cssi/SciSciGPT-SciSciNet huggingface dataset:
Asymptotic equivalence of regularization methods in thresholded parameter space

High-dimensional data analysis has motivated a spectrum of regularization methods for variable selection and sparse modeling, with two popular methods being convex and concave ones. A long debate has taken place on whether one class dominates the other, an important question both in theory and to practitioners. In this article, we characterize the asymptotic equivalence of regularization methods, with general penalty functions, in a thresholded parameter space under the generalized linear model setting, where the dimensionality can grow exponentially with the sample size. To assess their performance, we establish the oracle inequalities—as in Bickel, Ritov, and Tsybakov (2009)—of the global minimizer for these methods under various prediction and variable selection losses. These results reveal an interesting phase transition phenomenon. For polynomially growing dimensionality, the L 1-regularization method of Lasso and concave methods are asymptotically equivalent, having the same convergence rates in the...
Predictions on the core mass of Jupiter and of giant planets in general

More than 80 giant planets are known by mass and radius. Their interior structure in terms of core mass, number of layers, and composition however is still poorly known. An overview is presented about the core mass Mcore and envelope mass of metals MZ in Jupiter as predicted by various equations of state. It is argued that the uncertainty about the true H/He EOS in a pressure regime where the gravitational moments J2 and J4 are most sensitive, i.e. between 0.5 and 4 Mbar, is in part responsible for the broad range \(M_{\mathit{core}}=0{-}18\:M_{\oplus }\), \(M_{Z}=0{-}38\:M_{\oplus }\), and \(M_{\mathit{core}}+M_{Z}=14{-}38\:M_{\oplus }\) currently offered for Jupiter. We then compare the Jupiter models obtained when we only match J2 with the range of solutions for the exoplanet \(\mathrm{GJ}\:436\mathrm{b}\), when we match an assumed tidal Love number k2 value.
Separation of the largest eigenvalues in eigenanalysis of genotype data from discrete subpopulations

We present a mathematical model, and the corresponding mathematical analysis, that justifies and quantifies the use of principal component analysis of biallelic genetic marker data for a set of individuals to detect the number of subpopulations represented in the data. We indicate that the power of the technique relies more on the number of individuals genotyped than on the number of markers.
Variable Galaxies in the Hubble Deep Field

We present results from a study to detect variable galaxies in the Hubble Deep Field North (HDF-N). The goal of this project is to investigate the number density of active galactic nuclei (AGNs) at z 1 through the detection of variable galaxy nuclei. The advantage of the Hubble Space Telescope is its ability to do accurate photometry within smaller apertures, thus allowing us to probe much lower AGN/host galaxy luminosity ratios than can be done from the ground. The primary data sets analyzed for galactic variability follow from the original HDF-N observations in 1995 December and a second epoch obtained 2 years later. The second-epoch data consist of 36 exposures in F814W with a total integration time of 63,000 s (compared with 58 exposures and a total of 123,600 s in the original HDF-N). We have detected nuclear variability at or above the 3 σ level in eight of 633 HDF galaxies at I814 27. Only two detections would be expected by chance in a normal distribution. At least one of these eight has been spectroscopically confirmed as a Seyfert 1 galaxy. Based on the AGN structure function for variability, the estimated luminosity of the varying component in each galaxy lies in the range -19.5MB -15.0. We construct an upper limit to the luminosity function for the variable nuclei and compare this with the local Seyfert luminosity function (LF) and the LFs for quasi-stellar objects at z 1. Assuming we have detected all Seyfert-like nuclei in the HDF-N, we find no evidence for an increase in the number density of AGNs at MB -19 (H0 = 75 km s-1 Mpc-1, q0 = 0.5). From this study, we estimate that ~1%–3% of field galaxies with I 27 may contain a nuclear AGN.
Degenerations and representations of twisted Shibukawa-Ueno R-operators

We study degenerations of the Belavin R-matrices via the infinite dimensional operators defined by Shibukawa–Ueno. We define a two-parameter family of generalizations of the Shibukawa–Ueno R-operators. These operators have finite dimensional representations which include Belavin's R-matrices in the elliptic case, a two-parameter family of twisted affinized Cremmer–Gervais R-matrices in the trigonometric case, and a two-parameter family of twisted (affinized) generalized Jordanian R-matrices in the rational case. We find finite dimensional representations which are compatible with the elliptic to trigonometric and rational degeneration. We further show that certain members of the elliptic family of operators have no finite dimensional representations. These R-operators unify and generalize earlier constructions of Felder and Pasquier, Ding and Hodges, and the authors, and illuminate the extent to which the Cremmer–Gervais R-matrices (and their rational forms) are degenerations of Belavin's R-matrix.
Brendle’s Inequality on Static Manifolds

