• Journal of the Korean Society for Precision Engineering
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• v.15 no.9
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• pp.93-100
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• 1998

This study presents the new method which can transfer the expert's skill to deburring robot through neural network. The expert's skill is expressed as association mapping between the characteristics of the burr and human expert's action. Under the fundamental idea that the state of the deburring process can be extracted via the visual sense of the human, we employ vision system for the perception and identification of the changing burr. From the demonstration of human experts, force data are measured. Finally the characteristics of the burr and corresponding force are associated by the neural network which is trained through many demonstrations. The proposed method is verified in the deburring process of welding burr.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.1
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• pp.1-5
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• 1998

This study presents intelligent deburring system which can transfer the exper's skill to deburring robot through neural network. The expert's skill is expressed as associate mapping between the characteristics of the burr and human expert's action. Under the fundamental idea that the state of the deburring process can be extracted via the visual sense of the human, we employ vision system for the perception and identification of the changing burr. From the demonstration of human experts, force data are measured and fitted impedance model. Finally the characteristics of the burr and coressponding force are associated by the neural network which is trained through many demonstrations. The proposed method is verified in the deburring process of welding burr.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.1
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• pp.41-51
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• 2007

Differential equations and their solutions were formulated to describe the deflection of the tapered, nonuniform thickness and width's temple, clamped at one end while the perpendicular force is acting on the other end which is freely suspended. The model was derived based on laws of continuity at every point inside the elastic medium that the deflection, tangent slope, bending moment, shearing force must be continuous within the medium. The model is found to be in good agreement with measurements on the beta titanium temple with the correlation 0.992 and p=0.999(Chi test). Therefore it is possible to predict the effect of various temple parameters such as elastic modulus, thickness, width on the deflection of the temples being considered.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1503-1506
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• 2002

In this paper, a modified particle system is proposed for volcanic eruption with lava, ashes and smoke. In the proposed method each eruptive material consists of particles. The movement of particles is determined by the external force and interaction (attraction: repulsion and viscosity) only in neighbor region. Since the method can be executed in combination with the geographic information, the proposed method may also be useful for disaster prevention.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.637-642
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• 1998

This study was performed to develop effective management system of concrete structures in Nuclear Power Plants. This D/B system includes three kinds of data : 1)visual inspection data(cracking, spalling, etc.) 2) durability data carbonation, chloride attack, etc. 3) in-service inspection data(prestressing force. material properties, etc. ) By using the life management D/B System, the field engineers can easily acquire the information about the various inspection data. repair and accidental histories of structures. This system, will contribute to the efficient life management of concrete structures.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.1036-1043
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• 2022

This paper discusses about the development of a visual sensor that can be installed in an automatic mooring device to detect the berthing condition of a vessel. Despite controlling the ship's speed and confirming its location to prevent accidents while berthing a vessel, ship collision occurs at the pier every year, causing great economic and environmental damage. Therefore, it is important to develop a visual system that can quickly obtain the information on the speed and location of the vessel to ensure safety of the berthing vessel. In this study, a visual sensor was developed to observe a ship through an image while berthing, and to properly check the ship's status according to the surrounding environment. To obtain the adequacy of the visual sensor to be developed, the sensor characteristics were analyzed in terms of information provided from the existing sensors, that is, detection range, real-timeness, accuracy, and precision. Based on these analysis data, we developed a 3D visual module that can acquire information on objects in real time by conducting conceptual designs of LiDAR (Light Detection And Ranging) type 3D visual system, driving mechanism, and position and force controller for motion tilting system. Finally, performance evaluation of the control system and scan speed test were executed, and the effectiveness of the developed system was confirmed through experiments.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1472-1479
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• 2018

The purpose of this study was to investigate the ability to maintain dynamic posturography(EquiTest) in gymnastic, freestyle skier, and figure skater. A total of 32 subjects(22 athletic woman and 10 collegiate woman) were participated in this study. Computerized dynamic posturography(EquiTest) was adopted to test sensory organization and motor control. EquiTest facilitated the quantification of the role of somatosensory, visual and vestibular systems in the maintenance of postural balance and was also pertinent to measure the reaction time to the stimulus to change center of gravity on force platform. As a result were as follow. There was not difference among with exercise group. But there was a significantly difference with between groups. It was suggested that the acrobatic and physical activity developed the function of visual system and the role of the combination of visual and vestibular system in maintaining postural balance to surrounding stimulus, and presented shorter reaction time in automatic postural response.

