• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.10a
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• pp.124-131
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• 2000

Numerical analysis of slop stability is carried out using seismic intensity, modified seismic intensity, and response seismic coefficient methods. It is found by comparing each of method that minimum safety factor precedes the required safety factor. It is also proved during analysis that most conservative method is the earthquake response analysis method, next is the response seismic coefficient method, and last one is the seismic intensity method. Usually, seismic intensity method is applied in analysis of slop stability. However, in view of safety factor, modified seismic intensity method is more conservative than seismic intensity method. Also modified seismic intensity method is appropriate when height of structure analyzed is high enough.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.11
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• pp.1665-1674
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• 2013

In this paper, we propose a genetic algorithm(GA) based locomotion method of a quadruped robot with waist joint, which makes a quadruped robot walk on the slop efficiently. In the proposed method, we first derive the kinematic model of a quadruped robot with waist joint and then set the gene and the fitness function for GA. In addition, we determine the best attitude for a quadruped robot and the landing point of a foot in the walk space, which has the optimal energy stability margin(ESM). Finally, we verify the effectiveness of the proposed method by comparing with the performance of the previous method through the computer simulations.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.2
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• pp.26-35
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• 2001

We are, now in the 21st century, that environmental preservation and the campaign for bio-diversity protection are very important issues the government must deal with as nation's main policy. To make road and building construction, housing land service, construction of golf fields, and various development works, we have made artificial topographical alterations and as a result, the cut-slop has been increased. However, without the proper study and clear planning, revegetation for the stability of the cut-slop has worked out. These efforts now are causing derangement of an ecosystem and spoiling the nature without considering for ecological adaptation. Therefore, we are going to find out the Revegetation Method to Cut-Slopes considering both the ecological adaptation and harmony with the nature.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.759-763
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• 2010

Currently available evaluation checklists are developed for specific purposed using different parameters and items determined by different weighting factors. Those items with different weighting are sometimes said that they are based on the engineering judgement and leap of faith and, therefore, there is a limitation to adapt those checklists for slope-stability evaluation in the field. This study reviews factors affecting Rock-slope stability, analyze the relationship between those factors and slope failures using artificial neural network, and proposed a slope-stability evaluation model for adequate weighting for the factors.

• Journal of the Korean Society of Safety
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• v.24 no.2
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• pp.48-54
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• 2009

Structures to support against slop failures or resist earth pressure like masonry retaining walls or retaining walls have continued to advance and evolve to new eco-friendly, easy-to-construct, crib retaining walls with varied forms and construction methods, meeting the needs of the times. Researches until now, however, have focused on the analyses of site displacement or stability of the whole site including structures like retaining walls, and thus, researches on rational design or method for stability analysis are lacking. Therefore, this study was conducted on a number of stability analyses, such as the visual power line or stability on sliding, being presented for bin walls, which enable vegetation to grow and were developed and applied in varied forms, meeting the development demands for eco-friendly retaining wall structures. This study compared the results of stability analyses, determined their feasibility, and evaluated their stability according to the height and facade slope of retaining walls. According to the results of this study, traditional masonry retaining wall analysis showed rather conservative stability evaluation results in the stability evaluation of bin walls, and the method using the visual power line seems to be objective because it produced similar results to the stability evaluation method on sliding or turnover.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.958-967
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• 2004

This paper deal with cause and analysis about case of collapsed reinforced-soil retaining wall. The analysis of the cause was carried through experimentation, slop stability analysis and literature study. The experimentation treated the large direct shear test, the hydraulic conductivity test and the other basic test through backfill extracted from collapsed reinforced-soil retaining wall. The ultimate tensile strength was established by rib tensile strength test of geogrid. The analysis of internal and external stability of reinforced-soil retaining wall was performed on the basis of parameters. The result of analysis, reinforced-soil retaining wall and the slope at the dry season are stable. However, the factors that fine-grained soil at hydrometer test exceed the standard of the design, rainfall duration is too long at the time of collapse and monthly pricipitation is heavy are cause of the collapse.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.10a
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• pp.108-115
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• 2000

Numerical analysis of slop stability is presented using seismic displacement, response seismic coefficient, and earthquake response analysis methods. In seismic displacement and response seismic coefficient methods, horizontal static seismic force is considered as 0.2g while vertical static seismic force is not considered in analysis. For earthquake response analysis Hahinoha-wave is applied, It is found from result that analysis using response seismic coefficient method is much more conservative than that using seismic displacement method Also, analysis result using earthquake response analysis method is somewhat less conservative about 25% when compared with that using seismic displacement method.

• Journal of Korean Society of societal Security
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• v.1 no.2
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• pp.67-72
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• 2008

To confirm the stability of a cut slope in the road extension construction site, several investigations were carried out and countermeasures of slope was studied. This paper describes a study of design case of extra reinforcement on existing cut slope reinforced by preloading and piles in roads. To investigate the effect of stabilizing piles installed in a cut slope, an instrumentation system also designed, was. As a result that the stabilizing file and earth anchor are considered as the extra reinforcement, both stabilizing pile and earth anchor guarantee the stability of cut slope. However, stabilizing pile is selected in aspects of economy and continuity to the existing cut slop reinforcement including counterweight fill and stabilizing piles.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.5
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• pp.291-294
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• 2015

Recently, ZnO based oxide TFTs used in the flexible and transparent display devices are widely studied. To apply to OLED display switching devices, electrical performance and stability are important issues. In this study, to improve these electrical properties, we fabricated TFTs having Al doped Zinc Oxide (AZO) layer inserted between the gate insulator and ZnO layer. The AZO and ZnO layers are deposited by Atomic layer deposition (ALD) method. I-V transfer characteristics and stability of the suggested devices are investigated under the positive gate bias condition while the channel defects are also analyzed by the photoluminescence spectrum. The TFTs with AZO layer show lower threshold voltage ($V_{th}$) and superior sub-threshold slop. In the case of $V_{th}$ shift after positive gate bias stress, the stability is also better than that of ZnO channel TFTs. This improvement is thought to be caused by the reduced defect density in AZO/ZnO stack devices, which can be confirmed by the photoluminescence spectrum analysis results where the defect related deep level emission of AZO is lower than that of ZnO layer.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.11
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• pp.1164-1169
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• 2014

This paper proposes an angle estimation of Segway robot for the slop driving. Most of Segway robot was controlled by pose control of keeping robot's balance and motor control of driving. In motor control, we analyzed Segway robot kinetically and estimated an angle of inclination using the velocity that depends on input force. In pose control, also, we used PD controller and evaluated a stability of controller through MATLAB simulation. Assuming the robot keeps its balance stably using controller, we could linearize dynamics. We could obtain the result through the experiment which estimates an angle using the velocity of Segway robot that is derived from linearized dynamics.