cssi/SciSciGPT-SciSciNet huggingface dataset:
Quiver varieties and symmetric pairs

We study fixed-point loci of Nakajima varieties under symplectomorphisms and their anti-symplectic cousins, which are compositions of a diagram automorphism, a reflection functor and a transpose defined by certain bilinear forms. These subvarieties provide a natural home for geometric representation theory of symmetric pairs. In particular, the cohomology of a Steinberg-type variety of the symplectic fixed-point subvarieties is conjecturally related to the universal enveloping algebra of the subalgebra in a symmetric pair. The latter symplectic subvarieties are further used to construct geometrically an action of a twisted Yangian on torus equivariant cohomology of Nakajima varieties. In type $A$ case, these subvarieties provide a quiver model for partial Springer resolutions of nilpotent Slodowy slices of classical groups and associated symmetric spaces, which leads to a rectangular symmetry and a refinement of Kraft-Procesi row/column removal reductions.
Hilbert schemes and multiple q-zeta values

We present several conjectures on multiple q-zeta values and on the role which they play in certain problems of enumerative geometry.
Subsets of Rectifiable curves in Hilbert Space-The Analyst's TSP

We study one dimensional sets (Hausdorff dimension) lying in a Hilbert space. The aim is to classify subsets of Hilbert spaces that are contained in a connected set of finite Hausdorff length. We do so by extending and improving results of Peter Jones and Kate Okikiolu for sets in ℝd. Their results formed the basis of quantitative rectifiability in ℝd. We prove a quantitative version of the following statement: a connected set of finite Hausdorff length (or a subset of one), is characterized by the fact that inside balls at most scales aroundmost points of the set, the set lies close to a straight line segment (which depends on the ball). This is done via a quantity, similar to the one introduced in [Jon90], which is a geometric analogue of the Square function. This allows us to conclude that for a given set K, the l2 norm of this quantity (which is a function of K) has size comparable to a shortest (Hausdorff length) connected set containing K. In particular, our results imply that, with a correct reformulation of the theorems, the estimates in [Jon90, Oki92] are independent of the ambient dimension.
Twisted Gross–Zagier Theorems

The theorems of Gross-Zagier and Zhang relate the Neron-Tate heights of complex mul- tiplication points on the modular curve X0(N) (and on Shimura curve analogues) with the central derivatives of automorphic L-function. We extend these results to include certain CM points on mod- ular curves of the form X( 0(M) ∩ 1(S)) (and on Shimura curve analogues). These results are mo- tivated by applications to Hida theory that can be found in the companion article "Central derivatives of L-functions in Hida families", Math. Ann. 399(2007), 803-818.
On finite free Fisher information for eigenvectors of a modular operator

Abstract Suppose M is a von Neumann algebra equipped with a faithful normal state φ and generated by a finite set G = G ⁎ , | G | ≥ 2 . We show that if G consists of eigenvectors of the modular operator Δ φ with finite free Fisher information, then the centralizer M φ is a II 1 factor and M is either a type II 1 factor or a type III λ factor, 0 λ ≤ 1 , depending on the eigenvalues of G. Furthermore, ( M φ ) ′ ∩ M = C , M φ does not have property Γ, and M is full provided it is type III λ , 0 λ 1 .
Mechanism design for fair allocation

Mechanism design for a social utility being the sum of agents' utilities (SoU) is a well-studied problem. There are, however, a number of problems of theoretical and practical interest where a designer may have a different objective than maximization of the SoU. One motivation for this is the desire for more equitable allocation of resources among agents. A second, more subtle, motivation is the fact that a fairer allocation indirectly implies less variation in taxes which can be desirable in a situation where (implicit) individual agent budgetary constraints make payment of large taxes unrealistic. In this paper we study a family of social utilities that provide fair allocation (with SoU being subsumed as an extreme case) and derive conditions under which Bayesian and Dominant strategy implementation is possible. Furthermore, it is shown how a simple modification of the above mechanism can guarantee full Bayesian implementation. Through a numerical example it is shown that the proposed method can result in significant gains both in allocation fairness and tax reduction.
Short-Range, Spin-Dependent Interactions of Electrons: A Probe for Exotic Pseudo-Goldstone Bosons

We used a torsion pendulum and rotating attractor with 20-pole electron-spin distributions to probe dipole-dipole interactions mediated by exotic pseudo-Goldstone bosons with m(b)c(2)≤500 μeV and coupling strengths up to 14 orders of magnitude weaker than electromagnetism. This corresponds to symmetry-breaking scales F≤70 TeV, the highest reached in any laboratory experiment. We used an attractor with a 20-pole unpolarized mass distribution to improve laboratory bounds on CP-violating monopole-dipole forces with 1.5 μeV<m(b)c(2)<400 μeV by up to a factor of 1000.
Transport of Bose-Einstein condensates with optical tweezers.

