Abstract:According to the principle of topological projection invariance, the spatial graph contour extraction problem is processed in twodimensional projection plane. In order to automatically determine the projection plane, a method of normal vector dynamic composition is put forward. In addition, deformation parameter is introduced to validate the effectiveness of spatial closed contour, and the corresponding calculation method is given. The mathematical model of spatial graph contour extraction is established and the extraction method based on the model is constructed. The practical application verifies the stability and practicality effectiveness of the method.

Abstract:In order to reduce energy consumption of chilled plant, a new control strategy with variable flow and variable temperature for allvariable chilled plant based on orthogonal experimental analysis is presented. The presentation and the implementation idea of that control strategy are firstly introduced. Secondly, a screw chiller model and a pump model are established, and these two models are then coded and embedded into the TRNSYS software to simulate and verify. Finally, a surfacewater chilled plant simulation platform composed of chillers and pump are developed based on TRNSYS. By using conducting quadratic orthogonal regression experiment on that platform, the empirical correlation formula between the total power of chilled plant and cooling load, supply cooling water temperature, cooling water flow, chilled water flow, and supply temperature of chilled water is obtained. By data processing, the optimized values of chilled water flow, cooling water flow, and supply temperature of chilled water which make the total power of chilled plant minimum under different cooling load and supply cooling water temperature are also gotten. Result shows that the new control strategy can decrease the power of chilled water plant by 4.94 kW and 14.023 kW respectively relative to the constant speed and the conventional variable speed, the saving power can increase by 54.6% relative to the corresponding conventional variable speed plant does.

Abstract:The effect of ions on sonolytic degradation of two typical organophosphorus pesticides (parathion and dimethoate) is investigated. In experimental condition ranges, both the parathion and dimethoate degradation conform to pseudo firstorder kinetic model. With the increasing of ionic strength, the degradation rate of parathion and dimethoate increases at first then decreases. When the ionic strength is 0.01 mol, the degradation rate of parathion and dimethoate increase by 7.2% and 18.6% respectively. The effect of ionic strength on dimethoate degradation is more significant compared to parathion. The reducible cations Fe2+ and Mn2+ at level of 0.1 mM have an obvious catalytic effect on both parathion and dimethoate degradation, and the catalytic effect of Fe2+ is more obvious than Mn2+. The catalytic effect of Fe2+ and Mn2+ increases firstly but then decreases with the increase of the cations levels. The CO-3 , HCO-3, and Cl- at the level of 0.01M exhibit inhibitory effect on both parathion and dimethoate degradation, and their inhibition degrees follow the order of CO-3>HCO-3> Cl-. But only 1mM of Br- has an obvious catalytic effect both on parathion and dimethoate degradation, and the effect increases with the increasing Br- level.

Abstract:A new method for analyzing the coupling degree of stressedlap driving forces based on the gray correlation analysis theory is proposed. One of the surface shape displacement vectors corresponding to stressedlap driving forces is taken as the primary sequence, and the others as the secondary sequences. The sequences are pretreated by using initial value processing, and the graycorrelationcoefficients (GCC) of subsequences are calculated. The graycorrelationdegree (GCD) can therefore be obtained using the GCCs of the subsequences. According to the concept of GCD, the GCD is explained as the coupling degree of secondary sequence to the primary sequence to achieve the quantitative calculation of coupling effect between the motors placed on a stressedlap. The proposed method provides a useful tool to make deep analysis and reasonable control strategies for stressedlap control systems. A case study on the coupling degree of an activelap with diameter 420 mm, 12 drivers, and 60 micromovement sensors shows that simulating results coincide with the actual situation, which means the proposed method can accurately describe the coupling degree between various drivers of a stressedlap.

Abstract:The burning rate of hydrogenair premixture on mesoscale is mainly determined by its chemical reaction rate. So a Laminar Finite Rate Model, the gas phase reaction mechanism for the combustion of hydrogenair mixture which consists of 19 reversible elementary reactions and the dynamic mesh method are adopted to simulate the combustion of hydrogenair mixture in a mesoscale IC engine which operates a quasi gas power cycle under ultrahigh combustion load. The combustion of hydrogenair mixture on mesoscale in the micro combustion chamber with moving boundary can be stable. The complete thermodynamic process of heat addition, internal energy increasing, and a boundary work output producing during expansion can be perfectly achieved in the closed combustion system of the mesoscaled IC engine igniting the hydrogenair mixture by wire surface of high temperature. However, running parameters such as cycle period, initial pressure and fuel/air ratio have complex effects on the hydrogenair combustion of micro closed container with moving boundary.

