cssi/SciSciGPT-SciSciNet huggingface dataset:
Cyclic weighted centroid localization for spectrally overlapped sources in cognitive radio networks

We consider the problem of localizing spectrally overlapped sources in cognitive radio networks. A new weighted centroid localization algorithm (WCL) called Cyclic WCL is proposed, which exploits the cyclostationary feature of the target signal to estimate its location coordinates. In order to analyze the algorithm in terms of root-mean-square error (RMSE), we model the location estimates as the ratios of quadratic forms in a Gaussian random vector. With analysis and simulation, we show the impact of the interferer location and its modulation scheme on the RMSE. We also study the RMSE performance of the algorithm for different power levels of the target and the interference. Further, the comparison between Cyclic WCL and WCL w/o cyclostationarity is presented. It is observed that the Cyclic WCL provides significant performance gain over WCL.
Snap-together motion: assembling run-time animations

Many virtual environments and games must be populated with synthetic characters to create the desired experience. These characters must move with sufficient realism, so as not to destroy the visual quality of the experience, yet be responsive, controllable, and efficient to simulate. In this paper we present an approach to character motion called Snap-Together Motion that addresses the unique demands of virtual environments. Snap-Together Motion (STM) preprocesses a corpus of motion capture examples into a set of short clips that can be concatenated to make continuous streams of motion. The result process is a simple graph structure that facilitates efficient planning of character motions. A user-guided process selects "common" character poses and the system automatically synthesizes multi-way transitions that connect through these poses. In this manner well-connected graphs can be constructed to suit a particular application, allowing for practical interactive control without the effort of manually specifying all transitions.
Differentiating hepatocellular carcinoma from hepatitis C using metabolite profiling

Hepatocellular carcinoma (HCC) accounts for most liver cancer cases worldwide. Contraction of the hepatitis C virus (HCV) is considered a major risk factor for liver cancer. In order to identify the risk of cancer, metabolic profiling of serum samples from patients with HCC (n=40) and HCV (n=22) was performed by 1H nuclear magnetic resonance spectroscopy. Multivariate statistical analysis showed a distinct separation of the two patient cohorts, indicating a distinct metabolic difference between HCC and HCV patient groups based on signals from lipids and other individual metabolites. Univariate analysis showed that three metabolites (choline, valine and creatinine) were significantly altered in HCC. A PLS-DA model based on these three metabolites showed a sensitivity of 80%, specificity of 71% and an area under the receiver operating curve of 0.83, outperforming the clinical marker alpha-fetoprotein (AFP). The robustness of the model was tested using Monte-Carlo cross validation (MCCV). This study showed that metabolite profiling could provide an alternative approach for HCC screening in HCV patients, many of whom have high risk for developing liver cancer.
X-Ray Timing of PSR J1852+0040 in Kesteven 79: Evidence of Neutron Stars Weakly Magnetized at Birth

The 105 ms X-ray pulsar J1852+0040 is the central compact object (CCO) in supernova remnant Kes 79. We report a sensitive upper limit on its radio flux density of 12 ?Jy at 2 GHz using the NRAO Green Bank Telescope. Timing using the Newton X-Ray Multi-Mirror Mission (XMM-Newton) and the Chandra X-Ray Observatory over a 2.4 yr span reveals no significant change in its spin period. The 2 ? upper limit on the period derivative leads, in the dipole spin-down formalism, to an energy loss rate ? 8 Myr. This value of ?c exceeds the age of the SNR by 3 orders of magnitude, implying that the pulsar was born spinning at its current period. However, the X-ray luminosity of Lbol ? 3 ? 1033(d/7.1 kpc)2 ergs s-1 is a large fraction of ?, which challenges the rotation-powered assumption. Instead, its high blackbody temperature kTBB = 0.46 ? 0.04 keV, small blackbody radius RBB ? 0.8 km, and large pulsed fraction fp ? 80% may be evidence of accretion onto a polar cap, possibly from a fallback disk made of supernova debris. If Bp 0.1 s from radio pulsar surveys, where Bp 40 Myr) or recycled pulsars. Finally, such a CCO, if born in SN 1987A, could explain the nondetection of a pulsar there.
On backward product of stochastic matrices

We study the ergodicity of backward product of stochastic and doubly stochastic matrices by introducing the concept of absolute infinite flow property. We show that this property is necessary for ergodicity of any chain of stochastic matrices, by defining and exploring the properties of a rotational transformation for a stochastic chain. Then, we establish that the absolute infinite flow property is equivalent to ergodicity for doubly stochastic chains. Furthermore, we develop a rate of convergence result for ergodic doubly stochastic chains. We also investigate the limiting behavior of a doubly stochastic chain and show that the product of doubly stochastic matrices is convergent up to a permutation sequence. Finally, we apply the results to provide a necessary and sufficient condition for the absolute asymptotic stability of a discrete linear inclusion driven by doubly stochastic matrices.
The Beta Problem: A Study of Abell 262

