17022793
Biomedical computing and visualization software environments
Problem-solving environments and advanced visualization take on the complexity of biomedical computing, improving its utility to scientists and clinicians alike.
8344660
Top Scientific Visualization Research Problems
Scientific visualization as currently understood and practiced is still a relatively new discipline. As a result, we visualization researches are not necessarily accustomed to undertaking the sorts of self-examinations that other scientists routinely undergo in relation to their work. Yet if we are to creat a disciplinary culture focused on matters of real scientific importance and committed to real progress, it is essential that we ask ourselves hard questions on an ongoing basis. What are the most important research issues facing us? What underlying assumptions needs to be challenged and perhaps abandoned? What practices need to be reviewed? In this article, I attempt to start a discussion of these issues by proposing a list of top research problems and issues in scientific visualization.
15670
Display of vector fields using a reaction-diffusion model
Effective visualization of vector fields relies on the ability to control the size and density of the underlying mapping to visual cues used to represent the field. In this paper we introduce the use of a reaction-diffusion model, already well known for its ability to form irregular spatio-temporal patters, to control the size, density, and placement of the vector field representation. We demonstrate that it is possible to encode vector field information (orientation and magnitude) into the parameters governing a reaction-diffusion model to form a spot pattern with the correct orientation, size, and density, creating an effective visualization. To encode direction we texture the spots using a light to dark fading texture. We also show that it is possible to use the reaction-diffusion model to visualize an additional scalar value, such as the uncertainty in the orientation of the vector field. An additional benefit of the reaction-diffusion visualization technique arises from its automatic density distribution. This benefit suggests using the technique to augment other vector visualization techniques. We demonstrate this utility by augmenting a LIC visualization with a reaction-diffusion visualization. Finally, the reaction-diffusion visualization method provides a technique that can be used for streamline and glyph placement.
28212389
Biomedical computing and visualization
21779382
Computational Engineering and Science Program at the University of Utah
We describe a new graduate program at the Univesity of Utah that we consider a first step towards the modernization of the University's curriculum in what we call "Computational Engineering and Science" (CES). Our goal is to provide a mechanism by which a graduate student can obtain integrated expertise and skills in all areas that are required for the solution of a particular computational problem.
47143488
The Evaluation of User Interface Notations
Over the last decade a wide range of graphical, tabular and textual notations have been proposed to support the design of human-computer interfaces. These notations are intended to strip away the clutter of implementation details that frequently obscure interaction properties. Unfortunately, relatively little work has been done to evaluate the usability of these notations for ‘real-world’ interfaces. We have, therefore, conducted an empirical evaluation of the User Action Notation (UAN), State Transition Networks (STN) and temporal logic ‘in the wild’. By this we mean that our subjects were drawn from realistic samples of users and designers. We also presented our subjects with realistic descriptions of two user interfaces. This avoids a weakness of previous investigations that have used ‘toy examples’. The results of our investigation show a strong preference amongst our subjects for the use of natural language descriptions. More surprisingly, our results also suggest a link between the frequency of comprehension errors and positive attitude statements towards particular notations. In other words, our subjects made most errors with the notations that they liked the best. This suggests that while graphical notations, such as state transition networks, have a strong intuitive appeal they may also create significant problems for real-world development tasks.
10158972
On the Problems of Validating DesktopVR
For the last twenty years, human-computer interfaces have been dominated by two-dimensional interaction techniques. Things are changing. Techniques that were previously restricted to specialized CAD/CAM tools and immersive VR systems are now being extended to the mass market. The photo-realistic facilities offered by QuicktimeVR and the model based renderings of VRML (Virtual Reality Mark-up Language) provide sophisticated tools for interface design. As a result, three dimensional visualization techniques are being widely exploited in the financial services industry, airports and even off-shore oil production. In January 1997, there were some 2,000 VRML models on the web. By January 1998, this number had grown to over 20,000. Research in human-computer interaction has, however, lagged behind these developments. Few guidelines can be applied to support the design of desktopVR. This paper, therefore, describes three criteria that can be applied to assess the usability of these interfaces. We then go on to validate these criteria against a number of case studies. Unfortunately, it is concluded that standard measures of task performance, successful navigation and subjective satisfaction cannot easily be applied to assess the utility of 3D systems.
9129216
A formal and structured approach to the use of task analysis in accident modelling
Recent work (Telford & Johnson, 1996; Johnson, 1997), involving the application of formal notations to analyse accident reports has shown that the quality of these accident reports is poor, so much so that their conclusions can be misleading. The proposed solution has been to use formal notations in combination with traditional analysis to produce a report, the conclusions of which can be verified by formal reasoning. However, there are weaknesses with the formal notations used up until now. Firstly, they have not allowed the representation of all aspects of an accident or incident. For example, human factors have either not been represented or not clearly delineated from system factors. In particular, there has not been an attempt to provide a task analysis of the incident. Secondly, the notations used do not easily facilitate the system engineering concepts of modularity, encapsulation or scalability. In consequence, it is difficult to model different aspects of an accident, compose these different aspects to build up the model or make changes to parts of the model without affecting the rest of the model. The purpose of this paper is to demonstrate how a formal object-oriented specification language can be used to provide the benefits offered by an engineering approach and in particular, by using this approach, how a task analysis model can be constructed. The task analysis incorporates Hollnagel's (1993) classification of erroneous actions, so that scenarios, deriving from human error, can be reasoned about. An air accident investigation report, issued by the UK Civil Aviation Authority, is used as a case study.
35998651
Artificial Immune System Programming for Symbolic Regression
Artificial Immune Systems are computational algorithms which take their inspiration from the way in which natural immune systems learn to respond to attacks on an organism. This paper discusses how such a system can be used as an alternative to genetic algorithms as a way of exploring program-space in a system similar to genetic programming. Some experimental results are given for a symbolic regression problem. The paper ends with a discussion of future directions for the use of artificial immune systems in program induction.
18085576
Semantic errors - diagnosis and repair
In compiler technology, semantic error handling has too often used ad hoc techniques and terse messages of fixed content. In contrast, we present general models of diagnosis and repair of semantic errors and illustrate their use in the York Ada Workbench Compiler. The diagnostic model focuses upon the problem of selecting suitable information from which the programmer can locate and correct an error; following a brief discussion of an approach in which <underline>filters</underline> are applied to reports, and we give a more extensive account of a new approach using an <underline>interactive diagnostic interpreter</underline>. The repair model is based upon the idea of <underline>plastic</underline> nodes which are introduced into the compiler's internal representation of a program to replace <underline>normal</underline> nodes which are missing or erroneous.