A statistic method of power requirement of engine in High Working Frequency Area (HWFA) is proposed. The power requirements of the engine in different typical driving cycles are statistically analyzed. The weighting function of the interval of the engine efficiency, D_m, is defined according to the power requirement. Then the degree of engine working efficiency in typical driving cycles is calculated based on the weighting function and efficiency function. The more suitable engine for Hybrid Electric Vehicle (HEV) can be determined by taking D_m as index. Through simulation analysis and testing, the most economic engine was chosen from the optional engines.

In order to improve the torque control accuracy and response in Electric Power Steering (EPS) using induction motor, an EPS mathematical model was established. When using D-Q current model as the rotor flux observer, the impact the of the variation of rotor resistance on the torque control was analyzed. The feedforward and feedback integrating control and on-line resistance identification were employed to improve the accuracy of torque control and current tracking response. Simulation results show that the proposed method can significantly improve the current response speed and accuracy in induction motor control of EPS system.

The performance of the front taper-leaf spring suspension system of a truck was analyzed using the software Abaqus. From the simulation results, the match rule of the hinger was found, which allows us to design better suspension system. The brake case was also simulated in this paper, and the results can help us to find the design basis of the anti-S shape bumper.

According to the characteristic that, in bus rollover accident, the window pillar withstands unequal rollover crash moments, an approach of variable cross-section stamping column is proposed and cross-section dimension of column is studied. First, finite element method is used to simulate the performance of uniform cross-section stamping column, and experiments is conducted to validate finite element method. Then, finite element method is applied to simulate the performance of variable cross-section stamping column in bus rollover. Results show, compared with uniform cross-section column, the variable cross-section stamping column can significantly improve the safety in bus rollover accident.

The mathematical models of drag torque and shift synchronization process of multi-plate wet clutch were established. Simulation was carried out in Matlab/Simulink. Simulation results were compared with experiment results. It is demonstrated that the models are correct and accurate. The influences of friction pair gap in multi-plate wet clutch, cooling oil flow rate and properties of cooling oil under different temperature etc. on the drag torque, shift synchronization time and energy were analyzed. This study may provide a reference for theoretical study and structural design of the multi-plate wet clutch, and for the transmission system matching.

To achieve energy saving effect for forklift truck, a system of hybrid forklift drive and energy recovery is designed. In order to theoretically analyze the forklift hybrid system and find out the effective approach, which can be used to achieve energy saving, a real 3.0 t forklift is adopted and the corresponding hybrid system simulation model is built. Many simulation tests are carried out to analyze the energy saving effect. To validate the simulation results further, an energy saving system is built. The simulation and test results show that, under standard working condition, the hybrid forklift can obtain the energy saving effect of 20.8% and its energy resaving system can obtain energy resaving rate by 34.6%.

Rotary torque is one of the key factors that influence the dynamic performance of bogie. The torque measuring method of the bogie is studied. Then based on the spatial kinematics, the mathematical model of the inverse kinematics solution of the bogie is established. Combined with the bogie rotary test requirements, the real-time solution is obtained by means of the Simulink simulation model. Using MATLAB/cftool curve fitting tool, the hydraulic cylinder telescopic quantity is fitted with high precision, proving that the relation between the cylinder telescopic quantity and time can be described as the piecewise function. This provides the parameter foundation for the rotation simulation of the bogie rotation platform.

In this paper a Bus Rapid Transit (BRT) speed induction model based on the Kalman travel time prediction is proposed. First, the stop time prediction model in the bus station, and the Kalman travel time prediction model between the bus station and the intersection are established. Second, according to the difference of the vehicle arriving time at the intersection, four speed induction models are introduced. Finally, the BRT travel data in the city of Changzhou is used to test the effectiveness of this model. The results show that this model can significantly improve the efficiency of the BRT system, and it has a good engineering application prospect.

A multi-modal traffic equilibrium model with combined modes is proposed. First, the super-network theory is applied to describe the traffic network with combined modes. Second, the mode and route choices are considered to be stochastic under elastic demand based on the generalized cost function. Using the network equilibrium theory, an equivalent variational inequality model is proposed after analyzing the network equilibrium conditions. Next, the existence and uniqueness of an optimal solution are given. Finally, a solution algorithm for solving the model is developed and validated by a numerical example. The influences of different parameters on Origin-Destination (OD) demand and modal split are analyzed. These results show that this model can reflect the combined travel behavior more practically and has certain generality.

