• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.507-512
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• 1987

Input/output equations in SDINS IMU are modeled from survey of IMU data flow. Given without precise equipments which can generate acceleration and angular velocity, a simple method is derived to calibrate the parameters of i/o eqijations. Also in order to upgrade ins performance, methods to estimate variant magnitudes of time variant parameters are surveyed.

• 한국기계연구소 소보
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• s.18
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• pp.99-104
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• 1988

The method of simulation for ballistic feeding mechanical system is presented. Taking photograph of roller drived by a force of explosion, searches the motion of roller. The algorithm that a motion of roller is converted into a motion of cam is presented. Using central difference method, the angular velocity and acceleration of cam is evaluated.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.3
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• pp.245-253
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• 2006

A test of the 1/3 scale model was conducted to verify the tip-over analysis of a dry. concrete storage cask under a hypothetical accident condition. The tip-over analysis was executed using the velocity at each point as the initial conditions of the model just before the impact. The initial velocity was determined from the initial angular velocity, which would make the equivalent kinetic energy to the potential energy. To confirm the structural integrity of the canister, the visual testing and the non-detective testings such as Liquid Penetrant testing and Ultrasonic Testing were conducted. The lid of a storage cask was plastically deformed near the impact point. The structural integrity of storage cask was maintained. To verify the tip-over analysis the strains and the accelerations acquired by the tip-over test were compared with those by the analyses. The results of the analysis were larger than the test results about two times.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.688-697
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• 2017

It is very difficult to solve mathematically the optimal control problem for non - linear mobile robots to move to target points with minimum energy related to velocity, acceleration and angular velocity in minimum time. This paper proposes a method to obtain optimal control gains with which mobile robots move with minimum energy related to velocity, acceleration and angular velocity in minimum time using genetic algorithms. Mobile robots are non - linear systems so that their optimal control gains depend on initial positions. Hence initial positions are divided into some partition points and optimal control gains are obtained at each partition point with genetical algorithms. These optimal control gains are used to train neural networks that generate proper control gains at arbitrary initial position. Finally computer simulation studies have been conducted to verify the effectiveness of the method proposed in this paper.

• Korean Journal of Applied Biomechanics
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• v.23 no.4
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• pp.347-355
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• 2013

The purpose of this study was to determine the biomechanical effect of wearing the mouthguard on the lower limb during drop landing. Nine male university students who have no musculoskeletal disorder were recruited as the subjects. Linear velocity, angular velocity, vertical GRF, loading rate, joint moment, and lower extremity muscle activity were determined for each subject. For each dependent variable, paired t-test was performed to test if significant difference existed between with mouthguard (WM) and without mouthguard (WOM) conditions (p<.05). The results showed that linear velocity, angular velocity, vertical GRF and loading rate were no significant difference between the two groups. The inversion moment of the ankle joint was increased in WM compared to WOM. Average IEMG values from BF, TA, and LG in WM were significantly greater than corresponding values in WOM during IP phase. This indicates that wearing mouthguard played a vital role in muscle tuning for maintaining joint stability of the lower limb and preventing injury.

• Membrane Journal
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• v.6 no.4
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• pp.219-226
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• 1996

Rotary disc ultrafiltration module(RDM) was developed for the separation of oil emulsions. This module was devised to reduce the gel polarization phenomenon by alecoupling the operation pressure and the surface velocity of solution in ultrafiltration(UF) processes. Two-shaft engaged disc type RDM having 20 rotary disc membcanes(UOP, USA) was operated under 85kPa vacuum at $25^{\circ}$C. The pressure drop due to slip flow in the two-shaft RDM was found to be proportional to $(2.5{\omega}r)^{2}$. The pure water flux of two-shaft RDM decreased by 9.95% at the angular velocity of 41.89rad/s compared to the decrease of 3.01% for one-shaft RDM at the same velocity. When the angular velocity was changed from 31.42rad/s to 2.62rad/s, the flux decline for 1% cutting oil in two-shaft RDM was 30.16% that is similar to that of one-shaft RDM. Disc gap of 3mm and 7mm did not show any significant differences in the flux for 1% cutting oil solution. A modified model for two-shaft RDM showed good agreement with the experimental results for the cutting oil solution.

