cssi/SciSciGPT-SciSciNet huggingface dataset:
The radial-azimuthal stability of accretion disks - Gas pressure contributions

A radial-azimuthal stability analysis of a thin, alpha disk accretion flow is presented. The proportion of radiation pressure, Pr, of the unperturbed flow is allowed to vary according to the parameter beta = Pr/P, where P is the total pressure. As is the case for a purely radial analysis, the disk is stable for beta equal to or less than 0.6. However, the coupling of radial and azimuthal perturbations eliminates the viscous instability for such nonradial modes for all values of beta. The group velocity of the retrograde thermal mode is calculated as a function of beta.
Fabrication, Microstructural Characterization, and Mechanical Properties of Polycrystalline t'-Zirconia

Large-grained (100- to 200-μm), yttria-doped, polycrystalline t'-zirconia ceramics were fabricated by heat-treating presintered samples at temperatures 2100°C. Polarized light microscopy revealed the ferroelastic domain structure in the t' samples. XRD showed that no monoclinic phase was detected on as-polished, ground and fracture surfaces, or on surfaces while under a tensile stress as high as 400 MPa. By contrast, relative changes occurred in the tetragonal peak intensities, which were attributed to ferroelasatic domain switching. The higher toughness of 3-mol%-Y2O3-doped t' samples (7.7 MPa · m1/2) compared to that of 8 mol% Y2O3 cubic samples (2.4 MPa · m1/2) was explained in part by ferroelastic domain switching.
Risk preference and stability under learning

We consider a simple market environment in which traders with finite memory update forecasting rules at random intervals by OLS. In this context, changes in the perception of market risk can trigger volatility and bubbles. Consequently, higher degrees of risk response among traders can have a destabilizing effect on price dynamics. We consider the interaction of this effect with memory, the speed of learning, and the nature of the forecasting rules.
The halo occupation distribution of active galactic nuclei

Using a fully cosmological hydrodynamic simulation that self-consistently incorporates the growth and feedback of supermassive black holes and the physics of galaxy formation, we examine the effects of environmental factors (e.g., local gas density, black hole feedback) on the halo occupation distribution of low luminosity active galactic nuclei (AGN). We decompose the mean occupation function into central and satellite contribution and compute the conditional luminosity functions (CLF). The CLF of the central AGN follows a log-normal distribution with the mean increasing and scatter decreasing with increasing redshifts. We analyze the light curves of individual AGN and show that the peak luminosity of the AGN has a tighter correlation with halo mass compared to instantaneous luminosity. We also compute the CLF of satellite AGN at a given central AGN luminosity. We do not see any significant correlation between the number of satellites with the luminosity of the central AGN at a fixed halo mass. We also show that for a sample of AGN with luminosity above 10 42 ergs/s the mean occupation function can be modeled as a softened step function for central AGN and a power law for the satellite population. The radial distribution of AGN inside halos follows a power law at all redshifts with a mean index of 2.33 ± 0.08. Incorporating the environmental dependence of supermassive black hole accretion and feedback, our formalism provides a theoretical tool for interpreting current and future measurements of AGN clustering.
Ready oxidation of halides to aldehydes using trimethylamine N-oxide in dimethylsulfoxide

Abstract The combination of anhydrous trimethylamine N-oxide in dimethylsulfoxide rapidly oxidizes a variety of alkyl and allylic halides to aldehydes in very good yield at or below room temperature.
A Monte Carlo sampling plan for estimating network reliability

For an undirected network G = V, E whose arcs are subject to random failure, we present a relatively complete and comprehensive description of a general class of Monte Carlo sampling plans for estimating g = gs, T, the probability that a specified node s is connected to all nodes in a node set T. We also provide procedures for implementing these plans. Each plan uses known lower and upper bounds [B, A] on g to produce an estimator of g that has a smaller variance A-gg-B/K on K independent replications than that obtained for crude Monte Carlo sampling B = 0, A = 1. We describe worst-case bounds on sample sizes K, in terms of B and A, for meeting absolute and relative error criteria. We also give the worst-case bound on the amount of variance reduction that can be expected when compared with crude Monte Carlo sampling. Two plans arc studied in detail for the case T = {t}. An example illustrates the variance reductions achievable with these plans. We also show how to assess the credibility that a specified error criterion for g is met as the Monte Carlo experiment progresses, and show how confidence intervals can be computed for g. Lastly, we summarize the steps needed to implement the proposed technique.
Failure-free genetic algorithm optimization of a system controller using SAFE/LEARNING controllers in tandem

