• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.7 no.1
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• pp.38-44
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• 2011

In this study, heating performance and energy consumption characteristics with control strategies for central heating system were researched by the simulation. The simulation analysis is made by TRNSYS ver. 15 with the actual data. The parametric study on proportional factor, control time interval and outdoor air temperatures changes were done to compare control characteristics and energy performance, respectively. As a result, the simulation results with various parameter changes show good heating performance and energy saving.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.1
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• pp.17-23
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• 2004

The semi-active suspension system is getting widely adopted in passenger vehicles for its ability to improve ride comfort over the passive suspension system while not degrading driving safety. A key to the success is to develop practical controllers that yield performance enhancement over the passive damper under various driving conditions. To this end, several control strategies have been studied and evaluated in this research in consideration of practical aspects such as nonlinearity and dynamics of the damper. From simulation results. it has been observed that, with the proposed control schemes, ride comfort can be significantly upgraded while suppressing degradation of driving safety.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.3
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• pp.1-12
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• 2003

The complexity of the papermaking system accelerates interactions between a large number of variables involved. The process operation, therefore, is subject to frequent perturbations by disturbance. Dynamic modelling is a useful tool for characterizing the transient behavior and selecting the best control strategies to reject disturbances. In this study we developed a dynamic simulation model of a fine paper production process, which consists of stock preparation, wire sections, white water circulations, and broke system. It focused on dynamic simulation in its role for developing control strategies and studying control loop dynamics related to filler loading for ash control. The results emphasized the importance of filler-loading position and length of control loop for rapid ash control and process stabilization.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.302-305
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• 1996

This paper presents a visual servoing combined by Neural Network with optimal structure and predictive control for robotic manipulators to tracking or grasping of the moving object. Using the four feature image information from CCD camera attached to end-effector of RV-M2 robot manipulator having 5 dof, we want to predict the updated position of the object. The Kalman filter is used to estimate the motion parameters, namely the state vector of the moving object in successive image frames, and using the multi layer feedforward neural network that permits the connection of other layers, evolutionary programming(EP) that search the structure and weight of the neural network, and evolution strategies(ES) which training the weight of neuron, we optimized the net structure of control scheme. The validity and effectiveness of the proposed control scheme and predictive control of moving object will be verified by computer simulation.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.5
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• pp.334-341
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• 2021

Operation modes and control strategies for single-phase mobility charging station utilizing photovoltaic (PV) generation and energy storage systems (ESS) are proposed. This approach generates electric power from PV to transmit the mobility, ESS, and then transfer it to the grid when surplus electric power is generated during daytime. However, the PV power cannot be generated during night-time, and ESS and the mobility system can be charged using grid power. The power balance control based on power fluctuations and the resonant current control that can compensate harmonic components have been added to increase the stability of the system. The MATLAB/Simulink simulation was carried out to verify the proposed control method, and the 2-kW single-phase grid-tied PV-ESS smart mobility charger was built and tested.

• International journal of advanced smart convergence
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• v.12 no.4
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• pp.111-118
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• 2023

In the ever-changing landscape of finance, the fusion of artificial intelligence (AI)and pair trading strategies has captured the interest of investors and institutions alike. In the context of supervised machine learning, crafting precise and accurate labels is crucial, as it remains a top priority to empower AI models to surpass traditional pair trading methods. However, prevailing labeling techniques in the financial sector predominantly concentrate on individual assets, posing a challenge in aligning with pair trading strategies. To address this issue, we propose an inventive approach that melds the Triple Barrier Labeling technique with pair trading, optimizing the resultant labels through genetic algorithms. Rigorous backtesting on cryptocurrency datasets illustrates that our proposed labeling method excels over traditional pair trading methods and corresponding buy-and-hold strategies in both profitability and risk control. This pioneering method offers a novel perspective on trading strategies and risk management within the financial domain, laying a robust groundwork for further enhancing the precision and reliability of pair trading strategies utilizing AI models.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.3
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• pp.249-255
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• 2010

The paper proposes a new type of robust speed control strategy for permanent magnet synchronous motor by using PD-sliding mode hybrid control. The PD control has a good performance in the transient region while the sliding mode controller provides the robustness against system uncertainties. Taking advantages of the two control strategies, the proposed control method utilizes the PD control in the approaching region to the sliding surface and the sliding mode control near at the sliding surfaces. The chattering problem of the sliding mode controller is eliminated by applying the saturation function for the switching function of the sliding mode control. The stability of the sliding mode control is verified by using Lyapunov function with the proper selection of variable gains. It is shown that with this simple switching algorithm, stability of the overall hybrid control system is ensured. Through the simulations, the PD-sliding mode algorithm is shown to have a good performance in the transient response as well as being robust against disturbances. The robustness of the PD-sliding mode algorithm is further demonstrated against various external disturbances in the real experiments of SPMSM motor control.

• 대한예방의학회:학술대회논문집
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• 2001.10a
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• pp.168-169
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• 2001

• Korean Journal of Childcare and Education
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• v.14 no.3
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• pp.59-76
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• 2018

Objective: The purpose of this study was to examine the relationships among teachers' resilience, difficulty in emotional regulation, and teaching strategies for behavior problems of children. Methods: A total of 200 day care and kindergarten teachers were surveyed. The collected data were analyzed by Pearson's correlation and multiple regression. Results: First, teachers' resilience, difficulty in emotional regulation and teaching strategies for children with behavior problems were significantly related. Teachers' resilience showed a positive correlation with teachers' positive prevention and reaction strategies but showed a negative correlation with teachers' negative reaction strategies. Among the teachers' difficulty in emotional regulation, the factor of difficulty for impulsive control and lack of attention showed negative correlations with teachers' prevention and positive reaction strategies. Second, teachers' resilience and difficulty in emotional regulation significantly explained the teaching strategies for children with behavior problems. Teachers' resilience was found to be the most important variable explaining teaching strategies for children with behavior problems. Conclusion/Implications: This study revealed that teachers' resilience and difficulties in emotional regulation were important psychological and emotional characteristics for teachers when teaching children with behavior problems.

• Korean Journal of Child Studies
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• v.32 no.5
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• pp.135-150
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• 2011

The purpose of this study was to examine the interaction strategies used by typically developing boys and girls in their dealings with young children with ADHD in free play situations in inclusive classes. This was done in order to gain an in-depth understanding of the meaning of their interaction strategies. The subjects were 52 typically developing children (comprising 27 boys, 25 girls) and 3 young children with ADHD. The findings were as follows : First, the overall frequency of interaction strategies with the young children with ADHD was greater among the young female children (n = 372) than the young male children (n = 298). Second, when the utterance strategies of the male and female children were sub-categorized, both the male children (79.5%) and the female children (57.0%) mostly made use of avoidance strategies, one of the typical withdrawal strategies. Third, the interaction strategy of control represented 42.0 percent and as such was identified as the most prevalent interaction strategy utilized by the young male children studied. In the case of the young female children, obliging strategies were the most common interaction strategies representing 33.1 percent of the total used. In the light of the findings yielded from this study, some educational recommendations are provided.