Abstract:To deal with the problems of safe thickness at the end of the pile in Karst areas, the Hoek-Brown rock mass strength criterion was introduced, which considered the influence of rock mass quality and triaxial stress. The formula of rock mass tensile strength was confirmed，and a practical formula of rock mass shear strength was established by the use of Lambe transformation. Then, the computational method of the safe thickness of the rock mass at the end of the pile was determined on the basis of the failure mode of the rock mass at the end of the pile. Parametric analysis has shown that the Rock Mass Raling(RMR) value has a strong effect on safe thickness. The higher the RMR value, the smaller the safe thickness and the greater the contrast. For the general state of the natural homeostasis of the Karst cave roof, a safe thickness value 3 times the pile diameter is reasonable. Finally, a sample project was carried out to verify this calculation method.

Abstract:In order to predict the buoyancy-driven flow and temperature fields influenced by coupling factors in residential buildings with atrium, the Multizone and Zonal methods were adopted to partition the building into zones. The prediction model of the loops between apartments and the atrium was established by means of mass, momentum, energy conservation equations. Furthermore, a reduce-scale model of 1/25, calculated by the similarity criteria of Archimedes number, was conducted to validate the accuracy of the prediction model. The calculated result of the prediction model agreed with the experiment data, which shows that the thermal environment in residential buildings with atrium can accurately be predicted with this prediction model.

Abstract:full-scale moveable instrumented low-rise building was constructed and implemented to measure the wind velocity and the associated building surface pressures during typhoon landfalls. The major objective of the field study was to further understand the typhoon-generated wind characteristics and the wind effects on the low-rise building under extreme wind conditions. Based on the pressure data measured on a roof corner of the experimented building during the 0801 typhoon Neoguri, it was shown that high local suctions were observed under the oblique flows, the pressure distribution and the cross-correlation coefficients between various taps of a roof corner area. The observed minimal pressure-coefficients were higher than those recommended for the design of the corner zone by current design building codes. The Generalized Extreme Value (GEV) distributions were used to fit the peak suction pressure coefficients,and it was found that the Type III Extreme Value distribution matched the data well. It was revealed that the predicted upper limits of the peak pressure coefficients were more than 20% higher in magnitude than the highest values actually measured. Compared with those obtained under non-typhoon wind climates, the corner section of the roof experienced higher local suctions during typhoons.

Abstract:In order to research the dynamic performance of a railway bridge with bidirectional lead rubber seismic isolation bearings under train load,a three spans bridge was established with ANSYS. The coupling vibration mechanism was studied between bridge and train. The results show that, the transverse displacement increases with the isolation period of transverse increase. The bearing damp attenuates the horizontal vibration and has little action on the tensional and vertical displacement. The transverse wiggle, side rolling and vertical displacement change little with the transverse seismic period increase. The bearing damping has little influence on the transverse wiggle, side rolling angle, shaking angle, up and down displacement, nodding angle displacement and acceleration response of each degree of freedom.

Abstract:Gravity casting experiments were carried out using A356 aluminum alloy. Based on the experimental results, the Interfacial Heat Transfer Coefficient (IHTC) between the casting and metal mold was identified by using the method of inverse analysis combined numerical simulation and optimization. The variation relation of calculated IHTC with interfacial temperature was discussed. The results show that an obvious change for IHTC can be seen when interfacial temperature is at 545~555 ℃ and whereas it remains at a constant value liquidus and under 545 ℃. The IHTC value is about 3 000 W?m-2?K-1 over solidus curve and about 500 W?m-2?K-1 under 545 ℃ respectively. And the approximate mathematics model was also established by the linear regression analysis. The model of IHTC is a function with the change of interfacial temperature between the casting and metal mold. In addition, a good agreement was obtained between the simulated and experimental temperatures by applying the identified IHTC，so that the inverse analysis method could be verified to be available and accurate.

Abstract:With sliding interface and moving mesh technique provided by STAR-CD software, the 3-D transient external flow field around two vehicles passing each other was simulated. The tendency of changing drag and side coefficient was provided. By analyzing the pressure distribution and velocity vector on some sections, the reasons for the tendency and transient aerodynamic characteristics were concluded. The data shows: in the case that two cars which have the same volume and shape pass each other, the tendency of changing drag coefficient is similar to negative sinusoid,and the side coefficient has three peak values;But in the case that a car and a container truck, whose volume and shape have huge differences, pass each other, the tendency is more complicated and intense.

