cssi/SciSciGPT-SciSciNet huggingface dataset:
Topological Automorphic Forms

The authors apply a theorem of J. Lurie to produce cohomology theories associated to certain Shimura varieties of type $U(1,n-1)$. These cohomology theories of topological automorphic forms ($\mathit{TAF}$) are related to Shimura varieties in the same way that $\mathit{TMF}$ is related to the moduli space of elliptic curves. Table of Contents: $p$-divisible groups; The Honda-Tate classification; Tate modules and level structures; Polarizations; Forms and involutions; Shimura varieties of type $U(1,n-1)$; Deformation theory; Topological automorphic forms; Relationship to automorphic forms; Smooth $G$-spectra; Operation on $\mathit{TAF}$; Buildings; Hypercohomology of adele groups; $K(n)$-local theory; Example: chromatic level $1$; Bibliography; Index. (MEMO/204/958)
Demonstration of real-time spectrum sensing for cognitive radio

Spectrum sensing detects the availability of the radio frequency spectrum in a real-time fashion, which is essential and vital to cognitive radio. The requirement for real-time processing indeed poses challenges on implementing spectrum sensing algorithms. Trade-off between the complexity and the effectiveness of spectrum sensing algorithms should be taken into consideration. In this paper, a fast Fourier transform (FFT) based spectrum sensing algorithm called FAR is introduced. It is the beauty of the algorithm that the decision variable is insensitive to noise level. Parameter selection for the algorithm is considered as well, toward minimizing computational complexity. A small form factor (SFF) software denned radio (SDR) development platform (DP) is employed to implement a spectrum sensing receiver with FAR algorithm. Performance of FAR algorithm is evaluated on the SFF SDR DP, and real-time spectrum sensing is demonstrated. FAR algorithm is friendly to hardware implementation and it is effective to detect signals at low SNR.
Modeling Species Inhibition and Competitive Adsorption in Urea-SCR Catalysts

Although the urea-SCR technology exhibits high NOx reduction efficiency over a wide range of temperatures among the lean NOx reduction technologies, further improvement in low-temperature performance is required to meet the future emission standards and to lower the system cost. In order to improve the catalyst technologies and optimize the system performance, it is critical to understand the reaction mechanisms and catalyst behaviors with respect to operating conditions. Urea-SCR catalysts exhibit poor NOx reduction performance at low temperature operating conditions (T < 150 C). We postulate that the poor performance is either due to NH3 storage inhibition by species like hydrocarbons or due to competitive adsorption between NH3 and other adsorbates such as H2O and hydrocarbons in the exhaust stream. In this paper we attempt to develop one-dimensional models to characterize inhibition and competitive adsorption in Fe-zeolite based urea-SCR catalysts based on bench reactor experiments. We further use the competitive adsorption (CA) model to develop a standard SCR model based on previously identified kinetics. Simulation results indicate that the CA model predicts catalyst outlet NO and NH3 concentrations with minimal root mean square error.
Interference Channels With Arbitrarily Correlated Sources

Communicating arbitrarily correlated sources over interference channels is considered in this paper. A sufficient condition is found for lossless transmission of a pair of correlated sources over a discrete memoryless interference channel. With independent sources, the sufficient condition reduces to the Han-Kobayashi achievable rate region for interference channels. For sources with a special correlation structure, the proposed region reduces to the known achievable region for interference channels with common information. Moreover, the proposed coding scheme is optimal for transmitting such set of correlated sources over a class of deterministic interference channels as defined in El Gamal and Costa, 1982.
Generic device abstractions for information processing technologies

Abstract Current CMOS devices operate at about six orders of magnitude above the k B T ln 2 J/bit switching limit imposed by physics. Continued scaling of devices that are then densely packed and operated at attainable frequencies will result in the generation of thermal loads that cannot be managed by any known heat removal technology. Herein, we introduce an extension of the device energy barrier model to include extremely scaled interconnect systems. It is shown that the dissipation per device in interconnected circuits will considerably exceed isolated device dissipation, which is on the order of a few k B T . We next discuss possible successor/complementary logic devices that reduce the level of heat generation and we discuss new non-volatile memory techniques that could radically impact information processing architectures and hence the performance requirements for logic devices.
Product liability litigation: an issue of Merck and lawsuits over Vioxx

Merck & Co., Inc. pulled Vioxx, a $2.5 billon a year nonsteroidal anti-inflammatory drug, off the shelf in September 2004. The removal followed a study that was published reporting Vioxx increased the risk of Cardiovascular Events (CE) after long-term use. In the years since then, many lawsuits have been filed against Merck. This article examines the incentive to recall a product and the effects of Merck pulling Vioxx from the shelves. Using the market's expected Internal Rate of Return (IRR) for Merck, I calculate the expected profits from future Vioxx sales. I then use data on financial effects to show how the Market Value (MV) of Merck reflects their probability of winning legal cases concerning Vioxx.
Relating different approaches to nuclear broadening

