2,362 research outputs found
Modeling Transnational Terrorists\u27 Center of Gravity: An Elements of Influence Approach
Since the September 11th terrorist attack, there has been an increased emphasis on understanding and modeling terrorists groups. While several efforts have focused on identifying transnational terrorists\u27 centers of gravity (COGs), most of these efforts have proposed COGs using a traditional nation-state paradigm. In today\u27s global village , terrorist groups are no longer limited by locality and national boundaries. With the increasing threats from transnational terrorist groups, new paradigms and models are necessary to properly analyze today\u27s, and tomorrow\u27s, conflict. Analysis should be based on the identified and quantified transnational terrorists\u27 COGs and their associated interactions. Unfortunately, not all of the transnational terrorists\u27 COGs and their interconnected cause and effect relationships are fully known or understood. This research effort suggests a single COG, Public Support as the transnational terrorists\u27 key driver. An influence diagram-like approach was used to collect, organize, and display the COG and its key elements of value. These qualitative influence diagrams serve as a basis to develop a system dynamics model where quantitative measures were applied to the interactions. A prototype model capable of capturing and utilizing time-persistent and higher order effects that provides insight to decision makers regarding alternative strategic policies and courses of action (COA) against transnational groups has been developed and illustrated against a notional transnational terrorist group
A material-dialogic perspective on powerful knowledge and matter within a science classroom
âPowerfulâ disciplinary knowledge has the potential to enrich studentsâ lives by providing access to understanding beyond everyday experience (Young 2011). Learning science or any other school subject requires understanding of the core body of content within an academic discipline. However, contemporary discussion of disciplinary knowledge remains at the sociological level, offering little clarity around how such knowledge manifests in the complex and unique contexts in which people learn. The framing of powerful knowledge inherits a dualist philosophical assumption that a curriculum concept is a universal phenomenon, acquired through a myriad of activities and applied in new situations, but nevertheless something which is acquired (or not) (Hardman, 2019). The question then becomes how these universal concepts are acquired through the unique context of a specific classroom.
Gericke et al. (2018) begin to address this question by highlighting the transformations made as disciplinary knowledge is taught in schools. These transformations occur at the societal, institutional and classroom levels. The term âtransformationâ is an umbrella term reflected in both the tradition of didactics, for example, âdidactic transpositionâ (Chevallard 2007), âomstillingâ (Ongstad 2006) and âreconstructionâ (Duit 2013), as well as within the curriculum tradition in Bernsteinâs (1973) notion of âre-contextualizationâ. As well as considering transformations, the term epistemic quality moves us towards conceptualizing how classroom activities have differing qualities in conveying the epistemology of disciplines (Hudson, 2018). In this chapter, we focus on the classroom, and seek to address the overarching question of:
How can the transformation processes related to powerful knowledge and epistemic quality be described?
Our contention is that the notions of transformation and epistemic quality hold the potential to frame the ways in which disciplinary knowledge and epistemology manifest in the classroom. However, as these notions are being developed, in this book and elsewhere, we wish to guard against any simplistic framing whereby idealised disciplinary understandings are in some way represented in classrooms. In our view, a learner does not receive a reduced, simplified form of some universal understanding. Understanding of a subject discipline, in terms of both knowledge and the epistemology of the discipline, emerge from the dynamic, messy and material contexts of classrooms. In this chapter, we consider how a material-dialogic frame (Hetherington et al. 2018; Hetherington and Wegerif, 2018) might contribute to this discussion. We first briefly lay out the material-dialogic frame and our reasons for proposing it. After that, we use a case study of a science classroom to support the usefulness of the frame in considering transformations of disciplinary knowledge in classrooms
Computational challenges of systems biology
Progress in the study of biological systems such as the heart, brain, and liver will require computer scientists to work closely with life scientists and mathematicians. Computer science will play a key role in shaping the new discipline of systems biology and addressing the significant computational challenges it poses
Surveyor batteries Final engineering report
Design and performance of Surveyor spacecraft silver-zinc main batter
Investigating and promoting trainee science teachersâ conceptual change of the nature of science with digital dialogue games âInterLocâ
