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Two-level consensus modeling with utility and cost constraints

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Journal of Systems Engineering and Electronics 2022年第3期33卷 716-726页

作者： DIAO Weixue liu yong School of Business Jiangnan UniversityWuxi 214122China

There exist many two-level group consensus problems with different psychological behaviors of decision *** deal with these group consensus problems and reach a stable consensus,based on the principles and methods of grey system,utility theory and group consensus,we use grey utility function to describe and reflect decision makers’opinion preferences in different subgroups and different levels,and then we construct a two-level group consensus method with a moderator,and exploit it to solve the negotiation problems of the natural gas subsidy.

关键词： two-level group consensus group negotiation uti-lity function natural gas subsidy

Experimental Study of Irregular Wave Reflection by a Perforated Caisson Breakwater Under Wave Overtopping Conditions

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Journal of Ocean University of China 2022年第4期21卷 926-934页

作者： liu Xiao liu yong Shandong Provincial Key Laboratory of Ocean Engineering Ocean University of ChinaQingdao 266100China

The characteristics of irregular wave reflection by a perforated caisson breakwater under wave overtopping conditions were investigated using physical model *** effects of various parameters,especially the mean overtopping discharge that was mainly determined by the relative crest freeboard,on the reflection coefficient of perforated caisson breakwater were analyzed using experimental *** results showed that the wave overtopping occurrence had no appreciable effect on the reflection coefficient when the mean overtopping discharge was less than 0.2 m^(3)(m s)^(−1).Under the wave overtopping condition,the reflection coefficient of the perforated caisson breakwater in this study was reduced by 20%-50% compared with that of the non-perforated caisson breakwater.A predictive formula of the reflection coefficient for perforated caisson breakwaters in terms of relative water depth,relative chamber width,and porosity of the caisson front wall,was developed for practical engineering design.

关键词： perforated caisson model test reflection coefficient wave overtopping predictive formula

Improved gravitational search algorithm based on free search differential evolution

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Journal of Systems Engineering and Electronics 2013年第4期24卷 690-698页

作者： yong liu Liang Ma School of Management University of Shanghai of Science and Technology Department of Foundation Courses Teaching Yancheng Institute of Technology

This paper presents an improved gravitational search algorithm （IGSA） as a hybridization of a relatively recent evolutionary algorithm called gravitational search algorithm （GSA）, with the free search differential evolution （FSDE）. This combination incorporates FSDE into the optimization process of GSA with an attempt to avoid the premature convergence in GSA. This strategy makes full use of the exploration ability of GSA and the exploitation ability of FSDE. IGSA is tested on a suite of benchmark functions. The experimental results demonstrate the good performance of IGSA.

关键词： gravitational search algorithm (GSA) free search differential evolution (FSDE) global optimization.

DOA estimation for mixed signals with gain-phase error array

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Journal of Systems Engineering and Electronics 2017年第6期28卷 1046-1056页

作者： Jiaqi Zhen yong liu College of Electronic Engineering Heilongjiang University Harbin 150080 China

Most of the direction of arrival(DOA) estimation methods often need the exact array manifold, but in actual applications,the gain and phase of the channels are usually inconsistent, which will cause the estimation invalid. A novel direction finding approach for mixed far-field and near-field signals with gain-phase error array is provided. Based on simplifying the space spectrum function by matrix transformation, DOA of far-field signals is obtained. Consequently, errors of the array are acquired according to the orthogonality of far-field signal subspace and noise ***, DOA of near-field signals can be estimated. The method merely needs one-dimensional spectrum searching, so as to improve the computational efficiency on the premise of ensuring a certain accuracy, simulation results manifest the effectiveness of the method.