In order to solve the problem due to the unbalanced passenger demand, a single line transit mixed scheduling model for zonal vehicles is proposed. This model takes the factor into consideration that the bus companies generally rely on government subsidies and there exist financial constraints in big cities in China. With the target of maximizing the total social benefit, the model simultaneously optimizes the frequencies of zonal and full-length vehicles as well as turn-back point. The impact of financial constraints on transit optimization is explored, proving that financial constraints are equivalent to diminishing the value of passenger's time. Furthermore, a numerical example is present, and the relations among frequency, turn-back point, and cost under financial constraints are analyzed. Compared with the optimized single-line scheduling, the results indicate that mixed scheduling can save vehicles, the passenger travel time and the cost under unbalanced demand situation and financial constraints. The benefits for both operators and passengers can be obtained by reasonable allocation of vehicle operation form under financial constraints.

Based on the original data of traffic accidents in a typical highway tunnel group region, a grey forecasting model, which is modified by residual error model, is proposed to analyze the development trend of traffic accidents in highway tunnel group region. The forecasting accuracy is improved by introducing Markov optimization. Compared with commonly used forecasting method, the proposed method in this paper has a better forecasting accuracy and practicality in a period. It can be used for the forecasting analysis of traffic accidents and for security early warning in highway tunnel group region.

In order to accurately calculate the displacement and the stress of any point on the Continuously Reinforced Concrete Pavement (CRCP) under thermal stress, the stiffness equation of the CRCP is established using the contact element theory. This equation is based on the bond-slip relation between reinforced steel bar and concrete, and the subgrade friction effect is taken into consideration. The finite element solution of the stress and displacement along the whole pavement is obtained by considering the combined action of crack interval and beams-on-foundation. Based on the theoretical model, the distribution rule of the stress and displacement of the steel and concrete in the CRCP under thermal stress is analyzed. The numerical simulation results of the whole pavement validate the feasibility of the proposed method.

The air voids distribution of three gradations of aggregate is characterized using X-ray computed technology and digital image processing technology. Furthermore, a mathematic model is proposed to describe the air void distribution inside the asphalt mixtures by means of statistical analysis. The results show that both the gradations of aggregate and compaction methods have considerable influence on the air voids distribution within the specimens. Results also show that the voids distribution is symmetric along the depth of the Marshall specimens, whereby, the air voids distribution in the statically compacted specimens in nonsymmetrical along the depth that the number of air voids on the top part of the specimen is bigger than that at the bottom part. There is little difference between the target void fraction and the mean void fraction of the Marshall specimens; while the mean void fraction of the static compaction specimens is over 1.4 times of the target void fraction. In comparison with the Marshall specimens in uniform gradation of aggregate, in the statically compacted specimens, the number of air voids is bigger and the fluctuation along the depth is more remarkable, but the void size is almost consistent. Sstatistical analysis validates the applicability of the two parameter mathematical model to characterize air void distribution in asphalt mixture, and to quantify the effects of compaction methods and gradation of aggregate on air voids.

The friction loss of a First Automobile Works (FAW) produced engine was reduced by a method, which combines tribology structural optimization design and the Diamond-Like Carbon (DLC) film. Based on the friction strip-down test and the performance test, the effects of main parameters of the crank-connecting rod mechanism and valve train on engine friction loss were investigated. The influence of engine friction loss on the fuel consumption was also investigated. The test results show that tribology structural optimization design and the DLC film can effectively decrease the mechanical friction loss of the engine. The average mechanical friction loss of engine at different speeds is decreased by 17.1%, and the average fuel consumption is decreased 2.5%.

In order to determine the outlet pressure of hydrodynamic retarder at the early design stage and shorten the design cycle, the internal flow field of hydrodynamic retarder was calculated in CFD numerical simulation software according to velocity-inlet boundary and outflow boundary conditions. The outlet pressure distribution calculated from the flow field was solved by area-weighted average algorithm. Then the outlet pressure values under different rotor speeds and charging ratios were obtained. The results show that the outlet pressure of the hydrodynamic retarder is a quadratic function of the rotor speed and a linear function of the charging ratio. This research obtained the mathematical expression that describes how the outlet pressure response to variations of the rotor speed and charging ratio, which provides the basis for the control system design of a hydrodynamic retarder.

The vibration theory is used to investigate the vibration situation of a hydraulic relief valve under hydrodynamic shock. The vibration model of the relief valve is proposed, the natural frequency and transient response of the relief valve are studied. Numerical simulation of the vibration of the relief valve is carried. Simulation results may provide the foundation for the working safety and reliability of the hydraulic relief valve.

