cssi/SciSciGPT-SciSciNet huggingface dataset:
Catalytic, asymmetric synthesis of α-phenoxy-β-aryl-β-lactams

The reactions of phenoxyacetyl chloride with aryl imines in the presence of catalytic quantities of a silyl cinchona alkaloid and an achiral Lewis acid affords α-phenoxy-β-aryl-β-lactams. These reactions presumably proceed by way of ketene or acyl ammonium enolate intermediates. These reactions occur in a high enantioselectivity regardless of the nature of the Lewis acid, however, a high diastereoselectivity depended on the use of a hindered lanthanide complex as the Lewis acidic co-catalyst.
Consciousness in culture-based conflict and conflict resolution

This article makes the case for bringing theory of consciousness to the understanding of individual transformation in conflict resolution practice. It does so by highlighting consciousness engaged explicitly and implicitly in many conflict resolution practices and consciousness dynamics considered in the emerging literature by conflict resolution practitioners. In particular, increasing awareness, consciousness structures, shifts in consciousness, transitional space, and embodied engagement are useful frameworks for understanding individual transformation within conflict resolution processes. The article concludes that the study of conflict resolution is incomplete without consideration of consciousness in conflict and conflict resolution. Furthermore, formally engaging consciousness dynamics as part of the study of conflict resolution holds promise for improving conflict resolution practice.
Finite-Horizon Parameterizing Manifolds, and Applications to Suboptimal Control of Nonlinear Parabolic PDEs

This article proposes a new approach for the design of low-dimensional suboptimal controllers to optimal control problems of nonlinear partial differential equations (PDEs) of parabolic type. The approach fits into the long tradition of seeking for slaving relationships between the small scales and the large ones (to be controlled) but differ by the introduction of a new type of manifolds to do so, namely the finite-horizon parameterizing manifolds (PMs). Given a finite horizon [0,T] and a low-mode truncation of the PDE, a PM provides an approximate parameterization of the high modes by the controlled low ones so that the unexplained high-mode energy is reduced--in a mean-square sense over [0,T]--when this parameterization is applied. Analytic formulas of such PMs are derived by application of the method of pullback approximation of the high-modes introduced in Chekroun et al. (2014). These formulas allow for an effective derivation of reduced systems of ordinary differential equations (ODEs), aimed to model the evolution of the low-mode truncation of the controlled state variable, where the high-mode part is approximated by the PM function applied to the low modes. The design of low-dimensional suboptimal controllers is then obtained by (indirect) techniques from finite-dimensional optimal control theory, applied to the PM-based reduced ODEs. A priori error estimates between the resulting PM-based low-dimensional suboptimal controller $u_{R}^{\ast}$ and the optimal controller u? are derived under a second-order sufficient optimality condition. These estimates demonstrate that the closeness of $u_{R}^{\ast}$ to u? is mainly conditioned on two factors: (i) the parameterization defect of a given PM, associated respectively with the suboptimal controller $u_{R}^{\ast}$ and the optimal controller u?; and (ii) the energy kept in the high modes of the PDE solution either driven by $u_{R}^{\ast}$ or u? itself. The practical performances of such PM-based suboptimal controllers are numerically assessed for optimal control problems associated with a Burgers-type equation; the locally as well as globally distributed cases being both considered. The numerical results show that a PM-based reduced system allows for the design of suboptimal controllers with good performances provided that the associated parameterization defects and energy kept in the high modes are small enough, in agreement with the rigorous results.
Predictions for a planet just inside Fomalhaut's eccentric ring

We propose that the eccentricity and sharpness of the edge of Fomalhaut’s disk are due to a planet just interior to the ring edge. The collision timescale consistent with the disk opacity is long enough that spiral density waves cannot be driven near the planet. The ring edge is likely to be located at the boundary of a chaotic zone in the corotation region of the planet. We find that this zone can open a gap in a particle disk as long as the collision timescale exceeds the removal or ejection timescale in the zone. We use the slope measured from the ring edge surface brightness profile to place an upper limit on the planet mass. The removal timescale in the chaotic zone is used to estimate a lower limit. The ring edge has eccentricity caused by secular perturbations from the planet. These arguments imply that the planet has a mass between that of Neptune and that of Saturn, a semi-major axis of approximately 119 AU and longitude of periastron and eccentricity, 0.1, the same as that of the ring edge.
Thermodynamic screening of metal-substituted MOFs for carbon capture

