• Annals of Clinical Neurophysiology
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• v.10 no.1
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• pp.13-24
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• 2008

Functional neuroimaging, especially positron emission tomography (PET) and functional magnetic resonance imaging (MRI), is the main tool that allows the unveiling of the neurovascular events during a migraine attack. In migraine with aura, functional neuroimaging has contributed greatly to the understanding of the fundamental pathophysiology of the visual aura, whereas in migraine without aura, the PET findings of brainstem activation suggest a pivotal role of brainstem in the generation of migraine headache. In addition, voxel-based morphometry (VBM) method has provided an insight into the morphometric changes of the brain, which might be considered as a consequence of repeated migraine attacks. In this article, I will briefly discuss the main neuroimaging findings pertaining to the pathophysiology of migraine.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2002.05a
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• pp.231-235
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• 2002

본 논문에서는 전문 안무가와 일반인들을 대상으로, 현대적 스타일의 독무와 임의적으로 움직이는 육면체를 제시할 때의 두뇌 활동 양상을 fMRI를 통하여 알아보았다. 피험자들은 총 8명으로 구성되었으며, 4명은 안무 전문가들, 4명은 동일한 연령대의 일반인들이었다. 피험자들은 시각 자극으로 제시되는 춤동작과 다양하게 변화하는 단순한 육면체의 움직임을 아무런 반응 없이 보는 과제를 수행하였다. 두 피험자 그룹 모두에서 육면체의 움직임보다 무용을 응시할 때 occipital cortex에서 더 큰 활성화를 보였고, 특히 좌측 STS와 angular gyrus사이의 경계선 영역, 그리고 좌측 fusiform gyrus에서는 안무가들이 무용을 볼 때 일반인들보다 더 높은 활성화를 나타내었다. STS/angular gyrus와 fusiform gyrus가 시각 자극의 의미 표상을 이해하는데 관련이 있고, angular gyrus가 사전적 의미 해석에 있어 중계적 역할을 하는 곳이며, fusiform gyrus는 사물을 지각하는데 있어서 보조 역할을 맡고 있다는 논의를 바탕으로, 무용가들은 그들이 지니고 있는 안무에 대한 전문적인 소견과 지식을 이용하여 몸의 움직임을 분석할 수 있고, 또 그것에서부터 어떠한 상징적인 의미까지 끌어내어 결과적으로 의미 추출의 과정에서 두뇌의 semantic network를 활성화시킨다고 볼 수 있다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.6 no.1
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• pp.11-19
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• 1994

An optimal design for Gifford-McMahon/Joule-Thomson(GM-JT) refrigerators was performed by a numerical method. The design goal was to meet the cooling requirement for MRI systems, which was 3 Watt at 4 K. A general cycle analysis program was written to calculate the cooling capacity of the GM-JT refrigerators for the givenstage GM refrigerator. The program was executed for a specific refrigerator with various design parameters. The optimal values for the maximum cooling were found for the sizes of the heat exchangers, the mass flow rate of helium, and the compression pressure.

• Annual Conference on Human and Language Technology
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• 1998.10c
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• pp.186-190
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• 1998

정상 피험자에 있어서 수행 성적의 차이를 보이는 음소적 단어 생성과 의미적 단어생성에 관련한 대뇌 피질의 활동양상의 차이를 밝히기 위해 피험자에게 단어 생성의 과제를 주면서 기능적 자기공명 영상술(functional magnetic resonance imaging, fMRI)을 시행하였다. 모두 7명의 정상인에서 음소 단서에 의한 단어생성은 의미 범주 단어에 의한 단어생성보다 광범위한 피질 영역의 활성화를 보였는데, 특히 bilateral posteroinferior temporal cortices, left premotor cortex, right cerebellum, bilateral superior parietal lobules에서 더 높은 활성화를 보였다. 이에 반하여 의미적 단어생성은 주로 bilateral posterior cingulate gyri에서 더 높은 활성화를 보였다. 이런 결과는 음소적 생성은 가능한 자모를 조합하여 어휘를 생성한 후 작업기억에 일시 저장시켜 놓고 verbal rehearsal 과정을 사용하여 단어 여부를 판별하는 것을 시사하며, 의미적 생성은 mental imagery를 통하여 시각적 인출 단서를 찾은 후, 의미 기억으로부터 단어를 직접 인출하는 것으로 보인다.

