cssi/SciSciGPT-SciSciNet huggingface dataset:
Precipitation kinetics in solutionized aluminum alloy 2124: Determination by scanning and isothermal calorimetry

Abstract Kinetics and energetics of precipitation in solutionized (SOL) aluminum alloy 2124 have been determined by differential scanning calorimetry (DSC) and differential isothermal calorimetry (DIC). DSC experiments at several temperature scan rates were analyzed by the Kissinger method to give activation energies and rate constants. From the DIC experiments, we obtained kinetics information using a 2-exponential fit, a rate-averaged time constant, and (for GP formation) an Avrami model. It appears that the 2-exponential fit is applicable when two distinct processes contribute to precipitation, while the rate-averaged time constant is appropriate when one process is dominant. Criteria are established for choosing the proper analysis. Activation energies and time constants from DSC and DIC agree fairly well for both GP zone formation and precipitation. Kinetics results for GP zone dissolution in SOL 2124 were obtainable only from DSC experiments. Both calorimetric methods indicate that, after GP zones have formed and dissolved, two mechanisms are involved in precipitation. The results are compared to DSC studies of other workers for similar alloys. TEM studies indicate that the two precipitation mechanisms in alloy 2124 involve formation of S ′ (CuMgAl 2 ) and θ ′ (CuAl 2 ) phases. Δ Q , the heat evolved during GP zone formation and precipitation, was measured isothermally over the 30–300°C range. At the temperature of maximum GP zone formation rate (∼70°C), Δ Q ≈−14.7 J/g; at the precipitation maximum (∼270°C) Δ Q ≈−27.2 J/g.
An efficient, nonlinear stability analysis for detecting pattern formation in reaction diffusion systems

Reaction diffusion systems are often used to study pattern formation in biological systems. However, most methods for understanding their behavior are challenging and can rarely be applied to complex systems common in biological applications. I present a relatively simple and efficient, nonlinear stability technique that greatly aids such analysis when rates of diffusion are substantially different. This technique reduces a system of reaction diffusion equations to a system of ordinary differential equations tracking the evolution of a large amplitude, spatially localized perturbation of a homogeneous steady state. Stability properties of this system, determined using standard bifurcation techniques and software, describe both linear and nonlinear patterning regimes of the reaction diffusion system. I describe the class of systems this method can be applied to and demonstrate its application. Analysis of Schnakenberg and substrate inhibition models is performed to demonstrate the methods capabilities in simplified settings and show that even these simple models have nonlinear patterning regimes not previously detected. The real power of this technique, however, is its simplicity and applicability to larger complex systems where other nonlinear methods become intractable. This is demonstrated through analysis of a chemotaxis regulatory network comprised of interacting proteins and phospholipids. In each case, predictions of this method are verified against results of numerical simulation, linear stability, asymptotic, and/or full PDE bifurcation analyses.
Accountability and auditors' materiality judgments: The effects of differential pressure strength on conservatism, variability, and effort

Abstract This study investigates the effects of differential accountability pressure strength on auditors’ materiality judgments. We evaluate whether incremental levels of accountability (i.e., review, justification, feedback) increase judgment conservatism, decreases judgment variability, and increases effort. One hundred sixty auditors participated in a between-subjects experiment that included a planning materiality task and a proposed audit adjustment materiality task. As predicted, auditors under higher levels of accountability pressure (i.e., justification, feedback) provided more conservative materiality judgments and had less judgment variability than auditors under lower levels of pressure (i.e., review, anonymity). The results also indicate that accountability strength was positively related to the amount of time spent on the task, explanation length, and consideration of qualitative materiality factors. Finally, the results show that use of a planning materiality decision aid influenced the accountability effects for the planning materiality judgment. These judgments were more conservative and less variable when the planning materiality decision aid was available. We consider implications for research, practice, and policy in the context of the study’s limitations.
Valuating Surface Surveillance Technology for Collaborative Multiple-Spot Control of Airport Departure Operations

Airport departure operations are a source of airline delays and passenger frustration. Excessive surface traffic is a cause of increased controller and pilot workload. It is also a source of increased emissions and delays, and it does not yield improved runway throughput. Leveraging the extensive past research on airport departure management, this paper explores the environmental and safety benefits that improved surveillance technologies can bring in the context of gate- or spot-release strategies. This paper shows that improved surveillance technologies can yield a 4%-6% reduction of the average number of aircraft on the taxiway system during congested operations, and therefore emissions, in addition to the savings currently observed by implementing threshold-based metering strategies under evaluation at Boston's Logan Airport and other busy airports during congested periods. These calculated benefits contrast sharply with our previous work, which relied on simplified airport ramp areas with a single departure spot and where fewer environmental and economic benefits of advanced surface surveillance systems could be established. Our work is illustrated by its application to New York's LaGuardia and Seattle-Tacoma airports in Washington.
Matrix black holes

