cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of kinked linear defects on planar flux line arrays

In the hard core limit, interacting vortices in planar type II superconductors can be modeled as non-interacting one dimensional fermions propagating in imaginary time. We use this analogy to derive analytical expressions for the probability density and imaginary current of vortex lines interacting with an isolated bent line defect and to understand the pinning properties of such systems. When there is an abrupt change of the direction of the pinning defect, we find a sinusoidal modulation of the vortex density in directions both parallel and perpendicular to the defect.
Extendible range-based numbering scheme for XML document

Range-based labeling scheme allows determining the ancestor relation between two nodes in constant time. One disadvantage is that relabeling is unavoidable when arbitrary insertions are allowed. In this paper, one practical algorithm is presented to extend range-based scheme to accommodate arbitrary insertions without relabeling by combining with prefix-based labeling scheme. Range allocation methods to improve the performance of the labeling method are also considered.
Low- and intermediate-mass close binary evolution and the initial-final mass relation

Using Eggleton's stellar evolution code, we carry out 150 runs of Population I binary evolution calculations with the initial primary mass between 1 and 8 M-circle dot, the initial mass ratio q = M-1/M-2 between 1.1 and 4, and the onset of Roche lobe overflow (RLOF) at an early, middle or late Hertzsprung-gap stage. We assume that PLOP is conservative in the calculations, and find that the remnant mass of the primary may change by more than 40 per cent over the range of initial mass ratio or orbital period, for a given primary mass. This is contrary to the often-held belief that the remnant mass depends only on the progenitor mass if mass transfer begins in the Hertzsprung gap. We fit a formula, with an error less than 3.6 per cent, for the remnant (white dwarf) mass as a function of the initial mass M-li of the primary, the initial mass ratio q(i) and the radius of the primary at the onset of RLOF We also find that a carbon-oxygen white dwarf with mass as low as 0.33 M-circle dot may be formed if the initial mass of the primary is around 2.5 M-circle dot.
On the origin of chaos in autonomous Boolean networks.

We undertake a systematic study of the dynamics of Boolean networks to determine the origin of chaos observed in recent experiments. Networks with nodes consisting of ideal logic gates are known to display either steady states, periodic behaviour or an ultraviolet catastrophe where the number of logic-transition events circulating in the network per unit time grows as a power law. In an experiment, the non-ideal behaviour of the logic gates prevents the ultraviolet catastrophe and may lead to deterministic chaos. We identify certain non-ideal features of real logic gates that enable chaos in experimental networks. We find that short-pulse rejection and asymmetry between the logic states tend to engender periodic behaviour, at least for the simplest networks. On the other hand, we find that a memory effect termed ‘degradation’ can generate chaos. Our results strongly suggest that deterministic chaos can be expected in a large class of experimental Boolean-like networks. Such devices may find application in a variety of technologies requiring fast complex waveforms or flat power spectra, and can be used as a test-bed for fundamental studies of real-world Boolean-like networks.
[Cd2(H2O)4][Re6S8(CN)6]·14H2O: A Cyano-Bridged Cluster−Cluster Framework Solid with Accessible Cubelike Cavities

Reaction between Cd2+ and Na4[Re6S8(CN)6] in aqueous solution affords the porous solid [Cd2(H2O)4][Re6S8(CN)6]·14H2O. As determined by X-ray crystallographic analysis, its structure consists of an expanded Prussian blue type framework with [Re6S8]2+ and [Cd2(μ-OH2)2]4+ cluster cores occupying alternate metal ion sites. Experiments probing the thermal stability and inclusion properties of this new solid material are described.
Rapid Photoassisted Access to N,O,S‐Polyheterocycles with Benzoazocine and Hydroquinoline Cores: Intramolecular Cycloadditions of Photogenerated Azaxylylenes

o-Azaxylylenes have been known for half a century, but remained in relative synthetic obscurity until a decade ago, when Corey and Steinhagen reported their first preparation under simple mild conditions by base-induced elimination of hydrogen chloride from derivatives of o-chloromethylaniline. It was noted that “Surprisingly, simplest method possible for o-azaxylylene production ... has never been reported.” Synthetically useful reactions of o-xylylenes (i.e. allcarbon o-quinodimethanes) are plentiful, and their generation from aromatic o-alkyl ketones by an intramolecular photoinduced hydrogen abstraction is well documented. Given this fact, it was surprising to us that the equally simple photogeneration of o-azaxylylenes from o-aminoketones by an excited-state intramolecular proton transfer (ESIPT) has never been utilized in synthetic chemistry. It is conceivable that such implementation was attempted but failed due to the fast back proton transfer successfully competing with bimolecular cycloadditions. Intramolecular proton transfers from one heteroatom to another (and back) are fast; a typical example is the much studied photophysics of salicylaldehyde or o-hydroxyacetophenone, although the elusive tautomeric form is not impossible to characterize. We, however, found that the intramolecular cycloaddition reactions of o-azaxylylenes photogenerated by excited-state proton transfer can successfully compete with the back proton transfer. Herein, we report the first example of [4+ 2] and [4+ 4] cycloaddition reactions of photogenerated azaxylylenes with unsaturated pendant groups; this reaction offers expeditious access to a diverse array of N,S,O-polyheterocycles with mostly unprecedented topologies (Scheme 1). As the azaxylylenes are expected to act as acceptors in the inverse-electron-demand cycloaddition reactions, we synthesized photoactive azaxylylene precursors 1 and 4 by coupling o-aminoketones with furanor thiophenepropionic acid chlorides. These o-acylamido precursors have broad UV Scheme 1. Photogeneration of azaxylylenes and their intramolecular photocyclizations.
The EU Factor in Fat Times and in Lean: Did the EU Amplify the Boom and Soften the Bust?†

