• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.51-54
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• 2020

본 논문에서는 360 도 VR 영상을 전송하는 기법의 일종인 타일 기반 전송을 MMT(MPEG Media Transport) 프로토콜 기반으로 구현하기 위하여 영상의 공간 분할 정보를 전달하는 방법을 소개한다. 360 도 VR 영상 전송은 대용량 미디어 전송인 동시에 사용자의 움직임에 따라 신속하게 적응적 영상을 전달해야 한다. 타일 기반 전송은 HEVC(High Efficiency Video Coding)의 MCTS(Motion Constrained Tile Sets) 기법을 이용하여 뷰포트에 해당하는 타일들을 고화질로 전달함으로써 이러한 요구사항을 해결한다. 반면, MMT 프로토콜은 초저지연 고화질 영상 전송에 유리한 기술로써 사용자의 시점 변화에 따라 기민하게 영상의 품질을 변환시킬 수 있다. 따라서 HEVC 의 SEI(Supplemental Enhancement Information) 메시지에 포함되는 타일들의 공간 분할 정보를 MMT 프로토콜에 적용하는 방식에 따라 적응적 타일 기반 전송 기법의 효율을 높일 수 있다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.06a
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• pp.359-360
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• 2016

본 논문에서는 초고화질의 비디오 실시간 복호화를 위해 HEVC(High Efficiency Video Coding)에서 지원하는 병렬화 기술인 Slice와 Tile 기술을 이용하여 초고해상도 영상에 대한 복호화기 병렬화 성능을 비교한다. Slice와 Tile은 분할 데이터간 의존성이 존재하지 않으므로 분할된 데이터를 다중 스레드에 할당하여 데이터-레벨 병렬화를 수행하였다. 실험 결과에서는 병렬화된 복호화기 성능이 기존 순차 복호화기에 비해 최대 2.08배 고속화 되었고, 분할 데이터 수가 증가하여도 화질 손실이 거의 없는 결과를 보인다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2017.11a
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• pp.49-50
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• 2017

야외에서 촬영 된 VR(Virtual Reality) 비디오는 의도하지 않은 흔들림을 동반한다. 흔들림을 포함한 VR 비디오는 사용자에게 시각적 피로감을 주고 몰입도를 저하시키기 때문에 VR 비디오의 흔들림을 제거하는 기술은 중요하다. 본 논문에서는 촬영 과정에서 흔들림이 발생한 VR 비디오 신호를 스티칭 단계 이전에 흔들림 보정하여 안정된 $360^{\circ}$ 비디오를 얻을 수 있는 알고리즘을 제안한다.

• Journal of Broadcast Engineering
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• v.26 no.5
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• pp.508-518
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• 2021

Recently as a result of covid 19, it has emphasis on the importance of non-contact. VR content has been attracting attention as an alternative to visual arts, media art, new media exhibitions and performances with limited offline activities. Although interest in 360 VR video contents such as VR contents for exhibitions and performances is increasing, research on immersion and satisfaction is focused on games and animation VR contents. In this paper, it verified the effect of the difference in the position and height of the VR camera in exhibitions and performances on the user's presence and satisfaction. For this experiment, the presence and satisfaction were measured after experiencing the VR contents of the convergence exhibition and performance filmed at different locations and heights. As a result of the experiment, the difference of VR camera's position had a significant effect on presence and satisfaction, the difference of VR camera's height had a significant effect only Realistic immersion of the presence.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.135-140
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• 2023

VR animation allows you to see 360-degree screen production that cannot be seen in existing animation production while being located in the space within the animation. <Goodbye Mr Octopus>, a VR animation produced in 2020, was selected at the 77th Venice Film Festival as an immersive short film. This is the story of an adolescent girl, Stella, who is celebrating her 16th birthday, and her conflict with her strict father is resolved through a letter from her mother. It is a narrative composed of a total of 11 scenes, and in each scene, new directing elements of VR video grammar, such as gaze induction, time flow, and space conversion directing, were analyzed. Gaze-inducing directing minimized the inconvenience of 360-degree gaze, and time and space conversion directing was analyzed as an effect of increasing the audience's immersion according to narrative events.

• Cartoon and Animation Studies
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• s.47
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• pp.1-29
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• 2017

360-degree virtual reality has been a technology that has been available for a long time and has been actively promoted worldwide in recent years due to development of devices such as HMD (Head Mounted Display) and development of hardware for controlling and executing images of virtual reality. The production of the 360 degree VR requires a different mode of production than the traditional video production, and the matters to be considered for the user have begun to appear. Since the virtual reality image is aimed at a platform that requires enthusiasm, presence and interaction, it is necessary to have a suitable cinematography. In VR, users can freely enjoy the world created by the director and have the advantage of being able to concentrate on his interests during playing the image. However, the director had to develope and install the device what the observer could concentrate on the narrative progression and images to be delivered. Among the various methods of transmitting images, the director can use the composition of the short. In this paper, we will study how to effectively apply the technique of directing through the composition of this shot to 360 degrees virtual reality. Currently, there are no killer contents that are still dominant in the world, including inside and outside the country. In this situation, the potential of virtual reality is recognized and various images are produced. So the way of production follows the traditional image production method, and the shot composition is the same. However, in the 360 degree virtual reality, the use of the long take or blocking technique of the conventional third person view point is used as the main production configuration, and the limit of the short configuration is felt. In addition, while the viewer can interactively view the 360-degree screen using the HMD tracking, the configuration of the shot and the connection of the shot are absolutely dependent on the director like the existing cinematography. In this study, I tried to study whether the viewer can freely change the cinematography such as the composition of the shot at a user's desired time using the feature of interaction of the VR image. To do this, 3D animation was created using a game tool called Unreal Engine to construct an interactive image. Using visual scripting of Unreal Engine called blueprint, we create a device that distinguishes the true and false condition of a condition with a trigger node, which makes a variety of shorts. Through this, various direction techniques are developed and related research is expected, and it is expected to help the development of 360 degree VR image.

