cssi/SciSciGPT-SciSciNet huggingface dataset:
Non-parametric calibration of the local volatility surface for European options using a second-order Tikhonov regularization

We calibrate the local volatility surface for European options across all strikes and maturities of the same underlying. There is no interpolation or extrapolation of either the option prices or the volatility surface. We do not make any assumption regarding the shape of the volatility surface except to assume that it is smooth. Due to the smoothness assumption, we apply a second-order Tikhonov regularization. We choose the Tikhonov regularization parameter as one of the singular values of the Jacobian matrix of the Dupire model. Finally we perform extensive numerical tests to assess and verify the aforementioned techniques for both volatility models with known analytical solutions of European option prices and real market option data.
Single-molecule spectroscopy of photosynthetic proteins in solution: exploration of structure–function relationships

In photosynthetic light harvesting, absorbed photoenergy transfers through networks of pigment–protein complexes to a central location, known as the reaction center, for conversion to chemical energy. This process occurs with remarkable near-unity quantum efficiency. Pigment–protein complexes exhibit emergent properties very different from those of their component molecules, resulting from interactions among the pigments and between the pigments and the surrounding protein environment. Thus, the precise molecular mechanisms of the energy transport process are complex and coupled, obscuring their molecular origin. Furthermore, because these interactions are sensitive to the molecular structure, they vary from complex to complex and vary in time for each individual complex due to fluctuations of the protein's conformation. To explore the effect of complex-to-complex variation, we study individual photosynthetic proteins, one at a time. We use a solution-phase, single-molecule technique, known as the Anti-Brownian Electrokinetic (ABEL) trap, to elucidate the conformational dynamics of single photosynthetic pigment–protein complexes without introducing additional perturbations from immobilization strategies. After reviewing the principles of the ABEL trap, we demonstrate its application to the study of several photosynthetic pigment–protein complexes. We demonstrate that the ABEL trap approach can lead to an increased understanding of photosynthetic complexes by presenting three examples: (1) analysis of photodegradation pathways, (2) characterization of complex-to-complex heterogeneity, and (3) identification of distinct functional forms.
When do supernova neutrinos of different flavors have similar luminosities but different spectra

Abstract Muon and tau neutrinos (νx) interact with protoneutron star matter only via neutral currents and exchange energy with the stellar gas predominantly by neutrino-electron scattering and neutrino-pair processes. In contrast, electron neutrinos and antineutrinos (νe and ν e ) are frequently absorbed and produced in charged-current mediated reactions with nucleons. Therefore the emergent νe and ν e originate from layers with lower temperatures further out in the star and are emitted with much lower characteristic spectral temperatures. In addition, a major contribution to the νe and ν e opacities is due to absorptions, while the opacity of νx is strongly dominated by scattering reactions with nucleons and nuclei in which the νx energy is (essentially) conserved. Therefore the νx distribution is nearly isotropic when νx decouple energetically and their outward diffusion is slowed down. In a generalized form to include this effect, the Stefan-Boltzmann Radiation Law can account for both the facts that νe ( ν e ) and νx emerge from the star with similar luminosities but with very different characteristic spectral temperatures. Simple analytical expressions to estimate the effect are given. If, as recently argued, even at densities significantly below nuclear matter density neutral-current scatterings were associated with considerable energy transfer between neutrino and target particle, one might expect spectral temperatures of νx much closer to those of νe and ν e . This is of relevance for the detection of neutrino signals from supernovae.
The Size of Exponential Sums on Intervals of the Real Line

We prove that there is a constant c>0 depending only on M≥1 and μ≥0 such that $$\int_y^{y+a}{ \bigl|g(t)\bigr| \, dt} \geq \exp \bigl(-c/(a\delta)\bigr), \quad a\delta \in (0,\pi],$$ for every g of the form $$g(t) = \sum_{j=0}^n{a_j e^{i\lambda_jt}},\quad a_j \in {\mathbb{C}}, \ |a_j| \leq Mj^\mu, \ |a_0|=1,\ n \in {\mathbb{N}} ,$$ where the exponents \(\lambda_{j} \in {\Bbb{R}}\) satisfy $$\lambda_0 = 0, \qquad \lambda_j \geq j\delta > 0,\quad j=1,2,\ldots,$$ and for every subinterval [y,y+a] of the real line. Establishing inequalities of this variety is motivated by problems in physics.
Implications of the Precautionary Principle: Is it a Threat to Science?