We generalize Brendle’s geometric inequality considered in Brendle (Publ Math Inst Hautes Etudes Sci 117:247–269, 2013) to static manifolds. The inequality bounds the integral of inverse mean curvature of an embedded mean-convex hypersurface by geometric data of the horizon. As a consequence, we obtain a reverse Penrose inequality on static asymptotically locally hyperbolic manifolds in the spirit of Chruściel and Simon (J Math Phys 42(4):1779–1817, 2001).
Separations in query complexity using cheat sheets

We show a power 2.5 separation between bounded-error randomized and quantum query complexity for a total Boolean function, refuting the widely believed conjecture that the best such separation could only be quadratic (from Grover's algorithm). We also present a total function with a power 4 separation between quantum query complexity and approximate polynomial degree, showing severe limitations on the power of the polynomial method. Finally, we exhibit a total function with a quadratic gap between quantum query complexity and certificate complexity, which is optimal (up to log factors). These separations are shown using a new, general technique that we call the cheat sheet technique, which builds upon the techniques of Ambainis et al. [STOC 2016]. The technique is based on a generic transformation that converts any (possibly partial) function into a new total function with desirable properties for showing separations. The framework also allows many known separations, including some recent breakthrough results of Ambainis et al. [STOC 2016], to be shown in a unified manner.
Connectedness of two-sided group digraphs and graphs

Two-sided group digraphs and graphs, introduced by Iradmusa and Praeger, provide a generalization of Cayley digraphs and graphs in which arcs are determined by left and right multiplying by elements of two subsets of the group. We characterize when two-sided group digraphs and graphs are weakly and strongly connected and count connected components, using both an explicit elementary perspective and group actions. Our results and examples address four open problems posed by Iradmusa and Praeger that concern connectedness and valency. We pose five new open problems.
Losses in plasmonics: from mitigating energy dissipation to embracing loss-enabled functionalities

Unlike conventional optics, plasmonics enables unrivaled concentration of optical energy well beyond the diffraction limit of light. However, a significant part of this energy is dissipated as heat. Plasmonic losses present a major hurdle in the development of plasmonic devices and circuits that can compete with other mature technologies. Until recently, they have largely kept the use of plasmonics to a few niche areas where loss is not a key factor, such as surface-enhanced Raman scattering and biochemical sensing. Here, we discuss the origin of plasmonic losses and various approaches to either minimize or mitigate them based on understanding of fundamental processes underlying surface plasmon modes excitation and decay. Along with the ongoing effort to find and synthesize better plasmonic materials, optical designs that modify the optical powerflow through plasmonic nanostructures can help in reducing both radiative damping and dissipative losses of surface plasmons. Another strategy relies on the development of hybrid photonic–plasmonic devices by coupling plasmonic nanostructures to resonant optical elements. Hybrid integration not only helps to reduce dissipative losses and radiative damping of surface plasmons, but also makes possible passive radiative cooling of nanodevices. Finally, we review emerging applications of thermoplasmonics that leverage Ohmic losses to achieve new enhanced functionalities. The most successful commercialized example of a loss-enabled novel application of plasmonics is heat-assisted magnetic recording. Other promising technological directions include thermal emission manipulation, cancer therapy, nanofabrication, nanomanipulation, plasmon-enabled material spectroscopy and thermo-catalysis, solar water treatment, and thermophotovoltaics.
Thickness Engineered Tunnel Field-Effect Transistors Based on Phosphorene

Thickness engineered tunneling field-effect transistors (TE-TFET) as a high-performance ultra-scaled steep transistor is proposed. This device exploits a specific property of 2-D materials: layer thickness-dependent energy bandgaps ( $E_{g}$ ). Unlike the conventional hetero-junction TFETs, TE-TFET uses spatially varying layer thickness to form a hetero-junction. This offers advantages by avoiding the lattice mismatch problems at the interface. Furthermore, it boosts the ON-current to $1280~\mu A/\mu m$ with 15-nm channel length. Providing higher ON currents, phosphorene TE-TFET outperforms the homojunction phosphorene and the TMD TFETs in terms of extrinsic energy-delay product. TE-TFET also scales well to 9 nm with constant field scaling $E = V_{DD}/L_{ch}= 33$ mV/nm. In this letter, the operation principles of TE-TFET and its performance sensitivity to the design parameters are investigated through full-band atomistic quantum transport simulations.
An index theorem in differential $K$–theory

Let π:X→B be a proper submersion with a Riemannian structure. Given a differential K–theory class on X, we define its analytic and topological indices as differential K–theory classes on B. We prove that the two indices are the same.
Topological defect lines and renormalization group flows in two dimensions

We consider topological defect lines (TDLs) in two-dimensional conformal field theories. Generalizing and encompassing both global symmetries and Verlinde lines, TDLs together with their attached defect operators provide models of fusion categories without braiding. We study the crossing relations of TDLs, discuss their relation to the 't Hooft anomaly, and use them to constrain renormalization group flows to either conformal critical points or topological quantum field theories (TQFTs). We show that if certain non-invertible TDLs are preserved along a RG flow, then the vacuum cannot be a non-degenerate gapped state. For various massive flows, we determine the infrared TQFTs completely from the consideration of TDLs together with modular invariance.
The Ion-Induced Charge-Exchange X-Ray Emission of the Jovian Auroras: Magnetospheric or Solar Wind Origin?

