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Zhang J.,Tianjin University | Zhang J.,Tianjin Vocational Institute | Ma J.,Tianjin University | Ma J.,Tianjin University of Finance and Economy
Nonlinear Dynamics | Year: 2012

Based on the actual competition in the Chinese property insurance market, the repeated price game model for four oligarchs with different decision rules is built. On the basis of analyzing the stabilities of eight fixed points about the four-dimensional dynamic system, the Nash equilibrium and its local stable region are discussed mainly. Then the complexity of the four-dimensional discrete dynamic system and its evolutionary process are studied. Finally, the delay feedback control method is used to control the chaos. Numerical simulation results have shown that the influence which the change of price adjustment speed has on the movement of dynamic system has a sensitive dependence on the initial conditions, and there is a strong connection between the profit of each oligarch and the price adjustment speed or the control parameters, and the corresponding economic explanation to those phenomena will have important reference values to the realistic problems. © 2012 Springer Science+Business Media B.V. Source

Junhai M.,Tianjin University | Junling Z.,Tianjin University | Junling Z.,Tianjin Vocational Institute
Nonlinear Dynamics | Year: 2012

In the oligopoly insurance market, we assumed that some oligarchs make two-period delay decisions in bounded rationality and expectation, respectively, and others make decisions with bounded rationality without the condition of delay. There also exist two cases in which only one oligarch makes a delayed decision and two oligarchs make delayed decisions at the same time. Based on the analysis of these situations, we established the corresponding dynamic price game models.We then performed a numerical simulation to the complexity state of the system with different conditions such as stability, bifurcation, and chaos, and analyzed the profits of different oligarchs when the system is in different states. The results showed that when only one oligarch makes a delayed decision, with the decrease in the price weight of period t and increase in that of periods t - 1 and t - 2, the system's stable region in the direction of the price adjustment of the oligarch with a delayed decision gets smaller. However, when there are two oligarchs with a delayed decision in the system, in the case where the delay parameters of oligarch 1 remain unchanged and the price parameters of different periods of oligarch 2 change, the system's stable region in the direction of the price adjustment of oligarch 1 does not have the obvious change as that when only one oligarch makes a delayed decision. This showed that the sensibility of one oligarch in the direction of its own price adjustment is lower than other oligarchs. In addition, in the same system with delay and when the system is in chaos, the total profit of the oligarchs is obviously less than that when the system is in a stable state. However, the use of a delayed decision may not enhance the oligarch's competitive advantages. Finally, the variable feedback control method is used to effectively control the chaos in the system. © Springer Science+Business Media B.V. 2012. Source

Qin W.,Tianjin Vocational Institute
Gongneng Cailiao/Journal of Functional Materials | Year: 2015

The injection molding of magnetic powder could cost-effectively mass-produce net shape magnets. The manufacture technology and properties testing method of composite powder and bonded NdFeB magnets from injection molding were described in detail. The effects of content of binder, additives and magnetic powder on the magnetic property, mechanical property and fluidity of injection molding magnets were investigated. Furthermore, the effect mechanism was revealed microcosmically. The injection molding bonded magnets were prepared by using the MQP-B rapidly quenching NdFeB magnetic powder and polyamide 12.The magnetic properties are: Br=0.539 T, Hcb=345.37 kA/m, Hci=681.02 kA/m, and (BH)max=47.37 kJ/m3. © 2015, Chongqing Functional Materials Periodical Press Co. Ltd. All right reserved. Source

Zong Q.,Tianjin University | Zhao Z.-S.,Tianjin University | Zhang J.,Tianjin Vocational Institute
IET Control Theory and Applications | Year: 2010

A higher order sliding mode control (SMC) with self-tuning law algorithm for uncertain non-linear systems is proposed. The method can be viewed as the finite time stabilisation based on geometric homogeneity and integral SMC. In order to reduce chattering and solve system uncertainties with unknown bound, a bipolar sigmoid function on-line adaptation and an adjustable control gain tuning approach without high-frequency switching are developed. Control system stability is ensured using the Lyapunov method. An example is given to show the effectiveness of the developed approach. © 2010 The Institution of Engineering and Technology. Source

Yu Y.,Tianjin Vocational Institute
Applied Mechanics and Materials | Year: 2014

To construct low-carbon city, the development trend of green living is gradually clear, low-carbon has become the new trend of various fields' development, and green planning, green building and low-carbon consumption also have become the mainstream of society. From the green low-carbon and minimalistic design of the packaging field starting, first expounded the importance of packaging materials' green low-carbon and its superiority analysis, and then the use of random choice model makes science choice analysis of packaging materials, further using the deterministic model analyzes the layout and color of packaging design, to provide the theoretical basis and practical new model for green low-carbon packaging and minimalistic design. © (2014) Trans Tech Publications, Switzerland. Source

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