• Journal of Chest Surgery
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• 제12권1호
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• pp.61-66
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• 1979

This is a report of a case of tuberculous esophageal perforation, which was surgically treated.. The patient was 32-year-old Korean female patient, who complained swallowing difficulty for` 4 weeks duration. Esophagogram was shown irregular filling defects in the upper one third of esophagus, about 4 cm in length. It was noticed that a small amount of contrast media was leaked out from the involved area of esophagus into the right mediastinum. It was highly suggested that abscess formation was due to perforation of esophageal cancer. Esophagoscopy revealed no definitive evidence of perforation of esophagus, but punch biopsy specimen of esophageal mucosa was shown acute and chronic inflammatory changes. Operation was performed under impression of esophageal cancer. In the right-sided upper mediastinum, a walnut-sized abscess cavity which was connected with esophagus through a fistulous tract was noted. A portion of cavity submitted for frozen section was shown tuberculous inflammation. The abscess cavity, fistula tract, and involved esophageal wall were removed. The perforated esophagus was closed layer by layer. The tuberculous changes were confirmed by histopathologic examination postoperatively. The postoperative course was uneventful.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2011년도 하계학술대회
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• pp.517-519
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• 2011

본 논문에서는 DIBR(Depth image-based rendering)을 통해 생성되는 3D 영상의 홀을 고품질로 채우는 방법을 제안한다. 이를 위해, 생성된 영상의 깊이도를 고려한 희소성(Sparsity) 기반의 인페인팅 알고리즘을 홀 채우기에 적용하였다. 본 논문에서 제안하는 알고리즘은 홀 주변의 전경 텍스쳐를 제외한 배경 텍스쳐 정보만을 이용하기 때문에, 홀 채우기 시 전경 텍스쳐와 배경 텍스쳐가 혼합되는 문제점이 발생하지 않는다. 또한 희소성 기반의 인페인팅을 이용하기 때문에 에지 정보를 활용한 고품질의 홀 채우기가 가능하다. 본 논문에서 제안하는 알고리즘과 기존의 홀 채우기 알고리즘과의 주관적 화질 비교 결과, 본 논문에서 제안하는 알고리즘의 우수성을 확인할 수 있었다.

• Computers and Concrete
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• 제4권4호
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• pp.273-284
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• 2007

The paper considers a theoretical model for the study of the process of transfer of sulfate ions in saturated porous media - mineral composites. In its turn, the model treats diffusion of sulfate ions into cement based composites, accounting for simultaneous effects such as filling of micro-capillaries with ions and chemical products and liquid push out of them. The proposed numerical algorithm enables one to account for those simultaneous effects, as well as to model the diffusive behavior of separate sections of the considered volume, such as inert fillers. The cases studied illustrate the capabilities of the proposed model and those of the algorithm developed to study diffusion, considering the specimen complex configuration. Computations show that the theoretical assumptions enable one to qualitatively estimate the experimental evidence and the capabilities of the studied composite. The results found can be used to both assess the sulfate corrosion in saturated systems and predict and estimate damage of structures built of cement-based mineral composites.

• Journal of Multimedia Information System
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• 제4권1호
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• pp.19-26
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• 2017

The compression of video for both full HD and UHD requires the inclusion of extra vertical lines to every video frame, named as the DTV essential hidden area (DEHA), for the effective functioning of the MPEG-2/4/H encoder, stream, and decoder. However, while the encoding/decoding process is dependent on the DEHA, the DEHA is conventionally viewed as a redundancy in terms of channel utilization or storage efficiency. This paper proposes a block mode DEHA method to more effectively utilize the DEHA. Partitioning video block images and then evenly filling the representative DEHA macroblocks with the average DC coefficient of the active video macroblock can minimize the amount of DEHA data entering the compressed video stream. Theoretically, this process results in smaller DEHA data entering the video stream. Experimental testing of the proposed block mode DEHA method revealed a slight improvement in the quality of the active video. Outside of this technological improvement to video quality, the attractiveness of the proposed DEHA method is also heightened by the ease that it can be implemented with existing video encoders.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 추계학술발표회
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• pp.231-234
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• 2001

When constructing subsurface structures and/or wells, the precise estimates of hydraulic parameters must be obtained for operating safety and/or for developing necessary quantity of groundwater. Hydraulic conductivity is mainly subjected to the characteristics of fracture network in the fractured media such as fracture orientation and angle, fracture aperture and frequency, fracture length, interconnectivity of fractures, and filling material, feature of fracture plane. In this study we conducted water injection test at afferent depths on six boreholes drilled in granite of Mt. Geumjeong. hydraulic conductivity was calculated using Moye and Hvorslev methods. The relation between hydraulic conductivity and fracture frequency data obtained from acoustic televiewer and core log were analyzed. The result shows that the correlation between the hydraulic conductivity and the fracture frequency data obtained from acoustic televiewer is better than that with the core log.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2017년도 추계학술대회
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• pp.133-135
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• 2017

본 논문에서는 스테레오 영상을 이용하여 외삽 시점 영상 생성 시 발생하는 홀을 채우는 방법을 제안한다. 스테레오 영상에 3D 워핑을 이용하여 다수의 시점을 생성할 수 있다. 하지만 이 방법은 보이지 않는 시점에서의 영역을 완벽히 복원할 수 없기 때문에 필연적으로 홀이 발생한다. 홀을 채우기 위해 먼저 홀 영역의 경계를 Random Walks 알고리즘을 이용하여 전경과 배경으로 구분한다. 그리고 홀을 배경 성분에 해당하는 영역만을 이용하여 채우게 된다. 홀 채움 과정에서는 패치 내의 홀의 비율과 컬러와 깊이 영상의 텍스처에 대한 복잡도를 정의하고 패치 별로 우선순위를 계산하여 높은 순위의 패치로 홀을 채우게 된다. 실험 결과 제안하는 기법이 홀을 효과적으로 채우는 것을 확인하였다.

