The effect of transition type in multi-view 360 media

360-degree images and video have become extremely popular formats for immersive displays, due in large part to the technical ease of content production. While many experiences use a single camera viewpoint, an increasing number of experiences use multiple camera locations. In such multi-view 360-degree media (MV360M) systems, a visual effect is required when the user transitions from one camera location to another. This effect can take several forms, such as a cut or an image-based warp, and the choice of effect may impact many aspects of the experience, including issues related to enjoyment and scene understanding. To investigate the effect of transition types on immersive MV360M experiences, a repeated-measures experiment was conducted with 31 participants. Wearing a head-mounted display, participants explored four static scenes, for which multiple 360-degree images and a reconstructed 3D model were available. Three transition types were examined: teleport, a linear move through a 3D model of the scene, and an image-based transition using a Mobius transformation. The metrics investigated included spatial awareness, users’ movement profiles, transition preference and the subjective feeling of moving through the space. Results indicate that there was no significant difference between transition types in terms of spatial awareness, while significant differences were found for users’ movement profiles, with participants taking 1.6 seconds longer to select their next location following a teleport transition. The model and Mobius transitions were significantly better in terms of creating the feeling of moving through the space. Preference was also significantly different, with model and teleport transitions being preferred over Mobius transitions. Our results indicate that trade-offs between transitions will require content creators to think carefully about what aspects they consider to be most important when producing MV360M experiences

Examining the role of smart TVs and VR HMDs in synchronous at-a-distance media consumption

This article examines synchronous at-a-distance media consumption from two perspectives: How it can be facilitated using existing consumer displays (through TVs combined with smartphones), and imminently available consumer displays (through virtual reality (VR) HMDs combined with RGBD sensing). First, we discuss results from an initial evaluation of a synchronous shared at-a-distance smart TV system, CastAway. Through week-long in-home deployments with five couples, we gain formative insights into the adoption and usage of at-a-distance media consumption and how couples communicated during said consumption. We then examine how the imminent availability and potential adoption of consumer VR HMDs could affect preferences toward how synchronous at-a-distance media consumption is conducted, in a laboratory study of 12 pairs, by enhancing media immersion and supporting embodied telepresence for communication. Finally, we discuss the implications these studies have for the near-future of consumer synchronous at-a-distance media consumption. When combined, these studies begin to explore a design space regarding the varying ways in which at-a-distance media consumption can be supported and experienced (through music, TV content, augmenting existing TV content for immersion, and immersive VR content), what factors might influence usage and adoption and the implications for supporting communication and telepresence during media consumption

Virtual viewpoint three-dimensional panorama

Conventional panoramic images are known to provide for an enhanced field of view in which the scene always has a fixed appearance. The idea presented in this paper focuses on the use of the concept of virtual viewpoint creation to generate different panoramic images of the same scene with three-dimensional component. Three-dimensional effect in a resultant panorama is realized by superimposing a stereo-pair of panoramic images

Entering the Economic Models of Game Console Manufacturers

This paper deals with the video game console market. We are not interested here in portable consoles nor in PC games. Our work focuses on the role of core competencies in console wars, analyzing the way these competencies are activated within the firms' business models. The home console market also exhibits crossed network externalities, which requires console manufacturers the ability to conciliate the interests of both developers and gamers. From a strategic point of view, core competencies are closely related with market performance. Today, Sony's and Microsoft's business models are quite similar. However, Microsoft and Sony remain far behind Nintendo and its Wii, which suggests that core competencies do not discriminate on performance as much as the positioning choices made upstream when the strategy is crafted. The link between core competencies, economic model and strategy is at the heart of this study.video game console, business model, core competencies, two-sided market, platform.

Expression of the angular dependence of the quantum efficiency for a thin multi-alkali photocathode and its optical properties

The dependence of the quantum efficiency on the angle and polarization of the incident photon needs to be formulated for a precise description of the response of photomultiplier tubes. A simplified one-step model of photoelectron emission was derived from Spicer's three-step model, and it enabled the formulation of the dependence of the quantum efficiency in the visible range for thin multi-alkali (NaKSbCs) photocathodes. The expression of the quantum efficiency was proved by a measurement of the photocurrent for linearly polarized light at various incident angles. Meanwhile, the measurement revealed the complex refractive indices and thicknesses both of the stratified photocathode and antireflection coating. It is indicated that the angular dependence of the quantum efficiency is dictated by the optical properties of the photocathode, which are discussed in detail on the basis of the obtained parameters

Experimental and numerical investigation of Helmholtz resonators and perforated liners as attenuation devices in industrial gas turbine combustors

This paper reports upon developments in the simulation of the passive control of combustion dynamics in industrial gas turbines using acoustic attenuation devices such as Helmholtz resonators and perforated liners. Combustion instability in gas turbine combustors may, if uncontrolled, lead to large-amplitude pressure fluctuations, with consequent serious mechanical problems in the gas turbine combustor system. Perforated combustor walls and Helmholtz resonators are two commonly used passive instability control devices. However, experimental design of the noise attenuation device is time-consuming and calls for expensive trial and error practice. Despite significant advances over recent decades, the ability of Computational Fluid Dynamics to predict the attenuation of pressure fluctuations by these instability control devices is still not well validated. In this paper, the attenuation of pressure fluctuations by a group of multi-perforated panel absorbers and Helmholtz resonators are investigated both by experiment and computational simulation. It is demonstrated that CFD can predict the noise attenuation from Helmholtz resonators with good accuracy. A porous material model is modified to represent a multi-perforated panel and this perforated wall representation approach is demonstrated to be able to accurately predict the pressure fluctuation attenuation effect of perforated panels. This work demonstrates the applicability of CFD in gas turbine combustion instability control device design

Cavity controlled spectral singularity

We study theoretically a PT-symmetric saturable balanced gain-loss system in a ring cavity configuration. The saturable gain and loss are modeled by two-level medium with or without population inversion. We show that the specifics of the spectral singularity can be fully controlled by the cavity and the atomic detuning parameters. The theory is based on the mean-field approximation as in standard theory of optical bistability. Further, in the linear regime we demonstrate the regularization of the singularity in detuned systems, while larger input power levels are shown to be adequate to limit the infinite growth in absence of detunin