• Journal of Digital Convergence
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• v.17 no.12
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• pp.555-563
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• 2019

This study was to provide quantitative basic data on the forehand and backhand throw movements of flying disks. For this purpose, the kinematic variables were calculated using the three-dimensional motion analysis system. A comprehensive analysis of the study variables showed that it is important to throw flying disks accurately as well as far away, so in P2 and P3 it is necessary to control forward movement and concentrate on the rotation of the joints. In addition, rotational force transfer from pelvis to body is considered important for efficient rotational movement. The forehand was found to mainly utilize the movement of the upper extremity joint to perform throwing motion, while the backhand throw was found to be relatively utilized for the rotation of the torso and pelvis. Based on the quantitative data of this study, we hope that it can be used as a basic material for on-site training of Flying Discs.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.673-675
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• 1999

본 논문은 기존의 유선환경에서의 서비스 환경을 이동 환경에서도 지원하기 위한 분산 구조를 다루고 있다. 이를 위하여 이동 단말기를 논리적으로 대신하는 이동 AP의 위치를 추적하는 추적 AP를 두어 기존의 응용 환경에서 수행되던 응용 프로그램들을 무선이동 환경에서도 수용할 수 있도록 하였다. 이동 단말기의 위치 변경에 따른 이동 AP, 추적 AP 사이에서 발생되는 핸드오프처리 알고리즘이 소개되었으며, 이 알고리즘은 패킷 손실이나 순서의 변경과 같은 흐름제어 기능을 포함하고 있다. 또한 무선 환경에서 발생 가능한 핸드오프와 소프트 핸드오프를 함께 고려하였다. 시뮬레이션의 결과는 핸드오프 과정에서의 추가 지연 시간에 대한 내용을 다루고 있다.

• The monthly packaging world
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• s.152
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• pp.75-77
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• 2005

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.4
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• pp.488-499
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• 1999

본 논문은 사용자 단말기의 이동성을 지원하기 위한 이동 컴퓨팅 구조에 대한 내용을 다루고 있다. 이를 위하여 사용자 MS, 고정망에서 MS를 대신하는 이동 에이전트 프로세스, 핸드오프 과정에서 MS에 중단없는 서비스를 제공하기위하여 이동 에이전트 프로세스의 위치를 추적하는 추적 에이전트 프로세스에 관한 내용을 소개한다. 논문에서 소개되는 추적 에이전트 프로세스의 도입으로 유선 환경의 응용서비스들의 무선 이동 환경에서도 호환성을 가질 수 있는 장점을 갖게 된다. 핸드오프 알고리즘은 패킷 손실이나 순서의 변경과 같은 흐름제어 기능을 포함하고 있으며, 무선핸드오프에서 발생 가능한 하드 핸드오프와 소프트핸드오프를 함께 고려하였다. 시뮬레이션의 결과는 핸드오프과정에서의 추가 지연 시간에 대한 내용을 다루고 있으며 각 객체간의 거리를기준으로 분석하였다.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.11-19
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• 2008

This study was conducted with 8 male table tennis players who won national competitions. Of the subjects, 4 used a racket of penholder grip and 4 used one of shake hand grip, and all of them were right.handers. We analyzed three-dimensional angular characteristics such as angular component, swing trajectory and swing posture related to the racket swing motions of forehand drive and smash in table tennis, and drew conclusions as follows. Racket angle(p<.05) and racket swing angle(p<.01) were significantly different between the two motions. In smash, the back swing posture maintained the racket angle large by holding the racket upright and made the racket swing angle small for high ball speed. In addition, the height of the racket head in back swing posture was also significantly different between the two motions. In phg on impact, the open angle of the long axis of the racket was significantly different between the two motions. This shows that impact was applied a bit behind for giving top spin to the ball. In the back swing of drive, the gradient of the upper body was slightly larger in shg than in phg probably because of the structural difference of the racket grip in the neutral posture.

