bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Outward Foreign Direct Investment from China Enterprises from the Financial Development Perspective
Authors: Jiang Ya Peng , Fu Yu Guo , Wang Fei
Published: October 2013

To explore constraints on outward foreign direct investment £ ̈OFDI£© from China enterprises, this thesis analyzes the relationship between OFDI and financial development. Theoretical analysis of extended AK model and Geweke causal decomposition test show that financial development significantly related to the OFDI from China enterprises and financial repression is a constrain on OFDI to some extent. To promote fair, reasonable, orderly and sustainable development of OFDI from China enterprises, we should pay attention to not only the temporary strategies, such as policy-based finance, development finance and administrative action, but also to the promotion of financial development itself.
Generalized Gradient Based Digital Image Correlation Method for Displacement with Subpixel Accuracy
Authors: Zhang Rui
Published: October 2013

Basic principle of generalized gradient based digital image (DIC) method for subpixel-accuracy displacement measurement is discussed. The proposed method can cope well with lighting illumination variation or grayscale intensity change on the object surface during measurement by adopting a linear intensity change model, which overcomes the limitations in existing linear least squares based spatial gradient method by adopting constant model. To evaluate the proposed methods, both computer simulation and actual experiment have been carried out. The results show that the proposed method can measure displacement accurately even when substantial intensity variations exist in the experimental images.
ETL Application in Telecom Industry Based on Teradata
Authors: Shi Jing Dan , Li Min , Zhang Qin He , Wei Xuan
Published: October 2013

In the telecommunications industry, because of the information from different data sources, there are many discrete, uncertainty and heterogeneous data types cannot be used directly for data warehouse, there is not common ETL model. In this paper, investigation for the ETL tools in the Teradata warehouse, design a general ETL model for telecoms industry. Take the telecom business analysis system for example, verify the ETL model, prove that ETL model improve data conversion efficiency and it is good generality.
The Study of Generative Modeling of Text
Authors: Jiang Jing Jing , Wang Xiao Yu , Mu Xiang Wei , Hu Jia Xing , Zhu You Qin
Published: October 2013

Text mining is the task of automatic discovery of new, previously unknown information from unstructured document collections. Vector space or bag of words representation is one of the mainstream descriptions of text, in which each document is a data point in high-dimensional space and order between words is omitted. Generative models are probabilistic representation of data that can be regarded as the generator of observed data. Being probabilistic modelling approaches, a set of methods and criterions are available for model estimation, inference, comparison and selection for generative models. In this paper, we review several existing probabilistic models that are commonly applied to discrete exchangeable collections in English text. We hope this will shed some light on the Chinese text modelling and mining tasks.
Situation & Prospect of Research on Talus Slope
Authors: Wang Xi Dong , Ruan Yong Fen , Li Qi , Wang Fei
Published: October 2013

Due to its origin reasons, deformation failure mechanism, and geometry boundary condition,the property of talus slope is very complex and may bring serious environmental problem. Whats more, the destruction of landslide and the handling of talus slope impact on the natural environment and engineering. In particular, in order to ensure its stability, some of natural environment is changed seriously by cutting slope, it is serious affected the ecological environmental deterioration. This paper highlights the problems universally existing in incompetent talus slope engineering; a review is made on the theoretical results and research progress achieved in internal qualities, destabilization pattern, deformation, stability, dynamic analysis. Then the existing problems and further research direction are proposed, so as to provide a reliable reference for further research or work.
Developed New Type of Pneumatic Spray Nozzle and Research of Spray Characteristic
Authors: Zhou Si Qing , Cheng He Ming , Li Jian Yun , Wei Liu Chuang , Zhang Xue , Yang Tie Xin
Published: October 2013

The Pneumatic atomizing nozzle is quenching test professional nozzle which is designed for new quenching process taking high-pressure nitrogen gas water as quenching medium. It meets the requirements of high pressure nitrogen quenching process and reaches the requirements that particle size can be adjusted, flow spray field coverage angle is large, flow and pressure are adjustable and the amplitude of accommodation is big. The nozzle special for high-pressure gas quenching test is less and it can only be chose from other functional nozzles, having great limitations. The development of nozzle special for high-pressure gas quenching will have a certain role in promoting the popularization of high-pressure gas quenching technology and the development of nozzle technology.
The Homotopy Analytic Solutions for a Class of Jamming Transition Problem in Traffic Flow
Authors: Han Xiang Lin , Ouyang Cheng
Published: October 2013

By choosing deferent initial approximation solutions and deferent linear operators, the nonlinear equation of the jamming transition problem (JTP), which is based on the Lorentz system, in traffic flow is discussed. The approximation solutions of the JTP are obtained using the homotopy analysis method (HAM). The method of choosing the linear operators and the initial approximation solutions, the corresponding residual errors and the influence of the boundary condition to the solution are studied respectively. By comparing the present results with the previous related studies, the conclusion is drawn that the HAM is superior to the differential transform method. The correctness of the theoretical analysis is confirmed by numerical simulation and the analysis of the residual errors.
Research of Closed-Loop Control for Underwater Heat-Engine Propulsion System
Authors: Li Wang , Wang Yu Cai , Luo Kai , Song Bo Yi , Huang Chuang
Published: October 2013

