cssi/SciSciGPT-SciSciNet huggingface dataset:
Theoretical studies of shock-initiated detonations

Abstract The dynamics of shock propagation have been studied theoretically for a variety of two-dimensional lattices. The approach used is based on molecular dynamics and hinges on the exact numerical solution by computer of the equations of motion for the individual atoms or molecules in each lattice. Shocks have been launched into the lattices under study by methods designed to simulate flyer-plate impact. Two different interatomic potentials have been used, one endothermic and one net-exothermic. For both types of potential, a shock launched at one side of the lattice will spall a group of atoms off the other side. However, the subsequent behavior of the two types of lattice is very different. For endothermic potentials, after the initial atomic spall, the residual lattice is quiescent with little further activity. For net-exothermic potentials, the initial atomic spall injects additional energy into the system in such a manner that subsequently further spall occurs at both sides. Once this new spall is initiated, it leads rapidly to further bond breaking and explosive disintegration of the system.
Managing the Grading Paradox: Leveraging the Power of Choice in the Classroom

How can management educators cultivate students' interest in the MBA classroom? Inspiring interest, an important antecedent of learning, can be an uphill battle due to the ubiquitous presence of grades. Grades are meant to encourage interest, yet they often do just the opposite. The result is a grading paradox. We hypothesize that leveraging choice in the classroom can manage this grading paradox by increasing interest. In a field experiment in real-world MBA classrooms (N = 91 students), we found that a choice intervention, the opportunity for students to allocate the weight of several course components toward their final course grade, was associated with higher levels of two types of interest, triggered situational interest and maintained situational interest. This study corroborates and extends previous laboratory-based research documenting the positive relationship between choice and interest, and offers a practical tool that management educators can use to encourage student interest.
Riemann-Hilbert approach to gap probabilities for the Bessel process

Nous considerons la probabilite de "gap" pour le processus de Bessel dans le cas sans temp et le cas multi-temps. Nous montrons que les determinants de Fredholm de ce processus peuvent etre exprimees en termes de determinants de noyaux integrables dans le sens de Its-Izergin-Korepin-Slavnov et donc lies a des problemes appropries de Riemann-Hilbert. Dans le cas sans temp, nous construisons une paire de Lax et nous derivons un equation de Painleve III lies au determinant de Fredholm.
Adaptation and regulation with signal detection implies internal model

Abstract This note provides a simple result showing, under suitable technical assumptions, that if a system Σ adapts to a class of external signals U , in the sense of regulation against disturbances or tracking signals in U , then Σ must necessarily contain a subsystem which is capable of generating all the signals in U . It is not assumed that regulation is robust, nor is there a prior requirement for the system to be partitioned into separate plant and controller components. Instead, one assumes that a “signal detection” property holds.
Are all static black hole solutions spherically symmetric

The static black hole solutions to the Einstein-Maxwell equations are all spherically symmetric, as are many of the recently discovered black hole solutions in theories of gravity coupled to other forms of matter. However, counterexamples demonstrating that static black holes need not be spherically symmetric exist in theories, such as the standard electroweak model, with electrically charged massive vector fields. In such theories, a magnetically charged Reissner-Nordstrom solution with sufficiently small horizon radius is unstable against the development of a nonzero vector field outside the horizon. General arguments show that, for generic values of the magnetic charge, this field cannot be spherically symmetric. Explicit construction of the solution shows that it in fact has no rotational symmetry at all.
A no-go theorem for matter-wave interferometry with application to the neutron's electric-dipole moment

Abstract A general theorem for matter-wave interferometry that relies only on the unitary property of the Schroedinger equation and not upon any classical or semi-classical approximation restricts the benefits of using long drift spaces. In particular, it negates some, but not all, suggestions that have been made for measuring the neutron's electric-dipole moment by interferometry.
On properties of Parisi measures