We present an investigation of the dynamical state of the cluster A262. Existing optical line-of-sight velocities for select cluster galaxies have been augmented by new data obtained with the Automated Multi-Object Spectrograph at Lick Observatory. We —nd evidence for a virialized early-type population distinct from a late-type population infalling from the Pisces-Perseus supercluster ridge. We also report on a tertiary population of low-luminosity galaxies the velocity dispersion of which distinguishes them from both the early- and late-type galaxies. We supplement our investigation with an analysis of archival X-ray data. A temperature is determined using ASCA GIS data, and a gas pro—le is derived from ROSAT HRI data. The increased statistics of our sample results in a picture of A262 with signi—cant diUerences from earlier work. A previously proposed solution to the ii b-problem ˇˇ in A262 in which the gas temperature is signi—cantly higher than the galaxy temperature is shown to result from using too low a velocity dispersion for the early-type galaxies. Our data present a consistent picture of A262 in which there is no ii b-problem,ˇˇ and the gas and galaxy temperature are roughly comparable. There is no longer any requirement for extensive galaxy-gas feedback to drastically overheat the gas with respect to the galaxies. We also demonstrate that entropy —oor models can explain the recent discovery that the b values determined by cluster gas and the cluster core radii are correlated. . .. . . . . .. . . . . . . . .. . . . . .. . . . . .. . . .
Physical simulation of nuclear reactor power plant systems

One method of control of a heterogeneous boiling reactor uses the steam pressure in the reactor vessel to control the height of the water reflector surrounding the core. As the steam pressure increases, the reflector height and the reactor power level decrease. Thus, as the steam load varies, the pressure varies and forces the reactor power to follow the load changes.
Propagation of Thermonuclear Flames on Rapidly Rotating Neutron Stars: Extreme Weather during Type I X-Ray Bursts

We analyze the global hydrodynamic flow in the ocean of an accreting, rapidly rotating, nonmagnetic neutron star in a low-mass X-ray binary during a type I X-ray burst. We use both analytical arguments and numerical simulations of simplified models for ocean burning. Our analysis extends previous work by taking into account the rapid rotation of the star and the lift-up of the burning ocean during the burst. We find a new regime for the spreading of a nuclear burning front, where the flame is carried along a coherent shear flow across the front. If turbulent viscosity is weak, the speed of flame propagation is v_(flame) ~ (gh)^(1/2)/ft_n ~ 20 km s^(-1), where h is the scale height of the burning ocean, g is the local gravitational acceleration, t_n is the timescale for fast nuclear burning during the burst, and f is the Coriolis parameter, i.e., twice the local vertical component of the spin vector. If turbulent viscosity is dynamically important, the flame speed increases and reaches the maximum value, v^(max)_(flame_ ~ (gh/ft_n)^(1/2) ~ 300 km s^(-1), when the eddy overturn frequency is comparable to the Coriolis parameter f. We show that, as a result of rotationally reduced gravity, the thermonuclear runaway which ignites the ocean is likely to begin on the equator. The equatorial belt is ignited at the beginning of the burst, and the flame then propagates from the equator to the poles. Inhomogeneous cooling (equator first, poles second) of the hot ashes drives strong zonal currents which may be unstable to the formation of Jupiter-type vortices; we conjecture that these vortices are responsible for coherent modulation of X-ray flux in the tails of some bursts. We consider the effect of strong zonal currents on the frequency of modulation of the X-ray flux and show that the large values of the frequency drifts observed in some bursts can be accounted for within our model combined with the model of homogeneous radial expansion. Additionally, if vortices or other inhomogeneities are trapped in the forward zonal flows around the propagating burning front, fast chirps with large frequency ranges (~25-500 Hz) may be detectable during the burst rise. Finally, we argue that an MHD dynamo within the burning front can generate a small-scale magnetic field, which may enforce vertically rigid flow in the front's wake and can explain the coherence of oscillations in the burst tail.
Titania nanostructures: a biomedical perspective

Titania nanostructures (TNSs) provide exceptional choice for developing innovative biomedical applications due to their unique and characteristic biocompatibility, and their ability to integrate functional moieties to modulate biological responses. In this review, we provided first-hand knowledge of all contemporary TNS-based biomedical research for future innovations and benefits to society and patient care. Starting with a brief discussion on the crystallographic phases of TNSs, we presented a detailed description of the commonly used fabrication and surface modification techniques, followed by a systematic and comprehensive summary of various biomedical evaluations with a special emphasis on drug-delivery, tissue engineering, biosensor, and anti-bacterial applications.
An interpretation of saturation phenomena as Glauber-Gribov multiple parton scatterings

We compare two formalism that describe minijet production in pA and AA: pQCD supplemented by Glauber-Gribov multiple semi-hard parton scatterings (pQCD + Glauber), and the Color Glass Condensate (CGC). We argue that in a suitable limit they are equivalent to each other, the PQCD + Glauber model being more accurate from a numerical point of view. Finally, we analyze RHIC data on Au−Au integrated charged multiplicities in the pQCD + Glauber framework, and conclude that at least at central rapidity there is no sign of gluon saturation.
A Catalytic Asymmetric Synthesis of Polysubstituted Piperidines Using a Rhodium (I) Catalyzed [2+2+2] Cycloaddition Employing a Cleavable Tether