Four- and five-dimensional extremal black holes with nonzero entropy have simple presentations in M-theory as gravitational waves bound to configurations of intersecting M-branes. We discuss realizations of these objects in matrix models of M-theory, investigate the properties of 0-brane probes, and propose a measure of their internal density. A scenario for black-hole dynamics is presented.
Conceptual design of a fast soft x-ray stellar polarimeter

Multilayer coatings make it possible to create soft x-ray (0.25 keV) optics with large graze angles which are necessary for designing efficient polarimeters. If the detector is placed out of focus, then stellar images will take the shape of the front aperture, which would show intensity variations if the source is polarized. Two basic designs are considered. The first uses a single parabolic optic with graze angles from 25 degree(s) to 40 degree(s) and the second uses a Cassegrain telescope with angles centered at 45 degree(s). The former gives higher reflectivity at the expense of wide-field imaging, which may be sacrificed when the source region is not crowded, while the second telescope allows for off-axis use as a spectropolarimeter but has reduced throughput. A simple imaging proportional counter would be used as a detector and the overall sensitivity of the first design would be high enough to measure the polarization of the bright BL Lac object, PKS 2155-304, to an accuracy of 3% during a rocket flight. A small satellite would be capable of measuring several hundred polarizations with an uncertainty of 1% per year.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Velocity-Density Correlations and Favre Averages Measured in a Premixed Turbulent Flame

Abstract Laser velocimetry and Rayleigh scattering diagnostics are applied simultaneously to measure velocity-density correlations, Favre averaged velocities, and the conditioned velocities of reactants and products in a premixed turbulent flame. Details of the experimental procedure are described, as well as the effects of velocity biasing. The flamelets within the flame are visualized and a significant amount of “flame generated turbulence” is measured. A number of assumptions in the Bray-Moss-Libby theory are found to be valid which is in agreement with several previous experiments that employed different diagnostics. However, one difference between the measurements and theory is that the velocity PDF of products is found to be non-Gaussian because a significant amount of low speed products exist within the flame. The low speed products are believed to be due to non-uniform acceleration induced by the curved flamelets that are observed. This non-uniform acceleration appears to represent an additional s...
On higher analogs of topological complexity

Abstract Farber introduced a notion of topological complexity TC ( X ) that is related to robotics. Here we introduce a series of numerical invariants TC n ( X ) , n = 2 , 3 , … , such that TC 2 ( X ) = TC ( X ) and TC n ( X ) ⩽ TC n + 1 ( X ) . For these higher complexities, we define their symmetric versions that can also be regarded as higher analogs of the symmetric topological complexity.
Robust Control of Flexible Structures Using Multiple Shape Memory Alloy Actuators

The design and implementation of control strategies for large, flexible smart struc tures presents challenging problems. To demonstrate the capabilities of shape-memory-alloy (SMA) actuators, we have designed and fabricated a three-mass test article with multiple shape-memory- alloy, NiTiNOL, actuators. Both force and moment actuators were implemented on the structure to examine the effects of control structure interaction and to increase actuation force. These SMA actu ators exhibit nonlinear effects due to dead band and saturation. The first step in the modeling process was the experimental determination of the transfer function matrix derived from frequency response data. A minimal state space representation was determined based on this transfer function matrix. Finally, a reduced order state space model was derived from the minimal state space representation. The simplified analytical models were compared with models developed by structural identification techniques based on vibration test data.From t...
Inverse Obstacle Problem for the Non-Stationary Wave Equation with an Unknown Background

We consider boundary measurements for the wave equation on a bounded domain M ⊂ ℝ2 or on a compact Riemannian surface, and introduce a method to locate a discontinuity in the wave speed. Assuming t...
Mixed‐Alkali Effect in Low‐Alkali Germanate Glasses

Direct-current conductivities of mixed-alkali Na2O-K2O-GeO2 glasses with ∼0.02 mol% total alkali were investigated. No minima in conductivity isotherms were indicated as K2O is substituted for Na2O. However, a conductivity-suppressing effect with the-addition of K2O to Na20-GeO2 glass was demonstrated, from the comparison with the conductivity ofNa2O-GeO2 glasses of varied sodium content (0.0079∼0.30 mol% Na2O.
A Closer look at the elementary fermions

Although there have been many experimental and theoretical efforts to measure and interpret small deviations from the standard model of particle physics, the gap that the model leaves in understanding why there are only three generations of the elementary fermions, with hierarchical masses, has not received the attention it deserves. I present here an attempt to fill this gap. Although our findings are mostly only qualitative, they nevertheless may be of heuristic value. Rules concerning the elementary fermions, some previously known and some new, lead to a number of conclusions and questions that seem worth pursuing. Some clarify the standard model, and others suggest possible modifications, the implications of which are discussed.
Discrete Lie Advection of Differential Forms

