cssi/SciSciGPT-SciSciNet huggingface dataset:
Whose rights? A critique of individual agency as the basis of rights

I argue that individuals may be as problematic political agents as groups are. In doing so, I draw on theory from economics, philosophy, and computer science and evidence from psychology, neuroscience, and biology. If successful, this argument undermines agency-based justifications for embracing strong notions of individual rights while rejecting the possibility of similar rights for groups. For concreteness, I critique these mistaken views by rebutting arguments given by Chandran Kukathas in his article `Are There Any Cultural Rights?' that groups lack the temporal coherence, political independence, and indivisibility of individuals. I also show how formal critiques of group agency from social science (in particular, Arrow's Impossibility Theorem) can be applied as reasonably to individuals as groups. Because these symmetries between groups and individuals undermine common implicit assumptions in political philosophy, I argue that they may have broader implications for liberal political theory, as they e...
Partons and jets at the LHC

I review some issues related to short distance QCD and its relation to the experimental program of the large hadron collider (LHC) now under construction in Geneva.
Universal Fluctuations in Dirac Spectra

We have argued that there is an intimate relation between correlations of Dirac eigenvalues and the breaking of chiral symmetry. In the chiral limit, the fermion determinant suppresses gauge field configurations with small Dirac eigenvalues. Correlations counteract this suppression, and are a necessary ingredient of chiral symmetry breaking. From the study of eigenvalue correlations in strongly interacting systems, we have concluded that they are described naturally with by Random Matrix Theory with the global symmetries of the physical system. In QCD, this led to the introduction of chiral Random Matrix Theories. They provided us with an analytical understanding of the statistical properties of the eigenvalues on the scale of a typical level spacing. In particular, impressive agreement between lattice QCD and chiral Random Matrix Theory was found for the microscopic spectral density and for spectral correlations in the bulk of the spectrum. An extension of this model to nonzero chemical potential explains some intriguing properties of previously obtained lattice QCD Dirac spectra and instanton liquid Dirac spectra.
Laurent polynomials, Eulerian numbers, and Bernstein's theorem

Erman, Smith, and Varilly-Alvarado (2011) showed that the expected number of doubly monic Laurent polynomials f(z)=z^-^m+a"-"m"+"1z^-^m^+^1+...+a"n"-"1z^n^-^1+z^n whose first m+n-1 powers have vanishing constant term is the Eulerian number , as well as a more refined result about sparse Laurent polynomials. We give an alternate proof of these results using Bernstein's theorem that clarifies the connection between these objects. In the process, we show that a refinement of Eulerian numbers gives a combinatorial interpretation for volumes of certain rational hyperplane sections of the hypercube.
On Principal Hessian Directions for Data Visualization and Dimension Reduction: Another Application of Stein's Lemma

Abstract Modern graphical tools have enhanced our ability to learn many things from data directly. With much user-friendly graphical software available, we are encouraged to plot a lot more often than before. The benefits from direct interaction with graphics have been enormous. But trailing behind these high-tech advances is the issue of appropriate guidance on what to plot. There are too many directions to project a high-dimensional data set and unguided plotting can be time-consuming and fruitless. In a recent article, Li set up a statistical framework for study on this issue, based on a notion of effective dimension reduction (edr) directions. They are the directions to project a high dimensional input variable for the purpose of effectively viewing and studying its relationship with an output variable. A methodology, sliced inverse regression, was introduced and shown to be useful in finding edr directions. This article introduces another method for finding edr directions. It begins with the observat...
GIB: imperfect information in a computationally challenging game

This paper investigates the problems arising in the construction of a program to play the game of contract bridge. These problems include both the difficulty of solving the game's perfect information variant, and techniques needed to address the fact that bridge is not, in fact, a perfect information game. GIB, the program being described, involves five separate technical advances: partition search, the practical application of Monte Carlo techniques to realistic problems, a focus on achievable sets to solve problems inherent in the Monte Carlo approach, an extension of alpha-beta pruning from total orders to arbitrary distributive lattices, and the use of squeaky wheel optimization to find approximately optimal solutions to cardplay problems. GIB is currently believed to be of approximately expert caliber, and is currently the strongest computer bridge program in the world.
US infant mortality and the President’s party

Background Infant mortality rates in the US exceed those in all other developed countries and in many less developed countries, suggesting political factors may contribute. Methods Annual time series on overall, White and Black infant mortality rates in the US were analysed over the 1965–2010 time period to ascertain whether infant mortality rates varied across presidential administrations. Data were de-trended using cubic splines and analysed using both graphical and time series regression methods. Results Across all nine presidential administrations, infant mortality rates were below trend when the President was a Democrat and above trend when the President was a Republican. This was true for overall, neonatal and postneonatal mortality. Regression estimates show that, relative to trend, Republican administrations were characterized by infant mortality rates that were, on average, 3% higher than Democratic administrations. In proportional terms, effect size is similar for US Whites and Blacks. US Black rates are more than twice as high as White, implying substantially larger absolute effects for Blacks. Conclusions We found a robust, quantitatively important association between net of trend US infant mortality rates and the party affiliation of the president. There may be overlooked ways by which macro-dynamics of policy impact microdynamics of physiology, suggesting the political system is a component of the underlying mechanism generating health inequality in the USA.
Designing information systems for nursing practice: data base and knowledge base requirements of different organizational technologies.

