cssi/SciSciGPT-SciSciNet huggingface dataset:
CLEO contributions to tau physics

Abstract We review many of the contributions of the CLEO experiment to tau physics. Topics discussed are: branching fractions for major decay modes and tests of lepton universality; rare decays; forbidden decays; Michel parameters and spin physics; hadronic sub-structure and resonance parameters; the tau mass, tau lifetime, and tau neutrino mass; searches for CP violation in tau decay; tau pair production, dipole moments, and CP violating EDM; and tau physics at CLEO-III and at OLEO-c.
Low NOx combustion for liquid fuels: Atmospheric pressure experiments using a staged prevaporizer-premixer

Low emissions of NO x are obtained for a wide range of liquid fuels by using a staged prevaporizing-premixing injector. The injector relies on two stages of air temperature and fires into a laboratory jet-stirred reactor operated at atmospheric pressure and nominal Φ of 0.6. The liquid fuels burned are methanol, normal alkanes from pentane to hexadecane, benzene, toluene, two grades of light naphtha, and four grades of No. 2 diesel fuel. Additionally, natural gas, ethane, and industrial propane are burned. For experiments conducted for 1790 K combustion temperature and 2.3±0.1 ms combustion residence time, the NO x (adjusted to 15% O 2 dry) varies from a low of 3.5 ppmv for methanol to a high of 11.5 ppmv for No. 2 diesel fuel. For the most part, the NO x and CO are positively correlated with the fuel carbon to hydrogen ratio (C/H). Chemical kinetic modeling suggests the increase in NO x with C/H ratio is caused in significant part by the increasing superequilibrium concentrations of O-atom created by the increasing levels of CO burning in the jet-stirred reactor. Fuel bound nitrogen also contributes NO x for the burning of the diesel fuel. This paper describes the staged prevaporizing-premixing injector, the examination of the injector, and the NO x and CO measurements and their interpretation. Optical measurements, using beams of He-Ne laser radiation passed across the outlet stream of the injector indicate complete vaporization and a small variation in the cross-stream averaged fuel/air ratio. The latter is determined by measuring the standard deviation and mean of the transmission of the laser beam passed through the stream. Additional measurements and inspections indicate no pressure oscillations within the injector and no gum and carbon deposition. Thus, the NO x and CO measurements are obtained for fully vaporized, well premixed conditions devoid of preflame reactions within the injector.
The Volume and Composition of Trade Between Rich and Poor Countries

North-South trade is studied in a model of vertical product differentiation. The South produces a low-quality spectrum of goods and the North a high-quality spectrum. An increase in the South's population lowers its relative wage, expands the spectrum of Southern goods at the top, and shifts the Northern spectrum upward. An increase in Northern labour productivity raises its relative wage. If the increase is neutral or export-biased, then the South's terms of trade improve, the spectrum of Northern products expands, the spectrum of Southern products contracts, and the volume of trade grows. If it is biased against Northern exports, these effects are reversed. Similar results hold for neutral increases in Southern productivity. New goods are typically developed, first produced, and first consumed in the most advanced countries, and only later produced and consumed in less advanced countries. A number of explanations have been suggested for this pattern, the product cycle. In his classic article, Vernon (1966) stressed that the demand for certain types of consumer goods, especially labour-saving goods, is greatest in high-income countries, and that familiarity with the tastes of potential buyers is a critical factor in successful product innovation. In his view, proximity to the product market is the key factor. More recently, Krugman (1979), Dollar (1986), Jensen and Thursby (1986, 1987), and Grossman and Helpman (1989) have put forward an explanation based on a techno- logical advantage in the advanced countries in carrying out R&D. They assume that innovation can take place only in the more advanced region, hereafter called the North, and that reverse engineering is required in the less-developed region, the South, before a new good can be produced there. Preferences over product varieties are taken to be homothetic and symmetric, so the model is one of horizontal product differentiation. North-South trade is motivated by a preference for diversity, and growth is represented by an increase in the total number of varieties available. This model captures many interesting aspects of the development and diffusion of new products, but it also has some unsatisfactory features. First, consumption patterns are the same in both regions. Because preferences are homothetic, Northerners simply consume proportionately more (per capita) of each variety. This is clearly at odds with the fact, stressed by Vernon, that new goods are not typically consumed in the South until later in the cycle. Second, old goods are never dropped from production. Because
Anomalies and graded coisotropic branes

We compute the anomaly of the axial U(1) current in the A-model on a Calabi-Yau manifold, in the presence of coisotropic branes discovered by Kapustin and Orlov. Our results relate the anomaly-free condition to a recently proposed definition of graded coisotropic branes in Calabi-Yau manifolds. More specifically, we find that a coisotropic brane is anomaly-free if and only if it is gradable. We also comment on a different grading for coisotropic submanifolds introduced recently by Oh.
A survey of maneuvering target tracking-part VIa: density-based exact nonlinear filtering

