• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.519-528
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• 2009

The effects of taping on the use of such measures for prevention have already been comprehensively described in the literature. However, few studies have analyzed ground reaction forces and postural stability with functional ankle instability subject during dynamic activities with ankle taping The purpose of this study was to identify the effects of ankle taping on ground reaction force and postural stability during jump landing. Fourteen players who has ankle instability were participated in this study. we used vicon and force platform. The application of taping who has ankle instability decreased DF and inversion angular velocity and peak vertical ground reaction force during landing. It also improved A-P cop, M-L cop in stability. The findings of this study support the use of taping as part of injury prevention for subject with functional ankle instability in clinical setting.

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.449-455
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• 2009

The purpose of this study was to analyze the kinetics variables of GRF by dtance type during forehand stroke. Eight high school tennis players, who have never been injured for last six months, in Busan were chosen for the study. They performed horizontal swing and vertical swing that it was done each five consecutive trial in the condition of square, semi-open and open stance. It was filmed by 6 video camera and used with 3-dimensional motion analyzer system and GRF system. The following kinetic variables were analyzed in relation to left leg and right leg GRF. The conclusion were as follow: 1. In square and semi-open stances, the horizontal ground reaction force was decreased at impact in left leg regardless of swing type, whereas open stance was increased at impact to the tiptoe in both legs. 2. In square and semi-open stances, the vertical ground reaction force was increased at impact in left leg regardless of swing types, whereas open stance was decreased at impact to vertical direction in both legs.

• Korean Journal of Applied Biomechanics
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• v.13 no.2
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• pp.123-137
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• 2003

This study is to present more effective starting skills through analysis of kinematic characteristics of starting motions in 300m Time Trials of Inline Skating. To achieve this goal, 6 athletes, 3 in the national team and 3 in business teams were chosen and their starting motions were examined with three-dimensional image analyses. The results of analyses in regard of positions and speed of the bodily center and angles, angular velocity, and linear velocity of articulations of lower limbs by sections of starting motions are as follows: In case of the central position, though it is effective to reduce the air resistance by lowering the upper part of the body maximumly, it is reasonable to accelerate by raising the upper part of the body to some degree for the running posture at the lower speed in the starting section. In the starting section, it is efficient to minimize the period of time in touching the ground. for this, it is necessary to train for taking motions without slippage while touching the ground. While 3 athletes in business teams kicked the ground as running right after the starting, the others in the national team slid on the ground. As the number of steps increased, the movable speed changed quickly. Thus the movable speed of athletes in the national team indicated big differences in two to three steps. If these factors are well supported, the push-away starting method might be better than the running starting method in terms of improvement of records.

• The Journal of Engineering Geology
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• v.24 no.2
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• pp.273-281
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• 2014

In most current seismic design codes, design earthquake ground motions are defined by a reference spectrum, based on bedrock and site amplification factors that quantify the geotechnical dynamic conditions. Earthquake engineering bedrock is the fundamental geotechnical formation where the seismic waves are attenuated without amplification. To better define bedrock in an earthquake engineering context, shear wave velocity ($V_S$ ) data obtained from in-situ seismic tests were examined for several rock strata in Korea; these data were categorized by borehole drilling investigations. The $V_S$ values for most soft rock data in Korea are > 750 m/s, which is the threshold $V_S$ value for identifying engineering bedrock from a strong motion station. Conversely, VS values are < 750 m/s for 60% of $V_S$ data in weathered rock in Korea. Thus, the soft (or harder) rock strata below the weathered rock layer in Korea can be regarded as earthquake engineering bedrock.

• Journal of Environmental Science International
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• v.14 no.1
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• pp.41-51
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• 2005

Using three-dimensional non-hydrostatical numerical model with one way double nesting technique, atmo­spheric circulation in the mountainous coastal region in summer was investigated from August 13 through 15, 1995. During the day, synoptic westerly wind blows over Mt. Mishrung in the west of a coastal city, Sokcho toward the East Sea, while simultaneously, easterly upslope wind combined with both valley wind from plain (coast) toward mountain and sea-breeze from sea toward inland coast blows toward the top of the mountain. Two different directional wind systems confront each other in the mid of eastern slope of the mountain and the upslope wind goes up to the height over 2 km, becoming an easterly return flow in the upper level over the sea and making sea-breeze front with two kinds of sea-breeze circulations of a small one in the coast and a large one in the open sea. Convective boundary layer is developed with a thickness of about 1km over the ground in the upwind side of the mountain in the west and a thickness of thermal internal boundary layer from the coast along the eastern slope of the mountain is only confined to less than 200 m. On the other hand, after sunset, no prohibition of upslope wind generated during the day and downward wind combined with mountain wind from mountain towardplain and land-breeze from land toward under nocturnal radiative cooling of the ground surfaces should intensify westerly downslope wind, resulting in the formation of wind storm. As the wind storm moving down along the eastern slop causes the development of internal gravity waves with hydraulic jump motion in the coast, bounding up toward the upper level of the coastal sea, atmospheric circulation with both onshore and offshore winds like sea-breeze circulation forms in the coastal sea within 70 km until midnight and after that, westerly wind prevails in the coast and open seas.

