Abstract:Based on the wind-tunnel test of the rigid model of Jilin Railway Station, the contours of the mean and fluctuating wind pressure coefficients were presented and discussed. Analyses of the characteristics of the wind pressure distributions were conducted. It was found that negative pressures (suctions) occurred on the long-span roof in general, high negative pressure coefficients occurred on the eaves, cantilevered roof and the bulge part of the roof on the main station building on the windward, and relatively smaller suctions occurred on the railway platform awning because of the open surrounding configurations there. These conclusions will be useful in the wind-resistant design of long-span roof structures with complex shapes.

Abstract:In order to improve the bearing capacity, geotechnical engineers often take geosynthetic-encased measures at the top of the gravel pile. In order to analyze the influence on the ultimate bearing capacity of geosynthetic-encased gravel pile based on the column cavity expansion theorem conside the influence of the soil gravidity stress, the radius of the plastic zone and the bearing capacity calculation method were deduced when Mohr-Coulomb yield criterion was adopted. A new calculation formula based on the model, which considered the expansion overlapped between pile groups, was established. In order to validate the proposed method, a case history was illustrated. The result has indicated that these formulas are practical.

Abstract:For long-span bridges on gorge terrain, the determination of wind characteristics prevailing at bridge deck level may be a challenge. In this paper, a large bound of topography at bridge site was first obtained in Google Map. Then altitude data on discrete points of interest was extracted by Autocad. Finally, Imageware was employed to form a terrain surface. With a computational domain built with the terrain surface included, the wind field at the bridge site was numerically simulated with Reynolds-Averaged Navier-Stokes equations and the standard turbulence model. Considering different incoming wind conditions, wind characteristics on the bridge site, such as wind profile, angle of attack, as well as yaw angle along the bridge axis were determined. Also, the wind flow along the gorge can be visualized, which provided a direct insight for wind environment. The present method provides an effective approach for wind parameters on a wide range of complex terrains.

Abstract:Most international codes and standards provide guidelines and procedures for assessing the along-wind nominal value of equivalent static wind loads on tall buildings. Despite their analogous multiple-parameters expression, notable scatter exists among the parameters and so among the nominal values of wind loads and wind effects predicted by the various codes and standards. Based on the comparative study of parameters, the GB50009 (China), ASCE7 (American), and AIJ (Japan) were selected as the representative codes in the Asia-Pacific region, and the calculation principles and methods of the nominal value of equivalent wind loads in the along-wind direction were reviewed. Parameters such as the basic wind velocity, wind profile, turbulence intensity, gust effect factor and also the inter-influence among them were considered. The gust effect factor and the influence on it were also expounded. A detail example including three representative buildings was presented to illustrate the overall comparison and the main findings were also highlighted in the example and the relevant discussion. The results show that the along-wind nominal value of equivalent static wind loads is the largest in AIJ and more or less the same in GB50009 and ASCE7.

Abstract:Firstly, the reclaimed asphalt pavement was detected, and further mixing proportion of asphalt mixture AC-20/AC-25 by central plant hot recycling was designed. Secondly, the compressive strength and the compressive resilience modulus of the mixture with different RAP percentages were tested with pressure machine and MTS-810 respectively at 15 and 20℃. Next, the change laws were analyzed and the value ranges were recommended. Finally, structural analysis and evaluation were carried out for overlaid asphalt pavement and perpetual pavement by central plant hot recycling with LSPM so as to demonstrate the technical feasibility of the mixture used as structural layer of surface course in pavement structure with LSPM. The studies have suggested that, for overlaid asphalt pavement by central plant hot recycling with LSPM, the compressive resilience modulus of the recycled mixture needs testing in design and the tensile stress at the bottom of recycled structural layer needs checking according to specifications. Moreover, the application of recycled mixture in perpetual pavement with LSPM can satisfy the design control indexes.

Abstract:For the direct dynamic simulation of unmanned aerial vehicle (UAV) net-recovery system, the modeling methods of key components such as flexible belt and damper were discussed. The finite element model of UAV net-recovery system was developed based on LS-DYNA, and the system dynamic simulations in several different impact locations were conducted. The finite element model was valid judging from the experiment results. The simulation and experiment results have shown that this system has a good engineering adaptability and the modeling methods are universal to certain extent.

Abstract:For the purpose of achieving the lightweight of automobiles, the contact friction process between the taper leaves was deduced with equations such as the deformation equations and stress equations, which were based on the taper leaf spring of the mini-car. Based on the genetic algorithms, a mathematical optimal model of the two taper leaves spring with variable stiffness was built to simulate in the software of MATLAB. A FEM model of the leaf spring was also built to check the mathematical model by using the ANSYS. In conclusion, it has been found that the grams of the material can be reduced by 31.6% without affecting the performances of the requirements, by comparing the difference between the optimal test results and non-optimal test results.

