Abstract
This paper proposes a roadmap to integrate existing educational web applications into the ecosystem based on a learning management system. To achieve this integration, applications must support the Learning Tools Interoperability specification in the role of tool provider. The paper starts with an overview of the evolution of this specification, emphasizing the main features of the current stable version. Then, it proposes a set of design goals and milestones to guide the adaptation process. The proposed roadmap was validated with existing applications. This paper reports on the challenges faced to apply it in these concrete cases. © Leal, Jose Paulo; Queirs, Ricardo; Ferreirinha, Pedro; Swacha, Jakub; licensed under Creative Commons License CC-BY 4.0

Abstract
We propose an approach to summarize large semantics graphs using namespaces. Semantic graphs based on the Resource Description Framework (RDF) use namespaces on their serializations. Although these namespaces are not part of RDF semantics, they have intrinsic meaning. Based on this insight, we use namespaces to create summary graphs of reduced size, more amenable to be visualized. In the summarization, object literals are also reduced to their data type and the blank nodes to a group of their own. The visualization created for the summary graph aims to give insight of the original large graph. This paper describes the proposed approach and reports on the results obtained with representative large semantic graphs. © Ana Rita Santos Lopes da Costa, André Santos, and José Paulo Leal.

Abstract
This paper describes ongoing research to develop a system to automatically generate exercises on document type validation. It aims to support multiple text-based document formalisms, currently including JSON and XML. Validation of JSON documents uses JSON Schema and validation of XML uses both XML Schema and DTD. The exercise generator receives as input a document type and produces two sets of documents: valid and invalid instances. Document types written by students must validate the former and invalidate the latter. Exercises produced by this generator can be automatically accessed in a state-of-the-art assessment system. This paper details the proposed approach and describes the design of the system currently being implemented. © José Paulo Leal, Ricardo Queirós, and Marco Primo.

Abstract
The work presented in this article is part of ongoing research on the automated assessment of simple web applications. The proposed algorithm compares two interfaces by mapping their elements, using properties to identify those with the same role in both interfaces. The algorithm proceeds in three stages: firstly, it selects the relevant elements from both interfaces; secondly, it refines elements' attributes, excluding some and computing new ones; finally, it matches elements based on attribute similitude. The article includes an experiment to validate the algorithm as an assessment tool. As part of this experiment, a set of experts classified multiple web interfaces. Statistical analysis found a significant correlation between classifications made by the algorithm and those made by experts. The article also discusses the exploitation of the algorithm's output to access both the layout and functionality of a web interface and produce feedback messages in an automated assessment environment, which is planned as future research.

Abstract

Abstract
A key aspect of any hash map design is the problem of dynamically resizing it in order to deal with hash collisions. Compression in tree-based hash maps is the ability of reducing the depth of the internal hash levels that support the hash map. In this context, elasticity refers to the ability of automatically resizing the internal data structures that support the hash map operations in order to meet varying workloads, thus optimizing the overall memory consumption of the hash map. This work extends a previous lock-free hash trie map design to support elastic hashing, i.e., expand saturated hash levels and compress unused hash levels, such that, at each point in time, the number of levels in a path is adjusted, as closely as possible, to the set of keys that is stored in the data structure. To materialize our design, we introduce a new compress operation for hash levels, which requires redesigning the existing search, insert, remove and expand operations in order to maintain the lock-freedom property of the data structure. Experimental results show that elasticity effectively improves the search operation and, in doing so, our design becomes very competitive when compared to other state-of-the-art designs implemented in Java.