cssi/SciSciGPT-SciSciNet huggingface dataset:
STUDYING ATMOSPHERE-DOMINATED HOT JUPITER KEPLER PHASE CURVES: EVIDENCE THAT INHOMOGENEOUS ATMOSPHERIC REFLECTION IS COMMON

We identify three Kepler transiting planets, Kepler-7b, Kepler-12b, and Kepler-41b, whose orbital phase-folded light curves are dominated by planetary atmospheric processes including thermal emission and reflected light, while the impact of non-atmospheric (i.e., gravitational) processes, including beaming (Doppler boosting) and tidal ellipsoidal distortion, is negligible. Therefore, those systems allow a direct view of their atmospheres without being hampered by the approximations used in the inclusion of both atmospheric and non-atmospheric processes when modeling the phase-curve shape. We present here the analysis of Kepler-12b and Kepler-41b atmosphere based on their Kepler phase curve, while the analysis of Kepler-7b was already presented elsewhere. The model we used efficiently computes reflection and thermal emission contributions to the phase curve, including inhomogeneous atmospheric reflection due to longitudinally varying cloud coverage. We confirm Kepler-12b and Kepler-41b show a westward phase shift between the brightest region on the planetary surface and the substellar point, similar to Kepler-7b. We find that reflective clouds located on the west side of the substellar point can explain the phase shift. The existence of inhomogeneous atmospheric reflection in all three of our targets, selected due to their atmosphere-dominated Kepler phase curve, suggests this phenomenon is common. Therefore, it is also likely to be present in planetary phase curves that do not allow a direct view of the planetary atmosphere as they contain additional orbital processes. We discuss the implications of a bright-spot shift on the analysis of phase curves where both atmospheric and gravitational processes appear, including the mass discrepancy seen in some cases between the companion's mass derived from the beaming and ellipsoidal photometric amplitudes. Finally, we discuss the potential detection of non-transiting but otherwise similar planets, whose mass is too small to show a gravitational photometric signal, but their atmosphere is reflective enough to show detectable phase modulations.
Modularity of biochemical filtering for inducing sigmoid response in both inputs in an enzymatic AND gate.

We report the first systematic study of designed two-input biochemical systems as information processing gates with favorable noise transmission properties accomplished by modifying the gate’s response from a convex shape to sigmoid in both inputs. This is realized by an added chemical “filter” process, which recycles some of the output back into one of the inputs. We study a system involving the biocatalytic function of the enzyme horseradish peroxidase, functioning as an AND gate. We consider modularity properties, such as the use of three different input chromogens that when oxidized yield signal detection outputs for various ranges of the primary input, hydrogen peroxide. We also examine possible uses of different filter effect chemicals (reducing agents) to induce the sigmoid response. A modeling approach is developed and applied to our data, allowing us to describe the enzymatic kinetics in the framework of a formulation suitable for evaluating the noise-handling properties of the studied systems as...
Degrees of Self-Maps of Products

Every closed oriented manifold $M$ is associated with a set of integers $D(M)$, the set of self-mapping degrees of $M$. In this paper we investigate whether a product $M\times N$ admits a self-map of degree $d$, when neither $D(M)$ nor $D(N)$ contains $d$. We find sufficient conditions so that $D(M\times N)$ contains exactly the products of the elements of $D(M)$ with the elements of $D(N)$. As a consequence, we obtain manifolds $M\times N$ that do not admit self-maps of degree $-1$ (strongly chiral), that have finite sets of self-mapping degrees (inflexible) and that do not admit any self-map of degree $dp$ for a prime number $p$. Furthermore we obtain a characterization of odd-dimensional strongly chiral hyperbolic manifolds in terms of self-mapping degrees of their products.
The UV Upturn: From M32 to Distant Clusters

I review the observational constraints on the stars responsible for the upturn in the UV spectra of ellipticals, ranging from galaxies in the local Universe to distant clusters. In nearby galaxies, this UV upturn is produced by a minority population of extreme horizontal branch (EHB) stars, with the large variations observed in the UV-to-optical flux ratio driven by variations in the number of EHB stars, and not the type of UV-bright stars. Deep UV images of the nearest elliptical galaxy, M32, show that it has a well-populated EHB, even though it has the weakest UV upturn of any known elliptical galaxy. However, M32 suffers from a striking dearth of the hot post-HB stars expected from canonical evolutionary theory. As we observe to larger lookback times in more distant galaxy clusters, the UV upturn fades, as predicted by theories of stellar and galactic evolution, but does so gradually. Because the EHB stars do not appear suddenly in the Universe, their presence is likely driven by a large dispersion in the parameters that govern HB morphology.
Charge-Based Superconducting Digital Logic Family Using Quantum Phase-Slip Junctions

