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This research aims at increasing the utilization of platinum-ruthenium alloy (Pt-Ru) catalysts and thus lowering the catalyst loading in anodes for methanol electrooxidation. The direct methanol fuel cell’s (DMFC) anodic catalysts, Pt-Ru/C, were prepared by chemical reduction with a reducing agent added in two kinds of solutions under different circumstances. The reducing agent was added in hot solution with the protection of inert gases or just air, and in cold solution with inert gases. The catalysts were treated at different temperatures. Their performance was tested by cyclic voltammetry and potentiostatic polarization by utilizing their inherent powder microelectrode in 0.5 mol/L CH3OH and 0.5 mol/LH2SO4 solution. The structures and micro-surface images of the catalysts were determined and observed by X-ray diffraction and transmission electron microscopy, respectively. The catalyst prepared in inert gases showed a better catalytic performance for methanol electrooxidation than that prepared in air. It resulted in a more homogeneous distribution of the Pt-Ru alloy in carbon. Its size is small, only about 4.5 nm. The catalytic performance is affected by the order of the reducing agent added. The performance of the catalyst prepared by adding the reductant at constant temperature of the solution is better than that prepared by adding it in the solution at 0°C and then heating it up to the reducing temperature. The structure of the catalyst was modified, and there was an increase in the conversion of ruthenium into the alloyed state and an increase in particle size with the ascension of heat treatment temperature. In addition, the stability of the catalyst was improved after heat treatment.

A novel diversity-sampling based nonparametric multi-modal background model is proposed. Using the samples having more popular and various intensity values in the training sequence, a nonparametric model is built for background subtraction. According to the related intensities, different weights are given to the distinct samples in kernel density estimation. This avoids repeated computation using all samples, and makes computation more efficient in the evaluation phase. Experimental results show the validity of the diversity-sampling scheme and robustness of the proposed model in moving objects segmentation. The proposed algorithm can be used in outdoor surveillance systems.

Feature selection is a process where a minimal feature subset is selected from an original feature set according to a certain measure. In this paper, feature relevancy is defined by an inconsistency rate. A bidirectional automated branch and bound algorithm is presented. It is a new complete search algorithm for feature selection, which performs feature deletion and feature addition in parallel. Its bound is determined by inconsistency rate of the original feature set, hence termed as ‘automated’. Experimental study shows that it is fit for feature selection.

In this paper, we investigate the performance of the well-known optimal velocity car-following model (the OVM) with numerical simulation in describing the acceleration process that is induced by the motion of a leading car with a pre-specified speed profile. Results show that this model is to some extent deficient in performing this process. Modification of the OVM to overcome the deficiency is demonstrated. The linear stability for the modified model is analysed. If the linear stability condition can not be satisfied, phase transitions occur on varying the initial homogeneous headway of the traffic flow.

This paper deals with the design and development of bipolar Ni/MH batteries. After optimizing the parameters of bipolar plates by adjusting electrode thickness and modifying the capacity ratio of two adjacent electrodes of a single cell, some bipolar Ni/MH stacks with a voltage of 6 V were assembled and examined. Electrochemical testing results showed that the bipolar battery has excellent high rate discharge and recharge characteristics, satisfying pulse discharge performance even in a low state of charge (SOC). Moreover, the battery showed good stability during pulse cycles as simulating hybrid electric vehicle working conditions. It would be a promising alternative for power storage system in hybrid electric vehicles.

A novel wavelet-based algorithm for image enhancement is proposed in the paper. On the basis of multiscale analysis, the proposed algorithm solves efficiently the problem of noise over-enhancement, which commonly occurs in the traditional methods for contrast enhancement. The decomposed coefficients at same scales are processed by a nonlinear method, and the coefficients at different scales are enhanced in different degree. During the procedure, the method takes full advantage of the properties of Human visual system so as to achieve better performance. The simulations demonstrate that these characters of the proposed approach enable it to fully enhance the content in images, to efficiently alleviate the enhancement of noise and to achieve much better enhancement effect than the traditional approaches.

