• 한국기계가공학회지
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• 제20권9호
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• pp.97-103
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• 2021

In this paper, an omni wheel-based electric wheelchair is proposed that can achieve safe and convenient movement and can improve the convenience of living for mobility-impaired people who cannot move on their own. Generally, mobility-impaired people are afflicted with physical health issues such as pain and secondary body deformities because they often remain seated in wheelchairs for long periods of time. Hence, an electric wheelchair is required whose posture can be changed and whose size can be adjusted according to the user's body type. Such a wheelchair should also facilitate easy change of direction (even in a narrow space) for convenient movement. In this paper, an electric wheelchair featuring omni wheels is proposed that allows posture transformation and facilitates movement in a narrow space. It is believed that the proposed wheelchair can aid in enhancing the convenience of living for mobility-impaired people.

• 한국항해항만학회지
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• 제28권6호
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• pp.469-474
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• 2004

본 논문에서는 비 홀로노믹적인 구속조건을 갖는 수중 이동체의 위치 및 자세제어에 관한 제어기법에 대해서 논의한다. 비 홀로노믹시스템은 적분 불가능한 구속조건으로부터 도출되어지는 시스템으로 연속시간영역의 피드백제어로는 평형점에서의 안정화제어가 불가능한 특성을 가지고 있다. 본 연구에서는 속도의 비 홀로노믹 구속조건을 가지는 수중 이동체에 대하여 체인드폼으로 변환하고 변환된 시스템에 대해 백스테핑 제어기법을 적용하여 자세제어를 행하였으며 수치시뮬레이션을 통하여 제어기법의 유용성을 평가하였다.

• 융합신호처리학회논문지
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• 제24권1호
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• pp.15-20
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• 2023

일반적으로 잘못된 앉은 자세를 장시간 유지하는 것은 척추에 나쁜 영향을 미치는 것으로 널리 알려져 있다. 최근 여러 연구자들이 잘못된 앉은 자세와 척추질환의 인과관계에 관심을 두고 있으며, 척추질환 예방을 위해 앉거나 서는 자세의 변화를 정밀하게 측정할 수 있는 방법을 연구해왔다. 우리는 과거 연구에서 실시간 체위 변환 측정이 가능한 센서 디바이스를 개발하고 운동량 계산 알고리즘을 적용하여 실시간 자세 전환 측정 정확도를 향상시켰으며, 체위 변환 측정 센서의 정확도를 검증하였다. 본 연구에서는 좌압 측정을 통해 체중심의 변화를 고려한 자세 측정 및 분석 장치를 개발하였으며, 개발된 센서는 사용자의 시각적 피드백을 개선하여 자세 교정 훈련 정확도를 높이는 보조 도구로의 활용 가능성을 확인하였다.

• 국제물리치료학회지
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• 제6권2호
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• pp.871-877
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• 2015

This research was conducted to investigate the effect of continuous antagonistic muscle strengthening exercise and Evjenth-Hamberg stretching on the pulmonary function of university students with abnormal transformation of forward head posture(FHP). The results of study subject to the continuous antagonistic muscle strengthening(CAS) group(n=10) and Evjenth- Hamberg stretching(EHS) group(n=10) that was conducted 3 times a week for 6 weeks are as follow. FVC, IVC, and MVV all were shown to be significant in the pre post comparison between the CAS group and EHS group(p<.05), and significant difference was shown for MW between the two groups(p<.05) in which the CAS group showed better effect. Based on the results above, it is considered that combining continuous antagonistic muscle strengthening exercise has better effect on pulmonary function compared to application of only Evjenth-Hamberg stretching.