Closed-loop control for underwater heat-engine propulsion system is an essential solution to improve the control performance and optimize the autonomous underwater vehicles (AUV) trajectory. This paper minutely gives the project of the closed-loop control proposal we propose for the propulsion system, and puts forward a control arithmetic according to the mathematical model that has been build for the system. Even more remarkable is that a series of experiments are carried out on the semi-physical simulation test bench to verify the control arithmetic. The experimental results and the analysis indicate convincingly that the control arithmetic can compensate for the navigation depth and attitude of AUV, thus making the propulsion system get the ability of tracking the variable working condition. Therefore, the power system gives full play to its potential.
Aerodynamic Shape Deformation of Underwing Nacelle-Pylon Configuration Based on B-Spline Surface
Authors: Ma Xiao Yong , Ai Jun Qiang , Shan Ji Xiang , Li Yong Hong
Published: October 2013

A free deformation method based on the B-Spline (NURBS) and surface superposition technique was presented for complex aerodynamic shape deformation. The influences of control parameters including control points, order, knots and weights are analyzed with B-spline curves case. Using the developed method, the application of surface grids deformation on the wing and pylon of DLR-F6 plane shows that the control parameters only influence its local surface, and this method could describe complex surfaces effectively, which means that this method is feasible and applicable to model representation, surface grids deformation and aerodynamic shape optimization.
Improving the Robustness of Adjoint-Based Airfoil Drag Reduction Design
Authors: Fan Yan Hong
Published: October 2013

The effect of steps in the line search on the consistence of adjoint-based drag reduction of airfoil is investigated in this paper. Constant step adopted in drag reduction design usually gives different optimization results and choice of constant step often depends on designers experience and optimization problem. Bracket method is applied to automatically give the optimal step in performing drag reduction design of airfoils RAE2822 and S73613 and the consistent optimal results are obtained. The results illustrate that the linear search method can automatically find the optimal step, and overcome the restriction on choice of user-defined constant step which is used in the traditional adjoint-based optimization method. That is, it reduces the dependence of step in the drag reduction design, and improves the robustness of the adjoint-based airfoil drag reduction optimization design method.
Lattice Boltzmann Method for the Simulation of High Reynolds Number Flows
Authors: Liu Qiang , Xie Wei , Qiu Liao Yuan , Xie Xue Shen
Published: October 2013

The lattice Boltzmann method (LBM) is considered as an alternative scheme to the standard Navier-Stokes approach. To simulate the high Reynolds number turbulence, several approaches based on LBM have been proposed. Among them, 5 approaches including the direct numerical simulation, dynamic subgrid scale model, inertial range consistent subgrid model, very large eddy simulation and entropic lattice Boltzmann method are discussed in detail. Features including improvements and shortcomings of each approach are presented. Whats more, application prospects of these approaches in high Reynolds number turbulence simulations are pointed out.
Investigation on the Multi-Objective Optimization of Supercritical Airfoil Based on Nondominated Sorting Genetic Algorithm
Authors: Liu Da Wei , Peng Xin , Xu Xin , Chen De Hua
Published: October 2013

This paper aimed to investigate the multi-objective optimization method of supercritical airfoil. To achieve the optimal design of supercritical airfoil Rae2822, an improved NSGA-2 (Nondominated Sorting Genetic Algorithm) method was utilized, while the cross-operator and adaptive-variation operator were introduced to improve the convergence speed of the algorithm. During the optimization, the airfoil parametric modeling was achieved based on the Bezier-Bernstein method, and the objective function was obtained through solving the N-S equations. Considering the parallel computation characteristics of the algorithm, the computation was conducted in large-scale Linux computer system to reduce the solving time. Optimization results showed that the undominate solution with high quality obtained through the NSGA-2 method distributed evenly, which provided the designer a wider choosing space. It was also showed that the multi-objective optimization method presented in this paper was feasible and reliable.
OpenCL-Based GPU Acceleration of ISPH Simulation for Incompressible Flows
Authors: Qiu Liu Chao
Published: October 2013

Thanks to the recent development of tools such as CUDA and OpenCL it has become possible to fully utilize Graphical Processing Units (GPUs) for scientific computing. OpenCL promises huge savings in parallel code development and optimization efforts due to it is not restricted to a specific architecture. We have developed an OpenCL-based acceleration framework on GPU for numerical simulations of incompressible flows using incompressible Smoothed Particle Hydrodynamics (ISPH). In order to assess the performance of the GPU implementation presented in the present work, a comparison was made against the implementation of the same ISPH in CPU using OpenCL.
Numerical Simulation and Experimental Study on Hydraulic Performance of Centrifugal Pump's Impeller Based on FINE
Authors: Shang Yong , Liu Xiao Bing , Yu Xue Jun
Published: October 2013

