cssi/SciSciGPT-SciSciNet huggingface dataset:
Power normalized update algorithm for adaptive filters-without divisions

Two power-normalized update algorithms for adaptive filters are described that do not require divisions. The algorithms are based on very simple iterative procedures that approximate divisions. Since neither the quotients nor the dividends change quickly, the division procedures need only be updated once each time the coefficients of the adaptive filter are updated. One algorithm requires three extra multiplications per coefficient and results in adaptive filters with convergence times practically identical to those achieved when actual divisions are used. The second algorithm requires only one multiplication per coefficient instead of a division, yet results in adaptive filter convergence times only slightly larger than those obtained with real divisions. Both algorithms result in adaptive filters only slightly more complex than steepest descent adaptive filters. The algorithms are especially applicable to real-time adaptive filters realized using single-chip digital signal processors or custom ASICs where hard-wired dividers are usually not available and fast convergence is still desired. >
Some non-trivial PL knots whose complements are homotopy circles

We show that there exist non-trivial piecewise-linear (PL) knots with isolated singularities S ni2 ‰ S n , n ‚ 5, whose complements have the homotopy type of a circle. This is in contrast to the case of smooth, PL locally-∞at, and topological locally-∞at knots, for which it is known that if the complement has the homotopy type of a circle, then the knot is trivial.
Fabrication of Free‐Standing Titania‐Based Gas Sensors by the Oxidation of Metallic Titanium Foils

A simple method for fabricating TiO2-based sensors of CO(g) is demonstrated: the oxidation of Ti-bearing foils. Metallic foils (35 μm thick) were converted into free-standing, porous rutile foils (60 μm thick) by exposure to O2(g) at 800°—965°C. The oxidized foils contained thin (0.5—1 μm thick), regularly spaced oxide layers oriented parallel to the external surface. The exposure of such porous foils to increasing concentrations of CO(g) resulted in a monotonic increase in the steady-state electrical resistance. Rutile foils sensitive to 50 ppm changes in CO(g) content with response times of a few minutes were produced. The effects of oxidation conditions and copper doping on sensing performance are discussed.
Ultrafast Imaging and the Phase Problem for Inelastic X-Ray Scattering

A new method for imaging ultrafast dynamics in condensed matter using inelastic X-ray scattering (IXS) is described. Using the concepts of causality and irreversibility a general solution to the inverse scattering problem (or "phase problem") for IXS is illustrated, which enables direct imaging of dynamics of the electron density with resolutions of approximately 1 attosecond (10(-18) s) in time and <1 A in space. This method is not just Fourier transformation of the IXS data, but a means to impose causality on the data and reconstruct the charge propagator. The method can also be applied to inelastic electron or neutron scattering. A general outline of phenomena that can and cannot be studied with this technique and an outlook for the future is provided.
Defence expenditures and economic growth: The externality effect

In a series of articles published in the Fall 1990 issue of Defence Economics Alexander (1990), Atesoglu and Mueller (1990) and Huang and Mintz (1990) have all specified and empirically estimated d...
QUARK COUNTING RULES: OLD AND NEW APPROACHES

I discuss the subject of powerlike asymptotic behavior of hadronic form factors in pre-QCD analyses of soft (Feynman/Drell-Yan) and hard (West) mechanisms, and also recent derivation of 1/Q2 asymptotics of meson form factors in AdS/QCD. At the end, I briefly comment on "light-front holography" ansatz.
Polynomial Hierarchy, Betti Numbers, and a Real Analogue of Toda’s Theorem

Toda (in SIAM J. Comput. 20(5):865–877, 1991) proved in 1989 that the (discrete) polynomial time hierarchy, PH, is contained in the class P #P , namely the class of languages that can be decided by a Turing machine in polynomial time given access to an oracle with the power to compute a function in the counting complexity class #P. This result, which illustrates the power of counting, is considered to be a seminal result in computational complexity theory. An analogous result in the complexity theory over the reals (in the sense of Blum–Shub–Smale real machines in Bull. Am. Math. Soc. (NS) 21(1): 1–46, 1989) has been missing so far. In this paper we formulate and prove a real analogue of Toda’s theorem. Unlike Toda’s proof in the discrete case, which relied on sophisticated combinatorial arguments, our proof is topological in nature. As a consequence of our techniques, we are also able to relate the computational hardness of two extremely well-studied problems in algorithmic semi-algebraic geometry: the problem of deciding sentences in the first-order theory of the reals with a constant number of quantifier alternations, and that of computing Betti numbers of semi-algebraic sets. We obtain a polynomial time reduction of the compact version of the first problem to the second. This latter result may be of independent interest to researchers in algorithmic semi-algebraic geometry.
PEMFC Contamination Model: Competitive Adsorption Followed by an Electrochemical Reaction