This article describes the EU’s impact on economic performance in the new Member States since the advent of membership. It first deals with the EU’s role in promoting the economic boom that marked the region up to 2007, emphasizing the role of the single market and of the EU in anchoring and encouraging economic policy liberalization. The second section investigates the EU role in buffering the bust that occurred after 2007, looking at structural fund spending and financial sector instruments to enhance liquidity. I argue the EU had a (mostly unintentional) pro-cyclical effect that fuelled the boom and contributed to setting up the region for a very hard fall during the bust. I also show the EU efforts to buffer the hard times were far quicker in the area of structural fund spending compared to very slow and limited innovation in liquidity provision, especially for non-eurozone states.
Policy-Enhanced private set intersection: sharing information while enforcing privacy policies

Companies, organizations, and individuals often wish to share information to realize valuable social and economic goals. Unfortunately, privacy concerns often stand in the way of such information sharing and exchange. This paper proposes a novel cryptographic paradigm called Policy-Enhanced Private Set Intersection (PPSI ), allowing two parties to share information while enforcing the desired privacy policies. Our constructions require minimal additional overhead over traditional Private Set Intersection (PSI) protocols, and yet we can handle rich policy semantics previously not possible with traditional PSI and Authorized Private Set Intersection (APSI) protocols. Our scheme involves running a standard PSI protocol over carefully crafted encodings of elements formed as part of a challenge-response mechanism. The structure of these encodings resemble techniques used for aggregating BLS signatures in bilinear groups. We prove that our scheme is secure in the malicious model, under the CBDH assumption, the random oracle model, and the assumption that the underlying PSI protocol is secure against malicious adversaries.
Information Technology and the Demand for Educated Workers: Disentangling the Impacts of Adoption versus Use

This paper examines the effect of information technology (IT) on the relative demand for educated workers in U.S. industries from 1960 to 1996. After decomposing this effect into IT use and adoption, I find that the use of IT is complementary with educated workers, and that educated workers have a comparative advantage in the adoption of IT. In total, IT use and adoption effects account for almost 40% of the acceleration in demand for educated workers since 1970. Moreover, the adoption of IT explains about one-third of the total IT effect on the acceleration in skill upgrading in the 1970s.
Extensions of Quandles and Cocycle Knot Invariants

Quandle cocycles are constructed from extensions of quandles. The theory is parallel to that of group cohomology and group extensions. An interpretation of quandle cocycle invariants as obstructions to extending knot colorings is given, and is extended to links component-wise.
Reduced convergence and the local smoothness parameter: bridging two different descriptions of weak lensing amplification

Weak gravitational lensing due to the inhomogeneous matter distribution in the universe is an important systematic uncertainty in the use of standard candles in cosmology. There are two different descriptions of weak-lensing amplification: one uses a local smoothness parameter , and the other uses reduced convergence η = 1 + κ/|κmin| (where κ is convergence). The description involves Dyer-Roeder distance DA(|z) ( = 1 corresponds to a smooth universe); it is simple and convenient and has been used by the community to illustrate the effect of weak lensing on point sources such as Type Ia supernovae. Wang has previously shown that the description can be made realistic by allowing to be a local variable, the local smoothness parameter. The η description has been used by Wang et al. to derive a universal probability distribution for weak-lensing amplification. In this paper, we bridge the two different descriptions of weak-lensing amplification by relating the reduced convergence η and the local smoothness parameter . We give the variance of in terms of the matter power spectrum, thus providing a quantitative guidance to the use of Dyer-Roeder distances in illustrating the effect of weak lensing. The by-products of this work include a corrected definition of the reduced convergence and simple and accurate analytical expressions for DA(|z). Our results should be very useful in studying the weak lensing of standard candles.
Weighted sensitivity minimization in systems with a single input delay: a state space solution

An operator Riccati equation solution, based on a Hilbert state space model is reduced to n/spl times/n matrix algebraic/differential Riccati equations and R/sup n/ compensator dynamics, via a two way analysis of an underlying differential game: both in the original delay system, in R/sup n/, and in a distributed parameter evolution model.
Primordial Gravitational Wave Calculations: Nonlinear vs Linear Codes

