cssi/SciSciGPT-SciSciNet huggingface dataset:
Flux–charge duality and topological quantum phase fluctuations in quasi-one-dimensional superconductors

It has long been thought that macroscopic phase coherence breaks down in effectively lower-dimensional superconducting systems even at zero temperature due to enhanced topological quantum phase fluctuations. In quasi- one-dimensional wires, these fluctuations are described in terms of 'quantum phase-slip' (QPS): tunneling of the superconducting order parameter for the wire between states differing by ±2 in their relative phase between the wire's ends. Over the last several decades, many deviations from conventional bulk superconducting behavior have been observed in ultra-narrow superconducting nanowires, some of which have been identified with QPS. While at least some of the observations are consistent with existing theories for QPS, other observations in many cases point to contradictory conclusions or cannot be explained by these theories. Hence, our understanding of the nature of QPS, and its relationship to the various observations, has remained imcomplete. In this paper we present a new model for QPS which takes as its starting point an idea originally postulated by Mooij and Nazarov (2006 Nature Phys. 2 169): that flux-charge duality, a classical symmetry of Maxwell's equations, can be used to relate QPS to the well-known Josephson tunneling of Cooper pairs. Our model provides an alternative, and qualitatively different, conceptual basis for QPS and the phenomena which arise from it in experiments, and it appears to permit for the first time a unified understanding of observations across several different types of experiments and materials systems.
Optical Interconnects for High-Performance Computing

High-performance computing systems are of steadily growing interest to provide new levels of computational capability for an increasing range of applications. The growing use of and dependence on optical interconnects to meet these system's scaling bandwidth demands has given rise to “computercom” as a distinct market segment, alongside the traditional datacom and telecom markets. This paper discusses the trends, requirements, tradeoffs, and potential technologies for this market.
A Critical Evaluation of Three Centrifugal Compressors With Pedigree Data Sets: Part 5—Studies in Component Performance

Evaluation critique des methodes de calcul par rapport a des mesures certifiees dans le cas de trois compresseurs centrifuges. Etude des performances des composants
Am I still too Black for you?: Schooling and secular change in skin tone effects

Analysts disagree about whether the Civil Rights/Black Power eras lessened the influence of skin tone on education. The paper finds that, holding family background constant, the educational disadvantages of dark and very dark blacks persisted between younger and older age cohorts. On the other hand, younger medium skin blacks no longer achieved less schooling than their lighter skin counterparts. This paper implies that, without the decline in skin tone effects for medium brown blacks, the racial gap between age cohorts would have remained larger.
THE GEOMETRY OF THE LOCAL COHOMOLOGY FILTRATION IN EQUIVARIANT BORDISM

We present geometric constructions which realize the local cohomology Þltration in the setting of equivariant bordism, with the aim of understanding free G actions on manifolds. We begin by reviewing the basic construction of the local cohomology Þltration, starting with the Conner-Floyd tom Dieck exact sequence. We deÞne this Þltration geometrically using the language of families of subgroups. We then review Atiyah-SegalWilson K-theory invariants, which are well-suited for studying the manifolds produced by our techniques. We end by indicating potential applications of these ideas.
Positive scalar curvature, diffeomorphisms and the Seiberg-Witten invariants

We study the space of positive scalar curvature (psc) metrics on a 4{manifold, and give examples of simply connected manifolds for which it is disconnected. These examples imply that concordance of psc metrics does not imply isotopy of such metrics. This is demonstrated using a modication of the 1{parameter Seiberg{Witten invariants which we introduced in earlier work. The invariant shows that the dieomorphism group of the underlying 4{manifold is disconnected. We also study the moduli space of positive scalar curvature metrics modulo dieomorphism, and give examples to show that this space can be disconnected. The (non-orientable) 4{manifolds in this case are explicitly described, and the components in the moduli space are distinguished by a Pin c eta invariant.
A Unified Approach to the Daucane and Sphenolobane Bicyclo[5.3.0]decane Core: Enantioselective Total Syntheses of Daucene, Daucenal, Epoxydaucenal B, and 14‐para‐Anisoyloxydauc‐4,8‐diene

Access to the bicyclo[5.3.0]decane core found in the daucane and sphenolobane terpenoids via a key enone intermediate enables the enantioselective total syntheses of daucene, daucenal, epoxydaucenal B, and 14-para-anisoyloxydauc-4,8-diene. Central aspects include a catalytic asymmetric alkylation followed by a ring contraction and ring-closing metathesis to generate the five- and seven-membered rings, respectively.
A study of saturated tensor cone for symmetrizable Kac–Moody algebras

