Abstract:The thermal stress and vibration characteristic of original structure of gasoline engine manifold catalytic converter are calculated with the fluid-structure thermal simulation. The heat transfer boundary conditions，such as the temperature of fluid boundaries and stress distribution，are calculated. Then，the thermal stress and vibration characteristic of original structure of manifold catalytic converter are calculated with Finite Element Analysis technology. According to the results，the thermal stress is excessive in entrance flange area. It is easy to produce the thermal stress concentration and is damaged easily in this area. In addition，the thermal deformation is large in the junction area between exhaust manifold and catalytic converter. Finally，the improved structure is presented according to the calculation results. The corresponding analysis and comparison show that the improved structure is better than the original structure in the highest temperature，the maximum thermal stresses and the vibration characteristic.

Abstract:Management system for Lithium iron phosphate(LiFePO4) power batteries group is built，based on car battery series charge features. Series charge experiment of power batteries group is carried out using battery charger. Single cell voltage and state of charge(SOC) is analyzed in series charge for batteries group. Dispersivity influence of single cell is studied on charge performance of the battery packs，small current supplementary charge equalization is proposed，to make single cell battery state of charge is basically almost the same. Theoretical analysis and experimental results show that single cell voltage difference is very large，but SOC difference is very small in the end of battery series charge. A novel battery packs charge equalization method is presented，which avoids the problem of some batteries overcharge and other batteries less chargedproblem.

Abstract:Through the study of bus technology，memory database technology，and virtual instrument technology，a new architecture of message bus based testing system is proposed to reduce the resource of testing equipment，and the cost of testing system. The core technology is using message bus instead of traditional testing bus，and using virtual instrument instead of hardware. The specific implementation is that gathering signal by computer standard bus based data acquisition card；processing，analyzing the data and illustrating the result by virtual instrument；and operating virtual instrument by message bus. The message bus based testing system architecture is characterized by low cost，strong extension and high system integration. Finally，the feasibility of the system architecture is proved by a testing application.

Abstract:The electric field sensor for the measurement of electric field in the space where the sensor probe will cause distortion in the vicinity，so it will affect the measurement of electric field accuracy. This paper uses the separation of variables method to calculate the electric field distortion caused by spherical sensor probe in uniform electric field，and detailed analysis of the 10 kV voltage，the spherical probe size，electrode material and the measuring electrode pole coupling caused the impact of electric field distortion. According to the induced voltage of sensor and the linear relationship between electric field strength，using the impact factor matrix to correct the electric field distortion. The result shows that the vicinity of the probe and the primary measuring electrodes and sub-electrodes measuring produce more serious distortion in the uniform electric field. The average distortion rate is more than 27%；however，after the impact factor matrix is used to correct the electric field distortion，the average error is about 4.47%. By analysis of the measurement of the electric field distortion with the spherical probe of sensor，it is conducive to reduce the impact of distortion on the electric field measurement and to improve the accuracy of field measurement.

Abstract:With aims of improving braking stability and the capability of capturing braking energy of an electric urban bus with parallel regenerative braking strategy，the influence on the reclaiming efficiency of braking energy under the braking stability demand is analyzed. Following ECE R13 and using the positional relation between generalized braking force distribution line and generalized expected braking force distribution curve，the braking intensity of electro-mechanical parallel braking under parallel braking strategy is determined between 0.1 and 0.3 with a consideration on engineering practices of an electric urban bus. Braking force distribution ratio of a mechanical braking system system during electro-mechanical parallel braking is adjusted to maximum within the regulation permissible range by inertia proportional valve. ADVISOR2002 is redeveloped to build a simulation model of a rear-wheel-drive electric vehicle. Simulation results with this strategy show a significant improvement of an electric urban bus braking energy reclaiming performance under the typical urban driving cycles conditions.

Abstract:A feature extraction algorithm for porphyrin sensor array (PSA) images is presented. At the first step, it achieves an automatic tilt correction for PSA images based on radon transform. Then automatic mesh generation is applied to PSA images based on the method of combining projection binarization and mathematical statistics. The areas of porphyrin spots are locating by local threshold segmentation for the images which have achieved mesh generation. Finally, feature values of porphyrin spots are extracted by radius ratio method from the porphyrin spot areas. The algorithm solves the problem that identification of weak signal spots is quite difficult, and the extracted feature values are the maximum point to reflect the information of porphyrin spots. By ammonia, isoprene, aldehydes and other gases tests, the results show that the algorithm can effectively extract feature values of porphyrin spots in PSA images.

