• Korean Journal of Radiology
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• 제23권4호
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• pp.446-454
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• 2022

Objective: To evaluate whether hyperoxia-induced ΔR₁ (hyperO₂ΔR₁) can accurately identify histological infarction in an acute cerebral stroke model. Materials and Methods: In 18 rats, MRI parameters, including hyperO₂ΔR₁, apparent diffusion coefficient (ADC), cerebral blood flow and volume, and ¹⁸F-fluorodeoxyglucose uptake on PET were measured 2.5, 4.5, and 6.5 hours after a 60-minutes occlusion of the right middle cerebral artery. Histological examination of the brain was performed immediately following the imaging studies. MRI and PET images were co-registered with digitized histological images. The ipsilateral hemisphere was divided into histological infarct (histological cell death), non-infarct ischemic (no cell death but ADC decrease), and nonischemic (no cell death or ADC decrease) areas for comparisons of imaging parameters. The levels of hyperO₂ΔR₁ and ADC were measured voxel-wise from the infarct core to the non-ischemic region. The correlation between areas of hyperO₂ΔR₁-derived infarction and histological cell death was evaluated. Results: HyperO₂ΔR₁ increased only in the infarct area (p ≤ 0.046) compared to the other areas. ADC decreased stepwise from non-ischemic to infarct areas (p = 0.002 at all time points). The other parameters did not show consistent differences among the three areas across the three time points. HyperO₂ΔR₁ sharply declined from the core to the border of the infarct areas, whereas there was no change within the non-infarct areas. A hyperO₂ΔR₁ value of 0.04 s^-1 was considered the criterion to identify histological infarction. ADC increased gradually from the infarct core to the periphery, without a pronounced difference at the border between the infarct and non-infarct areas. Areas of hyperO₂ΔR₁ higher than 0.04 s^-1 on MRI were strongly positively correlated with histological cell death (r = 0.862; p < 0.001). Conclusion: HyperO₂ΔR₁ may be used as an accurate and early (2.5 hours after onset) indicator of histological infarction in acute stroke.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2007년도 춘계학술발표회 논문집
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• pp.273-276
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• 2007

In this study, we generated DSM(Digital Surface Model)s and orthophotos with both LIDAR data and scanned aerial photos and compared them with those generated from only the scanned photos. We checked the relief displacements of buildings appearing in the generated orthophotos, where the displacement should not be exist in a true-orthophoto. The RMSE of the relief displacement in the orthophoto generated using a LIDAR DSM is 3 m while the RMSE in the orthophotos from a DSM based on the image matching is 6.1 m. It was revealed that the orthophoto from a LIDAR DSM are closer to a true-orthophoto. But the results in the accuracy test and similarity evaluation of the generated orthophotos were contrary to former results because the roof texture of buildings were expanded to occlusion areas around the buildings. With the central area of the photo, we can generate sufficiently accurate true-orthophotos using a LIDAR DSM.

• Journal of Chest Surgery
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• 제20권1호
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• pp.187-190
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• 1987

The Saphenous vein is still the graft of choice for bypass of small calibered peripheral arteries, and many recent studies revealed that the "In Situ" technique had higher rate of long term patency than the conventional "reversed" one. A 71-year-old male who had atherosclerotic obstruction in the superficial femoral and popliteal trifurcation underwent In Situ saphenous vein arterial bypass. The saphenous vein is exposed by a long medial skin incision over the course of the vein. All branches of vein are ligated. A olive-tipped metal needle is introduced into the vein from above and everts the valves. The patient has been followed for 2 months after operation. The graft remained pulsatile and the gangrenous areas on the toe proceeded to heal. We think In situ vein bypass offers an excellent and safe method of revascularization of the arterial occlusion below the knee although it is technically demanding and the time consuming. time consuming.

• Journal of Korean Neurosurgical Society
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• 제53권3호
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• pp.180-182
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• 2013

We describe a case of intracranial carotid artery occlusion due to penetrating craniofacial injury by high velocity foreign body that was relieved by decompressive surgery. A 46-year-old man presented with a penetrating wound to his face. A piece of an electric angular grinder disc became lodged in the anterior skull base. Computed tomography revealed that the disc had penetrated the unilateral paraclinoid and suprasellar areas without flow of the intracranial carotid artery on the lesion side. The cavernous sinus was also compromised. Removal of the anterior clinoid process reopened the carotid blood flow, and the injection of glue into the cavernous sinus restored complete hemostasis during extraction of the fragment from the face. Digital subtraction angiography revealed complete recanalization of the carotid artery without any evidence of dissection. Accurate diagnosis regarding the extent of the compromised structures and urgent decompressive surgery with adequate hemostasis minimized the severity of penetrating damage in our patient.

