Donato Pirozzi

Support Citizens in Visualising Open Data.

This paper contributes in the field of Open Data and their visualisations, trying to reduce the gap between the public institutions (who publish Open Data) and citizens, providing awareness of data quality and supporting them during the process of chart creation. Proposed solution syntactically analyses the datasets values to infer its data types and continually shows a list of chart visualisations compatible with the selected dataset and its fields. Instead to start with a catalogue containing all available charts, the system reduces the space of charts proposing any time only those that are compatible. In addition, a well-known barrier in the use of Open Data is the poor quality of the available datasets, thus, this paper proposes two quality indexes to provide at glance awareness of the dataset quality. This provides a quantitative measurement to dataset publishers (e.g., public institutions), who can evaluate the data quality, and also the citizens, who can ask for better open datasets providing a reason for such request.

Spherule diagrams with graph for social network visualization

As social network information keeps growing, there is always a need for better information visualization techniques for carrying out multifarious analysis, which is commonly called as social network analysis. Social networks have become a big platform for advertisements, where a company targets highly connected than to more isolated users. To target highly connected users and their activities, visualizations such as Euler diagrams, Treemap diagrams, graphs and their combinations were tested by various researchers. Though Euler diagrams combined with graph and Treemap diagrams with graph have provided some interesting results, the one question yet to be answered is the scalability. In this paper, we propose a novel visual technique, “Spherule diagrams with graph”, which addresses the scalability issue. The novel technique is then compared with the traditional Euler diagrams with graph using a twitter case study in an empirical form. Twenty-eight participants were exposed to eighteen diagrams (nine diagrams of each type of visualization) in a software which recorded accuracy and response time (i.e., performance measure). The results of 504 observations indicate that (a) there is no significant difference between the visualizations in terms of accuracy and (b) there is a significant difference between the visualizations in terms of response time. Also, users were asked to aggrandize between the two visualizations (i.e., preference measure), where 75% preferred Spherule diagrams with graph for its simplicity, comprehensiveness, navigation, alignment (layout), set ordering and data items ordering characteristics. We conclude that, Spherule diagrams with graph will be beneficial for researchers and practitioners in the information visualization community who are exploring social networks for business.

Simulation repository visualisation and exploration

This paper describes a tool called ExploraTool to visualise, explore and graphically query large repositories of simulations. Instead of starting with the empty list, ExploraTool provides an initial overview of the repository content, progressively grouping the simulations by their main attributes, such as brand, vehicle model, power source, engine type and so on. Users can interactively navigate the repository view through drill-down, roll-up and rearrangement operations. In this way, using the ExploraTool, simulation analysts can visualise, explore and filter large repository of simulations as well as select groups of simulations to compare their performances.

An architecture for CFD Workflow management

Nowadays, to design product impacted by fluid flow, industries use Computational Fluid Dynamics (CFD) to get a better insight into product behaviour. In this paper, we present a system architecture design for CFD Workflow management.

Social network visualization: Does partial edges affect user comprehension?

In a small-world resolution, Euler diagrams are tangentially augmented with graphs and are realized in social network analysis but one of the main issue is the visual clutter. One interesting way of reducing this clutter is to use partial edges when there are visual elements (edge and curve) crossings. This paper empirically evaluates the use of partial edges for a small-scaled Euler diagrams with graphs and tests whether Euler diagrams with partial edges are readable and interpretable. In this study, twenty participants were presented with eighteen manually drawn diagrams using a software which recorded the answers and the time taken to answer each question. The results indicate that there is no significant difference between diagrams having partial and non-partial edges in terms of accuracy and time (performance analysis) but users preferred partial edges to be aesthetically pleasing in terms of reading graphs in Euler diagrams and layout features (preference analysis), which means partial edges can be used as a strategy to avoid clutter. The results obtained from the task performance and preference will be useful in generating real small-world graphs in an optimal way. The paper concludes that partial edges in a graph does not significantly affect comprehension and as a further direction, our existing Euler diagrams with complete graphs (full edges) tool will be extended to partial edges and evaluated.