In this paper, we present a numerical technique for performing Lie advection of arbitrary differential forms. Leveraging advances in high-resolution finite-volume methods for scalar hyperbolic conservation laws, we first discretize the interior product (also called contraction) through integrals over Eulerian approximations of extrusions. This, along with Cartan’s homotopy formula and a discrete exterior derivative, can then be used to derive a discrete Lie derivative. The usefulness of this operator is demonstrated through the numerical advection of scalar fields and 1-forms on regular grids.
Sovereignty, the WTO, and Changing Fundamentals of International Law

Part I. Challenges to International Law Fundamental Assumptions: 1. Introduction: International law and international economic law in the interdependent world of the twenty-first century 2. The real world impinges on international law: exploring the challenges to the fundamental assumptions of international law and institutions 3. Sovereignty modern: a new approach to an outdated concept Part II. The WTO: 4. The WTO as international organization: institutional evolution, structure and key problems 5. The WTO dispute settlement system Part III. The Search for Solutions: 6. Policy, analytical approaches and thought experiments 7. Illustrative applications 8. Perspectives, implications, and some conclusions.
Detecting flat normal cones using Segre classes

Abstract Given a flat, projective morphism Y → T from an equidimensional scheme to a nonsingular curve and a subscheme Z of Y , we give conditions under which specialization of the Segre class s ( N Z Y ) of the normal cone of Z in Y implies flatness of the normal cone. We apply this result to study when the relative tangent star cone of a flat family is flat.
Astrophysical tests for radiative decay of neutrinos and fundamental physics implications

The radiative lifetime tau for the decay of massious neutrinos was calculated using various physical models for neutrino decay. The results were then related to the astrophysical problem of the detectability of the decay photons from cosmic neutrinos. Conversely, the astrophysical data were used to place lower limits on tau. These limits are all well below predicted values. However, an observed feature at approximately 1700 A in the ultraviolet background radiation at high galactic latitudes may be from the decay of neutrinos with mass approximately 14 eV. This would require a decay rate much larger than the predictions of standard models but could be indicative of a decay rate possible in composite models or other new physics. Thus an important test for substructure in leptons and quarks or other physics beyond the standard electroweak model may have been found.
Surgical Approach and Oncologic Outcomes Following Multidisciplinary Management of Retrorectal Sarcomas

Background. Retrorectal sarcomas are rare, and limited data are available on oncologic outcomes following surgery. Our aim was to evaluate outcomes in this patient population at our institution. Materials and Methods. All patients who underwent surgical resection of a malignant retrorectal/presacral sarcoma between 1985 and 2005 were identified. Data analyzed included demographics, histopathologic diagnosis, surgical morbidity and mortality, use of adjuvant therapy, local and distant recurrence, and survival. Results. A total of 37 patients were identified (20 males) with a median age of 49 years (range, 22–81 years). The most common histopathologic diagnosis was malignant peripheral nerve sheath tumor (n = 8). Also, 22 tumors were high grade and 15 were low grade. Surgical margin status was R0 in 31 patients and R1 in 6. Adjuvant therapy was given to 26 patients. Postoperative morbidity and mortality was 57% and 3%, respectively. Median length of follow-up in 16 patients alive at last contact was 4.7 years. The 5-year survival free of local (LDFS), distant (DDFS), and local or distant recurrence (DFS) was 51, 58, and 39%, respectively. Patient survival at 2, 5, and 10 years was 75, 55, and 47%, respectively. Disease-free survival was not significantly associated with gender (P = .16), primary vs secondary (P = .94), R0 vs R1 resection (P = .26), low vs high tumor grade (P = .17), or the use of surgery with or without adjuvant therapy (P = .33). Conclusions. Retrorectal sarcomas are often high grade and locally advanced. Most tumors are resectable with free margins, and long-term survival may be possible in up to one-half of patients following an aggressive surgical approach.
The effects of regulatory and contracting costs on banks’ choice of accounting method for other postretirement employee benefits

Abstract This paper examines banks’ choice of accounting methods in a new regulatory environment that more closely ties regulatory monitoring to GAAP numbers. The study finds that banks’ choice of the implementation method for SFAS 106 is consistent with an attempt to balance the increased regulatory costs with earnings management benefits. Moreover, banks strategically chose the adoption timing of both SFAS 106 and SFAS 109 to further reduce regulatory costs. The implementation method choice is consistent with a portfolio approach where managers simultaneously consider the existing discretionary accrual levels vis-a-vis the financial reporting effects of impending accounting standards.
The Triumphant Consumer? VoIP, “Little Smart,” and Telecom Service Reform in China