By using the FINE software developed by NUMECA Company, the hydraulic performance of the impeller of a centrifugal pump with spatial guide vanes was numerically simulated. The S-A turbulent model was used to numerically calculate the three-dimensional flow field in the centrifugal pump under three different conditions. The flow analysis shows that the pressure gradient on the vane surface gradually reduces with the increasing of the flow rate; the position of axial vortex between vanes has nothing to do with the flow rate; the tangential flow gradient in the flow passage decreases with the increasing of the flow rate. Compared with the test results, it is obvious that this numerical simulation can accurately predicate the complicated three-dimensional flow and the hydraulic performance of the pump.
Numerical Simulation of Viscous Flow in a 3D Lid-Driven Cavity Using Lattice Boltzmann Method
Authors: Dong Di Bo , Shi Sheng Jun , Hou Zhen Xiu , Chen Wei Shan
Published: October 2013

A lattice Boltzmann method (LBM) with single-relaxation time and on-site boundary condition is used for the simulation of viscous flow in a three-dimensional (3D) lid-driven cavity. Firstly, this algorithm is validated by compared with the benchmark experiments for a standard cavity, and then the results of a cubic cavity with different inflow angles are presented. Steady results presented are for the inflow angle of and, and the Reynolds number is selected as 500. It is found that for viscous flow under moderate Reynolds number, there exists a primary vortex near the center and a secondly vortex at the lower right corner on each slice when, namely in a standard 3D lid-driven cavity, which cant be found when. So it can be thought that the flow pattern in a 3D lid-driven cavity depends not only on the Reynolds number but also the inflow angle.
Numerical Simulation of Two-Dimensional Flows Using the Feedback Force Immersed Boundary Method
Authors: Su Shi Qi , Wang Wen Quan
Published: October 2013

In this paper, numerical simulation of flow around a cylinder using the feedback force immersed boundary method is carried out. The feasibility of algorithm is verified by the numerical simulation of flow past two cylinders in tandem arrangement. The Cartesian adaptive mesh refinement is used in the whole flow field, and the dynamic distribution characteristics of flow field around a single cylinder and double cylinders are obtained when Re=100. Compared with the results in other literatures, the simulation shows a good agreement.
Study on Comb Labyrinth Seals of Francis Turbine at Different Reynolds Number
Authors: Wang Wen Quan , Su Shi Qi , Yan Yan
Published: October 2013

To research the leakage characteristics and sealing mechanism of the comb labyrinth seals, three-dimensional solutions of NavierStokes governing equations are utilized to investigate the leakage characteristics of the comb Labyrinth for water sealing in leakage flow passage of Francis turbine. The finite volume method is used to discretize the Navier-Stokes equations. The quick scheme and the second central scheme are applied to solve convection and diffusion terms respectively. Distributions of velocity and streamline as well as some flow structure in leakage flow passage are gained at different Reynolds numbers. The results show that vortex generated in the comb consumes kinetic energy and causes the pressure decrease greatly, which play a major role in decreasing the leakage flux.
Numerical Investigation of Three-Dimensional Flow over a Swept Backward-Facing Step Using a Multi-Scale Turbulence Model
Authors: Yang Qing , Li Zhi Qiang , Shao Xing Chen , Dong He , Tang Yang Yang
Published: October 2013

Using a multiscale model based on the variable interval time average method and a set of averaged equations for incompressible turbulent flows, we simulate the three-dimensional separated and reattaching flow over a swept backward-facing step. The results show that the reattachment length and vortex structure vary with the swept angles from 15° to 60° through a detailed study about velocity profile and pressure distribution. Generally the reattachment length and span wise vorticity decrease dramatically after =30°. The result fully accord with experimental data. Results show that this model is suitable for separated flows, and accurately predict the flow field, so this model should be useful in engineering application.
The Static Analysis of Pilot Type Zero Steady-State Error of Water Hydraulic Pressure Reducing Valve
Authors: Yang Huan , Luo Jing , Hui Sen , Qiu Shi Yin , Xue Rong Ping , Zhang Yi Bo
Published: October 2013

The static-state error is existed in the pressure valve, coupled with the characteristics of high vaporization pressure, low viscosity, and small compressibility, so that the fluid dynamics and friction force of hydraulic pressure valve are increased. The pressure valve will easily come up with produce cavitation erosion and wire drawing. Those appearances would seriously affect the performance of the pressure valve and its life cycle. A new type of static water pressure reducing valve is designed in this paper. It has a special structure which can complete the internal dynamic pressure feedback of the valve. The static mathematical model of value is established. And the static characteristic is analysed by using MATLAB simulation, which provides the static pressure characteristic curve, static pressure flow curve. It comes up with a result that this valve has good static pressure, and high precision pressure regulator.
Effects of Weakly Compressibility on Propagating Properties of Water Hammer in a Long Pipe
Authors: Zhou Kun Xiong , Zhang Li Xiang
Published: October 2013

