• International Journal of Air-Conditioning and Refrigeration
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• v.11 no.1
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• pp.10-16
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• 2003

The present study performs an experimental measurement on transient thermal response of an air-conditioned space by a variable air volume (VAV) system with a PI(pro-portional-integral) control logic. A thermal chamber with a PI controlled VAV unit is constructed to verify the previously suggested stratified multi-zone model. The effects of thermal parameters and control parameters such as supply air temperature and PI control factor are investigated by implementing the thermal chamber test. The experimental results obtained show that transient behavior of the air-conditioned space-temperature is in good accordance with the simulation results of the stratified thermal model.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.6
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• pp.1425-1434
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• 2014

The purpose of this study was tried to identify the effect of nursing students' learning motivation in microbiology through microbiology laboratory practice based on the Keller's ARCS model. In order to achieve this research, this study was designed a quasi-experimental pre-post tests control group. Experimental group received a microbiology theory and practice based on ARCS model and control group received microbiology theory only. To identify the microbiology learning motivation effect to nursing student, we measured learning motivation by Keller's ARCS model that consisted of attention, relevance, confidence, and satisfaction. The major results of the experimental group showed significantly higher level of total learning motivation and all four subcategories compared to control group. Based upon the above results, microbiology laboratory practice might be beneficial for the nursing students to motivate microbiology learning.

• Nuclear Engineering and Technology
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• v.52 no.8
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• pp.1611-1625
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• 2020

We propose a scaled-down experimental model of vertical air-natural convection channels by applying the modified Ishii-Kataoka scaling method with the assistance of numerical analyses to the Reactor Vault Cooling System (RVCS) of the Proto-type Gen-IV Sodium-cooled fast reactor (PGSFR) being developed in Korea. Two major non-dimensional numbers (modified Richardson and Friction number) from the momentum equation and Stanton number from the energy balance equation were identified to design the scaled-down experimental model to assimilate thermal-hydraulic behaviors of the natural convective air-cooling channel of RVCS. The ratios of the design parameters in the PGSFR RVCS between the prototype and the scaled-down model were determined by setting Richardson and Stanton number to be unity. The friction number which cannot be determined by the Ishii-Kataoka method was estimated by numerical analyses using the MARS-KS system code. The numerical analyses showed that the friction number with the form loss coefficient of 2.0 in the scale-down model would result in an acceptable prediction of the thermal-hydraulic behavior in RVCS. We also performed experimental benchmarking using the scaled-down model with the MARS-KS simulations to verify the appropriateness of the scale-down model, which demonstrated that the temperature rises and the average air flow velocity measured in the scale-down model.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.4
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• pp.43-51
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• 2001

An experimental modal analysis is the process to identify structure's dynamic characteristics such as resonant frequencies, damping values and mode shapes. An experimental model was made of stainless steel in the shape of a circular cylindrical shell and installed on the test bed with jigs. For investigating vibrational characteristics of the continuous circular cylindrical shell with intermediate supports, modal testing is performed by using impact hammer, accelerometer and 8-channel FFT analyzer. The frequency response function(FRF) measurements are also made on the experimental model within the frequency range from 0 to 4kHz. Modal parameters are identified from resonant peaks in the FRF's and animated deformation patterns associated with each of the resonances are shown on a computer screen. The experimental results are compared with analytical and FEA results.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1998.10a
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• pp.249-257
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• 1998

Vibration-resistant rubbers, whose elastic and shear behaviors are similar to viscoelastic materials, are used to make bracing dampers to reduce the building vibration. Experimental study is carried out to find the vibration characteristics of the dampers installed in the building model. The natural frequencies and modal damping ratios are obtained from the free vibration test and Fourier analysis. Shaking table test is performed to find the response behavior of the building model under earthquake loading. The present experimental study shows that the bracing dampers have the behavior of viscoelastic dampers, which increase the modal damping ratios and viscoelastic characteristics.

• Journal of Biosystems Engineering
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• v.15 no.1
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• pp.44-51
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• 1990

Four models in current use for cereal grain drying, equilibrium model, Morey model, partial differential equation model and simplified partial differential equation model, were modified to be suitable for natural air drying of barley. The predicted by the four models and experimental results were compared. Three models except equilibrium model predicted moisture comtent and grain temperature very well. But equilibrium model overpredicted moisture content and grain temperature of bottom layer. The degree of prediction of the four models for relative humidities of exhaust air didn't differ much from one another and equally the four models predicted relative humidity statisfatorily. Morey model took much shorter computing time than any other models. Therefore, considering the degree of prediction and computing time Morey model was the most suitable for natural air drying of barley.

• Steel and Composite Structures
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• v.15 no.3
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• pp.247-266
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• 2013

This paper presents a comparison of results obtained by a newly developed numerical model for predicting the behaviour of structures under fire with experimental study carried out on heated and simply supported steel beam elements. A newly developed numerical model consists of three submodels: 3D beam model designed for calculating the inner forces in the structure, 2D model designed for calculation of stress and strain distribution over the cross section, including the section stiffness, and 3D transient nonlinear heat transfer model that is capable of calculating the temperature distribution along the structure, and the distribution over the cross section as well. Predictions of the calculated temperatures and vertical deflections obtained by the numerical model are compared with the results of the inhouse experiment in which steel beam element under load was heated for 90 minutes.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.7
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• pp.556-562
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• 2002

This paper studies the identification of a combustion model, which is used to design a linear controller of a steam generation quantity and harmful exhaust gases of a Refuse Incineration Plant(RIP). Even though the RIP has strong nonlinearities and complexities, it is identified as a MIMO parametric ARX model from experimental input-output data sets. Unknown model parameters are decided from experimental input-output data sets, using system identification algorithm based on Instrumental Variables(IV) method. It is shown that the identified model well approximates the input-output combustion characteristics.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.10
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• pp.1034-1042
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• 2009

In this paper, the magic formula model was applied for a friction damper in a drum-type washing machine. To describe characteristics of the hysteretic damping force, Physical tests were first carried out to get experimental results using an MTS machine. Then, parameters for the magic formula model were determined from the experimental curves. The ADAMS and MATLAB programs were used for the multibody modeling of the damper and process for parameter identification. The model of drum-type washing machine was applied for a dynamic model of friction damper, in which the accuracy of the proposed damper model was verified.

• Computers and Concrete
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• v.17 no.2
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• pp.157-172
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• 2016

This paper presents a Strut-and-Tie Model for reinforced concrete (RC) columns subject to lateral loading. The proposed model is based on the loading path for the post-yield state, and the geometries of struts and tie are determined by the stress field of post-yield state. The analysis procedure of the Strut-and-Tie Model is that 1) the shear force and displacement at the initial yield state are calculated and 2) the relationship between the additional shear force and the deformation is determined by modifying the geometry of the longitudinal strut until the ultimate limit state. To validate the developed model, the ultimate strength and associated deformation obtained by experimental results are compared with the values predicted by the model. Good agreements between the proposed model and the experimental data are observed.