A collaborative filtering similarity measure based on singularities

Recommender systems play an important role in reducing the negative impact of information overload on those websites where users have the possibility of voting for their preferences on items. The most normal technique for dealing with the recommendation mechanism is to use collaborative filtering, in which it is essential to discover the most similar users to whom you desire to make recommendations. The hypothesis of this paper is that the results obtained by applying traditional similarities measures can be improved by taking contextual information, drawn from the entire body of users, and using it to calculate the singularity which exists, for each item, in the votes cast by each pair of users that you wish to compare. As such, the greater the measure of singularity result between the votes cast by two given users, the greater the impact this will have on the similarity. The results, tested on the Movielens, Netflix and FilmAffinity databases, corroborate the excellent behaviour of the singularity measure proposed.     

Fault reconstruction using a LPV sliding mode observer for a class of LPV systems

This paper proposes a new sliding mode observer for fault reconstruction, applicable for a class of linear parameter varying (LPV) systems. Observer schemes for actuator and sensor fault reconstruction are presented. For the actuator fault reconstruction scheme, a virtual system comprising the system matrix and a fixed input distribution matrix is used for the design of the observer. The fixed input distribution matrix is instrumental in simplifying the synthesis procedure to create the observer gains to ensure a stable closed-loop reduced order sliding motion. The ‘output error injection signals’ from the observer are used as the basis for reconstructing the fault signals. For the sensor fault observer design, augmenting the LPV system with a filtered version of the faulty measurements allows the sensor fault reconstruction problem to be posed as an actuator fault reconstruction scenario. Simulation tests based on a high-fidelity nonlinear model of a transport aircraft have been used to demonstrate the proposed actuator and sensor FDI schemes. The simulation results show their efficacy.     

Generation of virtual models of cultural heritage

Different techniques and tools currently exist to generate three-dimensional models of small elements, buildings and cities. Apart from being easier to interpret than two-dimensional drawings, these models facilitate data necessary for reconstruction projects, preservation or rehabilitation of the architectural or archaeological heritage. Traditional surveying only enables us to obtain discrete information of the characteristic lines that define each surface, edge, slope change etc. whereas work with massive capture techniques allows us to obtain continuous points of the surfaces. Photogrammetry or laser scanning combined with conventional photography provides information of the building in addition to its geometry. We carried out a review of the different techniques showing the advantages and disadvantages of each technique as well as the information that can be obtained by applying these techniques to the survey of the great Gate of Antioch in the town of Aleppo, declared a World Heritage Site by UNESCO in 1986, in Syria.     

Fingerspelling and sign language as alternative codes for reading and writing words for Chilean deaf signers

The study examined the role of sign language and fingerspelling in the development of the reading and writing skills of deaf children and youth. Twenty-six deaf participants (13 children, 13 adolescents), whose first language was Chilean Sign Language (CHSL), were examined. Their dactylic abilities were evaluated with tasks involving the reading and writing of dactylic and orthographic codes. The study included three experiments: (a) the identification of Chilean signs and fingerspelled words, (b) the matching of fingerspelled words with commercial logos, and (c) the decoding of fingerspelled words and the mapping of these words onto the writing system. The results provide convergent evidence that the use of fingerspelling and sign language is related to orthographic skills. It is concluded that fingerspelling can facilitate the internal representation of words and serve as a supporting mechanism for reading acquisition.     

Hirsch-type characteristics of the tail of distributions. The generalised h-index

In this paper a generalisation of the h-index and g-index is given on the basis of non-negative real-valued functionals defined on subspaces of the vector space generated by the ordered samples. Several Hirsch-type measures are defined and their basic properties are analysed. Empirical properties are illustrated using examples from the micro- and meso-level. Among these measures, the h-index proved the most, the arithmetic and geometric g-indices, the least robust measures. The μ-index and the harmonic g-index provide more balanced results and are still robust enough.     

A Bourdieusian approach to academic reading: reflections on a South African teaching experience

As in many other parts of the world, ‘academic literacy’ has emerged as both a concern and a contested concept in South African universities. In this article we focus specifically on academic reading, which we argue is a relatively underemphasized aspect of academic literacy. This article is the product of reflections on academic reading during and subsequent to the development and presentation of a postgraduate module presented at Stellenbosch University. It briefly explores the literature on academic literacy; develops the Bourdieusian perspective on academic reading that we used to develop the module; and concludes with a discussion of the module. Our intention was to make ‘reading as social practice’ more visible to students. Bourdieu's concepts of ‘competence’, ‘habitus’ and ‘field’ set the scene for a discussion of the role of reading in different disciples and more generally within the social sciences and humanities.     

Schooling sexualities and gendered bodies. Experiences of LGBT students in Icelandic upper secondary schools

In this paper, we study how Lesbian, Gay, Bisexual and Transgender people (LGBT) students in Icelandic upper secondary schools interpret their experience of heteronormative environment and how they respond to it. The aim is to explore how sexualities and gendered bodies are constructed through ‘schooling’. The article draws on interview data with seven LGBT students who attended five different upper secondary schools. We also use visual data collected during fieldwork at one upper secondary school and exemplify the results with a poster and a digitalised short-film, produced by the students, to substantiate what participants told us in the interviews. All of the students experienced heteronormative discourse and lack of respect and indicated that they did not feel fully accepted in school. Upon entering the classroom, the visibility of LGBTs and discussion about different performances of gender and sexuality seem to disappear, whether in terms of textbooks, course content, teaching practices and school environment. Furthermore, LGBTs and those who do not conform to the hegemonic performances of gender are often constructed as deviations from the norm, strange, and even depicted as the abjected other. This applies in particular to the informal school, which embraces the traditions, culture and social interactions among students and teachers. This othering occurs, despite relatively positive attitudes towards LGBT people in Icelandic society in general. The results signify a gap between policy and practice as regards the positioning of LBGT students, which affects their schooling and well-being.     

Home book reading and reading achievement in EU countries: the Progress in International Reading Literacy Study 2011 (PIRLS)

Home shared book reading during the preschool years is a strong predictor of students’ reading achievement in primary school, and, according to Sénéchal (2012), it can benefit more children from low socioeconomic status (SES) backgrounds. This study examines the association between frequency of book reading before the start of compulsory education and the reading achievement of 4th-grade students whose parents have high and low education levels in 22 European countries. Using data from the Progress in International Reading Literacy Study (PIRLS 2011), we show that the contribution of shared reading for the achievement of students from distinct SES backgrounds is different in different countries and that shared reading does not always benefit more children from low-SES backgrounds. Results are discussed in light of Sénéchal's home literacy model, the dynamics of cultural capital, and current policy efforts to support children's literacy development in European countries.     

Analysing sexual experiences through ‘scenes’: a framework for the evaluation of sexuality education

This paper describes an alternative approach to undertaking and evaluating sexual health promotion, focusing on the notion of sexual scenes and scenarios and how these can provide a vantage point from which to examine sexual experience. The concept of sexual scenes provides a context within which to analyse many of the behavioural and epidemiological factors associated with sexual practice. In principle, such an approach provides a tool for conscientization, action and the invention of novel group and individual repertoires that may result in individual and social mobilization for health and/or sexual and reproductive rights. Scenes can be elicited through individual interviews, group interviews and discussions, or through staged and dramatized performance and students' writing. Analysing sexual scenes offers an entry point for dialogue in sexual health promotion programming. Evaluation of these programmes can be part of the process of changing sexual scenarios. Change is witnessed not only through individual changes but, especially in impoverished communities, through challenges to dominant local sexual scenarios and engagement with structural concerns.