摘要：A novel Discrete Wavelet Transform (DWT) based Hidden Markov Module (HMM) for face recognition is presented in this letter. To improve the accuracy of HMM based face recognition algorithm, DWT is used to replace Discrete Cosine Transform (DCT) for observation sequence ex- traction. Extensive experiments are conducted on two public databases and the results show that the proposed method can improve the accuracy significantly, especially when the face database is large and only few training images are available.

摘要：This study was carried out to investigate the possibility of titanium alloy metal powder production using low-power plasma *** argon DC non-transferred arc plasma torch was designed,and numerical analysis was conducted to determine the plasma jet properties and wire *** highest velocities inside the nozzle attachment were between 838 and 1178 m/*** velocities of the jets at the apex were between 494 and 645 m/s for different gas flow *** studied plasma gas flow rates had no significant effect on the effective plasma jet *** was shown that the plasma jet length can be estimated by numerical analysis using the temperature and velocity changes of the plasma jet over *** was observed that the powders produced were spherical without any *** a result of this study,a plasma torch was developed and powder production was performed successfully by using relatively low torch power.

摘要：The shortage of fossil fuels and the disastrous pollution of the environment have led to an increasing interest in artificial photosynthesis. The photocatalytic conversion of CO2 into solar fuel is believed to be one of the best methods to overcome both the energy crisis and environmental problems. It is of significant importance to efficiently manage the surface reactions and the photo-generated charge carriers to maximize the activity and selectivity of semiconductor photocatalysts for photoconversion of CO2 and H2 O to solar fuel. To date, a variety of strategies have been developed to boost their photocatalytic activity and selectivity for CO2 photoreduction. Based on the analysis of limited factors in improving the photocatalytic efficiency and selectivity, this review attempts to summarize these strategies and their corresponding design principles, including increased visible-light excitation, promoted charge transfer and separation, enhanced adsorption and activation of CO2, accelerated CO2 reduction kinetics and suppressed undesirable reaction. Furthermore, we not only provide a summary of the recent progress in the rational design and fabrication of highly active and selective photocatalysts for the photoreduction of CO2, but also offer some fundamental insights into designing highly efficient photocatalysts for water splitting or pollutant degradation.

摘要：This paper describes the construction and enumeration of mixed orthogonal arrays (MOA) to produce optimal experimental designs. A MOA is a multiset whose rows are the different combinations of factor levels, discrete values of the variable under study, having very well defined features such as symmetry and strength three (all main interactions are taken in consideration). The applied methodology blends the fields of combinatorics and group theory by applying the ideas of orbits, stabilizers and isomorphisms to array generation and enumeration. Integer linear programming was used in order to exploit the symmetry property of the arrays under study. The backtrack search algorithm was used to find suitable arrays in the underlying space of possible solutions. To test the performance of the MOAs, an engineered system was used as a case study within the stage of parameter design. The analysis showed how the MOAs were capable of meeting the fundamental engineering design axioms and principles, creating optimal experimental designs within the desired context.

摘要：Accurate fault detection and diagnosis is important for secure and profitable operation of modern power *** this paper,an ensemble of conflict-resolving Fuzzy ARTMAP classifiers,known as Probabilistic Multiple Fuzzy ARTMAP with Dynamic Decay Adjustment(PMFAMDDA),for accurate discrimination between normal and faulty operating conditions of a Circulating Water(CW)system in a power generation plant is *** decisions of PMFAMDDA are reached through a probabilistic plurality voting strategy that is in agreement with the Bayesian *** results of the proposed PMFAMDDA model are compared with those from an ensemble of Probabilistic Multiple Fuzzy ARTMAP(PMFAM)*** outcomes reveal that PMFAMDDA,in general,outperforms PMFAM in discriminating operating conditions of the CW system.

摘要：This paper first reviews the current state of multimedia teaching resource sharing in China as well as the problems encountered. It then proceeds to the focus that a good way out for the dilemma is to design a platform of multimedia teaching resource sharing based on cloud service concept.

摘要：For further exploring the confidentiality of optical communication,exponential synchronization for the delayed nonlinear Schrodinger equation is *** is possible for time-delay systems to generate multiple positive Lyapunov exponents without the limitation of system ***,the homoclinic orbit analysis is carried out by using the bifurcation theory,and it is found that there are two homoclinic orbits in the *** to the corresponding relationship,solitary waves also exist in the ***,the Melnikov method is used to prove that homoclinic orbits can evolve into chaos under arbitrary perturbations,and then chaotic signals are used as the carriers of information *** Lyapunov exponent spectrum,phase diagram and time series of the system also prove the existence of ***,an exponential synchronization controller is designed to achieve the chaotic synchronization between the driving system and the response system,and it is proved by the Lyapunov stability ***,the error system is simulated by using MATLAB,and it is found that the error tends to zero in a very short *** simulation results demonstrate that the proposed exponential synchronization scheme can effectively guarantee the chaotic synchronization within 1 s.

摘要：To provide an accurate prediction of the product component dependence of temperature and pressure in vacuum distillation and give convenient and efficient guidance for the designing of the process parameters of industrial production, according to the molecular interaction volume model(MIVM), the separation coefficient(β) and vapor-liquid equilibrium composition of Au-Ag alloy at different temperatures are calculated. Combined with the vapor-liquid equilibrium(VLE) theory, the VLE phase diagrams, including the temperature-composition(T-x) and pressure-composition(p-x) diagrams of Au-Ag alloy in vacuum distillation are plotted. The triple points and condensation temperatures of gold and silver vapors are calculated as well. The results show that the β decreases and the contents of gold in vapor phase increase with the distillation temperature increasing. Low pressures have positive effect on the separation of Ag and Au. The difference between the condensation temperatures of gold and silver is about 450 K in the pressure range of 1-10 Pa.

摘要：Based on the D-H notation, kinematics model and inverse kinematics model of 6R industrial robots are established. Using graphical method, the boundary curve equations of the 6R industrial robot workspace are obtained. Based on the prescribed workspace, the D-H parameter optimization method of 6R industrial robots is proposed. Using the genetic algorithm to determine the structural dimensions of a 6R robot, we make sure that its workspace can exactly contain the prescribed workspace. This method can be used to reduce the overall size of the robot, save materials and reduce the power consumption of the robot during its work time.

摘要：In this work, we develop an artificial foldable wing that mimics the hind wing of a beetle （Allomyrina dichotoma）. In real flight, the beetle unfolds forewings and hind wings, and maintains the unfolded configuration unless it is exhausted. The artificial wing has to be able to maintain a fully unfolded configuration while flapping at a desirable flapping frequency. The artificial foldable hind wing developed in this work is based on two four-bar linkages which adapt the behaviors of the beetle＇s hind wing. The four-bar-linkages are designed to mimic rotational motion of the wing base and the vein folding/unfolding motion of the beetle＇s hind wing. The behavior of the artificial wings, which are installed in a flapping-wing system, is observed using a high-speed camera. The observation shows that the wing could maintain a fully unfolded configuration during flapping motion. A series of thrust measurements are also conducted to estimate the force generated by the flapping-wing system with foldable artificial wings. Although the artificial foldable wings give added burden to the flapping-wing system because of its weight, the thrust measurement results show that the flapping-wing system could still generate reasonable thrust.