8,086 research outputs found
An empirical study of web interface design on small display devices
This paper reports an empirical study that explores the problem of finding a highly-efficient, user-friendly interface design method on small display devices. We compared three models using our PDA interface simulator: presentation optimization method, semantic conversion method, and zooming method. A controlled experiment has been carried out to identify the pros and cons of each method. The results show that of the three interface methods, the zooming method is slightly better than the semantic conversion method, while they both outperform the optimizing presentation method. © 2004 IEEE
Enabling collaboration in virtual reality navigators
In this paper we characterize a feature superset for Collaborative
Virtual Reality Environments (CVRE), and derive a component
framework to transform stand-alone VR navigators into full-fledged
multithreaded collaborative environments. The contributions of our
approach rely on a cost-effective and extensible technique for
loading software components into separate POSIX threads for
rendering, user interaction and network communications, and adding a
top layer for managing session collaboration. The framework recasts
a VR navigator under a distributed peer-to-peer topology for scene
and object sharing, using callback hooks for broadcasting remote
events and multicamera perspective sharing with avatar interaction.
We validate the framework by applying it to our own ALICE VR
Navigator. Experimental results show that our approach has good
performance in the collaborative inspection of complex models.Postprint (published version
Efficient Modeling of Hierarchical Dialog Flows for Multi-Channel Web Applications
In Web-based applications, most user interactions take the form of navigating between Web pages. The structure of the navigation model thus has a strong impact on a Web application's usability. However, specifying a user-friendly navigation model for complex applications can be time-consuming, especially when designing for multiple presentation channels. We therefore present the formal semantics of the dialog flow notation (DFN) that provides constructs for the design of modular navigation models, and especially focus on constructs that reduce the specification redundancy within and between channels, thus reducing the design effort for Web-based user interface
Technology for the Future: In-Space Technology Experiments Program, part 2
The purpose of the Office of Aeronautics and Space Technology (OAST) In-Space Technology Experiments Program In-STEP 1988 Workshop was to identify and prioritize technologies that are critical for future national space programs and require validation in the space environment, and review current NASA (In-Reach) and industry/ university (Out-Reach) experiments. A prioritized list of the critical technology needs was developed for the following eight disciplines: structures; environmental effects; power systems and thermal management; fluid management and propulsion systems; automation and robotics; sensors and information systems; in-space systems; and humans in space. This is part two of two parts and contains the critical technology presentations for the eight theme elements and a summary listing of critical space technology needs for each theme
Structured representation for requirements and specifications
This document was generated in support of NASA contract NAS1-18586, Design and Validation of Digital Flight Control Systems suitable for Fly-By-Wire Applications, Task Assignment 2. Task 2 is associated with a formal representation of requirements and specifications. In particular, this document contains results associated with the development of a Wide-Spectrum Requirements Specification Language (WSRSL) that can be used to express system requirements and specifications in both stylized and formal forms. Included with this development are prototype tools to support the specification language. In addition a preliminary requirements specification methodology based on the WSRSL has been developed. Lastly, the methodology has been applied to an Advanced Subsonic Civil Transport Flight Control System
Massive MIMO is a Reality -- What is Next? Five Promising Research Directions for Antenna Arrays
Massive MIMO (multiple-input multiple-output) is no longer a "wild" or
"promising" concept for future cellular networks - in 2018 it became a reality.
Base stations (BSs) with 64 fully digital transceiver chains were commercially
deployed in several countries, the key ingredients of Massive MIMO have made it
into the 5G standard, the signal processing methods required to achieve
unprecedented spectral efficiency have been developed, and the limitation due
to pilot contamination has been resolved. Even the development of fully digital
Massive MIMO arrays for mmWave frequencies - once viewed prohibitively
complicated and costly - is well underway. In a few years, Massive MIMO with
fully digital transceivers will be a mainstream feature at both sub-6 GHz and
mmWave frequencies. In this paper, we explain how the first chapter of the
Massive MIMO research saga has come to an end, while the story has just begun.
The coming wide-scale deployment of BSs with massive antenna arrays opens the
door to a brand new world where spatial processing capabilities are
omnipresent. In addition to mobile broadband services, the antennas can be used
for other communication applications, such as low-power machine-type or
ultra-reliable communications, as well as non-communication applications such
as radar, sensing and positioning. We outline five new Massive MIMO related
research directions: Extremely large aperture arrays, Holographic Massive MIMO,
Six-dimensional positioning, Large-scale MIMO radar, and Intelligent Massive
MIMO.Comment: 20 pages, 9 figures, submitted to Digital Signal Processin
Design and Implementation of Hierarchical Digital Twins in Industrial Production Environments
The increasing requirements for industrial production environments due to customer expectations, the implementation of batch size 1, and further automation of production processes are confronting companies with new challenges. In particular, the emergence of cyber-physical systems is influencing and complicating manufacturing processes by capturing an increasing amount of information within production facilities. Digital twins are an interdisciplinary technology that may solve these issues because they serve to monitor, control, and optimize cyber-physical systems by creating a digital representation of real-world objects. Existing concepts for digital twins usually consider specific and independent objects. This is of limited use for production environments due to a multitude of different machines and associated sensor types. Therefore, we propose a requirements catalog, concept, and prototypical implementation for the hierarchical structuring of digital twins in this paper
Data analysis and navigation in high-dimensional chemical and biological spaces
The goal of this master thesis is to develop and validate a visual data-mining
approach suitable for the screening of chemicals in the context of REACH [Registration, Evaluation, Authorization and
Restriction of Chemicals]. The
proposed approach will facilitate the development and validation of non-testing
methods via the exploration of environmental endpoints and their relationship with
the chemical structure and physicochemical properties of chemicals.
The use of an interactive chemical space data exploration tool using 3D visualization
and navigation will enrich the information available with additional variables like
size, texture and color of the objects of the scene (compounds). The features that
distinguish this approach and make it unique are (i) the integration of multiple data
sources allowing the recovery in real time of complementary information of the
studied compounds, (ii) the integration of several algorithms for the data analysis
(dimensional reduction, generation of composite variables and clustering) and (iii)
direct user interaction with the data through the virtual navigation mechanism. All
this is achieved without the need for specialized hardware or the use of specific
devices and high-cost virtual reality and mixed reality
NASA space station automation: AI-based technology review
Research and Development projects in automation for the Space Station are discussed. Artificial Intelligence (AI) based automation technologies are planned to enhance crew safety through reduced need for EVA, increase crew productivity through the reduction of routine operations, increase space station autonomy, and augment space station capability through the use of teleoperation and robotics. AI technology will also be developed for the servicing of satellites at the Space Station, system monitoring and diagnosis, space manufacturing, and the assembly of large space structures
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