We have transported gaseous Bose-Einstein condensates over distances up to 44 cm. This was accomplished by trapping the condensate in the focus of an infrared laser and translating the location of the laser focus with controlled acceleration. Condensates of order ${10}^{6}$ atoms were moved into an auxiliary chamber and loaded into a magnetic trap formed by a Z-shaped wire. This transport technique avoids the optical and mechanical access constraints of conventional condensate experiments and creates many new scientific opportunities.
WikiPassageQA: A Benchmark Collection for Research on Non-factoid Answer Passage Retrieval

With the rise in mobile and voice search, answer passage retrieval acts as a critical component of an effective information retrieval system for open domain question answering. Currently, there are no comparable collections that address non-factoid question answering within larger documents while simultaneously providing enough examples sufficient to train a deep neural network. In this paper, we introduce a new Wikipedia based collection specific for non-factoid answer passage retrieval containing thousands of questions with annotated answers and show benchmark results on a variety of state of the art neural architectures and retrieval models. The experimental results demonstrate the unique challenges presented by answer passage retrieval within topically relevant documents for future research.
Dynamic Control and Optimization of Distributed Energy Resources in a Microgrid

As we transition toward a power grid that is increasingly based on renewable resources like solar and wind, the intelligent control of distributed energy resources (DERs) including photovoltaic (PV) arrays, controllable loads, energy storage, and plug-in electric vehicles (EVs) will be critical to realizing a power grid that can handle both the variability and unpredictability of renewable energy sources as well as increasing system complexity. Realizing such a decentralized and dynamic infrastructure will require the ability to solve large scale problems in real-time with hundreds of thousands of DERs simultaneously online. Because of the scale of the optimization problem, we use an iterative distributed algorithm previously developed in our group to operate each DER independently and autonomously within this environment. The algorithm is deployed within a framework that allows the microgrid to dynamically adapt to changes in the operating environment. Specifically, we consider a commercial site equipped with on-site PV generation, partially curtailable load, EV charge stations and a battery electric storage unit. The site operates as a small microgrid that can participate in the wholesale market on the power grid. We report results for simulations using real-data that demonstrate the ability of the optimization framework to respond dynamically in real-time to external conditions while maintaining the functional requirements of all DERs.
Application of discrete adjoint method to sensitivity and uncertainty analysis in steady-state two-phase flow simulations

Abstract Adjoint method is efficient for computing sensitivities of a response to a large number of input parameters; however, a successful application of adjoint method to sensitivity analysis in two-phase flow simulations is rare. In this article, a discrete adjoint sensitivity analysis framework is developed for steady-state two-phase flow problems. The new framework is based on a new implicit forward solver. The residual function of the discretized forward governing equation is used to formulate the adjoint problem. The framework is verified with the faucet flow problem and the Boiling Water Reactor Full-size Fine-mesh Bundle Test (BFBT) benchmark. For the faucet flow problem, adjoint sensitivities are shown to match analytical sensitivities very well. For the BFBT benchmark, the adjoint sensitivities are shown to match the sensitivities calculated with a perturbation equation. The adjoint sensitivities are also used to propagate uncertainties in input parameters to the uncertainty in the response. The uncertainty propagation with the adjoint method is verified with the Monte Carlo method and is shown to be accurate and efficient.
Covariant non-local action for massless QED and the curvature expansion

We explore the properties of non-local effective actions which include gravitational couplings. Non-local functions originally defined in flat space can not be easily generalized to curved space. The problem is made worse by the calculational impossibility of providing closed form expressions in a general metric. The technique of covariant perturbation theory (CPT) has been pioneered by Vilkovisky, Barvinsky and collaborators whereby the effective action is displayed as an expansion in the generalized curvatures similar to the Schwinger-De Witt local expansion. We present an alternative procedure to construct the non-local action which we call non-linear completion. Our approach is in one-to-one correspondence with the more familiar diagrammatic expansion of the effective action. This technique moreover enables us to decide on the appropriate non-local action that generates the QED trace anomaly in 4D. In particular we discuss carefully the curved space generalization of ln □, and show that the anomaly requires both the anomalous logarithm as well as 1/□ term where the latter is related to the Riegert anomaly action.
On existence of extremizers for the Tomas-Stein inequality for $S^1$

Abstract The Tomas–Stein inequality or the adjoint Fourier restriction inequality for the sphere S 1 states that the mapping f ↦ f σ ˆ is bounded from L 2 ( S 1 ) to L 6 ( R 2 ) . We prove that there exists an extremizer for this inequality. We also prove that any extremizer satisfies | f ( − x ) | = | f ( x ) | for almost every x ∈ S 1 .
Tree codes improve convergence rate of consensus over erasure channels

