• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.5B
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• pp.301-312
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• 2012

This study investigates the wave height distributions in front of a perforated wall generated by obliquely incident monochromatic waves through laboratory experiments conducted in a wave basin. Attention is paid to the difference or similarity between a plain wall and a perforated wall. And the investigation is focused on the chamber width and side wall effects of a perforated wall on the propagation characteristics of waves. The main results of this study show that the normalized wave height along a perforated wall is a significant difference compare to a plain wall cases. The side wall in the chamber suppresses the growth of the stem waves.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2343-2350
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• 2013

The wave height distributions in front of a vertically perforated wall structures for obliquely incident uni-directional irregular waves are mainly investigated by using 3D hydraulic experiments. The difference and similarity of wave propagation along the plain and perforated wall structures are investigated and particularly the effects of side walls in chamber and relative chamber width are analyzed. This study shows that the wave height distribution patterns for normalized wave heights in front of structure is significantly different between the plain and perforated wall structures, and the side wall in the chamber suppresses the growth of waves.

• Journal of the Korean Institute of Educational Facilities
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• v.18 no.5
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• pp.3-11
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• 2011

In this study, the effect of treating 1-dimensional diffusers on the classroom acoustics was investigated to determine if the diffuser are beneficial for performing the preferred acoustical conditions for speech. A 1/10 scale model of a classroom was used to measure the acoustical parameters, T30, $C_{50}$, STI and SNR in that room. The room acoustical conditions were varied by treating diffusers either on the front or side walls of the classroom. When the diffusers were treated on the side walls around the student's areas, a shorter reverberation time at low frequencies was obtained and resulted in performing uniform reverberation times across the frequency bands. The $C_{50}$ values at mid- and high-frequencies were increased by treating the diffusers either on front or side wall surfaces. The highest STI and SNR values were obtained when the diffuser was treated on the front wall around the teacher's areas. It is found that diffusers are beneficial to increase the intelligibility of speech for the rear seats of the rooms.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.293-296
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• 2009

In roll forming process, a sheet metal is continuously progressively formed into a product with required cross-section and longitudinal shape, such as a circular tube with required diameter, wall-thickness and straightness, by passing through a series of forming rolls in arranged in tandem. In recent years, that process is often applied to the bumper rail in the automotive industries. In this study, a optimal front side member manufacturing technology, model deign and proper roll-pass sequences can be suggested by forming number of roll-pass and bending angle. And also effects of the process parameters on the final shape formed by roll forming defects were evaluated.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.1
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• pp.47-52
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• 2004

3D microstructures with different side-wall angles and different scales are fabricated by both methods of inclined exposure and rear-side exposure at each of selected areas on a same substrate. Conventional methods of inclined exposure are used to make side-walls with a same inclined angle on one substrate and to get a scale error due to front-side exposure through thick photoresist layer, But, by using the proposed method, we are able to fabricate 3D microstructures on a same substrate with various side-wall angles and accurate dimensions as the original design. In the rear-side exposure, UV exposure light reflects from the chromium mask pattern after passing through the thick photoresist layer, resulting in fabrication of well-defined, inclined 3D structures inside the thick photoresist layer.

• KIEAE Journal
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• v.15 no.3
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• pp.37-42
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• 2015

Purpose: Apartment is a typical residential type in Korea. In the past, apartment types were very monotonous. But today, the types of complex are changed because personal needs have been diversified and personalized. In order to meet those needs, construction companies are constructing various types of apartments. The more apartment types are diverse, the more the energy problems are taken place. So, the purpose of this study is to solve the problem of energy gap in the same complex through improving the thermal transmittance of wall. Method: Heating energy consumption of Building Energy Efficiency Rating System and heating energy usage of apartment show a similar trend on the graph. In order to identify the best position of heating energy consumption difference reduction, we change the building's U-value of front, back, side walls. Result: In the A complex, maximum and minimum heating energy consumption building's shapes are flat. the best efficiency is side U-value change and the worst is front change. In the E complex, maximum heating energy consumption building's shape is tower and minimum building shape is flat. Consequently, the front and back wall performance change was little effect to reduce energy gap, while the change of side wall's U-value show the great reduction between building's energy consumptions.

