Sun X.,Guangxi University of Finance and Economics
Nonlinear Dynamics | Year: 2013
In this article, we study the limit cycles bifurcated from a Liénard system with a heteroclinic loop connecting two nilpotent saddles. We apply expansion theory of a first-order Melnikov function to investigate the number of limit cycles near the heteroclinic loop and the center, and by some perturbation theory we find 3 limit cycles with 7 different distributions. Last, the least upper bound of the number of limit cycles bifurcated from the annulus is given by an algebraic criterion developed in J. Differ. Equ. 251, 1656-1669 (2011). © 2013 Springer Science+Business Media Dordrecht.
Peng X.,Guangxi University of Finance and Economics
Applied Mechanics and Materials | Year: 2014
In this paper, the status of the farmers’ decentralized supply chain production mode were analyzed and the current causes of low efficiency in the agricultural supply chain is presented from the perspective of market risk control mode of agricultural product supply chain. Innovation in the integration of agricultural production chain and supply chain management of agricultural products based on the characteristics of the circulation of agricultural products as well as the balance of relationship between production and demand. © (2014) Trans Tech Publications, Switzerland.
Sun X.,Guangxi University of Finance and Economics |
Yang J.,Hebei Normal University
International Journal of Bifurcation and Chaos | Year: 2012
In this paper, we study the number and distribution of small limit cycles of some Z4-equivariant near-Hamiltonian system of degree 9. Using the methods of Hopf bifurcation theory, we find that this system can have 64 small limit cycles. The configuration of 64 small limit cycles of the system is also illustrated in Fig. 1. When we let some parameters be zero, then we find that there can be 40 small limit cycles in a seventh system. © 2012 World Scientific Publishing Company.
Lai S.,Guangxi University of Finance and Economics
Future Information Engineering and Manufacturing Science - Proceedings of the 2014 International Conference on Future Information Engineering and Manufacturing Science, FIEMS 2014 | Year: 2015
With the development of English teaching, English teaching mode based on various points of view has been proposed and widely concerned. At present, creation of context as an important factor contained in English learning, can greatly improve the quality of English teaching and learning in China. In the study, it is analyzed that an improved and expanded teaching condition, foreign teachers, exchange students and details of creating context can effectively reflect the importance of context in English teaching. © 2015 Taylor & Francis Group, London.
Qin B.,Guangxi University of Finance and Economics
Information Sciences | Year: 2015
One of the advantages of rough set theory is the fact that an unknown target concept can be approximately characterized based on existing knowledge structures in a knowledge base. Knowledge reductions are one of the key problems in the study of rough set theory. In this paper, ∗-reductions and their features in a knowledge base are explored. Moreover, communication between knowledge bases is proposed based on the use of homomorphisms between relation information systems, and several invariant characterizations under homomorphisms are obtained. These results will be significant for establishing a framework for granular computing in knowledge bases. © 2015 Elsevier Inc. All rights reserved.