Temporal perception of visual-haptic events in multimodal telepresence system

Book synopsis: Haptic interfaces are divided into two main categories: force feedback and tactile. Force feedback interfaces are used to explore and modify remote/virtual objects in three physical dimensions in applications including computer-aided design, computer-assisted surgery, and computer-aided assembly. Tactile interfaces deal with surface properties such as roughness, smoothness, and temperature. Haptic research is intrinsically multi-disciplinary, incorporating computer science/engineering, control, robotics, psychophysics, and human motor control. By extending the scope of research in haptics, advances can be achieved in existing applications such as computer-aided design (CAD), tele-surgery, rehabilitation, scientific visualization, robot-assisted surgery, authentication, and graphical user interfaces (GUI), to name a few. Advances in Haptics presents a number of recent contributions to the field of haptics. Authors from around the world present the results of their research on various issues in the field of haptics

Ratings are overrated!

Are ratings of any use in human–computer interaction and user studies at large? If ratings are of limited use, is there a better alternative for quantitative subjective assessment? Beyond the intrinsic shortcomings of human reporting, there are a number of supplementary limitations and fundamental methodological flaws associated with rating-based questionnaires – i.e., questionnaires that ask participants to rate their level of agreement with a given statement, such as a Likert item. While the effect of these pitfalls has been largely downplayed, recent findings from diverse areas of study question the reliability of using ratings. Rank-based questionnaires – i.e., questionnaires that ask participants to rank two or more options – appear as the evident alternative that not only eliminates the core limitations of ratings but also simplifies the use of sound methodologies that yield more reliable models of the underlying reported construct: user emotion, preference, or opinion. This paper solicits recent findings from various disciplines interlinked with psychometrics and offers a quick guide for the use, processing, and analysis of rank-based questionnaires for the unique advantages they offer. The paper challenges the traditional state-of-practice in human–computer interaction and psychometrics directly contributing toward a paradigm shift in subjective reporting.peer-reviewe

Experimental investigation of radio signal propagation in scientific facilities for telerobotic applications

Understanding the radio signal transmission characteristics in the environment where the telerobotic application is sought is a key part of achieving a reliable wireless communication link between a telerobot and a control station. In this paper, wireless communication requirements and a case study of a typical telerobotic application in an underground facility at CERN are presented. Then, the theoretical and experimental characteristics of radio propagation are investigated with respect to time, distance, location and surrounding objects. Based on analysis of the experimental findings, we show how a commercial wireless system, such as Wi-Fi, can be made suitable for a case study application at CERN

Congestion Control for Network-Aware Telehaptic Communication

Telehaptic applications involve delay-sensitive multimedia communication between remote locations with distinct Quality of Service (QoS) requirements for different media components. These QoS constraints pose a variety of challenges, especially when the communication occurs over a shared network, with unknown and time-varying cross-traffic. In this work, we propose a transport layer congestion control protocol for telehaptic applications operating over shared networks, termed as dynamic packetization module (DPM). DPM is a lossless, network-aware protocol which tunes the telehaptic packetization rate based on the level of congestion in the network. To monitor the network congestion, we devise a novel network feedback module, which communicates the end-to-end delays encountered by the telehaptic packets to the respective transmitters with negligible overhead. Via extensive simulations, we show that DPM meets the QoS requirements of telehaptic applications over a wide range of network cross-traffic conditions. We also report qualitative results of a real-time telepottery experiment with several human subjects, which reveal that DPM preserves the quality of telehaptic activity even under heavily congested network scenarios. Finally, we compare the performance of DPM with several previously proposed telehaptic communication protocols and demonstrate that DPM outperforms these protocols.Comment: 25 pages, 19 figure