Metal–organic frameworks (MOFs) have emerged as promising materials for carbon capture applications due to their high CO2 capacities and tunable properties. Amongst the many possible MOFs, metal-substituted compounds based on M-DOBDC and M-HKUST-1 have demonstrated amongst the highest CO2 capacities at the low pressures typical of flue gasses. Here we explore the possibility for additional performance tuning of these compounds by computationally screening 36 metal-substituted variants (M = Be, Mg, Ca, Sr, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, W, Sn, and Pb) with respect to their CO2 adsorption enthalpy, ΔHT=300K. Supercell calculations based on van der Waals density functional theory (vdW-DF) yield enthalpies in good agreement with experimental measurements, out-performing semi-empirical (DFT-D2) and conventional (LDA & GGA) functionals. Our screening identifies 13 compounds having ΔH values within the targeted thermodynamic window −40 ≤ ΔH ≤ −75 kJ mol−1: 8 are based on M-DODBC (M = Mg, Ca, Sr, Sc, Ti, V, Mo, and W), and 5 on M-HKUST-1 (M = Be, Mg, Ca, Sr and Sc). Variations in the electronic structure and the geometry of the structural building unit are examined and used to rationalize trends in CO2 affinity. In particular, the partial charge on the coordinatively unsaturated metal sites is found to correlate with ΔH, suggesting that this property may be used as a simple performance descriptor. The ability to rapidly distinguish promising MOFs from those that are “thermodynamic dead-ends” will be helpful in guiding synthesis efforts towards promising compounds.
Learning human arm movements by imitation:: Evaluation of a biologically inspired connectionist architecture

This paper evaluates a model of human imitation of abstract, two-arm movements. The model consists of a hierarchy of artificial neural networks, which are abstractions of brain regions involved in visuo-motor control. The model is validated in a biomechanical simulation of a 37 degrees of freedom (DOF) humanoid. Input to the model are data from human arm movements recorded using video and marker-based tracking systems. Results show a high qualitative and quantitative agreement with human data. The model’s reproduction is better or comparable to that of human subjects imitating the same movements. © 2001 Published by Elsevier Science B.V. 11 12 13 14 15 16
New approaches to bounding the multiplicity of an ideal

Abstract We use the theory of resolutions for a given Hilbert function to investigate the multiplicity conjectures of Huneke and Srinivasan, and Herzog and Srinivasan. To prove the conjectures for all modules with a particular Hilbert function, we show that it is enough to prove the statements only for elements at the bottom of the partially ordered set of resolutions with that Hilbert function. This enables us to test the conjectured upper bound for the multiplicity efficiently with the computer algebra system Macaulay 2, and we verify the upper bound for many Artinian modules in three variables with small socle degree. Moreover, with this approach, we show that though numerical techniques have been sufficient in several of the known special cases, they are insufficient to prove the conjectures in general. Finally, we apply a result of Herzog and Srinivasan on ideals with a quasipure resolution to prove the upper bound for Cohen–Macaulay quotients by ideals with generators in high degrees relative to the regularity.
Combinatorial Methods for Detecting Surface Subgroups in Right-Angled Artin Groups

We give a short proof of the following theorem of Sang-hyun Kim: if 𝐴(Γ) is a right-angled Artin group with defining graph Γ, then 𝐴(Γ) contains a hyperbolic surface subgroup if Γ contains an induced subgraph 𝐶𝑛 for some 𝑛≥5, where 𝐶𝑛 denotes the complement graph of an 𝑛-cycle. Furthermore, we give a new proof of Kim's cocontraction theorem.
Thermal analysis of the beam missteering in APS storage ring

Several bending magnet beam missteering cases have been investigated for the 7-GeV storage ring of the Advanced Photon Source (APS). One of the critical missteering events is presented in this paper. Finite element analyses are performed to solve for both temperature and stress fields. Thermally induced deflections are determined by utilizing beam bending theory. A safe current limit is established for the storage ring chambers. >
Low SNR Capacity of Fading Channels with Peak and Average Power Constraints

Flat-fading channels that are correlated in time are considered under peak and average power constraints. For discrete-time channels, a new upper bound on the capacity per unit time is derived. A low SNR analysis of a full-scattering vector channel is used to derive a complimentary lower bound. Together, these bounds allow us to identify the exact scaling of channel capacity for a fixed peak to average ratio, as the average power converges to zero. The upper bound is also asymptotically tight as the average power converges to zero for a fixed peak power. For a continuous time infinite bandwidth channel, Viterbi identified the capacity for M-FSK modulation. Recently, Zhang and Laneman showed that the capacity can be achieved with non-bursty signaling (QPSK). An additional contribution of this paper is to obtain similar results under peak and average power constraints.
INFERENCE OF SIGNS OF INTERACTION EFFECTS IN SIMULTANEOUS GAMES WITH INCOMPLETE INFORMATION

This paper studies the inference of interaction effects in discrete simultaneous games with incomplete information. We propose a test for the signs of state-dependent interaction effects that does not require parametric specifications of players' payoffs, the distributions of their private signals, or the equilibrium selection mechanism. The test relies on the commonly invoked assumption that players' private signals are independent conditional on observed states. The procedure is valid in (but does not rely on) the presence of multiple equilibria in the data-generating process (DGP). As a by-product, we propose a formal test for multiple equilibria in the DGP. We also implement the test using data on radio programming of commercial breaks in the United States, and infer stations' incentives to synchronize their commercial breaks. Our results support the earlier finding by Sweeting (2009) that stations have stronger incentives to coordinate and air commercials at the same time during rush hours and in smaller markets.
Limits and the System of Near-Numbers.

