• Sleep Medicine and Psychophysiology
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• v.9 no.2
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• pp.122-126
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• 2002

Objectives: The purpose of this study is to investigate the effects of the 37-hour sleep deprivation on visual discrimination using the Cybernetic Flicker Fusion Analyzer (FLIMK) and to see the correlation between this finding and various subjective scale scores. Methods: Twenty six subjects (20 men 6 women, $24.50{\pm}1.45$ years of age) participated in this study. Subjects remained awake for 37 hours under continuous surveillance. In the morning and evening of two study days, the FLIMK and the self-reporting scale of sleepiness, fatigue, anxiety and mood states were instituted. Results: In FLIMK, the flicker fusion threshold was significantly decreased after sleep deprivation (F=7.66, p=0.01). The number of trials (responses) before reaching fusion frequency threshold was significantly increased after sleep deprivation (F=13.16, p=0.001). The reduction of fusion frequency was correlated with the increase of sleepiness and fatigue (p<0.05), and the number of the trials was correlated with the scores of negative mood, anxiety, and fatigue (p<0.05). Conclusions: These results suggest that 37 hour total sleep deprivation cause the decrement in visual discrimination. The decrease of the fusion frequency after sleep deprivation was correlated with sleepiness and fatigue. Further study is needed to enlighten the biological mechanism of the decrement in visual function after sleep deprivation.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.4
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• pp.55-69
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• 1999

일반적으로 잉크젯 프린터는 농도에 대해 선형적인 계조재현 특성을 나타낸다. 그러나 인간 시각의 경우 농도에 선형적인 프린터 출력에 대하여 비선형적인 지각반응을 나타낸다. 즉 농도가 큰 패치(patch)에 대해서는 명도나 색차에 대한 변별력이 작으며 농도가 작은 패치에 대해서는 좀 더 예민한 변별력을 갖는다. 따라서 농도에 선형적인 프린터 출력은 시각적인 활성영역을 줄이므로 프린터에서 구별되는 계조의 범위가 좁아진다. 그러므로 본 논문에서는 인간의 시지각 특성과 매우 상관도가 높은 CIELAB 색공간을 이용하여 균등한 명도 변화 및 색차를 나타내도록 하는 프린터 계조재현 알고리즘을 제안한다. 이때 시각적으로 균등한 변화를 나타내는 프린터의 입력값을 찾기 위해 다층 퍼셉트론 신경망(multi-layer perceptron neural network, MLP)을 이용하였다. 신경망의 학습을 위해 계조에 따른 패치를 만들고, 프린터 구동입력신호 및 패치의 측정된 값으로 신경망을 학습하였다. 학습된 신경망으로 선형적인 출력을 내는 프린터 구동신호를 찾고 LUT(look-up table)를 이용하여 프린터 입력 신호를 역으로 보정하였다. 결과, 보정된 프린터의 출력이 선형적인 계조 변화를 보였고 변화가 인지되는 계조의 범위가 늘어났으며 실형상에 대한 실험에 있어서도 우수한 화질을 보였다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.11a
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• pp.74-79
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• 1998

본 연구에서는 한국인'의 정서 연구에 적합한 시각자극의 표준화를 위해서 한국정서사진체계(Korean Affects Picture System: KAPS)의 제작을 수행하면서 얻어진 결과를 간략히 보고하고자 한다. 총 210개의 시각자극 사진을 선정하여 슬라이드로 제작하고, 충남대학교 남녀 대학생 442명 (20-25세)을 대상으로 의미변별척도와 기본정서 평정척도를 사용하여 주관적 정서반응을 측정하였다 의미변별척도 평정치의 요인분석 결과 18개의 양극성 형용사는 3개의, 정서차원, 즉 즐거움, 각성도, 지배성 차원으로 구분되었다. 이는 국제정서사진체계 (IAPS)의 시각자극을 사용하여 미국인을 대상으로 수행한 연구 결과 및 한국인을 대상으로 수행한 연구 결과와 잘 일치하고 있다. KAPS에 포함되는 시각자각 수는 연구가 계속됨에 파라 지속적으로 확대되며, 실험방법 및 각자의 사진에 대한 세 차원(즐거움, 각성도, 통제력) 및 비연속 기본 정서(기쁨. 공포, 슬픔, 혐오, 놀람, 분노)에 관한 주관적 평정치를 포함하는 manual을 제작하여 정서연구자들에게 제공한다. 다른 연구자들에 의해서 얻어진 평정치 자료들도 계속해서 추가 보완될 것이다. 이를 통해서, 안으로 우리 나라에서의 정서 연구방법의 표준화 및 인구성과의 공유화를 위한 토대를 만들 수 있을 것으로 기대한다.

• Journal of the Korean Institute of Educational Facilities
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• v.18 no.3
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• pp.23-33
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• 2011

This study investigates the evaluation on simple comparison and seeking hidden figures works under LED illumination conditions according to three types of color temperatures (7000K, 5000K, 3000K) in the classroom, Since the objective of this study is to develop an electric lighting conditions suitable for students in the classroom, the performance of concentration and visual discrimination by students under three types of LED illumination conditions were analyzed. The 4 kinds of simple tests concerning with concentration and 2 types of tests for visual discrimination were developed, and test results under natural light and LED illumination by 3 types of color temperatures were analyzed. There were differences on concentration as well as visual discrimination performance in most cases by t-test ($p{\leq}0.05$). For further analysis among three types of color temperatures and natural light, ANOVA tests were performed. The test results shows that illumination condition plays an important role when students try to concentrate on simple comparison of characters, figures or colors and seek hidden figures. The experimental results of this study might be applied to designing better luminous environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.8B
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• pp.1161-1167
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• 2001