• 국제물리치료학회지
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• 제4권2호
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• pp.633-639
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• 2013

This study aims to reveal the impact of continuous antagonist strengthening(CAS) and Evjenth-Hamberg stretching(EHS) on the cervical mobility in the university students with abnormal transformation of forward head posture(FHP). Our experiment was conducted 3 times a week for 6 weeks in a total of 20 individuals : continuous antagonist strengthening(CAS) group(n=10) & Evjenth-Hamberg stretching(EHS) group(n=10). In a pre and post comparison, both CAS group and EHS group appeared significantly in mSBI and SBA(p<.05) and the two-group comparison showed a significant difference(p<.05) : CAS group showed better effects. Thus, it is considered that the combined use with continuous antagonist strengthening(CAS) had better effects for cervical mobility than Evjenth-Hamberg stretching(EHS) alone.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 춘계학술대회
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• pp.510-511
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• 2017

본 논문에서는 척추 관련 질환을 예방하고, 잘못된 자세를 사용자에게 피드백하여 자세교정에 도움을 주기 위한 연구를 수행하였다. 이를 위해 키넥트 센서를 사용하였으며, 사용자의 움직임을 측정하기 위해 골격 데이터 좌표 값을 인덱스 화하여 움직임 변화정도를 측정하였다. 구현된 시스템은 자세판별 뿐만 아니라 사용자의 산만도 모니터링이 가능함을 확인하였다.

• 전기학회논문지
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• 제65권10호
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• pp.1746-1754
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• 2016

In this paper, we provide a development and evaluation method for an archery posture analyzing system, using an inertial sensor. The system was developed using LabVIEW2014 by National Instruments and evaluated using the DTW algorithm. To convert the voltage value of the inertial sensor into a physical value, a coordinate transformation matrix bias was applied. To evaluate the similarity of movement in archery shooting, the DTW distance was calculated and similarity was confirmed based on simple mechanical movement, the same person's shooting movement, shooting movement with another person, and the noise signal. The average similarity comparison results were as follows: simple mechanical movement was 17.05%, the same person's shooting movement was 26.48%, shooting movement with another person was 62.8%, and the noise signal was 328.5%; a smaller value indicates a higher level of similarity. We confirmed the possibility of analyzing the archery posture using 3-axis acceleration of the inertial sensor. We inferred that the proposed method might be important means for assessing shooting skills, evaluation of archer's progress, and finding talented archers in advance.

• 한국정밀공학회지
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• 제21권4호
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• pp.120-131
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• 2004

In this paper, we propose the method of a motion planning generation in which the movement of the 3-link leg subsystem is constrained to a slider-link and a singular posture can be easily avoided. The proposed method is the jumping control moving in vertical direction which mimics a cat's behavior. That is, it is jumping toward wall and kicking it to get a higher-place. Considering the movement from the point of constraint mechanical system, the robotic system which realizes the motion changes its configuration according to the position and it has several phases such as; ⅰ) an one-leg phase, ⅱ) in an air-phase. In other words, the system is under nonholonomic constraint due to the reservation of its momentum. Especially, in an air-phase, we will use a control method using state transformation and linearization in order to control the landing posture. Also, an iterative learning control algorithm is applied in order to improve the robustness of the control. The simulation results for jumping control will illustrate the effectiveness of the proposed control method.

• 한국인터넷방송통신학회논문지
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• 제14권5호
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• pp.131-135
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• 2014

본 논문은 상체움직임을 통하여 자세기능의 변화를 나타냈다. 자세의 기능은 상체의 움직임 변화에 따라 자세의 방향성을 분석하였다. 측정항목은 균형시스템에 따라 자세에 대한 평가로 활용하였다. 중추신경은 $0.226{\pm}0.04$의 변화가 발생하였고, 체성감각은 $0.939{\pm}0.46$의 변화, 전정기관은 $4.009{\pm}1.05$이고, 시각은 $8.336{\pm}4.05$로 변화가 나타났다. 본연구의 결과로 상체움직임에 따른 시각적 변화에 미세하게 영향으로 나타났고, 중수신경의 변화에도 다소 변화가 나타남으로 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.230-233
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• 1993

This paper described a relationship between motion speed and working accuracy of industrial articulated robot arms. Working accuracy of the robot arm deteriorates at high speed operation caused by a nonlinear transformation of the kinematics and the time delay of the robot arm dynamic. The deterioration of the following trajectory was expressed as a linear function of the squares of the robot arm motion speed, depending upon a posture of the robot arm and division interval of the objective trajectory.