Abstract:A scheme of inductive wireless receiver circuit is put forward, according to special requirement of inductive wireless power supply in artificial subretinal prosthesis circuit. The proposed receiver circuit can be divided into CMOS rectifier, regulator and self-biasing circuit. The CMOS rectifier is used to provide power supply for regulator and self-biasing circuit. The self-biasing circuit furnishes the regulator with bias voltage and bias current which is independent from power supply. The proposed receiver circuit is designed by Cadence tool and Chartered 0.35 μm CMOS device model, and oscillator in artificial subretinal chip is used as the proposed receiver circuit’s load. The results show that the proposed receiver circuit can provide load capacity of 3.3 V and >1 mA,with a layout size of 62 μm×195 μm.

Abstract:Using ammonia as coolant, experiments are performed to investigate heat transfer characteristics and surface temperature distribution for the spray cooling of 350 W/cm2  high power solid state laser. When the heating power and spray height were constant, the cooling surface was mainly dominated by forced convective heat transfer, high inlet flow rate of liquid ammonia resulted in low surface temperature and uniform temperature distribution. When the volumetric flow was 0.461 L/min, the cooling surface temperature was only 2.6 ℃ and the temperature deviation was ±1.1 ℃, the heat flux dissipated could reach 388 W/cm2. As the inlet volumetric flow decreased, the dominant heat transfer mechanism for spray cooling gradually converted the forced convective heat transfer to the boiling while increasing heat flux, resulting in decrease of uniform temperature distribution of heat transfer surface.

Abstract:Considered strength classes of concrete, ratio of structural steel to concrete, ratio of steel tube to concrete and eccentricity ratio of load, 6 test specimens of steel tubular columns filled with structural and concrete are designed. The damage phenomena of specimens are described in detail and the failure mechanism is analyzed. The results show the initial failure of the specimens are began from the yield of steel tube, the ultimate failure are ended from the buckling of steel tube caused by the expansion of core concrete. Due to the existence of structural steel, the ductility of specimens is superior to steel tubular columns. Before the yield of steel tube, the plane cross-section assumption of specimens can be put into use. The ultimate bearing capacity of specimens is increased with the increase of strength classes of concrete, ratio of structural steel to concrete and ratio of steel tube to concrete. But the ultimate bearing capacity and ductility are decreased with the increase of eccentricity ratio.

Abstract:The influences of flow-equilibrating device on flue gas purification by spray drying are studied numerically with RNG k-ε turbulent model and stochastic droplet track model. The effects of flow-equilibrating device on flue gas streamline, droplets distribution, internal resistance, adhering ratio and purification efficiency are investigated. The flow field is more uniform and symmetrical after the flow equalization plate is added. The internal resistance decreases gradually with increasing diameter of the opening area of flow equalization plate. The percentage of droplet adhering on the wall is first increased, and then decreased when opening area diameter increases from 0.2 to 0.7 m. The maximum value reaches 38.2% when the diameter equals to 0.4 m. The purification efficiency for SO2 and HCl has increased after the plate is added. The desulphurization efficiency increases from 60.25% to 68.56%. HCl removal efficiency increases from 93.73% to 97.62%. The results can provide theoretical basis for flue gas purifying system optimization and parameters selection.

Abstract:Based on an actual project of a suspen-dome steel roof under construction, the constraint performance of cable-strut joint of a suspen-dome is studied precisely. Experiments of a full-scale cable-strut joint are conducted on and both the slipping performance and the failure mode of the joint are obtained. The concept of slipping force density is proposed to describe the slipping performance of the joint. The static friction factor is also gained in the test and the test values are compared with analytical ones. In comparison with the smooth clamping groove, the ribbed clamping groove is proposed against the deficiency of clamping strength of the joint after the cable being tensioned. The experimental and analytical results demonstrated that 10% prestress loss occurs in seal sleeve and socket ear, so that pre-stretching is recommended as compensation. In the experiment, primary joint fails with pulling out of the cable and damage of the out layer PE. The maximum slipping force for primary joint is 150 kN with the slipping force density of 18.3 kN/mm. The measured friction factor is 0.24, which agrees well with the FEM results. The maximum slipping force for the ribbed joint is 240 kN，and the measured slipping force density is 26 kN/mm, which increase, up to 42% compared with that of primary joint. It is indicated that the ribbed damping groove can fasten the cable more efficiently, and improve the sliding-resistance performance of the cable-strut joint. The research provides references for the application of this joint.