We study the problem of achieving average consensus between a group of agents over a network with erasure links. In the context of consensus problems, the unreliability of communication links between nodes has been traditionally modeled by allowing the underlying graph to vary with time. In other words, depending on the realization of the link erasures, the underlying graph at each time instant is assumed to be a subgraph of the original graph. Implicit in this model is the assumption that the erasures are symmetric: if at time t the packet from node i to node j is dropped, the same is true for the packet transmitted from node j to node i. However, in practical wireless communication systems this assumption is unreasonable and, due to the lack of symmetry, standard averaging protocols cannot guarantee that the network will reach consensus to the true average. In this paper we explore the use of channel coding to improve the performance of consensus algorithms. For symmetric erasures, we show that, for certain ranges of the system parameters, repetition codes can speed up the convergence rate. For asymmetric erasures we show that tree codes (which have recently been designed for erasure channels) can be used to simulate the performance of the original “unerased” graph. Thus, unlike conventional consensus methods, we can guarantee convergence to the average in the asymmetric case. The price is a slowdown in the convergence rate, relative to the unerased network, which is still often faster than the convergence rate of conventional consensus algorithms over noisy links.
A new spin on neutrino quantum kinetics

Abstract Recent studies have demonstrated that in anisotropic environments a coherent spin-flip term arises in the Quantum Kinetic Equations (QKEs) which govern the evolution of neutrino flavor and spin in hot and dense media. This term can mediate neutrino–antineutrino transformation for Majorana neutrinos and active-sterile transformation for Dirac neutrinos. We discuss the physical origin of the coherent spin-flip term and provide explicit expressions for the QKEs in a two-flavor model with spherical geometry. In this context, we demonstrate that coherent neutrino spin transformation depends on the absolute neutrino mass and Majorana phases.
Nonlinear Pulsations of Convective Stellar Models

We review the numerical modeling of the nonlinear pulsations of classical variable stars with hydro-codes that include the effects of turbulent convection. Despite their simplicity these turbulent convective recipes appear to remove many of the difficulties that radiative codes faced. In particular, the numerical modeling of double mode pulsations has become possible.
A loop of SU(2) gauge fields stable under the Yang-Mills flow

The gradient flow of the Yang-Mills action acts pointwise on closed loops of gauge fields. We construct a topologically nontrivial loop of SU(2) gauge fields on S that is locally stable under the flow. The stable loop is written explicitly as a path between two gauge fields equivalent under a topologically nontrivial SU(2) gauge transformation. Local stability is demonstrated by calculating the flow equations to leading order in perturbations of the loop. The stable loop might play a role in physics as a classical winding mode of the lambda model, a 2-d quantum field theory that was proposed as a mechanism for generating spacetime quantum field theory. We also present evidence for 2-manifolds of SU(3) and SU(2) gauge fields that are stable under the Yang-Mills flow. These might provide 2-d instanton corrections in the lambda model. For Isidore M. Singer in celebration of his eighty-fifth birthday.
Training Deep Networks without Learning Rates Through Coin Betting

Deep learning methods achieve state-of-the-art performance in many application scenarios. Yet, these methods require a significant amount of hyperparameters tuning in order to achieve the best results. In particular, tuning the learning rates in the stochastic optimization process is still one of the main bottlenecks. In this paper, we propose a new stochastic gradient descent procedure for deep networks that does not require any learning rate setting. Contrary to previous methods, we do not adapt the learning rates nor we make use of the assumed curvature of the objective function. Instead, we reduce the optimization process to a game of betting on a coin and propose a learning rate free optimal algorithm for this scenario. Theoretical convergence is proven for convex and quasi-convex functions and empirical evidence shows the advantage of our algorithm over popular stochastic gradient algorithms.
Fourier coefficients of automorphic forms, character variety orbits, and small representations

Abstract Text We consider the Fourier expansions of automorphic forms on general Lie groups, with a particular emphasis on exceptional groups. After describing some principles underlying known results on GL ( n ) , Sp ( 4 ) , and G 2 , we perform an analysis of the expansions on split real forms of E 6 and E 7 where simplifications take place for automorphic realizations of real representations which have small Gelfand–Kirillov dimension. Though the character varieties are more complicated for exceptional groups, we explain how the nonvanishing Fourier coefficients for small representations behave analogously to Fourier coefficients on GL ( n ) . We use this mechanism, for example, to show that the minimal representation of either E 6 or E 7 never occurs in the cuspidal automorphic spectrum. We also give a complete description of the internal Chevalley modules of all complex Chevalley groups – that is, the orbit decomposition of the Levi factor of a maximal parabolic on its unipotent radical. This generalizes classical results on trivectors and in particular includes a full description of the complex character variety orbits for all maximal parabolics. The results of this paper have been applied in the string theory literature to the study of BPS instanton contributions to graviton scattering (Green et al., 2011, [12] ). Video For a video summary of this paper, please click here or visit http://www.youtube.com/watch?v=ELkyOT8c28I .
An optimal transport formulation of the linear feedback particle filter

Feedback particle filter (FPF) is an algorithm to numerically approximate the solution of the nonlinear filtering problem in continuous time. The algorithm implements a feedback control law for a system of particles such that the empirical distribution of particles approximates the posterior distribution. However, it has been noted in the literature that the feedback control law is not unique. To find a unique control law, the filtering task is formulated here as an optimal transportation problem between the prior and the posterior distributions. Based on this formulation, a time stepping optimization procedure is proposed for the optimal control design. A key difference between the optimal control law and the one in the original FPF, is the replacement of noise term with a deterministic term. This difference serves to decrease the simulation variance, as illustrated with a simple numerical example.
Message passing algorithms for compressed sensing: II. analysis and validation