The paper details a comprehensive system for the treatment of the topic of limits—conceptually, computationally, and formally. The system addresses fundamental linguistic flaws in the standard presentation of limits, which attempts to force limit discussion into the language of individual real numbers and equality. The system of near-numbers properly fits the context of limits, allowing precise and unambiguous notation in limit computation. More importantly, the near-numbers are a set of concrete mathematical objects that provide a scaffold both for building an accurate intuitive understanding of the limit concept and for connecting that understanding to the formal definition of the limit.
Phaeosphaeride A, an Inhibitor of STAT3-Dependent Signaling Isolated from an Endophytic Fungus

Phaeosphaeride A, a nitrogen-containing bicyclic compound produced by an endophytic fungus, inhibits signaling by the transcription factor STAT3.
Quantum sized, thiolate-protected gold nanoclusters

The scientific study of gold nanoparticles (typically 1–100 nm) has spanned more than 150 years since Faraday's time and will apparently last longer. This review will focus on a special type of ultrasmall (<2 nm) yet robust gold nanoparticles that are protected by thiolates, so-called gold thiolate nanoclusters, denoted as Aun(SR)m (where, n and m represent the number of gold atoms and thiolate ligands, respectively). Despite the past fifteen years' intense work on Aun(SR)m nanoclusters, there is still a tremendous amount of science that is not yet understood, which is mainly hampered by the unavailability of atomically precise Aun(SR)m clusters and by their unknown structures. Nonetheless, recent research advances have opened an avenue to achieving the precise control of Aun(SR)m nanoclusters at the ultimate atomic level. The successful structural determination of Au102(SPhCOOH)44 and [Au25(SCH2CH2Ph)18]q (q = −1, 0) by X-ray crystallography has shed some light on the unique atomic packing structure adopted in these gold thiolate nanoclusters, and has also permitted a precise correlation of their structure with properties, including electronic, optical and magnetic properties. Some exciting research is anticipated to take place in the next few years and may stimulate a long-lasting and wider scientific and technological interest in this special type of Au nanoparticles.
Dynamics in hybrid complex systems of switches and oscillators

While considerable progress has been made in the analysis of large systems containing a single type of coupled dynamical component (e.g., coupled oscillators or coupled switches), systems containing diverse components (e.g., both oscillators and switches) have received much less attention. We analyze large, hybrid systems of interconnected Kuramoto oscillators and Hopfield switches with positive feedback. In this system, oscillator synchronization promotes switches to turn on. In turn, when switches turn on, they enhance the synchrony of the oscillators to which they are coupled. Depending on the choice of parameters, we find theoretically coexisting stable solutions with either (i) incoherent oscillators and all switches permanently off, (ii) synchronized oscillators and all switches permanently on, or (iii) synchronized oscillators and switches that periodically alternate between the on and off states. Numerical experiments confirm these predictions. We discuss how transitions between these steady state solutions can be onset deterministically through dynamic bifurcations or spontaneously due to finite-size fluctuations.
USING STATE ADMINISTRATIVE DATA TO MEASURE PROGRAM PERFORMANCE

We use administrative data from Missouri to examine the sensitivity of earnings impact estimates for a job training program based on alternative nonexperimental methods. We consider regression adjust- ment, Mahalanobis distance matching, and various methods using propensity-score matching, examining both cross-sectional estimates and difference-in-difference estimates. Specification tests suggest that the difference-in-difference estimator may provide a better measure of pro- gram impact. We find that propensity-score matching is most effective, but the detailed implementation is not of critical importance. Our analyses demonstrate that existing data can be used to obtain useful estimates of program impact.
Total synthesis and structure validation of (+)-bistramide C

The convergent total synthesis of the marine natural product (+)-bistramide C confirms the a priori assignments of its relative and absolute configurations, which were originally based on the combined application of [α]D analysis, NMR, and synthesis.
Low-Cost Radiation Shielding for Use in Mapping the Thermal Environments of Rangeland Animals

Variations in its thermal environment can influence how an animal utilizes a rangeland landscape. Mapping the spatial and temporal air temperature patterns throughout a landscape may be helpful in predicting range animal distribution and habitat use. Many sampling points are required to effectively map air temperature levels throughout extensive and topographically diverse rangelands. Self-contained air temperature data loggers are commercially available, but these require shielding from solar radiation to provide accurate measurements. Commercial shields are expensive and fragile. A low-cost, robust, and effective alternative to commercial shields is needed for air temperature mapping applications. Two types of shields, vented cylinder and inverted-U shaped, were constructed from PVC pipe. Temperature loggers protected in either of these shielding types provided more accurate air temperature measurements than unshielded loggers. Temperature measurements from loggers protected by inverted-U shields were within 62.58C of a reference instrument in 94.7% of 2 496 observations. About 86.2% of observations acquired by loggers within vented-cylinder shields were within 62.58C of the reference. Conversely, only 66.1% of the measurements from unshielded loggers were within 62.58C of the reference. Both shielding types were designed to be attached to a swiveling mounting system, thus avoiding damage by animals and eliminating the need for protective exclosure fencing. Materials costs for constructing either shield type, including the mounting system, were $8.00 or less. In contrast, commercially available radiation shields with mounting hardware cost $75.00 or more. Compared to the use of commercial shielding, construction and deployment of these PVC-pipe shields would reduce the cost, time, and labor required to collect accurate air temperature data at many points across an extensive landscape.
Few-body semiclassical approach to nucleon transfer and emission reactions

