cssi/SciSciGPT-SciSciNet huggingface dataset:
Extracting Acyclic Dependency Models from Quality Standards for COTS Software Evaluation

Commercial off-the-shelf (COTS) software has become a crucial component of many of today’s mission- and safety-critical products. As these products have proliferated internationally, global demand for software safety and performance quality has increased. Unfortunately, the current state-of-the-art in software assessment technology has not matured to the point where well-established and widely accepted schemes for evaluating COTS software quality have been presented. Without insight into the source code, COTS software users depend on a subjective assessment of attributes described by performance metrics, behavioral descriptions, and/or historical product data. Published techniques that attempt to formalize the above approach are often less than successful due to ill-defined and subjective metrics, and the naive assumption of independence between attributes. Recently, software standards have been seen as a means of improving the evaluation process by providing an acknowledged criterion for software metric comparison. Given the stated issues, is it possible to develop a standards-based dependency model of well-defined attributes that does not depend on naive assumptions? The answer to this question is yes. This paper describes a process that can be used to extract acyclic dependency models, if they exist, from various software product quality standards. Application of the extraction process will be used to reveal the attribute dependency model of the international software standard ISO/IEC 9126-1. Not only can this process be used for COTS software evaluation, but it can also be used by standards making bodies to clarify the reasoning, justifications and causal implications they employ when developing standards.
Metal-catalyzed alkynylation of (bromophenyl)-oligophenylene. A rapid route to thermoset precursors of high density monolithic glass-like carbon

Abstract : The functionalization of (bromophenyl)oligophenylene with several alkynes is described. The bromide groups on the oligomer were replaced with terminal alkynes using a Pd/Cu catalysts system. Substitution of nearly all the original bromide locations was achieved. The functionalized oligomers, freely soluble in THF, exhibited high char yields on thermolysis to 900 deg C under a nitrogen atmosphere. Several of the functionalized oligomers flowed on heating. The oligomer that was functionalized with phenylacetylene exhibited a well-defined melting point at 190 deg C and acetylenic coupling did not take place until 310 deg C. The hot oligomer flowed to form a monolith of glassy carbon. Depending on the alkyne used, a range of densities from 1.39-1.95 g/cc could be obtained in the final carbon glass. The structure/property relationships and the material applications are discussed.
Mars Exploration Entry, Descent, and Landing Challenges

The United States has successfully landed five robotic systems on the surface of Mars. These systems all had landed mass below 0.6 metric tons (t), had landed footprints on the order of hundreds of km and landed at sites below -1 km MOLA elevation due the need to perform entry, descent and landing operations in an environment with sufficient atmospheric density. Current plans for human exploration of Mars call for the landing of 40-80 t surface elements at scientifically interesting locations within close proximity (10's of m) of pre-positioned robotic assets. This paper summarizes past successful entry, descent and landing systems and approaches being developed by the robotic Mars exploration program to increased landed performance (mass, accuracy and surface elevation). In addition, the entry, descent and landing sequence for a human exploration system will be reviewed, highlighting the technology and systems advances required.
Protective interface specifications

The interface specification of a procedure describes the procedure's behaviour using pre- and postconditions. These pre- and postconditions are written using various functions. If some of these functions are partial, or underspecified, then the procedure specification may not be well-defined. We show how to write pre- and postcondition specifications that avoid such problems, by having the precondition “protect” the postcondition from the effects of partiality and underspecification. We formalize the notion of protection from partiality in the context of specification languages like VDM-SL and COLD-K. We also formalize the notion of protection from underspecification for the Larch family of specification languages, and for Larch show how one can prove that a procedure specification is protected from the effects of underspecification.
Hydrodynamic Instability in an Extended Landau/Levich Model of Liquid-Propellant Combustion at Normal and Reduced Gravity

Abstract The classical Landau/Levich models of liquid-propellant combustion, despite their relative simplicity, serve as seminal examples that correctly describe the onset of hydrodynamic instability in reactive systems. Recently, these two separate models have been combined and extended to account for a dynamic dependence, absent in the original formulations, of the local burning rate on the local pressure and temperature fields. The resulting model admits an extremely rich variety of both hydrodynamic and reactive/diffusive instabilities that can be analyzed either numerically or analytically in various limiting parameter regimes. In the present work, a formal asymptotic analysis, based on the realistic smallness of the gas-to-liquid density ratio, is developed to investigate the combined effects of gravity and other parameters on the hydrodynamic instability of the propagating liquid/gas interface. In particular, an analytical expression is derived for the neutral stability boundary A p ( k ), where A p is the pressure sensitivity of the burning rate and k is the wavenumber of the disturbance. The results demonstrate explicitly the stabilizing effect of gravity on long-wave disturbances, the stabilizing effect of viscosity (both liquid and gas) and surface tension on short-wave perturbations, and the instability associated with intermediate wavenumbers for critical negative values of A p . In the limiting case of weak gravity, it is shown that hydrodynamic instability in liquid-propellant combustion is a long-wave instability phenomenon, whereas at normal gravity, this instability is first manifested through O(1) wavenumber disturbances. It is also demonstrated that, in general, surface tension and the viscosity of both the liquid and gas phases each produce comparable stabilizing effects in the large-wavenumber regime, thereby providing important modifications to previous analyses in which one or more of these effects were neglected.
Scattering theory on SL(3)/SO(3): connections with quantum 3-body scattering