Abstract Transverse momentum broadening of fast partons propagating through a large nucleus is proportional to the average color field strength in the nucleus. In this work, the corresponding coefficient is determined in three different frameworks, namely, in the color dipole approach, in the approach of Baier et al. and in the higher twist factorization formalism. This result enables one to use a parametrization of the dipole cross section to estimate the values of the gluon transport coefficient and of the higher twist matrix element, which is relevant for nuclear broadening. A considerable energy dependence of these quantities is found. In addition, numerical calculations are compared to data for nuclear broadening of Drell–Yan dileptons, J / ψ and ϒ mesons. The scale dependence of the strong coupling constant leads to measurable differences between the higher twist approach and the other two formalisms.
BLAZAR GAMMA-RAYS, SHOCK ACCELERATION, AND THE EXTRAGALACTIC BACKGROUND LIGHT

The observed spectra of blazars, their intrinsic emission, and the underlying populations of radiating particles are intimately related. The use of these sources as probes of the extragalactic infrared background, a prospect propelled by recent advances in TeV-band telescopes, soon to be augmented by observations by NASA's upcoming Gamma-Ray Large Area Space Telescope (GLAST), has been a topic of great recent interest. Here, it is demonstrated that if particles in blazar jets are accelerated at relativistic shocks, then GAMMA-ray spectra with indices less than 1.5 can be produced. This, in turn, loosens the upper limits on the near infrared extragalactic background radiation previously proposed. We also show evidence hinting that TeV blazars with flatter spectra have higher intrinsic TeV GAMMA-ray luminosities and we indicate that there may be a correlation of flatness and luminosity with redshift.
Example centric programming

Programmers tend to understand programs by thinking of concrete examples. Example Centric Programming seeks to add IDE support for examples throughout the process of programming. Instead of programmers interpreting examples in their head, the examples are written down and the IDE interprets them automatically. Advanced UI techniques are used to present the results closely integrated with the code. Traditionally distinct programming tools (the editor, Read-Eval-Print-Loop, debugger, and test runner) are unified into a single tool that might be called an example-enlightened editor. This is expected to benefit a wide spectrum of programming activities, for both novice and experienced programmers. Some novel methods for testing and development are made possible. In the longer term, example centrism has implications for the design of future programming languages. A prototype has been implemented for Java in Eclipse.
Probability of Detecting a Planetary Companion during a Microlensing Event

The averaged probability of detecting a planetary companion of a lensing star during a microlensing event toward the Galactic center when the planet to star mass ratio q = 0.001 is shown to have a maximum exceeding 10% at an orbit semimajor axis near 1.5 AU for a uniform distribution of impact parameters. This peak value is somewhat lower than the maximum of 17% obtained by Gould & Loeb in 1992, but it is raised to more than 20% for a distribution of source-lens impact parameters that is determined by the efficiency of event detection. Although these probabilities, based on a signal-to-noise ratio (S/N) detection criterion, are model and assumption dependent, the fact that they change in predictable ways as functions of the orbit semimajor axes but remain robust for plausible variations of all the relevant Galactic parameters implies that they are representative of real values. In addition, the averaging procedures are carefully defined, and they determine the dependence of the detection probabilities on several properties of the Galaxy. The probabilities for other planet to star mass ratios can be estimated from an approximate scaling of q1/2. A planet is assumed detectable if the perturbation of the single-lens light curve exceeds 2/(S/N) sometime during the event, where it is understood that at least 20 consecutive photometric points during the perturbation are necessary to confirm the detection. S/N is the instantaneous value for the amplified source. In addition, 2 m telescopes with 60 s integrations in I band with high time resolution photometry throughout the duration of an ongoing event are assumed. The probabilities are derived as a function of semimajor axis a of the planetary orbit, where the peak probability occurs where a is approximately the mean Einstein ring radius of the distribution of lenses along the line of sight. The probabilities remain significant for 0.6 a 10 AU. Dependence of the detection probabilities on the lens mass function, luminosity function of the source stars as modified by extinction, distribution of source-lens impact parameters, and the line of sight to the source are also determined, and the probabilities are averaged over the distribution of the projected position of the planet onto the lens plane, over the lens mass function, over the distribution of impact parameters, over the distribution of lens and sources along the line of sight, and over the I-band luminosity function of the sources adjusted for the source distance and extinction. The probability for a particular impact parameter and particular source I magnitude but averaged over remaining degenerate parameters also follows from the analysis. In the latter case, the extraction of the probability as a function of a for a particular q from the empirical data from a particular event is indicated.
The Prospects for Coal-To-Liquid Conversion: A General Equilibrium Analysis

