Obstructions to Pin Structures on Kleinian Manifolds

We develop various topological notions on four-manifolds of Kleinian signature $(- - + +)$. In particular, we extend the concept of `Kleinian metric homotopy' to non-orientable manifolds. We then derive the topological obstructions to pin-Klein cobordism, for all of the pin groups. Finally, we discuss various examples and applications which arise from this work.Comment: 20 pages, Latex, 2 xfigures available from Andrew Chamblin at [email protected]

BOUNDARY CONDITIONS FOR THE SCALAR FIELD IN THE PRESENCE OF SIGNATURE CHANGE

We show that, contrary to recent criticism, our previous work yields a reasonable class of solutions for the massless scalar field in the presence of signature change.Comment: 11 pages, Plain Tex, no figure

Spin Structures on Kleinian Manifolds

We derive the topological obstruction to spin-Klein cobordism. This result has implications for signature change in general relativity, and for the $N=2$ superstring.Comment: 8 page

Initial Value Problems and Signature Change

We make a rigorous study of classical field equations on a 2-dimensional signature changing spacetime using the techniques of operator theory. Boundary conditions at the surface of signature change are determined by forming self-adjoint extensions of the Schr\"odinger Hamiltonian. We show that the initial value problem for the Klein--Gordon equation on this spacetime is ill-posed in the sense that its solutions are unstable. Furthermore, if the initial data is smooth and compactly supported away from the surface of signature change, the solution has divergent $L^2$-norm after finite time.Comment: 33 pages, LaTeX The introduction has been altered, and new work (relating our previous results to continuous signature change) has been include

On metric-connection compatibility and the signature change of space-time

We discuss and investigate the problem of existence of metric-compatible linear connections for a given space-time metric which is, generally, assumed to be semi-pseudo-Riemannian. We prove that under sufficiently general conditions such connections exist iff the rank and signature of the metric are constant. On this base we analyze possible changes of the space-time signature.Comment: 18 standard LaTeX 2e pages. The packages AMS-LaTeX and amsfonts are require

The Link between Engagement and Service Performance: The Mediation Role of Job Satisfaction and Customer-Oriented Behavior

This study investigates the impact of engagement on service performance, both directly and through the mediation role of job satisfaction and customer-oriented behavior, among Small-Medium Enterprises (SMEs) frontline employees. 451 frontline employee data were gathered from SMEs in the greater Bandung region, Indonesia. To examine the hypothesized relationship between variables, the data were assessed using Partial Least Square (PLS). Also, the Bootstrap method was employed to assess job satisfaction and customer-oriented behaviors’ mediation role. The result reinforces the existence of a multi-dimensional engagement concept that encompasses the engagement towards both job and organization. This engagement does not directly influence employee service performance; it is influenced indirectly through job satisfaction and customer-oriented behavior. The managerial practices and theoretical significance of these findings are examined

When humans form media and media form humans: an experimental study examining the effects different digital media have on the learning outcomes of students who have different learning styles

A set of computer-based experiments are reported that investigate the understanding achieved by learners when studying a complex domain (statistics) in a real E-learning environment using three different media combinations – Text only, Text and Diagrams and Spoken Text and Diagrams, and the results agree with earlier work carried out on more limited domains. The work is then extended to examine how student interaction and student learning styles affect the learning outcomes. Different responses to the media combinations are observed and significant differences occur between learners classified as Sensing and Reflective learners. The experiment also identified some important differences in performance with the different media combinations by students registered as Dyslexic. The experiment was therefore repeated with a much larger sample of Dyslexic learners and the earlier effects were found to be significant. The results were surprising and may provide useful guidance for the design of material for Dyslexic students

Challenges of Incorporating Digital Health Technology Outcomes in a Clinical Trial: Experiences from PD STAT.

Digital health technologies (DHTs) have great potential for use as clinical trial outcomes; however, practical issues need to be addressed in order to maximise their benefit. We describe our experience of incorporating two DHTs as secondary/exploratory outcome measures in PD STAT, a randomised clinical trial of simvastatin in people with Parkinson's disease. We found much higher rates of missing data in the DHTs than the traditional outcome measures, in particular due to technical and software difficulties. We discuss methods to address these obstacles in terms of protocol design, workforce training and data management

Challenges of Incorporating Digital Health Technology Outcomes in a Clinical Trial: Experiences from PD STAT

\ua9 2022 - The authors. Published by IOS Press.Digital health technologies (DHTs) have great potential for use as clinical trial outcomes; however, practical issues need to be addressed in order to maximise their benefit. We describe our experience of incorporating two DHTs as secondary/exploratory outcome measures in PD STAT, a randomised clinical trial of simvastatin in people with Parkinson\u27s disease. We found much higher rates of missing data in the DHTs than the traditional outcome measures, in particular due to technical and software difficulties. We discuss methods to address these obstacles in terms of protocol design, workforce training and data management

Sonically-enhanced widgets: comments on Brewster and Clarke, ICAD 1997

This paper presents a review of the research surrounding the paper “The Design and Evaluation of a Sonically Enhanced Tool Palette” by Brewster and Clarke from ICAD 1997. A historical perspective is given followed by a discussion of how this work has fed into current developments in the area