Can innovations in communications technology dilute the power of China's authoritarian government? When Voice over Internet Protocol (VOIP) and Little Smart (xiao lingtong) personal handyphone service first broke into China's market, they were illegal. However, consumers loved the services and demanded more. Using VOIP consumers can make cheap long distance calls. Little Smart introduced an old technology to China that makes mobile phone services more affordable to the masses. Eventually, the Ministry of Information Industry (MII), which initially had banned both, then legalized both under pressure from other parts of the government and from consumers. The planned economy is breaking down and the government is constructing piecemeal the foundation for a rules-based economy.
Semivariance decomposition of country-level returns

Abstract A methodology for decomposing the below-mean semivariance into systematic and unsystematic components is introduced. The decomposition of variance and semivariance of asset returns is presented for forty-four country-level indexes. The proportion of risk explained for country-level returns in the Downside CAPM framework is higher than in the CAPM framework. On average for all markets, global systematic risk, as a proportion of total risk, is 42% in the CAPM and 56% in the Downside CAPM. A strong role for semivariance and downside beta is found in explaining the cross-section of country returns. Although skew is highly correlated to semivariance, no cross-sectional confirmation of the role of skew as a priced risk or in explaining the downside risk is identified.
Limits on Eclipses of the Pre-Main-Sequence Star KH 15D in the First Half of the 20th Century

Over the last decade, the pre-main-sequence star KH 15D has exhibited periodic eclipses that are surprisingly deep (~3 mag) and long-lasting (~40% of the 48.4 day period). The cause of the eclipses is unknown, but it could be a feature in a nearly edge-on protoplanetary disk. Here we report on an analysis of archival photographs of KH 15D from the Harvard College Observatory plate collection, most of which were taken during the years 1913-1951. During this time range, the data are consistent with no eclipses; the duty cycle of 1 mag eclipses was less than 20%. The decadal timescale of this change in eclipse behavior is compatible with the expected timescale of protoplanet/disk interactions. Archival images from more recent epochs should reveal the onset of the eclipses.
Experimental Characterization of Thermal Creak Response of Deployable Space Structures

The phenomenon of thermal creak in deployable space structures is investigated. Thermal creak is a disturbance which occurs when thermally-induced stress in a statically indeterminate structure is suddenly released via a slip internal to a joint or other frictional mechanism. A representative deployable truss is suspended in a thermal chamber, where its temperature is cycled, in order to determine whether thermal creak occurs in such a structure. High-bandwidth accelerometers distributed across the truss are used as the primary sensors for detecting structural events. Thermal creaks are found to occur during the thermal transients, before steady-state is achieved throughout the truss. The truss response to the impulsive and broadband disturbances is characterized in both the time and frequency domains, The transient response exhibits telltale signs of structural behavior, including multi-mode or dominant-mode excitation, and reasonable modal damping in the time decay. An analytical model of the thermal creak mechanism is presented which qualitatively captures the structural behavior.
Potential crash reduction benefits of shoulder rumble strips in two-lane rural highways.

This paper reports the findings from a study aimed at examining the effectiveness of shoulder rumble strips in reducing run-off-the-road (ROR) crashes on two-lane rural highways using the empirical Bayes (EB) before-and-after analysis method. Specifically, the study analyzed the effects of traffic volume, roadway geometry and paved right shoulder width on the effectiveness of shoulder rumble strips. The results of this study demonstrate the safety benefits of shoulder rumble strips in reducing the ROR crashes on two-lane rural highways using the state of Idaho 2001–2009 crash data. This study revealed a 14% reduction in all ROR crashes after the installation of shoulder rumble strips on 178.63 miles of two-lane rural highways in Idaho. The results indicate that shoulder rumble strips were most effective on roads with relatively moderate curvature and right paved shoulder width of 3 feet and more.
Ion-exchange-metal composite artificial muscle actuator load characterization and modeling

Reported in this work are load characterization of electroactive films made out of polymeric ion-exchange membrane materials treated with a noble metal such as platinum. Load characterization under oscillating voltage input on the resulting composite samples was then performed using a PC-platform data acquisition system, variable signal generator, amplifier and load cells. For fixed signal frequency, various shape signals at low voltage amplitudes were then applied and the corresponding induced forces measured by the load cells and recorded via the data acquisition setup. The applied input signals consisted of sinusoid, square, saw tooth, and triangular form in order to observe the difference in behavior and the resulting output forces of the actuators. A briefdescription ofa proposed theory for this type ofactuator was then discussed. The results showed that these actuators exhibit good force to weight characteristics in the presence oflow applied voltages.
A Divergent Diastereoselective Approach to Bicyclopropanes

Abstract The diastereoselective cyclopropanation of three stereoisomerically unique vinylcyclopropanes was studied. The selective preparation of six stereoisomeric bicyclopropanes was accomplished by an iterative reagent-controlled process. With the exception of the cis-syntrans-bicyclopropane, all isomers can be prepared in a diastereomeric excess of greater than 5:1.
Cupid is doomed: An analysis of the stability of the inner uranian satellites