Physics Department, University of Houston Clear Lake, Houston, Texas 77058E-mail: garrison@uhcl.eduAbstract. This work is a follow-up to the paper, "Numerical Relativity as a Toolfor Studying the Early Universe". In this article, we present the rst results of directnumerical simulations of primordial plasma turbulence as it applies to the generation ofgravitational waves. We calculate the normalized energy density, strain and degree ofpolarization of gravitational waves produced by a simulated turbulent plasma similar towhat was believed to have existed at the electroweak scale, 246 GeV. This calculationis completed using two numerical codes, one which utilizes full General Relativitycalculations based on modi ed BSSN equations while the other utilizes a linearizedapproximation of General Relativity. Our results show that there is a signi cantdi erence between the spectrum of gravitational waves calculated using a nonlinearcode as opposed to that calculated with a linear approximation. This implies thatsimulations that do not take into account nonlinear e ects may not give accurateresults.
Space Interferometry Mission spacecraft pointing error budgets

Preliminary error budgets for the pointing knowledge, control, and stability of the Space Interferometry Mission (SIM) spacecraft are constructed using the specifications of commercial off-the-shelf attitude determination sensors, attitude control actuators, and other spacecraft capabilities that have been demonstrated in past missions. Results obtained indicate that we can meet all the presently known spacecraft pointing requirements. A large number of derived requirements are generated from this study. Examples are specifications on attitude determination sensors, attitude control actuators, minimum settling time after a rest-to-rest spacecraft slew. Preliminary error budgets constructed in this study must be updated to reflect the changing spacecraft design and requirements.
Transparent optimistic rollback recovery

Abstract : What are appropriate paradigms for supporting fault-tolerant applications and how can they be implemented efficiently? To what extent can fault tolerance be retrofitted into existing applications automatically? What lessons can be learned from existing implementations of fault-tolerant and distributed systems?
Nonlinear Dual-Mode Control of Variable-Speed Wind Turbines With Doubly Fed Induction Generators

This paper presents a feedback/feedforward nonlinear controller for variable-speed wind turbines with doubly fed induction generators. By appropriately adjusting the rotor voltages and the blade pitch angle, the controller simultaneously enables: 1) control of the active power in both the maximum power tracking and power regulation modes; 2) seamless switching between the two modes; and 3) control of the reactive power so that a desirable power factor is maintained. Unlike many existing designs, the controller is developed based on original, nonlinear, electromechanically-coupled models of wind turbines, without attempting approximate linearization. Its development consists of three steps: 1) employ feedback linearization to exactly cancel some of the nonlinearities and perform arbitrary pole placement; 2) design a speed controller that makes the rotor angular velocity track a desired reference whenever possible; and 3) introduce a Lyapunov-like function and present a gradient-based approach for minimizing this function. The effectiveness of the controller is demonstrated through simulation of a wind turbine operating under several scenarios.
Millimeter-wave propagation measurements at the Ballistic Research Laboratory

Results of measurements made with radars from 35 to 217 GHz of near-Earth propagation in rain, fog, snow, and humidity are presented and discussed. >
An economic analysis of generic egg advertising in California, 1985–1995

A supply and demand econometric model of the California egg industry was estimated to evaluate the impact of generic egg advertising on producer prices and returns from 1985 to 1995. Econometric estimation indicated advertising had a positive impact on producer prices and net profits. The model was simulated with existing advertising expenditure levels, and with expenditures 1% higher than actual levels. A 1% increase in advertising expenditures resulted in an average 0.13% increase in producer prices and a marginal rate of return to advertising of 6.9. In other words, each additional dollar spent on advertising generated $6.90 in producers' profits. © 1997 John Wiley & Sons, Inc.
Improving operating room schedules

Operating rooms (ORs) in US hospitals are costly to staff, generate about 70 % of a hospital’s revenues, and operate at a staffed-capacity utilization of 60-70 %. Many hospitals allocate blocks of OR time to individual or groups of surgeons as guaranteed allocation, who book surgeries one at a time in their blocks. The booking procedure frequently results in unused time between surgeries. Realizing that this presents an opportunity to improve OR utilization, hospitals manually reschedule surgery start times one or two days before each day of surgical operations. The purpose of rescheduling is to decrease OR staffing costs, which are determined by the number of concurrently staffed ORs. We formulate the rescheduling problem as a variant of the bin-packing problem with interrelated items, which are the surgeries performed by the same surgeon. We develop a lower bound (LB) construction algorithm and prove that the LB is at least (2/3) of the optimal staffing cost. A key feature of our approach is that we allow hospitals to have two shift lengths. Our analytical results form the basis of a branch-and-bound algorithm, which we test on data obtained from three hospitals. Experiments show that rescheduling saves significant staffing costs.
A Study of Linux File System Evolution

We conduct a comprehensive study of file-system code evolution. By analyzing eight years of Linux file-system changes across 5079 patches, we derive numerous new (and sometimes surprising) insights into the file-system development process; our results should be useful for both the development of file systems themselves as well as the improvement of bug-finding tools.
Development of a Molten-Salt Thermocline Thermal Storage System for Parabolic Trough Plants