A new and more comprehensive model of charge-exchange induced X-ray emission, due to ions precipitating into the Jovian atmosphere near the poles, has been used to analyze spectral observations made by the Chandra X-ray Observatory. The model includes for the first time carbon ions, in addition to the oxygen and sulfur ions previously considered, in order to account for possible ion origins from both the solar wind and the Jovian magnetosphere. By comparing the model spectra with newly reprocessed Chandra observations, we conclude that carbon ion emission provides a negligible contribution, suggesting that solar wind ions are not responsible for the observed polar X-rays. In addition, results of the model fits to observations support the previously estimated seeding kinetic energies of the precipitating ions (~0.7-2 MeV u–1), but infer a different relative sulfur-to-oxygen abundance ratio for these Chandra observations.
Rigidity Properties for Hyperbolic Generalizations

We make a few observations on the absence of geometric and topological rigidity for acylindrically hyperbolic and relatively hyperbolic groups. In particular, we demonstrate the lack of a well-defined limit set for acylindrical actions on hyperbolic spaces, even under the assumption of universality. We also prove a statement about relatively hyperbolic groups inspired by a remark by Groves, Manning, and Sisto about the quasi-isometry type of combinatorial cusps. Finally, we summarize these results in a table in order to assert a meta-statement about the decay of metric rigidity as the conditions on actions on hyperbolic spaces are loosened.
Transforming Common III–V and II–VI Semiconductor Compounds into Topological Heterostructures: The Case of CdTe/InSb Superlattices

Currently, known topological insulators (TIs) are limited to narrow gap compounds incorporating heavy elements, thus severely limiting the material pool available for such applications. It is shown via first-principle calculations that a heterovalent superlattice made of common semiconductor building blocks can transform its non-TI components into a topological nanostructure, illustrated by III–V/II–VI superlattice InSb/CdTe. The heterovalent nature of such interfaces sets up, in the absence of interfacial atomic exchange, a natural internal electric field that along with the quantum confinement leads to band inversion, transforming these semiconductors into a topological phase while also forming a giant Rashba spin splitting. The relationship between the interfacial stability and the topological transition is revealed, finding a “window of opportunity” where both conditions can be optimized. Once a critical InSb layer thickness above ≈1.5 nm is reached, both [111] and [100] superlattices have a relative energy of 1.7–9.5 meV A–2, higher than that of the atomically exchanged interface and an excitation gap up to ≈150 meV, affording room-temperature quantum spin Hall effect in semiconductor superlattices. The understanding gained from this study could broaden the current, rather restricted repertoire of functionalities available from individual compounds by creating next-generation superstructured functional materials.
Analytical Model for the Tidal Evolution of the Evection Resonance and the Timing of Resonance Escape

A high-angular momentum giant impact with the Earth can produce a Moon with a silicate isotopic composition nearly identical to that of Earth's mantle, consistent with observations of terrestrial and lunar rocks. However, such an event requires subsequent angular momentum removal for consistency with the current Earth-Moon system. The early Moon may have been captured into the evection resonance, occurring when the lunar perigee precession period equals 1 year. It has been proposed that after a high- angular momentum giant impact, evection removed the angular momentum excess from the Earth-Moon pair and transferred it to Earth's orbit about the Sun. However, prior N-body integrations suggest this result depends on the tidal model and chosen tidal parameters. Here, we examine the Moon's encounter with evection using a complementary analytic description and the Mignard tidal model. While the Moon is in resonance, the lunar longitude of perigee librates, and if tidal evolution excites the libration amplitude sufficiently, escape from resonance occurs. The angular momentum drain produced by formal evection depends on how long the resonance is maintained. We estimate that resonant escape occurs early, leading to only a small reduction (~ few to 10%) in the Earth-Moon system angular momentum. Moon formation from a high-angular momentum impact would then require other angular momentum removal mechanisms beyond standard libration in evection, as have been suggested previously.
The geopolitics of international trade in Southeast Asia

Motivated by the historically tense geopolitical situation in Southeast Asia, the paper simulates the potential closure of key maritime waterways in the region to predict the impact on trade and welfare. The authors generate initial (unobstructed) and counterfactual (rerouted) least-cost maritime paths between trading countries, and use the distances of these routes in a workhorse model of international trade to estimate welfare effects. They find heterogeneous and economically significant reductions in real GDP, and show the magnitude of welfare loss is directly correlated with military spending as a proportion of GDP, suggesting nations may be responding to economic security threats posed by such potential conflicts.
Beam squint and Stokes V with off-axis feeds