Abstract:By analyzing the startup process of automated mechanical transmission(AMT), fuzzy control algorithm of clutch engagement speed and constant engine speed in part during startup are proposed based on comprehensive consideration of driver’s startup intention and startup performance indices. Through dividing shift process of AMT into seven stages, clutch control logic and goal speed control algorithm of engine during the shift process are put forward. Aiming at the emergency braking condition, a control strategy of jump downshift during braking and a determination method of target gear are also proposed. In order to verify the validity of control strategy, an AMT prototype vehicle is developed and the test of startup, shift and jump downshift are carried out.

Abstract:As blank drawing resistance in sheet metal forming process can be significantly influenced by the changes of drawbead height, and highstrength steel (HSS) is one of the materials difficult to be formed, so a controllable drawbead technology is proposed to improve the formability of HSS. A numerical simulation model and an experimental device of JAC590YHSS box deep drawing with fixed drawbead are established. Comparative analysis of simulation and experimental results show that the difference of fixed height drawbeads has a significant effect on the formability of HSS. A controllable drawbead moving path of ascenthaltdescent is designed based on the variations of deep drawing force in the sheet metal forming process. Then the path is applied to the formation of an automobile engine tunnelside panel which is similar to the box deep drawing. Twenty group test schemes of good formation are obtained, in which the part smallest thickness is significantly influenced by controllable drawbead. Moreover, in the twenty group test schemes, the optimized combination of moving path and main influence factor H2 are found by range analysis of part average smallest thickness. Finally, the correlation between part smallest thickness and factor H2 is predicted by using GABP neural network and regression analysis.

Abstract:A novel doubleringplate gear reducer (DRPGR) is designed and its experimental validation is conducted. By using the closedgraph method, the modification coefficients of internal gearing in DRPGR are determined. Based on this, the overall structure of the reducer is designed and its kinematics simulation is achieved. With APDL programming language of ANSYS, a 3D finite element (FE) model of DRPGR is established, and its modal analysis and loaded tooth contact analysis (LTCA) are conducted respectively. The modal analysis reveals that the lower natural frequencies of DRPGR are much higher than the input frequency and the lower modes can be classified as vertical and horizontal bending of input and output shafts. The LTCA indicates that three pairs of gear teeth contact simultaneously at rated output torque. Due to the multiteeth contacts, the maximum stress is much lower than the permissible stress of internal gearings. The experimental tests of the prototype validate that DRPGR is adapted to both singledriven and dualdriven work condition. When singledroved, DRPGR can eliminate the kinematic uncertainty by non180degree phase difference design. DRPGR claims a better dynamic performance in dualdriven work condition. The efficiency of DRPGR increases with the increment of output torque and the reducer has an excellent shortterm overloaded capacity. The experimental results validate that the proposed method can be used to guide the design of that kind of reducer.

Abstract:In the intelligent robot suit, the output performance of piezoelectric sensor array is easy to be influenced by nontarget factors, such as environment temperature, voltage fluctuation and so on, resulting in obvious measurement precision decrease due to the intercross interference among the sensors. Aiming at the above problem, a new tactile sensor array as well as signal processing method for distributed pressure measurement is presented. The processing flow of sensor signal is designed to extract and effectively process the useful data in the confidence distance matrix and relation matrix by means of mathematical statisticsbased approach. The fusion processing technique with maximum probability method and maximum likelihood method for multisensor information is presented. The experimental result shows that the proposed method can eliminate the temperature impact on pressure sensor to reduce the error influence from uncertainty of single sensor and enhance the stability and measure precision for distributed pressure measurement data, which outstandingly improves the reconstruction precision of pressure image.

Abstract:Noise in the structural vibration signal affects the identification accuracy of the modal parameter and generates false mode. The direct identification method is with lowaccuracy and limited in application scope, while the frequency domain average method could improve the identification accuracy of the modal parameter and be good at identifying the modes drown in noise. The improved LSCE wavelet threshold filtering method,is with remarkable denoise effect, which can reach or even surpass the effect of three times averaging in identification accuracy, and with fast identification. By comparing three structural modal identification methods, it shows that the improved LSCE wavelet threshold filtering method can save test costs and improve the recognition speed and accuracy. The improved LSCE wavelet threshold filtering method shows obvious applicability and generalization.

