Fault Recoverability Analysis of Nonlinear Systems: A Piecewise Affine System Approach

Wenjing Ren,Hao Yang,Bin Jiang 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.2

The recoverability reflects the capability of the system to tolerate the worst faults over a prescribed setunder admissible energy constrains. In this paper, a piecewise affine (PWA) controller is designed for a PWAapproximation of the nonlinear dynamics, which can stabilize the original nonlinear system under some conditions. By analyzing the upper bound of the piecewise linear quadratic control performance of the PWA system, a novelfault recoverability evaluation scheme is further proposed for the nonlinear system with respect to the given limitof admissible control performance. A longitudinal flight control example is taken to show the effectiveness of theproposed method.

Joint Opportunistic Spectrum Access and Optimal Power Allocation Strategies for Full Duplex Single Secondary User MIMO Cognitive Radio Network

( Wenjing Yue ),( Yapeng Ren ),( Zhen Yang ),( Zhi Chen ),( Qingmin Meng ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.10

This paper introduces a full duplex single secondary user multiple-input multiple-output (FD-SSU-MIMO) cognitive radio network, where secondary user (SU) opportunistically accesses the authorized spectrum unoccupied by primary user (PU) and transmits data based on FD-MIMO mode. Then we study the network achievable average sum-rate maximization problem under sum transmit power budget constraint at SU communication nodes. In order to solve the trade-off problem between SU`s sensing time and data transmission time based on opportunistic spectrum access (OSA) and the power allocation problem based on FD-MIMO transmit mode, we propose a simple trisection algorithm to obtain the optimal sensing time and apply an alternating optimization (AO) algorithm to tackle the FD-MIMO based network achievable sum-rate maximization problem. Simulation results show that our proposed sensing time optimization and AO-based optimal power allocation strategies obtain a higher achievable average sum-rate than sequential convex approximations for matrix-variable programming (SCAMP)-based power allocation for the FD transmission mode, as well as equal power allocation for the half duplex (HD) transmission mode.

Mangiferin loaded magnetic PCEC microspheres: preparation, characterization and antitumor activity studies in vitro

WenJing Xiao,Jun Hou,Jie Ma,BoTao Yu,JianDong Ren,WeiHua Jin,Juan Wu,DeZhi Zheng,KaiHua Fan 대한약학회 2021 Archives of Pharmacal Research Vol.44 No.8

Mangiferin is a promising effective chemopreventiveagent against various tumors. However, itsclinical use is limited by poor water solubility and lowbioavailability. In this article, mangiferin loaded magneticPCEC microspheres (MG-MS) were designed, characterizedand the antitumor activity of MG-MS was evaluatedin vitro. The magnetic nanoparticles (MNP) were synthesizedvia the high-temperature reaction of ironacetylacetonate in phenyl ether in the presence of oleic acidand oleylamine. Poly (ε-caprolactone)-poly (ethyleneglycol)-poly (ε-caprolactone) (PCL-PEG-PCL, PCEC)copolymers were formed by ring-opening copolymerizationof ε-CL initiated by PEG-diol using Sn(Oct)2 as acatalyst and MG-MS were prepared by solvent diffusionmethod. MNP, PCEC copolymer, and MG-MS werecharacterized by GPC, TEM, XRD, FT-IR, 1H-NMP andMalvern Laser Particle Sizer. Meanwhile, the antiproliferativeactivity in vitro and in vitro release behavior of thismicrospheres were studied in detail. The results indicatethat the obtained magnetic microspheres might have greatpotential as an effective carrier for mangiferin used incancer chemotherapy.

Helicobacter pylori-Induced Progranulin Promotes the Progression of the Gastric Epithelial Cell Cycle by Regulating CDK4

Ren Zongjiao,Li Jiayi,Du Xianhong,Shi Wenjing,Guan Fulai,Wang Xiaochen,Wang Linjing,Wang Hongyan 한국미생물·생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.7

Helicobacter pylori, a group 1 carcinogen, colonizes the stomach and affects the development of stomach diseases. Progranulin (PGRN) is an autocrine growth factor that regulates multiple cellular processes and plays a tumorigenic role in many tissues. Nevertheless, the mechanism of action of PGRN in gastric cancer caused by H. pylori infection remains unclear. Here, we investigated the role of PGRN in cell cycle progression and the cell proliferation induced by H. pylori infection. We found that the increased PGRN was positively associated with CDK4 expression in gastric cancer tissue. PGRN was upregulated by H. pylori infection, thereby promoting cell proliferation, and that enhanced level of proliferation was reduced by PGRN inhibitor. CDK4, a target gene of PGRN, is a cyclin-dependent kinase that binds to cyclin D to promote cell cycle progression, which was upregulated by H. pylori infection. We also showed that knockdown of CDK4 reduced the higher cell cycle progression caused by upregulated PGRN. Moreover, when the PI3K/Akt signaling pathway (which is promoted by PGRN) was blocked, the upregulation of CDK4 mediated by PGRN was reduced. These results reveal the potential mechanism by which PGRN plays a major role through CDK4 in the pathological mechanism of H. pylori infection.

