cssi/SciSciGPT-SciSciNet huggingface dataset:
Dwell time and average local speed in a resonant tunneling structure

Abstract We show that the dwell times and the average local speeds of an electron in a resonant tunneling structure depend sensitively on the matching parameter at the interfaces. We point out that there is a need to carry out microscopic calculations to find out which matching parameter is appropriate for a given structure.
OVERVIEW OF AFFINE QUANTUM GRAVITY

The basic principles of Affine Quantum Gravity are presented in a pedagogical style with a limited number of equations.
Stability and Asymptotic Behavior of Periodic Traveling Wave Solutions of Viscous Conservation Laws in Several Dimensions

Under natural spectral stability assumptions motivated by previous investigations of the associated spectral stability problem, we determine sharp Lp estimates on the linearized solution operator about a multidimensional planar periodic wave of a system of conservation laws with viscosity, yielding linearized L1 ∩ Lp → Lp stability for all \({p \geqq 2}\) and dimensions \({d \geqq 1}\) and nonlinear L1 ∩ Hs → Lp ∩ Hs stability and L2-asymptotic behavior for \({p\geqq 2}\) and \({d\geqq 3}\) . The behavior can in general be rather complicated, involving both convective (that is, wave-like) and diffusive effects.
Early star formation and the evolution of the stellar initial mass function in galaxies

It has frequently been suggested in the literature that the stellar IMF in galaxies was top-heavy at early times. This would be plausible physically if the IMF depended on a mass-scale such as the Jeans mass that was higher at earlier times because of the generally higher temperatures that were present then. In this paper it is suggested, on the basis of current evidence and theory, that the IMF has a universal Salpeter-like form at the upper end, but flattens below a characteristic stellar mass that may vary with time. Much of the evidence that has been attributed to a top-heavy early IMF, including the ubiquitous G-dwarf problem, the high abundance of heavy elements in clusters of galaxies, and the high rate of formation of massive stars in high-redshift galaxies, can be accounted for with such an IMF if the characteristic stellar mass was several times higher during the early stages of galaxy evolution. However, significant variations in the mass-to-light ratios of galaxies and large amounts of dark matter in stellar remnants are not as easily explained in this way, because they require more extreme and less plausible assumptions about the form and variability of the IMF. Metal-free ‘population III’ stars are predicted to have an IMF that consists exclusively of massive stars, and they could help to account for some of the evidence that has been attributed to a top-heavy early IMF, as well as contributing importantly to the energetics and chemical enrichment of the early Universe.
Navier-Stokes computations for oscillating control surfaces

Unsteady Navier-Stokes computations have been performed for simulating transonic flows over wings with oscillating control surfaces using a locally moving grid and a stationary-mismatched zoning scheme. An F-5 wing and a clipped delta wing are chosen for the present study. The computed unsteady pressures and the response characteristics to the control surface motions are compared with experimental data. The results successfully predict main features of the unsteady pressure profiles, such as the double peaks at the shock wave and at the hinge line.
A Theory of Intraperson Games

Abstract A wide variety of theories across disciplines posit the existence of multiple inner preferences (selves, drives, or agents) within each person, whose conflicts must be resolved for a person to reach a decision. Despite their strong validity, these theories have not been incorporated into mainstream management science literature because of their qualitative nature. In this article, the author proposes a theory of intraperson games (TIG) to fill this important gap. Building on social welfare literature and standard (multiperson) game theory, the TIG defines two types of intraperson players, and each has a unique strategy set. The first type, the efficiency agent, attempts to maximize the total utility for the entire set of selves that reside in a person's mind. The second type, the equity agent, strives to balance the utilities that each of these selves receives. The TIG states that an individual decision is the outcome of the strategic interaction between the efficiency agent and the equity agent....
THE RELEVANCE OF PEACE TO STUDIES OF DRUG MARKET VIOLENCE

Goldstein's (1985) concept of systemic violence has contributed substantially to criminological thought and research, but its power can be enhanced by connecting it to a broader typology of social life: the resource exchange—social control typology. That typology connects systemic violence logically with two important yet neglected forms of drug market behavior: peaceful resource exchange and peaceful social control. This article, which is based on 50 in-depth interviews with individuals involved actively or recently in drug selling, describes the various forms of violent and nonviolent resource exchange and social control in illicit drug markets, stating them in quantitative terms that are conceptually distinct and empirically observable. We conclude by discussing 1) the implications of peaceful behavior for a fuller understanding of violence and 2) the relevance of the resource exchange-social control typology to criminological theory and research.
Algebraic group actions on noncommutative spectra

