Iterative coupling of precise integration FEM and TD-BEM for elastodynamic analysis

Weidong Lei,Chun Liu,Xiaofei Qin,Rui Chen 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.67 No.4

The iterative decomposition coupling formulation of the precise integration finite element method (FEM) and the time domain boundary element method (TD-BEM) is presented for elstodynamic problems. In the formulation, the FEM node and the BEM node are not required to be coincident on the common interface between FEM and BEM sub-domains, therefore, the FEM and BEM are independently discretized. The force and displacement converting matrices are used to transfer data between FEM and BEMnodes on the common interface between the FEM and BEM sub-domains, to renew the nodal variables in the process of the iterations for the un-coincident FEM node and BEM node. The iterative coupling formulation for elastodynamics in current paper is of high modeling accuracy, due to the semi-analytical solution incorporated in the precise integration finite element method. The decomposition coupling formulation for elastodynamics is verified by examples of a cantilever bar under a Heaviside-type force and a harmonic load.

Iterative coupling of precise integration FEM and TD-BEM for elastodynamic analysis

Lei, Weidong,Liu, Chun,Qin, Xiaofei,Chen, Rui Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.67 No.4

The iterative decomposition coupling formulation of the precise integration finite element method (FEM) and the time domain boundary element method (TD-BEM) is presented for elstodynamic problems. In the formulation, the FEM node and the BEM node are not required to be coincident on the common interface between FEM and BEM sub-domains, therefore, the FEM and BEM are independently discretized. The force and displacement converting matrices are used to transfer data between FEM and BEM nodes on the common interface between the FEM and BEM sub-domains, to renew the nodal variables in the process of the iterations for the un-coincident FEM node and BEM node. The iterative coupling formulation for elastodynamics in current paper is of high modeling accuracy, due to the semi-analytical solution incorporated in the precise integration finite element method. The decomposition coupling formulation for elastodynamics is verified by examples of a cantilever bar under a Heaviside-type force and a harmonic load.

A Hybrid Modulation Strategy with Reduced Switching Losses and Neutral Point Potential Balance for Three-Level NPC Inverter

Weidong Jiang,Yan Gao,Jinping Wang,Lei Wang 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

In this paper, carrier-based pulse width modulation (CBPWM), space vector PWM (SVPWM) and reduced switching losses PWM (RSLPWM) for the three-level neutral point clamped (NPC) inverter are introduced. In the case of the neutral point (NP) potential (NPP) offset, an asymmetric disposition PWM (ASPDPWM) strategy is proposed, which can output PWM sequences correctly and suppress the lower order harmonics of the inverter effectively. An NPP balance strategy based on carrier based PWM (CBPWM) is analyzed. A hybrid modulation strategy combining RSLPWM and the NPP balance based on CBPWM is proposed, and hysteresis control is adopted to switch between the two modulation strategies. An experimental prototype of the three-level NPC inverter is built. The effectiveness of the hybrid modulation is verified with a resistance-inductance load and a permanent magnetic synchronous motor (PMSM) load, respectively. The experimental results show that reduced switching losses and an acceptable NPP can be effectively achieved in the hybrid modulation strategy.

Honokiol Suppresses Renal Cancer Cells’ Metastasis via Dual-Blocking Epithelial-Mesenchymal Transition and Cancer Stem Cell Properties through Modulating miR-141/ZEB2 Signaling

Weidong Li,Qian Wang,Qiaozhen Su,Dandan Ma,Chang An,Lei Ma,Hongfeng Liang 한국분자세포생물학회 2014 Molecules and cells Vol.37 No.5

Renal cell carcinoma (RCC) is associated with a high frequency of metastasis and only few therapies substantially prolong survival. Honokiol, isolated from Magnolia spp. bark, has been shown to exhibit pleiotropic anticancer effects in many cancer types. However, whether honokiol could suppress RCC metastasis has not been fully elucidated. In the present study, we found that honokiol suppressed renal cancer cells’ metastasis via dual-blocking epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) properties. In addition, honokiol inhibited tumor growth in vivo. It was found that hono-kiol could up-regulate miR-141, which targeted ZEB2 and modulated ZEB2 expression. Honokiol reversed EMT and suppressed CSC properties partly through the miR-141/ZEB2 axis. Our study suggested that honokiol may be a suitable therapeutic strategy for RCC treatment.

A Hybrid Modulation Strategy with Reduced Switching Losses and Neutral Point Potential Balance for Three-Level NPC Inverter

Jiang, Weidong,Gao, Yan,Wang, Jinping,Wang, Lei The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

In this paper, carrier-based pulse width modulation (CBPWM), space vector PWM (SVPWM) and reduced switching losses PWM (RSLPWM) for the three-level neutral point clamped (NPC) inverter are introduced. In the case of the neutral point (NP) potential (NPP) offset, an asymmetric disposition PWM (ASPDPWM) strategy is proposed, which can output PWM sequences correctly and suppress the lower order harmonics of the inverter effectively. An NPP balance strategy based on carrier based PWM (CBPWM) is analyzed. A hybrid modulation strategy combining RSLPWM and the NPP balance based on CBPWM is proposed, and hysteresis control is adopted to switch between the two modulation strategies. An experimental prototype of the three-level NPC inverter is built. The effectiveness of the hybrid modulation is verified with a resistance-inductance load and a permanent magnetic synchronous motor (PMSM) load, respectively. The experimental results show that reduced switching losses and an acceptable NPP can be effectively achieved in the hybrid modulation strategy.