A transient, generic contamination model addressing kinetic losses in proton exchange membrane fuel cells (PEMFCs) with closed-form solutions is presented. The model is applicable to both the cathode (oxygen reduction reaction) and anode (hydrogen oxidation reaction), because the reactant rate-determining step (rds) in each case is similar and involves an intermediate adsorbate species. The contaminant rds is either a reaction or desorption of an adsorbed product. The model is validated using both fuel cell and sensor operation data for a range of designs (catalysts including Pt and WC) and operating conditions (CO, SO 2 , NO/NO 2 , and H 2 S introduced in the cathode or anode compartment). Model validation indicates the need for defined experimental procedures, including use of a controlled potential, design of setups avoiding contaminant residence time delays in pipes, data recording with sufficient resolution and over long periods to capture steady states, and duplicate experiments to evaluate reproducibility. Model validation also indicates that the contaminant reaction appears to be the prevalent rds. An approach to unambiguously obtain rate constants is proposed requiring sequential tests performed with a reactant, a contaminant, and a reactant/contaminant mixture.
CARBON CREDIT POTENTIAL FROM INTENSIVE ROTATIONAL GRAZING UNDER CARBON CREDIT CERTIFICATION PROTOCOLS

Rotational grazing can potentially reduce greenhouse gas (GHG) emissions from animal operations. This study investigates potential GHG reductions from rotational grazing farm operations under alternative procedures for defining a carbon credit. As applied to a case study cow-calf operation, GHG emission credits did not differ substantially under different definitions of entity boundaries. The choice of accounting metric used to report credits (mass load versus load per unit of output), however, would dramatically influence whether a farm would benefit financially from a future market in carbon credits.
A novel interband-resonant tunneling diode (I-RTD) based high-frequency oscillator ☆

Abstract A comprehensive study of the transport dynamics associated with electron- and hole-charge residing within a type-II AlGaSb/InAs/InGaSb double-barrier heterostructure is presented. These studies demonstrate an intrinsic instability within this type of resonant tunneling diode (RTD) that is initiated by an interband tunneling process. This novel interband-RTD (I-RTD), based upon staggered-bandgap heterostructures, is shown to offer a completely new avenue for the realization of very high-frequency sources. Specifically, this I-RTD device is shown to admit hole generation and discharging processes leading to repetitive cycles in electron current that constitute steady-state oscillatory behavior. Initial studies of non-optimized structures predict impressive figures of merit for oscillation frequencies (e.g., ∼300 GHz) and output powers (e.g., >2 mW) and suggest that the I-RTD is a promising new device for implementation as a terahertz (THz) frequency oscillator. Furthermore, these studies suggest that strategic engineering of the interband tunneling and charge accumulation processes may allow for significant latitude in controlling the performance of this oscillator concept at very high-frequencies.
Incremental Condition Estimator for Parallel Sparse Matrix Factorization

There is often a trade-off between preserving sparsity and numerical stability in sparse matrix factorizations. In applications like the direct solution of Equality Constrained Least Squares problem, the accurate detection of the rank of a large and sparse constraint matrix is a key issue. Column pivoting is not suitable for distributed memory machines because it forces the program into a lock-step mode, preventing any overlapping of computations. So factorization algorithms on such machines need to use a reliable, yet inexpensive incremental condition estimator to decide on which columns to be included. We describe an incremental condition estimator that can be used during a sparse QR factorization. We show that it is quite reliable and is well suited for use on parallel machines. We supply experimental results to support its effectiveness as well as suitability for parallel architectures.
Increased tropical Atlantic wind shear in model projections of global warming

[1] To help understand possible impacts of anthropogenic greenhouse warming on hurricane activity, we assess model-projected changes in large-scale environmental factors tied to variations in hurricane statistics. This study focuses on vertical wind shear (Vs) over the tropical Atlantic during hurricane season, the increase of which has been historically associated with diminished hurricane activity and intensity. A suite of state-of-the-art global climate model experiments is used to project changes in Vs over the 21st century. Substantial increases in tropical Atlantic and East Pacific shear are robust features of these experiments, and are shown to be connected to the model-projected decrease in the Pacific Walker circulation. The relative changes in shear are found to be comparable to those of other large-scale environmental parameters associated with Atlantic hurricane activity. The influence of these Vs changes should be incorporated into projections of long-term hurricane activity.
Feasibility of detecting single atoms using photonic bandgap cavities

We propose an atom–cavity chip that combines laser cooling and trapping of neutral atoms with magnetic microtraps and waveguides to deliver a cold atom to the mode of a fibre taper coupled photonic bandgap (PBG) cavity. The feasibility of this device for detecting single atoms is analysed using both a semiclassical treatment and an unconditional master equation approach. Single-atom detection seems achievable in an initial experiment involving the non-deterministic delivery of weakly trapped atoms into the mode of the PBG cavity.
Personal Information, Borders, and the New Surveillance Studies

This article reviews and critiques recent scholarship on surveillance and communication technology that involves the crossing of personal information borders. A Sociology of Information framework focusing on the normative elements is proposed as a way to integrate this variegated field. Empirical analysis is particularly needed to test the claims of surveillance scholars, and we suggest some hypotheses. The article concludes with a consideration of conflicting values and empirical trends that make this such a challenging field and suggests some “moral mandates” to guide research in the crossing of personal informational borders, whether this involves individual privacy and accountability or broader social concerns.
Climatic Forecasting of Net Infiltration at Yucca Mountain Using Analogue Meteorological Data