We investigate the economics of coal-to-liquid (CTL) conversion, a polygeneration technology that produces liquid fuels, chemicals, and electricity by coal gasification and Fischer–Tropsch process. CTL is more expensive than extant technologies when producing the same bundle of output. In addition, the significant carbon footprint of CTL may raise environmental concerns. However, as petroleum prices rise, this technology becomes more attractive especially in coal-abundant countries such as the U.S. and China. Furthermore, including a carbon capture and storage (CCS) option could greatly reduce its CO2 emissions at an added cost. To assess the prospects for CTL, we incorporate the engineering data for CTL from the U.S. Department of Energy (DOE) into the MIT Emissions Prediction and Policy Analysis (EPPA) model, a computable general equilibrium model of the global economy. Based on DOE’s plant design that focuses mainly on liquid fuels production, we find that without climate policy, CTL has the potential to account for up to a third of the global liquid fuels supply by 2050 and at that level would supply about 4.6% of global electricity demand. A tight global climate policy, on the other hand, severely limits the potential role of the CTL even with the CCS option, especially if low-carbon biofuels are available. Under such a policy, world demand for petroleum products is greatly reduced, depletion of conventional petroleum is slowed, and so the price increase in crude oil is less, making CTL much less competitive.
Photoinduced Electron Transfer in Tetrathiafulvalene−Porphyrin−Fullerene Molecular Triads

The two molecular triads 1a and 1b consisting of a porphyrin (P) covalently linked to a fullerene (C60) electron acceptor and tetrathiafulvalene (TTF) electron-donor moiety were synthesized, and their photochemical properties were determined by transient absorption and emission techniques. Excitation of the free-base-porphyrin moiety of the TTF−P2 H−C60 triad 1a in tetrahydro-2-methylfuran solution yields the porphyrin first excited singlet state TTF−1P2 H−C60, which undergoes photoinduced electron transfer with a time constant of 25 ps to give TTF−P2 H.+−C60.−. This intermediate charge-separated state has a lifetime of 230 ps, decaying mainly by a charge-shift reaction to yield a final state, TTF.+−P2 H−C60.−. The final state has a lifetime of 660 ns, is formed with an overall yield of 92%, and preserves ca. 1.0 eV of the 1.9 eV inherent in the porphyrin excited state. Similar behavior is observed for the zinc analog 1b. The TTF-PZn.+−C60.− state is formed by ultrafast electron transfer from the porphyrinatozinc excited singlet state with a time constant of 1.5 ps. The final TTF.+−PZn−C60.− state is generated with a yield of 16%, and also has a lifetime of 660 ns. Although charge recombination to yield a triplet has been observed in related donor-acceptor systems, the TTF.+−P−C60.− states recombine to the ground state, because the molecule lacks low-energy triplet states. This structural feature leads to a longer lifetime for the final charge-separated state, during which the stored energy could be harvested for solar-energy conversion or molecular optoelectronic applications.
A disjointness type property of conditional expectation operators

We give a characterization of conditional expectation operators through a disjointness type property similar to band preserving operators. We say that the operator $T:X\to X$ on a Banach lattice $X$ is semi band preserving if and only if for all $f, g \in X$, $f \perp Tg$ implies that $Tf \perp Tg$. We prove that when $X$ is a purely atomic Banach lattice, then an operator $T$ on $X$ is a weighted conditional expectation operator if and only if $T$ is semi band preserving.
CONSIDERATIONS ON THE MAGNETIC FIELD PROBLEM IN SUPERCONDUCTING THIN FILMS

We adapt the results obtained in a previous paper on the magnetic field dependence of the energy gap in superconductivity for bulk specimen to thin-film superconductors, using the model of discrete quantization in momentum space. Only the case of parallel and constant external magnetic field along the film surfaces is considered. A series of elementary theorems and some specific calculations lead to the conclusions: (1) A second-order phase transition should be observed at all temperatures for thin film thicknesses. (2) A simple scaling rule exists concerning the field and temperature dependence on the energy gap. (3) The critical field ${H}_{c}$ depends on thickness $L$ and reduced temperature $t$ like ${H}_{c}\ensuremath{\sim}{L}^{\ensuremath{-}\frac{3}{2}}{[\mathrm{ln}(\frac{1}{t})]}^{\frac{1}{2}}$ for not too thin films ($L\ensuremath{\gtrsim}0.5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ cm). The behavior changes as the film becomes very thin or as the temperature becomes moderately low. A crude comparison with available experimental data seems to bear out our conclusions qualitatively.
Use of Electrospun Nanofiber Web for Protective Textile Materials as Barriers to Liquid Penetration

To examine the potential of electrospun nanofibrous webs as barriers to liquid penetration in protective clothing systems for agricultural workers, layered fabric systems with electrospun polyurethane fiber web layered on spunbonded nonwoven were developed. Barrier performance was evaluated for the layered fabric systems with different levels of electrospun web area density, using three pesticide mixtures that represent a range of surface tension and viscosity. Effects of electrospun web density on air permeability and water vapor transmission were assessed as indications of thermal comfort performance. Pore size distribution was measured to examine the effect of electrospun fiber web layers on pore size. Penetration testing showed that a very thin layer of electrospun polyurethane web significantly improved barrier performance for challenge liquids with a range of physicochemical properties. Air permeability decreased with increasing electrospun web area density, but was still higher than most of protect...
On the effectiveness of residue code checking for parallel two's complement multipliers