Let G be an affine algebraic group and let R be an associative algebra with a rational action of G by algebra automorphisms. We study the induced G-action on the set Spec R of all prime ideals of R, viewed as a topological space with the Jacobson–Zariski topology, and on the subspace Rat R ⊆ Spec R consisting of all rational ideals of R. Here, a prime ideal P of R is said to be rational if the extended centroid $$ \mathcal{C}\left( {R/P} \right) $$ is equal to the base field. Our results generalize the work of Mœglin and Rentschler and of Vonessen to arbitrary associative algebras while also simplifying some of the earlier proofs. The map P ↦ ⋂g ∈ G g.P gives a surjection from Spec R onto the set G-Spec R of all G-prime ideals of R. The fibers of this map yield the so-called G-stratification of Spec R which has played a central role in the recent investigation of algebraic quantum groups, in particular, in the work of Goodearl and Letzter. We describe the G-strata of Spec R in terms of certain commutative spectra. Furthermore, we show that if a rational ideal P is locally closed in Spec R then the orbit G.P is locally closed in Rat R. This generalizes a standard result on G-varieties. Finally, we discuss the situation where G-Spec R is a finite set.
On Inviscid Limits for the Stochastic Navier–Stokes Equations and Related Models

We study inviscid limits of invariant measures for the 2D stochastic Navier–Stokes equations. As shown by Kuksin (J Stat Phys 115(1–2):469–492, 2004), the noise scaling \({\sqrt{\nu}}\) is the only one which leads to non-trivial limiting measures, which are invariant for the 2D Euler equations. Using a Moser-type iteration for stochastic drift-diffusion equations, we show that any limiting measure \({\mu_{0}}\) is in fact supported on bounded vorticities. Relationships of \({\mu_{0}}\) to the long term dynamics of 2D Euler in \({L^{\infty}}\) with the weak* topology are discussed. We also obtain a drift-independent modulus of continuity for a stationary deterministic model problem, which leads us to conjecture that in fact \({\mu_0}\) is supported on \({C^0}\) . Moreover, in view of the Batchelor–Krainchnan 2D turbulence theory, we consider inviscid limits for a weakly damped stochastic Navier–Stokes equation. In this setting we show that only an order zero noise scaling (with respect to ν) leads to a nontrivial limiting measure in the inviscid limit.
Gamma-Ray Bursts and the Cosmic Star Formation Rate

We have tested several models of gamma-ray burst (GRB) luminosity and redshift distribution functions for compatibility with the BATSE 4B number versus peak flux relation. Our results disagree with recent claims that current GRB observations can be used to constrain strongly the cosmic star formation history. Instead, we find that relaxing the assumption that GRBs are standard candles renders a very broad range of models that are consistent with the BATSE number-flux relation. We explicitly construct two sample distributions, one tracing the star formation history and one with a constant comoving density. We show that both distributions are compatible with the observed fluxes and redshifts of the bursts GRB 970508, GRB 971214, and GRB 980703, and we discuss the measurements required to distinguish the two models.
Interpretation of surface features of Europa obtained from occultations by Io

Abstract Light curves of occultations of Europa by Io have been used to generate a crude map of abledo features on Europa. The best values currently available for the impact parameters and magnitude ratios for each event have been imposed on our model. Residuals between the observed and computed light curves are interpreted as albedo features on Europa. In order to improve the fit between the observations and the model it became necessary to impose a general polar brightening. The effects of additional albedo features and alternate models are discussed.
Cooling rates of group IVA iron meteorites

Cooling rates of six group IVA iron meteorites were estimated by a taenite central Ni concentration-taenite half-width method. Calculated cooling rates range from 13 to 25 C/Myr, with an average of 20 C/Myr. No correlation between cooling rate and bulk Ni content is observed, and the data appear to be consistent with a uniform cooling rate as expected from an igneous core origin. This result differs from previous studies reporting a wide range in cooling rates that were strongly correlated with bulk Ni content. The differences result mainly from differences in the phase diagram and the selected diffusion coefficients. Cooling rates inferred from taenite Ni concentrations at the interface with kamacite are consistent with those based on taenite central Ni content.
Training Optimization for Gauss-Markov Rayleigh Fading Channels

In this paper, pilot-assisted transmission over Gauss-Markov Rayleigh fading channels is considered. A simple scenario, where a single pilot signal is transmitted every T symbols and T - 1 data symbols are transmitted in between the pilots, is studied. First, it is assumed that binary phase-shift keying (BPSK) modulation is employed at the transmitter. With this assumption, the training period, and data and training power allocation are jointly optimized by maximizing an achievable rate expression. Achievable rates and energy-per-bit requirements are computed using the optimal training parameters. Secondly, a capacity lower bound is obtained by considering the error in the estimate as another source of additive Gaussian noise, and the training parameters are optimized by maximizing this lower bound.
A mild and selective C-3 reductive alkylation of indoles

In the presence of triethylsilane and trifluoroacetic acid, the reaction between indoles and aldehydes in dichloromethane at 0°C, results in good yields of C-3 reductively alkylated products. The transformation is most effective for the preparation of 3-(arylmethyl)indoles 6 from aromatic aldehydes.
Uranium(VI) tetraoxido core coordinated by bidentate nitrate.