The reliability model established using traditional statistical method for the spindle in machining center with small sample size may be biased in the real case. Therefore, a modified reliability modeling method for small sample size was proposed using Bootstrap-Bayes approach. First, the reliability function of time between failures using empirical modeling method was established. Then the accurate of the parameters prior distribution of Bayes method was provided. This method improves the precision of prior distribution built by traditional empirical method. In order to calculate the posterior distribution of parameters, Monte Carlo simulation was developed. Finally, a real-world example of the spindle of one kind of machining center was presented using the proposed approach to show its potential application. The results show that the proposed method can provide an accurate reliability model for small sample failure data.

This paper presents a method of the reliability modeling of a series system. Such a system is composed of several mutual independent subsystems, and the system life-time obeys two-parameter Weibull distribution. In this method, when one of subsystems is failure, the fault data of the other subsystems are processed as censored data, and the failure sequence is revised using the average rank time method. This method can be applied for model parameter estimation and fitting test to reduce the modeling error and improve the accuracy. Finally, as a case study, the real data of a Computerized Numerical Control (CNC) are used to demonstrate the application of the proposed method, which verifies the effectiveness and applicability of the method.

This article presents a design method of visual comfort of automobile seat based on Kansei engineering and TRIZ theory. First, in the early design stage of automobile seat, a customer survey was conducted to obtain the customer's preference of design symbols and elements. Then based on the principle of formal aesthetics, design integration was carried out to found the psychological preference of special group of customers. Second, the TRIZ theory was used to recombine the function and structure, and to achieve a new conceptual prototype design. Finally, objective evaluation and validation of the design were conducted using eye tracker. The results show that the proposed design method and procedure are effective, and can be used as universal design research method. The design procedure is easy to operate and is economic.

The concept of equipment criticality has the characteristics of fuzziness and diversity of evaluation index. Uniform evaluation method uses the same weight assignment for different evaluation objects, which does not reflect the optimality of evaluation. To overcome this problem, a new method for equipment criticality evaluation is put forward based on fuzzy matter-element analysis, combing with the concept of Euclid approach degree. The method integrates grey relation analysis based on the cosine distance and data envelopment analysis in a unified way to determine the index weight according to Pareto rule. The fuzzy matter-element model is applied to compute the equipment criticality, thus the grade classification of equipment criticality is obtained. Then, as a case study, experiment on seven equipments in a production line of an agro-machinery enterprise is carried out. The results show that the method can avoid the uncertainty in estimating the weights subjectively, increase the basic discrimination in the evaluation, so it outperforms the available traditional methods.

To solve the problem of limitation of traditional spatio-temporal reasoning in static space, and the problems in Rupam's orientation relation composition table and conceptual neighborhood graphs, a dynamic reasoning method based on Rupam's orientation relations model was proposed. First, the ROR base relations'composition table and conceptual neighborhood graphs are improved; a static reasoning algorithm is proposed and a ROR based relations'composition table is created; an auto-generated algorithm to produce conceptual neighborhood graphs of orientation relations is put forward. A comparison of the composition table and conceptual neighborhood graphs with those of Rupam was conducted and results show that the composition table and conceptual neighborhood graphs are more complete than Rupam's. Then a dynamic reasoning method (DRA) is proposed. To demonstrate the effectiveness of DRA, an application of smart home was illustrated based on the composition table and neighborhood graphs.

A layer-sensitive XML document collection clustering method CXLI is proposed in this paper. First, a concept of structural table is put forward to clear up the duplication structures in XML documents. Second, the constraints of editing operations are established. Third, a testing method of the similarity between XML documents is presented. Finally, the XML documents are clustered using agglomerative hierarchical clustering method. ACM SIMOD data set and synthetic data set are used to test the proposed method. Results show that the proposed CXLI has better precision under similar time cost.

In Quality of Service (QoS)-guaranteed composite Web service selection, it is difficult to obtain the accurate measurements of QoS. Meanwhile, users' QoS requirements are hard to describe. To address these concerns, a novel method of Web service selection is proposed. It uses interval numbers to describe users' QoS requirements and QoS metrics of Web services, and introduces user satisfaction degree to evaluate the composite services. Base on a Particle Swarm Optimization with Dynamic Boundary (DBPSO), the method tries to find appropriate composite service scheme that meets the users' global QoS requirements. Simulation results show that the proposed method is both feasible and effective.