The effectiveness of residue code checking for online error detection in parallel two's complement multipliers has only up until now been evaluated experimentally for few architectures. In this paper a formal analysis is given for most of the current multiplication schemes. Based on this analysis it is shown which check bases are appropriate, and how the original scheme has to be extended for complete error detection at the input registers and Booth recoding circuitry. In addition, we argue that the hardware overhead for checking can be reduced by approximately one half if a small latency in error detection is acceptable. Schemes for structuring the checking logic in order to guarantee it to be self-testing, and thus achieve the totally self-checking goal for the overall circuit, are also derived.
Disambiguation of super parts of speech (or supertags): almost parsing

In a lexicalized grammar formalism such as Lexicalized Tree-Adjoining Grammar (LTAG), each lexical item is associated with at least one elementary structure (supertag) that localizes syntactic and semantic dependencies. Thus a parser for a lexicalized grammar must search a large set of supertags to choose the right ones to combine for the parse of the sentence. We present techniques for disambiguating supertags using local information such as lexical preference and local lexical dependencies. The similarity between LTAG and Dependency grammars is exploited in the dependency model of supertag disambiguation. The performance results for various models of supertag disambiguation such as unigram, trigram and dependency-based models are presented.
Exact and Approximate Solution of Constrained Dynamic Combinatorial Problems in Space

In a recent issue of this Journal the author confronted an important set of spatial combinatorial problems of a sequential nature and suggested a method to obtain approximate solutions rather efficiently (Kuenne [4]). In that article the problem is defined formally; its structural resemblances to the transportation, travelling salesman, and weighted set covering problems were discussed, and several examples were solved heuristically. Although existing combinatorial approaches such as branch and bound were mentioned briefly, and a role assigned them in the approximative algorithm, the view was expressed that such paths to exact solution were infeasible computationally.
Missing observations in Multivariate Regression: Efficiency of a First Order Method

Abstract It is shown that the information contained in the incomplete portion of the sample that is relevant in the estimation of the regression parameters is in the form of a linear restriction. Although the parameters of this restriction are generally unknown they can be estimated in terms of the complete portion of the sample. It is then shown that regression parameter estimates based on first order methods, say, Ĉ, differ from the ordinary least squares estimates based only on the complete portion of the sample, say Ĉ LS , by a function of the extent to which Ĉ LS fails to satisfy the above named restriction. The asymptotic variance-co-variance matrix of Ĉ is derived under various conditions and compared to that of Ĉ LS .
The Degrees of Freedom Region of the MIMO Interference Channel With Hybrid CSIT

The degrees of freedom (DoF) region of the two-user multiple-input multiple-output (MIMO) interference channel is established under hybrid CSIT models in which there is some combination of instantaneous, delayed or no channel state information at the transmitters (CSIT) of each of the four channel matrices. In a standard version of this hybrid CSIT model, there is delayed CSIT at one transmitter and instantaneous CSIT at the other transmitter of incoming channel matrices at their respective unpaired receivers. The DoF regions for this standard model is established and, moreover, it is shown to be applicable to a large class of hybrid CSIT models. In so doing, a new DoF-optimal achievable scheme based on a combination of transmit beamforming and interference alignment is developed. Conditions are obtained on the numbers of antennas at each of the four terminals such that the DoF region under hybrid CSIT is equal to that under (a) instantaneous CSIT and (b) delayed CSIT. It is also demonstrated that by alternating between constituent hybrid CSIT states it is possible to obtain synergistic DoF benefits.
How are shorts informed?: Short sellers, news, and information processing

Abstract We find that a substantial portion of short sellers' trading advantage comes from their ability to analyze publicly available information. Using a database of short sales combined with a database of news releases, we show that the well-documented negative relation between short sales and future returns is twice as large on news days and four times as large on days with negative news. Further, we find that the most informed short sales are not from market makers but rather from clients, and we find only weak evidence that short sellers anticipate news events. Overall, the evidence suggests that public news provides valuable trading opportunities for short sellers who are skilled information processors.
Real-time color grading and defect detection of food products

Manufacturing processes that utilize natural products as raw materials for forming their deliverables face additional challenges in the areas of quality control and inspection. This comes about from the natural variability that occurs in the products. Systems to automate this activity have been difficult to design and implement from the view of algorithm complexity which impacts the computational requirements for real-time execution. This paper will describe a technique for recognizing global or systematic defects on poultry carcasses. A method for implementing the technique that is capable of executing at a rate of about 180 birds per minute is described.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Symmetry and model checking

We show how to exploit symmetry in model checking for concurrent systems containing many identical or isomorphic components. We focus in particular on those composed of many isomorphic processes. In many cases we are able to obtain significant, even exponential, savings in the complexity of model checking.
Simultaneous mesh generation and partitioning for Delaunay meshes

