• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.2
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• pp.477-483
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• 2004

This paper describes preliminary results we have obtained in developing a computer vision system based on active IR illumination for real time gaze tracking for interactive graphic display. Unlike most of the existing gaze tracking techniques, which often require assuming a static head to work well and require a cumbersome calibration process for each person our gaze tracker can perform robust and accurate gaze estimation without calibration and under rather significant head movement. This is made possible by a new gaze calibration procedure that identifies the mapping from pupil parameters to screen coordinates using the Generalized Regression Neural Networks(GRNN). With GRNN, the mapping does not have to be an analytical function and head movement is explicitly accounted for by the gaze mapping function. Futhermore, the mapping function can generalize to other individuals not used in the training. The effectiveness of our gaze tracker is demonstrated by preliminary experiments that involve gaze-contingent interactive graphic display.

• Journal of the Korean Society of Radiology
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• v.7 no.4
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• pp.271-275
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• 2013

Shoulder bone scan everyday life, sports activities at the side of the shoulder joint, or applying strong force in the lateral occurs. Mainly on upper arm abduction, temple, other rotational dislocation of the shoulder joint gahaejyeo as useful for observing the presence or absence of lesions is used. Shoulder PA oblique projection prevent distortion of the image due to the angle and the most useful diagnostic radiological investigate shooting angle. Shoulder blade body and the acromion and coracoid process Y-view is formed characters. $10^{\circ}$ angle between the shoulder blades and the acromion is the obstruction. $20^{\circ}{\sim}25^{\circ}$ to the Y-view of the humerus head looks superimposed, the position of the shoulder joint and seemed appropriate. $35^{\circ}$ of the humerus head superimposed on the Y-view, but above the humerus head and shoulder joints were distorted. When $45^{\circ}$ elevation observed on the side of the best has come Y-view also acromion and coracoid process is finished.

• Proceedings of the Korea Information Processing Society Conference
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• 2018.10a
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• pp.889-891
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• 2018

가상현실 (Virtual Reality, VR) 컨텐츠가 다양해지면서 사용자들의 관심도 높아지고 있다. 초기 VR 컨텐츠는 헤드 마운티드 디스플레이 (Head Mounted Display, HMD)와 컨트롤러만 사용한다. 사용자의 요구가 높아지면서 현실적인 컨텐츠 구현을 위해서 사용자의 신체 움직임으로 제어하는 풀 바디 트래킹(Full Body Tracking) 기술이 도입되고 있다. 머리에 착용하는 HMD와 양손으로 제어하는 두 개의 컨트롤러 뿐만 아니라 모션캡쳐장비, 트래커 장비를 사용자의 다양한 위치에 착용시켜, 세밀한 움직임 트래킹이 가능해졌다. 본 연구에서 서브 모션 기반의 움직임 추적 방법과 이를 기반한 서브모션 시스템을 제안한다. 서브모션 시스템은 VR 컨텐츠에 사용되는 사용하는 센서 위치를 VR캐릭터의 대응되는 위치에 출력하는 방식이 아닌, 사용자의 움직임에 따라 다양한 센서 위치 변화를 인식하고, 이를 기반으로 VR에서 사전에 지정된 모션을 인식 및 출력한다. 사용자의 움직임을 세분화하여 각각의 연속된 서브모션들로 인식하고, 각각의 서브 모션에서 연속적으로 인식 가능한 서브 모션을 분기를 통해 정의하고 인식함으로써 다양하고 자유도 높은 모션 처리가 가능하다. 선행 기술들의 문제점인 고정된 데미지 방식 및 부자연스러운 모션을 해결하고 사용자에게 실제와 같은 동작을 취하도록 유도하여 몰입감등을 부여할 수 있다. 서브 모션들을 자동적으로 생성하는 시스템을 통해 풀 바디 트래킹 VR 컨텐츠에 적용 가능한 엔진을 연구 및 개발하여 해당 산업의 발전에 이바지하고자 한다.

