• Journal of Broadcast Engineering
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• v.19 no.4
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• pp.478-490
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• 2014

In order to make 3-D display technique a better tool to provide viewers with realistic stereoscopic experience, various researches have been done in the many relevant fields. This psychophysical study was designed to investigate whether there was any difference in the perceptual processing between a dominant and non-dominant eye when a 3-D cue was provided exclusively to only one eye. We measured the reaction time for detecting a depth change by providing the viewer's each eyes with differential 3-D stimuli, which have systematical patterns. We obtained that there was a consistent 3-D perceptual performance when the 3-D cue was provided to the viewers' left eye regardless of their eye dominance. The result suggests that it might be a better technique to arrange the camera for left eye to carry 3-D cues to get the viewer's consistent 3-D perception.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.813-821
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• 1995

본 연구의 목적은 심리육체적 방법(Psychophysical method)을 이용하여 다양한 중량물운반 유형에서의 최대허용하중을 구하는 것이며 이의 타당성을 생리학적 방법(physiological method)을 이용하여 검토하는 것이다. 또한, 인체측정과 근력측정 자료를 이용하여 각 운반유형에서의 최대허용 하중을 예측하는 모형을 개발하고자 한다. 본 연구에서는 네 가지의 운반유형(Front carrying, One-hand side carrying, Two-hands side carrying 그리고 Back carrying)과 두가지의 보행 속도 (50.0 그리고 79.2 m/min)를 주요변수로 8가지의 작업에 대해 무작위로 선택하여 각 작업에 대한 최대허용 하중을 시간과 경비의 감소측면에서 폭넓게 사용되고 있는 심리육체적 방법으로 구하였다. 피실험자는 운반작업의 경력이 있는 실제 작업자군(n=7)과 그렇지 않은 학생군(n=10)으로 구분하여 건강한 남성 피실험자를 대상으로 연구를 실시하였다. 주실험전에 인체측정과 근력측정을 실시하였다. 이후에 심리육체적 방법과 생리학적 방법을 실시간(on-line)으로 실시하였다. 연구결과로 학생군과 작업자군간의 신체조건은 뚜렷한 차이를 보이지 않았으나 근력은 작업자가 우월하였다. 심리육체적 방법을 사용하여 도출된 최대허용 하중은 학생군, 작업자군 모두 운반유형의 변화에 따라 유의함을 보였다.(학생군:p=.0001 작업자군:p=.0001). 반면에 속도의 변화는 유의하지 않았다(학생군:p=.7954 작업자군:p=.9231). 또한 학생군과 작업자군 모두 Back carrying에서 가증 큰 하중을 운반하였다(학생군:8.16kg 작업자군:12.9kg). 심박수를 이용한 생리학적 연구에서는 평균 심박수가 거의 100 이하를 유지하므로써 피실험자들이 8시간 작업기준으로 보아 무리가 없는 최대허용 하중을 결정하였음을 보였다. 또한 각 운반작업에 대한 최대허용 하중을 예측하는 회귀모형을 제시하였다.

• Korean Journal of Cognitive Science
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• v.16 no.4
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• pp.243-254
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• 2005

Pulfrich effect implies the possibility that motion information is processed by the system that processes depth information, and this possibility by supported by various neurophysiological studies. Although Pulfrich effect is processed by the system that processes binocular disparity, the representative depth information, there has not been a psychophysical research to determine the characteristics of the interaction between Pulfrich effect and binorular disparity using a stimulus containing the two information sources. Present research examined the characteristics of the interacation between Pulfrich effect and binocular disparity by nenuring the depth and rotation direction of a rotating cylinder comprised of random dots under two different conditions: 1) consistent rendition where the Pulfrich effect and binocular disparity depth the depth and rotation direction of the cylinder in a consistent manner 2) inconsistent rendition where they did not. , The perceived depth of the cylinder in the consistent condition was larger than that in disparity/Pulfrich effect only condition. Interestingly, the perceived rotation direction of the cylinder in the inconsistent condition was modulated by the relative strength of the disparity and the Pulfrich effect. These results imply that binocular disparity and Pulfrich effect are processed by a common neurophysiological methanism.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.2
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• pp.19-25
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• 2018

