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Motivic Atiyah-Segal completion theorem
No full textLet T be a torus, X a smooth separated scheme of finite type equipped with a T -action, and [X/T] the associated quotient stack. Given any localizing A1 -homotopy invariant of dg categories E (homotopy K -theory, algebraic K -theory with coefficients, étale K -theory with coefficients, l -adic algebraic K -theory, l -adic étale K -theory, semi-topological K -theory, topological K -theory, periodic cyclic homology, etc), we prove that the derived completion of E([X/T]) at the augmentation ideal I of the representation ring R(T) of T agrees with the classical Borel construction associated to the T -action o X. Moreover, for certain localizing A1 -homotopy invariants, we extend this result to the case of a linearly reductive group scheme G. As a first application, we obtain an alternative proof of Krishna’s completion theorem in algebraic K-theory, of Thomason’s completion theorem in étale K -theory with coefficients, and also of Atiyah-Segal’s completion theorem in topological K -theory (for those topological M -spaces Xan arising from analytification; M is a(ny) maximal compact Lie subgroup of Gan). These alternative proofs lead to a spectral enrichment of the corresponding completion theorems and also to the following improvements: in the case of Thomason’s completion theorem the base field k no longer needs to be separably closed, and in the case of Atiyah-Segal’s completion theorem the topological M -space Xan no longer needs to be compact and the M -equivariant topological K -theory groups of Xan no longer need to be finitely generated over the representation ring R(M) . As a second application, we obtain new completion theorems in l -adic étale K -theory, in semi-topological K -theory and also in periodic cyclic homology. As a third application, we obtain a description of the different equivariant cohomology groups in the literature (motivic, l-adic, morphic, Betti, de Rham, etc) in terms of derived completion. Finally, in two appendixes of independent interest, we extend a result of Weibel on homotopy K -theory from the realm of schemes to the broad setting of quotient stacks and establish some useful properties of semi-topological K -theory
The new needs friends : Simmelian strangers and the selection of novelty
Get PDFResearch Summary
The paradox of rejecting novel ideas while being motivated to select them exists in many realms. Deviating from prior research that investigated several internal levers to promote the funding of novel ideas in the sciences, we focus on an external lever by investigating how seconded employees increase the selection of novel ideas in two ways: (1) they select more novel ideas themselves, and (2) they influence permanent employees to do the same. Combining unique quantitative longitudinal data and 37 in-depth interviews, we test our predictions in the secondment program at the National Science Foundation and find broad support for our theoretical arguments. Our findings have implications for scholars of science and innovation by proposing a relatively light-touch intervention to facilitate the selection of novel ideas.
Managerial Summary
Organizations often face a paradox: they want to select novel ideas but tend to reject them. This study shifts focus from internal measures to an external solution, examining how seconded employees can help. Through both quantitative data and interviews at the National Science Foundation's secondment program, we found that seconded employees choose more novel ideas and influence permanent staff to do the same. This suggests a simple intervention can significantly boost the acceptance of innovative ideas, offering valuable insights for those in the science and innovation. Understanding this dynamic can empower managers to strategically leverage seconded employees, fostering a more innovative and adaptive organizational culture
Future–present relationship insensitivity : a new perspective on psychological myopia and psychological hyperopia
Get PDFHow much joy versus pain people choose to experience for the present often inversely affects how much joy versus pain they will experience in the future. Do people make choices that maximize their overall happiness? Prior research suggests that people are generally myopic (i.e., over‐choosing joy for the present). We suggest that the prior research may have biasedly focused only on situations in which the future is more important than the present. Rather, people are generally insufficiently sensitive to the relative importance of the present versus the future. When the future is more important than the present, people over‐choose joy for the present, thus appearing myopic, but when the future is less important than the present, people under‐choose joy for the present, thus appearing hyperopic. Six experiments (along with a reason‐exploration study) demonstrate our propositions and show that forcing or nudging people to choose less (more) joy for the present when the future is more (less) important increases their overall happiness. This research challenges the popular view that people are generally myopic, and supports emerging research showing that people are generally situation‐insensitive and can exhibit seemingly opposite biases (e.g., myopia and hyperopia) in different situations
The meeting of Sebastiano Ziani and Alexander III in the Great Council Hall : staging, viewing, and understanding the body politic in Late Sixteenth-Century Venice
No full textCrystal binding (interatomic forces) : ionic bonding and crystals
No full textWe discuss in general terms the models that are appropriate for describing interatomic forces and performing atomistic simulations in ionic materials. In particular we show how the framework of density functional theory (DFT) and second-order perturbation theory provides a unified way of deriving ionic models, including the Born model and shell models, besides variable charge-transfer models, such as charge equilibration models, and the self-consistent tight-binding model. We also discuss progress in the direct numerical fitting of functions to calculated data, which has made significant progress in recent years with the development of machine learning interatomic potentials and other data-driven approaches
The mountains are high and the Emperor is far away : credit scoring and the infrastructure of surveillance capitalism in China