Superconducting digital computing systems, primarily involving Josephson junctions are actively being pursued as high performance and low energy dissipating alternatives to CMOS-based technologies for petascale and exascale computers, although several challenges still exist in overcoming barriers to practically implement these technologies. In this paper, we present an alternative superconducting logic structure: quantized charge-based logic circuits using quantum phase-slip junctions, which have been identified as dual devices to Josephson junctions. Basic principles of logic implementation using quantum phase-slips are presented in simulations with the help of a SPICE model that has been developed for the quantum phase-slip structures. Circuit elements that form the building blocks for complex logic circuit design are introduced. Two different logic gate designs: or gate and xor gate are presented to demonstrate the usage of the building blocks introduced.
Euler–Bessel and Euler–Fourier transforms

We consider a topological integral transform of Bessel (concentric isospectral sets) type and Fourier (hyperplane isospectral sets) type, using the Euler characteristic as a measure. These transforms convert constructible -valued functions to continuous -valued functions over . Core contributions include: the definition of the topological Bessel transform, a relationship in terms of the logarithmic blowup of the topological Fourier transform and a novel Morse index formula for the transforms. We then apply the theory to problems of target reconstruction from enumerative sensor data, including localization and shape discrimination. This last application utilizes an extension of spatially variant apodization to mitigate sidelobe phenomena.
Ultrafast Spin-Transfer-Torque Switching of Synthetic Ferrimagnets

The state-of-the-art switching speeds of spin-transfer-torque-driven free layers in magnetic tunnel junctions (MTJs) are of the order of a few hundred picoseconds, hindering their wide implementation in memory and logic devices. To significantly speed up the spin-torque-driven reversal time, we propose a composite free-layer structure using synthetic ferrimagnets (SFMs). It is commonly assumed that to achieve a given switching delay, the current must exceed the critical current by a certain factor; therefore a higher critical current implies a higher switching current. We show that this is not the case for SFM structures, and that they can provide significantly reduced switching delays for a given current density even though the critical current is increased. This non-intuitive result can be understood from the requirements of angular momentum conservation. We predict that a 20 nm diameter MTJ incorporating the proposed SFM free layer can be switched in tens of picoseconds, which could advance the state-of-the-art of sub-200 ps switching. We show that this speed can be achieved by experimentally demonstrated parameters using current perpendicular magnetic anisotropy materials.
ZERO MODE DIVERGENCE PROBLEM IN STRING THEORY

For 2D string theory, the perturbative S-matrices are not well-defined due to a zero mode divergence. Although there exist formal procedures to make the integral convergent, their physical meanings are not clear. We describe a method to obtain finite S-matrices physically to justify the formal schemes. The scheme uses asymptotic states by wave packets which fall faster than exponentials. It is shown that the scheme gives well-defined S-matrices and justifies the formal shifted Virasoro-Shapiro amplitude for simple processes. The tree-level unitarity for these processes is also shown. We point out a problem in this scheme.
Fault in your stars: an analysis of Android app reviews

Mobile app distribution platforms such as Google Play Store allow users to share their feedback about downloaded apps in the form of a review comment and a corresponding star rating. Typically, the star rating ranges from one to five stars, with one star denoting a high sense of dissatisfaction with the app and five stars denoting a high sense of satisfaction.Unfortunately, due to a variety of reasons, often the star rating provided by a user is inconsistent with the opinion expressed in the review. For example, consider the following review for the Facebook App on Android; "Awesome App". One would reasonably expect the rating for this review to be five stars, but the actual rating is one star!Such inconsistent ratings can lead to a deflated (or inflated) overall average rating of an app which can affect user downloads, as typically users look at the average star ratings while making a decision on downloading an app. Also, the app developers receive a biased feedback about the application that does not represent ground reality. This is especially significant for small apps with a few thousand downloads as even a small number of mismatched reviews can bring down the average rating drastically.In this paper, we conducted a study on this review-rating mismatch problem. We manually examined 8600 reviews from 10 popular Android apps and found that 20% of the ratings in our dataset were inconsistent with the review. Further, we developed three systems; two of which were based on traditional machine learning and one on deep learning to automatically identify reviews whose rating did not match with the opinion expressed in the review. Our deep learning system performed the best and had an accuracy of 92% in identifying the correct star rating to be associated with a given review.In another evaluation, we asked 23 end users to write reviews for any 5 apps that they had used recently. We got 115 reviews from 66 different mobile apps. Our deep learning system had an accuracy of 87%.Further, our study suggests that this problem is quite prevalent among apps. Across the ten apps used in our study, the mismatch percentage ranged from 16% to 26%.
Phenomenology with fluctuating quantum geometries in loop quantum cosmology

