Digraph-based causal models have been widely used to model the cause and effect behavior of process systems. Signed digraphs （SDG） capture the direction of the effect. It should be mentioned that there are loops in ...Digraph-based causal models have been widely used to model the cause and effect behavior of process systems. Signed digraphs （SDG） capture the direction of the effect. It should be mentioned that there are loops in SDG generated from chemical process. From the point of the inherent operability, the worst unsafe factor is the SDG having positive loops that means any disturbance occurring within the loop will propagate through the nodes one by one and are amplified gradually, so the system may lose control, which may lead to an accident. So finding the positive loops in a SDG and treating these unsafe factors in a proper manner can improve the inherent safety of a chemical process. This article proposed a method that can detect the above-mentioned unsafe factors in the proc- ess conceptual design stage automatically through the analysis of the SDG generated from the chemical process. A case study is illustrated to show the working of the algorithm, and then a complicated case from industry is studied to depict the effectiveness of the proposed algorithm.展开更多
In this paper, we study the bases and base sets of primitive symmetric loop-free （generalized） signed digraphs on n vertices. We obtain sharp upper bounds of the bases, and show that the base sets of the classes of ...In this paper, we study the bases and base sets of primitive symmetric loop-free （generalized） signed digraphs on n vertices. We obtain sharp upper bounds of the bases, and show that the base sets of the classes of such digraphs are （2, 3,..., 2n - 1}. We also give a new proof of an important result obtained by Cheng and Liu.展开更多
Recently, the primitive symmetric signed digraphs on $n$ vertices with the maximum base 2n and the primitive symmetric loop-free signed digraphs on n vertices with the maximum base 2n-1 are characterized, respectively...Recently, the primitive symmetric signed digraphs on $n$ vertices with the maximum base 2n and the primitive symmetric loop-free signed digraphs on n vertices with the maximum base 2n-1 are characterized, respectively. In this paper, the primitive symmetric signed digraphs with loops on n vertices with the base 2n-1 are characterized, and then the primitive symmetric signed digraphs on n vertices with the second maximum base 2n-1 are characterized.展开更多
Let S be a primitive non-powerful symmetric loop-free signed digraph on even n vertices with base 3 and minimum number of arcs. In [Lihua YOU, Yuhan WU. Primitive non- powerful symmetric loop-free signed digraphs with...Let S be a primitive non-powerful symmetric loop-free signed digraph on even n vertices with base 3 and minimum number of arcs. In [Lihua YOU, Yuhan WU. Primitive non- powerful symmetric loop-free signed digraphs with given base and minimum number of arcs. Linear Algebra Appl., 2011, 434（5）, 1215-1227], authors conjectured that D is the underlying digraph of S with exp（D）= 3 if and only if D is isomorphic to EDn,3,3, where EDn,3,3 = （V, A） is a digraph with V = {1, 2,..., n}, A = {（1, i）, （i, 1） [ 3 〈： i 〈 n} U {（2i - 1, 2i）, （2i, 2i - 1） [ 2 〈 〈 2} U {（2, 3）, （3, 2）, （2, 4）, （4, 2）}）. In this paper, we show the conjecture is true and completely characterize the underlying digraphs which have base 3 and the minimum number of arcs.展开更多
In this paper,an asymmetric bipartite consensus problem for the nonlinear multi-agent systems with cooperative and antagonistic interactions is studied under the event-triggered mechanism.For the agents described by a...In this paper,an asymmetric bipartite consensus problem for the nonlinear multi-agent systems with cooperative and antagonistic interactions is studied under the event-triggered mechanism.For the agents described by a structurally balanced signed digraph,the asymmetric bipartite consensus objective is firstly defined,assigning the agents'output to different signs and module values.Considering with the completely unknown dynamics of the agents,a novel event-triggered model-free adaptive bipartite control protocol is designed based on the agents'triggered outputs and an equivalent compact form data model.By utilizing the Lyapunov analysis method,the threshold of the triggering condition is obtained.Subsequently,the asymptotic convergence of the tracking error is deduced and a sufficient condition is obtained based on the contraction mapping principle.Finally,the simulation example further demonstrates the effectiveness of the protocol.展开更多
This paper utilizes the internal model principle based method to analyze the effects of time delays on robust bipartite output regulation.In the considered system setting both input and communication delays are presen...This paper utilizes the internal model principle based method to analyze the effects of time delays on robust bipartite output regulation.In the considered system setting both input and communication delays are presented,unfortunately failing conventional protocols and closed-loop analysis tools.For such a challenge,a distributed protocol equipped with a dynamical compensator subject to communication delay is proposed without employing the information of the exosystem's output,and a regulator equation with a matrix exponential function is utilized to characterize the dynamics of the closed-loop delayed system.Further,the protocol gains are shown to be determined in terms of the solution of a parametric algebraic Riccati equation,and sufficient conditions are obtained to describe robust bipartite output regulation with time delays.A simulation example illustrates the effectiveness of the proposed approach.展开更多
文摘Digraph-based causal models have been widely used to model the cause and effect behavior of process systems. Signed digraphs （SDG） capture the direction of the effect. It should be mentioned that there are loops in SDG generated from chemical process. From the point of the inherent operability, the worst unsafe factor is the SDG having positive loops that means any disturbance occurring within the loop will propagate through the nodes one by one and are amplified gradually, so the system may lose control, which may lead to an accident. So finding the positive loops in a SDG and treating these unsafe factors in a proper manner can improve the inherent safety of a chemical process. This article proposed a method that can detect the above-mentioned unsafe factors in the proc- ess conceptual design stage automatically through the analysis of the SDG generated from the chemical process. A case study is illustrated to show the working of the algorithm, and then a complicated case from industry is studied to depict the effectiveness of the proposed algorithm.
