• Proceedings of the Korea Concrete Institute Conference
• /
• 1997.10a
• /
• pp.351-356
• /
• 1997

With the aid of advanced structural engineering, the construction of infrastructures has been recently accelerating to keep up with rapid economic growth. Construction activities and operation of transportation facilities cause civil petitions associated with vibration-induced damages or nuisances. As part of the decrease of vibration induced damage, the objective of this study is to develop vibration-controlled concrete with vibration-reduced materials, which can be recycled from obsolete materials, such as aged tires, plastics and etc. Appropriate mix proportion has been used for making 10 reinforced concrete panels with vibration-reduced materials, which have been tested to investigate on vibration reduction capability, based on the time and frequency domain analysis, and vibration velocity level analysis. Vibration-reduced mixtures are latex, styrofoam, rubber powder and plastic resin, which have been determined to by reduce vibration.

• Journal of Korean Society of Steel Construction
• /
• v.8 no.4 s.29
• /
• pp.77-84
• /
• 1996

The structural members under seismic loading actually show inelastic behavior, so the inelastic responses should be calculated for the seismic design of structures or estimating the structural damage level. Although direct time history analysis may calculate the exact dynamic nonlinear responses for given ground motions, this approach involves a high computational cost and long period. Therefore, it should be developed the approach to estimate nonlinear responses for the practical purpose. The artificial earthquake accelerograms were generated to obtain the smoothed responses spectra, and the samples of generated accelerogram for each seismic event was used to examine average nonlinear response spectra. The stabilized response spectra for each earthquake event was used to evaluate the effects of various yield strength ratios, damping values and nonlinear hysteretic models. The approach, which can simply predict the nonlinear seismic responses of structures, was shown in this study.

• Proceedings of the KIEE Conference
• /
• 1990.07a
• /
• pp.55-59
• /
• 1990

This study presents new algorithm for generating octree by volume intersection with pseudo-octrees which are constructed for each orthogonal face views in order to represent 3D objects exactly. In this algorithm, optimal quadtree is constructed for depth images in which distance information is represented in gray level, and then pseudo-octrees are constructed by using optimal quadtree in each orthogonal face view. It is shown that 3D object with concave parts can be reconstructed exactly by our suggested algorithm, and that memory space and tree construction time are also reduced compared with other algorithms.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.05a
• /
• pp.1252-1255
• /
• 2006

The government has enforced Housing Performance Grade Indication System (Article 21, Paragraph 2 of Housing Act) starting January 2006 for the purpose of giving users in hope of toying an apartment opportunities to select housing based on personal preferences by providing information on housing performance at the time of tenant recruitment announcement as well as securing desirable environment (comfort) by encouraging construction companies to build housing of the indicated performance level. The acoustic performance indication items include three items such as floor impact isolation performance(light weight impact sound, heavy weight impact sound), bathroom noise and insulation performance of boundary walls between households. This paper explains the background, the basis of creation and evaluation method focused on the acoustic environment performance helping for the developer of technique and a staff in charge of construction business who cope with this system.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2004.05b
• /
• pp.458-462
• /
• 2004

This study is to trace the change of stream shape using the past series of aerial photographs and compare the land use changes of inland along the stream. For the Gyeong-an national stream, aerial photographs of 1966, 1981 and 2000 was selected and ortho photograph was made with RMSE of 1.05, 0.54, 0.72 pixels, respectively. As apparent changes of the stream, the consolidated reaches of stream with levee construction were straightened and their stream width widened. Especially the stream width of inlet part of Paldang lake was widened almost twice because of the rise of water level by dam construction in 1974.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.14 no.7
• /
• pp.2862-2878
• /
• 2020

Data Security is the most challenging area in Internet communication, where most of the secret sharing schemes are proposed for binary images. But still it lacks in providing security for data communication, especially in image transmission. Traditional visual cryptography scheme generate meaningless diwies and the reconstruction phase leads to quality degradation over the secret image. In this work, an intelligent two dimensional secret share construction scheme is proposed. A secret image is expanded into n diwies with the choice of scheme selection. By Stacking all the qualified diwies to revert the secret image without content loss and less than s^* - 1 shares could not reveal any information about the secret image. The experimental results emphasize that the proposed secret share scheme is highly secured for image transmission.

• Korean Journal of Geomatics
• /
• v.1 no.1
• /
• pp.21-26
• /
• 2001

Total Station (TS) is currently widespread and used in many fields of surveying projects. However, its application functions are not perfectly understood and so insufficiently used. One of them is indirect leveling method using TS. Because we can reach a considerable accuracy level with this method, it is gradually expanding for public surveying works such as construction of roads, airports and harbors. This paper gives results of an experiment to increase accuracy of indirect leveling by TS without direct leveling, which is more comfortable and quick to determine elevation.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2006.05a
• /
• pp.27-30
• /
• 2006

This study investigated influence of organic fiber type and contents on engineering properties of concrete. Test showed that increase of fiber contents decreased fluidity of fresh concrete and it was even worse in concrete adding cellulose fiber. It is decided that concrete containing more than proper level of fiber should be considered. In addition, concrete adding more fiber, nylon and cellulose, resulted in increase of air content but it was satisfied in aimed value. Bleeding capacity of concrete containing more fiber significantly declined and setting time of that was also slightly retarded. For the properties of strength, both compressive and tensile strength of fiber containing concrete were indicated at similar value to control concrete. However, it is clear that if those concrete containing fiber revised the value of increased air contents at fresh state, the strength value of that would be slightly increased.

• Journal of the Korea Institute of Building Construction
• /
• v.13 no.1
• /
• pp.10-19
• /
• 2013

Companies want universities to produce graduates with creativity and problem-solving skills, and for this reason universities have extended engineering design education, including in the field of architectural engineering. This paper investigates an engineering design class in the Department of Architectural Engineering, J University. The class was taught in 2010 and 2011using an Action Learning (AL) teaching-learning strategy. The students responded that the level of participation and satisfaction was high in the Action Learning classes, and role allocation or responsibility and communication of the project teams were very effective. But it was also found that as Action Learning is such a new method for students of engineering design, an orientation session that describes what to do and what to prepare should be given before the class starts.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2018.05a
• /
• pp.245-246
• /
• 2018

This paper is a multipurpose functional synthetic resin formwork which can replace existing euro form. We tried to improve the disadvantages such as work noise, stenosis, recyclability, and workability of Euroform system. As a result of the test, Euroform showed an average of 106.7dB and synthetic resin formwork showed an average of 100.4dB. Therefore, it is considered that the synthetic resin formwork has a great effect of noise reduction compared to the euro form.