cssi/SciSciGPT-SciSciNet huggingface dataset:
Three-Dimensional Blade Boundary Layer and Endwall Flow Development in the Nozzle Passage of a Single Stage Turbine

The three-dimensional viscous flow field development in the nozzle passage of an axial flow turbine stage was measured using a x hot-wire probe. The measurements were carried out at two axial stations on the endwall and vane surfaces and at several spanwise and pitchwise locations. Static pressure measurements and flow visualization, using a fluorescent oil technique, were also performed to obtain the location of transition and the endwall limiting streamlines. The boundary layers on the vane surface were found to be very thin and mostly laminar, except on the suction surface downstream of 70 percent axial chord. Strong radial pressure gradient, especially close to the suction surface, induces strong radial flow velocities in the trailing edge regions of the blade. On the endwalls, the boundary layers were much thicker, especially near the suction corner of the casing surface, caused by the secondary flow. The secondary flow region near the suction surface-casing corner indicated the presence of the passage vortex detached from the vane surface. The boundary layer code accurately predicts the three-dimensional boundary layers on both vane surfaces and endwall in the regions where the influence of the secondary flow is small
Fluorination of substituted veratroles via regioselective mercuration

Abstract A regioselective aromatic ring fluorination of substituted veratroles was achieved via a mercuration-fluorodemercuration reaction.
Dispersive shock waves with nonlocal nonlinearity

We consider dispersive optical shock waves in nonlocal nonlinear media. Experiments are performed using spatial beams in a thermal liquid cell, and results agree with a hydrodynamic theory of propagation.
Casa Pite: Papudo, Chile

Resumen es: La tentacion de acercarse al limite, de establecer una fuerte relacion interior-exterior es exacerbada por la fuerte presencia del mar y una pendiente ab...
Development of a vortex-lift-design method and application to a slender maneuver-wing configuration

A procedure has been developed to optimize the mean camber surface of a cranked slender wing having leading-edge vortex flow at transonic maneuver conditions using the suction analogy. This type of flow was assumed because it was anticipated that the slenderness of the wing would preclude attached flow at the required lift coefficient. A constraint was imposed in that the camber deflections were to be compatible with a realistic structural-box requirement. The resulting application yielded mean camber shapes which produced effective suction levels equivalent to 11% of the full-planar leading-edge value at the design lift coefficient. A a
Design Loads for Wind Turbines Using the Environmental Contour Method

When interest is in establishing ultimate design loads for wind turbines such that a service life of, say, 20 years is assured, alternative procedures are available. One class of methods works by employing statistical loads extrapolation techniques following development first of 10-minute load maxima distributions (conditional on inflow parameters such as mean wind speed and turbulence intensity). The parametric conditional load distributions require extensive turbine response simulations over the entire inflow parameter range. We will refer to this first class of methods as the “parametric method.” An alternative method is based on traditional structural reliability concepts and isolates only a subset of interesting inflow parameter combinations that are easily first found by working backward from the target return period of interest. This so-called inverse reliability method can take on various forms depending on the number of variables that are modeled as random. An especially attractive form that separates inflow (environmental) variables from turbine load∕response variables and further neglects variability in the load variables given inflow is referred to as the environmental contour (EC) method. We shall show that the EC method requires considerably smaller amounts of computation than the parametric method. We compare accuracy and efficiency of the two methods in 1- and 20-year design out-of-plane blade bending loads at the root of two 1.5 MW turbines. Simulation models for these two turbines with contrasting features, in that one is stall-regulated and the other pitch-regulated, are used here. Refinements to the EC method that account for the effects of the neglected response variability are proposed to improve the turbine design load estimates.
An Outcomes Study of Cochlear Implants in Deaf Patients: Audiologic, Economic, and Quality-of-Life Changes

Objectives: To investigate and quantitate the changes in economic, emotional, and health-related quality of life after cochlear implantation. Subjects: Nine patients between the ages of 18 and 60 years who qualified for surgery. Methods: Patients underwent assessment using four socioeconomic indicator scales administered preoperatively, and at 6 months, 1 year, 2 years, 30 months, and 3 years postoperatively. All patients continued to use their cochlear implants during the 3-year follow-up period. Results: Uniform and systematic improvement in quality of life and psychologic well-being, and a steady increase in mean personal income for the group that underwent implantation, supporting the contention that cochlear implantation is a beneficial surgical procedure for profoundly deaf patients. (Arch Otolaryngol Head Neck Surg. 1995;121:398-404)
Bounds for singular fractional integrals and related Fourier integral operators

Abstract We prove sharp Lp−Lq endpoint bounds for singular fractional integral operators and related Fourier integral operators, under the nonvanishing rotational curvature hypothesis.
Output reversibility in linear discrete-time dynamical systems