Thermal storage improves the dispatchability and marketability of parabolic trough power plants allowing them to produce electricity on demand independent of solar collection. One such thermal storage system, a thermocline, uses a single tank containing a fluid with a thermal gradient running vertically through the tank, where hotter fluid (lower density) is at the top of the tank and colder fluid is at the base of the tank. The thermal gradient separates the two temperature potentials. A low-cost filler material provides the bulk of the thermal capacitance of the thermal storage, prevents convective mixing, and reduces the amount of fluid required. In this paper, development of a thermocline system that uses molten-nitrate salt as the heat transfer fluid is described and compared to a two-tank molten salt system. Results of isothermal and thermal cycling tests on candidate materials and salt safety tests are presented as well as results from a small pilot-scale (2.3 MWh) thermocline.
SATELLITE ORBIT DETERMINATION USING A SINGLE-CHANNEL GLOBAL POSITIONING SYSTEM RECEIVER

A proposed satellite orbit determination system has been analyzed, one that uses measurements from a single-channel Global Positioning System (GPS) receiver. The purpose of this study is to predict the likely efficacy of a low-power, low-mass autonomous orbit determination system. The system processes the pseudo range outputs of the receiver using an extended Kalman filter. It also has the option of using the carrier phase measurements. The receiver cycles through different GPS satellites, tracking a new one every 2 minutes, in order to achieve observability and good accuracy. The Kalman filter uses a dynamic model of the spacecraft orbit and of the receiver clock's drift. Simulation results predict that the system can achieve accuracies ranging from 8mto50m3crin low Earth orbit. The accuracy depends on what type of oscillator is used for the receiver clock and on the level of uncertainty in the orbital dynamics model. The system can also operate in geosynchronou s orbits, but its accuracy degrades to 400 m 3 a, and it must use an ovenized crystal oscillator as its receiver clock.
Cross-Genre Feature Comparisons for Spoken Sentence Segmentation

Automatic sentence segmentation of spoken language is an important precursor to downstream natural language processing. Previous studies combine lexical and prosodic features, but can impose significant computational challenges because of the large size of feature sets. Little is understood about which features most benefit performance, particularly for speech data from different speaking styles. We compare sentence segmentation for speech from broadcast news versus natural multi-party meetings, using identical lexical and prosodic feature sets across genres. Results based on boosting and forward selection for this task show that (1) features sets can be reduced with little or no loss in performance, and (2) the contribution of different feature types differs significantly by genre. We conclude that more efficient approaches to sentence segmentation and similar tasks can be achieved, especially if genre differences are taken into account.
An investigation of patterns in hemodynamic data indicative of impending hypotension in intensive care

In the intensive care unit (ICU), clinical staff must stay vigilant to promptly detect and treat hypotensive episodes (HEs). Given the stressful context of busy ICUs, an automated hypotensive risk stratifier can help ICU clinicians focus care and resources by prospectively identifying patients at increased risk of impending HEs. The objective of this study was to investigate the possible existence of discriminatory patterns in hemodynamic data that can be indicative of future hypotensive risk. Given the complexity and heterogeneity of ICU data, a machine learning approach was used in this study. Time series of minute-by-minute measures of mean arterial blood pressure, heart rate, pulse pressure, and relative cardiac output from 1,311 records from the MIMIC II Database were used. An HE was defined as a 30-minute period during which the mean arterial pressure was below 60 mmHg for at least 90% of the time. Features extracted from the hemodynamic data during an observation period of either 30 or 60 minutes were analyzed to predict the occurrence of HEs 1 or 2 hours into the future. Artificial neural networks (ANNs) were trained for binary classification (normotensive vs. hypotensive) and regression (estimation of future mean blood pressure). The ANNs were successfully trained to discriminate patterns in the multidimensional hemodynamic data that were predictive of future HEs. The best overall binary classification performance resulted in a mean area under ROC curve of 0.918, a sensitivity of 0.826, and a specificity of 0.859. Predicting further into the future resulted in poorer performance, whereas observation duration minimally affected performance. The low prevalence of HEs led to poor positive predictive values. In regression, the best mean absolute error was 9.67%. The promising pattern recognition performance demonstrates the existence of discriminatory patterns in hemodynamic data that can indicate impending hypotension. The poor PPVs discourage a direct HE predictor, but a hypotensive risk stratifier based on the pattern recognition algorithms of this study would be of significant clinical value in busy ICU environments.
2,4-Dichlorophenoxy acetic acid and indoleacetic acid partially counteract inhibition of organogenesis by difluoromethylornithine

