• Journal of the Korean Society for Precision Engineering
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• v.22 no.7 s.172
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• pp.200-207
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• 2005

This study compares two different methods of measuring brain-BOLD activation. By comparing two different methods of measurement i.e., one method calculating the neural activation area (the number of activated voxels), while the other measured the neural activation intensity (the mean intensity of selected activated yokels), this study identified the more precise method of measuring brain activation which results from the completion of a visuospatial task. 16 right-handed male college students (mean age 23.2 years) participated in this study as subjects. Functional brain images were scanned on them using a 3T MRI single-shot EPI method. No correlation was found between the levels of cognitive performance and number of activated yokels in the activated brain areas. However, a significant correlation was found between the levels of cognitive performance and the mean intensity of selected activated yokels in the parietal, frontal, and other areas. In conclusion, the method of mean intensity was considered a better index of brain activity rather than the activated yokels measurement method.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2003.11a
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• pp.1111-1115
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• 2003

본 연구에서는 일반 공기 중의 산소 농도(21％) 환경에 비해 외부에서 고 농도(30％)의 산소 공급이 인지 능력 중 특히 언어 능력에 어떠한 변화를 유발하는지 관찰하고자 한다. 9명의 오른 손잡이 남자 대학생을 본 연구의 실험 참여자로 선정하였다. 21％와 30％ 산소 농도를 각각 8L/min의 양으로 일정하게 공급할 수 있는 장치를 개발하여, 마스크를 통하여 실험 참여자에게 전달하면서 언어 과제를 수행하게 하였다. 동시에 3T MRI를 이용하여 뇌기능 영상을 획득하였다. 언어 능력 측정을 위해 28 문항을 포함하는 두 개의 문제지를 제작하였고, 과제 수행 결과로부터 정답률을 산출하였다. 21％에 비해 30％ 산소 농도에서 평균 정답률은 유의미한 증가를 하였고, 뇌 활성화 양도 증가하였다. 본 연구의 결과로부터 외부에서의 고농도의 산소 공급이 언어 능력 증가에 긍정적인 영향을 미친다는 결론을 도출할 수 있다.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.11
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• pp.183-186
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• 1995

• Investigative Magnetic Resonance Imaging
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• v.1 no.1
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• pp.66-74
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• 1997

fMRI, functional MRI introduced receently appears based on the gradient echo technique which is sensitive to the field inhomogeneity developed due to the local susceptibility changes of blood oxygenation and deoxygenation. There has been many variants of the basic gradient echo sequence which is sensitive to the local inhomogeniety, among others such as GRASS or SSFP to EPISTAR are the most commonly used gradient echo techniques. Common to all these gradient echo techniques is that the signal due to the susceptibility effects is generally decreased with increasing inhomogeneity due to the $T2^{*}$ effect or conventionally konwn as blood oxygenation level dependent(BOLD) effect. It is, also found that the BOLD sensitivity is also dependent on the imaging modes, namely whether the imaging is in axial, or coronal or sagittal mode as well as the directions of the vessels against the main magnetic field. We have, therefore, launched a systematic study of imaging mode dependent signal change or BOLD sensitivity as well as the signal changes due tothe tilting angle of the imaging planes. Study has been made for both TRFGE sequence and CGE sequence to compare the distinctions of the each mode since each technique has different sensitivity againsst susceptibility effect. Method of computation and both the computer simulations and their corresponding experimental results are presented.

• Journal of Biomedical Engineering Research
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• v.16 no.4
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• pp.425-430
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• 1995

The correlation technique has been widely used in ctRl data processing. The proposed CLT (clus- tering threshold) technique is a modified CCT (correlation coefficient threshold) technique and has many advantages compared with the conventional CCT technique. The CLT technique is explained by the following two steps. First, once the correlation coefficient map above the proper TH value is obtained using the CCT technique which is discrete and includes splash noise data, then the spurious pixels are rejected and the real neural activity pixels extracted using an nxn matrix box. Second, a clustering operation is performed by the two correction rules. The real neuronal activated pixels can be clustered and the false spurious pixels can be suppressed by the proposed CLT technique. The proposed CLT technique used in the post processing in ctRl has advantages over other existing techniques. It is especially proved to be robust in noisy environment.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.11a
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• pp.258-259
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• 2011

3DTV를 시청하는 경우 조절거리는 TV 화면까지의 거리에 해당하지만, 수렴거리는 좌 우 영상의 화면 시차에 따라 영상의 도출과 후퇴의 깊이가 변하게 되고 수렴거리와 조절거리에 불일치가 발생하게 된다. 3DTV의 입체영상을 시청할 때 발생하는 시각적 불편감은 이러한 수렴과 조절과정의 불일치가 가장 주된 원인으로 알려졌다. 본 연구에서는 입체영상의 시각적 자극으로 눈에서부터 시작된 시각피로감이 인체에 전해지는 단계, 즉 정보의 최종 통합기관인 뇌에 전달결과로서의 생체적 반응을 EEG 방법으로 측정하였다. 3DTV 시청 전 후의 뇌파측정과 뇌기능지수 분석에 의한 방법으로 실험한 결과 시각피로는 ${\delta}$, ${\theta}$, ${\alpha}$, SMR, ${\beta}$Low, ${\beta}$High 파 등 여러 종류의 뇌파 밴드에 영향을 미치고 있었다.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.1
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• pp.183-192
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• 2005

