Landscape as framework for integrating local subsistence and ecotourism: a case study in Zimbabwe

Ecotourism can be a solution for mitigating the negative environmental and socio-economic impacts of new developments in fragile environments. Before planning an ecotourist project, it is necessary to consider an area that not only covers the margins of the development zone, but also a wider perimeter of physically and culturally related landscape parts. This paper describes an approach to the demarcation and analysis of an expanded zone around a new reservoir near Bulawayo, larger than an originally designated narrow natural fringe. The concept gains in many ways, in landscape diversity, in cultural assets and in interaction with local residents to whom ecotourisms should be profitable in the first place.     

VLES Modelling with the Renormalization Group

In a Very-Large-Eddy Simulation (VLES), the filterwidth-wavenumber can be outside the inertial range, and simple subgrid models have to be replaced by more complicated ('RANS-like') models which can describe the transport of the biggest eddies. One could approach this by using a RANS model in these regions, and modify the lengthscale in the model for the LES-regions[1-3]. The problem with these approaches is that these models are specifically calibrated for RANS computations, and therefore not suitable to describe inertial range quantities. We investigated the construction of subgrid viscosity and transport equations without any calibrated constants, but these are calculated directly form the Navier-Stokes equation by means of a Renormalization Group (RG) procedure. This leads to filterwidth dependent transport equations and effective viscosity with the right limiting behaviour (DNS and RANS limits).     

Investigating the relationship between success factors and student participation in online and blended learning in adult education

Online and blended learning (OBL) is valued, but it also offers challenges. Literature indicates that OBL can enhance access to education and increase flexibility for students. However, the reported dropout rates indicate that student participation in OBL programmes is a concern. Scientifically valid knowledge about how factors that help students participate in OBL are related to student participation is necessary for quality improvement of OBL. This knowledge can help professionals determine what they need to improve in their institution and how to prioritize those improvements. In this study, we report on the validation of a quality instrument with indicators related to quality dimensions present in quality management frameworks and important success factors that aid student participation in OBL. These success factors are as follows: credibility, transparency, flexibility, accessibility, interactivity, personalization, and productivity. The partial least squares structural equation modelling (PLS‐SEM) method is suitable for validating complex models in studies where predictive accuracy is important. According to adult students, all success factors, except flexibility, are important for aiding OBL participation. Adult students perceive that the quality dimensions of learning activities and student support (related to interactivity) deserve priority in improving participation in OBL in adult education.     

Size-dependent dissociation of small cobalt clusters on ultrathin NaCl films

Mass-selected anionic cobalt clusters of two different sizes (Co2 and Co13) were deposited onto ultrathin NaC1 films grown on an Au(111) substrate.Using scanning tunneling microscopy experiments and density functional theory simulations,we show that the deposited Co2 cluster dissociates and that the resulting Co atoms dope the NaCl surface by substituting Na ions.In contrast,the larger Co13 cluster does not dissociate and remains stable on top of the NaC1 film.The sizedependent fragmentation of clusters is an important aspect in the understanding of the chemical interaction between size-selected small aggregates of atoms and supporting surfaces.     

An open book on Facebook? Examining the interdependence of adolescents’ privacy regulation strategies

Users of social network sites (SNSs) use three main strategies that help to manage the privacy of their profile information: (1) limiting the level of data revealed, (2) using privacy settings to exert control over data and (3) audience/friendship management by being restrictive about whom to accept as a ‘friend’. Extant research does not show whether these strategies operate as independent mechanisms or whether they are interdependent and work as a system. Given what offline privacy theorist Irwin Altman (1977 Altman, Irwin. 1977. “Privacy Regulation: Culturally Universal or Culturally Specific?” Journal of Social Issues 33 (3): 66–84. doi: 10.1111/j.1540-4560.1977.tb01883.x[Crossref], [Web of Science ®] , [Google Scholar]) designates as the multi-mechanic nature of privacy protection, we test a model in which we expect to find that the three discerned strategies are related to one another. Structural equation modelling analysis performed on the subsample (n?=?1564) of our study’s data – collected among 1743 adolescents by means of a paper-and-pencil survey – demonstrates that, in line with Altman’s vision of privacy protection, the three discerned strategies effectively operate as an interdependent system. In congruence with the hypotheses derived from extant research, we found that adolescents’ level of disclosure influences adolescents’ involvement in the two other discerned strategies: Adolescents with high levels of personal information disclosure share an increased tendency to have many friends on SNSs and a lower level of using privacy settings.     

Dynamic task allocation for multi-robot search and retrieval tasks

Many application domains require search and retrieval, which is also known in the robotic domain as foraging. For example, in a search and rescue domain, a disaster area needs to be explored and transportation of survivors to a safe area needs to be arranged. Performing such a search and retrieval task by more than one robot increases performance if they are able to distribute their workload efficiently and evenly. In this work, we study the Multi-Robot Task Allocation (MRTA) problem in the search and retrieval domain, where a team of robots is required to cooperatively search for targets of interest in an environment and also retrieve them back to a home base. In comparison with typical foraging tasks, we look at a more general search and retrieval task in which the targets are distinguished with various types, and task allocation also requires taking into account temporal constraints on the team goal. As usual, robots have no prior knowledge about the location of targets in the environment but in addition they need to deliver targets to the home base in a specific order according to their types, which significantly increases the complexity of a foraging problem. We first use a graph-based model to analyse the search and retrieval problem and the dynamics of exploration and retrieval within a cooperative team. We then proceed to present an extended auction-based approach, as well as a prediction approach. The essential difference between these two approaches is that the task allocation and execution procedures in the auction approach are running in parallel, whereas a robot in the prediction approach only needs to choose a task to perform when it has no thing to do. The auction approach uses a winner determination mechanism to allocate tasks to each robot, whereas the robots in the prediction approach implicitly coordinate their activities by team reasoning that leads to consensuses about task allocation. We use the Blocks World for Teams (BW4T) simulator to evaluate the two approaches in our experimental study.     

‘You talking to me?’ The influence of peer communication on adolescents’ persuasion knowledge and attitude towards social advertisements

This article examines how peer communication among adolescents (14–16 years) affects the evaluation of social advertising (i.e. targeted ad that adopts the social proof heuristic by using an individual’s social ties as endorsers for a brand) on social networking sites (SNSs). More precisely, the focus lies on how engaging in online peer chatting on these social platforms alters persuasion knowledge and attitude towards the ad. In order to test this, two between-subjects experiments were conducted in which adolescents chatted with peers on a mock SNS that contained a social ad. In Experiment 1, results reveal that a social ad generates a more positive attitude among adolescents when they have engaged in online peer communication, and at the same time, triggers less persuasion knowledge. In Experiment 2, the depth of the relationship between the chatters (tie strength) plays a significant moderating role as peer communication with strong ties yields greater effects, compared to communication with weak ties. These findings reveal important social influence dynamics that may alter the elaboration of persuasive communication, leading to valuable theoretical and practical implications.