This paper is Part VIa of a comprehensive survey of maneuvering target tracking without addressing the so-called measurement-origin uncertainty. It covers theoretical results of density-based exact nonlinear filtering for handling the uncertainties induced by potential target maneuvers as well as nonlinearities in the dynamical systems commonly encountered in target tracking. An emphasis is given to the results of significance for practical considerations, especially those of good potential for tracking applications.
Correction for the influence of velocity lenses on nonhyperbolic moveout inversion for VTI media

Nonhyperbolic moveout analysis plays an increasingly important role in velocity model building because it provides valuable information for anisotropic parameter estimation. However, lateral heterogeneity associated with stratigraphic lenses such as channels and reefs can significantly distort the moveout parameters, even when the structure is relatively simple. We analyze the influence of a low-velocity isotropic lens on nonhyperbolic moveout inversion for horizontally layered VTI (transversely isotropic with a vertical symmetry axis) models. Synthetic tests demonstrate that a lens can cause substantial, laterally varying errors in the normal-moveout velocity ( Vnmo ) and the anellipticity parameter η . The area influenced by the lens can be identified using the residual moveout after the nonhyperbolic moveout correction as well as the dependence of errors in Vnmo and η on spreadlength. To remove such errors in Vnmo and η , we propose a correction algorithm designed for a lens embedded in a horizontally ...
Advances in the use of synthetic combinatorial chemistry: Mixture-based libraries

The conceptual and technical approaches that led to the explosive growth of combinatorial chemistry began approximately 20 years ago. In the past decade, combinatorial chemistry has continued to expand with new chemistries, technological improvements and, most importantly, a clear demonstration of its utility in the identification of active compounds for research and drug-discovery programs. This article describes the conceptual and practical breakthroughs that have been critical for the development of synthetic combinatorial methods and includes the most recent developments and applications of mixture-based combinatorial libraries.
Message-Passing Algorithms and Improved LP Decoding

Linear programming (LP) decoding for low-density parity-check codes (and related domains such as compressed sensing) has received increased attention over recent years because of its practical performance-coming close to that of iterative decoding algorithms-and its amenability to finite-blocklength analysis. Several works starting with the work of Feldman showed how to analyze LP decoding using properties of expander graphs. This line of analysis works for only low error rates, about a couple of orders of magnitude lower than the empirically observed performance. It is possible to do better for the case of random noise, as shown by Daskalakis and Koetter and Vontobel. Building on work of Koetter and Vontobel, we obtain a novel understanding of LP decoding, which allows us to establish a 0.05 fraction of correctable errors for rate-½ codes; this comes very close to the performance of iterative decoders and is significantly higher than the best previously noted correctable bit error rate for LP decoding. Our analysis exploits an explicit connection between LP decoding and message-passing algorithms and, unlike other techniques, directly works with the primal linear program. An interesting byproduct of our method is a notion of a “locally optimal” solution that we show to always be globally optimal (i.e., it is the nearest codeword). Such a solution can in fact be found in near-linear time by a “reweighted” version of the min-sum algorithm, obviating the need for LP. Our analysis implies, in particular, that this reweighted version of the min-sum decoder corrects up to a 0.05 fraction of errors.
Combustor Concepts for Aircraft Gas Turbine Low-Power Emissions Reduction

Several combustor concepts were designed and tested to demonstrate significant reductions in aircraft engine idle pollutant emissions. Each concept used a different approach for pollutant reductions: the hot wall combustor employs a thermal barrier coating and impingement cooled liners; the recuperative cooling combustor preheats the air before entering the combustion chamber; and the catalytic converter combustor is composed of a conventional primary zone followed by a catalytic bed for pollutant cleanup. The designs are discussed in detail and test results are presented for a range of aircraft engine idle conditions. The results indicate that ultralow levels of unburned hydrocarbons and carbon monoxide emissions can be achieved.
Catalytic α-Allylation of Unprotected Amino Acid Esters

Catalytic α-allylation of unprotected amino acid esters to produce α-quaternary α-allyl amino acid esters is reported. Catalytic loadings of picolinaldehyde and Ni(II) salts induce preferential reactivity at the enolizable α-carbon of amino acid esters over the free nitrogen with electrophilic palladium π-allyl complexes. Fourteen examples are given. Additionally, the use of chiral ligands to access enantioenriched α-quaternary amino acid esters from racemic precursors is demonstrated by the enantioselective synthesis of α-allyl phenylalanine methyl ester from racemic phenylalanine methyl ester.
Plasma Spraying of Porous Electrodes for a Planar Solid Oxide Fuel Cell

This paper reports on porous electrodes of Sr-doped lanthanum manganite in a planar solid oxide fuel cell made by the plasma spray technique. Spherical carbon particles were utilized as an effective pore former. Spraying a mixture of annealed oxide powders sized between 50 to 200 {mu}m and 15 wt% solid Carbospheres resulted in a uniform coating of 40% porosity. Porous coatings were also obtained when rigid resin intermediates were sprayed followed by annealing at 1000{degrees}C in air.
A smoothing stochastic gradient method for composite optimization

