• 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.

• Journal of the Korean Solar Energy Society
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• v.29 no.2
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• pp.47-54
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• 2009

The amount of incident rays over inclination according to direction has been widely utilized as important data m installing solar thermal systems. To optimize the incident solar radiation, the slope, that is the angle between the plane surface in question and the horizontal, and the solar azimuth angles are needed for these solar thermal systems. This is because the performance of the solar thermal systems in much affected by angle and direction of incident rays. Recognizing that factors mentioned above are of importance, actual experiment on the moving route of the sun have been performed in this research to obtain the angle of inclination with which the maximum incident rays can be absorbed. After all, the standard for designing highly optimized solar thermal systems will be provided for designers and employees working in the solar collector related industries.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.5
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• pp.207-216
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• 2018

This research compared and analyzed safety ratio of slope with Talren97 and SoilWorks based on limit equilibrium analysis and Midas GTS based on finite element analysis. For the analysis variables, there are slope height, berm condition, soil parameter, groundwater level, slope inclination. All of slope stability analysis were performed by dividing into dry season and rainy season. As the result of the analysis of Talren97 and SoilWorks based on same theory, safety ratio of slope shows same value, so there was no difference between the programs. In comparison with limit equilibrium analysis, the result of finite element analysis showed somewhat high ratio of safety and it was higher by about 2.4% averagely. The difference between the result of limit equilibrium analysis and that of finite element analysis is in the range which can ignored in practical work.

• The Journal of Engineering Geology
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• v.32 no.2
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• pp.209-219
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• 2022

To experimentally investigate the variation of soil characteristics in slope during rainfall and the shape of slope failure, the model test was performed using soil box and artificial rainfall simulator. The model test of slope formed by the homogenous sand was performed, and the saturation pattern in the model slope due to rainfall infiltration was observed. The slope model with the inclination of 35° was set up on the slope of 30°, and the rainfall intensity of 50 mm/hr was applied in the test. The soil depth of 35 cm was selected by considering the size of soil box, and the TDR (time domain reflectometry) sensors were installed at various depths to investigate the change of soil characteristics with time. As the result of model test, the slope model during rainfall was saturated from the soil surface to the subsurface, and from the toe part to the crest part due to rainfall infiltration. That is, the toe part of slope was firstly saturated by rainfall infiltration, and then due to continuous rainfall the saturation range was enlarged from the toe part to the crest part in the slope model. The failure of slope model was started at the toe part of slope and then enlarged to the crest part, which is called as the retrogressive failure. At the end of slope failure, the collapsed area increased rapidly. Also, the mode of slope failure was rotational. Meanwhile, the slope failure was occurred when the matric suction in the slope was reached to the air entry value (AEV) estimated in soil-water characteristic curve (SWCC).

• Korean Journal of Applied Biomechanics
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• v.27 no.2
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• pp.91-97
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• 2017

Objective: To investigate rotation movement of segment for performing each position and its effect on knee/hip angulation, COM inclination, and edging angle changes. Method: Twelve Alpine skiers (age: $25.8{\pm}4.8years$, height: $173.8{\pm}5.9cm$, weight: $71.4{\pm}7.4kg$, length of career: $9.9{\pm}4.6years$) participated in this study. Each skier was asked to perform counter-rotation, neutral, and rotation positions. Results: Shank and thigh were less rotated in the counter-rotation position than in other positions, whereas the trunk and pelvis were more counter-rotated (p<.05). Hip angulation, COM inclination, and edging angle were significantly greater in the counter-rotation position than in other positions (p<.05). Conclusion: Our finding proved that the counter-rotation position increases hip angulation, COM inclination, and edging angle. Consequently, we suggest that skiers should perform counter-rotation of the trunk and pelvis relative to the ski direction in the vertical axis for the counter-rotation position. Further analysis will continue to investigate the effects of the counter-rotation position in real ski slope with kinetic analysis.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.153-158
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• 2008

In this study, piping and slope stabilities of sea dike were analyzed through pore pressure-mechanic coupled analysis. Through decrement of sea dike inclination, to confirmed cross-section reduction possibility of multi-function sea dike.