ABSTRACT Scientific research is of proven value to protecting public health and the environment from current and future problems. We explore the extent to which the Precautionary Principle is a threat to this role for science and technology. Not surprisingly for a relatively simple yet still incompletely defined concept, supporters of the Precautionary Principle come from different viewpoints, including a viewpoint that is at least uneasy with the role of science, and particularly its use in risk assessment. There are also aspects of the Precautionary Principle that inherently restrict obtaining and using science. The Hazardous Air Pollutant (HAP) provisions in the US Clean Air Act Amendments are an example of the Precautionary Principle, which both shifted the burden of proof so that the onus is now on showing a listed compound is harmless, and required maximum available control technology (MACT) instead of a primarily risk-based approach to pollution control. Since its passage in 1990 there has been a d...
The assembly of oligosaccharides from “standardized intermediates”: β-(1→3)-linked oligomers of d-galactose

Abstract Several 2- O -benzoyl-4,6-di- O -benzyl-3- O -R-α- d -galactopyranosyl chlorides, designed as general precursors of β-linked, interior d -galactopyranosyl residues in oligosaccharides, were tested in a sequential synthesis of the galactotriose β- d -Gal p -(1→3)-β- d -Gal p -(1→3)- d -Gal ( 19 ). The chlorides having R = tetrahydro-2-pyranyl and tert -butyldimethylsilyl gave excellent results whereas those having = 3-benzoylpropionyl and chloroacetyl were unsatisfactory. An activated disaccharide block ( 17 ), having R = 2,3-di- O -benzoyl-4,6-di- O -benzyl-β- d -galactopyranosyl, was also prepared and tested as a glycosyl donor. The coupling of 17 to 1-propenyl 2- O -benzoyl-4,6-di- O -benzyl-α- d -galactopyranoside ( 14 ), in the molar ratio 1.13:1, gave 64% of a trisaccharide derivative ( 18 ) that could be converted into 19 . This latter synthesis of 19 is efficient because all three galactose units are derived from 14 or its immediate precursor.
Space traffic management: Implementations and implications

Abstract Space traffic management means that space is no longer an open frontier; it means the space-faring nations have decided that there is a reason to bring order to near-Earth space. There are several ways space traffic management might be implemented, and “bringing order” raises numerous questions. This paper discusses justifications and goals for establishing space traffic management, triggers which might move the concept forward, current plans for piloting aspects for space traffic management, and questions that must be answered. The paper argues that effective space traffic management will become a reality when one of two things happens: a collision involving a major space asset, or interest by commercial satellite operators in such a service to protect their assets from collision. The paper includes a discussion of the likelihood of collision and how cost-effectiveness might be interpreted.
Clinical value of anorectal manometry index in neurogenic fecal incontinence.

PURPOSE: The present communication is an endeavor to assess the value of a simple motility index to separate patients with neurogenic or idiopathic fecal incontinence from those patients with the secondary form of the disease. METHODS: Study population consisted of 23 patients with idiopathic fecal incontinence and 13 patients with fecal incontinence secondary to surgical or obstetric trauma. They all had a standard anorectal manometric study after a 12-hour fast. A motility index was then prepared taking into consideration the peak sphincter pressure values, contractility endurance, and rectal sensory threshold. RESULTS: Despite differences in the mean peak squeeze pressure and sensory threshold between the two groups, there were significant overlaps for all parameters of standard anorectal manometry in both groups. However, patients with idiopathic incontinence had an index of smaller than 28, and the group with the secondary form of incontinence had indexes higher than 30. CONCLUSIONS: 1) None of the four parameters of a conventional anorectal manometry can accurately separate patients with neurogenic incontinence from those with secondary forms of the disorder. 2) The anorectal motility index presented here can accurately separate the two groups. 3) This index is superior to the standard anorectal manometry in evaluating patients with fecal incontinence.
Manufacturing technology centers as components of regional technology infrastructures

Abstract In this paper the intent, content, and unresolved design issues of manufacturing modernization centers are described. These centers are then viewed through theories of regional technology infrastructure in order to (1) use such theories to identify relationships that can be expected to affect the effectiveness and efficiency of these new programs; and (2) use their workings as a means of operationalizing and testing the at-times global, amorphous content of these theories. A critique of the forms of market failure is offered. The purpose here is to identify a research agenda and mark the limits of current theories of regional technology infrastructure as a guide to policy formulation. Despite few summative evaluations of manufacturing modernization programs, sufficient firm-specific accounts exist to indicate that these programs can contribute to the competitiveness of small and medium-sized manufacturing firms, and that they have considerable potential. Manufacturing technology centers need to be more carefully examined, both in terms of formal program evaluations and as components of a region's technology infrastructure.
Computing periodic orbits using the anti-integrable limit

Abstract Chaotic dynamics can be effectively studied by continuation from an anti-integrable limit. Using the Henon map as an example, we obtain a simple analytical bound on the domain of existence of the horseshoe that is equivalent to the well-known bound of Devaney and Nitecki. We also reformulate the popular method for finding periodic orbits introduced by Biham and Wenzel. Near an anti-integrable limit, we show that this method is guaranteed to converge. This formulation puts the choice of symbolic dynamics, required for the algorithm, on a firm foundation.
Recent X-ray observations of supernova remnants.