An enantioselective rhodium (I) catalyzed [2+2+2] cycloaddition with a cleavable tether has been developed. The reaction proceeds with a variety of alkyne substrates in good yield and high enantioselectivity. Upon reduction of the vinylogous amide in high diastereoselectivity (>19:1) and cleavage of the tether, N-methylpiperidine products with functional group handles can be accessed.
Synthesis, reactivity and structure of nitrodiazoacetic acid

Nitrodiazoacetic acid was prepared and its structure determined by low temperature X-ray crystallography. There is good agreement between the experimentally determined structure and that calculated at the ab initio rhf/3-21 G level of theory. The acid is stable in neat trifluoroacetic acid and less stable in neutral non-polar solutions. In neutral polar solutions it undergoes rapid decarboxylation to yield nitrodiazomethane.
Introduction to the special issue on agent-based computational economics

Abstract A brief overview of agent-based computational economics (ACE) is given, followed by a synopsis of the articles included in this special issue on ACE and in a companion special issue on ACE scheduled to appear in Computational Economics.
Pressure-Scaling of Pressure-Swirl Atomizer Cone Angles

An experimental investigation was conducted to study the effects of increased ambient pressure (up to 6.89 MPa) and increased nozzle pressure drop (up to 2.8 MPa) on the cone angles for sprays produced by pressure-swirl atomizers having varying amounts of initial swirl. This study extends the classical results of DeCorso and Kemeny, (1957, "Effect of Ambient and Fuel Pressure on Nozzle Spray Angle," ASME Transactions, 79(3), pp. 607-615). Shadow photography was used to measure cone angles at x/D 0 =10, 20, 40, and 60. Our lower pressure results for atomizer swirl numbers of 0.50 and 0.25 are consistent with those of DeCorso and Kemeny, who observed a decrease in cone angle with an increase in nozzle pressure drop, AP, and ambient density, pair, until a minimum cone angle was reached when ΔP ρair 1,6 ∼ 100 MPa(kg/m 3 ) 1,6 (equivalent to 200 psi(lbm/ ft?) 1.6 ). Results for atomizers having higher initial swirl do not match the DeCorso and Kemeny results as well, suggesting that their correlation be used with caution. Another key finding is that an increase in ΔP ρair 1,6 to a value of 600 MPa(kg/m 3 ) 1.6 leads to continued decrease in cone angle, but that a subsequent increase to 2000 MPa(kg/m 3 ) 1.6 has little effect on cone angle. Finally, there was little effect of nozzle pressure drop on cone angle, in contrast to findings of previous workers. These effects are hypothesized to be due to gas entrainment.
Application of adaptive control to economic stabilization policy

In this paper the problem of simultaneous estimation and Control in macroeconometric models is considered, Using the adaptive control scheme of Deshpande et al. (1073)on a linear 28-variable model of the U.S. economy, it is shown that the unknown parameters in the model can be identified while simultaneously controlling the economy, A comparison of the average value of the criterion function (with and without ‘ learning ’) is made to emphasize the importance of using the adaptive systems approach in econometrics.
The Fate of the First Galaxies. II. Effects of Radiative Feedback

We use three-dimensional cosmological simulations with radiative transfer to study the formation and evolution of the first galaxies in a ΛCDM cosmology. The simulations include continuum radiative transfer using the optically thin variable Eddington tensor (OTVET) approximation and line radiative transfer in the H2 Lyman-Werner bands of the UV background radiation. Chemical and thermal processes are treated in detail, particularly the ones relevant for H2 formation and destruction. We find that the first luminous objects (small-halo objects) are characterized by bursting star formation (SF) that is self-regulated by a feedback process acting on cosmological instead of galactic scales. The global SF history is regulated by the mean number of ionizing photons that escape from each source, UVfesc. It is almost independent of the assumed SF efficiency parameter, *, and the intensity of the dissociating background. The main feedback process that regulates the SF is the reformation of H2 in front of H II regions and inside relic H II regions. The H II regions remain confined inside filaments, maximizing the production of H2 in overdense regions through cyclic destruction/reformation of H2. If UVfesc > 10-7/*, the SF is self-regulated, photoevaporation of small-halo objects dominates the metal pollution of the low-density intergalactic medium, and the mass of produced metals depends only on fesc. If UVfesc 10-7/*, positive feedback dominates, and small-halo objects constitute the bulk of the mass in stars and metals until at least redshift z ~ 10. Small-halo objects cannot reionize the universe because the feedback mechanism confines the H II regions inside the large-scale structure filaments. In contrast to massive objects (large halos), which can reionize voids, small-halo objects partially ionize only the dense filaments while leaving the voids mostly neutral.
INFINITESIMAL CHEREDNIK ALGEBRAS AS W-ALGEBRAS

In this article we establish an isomorphism between universal infinitesimal Cherednik algebras and W-algebras for Lie algebras of the same type and 1-block nilpotent elements. As a consequence we obtain some fundamental results about infinitesimal Cherednik algebras.
Path ideals of weighted graphs

Abstract We introduce and study the weighted r -path ideal of a weighted graph G ω , which is a common generalization of Conca and De Negri's r -path ideal for unweighted graphs and Paulsen and Sather-Wagstaff's edge ideal of the weighted graph. Over a field, we explicitly describe primary decompositions of these ideals, and we characterize Cohen–Macaulayness of these ideals for trees (with arbitrary r ) and complete graphs (for r = 2 ).
On noncommutative Nahm transform

