Subjective and objective analysis on the sound quality of automotive wiper system

Car interior noise induced by windshield wiper system is tested for four different types of cars under high and low wiping speeds,and sound samples for subjective annoyance study are prepared. Grouped pair-wise comparison is adopted for the subjective evaluation test. The characteristic of subjective values and relation of four psychoacoustic parameters to the subjective annoyance are analyzed in two wiping speeds and various wiping patterns. The results indicate that the annoyance caused by wiper noise at high speed is higher than that at low speed,and downwards wiping noise is more annoying than upwards wiping noise. The work concluded that the subjective annoyance of noise from wiper system could be described by binaural loudness and fluctuation.     

Design and implementation of comprehensive evaluation model for long distance oil-gas pipeline

Existing pipeline safety evaluation models commonly use the subjective methods such as the expert evaluation method, but the subjective consciousness has serious influence on the determination of index weight. Therefore, the match degree of the evaluation and the real condition is low and the evaluation result lacks of comprehensiveness. This paper determines the major evaluation index of long-distance oil-gas pipelines through the analysis of the goals and features of the safety evaluation. Fuzzy mathematics method is applied to build the comprehensive evaluation model of long-distance oil-gas pipelines and to analyze the key technology of the evaluation model. Variation coefficient method and analytic hierarchy process are comprehensively utilized to make a quantitative analysis of the criteria layer weight, and preferential relation matrix and fuzzy consistent matrix are established to determine the index layer weight. Finally, some examples are given to verify the feasibility and accuracy of the proposed model.     

Analysis and Research on VVT System Control Strategy for Motorcycle Engine

An original variable valve timing mechanism with two-mode intake timing parameters is developed according to the structural characteristics of small-medium displacement motorcycle engine. Based on cycle simulation, a cycle simulation model of VVT mechanism for motorcycle engine is created. The control strategy of variable valve timing and lifting running-model are carried out at idle speed low negative load, middle negative load, low speed high negative load and high speed high negative load. It has been proved that the performance of JH125 motorcycle engine can be effectively improved by loading the new type VVT system.     

Identification of combustion noise and mechanical noise in internal combustion engine

To identify internal combustion engine (IC engine) noise, a mathematical model is established, and the corresponding program is developed. By introducing global thresholds to decrease noise in the wavelet transforms program, the anti-interference of the program can be guaranteed, the spectrums of the combustion noise and mechanical noise are separated, and their A-weighted sound power levels are figured out. Taking a CG125 style motorcycle engine for an example, theoretical examples that include different interferential noises are constructed to simulate the identification and to validate the accuracy and practicability of the program. Results of the identification show that the spectrums of the combustion noise and mechanical noise before and after separation are agreed well; errors of A-weighted sound power level are all less than 0.6 dB.     

Quality Evaluation Indicators for Urban Sideway Traffic Road Lighting

CIE has proposed the semi-cylindrical illuminations as evaluation indicators and the overseas reports nave also been put forward in the use of three-dimensional sense indicators to prevent violations based on the assessment of lighting to create efficient, economic, safe and comfortable urban traffic lighting environments. But this required experimental verifications. The study used subjective and objective experiment methods to survey the parts of the sidewalk lighting in Chongqing urban. Through extensive testing information disposals and analyses, the autrors illumination should be the optimal parameters of sidewalk lighting and exist problems at present. The computer gray separation method is first used in analysing the facial features of pedestrians at night. It gets the scope of applications and application conditions of three-dimensional sense. The study provide an experimental basis and scientific method for constituting sidewalk lighting evaluation indicators, and provided important values for the study of sidewalk lighting evaluation indicators.     

Hierarchy Group Decision-making Method of Evaluation of Residential Areas Architecture Design Schemes

For incarnating the effects of the preference of the potential users of residential areas or decision makers on the evaluation of architecture design schemes,a two hierarchy multi-attribute group decision model is established.How to obtain the decision matrix of expert evaluation incarnates the influence of difference of professional knowledge among experts on decision.Multi-attribute decision making method based on uncertain linguistic assessment is used to determine the users' preference on schemes.The weight of attributes is determined by a optimization model that makes the difference of attribute assessment between expert and user minimum,and those weights are used in expert decision.This can enable the model to reflect correctly the actual situation of such decision making question.     