Pieces of nonpulverized misch metal (Mm) alloy were used as working electrodes (WEs). The WEs were cathodically charged in H2 and O2 atmospheres, respectively, and the electrode potentials were determined. The morphologies of definite areas of WEs were observed by SEM, and the surface composition in chemical elements of these areas were determined by EPMA. The results indicated that the main causes of the degradation of WEs might be the increase of internal stress, the expansion of crystal lattice, and the preferential dissolution of Mm during charging, rather than the oxidation of the alloy by O2, which was accordant with the presence of La3+ and Ni2+ in the MH electrode of MH/Ni batteries after cycling.

An appropriate amount of toluene 2,4-diisocyanate (TDI) was added into polyether ([(CH2 CH2O)13CH2O]n)]Li salt electrolyte to form a cross-linked network, with improving the film processability and thermal stability. The relation between the structure and ionic conductive properties of the cross-lined polyether electrolytes was investigated by means of Fourier transform infra-red spectroscopy (FTIR), differential scanning calorimetry (DSC), mechanical property and AC impedance spectroscopy. The electrolytes system is found to have two glass transitions, and it is found that the two Tgs increase with increasing salt concentration. At the same Li salt concentration, the conductivity of cross-linked polyether/LiN(CF3SO2)2 complex system is higher than that of LiClO4. At EO/Li=25∶1(mol ratio), the former conductivity changes with temperature, while the later coincids with Arrhenius formula (σ=Ae−EalRT). The cross-linked polyether/LiN(CF3SO2)2 electrolyte exhibits the maximum σ=10−4.75 S/cm at 30°C.

Atmospheric duct is a common phenomenon over large bodies of water, and it can significantly affect the performance of many radio systems. In this paper, a two-month (in July and August, 2014) sounding experiment in ducting conditions over Bosten Lake was carried out at a littoral station (41.89° N, 87.22° E) with high resolution GPS radiosondes, and atmospheric ducts were observed for the first time in this area. During the two months, surface and surface-based ducts occurred frequently over the Lake. Strong diurnal variations in ducting characteristics were noticed in clear days. Ducting occurrence was found at its lowest in the early morning and at its highest (nearly 100%) in the afternoon. Duct strength was found increasing from early morning to forenoon, and reaching its maximum in the afternoon. But contrarily, duct altitude experienced a decrease in a clear day. Then the meteorological reasons for the variations were discussed in detail, turbulent bursting was a possible reason for the duct formation in the early morning and the prevailing lake-breeze front was the main reason in the afternoon. The propagation of electromagnetic wave in a ducting environment was also investigated. A ray-tracing framework based on Runge–Kutta method was proposed to assess the performance of radio systems, and the precise critical angle and grazing angle derived from the ray-tracing equations were provided. Finally, numerical investigations on the radar performance in the observed ducting environments have been carried out with high accuracy, which demonstrated that atmospheric ducts had made great impacts on the performance of radio systems. The range/height errors for radar measurement induced by refraction have also been presented, too, which shows that the height errors were very large for trapped rays when the total range was long enough.

An efficient process for developing aluminum alloys for alkaline battery anodes is described. The addition of gallium to aluminum eliminates remarkably the anisotropy of aluminum, and thus renders its electrode potential more negative. The uniform distribution of alloying elements is an essential factor for lowering the corrossion rate of the alloy. The accumulation of an alloying element at intergranular bounderies, or the formation of a secondary phase that contains the element, will result in a rise in the corrosion rate of aluminum.

On the basis of grey theory model for medium-long term load forecasting, the paper improves the traditional grey model and brings forth the grey residual forecasting model for less prediction errors. At the same time, it uses fixed weight method of forecasting model--that is to choose weight with average precision of each model to build a optimization combination forecasting model. It forecasts with the historical load data of some area, and proofs that combination forecasting method is superior to single forecasting model, Its forecasting error is less than 1%. Finally it forecasts future five year loads of some area, and provides a tech support and theoretical foundation for area Power Company.