Let $$\mathfrak {g}$$ be a symmetrizable Kac-Moody Lie algebra with the standard Cartan subalgebra $$\mathfrak {h}$$ and the Weyl group $$W$$ . Let $$P_+$$ be the set of dominant integral weights. For $$\lambda \in P_+$$ , let $$L(\lambda )$$ be the integrable, highest weight (irreducible) representation of $$\mathfrak {g}$$ with highest weight $$\lambda $$ . For a positive integer $$s$$ , define the saturated tensor semigroup as $$\begin{aligned} \Gamma _s:= \{(\lambda _1, \dots , \lambda _s,\mu )\in P_+^{s+1}: \exists \, N\ge 1 \,\text {with}\,L(N\mu )\subset L(N\lambda _1)\otimes \dots \otimes L(N\lambda _s)\}. \end{aligned}$$ The aim of this paper is to begin a systematic study of $$\Gamma _s$$ in the infinite dimensional symmetrizable Kac-Moody case. In this paper, we produce a set of necessary inequalities satisfied by $$\Gamma _s$$ . These inequalities are indexed by products in $$H^*(G^{\mathrm{min }}/B; \mathbb {Z})$$ for $$B$$ the standard Borel subgroup, where $$G^{\mathrm{min }}$$ is the ‘minimal’ Kac-Moody group with Lie algebra $$\mathfrak {g}$$ . The proof relies on the Kac-Moody analogue of the Borel-Weil theorem and Geometric Invariant Theory (specifically the Hilbert-Mumford index). In the case that $$\mathfrak {g}$$ is affine of rank 2, we show that these inequalities are necessary and sufficient. We further prove that any integer $$d>0$$ is a saturation factor for $$A^{(1)}_1$$ and 4 is a saturation factor for $$A^{(2)}_2$$ .
Yield Enhancement of Digital Microfluidics-Based Biochips Using Space Redundancy and Local Reconfiguration

As microfluidics-based biochips become more complex, manufacturing yield will have significant influence on production volume and product cost. We propose an interstitial redundancy approach to enhance the yield of biochips that are based on droplet-based microfluidics. In this design method, spare cells are placed in the interstitial sites within the microfluidic array, and they replace neighboring faulty cells via local reconfiguration. The proposed design method is evaluated using a set of concurrent real-life bioassays.
Positron Annihilation Induced Auger Electron Spectroscopy

A review is given on the results of PAES (positron annihilation induced Auger Electron Spectroscopy) studies to data, with a concentration on those results obtained at the University of Texas at Arlington. Low energy positions, trapped in a surface localized state annihilate with core electrons resulting in the emission of Auger electrons. The advantages of PEAS include: (i) the elimination of the very large secondary electron background, and (ii) increased surface selectivity. (AIP)
Chain Binomial Model

The chain binomial model arises from chains of binomial probability mass functions, where each function is conditioned on previous function. Products of these probability mass functions give the probabilities of particular sequences of binomial realizations. This chain structure allows for detailed analysis of physical phenomena that can be represented by chain binomials. The simple chain structure allows for statistical inference based on likelihood theory. The chain binomial model forms the statistical underpinnings of the life table. In addition, the chain binomial model has been important in the analysis of infectious disease spread in small groups such as households. For example, the Reed–Frost model is a chain binomial model where the number of new infectives at some time t depends on the number of infectives and susceptibles at time t − 1. This model has been used to estimate epidemiological parameters for the spread of such diseases as measles, smallpox, and influenza. Keywords: binomial; epidemic model; inference; life table; Markov chain; random mixing; secondary attack rate; stochastic process
Lessons of L’Aquila for Operational Earthquake Forecasting

Editor’s note: The following is the text of an address given at the Public Policy Luncheon of the Seismological Society of America (SSA) Annual Meeting on 19 April 2012. In light of the manslaughter convictions handed down for six earth scientists and a public safety official in an Italian court on 22 October 2012, SRL is publishing the content of this presentation. The recorded presentation can be accessed at www.seismosoc.org/italy/. See SSA’s statement on the convictions in the News and Notes column in this issue of SRL or at http://www.seismosoc.org/news/newsitem.php?id=i20121011183. The L’Aquila earthquake of 6 April 2009 (magnitude 6.3) killed 309 people, injured more than 1500 people, and left tens of thousands homeless. In June 2010, the vice‐director of the Italian Department of Civil Protection (DPC) and six scientists associated with one of its advisory bodies, the Commission on the Forecasting and Prevention of Major Risk, were indicted on charges of criminal manslaughter. After two judicial reviews, the case was ordered to trial, which began last September. The prosecution was completed a few weeks ago, and the trial has now moved into its defense phase. Meanwhile, on the basis of newly revealed wiretaps, which were recorded before the earthquake, charges are being prepared against the former head of the DPC, Guido Bertolaso. The case quickly became a cause celebre among scientists. When news of the prosecutions broke in June 2010, the reaction was furious. The indictments appeared to blame the scientists for not alerting the local population of an impending earthquake—for failure to predict. It is well known that large earthquakes cannot be accurately predicted in the short term. Why would an Italian court try to punish scientists for not doing something they did not (and still do not) know how to do? > It is well known that …
New antithrombin‐based anticoagulants

