• 방송공학회논문지
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• 제5권1호
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• pp.10-22
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• 2000

본 논문에서는 MPEG-7 표준 비쥬얼 분야 기술자에게 영상의 질감 정보의 표현 방법에 대해 다룬다. 질감 기술자는 멀티미디어 컨텐츠 표현에 대한 국제 표준에서 칼라, 윤곽, 객체나 카메라 움직임 등과 함께 중요한 비쥬얼 특징으로 다루어지고 있으며 표준화의 대상이 되고 있다. 본 논문에서는 현재 MPEG-7 표준안으로 잠정 채택된 휴먼 비쥬얼 시스템(Human Visual System, HVS)에 기반한 질감 기술자에 대하여 논한다. 이 방법은 라돈(Radon) 변환을 통하여 영상을 시각인지 특성에 맞게 변환하고, 뇌의 비쥬얼 피질(Visual Cortex)의 반응과 일치하게 다수개의 주파수 채널들로 질감을 분해한다. 그리고 각 채널들에서의 평균 에너지와 에너지의 편차가 영상의 질감 기술자로 추출한다. 본 논문에서 질감 영상 검색에 있어서 현재 MPEG-7 실험 데이터베이스인 T1∼T7에서 검색 율을 측정하였다. 실험결과 본 영상 질감 기술자 표현 방법은 모든 실험 데이터베이스에서 우수한 검색 성능과 빠른 특징 추출 능력을 보였다.

• 대한의용생체공학회:의공학회지
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• 제27권6호
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• pp.384-391
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• 2006

Variation of brain dynamics under Zen meditation has been one of our major research interests for years. One issue encountered is the inaccessibility to the actual meditation level or stage as a reference. In this paper, we propose an alternative strategy for investigating the human brain in response to external flash stimuli during Zen meditation course. To secure a consistent condition of the brain dynamics when applying stimulation, we designed a recording of flash visual evoked potentials (F-VEPs) based on a constant background EEG (electroencephalograph) frontal $\alpha-rhythm$ dominating activities that increase significantly during Zen meditation. Thus the flash-light stimulus was to be applied upon emergence of the frontal $\alpha-rhythm$. The alpha-dependent F-VEPs were then employed to inspect the effect of Zen meditation on brain dynamics. Based on the experimental protocol proposed, considerable differences between experimental and control groups were obtained. Our results showed that amplitudes of P1-N2 and N2-P2 on Cz and Fz increased significantly during meditation, contrary to the F-VEPs of control group at rest. We thus suggest that Zen meditation results in acute response on primary visual cortex and the associated parts.

• 영재교육연구
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• 제23권5호
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• pp.637-648
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• 2013

대뇌 피질과 지능과의 관련성은 다양한 방법으로 연구되어 왔으며, 지능 발현에 관여하는 뇌 영역이 속속 밝혀지고 있다. 이와 함께 소뇌도 대뇌처럼 언어와 기억, 정보 처리 등 다양한 인지 기능 수행에 밀접한 관련이 있다는 사실도 연구 결과 나타났다. 그러나 특정 과제 수행 때 지능별 대뇌와 소뇌 영역들의 활성도 차이를 밝힌 연구 결과는 찾기 어렵다. 본 연구는 공간유추 과제를 수행할 때 나타난 대뇌와 소뇌의 활성 영역을 탐색하고, 그 차이를 분석하였다. 건강한 81명(평균 16세 3개월)의 남자 청소년을 대상으로 WAIS 지능 검사를 하여 5개 지능 범주로 나누고, 도형 유추 과제를 수행하게 하면서 기능성자기공명영상기술(fMRI)로 뇌 영상을 촬영하였다. 그 결과 12개 뇌 영역에서 활성이 나타났는데, 대뇌 피질에서는 시각영역인 양측 하후두회 외에 양측 상두정회와 우측하전두회, 양측 미상회, 그리고 소뇌의 5개 세부 영역들이다. 특히 지능(IQ)이 높을수록 이들 영역의 활성이 강하게 나타났으며, 영재 중에서도 지능이 아주 높은 140~147 범주의 피험자들은 다른 지능그룹에 비해 월등히 높은 활성을 보였다. 이런 결과는 아주 높은 지능의 영재들의 뇌 활용 특징일 수 있기 때문에 '슈퍼 영재'들의 판별에 활용할 수 있을 것으로 기대된다.

• 한국콘텐츠학회논문지
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• 제16권8호
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• pp.427-434
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• 2016

본 논문은 인간이 인지할 수 있는 감각들 중 인체의 회전, 방향 변화 및 움직임의 정도를 알 수 있는 근감각에서 시각 및 청각 요소로의 변환 알고리즘을 이용하여 ARM Cortex-M4에 기반한 실시간 임베디드시스템으로 구현한 방법에 초점을 맞추었다. 근감각의 입력 방식으로는 자세측정장치(AHRS : Attitude Heading Reference System)를 이용해 롤(Roll), 피치(Pitch) 및 요(Yaw) 값을 실시간 획득하고, 이들 각각의 색을 표현하는 HSI 컬러 모델의 명도(Intensity), 색상(Hue) 및 채도(Saturation)에 대응하여 변환하였다. 최종 컬러신호는 HSI 에서 RGB 컬러모델로 변환하여 획득하였다. 또한, 근감각의 세 가지 입력 값들을 음을 표현하는 요소인 옥타브(Octave), 음계(Scale) 및 음의 세기(Velocity)에 대응하여 변환한 값을 MIDI(Musical Instrument Digital Interface)를 이용해 사운드를 합성하여 출력하였다. 출력 컬러신호 및 사운드를 분석한 결과, 근감각 입력 신호가 제안한 변환 방식에 따라 실시간으로 정확하게 색과 음으로 변환, 출력됨을 확인하였다.

