• Clinical and Experimental Emergency Medicine
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• 제5권4호
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• pp.278-281
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• 2018

Central retinal artery occlusion (CRAO) is considered an ophthalmologic emergency. The prognosis of this disease is very poor. Currently, there is no generally effective therapy available to treat CRAO. Hyperbaric oxygen therapy (HBOT) can increase the volume of oxygen delivered to the ischemic retinal tissue until spontaneous or assisted reperfusion occurs. We report the case of a patient who experienced sudden visual loss due to CRAO that was treated with HBOT. The patient was an 81-year-old woman who presented with CRAO in her right eye (OD). She exhibited "hand motion" visual acuity before treatment. She underwent three sessions of HBOT at a pressure of 2.8 atmospheres absolute, performed over 3 days. After 4 days in hospital, her visual acuity improved to 0.4 (OD) for far vision and 0.5 (OD) for near vision. Her vision was stable without the supply of oxygen; therefore, she was discharged.

• Journal of Korean Neurosurgical Society
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• 제41권5호
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• pp.323-326
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• 2007

Direct carotid-cavernous fistula [CCF] is a common post-traumatic disease. However, pseudoaneurysm formation after balloon occlusion is a rare complication. The author present such a case with review of the literature. A 26-year-old man involved in a motor vehicle accident as a driver. Only mild conjunctival injection and minimal exophthalmos on the right eye were noted after trauma. However, angiography revealed a direct CCF and dissection of the proximal intracranial internal carotid artery [ICA]. After first balloon occlusion of the CCF, the patient redeveloped fistula due to early deflation of the balloon. After the second balloon occlusion, pseudoaneurysm and diplopia were developed with the change of balloon position and shape. However, visual symptom spontaneously resolved and pseudoaneurysm was also decreased within 6 months after balloon occlusion.

• 감성과학
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• 제23권1호
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• pp.17-28
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• 2020

관찰자의 조망 높이의 감소는 시각장면 내의 사물들 간 중첩의 증가를 초래해 해당 사물들의 정체 파악을 어렵게 만들 가능성이 있다. 본 연구는 이러한 가능성에 기초해 조망 높이를 달리한 시야 상에 기억이 요구되는 자극들을 제시하고 해당 자극에 대한 시각단기기억 수행을 조사했다. 실험 1에서는 관찰자의 조망 높이(고, 중, 저) 차이를 반영한 격자무늬 배경과 기억 자극을 구성해 해당 자극들의 위치와 색상을 파지하는 단기기억 과제가 실시되었다. 기억 자극의 개수 증감(3 vs. 6)을 통해 기억부담의 수준을 달리해 가면서 기억 수행을 조사한 결과, 조망 높이가 가장 낮은 경우 기억부담의 증가에 따른 기억수행의 저하가 가장 분명한 것이 관찰되었다. 실험 2에서는 선형조망을 제공하는 격자무늬 배경의 유무에 따른 기억 수행을 관찰한 결과 실험 1과 동일하게 조망 높이가 가장 낮은 경우 수행이 역시 저하되는 것이 관찰되었다. 이러한 결과는 조망 높이의 차이가 시야 상의 사물들 간 중첩 단서량의 변화를 초래하며 더 나아가 이러한 변화가 초래하는 감각적 간섭이 시각단기기억 수행에 영향을 줄 가능성을 시사한다.

• 한국산학기술학회논문지
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• 제17권8호
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• pp.369-378
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• 2016

약시아동의 시력개선을 목적으로 사용하고 있는 가림치료는 부모의 협조 하에 지속적으로 이루어져야 한다. 본 연구는 약시아동 어머니를 대상으로 가림치료 교육 프로그램을 실시하여 약시아동의 시력을 향상시키고 어머니의 양육 스트레스를 감소시키며 부모 효능감을 높이고자 실시한 비동등성 대조군 전후 실험설계이다. 본 연구는 2010년 3월 5일부터 10월 5일까지 G시 소재 일 대학병원 안과 외래에서 통원 치료하는 약시아동 어머니 60명(실험군 29명, 대조군 31명)을 대상으로 하였다. 본 프로그램은 실험군에게 총 24주 동안 가림치료 어머니를 대상으로 실시되었다(면대면 상담, 전화 상담 등). 자료수집에서 시력측정은 유아용 시력표를 이용하였으며, 양육스트레스, 부모효능감은 설문지를 이용하여 측정하였다. 수집된 자료는 SPSS PC+ 20.0을 이용하여 ${\chi}^2-test$, Fisher's exact probability test, t-test 및 Repeated Measure ANOVA로 분석하였다. 가림치료 어머니교육 프로그램에 참여한 실험군은 대조군보다 시력개선 점수가 유의하게 높았고(우측, F=40.64, p<.001, 좌측, F=10.28, p<.001), 양육 스트레스가 낮았고(F=9.85, p=.003), 부모 효능감 정도가 높게 나타났다(F=22.19, p<.001). 이상의 연구 결과 가림치료 어머니교육 프로그램은 약시아동의 시력개선과 어머니의 양육스트레스가 낮아지고, 부모효능감이 높아지는 효과가 있었음을 알 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권5호
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• pp.1711-1725
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• 2014