Abstract We have explored the stability of the inner uranian satellites using simulations based on the most recent observational data. We find that, across a wide range of mass assumptions, the system is unstable, resulting in the eventual crossing of orbits and probable subsequent collision of moons. Cupid and Belinda are usually the first satellites to cross orbits, and they do so on a time scale of 103–107 years. Cressida and Desdemona are generally the next pair to cross, on a time scale of 105–107 years. We show that the crossing times are highly sensitive to initial conditions and that Cupid’s instability is related to its resonant interactions with Belinda. We also show that a previously discovered power law, which relates orbit crossing time to satellite mass, is valid across a wide range of masses. We generalize the power law to handle two unstable orbital pairs with overlapping lifetimes and show that it can be used to extend the time span of studies of orbital stability in a computationally efficient manner. Our results suggest that the current uranian satellite system is in transition and that the moons will continue to collide and reaccrete for the foreseeable future.
Noise and Dynamical Pattern Selection

In pattern-forming systems, such as Rayleigh-Benard convection or directional solidification, a large number of linearly stable, patterned steady states exist when the basic, simple steady state is unstable. Which of these steady states will be realized in a given experiment appears to depend on unobservable details of the system's initial conditions. We show, however, that weak, Gaussian white noise drives such a system toward a preferred wave number which depends only on the system parameters and is independent of initial conditions. We give a prescription for calculating this wave number, analytically near the onset of instability and numerically otherwise.
Generalized parton distributions

An introductory review of generalized parton distributions (GPDs) is given. The structure of hadrons is the fundamental physics to be accessed via GPDs. GPDs describe hadronic structure on the quark-gluon level and provide a 3-dimensional picture (tomography) of hadronic structure. GPDs adequately reflect the quantum-field nature of quantum chromodynamics (QCD) (correlations, interference). They also provide new insights into spin structure of hadrons (spin-flip distributions, orbital angular momentum). GPDs are sensitive to chiral symmetry breaking effects, a fundamental property of QCD. Furthermore, GPDs unify existing ways of describing hadronic structure. The GPD formalism provides nontrivial relations between different exclusive reactions and also between exclusive and inclusive processes.
Stopping: from peripheral to central nuclear collisions at the SPS

Abstract New results on baryon stopping at the CERN SPS, measured by the inclusive net proton (p- p ) rapidity distribution, are presented for centrality selected Pb+Pb and p+Pb, as well as minimum bias p+p collisions. A smooth evolution in the degree of stopping is observed when going from small to large systems, with the greatest stopping in the most central p+Pb collisions. On the other hand, longitudinal distributions of produced particles vary little with the size of the system, and the total yield of pions scales approximately with the number of participating nucleons.
Studies of the Relativistic Binary Pulsar PSR B1534+12. I. Timing Analysis

We have continued our long-term study of the double neutron star binary pulsar PSR B1534+12, using new instrumentation to make very high precision measurements at the Arecibo Observatory. We have significantly improved our solution for the astrometric, spin, and orbital parameters of the system as well as for the five "post-Keplerian" orbital parameters that can be used to test gravitation theory. The results are in good agreement with the predictions of general relativity. With the assumption that general relativity is the correct theory of gravity in the classical regime, our measurements allow us to determine the masses of the pulsar and its companion neutron star with high accuracy: 1.3332 ± 0.0010 M☉ and 1.3452 ± 0.0010 M☉, respectively. The small but significant mass difference is difficult to understand in most evolutionary models, as the pulsar is thought to have been born first from a more massive progenitor star and then undergone a period of mass accretion before the formation of the second neutron star. PSR B1534+12 has also become a valuable probe of the local interstellar medium. We have now measured the pulsar distance to be 1.02 ± 0.05 kpc, giving a mean electron density along this line of sight of 0.011 cm-3. We continue to measure a gradient in the dispersion measure, though the rate of change is now slower than in the first years after the pulsar's discovery.
Mechanical Domain Parametric Amplification

Though utilized for more than 50 years in a variety of power and communication systems, parametric amplification, the process of amplifying a harmonic signal with a parametric pump, has received very little attention in the mechanical engineering community. In fact, only within the past 15-20 years has the technique been implemented in micromechanical systems as a means of amplifying the output of resonant microtransducers. While the vast potential of parametric amplification has been demonstrated, to date, in a number of micro- and nanomechanical systems (as well as a number electrical systems), few, if any, macroscale mechanical amplifiers have been reported. Given that these amplifiers are easily realizable using larger-scale mechanical systems, the present work seeks to address this void by examining a simple' representative example: a cantilevered beam with longitudinal and transverse base excitations. The work begins with the systematic formulation of a representative system model, which is used to derive a number of pertinent metrics. A series of experimental results, which validate the work's analytical findings, are subsequently examined, and the work concludes with a brief look at some plausible applications of parametric amplification in macroscale mechanical systems.
On Decoherence in Quantum Clock Synchronization