Clinically used anticoagulants are inhibitors of enzymes involved in the coagulation pathway, primarily thrombin and factor Xa. These agents can be either direct or indirect inhibitors of clotting enzymes. Heparin-based anticoagulants are indirect inhibitors that enhance the proteinase inhibitory activity of a natural anticoagulant, antithrombin. Despite its phenomenal success, current anticoagulation therapy suffers from the risk of serious bleeding. The need for safer and more effective antithrombotic agents clearly exists. The past decade has seen enormous effort directed toward discovering and/or designing new molecules with anticoagulant activity. These new molecules can be classified into (a). antithrombin and its mutants, (b). natural polysaccharides, (c). synthetic modified heparins and heparin-mimics, (d). synthetic oligosaccharides, and (e). synthetic non-sugar antithrombin activators. This review focuses on these efforts in designing or discovering new molecules that act through the antithrombin pathway of anticoagulation.
The statistical physics of iceberg calving and the emergence of universal calving laws

Determining a calving law valid for all glaciological and environmental regimes has proven to be a difficult problem in glaciology. For this reason, most models of the calving process are semi-empirical, with little connection to the underlying fracture processes. In this study, I introduce methods rooted in statistical physics to show how calving laws, valid for any glaciological domain, can emerge naturally as a large-spatial-scale/long-temporal-scale limit of an underlying continuous or discrete fracture process. An important element of the method developed here is that iceberg calving is treated as a stochastic process and that the probability an iceberg will detach in a given interval of time can be described by a probability distribution function. Using limiting assumptions about the underlying probability distribution, the theory is shown to be able to simulate a range of calving styles, including the sporadic detachment of large, tabular icebergs from ice tongues and ice shelves and the more steady detachment of smaller-sized bergs from tidewater/outlet glaciers. The method developed has the potential to provide a physical basis to include iceberg calving into numerical ice-sheet models that can be used to produce more realistic estimates of the glaciological contribution to sea-level rise.
Exploring the ethicality of firing employees who blog

This exploratory study evaluates the ethical considerations related to employees fired for their blogging activities. Specifically, subject evaluations of two employee-related blogging scenarios were investigated with established ethical reasoning and moral intensity scales, and a measure of corporate ethical values was included to assess perceptions of organizational ethics. The first scenario involved an employee who was fired because of innocuous blogging, while the second vignette involved an employee who was fired because of work-related blogging. Survey data were collected from employed college students and working practitioners. The findings indicated that the subjects' ethical judgments that firing an employee for blogging was unethical were negatively related to unethical intentions to fire an employee for blogging. Moral intensity was positively related to ethical judgments and negatively related to unethical intentions to fire an employee for blogging, while individual perceptions of ethical values were negatively associated with unethical intentions. Finally, subjects perceived that terminating an employee for innocuous blogging that did not target an employer was more ethically intense than was firing an employee for work-related blogging. The implications of the findings for human resource professionals are discussed, as are the study's limitations and suggestions for future research. © 2010 Wiley Periodicals, Inc.
Thermal-aware methodology for repeater insertion in low-power VLSI circuits

In this paper, the impact of thermal effects on low-power repeater insertion methodology is studied. An analytical methodology for thermal-aware repeater insertion that includes the electrothermal coupling between power, delay, and temperature is presented, and simulation results with global interconnect repeaters are discussed for 90nm and 65nm technology. Simulation results show that the proposed thermal-aware methodology can save 17.5% more power consumed by the repeaters compared to a thermal-unaware methodology for a given allowed delay penalty. In addition, the proposed methodology also results in a lower chip temperature, and thus, extra leakage power savings from other logic blocks.
Delegation of Authority as an Optimal (In)complete Contract

This paper contributes to the literature on the foundations of incomplete contracts. In a holdup framework, we provide two sets of conditions under which simple delegation of authority is the solution to the complete-contracting problem. In cases where overinvestment can be ruled out, delegation is optimal if the payoffs of the parties satisfy certain separability conditions. If overinvestment might be an issue, delegation (possibly with restricted competencies) is optimal if additionally some continuity requirements are met. The paper also contributes to the literature on delegation, where such replication results have previously been derived in settings with asymmetric information.
Physical modeling of the piano

A project aimed at constructing a physical model of the piano is described. Our goal is to calculate the sound produced by the instrument entirely from Newton's laws. The structure of the model is described along with experiments that augment and test the model calculations. The state of the model and what can be learned from it are discussed.
RESTRICTING THE WEAK‐GENERATIVE CAPACITY OF SYNCHRONOUS TREE‐ADJOINING GRAMMARS