Motivated by the recently observed relation between the physics of D-branes in the background of B-field and the noncommutative geometry we study the analogue of the Nahm transform for the instantons on the noncommutative torus.
A public health data system

In mid-December, 1972 Clemson University became actively engaged in the technical development of a Public Health Data System for the Appalachian II District Health Department. Phase I of the implementation (ending June 30, 1973) has now been completed and has allowed both the Health Department and Clemson to more accurately measure development costs and benefits.
Rotating sector study of the gas phase photochlorination of 2,2-dichloro-1,1,1-trifluoroethane

The rate constant for the combination of 2,2-dichloro-1,1,1-trifluoroethyl radicals has been measured by applying the rotating sector technique to the gas phase photochlorination of 2,2-dichloro-1,1,1-trifluoroethane at 315°K. The observed value is 6.89 × 1012 cc/mole.sec. This value is in excellent agreement with measurements by Wampler and Kuntz which yielded a temperature-independent value of 6.6 × 1012 cc/mole.sec. The measurement by Wampler and Kuntz was determined from the photochemical system (CF3CCl3 + C-C6H12 + hν). The Arrhenius parameters for the reaction CF3CCl2· + Cl2 CF3CCl3 + Cl were found to be given by the expression log k3 = 12.10 − 5830/2.3RT (units in mole, cc, and sec). This is a relatively high activation energy for a chlorination reaction and makes the reaction ever slower than the chlorination of chloroform.
Invariant effective actions, cohomology of homogeneous spaces and anomalies

Abstract We construct the most general local effective actions for Goldstone boson fields associated with spontaneous symmetry breakdown from a group G to a subgroup H. In a preceding paper, it was shown that any G-invariant term in the action, which results from a non-invariant Lagrangian density, corresponds to a non-trivial generator of the de Rham cohomology classes of G/H. Here, we present an explicit construction of all the generators of this cohomology for any coset space G/H and compact, connected group G. Generators contributing to actions in 4-dimensional space-time arise either as products of generators of lower degree such as the Goldstone-Wilczek current, or are of the Wess-Zumino-Witten type. The latter arise if and only if G has a non-zero G-invariant symmetric d-symbol, which vanishes when restricted to the subgroup H, i.e. when G has anomalous representations in which H is embedded in an anomaly free way. Coupling of additional gauge fields leads to actions whose gauge variation coincides with the chiral anomaly, which is carried here by Goldstone boson fields at tree level. Generators contributing to actions in 3-dimensional space-time arise as Chem-Simons terms evaluated on connections that are composites of the Goldstone field.
The Physical Conditions for Massive Star Formation: Dust Continuum Maps and Modeling

Fifty-one dense cores associated with water masers were mapped at 350 μm. These cores are very luminous, 103 < Lbol/L☉ < 106, indicative of the formation of massive stars. Dust continuum contour maps, radial intensity profiles, and photometry are presented for these sources. The submillimeter dust emission peak is, on average, nearly coincident with the water maser position. The spectral energy distributions and normalized radial profiles of dust continuum emission were modeled for 31 sources using a one-dimensional dust radiative transfer code, assuming a power-law density distribution in the envelope, n = nf(r/rf)-p. The best-fit density power-law exponent, p, ranged from 0.75 to 2.5 with p = 1.8 ± 0.4, similar to the mean value found recently by Beuther and coworkers in a large sample of massive star-forming regions. The mean value of p is also comparable to that found in regions forming only low-mass stars, but nf is over 2 orders of magnitude greater for the massive cores. The mean p is incompatible with a logatropic sphere (p = 1), but other star formation models cannot be ruled out. Different mass estimates are compared and mean masses of gas and dust are reported within a half-power radius determined from the dust emission, log M(< rdec) = 2.0 ± 0.6, and within a radius where the total density exceeds 104 cm-3, log M(< rn) = 2.5 ± 0.6. Evolutionary indicators commonly used for low-mass star formation, such as Tbol and Lbol/Lsmm, may have some utility for regions forming massive stars. Additionally, for comparison with extragalactic star formation studies, the luminosity-to-dust mass ratio is calculated for these sources, Lbol/MD = 1.4 × 104 L☉/M☉, with a method most parallel to that used in studies of distant galaxies. This ratio is similar to that seen in high-redshift starburst galaxies.
A Semantic Web data retrieval implementation with an adaptive model for supporting agent decision structures

This paper proposes an adaptive learning approach that yields decision models that can be applied by a transactions agent. This model can learn effectively with a variety of data distributions. This research uses the Semantic Web as a data access approach. The Semantic Web is a method that sellers can use to publish semantically meaningful information on Websites so automated applications can reliably access that information. We implemented a Semantic Web composed of 30 vendors' Web pages and a spider to search those pages to obtain product and vendor information. This information was used to train a learning agent, which then provided a decision model to a transaction agent.
Asthma in the elderly: The role of exhaled nitric oxide measurements