In this paper, we present a new approach for the parallel generation and partitioning of unstructured 3D Delaunay meshes. The new approach couples the mesh generation and partitioning problems into a single optimization problem. Traditionally, these two problems are solved separately, first generating the mesh (usually sequentially) and then partitioning the mesh, either sequentially or in parallel. In the traditional approach, the overheads due to I/O and data movement exceed 50% of the total execution time. Even if parallel partitioning schemes are employed, data movement, synchronization, and data structure translation overheads are high; for applications which require frequent remeshing (e.g. crack growth simulations), these overheads are prohibitive. We present a method for solving the mesh partitioning and placement problem simultaneously with the mesh generation problem. By eliminating unnecessary and redundant cache, local, and remote memory accesses, we can speed up the generation and redistribution process, for very large meshes, by almost an order of magnitude compared to traditional approaches. Our results show that we can achieve nearly perfect equi-distribution of mesh elements over the processors, while maintaining reasonably good separator size, all while improving the quality of the mesh by eliminating many of the problems inherent in traditional parallel constrained mesh generation.
Suicidality as a possible side effect of antidepressant treatment.

On March 22, 2004, the U.S. Food and Drug Administration (FDA) issued a health advisory informing the public that manufacturers of several popular antidepressants have been asked to include a warning statement on product labeling. This warning statement recommends that antidepressant-treated patients—both children and adults—should be closely monitored for worsening of depression or emergence of suicidal behavior. The full text of the advisory, along with supporting information and presentations from the February 2004 meeting on which this advisory was based, can be found on the FDA’s Web site at http://www.fda.gov/ cder/drug/antidepressants/default.htm.
Quantifying Unmixedness in Lean Premixed Combustors Operating at High-Pressure, Fired Conditions

Lean premixed combustor manufacturers require premixer concepts that provide homogeneity (mixedness) of the fuel which burns in the main flame. Ideally premixer evaluation would be conducted under realistic combustor operating conditions. However, current techniques typically are limited to cold—flow, low pressure (<14 atm) conditions or comparison of measured NOx emissions with others obtained in premixed systems. Thus, a simple, consistent method for quantifying unmixedness in lean premixed combustors operating at high pressure, fired operating conditions is proposed here, using the characteristic time model developed in the companion paper.Copyright © 1997 by ASME
SIMULATIONS OF HIGH-VELOCITY CLOUDS. I. HYDRODYNAMICS AND HIGH-VELOCITY HIGH IONS

We present hydrodynamic simulations of high-velocity clouds (HVCs) traveling through the hot, tenuous medium in the Galactic halo. A suite of models was created using the FLASH hydrodynamics code, sampling various cloud sizes, densities, and velocities. In all cases, the cloud-halo interaction ablates material from the clouds. The ablated material falls behind the clouds where it mixes with the ambient medium to produce intermediate-temperature gas, some of which radiatively cools to less than 10,000 K. Using a non-equilibrium ionization algorithm, we track the ionization levels of carbon, nitrogen, and oxygen in the gas throughout the simulation period. We present observation-related predictions, including the expected H I and high ion (C IV, N V, and O VI) column densities on sightlines through the clouds as functions of evolutionary time and off-center distance. The predicted column densities overlap those observed for Complex C. The observations are best matched by clouds that have interacted with the Galactic environment for tens to hundreds of megayears. Given the large distances across which the clouds would travel during such time, our results are consistent with Complex C having an extragalactic origin. The destruction of HVCs is also of interest; the smallest cloud (initial mass {approx} 120more » M{sub sun}) lost most of its mass during the simulation period (60 Myr), while the largest cloud (initial mass {approx} 4 x 10{sup 5} M{sub sun}) remained largely intact, although deformed, during its simulation period (240 Myr).« less
Lifetime of the Excited F Center

An investigation was carried out on the excited state of the $F$ center in various alkali halide crystals as a function of temperature. Results are presented on the time dependence of photoconductivity and luminescence following excitation by a very short, ${10}^{\ensuremath{-}8}$ sec, pulse of light. The data can be interpreted in terms of a simple energy-level diagram of the $F$ center consisting of a ground state and an excited state. Estimates are given of the depth of the excited state below the conduction band $\ensuremath{\Delta}E$, the frequency factor for thermal ionization $\frac{1}{{\ensuremath{\tau}}_{0}}$, and the radiative lifetime ${\ensuremath{\tau}}_{R}$, for KCl, KBr, KI, and NaCl. The radiative lifetime ${\ensuremath{\tau}}_{R}$ depends upon the alkali halide, but may be as long as ${10}^{\ensuremath{-}6}$ sec. Suggestions are made for understanding this long lifetime in view of the large oscillator strength of the $F$ center. The effect of $F$-center concentration and also of an admixture of $M$ centers is discussed.
Modeling Total Expenditure on Warranty Claims