Net infiltration is a key hydrologic parameter that controls the rate of deep percolation through the unsaturated zone, the groundwater recharge, radionuclide transport, and seepage into the underground tunnels. Because net infiltration is largely affected by climatic conditions, future changes in climatic conditions will potentially alter net infiltration. The objectives of this presentation are to: (1) Present a conceptual model and a semi-empirical approach for regional, climatic forecasting of net infiltration, based on the precipitation and temperature data from analogue meteorological stations, and (2) Demonstrate the results of forecasting net infiltration for future climates--interglacial, monsoon and glacial--over the Yucca Mountain region for the period of 500,000 years. Calculations of the net infiltration were performed using a modified Budyko's water-balance model, for which potential evapotranspiration was evaluated from the temperature-based Thornthwaite formula. (Both Budyko's and Thornthwaite's formulae have been used broadly in hydrological studies.) The results of calculations were used for ranking net infiltration, along with the aridity and precipitation-effectiveness (P-E) indexes, for future climatic scenarios. Using this approach, we determined a general trend of increasing net infiltration from the present-day (interglacial) climate to monsoon, intermediate (glacial transition), and then to the glacial climate. Ranking of the aridity and P-E indexesmore » is practically the same as that of net infiltration. The validation of the computed net infiltration rates yielded a good match with other field and modeling study results of groundwater recharge and net infiltration evaluation.« less
Supply chain performance assessment and supplier and component importance identification in a general competitive multitiered supply chain network model

In this paper, we develop a multitiered competitive supply chain network game theory model, which includes the supplier tier. The firms are differentiated by brands and can produce their own components, as reflected by their capacities, and/or obtain components from one or more suppliers, who also are capacitated. The firms compete in a Cournot---Nash fashion, whereas the suppliers compete a la Bertrand since firms are sensitive to prices. All decision-makers seek to maximize their profits with consumers reflecting their preferences through the demand price functions associated with the demand markets for the firms' products. We construct supply chain network performance measures for the full supply chain and the individual firm levels that assess the efficiency of the supply chain or firm, respectively, and also allow for the identification and ranking of the importance of suppliers as well as the components of suppliers with respect to the full supply chain or individual firm. The framework is illustrated through a series of numerical supply chain network examples.
Are Private Defensive Expenditures against Storm Damages Affected by Public Programs and Natural Barriers? Evidence from the Coastal Areas of Bangladesh

This paper introduces a household model of private investment in storm protection under an endogenous risk framework to determine how ex-ante self-protection and ex-post self-insurance spending by coastal households to mitigate storm-inflicted damages are affected by the availability of public programs and the presence of a mangrove forest. The theoretical results show that ex-ante publicly constructed physical barriers and mangroves are complements to self-protection but substitutes to self-insurance. However, ex-post public disaster relief and rehabilitation programs are substitutes to self-protection but complements to self-insurance. Our empirical analysis of coastal households in Bangladesh impacted by Cyclone Sidr reveals partial support for crowding out and crowding in effects of public investments and programs. Households located in a mangrove protected area invest more in self-protection and less in self-insurance. Other controls, such as household socioeconomic characteristics, also influence and add a degree of complexity to the relationship.
Estimates of ad valorem equivalents of barriers against foreign suppliers of services in eleven services sectors and 103 countries

A new database on the barriers faced by foreign suppliers of services has been produced by the World Bank. Data for 103 countries are available on 11 of the most important services sectors in international trade. Based on these data and building on the methodology and publications supported by the Australian Productivity Commission, this paper produces estimates of the ad valorem equivalents of the barriers for all these sectors and countries. Compared with estimates available in the literature that are based on assessments of country- and sector-specific barriers to services providers, the estimates expand the set of sectors and more than triple the set of countries for which estimates of the ad valorem equivalents of the services barriers are available.
Resolution, Enantiomerization Kinetics, and Chiroptical Properties of 7,7‘-Dihydroxy-8,8‘-biquinolyl

(±)-7,7‘-Dihydroxy-8,8‘-biquinolyl (6) was resolved into its enantiomorphic atropisomers via reverse phase (C18) chromatographic separation of epimeric bismenthyl carbonates, (−)-lk-9 and (+)-ul-9, derived from 6 and (+)-menthyl chloroformate. The faster eluting diastereoisomer, (−)-lk-9, was revealed to possess an (aS)-configurated biaryl axis by X-ray crystallographic analysis. Saponification of the separated bismenthyl carbonates gave enantioenriched samples of biquinolyl 6, and absolute stereochemical configurations were assigned to the two optical isomers as (−)-(aS)-6 and (+)-(aR)-6 by correlation with their respective progenitors, (−)-lk-9 and (+)-ul-9. First-order rate constants for the enantiomerization of 6 in water were obtained over the temperature range 316−366 K, and activation parameters were determined as ΔH⧧ = 34.0 kcal mol-1 and ΔS ⧧ = 18.7 cal mol-1 K-1 by Eyring plot analysis. A low level (AM1) computational study of the rotational dynamics of 6 showed excellent agreement with kinetic ...
Effect of Transfer Coefficients on MV and LV Flicker Levels