The purpose of this study is to explore how an online-structured dialogue environment supported (OSDE) collaborative learning about the nature of science among a group of trainee science teachers in the UK. The software used (InterLoc) is a linear text-based tool, designed to support structured argumentation with openers and âdialogue movesâ. A design-based research approach was used to investigate multiple sessions using InterLoc with 65 trainee science teachers. Five participants who showed differential conceptual change in terms of their Nature of Science (NOS) views were purposively selected and closely followed throughout the study by using key event recall interviews. Initially, the majority of participants held naĂŻve views of NOS. Substantial and favourable changes in these views were evident as a result of the OSDE. An examination of the development of the five participantsâ NOS views indicated that the effectiveness of the InterLoc discussions was mediated by cultural, cognitive, and experiential factors. The findings suggest that InterLoc can be effective in promoting reflection and conceptual change.InterLoc was developed by a team led by Andrew Ravenscroft with
funding from the UK JISC (Joint Information Systems Committee) 'e-learning tools'
programme, and from the JISC Capital Programme
The portion size effect : women demonstrate an awareness of eating more than intended when served larger than normal portions
Large portion sizes lead to increased intake. Some studies suggest that individuals are unaware that they consume more when served larger portions. In a between-subjects design we asked female participants (NâŻ=âŻ48) how much pasta and tomato sauce they intended to consume for lunch prior to eating. We then provided a smaller or a larger portion of the same food and invited participants to self-serve a portion into a second bowl (same size in both conditions). After eating until comfortably full, participants were shown an image of the amount they had selected at the beginning of the meal. They were then asked whether they perceived having eaten more or less than this amount, and by how much more or less they had eaten. In total 46 responses were analysed. Of the participants who received the large portion and who ate more than intended, 77% (pâŻ=âŻ.029) correctly identified eating more. However, when participants were asked to indicate by how much they had eaten above or below their intended amount, those who ate more after receiving a larger portion underestimated their intake by 25% (pâŻ=âŻ.003). These findings suggest that greater intake from a larger portion is associated with an awareness of having eaten a large quantity combined with a failure to register the actual amount consumed (in the direction of underestimation). The latter might be attributed to an error associated with the visual estimation of volume
MAGRITTE: a new multidimensional accelerated general-purpose radiative transfer code
Magritte is a new deterministic radiative transfer code. It is a ray-tracing code that computes the radiation field by solving the radiative transfer equation along a fixed set of rays for each grid cell. Its ray-tracing algorithm is independent of the type of input grid and thus can handle smoothed-particle hydrodynamics (SPH) particles, structured as well as unstructured grids. The radiative transfer solver is highly parallelized and optimized to have well scaling performance on several computer architectures. Magritte also contains separate dedicated modules for chemistry and thermal balance. These enable it to self-consistently model the interdependence between the radiation field and the local thermal and chemical states. The source code for Magritte will be made publically available at github.com/Magritte-code
Nurse rock microclimates significantly buffer exposure to freezing T temperature and moderate summer temperature
Nurse tree canopies mitigate exposure to freezing temperatures that could result in injury or mortality to the saguaro cactus (Carnegiea gigantea). Abiotic objects have been hypothesized to provide similar beneficial microclimates. We used data loggers at 11 nurse rock sites to record daily daytime summer maximum and winter nighttime minimum temperatures at Saguaro National Park, Arizona, to examine the effectiveness of rocks to moderate seasonal temperature extremes in the microclimate. Temperatures at rock sites averaged 2 °C warmer than exposed open control sites in winter. We found that the efficiency of rocks to act as insulators significantly increased as temperature at control sites decreased, consistent with studies of tree canopies, and that the insulation effect lasted throughout the night. In summer, rocks reduced exposure to maximum temperatures but did not offer significantly more cooling at higher temperatures. Our results suggest that the protection from freezing temperature offered by rocks in winter is more ecologically beneficial to the saguaro than extreme temperature amelioration during summer in the cold-limited frontiers of the speciesâ range
Characterization of the glass transition in vitreous silica by temperature scanning small-angle X-ray scattering
The temperature dependence of the x-ray scattering in the region below the
first sharp diffraction peak was measured for silica glasses with low and high
OH content (GE-124 and Corning 7980). Data were obtained upon scanning the
temperature at 10, 40 and 80 K/min between 400 K and 1820 K. The measurements
resolve, for the first time, the hysteresis between heating and cooling through
the glass transition for silica glass, and the data have a better signal to
noise ratio than previous light scattering and differential thermal analysis
data. For the glass with the higher hydroxyl concentration the glass transition
is broader and at a lower temperature. Fits of the data to the
Adam-Gibbs-Fulcher equation provide updated kinetic parameters for this very
strong glass. The temperature derivative of the observed X-ray scattering
matches that of light scattering to within 14%.Comment: EurophysicsLetters, in pres
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