• Title/Summary/Keyword: Visual response

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A Heuristic Approach for Simulation of time-course Visual Adaptation for High Dynamic Image Streams

  • Kelvin, Bwalya;Yang, Seung-Ji;Choi, Jong-Soo;Park, Soo-Jun;Ro, Yong-Man
    • Proceedings of the Korea Information Processing Society Conference
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    • 2007.05a
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    • pp.285-288
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    • 2007
  • There is substantial evidence from earlier researches that older adults have difficult seeing under low illumination and at night, even in the absence of ocular diseases. During human aging, there is a rampant decrease in rod/cone-meditated adaptation which is caused by delayed rhodopsin regeneration and pigment depletion. This calls for a need to develop appropriate visual gadgets to effectively aid the aging generation. Our research culminates its approach from Pattanaik's model by making extensions to temporal visual filtering, thereby simulating a reduction of visual response which comes with age. Our filtering model paves way and lays a foundation for future research to develop a more effective adaptation model that may be further used in developing visual content adaptation aids and guidelines in MPEG 21 environment. We demonstrate our visual model using a High Dynamic Range image and the experiment results are in conversant with the psychophysical data from previous vision researches.

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Reproduction of Arm Kinesthetic Sense in Virtual Environment Using Bilateral Control (양방향 제어를 이용한 가상환경에서의 팔운동감 제시)

  • 정웅철;민두기;송재복;김용일
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 1999.11a
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    • pp.97-100
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    • 1999
  • Human feels kinesthetic sense in response to the force acted on him. In order to represent kinesthetic sense, a force is analyzed as mechanical impedance (i.e., stiffness or damping) and implemented by active impedance control. In this research, a 3-dimensional arm motion generator is developed to present various mechanical impedance characteristics to an operator. An introduction of virtual reality provides not only a visual effect in virtual environment but also the change in force synchronized with the visual effect in real time.

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A Color Correction Method for High-Dynamic-Range Images Based on Human Visual Perception (인간 시각 인지에 기반을 둔 높은 동적폭을 갖는 영상 보정 방법)

  • Choi, Ho-Hyoung;Song, Jae-Wook;Jung, Na-Ra;Kang, Hyun-Soo
    • Journal of Korea Multimedia Society
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    • v.18 no.9
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    • pp.1027-1038
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    • 2015
  • For last several decades, the color correction methods have been proposed for HDR(high dynamic range) images. However, color distortion problems take place after correcting the colors such as halos, dominant color as well known. Accordingly, this article presents a novel approach in which the method consists of tone-mapping method and cone response function. In the proposed method, the tone mapping method is used to improve the contrast in the given HDR image based on chromatic and achromatic based on the CIEXYZ tristimulus value, expressed in c/m2. The cone response function is used to deal with mismatch between corrected image and displayed image as well as to estimate various human visual effects based on the CMCAT2000 color appearance model. The experimental results show that the proposed method yields better performance of color correction over the conventional method in subjective and quantitative quality, and color reproduction.

Bilateral Congenital Deafness in a White Bull Terrier; Brainstem Auditory Evoked Response Findings

  • Kang, Byeong-Teck;Lee, So-Young;Jung, Dong-In;Kim, Hyung-Joong;Woo, Eung-Je;Park, Hee-Myung
    • Journal of Veterinary Clinics
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    • v.25 no.6
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    • pp.506-509
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    • 2008
  • A 2-month-old, intact female white Bull Terrier presented because of suspected deafness. The coat color was predominantly white and the iris color, of both eyes, was brown. The dog did not respond to the owner's voice when the sound stimuli were presented outside of the visual field; however, the dog responded to visual gestures. The other physical, neurological, otoscopic, radiographic, and blood examinations were unremarkable. To assess the apparent deafness, brainstem auditory evoked responses (BAER) were recorded and analyzed in the dog with suspected deafness as well as a normal littermate. The response in the normal littermate consisted of a series of five wave peaks (I-V) with decreased amplitude and prolonged latency as the stimulus intensity decreased. The BAER from the dog suspected of deafness appeared as a flat line and did not reveal identifiable peaks that corresponded to those found in the normal littermate. Thus, congenital, sensorineural and bilateral deafness was confirmed by the BAER.

The Role of the Pattern Edge in Goldfish Visual Motion Detection

  • Kim, Sun-Hee;Jung, Chang-Sub
    • The Korean Journal of Physiology and Pharmacology
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    • v.14 no.6
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    • pp.413-417
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    • 2010
  • To understand the function of edges in perception of moving objects, we defined four questions to answer. Is the focus point in visual motion detection of a moving object: (1) the body or the edge of the object, (2) the leading edge or trailing edge of the object, (3) different in scotopic, mesopic and photopic luminance levels, or (4) different for colored objects? We measured the Optomotor Response (OMR) and Edge Triggering Response (ETR) of goldfish. We used a square and sine wave patterns with black and red stripes and a square wave pattern with black and grey stripes to generate OMR's and ETR's in the goldfish. When we used black and red stripes, the black leading edges stimulated an ETR under scotopic conditions, red leading edges stimulated an ETR under photopic conditions, and both black and red leading edges stimulated an ETR under mesopic luminance levels. For black and gray stripes, only black leading edges stimulated an ETR in all three light illumination levels. We observed less OMR and ETR results using the sine wave pattern compared to using the square wave pattern. From these results, we deduced that the goldfish tend to prefer tracking the leading edge of the pattern. The goldfish can also detect the color of the moving pattern under photopic luminance conditions. We decided that ETR is an intriguing factor in OMR, and is suitable as a method of behavioral measurement in visual system research.

