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In this paper we describe a new tool for interactive presentations: the speaker shows a common slideshow on the screen, and the users can see the same slide in their smartphone or tablet, independently from its model and brand. The system can be used for both on-line and on-site presentations and encourages the user to perform social activities, e. g., comment or like a slide. The author can also submit a questionnaire or a poll to the audience and see in real-time the answers. Our tool has been used during 37 different events, followed by 3753 users. We recorded the actions of the users and, depending on the different kind of events, the average of actions ranges from 1 to 8 per user per presentation. This data shows that our tool helps to increase users engagement and to maintain user attention.

In this paper we analyze frameworks for mobile cross-platform development according to their influence on energy consumed by the developed applications. We consider the use of different smartphones sensors, e.g., GPS, accelerometer, etc., and features, e.g., acquiring video or audio from the environment. In particular, we have studied how the amount of required energy for the same operation changes according to the used framework. We use an hardware and software tool to measure energy consumed by the applications developed natively, as a web application or using two frameworks, Titanium and PhoneGap. Our experiments have shown that frameworks have a significant impact on energy consumption which greatly increases compared to an equal native application. Moreover, the amount of consumed energy is not the same for all frameworks.

Stress condition, if experienced for an extended amount of time, can negatively affect individual's health. Several external sensors monitoring different physiological states correlated with stress, or smartphone apps that monitor individuals context, have been leveraged to assess stress state in everyday life. The less intrusive ''human-smartphone interaction'' have been under-investigated so far. In our research we leverage 'swipe', 'scroll' and 'text input' interactions to assess the stress state of smartphone users. Based on data collected from 13 participants, we leverage 'swipe' and 'scroll' data to assess stress with an average F-measure of 79-85% for a within-subject model, and of 70-80% when building a global model. Moreover, 'text input' via a virtual keyboard has been analyzed, showing how several easy to calculate features enable to differentiate between stress and no-stress state. To the best of our knowledge, this is the first attempt to leverage human-smartphone interaction, and in particular 'swipe', 'scroll' and 'text input' interactions, to accurately assess stress state in individuals without using any external sensor or leveraging privacy-sensitive context information.

In this paper we present a model and an adaptation architecture for context-aware multimodal documents. A compound virtual document describes the different ways in which multimodal information can be structured and presented. Physical features are associated to media instances, while properties describe the context. Concrete documents are instantiated from virtual documents by selecting and synchronizing proper media instances based on the user context: the situation, the environment, the device and the available communication resources. The relations between the context features and the media properties are described by a rule based system.

The paper presents a comparison between different frameworks for cross-platform mobile development, MoSync, Titanium, jQuery Mobile and Phonegap, with particular attention to development of applications with animations. We define a set of criteria for the evaluation and we develop the same game as case study app, with the aim to provide an unbias judgement. Our analysis recommends Titanium as the best framework to develop mobile applications with animations.

The increasing number of people that are overweight due to a sedentary life requires persuasive strategies to convince people to change their behaviors. In this paper, we present a machine learning based technique to recognize and count stairsteps when a person climbs or descends stairs. This technique has been used as part of ClimbTheWorld, a real-time smartphone application that aims at persuading people to use stairs instead of elevators or escalators, since an engaging activity has more chance to change people's life habits. We perform a fine-grained analysis by exploiting smartphone sensors to recognize single stairsteps. Data-dependent sliding windows are used facilitating the learning process and reducing the computational cost. Finally, energy consumption is widely investigated to optimize the trade-off between classification precision and battery usage, to avoid exhausting smartphone battery.

Dyslexia is a learning disability affecting the ability to process written and sometimes even spoken language. It affects educational opportunities of about 10% of children, regardless of their intelligence. One of the main challenges is to be able to identify Dyslexia in preschoolers. To this aim we have developed a set of serious games that are the core of this demo. Our games have been created with a multiplatform approach so as to generate, in a single effort, game versions for mobile platforms and the Web. They have also been designed to be adequately challenging and fun for their target users, as well as effective.

Web 2.0 is evolving and offering services based on the wide popularity of smartphones and the possibility of gathering data ubiquitously from these mobile devices; this new paradigm is often referred to as Web2. In this paper, we hence present and discuss a Web2 application designed to enable users to interact with remote smartphones' cameras to receive a video generated in real time. In essence, users can individuate on a map which mobile cameras are available in a location of interest and request the remote user to generate and send back a short video of the surrounding environment or event. We discuss technical issues related to implementing such a service and the solutions we devised to address them. Finally, we also present experimental results we obtained from a preliminary testbed evaluation that encourages the prosecution of this work.