• Computers and Concrete
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• 제4권2호
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• pp.157-166
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• 2007

The paper considers a theoretical model to study sulfate ion diffusion in saturated porous media - cement based mineral composites, accounting for simultaneous effects, such as filling micro-capillaries (pores) with ions and chemical products and liquid push out of them. Pore volume change and its effect on the distribution of ion concentration within the specimen are investigated. Relations for the distribution of the capillary relative radius and volume within the composite under consideration are found. The numerical algorithm used is further completed to consider capillary size change and the effects accompanying sulfate ion diffusion. Ion distribution within the cross section and volume of specimens fabricated from mineral composites is numerically studied, accounting for the change of material capillary size and volume. Characteristic cases of 2D and 3D diffusion are analyzed. The results found can be used to both assess the sulfate corrosion in saturated systems and predict changes occurring in the pore structure of the composite as a result of sulfate ion diffusion.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2012년도 하계학술대회
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• pp.127-130
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• 2012

본 논문에서는 자유시점 또는 오토스테레오스코픽 비디오나 홀로그래픽 비디오 서비스 들을 목표로 가상시점 영상을 빠르게 생성하는 방법을 제안한다. 이 방법에서 좌/우 깊이영상이 주어졌다고 가정하고, 두 깊이 영상을 이용하여 깊이 값과 변위를 계산 한 후 깊이 당 변위증분을 계산하여 사용한다. 계산된 깊이 값 당 변위증분과 해당 픽셀의 깊이정보를 이용하여 텍스쳐 이미지를 원하는 가상 시점으로 이동시킨다. 좌영상과 우영상을 원하는 가상시점으로 각각 생성한 후, 잡음과 disocclusion을 효과적으로 제거하기 위하여 두 영상을 결합한다. 그 다음 남은 홀을 효과적인 hole-filling으로 제거하여 가상 시점 영상을 생성한다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2015년도 추계학술대회
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• pp.169-172
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• 2015

영상회의 장치에서 눈맞춤 영상을 생성하기 위해 어파인 변환(affine transformation)을 이용하면 반올림 오차(round-off error) 때문에 홀이 발생한다. 이러한 홀을 채우려면 홀 영역을 가리키는 홀 채움 마스크가 필요하다. 홀 채움은 보통 홀 채움 마스크를 참조하여 홀이 아닌 이웃 화소값들을 기반으로 손상된 영상을 복원하는 작업이다. 따라서 홀 영역을 정확히 검출하고 적당한 개수의 이웃 화소값을 참조해야 자연스러운 홀 채움 영상을 생성할 수 있다. 한편, 눈맞춤 영상을 생성할 때 얼굴 특징점을 이용해 얼굴 변환 마스크를 만들고, 얼굴 변환 마스크에만 어파인 변환을 수행한다. 이 논문에서는 얼굴 특징점에도 어파인 변환을 수행하고 수정된 얼굴 변환 마스크를 획득하여 정확한 홀 채움 마스크를 구한다. 또한, 홀 채움 마스크에서 레이블링을 수행하여 큰 홀 영역을 제거한다. 마지막으로, 어파인 변환을 수행할 때 기존 영상의 좌표값을 이용하여 자연스러운 홀 채움 영상을 생성한다. 제안하는 방법으로 홀 채움을 수행한 결과, 연속적인 눈맞춤 동영상에서 이웃값들을 참조하여 홀 채움을 수행한 영상보다 자연스러움을 확인했다.

• Journal of Multimedia Information System
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• 제9권1호
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• pp.43-50
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• 2022

As the discourse on Anthropocene grows, this exploratory research investigates the interrelationship and interconnectivity between humanity and technology by analyzing a sound art installation created by the author. Crying Sea is a sound installation that uses plastic wastes collected from the shore to create symbolic narratives and artistic experience connecting humans, objects, and nature through interactive digital technology. In this installation, the audiences are guided to walk over the wastes, and the sounds created by the footsteps are recorded in real-time, which then are distorted and amplified into disturbing sounds through speakers filling up the room. In analyzing this artwork, three theories from technological, philosophical, and ecological backgrounds were used; specifically, Bernard Stiegler's pharmakon theory, Dona Haraway's cyborg manifesto, and Timothy Morton's dark ecology theory. A common factor revealed from all three theories by analyzing the Crying Sea is that humans, technologies, and all other entities within nature are interconnected and resonated. The awareness of this recursive relationship allows us to consider sustainable balancing.