We investigate the structure of Parisi measures, the functional order parameters of mixed \(p\)-spin models in mean field spin glasses. In the absence of external field, we prove that a Parisi measure satisfies the following properties. First, at all temperatures, the support of any Parisi measure contains the origin. If it contains an open interval, then the measure has a smooth density on this interval. Next, we give a criterion on temperature parameters for which a Parisi measure is neither Replica Symmetric nor One Replica Symmetry Breaking. Finally, we show that in the Sherrington–Kirkpatrick model, slightly above the critical temperature, the largest number in the support of a Parisi measure is a jump discontinuity. An analogue of these results is discussed in the spherical mixed \(p\)-spin models. As a tool to establish these facts and of independent interest, we study functionals of the associated Parisi PDEs and derive regularity properties of their solutions.
Genetic Algorithms as an Approach to Configuration and Topology Design

The genetic algorithm, a search and optimization technique based on the theory of natural selection, is applied to problems of structural topology design. An overview of the genetic algorithm will first describe the genetics-based representations and operators used in a typical genetic algorithm search. Then, a review of previous research in structural optimization is provided. A discretized design representation, and methods for mapping genetic algorithm “chromosomes” into this representation, is then detailed. Several examples of genetic algorithm-based structural topology optimization are provided: we address the optimization of cantilevered plate topologies, and we investigate methods for optimizing finely-discretized design domains. The genetic algorithm’s ability to find families of highly-fit designs is also examined. Finally, a description of potential future work in genetic algorithm-based structural topology optimization is offered.
Magnetohydrodynamic Augmented Propulsion Experiment

A fundamental obstacle to routine space access is the specific energy limitations associated with chemical fuels. In the case of vertical take-off, the high thrust needed for vertical liftoff and acceleration to orbit translates into power levels in the 10 GW range. Furthermore, useful payload mass fractions are possible only if the exhaust particle energy (i.e., exhaust velocity) is much greater than that available with traditional chemical propulsion. The electronic binding energy released by the best chemical reactions (e.g., LOX/LH2 for example, is less than 2 eV per product molecule (approx. 1.8 eV per H2O molecule), which translates into particle velocities less than 5 km/s. Useful payload fractions, however, will require exhaust velocities exceeding 15 km/s (i.e., particle energies greater than 20 eV). As an added challenge, the envisioned hypothetical RLV (reusable launch vehicle) should accomplish these amazing performance feats while providing relatively low acceleration levels to orbit (2-3g maximum). From such fundamental considerations, it is painfully obvious that planned and current RLV solutions based on chemical fuels alone represent only a temporary solution and can only result in minor gains, at best. What is truly needed is a revolutionary approach that will dramatically reduce the amount of fuel and size of the launch vehicle. This implies the need for new compact high-power energy sources as well as advanced accelerator technologies for increasing engine exhaust velocity. Electromagnetic acceleration techniques are of immense interest since they can be used to circumvent the thermal limits associated with conventional propulsion systems. This paper describes the Magnetohydrodynamic Augmented Propulsion Experiment (MAPX) being undertaken at NASA Marshall Space Flight Center (MSFC). In this experiment, a 1-MW arc heater is being used as a feeder for a 1-MW magnetohydrodynamic (MHD) accelerator. The purpose of the experiment is to demonstrate that an MHD accelerator can be an effective augmentation system for increasing engine exhaust velocity. More specifically, the experiment is intended to show that electromagnetic effects are effective at producing flow acceleration whereas electrothermal effects do not cause unacceptable heating of the working fluid. The MHD accelerator was designed as an externally diagonalized segmented Faraday channel, which will be inserted into an existing 2-tesla electromagnet. This allows the external power to be connected through two terminals thereby minimizing the complexity and cost associated with powering each segment independently. The design of the accelerator and other components in the flow path has been completed and fabrication activities are underway. This paper provides a full description of MAPX including performance analysis, design, and test plans, and current status.
A SPATIAL ANALYSIS OF AMENITY AND REGIONAL ECONOMIC GROWTH IN NORTHEAST REGION

