Increasing usability when interacting through screen readers

The application of appropriate Web site design and evaluation methods helps to ensure more usable and accessible Web sites. While in the literature guidelines and evaluation methods for accessibility and usability are given and discussed separately, we aim at identifying the relationships between these two concepts, in particular considering usability criteria for accessible Web sites. In this work, we propose a set of such criteria targeted to improving the navigability for a specific group of disabled users, i.e., vision-impaired people. The identification of the eighteen criteria suggested herein was performed through empirical feedback, by which potential issues were identified. Subsequently, a systematic method was developed on the basis of the analysis of potential solutions, resulting in a classification of the criteria according to usability aspects. Some example applications of the proposed criteria to three existing public administration Web sites are discussed.     

Accessing information through multimodal 3D environments: towards universal access

3D environments represent a great opportunity for universal access to information, as they offer an intuitive interaction paradigm, similar to what is experienced by humans in their everyday lives. In spite of that, several 3D interfaces are characterized by poor structures and are hard to navigate. This paper presents the multimodal concept of the Interaction Locus (IL) as a means to give structure to 3D scenes, helping the user to interact with and access information inside them. The concept was initially developed with particular reference to desktop virtual reality (2.5 D virtual reality), but it is general enough to be extended to other contexts, such as real 3D scenes. The final part of this work shows how the IL concept addresses the need for a unified authoring methodology, capable of allowing access to different target user groups from a variety of different devices.     

Improving process models by discovering decision points

Workflow management systems (WfMS) are widely used by business enterprises as tools for administrating, automating and scheduling the business process activities with the available resources. Since the control flow specifications of workflows are manually designed, they entail assumptions and errors, leading to inaccurate workflow models. Decision points, the XOR nodes in a workflow graph model, determine the path chosen toward completion of any process invocation. In this work, we show that positioning the decision points at their earliest points can improve process efficiency by decreasing their uncertainties and identifying redundant activities. We present novel techniques to discover the earliest positions by analyzing workflow logs and to transform the model graph. The experimental results show that the transformed model is more efficient with respect to its average execution time and uncertainty, when compared to the original model.     

An Analytical Model to Measure the Effectiveness of Safety Management Systems: Global Safety Improve Risk Assessment (G-SIRA) Method

The ever-increasing complexity of production systems, together with the need to obtain efficient processes with limited costs, has led companies to develop custom tools for process control and management. Even for risk assessment, the traditional models often are overcome by methods that are best suited to specific needs. In this context, the aim of this paper was to propose a new model, which we call the global safety improve risk assessment (G-SIRA). This model can classify risks and identify corrective actions that allow the best risk reduction at the lowest cost. The proposed model, which is based on improvements to previous research, uses the analytic hierarchy process approach to develop a valid and simple tool for risk management. The G-SIRA method has been tested in a real-world application, i.e., it was applied to all of the processes of a textile company, and the results were compared with those obtained from the classical approach failure mode, effects, and criticality analysis. The comparison clearly showed the effectiveness of the proposed model.     

The attraction of contributors in free and open source software projects

As firms increasingly sanction an open sourcing strategy, the question of which open source project to undertake remains tentative. The lack of established metrics makes it difficult to formulate such strategy. While many projects have been formed and created, only a few managed to remain active. With the majority of these projects failing, firms need a reliable set of criteria to assess what makes a project appealing not only to developers but also to visitors, users and commercial sponsors. In this paper, we develop a theoretical model to explore the contextual and causal factors of project attractiveness in inducing activities such as source code contribution, software maintenance, and usage. We test our model with data derived from more than 4000 projects spanning 4 years. Our main findings include that projects’ set of conditions such as license restrictiveness and their available resources provide the context that directly influence the amount of work activities observed in the projects. It was also found that indirect and unintended contributions such as recommending software, despite of being non-technical, cannot be ignored for project activeness, diffusion and sustainability. Finally, our analysis provide evidence that higher attractiveness leads to more code-related activities with the downside of slowing down responsiveness to address projects’ tasks, such as the implementation of new features and bug fixes. Our model underscores the significance of the reinforcing effects of attractiveness and work activities in open source projects, giving us the opportunity to discuss strategies to manage common traps such as the liability of newness. We conclude by discussing the applicability of the research model to other user-led initiatives.     

Discrimination of vegetation types in alpine sites with ALOS PALSAR-, RADARSAT-2-, and lidar-derived information

Natural vegetation monitoring in the alpine mountain range is a priority in the European Union in view of climate change effects. Many potential monitoring tools, based on advanced remote sensing sensors, are still not fully integrated in operational activities, such as those exploiting very high-resolution synthetic aperture radar (SAR) or light detection and ranging (lidar) data. Their testing is important for possible incorporation in routine monitoring and to increase the quantity and quality of environmental information. In this study the potential of ALOS PALSAR and RADARSAT-2 SAR scenes' synergic use for discrimination of different vegetation types was tested in an alpine heterogeneous and fragmented landscape. The integration of a lidar-based canopy height model (CHM) with SAR data was also tested. A SPOT image was used as a benchmark to evaluate the results obtained with different input data. Discrimination of vegetation types was performed with maximum likelihood classification and neural networks. Six tested data combinations obtained more than 85% overall accuracy, and the most complex input which integrates the two SARs with lidar CHM outperformed the result based on SPOT. Neural network algorithms provided the best results. This study highlights the advantages of integrating SAR sensors with lidar CHM for vegetation monitoring in a changing environment.     

