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.
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.
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.
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.
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.