Abstract:Based on GRIMech 3.0 mechanism, using kinetic model, the auto ignition characteristics of nature gashydrogenair mixture are studied in different initial conditions under constant pressure. This study focuses on the changes of temperature and component concentrations，ignition delay time and flame propagation speed. The results show that under different initial conditions, with the increase of hydrogen fraction in the mixture, the ignition delay time decreases significantly and flame propagation speed increases significantly. On the other hand, Hydrogen fraction has been found of little influence on flame temperature.

Abstract:PXWAE Acoustic Emission System is useol to investigate the acoustic emission behavior of shale under fourpoint bending test. In these tests, the maximum bending stress, bending strain, acoustic emission hits, acoustic emission energy and etc., are recorded. The results show that when vertical loads impose on the shale sample which has horizontal stratification planes, Kaiser effect does exist under fourpoint bending tests. Kaiser point can be recognized directly from the stress vs. cumulative AE hits curve. But by the impact of shale’s stratifications and local failure during the tests, strain relaxation occur which makes it difficult to determine the Kaiser point only by the strain vs. acoustic emission curve. An accurate conclusion can be achieved by a comprehensive judgment combing with all test data, as well as the failure mode of rock sample. The research on acoustic emission behavior of rock in the stress state during bending tests to some extend can provide guidance to engineering practice for stability monitoring of mine roof or separation layer with acoustic emission monitoring technology.

Abstract:Aim at the problem that the EO imaging tracking system is inconsistent with the model of probabilistic data association with amplitude information (PDAAI), which supposes that the greater the amplitude value is, the greater the probability of being the tracked target will be, a modified PDAAI (MPDAAI) is presented . Based on the fact that the amplitude and the motion of the interested target are consistent in a short period, the MPDAAI models the amplitude information and the motion information of the target as well as their consistency with Markov stationary signal to analyze the association procedure of motion and amplitude. The lower bounds of CramerRao estimation error for PDAAI and MPDAAI are calculated and discussed in detail. The theoretical analysis and experimental results show that estimating the target motion with the MPDAAI will be more accurate and more reliable than estimating with the original PDAAI.

Abstract:The settling behaviors of rectangular particles with different initial orientation angles, aspect ratios and Reynolds numbers are simulated by using finite element arbitrary LagrangianEulerian domain method. The results show that the settling behaviors of the rectangular particle are affected significantly by the initial orientation angle under certain Reynolds number. With the increasing initial orientation angle, the fluctuation of the orientation angle, setting velocity，rotation velocity and lateral drifting velocity all increase. The impact of aspect ratio on the process of settlement has a strong relationship with the magnitudes of length and width. However, regardless of the magnitudes of length and width, when aspect ratio increased, final settling velocity decreases accordingly. Reynolds number of particle deposition process has a great impact on sedimentation process as well. If the Reynolds number is below a critical value, the particle eventually settles steadily. At larger Reynolds number，the oscillation of lateral motion and orientation angle become persistent. An inverted Tstructure forms due to the interaction between particles when many particles fall in the channel, and particles tend to horizontally positioned when the time span increases.

Abstract:The combustion process of HCCI engine fueled by primary reference fuels is simulated using the CHEMKIN software, and the results are compared with a combustion experiment of a HCCI engine. The cluthors study the influence of various factors, including fuel composition, compression ratio, equivalence ratio, initial temperature and initial pressure, on HCCI engine fueled with PRF. The results indicate that the ignition delay increases along with the increase of the octane number. The initial temperature, initial pressure, compression ratio, equivalence ratio have significant effects on the ignition timing. The operating range of the combustion on HCCI engine is limited.

Abstract:For the energyaware schedule of batterypowered realtime embedded system, a novel offline energyaware schedule algorithm is proposed based on the improved artificial fish school algorithm(IAFSA). The algorithm constructs the behavior constraint of the artificial fish to make the random search meet the energy constraint and deadline while maximizing the system reward. Experimental results show that the proposed algorithm improves the system reward about 47% compared with the Greedy algorithm. Besides, the energy efficiency increases while the energy budget decreases, which demonstrates the good energyawareness efficiency of the proposed algorithm.

