• International Journal of High-Rise Buildings
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• v.3 no.2
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• pp.89-98
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• 2014

Employing tilted forms in tall buildings is a relatively new architectural phenomenon, as are the cases with the Gate of Europe Towers in Madrid and the Veer Towers in Las Vegas. This paper studies structural system design options for tilted tall buildings and their performances. Tilted tall buildings are designed with various structural systems, such as braced tubes, diagrids and outrigger systems, and their structural performances are studied. Structural design of today's tall buildings built with higher strength materials is generally governed by lateral stiffness. Tilted towers are deformed laterally not only by lateral loads but also by dead and live loads due to their eccentricity. The impact of tilting tall buildings on the gravity and lateral load resisting systems is studied. Comparative evaluation of structural systems for tilted tall buildings is presented.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.65-68
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• 2004

In the seismical capacity evaluation for RC structure wall-slab joint is very important factor. Because lateral load is resistance element and gravity load resistance element are acted mutually in the wall-slab joint. In this paper, to improve the seismic capacity of the wall-slab joint in the existing wall type apartments experiment which improve and retrofit a seismic capacity by unequal angle bracing and carbon sheet attachment are carried out. These methods are also economic and simple in mitigating seismic hazard, improve earthquake-resistance performance, and reduce risk level of building occupants. From the experimental results, the change of strength, degration of stiffness, and energy dissipation are evaluated. It can be concluded that these methods are effective in improving the seismic performance.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.911-914
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• 1993

This paper makes a trial to build the model of car-following in the state of starting to stable driving on the basic of driver's knowledge that is easily characterized by linguistical cognition. There are three main steps in building the model. Firstly, each driver's rule of three testees is studied in linguistical experssion by the interview and questionary surveys that are repeated once a day for ten days. Secondly, quantification of the linguistical expression is investigated by driving experiments that includes the questionary survey to the testee in the test vehicle, and the membership functions of variables of rule are obtained. Thirdly, implicaton and composition of fuzzy inference is made by Max-Min Methods and defuzzification by gravity method. It can be said that the proposed model of car-following based on driver's knowledge is practically allpicable to the estimation of drivering of car-following on trunk roads in urban area.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.235-237
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• 2003

GIS became increasingly important in information-oriented society as social indirect capital and many GIS data are developed. To use these data effectively standard format that enables easy to transport and store is needed. For this purpose, OGC developed GML based on XML as web standard format of geographical information. In this study, web based mapping with respect to digital geologic map and gravity anomaly map was accomplished using GML. While, styling methods were implemented in XSLT to make the visualizing suitable for the character of each layer, so it is possible to make dynamic maps in the SVG. GML-base map produced in this study can be transferred and represented without loss of the meaning and degrading on the web.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.305-312
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• 1999

A four-story reinforced concrete frame building model is designed for the gravity loads. only Static nonlinear pushover analyses are performed in two orthogonal horizontal directions. The overall capacity curves are converted into ADRS spectra and compared with demand spectra. At several points the deformed shape moment and shear distribution are calculated. It is observed that the seismic capacity may not meet the design requirements in soft soil condition and may collapse in MCE. It is concluded that limited but adequate amount of ductility need be provided in the seismic design in low to moderate seismicity regions.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.03a
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• pp.302-310
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• 2003

Cracking of slabs will be caused by applied load and volume changes during the life of a structure and thus it reduces flexural stiffness of slabs. The effect of slab cracking must be considered for appropriate modeling of the flexural stiffness for frame members used in structural analysis. Analytical and experimental study was undertaken to estimate the stiffness reduction of slabs. In the analytical approach, the trend of slab stiffness reduction related to gravity and lateral loads is found and the stiffness reduction factor ranged from a half to a quarter in ACI building code is reasonable when defining range. Analyzing results of the test by Hwang and Moehle for 0.5% drift show that the differences of rotational stiffness on the connection types is found and good results of lateral stiffness using the value of one-third is obtained.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2006.03a
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• pp.168-179
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• 2006

This paper summarizes full-scale test results on CFT column-to-flat plate connections subjected to gravity loading. CFT construction has gained wide acceptance in a relatively short time in domestic building construction practice due to its various structural and construction advantages. However, efficient details for CFT column to flat plate connections have not been proposed yet. Based on the strategies that maximize economical field construction, several connecting schemes were proposed and tested. Test results showed that the proposed connections can exhibit punching shear strength and connection stiffness exceeding those of R/C flat plate counterparts. A semi-analytical procedure is presented to model the behavior of CFT column-to-flat plate connections. The five parameters to model elastic to post-punching catenary action range are calibrated based on the limited test data of this study. The application of the proposed modeling procedure to progressive collapse prevention design is also illustrated.

• ETRI Journal
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• v.43 no.4
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• pp.594-602
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• 2021

Recently, quantitative and repetitive inspections of the old urban area were conducted because many structures exceed their designed lifetime. The health of a building can be validated from the condition of the outer wall, while the slant angle of the wall widely serves as an indicator of urban regeneration projects. Mostly, the inspector directly measures the inclination of the wall or partially uses 3D point measurements using a static light detection and ranging (LiDAR). These approaches are costly, time-consuming, and only limited space can be measured. Therefore, we propose a mobile mapping system and automatic slant map generation algorithm, configured to capture urban environments online. Additionally, we use the LiDAR-inertial mapping algorithm to construct raw point clouds with gravity information. The proposed method extracts walls from raw point clouds and measures the slant angle of walls accurately. The generated slant angle map is evaluated in indoor and outdoor environments, and the accuracy is compared with real tiltmeter measurements.

• Journal of the Korean Wood Science and Technology
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• v.36 no.1
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• pp.54-60
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• 2008

Sound absorption coefficients of oak (Quercus mongolica) wood and oak mushroom bed log were measured by the two microphone transfer function method and anatomical features of oak mushroom bed log examined by stereo scope and SEM observations. The sound absorption coefficients of oak mushroom bed log seemed to be higher than those of normal oak wood specimen over all estimated frequency range. Especially, in the frequency range of 2 to 6 kHz, they were about 2~3 times higher than those of normal wood specimen. Due to fungi degradation, the specific gravity of oak mushroom bed log decreased about 70% than that of normal wood. For oak mushroom bed log, abundant pores occurred on the radial, tangential and cross sectional surface and it was considered that the pores behaved as a sound absorbing pore.

• Journal of the Korea Institute of Building Construction
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• v.13 no.5
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• pp.482-490
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• 2013

Although the flat plate system is an efficient structural type due to the simplicity of its construction, the low story height, and the various plan design, the slab-column connections are vulnerable to punching shear failure from gravity load and eccentric shear failure from lateral load. To prevent the structure collapse, various construction methods of slab-column connection reinforcement are developed but none of these satisfies all of structural performance, economics, and constructability. This paper presents the reinforcement of slab-column connection with lattice bars. The structural performance is confirmed with the interior slab-column connection tests subjected to cyclic loading, and the economic feasibility is demonstrated from the structural design under the same condition with lattice bars, stud rails, and stirrups.