• The Korean Journal of Physiology and Pharmacology
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• 제8권2호
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• pp.77-81
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• 2004

The loss of neurons and synaptic contacts following cerebral ischemia may lead to a synaptic plastic modification, which may contribute to the functional recovery after a brain lesion. Using synapsin I and GAP-43 as markers, we investigated the neuronal cell death and the synaptic plastic modification in the rat hippocampus of a middle cerebral artery occlusion (MCAO) model. Cresyl violet staining revealed that neuronal cell damage occurred after 2 h of MCAO, which progressed during reperfusion for 2 weeks. The immunoreactivity of synapsin I and GAP-43 was increased in the stratum lucidum in the CA3 subfield as well as in the inner and outer molecular layers of dentate gyrus in the hippocampus at reperfusion for 2 weeks. The immunoreactivity of phosphosynapsin was increased in the stratum lucidum in the CA3 subfield during reperfusion for 1 week. Our data suggest that the increase in the synapsin I and GAP-43 immunoreactivity probably mediates either the functional adaptation of the neurons through reactive synaptogenesis from the pre-existing presynaptic nerve terminals or the structural remodeling of their axonal connections in the areas with ischemic loss of target cells. Furthermore, phosphosynapsin may play some role in the synaptic plastic adaptations before or during reactive synaptogenesis after the MCAO.

• 한국산학기술학회논문지
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• 제21권10호
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• pp.77-83
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• 2020

국토를 효율적으로 관리하고 도시문제를 과학적으로 해결하기 위해 최근 스마트시티, 디지털트윈 등 3차원 공간정보 관련 기술이 급격하게 발전하고 있다. 이러한 3차원 공간정보 구축은 주로 영상정보를 이용하여 객체를 3차원 입체화하고 실감형 영상인 텍스처링 영상을 추출하여 객체벽면에 영상을 부여하는 방식으로 수행된다. 하지만 객체 주변의 다양한 요인으로 인해 텍스처링 영상에서는 필연적으로 폐색영역이 발생한다. 이에 본 연구에서는 최근 기술인 딥러닝 기술 중에서 ResNet 알고리즘을 이용하여 건물 폐색을 유발하는 가로수에 대한 데이터셋을 만들고 이에 대한 해결방안을 제시하고자 한다. 연구결과 ResNet 알고리즘의 공간정보 적용 가능성을 판단하고 이를 적용한 레이블링 생성 SW 개발하여 실제 가로수를 대상으로 데이터셋을 구축하였다. 구축된 데이터셋을 텍스처링 영상에 적용하여 정확도와 재현율로 검출능력을 분석하였다. 분석결과를 위해 딥러닝 분야에서 많이 사용되고 있는 정밀도와 재현율을 이용한 F값을 적용하였으며 가로수 단일 객체가 포함된 건물의 측면부 영상과 경사 영상에 대해서는 높은 F값을 도출하여 우수한 성과를 확인하였으나, 같은 해상도를 가진 건물 전면부 영상에서는 그림자 등의 요인으로 F값이 낮음을 확인하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권4호
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• pp.221-228
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• 2009

The purpose of the study was to investigate the characteristics of the pronunciation of Korean vowels in patients with class III malocclusion. 11 adult male patients with class III malocclusion(mean ages 22.3 years) and four adult males with normal occlusion(mean ages 26.5 years) were selected for the analysis of eight Korean monophthongs /ㅣ, ㅔ, ㅐ, ㅏ, ㅓ, ㅗ, ㅡ, ㅜ/. The values and relationships of F1, F2 and F3 were derived from the stable section of target vowel in each sentence, and the analysis using formant plots and vowel triangles' distance and area was conducted to find the features of two groups' vowel distributions. Consequently, it was identified that the pronunciation of males patients with class III malocclusion showed high values of F1 in the low vowels, high values of F2 in the back vowels, and remarkably low position of /ㅏ/. The vowel triangle suggested that the triangle areas of male patients with class III malocclusion were shown wider vertically and narrower horizontally than those of males with normal occlusion. These characteristics could reflect the structural features of class III malocclusion such as the prognathic mandible, low tongue position, and advancement of back position of the tongue.

• 방송공학회논문지
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• 제10권3호
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• pp.286-296
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• 2005

본 논문은 3차원 실감 영상 텔레비전을 위한 스테레오 기반 영상 압축 및 전송장치에 관한 것이다. 본 논문에서는 입력되는 두 개의 스테레오 영상에서 영상처리 기반 disparity map을 추출하고, 추출된 disparity map과 두 개의 스테레오 영상 중에 한 개의 영상만을 전송하거나 저장하는 방식이다 기존의 방식은 occlusion 지역에서 대응점을 결정할 수 없는 문제로 인하여 3차원 영상 복원 시 데이터가 손실되는 단점을 가지고 있다. 본 논문에서는 블록기반 에러 은닉 기법과 루프 필터를 사용한 복원 영상 보정 알고리즘을 제안하여 3차원 영상 복원 시 생길 수 있는 오차를 최소화하였다. 제안한 알고리즘의 효율성을 보이기 위하여 다양한 실제 영상을 사용하였으며 영상 복원 정확성의 객관적 판단기준을 통하여 제안한 알고리즘이 스테레오 영상을 표현하는데 효과적인 방법임을 증명하였다.