In a recent paper, the authors proposed a new class of low-complexity iterative thresholding algorithms for reconstructing sparse signals from a small set of linear measurements [1]. The new algorithms are broadly referred to as AMP, for approximate message passing. This is the second of two conference papers describing the derivation of these algorithms, connection with related literature, extensions of original framework, and new empirical evidence. This paper describes the state evolution formalism for analyzing these algorithms, and some of the conclusions that can be drawn from this formalism. We carried out extensive numerical simulations to confirm these predictions. We present here a few representative results.
Doubling metric spaces are characterized by a lemma of Benjamini and Schramm

A useful property of Euclidean space originally shown by I. Benjamini and O. Schramm turns out to characterize doubling metric spaces.
The Smith and Critical Groups of the Square Rook's Graph and its Complement

Let $R_{n}$ denote the graph with vertex set consisting of the squares of an $n \times n$ grid, with two squares of the grid adjacent when they lie in the same row or column. This is the square rook's graph, and can also be thought of as the Cartesian product of two complete graphs of order $n$, or the line graph of the complete bipartite graph $K_{n,n}$. In this paper we compute the Smith group and critical group of the graph $R_{n}$ and its complement. This is equivalent to determining the Smith normal form of both the adjacency and Laplacian matrix of each of these graphs. In doing so we verify a 1986 conjecture of Rushanan.
ON KNOT FLOER HOMOLOGY FOR SOME FIBERED KNOTS

We use knot Floer surgery exact sequences and torsion invariants to compute the knot Floer homology of certain fibered knots in the double cover of S3 branched along the closure of an alternating braid.
The Radon transform on the Heisenberg group and the transversal Radon transform

Abstract The Radon transform on the Heisenberg group was introduced by R. Strichartz. We regard it as a particular case of a more general transversal Radon transform that integrates functions on R m over hyperplanes meeting the last coordinate axis. The paper contains new boundedness results and explicit inversion formulas for both transforms of L p functions in the full range of the parameter p. We also show that these transforms are isomorphisms of the corresponding Semyanistyi–Lizorkin spaces of smooth functions. In the framework of these spaces we obtain inversion formulas, which are pointwise analogues of the corresponding formulas by R. Strichartz.
Asymptotic ⁎-moments of some random Vandermonde matrices

Abstract Appropriately normalized square random Vandermonde matrices based on independent random variables with uniform distribution on the unit circle are studied. It is shown that as the matrix sizes increases without bound, with respect to the expectation of the trace there is an asymptotic ⁎-distribution, equal to that of a C [ 0 , 1 ] -valued R-diagonal element.
End-to-End Fine-Grained Action Segmentation and Recognition Using Conditional Random Field Models and Discriminative Sparse Coding

Fine-grained action segmentation and recognition is an important yet challenging task. Given a long, untrimmed sequence of kinematic data, the task is to classify the action at each time frame and segment the time series into the correct sequence of actions. In this paper, we propose a novel framework that combines a temporal Conditional Random Field (CRF) model with a powerful frame-level representation based on discriminative sparse coding. We introduce an end-to-end algorithm for jointly learning the weights of the CRF model, which include action classification and action transition costs, as well as an overcomplete dictionary of mid-level action primitives. This results in a CRF model that is driven by sparse coding features obtained using a discriminative dictionary that is shared among different actions and adapted to the task of structured output learning. We evaluate our method on three surgical tasks using kinematic data from the JIGSAWS dataset, as well as on a food preparation task using accelerometer data from the 50 Salads dataset. Our results show that the proposed method performs on par or better than state-of-the-art methods.
Learning continuous-time social network dynamics

We demonstrate that a number of sociology models for social network dynamics can be viewed as continuous time Bayesian networks (CTBNs). A sampling-based approximate inference method for CTBNs can be used as the basis of an expectation-maximization procedure that achieves better accuracy in estimating the parameters of the model than the standard method of moments algorithm from the sociology literature. We extend the existing social network models to allow for indirect and asynchronous observations of the links. A Markov chain Monte Carlo sampling algorithm for this new model permits estimation and inference. We provide results on both a synthetic network (for verification) and real social network data.
A microlocal category associated to a symplectic manifold

For a symplectic manifold subject to certain topological conditions a category enriched in \(A_{\infty }\) local systems of modules over the Novikov ring is constructed. The construction is based on the category of modules over Fedosov’s deformation quantization algebra that have an additional structure, namely an action of the fundamental groupoid up to inner automorphisms. Based in large part on the ideas of Bressler-Soibelman, Feigin, and Karabegov, it motivated by the theory of Lagrangian distributions and is related to other microlocal constructions of a category starting from a symplectic manifold, such as those due to Nadler-Zaslow and Tamarkin. In the case when our manifold is a flat two-torus, the answer is very close to both the Tamarkin microlocal category and the Fukaya category as computed by Polishchuk and Zaslow.
Fast luminous blue transients from newborn black holes

