Abstract

Abstract
Four research projects used Second Life", a 3D virtual-world platform, to investigate aspects of technology-enhanced STEM education. These European and USA studies, which differ in their pedagogical-philosophy commitments, theoretical frameworks, methodologies, and target content, critically examine a range of cognitive, affective, technical, and social factors pertaining to the prospects of students' and teachers' successful engagement with immersive microworlds. Specifically, each project describes students' successes and challenges in creating complex virtual artifacts and collaborating in real time with peers and the broader community. The design-based research studies of mathematical and computational literacy present sample student artifacts and discuss the learning they evidence. Collectively, we posit that overcoming the following obstacles could make virtual worlds both effective and exciting learning environments: professional development (technical skill, affective disposition), collaboration with school systems (logistics of access, allocation of resources), alignment with targeted content (harnessing students' creative divergence), and initial learning curves (issues of teacher-to-student ratio).

Abstract

Abstract
It is stated that a closer intervention of experts in knowledge discovery can complement and improve the effectiveness of results. Normally, in data mining, automated methods display final results through visualization methods. A more active intervention of experts on automated methods can bring enhancements to the analysis; No meanwhile that approach raises questions about what is a relevant stopping stage. In this work, efforts are made to couple automatic methods with visualization methods in the context of partitioning algorithms applied to spatial data. A data mining workflow is presented with the following concepts: data mining transaction, data mining save point and data mining snapshot. Moreover to display results, novel visual metaphors are changed allowing a better exploration of clustering. In knowledge discovery, experts validate final results; certainly it would be appropriate to them validate intermediate results, avoiding, for instance, losing time, when in disagreement, starting it with new hypnoses or allow data reduction by disable an intermediate cluster from the next stage.

Abstract
Radio Frequency Identification (RFID) is one of the automatic identification technologies more in vogue nowadays. There is a wide research and development in this area trying to take maximum advantage of this technology, and in coming years many new applications and research areas will continue to appear. This sudden interest in RFID also brings about some concerns, mainly the security and privacy of those who work with or use tags in their everyday life. RFID has, for some time, been used to access control in many different areas, from asset tracking to limiting access to restricted areas. In this paper we propose an architecture and a prototype of a system that uses distributed RFID over Ethernet and we demonstrate how to automate an entire students' attendance registration system by using RFID in an educational institution environment. Although the use of RFID systems in educational institutions is not new, it is intended to show how the use of it came to solve daily problems in our university. © 2008 IEEE.

Abstract
Currently, due to questions of financial order, the Internet Service Providers do not invest in rural areas, because the investment does not pay. This fact originates, more and more, the appearance of the so called WBN (Wireless Broadband Networks), that are going to supply Internet access to the populations, discriminated by this circumstance. The aspects related to the management of these networks are normally forgotten and today there is a lack of economically and technical viable solutions, that can efficiently help with this function, without use an enterprise solution. After an intensive research of commercial and opensource solutions of wireless networks management, it was checked an absence of an economically viable solution as well as an absence of a model of management for the WBN. This article contributes to the definition of a management model of these networks, using opensource tools. The proposal model is based on a centralized solution that congregates several modules of opensource tools, which can be able to respond to a wide range of features identified in the model. The simulation shows how the model presented, can be practicable and able to cover several functions in WBN management. © 2008 IEEE.