• Journal of Broadcast Engineering
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• v.17 no.2
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• pp.223-236
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• 2012

We develop a video processing method that allows the more advanced human perception oriented video coding. The proposed method necessarily reflects all influences by the rate-distortion based optimization and the human visual perception that is affected by the visual saliency, the limited space-time resolution and the regional moving history. For reflecting the human perceptual effects, we devise an online moving pattern classifier using the Hedge algorithm. Then, we embed the existing visual saliency into the proposed moving patterns so as to establish a human visual perception model. In order to realize the proposed human visual perception model, we extend the conventional foveation filtering method. Compared to the conventional foveation filter only smoothing less stimulus video signals, the developed foveation filter can locally smooth and enhance signals according to the human visual perception without causing any artifacts. Due to signal enhancement, the developed foveation filter more efficiently transfers the bandwidth saved at smoothed signals to the enhanced signals. Performance evaluation verifies that the proposed video processing method satisfies the overall video quality, while improving the perceptual quality by 12%~44%.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2003.06a
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• pp.201-204
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• 2003

본 논문은 GPS 기술을 이용하여 지상 이동체의 위치 정보를 취득하고, 취득된 위치 정보를 이용하여 지상 이동체에 공공 정보와 상업 정보를 멀티미디어 데이터로 편집하여 실시간으로 제공하는 시스템을 제안하고 설계하였다. 설계한 시스템의 효용성과 신뢰성을 검증하기 위하여 PC와 Visual BASIC, 포토샵을 이용하여 시뮬레이션하였고, CYSTEL INC의 위성 수신기 모듈과 산업보드를 이용하여 제작하였다.

• Journal of the Ergonomics Society of Korea
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• v.31 no.6
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• pp.785-791
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• 2012

Objective: The aim of this study was to investigate the correlation between 3D visual fatigue and physiological measures by canonical correlation analysis enabling to categorical correlation. Background: Few studies have been conducted to investigate the physiological mechanism underlying the visual fatigue caused by processing 3D information which may make the cognitive mechanism overloaded. However, even the previous studies lack validation in terms of the correlation between physiological variables and the visual fatigue. Method: 9 Female and 6 male subjects with a mean age of $22.53{\pm}2.55$ voluntarily participated in this experiment. All participants were asked to report how they felt about their health sate at after viewing 3D. In addition, Low & Hybrid measurement test(Event Related Potential, Steady-state Visual Evoked Potential) and for evaluating cognitive fatigue before and after viewing 3D were performed. The physiological signal were measured with subjective fatigue evaluation before and after in watching the 3D content. For this study suggesting categorical correlation, all measures were categorized into three sets such as included Visual Fatigue set(response time, subjective evaluation), Autonomic Nervous System set(PPG frequency, PPG amplitude, HF/LF ratio), Central Nervous System set(ERP amplitude P4, O1, O2, ERP latency P4, O1, O2, SSVEP S/N ratio P4, O1, O2). Then the correlation of three variables sets, canonical correlation analysis was conducted. Results: The results showed a significant correlation between visual fatigue and physiological measures. However, different variables of visual fatigue were highly correlated to respective HF/LF ratio and to ERP latency(O2). Conclusion: Response time was highly correlated to ERP latency(O2) while the subjective evaluation was to HF/LF ratio. Application: This study may provide the most significant variables for the quantitative evaluation of visual fatigue using HF/LF ratio and ERP latency based human performance and subjective fatigue.

• Journal of the Institute of Convergence Signal Processing
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• v.19 no.3
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• pp.133-138
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• 2018

VR technology is a technology that allows a user to experience virtual reality close to reality by wearing an HMD (Head Mounted Display) device. Recently, as the interest in VR technology increases due to the 4th industrial revolution, various HMD devices are spreading. As a result, VR technology is being rapidly applied to various fields, but many of them still experience VR nausea. VR nausea is caused mainly by visual factors, unlike motion nausea, such as car nausea, sea nausea, and air nausea. Such occurrence of VR nausea may be caused by the characteristics of visual information of VR video contents, the hardware characteristics of HMD devices blocking the external visual field, or the physical specificity of individuals, and it is difficult to distinguish the causes. In this paper, we aim to analyze the characteristics of Visually Induced Motion Nausea images focusing on VR video content, which is the cause of VR nausea, in order to search for minimization of Cyber sickness occurrence.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.276-283
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• 2000

This paper presents the configuration of simulator for the functional test of TCMS on developing. This simulator is composed of three cabinets. There is equipped the TCMS system which have the same configuration of 1 train(SMG Line 7＆8) on the two cabinets. And there are equipped VME PC, VME CPU Board and I/F modules on the rest cabinet. This simulator has tow parts, which are user I/F part and Real-time signal processing part. We programed user I/F part with Visual C++ to support GUI function, and signal processing part with RTOS to support Real-Time signal processing. This simulator can produce all the signal and data for the TCMS functional testing.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.423-426
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• 2003

Adaptive algorithm used in Acoustic Echo Canceller (AEC) needs fast convergence algorithm when reference signal is colored speech signal. Set-Membership Affine Projection (SMAP) algorithm is derived from the constraint, which is the minimum value adaptive filter coefficient error. In this paper, we test the characteristic about noise of the SMAP algorithm and proposed modified version of SMAP algorithm fur using at AEC. As the projection order increase, the convergence characteristic of the SMAP algorithm is improved where no noise space. But if the noise uncorrelated with input signal exists, the AEC shows bad performance. In this paper, we propose normalized version of adaptive constants using estimated error signal for robust to noise and show the good performance through AEC simulation.

