• The Journal of Korean Physical Therapy
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• v.32 no.3
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• pp.152-156
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• 2020

Purpose: The subjective visual vertical (SVV) test is used to evaluate the otolith function in the inner ear. This study compared the different balance ability according to the results of the SVV in healthy adults. Methods: This study recruited 30 normal healthy subjects who did not have neurological and musculoskeletal disorders. The subjects were divided into experimental and control groups based on the results of SVV: experimental group, >2°; control group, <2°. The static balance ability was evaluated using the Fourier Index, which could evaluate the balance capacity objectively and quantitatively. Results: The mean angle of the SVV in the experimental and control groups was 4.44° and 0.59°, respectively. In the result of the Fourier series, the F1 frequency band in the experimental group showed a significantly higher value under one condition compared to the control group (p<0.05). In the F2-4 and F5-6 frequency bands, the experimental group showed a significant increase in the Fourier series value under the four conditions compared to the control group (p<0.05). In the F7-8 frequency band, significantly higher values of the Fourier series were observed in the experimental group under the three different conditions (p<0.05). Conclusion: These results showed increased trunk sway while maintaining static balance in the experimental group who showed a larger SVV angle compared to the control group. The SVV can be applied to evaluate the vestibular system and balance ability in normal adults.

• The Korean Journal of Applied Statistics
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• v.30 no.3
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• pp.487-501
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• 2017

A machine vision system (MVS) is a computer system that utilizes one or more image-capturing devices to provide image data for analysis and interpretation. Recently there have been a number of industrial- and medical-device applications where control charts have been proposed for use with image data. The use of image-based control charting is somewhat different from traditional control charting applications, and these differences can be attributed to several factors, such as the type of data monitored and how the control charts are applied. In this paper, we investigate the adjustment effect of image size and region of interest (ROI) size, when we use control charts to monitor grayscale image data in industry.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.5
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• pp.933-940
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• 2022

In this paper, the algorithm was developed to recognize hand 3D position through 2D image sensor and implemented a system to remotely control the 6 d.o.f. robot arm by using it. The system consists of a camera that acquires hand position in 2D, a computer that controls robot arm that performs movement by hand position recognition. The image sensor recognizes the specific color of the glove putting on operator's hand and outputs the recognized range and position by including the color area of the glove as a shape of rectangle. We recognize the velocity vector of end effector and control the robot arm by the output data of the position and size of the detected rectangle. Through the several experiments using developed 6 axis robot, it was confirmed that the 6 d.o.f. robot arm remote control was successfully performed.

• Physical Therapy Korea
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• v.12 no.4
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• pp.12-19
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• 2005

The purpose of this study was to investigate the possibility of virtual moving surround (VMS) on static balance in the patients with balance dysfunction. Eighty three subjects who were admitted or treated as an outpatient, or a family member, at the department of rehabilitation unit of university hospital were recruited to participate. Subjects were three groups based on their overall medical status: healthy, diabetic neuropathy and stroke. Each group was tested for static balance with a forceplate during static standing with VMS. The virtual movement was simulated with a head mounted display. The parameters for static balance were total sway path. In this study, the parameters of postural control for patients with diabetic neuropathy and stroke subjects were significantly increased in conditions elicited with the VMS. In the healthy elderly participants, the total sway path was not significantly different under virtual movement conditions. Therefore, VMS could be used in the evaluation and treatment of the patients with balance dysfunction.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.3
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• pp.219-226
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• 2013

A distortion correction technique is presented to enhance the 3D scanning performance of a micro-size camera-projector system. Recently, several types of micro-size digital projectors and cameras are available. However, there have been few effort to develop a micro-size 3D scanning system. We develop a micro-sized 3D scanning system which is based on the structured light technique. Three images of phase-shifted sinusoidal patterns are projected, captured, and analyzed by the system to reconstruct 3D shapes of very small objects. To overcome inherent optical imperfection of the micro 3D sensor, we correct the vignetting and blooming effects which cause distortions in the phase image. Error analysis and 3D scanning results on small real objects are presented to show the performance of the developed 3D scanning system.

