We present BlobMaker, a program for modelling surfaces using variational implicit surfaces Our approach uses variational implicit surfaces as a geometrical representation for free-form shapes We have implemented new modelling operations to support stroke (pen-based) input To this end, we have built a complete modeller application using variational implicit surfaces Users can create and manipulate shapes using sketches on a perspective or parallel view The main operations are inflate, which creates 3D forms from a 2D stroke, merge, which creates a 3D shape from two blobs and oversketch, which allows users to redefine shapes using a single stroke to change their boundaries or to modify a surface by an implicit extrusion We compare these techniques with those of other approaches published Finally, we describe their implementation in BlobMaker We have provided additional features such as copying, picking and dragging to offer a natural user interface suitable for free-form modelling

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BlobMaker: Free-Form Modelling with Variational Implicit Surfaces

Usability is a key attribute affecting information technology systems acceptance and adoption by users in instructional settings. This is due to the system’s role as communication mediator between instructors and learners. Indeed, a basic condition for usable e-learning systems is that users are able to concentrate on content and not on system issues. This demands an integrated, systematic and user-based evaluation approach to help designing learning-centered experiences. However, usability in educational support systems is also affected by contextual factors. Thus, methods that address both the technical and pedagogical dimensions in context of use are still a research issue. These methods will help organizations who want to remain competitive, identify which factors are the most important when adopting technologysupported learning solutions while gradually evolving towards an effective learning process. In this paper, we describe an integrated usability evaluation method empirically tested within an instructional setting in our university. We developed a system prototype to support the internal teaching process and evaluated its role in a technology-supported learning experience. Our results indicate that an e-learning system must adequately meet the needs of the instructional process and support learners’ behaviors and actions. These results also show that consistent online and offline communication between stakeholders is crucial to achieve learning effectiveness. While describing ongoing research, we expect that this contribution will provide insights and better understanding on how to evaluate and improve e-learning systems’ usability based on learners’ feedback and usage patterns.

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Evaluating learning support systems usability an empirical approach

Despite of decades of research, creating intuitive and easy to learn interfaces for 3D virtual environments (VE) is still not obvious, requiring VE specialists to define, implement and evaluate solutions in an iterative way, often using low-level programming code. Moreover, quite frequently the interaction with the virtual environment may also vary dependent on the context in which it is applied, such as the available hardware setup, user experience, or the pose of the user (e.g. sitting or standing). Lacking other tools, the context-awareness of an application is usually implemented in an ad-hoc manner, using low-level programming, as well. This may result in code that is difficult and expensive to maintain. One possible approach to facilitate the process of creating these highly interactive user interfaces is by adopting a model-based user interface design. This lifts the creation of a user interface to a higher level allowing the designer to reason more in terms of high-level concepts, rather than writing programming code. In this paper, we adopt a model-based user interface design (MBUID) process for the creation of VEs, and explain how a context system using an Event-Condition-Action paradigm is added. We illustrate our approach by means of a case study.

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Designing context-aware multimodal virtual environments

i*Chameleon is a multimodal interaction framework that enables programmers to readily prototype and test new interactive devices or interaction modes. It allows users to customize their own desktop environment for interaction beyond the usual KVM devices, which would be particularly useful for users with difficulty using the keyboard and mouse, or for systems deployed in specialized environments. This is made possible with the engineering of an interaction framework that distills the complexity of control processing to a set of semantically-rich modal controls that are discoverable, composable and adaptable. The framework can also be used for developing new applications with multimodal interactions, for example, distributed applications in collaborative environments or robot control.

i*Chameleon: a scalable and extensible framework for multimodal interaction

In this paper, we describe adPD, an improved parallel downloading approach to retrieving files by estab- lishing parallel connections with multiple copies. adPD assigns each server equal portion of file as large as possible, which ensures client downloading from each server without interrupt. And after faster server finish its own work, ad- PD will reallocate part of unfinished work of some slower server to the faster server. By this means, adPD can dynam- ically adjust the proportion of a file retrieved from each server during the downloading process, and can also reduce the number of block requests. Experiment results show that adPD is an effective parallel download scheme especially in Peer-to-Peer environments. Our experiment results show that adPD is an effective parallel download scheme.

A Speed-Based Adaptive Dynamic Parallel Downloading Technique

We present a framework to manage multimodal applications and interfaces in a reusable and extensible manner. We achieve this by focusing the architecture both on applications' needs and devices' capabilities. One particular domain we want to approach is collaborative environments where several modalities and applications make it necessary to provide for an extensible system combining diverse components across heterogeneous platforms on-the-fly. This paper describes the proposed framework and its main contributions in the context of an architectural application scenario. We demonstrate how to connect different non-conventional applications and input modalities around an immersive environment (tiled display wall).

Extensible middleware framework for multimodal interfaces in distributed environments

This article presents work done at the Technical University of Lisbon, on web systems to support technology-enhanced learning. Based on eighteen months experience with webcast technologies and commonly used Learning Management Systems, this work has integrated both concepts and developed a simple, yet effective learning approach. This approach supports both students and professors in moving from the traditional classroom to technology-enhanced online settings. We present the evolution of our system and the results obtained from testing and evaluating the prototype, during the last Spring semester. One of the major features of our approach lies in combining both online and offline components of the eLearning experience and incorporating desirable traits from traditional and technology-mediated learning. This way, we have identified significant issues for users in order to better manage the changes required to adapt our system to organizational processes and context of use. Our assessment points to changes in the teaching method, course organization, and highlights new factors of students’ motivation. Results, however preliminary, seem to indicate both the usefulness of our approach and the feasibility of deploying e-learning initiatives with efforts optimization to complement traditional offerings in university settings.

Vitor Fernandes

Papers

Extensible middleware framework for multimodal interfaces in distributed environments

Web-based support for resource-effective e-learning

Online Communication in a Multimedia Course