• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.507-510
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• 2003

In this paper, optical sensor system using PSD(Position Sensitive Detection) is proposed to obtain the three dimensional position of moving markers attached to human body. To find the coordinates of an moving marrer with stereo vision system, two different sight rays of an moving marker are required. Usually, those are acquired with two optical sensors synchronized at the same time. PSD sensor is used to measure the position of an incidence light in real-time. To get the three-dimension position of light source on moving markers, a conventional camera calibration method are used. In this research, we realized a low cost motion capture system. The proposed system shows high three-dimension measurement accuracy and fast sampling frequency.

• 정보처리학회논문지B
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• 제9B권4호
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• pp.453-458
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• 2002

빠른 변화를 가지는 운동 동작을 분석하는 것은 쉬운 일이 아니다. 그러나 이를 동영상으로 취득하여 동영상 파일을 분석하는 것은 쉬운 일이다. 더욱이 PC의 보급과 디지털 캠코더의 보급으로 동영상 파일의 취득이 용이해 짐에 따라 일반인도 손쉽게 동영상 분석을 할 수 있는 환경을 가지게 죄었다. 본 연구에서는 골프 동작을 동영상 파일에 담아 분석할 수 있는 시스템을 설계하고 이를 구현하여 보았다. 또한 영상 흐름을 반영할 수 있는 편집 방식을 개발하고 이동 추적 알고리즘을 사용하여 골프 스윙 분석을 보다 용이하게 개선하였다.

• 한국운동역학회지
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• 제22권1호
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• pp.123-129
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• 2012

Simple camera-based system for evaluation of lower limb alignment as a part of an automated cycling fitting system was developed and verified in this study. Developed imaging system can evaluate lower limb alignment quantitatively during pedaling using a general camcorder and single marker attached on the knee. Threshold-based marker detection algorithm was proposed in this study. Experiment was carried out to compare the trajectory data from marker detection algorithm of the developed imaging system with the trajectory data from 3-D motion capture system. Results showed that average error between trajectories was 2.33 mm (0.92 %) in the vertical direction and 0.62 mm (1.86 %) in the medio-lateral direction. There existed significant correlation between two measured values (r=0.9996 in the vertical direction and r=0.9975 in the medio-lateral direction). It can be concluded that developed imaging system be applied to evaluate lower limb alignment which is an important factor for dynamic bicycle fitting.

• 한국의류산업학회지
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• 제17권5호
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• pp.844-853
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• 2015

Recently, according to change of lifestyle and increase of concerning in health, needs of the smart clothing based on the vital sign monitoring have increased. Along with this trend, smart clothing for ECG monitoring has been studied various way as textile electrode, clothing design and so on. Smart clothing for ECG monitoring can become a comfortable system which enables continuous vital sign monitoring in daily use. But, smart clothing for ECG monitoring has a weakness on artifact during motion. One of the motion artifact caused by shifting of the electrode position was affected skin change by motion. The aim of this study was to suggest electrode locations for clothing of ECG monitoring to reduce of motion artifacts. Therefore, change of skin surface during the movement were measured and analyzed in order to find location to minimize motion artifacts in ECG monitoring clothing by 3D motion capture. For the experiment, the subjects consisted of 5 males and 5 females in their 20' with average physique. As a result, the optimal location for ECG monitoring was deducted under the bust line and scapula which have least motion artifact. These locations were abstracted to be least affected by movement in this research.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제10권6호
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• pp.181-190
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• 2021