• International Journal of Control, Automation, and Systems
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• v.5 no.6
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• pp.663-673
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• 2007

This paper presents a new moving obstacle detection method using an optical flow in mobile robot with an omnidirectional camera. Because an omnidirectional camera consists of a nonlinear mirror and CCD camera, the optical flow pattern in omnidirectional image is different from the pattern in perspective camera. The geometry characteristic of an omnidirectional camera has influence on the optical flow in omnidirectional image. When a mobile robot with an omnidirectional camera moves, the optical flow is not only theoretically calculated in omnidirectional image, but also investigated in omnidirectional and panoramic images. In this paper, the panoramic image is generalized from an omnidirectional image using the geometry of an omnidirectional camera. In particular, Focus of expansion (FOE) and focus of contraction (FOC) vectors are defined from the estimated optical flow in omnidirectional and panoramic images. FOE and FOC vectors are used as reference vectors for the relative evaluation of optical flow. The moving obstacle is turned out through the relative evaluation of optical flows. The proposed algorithm is tested in four motions of a mobile robot including straight forward, left turn, right turn and rotation. The effectiveness of the proposed method is shown by the experimental results.

• Research in Community and Public Health Nursing
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• v.28 no.3
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• pp.260-270
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• 2017

Purpose: The purpose of this study was to examine the effects of the motivational interviewing (MI) dementia preventive intervention on dementia preventive behaviors, depression and cognitive function among elderly over 75 years of age in nursing homes. Methods: A nonequivalent control group pretest-posttest design was used. A total of 57 participants were divided into three groups; 18 in the MI dementia preventive intervention (Group A), 20 in the dementia preventive program (Group B) and 19 in the control group. Dementia preventive behaviors, depression, and cognitive function were assessed at pre, post, and 1 month after the intervention. Data were analyzed using descriptive statistics, t-test, ANOVA and repeated measure ANOVA. Results: The results reported that there were significant differences in dementia preventive behaviors and depression among Group A, B, and C. Also, there were significant differences in dementia preventive behaviors and cognitive function during time periods. There was a significant interaction between groups and times in relation to depression. Results suggested that the effects of MI dementia preventive program was persistent after 1 month following the intervention. Conclusion: Further research needs to develop dementia preventive programs considering physical and mental traits of the elderly in late years staying at nursing homes.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.12
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• pp.1189-1195
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• 2014

This paper addresses a Moving Target Indication (MTI) algorithm which can be used for small Unmanned Aerial Vehicles (UAVs) equipped with image sensors. MTI is a system (or an algorithm) which detects moving objects. The principle of the MTI algorithm is to analyze the difference between successive image data. It is difficult to detect moving objects in the images recorded from dynamic cameras attached to moving platforms such as UAVs flying at low altitudes over a variety of terrain, since the acquired images have two motion components: 'camera motion' and 'object motion'. Therefore, the motion of independent objects can be obtained after the camera motion is compensated thoroughly via proper manipulations. In this study, the camera motion effects are removed by using wiener filter-based image registration, one of the non-parametric methods. In addition, an image pyramid structure is adopted to reduce the computational complexity for UAVs. We demonstrate the effectiveness of our method with experimental results on outdoor video sequences.

• Journal of Institute of Control, Robotics and Systems
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• v.2 no.1
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• pp.26-34
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• 1996

One of the challenging tasks in visual inspection using CCD camera is to identify surface defects in an image with complex textured backgeound. In microscopic view, the surface of real objects shows regular or random textured patterns. In this paper, we present a visual inspection algorithm to extract abnormal surface defects in an image with textured background. The algorithm uses the space and frequency information at the same time by introducing the Dominant Frequency Map(DFM) which can describe the frequency characteristics of every small local region of an input image. We demonstrate the feasibility and effectiveness of the method through a series of real experiments for a 14" TV CRT mold. The method successfully identifies a variety of infinitesimal defects, whose size is larger than $50\mu\textrm{m}$, of the mold. The experimental results show that the DFM based method is less sensitive to the environmental changes, such as illumination and defocusing, than conventional vision techniques.ques.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.11
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• pp.1486-1495
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• 2018

This paper investigates the autonomous ground vehicle (AGV) localization filter design problem under GNSS-denied environments. It is assumed that the given landmarks do not have unique features due to the lack of a prior knowledge on them. For such case, the AGV may have difficulties in distinguishing the position measurement of the detected landmark from those of other landmarks with the same feature, hence the conventional localization filters are not applicable. To resolve this technical issue, the localization filter design problem is formulated as a special form of the data association determining whether the detected feature is actually originated from which landmark. The measurement hypotheses generated by landmarks with the same feature are evaluated by the nearest neighbor data association scheme to reduce the computational burden. The position measurement corresponding to the landmark with the most probable hypothesis is used for localization filter. Through the experiments in real-driving condition, it is shown that the proposed method provides satisfactory localization performance in spite of using non-unique landmarks.