The imaging and spectral capabilities of the Chandra X-ray Observatory and XMMNewton are extremely well suited for studying the remnants of supernovae. Highresolution imaging over the band 0.1–10 keV maps the detailed structure of the supernova remnant, delineates the forward and reverse shock fronts and facilitates proper motion studies of the expanding material. High-resolution spectroscopy enables detailed diagnostics of the emitting plasma, including temperatures, ionization balance and abundances. Spectroscopy also reveals Doppler velocities along the line of sight. Most powerful is the capability for imaging spectroscopy, which can probe the progressive ionization at the shock fronts, the elemental distribution in the ejecta, and Doppler imaging. Examples are drawn from recent studies of oxygen-rich supernova remnants of various ages.
Finite element differential forms on cubical meshes

We develop a family of finite element spaces of differential forms defined on cubical meshes in any number of dimensions. The family contains elements of all polynomial degrees and all form degrees. In two dimensions, these include the serendipity finite elements and the rectangular BDM elements. In three dimensions they include a recent generalization of the serendipity spaces, and new H(curl) and H(div) finite element spaces. Spaces in the family can be combined to give finite element subcomplexes of the de Rham complex which satisfy the basic hypotheses of the finite element exterior calculus, and hence can be used for stable discretization of a variety of problems. The construction and properties of the spaces are established in a uniform manner using finite element exterior calculus.
Statistics of Sunyaev—Zel'dovich cluster surveys

We describe a detailed analytic model for predicting statistical quantities (such as number counts, redshift distributions and sizes) of clusters detected in blank-field, thermal Sunyaev–Zel'dovich effect experiments. We include in this model the possibility of non-Gaussian density perturbations in the early Universe and also describe a simple model for the effects of preheating on cluster Sunyaev–Zel'dovich effect fluxes. We use this model to explore the current state of the theoretical uncertainties present in this type of analytic modelling, highlighting where further improvement will be necessary to exploit forthcoming surveys fully. We then go on to explore the constraints on cosmological parameters, the presence of any non-Gaussianity and the degree of cluster preheating that may be obtained from both the Bolocam and Planck experiments. We find that, providing redshifts can be measured for all detected clusters, the Bolocam experiment may provide detections of non-Gaussianity or preheating and could give approximate measurements of these effects if prior knowledge of the various cosmological parameters is taken into account. The Planck experiment Sunyaev–Zel'dovich effect cluster survey is predicted to provide highly accurate (∼5 per cent) measurements of the degree of non-Gaussianity and preheating while also providing measurements of several cosmological parameters to accuracies of a few per cent independently of those constraints that will be derived from its detections of primordial cosmic microwave background anisotropies.
Analytic formulae for the effective conductivity of a square or hexagonal array of parallel tubes

Abstract A set of analytic formulae are presented for the effective thermal conductivity of either a square or a hexagonal array of parallel tubes which have distinct core, tube and fill conductivities. The formulae are based on a generalization of Rayleigh's [Phil. Mag. 34(5), 481–502 (1892)] method to include hexagonal (as well as square) arrays, tubes (as well as solid rods), and higher-order terms in the analytic series. The accuracy of the analytic formulae is determined by comparison with essentially exact numerical calculations. The formulae are applied to the problem of an array of dry, spent, nuclear fuel rods.
On the mass and width of the Z-boson and other relativistic quasistable particles

Abstract The ambiguity in the definition for the mass and width of relativistic resonances is discussed, in particular for the case of the Z -boson. This ambiguity can be removed by requiring that a resonance's width Γ (defined by a Breit–Wigner lineshape) and lifetime τ (defined by the exponential law) always and exactly fulfill the relation Γ=ℏ/τ . To justify this, one needs relativistic Gamow vectors which in turn define the resonance's mass M R as the real part of the square root Re s R of the S -matrix pole position s R . For the Z -boson this means that M R ≈M Z −26 MeV and Γ R ≈Γ Z −1.2 MeV where M Z and Γ Z are the values reported in the particle data tables.
Measurement of digital particle image velocimetry precision using electro-optically created particle-image displacements

The displacement (velocity) precision achieved with digital particle image velocimetry (PIV) was measured. The purpose of this work was to determine the precision and sensitivity of digital PIV using real rather than theoretical images at 1 and 2 mm spatial resolution. The displacement measurement precision was determined by measuring the RMS noise from 60 identical displacement distributions. This work is unique in that it uses electro-optical image shifting to create a repeatable image displacement distribution of random particle fields. The displacement variance between images is caused by the shot-to-shot variation in: (1) the particle-image fields, (2) the camera noise and (3) the variance in the correlation peak detection. In addition to magnification variations, the particle-number density, imaging-lens f-stop and image-plane position errors were varied to determine the best configuration. The results indicate that both the ensemble-mean and the RMS fluctuations of the image displacements are affected by these parameters and comparisons with results found in the literature are presented. The extents of these variations are quantified. This variance does not, of course, include errors due to random gradients and out-of-plane pairing losses, which exist in real turbulent flows.
Cardiovascular health and economic effects of smoke-free workplaces