• 구강회복응용과학지
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• 제18권4호
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• pp.235-249
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• 2002

This study was accompolished to analyze and compare the number and area of the occlusal contact points in healthy volunteers and athletes with normal occlusion. Before the study, 89 athletes(sports career:8.6 years, average age 20) at Kyung Hee University were selected, and survey was accomplished for athlete's recognition about sports dentistry. For this study, 15 athletes(13 amles and 2 females with average age 20) and 21 healthy volunteers(14 mles and 7 females with average age 20.09) at Kyung Hee University were selected. The visual display acquired by scanning of occlusal record in maximal intercuspation was converted into 16 gray value image. Then, using computer program(J & Lee Occlusal Analyser), the pixel which was in definite range of the gray value was recognized, and the numbers of recognized pixel were calculated to area. The results were as follows : (1) On the survey about sports dentistry, 28% of 89 athletes didn't agree that human occlusion may be important, and 30% didn't have any idea of the influence of human occlusion during their sports activities. (2) The average numbers of total occlusal contact points were 31.05 in control group, and 34.67 in athlete group. The average area of total occlusal contacts was $100.25mm^2$ in control group, and $127.78mm^2$ in athlete group. (3) In control group, the average numbers of occlusal contact points were revealed in order as follows; the first molar(8.48), the second molar(8.24), the second premolar(4.71), the lateral incisor(2.90), the first premor(2.43), the central incisor(2.19), and the canine(2.1). The least average in canine(2.1) was similar to the average(2.19) in central incisor and (2.09) in lateral incisor. In athlete group, the average numbers of occlusal contact points were revealed in order as follows; the first molar(8.87), the second molar(8.47), the second premolar(5.60), the canine(3.80), the lateral incisor(3.33), the first premolar(2.67), and the central incisor(1.93). (4) In control group, the average areas of occlusal contact surface were revealed in order as follows; the first molar($39.47mm^3$), the second molar($37.54mm^3$), the second premolar($9.54mm^3$) the first premolar($6.18mm^3$), canine($3.49mm^3$), the central incisor($2.76mm^3$), and the lateral incisor($1.28mm^3$). In athlete group, the average areas of occlusal contact surface were revealed in order as follows; the first molar($44.11mm^3$), the second molar($40.69mm^3$), the second premolar($16.50mm^3$), the first premolar($9.39mm^3$), the canine($5.08mm^3$), the lateral incisor($3.7mm^3$), and the central incisor($2.25mm^3$). (5). With aging in both control and athlete group, there was a decreasing tendancy in average number of occlusal contact point, and was an increasing tendancy in average area of occlusal contact surface. In comparison at each age, both the numbers and area of occlusal contact were greater in athlete group than in control group. It was not significant in the numbers of occlusal contact points beween athlete and control group(p>0.1), but significant in the area of occlusal contact surface(p<0.05). (6) In comparision as to the kind of sports(Gymnastics:2, Rugby:3, Soccor:5, Ice hocky:5), the numbers of occlusal contact points were the most in ice hocky, and the area of occlusal contact surface was the greatest in gymnastics. With increasing a career in athlete group, there was a decreasing tendancy in average numbers of occlusal contact points, and was an increasing tendancy in average area of occlusal contact surface.

• 대한치과교정학회지
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• 제26권4호
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• pp.373-387
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• 1996

본 연구는 비인두와 adenoid의 성장발육 양상을 조사하여 부정교합자의 진단에 있어 비호흡 기능 평가시 유용한 기준을 얻기 위하여 시행되었다. 남자 19명, 여자 14명, 총 33명의 정상 교합자를 대상으로 8.5세부터 18.5세까지 촬영된 10년간의 누년적 측모 두부 X선 규격사진을 연구 자료로 비인두와 adenoid 부위의 거리와 면적 및 상대적 기도 비율을 계측 분석하여 다음과 같은 결론을 얻었다. 1. 각 연령(8.5세-18.5세)에서 남녀별 각 계측항목의 평균과 표준 편차를 얻었다. 2. 비인두의 height와 depth는 남자에서 14.5세까지, 여자에서 12.5세까지 성장하였다.(p<0.05). 3. 비기도의 상대적 면적은 8.5세에 최소치를 나타내었고 남자는 10.5세부터 12.5세 사이에, 여자는 12.5세부터 14.5세 사이에 유의한 증가를 나타내었다(p<0.05). 4. 비기도의 상대적 면적과 비기도 관련 계측항목 간의 상관분석에서 Ad2-PNS, Ad2-PNS/Ho'-PNS 및 Upper pharynx가 남녀 모두 전 연령구간에서 비기도의 상대적 면적과 상관성이 있었다 (p<0.01).