• 한국초전도ㆍ저온공학회논문지
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• 제17권4호
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• pp.34-37
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• 2015

Developing Magnetoencephalography (MEG) based on Superconducting Quantum Interference Device (SQUID) facilitates to observe the human brain functions in non-invasively and high temporal and high spatial resolution. By using this MEG, we studied alpha rhythm (8-13 Hz) that is one of the most predominant spontaneous rhythm in human brain. The 8-13 Hz rhythm is observed in several sensory region in the brain. In visual related region of occipital, we call to alpha rhythm, and auditory related region of temporal call to tau rhythm, sensorimotor related region of parietal call to mu rhythm. These rhythms are decreased in task related region and increased in task irrelevant regions. This means that these rhythms play a pivotal role of inhibition in task irrelevant region. It may be helpful to attention to the task. In several literature about the alpha-band inhibition in multi-sensory modality experiment, they observed this effect in the occipital and somatosensory region. In this study, we hypothesized that we can also observe the alpha-band inhibition in the auditory cortex, mediated by the tau rhythm. Before that, we first investigated the existence of the alpha and tau rhythm in occipital and temporal region, respectively. To see these rhythms, we applied the visual and auditory stimulation, in turns, suppressed in task relevant regions, respectively.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.291-292
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• 1998

The purpose of the study was aimed to evaluate the BOLD contrast fMRI in occipital lobe and compare this imaging with metabolite changes based on $^1H$ MRS and MRSI before and after visual stimulation. As a result, the activation map were sucessfully produced by thresholding with minimum cross-correlate value of 0.45. In MRS, NAA/Cr ratio is almost same. however, latate was elevated almost 9 times higher than before activation. Lactate metabolic images were consistent with the BOLD effect map. The BOLD contrast fMRI is not enough to detect the activation area in human brain. so, the other modality was required such as lactate metabolic map.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.1009-1009
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• 2003

VIPER a new tool for the VIsual PERception of sound quality and for sound design will be presented. Requirement for the visualization of sound quality is a signal analysis modeling the information processing of the ear. The first step of the signal processing implemented in VIPER, calculates an auditory spectrogram by a filter bank adapted to the time- and frequency resolution of the human ear. The second step removes redundant information by extracting time- and frequency contours from the auditory spectrogram in analogy to contours of the visual system. In a third step contours and/or auditory spectrogram can be resynthesised confirming that only aurally relevant information were extracted. The visualization of the contours in VIPER allows intuitively to grasp the important components of a signal. Contributions of parts of a signal to the overall quality can be easily auralized by editing and resynthesising the contours or the underlying auditory spectrogram. Resynthesis of time contours alone allows e.g. to auralize impulsive components separately from the tonal components. Further processing of the contours determines tonal parts in form of tracks. Audible differences between two versions of a sound can be visually inspected in VIPER through the help of auditory distance spectrograms. Applications are shown for the sound design of several interior noises of cars.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.802-805
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• 2002

In the three-dimensional domain image expressed with two-dimensional slice images, such as fMRI images and multi-slice CT images, we propose the three-dimensional domain automatic segmentation for the purpose of extracting region. In this paper, we segmented each domain from the fMRI images of the head of people and monkey. We used the neural network "Pulse-Coupled Neural Network" which is one of the models of visual cortex of the brain based on the knowledge from neurophysiology as the technique. By using this technique, we can segment the region without any learning. Then, we reported the result of division of each domain and extraction to the fMRI slice images of human's head using "three-dimensional Pulse-Coupled Neural Network" which is arranged and created the neuron in the shape of a three-dimensional lattice.

• The Korean Journal of Physiology and Pharmacology
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• 제16권6호
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• pp.369-378
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• 2012

Analysis of synaptic plasticity together with behavioral and molecular studies have become a popular approach to model autism spectrum disorders in order to gain insight into the pathosphysiological mechanisms and to find therapeutic targets. Abnormalities of specific types of synaptic plasticity have been revealed in numerous genetically modified mice that have molecular construct validity to human autism spectrum disorders. Constrained by the feasibility of technique, the common regions analyzed in most studies are hippocampus and visual cortex. The relevance of the synaptic defects in these regions to the behavioral abnormalities of autistic like behaviors is still a subject of debate. Because the exact regions or circuits responsible for the core features of autistic behaviors in humans are still poorly understood, investigation using region-specific conditional mutant mice may help to provide the insight into the neuroanatomical basis of autism in the future.

• Clinical Endoscopy
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• 제55권5호
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• pp.594-604
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• 2022

Over the past decade, technological advances in deep learning have led to the introduction of artificial intelligence (AI) in medical imaging. The most commonly used structure in image recognition is the convolutional neural network, which mimics the action of the human visual cortex. The applications of AI in gastrointestinal endoscopy are diverse. Computer-aided diagnosis has achieved remarkable outcomes with recent improvements in machine-learning techniques and advances in computer performance. Despite some hurdles, the implementation of AI-assisted clinical practice is expected to aid endoscopists in real-time decision-making. In this summary, we reviewed state-of-the-art AI in the field of gastrointestinal endoscopy and offered a practical guide for building a learning image dataset for algorithm development.