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61.
James Charles Tomas Pfister Mark Everingham Andrew Zisserman 《International Journal of Computer Vision》2014,110(1):70-90
We present a fully automatic arm and hand tracker that detects joint positions over continuous sign language video sequences of more than an hour in length. To achieve this, we make contributions in four areas: (i) we show that the overlaid signer can be separated from the background TV broadcast using co-segmentation over all frames with a layered model; (ii) we show that joint positions (shoulders, elbows, wrists) can be predicted per-frame using a random forest regressor given only this segmentation and a colour model; (iii) we show that the random forest can be trained from an existing semi-automatic, but computationally expensive, tracker; and, (iv) introduce an evaluator to assess whether the predicted joint positions are correct for each frame. The method is applied to 20 signing footage videos with changing background, challenging imaging conditions, and for different signers. Our framework outperforms the state-of-the-art long term tracker by Buehler et al. (International Journal of Computer Vision 95:180–197, 2011), does not require the manual annotation of that work, and, after automatic initialisation, performs tracking in real-time. We also achieve superior joint localisation results to those obtained using the pose estimation method of Yang and Ramanan (Proceedings of the IEEE conference on computer vision and pattern recognition, 2011). 相似文献
62.
Frank C. Magne James A. Harris Robert A. Pittman Evald L. Skau 《Journal of the American Oil Chemists' Society》1966,43(9):519-524
The stepwise HBr titration method for the cyclopropenoid analysis of cottonseed oils is subject to serious inaccuracies when
applied to samples containing higher cyclopropenoid concentrations, particularly if they contain appreciable amounts of alumina-adsorbable
materials. A modification of the method is described which eliminates these sources of error. Its validity has been established
by the analysis of a wide range of synthetic compositions including compositions containing massive amounts of interfering
HBr-reactive substances and other alumina-adsorbable materials. The method with further modification can be used to analyze
glycerides with the same high degree of accuracy.
Presented at the AOCS Meeting in Houston, April 1965.
So. Utiliz. Res. Dev. Div., ARS, USDA. 相似文献
63.
An isothermal model for hydrodemetallation (HDM) of crude oils in catalytic fixed-bed reactors is proposed. This model involves a consecutive reaction mechanism, which is capable of accounting for particle deposit profiles with interior maxima. Consistent with the fact that HDM catalysts are conglomerates formed by precipitation, the porous catalyst itself is modeled as randomly overlapping spheres of equal size. The metal is deposited as growing metal sulfide crystallites on the inner surface of the catalyst. These crystallites originate from a certain number of randomly scattered nuclei and increase in size as the deposition proceeds. The random sphere model for the catalyst and the deposit provides the changes in the catalyst pore structure—local porosity and surface area.
The mass transport within the domain of the particle is due to restricted liquid diffusion, since the diameter of the metal bearing compound (porphyrin) and the intermediate are comparable to the pore size. The diffusion restrictions taken into account are the enhanced drag imposed on a molecule by adjacent pore walls and steric partitioning.
Since the deposition process is much slower than diffusion and reaction, the pseudo-steady-state assumption can be justified. The equations of conservation for mass are solved by orthogonal collocation on finite elements. Based on this solution technique a computer simulation program of HDM is designed that allows two modes of operation: constant temperature and constant conversion. The simulation program “SIMULA” is highly flexible with regard to reaction kinetics, catalyst structure, reactor design, and operating conditions. In comparison to a base case with uniform activity, the effect of intraparticle (radial) and bed (axial) activity profiles on the conversion rate is discussed. For the case investigated, a radial distribution of activity higher at the center of the particle than at the edge can increase catalyst life by 25%, but axial distribution was less successful. 相似文献
The mass transport within the domain of the particle is due to restricted liquid diffusion, since the diameter of the metal bearing compound (porphyrin) and the intermediate are comparable to the pore size. The diffusion restrictions taken into account are the enhanced drag imposed on a molecule by adjacent pore walls and steric partitioning.
Since the deposition process is much slower than diffusion and reaction, the pseudo-steady-state assumption can be justified. The equations of conservation for mass are solved by orthogonal collocation on finite elements. Based on this solution technique a computer simulation program of HDM is designed that allows two modes of operation: constant temperature and constant conversion. The simulation program “SIMULA” is highly flexible with regard to reaction kinetics, catalyst structure, reactor design, and operating conditions. In comparison to a base case with uniform activity, the effect of intraparticle (radial) and bed (axial) activity profiles on the conversion rate is discussed. For the case investigated, a radial distribution of activity higher at the center of the particle than at the edge can increase catalyst life by 25%, but axial distribution was less successful. 相似文献
64.
