Search scope:
排序: Display mode:
Secrecy outage performance for wireless-powered relaying systems with nonlinear energy harvesters Article
继亮 张,高峰 潘,宜原 解
Frontiers of Information Technology & Electronic Engineering 2017, Volume 18, Issue 2, Pages 246-252 doi: 10.1631/FITEE.1601352
Nonlinear Science and Its Medical Applications
Tu Chengyuan,Zeng Yanjun
Strategic Study of CAE 2003, Volume 5, Issue 8, Pages 45-49
The fractal-dimension theory and the Shannom entropy theory of nonlinear science are briefly described, and the methods to apply them to analyze AF's information are developed. The grid-dimension values and the Shannom entropy values of P-wave and those of f-wave are computed. The comparison of the remarkable difference between values of these two kinds of waves is given so as to easily determine whether AF happens or not.
Keywords: complicated and large system nonlinear fractal theory fractal-dimension Shannom entropy AF(atrial fibrillation)
Pulse Transiently Chaotic Neural Network for Nonlinear Constrained Optimization
Li Ying,Cao Hongzhao,Hu Yunchang,Shang Xiuming
Strategic Study of CAE 2004, Volume 6, Issue 5, Pages 45-48
Pulse Transiently Chaotic Neural Network (PTCNN) can find almost all optima including the part optima and the global with its abundance dynamical characteristic, when is used in nonlinear non-constrained optimization. The optimization problem is first unconstrained by virtue of non-differentiable exact penalty function, and is further solved by PTCNN. It is showed by an example that this method is efficient.
Keywords: PTCNN penalty function nonlinear constrained optimization
The nonlinear singularity phenomenon of low frequency oscillation in power system
Ma Jinglan,Wang Wei,Wan Jingsheng,Zhang Yongli
Strategic Study of CAE 2009, Volume 11, Issue 8, Pages 93-96
LFO (Low Frequency Oscillation) is a main aspect that affects power system stability. In this paper, the inherent reason that causes LFO is discussed.With Hopf bifurcation theory, it is analyzed that the nonlinear singularity phenomenon happens close to the critical points in a single-infinite power system of four-rank model. The study indicates that because of the Hopf bifurcation, singularity phenomenon in the power system happens close to the critical points, which affects the steady bound.
Keywords: LFO bifurcation theory nonlinear singularity
Event-triggered dynamic output-feedback control for a class of Lipschitz nonlinear systems Research Article
Zhiqian LIU, Xuyang LOU, Jiajia JIA
Frontiers of Information Technology & Electronic Engineering 2022, Volume 23, Issue 11, Pages 1684-1699 doi: 10.1631/FITEE.2100552
This paper investigates the problem of for a class of s. First, a continuous-time controller is constructed and sufficient conditions for stability of the nonlinear systems are presented. Then, a novel event-triggered mechanism is proposed for the s in which new event-triggered conditions are introduced. Consequently, a closed-loop hybrid system is obtained using the strategy. Sufficient conditions for stability of the closed-loop system are established in the framework of hybrid systems. In addition, an upper bound of a minimum inter-event interval is provided to avoid the Zeno phenomenon. Finally, numerical examples of a neural network system and a genetic regulatory network system are provided to verify the theoretical results and to show the superiority of the proposed method.