Understanding the structure of musical compositions: Is visualization an effective approach?:

Experienced musicians have the ability to understand the structural elements of music compositions. Such an ability is built over time through the study of music theory, the understanding of rules that guide the composition of music, and countless hours of practice. The learning process is hard, especially for classical music, where the rigidity of the music structures and styles requires great effort to understand, assimilate, and then master the learned notions. In particular, we focused our attention on a specific type of music compositions, namely, music in chorale style (four-voice music). Composing such type of music is often perceived as a difficult task because of the rules the composer has to adhere to. In this article, we propose a visualization technique that can help people lacking a strong knowledge of music theory. The technique exploits graphic elements to draw the attention on the possible errors in the composition. We then developed an interactive system, named VisualMelody, that employs the proposed visualization technique to facilitate the understanding of the structure of music compositions. The aim is to allow people to make four-voice music composition in a quick and effective way, that is, avoiding errors, as dictated by classical music theory rules. We have involved 40 people in testing VisualMelody in order to analyze its effectiveness, its usability, and the overall user satisfaction. We partitioned the people involved in the evaluation study into two groups evenly splitting the musical expertise. Then, we had one group use VisualMelody without the visualization facilities and the other using the tool enhanced with our visualization. On average, people in the group that used our visualization were 60% faster and produced music with less errors.

Immersivity and Playability Evaluation of a Game Experience in Cultural Heritage

The introduction in the market of head-mounted displays (HDMs), originally used for gaming, opens the door to a wide set of application fields that could benefit of characteristics, such as immersivity, presence as well as a high degree of realism. In the field of Cultural Heritage, an immersive virtual experience can enhance playfulness and involvement in the fruition of a cultural experience, by determining a more efficient knowledge absorption and retention of the learnt content.

Visualization of Music Plagiarism: Analysis and Evaluation

Nowadays plagiarism is an interesting and debated topic in different fields. In music, the plagiarism is a very common phenomenon which touch the vast amounts of money that music melodies are able to generate in todays pop music market. In a music composition, the melody is assumed to be the most significant factor in a courts decision about whether a new music composition is an illegitimate version of a pre-existing composition. Despite the wide-spread belief that there is a fixed and trivial number of corresponding notes between two melodies, the similarity analysis is a very complex process. In this paper we address the plagiarism in pop music, and specifically, we study whether visualization can facilitate the task of discovering melodic similarities among musical songs. To investigate this, we defined three representations to show the melodic relations among songs. We performed a user study in which subjects performed different tasks on a song collection using these representations to investigate which one is best in terms of intuitiveness and accuracy. Results of the study provided us with positive feedback as well as further directions to explore.

A Platform to Collaborate around CFD Simulations

This paper describes Floasys, a web-based platform to foster the collaboration among Computational Fluid Dynamics analysts and to promote model reuse by centrally managing simulation data and providing metadata annotations and search functionality over them. In this way, CFD analysts access to simulation data and results performed by different engineers and are able to leverage on them to make the right design decisions.

Engaging Citizens with a Social Platform for Open Data

Open Data are valuable initiatives in favour of transparency. Public administrations are increasing the availability of datasets for citizens, associations, innovators and other stakeholders, by releasing their data with open licenses. Open initiatives are achieving less success than expected, mainly due to the lack of engagement. There is a growing demand for approaches to actively engage citizens in exploiting Open Data. This paper introduces SPOD, a Social Platform for Open Data, which aims to engage citizens, local associations and organizations in forming communities of interests, stimulating the interpretation of Open Data and exploiting their use in Data-driven discussions, something not well-supported on traditional social networks. Social collaboration is the key aspect to increase the public value, where citizens participate in the discussions, co-create knowledge and data. The paper describes the engagement of four communities of citizens, which contributed to the public value by discussing topics in the context of Cultural Heritage, generating information from existing and co-created open datasets, by using SPOD.