Application of AHP-ATA in Elevator Risk Assessment

To analyze the safety of elevator system quantitatively, the risk factor weights aiming at the risk evaluation for elevator system are analyzed based on Analytic Hierarchy Process (AHP) in this paper. The Accident Tree Analysis (ATA) is also introduced to analyze accidents leading to the dangers during elevator running as the basis of weight assignment. The risk evaluation model of elevator system is built and its safety grade is set. The quantitative assessment for elevator system through linear weighted sum law is implemented. This method combining AHP and ATA in this paper avoids subjectivity and one-sidedness of weights indexes caused by expert-scoring method. This elevator system risk evaluation system provides feasible method of assessing safety grade subjectively.     

Simulation of regulatory driving cycle for motorcycle on the engine test bench

Dynamic performance test methods and experiments of motorcycle engine are investigated. The models of clutch, transmission and brake are simulated by changing the resistance torque imposed by the dynamometer to the engine and with the moment of inertia and road resistance data, the model of a 125 mL motorcycle is established on the dynamic engine test bench. On this basis, the road tests are simulated with models of different inertial mass. Compared with the experiments on the drum tester, the results show that when the inertial mass is set to 1.1 times the datum mass of the motorcycle, the deviations of its maximum speed, sliding distance and acceleration time are no more than 3% and the fuel consumption of 100 km is no more than 5% except the speed of 35 km/h. Through driver operational model, the effect of different gear change models on vehicle acceleration performance is studied. Finally, the regulatory driving cycle for motorcycle is implemented on the dynamic bench and the measurements show that it has high ability to accurately control speed.     

Measurements of Influent COD Components for Activated Sludge Models

The Activated Sludge Models were widely applied in Europe and America since they were put forward, however, for an accurate simulation of the activated sludge treatment processes, reliable wastewater characteristic parameters such as COD components were needed. The conventional parameters such as COD can not differentiate the carbonaceous organic matters of wastewater, so they need to be divided again. Therefore, the fractionation of influent COD components in the Activated Sludge Models is introduced, and the physical-chemical and biological characteristics of each COD components are analyzed. The measurements of influent COD components are reviewed and some evaluation is made. The issue in determining the influent COD components is discussed. The idea of establishing a characterization guideline is put forward at last.     

Strengthening of Emission Controlling for Small and Medium Sized Motorcycle Engine

It is very difficult for small and medium sized motorcycle engine to use the combination of closed-loop control electronic fuel injection system and three-way catalytic converter for emission controlling due to the high cost. In order to strengthen emission controlling of the carburetor motorcycle engines, the metering characteristics of carburetor are adjusted, combustion chamber as well as intake and exhaust ducts are further optimized, and secondary air injection system and oxidation type catalytic converter are developed, and moreover a simplified positive crankcase ventilator is employed to eliminate the gas blowby from crankcase. It is verified by test cycle testing that pollutant emissions of the carburetor motorcycle engines can be effectively controlled within the emissions limits by taking the above technical approaches.     

Application of Sound Intensity Technique to Measure the Noise of Electromotor

This paper has explained the characteristics,virtue of sound intensity measurement and the principle. And compare with traditional sound pressure measurement. The principle and composing of virtual sound intensity measurement system based on two-channel FFT analysis are researched. The sound power of large turbogeneratorin operating site is determined by means of sound intensity measurement and sound pressuremeasurement. Itis demonstrated that the method of sound intensity measurement of engine is practicable and the measuring data are valid and the method conquers the problems of traditional method of sound pressure measurement which is apt to environmentinfluence and sound power measurement need to especially acoustic environment. It is proved that the sound intensity method is especially suited to determine highaccuratelythe sound Power level of the electrical machines operating in situated conditions especially in case of acoustically worst environments or on loadand themethod is so superiorityin noise measurement.     

Numerical analysis of noise radiation from motorcycle engine shell

FEM/BEM (Finite Element Method/Boundary Element Method) mode analysis of the noise radiation from motorcycle engine shell is conducted. The natural frequency is compared between FEM/BEM analysis and experimental analysis. The FEM/BEM results are agreed with the experiment results, which proves that the finite element model is correct. The frequency response is analyzed and the structure’s noise radiation is simulated by means of FEM/BEM, in order to predict the noise radiation from the motorcycle engine shell and gain the sound field characteristic outside the structure. The calculation data is compared with the experiment data in different frequency bands. The result shows high accordance, which indicates that this method is effective.     

Financial SEM Analyzing on Stock Evaluation in Circulation of China

Now the appraisement of stock market of China is still in the exploring phases. When stocks are appraised, people usually use expert-method or history-method aiming at different factors, especially the confirming of the factors that affect the stock evaluation and the interaction between different factors are not analyzed quantitatively, resulting in the stagnation of next researches on the whole.By applying the SEM to stock evaluation of Chinese stock market, we build a financial structural model, analyzes the influence to stock evaluation of each factor and build the experience mode value of stock evaluation of China. This can be consulted by stock evaluation and credit evaluation of China.     