It has been suggested that the recommended flicker planning levels provided in IEC 61000 3-7 and IEEE 1453 are too restrictive for high-voltage and extra-high-voltage networks. The premise of this argument is based on a perceived increase in low-voltage (LV) flicker compatibility level. Some believe that flicker measurements made in Europe over a period of several years support the notion of an increased LV compatibility level; however, measurements performed by the authors in North America indicate otherwise. Analysis of authors' measurements suggests that the lack of customer complaints is due primarily to the effect of flicker transfer coefficients, rather than a presumed increase in LV compatibility level, and supports the continued use of Pst95%=1.0 as the LV flicker compatibility level.
Conjugate Heat Transfer Within a Heterogeneous Hierarchical Structure

Optimization of heat exchangers (HE), compact heat exchangers (CHE) and micro-heat exchangers by design of their basic structure is the focus of this work. Consistant models are developed to describe transport phenomena in a porous medium that take into account the scales and other characteristics of the medium morphology. Equation sets allowing for turbulence and two-temperature or two-concentration diffusion are obtained for non-isotropic porous media with interface exchange. The equations differ from known equations and were developed using a rigorous averaging technique, hierarchical modeling methodology, and fully turbulent models with Reynolds stresses and fluxes in the space of every pore. The transport equations are shown to have additional integral and differential terms. The description of the structural morphology determines the importance of these terms and the range of application of the closure schemes. A natural way to transfer from transport equations in a porous media with integral terms to differential equations with coefficients that could be experimentally or numerically evaluated and determined is described. The relationship between CFD, experiment and closure needed for the volume averaged equations is discussed. Mathematical models for modeling momentum and heat transport based on well established averaging theorems are developed. Use of a ‘porous media’ length scale is shown to be very beneficial in collapsing complex data onto a single curve yielding simple heat transfer and friction factor correlations. The general transport equations developed for a single phase fluid in a heat exchange medium have many more integral and differential terms than the homogenized or classical continuum mechanics equations. Once these terms are dealt with by closure, the resulting equation set is relatively simple and their solution is obtained using simple numerical methods quickly enough for multiple parameter optimization using Design of Experiment (DOE) or Genetic Algorithms (GA). Current efforts to significantly improve the performance of a HE for electronic cooling, a two temperature problem, and of a finned tube heat exchanger, a three temperature problem, are described.Copyright © 2010 by ASME
Outer bounds for multiterminal source coding via a strong data processing inequality

An intuitive outer bound for the multiterminal source coding problem is given. The proposed bound explicitly couples the rate distortion functions for each source and correlation measures which derive from a “strong” data processing inequality. Unlike many standard outer bounds, the proposed bound is not parameterized by a continuous family of auxiliary random variables, but instead only requires maximizing two ratios of divergences which do not depend on the distortion functions under consideration.
Computing with words-semantics

Summary form only given. The increasing amount of hyperlinked human knowledge available on the Web has shifted the research focus to the search engines that will deliver the needed information quickly. This demand has triggered a revisitation of the long-standing issue of semantics, which was never addressed adequately by information theory or linguistic theory. Fuzzy sets and fuzzy logic, on the other hand, provide a powerful mathematical tool in modeling "semantics." The organization and the manipulation of information, knowledge base construction and discovery,. information retrieval and logical inferencing all deal with semantics in a fundamental way. Unless we experience a breakthrough in understanding semantics, especially related to machine automation, it will be difficult to make a quantum jump in accessing, creating, and modifying information. This paper intends to bring to center stage the complex problems of semantics confronted while dealing with natural language. The paper demonstrates the ability of fuzzy sets and fuzzy logic to serve as a mathematical vehicle to model semantics in a significantly improved way. This will include taking a closer look at the PNL, Precisiated Natural Language, proposed by Zadeh.
Believe it or not: adding belief annotations to databases

We propose a database model that allows users to annotate data with belief statements. Our motivation comes from scientific database applications where a community of users is working together to assemble, revise, and curate a shared data repository. As the community accumulates knowledge and the database content evolves over time, it may contain conflicting information and members can disagree on the information it should store. For example, Alice may believe that a tuple should be in the database, whereas Bob disagrees. He may also insert the reason why he thinks Alice believes the tuple should be in the database, and explain what he thinks the correct tuple should be instead.We propose a formal model for Belief Databases that interprets users' annotations as belief statements. These annotations can refer both to the base data and to other annotations. We give a formal semantics based on a fragment of multi-agent epistemic logic and define a query language over belief databases. We then prove a key technical result, stating that every belief database can be encoded as a canonical Kripke structure. We use this structure to describe a relational representation of belief databases, and give an algorithm for translating queries over the belief database into standard relational queries. Finally, we report early experimental results with our prototype implementation on synthetic data.
Palladium(II)-catalyzed selective monofluorination of benzoic acids using a practical auxiliary: a weak-coordination approach.

