• Journal of Advanced Navigation Technology
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• v.13 no.2
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• pp.257-261
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• 2009

This paper propose a new method using Gestalt theory to extract image contour. The proposed method use Gestalt theory based on proximity, similarity and continuation for grouping objects from image segmentation. It use downward feedback and perception to materialize one visual level in image from heterogeneity visual levels in image. The experimental result show that the proposed method achieves better performance than other methods.

• The Journal of the Korea Contents Association
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• v.13 no.10
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• pp.9-18
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• 2013

In this paper, we analyzed the effects of game-based visual feedback training on postural balance control in young adults and older adults. We provided postural balance training by 23 young adults and 14 older adults and for four weeks in fifth minute a day and three days a week using IBalance(Cybermedic Inc., Korea). We evaluated the ability of postural balance using balance SD(Biodex, medicalscience Inc., USA) for the validation of game contents based on visual feedback training program. The results showed that postural stability and limits of stability of young adults and older adults were improved significantly before and after the training(p<0.05). Thus, the games of postural balance encouraged anterior, posterior, medial, lateral and multidirectional weight shifting regarding postural balance. Our study indicates that postural balance training of visual feedback based game could be adapted for improving postural balance. Moreover, we could develope of game contents for individuals and various ages for effective application of this game-based visual feedback training.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6475-6482
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• 2015

The purpose of the study was two folded: to examine whether form-focused instruction (FFI) with corrective feedback (CF) is effective for the acquisition of the target linguistic forms and to find out the extent to which of the students' perceptions as well as their attitudes towards English instruction that they received. Tests and questionnaires were implemented to 122 Korean EFL students from eight classes enrolled in an English communication course. They were randomly assigned to three groups: the input-based group, who received typographical input enhancement materials, so-called the TIE group, the output-based group, who performed dictogloss tasks, so-called the DICT group, and the control group (CG). The data analysis was made on both tests and questionnaires by using SPSS 21.0 for Windows. The study found that different types of FFI with CF contributed to the improvement of students' grammatical knowledge and both the TIE and DICT task group students positively changed their perceptions and understanding as well as their attitudes towards the English instruction given, and students in all groups preferred pair work activities. In addition, most of the TIE and DICT students showed their interest and satisfaction with English class, whereas the CG group students did not. Based on the findings, this study suggested that well-planned and properly-chosen FFI in the form of pair work activities should be applied in classrooms with consideration of students' instructional preference in Korean EFL contextual settings.

• Journal of the Korea Computer Graphics Society
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• v.26 no.3
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• pp.9-19
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• 2020

With the recent development of various kinds of virtual reality devices, there has been an active research effort to increase the sense of reality by recognizing the physical behavior of users rather than by classical user input methods. Among such devices, the Leap Motion controller recognizes the user's hand gestures and can realistically trace the user's hand in a virtual reality environment. However, manipulating an object in virtual reality using a recognized user's hand often causes the hand to pass through the object, which should not occur in the real world. This study presents a way to build a visual feedback system for enhancing the user's sense of interaction between hands and objects in virtual reality. In virtual reality, the user's hands are examined precisely by using a ray tracing method to see if the virtual object collides with the user's hand, and when any collision occurs, visual feedback is given through the process of reconstructing the user's hand by moving the position of the end of the user's fingers that enter the object through sign distance field and reverse mechanics. This enables realistic interaction in virtual reality in real time.

• Journal of the Korea Computer Graphics Society
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• v.15 no.3
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• pp.1-9
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• 2009

Traditional computer simulation uses only traditional input and output devices. With the recent emergence of haptic techniques, which can give users kinetic and tactile feedback, the field of computer simulation is diversifying. In particular, as the virtual-reality-based surgical simulation has been recognized as an effective training tool in medical education, the practical virtual simulation of surgery becomes a stimulating new research area. The surgical simulation framework should represent the realistic properties of human organ for the high immersion of a user interaction with a virtual object. The framework should make proper both haptic and visual feedback for high immersed virtual environment. However, one model may not be suitable to simulate both haptic and visual feedback because the perceptive channels of two feedbacks are different from each other and the system requirements are also different. Therefore, we separated two models to simulate haptic and visual feedback independently but at the same time. We propose an adaptive mass-spring method as a multi-modal simulation technique to synchronize those two separated models and present a framework for a dual model of simulation that can realistically simulate the behavior of the soft, pliable human body, along with haptic feedback from the user's interaction.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10b
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• pp.119-121
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• 2000