The paper presents a method for failure-free genetic algorithm optimization of a system controller. Genetic algorithms present a powerful tool that facilitates producing near-optimal system controllers. Applied to such methods of computational intelligence as neural networks or fuzzy logic, these methods are capable of combining the non-linear mapping capabilities of the latter with learning the system's behavior directly, that is, without a prior model. At the same time, genetic algorithms routinely produce solutions that lead to the failure of the controlled system. Such solutions are generally unacceptable for applications where safe operation must be guaranteed. We present here a method of design, which allows failure-free application of genetic algorithms through utilization of SAFE and LEARNING controllers in tandem, where the SAFE controller recovers the system from dangerous states while the LEARNING controller learns its behavior. The method has been validated by applying it to an inherently unstable system, an inverted pendulum.
Features of propagation of light in the linear array of dielectric spheres

A finite length linear chain of dielectric loss-less identical spheres is considered. A propagation of dipole radiation in the chain of particles induced by the point dipole source placed near one end of the chain is investigated. It is found that at sufficiently large refractive index there exist frequency pass bands around every low frequency Mie resonance. In particular, if the dipole oscillates across the chain axis, one can reveal a longitudinal mode frequency pass band if refractive index nr of the spheres exceeds 1.9. Then, if the dipole oscillates transversely to the chain axis, the transverse frequencies pass bands show up depending on the chain length. In this case, the pass band is formed if the length chain is large enough. Three dielectric materials with nr = 1.9, nr = 2.7, nr = 3.5 are considered what corresponds to ZnO, TiO2, GaAs. It is found that the top of the frequency pass band corresponds to the top of the Brillouin band edge in the quasi-momentum space. On the order hand, the bottom of the frequency pass band corresponds to the guiding wave criterion [2, 3]. This explains the remarkable feature of the band picture established for infinite chain in Ref. [1]: the band structure breaks down as the wavevector becomes small enough. The multisphere Mie scattering formalism is used to calculate how the amplitude of the radiation changes along the chain.
On the Absence of Gravitational Lensing of the Cosmic Microwave Background

The magnification of distant sources by mass clumps at lower (z ≤ 1) redshifts is calculated analytically. The clumps are initially assumed to be galaxy group isothermal spheres with properties inferred from an extensive survey. The average effect, which includes strong lensing, is exactly counteracted by the beam divergence in between clumps (more precisely, the average reciprocal magnification cancels the inverse Dyer-Roeder demagnification). This conclusion is independent of the matter density function within each clump, and remains valid for arbitrary values of Ωm and ΩΛ. When tested against the cosmic microwave background data, a rather large lensing-induced dispersion in the angular size of the primary acoustic peaks of the temperature-temperature (TT) power spectrum is inconsistent with WMAP observations. The situation is unchanged by the use of Navarro-Frenk-White (NFW) profiles for the density distribution of groups, which lead in fact to slightly larger fluctuations. Finally, our formulae are applied to an ensemble of NFW mass clumps or isothermal spheres having the properties of galaxy clusters. The acoustic peak size dispersion remains unobservably large and is also excluded by WMAP. For galaxy groups, two possible ways of reconciling with the data are proposed, both exploiting maximally the uncertainties in our knowledge of group properties. The same escape routes are not available in the case of clusters, however, because their properties are well understood. Here we have a more robust conclusion: neither the NFW nor isothermal sphere profiles are accurate descriptions of clusters, or important elements of physics responsible for shaping zero-curvature space are missing from the standard cosmological model. When all the effects are accrued, it is difficult to understand how WMAP could reveal no evidence whatsoever of lensing by groups and clusters.
Gain and lasing of optically pumped metastable rare gas atoms

Optically pumped alkali vapor lasers are currently being developed in several laboratories. The objective is to construct high-powered lasers that also exhibit excellent beam quality. Considerable progress has been made, but there are technical challenges associated with the reactivity of the metal atoms. Rare gas atoms (Rg) excited to the np5(n+1)sP23 configuration are metastable and have spectral properties that are closely similar to those of the alkali metals. In principle, optically pumped lasers could be constructed using excitation of the np5(n+1)p←np5(n+1)s transitions. We have demonstrated this potential by observing gain and lasing for optically pumped Ar*, Kr* and Xe*. Three-level lasing schemes were used, with He or Ar as the collisional energy transfer agent that established the population inversion. These laser systems have the advantage of using inert reagents that are gases at room temperature.
The Effects of Repeater Hard-Limiting, Filter Distortion, and Noise on a Pseudo-Noise, Time-Of-Arrival Estimation System

