Resilient Filtering for Delayed Markov Jump Neural Networks via Event-triggered Strategy

Weifeng Xia,Yongmin Li,Zuxin Li,Shuxin Du,Bo Li,Wenbin Chen 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.10

This paper deals with the event triggered filtering problem for a class of delayed discrete-time Markov jump neural networks, where a resilient filter with parameter uncertainties is adopted. The aim of this paper is to design a suitable filter which ensures that the filtering error system is stochastically stable and satisfies a prescribed mixed passivity and H∞ performance. Sufficient conditions for solvability of such a problem are developed. Basedon the obtained conditions, an explicit expression of the desired resilient filter is proposed. Finally, an example is presented to show the usefulness of the proposed scheme.

Bolted end plate connections for steel reinforced concrete composite structures

Li, Xian,Wu, Yuntian,Mao, Weifeng,Xiao, Yan,Anderson, J.C.,Guo, Yurong Techno-Press 2006 Structural Engineering and Mechanics, An Int'l Jou Vol.24 No.3

In order to improve the constructability and meanwhile ensure excellent seismic behavior, several innovative composite connection details were conceived and studied by the authors. This paper reports experimental results and observations on seismic behavior of steel beam bolted to reinforced concrete column connections (bolted RCS or BRCS). The proposed composite connection details involve post tensioning the end plates of the steel beams to the reinforced concrete or precast concrete columns using high-strength steel rods. A rational design procedure was proposed to assure a ductile behavior of the composite structure. Strut-and-tie model analysis indicates that a bolted composite connection has a favorable stress transfer mechanism. The excellent capacity and behavior were then validated through five full-scale beam to column connection model tests.

An Efficient Identity-Based Deniable Authenticated Encryption Scheme

( Weifeng Wu ),( Fagen Li ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.5

Deniable authentication protocol allows a sender to deny his/her involvement after the protocol run and a receiver can identify the true source of a given message. Meanwhile, the receiver has no ability to convince any third party of the fact that the message was sent by the specific sender. However, most of the proposed protocols didn`t achieve confidentiality of the transmitted message. But, in some special application scenarios such as e-mail system, electronic voting and Internet negotiations, not only the property of deniable authentication but also message confidentiality are needed. To settle this problem, in this paper, we present a non-interactive identity-based deniable authenticated encryption (IBDAE) scheme using pairings. We give the security model and formal proof of the presented IBDAE scheme in the random oracle model under bilinear Diffie-Hellman (BDH) assumption.

Synthesis of graphene quantum dots from organic dye for the biosensor application

Li Qiuyan,Fu Jinrun,Chen Weifeng,Zhang Fatao,Cao Jie,Liu Xiang 한국탄소학회 2023 Carbon Letters Vol.33 No.4

How to effectively deal with the polluted water by the pollutant of organic dyes is the world problem. It is of great significance if the organic dyes in the polluted water can be directly turned into the useful materials through a facile approach. Herein, the water which contains the common organic dye, Reactive red 2 (RR2), has been chosen to be the model to synthesize graphene quantum dots (GQDs) by a facile route. The comprehensive characterizations, including TEM (HRTEM), XPS, Raman, PL and UV–Vis. spectra, have been performed to confirm the structures and explore the properties of the synthesized GQDs. Meanwhile, the excellent PL properties and low biotoxicity of the GQDs confer them with the potential applications in the biological fields. When the GQDs are excited by the wavelength of 360 nm, the maximum emission is achieved at 428 nm. It is well demonstrated that the synthesized GQDs are able to detect the Al3+ which causes multiple diseases, such as Parkinson, Alzheimer, kidney disease, and even cancer. The detection range is from 90 to 800 μM, which is different from the reported kinds of the literature. Therefore, this work not only provides an economical and environmental route on solving the universal problem from organic dyes, but also facilitates to advancing the synthesis and application of GQDs.