Amenities are expected to impact regional economic growth by affecting growth in population, employment, income, and house values. This study assesses whether the 299 counties in the Northeast (NE) region of the US can build and pursue a growth strategy that depends on their local and neighborhood amenities (natural and built). It extends previous studies by estimating a simultaneous spatial Durbin model (SDM) using the two stages least square method. Historical and cultural amenities and water based recreational amenities are found to play a positive role in shaping the growth of population in the northeast region of the US. The role of natural amenities, land and winter based amenities is found to be negative or insignificant. One of the important findings of the study is the positive role of surrounding counties’ historical and cultural amenities in the growth of population and employment densities. Overall there is no evidence of a consistent and strong relationship between amenities and regional economic growth, and the results can be termed “mixed and inconclusive”.
Atom-resolved three-dimensional mapping of boron dopants in Si(100) by scanning tunneling microscopy

The lack of surface states within the band gap of the perfect Si(100)2×1:H surface opens the way to scanning tunneling microscopy studies of dopant atom sites in Si(100). In this letter, boron-induced features on the Si(100)2×1:H surface are studied by ultrahigh vacuum scanning tunneling microscopy. Filled state images show hillock features while empty state images show local depressions associated with dopants. Furthermore, the amplitudes of these hillock features naturally group such that at least three subsurface layers can be identified. Current image tunneling spectroscopy is performed to study the electronic structure of the boron-induced features, which are explained by a simple model based on tip-induced band bending. This technique for producing atom-resolved three-dimensional maps of electrically active dopants in silicon may be a useful metric for characterizing dopant profiles in ultrasmall electronic device structures.
Scaling of peak flows with constant flow velocity in random self-similar networks

Abstract. A methodology is presented to understand the role of the statistical self-similar topology of real river networks on scaling, or power law, in peak flows for rainfall-runoff events. We created Monte Carlo generated sets of ensembles of 1000 random self-similar networks (RSNs) with geometrically distributed interior and exterior generators having parameters pi and pe, respectively. The parameter values were chosen to replicate the observed topology of real river networks. We calculated flow hydrographs in each of these networks by numerically solving the link-based mass and momentum conservation equation under the assumption of constant flow velocity. From these simulated RSNs and hydrographs, the scaling exponents β and φ characterizing power laws with respect to drainage area, and corresponding to the width functions and flow hydrographs respectively, were estimated. We found that, in general, φ > β, which supports a similar finding first reported for simulations in the river network of the Walnut Gulch basin, Arizona. Theoretical estimation of β and φ in RSNs is a complex open problem. Therefore, using results for a simpler problem associated with the expected width function and expected hydrograph for an ensemble of RSNs, we give heuristic arguments for theoretical derivations of the scaling exponents β(E) and φ(E) that depend on the Horton ratios for stream lengths and areas. These ratios in turn have a known dependence on the parameters of the geometric distributions of RSN generators. Good agreement was found between the analytically conjectured values of β(E) and φ(E) and the values estimated by the simulated ensembles of RSNs and hydrographs. The independence of the scaling exponents φ(E) and φ with respect to the value of flow velocity and runoff intensity implies an interesting connection between unit hydrograph theory and flow dynamics. Our results provide a reference framework to study scaling exponents under more complex scenarios of flow dynamics and runoff generation processes using ensembles of RSNs.
β-Bi4(P2Se6)3: A new ternary selenophosphate obtained in a P2Se5 flux

Bi metal dissolves in excess molten phosphorus selenide at 500 °C to yield black, rodlike, air- and water-stable β-Bi4(P2Se6)3 crystals. The phase crystallizes in the triclinic space group P1 (No. 2) with the room-temperature cell parameters a = 12.2303(8) A, b = 6.7640(4) A, c = 17.866 A, α = 90.493(6)°, β = 94.133(6)°, and γ = 91.163(6)°. The new structure is a complicated, three-dimensional framework built from [Bi4Se22] ribbons connected to each other by sharing selenium atoms. The [P2Se6]4- ethane-like units are found inside and between the [Bi4Se22] ribbons. The compound is a semiconductor with a band gap of 1.32 eV. It melts with decomposition at 512 °C, converting partially to Bi2Se3 and a PxSey glassy material. Far-IR and Raman spectra show characteristic stretches for the [P2Se6]4- ligand and Bi−Se vibrations. The structural and chemical relationships of this compound with the α-form are discussed.
Heavy quark physics