The physical parameters, e.g. power and phase, are usually employed in the neural analysis of brain rhythms, which are important in brain function and disease diagnosis. Though there has been extensive work, how both parameters are related to the electrical properties of brain tissue and the sources of brain rhythms has not been fully understood. To address the issue, a simulation is done based on the theory of dipole current. When referring to the solution to the forward problem in electroencephalograph, the brain is regarded as a homogenous sphere model, the electrical features of brain tissue are described by an isotropic electrical conductivity. The source of brain rhythms is simulated by the quasi-static dipole current whose activity is described as a sine oscillation at low frequency. The electrical field generated by the dipole current is considered to be quasi-static. By changing the amplitude and the phase time course of oscillatory dipole current, the distribution of potentials produced by the dipole current at a time-point could be calculated by applying the finite element method to the sphere model. Over a time period of sine oscillation, the oscillatory potentials regarded as the brain rhythms could be produced. Instantaneous power and phase of simulated rhythms are estimated by Hilbert transform, and then a method of phase stability in narrow-band is developed for a single oscillator. To highlight this method, three manners are employed to describe it, i.e., mean relative phase value termed phase preserved index, histogram on rose plane, and phase sorting with the help of EEGLAB. Finally the relationship between two physical parameters and the electrical features of brain tissue/the source activity of brain rhythms is investigated under the conditions of (an) isotropy of conductivity, linear or nonlinear phase dynamics and amplitude, eccentricity of dipole current, etc. The statistical methods of t-test and bootstrapping technology are performed respectively to show the significance of power and phase stability. It is obtained that the power of simulated rhythms decreases with the increase of electrical conductivity, and it is not only proportional to the square of the amplitude of dipole current, but also correlated with the anisotropy of conductivity and the locations of dipole current as well as meshes on the sphere model, however no relevance to other factors. On the contrary, the phase stability of simulated rhythms is correlated only with the non-linear time course of their own phase dynamics. The results imply that the power of brain rhythms is related to many factors such as brain tissue and amplitude of rhythm generator as well as placements of recording electrodes, but the phase stability is related only to the non-linear phase dynamics of brain rhythms. Thus, the electrical significance of the power is more complicated than that of the phase stability. This work might be helpful for understanding in depth the significance of both physical parameters from the perspective of electricity. The narrow-band phase stability of simulated rhythms could highlight the non-linear phase dynamics. It is hypothesized that the phase stability could not only map the synchrony in the neural activity as a custom means of phase coherence, but also reflect directly the non-linearity in phase dynamics, and the more divergent the phase dynamics, the lower the phase stability is, and vice verse. Therefore it is suggested that the phase stability of brain rhythms could be related closely to the non-linear factors to affect the phase dynamics of brain rhythms, e.g., the non-linear phase dynamics of rhythm generators. It is also suggested that both parameters of power and phase stability would offer more neural information.

The intention of this paper is to help bridging the gap between knowledge base and computer vision system. A knowledge-based vision system for identification of overlapping objects is presented. The authors place emphasis on the reasoning strategy based on knowledge base for recognizing of occluded workpieces to provide information with an education Robot. The experimental results are given and some problem are discussed.

This paper presents an improved stereo matching algorithm by heuristic strategy technique resulting from that the stereo matching problem can be cast as a search one. After early processing, our algorithm employs two search ways. One is intra-scanline search and the other a inter-scanline search. Both of them a can be calculated separately and treated as the problem of finding an optimal path on 2-D search graph by graph searching method with the concentration on minimizing some combination of cost of the path and effor of the search required to get the path, that is heuristic. Our algorithm hs been tested with block scences and its computational requirements have been discussed too.

A novel method for spectral similarity measure, which is called nonlinear spectral similarity measure, is presented in This work. In this method, all original spectral vectors are, firstly, nonlinearly transformed into a feature space. Next, kernel PCA is used to construct a set of orthogonal coordinate base in feature space. All transformed spectral vectors are projected onto the orthogonal coordinate space. In kernel principal component analysis (KPCA), the nonlinear translation function is implicatively implemented by kernel function. Moreover, all projected spectral vectors are constrained by spectral continuum removal curve. Because of continuum removal curve, various bands contribute the similar measurement differently. The more absorption, the more the contribution in similarity measurement. At last, linear or general linear similarity measure, for example spectral angle mapper, was used to measure the similarity between two nonlinearly transformed spectra. Our experiments show that this method is effective in spectral similarity measure.

