• Korean Journal of Radiology
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• 제22권4호
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• pp.568-576
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• 2021

Arteriovenous malformations (AVMs) are direct communications between primitive reticular networks of dysplastic vessels that have failed to mature into capillary vessels. Based on angiographic findings, peripheral AVMs can be classified into six types: type I, type IIa, type IIb, type IIc, type IIIa, and type IIIb. Treatment strategies vary with the types. Type I is treated by embolizing the fistula between the artery and the vein with coils. Type II (IIa, IIb, and IIc) AVM is treated as follows: first, reduce the blood flow velocity in the venous segment of the AVM with coils; second, perform ethanol embolotherapy of the residual shunts. Type IIIa is treated by transarterial catheterization of the feeding arteries and injection of diluted ethanol. Type IIIb is treated by transarterial or direct puncture approaches. A high concentration of ethanol is injected through the transarterial catheter or direct puncture needle. When the fistula is large, coil insertion is required to reduce the amount of ethanol. Type I and type II AVMs showed the best clinical results; type IIIb showed a satisfactory response rate. However, type IIIa showed the poorest response rate, either alone or in combination with other types. Clinical success can be achieved by using different treatment strategies for different angiographic AVM types.

• 한국생산제조학회지
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• 제7권1호
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• pp.9-21
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• 1998

This paper a new solution approach to moving obstacle avoidance problem of a mobile robot. A new concept avoidability measure (AVM) is defined to describe the state of a pair of a robot and an obstacle regarding the collision between them. As an AVM, virtual distance function (VDF), is derived as a function of the distance from the obstacle to the robot and outward speed of the obstacle relative to the robot. By keeping the virtual distance above some positive limit value, the robot avoids the obstacle. In terms of the VDF ,an artificial potential field is constructed to repel the robot away from the obstacle and to attract the robot toward a goal location. At every sampling time, the artificial potential field is updated and the force driving the robot is derived from the gradient of the artificial potential field. The suggested algorithm drives the robot to avoid moving obstacles in real time. Since the algorithm considers the mobility of the obstacle as well as the distance, it is effective for moving obstacle avoidance. Some simulation studies show the effectiveness of the proposed approach.

• Journal of Korean Neurosurgical Society
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• 제42권1호
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• pp.49-52
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• 2007

The authors report a unique case of unilateral Moyamoya disease with a rare combination of arteriovenous malformation (AVM) who presented with intracerebral hemorrhage (ICH). A 50-year-old man suffered from sudden onset of mental deterioration and right hemiparesis. Brain computed tomography (CT) showed intracerebral hemorrhage on left thalamus. Brain CT angiography and cerebral digital subtraction angiography (DSA) revealed AVM combined with unilateral moyamoya disease involving left middle cerebral artery (MCA) and choroid plexus in left lateral ventricle. Intraventricular hemorrhage and hydrocephalus were managed conservatively. A rare case of unilateral Moyamoya disease accompanied by a cerebral arteriovenous malformation is described and discussed with review of pertinent literature.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1998년도 춘계학술대회 논문집
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• pp.88-93
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• 1998

This paper presents a new solution approach to moving obstacle avoidance problem for a mobile robot. A new concept avoidability measure(AVM) is defined to describe the state of a pair of a robot and an obstacle regarding the collision between them. As an AVM, virtual distance function(VDF) is derived as a function of the distance from the obstacle to the robot and outward speed of the obstacle relative to the robot. By keeping the virtual distance above some positive limit value, the robot avoids the obstacle. In terns of the VDF, an artificial potential field is constructed to repel the robot away from the obstacle and to attract the robot toward a goal location. At every sampling time, the artificial potential field is updated and the force driving the robot is derived form the gradient of the artificial potential field. The suggested algorithm drives the robot to avoid moving obstacles in real time. Since the algorithm considers the mobility of the obstacle as well as the distance, it is effective for moving obstacle avoidance. Some simulation studies show the effectiveness of the proposed approach.

