• 스마트미디어저널
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• 제9권4호
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• pp.97-101
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• 2020

본 연구에서는 센서상의 전하량 변화를 통하여 전위차를 측정할 수 있는 수동형 전기장센서를 이용하여 사람의 손동작에 의해 유발되는 신호를 측정 장치의 전원이나 주변 전력선에 의해 센서에 유입되는 잡음(PLN: Power Line Noise)의 고조파 성분을 분석하여 동작신호를 검출하고 추출하는 연구를 수행 한다. 전기장 센서에 유입되는 전력선잡음으로 센서가 사람의 존재, 접근, 동작에 의해 영향 받는 사실을 이용해 PLN의 주성분인 60Hz 고조파 성분의 스펙트럼분석을 수행하여 PLN 신호의 증가 또는 감소를 식별할 수 있고 상대적으로 동작에 민감한 120Hz 성분을 이용한다. FFT를 사용하여 120Hz의 신호성분이 특정 임계값을 통과할 때 신호를 검출하는 방법이다. 동작이 탐지되는 경우 임계값을 기준으로 프레임을 결정한다. 본 연구의 방법을 이용하여 얻은 동작 감지 성공률은 약 90% 수준을 달성하였다. 이렇게 감지된 동작신호로 추출한 프레임의 정확도는 약 85%이다. 수동형 전기장 센서를 이용하여 동작신호를 PLN을 이용하여 동작검출에 이용한 연구사례는 국내외적으로 드문 사례이며, 본 논문에서는 PLN이 상존하는 실내 적용환경에서 유망하게 활용될 수 있다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2019년도 춘계학술대회
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• pp.486-487
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• 2019

스마트폰에는 다양한 센서가 내장되어 있다. 특히 가속도 센서는 물체의 움직임을 파악할 수 있기 때문에 사람의 행동을 분석하는데 많이 사용된다. 기존의 연구들은 가속도센서의 값의 크기를 분석하여 사람의 행동을 분석하였다. 본 연구에서는 스마트폰에 내장된 가속도 센서의 값을 K-평균을 적용하여 움직임을 파악하는 방법을 제안하였다. 스마트폰의 가속도센서의 값을 K-평균을 적용하여 사람의 기본적인 행동인 걷기와 달리기를 인식하기 방법을 제안하였다.

• Journal of Biosystems Engineering
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• 제22권4호
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• pp.411-420
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• 1997

The mechanization efficiency using high ability machines such as tractors or combines in a paddy field rice farm is high. Mechanization in harvesting fruits and vegetables is difficult, because they are easy to be damaged. Therefore, Advanced techniques for careful handling fruits and vegetables are necessary in automation and robotization. An apple harvesting robot must have a recognition device to detect the positioning of fruit, manipulators which function like human arms, and hand to take off the fruit. This study is related to the development of a rotatic hand as the first stage in developing the apple harvesting robot. The results are summarized as follows. 1. It was found that a hand that was eccentric in rotatory motion, was better than a hand of semicircular up-and-down motion in harvesting efficiency. 2. The hand was developed to control changes in grasp forces by using tape-type switch sensor which was attatched to fingers' inside. 3. Initial finger positioning was set up to control accurate harvesting by using a tow step fingering position. 4. This study showed the possibility of apple harvesting using the developed robot hand.

• 한국멀티미디어학회논문지
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• 제11권11호
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• pp.1491-1500
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• 2008

본 논문은 은닉 마르코프 모델을 사용하여 사람의 특정한 행동을 인식하여 사용자에게 알려주는 지능형 영상 감시 시스템을 제안한다. 본 방법에는 카메라를 통해 입력된 영상에서 사람 영역을 찾은 후 발 영역만을 추출하여 특징이 되는 관측열을 생성한다 특징 영역은 입력 영상의 각 프레임을 16개의 영역으로 나누어 발바닥이 위치한 곳의 코드를 읽어 사용하고, 인식하고자 하는 패턴 행동들에 대해서는 각각의 관측열을 구하고 HMM의 Baum-Welch 알고리즘을 사용하여 학습한다. 인식에는 전향 알고리즘을 사용하여 입력된 행동과 학습된 행동을 확률적으로 비교하여 영상 내의 행동이 어떤 패턴 행동인지를 결정하여 출력한다. 제시된 방법은 복도에서 사람의 특정 행동을 인식하는데 성공적으로 적용될 수 있음을 실험을 통해 확인했다.

