Evaluating the accuracy of size perception in real and virtual environments

ManuscriptAccurate perception of the size of 3D objects depicted on 2D desktop displays is important for many applications. Whether users perceive objects depicted on a display to be the same size as comparable real world objects is not well understood. We propose using affordances judgments as a way of measuring the perceived size of objects depicted in desktop virtual environments and the real world. The methodology involves indicating whether or not a particular action can be performed in a given environment, making it a flexible measure that can be used across different display technologies. In two studies, we test users' perceptions of size by asking them to make affordance judgments in both the real world and a geometrically matched desktop virtual environment. In the first study, users judge whether they can grasp an object and in the second study, they judge whether they can fit their hand through an opening. In both experiments we show that users perceive the size of objects in the desktop virtual environment to be smaller than in the real world

Body language, security and e-commerce

Security is becoming an increasingly more important concern both at the desktop level and at the network level. This article discusses several approaches to authenticating individuals through the use of biometric devices. While libraries might not implement such devices, they may appear in the near future of desktop computing, particularly for access to institutional computers or for access to sensitive information. Other approaches to computer security focus on protecting the contents of electronic transmissions and verification of individual users. After a brief overview of encryption technologies, the article examines public-key cryptography which is getting a lot of attention in the business world in what is called public key infrastructure. It also examines other efforts, such as IBM’s Cryptolope, the Secure Sockets Layer of Web browsers, and Digital Certificates and Signatures. Secure electronic transmissions are an important condition for conducting business on the Net. These business transactions are not limited to purchase orders, invoices, and contracts. This could become an important tool for information vendors and publishers to control access to the electronic resources they license. As license negotiators and contract administrators, librarians need to be aware of what is happening in these new technologies and the impact that will have on their operations

The benefits of using a walking interface to navigate virtual environments

Navigation is the most common interactive task performed in three-dimensional virtual environments (VEs), but it is also a task that users often find difficult. We investigated how body-based information about the translational and rotational components of movement helped participants to perform a navigational search task (finding targets hidden inside boxes in a room-sized space). When participants physically walked around the VE while viewing it on a head-mounted display (HMD), they then performed 90% of trials perfectly, comparable to participants who had performed an equivalent task in the real world during a previous study. By contrast, participants performed less than 50% of trials perfectly if they used a tethered HMD (move by physically turning but pressing a button to translate) or a desktop display (no body-based information). This is the most complex navigational task in which a real-world level of performance has been achieved in a VE. Behavioral data indicates that both translational and rotational body-based information are required to accurately update one's position during navigation, and participants who walked tended to avoid obstacles, even though collision detection was not implemented and feedback not provided. A walking interface would bring immediate benefits to a number of VE applications

Feasibility and preliminary efficacy of remotely delivering cognitive training to people with schizophrenia using tablets.

Limited access to Cognitive Training (CT) for people with schizophrenia (SZ) prevents widespread adoption of this intervention. Delivering CT remotely via tablets may increase accessibility, improve scheduling flexibility, and diminish patient burden.In this reanalysis of data from a larger trial of CT, we compared two samples of individuals with SZ who chose to complete 40 h of CT either on desktop computers in the laboratory (N = 33) or remotely via iPads (N = 41). We examined attrition rates and adherence to training, and investigated whether remote iPad-based CT and in-person desktop-based CT induced significantly different improvements in cognitive and real-world functioning.The attrition rate was 36.6%. On average, participants completed 3.06 h of CT per week. There were no significant between-group differences in attrition and adherence to CT requirements. Participants who completed iPad-based CT were significantly younger and had lower symptoms at baseline compared to participants who completed CT on the lab desktops. Controlling for age and symptom severity, rANCOVA showed that iPad-based and desktop-based CT similarly and significantly improved verbal learning and problem solving. Main effects of time, at trend level significance, were evident in global cognition, verbal memory, quality of life, and social functioning. All group by time interactions were non-significant except for verbal memory, where iPad users showed greater gains. Within-group effect sizes for changes in outcomes were in the small range.Although underpowered and not randomized, this study demonstrates that delivering CT remotely to people with SZ using tablets is feasible and results in retention rates, adherence, and cognitive and functional outcome improvements that are comparable to those observed when CT is delivered in the laboratory. This has important implications in terms of scalability and dissemination of CT. These results require confirmation in larger samples