Employment of a repeater in a communication system may lead to the introduction of several sources of potential performance degradation. They are hard-limiting, IF filter group delay distrotion and center frequency offset, and additional noise in the links from transmitter-to-repeater and repeater-to-receiver. Specifically, the hardlimiter and IF filter may introduce signal waveform distortion while the former may also introduce signal-to-noise ratio suppression. In this paper the impact of the above on a pseudo-noise (PN) time-of-arrival (TOA) estimation system is considered. The assumed modulation scheme is differential phase shift keying (DPSK) and realistic nonconstant envelope signals are considered; the performance criterion is TOA estimate standard deviation. One surprising result is that the presence ot the limiter tends to degrade performance; this is contrary to corresponding results that have been derived for data detection. It was also found that performance degrades quite gradually with increasing IF filter differential group delay over the signal bandwidth. Finally, although analytical results presented here pertain specifically to the hard-limiter, they may be straightforwardly extended to determine the effects of repeater n th law devices.
A solution for the Tunguska event

This letter presents a new solution for the Tunguska event of June 30th, 1908. The solution has been obtained starting from seismic data, is in fair agreement with the observational evidence, and supports the asteroidal hypothesis for the origin of the Tunguska cosmic body. It is based on an improved model of the hypersonic flow around a small asteroid in the Earth's atmosphere.
Safe Exploration in Markov Decision Processes

In environments with uncertain dynamics exploration is necessary to learn how to perform well. Existing reinforcement learning algorithms provide strong exploration guarantees, but they tend to rely on an ergodicity assumption. The essence of ergodicity is that any state is eventually reachable from any other state by following a suitable policy. This assumption allows for exploration algorithms that operate by simply favoring states that have rarely been visited before. For most physical systems this assumption is impractical as the systems would break before any reasonable exploration has taken place, i.e., most physical systems don't satisfy the ergodicity assumption. In this paper we address the need for safe exploration methods in Markov decision processes. We first propose a general formulation of safety through ergodicity. We show that imposing safety by restricting attention to the resulting set of guaranteed safe policies is NP-hard. We then present an efficient algorithm for guaranteed safe, but potentially suboptimal, exploration. At the core is an optimization formulation in which the constraints restrict attention to a subset of the guaranteed safe policies and the objective favors exploration policies. Our framework is compatible with the majority of previously proposed exploration methods, which rely on an exploration bonus. Our experiments, which include a Martian terrain exploration problem, show that our method is able to explore better than classical exploration methods.
An Event-Driven Approach for Studying Gene Block Evolution in Bacteria

Motivation: Gene blocks are genes co-located on the chromosome. In many cases, gene blocks are conserved between bacterial species, sometimes as operons, when genes are co-transcribed. The conservation is rarely absolute: gene loss, gain, duplication, block splitting and block fusion are frequently observed. An open question in bacterial molecular evolution is that of the formation and breakup of gene blocks, for which several models have been proposed. These models, however, are not generally applicable to all types of gene blocks, and consequently cannot be used to broadly compare and study gene block evolution. To address this problem, we introduce an event-based method for tracking gene block evolution in bacteria. Results: We show here that the evolution of gene blocks in proteobacteria can be described by a small set of events. Those include the insertion of genes into, or the splitting of genes out of a gene block, gene loss, and gene duplication. We show how the event-based method of gene block evolution allows us to determine the evolutionary rateand may be used to trace the ancestral states of their formation. We conclude that the event-based method can be used to help us understand the formation of these important bacterial genomic structures. Availability and implementation: The software is available under GPLv3 license on http://github.com/reamdc1/gene_block_evolution.git. Supplementary online material: http://iddo-friedberg.net/operon-evolution Contact: ude.hoimaim@grebdeirf.i Supplementary information: Supplementary data are available at Bioinformatics online.
Why Press Coverage of a Client Influences the Audit Opinion

In this study I use an experiment to examine why auditors are more likely to issue going–concern opinions when the client has been the subject of negative press coverage prior to the date of the audit opinion. I find no evidence that negative press coverage increases auditors’ perceptions of legal liability, as was suggested in the prior literature. I do find, however, that negative press coverage increases auditors’ perception of a client's bankruptcy probability and this, in turn, leads auditors to modify the audit opinion. Because the press coverage presented in this study provides no new information, the results suggest that auditors react too strongly to redundant information. This over–reaction can result in inefficient allocation of audit resources and can have deleterious affects on clients. Accordingly, policy makers, auditors and their clients might be interested in how auditors’ reliance on redundant information can be reduced.
Regiochemical control of the catalytic asymmetric hydroboration of 1,2-diarylalkenes

The hydroboration of stilbenes and related disubstituted alkenes catalysed by QUINAP complexes may proceed with high enantio- and regioselectivity; rhodium and iridium catalysts give the same product regioisomer but opposite enantiomers.
Mortality rates and trends in Massachusetts before 1860.