The synthesis and structural characterization of the compounds K[(UO2)2(UO4)(OH)(NO3)2]H2O (1) and Ba[(UO2)4(UO4)2(OH)2(NO3)4]H2O (2) have revealed that each contains sheets that are based upon the β-U3O8-type topology and that these sheets are linked through low-valence interlayer cations. Consistent with other uranium(VI) compounds that have topologically identical sheets, one of the uranium(VI) sites exhibits a highly unusual (UO4)2− tetraoxido core that is further coordinated by two bidentate (NO3)− groups.
Multimodal image registration based on edges and junctions

This paper proposes an edge-based multimodal image registration approach. It aims to address image registration as a whole rather than tackle each of its elements independently. One-pixel-wide curves are firstly extracted from images, and junctions along the curves are detected. Then, each curve is divided into subsegments as matching primitives. A similarity metric based on the number of matched pairs of subsegments is proposed and experimental results show that the presented approach is a robust and effective tool for multimodal image registration.
Two locations, two times, and the element set

We have delved into that aspect of classical initial orbit determination wherein one transforms two locations at two times into an orbital element set. The particular realm of application we have in mind is artificial satellites whose locations are uncertain to ≃1 km3, the two locations being separated in time by no more than 30 min. Not only have we investigated Gauss's method, iteration on the semi-latus rectum, iteration on the true anomaly, and the Lambert-Euler technique, we have made substantial practical progress with the latter two algorithms. Specifically, we have performed an essential analytical simplification that reduces all these methods to the solution of a single equation in one unknown, instead of the usual coupled triplet of three equations in three unknows. An extensive series of numerical trials shows the robustness of the new formulation and the unsatisfactory nature of the traditional schemes in our application. Because the essence of our advance is analytical in nature, we expect this new approach to be superior in all realms of initial orbit determination.
Natural supersymmetry: LHC, dark matter and ILC searches

Particle physics models with Natural Supersymmetry are characterized by a superpotential parameter μ ∼ m h ∼ 125 GeV, while third generation squarks have mass $ _\sim^< $ 0.5–1.5 TeV. Gluinos should be lighter than several TeV so as not to destabilize the lighter squarks. First and second generation sfermions can be at the tens-of-TeV level which yields a decoupling solution to the SUSY flavor and CP problems. Adopting a top- down approach, we delineate the range of GUT scale SUSY model parameters which leads to a Natural SUSY mass spectrum. We find natural SUSY models to be tightly constrained by the b → sγ branching fraction measurement while it is also difficult but not impossible to accommodate a light Higgs scalar of mass ≃ 125 GeV. We present several benchmark points which are expandable to slopes and planes. Natural SUSY is difficult to see at LHC unless some third generation squarks are very light. The top- and bottom- squarks cascade decay mainly to higgsino-like charginos and neutralinos via numerous possibilities, leading to a rather complex set of signatures. Meanwhile, a linear e + e − collider operating at $ \sqrt {s} $ ∼ 0.25–0.5 TeV would be a higgsino factory and is essentially guaranteed a SUSY discovery of the low-lying charged and neutral higgsino states. Since thermal neutralino cold dark matter is underproduced, we conjecture that the incorporation of a Peccei-Quinn sector or light moduli into the theory will augment higgsino dark matter production, possibly together with an admixture of axions. We present rates for direct and indirect higgsino dark matter detection for the case where light higgsinos dominate the dark matter abundance.
Synthesis and characterization of dehydrothieno[18]annulenes

Use of a palladium/copper alkyne cross-coupling strategy provides access to three tris(thiophene-fused) dodecadehydro[18]annulenes, including examples of both highly symmetrical C3h and unsymmetrical Cs structures.
SmartPark as a virtual STATCOM

Summary form only given. Power electronic-based FACTS devices such as STATCOMs are sometimes essential for voltage support in transmission networks. They can also be used for continuous operation of doubly-fed induction generator-based wind turbines during faults. However, these devices are quite expensive and therefore cannot be used extensively. This paper explores the potential of a low-cost solution that utilizes the reactive power and voltage support capabilities of plug-in vehicles parked in charging stations (SmartParks) so that they can behave as virtual STATCOMs. For this solution, a 12-bus multimachine power system is considered wherein one of the conventional units is replaced by a 400 MW wind farm. Twelve SmartParks are developed and integrated into the test system. First, they are connected to a weak bus in the system and used in voltage control mode. Their performance is compared with a STATCOM of a similar rating. Next, the SmartParks are connected to the wind farm bus, and a coordinated reactive power control strategy is proposed to improve the fault-ride-through capability of the wind farm without exceeding the current limits of rotor and grid-side converters. The entire study is carried out in real time on a real-time digital simulator platform.
Frugal path mechanisms

