Xiaoxia Yang¹, Shili Chen¹, Fang Sun¹, Shijiu Jin¹, Wenshuang Chang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.90, No.6, pp. 487-500, 2013, DOI:10.3970/cmes.2013.090.487

Abstract Ultrasonic phased array inspection technology is widely used in nondestructive evaluation (NDE) applications and it has been proved to be an effective method for flaw detections in industry. In our study, this nondestructive evaluation method is proposed to detect the corrosion defects on engine cylinders. In order to demonstrate its feasibility, it is necessary to study the characteristics of the acoustic field produced by a linear phased array ultrasonic transducer in the engine cylinders. In this paper, according to multi-Gaussian beam model and ray acoustics theory, we derive the expression of the acoustic field from a linear phased array ultrasonic… More >

Ying Li¹, Jianbo Li^1,*, Jianwei Chen¹, Minchao Lu¹, Caoyuan Li^2,3

CMC-Computers, Materials & Continua, Vol.57, No.3, pp. 571-587, 2018, DOI:10.32604/cmc.2018.02851

Abstract The explosive growth of mobile data demand is becoming an increasing burden on current cellular network. To address this issue, we propose a solution of opportunistic data offloading for alleviating overloaded cellular traffic. The principle behind it is to select a few important users as seeds for data sharing. The three critical steps are detailed as follows. We first explore individual interests of users by the construction of user profiles, on which an interest graph is built by Gaussian graphical modeling. We then apply the extreme value theory to threshold the encounter duration of user pairs. So, a contact graph… More >