• Journal of Advanced Navigation Technology
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• v.14 no.6
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• pp.865-873
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• 2010

In this paper, a novel schedulability criteria is developed to provide handover calls with Quality of Service (QoS) guarantees in terms of both minimum available bandwidth, maximum tolerated packet delay, and other additive QoS constraints as required by the real-time mobile traffic. This requires prediction of the handover time using mobility trends on the mobile station, which is used as input to this work. After the handover time and the QoS are negotiated, the destination base station makes attempts to give priority to handover calls over new calls, and pre-reserves resources that will have more chance of being available during the actual handover.

• Review of KIISC
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• v.23 no.5
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• pp.36-45
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• 2013

TLS 프로토콜은 인터넷 보안에서 가장 널리 사용되는 핵심 기술로서, 핸드쉐이크(handshake) 프로토콜과 레코드 레이어(record layer) 프로토콜로 구성된다. 핸드쉐이크에서 형성된 키를 이용하여 레코드 레이어 프로토콜에서 데이터들에 대해 인증, 무결성, 기밀성과 같은 정보보호 서비스를 제공한다. 이와 같이, TLS 프로토콜은 키 공유라고 하는 고전적인 암호학 문제를 포함하고 있기 때문에, 암호학 연구자들에게 접근성이 매우 뛰어난 연구 주제가 되어 왔다. 이를 반영하듯, 최근에 암호학 분야의 최고 권위 있는 Crypto학회에 TLS 이론 연구에 관한 논문이 연속적인 주제로 게재되었다. 본 논문에서는 최근 Crypto학회 및 eprint에 올라온 TLS와 관련된 최신 연구 동향 및 결과를 분석하여, TLS 프로토콜의 안전성을 연구하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.6
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• pp.43-53
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• 2014

Supporting handover functionality in V2I communication environments is important to provide higher quality service to users on the road. Wireless Access in Vehicular Environments(WAVE) standards define some features that devices can communicate with each other more efficiently in vehicular environments but they do not include handover function for providing effective V2I services. In this paper, we introduce a handover scheme in WAVE system and show the performance result of proposed scheme.

• Korean Journal of Applied Biomechanics
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• v.18 no.4
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• pp.151-159
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• 2008

In this research, kinematic comparative analysis was performed on strokes of abscission and spinal cord injured athletes who participated in 2008 Beijing Paralympics wheelchair table tennis games. Strokes of all situations were collected under real match-like conditions. Among those, three major forehand stroke motions and backhand stroke motions were drawn Data collected by 9 infrared cameras were expressed in angular motions using graphic program LabVIEW7.0. As a result, forehand stroke of spin handicap athlete from analyzed images, the rotations of the trunk happened with the rotations of shoulder and the flexion extensions of elbow nearly at the same time. According to these results, insufficient turning force or speed of rackets is recompensed using flexion. backhand stroke of spin handicap athlete from analyzed images, the rotations of the trunk, the flexion extensions of the elbow and the flexion extensions of the shoulder were lined up on the prolongations of ping-pong balls. Forehand stroke of abscission athletes was done by outward rotation of the arm using backswing and inner rotation. As for backhand stroke, backswing was made by inner rotation in the spin of shoulder and waist. And after the backswing, impact was formed in wide outer rotation towards the ball.

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.449-455
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• 2009

The purpose of this study was to analyze the kinetics variables of GRF by dtance type during forehand stroke. Eight high school tennis players, who have never been injured for last six months, in Busan were chosen for the study. They performed horizontal swing and vertical swing that it was done each five consecutive trial in the condition of square, semi-open and open stance. It was filmed by 6 video camera and used with 3-dimensional motion analyzer system and GRF system. The following kinetic variables were analyzed in relation to left leg and right leg GRF. The conclusion were as follow: 1. In square and semi-open stances, the horizontal ground reaction force was decreased at impact in left leg regardless of swing type, whereas open stance was increased at impact to the tiptoe in both legs. 2. In square and semi-open stances, the vertical ground reaction force was increased at impact in left leg regardless of swing types, whereas open stance was decreased at impact to vertical direction in both legs.