The goal of this paper is to probe phenomenological implications of large fluctuations of quantum geometry in the Planck era, using cosmology of the early universe. For the background (Friedmann, Lemaitre, Robertson, Walker) quantum geometry, we allow ‘widely spread’ states in which the relative dispersions are as large as $168 \% $ in the Planck regime. By introducing suitable methods to overcome the ensuing conceptual and computational issues, we calculate the power spectrum ${{P}_{\mathcal{R}}}(k)$ and the spectral index n ( )s( )(k) of primordial curvature perturbations. These results generalize the previous work in loop quantum cosmology which focused on those states which were known to remain sharply peaked throughout the Planck regime. Surprisingly, even though the fluctuations we now consider are large, their presence does not add new features to the final ${{P}_{\mathcal{R}}}(k)$ and n ( )s( )(k): within observational error bars, their effect is degenerate with a different freedom in the theory, namely the number of pre-inflationary e-folds ${{N}_{\text{B}\star}}$ between the bounce and the onset of inflation. Therefore, with regard to observational consequences, one can simulate the freedom in the choice of states with large fluctuations in the Planck era using the simpler, sharply peaked states, simply by allowing for different values of ${{N}_{\text{B}\,\star}}$ .
Schematic interactions with many degeneracies

In previous works, we examined the spectra for systems of two protons and two neutrons, in a single j shell calculation, by obtaining matrix elements from experiment. More recently, we considered the schematic interactions in the same model space. We continue in this vein here. The present work and the former can be regarded as two bookends on a bookshelf.
Experimental Synthetic Aperture Radar With Dynamic Metasurfaces

We investigate the use of a dynamic metasurface as the transmitting antenna for a synthetic aperture radar (SAR) imaging system. The dynamic metasurface consists of a 1-D microstrip waveguide with complementary electric resonator (cELC) elements patterned into the upper conductor. Integrated into each of the cELCs are two diodes that can be used to shift each cELC resonance out of band with an applied voltage. The aperture is designed to operate at $K$ -band frequencies (17.5–20.3 GHz). We experimentally demonstrate imaging with a fabricated metasurface aperture using well-known SAR modalities, showing image quality comparable to traditional antennas. The agility of this aperture allows it to operate in spotlight and stripmap SAR modes, as well as in a third modality inspired by computational imaging strategies. We describe the dynamic metasurface antenna’s operation in detail, demonstrate high-quality imaging in both 2-D and 3-D, and examine various tradeoffs governing the integration of dynamic metasurfaces in the future SAR imaging platforms.
Tailoring interdigitated back contacts for high-performance bifacial silicon solar cells

Photovoltaic (PV) cells have become one of the most promising renewable energy technologies. To make PV cells more competitive with incumbent technologies, higher power output densities are needed. One promising approach is to add bifaciality to existing monofacial PV devices, allowing more output power from the additional reflection of sunlight from the ground (albedo α). For example, bifaciality can be added to Silicon Heterojunction (SHJ) solar cells with Interdigitated Back Contacts (IBCs) by opening up the gaps between the back metal contacts, but the optimum gap ( w) that maximizes the power output is unknown. In this paper, we show that the optimum gap [ w=1−1+ααα+c−12] maximizes the IBC-SHJ bifacial power output [ P∝ (1+α) (1−2a/c)], where c is the ratio of output power density to power loss due to shadowing and Joule heating, The results are validated by self-consistent finite-element device modeling. For a typical α = 0.3, an optimized bifacial IBC SHJ cell will produce 17% more power output than state-of-the-art monofacial IBC SHJ cells. The results encourage development of bifacial IBC solar cells as a next generation PV technology.
GRMHD Simulations of Visibility Amplitude Variability for Event Horizon Telescope Images of Sgr A

NFS GRFP [DGE 1144085]; NASA/NSF TCAN [NNX14AB48G]; NSF [AST 1108753, AST 1312034, AST-1207752, AST-1440254, 1228509]
A KECK/HIRES STUDY OF KINEMATICS OF THE COLD INTERSTELLAR MEDIUM IN DWARF STARBURST GALAXIES

We have obtained high-resolution Echelle spectra (R = 30,000-50,000) of the Na D absorption doublet (λλ5890, 5896) for six dwarf starburst galaxies and two more luminous starbursts: M82 and NGC 1614. The absorption features were separated into multiple components and separated into stellar and interstellar parts on the basis of kinematics. We find that three of the dwarfs show outflows, with an average blueshift of 27 km s-1. This is small compared with the highest velocity components in NGC 1614 and M82 (blueshifted by 150 and 91 km s-1, respectively); these two brighter galaxies also show more complex absorption profiles than the dwarfs. None of the outflow speeds clearly exceed the escape velocity of the host galaxy. Sight lines in NGC 2363 and NGC 4214 apparently intersect expanding shells. We compare the shocked gas velocity (vNa D) with the ionized gas velocity (vHα) and interpret the velocity difference as either a trapped ionization front (NGC 4214) or a leaky H II region (NGC 2363). The dwarfs show NNa D = 1011.8-1013.7cm-2, while the Na D columns in M82 and NGC 1614 are 1013.7 and 1014.0 cm-2, respectively. The mass of expelled gas is highly sensitive to outflow geometry, dust depletion, and ionization fraction, but with a simple shell model we estimate neutral outflow gas masses from ~106 to ~1010 M☉.
Narrow-Linewidth Homogeneous Optical Emitters in Diamond Nanostructures via Silicon Ion Implantation