The formalism of synchronous tree-adjoining grammars, a variant of standard tree-adjoining grammars (TAG), was intended to allow the use of TAGs for language transduction in addition to language specification. In previous work, the definition of the transduction relation defined by a synchronous TAG was given by appeal to an iterative rewriting process. The rewriting definition of derivation is problematic in that it greatly extends the expressivity of the formalism and makes the design of parsing algorithms difficult if not impossible. We introduce a simple, natural definition of synchronous tree-adjoining derivation, based on isomorphisms between standard tree-adjoining derivations, that avoids the expressivity and implementability problems of the original rewriting definition. The decrease in expressivity, which would otherwise make the method unusable, is offset by the incorporation of an alternative definition of standard tree-adjoining derivation, previously proposed for completely separate reasons, thereby making it practical to entertain using the natural definition of synchronous derivation. Nonetheless, some remaining problematic cases call for yel more flexibility in the definition; the isomorphism requirement may have to be relaxed. It remains for future research to rune the exact requirements on the allowable mappings.
Some Intrinsic Features of Hydroxylamines, Oximes and Hydroxamic Acids: Integration of Theory and Experiment

1 Introduction 2 Analysis of Covalent and Noncovalent Interactions 3 Computational Approach 4 Lone Pair–Lone Pair Repulsion 5 Comparison of Prototypical Examples 6 Oxime Isomerism 7 Hydrogen Bonding 8 Acidity/Basicity 9 Global and Local Polarizability 10 Conclusion 11 Acknowledgment Keywords: intrinsic features of hydroxylamines, oximes and hydroxamic acids-theory and experiment; covalent and noncovalent interaction analysis; ionization energy; surface electrostatic potential, and its most positive and most negative values; lone pair–lone pair repulsion; computational approach; hydroxylamines, oximes and hydroxamic acids-with adjacent nitrogen and oxygen atoms; oxime isomerism
INVESTING IN FOREIGN CURRENCY IS LIKE BETTING ON YOUR INTERTEMPORAL MARGINAL RATE OF SUBSTITUTION

Investors earn positive excess returns on high interest rate foreign discount bonds, because these currencies appreciate on average. Lustig and Verdelhan (2005) show that investing in high interest rate foreign discount bonds exposes them to more aggregate consumption risk, while low interest rate foreign bonds provide a hedge. This paper provides a simple model that replicates these facts. Investing in foreign currency is like betting on the difference between your own intertemporal marginal rate of substitution (IMRS) and your neighbor’s IMRS. These bets are very risky if your neighbor’s IMRS is not correlated with yours, but they provide a hedge when his IMRS is highly correlated and more volatile. If the foreign neighbors that face low interest rates also have more volatile and correlated IMRS, that accounts for the spread in excess returns in the data. (JEL: F31, G12)
Adaptive force control of position/velocity controlled robots: theory and experiment

This paper addresses the problem of achieving exact dynamic force control with manipulators possessing low-level position and/or velocity controllers typically employed in industrial robot arms. Previously reported approaches and experimental results are reviewed. A new adaptive force control algorithm for velocity/position controlled robot arms in contact with surfaces of unknown linear compliance is reported. The controller provably guarantees global asymptotic convergence of force trajectory tracking errors to zero when the robot is under exact or asymptotically exact inner loop velocity control. An additional result which guarantees arbitrarily small force errors for bounded inner loop velocity tracking errors is presented. Comparative experiments show the new adaptive velocity (position) based controller and its nonadaptive counterpart to provide performance superior to that of previously reported position-based force controllers.
Managing Student Behavior with Class-Wide Function-Related Intervention Teams: An Observational Study in Early Elementary Classrooms

Comprehensive evidence-based interventions are needed to help early childhood educators manage challenging student behaviors. One such intervention, class-wide function-related intervention teams (CW-FIT), is a multi-tiered behavioral intervention program based on positive behavior support principles, including four main elements: (a) teaching socially appropriate communication skills, (b) using differential reinforcement with an interdependent group contingency, (c) extinguishing or eliminating potential reinforcement for problem behavior, and (d) implementing individual interventions using self-management, help cards, and/or functional assessment. This study implemented CW-FIT with five kindergarten through second grade teachers. Results demonstrated efficacy of the program as early childhood teachers increased their praise rates and decreased their reprimand rates, and students responded with increased on-task behavior and fewer classroom disruptions. Study implications and limitations are addressed.
Correcting Object-Related Misconceptions: How Should The System Respond?

This paper describes a computational method for correcting users' misconceptions concerning the objects modelled by a computer system. The method involves classifying object-related misconceptions according to the knowledge-base feature involved in the incorrect information. For each resulting class sub-types are identified, according to the structure of the knowledge base, which indicate what information may be supporting the misconception and therefore what information to include in the response. Such a characterization, along with a model of what the user knows, enables the system to reason in a domain-independent way about how best to correct the user.
Control of Ablation Depth and Surface Structure in P3 Scribing of Thin-Film Solar Cells by a Picosecond Laser

In this paper, precise P3 scribing of thin-film solar cells (AZO/CIGS/Mo/Glass) via a picosecond laser is investigated. A parametric study is carried out for P3 scribing to study the effects of laser fluence and overlap ratio on ablation depth and slot quality, supported by the numerical prediction using a two-temperature model. The optimum scribing conditions are determined, and the potential processing speed is increased. Laser induced periodic surface structures are also presented after the scribing process, which can potentially enhance the absorption of the cell surface and consequently increase the cell efficiency.Copyright © 2014 by ASME
Understanding racial differences in marital disruption: Recent trends and explanations

