• Journal of applied mathematics & informatics
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• v.29 no.3_4
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• pp.563-572
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• 2011

In this paper, the Lie symmetry analysis is performed on the three mixed second-order PDEs, which arise in fluid dynamics, nonlinear wave theory and plasma physics, etc. The symmetries and similarity reductions of the equations are obtained, and the exact solutions to the equations are investigated by the dynamical system and power series methods. Then, the exact solutions to the general types of PDEs are considered through a variable transformation. At last, the symmetry and integration method is employed for reducing the nonlinear ODEs.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.221-223
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• 2005

To make real 3D vision available, we have established a volumetric 3D display system that based on rotating LED matrix. The paper introduced a method to correct the problem that pixels are not symmetrical but circumferential in space, which causes the resolution of the edge area much lower than that of the central area.

• International Journal of Control, Automation, and Systems
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• v.5 no.5
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• pp.526-538
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• 2007

This paper presents a neural network based decentralized excitation controller design for large-scale power systems. The proposed controller design considers not only the dynamics of generators but also the algebraic constraints of the power flow equations. The control signals are calculated using only local signals. The transient stability and the coordination of the subsystem control activities are guaranteed through rigorous stability analysis. Neural networks in the controller design are used to approximate the unknown/imprecise dynamics of the local power system and the interconnections. All signals in the closed loop system are guaranteed to be uniformly ultimately bounded. To evaluate its performance, the proposed controller design is compared with conventional controllers optimized using particle swarm optimization. Simulations with a three-machine power system under different disturbances demonstrate the effectiveness of the proposed controller design.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.646-648
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• 2012

In this paper, android phone information push system based on the XMPP protocol is proposed. It uses Java and eclipse development tools to create an information pushing system in android phone based on the XMPP protocol, and runs on the C/S network situation. Not only, the information can be send and receire form android phone in the PC server, but also the smack packet of the android phone is used fully by this system. Therefore, the speed of the transmission and the transfer are better than other sending sportocol in the basic XMPP protocol of the system.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.226-233
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• 2022

In the present work, a phase-field model was developed to investigate the influence of recrystallization on bubble evolution during irradiation. Considering the interaction between bubbles and grain boundary (GB), a set of modified Cahn-Hilliard and Allen-Cahn equations, with field variables and order parameters evolving in space and time, was used in this model. Both the kinetics of recrystallization characterized in experiments and point defects generated during cascade were incorporated in the model. The bubble evolution in recrystallized polycrystalline of U-Mo alloy was also investigated. The simulation results showed that GB with a large area fraction generated by recrystallization accelerates the formation and growth of bubbles. With the formation of new grains, gas atoms are swept and collected by GBs. The simulation results of bubble size and distribution are consistent with the experimental results.

• 한국전기화학회:학술대회논문집
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• 2004.06a
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• pp.219-224
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• 2004

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.924-925
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• 2005

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.186.2-187
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• 2000

• Proceedings of the Korean Institute of Landscape Architecture Conference
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• 2007.10b
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• pp.15-18
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• 2007

• Steel and Composite Structures
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• v.36 no.4
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• pp.481-492
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• 2020

To study the rail mapped deformation caused by the pier settlement of simply - supported bridges with China Railway Track System III (CRTS III) slab ballastless track (SBT) system under the mode of non-longitudinal connection ballastless track slab, this study derived an analytical solution to the mapped relationships between pier settlement and rail deformation based on the interlayer interaction mechanism of rail-pier and principle of stationary potential energy. The analytical calculation results were compared with the numerical results obtained by ANSYS finite element calculation, thus verifying the accuracy of analytical method. A parameter analysis was conducted on the key factors in rail mapped deformation such as pier settlement, fastener stiffness, and self-compacting concrete (SCC) stiffness of filling layer. The results indicate that rail deformation is approximately proportional to pier settlement. The smaller the fastener stiffness, the smoother the rail deformation curve and the longer the rail deformation area is. With the increase in the stiffness of SCC filling layer, the maximum positive deformation of rail gradually decreases, and the maximum negative deformation gradually increases. The deformation of rail caused by the pier settlement of common-span bridge structures will generate low-frequency excitation on high-speed trains.