59314649
Adapting the Cognitive Walkthrough Method to Assess the Usability of a Knowledge Domain Visualization
45076304
Spatial Semantic Virtual Worlds: The Structural Duality and Beyond
206109439
How did university departments interweave the Web: A study of connectivity and underlying factors
This paper presents two studies of the use of the WWW in Scottish universities and American land-grant universities. First, we investigated the relationship between the organisational profile of a university department in Scotland and its structural connectivity on the WWW. A Spearman rank order correlation analysis revealed a number of strong correlation relationships between structural connectivity measures and the organisational profile based on research assessment exercise ratings, teaching quality assessments, student‐staff ratios and funding levels. Linkage patterns from 13 Scottish academic sites to commercial sites in Britain and America highlighted the impact of culture and the appropriateness of information technologies on the acceptance of the WWW. The second study is a content survey of WWW-based education activities in American land-grant universities to investigate successful applications of these enabling techniques in education. The two studies together highlighted cultural, political and technological interactions in the use of the WWW. q 1998 Elsevier Science B.V. All rights reserved
468820
Tracing knowledge diffusion
Knowledge diffusion is the adaptation of knowledge in a broad range of scientific and engineering research and development. Tracing knowledge diffusion between science and technology is a challenging issue due to the complexity of identifying emerging patterns in a diverse range of possible processes. In this article, we describe an approach that combines complex network theory, network visualization, and patent citation analysis in order to improve the means for the study of knowledge diffusion. In particular, we analyze patent citations in the field of tissue engineering. We emphasize that this is the beginning of a longer-term endeavor that aims to develop and deploy effective, progressive, and explanatory visualization techniques for us to capture the dynamics of the evolution of patent citation networks. The work has practical implications on resource allocation, strategic planning, and science policy.
46129433
Behavioural Patterns of Collaborative Writing with Hypertext - A State Transition Approach
This study investigates behavioural patterns of collaborative writing with a hypertext system by using a state-transition approach. State-transition models are empirically developed for capturing the dynamic nature of collaborative writing. Users were frequently engaged in tasks such as exploration, organization, and editing, whereas the use of collaborative support functions was transient in nature. The study shows that state-transition analysis is an important approach to task analysis, requirements engineering, and human-computer interaction studies. This study has produced some valuable experiences and lessons for researchers and practitioners in collaborative writing.
15424500
Semantically modified diffusion limited aggregation for visualizing large-scale networks
Diffusion-limited aggregation (DLA) is a model of fractal growth. Computer models can simulate the fast aggregation of millions of particles. We propose a modified version of DLA, called semantically modified DLA (SM-DLA), for visualizing large-scale networks. SM-DLA introduces similarity measures between particles so that instead of attaching to the nearest particle in the aggregation, a new particle is stochastically directed to attach to particles that are similar to it. The results of our initial experiment with a co-citation network using SM-DLA are encouraging, suggesting that the algorithm has the potential as an alternative paradigm for visualizing large-scale networks. Further studies in this direction are recommended.
27757598
Assessing the effectiveness of online asynchronous case method
This paper reports a field experiment that evaluates the use of the case method in an online asynchronous learning (OAL) environment. Our findings suggest that OAL should be used to promote students' participation, rather than cognitive learning gains. Teaching the case method in F2F environment can help learners achieve higher cognitive learning gains.
6983146
On Digital Mammogram Segmentation and Microcalcification Detection Using Multiresolution Wavelet Analysis
In this paper a multiresolution wavelet analysis (MWA) and nonstationary Gaussian Markov random field (GMRF) technique is introduced for the detection of microcalcifications with high accuracy. The hierarchical multiresolution wavelet information in conjunction with the contextual information of the images extracted from GMRF provides an efficient technique for microcalcification detection. A Bayesian learning paradigm realized via the expectation maximization (EM) algorithm was also introduced for edge detection or segmentation of mass regions recorded on the mammograms. The strength of the technique is in the effective utilization of the rich contextural information in the images considered. The effectiveness of the approach has been tested with a number of mammographic images for which the microcalcification detection algorithm achieved a sensitivity (true positive rate) of 94% and specificity (true negative rate) of 88%. Considerably good results were also obtained for the segmentation algorithm. In addition, the results for both the detected microcalcifications and the segmented mass regions were superimposed for an interesting case under the methods introduced.
14818835
An empirical evaluation of several methods to select the best system
Simulation is an important tool for comparing the performance of several alternative systems. There is therefore significant interest in procedures that efficiently select the best system, where best is defined by the maximum or minimum expected simulation output. In this paper, we examine both two-stage and sequential procedures that represent three structurally different modeling methodologies for allocating simulation replications to identify the best system, and we evaluate them empirically with respect to several measures of effectiveness. Empirical evidence suggests that sequential procedures perform better than their two-stage counterparts, including a heuristic sequential variation on Rinott's procedure. Further, there appears to be significant benefit to using procedures based on a Bayesian, average-case analysis as opposed to the statistically-conservative indifference-zone formulation.
29297649
Shape from Photometric Stereo and Contours
In this work, we propose an alternative approach to 3D shape recovery by combining photometric stereo and shape from contours methods. Surfaces recovered by photometric stereo are aligned, adjusted and merged according to a preliminary 3D model obtained by shape from contours. Comparisons are conducted to evaluate the performances of different methods. It has been found that the proposed approach provides more accurate shape recovery than the photometric stereo and shape from contours methods.
15344875
Albedo recovery using a photometric stereo approach
This paper describes a method for the estimation of surface reflectance values using a photometric stereo approach. Evaluations show that surfaces rendered with reflectance values calculated by the proposed method have more realistic appearances than those with constant albedo.