Educational software and low vision students: evaluating accessibility factors

The aim of this paper is to draw a few guidelines for the evaluation of the accessibility and usability of educational software programs from the point of view of low vision students. The presented findings are based on the results of a long term research project carried out by the Italian National Research Council’s Institute for Educational Technology (ITD-CNR) and the David Chiossone Institute for the Blind, both based in Genoa, Italy. The educational project, whose general aims and results are not a matter of discussion here, involves a significant number of visually impaired students from primary to upper secondary school; in such a context, the researchers have the opportunity to assess and evaluate whether, and to what extent, the selected educational software products meet the needs of low vision students. In this perspective, the paper takes into account the features which can be considered significant from an educational point of view: general readability, working field extension and position, menu location and coherence, character dimension, colour brightness, etc. Bearing in mind the ultimate goal of providing children with appropriate, effective educational tools, an educational software accessibility checklist is proposed which is meant to be used by teachers with no, or scarce, experience of low vision, and not by professionals; it has already proved to be an effective tool for helping teachers select suitable educational software products “usable” by low vision students.

Selecting mutation operators with a multiobjective approach

The mutation score is an important measure to evaluate the quality of the test cases. It is obtained by executing a lot of mutant programs generated by a set of operators. A common problem, however, is that some operators can generate unnecessary and redundant mutants. Because of this, different strategies were proposed to find a set of operators that generates a reduced number of mutants without decreasing the mutation score. However, the operator selection, in practice, may include real constraints and is dependent on diverse factors besides the number of mutants and score, such as: number of test data, execution time, number of revealed faults, number of equivalent mutants, etc. In fact this is a multi-objective problem, which does not have a single solution. Different set of operators exist for multiple objectives to be satisfied, and some restrictions can be used to choose among the existing sets. To make this choice possible, in this paper, we introduce a multi-objective strategy. We investigate three multi-objective algorithms and introduce a procedure to establish a set of operators to prioritize mutation score. Better results are obtained in comparison with traditional strategies.     

Boosting modern and historical handwritten text recognition with deformable convolutions

International Journal on Document Analysis and Recognition (IJDAR) - Handwritten Text Recognition (HTR) in free-layout pages is a challenging image understanding task that can provide a relevant...     

Proteome analysis of biological fluids from autoimmune-rheumatological disorders

Autoimmune-rheumatological diseases are worldwide distributed disorders and represent a complex array of illnesses characterized by autoreactivity (reactivity against self-antigens) of T-B lymphocytes and by the synthesis of autoantibodies crucial for diagnosis (biomarkers). Yet, the effects of the autoimmune chronic inflammation on the infiltrated tissues and organs generally lead to profound tissue and organ damage with loss of function (i.e., lung, kidney, joints, exocrine glands). Although progresses have been made on the knowledge of these disorders, much still remains to be investigated on their pathogenesis and identification of new biomarkers useful in clinical practice. The rationale of using proteomics in autoimmune-rheumatological diseases has been the unmet need to collect, from biological fluids that are easily obtainable, a summary of the final biochemical events that represent the effects of the interplay between immune cells, mesenchymal cells and endothelial cells. Proteomic analysis of these fluids shows encouraging results and in this review, we addressed four major autoimmune-rheumatological diseases investigated through proteomic techniques and provide evidence-based data on the highlights obtained in systemic sclerosis, primary and secondary Sjogren's syndrome, systemic lupus erythematosus and rheumatoid arthritis.     

Validating a size measure for effort estimation in model-driven Web development

Web development is moving towards model-driven processes whose goal is the development of Web applications at a higher level of abstraction based on models and model transformations. This brings new opportunities to the Web project manager to make early estimates of the size and the effort required to produce Web applications based on their conceptual models. In the last few years, several studies for size and effort estimation have been performed. However, there are no studies regarding effort estimation in model-driven Web development. In this paper, we present the validation of a model-based size measure (OO-HFP) for Web effort estimation in the context of a model-driven Web development method. The validation is performed by comparing the prediction accuracy that OO-HFP provides with the accuracy provided by the standard function point analysis (FPA) method. The results of the study (using industrial data gathered from 31 Web projects) show that the effort estimates obtained for projects that are sized using OO-HFP are more accurate than the effort estimates obtained using the standard FPA method. This suggests that by following a model-driven development approach, the size measure obtained at the conceptual model of a Web application can be considered a suitable predictor of effort.     