A three-body semiclassical model is proposed to describe the nucleon transfer and emission reactions in a heavy-ion collision. In this model the two heavy particles, i.e. nuclear cores A1(ZA1 , MA1 ) and A2(ZA2 , MA2 ), move along classical trajectories � R1(t) and �2(t) respectively, while the dynamics of the lighter neutron (n) is considered from a quantum mechanical point of view. Here, Mi are the nucleon masses and Zi are the Coulomb charges of the heavy nuclei (i = 1, 2). A Faddeev-type semiclassical formu- lation using realistic paired nuclear-nuclear potentials is applied so that all three chan- nels (elastic, rearrangement and break-up) are described in a unified manner. In order to solve the time-dependent equations the Faddeev components of the total three-body wave-function are expanded in terms of the input and output channel target eigenfunc- tions. In the special case, when the nuclear cores are identical (A1 ≡ A2) and also the two-level approximation in the expansion over the target (subsystem) functions is used, the time-dependent semiclassical Faddeev equations are resolved in an explicit way. To determine the realistic �1(t) and � R2(t) trajectories of the nuclear cores, a self-consistent approach based on the Feynman path integral theory is applied.
Learning-based symbolic assume-guarantee reasoning with automatic decomposition

Compositional reasoning aims to improve scalability of verification tools by reducing the original verification task into subproblems. The simplification is typically based on the assume-guarantee reasoning principles, and requires decomposing the system into components as well as identifying adequate environment assumptions for components. One recent approach to automatic derivation of adequate assumptions is based on the L* algorithm for active learning of regular languages. In this paper, we present a fully automatic approach to compositional reasoning by automating the decomposition step using an algorithm for hypergraph partitioning for balanced clustering of variables. We also propose heuristic improvements to the assumption identification phase. We report on an implementation based on NuSMV, and experiments that study the effectiveness of automatic decomposition and the overall savings in the computational requirements of symbolic model checking.
Hydrocarbyl ligand derivatives of group 6-group 9 heterometallic clusters

Abstract The synthesis and reactivity of group 6-group 9 heterometallic clusters containing hydrocarbon ligands is reviewed. A variety of methods has been employed in the synthesis of this class of clusters. These methods are organized into several general reaction types: metal exchange reactions, the reactions between dinuclear compounds, reactions utilizing mononuclear metal alkylidynes, and condensation reactions with other mononuclear reagents. The reactions of the resulting heterometallic clusters with alkynes, protons and carbon electrophiles, and miscellaneous substitution reactions are discussed. Applications in catalysis are briefly summarized.
Air- and water-stable catalysts for hydroamination/cyclization. Synthesis and application of CCC-NHC pincer complexes of Rh and Ir.

The scope of CCC−NHC pincer complex synthetic methodology by metalation/transmetalation has been extended to Ir. Structural characterization revealed that it is isomorphous with the Rh complex. Both Rh and Ir complexes are efficient catalysts for the hydroamination/cyclization of secondary amines in the presence of air and/or water.
What to do When Your Hessian is Not Invertible: Alternatives to Model Respecification in Nonlinear Estimation

What should a researcher do when statistical analysis software terminates before completion with a message that the Hessian is not invertible? The standard textbook advice is to respecify the model, but this is another way of saying that the researcher should change the question being asked. Obviously, however, computer programs should not be in the business of deciding what questions are worthy of study. Although noninvertable Hessians are sometimes signals of poorly posed questions, nonsensical models, or inappropriate estimators, they also frequently occur when information about the quantities of interest exists in the data through the likelihood function. The authors explain the problem in some detail and lay out two preliminary proposals for ways of dealing with noninvertable Hessians without changing the question asked.
X‐ray evidence for multiphase hot gas with solar abundances in the brightest elliptical galaxies