The study of mortality rates and trends in the United States before 1860 has been rather unsystematic to date. Most scholars have been content to estimate the mortality rate at some point in time and only a few serious efforts have been made to ascertain the long-term trends in mortality. Particularly lacking are efforts to relate estimates of mortality in the seventeenth and eighteenth centuries to those of the nineteenth century. In addition, the few studies that have attempted to discuss long-term trends in American mortality have been forced to rely on estimates of mortality gathered from different sources and based on different techniques of analysis. Unfortunately, almost no efforts have been made to estimate possible biases introduced when comparing mortality data from different types of records.
Vinyl sulfones : Synthetic preparations and medicinal chemistry applications

Vinyl sulfones have long been known for their synthetic utility in organic chemistry, easily participating in 1,4-addition reactions and cycloaddition reactions. This functional group has also recently been shown to potently inhibit a variety of enzymatic processes providing unique properties for drug design and medicinal chemistry. This review includes traditional methods used for the synthesis of vinyl sulfones, but focuses mainly on newer reactions applied to vinyl sulfones, including olefin metathesis, conjugate reduction, asymmetric dihydroxylation (AD), and the use of vinyl sulfones to arrive at highly functionalized targets, all illustrating the rich and versatile chemistry this group can efficiently perform. In addition, geminal disulfones are discussed with respect to their formation, reactions, and medicinal applications of this underutilized functional group.
A hypersurface in C^2 whose stability group is not determined by 2-jets

We give an example of a hypersurface in C 2 through 0 whose stability group at 0 is determined by 3-jets, but not by jets of any lesser order. We also examine some of the properties which the stability group of this infinite type hypersurface shares with the 3-sphere in C 2 .
Distribution-Independent Evolvability of Linear Threshold Functions

Valiant’s model of evolvability models the evolutionary process of acquiring useful functionality as a restricted form of learning from random examples (Valiant, 2009). Linear threshold functions and their various subclasses, such as conjunctions and decision lists, play a fundamental role in learning theory and hence their evolvability has been the primary focus of research on Valiant’s framework. One of the main open problems regarding the model is whether conjunctions are evolvable distribution-independently (Feldman and Valiant, 2008). We show that the answer is negative. Our proof is based on a new combinatorial parameter of a concept class that lower-bounds the complexity of learning from correlations. We contrast the lower bound with a proof that linear threshold functions having a nonnegligible margin on the data points are evolvable distribution-independently via a simple mutation algorithm. Our algorithm relies on a non-linear loss function being used to select the hypotheses instead of 0-1 loss in Valiant’s original denition. The proof of evolvability requires that the loss function satises
Do Low-Quality Products Affect High-Quality Entry? Multiproduct Firms and Nonstop Entry in Airline Markets

This paper studies the effect of product ownership and quality on nonstop entry in the airline industry. Specifically, this paper empirically examines the decision of an airline to offer high quality nonstop service between cities given that the airline may or may not be offering lower quality one-stop service. I find that airlines that offer one-stop service through a hub are less likely to enter that same market with nonstop service than those that do not. In addition, the quality of the one-stop service is an important determinant of entry. Airlines are more likely to enter a market with nonstop service if their own or their rival's one-stop service in the market are of lower quality. Estimates suggest that the entry of a rival nonstop carrier diminishes the probability a carrier enters the market with nonstop service. However, airlines offering one-stop service respond differently to nonstop rivals. In particular, relative to other carriers, those offering one-stop service are more likely to enter markets if there are nonstop rivals, suggesting that cannibalization effects are diminished in the presence of nonstop competition.
Caffe: Convolutional Architecture for Fast Feature Embedding

Caffe provides multimedia scientists and practitioners with a clean and modifiable framework for state-of-the-art deep learning algorithms and a collection of reference models. The framework is a BSD-licensed C++ library with Python and MATLAB bindings for training and deploying general-purpose convolutional neural networks and other deep models efficiently on commodity architectures. Caffe fits industry and internet-scale media needs by CUDA GPU computation, processing over 40 million images a day on a single K40 or Titan GPU (approx 2 ms per image). By separating model representation from actual implementation, Caffe allows experimentation and seamless switching among platforms for ease of development and deployment from prototyping machines to cloud environments.Caffe is maintained and developed by the Berkeley Vision and Learning Center (BVLC) with the help of an active community of contributors on GitHub. It powers ongoing research projects, large-scale industrial applications, and startup prototypes in vision, speech, and multimedia.
Electron velocity distribution instability in magnetized plasma wakes and artificial electron mass