We approximate the distribution of total expenditure of a retail company over warranty claims incurred in a fixed period [0, T], say the following quarter. We consider two kinds of warranty policies, namely, the non-renewing free replacement warranty policy and the non-renewing pro-rata warranty policy. Our approximation holds under modest assumptions on the distribution of the sales process of the warranted item and the nature of arrivals of warranty claims. We propose a method of using historical data to statistically estimate the parameters of the approximate distribution. Our methodology is applied to the warranty claims data from a large car manufacturer for a single car model and model year.
Forecasting Default with the Merton Distance to Default Model

We examine the accuracy and contribution of the Merton distance to default (DD) model, which is based on Merton's (1974) bond pricing model. We compare the model to a “naive” alternative, which uses the functional form suggested by the Merton model but does not solve the model for an implied probability of default. We find that the naive predictor performs slightly better in hazard models and in out-of-sample forecasts than both the Merton DD model and a reduced-form model that uses the same inputs. Several other forecasting variables are also important predictors, and fitted values from an expanded hazard model outperform Merton DD default probabilities out of sample. Implied default probabilities from credit default swaps and corporate bond yield spreads are only weakly correlated with Merton DD probabilities after adjusting for agency ratings and bond characteristics. We conclude that while the Merton DD model does not produce a sufficient statistic for the probability of default, its functional form is useful for forecasting defaults.
Ballistic limit curves for non-spherical projectiles impacting dual-wall spacecraft systems

Ballistic limit curves for dual-wall spacecraft systems are typically developed using ground-based hypervelocity impact tests with spherical projectiles. However, most orbital debris particles are not spherical and can take any shape. Non-spherical projectiles can also be more damaging than equal mass spherical projectiles. Although some recent efforts have examined the effects of non-spherical projectile impacts, ballistic limit curves for non-spherical projectiles are still not available. This paper presents the results of a study in which numerical simulation methods were used to develop ballistic limit curves for a variety of non-spherical projectile shapes impacting a typical dual-wall spacecraft configuration. Ballistic limit curves for non-spherical projectiles are presented and compared against that for spherical projectiles impacting the same wall system. It is found that long cylinder and long cone projectiles have a higher penetrating capability than all other projectile shapes considered, including spherical projectiles. The implication is that if a spacecraft wall system is designed using spherical projectile-based ballistic limit curves, the design will likely be non-conservative.
Gold-Catalyzed Oxidation of Propargylic Ethers with Internal C-C Triple Bonds: Impressive Regioselectivity Enabled by Inductive Effect.

Abstract Inductive perturbations of C–C triple bonds are shown to dictate the regiochemistry of gold-catalyzed oxidation of internal C–C triple bonds in the cases of propargylic ethers, resulting in highly regioselective formation of β-alkoxy-α,β-unsaturated ketones (up to >50/1 selectivity) via α-oxo gold carbene intermediates. Ethers derived from primary propargylic alcohols can be reliably transformed in good yields, and various functional groups are tolerated. With substrates derived from secondary propargylic alcohols, the development of a new P,N-bidentate ligand enables the minimization of competing alkyl group migration to the gold carbene center over the desired hydride migration; the preferred migration of a phenyl group, however, results in efficient formation of a α-phenyl-β-alkoxy-α,β-unsaturated ketone. These results further advance the surrogacy of a propargyl moiety to synthetically versatile enone function with reliable and readily predictable regioselectivity.
Gauge-Mediated Supersymmetry Breaking at an Intermediate Scale

In gauge-mediated SUSY breaking models, messengers transmit SUSY breaking from a partially hidden sector to the standard model sector via common standard model gauge interactions. The minimal set of messengers has quantum numbers of a 5 + \(\bar 5\) of SU(5); identical to the quantum numbers of the minimal Higgs sector of an SU(5) GUT. We show in a simple model with messenger masses of order the GUT scale that Higgs - messenger mixing quite naturally leads to a low energy MSSM with gluinos as the lightest supersymmetric particles [LSP]. We study the phenomenological consequences of such a model.
Norm Bounds for Ehrhart Polynomial Roots

M. Beck et al. found that the roots of the Ehrhart polynomial of a d-dimensional lattice polytope are bounded above in norm by 1+(d+1)!. We provide an improved bound which is quadratic in d and applies to a larger family of polynomials.
A Search for Radio Emission at the Bottom of the Main Sequence and Beyond

We have used the VLA to conduct a deep search for 3.6 cm radio emission from nearby very low mass stars and brown dwarfs. The G?del-Benz relation is used to predict radio luminosities for some very low mass stars and candidate brown dwarfs with measured X-ray fluxes. The predicted radio fluxes are quite small, whereas the measured radio flux from the brown dwarf candidate GY 31 in the ? Oph cloud is relatively strong. In light of our new observations, this object remains an anomaly. We present upper limits for our measured radio fluxes at 3.6 cm for our targets.
Polyacetyleneginsenoside-Ro, a novel triterpene saponin from Panax ginseng