Color centers in diamond provide a promising platform for quantum optics in the solid state, but often their desirable properties are spoiled when they are incorporated into actual devices. The authors demonstrate a simple technique to create centers with uniformly high-quality optical properties, even inside nanoscale devices. Their method may well open the gates for quantum information processing based on this type of hardware.
Auslander algebras which are tilted

Let A be an Auslander algebra of global dimension equal to 2. We provide a necessary and sufficient condition for A to be a tilted algebra. In particular, A is a tilted algebra if and only if $${{\,\mathrm{pd}\,}}_{A}(\tau _{A}\Omega _{A}DA)\le 1$$ .
ARE THE ULTRA-FAINT DWARF GALAXIES JUST CUSPS?

We develop a technique to investigate the possibility that some of the recently discovered ultra-faint dwarf satellites of the Milky Way might be cusp caustics rather than gravitationally self-bound systems. Such cusps can form when a stream of stars folds, creating a region where the projected two-dimensional surface density is enhanced. In this work, we construct a Poisson maximum likelihood test to compare the cusp and exponential models of any substructure on an equal footing. We apply the test to the Hercules dwarf (d {approx} 113 kpc, M{sub V} {approx} -6.2, e {approx} 0.67). The flattened exponential model is strongly favored over the cusp model in the case of Hercules, ruling out at high confidence that Hercules is a cusp catastrophe. This test can be applied to any of the Milky Way dwarfs, and more generally to the entire stellar halo population, to search for the cusp catastrophes that might be expected in an accreted stellar halo.
Speech Separation Using Partially Asynchronous Microphone Arrays Without Resampling

We consider the problem of separating speech sources captured by multiple spatially separated devices, each of which has multiple microphones and samples its signals at a slightly different rate. Most asynchronous array processing methods rely on sample rate offset estimation and resampling, but these offsets can be difficult to estimate if the sources or microphones are moving. We propose a source separation method that does not require offset estimation or signal resampling. Instead, we divide the distributed array into several synchronous subarrays. All arrays are used jointly to estimate the time-varying signal statistics, and those statistics are used to design separate time-varying spatial filters in each array. We demonstrate the method for speech mixtures recorded on both stationary and moving microphone arrays.
The Color and Stellar Mass Dependence of Small-scale Galaxy Clustering in SDSS-III BOSS

We measure the correlation of clustering to color and stellar mass in spectroscopic galaxies at 0.6 or < 2.35). We find the ratio of these coefficients, wred/wblue, to be 1.921 ± 0.11 in our smallest annulus of 75-125 kpc. At our largest radii (2-4 Mpc), we find wred/wblue to be 1.243 ± 0.05. Red galaxies therefore have denser environments that their blue counterparts at z ≈ 0.625, and this effect heightens with decreasing radius. Irrespective of color, we find that w does not obey a simple power law relation with radius, showing a dip around 1 Mpc attributable to the transition from oneto two-halo regimes in HOD models. Holding mass fixed, we find a clear differentiation between clustering in red and blue galaxies, showing that clustering is not solely determined by stellar mass. Holding color fixed, we find that clustering increases with mass, and that this relationship is especially strong in red galaxies at small scales (a factor of 2 effect).
A review of automatic differentiation and its efficient implementation

Derivatives play a critical role in computational statistics, examples being Bayesian inference using Hamiltonian Monte Carlo sampling and the training of neural networks. Automatic differentiation is a powerful tool to automate the calculation of derivatives and is preferable to more traditional methods, especially when differentiating complex algorithms and mathematical functions. The implementation of automatic differentiation however requires some care to insure efficiency. Modern differentiation packages deploy a broad range of computational techniques to improve applicability, run time, and memory management. Among these techniques are operation overloading, region based memory, and expression templates. There also exist several mathematical techniques which can yield high performance gains when applied to complex algorithms. For example, semi-analytical derivatives can reduce by orders of magnitude the runtime required to numerically solve and differentiate an algebraic equation. Open problems include the extension of current packages to provide more specialized routines, and efficient methods to perform higher-order differentiation.
Least Ambiguous Set-Valued Classifiers with Bounded Error Levels

In most classification tasks, there are observations that are ambiguous and therefore difficult to correctly label. Set-valued classifiers output sets of plausible labels rather than a single label...
Gaps in Protoplanetary Disks as Signatures of Planets: I. Methodology and Validation