One of the major causes of failure of information system design is the failure of developers to take into account the organizational environment, thereby leading to an unusable system. The first step in designing an effective system is to describe the user's view of the system, a view that incorporates how the system will help users to manage information in their particular organizational environment. For nurses involved in designing a nursing information system, a useful way of considering the organizational environment is provided by Perrow [3]. The organizational technologies described by Perrow can be viewed as different models of nursing practice, each with particular requirements for a knowledge base and a data base. Nurses can identify the model that most closely corresponds to actual or desired nursing practice in their agencies and use the model's associated knowledge base and data base requirements as a guide to specifying the information system to be developed.
Constructing molecular complexity and diversity: total synthesis of natural products of biological and medicinal importance

The advent of organic synthesis and the understanding of the molecule as they occurred in the nineteenth century and were refined in the twentieth century constitute two of the most profound scientific developments of all time. These discoveries set in motion a revolution that shaped the landscape of the molecular sciences and changed the world. Organic synthesis played a major role in this revolution through its ability to construct the molecules of the living world and others like them whose primary element is carbon. Although the early beginnings of organic synthesis came about serendipitously, organic chemists quickly recognized its potential and moved decisively to advance and exploit it in myriad ways for the benefit of mankind. Indeed, from the early days of the synthesis of urea and the construction of the first carbon–carbon bond, the art of organic synthesis improved to impressively high levels of sophistication. Through its practice, today chemists can synthesize organic molecules—natural and designed—of all types of structural motifs and for all intents and purposes. The endeavor of constructing natural products—the organic molecules of nature—is justly called both a creative art and an exact science. Often called simply total synthesis, the replication of nature's molecules in the laboratory reflects and symbolizes the state of the art of synthesis in general. In the last few decades a surge in total synthesis endeavors around the world led to a remarkable collection of achievements that covers a wide ranging landscape of molecular complexity and diversity. In this article, we present highlights of some of our contributions in the field of total synthesis of natural products of biological and medicinal importance. For perspective, we also provide a listing of selected examples of additional natural products synthesized in other laboratories around the world over the last few years.
Risk-Based Auditing, Strategic Prompts, and Auditor Sensitivity to the Strategic Risk of Fraud

ABSTRACT: Under risk-based auditing, more (fewer) audit resources are allocated to accounts that are more (less) likely to be misstated. However, if auditors do not anticipate the strategic risk that arises when client managers anticipate auditors' risk-based resource allocations, undetected misstatements among ostensibly low-risk accounts could be more common than traditional risk assessment procedures suggest. Using a laboratory experiment, I find that participants assuming the auditor role in a stylized audit game do not naturally attune to strategic risks, but instead focus resources toward accounts with high non-strategic risk and away from ostensibly low-risk accounts. Manager-participants exploit these allocations by overriding the low-risk accounts more often than accounts with high non-strategic risk. However, auditor-participants who are asked to predict managers' expectations of, and responses to, audit resource allocations, devote additional resources to the low-risk accounts. These results a...
New process for enantioselective nucleophilic addition to aldehydes to form secondary alcohols

Abstract New methodology is described for the enantioselective conversion of aldehydes to anti aldols 4 and homoallylic alcohols 7.
A gas chromatographic instrument for measurement of hydrogen cyanide in the lower atmosphere

Abstract. A gas-chromatographic (GC) instrument was developed for measuring hydrogen cyanide (HCN) in the lower atmosphere. The main features of the instrument are (1) a cryogen-free cooler for sample dehumidification and enrichment, (2) a porous polymer PLOT column for analyte separation, (3) a flame thermionic detector (FTD) for sensitive and selective detection, and (4) a dynamic dilution system for calibration. We deployed the instrument for a ∼4 month period from January–June, 2010 at the AIRMAP atmospheric monitoring station Thompson Farm 2 (THF2) in rural Durham, NH. A subset of measurements made during 3–31 March is presented here with a detailed description of the instrument features and performance characteristics. The temporal resolution of the measurements was ~20 min, with a 75 s sample capture time. The 1σ measurement precision was
Status of the MINOS experiment

The author presents the status of the long baseline neutrino oscillation experiment MINOS at Fermi National Accelerator Laboratory (Fermilab). He also summarizes the status of the detector and beam construction, the expected event rates and sensitivity to physics. He also comments on possible future plans to improve the performance of the experiment.
Cryogenic Cable Dielectrics

