Abstract:A model of a built-in children restraint system was set up. The method of coupling between MADYMO and LS-DYNA was used in simulation and a sled test was adopted to validate this model. First, side impact simulations were carried out respectively for vehicle seat without armrest, with different types of armrests and the combination of armrest and lateral flank. Then, an analysis of the influence of the different heights of armrest for children was done through other side impact simulations. Finally, the simulation results were analyzed. The results show that the armrest can prevent the child occupant from slipping out of the seat cushion so as to avoid suffocation death caused by neck bridled, while lateral flank can protect children's neck and chest effectively. Vehicle seat with the combination of lateral flank and armrest can provide the best protection for children in all types. The results also show that the seat with moderate armrest height can provide the best protection for children.

Abstract:We presented a skeleton-driven model deformation method for the effective reuse of finite element (FE) models in auto-body structural analysis. Skeletons were defined to describe the body structure and control blocks embedding the body structure based on the geometry of the given FE model. Then, the constraint between the skeleton curve set and control blocks of the given model were established so that the user can derive the desired shape of control blocks by editing the skeleton curves. Finally, the deformed FE model was reconstructed by using the spatial deformation method. Numerical experiments show that the proposed method can obtain physically plausible deformed results and achieve the effective reuse of the given FE models. In addition, using skeleton curves as the handles can provide users with an intuitive way to manipulate FE models.

Abstract:A new special machine tool for the precision riveting and assembly of the automotive hub bearing unit was proposed, which could adjust the inclination angle of the rivet tail, real-time measurement of the riveting and assembly force and displacement of the stage, and automatic precision adjustment of stop position of the riveting and assembly. Its parameters, such as the inclination angle of the rivet tail, feed, riveting and assembly force, were theoretically analyzed and the prototype was manufactured. Experiment results show that it has a maximum axial riveting and assembly force of 30 T. The positioning precision of the stage is less than 2 μm and the production efficiency is up to 3 000 pieces per shift. The theoretical reliability of the hub bearing unit produced by the special machine tool is above 300 000 km. It satisfies the assembly requirement of the automotive hub bearing unit.

Abstract:This paper presented the prototype of a buckling plate vibration isolator with the propitious characteristic of quasi-zero stiffness (QZS). The isolator was devised by combining a rubber pad with a buckling steel plate. To facilitate the analysis of the characteristics of the QZS isolator, an approximate expression of force and displacement was formulated on the basis of Abaqus analysis and Matlab tool. Analytical result reveals the stiffness criterion of the supporting rubber for the QZS system. The force transmissibility of the vibration isolation systems was derived in the harmonic balance method (HB), and the effects of the damping were investigated for the performance evaluation of the systems. The results show that the QZS isolator can outperform the linear system in low frequency domain, and there is no involvement of resonance when damping is set properly.

Abstract:In order to investigate the thermal load distribution of modified piston, it is necessary to analyze temperature field and thermal stress combined simulation with experiments. The FE software was used to simulate the temperature field of the piston after the boundary conditions of thermal transfer were calculated, and then, the results were verified according to experiment data, and the error of calculation was less than 5%. Finally, temperature field and thermal stress were derived under different operating conditions including conditions A and B. The results of investigation show that the maximum temperature and maximum value of thermal stress of modified piston decrease compared with the original piston. The modified piston meets the demand of thermal load based on the original piston meeting the demand of thermal load.

Abstract:The laser welding test was carried out on the 5083 aluminum alloy with thickness 1.0 mm and the 6016 aluminum alloy with thickness 1.2 mm. The relationship between plasma MgI spectrum signal and the process parameters as well as welding quality were studied by testing the MgI singal of laser welded dissimilar alloy and by analyzing fracture morphology,microhardness and mechanical properties in the joint by using spectroscopic measurement system, scanning electron microscope, vickers microhardness machine, and computer control electronic universal testing machine. The results show that, with the speed increasing, MgI spectrum signal strength is reduced; the focus obviously affects MgI signal while the laser power changs the whole MgI signal amplitude slightly. When MgI relative strength appears smaller or larger, the specimens have lack or over welding; MgI plasma with strong fluctuations leads to defects such as porosity and low mechanical performance while smooth MgI signal has less defect and good mechanical performance. The real-time control welding process X -Rs is established based on MgI spectral signal corresponding to the quality of weldment and Hugh hart SPC control theory.

Abstract:To improve the solution efficiency and accuracy of the fracture parameters, the smoothed finite element method-virtual crack close method was proposed based on the combination of these two methods. The fracture parameters of the composite material circular plate with different length and angle oblique cracks were solved, and the result was compared with that of the finite element method-virtual crack closure method. The calculation result confirms that this method has advantages of high accuracy, no special treatment on the elements at crack tip and less mesh resolution requirement. This method is simple but efficient for the calculation of fracture problems.