Difluoromethylornithine (DFMO) is a well known inhibitor of putrescine biosynthesis that has been reported to interact in varying ways with auxins such as indoleacetic acid (IAA) and 2,4-dichlorophenoxy acetic acid (2,4-D). In the present report DFMO is shown to inhibit root formation in isolated hypocotyl segments of Euphorbia esula L. (leafy spurge) grown in the dark on solidified nutrient media in Petri dishes. Shoot formation was only slightly inhibited by DFMO and only on media with salts and vitamins diluted 10-fold. 2,4-D inhibited both root and shoot formation in full strength or diluted media. Simultaneous application of both compounds resulted in partial reversal of root inhibition, but only at 450 nM 2,4-D, the highest concentration used. In both media IAA also partially reversed DFMO effects on root formation. The effects of DFMO, 2,4-D or IAA on root (or shoot) formation do not appear to be closely related to endogenous content of the polyamines determined by high performance liquid chromatography.
Public Health Insurance Expansions and Hospital Technology Adoption

Abstract This paper explores the effects of public health insurance expansions on hospitals' decisions to adopt medical technology. Specifically, we test whether the expansion of Medicaid eligibility for pregnant women during the 1980s and 1990s affects hospitals' decisions to adopt neonatal intensive care units (NICUs). While Medicaid expansion provided new insurance to a substantial number of pregnant women, prior literature also finds that some newly insured women would otherwise have been covered by more generously reimbursed private sources. Such crowd-out, combined with Medicaid's low reimbursement rats, leads to a theoretically ambiguous net effect of Medicaid expansion on a hospital's incentive to invest in technology. Using American Hospital Association data, we find that on average, Medicaid expansion has no statistically significant effect on NICU adoption. However, we also find that in geographic areas where more of the newly Medicaid-insured may have come from the privately insured population, Medicaid expansion slows NICU adoption. This holds true particularly when Medicaid payment rates are very low relative to private payment rates. Our findings are consistent with prior evidence on reduced NICU adoption from increased managed-care penetration. We conclude by discussing the policy implications of our work for insurance expansions associated with the Affordable Care Act.
Altered fine structure of B lymphocytes correlated with defective terminal differentiation.

Peripheral blood lymphocytes from three patients with defective differentiation of B cells were studied by routine electron microscopic techniques. One patient had severe combined immunodeficiency with rudimentary development of the B cell line. Two had immune deficits secondary to the B cell malignancy, chronic lymphocytic leukemia. Accumulations of tuboreticular structures were found in the cytoplasm of lymphocytes from the severe combined immune deficiency patient, sometimes in close association with annulate lamellae. The tuboreticular structures resemble those described in lymphocytes and endothelial cells of patients with systemic lupus erythematosus. In one patient with chronic lymphocytic leukemia, cylindrical arrangements of ribosomal material occupied the cytoplasm of many lymphocytes. These cylinders were observed in samples of blood drawn at different times and after tissue culture of lymphocytes with and without pokeweed mitogen. The other patient with chronic lymphocytic leukemia had circulating lymphocytes with material identified as IgM in the perinuclear spaces and dilated cisternae of the rough endoplasmic reticulum. This material sometimes had a crystalline structure. These observations indicate that in some cases functional immunological deficits in B cells, manifested by failure to differentiate to mature secretory cells, may be correlated with morphological aberrations of protein-manufacturing organelles within the cell.
Polyazide chemistry: preparation and characterization of As(N3)5, Sb(N3)5, and [P(C6H5)4][Sb(N3)6)].

Abstract : The binary arsenic- and antimony azide species AS(N3)3, As(N3)4+, As(N3)4-, As(N3)6-, Sb(N3)3, Sb(N3)4+, Sb(N3)4- and Sb(N3)6- have previously been reported, and the crystal structures of As(N3)3, Sb(N3)3 and As(N3)6- were determined. In addition, the Lewis based stabilized species M(N3)5-LB (M=As,Sb; LB=pyridine, quinoline NH3, N2H4, NH2CN) were published. However, previous attempts to obtain the neat pentaazides of arsenic and antimony were not successful. Even at low temperatures, attempted syntheses resulted in explosions that were described as "so intense that only pulverized glass remained." Furthermore, As(N3)5 was predicted to be a "highly unstable compound," based on its analogy to AsCl5. In this paper, we wish to communicate the synthesis and characterization of neat As(N3)5 and Sb(N3)5, and their conversion to the As(N3)6 and Sb(N3)6 anions, respectively. We also report the crystal structure of P(C6H5)4Sb(N3)6.
The calculus of piratical consent: the myth of the myth of social contract

Is a genuine social contract mythical? I argue that pirates created genuine social contracts that established a system of constitutional democracy based on the same decision-making calculus and with the same effects that Buchanan and Tullock’s contractarian theory of government describes in The Calculus of Consent. Pirates’ constitutional democracy is the “holy grail” of social contract theory. It demonstrates that the contractarian basis of constitutional democracy is more than a mere analytic device or hypothetical explanation of how such a government could emerge. In pirates’ case, Buchanan and Tullock’s social contract theory describes how constitutional democracy actually did emerge.
Complementarity of LHC and EDMs for Exploring Higgs CP Violation