We use data from the Current Population Survey to investigate racial differences in recent patterns of marital disruption. Although a leveling in the trend of disruption has occurred for White women since 1980, our results suggest less stabilization in rates of disruption among Black women. We also observe significant differences by race in the effects of key compositional factors on the risk of marital disruption, including age at marriage, education, premarital childbearing, and region of residence. Differences in population composition with respect to these characteristics, however, cannot alone explain the overall racial gap in disruption.
Simple free star-autonomous categories and full coherence

Abstract This paper gives a simple presentation of the free star-autonomous category over a category, based on Eilenberg–Kelly–MacLane graphs and Trimble rewiring, yielding a full coherence theorem: the commutativity of diagrams of canonical maps is decidable.
Anisotropic Field-of-Views in Radial Imaging

Radial imaging techniques, such as projection-reconstruction (PR), are used in magnetic resonance imaging (MRI) for dynamic imaging, angiography, and short- imaging. They are robust to flow and motion, have diffuse aliasing patterns, and support short readouts and echo times. One drawback is that standard implementations do not support anisotropic field-of-view (FOV) shapes, which are used to match the imaging parameters to the object or region-of-interest. A set of fast, simple algorithms for 2-D and 3-D PR, and 3-D cones acquisitions are introduced that match the sampling density in frequency space to the desired FOV shape. Tailoring the acquisitions allows for reduction of aliasing artifacts in undersampled applications or scan time reductions without introducing aliasing in fully-sampled applications. It also makes possible new radial imaging applications that were previously unsuitable, such as imaging elongated regions or thin slabs. 2-D PR longitudinal leg images and thin-slab, single breath-hold 3-D PR abdomen images, both with isotropic resolution, demonstrate these new possibilities. No scan time to volume efficiency is lost by using anisotropic FOVs. The acquisition trajectories can be computed on a scan by scan basis.
Effects of Shape and Spin on the Tidal Disruption of P/Shoemaker-Levy 9

I derive an approximate criterion for the tidal disruption of a “rubble pile” body as it passes close to a planet (or the sun): $$ \rho _{c} \approx \left [ 2 \rho_{p} \left ( {R_{p}} \over {r} \right )^{3} + \left ( {\omega} \over \omega_{0} \right )^{2} \right ] \left ( {a} \over {b} \right ), $$ where ρ c is the critical density below which the body will be disrupted, ρ p is the density of the planet (or sun), R p is the radius of the planet, r is the periapse distance, ω is the rotation frequency of the body, ω0 is the surface orbit frequency about a body of unit density, and a/b is the axis ratio of the body, considered as a prolate ellipsoid. For P/Shoemaker Levy 9, in its passage close to Jupiter in 1992, this expression suggests that the critical density is ∼1.2 for a spherical, non-spinning nucleus, but could be >2.5 for a 2:1 elongate body with a typical rotation period of ∼10 hours.
FOR-PROFIT CONVERSION OF BLUE CROSS PLANS: Public Benefit or Public Harm?

Conversions of Blue Cross plans to for-profit status have the potential to remake the corporate landscape of health care finance. Absent regulatory intervention, current trends could easily result in more than half of Blue Cross subscribers being in for-profit plans, a phenomenon far more significant than the conversion of nonprofit hospitals. Therefore, regulators' deliberations over conversion proposals are beginning to focus on the health policy impacts. This chapter surveys the full range of health policy implications by analyzing all existing studies of Blue Cross conversions and reporting on the authors' own case studies of conversion impacts. These studies conclude that conversions have not caused major negative impacts on the availability or accessibility of health care in the states in which conversions have occurred so far. However, a great deal of uncertainty exists about the actual effects of previous conversions, and each state is unique; therefore, even if the historical record were clear, it is difficult to predict with great certainty what the actual effects will be in another state undergoing a Blue conversion.
Analysis and optimization of transmission schedules for single-hop WDM networks

Considers single-hop lightwave networks with stations interconnected using wave division multiplexing. The stations are equipped with tunable transmitters and/or receivers. A predefined, wavelength-time oriented schedule specifies the slots and the wavelengths on which communication between any two pairs of stations is allowed to take place. The authors define a wide variety of schedules and develop a general framework for analyzing their throughput performance for any number of available wavelengths, any tunability characteristics, and general (potentially nonuniform) traffic patterns. They then consider the optimization of schedules given the traffic requirements and present optimization heuristics that give near-optimal results. They also investigate how the number of available wavelengths (channels) affects the system throughput, and develop techniques to efficiently share the available channels among the network stations. As a result, they obtain systems that are easy to scale while having very good performance. >
Controls on capital inflows and external shocks

