• Proceedings of the Korean Society of Computer Information Conference
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• 2014.07a
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• pp.249-252
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• 2014

본 논문에서는 IMU를 이용한 6자유도 모바일 로봇을 설계하고 성능을 평가해 보았다. IMU를 이용하여 로봇의 Roll과 Pitch 각을 측정하여 모바일 로봇의 이동경로 경사각을 측정하여 지면이 수평 일 때 모바일 로봇의 6바퀴 모두 항상 지면과 닿아 있는 상태를 유지한다. 또한 오르막과 내리막일 경우 로봇의 동역학에 의한 최소한의 에너지를 유지하여 이동이 가능하도록 하기위한 로봇의 제어기를 설계하고 그 성능을 평가해 보았다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.4
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• pp.109-118
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• 2005

A concrete shear wall system is commonly adopted in high-rise residential apartment buildings. In the construction stage, a rectangular opening is often made for the convenience of horizontal movement of workers, and construction materials and equipment. In the case of safety or stability assessment of a shear wall, the cutout part can be a critical factor. Finite element method is adopted to investigate the elastic stability behavior of the perforated unit shear wall. The key analysis parameters are the cutout location and its size. The effect of out-of-plane bending and horizontal shear are also examined in the stability analysis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.6
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• pp.84-91
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• 2019

For the goal of the proposal for optimum position of offset outrigger system, a structural schematic design of 70 stories building was carried out, using the general structure analysis program of MIDAS-Gen. In this research, the primary factors of this analysis research were the shear wall stiffness, the frame stiffness, the outrigger stiffness, the stiffness of column linked in outrigger system, etc. To achieve the aim of this study, we analyzed and studied the lateral displacement in top level, the force distribution of outrigger, the existing model of optimal outrigger location, and so on. This paper proposed the optimal position of offset outrigger system. Furthermore it is considered that the study results can be useful in getting the structure engineering data for seeking the optimal position of offset outrigger in the tall building.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.2
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• pp.22-32
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• 2015

This study intended to analyze an influence of the structure elements on the optimal location for one-outrigger system in tall building by using MIDAS-Gen. In this investigation, the analysis parameters were the outrigger position and the stiffness of main structure elements such as shear walls, outrigger systems, exterior columns connected in outrigger system and frames not to be connected in outrigger system. For the objective of finding out the optimal location for one-outrigger system in high-rise building, we studied the lateral displacement in top level of 80 stories building. The results of this study indicated that the outrigger location and the stiffness of main structure elements such as shear walls, outrigger systems, exterior columns connected in outrigger system and frames not to be connected in outrigger system had an influence on the optimal location of one-outrigger system. In addition, it is showed that the research results can be very useful in obtaining the structure design data for looking for the optimal location of one-outrigger system in high-rise building.

• Journal of the Korean Geotechnical Society
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• v.18 no.2
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• pp.87-96
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• 2002

The strain holding test(SHT) or the sell-boring pressuremeter test(SBPT) has been effectively utilized to determine the horizontal coefficient of consolidation$(c_h)$ of clayey soils. However, a commonly used procedure proposed by Clarke et al.(1979) can lead to an erroneous estimation of $(c_h)$ because of its simplified assumptions. This paper deals with numerical analyses based on realistic test conditions of the generally accepted testing procedure, and .using the most commonly used type of pressuremeter. The effects of pressuremeter geometry, partial drainage during cavity expansion, and the cavity strain level for the holding test are investigated with the radial distributions of the initial excess pore pressure and their dissipation rate. Based on the results of the numerical analyses, the curve of the time factor for the 50% degree of consolidation($T_{50}$) needed to estimate $(c_h)$ is proposed. Comparisons are made between $(c_h)$ values estimated from the SHT or the SBPT and those obtained from other in situ and laboratory tests performed at two sites in Korea. These results suggest the improved capability of the $T_{50}$ curve proposed herein.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.3 no.3
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• pp.87-94
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• 1983