Output reversibility involves dynamical systems where for every initial condition and the corresponding output there exists another initial condition such that the output generated by this initial condition is a time-reversed image of the original output with the time running forward. Through a series of necessary and sufficient conditions, we characterize output reversibility in linear discrete-time dynamical systems in terms of the geometric symmetry of its eigenvalue set with respect to the unit circle in the complex plane. Furthermore, we establish that output reversibility of a linear continuous-time system implies output reversibility of its discretization. In addition, we present a control framework that allows to alter the system dynamics in such a way that a discrete-time system, otherwise not output reversible, can be made output reversible. Finally, we present numerical examples involving a discretization of a Hamiltonian system that exhibits output reversibility and an example of a controlled system that is rendered output reversible.
A New Analysis of RR Lyrae Kinematics in the Solar Neighborhood

Full space velocities are computed for a sample of 130 nearby RR Lyrae variables using both ground-based and Hipparcos proper motions. In many cases proper motions for the same star from multiple sources have been averaged to produce approximately a factor of 2 improvement in the transverse space velocity errors. In most cases, this exceeds the accuracy attained using Hipparcos proper motions alone. The velocity ellipsoids computed for halo and thick-disk samples are in agreement with those reported in previous studies. A distinct sample of thin-disk RR Lyrae variables has not been isolated, but there is kinematic evidence for some thin-disk contamination in our thick-disk samples. Using kinematic and spatial parameters, a sample of 21 stars with [Fe/H] < -1.0 and disklike kinematics have been isolated. From their kinematics and spatial distribution we conclude that these stars represent a sample of RR Lyrae variables in the metal-weak tail of the thick disk that extends to [Fe/H] = -2.05. In the halo samples, the distribution of V velocities is not Gaussian, even when the metal-weak thick-disk stars are removed. Possibly related, a plot of U and W velocities as a function of V velocity for the kinematically unbiased halo sample shows some curious structure. The cause of these kinematic anomalies is not clear. In addition, systematic changes to the distance scale within the range of currently accepted values of Mv(RR) are shown to significantly change the calculated halo kinematics. Fainter values of Mv(RR), such as those obtained by statistical parallax (~0.60 to 0.70 at [Fe/H] = -1.9), result in local halo kinematics similar to those reported in independent studies of halo kinematics, while brighter values of Mv(RR), such as those obtained through recent analysis of Hipparcos subdwarf parallaxes (~0.30 to 0.40 at [Fe/H] = -1.9), result in a halo with retrograde rotation and significantly enlarged velocity dispersions.
Measurement of the Optical Properties of Nanorose

Nanorose is used to target macrophages in atherosclerotic plaques. Experimental measurement and simulation of nanorose absorption (?a) and scattering (?s) cross-sections give, respectively, ?a= (3.1±0.5)×10-14m2and ?a/?s= 10.5.
Numerical relativity and compact binaries

Numerical relativity is the most promising tool for theoretically modeling the inspiral and coalescence of neutron star and black hole binaries, which, in turn, are among the most promising sources of gravitational radiation for future detection by gravitational wave observatories. In this article we review numerical relativity approaches to modeling compact binaries. Starting with a brief introduction to the 3+1 decomposition of Einstein's equations, we discuss important components of numerical relativity, including the initial data problem, reformulations of Einstein's equations, coordinate conditions, and strategies for locating and handling black holes on numerical grids. We focus on those approaches which currently seem most relevant for the compact binary problem. We then outline how these methods are used to model binary neutron stars and black holes, and review the current status of inspiral and coalescence simulations.
Combined space and time convergence analysis of a compressible flow algorithm

In this study, we quantify both the spatial and temporal convergence behavior simultaneously for various algorithms for the two-dimensional Euler equations of gasdynamics. Such an analysis falls under the rubric of verification, which is the process of determining whether a simulation code accurately represents the code developers description of the model (e.g., equations, boundary conditions, etc.). The recognition that verification analysis is a necessary and valuable activity continues to increase among computational fluid dynamics practicioners. Using computed results and a known solution, one can estimate the effective convergence rates of a specific software implementation of a given algorithm and gauge those results relative to the design properties of the algorithm. In the aerodynamics community, such analyses are typically performed to evaluate the performance of spatial integrators; analogous convergence analysis for temporal integrators can also be performed. Our approach combines these two usually separate activities into the same analysis framework. To accomplish this task, we outline a procedure in which a known solution together with a set of computed results, obtained for a number of different spatial and temporal discretizations, are employed to determine the complete convergence properties of the combined spatio-temporal algorithm. Such an approach is of particular interest formore » Lax-Wendroff-type integration schemes, where the specific impact of either the spatial or temporal integrators alone cannot be easily deconvolved from computed results. Unlike the more common spatial convergence analysis, the combined spatial and temporal analysis leads to a set of nonlinear equations that must be solved numerically. The unknowns in this set of equations are various parameters, including the asymptotic convergence rates, that quantify the basic performance of the software implementation of the algorithm.« less
Interatomic interactions in solids: An effective-medium approach.

