• Physical Therapy Korea
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• v.8 no.3
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• pp.27-34
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• 2001

Physical therapists have been using biofeedback training to induce improvements in various circumstances. The purpose of this study was to compare the effects of visual and tactile feedback using electrical stimulation on quadriceps strength. Nineteen women without known impairment of the neuromusculoskeletal system volunteered for this study. Subjects were randomly allocated into three groups: visual feedback, tactile feedback, and control group. The torque of isometric knee extension force was measured. Subjects were asked to exert the maximal isometric contraction force of quadriceps over a 30 second period. The resting period of 10 minutes was given after the maximal isometric contraction to avoid the muscle fatigue. In between groups comparison, significant differences of the peak torque and the torque area were found on the performance of the maximal isometric contraction of quadriceps (p<.05). The values peak of torque and torque area were significantly higher during visual feedback than tactile feedback. The results of this study suggest that visual feedback is more powerful than tactile feedback (p<.01).

• Archives of design research
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• v.13 no.1
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• pp.111-120
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• 2000

Certain complex forces are existing at the other side of a canvas. These are visual arrangements and within the arrangement, even the simple combination of dots and lines create more than visual patterns. No matter what form that visual art has taken, it is performed in a certain space and it is constucted with various visual elements. For effective communication, visual elements must form a stable sturcture by extablishing organic relationship among each other. These requires an understanding of the human visual characteristics and psychonology, because human sight senses the same biological and psychological visual elements differently in its force and weight, according to the position within a given space. Although the structure which controls such force and weight exists within a peice of work, it is a internal plan of the work that actually controls the communication through a man\ulcorner psychological reactions towards the horizontal and virtical structures within it. Moreover it is a visual statement that effectively expresses a theme or a message. This thesis has studied visual structures through the analysis of art pieces regarding of these kind of a visual picture plane, characteristics of a picture plane formed by a structure of force existing on the other side of the picture and the theory of visual balance. In addition, the aim of this study is to help designers who deals with visual image works to understand the visual structures and psychological recognitions and to apply these picture plane compositions at their real work by recognizing the psychological power within the construction elements.

• Korean Journal of Applied Biomechanics
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• v.15 no.2
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• pp.103-111
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• 2005

The purpose of this study was to analysis golf swing in accordance with each club using ground reaction force data. The subject of this study was current professional golf players in Korea. Golf clubs used for this study were driver, iron4, iron7, and pitching. The ground reaction force for left and right foot was collected by one Kistler and one Bertec force platforms. Also collected visual data by NC high speed camera to check the phase which was composed of address, top of backswing, impact and finish. Sampling rate was 600Hz both ground reaction forces data and visual data. The conclusion are as follows. 1. An aspect of change for ground reaction force was that the weight between the left foot and right foot were contrary to each other in general as the phase. 2. Without regard to the type of golf club, the ratio of necessary ground reaction forces for each phase in accordance with address, top of backswing, impact, and finish was comparatively identical. 3. According to the type of golf club, the tendency of Fy was not varied. In terms of Driver, at the moment of impact, the weight of foot-both right and left-was moved to the movement direction of golf because of the rotation force from swing.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.8
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• pp.855-861
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• 2007

Haptic rendering is a process providing force feedback during interactions between a user and a virtual object. This paper presents a real-time haptic rendering technique for deformable objects based on visual information of intervention between a tool and a real object in a remote place. A user can feel the artificial reaction force through a haptic device in real-time when a slave system exerts manipulation tasks on a deformable object. The models of the deformable object and the manipulator are created from the captured image obtained with a CCD camera and the recognition of objects is achieved using image processing techniques. The force at a rate of 1 kHz for stable haptic interaction is deduced using extrapolation of forces at a low update rate. The rendering algorithm developed was tested and validated on a test platform consisting of a one-dimensional indentation device and an off-the shelf force feedback device. This software system can be used in a cellular manipulation system providing artificial force feedback to enhance a success rate of operations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.1
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• pp.371-384
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• 2019

Motion perception has been tremendously improved in neuroscience and computer vision. The baseline motion perception model is mediated by the dorsal visual pathway involving the cortex areas the primary visual cortex (V1) and the middle temporal (V5 or MT) visual area. However, few works have been done on the extension of neural models to improve the efficacy and robustness of motion perception of real sequences. To overcome shortcomings in situations, such as varying illumination and large displacement, an adaptive V1-MT motion perception (Ad-V1MTMP) algorithm enriched to deal with real sequences is proposed and analyzed. First, the total variation semi-norm model based on Gabor functions (TV-Gabor) for structure-texture decomposition is performed to manage the illumination and color changes. And then, we study the impact of image local context, which is processed in extra-striate visual areas II (V2), on spatial motion integration by MT neurons, and propose a V1-V2 method to extract the image contrast information at a given location. Furthermore, we take feedback inputs from V2 into account during the polling stage. To use the algorithm on natural scenes, finally, multi-scale approach has been used to handle the frequency range, and adaptive pyramidal decomposition and decomposed spatio-temporal filters have been used to diminish computational cost. Theoretical analysis and experimental results suggest the new Ad-V1MTMP algorithm which mimics human primary motion pathway has universal, effective and robust performance.