We study two quantum versions of the Eddington clock-synchronization protocol in the presence of decoherence. The first protocol uses maximally entangled states to achieve the Heisenberg limit for clock synchronization. The second protocol achieves the limit without using entanglement. We show the equivalence of the two protocols under any single-qubit decoherence model that does not itself provide synchronization information.
Test for generalized variance in signal processing

Abstract We derive a likelihood ratio test for generalized variance in signal processing following the method of Sengupta (1987). We discuss the solution in both white noise and colored noise cases. The asymptotic distribution of the test statistics in both the cases follows chi-square with one degree of freedom from general theory of likelihood ratio test.
The effect of lattice pruning on MMIE training

In discriminative training, such as Maximum Mutual Information Estimation (MMIE) training, a word lattice is usually used as a compact representation of many different sentence hypotheses and hence provides an efficient representation of the confusion data. However, in a large vocabulary continuous speech recognition (LVCSR) system trained from hundreds or thousands hours training data, the extended Baum-Welch (EBW) computation on the word lattice is still very expensive. In this paper, we investigated the effect of lattice pruning on MMIE training, where we tested the MMIE performance trained with different lattice complexity. A beam pruning and a posterior probability pruning method were applied to generate different sizes of word lattices. The experimental results show that using the posterior probability lattice pruning algorithm, we can save about 40% of the total computation and get the same or more improvement compared to the baseline MMIE result.
Model for nodal quasiparticle scattering in a disordered vortex lattice

Recent scanning-tunneling experiments on ${\text{Ca}}_{2\ensuremath{-}x}{\text{Na}}_{x}{\text{CuO}}_{2}{\text{Cl}}_{2}$ by Hanaguri et al. [Science 323, 923 (2009)] observe field-dependent quasiparticle interference effects which are sensitive to the sign of the $d$-wave order parameter. Their analysis of spatial fluctuations in the local density of states shows that there is a selective enhancement of quasiparticle scattering events that preserve the gap sign and a selective depression of the quasiparticle scattering events that reverse the gap sign. We introduce a model which accounts for this phenomenon as a consequence of vortex pinning to impurities. Each pinned vortex embeds several impurities in its core. The observations of recent experiments can be accounted for by assuming that the scattering potentials of the impurities inside the vortex cores acquire an additional resonant or Andreev scattering component, both of which induce gap sign preserving scattering events.
Quasi-periodic flares from star-accretion-disc collisions

We present simulated results of quasi-periodic flares generated by the inelastic collisions of a star bound to a supermassive black hole and its attendant accretion disc. We show that the behaviour of the quasi-periodicity is affected by the mass and spin of the black hole and the orbital elements of the stellar orbit. We also evaluate the possibility of extracting useful information on these parameters and verifying the character of the Kerr metric from such quasi-periodic signals. Comparisons are made with the observed optical outbursts of OJ 287, infrared flares from the Galactic Centre and X-ray variability in RE J1034+396.
Asymptotic behavior of the expansion method for open finite queueing networks

In previous papers, we have reported on the use of the expansion method for estimating sojourn times in finite network topologies. In this paper, we focus on comparing the expansion method with P. C. Bell's consistency conditions where subject to unbalanced service rates at tandem queues, other decomposition approaches yield impossible throughput results. We compare numerical results of the expansion method with the other approaches in light of these conditions.
Adaptive control of photolithography

Adaptive control techniques, with their capability for providing satisfactory control even when the process changes with time, are promising candidates for dealing with common problems encountered in photolithography processing such as batch-to-batch variations in resist properties and inconsistencies in resist curing. In this article, an adaptive control strategy for the photolithography process is proposed and evaluated. The design utilizes a reduced-order lithography model, an on-line parameter estimator, and a nonlinear model-inversion controller. The width of the printed resist lines, a crucial output of photolithography, is controlled by automatically adjusting the exposure energy. In the calculation of the appropriate exposure adjustment, the controller uses both measured critical-dimensions as well as estimated values produced by the process model. The control system is capable of tracking changes in the photolithography process by automatic updating of key model parameters as the process evolves in time. Simulation studies of the closed-loop adaptive control strategy, using the PROLITH simulation package to represent the lithography process, demonstrate the feasibility of this approach.
Incoherent control and entanglement for two-dimensional coupled systems

We investigate accessibility and controllability of a quantum system S coupled to a quantum probe P, both described by two-dimensional Hilbert spaces, under the hypothesis that the external control affects only P. In this context accessibility and controllability properties describe to what extent it is possible to drive the state of the system S by acting on P and using the interaction between the two systems. We give necessary and sufficient conditions for these properties and we discuss the relation with the entangling capability of the interaction between S and P. In particular, we show that controllability can be expressed in terms of the SWAP and {radical}(SWAP) operators acting on the composite system.
Strain-Based Analysis for Geometrically Nonlinear Beams: A Modal Approach

