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"Virtual storage (Computer science)"
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An Odyssey into Virtual Worlds: Exploring the Impacts of Technological and Spatial Environments on Intention to Purchase Virtual Products
Although research on three-dimensional virtual environments abounds, little is known about the social and business aspects of virtual worlds. Given the emergence of large-scale social virtual worlds, such as Second Life, and the dramatic growth in sales of virtual goods, it is important to understand the dynamics that govern the purchase of virtual goods in virtual worlds. Employing the stimulus—organism—response (S-O-R) framework, we investigate how technological (interactivity and sociability) and spatial (density and stability) environments in virtual worlds influence the participants' virtual experiences (telepresence, social presence, and flow), and how experiences subsequently affect their response (intention to purchase virtual goods). The results of our survey of 354 Second Life residents indicate that interactivity, which enhances the interaction with objects, has a significant positive impact on telepresence and flow. Also, sociability, which fosters interactions with participants, is significantly associated with social presence, although no such significant impact was observed on flow. Furthermore, both density and stability are found to significantly influence participants' virtual experiences; stability helps users to develop strong social bonds, thereby increasing both social presence and flow. However, contrary to our prediction of curvilinear patterns, density is linearly associated with flow and social presence. Interestingly, the results exhibit two opposing effects of density: while it reduces the extent of flow, density increases the amount of social presence. Since social presence is found to increase flow, the net impact of density on flow depends heavily on the relative strength of the associations involving these three constructs. Finally, we find that flow mediates the impacts of technological and spatial environments on intention to purchase virtual products. We conclude the paper with a discussion of the theoretical and practical contributions of our findings.
Journal Article
Enhancing Brand Equity Through Flow and Telepresence: A Comparison of 2D and 3D Virtual Worlds
This research uses theories of flow, telepresence, positive emotions, and brand equity to examine the effect of using two-dimensional versus three-dimensional virtual world environments on telepresence, enjoyment, brand equity, and behavioral intention. The findings suggest that the 3D virtual world environment produces both positive and negative effects on brand equity when compared to the 2D environment. The positive effect of the 3D virtual world environment on brand equity occurs through telepresence, a specific aspect of flow, as well as enjoyment. The negative effect on brand equity can be explained using distraction—conflict theory in which attentional conflicts faced by users of a highly interactive and rich medium resulted in distractions from attending to the brand. Brand equity, in turn, has a positive effect on behavioral intention. The results suggest that although the 3D virtual world environment has the potential to increase brand equity by offering an immersive and enjoyable virtual product experience, the rich environment can also be a distraction. Therefore, developers of virtual world branding sites need to take into account limitations in the information processing capacity and attention span of users when designing their sites in order to avoid cognitive overload, which can lead to users being distracted from branding information. This paper not only provides a theoretical foundation for explaining users' experience with 2D versus 3D virtual world branding sites, but also provides insights to practitioners for designing 3D virtual world sites to enhance brand equity and intentions through user engagement.
Journal Article
Inclusive AR/VR: accessibility barriers for immersive technologies
Augmented and virtual reality (AR/VR) hold significant potential to transform how we communicate, collaborate, and interact with others. However, there has been a lack of work to date investigating accessibility barriers in relation to immersive technologies for people with disabilities. To address current gaps in knowledge, we led two multidisciplinary sandpits with key stakeholders (including academic researchers, AR/VR industry specialists, people with lived experience of disability, assistive technologists, and representatives from national charities and special needs colleges) to collaboratively explore and identify existing challenges with AR and VR experiences. We present key themes that emerged from sandpit activities and map out the interaction barriers identified across a spectrum of impairments (including physical, cognitive, visual, and auditory disabilities). We conclude with recommendations for future work addressing the challenges highlighted to support the development of more inclusive AR and VR experiences.