We examine whether isothermal models of the hot gas can successfully describe the ASCA and ROSAT spectra of NGC 1399, 4472, 4636 and 5044, which are among the brightest elliptical galaxies in X-rays. Broad-band spectral fitting of the ASCA SIS and GIS data accumulated within a radius of ∼5 arcmin for each galaxy shows that isothermal models (which also include a component for discrete sources) are unable to fit the SIS data near 1 keV, although a marginal fit for NGC 4636 is obtained if the relative abundances of several elements with respect to Fe are allowed to depart substantially from their solar values. In addition, these isothermal models typically fail to produce the large equivalent widths of the Kα line blends of Si and S that are measured independently of the Fe L emission lines. Two-temperature models provide substantially better broad-band fits to both the SIS and GIS data of each galaxy with the relative abundances (except for NGC 4636) fixed at their solar values. A simple multiphase cooling flow model fits nearly as well as the two-temperature model for NGC 1399, 4472 and 5044. The multiphase models also predict more accurately the Si and S equivalent widths and the ratios of Si xiv/xiii and S xvi/xv than the isothermal models. From detailed comparison of broad-band fits to the ASCA data of these ellipticals using the MEKAL and Raymond–Smith plasma codes, we determine that the MEKAL plasma code (as expected) is significantly more accurate for the important energies ∼0.7–1.4 keV, and the small residuals in the Fe L region for the best-fitting multiphase models imply that remaining inaccuracies in the MEKAL code are insufficient to change qualitatively the results for data of the present quality. Using various approaches, we find that the temperature gradients inferred from the ROSAT PSPC data of these galaxies, especially for NGC 1399 and 5044, are inconsistent with the isothermal models obtained from fitting the ASCA data within a single aperture, but are very consistent with the multiphase models. Therefore, models that assume isothermal gas within r∼5 arcmin are inconsistent with the ASCA and ROSAT PSPC data of these elliptical galaxies. Simple two-temperature models and multiphase cooling flows provide much better descriptions of these data sets with Fe abundances of ∼1–2 solar and (except for NGC 4636) relative abundances fixed at their solar values. We discuss the implications of these nearly solar abundances.
Shuffling by semi-random transpositions

In the cyclic-to-random shuffle, we are given n cards arranged in a circle. At step k, we exchange the kth card along the circle with a uniformly chosen random card. The problem of determining the mixing time of the cyclic-to-random shuffle was raised by Aldous and Diaconis in 1986. Mironov used this shuffle as a model for the cryptographic system known as RC4, and proved an upper bound of O(n log n) for the mixing time. We prove a matching lower bound, thus establishing that the mixing time is indeed of order /spl Theta/(n log n). We also prove an upper bound of O(n log n) for the mixing time of any "semirandom transposition shuffle", i.e., any shuffle in which a random card is exchanged with another card chosen according to an arbitrary (deterministic or random) rule. To prove our lower bound, we exhibit an explicit complex-valued test function which typically takes very different values for permutations arising from few iterations of the cyclic-to-random-shuffle and for uniform random permutations. Perhaps surprisingly, the proof hinges on the fact that the function e/sup z/ - 1 has nonzero fixed points in the complex plane. A key insight from our work is the importance of complex analysis tools for uncovering structure in nonreversible Markov chains.
Dark energy, matter creation and curvature

The most studied way to explain the current accelerated expansion of the universe is to assume the existence of dark energy; a new component that fills the universe, does not form clumps, currently dominates the evolution, and has a negative pressure. In this work I study an alternative model proposed by Lima et al. (Abramo and Lima in Class. Quantum Gravity 13:2953, 1996; Zimdahl in Phys. Rev. D 53:5483, 1996; Zimdahl and Pavon in Mon. Not. R. Astron. Soc. 266:872, 1994), which does not need an exotic equation of state, but assumes instead the existence of gravitational particle creation. Because this model fits the supernova observations as well as the ΛCDM model, I perform in this work a thorough study of this model, considering an explicit spatial curvature. I found that in this scenario we can alleviate the cosmic coincidence problem, basically showing that these two components, dark matter and dark energy, are of the same nature, but they act at different scales. I also shown the inadequacy of some particle creation models, and I study a previously proposed new model that overcomes these difficulties.
MULTIPLE SOLUTIONS OF THE TRANSONIC POTENTIAL FLOW EQUATION

The two-dimensional transonic potential flow equation, when solved in discrete form for steady flow over an airfoil, has been found to yield more than one solution in certain bands of angle of attack and Mach number. The most striking ex- ample of this is the appearance of nonsymmetric solutions with large positive or negative lift, for symmetric airfoils at zero angle of attack. The behavior of these "anomalous" solutions is exam- ined as grid size is varied by large factors and found to be not qualitatively different from that of %ormalrf solutions (outside the nonuniqueness band). Thus it appears that the effect is not due to discretization error, and that the basic tran- sonic potential flow partial differential equation admits nonunique solutions for certain values of angle of attack and Mach number.
Great Expectations and the End of the Depression

What ended the Great Depression in the United States? This paper suggests that the recovery was driven by a shift in expectations. This shift was triggered by President Franklin Delano Roosevelt’s (FDR) policy actions. On the monetary policy side, Roosevelt abolished the gold standard and announced an explicit policy objective of inflating the price level to pre-Depression levels. On the fiscal policy side, Roosevelt expanded real and deficit spending which helped make his policy objective credible . The key to the recovery was the successful management of expecta tions about future policy . Roosevelt’s rise to power is modeled as a policy regime change , as in Thomas Sargent (1983) and Peter Temin and Barry Wigmore (1990). This paper formalizes Temin and Wigmore’s argu ment in a repeated game setting using a dynamic stochastic general equilibrium (DSGE) model and argues that the regime change can account for the recovery. In the model, a regime change means the elimination of certain “policy dogmas” that constrain the actions of the government. The regime change generates an endogenous shift in expectations due to a coordination of mon etary and fiscal policy. This coordination ended the Great Depression by engineering a shift in expectations from “contractionary” (i.e., the private sector expected future economic contrac tion and deflation) to “expansionary” (i.e., the public expected future economic expansion and inflation). The expectation of higher future inflation lowered real interest rates, thus stimulating demand, while the expectation of higher future income stimulated demand by raising permanent income.
Practical Interests, Relevant Alternatives, and Knowledge Attributions: An Empirical Study