Keywords: Lipschitz nonlinear system Dynamic output-feedback control Event-triggered control Global asymptotic stability
Analysis of Plates and Shells and Its Application
Liu Renhuai
Strategic Study of CAE 2000, Volume 2, Issue 11, Pages 60-67
Plates and shells are excellent structural elements. Analys of plates and shells is an important branch in modern solid mechanics. It plays a guiding role in many fields because of its wide application to almost all the engineering design, especially to astronautics, aeronautics, marine, machinery, petrochemical industry, architecture, water conservancy, power, instruments and transportation. Analysis of plates and shells originates from the 18th century with the development of industry. In the 20th century , the rocketing development of industry greatly stimulated the development and application of this subject. Now, the classical linear theory of thin plates and shells has matured and already been playing a decisive role in many engineering designs. However, there are still many problems left to be solved in the fields on nonlinear theory of thin plates and shells, and linear theory of thick plates and shells. Based on introduction of the history of development of this subject, this paper gives a brief account of the exploration the author did in nearly forty years, which has been well applied to engineering problems, in the areas of nonlinear bending, stability and vibration of thin plates and shells such as corrugated plates and shells, one-layer plates and shells, bimetallic shallow shells of revolution, latticed shallow shells, sandwich plates and shells, and laminated composite plates and shells. The paper also gives an introduction of the author's work on the linear bending of both thick and thin plates and shells.
Keywords: thin plates and shells thick plates and shells nonlinear problem linear problem bending stability vibration
Nonlinear Model-Based Process Operation under Uncertainty Using Exact Parametric Programming
Vassilis M. Charitopoulos,Lazaros G. Papageorgiou,Vivek Dua
Engineering 2017, Volume 3, Issue 2, Pages 202-213 doi: 10.1016/J.ENG.2017.02.008
In the present work, two new, (multi-)parametric programming (mp-P)-inspired algorithms for the solution of mixed-integer nonlinear programming (MINLP) problems are developed, with their main focus being on process synthesis problems. The algorithms are developed for the special case in which the nonlinearities arise because of logarithmic terms, with the first one being developed for the deterministic case, and the second for the parametric case (p-MINLP). The key idea is to formulate and solve the square system of the first-order Karush-Kuhn-Tucker (KKT) conditions in an analytical way, by treating the binary variables and/or uncertain parameters as symbolic parameters. To this effect, symbolic manipulation and solution techniques are employed. In order to demonstrate the applicability and validity of the proposed algorithms, two process synthesis case studies are examined. The corresponding solutions are then validated using state-of-the-art numerical MINLP solvers. For p-MINLP, the solution is given by an optimal solution as an explicit function of the uncertain parameters.
Keywords: Parametric programming Uncertainty Process synthesis Mixed-integer nonlinear programming Symbolic manipulation
Causality fields in nonlinear causal effect analysis Correspondence
Aiguo WANG, Li LIU, Jiaoyun YANG, Lian LI,dcsliuli@cqu.edu.cn,jiaoyun@hfut.edu.cn,wangaiguo2546@163.com,llian@hfut.edu.cn
Frontiers of Information Technology & Electronic Engineering 2022, Volume 23, Issue 8, Pages 1277-1286 doi: 10.1631/FITEE.2200165
Keywords: 非线性因果效应;因果域;z-特异性因果效应;正向因果;负向因果;空因果
Research on Nonlinear Combination Forecasting Approach Based on BP-AGA
Wang Shuo,Zhang Youfu,Jin Juliang
Strategic Study of CAE 2005, Volume 7, Issue 4, Pages 83-87
A nonlinear combination forecasting model was established by using neural network and accelerating genetic algorithm (AGA) in the paper. AGA was used to optimize the network parameters as BP approach was slow with training network. Optimization results of AGA were taken as original values of BP approach, the network was trained with BP approach. Network convergence rate was increased with running BP approach and AGA alternately. Meanwhile the part least problem was improved. Examples were presented finally, as a result, the forecasting precision high in evidence.