여러 명이 모여서 진행되는 스포츠 활동은 코로나19와 같이 광범위하게 유행하는 전염병이 퍼지는 상황에서는 진행되기 어려우며, 이로 인해 현대인의 신체 활동 부족이 발생한다. 비대면으로 진행되는 운동 콘텐츠들을 이용하면 이런 문제점을 극복할 수 있지만, 대면 운동 시와 같은 세밀한 자세 확인이 어렵다. 본 연구에서는 보다 나은 비대면 운동 콘텐츠 운영을 위해서 IT 시스템에서 자세를 감지하고 움직임을 추적하는 모델을 제시한다. 제안하는 움직임 추적 모델은 체육학에서 널리 사용되는 움직임 분석 방법들을 참고하여 신체 모델을 정의하고 이에 따른 자세 및 움직임을 정의한다. 제안한 모델을 사용하면 운동에 쓰이는 움직임을 인식하고 분석할 수 있으며 운동 프로그램에서 특정 움직임의 횟수를 알 수 있고, 운동프로그램 수행 여부 감지도 가능하다. 제안한 모델의 유효성을 확인하기 위해 마커리스 모션 캡쳐 장비인 Azure Kinect DK를 사용하여 움직임 추적, 그리고 운동 프로그램 추적 프로그램을 구현하였다. 제안된 움직임 분석 모델을 개선하고 모션 캡쳐 시스템의 성능을 높인다면 보다 세밀한 움직임 분석이 가능하며, 적용할 수 있는 운동의 종류를 늘릴 수 있다.

• 한국항해항만학회지
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• 제48권2호
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• pp.116-124
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• 2024

Automatic docking of small planing ship is a critical aspect of maritime operations, requiring accurate prediction of motion states to ensure safe and efficient maneuvers. This study investigates the use of Artificial Neural Network (ANN) to predict motion state of a small planing ship to enhance navigation automation in port environments. To achieve this, simulation tests were conducted to control a small planing ship while docking at various heading angles in calm water and in waves. Comprehensive analysis of the ANN-based predictive model was conducted by training and validation using data from various docking situations to improve its ability to accurately capture motion characteristics of a small planing ship. The trained ANN model was used to predict the motion state of the small planning ship based on any initial motion state. Results showed that the small planing ship could dock smoothly in both calm water and waves conditions, confirming the accuracy and reliability of the proposed method for prediction. Moreover, the ANN-based prediction model can adjust the dynamic model of the small planing ship to adapt in real-time and enhance the robustness of an automatic positioning system. This study contributes to the ongoing development of automated navigation systems and facilitates safer and more efficient maritime transport operations.

• PNF and Movement
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• 제18권2호
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• pp.287-296
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• 2020

Purpose: The study aims were to develop a wearable inertial sensor-based gait analysis device that uses machine learning algorithms, and to validate this novel device using temporal gait parameters. Methods: Thirty-four healthy young participants (22 male, 12 female, aged 25.76 years) with no musculoskeletal disorders were asked to walk at three different speeds. As they walked, data were simultaneously collected by a motion capture system and inertial measurement units (Reseed®). The data were sent to a machine learning algorithm adapted to the wearable inertial sensor-based gait analysis device. The validity of the newly developed instrument was assessed by comparing it to data from the motion capture system. Results: At normal speeds, intra-class correlation coefficients (ICC) for the temporal gait parameters were excellent (ICC [2, 1], 0.99~0.99), and coefficient of variation (CV) error values were insignificant for all gait parameters (0.31~1.08%). At slow speeds, ICCs for the temporal gait parameters were excellent (ICC [2, 1], 0.98~0.99), and CV error values were very small for all gait parameters (0.33~1.24%). At the fastest speeds, ICCs for temporal gait parameters were excellent (ICC [2, 1], 0.86~0.99) but less impressive than for the other speeds. CV error values were small for all gait parameters (0.17~5.58%). Conclusion: These results confirm that both the wearable inertial sensor-based gait analysis device and the machine learning algorithms have strong concurrent validity for temporal variables. On that basis, this novel wearable device is likely to prove useful for establishing temporal gait parameters while assessing gait.

