http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
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.
패킷 손실 네트워크에서 스케일러블 비디오를 위한 비대칭 에러 전파 기반 FEC 알고리즘
하호진(Hojin Ha) 한국정보기술학회 2013 한국정보기술학회논문지 Vol.11 No.2
This paper proposes an efficient unequal forward error correction(FEC) algorithm for scalable video transmission over packet-erasure networks. Layer-based scalable video occurs a lot of quality degradation due to the strong dependencies between base layer and enhancement layers So the proposed algorithm, firstly proposes the novel layer-based error propagation model considering both hierarchical coding structure for temporal scalability and layer dependencies for quality scalability. Then based on the proposed error propagation model and the current packet loss rate, the FEC assignment algorithm is proposed for minimizing the degradation of video quality. Compared with the previous FEC methods, the proposed method shows large amounts of quality improvements in various channel environments.
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.
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.
PZT 구동 나노 정밀도 스테이지를 위한 퍼지 제어기 개발
하호진(Hojin Ha),정규원(Kyuwon Jeong) 한국생산제조학회 2009 한국생산제조학회지 Vol.18 No.2
An ultra-precision stage is used in many industrial areas such as precision machine tools or semiconductor apparatus. These stages used to be driven by piezoelectric actuators in order to obtain ultra precision positioning resolution. Piezoelectric actuator can be moved fast in nanometer resolution. However, it has relatively large non-linear characteristics like hysteresis and creep curve. Although several kinds of control techniques have been developed, controller design method is still complicated. In this paper fuzzy control rules are developed intuitively. In order to verify the performance a series of experiments were conducted and the results were compared with those of the PID controller case.
강인한 스케일러블 비디오 전송을 위한 무선 채널의 손실 분포 기반 비대칭 손실 보호 알고리즘
하호진(Hojin Ha) 한국정보기술학회 2013 한국정보기술학회논문지 Vol.11 No.3
This paper presents an unequal loss protection (ULP) scheme considering wireless channel characteristics for scalable video transmission with distortion minimization over wireless networks. Since previous ULP algorithms for scalable video utilize only the dependencies in scalable layers, burst packet loss in wireless communication significantly decreases the quality of video. In this paper, firstly, we propose the novel error propagation model including the amount of error propagation in scalable video layers and the packet loss characteristics according to variable channel status. Packet loss characteristics are exploited for improving the recovery rate by error correction in scalable layers. Then we propose the model-based unequal loss protection assignment algorithm. Compared to previous ULP schemes, simulation results show that the proposed ULP scheme gives substantial improvement for the received video quality and the graceful degradation of video quality in various packet loss rate environments.