Newborn black holes in collapsing massive stars can be accompanied by a fallback disk. The accretion rate is typically super-Eddington and strong disk outflows are expected. Such outflows could be directly observed in some failed explosions of compact (blue supergiants or Wolf-Rayet stars) progenitors, and may be more common than longduration gamma-ray bursts. Using an analytical model, we show that the fallback disk outflows produce blue UV-optical transients with a peak bolometric luminosity of � 10 42 43 erg s 1 (peak R-band absolute AB magnitudes of 16 to 18) and �
List-Decodable Zero-Rate Codes

We consider list decoding in the zero-rate regime for two cases—the binary alphabet and the spherical codes in Euclidean space. Specifically, we study the maximal $\tau \in [{0,1}]$ for which there exists an arrangement of $M$ balls of relative Hamming radius $\tau $ in the binary hypercube (of arbitrary dimension) with the property that no point of the latter is covered by $L$ or more of them. As $M\to \infty $ the maximal $\tau $ decreases to a well-known critical value $\tau _{L}$ . In this paper, we prove several results on the rate of this convergence. For the binary case, we show that the rate is $\Theta (M^{-1})$ when $L$ is even, thus extending the classical results of Plotkin and Levenshtein for $L=2$ . For $L=3$ , the rate is shown to be $\Theta (M^{-({2}/{3})})$ . For the similar question about spherical codes, we prove the rate is $\Omega (M^{-1})$ and $O(M^{-({2L}/{L^{2}-L+2})})$ .
The emergence of the electrostatic field as a Feynman sum in random tilings with holes

We consider random lozenge tilings on the triangular lattice with holes Q 1 , ... , Q n in some fixed position. For each unit triangle not in a hole, consider the average orientation of the lozenge covering it. We show that the scaling limit of this discrete field is the electrostatic field obtained when regarding each hole Q i as an electrical charge of magnitude equal to the difference between the number of unit triangles of the two different orientations inside Q i . This is then restated in terms of random surfaces, yielding the result that the average over surfaces with prescribed height at the union of the boundaries of the holes is, in the scaling limit, a sum of helicoids.
On the order sequence of an embedding of the Ree curve

In this paper we compute the Weierstrass order-sequence associated with a certain linear series on the Deligne-Lusztig curve of Ree type. As a result, we determine that the set of Weierstrass points of this linear series consists entirely of $\mathbb F_q$-rational points.
Finding Friend and Foe in Multi-Agent Games

Recent breakthroughs in AI for multi-agent games like Go, Poker, and Dota, have seen great strides in recent years. Yet none of these games address the real-life challenge of cooperation in the presence of unknown and uncertain teammates. This challenge is a key game mechanism in hidden role games. Here we develop the DeepRole algorithm, a multi-agent reinforcement learning agent that we test on "The Resistance: Avalon", the most popular hidden role game. DeepRole combines counterfactual regret minimization (CFR) with deep value networks trained through self-play. Our algorithm integrates deductive reasoning into vector-form CFR to reason about joint beliefs and deduce partially observable actions. We augment deep value networks with constraints that yield interpretable representations of win probabilities. These innovations enable DeepRole to scale to the full Avalon game. Empirical game-theoretic methods show that DeepRole outperforms other hand-crafted and learned agents in five-player Avalon. DeepRole played with and against human players on the web in hybrid human-agent teams. We find that DeepRole outperforms human players as both a cooperator and a competitor.
Metal accumulation capacity in indigenous Alaska vegetation growing on military training lands

AbstractPermafrost thawing could increase soil contaminant mobilization in the environment. Our objective was to quantify metal accumulation capacities for plant species and functional groups commo...
The promise and peril of epistocracy

ABSTRACTJason Brennan’s Against Democracy makes a strong case that democratic majorities’ right to rule rests on shaky grounds so long as their ballot box decisions are heavily influenced by ignora...
Multiple Sound Source Localization with SVD-PHAT.

This paper introduces a modification of phase transform on singular value decomposition (SVD-PHAT) to localize multiple sound sources. This work aims to improve localization accuracy and keeps the algorithm complexity low for real-time applications. This method relies on multiple scans of the search space, with projection of each low-dimensional observation onto orthogonal subspaces. We show that this method localizes multiple sound sources more accurately than discrete SRP-PHAT, with a reduction in the Root Mean Square Error up to 0.0395 radians.
Combinatorial applications of the Hodge–Riemann relations

Why do natural and interesting sequences often turn out to be log-concave? We give one of many possible explanations, from the viewpoint of "standard conjectures". We illustrate with several examples from combinatorics.
Comparison of lift use, perceptions, and musculoskeletal symptoms between ceiling lifts and floor-based lifts in patient handling