In the search for cable designs capable of transmitting larger blocks of power, consideration has been given to replacing oil in the oil/paper cable with liquified gases. This paper reports the evaluation of liquid hydrogen as the substitute for oil. The system is not operated at the superconducting region but at higher temperatures. Not only cellulosic paper but synthetic papers and films were evaluated. The results were very encouraging.
Immersing almost geodesic surfaces in a closed hyperbolic three manifold

Let M^3 be a closed hyperbolic three manifold. We construct closed surfaces that map by immersions into M^3 so that for each, one the corresponding mapping on the universal covering spaces is an embedding, or, in other words, the corresponding induced mapping on fundamental groups is an injection.
Development of a Fillable, Tapered PET/CT Phantom

PET performance and image quality are degraded as body size increases; as size increases so do attenuation and background fractions. Based on simulated and acquired data, a fillable, tapered phantom was developed to measure PET scanner performance and image quality as a function of body size over a wide range of sizes. Design constraints included shape, cross-sectional dimensions, material, wall thickness, and taper angle. For fixed end sizes (as large as possible at one end and small at the other) a lower taper (narrow) leads to a long, heavy phantom. A higher taper (steep so that the diameter changes greatly within the scanner field of view) may not represent any particular cross section well. Monte Carlo simulations were performed to determine an acceptable taper angle that balanced the benefits and drawbacks of lower and higher taper rates. The simulations were validated with measurements on existing physical phantoms. Then, tapered phantoms with different angles and non-tapered phantoms, which had dimensions similar to the tapered phantoms, were simulated at different positions in the PET axial field of view to investigate properties of different taper angles. Scatter fractions of simulated tapered and non-tapered phantoms were compared. Of the different angles simulated, the results indicated that a 25° taper would yield a phantom that represents a continuum of cross-sectional dimensions while still being a practical size. The 25 ° tapered phantom was machined with an oval cross-section ranging from 38.5 cm × 49.5 cm to 6.8 cm × 17.8 cm, a length of 51.1 cm, a mass of 6 kg (empty) or 42 kg (water filled), and acrylic walls 1.25-cm thick. Initial PET/CT images were acquired.
Two‐step series estimation of sample selection models

Summary Sample selection models are important for correcting the effects of non-random sampling. This paper is about semiparametric estimation using a series approximation to the correction term. Regression spline and power series approximations are considered. Asymptotic normality and consistency of an asymptotic variance estimator are shown.
Almost tight upper bounds for vertical decompositions in four dimensions

We show that the complexity of the vertical decomposition of an arrangement of n fixed-degree algebraic surfaces or surface patches in four dimensions is O(n4+e), for any e > 0. This improves the best previously known upper bound for this problem by a near-linear factor, and settles a major problem in the theory of arrangements of surfaces, open since 1989. The new bound can be extended to higher dimensions, yielding the bound O(n2d−4+e), for any e > 0, on the complexity of vertical decompositions in dimensions d ≥ 4. We also describe the immediate algorithmic applications of these results, which include improved algorithms for point location, range searching, ray shooting, robot motion planning, and some geometric optimization problems.
On the half-cauchy prior for a global scale parameter

This paper argues that the half-Cauchy distribution should replace the inverseGamma distribution as a default prior for a top-level scale parameter in Bayesian hierarchical models, at least for cases where a proper prior is necessary. Our arguments involve a blend of Bayesian and frequentist reasoning, and are intended to complement the original case made by Gelman (2006) in support of the folded-t family of priors. First, we generalize the half-Cauchy prior to the wider class of hypergeometric inverted-beta priors. We derive expressions for posterior moments and marginal densities when these priors are used for a top-level normal variance in a Bayesian hierarchical model. We go on to prove a proposition that, together with the results for moments and marginals, allows us to characterize the frequentist risk of the Bayes estimators under all global-shrinkage priors in the class. These theoretical results, in turn, allow us to study the frequentist properties of the half-Cauchy prior versus a wide class of alternatives. The half-Cauchy occupies a sensible “middle ground” within this class: it performs very well near the origin, but does not lead to drastic compromises in other parts of the parameter space. This provides an alternative, classical justification for the repeated, routine use of this prior. We also consider situations where the underlying mean vector is sparse, where we argue that the usual conjugate choice of an inverse-gamma prior is particularly inappropriate, and can lead to highly distorted posterior inferences. Finally, we briefly summarize some open issues in the specification of default priors for scale terms in hierarchical models.
Vibrational relaxation in oxygen and nitrogen