Abstract Lattice calculations of heavy quark systems provide very good measures of the lattice spacing, a key element in recent determinations of the strong coupling constant using lattice methods. They also provide excellent testing grounds for lattice methods in general. I review recent phenomenological and technical developments in this field.
Lens with maximum power occupying a given cylindrical volume

This paper describes a method by which designs for high power lenses and lenses constrained to very short spaces can be evaluated or started. First the fundamentally highest power refractive lens is presented. Then the paraxial properties of this lens are fully described followed by a brief third order analysis. 1.
Are Experiments the Only Option? A Look at Dropout Prevention Programs

By comparing experimental and propensity-score impact estimates of dropout prevention programs, we examine whether propensity-score methods produce unbiased estimates of program impacts. We find no consistent evidence that such methods replicate experimental impacts in our setting. This finding holds even when the data available for matching are extensive. Our findings suggest that evaluators who plan to use nonexperimental methods, such as propensity-score matching, need to consider carefully how programs recruit individuals and why individuals enter programs, as unobserved factors may exert powerful influences on outcomes that are not easily captured using nonexperimental methods.
A definition of the crystal commutor using Kashiwara's involution

Henriques and Kamnitzer defined and studied a commutor for the category of crystals of a finite dimensional complex reductive Lie algebra. We show that the action of this commutor on highest weight elements can be expressed very simply using Kashiwara's involution on the Verma crystal.
Packing k-edge trees in graphs of restricted vertex degrees

Let ${\cal G}^{s}_{r}$ denote the set of graphs with each vertex of degree at least r and at most s, v(G) the number of vertices, and τk (G) the maximum number of disjoint k-edge trees in G. In this paper we show that if G ∈ ${\cal G}^{s}_{2}$ and s ≥ 4, then τ2(G) ≥ v(G)s(s + 1), if G ∈ ${\cal G}^{3}_{2}$ and G has no 5-vertex components, then τ2(G) ≥ v(G)4, if G ∈ ${\cal G}^{s}_{1}$ and G has no k-vertex component, where k ≥ 2 and s ≥ 3, then τk(G) ≥ (v(G) -k)s(sk - k + 1), and the above bounds are attained for infinitely many connected graphs. Our proofs provide polynomial time algorithms for finding the corresponding packings in a graph. © 2007 Wiley Periodicals, Inc. J Graph Theory 55: 306–324, 2007
Campaign Dynamics in Battleground and Nonbattleground States

Strategic considerations rooted in the Electoral College sys- tem of presidential elections compel presidential campaigns to allocate resources disproportionately to competitive states. In contemporary cam- paigns, this results in a situation in which many voters are entirely un- exposed to campaign activities over the duration of the campaign. The implications of lopsided communications that relegate voters in uncom- petitive states to bystander status in presidential campaigns are potentially significant and merit greater scrutiny. In this study, I analyze how the dy- namics of voter preferences in uncompetitive states compare to those in battleground states. Using data from the 2000 National Annenberg Elec- tion Survey, I find that the preferences of voters in battleground states are more variable but more stable than their counterparts in nonbattleground states. As expected, I also find stronger evidence of campaign effects in battleground states. Survey researchers routinely probe Americans' presidential vote intentions well in advance of Election Day (Crespi 1988). Scholars have mined these data extensively to investigate the effects of events on campaign dynamics (Gelman and King 1993; Holbrook 1996; Campbell 2000; Johnston, Hagen, and Jamieson 2004), but evidence of substantial movement in voter preferences that can be attributed to the presidential campaign is rare. In their analyses of pres- idential elections between 1944 and 2000, for example, Wlezien and Erikson (2002, p. 978) show that the maximum range of preference variation over the fall campaign, after taking sampling error into account, is about six percentage points on average. Still, the authors conclude that, "campaign events, broadly defined, do have meaningful effects," and that, "(r)eal change in preferences remains and at least some meaningful portion carries over to Election Day."
Managing the super achiever engineer