基金Supported by the National Natural Science Foundation of China(Grant Nos.1090106111071088)the Zhujiang Technology New Star Foundation of Guangzhou(Grant No.2011J2200090)
文摘In this paper, we study the bases and base sets of primitive symmetric loop-free （generalized） signed digraphs on n vertices. We obtain sharp upper bounds of the bases, and show that the base sets of the classes of such digraphs are （2, 3,..., 2n - 1}. We also give a new proof of an important result obtained by Cheng and Liu.
基金Supported by the National Natural Science Foundation of China(Grant Nos.1090106111071088)+1 种基金the Zhujiang Technology New Star Foundation of Guangzhou(Grant No.2011J2200090)Program on International Cooperation and Innovation of Guangdong Province Education Department(Grant No.2012gjhz0007)
文摘Recently, the primitive symmetric signed digraphs on $n$ vertices with the maximum base 2n and the primitive symmetric loop-free signed digraphs on n vertices with the maximum base 2n-1 are characterized, respectively. In this paper, the primitive symmetric signed digraphs with loops on n vertices with the base 2n-1 are characterized, and then the primitive symmetric signed digraphs on n vertices with the second maximum base 2n-1 are characterized.
基金Supported by the National Natural Science Foundation of China(Grant Nos.1090106111071088)+1 种基金Programon International Cooperation and Innovation,Department of Education,Guangdong Province(Grant No.2012gjhz0007)the Zhujiang Technology New Star Foundation of Guangzhou City(Grant No.2011J2200090)
文摘Let S be a primitive non-powerful symmetric loop-free signed digraph on even n vertices with base 3 and minimum number of arcs. In [Lihua YOU, Yuhan WU. Primitive non- powerful symmetric loop-free signed digraphs with given base and minimum number of arcs. Linear Algebra Appl., 2011, 434（5）, 1215-1227], authors conjectured that D is the underlying digraph of S with exp（D）= 3 if and only if D is isomorphic to EDn,3,3, where EDn,3,3 = （V, A） is a digraph with V = {1, 2,..., n}, A = {（1, i）, （i, 1） [ 3 〈： i 〈 n} U {（2i - 1, 2i）, （2i, 2i - 1） [ 2 〈 〈 2} U {（2, 3）, （3, 2）, （2, 4）, （4, 2）}）. In this paper, we show the conjecture is true and completely characterize the underlying digraphs which have base 3 and the minimum number of arcs.
基金supported in part by the National Natural Science Foundation of China(U1804147,61833001,61873139,61573129)the Innovative Scientists and Technicians Team of Henan Polytechnic University(T2019-2)the Innovative Scientists and Technicians Team of Henan Provincial High Education(20IRTSTHN019)。
文摘In this paper,an asymmetric bipartite consensus problem for the nonlinear multi-agent systems with cooperative and antagonistic interactions is studied under the event-triggered mechanism.For the agents described by a structurally balanced signed digraph,the asymmetric bipartite consensus objective is firstly defined,assigning the agents'output to different signs and module values.Considering with the completely unknown dynamics of the agents,a novel event-triggered model-free adaptive bipartite control protocol is designed based on the agents'triggered outputs and an equivalent compact form data model.By utilizing the Lyapunov analysis method,the threshold of the triggering condition is obtained.Subsequently,the asymptotic convergence of the tracking error is deduced and a sufficient condition is obtained based on the contraction mapping principle.Finally,the simulation example further demonstrates the effectiveness of the protocol.
基金supported in part by the National Natural Science Foundation of China under Grant No.61973183in part by the Youth Creative Team Sci-Tech Program of Shandong Universities under Grant No.2019KJI007。
文摘This paper utilizes the internal model principle based method to analyze the effects of time delays on robust bipartite output regulation.In the considered system setting both input and communication delays are presented,unfortunately failing conventional protocols and closed-loop analysis tools.For such a challenge,a distributed protocol equipped with a dynamical compensator subject to communication delay is proposed without employing the information of the exosystem's output,and a regulator equation with a matrix exponential function is utilized to characterize the dynamics of the closed-loop delayed system.Further,the protocol gains are shown to be determined in terms of the solution of a parametric algebraic Riccati equation,and sufficient conditions are obtained to describe robust bipartite output regulation with time delays.A simulation example illustrates the effectiveness of the proposed approach.