This paper is concerned with propagating features of pressure waves induced by water hammer in a long liquid-conveyed pipe subjected to hyper high water head. Effects of dynamically weak compressibility of the water in pipe and pipe wall elasticity on the propagating physics were investigated by comparing in-site measurements and theoretical analyses. The pressure wave form and propagating speed were significantly effected due to weak compressibility of the water and the interactions of the waves. The wave performs a strong unsteadiness while it propagates along the pipe. This study tries to explain an event with consideration of both the dynamically weak compressibility of the water in pipe and the closing features of the valves controlled actively.
Numerical Simulation of Cavitation Flow in a Centrifugal Pump
Authors: Zhao Wei Guo , He Xiao Xia , Wang Xiu Yong , Li Yi Bin
Published: October 2013

Based on two phase homogeneous mixture model, numerical simulation of the cavitating flow was performed on a centrifugal pump. Cavity shapes and performance of the pump in variable cavitation numbers were obtained. Numerical results show that the numerical method can be used to predict the cavitation performance of centrifugal pump; the incipient cavitation number is predicted, and the cavity shape is similar with the experiment; cavitation usually appears in the suction surface of the blade and locates in the inlet side, and becomes longer to the outlet direction with lower cavitation number; when the cavitation number is relatively higher, cavitating region locates in the inlet area of the blade and is relatively stable, while develops and separates when cavitation number becomes lower; when the cavitation number equals to the incipient cavitation number, performance of the centrifugal pump has no change almost, only when cavitation number reduces to some extent, the head decreases abruptly and also the efficiency, which means the pump operates in a bad condition and this condition should be avoided in the practical operation.
Simulation Method for 3-D Wind Field over Complex Terrain with Asymmetrical Mountains
Authors: Hu Huan Ran , Hong Guan Xin
Published: October 2013

It is important for the research of flight characteristics to master the distribution of wind field and the character of turbulence intensity in a complex-terrain mountain. Based on the potential flow theories in fluid dynamics, a numerical simulation method of complex terrain including asymmetrical and symmetrical mountains has been developed in this paper. In particular, asymmetrical mountains are simulated by the combination of two transformed quarter-semiellipsoids. Furthermore, mountain-induced airflow is calculated based on potential flow theory, which could reflect the characteristic of wind field. As an example, the wind field near Dingling airport in Beijing has been simulated and analyzed by this method. The results demonstrate that this method is suitable and accurate for engineering practice, and also applicable for flight dynamics characteristics analysis of aircrafts.
Research on High Vacuum Phenomenon Produced by Aquatic Vortex
Authors: Shao Xing Chen , Gao Ge
Published: October 2013

We designed a kind of swirler to produce strong vortex which was inspired by tornado . Focusing on the velocity and pressure distribution of inlet flow within the swirler, we also conducted a series of numerical simulations on the swirler when we set geometric inlet conditions at the bottom ,middle and top of the swirler. The simulation results showed :1 When the geometric inlet condition was set in the middle of the swirler, it would produce the strongest magnitude of vorticity and the highest vacuum degree in the center of vortex compared with other two places.2When we set the geometric inlet condition at the middle of the swirler, it would create reversed swirl flow. We discovered that such kind of reversed swirl flow would enhance the magnitude of main swirl flow vorticity.
Suppression Effect of Jet Flow on Aerodynamic Noise of 3D Cavity
Authors: Yu Pei Xun , Bai Jun Qiang , Guo Bo Zhi , Han Xiao , Han Shan Shan
Published: October 2013

The structure of cavity flow field with high mach number is very complex, in which pressure and velocity pulsate seriously, leading a seriously noise about almost 170dB. The noise poses a great threaten to the safety of the missile in the cavity and the structure of the cavity. The active control method (jet flow) by applying the CFD technology based on Scale-Adaptive Simulation (SAS) model developed from two-equation SST turbulent model is used to simulate the changing of the dynamic noise in the standard cavity M219(the ratio of the length to the depth is 5), and studied the flow character, flow field structure and noise mechanism. First, the accuracy of the noise prediction method is validated. Base on above-mentioned method, the suppression effect on the noise in the cavity of jet flow is analyzed and the conclusion is that jet flow has a great influence on the aerodynamic noise suppression in the cavity.
A Bidirectional B-Spline QR Method for the Analysis of Reinforced Concrete Shear-Wall with Opening
Authors: Li Shuang Bei , Liang Qing Guo , Mo Du Yi
Published: October 2013

In this paper, based on the bidirectional B-spline QR method (BB-sQRM), the mechanical properties of the shear-wall with opening were studied. The cubic B-spline function (CB-sF) was used to construct the basis function of the BB-sQRM for its good properties. The new computational scheme of the BB-sQRM for structural analysis was established with quadrilateral element. Numerical example was given to illustrate the validity of the proposed algorithm for the shear-wall with opening. The reliability of the proposed algorithm was verified by comparing with the results of ANSYS. The effects of the opening size on lateral displacement and stress of the shear-wall with opening were discussed. The numerical results show that, square hole and rectangular vertical hole are more conducive to bearing capacity of the shear-wall with opening.
LASSO-Type Variable Selection Methods for High-Dimensional Data
Authors: Fu Guang Hui , Wang Pan
Published: October 2013