Guidelines for managing the super achiever are presented. The first step is to identify and classify their problem, plan a solution, and then execute the plan. The personality types that are encounted and the problems they pose for the manager are identified, and suggestions for dealing with them are given. >
Nickel-Catalyzed Cross Couplings of Benzylic Ammonium Salts and Boronic Acids: Stereospecific Formation of Diarylethanes via C–N Bond Activation

We have developed a nickel-catalyzed cross coupling of benzylic ammonium triflates with aryl boronic acids to afford diarylmethanes and diarylethanes. This reaction proceeds under mild reaction conditions and with exceptional functional group tolerance. Further, it transforms branched benzylic ammonium salts to diarylethanes with excellent chirality transfer, offering a new strategy for the synthesis of highly enantioenriched diarylethanes from readily available chiral benzylic amines.
Comment: Bayesian Checking of the Second Levels of Hierarchical Models

Bayarri and Castellanos (BC) have written an interesting paper discussing two forms of posterior model check, one based on cross-validation and one based on replication of new groups in a hierarchical model. We think both these checks are good ideas and can become even more effective when understood in the context of posterior predictive checking. For the purpose of discussion, however, it is most interesting to focus on the areas where we disagree with BC:
Accommodating the effects of brand unfamiliarity in the multidimensional scaling of preference data

This paper presents a multidimensional scaling (MDS) methodology (vector model) for the spatial analysis of preference data that explicitly models the effects of unfamiliarity on evoked preferences. Our objective is to derive a joint space map of brand locations and consumer preference vectors that is free from potential distortion resulting from the analysis of preference data confounded with the effects of consumer-specific brand unfamiliarity. An application based on preference and familiarity ratings for ten luxury car models collected from 240 consumers who intended to buy a luxury car within a designated time frame is presented. The results are compared with those obtained from MDPREF, a popular metric vector MDS model used for the scaling of preference data. In particular, we find that the consumer preference vectors obtained from the proposed methodology are substantially different in orientation from those estimated by the MDPREF model. The implications of the methodology are discussed.
Vibrational analysis of 1,2-dichloroalkanes

Abstract IR and Raman spectra have been obtained for 1,2-dichlorobutane and 1,2-dichloro- pentane. The butane crystallizes in the PXSXH conformation, but the pentane could not be made to crystallize. Normal coordinate calculations were made for the PXSXH, PCSHH, and PHSHH conformers of these two compounds and for 1,2-dichloropropane. The ob- served spectra were interpreted with the aid of these calculations, and it was concluded that all three conformers exist for each of these compounds. The force field that was obtained should be applicable to other 1,2-dichloroalkanes.
Incentives in merchant empires: Portuguese and Dutch compensation schemes

The Portuguese and Dutch merchant empires had a similar geographic distribution with outposts all around the Indian Ocean, which they controlled and manned. Both empires faced the same problem of monitoring their agents in remote corners of the world. Each, however, arrived at a different solution to the monitoring problem. I use a principal–agent model to link different monitoring options to the different organizational structures of the two empires. I further investigate the implications of the model with archival data on labor compensation for Portuguese and Dutch workers overseas.
IMPROVING THE WORLD’S HEALTH THROUGH THE POST-2015 DEVELOPMENT AGENDA: PERSPECTIVES FROM RWANDA

The world has made a great deal of progress through the Millennium Development Goals (MDGs) to improve the health and well-being of people around the globe, but there remains a long way to go. Here we provide reflections on Rwanda’s experience in working to meet the health-related targets of the MDGs. This experience has informed our proposal of five guiding principles that may be useful for countries to consider as the world sets and moves forward with the post-2015 development agenda. These include: 1) advancing concrete and meaningful equity agendas that drive the post-2015 goals; 2) ensuring that goals to meet Universal Health Coverage (UHC) incorporate real efforts to focus on improving quality and not only quantity of care; 3) bolstering education and the internal research capacity within countries so that they can improve local evidence-based policy-making; 4) promoting intersectoral collaboration to achieve goals, and 5) improving collaborations between multilateral agencies – that are helping to monitor and evaluate progress towards the goals that are set – and the countries that are working to achieve improvements in health within their nation and across the world.
Matter from toric geometry