In this paper we continue our program of extending the methods of geometric scattering theory to encompass the analysis of the Laplacian on symmetric spaces of rank greater than one and their geometric perturbations. Our goal here is to explain how analysis of the Laplacian on the globally symmetric space $\SL(3,\RR)/\SO(3,\RR)$ is very closely related to quantum three-body scattering. In particular, we adapt geometric constructions from recent advances in that field by one of us (A.V.), as well as from our previous work [Mazzeo-Vasy:Resolvents] concerning resolvents for product spaces, to give a precise description of the resolvent and the spherical functions on this space. Amongst the many technical advantages, these methods give results which are uniform up to the walls of the Weyl chambers.
Variance Calculations and the Bessel Kernel

In the Laguerre ensembleof n xN Hermitian matrices, it is of interest both theoretically and for applications to quantum transport problems to compute the variance of a linear statistic, denoted varN f, asN → ∞. Furthermore, this statistic often contains an additional parameter a for which the limit α → ∞ is most interesting and most difficult to compute numerically. We derive exact expressions for both limN → ∞ varN f and limα → ∞, limN → ∞ varN f.
Hydrocarbon conversion on palladium catalysts

Abstract The reaction pathways for acetylene trimerization and hydrogenation, and ethylene hydrogenation, catalyzed by palladium, are explored using a range of surface-sensitive techniques. Reflection–absorption infrared spectroscopy (RAIRS) and low-energy electron diffraction (LEED) show that ethylene is di-σ-bonded on clean Pd(1 1 1), but forms a π-bonded species on a hydrogen pre-covered surface, where the transformation is induced by sub-surface hydrogen. Catalytic ethylene hydrogenation proceeds on an ethylidyne-covered Pd(1 1 1) surface, and it is found that ethylene can still adsorb onto palladium in spite of the presence of an ethylidyne overlayer, and is still in a di-σ-configuration. The rates of ethylidyne formation, and removal by hydrogen are measured independently, where the latter rate is found to be first order in hydrogen pressure. The ethylidyne coverage is measured under reaction conditions as a function of P(H2)/P(C2H4) and found to decrease to ∼1/3 of saturation. Benzene is formed from acetylene on clean Pd(1 1 1) via a metallocyclic C4H4 intermediate. This further reacts with a third acetylene to form benzene. However, catalytic cyclotrimerization proceeds in the presence of a carbonaceous layer, which consists of vinylidene species (CH2 C ). Thus, at high pressures, benzene is formed by reaction between acetylene adsorbed on the vinylidene-covered palladium surface and adsorbed vinylidene itself. The addition of high pressures of hydrogen to the reaction mixture forms a more open surface covered by a mixture of ethylidyne and vinylidene species, rationalizing the observed increase in the benzene formation rate with the addition of hydrogen.
Fritz Machlup and behavioralism

This paper is concerned with Fritz Machlup's defense of neoclassical economics against organizational economics and the behavioral theory of the firm. Machlup's objections to organizational economics were narrowly semantic. Properly understood, however, Machlup's methodology has much to offer organizational theory. His position has been mistaken for a form of positivism and as equivalent to Milton Friedman's methodology. In fact, Machlup was a leading methodological subjectivist. Surprisingly, Machlup's version of neoclassical theory is complementary to organizational economics, including behavioralism. Copyright 2000 by Oxford University Press.
Computer analysis of side-band holography in STEM

Abstract The feasibility of a recently proposed method for direct reconstruction of a wave function at the exit plane of an object is tested on the basis of computer simulation. It is assumed that the point electron source of a STEM instrument is ideally coherent. Optimum imaging conditions for recording of a hologram are found with respect to a restoration error as a function of the desired spatial resolution of a restored wave function and the accelerating voltage. The highest spatial resolution that can be achieved for 100 and 300 kV holography is determined. The size of a region is determined for which the wave function can be restored for any one beam position. Accuracy requirements to which the experimental imaging conditions should be known are worked out.
Study of Epitaxial Graphene on Non-Polar 6H-SiC Faces

We present epitaxial graphene (EG) growth on non-polar a-plane and m-plane 6H-SiC faces where material characterization is compared with that known for EG grown on polar faces. AFM surface morphology exhibits nanocrystalline graphite like features for non-polar faces, while polar silicon face shows step like features. This differing behavior is attributed to the lack of a hexagonal template on the non-polar faces. Non-polar faces also exhibit greater disorder and red shift of all Raman peaks (D, G and 2D) with increasing temperature. This is attributed to decreasing stress with increasing temperature. These variations provide evidence of different EG growth mechanisms on non-polar and polar faces, likely due to differences in surface free energy. We also present differences between a-plane ( ) EG and m-plane ( ) EG in terms of morphology, thickness and Raman characteristics.
Determinants associated to zeta matrices of posets