Cytosolic escape of mitochondrial DNA triggers cGAS-STING-NLRP3 axis-dependent nucleus pulposus cell pyroptosis

Zhang Weifeng,Li Gaocai,Luo Rongjin,Lei Jie,Song Yu,Wang Bingjin,Ma Liang,Liao Zhiwei,Ke Wencan,Liu Hui,Hua Wenbin,Zhao Kangcheng,Feng Xiaobo,Wu Xinghuo,Zhang Yukun,Wang Kun,Yang Cao 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Low back pain (LBP) is a major musculoskeletal disorder and the socioeconomic problem with a high prevalence that mainly involves intervertebral disc (IVD) degeneration, characterized by progressive nucleus pulposus (NP) cell death and the development of an inflammatory microenvironment in NP tissue. Excessively accumulated cytosolic DNA acts as a damage-associated molecular pattern (DAMP) that is monitored by the cGAS-STING axis to trigger the immune response in many degenerative diseases. NLRP3 inflammasome-dependent pyroptosis is a type of inflammatory programmed death that promotes a chronic inflammatory response and tissue degeneration. However, the relationship between the cGAS-STING axis and NLRP3 inflammasome-induced pyroptosis in the pathogenesis of IVD degeneration remains unclear. Here, we used magnetic resonance imaging (MRI) and histopathology to demonstrate that cGAS, STING, and NLRP3 are associated with the degree of IVD degeneration. Oxidative stress induced cGAS-STING axis activation and NLRP3 inflammasome-mediated pyroptosis in a STING-dependent manner in human NP cells. Interestingly, the canonical morphological and functional characteristics of mitochondrial permeability transition pore (mPTP) opening with the cytosolic escape of mitochondrial DNA (mtDNA) were observed in human NP cells under oxidative stress. Furthermore, the administration of a specific pharmacological inhibitor of mPTP and self-mtDNA cytosolic leakage effectively reduced NLRP3 inflammasome-mediated pyroptotic NP cell death and microenvironmental inflammation in vitro and degenerative progression in a rat disc needle puncture model. Collectively, these data highlight the critical roles of the cGAS-STING-NLRP3 axis and pyroptosis in the progression of IVD degeneration and provide promising therapeutic approaches for discogenic LBP.

The Band Offset at CdS/Cu2ZnSnS4 Heterojunction Interface

Ji Li,Qingyang Du,Weifeng Liu,Guoshun Jiang,Xuefei Feng,Wenhua Zhang,Junfa Zhu,Changfei Zhu 대한금속·재료학회 2012 ELECTRONIC MATERIALS LETTERS Vol.8 No.4

The band offset at the CdS/Cu2ZnSnS4 heterojunction interface is studied by measuring the valence band spectra using synchrotron radiation photoemission spectroscopy. The Cu2ZnSnS4 thin films are prepared by the sulfurization of electrodeposited Cu-Zn-Sn precursors. A CdS overlayer is sequentially grown on the Cu2ZnSnS4 thin films from a chemical bath deposition process. Valence band spectra were obtained before and after each period of growth to study the electronic structure at the heterojunction interface. The valence band offset was determined to be 0.96 eV, and the conduction band offset was determined to be .0.06 eV. This means that the CdS/Cu2ZnSnS4 hetrojunction has a ‘type II’ band alignment which will cause largescale recombination at the interfaces and will not be suitable for solar cells fabrication.

Fast transient response based on digital single‑cycle charge regulation (SCCR) control

Lingyun Li,Shen Xu,Limin Yu,Weifeng Sun 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.9

The Buck converter is a commonly used voltage regulator (VR) structure that supplies power to the load devices and responds to load transients. In most of the applications, the VR is controlled by voltage or current mode control, and some nonlinear approaches are used to improve the transient response which brings more complexities to the closed loop design. To achieve a fast transient response without over-regulation under a load step transient, this paper proposes a digital single-cycle regulation (SCCR) controller, which comprised a fast path, a slow path, and a neutralization path. Unlike the conventional PID control, the neutralization path of the SCCR controller is used to offset the excessive energy change in the first cycle after a load step occurs, which makes the inductor current reach its new static condition in a shorter period of time. The mathematical model of the SCCR control is established in this paper and a scanning algorithm is proposed for the design of the compensator parameters. Experimental results are presented to verify the improvement of the transient response when compared to the conventional and nonlinear PID control, the recovery time is decreased by 64.3% and 43% for load step-up and step-down when compared with nonlinear PID control.