We analyze the constraints on a CP-violating, flavor conserving, two Higgs doublet model from the measurements of Higgs properties and from the search for heavy Higgs bosons at LHC, and show that the stronger limits typically come from the heavy Higgs search channels. The limits on CP violation arising from the Higgs sector measurements are complementary to those from EDM measurements. Combining all current constraints from low energy to colliders, we set generic upper bounds on the CP violating angle which parametrizes the CP odd component in the 126 GeV Higgs boson.
Rotating Fluids with Self-Gravitation in Bounded Domains

In this paper, we study the steady solutions of Euler-Poisson equations in bounded domains with prescribed angular velocity. This models a rotating Newtonian star consisting of a compressible perfect fluid with given equation of state P=eSργ. When the domain is a ball and the angular velocity is constant, we obtain both existence and non-existence theorems, depending on the adiabatic gas constant γ. In addition we obtain some interesting properties of the solutions; e.g., monotonicity of the radius of the star with both angular velocity and central density. We also prove that the radius of a rotating spherically symmetric star, with given constant angular velocity and constant entropy, is uniformly bounded independent of the central density. This is physically striking and in sharp contrast to the case of the non-rotating star. For general domains and variable angular velocities, both an existence result for the isentropic equations of state and non-existence result for the non-isentropic equation of state are also obtained.
Asymptotic Analysis of Generative Semi-Supervised Learning

Semi-supervised learning has emerged as a popular framework for improving modeling accuracy while controlling labeling cost. Based on an extension of stochastic composite likelihood we quantify the asymptotic accuracy of generative semi-supervised learning. In doing so, we complement distribution-free analysis by providing an alternative framework to measure the value associated with different labeling policies and resolve the fundamental question of how much data to label and in what manner. We demonstrate our approach with both simulation studies and real world experiments using naive Bayes for text classification and MRFs and CRFs for structured prediction in NLP.
GPS-based real-time identification of tire-road friction coefficient

Vehicle control systems such as collision avoidance, adaptive cruise control, and automated lane-keeping systems as well as ABS and stability control systems can benefit significantly from being made "road-adaptive." The estimation of tire-road friction coefficient at the wheels allows the control algorithm in such systems to adapt to external driving conditions. This paper develops a new tire-road friction coefficient estimation algorithm based on measurements related to the lateral dynamics of the vehicle. A lateral tire force model parameterized as a function of slip angle, friction coefficient, normal force and cornering stiffness is used. A real-time parameter identification algorithm that utilizes measurements from a differential global positioning system (DGPS) system and a gyroscope is used to identify the tire-road friction coefficient and cornering stiffness parameters of the tire. The advantage of the developed algorithm is that it does not require large longitudinal slip in order to provide reliable friction estimates. Simulation studies indicate that a parameter convergence rate of 1 s can be obtained. Experiments conducted on both dry and slippery road indicate that the algorithm can work very effectively in identifying a slippery road.
Seasonal labor constraints and intra-household dynamics in the female fields of southern Cameroon

Abstract African agricultural production is modeled as a sequential decision process, with men’s labor first allotted to clearing, then women’s labor allotted to harvesting. A switching regression is then used to measure the constraints due to clearing labor capacity and harvesting labor capacity. The import of men’s clearing labor depends on the valuation of shadow wages. Output appears to be more frequently constrained by husband’s clearing labor, and in this situation male labor appears under-utilized. However, output is also significantly constrained by female harvest labor, although the findings imply that female labor is over-utilized at this stage.
Rest-to-Rest Motion of an Experimental Flexible Structure Subject to Friction: Linear Programming Approach

A linear programming approach designed to eliminate the residual vibration of the two-mass harmonic system subject to friction and undergoing a point-to-point maneuver is implemented. Techniques for non-robust and robust open loop controller design are explored. It is shown that consistent results can be obtained from experiments and the robustness against frequency uncertainty results in reduction in residual vibration as well as steady-state error. I. I NTRODUCTION Linear programming (LP) is a powerful numerical op- timization technique that is able to handle hundreds of constraints efficiently. It requires all constraints and co sts to be linear in the unknown variable. This restriction on the use of LP may seem to eliminate practical use on real engineering problem. It is possible, however, to linearize some complex nonlinear systems to fit the required form of LP (1). It is also possible to manipulate the original proble m definition to fit the LP format as is done in (2), where a nonlinear constraint due to fuel usage is re-written as two linear constraints. In system dynamics, LP can be used on linear discrete systems for time optimal and fuel limited time optimal control (3), (4), (2), where constraints linear in the discr ete input sequence u(k), are imposed to result in an input profile. The significance of friction to the control community is in its effects on positioning systems and velocity tracking operation. Positioning applications include telescopes, an- tennas, machine tools, disk drives and robot arm position- ing. Velocity control is also relevant in machine tool, disk drive and robot arm industrial applications which require the accurate tracking of a pre-determined trajectory. The effect of friction becomes accentuated in the low velocitie s region near the reference position. The majority of work done on control of frictional systems is on rigid body systems. Yang and Tomizuka (5) exploited a simple relationship between a pulse input and the displacement of the rigid body. This utilizes the fact th at the rigid body subject to a pulse input never changes the sign of the velocity and thus the Coulomb friction acts like a bias input. This scheme, known as Pulse Width Control (PWC), is presented in an adaptive control setting where an estimate of the friction is determined in real-time. Wijdeven and Singh (6), modified the PWC approach to increase accuracy in actual discrete implementation of the input. Their technique modulates the pulse height to compensate for a rounded up pulse width and is called Pulse Amplitude Pulse Width Control (PAPWC). Additional schemes developed for rigid body systems include internal-model following error control (7), PID and state feedback linearization control (8) and variable structure control in order to try to handle qualitatively different friction regimes (9), (10). Nonlinear PID contro l has also been developed to overcome the stick-slip behavior
Can Falling Supply Explain the Rising Return to College for Younger Men? A Cohort-Based Analysis

