• Proceedings of the IEEK Conference
• /
• 2009.05a
• /
• pp.360-362
• /
• 2009

In this paper, we studied for the real-time azimuthal measurement of HMD(Head Mounted Display) using the feature points detection to control the tele-operated vision system on the mobile robot. To give the sense of presence to the tele-operator, we used a HMD to display the remote scene, measured the rotation angle of the HMD on a real time basis, and transmitted the measured rotation angles to the mobile robot controller to synchronize the pan-tilt angles of remote camera with the HMD. In this paper, we suggest an algorithm for the real-time estimation of the HMD rotation angles using feature points extraction from pc-camera image.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2008.04a
• /
• pp.199-200
• /
• 2008

머리의 자세 및 움직임 추적은 응시추적 및 시각운율 연구에서 필수적이다. 일반적으로 머리자세를 추정하는 방법은 보정된 카메라를 통해 추출된 얼굴의 특징점 정보를 이용한다. 그러나 실제 응용 분야에서는 보정되지 않은 카메라를 통한 머리 움직임을 추정해야 할 경우가 발생한다. 이에 따라 본 논문에서는 보정되지 않은 하나의 카메라를 이용, 단일특징점 정보를 이용한 머리 자세 추정 방법을 확장하여 최적화 기법을 도입한 다특징점 정보 기반 머리 자세 추정방법에 대하여 논하였다.

• Journal of Korea Multimedia Society
• /
• v.11 no.6
• /
• pp.787-795
• /
• 2008

Human recognition on camera is an interesting topic in computer vision. While fingerprint and face recognition have been become common, gait is considered as a new biometric feature for distance recognition. In this paper, we propose a gait recognition algorithm based on the knee angle, 2 feet distance, walking velocity and head direction of a person who appear in camera view on one gait cycle. The background subtraction method firstly use for binary moving object extraction and then base on it we continue detect the leg region, head region and get gait features (leg angle, leg swing amplitude). Another feature, walking speed, also can be detected after a gait cycle finished. And then, we compute the errors between calculated features and stored features for recognition. This method gives good results when we performed testing using indoor and outdoor landscape in both lateral, oblique view.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.11 no.4
• /
• pp.445-451
• /
• 2018

In this paper, we propose an HMD-AR interaction system that combines optical camera communication to provide location-based service for tourists in Jeonju Hanok Village. The proposed system receives optical camera communication data from Light infrastructure existing in Jeonju Hanok Village and provides service through ID information along with its own location information. We researched optical camera communication technology and smart device based HMD-AR system and constructed the actual HMD-AR system and tested it. The proposed system is expected that it will be applied to various tourist attractions by utilizing the proposed system in the future, and it is expected to be used as a valuable feedback for smart device based HMD-AR.

• PNF and Movement
• /
• v.18 no.1
• /
• pp.45-53
• /
• 2020

Purpose: This study investigated the correlation between standing balance and head-forward posture in adolescents. Methods: The participants in this study were 15 female adolescents. We took photographs of the participants' craniovertebral angle with a digital camera to determine the degree of head-forward posture. Standing balance was evaluated using the 30-second Romberg test of BT4. The measurements were taken on a stable-support surface and on an unstable-support surface using a balance pad. The data measured in this study were analyzed using SPSS version 23.0, and the statistical significance level α was established as 0.05. Pearson correlation coefficient analysis was performed to identify the correlation between the degree of head-forward position of the participants and their balance ability. Results: When we measured 30 seconds of the Romberg test, we observed that, with their eyes open, the participants' head-forward posture and balance were not correlated. However, with their eyes closed, there was a strong correlation between the forward position of the head and the balance ability, which declined as the head position increased. Conclusion: Adolescents with severe head-forward posture exhibited problems with balance in posture control with closed eyes when visual information was not available. It can be inferred that an abnormality occurs in proprioceptor sensation due to their habitual head-forward posture. Education on correct posture and preventive activities should be recommended to improve the health of such adolescents and avoid possible future problems of physical deterioration.