Abstract We present an algorithm for obtaining the matter content of effective six-dimensional theories resulting from compactification of F-theory on elliptic Calabi-Yau threefolds which are hypersurfaces in toric varieties. The algorithm allows us to read off the matter content of the theory from the polyhedron describing the Calabi-Yau manifold. This is based on the generalized Green-Schwarz anomaly cancellation condition.
Short-duration Lensing Events. I. Wide-orbit Planets? Free-floating Low-mass Objects? Or High-velocity Stars?

Short-duration lensing events tend to be generated by low-mass lenses or by lenses with high transverse velocities. Furthermore, for any given lens mass and speed, events of short duration are preferentially caused by nearby lenses (mesolenses) that can be studied in detail, or else by lenses so close to the source star that finite-source-size effects may be detected, yielding information about both the Einstein ring radius and the surface of the lensed star. Planets causing short-duration events may be in orbits with any orientation, and may have semimajor axes smaller than 1?AU, or they may reach the outer limits of their planetary systems, in the region corresponding to the solar system's Oort Cloud. They can have masses larger than Jupiter's or smaller than Pluto's. Lensing therefore has a unique potential to expand our understanding of planetary systems. A particular advantage of lensing is that it can provide precision measurements of system parameters, including the masses of and projected separation between star and planet. We demonstrate how the parameters can be extracted and show that a great deal can be learned. For example, it is remarkable that the gravitational mass of nearby free-floating planet-mass lenses can be measured by complementing observations of a photometric event with deep images that detect the planet itself. A fraction of short events may be caused by high-velocity stars located within a?kiloparsec. Many high-velocity lenses are likely to be neutron stars that received large natal kicks. Other high-speed stars may be members of the halo population. Still others may be hypervelocity stars that have been ejected from the Galactic center, or runaway stars escaped from close binaries, possibly including the progenitor binaries of Type Ia supernovae.
Anisotropic s- or d-wave pairing in the Hubbard model

Abstract The pairing instability in the Hubbard model for a 2D lattice is examined by using the perturbation approach. The two-particle interactions in both singlet and triplet channels are considered. The kernel of two-particle interactions in the charge and spin channels and the irreducible charge and spin response functions are also obtained. The expansion of the equation for the t-matrix over the Legendre polynomials is used to find the singularity in the harmonics of the t-matrix equation for different orbital momenta λ. A pairing instability in the singlet channel can be seen either in the state λ = 0 (s-wave) or in the state with λ = 2 (d-wave). T c for both s- and d-wave states is calculated by using the pole condition of the t-matrix. The strongly anisotropic s-wave state near the antiferromagnetic or SDW instability resembles the d x 2 −y 2 wave symmetry.
A comprehensive study of an online packet scheduling algorithm

We study the bounded-delay model for Qualify-of-Service buffer management. Time is discrete. There is a buffer. Unit-length jobs (also called packets) arrive at the buffer over time. Each packet has an integer release time, an integer deadline, and a positive real value. A packet's characteristics are not known to an online algorithm until the packet actually arrives. In each time step, at most one packet can be sent out of the buffer. The objective is to maximize the total value of the packets sent by their respective deadlines in an online manner. An online algorithm's performance is usually measured in terms of competitive ratio, when this online algorithm is compared with a clairvoyant algorithm achieving the maximum total value. In this paper, we study a simple and intuitive online algorithm. We analyze its performance in terms of competitive ratio for the general model and a few important variants.
Dimensional Reduction of a Layered Metal Chalcogenide into a 1D Near-IR Direct Band Gap Semiconductor

