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排序方式: 共有622条查询结果,搜索用时 15 毫秒
1.
In this paper we focus on appearance features particularly the Local Binary Patterns describing the manual component of Sign Language. We compare the performance of these features with geometric moments describing the trajectory and shape of hands. Since the non-manual component is also very important for sign recognition we localize facial landmarks via Active Shape Model combined with Landmark detector that increases the robustness of model fitting. We test the recognition performance of individual features and their combinations on a database consisting of 11 signers and 23 signs with several repetitions. Local Binary Patterns outperform the geometric moments. When the features are combined we achieve a recognition rate up to 99.75% for signer dependent tests and 57.54% for signer independent tests. 相似文献
2.
Summary The dynamic mechanical behaviour of 4% aqueous solutions and networks of poly (N, N-diethylacrylamide) and copolymers of diethylacrylamide
with sodium methacrylate (MNa) (molar ratio xMNA=0–0.05) swollen in water was measured in the temperature range 20–80 °C. With increasing temperature, at Tc polymer chains collapse from random coil to more compact globular conformations. While in the region of coil conformations
(T > Tc) the mechanical behaviour of solutions has a liquid-like character (the loss modulus G″ is higher than the storage modulus
G′ for a constant frequency ω=1 Hz), in the region of globular conformations (T > Tc) a heterogeneous physical network is built in solutions, and the mechanical behaviour has a solid-like character (G′ > G″).
In networks the collapse is reflected in an increase of storage modulus G′; the magnitude of this increase decreases with
ionization. The dependence of the loss modulus G″ on the temperature of solutions and networks allows us to conclude that
the magnitude of losses in the collapsed state is affected rather by xMNa (the modulus G″ increases with increasing ionization) than by the heterogeneous structure of the samples. 相似文献
3.
Miloslav Bohdanecký 《Polymer Bulletin》1993,31(1):117-122
Summary Critical values of the polymer volume fraction 2,c and the interaction parameter c have been computed for the case that the equation for the chemical potential of solvent contains terms c
2
3
and c
2
4
in addition to
2
2
. For 0 c 1/3, the limits for infinite chain length are
2,c
= 0 and
c
= 0.5. Quite different results are obtained for c > 1/3,
2,c
being finite and
c
lower than 1/2. Conclusions for the estimation of the temperature and the entropy-of-dilution parameter are discussed. 相似文献
4.
Organic compounds dissolved in water can be decomposed on a layer of n-TiO2 particles irradiated by u.v. light, which generates holes and electrons in the TiO2 material. Dissolved oxygen was used as electron scavenger and holes reacted with water to give OH radicals. The rate of degradation of the dissolved organic compounds by OH radicals is limited by the transfer of either oxygen or of theorganic compounds to the surface of n-TiO2 particles. The consequence of these limits is that, in the batch mode reactor with recirculation of the liquid, the dependence of the concentration of an organic compound on time has either a linear or an exponential form. Experiments with decomposition of oxalic acid in aqueous solutions using a plate reactor (60 cm × 120 cm) confirmed the analysis. Equations for evaluation of the mass transfer coefficient of the dissolved species to the surface of the plate reactor with a moving liquid fil m were developed for the case of the thickness of the Nernst diffusion layer being thinner than the thickness of the liquid. The experimentally obtained decomposition rate of oxalic acid was about 60 to 80% of the theoretical decomposition rate limited by oxygen flux through the film of a moving liquid. The present theory neglects the diffusion of oxygen into the porous layer of n-TiO2. 相似文献
5.
We give drawings of a complete graphK
n
withO(n
4 log2
g/g) many crossings on an orientable or nonorientable surface of genusg 2. We use these drawings ofK
n
and give a polynomial-time algorithm for drawing any graph withn vertices andm edges withO(m
2 log2
g/g) many crossings on an orientable or nonorientable surface of genusg 2. Moreover, we derive lower bounds on the crossing number of any graph on a surface of genusg 0. The number of crossings in the drawings produced by our algorithm are within a multiplicative factor ofO(log2
g) from the lower bound (and hence from the optimal) for any graph withm 8n andn
2/m g m/64.The research of the third and the fourth authors was partially supported by Grant No. 2/1138/94 of the Slovak Academy of Sciences and by EC Cooperative action IC1000 Algorithms for Future Technologies (Project ALTEC). A preliminary version of this paper was presented at WG93 and published in Lecture Notes in Computer Science, Vol. 790, 1993, pp. 388–396. 相似文献
6.
Online bin stretching is a semi-online variant of bin packing in which the algorithm has to use the same number of bins as an optimal packing, but is allowed to slightly overpack the bins. The goal is to minimize the amount of overpacking, i.e., the maximum size packed into any bin. We give an algorithm for online bin stretching with a stretching factor of \(11/8 = 1.375\) for three bins. Additionally, we present a lower bound of \(45/33 = 1.\overline{36}\) for online bin stretching on three bins and a lower bound of 19/14 for four and five bins that were discovered using a computer search. 相似文献
7.
8.
9.
We have found experimentally that rf SQUID's working in a nonhysteretic mode with small critical currents give exactly at resonance and at very low rf bias a triangular pattern with a period equal to half of one elementary quantum of magnetic flux. We discuss a possible explanation of this peculiar result. 相似文献
10.
Karel Veselý 《国际通用系统杂志》2013,42(2):197-216
Real systems can include two types of state variables – dynamic and static. While dynamic state variables are a common part of each system, static variables are not and their presence in a system may cause some problems if standard system theories are used. In this paper, it is shown that, due to a new system theory (NST), it is possible to work correctly with systems and subsystems which include not only dynamic state variables, but also static state variables. If standard system theories are used, static variables in the real system cause not only problems in describing systems but also some challenges in control theory. These challenges involve, for example, some questions of controllability, reachability, or observability of a plant that includes static variables or the optimal control design of a plant that includes statical state variables. Some of the challenges mentioned are addressed in this paper after a brief introduction of the NST. 相似文献