• Journal of Institute of Control, Robotics and Systems
• /
• v.15 no.3
• /
• pp.265-272
• /
• 2009

In this paper, a simple optical method that uses an infrared(IR) cut filter is proposed to minimize variation of eye image by external infrared(IR) sources in a video based head mounted eye tracking system that is used in the field of sports. For this, the IR cut filter is attached to a head mount of the eye tracking system, and the camera with an IR LED is located between the IR cut filter and eye. In this structure, external IR is blocked by the IR cut filter, and the IR intensity on the eye can be controlled by the IR LED. Therefore, the illumination condition of the camera to capture the eye can be stable without being affected by external IR illuminations. To verify the proposed idea, variation of the eye image and intensity of the IR with/without the IR cut filter is measured under various illumination conditions. The measured data show that the IR cut filter method can block external IR effectively, and complex pupil detection algorithms can be replaced by a simple binarized method.

• Transactions on Control, Automation and Systems Engineering
• /
• v.3 no.4
• /
• pp.229-235
• /
• 2001

Recently, service area has been emerging field f robotic applications. Even though assistant robots play an important role for the disabled and the elderly, they still suffer from operating the robots using conventional interface devices such as joysticks or keyboards. In this paper we propose an efficient computer interface using real-time eye-gaze tracking system. The inputs to the proposed system are images taken by a camera and data from a magnetic sensor. The measured data is sufficient to describe the eye and head movement because the camera and the receiver of a magnetic sensor are stationary with respect to the head. So the proposed system can obtain the eye-gaze direction in spite of head movement as long as the distance between the system and the transmitter of a magnetic position sensor is within 2m. Experimental results show the validity of the proposed system in practical aspect and also verify the feasibility of the system as a new computer interface for the disabled.

• 한국가시화정보학회:학술대회논문집
• /
• 2007.11a
• /
• pp.128-133
• /
• 2007

An electrostatic inkjet head can be used for manufacturing processes of large display systems and printed circuit boards (PCB) as well as inkjet printers because an electrostatic field provides an external force which can be manipulated to control sizes of droplets. The existing printing methods such as thermal bubble and piezo inkjet heads have shown difficulties to control the ejection of the droplets for printing applications. Thus, the new inkjet head has been proposed using the electrostatic force. A numerical analysis has been performed to calculate the intensity of the electrostatic field using the Maxwell's equation. Also, experiments have been carried out to investigate the droplet movement using a downward capillary with outside diameter of $500{\mu}m$. Gravity, surface tension, and electrostatic force have been analyzed with high voltages for a drop-on-demand ejection. It has been observed that the droplet size decreases and the frequency of the droplet formation and the velocity of the droplet ejection increase with increasing the intensity of the electrostatic field using high-speed camera.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.10 no.7
• /
• pp.793-800
• /
• 2015

We presented a method to perform simultaneously both head-eye calibration and wheel calibration for a mobile robot that has a stereo camera mounted on the pan-tilt mechanism. Such a mobile robot system prevails recently. However, conventional methods are not applicable to this system because they assumed that camera systems were mounted on fixed structures. Building on conventional methods, we devised an iterative linear solution to solve the problem, and achieved satisfactory results in terms of accuracy in addition to efficiency due to simultaneous calibration. Furthermore, the calibration accuracy was improved by nonlinear optimization.

• PNF and Movement
• /
• v.19 no.2
• /
• pp.163-172
• /
• 2021

Purpose: This study investigated the correlation between physical function and forward head posture in spastic diplegia. Methods: The subjects of this study were 10 spastic diplegia patients. We took pictures of the subjects' craniovertebral angle with a digital camera to determine the degree of forward head posture and then analyzed them using the NIH image J program. The physical function test used the TCMS, the BBT, and a spirometer. The data in this study were measured using SPSS version 23.0, and the statistical significance level α was 0.05. A Pearson correlation coefficient analysis was performed to identify the correlation between the degree of the subject's head forward position and physical function. Results: When we performed the BBT and spirometer tests, the subjects' forward head postures were not correlated (p < 0.05). However, with the TCMS, there was a strong correlation between the forward position of the head and balance, with balance decreasing as the head position increased (p < 0.05). Conclusion: Spastic diplegia patients with severe forward head posture showed problems with static balance, dynamic balance, and equilibrium reaction when sitting. Intervention on the right posture and preventive activities will be needed to improve the health of spastic diplegia patients and prevent future problems with physical function.