Abstract:An accurate nonlinear contact analysis model was established by using finite element method for a pair of spiral bevel gears of the tail reducer of a helicopter. Based on this model, dynamic meshing simulation was carried out in a meshing period. The performance of tooth contact fatigue and tooth root bending fatigue was studied. The regular pattern indicating the variety of tooth surface contact stress and tooth root bending stress with different meshing positions was presented. Then this paper analyzed the contact fatigue strength and the bending fatigue strength，and it was suggested that the major region of the fatigue damage was located in the side of tooth root compressed from the cloud figure of fatigue lifetime distribution. Finally, this paper obtained the node of tooth root bending fatigue life in the damage region before and after carburized machining.

Abstract:Data stream is characterized by the continuous arrival of data, the unpredictability of the time of concept drifts and the uncertain number of concepts, making it difficult to predict the size of the window in advance, but the number of concepts in the window affects the detection of concept drifts. This paper proposed an algorithm for the fast detection of concept drifts in data streams by taking a confident majority voting strategy (CMV_SEA). This algorithm replaced base classifiers in a window like SEA and used majority voting strategy to ensemble all base classifiers in the window. The experiment results illustrate that CMV_SEA can promote prediction accuracy and detect concept drifts as soon as a new concept comes up, and its ability to detect and learn a new concept is not influenced by the size of the window.

Abstract:A prediction model for time series was introduced, which uses the hybrid algorithm to optimize the neural networks. The main idea was to build the new hybrid algorithm by combining particle swarm optimization with Simulated Annealing in sudden jump, and then to optimize the neural networks with this hybrid algorithm. Therefore, many shortcomings, like the slow convergence of common neural networks, partial optimization and the prediction precocity of simplex particle swarm optimization, were overcome. In addition, in order to prove the validity and the value of the model, the Mackey-Glass chaotic time series and the Henon map were simulated. The results have shown the fast convergence, good stability and the high precision of this model.

Abstract:A mathematical model was built on the principle of the three-phase to four-phase impedance matching balance transformer and the theory of multi-wiring transformer. Meanwhile, the performance characteristic of the transformer under different loads was analyzed. The transformer applied in AT traction power supply system wiring scheme was presented,and its electrical characteristic of wiring scheme was discussed. The research has shown that the impedance matching transformer can not only realize the balanced symmetrical conversion of three-phase to four-phase, but also has an obvious superiority in restraining the negative sequence current caused by the lopsided load.

Abstract:In the ceramic industry of China, a large mount of ceramic manufacturers have preselected and fine-grinded the raw materials before application in the production process. Hence, instead of breakage function, the dispersion ability of the slurry preparation equipment begins to play a key role to influence the ceramic slurry preparation efficiency. A new method to prepare the ceramic slurry with basket sand mill was promoted. In this work, α-Al2O3 powders for making ceramic slurry with basket sand mill was tested and analyzed. Laser particle analyzer and quanta 200 (FEI) were used to characterize the particle size distribution and microscopy, respectively. Furthermore, the authors studied the relationship among the particle size, grinding time, grinding bead diameter and stirrer speed experimentally and theoretically in the ceramic slurry (α-Al2O3) preparation process. The most drastic decrease of α-Al2O3 particle size was achieved by combination of ZrO2 grinding bead 2.2 mm with stirrer speed 2 500±10 r/min, and after the paricles were grinded for D50 reaches 1 μm.

Abstract:The lithium-ion battery cathode material LiFePO4 doped by Er3+ was synthesized through solid-state reaction. The X-ray diffraction analysis, four-probe method, electrochemical impedance spectroscopy and galvanostatic charge and discharge performance testing were used to study the position and the quantity of doping on the crystal structures, electronic conductivity and electrochemical performance of the samples. The results have shown that the effect of doping on Fe-site is better than Li-site. The Er3+ dope of less than 3% does not affect the crystalline structure of the material but changes the microstructure of the samples when the electronic conductivity increases by four orders of magnitude. The discharge capacity of the sample is 103.47 mAh / g at the rate of 1.0 ℃, with an increase of 22.28% over the undoped samples. The doping of Er3+ improves its specific capacity, cycling and rate electrochemical properties.