• 한국지구물리탐사학회:학술대회논문집
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• 2009.10a
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• pp.119-123
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• 2009

Gravity changes due to variations of groundwater level were measured at a ground water monitoring well, which is located at Kum-san, Korea, from November 2008 to September 2009 using Portable Earth Tide (PET) gravimeter. Groundwater level was monitored simultaneously with gravity observations. To extract gravity information from groundwater, we reduced gravity effect from atmospheric surface pressure, earth tides and its loading effect, polar motion and meter drift. In addition, in June 4, 2009, there was a pumping test at he observation well, and groundwater level and gravity variations were observed together successfully. Observation of gravity along with groundwater level is potentially useful for monitoring of aquifer water mass balance and water resources.

• Tunnel and Underground Space
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• v.25 no.3
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• pp.255-263
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• 2015

Explosive blasting is a very useful tool for mining and civil engineering applications. It, however, may cause severe environmental hazards on adjacent structures due to blasting impact. Blast engineers try to make optimum blast design to provide efficient performance and to minimize the environmental impact as well. It requires a pre-assessment of the impacts resulting from the blasting operation in design stage. One of the common procedures is to evaluate the proposed blast pattern through a series of test blasting in the field. Another approach is to evaluate the possible environmental effects using the numerical methods. There are a number of input parameters to be prepared for the numerical analysis. Some of them are well understood, while some are not. This paper presents some results of sensitivity analysis of the basic input parameters in numerical modelling of blasting problems so as to provide sound understanding of the parameters and some guidelines for input preparation.

• Journal of Advanced Navigation Technology
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• v.27 no.2
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• pp.155-161
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• 2023

Vertigo refers to a state in which awareness related to the location, posture, movement, etc. of a helicopter is insufficient in space. It is easy to fall into flight illusion when flying in dense fog or night flight, and even if it has a wide field of view, it can be caused by visual causes such as cloud shapes, wind conditions, conditions of ground objects, and sensory causes such as changes in air posture or gravitational acceleration. The design and program of the motion system are studied that applied a six-axis motion system to a conventional commercial flight simulator program for pilot training, depending on the specificity of helicopter flight training that requires perception and sensitivity. Using the motion-based helicopter simulator produced in this study to train pilots, it is expected to have a positive effect in prevent of vertigo, where high performance could not be confirmed in the previously used visual-based simulation training device.

• The Journal of Engineering Geology
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• v.17 no.4
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• pp.545-554
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• 2007

Landslides is mainly induced by a heavy rainfall, earthquake ground motion, and some other factors like soil mechanics, morphological-geological factors etc. Since the starting point of the failure seemed to be originated at a construction site in the study, it is meaningful to find out the relationship between the landslide and the construction. For this study, the slope failure factor was examined carefully to see that the original natural slope had vulnerability and that the complex ground had unstability changed by construction. A field survey was conducted on the original ground surface and filled-up ground. A laboratory test was also conducted to determine the geomechanical properties of soil samples. 2D and 3D limit equilibrium analysis with changing groundwater level were conducted at the failure depth using a seismic refraction survey. The result shows that the factor of safety is similar stability under all condition, but unstable under saturated condition.

• The Journal of Korean Physical Therapy
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• v.21 no.2
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• pp.87-95
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• 2009

Purpose: This study reports the basic reference data of the specific gait parameters for Korean normal adults. Methods: The basic gait parameters were extracted from 73 Adults (35 men and 38 women), 18 to 33 years of age, using a Vicon MX motion analysis system. The segment kinetics, such as joint moment and power, was analyzed at the hip, knee and ankle. Results: The motion patterns are typically associated with a specific phase of the gait cycle. The temporal-spatial gait parameters of Korean normal adults, such as cadence, walking speed, stride length, single support and double support, were similar to the other western reference data. The kinetic parameters of Korean normal adults, such as joint moments of force, joint mechanical power generation or absorption and ground reaction forces, were also similar to other western reference datasets. Conclusion: This study demonstrates that objective gait analysis can be used to document the gait patterns of normal healthy adults. The techniques of 3-dimensional temporal-spatial gait parameters and kinematic parameters analysis can provide a detailed biomechanical description of a normal and pathological gait.