We consider the matrix ZP=ZP+ZPt, where the entries of ZP are the values of the zeta function of the finite poset P. We give a combinatorial interpretation of the determinant of ZP and establish a recursive formula for this determinant in the case in which P is a boolean algebra.
Turbulent mixing in the outer solar nebula

The effects of turbulence on the mixing of gases and dust in the outer solar nebula are examined using three-dimensional MHD calculations in the shearing-box approximation with vertical stratification. The turbulence is driven by the magnetorotational instability. The magnetic and hydrodynamic stresses in the turbulence correspond to an accretion time at the midplane about equal to the lifetimes of T Tauri disks, while accretion in the surface layers is 30 times faster. The mixing resulting from the turbulence is also fastest in the surface layers. The mixing rate is similar to the rate of radial exchange of orbital angular momentum, so that the Schmidt number is near unity. The vertical spreading of a trace species is well matched by solutions of a damped wave equation when the flow is horizontally averaged. The damped wave description can be used to inexpensively treat mixing in one-dimensional chemical models. However, even in calculations reaching a statistical steady state, the concentration at any given time varies substantially over horizontal planes, due to fluctuations in the rate and direction of the transport. In addition to mixing species that are formed under widely varying conditions, the turbulence intermittently forces the nebula away from local chemical equilibrium. The different transport rates in the surface layers and interior may affect estimates of the grain evolution and molecular abundances during the formation of the solar system.
Tagged small molecule library approach for facilitated chemical genetics

Chemical genetics is a powerful method which utilizes small molecule regulators to reveal the molecular basis of diverse biological processes. However, the current chemical genetic approach sometimes meets a serious bottleneck during the process of target identification. One faces difficulty in conjugating the active compound to an affinity matrix without losing or reducing its activity that leads to laborious structure-activity relationship (SAR) studies. To facilitate this process, we have developed a tagged triazine library containing a built-in linker that provides a straightforward transition from phenotypic screening to target identification. A strategy for constructing a tagged library and applications with a streamlined target identification and subsequent mechanistic study are discussed in this Account.
Test of CZT detectors with different pixel pitches and thicknesses

The modified horizontal Bridgman (MHB) process produces cadmium zinc telluride (CZT) crystals with high yield and excellent homogeneity. Various groups, including our own, previously reported on the test of 2times2times0.5 cm3 MHB CZT detectors grown by the company Orbotech and read out with 8times8 pixels. In this contribution, we describe the optimization of the photolithographic process used for contacting the CZT detector with pixel contacts. The optimized process gives a high yield of good pixels down to pixel diameters/pitches of 50 microns. Furthermore, we discuss the performance of 0.5 cm and 0.75 cm thick detectors contacted with 64 and 225 pixel read out with the RENA-3 ASICs from the company NOVA R&D.
Performance analysis of multihop lightwave networks with hot potato routing and distance-age-priorities

Multihop lightwave networks with hot potato routing offer the potential for significantly higher aggregate capacity as compared against minimum distance routing since each interconnecting link can be operated at a rate much higher than the electro-optic constraint forced by store-and-forward buffering. If the links can be operated at a speed sufficiently high as to offset the hot potato misrouting inefficiency, then a net capacity gain will be enjoyed. In this paper, we study such a network in which contention for an outbound link is resolved by assigning to each packet a priority based on its distance to destination and its age (number of misroutes previously suffered). An approximate analysis based on a reasonable set of assumptions is presented, queueing delay, packet loss performance, and network aggregate capacity (saturation throughout) are compared for distance-age prioritization, age-distance prioritization, and no prioritization. Results suggest that the lowest delay, lowest packet loss performance, and highest saturation throughput are offered by distance-age prioritization (priority given first to a packet closest to its destination and second to the oldest of multiple packets of the same distance to destination). The tails of the probability distribution for the number of hops taken by a representative packet are, however, shorter for age-distance routing. The capacity gain with link speed-up and hot potato routing can be quite significant compared to link speed-constrained store and forward buffering, and grows with both link speed-up factor and network size. >
Smart societies: from citizens as sensors to collective action

Social media has become globally ubiquitous, transforming how people are networked and mobilized. This forum explores research and applications of these new networked publics at individual, organizational, and societal levels. Shelly Farnham, Editor
Synthesis of 1-Formyldipyrromethanes