• Journal of Chest Surgery
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• 제47권1호
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• pp.66-70
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• 2014

A 10-year-old boy with arteriovenous malformation (AVM) of the right lower limb was scheduled for an amputation of the affected limb. Limb amputation was necessary because of the ineffectiveness of previous sclerotherapy and the rapid progression of AVM causing pain and heart failure. Right hip disarticulation was considered the best option to improve his quality of life. To prevent congestive heart failure and uncontrollable hemorrhage during surgery, the disarticulation was done under a partial cardiopulmonary bypass. The patient underwent surgery successfully without complications.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.477-480
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• 2013

어라운드 뷰 시스템은 승용차의 앞뒤와 좌우 사이드 미러 하단에 1개씩 4개의 카메라를 이용해, 내비게이션 화면에 마치 차를 위에서 찍은 듯한 화면을 만들어 주는 기술이다. 최근 차량의 증가로 인해 사용자의 편의 및 안전에 대한 요구와 의존도가 증가함에 따라 운전자를 위한 보조 시스템이 구축되고 있다. 현재 운전자를 위한 보조 시스템으로 AVM(Around View Monitoring)기술이 개발되었다. 본 논문에서는 현재 시중에 제공되고 있는 다양한 어라운드 뷰 시스템들마다 인터페이스가 다르기 때문에 이를 어떻게 적용되었는지를 각 시스템들마다 비교분석하여 장점들을 알아보고, 이를 통해 각 인터페이스들의 장점들을 종합하여 효율적인 인터페이스를 제시하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 추계학술대회
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• pp.503-506
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• 2011

최근 다양하게 등장하고 있는 운전자를 위한 보조 장치 중 운전자의 주차를 위해 사용되는 장치들 중 하나인 차량용 카메라는 주로 차량 후방의 번호판 위에 주로 위치하여 운전자의 주차에 도움을 주는 역할에 사용이 되고 있다. 최근에는 이러한 카메라를 이용하여 전 후방 및 좌 우측을 모두 보여주기 위한 AVM(Around View Monitor) 시스템이 개발되었다. 그러나 다수의 카메라를 사용하는 AVM시스템에서 운전자에게 통합된 영상을 제공하기 위해서는 카메라의 방사왜곡보정과 호모그래피(Homography) 알고리즘을 통해 정합하는 과정이 필요하다. 본 논문에서는 호모그래피 과정에서 결과 영상의 품질을 개선하기 위한 방법을 제안한다. 또한, 제안하는 방법을 구현하여 기존의 8DOF(Degree of Freedom)을 사용한 방법과 결과 영상의 품질을 비교함으로써 개선된 영상을 제공할 수 있음을 제시한다.

• Journal of Korean Neurosurgical Society
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• 제30권sup2호
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• pp.368-372
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• 2001

Arteriovenous malformations of the face and scalp are uncommon. We report a patient with facial AVM feeding from external carotid artery. This 26-year old man presented with an arteriovenous malformation involving left forehead. The patient first noted a coin-sized lesion on the site 20 years previously after blunt trauma which progressively enlarged. Surgical resection of AVM was performed after ligation of feeding artery.

• Journal of Korean Neurosurgical Society
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• 제38권6호
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• pp.471-474
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• 2005

Pure sylvian fissure arteriovenous malformations[AVMs] are vascular malformations confined to the sylvian fissure without parenchymal involvement. Surgical removal is regarded as difficult because the nidus is located just lateral to important structures such as the basal ganglia and the internal capsule. Because most feeding arteries to the nidus are branches of the middle cerebral artery[MCA], differentiation between these feeders from en passant and normal vessels is of great importance in order to reduce morbidity and mortality from surgical intervention. We report a case of pure sylvian fissure AVM who presented with an intra-temporal lobe hematoma that was located around venous aneurysms distant from the nidus. The clinical characteristics of this AVM and the surgical methods employed to avoid complications are discussed.

• 대한두경부종양학회지
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• 제34권2호
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• pp.85-87
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• 2018

The arteriovenous malformation (AVM) is an anomaly of capillary development that results from direct connection between branches of artery and vein without intervening capillary bed. The neurogenic tumors have a tendency to various types of degeneration. Recently, we experienced a 73-year old man with a mass in left supraclavicular area. The intraoperative findings showed severe adhesions with cervical plexus, like a neurogenic tumor. Finally, the mass was revealed as AVM. We report a unique disease pattern with a literature review.