• Journal of IKEEE
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• v.25 no.4
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• pp.679-688
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• 2021

Gait is an evaluation index used in various clinical area including brain nervous system diseases. Signal source localizing and time-frequency analysis are mainly used after extracting independent components for Electroencephalogram data as a method of measuring and analyzing brain activation related to gait. Existing treadmill-based walking EEG analysis performs signal preprocessing, independent component analysis(ICA), and source localizing by merging data after the multiple EEG measurements, and extracts representative component clusters through inter-subject clustering. In this study we propose an analysis method, without merging to single dataset, that performs signal preprocessing, ICA, and source localization on each measurements, and inter-subject clustering is conducted for ICs extracted from all subjects. The effect of data merging on the IC clustering and time-frequency analysis was investigated for the proposed method and two conventional methods. As a result, it was confirmed that a more subdivided gait-related brain signal component was derived from the proposed "non-merging" method (4 clusters) despite the small number of subjects, than conventional method (2 clusters).

• Progress in Medical Physics
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• v.23 no.3
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• pp.127-137
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• 2012

A conversing beam is firstly designed for radiosurgery by a neurosugern Lars Leksell in 1949 with orthogonal x-rays tube moving through horizontal moving arc to focusing the beam at target center. After 2 decades he composits 201 source of the Co-60 for gamma knife which beams focused at locus. Sveral linac-based stereotactic radiosurgery using the circular collimated beam which size range for 0.4~4.0 cm in a diameter by non-coplanar multiarc have been developed over the decades. The irregular lesions can be treated by superimposing with several spherical shots of radiation over the tumour volume. Linac based techniques include the use of between 4 and 11 non-co-planar arcs and a dynamic rotation technique and use photon beam energies in the range of 6~10 MV. Reviews of the characteristics of several treatment techniques can be found in the literature (Podgorsak 1989, Schell 1991). More in recent, static conformal beams defined by custom shaped collimators or a mini- or micro-multileaf collimator (mMLC) have been used in SRS. Finally, in the last few years, intensity-modulated mMLC SRS has also been introduced. Today, many commercial and in-house SRS programs have also introduced non-invasive immobilization systems include the cyberknife and tomotherapy and proton beam. This document will be compared the characteristics of dose distribution of radiosurgery as introduced gamma knife, BrainLab include photon knife in-house SRS program and cyberknife in currently wide used for a cranial SRS.

• Journal of the Korean Society of Radiology
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• v.82 no.3
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• pp.626-637
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• 2021

Purpose To explore cerebrovascular reservoir (CVR) and arterial transit time (ATT) changes using acetazolamide-challenged multi-phase arterial spin labeling (MP-ASL) perfusion-weighted MRI in chronic cerebrovascular steno-occlusive disease. Materials and Methods This retrospective study enrolled patients with chronic steno-occlusion who underwent acetazolamide-challenged MP-ASL between June 2019 and October 2020. Cerebral blood flow, CVR, basal ATT, and ATT changes associated with severe stenosis, total occlusion, and chronic infarction lesions were compared. Results There were 32 patients (5 with bilateral steno-occlusion) in our study sample. The CVR was significantly reduced during total occlusion compared with severe stenosis (26.2% ± 28.8% vs. 41.4% ± 34.1%, respectively, p = 0.004). The ATT changes were not significantly different (p = 0.717). The CVR was marginally lower in patients with chronic infarction (29.6% ± 39.1% vs. 38.9% ± 28.7%, respectively, p = 0.076). However, the ATT was less shortened in patients with chronic infarction (-54 ± 135 vs. -117 ± 128 ms, respectively, p = 0.013). Conclusion Acetazolamide-challenged MP-ASL provides an MRI-based CVR evaluation tool for chronic steno-occlusive disease.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.61-62
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• 2022

알츠하이머성 치매는 현존하는 치료법이 없어 경도인지장애 단계에서의 예방이 중요하다. 지금까지의 알츠하이머 연구는 대부분이 뇌영상 마커와 뇌척수액 마커에 집중되어 있었으며, 경도 인지 장애 단계에서의 탐색은 더욱 적었다. 이러한 점에서 혈액 유전자 발현을 이용한 경도 인지장애 단계 예측은 인지 능력에 따른 관련 유전자 식별과 접근 가능한 진단 및 치료 바이오 마커 탐색에 기여할 수 있다. 그러나 유전자 발현 데이터의 경우 환자 수에 비해 높은 차원을 가지기 때문에 과적합을 막고 질병 관련 유전자를 식별하기 위해서는 데이터에서의 의미 있는 차원만을 뽑아내는 차원 축소가 선행되야 한다. 본 연구는 유전자 발현데이터에서의 인지장애 분류를 위해 차원 축소기법과 신경망을 적용하여 인지 장애 정도를 예측하였다. 그 결과, Lasso 이용 차원축소와 신경망을 이용하여 97%의 정확도로 정상과 조기 경도 인지장애, 후기 경도 인지장애 환자를 분류 할 수 있었으며, 더 적은 차원에서도 분류가 가능했다. 이는 혈액 유전자 발현을 이용해 경도 인지장애 단계를 예측한 첫 번째 연구이며, 인지능력 저하에 따른 혈액 유전자 발현의 연관성을 확인하고 향후 조기 진단, 치료 표적 탐색에 기여한다.