In this paper, we consider the problem of automatic verification of SMIL documents and present a tool which can assist the user in the complex task of authoring a multimedia presentation. The tool is based on a formal semantics defining the temporal aspects of SMIL elements by means of a set of inference rules. The rules, in the spirit of Hoare's semantics, describe how the execution of a piece of code changes the state of the computation of a player. If any temporal conflict is found, the system returns a message to the user pointing out the element which contains the conflict and its motivation. This helps the user to develop robust and clear code.

One of the major problems of doctors when dealing with children is to capture and maintain their attention. This is particularly true for oculists that must test children eyes, especially if they are very young. In this paper we present PlayWithEyes, a serious game that aims at testing the children eyes while they are having fun playing with Lea symbols and images taken from popular cartoons, using a touch interface. PlayWithEyes was created to perform screening of visual acuity of very young children, since early diagnosis is very important for some sight defects like amblyopia (lazy eye).

In this paper we define a formal semantics for the language SMIL which can be used in a number of applications. First of all, we propose a computer aided authoring system which include a Semantic Validator Module for the evaluation of the temporal consistency of the resulting multimedia presentation. If any temporal conflict is found, the system returns to the user a message pointing out the tag which contains the error and its motivation. This helps the user to correct the error. We also introduce a notion of equivalence for SMIL tags which is useful to find a candidate for substitution in the development of complex multimedia structure, for example in the context adaptation process.

Multimedia documents are collections of media objects, synchronized by means of sets of temporal and spatial constraints. Any multimedia document definition is valid as long as the referred media objects are available and the constraints are satisfiable. Document validity depends on the context in which the document has to be presented. In this paper, we introduce a framework to characterize context adaptation, in the presence of both physical and user oriented context requirements. We define semantically equivalent presentation fragments as alternative to undeliverable ones. In the absence of equivalence, undeliverable media are replaced with candidates that minimize the loss of information/quality in the presentation.

In this article we describe a prototyping environment, which allows an author to set up and test a complex hypermedia presentation. It contains a visual editor, based on a graph notation, in which the nodes are media objects and the edges are the synchronization relations between them; an execution simulator, which helps the author to test the presentation dynamics by manually triggering media related events; and a player, which allows the author to preview the presentation and to visually relate the execution evolution with the interpretation of the synchronization schema.

We present a framework for the design and management of multimodal document databases: virtual documents describe the dieren t facets under which information can be delivered and presented, in terms of media, content, and presentation format. Concrete documents are composed and instantiated from virtual ones by aggregating and synchronizing media instances based on the user context, i.e., the situation, the environment, the devices and communication resources available.

This paper presents a synchronization model for hypermedia presentations. Several media, continuous, like video and audio files, and non-continuous, like text pages and images, are delivered separately in a distributed environment like the World Wide Web, and presented to the user in a coordinated way. The model is based on a set of synchronization relationships which define media behavior during presentation playback, channels in which to play them, and the effects of user interaction. The model is suited for a wide range of applications, among which self and distance education, professional training, Web advertising, cultural heritage promotion and news-on-demand are good representatives. The model is formally described in terms of changes in the presentation state due to media-related events. A virtual exhibition is analyzed as a test bed to validate the model.

In this paper we discuss issues concerning the consistent retrieval of parts of multimedia presentations from multimedia repositories. We introduce a class of multimedia presentations made of independent and synchronized media and discuss retrieval requirements of presentation fragments. Then we discuss a retrieval model capable of reconstructing the fragments of a presentation from the atomic components returned by the execution of queries to multimedia presentation repositories. The retrieval model is based on an automaton that formally describes the presentation states entered by the events that trigger media playback. Retrieving a consistent fragment corresponds to building a new presentation with all the media related to the retrieved ones, with their original structural and synchronization relationships.

Data-centered approaches to multimedia presentation design and implementation can be developed by extending methodologies and technologies common in text-based applications. A multimedia report is a multimedia presentation built on a set of data returned by one or more queries to multimedia repositories, integrated according to a template with appropriate spatial layout and temporal synchronization, and coherently delivered to a user for browsing. We discuss the problem of defining templates for such multimedia reports with a focus on media coordination and synchronization. Multimedia presentations can be automatically generated according to the template by instantiating it on actual data instances. An XML language describes the spatial layout and the temporal constraints of the media objects. An authoring system and a player have been implemented.

Multimedia documents are an effective way to present different kinds of information, since the integration of different media types gives more expressive power and opportunities to catch the user attention. A multimedia report is a multimedia presentation built on a set of data returned by one or more queries to multimedia repositories, integrated according to a schema with appropriate spatial layout and temporal synchronization, and coherently delivered to a user for browsing. We discuss the problem of defining schemas for such multimedia reports with a focus on the media coordination and synchronization constraints. Multimedia presentations can then be automatically generated according to the schema. We have defined an XML language to describe the spatial layout and the temporal constraints of the media objects, together with a visual authoring system helping the user to design the presentation template.