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21.
K-means clustering is a very popular clustering technique, which is used in numerous applications. In the k-means clustering
algorithm, each point in the dataset is assigned to the nearest cluster by calculating the distances from each point to the
cluster centers. The computation of these distances is a very time-consuming task, particularly for large dataset and large
number of clusters. In order to achieve high performance, we need to reduce the number of the distance calculations for each
point efficiently. In this paper, we describe an FPGA implementation of k-means clustering for color images based on the filtering
algorithm. In our implementation, when calculating the distances for each point, clusters which are apparently not closer
to the point than other clusters are filtered out using kd-trees which are dynamically generated on the FPGA in each iteration
of k-means clustering. The performance of our system for 512 × 512 and 640 × 480 pixel images (24-bit full color RGB) is
more than 30 fps, and 20–30 fps for 756 × 512 pixel images in average when dividing to 256 clusters.
相似文献
Tsutomu Maruyama (Corresponding author)Email: |
22.
Tsutomu Furuzono Koji Seki Akio Kishida Taka-Aki Ohshige Kazunori Waki Ikuro Maruyama Mitsuru Akashi 《应用聚合物科学杂志》1996,59(7):1059-1065
Disiloxane–aromatic polyamide(aramid) multiblock copolymers(2SiPASs) were synthesized using 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane(BATS) as an analog of aramidsilicone resin consisting of aromatic polyamide and poly(dimethylsiloxane) (PDMS). 2SiPASs afford a transparent and toughened plastic film. The surface properties of 2SiPAS were investigated by X-ray photoelectron spectroscopy (xps) and static contact angle measurement. The results of surface analysis suggested that BATS content of the 2SiPAS surface increased with increasing BATS content in bulk. The interaction between the platelets and the 2SiPAS surface was found to be very weak when the BATS content reached 26 wt % in bulk. © 1996 John Wiley & Sons, Inc. 相似文献
23.
Jintong Li Kenichi Tachihara Kazukiyo Nagai Tsutomu Nakagawa Shichang Wang 《应用聚合物科学杂志》1996,60(10):1645-1654
Several sulfolanes such as 3-methylsulfolane, sulfolane, and 3-sulfolene were tested as modifiers in poly(trimethylsilyl methyl methacrylate) (PTMSMMA) and poly(trimethylsilyl propyne) (PMSP) to improve the selectivity of CO2. The gas permeabilities for the PTMSMMA-blend membranes containing high 3-methylsulfolane content were determined on a nonvacuum system in which the membranes started to be measured at their steady states at 30°C; those for all the other membranes were determined in a vacuum system in which those membranes were measured after they reached their unsteady states at 30°C. The PTMSMMA-blend membrane containing 40% 3-methylsulfolane was found to give the best separation of CO2 under the conditions in this study compared to all the PTMSMMA-blend membranes and the others prepared in our work; its ideal separation factors for CO2 over N2 were above 40 and its permeability coefficients of CO2 increased to above 250 Barrer. The modifications of PMSP membranes by impregnating with sulfolane and blending with sulfolene were found to be effective in improving the selectivity for CO2 over N2 for the PMSP membrane. The ideal separation factors for CO2 over N2 for the modified PMSP membranes impregnated with 30% sulfolane and blended with 25% 3-sulfolene were improved to above 10 and 13, respectively. © 1996 John Wiley & Sons, Inc. 相似文献
24.
Nylon-6 substrates were coated with SiO2-RSiO3/2 (R = methyl, vinyl, phenyl) thin films by the sol-gel method, and their water permeability was evaluated Tetraethoxysilane (TEOS) and trifunctional alkoxides such as methyltriethoxysilane (MTES), vinyltriethoxysilane (VTES), and phenyltriethoxysilane (PhTES) were used as starting materials. Water permeability coefficients of the nylon-6 substrates coated with these SiO2-RSiO3/2 thin films were increased with an increase in the content of these trialkoxysilanes in the films. The water permeability coefficients of these coated nylon-6 substrates were smaller in the order of the systems TEOS-PhTES < TEOS-VTES < TEOS-MTES in the relatively low content of the trialkoxysilanes. © 1996 John Wiley & Sons, Inc. 相似文献
25.
Doudou Diagne Motonobu Goto Tsutomu Hirose 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1996,65(1):29-38
The simultaneous removal and concentration of carbon dioxide present in ambient air were carried out by a dual refluxed Pressure Swing Adsorption (PSA) process with intermediate feed inlet position. The feed inlet position divides each column into rectifying and stripping sections from which enriched and lean gases can be simultaneously produced. A simple isothermal model with negligible axial dispersion and pressure drops through the PSA beds was developed to investigate the effects of various combinations of the operating variables and to analyze semi-quantitatively the effects of the main characteristic parameters such as the dimensionless feed inlet position (ZR/LT) and the stripping-reflux ratio (Rr). A good agreement between the model prediction and the experimental results was obtained. Moreover, an optimum feed inlet position was found and it corresponded to a position where the carbon dioxide mole ratio in the feed flux and that in the upstream flux leaving the stripping section were equal. The carbon dioxide mole ratio in the enriched product (YE) as well as that in the lean product (YL) were strongly dependent on the ratio of feed/enriched product flow rates (QF/QE) and the ratio of feed/lean product flow rates (QF/QL). Although the pressure ratio (Pa/Pd) was crucially important for the separation performance, a smaller value of Rr was sufficient to reach a performance which is unattainable in conventional PSA processes. 相似文献
26.