• Korean Journal of Applied Biomechanics
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• v.15 no.3
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• pp.79-94
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• 2005

Because the golf swing is very complex movement, it is varied in different gender, skill level, and club. This study measured kinematic variables in golf swing regarding gender, skill level, and club types using FasTrak electromagnetic tracking system. Golf swing kinematics including time variables, linear and angular displacement variables, angular velocity variables were analyzed and compared through three-way ANOVA The results were as follows: 1. In time variables, Female and driver showed longer backswing time than male and iron. Downswing time was longer in female and nonexperts than male and experts. Backswing time over downswing time was longer in experts than nonexperts. Uncocking time was longer in male and experts than female and nonexperts. The differences were statistically significant (p<.05). 2. In displacement variables, Female and nonexperts showed greater backswing head lift than male and experts. Impact head lift was greater in female, nonexperts, and iron than male, experts, and driver. The differences were statistically significant (p<.05). Experts and driver showed greater top hip rotation angle than nonexperts and iron. Top shoulder rotation angle was greater in male, experts and driver than female, nonexperts, and iron. X-factor was greater in male, experts, and driver than female, nonexperts, and iron. Male and experts showed greater backswing hip sway than female and nonexperts. Impact hip sway was greater in male and iron than female and driver. The differences were statistically significant (p<.05). 3. In velocity variables, Experts displayed higher impact hip rotation velocity than nonexperts. Impact shoulder rotation velocity was greater in male and iron than female and driver (p<.05).

• Korean Journal of Applied Biomechanics
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• v.22 no.4
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• pp.429-435
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• 2012

The purpose of this study was to determine the biomechanical effect of wearing carbon nanotube-based insole on cushioning and muscle tuning during drop landing. Twenty male university students(age: $21.2{\pm}1.5yrs$, height: $175.4{\pm}4.7cm$, weight: $70.2{\pm}5.8kg$) who have no musculoskeletal disorder were recruited as the subjects. Average axial strain, average shear strain, inversion angle, linear velocity, angular velocity, vertical GRF and loading rate were determined for each trial. For each dependent variable, a one-way analysis of variance(ANOVA) with repeated measures was performed to test if significant difference existed among different three conditions(p<.05). The results showed that Average axial strain of line 4 was significantly less in CNT compared with EVA and PU during IP phase. The average shear strain was less in CNT compared with EVA and PU during other phases. The inversion angle was increased in CNT compared with EVA and PU during all phase. In linear velocity, angular velocity, vertical GRF and loading rate, there were no significant difference between the three groups. This result seems that fine particle of carbon nanotube couldn't make geometric form which can absolve impact force by increasing density through eliminating voids of forms. Thus, searching for methods that keep voids of forms may play a pivotal role in developing of insole. This has led to suggestions of the need for further biomechanical analysis to these factors.

• Journal of IKEEE
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• v.26 no.2
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• pp.150-159
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• 2022

In this paper, we propose a physics simulation for augmented reality (AR) billiards content. The characteristics of the physics simulation for the proposed AR billiards content are as follows. First, physical equations are derived by calculating the force and moment of inertia applied to the billiards ball to realize the motion of the billiards ball similar to the real one in the AR environment. Then, we determine the velocity and angular velocity of the virtual billiards ball associated with the rotation of the virtual billiards ball with respect to the impact point. Second, using some vectors such as incidnet vector, normal vector, reflection vector, the trajectory of the virtual billiards ball would be implement. these equations are applied to AR environment so that AR billiards content could be implement. This physics simulation allows users to feel like the real world using a virtual pool table and induce them to interact with the real environment. As a result of the experiment, the accuracy range between the path of the real billiards ball and the path of the virtual billiards ball was calculated to be 97.75% to 99.11%. Therefore, it was determined that the performance of the physics simulation for the AR billiards content proposed in this paper performs similarly to the path of the real billiards ball.

• 한국체육학회지인문사회과학편
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• v.53 no.2
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• pp.531-540
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• 2014

The purpose of this study was to investigate the differences between two inflatable kayak by recording performance related variables during the kayak forward stroke motion. A total of 5 elite high school kayak players were recruited to participate while their kinematics and muscle activations were recorded while performing inside their high school swimming pool. Boat velocity, boats swaying angle, the average angular velocity and were used to evaluate the boats performance. The player's trunk rotational range of motion, knee flexion-extension angle range of motion, maximum trunk rotation angle, the knee flexion-extension angular velocity, and the upper and lower limb muscle activations were calculated and analyzed for the player's efficiency evaluation. There were no significantly different variables for the player's kinematics and their muscle activations for the two conditions. The B kayak was significantly faster than the A kaya. In addition there were no significant differences between the remaining variables for the two kayaks. In conclusion, the B kayak was faster than the A kayak, but neither of the kayaks had an influence on the player's performance variables.