• Educational Technology International
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• 제11권2호
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• pp.1-24
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• 2010

The study aimed to investigate the differential effects of visual and verbal scaffoldings on web-based problem solving performance. A quasi-experiment with 143 high school students in South Korea was administered. Each student's visualization tendency score was obtained at the beginning of the study. Based on the visualization tendency scores, students were divided into two groups; low and high level visualization tendency groups. Then each group was split in half and randomly assigned to one of the two lessons - one with visual scaffolding and the other with verbal scaffolding. The contents of the two lessons were the same. All students' performance was measured through an essay assignment for a problem solving at the end of the lesson. The result showed that the visual scaffolding group outperformed the verbal scaffolding group (F=22.54, p<.01), regardless of each student's visualization tendency level. The effect size was 0.81, indicating high practical significance. There was no statistically significant interaction effect between scaffolding modalities and students' visualization tendency levels. These findings imply that visual scaffolding is an effective strategy to promote students' problem solving performance.

• 한국안광학회지
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• 제18권3호
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• pp.291-295
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• 2013

Purpose: The purpose of this study was to investigate the effect of under and over refractive correction on visual acuity performance and the variation of the visual performance measurement using two different visual acuity charts. Methods: Ten young adults, aged between 19 and 25 years old, were recruited. Inclusion criteria: no history of ocular injury or pathology with a best-corrected visual acuity of 6/6 on dominant eye. The over and under refractive corrections were induced using minus and plus spherical ophthalmic lenses in 0.50 D steps up to 3.00 D; as well as using three axis orientations of cylindrical ophthalmic lenses ($45^{\circ}$, $90^{\circ}$ and $180^{\circ}$) in 0.50 D steps. The variation of visual acuity performance measurements was investigated using Bailey-Lovie LogMAR chart and Landolt C chart. Results: The visual acuity changes with lenses were significantly different between two charts [F = 49.15, p < 0.05 with plus spherical ophthalmic lenses and F = 174.38, p < 0.05 with minus spherical ophthalmic lenses]. The visual acuity changes with three different cylindrical axis showed no significant difference between Bailey-Lovie LogMAR chart [F = 2.35, p > 0.05] and Landolt C chart [F = 3.12, p = 0.05]. Conclusions: The over and under refractive correction affected the visual acuity performance differently. The Landolt C chart and Bailey-Lovie LogMAR chart demonstrated variation in measurements.

• 대한인간공학회지
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• 제21권1호
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• pp.95-112
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• 2002

Two experiments were carried out to compare the suitability in visual tasks between cathode-ray tube (CRT) and thin film transistor-liquid crystal display (TFT-LCD). In the first experiment, the subjects were requested to detect pre-assigned target words or icons among distracters presented under time-invariant (static) image mode. The subjects' visual performance and fatigue were assessed while carrying out search tasks with dim and bright ambient light conditions. Significant interaction effects were found among displays, task types, and ambient light conditions. Due to visual fatigue, the subjects' accommodative power decreased in the end of task and the degradation was more significant for the CRT users and under bright ambient light. IN the second experiment, the subjects performed information processing task with time-varying road signs at a driving simulator to assess interaction effects between display types and changing speed of dynamic image. The perception time using TFT-TCD was shorter under slow image change while that of CRT was shorter rapid image change. Findings from this study suggest that, to improve visual task performance, users should carefully select their visual display type depending on the task to be performed.

• 재활치료과학
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• 제9권1호
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• pp.45-55
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• 2020

목적 : 본 연구의 목적은 국내에 거주하는 뇌졸중 환자를 대상으로 시지각 능력이 운전수행에 미치는 영향을 알아보고 운전수행능력 향상을 위한 시지각 훈련의 중요성을 제시하고자 하였다. 연구 방법 : 2014년 10월부터 11월까지 서울시 소재 병원에 입원중인 뇌졸중 환자 19명을 대상으로 MVPT(Motor-free Visual Perception Test), TMT A&B(Trail Making Test A & B), UFOV(Useful Field Of View test)를 사용하여 시지각능력 검사를 실시하였으며, 가상현실 운전시뮬레이터를 이용하여 운전수행능력을 검사하였다. 결과 : 뇌졸중 환자의 운전수행은 다양한 시지각 능력 평가도구와 관련성이 있었으며, UFOV 하위검사 2, TMT B, MVPT에서 가장 높은 상관관계가 나타났다. 또한, 시지각 능력 평가결과는 운전시뮬레이터 평가결과(합격/불합격)를 민감도 100.0%, 특이도 80.0%, 정확도 89.5%로 판별할 수 있었다. 결론 : 뇌졸중 환자의 운전수행에 있어 시지각 능력이 운전수행능력과 매우 높은 관련성이 있는 것으로 나타났다. 본 연구를 통해 운전 재활 분야에서 시지각 능력과 관련된 운전재활 및 운전수행능력 평가를 시행하는데 유용하게 사용될 것으로 기대한다.