Sachiko Kaidzu Tsutomu Okuno Masaki Tanito Akihiro Ohira 《International journal of molecular sciences》2022,23(1)
The effects of visible light, from short to long wavelengths, on the retina were investigated functionally and histologically. The left eyes of Sprague–Dawley albino rats (6-weeks old, n = 6 for each wavelength) were exposed to seven narrow-band wavelengths (central wavelengths, 421, 441, 459, 501, 541, 581, and 615 nm) with bandwidths of 16 to 29 nm (half bandwidth, ±8–14.5 nm) using a xenon lamp source with bandpass filters at the retinal radiant exposures of 340 and 680 J/cm2. The right unexposed eyes served as controls. Seven days after exposure, flash electroretinograms (ERGs) were recorded, and the outer nuclear layer (ONL) thickness was measured. Compared to the unexposed eyes, significant reductions in the a- and b-wave ERG amplitudes were seen in eyes exposed to 460-nm or shorter wavelengths of light. The ONL thickness near the optic nerve head also tended to decrease with exposure to shorter wavelengths. The decreased ERG amplitudes and ONL thicknesses were most prominent in eyes exposed to 420-nm light at both radiant exposures. When the wavelengths were the same, the higher the amount of radiant exposure and the stronger the damage. Compared to the unexposed eyes, the a- and b-waves did not decrease significantly in eyes exposed to 500-nm or longer wavelength light. The results indicate that the retinal damage induced by visible light observed in albino rats depends on the wavelength and energy level of the exposed light. 相似文献
27.
Yan Wu Daisuke Tozawa Tatsuya Ito Tsutomu Tada Keitaro Hitomi 《Journal of Nuclear Science and Technology》2013,50(3):320-327
A crown ether loaded resin was prepared by successive impregnation and fixing the 4′,4′(5″)-di(tert-butylcyclohexano)-18-crown-6 (DtBuCH18C6) and its molecule modifier, 1-dodecanol, onto the porous silica/polymer composite support (SiO2-P particles). The characterization of DtBuCH18C6 loaded resin was examined by thermal gravimetry and differential thermal analysis and electron probe microanalysis. The adsorption behavior of Sr(II), Cs(I), Ru(III), Pd(II), La(III), Nd(III), Sm(III), Gd(III), Zr(IV), and Mo(VI) was investigated by the batch method. Furthermore, the column test for Sr (II) was performed. The batch experiments were carried out by varying the shaking times, HNO3 concentration, and initial concentration of metal ions. A relatively large K d value above 182 cm3/g for Sr(II) was obtained in the presence of 3 M HNO3. In contrast, the K d values of Cs(I), Ru(III), Pd(II), La(III), Nd(III), Sm(III), Gd(III), Zr(IV), and Mo(VI) were considerably lower than 10 cm3/g. The adsorption of Sr(II) was found to be controlled by chemisorption mechanism, and followed a Langmuir-type adsorption equation. The breakthrough curve of Sr(II) had S-shaped profile, and the elution percentage was estimated to be 99.9% by using the eluent of H2O. 相似文献
28.
A generation method of artificial fluctuation data of wind power output considering smoothing effect
To use realistic wind power fluctuation data is important in simulating frequency change of power systems. It is well known that the smoothing effect must be taken into account when generating the artificial wind power output. Therefore, this paper proposed a new method to generate fluctuation waveform considering smoothing effect based on random number to fulfill the correlation among multiple sites and autoregression model. The effectiveness of the proposed method was tested by using practical wind speed data measured in Tohoku district. 相似文献
29.
Ano A Takayanagi T Uchibori T Okuda T Yokotsuka K 《Journal of Bioscience and Bioengineering》2003,95(6):645-647
A chitinase gene (Chi3K) was cloned from the genomic DNA of Vitis vinifera cv. Koshu. The structural gene comprised 891 by without introns and encoded 297 amino acids. The Chi3K product showed high similarity to the class III chitinase of V. vinifera cv. Pinot noir. Chi3K was expressed using a bacterial expression vector for purification and enzymatic characterization of its gene product. The recombinant chitinase exhibited hydrolytic activity toward glycol chitin and its optimum pH was 4.0. It also inhibited the growth of Botrytis cinerea, which causes grey mold disease in grapes. 相似文献
30.
Evaluation of a nitric acid-based partial-digestion method for selective determination of inorganic arsenic in rice 总被引:1,自引:0,他引:1
Hamano-Nagaoka M Nishimura T Matsuda R Maitani T 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2008,49(2):95-99
Arsenic (As) uptake in human occurs via the food chain mainly. The Joint FAO/WHO Expert Committee on Food Additives has established the provisional tolerable weekly intake level for As as an inorganic As (iAs) value, because iAs in food is much more toxic than organic As. In this study, we studied an acid based partial-digestion method for the complete extraction of arsenicals from rice. HPLC/ICP-MS was used to determine the concentration of iAs selectively. The conditions adopted to extract arsenicals from a 0.5 g of finely ground rice sample were addition of 2 mL of 0.15 mol/L nitric acid and heating at 80 degrees C for 2 hr. The LOD and LOQ for iAs were 0.0024 and 0.0079 mg/kg dry weight, respectively. Recovery studies showed good accuracy. When the method was applied to ten short-grain brown rice samples, the iAs concentrations were 0.108-0.227 mg/kg dry weight and the total As concentrations were 0.118-0.260 mg/kg dry weight. Although dimethylarsinic acid was also detected in most samples, the percentage of iAs content in total As content was 62.2-96.3%. Thus, iAs was the principal As species in the short-grain brown rice samples tested. 相似文献