Abstract A new oleanolic acid-derived saponin, polyacetyleneginsenoside-Ro ( 1 ), was isolated along with the known ginsenosides-Ro methyl ester ( 2 ), -Rf, -Rg1, -Rg2, and gingerglycolipid B from the roots of Panax ginseng C. A. Meyer. The new saponin was identified as a ginsenoside-Ro derivative containing a polyacetylene side chain by spectroscopic means including 1D and 2D NMR, and was found to inhibit the replication of human immunodeficiency virus type 1 (HIV-1) with an IC50 value of 13.4 μg/mL (11.1 μM).
Graphene-Based Optoelectronics

Owed to its extraordinary electronic, thermal, and optical properties, as well as its integration possibilities and low cost, graphene has emerged as an attractive material for a myriad of optoelectronic applications. Although just one atom-thick, single-layer graphene is capable of efficiently interacting with optical waves over a wide spectral range extending from terahertz to visible frequencies. Moreover, its intrinsic nature enables the integration of graphene with silicon-based photonic devices in CMOS compatible processes. This paper reviews and discusses recent progress on graphene-based optoelectronic devices for modulating, detecting, generating, and beam-shaping optical waves in a broad range of wavelengths extending from ∼500 nm to ∼500 μm.
A natural first approximation to low-thrust trajectories between satellite orbits of the earth and moon.

Low thrust satellite transfer between Earth and Moon orbits based on two-body trajectories and systematic synthesizing process
Propensity Rule for Novel Selective Double Photoexcitation of Helium Atoms in Strong Static Electric Fields

We studied the double photoexcitation spectra of helium in a strong dc electric field and compared the results with the recent experimental data of Harries et al. [Phys. Rev. Lett. 90, 133002 (2003)]. We derived the propensity rules based on the crossing or noncrossing of energies in the Stark map to predict the selective subset of doubly excited states that are preferentially populated in such experiments. It is shown that the propensity rule is a consequence of the ubiquitous correlation properties of doubly excited states in general.
Domestic constraints on regional cooperation: Explaining trade conflict in MERCOSUR

ABSTRACT This article seeks to account for the erratic patterns of conflict and cooperation observed in MERCOSUR since 1995. It argues that the marked deterioration of trade and diplomatic relations between Argentina and Brazil in the late 1990s and early 2000s is best explained in reference to domestic political constraints on inter-state cooperation. Two domestic-level dynamics shaped the national preferences for regional cooperation of Argentina and Brazil: state–society relations and intra-state cleavages. The recurrent instances of defection in the late 1990s reflected not only societal pressure but also the macroeconomic and political calculations of national policymakers. Tension among different state agencies sharing power over regional policy-making further undermined the coherence of member states' behavior toward their regional commitments. This ‘second-image’ explanation of conflict in MERCOSUR is illustrated with case studies of three major trade disputes between Argentina and Brazil: the 199...
Left ventricular volume reduction and reconstruction in ischemic cardiomyopathy.

Background: Ischemic cardiomyopathy can be the result of large or small my-ocardial infarctions or due to myocardial hibernation. Patients with an end-systolic volume index >100 mL/m2 do not benefit from revascularization alone and require an operation that reduces ventricular volume. Various approaches to reduce ventricular volume have been described. We applied several of these techniques in patients with end-stage ischemic cardiomyopathy. Methods: Forty eight patients with end-stage ischemic cardiomyopathy (Class III-IV) underwent left ventricular volume reduction operations with coronary revascularization and mitral valve repair or Alfieri valvoplasty. Fourteen patients underwent interpapil-lary resections, 22 anterior resections, 4 posterior resections, 2 anterior and posterior resections, and 6 patients reduction of left ventricular volume with endocavitary patches. Results: All the techniques used improved left ventricular function. Analysis of mortality revealed that extensive resections (interpapillary, anterior, and posterior resection) had a 43% mortality. However, a limited resection or a ventricular reconstruction with an endocavitary patch had only a 12.5% mortality. When we changed our approach to a more conservative one, mortality was reduced from 26% the first 12 months to 13% in the last 15 months of the study. Conclusions: Ischemic cardiomyopathy has a poor prognosis if the end-systolic volume index exceeds 100 mL/m2. Various procedures exist to reduce left ventricular volume. Extensive ventricular resections improve ventricular function, but have a high mortality. This led us to use other methods of ventricular volume reduction such as more conservative resections combined with left ventricular reconstructions or ventricular volume reduction with endocavitary patches. Mortality was reduced significantly by this approach. The patients that survived have remained Class I-II in a follow-up that extends up to 30 months. Surgical therapy of Class III-IV ischemic cardiomyopathy is feasible, but aggressive ventricular resections have a high mortality. We advocate a more reconstructive approach with limited or no ventricular resection.
Nonplanar VLSI Device Analysis Using the Solution of Poisson's Equation