The author attempts to analyze whether price-based controls on capital inflows are successful in insulating economies against external shocks. He presents results from vector auto regressive (VAR) models that indicate that Chile and Colombia, countries that adopted controls on capital inflows, seem to have been relatively well insulated against external disturbances. Subsequently, he uses the auto regressive distributed lag (ARDL) approach to co-integration to isolate the effects of the capital controls on the pass-through of external disturbances to domestic interest rates in those economies. The author concludes that there is evidence that the capital controls allowed for greater policy autonomy.
The quantum speed limit

How fast can a quantum system evolve? We answer this question focusing on the role of entanglement and interactions among subsystems. In particular, we analyze how the order of the interactions shapes the dynamics.
Up sector of minimal flavor violation: top quark properties and direct D meson CP violation

Minimal Flavor Violation in the up-type quark sector leads to particularly interesting phenomenology due to the interplay of flavor physics in the charm sector and collider physics from flavor changing processes in the top sector. We study the most general operators that can affect top quark properties and D meson decays in this scenario, concentrating on two CP violating operators for detailed studies. The consequences of these effective operators on charm and top flavor changing processes are generically small, but can be enhanced if there exists a light flavor mediator that is a Standard Model gauge singlet scalar and transforms under the flavor symmetry group. This flavor mediator can satisfy the current experimental bounds with a mass as low as tens of GeV and explain observed D-meson direct CP violation. Additionally, the model predicts a non-trivial branching fraction for a top quark decay that would mimic a dijet resonance.
Fault-Tolerant Relay Node Placement in Heterogeneous Wireless Sensor Networks

Existing work on placing additional relay nodes in wireless sensor networks to improve network connectivity typically assumes homogeneous wireless sensor nodes with an identical transmission radius. In contrast, this paper addresses the problem of deploying relay nodes to provide fault tolerance with higher network connectivity in heterogeneous wireless sensor networks, where sensor nodes possess different transmission radii. Depending on the level of desired fault tolerance, such problems can be categorized as: 1) full fault-tolerant relay node placement, which aims to deploy a minimum number of relay nodes to establish k(k ? 1) vertexdisjoint paths between every pair of sensor and/or relay nodes and 2) partial fault-tolerant relay node placement, which aims to deploy a minimum number of relay nodes to establish k(k ? 1) vertex-disjoint paths only between every pair of sensor nodes. Due to the different transmission radii of sensor nodes, these problems are further complicated by the existence of two different kinds of communication paths in heterogeneous wireless sensor networks, namely, two-way paths, along which wireless communications exist in both directions; and one-way paths, along which wireless communications exist in only one direction. Assuming that sensor nodes have different transmission radii, while relay nodes use the same transmission radius, this paper comprehensively analyzes the range of problems introduced by the different levels of fault tolerance (full or partial) coupled with the different types of path (one-way or two-way). Since each of these problems is NP-hard, we develop O(?k2)-approximation algorithms for both one-way and two-way partial fault-tolerant relay node placement, as well as O(?k3)-approximation algorithms for both one-way and two-way full fault-tolerant relay node placement (? is the best performance ratio of existing approximation algorithms for finding a minimum k-vertex connected spanning graph). To facilitate the applications in higher dimensions, we also extend these algorithms and derive their performance ratios in d-dimensional heterogeneous wireless sensor networks (d ? 3). Finally, heuristic implementations of these algorithms are evaluated via QualNet simulations.
Tall or taller, pretty or prettier: is discrimination absolute or relative?

Using microeconomic data sets from the United States and the Netherlands, this study considers how agents perceive characteristics that are discriminated against. It uses the examples of beauty and height to examine whether: 1) Absolute or relative differences in a characteristic affect labor-market and other outcomes; and 2) The effects of a characteristic change when all agents acquire more of it. Decision-makers seem to respond more to absolute than to relative differences among individuals. Weaker results show that an increase in the mean of a characteristic’s distribution does not alter market responses to differences in it.
The Linear Regression Model with Autocorrelated Errors: Just Say No to Error Autocorrelation

This paper focuses on the practice of serial correlation correcting of the Linear Regression Model (LRM) by modeling the error. Simple Monte Carlo experiments are used to demonstrate the following points regarding this practice. First, the common factor restrictions implicitly im posed on the temporal structure ofyt and xt appear to be completely unreasonable for any real world application. Second, when one compares the Autocorrelation-Corrected LRM (ACLRM) model estimates with those from the (unrestricted) Dynamic Linear Regression Model (DLRM) encompassing the ACLRM, there is no significant gain in efficiency! Third, as expected, when the common factor restrictions do not hold the LRM model gives poor estimates of the true parameters and estimation of the ACLRM simply gives rise to different misleading results! On the other hand, estimates from the DLRM and the corresponding VAR model are very reliable. Fourth, the power of the usual Durbin Watson test (DW) of autocorrelation is much higher when the common factor restrictions do hold than when they do not. But, a more general test of autocorrelation is shown to perform almost as well as the DW when the common factor restrictions do hold and significantly better than the DW when the restrictions do not hold. Fifth ,w e demonstrate that the simple F-test suggested by Davidson and MacKinnon (1993) is quite powerful.
Poly-Many Hardcore Bits for Any One-Way Function and a Framework for Differing-Inputs Obfuscation