Honokiol Suppresses Renal Cancer Cells' Metastasis via Dual-Blocking Epithelial-Mesenchymal Transition and Cancer Stem Cell Properties through Modulating miR-141/ZEB2 Signaling

Li, Weidong,Wang, Qian,Su, Qiaozhen,Ma, Dandan,An, Chang,Ma, Lei,Liang, Hongfeng Korean Society for Molecular and Cellular Biology 2014 Molecules and cells Vol.37 No.5

Renal cell carcinoma (RCC) is associated with a high frequency of metastasis and only few therapies substantially prolong survival. Honokiol, isolated from Magnolia spp. bark, has been shown to exhibit pleiotropic anticancer effects in many cancer types. However, whether honokiol could suppress RCC metastasis has not been fully elucidated. In the present study, we found that honokiol suppressed renal cancer cells' metastasis via dual-blocking epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) properties. In addition, honokiol inhibited tumor growth in vivo. It was found that honokiol could upregulate miR-141, which targeted ZEB2 and modulated ZEB2 expression. Honokiol reversed EMT and suppressed CSC properties partly through the miR-141/ZEB2 axis. Our study suggested that honokiol may be a suitable therapeutic strategy for RCC treatment.

Balantidium honghuensis n. sp. (Ciliophora: Trichostomatidae) from the Rectum of Rana nigromaculata and R. limnocharis from Honghu Lake, China

Ming Li,Weidong Li,Lei Zhang,Chong Wang 대한기생충학열대의학회 2013 The Korean Journal of Parasitology Vol.51 No.4

Nanoscale cryptography: opportunities and challenges

Masoumi Massoud,Shi Weidong,Xu Lei 나노기술연구협의회 2015 Nano Convergence Vol.2 No.21

While most of the electronics industry is dependent on the ever-decreasing size of lithographic transistors, this scaling cannot continue indefinitely. To improve the performance of the integrated circuits, new emerging and paradigms are needed. In recent years, nanoelectronics has become one of the most important and exciting forefront in science and engineering. It shows a great promise for providing us in the near future with many breakthroughs that change the direction of technological advances in a wide range of applications. In this paper, we discuss the contribution that nanotechnology may offer to the evolution of cryptographic hardware and embedded systems and demonstrate how nanoscale devices can be used for constructing security primitives. Using a custom set of design automation tools, it is demonstrated that relative to a conventional 45-nm CMOS system, performance gains can be obtained up to two orders of magnitude reduction in area and up to 50 % improvement in speed.

Distribution characteristics and processes along flow paths of shallow groundwater in the Tan-Lu fault zone in Anhui province, China

Dejian Wang,Jiazhong Qian,Weidong Zhao,Xiaoliang Hou,Wei Wang,Lei Ma 한국지질과학협의회 2022 Geosciences Journal Vol.26 No.4

To disclose the distribution characteristics, the situation of flow and storage, and processes along flow paths of shallow groundwater in Tan-Lu fault zones, nine hundred and seven groundwater table elevations data and one hundred hydrochemical samples of shallow groundwater were taken from the Tan-Lu fault zone in Anhui province to analyze the characteristic of groundwater distribution. The geographic information system (GIS) method was used to analyze the spatial distribution characteristics of groundwater tables, total dissolved solids (TDS) and chloride ion (Cl−). Geophysical prospecting, drilling material and regional hydrogeological survey were utilized to disclose groundwater storage and flow regime in the fault zone. The results show that the Tan-Lu fault zone in Anhui province has controlled groundwater flow into the Jiashan basin, Hefei basin, Chaohu area and Qianshan basin, which developed from north to south in this area. Groundwater in theses basins have recharged from surrounding areas to form a water storage space. Geophysical prospecting and drilling technology revealed that the Tan-Lu fault zone provided a flow channel and storage space for groundwater. Faults provide preferential channels in some areas for the groundwater flow and circulation, eventually deep hot-water flows upward and discharges in the form of hot-springs. The identification of the groundwater flow pathway can help to provide a reliable scientific basis for regional spatial development and utilization of groundwater resources.

Objective Evaluation of Fabric Wrinkles Based on 2-D Gabor Transform

Kangjun Shi,Jingan Wang,Lei Wang,Ruru Pan,Weidong Gao 한국섬유공학회 2020 Fibers and polymers Vol.21 No.9

In order to establish an objective, stable and efficient wrinkle evaluation system for fabric wrinkle evaluation, amethod based on 2-D Gabor transform was proposed. Among this system, the directions of Gabor filter were determinedaccording to the range of amplitude response. Then a set of Gabor filters were obtained by selecting and optimizing thecentral frequency, the half peak bandwidth and the shape factor of the Gaussian surface. After Gabor transform by such filterbank, the amplitudes of different response spectrums were extracted, constructing a multi-dimensional feature vector. Finally,the feature vectors of the fabric image samples, whose wrinkle degrees were evaluated manually in advance, were extractedand used to train a support vector machine (SVM), which achieved 81.82 % evaluation accuracy on the 345 samples. Thetrained SVM was applied to evaluate the wrinkle degree of the fabric samples acquired in different illumination directions,and verified the stability of the proposed method to illumination environment. Compared with the existing method, theproposed method has higher classification accuracy. The comparison results indicate the Gabor amplitude feature proposedby this research has a high correlation with the fabric wrinkle grades.