• Korean Journal of Cognitive Science
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• v.34 no.3
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• pp.181-196
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• 2023

Size, velocity, and time equivalence are mechanisms that allow us to perceive objects in three-dimensional space consistently, despite errors on the two-dimensional retinal image. These mechanisms work on common cues, suggesting that the perception of motion distance, motion speed, and motion time may share common processing. This can lead to the hypothesis that, despite the spatial nature of visual stimuli distorting temporal perception, the perception of motion speed and the perception of motion duration will tend to oppose each other, as observed for objects moving in the environment. To test this hypothesis, the present study measured perceived speed using Müller-Lyer illusion stimulus to determine the relationship between the time-perception consequences of motion stimuli observed in previous studies and the speed perception measured in the present study. Experiment 1 manipulated the perceived motion trajectory while controlling for the retinal motion trajectory, and Experiment 2 manipulated the retinal motion trajectory while controlling for the perceived motion trajectory. The result is that the speed of the inward stimulus, which is perceived to be shorter, is estimated to be higher than that of the outward stimulus, which is perceived to be longer than the actual distance traveled. Taken together with previous time perception findings, namely that time perception is expanded for outward stimuli and contracted for inward stimuli, this suggests that when the perceived trajectory of a stimulus manipulated by the Müller-Lyer illusion is controlled for, perceived speed decreases with increasing duration and increases with decreasing duration when the perceived distance of the stimulus is constant. This relationship suggests that the relationship between time and speed perceived by spatial cues corresponds to the properties of objects moving in the environment, i.e, an increase in time decreases speed and a decrease in time increases speed when distance remains the same.

• Journal of the Korean Geophysical Society
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• v.3 no.3
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• pp.153-160
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• 2000

Crustal velocities around the Korea peninsula are estimated and investigated from eight IGS permanent stations in eastern Asia area. GPS data for the period of May 1995 to December 1991 were analyzed to estimate daily coordinates of each site relative to TAEJ site. The velocity vector of each site is estimated from linear regression analysis with time series of coordinates. As the result, horizontal velocity components for four stations(Tsukuba, Usuda,Taiwan and Shanghai) using thirty-two months data were estimated with the standard error less than 1 mm/year. Our GPS velocity of six sites on the interiors of the Eurasia plate are similar within 1 cm/year with small differences respectively. On the other hand, the velocities of Tsukuba and Usuda showed the great differences from the other six sites. This can be explained by the fact that these two sites are enforced by the surrounding four plates, such as the Pacific, Eurasia, North America and Philipine plate. This study showed that the distance between Korea and Japan is shortened with the rate of 3 cm per year.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1997.11a
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• pp.183-188
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• 1997

안구의 운동은 시각 환경에서의 진행중인 정보처리와 관련된 지각적, 인지적 과정을 밀접히 반영하는 중요한 지표로서, 특히 공간 지각과의 상관은 비교적 명확히 확립되어 있다. 본 연구는 공간지각에 관여하는 안구운동의 특성을 파악하여, 공간지각을 반영하는 안구운동 지표를 개발한다는 목표 아래, 피험자가 느끼는 공간의 확장과 축소의 특성을 이중도약과제(double-step paraeigm)를 사용하여 관찰한 것이다. 이중도약과제는 도약(saccadic)안구운동의 오차를 유발시키는 실험기법으로, 두개의 시각자극을 하나씩 연속적으로 보여주되, 두번째 자극은 안구운동이 일어나는 도중에 제시하는 것으로서, 인위적으로 왜곡된 공간에 대한 피험자의 공간적응을 관찰하는데 사용되었다. 이 과제는 다시 자극의 이차도약 방향에 따라 축소감 조건과 확장감 조건으로 나뉘었고, 머리운동의 역할을 판별하기 위해 머리를 고정한 조건과 머리를 자유롭게한 조건으로 분류되었다. 그 결과 머리가 고정된 상태에서는 축소감 조건에 대한 적응이 확장감 조건에서보다 더 빨리 일어나고, 그 적응후의 시선이동의 변화량에서도 축소감 조건이 더 크게 나타났다. 또한 머리를 자유롭게 할 공간 지각의 정확성이 증가하며, 축소감과 확장감 경험속도의 차이가 약 49.2%까지 해소되었으나, 여전히 축소감의 경험이 더 잘 일어났다.

