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Studies on the Evaluation Method for Small and Medium Enterprises’ EPR Project Risks
Li-Yongming 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.4
This paper explains the studies of recent years on development of EPR system and the project risk and then illustrates respectively the external risks and internal risks of EPR project based on the theory. Taking the EPR project of G company the author actually took part in as an example, the author firstly applies fuzzy evaluating method to evaluate project risks and draw a clear distinction between the primary and the secondary to achieve overall evaluation for project risk. And then the author worked out a plan for the main risks of the project and applied multiple management methods to control. And in practical implementation steps, the author implemented management method in every segment and did supervising and controlling to gain the lowest negative influence resulting from risks. Lastly, the author concluded the effects of risks management, learned lessons and proposed perspectives.
Asymptotic normality of wavelet estimator for strong mixing errors
Li Yongming,Guo jianhua 한국통계학회 2009 Journal of the Korean Statistical Society Vol.38 No.4
In this paper, we consider a non-parametric fixed design regression model based on strong mixing sequences. We use a new tool presented in the literature recently for the weighted sum estimate, and establish the asymptotic normality of a wavelet estimator for an unknown regression function.
Peng Xu,Yongming Li,Shaocheng Tong 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.7
This paper investigates the problem of fuzzy adaptive finite-time fault tolerant control (FTC) for a classof multi-input and multi-output (MIMO) nonlinear systems with actuator failure. In control design, the fuzzylogic systems (FLSs) are adopted to identify the unknown nonlinear functions and a state observer is constructedto estimate the unmeasurable states. By combining dynamic surface control (DSC) technique with backsteppingdesign, a novel finite-time fuzzy adaptive FTC strategy is proposed based on fault-tolerant control technique toovercomes the “explosion of complexity” problem. The presented control method demonstrates that all signals ofthe closed-loop system are semi-global practical finite-time stability (SGPFS), and the tracking errors converge to asmall neighborhood of zero in a finite time. Finally, a numerical example is provided to illustrate the effectivenessof the presented control method.
One-step synthesis of mesoporous sulfated zirconia nanoparticles with anionic template
Hongping Pu,Yongming Luo,Liuyi Zhang,Dongquan Du,Caiyun Han,Hongyin Li,Jiangyan Li 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.10
Mesoporous sulfated zirconia nanoparticles (MSZNP) with high surface area have been synthesized by using sodium dodecyl sulfate (C12H25OSO3Na, SDS), both as a template and a sulfating agent via one-step route. On the basis of FT-IR, EDS together with NH3-TPD analyses, the SO42− anion, originated from the hydrophilic head of SDS, can be incorporated into ZrO2 to form MSZNP with super-acidity. The phase transition of ZrO2 from tetragonal to monoclinic phase was effectively inhibited by the presence of SO42−, and the formation mechanism was illustrated in detail. MSZNP(550) achieved far higher activity than CSZ(550) in transesterification of soybean oil with methanol due to the synergistic effect of strong acidity, high BET surface area and the formation of mesostructure.
Zhongliang Sun,Yongming Zhang,Xiangyun Deng,Jianbao Li,Chunrong Xiong 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.1
Silicalite-1 and titanium containing silicalite-1 (TS-1) hollow fibers were fabricated with polyethylene imine (PEI) fibers as substrates. The acid treated PEI fibers were positively charged and can be effectively coated with silicalite-1 or TS-1 nanocrystals from their colloidal solution. The adsorbed silicalite-1 or TS-1 nanocrystals grew up and became more compact upon two days of vapor phase Ostwald ripening in autoclave. Silicalite-1 and TS-1 hollow fibers were obtained after calcination at 400 8C in air. The shell thickness of the hollow fibers is 1 mm. Hydroxylation of phenol with H2O2 was investigated over TS-1based catalysts in order to compare influences of nanocrystals composed macrostructure and Al2O3binder on the catalytic activities.
