• Journal of Internet Computing and Services
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• v.10 no.5
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• pp.165-181
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• 2009

This paper presents an effective representation scheme for the shape analysis of the hippocampal structure and a stereoscopic-haptic environment to enhance sense of realism. The parametric model and the 3D skeleton represent various types of hippocampal shapes and they are stored in the Octree data structure. So they can be used for the interactive shape analysis. And the 3D skeleton-based pose normalization allows us to align a position and an orientation of the 3D hippocampal models constructed from multimodal medical imaging data. We also have trained Support Vector Machine (SVM) for classifying between the normal controls and epileptic patients. Results suggest that the presented representation scheme provides various level of shape representation and the SVM can be a useful classifier in analyzing the shape differences between two groups. A stereoscopic-haptic virtual environment combining an auto-stereoscopic display with a force-feedback (or haptic) device takes an advantage of 3D applications for medicine because it improves space and depth perception.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.2
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• pp.105-110
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• 1990

In this paper, a compliance robot control algorithm using a PID adaptive controller is proposed. The compliance robot is suitable for the tasks in contact with environment, such as assembly operation or surface processing. A hybrid robot control method can control force and position simultaneously and two independant feedback closed loops are formed in this method. Because the compliance robot is operated in contact with environment, it is very difficult to obtain linear model of dynamics for this robot. In order to overcome this difficulty, a PID adaptive controller independant of robot dynamics is applied to the compliance robot. The proposed control algorithm for the compliance robot was analyzed and conformed by simulating the surface processing task by a two-joint robot.

• Physical Therapy Rehabilitation Science
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• v.5 no.3
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• pp.138-142
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• 2016

Objective: The purpose of this study was to investigate how light touch with a finger affects balance ability when a posture is maintained in the condition of visual information blockage and to provide a fundamental material for developing balance ability in the process of rehabilitation treatment. Design: Cross-sectional study. Methods: The study subjects were 17 healthy men and women in their twenties and thirties who were studying at S University in Seoul. The system was comprised of an equilateral triangular force platform. Subjects were asked to step on the foot position of the force platform (Good Balance, Finland) barefooted for 30 seconds, with eyes closed, hands hanging down loosely, and feet comfortably apart. It was connected to a laptop by using Bluetooth technology. An experiment was conducted in the following three circumstances: 1) no-touch trial, 2) light touch to the back (T7 area), and 3) light touch to the middle finger of the left hand. Each subject was given a 10-minute break between consecutive measurements. The experimental circumstances were performed randomly. Anteroposterior sway (APSV), mediolateral sway velocity (MLSV), and velocity moment (VM) were measured. Results: The APSVs (mm/s) were $9.32{\pm}3.37$ and $5.45{\pm}2.98$; the MLSVs (mm/s), $6.39{\pm}3.35$ and $3.31{\pm}2.48$; and VM ($mm^2/s$), $17.13{\pm}11.75$ and $6.76{\pm}8.31$ in the first and second experimental circumstances, respectively. APSV, MLSV, and VM values were significantly improved with the 1) no-touch trial and 2) light touch to the back trail conditions compared with the 3) light touch to the middle finger of the left hand condition (p<0.05). Conclusions: This study revealed that the balance ability for maintaining a body posture was influenced more by light touch to the back (T7) than by light touch with the sensitive fingertip and body sway diminished after visual information was blocked.

• Journal of the HCI Society of Korea
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• v.1 no.1
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• pp.37-44
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• 2006

Specular reflections provide the visual feedback that describes the material type of an object, its local shape, and lighting environment. In photorealistic rendering, there have been a number of research available to render specular reflections effectively based on a local reflection model. In traditional cel animations and cartoons, specular reflections plays important role in representing artistic intentions for an object and its related environment reflections, so the shapes of highlights are quite stylistic. In this paper, we present a method to render and control stylized specular reflections using projective textures based on principal curvature analysis. Specifying a texture as a pattern of a highlight and projecting the texture on the specular region of a given 3D model, we can obtain a stylized representation of specular reflections. For a given polygonal model, a view point, and a light source, we first find the maximum specular intensity point, and then locate the texture projector along the line parallel to the normal vector and passing through the point. The orientation of the projector is determined by the principal directions at the point. Finally, the size of the projection frustum is determined by the principal curvatures corresponding to the principal directions. The proposed method can control the position, orientation, and size of the specular reflection efficiently by translating the projector along the principal directions, rotating the projector about the normal vector, and scaling the principal curvatures, respectively. The method is be applicable to real-time applications such as cartoon style 3D games. We implement the method by Microsoft DirectX 9.0c SDK and programmable vertex/pixel shaders on Nvidia GeForce FX 7800 graphics subsystems. According to our experimental results, we can render and control the stylized specular reflections for a 3D model of several ten thousands of triangles in real-time.

• The Journal of the Convergence on Culture Technology
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• v.8 no.2
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• pp.367-372
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• 2022

With the recent advent of the New Normal era, realistic technologies and non-contact technologies are receiving social attention. However, the hair styling field focuses on the direction of the hair itself, individual movements, and modeling, focusing on hair simulation. In order to create an improved practice environment and demand of the times, this study proposed a non-contact hair styling VR system. In the theoretical review, we studied the existing cases of hair cut research. Existing haircut-related research tend to be mainly focused on force-based feedback. Research on the interactive haircut work in the virtual environment as addressed in this paper has not been done yet. VR controllers capable of finger tracking the movements necessary for beauty enable selection, cutting, and rotation of beauty tools, and built a non-contact collaboration environment. As a result, we conducted two experiments for interactive hair cutting in VR. First, it is a haircut operation for synchronization using finger tracking and holding hook animation. We made position correction for accurate motion. Second, it is a real-time interactive cutting operation in a multi-user virtual collaboration environment. This made it possible for instructors and learners to communicate with each other through VR HMD built-in microphones and Photon Voice in non-contact situations.