Asthma in the elderly is poorly understood because only a small minority of asthma studies have investigated this patients group. Fractional exhaled nitric oxide (FENO) has been extensively studied in children and adults with asthma, but little is known about FENO in elderly asthmatics. We studied the role of serial measurements of FENO in elderly subjects with asthma. Thirty stable asthmatics 65 years old and older were followed for one year with evaluations at baseline and every three months. We looked for associations between FENO and subjects' demographics, comorbidities, asthma treatment, spirometric values and asthma control test (ACT) scores. FENO was not elevated in our study subjects throughout the study period (mean < 30 ppb). FENO significantly increased and FEV1% decreased between first and last study visit, while ACT scores and steroid dose remained unchanged. No significant correlation was found between FENO and FEV1/FVC, other spirometric values, inhaled steroid dose or ACT scores at any time point. No associations of FENO were found with age, sex, body mass index (BMI), atopic status, disease duration, presence of rhinitis or gastroesophageal reflux disease (GERD), or other medications used. Moderate asthma exacerbations did not consistently cause an increase of FENO. In stable elderly asthmatic patients, FENO was not elevated and did not correlate with subjects' demographics, comorbidities, treatment, symptoms or spirometric values. Routine measurements of FENO may not be clinically valuable in elderly asthmatics.
Interval bounds on the solutions of semi-explicit index-one DAEs. Part 1: analysis

This article presents two methods for computing interval bounds on the solutions of nonlinear, semi-explicit, index-one differential-algebraic equations (DAEs). Part 1 presents theoretical developments, while Part 2 discusses implementation and numerical examples. The primary theoretical contributions are (1) an interval inclusion test for existence and uniqueness of a solution, and (2) sufficient conditions, in terms of differential inequalities, for two functions to describe componentwise upper and lower bounds on this solution, point-wise in the independent variable. The first proposed method applies these results sequentially in a two-phase algorithm analogous to validated integration methods for ordinary differential equations. The second method unifies these steps to characterize bounds as the solutions of an auxiliary system of DAEs. Efficient implementations of both are described using interval computations and demonstrated on numerical examples.
A facile three-step synthesis of 1,2-amino alcohols using the Ellman homochiral tert-butylsulfinamide

Abstract Addition of organometallic reagents to tert -butylsulfinimines derived from tert -butyldimethylsiloxyacetaldehyde stereoselectively generates protected 1,2-amino alcohols. Removal of the acid labile protecting groups affords amino alcohols in high yield. The predominant diastereomer is opposite to that predicted by the traditional Ellman model; therefore, a chelation model invoking rapid E / Z isomerization of the imine is proposed to rationalize the observed selectivity.
Geometry of scattering at planckian energies

Abstract We present an alternative derivation and geometrical formulation of Verlinde topological field theory, which may describe scattering at center of mass energies comparable with or larger than the Planck energy. A consistent truncation of (3 + 1) dimensional Einstein action is performed using the standard geometrical object, like tetrads and spin connections. The resulting topological invariant is given in terms of differential forms.
Pearling and Pinching: Propagation of Rayleigh Instabilities

A new class of propagating fronts is proposed in which a spreading instability evolves through a singular configuration before saturating. As an example, we examine the viscous Rayleigh instability of a stationary fluid column, using the marginal stability criterion to estimate the front velocity, front width, and the selected wavelength in terms of the surface tension and viscosity contrast. Systems that may display this phenomenon include droplets elongated in extensional flows, capillary bridges, liquid crystal tethers, and viscoelastic jets. The related problem of propagation in Rayleigh-like systems that do not fission is also considered.
Distant galaxy clusters identified from optical background fluctuations

We present the first high-redshift (0.3 < z < 1.1) galaxy clusters found by systematically identifying optical low surface brightness fluctuations in the background sky. Using spectra obtained with the Keck I telescope and I-band images from the Palomar 1.5 m telescope, we conclude that at least eight of the 10 candidates examined are high-redshift galaxy clusters. The identification of such clusters from low surface brightness fluctuations provides a complement to classic selection methods based on overdensities of resolved galaxies and enables us to search efficiently for rich high-redshift clusters over large areas of the sky. The detections described here are the first in a survey that covers a total of nearly 140 deg2 of the sky and should yield, if these preliminary results are representative, over 300 such clusters.
Assessing the scholarly impact of information studies: A tale of two citation databases—Scopus and Web of Science

This study uses citations, from 1996 to 2007, to the work of 80 randomly selected full-time, information studies (IS) faculty members from North America to examine differences between Scopus and Web of Science in assessing the scholarly impact of the field focusing on the most frequently citing journals, conference proceedings, research domains and institutions, as well as all citing countries. Results show that when assessment is limited to smaller citing entities (e.g., journals, conference proceedings, institutions), the two databases produce considerably different results, whereas when assessment is limited to larger citing entities (e.g., research domains, countries), the two databases produce very similar pictures of scholarly impact. In the former case, the use of Scopus (for journals and institutions) and both Scopus and Web of Science (for conference proceedings) is necessary to more accurately assess or visualize the scholarly impact of IS, whereas in the latter case, assessing or visualizing the scholarly impact of IS is independent of the database used. © 2009 Wiley Periodicals, Inc.
Smoothing Solutions to Initial-Boundary Problems for First-Order Hyperbolic Systems