Strategy to increase distortional rigidity of crane box girder: Staggered truss diaphragm

Yangzhi Ren,Wenjing Guo,Xuechun Liu,Bin Wang,Piyong Yu,Xiaowen Ji 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.86 No.4

This paper proposes a novel method for increasing the distortional frame rigidity of off-rail box girder bridges for cranes by reinforcing the diaphragm with staggered truss. The study starts by using the Matrix Displacement Method to determine the shear angle of the staggered truss diaphragm under two assumptions: hinge joint and rigid joint. To obtain closedform solutions for the transversal and longitudinal deformations and warping stress of the crane girder, the study employs the Initial Parameter Method and considers the compatibility of shear deformation at joints between the diaphragms and the girder. The theoretical solutions are validated through finite element analysis, which also confirms that the hinge-joint assumption accurately represents the shear angle of the staggered truss diaphragm in girder distortion. Additionally, the study conducts extensive parameter analyses to examine the impact of staggered truss dimensions on distortional stress and deformation. Furthermore, the study compares the distortional warping stresses of crane girders reinforced with staggered truss diaphragms and those reinforced with perforated ones, emphasizing the importance of incorporating stagger truss in diaphragms. Overall, this paper provides a thorough evaluation of the proposed approach's effectiveness in enhancing the distortional frame rigidity of off-rail box girder bridges for cranes. The findings offer valuable insights into the design and reinforcement of diaphragms using staggered truss to enhance the structural performance of crane girders.

HACP2 : The Pre-processing Software Tool for the Hybrid Atomistic-Continuum Coupling Simulation

Qian Wang,Wenjing Yang,Fu Li,Xiaoguang Ren,Yuhua Tang 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.1

Fluid simulation is an important application of High Performance Computing. The hybrid atomistic-continuum coupling fluid simulation can effectively handle the contradictory of the reduction of the simulation scale and the increase of the computation load when trying to improve the accuracy. The pre-processing procedure of the coupling simulation is quite important in the whole simulation process and requires the support of an efficient, user-friendly interface. Under the demand of efficient coupling fluid simulation, in this paper we design and implement a visualized pre-processing framework HACP2 based on SALOME, for the unified molecular dynamic-computational fluid dynamics modeling and apply it into the coupling simulation process. The experimental verification indicates that our HACP2 framework can offer efficient, easy-to-use pre-processing for the hybrid atomistic-continuum coupling simulation, and effectively improve the efficiency of the coupling simulation.

Simulations of water vaporization in novel internal-intensified spouted beds: Multiphase-flow, heat and mass transfer

Xinxin Che,Rong Guo,Feng Wu,Haibo Ren,Wenjing Zhou 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.116 No.-

Novel internal-intensified spouted beds (SBs) with swirl-nozzle anticlockwise-axial-swirler (SNAAS) andswirl-nozzle clockwise-axial-swirler (SNCAS) were proposed to improve the shortcomings of conventionalSBs. The water vaporization in novel internal-intensified, conventional and swirl-nozzle SBs wassimulated and the multiphase flow behavior and interphase heat and mass transfer in process were analyzed. Simulation results show the co-swirling action of novel combined internal-intensified makes gasdrive particles move helically upward around the axial-swirler. Therefore, compared with conventionaland swirler-nozzle SBs, the radial slip velocity of gas–solid and gas–liquid in two novel SBs are larger,and the contact between gas–liquid-solid phases is more sufficient. The gas–liquid-solid three-phasetemperature, water vaporization rate, and gas moisture content of two novel internal-intensified allreached the highest, indicating that novel combined internal-intensified structures are beneficial to promotingthe interphase heat and mass transfer during the water vaporization process. The mass transferenhancement factors of SNAAS and SNCAS structures are 1.91 and 1.36 times that of conventional SB,respectively.

The Associations of Family Functioning, General Well-Being, and Exercise with Mental Health among End-Stage Renal Disease Patients

Qi Wang,Hongjian Liu,Zheng Ren,Wenjing Xiong,Minfu He,Nan Li,Xinwen Fan,Xia Guo,Xiangrong Li,Hong Shi,Shuang Zha,Xiumin Zhang 대한신경정신의학회 2020 PSYCHIATRY INVESTIGATION Vol.17 No.4

Objective This study aims to explore the relationships of family functioning, general well-being, and exercise with psychological distress. Furthermore, we investigated the special roles of general well-being and exercise on the association between family functioning and psychological distress. Methods Of 769 end-stage renal disease (ESRD) patients participated in the cross-sectional study which consisted of the 12-item General Health Questionnaire (GHQ-12), the Family APGAR Scales, and the General Well-Being Schedule. The collected data were analyzed using multiple linear regression analysis and path analysis. Results The prevalence of psychological distress was 72.3%. Family functioning, general well-being and exercise were associated factors of psychological distress (p<0.05). The indirect effect of family functioning on psychological distress was partially mediated by general well-being (Effect=-0.08, 95% CI=-0.11, -0.04). In addition, the effect of family functioning on general well-being was moderated by exercise (Index=-0.092, SE=0.033, 95% CI=-0.159, -0.029). Conclusion The prevalence of psychological distress among ESRD patients was high. Family functioning, general well-being and exercise were associated with psychological distress. Family functioning could affect psychological distress partially by affecting general wellbeing. Furthermore, exercise had a significant moderating effect on the relationship between family functioning and general well-being.