We examine the observational consequences of partial gaps being opened by planets in protoplanetary disks. We model the disk using a static ?-disk model with detailed radiative transfer, parameterizing the shape and size of the partially cleared gaps based on the results of hydrodynamic simulations. Shadowing and illumination by stellar irradiation at the surface of the gap leads to increased contrast as the gap trough is deepened by shadowing and cooling and the far gap wall is puffed up by illumination and heating. In calculating observables, we find that multiple scattering is important and derive an approximation to include these effects. A gap produced by a 200 M ? (70 M ?) planet at 10?AU can lower/raise the midplane temperature of the disk by up to ~ ? 25%/+29% (~ ? 11/+ 19) by shadowing in the gap trough and illumination on the far shoulder of the gap. At the distance of Taurus, this gap would be resolvable with ~001 angular resolution. The gap contrast is most significant in scattered light and at thermal continuum wavelengths characteristic of the surface temperature, reducing or raising the surface brightness by up to order of magnitude. Since gap sizes are correlated with planet mass, this is a promising way of finding and determining the masses of planets embedded in protoplanetary disks.
Secure Control in Partially Observable Environments to Satisfy LTL Specifications

This paper studies the synthesis of control policies for an agent that has to satisfy a temporal logic specification in a partially observable environment, in the presence of an adversary. The interaction of the agent (defender) with the adversary is modeled as a partially observable stochastic game. The goal is to generate a defender policy to maximize satisfaction of a given temporal logic specification under any adversary policy. The search for policies is limited to the space of finite state controllers, which leads to a tractable approach to determine policies. We relate the satisfaction of the specification to reaching (a subset of) recurrent states of a Markov chain. We present an algorithm to determine a set of defender and adversary finite state controllers of fixed sizes that will satisfy the temporal logic specification, and prove that it is sound. We then propose a value-iteration algorithm to maximize the probability of satisfying the temporal logic specification under finite state controllers of fixed sizes. Lastly, we extend this setting to the scenario where the size of the finite state controller of the defender can be incre
Transforming and Projecting Images into Class-Conditional Generative Networks

We present a method for projecting an input image into the space of a class-conditional generative neural network. We propose a method that optimizes for transformation to counteract the model biases in generative neural networks. Specifically, we demonstrate that one can solve for image translation, scale, and global color transformation, during the projection optimization to address the object-center bias and color bias of a Generative Adversarial Network. This projection process poses a difficult optimization problem, and purely gradient-based optimizations fail to find good solutions. We describe a hybrid optimization strategy that finds good projections by estimating transformations and class parameters. We show the effectiveness of our method on real images and further demonstrate how the corresponding projections lead to better editability of these images. The project page and the code is available at https://minyoungg.github.io/GAN-Transform-and-Project/.
IFAA: Robust Association Identification and Inference for Absolute Abundance in Microbiome Analyses

The target of inference in microbiome analyses is usually relative abundance (RA) because RA in a sample (e.g., stool) can be considered as an approximation of RA in an entire ecosystem (e.g., gut)...
The economic performance of socialism

Socialism is attracting renewed interest. But forced economic equality comes with significant economic costs. I conduct an empirical evaluation on the performance of major socialist economies in me...
Distributionally Robust Learning

Many of the modern techniques to solve supervised learning problems suffer from a lack of interpretability and analyzability that do not give rise to rigorous mathematical results. This monograph develops a comprehensive statistical learning framework that uses Distributionally Robust Optimization (DRO) under the Wasserstein metric to ensure robustness to perturbations in the data. The authors introduce the reader to the fundamental properties of the Wasserstein metric and the DRO formulation, before explaining the theory in detail and its application. They cover a series of learning problems, including (i) distributionally robust linear regression; (ii) distributionally robust regression with group structure in the predictors; (iii) distributionally robust multi-output regression and multiclass classification; (iv) optimal decision making that combines distributionally robust regression with nearest-neighbor estimation; (v) distributionally robust semi-supervised learning; (vi) distributionally robust reinforcement learning. Throughout the monograph, the authors use applications in medicine and health care to illustrate the theoretical ideas in practice. They include numerical experiments and case studies using synthetic and real data. Distributionally Robust Learning provides a detailed insight into a technique that has gained a lot of recent interest in developing robust supervised learning solutions that are founded in sound mathematical principles. It will be enlightening for researchers, practitioners and students working on the optimization of machine learning systems.
Fourier Neural Operator for Parametric Partial Differential Equations

The classical development of neural networks has primarily focused on learning mappings between finite-dimensional Euclidean spaces. Recently, this has been generalized to neural operators that learn mappings between function spaces. For partial differential equations (PDEs), neural operators directly learn the mapping from any functional parametric dependence to the solution. Thus, they learn an entire family of PDEs, in contrast to classical methods which solve one instance of the equation. In this work, we formulate a new neural operator by parameterizing the integral kernel directly in Fourier space, allowing for an expressive and efficient architecture. We perform experiments on Burgers' equation, Darcy flow, and Navier-Stokes equation. The Fourier neural operator is the first ML-based method to successfully model turbulent flows with zero-shot super-resolution. It is up to three orders of magnitude faster compared to traditional PDE solvers. Additionally, it achieves superior accuracy compared to previous learning-based solvers under fixed resolution.
On the tightness of SDP relaxations of QCQPs