• The Journal of Korean Academy of Sensory Integration
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• v.9 no.1
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• pp.21-31
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• 2011

Objective : This study investigated the relationships of handwriting legibility and perceptual-motor skills, and handwriting speed and perceptual-motor skills. And identified the predictors that most affect the handwriting of preschool children. Methods : Twenty-three typically developing preschool aged children (mean age: 68.61 months, SD=2.04) were selected through the Korean-Denver Developmental Screening Test-2(K-DDST-2). The children were tested with regard to handwriting legibility, visual perception, visual-motor integration and fine-motor coordination. Results : First, a significant relationship was not found among handwriting legibility, visual perception, visualmotor integration and fine-motor coordination. Second, a significant relationship was found among handwriting speed, visual perception and fine-motor coordination. Third, stepwise multiple regression analyses showed that general visual perception were significant predictors for handwriting speed. Conclusion : Occupational therapists should evaluate children's visual perception levels utilizing a standardized test, and focus on general visual perception in order to improve handwriting skill(speed). Also, occupational therapists are expected to play an important role in the management and treatment of children's handwriting skills.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.119-122
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• 2009

본 연구는 뇌졸중으로 인한 편마비 환자 20명을 대상으로 총 8주간 시지각 운동 과제를 적용하여 자세 균형, 보행 양상에 미치는 효과를 검증하고자 시행하였다. 실험군(n=10)과 대조군(n=10) 모두 보존적인 물리치료를 실시하였고 실험군에는 시지각 운동 과제 프로그램을 더하여 실시하였다. 본 연구의 결과는 실험군의 되먹임 측정을 통한 자세 균형 검사에서 편평한 지면 위에서 눈을 뜨고 감은 상태의 안정성 지수는 유의한 감소를 보였으며, pillow 위에서 눈을 뜨고 감은 상태의 안정성 지수도 유의하게 감소하였다. 체중분포지수는 편평한 지면에서 눈을 뜨고, 감은 상태와 pillow 위에서 눈을 뜨고 감은 상태 모두에서 유의하게 감소하였다. 실험군에서 10m 보행 속도는 대조군과 달리 유의하게 증가하였다. 본 연구에서의 시지각적 운동과제 프로그램은 편마비 환자의 신체기능과 관련된 자세균형 및 보행을 증진시키는 효과가 있었고 이에 보다 효과적인 운동방법으로 제시할 수 있다.

• Journal of the Korean earth science society
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• v.32 no.7
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• pp.719-731
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• 2011

Based on the ICE-3G and ICE-5G ice models, we predicted the velocities of crustal uplift caused by Glacial Isostatic Adjustment (GIA) at 39 tide gauge sites operated by Korea Hydrographic and Oceanographic Administration (KHOA). We also divided the Korean peninsula in the ranges of $32-38.5^{\circ}N$ and $124-132^{\circ}E$ in $0.5^{\circ}{\times}0.5^{\circ}$ grids, and computed the GIA velocities at each grid point. We found that the average uplift rates due to GIA in South Korea were 0.33 and 1.21 mm/yr for ICE-3G and ICE-5G, respectively. Because the GIA rates were relatively high at ~1 mm/yr when the updated ice model ICE-5G was used, we concluded that the GIA effect cannot be neglected when we compute the absolute sea level (ASL) rates around the Korean peninsula. In this study, we corrected the ICE-5G GIA velocities from the relative sea level rates provided by KHOA and we computed the ASL rates at 13 tide gauge stations. As a result, we found that the average ASL velocity around the Korean peninsula was 5.04 mm/yr. However, the ASL rates near Jeju island were abnormally higher than the other areas and the average was 8.84 mm/yr.

• Journal of the Korean earth science society
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• v.43 no.6
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• pp.661-679
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• 2022

Plate tectonics, with the continental drift theory and later strongly supported by the sea-floor spreading theory with evidence of paleo-geomagnetic fields, ocean floor sediments, successfully explained the slow but continuous movements of rigid lithospheres in geological time. Initially, plate motions were described as relative movements between adjacent plates, mainly based on paleo-geomagnetic reversal data. The advent of space geodetic techniques in the 1980s enabled direct measurements of plate velocities and assessment of deformations within certain regions. In this review, early relative plate motion models are briefly summarized, the no-net-rotation frame theory and corresponding models are explained, and the characteristics of the most recent models that incorporate intraplate deformation are described. Additionally, the plate motion section of the International Terrestrial Reference Frame is introduced, and a few recent case studies of local plate motion are briefly described; for example, in South America, Europe, Antarctica, and Turkey. Finally, studies of plate motion in northeastern Asia focusing on the Korean Peninsula are introduced.