A feature selection algorithm based on random forest (RFFS) is proposed. This algorithm adopts random forest algorithm as the basic tool, the classification accuracy as the criterion function. The sequential backward selection and generalized sequential backward selection methods are employed for feature selection. The experimental results on UCI datasets show that the RFFS algorithm has better performance in classification accuracy and feature selection subset than the other methods in literatures.

In view of the recursive structure in π-calculus, a kind of Petri net translation of recursion π-calculus is presented. Following the basic process translation rules and combination rules, the translation uses the hierarchical method. When the recursive structure executes many times, excessive more Petri net nodes will be generated. To solve this problem, a more compact representation for this Petri net is defined, which preserves the semantics of the system in that it encodes exactly the same set of traces. The bisimulation of recursion π-calculus and the Petri net transition is proved, as well as the equivalence between Petri net and its more compact representation.

In order to solve the problem of the low delivery ratio caused by the limited resources in Delay-Tolerant Networking (DTN), the routing mechanism based on multiple copies is usually used to improve the delivery ratio. However, it may lead to the problem of the overload of node buffer caused by the excessive numbers of copies, then network congestion happens. This paper proposes the congestion control strategy based on Markov meeting time span prediction model CCSMP. It mainly specifies the line method and discarding mechanism of nodes buffer. The predicted messages meeting earlier with destination node are lined in the first, and the messages with lower utility values are discarded as far as possible. Then the congestion problem caused by the limited node buffer is solved. Simulation in ONE environment is carried out to compare the proposed strategy with the two congestion control strategies, Drop-Front(DF) and Drop-Oldest(DO). Simulation results show that the congestion control strategy proposed by this paper improves the message delivery ratio, reduces the average network delay, and to a certain extend reduces the overhead ratio and packet dropped rate.

It is particular difficult to make reasonable access control in multi-domain networks. In order to meet unexpected and dynamic nature of inter-domain access and to improve the accuracy and comprehensiveness of the judgment, this paper proposes a fused access control mechanism ATM-UCON based on the SRM model of usage control. It realizes the three authorization modules to attribute-based judgment, trust-based judgment, and mission-description-based judgment. It also provides a feasible implementation mechanism of UCON.

The problem of correctness of authenticating results of preference top-k query in cloud computing is investigated. On the basis of existing dominant graph, Authenticated Dominant Graph with Hash (ADG-H) and Authenticated Dominant Graph with Signature (ADG-S) are proposed. ADG-H can be used to authenticate the result correctness of snapshot query effectively. For continuous monitor, an adoptation of ADG-H can incur prohibitive network overhead, so ADG-S was proposed, by which necessary network transmission can be conducted only when the query results or verification objects are affected by data update. Extensive experiments demonstrate the effectiveness of the proposed ADG-H and ADG-S.

In order to solve the problem of the false matching in detecting copy-move forgeries, an improved method based on Scale Invariant Feature Transform (SIFT) and HSI was proposed in this study. First, the SIFT key points and SIFT feature vector are extracted. Secondly, for each SIFT point the HSI feature is extract. Finally, the SIFT feature vector and the HSI feature vector between every two different key points are matched to determine the copy-move regions. The experimental results show that the proposed algorithm based on SIFT and HSI can reduce false matching rate in comparison with the SIFT algorithm, the SURF algorithm and the improved SIFT algorithm. The proposed algorithm has higher robustness even when an image is distorted by Gaussian blur, white noise and JPEG recompression.

According to the human visual attention mechanism, an image salient region detection method is proposed. The salient features of image are extracted in spatial domain using local clutter density contrast and global color distribution estimation, and extracted in frequency domain using the efficient band divided method. Then, referring to the principle that cells respond to stimuli, such features are combined using the theory of feature combination. Local clutter density contrast imitates the law of universal gravitation, computing the visual attention on sparse matrix model. The efficient band divided method is used in combining information of amplitude for salient feature detection in frequency domain, later utilizes all features with weight. Experiment results show that the algorithm can effectively extract salient regions. The visual attention model is effectively applied to virtual and reality interaction to detect the effective region in real scene.

First,the basic classic ICM is analyzed and its structural drawbacks are detected. Second, the proposed ⅡCM is presented, which not only declines the number of parameters required setting, but also constructs the time matrix T to settle the problem of setting the number of iterative times; meanwhile, he transformation from the image spatial information to time information can be realized. Third, the noisy pixels are located uilizing the information provided by the time matrix T in ⅡCM. Finally, the task of efficiently filtering the impulsive noise in the image is completed by the proposed adaptive algorithm for image de-noising based on ⅡCM. Because of only dealing with the polluted pixels and adjusting the size of area window adaptively, the proposed technique has remarkable superiority over other ones in both simulation performance and running efficiency.