Quadratically constrained quadratic programs (QCQPs) are a fundamental class of optimization problems well-known to be NP-hard in general. In this paper we study conditions under which the standard semidefinite program (SDP) relaxation of a QCQP is tight. We begin by outlining a general framework for proving such sufficient conditions. Then using this framework, we show that the SDP relaxation is tight whenever the quadratic eigenvalue multiplicity, a parameter capturing the amount of symmetry present in a given problem, is large enough. We present similar sufficient conditions under which the projected epigraph of the SDP gives the convex hull of the epigraph in the original QCQP. Our results also imply new sufficient conditions for the tightness (as well as convex hull exactness) of a second order cone program relaxation of simultaneously diagonalizable QCQPs.
Speckle illumination SFDI for projector-free optical property mapping

Spatial frequency domain imaging can map tissue scattering and absorption properties over a wide field of view, making it useful for clinical applications such as wound assessment and surgical guidance. This technique has previously required the projection of fully characterized illumination patterns. Here, we show that random and unknown speckle illumination can be used to sample the modulation transfer function of tissues at known spatial frequencies, allowing the quantitative mapping of optical properties with simple laser diode illumination. We compute low- and high-spatial frequency response parameters from the local power spectral density for each pixel and use a lookup table to accurately estimate absorption and scattering coefficients in tissue phantoms, in vivo human hand, and ex vivo swine esophagus. Because speckle patterns can be generated over a large depth of field and field of view with simple coherent illumination, this approach may enable optical property mapping in new form-factors and applications, including endoscopy.
The Response of the Informal Sector to Trade Liberalization

This paper studies the relationship between trade liberalization and informality. It is often claimed that increased foreign competition in developing countries leads to an expansion of the informal sector, defined as the sector that does not comply with labor market legislation. Using data from two countries that experienced large trade barrier reductions in the 1980’s and 1990’s, Brazil and Colombia, we examine the response of the informal sector to liberalization. In Brazil, we find no evidence of a relationship between trade policy and informality. In Colombia, we do find evidence of such a relationship, but only for the period preceding a major labor market reform that increased the flexibility of the Colombian labor market. These results point to the significance of labor market institutions in assessing the effects of trade policy on the labor market.
Marriage Equality, Gender Equality, and the Women's Convention

"Marriage equality" remains an elusive goal in this country. About ten years ago I wrote an article suggesting that private ordering would be a good alternative to the rather haphazard and arbitrary state law governing marriage. Instead, I urged couples to draft their own "marriage proposals." As an example, I attached a "Gender Equity Marriage Proposal." The idea was that "gender equity" might be of some interest to some couples, just as others might be more concerned with a child-centered (or wealth- or environment-centered) model. I meant well. But my premise was deeply flawed for at least two reasons. First, "gender equity" is not a private preference, like chocolate or vanilla. Rather, like racial equality, it is a fundamental right, an irreducible principle, in the private as well as the public sphere. Second, as a corollary, the notion that private parties might contract their way around gendered norms despite the ubiquity of such norms in the workplace, the culture, and the law seems naive if not delusional in hindsight. This Article takes a different tack. It argues, as many have, that marriage equality — at least as it refers to equality within heterosexual marriages — requires gender equality. It argues further, however, that United States law cannot assure gender equality because of its pinched, narrow conception of "rights." Those seeking marriage equality in the United States, accordingly, should look to international human rights law, specifically, the Convention on the Elimination of All Forms of Discrimination against Women (CEDAW).
Communities, Texts, and Law: Reflections on the Law and Literature Movement

How do we form communities? How might we form better ones? What is the role of law in that process? In a recent series of books and articles, James Boyd White, arguably the modern law and literature movement's founder, has put forward distinctively literary answers to these questions. Perhaps because of the fluidity of the humanities, White's account of the nature of community is not nearly as axiomatic to the law and literature movement as is Posner's depiction of the "individual" to legal economists. Nevertheless, White's conception is increasingly representative of the literary-legalist's world view. Furthermore, with the exception of Richard Weisberg, White has very little competition within the movement itself. This article explores and criticizes that vision. Second, it puts forward an alternative account of how we form communities, how we might form better ones, and how law would function within them.
Stress-testing Africa's recent growth and poverty performance