Abstract:It has been verified that the ICA can isolate sources from multichannel magnetoencephalography (MEG) signals. Based on the route of constrained ICA (cICA), this paper achieves a new solution of MEG inverse problem called functional source separation (FSS) by adding a functional constraint to the cost function of a basic ICA model. Source activity is obtained by applying this method to one MEG signal dataset under a selfpaced finger tapping task. The result is proved effective by calculating correlation coefficients between the weight vectors of function source separation method and the spatial filter coefficients of SAM method. It is found that finger tapping related functional source was localized in motor cortex of precentral gyrus. At the same time, the temporal and frequency information provided by FSS method could be a basis of exploring cortical control timing mechanisms associated with finger movements and extracting time frequency characteristics of the functional source.

Abstract:For separate transmission of received data and current fuze status data in a paasive setting system, a dual channel transmission method based on LSK and PSK is proposed. The corresponding feedback transmission model is set up. The methods for circuit realization and circuit parameters selection are also presented. This method has the advantage of easy circuit realization, low energy consumption, and quick and reliable information feedback. The test shows it can realize the stable dual feedback of 6.25 kbps setting data and 50 kbps status data of fuze in the same wireless channel when the DC voltage is not lower than 3 V. The design and modulation of principal prototype have been completed.

Abstract:DFT(discrete fourier transform)based discrete multitone (DMT) transceivers have achieved great success in high speed data transmission. When the cyclic prefix is no shorter than the channel impulse response (CIR), the DMT system is ISI (intersymbol interference) free. For the channels with very long CIR, such as DSL loops, timedomain equalizer (TEQ) is typically added at the receiver to shorten the impulse response and improve performance. This paper proposes a filter banks approach to design the TEQ to maximize the bit rate. A DMT system is introduced with a pair of complex conjugating TEQs. For the design and implementation costs, the scheme shows the best performancepriceratio.

Abstract:To improve the head detection accuracy in video sequences captured with fixed vertical monocular camera, a novel method of head recognition based on mean shift and multiple features is proposed. Firstly, mean shiftbased image segmentation algorithm with color information and spatial information is suggested to derive the candidate head components in images. Furthermore, by referring to two features that the contour of human head regions are approximate round and the hair color distribution is clustered, the evaluation models based on the contour information and inside color information of candidate head components are presented for head recognition. The experimental results show that the proposed algorithm can effectively reduce the light interfere and eliminate fake target whose color information is similar to hair color distribution. The detection rate for static images can reach about 89.4%.

Abstract:It is difficult to distinguish the cheating and other malicious behaviours in the grid service trust evaluation. A trust evaluation model for grid service based on compensation is proposed.With market mechanism, service provider and demander present the expected profit and compensate price for their behaviours to maximize their own profit. The game theory is applied to balance the expected profit and compensate price. Based on the game theory, evaluation trade strategy achieves perfect Bayesian equilibrium. Service provider and demander can choose their own trade strategy to maximize profit. Theoretical analysis and simulation results show that the service demanders can abandon the cheating motivation voluntarily, while the service providers can make right decision to choose trust evaluation. Compared with the existing model, the precision and security of the trust evaluation is enhanced greatly, while the calculating and communication cost is reduced remarkably.

Abstract:By analyzing shortages of current MSPCA model, an online multivariable statistical process monitoring method is proposed, which uses some concepts from online multiscale filtering and can be applied to sensor fault diagnosis. In the method, wavelet decomposition is employed to the signals using edge correction filter in a fixedlength data window, and then wavelet denoising is conducted with wavelet threshold filtering. Next, an online multiscale model is constructed for data combining wavelet transformation and adaptive PCA in the previous data window. This model avoids time waste in direct signal denoising and reduces time cost in multiscale data with conventional PCA, which eventually increases accuracy in fault diagnosis. Experiments on eight vibration signals of 6135D diesel engine under severe leak condition prove the practicability and feasibility of the proposed method.

Abstract:A novel audio steganalysis method is proposed.. the audio signal is denoised with wavelet transform. Then, a part of noise signal with different length is intercepted circularly and is used to calculate the crosscorrelation sequence with the rest of the noise signal. With the wavelet discontinuity detection technique, the feature is extracted from the crosscorrelation sequence for steganalysis and find out the stegaudio. The detection rate is determined by the embedding strength of the secret message other than the embedding capacity. Experimental results show that the more embedding intensity of PN sequence is, the higher the detection rate will be. The detection rate of the algorithm is above 80% when the strength of the PN sequence is about 0.002, which demonstrates that the proposed algorithm has good detection performance.