1-Formyldipyrromethanes are versatile precursors to porphyrins and chlorins. Two methods of synthesis of 1-formyldipyrromethanes have been investigated: (1) Vilsmeier formylation followed by selective removal of the unwanted 1,9-diformyldipyrromethane by dialkyltin complexation and (2) reaction with mesitylmagnesium bromide (MesMgBr) followed by formylation with phenyl formate. The two approaches are complementary (acidic versus basic conditions; statistical versus selective formylation). The latter was found to be more efficient for the preparation of 1-formyldipyrromethanes.
Super-resolution off the grid

Super-resolution is the problem of recovering a superposition of point sources using bandlimited measurements, which may be corrupted with noise. This signal processing problem arises in numerous imaging problems, ranging from astronomy to biology to spectroscopy, where it is common to take (coarse) Fourier measurements of an object. Of particular interest is in obtaining estimation procedures which are robust to noise, with the following desirable statistical and computational properties: we seek to use coarse Fourier measurements (bounded by some cutoff frequency); we hope to take a (quantifiably) small number of measurements; we desire our algorithm to run quickly. Suppose we have k point sources in d dimensions, where the points are separated by at least Δ from each other (in Euclidean distance). This work provides an algorithm with the following favorable guarantees: • The algorithm uses Fourier measurements, whose frequencies are bounded by O(1/Δ) (up to log factors). Previous algorithms require a cutoff frequency which may be as large as Ω(√d/Δ). • The number of measurements taken by and the computational complexity of our algorithm are bounded by a polynomial in both the number of points k and the dimension d, with no dependence on the separation Δ. In contrast, previous algorithms depended inverse polynomially on the minimal separation and exponentially on the dimension for both of these quantities. Our estimation procedure itself is simple: we take random bandlimited measurements (as opposed to taking an exponential number of measurements on the hyper-grid). Furthermore, our analysis and algorithm are elementary (based on concentration bounds for sampling and the singular value decomposition).
Efficient protection and grooming architectures for future optical networks

Today networks are too cumbersome due to the incoherent integration of various technologies developed over time. Convergence of data, voice, and video has caused the retro-fitting of a network to support non-native traffic types and this has led to sub-par performance for every traffic type. Fundamental changes are warranted to support high bandwidth traffic. The network must guarantee end-to-end delivery and provide inherent protection within the physical structure. We propose that the main traffic types of today's applications should be carried using the following features: connection-oriented service, traffic grooming to fill those connection oriented pipes, and forward error recovery with protection provided in the physical layer. We present some of our research results.
Magnetic Monopoles, Fiber Bundles, and Gauge Fields

The reports in this monograph have shown great enthusiasm and exuberance for the unification of various interactions through the concept of gauge fields. I would like to emphasize a point that has not yet been explicitly stated by any of the other authors: gauge fields are deeply related to some profoundly beautiful ideas of contemporary mathematics, ideas that are the driving forces of part of the mathematics of the last 40 years. Recalling the relationship between physics and mathematics in earlier periods, general relativity and Riemannian geometry, quantum mechanics and Hilbert space, it is all too obvious that physicists may again be zeroing in on a fundamental new secret of nature.
Anyon Condensation and Continuous Topological Phase Transitions in Non-Abelian Fractional Quantum Hall States

We find a series of possible continuous quantum phase transitions between fractional quantum Hall states at the same filling fraction in two-component quantum Hall systems. These can be driven by tuning the interlayer tunneling and/or interlayer repulsion. One side of the transition is the Halperin $(p,p,p\ensuremath{-}3)$ Abelian two-component state, while the other side is the non-Abelian ${Z}_{4}$ parafermion (Read-Rezayi) state. We predict that the transition is a continuous transition in the 3D Ising class. The critical point is described by a ${Z}_{2}$ gauged Ginzburg-Landau theory. These results have implications for experiments on two-component systems at $\ensuremath{\nu}=2/3$ and single-component systems at $\ensuremath{\nu}=8/3$.
Copolymerization of CO2 and epoxides catalyzed by metal salen complexes.

The design of efficient metal catalysts for the selective coupling of epoxides and carbon dioxide to afford completely alternating copolymers has made significant gains over the past decade. Hence, it is becoming increasingly clear that this “greener” route to polycarbonates has the potential to supplement or supplant current processes for the production of these important thermoplastics, which involve the condensation polymerization of diols and phosgene or organic carbonates. On the basis of the experiences in our laboratory, this Account summarizes our efforts at optimizing (salen)CrIIIX catalysts for the selective formation of polycarbonates from alicyclic and aliphatic epoxides with CO2. An iterative catalyst design process is employed in which the salen ligand, initiator, cocatalyst, and reaction conditions are systematically varied, with the reaction rates and product selectivity being monitored by in situ infrared spectroscopy.
LOOP MODELS, MARGINALLY ROUGH INTERFACES, AND THE COULOMB GAS