We consider the unconstrained optimization problem whose objective function is composed of a smooth and a non-smooth components where the smooth component is the expectation of a random function. This type of problem arises in some interesting applications in machine learning. We propose a stochastic gradient descent algorithm for this class of optimization problems. When the non-smooth component has a particular structure, we propose a stochastic gradient descent algorithm by incorporating a smoothing method into our first algorithm. The proofs of the convergence rates of these two algorithms are given and we show the numerical performance of our algorithm by applying them to regularized linear regression and logistic regression problems with different sets of synthetic data.
A Stereocontrolled Synthesis of (±)-Xenovenine via a Scandium(III)-Catalyzed Internal Aminodiene Bicyclization Terminated by a 2-(5-Ethyl-2-thienyl)ethenyl Group

A highly diastereoselective binary hydroamination of a 5-amino-1,8-diene containing a 2-(5-ethyl-2-thienyl)ethenyl terminator has been utilized in an efficient synthesis of (±)-xenovenine (1). A pronounced rate enhancement was observed for cyclization onto the 2-(heteroaromatic)ethenyl group in comparison to a simple 1,2-disubstituted alkene.
Controlling adsorbate vibrational lifetimes using superlattices

We propose using short-period superlattices as substrates to control the vibrational relaxation dynamics of adsorbate overlayers. The mass modulation of superlattices creates both band gaps and large spectral enhancements in the phonon density of states. These modifications can dramatically alter the coupling between vibrational modes of the adsorbate overlayer and the substrate lattice, thereby significantly affecting the lifetime of adsorbate modes.
Two new tidally distorted white dwarfs

We identify two new tidally distorted white dwarfs (WDs), SDSS J174140.49+652638.7 and J211921.96–001825.8 (hereafter J1741 and J2119). Both stars are extremely low mass (ELM, ≤ 0.2 M ☉) WDs in short-period, detached binary systems. High-speed photometric observations obtained at the McDonald Observatory reveal ellipsoidal variations and Doppler beaming in both systems; J1741, with a minimum companion mass of 1.1 M ☉, has one of the strongest Doppler beaming signals ever observed in a binary system (0.59% ± 0.06% amplitude). We use the observed ellipsoidal variations to constrain the radius of each WD. For J1741, the star's radius must exceed 0.074 R ☉. For J2119, the radius exceeds 0.10 R ☉. These indirect radius measurements are comparable to the radius measurements for the bloated WD companions to A-stars found by the Kepler spacecraft, and they constitute some of the largest radii inferred for any WD. Surprisingly, J1741 also appears to show a 0.23% ± 0.06% reflection effect, and we discuss possible sources for this excess heating. Both J1741 and J2119 are strong gravitational wave sources, and the time-of-minimum of the ellipsoidal variations can be used to detect the orbital period decay. This may be possible on a timescale of a decade or less.
Screening for brain aneurysm in the Familial Intracranial Aneurysm study: frequency and predictors of lesion detection

Object Approximately 20% of patients with an intracranial saccular aneurysm report a family history of intracranial aneurysm (IA) or subarachnoid hemorrhage. A better understanding of predictors of aneurysm detection in familial IA may allow more targeted aneurysm screening strategies. Methods The Familial Intracranial Aneurysm (FIA) study is a multicenter study, in which the primary objective is to define the susceptibility genes related to the formation of IA. First-degree relatives (FDRs) of those affected with IA are offered screening with magnetic resonance (MR) angiography if they were previously unaffected, are ≥ 30 years of age, and have a history of smoking and/or hypertension. Independent predictors of aneurysm detection on MR angiography were determined using the generalized estimating equation version of logistic regression. Results Among the first 303 patients screened with MR angiography, 58 (19.1%) had at least 1 IA, including 24% of women and 11.7% of men. Ten (17.2%) of 58 affected patien...
A simulated comparison of the useful energy gain in a fixed and a fully tracking flat plate collector

ABSTRACT A comparison is made in the useful energy gain of a flat plate collector facing due south and one that is fully tracking using actual hourly meterological data applied to a “theoretical” flat plate collector. The ratio of total hourly radiation on a tilted surface to that on a horizontal surface, R, is found for a tracking collector using Rb, the ratio of hourly beam radiation on a tilted surface to that on a horizontal surface, and a knowledge of the ratio of daily diffuse radiation to daily total radiation on a horizontal surface. A digital computer is used to calculate the daily useful energy gain using hourly values of solar radiation on a tilted surface, ambient temperature and wind velocity. The results show that the fully tracking flat plate collector outperforms the fixed flat plate collector by a wide enough margin to warrent further investigation.
An optical-fiber-based probe for photonic crystal microcavities

We review a novel method for characterizing both the spectral and spatial properties of resonant cavities within two- dimensional photonic crystals (PCs). An optical fiber taper serves as an external waveguide probe whose micron-scale field is used to source and couple light from the cavity modes, which appear as resonant features in the taper's wavelength-dependent transmission spectrum when it is placed within the cavity's near field. Studying the linewidth and depth of these resonances as a function of the taper's position with respect to the resonator produces quantitative measurements of the quality factor (Q) and modal volume (V/sub eff/) of the resonant cavity modes. Polarization information about the cavity modes can be obtained by studying their depths of coupling when the cavity is probed along different axes by the taper. This fiber-based technique has been used to measure Q/spl sim/40,000 and V/sub eff//spl sim/0.9 cubic wavelengths in a graded square lattice PC microcavity fabricated in silicon. The speed and versatility of this fiber-based probe is highlighted, and a discussion of its applicability to other wavelength-scale resonant elements is given.
Initial selection and screening of the CFA candidate computer architectures