최근 급속히 발전하고 있는 컴퓨터 하드웨어 기술로 이미지, 오디오, 비디오 등의 방대한 멀티미디어 데이터가 비 선별적으로 일반 사용자에게 제공되어지고 있다. 하지만 상이한 해석이 가능한 멀티미디어 데이터의 특성상 정확한 데이터의 전달을 위해 각각의 사용자의 취향을 고려할 수 있는 지능 컴퓨팅 기술 즉, 개인화 모델의 이용이 필수적이다. 개인화 모델의 구축을 위해서는 사용자의 피드백 정보를 필요로 하게 되는데, 현재까지의 연구는 결과에 대한 만족정도를 사용자가 일일이 조사해야 하는 부담 때문에 사용자에게는 일반적인 환경에서 사용자의 묵시적인 피드백 정보를 이용하는 기술 개발의 필요성이 강조되고 있다. 본 논문에서는 묵시적으로 사용자의 시각 정보 및 행위 정보를 이용하여 사용자의 부담을 줄이는 동시에 적응 및 학습 능력을 갖는 지능 사용자 인터페이스를 적용한 내용기반 이미지 검색 시스템을 구현하였다.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.4
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• pp.420-430
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• 2003

This paper presents an immersive multimodal Gumdo simulation game that allows a user to experience the whole body interaction with an intelligent cyber fencer. The proposed system consists of three modules: (i) a nondistracting multimodal interface with 3D vision and speech (ii) an intelligent cyber fencer and (iii) an immersive feedback by a big screen and sound. First, the multimodal Interface with 3D vision and speech allows a user to move around and to shout without distracting the user. Second, an intelligent cyber fencer provides the user with intelligent interactions by perception and reaction modules that are created by the analysis of real Gumdo game. Finally, an immersive audio-visual feedback by a big screen and sound effects helps a user experience an immersive interaction. The proposed system thus provides the user with an immersive Gumdo experience with the whole body movement. The suggested system can be applied to various applications such as education, exercise, art performance, etc.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.2 s.314
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• pp.37-46
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• 2007

In this paper, we propose technologies for enhancing the immersive realization of virtual objects in AR-based product design. Generally, multimodal senses such as visual/auditory/tactile feedback are well known as a method for enhancing the immersion in case of interaction with virtual objects. By adapting tangible objects we can provide touch sensation to users. A 3D model of the same scale overlays the whole area of the tangible object so the marker area is invisible. This contributes to enhancing immersion. Also, the hand occlusion problem when the virtual objects overlay the user's hands is partially solved, providing more immersive and natural images to users. Finally, multimodal feedback also creates better immersion. In our work, both vibrotactile feedback through page motors, pneumatic tactile feedback, and sound feedback are considered. In our scenario, a game-phone model is selected, by way of proposed augmented vibrotactile feedback, hands occlusion-reduced visual effects and sound feedback are provided to users. These proposed methodologies will contribute to a better immersive realization of the conventional AR system.

• Journal of the Korea Convergence Society
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• v.8 no.3
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• pp.63-70
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• 2017

The purpose of this study was to evaluate the effects of oral health education feedback using $Qraycam^{TM}$. The middle school students 118 were divided into intervention group (59) and control group (59) subjects evaluated the dental plaque score using $Qraycam^{TM}$ after oral health education at baseline. Then, the $Qraycam^{TM}$ images view only sent to students and parents of the intervention group by text message. After 4 weeks both intervention group and control group were evaluated dental plaque by $Qraycam^{TM}$ re-taking. Then, they filled out the questionnaire. Both ${\Delta}R$ value and SPS(Simple Plaque Score) were statistically significant reduced in groups performed feedback(p<0.001). The oral health behavior, toothbrushing of intervention group was significantly higher compared to the control group(p<0.001). Also the importance of oral health was significantly higher in the intervention group compared to the control group(p<0.001). The effect of dental plaque reducing, toothbrushing time and subjective oral health importance were higher in the intervention group who received feedback using $Qraycam^{TM}$ image. Therefore it was expected to be able to utilize $Qraycam^{TM}$ image as a visual feedback tool of oral health education.

• Proceedings of the KIEE Conference
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• 2008.10c
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• pp.248-249
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• 2008

본 논문에서는 원칩 마이크로컨트롤러를 사용한 파워 LED 구동제어 시스템의 설계 및 구현에 대해 중점적으로 기술한다. 파워 LED의 조광제어 및 특정 조도에서의 정전류 구동을 위해 전류피드백을 통한 디지털 PI 전류제어 및 PWM 구동방식을 행하였고, 시각적인 깜박거림 없는 충분한 주파수의 스위칭을 통해 부스트 컨버터를 연속도통모드로 동작시켰다. 본 논문에서 제시한 파워 LED 구동을 위한 디지털 제어시스템은 최근의 에너지 및 환경규제에 적합한 조명관련 응용분야에서 다양하게 적용될 것으로 판단된다.