LASSO is a very useful variable selection method for high-dimensional data , But it does not possess oracle property [Fan and Li, 200 and group effect [Zou and Hastie, 200. In this paper, we firstly review four improved LASSO-type methods which satisfy oracle property and (or) group effect, and then give another two new ones called WFEN and WFAEN. The performance on both the simulation and real data sets shows that WFEN and WFAEN are competitive with other LASSO-type methods.
Natural Vibration Analysis of Piezoelectric Smart FGM Plate by Spline Finite Point Method
Authors: Li Shuang Bei , Huang Jun , Qin Rong
Published: October 2013

The spline finite point method (SFPM) that is based on the classical laminated plate theory is introduced to investigate the natural vibration of smart FGM plate, which is integrated with piezoelectric layers. The spline basic function that meets different boundary conditions is constructed by the generalized parameter method, and a new dynamic computational scheme for smart FGM plate is established to analysis the natural frequency that considering influence of the axial force, which is generated by the electric field. To demonstrate the less computational cost and higher accuracy of the SFPM, several numerical examples are calculated. The effects of the electric field and the influence of the thickness ratio of piezoelectric layer and substrate on the fundamental frequency are also discussed.
Efficient Rainbow Options Pricing Methods Based on Two-Dimensional Fourier Series Expansions
Authors: Ding Deng , Meng Qing Jiang , Zheng Jia Yu
Published: October 2013

An efficient option pricing method based on two dimensional Fourier series expansions was proposed by Ruijter and Oosterlee in 2012, recently, this method was extended to modified two dimensional Fourier series expansions by Meng and Ding. In this paper, these methods are applied to deduce efficient pricing formulae for two bivariate assets rainbow options, so called as put-on-mini-
mum and call-on-maximum. A series of numerical experiments for such options pricing is presen-
ted to compare these methods, and some conclusions are then given based on those numerical results.
Effects of Noise on the Approximate Entropy of Fractional Brownian Motion Sequence
Authors: Hu Xu Yi , Wan Li , Xie Dan Ying
Published: October 2013

Approximate entropy is a widely used technique to measure system complexity or regularity. In this paper, the effects of noise on the approximate entropy of fractional Brownian motion were investigated by some factors including the value of Hurst exponent, different noise type and coefficients. The results show that the values of approximate entropy of fractional Brownian motion decrease with the increase of Hurst exponent. The values increase in different degree after adding white noise in the sequence of fractional Brownian motion, and tend to be stable with the data lengthened. Meanwhile, the values of approximate entropy of mixed sequence change obviously by adding Poisson noise, while multiplying the coefficients of Poisson noise, the effects on the approximate entropy become greater.
Stochastic Nonlinear Aeroelastic Analysis of a Swept Wing Based on Nastran
Authors: Li Yi , Yang Jun , Chang Nan
Published: October 2013

For both military and civil aircrafts are in service, there is always a variation of free play among the joint components of control due to wear. In fact, the variation of free play is an uncertain parameter. In this paper analytical procedure was developed basing on Nastran, which can quantify uncertainties in the complicated swept wing with control surface and gives the quantificational risk information about nonlinear aeroelstic stability in the practice.
Experiment Study of Chaos Motion of Cable-Stayed
Authors: Li Jin Hai
Published: October 2013

The cable-stayed is one of the principal force members of cable-stayed bridges. It would be prone to exhibit vibration of large amplitude on the action of wind, earthquake and traffic load,so it reduces the life of stayed cable and even cause destruction. In order to reduce the cable damage, it is very necessary to study the mechanism of vibration of cable-stayed. Experiments are conducted to explore the nonlinear vibration of cable under the periodic external force. A cable model with 14.3 meters long is set up and an acceleration sensor is installed on the midpoint of cable.
Time-history acceleration data are obtained by using of acceleration sensor under three cycle load. From the data a Poincare Map is provided and chaos motion is confirmed by using of Smale Horseshoe Map theory.
Nonlinear Simulation of Aircraft Longitudinal Flight Dynamics
Authors: Mohammed Tariq O. , Wu Xiang Jin , Li Dao Chun
Published: October 2013

The purpose of this paper is to simulate flight path of Boeing-747 for longitudinal motion at selected flight conditions using 6 DoF (Degrees of freedom) nonlinear equations with MATLAB and SIMULINK. The equations are solved to compute the flight path within 100 seconds of Boeing 747 at three flight conditions, for cruise flight with different Mach numbers at same altitudes, and then Mach number at high altitude with MATLAB programming (ode45). Simulation results for different conditions are presented and analyzed.
Optimization Algorithm of Crack Initial Angle Using the Extended Finite Element Method
Authors: Su Yi , Wang Sheng Nan , Du Yong En
Published: October 2013

