• 한국운동역학회지
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• 제22권1호
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• pp.17-24
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• 2012

This study is for providing fundamental data of sport biomechanics in GRF & plantar pressure of stepping foot of skilled & unskilled players' at the soccer instep shooting moments. Wearing Pedar-x of Novel, the study has drawn the following conclusion after measuring and analyzing the impact on the GRF and plantar pressure of stepping foot at the instep shooting moments. First, maximum vertical GRF showed higher in the skilled group than in the unskilled group. The results showed significantly different. This study reached the conclusion that the players in the skilled group performed faster and stronger stepping foot motions that the ones in the unskilled(p<.01). Second, since the plantar pressure of the skilled group appeared significantly higher than that of the unskilled, it has brought us to the conclusion that the skilled group performed faster and stronger stepping foot motions than the unskilled group (p<.05). Third, at the moment of instep kicking, the skilled group's average maximum plantar foot pressure of stepping foot was higher than the unskilled. Though the difference was not statistically significant, it can be concluded that the skilled group performed faster and stronger stepping foot motions than the unskilled group(p>.05). Fourth, for the COP moving route of stepping foot while instep kicking, the skilled people performed accurate and strong shooting motions directly toward the target direction with stable postures, no matter how it's left, right, front or back.

• 한국사이버테러정보전학회:학술대회논문집
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• 한국사이버테러정보전학회 2004년도 제1회 춘계학술발표대회
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• pp.233-239
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• 2004

본 논문에서는 현재 네트워크 환경에서 Stepping Stones을 이용한 경유지 우회 공격에 대한 침입자 추적 메커니즘을 제안한다. 침입자는 피해시스템에서 공격자의 IP주소 노출을 피하기 위하여 피해시스템을 직접 공격하지 않고 Stepping stone을 이용하여 경유지 우회 공격을 수행한다. 우리는 이와 같은 경유지 우회 공격 발생 시 공격자의 IP주소의 추적을 목적으로 한다. 침입자 추적은 크게 두 가지 분류로 나뉘어 진다. 첫째는 IP Packet traceback, 둘째는 Connection traceback 이다. 본 논문에서는 Connection traceback에 공격을 다루며, 운영체제의 프로세스 구조를 이용하여 공격자 또는 Stepping stone(경유지)을 구분하여 침입자의 위치를 추적한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.466-466
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• 2000

This paper presents the sinusoidal current ministep technique to drive stepping motor. The stepping motor is coupling to the increment encoder to detect the position and speed of the stepping motor. The data from the encoder is decoded to sine and cosine signal and fed to the driver system. The driver system has two loops control, the inner loop and the outer loop. The inner loop is used to control the rotating of the stepping motor and the outer is used to control the speed of the motor. The rotating of the stepping motor is controlled with the sinusoidal signal. The test results of the inner loop control can control the revolution of the stepping motor is smooth and continuously with similar to the DC motor. The outer loop uses to control the speed of the stepping motor with control the DC voltages apply to the driver. The DC voltages that apply to the driver is controlled by the AC-DC converter The test results of the outer loop control, it can control the speed of motor which is provide the any load in the design.

• 전력전자학회논문지
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• 제27권6호
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• pp.481-488
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• 2022

This study proposes compensation methods for the initial position error and torque ripple in vector control of two-phase hybrid stepping motors. Stepping motors have an asymmetrical structure due to misalignment, such as the eccentricity generated by the manufacturing and assembly process. When vector control is applied using the position information measured by an incremental encoder attached to the rotor shaft of such stepping motors, the following problems occur. First, an initial position error occurs during the forced excitation process for the initial rotor position alignment. Second, torque ripple corresponding to the mechanical rotation frequency is generated. In this study, these non-ideal phenomena that occur in vector control of the stepping motor are analyzed, and compensation methods are proposed to eliminate them. The validity of the proposed initial position error and torque ripple compensation methods is verified through experiments on a two-phase hybrid stepping motor drive system.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제28권3호
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• pp.88-95
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• 2024

In this article, we propose an efficient and accurate adaptive time-stepping numerical method for the Black-Scholes (BS) equations. The numerical scheme used is the finite difference method (FDM). The proposed adaptive time-stepping computational scheme is based on the maximum norm of the discrete Laplacian values of option values on a discrete domain. Most numerical solvers for the BS equations require a small time step when there are large variations in the solutions. To resolve this problem, we propose an adaptive time-stepping algorithm that uses a small time step size when the maximum norm of the discrete Laplacian values on a discrete domain is large; otherwise, a larger time step size is used to speed up the computation. To demonstrate the high performance of the proposed adaptive time-stepping methodology, we conduct several computational experiments. The numerical tests confirm that the proposed adaptive time-stepping method improves both the efficiency and accuracy of computations for the BS equations.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2001년도 춘계 학술대회논문집
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• pp.127-133
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• 2001

In this paper, the preconditioned multistage time stepping methods which are popular multigrid smoothers is studied for the compressible flow calculations. Fourier analysis on the local time stepping and block-Jacobi preconditioned residual operators is performed using the linearized 2-D Navier-Stokes equations. It fumed out that block-Jacobi preconditioner has better performance in eigenvalue clustering. They are implemented in the 2-D compressible Euler and Wavier-Stokes calculations with multigrid methods to verify that the block-Jacobi preconditioned multistage time stepping shows better performance in convergence acceleration.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 전력전자학술대회 논문집
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• pp.295-298
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• 1998

A Linear Stepping Motor(LSM) can operate in an open loop control mode similarly to a rotary stepping motor. However, the LSM has a large transient vibration, and it sometimes causes the miss-step. In this paper, vibration suppression method using an energy stored in winding inductance and induced voltage of the LSM is proposed.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.45-47
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• 2005

A digital controller of stepping motors is designed for removing mid-range resonance. Rotor oscillation is detected from motor currents and the microprocessor generates frequency modulation taking into account rotor oscillation. ATmega16 is employed and the controller drives stepping motors up to 3000[rpm] at micro stepping.

• Journal of Electrical Engineering and Technology
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• 제12권3호
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• pp.1219-1226
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• 2017

This paper presents the hybrid stepping machine for linear oscillating generators. The focus of the work is the suggestion of the improved model through the comparison of proposed models ; new flux concentrating PMs mover of the hybrid stepping generator is proposed based on the symmetrical and non-symmetrical stator cores of the surface mounted PMs mover, and non-slanted PMs and slanted PMs of the flux concentrating PMs mover. It is achieved using equivalent magnetic circuit considering leakage elements. Finally, this study suggests new hybrid stepping structure of linear oscillating generator.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1996년도 창립기념 전력전자학술발표회 논문집
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• pp.56-59
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• 1996

In this paper, we developed a micro-stepping drive circuit of step motor and proposed software algorithm for parallel operation of step motors drived by micro-stepping circuit. Also, we implemented a parallel operation controller with a 16-bit micro-controller.