• Journal of the Korea Society for Simulation
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• v.20 no.4
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• pp.49-58
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• 2011

It is required that a developed control system should be verified using simulator in terms of functionality and reliability prior to application to a power plant that is a very critical facility in the industry. In this paper, the control model for turbine bypass system was developed for power plant simulator. In order to develop the control model for turbine bypass system, the tool that can be used to implement turbine bypass control logic was developed based on the turbine bypass control system manual. The developed tool was merged into the simulator development environment. The functionality of the developed tool was verified via the simulation based on the each function block specification. The HP turbine bypass pressure control logic was implemented using the developed tool and was integrated with process models and other control models such as boiler control model, turbine control model and boiler feed water pump turbine control model for 500 MW korean standard type fossil power plant. Finally, the validity of the developed control model was shown via simulation result under the integrated simulation environment.

• Journal of Ocean Engineering and Technology
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• v.10 no.4
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• pp.149-159
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• 1996

Multipurpose development of the coast and ocean can be considered as multifunction construction combining the functions of coastal protection, waterfront amenity and creation or rehabilitation of habitats. Multfunction development of coastal and ocean spaces can be accomplished by applying the ecosystem control structure of artificial habitats which will cultivate fishing ground with ecological harmony to the coastal protection system. To evaluate the applicability of ecosystem control structures as as fundamental coastal protection structure, wave control function of the structure is studied by numerical and physical analyses. Dimensional analysis and hydraulic experiment point out the importance of width and crest depth of ecosystem control structure, construction water depth and wave steepness. Wave control efficiency is estimated by the attenuation coefficient $(K_H)$ according to wave steepness $(H_0/L_0)$, relative constructed water depth $(h_i/H_0)$, relative berm width $(B/L_0)$ and relative crest depth $(h_B/H_0)$ of eosystem control structure. Empirical fomulas are suggested based on the results of model test by applying the multiple model based on this experimental results and numerical wave shoaling-dissipation-breaking model appears to be valid for the analysis of wave transformation around ecosystem control structure in the coastal waters.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.10
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• pp.381-386
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• 2016

An optimization algorithm is developed based on a simulation case of a single family house model equipped with PV arrays. To increase the nationwide use of PV power generation facilities, a market-competitive electricity price needs to be introduced, which is determined based on the time of use. In this study, quadratic programming optimization was applied to minimize the electricity bill while maintaining the indoor temperature within allowable error bounds. For optimization, it is assumed that the weather and electricity demand are predicted. An EnergyPlus-based house model was approximated by using an equivalent RC circuit model for application as a linear constraint to the optimization. Based on the RC model, model predictive control was applied to the management of the cooling load and electricity for the first week of August. The result shows that more than 25% of electricity consumed for cooling can be saved by allowing excursions of temperature error within an affordable range. In addition, profit can be made by reselling electricity to the main grid energy supplier during peak hours.

• Advances in Energy Research
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• v.5 no.1
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• pp.79-90
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• 2017

The main objective of load frequency control (LFC) is to keep the frequency value at nominal value and force deviation of the frequency to zero in case of load change. This paper suggests LFC by using a model predictive control (MPC), based on Integral Square Error (ISE) method designed to optimize the damping of oscillations in a two-area power system. The MPC is designed and simulated with a model system in state space, for robust performance in the system response. The proposed MPC is tuned by ISE to achieve superior efficiency. Moreover, its performance has been assessed and compared with the PI and PID conventional controllers. The settling time and overshoot with MPC are extremely minimized as compared with conventional controllers.

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.5
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• pp.5-14
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• 2003

Tracking control schemes on the precise mechanical system in presence of nonlinear dynamic friction is proposed. A nonlinear dynamic friction is regarded as the bristle friction model to compensate fer effects of friction. The conventional SMC method often shows poor tracking performance in high-precision position tracking application since it cannot completely compensate for the friction effect below a certain precision level. Thus to improve the precise position tracking performance, we propose the SMC method combined with the disturbance observer having tunable transient performance. Then this control scheme has the high precise tracking peformance as well as a good transient response when it is compared with the conventional SMC method and the similar types of observers, The experiment on the XY ball-screw drive system with the nonlinear dynamic friction confirms the feasibility of the proposed control scheme.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.5
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• pp.415-421
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• 2014

This study proposes a model-based predictive control for interleaved multi-phase DC/DC converters. The power values necessary to adjust the output voltage in the succeeding are predicted using a converter model. The output power is controlled by selecting the optimal duty cycle. The proposed method does not require controller loops and modulators for converter switching. This method can control the converter by calculating the optimal duty cycle, which minimizes the error between the reference and actual output voltage. The effectiveness of the proposed method is verified through simulations and experiments.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1044-1047
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• 1996

In this paper, GMDH(Group Method of Data Handling) algorithm, which is based on heuristic self organization to predict and identify the complex system, is applied to the control system of DC servo motor. The mathematical relation between input voltage and motor speed is obtained by GMDH algorithm. A design method of model following control system based on GMDH algorithm is developed. As a result of applying this method to DC servo motor, the simulation and experiment have shown that the developed method gives a good performance in tracking the reference model and in rejection of disturbance, in spite of constant load and changing load.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.9
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• pp.1112-1118
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• 1999

A major objective of the study is to propose a supervisory control algorithm based on the discrete event dynamic system (DEDS) model and apply it to the automation of nuclear operations. The study is motivated by the suitability of the DEDS model for simulation of man-made control action and the potential of the DEDS based supervisory control algorithm for enhanced licensibility, when implemented in nuclear plants, through design transparency due to strong analytic backgrounds. The DEDS model can analytically show the robust stability of the proposed supervisory controller providing design transpareney for enhanced licensibility when implemented in nuclear operations.

• Journal of Information Processing Systems
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• v.14 no.3
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• pp.607-620
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• 2018

The problem surrounding methods of implementing the software testing process has come under the spotlight in recent times. However, as compliance with the software testing process does not necessarily bring with it immediate economic benefits, IT companies need to pursue more aggressive efforts to improve the process, and the software industry needs to makes every effort to improve the software testing process by evaluating the Test Maturity Model integration (TMMi). Furthermore, as the software test process is only at the initial level, high-quality software cannot be guaranteed. This paper applies TMMi model to Automobile control software testing process, including test policy and strategy, test planning, test monitoring and control, test design and execution, and test environment goal. The results suggest improvement of the automobile control software testing process based on Test maturity model. As a result, this study suggest IT organization's test process improve method.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.3
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• pp.263-268
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• 2001

A new control scheme s proposed for the control of reactive batch distillation (RBD) column. A nonlinear wave model captures the essential dynamic behavior of the RBD process. The proposed control scheme is based on both Generic Model Control(GNC) and nonlinear wave model. The control scheme uses a profile position of the column as a controlled variable. Ethanol esterification process using RBD is chosen as an example process. Tight control of the distillate purity is obtained with the use of the proposed control scheme.