We consider initial-boundary problems for general linear first-order strictly hyperbolic systems with local or nonlocal nonlinear boundary conditions. While boundary data are supposed to be smooth, initial conditions can contain distributions of any order of singularity. It is known that such problems have a unique continuous solution if the initial data are continuous. In the case of strongly singular initial data we prove the existence of a (unique) delta wave solution. In both cases, we say that a solution is smoothing if it eventually becomes k-times continuously differentiable for each k. Our main result is a criterion allowing us to determine whether or not the solution is smoothing. In particular, we prove a rather general smoothingness result in the case of classical boundary conditions.
Relational Costs and the Production of Social Capital: Evidence from Carpooling

This article posits that individuals can more easily form social connections with people if they are of the same race. If true, the greater the incidence among his neighbours of persons of his race, the more likely an individual is to make neighbourhood social capital connections and the more likely he is to engage in activities which require it. The article tests this idea using an indicator of individual social capital never previously studied: whether the person uses a carpool to get to work. The analysis accounts for fixed differences across neighbourhoods, and a variety of extensions address possible differential racial sorting into neighbourhoods. The evidence strongly supports the article's hypothesis.
Target Space Duality between Simple Compact Lie Groups and Lie Algebras under the Hamiltonian Formalism: I. Remnants of Duality at the Classical Level

It has been suggested that a possible classical remnant of the phenomenon of target-space duality (T-duality) would be the equivalence of the classical string Hamiltonian systems. Given a simple compact Lie groupG with a bi-invariant metric and a generating function Γ suggested in the physics literature, we follow the above line of thought and work out the canonical transformation Φ generated by Γ together with an Ad-invariant metric and a B-field on the associated Lie algebra\(\mathfrak{g}\) ofG so thatG and\(\mathfrak{g}\) form a string target-space dual pair at the classical level under the Hamiltonian formalism. In this article, some general features of this Hamiltonian setting are discussed. We study properties of the canonical transformation Φ including a careful analysis of its domain and image. The geometry of the T-dual structure on\(\mathfrak{g}\) is lightly touched. We leave the task of tracing back the Hamiltonian formalism at the quantum level to the sequel of this paper.
Laminar and turbulent comparisons for channel flow and flow control

A formula is derived that shows exactly how much the discrepancy between the volume flux in laminar and in turbulent flow at the same pressure gradient increases as the pressure gradient is increased. We compare laminar and turbulent flows in channels with and without flow control. For the related problem of a fixed bulk-Reynolds-number flow, we seek the theoretical lowest bound for skin-friction drag for control schemes that use surface blowing and suction with zero-net volume-flux addition. For one such case, using a crossflow approach, we show that sustained drag below that of the laminar-Poiseuille-flow case is not possible. For more general control strategies we derive a criterion for achieving sublaminar drag and use this to consider the implications for control strategy design and the limitations at high Reynolds numbers.
How Has Regulation FD Affected the Operations of Financial Analysts

In this paper, we analyze how financial analysts generate information, make decisions about firm coverage, and try to maintain their forecasting accuracy after the passage of Regulation Fair Disclosure (“Reg FD”). Using the model developed by Barron, Kim, Lim, and Stevens 1998, we find that analysts are investing more effort in idiosyncratic information discovery. In order to do this, individual analysts appear to be reducing coverage for well-followed firms while increasing coverage of firms that were less followed prior to Reg FD. Analysts who had preferential links with firms that they covered, such as analysts from large brokerage houses, tend to have greater forecast accuracy in the pre-FD period. However, these analysts are unable to sustain their forecasting superiority in the post-FD period, which suggests that there has been a leveling of the information playing field among analysts. Overall, our results reflect a trend toward greater reliance on idiosyncratic information discovery on part of the financial analysts.
Toric arc schemes and quantum cohomology of toric varieties

We describe the quantum cohomology ring of a toric Fano variety $X$ in terms of the usual topological cohomology ring for an auxiliary infinite-dimensional scheme. This scheme is a part of an algebro-geometric model for the universal cover of the space of free loops with values in $X$.
Finite element methods in fracture mechanics

Finite-element methodology specific to the analysis of fracture mechanics problems is reviewed. Primary emphasis is on the important algorithmic developments which have enhanced the numerical modeling of fracture processes. Methodologies to address elastostatic problems in two and three dimensions, elastodynamic problems, elastoplastic problems, special considerations for three-dimensional nonlinear problems, and the modeling of stable crack growth are reviewed. In addition, the future needs of the fracture community are discussed and open questions are identified.
The Three Gap Theorem and Riemannian geometry

The classical Three Gap Theorem asserts that for a natural number n and a real number p, there are at most three distinct distances between consecutive elements in the subset of [0,1) consisting of the reductions modulo 1 of the first n multiples of p. Regarding it as a statement about rotations of the circle, we find results in a similar spirit pertaining to isometries of compact Riemannian manifolds and the distribution of points along their geodesics.
The instanton/sphaleron mechanism of prompt gluon production in high energy heavy ion collisions at RHIC