• International Journal of Precision Engineering and Manufacturing
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• v.3 no.3
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• pp.21-27
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• 2002

In this paper, a simple test rig of high-speed crash for the front members of vehicles was developed for the improvement of crashworthiness of vehicle's side rail. The cart hanging the specimen is accelerated up to 35 mph by the traction wire and by the force of freely dropping weight and 1:3 accelerating pulleys. The cart with shock absorbers travels on the rail roads, so it does not transfer any additional vibration to the specimen. In order to measure the energy absorbed by the specimen when it collapse to the wall and during it deform, the two strain gage type load cells are used at the wall place. The test rig rated good to test the specimen like a side rail of vehicle as developing the vehicle's structures in the early design stage.

• Journal of the Korean housing association
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• v.26 no.6
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• pp.139-146
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• 2015

In this study, the plane type of main building relics of unified Silla period house site which excavated in Gyeongju city after 1990s was classified and the architectural characteristic of them was investigated. The chronology of building relics in Silla capital city site was mostly known as 8-9th century, and by standard of column arrangement, the plane types of them could be classified as grid type, front veranda-grid type, outer column type. The outstanding characteristic of plane is wide span and open front veranda. In most relics the span were over 4 meters, and inner foundations for small post and strip foundation were found between columns. The front veranda added type buildings were composited of enclosed main room and open front veranda, and column arrangement of them dose not fall into line in most case. Thus it thought that the structures of enclosed main room and open front veranda were independent. The interior space of enclosed main room were divided two rooms by partition wall in some case. In this case, one room is enclosed by wall, and the other room has open front side. This plane is considered for the pleasant life in cold winter and hot summer.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2003.05a
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• pp.74-77
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• 2003

After the Enforcement of Price Deregulation of Apartment, Apartment house get down to originality goods, The Housing Market have reorganized the nucleus by a user, have demanding the development for discriminative unit plan. The purpose of this study is that before and after the Price Decontrol of Apartment take part a variety of unit plan, search for transformation factor and analyze into the tendency of the distinction plan of Housing Goods. Before and after the Price Decontrol of Apartment, Apartment unit have analyzed from 85 $m^2$ till 152 $m^2$ private area; ten corporations of civil construction' unit in Seoul and The national capital region supply apartment, will supply apartment. For selected examples, first, unit plan is normalized from the ratio of front to side wall, bay, a Room' organization and a kind of Room, number, and for examples of unit plan of apartment, the examples were analyzed with respect to change of a Room' organization and the number of a room and the ratio of front wall to side wall for item investigated. Finally, I search out course of transformation tendency of an apartment unit plan after Enforcement of Price Deregulation and analyzed a factor. The results of the study are follows, after Enforcement of Price Deregulation, unit plan of apartment lead to change lay out, to secure each family's privacy, to secure feeling for open hearted, tendency of flexibility.

• Journal of the Korean Professional Engineers Association
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• v.42 no.4
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• pp.55-61
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• 2009

Retaining wall is a structure to stabilize the land slope as vertical retaining wall have constructed to make efficiency use of downtown area. Recently to commune with nature and refine a apartment and structure, natural friendly relations for retaining walls are tried to construct. The surface of the concrete walls are weave in various figures and colours, and in some places plant a shrub. Laying a landscape stone which have disclose a plane nature one means keeping up the natural slope, constructively safely set a anchor in front side and rear side wall between the natural stone, plant shrub or ground coverings to give shape into a rock. Natural stone is exposed of surface and planting the gardening, to be a type of natural friendly relations however that will be recycled. The size of blasted nature stone which is irregular become more natural type of one.