A converging channel of area ratio 34 : 1 has been developed to produce strong shock waves in a tube. Shock waves of speeds M1=3−7·5 in oxygen and M1 = 5−10 in nitrogen have now been studied with an interferometer, and values of the relaxation time τ for the approach to vibrational equilibrium behind the shocks have been measured. The value of τ (atmospheric) varies from 54μsec at 800° K to 1·3 μsec at 3000° K for oxygen and from 19 μsec at 3500° K to 5 μsec at 5500° K for nitrogen. For oxygen, the graph of log τ against T−1/3 is not quite the straight line predicted by the Landau-Teller theory. The density ratios across the shocks were measured and compared with values calculated by the Bethe-Teller method for variable specific heats. Agreement between the measured and calculated values is satisfactory. Experiments were also performed on oxygen-nitrogen mixtures to determine the effect of nitrogen on the approach to equilibrium of the oxygen. It was found that O2 and N2 collisions at approximately 2000° K are 40% as effective in transferring energy to the oxygen as O2 and O2 collisions. A device that detects a shock with a time lag of less than 1μsec, consisting of an evaporated gold film which changes its resistance when heated by the shock, was also developed.
Development of a Gd Loaded Liquid Scintillator for Electron Anti-Neutrino Spectroscopy

We report on the development and deployment of 11.3 tons of 0.1% Gd-loaded liquid scintillator used in the Palo Verde reactor neutrino oscillation experiment. We discuss the chemical composition, properties, and stability of the scintillator elaborating on the details of the scintillator preparation crucial for obtaining a good scintillator quality and stability. ( 1999 Elsevier Science B.V. All rights reserved. PACS: 14.60.P; 29.40.M
Energy-latency tradeoff for in-network function computation in random networks

The problem of designing policies for in-network function computation with minimum energy consumption subject to a latency constraint is considered. The scaling behavior of the energy consumption under the latency constraint is analyzed for random networks, where the nodes are uniformly placed in growing regions and the number of nodes goes to infinity. The special case of sum function computation and its delivery to a designated root node is considered first. A policy which achieves order-optimal average energy consumption in random networks subject to the given latency constraint is proposed. The scaling behavior of the optimal energy consumption depends on the path-loss exponent of wireless transmissions and the dimension of the Euclidean region where the nodes are placed. The policy is then extended to computation of a general class of functions which decompose according to maximal cliques of a proximity graph such as the k-nearest neighbor graph or the geometric random graph. The modified policy achieves order-optimal energy consumption albeit for a limited range of latency constraints.
Combined Direct/Adjoint Reduced-Order Approximations for Design-Oriented Structural-Acoustics

The accuracy of modal-order reduction methods in structural dynamics and structural acoustics depends on the particular problem analyzed and particular modal bases selected. Modal-order reduction methods can become quite inaccurate when sensitivities of response functions with respect to design variables are required. Past research in linear aerodynamics and structural dynamics had shown how direct and adjoint solutions can be combined to yield reduced-order analysis and sensitivity approximations of the problems at hand with second-order accuracy. Efforts are reported to extend the methodology to structural acoustic problems of fluid-filled cavities enclosed by flexible walls. In this case, stress and pressure response to excitation has to be evaluated over a range of frequencies. Improved and more consistent accuracy is reported over a range of frequencies with the second-order method when accuracy of both approximate direct and approximate adjoint solutions is comparable. The second-order method cannot improve accuracy of first-order methods in general when one of the approximate first-order solutions is highly inaccurate.
Enrichment over iterated monoidal categories.

Joyal and Street note in their paper on braided monoidal cate- gories (9) that the 2-category V-Cat of categories enriched over a braided monoidal category V is not itself braided in any way that is based upon the braiding of V. The exception that they mention is the case in which V is symmetric, which leads to V-Cat being symmetric as well. The symmetry in V-Cat is based upon the symmetry of V. The motivation behind this paper is in part to describe how these facts relating V and V-Cat are in turn related to a categorical analogue of topological delooping. To do so I need to pass to a more general setting than braided and symmetric cat- egories — in fact the k-fold monoidal categories of Balteanu et al in (2). It seems that the analogy of loop spaces is a good guide for how to define the concept of enrichment over various types of monoidal objects, including k-fold monoidal categories and their higher dimensional counterparts. The main result is that for V a k-fold monoidal category, V-Cat becomes a (k − 1)-fold monoidal 2-category in a canonical way. In the next paper I indicate how this process may be iterated by enriching over V-Cat, along the way defining the 3-category of categories enriched over V-Cat. In fu- ture work I plan to make precise the n-dimensional case and to show how the group completion of the nerve of V is related to the loop space of the group completion of the nerve of V-Cat. AMS Classification 18D10; 18D20
Single photon source with individualized single photon certifications

As currently implemented, single-photon sources cannot be made to produce single photons with high probability, while simultaneously suppressing the probability of yielding two or more photons. Because of this, single photon sources cannot really produce single photons on demand. We describe a multiplexed system that allows the probabilities of producing one and more photons to be adjusted independently, enabling a much better approximation of a source of single photons on demand. The scheme uses a heralded photon source based on parametric downconversion, but by effectively breaking the trigger detector area into multiple regions, we are able to extract more information about a heralded photon than is possible with a conventional arrangement. This scheme allows photons to be produced along with a quantitative 'certification' that they are single photons. Some of the single-photon certifications can be significantly better than what is possible with conventional downconversion sources, as well as being better than faint laser sources. With such a source of more tightly certified single photons, it should be possible to improve the maximum secure bit rate possible over a quantum cryptographic link. We present an analysis of the relative merits of this method over the conventional arrangement.
High power femtosecond source near 1 micron based on an all-fiber Er-doped mode-locked laser