关键词： direction of arrival(DOA) gain-phase errors far-field signals near-field signals

Design and implementation of Chinese libration point missions

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Science China(Information Sciences) 2023年第9期66卷 100-114页

作者： Lei liu Weiren WU yong liu Beijing Aerospace Control Center Lunar Exploration and Space Program Center

Libration points are vital for lunar and deep space explorations because of their unique positions and dynamics. This paper first traces the development of relevant missions since ISEE-3 and then presents the details of the trajectory design and implementation of four Chinese libration point missions in the lunar exploration project: the two Sun-Earth libration point missions by CHANG’E-2 and CHANG’E-5 and the two lunar libration point missions accomplished by CHANG’E-5T1 and Queqiao. The orbit technologies for these libration point missions are also elaborated on regarding trajectory design, maneuvering, and tracking,as well as orbit determination. This paper is expected to provide a reference for future cislunar and deep space exploration.

关键词： libration point three-body problem lunar exploration cislunar space flight scheme

Control of Spiral Waves in an Excitable Medium by Applying Close Loop Feedback Scheme

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Communications in Theoretical Physics 2008年第12期50卷 1361-1364页

作者： liu yong School of Mathematical Science Yancheng Teacher＇s University Yancheng 224051 China

In this paper, a scheme of close-loop feedback is proposed to induce transition of spiral pattern in the excitable media, which is described with the modified FitzHugh-Nagumo model. The numerical simulation results confirm that the stable rotating spiral wave is removed and the whole media becomes homogeneous when appropriate intensity of feedback is used no matter whether the coupling feedback is imposed on the whole media or the sites in one line in the media.

关键词： spiral wave close loop feedback FitzHugh-Nagumo model

Relation Between the Eventual Continuity and the E-property for Markov-Feller Semigroups

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 1-16页

作者： yong liu Zi-yu liu LMAM School of Mathematical SciencePeking UniversityBeijing100871China

We investigate some relations between two kinds of semigroup regularities, namely the e-property and the eventual continuity, both of which contribute to the ergodicity for Markov processes on Polish *** precisely, we prove that for Markov-Feller semigroup in discrete time and stochastically continuous MarkovFeller semigroup in continuous time, if there exists an ergodic measure whose support has a nonempty interior,then the e-property is satisfied on the interior of the support. In particular, it implies that, restricted on the support of each ergodic measure, the e-property and the eventual continuity are equivalent for the discrete-time and the stochastically continuous continuous-time Markov-Feller semigroups.

关键词： Markov-Feller semigroup ergodicity e-property eventual continuity

Modeling effects of alloying elements and heat treatment parameters on mechanical properties of hot die steel with back-propagation artificial neural network

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Journal of Iron and Steel Research International 2017年第12期24卷 1254-1260页

作者： yong liu Jing-chuan Zhu yong Cao School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001HeilongjiangChina National Key Laboratory for Metal Precision Hot Processing of Metals Harbin 150001HeilongjiangChina

Materials data deep-excavation is very important in materials genome *** order to carry out materials data deep-excavation in hot die steels and obtain the relationships among alloying elements,heat treatment parameters and materials properties,a 11×12×12×4 back-propagation（BP）artificial neural network（ANN）was set *** element contents,quenching and tempering temperatures were selected as input;hardness,tensile and yield strength were set as output *** ANN shows a high fitting *** effects of alloying elements and heat treatment parameters on the properties of hot die steel were studied using this *** results indicate that high temperature hardness increases with increasing alloying element content of C,Si,Mo,W,Ni,V and Cr to a maximum value and decreases with further increase in alloying element *** ANN also predicts that the high temperature hardness will decrease with increasing quenching temperature,and possess an optimal value with increasing tempering *** model provides a new tool for novel hot die steel design.

关键词： Back-propagation artificial neural network Hot die steel Alloying element Heat treatment

Thermal Phase in Bubbling Geometries

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Communications in Theoretical Physics 2008年第7期50卷 133-138页

作者： liu Chang-yong Institute of Theoretical Physics the Chinese Academy of Sciences Beijing 100080 China

We use matrix model to study thermal phase in bubbling half-BPS type liB geometries with SO（4） × SO（4） symmetry. Near the horizon limit, we find that thermal vacua of bubbling geometries have disjoint parts, and each part is one kind of phase of the thermal system. We connect the thermal dynamics of bubbling geometries with one-dimensional fermions thermal system. Finally, we try to give a new possible way to resolve information loss puzzle.

关键词： AdS/CFT matrix model black hole