The extended finite element method (XFEM) allows the entire crack to be represented independently from the mesh, which means re-mesh is unnecessary in model crack growth, reduces the computational time drastically. However, fatigue crack growth simulation has been computationally challenged by lots of analog computations in crack growth. Therefore, a new reanalysis algorithm based on incremental Cholesky factorization is derived. In this paper, we consider a variant of XFEM in which an exponent discontinuous function is used to simulate the crack through unit. Then the corresponding formula of XFEM with inclusion and crack problem with a new reanalysis algorithm is derived. In the end, we use the new reanalysis algorithm and an optimization algorithm to predict the angle of crack initiation from a hole in a plate with inclusion. It shows that the algorithm is effective.
Subharmonic Bifurcations and Transition to Chaos in a Pipe Conveying Fluid under Harmonic Excitation
Authors: Geng Yi Xiang , Liu Han Ze
Published: October 2013

The subharmonic and chaotic behavior of a two end-fixed fluid conveying pipe whose base is subjected to a harmonic excitation are investigated. Melnikov method is applied for the system, and Melnikov criterions for subharmonic and homoclinic bifurcations are obtained analytically. The numerical simulations (including bifurcation diagrams, maximal Lyapunov exponents, phase portraits and Poincare map) confirm the analytical predictions and exhibit the complicated dynamical behaviors.
Model Analysis for Comprehensive Transportation Structure Evolution Based on Catastrophe Theory
Authors: Wu Li Ping , Pang Chun Ping , Qian Bin
Published: October 2013

The cusp catastrophic model based on catastrophe theory is presented to analyze the development pattern evolution of comprehensive transportation system (CTS for short). By establishing cusp catastastrophe model of development pattern we obtain that the construction of comprehensive transportation system should include two parts, the first part is the stock optimization and the second part is the increment construction. With the increment construction as the turning point, promoting the fast optimization of the stock should be the basic principles of the construction and development of CTS.
Aircraft Evacuation Simulation: A Developing Method to Improve Aviation Safety
Authors: Chen Da Wei , Qian Zhon Gyan , Xue Cai Jun
Published: October 2013

To achieve airworthiness requirements, 90 second certification test is performed to show compliance. Recent development in the application of computer simulation makes it possible to improve aviation safety through aircraft evacuation simulation. The approach can replace the full scale certification demonstration and has attracted extensive interest. Various evacuation models have been developed to simulate evacuation process. This review investigates the modeling theoretical foundation and summaries individual applications in different scenarios. Moreover, a meaningful research field is proposed for further study.
The Finite Element Analysis of the Large Horizontal Axis Wind Turbine Generator Tower
Authors: Chen Wei , Wang Shi Yue , Cao Liang , Wang Hui Ming , Yao Ji
Published: October 2013

Building finite element model of wind turbine tower, analyzing Static and modal of tower with using finite element analysis software ANSYS .Getting stress distribution, maximum displacement, natural frequencies and modes of vibration by finite element modal analysis of wind turbine tower and analyzing natural frequencies of wind turbine tower to determine whether to cause the tower and the wind wheel drive resonance.
A New Method for Improving the Stress Status of the Dam
Authors: Cui Jian Hua , Qi Yong Feng , Su Jie
Published: October 2013

Under the action of annual change and sudden drop of air temperature, thermal induced cracking will occur in concrete dam during the operation period. For exploring the temperature control measures for crack prevention, taking a concrete gravity dam section as the research object, sensitivity analyses to the factors which affecting the water-cooling effect are conducted with 3D FEM, some significant suggestions for the water cooling are presented. The results show that, the stresses of the dam surface will decrease to a certain extent after water cooling in the operation period using the cooling water pipe which embedded during construction period, and the cracking risk of the dam will reduce. The study provides a new train of thought for the temperature control and crack prevention of the mass concrete during the operation period.
Karst Rocky Desertification Remote Sensing Monitoring by Integrating Land Use Diagnoses in Southeast of Yunnan Province
Authors: Gan Shu , Yuan Xi Ping , Sun Gang , Zhang Xiao Lun , Li Ying
Published: October 2013

Karst rocky desertification is one of the serious environment problems in southwest of China. In this study, a typical county with karst rocky desertification which located in Southeast of Yunnan province is selected as a work area at first. Based on the datum collection about land use status and field verification surveying in study area, the technique of remote sensing image processing and GIS spatial analysis was integrated used to monitor the karst rocky desertification status and got its information in different degree. Analysis for karst rocky desertification spatial distributing, the main result is that there is more amount proportion of karst rocky desertification land cover in case study area and these large numbers patches of karst rocky desertification mosaic beset in the different land use types, such as forest, plantation and artificial town or other infrastructure building. So it is stringent need to deepen research the karst rocky desertification development and its spatial expand. Another result include that remote sensing monitoring for the karst rocky desertification is one of the important advance technique method, but it also need to fuse more another assistant information according to the actual condition in case study area, for example, the land use status in quo is a good means to assistant remote sensing monitoring karst rocky desertification by spatial restrict effect.
Response of Sluice-Dam Structure on a Strong Earthquake Excitation
Authors: Ge Lei , Zhang Li Xiang , Li Ze
Published: October 2013