[1] The wake behind a large object (such as the moon) moving rapidly through a plasma (such as the solar wind) contains a region of depleted density, into which the plasma expands along the magnetic field, transverse to the flow. It is shown here that (in addition to any ion instability) a bump-on-tail which is unstable appears on the electrons' parallel velocity distribution function because of the convective non-conservation of parallel energy (drift-energization). It arises regardless of any non-thermal features on the external electron velocity distribution. The detailed electron distribution function throughout the wake is calculated by integration along orbits; and the substantial energy level of resulting electron plasma (Langmuir) turbulence is evaluated quasi-linearly. It peaks near the wake axis. If the mass of the electrons is artificially enhanced, for example in order to make numerical simulation feasible, then much more unstable electron distributions arise; but these are caused by the unphysical mass ratio.
Z/E stereoselective synthesis of β-bromo baylis-hillman ketones using MgBr2 as promoter via a one-pot three-component reaction

Abstract The first time steroselective synthesis of ( Z )-β-bromo Baylis–Hillman ketones has been achieved using a one-pot three-component reaction. The new system uses MgBr 2 as both the Lewis acidic promoter and the bromine source for the Michael-type addition with α,β-acetylenic ketones to form an active β-bromo allenolate intermediate, which in turn attacks various aldehydes to afford β-bromo Baylis–Hillman adducts in good yields and Z -selectivity.
Toward a general theory of linking invariants

Let N1,N2,M be smooth manifolds with dimN1 + dimN2 + 1 = dimM and leti, for i = 1,2, be smooth mappings of Ni to M where Im�1 ∩ Im�2 = ∅. The classical linking number lk(�1,�2) is defined only when �1∗(N1) = �2∗(N2) = 0 ∈ H∗(M). The affine linking invariant alk is a generalization of lk to the case where �1∗(N1) or �2∗(N2) are not zero-homologous. In (7) we constructed the first examples of affine linking invariants of nonzero-homologous spheres in the spherical tangent bundle of a manifold, and showed that alk is intimately related to the causality relation of wave fronts on manifolds. In this paper we develop the general theory. The invariant alk appears to be a universal Vassiliev-Goussarov invariant of order ≤ 1. In the case where �1∗(N1) = �2∗(N2) = 0 ∈ H∗(M), it is a splitting of the classical linking number into a collection of independent invariants. To construct alk we introduce a new pairing µ on the bordism groups of spaces of mappings of N1 and N2 into M, not necessarily under the restriction dimN1+dimN2+ 1 = dimM. For the zero-dimensional bordism groups, µ can be related to the Hatcher- Quinn invariant. In the case N1 = N2 = S 1 , it is related to the Chas-Sullivan string homology super Lie bracket, and to the Goldman Lie bracket of free loops on surfaces. AMS Classification numbers Primary: 57R19 Secondary: 14M07, 53Z05, 55N22, 55N45, 57M27, 57R40, 57R45, 57R52
Origination Channel, Prepayment Penalties and Default

This paper presents evidence that non-bank-originated subprime mortgages have a higher probability of default than bank-originated subprime mortgages, but only for loans with prepayment penalties. Evidence also indicates that non-banks price prepayment penalties less favorably to borrowers than banks do, and non-banks originate disproportionately more loans with prepayment penalties in locales with less financially sophisticated borrowers. State anti-predatory lending law provisions restricting the use of prepayment penalties eliminate the elevated default risk of non-bank originations relative to bank originations. These findings are consistent with incentives generated by non-bank compensation via yield spread premiums on loans with prepayment penalties.
Quasi-Steady State Natural Convection in Laser Chemical Vapor Deposition With a Moving Laser Beam

Numerical analysis of laser chemical vapor deposition (LCVD) of titanium nitride by a moving laser beam is presented. The effect of natural convection due to temperature and concentration differences in the gaseous mixture is modeled and implemented into thermal model of LCVD by a moving laser beam. The problem is formulated in a coordinate system that moves with the laser beam and therefore, the problem is a quasi-steady state problem. The results show that the effect of natural convection on the shape of deposited film is very insignificant for cases with a laser power of 300 W but becomes important when the laser power is increased to 360 W.
Forced Response Analysis of an Aerodynamically Detuned Supersonic Turbomachine Rotor

Analyse de la reponse forcee d'un rotor de turbomachine en regime supersonique avec une desynchronisation aerodynamique
Staging transformations for multimodal web interaction management

Multimodal interfaces are becoming increasingly ubiquitous with the advent of mobile devices, accessibility considerations, and novel software technologies that combine diverse interaction media. In addition to improving access and delivery capabilities, such interfaces enable flexible and personalized dialogs with websites, much like a conversation between humans. In this paper, we present a software framework for multimodal web interaction management that supports mixed-initiative dialogs between users and websites. A mixed-initiative dialog is one where the user and the website take turns changing the flow of interaction. The framework supports the functional specification and realization of such dialogs using staging transformations -- a theory for representing and reasoning about dialogs based on partial input. It supports multiple interaction interfaces, and offers sessioning, caching, and co-ordination functions through the use of an interaction manager. Two case studies are presented to illustrate the promise of this approach.
An implicit discontinuous Galerkin method for the unsteady compressible Navier–Stokes equations