We consider the problem of selecting a low-cost s - t path in a graph where the edge costs are a secret, known only to the various economic agents who own them. To solve this problem, Nisan and Ronen applied the celebrated Vickrey-Clarke-Groves (VCG) mechanism, which pays a premium to induce the edges so as to reveal their costs truthfully. We observe that this premium can be unacceptably high. There are simple instances where the mechanism pays Θ(n) times the actual cost of the path, even if there is an alternate path available that costs only (1 p e) times as much. This inspires the frugal path problem, which is to design a mechanism that selects a path and induces truthful cost revelation, without paying such a high premium.This article contributes negative results on the frugal path problem. On two large classes of graphs, including those having three node-disjoint s - t paths, we prove that no reasonable mechanism can always avoid paying a high premium to induce truthtelling. In particular, we introduce a general class of min function mechanisms, and show that all min function mechanisms can be forced to overpay just as badly as VCG. Meanwhile, we prove that every truthful mechanism satisfying some reasonable properties is a min function mechanism.Our results generalize to the problem of hiring a team to complete a task, where the analog of a path in the graph is a subset of the agents constituting a team capable of completing the task.
Sensitivity Analysis of the Aeroacoustic Response of Turbomachinery Blade Rows

A method for computing the change or sensitivity of the aeroacoustic response of a cascade to small changes in airfoil and cascade geometry is presented. The steady flow is modeled by the full potential equation, which is discretized using a variational finite element technique. A streamline computational grid is generated as part of the steady solution. Newton iteration is used to solve for the nonlinear steady flow and grid equations with lower-upper (LU) matrix decomposition plus one forward and one back substitution used to solve the resulting matrix equations. Similarly, the unsteady small disturbance flow about the nonlinear mean flow is modeled by the linearized potential equation together with rapid distortion theory to account for vortical gusts. These linearized equations are discretized using finite elements and solved with a single LU decomposition. The sensitivities of the steady and unsteady flowfields to small changes in geometry are computed by perturbing the discretized equations about the nominal solutions. The resulting linear system of equations can be solved very efficiently because the LU factors of the resulting matrix equations are computed as part of the nominal steady and unsteady solution. Results are presented in this paper to show the accuracy and efficiency of the method, and the implications for aeroacoustic design of turbomachinery blades are discussed.
A MODIFIED A* ALGORITHM FOR ROBUST PLAN RECOGNITION

The traditional problem of plan recognition can be solved in a straightforward manner by a graph-searching algorithm such as A*. A few simple extensions allow the algorithm to handle situations in which the user has an incorrect plan. However, it turns out that recognizing structural errors is computationally a much more complex problem than recognizing plans with simple constraint violations. Four algorithms are presented here, starting with a direct adaptation of A* for recognizing correct plans, and progressing to an optimized algorithm for recognizing violated, ill-formed plans.
The anapole form factor of the nucleon

Abstract The anapole form factor of the nucleon is calculated in chiral perturbation theory in leading order. To this order, the form factor originates from the pion cloud, and is proportional to the non-derivative parity-violating pion–nucleon coupling. The momentum dependence of the form factor – and in particular, its radius – is completely determined by the pion mass.
The Effect of Neutron Star Rotation on the Properties of Thermonuclear X-ray Bursts

Using observations with the Rossi X-Ray Timing Explorer, we previously showed that millisecond oscillations occur preferentially in thermonuclear X-ray bursts with photospheric radius expansion from sources rotating near 600 Hz, while they occur with equal likelihood in X-ray bursts with and without radius expansion for sources rotating near 300 Hz. In this paper, we use a larger sample of data to demonstrate that the detectability of the oscillations is not directly determined by the properties of the X-ray bursts. Instead, we find that (1) the oscillations are observed almost exclusively when the accretion rate onto the neutron star is high, but that (2) radius expansion is only observed at high accretion rates from the 600 Hz sources, whereas it occurs only at low accretion rates in the 300 Hz sources. The persistent millisecond pulsars provide the only apparent exceptions to these trends. The first result might be explained if the oscillation amplitudes are attenuated at low accretion rates by an extended electron corona. The second result indicates that the rotation period of the neutron star determines how the burst properties vary with accretion rate, possibly through the differences in the effective surface gravity or the strength of the Coriolis force.
An Atom‐Economic Three‐Carbon Chain Extension to Give Enamides

Di- or trisubstituted alkenes of defined geometry, with terminal enamide groups, are formed in an atom-economic three-carbon chain extension of alkynes with allyl amides catalyzed by ruthenium (see, for example, Equation (1); Boc=tert-butoxycarbonyl, TMS=trimethylsilyl).
Auxiliary gauge mediation: a new route to mini-split supersymmetry