High Responsiveness for Group Editing CRDTs

International audienceGroup editing is a crucial feature for many end-user applications. It requires high responsiveness, which can be provided only by optimistic replication algorithms, which come in two classes: classical Operational Transformation (OT), or more recent Conflict-Free Replicated Data Types (CRDTs). Typically, CRDTs perform better on downstream operations , i.e., when merging concurrent operations than OT, because the former have logarithmic complexity and the latter quadratic. However, CRDTs are often less responsive, because their upstream complexity is linear. To improve this, this paper proposes to interpose an auxiliary data structure , called the identifier data structure in front of the base CRDT. The identifier structure ensures logarithmic complexity and does not require replication or synchronization. Combined with a block-wise storage approach, this approach improves upstream execution time by several orders of magnitude , with negligeable impact on memory occupation, network bandwidth, and downstream execution performance

Controlled conflict resolution for replicated document

International audienceCollaborative working is increasingly popular, but it presents challenges due to the need for high responsiveness and disconnected work support. To address these challenges the data is optimistically replicated at the edges of the network, i.e. personal computers or mobile devices. This replication requires a merge mechanism that preserves the consistency and structure of the shared data subject to concurrent modifications. In this paper, we propose a generic design to ensure eventual consistency (every replica will eventually view the same data) and to maintain the specific constraints of the replicated data. Our layered design provides to the application engineer the complete control over system scalability and behavior of the replicated data in face of concurrent modifications. We show that our design allows replication of complex data types with acceptable performances

Evaluating CRDTs for Real-time Document Editing

International audienceNowadays, real-time editing systems are catching on. Tools such as Etherpad or Google Docs enable multiple authors at dispersed locations to collaboratively write shared documents. In such systems, a replication mechanism is required to ensure consistency when merging concurrent changes performed on the same document. Current editing systems make use of operational transformation (OT), a traditional replication mechanism for concurrent document editing. Recently, Commutative Replicated Data Types (CRDTs) were introduced as a new class of replication mechanisms whose concurrent operations are designed to be natively commutative. CRDTs, such as WOOT, Logoot, Treedoc, and RGAs, are expected to be substitutes of replication mechanisms in collaborative editing systems. This paper demonstrates the suitability of CRDTs for real-time collaborative editing. To reflect the tendency of decentralised collaboration, which can resist censorship, tolerate failures, and let users have control over documents, we collected editing logs from real-time peer-to-peer collaborations. We present our experiment results obtained by replaying those editing logs on various CRDTs and an OT algorithm implemented in the same environment

3D Virtual Worlds and the Metaverse: Current Status and Future Possibilities

Moving from a set of independent virtual worlds to an integrated network of 3D virtual worlds or Metaverse rests on progress in four areas: immersive realism, ubiquity of access and identity, interoperability, and scalability. For each area, the current status and needed developments in order to achieve a functional Metaverse are described. Factors that support the formation of a viable Metaverse, such as institutional and popular interest and ongoing improvements in hardware performance, and factors that constrain the achievement of this goal, including limits in computational methods and unrealized collaboration among virtual world stakeholders and developers, are also considered

Reducing the effect of network delay on tightly-coupled interaction

Tightly-coupled interaction is shared work in which each person’s actions immediately and continuously influence the actions of others. Tightly-coupled interaction is a hallmark of expert behaviour in face-to-face activity, but becomes extremely difficult to accomplish in distributed groupware. The main cause of this difficulty is network delay – even amounts as small as 100ms – that disrupts people’s ability to synchronize their actions with another person. To reduce the effects of delay on tightly-coupled interaction, I introduce a new technique called Feedback-Feedthrough Synchronization (FFS). FFS causes visual feedback from an action to occur at approximately the same time for both the local and the remote person, preventing one person from getting ahead of the other in the coordinated interaction. I tested the effects of FFS on group performance in several delay conditions, and my study showed that FFS substantially improved users’ performance: accuracy was significantly improved at all levels of delay, and without noticeable increase in perceived effort or frustration. Techniques like FFS that support the requirements of tightly-coupled interaction provide new means for improving the usability of groupware that operates on real-world networks