A strain-based geometrically nonlinear beam formulation for structural dynamic and aeroelastic analysis of slender beams and wings has been successfully applied to study the coupled nonlinear aeroelasticity and flight dynamics of different very flexible aircraft. As an extension to the solution technique based on the nonlinear finite element developed by the authors, a modal-based approach is discussed in this paper to solve the strain-based nonlinear beam equations. The modal approach is applied to study geometrically nonlinear static and transient problems of constrained and free slender beams, subject to external structural or aero-dynamic excitations. The efficiency of the modal solution is also compared to that of the finite-element approach. Nomenclature a0 = local aerodynamic frame, with a0y axis aligned with zero lift line of airfoil a1 = local aerodynamic frame, with a1y axis aligned with airfoil motion velocity B = body reference frame B F , B M = influence matrices for the distributed forces and moments b = positions and orientations of the B frame, as time integral of β bc = semichord of airfoil, m
An Exploratory Comparison of the Behavioral Dynamics of Top Management Teams in Family and Nonfamily New Ventures: Cohesion, Conflict, Potency, and Consensus

While some researchers propose that the combination of family and business creates a need for trade–offs in family and business demands, we argue that the social system of the family creates a syne...
Asymmetric currency exposure of US bank stock returns

Abstract Most of previous studies have not been successful in finding significant currency exposure. One possible explanation for this failure is that these studies ignore the asymmetric relationship between the value of a firm and exchange rate. Consequently, in this paper, I explore the possibility of asymmetric currency exposure using US bank stocks. The empirical results show that more than 80% of the sample are significantly exposed to exchange rate changes in a asymmetric way based on the tests of multi-factor model with multivariate GARCH parameterization. This empirical finding is robust to whether contemporaneous or lagged exchange rates changes are used to estimate the model. The strong evidence of asymmetric currency exposure suggests that both asymmetry and conditional heteroskedasticity play important roles in estimating currency exposure.
Bucket Hashing and Its Application to Fast Message Authentication

We introduce a new technique for constructing a family of universal hash functions. At its center is a simple metaphor: to hash a string x , cast each of its words into a small number of buckets; xor the contents of each bucket; then collect up all the buckets' contents. Used in the context of Wegman--Carter authentication, this style of hash function provides a fast approach for software message authentication.
Toward fully synthetic N-linked glycoproteins.

procedure. Elemental analysis (%) calcd for C13H8NO4Cu: C 51.06, H 2.62, N 4.58; found C 50.62, H 2.45, N 4.60. Gas adsorption measurements: Sorption isotherms were measured at 298 K on an FMS-BG (BEL inc.) automatic gravimetric adsorption measurement system with Rubotherm magnet coupling balance incorporated in a SUS steel pressure chamber. A known weight (200±300 mg) of the as-synthesized sample was placed in the aluminum sample cell in the chamber, and the sample was dried under high vacuum at 373 K for 5 h to remove the host water molecules. The adsorbate was dosed into the chamber, and the change in weight was monitored. After correction for buoyancy, the absorbed amount was determined.
The Self-Similarity of Shear-dominated Viscous Stirring

We examine the growth of eccentricities of a population of particles with nearly circular orbits around a central massive body. Successive encounters between pairs of particles increase the eccentricities in the disk on average. We describe the system in terms of a Boltzmann equation. As long as the epicyclic motions of the particles are small compared to the shearing motion between circular Keplerian orbits, there is no preferred scale for the eccentricities, and the evolution is self-similar. This simplification reduces the full time-dependent Boltzmann equation to two separate equations: one that describes the shape of the distribution and another that describes the evolution of the characteristic eccentricity on which the distribution is centered. We find that the shape of the eccentricity distribution function is a general feature of such systems, and is of the form (1 + x^2)^(-3/2). In particular, bodies evolving under only their own excitations have the same eccentricity distribution profile as bodies whose excitations are balanced by dynamical friction. We find exact expression for the typical eccentricity for these two cases, and allow for time-dependent damping and excitation rates. Full numerical N-body simulations of a disk with 200 planetesimals verify our analytical self-similar distribution.
Rigid Schubert varieties in compact Hermitian symmetric spaces

Given a singular Schubert variety X w in a compact Hermitian symmetric space X, it is a long-standing question to determine when X w is homologous to a smooth variety Y. We identify those Schubert varieties for which there exist first-order obstructions to the existence of Y. This extends (independent) work of M. Walters, R. Bryant and J. Hong. Key tools include (i) a new characterization of Schubert varieties that generalizes the well-known description of the smooth Schubert varieties by connected sub-diagrams of a Dynkin diagram and (ii) an algebraic Laplacian (a la Kostant), which is used to analyze the Lie algebra cohomology group associated with the problem.
An extremely potent inhibitor for β-galactosidase

