• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.1129-1136
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• 2021

A pan-tilt-zoom (PTZ) camera-based monitoring system for efficient monitoring in the engine room of a vessel was designed. A number of places exist where traditional analog instruments are still used in vessel engine rooms, and blind spots closely related to safety exist, for which flooding or fire is a concern. A camera-based monitoring system that guarantees a wide range at a relatively fast cycle for these monitoring points can be an effective alternative to enhance the safety of a vessel. Therefore, a multiview monitoring system is proposed in which the functions of the existing PTZ camera are further strengthened using a software. The monitoring system comprises four modules: camera control, location registration, traversal control, and multiview image reconstruction. The effectiveness of the method was evaluated through a series of experiments in an engine room environment.

• The KIPS Transactions:PartA
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• v.9A no.4
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• pp.581-588
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• 2002

In implementing interactive multimedia systems, real-time visualization plays an important role. This paper presents efficient data structures and algorithms for real-time terrain navigation. Terrain data set is usually too huge to display as is. Therefore LOD (levels of detail) methods and view frustum culling are essential tools. This paper describes in detail compact hierarchical data structures, fast view frustum culling, and efficient LOD construction/rendering algorithms. Unlike previous works, we use a precise screen-space error metric for vertex removal and a strict error threshold allowing sub-pixel -sized errors only. Nevertheless, we can achieve 22 fps on average in a PC platform. The methods presented in this paper also satisfy almost all of the requirements for interactive real-time terrain Visualization.

• Journal of Digital Contents Society
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• v.15 no.1
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• pp.39-43
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• 2014

This paper suggested a whiteboard for multimedia collaboration work. We implemented the whiteboard so that the users participated in collaborative work may refer shared media objects as the same view to others. In this paper, we discuss a method for increasing reliability of media data through whiteboard. This paper explains a performance analysis of a media data system running on distributed multimedia environment using the rule-based DEVS modeling and simulation techniques.

• The Journal of the Acoustical Society of Korea
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• v.38 no.2
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• pp.161-167
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• 2019

In this paper, the performance verification of an around-view sonar and an excavation depth measuring sonar applicable to track-based ROVs (Remotely Operated underwater Vehicles) for heavy duty work is studied. For the performance verification, an experiment is carried out in a water tank and at sea by attaching the around-view sonar and the excavation depth measuring sonar for a heavy work ROV. In the case of the around-view sonar, image sonars are mounted on ROV in four directions (front, back, left and right) and in the case of the excavation depth measuring sonar, the same kind of MBES (Multi Beam Echo Sounder) is mounted on the front of the ROV. The result of an operation test of the ROV equipped with these sonars shows that the sonar systems are rarely affected by high turbidity due to sedimentation during the operation. In the case of the around-view sonar, it is possible to see rock formation, gravel and sandbank 30 m ahead of the ROV. It is confirmed that the excavation depth can be measured after the ROV has performed the excavation. This experiment demonstrates that the ROV can improve the efficiency of the work by utilizing the around-view sonar and the excavation depth measuring sonar.

• Journal of the Korea Society of Computer and Information
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• v.16 no.12
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• pp.93-102
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• 2011

This paper presents a walking guidance system for blind pedestrians in an outdoor environment using just one single camera. Unlike many existing travel-aid systems that rely on stereo-vision, the proposed system aims to get necessary information of the road environment by using just single camera fixed at the belly of the user. To achieve this goal, a top-view image of the road is used, on which obstacles are detected by first extracting local extreme points and then verified by the polar edge histogram. Meanwhile, user motion is estimated by using optical flow in an area close to the user. Based on these information extracted from image domain, an audio message generation scheme is proposed to deliver guidance instructions via synthetic voice to the blind user. Experiments with several sidewalk video-clips show that the proposed walking guidance system is able to provide useful guidance instructions under certain sidewalk environments.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10a
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• pp.399-403
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• 2006

실시간 운영체제(Real Time System)를 탑재한 내장형 시스템(Embedded System)은 수십 년 전부터 다양한 용도로 개발되어 왔다. 그래픽 장치들이 미비했던 초기의 내장형 시스템에서는 사용자 인터페이스가 단순하게 구현되었으나, 기술의 발달로 인하여 사용자가 쉽게 이용할 수 있게 GUI(Graphic User Interface)가 적용될 필요가 있다. 멀티미디어 기기에서 요구되는 포토 뷰, MP3P, 동영상과 같은 기능들을 만족 시키고, 또한 내장형 시스템의 특성상 GUI 가 경량이어야 한다. 본 논문에서는 실시간 운영체제인 UbiFOS$^{TM}$ 에 멀티미디어 기기를 위한 UbiFOS_GUI 를 설계 및 구현하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.660-662
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• 2023

