We present two approaches towards a characterization of the complete Pick property. We first discuss the lurking isometry method used in a paper by J.A. Ball, T.T. Trent, and V. Vinnikov. They show that a nondegenerate, positive kernel has the complete Pick property if $1/k$ has one positive square. We also look at the one-point extension approach developed by P. Quiggin which leads to a sufficient and necessary condition for a positive kernel to have the complete Pick property. We conclude by connecting the two characterizations of the complete Pick property. / Master of Science

The increasing importance of informal relationships derives from the steadily evolving and proceeding conditions in which we are involved in on a daily basis. These conditions range from the overall environment we are living in, over to our organizational working context and end up in our very own personal setting, namely our minds: in the end, we as human beings are the primary cause for the forming of such relationships, as they are established through our needs, concerns, wishes and fears. Furthermore, we are also highly influenced by our surrounding conditions, and so are the causes, types and effects of the so formed relationships. Our research offers an analytical as well as personal approach to bring the increasing importance of informal relationships to the minds of our readers. Especially leading figures in various organizational contexts are our target audience, as they have to cope with the also growing responsibilities and requirements that are accompanied by this process. Among scholars of this research field, there are many terms and expressions existing of such informal elements and happenings. Some speak of them as the ‘hidden assets’ of organizations, others entitle them as their ‘underlying powers’ and there also exist highly analytical notations, like for example ‘secondary adjustments’. However, all of them cannot entirely reproduce the thoughts and feelings we connect with our work. As we are now acting within the circle of these scholars, we take the liberty to add our own expression, which is best able to demonstrate our perception of such informal forces. We have given them the term ‘Lurking Lions’. They are powerful but also hard to encounter, as they are very well hidden behind the bushes of the formal organization and present without any noise. However, if our entitled lions realize some changes, threats or incentives in their environment, they are likely to reveal themselves and exert a drastic influence on the ones who caused them. By getting in contact with them, most people are likely to be overwhelmed as no one really knows about their thoughts, intentions and upcoming actions. Therefore, we tempt you to listen carefully, observe deeply and find out the nature of these ‘Lurking Lions’. By doing so, you can get a new powerful informal ally on your side.

Brand-lurking Phenomenon on Social Media Abstract The key measures to assess consumer-brand engagement on social media have mainly been visible interactions with media content, including 'likes', comments and shares. However, as research into consumers' online behaviour demonstrates, only a minority of users in fact participate 'visibly'. On social media, the vast majority of users are passive participants, so called 'lurkers'. This thesis explores consumers' publicly invisible behaviours on social media and introduces an original methodological approach to exploring the otherwise invisible behavioural patterns on social media, which builds on ethnographic principles and combines digital methods with qualitative methods. Drawing on a data set of 134 hours of screen recordings obtained through ad hoc tracking devices installed on PCs and smartphones of 15 young adults from seven European countries recruited from the "Generation Z" and 15 in- depth interviews conducted with the same participants, the study proposes the following contributions. First, the thesis illustrates a research protocol to explore consumers' lurking behaviours in relation to branded content as they occur within the young people's natural social media settings. Second, it introduces the concept of invisible engagement, defined as an...

<p dir="ltr">Broadly, the focus of this work is on efficient statistical estimation and optimization of data arising from experimental data, particularly motivated by nanomanufacturing experiments on the material tellurene. Tellurene is a novel material for transistors with reliable attributes that enhance the performance of electronics (e.g., nanochip). As a solution-grown product, two-dimensional (2D) tellurene can be manufactured through a scalable process at a low cost. There are three main throughlines to this work, data augmentation, optimization, and equality constraint, and three distinct methodological projects, each of which addresses a subset of these throughlines. For the first project, I apply transfer learning in the analysis of data from a new tellurene experiment (process B) using the established linear regression model from a prior experiment (process A) from a similar study to combine the information from both experiments. The key of this approach is to incorporate the total equivalent amounts (TEA) of a lurking variable (experimental process changes) in terms of an observed (base) factor that appears in both experimental designs into the prespecified linear regression model. The results of the experimental data are presented including the optimal PVP chain length for scaling up production through a larger autoclave size. For the second project, I develop a multi-armed bandit Bayesian optimization (BO) approach to incorporate the equality constraint that comes from a mixture experiment on tellurium nanoproduct and account for factors with categorical levels. A more complex optimization approach was necessitated by the experimenters’ use of a neural network regression model to estimate the response surface. Results are presented on synthetic data to validate the ability of BO to recover the optimal response and its efficiency is compared to Monte Carlo random sampling to understand the level of experimental design complexity at which BO begins to pay off. The third project examines the potential enhancement of parameter estimation by utilizing synthetic data generated through Generative Adversarial Networks (GANs) to augment experimental data coming from a mixture experiment with a small to moderate number of runs. Transfer learning shows high promise for aiding in tellurene experiments, BO’s value increases with the complexity of the experiment, and GANs performed poorly on smaller experiments introducing bias to parameter estimates.</p>

Indiana University-Purdue University Indianapolis (IUPUI) / In the fields of formal and informal online adult education, the absence of a social context for instruction has been found to present significant limitations for learner persistence and retention. In the field of online psychoeducational intervention, self-administered and self-paced individualized prevention programs have been developed for delivery to large populations of anonymous users. These delivery models provide limited social context for instructional activities, due in part to the anonymity of their participants. When social interaction is included in their prevention programs through voluntary, asynchronous self-help/mutual aid discussion forums, anonymity may still limit social interaction, in favor of observational learning advantages for self-efficacy appraisals derived from "lurking". When these large-group models have been applied to online psychoeducation intervention programs for the purposes of encouraging mutual aid, interactive participation has been limited. This mixed methods study focused on a model for the design of an online small group psychoeducational intervention that integrated individual and social learning in a parent management training program. Self-paced participation was replaced with facilitator-led participation in an asynchronous discussion forum where topics were prioritized and sequenced with learning content from individual web-based training modules. Social interaction was facilitated through online problem-based learning discussion group. Despite assertions that interactive participation in online psychoeducational discussion forums may only be accomplished once a subscriber threshold of several hundred participants has been reached, this study found that small group participation through the program's integrated design resulted large effects for increases in parent self-agency and reduction of over-reactive, coercive parenting behaviors. Participation in the online problem-based group discussion forum was found to have contributed to participant outcomes when posting characteristics revealed the presence of both mutual aid processes and the application of individual learning module content.