Nakashima Tomoyuki Sueyoshi Naoya Kishikawa Naotaka Kuroda 《Journal of chromatography. A》2010,1217(9):1501-1505
An adamantyl (ADM)-functionalized monolithic stationary phase was newly synthesized by a single-step copolymerization of 1-adamantyl-(α-trifluoromethyl) acrylate, ethylene dimethacrylate, and 2-acrylamido-2-methyl-1-propanesulfonic acid in order to prevent the peak tailing of basic solutes in capillary electrochromatography and was compared with butyl methacrylate (BMA)-based one. The ADM structure shields the negatively charged groups on the surface of monolith from basic solutes, resulting in better peak shapes than BMA-based monolithic stationary phase. As the monomers ratio decreased, the monolithic column had lower retention and higher column efficiency which was likely due to lower phase ratio and smaller globule size of monolith, respectively. The ADM-functionalized monolithic columns exhibited a good repeatability and reproducibility of column preparation with relative standard deviation values below 9% in the studied chromatographic parameters. 相似文献
95.
Mitsuyoshi Tashiro Yuri Murakami Takashi Obi Masahiro Yamaguchi Nagaaki Ohyama 《Optical Review》2011,18(6):462-469
This paper presents multispectral image coding methods based on visible component separation techniques. By coding the visible
components separately from other spectral components, the color information can be used without decoding the whole multispectral
image. Two types of separation techniques are introduced: one is a direct separation of visible and invisible layers, while
the other is a scalable separation. In the scalable separation, visible components are first compressed to produce the base
layer bitstream. The enhancement layer data include not only invisible components but also the information on the distortion
of the coded visible components. Such a separation technique improves the accuracy of decoded multispectral images especially
when visible components are highly compressed. The performance of the proposed methods was evaluated for different bit allocations
to visible components. In general, the coding performance reduces when data are divided and coded separately to incorporate
scalabilities. Nonetheless, it is found that the proposed scalable approach realizes a peak signal-to-noise ratio PSNR value
comparable to that achieved by employing JPEG2000, which incorporates no scalability. 相似文献
96.
Jose Javier Baez-Rojas Masahiro Yamaguchi Takashi Obi Nagaaki Ohyama 《Optical Review》1997,4(4):471-475
Volume data is interpolated using pseudo color and an electro-optical-hybrid-system. The method proposed in this paper is called optical interpolation. The visualization of a volumetric array of computed tomography data is achieved using the optical interpolation technique in combination with the optical model and the electro-optical-hybrid-system. To show the advantages of optical interpolation, the results are compared with those obtained by the traditional technique. 相似文献
97.
Non-intrusive two-phase fluid pumping based on an electrohydrodynamically (EHD) induced flow phenomenon with free liquid surface
exposed to gas-phase corona discharges is experimentally investigated. Dielectric liquid flow generated near a corona discharge
electrode progresses toward an inclined plate electrode, and then climbs up the surface against the gravitational force for
an air-wave (AW) type EHD pump. The AW type EHD pump is operated on ionic wind field along the inclined plate electrode. The
pumping performance of time-averaged liquid flow rate and the liquid-phase flow motion are characterized. The liquid flow
characteristics related to a dimensionless parameter of corona discharge fields are presented. 相似文献
98.
Shin-ichiroh Kitoh Hiroki Tokuoka Jun Hasegawa Tetsuo Nonami Takashi Obi Masahiro Yamaguchi Nagaaki Ohyama 《Optical Review》1998,5(6):352-357
In endoscopic diagnosis, there has been a strong requirement to measure the internal surface topography of the rectum or esophagus. Accurate measurement, however, is very difficult, because the object is usually observed from an inclined view. In this paper, we propose a method to overcome this difficulty utilizing sequential stereo-pair images; the relative shape is roughly measured from sequential images taken by one of the change coupled device (CCD) cameras, and the size is determined by stereo-pair matching using the measured shape. A coarse-to-fine approach is also used to improve the resolution of topographic measurement. Through a basic experiment using a monocular CCD endoscope and a polyp phantom, the proposed method is confirmed to improve measurement accuracy in comparison with conventional methods. 相似文献
99.
Ohyama K Suzuki M Masuda K Yoshida S Muranaka T 《Chemical & pharmaceutical bulletin》2007,55(10):1518-1521
Plants produce a wide variety of cyclic triterpenes, such as sterols and triterpenoids, which are the major products of the mevalonate (MVA) pathway. It is important to understand the physiological functions of HMG-CoA reductase (HMGR) because HMGR is the rate-limiting enzyme in the MVA pathway. We have previously isolated Arabidopsis mutants in HMG1 and HMG2. Although the biochemical function of HMGR2 has been thought to be almost equal to that of HMGR1, based on similarities in their sequences, the phenotypes of mutants in these genes are quite different. Whereas hmg2 shows no abnormal phenotype under normal growth conditions, hmg1 shows pleiotropic phenotypes, including dwarfing, early senescence, and male sterility. We previously postulated that the 50% decrease in the sterol content of hmg1, as compared to that in the wild type, was a cause of these phenotypes, but comprehensive triterpene profiles of these mutants had not yet been determined. Here, we present the triterpene profiles of hmg1 and hmg2. In contrast to hmg1, hmg2 showed a sterol content 15% lower than that of the wild type. A precise triterpenoid quantification using synthesized deuterated compounds of beta-amyrin (1), alpha-amyrin (2), and lupeol (3) showed that the levels of triterpenoids in hmg1 and hmg2 were 65% and 25% lower than in the wild type (WT), respectively. These results demonstrate that HMGR2 as well as HMGR1 is responsible for the biosynthesis of triterpenes in spite of the lack of visible phenotypes in hmg2. 相似文献
100.
T. Hakata H. Ohyama E. Simoen C. Claeys K. Miyahara K. Kawamura Y. Ogita Y. Takami 《Journal of Radioanalytical and Nuclear Chemistry》1999,239(2):357-360
Results are presented of a study on the degradation and recovery of the electrical performance of MOSFETs processed on SIMOX
substrates, subjected to 1 and 2 MeV electron and to 20 MeV alpha-ray irradiations. The damage coefficient for alpha-ray irradiation
is about three orders of magnitude larger than the one for electron irradiation, which is attributed to the difference of
incident particle mass and the possibility of nuclear collision during radiation damage. 相似文献