58,794 research outputs found
Browsing through 3D representations of unstructured picture collections: an empirical study
The paper presents a 3D interactive representation of fairly large picture
collections which facilitates browsing through unstructured sets of icons or
pictures. Implementation of this representation implies choosing between two
visualization strategies: users may either manipulate the view (OV) or be
immersed in it (IV). The paper first presents this representation, then
describes an empirical study (17 participants) aimed at assessing the utility
and usability of each view. Subjective judgements in questionnaires and
debriefings were varied: 7 participants preferred the IV view, 4 the OV one,
and 6 could not choose between the two. Visual acuity and visual exploration
strategies seem to have exerted a greater influence on participants'
preferences than task performance or feeling of immersion.Comment: 4 page
A knowledge-based system design/information tool for aircraft flight control systems
Research aircraft have become increasingly dependent on advanced control systems to accomplish program goals. These aircraft are integrating multiple disciplines to improve performance and satisfy research objectives. This integration is being accomplished through electronic control systems. Because of the number of systems involved and the variety of engineering disciplines, systems design methods and information management have become essential to program success. The primary objective of the system design/information tool for aircraft flight control system is to help transfer flight control system design knowledge to the flight test community. By providing all of the design information and covering multiple disciplines in a structured, graphical manner, flight control systems can more easily be understood by the test engineers. This will provide the engineers with the information needed to thoroughly ground test the system and thereby reduce the likelihood of serious design errors surfacing in flight. The secondary objective is to apply structured design techniques to all of the design domains. By using the techniques in the top level system design down through the detailed hardware and software designs, it is hoped that fewer design anomalies will result. The flight test experiences of three highly complex, integrated aircraft programs are reviewed: the X-29 forward-swept wing, the advanced fighter technology integration (AFTI) F-16, and the highly maneuverable aircraft technology (HiMAT) program. Significant operating anomalies and the design errors which cause them, are examined to help identify what functions a system design/information tool should provide to assist designers in avoiding errors
Seamless and Secure VR: Adapting and Evaluating Established Authentication Systems for Virtual Reality
Virtual reality (VR) headsets are enabling a wide range of new
opportunities for the user. For example, in the near future users
may be able to visit virtual shopping malls and virtually join
international conferences. These and many other scenarios pose
new questions with regards to privacy and security, in particular
authentication of users within the virtual environment. As a first
step towards seamless VR authentication, this paper investigates
the direct transfer of well-established concepts (PIN, Android
unlock patterns) into VR. In a pilot study (N = 5) and a lab
study (N = 25), we adapted existing mechanisms and evaluated
their usability and security for VR. The results indicate that
both PINs and patterns are well suited for authentication in
VR. We found that the usability of both methods matched the
performance known from the physical world. In addition, the
private visual channel makes authentication harder to observe,
indicating that authentication in VR using traditional concepts
already achieves a good balance in the trade-off between usability
and security. The paper contributes to a better understanding of
authentication within VR environments, by providing the first
investigation of established authentication methods within VR,
and presents the base layer for the design of future authentication
schemes, which are used in VR environments only
Scientific Visualization Using the Flow Analysis Software Toolkit (FAST)
Over the past few years the Flow Analysis Software Toolkit (FAST) has matured into a useful tool for visualizing and analyzing scientific data on high-performance graphics workstations. Originally designed for visualizing the results of fluid dynamics research, FAST has demonstrated its flexibility by being used in several other areas of scientific research. These research areas include earth and space sciences, acid rain and ozone modelling, and automotive design, just to name a few. This paper describes the current status of FAST, including the basic concepts, architecture, existing functionality and features, and some of the known applications for which FAST is being used. A few of the applications, by both NASA and non-NASA agencies, are outlined in more detail. Described in the Outlines are the goals of each visualization project, the techniques or 'tricks' used lo produce the desired results, and custom modifications to FAST, if any, done to further enhance the analysis. Some of the future directions for FAST are also described
Animated computer graphics models of space and earth sciences data generated via the massively parallel processor
The capability was developed of rapidly producing visual representations of large, complex, multi-dimensional space and earth sciences data sets via the implementation of computer graphics modeling techniques on the Massively Parallel Processor (MPP) by employing techniques recently developed for typically non-scientific applications. Such capabilities can provide a new and valuable tool for the understanding of complex scientific data, and a new application of parallel computing via the MPP. A prototype system with such capabilities was developed and integrated into the National Space Science Data Center's (NSSDC) Pilot Climate Data System (PCDS) data-independent environment for computer graphics data display to provide easy access to users. While developing these capabilities, several problems had to be solved independently of the actual use of the MPP, all of which are outlined
EAGLEView: A surface and grid generation program and its data management
An old and proven grid generation code, the EAGLE grid generation package, is given an added dimension of a graphical interface and a real time data base manager. The Numerical Aerodynamic Simulation (NAS) Panel Library is used for the graphical user interface. Through the panels, EAGLEView constructs the EAGLE script command and sends it to EAGLE to be processed. After the object is created, the script is saved in a mini-buffer which can be edited and/or saved and reinterpreted. The graphical objects are set-up in a linked-list and can be selected or queried by pointing and clicking the mouse. The added graphical enhancement to the EAGLE system emphasizes the unique capability to construct field points around complex geometry and visualize the construction every step of the way
Diagnostic tools for 3D unstructured oceanographic data
Most ocean models in current use are built upon structured meshes. It follows
that most existing tools for extracting diagnostic quantities (volume and
surface integrals, for example) from ocean model output are constructed using
techniques and software tools which assume structured meshes. The greater
complexity inherent in unstructured meshes (especially fully unstructured grids
which are unstructured in the vertical as well as the horizontal direction) has
left some oceanographers, accustomed to traditional methods, unclear on how to
calculate diagnostics on these meshes. In this paper we show that tools for
extracting diagnostic data from the new generation of unstructured ocean models
can be constructed with relative ease using open source software. Higher level
languages such as Python, in conjunction with packages such as NumPy, SciPy,
VTK and MayaVi, provide many of the high-level primitives needed to perform 3D
visualisation and evaluate diagnostic quantities, e.g. density fluxes. We
demonstrate this in the particular case of calculating flux of vector fields
through isosurfaces, using flow data obtained from the unstructured mesh finite
element ocean code ICOM, however this tool can be applied to model output from
any unstructured grid ocean code
Structured computer-based training in the interpretation of neuroradiological images
Computer-based systems may be able to address a recognised need throughout the medical profession for a more structured approach to training. We describe a combined training system for neuroradiology, the MR Tutor that differs from previous approaches to computer-assisted training in radiology in that it provides case-based tuition whereby the system and user communicate in terms of a well-founded Image Description Language. The system implements a novel method of visualisation and interaction with a library of fully described cases utilising statistical models of similarity, typicality and disease categorisation of cases. We describe the rationale, knowledge representation and design of the system, and provide a formative evaluation of its usability and effectiveness
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