For a high-rise complex structure built at an earthquake zone, response characteristics to an earthquake action are always needed to be as an important index to evaluate its dynamical performances. This article carried out a three-dimensional dynamical response analyses of a large-scale complex sluice-dam structure by using the software of ANSYS under a strong earthquake excitation by nonlinear finite element method. Through the analyses of the time history response of the high-rise complex structure to the specified earthquake records, the seismic performances of the structure system under consideration of the rock foundation-sluice structure-reservoir water interaction were well evaluated.
Effect of Bolt Slippage on the Static Response of Lattice Structure
Authors: Wang Peng , Chen Hai Bo , Huang Wei Dong , Lin Yue , Zhang Hui Wu
Published: October 2013

Bolted connection technology has been widely used in steel structure engineering. Conventional structural analysis softwares solve related problems with the assumption of regarding the bolted connection as a rigid joint connection. Thus the calculated internal forces of the structure members are bigger than those of real measurements, and the calculated displacement are smaller than the experimental ones under the same load. One of the main reasons is the bolt slippage. In the lattice structure, there are a large number of bolted connections with thin connection members and small-diameter bolts, however, their clamping forces are relatively small. These characteristics have significant effects on the static response of the lattice structure. In this paper, in comparison with the test results, the deformation-load curves of the bolt connections are introduced into the finite element simulation, revealing the effect of bolt slippage on the static response of lattice structure. The simulation and test results show that the bolt slippage causes the redistribution of the member internal forces of the lattice structure and increases the displacement of the lattice structure,thus the simulation results with bolt slippage are more close to the real values. The proposed algorithm and simulation results would provid good reference for further engineering applications.
Multi-Core Desktop Parallelized Water Quality Model Applied to Xiangxi River, China
Authors: Li Jian , Jin Zhong Wu , Yao Shi Ming
Published: October 2013

The Yangtze River and its tributaries located in Three Gorges Project (TGP) reservoir was influenced by the operation of TGP reservoir, and the water quality problems were becoming serious these years. Mass transportation in the tributaries was interacted with the hydrodynamic field. Then, a parallelized three dimensional unstructured mesh water quality model was applied to Xiangxi River - one of tributaries of Yangtze River - to simulate the changing processes of flowing and nutrients including TP and TN. The results show that the parallelization model can enhance the simulation efficiency, especially when the computational scale is large. The parallelized model was executed in Windows operation system could make sufficient use of the resources of low-end multi-core personal computer. The parallelized model could provide a new tool for river water quality research and the information for management of TGP reservoir.
Safety Analysis of Static & Dynamic Method in Foundation Pit Considering Unsaturated Seepage
Authors: Zhou Yi Hong , Li Xiu Wen , Peng Yun Feng , Zhang Ting
Published: October 2013

In order to study whether foundation pit is stable or not after excavation, the article adopted the Duncan E-B model to make static analysis for the excavation scheme which considering the soil consolidation settlement and to make dynamic analysis under the action of earthquake wave of EL Centro. To make a slope stability of foundation pit analysis by calculating static and dynamic boundary conditions which further coupled with the Newmark method. The main study is the foundation settlement and earth-rock dams, slope stability of foundation pit conditions that considering unsaturated zone seepage conditions of earth-rock dams after the excavation. The results indicated that: in the static & dynamic analysis, the distribution about settlement is reasonable, earth-rock dam and foundation pit slope is in the steady state, the excavation scheme is reasonable and feasible.
A Meso-Structure Analytical Model to Describe the Cracking Process due to Reinforcement Corrosion in Concrete Structure
Authors: Zhou Yi Tang , Li Luo Ke , Cao Peng , Wang Yi Na
Published: October 2013

The degradation of concrete structures due to steel reinforcement corrosion is a serious problem for durability and serviceability. Cracking behavior due to reinforcement corrosion is evaluated experimentally and analytically in this paper. In the experiments, in which corrosion was induced electronically, the structure proportion of corrosion product was analyzed. In the analysis, a micromechanical cracking mechanical analytic model, which considered the coupling effects of corrosion product and concrete protective layer was established. The initial cracks and crack growth process of smeared cracks in cover concrete were simulated and explored for the deterioration process of concrete structures due to corrosion expansion. It is indicated that the numerically predicted crack mode agrees well with the experimental results.
A Review of the Extended Finite Element for Fracture Analysis of Structures
Authors: Wu Liang , Zhang Li Xing , Guo Ya Kun
Published: October 2013