• Cartoon and Animation Studies
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• s.35
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• pp.1-27
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• 2014

This study is a process of studying an alternative educational model and a preceding analysis process of the study where a teaching method considering the brain function, learning and creative mechanism is applied with a perspective of effectively increasing the animation drawing ability. Recently, studies in each field of study is not simply limited to one major but are attempting to produce subdivided integrated educational contents through integrated study activities with other fields. It is because for any field, it has a complex structure of humanistic experience and this is the same for artistic fields. Especially, in the field of animation, a specialized area is subdivided so when looking only at the education related to the drawing, the items required for expertise should be clarified and the development of a systematic educational method is required. Therefore in this study, a literature study result to design the educational model suitable for professional characteristics of animation education method is proposed. The study aims to conceptualize and categorize the meaning of drawing that can refine the basic ability for education of animation field to suit the characteristics of majoring field. Afterwards, the components are derived through re-established concept of drawing and categories, and this becomes the basis for the process of materializing the study goal which is the follow-up work. As a result, the components are examined by defining the meaning of drawing as the motion drawing due to the characteristics of the picture contents field, and used as a basis for planning the educational model applied with brain scientific creative-learning principles.

• Korean Journal of Cognitive Science
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• v.22 no.4
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• pp.347-364
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• 2011

In this paper, we propose a automatic image bases extraction method for visual image reconstruction from brain activity using Non-negative Matrix Factorization (NMF). Image bases are basic elements to construct and present a visual image. Previous method used brain activity that evoked by predefined 361 image bases of four different sizes: $1{\times}1$, $2{\times}1$, $1{\times}2$, $2{\times}2$, and $2{\times}2$. Then the visual stimuli were reconstructed by linear combination of all the results from these image bases. While the previous method used 361 predefined image bases, the proposed method automatically extracts image bases which represent the image data efficiently. From the experiments, we found that the proposed method reconstructs the visual stimuli better than the previous method.

• The Mathematical Education
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• v.55 no.3
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• pp.383-396
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• 2016

This study investigated highschool students' brain waves on functional tasks such as a transition(F task) from equation to graph and the other transition(G task) vice versa. A total of 39 students participated in the study who attended a high school located in Gyunggi province. These students were divided into two groups, HMA and LMA by MASS test revised by Ko, & Yi (2012). The functional tasks for the stroop task to measure EEG were provided from a previous study, Seok(2015). The results indicated two groups on G tasks showed deeper and wider brain waves which demonstrated G tasks were more difficult than F tasks. However, HMA group had an effect of the non-psychological program which had given more chances on G tasks rather than F tasks within Students' Zone of Proximal Development. Also, HMA group's brain waves had more ranges in amplitude and width of waves. These results imply that the characteristics of students' brain waves with math anxiety are consistent to the previous studies.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.219-224
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• 2019

Textbooks with a lot of numerical information, such as the year, need to apply the mnemonic system. The mnemonic-system in numbers are used in many ways, such as dots, lines, and bars, and information images serve as symbols to help memory. The memory structure of the brain is more efficient in providing more information than just numbers. Previous studies have suggested graphical or arrayed image algorithms for mobile environments. In this study, we would like to link additional information related to figures with original data by selecting a subject with a lot of numerical information. We propose unique processes in mobile environments and evaluate the numerical algorithms to link meaning.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.3
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• pp.226-232
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• 2016

The research for the improvement in math and science scores is active by the brain exercises, stress reliefs, and emotion sensitized illuminations. This principle is based on the following facts that the most effective brain turns are supported with the circumstances not only when the brain wave should keep stability and comfort in science criticism, but also when minimized stress and comfortable illumination should be adjusted in solving math problem. In this paper, in order to effectively learn mathematics and science, the most optimized simulating tests in learning conditions are conducted by using a stress relief. However, depending on the users' tastes, the effectiveness on favorite music or colors therapy have no convergency but many differentiations. Therefore, in this paper, in order to solve this problem, the proposed optimal illumination and music therapy treatment using fuzzy inference method.

• Journal of Broadcast Engineering
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• v.27 no.5
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• pp.738-750
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• 2022

In this study, we reviewed and discussed whether auditory stimuli with short length can evoke emotion-related neurological responses. The findings implicate that if personalized sound tracks are provided to XR users based on machine learning or probability network models, user experiences in XR environment can be enhanced. We also investigated that the arousal-relaxed factor evoked by short auditory sound can make distinct patterns in functional connectivity characterized from background EEG signals. We found that coherence in the right hemisphere increases in sound-evoked arousal state, and vice versa in relaxed state. Our findings can be practically utilized in developing XR sound bio-feedback system which can provide preference sound to users for highly immersive XR experiences.