Keywords: neural network accelerating genetic algorithm nonlinear combination forecasting forecasting precision
Nonlinear Size-dependent Study of Ultra-thin Elastic Film With Surface Effect
Huang Dianwu,Li Yuanjun,Li Kai
Strategic Study of CAE 2006, Volume 8, Issue 4, Pages 54-59
A new nano-scale plate-like model in which the influence of surface effect and the geometrically nonlinear condition are considered is introduced on the basis of Mindlin theory. By using Hamilton's principle, the governing equations are derived. The residue membrane force and bending moment, which are caused by the surface stresses, are explicitly expatiated. After analyzing the membrane force and bending moment, it can be obtained that they are dependent on the deformation of the film and are accordant to classical plate theory. The model is then applied to analyze the bending and buckling of simply supported micro- and nano-films in plane strains . Differing from the conventional plate theory, the proposed model and solutions involve the intrinsic scale and depend on the thickness of the film. Thus, it can be found that when the thickness of,the film is equal to or less than the intrinsic scale, the surface effect is strongly sensitive to the thickness of the film.
Keywords: thin elastic film geometrically nonlinear surface effect intrinsic scale size-dependence
Nonlinear restoring force identification based on measured time series
Xu Bin,He Jia
Strategic Study of CAE 2011, Volume 13, Issue 9, Pages 76-82
In this study, a general nonlinear restoring force (NRF) identification approach using structural dynamic response measurements and complete excitations is proposed at first. In this approach, the least-squares technique is employed to identify the parameters of an equivalent linear system of the nonlinear structure model based on the external excitations and the corresponding response measurements. The proposed approach is developed when the structure to be identified is incompletely excited. Both of the approaches are validated with a 4-story frame structure equipped with smart devices of magneto-rheological (MR) damper to simulate nonlinear performance. The identified NRF of the structure is compared with the test measurements. Results show that the proposed data-based approaches are capable of identifying the nonlinear restoring behavior of engineering structures and have the potential to be employed to evaluate the damage initiation and development procedure of engineering structures under dynamic loads.
Keywords: nonlinear restoring force identification MR damper least-squares techniques equivalent linear system non-parametric model
Global Optimization of Nonlinear Blend-Scheduling Problems
Pedro A. Castillo Castillo Pedro M. Castro,Vladimir Mahalec
Engineering 2017, Volume 3, Issue 2, Pages 188-201 doi: 10.1016/J.ENG.2017.02.005
The scheduling of gasoline-blending operations is an important problem in the oil refining industry. This problem not only exhibits the combinatorial nature that is intrinsic to scheduling problems, but also non-convex nonlinear behavior, due to the blending of various materials with different quality properties. In this work, a global optimization algorithm is proposed to solve a previously published continuous-time mixed-integer nonlinear scheduling model for gasoline blending. The model includes blend recipe optimization, the distribution problem, and several important operational features and constraints. The algorithm employs piecewise McCormick relaxation (PMCR) and normalized multiparametric disaggregation technique (NMDT) to compute estimates of the global optimum. These techniques partition the domain of one of the variables in a bilinear term and generate convex relaxations for each partition. By increasing the number of partitions and reducing the domain of the variables, the algorithm is able to refine the estimates of the global solution. The algorithm is compared to two commercial global solvers and two heuristic methods by solving four examples from the literature. Results show that the proposed global optimization algorithm performs on par with commercial solvers but is not as fast as heuristic approaches.
Keywords: Global optimization Nonlinear gasoline blending Continuous-time scheduling model Piecewise linear relaxations
High-gain Sliding Mode Output Tracking for Nonlinear Systems
Wang Xinhua,Chen Zengqiang,Yuan Zhuzhi
Strategic Study of CAE 2004, Volume 6, Issue 2, Pages 38-43
An observer based on external and internal dynamics is designed, making the error between observing value and factual value to zero. Moreover, a continuously high-gain sliding mode controller is presented by using a sliding mode state which can make the error between the output and reference signal converge to zero. The analysis of stability and the result of simulation indicate that the controller designed has strong robustness and rapid convergence.