The discovery of a standard-model-like Higgs at 126 GeV and the absence of squark signals thus far at the LHC both point towards a mini-split spectrum for super- symmetry. Within standard paradigms, it is non-trivial to realize a mini-split spectrum with heavier sfermions but lighter gauginos while simultaneously generating Higgs sector soft terms of the correct magnitude, suggesting the need for new models of supersymmetry breaking and mediation. In this paper, we present a new approach to mini-split model building based on gauge mediation by \auxiliary groups", which are the anomaly-free con- tinuous symmetries of the standard model in the limit of vanishing Yukawa couplings. In addition to the well-known avor SU(3) F and baryon-minus-lepton U(1)B L groups, we nd that an additional U(1) H acting on the Higgs doublets alone can be used to generate Higgs soft masses and B-terms necessary for a complete model of mini-split. Auxiliary gauge mediation is a special case of Higgsed gauge mediation, and we review the resulting two-loop scalar soft terms as well as three-loop gaugino masses. Along the way, we present a complete two-loop calculation of A-terms and B-terms in gauge mediation, which | contrary to a common misconception | includes a non-zero contribution at the messenger threshold which can be sizable in models with light gauginos. We present several phe- nomenologically acceptable mini-split spectra arising from auxiliary gauge mediation and highlight a complete minimal model which realizes the required spectrum and Higgs sector soft terms with a single U(1)X auxiliary gauge symmetry. We discuss possible experimental consequences.
Plasma near a divertor plate: effects of surface roughness and particle drifts

The surface of a divertor plate has usually a certain degree of ''roughness.'' Depending on the material and the exposure time, the size of surface features may range from submicrons to a fraction of a millimeter, covering a range of spatial scales from well below the electron gyroradius, {rho}{sub e} to significantly above the ion gyroradius, {rho}{sub i}. The plasma approaches the divertor plate along a magnetic field which forms a shallow angle, {alpha} << 1, with the plate surface. Under such circumstances, a significant ''shadowing'' effect takes place, with only a small part of the surface being accessible to the plasma particles. A methodology is presented that allows one to find the fraction ({var_epsilon}{sub e} and {var_epsilon}{sub i}) of the surface geometrically accessible for the electrons and the ions. At small {alpha}, {var_epsilon}{sub e,i} are typically small, meaning a strong local enhancement of heat and particle fluxes. In a broad range of parameters, {var_epsilon}{sub e}, is also much smaller than {var_epsilon}{sub i}. As the surface features are usually greater than the Debye radius, this leads to the formation of an ambipolar potential which causes reflection of part of the ions from the surface. The resulting albedo of the divertormore » plate for the plasma ions can be as high as 50%. Gradual diffusion of the plasma electrons into the zones reflecting the ions, reduces ambipolar fields and brings the ion albedo back to very small values. We present estimates of the time scales governing the neutralization process. This time scale shows itself up in the sheath boundary conditions for non-steady-state perturbations. The effect of surface roughness on secondary electron emission is discussed and it is shown that, depending on the surface structure, it may be smaller or greater than for a perfectly flat plate. We consider modifications of the sheath current-voltage characteristics by particle drifts. The presence of reflected ions reduces the ion diamagnetic current in the ion sub-sheath and significantly changes the ion response. This, in turn, affects sheath-controlled instabilities, which are sensitive to the tilt of the magnetic field.« less
Efficient representation of perm groups

This note presents an elementary version of Sims's algorithm for computing strong generators of a given perm group, together with a proof of correctness and some notes about appropriate lowlevel data structures. Upper and lower bounds on the running time are also obtained. (Following a suggestion of Vaughan Pratt, we adopt the convention that perm=permutation, perhaps thereby saving millions of syllables in future research.)
The WIRED Survey. II. Infrared Excesses in the SDSS DR7 White Dwarf Catalog

With the launch of the Wide-field Infrared Survey Explorer (WISE), a new era of detecting planetary debris and brown dwarfs (BDs) around white dwarfs (WDs) has begun with the WISE InfraRed Excesses around Degenerates (WIRED) Survey. The WIRED Survey is sensitive to substellar objects and dusty debris around WDs out to distances exceeding 100 pc, well beyond the completeness level of local WDs. In this paper, we present a cross-correlation of the preliminary Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) WD catalog between the WISE, Two-Micron All Sky Survey (2MASS), UKIRT Infrared Deep Sky Survey (UKIDSS), and SDSS DR7 photometric catalogs. From ~18,000 input targets, there are WISE detections comprising 344 "naked" WDs (detection of the WD photosphere only), 1020 candidate WD+M dwarf binaries, 42 candidate WD+BD systems, 52 candidate WD+dust disk systems, and 69 targets with indeterminate infrared excess. We classified all of the detected targets through spectral energy distribution model fitting of the merged optical, near-IR, and WISE photometry. Some of these detections could be the result of contaminating sources within the large (≈6'') WISE point-spread function; we make a preliminary estimate for the rates of contamination for our WD+BD and WD+disk candidates and provide notes for each target of interest. Each candidate presented here should be confirmed with higher angular resolution infrared imaging or infrared spectroscopy. We also present an overview of the observational characteristics of the detected WDs in the WISE photometric bands, including the relative frequencies of candidate WD+M, WD+BD, and WD+disk systems.
Estimating the Employer Switching Costs and Wage Responses of Forward‐Looking Engineers