3차원 포인트 클라우드의 의미적 분할은 환경을 구성하는 물체 단위로 포인트 클라우드를 분할하는 작업으로서, 환경의 3차원적 구성을 이해하고 환경과 상호작용에 필수적인 시각 지능을 요구한다. 본 논문에서는 포인트 클라우드에서 추출하는 3차원 기하학적 특징과 함께 멀티-뷰 영상에서 추출하는 2차원 시각적 특징들도 활용하는 새로운 3차원 포인트 클라우드 의미적 분할 모델 MFNet을 제안한다. 제안 모델은 서로 이질적인 2차원 시각적 특징과 3차원 기하학적 특징의 효과적인 융합을 위해, 새로운 중기 융합 전략과 멀티-모달 교차 주의집중을 이용한다. 본 논문에서는 ScanNetV2 벤치마크 데이터 집합을 이용한 다양한 실험들을 통해, 제안 모델 MFNet의 우수성을 입증한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.175-178
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• 2002

본 논문에서는 일반책에서의 정적 컨텐츠 요소와 오디오나 동영상 등의 멀티미디어 요소를 디지털 형태의 정보로 가공 및 저장하여 전자북을 편집할 수 있는 전자 출판 시스템을 설계한다. 기존의 전자북들은 멀티미디어 요소들을 보기 위한 별도의 전용 뷰어 설치가 요구되며, 서로 다른 포맷이나 다양한 프로그램들로 제작되어 문서의 통합 저장 및 관리가 어려운 실정이다. 본 논문에서 설계한 시스템은 별도의 전용 뷰어 대신 익스플로어와 같은 일반적인 뭔 브라우저를 이용하는 웹 뷰어를 지원하고, XML을 사용하여 보다 효율적으로 정보의 통합 관리 및 저장을 지원함으로써 다양한 컨텐츠 정보의 고수준의 재사용성을 제공한다. 또한, 웹상에서의 멀티미디어 요소들의 표현 시 요구되는 동기화 처리 기술을 위하여 SMIL을 이용함으로써 보다 다양한 멀티미디어 컨텐츠 및 멀티미디어 요소들의 시간적, 이벤트 발생적 동기화를 지원하여 정보 전달의 이해도를 놀일 수 있도록 한다. 설계 시스템은 웹 상에서 전자북을 보기위한 웹 뷰어, 전자북 출판 시 텍스트와 멀티미디어 요소를 표현하는 XML과 SMIL문서를 각각 자동적으로 생성하는 XMLnSMIL 에디터, 생성된 각 문서들을 데이터베이스에 저장하기 위한 XMLnSMIL2DB 저장기, 데이터베이스 내의 데이터들로 부터 XML과 SMIL문서를 자동으로 생성하는 DB2XMLnSMIL 생성기 등으로 구성된다.

• Journal of Digital Contents Society
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• v.8 no.2
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• pp.113-119
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• 2007

Recently, multimedia applications using internet are increasing by emergency of UCC. The retrieval of photo, video, audio is a main issue to increase utility of access and efficiency of access time. But the exist multimedia applications do not provide the practical ranking system. They provide only simple ranking system using metric. This paper provides "PhotoToc", the user favor-based multimedia ranking system, that can provide differenced view to users. The proposed system has a to retrieve the user centered results.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.12
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• pp.505-518
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• 2023

3D point cloud semantic segmentation is a computer vision task that involves dividing the point cloud into different objects and regions by predicting the class label of each point. Existing 3D semantic segmentation models have some limitations in performing sufficient fusion of multi-modal features while ensuring both characteristics of 2D visual features extracted from RGB images and 3D geometric features extracted from point cloud. Therefore, in this paper, we propose MMCA-Net, a novel 3D semantic segmentation model using 2D-3D multi-modal features. The proposed model effectively fuses two heterogeneous 2D visual features and 3D geometric features by using an intermediate fusion strategy and a multi-modal cross attention-based fusion operation. Also, the proposed model extracts context-rich 3D geometric features from input point cloud consisting of irregularly distributed points by adopting PTv2 as 3D geometric encoder. In this paper, we conducted both quantitative and qualitative experiments with the benchmark dataset, ScanNetv2 in order to analyze the performance of the proposed model. In terms of the metric mIoU, the proposed model showed a 9.2% performance improvement over the PTv2 model using only 3D geometric features, and a 12.12% performance improvement over the MVPNet model using 2D-3D multi-modal features. As a result, we proved the effectiveness and usefulness of the proposed model.