Journal Article
Managing overloaded hosts for energy-efficiency in cloud data centers
Traditional data centers are shifted toward the cloud computing paradigm. These data centers support the increasing demand for computational and data storage that consumes a massive amount of energy at a huge cost to the cloud service provider and the environment. Considerable energy is wasted to constantly operate idle virtual machines (VMs) on hosts during periods of low load. Dynamic consolidation of VMs from overloaded or underloaded hosts is an effective strategy for improving energy consumption and resource utilization in cloud data centers. The dynamic consolidation of VM from an overloaded host directly influences the service level agreements (SLAs), utilization of resources, and quality of service (QoS) delivered by the system. We proposed an algorithm, namely,
GradCent
, based on the Stochastic Gradient Descent technique. This algorithm is used to develop an upper CPU utilization threshold for detecting overloaded hosts by using a real CPU workload. Moreover, we proposed a dynamic VM selection algorithm called Minimum Size Utilization (
MSU
) for selecting the VMs from an overloaded host for VM consolidation.
GradCent
and
MSU
maintain the trade-off between energy consumption minimization and QoS maximization under specified SLA goal. We used the CloudSim simulations with real-world workload traces from more than a thousand PlanetLab VMs. The proposed algorithms minimized energy consumption and SLA violation by 23% and 27.5% on average, compared with baseline schemes, respectively.
Journal Article
A new adaptive VR-based exergame for hand rehabilitation after stroke
The aim of this work is to present an adaptive serious game based on virtual reality (VR) for functional rehabilitation of the hand after stroke. The game focuses on simulating the palmar grasping exercise commonly used in clinical settings. The system’s design follows a user-centered approach, involving close collaboration with functional rehabilitation specialists and stroke patients. It uses the Leap motion controller to enable patient interaction in the virtual environment, which was created using the Unity 3D game engine. The system relies on hand gestures involving opening and closing movements to interact with virtual objects. It incorporates parameters to objectively measure participants’ performance throughout the game session. These metrics are used to personalize the game’s difficulty to each patient’s motor skills. To do this, we implemented an approach that dynamically adjusts the difficulty of the exergame according to the patient’s performance during the game session. To achieve this, we used an unsupervised machine learning technique known as clustering, in particular using the K-means algorithm. By applying this technique, we were able to classify patients’ performance into distinct groups, enabling us to assess their skill level and adapt the difficulty of the game accordingly. To evaluate the system’s effectiveness and reliability, we conducted a subjective evaluation involving 11 stroke patients. The standardized System Usability Scale (SUS) questionnaire was used to assess the system’s ease of use, while the Intrinsic Motivation Inventory (IMI) was used to evaluate the participants’ subjective experience with the system. Evaluations showed that our proposed system is usable and acceptable on a C-level scale, with a good adjective score, and the patients perceived a high intrinsic motivation.
Journal Article
Virtual reality in medical emergencies training: benefits, perceived stress, and learning success
Medical graduates lack procedural skills experience required to manage emergencies. Recent advances in virtual reality (VR) technology enable the creation of highly immersive learning environments representing easy-to-use and affordable solutions for training with simulation. However, the feasibility in compulsory teaching, possible side effects of immersion, perceived stress, and didactic benefits have to be investigated systematically. VR-based training sessions using head-mounted displays alongside a real-time dynamic physiology system were held by student assistants for small groups followed by debriefing with a tutor. In the pilot study, 36 students rated simulation sickness. In the main study, 97 students completed a virtual scenario as active participants (AP) and 130 students as observers (OBS) from the first-person perspective on a monitor. Participants completed questionnaires for evaluation purposes and exploratory factor analysis was performed on the items. The extent of simulation sickness remained low to acceptable among participants of the pilot study. In the main study, students valued the realistic environment and guided practical exercise. AP perceived the degree of immersion as well as the estimated learning success to be greater than OBS and proved to be more motivated post training. With respect to AP, the factor “sense of control” revealed a typical inverse U-shaped relationship to the scales “didactic value” and “individual learning benefit”. Summing up, curricular implementation of highly immersive VR-based training of emergencies proved feasible and found a high degree of acceptance among medical students. This study also provides insights into how different conceptions of perceived stress distinctively moderate subjective learning success.
