Chengdu, China
Chengdu, China

Xihua University is a university in Sichuan province, People's Republic of China. Approved by the State Ministry of Education, Xihua University was founded on April 16, 2003, formed by the merger of the former Sichuan University of Science and Technology and the former Teacher's College. The former Sichuan University of Science and Technology, once called the Sichuan Mechanical College of Agriculture, was founded in 1960. The former Teacher's College, located in Peng Zhou County, was founded in 1971. Wikipedia.

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Liu L.,Xihua University
Advances in Intelligent Systems and Computing | Year: 2017

Financing risks evaluation of green residential buildings is conducted in this paper, based on fuzzy comprehensive evaluation method. The Chengdu Langshi green blocks project is used as a case-study for evaluating financing risks. The results show that real estate development enterprises of Sichuan province are of greater financing risks. The most influential risk factors are laws and policies, enterprise financial position, corporate reputation, enterprise management, macroeconomics, and industry competition, in that order. The results demonstrate measurement of financing risks using a case study, which is useful for the financing risk management of green residential buildings. © Springer Science+Business Media Singapore 2017.

Chen H.,Xihua University
Journal of Convergence Information Technology | Year: 2012

Mammography is the most effective method for early breast cancer detection and diagnosis. Extraction of the breast profile region is helpful for the radiologist screening, and is also an essential preprocessing step for computer aided diagnosis (CAD). This paper proposed a fast classification mask construction algorithm, first to perform initial breast segmentation with optimal threshold combined with an area classifier at low image resolution, then make use of Dijkstra searching method to retrieve the accurate breast profile at the original resolution, finally, a classification mask for the mammogram is constructed. Experiment shows this algorithm can extract breast profile region from raw mammogram data fast, robustly and accurately.

Zhang J.,Xihua University | Du X.,Missouri University of Science and Technology
Journal of Mechanical Design, Transactions of the ASME | Year: 2011

A function generator mechanism links its motion output and motion input with a desired functional relationship. The probability of realizing such functional relationship is the kinematic reliability. The time-dependent kinematic reliability is desired because it provides the reliability over the time interval where the functional relationship is defined. But the methodologies of time-dependent reliability are currently lacking for function generator mechanisms. We propose a mean value first-passage method for time-dependent reliability analysis. With the assumption of normality for random dimension variables with small variances, the motion error becomes a nonstationary Gaussian process. We at first derive analytical equations for upcrossing and downcrossing rates and then develop a numerical procedure that integrates the two rates to obtain the kinematic reliability. A four-bar function generator is used as an example. The proposed method is accurate and efficient for normally distributed dimension variables with small variances. © 2011 American Society of Mechanical Engineers.

Xu Y.,Xihua University
Optics Communications | Year: 2014

The phase-locking of the radial array CO2 laser (RAL) is introduced based on the injection-locking principle. The characteristic parameters of laser beams used in the phase-locking are described, and the coupling coefficient c00 between the injected mode and the eigenmode of RAL is calculated. The laser modes from RAL are the low-order Hermite Gaussian modes due to the diffraction loss. The analytical formula for the output beam through an ABCD optical system is derived according Collins formula. The numerical examples are given to illustrate our analytical results. © 2014 Elsevier B.V.

Xu Y.,Xihua University
Optics Communications | Year: 2014

A new type of laser resonator is presented to obtained good coherent beam and the parameters of the laser beam are calculated. The principle of phase-locking is described based on the injection-locking, the properties of the injected beam in the resonator are studied in detail. The output beam from output mirror is an annular laser beam with zero central intensity. An analytical expression for the annular laser beam through the ABCD optical system is derived. Typical numerical examples are calculated to confirm our analytical results. It is shown that the good coherent beam can be obtained through phase-locking, and the central intensity of annular beam through ABCD optical system will become maximum when the parameters of laser beam are selected reasonably. © 2014 Elsevier B.V.

Xu Y.,Xihua University
Optics Communications | Year: 2013

The analytical formula of elegant Laguerre Gaussian beam (ELGB) through the misaligned optical system is derived by using the diffraction integral equation. Based on the formula, the propagation properties of ELGB are studied in detail, the numerical examples are given to confirm the correctness of our calculated results. It is shown that the parameters (La, θa,φ,z,m) will influence the intensity distributions and beam shapes of ELGB, these results are useful in the application of laser beams. © 2013 Elsevier B.V.