The initial selection criteria that were developed and used by the Army/Navy Computer Family Architecture (CFA) committee in their evaluation of alternative computer architectures is presented in this article. These initial criteria were used in this first phase of the CFA evaluation process to reduce the number of computer architectures from the original set of nine to the most promising three or four architectures for the more intensive evaluation discussed in the companion articles. The machines selected by this Initial ranking and screening process for further evaluation were the Interdata 8/32, DEC PDP-11, and the IBM S/370.
Valuing an Entrepreneurial Enterprise

This article focuses on valuation issues and methods that are related to a closely held entrepreneurial enterprise. This focus is motivated by the fact that the number of small, closely held business start-ups, which we refer to broadly by the term “entrepreneurial enterprises,” continues to grow year on year, and new business ventures remain the primary source for employment growth in the USA and most industrialized nations. Also, the topic of valuation of entrepreneurial enterprises has for the most part been ignored. The traditional approaches to valuation of small, closely held entrepreneurial enterprises are, in our view, wanting in a number of important respects. Simply, traditional valuation methods are modeled in a manner that is applicable to a going-concern business with a history of sales and revenues. That is not the case for an entrepreneurial enterprise as we define it, and thus use of traditional valuation methods is questionable.
Agricultural and forestry wastes as an energy resource

Abstract The feasibility of converting agricultural and forestry residues to energy is evaluated based on a county-by-county inventory for the contiguous United States. The impact of this energy resource on the U.S. energy system is forecast using the SRI energy model.
Perturbative subtraction methods

Abstract The effects of an automated, tenth order in κ subtraction scheme on the noise variance of various Wilson QCD disconnected matrix elements are examined. It is found that there is a dramatic reduction in the variance of the lattice point-split electromagnetic currents and that this reduction persists at small quark mass.
The Impact of Central Bank Independence on Political Monetary Cycles in Advanced and Developing Nations

This paper examines the extent to which monetary policy is manipulated for political purposes during elections. We do not detect political monetary cycles in advanced countries or developing nations with independent central banks. We do find evidence, however, in developing countries that lack central bank independence. Furthermore, we find some evidence that these cycles are not caused by monetization of election-related fiscal expansions. This suggests that pressure by politicians on the central bank to exploit the Phillips curve may be an important factor in generating political monetary cycles.
Stress Tensor Correlators in the Schwinger-Keldysh Formalism

We express stress tensor correlators using the Schwinger–Keldysh formalism. The absence of off-diagonal counterterms in this formalism ensures that the +− and −+ correlators are free of primitive divergences. We use dimensional regularization in position space to explicitly check this at one loop order for a massless scalar on a flat space background. We use the same procedure to show that the ++ correlator contains the divergences first computed by 't Hooft and Veltman for the scalar contribution to the graviton self-energy.
Vehicular storage of hydrogen in insulated pressure vessels

Abstract This paper describes an alternative technology for storing hydrogen fuel onboard vehicles. Insulated pressure vessels are cryogenic capable vessels that can accept cryogenic liquid hydrogen, cryogenic compressed gas or compressed hydrogen gas at ambient temperature. Insulated pressure vessels offer advantages over conventional storage approaches. Insulated pressure vessels are more compact and require less carbon fiber than compressed hydrogen vessels. They have lower evaporative losses than liquid hydrogen tanks, and are lighter than metal hydrides. The paper outlines the advantages of insulated pressure vessels and describes the experimental and analytical work conducted to verify that insulated pressure vessels can be safely used for vehicular hydrogen storage. Insulated pressure vessels have successfully completed a series of certification tests. A series of tests have been selected as a starting point toward developing a certification procedure. An insulated pressure vessel has been installed in a hydrogen fueled truck and tested over a six month period.
From completely positive maps to the quantum Markovian semigroup master equation

Abstract A central problem in the theory of the dynamics of open quantum systems is the derivation of a rigorous and computationally tractable master equation for the reduced system density matrix. Most generally, the evolution of an open quantum system is described by a completely positive linear map. We show how to derive a completely positive Markovian master equation (the Lindblad equation) from such a map by a coarse-graining procedure. We provide a novel and explicit recipe for calculating the coefficients of the master equation, using perturbation theory in the weak-coupling limit. The only parameter external to our theory is the coarse-graining time-scale. We illustrate the method by explicitly deriving the master equation for the spin-boson model. The results are evaluated for the exactly solvable case of pure dephasing, and an excellent agreement is found within the time-scale where the Markovian approximation is expected to be valid. The method can be extended in principle to include non-Markovian effects.
Time Evolution of Galaxy Formation and Bias in Cosmological Simulations