A scientific and systematic approach for digitally representing colours is essential for improving image quality. Therefore, there is a need for objectively analysing such approaches. Studies regarding display systems, which can reflect human visual characteristics in the digital media environment, and associated international standards at the forefront, have already caused significant impact. Colour is one of the most important factors employed for evaluating the overall image quality of displays. The proposed study focusses on colour properties which are based on the characteristics of the human peripheral vision area, with the primary objective of reproducing digital colours which can simulate human visual characteristics in the digital media environment. The proposed study aims at identifying digital colour characteristics which can vary according to the level of background lightness and the size of colour stimuli. Based on the evaluation results obtained through psychophysical experiments, a method has been proposed for determining peripheral vision characteristics which vary according to the increasing size of a colour stimulus, thereby digitally reproducing them on displays.

• Journal of the Korea Society of Computer and Information
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• v.19 no.3
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• pp.155-161
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• 2014

The objective of this study is to weight analysis portable backpack system of infantry weapon systems for ergonomic design in manual materials handling tasks. For the product design, we analyzed the ergonomic guidelines and status of similar weapon systems by comparing the efficient operation performance provide for the basic data. Result of this study, the relationship between portability and mobility presented for schematic. In the short distance of the short biomechanical criterion, 1-2 hours in the middle of moving psychophysical criterion, 4 hour or more long-distance criterion applied for the physiological criterion for easy of trade-offs that need to be considered. This study suggests for 4 research items for infantry backpack system in manual materials handling tasks. Throughout the result of anthropometric populations, the 5%tile body weight for -0.91kg but 95%tile in 34.17kg considered to be margin for free, easy and efficient operation for the weight margin between portability and mobility in manual materials handling tasks.

• Journal of the Ergonomics Society of Korea
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• v.36 no.3
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• pp.213-219
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• 2017

Objective: The present study identified the minimum legible text size by an experiment for eight combinations of background and text colors, which will be used in designing visual information on group-view display (GVD). Background: Information on minimum legible text size is needed to design the visual information presented on GVD in a radioactive waste control room. Method: The experiment was conducted for 22 male participants (age: mean = 37, SD = 6.7; visual acuity: over 0.8) who were recruited by considering demographic characteristics of current control room operators. Eight combinations of background and text colors were considered and the minimum legible text size was determined for each combination by applying the method of limits, one of psychophysical methods. Results: The minimum legible text size was significantly different in accordance with the combination of background and text colors. Statistical analysis results showed that luminance contrast and color contrast between background and text influenced the minimum legible text sizes. Conclusion: This study concluded that the minimum legible text size is 8 minute of arc for various combinations of background and text colors. Application: The minimum legible text size identified in the present study can be utilized in designing visual information on GVD at the main control room in a radioactive waste facility.

• Korean Journal of Cognitive Science
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• v.10 no.3
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• pp.1-15
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• 1999

Based on known physiological and psychophysical results, a neural network model for visual selection, called FeaureGate is proposed. The model consists of a hierarchy of spatial maps. and the flow of information from each level of the hierarchy to the next is controlled by attentional gates. The gates are jointly controlled by a bottom-up system favoring locations with unique features. and a top-down mechanism favoring locations with features designated as target features. The present study focuses on the top-down mechanism of the FeatureGate model that produces results similar to Moran and Desimone's (1985), which many current models have failed to explain, The FeatureGate model allows a consistent interpretation of many different experimental results in visual attention. including parallel feature searches and serial conjunction searches. attentional gradients triggered by cuing, feature-driven spatial selection, split a attention, inhibition of distractor locations, and flanking inhibition. This framework can be extended to produce a model of shape recognition using upper-level units that respond to configurations of features.