The description of the total energy of a solid in terms of the effective-medium theory has been studied. With use of the density-functional theory, an exact symmetric formula is presented for describing the total energy in terms of the embedding energies of individual atoms. Different approximate formulas are derived and compared to the conventional pair-potential representation, to the model of Gordon and Kim, and to the semiempirical embedded-atom scheme of Daw and Baskes. The theory is applied to estimate the pair potential in the rare gases He, Ne, and Ar, and the cohesive properties of Al metal. A fair agreement with the experimental results is obtained.
Mortgage Valuation Under Optimal Prepayment

Mortgage originators offer borrowers various combinations of "points"--loan fees--and coupon: high points and low coupon or low points and high coupon. In this article points are interpreted as a device serving to separate borrowers with high prepayment probabilities from those with low prepayment probabilities. Borrowers and lenders are treated symmetrically: both are risk neutral and both have complete and frictionless access to credit markets (implying that borrowers can finance points if they wish), except that borrowers' prepayment speeds are private knowledge. Equilibria are derived, both when borrowers cannot prepay voluntarily and when they can. Article published by Oxford University Press on behalf of the Society for Financial Studies in its journal, The Review of Financial Studies.
Effective transport properties of random composites: Continuum calculations versus mapping to a network

The effective transport properties and percolation of continuum composites have commonly been studied using discrete models, i.e., by mapping the continuum to a lattice or network. In this study we instead directly solve the continuum transport equations for composite microstructures both analytically and numerically, and we extract the continuum percolation threshold and scaling exponents for the two-dimensional square tile system. We especially focus on the role of corner contacts on flux flow and further show that mapping such ``random checkerboard'' systems to a network leads to a spurious secondary percolation threshold and causes shifts in the critical scaling exponents of the effective transport properties.
A Chiral Lewis Acid Strategy for Enantioselective Allylic C ? H Oxidation

C–H oxidation reactions have the potential to significantly streamline synthetic processes. However, to be useful for the synthesis of complex molecules, these reactions must proceed with high levels of chemo-, regio-, and stereoselectivity, Chiral bisoxazoline/copper-catalyzed systems have shown promising levels of asymmetric induction in the enantioselective allylic C–H esterification of symmetrical, cyclic olefins. Application of these systems to complex substrates is limited by a lack of chemo- and regioselectivity as well as the need to use a large excess of reactant (4 to 10 equiv).[1] A direct allylic C–H oxidation route would significantly increase the efficiency of producing chiral allylic esters; their syntheses generally require lengthy sequences of functional-group manipulations from preoxidized materials.[2,3]
Trading hours, information flow, and international cross-listing

Abstract This paper analyzes the volatility of information-related price changes of internationally cross-listed stocks. Among stocks with identical overall listings, the rate of information flow into the prices of Japanese and British stocks during the same hours is significantly less than that of U.S. stocks during NYSE trading hours. The rate of information flow into prices when the NYSE is closed is greater for U.S. stocks cross-listed in Tokyo than for non-cross-listed U.S. stocks, but not for U.S. stocks cross-listed in London. Also, the rate of information flow into the prices of foreign stocks during NYSE trading hours increases as their NYSE volume increases. These results are consistent with the hypotheses that (a) information flows into prices at a greater rate when a stock's primary market is open than when it is closed, even if offshore trading opportunities are available; and (b) foreign trading does facilitate price discovery if there is sufficient trading activity in the foreign market.
Porphyrin system containing [2.2]paracyclophane units

Meso-tetrakis([2.2]paracyclophanyl)porphyrin was obtained from [2.2]paracyclophanecarbaldehyde and pyrrole. Replacement of phenyl groups in meso-tetraphenylporphyrin by paracyclophanyl substituents remarkably influences the electronic structure of the molecule, causing bathochromic shifts of all uv-vis absorption bands, and changing the ring current of the porphyrin core. The shifts in the electron spectrum are substantially greater than those observed for other porphyrin derivatives characterized by their extended π-electron systems, such as meso-tetrakis(2-phenylethenyl)porphyrin and meso-tetrakisbiphenylporphyrin.
Evidence for Detection of a Moving Magnetic Monopole

A very heavy particle passed through a balloon-borne stack of Cherenkov film, emulsion, and Lexan sheets. In 33 Lexan sheets it produced tracks expected of either a nucleus with Z ranging between 125 and 137 and with beta less than about 0.92 or a magnetic monopole with g = 137e. Its track structure in emulsion indicated it was moving downward with beta equal to 0.5 (plus 0.1 or minus 0.05) and was either a nucleus with Z equal to 80 or a monopole with g = 137e. These facts strongly favor identification of the particle as a magnetic monopole of strength g = 137e and mass greater than 200 times proton mass.
Unsteady Solid-Propellant Pressure Combustion Response Using a Piston Burner