The clustering of galaxies relative to the underlying mass distribution declines with cosmic time for three reasons. First, nonlinear peaks become less rare events as the density field evolves. Second, the densest regions stop forming new galaxies because their gas becomes too hot to cool and collapse. Third, after galaxies form, they are subject to the same gravitational forces as the dark matter, and thus they tend to trace the dark matter distribution more closely with time; in this sense, they are gravitationally "debiased." In order to illustrate these effects, we perform a large-scale hydrodynamic cosmological simulation of a Λ cold dark matter (ΛCDM) model with Ω0 = 0.37 and examine the statistics of δ*(,z), the density field of recently formed galaxies at position and redshift z. We find that the bias of recently formed galaxies b* ≡ δ1/2/δ21/2, where δ is the mass overdensity, evolves from b* ~ 4.5 at z = 3 to b* ~ 1 at z = 0, on 8 h-1 Mpc comoving scales. The correlation coefficient r* ≡ δδ*/δ21/2δ1/2 evolves from r* ~ 0.9 at z = 3 to r* ~ 0.3 at z = 0. That is, as gas in the universe heats up and prevents star formation, the star-forming galaxies become poorer tracers of the mass density field. We show that the linear continuity equation is a good approximation for describing the gravitational debiasing, even on nonlinear scales. The most interesting observational consequence of the simulations is that the linear regression of the galaxy formation density field on the galaxy density field, b*gr*g = δ*δg/δ, evolves from about 0.9 at z = 1 to 0.35 at z = 0. Measuring this evolution, which should be possible using the Sloan Digital Sky Survey, would place constraints on models for galaxy formation. In addition, we evaluate the effects of the evolution of galaxy formation on estimates of Ω from cluster mass-to-light ratios, finding that while Ω(z) increases with z, the estimate Ωest(z) actually decreases. This effect is due to the combination of galaxy bias and the relative fading of cluster galaxies with respect to field galaxies. Finally, these effects provide a possible explanation for the Butcher-Oemler effect, the excess of blue galaxies in clusters at redshift z ~ 0.5.
New applications of organometallic catalysts in organic chemistry

An overview is provided of our work on tin hydride-catalyzed processes, palladi- um-catalyzed coupling reactions, and asymmetric catalysis with "planar-chiral" heterocycles.
Dynamical response of correlated electrons in solids probed by inelastic scattering experiments: an ab initio theoretical perspective

Abstract We present results of ab initio theoretical investigations of the excitation spectra of correlated electrons in metals (Al, K, and Li) and their interplay with inelastic scattering experiments. We resolve various anomalies contained in the data, which were originally viewed as signatures of strong dynamical electronic correlations; we show that, instead, the anomalies are due to band-structure effects. The underlying theoretical framework in our density–response calculations is time-dependent density-functional theory; with this scheme we discuss the lifetime of the K plasmon, and the dynamical structure factor of Al. From a self-consistent solution of the Dyson equation in the GW approximation for the electron self-energy, we discuss the electron momentum density in Li. Our results and methods point to a new way of thinking about electronic excitations in real materials. The main challenge ahead is the proper treatment of dynamical correlations for realistic representations of the band structure.
Unstable minimal surfaces of annulus type in manifolds

Unstable minimal surfaces are the unstable stationary points of the Dirichlet integral. In order to obtain unstable solutions, the method of the gradient flow together with the minimax- principle is generally used, an application of which was presented in (19) for minimal surfaces in Euclidean space. We extend this theory to obtain unstable minimal surfaces in Riemannian manifolds. In particular, we consider minimal surfaces of annulus type.
Optimal placement of actuators and sensors in control‐augmented structural optimization

A control-augmented structural synthesis methodology is presented in which actuator and sensor placement is treated in terms of (0,1) variables. Structural member sizes and control variables are treated simultaneously as design variables. A multiobjective utopian approach is used to obtain a compromise solution for inherently conflicting objective functions such as strucutal mass control effort and number of actuators. Constraints are imposed on transient displacements, natural frequencies, actuator forces and dynamic stability as well as controllability and observability of the system. The combinatorial aspects of the mixed - (0,1) continuous variable design optimization problem are made tractable by combining approximation concepts with branch and bound techniques. Some numerical results for example problems are presented to illustrate the efficacy of the design procedure set forth.
Manufacturing of two and three-dimensional micro/nanostructures by integrating optical tweezers with chemical assembly

Optical tweezers have been used as versatile tools for non-contact manipulation of micrometer-sized entities. This paper proposes a hybrid micro/nanoscale manufacturing system using optical tweezers and chemical linkages for fabricating 2D and 3D micro/nanostructures. A holographic multiple trap optical tweezers system is first used to trap particles in a desired pattern. The particles are then connected to form rigid units using suitable chemistry. Connection schemes based on gold seeding, complementary-DNA linkage and streptavidin-biotin chemistry are presented and possible applications of this technique are explored. This method combines the advantages of top-down and bottom-up approaches and is compatible with organic and inorganic materials.
Assignment Messages and Exchanges

