Abstract
Interactive visualization of virtual environments is an active research topic. There is a multiplicity of applications such as simulation systems, augmented and mixed reality environments, computer games, amongst others, which endlessly demand for greater levels of realism and interaction. At every stage of the process, including modeling, image synthesis, transmission and navigation, there are identifiable circumstances which may compromise the achievement of high quality solutions for the posed problems. For many of these problems, an effective use of optimization tools can play a major role in order to achieve solutions with better quality. Within this context, an innovative optimization architecture is presented regarding to two major principles. The first principle comprises the possibility to integrate, with reduced effort, the optimization tools with existent applications and systems. Thus, we propose an agent-based framework where the optimization application may operate as an independent process in respect to the visualization application where communication is achieved by means of a specifically developed high-level message based protocol. The second principle establishes on the utilization of a class of intelligent optimization methods, known as metaheuristics, which major distinguishing quality is their great level of problem-independence, thus, enabling a wider application. The paper describes conducted experiments and presents results that demonstrate the utility and efficacy of the proposed framework.

Abstract
The growing demand for virtual urban models in emerging areas of interest has promoted a variety of techniques for automating the creation of virtual scenes with a high level of realism. However, visualization is not always the only aim in many applications. Increasingly, urban systems are also required for management, analysis, or interaction with very different types of information. Three-dimensional (3D) urban entities should maintain neighbor relations, and being inserted in a geospatial database in order to enable associative queries, one of the most important features associated with 3D urban geographic information system (GIS). Additional challenges are found when these three-dimensional models are implemented in web-based systems. This paper proposes a method for automatic modeling of buildings and street surfaces of entire real cities by combining computer graphics, computational geometry, and GIS techniques. The sources of information employed are two-dimensional (2D) GIS and its associated digital elevation models (DEMs) in order to provide real terrain features. The virtual environment supports web-based navigation and data interaction. The case study was performed in Jaen, Spain, a hilly city with more than 1,000 blocks of buildings. The 3D city model was generated using the public data provided by the general cadastral office of Jaen and the DEM information of this area. The topological relations between the geometric urban entities were inserted in the spatial database and the graphics and thematic information could be accessed through the Internet. All these features are highly desirable for decision making in urban planning. DOI: 10.1061/(ASCE)UP.1943-5444.0000131. (C) 2013 American Society of Civil Engineers.

Abstract

Abstract
Introduction. The strong dynamic nature of the Web is a well-known reality. Nonetheless, research on Web dynamics is still a minor part of mainstream Web research. This is largely the case in Web link analysis. In this paper we investigate and measure the impact of time in link-based ranking algorithms on a particular subset of the Web, specifically blogs. Method. Using a large collection of blog posts that span more than three years, we compare a traditional link-based ranking algorithm with a time-biased alternative, providing some insights into the evolution of link data over time. We designed two experiments to evaluate the use of temporal features in authority estimation algorithms. In the first experiment we compare time-independent and time-sensitive ranking algorithms with a reference rank based on the total number of visits to each blog. In the second, we use feedback from communication media domain experts to contrast different rankings of Portuguese news Websites. Results. The distribution of citations to a Web document over time contains valuable information. Based on several examples we show that time-independent algorithms are unable to capture the correct popularity of sites with high citation activity. Using a reference rank based on the number of visits to a site, we show that a time-biased approach has a better performance. Conclusions. Although both time-independent and time-aware approaches are based on the same raw data, the experiments indicate that they can be treated as complementary signals for relevance assessment by information retrieval systems. We show that temporal information present in blogs can be used to derive stable time-dependent features, which can be successfully used in the context of Web document ranking.

Abstract
Data warehouses are used in many application domains, and there is no established method for their preservation. A data warehouse can be implemented in multidimensional structures or in relational databases that represent the dimensional model concepts in the relational model. The focus of this work is on describing the dimensional model of a data warehouse and migrating it to an XML model, in order to achieve a long-term preservation format. This chapter presents the definition of the XML structure that extends the SIARD format used for the description and archive of relational databases, enriching it with a layer of metadata for the data warehouse components. Data Warehouse Extensible Markup Language (DWXML) is the XML language proposed to describe the data warehouse. An application that combines the SIARD format and the DWXML metadata layer supports the XML language and helps to acquire the relevant metadata for the warehouse and to build the archival format. Copyright (C) 2013, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited.

Abstract
The Software-Independent Archival of Relational Databases (SIARD) project developed a tool known as the "SIARD Suite" for preserving relational databases. The tool converts a relational database to a XML format. This paper presents the components of the SIARD Archive Browser which is a simple to use and platform-independent tool for browsing a SIARD Archive. This may be helpful for users interested in using the software. Moreover, it may be useful for people who want to re-use the code and develop software for browsing a SIARD archive with more functionality. © Springer International Publishing 2013.