Abstract Lifting equipment can reduce the risk of injury from patient handling, but limited availability and adoption have been a persistent problem. Data from statewide surveys of California nurses (N = 389) in 2013 and 2016 were analyzed to evaluate lift use, perceptions about lifts and injury risk, and musculoskeletal symptoms by type of available lifts. Nurses with ceiling lifts (23%) were significantly more likely to use lifts and had more positive perceptions about lifts, regarding worker safety, patient safety and comfort, ease of use, access, and storing, than nurses with only floor lifts (77%). Nurses with ceiling lifts reported less low back pain and shoulder pain. Our study findings suggest that providing ceiling lifts can result in superior outcomes to floor-based lifts in multiple aspects, including better acceptance and use by nurses for patient handling, as well as being associated with reduced work-related musculoskeletal symptoms in the low back and shoulders.
Configuration Sets with Nonempty Interior

A theorem of Steinhaus states that if $$E\subset \mathbb {R}^d$$ has positive Lebesgue measure, then the difference set $$E-E$$ contains a neighborhood of 0. Similarly, if E merely has Hausdorff dimension $$\hbox {dim}_{{\mathcal {H}}}(E)>(d+1)/2,$$ a result of Mattila and Sjolin states that the distance set $$\varDelta (E)\subset \mathbb {R}$$ contains an open interval. In this work, we study such results from a general viewpoint, replacing $$E-E$$ or $$\varDelta (E)$$ with more general $$\varPhi $$ -configurations for a class of $$\varPhi :\mathbb {R}^d\times \mathbb {R}^d\rightarrow \mathbb {R}^k,$$ and showing that, under suitable lower bounds on $$\hbox {dim}_{{\mathcal {H}}}(E)$$ and a regularity assumption on the family of generalized Radon transforms associated with $$\varPhi ,$$ it follows that the set $$\varDelta _\varPhi (E)$$ of $$\varPhi $$ -configurations in E has nonempty interior in $$\mathbb {R}^k$$ . Further extensions hold for $$\varPhi $$ -configurations generated by two sets, E and F, in spaces of possibly different dimensions and with suitable lower bounds on $$\hbox {dim}_{{\mathcal {H}}}(E)+\hbox {dim}_{{\mathcal {H}}}(F).$$
DEMO: EApp: Improving Rural Emergency Preparedness and Response

Large-scale emergencies, both natural and man-made, are increasingly incurring devastating losses in terms of infrastructure and human lives. Rural areas are particularly vulnerable to such losses. Emergency preparedness and response services, in rural areas, severely lag behind that of their urban counterparts. One of the key limiting factors is the lack of adequate broadband connectivity, which limits agencies' capabilities to (i) disseminate emergency preparedness and response information to residents and (ii) efficiently coordinate in the face of a disaster. In this demo, we present the EApp; a smartphone application that strives to improve the information access regarding emergencies for rural residents and first responders.
Robust data-driven approach for predicting the configurational energy of high entropy alloys

Abstract High entropy alloys (HEAs) are promising next-generation materials due to their various excellent properties. To understand these properties, it's necessary to characterize the chemical ordering and identify order-disorder transitions through efficient simulation and modeling of thermodynamics. In this study, a robust data-driven framework based on Bayesian approaches is proposed for the accurate and efficient prediction of configurational energy of high entropy alloys. The recently proposed effective pair interaction (EPI) model with ensemble sampling is used to map the configuration and its corresponding energy. Given limited data calculated by first-principles calculations, Bayesian regularized regression not only offers an accurate and stable prediction but also effectively quantifies the uncertainties associated with EPI parameters. Compared with the arbitrary truncation of model complexity, we further conduct a physical feature selection to identify the truncation of coordination shells in EPI model using Bayesian information criterion. The results achieve efficient and robust performance in predicting the configurational energy, particularly given small data. The developed methodology is applied to study a series of refractory HEAs, i.e. NbMoTaW, NbMoTaWV and NbMoTaWTi where it is demonstrated how dataset size affects the confidence when data is sparse.
Near-AdS_2 perturbations and the connection with near-extreme Reissner-Nordstrom

The geometry very near the horizon of a near-extreme Reissner–Nordstrom black hole is described by the direct product of a near-$$AdS_2$$ spacetime with a two-sphere. While near-$$AdS_2$$ is locally diffeomorphic to $$AdS_2$$ the two connect differently with the asymptotically flat part of the geometry of (near-)extreme Reissner–Nordstrom. In previous work, we solved analytically the coupled gravitational and electromagnetic perturbation equations of $$AdS_2\times S^2$$ and the associated connection problem with extreme Reissner–Nordstrom. In this paper, we give the solution for perturbations of near-$$AdS_2\times S^2$$ and make the connection with near-extreme Reissner–Nordstrom. Our results here may also be thought of as computing the classical scattering matrix for gravitational and electromagnetic waves which probe the region very near the horizon of a highly charged spherically symmetric black hole.
The increasing importance of fellowships and career development awards in the careers of early-stage biomedical academic researchers.