• 한국운동역학회지
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• 제28권1호
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• pp.1-8
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• 2018

Objective: The purpose of this study is to investigate the differences in biomechanical variables of golf driving motion according to gender. Method: A total of 21 healthy golfers (11 men and 10 women) who have more than 5 years of professional experience and have been registered in the Korea Golf Association was recruited. A 250-Hz 8-camera motion capture system (MX-T20, Vicon, LA, USA) was used to capture the motion trajectories of a total of 42 reflective markers attached to the golfer's body and club. Moreover, two 1,000-Hz AMTI force plates (AMTI OR6-7-400, AMTI, MA, USA) were used to measure the ground reaction force. The mean and standard deviation for each parameter were then calculated for both groups of 21 subjects. SPSS Windows version 23.0 was used for statistical analysis. The independent t-test was used to determine the differences between groups. An alpha level of .05 was utilized in all tests. Results: There were differences in joint angles according to gender during golf driver swing. Men showed a statistically significantly higher peak joint angle and maximum range of angle in sagittal and frontal axis of the pelvis, hip, and knee. Moreover, women's swing of the pelvis and hips was found to have a pattern using the peak joint angle and range of angle in the vertical axis of the pelvis and hip. There were the differences in peak joint moment according to gender during golf driver swing. Men used higher joint moment in the downswing phase than women in the extensor, abductor, and external rotator muscles of the right hip; flexor and adductor muscles of left hip joint; and flexor and extensor muscles of the right knee. Conclusion: This result reveals that male golfers conducted driver swing using stronger force of the lower body and ground reaction force based on strength of hip and thigh than female golfers.

• 한국컴퓨터그래픽스학회논문지
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• 제8권3호
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• pp.17-23
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• 2002

영화, 게임, 방송 등의 엔터테인먼트 산업에서 캐릭터 애니메이션에 대한 요구가 증가함에 따라 이를 제작하는 스튜디오에서 모션갭처 장비의 도입을 통해 애니메이션 데이터를 제공하는 사례가 급속히 증가하고 있다. 하지만, 상용 장비들은 고가의 비용 부담으로 인해 엔터테인먼트 산업의 전반적인 매출의 수익창출에 저해요인이 되고 있다. 이러한 배경에서 KAIST VR Lab 에서는 지난 수 년간 저가형 광학식 모션캡처 시스템을 개발하여 왔다. 저가형 시스템을 이용한 경우 마커의 은닉(occlusion), 잡음(noise) 또는 궤적 뒤바뀜(swapping) 등의 이유로 고가의 장비를 사용할 때에 비해 더 많은 후처리 작업을 요한다. 본 논문에서는 이와 같은 문제를 해결하기 위해 인체에 부착된 마커를 그래프 구조로 정의하고 신뢰도 모델을 제시하여 포착된 프레임의 신뢰성을 측정한다. 이러한 신뢰도 모델을 통해 마커의 궤적 재조정(rectification) 알고리즘을 제안한다.

• 한국컴퓨터그래픽스학회논문지
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• 제6권3호
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• pp.9-15
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• 2000

본 논문에서는 모션 캡쳐 시스템을 위한 센서 퓨전 방법을 제안한다. 제안된 시스템에서는 두가지 종류의 센서가 상호보완적으로 사용된다. 연기자의 팔에 부착된 12개의 광학식마커를 보조하기 위해서 4개의 자기식 센서(마커)가 팔 상박과 손등에 부착된다. 광학식 마커는 장애물에 의하여 가려질 수 있기 때문에 광학식 센서의 정보는 불완전할 수 있으며 이 경우 자기식 센서 정보가 불연속인 광학식 센서의 정보를 이어주는데 사용된다. 센서 신호간의 관계를 모델링하기 위해 시스템 동정화 방법을 사용한다. 입 출력 데이터로부터 동적 시스템들을 구성하고 시스템 동정화 방법을 사용하여 후보 모델들로부터 가장 좋은 모델을 결정한다. 제안된 방법은 현재 간단한 신호처리 기법을 사용하고 있는데, 추후 연구에선 Wiener나 Kalman 필터를 사용한 새로운 방법을 제안하고자 한다.