Abstract
Mayer's energy decomposition method was applied inthe study of the relative stability of cis and trans isomers of 1,2-disubstituted ethylenes, XHC=CHX (X = F, Cl, Br) and 2-butene. The trans to cis isomerization energy for each system was determined at the Hartree-Fock level, with several basis sets, and then divided into monoatomic and diatomic energy contributions. The results point to a different energy distribution for the dihaloethylenes, known for exhibiting a cis isomer that is more stable than the trans one, a behavior that is known as the cis effect, when compared to 2-butene. The main stabilizing effects of the cis isomer in the dihaloethylenes, at this level of theory, are energy terms associated with the interaction of the X substituents with the C atoms.

Abstract
Nowadays, tourists are increasingly thirsty for information on anything that surrounds him. With the Information Communication Technologies (ICT) evolution that supports the ubiquity, it is necessary to rethink the available models of information and services to tourists. With the evolution of mobile devices, with wireless access, together with the decreasing of the network traffic costs and with the increasing number of access points of wireless access, becomes more common and attractive. Therefore, in this paper we present an analysis of the state of the art of the support applications for tourists for mobile environments, setting them according to the development technologies. In addition, it is also presented a suitable framework to support the tourist's needs based on a ubiquitous approach.

Abstract
This study illustrates and discusses an original approach to classify the electricity consumers according to their daily load patterns. This approach exploits the notion of entropy introduced by Renyi for setting up specific clustering procedures. The proposed procedures differ with respect to typical methods adopted for electricity consumer classification, based on the Euclidean distance notion. The algorithms tested include firstly a classical method based on the between-cluster entropy and its slight variation. Then, a novel procedure is presented, based on the calculation of the similarity between centroids, with successive refinement to allow effective identification of the outliers. The outcomes of the classification carried out by using the proposed procedure are compared to the results of other available techniques, using a set of clustering validity indicators for ranking the clustering methods. On the basis of these results, it emerges that the novel procedure exhibits better clustering performance with respect to both the literature approaches and the classical entropy-based method, for different numbers of clusters. The results obtained are of key relevance for assisting the electricity suppliers in identifying a reduced number of load pattern-dependent classes, to be associated with distinct consumer groups for load aggregation or tariff purposes. © 2010 © The Institution of Engineering and Technology.

Abstract
The estimation of 1 dB compression and third-order intercept points can be obtained after the cross-correlation between dynamic current and output voltage of radio frequency power amplifiers. This estimation is performed using actual power measurements and not power inferred from voltage values. The underlining theory and a correlator that allows implementing this measurement on-chip are presented. The trade-off between measuring voltage and the actual power is also discussed and it is shown that different information concerning the output load is obtained when observing the PA's output voltage and power. Simulation results, obtained with the model of a prototype demonstration chip, show that good accuracy can be obtained with relatively simple measurement conditions. These results include the analysis of optimum stimuli amplitudes and the effect of noise in estimation accuracy.

Abstract
This paper analyses the value added (VA) of a sample of Portuguese schools using two methodologies: data envelopment analysis (DEA) and the methodology used presently by the UK Department for Children, Schools and Families (DCSF). The VA estimates obtained by the two methods are substantially different. This reflects their different focus: DEA emphasizes on best-observed performance, whereas the DCSF method reveals average performance. The main advantage of the methodology used by the DCSF is its simplicity, although it confounds pupil effects with school effects in the estimation of school VA. In contrast, the DEA methodology can differentiate these effects, but the complexity may prevent its use in a systematic way. This paper shows that the two methods provide complementary information regarding the VA of schools, and their joint use can improve the understanding of the relative effectiveness of schools regarding the progress that pupils make between educational stages.

Abstract
As the number of handicapped people increases worldwide, Intelligent Wheelchairs (IW) are becoming the solution to enable a higher degree of independence for wheelchair users. In addition, IW Projects relevance is increasing, mainly in the fields of robotics and safety-related systems due to their inherent and still unresolved problems related with environment uncertainty, sale communications and collaboration methodologies. This paper describes the development of new communication system, based on multi-agent systems (MAS) methodologies and motivated by Intelligent Wheelchair systems, as a mean to enable fault-tolerant communications in open transmission systems and as an agent collaboration enabler. It provides an overview of the related work, the background and the main constraints to system development. It; proposes and discusses a new communication model, based on messages, for multi-agent; systems, that tackles the problems that exist in a dynamic and uncertain environment in the field of mobile robotics. The achieved results enable us to conclude on time effectiveness of the proposed communication model and its adequacy to the field of mobile robots in dynamic environments while establishing a comparison with a commonly used Multi-Agent Platform, JADE.