Although the college-high school wage gap for younger U. S. men has doubled over the past 30 years, the gap for older men has remained nearly constant. In the United Kingdom and Canada the college-high school wage gap also increased for younger relative to older men. Using a model with imperfect substitution between similarly educated workers in different age groups, we argue that these shifts reflect changes in the relative supply of highly educated workers across age groups. The driving force behind these changes is the slowdown in the rate of growth of educational attainment that began with cohorts born in the early 1950s in all three countries.
Variational Principles for Stellar Structure

The four equations of stellar structure are reformulated as two alternate pairs of variational principles. Different thermodynamic representations lead to the same hydromechanical equations, but the thermal equations require, not the entropy, but the temperature as the thermal field variable. Our treatment emphasizes the hydrostatic energy and the entropy production rate of luminosity produced and transported. The conceptual and calculational advantages of integral over differential formulations of stellar structure are discussed along with the difficulties in describing stellar chemical evolution by variational principles.
Social Skill and the Theory of Fields

The problem of the relationship between actors and the social structures in which they are embedded is central to sociological theory. This paper suggests that the “new institutionalist” focus on fields, domains, or games provides an alternative view of how to think about this problem by focusing on the construction of local orders. This paper criticizes the conception of actors in both rational choice and sociological versions of these theories. A more sociological view of action, what is called “social skill,” is developed. The idea of social skill originates in symbolic interactionism and is defined as the ability to induce cooperation in others. This idea is elaborated to suggest how actors are important to the construction and reproduction of local orders. I show how its elements already inform existing work. Finally, I show how the idea can sensitize scholars to the role of actors in empirical work.
TRIANGLES, SQUARES AND GEODESICS

In the early 1990s Steve Gersten and Hamish Short proved that compact nonpositively curved triangle complexes have biautomatic fundamental groups and that compact nonpositively curved square complexes have biautomatic fundamental groups. In this paper we report on the extent to which results such as these extend to nonpositively curved complexes built out a mixture of triangles and squares. Since both results by Gersten and Short have been generalized to higher dimensions, this can be viewed as a first step towards unifying Januszkiewicz and Świȧtkowski's theory of simplicial nonpositive curvature with the theory of nonpositively curved cube complexes.
Agent-enabled decision support for information retrieval in technical fields

Information retrieval (IR) is challenging for a non-expert who operates in a technical area such as medical terminology. Since IR is essentially a decision making process, experience with the design of intelligent decision support systems is relevant. Intelligent agents can assist the user during decision making, and, by extension, in IR to locate the desired information. This paper presents an extension to an IR system for a medical application in which the user lacks the descriptive vocabulary needed to retrieve the resources. Agents continuously seek information on behalf of the user and are autonomous, proactive, communicative, mobile, goal-driven and persistent in order to retrieve information on behalf of the user.
Superconformal partition functions and non-perturbative topological strings

We propose a non-perturbative definition for refined topological strings. This can be used to compute the partition function of superconformal theories in 5 dimensions on squashed S5 and the superconformal index of a large number of 6 dimensional (2, 0) and (1, 0) theories, including that of N coincident M5 branes. The result can be expressed as an integral over the product of three combinations of topological string amplitudes. SL(3,Z) modular transformations acting by inverting the coupling constants of the refined topological string play a key role.
Finite difference seismograms for laterally varying marine models

Summary. The method of finite differences is applied to the elastic wave equation to generate synthetic seismograms for laterally varying seafloor structures. The results are compared with borehole seismic data from the Gulf of California (Deep Sea Drilling Project Site 485) in which lines were shot over flat and rough topography. The significant new phenomenon observed in both the synthetic seismograms and the field data is the generation of a ‘double head wave’ due to the interaction of the incident wavefront with the side of a hill and the flat seafoor adjacent to the hill. In these models the hills are on the order of a seismic wavelength in height and steep velocity gradients occur over distances comparable to wavelengths. Ray theoretical methods would not be suitable for studying such structures. True amplitude record sections are obtained by the finite difference method, which show for these models that the head wave generated at the flat seafloor adjacent to the hill is lower in amplitude than if the hill were not present and is lower in amplitude than the head wave generated at the hill. A second feature which is important for borehole receivers is the existence of the ‘direct wave root’ in the upper basement. This energy occurs below the sharp interface when the direct wave impinges on the interface from above. There is no corresponding Snell's law ray path for this energy and the energy is evanescent with depth in the lower medium. The properties of both the double head wave and the direct wave root are clearly demonstrated in the finite difference ‘snapshot’ displays.
The hot galactic corona and the soft X-ray background