• The Journal of Engineering Geology
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• v.25 no.2
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• pp.189-199
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• 2015

Our country's leading granite weathered soil of the ground slope failures that occur in cutting slope most cases, it does not require in-depth to the shear strength most of the surface layer is affected by weathering (1~2 m) at a shallow depth close to the ground, it is important to identify the reliability. Based on the result obtained in actual field investigation, the field slope type was classified by each type of wedge slope, Infinite slope, finite slope -I and finite slope -II, and the slope stability was examined respectively. In addition, using the numerical analysis results, the relationship between the slope inclination angle and safety factor was analyzed and it tried to offer basic data to which the stability in the field slope was able to be estimated by analyzing the safety factor change of the slope according to the slope type. In this study, classified into four types of natural slope, safety factor estimation method by slope types is proposed through the numerical analysis. However, some limit exists in generalizing in this research because it does not test various case studies. Therefore, the case study of a wide range of various sypes to assess the safety of various types slope can be made, accommodate a wide range of field conditions reasonable risk evaluation criteria may be derived.

• Journal of the Korean Geosynthetics Society
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• v.17 no.1
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• pp.85-93
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• 2018

A existing standard design section of transitional zone between bridge and earthwork section in high speed railway should be designed to gradually change support stiffness from bridge abutment to backfill side that were placed on cemented stabilized gravel, general gravel, soil materials. The larger the backfill slope of the general gravel and soil was more structurally stable, but there is no clear reason about them. In this study, it was compared with settlement and bearing capacity of backfill area in currently design and alternating backfill slope section using large centrifuge tester. As the experimental results, it was showed that the 1:2 slope and 1:1.5 slope have almost similar bearing capacity behavior under the load stage as railway loading level.

• The Research Journal of the Costume Culture
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• v.26 no.1
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• pp.95-108
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• 2018

This study analyzed the body shape of the body of 17~19 years old female students using the SPSS 20.0 statistical program according to the 7th Korea Human Body Survey. Factor analysis was based on six factors including body size, body height, shoulder length, and width, upper body length, hip length, and shoulder inclination related factors. Through this cluster analysis, the body shape of late adolescent female student was classified into four types. Body type 1 was the highest body height factor, and the upper body length and the hip length factor were lower. It was analyzed as 'Long leg in the body'. Body type 2 is the 'narrow shoulder skinny type' with high hip and shoulder slope factors and low body size, body height, shoulder length, and width factor. Body type 3 showed body size, shoulder length, height and hip length factor, and body height factor was rather low 'low hip obese body shape'. Body type 4 was analyzed as 'lower shoulder long upper body type' with higher upper body length factor and lower body size and shoulder slope factor. It is thought that when the pattern is made, it is possible to produce excellent patterns by fitting the dimensions of the body, as well as the dimensions of the shoulder width, the slope, and the hip length.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.527-534
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• 2000

136 cut slopes which extends from Namyangju to Chunchon city along the 46th national highway were investigated to analyze the influence factors affecting slope instability. Geologic and geotechnical conditions were examined and the detailed investigation were carried out for fifty five failed slopes. failure mode (wedge failure, planar failure, circular failure, sheet eroison and rock falls) are examined with respect to slope inclination, rock type, weathering grade and discontinuity patterns. It is suggested that the failure modes and their dimensions have relations to the morphology and geologic conditions of the slopes. Wedge failure has highest is the most frequent failure mode and falls, sheet erosions, planar failures and circular in descending order of failure percentage. Wedge failure is most dominant failure type over all lithology except quartzite formation. In slopes of well foliated and banded gneiss, failure ratio of wedge is up to 50% ca. Failure ratio(number of rock fall/number of total failure) of rock fall increases with increase fo slope inclinations and decrease of weathering grade. Dimension analyses of failed slopes shows wedge and circular failure has higher value of D/L and D/H than planar failure and sheet erosion.