Abstract:A nonlinear dynamic model of fiber optical current transformer (FOCT) was deduced on the basis of physical model with reasonable equivalent approximate. The nonlinear model was simplified to linear discrete model, and simulation analysis was carried out. Based on the characteristic of noise, a random noise model was established. Then, the random noise was simulated in different stochastic processes. Simulation results show that the model is reasonable, and the random noise generated by simulation can reflect the statistical characteristics of noise in optical fiber current transfer.

Abstract:In order to analyze the robust stability of π -type inductive power transfer system, a generalized state space averaging (GSSA) model based on frequency domain resolving method was first built. An uncertain model was then represented as a linear dynamic system with perturbation feedback, which took into account the frequency uncertainty by separating the object into nominal part and perturbation part with the method of linear fractional transformation. The μ method based on the structure singular value was used to analyze the effect of frequency perturbation on system stability as well as the maximum perturbation allowed for maintaining system stability. The simulation results have verified the accuracy of the μ theory analyses.

Abstract:The exact evaluation of the condition of large power transformers is an important research subject in electrical engineering field，and the key task is to assess the operation condition of power transformers based on state parameters．However, the exact assessment result has not been acquired until now according to traditional assessment methods．A new assessment method based on the Analytic Hierarchy Process was proposed in order to overcome the disadvantages of traditional condition assessments based on "acceptance" or "overproof"．Firstly, the equipment state and its evaluation hierarchy model were analyzed. The health value was employed to quantitatively describe the running state degree of power transformers, and the weight vectors of all evaluation hierarchies were discussed by using the analytic hierarchy process methodology with the experiences of experts. The valuation model for power transformer's health state based on the analytic hierarchy process methodology was built. The practical operational results have shown that the proposed assessment model and method are correct and effective.

Abstract:Under the constraint condition of vertex coverage, a probe station deployment method supporting multiple fault localization was proposed, which aims at minimizing the number of probe stations. This method is based on the traditional k -path algorithm, and uses an improved algorithm, which gets independent paths from weakly connected nodes, to select probe stations. Simulation experiments have shown that, compared with k -path algorithm, the method has fewer probe stations while keeping stronger fault localizing capability when used in multiple fault localization. So, the faults in networks can be localized sooner and cost-effectively by using this method to deploy probe stations and implement active probing.

Abstract:Based on muscle control items, a uniform model for facial action was constructed, which consisted of time series and the corresponding vector series. With the top-down motion planning, the facial action could be decomposed to motion unit by time, type of motion, singular point and control item. To solve the inconsistent problem of adjacent motion units, a joining algorithm was designed according to their relationship. Nested script of facial action was defined to implement the complex facial action. Experiments have shown that the methods can implement continuous and complicated facial action realistically and effectively.

Abstract:In this paper, we have proved the sharp inequality for multilinear commutator related to Littlewood-Paley operator. By using the sharp inequality, we have obtained the weighted Lp -norm inequality for the multilinear commutator.

Abstract:In this paper, we investigated the existence of 4-(q+1,7,λ) designs with block-transitive automorphic group PGL(2,q), and the computer algorithm to construct the block-transitive 4-(v,k,λ) designs from PGL(2,q). We also constructed some 4-(q+1,7,λ) designs, in which the parameters can be given and can admit block-transitive automorphic group PGL(2,q).

Abstract:This paper was concerned with simulation-based inference in generalized models of stochastic volatility with long memory. A more efficient Markov Chain Monte Carlo sampling method was exploited to the analysis of the model, compared with the single step Gibbs sampling method. Based on the truncated likelihood method, in which the long memory stochastic volatility model was expressed as a linear state space model, we utilized the forward filtering backward sampling method to sample all the unobserved volatilities simultaneously. A simulation method for Bayesian prediction analysis of the volatilities was also developed. The simulation study has given the results of estimated parameters and evaluated the performance of our method. Moreover, the prediction analysis of the volatility can be used to control the risk of financial series.

Abstract:A statistical inference from the existing ice thickness data was made. The time series model of ice thickness was established, and the statistical inference from ice thickness was made. Then, the parameter estimation of the inference model by MCMC was conducted on the basis of the Gibbs sampling. At last, error correction of the Markov Chain Monte Carlo(MCMC) model was carried out to solve the error increase problem when the sample data was not enough during the maximum likelihood estimation. A comparison between the Gibbs sampling results by WINBUGS software and the maximum likelihood estimation result was made. By analysis and comparison, it has been proved that the Bayesian method for error correction has a higher accuracy for the estimation of the ice thickness on the cable.