Abstract After an impressive acceleration in growth and poverty reduction since the mid-1990s, many African countries continue to register robust growth in the aftermath of the global financial crisis. Will this growth persist, given the tepid recovery in developed countries, numerous weather shocks, and civil conflicts in Africa? This paper “stress tests” African economies. The findings indicate that Africa's long-term growth is fairly impervious to a prolonged recession in high-income countries. Growth is, however, much more sensitive to a disruption of capital flows to the region, and to internal shocks, such as civil conflict and drought, even if the latter follow historical patterns. The broad policy implication is that with proper domestic production conditions African countries can sustain robust long-term growth. Because of the economic dominance of the agriculture sector and the share of food in household budgets, countries will need to increase the resilience of agriculture and protect it from unfavorable climate change impacts, such as drought. As in the past, civil conflicts and violence will pose by far the greatest threat to Africa's performance.
Commitment and Consequences: Reneging on Cosponsorship Pledges in the U.S. House

We argue that bill cosponsorship in Congress represents an institutional arrangement that provides credibility to commitments of support. We predict that if cosponsorship fosters legislative deals, MCs will only rarely back out on their pledges to support a bill if it comes up for a floor vote, and when they do, these choices will reflect strategic calculations. Further, legislators who violate their cosponsorship agreements will face punishment from colleagues, compromising their ability to gain support for their own bills. We explore the causes and effects of MCs' choices to renege on a pledge by voting no on a bill for which they were a cosponsor, focusing on all cosponsorship decisions in the 101st–108th Houses. The results reveal that patterns of reneging and its consequences are consistent with the idea that cosponsorship functions as a commitment mechanism.
Innovation and Incentives: Evidence from Corporate R&D

Abstract Beginning in the late 1980s, American corporations began increasingly linking the compensation of central research personnel to the economic objectives of the corporation. This paper examines the impact of the shifting compensation of the heads of corporate research and development. Among firms with centralized R&D organizations, a clear relationship emerges: more long-term incentives (such as stock options and restricted stock) are associated with more heavily cited patents. These incentives also appear to be associated with more patent awards and patents of greater originality. Short-term incentives appear to be unrelated to measures of innovation.
Corporate Governance, Audit Quality, and the Sarbanes‐Oxley Act: Evidence from Internal Audit Outsourcing

This study extends current literature related to nonaudit services by investigating internal audit outsourcing to the external auditor. We posit that certain types of internal audit outsourcing (i.e., those which are nonroutine, and thus tend to be nonrecurring in nature) are unlikely to lead to economic bonding, while offering significant potential for improvements in audit coverage and scope when provided by the external auditor. Alternatively, outsourcing routine internal audit tasks is more likely to lead to economic bonding, as well as potentially threatening internal auditor independence. Our results are consistent with firms with independent, active, and expert audit committees being less likely to outsource routine internal auditing activities to the external auditor. However, the outsourcing of nonroutine internal audit activities such as special projects and EDP consulting are not negatively related to effective audit committees. Additionally, outsourcing of either type of internal audit activit...
Automated Finance: The Assumptions and Behavioral Aspects of Algorithmic Trading

Automated trading now dominates the financial markets. Yet no philosophy of academic research into the topic exists. As the growth in automated trading suggests their greater returns and predictability, this paper examines stability and statistical control of trading process outputs as method of justifying predictions of future performance. New assumptions presented can form a foundation for positive research under this revolutionary paradigm, one almost completely ignored in the financial literature. The traditional financial literature rests on the assumption of normality of inputs, while trading systems aspire to the more rigorous engineering standard of justification. The end game is that now behavioral aspects, not of traders but of trading system research and development projects, drive market returns.
Advancing the Empirical Research on Lobbying

This review identifies empirical facts about lobbying that are generally agreed upon in the literature. It then discusses challenges to empirical research in lobbying and provides examples of empirical methods that can be employed to overcome these challenges—with an emphasis on statistical measurement, identification, and casual inference. The article then discusses the advantages, disadvantages, and effective use of the main types of data available for research in lobbying. It closes with a number of open questions for researchers in the field and avenues for future work to advance empirical research on lobbying.
Information system precision and honesty in managerial reporting: A re-examination of information asymmetry effects

Abstract Hannan, Rankin, and Towry (2006, HRT hereafter) propose that an information system is capable of affecting honesty in the manager's budget report by reducing information asymmetry between the manager and the owner regarding the level of honesty in the budget. They find that going from no information system to a coarse information system increases honesty in managerial reporting. However, they also report evidence that going from a coarse information system to a precise information system decreases honesty in managerial reporting. We extend HRT's study in two ways. First, we extend their behavioral theory by incorporating the possibility that reducing information asymmetry could increase the manager's preference for honesty in the budget (Koford & Penno, 1992; Bicchieri, 2006). Second, we note that HRT held information system accuracy constant at a relatively low level, which is another source of information asymmetry. Thus, we test the robustness of HRT's negative precision result by manipulating information system precision and accuracy at two levels using a computerized version of their manual experiment. We find that information system precision increases honesty in managerial reporting and that this positive precision effect is weaker under low information system accuracy. A supplemental analysis suggests that our data are generally similar to HRT's data in our two low accuracy conditions and that their negative precision result is attributable to an unusual period effect in their coarse information system condition.
Sexual Orientation: A Plea for Inclusion