The thermodynamic of interactions between siRNAs and target mRNAs is crucial for the efficiency of its interference. RNAup is a software provided by Vienna RNA package, which can predict the accessibility of target region. By adding its predicted thermodynamic characteristics to the SiRNA sequence features and screening the efficient siRNA with support vector machines, the model can well predict efficient siRNA that the accuracy rate is up to 88.12%, the sensitivity and specificity are up to 88.35% and 87.94%, respectively.

In order to improve recognition rate of the iris recognition system, the Gabor filter is studied, and the weighted Hamming distance based on analytic hierarchy process is proposed. First, the feature image is generated through different scales and directions of the odd symmetric Gabor filter. Then, the recognition correct rate and error rate are acquired by Hamming distance matching. The appropriate scale and direction are selected to calculate the weighted Hamming distance. The weight is calculated by analytic hierarchy process. Finally, the weighted Hamming distance is used to iris recognition. The equal error rate of CASIA2.0 and MMU1 are decreased by 0.64% and 0.56%, respectively. The experimental results show that this method has better recognition performance and robustness.

An image stabilization method is proposed for the problems existing in the video acquired from high altitude airship platform. It can remove the fog in the intra-frame images and filter the high frequency vibration components in the inter-frame images. The image enhancement technique Retinex is adopted to remove the fog in the intra frame images. It retains the details of the image, and restores the genuine color of image. Then, the four freedom global motion mode is established to estimate the global motion, and the median filter is adopted to smooth the global motion and remove the high frequency vibration components. It achieves the image stabilization in the inter-frame images. The algorithm of constructing the undefined area is given at the same time. Through the practical application, the algorithm proposed in this paper achieves the image stabilization for the video acquired from airship platform perfectly. It gets good image stabilization results in the intra-frame images and inter-frame images, which meet the requirements of monitoring and analyzing.

When using level-of-detail (LOD) technology, multi-scale regular grid visualization always introduces discontinuous mesh on the boundary with different resolutions. The GPU-based LOD framework for cracks repairing is investigated, and a parameterization method to avoid cracks is proposed. The function curve fitting is employed to change the mesh layout and eliminate T-junctions caused by various LODs transiting. Moreover, the parameterization cracks-repairing method supports multi-span LOD using curve function family excellently. Function curve fitting method is utilized to existing regular-grid-based LOD model. The experiments show that the proposed method can improve the cracks-repairing performance meanwhile guarantee the mesh continuity.

In the traditional segment-based stereo matching approaches, local matching tends to get high mismatching rate; mover over, the plane fitting method has its limitation. In order to obtain high accuracy of disparity map, the initial disparity map is obtained by combining the improved local matching method with global one. Simultaneously, the surface model is utilized to fit each segmented region, and a decision rule of regions merging is proposed. The simulation results show that the proposed algorithm can obtain higher accuracy and more smooth disparity map between texture regions. Besides that, superior results are realized in both low-texture and texture-occluded regions.

To enhance the multi-source image fusion accuracy, an adaptive fusion method based on image quality assessment parameter in Nonsubsampled Shearlet Transform (NSST) domain is proposed. The Source images are decomposed to subband images with multi-scale and multi-direction in NSST. The low frequency subband fusion rule is based on the structural similarity index with spatial frequency as coefficient weights. For the high frequency subands, the fusion rule of coefficient absolute value with neighborhood average energy consistency selection is adopted. The fused low and high frequency coefficients are reconstructed to image by nonsubsampled shearlet inverse transform. Fusion experiments are conducted with several sets of different modality images, and the objective assessment of fused results is done. The experiment results show that the proposed algorithm performs better in subjective and objective assessments than a few existing multi-scale fusion techniques, and obtains better fusion performance.

This paper proposes a novel video saliency computational model based on frequency domain analysis, which is simple and efficient. First, the original video is parsed to a series of consecutive video scene images. Then, the space domain saliency and time domain saliency of the video scene images are computed, respectively. In each domain, the saliency of each frame is estimated by using Renyi entropy. Finally, both space domain and time domain results are fused to obtain the overall saliency. Application results in video advertising system and comparison with state-of-the-art approach demonstrate the effectiveness of the proposed model.

