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The formation of glacier dirt cones
No full textGlacier dirt cones are meter-scale cones of ice covered with sediment and rock. The cones develop through a process known as differential melt, whereby ice underlying thick debris melts more slowly than bare ice. We report observations of dirt cones on the Kuskulana Glacier, Alaska and develop a model that simulates the growth of dirt cones from debris-filled pits in the ice. With this model, we vary ice melt rates, hillslope debris diffusion rates and pit geometry. Cone heights scale with the square root of debris volume and growth occurs in three distinct stages: emergence, flux-controlled growth and melt-controlled growth. Using dimensional analysis, we derive a characteristic length composed of the ratio of the debris diffusion rate (D) and the bare ice melt rate (b0). Shorter characteristic lengths produce taller, steeper cones. The characteristic length (ℓ = D/b0) determines, in part, the relative duration of each growth stage because it controls debris flux as relief increases. These experiments suggest increasing melt rates and low-mobility debris increase relief on hummocky debris-covered glaciers. Furthermore, the modeling approach demonstrates a method for handling debris transport over an irregular ice surface and could serve as a component in more comprehensive debris-covered glacier models
Political theology
No full textPolitical theology as an approach to International Relations (IR) studies the influence of theological ideas and religious concepts on international relations . In its broader sense, it posits that all politics has theology embedded in it and that politics and theology cannot be separated. Political theology is situated within the wider post-secular turn in political theory and IR. It either makes the genealogical claim that traditional IR concepts, such as anarchy, sovereignty, rights, order, balance of power or perpetual peace, carry the ineradicable trace of their theological origins, or the more ontological claim that religious spirituality is an inescapable and integral dimension of humanity's ethico-political imagination and can thus inspire ethical, critical and more just visions of international and world order. This entry reviews the development of political theology as an approach beyond and within IR and outlines three common approaches to the investigation of political theology within IR
Hadamard domain training with integers for class incremental quantized learning
No full textContinual learning (CL) implemented directly on-device is crucial for practical deployment of applications to battery powered devices, where privacy needs must be balanced with personalization, and agility in adapting to new data. Existing CL techniques can be cost-prohibitive on such devices requiring quantized operations to enable practical deployment. However, as we show commonly used fully quantized training (FQT) solutions do not converge when applied to CL with low-precision hardware. We propose Hadamard Domain Quantized Training (HDQT), that uses the Hadamard transform to facilitate FQT with 4-bit integer operands. HDQT enables low-precision, on-device training where other FQT solutions fail. An examination of gradient alignment reveals that for early feature detection layers, HDQT gradients are better aligned to the unquantized baselines than those generated by other FQT methods. This improved alignment translates to consistently better performance over the course of learning, reflected in the training trajectories through the model loss-landscape. Numerical experiments conducted on Human Activity Recognition (HAR) datasets reveal a ≪ 1% average accuracy reduction across various competitive CL methods, even under aggressive 4-bit quantization with 8-bit accumulators. Additionally, on CIFAR100 there is no loss of accuracy observed when the accumulator precision is relaxed to 12 bits for competitive non-dynamic architecture CL methods
Unpacking the money-distance nexus:mapping the spatial configuration of exogenous entrepreneurial finance across UK entrepreneurial ecosystems
No full textAttention is now increasingly being drawn to the interconnectedness of different entrepreneurial ecosystems (EEs). Consequently, from a theoretical viewpoint EEs are increasingly being viewed from a multi-scaler rather than a mono-scaler perspective. This paper examines the spatial financial interlinkages between places and different forms and stages of entrepreneurial finance. Using a unique real-time data source of equity investments from Crunchbase, we investigate the composition of entrepreneurial finance across 30 different UK spatial locations. The core focus of the work is to uncover the composition of equity deals in terms of non-indigenous international investors and how space plays a role in influencing the prevalence of these extra-local investment deals. A novel dimension of the study is to test the “distance effects'' encountered by locations in terms of their spatial proximity to the UK’s major international hub for entrepreneurial finance: London. We found that the probability of attracting international investors varies significantly across different funding stages with late-stage ventures showing a much higher propensity to attract international investors. By unpacking the “money-distance nexus” a core finding is that proximity to London is crucial for receiving external funding from international investors. Policy implications for less advantageous EEs focus on strategies for leveraging extra-local investment
Education for sustainable development:from disciplinary to transdisciplinary approaches
No full textThe aims of this chapter are to demonstrate that Education for Sustainable Development (ESD) is relevant to all disciplines, to explore how ESD might be integrated into diverse disciplinary programmes and to investigate the ontological and epistemological implications of interdisciplinary and transdisciplinary teaching and learning. The purposes of education at a university require us to prepare learners in all programmes for a complex, uncertain future, and to address inter- and intra-generational justice and environmental limits, whatever the student subject, vocation or employment. We examine illustrative examples from several disciplines and discuss how the sciences, arts and humanities might contribute to critical debates and practical solutions on sustainable development. The emerging discipline of sustainability science is generating a body of literature and learning with which other disciplines can engage, but it is not the exclusive intellectual location of ESD in universities. Increasingly, university programmes have interdisciplinary or transdisciplinary elements which raise epistemological, practical and ethical challenges. We conclude that ESD is essential in all disciplines, but that it cannot be ‘disciplined’ and confined; it can occur in weak forms, and it can stimulate transformative and transgressive learning in any discipline
We all die at the end:Storytelling in the climate apocalypse
No full textAs the ravages of climate change throw our future into question, many of our stories are turning to the subject of extinction. This book is about what they are saying and why it demands our attention
Kronecker classes, normal coverings and chief factors of groups
No full textFor a group G, a subgroup U ≤ G and a group A such that Inn(G) ≤ A ≤ Aut(G) , we say that U is an A-covering group of G if G = ∪a∈AUa. A theorem of Jordan (1872), implies that if G is a finite group, A = Inn(G) and U is an A-covering group of G, then U = G. Motivated by a question concerning Kronecker classes of field extensions, Neumann and Praeger (1990) conjectured that, more generally, there is an integer function ƒ such that if G is a finite group and U is an A-covering subgroup of G, then |G : U| ≤ ƒ(|A : Inn(G)|). A key piece of evidence for this conjecture is a theorem of Praeger [‘Kronecker classes of fields and covering subgroups of finite groups’, J. Aust. Math. Soc. 57 (1994), 17–34], which asserts that there is a two-variable integer function g such that if G is a finite group and U is an A-covering subgroup of G, then |G : U| ≤ g(|A : Inn(G)|,c), where c is the number of A-chief factors of G. Unfortunately, the proof of this theorem contains an error. In this paper, using a different argument, we give a correct proof of the theorem
The logic of dynamical systems is relevant
No full textLots of things are usefully modelled in science as dynamical systems: growing populations, flocking birds, engineering apparatus, cognitive agents, distant galaxies, Turing machines, neural networks. We argue that relevant logic is ideal for reasoning about dynamical systems, including interactions with the system through perturbations. Thus dynamical systems provide a new applied interpretation of the abstract Routley-Meyer semantics for relevant logic: the worlds in the model are the states of the system, while the (in)famous ternary relation is a combination of perturbation and evolution in the system. Conversely, the logic of the relevant conditional provides sound and complete laws of dynamical systems