In defending his interest-relative account of knowledge, Jason Stanley relies heavily on intuitions about several bank cases. We experimentally test the empirical claims that Stanley seems to make concerning our common-sense intuitions about these cases. Additionally, we test the empirical claims that Jonathan Schaffer seems to make, regarding the salience of an alternative, in his critique of Stanley. Our data indicate that neither raising the possibility of error nor raising stakes moves most people from attributing knowledge to denying it. However, the raising of stakes (but not alternatives) does affect the level of confidence people have in their attributions of knowledge. We argue that our data impugn what both Stanley and Schaffer claim our common-sense judgments about such cases are.
Exchange Rates and UIP Violations at Short and Long Horizons

The much-studied Uncovered Interest Rate Parity (UIP) puzzle, the observation that exchange rates do not adjust sufficiently to offset interest rate differentials, is more complicated than commonly understood. It changes nature with the horizon. I conrm existing short-run evidence that high interest rate currencies depreciate less than predicted by the interest rate differential. But, building on Engel ( 2015 ), at longer horizons (4 to 7 years) Ind a reverse puzzle: high interest rate currencies depreciate too much. Interestingly, the long-horizon excess depreciation leads exchange rates to converge to the UIP benchmark over the long-run. I propose a novel model, based on the mechanism of bond convenience yields, that can explain both the short and the long horizon UIP violations. The model presents interesting new links between ex- change rates and monetary-�scal interaction. I also provide direct empirical evidence that supports the mechanism.
Dividends, Asymmetric Information, and Agency Conflicts: Evidence from a Comparison of the Dividend Policies of Japanese and U.S. Firms

We compare dividend policies of U.S. and Japanese firms, partitioning the Japanese data into keiretsu, independent, and hybrid firms. We examine the correlation between dividend changes and stock returns, and the reluctance to change dividends. Results are consistent with the joint hypotheses that Japanese firms, particularly keiretsu-member firms, face less information asymmetry and fewer agency conflicts than U.S. firms, and that information asymmetries and/or agency conflicts affect dividend policy. Japanese firms experience smaller stock price reactions to dividend omissions and initiations, they are less reluctant to omit and cut dividends, and their dividends are more responsive to earnings changes. CORPORATE GOVERNANCE IN JAPAN differs dramatically from the dominant form of corporate governance in the United States. According to Gerlach (1992), large Japanese firms have strategic and stable equity cross holdings with other firms, reciprocity in trade and financial relations, and close ties to their banks.1 Within Japan, though, corporate governance is not homogeneous. Some firms operate within industrial groups, or keiretsu, while others are independent. Keiretsu member firms differ from independent firms in the breadth and depth of cross-firm ties, and in the size and scope of their network's reach. In 1990, members of the six largest keiretsu groups accounted for 17.8 percent of total sales in Japan.2 The close ties between managers and investors in Japanese firms, and in keiretsu firms especially, substantially reduce information asymmetries and
Frost Temperature Relations for Defrosting Sensing System

To develop a better defrosting control system on finned evaporators of a refrigeration system, a study is conducted to better quantify the frosting and defrosting processes by using an infrared thermometer to determine the frost surface temperature. For gradual frost deposition a slow variation in surface emissivity is expected, while the defrosting process is characterized by a sudden change of this property. As an indicator for the defrosting initiation control mechanism, the times at which the IR signals stabilize at different conditions (Reynolds number, cold surface temperature, and ambient temperature) are reported along with the terminal mass concentration of a defined frosting process. On the other hand, the abrupt variation of surface emissivity indicates the termination of the defrosting process. Removable fins are used to measure frost weight, and a video microscope is used to determine the frost thickness
IMPSAC: synthesis of importance sampling and random sample consensus

This paper proposes a new method for recovery of epipolar geometry and feature correspondence between images which have undergone a significant deformation, either due to large rotation or wide baseline of the cameras. The method also encodes the uncertainty by providing an arbitrarily close approximation to the posterior distribution of the two view relation. The method operates on a pyramid from coarse to fine resolution, thus raising the problem of how to propagate information from one level to another in a statistically consistent way. The distribution of the parameters at each resolution is encoded nonparametrically as a set of particles. At the coarsest level, a random sample consensus Monte Carlo Markov chain (RANSAC-MCMC) estimator is used to initialize this set of particles, the posterior can then be approximated as a mixture of Gaussians fitted to these particles. The distribution at a coarser level influences the distribution at a finer level using the technique of sampling-importance-resampling (SIR) and MCMC, which allows for asymptotically correct approximations of the posterior distribution. The estimate of the posterior distribution at the level above is being used as the importance sampling function to generate a new set of particles, which can be further improved by MCMC. It is shown that the method is superior to previous single resolution RANSAC-style feature matchers.
A quasi-analytical interpolation method for pricing American options under general multi-dimensional diffusion processes