Reducing the dimensionality of inorganic lattices allows for the creation of new materials that have unique optoelectronic properties. We demonstrate that a layered metal chalcogenide lattice, TiS2, can form a dimensionally reduced crystalline one-dimensional hybrid organic/inorganic TiS2(ethylenediamine) framework when synthesized from molecular precursors in solution. This solid has strong absorption above 1.70 eV and pronounced emission in the near-IR regime. The energy dependence of the absorption, the near-IR photoluminescence, and electronic band structure calculations confirm that TiS2(ethylenediamine) has a direct band gap.
Extrinsic properties of automorphism groups of formal groups

Abstract We prove two conjectures on the automorphism group of a one-dimensional formal group law defined over a field of positive characteristic. The first is that if a series commutes with a nontorsion automorphism of the formal group law, then that series is already an automorphism. The second is that the group of automorphisms is its own normalizer in the group of all invertible series over the ground field. A consequence of these results is that a formal group law in positive characteristic is determined by any one of its nontorsion automorphisms.
SENSITIVITY ANALYSIS OF STRUCTURAL RESPONSE UNCERTAINTY PROPAGATION USING EVIDENCE THEORY

Sensitivity analysis for the quantified uncertainty in evidence theory is developed. In reliability quantification, classical probabilistic analysis has been a popular approach in many engineering disciplines. However, when we cannot obtain sufficient data to construct probability distributions in a large-complex system, the classical probability methodology may not be appropriate to quantify the uncertainty. Evidence theory, also called Dempster–Shafer Theory, has the potential to quantify aleatory (random) and epistemic (subjective) uncertainties because it can directly handle insufficient data and incomplete knowledge situations. In this paper, interval information is assumed for the best representation of imprecise information, and the sensitivity analysis of plausibility in evidence theory is analytically derived with respect to expert opinions and structural parameters. The results from the sensitivity analysis are expected to be very useful in finding the major contributors for quantified uncertainty and also in redesigning the structural system for risk minimization.
Computations for support design of measurements of radiation from low velocity shocked air

Hypersonic computational fluid dynamics techniques have recently been used to estimate radiation for vehicles with trajectories in the flight regime of 40 to 60 km altitude and at speeds of about 3.5 km/s. An experiment will be flown shortly to provide the first data to validate these calculations. In this paper, we show how the same computational tools have been used to help in the planning of instruments, primarily for the measurement of optical radiation in the ultraviolet. Theoretical predictions are shown for a sphere-cone vehicle with nose radius of 4 in., at a speed of 3.6 km/s between the altitudes of 40 and 60 km, and are also related to the specific radiometric and spectroscopic measurements planned.
Visual Steering Commands for Trade Space Exploration: User-Guided Sampling With Example

Recent advancements in computing power and speed provide opportunities to revolutionize trade space exploration, particularly for the design of complex systems such as automobiles, aircraft, and spacecraft. In this paper, we introduce three visual steering commands to support trade space exploration and demonstrate their use within a powerful data visualization tool that allows designers to explore multidimensional trade spaces using glyph, 1D and 2D histograms, 2D scatter, scatter matrix, and parallel coordinate plots, linked views, brushing, preference shading, and Pareto frontier display. In particular, we define three user-guided samplers that enable designers to explore (1) the entire design space, (2) near a point of interest, or (3) within a region of high preference. We illustrate these three samplers with a vehicle configuration model that evaluates the technical feasibility of new vehicle concepts. Future research is also discussed.
Optimal Packing Behavior of Some 2-Block Patterns

In this paper, a result of Albert, Atkinson, Handley, Holton, and Stromquist [1, Proposition 2.4] which characterizes the optimal packing behavior of the pattern 1243 is generalized in two directions. The packing densities of layered patterns of type (1α.α) and (1, 1, β) are computed.
Constructing pairwise disjoint paths with few links

Let P be a simple polygon and let l(u1, u′1), (u2, u′2),…,(um, u′m)r be a set of m pairs of distinct vertices of P, where for every distinct i, j ≤ m, there exist pairwise disjoint (nonintersecting) paths connecting ui to u′i and uj to u′j. We wish to construct m pairwise disjoint paths in the interior of P connecting ui to u′i for i = 1, …,m, with a minimal total number of line segments. We give an approximation algorithm that constructs such a set of paths using O(M) line segments in O(n log m p M log m) time, where M is the number of line segments in the optimal solution and n is the size of the polygon.
Awareness and Knowledge of Human Papillomavirus (HPV) Among Ethnically Diverse Women Varying in Generation Status