• Journal of Broadcast Engineering
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• v.5 no.1
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• pp.10-22
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• 2000

In this paper, we present a texture description method as a standardization of multimedia contents description. Like color, shape, object and camera motion information, texture is one of very important information in the visual part of international standard (MPEG-7) in multimedia contents description. Current MPEG-7 texture descriptor has been designed to fit human visual system. Many psychophysical experiments give evidence that the brain decomposes the spectra into perceptual channels that are bands in spatial frequency. The MPEG-7 texture description method has employed Radon transform that fits with HVS behavior. By taking average energy and energy deviation of HVS channels, the texture descriptor is generated. To test the performance of current texture descriptor, experiments with MPEG-7 Texture data sets of T1 to T7 are performed. Results show that the current MPEG-7 texture descriptor gives better retrieval rate and fast and fast extraction time for texture feature.

• Proceedings of the Ginseng society Conference
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• 1984.09a
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• pp.215-223
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• 1984

Panax ginseng has often been suggested as a geriatric restorative. This study is a double blind crossover trial to test whether ginseng can improve function in subjects with the depression and reduced abilities associated with senescence. 49 screened subjects were given 1500 mg Korean Red ginseng and identical placebo each for ten days, with a washout period in between the dosages. Standard tests of mental function, neuromuscular reflexes, responsiveness, mood and well being were used. The subjects were somewhat better at the co-ordination and speed test ('number copying') but tests of concentration and memory ('Concentration', 'Paired Association', 'Digit Span' and 'Object Learning') gave equivocal results. There were small improvements in mood and well being ('Life Satisfaction' and 'General Health Questionnaire') while the subjects indicated increased energy, alertness and less sleep, but also less happiness on the daily analogue scales. The major result was a highly significant improvement in reactivity, speed and co-oridnation at the tapping test, and the visual, auditory and disjunctive reaction timer. These are the most objective and accurate tests used in this trial. It is therefore concluded that ginseng can increase function in senile individuals. This effect is most easily visualisable in objective psychophysical tests, rather than the more subjective memory and concentration tests.

• Journal of the Ergonomics Society of Korea
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• v.30 no.5
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• pp.671-681
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• 2011

Objective: The purpose of this study is to compare the workload level at each lower limbs posture and suggest the ergonomic workstation guideline for working period by evaluating the imbalanced lower limbs postures from the physiological and psychophysical points of view. Background: Many workers like welders are working in various imbalanced lower limbs postures either due to the narrow working conditions or other environmental conditions. Method: Ten male subjects participated in this experiment. Subjects were asked to maintain 3 different lower limbs postures(standing, squatting and bending) with 3 different working conditions(balanced floor with no scaffold, imbalanced floor with 10cm height of scaffold, and imbalanced floor with 20cm height of scaffold). EMG data for the 4 muscle groups(Retus Femoris, Vastus Lateralis, Tibialis Anterior, Gastrocnemius) from each lower limbs posture were collected for 20 seconds every 2 minutes during the 8 minutes sustaining task. Subjects were also asked to report their discomfort ratings of body parts such as waist, upper legs, lower legs, and ankle. Results: The ANOVA results showed that the EMG root mean square(RMS) values and the discomfort ratings(CR-10 Rating Scale) were significantly affected by lower limbs postures and working time(p<0.05). The correlation was analyzed between the EMG data and the discomfort ratings. Also, prediction models for the discomfort rating for each posture were developed using physical condition, working time, and scaffold height. Conclusion: We strongly recommend that one should not work more than 6 minutes in a standing or squatting postures and should not work more than 4 minutes in a bending posture. Application: The results of this study could be used to design and assess working environments and methods. Furthermore, these results could be used to suggest ergonomic guidelines for the lower limbs postures such as squatting and bending in the working fields in order to prevent fatigue and pain in the lower limbs body.