Abstract We argue that if the growing part of hadron–hadron cross section (described phenomenologically by the supercritical soft Pomeron) is due to instanton/sphaleron mechanism, one should find certain qualitative features of the produced cluster which differ from the usual string fragmentation. Furthermore, we suggest that this mechanism should be even more important for heavy ion collisions in the RHIC energy domain. Large number of parton–parton collisions should result in hundreds of produced sphaleron-like gluomagnetic clusters per unit rapidity. Unlike perturbative gluons (or mini-jets), these classically unstable objects promptly decay into several gluons and quarks in mini-explosions, leading to very rapid entropy generation. This may help to explain why the QGP seem to be produced at RHIC so early. We further argue that this mechanism cannot be important at higher energies (LHC), where perturbative description should apply.
Identification of cylindrical shells with sets of reinforcing ribs by their acoustic Bragg diffraction (grating) patterns

Abstract The authors present a basic study of the acoustic Bragg diffraction patterns produced by gratings with various types of slits, which are insonified by (monochromatic) acoustic waves of various frequencies. Given the spacing in between the slits, the (Bragg) angular diffraction pattern generated by the grating can be predicted by the method of physical optics (acoustics), and can be numerically evaluated for gratings with either uniformly or irregularly spaced slits. It has been already established that the diffraction patterns of planar gratings can be used (i.e. Brill, D. & Gaunaurd, G. C., J. Acoust, Soc. Amer., 93 (1993) 71–79) to model the far-field scattering patterns produced by thin, cylindrical, elastic shells in water that have many reinforcing ribs. Varying the size and slit spacing (i.e. the ribs), the diffraction pattern becomes distorted, and for very irregularly spaced cases the distortion is substantially asymmetric and noticeable. In some instances it is also possible to relate the resulting diffraction pattern — which can be generated by computer for any conceivable configuration — to the grating size and the regular or irregular type of separations in between its slits. This serves to identify the type of grating that generated the pattern, a finding of importance in the area of underwater acoustic target recognition. A number of graphs are shown to illustrate these points.
HIDING THE EXISTENCE OF A FAMILY SYMMETRY IN THE STANDARD MODEL

If a family symmetry exists for the quarks and leptons, the Higgs sector is expected to be enlarged to be able to support the transformation properties of this symmetry. There are, however, three possible generic ways (at tree level) of hiding this symmetry in the context of the Standard Model with just one Higgs doublet. All three mechanisms have their natural realizations in the unification symmetry E6 and one in SO(10). An interesting example based on SO(10)×A4 for the neutrino mass matrix is discussed.
Lévy flights over quantum paths

Abstract An impact of integration over the paths of the Levy flights on the quantum mechanical kernel has been studied. Analytical expression for a free particle kernel has been obtained in terms of the Fox H -function. A new equation for the kernel of a particle in the box has been found. New general results include the well known quantum formulae for a free particle kernel and particle in box kernel.
Cosmological solutions of type II string theory

Abstract We study cosmological solutions of type II string theory with a metric of the Kaluza-Klein type and nontrivial Ramond-Ramond forms. It is shown that models with only one form excited can be integrated in general. Moreover, some interesting cases with two nontrivial forms can be solved completely since they correspond to Toda models. We find two types of solutions corresponding to a negative time superinflating phase and a positive time subluminal expanding phase. The two branches are separated by a curvature singularity. Within each branch the effect of the forms is to interpolate between different solutions of pure Kaluza-Klein theory.
Synthesis and evaluation of 2-(arylamino)imidazoles as α2-adrenergic agonists

A series of 2-(arylamino)imidazoles was synthesized and evaluated for activity at α1- and α2-adrenoceptors. This class of agents has been shown to have potent and selective agonist activity at the α2-adrenoceptors. The most potent member of this class, 2-[(5-methyl-1,4-benzodioxan-6-yl)amino]imidazole, proved efficacious for the reduction of intraocular pressure upon topical administration and for the reduction of blood pressure upon intravenous administration. During the course of our studies, we developed a new reagent that allowed rapid assembly of the target compounds. This reagent, N-(2,2-diethoxyethyl)carbodiimide, was convenient to prepare and was stable under low-temperature storage conditions.
Determination of Systemic Vascular Resistance by a Noninvasive Technic

Measurement of systemic vascular resistance in man currently requires arterial and venous cannulation, so that cardiac output and mean arterial blood pressure may be simultaneously determined. This report describes a noninvasive technic for determining systemic vascular resistance (SVRn), utilizing an ultrasonic method for cardiac output measurement, and a combination of sphygmomanometry and external carotid pulse tracing analysis for determination of mean arterial blood pressure. SVRn was measured by this technic in 18 patients and compared with systemic vascular resistance determined by conventional methods at cardiac catheterization (SVRc). There was excellent correlation, with SVRc = 0.865 SVRn+216 and r = 0.85. The sensitivity of the method was verified in studies on 12 normal subjects in whom SVRn while supine (1235 ± 61 dyne-sec-cm–5, mean ± se) was less than SVRn while standing (1416 ± 81, P < 0.01) and greater than SVRn supine after amyl nitrite inhalation (652 ± 41,P < 0.0001). It is concluded t...
Reuse, Recycle, Reweigh: Combating Influenza through Efficient Sequential Bayesian Computation for Massive Data

