Abstract
This paper presents a comparative analysis between a set of virtual worlds in order to facilitate the process of selecting a virtual world to serve as a platform for application development. Based on exhaustive research in the area, we selected a set of criteria, based on the work of Mannien in 2004 and Robbins in 2009. After this identification we applied the Quantitative Evaluation Framework (QEF) developed by Squire in 2007 with the aim of assessing quantitatively the platforms under consideration. The results showed that Second Life, OpenSim and Active Worlds are platforms that offer more services and tools for developing applications with quality. © 2011 AISTI.

Abstract
Advertisers struggle to reach effectively and efficiently to their customers, continuously seeking to influence them and simultaneously reduce the overall publicity costs. Business areas like the mobile devices industry, together with wireless technologies and interactive environments, bring an huge opportunity for marketing purposes. supporting the chance to turn advertising into a convenient and easily accessible source of information by letting marketers communicate with costumers in a more direct, personal and contextualized way. This paper presents some foundations for the development of a system that will allow context-aware personalized profile-based advertising delivery, by using Bluetooth technology to identify and communicate with customers in a given geographic area, through their mobile devices.

Abstract
With Virtual Reality (VR) systems it is possible to visualize three-dimensional environments with a high level of detail and visual fidelity. The users can manipulate and interact with those virtual environments in an intuitive way, close to reality. The VR systems enable the access to digital services that can promote, amongst others, collaborative work, data sharing or e-commerce. In this paper, we present a multidisciplinary solution that can offer added value to users through a collaborative environment with an intuitive interface. This environment will use geo-referenced databases to replicate urban environments and represent real world problems in a virtual way, making possible a better and more flexible approach in order to solve them. It is also proposed an architecture and some digital services are illustrated to show its potential.

Abstract
Location-based mobile services (LBMS) are at present an ever growing trend, as found in the latest and most popular mobile applications launched. They are, indeed, supported by the hasty evolution of mobile devices capabilities, namely smart phones, which are becoming truer mobile pocket-computers; by users demand, always searching for new ways to benefit from technology, besides getting more contextualized and user-centred services; and, lastly, by market drive, which sees mobile devices as a dedicated way to reach customers, providing profile-based publicity, products, discounts and events. With e-commerce, products and services started arriving to potential customers through desktop computers, where they can be bought and fast delivered to a given address. However, expressions such as "being mobile", "always connected", "anytime anywhere" that already characterize life in the present will certainly continue to do so in the near future. Meanwhile, mobile devices centred commerce services seem to be the next step. Therefore, this paper presents a system architecture designed for location-based e-commerce systems. These systems, where location plays the most important role, enable a remote products/services search, based in user parameters: after a product search, shops with that products are returned in the search results and are displayed in a map, around the user present location; and services like obtaining more information, reserving and purchasing are made available as well. This concept represents a mix between traditional client-oriented commerce and faceless mass-oriented e-commerce, enabling a proximity-based user-contextualized system, being well capable of conveying significant advantages and facilities to both service-providers/retailers and users. © 2011, IGI Global.

Abstract
On the internet one can find all kinds of information and perform a multitude of tasks such as searching for information about any subject, purchase goods and services, or enquiring about a particular company. When navigating the web, our focus (where we look) can be captured involuntary through a visual stimulus, or may be directed in a controlled manner depending on the task that we are performing. The layouts of web sites range from simple to highly complex. When creating new layouts, knowing what information is most important when a user is performing a task and which areas are supposed to attract his/her attention are important issues in order to make a web site easier to interpret and consequently their usability. In this paper we present an eye tracking study of users' visual behaviour when surfing on websites and investigate if it is possible to determine likely visual patterns. We show that the visual patterns are different depending on the task that is being performed and not on the web site where it is being carried out. © 2011 ACM.

Abstract
The academic performance and social competence of a child in school is positively associated with the involvement of their parents. However, the researches about educational learning models often ignore the parents' part. Internet opens a new paradigm: education and communication approach is more complex than ever. Here, we would like to present an Internet based system to support students' homework. We believe that one of the major advantages of our system is time saving, particularly from the teacher's point of view. Also, this system gathers statistical data concerning different groups of students selected by the teacher. From these data on, the teacher can easily see where the students are having problems and decide what to do next. From the student (or parent) point of view, the prompt feedback about the exercises correctness, added to the training with different exercises sets about the same subject, besides the utilization of video, color, sound, etc., that positively reinforce child's senses, are elected as the main advantages. © 2011 IEEE.