• Journal of Oral Medicine and Pain
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• v.10 no.1
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• pp.63-71
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• 1985

A kinematical study of bite force during voluntary isometric contraction was investigated in 20 Korean men with TMJ dysfunction and 30 Korean men as normal subject, ranging from 20 to 27 years old. The author observed maximum bite force, slope of bite force graph, curve index and duration of maximum bite force with the use of the foil strain gauge (MPM-3000) and RS Dymograph (Beckman). The obtained results were as follows : 1. Maximum bite forces were 29kg and 29kg for left and right side of normal subject (p>0.05) and 19kg and 29kg for affected and non-affected side of TMJ dysfunction patient. 2. The slopes of bite force graph were $68^{\circ}$ and $68^{\circ}$ for left and right side of normal subject (p>0.05) and $59^{\circ}$ and $71^{\circ}$ for affected and non-affected side of TMJ dysfunction patient. (p<0.01) 3. The curve indices were 0.93 and 0.90 for left and right side of normal subject and 1.10 and 0.90 for affected and non-affected side of TMJ dysfunction patient. (p>0.05) 4. The durations of maximum bite force were 424 msec and 413 msec for left and right side of normal subject and 337 msec and 334 msec for affected and non-affected side of TMJ dysfunction patient. (p>0.05)

• Applied Microscopy
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• v.39 no.2
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• pp.175-183
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• 2009

In this paper we present sub-50 pm resolution images of atom columns simulated with the negative of the second derivative of the exit-plane wave function (EPW). The EPW can be retrieved from a focal series reconstruction in the (high resolution) transmission electron microscopy (HRTEM). The simulated images are for Si and InAs in [114] and [116] orientations, which give about sub-50 pm separations of atom columns. The theoretical reason for the validity of this method is given from analysis based on the kinematical diffraction theory, and the limitation for applicability of this method also is discussed.

• Korean Journal of Applied Biomechanics
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• v.15 no.1
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• pp.1-18
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• 2005

The purpose of this study was to evaluate performance characteristics. in the success of team attack during volleyball competition. For this, real game was analyzed using S-VHS video camera for three dimensional cinematography. The contents of this research were receive to set time, set to spike time, setter moving distance, ball position during set and attacker's relative ball position during jump and spike, and open area at spike. Among the various kinematical factors considered in this study, the ball height relative spiker and open area were found to be related to offensive performance. This finding implies that although their direct impact were not significant the other factors could have indirect impact on offensive performance by increasing open area. Thus, receiver, setter, assistant attacker, and main attacker should practice for successful performance in each stage. Lastly, it is necessary to develop kinematic variables to evaluate performance characteristics of players. Further study may consider the best defense position against the attack of the opponent player.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.67-79
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• 2003

The purpose of this study is to investigate the effective skill motion through the kinematic analysis of the Yurchenko Streched motion in new horse vaulting. The subjects in this study were 3 male gymnasts who were ranked as national athletes. After the 3D motion analysis, kinematic variables were analyzed to comparison with the difference between this study and the previous study(Yang, D. Y and Lee, C. S, 1999). As a result, the following conclusions was drawn; 1. In the board contact phase, this study showed a shorten contact time to maintain in condition highly extension of hip and hee angle than the previous study. 2. In the pre-flight phase, this study appeared more shortly flight duration time and horizontal flight displacement than the previous study. 3. In the horse contact phase, the contact duration time and horizontal displacement of COG shortened than the previous study, but appeared to the fast horizontal and vertical velocity and highly extension of shoulder an. 4. In the post-flight phase, a stable horse contact appeared to the increase of the flight duration time and the apex height during the post-flight. And it showed that these results have a stable and good landing.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.15-26
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• 2003

This study was conducted to investigate the performance times, CM position and CM speed, pole chord length and pole chord angle, whole body angular momentum(X axis), and grip width in pole vault event according to the event and phase; touch down, pole plant, take-off, maximum pole bending pole straight, pole release, peak height, and foot contact, pole contact, free flight. The pole vaulting of four male elite vaulters including six trial were filmed using two video digital cameras at 60 Hz at 56th national athletic match, and data were collected through the DLT method of three dimensional cinematography. In general the better jumper is, the longer the performance time is. And the greater CM speed is, and the better his transformation ability of CM horizontal speed into vertical speed is. As he uses a longer pole, his grip is higher, and it is a enough for him to rock back his body, so that he pulls and pushes the pole well keeping his hips close to. An greater maximum angular momentum and early positioning of the hips parallel to the bar makes his body far side of the bar and his bar clearance easier. Specially our national jumper needs to have more powerful braking force during foot contact phase, and take his body on the pole after maximum pole bending, and pull and push the pole strongly keeping his hips close to. Also he needs to have stronger muscular strength in order to control the longer pole and use the pole of proper tension more efficiently.