We show how to extract an arbitrary polynomial number of simultaneously hardcore bits from any one-way function. In the case the one-way function is injective or has polynomially-bounded pre-image size, we assume the existence of indistinguishability obfuscation (iO). In the general case, we assume the existence of differing-input obfuscation (diO), but of a form weaker than full auxiliary-input diO. Our construction for injective one-way functions extends to extract hardcore bits on multiple, correlated inputs, yielding new D-PKE schemes. Of independent interest is a definitional framework for differing-inputs obfuscation in which security is parameterized by circuit-sampler classes.
Constraints on the ubiquity of coronal X-ray cycles

Stellar activity cycles are known to be a widespread phenomenon amongst moderately active solar- and late-type stars from long-term periodic variations in chromospheric Ca II H and K emission lines, yet to date, only a handful of coronal X-ray cycles are known. We have surveyed serendipitously observed stellar sources in fields observed multiple times in the last decade by XMM-Newton and present our analysis of nine stars from six fields. Since our sample is flux-limited, it is strongly biased toward higher levels of X-ray activity. We fit a single temperature APEC spectrum to each source and search for significant periodicities using a Lomb-Scargle periodogram. We use a Monte Carlo (MC) algorithm to yield robust analysis of the statistical significance of cycle detections and non-detections. None of the nine stellar light curves show any convincing indications of periodicity. From MC simulations, we simulate the detection capabilities of our methodology and, assuming a uniform distribution of cycle periods and strengths over the domain searched, we conclude with 95% confidence that less than 72% of the stars represented by our sample of active stars have 5-13 year coronal X-ray cycles.
Local frequency dependence in transcranial ultrasound transmission

The development of large-aperture multiple-source transducer arrays for ultrasound transmission through the human skull has demonstrated the possibility of controlled and substantial acoustic energy delivery into the brain parenchyma without the necessitation of a craniotomy. The individual control of acoustic parameters from each ultrasound source allows for the correction of distortions arising from transmission through the skull bone and also opens up the possibility for electronic steering of the acoustic focus within the brain. In addition, the capability to adjust the frequency of insonation at different locations on the skull can have an effect on ultrasound transmission. To determine the efficacy and applicability of a multiple-frequency approach with such a device, this study examined the frequency dependence of ultrasound transmission in the range of 0.6-1.4 MHz through a series of 17 points on four ex vivo human skulls. Effects beyond those that are characteristic of frequency-dependent attenuation were examined. Using broadband pulses, it was shown that the reflected spectra from the skull revealed information regarding ultrasound transmission at specific frequencies. A multiple-frequency insonation with optimized frequencies over the entirety of five skull specimens was found to yield on average a temporally brief 230% increase in the transmitted intensity with an 88% decrease in time-averaged intensity transmission within the focal volume. This finding demonstrates a potential applicability of a multiple-frequency approach in transcranial ultrasound transmission.
THE QUANTIZED GEOMETRY OF VISUAL SPACE: THE COHERENT COMPUTATION OF DEPTH, FORM, AND LIGHTNESS

Abstract A theory is presented of how global visual interactions between depth, length, lightness, and form percepts can occur. The theory suggests how quantized activity patterns which reflect these visual properties can coherently fill-in, or complete, visually ambiguous regions starting with visually informative data features. Phenomena such as the Cornsweet and Craik-O'Brien effects, phantoms and subjective contours, binocular brightness summation, the equidistance tendency, Emmert's law, allelotropia, multiple spatial frequency scaling and edge detection, figure-ground completion, coexistence of depth and binocular rivalry, reflectance rivalry, Fechner's paradox, decrease of threshold contrast with increased number of cycles in a grating pattern, hysteresis, adaptation level tuning, Weber law modulation, shift of sensitivity with background luminance, and the finite capacity of visual short term memory are discussed in terms of a small set of concepts and mechanisms. Limitations of alternative visual theories which depend upon Fourier analysis, Laplacians, zero-crossings, and cooperative depth planes are described. Relationships between monocular and binocular processing of the same visual patterns are noted, and a shift in emphasis from edge and disparity computations toward the characterization of resonant activity-scaling correlations across multiple spatial scales is recommended. This recommendation follows from the theory's distinction between the concept of a structural spatial scale, which is determined by local receptive field properties, and a functional spatial scale, which is defined by the interaction between global properties of a visual scene and the network as a whole. Functional spatial scales, but not structural spatial scales, embody the quantization of network activity that reflects a scene's global visual representation. A functional scale is generated by a filling-in resonant exchange, or FIRE, which can be ignited by an exchange of feedback signals among the binocular cells where monocular patterns are binocularly matched.
Reduction of CuO and Cu2O with H2: H embedding and kinetic effects in the formation of suboxides