• 한국전기전자재료학회논문지
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• 제30권6호
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• pp.366-371
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• 2017

In this paper, we introduce an electrocardiogram (ECG) system designed to solve problems caused by wetgels and motion artifacts in measuring active movement. The system is called a dry-contact ECG and was designed by considering impedance matching between skin and electrode as well as the frictional electricity between electrode and clothes. In order to create the system, we measured impedance on the skin-electrode interface, and the result was applied to the electronic circuit scheme. Moreover, we added an electrode on the back of the measurement electrode to make a flow path to ground the electrical noise. The final ECG circuit and novel electrode were used to detect real human cardiac signals from a subject who was tested while standing still and walking. The signals obtained from the two activities were nicely shaped, without any motion artifact noise. We took electrode size into account in this study because the impedance depended on the area of the electrode. An electrode of 50 mm diameter showed the best curve for the ECG signal without any electrical noise.

• Journal of Advanced Marine Engineering and Technology
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• 제36권5호
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• pp.674-682
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• 2012

A new intelligent stereo vision sensor system was studied for the motion and depth control of unmanned vehicles. A new bottom-up saliency map model for the human-like active stereo vision system based on biological visual process was developed to select a target object. If the left and right cameras successfully find the same target object, the implemented active vision system with two cameras focuses on a landmark and can detect the depth and the direction information. By using this information, the unmanned vehicle can approach to the target autonomously. A number of tests for the proposed bottom-up saliency map were performed, and their results were presented.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.501-504
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• 2006

The estimation of the work of heart can be treated as one of the most important parameters for determining the amount of circulating blood needed for harmonious metabolism in the human body. By monitoring the work of heart, one can detect increased work load of heart and start the treatment at the early stage of CHF. Thus it is necessary to estimate the work of heart. The contractility of the left ventricle, the second important parameter for representing the motion of heart, can be estimated through information on the work of heart. In this study, the modified Windkessel model, which has been used for a measure of vascular hemodynamic impedance parameters, was adapted to estimate the work of heart.

• 한국멀티미디어학회논문지
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• 제7권6호
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• pp.767-780
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• 2004

Interaction requires dynamic relationship between objects. In ubiquitous computing environment, interaction between human and the environment is implied. Tactile interaction has so far been less addressed, while tactile sensation should be an important topic in the field of multimedia study. This paper describes development of a novel PVDF (Polyvinylidene Fluoride) dynamic tactile sensor and associated experiments. PVDF dynamic tactile sensors detect touch events applied to the sensor skin by low frequency components of the signal. Rubber skin-covered sensing material was mounted on the bones. Robust performance with low noise was figured out in our robotic experiment. Whereas most conventional sensors are interested in measurement, our dynamic tactile sensor is sensitive to change of state, which could be a key for economic understanding of happenings in the dynamic world. We note that dynamic sensing uses motion as a part of sensing modality We suggest that dynamic sensing be understood in technological terms in the perspective of interactive media and ubiquitous computing.

• 한국기계가공학회지
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• 제21권6호
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• pp.22-29
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• 2022

In this study, an automatic marking system for fabric inspection machines was developed. The main objectives of the study were to promote intelligence and automation for the inspection process, as well as to increase textile industrial productivity. Generally, when a worker manually inspects and marks a fabric, human error and reduced efficiency are unavoidable. To overcome these problems, we developed an automatic marking system that uses robots. This system incorporates a vision camera to automatically recognize defects, and an optical fiber sensor to detect the side of the fabric. To verify the performance, the control system sends a command directly to the robot to mark the fabric. Finally, the actual production confirmed that the proposed system could perform the desired motion.

• Journal of information and communication convergence engineering
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• 제15권4호
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• pp.244-249
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• 2017

Wearable sensor-based gait analysis has been widely conducted to analyze various aspects of human ambulation abilities under the free-living condition. However, there have been few research efforts on using wearable sensors to analyze human walking on an unstable surface such as on a ship during a sea voyage. Since the motion of a ship on the unstable sea surface imposes significant differences in walking strategies, investigation is suggested to find better performing wearable sensor-based gait analysis algorithms on this unstable environment. This study aimed to compare two representative gait event algorithms including time domain and frequency domain analyses for detecting heel strike on an unstable platform. As results, although two methods did not miss any heel strike, the frequency domain analysis method perform better when comparing heel strike timing. The finding suggests that the frequency analysis is recommended to efficiently detect gait event in the unstable walking environment.