Excessive competition for biomedical faculty positions has ratcheted up the need to accumulate some mix of high-quality publications and prestigious grants to move from a training position to university faculty. How universities value each of these attributes when considering faculty candidates is critical for understanding what is needed to succeed as academic faculty. In this study, I analyzed publicly available NIH grant information to determine the grants first-time R01 (FTR01) awardees held during their training period. Increases in the percentage of the FTR01 population that held a training award demonstrate these awards are becoming a more common component of a faculty candidate’s resume. The increase was largely due to an expansion of NIH K-series career development awards between 2000 and 2017. FTR01 awardees with a K01, K08, K23, or K99 award were overrepresented in a subset of institutions, whereas FTR01 awardees with F32 fellowships and those with no training award were evenly distributed across institutions. Finally, training awardees from the largest institutions were overrepresented in the faculty of the majority of institutions, echoing data from other fields where a select few institutions supply an overwhelming majority of the faculty for the rest of the field. These data give important insight into how trainees compete for NIH funding and faculty positions and how institutions prefer those with or without training awards.
International Education for Enlightenment, for Opportunity and for Survival: Where Students, Migrants and Refugees Diverge

This article argues that participants in international education fall into three broad but distinctly different categories: Mobility for Enlightenment, Mobility for Opportunity, and Mobility for Survival. By examining participants who study in a country other than their own through this lense, this article will be useful to educators who seek not only to better understand who is participating in international education globally, but also to account better for their situations and needs. This categorization of participant types has not yet been sufficiently analyzed in the extant literature in Comparative and International Education but must be given current geopolitical realities. Recognizing important differences between all those who are involved in global educational mobility is meant to encourage a more vigorous dialogue among scholar-practitioners who are woriing n the field of International Education, so they can bring in additional evidence and examples to help further build upon these three initial proposed categories.
An SR Flip-Flop based Physical Unclonable Functions for Hardware Security

Physical Unclonable Functions (PUFs) have emerged as a promising solution to identify and authenticate Integrated Circuits (ICs). In this paper, we propose a novel NAND-based Set-Reset (SR) Flip-flop (FF) PUF design for security enclosures of the area- and power-constrained Internet-of-Things (IoT) edge node. Such SR-FF based PUF is constructed during a unique race condition that is (normally) avoided due to inconsistency. We have shown, when both inputs (S and R) are logic high (‘1’) and followed by logic zero (‘0’), the outputs Q and $\bar Q$ can settle down to either 0 or 1 or vice-versa depending on statistical delay variations in cross-coupled paths. We incorporate the process variations during SPICE-level simulations to leverage the capability of SR-FF in generating the unique identifier of an IC. Experimental results for 90nm, 45nm, and 32nm process nodes show the robustness of SR-FF PUF responses in terms of uniqueness, randomness, uniformity, and bit(s) biases. Furthermore, we perform physical synthesis to evaluate the applicability of SR FF PUF on five designs from OpenCores in three design corners. The estimated overhead for power, timing, and area in three design corners are negligible.
Gains from anchoring inflation expectations: Evidence from the taper tantrum shock

Abstract Have improvements in monetary policy frameworks increased emerging market resilience to external shocks? This paper exploits the May 2013 taper tantrum episode in the United States to study the reaction of 18 large emerging markets to an external shock, conditioning on their degree of inflation expectations’ anchoring. We find that while the tapering announcement negatively affected growth prospects regardless of the level of anchoring, countries with weakly anchored inflation expectations experienced larger exchange rate pass-through to consumer prices and higher inflation. These findings suggest that gains in inflation expectations’ anchoring can improve central bank’s policy trade-offs when facing external shocks.
Household debt, consumption and inequality

Abstract This paper examines the link between household credit shocks, consumption and income inequality at the national level. Empirically, we use country-specific VAR models to estimate the dynamic responses of aggregate consumption to household credit shocks. We then show in cross-country regressions that the consumption response is more sensitive to such shocks in countries with higher levels of inequality, even after controlling for financial development. Theoretically, we construct and simulate a dynamic model based on the effect of inequality on the incidence of credit constraints, to illustrate potential causal mechanisms.
Topology-aware resource allocation for data-intensive workloads

This paper proposes an architecture for optimized resource allocation in Infrastructure-as-a-Service (IaaS)-based cloud systems. Current IaaS systems are usually unaware of the hosted application's requirements and therefore allocate resources independently of its needs, which can significantly impact performance for distributed data-intensive applications.To address this resource allocation problem, we propose an architecture that adopts a what if methodology to guide allocation decisions taken by the IaaS. The architecture uses a prediction engine with a lightweight simulator to estimate the performance of a given resource allocation and a genetic algorithm to find an optimized solution in the large search space. We have built a prototype for Topology-Aware Resource Allocation (TARA) and evaluated it on a 80 server cluster with two representative MapReduce-based benchmarks. Our results show that TARA reduces the job completion time of these applications by up to 59% when compared to application-independent allocation policies.
Interactive Multiresolution Visualization of Cellular Network Processes.