Abstract A high-order implicit discontinuous Galerkin method is developed for the time-accurate solutions to the compressible Navier–Stokes equations. The spatial discretization is carried out using a high order discontinuous Galerkin method, where polynomial solutions are represented using a Taylor basis. A second order implicit method is applied for temporal discretization to the resulting ordinary differential equations. The resulting non-linear system of equations is solved at each time step using a pseudo-time marching approach. A newly developed fast, p -multigrid is then used to obtain the steady state solution to the pseudo-time system. The developed method is applied to compute a variety of unsteady subsonic viscous flow problems. The numerical results obtained indicate that the use of this implicit method leads to significant improvements in performance over its explicit counterpart, while without significant increase in memory requirements.
Leveled commitment contracts with myopic and strategic agents

Abstract In automated negotiation systems consisting of self-interested agents, contracts have traditionally been binding, i.e., impossible to breach. Such contracts do not allow the agents to efficiently deal with future events. This deficiency can be tackled by using a leveled commitment contracting protocol which allows the agents to decommit from contracts by paying a monetary penalty to the contracting partner. The efficiency of such protocols depends heavily on how the penalties are decided. In this paper, different leveled commitment protocols and their parameterizations are experimentally compared in sequences of multiple contracts. In the different experiments, the agents are of different types: self-interested or social welfare maximizing, and they can carry out game-theoretic lookahead or be myopic. Several meeting technologies, ways of setting the contract price, and ways of setting and increasing the penalties are compared. Surprisingly, self-interested myopic agents reach a higher social welfare quicker than cooperative myopic agents when decommitment penalties are low. The social welfare in settings with agents that perform lookahead does not vary as much with the decommitment penalty as the social welfare in settings that consist of myopic agents. In all of the settings, the best way to set the decommitment penalties is to choose low penalties, but ones that are greater than zero. This indicates that leveled commitment contracting protocols outperform both full commitment protocols and commitment free protocols. 1
Western Views Toward Muslims: Evidence from a 2006 Cross-National Survey

Concerns about Islamic extremism and ongoing debates about the integration and assimilation of Muslims into Western societies continue to attract considerable attention from the media, policymakers, and scholars, but relatively little cross-national research has been done on Western attitudes toward Muslims. This article attempts to address this question by exploring 2006 Pew Global Attitudes data among non-Muslims in Britain, France, Germany, Spain, and the U.S. Using structural equation modeling, we examine the determinants of Western views toward Muslims, and find that threat perceptions are the primary factor influencing these views. Specifically, our analysis suggests that perceptions of security threats drive attitudes regarding Muslims, and that perceived cultural threats are only indirectly related to views towards Muslims.
Determining the closest stable polynomial to an unstable one

The problem of being given a polynomial whose zeros do not all lie on or inside the unit circle and finding the closest polynomial whose zeros are all on or inside the unit circle is considered. The measure of closeness used is the weighted Euclidean distance in coefficient space. The algorithm can be extended to other measures of closeness as well. Because the direct minimization on the coefficient space is difficult, the problem is approached in Schur coefficient space. In this way, the stability condition is easily guaranteed. A very efficient algorithm for obtaining the optimum solution is developed. >
Estimation of modeled object pose from monocular images

The use of one or more monocular images to estimate the three-dimensional position of objects is investigated. The identities of the objects are known, and geometric models are assumed to be available. Linear features extracted from sensor data are interpreted as corresponding with model features by search of an interpretation tree built using prior position estimates. Object positions are updated by maximum-likelihood estimation. Position estimation results from an implemented system are presented, demonstrating the location of partially occluded objects in a cluttered scene. >
The Impact of Fertilizer Subsidies on National Fertilizer Use: An Example from Malawi

This paper examines the impact of government funded fertilizer subsidies on national level fertilizer use. We use panel data to investigate how the 2006/07 fertilizer subsidy program in Malawi impacted farmer decisions to purchase commercial fertilizer. Using a fixed effects estimator to control for time invariant unobservables, we find that when farmers’ ability to acquire subsidized fertilizer is treated as exogenous, it has a significant negative impact on commercial fertilizer purchases but the coefficient is small. We also find that wealth and social networks have a significantly positive impact on who receives subsidized fertilizer. We then use instrumental variables (IV) to control for the endogeneity of subsidized fertilizer acquisition affecting commercial purchases. Using this IV fixed effects estimator demonstrates that when we control for the endogeneity of subsidized fertilizer, it again has a significant negative impact on commercial purchases. However the coefficient on subsidized fertilizer is ten times greater when using IV to control for endogeneity than when subsidized fertilizer is treated as exogenous. These findings indicate that policy makers must be aware of potential displacement of commercial sales when they introduce an input subsidy program. Furthermore, government programs should be designed to target households without effective demand in order to ensure that fertilizer subsidy programs maximize their impact on total fertilizer use and hence contribute to their cost-effectiveness.
The Close Binary Properties of Massive Stars in the Milky Way and Low-Metallicity Magellanic Clouds