Radio telescopes with off-axis feeds, such as the (E)VLA, suffer from “beam squint” in which the two orthogonal circular polarizations sampled have different pointing centers on the sky. Its effects are weak near the beam center but become increasingly important towards the edge of the antenna power pattern where gains in the two polarizations at a given sky position are significantly different. This effect has limited VLA measurements of circular polarization (Stokes V ) and introduced dynamic range limiting, wide-field artifacts in images made in Stokes I . We present an adaptation of the visibility-based deconvolution CLEAN method that can correct this defect “on the fly” while imaging, correcting as well the associated self-calibration. We present two examples of this technique using the procedure “Squint” within the Obit package which allows wide-field imaging in Stokes V and reduced artifacts in Stokes I . We discuss the residual errors in these examples as well as a scheme for future correction of some of these errors. This technique can be generalized to implement temporally- and spatially-variable corrections, such as pointing and cross-polarization leakage errors.
Arbitrage-Free Combinatorial Market Making via Integer Programming

We present a new combinatorial market maker that operates arbitrage-free combinatorial prediction markets specified by integer programs. Although the problem of arbitrage-free pricing, while maintaining a bound on the subsidy provided by the market maker, is #P-hard in the worst case, we posit that the typical case might be amenable to modern integer programming (IP) solvers. At the crux of our method is the Frank-Wolfe (conditional gradient) algorithm which is used to implement a Bregman projection aligned with the market maker's cost function, using an IP solver as an oracle. We demonstrate the tractability and improved accuracy of our approach on real-world prediction market data from combinatorial bets placed on the 2010 NCAA Men's Division I Basketball Tournament, where the outcome space is of size $2^{63}$. To our knowledge, this is the first implementation and empirical evaluation of an arbitrage-free combinatorial prediction market on this scale.
Observation of degenerate one-dimensional sub-bands in cylindrical InAs nanowires.

One-dimensional (1D) sub-bands in cylindrical InAs nanowires (NWs) are electrically mapped as a function of NW diameter in the range of 15–35 nm. At low temperatures, stepwise current increases with the gate voltage are clearly observed and attributed to the electron transport through individual 1D sub-bands. The 2-fold degeneracy in certain sub-band energies predicted by simulation due to structural symmetry is experimentally observed for the first time. The experimentally obtained sub-band energies match the simulated results, shedding light on both the energies of the sub-bands as well as the number of sub-bands populated per given gate voltage and diameter. This work serves to provide better insight into the electrical transport behavior of 1D semiconductors.
Functional methods for Heavy Quark Effective Theory

We use functional methods to compute one-loop effects in Heavy Quark Effective Theory. The covariant derivative expansion technique facilitates the efficient extraction of matching coefficients and renormalization group evolution equations. This paper pro- vides the first demonstration that such calculations can be performed through the algebraic evaluation of the path integral for the class of effective field theories that are (i) constructed using a non-trivial one-to-many mode decomposition of the UV theory, and (ii) valid for non-relativistic kinematics. We discuss the interplay between operators that appear at intermediate steps and the constraints imposed by the residual Lorentz symmetry that is encoded as reparameterization invariance within the effective description. The tools presented here provide a systematic approach for computing corrections to higher order in the heavy mass expansion; precision applications include predictions for experimental data and connections to theoretical tests via lattice QCD. A set of pedagogical appendices comprehensively reviews modern approaches to performing functional calculations algebraically, and derives contributions from a term with open covariant derivatives for the first time.
The Great Wall: Urca Cooling Layers in the Accreted NS Crust

Accreting neutron stars host a number of astronomical observables which can be used to infer the properties of the underlying dense matter. These observables are sensitive to the heating and cooling processes taking place in the accreted neutron star (NS) crust. Within the past few years it has become apparent that electron-capture/beta-decay (urca) cycles can operate within the NS crust at high temperatures. Layers of nuclei undergoing urca cycling can create a thermal barrier, or Great Wall, between heating occurring deep in the crust and the regions above the urca layers. This paper briefly reviews the urca process and the implications for observables from accreting neutron stars.
DLow: Diversifying Latent Flows for Diverse Human Motion Prediction

Deep generative models are often used for human motion prediction as they are able to model multi-modal data distributions and characterize diverse human behavior. While much care has been taken into designing and learning deep generative models, how to efficiently produce diverse samples from a deep generative model after it has been trained is still an under-explored problem. To obtain samples from a pretrained generative model, most existing generative human motion prediction methods draw a set of independent Gaussian latent codes and convert them to motion samples. Clearly, this random sampling strategy is not guaranteed to produce diverse samples for two reasons: (1) The independent sampling cannot force the samples to be diverse; (2) The sampling is based solely on likelihood which may only produce samples that correspond to the major modes of the data distribution. To address these problems, we propose a novel sampling method, Diversifying Latent Flows (DLow), to produce a diverse set of samples from a pretrained deep generative model. Unlike random (independent) sampling, the proposed DLow sampling method samples a single random variable and then maps it with a set of learnable mapping functions to a set of correlated latent codes. The correlated latent codes are then decoded into a set of correlated samples. During training, DLow uses a diversity-promoting prior over samples as an objective to optimize the latent mappings to improve sample diversity. The design of the prior is highly flexible and can be customized to generate diverse motions with common features (e.g., similar leg motion but diverse upper-body motion). Our experiments demonstrate that DLow outperforms state-of-the-art baseline methods in terms of sample diversity and accuracy. Our code is released on the project page: this https URL.
Solar Thermoradiative-Photovoltaic Energy Conversion