This article estimates worker switching costs and how much the employer switching of experienced engineers responds to outside wage offers. I use data on engineers across Swedish private sector firms to estimate the relative importance of employer wage policies and switching costs in a dynamic programming, discrete choice model of employer choice. The differentiated firms are modeled in employer characteristic space, and each firm has its own age‐wage profile. A majority of engineers have moderately high switching costs and a minority of experienced workers are responsive to outside wage offers. Younger workers are more sensitive to outside wage offers.
Thickness-dependent coercive mechanisms in exchange-biased bilayers

We present an investigation of the effect of ferromagnetic layer thickness on the exchange bias and coercivity enhancement in antiferromagnet/ferromagnet bilayers. At low temperatures both the exchange bias and coercivity closely follow an inverse thickness relationship, contrary to several recent theoretical predictions. Furthermore, the temperature dependence of the coercivity as a function of the ferromagnet thickness provides clear evidence for the existence of two distinct regimes. These regimes were probed with conventional magnetometry, anisotropic magnetoresistance, and polarized neutron reflectometry. At low thickness the coercivity exhibits a monotonic temperature dependence, whereas at higher thickness a broad maximum occurs in the vicinity of the N\'eel temperature. These regimes are delineated by a particular ratio of the ferromagnet to antiferromagnet thickness. We propose that the ratio of the anisotropy energies in the two layers determines whether the coercivity is dominated by the ferromagnetic layer itself or the interaction of the ferromagnetic layer with the antiferromagnet.
Analytic Model of Catastrophic Yaw

A quantitative model of the non-linear motion leading to catastrophic yaw of finned missiles is presented. The coupled roll-yaw dynamics of the missile, acted on by the trim angle of attack due to slight configurational asymmetries, is represented by pitch-yaw and roll equations of motion that include cubic aerodynamic coefficients and roll orientation-dependent induced moments. The steady-state equilibrium points of the system are found and their stability is determined by linearization. The solutions are evaluated by comparison with numerical integration of the equations of motion, proving the capability of the model to predict catastrophic yaw. Nomenclature CD = drag force coefficient CLα = angle of attack coefficient of the lift force CNα = angle of attack coefficient of the normal force CMα = angle of attack coefficient of the pitch moment Cli = induced roll moment coefficient Clp = roll damping moment coefficient Clδ = roll effectiveness moment coefficient CMpα = angle of attack coefficient of the Magnus moment
Statistical pattern analysis of partial discharge measurements for quality assessment of insulation systems in high-voltage electrical machinery

In this paper, we present a new statistical analysis method of phase-resolved partial discharge (PD) measurements for the quality assessment of electrical insulation in high-voltage machinery. The method is based on a supervised classification approach which utilizes histogram similarity analysis. The motivation for choosing histogram similarity analysis is twofold. First, the phase-resolved PD measurement itself is, in fact, a two-dimensional histogram. Therefore, a histogram-matching-based approach suits the very nature of the data. Second, histogram similarity analysis combines the typical statistical parameters, used in PD analysis, in a statistically powerful and rigorous way. In our study, we utilize various histogram types and similarity analysis, including correlation, chi-square, and Kolmogorov-Smirnov tests. Further, we propose a postprocessing method to quantify the accuracy of classification results which enables the user to make soft decisions. Our experimental study on laboratory samples demonstrates that the method shows strong potential in detection and classification of insulation defects. The results from our study suggest that the proposed method provides a powerful, general, and mathematically simple approach to the analysis of phase-resolved PD measurements.
EMU and Long Interest Rates in Germany

Has the expectation that monetary policy might in the foreseeable future be in the hands of a European monetary institution maintained long interest rates in Germany at higher levels then they would otherwise be? Since the future European Central Bank (ECB) might be expected to adopt some weighted average of the traditional monetary policy stances of its members—tougher than most, perhaps, but not as tough as the Bundesbank, implying higher expected inflation and perhaps credibility premia—this idea has a fair amount of intuitive appeal. Moreover, it is consistent with three sets of facts, which have each received considerable attention in recent months: First, opinion polls indicate that a large majority of Germans (almost two-thirds, according to a September 1995 report in The Economist) oppose a common currency, presumably because the D-Mark has a track record of stability while the future European currency does not2. If this view is shared by financial markets, it could contribute to relatively high long yields.
Classical Dynamical r-Matrices¶and Homogeneous Poisson Structures on G/H and K/T

Let G be a finite dimensional simple complex group equipped with the standard Poisson Lie group structure. We show that all G-homogeneous (holomorphic) Poisson structures on G/H, where H⊂G is a Cartan subgroup, come from solutions to the Classical Dynamical Yang–Baxter equations which are classified by Etingof and Varchenko. A similar result holds for a maximal compact subgroup K, and we get a family of K-homogeneous Poisson structures on K/T, where T=K∩H is a maximal torus of K. This family exhausts all K-homogeneous Poisson structures on K/T up to isomorphisms. We study some Poisson geometrical properties of members of this family such as their symplectic leaves, their modular classes, and the moment maps for the T-action.
Model studies in molecular recognition