Meng D.,Southwestern University of Finance and Economics | Pei Z.,Xihua University
Information Sciences | Year: 2013

We generalize linguistic evaluation values and their weights in group decision-making (GDM) problems based on unbalanced linguistic terms. The GDM problems include two types of weights: belief degrees of linguistic evaluation values and experts' weights. Due to the time pressure and conflict of multi-source of information, etc., experts may have various evaluations values on alternatives. The belief degree is used to represent the confidence level of the values. The experts' weight is used to represent the differences among experts' importance which caused by experts' experience or knowledge distinction. We propose the weighted unbalanced linguistic aggregation operators to synthesize linguistic evaluation value, belief degree and experts' weights. Some desired properties of the operator are then studied, these properties show that the operator extends the linguistic weighted averaging operator (LWA) and the linguistic ordered weighted averaging (LOWA) operator. Finally, an illustrative example of human resource performance appraisal based on the linguistic aggregation operator is provided. © 2012 Elsevier Inc. All rights reserved.

The analytical formula of radial array beams generated by radial array laser through misalignment of optical system is derived by using the diffraction integral equation. The propagation characteristics of radial array beams converged by the convergent optical system are studied. As the numerical examples, the influences of the two main parameters (the misalignment line deviation and angle deviation) on the light intensity are analyzed in detail. It is shown that the misalignment will lead to the increase of the light intensity of longitudinal lower-order Hermite-Gaussian beams (for example m=1, n=0), and the maximum light intensity (MLI) of the big misalignment (line deviation is 2 mm) is about 2 times higher than the small misalignment (line deviation is 1 mm). However, it will decrease for the transversal lower-order Hermite-Gaussian beams (for example m=0, n=1), and MLI of the small misalignment (line deviation is 1 mm) is about 2 times higher than the big misalignment (line deviation is 2 mm). The results are important for the laser rapid processing and high precision machining. © 2013 Elsevier Ltd.

Wang H.,Xihua University | Han G.,Chinese Academy of science
Atmospheric Research | Year: 2011

A comprehensive study on the chemical compositions of rainwater was carried out from Jan. to Dec. in 2008 in Chengdu, a city located on the acid rain control zone of southwest China. All samples were analyzed for pH and major ions (F-, Cl-, NO3-, SO42-, K+, Na+, Ca2+, Mg2+, and NH4+). The pH increased due to the result of neutralization caused by the base ions. It was observed that Ca2+ was the most abundant cation with a VWM value of 196.6μeq/L (17.3-1568.7μeq/L), accounting for 49.7% (9.4%-79.2%) of the total cations. SO42- was the most abundant anion with VWM value of 212.8μeq/L (41.8-1227.6μeq/L). SO42- and NO3- were dominant among the anions, accounting for 90.4%-99.1% of the total measured anions. The concentrations of NO3- were higher than the most polluted cities abroad, which indicated Chengdu has been a severe polluted city over the world. The high fuel consumption from urbanization and the rapid increase of vehicles resulted in the high emission of SO2 and NOx, which were the precursor of the high concentration of acidic ions NO3- and SO42-. It was the main reason of the severe acid rain in Chengdu. The high concentrations of alkaline ions (mainly Ca2+, NH4+) in Chengdu city atmosphere have played an important role to neutralize the acidity of rainwater and the pH value has increased by 0.7 units since 1989. It is worth noting that the emission of NOx from the automobile exhaust is increased and is becoming the important precursor of acid rain now. © 2010.

Xu Y.,Xihua University
Applied Optics | Year: 2014

The axes of a laser resonator will deviate away from the initial places when the combination-cylinder discharge CO2 laser (CCDCL) is misaligned. The new cavity axes are established through using the misaligned augmented matrixes. The influences of the misalignments on the properties of the laser beams are studied in detail, such as the line deviations and angle deviations of oscillation beams in CCDCL, the near- and far-field distribution of output beams, the diffraction loss and output power, and the beam quality factor. It is shown that the influences of the misalignments on the above properties of the laser beams are obvious when the misaligned angle of the laser resonator exceeds 30 s. The studied results can afford references for the design of a CCDCL. © 2014 Optical Society of America.

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