Using matrix norms to estimate the direction of arrival of planar waves on an ULA

SEAD method estimates the direction-of-arrival angles on an uniform linear array based on the difference between the two largest singular values, what is called differential spectrum. Although it presented an outstanding performance, the ability to indicate the source positions was not elucidated yet. Inspired by the differential spectrum formulation we derived a total differential spectrum and found out that the matrix norm induced by the vector 2-norm of a modified spatial covariance matrix can be used to estimate the direction-of-arrival of multiple plane waves. Indeed we show that matrix norms are estimators and we propose their use instead of the singular value decomposition in SEAD-based methods. We present a general mathematical expression in order to explicit the operating principles of the proposed methods. Consequently, we were able to explain how the relation between the arriving and the search angles produces the larger peaks on the differential spectrum. To evaluate the important role played by matrix norms, a thousand experiments were carried out. They showed that the proposed approach proved to be as accurate as the previous SEAD-based methods, while providing a significant reduction on runtime. It also outperformed well-established methods like MODEX regarding the estimation error.     

Issues and agency: postgraduate student and tutor experiences with written feedback

This paper examines the issues which postgraduate students and tutors experienced as they engaged in receiving, providing and requesting feedback, as well as the strategies which they adopted as they sought resolution of these issues. The study employed a case study approach, using data obtained from semi-structured and stimulated recall interviews with students and staff from three discipline areas at one university in the UK. The findings reinforce the conclusions that have been drawn in a number of previous studies in terms of the sources of dissatisfaction emerging from individual interactions and institutional practices. Additionally, however, the results expand on our current understanding of feedback and agency in higher education by illustrating how participants sought out imaginative solutions to the challenges they experienced, in order to enhance the effectiveness of the feedback process. The diversity of the strategies used provides evidence of student and tutor agency, and has implications for current feedback practices and future research in this area.     

Being our best: Understanding the relationship between empowerment and employee engagement among midlevel student affairs professionals

Over the last few decades, there has been a significant increase in the number of student service personnel, yet demand has outstripped this growth leading to turnover and low employee satisfaction. Scholars and practitioners alike have called for increased levels of empowerment of these workers, but the outcomes of this approach need further analysis. We utilize data from a survey of international centre directors in the United States and employ a partial least squares-based structural equation modelling to investigate the relationship between empowerment and employ perceptions including work satisfaction, organizational commitment, perspective of leadership and personal engagement. Specifically, trust meaning and personal consequence are strong components of empowerment in this sample. Our results indicate a positive relationship between empowerment and job satisfaction, organizational commitment and perspectives on leadership. In addition, we find that organizational commitment mediates the relationship between empowerment and personal engagement.     

Inequality of educational opportunity: the relationship between access,affordability, and quality of private schools in Lagos,Nigeria

Using data from a census of private schools in one of Lagos, Nigeria’s administrative jurisdictions, this paper explores the linkages between a heterogeneous sector of private schools and issues of school access, affordability, quality, and ultimately social mobility for households at the bottom of the income distribution. Although a large private education market has buoyed Lagos’s growth towards near-universal primary enrolment, this heterogeneous school sector appears to be providing socially stratifying paths towards educational attainment. We apply Lucas’s theory of effectively maintained inequality to assess the extent to which access to higher quality education services within the private sector is determined by cost. We find that higher-cost private schools provide students with greater opportunities to study in institutions with higher quality inputs and increased potential for progression within the educational system. As such, it is highly likely that these schools are primarily accessible to students at the upper ends of the income distribution.     

Exploring the perspectives of physically active and inactive adolescents: how does physical education influence their lifestyles?

Based on a socio-ecological framework for physical education (PE), this study explored and analysed the perspectives of physically active and inactive adolescent boys and girls with different socioeconomic status (SES), regarding the meanings that PE had on their physical activity (PA) lifestyles throughout childhood and adolescence. An interpretative and qualitative design was adopted and operationalised through an individual two-hours in-depth interview. Thematic analysis identified five main themes that distinguish active from inactive adolescents: ‘Early experiences of PE at primary school’; ‘PE experiences in middle and secondary school’; ‘Friendly, professional and pedagogue. That’s what I want from my PE teacher’; ‘Friends in PE and PA’; ‘Active lifestyles? Are schools and PE ready for making a difference?…’. Regardless of the lifestyle, girls revealed more PE negative experiences, related to uninteresting and competitive activities, groups’ constitution and logistic factors. SES played a major role on their PA and PE experiences, with low SES adolescents having limited opportunities inclusively within the primary school PE context. This study provides evidence for the importance of promoting positive PE and PA experiences in early years. Based on adolescents’ voices, several recommendations are discussed that can be considered for improving PE professionals’ effectiveness in promoting active lifestyles.