• Journal of the Korean Applied Science and Technology
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• v.39 no.5
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• pp.701-709
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• 2022

The purpose of this study was to compare the differences according to the visual selection and rotation order during sequential rotational jump for female dancers of a Korean ballet company by classifying them into take-off and landing sections. 10 subjects (age: 26.0±2.9 yrs, height: 163.4±3.3 cm, weight: 46.8±3.6 kg, ballet career: 12.3±5.9 yrs) participated in the study. Using a 3D motion analyzer and a force platform, the height of the body center and the ground reaction force during take-off and landing were measured. According to the visual condition (using both eyes, using left eye, using right eye) and rotation order (first rotation, second rotation), it was analyzed through repeated measurement two-way analysis. Height of the CM was higher in the first jump. In take-off, Fx was lateral force of left foot and medial force of right foot were strong in second rotation, and Fy was forward force was strong in first rotation of right foot. Fz was no significant. In landing, Fy showed backward force was strong when landing the second time from the left foot, and the backward force was strong when using the left sight from the right foot. Fz was strong on the second landing on the left foot and the first landing on the right foot.

• Journal of muscle and joint health
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• v.18 no.1
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• pp.16-27
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• 2011

Purpose: The purpose of this study was to investigate the effects of a visual feedbackbased balance training, using force platform biofeedback, on the postural balance of elderly faller. Methods: Fifty one community-dwelling older adults (aged 66-88 years) with a recent history of fall participated in the study. Participants were randomized to an experimental group (EG, n=25) and to a control group (CG, n=26). The EG participated in training sessions three times/week for 6 weeks. Visual feedbackbased balance training with the a computerized force platform with visual feedback screen was used in the experimental group. Static balance (center of gravity) and dynamic balance (Functional reach test, Timed "Up & Go" test, Berg balance scale) were assessed before and after end of training. Results: A significant improvement in static balance and dynamic balance were demonstrated within the EG (p<.05), but not in the CG. Conclusion: Visual feedback-based balance training may be an effective intervention to improve postural balance of elderly fallers.

• Cartoon and Animation Studies
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• s.15
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• pp.73-88
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• 2009

Light is a basic force that functions in all the formative arts. Light (brightness) is an important subject of study in that it contains the force to control emotion and has much influence upon the shaping of a visual image and a feeling. If an artist systematizes the characteristics of brightness and creates an image, he or she can acquire a useful tool of expression. Because light is a powerful medium of expression of a visual image, a study on the characteristics of brightness for the emotional expression of an image in the contextual relationship with narratives seemingly has a crucial meaning. Emotion is influenced by a visual image very much, and a visual image is inevitably influenced by light. The brightness by light is basically classified into bright, dim, and dark. And the three basic stages of brightness specialize an image according to the setting of scope of maximal and minimal luminosity, and the image is further differentiated by the size of bright portion or dark portion. Since emotion is such a phenomenon as immaterial and psychological, it is difficult to break down it. Furthermore, clarifying the principle of an image in which the shade of light is associated is impossible. However, the width of luminosity and the change of size can give quite a change to a visual image, and the visual image has further influence upon man's emotion too. Although the influence of brightness upon a visual image varies with extents, circumstances, and personal tastes and interests, even the same image clearly changes with the adjustment of brightness.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.7
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• pp.250-257
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• 1999

Driving simulators are used effectively for human factor study, vehicle system development and other purposes by enabling to reproduce actural driving conditions in a safe and tightly controlled enviornment. Interactive simulation requries appropriate sensory and stimulus cuing to the driver . Sensory and stimulus feedback can include visual , auditory, motion, and proprioceptive cues. A fixed-base driving simulator has been developed in this study for vehicle system developmnet and human factor study . The simulator consists of improved and synergistic subsystems (a real-time vehicle simulation system, a visual/audio system and a control force loading system) based on the motion -base simulator, KMU DS-Ⅰ developed for design and evaluation of a full-scale driving simulator and for driver-vehicle interaction.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.8
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• pp.585-591
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• 2003

A virtual force is generated and fed back to the operator to make the teleoperation more reliable, which reflects the relationship between a slave robot and an uncertain remote environment as a form of an impedance. In general, for the teleoperation, the teleoperated mobile robot takes pictures of the remote environment and sends the visual information back to the operator over the Internet. Because of the limitations of communication bandwidth and narrow view-angles of camera, it is not possible to watch certain regions, for examples, the shadow and curved areas. To overcome this problem, a virtual force is generated according to both the distance between the obstacle and the robot and the approaching velocity of the obstacle w.r.t the collision vector based on the ultrasonic sensor data. This virtual force is transferred back to the master (two degrees of freedom joystick) over the Internet to enable a human operator to estimate the position of obstacle at the remote site. By holding this master, in spite of limited visual information, the operator can feel the spatial sense against the remote environment. It is demonstrated by experiments that this collision vector based haptic reflection improves the performance of teleoperated mobile robot significantly.