• The Journal of Korean Physical Therapy
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• v.34 no.5
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• pp.212-217
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• 2022

Purpose: This study sought to investigate the effects of visual cue deprivation balance training by applying head control feedback to the balance function and the fall index in older people. Methods: The study was conducted on 26 older people at the S Hospital in Gyeongsansi. The patients were randomly divided into the experimental groupI (EGI, n=9), the experimental groupII (EGII, n=9), and the control group (CG, n=8). The three groups were trained for 30 minutes three times a week for four weeks. To assess the patients' static balance function, their limits of stability (LOS) was measured using the BioRescue system, (RM Ingenierie, France), composed of a pressure platform that can measure force in diverse ways, a computer, and a monitor. The dynamic balance function was measured using the Berg Balance Scale (BBS). Also, the fall index was measured to evaluate the risk of falling. A paired t-test was performed to compare pre- and post-training performance within the groups. One-way ANOVA was performed for comparing the three groups. A post hoc least significant difference (LSD) test was also performed. Results: The results of the LOS showed a significant difference after training in the EGI and EGII groups (p<0.05). As a result of the difference between the three groups, there was a significant difference after training (p<0.05). The results of the BBS showed a significant difference after training in the EGI group (p<0.05). As a result of the difference between the three groups, there was a significant difference after training (p<0.05). Conclusion: Visual cue deprivation balance training applying head control feedback is effective in improving the dynamic balance function in older people. It is also necessary to constantly maintain the head orientation by feedback and to properly control the head movement.

• Korean Journal of Applied Biomechanics
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• v.15 no.1
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• pp.45-61
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• 2005

Stance is defined as any state in which the total mass of the body is supported by the feet. In order to maintain stance, the sum of gravito-inertial forces acting on the body must be registered by equal and opposite forces at the region of contact between the organism and the support surface. Balance is controlled by applying forces to the surface of support so as to maintain the body's center of mass vertically above the feet. for a muIti-segment organism, there can be a variety of ways in which balance can be controlled, since movements of different body segments can have similar effects on the control of balance. In general, the organism tends to have a body configuration that is aligned with gravito-inertial force when there are no external forces acting on it. If any segments of the body are not aligned with gravito-inertial force vector, a torque on that segment would tend to move the body's center of mass. The maintenance of postural stability is accomplished in humans by a complex neural control system. This requires organizing integrating and acting upon visual, vestibular, and somatosensory input, providing orientation information to the postural control system. The information necessary to control and coordinate movement is provided by the visual sense of eye position with respect to the surrounding surface layout, the vestibular sense of head orientation in the gravito-inertial space, and the somatic sense of body segment position relative to one another and to the support surface. In this study, perception and action capability was examined from various points of view. The underlying assumption of the study was that the change of postural configuration could be effected by organism, environment and task goal.

• Journal of Biomedical Engineering Research
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• v.28 no.1
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• pp.117-126
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• 2007

In this paper, we propose an early rehabilitation training system for the improvement of postural balance with multi-modality on a tilting bed. The integration of the visual, somatosensory and vestibular functions is significant to for maintaining the postural control of the human body. However, conventional rehabilitation systems do not provide multi-modality to trainees. We analyzed the characterization of postural control at different tilt angles of an early rehabilitation training system, which consists of a tilting bed, a visual feedback, a computer interface, a computer, and a force plate. The software that we developed for the system consists of the training programs and the analysis programs. To evaluate the characterization of postural control, we conducted the first evaluation before the beginning of the training. In the following four weeks, 12 healthy young and 5 healthy elderly subjects were trained to improve postural control using the training programs with the tilting bed. After four weeks of training, we conducted the second evaluation. The analysis programs assess (center of pressure) COP moving time, COP maintaining time, and mean absolute deviation of the trace before and after training at different tilt angles on the bed. After 4 weeks, the COP moving time was reduced, the COP maintaining time was lengthened, and the mean absolute deviation of the trace was lowered through the repeated use of vertical, horizontal, dynamic circle movement training programs. These results show that this system improves postural balance and could be applied to clinical use as an effective training system.