GaN nanorods gas sensor for highly sensitive n-butanol detection at room temperature
Shuai Han,Yongming Fu,Donghui Li,Dan Han,Qinjun Sun 대한금속·재료학회 2023 ELECTRONIC MATERIALS LETTERS Vol.19 No.3
Safe and effi cient detection of hazardous n-butanol gas is very great signifi cance to the health of workers and researchers inchemical environments. In this work, we successfully developed a GaN gas sensor by a simple solvothermal method and alow-temperature nitridation process. Material characterization results show that one-dimensional nanorods structures wereobtained and the products presented a superior growth orientation along with (101) plane. The gas sensing test results showthat the sensor exhibits excellent responsivity, repeatability, and selectivity to n-butanol at room temperature. The responseand recovery time of the sensor to 200 ppm n-butanol gas was 45 s/34 s. Gas adsorption model and electron depletion layertheory were established to understand the n-butanol sensing mechanism. This work provides the possibility for its realapplication in n-butanol detection with safe and effi cient at room temperature.
Ruitong Wu,Kunting Yu,Yongming Li,Wei Liu 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.12
In this paper, an adaptive fuzzy event-triggered control scheme is investigated for a class of nonlinear switched systems with dead zone nonlinearity. Fuzzy logic systems are employed in identifying unknown nonlinear functions. Then, the dynamic surface control (DSC) method is exploited to overcome the problem of “explosion of complexity” in traditional adaptive backstepping recursive design process. Based on the Lyapunov stability theory and the backstepping technique with the event-triggered mechanism, the proposed control method proves that all the closed-loop system signals are bounded, and the tracking error converges to a small neighborhood of the origin under the arbitrary switching. Simultaneously, this control method proves that Zeno behavior can be eliminated. The simulation results also illustrate the validity of the developed control method and theorem.
Fixed-time Fuzzy Adaptive Decentralized Control for High-order Nonlinear Large-scale Systems
Bo Kang,Zhiyao Ma,Yongming Li,Wei Zhang 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.12
This paper studies a fuzzy adaptive fixed-time tracking control issue for nonlinear high-order largescale systems. Fuzzy logic systems (FLSs) are utilized to identify unknown nonlinearities. Through using adaptive backstepping and adding a power integrator technique, the fixed-time decentralized control method is presented. It is proved that the tracking errors converge to a small neighborhood of a fixed time. A simulation example is presented to confirm the validity of the developed control method.
Tiechao Wang,Xuhang Zhang,Yongming Li 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.8
The adaptive interval type-2 (IT2) fuzzy output feedback control problem is studied for a single-phase photovoltaic grid-connected power system. The equivalent resistors of the inductors in the system are unknown and the part states are not available. Interval type-2 fuzzy logic systems (IT2FLSs) are utilized to approximate the uncertain nonlinear dynamics, and an IT2 fuzzy state observer is designed to estimate the unavailable states. By introducing a command filter method and using a backstepping control design technique, an IT2 fuzzy output feedback control scheme is investigated, in which the constraint conditions of pulse width modulation are ensured via mean-value theorem. It is proved that all the variables of the closed-loop photovoltaic system are uniformly ultimately bounded. The simulation and comparison results demonstrate the validity of the proposed control scheme.
Fatigue evaluation and CFRP strengthening of diaphragm cutouts in orthotropic steel decks
Lu Ke,Chuanxi Li,Jun He,Yongjun Lu,Yang Jiao,Yongming Liu 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.39 No.4
The cracking at the transverse diaphragm cutout is one of the most severe fatigue failures threatening orthotropic steel decks (OSDs), whose mechanisms and crack treatment techniques have not been fully studied. In this paper, full-scale experiments were first performed to investigate the fatigue performance of polished cutouts involving the effect of an artificial geometrical defect. Following this, comparative experimental testing for defective cutouts strengthened with carbon fiber-reinforced polymer (CFRP) was carried out. Numerical finite element analysis was also performed to verify and explain the experimental observations. Results show that the combinative effect of the wheel load and thermal residual stress constitutes the external driving force for the fatigue cracking of the cutout. Initial geometrical defects are confirmed as a critical factor affecting the fatigue cracking. The principal stress 6 mm away from the free edge of the cutout can be adopted as the nominal stress of the cutout during fatigue evaluation, and the fatigue resistance of polished cutouts is higher than Grade A in AASHTO specification. The bonded CFRP system is highly effective in extending the fatigue life of the defective cutouts. The present study provides some new insights into the fatigue evaluation and repair of OSDs.