We develop a coarse-graining procedure for two-dimensional models of fluctuating loops by mapping them to interface models. The result is an effective field theory for the scaling limit of loop models, which is found to be a Liouville theory with imaginary couplings. This field theory is completely specified by geometry and conformal invariance alone, and it leads to exact results for the critical exponents and the conformal charge of loop models. A physical interpretation of the Dotsenko-Fateev screening charge is found.
Failure Analysis of a Beam-Column Under Oblique-Eccentric Loading: Potential Failure Surfaces for Cervical Spine Trauma

For a cantilever beam-column with one end built-in and the free end subjected to an oblique-eccentric arbitrary concentrated force, general formulas to produce failure were derived. The original generalized uniform solution to the oblique-eccentric buckling problem was obtained. The Secant formula and Euler's formula were proved to be specific cases in this general solution. The load ratio, F/aE, was derived as functions of the force acting direction, alpha, the slenderness ratio, L/r, as well as the eccentricity ratio, ec/r2. Material and buckling failures aspects were combined in a uniform structural failure analysis. Safe regions for the load ratio, F/aE, were visualized in the three-dimensional (F/aE)-alpha-(L/r) space with the eccentricity ratios, ec/r2, as a parameter. The column failure factor, kL, was shown to be a key index controlling both aspects of failure as well as the orientation of the second stiffest region. The angle alpha E = tan-1 (2L/pi e) for kL = pi/2 is the singular point for both strength and buckling failure, and alpha II = tan-1 (2L/3e) for KL = 0 is the upper bound of the second stiffest region. The feasible domain of the second stiffest region is bounded by alpha E and alpha II both of which are only functions of geometrical properties. The implications of these analyses for the experimental validation of cervical spine trauma are discussed.
The not-so-absent-minded driver

Abstract This paper starts with a re-examination of Piccione and Rubinstein's [Games Econ. Behav. 20 (1997) 3] Absent-Minded Driver problem, and suggests a novel interpretation of Aumann, Hart and Perry's [Games Econ. Behav. 20 (1997) 102] notion of action-optimality. We then consider several variants of the original problem in which the assumption that the player's information sets partition the set of his decision nodes is relaxed. This relaxation enables us to construct a counter-example to Piccione and Rubinstein's result that planning-optimal strategies are always action-optimal. We also show that an agent with more information may do worse than an agent with less.
Low loss polymer waveguides fabricated by plasma etching for nonlinear-optical devices operating at telecommunication wavelengths

Summary form only given. Organic materials exhibit large optical nonlinearities and, hence, are attractive for parametric interactions, cascading, and wavelength demultiplexing. In poled polymer waveguides figures of merit comparable to inorganic materials were obtained for second-harmonic generation (SHG) at 1.55 /spl mu/m. However, the absolute conversion efficiency was limited by the high loss of several tens of dB cm/sup -1/ at the second-harmonic wavelength. To reduce the loss of polymer waveguides used for second-order nonlinear effects at telecommunication wavelengths, materials with low intrinsic absorption between 0.6 and 1.6 /spl mu/m have to be combined with techniques allowing one to form waveguides with low scattering losses. Measurements are presented which show that with suitable materials, fabrication processes (plasma etching), and guide geometries it is possible to produce improved nonlinear polymer waveguides with sufficiently low losses for parametric mixing and cascading at 1.3 and 1.5 /spl mu/m.
Enhanced geographically typed semantic schema matching

Resolving semantic heterogeneity across distinct data sources remains a highly relevant problem in the GIS domain requiring innovative solutions. Our approach, called GSim, semantically aligns tables from respective GIS databases by first choosing attributes for comparison. We then examine their instances and calculate a similarity value between them called entropy-based distribution (EBD) by combining two separate methods. Our primary method discerns the geographic types from instances of compared attributes. If successful, EBD is calculated using only this method. GSim further facilitates geographic type matching by using latlong values to further disambiguate between multiple types of a given instance and applying attribute weighting to quantify the uniqueness of mapped attributes. If geographic type matching is not possible, we then apply a generic schema matching method, independent of the knowledge domain, which employs normalized Google distance. We show the effectiveness of our approach over the traditional approaches across multi-jurisdictional datasets by generating impressive results.
Dependency of supershear transition and ground motion on the autocorrelation of initial stress

