• Tribology and Lubricants
• /
• v.23 no.2
• /
• pp.61-65
• /
• 2007

It is very important to connect machinery and maintain it. This is usually done by bolt joint. There are two ways in connecting the bolt joint : the angle method and the torque method. The torque method is a method that let the clamping force maintain. The underhead of the bolt's head and the thread friction are the main influences. This study focuses on how the clamping farce and friction coefficient change under the condition in vibrating the underhead of the bolt's head part. As a result, under vibration condition, we found out that the clamping farce increases, while the friction coefficient decreases.

• Progress in Superconductivity
• /
• v.5 no.2
• /
• pp.141-143
• /
• 2004

For designing a flywheel system using superconductor, it is necessary to understand the basic characteristics of the classical superconductor bearing. It is difficult to expect the characteristics of superconductor bearings using models that have been introduced up to now. In the "Frozen image" concept, the farce between the permanent magnet and the superconductor can be divided into two forces between permanent magnet and two imaginary magnets in the superconductor; one represents attraction farce and the other represents a repulsion force. We calculated the characteristics of two superconductor bearings, such as an axial, the radial stiffness and the levitation force. This calculation method was very helpful to expect the characteristics of the superconductor bearings. Using this model, we established the optimum condition for the superconductor bearing.r bearing.

• Journal of Welding and Joining
• /
• v.20 no.3
• /
• pp.98-104
• /
• 2002

A study on microstructures of welds for Zircaloy-4 sheath end closure by the resistance upset welding methods was carried out. Two upset welding process variations such as magnetic farce and multi-impulse resistance welding were used. Grain size and microhardness across welds were analysed in terms of welding parameters. Magnetic farce resistance weld with one cycle of unbalanced mode has smaller upset length and $\alpha-grain$ size in heat affected zone than those of multi-impulse resistance weld because of lower heat input and shorter welding time. Heat affected zone formed by two upset resistance welding variations revealed fine Widmanstatten structure or martensitic ${\alpha}'$ structure due to the high heating rate and foster cooling rate. Magnetic force resistance welds showed recrystallized grains before grain growth, whereas multi-impulse resistance welds showed full grain growth.

• Journal of Institute of Control, Robotics and Systems
• /
• v.12 no.11
• /
• pp.1088-1094
• /
• 2006

In this paper, an auto path generation and an active compliance grinding control using 3-axis farce sensor are presented. These control algorithms enable the grinding robot to follow unknown path of various workpiece shape pattern. The robot is able to go grinding along unknown paths by position controller managing tangential direction angle and cutting speed, with only information about the start position and the end position. Magnitude and direction of normal force are calculated using force data that go through low pass filter. Moreover, normal and tangential directions are separated for force control and velocity control, respectively.

• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.1
• /
• pp.198-203
• /
• 2000

In this paper, a numerical analysis is carried out to show the effect of friction farce on the dynamic characteristics of a flow divider valve. The continuity equations and the equation of motion fur spool are numerically solved. The viscous friction force acting on the spool is considered analyzing the Reynolds equation which governs the viscous flow in the clearance gap between the spool and sleeve. Dynamic characteristics are highly affected by the viscous friction farce whose magnitude is relatively small compare with other fluid forces. Therefore present theoretical formulation and numerical scheme can be used generally in designing and performance evaluation of all the hydraulic spool valve.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2001.09a
• /
• pp.107-114
• /
• 2001

When group pile supporting structures are to be subjected to large lateral loads, generally, hatter piles are used in group pile with vertical piles. It is well known that batter piles resist lateral static loads which are acted upon the piles as axial farces quite well but, they show a poor performance under seismic loads. However, it is not yet known how the batter piles behave under dynamic loading and how to strengthen the batter piles to improve the seismic performance. Shaking table tests were performed to investigate the seismic behavior of the batter pile and to bring up the countermeasures to improve the seismic performance. As the result of the shaking table tests, batter piles failed due to not only the excessive increase of compressive force near the pile head but also that of tensile force. In case that the pile head was connected with pile cap by rubber joint, the max. acceleration at the pile cap was reduced due to the high damping ratio of rubber and the max. moment and max. axial farce at the pile head was decreased remarkably. When the inclinations(V:H) of the batter pile were 8:3 and 8:4, max. moment, max. shear force, and max. axial farce were reduced notably and max. acceleration and max. displacement at the pile cap was diminished, too.

• Proceedings of the KIEE Conference
• /
• 2002.11d
• /
• pp.334-340
• /
• 2002

This paper proposes a new anti-slip re-adhesion control system fur electric railway vehicle driven by inverter-fed induction motors. This paper introduces an instantaneous tangential farce coefficient estimator between driving wheel and rail, which is based on disturbance observer. The torque command of proposed system regulates to exceed this estimated tangential farce coefficient in order to avoid undesirable slip phenomenon of driving wheels. We have already proposed the anti-slip re-adhesion control system based on disturbance observer for simplified one wheel equivalent model successfully. This paper extend to this system to the actual bogie system, which has four driving wheels driven by two induction motors fed by one inverter. In order to apply anti-slip re-adhesion control to the actual bogie system a new anti-slip re-adhesion control based on both disturbance observer and speed sensor-less vector control of induction motor with quick response are combined. The experimental results and the numerical simulation results prove the validity of the proposed control system.

• Journal of Korea Entertainment Industry Association
• /
• v.15 no.4
• /
• pp.89-100
• /
• 2021

Comedy has been popular since ancient Greece. In order to visualize comedy more effectively, the actor's acting acts as an important factor. Then active discussion is needed on how actors can actually shape their comedic performance. I would like to approach comedic acting methods, focusing on the character of Kim Seo-young in the play . This researcher played the character of Kim Mi-young, and the characteristics of comedic acting include exaggeration, repetition, fast tempo, changing tone, and exaggerated physical behavior. Comedic acting comes from a dissonance of reactions. This is because unexpected reactions to stimuli can cause audience laughter. Comedic acting is also important in exaggeration and repetition, which must be based on true acting. The fast tempo of the act and the changing tone of the words also affect comedic acting expressions, and the embodiments of 'slapstick' and 'group dance', which are characteristics of farce acting, play an important role in causing audience laughter. In order for these characteristic elements to show comic effects, the actor's true acting must be the basis. What is important in comedic acting is understanding the narrative flow and features of the text and expressing it accurately. Comedic effects can be sufficiently represented if an actor truly expresses his means and faithfully demonstrates what the text requires. It is hoped that such research will help explore various acting arts, the acting education field, and the theater creation process.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.05a
• /
• pp.293-296
• /
• 2002

This work presents the reconstruction of impact force produced by the collision between two elastic structures. The 2-DOF impactor was designed. The shape control of impact farce using correlations of the dynamic characteristics and impact force history between two elastic structures is accomplished. The effects of the relative motion between impactor and elastic structure on the impact force shape are studied. Reconstruction characteristics of impact force in cantilever beam are reviewed.

• Proceedings of the KIEE Conference
• /
• 1994.07a
• /
• pp.69-71
• /
• 1994

In fabricating linear actuator using the GMA(Giant Magnetostrictive Alloy : Terfenol-D). the clamping unit is needed to accumlate each displacement from the GMA rod. Two types of the clamping unit (one is using piezoelectric device and the other electromagnetic farce) were made and tested. From the result of the experiment, we conclude that the electromagnetic clamping unit has advantages over the piezoelectric clamping unit.