Showing papers in "Journal of Qingdao University in 2014"

Research on Properties of Nano-OMMT/SBS/Asphalt Composites

Abstract: The organic-montmorillonite/SBS compound modified asphalt was prepared using melt intercalation blending.The microstructure of the composite was characterized by means of XRD and optical microscopy;the effect of different mass fractions of OMMT on the physical properties of SBS modified asphalt was analysed;The rheological property and high-temperature stability of the composite was judged with Dynamic shear rheometer(DSR)and differential scanning calorimetry(DSC),respectively,and the hightemperature storage stability of the compound modified asphalt was measured with segregation experiment.Results show that montmorillonite disperses into SBS modified asphalt can improve its basic physical properties,rut resistance,aging resistant performance and its high-temperature stability.The overall properties of the compound asphalt were excellent when the mass fraction of OMMT was 3%.

Dissipativity Analysis and Control of Linear Singular Delta Operator Systems

Abstract: Aiming at the issue of singular discrete systems about dissipativity analysis and control,this paper applies a delta operator method to study and analyze the dissipativity of singular delta operator system.we obtain a necessary and sufficient condition that makes a linear singular delta operator system be admissible and strictly dissipative.As to these singular delta operator systems without admissibility and dissipativity,a sufficient condition is derived for the existence of a state feedback strict dissipative controller,and the explicit expression of the corresponding controller is also presented.By using MATLAB-LMI tools,some numerical examples are provided to demonstrate the feasibility and effectiveness of the theoretical results.It turns out that the close-loop system is admissible and strictly dissipative.These results suggest that the delta operator method makes a good application in the research of singular discrete systems about dissipativity.It provides a new way to research other properties of singular discrete system.

Traffic Flow Prediction Based on K-Means Clustering Algorithm and RBF Neural Network

Abstract: In view of the current traffic congestion and other road traffic problems,this paper optimizes the RBF neural network by using the K-means clustering algorithm.It uses K-means clustering algorithm to unify all of the input sample clustering,it obtains the RBF center value Ciof all hidden layer nodes and adjusts the weights of RBF network with the least squares method.At the same time within a certain amount of time and road for traffic data collection,through the establishment of RBF neural network model,it simulates the data and images collected by MATLAB.Simulation results show that without the K-means clustering,the prediction of the output curve can roughly fit the actual output,but at the moment of volatile data,the prediction curve is of slow convergence speed and the efficiency is low.With the K-means clustering algorithm of RBF neural network,when the actual outputs are volatile,the forecast of the curve of the outputs has higher convergence speed and accuracy.Therefore,this paper puts forward the RBF network based on K-means clustering algorithm.Compared with the normal neural network it has a higher prediction precision and better convergence.The study is applicable for traffic flow prediction in urban area.

Adaptive Fuzzy Control for Chaotic Permanent Magnet Synchronous Motor Based on State Observer

Abstract: Considering the chaotic behavior may undermine the stability of the permanent magnet synchronous motor(PMSM)drive system,this paper studies position tracking control of the chaotic PMSM with parameter uncertainties based on the principle of fuzzy adaptive control and backstepping techniqueWe design a new type of reduced-order observer to estimate the angular velocity of the PMSM systemFuzzy logic systems are utilized to approximate the unknown and nonlinear functions of the chaotic PMSM drive systemIn addition,backstepping technique is applied to design adaptive fuzzy controllersThe simulation results show that the proposed control method can avoid the chaotic behavior in PMSM and ensure that the system can track the desired signal quicklyThe control strategy can overcome the effect of PMSM parameter uncertainties and achieve a good control effect of position tracking control on PMSMThis study has lots of practical application value

Research on Lightweight Design and Optimization of a Light Duty Truck Frame Based on ANSYS Workbench

Abstract: For the problem of the lightweight design of automobile frame,the static analysis of a light duty truck was done by ANSYS Workbench in this paper.The finite element model of the frame was established.The boundary conditions of the frame suspension was processed.From the results of the static analysis,Lightweight improvement was done on the frame by adding hole that can reduce weight on the beam and thinning the wall of the stringer.Meanwhile,in the four different working conditions,strength and stiffness analysis were done on the improved frame,and the analysis results showed that the strength and stiffness of the frame in the 4different conditions meet the design requirements.Compared with the quality of the unimproved frame,the mass of the improved frame was reduced by 11.42 under the premise of the strength and rigidity requirements.The goal of the light truck frame lightweight is achieved.Therefore,the dynamic characteristics of the improved frame meet the requirements.

Analysis and Forecasts of Gold Price Based on the ARFIMA-GARCH Model

Abstract: The gold return series has a long-term memory and its residuals generate significant volatility clusters have been founded.The ARFIMA-GARCH model of gold price is presented by time series theory based on the closing price of gold in stock named AU99.95 in Shanghai Gold Exchange during 2007-01-04—2014-02-28,totally 1736 trading days.This model can fit the series precisely and can be showed by the empirical results,and the prediction error is small with software EVIEWS6.0and MATLAB.The model can be taken advantage to describe the production process of gold price dynamically.And it's beneficial to gold producers and investors to know more about the characteristics of the sequence of the gold price.

