Deformable Surface 3D Reconstruction from a Single Image by Linear Programming

( Wenjuan Ma ),( Shusen Sun ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.6

We present a method for 3D shape reconstruction of inextensible deformable surfaces from a single image. The key of our approach is to represent the surface as a 3D triangulated mesh and formulate the reconstruction problem as a sequence of Linear Programming (LP) problems. The LP problem consists of data constraints which are 3D-to-2D keypoint correspondences and shape constraints which are designed to retain original lengths of mesh edges. We use a closed-form method to generate an initial structure, then refine this structure by solving the LP problem iteratively. Compared with previous methods, ours neither involves smoothness constraints nor temporal consistency, which enables us to recover shapes of surfaces with various deformations from a single image. The robustness and accuracy of our approach are evaluated quantitatively on synthetic data and qualitatively on real data.

Interleaved High Step-Up Boost Converter

Ma, Penghui,Liang, Wenjuan,Chen, Hao,Zhang, Yubo,Hu, Xuefeng The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.3

Renewable energy based on photovoltaic systems is beginning to play an important role to supply power to remote areas all over the world. Owing to the lower output voltage of photovoltaic arrays, high gain DC-DC converters with a high efficiency are required in practice. This paper presents a novel interleaved DC-DC boost converter with a high voltage gain, where the input terminal is interlaced in parallel and the output terminal is staggered in series (IPOSB). The IPOSB configuration can reduce input current ripples because two inductors are interlaced in parallel. The double output capacitors are charged in staggered parallel and discharged in series for the load. Therefore, IPOSB can attain a high step-up conversion and a lower output voltage ripple. In addtion, the output voltage can be automatically divided by two capacitors, without the need for extra sharing control methods. At the same time, the voltage stress of the power devices is lowered. The inrush current problem of capacitors is restrained by the inductor when compared with high gain converters with a switching-capacitor structure. The working principle and steady-state characteristics of the converter are analyzed in detail. The correctness of the theoretical analysis is verified by experimental results.

Stability analysis of bimodular pin-ended slender rod

Wenjuan Yao,Jianwei Ma,Baolin Hu 국제구조공학회 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.40 No.4

Many novel materials, developed in recent years, have obvious properties with different modulus of elasticity in tension and compression. The ratio of their tensile modulus to compressive modulus is as high as five times. Nowadays, it has become a new trend to study the mechanical properties of these bimodular materials. At the present stage, there are extensive studies related to the strength analysis of bimodular structures, but the investigation of the buckling stability problem of bimodular rods seems to cover new ground. In this article, a semi-analytical method is proposed to acquire the buckling critical load of bimodular slender rod. By introducing non-dimensional parameters, the position of neutral axis of the bimodular rod in the critical state can be determined. Then by combining the phased integration method, the deflection differential equation of bimodular pin-ended slender rod is deduced. In addition, the buckling critical load is obtained by solving this equation. An example, which is conducted by comparing the calculation results between the three of the methods including the laboratory tests, numerical simulation method and the method we developed here, shows that the method proposed in the present work is reliable to use. Furthermore, the influence of bimodular characteristics on the stability is discussed and analyzed.

Multi-objective Fuzzy-optimization of Crowbar Resistances for the Low-Voltage Ride-through of Doubly Fed Induction Wind Turbine Generation Systems

Wenjuan Zhang,Haomiao Ma,Junli Zhang,Lingling Chen,Yang Qu 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.4

This study investigates the multi-objective fuzzy optimization of crowbar resistance for the doubly fed induction generator (DFIG) low-voltage ride-through (LVRT). By integrating the crowbar resistance of the crowbar circuit as a decision variable, a multi-objective model for crowbar resistance value optimization has been established to minimize rotor overcurrent and to simultaneously reduce the DFIG reactive power absorbed from the grid during the process of LVRT. A multi-objective genetic algorithm (MOGA) is applied to solve this optimization problem. In the proposed GA, the value of the crowbar resistance is represented by floating-point numbers in the GA population. The MOGA emphasizes the non-dominated solutions and simultaneously maintains diversity in the non-dominated solutions. A fuzzy-set-theory-based is employed to obtain the best solution. The proposed approach has been evaluated on a 3 MW DFIG LVRT. Simulation results show the effectiveness of the proposed approach for solving the crowbar resistance multi-objective optimization problem in the DFIG LVRT.

