Abstract

Abstract
Crowdsourcing has become an essential source of information for tourists and tourism industry. Every day, large volumes of data are exchanged among stakeholders in the form of searches, posts, shares, reviews or ratings. Specifically, this paper explores inter-guest trust and similarity post-filtering, using crowdsourced ratings collected from the Expedia and TripAdvisor platforms, to improve hotel recommendations generated by incremental collaborative filtering. First, the profiles of hotels and guests are created using multi-criteria ratings and inter-guest trust and similarity. Next, incremental model-based collaborative filtering is adopted to predict unknown hotel ratings based on the multi-criteria ratings and, finally, post-recommendation filtering sorts the generated predictions based on the inter-guest trust and similarity. The proposed method was tested both off-line (post-processing) and on-line (real time processing) for performance comparison. The results highlight: (i) the increase of the quality of recommendations with the inter-guest trust and similarity; and (ii) the decrease of the predictive errors with the on-line incremental collaborative filtering. Thus, this work contributes with a novel method, integrating incremental collaborative filtering and inter-guest trust and similarity post-filtering, for on-line hotel recommendation based on multi-criteria crowdsourced rating streams.

Abstract
Optical waveguides were fabricated in alkaline earth boro-aluminosilicate glass, by femtosecond laser direct writing, with varying pulse energy and scan velocity. A spectral characterization, from 500 nm to 1700 nm, was made in order to determine their losses and understand its dependence on the processing parameters. Three major loss mechanisms were identified. At longer wavelengths, loss is mainly due to weak coupling. On the other hand, the behavior at shorter wavelengths is governed by propagation loss due to Rayleigh scattering, which was shown to be practically eliminated (& x003C; 0.05 dB $\cdot$ cm $<^>{-1} {\cdot }\,\,\mu \text{m}<^>{4}$ ) at higher scan velocities. Bulk absorption was also found to have an influence in the propagation losses at higher wavelengths. The combination of intermediate pulse energies (between 125-250 nJ) and high scan velocities (above 6 cm/s) allowed the fabrication of optical waveguides offering low losses across the entire range of wavelengths tested, facilitating applications that require larger wavelength working bands. Furthermore, since optimal fabrication conditions are achieved at higher scanning velocities, mass production with reduced fabrication times can be achieved.

Abstract
Nowadays statistics plays a major role either in society or in the research fields, with a particular emphasis in decision-making, therefore the importance of statistical inference. Statistical inference teaching is a new chapter, so this is an innovative study in Angola, since the scientific council of Polytechnic School of Malanje (PSM, Angola) had to agree to change the course syllabus in order to include the topics of statistical inference, in which confidence intervals (CI) and hypothesis testing were proposed by the first time in Angolan higher education. This work is part of a broader research that has adopted the theoretical framework of the Ontosemiotic Approach (OSA) since we are trying to overcome the error and difficulties of the students, using the semiotic conflict concept. Those conflicts are of two kinds: conflicts in using the new concepts of CI and conflicts that arise by the use of the spreadsheet. In this smaller work, we focus on the teaching of confidence intervals using the spreadsheet, in the course of Probabilities and Statistics in the PSM (Angola) during the academic year 2017/2018. The statistical inference through teaching confidence intervals in the course of Probability and Statistics of PSM was taught for the first time, as well as the a technologic tool, the spreadsheet. In this paper, our main goal is to present the classes planning of this module and it is qualitative and descriptive work. After the planning stage, we describe what the students were asked to do with the spreadsheet after completing the suggested problems using paper and pencil. The spreadsheet was selected since all students have it in their laptop and they may easily use it. During this first implementation of the CI classes, students did find the difficulties and made some of the errors described in the literature. Nevertheless, we noticed a great satisfaction from the students and they were motivated with this theme, and were very enthusiastic by the use of the spreadsheet and hopefully other topics in this Probabilities and Statistics course will also use it.

Abstract
This project aimed to analyze the practical difficulties in storing and moving a high range of products making the process easier and more efficient. The objectives were to improve the use of available space in the raw materials warehouse and ensure the effectiveness, efficiency and reduction of the periods between the transportation from raw materials to production lines. The work developed focused on improving internal processes, storage practices and internal transportation. In fact, for the production flow to be continuous, the supply must be aligned with the production to ensure that there is no failure of materials.

Abstract
We introduce a framework for the reconstruction of the amplitude, phase, and polarization of an optical vector-field using measurements acquired by an imaging device characterized by an integral transform with an unknown spatially variant kernel. By incorporating effective regularization terms, this new approach is able to recover an optical vector-field with respect to an arbitrary representation system, which may be different from the one used for device calibration. In particular, it enables the recovery of an optical vector-field with respect to a Fourier basis, which is shown to yield indicative features of increased scattering associated with tissue abnormalities. We demonstrate the effectiveness of our approach using synthetic holographic images and biological tissue samples in an experimental setting, where the measurements of an optical vector-field are acquired by a multicore fiber endoscope, and observe that indeed the recovered Fourier coefficients are useful in distinguishing healthy tissues from tumors in early stages of oesophageal cancer.