Summary A continuous supply of renewable energy requires intermittent sources to be paired with storage. Thermal storage is an excellent match for solar energy, but concentrating solar power plants must use high optical concentrations and large plants to be cost competitive. Here, we propose an alternative, solid-state heat engine for solar-thermal conversion consisting of a solar absorber, a thermoradiative cell, and a photovoltaic cell. Heat from the solar absorber or thermal storage drives radiative recombination current in the thermoradiative cell, and its emitted light is used by the photovoltaic cell. Based on the principle of detailed balance, we calculate a limiting solar conversion efficiency of 85% for fully concentrated sunlight and 45% for one sun with an absorber and single-junction cells of equal areas. Solar thermoradiative-photovoltaic systems outperform similar solar thermophotovoltaic converters for low band gaps and practical absorber temperatures, and for a realistic device, this improvement can be up to 7.9% (absolute).
Embedded Index Coding

Motivated by applications in distributed storage and distributed computation, we introduce embedded index coding (EIC). EIC is a type of distributed index coding in which nodes in a distributed system act as both broadcast senders and receivers of information. We show how linear embedded index coding is related to linear index coding in general, and give characterizations and bounds on the communication costs of optimal embedded index codes. We also define task-based EIC, in which there is only one sender node responsible for transmitting a block to a particular receiving node. Task-based EIC is more computationally tractable and has advantages in applications such as distributed storage, in which senders may complete their broadcasts at different times. Finally, we give heuristic algorithms for approximating optimal linear embedded index codes, and demonstrate empirically that these algorithms perform well.
Complement factor C4a does not activate protease-activated receptor 1 (PAR1) or PAR4 on human platelets.

Background Protease-activated receptor (PAR) 1 and PAR4 are key thrombin signal mediators for human platelet activation and aggregation in response to vascular injury. They are primarily activated by thrombin cleavage of the N-terminus to expose a tethered ligand. In addition to the canonical activation by thrombin, a growing panel of proteases can also elicit PAR1- or PAR4-mediated signal transduction. Recently, complement factor C4a was reported as the first endogenous agonist for both PAR1 and PAR4. Further, it is the first endogenous nontethered ligand that activates PAR1 and PAR4. These studies were conducted with human microvascular cells; the impact of C4a on platelet PARs is unknown. Objectives The goal of this study was to interrogate PAR1 and PAR4 activation by C4a on human platelets. Methods Platelet-rich plasma (PRP) was isolated from healthy donors. PRP was stimulated with C4a, and the platelet aggregation was measured. Human embryonic kidney (HEK) 293 Flp-In T-rex cells were used to further test if C4a stimulation can initiate PAR1- or PAR4-mediated Gαq signaling, which was measured by intracellular calcium mobilization. Results C4a failed to elicit platelet aggregation via PAR1- or PAR4-mediated manner. In addition, no PAR1- or PAR4-mediated calcium mobilization was observed upon C4a stimulation on HEK293 cells. Conclusions Complement factor C4a does not activate PAR1 or PAR4 on human platelets. These data show that PAR1 and PAR4 activation by C4a on microvascular cells likely requires a cofactor, which reinforces the concept of cell type-specific regulation of protease signaling.
U.S. Test System with High Spatial and Temporal Resolution for Renewable Integration Studies

Planning for power systems with high penetrations of variable renewable energy requires higher spatial and temporal granularity. However, most publicly available test systems are of insufficient fidelity for developing methods and tools for high-resolution planning. This paper presents methods to construct open-access test systems of high spatial resolution to more accurately represent infrastructure and high temporal resolution to represent dynamics of demand and variable resources. To demonstrate, a high-resolution test system representing the United States is created using only publicly available data. This test system is validated by running it in a production cost model, with results compared against historical generation to ensure that they are representative. The resulting open source test system can support power system transition planning and aid in development of tools to answer questions around how best to reach decarbonization goals, using the most effective combinations of transmission expansion, renewable generation, and energy storage.
A positivity phenomenon in Elser's Gaussian-cluster percolation model

Abstract Veit Elser proposed a random graph model for percolation in which physical dimension appears as a parameter. Studying this model combinatorially leads naturally to the consideration of numerical graph invariants which we call Elser numbers els k ( G ) , where G is a connected graph and k a nonnegative integer. Elser had proven that els 1 ( G ) = 0 for all G. By interpreting the Elser numbers as reduced Euler characteristics of appropriate simplicial complexes called nucleus complexes, we prove that for all graphs G, they are nonpositive when k = 0 and nonnegative for k ⩾ 2 . The last result confirms a conjecture of Elser. Furthermore, we give necessary and sufficient conditions, in terms of the 2-connected structure of G, for the nonvanishing of the Elser numbers.
Understanding Contrastive Representation Learning through Alignment and Uniformity on the Hypersphere