Generating a catalog of unanticipated schemas in class hierarchies using Formal Concept Analysis

ContextInheritance is the cornerstone of object-oriented development, supporting conceptual modeling, subtype polymorphism and software reuse. But inheritance can be used in subtle ways that make complex systems hard to understand and extend, due to the presence of implicit dependencies in the inheritance hierarchy.ObjectiveAlthough these dependencies often specify well-known schemas (i.e., recurrent design or coding patterns, such as hook and template methods), new unanticipated dependency schemas arise in practice, and can consequently be hard to recognize and detect. Thus, a developer making changes or extensions to an object-oriented system needs to understand these implicit contracts defined by the dependencies between a class and its subclasses, or risk that seemingly innocuous changes break them.MethodTo tackle this problem, we have developed an approach based on Formal Concept Analysis. Our Formal Concept Analysis based-Reverse Engineering methodology (FoCARE) identifies undocumented hierarchical dependencies in a hierarchy by taking into account the existing structure and behavior of classes and subclasses.ResultsWe validate our approach by applying it to a large and non-trivial case study, yielding a catalog of hierarchy schemas, each one composed of a set of dependencies over methods and attributes in a class hierarchy. We show how the discovered dependency schemas can be used not only to identify good design practices, but also to expose bad smells in design, thereby helping developers in initial reengineering phases to develop a first mental model of a system. Although some of the identified schemas are already documented in existing literature, with our approach based on Formal Concept Analysis (FCA), we are also able to identify previously unidentified schemas.ConclusionsFCA is an effective tool because it is an ideal classification mining tool to identify commonalities between software artifacts, and usually these commonalities reveal known and unknown characteristics of the software artifacts. We also show that once a catalog of useful schemas stabilizes after several runs of FoCARE, the added cost of FCA is no longer needed.     

Plantwide Optimizing Control of a continuous bioethanol production process

In this work, the Plantwide Control (PWC) problem of a continuous bioethanol process is investigated from a Plantwide Optimizing Control (PWOC) perspective. PWOC addresses the plantwide control problem integrating real-time optimization and control for optimal operation. Two different PWOC approaches have been considered: a single-layer direct optimizing control approach (one-layer) and a multi-layer without coordination approach (two-layer). The performance of these two PWOC schemes is compared with more conventional decentralized architectures, demonstrating the benefits of using plantwide optimization-based control strategies in the bioethanol process, towards reaching maximum profitability.     

Graph-based representations of point clouds

This paper introduces a skeletal representation, called Point Cloud Graph, that generalizes the definition of the Reeb graph to arbitrary point clouds sampled from m-dimensional manifolds embedded in the d-dimensional space. The proposed algorithm is easy to implement and the graph representation yields to an effective abstraction of the data. Finally, we present experimental results on point-sampled surfaces and volumetric data that show the robustness of the Point Cloud Graph to non-uniform point distributions and its usefulness for shape comparison.     

Modeling the forensic two-trace problem with Bayesian networks

The forensic two-trace problem is a perplexing inference problem introduced by Evett (J Forensic Sci Soc 27:375–381, 1987). Different possible ways of wording the competing pair of propositions (i.e., one proposition advanced by the prosecution and one proposition advanced by the defence) led to different quantifications of the value of the evidence (Meester and Sjerps in Biometrics 59:727–732, 2003). Here, we re-examine this scenario with the aim of clarifying the interrelationships that exist between the different solutions, and in this way, produce a global vision of the problem. We propose to investigate the different expressions for evaluating the value of the evidence by using a graphical approach, i.e. Bayesian networks, to model the rationale behind each of the proposed solutions and the assumptions made on the unknown parameters in this problem.     

Analysis of recent ground subsidence in the Sibari plain (Italy) by means of satellite SAR interferometry-based methods

This work attempts to map recent land subsidence on the Sibari plain in Calabria region (Southern Italy), by exploiting vertical velocity values and time series of persistent scatterer interferometry (PSI) synthetic aperture radar (SAR) data acquired in the period 1992–2011 by different satellite systems.

After reviewing other sources and rates of subsidence recorded by previous works since the beginning of the Holocene, this paper presents the spatial distribution of the current settlement rates showing that subsidence is due to the compressible alluvial sediments of the plain, but that in recent times it is mostly due also to human activities. In fact, according to the most recent monitoring period (2009–2011), downward motion rates are recorded as being only localized within site-specific industrial areas, such as the ‘Sibari Lakes’ nautical and residential centre and Corigliano Calabro Industrial Zone. The temporal analysis of persistent scatterers (PS) time series, carried out through the PS-Time program, adds further useful information, finally highlighting that, in these areas, subsidence has positively decreased or stabilized from the second semester of the year 2010.

This work shows that PSI measurements provide support in the quantitative evaluation of known subsidence process and that the analysis of time series allows effective detection of the temporal evolution trends of the phenomenon, such as changes or deceleration in displacement rates, not otherwise visible by merely considering the average velocity.