This study compared cerebral lateralization index based on the area of neural activation with that based on the intensity of neural activation. For this purpose, 8 right-handed male college students (the mean age - 23.5 years) and 10 right-handed male college students (the mean age - 25.1 years) participated respectively in researches on visuospatial and verbal task brain function. Functional brain images were taken from 3T MRI using the single-shot EPI method. The result of measuring cerebral lateralization index based on the area of neural activation suggested that the right hemisphere is dominant in visuospatial tasks and the left one is in verbal tasks. However, the dominance is not sufficient to locate the exact part of the brain for these tasks. When cerebral lateralization index was computed based on the intensity of neural activation, it was derived that the area of cerebral lateralization closely related to visuospatial tasks is the superior parietal lobe, and the area of cerebral lateralization closely related to verbal tasks is the inferior and middle frontal lobes. Thus, cerebral lateralization index by area based on the intensity of neural activation as proposed by this study can determine the dominance of the cerebrum by area, so is helpful for accurate and quantitative determination of cerebral lateralization.

• Journal of the Korean Data and Information Science Society
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• v.20 no.3
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• pp.541-550
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• 2009

This research attempted to find out any implications for strategies to design and develop the connections between the activities of the brain function and the fields of English learning (dictation, word level, speaking, word memory, listening). Thus, in developing the brain based learning model for the English education, attempts need to be made to help learners to keep the whole brain toward learning. On this point, this study indicated the significant results for the exclusive brain location and the brainwaves on the each English learning field by the quantitative EEG analysis. The results of this study presented the guidelines for the balanced development of the left brain and the right brain to train the specific site of the brain connected to the English learning fields. In addition, whole brain training model is developed by the quantitative EEG data not by the theoretical learning methods focused on the right brain training.

• Investigative Magnetic Resonance Imaging
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• v.9 no.1
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• pp.9-15
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• 2005

Purpose : This study attempted to investigate the effects of supply of highly concentrated $(30\%)$ oxygen on human ability of visuospatial cognition using time course data analysis of functional Magnetic Resonance Imaging (fMRI). Materials and Methods : To select an item set in the visuospatial performance test, two questionnaires with similar difficulty were developed through group testing. A group test was administered to 263 college students. Two types of questionnaire containing 20 questions were developed to measure the ability of visuospatial cognition. Eight college students (right-handed male, average age of 23.5 yrs) were examined for fMRI study. The experiment consisted of two runs of the visuospatial cognition testing, one with $21\%$ level of oxygen and the other with $30\%$ oxygen level. Each run consisted of 4 blocks, each containing control and visuospatial items. Functional brain images were taken from 37 MRI using the single-shot EPI method. Using the subtraction procedure, activated areas in the brain during visuospatial tasks were color-coded by t-score. To investigate the time course data in each activated area from brain images, 4 typical regions (cerebellum, occipital lobe, parietal lobe, and frontal lobe) were selected. Results : The average accuracy was $50.63{\pm}8.63$ and $62.50{\pm}9.64$ for $21\%\;and\;30\%$ oxygen respectively, and a statistically significant difference was found in the accuracy between the two types of oxygen (p<0.05). There were more activation areas observed at the cerebellum, occipital lobe, parietal lobe and frontal lobe with $30\%$ oxygen administration. The rate of increase in the cerebellum, occipital lobe and parietal lobe was $17\%$ and that of the frontal lobe, $50\%$. Especially, there were increase of intensity of BOLD signal at the parietal lobe with $30\%$ oxygen administration. The increase rate of the left parietal lobe was $1.4\%$ and that of the right parietal lobe, $1.7\%$. Conclusion : It is concluded that while performing visuospatial tasks, high concentrations of oxygen administration make oxygen administration sufficient, thus making neural network activate more, and the ability to perform visuospatial tasks increase.

• Journal of Gifted/Talented Education
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• v.15 no.2
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• pp.101-125
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• 2005

We applied functional magnetic resonance imaging (fMRI) techniques to examine whether general intelligence (g) could be assessed using a neurobiological signal of the brain. Participants were students in a national science academy and several local high schools. They were administered diverse intelligence (RAPM and WAIS) and creativity tests (TTCT-figural and TTCT-verbal). Forty of them were scanned using fMRI while performing complex and simple g tasks. In brain regions of greater blood flow in complex compared with simple g tasks, the gifted group with an exceptional g level was not significantly different from the average group with an ordinary g level: both of them activated the lateral prefrontal, anterior cingulate, posterior parietal cortices. However, the activation levels of the gifted group were greater than those of the average group, particularly in the posterior parietal cortex. Correlation analysis showed that the activity of the posterior parietal cortex has the highest correlation ($(r=0.73{\sim}0.74)$) with individual g levels and other regions also have moderate correlation ($(r=0.53{\sim}0.66)$). On the other hand, two-sample t test showed a striking contrast in intelligence tests scores between the gifted and the average group, whereas it did not show in creativity tests scores. These results suggest that it is within the bounds of possibility that a neurobiological signal of the brain is used in the assessment of the gifted and also suggest that creativity has to be given a great deal of weight on the assessment of the gifted.