Stability Analysis for Singular Systems with Time Delays Based on Wirtinger-Based Integral Inequality

Abstract: In this paper,delay-dependent stability analysis for linear singular systems with time delay is studied.By constructing an appropriate type of augmented Lyapunov-Krasovskii functional containing a triple integral term and using the Wirtinger-based inequality,a new delay-dependent stability criterion is established in terms of linear matrix inequalities,which could be solved by using LMI tools of Matlab.The present method could produce better results than those using delay-decomposition methods.A numerical example is given to illustrate the improvement of the upper bounds of time delay and the effectiveness of the present results.It can be expected that the present method is useful for dealing with singular systems with time-varying delays.

Comparative Study on Credit Risk for China Listed Companies Based on Logit Model and KMV Model

Abstract: The credit risk for the chosen twenty-nine listed companies in China was analyzed with logit regression model and KMV model,respectivelyResults show that the two models can reflect the status of credit risk of listed companies basicallyAlthough the prediction of KMV model on non-default group is better than that of the logit model,logit model is much better than KMV model on the the prediction of default groupsOverall,the prediction efficiency of logit model is higher than that of KMV model

An Improvement for Clustering Routing Protocol in Ad Hoc Network Based on CGSR

Abstract: Based on the problems of the heavy burden and excessive energy consumption of the cluster heads in CGSR protocol,an improved clustering routing protocol called CSGSR is proposed,an improved LCC algorithm is used to select more than one node to complete the task of cluster head through cooperation,and effectively reduced the burden of one cluster head,balanced the energy consumption of the nodes,and increased the stability of the cluster.NS-2simulation results demonstrate that the improved protocol effectively extend the lifetime of the network.

Research on the Volatility of China Stock Returns Based on GJR Model

Abstract: Choosing the closing price of Shanghai Composite Index of a period,this paper constructs ARMA-GJR-M model with student-t distribution to research the volatility of China's stock market returns by using the method of mixture-of-models from the perspective of analysis of time series.Result shows that features of China's stock market returns,that is,the non-normality distribution and heavy-tails,heteroskedasticity,strong volatility clustering,autocorrelation and leverage effect can be exactly explained by the ARMA(4,3)-GJR(1,1)-M model.Meanwhile,the volatility has significant affection on the stock return in this model.The empirical result shows that the ARMA-GJR-M model is a more precise model to fit the series than the GJR-M model.

Development and Application of the Grey Forecasting System Based on MATLAB/GUI

Abstract: For the application of using GUI developing system in the economic field,grey forecasting system,based on the grey system theory,was developed by MATLAB GUI through the design of control unit and programming of callback function.The system can get the results of GM(1,1)model,including parameter estimation test,fitting and data forecasting.It solves complex issues including modeling and solving.Simultaneously,it was tested by data of Gross Domestic Product from 2003 to 2010.The result of test shows that grey forecasting system is easy to operate.It can realize GM(1,1)model and relevant results accurately.This study improves the utilization of gray prediction model.

Based on BD and QR for Research and Design of AGV

Abstract: With the development of industrial automation equipment,and constantly improve the level of logistics and transport requirements,the traditional sense of the AGV have been given new tasks and requirements,intelligent,automation,high efficiency is the direction of its future development,to solve the current AGV can not meet the full range of navigation problems at the same time,indoor and outdoor.A comprehensive study and design of indoor and outdoor AGV system based on BD and QR codes,the Beidou navigation precision difference of indoor and outdoor navigation smooth handover location,visual recognition of QR code combined with navigation technology,developed with no full transportation,intelligent path planning and obstacle avoidance and scheduling functions such as industrial indoor unguided the transport device,successfully applied to the warehouse cargo directly.

Linear Motor Based on AMEsim Modeling and Flow Characteristic Research of Reciprocating Pump

Abstract: Traditional rotary motor is complex and not easy to regulate and contro.Based on characteristics of linear motors,this is a research of linear motor that directly drives the piston rod of reciprocating pump to do reciprocating motion.It establishes the motion model of a reciprocating pump system,and uses AMEsim to simulate according to the traditional law of reciprocating movement of the pumping system.The simulation results show that,using reasonable control system,linear motor piston reciprocating pump performance motion such as displacement,velocity,acceleration,and pump flow rate output are more stable.This study theoretically and basically eliminates the reciprocating pump output flow "pulse",which can meet the requirements of modern machinery for reciprocating pumps,and it has some significance in promoting the application of linear motor reciprocating pump.

Study on Response Surface Model of Actual Power Consumption of Electric Buses

Abstract: In order to analyze the power consumption of electric buses,the Response surface method of power consumption is established by using the stop times,working time,distance and the temperature of the battery as the design variables according to the statistical data form the Qingdao Xuejiadao filling station,which could analyze the relationship between consumption with its influencing factorsThe analysis results show that the two function of the images between consumption and its design variables have been drawn by using MATLAB,which can reflect the relationship between electricity consumption and various parameters intuitively and quantitativelyThe model has a high accuracy and reliability of actual power consumption of electric buses,which plays an important indication in the operation of electric bus and in the infrastructure construction of the charging station