• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1998.10a
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• pp.274-285
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• 1998

Increasing flexibility and lightness of recently built high-rise buildings make the structures susceptible to loads such as earthquakes and winds. Therefore, higher performance vibration control systems to reduce the vibration levels are demanded more than any time in the past. One of typical active vibration control systems is the active mass damper(AMD). In this paper, an active vibration control system consisting of small shaking table, building model, sensors, signal processing board and AMD is constructed. The dynamic characteristics of these individual systems are investigated through the experimental study. The performance of the active vibration control system is verified through harmonic resonant load excitation on building model.

• International Journal of Control, Automation, and Systems
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• v.4 no.1
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• pp.63-69
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• 2006

Problems like poor security, transfer delay or packet loss occur while building network systems that are applied with TCP/TP integrate with data network systems. To solve this problem, this paper proposes the Separated Ethernet, which can give priority to the system, and by using the OPNET Modeler simulator, we will verify its performances.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.544-551
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• 2005

This paper investigates the effectiveness of the MR damper-based control systems for seismic protection of base isolated building sturcutres employing some semiactive control algorithms, such as the modified clipped-optimal control, the maximum energy dissipation, and the modulated homogeneous friction, by examining the Phase I smart base isolated benchmark building problem. The results of the numerical simulations showed that most of the control systems considered herein could be beneficial in reducing seismic responses, especially base displacement or isolator deformation, of base isolated building structures. It is also verified that another version of the modified clipped-optimal control algorithm proposed in this study and the modulated homogeneous friction algorithm are more effective than other semiactive control algorithms.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.60-65
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• 2008

The near-optimal control algorithm for central cooling and heating system has been developed for minimizing energy consumption while maintaining the comfort of indoor thermal environment in terms of the environmental variables such as time varying indoor load and outdoor temperatures. The optimal set-points of control parameters with near-optimal control are supply air and chilled or hot water temperatures. The near optimal control algorithm has been implemented by using LabVIEW program in order to analyze energy performance for central cooling and heating control system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.7
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• pp.470-477
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• 2008

The near-optimal control algorithm for central cooling system has been developed for minimizing energy consumption while maintaining the comfort of indoor thermal environment in terms of the environmental variables such as time varying indoor cooling load and outdoor temperatures. The optimal set-points of control parameters with near-optimal control are supply air and chilled water temperatures. The near optimal control algorithm has been implemented by using LabVIEW program in order to analyze energy performance for central cooling control system.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.8 no.4
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• pp.1-7
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• 2012

In this study, computer simulation for demand control strategies to save the electric energy and power price in the building central cooling system is done. The demand control and outdoor reset control algorithms are applied by consideration the electric energy and power price according to the energy consumption characteristics. The suggested control methods show better responses in the power price and energy consumption in comparison with the conventional one.

• Structural Engineering and Mechanics
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• v.19 no.1
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• pp.107-121
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• 2005

The suboptimal control rule is introduced in structural control implementation as an alternative over the optimal control because the optimal control may require large amount of processing time when applied to complex structural control problems. It is well known that any time delay in structural control implementation will cause un-synchronized application of the control forces, which not only reduce the effectiveness of an active control system, but also cause instability of the control system. The effect of time delay on the displacement and acceleration responses of building structures is studied when the suboptimal control rule is adopted. Two examples are given to show the effectiveness of the suboptimal control rule. It is shown through the examples that the present method is easy in implementation and high in efficiency and it can significantly reduce the time delay in structural control implementation without significant loss of performance.

• Journal of Convergence for Information Technology
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• v.9 no.1
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• pp.54-60
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• 2019

The recent climate change is exacerbating the external thermal environment and increasing the amount of energy used in building. Energy Plus was used to evaluate low energy technology performance of buildings responding to climate change. The test types of basic building(control) and evaporative mist system + basic building(EMS), and the analysis results of each type are compared. Energy performance evaluation result, Cooling peak load were EMS reduction compared to control is about 9%. Annual cooling load per unit area were EMS reduction compared to control is about 17%. Annual energy use per unit area were EMS reduction compared to control is about 10%. Therefore, the effect of the evaporative cooling system is considered to be good through energy reduction technology of building, according to the amount and distance of the evaporative mist system in the future research on building energy performance evaluation should be carried out.

• International Journal of Air-Conditioning and Refrigeration
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• v.14 no.3
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• pp.85-93
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• 2006

The present study has been conducted to simulate dynamics of a gas engine-driven heat pump (GHP) for the design of control algorithm. The dynamic model of a GHP was based on conservation laws of mass and energy. For the control of refrigerant pressures, actuators such as an engine throttle valve, outdoor fans, coolant three-way valves and liquid injection valves were controlled by P or PI algorithm. The simulation results were found to be realistic enough to be applied for the control algorithm design. The model could be applied to build a virtual real-time GHP system so that it interfaces with a real controller for the purpose of developing control algorithm.

• Journal of Mechanical Science and Technology
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• v.20 no.2
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• pp.278-285
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• 2006

The present study has been conducted to simulate dynamics of a gas engine-driven heat pump (GHP) for design of control algorithm. The dynamics modeling of a GHP was based on conservation laws of mass and energy. For automatic control of refrigerant pressures, actuators such as engine speed, outdoor fans, coolant three-way valves and liquid injection valves were PI or P controlled. The simulation results were found to be realistic enough to apply for control algorithm design. The model can be applied to build a virtual real-time GHP system so that it interfaces with a real controller in purpose of prototyping control algorithm.