A small-scale solid-propellant laboratory burner has been designed to operate under piston-driven oscillating conditions from 40-400 Hz and 300-900 kPa mean pressure, with 10% amplitudes. The device was used to investigate the burning-rate response of a wide-distribution, bimodal AP (2:200 μm)-HTPB (IPDI) composite propellant (MURI TKC#5b). Results show that mean pressure and exit temperature decrease with increasing frequency because of increased heat transfer associated with oscillatory gas motion. Propellant burning rate is calculated numerically from pressure, volume, and frequency data using mass and energy balances. The dynamic burning rate response appears to be nearly linear at low frequencies (<150 Hz) and increasingly nonlinear at higher frequencies because of an increasing combustion response magnitude with frequency and nearly constant relative pressure amplitude. In the range of frequencies determined to be most linear (40-150 Hz), the magnitude of the pressure-coupled frequency response ranges from 2 to 7 ′ 1, with burning rate lagging pressure by 50-75 deg. The results demonstrate the potential for the piston burner to measure pressure frequency response at low frequencies and also to measure nonlinear dynamic burn rates over a range of frequencies at high spectral resolution within a single test. The results also demonstrate that nonlinear response can appear as spectral structure in the apparent linear response when the data are interpreted linearly.
Finite temperature QCD: Progress and outstanding problems

I review recent progress in numerical simulations of finite temperature quantum chromodynamics and discuss the status of some outstanding problems. Included is (1) a discussion of recent results determining the temperature of the “phase transition” in full QCD, (2) a scaling analysis of the Polyakov loop variable, leading to the determination of a constituent quark free energy, (3) studies of critical behavior near the phase transition in two-flavor QCD, (4) a discussion of problems and new results in thermodynamic simulations with Wilson fermions, (5) recent results in pure gauge theory with a mixed fundamental/adjoint action, and (6) the nonperturbative determination of the equation of state with dynamical fermions included. Finally I mention briefly new developments in efforts to construct a phenomenology of deconfinement and chiral symmetry restoration, namely (7) the dual superconducting model and (8) the instanton model.
Monte Carlo study of the Yukawa coupled two-spin Ising model

Abstract We consider a particular four state spin system composed of two Ising spins (sx, σx) with independent hopping parameters κ1 κ2, coupled by a bilinear Yukawa term, ysxσx. The Yukawa term is solely responsible for breaking the global Z2 × Z2 symmetry down to Z2. This model is intended as an illustration of general coupled Higgs system where scalars can arise both as composite and elementary excitations. For the Ising example in 2d, we give convincing numerical evidence of the universality of the two-spin system with the one-spin Ising model, by Monte Carlo simulations and finite size scaling analysis. We also show that as we approach the phase transition, universality arises by having a single correlation length that diverges.
A stronger Kolmogorov zero-one law for resource-bounded measure

Resource-bounded measure has been defined on the classes E, E2, ESPACE, E2SPACE, REC, and the class of all languages. It is shown here that if C is any of these classes and X is a set of languages that is closed under finite variations and has outer measure > 1 in C, then X has measure 0 in C. This result strengthens Lutz's resource-bounded generalization of the classical Kolmogorov zero-one law. It also gives a useful sufficient condition for proving that a set has measure 0 in a complexity class.
Coordinated intelligent control via epistemic utility theory

An approach to local reactive coordinated intelligent control based on the concept of an epistemic system, together with a principle of action that may be exercised locally, is presented. An epistemic system provides a mechanism for agents to characterize their knowledge corpora, options, goals, and beliefs. Levi's rule of epistemic utility provides a principle of action for decision making by comparing the informational value of rejection with the belief of correctness. Decisions are made locally and reactively, rather than globally. Coordination is implemented between agents by sharing and learning the epistemic systems of other agents. The resulting coordination model is nonhierarchical and heterogeneous, and its does not require explicit communication between agents. >
Intramolecular cationic cyclizations initiated by electrocyclic cleavage of cyclopropanes. Synthesis of trienic cyclopentane derivatives

Abstract The electrocyclic opening of dibromocyclopropane derivatives containing a tethered diene unit provides a good route to trienic cyclopentane derivatives. In one instance a bicyclic product arising from a fromal 4 + 2 cycloaddition process was observed.
Reductive deoxygenation by Cp2ZrHCl: Selective formation of imines via zirconation/hydrozirconation of amides

Abstract A general new process is described by which zirconium (IV) salts of secondary amides and lactams are transformed by Cp 2 ZrHCl directly into N-substituted imines in one step.
Turbulent Structure of a Stratified Supernova-driven Interstellar Medium

To study how supernova feedback structures the turbulent interstellar medium, we construct 3D models of vertically stratified gas stirred by discrete supernova explosions, including vertical gravitational fields and parameterized heating and cooling. The models reproduce many observed characteristics of the Galaxy, such as global circulation of gas (i.e., galactic fountain) and the existence of cold dense clouds in the galactic disk. Global quantities of the model such as warm and hot gas filling factors in the midplane, mass fraction of thermally unstable gas, and the averaged vertical density profile are compared directly with existing observations and shown to be broadly consistent. We find that energy injection occurs over a broad range of scales. There is no single effective driving scale, unlike the usual assumption for idealized models of incompressible turbulence. However, >90% of the total kinetic energy is contained in wavelengths shortward of 200 pc. The shape of the kinetic energy spectrum differs substantially from that of the velocity power spectrum, which implies that the velocity structure varies with the gas density. Velocity structure functions demonstrate that the phenomenological theory proposed by Boldyrev is applicable to the medium. We show that it can be misleading to predict physical properties such as the stellar initial mass function based on numerical simulations that do not include self-gravity of the gas. Even if all the gas in turbulently Jeans-unstable regions in our simulation is assumed to collapse and form stars in local free-fall times, the resulting total collapse rate is significantly lower than the value consistent with the input supernova rate. Supernova-driven turbulence inhibits star formation globally rather than triggering it.
RADIO OBSERVATIONS OF INTERPLANETARY MAGNETIC FIELD STRUCTURES OUT OF THE ECLIPTIC