Analysis of comprehensive evaluation method on safety of mountain tunnel initial support

Through collecting and collating information of 62 tunnels with initial support fracture,the risk grade is summed up,the factors causing initial support fracture are divided into two types：objective factors and subjective factors. The statistical results show that the proportion of controlled subjective factors’ reached as large as 25%. The comprehensive evaluation model on safety of mountain tunnel initial support by analytic hierarchy process (AHP)and fuzzy comprehensive evaluation is established. On this basis,the science rational risk response method is required. Then the evaluation model is proved credible by field measurements.     

Intelligent optimization design of novel flash structure for crank-shaft forging dies

The parameters of resistance wall, which is a novel flash structure for forging die, are studied. The effects of the resistance walls parameters are analyzed and the important influence factors are screened by using the fractional factorial design. The Latin hypercube method is used to select sample points of the important design variables which are analyzed by finite elements simulation. The surrogate models are established by taking the simulation result as response and the parameters of the resistance wall structure as variables. The model is converted into single objective function by linear weighting method and is optimized by using particle swarm optimization algorithm for global optimization. Finally,the optimization results are compared and verified with those obtained by genetic algorithm. The results show that the PSO (particle swarm optimization) algorithm has better convergence than the traditional genetic algorithm and can realize optimization of the parameters of the resistance wall structure.     

Finite Element Reliability Analysis of the Stability of a Slope

The whole reliability index of a slope is derived through using the strength reduction method in the finite element analysis, which can make use of the former finite element program and can be used to both linear and nonlinear finite element analysis. The affection of the evaluation of derivative and the selection of reliability analysis methods is discussed, which shows that it is very important to select the type of limit state function of the slope stability. A new iterafive formula, which can consider the correlation of fundamental parameters, is proposed for FORM, and the convergence is very well.     

Analyse of Compressor Sound Quality

By of Stevens steady wide frequency noise loudness and Fastl total sensation noise calculation method, sound quality evaluation of the noise left and back-end face was studied before the compressor improved and after the minipore muffler installed. The research indicates that the compressor noise is reduced, at the same time, the loudness left the compressor and the back - end face is reduced by 10.25 sone and 13.3 sone respectively. The rate reduced is over 40%. The total sensation noise is reduced by 12.5 noy and 15 noy, the rate achieved is over 45%. It is very perfect to improve the compressor sound quality with the use of minipore muffler.     

A FUZZY COMPREHENSIVE EVALUATION METHOD BASED ON STANDARD INDEXES

A method of fuzzy comprehensive evaluation based on standard indexes is presented. This method regards all sorts of standard indexes of evaluation objects as basic evaluation standards. Its main setps are: (1 )obtain evaluation parameters(all kinds of parameters which decide main performances of evaluation objects)and set up evaluation parameter matrix; (2) determine satisfaction degrees of various parameters and set up satisfaction degree matrix; (3) determine the weight of various prarmeters and set up the weight set; (4) make comprehensive evaluation and obtain evaluation result. Its common program is worked out and the typical example is presented.     

The Geometric precision and Performance Analysis for machining Surface based on Fractals

A new analysis method for machining surface profile error is presented in this paper.The linear regression and nonlinear regression are first applied respectively,and then the Weierstrass Mandebrot fractal function is used to obtain the fractal parameters of machining profiles.A minimal parameter set which depicts the machining surface geometric precision is set up,and the surface profile can be reconstructed using these parameters,and an analysis method for part performance and its tolerance structure is proposed.Examples are provided to illustrate the method is feasible and effective.     

Analysis of personnel evacuation simulation at an elevated light railway station

To study the process of personnel evacuation at light railway stations, make the personnel evacuation plan and optimize the architectural design, the simulation model and program of personnel evacuation are improved. The stair is treated as a separate space unit and a residual value is used to gather the advantages of grid model and the continuity of occupant’s movement. Through questionnaire surveys and field observations at elevated light railway stations in Chongqing, the passengers’ personal parameters and the response characteristics to fire are obtained. The tested movement speed of people agrees to the empirical data. The process of personnel evacuation and the location of each person at any time are demonstrated dynamically by using the computer-programming Zone Grid Evacuation Simulation Software (ZGESS) on the platform of MATLAB. Meanwhile, the total evacuation time is calculated by the program, and it is the same with the data of observation approximately.