Nonlinear large deflection buckling analysis of compression rod with different moduli

Wenjuan Yao,Jianwei Ma,Jinling Gao,Yuanzhong Qiu 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.54 No.5

Many novel materials exhibit a property of different elastic moduli in tension and compression. One such material is graphene, a wonder material, which has the highest strength yet measured. Investigations on buckling problems for structures with different moduli are scarce. To address this new problem, firstly, the nondimensional expression of the relation between offset of neutral axis and deflection curve is derived based on the phased integration method, and then using the energy method, load-deflection relation of the rod is determined; Secondly, based on the improved constitutive model for different moduli, large deformation finite element formulations are developed and combined with the arc-length method, finite element iterative program for rods with different moduli is established to obtain buckling critical loads; Thirdly, material mechanical properties tests of graphite, which is the raw material of graphene, are performed to measure the tensile and compressive elastic moduli, moreover, buckling tests are also conducted to investigate the buckling behavior of this kind of graphite rod. By comparing the calculation results of the energy method and finite element method with those of laboratory tests, the analytical model and finite element numerical model are demonstrated to be accurate and reliable. The results show that it may lead to unsafe results if the classic theory was still adopted to determine the buckling loads of those rods composed of a material having different moduli. The proposed models could provide a novel approach for further investigation of non-linear mechanical behavior for other structures with different moduli.

Interleaved High Step-Up Boost Converter

Penghui Ma,Wenjuan Liang,Hao Chen,Yubo Zhang,Xuefeng Hu 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.3

Renewable energy based on photovoltaic systems is beginning to play an important role to supply power to remote areas all over the world. Owing to the lower output voltage of photovoltaic arrays, high gain DC-DC converters with a high efficiency are required in practice. This paper presents a novel interleaved DC-DC boost converter with a high voltage gain, where the input terminal is interlaced in parallel and the output terminal is staggered in series (IPOSB). The IPOSB configuration can reduce input current ripples because two inductors are interlaced in parallel. The double output capacitors are charged in staggered parallel and discharged in series for the load. Therefore, IPOSB can attain a high step-up conversion and a lower output voltage ripple. In addtion, the output voltage can be automatically divided by two capacitors, without the need for extra sharing control methods. At the same time, the voltage stress of the power devices is lowered. The inrush current problem of capacitors is restrained by the inductor when compared with high gain converters with a switching-capacitor structure. The working principle and steady-state characteristics of the converter are analyzed in detail. The correctness of the theoretical analysis is verified by experimental results.

Multi-objective Fuzzy-optimization of Crowbar Resistances for the Low-Voltage Ride-through of Doubly Fed Induction Wind Turbine Generation Systems

Zhang, Wenjuan,Ma, Haomiao,Zhang, Junli,Chen, Lingling,Qu, Yang The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.4

This study investigates the multi-objective fuzzy optimization of crowbar resistance for the doubly fed induction generator (DFIG) low-voltage ride-through (LVRT). By integrating the crowbar resistance of the crowbar circuit as a decision variable, a multi-objective model for crowbar resistance value optimization has been established to minimize rotor overcurrent and to simultaneously reduce the DFIG reactive power absorbed from the grid during the process of LVRT. A multi-objective genetic algorithm (MOGA) is applied to solve this optimization problem. In the proposed GA, the value of the crowbar resistance is represented by floating-point numbers in the GA population. The MOGA emphasizes the non-dominated solutions and simultaneously maintains diversity in the non-dominated solutions. A fuzzy-set-theory-based is employed to obtain the best solution. The proposed approach has been evaluated on a 3 MW DFIG LVRT. Simulation results show the effectiveness of the proposed approach for solving the crowbar resistance multi-objective optimization problem in the DFIG LVRT.