Abstract Purpose Smoking is the leading controllable risk factor for heart disease. Only about 69% of U.S. indoor workers are currently covered by a smoke-free workplace policy. This analysis projects the cardiovascular health and economic effects of making all U.S. workplaces smoke free after 1 year and at steady state. Methods We estimated the number of U.S. indoor workers not covered by smoke-free workplace policies, and the effects of making all workplaces smoke free on smoking behavior and on the relative risks of acute myocardial infarctions and strokes. One-year and steady-state results were calculated using an exponential decline model. A Monte Carlo simulation was performed for a sensitivity analysis. Results The first-year effect of making all workplaces smoke free would produce about 1.3 million new quitters and prevent over 950 million cigarette packs from being smoked annually, worth about $2.3 billion in pretax sales to the tobacco industry. In 1 year, making all workplaces smoke free would prevent about 1500 myocardial infarctions and 350 strokes, and result in nearly $49 million in savings in direct medical costs. At steady state, 6250 myocardial infarctions and 1270 strokes would be prevented, and $224 million would be saved in direct medical costs annually. Reductions in passive smoking would account for 60% of effects among acute myocardial infarctions. Conclusion Making all U.S. workplaces smoke free would result in considerable health and economic benefits within 1 year. Reductions in passive smoking would account for a majority of these savings. Similar effects would occur with enactment of state or local smoke-free policies.
Riemannian manifolds with maximal eigenfunction growth

On any compact Riemannian manifold $(M, g)$ of dimension $n$, the $L\sp 2$-normalized eigenfunctions $\{\phi\sb \lambda\}$ satisfy $\lvert \rvert\phi\sb \lambda\lvert \rvert\sb\infty\leq C\lambda\sp {(n-1)/2}$, where $-\Delta\phi\sb \lambda=\lambda\sp 2\phi\sb \lambda$. The bound is sharp in the class of all $(M, g)$ since it is obtained by zonal spherical harmonics on the standard $n$-sphere $S\sp n$. But, of course, it is not sharp for many Riemannian manifolds, for example, for flat tori $\mathbb {R}\sp n/\Gamma$. We say that $S\sp n$, but not $\mathbb {R}\sp n/\Gamma$, is a Riemannian manifold with maximal eigenfunction growth. The problem that motivates this paper is to determine the $(M, g)$ with maximal eigenfunction growth. Our main result is that such an $(M, g)$ must have a point $x$ where the set $\mathscr {L}\sb x$ of geodesic loops at $x$ has positive measure in $S\sp \ast\sb xM$. We show that if $(M, g)$ is real analytic, this puts topological restrictions on $M$; for example, only $M=S\sp 2$ or $M=\mathbb {R}P\sp 2$ (topologically) in dimension $2$ can possess a real analytic metric of maximal eigenfunction growth. We further show that generic metrics on any $M$ fail to have maximal eigenfunction growth. In addition, we construct an example of $(M, g)$ for which $\mathscr {L}\sb x$ has positive measure for an open set of $x$ but which does not have maximal eigenfunction growth; thus, it disproves a naive converse to the main result.
Simulated orbiter lift-off acceleration - A stochastic model

Abstract A simple procedure for generating synthetic orbiter lift-off acceleration is described. This stochastic method is based on a filtered white noise model which accounts for the nonstationary time evolution of amplitude and frequency content of orbiter lift-off accelerations. The example of Space Transportation System STS-41 Z-acceleration is carefully examined, and the corresponding synthetic orbiter lift-off accelerations model was developed. It is shown that the resulting simulated accelerations preserve significant properties of the original record. Statistically based acceleration response spectra curves for the simulated orbiter lift-off excitations are also evaluated and the results are compared with those for the actual flight data.
The Fredholm index of a pair of commuting operators

This paper concerns Fredholm theory in several variables, and its applications to Hilbert spaces of analytic functions. One feature is the introduction of ideas from commutative algebra to operator theory. Specifically, we introduce a method to calculate the Fredholm index of a pair of commuting operators. To achieve this, we define and study the Hilbert space analogs of Samuel multiplicities in commutative algebra. Then the theory is applied to the symmetric Fock space. In particular, our results imply a satisfactory answer to Arveson’s program on developing a Fredholm theory for pure d-contractions when d = 2, including both the Fredholmness problem and the calculation of indices. We also show that Arveson’s curvature invariant is in fact always equal to the Samuel multiplicity for an arbitrary pure d-contraction with finite defect rank. It follows that the curvature is a similarity invariant.
Compression by indexing: an improvement over MPEG-4 body animation parameter compression

Body Animation Parameters (BAPs) are used to animate MPEG-4 compliant virtual human-like characters. In order to stream BAPs in real time interactive environments, the BAPs are compressed for low bitrate representation using a standard MPEG-4 compression pipeline. However, the standard MPEG-4 compression is inefficient for streaming to power-constrained devices, since the streamed data requires extra power in terms of CPU cycles for decompression. In this paper, we have proposed and implemented an indexing technique for a BAP data stream, resulting in a compressed representation of the motion data. The resulting compressed representation of the BAPs is 1 superior to the MPEG-4-based BAP compression in terms of both, required network throughput and power consumption at the client end to receive the compressed data stream and extract the original BAP data from the compressed representation. Although the resulting motion after de-compression at the client end is lossy, the motion distortion is minimized by intelligent use of the hierarchical structure of the skeletal avatar model. Consequently, the proposed indexing method is ideal for streaming of motion data to power- and network-constrained devices such as PDAs, Pocket PCs and Laptop PCs operating in battery mode and other devices in a mobile network environment.
Surface tension in incompressible Rayleigh–Taylor mixing flow

