• Korean Architects
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• no.4 s.288
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• pp.18-51
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• 1993

• The monthly packaging world
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• s.228
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• pp.81-85
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• 2012

• The Journal of the Acoustical Society of Korea
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• v.24 no.1
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• pp.21-28
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• 2005

In this Paper, the effect of stage ceiling height on the acoustic characteristics of rectangular concert halls are investigated. To find out the acoustic properties of audience area, A simple Boston Symphony Hall(BSH) model which is typically rectangular shaped was applied for computer simulation. A newly built rectangular concert hall with 400 seats was also chosen for a scale model $(1.2m{\times}0.68m{\times}0.31m)$ study and its computer simulation varing the stage ceiling height and the volume. The results show that RT increased as the stage ceiling was lowered and the difference rate of RT by its variance is from -0.09 to -0.06[sec/m].

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.7
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• pp.1159-1164
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• 2004

There is an Overhead Hoist Transport(OHT) for delivering the wafer in semiconductor processing. The transfer system is consists of carrier vehicle. rail, and support. OHTCMS(OHT Control and Management System) has to take the feature, such as the optimal control and integration with several OHT. In this paper, ESRA(Efficiency of Shortest - Route Algorithms) is proposed which can be transported optimal route and be prevented collision using the Floyd-Warshall algorithms. The proposed algorithm is verified through consecutive simulation for a long time.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.8 no.1
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• pp.21-28
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• 1994

It is very important and necessary to predict luminous enviroment in an interior space. This paper has described about energy saving and evaluated interior visual environment in a office building having on/off turning control lighting system utilizing daylight. In order to predict the interior varior illumination distribution, the scale model was made and examined under various conditions, such ad difference of window glass, and color pattern of wall, floor, and also ceiling lighting system type. This paper suggests that basic fundamental data of lighting design performance in the concept and schematic stages of design.

• Journal of Conservation Science
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• v.29 no.1
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• pp.1-14
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• 2013

The Hongjimun Ogansumun (Five-arched floodgates) is composed mainly of biotite granite, pink feldspar granite and granodiorite that are very similar with granitic rocks around the Seoul. Main damage in the floodgates was gray, yellow and predominantly white discoloration on the surface of stone blocks. All floodgates showed more discoloration in the wall than ceiling, and there were growing stalactite on the ceiling. Scientific analyses determined that the white discoloring substrates were mainly calcite. Therefore, conservation treatment was carried out to remove the substrates by using dry cleaning, high pressure cleaning and chemicals. The floodgates have been restored to good state, but it is still significantly necessary to install drainage on the top of the gates.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.9
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• pp.873-881
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• 2005

In this study, we made RFC, RCC and NCC according to the method by which polypropylene capillary tube was adopted, and evaluated cooling performance of each system through model experiments. We also investigated an applicability of the combined use of radiant cooling and dehumidification system. The results are as follows: In case of normal cooling load, RFC and RCC maintained set temperature without a condensation. But, in case of peak cooling load, RFC and RCC resulted in the lack of cooling performance and caused a condensation at the radiation surface. Consequently, the only use of polypropylene capillary tube is considered not to be enough for cooling in real application. Using the combination of a dehumidification and radiant cooling system maintained the set temperature without a condensation. NCC kept the set temperature at anytime without a condensation. It is more economic than packaged air-conditioner system due to the cooling effect of the floor surface.

• Journal of the Ergonomics Society of Korea
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• v.26 no.2
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• pp.45-59
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• 2007

The operating tasks of overhead crane have caused undue stress to the operators from physical, mental, and environmental workload. Existing workload assessment models for musculoskeletal disorders such as OWAS, RULA, and QEC have limited applicability to the crane operating tasks because they focus mainly on physical factors and do not consider the relative importance of each factor. The present study was to develop a workload assessment model customized to overhead crane operation, following a systematic process: (1) analyzing task characteristics, (2) selecting workload factors, (3) developing assessment methods, (4) establishing action levels, and (5) computerizing the assessment model. Based on literature review, worksite survey, and focus group interview, 4 physical factors (awkward posture, static posture, repetitive motion, and excessive force), 6 mental factors (visual demand, auditory demand, task complexity and difficulty, time urgency, work schedule related stress, and safety related stress), and 4 environmental factors (noise, vibration, dust, and temperature) were selected and their rating scales and relative weights were determined. Then, based on the workload assessment results of 8 overhead cranes operated at different workplaces, the action levels of each factor category were established. Finally, the crane operation assessment model was computerized for effective analysis and report preparation. The present approach is applicable to develop a customized workload assessment model for an operating task under consideration.

• Tunnel and Underground Space
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• v.18 no.4
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• pp.300-311
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• 2008

In this study, scaled model tests were performed to investigate the stability of three parallel tunnels. Seven types of test models which had respectively different pillar widths, tunnel sectional shapes, support conditions and ground conditions were experimented, where crack initiating pressures and deformation behaviors around tunnels were investigated. In order to evaluate the effect of pillar widths on stability, various models were experimented. As results, the models with shallower pillar widths proved to be unstable because of lower crack initiating pressures and more tunnel convergences than the models with thicker pillar widths. In order to find the effect of tunnel sectional shape on stability, the models with arched, semi-arched and rectangular tunnels were experimented. Among them rectangular tunnel model was the most unstable, where the arched tunnel model with small radius of roof curvature was more stable than semi-arched one. The model with rockbolt showed higher crack initiating pressure and less roof lowering than the unsupported model. The deformation behaviors of tunnels in the anisotropic ground model were quite different from those in the isotropic ground model. Futhermore, the results of FLAC analysis were qualitatively coincident with the experimental results.

• The Journal of the Acoustical Society of Korea
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• v.31 no.3
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• pp.115-128
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• 2012

This paper investigates the effects of diffuser on the acoustical parameters in music hall with consideration of the result of scattering coefficient measurement. A scale model hall of 600 seats with orchestra shell was used for experiments. The materials of 1:50 scale model was chosen through absorption coefficient measurement based on ISO 354. The model was matched to the computer simulation model in terms of reverberation time. In order to evaluate the effect of diffuser location, the measurements were accomplished with and without diffusers according to 7 configurations by diffuser-installed region; sidewall, balcony front, ceiling and so on. The following acoustical parameters were extracted from each measurement case; Reverberation time (RT), Early decay time (EDT), Clarity (C80), Center time (Ts), Sound strength (G) and Temporal diffusion (TD) from the auto-correlation function (ACF) of impulse responses. As a result, the absorption power and diffusion power were increased with number of diffusers. Accordingly RT, EDT and G were decreased by diffuser and the redirection of reflections was occurred briskly. Averaged TD was 6.05 to 6.30 by measurement cases. RT was found to be the most related factor to diffusion power (R = 0.94). The correlation between TD and EDT was high (R = 0.73). In addition, the effects of diffuser-installed location were discussed in terms of acoustical parameter variation.