"Assignment messages" are maximally general messages to describe substitutable preferences by means of a linear program. With "inte ger assignment messages," there exist integer-valued Walrasian allo cations, extending a result of Lloyd S. Shapley and Martin Shubik (1971). Any pure Nash equilibrium profile of the Walrasian mecha nism with participants limited to assignment messages is also a Nash equilibrium of the unrestricted Walrasian mechanism. Assignment exchanges are generalizations of single-product double auctions and are related to ascending multi-product clock auctions and the Vickrey mechanism. Assignment messages also have additional applications in mechanism design. (JEL D44, D82)
Polynomial regression under arbitrary product distributions

In recent work, Kalai, Klivans, Mansour, and Servedio (2005) studied a variant of the "Low-Degree (Fourier) Algorithm" for learning under the uniform probability distribution on {0,1} n . They showed that the L 1 polynomial regression algorithm yields agnostic (tolerant to arbitrary noise) learning algorithms with respect to the class of threshold functions--under certain restricted instance distributions, including uniform on {0,1} n and Gaussian on ? n . In this work we show how all learning results based on the Low-Degree Algorithm can be generalized to give almost identical agnostic guarantees under arbitrary product distributions on instance spaces X 1×???×X n . We also extend these results to learning under mixtures of product distributions. The main technical innovation is the use of (Hoeffding) orthogonal decomposition and the extension of the "noise sensitivity method" to arbitrary product spaces. In particular, we give a very simple proof that threshold functions over arbitrary product spaces have ?-noise sensitivity $O(\sqrt{\delta})$ , resolving an open problem suggested by Peres (2004).
Crystallization of Random Trigonometric Polynomials

We give a precise measure of the rate at which repeated differentiation of a random trigonometric polynomial causes the roots of the function to approach equal spacing. This can be viewed as a toy model of crystallization in one dimension. In particular we determine the asymptotics of the distribution of the roots around the crystalline configuration and find that the distribution is not Gaussian.
Vectorized multigrid fluid flow calculations on a CRAY X-MP/48

Discussion d'une methode de vectorisation pour le calcul des ecoulements de recirculation multidimensionnels. L'algorithme utilise un operateur de relaxation de Gauss-Seidel couple avec une technique multigrille. La vectorisation est effectuee sur un CRAY X-MP/48
Positivity of Partitioned Hermitian Matrices with Unitarily Invariant Norms

We give a short proof of a recent result of Drury on the positivity of a \(3\times 3\) matrix of the form \((\Vert R_i^*R_j\Vert _{\mathop {\mathrm{tr}}\,})_{1 \le i, j \le 3}\) for any rectangular complex (or real) matrices \(R_1, R_2, R_3\) so that the multiplication \(R_i^*R_j\) is compatible for all \(i, j,\) where \(\Vert \cdot \Vert _{\mathop {\mathrm{tr}}\,}\) denotes the trace norm. We then give a complete analysis of the problem when the trace norm is replaced by other unitarily invariant norms.
Rational emotive behavior therapy: A Tough-Minded therapy for a Tender-Minded profession

Objections to Rational-Emotive Behavior Therapy (REBT) seem to exceed the mere rational preference for one approach over another. Ziegler suggested that James’s dichotomy between Tough- and Tender-Mindedness might explain REBT’s appeal to some and its failure to attract others. REBT is a predominantly Tough-Minded therapy, but the counseling profession is largely Tender Minded. In this article, the author examines why Tender-Minded counselors may not accept REBT, what common misperceptions of REBT may contribute to this rejection, and how the two might be reconciled. Intervention strategies for Tender-Minded counselors are suggested.
First-principles study of iron oxyfluorides and lithiation of FeOF

First-principles studies of iron oxyfluorides in the FeF2 rutile framework (FeOxF2−x, 0 x 1) are performed using density functional theory (DFT) in the general gradient approximation (GGA) with a Hubbard U correction. Studies of O/F orderings reveal FeOF to be particularly stable compared to other FeOxF2−x (x = 1) structures, where FeF2-FeOF mixing is not energetically favored. The band gap of FeF2 is found to decrease as oxygen is substituted into its structure. The GGA + U electronic structure evolves from that of a Mott-Hubbard insulator (x = 0) to a charge transfer semiconductor (x = 1). Lithiation studies reveal that lithiation sites offering mixed O/F environments are the most stable. An insertion voltage plateau up to Li0.5FeOF on lithiation is found, in agreement with recent Li-ion battery experiments. The energetics of further lithiation with respect to conversion scenarios are discussed.
Proposal to measure the quasiparticle poisoning time of Majorana bound states

We propose a method of measuring the fermion parity lifetime of Majorana fermion modes due to quasiparticle poisoning. We model quasiparticle poisoning by coupling the Majorana modes to electron reservoirs, explicitly breaking parity conservation in the system. This poisoning broadens and shortens the resonance peak associated with Majorana modes. In a two-lead geometry, the poisoning decreases the correlation in current noise between the two leads from the maximal value characteristic of crossed Andreev reflection. The latter measurement allows for calculation of the poisoning rate even if the temperature is much higher than the resonance width.
Reconstructing the Cosmic Evolution of Quasars from the Age Distribution of Local Early-Type Galaxies

