Abstract
The explosion of blockchain projects in last couple of years shows the general interest in the blockchain technology. Looking towards the current state of the art regarding this technology it becomes clear that the main driver of innovation is the private sector. We believe that understanding main applications of the technology, academic contributions, and private solutions can reveal where the interest in the technology exists and where it can be missing. In particular, this work can help identify open source projects that can provide a framework with next-generation features as; lightning network, directed acyclic graph, mobile compatibility, or compute protocols. New applications of the blockchain technology are still being discovered regularly and in this study several blockchain development frameworks were found. However, in the academic world there are few references to operational, testing, and deployment framework related with the technology. With the expected growth of the technology, integration with preexisting solutions, legacy systems replacement, or new implementations, the need for testing, deploying, exploration, and maintenance is expected to intensify for the technology.

Abstract
When engaged in communication, people often rely on pointing gestures to refer to out-of-reach content. However, observers frequently misinterpret the target of a pointing gesture. Previous research suggests that to perform a pointing gesture, people place the index finger on or close to a line connecting the eye to the referent, while observers interpret pointing gestures by extrapolating the referent using a vector defined by the arm and index finger. In this paper we present Warping Deixis, a novel approach to improving the perception of pointing gestures and facilitate communication in collaborative Extended Reality environments. By warping the virtual representation of the pointing individual, we are able to match the pointing expression to the observer's perception. We evaluated our approach in a co-located side by side virtual reality scenario. Results suggest that our approach is effective in improving the interpretation of pointing gestures in shared virtual environments.

Abstract
Common natural walking techniques for navigating in virtual environments feature constraints that make it difficult to use those methods in cramped home environments. Indeed, natural walking requires unobstructed and open space, to allow users to roam around without fear of stumbling on obstacles while immersed in a virtual world. In this work, we propose a new virtual locomotion technique, CWIP-AVR, that allows people to take advantage of the available physical space and empowers them to use natural walking to navigate in the virtual world. To inform users about real world hazards our approach uses augmented virtual reality visual indicators. A user evaluation suggests that CWIP-AVR allows people to navigate safely, while switching between locomotion modes flexibly and maintaining a adequate degree of immersion. © 2019 Association for Computing Machinery.

Abstract
Face-to-face telepresence promotes the sense of "being there" and can improve collaboration by allowing immediate understanding of remote people's nonverbal cues. Several approaches successfully explored interactions with 2D content using a see-through whiteboard metaphor. However, with 3D content, there is a decrease in awareness due to ambiguities originated by participants' opposing points-of-view. In this paper, we investigate how people and content should be presented for discussing 3D renderings within face-to-face collaborative sessions. To this end, we performed a user evaluation to compare four different conditions, in which we varied reflections of both workspace and remote people representation. Results suggest potentially more benefits to remote collaboration from workspace consistency rather than people's representation fidelity.We contribute a novel design space, the Negative Space, for remote face-to-face collaboration focusing on 3D content. © 2019 Association for Computing Machinery.

Abstract
The rapid increase of connected devices causes more and more data to be generated and, in some cases, this data needs to be analyzed as it is received. As such, the challenge of presenting streaming data in such way that changes in the regular flow can be detected needs to be tackled, so that timely and informed decisions can be made. This requires users to be able to perceive the information being received in the moment in detail, while maintaining the context. In this paper, we propose VisMillion, a visualization technique for large amounts of streaming data, following the concept of graceful degradation. It is comprised of several different modules positioned side by side, corresponding to different contiguous time spans, from the last few seconds to a historical view of all data received in the stream so far. Data flows through each one from right to left and, the more recent the data, the more detailed it is presented. To this end, each module uses a different technique to aggregate and process information, with special care to ensure visual continuity between modules to facilitate the analysis. VisMillion was validated through a usability evaluation with 21 participants, as well as performance tests. Results show that it fulfills its objective, successfully aiding users to detect changes, patterns and anomalies in the information being received.

Abstract
Modern volumetric projection-based telepresence approaches are capable of providing realistic full-size virtual representations of remote people. Interacting with full-size people may not be desirable due to the spatial constraints of the physical environment, application context, or display technology. However, the miniaturization of remote people is known to create an eye gaze matching problem. Eye-contact is essential to communication as it allows for people to use natural nonverbal cues and improves the sense of "being there". In this paper we discuss the design space for interacting with volumetric representations of people and present an approach for dynamically manipulating scale, orientation and the position of holograms which guarantees eye-contact. We created a working augmented reality-based prototype and validated it with 14 participants.