Stability analysis of bimodular pin-ended slender rod

Yao, Wenjuan,Ma, Jianwei,Hu, Baolin Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.40 No.4

Many novel materials, developed in recent years, have obvious properties with different modulus of elasticity in tension and compression. The ratio of their tensile modulus to compressive modulus is as high as five times. Nowadays, it has become a new trend to study the mechanical properties of these bimodular materials. At the present stage, there are extensive studies related to the strength analysis of bimodular structures, but the investigation of the buckling stability problem of bimodular rods seems to cover new ground. In this article, a semi-analytical method is proposed to acquire the buckling critical load of bimodular slender rod. By introducing non-dimensional parameters, the position of neutral axis of the bimodular rod in the critical state can be determined. Then by combining the phased integration method, the deflection differential equation of bimodular pin-ended slender rod is deduced. In addition, the buckling critical load is obtained by solving this equation. An example, which is conducted by comparing the calculation results between the three of the methods including the laboratory tests, numerical simulation method and the method we developed here, shows that the method proposed in the present work is reliable to use. Furthermore, the influence of bimodular characteristics on the stability is discussed and analyzed.

The effects of dantrolene and 2-aminoethoxydiphenyl borate (2-APB) on arsenic-induced osteoporosis

Qin Wenjuan,Feng Jia,Ma Rongji,Jiang Yufeng,Lv Hailong 대한독성 유전단백체 학회 2023 Molecular & cellular toxicology Vol.19 No.4

Background Arsenic can increase the risk of osteoporosis among the population in arsenic–endemic areas compared with the general population in non-endemic areas. And calcium overload is the related mechanisms of arsenic-induced osteoporosis However, there is a relative lack of clinical research on the treatment of arsenic-induced osteoporosis. Dantrolene and 2-APB, as Ca 2+ infl ux inhibitor, can reduce calcium overload and play an important role in the excitation–contraction coupling of skeletal muscle. Therefore, we study the eff ects of dantrolene and 2-APB on arsenic-induced osteoporosis in this study. Objective To study the eff ects of arsenic on the trabeculae of rats, and observe the eff ects of dantrolene and 2-aminoethoxydiphenyl borate (2-APB) on the trabeculae. Results Compared with the control group, some indices of micro-CT (BV/TV, Tb.Th, Tb.N, BMD, and DA) and the alkaline phosphatase (ALP) activity of bone marrow stromal cells (BMSCs) decreased, while some indices of micro-CT (Tb.Sp, Tb.Pf, and SMI), biochemical indicators (ALT, AST, ALP, and GGT), and the Ca 2+ concentration of BMSCs increased in the Sodium arsenite (NaAsO 2 ) group ( P < 0.05). Compared with the NaAsO 2 group, the indices of micro-CT and biochemical indicators improved, the Ca 2+ concentration of BMSCs decreased, and the ALP activity of BMSCs increased in the dantrolene group, 2-APB group and dantrolene + 2-APB group ( P < 0.05), especially dantrolene + 2-APB group. Conclusion NaAsO 2 can lead to osteoporosis in rats, dantrolene and 2-APB can reduce the degree of arsenic-induced osteoporosis.

Optimization of Process Conditions for Production of Angiotensin IConverting Enzyme (ACE) Inhibitory Peptides from Vital Wheat Gluten using Response Surface Methodology

Rosemond Godbless Dadzie,Haile Ma,Ernest Ekow Abano,Wenjuan Qu,Shuyun Mao 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.6

The degree of hydrolysis (DH) and angiotensinI-converting enzyme (ACE)-inhibitory activity of vitalwheat gluten (VWG) hydrolyzed using Alcalase wereinvestigated using Box-Behnken response surfacemethodology (RSM). The mean responses were fitted to asecond order polynomial to obtain regression equations. The enzyme-substrate ratio and the hydrolysis time increasedthe DH significantly (p<0.05). The substrate concentrationwas the only significant linear term leading to an increasein ACE-inhibitory activity. The optimized conditions of asubstrate concentration of 5.04%, an enzyme-substrateratio 5.94%, and a hydrolysis time 30.79 min gave a pointprediction of a 12.74% DH and 82.28% ACE-inhibitoryactivity. Analytical results from confirmatory experimentwere a 12.22%±0.5 DH and a 78.93%±1.07 ACEinhibitoryactivity. The optimized conditions of the studyprovide useful information to the functional food andbeverage industries to enhance the anti-hypertensiveactivities of peptides from VWG.