We study the effect of surface tension on the incompressible Rayleigh–Taylor instability. We modify Goncharov's local analysis [1] to consider the surface tension effect on the Rayleigh–Taylor bubble velocity. The surface tension damps the linear instability and reduces the nonlinear terminal bubble velocity. We summarize the development of a finite-volume, particle-level-set, two-phase flow solver with an adaptive Cartesian mesh, and results from convergence and validation studies of this two-phase flow solver are provided. We use this code to simulate the single-mode, viscous Rayleigh–Taylor instability with surface tension, and good agreement in terminal bubble velocity is found when compared with analytic results. We also simulate the immiscible Rayleigh–Taylor instability with random initial perturbations. The ensuing mixing flow is characterized by the effective mixing rate and the flow anisotropy. Surface tension tends to reduce the effective mixing rate and homogenizes the Rayleigh–Taylor mixing f...
Following Knots down Their Energy Gradients

This paper details a series of experiments in searching for minimal energy configurations for knots and links using the computer program KnotPlot.
How to Tell a Jet from a Balloon: A Proposed Test for Beaming in Gamma-Ray Bursts

If gamma-ray bursts are highly collimated, radiating into only a small fraction of the sky, the energy requirements of each event may be reduced by several (~4-6) orders of magnitude, and the event rate is increased correspondingly. Extreme conditions in gamma-ray bursters lead to highly relativistic motions (bulk Lorentz factors of ? 100). This results in strong forward beaming of the emitted radiation in the observer's rest frame. Thus, all information on gamma-ray bursts comes from those ejecta emitted in a narrow cone (opening angle of ~1/?) pointing toward the observer. We are at present ignorant of whether there are ejecta outside that cone or not. The recent detection of longer wavelength transients following gamma-ray bursts allows an empirical test of whether gamma-ray bursts are well-collimated jets or spherical fireballs. The bulk Lorentz factor of the burst ejecta will decrease with time after the event, as the ejecta sweep up the surrounding medium. Thus, radiation from the ejecta is beamed into an ever-increasing solid angle as the burst remnant evolves. It follows that if gamma-ray bursts are highly collimated, many more optical and radio transients should be observed without associated gamma rays than with them. Published supernova searches may contain enough data to test the most extreme models of gamma-ray beaming. We close with a brief discussion of other possible consequences of beaming, including its effect on the evolution of burst remnants.
Dynamics of Output and Employment in the U.S. Economy

This paper investigates the changing relationship between employment and real output in the U.S. economy from 1948 to 2010 both at the aggregate level and at some major industry-grouping levels of disaggregation. Real output is conventionally measured as value added corrected for price ination, but there are some industries in which no independent measure of value added is possible and existing statistics depend on imputing value added to equal income. Indexes of output that exclude these imputations are closely correlated with employment over the whole period, and remain more closely correlated during the current business cycle. This analysis oers insights into deeper
Anti- Ω : the weakest failure detector for set agreement

In the set agreement problem, n processes have to decide on at most n − 1 of the proposed values. This paper considers asynchronous shared-memory systems equipped with an anti-Ω failure detector. Each query to the anti-Ω returns a process id; the specification ensures that there is a correct process whose id is returned only finitely many times. The main result is that anti-Ω is both necessary and sufficient to solve set agreement in the asynchronous shared memory model.
The Frobenius Complex

Motivated by the classical Frobenius problem, we introduce the Frobenius poset on the integers \({\mathbb Z}\) , that is, for a sub-semigroup Λ of the non-negative integers (\({\mathbb N}\) , +), we define the order by n ≤Λm if \({{m-n \in \Lambda}}\). When Λ is generated by two relatively prime integers a and b, we show that the order complex of an interval in the Frobenius poset is either contractible or homotopy equivalent to a sphere. We also show that when Λ is generated by the integers {a, a + d, a + 2d, . . . , a + (a−1)d}, the order complex is homotopy equivalent to a wedge of spheres.
Social Relationships, Gender, and Recovery From Mobility Limitation Among Older Americans

Objectives. Evidence suggests social relationships may be important facilitators for recovery from functional impairment, but the extant literature is limited in its measurement of social relationships including an over emphasis on filial social support and a paucity of nationally representative data.
Cyclopropanone equivalents from 3-chloropropionic acid. Use of 1-piperidino-1-trimethylsilyloxycyclopropane in synthetic applications

Abstract 1-Piperidino-1-trimethylsilyloxycyclopropane and the corresponding 1-hydroxy-1-piperidinocyclopropane, conveniently prepared from the piperidide of 3-chloropropionic acid, react as cyclopropanone equivalents with various nucleophiles. Use of these derivatives in the formation of pyrroles, pyrrolines and pyrrolizidines is described. The rearrangement of dicyclopropyl ketimines is explored.
Swiss Exchange Rate Policy in the 1930s. Was the Delay in Devaluation Too High a Price to Pay for Conservatism

