Hua Leng¹, Silin He², Jian Qiu³, Feng Liu^4,*, Xinfei Huang⁴, Jiran Zhu²

Energy Engineering, Vol.121, No.1, pp. 77-94, 2024, DOI:10.32604/ee.2023.028340

Abstract The distribution network exhibits complex structural characteristics, which makes fault localization a challenging task. Especially when a branch of the multi-branch distribution network fails, the traditional multi-branch fault location algorithm makes it difficult to meet the demands of high-precision fault localization in the multi-branch distribution network system. In this paper, the multi-branch mainline is decomposed into single branch lines, transforming the complex multi-branch fault location problem into a double-ended fault location problem. Based on the different transmission characteristics of the fault-traveling wave in fault lines and non-fault lines, the endpoint reference time difference matrix S and the fault time difference… More >

Yu Tang¹, Jingcun Yu¹, Benyu Su^1,3,*, Zhixiong Li²

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.3, pp. 679-688, 2022, DOI:10.32604/fdmp.2022.019609

Abstract The complex resistivity of coal and related rocks contains abundant physical property information, which can be indirectly used to study the lithology and microstructure of these materials. These aspects are closely related to the fluids inside the considered coal rocks, such as gas, water and coalbed methane. In the present analysis, considering different lithological structures, and using the Cole-Cole model, a forward simulation method is used to study different physical parameters such as the zero-frequency resistivity, the polarizability, the relaxation time, and the frequency correlation coefficient. Moreover, using a least square technique, a complex resistivity “inversion” algorithm is written. The… More >

Xian Zhou¹, Fei Wang², Ziyu Wang³, Yunfeng Xu^1,*

Energy Engineering, Vol.119, No.2, pp. 653-664, 2022, DOI:10.32604/ee.2022.019072

Abstract The reservoir is the networked rock skeleton of an oil and gas trap, as well as the generic term for the fluid contained within pore fractures and karst caves. Heterogeneity and a complex internal pore structure characterize the reservoir rock. By introducing the fractal permeability formula, this paper establishes a fractal mathematical model of oil-water two-phase flow in an oil reservoir with heterogeneity characteristics and numerically solves the mathematical model using the weighted least squares meshless method. Additionally, the method’s correctness is verified by comparison to the exact solution. The numerical results demonstrate that the fractal oil-water two-phase flow mathematical… More >

Duolu Mao^1,*, Kaiyong Li¹, Yaping Mao²

Journal of New Media, Vol.2, No.4, pp. 167-172, 2020, DOI:10.32604/jnm.2020.012816

Abstract In order to improve the accuracy of wireless network positioning, the triangulation method of wireless network positioning technology is proposed, which is based on the linear least square fitting method. It makes the observed value and the fitting value very close, effectively solves the problem of significant contradiction between the fitting result and the observed value in the principle of least square method, and can realize the accurate measurement of geographic information by wireless network positioning technology. More >

Seyed Salman Hosseini¹, Javad Marzbanrad^2,*

Sound & Vibration, Vol.53, No.6, pp. 297-308, 2019, DOI:10.32604/sv.2019.07434

Abstract In this paper; the dynamic characteristics of a semi-active magnetorheological fluid (MRF) engine mount are studied. To do so, the performance of the MRF engine mount is experimentally examined in higher frequencies (50~170 Hz) and the various amplitudes (0.01 ~ 0.2 mm). In such an examination, an MRF engine mount along with its magnetically biased is fabricated and successfully measured. In addition, the natural frequencies of the system are obtained by standard hammer modal test. For modelling the behavior of the system, a mass-spring-damper model with tuned PID coefficients based on Pessen integral of absolute error method is used. The… More >