We use the spectra of ≈22,000 nearby early-type galaxies from the Sloan Digital Sky Survey (SDSS) to determine the age distribution of these galaxies as a function of their velocity dispersion σv in the range 100 σv 280 km s-1. We then combine the inferred age distributions with the local abundance of spheroids, including early-type galaxies and late-type bulges, to predict the evolution of the quasar luminosity function (LF) in the redshift range 0 < z 6. We make the following simple assumptions: (1) the formation of stars in each galaxy, at the epoch identified with the mean mass-weighted stellar age, is accompanied by the prompt assembly of the nuclear supermassive black hole (SMBH); (2) the mass of the SMBH obeys the MBH-σv correlation observed in nearby galaxies; (3) the SMBH radiates at a fraction fEdd of the Eddington limit for a fixed duration tq and is identified as a luminous quasar during this epoch; and (4) the intrinsic dispersions in the Eddington ratio and the MBH-σv relation produce a combined scatter of Δ log Lq around the mean logarithmic quasar luminosity log Lq at fixed σv. These assumptions require that the SMBH remnants of quasars with Lbol 1012.5fEdd L☉ reside predominantly in bulges of late-type galaxies. We find that evolution of the observed quasar LF can be fit over the entire redshift range in this simple model, 0 < z 6, with the choices of 0.6 Δ log Lq 0.9, 6 × 107 tq 8 × 107 yr, and 0.3 fEdd 0.5. We find no evidence that any of the model parameters evolves with redshift, supporting the strong connection between the formation of stars and nuclear SMBHs in spheroids.
Next generation video coding for mobile applications: industry requirements and technologies

Handheld battery-operated consumer electronics devices such as camera phones, digital still cameras, digital camcorders, and personal media players have become very popular in recent years. Video codecs are extensively used in these devices for video capture and/or playback. The annual shipment of such devices already exceeds a hundred million units and is growing, which makes mobile battery-operated video device requirements very important to focus in video coding research and development. This paper highlights the following unique set of requirements for video coding for these applications: low power consumption, high video quality at low complexity, and low cost, and motivates the need for a new video coding standard that enables better trade-offs of power consumption, complexity, and coding efficiency to meet the challenging requirements of portable video devices. This paper also provides a brief overview of some of the video coding technologies being presented in the ITU-T Video Coding Experts Group (VCEG) standardization body for computational complexity reduction and for coding efficiency improvement in a future video coding standard.
Effects of non-idealities and quantization of the center of mass motion on symmetric and asymmetric collective states in a collective state atomic interferometer

We investigate the behavior of an ensemble of N non-interacting, identical atoms excited by a laser. In general, the i-th atom sees a Rabi frequency Ωi, an initial position dependent laser phase ϕi, and a motion induced Doppler shift of δi. When Ωi or δi is distinct for each atom, the system evolves into a superposition of 2N intercoupled states, of which there are N+1 symmetric and 2N-(N+1) asymmetric collective states. For a collective state atomic interferometer (COSAIN), we recently proposed, it is important to understand the behavior of all the collective states under various conditions. In this paper, we show how to formulate the properties of these states under various non-idealities, and use this formulation to understand the dynamics thereof. We also consider the effect of treating the center of mass degree of freedom of the atoms quantum mechanically on the description of the collective states, illustrating that it is indeed possible to construct a generalized collective state, as needed for the...
Constraining a Simple Hadronization Model of Relativistic Heavy-Ion Collisions Using Hadronic Observables

A complicating factor in using hadrons as early probes for relativistic heavy-ion collisions is that they can undergo strong final-state rescattering with each other. This potentially causes hadronic observables to reflect the condition of the system at a late stage rather than at an early one. The present work uses a rescattering calculation with resonances to unfold these effects and thus use measured observables to constrain a simple initial-state hadronization model for Pb+Pb collisions at CERN energies. A model parameter set is found which qualitatively agrees with measured single and two-particle observables for Pb+Pb collisions. Comparisons are shown with experiment NA44 HBT results.
Signatures of Majorana fermions in topological insulator Josephson junction devices

We study theoretically the electrical current and low-frequency noise for a linear Josephson junction structure on a topological insulator, in which the superconductor forms a closed ring and currents are injected from normal regions inside and outside the ring. We find that this geometry offers a signature for the presence of gapless one-dimensional Majorana fermion modes that are predicted in the channel when the phase difference $\ensuremath{\varphi}$, controlled by the magnetic flux through the ring, is $\ensuremath{\pi}$. We show that for low temperature the linear conductance jumps when $\ensuremath{\varphi}$ passes through $\ensuremath{\pi}$, accompanied by nonlocal correlations between the currents from the inside and outside of the ring. We compute the dependence of these features on temperature, voltage, and linear dimensions, and discuss the implications for experiments.
Implementation in Undominated Nash Equilibria without Integer Games

A mechanism which uses neither integer games nor modulo games is shown to implement any social choice function in a production economy with private and (excludable) public goods. More precisely, th ...
The effect of stock option repricing on employee turnover

