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무선 네트워크에서 계층기반 RED 알고리즘을 이용한 스케일러블 비디오 스트리밍
하호진(Hojin Ha) 한국정보기술학회 2022 한국정보기술학회논문지 Vol.20 No.1
Recently, as the demand for video content increases, various compression and transmission techniques for efficiently transmitting video have been studied. In this paper, we propose a layer-based Random early detection (RED) unequal loss protection algorithm for scalable video transmission in wireless networks. The proposed algorithm is transmits packets using ULP algorithm that minimizes video quality degradation due to packet loss by using the network load and layer-based the amount of error propagation. The error propagation model for measuring the layer-based error propagation amount is calculated using the compression structure of the scalable video. In the experiment, the proposed algorithm showed high Peak signal-to-noise ratio (PSNR) in various network environments compared to the existing ULP algorithm.
압력센서와 영상처리 보간기법을 이용한 앉은 자세의 교정 알고리즘 설계
하호진(Hojin Ha),이창동(Changdong Lee) 한국정보기술학회 2016 한국정보기술학회논문지 Vol.14 No.1
Modern men have lived in a chair more than 12 hours a day. In a sedentary lifestyle for a long time, an improper posture have an critical effect on a body health. In this paper, we propose a software(SW) for guidance of sitting posture correction with two features. First, the proposed SW provides the image related to the distribution of pressure sensors for notifying the current status of sitting posture to users. To improve the image quality, we utilizes the proper combination of bilinear and 3D cubic convolution interpolation method. Second, we analyze the status of current sitting posture using measured values of pressure sensors and divide the current sitting posture into 3 improper sitting posture groups. According to the improper postures, suitable exercises are recommended for posture correction. Implementation results show that the proposed SW is effective for correcting posture of sitting.
하호진(Hojin Ha),서현곤(HyunGon Seo) 한국경영과학회 2014 經營 科學 Vol.31 No.4
Recently, various types of information and communication technology (ICT) such as cloud computing, big data, and virtual reality have been progressed in the world. Also, it is expected that there are many domestic and foreign visitors in Gangwon-do due to the Pyeongchang winter olympic games in 2018. In this environment, it is necessary to improve the competitiveness of Gangwon-do in winter sports areas exploiting both existing IT infrastructure and application technologies. In this paper, for sustainable development of Gangwon-do winter sports IT industry after the Olympics, we propose efficient implementation methods of 3 winter sports IT convergence services and Gangwon-do ICT activation strategy. The proposed 3 winter sports IT service areas are as follows. 1) Realistic winter sports IT service, 2) Winter sports medical IT service 3) Winter sports record analysis IT service.
Intra Coded Pictures(ICP)을 이용한 360 영상의 뷰포트 기반 적응적 스트리밍
하호진(Hojin Ha) 한국정보기술학회 2020 한국정보기술학회논문지 Vol.18 No.11
Recently, as the demand for 360-degree video content grows, various compression and transmission techniques for efficiently transmitting 360-degree video have been studying. However, the previous Viewport based Adaptive Streaming(VAS) using Motion-Constrained Tile Sets(MCTS)(MCTS-VAS) method requires a Random Access Point(RAP) frame when a user switches a viewport, which causes a load on the server and video delay due to transmission of a high bit rate. This paper proposes a VAS method using Intra Coded Pictures(ICP) to minimize the sudden increase in bit rate during viewport switching in the existing MCTS VAS scheme. In the experiment, the proposed ICP based MCTS VAS method showed a 13% reduction in BD(Bjontegaard Delta)-rate(%) compared to the existing MCTS VAS method.
스케일러블 비디오의 프레임 재생율을 이용한 비대칭 손실 보호 알고리즘
하호진(Hojin Ha),이경호(Kyongho Lee) 한국정보기술학회 2013 한국정보기술학회논문지 Vol.11 No.11
This paper proposes an unequal loss protection(ULP) algorithm for improving scalable video streaming quality over packet-lossy networks using the forward error correction(FEC) mechanism. The proposed ULP algorithm is developed by the unequal importance in both temporal and quality layers of hierarchical scalable video coding structure. For efficient FEC code assignment, the proposed ULP algorithm utilizes a simple and efficient performance metric, playable frame rate(PFR). The PFR is adopted for quantifying the unequal block recovery rate of temporal and quality layers. Compared to other ULP algorithms, the proposed ULP algorithm demonstrates higher PSNR values for various channel status.
RTSP 확장과 메타데이터를 이용한 광고 연동형 스트리밍 시스템 설계
하호진(Hojin Ha) 한국정보기술학회 2014 한국정보기술학회논문지 Vol.12 No.9
With the development of network and mobile devices, various multimedia services have been popular in recent years. Also to increase the profits of multimedia service, various advertisement insertion techniques has received significant attention. However, since previous streaming systems focus on main video playback or display of information related to the main video, problems occur to support a variety of advertising scenarios. In this paper, a streaming system for supporting various advertisement insertion scenarios is proposed. First, RTSP(Real-Time Streaming Protocol) is extended for efficient streaming controls between main and advertisement contents. Second, a new meta data structure is proposed for efficiently delivering the information of main and advertisement contents to the client for advertisement insertion. The proposed streaming system is implemented using JMF(Java Media Framework) and shows that it efficiently supports various advertisement insertion scenarios.
OFDM 시스템에서 스케일러블 비디오 전송을 위한 자원할당 알고리즘
하호진(Hojin Ha) 한국정보기술학회 2018 한국정보기술학회논문지 Vol.16 No.9
This paper proposes a resource allocation method for scalable video transmission in Orthogonal Frequency Division Multiplexing(OFDM) system. The proposed resource allocation method in limited system resources is designed to minimize bit rate distortion using both strong dependency in scalable layers and diversity of transport channels. First, we calculate the weight of error propagation for each layer using the asymmetry of error propagation based on hierarchical prediction structure of scalable video. In order to minimize the deterioration of the quality of the transmitted video, an algorithm for allocating OFDM system resources using the error propagation weight and status of the channel is performed. The proposed resource allocation algorithm showed 1.5-3.0dB performance improvement compared with the TDMA based resource allocation algorithm without considering layers based error propagation weight information.