• Journal of the Korean Society of Safety
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• v.27 no.2
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• pp.117-126
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• 2012

Understanding driver's characteristic of visual activity is important process because driver depends on a visual signal more than 90% for getting outside information needed to drive, thus a series of driving, including perception, judgement, and activity, is completed. This study analyzes quantified driver's sight range in curved section where recognition of various information is critical due to biggest speed change among sections. Simulation is utilized for this study because of safety problem on field experiment and difficulties in using equipment. Building 6 roads that have different in curve radius by virtual driving map, experiment is carried out recruiting 30 people. Through analytical researches, it shows that drivers keep an eye on direction of driving, and driver's visual range is narrowed on left curve than right curve, and the more curve radius become small, the more drivers see in narrow angle.

• Phonetics and Speech Sciences
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• v.4 no.3
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• pp.25-30
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• 2012

This study investigated whether native Korean listeners could use visual cues for the identification of the English consonants /b/ and /v/. Both auditory and audiovisual tokens of word minimal pairs in which the target phonemes were located in word-initial or word-medial position were used. Participants were instructed to decide which consonant they heard in $2{\times}2$ conditions: cue (audio-only, audiovisual) and location (word-initial, word-medial). Mean identification scores were significantly higher for audiovisual than audio-only condition and for word-initial than word-medial condition. Also, according to signal detection theory, sensitivity, d', and response bias, c were calculated based on both hit rates and false alarm rates. The measures showed that the higher identification rate in the audiovisual condition was related with an increase in sensitivity. There were no significant differences in response bias measures across conditions. This result suggests that native Korean speakers can use visual cues while identifying confusing non-native phonemic contrasts. Visual cues can enhance non-native speech perception.

• Journal of Information Technology Services
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• v.15 no.4
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• pp.73-83
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• 2016

Pedestrian safety was recently highlighted with a yellow carpet, a yellow-colored pavement material prepared for children waiting for signals for pedestrian crossing, without validation of its efficiency in practice. It was a promising device likely to assist highway safety by stimulating pedestrian to step on the yellow-colored area; it was generally called nudge effects. This paper delivers a study conducted to check the effectiveness of yellow carpet in three different aspects in vehicle driver's perspective by applying the newly introduced information technology (IT) service: Visual Attention Software (VAS). It was assumed that VAS developed by 3M in the United States should be able explain the Korean drivers' visual reaction behaviors since technology embedded in VAS was developed based on and proved by other various international countries and continents in the world. A set of pictures was taken at thirteen different field sites in seven school zone areas in the Seoul metropolitan area before and after the installation of a yellow carpet, respectively. Sets of those pictures were analyzed with VAS, and the results were compared based on the selective safety measures: the likely focusing on standing pedestrians (waiting for a pedestrian's green signal time) affected by its background (yellow-colored pavement) contrasting him or her. The test results from a set of before-and-after comparison analyses showed that the placement of yellow carpet would (1) increase 71% of driver's visual attention on pedestrian crossing areas and (2) change the sequential order of visual attention on that area 2.4 steps ahead. The findings would enhance deployment of such promising efficiency and thus increase children safety in pedestrian crossing. The result was promising to highlight the way to support the changes in conservative traffic safety engineering field by applying the advanced IT services, while much robust research was recommended to overcome the limitation of simplification of this study.

• Physical Therapy Korea
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• v.31 no.1
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• pp.29-39
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• 2024

Background: Landing from a step or stairs is a basic motor skill but high incidence of lateral ankle sprain has been reported during landing with inverted foot. Objects: This study aimed to investigate the effect of landing height and visual feedback on the kinematics of landing and supporting lower limbs before and after the touch down and the ground reaction force(GRF)s. Methods: Eighteen healthy females were voluntarily participated in landing from the lower (20 cm) and the higher (40 cm) steps with and without visual feedback. To minimize the time to plan the movement, the landing side was randomly announced as a starting signal. Effects of the step height, the visual feedback, or the interaction on the landing duration, the kinematic variables and the GRFs at each landing event point were analyzed. Results: With eyes blindfolded, the knee flexion and ankle dorsiflexion on landing side significantly decreased before and after the touch down. However, there was no significant effect of landing height on the anticipatory kinematics on the landing side. After the touch down, the landings from the higher step increased the knee flexion and ankle dorsiflexion on both landing and supporting sides. From the higher steps, the vertical GRF, anterior GRF, and lateral GRF increased. No interaction between step height and visual feedback was significant. Conclusion: Step height and visual feedback affected the landing limb kinematics independently. Visual feedback affected on the landing side while step height altered the supporting side prior to the touch down. After the touch down, the step height had greater influence on the lower limb kinematics and the GRFs than the visual feedback. Findings of this study can contribute to understanding of the injury mechanisms and preventing the lateral ankle sprain.