• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.25-33
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• 2012

In this study, we analyzed the effects of game-based visual feedback training on postural balance control in young adults. We provided postural balance training for four weeks in fifth minute a day and three days a week using training system of postural balance based forceplate. We evaluated the ability of postural balance using balance SD(Biodex, medicalscience Inc., USA) for the validation of game contents based visual feedback training program. The results showed that postural stability and limits of stability were improved significantly before and after the training(p<0.05). Our study indicates that postural balance training of visual feedback based game could be adapted for improving postural balance. Also, for application of this game-based visual feedback training in older adults, we could develope of various game contents for disease types and conduct quantitative analysis and data collection of postural balance in the aged.

• The Journal of the Korea Contents Association
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• v.13 no.10
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• pp.9-18
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• 2013

In this paper, we analyzed the effects of game-based visual feedback training on postural balance control in young adults and older adults. We provided postural balance training by 23 young adults and 14 older adults and for four weeks in fifth minute a day and three days a week using IBalance(Cybermedic Inc., Korea). We evaluated the ability of postural balance using balance SD(Biodex, medicalscience Inc., USA) for the validation of game contents based on visual feedback training program. The results showed that postural stability and limits of stability of young adults and older adults were improved significantly before and after the training(p<0.05). Thus, the games of postural balance encouraged anterior, posterior, medial, lateral and multidirectional weight shifting regarding postural balance. Our study indicates that postural balance training of visual feedback based game could be adapted for improving postural balance. Moreover, we could develope of game contents for individuals and various ages for effective application of this game-based visual feedback training.

• Journal of Digital Convergence
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• v.11 no.10
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• pp.549-556
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• 2013

In this study, we investigated the effects of stretching and movement with mobilization in lunge position on the muscle activity of the lower limb and limited of stability in chronic stroke patients with hemiplegia. Sixteen subjects were randomly selected and classified into the experimental and control groups. The experimental group performed self stretching exercises in the lunge position, and in the control group performed movement with mobilization in the lunge position. The interventions were conducted for 20 min, 5 times a week for 8 weeks. Statistical analyses were performed using repeated ANOVA. The analysis results showed no statistically significant between-group differences with respect to the muscle activity(%MVIC;maximum voluntary isometric contraction) of lower limb and limited of stability(LOS)(p>.05). However, statistically significant within-group differences were observed in the maximum voluntary isometric contraction and limited of stability for both the groups (p<.05). Therefore, self stretching in the lunge position is considered to have positive influences on the muscle strength and balance in stroke patients with hemiplegia.

• Journal of Astronomy and Space Sciences
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• v.15 no.1
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• pp.245-250
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• 1998

Attitude determination and control of satellite is important component which determines the accomplish satellite missions. In this study, attitude control using reaction wheels and momentum dumping of wheels are considered. Attitude control law is designed by Sliding control and LQR. Attitude maneuver control law is obtained by Shooting method. Wheels momentum dumping control law is designed by Bang-Bang control. Four reaction wheels are configurated for minimized the electric power consumption. Wheels control torque and magnetic moment of magnetic torquer are limited.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.348-356
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• 2009

The purpose of this study was to examine the effect of bridging using Swiss ball, whole body vibration (WBV), and mat on trunk and lower extremity muscle activity and postural stability. The results were as follows: 1) EMG activity of internal oblique increased significantly in WBV condition compared with mat condition (p<.05). 2) EMG activity of rectus femoris and medial gastrocnemius increased significantly in Swiss ball condition and WBV condition compared with mat condition (p<.05). 3) The muscle activity of medial hamstrings increased significantly in Swiss ball condition compared with mat condition (p<.05). 4) The limit of stability in three groups increased significantly in all directions after 4-week intervention (p<.05). 5). There were no significant differences in the limit of stability among three groups after 4-week intervention (p>.05). Therefore the trunk and lower extremity muscle activity increased in Swiss ball and WBV conditions, and postural stability was improved in three groups after intervention period.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.6 no.2
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• pp.1-8
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• 2012

In previous studies, the dynamic exercise equipment just focused on the trunk stabilization exercise. However, our study is targeted at evaluation for the impact on the postural balance of those researches. Twelve male and twelve female subjects were volunteered for the balance training using this system. They had no medical history of backpain for the past six months. Trunk Stability and postural balance training was performed for 15 minutes a day, three times a week duing four weeks. To evaluate characterization of the postural balance using Balance System SD, Evaluation consist of the postural stability test and the postural limit test. As a result, this training with 3D dynamic exercise equipment help subjects improve the postural balance. These results are expected for using basic materials to the elderly with a high risk of falling and trained athletes needed to be a postural control.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.10a
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• pp.1-3
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• 2010