Difluorinated products can also be prepared under similar conditions by simply changing the stoichiometry of the fluorinating agent.
Finslerian quantum field theory

Abstract Finsler geometry suggests a generalization of the Riemannian structure of spacetime to include dependence of the spacetime metric and associated invariant tensor fields on the four-velocity coordinates as well as the spacetime coordinates of the observer. It is useful to consider the tangent bundle of spacetime with spacetime in the base manifold and four-velocity space in the fiber. A physical basis for the differential geometric structure of the spacetime tangent bundle is provided by the universal upper limit on proper acceleration relative to the vacuum. It is then natural to consider a quantum field having a vanishing eigenvalue when acted on by the Laplace–Beltrami operator of the spacetime tangent bundle. On this basis a quantum field theory can be constructed having a built-in intrinsic regularization at the Planck scale, and finite vacuum energy density. This may provide insight concerning the cosmological constant and the accelerating universe.
A Robin formula for the Fekete-Leja transfinite diameter

We generalize the classical Robin formula to higher dimensions. Mathematics Subject Classification (2000) Primary 32U35 · 32U20 · 14G40; Secondary 31B15 · 31C10 The purpose of this note is to give a formula for the Fekete-Leja transfinite diameter on CN , generalizing the classical Robin formula d∞(E) = e−V(E) for the usual transfinite diameter. We will disengage this from a formula for the sectional capacity proved in arithmetic intersection theory ([5], Theorem 1.1, p. 233). First recall the definition of the Fekete-Leja transfinite diameter for a compact set E ⊂ CN (see [1,16]). Consider the set of monomials zk = z1 1 · · · zN N in the polynomial ring C[z] = C[z1, . . . , zN]. Let (n) ⊂ C[z] be the space of polynomials of total degree at most n, and let K(n) = {k ∈ ZN : ki ≥ 0,k1 + · · · + kN ≤ n} be the index set for the monomial basis of (n). Put qn = #(K(n)) = (n+N n ) . Fixing n, take qn independent vector variables zi = (zi1, . . . , ziN) ∈ CN , i = 1, . . . ,qn. Let k1, . . . ,kqn be the indices in K(n). The Vandermonde determinant Qn(z1, . . . , zqn) := det(zj i )n i,j=1 Work supported in part by NSF grant DMS-0300784. R. Rumely (B) Department of Mathematics, University of Georgia, Athens, GA 30602, USA e-mail: rr@math.uga.edu
DNA associations: Packing calculations in A-, B-, and Z-DNA structures

Abstract A detailed theoretical study has been carried out to examine the modes of DNADNA interactions on the basis of hard-sphere contact criteria. Two helices of identical structure and length are oriented side-by-side and their relative positions are controlled by translations along and rotations about specific axes. Short atomic contacts between pairs of atoms in the structures are assessed and contact-free configurations are compiled. The computed contact-free arrangements of A, B, and Z double helices are found to be remarkably similar to the packing motifs observed in DNA crystals and stretched fibers. Equally interesting in the study are the broad ranges of sterically acceptable arrangements that preserve the overall packing morphology of neighboring duplexes: Among the most notable morphological features in the helical complexes are extended “super” major and minor grooves which might facilitate the wrapping and packaging of DNA chains in supramolecular assemblies. The hard-sphere computations, however, are insufficient for quantitative interpretation of the packing of DNA helices in the solid state. The results are, nevertheless, a useful starting point for energy based studies as well as relevant to the analysis of long-range interactions in DNA supercoils and cruciforms.
FUSE Observations of Atomic Abundances and Molecular Hydrogen in the Leading Arm of the Magellanic Stream

We present Far-Ultraviolet Spectroscopic Explorer observations of the atomic and molecular absorption in high-velocity cloud HVC 287.5]22.5]240, which lies in front of the ultraviolet-bright nucleus of the Seyfert 1 galaxy NGC 3783. We detect N I ,N II ,S iII, and Fe II and set limits on the amount of H 2 , absorption due to P III ,A rI, and Fe III. We extend the earlier metallicity and dust-depletion measurements made by Lu and collaborators by examining the relative gas-phase abundances of Si, P, S, and Fe. Corrections to the derived gas-phase abundances due to ionized gas in the HVC are small ([15%). The HVC has metallicity 0.2¨0.4 solar, similar to that of the Small Magellanic Cloud. The relative abundance pattern for the elements studied resembles that of warm gas in the Small Magellanic Cloud (SMC), which supports the idea that this HVC is part of the tidally stripped leading arm of the Magellanic Stream. The abundance pattern implies that the HVC contains dust grains that have been processed signi—cantly; it is likely that the grain mantles have been modi—ed or stripped back to expose the grain cores. We have identi—ed more than 30 lines of arising in the HVC from rotational levels J \ 0t o H 2 J \ 3. Synthetic spectra and a curve of growth —tted to these lines with b \ 12 km s~1 indicate that and A two-component temlog [N(H 2 )] \ 16.80 ^ 0.10 f H2 \ 2N(H 2 )/[N(H I) ] 2N(H 2 )] \ 1.6 ] 10~3. perature distribution is necessary to explain the observed populations of the rotational levels. We H 2 —nd K, and K, indicating that the conditions in the molecular gas are more T 01 \ 133 ~2137 T 23 \ 241 ~1720 similar to those found for diUuse molecular clouds in the Galactic halo than to those for molecular clouds in the Galactic disk. From an analysis of the J \ 2 and J \ 3 populations, we —nd an absorption rate (at 1000 of times the average value in the solar neighborhood. The presence of molecuAe ) b uv \ 0.1 lar gas in the HVC requires that either the formed in situ or that molecules formed within the SMC H 2 survived tidal stripping. We favor the latter possibility because of the long formation time (D108 yr) H 2
A Normalized Modal Eigenvalue Approach for Resolving Modal Interaction