We present a quasi-analytical method for pricing multi-dimensional American options based on interpolating two arbitrage bounds, along the lines of Johnson in J Financ Quant Anal 18(1):141–148 (1983). Our method allows for the close examination of the interpolation parameter on a rigorous theoretical footing instead of empirical regression. The method can be adapted to general diffusion processes as long as quick and accurate pricing methods exist for the corresponding European and perpetual American options. The American option price is shown to be approximately equal to an interpolation of two European option prices with the interpolation weight proportional to a perpetual American option. In the Black-Scholes model, our method achieves the same efficiency as the quadratic approximation of Barone-Adesi and Whaley in J Financ 42:301–320 (1987), with our method being generally more accurate for out-of-the-money and long-maturity options. When applied to Heston’s stochastic volatility model, our method is shown to be extremely efficient and fairly accurate.
A Physically Universal Cellular Automaton

Several cellular automata (CA) are known to be universal in the sense that one can simulate arbitrary computations (e.g., circuits or Turing machines) by carefully encoding the computational device and its input into the cells of the CA. In this paper, we consider a different kind of universality proposed by Janzing. A cellular automaton is physically universal if it is possible to implement any transformation on a finite region of the CA by initializing the complement of the region and letting the system evolve. We give the first known example of a physically universal CA, answering an open problem of Janzing and opening the way for further research in this area.
Viscoelastic Response of the Thorax under Dynamic Belt Loading

Objective: Three postmortem human surrogates (PMHS) were positioned and rigidly mounted through the spine to a tabletop test fixture for the purpose of characterizing thoracic response to diagonal belt loading with well-defined boundary conditions. Methods: These PMHS were mounted to a stationary apparatus that supported the spine and shoulders in a configuration comparable to that seen in a 48 km/h automobile sled test at the time of maximum chest deformation. A belt restraint was positioned across the anterior torso with attachments at D-ring and buckle locations based on the geometry of a mid-sized sedan. The belt was attached to a trolley driven by a hydraulic ram linked to a universal test machine. Ramp and hold experiments were conducted at rates of 0.5, 0.9, and 1.2 m/s and hold times of 60 s. Ramp-hold displacement waveforms of up to 20 percent of the chest depth were applied to the chest while the resulting belt loads and spinal reaction loads were recorded. These data were used to identify param...
Empirical and theoretical evaluation of active probing attacks and their countermeasures

A variety of remote sensing attacks allow adversaries to break flow confidentiality and gather mission-critical information in distributed systems. Such attacks are easily supplemented by active probing attacks, where additional workload (e.g., ping packets) is injected into the victim system. This paper presents statistical pattern recognition as a fundamental technology to evaluate the effectiveness of active probing attacks. Our theoretical analysis and empirical results show that even if sophisticated approaches of link padding are used, sample entropy of probing packets’ round trip time is an effective and robust feature statistic to discover the user payload traffic rate, which is important for maintaining anonymous communication. Extensive experiments on local network, campus network, and the Internet were carried out to validate the system security predicted by the theoretical analysis. We give some guidelines to reduce the effectiveness of such active probing attacks.
Microstructure and thermal history of metal particles in CH chondrites

We have studied metal microstructures in four CH chondrites, Patuxent Range (PAT) 91546, Allan Hills (ALH) 85085, Acfer 214, and Northwest Africa (NWA) 739, to examine details of the thermal histories of individual particles. Four types of metal particles are common in all of these chondrites. Zoned and unzoned particles probably formed as condensates from a gas of chondritic composition in a monotonic cooling regime, as has been shown previously. We have demonstrated that these particles were cooled rapidly to temperatures below 500 K after they formed, and that condensation effectively closed around 700 K. Zoned and unzoned particles with exsolution precipitates, predominantly high-Ni taenite, have considerably more complex thermal histories. Precipitates grew in reheating episodes, but the details of the heating events vary among individual grains. Reheating temperatures are typically in the range 800-1000 K. Reheating could have been the result of impact events on the CH parent body. Some particles with precipitates may have been incorporated into chondrules, with further brief heating episodes taking place during chondrule formation. In addition to the four dominant types of metal particles, rare Ni-rich metal particles and Si-rich metal particles indicate that the metal assemblage in CH chondrites was a mixture of material that formed at different redox conditions. Metal in CH chondrites consists of a mechanical mixture of particles that underwent a variety of thermal histories prior to being assembled into the existing brecciated meteorites.
The Effectiveness of Juvenile Correctional Facilities: Public versus Private Management*