Massive datasets in the gigabyte and terabyte range combined with the availability of increasingly sophisticated statistical tools yield analyses at the boundary of what is computationally feasible. Compromising in the face of this computational burden by partitioning the dataset into more tractable sizes results in stratified analyses, removed from the context that justified the initial data collection. In a Bayesian framework, these stratified analyses generate intermediate realizations, often compared using point estimates that fail to account for the variability within and correlation between the distributions these realizations approximate. However, although the initial concession to stratify generally precludes the more sensible analysis using a single joint hierarchical model, we can circumvent this outcome and capitalize on the intermediate realizations by extending the dynamic iterative reweighting MCMC algorithm. In doing so, we reuse the available realizations by reweighting them with importance weights, recycling them into a now tractable joint hierarchical model. We apply this technique to intermediate realizations generated from stratified analyses of 687 influenza A genomes spanning 13 years allowing us to revisit hypotheses regarding the evolutionary history of influenza within a hierarchical statistical framework.
On the enumeration of skew Young tableaux

For fixed n and a fixed partition α of k < n we give an explicit formula for the number N(n; α) of standard skew Young tableaux with n squares and shape λ/α for some λ. From this formula the entire asymptotic expansion of N(n; α) as n → ∞ can in principle be computed, generalizing recent work of McKay, Morse, and Wilf. We also give asymptotic formulas for the number fλ/α of standard skew Young tableaux of shape λ/α for α fixed and λ "large."
Compiling path expressions into VLSI circuits

Path expressions were originally proposed by Campbell and Habermann [2] as a mechanism for process synchronization at the monitor level in software. Not surprisingly, they also provide a useful notation for specifying the behavior of asynchronous circuits. Motivated by these potential applications we investigate how to directly translate path expressions into hardware. Our implementation is complicated in the case of multiple path expressions by the need for synchronization on event names that are common to more than one path. Moreover, since events are inherently asynchronous in our model, all of our circuits must be self-timed. Nevertheless, the circuits produced by our construction have are proportional to N · log(N) where N is the total length of the multiple path expression under consideration. This bound holds regardless of the number of individual paths or the degree of synchronization between paths. Furthermore, if the structure of the path expression allows partitioning, the circuit can be laid out in a distributed fashion without additional area overhead.
Reducts of propositional theories, satisfiability relations, and generalizations of semantics of logic programs

Over the years, the stable-model semantics has gained a position of the correct (two-valued) interpretation of default negation in programs. However, for programs with aggregates (constraints), the stable-model semantics, in its broadly accepted generalization stemming from the work by Pearce, Ferraris and Lifschitz, has a competitor: the semantics proposed by Faber, Leone and Pfeifer, which seems to be essentially different. Our goal is to explain the relationship between the two semantics. Pearce, Ferraris and Lifschitz's extension of the stable-model semantics is best viewed in the setting of arbitrary propositional theories. We propose here an extension of the Faber-Leone-Pfeifer semantics, or FLP semantics, for short, to the full propositional language, which reveals both common threads and differences between the FLP and stable-model semantics. We use our characterizations of FLP-stable models to derive corresponding results on strong equivalence and on normal forms of theories under the FLP semantics. We apply a similar approach to define supported models for arbitrary propositional theories, and to study their properties.
Ferrographic Analysis of Wear Debris Generated in Accelerated Rolling Element Fatigue Tests

Ferrographic analysis was used to determine the types and quantities of wear particles generated during accelerated rolling contact fatigue tests. The NASA five-ball rolling contact fatigue tester was used. Ball specimens were made of AMS 5749, a corrosion resistant, high-temperature bearing steel. The lubricant was a super-refined naphthenic mineral oil. Conditions included a maximum Hertz stress of 5.52 × 109 Pa and a shaft speed of 10 000 rpm. Four types of wear particles were observed; normal rubbing wear particles, fatigue spall particles, spheres, and friction polymer. Presented as an American Society of Lubrications Engineers paper at the ASLE/ASME Lubrication Conference in Kansas City, Missouri, October 3–5, 1977
A Multipurpose Frequency-Response Analyzer

Closed loop frequency response analyzer with steepest descent computing procedure to obtain in-phase and quadrature signal components in linear or nonlinear systems
Preview Control for Vehicle Lateral Guidance in Highway Automation

The continuous time deterministic optimal preview control algorithm is applied to the lateral guidance of a vehicle for an automated highway. In the lateral guidance problem, the front wheel steering angle of the vehicle is controlled so that the vehicle follows the center for a lane with small tracking error and maintains good ride quality simultaneously. A preview control algorithm is obtained by minimizing a quadratic performance index which includes terms representing the passenger ride quality as well as the lateral tracking error, each of these terms is multiplied by a frequency dependent weight. It is shown that the optimal preview control law consists of a feedback control term and two feedforward control terms. The feedforward preview control action significantly improves the tracking performance and ride quality. Frequency-domain analyses, as well as numerical simulation results, show the improvements achieved by using the preview control algorithm in both the frequency and time domains.