Abstract:For the practical application of nonlinear, non-Gaussian noise system state estimation，this paper develops the ANFIS- Particle filter cascaded filtering model based on the adaptive neuro-fuzzy inference system(ANFIS) nonlinear approximation function and particle filter’s obvious advantages for non-linear state estimation. ANFIS is used to eliminate the bias in the colored noise of the signal, then the filtered signal is processed by the particle filter to realize the optimal state estimation. The simulation results demonstrate that with the cascade filter model the mean and variance are reduced by 65% and 74% respectively, ANFIS-particle filter model has significant noise cancellation effect for strongly nonlinear systems, and the state estimation accuracy has been greatly enhanced, which verifies the effectiveness of the proposed model.

Abstract:An axial symmetric invariable temperature phase change interface model of capillary porous wick based on alkali metal thermal-to-electric converter (AMTEC) is established to simulate flow and heat transfer characteristics in capillary porous wick and liquid channel by solving the mass and heat transport controlling equations. The effects of the working fluid flow rate, inlet temperature, porous wick thickness, porosity and effective pore diameter on the distributions of pressure, velocity and temperature are analyzed. In addition, the available effective pore size of the porous wick and the measures to improve the performance of the porous wick are given by analyzing the relationship between the maximum available capillary pressure and the loop pressure drop. The results show that the model presented in gives a good agreement with the three dimensional two-phase evaporation model. The flow and heat transfer characteristics of the capillary porous wick with the alkali metal liquid as working fluid are different from that with the traditional working fluid in some ways.

Abstract:For the core problem of ground safety control—the relative criticality estimation of ground protected objects in the rocket launch process, the relative criticality algorithm of ground protected objects is proposed in the paper. This algorithm transforms the measurement of the relative criticality for ground protected objects into cost function which considers the rocket’s current fall point，the distribution of rocket’s wreckage and poison gas, the population and the important establishments of the objects, realize the comprehensive evaluation of the relative criticality for different objects. To verify the effectiveness of this algorithm, it is applied to a decision support system to achieve the quantitative evaluation of the ground protected objects in several rocket launching tasks. This algorithm provides quantificational judgment evidence for rocket safety control officers in effective decision- making for safety control of the rocket launching.

Abstract:Aiming at the low accuracy and low adaptability of wave detection, a QRS complexes detection algorithm is proposed based on quadratic b-spline wavelet, while combined with binary search algorithm and arc approximating curve algorithm. The signal is decomposed with quadratic b-spline wavelet through Mallat algorithm and the R wave is detected by adjusting the threshold with binary search and modulus maximumizing. The T wave and P wave are detected by using arc approximating curve algorithm based on the least square. This algorithm is certified with the ECG signals from MIT-BIH database and is demonstrated that the algorithm enhanced the adaptability of R wave detection and improved the accuracy of T wave and P wave detection. The simulation experiment shows that the improved algorithm can effectively improve the automatic detection capabilities of ECG signals.

Abstract:A new image denoising algorithm based on the complex direction of filter bands and BlockShrink is proposed. The image is decomposed based on the complex direction of filter bands to obtain the coefficients. Then, according to the coefficient correlation, the block threshold method is used to select the best block size and the threshold. In this way, the unbiased risk estimation of each sub-band is minimized. The algorithm is entirely data-driven easy to implement and with good visual effects. Experiments show that the proposed algorithm increase the PSNR by 0.6 percent compared with the algorithm based on DWT-BlockShrink transform, and the edge and countour information are more clearly.