Abstract We examine whether repricing underwater stock options reduces executive and overall employee turnover using a sample of firms that reprice stock options in 1998 and a sample of firms with underwater stock options that choose not to reprice. We find little evidence that repricing affects executive turnover. However, using forfeited stock options to proxy for overall employee turnover, we find that 1999 employee turnover is negatively related to the 1998 repricing, suggesting that repricing helps prevent turnover due to underwater options. We find no evidence that the relation between turnover and repricing differs between high technology and nonhigh technology firms.
Regioselective coupling reactions of diiodophenol derivatives

Palladium catalyzed reactions of derivatives of 2,4-diiodophenol are explored. Coupling reactions with a series of terminal alkynes and formylation are found to be efficient and regioselective. Coupling with stananne reagents and alkenes do not work. The nature of the oxygen protecting group is critical. The phytotoxic natural product, Eutypine, is synthesized by using regioselective formylation and alkyne coupling. An approach to the plant antimicrobial compound Plicatin B is examined.
Formal Total Syntheses of the β-Lactam Antibiotics Thienamycin and PS-5

Chiral nonracemic acetylenic acids of general structure 11, prepared using the Schreiber modification of the Nicholas reaction, have been converted to β-amino acid derivatives of type 12 by a two-step sequence involving Curtius rearrangement followed by oxidative cleavage of the acetylenic bond. Amino acid derivatives 12 are excellent precursors for β-lactams of the carbapenem class, including the important antibiotics thienamycin (1) and PS-5 (4).
Automated Measurement of the Bit-Error Rate as a Function of Signal-to-Noise Ratio for Microwave Communications Systems

The performance of microwave systems and components for digital data transmission can be characterized by a plot of the bit-error rate as a function of the signal-to-noise ratio (or Eb/No). Methods for the efficient automated measurement of bit-error rates and signal-to-noise ratios, developed at NASA Lewis Research Center, are described. Noise measurement considerations and time requirements for measurement accuracy, as well as computer control and data processing methods, are discussed.
Quasicoherent sheaves on complex noncommutative two-tori

We introduce the notion of a quasicoherent sheaf on a complex noncommutative two-torus T as an ind-object in the category of holomorphic vector bundles on T. Extending the results of [10] and [9] we prove that the derived category of quasicoherent sheaves on T is equivalent to the derived category of usual quasicoherent sheaves on the corresponding elliptic curve. We define the rank of a quasicoherent sheaf on T that can take arbitrary nonnegative real values. We study the category Qcoh(nT) obtained by taking the quotient of the category of quasicoherent sheaves by the subcategory of objects of rank zero (called torsion sheaves). We show that projective objects of finite rank in Qcoh(nT) are classified up to an isomorphism by their rank. We also prove that the subcategory of objects of finite rank in Qcoh(nT) is equivalent to the category of finitely presented modules over a semihereditary algebra.
Approaches to the preparation of (Z)-1,2-difluorostilbenes

Abstract Methodology directed at the preparation of (Z)-1,2-difluorostilbenes has been evaluated. For symmetrical (Z)-1,2-difluorostilbenes, photochemical isomerization of the isomeric (E)-1,2-difluorostilbenes, and HPLC separation of the mixture of stilbene isomers is a reasonable route to a particular (Z)-stilbene. An alternative approach to both symmetrical and/or unsymmetrical (Z)-1,2-difluorostilbenes has been developed via stereospecific Pd(0) coupling of (E)-1,2-difluoro-aryl-ethenyltributylstannanes under Stille-Liebiskind conditions with aryl idodies. The requisite arylstannanes can be obtained via the reported route developed by Davis or via (E)-1,2-difluorovinyltributylstannane – a new route described in this work. The methodology tolerates almost any functionality in the aryl ring, is easily carried out, is stereospecific and provides the first general route to (Z)-1,2-difluorostilbenes.
Two-Nucleon Scattering Without Partial Waves Using a Momentum Space Argonne V18 Interaction

We test the operator form of the Fourier transform of the Argonne V18 potential by computing selected scattering observables and all Wolfenstein parameters for a variety of energies. These are compared to the GW-DAC database and to partial wave calculations. We represent the interaction and transition operators as expansions in a spin-momentum basis. In this representation the Lippmann–Schwinger equation becomes a six channel integral equation in two variables. Our calculations use different numbers of spin-momentum basis elements to represent the on- and off-shell transition operators. This is because different numbers of independent spin-momentum basis elements are required to expand the on- and off-shell transition operators. The choice of on and off-shell spin-momentum basis elements is made so that the coefficients of the on-shell spin-momentum basis vectors are simply related to the corresponding off-shell coefficients.
Direct Catalytic Asymmetric Synthesis of N-Heterocycles from Commodity Acid Chlorides by Employing α,β-Unsaturated Acylammonium Salts

Taming the beast, asymmetrically: Modulation of the reactivity of acid chlorides, using cinchona alkaloid catalysts, results in chiral α,β-unsaturated acylammoniums, which react with nucleophiles enantioselectively to give pyrrolidinones, piperid-2-ones, and dihydropyridinones. This nucleophile-catalyzed Michael/proton transfer/lactamization or lactonization organocascade leads to chiral intermediates previously employed for the synthesis of bioactive pharmaceuticals.