• 한국감성과학회:학술대회논문집
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• 한국감성과학회 1999년도 추계학술대회 논문집
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• pp.111-114
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• 1999

Off-vertical axis rotator was developed to differentiate each function of the canal and otolith in the vestibular system and evaluate subjective symptoms during postural change. Eye movement induced by various types of rotation was measured in normal subjects. Nystagmus with fast component corresponding to direction of rotation was occurred by sinusoidal earth vertical axis rotation, and the gain of eye movement in vestibuloocular reflex (VOR) was lower than in visual vestibuloocular reflex (VVOR) and higher than in visual fixed vestibuloocular reflex (VFX). Degree of dizziness was proportioned to degree of gain. off-vertical axis rotation was produced severe dizziness than earth vertical axis rotation. These results suggest stimulation of the otolith should be minimized to make a stable and pleasant condition in work and travel.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.377-380
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• 2001

The vestibular system located in the inner ear controls reflex body posture and movement. It has the semicircular canals sensing an angular acceleration and the otolith organs sensing a linear acceleration. With this organic signal, medical doctor decide if a person has disease or not. To obtain this data, a precision stimular system is considered. Robust control is needed to obtain eye signals induced by off-vertical axis rotation because of an unbalanced load produced by tilting the axis of the system upto 30 degrees. In this study, off-vertical axis rotatory system with visual stimulation system are developed. This system is consisted of head mounted display for generating horizontal, vertical, and three dimensional stimulus patterns. Furthermore wireless recording system using RF modem is considered for noiseless data transmission.

• 전력전자학회논문지
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• 제6권4호
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• pp.325-332
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• 2001

전징기관은 내이에 존재하며 유연한 동작과 몸의 자세 그리고 운동을 조절한다. 이 기관은 회진 가속도를 감지하는 세반고리관과 선형 가속을 감지하는 이석기관으로 구성된다. 이러한 기관의 생체 신호로부터 의사는 사람이 환자인지를 판단한다. 이 신호의 데이터를 얻기 위해서 회전의자 한쪽을 들어올려 최대 30도까지 기울인 상태에서, 회전제어하게 되는데, 이 경우 부하의 불균형으로 인한 불평형 부하를 제거하고, 생체신호의 측정을 위하여 robust제어가 요구된다. 본 연구에서는 자세조절기능에 대한 이석기관의 역할을 추구하기 위하여 탈수직축 회전자극기를 개발하였으며, 공간을 차지하고 다양한 시각패턴을 만들지 못하는 기존 시각자극시스템의 단점을 해결하기 위하여 HMD를 이용한 시각자극 시스템을 개발하였다. 더구나 노이즈에 취약한 아날로그 신호인 ENG신호의 전송문제를 해결하기 위하여 근거리 R/F 무선시스템으로 개발하였다. 이상의 제안된 시스템을 제작하고 실험한 결과를 보고하였다.

• 한국운동역학회지
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• 제13권2호
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• pp.75-87
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• 2003

The purpose of this study was to identify the mechanical factors that are crucial to the successful double salto backward piked dismount on the parallel bars. The subjects were 5 national gymnasts(G1: sucessed landing, G2: failed landing), two video cameras were used to record the dismount of the subjects. It summarizes that (a) It is important to make small slope angle(X axis, Y axis) at release, whereas it makes large shoulder angle and trunk rotation angle. (b) It is important to prepare landing in advance, reducing vertical velocity and making large hip angle at BTO(body take off). (c) It is also important to make small knee angle and hip angle, and reduce the angle of trunk rotation.

• 전력전자학회논문지
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• 제7권6호
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• pp.524-530
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• 2002

일상 생활에서 반사적인 자세 조절은 정전기관, 시각, 고유수용체 등의 감수체에 의한 구심성 신호가 정전 신경핵에 전달되어 안구운동이나 골격근의 수축을 유발하여 이루어진다. 자세조절기능의 부조화는 오심, 구토, 현기증 등을 초래하여 삶의 의욕을 상실하게 만든다. 본 연구의 목적은 정전기관의 반규관과 이석기관을 선별적으로 자극하기 위한 탈수직축 회전자극 시스템과 수평, 수직, 3D 환경에서 시각자극을 할 수 있는 시운동자극시스템을 개발하여 인간의 자세조절 기능을 평가 하는데 있다. 탈수직축 회전자극 시스템은 편안한 의자와 DC 서보모터로 구동되는 기울임 테이블로 구성되고 PMSM에 의해 제어된다. 그리고 속도 궤환 루프와 위치 궤환 루프를 포함하는 이중 피드백 루프가 서보 제어되는 회전자극시스템에 적용된다. HMD를 이용하여 수평, 수직, 3D 시각자극패턴을 구현 하였고 OKN 자극을 위한 무선시스템과 전기안진 기록계를 이용하여 안구운동을 기록하였다. 이득, 위상, 대칭성은 정전 자극과 시각 자극에 의해 유발되는 안구운동의 분석으로부터 얻어진다.

• 한국운동역학회지
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• 제13권3호
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• pp.81-98
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• 2003

The purpose of this study is to closely examine kinematic characteristics by jump phase of Li Xiaopeng motion in horse vaulting and provide the training data. In doing so, as a result of analyzing kinematic variables through 3-dimensional cinematographic using the high-speed video camera to Li Xiaopeng motion first performed at the men's vault competition at the 14th Busan Asian Games, the following conclusion was obtained. 1. It was indicated that at the post-flight, the increase of flight time and height and twisting rotational velocity has a decisive effect on the increase of twist displacement. And Li Xiaopeng motion showed longer flight time and higher flight height than Ropez motion with the same twist displacement of entire movement. Also the rotational displacement of the trunk at peak of COG was much short of $360^{\circ}$(one rotation) but twist displacement showed $606^{\circ}$. Likewise, Li Xiaopeng motion was indicated to concentrate on twist movement in the early flight. 2. It was indicated that at the landing, Li Xiaopeng motion gets the hip to move back, the trunk to stand up and the horizontal velocity of COG to slow down. This is thought to be the performance of sufficient landing, resulting from large security of rotational displacement of airborne and twist displacement. 3. It was indicated that at the board contact, Li Xiaopeng motion made a rapid rotation uprighting the trunk to recover slowing velocity caused by jumping with the horse in the back, and has already twisted the trunk nearly close to $40^{\circ}$ at board contact. Under the premise that elasticity is generated without the change of the feet contacting the board, it will give an aid to the rotation and twist of pre-flight. Thus, in the round-oH phase, the tap of waist according to the fraction and extension of hip joint and arm push is thought to be very important. 4. It was indicated that at the pre-flight, Li Xiaopeng motion showed bigger movement than the techniques of precedented studies rushing to the horse, and overcomes the concern of relatively low power of jump through the rapid rotation of the trunk. Li Xiaopeng motion secured much twist distance, increased rotational distance with the trunk bent forward, resulting in the effect of rushing to the horse. 5. At horse contact, Li Xiaopeng motion makes a short-time contact, and maintains horse take-off angle close to vertical, contributing to the increase of post-flight time and height. This is thought to be resulted from rapid move toward movement direction along with the rotational velocity of trunk rapidly earned prior to horse contact, and little shave of rotation axis according to twist motion because of effective twist in the same direction.