Abstract This paper uses data on juvenile offenders released from correctional facilities in Florida to explore the effects of facility management type (private for‐profit, private nonprofit, public state‐operated, and public county‐operated) on recidivism outcomes and costs. The data provide detailed information on individual characteristics, criminal and correctional histories, judge‐assigned restrictiveness levels, and home zip codes—allowing us to control for the nonrandom assignment of individuals to facilities far better than any previous study. Relative to all other management types, for‐profit management leads to a statistically significant increase in recidivism, but relative to nonprofit and state‐operated facilities, for‐profit facilities operate at a lower cost to the government per comparable individual released. Cost‐benefit analysis implies that the short‐run savings offered by for‐profit over nonprofit management are negated in the long run due to increased recidivism rates, even if one me...
Formal Symplectic Groupoid of a Deformation Quantization

We give a self-contained algebraic description of a formal symplectic groupoid over a Poisson manifold M. To each natural star product on M we then associate a canonical formal symplectic groupoid over M. Finally, we construct a unique formal symplectic groupoid ‘with separation of variables’ over an arbitrary Kahler-Poisson manifold.
Melting behavior of (Mg,Fe)O solid solutions at high pressure

[1] High pressure melting of (Mg,Fe)O ferropericlase, the second most abundant mineral in the Earth's lower mantle, is of fundamental importance for understanding the chemical differentiation, geodynamics and thermal evolution of the Earth's interior. We report the first systematic experimental study of melting behavior in the MgO-FeO system up to 3600 K and 7 GPa, indicating the ideal solution between solid and liquid (Mg,Fe)O in the MgO-rich portion. The zero pressure melting slope of MgO is ∼221 K/GPa derived from our resistance heating measurements, which is several times higher than the value from the previous measurements in a CO2-laser heated diamond anvil cell, but consistent with the theoretically predicted melting curves. Our results combined with the previous first-principles simulations suggest that the melting temperature of MgO-rich (Mg,Fe)O is significantly higher than the geotherm through the lower mantle and this would place an upper bound on the solidus of the lower mantle.
Neural Computations Mediating One-Shot Learning in the Human Brain

Incremental learning, in which new knowledge is acquired gradually through trial and error, can be distinguished from one-shot learning, in which the brain learns rapidly from only a single pairing of a stimulus and a consequence. Very little is known about how the brain transitions between these two fundamentally different forms of learning. Here we test a computational hypothesis that uncertainty about the causal relationship between a stimulus and an outcome induces rapid changes in the rate of learning, which in turn mediates the transition between incremental and one-shot learning. By using a novel behavioral task in combination with functional magnetic resonance imaging (fMRI) data from human volunteers, we found evidence implicating the ventrolateral prefrontal cortex and hippocampus in this process. The hippocampus was selectively “switched” on when one-shot learning was predicted to occur, while the ventrolateral prefrontal cortex was found to encode uncertainty about the causal association, exhibiting increased coupling with the hippocampus for high-learning rates, suggesting this region may act as a “switch,” turning on and off one-shot learning as required.
Methylation of the γ-Catenin Gene is Associated With Poor Prognosis of Renal Cell Carcinoma

Purpose: g-Catenin is a cell adhesion protein, and its functional loss is associated with tumor invasion and metastasis. We hypothesize that (1) promoter CpG methylation regulates the expression and function of the g-catenin gene in renal cell carcinoma (RCC) and (2) methylation of the g-catenin gene is associated with poor prognosis of RCC. To test these hypotheses, we analyzed the CpG methylation status of the g-catenin gene and its correlation with clinical outcome in RCC. Experimental Design: Genomic DNA and total RNA were extracted from three renal cancer cell lines (A498, Caki-1, and Caki-2) and 54 RCC tissue samples with their corresponding normal kidney tissue samples. Expression of g-catenin gene was analyzed by reverse transcription-PCR and immunostaining. Promoter methylation was analyzed by two different methylation-specific PCR (MSP-A and MSP-B), and the results were verified by DNA sequencing. Results: The demethylating agent (5-aza-2V-deoxycytidine) increased levels of mRNA transcript of the g-catenin gene in three renal cancer cell lines. g-Catenin mRNA and protein expression were significantly reduced in RCC samples compared with normal kidney samples, respectively (P < 0.05). MSP-A and MSP-B bands were detected in 45 of 54 (83.3%) and 49 of 54 (90.7%) RCC samples, respectively. In normal kidney, weak products of MSP-A and MSP-B were detected in 5 of 54 (9.3%) and 6 of 54 (11.1%) samples, respectively. Likewise, both MSP-A and MSP-B ratios were significantly higher in RCC samples compared with normal kidney samples, respectively (P < 0.01). Multivariate analysis revealed that the MSP-B ratio was a powerful and independent predictor superior to nuclear grade and Robson stage with respect to survival and disease progression (P = 0.029 and 0.0071, respectively). No mutations in the NH2-terminal region of g-catenin were found in this study. Conclusion: Expression of g-catenin is regulated by promoter CpG methylation, and the balance between methylated and unmethylated RCC cell populations could determine its functional role. Because the conventional nuclear grade and/or staging system have some limitations to predict precise clinical outcome, this is the first report demonstrating that promoter CpG methylation of g-catenin can be an independent and superior predictor for survival and disease progression.