Abstract A new galactose-type iminosugar in which a nitrogen atom is in the anomeric position was synthesized and was found to be an extremely potent inhibitor for β-galactosidase with Ki = 4 nM.
Modeling of liquid jets injected transversely into a supersonic crossflow

Analytical/numerical modeling of the behavior of a single nonreacting liquid jet in compressible (high subsonic and supersonic) crossflows is described here. Inviscid, compressible flow about the elliptical cross-section of the jet is solved numerically, using a procedure modeled after that of Godunov. External boundary layer analysis along the surface of the elliptical cross-section allows determination of an effective drag associated with the jet, which balances centripetal forces resulting from jet deflection. Mass and momentum balances performed along the jet, with and without the inclusion of mass loss due to droplet shedding, are then incorporated so that liquid jet trajectories and bow shock penetration may be calculated. Comparisons of the predictions are made with experimental results.
An active contour based method for analyzing cardiac quiescence from echocardiography

A semi-automated method for analyzing cardiac quiescence of anatomical cardiac features from two-dimensional echocardiographic cine data is presented. The method utilizes both active contour and optical flow techniques for feature identification and tracking. A curvature-based potential surface was used in the active contour calculations to attract the contour to regions of inflection on the image surface rather than the standard gradient-based surface that attracts the contour to strong edges. After identifying the feature in each frame, the frame-to-frame correlation matrix of the feature was calculated with correlation values corresponding to how well the feature matched between frames. Therefore prolonged regions of high correlation correspond to periods of cardiac quiescence. The location and duration of these periods were automatically identified from the correlation matrix by finding the largest region around each time index with a mean correlation above a specified threshold. In parallel, the position of the feature was calculated for each frame by finding the centroid of the pixel locations inside the contour. From this trajectory, the magnitude of the two-dimensional velocity was calculated. These methods were used to analyze the quiescence of the interventricular septum from an apical four-chamber echocardiogram performed on a human subject. Correlation-derived quiescent phases were observed to coincide with periods of the cardiac cycle with minimal velocity magnitude.
Reframing the brain drain

Theorists concerned about the distributive effects of skilled emigration (‘brain drain’) often argue that its harmful effects can be justly mitigated by restricting emigration from sending countries or by limiting immigration opportunities to receiving countries. I raise moral and practical concerns against restricting the movement of skilled migrants and contend that conceptualizing the moral issue in these terms leads theorists to neglect the moral salience of institutions that determine the distributive effects of migration. Using an analogy to skilled migration in a domestic context, I argue for locating brain drain in a more holistic, institutional context that includes the reform of global institutions and of policies affecting migration.
Cyclization/hydrosilylation of functionalized diynes catalyzed by a cationic platinum phenanthroline complex.

A 1:1 mixture of the platinum phenanthroline complex (phen)PtMe2 and B(C6F5)3 catalyzed the cyclization/hydrosilylation of functionalized 1,6- and 1,7-diynes to form silylated 1,2-dialkylidenecycloalkanes in good yield and with high Z-selectivity.
Static and Impulsive Models of Solar Active Regions

The physical modeling of active regions (ARs) and of the global corona is receiving increasing interest lately. Recent attempts to model ARs using static equilibrium models were quite successful in reproducing AR images of hot soft X-ray (SXR) loops. They however failed to predict the bright extreme-ultraviolet (EUV) warm loops permeating ARs: the synthetic images were dominated by intense footpoint emission. We demonstrate that this failure is due to the very weak dependence of loop temperature on loop length which cannot simultaneously account for both hot and warm loops in the same AR. We then consider time-dependent AR models based on nanoflare heating. We demonstrate that such models can simultaneously reproduce EUV and SXR loops in ARs. Moreover, they predict radial intensity variations consistent with the localized core and extended emissions in SXR and EUV AR observations, respectively. We finally show how the AR morphology can be used as a gauge of the properties (duration, energy, spatial dependence, and repetition time) of the impulsive heating.
Design of feedforward filters for improving tracking performances of existing feedback control systems

A design procedure for feedforward filters is proposed to improve the tracking performance of existing closed-loop systems. A parametric model is not required because it directly utilizes the frequency response of the closed-loop system, which can be measured accurately. This frequency-shaping approach enables the tradeoff between the quality of model-matching and the size of control efforts by adjusting weighting filters. Time domain specifications can be specified indirectly by approximating them in the frequency domain. The procedure is intuitively simple for SISO systems. Generalization for MIMO systems is possible by formulating convex optimization problems. A feedforward filter is designed and implemented on a nanopositioning system for semiconductor manufacturing, to improve its transient response.