Biodegradable Magnesium Alloy Stents as a Treatment for Vein Graft Restenosis

Yugang Li,Lei Wang,Shanshan Chen,Dan Yu,Weifeng Sun,Shijie Xin 연세대학교의과대학 2019 Yonsei medical journal Vol.60 No.5

Purpose: To explore the effects of biodegradable magnesium alloy stents (BMAS) on remodeling of vein graft (VG) anastomoticrestenosis. Materials and Methods: To establish a VG restenosis model, seventy two New Zealand rabbits were randomly divided into threegroups according to whether a stent was implanted in the graft vein or not. BMASs and 316L stainless steel stents were implantedin BMAS and 316L groups, respectively, while no stent was implanted in the no-treatment control group (NC group). Loss of lumendiameter in the graft vein was measured in all three groups. Upon harvesting VG segments to evaluate intimal proliferationand re-endothelization, the degradation and biological safety of the stents were observed to explore the effects of BMAS on VGremodeling. Results: Model establishment and stent implantation were successful. The BMAS reduced lumen loss, compared with the controlgroup (0.05±0.34 mm vs. 0.90±0.39 mm, p=0.001), in the early stage. The neointimal area was smaller in the BMAS group than the316L group after 4 months (4.96±0.66 mm2 vs. 6.80±0.69 mm2, p=0.017). Re-endothelialization in the BMAS group was better thanthat in the 316L group (p=0.001). Within 4 months, the BMAS had degraded, and the magnesium was converted to phosphorusand calcium. The support force of the BMAS began to reduce at 2–3 months after implantation, without significant toxic effects. Conclusion: BMAS promotes positive remodeling of VG anastomosis and has advantages over the conventional 316L stents in thetreatment of venous diseases.

A New Parameter Estimation Method for a Zipf-like Distribution for Geospatial Data Access

Rui Li,Weifeng WU,Hao Wang,Huayi Wu 한국전자통신연구원 2014 ETRI Journal Vol.36 No.1

Many reports have shown that the access pattern forgeospatial tiles follows Zipf’s law and that its parameter αrepresents the access characteristics. However, visits togeospatial tiles have temporal and spatial popularities, andthe α-value changes as they change. We construct amathematical model to simulate the user’s access behaviorby studying the attributes of frequently visited tile objectsto determine parameter estimation algorithms. Becausethe least squares (LS) method in common use cannotobtain an exact α-value and does not provide a suitable fitto data for frequently visited tiles, we present a newapproach, which uses a moment method of estimation toobtain the value of α when α is close to 1. When α isfurther away from 1, the method uses the associated cachehit ratio for tile access and uses an LS method based on acritical cache size to estimate the value of α. The decreasein the estimation error is presented and discussed in thesection on experiment results. This new method, whichprovides a more accurate estimate of α than earliermethods, promises more effective prediction of requestsfor frequently accessed tiles for better caching and loadbalancing.

Collaborative Optimization Design of Event-based Asynchronous Filter for Discrete-time T-S Fuzzy Markov Jump Systems

Huiying Chen,Weifeng Xia,Zheng-Guang Wu,Zuxin Li 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.3

This article is primarily concerned with the collaborative optimization design issue of the asynchronousfilter and the event-based trigger for discrete-time nonlinear Markov jump systems modeled by the Takagi-Sugenofuzzy model. In the network environment, an event-based trigger is introduced to reduce communication consumption while the hidden Markov model approach is utilized to express the asynchronous phenomenon between thefilter and the plant. Based on this framework, using the parameter-dependent Lyapunov function and matrix inequality techniques, the H∞ and L2 −L∞ asynchronous filter design schemes are developed such that the resultingfiltering error dynamic system can be randomly mean square stable and satisfy a preset noise attenuation performance. Furthermore, an iterative optimization algorithm is presented to collaboratively solve the optimal parametersof the filter and the trigger. At last, a tunnel-diode circuit is employed to verify the validity of our design schemes.