New observations of the out-of-the ecliptic trajectories of type III solar radio bursts have been obtained from simultaneous direction finding measurements on two independent satellite experiments, IMP-6 with spin plane in the ecliptic, and RAE-2 with spin plane normal to the ecliptic. Burst exciter trajectories were observed which originated at the active region and then crossed the ecliptic plane at about 0.8 AU. We find a considerable large scale north-south component of the interplanetary magnetic field followed by the exciters. The apparent north-south and east-west angular source sizes observed by the two spacecraft are approximately equal, and range from 25° at 600 kHz to 110° at 80 kHz.
Finite‐amplitude Rotational Waves in Viscous Shear Flows

Growing finite-amplitude initially spanwise-independent two-dimensional rotational waves and their nonlinear interaction with unidirectional viscous shear flows of various strengths are considered. Both primary and secondary instabilities are studied, but only secondary instabilities are permitted to vary in the spanwise direction. A generalized Lagrangian-mean formulation is employed to describe wave-mean interactions, and a separate theory is constructed to account for the back effect of the developing mean flow on the wave field. Viscosity is seen to significantly complicate calculation of the back effect. The primary instability is seen to act as a platform for, and catalyst to, secondary instabilities. The analysis leads to an eigenvalue problem for the initial growth of the secondary instability, this being a generalization of the eigenvalue problem constructed by Craik for inviscid neutral waves. Two inviscid secondary instability mechanisms to longitudinal vortex form are observed: the first has as its basis the Craik–Leibovich type 2 mechanism. The second, which is as yet unproven, requires that both the wave and flow field distort in concert at all levels of shear. Both mechanisms excite exponential growth on a convective rather than diffusive scale in the presence of neutral waves, but growing waves alter that growth rate.
Muons after d - t fusion

We consider the forces acting on the muon following the d-t fusion and show that it is improper to neglect the \ensuremath{\alpha}-\ensuremath{\mu} Coulomb interaction. We further show that the muon separation from the \ensuremath{\alpha} particle is large at the time both interact with matter. This invalidates the assumption of pointlike source for transport studies of the muon evolution. We conclude, therefore, that the comment made by J\"andel is physically incorrect.
Spectral curves, opers and integrable systems

We establish a general link between integrable systems in algebraic geometry (expressed as Jacobian flows on spectral curves) and soliton equations (expressed as evolution equations on flat connections). Our main result is a natural isomorphism between a moduli space of spectral data and a moduli space of differential data, each equipped with an infinite collection of commuting flows. The spectral data are principal G-bundles on an algebraic curve, equipped with an abelian reduction near one point. The flows on the spectral side come from the action of a Heisenberg subgroup of the loop group. The differential data are flat connections known as opers. The flows on the differential side come from a generalized Drinfeld-Sokolov hierarchy. Our isomorphism between the two sides provides a geometric description of the entire phase space of the hierarchy. It extends the Krichever construction of special algebro-geometric solutions of the n-th KdV hierarchy, corresponding to G = SL n . An interesting feature is the appearance of formal spectral curves, replacing the projective spectral curves of the classical approach. The geometry of these (usually singular) curves reflects the fine structure of loop groups, in particular the detailed classification of their Cartan subgroups. To each such curve corresponds a homogeneous space of the loop group and a soliton system. Moreover the flows of the system have interpretations in terms of Jacobians of formal curves.
Optimally Adaptive Integration of Univariate Lipschitz Functions

We consider the problem of approximately integrating a Lipschitz function f (with a known Lipschitz constant) over an interval. The goal is to achieve an additive error of at most e using as few samples of f as possible. We use the adaptive framework: on all problem instances an adaptive algorithm should perform almost as well as the best possible algorithm tuned for the particular problem instance. We distinguish between ${\rm DOPT}$ and ${\rm ROPT}$, the performances of the best possible deterministic and randomized algorithms, respectively. We give a deterministic algorithm that uses $O({\rm DOPT}(f,\epsilon)\cdot\log(\epsilon^{-1}/{\rm DOPT}(f,\epsilon)))$ samples and show that an asymptotically better algorithm is impossible. However, any deterministic algorithm requires $\Omega({\rm ROPT}(f,\epsilon)^{2})$ samples on some problem instance. By combining a deterministic adaptive algorithm and Monte Carlo sampling with variance reduction, we give an algorithm that uses at most $O({\rm ROPT}(f,\epsilon)^{4/3}+{\rm ROPT}(f,\epsilon)\cdot\log(1/\epsilon))$ samples. We also show that any algorithm requires $\Omega({\rm ROPT}(f,\epsilon)^{4/3}+{\rm ROPT}(f,\epsilon)\cdot\log(1/\epsilon))$ samples in expectation on some problem instance (f,e), which proves that our algorithm is optimal.
On real time coding with limited lookahead