In this paper we examine the experience of Switzerland’s devaluation in 1936. We ask the following questions: what were the issues at stake in the political debate? What was the cost to Switzerland of the delay in the franc devaluation? What would have been the costs and benefits of an earlier exchange rate policy? To answer these questions we construct a simple open economy macro model of the interwar Swiss economy. We then posit counterfactual scenarios of alternative exchange rate pegs in 1931 and 1933. Our simulations clearly show a significant and large increase in real economic activity.
Optimal time to change premiums

The claim arrival process to an insurance company is modeled by a compound Poisson process whose intensity and/or jump size distribution changes at an unobservable time with a known distribution. It is in the insurance company’s interest to detect the change time as soon as possible in order to re-evaluate a new fair value for premiums to keep its profit level the same. This is equivalent to a problem in which the intensity and the jump size change at the same time but the intensity changes to a random variable with a know distribution. This problem becomes an optimal stopping problem for a Markovian sufficient statistic. Here, a special case of this problem is solved, in which the rate of the arrivals moves up to one of two possible values, and the Markovian sufficient statistic is two-dimensional.
Density functional band gaps of AlAs

We present results of ab initio, self-consistent calculations of electronic properties of AlAs in the zinc-blende structure. Our nonrelativistic calculations employed the generalized gradient approximation of density functional potential and Bagayoko, Zhao, and Williams implementation method of the linear combination of atomic orbitals formalism. Our calculated indirect band gaps at the $X$ and $L$ points are 2.15 and $2.38\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$, respectively, in good agreement with experimental values. The calculated direct gap at $\ensuremath{\Gamma}$ is 25% smaller than the experimental one. We also present calculated total and partial densities of states and the electron effective mass at the bottom of the conduction band at $\ensuremath{\Gamma}$.
Specular ray parameter extraction and stationary‐phase migration

The Kirchhoff-type prestack depth migration operator is a diffraction stack of seismic reflection energies over seismic traces. Typically, the diffraction stack is carried out over the full data aperture, producing not only images of reflectors but also aliasing artifacts. Aliasing artifacts often break reflector continuity in images. The stationary-phase approximation to the migration operator shows that, for image points on reflectors, traces within the neighborhood of specular rays contribute most to the diffraction stack. Traces outside this vicinity introduce aliasing artifacts into the image, especially in the case of coarse trace spacing and aperture truncation. A new migration algorithm, denoted as stationary-phase migration, is proposed to find the specular ray parameters and then to migrate the specular-ray energies and reject nonspecular ray energies to yield images with less aliasing.
Climate effects on atmospheric carbon dioxide over the last century

The buildup of atmospheric CO 2 since 1958 is surprisingly well explained by the simple premise that 57% of the industrial emissions (fossil fuel burning and cement manufacture) has remained airborne. This premise accounts well for the rise both before and after 1980 despite a decrease in the growth rate of fossil fuel CO 2 emissions, which occurred at that time, and by itself should have caused the airborne fraction to decrease. In contrast, the buildup prior to 1958 was not simply proportional to cumulative fossil fuel emissions, and notably included a period during the 1940s when CO 2 growth stalled despite continued fossil fuel emissions. Here we show that the constancy of the airborne fraction since 1958 can be in part explained by decadal variations in global land air temperature, which caused a warming-induced release of CO 2 from the land biosphere to the atmosphere. We also show that the 1940s plateau may be related to these decadal temperature variations. Furthermore, we show that there is a close connection between the phenomenology producing CO 2 variability on multidecadal and El Nino timescales. DOI: 10.1111/j.1600-0889.2009.00439.x
Chandra data archive operations: lessons learned

We present a discussion of the lessons learned from establishing and operating the Chandra Data Archive (CDA). We offer an overview of the archive, what preparations were done before launch, the transition to operations, actual operations, and some of the unexpected developments that had to be addressed in running the archive. From this experience we highlight some of the important issues that need to be addressed in the creation and running of an archive for a major project. Among these are the importance of data format standards; the integration of the archive with the rest of the mission; requirements throughout all phases of the mission; operational requirements; what to expect at launch; the user interfaces; how to anticipate new tasks; and overall importance of team management and organization.
Towards a Smart Experimental Arena for Long-Term Electrophysiology Experiments

Wireless power and data transmission have created promising prospects in biomedical research by enabling perpetual data acquisition and stimulation systems. We present a work in progress towards such a system, called the EnerCage, equipped with scalable arrays of overlapping planar spiral coils (PSC) and 3-axis magnetic sensors for focused wireless power transmission to randomly moving targets, such as small freely behaving animal subjects. The EnerCage system includes a stationary unit for 3D non-line-of-sight localization and inductive power transmission through a geometrically optimized PSC array. The localization algorithm compares the magnetic sensor outputs with a threshold to activate a PSC. All PSCs are optimized based on the worst-case misalignment, considering parasitics from the overlapping and adjacent PSCs. EnerCage also has a mobile unit attached to or implanted in the subject's body, which includes a permanent magnetic tracer for localization and back telemetry circuit for efficient closed-loop inductive power regulation. The EnerCage system is designed to enable long-term electrophysiology experiments on freely behaving small animal subjects in large experimental arenas without requiring them to carry bulky batteries. A prototype of the EnerCage system with five PSCs and five magnetic sensors achieved power transfer efficiency (PTE) of 19.6% at the worst-case horizontal misalignment of 49.1 mm (√1/3 of the PSC radius) and coupling distance of 78 mm with a mobile unit coil, 20 mm in radius. The closed-loop power management mechanism maintains the mobile unit received power at 20 mW despite misalignments, tilting, and distance variations up to a maximum operating height of 120 mm (PTE=5%).
Optimum Design of Forging Die Shapes Using Nonlinear Finite Element Analysis

