• Psychiatry investigation
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• 제15권11호
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• pp.1087-1093
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• 2018

Objective Posttraumatic stress disorder (PTSD) is distinct from anxiety disorders in its etiology and clinical symptomatology, and was reclassified into trauma- and stressor-related disorders in DSM-5. This study aimed to find neurophysiological correlates differentiating PTSD from anxiety disorders using resting-state quantitative electroencephalography (qEEG). Methods Thirty-six patients with either PTSD or acute stress disorder and 79 patients with anxiety disorder were included in the analysis. qEEG data of absolute and relative powers and patients' medication status on the day of qEEG examination were obtained. Electrodes were grouped into frontal, central, and posterior regions to analyze for regional differences. General linear models were utilized to test for group differences in absolute and relative powers while controlling for medications. Results PTSD patients differed from those with anxiety disorders in overall absolute powers [F(5,327)=2.601, p=0.025]. Specifically, overall absolute delta powers [F(1,331)=4.363, p=0.037], and overall relative gamma powers [F(1,331)=3.965, p=0.047] were increased in PTSD group compared to anxiety disorder group. Post hoc analysis regarding brain regions showed that the increase in absolute delta powers were localized to the posterior region [F(1,107)=4.001, p=0.048]. Additionally, frontal absolute gamma powers [F(1,107)=4.138, p=0.044] were increased in PTSD group compared to anxiety disorder group. Conclusion Our study suggests increased overall absolute delta powers and relative gamma powers as potential markers that could differentiate PTSD from anxiety disorders. Moreover, increased frontal absolute gamma and posterior delta powers might pose as novel markers of PTSD, which may reflect its distinct symptomatology.

• 한국자동차공학회논문집
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• 제8권4호
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• pp.177-185
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• 2000

The deformation characteristics is one of the major factors to resume the crash configuration in collision accident reconstruction. Crash analysis are carried out using finite element method and body stiffness equations representing force-deformation relationship are derived, Two different crash conditions : 1) frontal barrier impact 2) frontal impact between cars are given for the derivation of the equations. The stiffness coefficient of equation by method 2) is larger than that by method. 1). Crash analysis between two vehicles is accomplished with three crash angles and three velocities for each angle condition. The deformations are measured for six selected points and deformation energies are calculated using the derived equations. Equation by method 2) results in better estimation of deformation energy than that by method 1) for all crush configurations. The estimated energies can be utilized as one of indices to identify the type of the collision accident result.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.926-929
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• 2006

Some features of vertical structure of the frontal interaction zone of the warm Kuroshio Current and cold Oyashio Current are known from 1930 from analysis of ship data. Ship data however do not allow carrying out the area detailed survey opposite to satellite infrared (IR) observations which possess by high spatial and temporal resolution. Analysis of NOAA AVHRR IR images demonstrated that process of formation and development of the Kuroshio warm core rings is highly complex. They are formed as a result of development of anticyclonic meanders of the warm Kuroshio waters and spin off them from the current. Joint analysis of thermal infrared images and altimetry data has also indicated that interaction of eddies to the frontal zone plays a crucial role in formation of large eddies moving to the Southern Kuril region.

• 자동차안전학회지
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• 제12권1호
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• pp.39-45
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• 2020

The express/intercity bus models have been developing for wheelchair users to provide the preferable long-distance travels by the Korean government research. In the previous studies, evaluation method was set up for the wheelchair users' safety and the study for wheelchair occupants' safety was performed under various crash loadings mimic to real accidents, frontal crash, side impact and rollover, etc. This study was focused on the evaluation of occupant behaviors and injuries (head and chest) during vehicle impact loading cases in order to ensure the safety of wheelchair passengers in the bus. The occupant response and belt loading data during the sled FE simulation were compared with those of the sled test. The simulation results showed overall safety tolerances of wheelchair occupants under the severe frontal deceleration, side impact loading based on the FMVSS 214 configuration and bus rollover loading.

• 한국기계가공학회지
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• 제21권1호
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• pp.15-21
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• 2022

Collision analysis involving a vehicle frame that includes a battery and a battery case was performed using a carbon fiber composite material (CFRP) and a glass fiber-reinforced plastic (GFRP), which are lightweight materials. Three types of collisions were analyzed: frontal collisions, partial frontal collisions, and side collisions. The maximum stress and deformation levels were measured for each case. To evaluate the stability of ignition and explosion potential of the battery, the maximum stress of the frame was measured before measuring the direct stress to confirm whether the collision energy was sufficiently absorbed. The deformation level of the battery case was measured to confirm whether the battery case affects the battery directly.