In order to understand the rates and properties of Type Ia and Type Ib/c supernovae, X-ray binaries, gravitational wave sources, and gamma-ray bursts as a function of galactic environment and cosmic age, it is imperative that we measure how the close binary properties of O- and B-type stars vary with metallicity. We have studied eclipsing binaries with early B main-sequence primaries in three galaxies with different metallicities: the Large and Small Magellanic Clouds (LMC and SMC, respectively) and the Milky Way (MW). The observed fractions of early B stars that exhibit deep eclipses 0.25 0.1, (2) an intrinsic orbital period distribution slightly skewed toward shorter periods relative to a distribution that is uniform in log P, (3) a mass-ratio distribution weighted toward low-mass companions, and (4) a small, nearly negligible excess fraction of twins with q > 0.9. Our fitted parameters derived for the MW eclipsing binaries match the properties inferred from nearby, early-type spectroscopic binaries, which further validates our results. There are no statistically significant trends with metallicity, demonstrating that the close binary properties of massive stars do not vary across metallicities –0.7 < log(Z/Z ☉) < 0.0 beyond the measured uncertainties.
Design study of 2-in-1 large-aperture ir dipole (D2) for the LHC luminosity upgrade

This paper analyses possible D2 magnet designs for the "dipole-first" option of the LHC luminosity upgrade based on Nb3Sn superconductor and compares them in terms of the maximum field, field quality, and Lorentz forces in the coils.
Adaptive server selection for large scale interactive online games

Large scale interactive online games aim to support a very large number of game players simultaneously. To support hundreds of thousands of concurrent players, game providers have so far focused on developing highly scalable game server architectures and extensible network infrastructures. Recently, distributed online games are beginning to incorporate more interactive features and action sequences; thus, it becomes increasingly important to provision server resources in an efficient manner to support real-time interaction between the users. In this paper, we present a novel distributed algorithm to select game servers for a group of clients participating in a large scale interactive online game session. The goal of server selection is to minimize the server resource usage while satisfying a real-time delay constraint. We develop a synchronization delay model for interactive games and formulate the server selection problem, and prove that the considered problem is NP-hard. The proposed algorithm, called zoom-in-zoom-out, is adaptive to session dynamics (e.g., clients join) and lets the clients select appropriate servers in a distributed manner such that the server resource is efficiently utilized. Using simulation, we study the performance of the proposed algorithm and show that it is simple, yet effective in achieving its design goal. In particular, we show that the performance of our algorithm is comparable to, or sometimes even better than, that of centralized greedy algorithms, which require global information and extensive computations.
Connecting multiple-unicast and network error correction: Reduction and unachievability

We show that solving a multiple-unicast network coding problem can be reduced to solving a single-unicast network error correction problem, where an adversary may jam at most a single edge in the network. Specifically, we present an efficient reduction that maps a multiple-unicast network coding instance to a network error correction instance while preserving feasibility. The reduction holds for both the zero probability of error model and the vanishing probability of error model. Previous reductions are restricted to the zero-error case. As an application of the reduction, we present a constructive example showing that the single-unicast network error correction capacity may not be achievable, a result of separate interest.
Boundary rigidity and stability for generic simple metrics

Let (M, g) be a Riemannian manifold with boundary. Denote by pg the distance function in the metric g. We consider the inverse problem of whether pg(x,y), known for all x, y on <9M, determines the metric uniquely. This problem arose in geophysics in an attempt to determine the inner structure of the Earth by measuring the travel times of seismic waves. It goes back to Herglotz [H] and Wiechert and Zoeppritz [WZ]. Although the emphasis has been in the case that the medium is isotropic, the anisotropic case has been of interest in geophysics since it has been found that the inner core of the Earth exhibits anisotropic behavior [Cr]. In differential geometry this inverse problem has been studied because of rigidity questions and is known as the boundary rigidity problem. It is clear that one cannot determine the metric uniquely. Any isometry which is the identity at the boundary will give rise to the same measurements. Furthermore, the boundary distance function only takes into account the shortest paths, and it is easy to find counterexamples to unique determination, so one needs to pose some restrictions on the metric. Michel [Mi] conjectured that a simple metric g is uniquely determined, up to an action of a diffeomorphism fixing the boundary, by the boundary distance function pg(x,y) known for all x and y on dM. We recall Definition 1.1. We say that the Riemannian metric g is simple in M, if dM is strictly convex w.r.t. g, and for any x G M, the exponential map exp^ : exp~1(M) ? M is a diffeomorphism.
Optimizing scrip systems: efficiency, crashes, hoarders, and altruists