Modal interaction refers to the way that the modes of a structure interact when its geometry and material properties are perturbed. The amount of interaction between the neighboring modes depends on the closeness of the natural frequencies, the mode shapes, and the magnitude and distribution of the perturbation. By formulating the structural eigenvalue problem as a normalized modal eigenvalue problem, it is shown that the amount of interaction in two modes can be simply characterized by six normalized modal parameters and the difference between the normalized frequencies. In this paper, the statistical behaviors of the normalized frequencies and modes are investigated based on a perturbation analysis. The results are independently verified by Monte Carlo simulations.
Real-world injury patterns associated with Hybrid III sternal deflections in frontal crash tests

Objective: This study investigated the relationship between the peak sternal deflection measurements recorded by the Hybrid III 50th percentile male anthropometric test device (ATD) in frontal crash tests and injury and fatality outcomes for drivers in field crashes. Methods: ATD sternal deflection data were obtained from the Insurance Institute for Highway Safety's 64 km/h, 40 percent overlap crashworthiness evaluation tests for vehicles with seat belt crash tensioners, load limiters, and good-rated structure. The National Automotive Sampling System Crashworthiness Data System (NASS-CDS) was queried for frontal crashes of these vehicles in which the driver was restrained by a seat belt and air bag. Injury probability curves were calculated by frontal crash type using the injuries coded in NASS-CDS and peak ATD sternal deflection data. Fatality Analysis Reporting System (FARS) front-to-front crashes with exactly one driver death were also studied to determine whether the difference in measured sternal def...
Fixed points of analytic actions of supersoluble Lie groups on compact surfaces

Author(s): Hirsch, Morris W; Weinstein, Alan D | Abstract: It is shown that every real analytic action of a connected supersoluble Lie group on a compact surface with nonzero Euler characteristic has a fixed point. This implies that E. Lima's fixed point free action of the affine group of the line on the 2-sphere S cannot be approximated by analytic actions. An example is given of an analytic, fixed point free action on S of a solvable group that is notsupersoluble.
Cultural Models of Bodily Images of Women Teachers

Cultural models are simplified images and storylines that encapsulated what is regarded as typical for a social group. Cultural models of teachers include body images of dress, adornment, and comportment, and are useful in examining society’s standards and values. Two participants, Erin and Gabbie (pseudonyms), shared stories about their tattoos, which in the U.S. have historically been seen as a mode of resistance. These tattoos that reflected the teachers’ personal lives were regarded in light of the cultural model of the U.S. teacher, a typically conservatively dressed and coiffed female. According to discourse analysis of the participants’ stories, each teacher’s students did not interpret these tattoos in the same ways. Erin’s students were surprised at the tattoo and interpreted it as a sign she no longer fit the typical teacher mold. Gabbie’s students were not surprised at the tattoo but noted it as confirmatory evidence that she fit the needs of the alternative, nonmainstream school context where the cultural model would be ill suited. This analysis makes a case for more complex interpretations of teachers’ bodies that do not fit the mainstream cultural models of teachers.
A Path Integral Formalism for Non-equilibrium Hamiltonian Statistical Systems

A path integral formalism for non-equilibrium systems is proposed based on a manifold of quasi-equilibrium densities. A generalized Boltzmann principle is used to weight manifold paths with the exponential of minus the information discrepancy of a particular manifold path with respect to full Liouvillean evolution. The likelihood of a manifold member at a particular time is termed a consistency distribution and is analogous to a quantum wavefunction. The Lagrangian here is of modified generalized Onsager-Machlup form. For large times and long slow timescales the thermodynamics is of Ottinger form. The proposed path integral has connections with those occuring in the quantum theory of a particle in an external electromagnetic field. It is however entirely of a Wiener form and so practical to compute. Finally it is shown that providing certain reasonable conditions are met then there exists a unique steady-state consistency distribution.
3D visualization to support airport security operations

