Social viewing in cinematic virtual reality: a design space for social movie applications

Since watching movies is a social experience for most people, it is important to know how an application should be designed for enabling shared cinematic virtual reality (CVR) experiences via head-mounted displays (HMDs). Viewers can feel isolated when watching omnidirectional movies with HMDs. Even if they are watching the movie simultaneously, they do not automatically see the same field of view, since they can freely choose their viewing direction. Our goal is to explore interaction techniques to efficiently support social viewing and to improve social movie experiences in CVR. Based on the literature review and insights from earlier work, we identify seven challenges that need to be addressed: communication, field-of-view (FoV) awareness, togetherness, accessibility, interaction techniques, synchronization, and multiuser environments. We investigate four aspects (voice chat, sending emotion states, FoV indication, and video chat) to address some of the challenges and report the results of four user studies. Finally, we present and discuss a design space for CVR social movie applications and highlight directions for future work.

Public Key Encryption with Keyword Search from Lattices in Multiuser Environments

A public key encryption scheme with keyword search capabilities is proposed using lattices for applications in multiuser environments. The proposed scheme enables a cloud server to check if any given encrypted data contains certain keywords specified by multiple users, but the server would not have knowledge of the keywords specified by the users or the contents of the encrypted data, which provides data privacy as well as privacy for user queries in multiuser environments. It can be proven secure under the standard learning with errors assumption in the random oracle model.

Random-Access Technique for Self-Organization of 5G Millimeter-Wave Cellular Communications

The random-access (RA) technique is a key procedure in cellular networks and self-organizing networks (SONs), but the overall processing time of this technique in millimeter-wave (mm-wave) cellular systems with directional beams is very long because RA preambles (RAPs) should be transmitted in all directions of Tx and Rx beams. In this paper, two different types of preambles (RAP-1 and RAP-2) are proposed to reduce the processing time in the RA stage. After analyzing the correlation property, false-alarm probability, and detection probability of the proposed RAPs, we perform simulations to show that the RAP-2 is suitable for RA in mm-wave cellular systems with directional beams because of the smaller processing time and high detection probability in multiuser environments.