Using C/X-band SAR interferometry and GNSS measurements for the Assisi landslide analysis

This work presents an analysis of the applicability of synthetic aperture radar (SAR) interferometry to landslide monitoring. This analysis was carried out by using different interferometric approaches, different spaceborne SAR data (both in the C-band and in the X-band), and in situ global navigation satellite system (GNSS) measurements. In particular, we investigated both the reliability of displacement monitoring and the issues of the cross-comparison and validation of the interferometric synthetic aperture radar (InSAR) results. The work was focused on the slow-moving landslide that affects a relevant part of the urban area of the historical town of Assisi (Italy).

A C-band ENVISAT advanced synthetic aperture radar (ENVISAT ASAR) dataset acquired between 2003 and 2010 was processed by using two different interferometric techniques, to allow cross-comparison of the obtained displacement maps. Good correspondence between the results was found, and a deeper analysis of the movement field was possible. Results were further compared to a set of GNSS measurements with a 7 year overlap with SAR data. A comparison was made for each GNSS marker with the surrounding SAR scatterers, trying to take into account local topological effects, when possible.

Further, the high-resolution X-band acquired on both ascending and descending tracks by the COSMO-SkyMed (CSK) constellation was processed. The resultant displacement fields show good agreement with C-band and GNSS measurements and a sensible increase in the density of measurements.     

Learning optimal trajectories for non-holonomic systems

Many advanced robotic systems are subject to non-holonomic constraints, e.g. wheeled mobile robots, space manipulators and multifingered robot hands. Steering these mechanisms between configurations in the presence of perturbations is a difficult problem. In fact, the divide et impera strategy (first plan a trajectory, then track it by feedback) has a fundamental drawback in this case: due to the peculiar control properties of non-holonomic systems, smooth feedback cannot provide tracking of the whole trajectory. As a result, it would be necessary to give up either accuracy in the final positioning or predictability of the actual motion. We pursue here a different approach which does not rely on a separation between planning and control. Based on the learning control paradigm, a robust steering scheme is devised for systems which can be put in chained form, a canonical structure for non-holonomic systems. By overparametrizing the control law, other performance goals can be met, typically expressed as cost functions to be minimized along the trajectory. As a case study, we consider the generation of robust optimal trajectories for a car-like mobile robot, with criteria such as total length, maximum steering angle, distance from workspace obstacles, or error with respect to an offline planned trajectory.     

An integrated approach to hydrogen economy in Sicilian islands

CNR–ITAE is developing several hydrogen and fuel cell demonstration and research projects, each intended to be part of a larger strategy for hydrogen communities settling in small Sicilian islands. These projects involve vehicle design, hydrogen production from renewable energy sources and methane, as well as implementation strategies to develop a hydrogen and renewable energy economy. These zero emission lightweight vehicles feature regenerative braking and advanced power electronics to increase efficiency. Moreover, to achieve a very easy-to-use technology, a very simple interface between driver and the system is under development, including fault-recovery strategies and GPS positioning for car-rental fleets. Also marine applications have been included, with tests on PEFC applied on passenger ships and luxury yacht as power system for on-board loads. In marine application, it is under study also an electrolysis hydrogen generator system using seawater as hydrogen carrier. For stationary and automotive applications, the project includes a hydrogen refuelling station powered by renewable energy (wind or/and solar) and test on fuel processors fed with methane, in order to make the power generation self-sufficient, as well as to test the technology and increase public awareness toward clean energy sources.     

Synthesis of 8-hydroxyquinoline functionalised DO3A ligand and Eu(III) and Er(III) complexes: Luminescence properties

The synthesis of a new DO3A-based macrocyclic ligand bearing a 8-hydroxyquinoline residue together with the preparation of its Eu³⁺ and Er³⁺ neutral complexes are described. In a previous report [F. Rizzo, A. Papagni, F. Meinardi, R. Tubino, M. Ottonelli, G.F. Musso, G. Dellepiane, Synth. Met. 147 (2004) 143], we have shown that lanthanide complexes display very high stability combined with a good luminescence in aqueous solution under UV radiation, which indicate an energy transfer process from the excited 8-hydroxyquinoline moiety to the metal. In this work, we correlate the ability to transfer the energy from the sensitizer to lanthanide ion with pH behaviour of the antenna. Furthermore, the variation of pH in Eu³⁺ complex supports the hypothesis of presence of charge-transfer transitions. The good solubility and sensitized emission in different solvents (organic and water) are very important aspects for their technologic applications as luminescent probes or NIR-emitting devices.