• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.1137-1143
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• 2006

The purpose of this research lays on examining the adequacy of the hybrid ventilation system. The hybrid ventilation system must satisfy the next to be used. Firstly, the cold-draft phenomenon must not exist in the occupied zone. Secondly, the condensation must not happen on the surfaces of vents. Thirdly, the flow of make-up air must be happened in an each space by exhausted air of a rest room and living room. We used an examination and CFD method to verify these. Trough the examination of air-vents, We confirmed that the cold-draft to be induced by make-up air does not happen and could not find the condensation in the limits of outdoor temperature higher than 265K. Through CFD simulation, We confirmed that the rapid temperature change existed only within 0.5m the occupied zone and the flow of air was happened in an each space by only exhausted air in the rest room and living room. Consequently, the hybrid system is possible method to an apartment house.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.7
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• pp.883-888
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• 2014

The paper describes the parameter tuning of power system stabilizer (PSS) for a power plant based on hybrid system modeling. The existing tuning method based on bode plot and root locus is well applied to keep power system stable. However, due to linearization of power system and an assumption that the parameter ratio of the lead-lag compensator in PSS is fixed, the results cannot guarantee the optimal performances to damp out low-frequency oscillation. Therefore, in this paper, hybrid system modeling, which has a DAIS (differential-algebraic-impusive-switched) structure, is applied to conduct nonlinear modeling for power system and find optimal parameter set of the PSS. The performances of the proposed method are carried out by time domain simulation with a single machine connected to infinite bus (SMIB) system.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.3
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• pp.1-9
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• 2022

The aircraft targeted in this study is a vertical take-off and landing aircraft with 4 to 5 passengers, and the propulsion system for the aircraft is a distributed hybrid propulsion system that uses a gas turbine engine and a battery pack as the main power source to supply the power required by multiple motors. In this study, a design/analysis platform for a hybrid propulsion system was developed using the MATLAB/Simulink program based on the preliminary design results. Through simulation analysis, the output characteristics and operating range of each power source according to the mission profile were confirmed, and through this, the feasibility of the preliminary design result was confirmed.

• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.6
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• pp.33-43
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• 2010

This paper deals with the hybrid structural test technique which has been introduced and studied currently in Korea. In this study, a Mini-MOST system which was developed as a part of NEES research was modified and improved to reduce the total simulation time to half of the original system. Using the proposed system together with the 2 dimensional small steel frame specimen, the validity and efficiency of the hybrid test technique is investigated. Even though the hybrid test has been developed as an alternative to the shaking table test and has been studied and applied for a long time in several countries, no attempt has been made to compare it directly with the shaking table test. Therefore, in this study, the hybrid test results are compared with those of the shaking table test as well as with a numerical simulation for the verification of hybrid test. From the comparison and analysis of the test results, it is concluded that the hybrid test can simulate the actual seismic behavior of structural systems very accurately and it can be a good alternative to the shaking table test.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.4
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• pp.168-178
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• 2008

The hybrid simulation test method is a versatile technique for evaluating the seismic performance of structures by seamlessly integrating both physical and numerical simulations of substructures into a single test mode. In this paper, a software framework that integrates computational and experimental simulation has been developed to simulate and test a bridge structural system under earthquake loading. Using hybrid simulation, the seismic response of complex bridge structural systems partitioned into multiple large-scale experimental and computational substructures at networked distributed experimental and computational facilities can be evaluated. In this paper, the examples of application are presented in terms of a bridge model with soil-foundation-structure interaction.

• Smart Structures and Systems
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• v.33 no.1
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• pp.1-16
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• 2024

The investigation on vehicle-bridge coupling system (VBCS) is crucial in bridge design, bridge condition evaluation, and vehicle overload control. A real-time hybrid testing (RTHT) method for VBCS (RTHT-VBCS) is proposed in this paper for accurately and economically disclosing the dynamic performance of VBCSs. In the proposed method, one of the carriages is chosen as the experimental substructure loaded by servo-hydraulic actuator loading system in the laboratory, and the remaining carriages as well as the bridge structure are chosen as the numerical substructure numerically simulated in one computer. The numerical substructure and the experimental substructure are synchronized at their coupling points in terms of force equilibrium and deformation compatibility. Compared to the traditional iteration experimental method and the numerical simulation method, the proposed RTHT-VBCS method could not only obtain the dynamic response of VBCS, but also economically analyze various working conditions. Firstly, the theory of RTHT-VBCS is proposed. Secondly, numerical models of VBCS for RTHT method are presented. Finally, the feasibility and accuracy of the RTHT-VBCS are preliminarily validated by real-time hybrid simulations (RTHSs). It is shown that, the proposed RTHT-VBCS is feasible and shows great advantages over the traditional methods, and the proposed models can effectively represent the VBCS for RTHT method in terms of the force equilibrium and deformation compatibility at the coupling point. It is shown that the results of the single-degree-of-freedom model and the train vehicle model are match well with the referenced results. The RTHS results preliminarily prove the effectiveness and accuracy of the proposed RTHT-VBCS.

• Journal of Positioning, Navigation, and Timing
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• v.5 no.2
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• pp.97-107
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• 2016

Military Autonomous Underwater Vehicle (AUV) is utilized to search a mine under the sea. This paper presents design and performance verification of real-time hybrid navigation system for AUV. The navigation system uses Doppler Velocity Log (DVL) integration method to correct INS error in underwater. When the AUV is floated on the water, the accumulated error of navigation algorithm is corrected using position/velocity of GPS. The navigation algorithm is verified using 6 Degree Of Freedom (DOF) simulation, Program In the Loop Simulation (PILS). Finally, the experiments are performed in real sea environment to prove the reliability of real-time hybrid navigation algorithm.

• Journal of Power System Engineering
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• v.17 no.5
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• pp.128-137
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• 2013

Modern transmission technologies such as automated manual transmission(AMT) and dual clutch transmission(DCT) are interested to all manufactures due to their fuel efficiency and driver's convenience, especially in a hybrid system. AMT has advantages in that they have a high efficiency of manual transmissions(MT) and offer operation convenience similar to automatic transmissions(AT), but it has some disadvantages in that they have torque gap during gear shift and shift time. To reduce disadvantages, it is necessary to evaluate errors and characteristics as a developing simulation model before experimental verification. The purpose of this study is to develop virtual components and simulate the transient response of AMT. A dynamic AMT model and a control logic for an integrated vehicle model have been developed using Matlab/Simulink as a simulation platform. In this paper, the clutch model to describe the stick-slip transition mode and the transmission model to describe the neutral gear shifting is introduced and compared with each other.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.4
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• pp.484-496
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• 2009

The strengthened regulations for atmospheric emissions from ships like MARPOL Annex VI have caused a necessity of new, alternative power system in ships for the low pollutant emissions and the high energy efficiency. This paper attempts to investigate the configuration of SOFC/GT hybrid power system for LNG tanker taking into account the safety and to analyze the influence of design parameters on the system performance. The simulation results provide the basic data for the design and efficiency improvement of SOFC/GT hybrid system and indicate the guidelines for the safe system operation.

• Membrane Journal
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• v.28 no.2
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• pp.90-95
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• 2018

A process design was performed for a removal of acid gases using membrane-absorption hybrid system in LNG-FPSO. Commercial process simulator Promax version 4.0 was utilized for comparing acid gases removal capabilities of amine absorption process and hybrid process. Simulation results show hybrid process could be small amine solvent circulate rate, energy consumption, equipment sizing compared to typical amine absorption process. As a result, hybrid process which is small footprint and energy saving process may be a good solution for the pre-treatment of natural gas in LNG-FPSO.