We report the design and performance of a high power femtosecond laser source near 1 micron wavelength which is generated from an octave-spanning supercontinuum (SC) pumped by an Er-doped mode-locked laser.
Group Laws and Free Subgroups in Topological Groups

A proof is given that a permutation group in which different finite sets have different stabilizers cannot satisfy any group law. For locally compact topological groups with this property, almost all finite subsets of the group are shown to generate free subgroups. Consequences of these theorems are derived for: Thompson's group , weakly branch groups, automorphism groups of regular trees, and profinite groups with alternating composition factors of unbounded degree.
An Optical Study of Stellar and Interstellar Environments of Seven Luminous and Ultraluminous X-Ray Sources

We have studied the stellar and interstellar environments of two luminous X-ray sources and five ultraluminous X-ray sources (ULXs) in order to gain insight into their nature. Archival Hubble Space Telescope images were used to identify the optical counterparts of the ULXs Ho IX X-1 and NGC 1313 X-2, and to make photometric measurements of the local stellar populations of these and the luminous source IC 10 X-1. We obtained high-dispersion spectroscopic observations of the nebulae around these seven sources to search for He II λ4686 emission and to estimate the expansion velocities and kinetic energies of these nebulae. Our observations did not detect nebular He II emission from any source, with the exception of LMC X-1; this is either because we missed the He III regions or because the nebulae are too diffuse to produce He II surface brightnesses that lie within our detection limit. We compare the observed ionization and kinematics of the supershells around the ULXs Ho IX X-1 and NGC 1313 X-2 with the energy feedback expected from the underlying stellar population to assess whether additional energy contributions from the ULXs are needed. In both cases, we find insufficient UV fluxes or mechanical energies from the stellar population; thus these ULXs may be partially responsible for the ionization and energetics of their supershells. All seven sources that we studied are in young stellar environments, and six of them have optical counterparts with masses 7 M☉; thus, these sources are most likely high-mass X-ray binaries.
Formation of Martian flood features by release of water from confined aquifers

It is proposed that the rapid release of water under great pressure from deeply buried aquifers is responsible for the formation of the Martian channels suggestive of catastrophic flooding (outflow channels). Fine channels in the Martian surface suggest the presence of surface water early in the history of the planet, which would have entered the ground water system through the porous near-surface rocks. Subsequent global cooling would have trapped the ground water under a thick permafrost layer and formed a system of confined aquifers. High pore pressures within the aquifers are considered to have triggered the breakout of water from the aquifers at rates of from 10 to the 5th to 10 to the 7th cu m/sec, which would be prevented from reentering the ground water system by the layer of permafrost. Outflow from the aquifer is also considered to have caused the undermining of adjacent areas and the collapse of the surface to form areas of chaos, often associated with channels.
Extractors for Low-Weight Affine Sources

We give polynomial time computable extractors for \emph{low-weight affince sources}. A distribution is affine if it samples a random points from some unknown low dimensional subspace of $\mathbb{F}_2^n$. A distribution is low weight affine if the corresponding linear space has a basis of low-weight vectors. Low-weight affine sources are thus a generalization of the well studied models of bit-fixing sources (which are just weight $1$ affine sources). For universal constants $c,\epsilon$, our extractors can extract almost all the entropy from weight $k^{\epsilon}$ affine sources of dimension $k$, as long as $k ≫ \log ^c n$, with error $2^{-k^{\Omega(1)}}$. In particular, our results give new extractors for low entropy bit-fixing sources, with exponentially small error, a parameter that is important for the application of these extractors to cryptography. Our techniques involve constructing new \emph{condensers} for \emph{affine somewhere random sources}.
Precision crystal calorimeters in high-energy physics: past, present, and future

Precision crystal calorimeters traditionally play an important role in high energy physics experiments. In the last two decades, it faces a challenge to maintain its precision in a hostile radiation environment. This paper reviews the performance of crystal calorimeters constructed for high energy physics experiments and the progress achieved in understanding crystal's radiation damage as well as in developing high quality scintillating crystals for particle physics. Potential applications of new generation scintillating crystals of high density and high light yield, such as LSO and LYSO, in particle physics experiments is also discussed.
Josephson effect in thin films: The role of vortex excitations