Abstract Theoretical and observational studies show that earthquakes on strike–slip faults can have rupture speeds exceeding the shear wave speed. Due to the close relationship between the rupture velocity and the radiated wave field, it is important to understand the conditions leading to supershear ruptures and their effect on the resulting ground motion. We compute dynamic strike slip ruptures in a 3D elastic half space using heterogeneous frictional properties on faults that are 60 km long. We use a grid spacing of 60 m allowing us to compute ground motion for frequencies from 0 to 5 Hz. We analyze the resulting ground motion using isochrones to explain phenomena we observe. We model the amplitudes of the initial shear stress as a self-similar random field with Cauchy distributed amplitudes. The wavenumber amplitude spectrum of initial stress decays as a power law with exponent ν that controls the decay and the spatial correlation of the initial stress. The faster the decay (corresponding to larger value of ν ), the more correlated is the stress on the fault, i.e., the stress field appears spatially smoother. The strength on the fault is computed under the assumption of a constant S -factor, where S is the ratio of strength excess over stress drop. On a fault with uniform strength and stress drop the S -factor has to be less than a critical value for the supershear transition to occur. For models with heterogeneous initial stress we find that both the S -factor and the value of the spectral decay constant ν affect the occurrence of supershear rupture. We observe that for a given, but small enough, S -factor a smooth model ( ν ≥ 2) can run at supershear speed while a rough model ( ν ∼ 1) will rupture at subshear speeds for the same S -factor. Based on the theory of fracture, a non-dimensional number κ was introduced to quantify the condition when a transition to supershear rupture velocity can occur during an earthquake. Transition will occur when κ exceeds a critical value. We introduce a modified dimensionless parameter κ ac that is based on the original parameter κ . The parameter κ ac incorporates a length scale W ac that reflects the degree of the autocorrelation of the stress field. We compute κ ac for a large number of available dynamic ruptures that propagate at subshear and supershear speeds and find: i) there is a critical value κ ac ( c ) below which all ruptures propagate subshear; ii) for values larger than κ ac ( c ) there is only a finite probability that the rupture goes supershear, i.e. it is a necessary but not a sufficient condition for the occurrence of supershear rupture propagation.
Matched subspace detectors

We formulate a general class of problems for detecting subspace signals in subspace interference and broadband noise. We derive the generalized likelihood ratio (GLR) for each problem in the class. We then establish the invariances for the GLR and argue that these are the natural invariances for the problem. In each case, the GLR is a maximal invariant statistic, and the distribution of the maximal invariant statistic is monotone. This means that the GLR test (GLRT) is the uniformly most powerful invariant detector. We illustrate the utility of this finding by solving a number of problems for detecting subspace signals in subspace interference and broadband noise. In each case we give the distribution for the detector and compute performance curves. >
A Markov random field approach to Bayesian speaker adaptation

Speaker adaptation through Bayesian learning methodology is studied in this paper. In order to utilize the cross allophone correlations, a Markov random field (MRF) model is proposed as the joint prior distribution of the mean vectors of the allophones. Neighborhoods are defined as pairs of parameters between which strong correlations have been observed previously. Maximum a posteriori estimates of the mean vectors are obtained through an iterative optimization technique that converges to the global maximum of the posterior distribution. This process is similar to a recursive prediction of the parameters, where at each iteration each parameter is estimated by a weighted sum of two terms, the first predicted by the neighbors and the second by the samples. Further Bayesian smoothing of the output distributions is carried out by utilizing some simplifications on the functional forms of the marginal posterior distributions. The proposed method is fast, consuming only a few CPU minutes for processing hundreds of sentences from a new speaker on an IBM RS6000 Model 580 system. Experimental results show rapid improvement of recognition accuracy.
Bialgebra actions, twists, and universal deformation formulas

Abstract We use the concept of gauge transformations of quasi-Hopf algebras to study twists of algebraic structures based on actions of a bialgebra and relate this to the theory of universal deformation formulas. We establish new universal deformation formulas which are associated to central extensions of Heisenberg Lie algebras. These formulas are generalizations of the Moyal quantization formula.
A fast algorithm for 3D azimuthally anisotropic velocity scan

The conventional velocity scan can be computationally expensive for large-scale seismic data sets, particularly when the presence of anisotropy requires multiparameter scanning. We introduce a fast algorithm for 3D azimuthally anisotropic velocity scan by generalizing the previously proposed 2D butterfly algorithm for hyperbolic Radon transforms. To compute semblance in a two-parameter residual moveout domain, the numerical complexity of our algorithm is roughly O(N 3 log N) as opposed to O(N 5 ) of the straightforward velocity scan, with N being the representative of the number of points in a particular dimension of either data space or parameter space. Synthetic and field data examples demonstrate the superior efficiency of the proposed algorithm.
Communicating Over Adversarial Quantum Channels Using Quantum List Codes

In this correspondence, we study quantum communication in the presence of adversarial noise. In this setting, communicating with perfect fidelity requires a quantum code of bounded minimum distance, for which the best known rates are given by the quantum Gilbert-Varshamov (QGV) bound. Asking only for arbitrarily high fidelity and letting the sender and receiver use a secret key of length logarithmic in the number of qubits sent, we find a dramatic improvement over the QGV rates. In fact, our protocols allow high fidelity transmission at noise levels for which perfect fidelity is impossible. To achieve such rates, we introduce fully quantum list codes, which may be of independent interest.
A Simple Proof of Bazzi’s Theorem

Linial and Nisan [1990] asked if any polylog-wise independent distribution fools any function in AC0. In a recent remarkable development, Bazzi solved this problem for the case of DNF formulas. The aim of this note is to present a simplified version of his proof.
Relationships of linguistic and motivation variables with drinking outcomes following two mailed brief interventions