The Role of Attention for Visual Perception in Desktop Virtual Reality Environments

Virtual Reality Environments (VRE) is relatively new types of human-computer interaction interfaces in which users perceive and act in a 3D world. Researchers use it both as a tool and as an experimental area for their studies. In this study, a desktop VRE was created and used to explore the role of attention for visual perception of 60 university students who participated to the study. The findings showed that configurational knowledge can be attained in desktop VRE. Furthermore, it is found that visual attention has a significant role on forming cognitive maps since the incidental formation of a cognitive map seems to be not possible on the basis of our results

Technical Report: Distributed Parallel Computing Using Windows Desktop Systems

See also: http://sbml.org/Main_PageLike many large institutions, Indiana University has thousands of desktop computers devoted primarily to running office productivity applications on the Windows operating system, tasks which are necessary but that do not use the computers’ full capacity. This is a resource worth pursuing. However, the individual desktop systems do not offer enough processing power for a long enough period of time to complete large scientific computing applications. Some form of distributed, parallel programming is required, to make them worth the chase. They must be instantly available to their primary users, so they are available only intermittently. This has been a serious stumbling block: currently available communications libraries for distributed computing do not support such a dynamic communications world well. This paper introduces Simple Message Broker Library (SMBL), which provides the flexibility needed to take advantage of such ephemeral resources

Distant pointing in desktop collaborative virtual environments

Deictic pointing—pointing at things during conversations—is natural and ubiquitous in human communication. Deictic pointing is important in the real world; it is also important in collaborative virtual environments (CVEs) because CVEs are 3D virtual environments that resemble the real world. CVEs connect people from different locations, allowing them to communicate and collaborate remotely. However, the interaction and communication capabilities of CVEs are not as good as those in the real world. In CVEs, people interact with each other using avatars (the visual representations of users). One problem of avatars is that they are not expressive enough when compare to what we can do in the real world. In particular, deictic pointing has many limitations and is not well supported. This dissertation focuses on improving the expressiveness of distant pointing—where referents are out of reach—in desktop CVEs. This is done by developing a framework that guides the design and development of pointing techniques; by identifying important aspects of distant pointing through observation of how people point at distant referents in the real world; by designing, implementing, and evaluating distant-pointing techniques; and by providing a set of guidelines for the design of distant pointing in desktop CVEs. The evaluations of distant-pointing techniques examine whether pointing without extra visual effects (natural pointing) has sufficient accuracy; whether people can control free arm movement (free pointing) along with other avatar actions; and whether free and natural pointing are useful and valuable in desktop CVEs. Overall, this research provides better support for deictic pointing in CVEs by improving the expressiveness of distant pointing. With better pointing support, gestural communication can be more effective and can ultimately enhance the primary function of CVEs—supporting distributed collaboration

Adapting NASA\u27s MAPSS Databases to Desktop Computing

The capability of desktop computers has increased greatly over the past several decades, even outpacing some of the first supercomputers. A standard Intel i7-4790 processor can run at 90 Gigaflops. This means it can complete almost ten to the tenth operations per second. Hence, in a time when you can buy a new 8th generation intel processor for a few hundred dollars, an older 4th generation intel processor is more powerful than the most powerful computer in the world in 1993. In this research, we examine code developed for a NASA supercomputer and run it on a standard personal computer. Our results suggest that for simple tasks, such as pulling down information from the servers, the software is capable of running on a standard desktop. This demonstrates that when NASA produced code is adapted to a modern desktop computer, the computer can process the given information. In summary, we can show that modern desktop computers not only have more processing power than some of the first supercomputers, but can easily handle applications intended for processing large sums of data. From a larger perspective, this shows how computers evolved to the point where what is considered an outdated processors is still leagues above what was first produced. This material is based upon work supported by the National Aeronautics and Space Administration under Grant No. NNX15AK02H NASA Oklahoma Space Grant Consortium