Keywords: nonlinear systems external dynamics internal dynamics sliding mode control robustness
Chen Changhong,Huang Ying,Ma Lewei,Wu Minzhe,Shan Jian
Strategic Study of CAE 2007, Volume 9, Issue 11, Pages 92-95
The paper makes experiment about six T-shaped cross section column frame joints under low periodic cycle loads. The paper uses variable parameters of beam section height, the axis-pressed ratio and the volume ratio of hoop reinforcement to research cracks formation and development and the failure mechanism of the joints. The paper points out that joints'crack shape appears as reverse "K" but not the common rectangular joints' "X" shape, and the endure mechanism is inclined to the steep press-pole mechanism. At the same time, this paper makes use of a software ANSYS to develop the language APDL two times to T-shaped column joints to carry on nonlinear finite element analysis, adopts discrete cracking model smeared cracking model, and carries on the contrast analysis with experiment result. Analysis enunciates that nonlinear finite element analysis calculation results fit in aill with experiment result. The paper changes procedure parameters to cause the core area shear-press breakage, and to do further argument about the formation of the joints crack and the joints failure mechanism.
Keywords: T-shaped joints crack shape failure mechanism ANSYS nonlinear finite element
Knowledge-Based Variable Structure Decoupling Control of a Nonlinear Multivariable System
Tu Chengyuan,Zeng Yanjun
Strategic Study of CAE 2001, Volume 3, Issue 10, Pages 48-52
A knowledge-based variable-structure decoupling is developed, and be utilized to control a nonlinear multivariable system, so as to avoid the model-establishing process, especially avoid large amount of complex matrix operations required for the conventional decoupling control. Some modules in the knowledge base of this kind of control are described, and the main points of the related algorithms are introduced. Strategies described in this paper have been successively utilized to the set-point temperature control of a 3 × 3 strong coupled system —a three winding heater type standard temperature source, and an effect that the temperature stability as well as temperature homogeneity all better than 1℃ has been attained, which is impossible for the conventional control method.
Keywords: nonlinear multivariable system decoupling control knowledge based variable structure decoupling
Title Author Date Type Operation
Secrecy outage performance for wireless-powered relaying systems with nonlinear energy harvesters
继亮 张,高峰 潘,宜原 解
Journal Article
Pulse Transiently Chaotic Neural Network for Nonlinear Constrained Optimization
Li Ying,Cao Hongzhao,Hu Yunchang,Shang Xiuming
Journal Article
The nonlinear singularity phenomenon of low frequency oscillation in power system
Ma Jinglan,Wang Wei,Wan Jingsheng,Zhang Yongli
Journal Article
Event-triggered dynamic output-feedback control for a class of Lipschitz nonlinear systems
Zhiqian LIU, Xuyang LOU, Jiajia JIA
Journal Article
Nonlinear Model-Based Process Operation under Uncertainty Using Exact Parametric Programming
Vassilis M. Charitopoulos,Lazaros G. Papageorgiou,Vivek Dua
Journal Article
Causality fields in nonlinear causal effect analysis
Aiguo WANG, Li LIU, Jiaoyun YANG, Lian LI,dcsliuli@cqu.edu.cn,jiaoyun@hfut.edu.cn,wangaiguo2546@163.com,llian@hfut.edu.cn
Journal Article
Research on Nonlinear Combination Forecasting Approach Based on BP-AGA
Wang Shuo,Zhang Youfu,Jin Juliang
Journal Article
Nonlinear Size-dependent Study of Ultra-thin Elastic Film With Surface Effect
Huang Dianwu,Li Yuanjun,Li Kai
Journal Article
Nonlinear restoring force identification based on measured time series
Xu Bin,He Jia
Journal Article
Global Optimization of Nonlinear Blend-Scheduling Problems
Pedro A. Castillo Castillo Pedro M. Castro,Vladimir Mahalec
Journal Article
High-gain Sliding Mode Output Tracking for Nonlinear Systems
Wang Xinhua,Chen Zengqiang,Yuan Zhuzhi
Journal Article
Experimental Study and Nonlinear Finite Element Analysis on the T-shaped Column Frame Structure Joints
Chen Changhong,Huang Ying,Ma Lewei,Wu Minzhe,Shan Jian
Journal Article