Abstract:To extract the damage sensitive features directly from the vibration response, a damage identification method based on the wavelet packet decomposition-local mean decomposition and the permutation entropy was proposed, without requiring the exciting force. The wavelet packet decomposition was applied to decompose the original vibration signal into a set of narrow band signals, and then, the local mean decomposition method was used to decompose the narrow band signal, which can extract the low energy components effectively. After that, the permutation entropy was obtained to detect the structural damage. The relative permutation entropy between the test data and the sample data was obtained to identify the damage pattern. The experiment results show that the proposed method can be used to identify the structural damage effectively.

Abstract:In system state recognition and prognostics, state transition probability matrix of hidden semi-Markov model (HSMM) is constant and the predicted life value shows stepladder change, which is different from the actual residual life of the system. To solve this problem, an HSMM with time varying state transition probability matrix was proposed. Based on the analysis of three typical degradation states of the system, three different state transition coefficients were given. Combined with initial state transition matrix, a time varying state transition matrix was obtained, the estimation accuracy of residual life of the system under current healthy state was increased, and a more accurate overall residual life prediction value can be obtained. Experiment results show that, compared with traditional HSMM, HSMM based on time varying state transition probability matrix can increase the accuracy of residual life prediction and can be used in life prediction with high precision.

Abstract:A novel power quality conditioning system based on the YN_ balance transformer to improve the power quality, such as negative sequence, harmonic and lower power factor in electric railways with AT or direct power supply, was proposed. The system fully uses the potential of the traction transformer secondary side with three-phase system, and it integrates the three-phase full-bridge active power regulation system with the main transformer omitting step-down transformer. The composition method of the system, the principle of the compensation of the negative sequence and harmonic and reactive power were described. The current detection and control methods were also proposed. According to the actual parameter and measured data in a substation, a system simulation model was built. The results indicate that the proposed system has excellent performance in the compensation of the negative sequence, harmonic and reactive power.

Abstract:In order to realize the LVRT of the PV power system by using supercapacitor energy storage during the grid voltage drop, the active power reference of the DPC according to the grid voltage sags are given, at the same time by controlling the bidirectional DC/DC converter with voltage and current dual loop, the DC side of excess energy stores in supercapacitors, in order to balance the power on both sides of the inverter and to maintain the DC bus voltage. The proposed scheme is proved to be feasible and effective in MATLAB/Simulink.

Abstract:Up to now there has been no special monitoring equipment or platform for the energy efficiency measurement of large power rectifier system. For this reason, a new method of energy efficiency measurement of large power rectifier system based on the fiber optic Ethernet communication was presented. In order to prove the advantages of the new method, this paper made a comprehensive and comparative study of the measuring principles, and the analytical method of energy efficiency. The method of indirect inversion of heavy direct current proves to be correct and can be well applied in practical projects through simulation and experiments. Finally, by combining with engineering practice, the specific implementation process of the new analytical method of energy efficiency was described. The project case indicates that the efficiency analytic method can correctly calculate the efficiency of the power-supply system of the industrial rectifier system, and can provide a proof of improving the efficiency of the equipments and saving the energy of the system.

Abstract:This paper took the actual 110 kV high-voltage coaxial GIS as the research object. Its mathematical model and 3D magnetic-thermal coupled finite element model were both established, and then, the electromagnetic field and eddy current field were analyzed. In order to analyze the influence of the shell eddy current loss on GIS thermal distribution, the thermal distributions under the two conditions of taking and not taking the shell eddy current loss were calculated by combining the classical heat transfer theory. The simulation results indicate that the thermal distribution is not uniform because of air convention, and the thermal distribution has the characteristics of bilateral symmetry and from top to below. The highest local temperature rise point is at the top of the GIS busbar. The shell eddy current loss has some effect on the thermal distribution, but the temperature rise difference is in 0.5 ℃. Therefore, the research work can provide important reference for the design and check of high-voltage GIS.

Abstract:In order to accurately detect the parameters of harmonics in the power system, an algorithm based on a method of spatial spectrum estimation named Toeplitz was proposed on the basis of the essential property of noise information. First, eigen-value decomposition was used for the autocorrelation of matrix constructed by sampling data to get signal sub-space and noise sub-space. It adopts the principle of least squares method and rotational invariance techniques to calculate high precision signal parameter flicker .Finally, based on the estimated frequency of every signal component and the characteristic of zero average value of noise signals, the simulation results and the real-time data analysis have verified the effectiveness of the algorithm，which satisfies the needs of practical application.