The extended finite element method (X-FEM) is reviewed and some new developments for fracture analysis of structures is presented. The X-FEM is an extension to the classical finite element method (FEM), using the concepts of partition of unity and meshless approaches. It is specifically designed to improve the performance of the conventional finite element method, while keeping the computational costs at an acceptable level, and avoiding the cumbersome remeshing of FEM in crack propagation problems. The simplicity, flexibility in handling several cracks and crack propagation patterns on a fixed mesh, and the level of accuracy with minimum additional degrees of freedom have transformed X-FEM into the most efficient numerical procedure in the arena of computational fracture mechanics.
Network Based Passenger Flow Modeling for Station Crowdedness Evaluation
Authors: Ma Jian , Lo Siu Ming , Chen Juan , Liu Shao Bo
Published: October 2013

The pedestrian comfort and safety level in mass transit stations is now attracting more and more attention in the past few years for the reason that the congested pattern in stations resulted from complex pedestrian activities including using the ticket add value machine, buying a ticket, shopping, waiting for services etc. Thus multi-directional pedestrian flows interact with each other and finally formed a relatively complex pedestrian distribution. To evaluate the crowdedness of the station for the convenient of crowd control, the crowded pedestrians are simulated with a heterogeneous network model in combined with a collision avoidance model. Based on the network model, a spatial configuration related station network is constructed, on which pedestrian flow can be formulized. At last, a station flow scenario is simulated and discussed with the formulized model to evaluate the complex activities induced crowdedness in metro station.
Prognostic Factors in Adult Soft Tissue Sarcoma Treated with Surgery Combined with Radiotherapy: A Retrospective Single-Center Study on 164 Patients
Authors: Cai Ling , Mirimanoff René-Olivier , Mouhsine Elyazid , Guillou Louis , Leyvraz Pierre-Francois , Leyvraz Serge , Gay Beatrice , Matzinger Oscar , Ozsahin Mahmut , Zouhair Abderrahim
Published: October 2013

The aim of the present study is to assess the disease profile, outcome and prognostic factors in patients treated with surgery combined with radiotherapy (RT), with or without chemotherapy (CXT), for soft-tissue sarcoma (STS) in a multidisciplinary setting. One hundred and sixty-four patients with STS treated between 1980 and 2010 at the Centre Hospitalier Universitaire Vaudois were enrolled in this retrospective study. Seventy-six percent of patients underwent postoperative RT with (24%), or without (52%) CXT, 15% preoperative RT with (5%), or without (10%) CXT, surgery alone (7%), or RT alone (2%) with or without CXT. The median follow-up was 60 months (range 6-292). Local failure was observed in 18%, and distant failure in 21% of the patients. Overall survival (OS), diseasefree survival (DFS), local control (LC) and distant metastases-free survival (DMFS) were 88%, 68%, 83%, and 79% at 5 years, and 80%, 56%, 76%, and 69% at 10 years, respectively. In univariate analyses, favorable prognostic factors for OS, DFS, and DMFS were tumor size 6 cm or less, World Health Organization (WHO)/Zubrod score 0, and stage 2 or less. Age and superficial tumors were favorable only for OS and DMFS respectively. STS involving the extremities had a better outcome regarding DFS and LC. Histological grade 2 or less was favorable for DFS, DMFS, and LC. Radical surgery was associated with better LC and DMFS. RT dose more than 60 Gy was favorable for OS, DFS, and LC. In multivariate analyses, independent factors were age for OS; tumor size for OS, DFS and DMFS; WHO/Zubrod score for OS, DFS and LC; hemoglobin level for DFS; site for DFS and LC; tumor depth for DMFS; histological grade for DFS and LC; surgical procedure for LC and DMFS; and RT dose for OS.

This study confirms that in a multidisciplinary setting, STS have a fairly good prognosis. A number of prognostic and predictive factors, including the role of surgery combined with RT, were identified. Regarding RT, a dose of more than 60 Gy was associated with a better outcome, at the price of a higher toxicity. We could not demonstrate a superiority of preoperative RT over postoperative RT.
Modelling and assimilation of lidar signals over Greater Paris during the MEGAPOLI summer campaign
Authors: Wang Y. , Sartelet K. N. , Bocquet M. , Chazette P.
Published: October 2013

Abstract. In this study, we investigate the ability of the chemistry transport model (CTM) Polair3D of the air quality modelling platform Polyphemus of simulating lidar backscattered profiles from model aerosol concentration outputs. To do so, simulated lidar signals are compared to hourly lidar observations performed during the MEGAPOLI (Megacities: Emissions, urban, regional and Global Atmospheric POLlution and climate effects, and Integrated tools for assessment and mitigation) summer experiment in July 2009, where a ground-based mobile lidar was deployed around Paris on-board a van. The comparison is performed for six different measurement days, 1, 4, 16, 21, 26 and 29 July 2009, corresponding to different levels of pollution and different atmospheric conditions. Polyphemus correctly reproduces the vertical distribution of aerosol optical properties and their temporal variability. In the second part of this study, two new algorithms for assimilating lidar observations are presented. The aerosol simulations without and with lidar data assimilation are evaluated using the Airparif (a regional operational network in charge of air quality survey around the Paris area) database to demonstrate the feasibility and the usefulness of assimilating lidar profiles for aerosol forecasts.