White women and people of color have made significant scholarly contribution toward a better understanding of patriarchy and racial hegemony. Other outsider scholars, such as lesbians, gay men, and bisexuals, also have spoken out about how hegemony subordinates them to the dominant culture. That subordination creates a common pain of exclusion. All subordinated people should explore the sources of common pain that come from exclusion from the power and privilege generally enjoyed by members of the dominant culture.
Staying Alive: Executive Clemency, Equal Protection, and the Politics of Gender in Women's Capital Cases

Clemency in capital cases, once routine, has become a rare event in the contemporary death penalty era. Although the majority of state executives enjoy the traditional plenary power in clemency cases, very few have used it liberally. As use of the power has declined, the political risks of commutation have intensified. The contemporary governor contemplating a grant of clemency can anticipate considerable scrutiny of his or her use of the power. When a governor confronts the duty of deciding whether to allow a woman capital prisoner to be executed, he or she is additionally forced to navigate the politics of gender in the new age of formal sexual equality. The recent past has demonstrated that there is little for a governor to fear by way of adverse political consequences for permitting the execution of women. The execution of Karla Faye Tucker in Texas in 1998, was the first execution of a woman after a hiatus of fourteen years, and the first since the era of formal equality has been well established. It was surrounded by intense speculation about whether then Governor George W. Bush would be harmed politically by permitting the execution of a woman. Since the Tucker execution, four women have been executed with ever diminishing media interest in the executions and the impact on the careers of presiding executives. Governors have reason to be reassured that they will not be whipsawed should they allow the execution of a woman, caught between demands for even-handed gender justice and countervailing strong public sentiment for protective tenderness.
Chief Executive Officer Equity Incentives and Accounting Irregularities

This study examines whether Chief Executive Officer (CEO) equity-based holdings and compensation provide incentives to manipulate accounting reports. While several prior studies have examined this important question, the empirical evidence is mixed and the existence of a link between CEO equity incentives and accounting irregularities remains an open question. Because inferences from prior studies may be confounded by assumptions inherent in research design choices, we use propensity-score matching and assess hidden (omitted variable) bias within a broader sample. In contrast to most prior research, we do not find evidence of a positive association between CEO equity incentives and accounting irregularities after matching CEOs on the observable characteristics of their contracting environments. Instead, we find some evidence that accounting irregularities occur less frequently at firms where CEOs have relatively higher levels of equity incentives.
Time series decomposition and measurement of business cycles, trends and growth cycles

Abstract A study of business cycles does not require trend estimation and elimination, but a study of growth cycles does. Major cyclical slowdowns and speedups deserve to be analyzed, but the needed time series decomposition presents difficult problems, mainly because trends and cycles influence each other. We compare cyclical movements in levels, deviations from trend, and smoothed growth rates for both the quarterly real GDP and the monthly U.S. Coincident Index—using the phase average trend (PAT). Then we compare alternative trend estimates, deterministic and stochastic, linear and nonlinear, and the corresponding series of deviations from these trends. We discuss how the resulting estimates differ for U.S. growth cycles in the post-World War II period. The results of PAT show great similarity to the results obtained with the Hodrick–Prescott, local linear trend, band-pass filtering methods.
Vague comparisons and proportional sentencing

The “small improvement problem” (“the Problem”) applies when no option in a comparison is best nor, it seems, are the options equal, because a small improvement to one would fail to make it the better choice. I argue that vagueness causes the Problem, such that the options are vaguely equal or vaguely “related.” I then unpack an important instance of the Problem, the comparison between a crime and a punishment upon which the ideal of a retributively deserved sentence is based. I argue that this comparison is not only vague, but remarkably vague, leading to an expansive array of “not undeserved” sentences. I conclude, however, that retributivism can only justify the least harmful “not undeserved” sentence.
The Efficiency of Controlling Corporate Self-Dealing: Theory Meets Reality

Introduction 396I. The Problem of Self-Dealing and Possible Solutions 399A. Self-Dealing and the Voting Mechanism 399B. Possible Solutions to Self-Dealing 4011. Prohibition on Self-Dealing 401
Extremely Poor Neighborhoods and Homicide

Objective. This study explores the wide variation in homicide rates among extremely poor neighborhoods. Methods. Using cross-sectional Census tract data for New York City (N= 2,042), the present analysis employs robust regression techniques to estimate the relationship between community resource deprivation and homicide for a subsample of 227 neighborhoods with poverty rates 40 percent and greater. Results. The main finding is that even at extreme levels of neighborhood poverty, variation in disadvantage is positively associated with variation in homicide rates. Moreover, the disadvantage-homicide relationship appears especially strong in extremely poor areas (and in predominately African-American neighborhoods). Conclusion. Consistent with W. J. Wilson's perspective on inner-city disadvantage, the results imply that reducing the concentration of poverty will reduce overall homicide rates.