Journal Article
Inclusion of third-person perspective in CAVE-like immersive 3D virtual reality role-playing games for social reciprocity training of children with an autism spectrum disorder
The present study aimed to improve the ability of children with autism to recognize emotions correctly. We used our third-person perspective role-playing game (TPP-RPG) method to teach social skills and help develop an improved understanding of the six basic emotions. The experiment was divided into two phases: The first involved working with traditional figure card emotional recognition and the second involved a subject entering a 3D cave automatic virtual environment (CAVE) to engage with interactive games. While the traditional graphic card is a static picture that represents one of the six basic human emotions, the virtual reality of CAVE-like immersive 3D role-playing games enables the use of actual picture scene syntheses plus the animation of 3D characters to express emotions. The participating children were instructed to role-play with (1) three-dimensional (3D) virtual role animations and observe (2) two different real-time switchable role-play animations of themselves and their counterpart socially interacting. This single-subject study was based on multiple-baseline, across-subject design and involved 5 weeks of TPP-RPG training intervention. From this research activity, we found that the role-play performance of all three participants rose substantially during the intervention phase and remained significantly higher in the maintenance phase compared to their baseline levels.
Journal Article
OpenStackDP: a scalable network security framework for SDN-based OpenStack cloud infrastructure
Network Intrusion Detection Systems (NIDS) and firewalls are the de facto solutions in the modern cloud to detect cyberattacks and minimize potential hazards for tenant networks. Most of the existing firewalls, perimeter security, and middlebox solutions are built on static rules/signatures or simple rule matching, making them inflexible, susceptible to bugs, and difficult to introduce new services. This paper aims to improve network management in OpenStack Clouds by taking advantage of the combination of software-defined networking (SDN), Network Function Virtualization (NFV), and machine learning/artificial intelligence (ML/AI) and for making networks more predictable, reliable, and secure. Artificial intelligence is being used to monitor the behavior of the virtual machines and applications running in the OpenStack SDN cloud so that when any issues or degradations are noticed, the decision can be quickly made on how to handle that issue, being able to analyze data in motion, starting at the edge. The OpenStackDP framework comprises lightweight monitoring, anomaly-detecting intelligent sensors embedded in the data plane, a threat analytics engine based on ML/AI algorithms running inside switch hardware/network co-processor, and defensive actions deployed as virtual network functions (VNFs). This network data plane-based architecture makes high-speed threat detection and rapid response possible and enables a much higher degree of security. We have built the framework with advanced streaming analytics technologies, algorithms, and machine learning to draw knowledge from this data that is in motion before the malicious traffic goes to the tenant compute nodes or long-term data store. Cloud providers and users will benefit from improved Quality-of-Services (QoS) and faster recovery from cyber-attacks and compromised switches. The multi-phase collaborative anomaly detection scheme demonstrates an accuracy of 99.81%, average latencies of 0.27 ms, and response speed within 9 s. The simulations and analysis show that the OpenStackDP network analytics framework substantially secures and outperforms prior SDN-based OpenStack solutions for Cloud architectures.
Journal Article
Data management in digital twins: a systematic literature review
The Internet of Things (IoT) and continuous advances in data-gathering devices and techniques have significantly increased the amount of relevant data that can be leveraged for innovative real-time, data-driven applications. Digital Twins (DTs) are virtual representations of physical objects, which are fully integrated and in which the automatic data exchange occurs in a bidirectional way. Modern DTs follow a five-component architecture, which includes an explicit Data Management (DM) component that acts as a bridge between the other systems. However, there is no clarity on its role and functionalities. This article presents a Systematic Literature Review on DM solutions proposed in the DT context. We analyzed DM under the Big Data chain of activities to add value to data, highlighting key issues to be addressed: data heterogeneity, interoperability, integration, data search, and quality. In addition to surveying existing solutions for handling these issues, we contextualized them in the domain and function for which the DT was proposed, the type of data dealt with, and the technological infrastructure. Our main findings revealed that the maturity level assumed for the DM component is at an early stage. The most mature solutions were proposed for the industry domain, and many of them assume humans as the ultimate information consumers. Data integration is the prevalent DM issue addressed due to the bridging role of the DM component, and cloud computing is the key implementation technology. Among the research opportunities are reference data management architectures, adoption of industry standards and ontologies, interoperability among distinct DTs, the development of agnostic standard implementations, and data provenance mechanisms.
Journal Article