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.     

Coherence in professional education: does it foster dedication and identification?

This article examines the impact of professional education on students' dedication to and identification with a profession. The premise is that professional education is not only about knowledge acquisition and reasoning but also about attitudes and aspirations. In fostering dedication and identification, students' experiences of relevance seem to be important. The concept of coherence seen as an expression of relevance is introduced and measured by four kinds of interactions: Theory–practice interaction, teacher–student interaction, peer interaction and supervisor–student interaction. Analysis indicates that coherence, particularly as theory–practice interaction, peer interaction and supervisor–student interaction, has a significant impact on dedication to and identification with a profession. Longitudinal survey data – collected from students in colleges for teaching, nursing and social work – are analysed.     

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.     

Parental perspectives of the role of school factors in school refusal

The aim of this study was to explore parents’ perspectives on the role of school factors in school refusal (SR). Semi-structured interviews were conducted with 17 parents who had experienced SR with their own child. They identified several school factors related to SR. Some of these findings suggest that students who are prone to SR need more predictability and more teachers’ support than they sometimes get in school. Their need for predictability seems to occur particularly during less structured activities and during transitions in school. Findings also imply that disruptive behavior among classmates and harsh management from teachers affects perceived predictability and support for SR-prone students. All parents expressed concern about bullying, and roughly a third of them reported that their child had been a victim of bullying. Insufficient adaptation of schoolwork was also mentioned relatively frequently. Parents emphasized that adaptation of schoolwork needs to be done in close cooperation with the student and parents to avoid negative differentiation from classmates or stigma. Finally, several parents commented that teachers and schools need more knowledge about SR and felt that schools needed a more coordinated approach to supporting students who are at risk of SR.     

Culture and Technology: implications for multicultural teacher education

ABSTRACT

American classrooms are experiencing a rapid growth in cultural and ethnic diversity, as well as an increase in educational classroom computing. Because culture directly affects classroom organisation and classroom learning, teachers need to understand, incorporate, and support their students’ cultures. Furthermore, since educational computing is not culturally neutral, teachers in culturally diverse settings must integrate the computer culture, the classroom culture, and students’ learning preferences. To meet the need for culturally and technologically competent multicultural teachers, teacher education programs must first define both cultural competency and computer competency. After examining the relationship between culture and educational computing, the paper explores some essential components of cultural and technological competency for multicultural teachers. Finally, it indicates the need for further research on the interaction of culture and technology in the multicultural classroom.