A real time coding system with lookahead consists of a memoryless source, a memoryless channel, an encoder, which encodes the source symbols sequentially with knowledge of future source symbols upto a fixed finite lookahead, d, with or without feedback of the past channel output symbols and a decoder, which sequentially constructs the source symbols using the channel output. The objective is to minimize the expected per-symbol distortion. For a fixed finite lookahead d ≥ 1 we invoke the theory of controlled Markov chains to obtain an average cost optimality equation (ACOE), the solution of which, denoted by D(d), is the minimum expected per-symbol distortion. With increasing d, D(d) bridges the gap between causal encoding, d = 0, where symbol by symbol encoding-decoding is optimal and the infinite lookahead case, d = ∞, where Shannon Theoretic arguments show that separation is optimal. We extend the analysis to a system with finite state decoders. For a Bernoulli source and binary symmetric channel, under hamming loss, we compute the optimal distortion for various source and channel parameters, and thus obtain computable bounds on D(d). We also identify regions of source and channel parameters where symbol by symbol encoding-decoding is sub-optimal. Finally, we demonstrate the wide applicability of our approach by applying it in additional coding scenarios, such as the case where the sequential decoder can take cost constrained actions affecting the quality or availability of side information about the source.
Jordan curves and funnel sections

A continuous ordinary vector differential equation in Euclidean space has a funnel of solutions through each initial condition. Its cross-section at time t is a continuum. Many continua are known to be funnel sections: For instance the circle is a cross-section of a continuous ODE y′=f(t,y) where y is a variable in the plane, but it is not known whether every Jordan curve J is a planar funnel section. In this paper we give sufficient conditions that imply J is a planar funnel section – “pierceability.” We show that pierceability is not generic when we put a fairly interesting complete metric on the space of Jordan curves. We also give proofs of several statements in the first authorʼs paper on funnel sections that appeared in the JDE in 1975.
Toward a general theory of transmutation

AbstractA general construction of transmutation operators is developed for selfad-jointoperatorsinGelfandtriples. Theoremsregardinganalyticity ofgeneralizedeigenfunctions and Paley-Wiener properties are proved. 1 Introduction The idea of transmutation operator (or transformation operator) B such that BP= QB for P and Q ordinary diﬀerential operators goes back to Gelfand, Levitan,Marchenko, Naimark, et. al. in the early 1950’s (cf. [23;25;28]). It was picked upagain by Delsarte and Lions, who established some fundamental ideas (cf. [26;31]),and subsequently it was developed in many directions (see e.g. [2;10-14;17;22;31]). Inthis article we indicate some constructions of a general nature which will be furtherenhanced in subsequent papers. We develop the theory via selfadjoint operators inGelfand triples and give some constructions of transmutation operators with variousdomains. Then various properties such as analyticity of generalized eigenfunctionsand Paley-Wiener properties are discussed, with results of various kinds.
Supersymmetric quantum mechanics of monopoles in N=4 Yang-Mills theory

Abstract A supersymmetric collective coordinate expansion of the monopole solution of N=4 Yang-Mills theory is performed resulting in an N=4 supersymmetric quantum mechanics on the moduli space of monopole solutions.
Bonding Low‐density Nanoporous Metal Foams Using Sputtered Solder

A method has been developed to bond low-density nanoporous copper foam components to an aluminum substrate using solder that is sputtered onto the surfaces. After assembling the components together and heating them to melt the solder, they were joined together by a layer of solder with a thickness of less than 2 μm.
Finding octonionic eigenvectors using Mathematica

Abstract The eigenvalue problem for 3 × 3 octonionic Hermitian matrices contains some surprises, which we have reported elsewhere [T. Dray, C.A. Manogue, The Octonionic Eigenvalue Problem, math.RA/9807126, Adv. Appl. Clifford Algebras, in press]. In particular, the eigenvalues need not be real, there are 6 rather than 3 real eigenvalues, and the corresponding eigenvectors are not orthogonal in the usual sense. The nonassociativity of the octonions makes computations tricky, and all of these results were first obtained via brute force (but exact) Mathematica computations. Some of them, such as the computation of real eigenvalues, have subsequently been implemented more elegantly; others have not. We describe here the use of Mathematica in analyzing this problem, and in particular its use in proving a generalized orthogonality property for which no other proof is known.
Is Exercise Adherence Associated with Clinical Outcomes in Patients with Advanced Heart Failure

