Abstract
This work explores an application of the spatial prisoner's dilemma in two situations: when all agents use the same type of behavior and when they use a mix of behaviors. Our aim is to explore the evolutionary dynamics of this game to analyze the dominance of one strategy over the other. We also investigate, in some possible scenarios, which behavior has better performance when they all coexist in the same environment.

Abstract
State estimator is vital for on-line power system monitoring, analysis and control. With the increasing use of synchronized phasor measurement units (PMU) in power grids, how to utilize phasor measurements to improve the precision of state estimator becomes imperative. In this paper, a state estimator including voltage phasors, injected current phasors and traditional measurements is proposed. 14 IEEE bus system and 30 IEEE bus system are used as test systems and the simulation results demonstrate that the presented state estimation algorithm combining traditional SCADA measurements with PMU (Phasor Measurement Unit) measurements for power system state estimation improves the precision greatly. © 2011 INESC Coimbra.

Abstract
This paper presents a printed two C-shaped monopoles antennas array for dual-band WLAN application. The two antenna elements are closely spaced at a distance of only 0.09 2.4GHz. High isolation between these two radiation elements is achieved by using the neutralization technique, which has been demonstrated as an effective way to increase the isolation for single band PIFA antennas [1, 2]. In this work, the neutralization technique has been implemented to the printed monopole antenna design. We demonstrate that by introducing two RF switches, we can not only design a compact monopole antenna array with high isolation for single band operation but also can extend this method to design a compact dual band antenna array. The proposed antenna array contains two C-shaped monopoles with a shorting line, on which two RF switches were integrated, connecting two arms of the antenna elements. Experiment results indicate that the proposed antenna array has a 10dB bandwidth that covers the required frequencies for dual-band WLAN applications (2.4/5.2GHz) with isolation higher than 15dB over both operation bands. The proposed antenna has been designed and optimized using Ansoft HFSS. © 2011 IEEE.

Abstract
Various programming languages allow the construction of structure-shy programs. Such programs are defined generically for many different datatypes and only specify specific behavior for a few relevant subtypes. Typical examples are XML query languages that allow selection of subdocuments without exhaustively specifying intermediate element tags. Other examples are languages and libraries for polytypic or strategic functional programming and for adaptive object-oriented programming. In this paper, we present an algebraic approach to transformation of declarative structure-shy programs, in particular for strategic functions and XML queries. We formulate a rich set of algebraic laws, not just for transformation of structure-shy programs, but also for their conversion into structure-sensitive programs and vice versa. We show how subsets of these laws can be used to construct effective rewrite systems for specialization, generalization, and optimization of structure-shy programs. We present a type-safe encoding of these rewrite systems in Haskell which itself uses strategic functional programming techniques. We discuss the application of these rewrite systems for XPath query optimization and for query migration in the context of schema evolution.

Abstract
In this study, we analyze firms' membership in R&D (Research and Development) cooperation networks trough simulation methods. Our main research hypothesis is that the membership in cooperation networks is related to the degree of the knowledge spillover. The approach has two scenarios: cost symmetry and cost asymmetry. We first develop an analytical model with three stages: firstly, firms decide whether to participate in a cooperative research network; secondly they simultaneously choose the level of R&D output, and finally they choose the level of output. Then we proceed with computational simulations to verify our hypothesis. From our results, we were able to conclude that cooperation leads to an improvement on RJV firms' position in the market as they produce more than others with the same production conditions. Additionally, cooperating firms have to spend fewer resources on research, which turns the network a tremendous success on the productive efficiency level.

Abstract
Real-time email classification is a challenging task because of its online nature, subject to concept-drift. Identifying spam, where only two labels exist, has received great attention in the literature. We are nevertheless interested in classification involving multiple folders, which is an additional source of complexity. Moreover, neither cross-validation nor other sampling procedures are suitable for data streams evaluation. Therefore, other metrics, like the prequential error, have been proposed. However, the prequential error poses some problems, which can be alleviated by using mechanisms such as fading factors. In this paper we present GNUsmail, an open-source extensible framework for email classification, and focus on its ability to perform online evaluation. GNUsmail's architecture supports incremental and online learning, and it can be used to compare different online mining methods, using state-of-art evaluation metrics. We show how GNUsmail can be used to compare different algorithms, including a tool for launching replicable experiments.