Abstract

Abstract
3D interface devices are being announced as rendering virtual world navigation easier. We have prepared a usability testing framework for two such devices, SpaceNavigator and SpacePilot PRO, manufactured by 3Dconnexion. The paper summarizes the underlying concepts of usability testing and links them to the requirements of a virtual world 3D interface context. We detail the metrics to be employed and the reasoning behind their selection, and the planning which yielded the actual framework to be used for conducting the 3D interface usability tests in the Second Life virtual world. © 2011 IEEE.

Abstract

Abstract
Many military training centers still use traditional means to train and practice air traffic control. To represent reality, they use physical models of an airfield and aircrafts, or advanced computer simulations. LMS systems are also frequently used for management of online contents of courses. We are connecting simulations with LMS systems, in order to support trainers' tracking of trainees' progress. This paper presents a technological architecture that allows a trainee to use a virtual air traffic control (ATC) simulator to practice exercises available at the LMS and updates the LMS with the trainee's progress and actions within the simulator. It also presents details of a first approach to the implementation of this architecture. © 2011 IEEE.

Abstract
In the past, several approaches have been devised to semi- automate the multidimensional design (MDD) of Data Warehouse (DW) projects. Such approaches highly contribute to more expertise- independent and deterministic MDD results. Among them, only the Dimensional Templates Approach (DTA) focuses on solving the critical resource containment problems of DW prototypes. Originally, the DTA allows solely the generation of basic MDDs. In this paper, we depict an extension to address complex MDD issues. These include (i) date/time hierarchies, (ii) many-to-many relationships, (iii) hierarchically structured data and (iv) coverage facts. The proposed enhancements, including a rebuilt generation algorithm, allow more accurate and broadening results than the original DTA. Throughout the paper, references are made to a real case study to which the improved DTA has been applied using two developed prototype tools. © 2011 Springer-Verlag.

Abstract
This study presents a method to measure the displacement fields on the surface of planar objects with sub-pixel resolution, by combining image correlation with a differential technique. First, a coarse approximation of the pixel level displacement is obtained by cross-correlation (CC). Two consecutive images, taken before and after the application of a given deformation, are recursively split in sub-images, and the CC coefficient is used as the similarity measure. Secondly, a fine approximation is performed to assess the sub-pixel displacements by means of an optical flow method based on a differential technique. To validate the effectiveness and robustness of the proposed method, several numerical tests were carried out on computer-generated images. Moreover, real images from a static test were also processed for estimating the displacement resolution. The results were compared with those obtained by a commercial digital image correlation code. Both methods showed similar and reliable results according to the proposed tests.