In the summer of 2000, the National Safe Skies Alliance awarded a project to the Applied Visualization Center at the University of Tennessee to develop a 3D computer tool to assist the US Federal Aviation Administration security group, now the Transportation Security Administration, in evaluating new equipment and procedures to improve airport checkpoint security. At the time of this writing, numerous detection equipment models, three specific airports, and a placement and passenger flow simulation tool for airport security planners have been developed. Similar tools have been constructed for simulating cargo/baggage inspection and other airport security operations. An extension of the original effort to consolidate the tools is currently underway.
WHY ARE PRICES STICKY? THE DYNAMICS OF WHOLESALE GASOLINE PRICES

The menu-cost interpretation of sticky prices implies that the probability of a price change should depend on the past history of prices and fundamentals only through the gap between the current price and the frictionless price. We find that this prediction is broadly consistent with the behavior of nine Philadelphia gasoline wholesalers. Nevertheless, we reject the menu-cost model as a literal description of these firms' behavior, arguing instead that price stickiness arises from strategic considerations of how customers and competitors will react to price changes.
Mapping the stereotyped behaviour of freely moving fruit flies

A frequent assumption in behavioural science is that most of an animal's activities can be described in terms of a small set of stereotyped motifs. Here, we introduce a method for mapping an animal's actions, relying only upon the underlying structure of postural movement data to organize and classify behaviours. Applying this method to the ground-based behaviour of the fruit fly, Drosophila melanogaster, we find that flies perform stereotyped actions roughly 50% of the time, discovering over 100 distinguishable, stereotyped behavioural states. These include multiple modes of locomotion and grooming. We use the resulting measurements as the basis for identifying subtle sex-specific behavioural differences and revealing the low-dimensional nature of animal motions.
Decoding individual natural scene representations during perception and imagery.

We used a multi-voxel classification analysis of functional magnetic resonance imaging (fMRI) data to determine to what extent item-specific information about complex natural scenes is represented in several category-selective areas of human extrastriate visual cortex during visual perception and visual mental imagery. Participants in the scanner either viewed or were instructed to visualize previously memorized natural scene exemplars, and the neuroimaging data were subsequently subjected to a multi-voxel pattern analysis (MVPA) using a support vector machine (SVM) classifier. We found that item-specific information was represented in multiple scene-selective areas: the occipital place area (OPA), parahippocampal place area (PPA), retrosplenial cortex (RSC), and a scene-selective portion of the precuneus/intraparietal sulcus region (PCu/IPS). Furthermore, item-specific information from perceived scenes was re-instantiated during mental imagery of the same scenes. These results support findings from previous decoding analyses for other types of visual information and/or brain areas during imagery or working memory, and extend them to the case of visual scenes (and scene-selective cortex). Taken together, such findings support models suggesting that reflective mental processes are subserved by the re-instantiation of perceptual information in high-level visual cortex. We also examined activity in the fusiform face area (FFA) and found that it, too, contained significant item-specific scene information during perception, but not during mental imagery. This suggests that although decodable scene-relevant activity occurs in FFA during perception, FFA activity may not be a necessary (or even relevant) component of one’s mental representation of visual scenes.
THE SPITZER VIEW OF FR I RADIO GALAXIES: ON THE ORIGIN OF THE NUCLEAR MID-INFRARED CONTINUUM

We present Spitzer mid-infrared (MIR) spectra of 25 FR I radio galaxies and investigate the nature of their MIR continuum emission. MIR spectra of star-forming galaxies and quiescent elliptical galaxies are used to identify host galaxy contributions while radio/optical core data are used to isolate the nuclear nonthermal emission. Out of the 15 sources with detected optical compact cores, four sources are dominated by emission related to the host galaxy. Another four sources show signs of warm, nuclear dust emission: 3C15, 3C84, 3C270, and NGC 6251. It is likely that these warm dust sources result from hidden active galactic nuclei of optical spectral type 1. The MIR spectra of seven sources are dominated by synchrotron emission, with no significant component of nuclear dust emission. In parabolic spectral energy distribution fits of the nonthermal cores FR Is tend to have lower peak frequencies and stronger curvature than blazars. This is roughly consistent with the common picture in which the core emission in FR Is is less strongly beamed than in blazars.
The Heat Flow of the CCR Algebra

Let Pf ( x ) =− if ′( x ) and Qf ( x ) = xf ( x ) be the canonical operators acting on an appropriate common dense domain in L 2 (ℝ). The derivations D P ( A ) = i ( PA − AP ) and D Q ( A ) = i ( QA − AQ ) act on the *-algebra [Ascr ] of all integral operators having smooth kernels of compact support, for example, and one may consider the noncommutative ‘Laplacian’, L = D 2 P + D 2 Q , as a linear mapping of [Ascr ] into itself. L generates a semigroup of normal completely positive linear maps on [Bscr ]( L 2 (ℝ)), and this paper establishes some basic properties of this semigroup and its minimal dilation to an E 0 -semigroup. In particular, the author shows that its minimal dilation is pure and has no normal invariant states, and he discusses the significance of those facts for the interaction theory introduced in a previous paper. There are similar results for the canonical commutation relations with n degrees of freedom, where 1 [les ] n
Strain-dependent twist–stretch elasticity in chiral filaments