I characterize the global distribution of the 3/4 keV band background with a simple model of the hot Galactic corona, plus an isotropic extragalactic background. The corona is assumed to be approximately polytropic (index=5/3) and hydrostatic in the gravitational potential of the Galaxy. The model accounts for X-ray absorption, and is constrained iteratively with the ROSAT all-sky X-ray survey data. Regions where the data deviate significantly from the model represent predominantly the Galactic disk and individual nearby hot superbubbles. The global distribution of the background, outside these regions, is well characterized by the model; the 1σ relative dispersion of the data from the model is ∼15%. The electron density and temperature of the corona near the Sun are ∼1.1×10−3 cm−3 and ∼1.7×106 K. The same model also explains well the 1.5 keV band background. The model prediction in the 1/4 keV band, though largely uncertain, qualitatively shows large intensity and spectral variations of the corona contribution across the sky.
DIRECTED ELECTROCHEMICAL NANOWIRE ASSEMBLY: PRECISE NANOSTRUCTURE ASSEMBLY VIA DENDRITIC SOLIDIFICATION

The electrode-nanowire-target architecture, where the target is a second electrode or, say, a biological cell, is critical to fundamental experiments and high performance devices in low dimensional charge transport and nanomaterials based bio-instrumentation. The relatively new technique of directed electrochemical nanowire assembly, which is based on the diffusion limited process of dendritic solidification, permits the single step fabrication of electrode-nanowire-target assemblies. Hence, this technique is reviewed here in order to assess its current state and to elucidate aspects where further study of the underlying solidification process would be likely to expand its capabilities and applications.
The Growing Segmentation of the Charter School Sector in North Carolina

A defining characteristic of charter schools is that they introduce a strong market element into public education. In this paper, we examine through the lens of a market model the evolution of the charter school sector in North Carolina between 1999 and 2012. We examine trends in the mix of students enrolled in charter schools, the racial imbalance of charter schools, patterns in student match quality by schools’ racial composition, and the distributions of test score performance gains compared to those in traditional public schools. In addition, we use student fixed effects models to examine plausibly causal measures of charter school effectiveness. Our findings indicate that charter schools in North Carolina are increasingly serving the interests of relatively able white students in racially imbalanced schools and that despite improvements in the charter school sector over time, charter schools are still no more effective on average than traditional public schools.
Chiral phosphoramide-catalyzed enantioselective addition of allylic trichlorosilanes to aldehydes. Preparative and mechanistic studies with monodentate phosphorus-based amides.

The addition of allylic trichlorosilanes to benzaldehyde promoted by chiral phosphoramides to give the enantioenriched homoallylic alcohol has been investigated. In a survey of Lewis bases as activators for the addition of allyltrichlorosilane to benzaldehyde, phosphorus-based amides have been found to be the most effective promoters. To achieve asymmetric induction, chiral phosphoric triamides derived from chiral diamines have been developed and applied in the allylation reaction albeit with modest enantioselectivities. The addition of 2-butenylsilanes was highly diastereoselective, suggesting a closed, chairlike transition structure. A detailed mechanistic study has been carried out to probe into the origin of activation. From a combination of nonlinear effects and kinetics studies, the reaction was found to likely involve two phosphoramides in both the rate and stereochemistry determining steps. These studies provided the background for the development of highly selective and reactive catalysts.
The Catholic Church, Human Rights, and Democracy: Convergence and Conflict with the Modern State

����� ��� In Pope Benedict XVI’s address to the Roman Curia of December 22, 2006, he made reference to the Catholic Church’s own journey toward embracing human rights and religious freedom. 1 Perhaps surprisingly to some, he gave credit for this development to the Enlightenment, which he said could count human rights and religious freedom as its “true conquests.” More predictably to most, he reiterated his longstanding criticism of the Enlightenment’s attempt to ground these principles on positivist and skeptical foundations. He argued rather that a constructive synergy of faith and reason was the best foundation for tolerance, human rights, and the preservation of religious freedom. Benedict’s thesis points to an ambivalent historical relationship between the social teachings of the Catholic Church and modern political institutions based on human rights and democracy. It is in part a story of convergence. Gradually, over the course of the twentieth century, then far more rapidly beginning with the Second Vatican Council, following upon several centuries of consistent resistance to the momentum of European politics, the Church came to embrace norms of human rights and democracy reflective of those