• Bulletin of the Korean Space Science Society
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• 2011.04a
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• pp.26.2-26.2
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• 2011

Flyby anomaly (unexpected energy increase during Earth Gravity Assists) indicates existence of an unknown non-conservative perturbation which affects hyperbolic trajectories. This presentation focuses on first order position and velocity perturbation formulas derived in terms of classical orbital element variations for hyperbolic orbit. By using both the perturbation formulas and numerical approach, we analyze effects of hypothetical acceleration models proposed by Hasse (2009), Lewis (2009), Gerrad and Sumner (2008), and Busack (2007). Based on analysis of perturbation effect on low earth orbit, we find that typical position perturbation is about 10m which is much larger than current orbit determination accuracy. From this, we deduce that anomalous acceleration only affects hyperbolic orbit or behaves differently in bound orbit. On the other hand, based on analysis of perturbation effects on hyperbolic trajectories, we find that position and velocity perturbations are highly different from acceleration models, and all of proposed models fail to explain observed range and Doppler data. Thus, it can be concluded that not only energy variations but also kinematics gives us crucial clues on the flyby anomaly, and kinematical characteristic should be considered in modeling flyby anomaly.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.2
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• pp.92-101
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• 1997

The purpose of this welding process of the exclusive welding-machine using welding torch-rotation type is to develop a mechanism which can solve the problem of twisting of welding wires and cables. The technique was developed by revising the torch position and smooth controlling of both the normal and reverse rotation. Some of the advantages of using the torch-rotation type apply to the work-rotation technique are the practical uses of increased work space and link work with the factory automation system. Do apply the welding process, I designed and made a special unit so called torch part in order to solve the problems of kinematical. And I made a control panel which can manipulate the progress of the entire process at the work shop. Even if it will be applied to another kind of axle casing's welding work, this process can be utilized if other sizes of the fixed pin and work part is produced and changed. The development of this exclusive welding-machine could reduce the manpower of skilled welding labor and increase productivity and better quality product in comparison to the handmade product.

• Computers and Concrete
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• v.15 no.5
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• pp.735-758
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• 2015

This work deals with unilateral effect of quasi-brittle materials, such as concrete. For this propose, a two-dimensional meso-scale model is presented. The material is considered as a three-phase material consisting of interface zone, matrix and inclusions - each constituent modeled by an appropriate constitutive model. The Representative Volume Element (RVE) consists of inclusions idealized as circular shapes randomly placed into the specimen. The interface zone is modeled by means of cohesive contact finite elements developed here in order to capture the effects of phase debonding and interface crack closure/opening. As an initial approximation, the inclusion is modeled as linear elastic as well as the matrix. Our main goal here is to show a computational homogenization-based approach as an alternative to complex macroscopic constitutive models for the mechanical behavior of the quasi-brittle materials using a finite element procedure within a purely kinematical multi-scale framework. A set of numerical examples, involving the microcracking processes, is provided. It illustrates the performance of the proposed model. In summary, the proposed homogenization-based model is found to be a suitable tool for the identification of macroscopic mechanical behavior of quasi-brittle materials dealing with unilateral effect.

• The Journal of Korea Robotics Society
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• v.2 no.1
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• pp.48-54
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• 2007

A network-based robot [1] is a robot that explores service servers in the network environment for analyzing sensor data and making decision. Since network-based robot architecture was proposed, it's possible to reduce costs of robots. We hope robots would be all around at home environment. Therefore, normal users who are not experts need to be able to control those robots by using easy commands. We developed a scripting language, named CCSLR, to help users and developers who control various robots in ubiquitous environment. We focused on how to design the common language for various robots and how to translate a CCSLR script into a sequence of low-level commands of the target robot. In this paper, we propose scripting methods, with three layers. The CCSLR system reads the profile information from the knowledge representation database. Users don't have to know all about kinematical and mechanical details of a robot. Then again, the CCSLR system will use the profile information to translate the script into separated executable library commands. The CCSLR system manages robot's changing state every time a robot executes a command.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.1
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• pp.13-17
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• 2001

The configuration design of kinematic mechanisms of industrial sewing machine has been studied using a functional approach. The configuration design methodology has been applied to shorten the development cycle time of mechanisms and to manage design data efficiently Expert system has been used to embody the decomposition of functional requirements. It has been interfaced with a CAD system through the API program to show the assembly and parts of the mechanism. Constraints also can be handled by the expert system through the rule induction and the case based reasoning process. The configuration design system includes the kinematical analysis and optimization of the mechanisms of an industrial sewing machine by the interface between the expert system and an analysis program by means of API Program supplied by expert system. The conceptual design of sewing machine mechanism can be Performed rapidly and efficiently.