Youren Xu Avigdor Zangvil Jonathan Lipowitz James A. Rabe Gregg A. Zank 《Journal of the American Ceramic Society》1993,76(12):3034-3040
Stoichiometric and near-stoichiometric silicon carbide fibers, derived from the polymer polycarbosilane, have been characterized by scanning Auger and transmission electron microscope techniques. Excess carbon usually appeared in the fibers, but it could be eliminated by controlling processing conditions. The fibers consisted mainly of submicrometer-sized SiC microcrystals, with a considerably twinned and stacking-faulted β-SiC structure. Free carbon, which appeared in the form of graphite, was the only detectable intergranular phase in the nonstoichioinetric SiC fibers, while the stoichiometric SiC fibers contained no detectable second phase whatsoever. 相似文献
65.
Chlorination of a low molecular weight polystyrene in the α position was studied by following changes in the infrared spectrum, glass transition temperature, and molecular weights of the polymer. The logarithm of the absorbance ratio at 2920 and 1500 cm?1 as a function of mole per cent chlorination was linear. The glass transition temperatures, determined by use of a differential scanning calorimeter (DSC), were found to obey an equation developed by Dyvik for copolymers. The molecular weight of the chlorinated polystyrene decreased as a function of chlorination. 相似文献
66.
James W. Gentry 《加拿大化工杂志》1970,48(4):451-455
A new method for the numerical solution of a stagewise process is presented. The method consists of total linearization of all the equations in the distillation process, using the method of quasi-linearization. The resulting equations form a block-band matrix which can be readily solved by a method developed by the author. The method used for obtaining convergence is presented. The method has been tested for both binary and multi-component systems. The method has been compared with the Amundson-Pontinen method for a five component mixture. The method gives more rapid convergence. Numerical experiments indicate that the vapor and liquid flow rates are more stringent requirements than the bubble point. 相似文献
67.
Protein, total phospholipid, phosphatidyl cholines and phosphatidyl choline fractions from liver mitochondria and microsomes
of female rats were analyzed after treatment with CCl4 (0.3 ml of CCl4 suspended in corn oil) or ethionine (50 mg in 0.9% saline) or after feeding a choline deficient, low protein diet for seven
days. Phosphatidyl cholines were separated into four fractions differing in the degree of fatty acid unsaturation. Over 50%
of total phosphatidyl choline phosphorus was present in fraction 3 of liver mitochondria and microsomes. The major fatty acid
in fraction 1 was docosahexaenoic acid. Fraction 4 contains oleic and linoleic acids. Arachidonic acid occurs in fraction
2 and 3. Ethionine decreased the amount of microsomal protein and phosphatidyl choline fraction 1 of mitochondria. Microsomal
protein was decreased by CCl4. The choline deficient, low protein diet caused a decrease in mitochondrial and microsomal phospholipids. The amount of the
mitochondrial phosphatidyl choline decreased. Corn oil increased the level of phosphatidyl choline fraction 3. Choline deficiency
decreased the amount of phosphatidyl choline fraction 3, increased fraction 4 of mitochondria and microsomes and increased
fraction 1 of microsomes. 相似文献
68.
Alan P. Kozikowski Xue-Min Cheng Chun-Sing Li James G. Scripko 《Israel journal of chemistry》1986,27(1):61-65
A new synthesis of 4- and 7-carbon-substituted indoles is described. The overall sequence involves the addition of a nitrile oxide to 1 carboethoxy-2-(or 3-) allylpyrrole, hydrogenation of the intermediate isoxazoline to β-hydroxy ketone and cyclization of the ketol using magnesium or zinc triflate to the substituted indole. This new indole-forming strategy can also accommodate the introduction of oxygen functionality into the indole 6-position. Possible mechanistic aspects of the reaction are detailed. 相似文献
69.
Transformation-range viscosity and thermal expansion measurements were made for five series (Li-Na, Li-K, Li-Cs, Na-Cs, and K-Rb) of mixed-alkali borate glasses containing 30 mol% total alkali oxide. In each case, negative deviations from additivity were observed in the isokom and glass transformation temperatures. Positive deviations from additivity were observed in the thermal expansion coefficients for the Li-Na, Li-K, and K-Rb glasses, while the Li-Cs and Na-Cs glasses exhibited negative deviations. Maximization of the deviation from additivity in the viscosity and glass transformation temperatures occurred when the radius ratio of the two alkali ions was approximately 1.7 to 1.8. Combination of the results of this study with those of earlier studies indicates that the deviations from additivity observed for these properties are independent of the identity of the glass former. 相似文献
70.
The surface activity of spent sulphite liquor (SSL) and the separation of surface active components by foam fractionation were studied. The maximum activity (lowest surface tension) of SSL was observed at a high pH. The surface tension was found to be 42 mN/m and 38 mN/m at acidic and basic pH values, respectively, and also a maximum foaminess (Σ) of 7 min was observed at pH 10. Foam fractionation reduced the surfactant concentration by 90% at an optimum pH of 10. The surfactants were concentrated in the collapsed foam as shown by the fact that the critical micelle concentrations of the unfractionated SSL and foam were 70% (v/v) and 10% (v/v), respectively. The removed surfactants were concentrated in 20% of the original liquid volume. 相似文献