Contrastive representation learning has been outstandingly successful in practice. In this work, we identify two key properties related to the contrastive loss: (1) alignment (closeness) of features from positive pairs, and (2) uniformity of the induced distribution of the (normalized) features on the hypersphere. We prove that, asymptotically, the contrastive loss optimizes these properties, and analyze their positive effects on downstream tasks. Empirically, we introduce an optimizable metric to quantify each property. Extensive experiments on standard vision and language datasets confirm the strong agreement between both metrics and downstream task performance. Remarkably, directly optimizing for these two metrics leads to representations with comparable or better performance at downstream tasks than contrastive learning. Project Page: https://ssnl.github.io/hypersphere Code: https://github.com/SsnL/align_uniform
Are Gabor Kernels Optimal for Iris Recognition

Gabor kernels are widely accepted as dominant filters for iris recognition. In this work we investigate, given the current interest in neural networks, if Gabor kernels are the only family of functions performing best in iris recognition, or if better filters can be learned directly from iris data. We use (on purpose) a single-layer convolutional neural network as it mimics an iris code-based algorithm. We learn two sets of data-driven kernels; one starting from randomly initialized weights and the other from open-source set of Gabor kernels. Through experimentation, we show that the network does not converge on Gabor kernels, instead converging on a mix of edge detectors, blob detectors and simple waves. In our experiments carried out with three subject-disjoint datasets we found that the performance of these learned kernels is comparable to the open-source Gabor kernels. These lead us to two conclusions: (a) a family of functions offering optimal performance in iris recognition is wider than Gabor kernels, and (b) we probably hit the maximum performance for an iris coding algorithm that uses a single convolutional layer, yet with multiple filters. Released with this work is a framework to learn data-driven kernels that can be easily transplanted into open-source iris recognition software (for instance, OSIRIS - Open Source IRIS).
Single and Multi‐Mode Directional Lasing from Arrays of Dielectric Nanoresonators

The strong electric and magnetic resonances in dielectric subwavelength structures have enabled unique opportunities for efficient manipulation of light-matter interactions. Besides, the dramatic enhancement of nonlinear light-matter interactions near so-called bound states in the continuum (BICs) has recently attracted enormous attention due to potential advancements in all-optical and quantum computing. However, the experimental realizations and the applications of high- Q factor resonances in dielectric resonances in the visible regime have thus far been considerably limited. In this work, we explore the interplay of electric and magnetic dipoles in arrays of dielectric nanoresonators to enhance light-matter interaction. We report on the experimental realization of high-Q factor resonances in the visible through the collective diffractive coupling of electric and magnetic dipoles. Providing direct physical insights, we also show that coupling the Rayleigh anomaly of the array with the electric and magnetic dipoles of the individual nanoresonators can result in the formation of different types of BICs. We utilize the resonances in the visible regime to achieve lasing action at room temperature with high spatial directionality and low threshold. Finally, we experimentally demonstrate multi-mode, directional lasing and study the BIC-assisted lasing mode engineering in arrays of dielectric nanoresonators. We believe that our results enable a new range of applications in flat photonics through realizing on-chip controllable single and multi-wavelength micro-lasers.
Inequality and Happiness: Are Europeans and Americans Different?

We study the effect of the level of inequality in society on individual well-being using a total of 123,668 answers to a survey question about ‘‘happiness’’. We find that individuals have a lower tendency to report themselves happy when inequality is high, even after controlling for individual income, a large set of personal characteristics, and year and country (or, in the case of the US, state) dummies. The effect, however, is more precisely defined statistically in Europe than in the US. In addition, we find striking differences across groups. In Europe, the poor and those on the left of the political spectrum are unhappy about inequality; whereas in the US the happiness of the poor and of those on the left is uncorrelated with inequality. Interestingly, in the US, the rich are bothered by inequality. Comparing across continents, we find that left-wingers in Europe are more hurt by inequality than left-wingers in the US. And the poor in Europe are more concerned with inequality than the poor in America, an effect that is large in terms of size but is only significant at the 10% level. We argue that these findings are consistent with the perception (not necessarily the reality) that Americans have been living in a mobile society, where individual effort can move people up and down the income ladder, while Europeans believe that they live in less mobile societies. D 2003 Published by Elsevier B.V.
Affirmative Action for LGBT Applicants & Employees: A Proposed Regulatory Scheme

