• Communications of the Korean Mathematical Society
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• v.28 no.3
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• pp.603-613
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• 2013

In 2009, Zheng and Miao [B. Zheng and S.-X. Miao, Two new modified Gauss-Seidel methods for linear system with M-matrices, J. Comput. Appl. Math. 233 (2009), 922-930] considered the modified Gauss-Seidel method for solving M-matrix linear system with the preconditioner $P_{max}$. In this paper, we consider the modified Gauss-Seidel method for solving the linear system with the generalized preconditioner $P_{max}({\alpha})$, and study its convergent properties when the coefficient matrix is an H-matrix. Numerical experiments are performed with different examples, and the numerical results verify our theoretical analysis.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.1
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• pp.9-16
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• 2010

This paper presents supervisor control methods at a matrix converter controlled overhead crane system based on a controller area network (CAN). Four induction motors are used to drive the gantry, trolley, and hoist at he crane and each motor is controlled by the matrix converter with direct torque control (DTC). Both the position control algorithm and the supervisor control system using CAN are introduced. Simulation and experimental results are carried out to verify the performance of position control at the matrix converter controlled crane system.

• Journal of information and communication convergence engineering
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• v.3 no.4
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• pp.172-175
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• 2005

In this paper, a new method to get the optimum channel capacity of a Multiple-Input Multiple­Output (MIMO) system is presented. The proposed method exploits the diagonal structure of channel matrix to maximize the channel capacity. The diagonal format of the channel matrix is formed by multiplying the transmitted signal with the pre-compensated channel PCC) matrix. Numerical simulations show that the proposed method exploiting the diagonal structure of channel matrix could significantly increase the system capacity compared with the system without applying the diagonal structure of channel matrix.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.4
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• pp.515-522
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• 2015

Through the correspondence works with IEC in the smart grid fields and power IT fields, we set up the interpretation work procedure and defined the work rule for correspondence by analyzing the work results. In addition, we suggest cases for discussion of terms and definitions in the IEC and analyze them and then propose a matrix classification system for standardization to solve the cases for discussion. The matrix classification system with 3-axes of classification has been applied to newly emerging terminologies followed by smart gird. We drew the usefulness in search of terms in application fields and showed the cases of applying the matrix classification. The IEC Electropedia classification standard is unclear and the classification is mixed with principle, application and product areas. We proposed a new working group in IEC TC1 for research on the matrix classification system and then TC 1 decided to organize a new WG titled in the "IEV structure and supporting tools".

• Journal of Electrical Engineering and Technology
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• v.5 no.2
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• pp.299-306
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• 2010

This paper proposes a new doubly-fed induction generator (DFIG) system using a matrix converter controlled by direct duty ratio pulse-width modulation (DDPWM) scheme. DDPWM is a recently proposed carrier based modulation strategy for matrix converters which employs a triangular carrier and voltage references in a voltage source inverter. By using DDPWM, the matrix converter can directly and effectively generate rotor voltages following the voltage references within the closed control loop. The operation of the proposed DFIG system was verified through computer simulation and experimental works with a hardware simulator of a wind power turbine, which was built using a motor-generator set with vector drive. The simulation and experimental results confirm that a matrix converter with a DDPWM modulation scheme can be effectively applied for a DFIG wind power system.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.2
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• pp.321-330
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• 2001

Magnetic bearing system is frequently used for high-speed rotating machines because of its frictionless property. But the magnetic bearing system needs feedback controller for stabilization. This paper presents a robust controller design by using linear matrix inequality for magnetic bearing system which shows the control performance and robust stability under the physical parameter perturbations. To the end, the validity of the designed controller is investigated through computer simulation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.6
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• pp.985-993
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• 2008

This paper proposes a new DFIG(Doubly-Fed Induction Generator) system using matrix converter, which is very effectively used for interconnecting the wind power system to the power grid. The operation of proposed system was verified by computer simulations with PSCAD/EMTDC software. The feasibility of hardware implementation was conformed by experimental works with a laboratory scaled-model of wind power system. The laboratory scaled-model was built using a motor-generator set with vector drive system, and a matrix converter with DSP(Digital Signal Processor). The operation of scaled-model was tested by modeling the specific variable-speed wind turbine using the real wind data in order to make the scaled-model simulate the real wind power system as close as possible. The simulation and experimental results confirm that matrix converter can be applied for the DFIG system.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.6
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• pp.741-761
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• 2018

A shipyard is an Engineer To Order (ETO) company that designs and manufactures new products when orders are placed. Various tasks are concurrently performed, thereby making process management considerably important. It is particularly important to plan and control production activities because production constitutes the largest part of the overall process. Therefore, this study focuses on the development of a production planning system based on an Advanced Planning System (APS). An APS is an integrated planning system that targets supply chain processes in accordance with the principles of hierarchical planning. In this study, a Supply Chain Planning Matrix (SCP-Matrix), which is used as a guideline for APS development, is designed through analysis of shipyard cases. Then, we define the process in detail, starting from long-term production plan as the initial application, and design and implement a long-term production planning system using a component-based development.

• International Journal of Automotive Technology
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• v.2 no.3
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• pp.117-122
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• 2001

For a dynamic analysis of a constrained multibody system, it is necessary to have a routine for satisfying kinematic constraints. LU decomposition scheme, which is used to divide coordinates into dependent and independent coordinates, is efficient but has great difficulty near the singular configuration. Other method such as the projection matrix, which is more stable near a singular configuration, takes longer simulation time due to the large amount of calculation for decomposition. In this paper, the row space and the null space of the Jacobian matrix are proposed by using the pseudo-inverse method and the projection matrix. The equations of the motion of a system are replaced with independent acceleration components using the null space of the Jacobian matrix. Also a new hybrid method is proposed, combining the LU decomposition and the projection matrix. The proposed hybrid method has following advantages. (1) The simulation efficiency is preserved by the LU method during the simulation. (2) The accuracy of the solution is also achieved by the projection method near the singular configuration.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.652-657
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• 1987

The Dynamic Matrix Control(DMC) technique was applied to nonlinear and nonminimum phase system. System model was identified by using Least Square method. Desired output trajectory was prespecified and input suppression parameter was also introduced. It was shown that DMC technique worked with great success in solving both nonminimum phase system and nonlinear system.