Semantizing Complex 3D Scenes using Constrained Attribute Grammars

International audienceWe propose a new approach to automatically semantize complex objects in a 3D scene. For this, we define an expressive formalism combining the power of both attribute grammars and constraint. It offers a practical conceptual interface, which is crucial to write large maintainable specifications. As recursion is inadequate to express large collections of items, we introduce maximal operators, that are essential to reduce the parsing search space. Given a grammar in this formalism and a 3D scene, we show how to automatically compute a shared parse forest of all interpretations -- in practice, only a few, thanks to relevant constraints. We evaluate this technique for building model semantization using CAD model examples as well as photogrammetric and simulated LiDAR data

Grammar-Based Interactive Genome Visualization

Visualization is an indispensable method in the exploration of genomic data. However, the current state of the art in genome browsers – a class of interactive visualization tools – limit the exploration by coupling the visual representations with specific file formats. Because the tools do not support the exploration of the visualization design space, they are difficult to adapt to atypical data. Moreover, although the tools provide interactivity, the implementations are often rudimentary, encumbering the exploration of the data. This thesis introduces GenomeSpy, an interactive genome visualization tool that improves upon the current state of the art by providing better support for exploration. The tool uses a visualization grammar that allows for implementing novel visualization designs, which can display the underlying data more effectively. Moreover, the tool implements GPU-accelerated interactions that better support navigation in the genomic space. For instance, smoothly animated transitions between loci or sample sets improve the perception of causality and help the users stay in the flow of exploration. The expressivity of the visualization grammar and the benefit of fluid interactions are validated with two case studies. The case studies demonstrate visualization of high-grade serous ovarian cancer data at different analysis phases. First, GenomeSpy is being used to create a tool for scrutinizing raw copy-number variation data along with segmentation results. Second, the segmentations along with point mutations are used in a GenomeSpy-based multi-sample visualization that allows for exploring and comparing both multiple data dimensions and samples at the same time. Although the focus has been on cancer research, the tool could be applied to other domains as well

Challenges in Learning Unified Modeling Language: From the Perspective of Diagrammatic Representation and Reasoning

Unified modeling language (UML) is widely taught in the information systems (IS) curriculum. To understand UML in IS education, this paper reports on an empirical study that taps into students’ learning of UML. The study uses a concept-mapping technique to identify the challenges in learning UML notational elements. It reveals that some technical properties of UML diagrammatic representation, coupled with students’ cognitive attributes, hinder both perceptual and conceptual processes involved in searching, recognizing, and inferring visual information, which creates learning barriers. This paper also discusses how to facilitate perceptual and conceptual processes in instruction to overcome learning challenges. The study provides valuable insights for the IS educators, the UML academic community, and practitioners

Shape exploration in product design: assisting transformation in pictorial representations

The sketching of pictorial representations forms a key technique for professional designers in the generation and exploration of product shape. It allows ideas of shape to be externalised and communicated, but more importantly, sketched pictorial representations can operate to assist designers' creative thinking. While computer aided design tools have a proven capability to support the development of design ideas, there is still much scope to develop computer based tools that support the free-flowing exploratory thinking that characterises shape generation and shape exploration in product design. Far from being a straight-jacket in creative design, shape rules have significant potential to bridge the gap between traditional sketching techniques and modern computational methods of design. This thesis presents an inquiry into the exploitation of shape rules within product design. It includes studies of design sketches by professional designers and these inform the development of a theoretical model for assisting design transformation. A formal model of exploration is proposed with two mechanisms; shape decomposition and shape transformation. This model is applied using pictorial representations which may be seen as the computing equivalent of freehand sketches, and reveals new strategies for systematic shape generation and exploration in product design

Using Cognitive Maps of Mental Models to Evaluate Learning Challenges: A Case Study

Mental models are organized knowledge structures that individuals form to make sense of the world around them. Cognitive maps are the externalized portrayals of mental models in graphical format. Mental models and cognitive maps have been used as an instructional design method, an assessment tool, and a learning strategy in college education. In this paper, we propose a novel use of mental models and cognitive maps as a device to elicit students’ challenges in learning course materials. Our case study in an Information Systems class illustrates how cognitive maps are constructed from students’ mental models, how learning challenges are identified from cognitive maps, and how learning challenges can be coped with in teaching. Our proposed use of cognitive maps and mental models can provide educators with insights into the learning challenges from students’ perspectives, and help design instructional strategies for more effective teaching