Effect of Changes in Visual Response Speed, Functional Movement, Body Balance, and Lung Capacity after a 10-Week Body Stability Exercise Program for High School Male Taekwondo Athletes (10주간의 신체 안정화 운동프로그램이 초등학교 태권도 선수의 민첩성, 기능적 움직임, 균형, 폐기능에 미치는 효과)

  • Kang, Yang-Hoon;Kim, Chul-Seung
    • Journal of The Korean Society of Integrative Medicine
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    • v.9 no.3
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    • pp.111-124
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    • 2021
  • Purpose : The purpose of this study is to evaluate whether physical ability is improved by body stabilization, develop training methods to improve physical fitness factors suitable for body conditions, and provide future management and exercise materials to improve Taekwondo athletes' performance, after conducting the Body stabilization exercise (BSE) program on 22 elementary school Taekwondo athletes for 10 weeks to strengthen core muscles and evaluating Visual response speed test (VRST), Functional movement screen (FMS), Y-Balance test (YBT) and Vital capacity (VC). Methods : In order to examine the impact of the BSE program on Taekwondo athletes' VRST, FMS, YBT and VC this study conducted individual evaluations on all subjects, including VRST, FMS, YBT and VC before applying the programs, and compared exercise effects before and after the program, before and after exercise by a certain period. Results : After exercising, strength and quickness were improved significantly and reaction time was significantly shortened (p<.001). The total score of FMS was improved from 10.86±1.17 before to 11.68±0.99 after exercising, was statistically significant (p=.014). YBT was significantly improved from 91.11±4.84 before to 95.68±5.15 after exercising (p<.001). VC improved was statistically significant (p<.001). Conclusion : In conclusion, the BSE athletic program is expected to help Taekwondo athletes perform well by preventing and reducing injuries through the improvement of muscular strength, strength, speed, agility, step, kick, balance, flexibility, full body endurance and the combination of technical abilities.

The Investigation of the Relationship between Eye Blink and Visual Attention with Video Clip (영화클립을 이용한 눈깜빡임과 시각적 주의력과의 상관성 연구)

  • Kim, Sung Kyung;Kang, Min;Kang, Geon Ju;Park, Sujie;Shin, Young Seok;Jang, Dong Pyo
    • Journal of Biomedical Engineering Research
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    • v.35 no.4
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    • pp.99-104
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    • 2014
  • Generally, human eye blinks are closely associated with the cognitive state or visual attention such as attentional requirements on visual stimuli. These previous studies have reported that eye blinks are related to explicit visual attention using blink rate, pattern and blink timing across subjects. However, these results have been obtained in a well-controlled experimental settings. So, it would prove difficult to investigate human's natural response in a continuous and realistic situation. In our study, we measured the eye blink intervals while participants viewed a movie clip. And we analyzed the blink interval data for relationship between visual attention and eye blink intervals. 24 participants took part in two experimental sessions, first session to measure the IEBI while viewing the movie clip and second session to conduct a memory performance test using a self-questionnaire, which were spaced 3 weeks apart. The results indicate significantly higher memory performance at long IEBI period than short IEBI period while watching a movie clip(t = 3.257, df = 17, p < 0.005, 2-tailed). In addition, memory performance score significantly correlated with the IEBI value(spearman's rho = 0.40, N = 36, p < 0.01, 2-tailed). Our results suggest that IEBI is used to measure or assess visual attention while wiewing the movie that it is capable of simulating aspects of real-life experiences by visual attention. Thus, we expect IEBI to be used to measure or assess our visual attention, cognition, further emotion about not only movies, advertisements and other cultural contents but also cognitive science.

Subspace analysis of Poisson Model to extract Firing Characteristics in Visual Cortex (시각 피질의 발화 특성 추출을 위한 포아송 모델의 부공간 해석)

  • Lee, Youngseok
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.15 no.1
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    • pp.1-7
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    • 2022
  • It has been found through physiological experiments that the visual neurons constituting the human visual cortex do not respond to all visual stimuli, but to a visual stimuli with specific conditions. In order to interpret such physiological experiments, a model that can simulate the firing characteristics of neurons including a linear filter with random gain was proposed. It has been proven through experiments that subspaces are formed. To verify the validity of the implemented model, the distribution of values for two pixels randomly extracted from four different visual stimulus data was observed. The difference between the two distributions was confirmed by extracting the central coordinate value, that is, the coordinate value with the most values, from the distribution of the total stimulus data and the spike ignition stimulus data. In the case of the entire set, it was verified through experiments that the stimulus data generating spikes is a subset or subspace of the entire stimulus data. This study can be used as a basic study related to the mechanism of spikes in response to visual stimuli.

The Effect of Background Grey Levels on the Visual Perception of Displayed Image on CRT Monitor (CRT 모니터의 배경(背景) 계조도(階調度)가 영상의 시각인식(視覺認識)에 미치는 영향)

  • Kim, Jong-Hyo;Park, Kwang-Suk;Min, Byoung-Goo;Lee, Choong-Woong
    • Proceedings of the KOSOMBE Conference
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    • v.1991 no.05
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    • pp.18-21
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    • 1991
  • In this paper, the effect of background grey levels on the visual perception of target image displayed on CRT monitor has been investigated. The purpose of this study is to investigate the efficacy of CRT monitor as a display medium of image information especially in medical imaging field. Three sets of experiments have been performed in this study; the first was to measure the luminance response of CRT monitor and to find the best fitting equation, and the second was the psychophysical experiment measuring the threshold grey level difference between the target image and the background required for visual discrimination for various background grey levels, and the third was to develop a visual model that is predictable of the threshold grey level difference measured in the psychophysical experiment. The result of psycophysical experiment shows that the visual perception performance is significantly degraded in the range of grey levels lower than 50, which is turned out due to the low luminance change of CRT monitor in this range while human eye has been adapted to relatively bright ambient illumination.

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