• The Journal of the Acoustical Society of Korea
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• v.36 no.2
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• pp.130-135
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• 2017

In this paper, we propose an interface for interactive sound experience in the virtual concert hall. The proposed interface consists of two systems, called 'virtual acoustic position' and 'virtual active listening'. To provide these systems, we applied an artificial reverberation algorithm, multi-channel source separation and head-related transfer function. The proposed interface was implemented by using Unity. The interface provides the virtual concert hall to user through Oculus Rift, one of the virtual reality headsets. Moreover, we used Leap Motion as a control device to allow a user experience the system with free-hand. And user can experience the sound of the system through headphones.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.1
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• pp.8-13
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• 2001

It has been well known that cross-talk canceller for 3D audio using loudspeakers depends on a listeners position called the sweet-spot. Therefore, new cross-talk canceller was proposed that increases robustness to perturbations such as head movement, reverberations, and different head shapes. It was made up 3 loudspeakers structure to be combined with symmetric and asymmetric speaker geometry. In this paper, we propose new cross-talk canceller using 2 loudspeakers having the same efficiency as existing cross-talk canceller using 3 loudspeakers. The results of the study is verified through the listening tests and also presented a cross-talk cancelling methods for improved 3-D audio production in details.

• The Journal of Korean Physical Therapy
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• v.25 no.4
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• pp.217-223
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• 2013

Purpose: This study was to investigate whether the two different head postures, natural and ideal head posture, affect head/shoulder posture and muscle activity. Methods: Thirty healthy subjects with the forward head and round shoulder posture were participated in this study. This study utilized a within-subjects design with subjects being positioned into two sitting positions: natural head posture (NHP) and ideal head posture (IHP). Forward head angle (FHA) and forward shoulder angle (FSA) of each subject were measured for assessing the head/shoulder posture and muscle activities of upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA) during the forward overhead reaching. Results: There were significant increases in both FHA and FSA after taking IHP, which showed greater angles than in taking NHP. In change of muscle activities, there were significant decreases in both LT and SA after taking IHP, which showed lower activities than in taking a NHP, whereas there was no significant change in UT. Conclusion: These findings demonstrate that postural alterations associated with forward head and rounded shoulder postures could alter scapular kinetics and muscle activity during the forward overhead reaching.

• Journal of Biomedical Engineering Research
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• v.15 no.4
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• pp.481-488
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• 1994

In this paper a study of neuro-pathway estimation based on visual and somatosensory evoked potential is given. The evoked potentials which are caused by visual and somatosensory stimulation are detected by an average method. The forward problem that is estimating a scalp potential from a given electrical source in the brain is solved by using a triple concentric spherical shell model of the head and a single current dipole model of the neuron activity. The inverse problem which calculates a source position is solved by a least square fit between the model predicted potential and a given evoked potential measurement. The similarities between estimated sensory neuro-pathways and physiological brain function regions are verified.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.2 no.3
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• pp.61-69
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• 2009

In this paper, to propose a new approach to real-time eye tracking. Existing methods of tracking the user's attention to the little I move my head was not going to get bad results for each of the users needed to perform the calibration process. Infrared eye tracking methods proposed lighting and Generalized Regression Neural Networks (GRNN) By using the calibration process, the movement of the head is large, even without the reliable and accurate eye tracking, mapping function was to enable each of the calibration process by the generalization can be omitted, did not participate in the study eye other users tracking was possible. Experimental results of facial movements that an average 90% of cases, other users on average 85% of the eye tracking results were shown.

• Journal of Korea Multimedia Society
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• v.10 no.4
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• pp.506-515
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• 2007

In this paper, we propose a Real-time Interactive Shadow Avatar(RISA) which can express facial emotions changing as response of user's gestures. The avatar's shape is a virtual Shadow constructed from the real-time sampled picture of user's shape. Several predefined facial animations overlap on the face area of the virtual Shadow, according to the types of hand gestures. We use the background subtraction method to separate the virtual Shadow, and a simplified region-based tracking method is adopted for tracking hand positions and detecting hand gestures. In order to express smooth change of emotions, we use a refined morphing method which uses many more frames in contrast with traditional dynamic emoticons. RISA can be directly applied to the area of interface media arts and we expect the detecting scheme of RISA would be utilized as an alternative media interface for DMB and camera phones which need simple input devices, in the near future.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.3
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• pp.25-32
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• 2016

The pile-cap connection part which transfers foundation loads through pile body is critical element regarding flexural and shear force because the change of area, stress, and stiffness occurs in the this region suddenly. The purpose of this study is to investigate the structural behavior of pile-cap connection dependent on fabrication methods using conventional PHC pile and composite PHC pile. A series of test under cyclic lateral load was performed and the connection behavior was discussed. From the test results, it was found that the initial rotational stiffness of pile-cap connection was affected by the length of pile-head inserted in footing and the location of longitudinal reinforcing bars. The types of pile and location of longitudinal reinforcing bars governed the behavior of pile-cap connection regarding load-carrying capacity, ductility, and energy dissipation.