Objective: This study was a post hoc analysis of linguistic and motivation variables found in writing samples following the administration of two mailed brief interventions. Method: At-risk college drinkers (N = 100) received personalized normative feedback (PNF) or an alcohol education (AE) brochure via mail. Participants responded to open-ended questions describing their reactions to the information they received. The writing samples were then coded for linguistic characteristics using the Linguistic Inquiry and Word Count program and for proportions of self-motivational statements using a modified version of the Motivational Interviewing Skills Code. Results: Group comparisons indicated that the PNF group used a significantly higher percentage of first-person-singular and school-related words, whereas the AE group used a higher percentage of discrepancy, second-person and body-related words. Furthermore, the PNF group produced more language consistent with motivation to change than did the AE group. Hi...
Fluorescent core–shell silica nanoparticles: towards “Lab on a Particle” architectures for nanobiotechnology

Novel nanoscale fluorescent materials are integral to the progress of emergent fields such as nanobiotechnology and facilitate new research in a variety of contexts. Sol–gel derived silica is an excellent host material for creating fluorescent nanoparticles by the inclusion of covalently-bound organic dyes. Significant enhancements in the brightness and stability of organic dye emission can be achieved for silica-based core–shell nanoparticle architectures at length scales down to tens of nanometers with narrow size distributions. This tutorial review will highlight these findings and describe the evolution of the fluorescent core–shell silica nanoparticle concept towards integration of multiple functionalities including mesoporosity, metal nanoshells and quantitative chemical sensing. These developments point towards the development of “lab on a particle” architectures with promising prospects for nanobiotechnology, drug development and beyond.
Water‐Accelerated Claisen Rearrangements

Allyl aryl ethers undergo accelerated Claisen and [1,3] rearrangements in the presence of a mixture of trialkylalanes and water or aluminoxanes. The ratio of ortho-, meta-, and para-Claisen products depends to a large extent on the presence of water and to a much lesser extent on the nature of the alane.
Dendrimers with tetrabenzoporphyrin cores: near infrared phosphors for in vivo oxygen imaging

Abstract Pd complexes of tetrabenzoporphyrins (PdTBPs) are strong near infra-red phosphors, suitable for tissue oxygen imaging by phosphorescence quenching. For in vivo use, PdTBP phosphors have to be water-soluble and protected from interactions with biomacromolecules in the blood. An approach to the construction of biologically compatible PdTBP-phosphors based on dendritic encapsulation is proposed. A series of polyglutamic PdTBP-dendrimers was synthesized and their optical and quenching properties were studied. While retaining the excellent optical characteristics (λmax Q=630 nm, φphos=12%) of basic PdTBPs and in addition being highly water soluble, PdTBP-dendrimers still exhibit excessively high oxygen quenching constants (2000–3000 mmHg−1 s−1) and form complexes with lipophilic proteins, such as serum albumin. Modification of the dendrimer periphery with polyethyleneglycol chains somewhat reduces the quenching constants but does not prevent binding of the phosphors to albumin.
Adaptive stabilization of linear systems via switching control

In this paper, we develop a method for adaptive stabilization without a minimum-phase assumption and without knowledge of the sign of the high-frequency gain. In contrast to recent work by Martensson [8], we include a compactness requirement on the set of possible plants and assume that an upper bound on the order of the plant is known. Under these additional hypotheses, we generate a piecewise linear time-invariant switching control law which leads to a guarantee of Lyapunov stability and an exponential rate of convergence for the state. One of the main objectives in this paper is to eliminate the possibility of "large state deviations" associated with a search Over the space of gain matrices which is required in [8].
A Tin-Complexation Strategy for Use with Diverse Acylation Methods in the Preparation of 1,9-Diacyldipyrromethanes

The acylation of dipyrromethanes to form 1,9-diacyldipyrromethanes is an essential step in the rational synthesis of porphyrins. Although several methods for acylation are available, purification is difficult because 1,9-diacyldipyrromethanes typically streak extensively upon chromatography and give amorphous powders upon attempted crystallization. A solution to this problem has been achieved by reacting the 1,9-diacyldipyrromethane with Bu2SnCl2 to give the corresponding dibutyl(5,10-dihydrodipyrrinato)tin(IV) complex. The reaction is selective for dipyrromethanes that bear acyl groups at both the 1- and 9-positions but otherwise is quite tolerant of diverse substituents. The diacyldipyrromethane−tin complexes are stable to air and water, are highly soluble in common organic solvents, crystallize readily, and chromatograph without streaking. Four methods (Friedel−Crafts, Grignard, Vilsmeier, benzoxathiolium salt) were examined for the direct 1,9-diacylation of a dipyrromethane or the 9-acylation of a 1-a...
Acquiring a Lexicon from Unsegmented Speech

We present work-in-progress on the machine acquisition of a lexicon from sentences that are each an unsegmented phone sequence paired with a primitive representation of meaning. A simple exploratory algorithm is described, along with the direction of current work and a discussion of the relevance of the problem for child language acquisition and computer speech recognition.
Dietary phytoestrogens and lung cancer risk.