Coupling between axial and torsional degrees of freedom often modifies the conformation and expression of natural and synthetic filamentous aggregates. Recent studies on chiral singlewalled carbon nanotubes and B-DNA reveal a reversal in the sign of the twist–stretch coupling at large strains. The similarity in the response in these two distinct supramolecular assemblies and at high strains suggests a fundamental, chirality-dependent nonlinear elastic behaviour. Here we seek the link between the microscopic origin of the nonlinearities and the effective twist–stretch coupling using energy-based theoretical frameworks and model simulations. Our analysis reveals a sensitive interplay between the deformation energetics and the sign of the coupling, highlighting robust design principles that determine both the sign and extent of these couplings. These design principles have already been exploited by nature to dynamically engineer such couplings, and have broad implications in mechanically coupled actuation, propulsion and transport in biology and technology.
Some Pattern Recognition Challenges in Data-Intensive Astronomy

We review some of the recent developments and challenges posed by the data analysis in modern digital sky surveys, which are representative of the information-rich astronomy in the context of Virtual Observatory. Illustrative examples include the problems of an automated star-galaxy classification in complex and heterogeneous panoramic imaging data sets, and an automated, iterative, dynamical classification of transient events detected in synoptic sky surveys. These problems offer good opportunities for productive collaborations between astronomers and applied computer scientists and statisticians, and are representative of the kind of challenges now present in all data-intensive fields. We discuss briefly some emergent types of scalable scientific data analysis systems with a broad applicability.
On the Optimality of Myopic Sensing in Multi-State Channels

We consider the channel sensing problem arising in opportunistic scheduling over fading channels, cognitive radio networks, and resource constrained jamming. The same problem arises in many other areas of science and technology as it is an instance of restless bandit problems. The communication system consists of N channels. Each channel is modeled as a multi-state Markov chain. At each time instant a user selects one channel to sense and uses it to transmit information. A reward depending on the state of the selected channel is obtained for each transmission. The objective is to design a channel sensing policy that maximizes the expected total reward collected over a finite or infinite horizon. This problem can be viewed as an instance of restless bandit problems, for which the form of optimal policies is unknown in general. We discover sets of conditions sufficient to guarantee the optimality of a myopic sensing policy; we show that under one particular set of conditions the myopic policy coincides with the Gittins index rule.
Magnetization transfer imaging in the detection of injury associated with mild head trauma.

BACKGROUND AND PURPOSE: Most traumatic brain injuries are classified as mild, yet in many instances cognitive deficits result. The purpose of this study was to investigate possible relationships between quantitative magnetization transfer imaging (MTI) and neurocognitive findings in a cohort of patients with mild head trauma but negative findings on conventional MR images. METHODS: We examined 13 patients and 10 healthy volunteers with a standard MR protocol including fast spin-echo and gradient-echo imaging, to which was added quantitative MTI. MTI was performed with a modified gradient-echo sequence incorporating pulsed, off-resonance saturation. Both region-of-interest analysis and contour plots were obtained from the MTI data. A subgroup of nine patients was examined with a battery of neuropsychological tests, comprising 25 measures of neurocognitive ability. RESULTS: The magnetization transfer ratio (MTR) in the splenium of the corpus callosum was lower in the patient group as compared with the control group, but no significant reduction in MTR was found in the pons. Individual regional MTR values were significantly reduced in two cases, and contour plot analysis revealed focal areas of abnormality in the splenium of four patients. All the patients showed impairment on at least three measures of the neuropsychological test battery, and in two cases a significant correlation was found between regional MTR values and neuropsychological performance. CONCLUSION: Our results suggest that MTI and contour plot analysis may add sensitivity to the MR imaging examination of patients with traumatic brain injury.
Computing the core of ideals in arbitrary characteristic

Abstract Let R be a local Gorenstein ring with infinite residue field of arbitrary characteristic. Let I be an R-ideal with g = ht I > 0 , analytic spread l, and let J be a minimal reduction of I. We further assume that I satisfies G l and depth R / I j ⩾ dim R / I − j + 1 for 1 ⩽ j ⩽ l − g . The question we are interested in is whether core ( I ) = J n + 1 : ∑ b ∈ I ( J , b ) n for n ≫ 0 . In the case of analytic spread Polini and Ulrich show that this is true with even weaker assumptions [C. Polini, B. Ulrich, A formula for the core of an ideal, Math. Ann. 331 (2005) 487–503, Theorem 3.4]. We give a negative answer to this question for higher analytic spreads and suggest a formula for the core of such ideals.
Does the time-consistency problem explain the behavior of inflation in the United States? ☆

Abstract This paper derives the restrictions imposed by Barro and Gordon's theory of time-consistent monetary policy on a bivariate time-series model for inflation and unemployment and tests those restrictions using quarterly US data from 1960 through 1997. The results show that the data are consistent with the implications of the theory for the long-run behavior of the two variables, indicating that the theory can explain the initial rise and subsequent fall of inflation over the past four decades. The results also suggest that the theory must be extended to account more fully for the short-run dynamics that appear in the data.