• Korean Journal of Cognitive Science
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• v.16 no.1
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• pp.17-27
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• 2005

After prolonged viewing of a moving pattern, a stationary pattern can appear to move in the opposite direction, a phenomenon known as motion aftereffect (MAE). Unlike the classical explanation MAE was not confined to an adapted region; instead it can spread to an adjacent region, which was not adapted previously. In order to examine the relative locus of the mechanism responsible for MAE spreading, a rotating harmonic spiral pattern was presented as an adapting stimulus within an annulus window, and then the duration of MAE was measured in both the adapted annulus region and the non-adapted inner region. Two different kinds of test patterns were used: the same and mirror images of the original adapting pattern. An interesting characteristic of a harmonic spiral is that the orientation of a contour at a given location is different from thar of its mirror image by 90 degrees, and consequently the adapting effect of local motion detector is not expected to occur in the mirror image. The results showed that MAE duration in an adapted region was longer in the same image condition than in its mirror image condition, while MAE duration in an non-adapted region was not found to be different between those two different image conditions. These results suggest that MAE spreading might be produced by the adaptation of global motion detectors, not by local motion detectors.

• Korean Journal of Cognitive Science
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• v.10 no.3
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• pp.29-37
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• 1999

Murakami and Cavanagh (1998a,b, 1999) reported a jitter aftereffect in a static random noise after a period of adaptation to a patch of dynamic random noise. To a account for this phenomenon. they proposed the retinal slip caused by a small eye movements in the unadapted area, which is usually compensated by the visual system to stabilize images but is unsuppressed due to the adaptation. We tested this hypothesis with new experimental method and stimuli that were supposed to nullify or reduce the effect. However. the aftereffect was still observed even under these stimuls conditions More importantly, the perceived aftereffect was rather different from Murakami and Cavanagh's. After adaptation to a counterphase flickering cosine grating, the adjacent unadapted region seems to move away from the observer during the test period instead of jittering in the frontoparallel plane. We proposed a possible explanation for this new phenomenon noting the severe contrast reduction of the adapted region during flickering period. The aftereffect might be due to the flicker-inducing contrast reduction during adaptation that produces different depth planes for the adapted and unadapted region and its restoration during the test period.

• Korean Journal of Cognitive Science
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• v.21 no.1
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• pp.1-24
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• 2010

The stationary image appears to move after we view a moving stimulus for a long time. The motion aftereffect(MAE) can spread to an adjacent region if there is no contrast discontinuity between two regions. In this study, it is investigated whether a phenomenon of MAE spreading to an adjacent non adapting area is affected by the depth discontinuity defined by binocular disparity. In the first experiment a disparity defined slanted pattern was presented in an unadapted region, and in the second experiment, a disparity defined pattern with a different depth was presented on the fronto-parallel plane. Although MAE duration in the condition with slanted pattern was not different from that in the non-slanted pattern condition, MAE durations in the pattern presented on pronto-parallel plane was vividly reduced, but not completely disappeared. These results suggest that a phenomenon of MAE spreading might be affected by depth discontinuity, and could be occurred after binocular information converges.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.10
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• pp.995-1002
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• 2016

The aim of this study was investigated the effect of orofacial exercise program using smart phone on swallowing function and tongue strength in acute stroke patients with dysphagia. This study participated in sixteen acute stroke patients with dysphagia. All subjects allocated that randomized each eight patients in experimental and control groups. Subjects of both group received to conventional dysphagia therapy during 30 min/day, 5 times per week, for 4 weeks. Experimental group performed additionally that orofacial exercise program using smart phone, supervised under caregivers, during 30 min/day. The outcome measures were the IOPI(: Iowa Oral Performance Instrument), VR(: Vellecula Residue), PSR(: Pyriform Sinuses Residue), MIP(: Maximum Isometric Pressures). In results of study. Both group showed significant improvements after intervention in all assessments(p<.05). In comparison of change score between two groups, experimental group showed significant improvements than control group in PSR and MIP(p<.05). Orofacial exercise program using smart phone suggested that expected to positive effects the reduction of residue in pharynx and improvements of tongue strength in acute stroke patients with dysphagia.

• The Journal of Korean society of community based occupational therapy
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• v.5 no.1
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• pp.23-34
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• 2015

Objective : The purpose of this study is to investigate the effect of self swallowing exercise program with neuromuscular electrical stimulation(NMES) on swallowing function. Methods : Subjects who were diagnosed in dysphagia were randomly divided into the control group or experimental group. Both group were received NMES during 60 minutes with traditional swallowing therapy during 30 minutes. Additionally the experimental group was received self swallowing exercise during 30 minutes. We invested subject's characteristics through medical chart. We used VDS(Videofluoroscopic Dysphagia Scale) and PAS(Penetration Aspiration Scale) for assessing the swallowing function. Results : There were not significantly different in both group's pre swallowing function. The control group was significantly improved on pyriform sinus residue, aspiration, and VDS total score(p<.05). The experimental group was significantly improved on vallecular residue, pyriform sinus residue, and VDS total score(p<.05). Both group's difference of pre and post swallowing function were not significantly different. Conclusion : Self swallowing exercise and traditional swallowing therapy with NMES and traditional swallowing therapy with NMES are positive effect on swallowing function. The self swallowing exercise is not effective factor.

• Korean Journal of Applied Biomechanics
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• v.24 no.2
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• pp.95-101
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• 2014

The purpose of this study was to investigate the training and detraining effects of a 8-week water exercise on lower extremities coordination during obstacle gait in the female elderly. Eight elderly participants (age: $76.58{\pm}4.97$ yrs, height: $148.88{\pm}7.19$ cm, body mass: $56.62{\pm}6.82$ kg, and leg length: $82.36{\pm}2.98$ cm), who stayed at the Seoul K welfare center, were recruited for this study. All participants had no history of orthopedic abnormality within the past 1 year and completed the aquatic exercise program which lasted for 8 weeks. To identify the training and detraining effect of 8 weeks of water exercise, a 3-D motion analysis with 7 infrared cameras and one force plate sampling frequency set at 100 Hz and 1,000 Hz, respectively, was performed. A two-way ANOVA was performed to find training and detraining effects among diferent obstacle heights. In this study significant level was set at .05. Significant training effects of LTS (lead foot thigh and shank) coordination in all obstacle height were found (p<.05). It is also found that the training effect of LTS remained 37%, 58%, and 25% in obstacle height of 30%, 40%, and 50%, respectively. Lead foot showed the greater detraining effect of coordination compared with trail foot, and SF (shank and foot) coordination revealed better detraining effects of coordination compare with TS (thigh and shank) in both feet. Based on the findings, a 8 week water exercise give an positive effects to the elderly in terms of segment cooperation which potentially helps reducing their accident falls. The magnitude of detraining may also help the elderly to find the retraining moment.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.5
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• pp.593-598
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• 2005

The standard Kalman filter has been used to estimate the states of the target, but in the presence of a maneuver, its error is occurred and performance may be seriously degraded. To solve this problem, this paper presents a new intelligent tracking algorithm using the fuzzy Kalman filter. In this algorithm, the unknown acceleration is regarded as an additive process noise by using the fuzzy logic based on genetic algorithm(GA) method. And then, the modified filter is corrected by the new update equation method which is a fuzzy system using the relation between the filter residual and its variation. To shows the feasibility of the suggested method with only one filter, the computer simulations system are provided, this method is compared with multiple model method.