Abstract:The interaction of allethrin and tetramethrin with single strand DNA (ssDNA)，double strand DNA, guanine and guanosine was studied by means of UV and fluorescence spectrophotometry. Pyrethroid Pesticide brought about a hypochromic effect on the UV absorption spectrum of DNA, but the maximal absorption wavelength of DNA did not shift obviously and the addition of varied concentration of DNA caused the fluorescence quenching of pesticides. The effect of ionic strength and KI on the system of pesticide-DNA and the effect of pesticide on the neutral red-DNA were investigated. The results have indicated that the electrostatic binding and the groove binding are the two major modes of the interaction between allethrin and DNA, while electrostatic binding mainly exists between tetramethrin and DNA. The spectra of UV and the fluorescence of Guanine and guanosine interacting with pesticides have proved that the interaction between them and pesticide is chiefly hydrogen bonds, and guanosine interacts more strongly with pesticides than guanine does.

Abstract:A new difunctional fluorene-based benzoxazine monomer was synthesized through the reaction of 9,9-bis-(4-hydroxyphenyl)-fluorene with formaldehyde and cyclohexylamine. The chemical structure was confirmed through FTIR, H NMR and 13C NMR analyses. The polymerization reaction of the precursor was monitored with Differential Scanning Calorimetry (DSC) and FTIR. The thermal properties of cured polymers were evaluated through DSC and Thermo Gravimetric Analysis (TGA). The fluorene-based polybenzoxazine showed that the typical curing characteristic of the oxazine ring-opening for difunctional benzoxazine centred at 251 ℃, with remarkably higher glass transition temperature (189.4 ℃) and better thermal stability than traditional biphenol A polybenzoxazines. The thermal decomposition temperature (5% weight loss) and the char yield of fluorene based polybenzoxazine at 800 ℃ is 329 ℃ and 31%, respectively.

Abstract:To overcome the vital shortcomings of traditional BDI Agent in the application of VO, we proposed a Policy-Oriented Autonomic, Controllable Agent Model. To enhance the controllability of the Agent, a policy was used to restrain the formation of Agent motivation and to affect the formation of their intentions and behaviors. This model used a hierarchical policy structure, with different policies representing the interests of different partners in the VO. In order to solve the conflict between individual interests and organizational objectives, the policies were divided into two different layers of organizational policy and individual policy. By using extended Defeasible Logical framework, we established a formal theory for the model with linear time computational complexity. This model maintained a certain degree of autonomy and at the same time enhanced the controllability at the organizational level.

Abstract:Considering the reliability and power consumption problems of (Field Programmable Gate Array)FPGA in aviation and spaceflight application, a new design method of low power and fault-tolerance finite state machine suitable for FPGA has been proposed. Different from traditional occupying routing resources, looking up tables and registers, this method was realized by mapping finite-state machines into the embedded blocks RAM of FPGA and employing two RAM blocks to compose the duple-redundancy structure to confirm data errors in RAM by comparing the consistency of the two blocks RAM output data and combining the parity check for error detection and correction. The experiment results have shown that this method has the advantages of lower power and higher reliability, and can achieve an error on-line error correction, compared with traditional triple-redundancy methods

Abstract:By means of the time-discretization approach, a stochastic difference equation from the geometric mean-reversion process was derived, and then a nonlinear regression model was established. In this way, the distribution and estimation for each parameter were obtained with Bayesian inference. Monte Carlo simulation results proved the effectiveness of this model. Lastly, the one-step forward forecasting was performed for the daily data of YEN/RMB by means of three models:ARMA-GARCH model, nonlinear ARI model and geometric mean-reversion model. The results have shown that the geometric mean-reversion model is a bit better than the nonlinear ARI model but much better than the ARMA-GARCH model.

Abstract:Adopting Seemingly Unrelated Regression (SUR) analysis method, which can discuss a wide range of interrelated models simultaneously, this paper took rural residents' income and consumption panel data, which includes 31 provinces and cities from 2000 to 2006, as its research objects, and analyzed the impact of wage income, household operational income, property income and transfer income on seven major types of livelihood consumption. The regression results have shown that wage income has a great effect both on rural housing expenditure and on cultural and educational entertainment supplies expenditures; household operational income significantly affects the rural consumption of food, clothing, transportation and communication, medical and health care items; transfer income is the main driving force for peasants to consume household appliances and services.