Recognition at the molecular level is a fundamental characteristic of biochemical systems. Recent models developed in bioorganic chemistry have revealed the importance of complementarity in size, shape, and functional groups in molecular recognition. Structures that feature a cleft are particularly effective in regard to complementarity since functional groups attached to the interior of the cleft converge on substrates held inside. The molecular clefts offer the advantage of efficient construction; their surfaces can be tailored for specific applications. This article describes their use for recognition of acids, bases, amino acids, metal ions, and neutral substrates. Their ability to provide microenvironments complementary to asymmetric molecules and their future promise are discussed.
Team gender diversity and investment decision-making behavior

Purpose – The purpose of this paper is to investigate whether the gender composition of a fund management team influences investment decision-making behavior. Specifically, we focus on how portfolio choice is affected by team risk aversion and loss aversion. Design/methodology/approach – Using an experimental economics approach, the paper examines the relationship between gender diversity and investment decisions. Teams of four persons each were given the task of making investment portfolio management decisions. Findings – The paper finds that team composition does influence financial decisions with regard to the assessment of risk and loss. The paper finds evidence that a male presence increases the probability of selecting a higher risk investment. However, the all male teams are not the most risk seeking. Moreover, having a male presence can increase loss aversion. Originality/value – In the context of workforce composition, these results could have important implications for team investment decisions ...
Zero-Crossing Detector Based Reconfigurable Analog System

A reconfigurable analog system is presented that implements pipelined ADCs, switched-capacitor filters, and programmable gain amplifiers. Each block employs a zero-crossing based circuit for easy reconfigurability and power efficiency. Configured as a 10-bit ADC, the chip consumes 1.92 mW at 50 MSPS with ENOB of 8.02 bit and FOM of 150 fJ/conversion-step. A second-order and a third-order Butterworth filter are also demonstrated. The thermal noise of the system is analyzed in different configurations and the dominant sources of noise are determined. It is shown that around 90% of the noise in ADC configuration is generated by the first stage, while in filter configuration, around 90% of the noise is generated by the last stage. The chip is implemented in a 65 nm technology.
Reducing impact of cache miss stalls in embedded systems by extracting guaranteed independent instructions

Today, embedded processors are expected to be able to run algorithmically complex, memory-intensive applications that were originally designed and coded for general-purpose processors. As such, the impact of memory latencies on the execution time increasingly becomes evident. All the while, it is also expected that embedded processors be power-conscientious as well as of minimal area impact, as they are often used in mobile devices such as wireless smartphones and portable MP3 players. As a result, traditional methods for addressing performance and memory latencies, such as multiple issue, out-of-order execution and large, associative caches, are not aptly suited for the mobile embedded domain due to the significant area and power overhead. This paper explores a novel approach to mitigating execution delays caused by memory latencies that would otherwise not be possible in a regular in-order, single-issue embedded processor without large, power-hungry constructs like a Reorder Buffer (ROB). The concept relies on efficiently leveraging both compile-time and run-time information to safely allow non-data-dependent instructions to continue executing in the event of a memory stall. The simulation results show significant improvement in overall execution throughput of approximately 11%, while having a minimal impact on area overhead and power.
Improved IRI predictions for the GEOSAT time period

Abstract Single-frequency altimeter measurements require an estimate of the signal retardation effect in the ionosphere. Ionospheric models like the International Reference Ionosphere (IRI) are being used to obtain these correction factors. Incorporation of worldwide ionosonde measurements is discussed as a way towards more accurate predictions. Using measurements of the F peak critical frequency (foF2) from more than 70 ionosondes we have derived (hour and month dependent) regional and global ionospheric-effective solar indices. Replacing the solar index in IRI with these new indices we could improve the IRI estimates for the GEOSAT time period (1986–1989) by a few percent.
Stability and causality in dissipative relativistic fluids

The standard theory of relativistic dissipative fluid mechanics developed by Eckart contains several undesirable features: thermal and viscous fluctuations propagate acausally; there exist generic short wavelength secular instabilities; and there is not a well posed initial value problem for rotating fluids. In this paper we examine whether the generalization of Eckart's theory developed by Israel has succeeded in eliminating these features. We first generalize Israel's theory to include the possibility of nonuniform equilibrium configurations. This generalization allows us to describe equilibrium configurations which may be rotating and self-gravitating such as neutron stars. We then evaluate the stability conditions for these fluids and compute the characteristic velocities at which perturbations propagate. Our main result is that if these fluids are stable, then the characteristic velocities are subluminal and the perturbations propagate via hyperbolic equations. Thus Israel's theory is causal for all stable fluids. In addition, there is no generic instability, and the initial value problem is well posed. In our opinion, for these reasons, Israel's theory should replace Eckart's as the standard theory of relativistic dissipative fluid mechanics.
Lift from Spanwise Flow in Simple Flapping Wings