An optimization method is developed for the design of intermediate die shapes needed in the plane strain and axisymmetric forging operations. The approach is based on backward deformation simulation using nonlinear rigid viscoplastic finite element method and shape optimization techniques. The advantage of this optimization approach is that it has the ability to determine the intermediate die shapes from the final product shape by applying constraints on the plastic deformation of the material. This paper presents axisymmetric disk and plane strain case studies to demonstrate the new design procedures for minimizing variations in deformation rates during a multistage forging operation
Controlled growth of monodisperse self-supported superparamagnetic nanostructures of spherical and rod-like CoFe2O4 nanocrystals.

Novel shape- and structural-controlled superparamagnetic nanostructures composed of self-supported spherical and rod-like CoFe2O4 colloidal nanocrystals have been prepared by thermolysis of a stoichiometric Co2+Fe23+−oleate complex in organic solution with periodic injection of hexane for controlling the nucleation, assembly, and growth of the nuclei.
Believing change and changing belief

We present a first-order logic of time, chance, and probability that is capable of expressing the four types of higher-order probability sentences relating subjective probability and objective chance at different times. We define a causal notion of objective chance and show how it can be used in conjunction with subjective probability to distinguish between causal and evidential correlation by distinguishing between conditions, events, and actions that: 1) influence the agent's belief in chance; and 2) the agent believes to influence chance. Furthermore, the semantics of the logic captures some common sense inferences concerning objective chance and causality. We show that an agent's subjective probability is the expected value of its beliefs concerning objective chance. We also prove that an agent using this representation believes with certainty that the past cannot be causally influenced.
Space Shuttle externally induced environment compared with Skylab's natural environment

Electret measurements obtained of the particulate contamination environment within the Space Shuttle Orbiter's cargo bay are presently compared with ground measurements of the particulates emitted by the Shuttle's SRBs, as well as with the expected natural particulate environment as measured by Skylab. Chemical analysis is shown to reveal the difference between natural and anthropogenic space debris; the most probable primary source of the Space Shuttle's particulate environment is the SRB exhaust.
Network Analysis of Breast Cancer Progression and Reversal Using a Tree-Evolving Network Algorithm

The HMT3522 progression series of human breast cells have been used to discover how tissue architecture, microenvironment and signaling molecules affect breast cell growth and behaviors. However, much remains to be elucidated about malignant and phenotypic reversion behaviors of the HMT3522-T4-2 cells of this series. We employed a “pan-cell-state” strategy, and analyzed jointly microarray profiles obtained from different state-specific cell populations from this progression and reversion model of the breast cells using a tree-lineage multi-network inference algorithm, Treegl. We found that different breast cell states contain distinct gene networks. The network specific to non-malignant HMT3522-S1 cells is dominated by genes involved in normal processes, whereas the T4-2-specific network is enriched with cancer-related genes. The networks specific to various conditions of the reverted T4-2 cells are enriched with pathways suggestive of compensatory effects, consistent with clinical data showing patient resistance to anticancer drugs. We validated the findings using an external dataset, and showed that aberrant expression values of certain hubs in the identified networks are associated with poor clinical outcomes. Thus, analysis of various reversion conditions (including non-reverted) of HMT3522 cells using Treegl can be a good model system to study drug effects on breast cancer.
A one-pot three-component reaction for the preparation of highly functionalized tryptamines

Abstract We have developed a general one-pot method to provide highly functionalized tryptamine derivatives, via a Fischer indole type pathway. In this article, we demonstrate optimal conditions for a one-pot indole synthesis, allowing for the synthesis of a broad scope of 2-methyl tryptamine derivatives and a precursor for the synthesis of the core structure of some akuammiline alkaloids. Additionally, further modification of the indole products is described.
Reaction kinetics of phase formation in Nb-Al powder metallurgy processed wire

The sequence of phases formed in the low-temperature reaction of niobium and aluminium to form the A15 superconductor, Nb/sub 3/Al, was studied in high areal reduction powder metallurgy processed wire samples. The reaction path observed was the same as that reported previously for multilayer Nb/Al thin films. The reaction proceeds without the formation of the sigma phase, Nb/sub 2/Al resulting in a metastable A15 of higher Al concentration. The extent of this metastable extension is estimated to be 22-24 at.% Al, based on the resistive T/sub c/ of 17.0 K observed. The reaction kinetics of the wire samples were examined by scanning heat flux calorimetry, and the activation energy of A15 formation was found to be 3.1 eV. The formation of NbAl/sub 3/ and dissolution of Al into the Nb lattice were both observed as precursor reactions with much lower activation energies. >
Frequency Correlation of QPOs Based on a Resonantly Excited Disk-Oscillation Model