The “ENDA Executive Order” would require federal contractors to take affirmative action to recruit and employ lesbian, gay, bisexual, and transgender (“LGBT”) individuals. If the ENDA Executive Order is signed into law, the Office of Federal Contract Compliance Programs (“OFCCP”) would be tasked with developing the regulations to implement it without having had the benefit of public debate. This article seeks to begin that debate by proposing a set of regulations that would effectuate the purpose of the ENDA Executive Order (e.g., equal employment opportunity for LGBT individuals) without overburdening contractors. With recognition that LGBT employment discrimination laws are novel in the federal context, the article begins broadly with the need for a uniform, federal definition of “sexual orientation,” “gender identity,” “gender expression,” and “sex” to ensure that no one who identifies as LGBT slips through the cracks. Next the article introduces the components of affirmative action plans required by Executive Order 11,246, Section 503 of the Rehabilitation Act of 1973, and the Vietnam Era Veterans’ Readjustment Assistance Act of 1974, and analyzes which components would work as elements of the regulations implementing the ENDA Executive Order. For example, a detailed examination of the two traditional statistical tests required by Executive Order 11,246 – the Utilization Analysis and the Adverse Impact Analysis – demonstrates that both tests, while appropriate analytic tools in the context of race and sex, are entirely inappropriate in the context of sexual orientation, gender identity, and gender expression. Moreover, the article proposes programs and policies tailored to achieving equal employment opportunity for LGBT individuals. These include policies that would ensure the availability of domestic partnership benefits for LGBT employees, afford employees family and medical leave time to care for same-sex partners and their children, prevent federal contractors from enrolling in health insurance benefits programs that deny coverage for treatments and services related to sex affirmation or reassignment, allow transgender employees to access restroom facilities that correspond to their gender expression, and provide for such employees an appropriate dress code and transitioning policy. Ultimately, the article concludes that the regulations implementing the ENDA Executive Order should look markedly different from any of the regulations OFCCP has adopted before. Nonetheless, if the regulations implementing the ENDA Executive Order are crafted prudently, they could advance equal employment opportunity for LGBT applicants and employees without unnecessarily burdening the businesses they regulate.
From leadership-as-practice to leaderful practice:

Consistent with views that see leadership emerging from social practices rather than from the external mind, this paper contributes to an emerging movement in leadership studies known as ‘leadershi...
Forcing Analogies in Law: Badiou, Set Theory, and Models

Why think about set theory as part of legal studies? In particular, is there value in reading works by Alain Badiou, such as Being and Event,1 as speaking to law? This is the general question considered by this essay. By “law” I mean to designate juridical law, unless otherwise indicated. Being and Event makes many claims and distinctions. I focus on a few: first, the claim that equates mathematics with ontology; second, the distinction made among the one, the multiple, and multiplicities. In this regard, Badiou observes that traditional western metaphysics conceived of a multiple as dependent on the concept of the one. He identifies the work of mathematician Paul Cohen as providing a conceptual framework for thinking about multiplicities independent of reliance on the concept of the one (i.e. without the need for a prior concept of individuals). Cohen’s innovation was to introduce the technique of “forcing” to prove that the traditional axioms of set theory are consistent with the negation of the continuum hypothesis.4 Previously, Kurt Godel had proved that the traditional axioms of set theory are consistent with the truth of the continuum hypothesis.5 Together, the results of Godel
Religion, clubs, and emergent social divides

Arguments for and against the existence of an American cultural divide are frequently placed in a religious context. This paper seeks to establish that, all politics aside, the American religious divide is real, that modern religious polarization is not a uniquely American phenomenon, and that religious divides can be understood as naturally emergent within the club theory of religion. Analysis of the 2005 Baylor Religion reveals a bimodal distribution of religious commitment in the US. International survey data reveals bimodal distributions in twenty-eight of thirty surveyed countries. The club theory of religion, when applied in a multi-agent model, generates bimodal distributions of religious commitment whose emergence correlates to substitutability of club goods for standard goods and the mean population wage rate. Ramifications of religious bimodality include potential instability of majority rule electoral outcomes. Median estimators, such as majority rule democracy, are non-robust with bimodal distributions. When religion is politically salient and polarized, small errors can disproportionately shift the election result from the preferences of the median voter.
Development and the Changing Dynamics of Global Production: Global Value Chains and Local Clusters in Apparel Manufacturing

Abstract Focusing on the apparel industry, this article contends that the global manufacturing context increasingly obliges developing countries to construct or promote regionalised production sites aiming to capitalise on local institutional assets. The dissemination of standardised business practices and procedures by leading multinational firms to their main suppliers has played a critical role in driving this trend. Changes in recent decades in global apparel production as well as new, high-tech systems of supply-chain management are compelling retailers to source from local 'clusters' of interrelated firms and institutions. At the same time, this trend may contradict the key contentions of the locally-oriented cluster approach because the adoption of similar apparel contracting, assembly and delivery procedures in diverse developing regions can undercut the logic of emphasising local institutional assets. The rising importance of inter-linked clusters in the global apparel industry supports theoretic...
The Demand for Hours of Labor: Direct Evidence from California