Spanwise flow contributes to lift in thin flat-plate zero-pitch-angle flapping wings in quiescent air. It is reasonable to maintain only the kinematics and mechanical complexity absolutely necessary in developing flapping-wing micro air vehicles. This study continues the quantification of the lift generated from a flapping motion of absolute minimum complexity thought to be capable of generating lift. A flapping-wing micro air vehicle with rectangular planform wings fabricated in-house (semispan aspect ratios from 1.5 to 4.0) was used to quantify the contributions to lift from flow along the span of wings at numerous points throughout the flapping cycle under a variety of operating conditions (3-6 Hz and Reynolds numbers of 6000-15,000). These experiments were performed for several aspect ratios for flat-plate and spanwise-cambered wings. The lift force was quantified experimentally using a force transducer and a high-speed camera. Digital particle image velocimetry was used to determine the lift contributions of spanwise flow to the total measured lift. Additionally, the presence of spanwise camber was shown to affect the transient lift behavior.
σ- and π-Bond Strengths in Main Group 3-5 Compounds

The sigma- and pi-bond strengths for the molecules BH2NH2, BH2PH2, AlH2NH2, and AlH2PH2 have been calculated by using ab initio molecular electronic structure theory at the CCSD(T)/CBS level. The adiabatic pi-bond energy is defined as the rotation barrier between the equilibrium ground-state configuration and the C(s)symmetry transition state for torsion about the A-X bond. We also report intrinsic pi-bond energies corresponding to the adiabatic rotation barrier corrected for the inversion barrier at N or P. The adiabatic sigma-bond energy is defined as the dissociation energy of AH2XH2 to AH2 + XH2 in their ground states minus the adiabatic pi-bond energy. The adiabatic sigma-bond strengths for the molecules BH2NH2, BH2PH2, AlH2NH2, and AlH2PH2 are 109.8, 98.8, 77.6, and 68.3 kcal/mol, respectively, and the corresponding adiabatic pi-bond strengths are 29.9, 10.5, 9.2, and 2.7 kcal/mol, respectively.
Numerical Integration of Navier-Stokes Equations

T is extensive literature on the numerical integration of some difference forms of the Navier-Stokes equations. The references quoted herein are those relevant to later discussions and not intended to be complete. There is also extensive literature on the mathematics of difference methods for the solution of partial differential equations for which Ref. 1 is a comprehensive review and contains an extensive bibliography. The present paper is an attempt to develop the implications of a mathematical theorem, which, when put into proper perspective, offers a unified and coherent treatment of various practical aspects of computation. Like approximate differential analyses and physical tests, numerical methods are fallible. Larger and faster computers offer no easy answer to computational difficulties like stability and convergence. Smooth and physically reasonable results of computation are often less accurate than those not so smooth. Since the true asymptotic nature is difficult to establish, both the difference and the differential approximations are nonrigorous; but they are useful, especially with the help of physical experimentation and rigorous mathematical results. We are sympathetic to such heuristic and nonrigorous analysis in favor of obtaining results useful in practice. We shall consider only the difference form of the NavierStokes equations in Eulerian coordinates. Lagrangian coordinates are convenient for flows involving free-surface boundary or active processes associated with fluid elements. It suffers, however, from the serious distortions of the Lagrangian net and from the cummulative errors of the particle paths at large times. Thus various mixed or coupled Eulerian-Lagrangian schemes have been developed even for free boundary problems. Eulerian formulation, even for a single fluid in the absence of a free boundary, has its share of problems, which we shall discuss. We write, for the NavierStokes equations,
Metal-catalyzed bond reorganization of 1,3-diynes

1,3-Diynes possessing propargylic heteroatom substituents provide functionalized 1,5-dien-3-ynes when catalyzed by platinum and gold. This rearrangement implies the involvement of metallotropic [1,3]-shift of the intermediate alkynyl metal carbene species. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
A simple preparation of S-alkyl homocysteine derivatives: S-phosphonomethyl homocysteines as inhibitors of glutamine synthetase

Abstract A facile synthesis of S-alkyl homocysteines is described which features the coupling of sodium alkyl thiolates with methyl 4-bromo-2-phthalimidobutyrate, followed by hydrolysis. This approach is exemplified by the synthesis of S-phosphonomethyl homocysteine sulfone, a new inhibitor of the enzyme glutamine synthetase.
Transannular macrocyclization via intramolecular B-alkyl Suzuki reaction.

Transannular macrocyclizations via intramolecular B-alkyl Suzuki reactions are described. Regioselective terminal olefin hydroboration with 9-BBN followed by Pd(0)-catalyzed Suzuki reaction in the presence of a base such as TlOEt at high dilution generates macrocycles with a high degree of control over olefin geometry with isomerically pure E or Z vinyl iodide substrates. These reactions are complementary to ring closing metathesis (RCM) macrocyclizations and may prove superior in cases where control of olefin geometry is required.