We consider quantum slips of phase at a round hole punctured in a thin superconducting film and show that virtual vortex pairs provide an efficient pathway for these processes. Specifically, in the limit when the normalstate resistivity of the film is large, the presence of the film causes at most a logarithmic interaction between phase slips. This is in contrast to the nearly linear confining interaction (and the consequent nearly activated behavior of the resistance) obtained when vortices are neglected.
Electrochromic blueshift in polymer-dispersed liquid-crystal cells

Electrochromic blueshift in the absorption band of polymer-dispersed liquid-crystal cells is reported as a function of applied electric field. The changes in the peak absorption wavelength, absorption broadening, and their possible relationships with the nonlinear optical properties of polymer-dispersed liquid-crystal cells are discussed.
Navier-Stokes Simulations of Rotor/Stator Interaction Using Patched and Overlaid Grids

An accurate numerical analysis of the flows associated with rotor/stator configurations in turbomachinery can be very helpful in optimizing performance. In this study, the unsteady, thin-layer, Navier-Stokes equations are solved using a system of patched and overlaid grids for a rotor/stator configuration of an axial turbine. The equations necessary for an accurate transfer of information between the several grids are briefly described within the framework of an iterative, implicit algorithm. Results in the form of Mach number contours, time-averaged pressures, unsteady pressures, amplitudes, and phase are presented. The numerical results are also compared with experimental data and the agreement is found to be good. HE aerodynamic processes associated with the flow of fluid through turbomachines pose one of the toughest challenges to the computational fluid dynamicist. The un- steady nature of the flow, the complex geometries involved, the motion of some parts of the system relative to others, and the periodic transition of the flow from laminar to tur- bulent are some of the factors that contribute to the com- plexity of the problem. A clear understanding of these types of flows is essential for the optimization of the performance of turbomachiner y. In this study, an attempt is made to analyze two-dimensional flow past the rotor/stator con- figuration of an axial turbine using state-of-the-art computa- tional tools and computing facilities. The two-dimensional analysis of stator airfoils in isolation or rotor airfoils in isolation is a relatively straightforward task. Such an analysis is valid when the two rows of blades are set far enough apart so that the interaction effects are minimal. However, the desire to minimize engine length re- quires the stator and rotor airfoils to be closely spaced. Clearly, the interaction effects will become more important as the axial gap between the rows is reduced. In fact, the flow becomes periodically unsteady for small values of the axial gap. The experimental results of Ref. 1 show that the temporal pressure fluctuation (the difference between the minimum and maximum pressure values) near the leading edge of the rotor can be as much as 12% of the exit dynamic pressure when the axial gap is reduced to 15% of the chord length (for the operating conditions and geometry chosen). Hence, it is important that the rotor and stator airfoils be treated as a single system when the interaction effects become predominant. A computational tool that provides the design engineer with the necessary aerodynamic data can be used to great advantage in redesigning rotor and stator airfoils to enhance performance. Such a tool has to accurately simulate the unsteady flow associated with rotor/stator con- figurations exhibiting a strong interaction. A finite-differe nce solution to the Navier-Stokes equations requires the generation of a computational grid for the
Performance degradation of DOA estimators due to unknown noise fields

A statistical performance analysis of subspace-based directions-of-arrival (DOA) estimation algorithms in the presence of correlated observation noise with unknown covariance is presented. The analysis of five different estimation algorithms is unified by a single expression for the mean-squared DOA estimation error which is derived using a subspace perturbation expansion. The analysis assumes that only a finite amount of array data is available. >
Fast set intersection in memory

Set intersection is a fundamental operation in information retrieval and database systems. This paper introduces linear space data structures to represent sets such that their intersection can be computed in a worst-case efficient way. In general, given k (preprocessed) sets, with totally n elements, we will show how to compute their intersection in expected time [EQUATION], where r is the intersection size and w is the number of bits in a machine-word. In addition, we introduce a very simple version of this algorithm that has weaker asymptotic guarantees but performs even better in practice; both algorithms outperform the state of the art techniques for both synthetic and real data sets and workloads.
Perfect IFG-Formulas

IFG logic is a variant of the independence-friendly logic of Hintikka and Sandu. We answer the question: “Which IFG-formulas are equivalent to ordinary first-order formulas?” We use the answer to prove the ordinary cylindric set algebra over a structure can be embedded into a reduct of the IFG-cylindric set algebra over the structure.
Numerical study of the formation, ion spin-up and nonlinear stability properties of field-reversed configurations

Results of three-dimensional (3D) numerical simulations of field-reversed configurations (FRCs) are presented. The emphasis of this work is on the nonlinear evolution of magnetohydrodynamic (MHD) instabilities in kinetic FRCs and the new FRC formation method by counter-helicity spheromak merging. Kinetic simulations show nonlinear saturation of the n = 1 tilt mode, where n is the toroidal mode number. The n = 2 and n = 3 rotational modes are observed to grow during the nonlinear phase of the tilt instability due to the ion spin-up in the toroidal direction. The ion toroidal spin-up is shown to be related to the resistive decay of the internal flux and the resulting loss of particle confinement. Three-dimensional MHD simulations of counter-helicity spheromak merging and FRC formation show good qualitative agreement with the results from the SSX–FRC experiment. The simulations show the formation of an FRC in about 20–30 Alfven times for typical experimental parameters. The growth rate of the n = 1 tilt mode is shown to be significantly reduced compared with the MHD growth rate due to the large plasma viscosity and field-line-tying effects.
Landau theory of tilting of oxygen octahedra in perovskites