ContextDespite lung-specific in vitro and in vivo studies that support a chemopreventive role for phytoestrogens, there has been little epidemiologic research focused on dietary intake of phytoestrogens and risk of lung cancer.ObjectiveTo examine the relationship between dietary intake of phytoestrogens and risk of lung cancer.Design, Setting, and ParticipantsOngoing US case-control study of 1674 patients with lung cancer (cases) and 1735 matched healthy controls. From July 1995 through October 2003, participants were personally interviewed with epidemiologic and food frequency questionnaires to collect demographic information and to quantify dietary intake of 12 individual phytoestrogens.Main Outcome MeasureRisk of lung cancer, estimated using unconditional multivariable logistic regression analyses stratified by sex and smoking status and adjusted for established and putative lung cancer risk factors.ResultsReductions in risk of lung cancer tended to increase with each increasing quartile of phytoestrogen intake. The highest quartiles of total phytosterols, isoflavones, lignans, and phytoestrogens were each associated with reductions in risk of lung cancer ranging from 21% for phytosterols (odds ratio [OR], 0.79; 95% confidence interval [CI], 0.64-0.97; P = .03 for trend) to 46% for total phytoestrogens from food sources only (OR, 0.54; 95% CI, 0.42-0.70; P<.001 for trend). Sex-specific effects were also apparent. For men, statistically significant trends for decreasing risk with increasing intake were noted for each phytoestrogen group, with protective effects for the highest quartile of intake ranging from 24% for phytosterols (OR, 0.76; 95% CI, 0.56-1.02; P = .04 for trend) to 44% for isoflavones (OR, 0.56; 95% CI, 0.41-0.76; P<.001 for trend), while in women, significant trends were only present for intake of total phytoestrogens from food sources only, with a 34% (OR, 0.66; 95% CI, 0.46-0.96; P = .01 for trend) protective effect for the highest quartile of intake. The apparent benefits of high phytoestrogen intake were evident in both never and current smokers but less apparent in former smokers. In women, statistically significant joint effects were evident between hormone therapy use and phytoestrogen intake. Specifically, high intake of the lignans enterolactone and enterodiol and use of hormone therapy were associated with a 50% (OR, 0.50; 95% CI, 0.31-0.68; P = .04 for interaction) reduction in risk of lung cancer.ConclusionsWhile there are limitations and concerns regarding case-control studies of diet and cancer, these data provide further support for the limited but growing epidemiologic evidence that phytoestrogens are associated with a decrease in risk of lung cancer. Confirmation of these findings is still required in large-scale, hypothesis-driven, prospective studies.
Free Agency and the Concentration of Player Talent in Major League Baseball

This article investigates whether the removal of the reserve clause in professional baseball affected the concentration of player talent in the industry. After free agency, a few wealthy teams could purchase the best players over time, leading to a high concentration of productive players and adversely affecting the competitive nature of the industry. To investigate his possibility, the Herfindahl-Hirschman Index, and the deviation of the index from its ideal, for home runs, strike outs and runs scored is related to structural changes in professional baseball. Free agency reduced the concentration of home runs but not of strike outs or runs scored. These findings are consistent with increased player mobility but not with monopolization by a minority of teams.
Moral Psychology and the Intuition that Pharmaceutical Companies Have a ‘Special’ Obligation to Society

Many people believe that the research-based pharmaceutical industry has a ‘special’ moral obligation to provide lifesaving medications to the needy, either free-of-charge or at a reduced rate relative to the cost of manufacture. In this essay, I argue that we can explain the ubiquitous notion of a special moral obligation as an expression of emotionally charged intuitions involving sacred or protected values and an aversive response to betrayal in an asymmetric trust relationship. I then review the most common arguments used to justify the claim that the pharmaceutical industry has a special moral obligation and show why these justifications fail. Taken together, these conclusions call into question the conventional ideologies that have traditionally animated the debate on whether the pharmaceutical industry has special duties of beneficence and distributive justice with respect to the impoverished in dire need of their products.
Leveraging entrepreneurship through private investments: Does gender matter?

Using project data from a random sample of Phase II research awards from the National Institutes of Health SBIR program, we estimate the relative probability that woman-owned firms are able to attract private investments to fund the transition of the technology developed under the sponsorship of the SBIR program to an innovation to enter the market. We find that women-owned firms are as much as 16% points less likely to attract private investment dollars compared to male-owned firms, factors excluding the size of the SBIR award held constant. Women-owned firms that received larger awards performed substantially better. Although the SBIR program has a legislated directive to increase the participation of woman-owned firms in the program, our findings suggest that it might not be sufficient to overcome market perceptions about the profitability of such investments actually bringing a developed technology to market.