We discuss the design of efficient scrip systems and develop tools for empirically analyzing them. For those interested in the empirical study of scrip systems, we demonstrate how characteristics of agents in a system can be inferred from the equilibrium distribution of money. From the perspective of a system designer, we examine the effect of the money supply on social welfare and show that social welfare is maximizedby increasing the money supply up to the point that the system experiences a "monetary crash," where money is sufficiently devalued that no agent is willing to perform a service. We alsoexamine the implications of the presence of altruists and hoarders on the performance of the system. While a small number of altruists may improve social welfare, too many can also cause the system to experience a monetary crash, which may be bad for social welfare. Hoarders generally decrease social welfare but, surprisingly, they also promote system stability by helping prevent monetary crashes. In addition, we provide new technical tools for analyzing and computing equilibria by showing that our model exhibits strategic complementarities, which implies that there exist equilibria in pure strategies that can be computed efficiently.
Tris (Trimethylsilyl)silane in the Deoxygenation of Long Chain Unsaturated Alcohols Converts Cis to Trans Isomers

Abstract During radical deoxygenation reactions tris (trimethylsilyl)silane can cause cis to trans isomerization and reduction of remote double bonds in contrast to tributyltin hydride.
Accounting earnings and cash flows as measures of firm performance: The role of accounting accruals

Abstract This paper investigates circumstances under which accruals are predicted to improve earnings' ability to measure firm performance, as reflected in stock returns. The importance of accruals is hypothesized to increase (i) the shorter the performance measurement interval, (ii) the greater the volatility of the firm's working capital requirements and investment and financing activities, and (iii) the longer the firm's operating cycle. Under each of these circumstances, cash flows are predicted to suffer more severely from timing and matching problems that reduce their ability to reflect firm performance. The results of empirical tests are consistent with these predictions.
Convex Relaxation of Optimal Power Flow—Part II: Exactness

This tutorial summarizes recent advances in the convex relaxation of the optimal power flow (OPF) problem, focusing on structural properties rather than algorithms. Part I presents two power flow models, formulates OPF and their relaxations in each model, and proves equivalence relations among them. Part II presents sufficient conditions under which the convex relaxations are exact.
Commentary on the Special Issue: The Emergence of a Field

The 2003 special issue of the Journal of Business Venturing presents research focusing on various aspects of family owned businesses and venture creation. This commentary on the inaugural issue of the journal discusses the importance of family businesses and venture creation as topics in entrepreneurship development and identifies the emerging sub-topics in the field of family entrepreneurship. The articles selected for publication in this special issue are briefly overviewed.(VRS)
Scalable interoperability through the use of COIN lightweight ontology

There are many different kinds of ontologies used for different purposes in modern computing. A continuum exists from lightweight ontologies to formal ontologies. In this paper we compare and contrast the lightweight ontology and the formal ontology approaches to data interoperability. Both approaches have strengths and weaknesses, but they both lack scalability because of the n2 problem. We present an approach that combines their strengths and avoids their weaknesses. In this approach, the ontology includes only high level concepts; subtle differences in the interpretation of the concepts are captured as context descriptions outside the ontology. The resulting ontology is simple, thus it is easy to create. It also provides a structure for context descriptions. The structure can be exploited to facilitate automatic composition of context mappings. This mechanism leads to a scalable solution to semantic interoperability among disparate data sources and contexts.
Social contagion theory: examining dynamic social networks and human behavior

Here, we review the research we have conducted on social contagion. We describe the methods we have employed (and the assumptions they have entailed) to examine several datasets with complementary strengths and weaknesses, including the Framingham Heart Study, the National Longitudinal Study of Adolescent Health, and other observational and experimental datasets that we and others have collected. We describe the regularities that led us to propose that human social networks may exhibit a ‘three degrees of influence’ property, and we review statistical approaches we have used to characterize interpersonal influence with respect to phenomena as diverse as obesity, smoking, cooperation, and happiness. We do not claim that this work is the final word, but we do believe that it provides some novel, informative, and stimulating evidence regarding social contagion in longitudinally followed networks. Along with other scholars, we are working to develop new methods for identifying causal effects using social network data, and we believe that this area is ripe for statistical development as current methods have known and often unavoidable limitations. Copyright © 2012 John Wiley & Sons, Ltd.
Copper catalyzed coupling of aryl chlorides, bromides and iodides with amines and amides

A copper(I) catalyzed procedure for carbon–nitrogen bond formation utilizing aryl halides and either amines, including amino acids and diphenylamine, or aliphatic and aromatic amides is described.