본 논문에서는 칼라 영상에 대한 인간 시각 특성과 무채색으로부터 정보를 추출하여 칼라 정지 영상에 효과적으로 워터마크 신호를 삽입하는 방법을 제안하였다. 워터마크는 이진 워터마크를 사용하였으며, 일반적으로 인간 시각 체계 특성에서 무채색(achromatic) 신호보다 유채색(chromatic) 신호에 대한 변별력이 떨어지는 특성을 이용하여 입·출력 장치로 획득된 RGB 좌표계의 칼라 정지 영상을 무채색 성분과 유채색 성분으로 완벽히 분리되는 다른 좌표계로 변환하여 워터마크를 유채색 포화도 성분에 삽입한다. 워터마크를 검출하는 과정은 원영상을 사용하지 않고 유채색 포화도 성분의 변경 형태를 추정하여 삽입된 워터마크를 검출 가능하였다. 실험 결과 특히 비가시성 특성 부분에서는 기존 방법들과 비교할 때 향상된 결과를 얻을 수 있었으며 강인성 또한 좋은 결과를 얻었다.

• Science of Emotion and Sensibility
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• v.7 no.3
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• pp.15-25
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• 2004

The regression analysis and Adaptive -Network based Fuzzy-inference system (ANFIS) were applied to the explanation on human's visual texture of cotton fabrics with 7 mechanical properties. The ANFIS uses the structure with fuzzy membership function and neural network. The results obtained by the statistical analysis through the coefficient of correlation and regression analysis showed that subjective texture had a linear relationship with mechanical properties. But It had a relatively low coefficient of determination and was difficult that the statistical analysis explained other relationship with the exception of a lineality and interaction among mechanical properties. Comparing the statistical analysis, the ANFIS was an effective tool to explain human's non-linear perceptions and their interactions. But to apply ANFIS to human's perceptions more effectively, it is necessary to discriminate effective input variables through controlling the properties of samples.

• Journal of Gifted/Talented Education
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• v.17 no.1
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• pp.1-26
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• 2007

The purpose of this study was to develop a math test for identification of the mathematically gifted on the basis of their math creative problem solving ability and to evaluate the goodness of the test. Especially, testing reliability and validity of scoring method on the basis of fluency only for evaluation of math creative problem solving ability was one of the main purposes. Ten closed math problems and 5 open math problems were developed requiring math thinking abilities such as intuitive insight, organization of information, inductive and deductive reasoning, generalization and application, and reflective thinking. The 10 closed math test items of Type I and the 5 open math test items of Type II were administered to 1,032 Grade 7 students who were recommended by their teachers as candidates for gifted education programs. Students' responses were scored by math teachers. Their responses were analyzed by BIGSTEPS and 1 parameter model of item analyses technique. The item analyses revealed that the problems were good in reliability, validity, item difficulty and item discriminating power even when creativity was scored based on the single criteria of fluency. This also confirmed that the open problems which are less-defined, less-structured and non-entrenched were good in measuring math creative problem solving ability of the candidates for math gifted education programs. In addition, it was found that the math creative problem solving tests discriminated applicants for the two different gifted educational institutions.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.1
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• pp.118-124
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• 2001

In this paper, we proposed the novel digital watermarking for color still image using the characteristics of human visual system and the distribution of DCT coefficients. We insert watermark signal in the chromatic components of YCrCb color space according the characteristics of the human visual system that chromatic component are less sensitive than achromatic components. In order to extract the watermark signal, we use the relationship among the DCT coefficients of watermarked image without using original one. Simulation results show that the proposed watermarking method is better quality on invisibility than the conventional methods.

• 한국노년학
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• v.31 no.3
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• pp.641-652
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• 2011

The purpose of this study was to investigate the ability of visual-motor integration (VMI) in elderly patient with diabetes mellitus(DM). Male elderly (from 65 to 70 years old) with DM and non-DM disease were participated in this study. Participants were divided into three group (n=30 in each group): the control group, non-DM group, and DM group. Data were collected through VMI-3R questionnaires and interviews. Statistical differences among groups were determined by one-way ANOVA followed by Duncan Post-hoc test and results were expressed the mean ± S.D. or percentage (%). The present results showed that the score of both VMI 24 and VMI 50 in DM group were statistically lower than both the control and Non-DM groups. Also, the lower rate of correct and higher rate of error in VMI-3R was observed in DM group compared to both the control and Non-DM groups. The item analysis of VMI-3R revealed that the most higher rate of error was observed in item 24 in all groups. Based on these results, this study suggests that DM might aggravate the function of visual-motor integration in male elderly.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.11 no.1
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• pp.91-99
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• 2000

Objectives：Present study developed the computerized ADHD Diagnostic System(ADS) in order to diagnose ADHD and evaluate treatment effect of it, and conducted a standardization study for ADS. Methods：The normative group was composed of 847 children and adolescents between the age of 5 and 15(boy 429, girl 418) living in the areas of Seoul, Kyunggi-do, and Kangwon-do. 30 ADHD children with age ranged 7 to 9 years were participated present study to evaluate the validity of ADS. To establish the norms for diagnosing ADHD, the means and standard deviations of normative group were used to calculate T-scores for each age group. Results：The reliability coefficient of ADS(Cronbach's ${\alpha}$) was .85. There were significant differences in the measures of ADS except commission error between the normal and the ADHD groups. Three factors were extracted through factor analysis of ADS, which were labelled 'inattention', 'slow information processing' and 'impulsivity'. Discriminant analysis showed that ADS significantly discriminate the normal and the ADHD groups. Percentage of correct classification by ADS variables was 96.7%. Conclusion：These results put together strongly support the reliability and validity of ADS as a diagnostic instrument for ADHD.