To meet the demands of large data of rough surfaces in the research of surface engineering and the characteristics of joint surfaces, a new numerical simulation method of 3D non-gaussian rough surfaces is proposed. Based on the assumed utocorrelation function (ACF), the non-linear equations are constructed for computing transformation matrix, and the improved non-linear conjugate gradient method is used to solve the equations. Then according to the assumed skewness, kurtosis and other statistical parameters of the rough surface, the 3D non-gaussian rough surfaces are generated by combining Johnson transformation system. The simulation results show that, the skewness and kurtosis relative errors of the simulated rough surfaces are less than 3%, the fitting result of ACF curves of simulated rough surfaces with the theoretical ACF is good. Using this method the rough surfaces with the given parameters of height and autocorrelation function can be accurately simulated.

A multi-staging area check method for distributed wireless sensor networks is proposed. The method is different from the zero boundaries and the added middle section method. With this method, the strategy with arbitrary segments for check and adjusting the transmission according to the reliability parameter from the signal strength is achieved. To reduce the transmission energy and reduce the error rate, the methods of the maximum a posteriori (MAP) and equal gain combining (EGC) are applied in the data fusion center for final check. Simulation results show that the proposed method has better adaptability. Compared with traditional method, multi-staging area check method can significantly reduce transmission error rate and reduce the energy consumption of the network.

A new model of orthogonal Frequency Division Multiplexing (OFDM) system based on pseudo-random-postfix was proposed. In view of the requirements of channel estimation under slow time-varying channel, a channel estimation method based on first-order statistics and a low-complexity equalization using the property of circular matrix diagonalization were proposed. The performance of Bit-Error-Rate (BER) was simulated and analyzed under the Additive-White-Gaussian-Noise (AWGN) channel, frequency selective fading channel and Doppler channel. The simulation results show that the proposed method can be applied to the slowly time-varying channels, such as the slow-moving case, and can achieve better BER performance than the traditional Cyclic Prefix (CP)-OFDM. However, the performance may get worse for the Doppler scenarios.

A regularized adaptive matching pursuit algorithm as proposed after research and summarize the existing greedy algorisms based on block-sparse signal. This algorithm mainly in the light of regularized method under a condition that a block-sparse degree is unknown, so that the signal support set can be determined more accurately by the algorithm, then we can reconstruct a signal precisely. First, the algorithm initializes a sparsity degree and step size of a block signal; by maximizing the correlation between residual and measurement matrix, it realizes the selection of subset of the signal support. Then the algorithm updates the selected subset in the second time. Finally, the exact support set is acquired through iteration. The experimental results prove that the proposed algorithm can get better reconstruction performance than other existing greedy algorithms based on block signal, and it has less iteration number and iteration time than the other adaptive algorithm based on block signal.

A modified OMEGA-K imaging algorithm is proposed to reduce the computational complexity of the Method of Series Reversion (MSR) 2D point target spectrum for the bistatic Synthetic Aperture Radar (SAR). By performing the cancellation of the high order term of range history in range-frequency azimuth-time domain, 2D point target spectrum can be matched with low order Taylor expansion of echo signal, so that the focused imaging can be achieved by the OMEGA-K algorithm. The simulation results indicate that the modified OMEGA-K for range history approximated by second order Taylor expansion can achieve better focused performance than that of conventional algorithm for range history approximated by second order Taylor expansion, and approach the performance of the conventional algorithm for range history approximated by three order expansion. This demonstrates that the proposed algorithm has a good focusing performance by low order Taylor expansion, thus lowers the computational complexity.

In view of high experimental cost of laser system, this paper is intended to make substitution experiment of artificial circuit for erbium-doped fiber ring laser. After post-processing, a random number sequence is realized and the randomness is verified by the NIST special publication tests. This physical true random sequence can be applied to digital image encryption. Experiment results show that the proposed scheme has a large key space together with excellent statistical properties. It has good feasibility and safety which can resist all kinds of attacks.

A new dynamic loading approach is proposed, which is based on asynchronous motor direct torque control. An asynchronous motor under direct torque control model is selected as the loading motor. It is connected to the testing motor through a speed reducer. The direct torque control instruction of the loading motor is determined by the running condition and load torque features of the testing motor. The loading motor works at four quadrant operation, providing demanded torque to the testing motor. The proposed method was applied on permanent magnet synchronous motor speed control system. Simulation result shows that the proposed approach can provide dynamic loading demanded torque quickly and exactly. It can also reduce torque ripple influence on the dynamic loading induced by direct torque control.