• 대한인간공학회지
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• 제22권3호
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• pp.27-44
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• 2003

An experiment was carried out to compare the suitability in visual tasks between flat and conventional (convex) cathode-ray tube (CRT) displays. The subjects performed visual search tasks during 2-h for detecting target words among distracters presented on the screen. The subjects' visual performance was evaluated with average time and number of errors made to complete the tasks. Visual fatigue after the search tasks was also evaluated in terms of degradations in accommodative power and subjective ratings. Difference was not found in task time between the two displays, but flat CRT showed a lower number of errors than conventional CRT. The difference in number of errors was statistically significant at 0=0.05. Although there was no difference between the displays in degradations of accommodative power, results from the subjective ratings showed that flat CRT yields less fatigue than conventional CRT. The results partially support the hypothesis that panel convexity of CRT displays has a significant effect on the performance and fatigue during visual tasks and thus flat CRT is the better display than conventional one.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1550-1553
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• 2009

We studied the human visual performance with PDP and LCD to clarify the relationships between viewer preference and chromatic adaption. In this paper, optical performance of the display is measured mechanically based on standard. The human visual performance about the display color image quality trough optical process is represented numerically based on CIECAM02. By comparing these results with the result of the questionnaire, performance of the display can be evaluated in detail.

• 대한인간공학회지
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• 제31권6호
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• pp.725-731
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• 2012

Objective: The aim of this study is to investigate visual feedback effects and human performance in the foot mouse control. Background: Generally, computer mouse tasks are controlled by visual feedback. In order to understand the characteristics of a foot mouse control, it is important to investigate the patterns of visual feedback involved in foot-mouse control tasks. Human performance of foot mouse control is also an important factor to understand the foot mouse control. Method: Three types of mouse control were determined to investigate visual feedback effects and human performance in the foot mouse control. Visual feedback effects in the foot mouse control were compared with those of a typical hand mouse. The cursor movement speed and mental workload were measured in the three types of tasks and two types of mouses. Results: Mouse control tasks with an element of homing-in to the target were more quickly performed by the hand mouse than the foot mouse. Mental workload was also higher in the foot mouse than the hand mouse. However, in the steering movement, human performance of the foot mouse control was not lower than that of the hand mouse control. Visual feedback in the foot mouse control was less required than in the hand mouse control. Conclusion: The foot mouse was not efficient in the most mouse control tasks, compared to the hand mouse. However, the foot mouse was efficient in the steering movement, moving a cursor within a path with lateral constraints. Application: The results of this study might help to develop the foot mouse.

• International journal of advanced smart convergence
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• 제12권4호
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• pp.361-369
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• 2023

Achieving realistic visual quality while maintaining optimal real-time rendering performance is a major challenge in evolving computer graphics and interactive 3D applications. Normal mapping, as a core technology in 3D, has matured through continuous optimization and iteration. Hybrid normal mapping as a new mapping model has also made significant progress and has been applied in the 3D asset production pipeline. This study comprehensively explores the hybrid normal techniques, analyzing Linear Blending, Overlay Blending, Whiteout Blending, UDN Blending, and Reoriented Normal Mapping, and focuses on how the various hybrid normal techniques can be used to achieve rendering performance and visual fidelity. performance and visual fidelity. Under the consideration of computational efficiency, visual coherence, and adaptability in different 3D production scenes, we design comparative experiments to explore the optimal solutions of the hybrid normal techniques by analyzing and researching the code, the performance of different hybrid normal mapping in the engine, and analyzing and comparing the data. The purpose of the research and summary of the hybrid normal technology is to find out the most suitable choice for the mainstream workflow based on the objective reality. Provide an understanding of the hybrid normal mapping technique, so that practitioners can choose how to apply different hybrid normal techniques to the corresponding projects. The purpose of our research and summary of mixed normal technology is to find the most suitable choice for mainstream workflows based on objective reality. We summarized the hybrid normal mapping technology and experimentally obtained the advantages and disadvantages of different technologies, so that practitioners can choose to apply different hybrid normal mapping technologies to corresponding projects in a reasonable manner.

• 대한인간공학회지
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• 제16권2호
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• pp.29-38
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• 1997

The research on the factors which effect on legibility is mainly utilized as the basic data of selecting the standard guideline of VDT screen. But the research on Korean is scarcer than that of English. Furthermore, it is unreasonable to apply the results of the foreign language to Korean, beause of the difference between the typography of English and that of Korean. Therefore, more systematic and ergonomic research of the Korean typography on VDT screen is needed. In this paper, an experimental study on search speed and error rate is designed and performed according to different Korean letter size and font on search task with VDT. The experimental screen based on popular Ming and Gothic style is made up of total 12 artificial screens, each 6 different font size. As the criteria of the performance, searching speed(s.s.) and error rate (e) are selected, and CFF value is measured to evaluate user's visual fatigue. The results of experiment in font show that the Korean Gothic style is superior to the Korean Ming style in user's visual performance. The letter size that gives user the optimal performance ranges from the visual angle 39.8' to 55.5' in Ming style, from the visual angle 39.8' to 52.6' in Gothic systle. In visual fatigue experiment, the better performance of letter size is, the less tired user feels. And the smaller letter size is, the more tired user feels. There is no relationship between font and user's visual fatigue.

• 대한전기학회논문지:시스템및제어부문D
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• 제49권1호
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• pp.41-47
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• 2000

A better tracking performance can be achieved, if visual sensors such as CCD cameras are used in controling a robot manipulator, than when only relative sensors such as encoders are used. However, for precise visual servoing of a robot manipulator, an expensive vision system which has fast sampling rate must be used. Moreover, even if a fast vision system is implemented for visual servoing, one cannot get a reliable performance without use of robust and stable inner joint servo-loop. In this paper, we propose a dynamic control scheme for robot manipulators with eye-in-hand camera configuration, where a dynamic learning controller is designed to improve the tracking performance of robotic system. The proposed control scheme is implemented for tasks of tracking moving objects and shown to be robust to parameter uncertainty, disturbances, low sampling rate, etc.