The successful oil storage in the underground cavern is dependent on how to keep the water-tightness around the cavern by the groundwater. If the water-tightness is not secured, gas bubles will leak out and oil migrate to the adjacent empty cavern. An electrical analogy method was employed in studying the influences of the position of horizontal and vertical water curtains, the head of water curtain and the intervals of the cavern spacings and boreholes on the gas leakage and the oil migration into the adjacent empty cavern. The result shows that if the cavern spacing is narrow, the vertical water curtain should be established and if the cavern spacing is more than twice the cavern height, its establishment is not necessary. All the detailed factors required to prevent the oil migration are shown on graphs.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.6
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• pp.40-49
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• 2013

This study purposed to investigate the optimal outrigger location in tall building with cap truss after a structural schematic design of 80 stories building was performed by using MIDAS-Gen. In this paper, the main parameters of structural analysis were the outrigger location and stiffness of main structural elements (outrigger, exterior column, shear wall etc). In order to search the optimal outrigger position in high-rise building with cap truss, we analysed and examined the lateral displacement of top floor which is one of the very important considering factors of tall building structural design. The paper results indicated that the outrigger location and the stiffness of main structural elements such as outrigger, exterior column and shear wall had an effect on the optimal outrigger location. And it is verified that the study results provided the basic engineering data for fixing the most optimal outrigger location for minimizing the lateral displacement of tall building.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.6
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• pp.205-214
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• 2010

Masonry structures have been used throughout the world for the construction of residential buildings. However, from a structural point of view, the masonry material is characterized by a very low tensile strength. Moreover, the bearing and shear capacity of masonry walls have been found to be vulnerable to earthquakes. In this study, to improve the seismic performance of masonry walls, hexagonal blocks were developed and six masonry walls made with hexagonal block were tested to failure under reversed cyclic lateral loading. This paper focuses on an experimental investigation of different types of wall with hexagonal blocks, i.e. walls with different hexagonal blocks and with different reinforcing bar arrangements, subjected to applied cyclic loads. The cracking, damage patterns and hysteretic feature were evaluated. Results from the hexagonal masonry wall were shown more damage reduction and less brittle failure in comparison to the existing rectangular masonry walls.

• The Journal of Korean Institute of Information Technology
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• v.16 no.12
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• pp.49-56
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• 2018

As the era of the 4th industrial revolution comes, there is a growing interest in the use of UAVs. While various technologies are being developed using drones, controlling flight of drones is the most basic. Hovering control is essential in order to enable autonomous flight, especially during flight control of drones. In this paper, we design drones based on ATmega2560, Sonar, Optical Flow, and acceleration / gyro 6 axis sensor for drones hovering control, and developed horizontal control, altitude control, position tracking and fixed algorithm based on PID control. In this research, in order to measure the objective result of the drone, keeping the altitude immediately after the drone takes off according to the time, measure the movement value until the position is fixed and stable hovering is maintained and compared analyzed. Experimental results show that the drones can stably hover within 4cm horizontal and 2cm vertical from 50cm above the reference coordinates.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.2
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• pp.99-106
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• 2019

A wall-frame structure resists horizontal load by the interaction between the flexural mode of the shear wall and the shear mode of the frame, which implies that the frame deflects only by reverse bending of the columns and girders, and that the columns are axially rigid. However, as the height of frame increases the shear mode of frame changes to flexural mode, which is due to the extension and shortening of the columns. An approximate hand method for estimating horizontal deflection and member forces in high-rise shear wall-frame structures subjected to horizontal loading is presented. The method is developed from the continuous medium theory for coupled walls and expressed in non-dimensional structural parameters. It accounts for bending deformations in all individual members as well as axial deformations in the columns. The deformations calculated from the presented approximate method and matrix analysis by computer program are compared. The presented approximate method is more accurate for the taller structures.