AbstractBackground: There is limited research to support the effect of exercise adherence on clinical outcomes in patients with heart failure (HF). This secondary analysis was conducted on the intervention arm of an exercise training study in patients with HF to assess whether adherence and the dose of treatment exposure were associated with clinical outcomes, functional performance (maximum oxygen consumption [VO2], anaerobic threshold, and workload), and quality of life (QOL). Methods: Seventy-one patients (average age, 54 ± 12.5 years; male, 66%; Caucasian, 66%; married, 61%; New York Heart Association class II–III, 97.2%; and average ejection fraction, 26.4% ± 6.5%) were included in the current study. Patients with an increase ≥ 18% in the amount of exercise from baseline to 6 months, as measured by pedometers, were categorized as adherers (n = 38); patients who had no change or an increase in the amount of exercise of < 18% were categorized as nonadherers (n = 33). Results: The 2 groups were signific...
The 14TH Annual Intelligent Ground Vehicle Competition: intelligent teams creating intelligent ground robots

The Intelligent Ground Vehicle Competition (IGVC) is one of three, unmanned systems, student competitions that were founded by the Association for Unmanned Vehicle Systems International (AUVSI) in the 1990s. The IGVC is a multidisciplinary exercise in product realization that challenges college engineering student teams to integrate advanced control theory, machine vision, vehicular electronics, and mobile platform fundamentals to design and build an unmanned system. Teams from around the world focus on developing a suite of dual-use technologies to equip ground vehicles of the future with intelligent driving capabilities. Over the past 14 years, the competition has challenged undergraduate, graduate and Ph.D. students with real world applications in intelligent transportation systems, the military and manufacturing automation. To date, teams from over 50 universities and colleges have participated. This paper describes some of the applications of the technologies required by this competition and discusses the educational benefits. The primary goal of the IGVC is to advance engineering education in intelligent vehicles and related technologies. The employment and professional networking opportunities created for students and industrial sponsors through a series of technical events over the three-day competition are highlighted. Finally, an assessment of the competition based on participant feedback is presented.
Is Federalism the Reason for Policy Failure in Hurricane Katrina

Governmental responses to Hurricane Katrina are generally cited as policy failures. Media and popular analyses focus on the federal government's policy failures in hazard preparedness, response, and recovery. Meanwhile, disaster experts realize that disaster response is a shared intergovernmental responsibility. We examine the federal nature of natural disaster policy in the US to consider whether federalism, or other factors, had the greatest influence on the failures in Katrina. We find that some policy failures are related to policy design considerations based in federalism, but that the national focus on "homeland security" and the concomitant reduction in attention to natural hazards and disasters, are equally, if not more complicit, in the erosion of government disaster management capacity that was revealed in Hurricane Katrina. Copyright 2008, Oxford University Press.
MULTI-ELEMENT ABUNDANCE MEASUREMENTS FROM MEDIUM-RESOLUTION SPECTRA. II. CATALOG OF STARS IN MILKY WAY DWARF SATELLITE GALAXIES*

We present a catalog of Fe, Mg, Si, Ca, and Ti abundances for 2961 stars in eight dwarf satellite galaxies of the Milky Way (MW): Sculptor, Fornax, Leo I, Sextans, Leo II, Canes Venatici I, Ursa Minor, and Draco. For the purposes of validating our measurements, we also observed 445 red giants in MW globular clusters and 21 field red giants in the MW halo. Themeasurements are based on Keck/DEIMOS medium-resolution spectroscopy (MRS) combined with spectral synthesis. We estimate uncertainties in [Fe/H] by quantifying the dispersion of [Fe/H] measurements in a sample of stars inmonometallic globular clusters (GCs).We estimate uncertainties in Mg, Si, Ca, and Ti abundances by comparing to high-resolution spectroscopic abundances of the same stars. For this purpose, a sample of 132 stars with published high-resolution spectroscopy in GCs, the MW halo field, and dwarf galaxies has been observed with MRS. The standard deviations of the differences in [Fe/H] and ([α/Fe]) (the average of [Mg/Fe], [Si/Fe], [Ca/Fe], and [Ti/Fe]) between the two samples is 0.15 and 0.16, respectively. This catalog represents the largest sample of multi-element abundances in dwarf galaxies to date. The next papers in this series draw conclusions on the chemical evolution, gas dynamics, and star formation histories from the catalog presented here. The wide range of dwarf galaxy luminosity reveals the dependence of dwarf galaxy chemical evolution on galaxy stellar mass.
The Giant Flare From SGR 1806-20 And Its Radio Afterglow

The multi-wavelength observations of the 2004 December 27 Giant Flare (GF) from SGR 1806-20 and its long-lived radio afterglow are briefly reviewed. The GF appears to have been produced by a dramatic reconfiguration of the magnetic field near the surface of the neutron star, possibly accompanied by fractures in the crust. The explosive release of over 10{sup 46} erg (isotropic equivalent) powered a one-sided mildly relativistic outflow. The outflow produced a new expanding radio nebula, that is still visible over a year after the GF. Also considered are the constraints on the total energy in the GF, the energy and mass in the outflow, and on the external density, as well as possible implications for short {gamma}-ray bursts and potential signatures in high energy neutrinos, photons, or cosmic rays. Some possible future observations of this and other GFs are briefly discussed.
Darboux Coordinates and Instanton Corrections in Projective Superspace

