• Water Engineering Research
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• v.1 no.4
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• pp.321-330
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• 2000

The grid-based KIneMatic wave STOrm Runoff Model(Kim, 1998; Kim, et al., 1998) which predicts temporal variation and spatial distribution of overland flow, subsurface flow and stream flow was evaluated at two watersheds. This model adopts the single overland flowpath algorithm and simulates surface and/or subsurface water depth at each cell by using water balance of hydrologic components. The model programmed by C-language uses ASCII-formatted map data supported by the irregular gridded map of the GRASS(Geographic Resources Analysis Support System) GIS and generates the spatial distribution maps of discharge, flow depth and soil moisture of the watershed.

• Korean Journal of Applied Biomechanics
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• v.13 no.2
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• pp.29-47
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• 2003

This study is to analyze the kinematic variables in release motion of discuss throwing. For the matter, 5 people from the national team and collegiate discuss throwing in the year 2001 were chosen as the subjects and two S-VHS video cameras set in 60frames/sec were used for recording their motions. Coordinated raw positions data through digitizing are smoothing by butter-worth 's low-pass filtering method at a cut off frequency 6.0Hz. and the direct linear transformation(DLT) method was employed to obtain 3-D position coordinates. The conclusions were as follows; 1. The better record players showed the shorter approach time in the last support phase. 2. In the displacement CG, the better record players showed the shorter displacement in medial-lateral direction, and the longer displacement in horizontal direction. In the motion, the COG showed longer displacement vertical direction. 3. The better record players showed the faster horizontal velocity than vertical velocity in the release. 4. The better record players showed to take the posture of vertical axis in the release.

• Transactions of Materials Processing
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• v.23 no.5
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• pp.297-302
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• 2014

The current paper introduces work that was conducted during the development of a stamping die for a reinforce center pillar made from high strength steel. In the current study, the Bauschinger effect on the springback analysis was studied by comparing simulation results with real panels, which are currently in production. For a complicated part shape, quantitative measurements of the deformed shape are not easy in general to obtain. An adjustment procedure of the shape data for some chosen sections has been suggested to improve the accuracy of the quantitative measurements. The results show that the kinematic hardening model provides more accurate results.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.3
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• pp.401-407
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• 2019

In this paper, the position estimation considering wheel slip of mecanum wheeled mobile robots is discussed. Since the mecanum wheeled mobile robot does not need a space to rotate, it is very suitable in narrow industrial fields. However, the slip caused by the roller attached to the wheel makes it difficult to estimate the position precisely. Due to these limitations, mecanum wheels are rarely applied to unmanned mobile robots in automation factories. In this paper, a method to compensate the orientation and distance error caused by the slip is proposed. The exact orientation is measured by fusing gyro and magnetometer sensor data with application of Kalman filter. In addition, the kinematic model accounting slip effects will be defined to compensate the distance error.

• Journal of Positioning, Navigation, and Timing
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• v.10 no.2
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• pp.83-89
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• 2021

The extended Kalman filter (EKF) is widely used for global navigation satellite system (GNSS) applications. It is difficult to obtain precise positions with an EKF one-way (forward or backward) filter. In this paper, we propose an EKF smoother to improve the positioning accuracy by integrating forward and backward filters. For the EKF smoother experiment, we performed PPP using GNSS data received at the DAEJ reference station for a month. The effectiveness of the proposed approach is validated with multi-GNSS kinematic PPP experiments. The EKF smoother showed 35%, 6%, and 22% improvement in east, north, and up directions, respectively. In addition, accurate tropospheric zenith total delay (ZTD) values were calculated by a smoother. Therefore, the results from EKF smoother demonstrate that better accuracy of position can be achieved.

• Journal of Positioning, Navigation, and Timing
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• v.10 no.1
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• pp.29-34
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• 2021

Recently, many studies have considered the effect of atmospheric pressure loading (APL) on precise global navigation satellite system (GNSS) data processing. The APL deforms the Earth's crust. It can often exceed 10 mm in radial displacement. In this study, we analyze the APL effect on Multi-GNSS kinematic precise point positioning (PPP). In addition, observations received at two GNSS reference stations (DAEJ and SUWN) in South Korea were processed. The absolute position changes for the two stations were compared to before and after applying the APL effects from January 1 to February 29, 2020. The crust of South Korea was most affected by the APL in the up direction. With the APL model, the difference in daily position changes was mostly within 4 mm in the radial direction. On the other hand, the horizontal components (east-west and north-south) were relatively less affected than the radial component.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.2
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• pp.170-177
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• 1993

In robotic arc welding, the roll (rotation) of the torch about its direction vector does not have any effect on the welding operation. Thus we could use this redundant degree of greedom for the motion control of the robot manipulator. This paper presents an algorithm for the pseudo- inverse kinematic motion control of the 6-axis robot, which utilizes the above mentioned redunancy. The prototype welding operation and the tool path are also graphically simulated. Since the proposed algorithm requires only the position and normal vector of the weldine as an input data, it is useful for the CAD-based off-line programming of the arc welding robot. In addition, it also has the advantages of the redundant manipulator motion control, like singularity avoidance and collision free motion planning, when compared with the other motion control method based on the direct inverse kinematics.

• Journal of the Korea Society of Computer and Information
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• v.29 no.8
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• pp.11-21
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• 2024

This study explores the use of virtual reality (VR) technology to identify and label key segments of the golf swing. To address the limitations of existing VR devices, we developed a platform to collect kinematic data from various VR devices using the OpenVR SDK (Software Development Kit) and SteamVR, and developed a semi-automated labeling technique to identify and label temporal changes in kinematic behavior through LSTM (Long Short-Term Memory)-based time series data analysis. The experiment consisted of 80 participants, 20 from each of the following age groups: teenage, young-adult, middle-aged, and elderly, collecting data from five swings each to build a total of 400 kinematic datasets. The proposed technique achieved consistently high accuracy (≥0.94) and F1 Score (≥0.95) across all age groups for the seven main phases of the golf swing. This work aims to lay the groundwork for segmenting exercise data and precisely assessing athletic performance on a segment-by-segment basis, thereby providing personalized feedback to individual users during future education and training.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.4
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• pp.377-386
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• 2015

Joint force/torque estimation by inverse dynamics is a traditional tool in biomechanical studies. Conventionally for this, kinematic data of human body is obtained by motion capture cameras, of which the bulkiness and occlusion problem make it hard to capture a broad range of movement. As an alternative, inertial motion sensing using cheap and small inertial sensors has been studied recently. In this research, the performance of inertial motion sensing especially to calculate inverse dynamics is studied. Kinematic data from inertial motion sensors is used to calculate ground reaction force (GRF), which is compared to the force plate readings (ground truth) and additionally to the estimation result from optical method. The GRF estimation result showed high correlation and low normalized RMSE(R=0.93, normalized RMSE<0.02 of body weight), which performed even better than conventional optical method. This result guarantees enough accuracy of inertial motion sensing to be used in inverse dynamics analysis.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.2
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• pp.183-190
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• 2002

This study is about the extraction of highway's superelevation using real time kinematic surveying among of GPS surveying methods which is economic method to construct data base in the side of highway maintain management. Using the developed vehicle, center line and shoulder of highway are measured and enough precision is obtained after analyzing the result. The result is show that 1.3 cm to 2.0 cm error in the clothed and about 0.8 cm to 1.2 cm error in the circular curve. Those errors are proved error to lane making during construction. This study is expected to become efficient method for extraction of highway alignment elements in the Mobile Mapping System.