• Journal of Life Science
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• v.26 no.12
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• pp.1466-1469
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• 2016

A group of traditional folk medicines obtained from the fruits of Rutaceae plants, such as Ponciri Fructus Immaturus (PFI) from Poncirus trifoliata Raf., Aurantii Fructus Immaturus (AFI) and Aurantii Pericarpium (AP) from Citrus aurantium L., and Aurantii Nobilis Pericarpium (ANP) from Citrus unshiu Marc., has been widely used for improving poor gastrointestinal function in East Asia, including in China and Korea. In the present study, the effects of Rutaceae-fruit-derived folk medicines on gastrointestinal motor function were investigated and compared by measuring in vivo gastric emptying and intestinal transit in mice. Among the aqueous and ethanolic extracts of some Rutaceae-fruit-derived folk medicines, an ethanolic extract of AP (AP-E) significantly accelerated intestinal transit in a dose-dependent manner without affecting gastric emptying. Furthermore, the intestinal transit rate of AP-E was the highest among all extracts examined in this study, including aqueous extracts of PFI, AFI, and ANP, of which the activities of accelerating intestinal transit have been already reported.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2002.05a
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• pp.241-250
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• 2002

본 연구의 목적은 최근 운전자 행동에 대한 연구 방법으로 매우 중요하게 대두되고 있는 운전 시뮬레이션 방법을 이용하여 운전자들이 보이는 기본적인 운전 수행 능력 및 이러한 운전 수행 능력과 관련이 가장 깊은 것으로 기존의 연구들이 밝혀왔던 기본적인 지각적/인지적/운동적 수행 능력을 측정하여 운전자 수행을 평가하는 것을 목적으로 한다. 특히 운전자의 운전 수행 및 운전과 관련된 기본적인 정신/운동 수행 능력은 정보 처리적 관점에서 측정되고 분석되었으며, 이를 통해 운전자들이 보이는 기본적인 정보처리 능력의 패턴에 대한 전반적 이해를 시도하였다. 본 연구에서는 기본적인 운전 수행 능력을 평가하는데 사용되는 차량의 속도 유지와 차선 유지에 대한 측정치와 더불어 운전과 관련한 인간 수행 중에서 단순 반응 능력, 선택 반응 능력, 속도 추정 능력, 청각적 주의나 시각적 주의의 분산 능력 등이 운전 시뮬레이션을 통하여 운전 중에 실시간으로 측정되었다. 본 연구에서 수집된 자료는 운전자들의 실제 운전 수행 및 이와 관련된 정보 처리 활동에 대한 표준화된 준거를 제시하는데 기초적 자료로 사용될 수 있으리라 생각된다.

• The Journal of Korean Academy of Sensory Integration
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• v.21 no.3
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• pp.39-53
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• 2023

Objective : The purpose was the effect of sensory integration therapy combined with an eye tracker on the sensory processing and visual perception of children with developmental disabilities. Methods : It was a single-subject study with a multiple baseline design between subjects, and the intervention applied sensory integration therapy combined with an eye tracker. Visual-motor speed and saccadic eye movements were assessed at each session of baseline and intervention periods. As pre- and post-evaluation, sensory profile, Korean-Developmental Test of Visual Perception and Trail Making Test were conducted. The results of each session evaluation and pre- and post-evaluation researched the effectiveness of the intervention through visual analysis and trend line analysis. Results : As a result of the evaluation for each session, the slope of the trend line for all children in visual-motor speed and saccadic eye movement increased sharply during the intervention compared to the baseline. As a result of the pre- and post-evaluation, the sensory processing of movement, body position, and visual changed from more than that of peers to a level similar to that of peers. In visual perception, all children's ability of Visual Closure increased. As a result of Trail Making Test conducted to confirm the improvement of children's visual tracking and visual-motor abilities, all children showed a decrease in performance time after the test compared to before. Conclusion : It was confirmed that sensory integration therapy combined with an eye tracker for developmental disabilities has effect on sensory processing and visual perception. It is expected to play an important role clinically as it can stimulate children's interest and motivation in line with recent technological improvements and the spread of smart devices.