In previous papers, we have proposed a model that the high-frequency quasi-periodic oscillations (HF QPOs) observed in black-hole and neutron-star X-ray binaries are inertial-acoustic oscillations that are resonantly excited on a one-armed deformed disk by nonlinear couplings between the oscillations and the disk deformation. In this paper we show that in addition to the inertial-acoustic waves, one-armed corrugation waves are also excited in the deformed disks. They are low-frequency oscillations. We examine frequencies and their correlations among the inertial-acoustic oscillations and the corrugation waves that are excited, in order to know whether they can describe observed frequency correlations among kHz QPOs and low-frequency QPOs (LF QPOs) in neutron-star X-ray binaries. The results seem to well describe the observed correlations in Cir X-1, if we adopt $M= 1.5\sim 2.0 M_\odot$ and $a_* \sim 0.8$, where $M$ is the mass of the central star and $a_*$ is the dimensionless spin parameter of the metric. Finally, assumptions involved in this disk-oscillation model are briefly summarized and discussed.
The effects of geometry and dielectric material on stripline and microstrip internal temperatures

The geometry and loss characteristics of 50-/spl Omega/ striplines operating at a frequency of 1.09GHz, which corresponded to the requirements for an existing military radio system, were estimated using fundamental transmission line theory. These results were then combined with finite element based thermal modeling to estimate the temperature rise within a stripline. The finite element thermal predictions were validated with measurements on a circuit board used in an avionics power amplifier. The results of this analysis showed that higher dielectric materials allow for smaller geometries but have higher power loss compared to traditional lower dielectric materials. While the striplines produced with higher dielectric materials have more power loss (thermal dissipation), their internal temperature rise is comparable to that of striplines produced on lower dielectric materials. This is due to the fact that the higher dielectric materials also tend to have higher thermal conductivity. Thermal testing and analysis indicate that, while the approach was based on a stripline with characteristic impedance of 50/spl Omega/ and a frequency of 1.09GHz, the thermal analysis that was developed is applicable to both striplines and microstrips of any impedance or frequency.
STUDIES ON THE LIFTOFF PROPERTIES OF DIMETHYL ETHER JET DIFFUSION FLAMES

The liftoff properties of the DME jet diffusion flame were investigated experimentally and analytically with Emphasis on the influences of flame stretch and fuel oxygen. The present experiments showed that the DME jet diffusion flame exhibited a distinct liftoff phenomenon that differed from other hydrocarbon fuels. This unique phenomenon was analyzed theoretically by taking into consideration the effects of flame stretch and the fuel oxygen. The results showed that the stretch effect had a significant impact on the critical liftoff Schmidt number and the flame liftoff height. Based on these observations, a new criterion for the lifted flame at the blowout limit was presented. The results also demonstrated that the appearance of fuel oxygen in DME increases the fuel mixture fraction at the stoichiometric condition and changes the flame liftoff phenomenon. The effect of fuel oxygen was further investigated by adding air into propane and n-butane diffusion flames. It was found that with the increase of oxyg...
EXPLORING DECISION STRATEGIES AND EVALUATIONS OF PERFORMANCE BY NETWORKED AND NON-NETWORKED SMALL U.S. BUSINESSES

A strategic network perspective established the theoretical foundation for exploring aspects of business management in 383 small businesses predominantly operating in small communities across the U.S. It was proposed that those owner/managers involved in formal voluntary organizations to promote business effectiveness would differ in their strategic decisions and evaluations of performance from businesses without such formal group affiliations. Business strategies assessed involved the emphasis placed on employees, customers, and community, and the effect of these three variables in explaining four elements of business performance. Networking businesses were found to place more emphasis on strategies dealing with employees, customers, and community than non-networking businesses. Final results suggested that network membership held a direct effect on business strategies, and that these strategies held varying direct effects on perceptions of business performance. Findings offer initial support for strategic network theory as well as practical information for small business owners considering network membership.
Full-zone spin splitting for electrons and holes in bulk GaAs and GaSb.

The spin-orbit interaction---a fundamental electroweak force---is equivalent to an effective magnetic field intrinsic to crystals, leading to band spin splitting for certain $k$ points in sufficiently low-symmetry structures. This (Dresselhaus) splitting has usually been calculated at restricted regions in the Brillouin zone via small wave vector approximations (e.g., $\mathbf{k}\ifmmode\cdot\else\textperiodcentered\fi{}\mathbf{p}$), potentially missing the ``big picture.'' We provide a full-zone description of the Dresselhaus splitting in zinc blende semiconductors by using pseudopotentials, empirically corrected to rectify local density approximation errors by fitting $GW$ results. In contrast to what was previous thought, we find that the largest spin splitting in the lowest conduction band and upper valence band (VB1) occurs surprisingly along the (210) direction, not the (110) direction, and that the splitting of the VB1 is comparable to that of the next two valence bands VB2 and VB3.