By demanding consistency of the Legendre transform construction of hyperkahler metrics in projective superspace, we derive the expression for the Darboux coordinates on the hyperkahler manifold. We apply these results to study the Coulomb branch moduli space of 4D, $ \mathcal{N}=2 $ super-Yang-Mills theory (SYM) on $ {{\mathbb{R}}^3}\times {S^1} $ , recovering the results by GMN. We also apply this method to study the electric corrections to the moduli space of 5D, $ \mathcal{N}=1 $ SYM on $ {{\mathbb{R}}^3}\times {T^2} $ and give the Darboux coordinates explicitly.
Investigating the Determinants of Household Welfare in Cote D'Ivoire

To predict the effect of economic policies on household welfare, one should first understand which characteristics of households and of the localities in which they live, enable them to raise their welfare levels. This paper outlines a simple procedure for investigating the determinants of household welfare and demonstrates its use with recent data from Cote d'Ivoire. Despite the relative simplicity, much information is obtained from its use on cross-sectional survey data. Results specific to Cote d'Ivoire include : high (low) returns to education in urban (rural) areas; high benefits from cocoa land relative to coffee land; a significant impact on economic welfare from the availability of medical services, and no apparent benefits from agricultural extension services.
Optimizing the capture process in optical traps

We present techniques for the most efficient capture of atoms in a modified vaporcell magneto-optical trap. We explain how changing the size and power of the trapping beams affects the capture rate of the trap. We calculate the requirement of wall coatings designed to minimize the interaction of an alkali vapor with the wall and explain how this affects trapping efficiency. Finally, we present measurements of the performance of a “Dryfilm” coated cell.
Analysis of Limit Cycles in a Two-Transistor Saturable-Core Parallel Inverter

A familiar two-transistor saturable-core parallel inverter is modeled as a nonlinear negative resistance in parallel with energy-storage elements. The techniques of singular-point analysis are combined with piecewise linear techniques to permit determination of solution trajectories on the phase plane. Clear insight is provided, not only into steady-state oscillation, but also into transient behavior of the circuit. Experimental results confirming the analytical model are included.
Segmentation Using Material Information

One of the major problems in scene analysis is segmentation of a scene. In this paper a particular gray-level based segmentation technique is used to partition one particular scene. The same scene is then segmented into the material classes that comprise it by using the explicit information about the existing materials. A comparison of the two sets of results is made. A set of probabilities of detection based on various information about material boundaries is then derived. This set quantifies the limitations of gray-level based segmentation schemes in detecting the material boundaries, and can be used as a measure for comparing various segmentation techniques.
An advanced magnetic tape system for data processing

It is a truism that for any but the smallest digital data processing systems major attention must be be given to the provision of an adequate magnetic tape transport, reading and writing system, and means for insuring the correctness of information all the way from the central processor to the magnetic tape and back again. This paper will describe some of the above mentioned features of the Honeywell 800.
Marine submicron particles

Abstract The qualitative and quantitative analyses of submicron particles from coastal surface seawaters off California involved their separation by ultracentrifugation, visual examination by transmission electron microscopy (TEM), and the determination of elemental composition by energy dispersive spectroscopy. Particles fell into three classes: organic, both living and detrital; inorganic, such as iron colloids; clay minerals. The greatest abundance of particles occurred in the smaller than 120 nm size fraction. The mass concentration for particles sized between 5 and 120 nm is estimated to range between 0.03 and 0.09 mg l −1 . Particle numbers in this size range were greater than 10 9 particles ml −1 with the total surface area being 8 m 2 per cubic meter of seawater, or more. Particle size distributions in the smaller than 120 nm fraction showed numbers to increase nearly logarithmically with decreasing size. TEM examination indicates that many of these particles are in fact aggregates of granules 2–5 nm in size.
Valuing Recreational Benefits of a National Park in Andean Colombia

Protected undeveloped areas are an important tool for land conservation in developing nations. Efficient land allocation decisions and resource management requires knowledge of non-market benefits. Using travel cost and contingent valuation data from on-site interviews and secondary data on visitation, this study will value a national park in Columbia.
Collaborative Optimization Using Response Surface Estimation

The use of response surface estimation in collaborative optimization, an architecture for large-scale multidisciplinary design is described. Collaborative optimization preserves the autonomy of individual disciplines while providing a mechanism for coordinating the overall design problem and progressing toward improved designs. Collaborative optimization is a two-level optimization architecture, with discipline-specific optimizations free to specify local designs, and a global optimization that ensures that all of the discipline designs eventually agree on a single value for those variables that are shared in common. Results demonstrate how response surface models of subproblem optimization results improve the performance of collaborative optimization. The utility of response surface estimation in collaborative optimization depends on the generation of inexpensive accurate response surface models and the refinement of these models over several fitting cycles. Special properties of the subproblem optimization formulation are exploited to reduce the number of required subproblem optimizations to develop a quadratic model from O(n 2 ) to O(n/2). Response surface refinement is performed using ideas from trust region methods. Results for the combined approaches are compared through the design optimization of a tailless unmanned air vehicle in 44 design variables.