Summary Visualization plays a central role in the analysis of biochemical network models to identify patterns that arise from reaction dynamics and perform model exploratory analysis. To facilitate these analyses, we developed PyViPR, a visualization tool that generates static and dynamic representations of biochemical network processes within a Python-based environment. PyViPR embeds network visualizations within Jupyter notebooks, thus enabling integration with modeling, simulation, and analysis workflows. To present the capabilities of PyViPR, we explore execution mechanisms of extrinsic apoptosis in HeLa cells. We show that community-detection algorithms identify groups of molecular species that capture key biological functions and ease exploration of the apoptosis network. We then show how different kinetic parameter sets that fit the experimental data equally well exhibit significantly different signal-execution dynamics as the system progresses toward mitochondrial outer-membrane permeabilization. Therefore, PyViPR aids the conceptual understanding of dynamic network processes and accelerates hypothesis generation for further testing and validation.
Orbit determination singularities in the Doppler tracking of a planetary orbiter

On a number of occasions, spacecraft launched by the U.S. have been placed into orbit about the moon, Venus, or Mars. It is pointed out that, in particular, in planetary orbiter missions two-way coherent Doppler data have provided the principal data type for orbit determination applications. The present investigation is concerned with the problem of orbit determination on the basis of Doppler tracking data in the case of a spacecraft in orbit about a natural body other than the earth or the sun. Attention is given to Doppler shift associated with a planetary orbiter, orbit determination using a zeroth-order model for the Doppler shift, and orbit determination using a first-order model for the Doppler shift.
“Synthetic metals”: a novel role for organic polymers

Since the initial discovery in 1977, that polyacetylene (CH)x, now commonly known as the prototype conducting polymer, could be p- or n-doped either chemically or electronically to the metallic state, the development of the field conducting polymers, “synthetic metals”, has continued to accelerate at an unexpectedly rapid rate and a variety of other conducting polymers and their derivatives have been discovered. Potential new science/technology has been developed by combining the now well established field of electronic polymers (intrinsically conducting polymers – “synthetic metals”, when doped) with the emerging field of nanoscience (one dimension <100 nm). A simple and inexpensive method is described for producing conducting patterns of electronic polymers on plastic and paper from computer-designed patterns. This method, “Line Patterning”, does not involve printing of the conducting polymers. The difference in hydrophobicity/hydrophilicity between a substrate and a line of regular toner printed on it by a non-modified, standard ofiice laser printer results in conducting polymer areas separated by insulating toner lines.
The Retraction of Stretched Rubber

Abstract For some time we have been making measurements of the velocities acquired by rubber strips when retracting after being stretched. The rubber band is stretched in front of two photocells, cutting off two sharply focussed light beams. When the strip is released, the beams impinge successively on the photocells, the first of which starts the charging of a condenser, and the second of which stops the charging current. The resulting voltage on the condenser is thus a measure of the time required for the free end of the rubber strip to traverse the distance between the two light beams. Retraction velocities of the order of several hundred miles per hour have been observed. To explain some of our results and to secure a more detailed picture of the mechanism of retraction, we have also taken pictures of retracting rubber strips, with a high-speed stroboscopic lamp. These seemed to be of sufficient general interest to present here.
Har-P, a short P-element variant, weaponizes P-transposase to severely impair Drosophila development.

DNA provides the instructions needed for life, a role that relies on it being a very stable and organized molecule. However, some sections of DNA are able to move from one place in the genome to another. When these “mobile genetic elements” move they may disrupt other genes and cause disease. For example, a mobile section of DNA known as the P-element causes a condition called gonadal dysgenesis in female fruit flies, leading to infertility. Only certain strains of fruit flies carry P-elements and the severity of gonadal dysgenesis in their daughters varies. For example, when male fruit flies of a strain known as Harwich (or Har for short) is crossed with female fruit flies that do not contain P-elements, all of their daughters develop severe gonadal dysgenesis and are infertile. However, if the cross is done the other way around, and female Har flies mate with males that do not contain P-elements, the daughters are fertile because the Har mothers provide their daughters with protective molecules that silence the P-elements. But it was a mystery as to why the P-elements from the Har fathers always caused such severe gonadal dysgenesis in all the daughters. Here, Srivastav et al. bred fruit flies to create offspring that had different pieces of Har DNA in a genetic background that was normally free from P-elements; they then analyzed the ‘hybrid’ offspring to identify which pieces of the Har genome caused gonadal dysgenesis in the daughter flies. These experiments showed that Har flies possess a very short variant of the P-element (named “Har-P”) that is more mobile than other variants. However, the Har-P variants still depended on an enzyme known as P-transposase encoded by the full-length P-elements to move around the genome. Further experiments showed that other strains of fruit flies that cause severe gonadal dysgenesis also had very short P-element variants that were almost identical to Har-P. These findings may explain why Har and some other strains of fruit flies drive severe gonadal dysgenesis. In the future, it may be possible to transfer P-transposase and Har-P into mosquitoes, ticks and other biting insects to make them infertile and help reduce the spread of certain diseases in humans.