Techniques are presented for calculating the drain current of small-geometry MOSFET's in the linear, subthreshold, and punch-through regions of device operation. The current calculation depends only on the electrostatic solution of the two-dimensional Poisson equation in the device. The accuracy of the techniques is established by comparisons with full two-dimensional simulations based on the simultaneous solution of the Poisson and minority-carrier current-continuity equations. The results of simulation also agree well with measurements on MOSFET's having submicrometer effective channel lengths. The application of the simulations to nonplanar technologies is illustrated by the analysis of a taper-isolated dynamic-gain RAM cell. A description is given of simple numerical techniques for solving Poisson's equation in the presence of nonplanar boundaries. The solution method demonstrates good convergence characteristics and minimizes computer storage requirements. Consequently, the simulation capabilities have been successfully implemented on a desktop calculator (Hewlett-Packard 9845) and on minicomputers (Hewlett-Packard 2100 and 1000-F).
Penumbral Fine Structure and Driving Mechanisms of Large-scale Flows in Simulated Sunspots

We analyze in detail the penumbral structure found in a recent radiative magnetohydrodynamic simulation. Near τ = 1, the simulation produces penumbral fine structure consistent with the observationally inferred interlocking comb structure. Fast outflows exceeding 8 km s–1 are present along almost horizontal stretches of the magnetic field; in the outer half of the penumbra, we see opposite polarity flux indicating flux returning beneath the surface. The bulk of the penumbral brightness is maintained by small-scale motions turning over on scales shorter than the length of a typical penumbral filament. The resulting vertical rms velocity at τ = 1 is about half of that found in the quiet Sun. Radial outflows in the sunspot penumbra have two components. In the uppermost few 100 km, fast outflows are driven primarily through the horizontal component of the Lorentz force, which is confined to narrow boundary layers beneath τ = 1, while the contribution from horizontal pressure gradients is reduced in comparison to granulation as a consequence of anisotropy. The resulting Evershed flow reaches its peak velocity near τ = 1 and falls off rapidly with height. Outflows present in deeper layers result primarily from a preferred ring-like alignment of convection cells surrounding the sunspot. These flows reach amplitudes of about 50% of the convective rms velocity rather independent of depth. A preference for the outflow results from a combination of Lorentz force and pressure driving. While the Evershed flow dominates by velocity amplitude, most of the mass flux is present in deeper layers and likely related to a large-scale moat flow.
A Convenient Method for the Conversion of α-Tetralones to Aryl Acetates

Abstract A facile synthesis of aryl acetates from α-tetralone has been performed with isopropenyl acetate and p-toluenesulfonic acid, followed by dehydrogenation with air or DDQ, in a one-pot procedure.
Clinical review: Balancing the therapeutic, safety, and economic issues underlying effective antipseudomonal carbapenem use

Antipseudomonal carbapenems have played a useful role in our antimicrobial armamentarium for 20 years. However, a review of their use during that period creates concern that their clinical effectiveness is critically dependent on attainment of an appropriate dosing range. Unfortunately, adequate carbapenem dosing is missed for many reasons, including benefit/risk misconceptions, a narrow therapeutic window for imipenem and meropenem (due to an increased rate of seizures at higher doses), increasingly resistant pathogens requiring higher doses than are typically given, and cost containment issues that may limit their use. To improve the use of carbapenems, several initiatives should be considered: increase awareness about appropriate treatment with carbapenems across hospital departments; determine optimal dosing regimens for settings where multidrug resistant organisms are more likely encountered; use of, or combination with, an alternative antimicrobial agent having more favorable pharmacokinetic, pharmacodynamic, or adverse event profile; and administer a newer carbapenem with lower propensity for resistance development (for example, reduced expression of efflux pumps or greater stability against carbapenemases).
Towards "intelligent compression" in streams: a biased reservoir sampling based Bloom filter approach

With the explosion of information stored world-wide, data intensive computing has emerged as a central area of research. Efficient management and processing of this massively exponential amount of data from diverse sources, such as telecommunication call data records, telescope imagery, online transaction records, web pages, stock markets, medical records (monitoring critical health conditions of patients), climate warning systems, etc., has become a necessity. Removing redundancy from such huge (multi-billion records) datasets results in resource and compute efficiency for downstream processing and constitutes an important area of study. "Intelligent compression" or deduplication in streaming scenarios, for precise identification and elimination of duplicates from the unbounded data stream is a greater challenge given the real-time nature of data arrival. Stable Bloom Filters (SBF) [13] address this problem to a certain extent. However, SBF suffers from a high false negative rate and slow convergence rate, thereby rendering it inefficient for applications with low false negative rate tolerance.In this paper, we present a novel reservoir sampling based Bloom filter (RSBF) technique, based on the combined concepts of reservoir sampling and Bloom filters for approximate detection of duplicates in data streams. Using detailed theoretical analysis we prove analytical bounds on its false positive rate, false negative rate and convergence rates with low memory requirements. We show that RSBF outperforms SBF in terms of false negative rates and convergence rates while consuming the same amount of memory. Using empirical analysis on real-world datasets (3 million records) and synthetic datasets with around 1 billion records, we demonstrate upto 2× improvement in false negative rate with better convergence rates as compared to SBF, while maintaining comparable false positive rates. To the best of our knowledge, this is the first attempt to integrate reservoir sampling method with Bloom filters for deduplication in streaming scenarios.