The list of possible commensurate phases obtained from the parent tetragonal phase of Ruddlesden-Popper (RP) systems, ${A}_{n+1}{B}_{n}{C}_{3n+1}$ for general $n$ due to a single phase transition involving the reorienting of octahedra of $C$ (oxygen) ions is reexamined using a Landau expansion. This expansion allows for the nonlinearity of the octahedral rotations and the rotation-strain coupling. It is found that most structures allowed by symmetry are inconsistent with the constraint of rigid octahedra, which dictates the form of the quartic terms in the Landau free energy. For ${A}_{2}B{C}_{4}$ our analysis allows only 10 of the 41 structures which satisfy the general symmetry arguments of Hatch et al. [Phys. Rev. B 39, 9282 (1989)]. The symmetry of rotations for RP systems with $ng2$ is clarified. Our list of possible structures for general $n$ excludes many structures allowed in previous studies.
Tax Progressivity and Income Inequality

1. Introduction Joel Slemrod 2. Trends in Federal tax progressivity, 1980-93 Richard Kasten, Frank Sammartino and Eric Toder Comments William G. Gale 3. The lifetime incidence of state and local taxes: measuring changes during the 1980s Gilbert Metcalf Comments Robert P. Inman 4. Trends in income inequality: the impact of, and implications for, tax policy Lynn A. Karoly Comments David M. Cutler 5. The efficiency cost of increased progressivity Robert K. Triest Comments Gary Burtless 6. On the high-income Laffer curve Joel Slemrod Comments C. Eugene Steuerle 7. Tax progressivity and household portfolios: descriptive evidence from the surveys of consumer finances John Karl Scholz Comments Roger H. Gordon 8. Progressivity of capital gains taxation with optimal portfolio selection Michael Haliassos and Andrew B. Lyon Comments James M. Poterba 9. Perceptions of fairness in the crucible of tax policy Steven M. Sheffrin Comments Jane G. Gravelle 10. Progressive taxation, equity and tax design Richard A. Musgrave Index.
Test generation for multiple state-table faults in finite-state machines

A test generation procedure to detect multiple state-table faults in finite-state machines is proposed. The importance of multiple state-table faults and their advantages as test generation objectives to avoid the need for checking experiments are considered. The proposed procedure is based on a new method for implicit enumeration of large numbers of multiple faults by using incompletely specified faulty machines. Experimental results are presented to demonstrate the effectiveness of implicit fault enumeration in detecting large numbers of multiple faults and in guaranteeing detection of all the faults or all the faults up to a specific multiplicity.
Distribution of Human Response Times

We confirm that distributions of human response times have power-law tails and argue that, among closed-form distributions, the generalized inverse gamma distribution is the most plausible choice for their description. We speculate that the task difficulty tracks the half-width of the distribution and show that it is related to the exponent of the power-law tail. V C 2015 Wiley Periodicals, Inc. Complexity 000: 00–00, 2015
Explaining production inefficiency in China's agriculture using data envelopment analysis and semi-parametric bootstrapping

Abstract In this paper we examine more closely the factors associated with production inefficiency in China's agriculture. The approach we take involves a two-stage process where output efficiency scores are first estimated using data envelopment analysis, and then in the second stage, variation in the resulting efficiency scores is explained using a truncated regression model with inference based on a semi-parametric bootstrap routine. Among the results we find that a heavy industrial presence is associated with reduced agricultural production efficiency and may be an indication that externalities from the industrial process, such as air and ground water pollution, affect agricultural production. We also find evidence that counties with a large percentage of the rural labor force engaged in agriculture tend to be less efficient, and suggests that nurturing and promoting growth of non-primary agriculture may lead to more efficient use of labor resources in agriculture.
Food Access and Perceptions of the Community and Household Food Environment as Correlates of Fruit and Vegetable Intake among Rural Seniors