• Fire Science and Engineering
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• v.28 no.4
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• pp.14-20
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• 2014

The purpose of this study is to analyze combustion patterns by filling a specific container with a flammable liquid and performing combustion tests in a divided space. The container used for the test is made of plastic, 20 mm in depth and 150 mm in width. After the liquid was ignited, its combustion process was photographed using a digital camera and video camera. It was found that in the case of benzene, the flame reached its peak at the fastest speed about 60 s while in the case of alcohol, the flame reached its peak at the lowest speed about 360 s, which is approximately six times slower than the benzene. In most cases, when the flame reached its peak, smoke generated was dark as the plastic container and flammable liquid were combusted simultaneously. After completion of the combustion, it was possible to sample oil vapor from all flammable liquids excluding soybean oil as a result of the examination of oil vapor using a crime investigation tube. That is, it can be seen that there is significant difference in flame propagation speed, pattern, etc., depending on the combustible substances.

• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.65-74
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• 2006

This study was attempted to Kinematical characteristics of the Endo $360^{\circ}$El-grip Swing on the horizontal bar. To do this, we selected and analyzed the performance of two athletes who did Endo $360^{\circ}$El-grip Swing in the horizontal bar competition of male artistic gymnastic in the 22nd Universiad Games 2003 Daegu. We drew the conclusions from the kinematical factors that were came out through analyzing three-dimensional cinematography of the athletes' movements, by using two video cameras. In point of analyzing the actual competition situation, it is expected that gymnastics and coaches have the effective informations, and the following conclusion had resulted. 1. When performing Endo $360^{\circ}$El-Grip, the average for entire required time was $1.93{\pm}0.06sec$. The average for descent phase time was $0.24{\pm}0.02sec$, ascent phase time was 0.22${\pm}0.07sec$, connecting phase time was $0.87{\pm}0.07sec$, and El-Grip phase time was $0.61{\pm}0.02sec$. The descent phase need short period of time but however to have a stable performance, ensuring ascent and connecting phase time are needed. El-Grip phase need short period of time to have a stable re-grasp. 2. To have a convenient preparation for El-Grip in descent and ascent phase, lowering CM, and ease up in sway and plunge from the High Bar would make descent and ascent even more faster and would have increase effect in trunk rotation. 3. In descent and ascent phase, if shoulder angle and arm slope is dwindling then it would effect rotation angle so might risk it from hitting a Bar when putting legs in and out. 4. In connecting phase, it requires some time to show stable performance when El-Grip phase is continued by using hip angle which would make trunk rotation angle bigger and make descent and ascent time slower. 5. In El-Grip phase, when doing motions like hand standing. using hip angle more than maximum would make CM even faster and it is stable position while performing.

• Journal of Korea Multimedia Society
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• v.21 no.8
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• pp.991-1001
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• 2018

In the context of the 4th Industrial Revolution, IoT, Big Data, and VR are rapidly emerging as core sectors of future industries. In particular, the VR has been under the limelight as a new media content appealing to new generation. And the VR user is not merely a 'spectator', but the 'actor'. In other words, the newness of VR is not in the 'more likely representation of the virtual reality', but in the 'making it act more virtual (more technically, 'interactive')' in the virtual world. In this paper, we examine the VR cinema in terms of film composition unit, montage, cinematic space, mise-en-$sc{\grave{e}}ne$ and perspective. The VR cinema, which is in the early stage of evolution, is basically based on $360^{\circ}$ image that strengthens the autonomy of the audience's point of view, but other factors like haptic or sonic immersion are becoming increasingly important. In addition, the VR cinema will be combined with AR, MR, SR, and Interactive technologies, and will expand its horizon as it is produced in various forms. Therefore, it is expected that more detailed viewpoint will be applied in the subsequent study on VR cinema.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.7
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• pp.2531-2546
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• 2021

For several years, virtual reality (VR) and augmented reality (AR) technologies have been improving. However, some hurdles remain that slow down the distribution of VR and AR devices, such as head-mounted display (HMD), and related consumer content. One issue is VR motion sickness, which has been experienced by users using 360 degree VR content via HMD. This paper discusses the related international standardization work that classifies the factors causing VR sickness, and proposes the process for VR sickness level evaluation. Among the factors causing VR sickness, many research institutes regard minimizing MTP (Motion-to-Photon) latency as the key enabler to mitigate VR sickness. Thus, this paper introduces research trends of MTP latency measurement and MTP latency mitigation. This paper categorizes the research on MTP latency measurement into 2 categories of hardware-based approach and software code-level approach. The 2 approaches have different pros and cons depending on use-case, purpose, and architecture of each multimedia system. The pros and cons are addressed in this paper. Additionally, the research on mitigating MTP latency with diverse strategies such as proactive computing, caching, and edge server technology is explained, and compared to conventional technologies, shows improved performance.