California's longstanding requirement that most women receive time-and-a-half pay for workhours beyond eight in one day was extended to men in 1980. Analyzing Current Population Survey data from 1973, 1985, and 1991, we find that this overtime penalty substantially reduced the amount of daily overtime worked by California men relative to men in other states. Comparisons that use women to control for California-specific shocks show even stronger effects. The estimates imply a price elasticity of demand for overtime hours of at least 20.5.
The transfer of human capital

Abstract Most of our productive knowledge was handed down to us by previous generations. The transfer of knowledge from the old to the young is therefore a cornerstone of productivity growth. We study this process in a model in which the old sell knowledge to the young — old agents train the young, and charge them for this service. We take an information-theoretic approach in which training occurs if a young agent watches an old agent perform a task. Equilibrium is not constrained Pareto optimal. The old have private information, and this gives rise to an adverse selection problem: some old agents manage to sell skills that the planner would prefer to extinguish so as to allow more young agents to start new technologies. In this sense, there is too much resistance to change.
Rethinking Extraordinary Circumstances

This short Essay seeks to rationalize the “extraordinary circumstances” requirement of Rule 60(b)(6) of the Federal Rules of Civil Procedure. Under the Ackermann rule, courts have held that any extraordinary circumstances must not have been caused by the movant’s own litigation conduct. I argue that the Ackermann rule, at its broadest, would be unjust to those litigants most in need of Rule 60(b)(6) relief and would overserve finality interests. A case study of the recent Fourth Circuit case Aikens v. Ingram illustrates these points. I propose, contrary to Aikens, that the Ackermann rule apply more narrowly: only to movants who have intentionally abandoned their litigation. AUTHOR—Associate Professor of Law, William & Mary Law School. † This Essay was originally published in the Northwestern University Law Review Colloquy on November 8, 2011, 106 NW. U. L. REV. COLLOQUY 111 (2011), http://www.law.northwestern.edu/ lawreview/colloquy/2011/23/LRColl2011n23Dodson.pdf. N O R T H W E S T E R N U N I V E R S I T Y L A W R E V I E W 378 INTRODUCTION 378 I. RULE 60(B)(6) 379 II. A CASE STUDY: AIKENS V. INGRAM 381 III. BALANCING RULE 60(B)(6) WITH ACKERMANN 384 CONCLUSION 386
What Constitutes an "Agreement in Writing" in International Commercial Arbitration? Conflicts between the New York Convention and the Federal Arbitration Act

This Article investigates whether and to what extent a party must produce an “agreement in writing” when seeking to enforce an international arbitration agreement or award in a U.S. federal court. This issue has recently given rise to both a circuit split and a petition for certiorari to the U.S. Supreme Court, and involves matters of formal validity as well as federal subject matter jurisdiction. The problem arises out of subtle differences in the way an “agreement in writing” is defined in the Federal Arbitration Act (FAA) and the 1958 United Nations Convention on the Recognition and Enforcement of Foreign Arbitral Awards (New York Convention). This is not just a U.S. problem, however. Questions relating to form requirements under the New York Convention have also been much discussed at the international level, with UNCITRAL recently issuing a formal recommendation on how to deal with the problem.This Article describes the scope of the current problems associated with form requirements, including how inconsistencies in domestic practice affect international commercial arbitration and global trade. After discussing the difficulties in both the U.S. and the international sphere, the Article makes a number of suggestions for legislative and judicial reform. This is the first article to discuss the circuit split and associated issues in the context of the FAA and to take a serious comparative look at the implementation of the UNCITRAL recommendation at the international level.
Unitary Law Re-form, Pluralistic Law Re-Substance: Illuminating Legal Change

The theme of this symposium, Law Making in a Global World, can be iterated in two ways, depending on how one understands the term "law making." We might imagine how "globalization" affects the manner in which domestic law is conceived, instantiated, brought into force, interpreted, and applied. Or we might imagine how "global law" as transnational law is itself conceived, instantiated, brought into force, interpreted, and applied. The very possibility of these two readings, which signals the internal and external dimensions of legal change, evokes the central ideas I seek to develop in the two main Parts of this article.
Where did Black Jurors Go? A Theoretical Synthesis of Racial Disenfranchisement in the Jury System and Jury Selection:

system evolved as an essential ingredient of America's judicial framework. In recent years, however, frailties of the jury sys­tem in respect to its lack of fairness for women, Blacks, Latinos, and the poor have increasingly become the center of controversy. Fed­eral law is dear that these groups have the right to participate in court as jurors, according to two key concepts: There must be a ran­dom selection of jurors, and it must be representative within speci­fied geographic districts wherein a particwar court convenes (U.S. 90th Congress House Report, 1968: Section 1961). The logic is that qualified residents of a given geographic domain should be part of the pool from which a jury is selected-on the basis of a chance­opportunity for each to serve on a jury panel. Recent U.S. Supreme Court decisions have held that any substantial violation of these basic requirements of representativeness in jury selection is a prima facie case of discrimination (Alker & Barnard, 1978; Fukurai & Buder, 1987; Fukarai, Buder, & Krooth, in press; Horowitz, 1980).