Although the importance of fruit and vegetable consumption to health has been well established, few studies have focused on access to fruits and vegetables in rural areas; even fewer examined the relationship between food access and fruit and vegetable consumption among seniors. To examine the spatial challenges to good nutrition faced by seniors who reside in rural areas and how spatial access influences fruit and vegetable intake. A cross-sectional analysis using data from the 2006 Brazos Valley Health Assessment (mailsurvey) for 582 rural seniors (60-90 years), who were recruited by random digit dialing; food store data from the 2006-2007 Brazos Valley Food Environment Project that used ground-truthed methods to identify, geocode, and inventory fruit and vegetables in all food stores. Few of the BVHA seniors consumed the recommended intakes of fruits or vegetables; women consumed more servings of fruit (1.49 ± 0.05 vs. 1.29 ± 0.07, p = 0.02), similar servings of vegetables (2.18 ± 0.04 vs. 2.09 ± 0.07, p = 0.28), and more combined fruit and vegetables (3.67 ± 0.08 vs. 3.38 ± 0.12, p = 0.04) than men. The median distances to fresh fruit and vegetables were 5.5 miles and 6.4 miles, respectively. When canned and frozen fruit and vegetables were included in the measurement of overall fruit or vegetables, the median distance for a good selection of fruit or vegetables decreased to 3.4 miles for overall fruit and 3.2 miles for overall vegetables. Almost 14% reported that food supplies did not last and there was not enough money to buy more. Our analyses revealed that objective and perceived measures of food store access - increased distance to the nearest supermarket, food store with a good variety of fresh and processed fruit, or food store with a good variety of fresh and processed vegetables - were associated with decreased daily consumption of fruit, vegetables, and combined fruit and vegetables, after controlling for the influence of individual characteristics and perceptions of community and home food resources. Findings suggest that interventions designed to increase fruit and vegetable consumption among rural seniors should consider strategies to ameliorate differential access to healthy food due to food store distance.
Monitoring of Sound and Carious Surfaces under Sealants over 44 Months

Although there is strong evidence for the effectiveness of sealants, one major barrier in sealant utilization is the concern of sealing over active caries lesions. This study evaluated detection and monitoring of caries lesions through a clear sealant over 44 mo. Sixty-four 7- to 10-year-old children with at least 2 permanent molars with International Caries Detection and Assessment System (ICDAS) scores 0-4 (and caries less than halfway through the dentin, radiographically) were examined with ICDAS, DIAGNOdent, and quantitative light-induced fluorescence (QLF) before sealant placement and 1, 12, 24, and 44 mo (except QLF) after. Bitewing radiographs were taken yearly. DIAGNOdent and QLF were able to distinguish between baseline ICDAS before and after sealant placement. There was no significant evidence of ICDAS progression at 12 mo, but there was small evidence of minor increases at 24 and 44 mo (14% and 14%, respectively) with only 2% ICDAS ≥ 5. Additionally, there was little evidence of radiographic progression (at 12 mo = 1%, 24 mo = 3%, and 44 mo = 9%). Sealant retention rates were excellent at 12 mo = 89%, 24 mo = 78%, and 44 mo = 70%. The small risk of sealant repair increased significantly as baseline ICDAS, DIAGNOdent, and QLF values increased. However, regardless of lesion severity, sealants were 100% effective at 12 mo and 98% effective over 44 mo in managing occlusal surfaces at ICDAS 0-4 (i.e., only 4 of 228 teeth progressed to ICDAS ≥ 5 associated with sealants in need of repair and none to halfway or more through the dentin, radiographically). This study suggests that occlusal surfaces without frank cavitation (ICDAS 0-4) that are sealed with a clear sealant can be monitored with ICDAS, QLF, or DIAGNOdent, which may aid in predicting the need for sealant repair.
The impact of business environment and economic geography on plant- level productivity: an analysis of Indian industry *

Our analysis of manufacturing plants sampled from India’s major industrial centers shows large produc tivity gaps across cities. The gaps partly reflect differences in agglomeration economies and in market access. However, they are also explained to a greater extent by differences in the degree of labor regulation and in the severity of power shortages. This is indication that governments can help narrow regional disparities in industrial growth by fostering the “right business environment” in locations where industry might otherwise be held back by powerful forces of economic geography. There is indeed a pattern in the data whereby geographically disadvantaged cities seem to compensate partially for their natural disadvantage by having a better business environment than more geographically advantaged locations.
A relatively short cylindrical broadband antenna with tapered resistive loading for picosecond pulse measurements

A relatively short cylindrical antenna with continuously tapered resistive loading has been studied for the purpose of picosecond pulse measurements. The antenna considered is a nonconducting cylinder with continuously deposited varying-conductivity resistive loading. The current distributions on the antenna were numerically calculated using the method of moments. Using these current distributions, other quantities such as input admittance, near-field and farfield radiation patterns, and radiation efficiency, were also numerically calculated and compared with the results using the Wu-King's approximate current distribution. Agreement is relatively good except at high frequencies kh > \pi/2 where the method of moments appears to give better results. To verify the theoretical results, several resistively loaded antennas were fabricated, and their picosecond pulse receiving characteristics were analyzed for the frequency range between 5 kHz and 5 GHz. The experimental results indicate excellent linear amplitude and phase response over the frequency range. This provides the unique capability of this antenna to measure fast time-varying electromagnetic fields with minimal pulse-shape distortion due to nonlinear amplitude or phase characteristics.