A new method for natural color image segmentation using integrated features is proposed in this paper. Edges are first detected in term of the high phase congruency in the gray-level image. K-means cluster is used to label long edge lines based on the global color information to estimate roughly the distribution of objects in the image, while short ones are merged based on their positions and local color differences to eliminate the negative affection caused by texture or other trivial features in image. Region growing technique is employed to achieve the final segmentation results. The proposed method unifies edges, both the whole and local color distributions, as well as the spatial information to solve the natural image segmentation problem. The feasibility and effectiveness of this method have been demonstrated by various experiments.

Vehicle detection is one of the key technologies in intelligent transportation system (ITS), and it is an important stage of vehicle tracking in visual surveillance. Due to the clutter of traffic scenes, the captured video sequence involves many large noises. In analyzing human vision, the non-object area and shape suppression are defined, and a new noise-removing algorithm is proposed. To reduce the computational complexity, the sequential algorithm is improved. Experimental results show the effectiveness and efficiency of the algorithm in extracting the moving vehicles in a cluttered scene. The output of the vehicle's contour is very complete and accurate, and can be used in vehicle tracking system to improve the performance.

Digital watermarks have been proposed for the copyright protection of multimedia products. Most schemes were performed primarily for fidelity considerations, and not specifically to improve the detector performance. In this paper, a robust and blind watermarking scheme is presented. The concept of communication with side information was applied at the encoder to improve the probability of detection within acceptable fidelity, and the template matching technique was employed to estimate the undergone attacks in attacking channel. This scheme is optimized by optimal design of the encoder to match with the media content and the decoder to adapt to the attack channel state. Experiments show that our method is robust against some common attacks such as filtering, compression, rotation, scale, and translation. It can be applied to both color and gray images.

Video object (VO) is an important concept in MPEG-4. For objects can be easily manipulated without visible distortion, the copyright protection of video objects becomes an important issue. This paper presents a watermarking scheme for video objects. Different from other methods, the proposed scheme employed inertia ellipse to achieve fast synchronization recovery in case the object was manipulated. Shape adaptive DCT and visual mask were combined to embed the watermark into the arbitrarily shaped object, which was designed to achieve the trade-off between the invisibility and the robustness. Experiments show that our algorithm is robust to object manipulations such as rotations, translations, scaling and lossy compression. Our scheme can be easily incorporated into the object-based coding framework of MPEG-4.

We present a vision system that can be to recognize 3D objects. Surfaces are characterized by surface curvature. Qualitative features are shown to be effective in pruning the search space of possible scene interpretations explored by the recognition and localization technique. Within this paradigm, we implemented a system which extracts planar patches, and patches of quadrics of revolution from a depth map. Reconstructed features are indexed into a model database to verify object hypotheses using the Hough technique. Our approach is surface based and is not sensitive to noise or occlusion. >

In this paper, based on the equivalent transmission line model a method of designing left-handed metamaterials micro-structures is proposed, verified and analyzed. Firstly, according to the basic transmission line model with left and right-handed characteristics, we build a new left-handed model by analogy. Then according to the qualitative analysis of the corresponding relationship of each component in the transmission line network to the shape and size of continuous medium micro-structure configuration, the specific size of model is inferred, and thus a reasonable left-handed metamaterials micro-structure configuration and the corresponding transmission line model are established. We have conducted a series of tests including numerical simulation, which verifies that there does exist the left-handed characteristic in a certain frequency band. Finally based on the numerical simulation and experiment the effects each micro-structural parameter on left-handed frequency position and bandwidth are analyzed, and the size parameter that affects the left hand characteristic most seriously is determined.

An efficient method for camera calibration in traffic scenes based on the use of the vanishing line is presented. The approach uses only a set of three parallel edges with identical known distance and a perpendicular line to gain the parameters of the orientation, position and the focal length of the camera.

A new video watermarking scheme is proposed to resist object manipulations. Shape-adaptive DCT and a visual mask were combined to embed the shuffled watermark into the arbitrarily-shaped object. Inertia ellipse was employed to achieve fast self-synchronising watermark detection. Experiments show that the algorithm is robust to geometrical attacks.