No full textPrevious research on calculative intermediaries shows how these effectively challenge, distort, and disrupt accounting practices in ways that policy-makers might not anticipate. The promises of surveillance capitalism—with its attendant data architectures, datafication processes, and technological sophistication—are different, supposing more accurate ways of reading individuals and greater calculative certainty overall. Yet there is little empirical research to explore how surveillance capitalism manifests itself at the organizational level, either conceptually or operationally. As a result, it remains uncertain whether such specters of omniscience are as haunting in reality as they appear in theory. We explore these themes by way of an ethnographic study into credit scoring in China, showing how intermediary organizations developed a multiplicity of credit scoring models based on machine learning and big data that differed both from original expectations and from each other. These different “renditions” of credit scoring suggest that the data architectures of surveillance capitalism are just as much subject to challenge and adaptation by intermediary organizations as calculative practices such as accounting are in more analog environments
RLS-LCD : an efficient Loop Closure Detection for Rotary-LiDAR Scans
Get PDFLoop closure detection is a crucial technology within the field of simultaneous localization and mapping (SLAM), aiming to mitigate cumulative errors and maintain a globally consistent map. Traditional fixed-LiDAR scans have demonstrated reliable loop closure detection (LCD) performance when employing global descriptors. However, for rotary-LiDAR scans, these methods fall short in place recognition due to significant view-angle changes. To address this challenge, we propose a novel LCD algorithm tailored for rotary-LiDAR scans, named RLS-LCD. Our RLS-LCD approach utilizes submap-based recognition and a novel lightweight global descriptor to mitigate the impact of large view-angle changes inherent to rotary-LiDAR scans. Additionally, we adopt a coarse-to-fine recognition strategy to enhance recall and precision of place recognition in similar structure scenes. The experimental findings unequivocally demonstrate that the RLS-LCD algorithm not only outperforms the contemporary LCD methodologies reliant on global descriptors but also exhibits the capability to execute in real-time on computing platforms with limited computational resources
Distinct biogeographic patterns in Glomeromycotinian and Mucoromycotinian arbuscular mycorrhizal fungi across China : a meta-analysis
No full textFine root endophytes, recently reclassified as Mucoromycotinian arbuscular mycorrhizal fungi (M-AMF), are now recognized as functionally important as Glomeromycotinian AMF (G-AMF). However, little is known about the biogeography and ecology of M-AMF and G-AMF communities, particularly on a large scale, preventing a systematic assessment of ecosystem diversity and functioning. Here, we investigated the biogeographic assemblies and ecological diversity patterns of both G-AMF and M-AMF, using published 18S rDNA amplicon datasets and associated metadata from 575 soil samples in six ecosystems across China. Contrasting with G-AMF, putative M-AMF were rare in natural/semi-natural sites, where their communities were a subset of those in agricultural sites characterized by intensive disturbances, suggesting different ecological niches that they could occupy. Spatial and environmental factors (e.g., vegetation type) significantly influenced both fungal communities, with soil total‑nitrogen and mean-annual-precipitation being the strongest predictors for G-AMF and M-AMF richness, respectively. Both groups exhibited a strong spatial distance-decay relationship, shaped more by environmental filtering than spatial effects for M-AMF, and the opposite for G-AMF, presumably because stochasticity (e.g., drift) dominantly structured G-AMF communities; while the narrower niche breadth (at community-level) of M-AMF compared to G-AMF suggested its more susceptibility to environmental differences. Furthermore, co-occurrence network links between G-AMF and M-AMF were prevalent across ecosystems, and were predicted to play a key role in stabilizing overall communities harboring both fungi. Based on the macroecological spatial scale datasets, this study provides solid evidence that the two AMF groups have distinct ecological preferences at the continental scale in China, and also highlights the potential impacts of anthropogenic activities on distributions of AMF. These results advance our knowledge of the ecological differences between the two fungal groups in terrestrial ecosystems, suggesting the need for further field-based investigation that may lead to a more sophisticated understanding of ecosystem function and sustainable management
Dataset to support: "Quantifying photoluminescence variability in monolayer molybdenum disulfide films grown by chemical vapour deposition"
No full textMonolayer molybdenum disulfide (MoS2) is a promising candidate for inclusion in optoelectronic technologies, owing to its two-dimensional (2D) nature and resultant novel photoluminescence (PL). Chemical vapour deposition (CVD) is an important method for the preparation of large-area films of monolayer MoS2. The PL character of as-prepared monolayer MoS2 must be well understood to facilitate detailed evaluation of any process-induced effects during device fabrication. We comparatively explore the PL emission from four different commercially available CVD-grown MoS2 monolayer films. We characterize the samples via Raman and PL spectroscopy, using both single-spot and mapping techniques, while atomic force microscopy (AFM) is applied to map the surface structure. Via multipeak fitting, we decompose the PL spectra into constituent exciton and trion contributions, enabling an assessment of the quality of the MoS2 monolayers. We find that the PL character varies significantly from sample to sample. We also reveal substantial inhomogeneity of the PL signal across each individual MoS2 film. We attribute the PL variation to non-uniform MoS2 film morphologies that result from the nucleation and coalescence processes during the CVD film development. Understanding the large variability in starting PL behaviour is vital to optimize the optoelectronic properties for MoS2-based devices