• 대한치과교정학회지
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• 제39권5호
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• pp.289-299
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• 2009

본 연구는 3차원 콘빔CT 영상을 이용하여 2차원 정모두부방사선사진영상 형성 시 두부자세재현기(Head Posture Aligner, HPA)를 이용한 경우와 이용하지 않은 경우를 비교분석함으로써 HPA의 유용성을 평가하기 위하여 시행되었다. 성인 30명을 대상으로 먼저 일반적인 방법으로 콘빔CT 영상을 채득한 후 HPA를 이용하여 일정한 두부자세를 재현한 상태에서 또 하나의 콘빔CT 영상 및 정모두부방사선사진을 촬영하였다. 3차원 영상프로그램을 이용하여 HPA를 이용하지 않은 경우와 HPA를 이용한 경우 각각에서 2차원 정모두부방사선사진영상을 형성한 다음 각각의 투사도를 작성하고 실제로 HPA를 이용하여 촬영된 정모두부방사선사진 투사도와의 차이를 비교하였다. 거리 및 각도를 나타내는 여러 계측치를 비교분석한 결과 HPA를 이용하지 않은 경우에는 다수의 계측항목에서 실제 정모두부방사선사진과 유의한 차이를 보인 반면 HPA를 이용한 경우에는 모든 항목에서 통계적 유의차를 보이지 않았다. 아울러 실제 정모두부방사선사진과의 상관관계를 알아보기 위해 상관분석을 시행한 결과 HPA를 이용한 경우가 그렇지 않은 경우보다 모든 항목에서 높은 상관성을 보였다. 본 연구 결과는 3차원 콘빔CT 영상을 이용하여 2차원 정모두부방사선사진영상 형성 시 정확한 영상 획득을 위해서는 콘빔CT 촬영 시 HPA의 사용이 필요함을 시사하였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제38권
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• pp.49.1-49.9
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• 2016

Background: The aim of this report is to present a new reference for aesthetic mandible surgery using three-dimensional cone-beam computed tomography-based treatment planning for orthognathic surgery which can be implemented in surgical planning and perioperative procedure. Methods: To make an objective standard for evaluating aesthetic mandibular outline, we make an aesthetic scoring criteria with consideration of asymmetry, broad mandibular border line, and prominent mandibular angle. Two maxillofacial surgeons and two orthodontists rated their aesthetical evaluation from 1 to 5. Experimental group consisting of 47 female and 38 male patients who had rotational orthognathic two-jaw surgery from 2010 to 2011 were chosen according to aesthetic scoring done by two maxillofacial surgeons and two orthodontists. A high aesthetic score (${\geq}16$) means the facial contour is symmetric, with no broad and narrow aesthetic mandible frontal profiles. Control A group consisted of ten female and ten male patients who had no orthognathic surgery experience and low aesthetic score (${\geq}10$). Control B group consisted of ten female and ten male patients who had no orthognathic surgery experience and had anaesthetic mandibular frontal profile and a high aesthetic score (${\geq}16$). The three-dimensional image of the patient was taken from dental cone-beam CT (DCT) scanning (experimental group and control A group: 6 months DCT after surgery, control B group: 1st visit DCT). Each DCT was reformatted to reorient the 3D image using 3D analyzing program (OnDemand3D, cybermed Inc, CA, USA). After selection of 12 landmarks and the construction of reoriented horizontal, vertical, and coronal reference lines, 15 measurements were taken in 3D analysis of frontal mandibular morphology. Afterwards, horizontal and vertical linear measurements and angular measurements, linear ratio were obtained. Results: Mean $Go^{\prime}_{Rt}-Me^{\prime}-Go^{\prime}_{Lt}$ angular measurement was $100.74{\pm}2.14$ in female patients and $105.37{\pm}3.62$ in male patients. These showed significant difference with control A group in both genders. Ratio of $Go^{\prime}_{Rt}-Go^{\prime}_{Lt}-Me^{\prime}$ length to some linear measurements (ratio of $Me^{\prime}-Cd^{\prime}_{Rt}Cd^{\prime}_{Lt}$ to $Me^{\prime}-Go^{\prime}_{Rt}Go^{\prime}_{Lt}$, ratio of $Me^{\prime}-Go^{\prime}$ to $Me^{\prime}-Go^{\prime}_{Rt}Go^{\prime}_{Lt}$, ratio of $Go^{\prime}_{Rt}-Go^{\prime}_{Lt}$ to $Me^{\prime}-Go^{\prime}_{Rt}Go^{\prime}_{Lt}$) showed significant difference with control A group in both genders. Conclusion: This study was intended to find some standard measurement of mandible frontal view in 3D analysis of aesthetic patient. So, these potential measurement value may be helpful for orthognathic treatment planning to have more aesthetic and perspective outcomes.