Abstract:To track the non-stationary dynamics of the process which contains time-varying and multi-scale data, an online moving window multi-scale principal component analysis（MW-MSPCA） data-driven-based fault diagnosis method is proposed. In this data-driven diagnosis technique, wavelet threshold denoising is used to solve the conflict between the statistical model deviation and data correlation decreasing. The statistical models are updated by using moving window principal component analysis in various scales. The contribution of individual process variable to the process behavior change is illustrated in a 3-dimensional contribution chart. A quantitative evaluation mechanism is also given to evaluate the diagonising accuracy. The numerical experimental results for 6135D diesel demonstrate that the proposed method can diagnose sensor fault better in terms of false rejection, false alarm and diagnosing accuracy for fault diagnosis upon comparing with conventional multi-scale principal component analysis（MSPCA） and adaptive multi-way principal component analysis（AMPCA） modeling.

Abstract:The traditional Hash functions use a chain-like structure, which can not make best use of the 2D property of graphics or images. The chain-like structure is low in efficiency when implemented on a parallel computing platform. A new structure of Hash function is proposed to overcome these shortcomings and the time complexity is as low as o(logn) on a parallel computing platform. Some fundamental problems regarding the structure are analyzed. With this structure, a Hash function based on cellular neural network is proposed, which shows satisfactory randomness sensitivity to input and resistance to collision with simulation experiments.

Abstract:Abstract：The single-node energy detection has the drawbacks of low accuracy and “Hidden terminal”, while the cooperative spectrum sensing algorithms usually use equivalent weights for data fusion instead of considering the influences to the detection performance resulting from the communication environment of different nodes. In order to solve these problems, a novel weighted cooperative spectrum sensing algorithm is proposed. The proposed algorithm is based on the double-threshold energy detection. According to the relation between the single-node dual-threshold setting and the node perceiving performance, the single-node dual-threshold relative distance is used as a credit for weighted cooperative data fusion. The simulation result proves that, compared with the single node double-threshold energy detection and the cooperative spectrum sensing algorithm based on OR-rule, the proposed algorithm can achieve reliable sensing performance with low SNR.

Abstract:An efficient and secure mobile IP registration protocol is proposed, which is based on certificateless public key signature scheme without pairing to minimize the registration time. Vser anonymity is achieved via the temporary identity (TID) transmitted by the mobile user, instead of the true identity. Additional replay protection is included by introducing Nonce in the registration message to prevent a possible replay attack. Security analyses demonstrate that the new scheme is both secure and efficient. Numerical experimental results and security performance analyses show that the new scheme outperforms the existing ones regarding the registration time and computational load while improving security.

Abstract:Orthogonal frequency division multiplexing (OFDM) is sensitive to the in-phase and quadrature-phase (IQ) imbalance induced by the direct conversion architectures. A compensation scheme of IQ imbalance exploiting null subcarriers in OFDM symbols is presented. The proposed algorithm is with high bandwidth utilization because the training symbols are not required. The effect of IQ imbalance on OFDM systems is studied, and the mirror relationship between the FFT of a sequence and that of its conjugate is employed to estimate and compensate the IQ imbalance. This method can be applied to multiple input multiple output (MIMO) OFDM systems with space time block code (STBC). Performance analysis shows that the proposed algorithm is asymptotically unbiased. The variance is inversely proportional to the number of OFDM symbols, null subcarriers, the SNR and the channel frequency response, and proportional to the IQ imbalance. Simulation results demonstrate that this scheme can obtain almost the optimal bit error rate (BER).

Abstract:Considering traditional current protection cannot satisfy the micro-grid, a system protection solution for the micro-grid is proposed. In this solution, the failure message with direction information can be exchanged among the adjacent protection units, so the fault coverage can be determined and the fault can be quickly cleared. By analyzing the movement of the protection in three kinds of fault conditions in the micro-grid that contains three branches and two micro-power based on inverter, the method has been proved that the fault can be quickly cleared and the protection has the same protection strategies for both islanded and grid-connected operation.

Abstract:The ordinary gasoline engines could not be fueled by high-blend methanol directly. A MCU-based high-blend methanol gasoline control system is designed to extend the injection pulse width. PROTEUS simulation and test bench are validated. Flyer M-TCE engines burning M85 go smoothly. The results indicate that the high-blend methanol gasoline control system caneffectively control the engine injection mass without changing the original Electronic Control Unit , and make it feasible to apply high-blend methanol gasoline to the ordinary gasoline engines.