Abstract:A high frequency complex Gm-C filter was proposed by using 0.18 μm CMOS RF process. The filter has 20 MHz bandwidth and is centered at 46 MHz, while the pass-band flatness is less than 0.36 dB. The image band rejection is higher than 98 dB, and the out-band rejection is higher than 28 dB. The complete filter consumes less than 7.9 mA with 1.8 V supply voltage. An integrator with digital circuits based frequency tuning circuit was used to realize the automatic tuning of both center frequency and band-width. On the completion of the tuning, the circuit will automatically shut down. The 'zero power' is particularly suitable for low power applications. Simulation results show that the tuning error is less than ±1.5%.

Abstract:The transmission characteristics of the structure of defective rectangular ring resonator based on metal-insulator-metal waveguide were investigated in the finite difference time domain method. This structure consists of a waveguide channel and a defective rectangular ring resonator，which is parallel to the waveguide．Compared with the perfect rectangular ring resonator, the structure with defect destroys the symmetry of the resonant modes in the resonator, which results in a novel filter function of the complex resonator. The effective length of the structure depends on the size of the defect, so filtering wavelength can be tuned by adjusting the dimension of the defect. The numerical simulation results are essentially in agreement with the transmission line theory calculation results. In addition, the coupling strength between the waveguide channel and defective rectangular ring resonator is dependent on the defect location, which is useful in the control of the transmittance at filtering wavelength. Compared with the other filtering structures, our structure can realize more broadband segment filtering, effectively adjust the filtering wavelength and control the transmittance without changing the overall size. When the size of detect is chosen on a certain value, a new double degenerated mode appears, which improves the filtering properties of the structure. It has potential application in integrated optics due to its miniaturization and simple fabrication process.

Abstract:This paper presented an approach which combines space division and rules compression in an effort to allow the real-time updates and TCAM chips storage happening at the same time. In the approach, the TCAM chip was divided into two partitions, a real-time update area and a compression storage area. The former was assigned in the front of the chip for storing real-time updating rules sent by the controller, and the latter had the function of compressing and storing rules generated by the server within certain time period. We made a comprehensive analysis of the space division ratio and conducted simulation experiments on the rules generated by the ClassBench tool. The experiment results have demonstrated the effectiveness of the approach.

Abstract:To solve the problem of epistasis analysis in genome-wide, a filter method based on multiple criteria fusion was developed to remove the unrelated SNP loci. After that, ant colony algorithm was used to construct the SNP set with epistasis interaction. In the phase of constructing, a support vector machine was proposed to build the relationship between the SNP set and complex diseases. The experiment results show that, with multiple criteria evaluating each SNP and ant colony optimization, the prediction accuracy and running time have been improved, making it better than conventional methods.

Abstract:The image features of copper flotation froth image means the size of the area of local black hydration in the froth image, which is called local spectral feature and related to flotation performance. A local spectral feature extraction method based on MPCA was proposed for the irregularity of the size and the shape, and the extracted features were used in copper rougher flotation process to identify sick conditions. Firstly, we described the copper rougher flotation process and analyzed the impact of the main factors roughing process and the formation mechanism of black hydration region. Then, a method was proposed to extract the local feature of image based on MPCA. Lastly, the image local feature extraction algorithm based on MPCA was applied to the copper flotation rougher froth image and the extracted image features were used in copper rougher process for sick condition recognition. The validity of the proposed method has been verified with industrial data.

Abstract:Aiming at problems in authentication methods of mobile devices, such as being easy to crack or difficult to implement or high costs, this paper presented a new mobile phone acceleration sensor authentication method on human perception. To use the current widespread acceleration sensor in mobile phones to capture human motion data (typically dynamic gesture), we proposed an authentication algorithm named Window Limited Approximate Longest Common Sequence (WLALCS) based on the classical matching algorithm LCS. And we implemented an authentication system on cloud computing model. Compared with the existing gesture and accelerometer based authentication methods, this method effectively reduced the equal error rate on imitate action attack. Non-imitate attack authentication EER (Equal Error Rate) is 2%, and imitate attack authentication EER is 5%. This system is easy to deploy on any smart phone systems and does not need any additional sensors. Based on the biological characteristics, we reinforced the robustness towards mimicry attack.

Abstract:To solve the problems of security and privacy caused by RFID tags search process, a lightweight service-less RFID security search protocol was designed. Firstly, through strict timestamp, the time permissions of the mobile reader were managed. Secondly, the method of combining loose timestamp and HASH function for the safety protection of the wireless channel was put forward, the one-way character of HASH function was used to ensure the integrity and confidentiality of interactive messages. Finally, the collision thought was made use of to realize the adjustable intensity of privacy and search efficiency. Under the UC framework, it was proved that the protocol could meet universally composable security, enabling the protocol to run in the concurrent environment. Under the standard security model, it was proved that the protocol could effectively resist replay attack, de-synchronization attack, track attack, anonymity attack and so on. It follows that the proposed protocol has strong security and privacy.