수중 무인항체(Autonomous Underwater Vehicle, AUV)를 고정밀, 고위험 임무수행 분야에 이용하기 위해서는 연속적이고 정확한 항법정보를 제공하는 기술이 반드시 필요하다. 특히, 최근에는 항공분야에서 국내외적으로 연속적이고 정확한 항법정보를 제공하기 위하여 여러 가지 센서를 결합한 통합 항법시스템에 관한 연구가 활발하며, GPS나 음향장치를 관성센서와 통합하는 방법이 대표적이다. 하지만 수중 무인항체에 경우는 해수면 노출로 인한 탐사시간 장기화와 음향장치 설치 및 회수의 한계로 인하여 GPS나 음향장치 이외에 센서를 이용한 통합 항법시스템의 필요성이 커지고 있다. 본 논문에서는 자율성이 높으면서, 적은 비용으로 설치가 가능한 영상센서를 이용하여 항법성능을 효과적으로 증대시키는 Vision/INS 통합 항법을 제안한다. 제안한 통합 항법알고리즘은 외부표정요소 직접결정기법을 이용하여 영상 데이터로부터 항체의 위치와 자세를 추정하고, 추정된 결과를 INS의 추정치와 비교한다. 그리고 추정한 위치와 자세오차를 입력으로 칼만필터를 구동하도록 설계하였다. 모의실험을 통해 제안한 방법의 유효성을 확인하였다.

• Proceedings of the ESK Conference
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• 1995.04a
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• pp.51-51
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• 1995

인체 CAD 모델링 시스템은 장비와 인체를 모델링하여설계 초기단계에서 부터 별도의 Mock-up 없이 전 벙위의 운용자에 대한 작업자세의 안락도(Comfort), 동작한계(Reach), 적 합성(Fit), 시계(Vision)등 제반 작업공간 설계 및 평가에 수반되는 고려요소들을 보다 과학적 이고 합리적으로 반영할 수 있는 도구로 인식되고 있다. 본 연구는 크게 한국군 전차병의 인체 CAD 모델의 설계와 설계된 인체 모델을 활용한 한국형 전차 작업공간 평가로 구성되었다. 한국 군 전차병의 인체 CAD 모델링에서는 전차병의 인체 측정자료를 이용하여 5%, 50%, 95%치 전차병 에 대한 선 자세와 앉은 자세의 인체 모델을 설계하였으며, 보다 정확한 인체 모델의 구현을 위 해인체의 기능적 치수에 대한 실측치와 CAD 설계치와의 차이를 비교, 보정하여 줌으로써 작업공 간 평가시 보다 정확한 결과를 얻을 수 있도록 하였다. 한국형 전차 작업공간 평가에서는 설계 된 인체 모델과 한국형 전차 주요 구성품의 CAD 모델을 활용하여 각 승무원의 작업역을 분석하였고, 승무원 해치, 주요 조종장치의 운용 적합성, 판넬류 등의 위치 적합성에 대해 분석, 평가하였다. 본 연구를 통해 무기체계를 대상으로 하여 CAD 프로그램을 이용한 Man-Machine Interface에 대한 검토가 이루어 졌으며, 기존의 도면이나, Mock-up, Prototype에 의존하던 작업공간 타당성 검토가 CAD를 이용하여 3차원적으로 이루어 질 수 있는 기반을 마련하였다는데 의의가 있다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.3
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• pp.217-224
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• 2020

The use of a high gain flight control system to achieve high bandwidth performance increase the instability of a helicopter. To investigate these phenomena numerically, high fidelity EC155B1 helicopter model and simplified flight control system that include actuator, digital processor and noise rejection filter was developed. A study conducts an analytical investigation of roll axis stability of the helicopter model as feedback gain increases. And this study analyzes roll-rate and roll-attitude feedback gains limited by rotor flap mode. The results indicate that the phase delays caused by the filter can severely limit the usable values of the roll-rate and roll-attitude feedback gains.

• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.115-122
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• 2023

The hip joint device is an important immobilization device for internal rotation in the diagnosis of bone density test, microfracture, and arthritis. These fixing mechanisms have limitations in maintaining reproducibility due to the use of Velcro. In this study, we developed an improved hip joint device and evaluated its usefulness. For 30 students enrolled in the Department of Radiology, we evaluated the reproducibility through medical imaging and the time required for positioning by applying the conventionaling and improved device. Changes over time were also evaluated. As a result, compared to the conventional device, the improved device showed a 32% reduction in positioning time and improved reproducibility by about 6.2 times. As for the amount of change over time, the positioning time increased in the conventional device, but decreased in the improved device, and the reproducibility of the conventional device was lower than that of the improved device. Through this, it can be said that the use of the improved device improved the image quality and reduced the radiologist's workload.