Multi-target tracking is the main purpose of many video surveillance applications. Recently, multi-target tracking based on the particle filter method has achieved robust results by using the data association process. However, this method requires many calculations and it is inadequate for real time applications, because the number of associations exponentially increases with the number of measurements and targets. In this paper, to reduce the computational cost of the data association process, we propose a novel multi-target tracking method that excludes particle samples in the overlapped predictive region between the target to track and marginal targets. Moreover, to resolve the occlusion problem, we define an occlusion mode with the normal dynamic mode. When the targets are occluded, the mode is switched to the occlusion mode and the samples are propagated by Gaussian noise without the sampling process of the particle filter. Experimental results demonstrate the robustness of the proposed multi-target tracking method even in occlusion.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권4호
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• pp.2094-2112
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• 2019

Focusing on the issue that the conventional Kernel Correlation Filter (KCF) algorithm has poor performance in handling scale change and obscured objects, this paper proposes an anti-occlusion and scale adaptive tracking algorithm in the basis of KCF. The average Peak-to Correlation Energy and the peak value of correlation filtering response are used as the confidence indexes to determine whether the target is obscured. In the case of non-occlusion, we modify the searching scheme of the KCF. Instead of searching for a target with a fixed sample size, we search for the target area with multiple scales and then resize it into the sample size to compare with the learnt model. The scale factor with the maximum filter response is the best target scaling and is updated as the optimal scale for the following tracking. Once occlusion is detected, the model updating and scale updating are stopped. Experiments have been conducted on the OTB benchmark video sequences for compassion with other state-of-the-art tracking methods. The results demonstrate the proposed method can effectively improve the tracking success rate and the accuracy in the cases of scale change and occlusion, and meanwhile ensure a real-time performance.

• Journal of Chest Surgery
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• 제25권3호
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• pp.330-334
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• 1992

Takayasu`s arteritis is a non-specific arteritis involving the aorta and its major branches. Because of the complexity in the feature of vessel involvement, it represents various clinical presentations according to the sites of involvement. In general, the medical and the surgical treatment of this progressive disease are known to be unsatisfactory but the surgical treatment can provide symptomatic relief and prolong life in selected cases. Recently we experienced one case of Takayasu`s arteritis involving the aortic arch and its major branches. A 45 year-old male patient admitted with the complaints of dizziness, headache, visual disturbance and coldness of upper extremities. Ascending aortogram revealed total occlusion of innominate artery and near total occlusion of left common carotid artery at the site of origin of both vessels. Under the clinical diagnosis of Takayasu`s arteritis, aorto-bicarotid-right subclavian bypass was performed. Postoperative course was uneventful and most of symptoms were relieved except mild residual visual disturbance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권2호
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• pp.871-891
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• 2019

Visual tracking is a challenging task that needs learning an effective model to handle the changes of target appearance caused by factors such as pose variation, illumination change, occlusion and motion blur. In this paper, a novel tracking algorithm based on weighted local sub-space reconstruction error is presented. First, accounting for the appearance changes in the tracking process, a generative weight calculation method based on structural reconstruction error is proposed. Furthermore, a template update scheme of occlusion-aware is introduced, in which we reconstruct a new template instead of simply exploiting the best observation for template update. The effectiveness and feasibility of the proposed algorithm are verified by comparing it with some state-of-the-art algorithms quantitatively and qualitatively.

• Journal of information and communication convergence engineering
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• 제15권3호
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• pp.193-198
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• 2017

In this study, we propose a three-dimensional (3D) visualization technique of occluded objects using integral imaging with a plenoptic camera. In previous studies, depth map estimation from elemental images was used to remove occlusion. However, the resolution of these depth maps is low. Thus, the occlusion removal accuracy is not efficient. Therefore, we use a plenoptic camera to obtain a high-resolution depth map. Hence, individual depth map for each elemental image can also be generated. Finally, we can regenerate a more accurate depth map for 3D objects with these separate depth maps, allowing us to remove the occlusion layers more efficiently. We perform optical experiments to prove our proposed technique. Moreover, we use MSE and PSNR as a performance metric to evaluate the quality of the reconstructed image. In conclusion, we enhance the visual quality of the reconstructed image after removing the occlusion layers using the plenoptic camera.

• 로봇학회논문지
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• 제17권3호
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• pp.334-338
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• 2022

In visual simultaneous localization and mapping (vSLAM), the correct recognition of a place benefits in relocalization and improved map accuracy. However, its performance is significantly affected by the environmental conditions such as variation in light, viewpoints, seasons, and presence of dynamic objects. This research addresses the problem of feature occlusion caused by interference of dynamic objects leading to the poor performance of visual place recognition algorithm. To overcome the aforementioned problem, this research analyzes the role of scene semantics in correct detection of a place in challenging environments and presents a semantics aided visual place recognition method. Semantics being invariant to viewpoint changes and dynamic environment can improve the overall performance of the place matching method. The proposed method is evaluated on the two benchmark datasets with dynamic environment and seasonal changes. Experimental results show the improved performance of the visual place recognition method for vSLAM.