Time-resolved X-ray diffraction, X-ray absorption fine structure, and first-principles density functional calculations were used to investigate the reaction of CuO and Cu(2)O with H(2) in detail. The mechanism for the reduction of CuO is complex, involving an induction period and the embedding of H into the bulk of the oxide. The in-situ experiments show that, under a normal supply of hydrogen, CuO reduces directly to metallic Cu without formation of an intermediate or suboxide (i.e., no Cu(4)O(3) or Cu(2)O). The reduction of CuO is easier than the reduction of Cu(2)O. The apparent activation energy for the reduction of CuO is about 14.5 kcal/mol, while the value is 27.4 kcal/mol for Cu(2)O. During the reduction of CuO, the system can reach metastable states (MS) and react with hydrogen instead of forming Cu(2)O. To see the formation of Cu(2)O, one has to limit the flow of hydrogen, slowing the rate of reduction to allow a MS --> Cu(2)O transformation. These results show the importance of kinetic effects for the formation of well-defined suboxides during a reduction process and the activation of oxide catalysts.
Information invariants for distributed manipulation

In Donald (1995), we described a manipulation task for coop erating mobile robots that can push large, heavy objects. There, we asked whether explicit local and global communication between the agents can be removed from a family of pushing protocols. In this article, we answer in the affirmative. We do so by using the general methods of Donald (1995), analyzing information invariants.We discuss several measures for the information complexity of the task: (1) How much internal state should the robot retain? (2) How many cooperating agents are required, and how much communication between them is necessary? (3) How can the robot change (side effect) the environment to record state or sensory information for performing a task? (4) How much information is provided by sensors? and (5) How much computation is required by the robot? To answer these questions, we develop a notion of information invariants. We develop a technique whereby one sensor can be constructed from others by adding, deleting, and reallocati...
Sensitive ultrashort pulse chirp measurement

The chirp of an ultrashort laser pulse can be extracted with high accuracy from a modified spectrum auto-interferometric correlation waveform by using a new time domain algorithm that allows signal averaging. We display results revealing high sensitivity to chirp even with signal-to-noise levels approaching unity. Correction algorithms have been developed to accommodate signal distortion arising from bandwidth limitations, interferometer misalignment, and nonquadratic detector response.
Concentration of Eigenfunctions Near a Concave Boundary

This article concerns the concentration of Dirichlet eigenfunctions of the Laplacian on a compact two-dimensional Riemannian manifold with strictly geodesically concave boundary. We link three inequalities which bound the concentration in different ways. We also prove one of these inequalities, which bounds the L p norms of the restrictions of eigenfunctions to broken geodesics.
A path to value creation for foreign entrepreneurs

Research summary: Firms founded by foreign entrepreneurs constitute an influential and growing part of the world economy. Yet, the existing research has given little consideration to the strategies of foreign entrepreneurs beyond their decisions to start a firm. In this article, we address this gap by examining how foreign entrepreneurs may bring value to their firms as firm managers. We argue that foreign owner-managers may benefit their firms by having access to home-country resources. We demonstrate that, compared to hired local managers, foreign owner-managers reduce firms' operating costs by disproportionately hiring home-country labor when this labor is more cost-efficient. This effect is larger for labor-intensive industries and for entrepreneurs from less wealthy countries. Managerial summary: Foreign entrepreneurs represent an important part of the world economy. Yet, we know little of how foreign entrepreneurs manage their firms. In this article, we examine whether foreign entrepreneurs and domestic managers hire different employees. We find that when foreign entrepreneurs manage their firms personally, they hire a larger number of foreign workers, and such workers are cheaper and more productive than the local labor. Conversely, domestic managers tend to hire local employees, despite their higher relative wages. Foreign owner-managers are particularly valuable in labor-intensive industries and when their home-country labor is inexpensive. Copyright © 2015 John Wiley & Sons, Ltd.
Accurate solution of the paraxial wave equation using Richardson extrapolation

Richardson extrapolation is used along with the midstep Euler finite difference method to solve the paraxial wave equation. Highly accurate solutions can be efficiently obtained using this combined approach. Numerical results are presented for wave propagation in a straight integrated optical waveguide and a Y-junction waveguide. Discretization errors in both the propagation and the transverse dimension can be systematically eliminated by using Richardson extrapolation. Accuracies on the order of 10/sup /spl minus/11/ or better are obtained. >
Throughput measurement using a synthetic job stream

Managers of computer facilities frequently need to be able to measure the throughput of their installations. Throughput is based on the amount of work a system can perform in a given time in a particular environment, and is usually measured as the reciprocal of the running time of selected jobs. The throughput of a computer system is a function of the hardware configuration, the operating system software and the workload characteristics. Once the characteristics of the workload are identified, the configuration and operating system can be optimized in terms of throughput for that environment. Improvements resulting from system changes can be evaluated using throughput measurements.