A method to assess pervasive qualities in mobile games

Software designers are facing huge challenges imposed by a new generation of applications that mix real and digital worlds, such as pervasive games. This type of game has recently become a worldwide phenomenon, with thousands of people walking in the streets with smartphones to interact with the physical environment. In this paper, we propose a new method to assess pervasive qualities in pervasive mobile games, which can be customized and extended to other ubiquitous applications. This method generates a quality report, which consists of a quality spreadsheet (containing metric values and comments) and a quality vector (representing the game quality profile in the form of a bar chart). In addition, we can compare quality vectors using similarity criteria. In this paper, we apply the proposed method to commercial and academic prototype games to shed more light on their pervasive characteristics and identify ways to improve the overall quality that sets these games apart from traditional digital games—that is, pervasiveness.     

Investigating an advective approach to subgrid modeling in large-eddy simulations

The purpose of this paper is to investigate and validate an alternative subgrid model to be used in large-eddy simulations, based on an advective formulation. Rather than modeling the subgrid tensor that appears in the LES formulation as is commonly done, the subgrid force vector, which is the divergence of the subgrid tensor, is modeled directly. It is designed to comply with two basic principles. First, it is required to act only on the smallest scales that the mesh can represent. Second, it must be of an advective nature, which means it must have a preferred direction aligned with the fluid velocity. The results for two benchmark test cases, including Homogeneous Isotropic Turbulence and Turbulent Channel Flow, show that this approach can successfully represent the effect of the small scales on the resolved ones, while guaranteeing numerical stability and greater robustness in adverse mesh environments, when compared to some traditional eddy-viscosity based models, such as the Smagorinsky and the dynamic model from Germano.     

Learning chemistry with VirtualLabs@Uma: a customizable 3D platform for new experimental protocols

In general, students of laboratory courses such as chemistry or biology are not able to replicate at home an experiment of a previously studied class since they lack infrastructure and material. With the possibility of providing multimedia and virtual reality environments on the Web, different applications and virtual laboratories have been proposed. However, most of the existing tools are not flexible enough or are domain-oriented, not supporting the addition of new tailor-made experiments when needed. This paper introduces a new platform for providing a customizable Virtual Laboratory, VirtualLabs@UMa. This application was proposed at University of Madeira in order to provide students with a flexible 3D virtual laboratory and teachers with a platform that can be customized to new experimental protocols. Therefore, chemistry teachers are able to create their own experimental protocols and propose them to their students. Moreover, students can be followed accordingly having their learning needs and difficulties fulfilled. VirtualLabs@UMa is a solution for motivating students and proposing an added value for complementing laboratory courses.     

The Design, Implementation and Evaluation of an ODMG Compliant, Parallel Object Database Server

This paper describes the design, implementation and evaluation of a parallel object database server. While a number of research groups and companies now provide object database servers designed to run on uniprocessors, there has been surprisingly little work on the exploitation of parallelism to provide scalable performance in Object Database Management Systems (ODBMS). The work described in this paper takes as its starting-point the Object Database Management Group (ODMG) standard for object databases, thereby allowing the project to focus on research into parallelism, rather than on the ODBMS interfaces. The system is designed to run on a distributed memory parallel machine, and the paper describes the key issues and design decisions including: parallel query optimisation and execution, flow control, support for user-defined operations in queries, object distribution, cache management and navigational client access. The work shows that the significant differences between the object and relational database paradigms lead to significant differences in the designs of parallel servers to support these two paradigms. The paper presents an extensive performance analysis of the prototype systems which shows that good performance can be achieved on a cluster of linux PCs.     

Hybrid heuristic-waterfilling game theory approach in MC-CDMA resource allocation

This paper discusses the power allocation with fixed rate constraint problem in multi-carrier code division multiple access (MC-CDMA) networks, that has been solved through game theoretic perspective by the use of an iterative water-filling algorithm (IWFA). The problem is analyzed under various interference density configurations, and its reliability is studied in terms of solution existence and uniqueness. Moreover, numerical results reveal the approach shortcoming, thus a new method combining swarm intelligence and IWFA is proposed to make practicable the use of game theoretic approaches in realistic MC-CDMA systems scenarios. The contribution of this paper is twofold: (i) provide a complete analysis for the existence and uniqueness of the game solution, from simple to more realist and complex interference scenarios; (ii) propose a hybrid power allocation optimization method combining swarm intelligence, game theory and IWFA. To corroborate the effectiveness of the proposed method, an outage probability analysis in realistic interference scenarios, and a complexity comparison with the classical IWFA are presented.     

A review on polyphenols: Classification,beneficial effects and their application in dairy products

Recently, the number of studies regarding the physiological activities of food‐derived bioactives and food components with functional properties has greatly increased. Many studies have emphasised the beneficial effects of polyphenols regarding their antioxidant, antiproliferative and anti‐inflammatory properties. This study highlights their application in dairy products, notes in which form they are applied and discusses the effects on the physicochemical and sensory characteristics of products, although some dairy matrices remain unexploited. It was noted that the inclusion of polyphenols improves not only the antioxidant properties but also, in some cases, the sensory attributes. This review also includes the synthesis, classification and beneficial effects of polyphenols.     

Measuring and modelling the performance of a parallel ODMG compliant object database server

Object database management systems (ODBMSs) are now established as the database management technology of choice for a range of challenging data intensive applications. Furthermore, the applications associated with object databases typically have stringent performance requirements, and some are associated with very large data sets. An important feature for the performance of object databases is the speed at which relationships can be explored. In queries, this depends on the effectiveness of different join algorithms into which queries that follow relationships can be compiled. This paper presents a performance evaluation of the Polar parallel object database system, focusing in particular on the performance of parallel join algorithms. Polar is a parallel, shared‐nothing implementation of the Object Database Management Group (ODMG) standard for object databases. The paper presents an empirical evaluation of queries expressed in the ODMG Query Language (OQL), as well as a cost model for the parallel algebra that is used to evaluate OQL queries. The cost model is validated against the empirical results for a collection of queries using four different join algorithms, one that is value based and three that are pointer based. Copyright © 2005 John Wiley & Sons, Ltd.     

Extraction of Coriander Oil Using Twin‐Screw Extrusion: Feasibility Study and Potential Press Cake Applications

This study presents an assessment of the vegetable oil extraction from coriander fruits through mechanical pressing, more specifically twin‐screw extrusion. This comprises an evaluation of the oil recovery obtained and its respective quality, as well as the specific mechanical energy, representing an economical point of view. With regard to the extrusion optimization, the screw configuration, the device's filling coefficient and the pressing temperature were varied. The screw configuration was shown to exhibit a key influence on the extraction efficiency and oil recoveries of at least 40 % were reached when the pressing zone was positioned immediately after the filter and consisted of 50 mm long, reverse screws with a ‐33 mm pitch. Furthermore, with a device's filling coefficient of 39.4 g/h rpm and a pressing temperature of 120 °C, an oil recovery of 47 %, the highest of this study, was reached with concurrent low energy consumption. Next to this, operating parameters of 47.1 g/h rpm and 80 °C resulted in the production of a press cake with the lowest residual oil content (15 %) in this study, although this also involved a significant increase in the filtrate's foot content. All the produced oils were of acceptable quality (<1.5 % acidity), showed high petroselinic acid content (73 %), and were pleasantly scented.