• Imaging Science in Dentistry
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• v.42 no.1
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• pp.13-18
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• 2012

Purpose : The aim of this study was to investigate the effect of the autologous blood injection (ABI) for chronic recurrent temporomandibular joint (TMJ) dislocation using magnetic resonance imaging (MRI). Materials and Methods : ABI was applied to 14 patients who had chronic recurrent TMJ dislocation. MRIs of the patients were taken and compared before and one month after the injection. Results : All of the patients had no dislocations of their TMJs on clinical examination one month after the injection. In the pre-injection, unilateral or bilateral TMJ dislocations were observed on MRIs in all patients. One month after the injection, TMJ dislocations were not observed in MRI evaluation of any patients. A significant structural change that caused by ABI was not observed. Conclusion : The procedure was easy to perform and it caused no foreign body reaction. However, it was unclear how the procedure prevented the dislocation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.280-283
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• 2015

This paper demonstrates a new radio frequency (RF) resonator at 3 T magnetic resonance imaging (MRI) system. An approach based on a split ring resonator (SRR) having effective metamaterial properties is investigated. Electromagnetic simulation results are compared for RF resonators and discussed in detail at 3 T. A new RF resonator has approximately 10% higher magnetic fields at the center of the human phantom than the previous RF resonator.

• Journal of Korean Foot and Ankle Society
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• v.7 no.1
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• pp.131-134
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• 2003

Most interdigital neuroma can be diagnosed clinically. But, diagnostic local injection method, sonography and magnetic resonance image(MRI) have been used as secondary tests for clinical confirmation or surgery. Recently, there have been active discussions on the method of interdigital neuroma diagnosis for which sonography or MRI is used. For finding out the location or the number of interdigital neuroma particularly in non-typical clinical manifestation or surgery, MRIs, which are exellent in tissue contrast, may be quite helpful. This case had an interdigital neuroma showing non-typical manifestation. MRIs were used for clinical diagnostic confirmation and finding out the location and the number of interdigital neuroma. Thus, the validity along with literary consideration is being reported.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.236-239
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• 1997

Snakes is an active contour model or representing image contours. To detect chest boundary on thoracic MRI sequences, we proposed a method based on modified greedy algorithm. Because thoracic MRI sequences have a spatial correlation, we added energy term related with spatial correlation to Snakes energy formulation. A measure of shape similarity called the BMD was used to evaluate the accuracy of the algorithm. The average BMD value or the modified algorithm's result is higher than greedy algorithm's.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.291-293
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• 1997

A new quadrature RF coil is designed for Breast MR Imaging. Quadrature RF coils for MRI have been useful to improve the signal-to-noise ratio (SNR) by "$\sqrt{2}$" using two orthogonal RF coils in combination. A modified Breast Quadrature coil is designed. It is a modified type of the high-pass birdcage coil. To reduce the field distortion, by using current feeding, the field pattern is optimized to achieve a quadrature circularly-polarized field pattern. The coil has been implemented for receive-only mode, and tested by phantom imaging. The experimental results show the utility of the proposed RF coil.

• Journal of Trauma and Injury
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• v.26 no.3
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• pp.229-232
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• 2013

Traumatic fracture-dislocations of the hip frequently result from high-energy injury, and hip dislocations are commonly associated with severe concomitant injuries. Sciatic nerve injury often accompanies traumatic fracture-dislocation of the hip, but neurologic examination at the time of injury is difficult in severely traumatized patients with decreased consciousness. We present such a case of multiple traumas with traumatic hip dislocation and sciatic nerve injury after reduction, and we found that magnetic resonance image (MRI) played an important role in developing a management plan.