• 한국방사선학회논문지
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• 제18권2호
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• pp.73-81
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• 2024

본 연구는 기분 장애(mood disorder) 환자들과 정상 대조군간의 대뇌 피질 두께를 측정 하여 구조적 이상을 비교하였다. 2020년 9월부터 2022년 8월까지 경상남도 양산 P 병원 정신건강의학과에서 기분 장애 진단을 받은 44명과 이상 병변이 없는 정상인 59명을 대상으로 후향적 연구를 시행하였다. 자기공명영상(MRI) 검사 후 획득한 3D-T1 MPRAGE 영상을 이용하였고, FreeSurfer 소프트웨어를 사용하여 대뇌 피질 두께를 측정하였다. 통계분석은 독립표본 t-검정을 이용하여 두 그룹간 평균의 차이를 측정하고, cohen's d 검정을 통해 두 그룹간 평균 차이의 크기를 평가하였다. 또한, 측정된 평균 피질 두께와 환자의 양성·음성증상(Positive and Negative Syndrome Scale, PANSS)간의 상관관계를 분석하였다. 기분장애 환자는 정상대조군에 비해 양측 상전두이랑(both superior frontal), 주둥이 중전두이랑(both rostral middle frontal), 꼬리 중전두이랑(both caudal middle frontal), 하전두이랑 주름 세곳(both pars opercularis, pars orbitals, pars triangularis), 상측두이랑(both superior temporal), 하측두이랑(both inferior temporal), 외측안와전두피질(both lateral orbito frontal), 내측안와전두피질(both medial orbito frontal), 방추형이랑(both fusiform), 후대상피질(both posterior cingulate), 대상이랑의 협부(both isthmus cingulate), 상두정수리소엽(both superior parietal), 하두정엽(both inferior parietal), 변연상이랑(both supramarginal), 좌측 후중심이랑(left post central), 우측 상부측두고랑(right bank of the superior temporal sulcus), 중측두이랑(right middle temporal), 전대상피질(right rostral anterior cingulate), 뇌섬엽(right insula)의 두께가 유의미하게 감소하였다(p<0.05). 그 중 평균 차이의 크기(cohen's d)가 큰 영역은 좌측 fusiform (d=0.82), pars opercularis (d=0.94), superior frontal (d=0.88), 우측 lateral orbito frontal (d=0.85), pars orbitalis (d=0.89) 로 나타났다. 또한, PANSS와 양측 대뇌 피질의 평균 두께는 약한 음의 상관관계(left hemisphere r=-0.234, right hemisphere r=-0.230)를 나타내었다. 이러한 연구의 결과는 정상인과 비교하여 기분장애 환자의 피질 두께 감소영역을 확인하였고 질환의 증상 정도와 피질 두께 변화의 관련성을 확인하는 데 도움이 될 것으로 기대된다.

• 감성과학
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• 제16권4호
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• pp.527-534
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• 2013

본 연구에서는 코히어런스 분석을 통하여 시각집중 기간 동안 시간 변화에 대한 뇌기능과 관련된 공간-주파수간 연관관계를 해석하였다. 집중관련 시각자극 실험 데이터를 통해 ${\theta}$와 ${\alpha}$ 대역에서 서로 다른 두피 위치간 위상연관변화를 확인하였다. 좌우 전두엽, 전두엽과 두정엽 간 뇌유발전위는 P100, N200지점에서 위상동조를 보였으며, 전두엽과 후두엽 간 뇌유발전위는 시각 처리 정보가 반영되는 P300지점에서 위상동조를 보였다. 고정된 길이의 창을 이용하는 단구간 푸리에 변환에 비하여 연속 웨이블릿 변환은 모 웨이블릿의 파라미터 조정을 통한 다중해상도 분석이 가능하였다. 따라서 연속 웨이블릿 변환을 이용한 코히어런스 결과가 시간변화에 대한 뇌유발전위의 공간-주파수간 연관관계의 변화를 확인하는데 유효함을 확인하였다. 비 집중 자극수행에 대해서는 위상동조 현상이 나타나지 않았다.

• The Korean Journal of Physiology
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• 제28권1호
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• pp.19-25
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• 1994

On the basis of morphological and functional studies, it is now established that there exist multiple motor representation areas in the frontal lobe of subhuman primates. Recent development of analysis on cerebral critical organization in human subjects, utilizing novel techniques of PET and MRI, provides evidence of corresponding motor areas. Each area has its unique sources of inputs from the thalamus and from other parts of the cerebral cortex. To understand functional roles of these multiple motor areas, it is necessary to study neural activity while subjects are performing a variety of motor tasks. In view of high accuracy in spatial and temporal resolution, the analysis of single cells in relation to specific aspects of motor behavior remains to be a powerful research technique. It is with this technique that a number of novel concepts on functional roles of multiple motor areas have been proposed.