Although Human papillomavirus (HPV) is a common sexually transmitted infection, there is limited knowledge of HPV with ethnic/racial minorities experiencing the greatest disparities. This cross-sectional study used the most recent available data from the California Health Interview Survey to assess disparities in awareness and knowledge of HPV among ethnically/racially diverse women varying in generation status (N = 19,928). Generation status emerged as a significant predictor of HPV awareness across ethnic/racial groups, with 1st generation Asian-Americans and 1st and 2nd generation Latinas reporting the least awareness when compared to same-generation White counterparts. Also, generation status was a significant predictor of HPV knowledge, but only for Asian-Americans. Regardless of ethnicity/race, 1st generation women reported lowest HPV knowledge when compared to 2nd and 3rd generation women. These findings underscore the importance of looking at differences within and across ethnic/racial groups to identify sub-groups at greatest risk for poor health outcomes. In particular, we found generation status to be an important yet often overlooked factor in the identification of health disparities.
The Quasar SDSS J105041.35+345631.3: Black Hole Recoil Or Extreme Double-Peaked Emitter?

The quasar SDSS J105041.35+345631.3 (z = 0.272) has broad emission lines blueshifted by 3500 km s{sup -1} relative to the narrow lines and the host galaxy. Such an object may be a candidate for a recoiling supermassive black hole, a binary black hole, a superposition of two objects, or an unusual geometry for the broad emission-line region. The absence of narrow lines at the broad line redshift argues against superposition. New Keck spectra of J1050+3456 place tight constraints on the binary model. The combination of large velocity shift and symmetrical Hbeta profile, as well as aspects of the narrow line spectrum, make J1050+3456 an interesting candidate for black hole recoil. Other aspects of the spectrum, however, suggest that the object is most likely an extreme case of a 'double-peaked emitter'. We discuss possible observational tests to determine the true nature of this exceptional object.
Chemical systematics among the moldavite tektites

The compositional variations that occur among the moldavite tektites are caused principally by incomplete mixing of two components during fusion. With the possible exception of silica, there is no evidence for significant losses of volatile species by fractional vaporization. Chemical constraints have been calculated for the two source-materials that contributed to the moldavites. If these tektites were formed by impact fusion, as is commonly believed, then the compositional systematics preserved within the moldavites suggest that hypersonic flow and ejection of impact melts are orderly processes. Insights gained from the study of tektites should prove useful in interpreting the chemistries of impact glasses from other bodies in the solar system.
International comparisons of money demand : a review essay

Many studies of the demand for money, covering a wide variety of economies, have demonstrated the importance of financial innovations and shifts in monetary policy regimes, but they have also illustrated the difficulty of measuring and assessing such changes. Because innovations and regime shifts have differed markedly across countries, international comparisons can help identify their effects. This paper reviews the literature on money demand comparisons, focusing primarily on industrial countries. It finds that innovations have had widespread effects, but also that the demand for money is not generally less stable now than it was before those changes occurred.
Microcanonical D-branes and Back Reaction

Abstract We compare the emission rates from excited D-branes in the microcanonical ensemble with back reaction corrected emission rates from black holes in field theory. In both cases, the rates in the high energy tai] of the spectrum differ markedly from what a canonical ensemble or free field theory approach would yield. Instead of being proportional to a Bose-Einstein distribution function, the rates in the high energy tail are proportional to e−ΔSBH, where ΔSBH is the difference in black hole entropies before and after emission. After including the new effects, we find agreement, at leading order, between the D-brane and field theory rates over the entire range of the spectrum.
Optimal softening for N-body halo simulations

We propose to determine the optimal softening length in N-body halo simulations by minimizing the ensemble-average acceleration error at a small radius r0. This strategy ensures that the error never exceeds the optimal value beyond r0. Furthermore, we derive semianalytic formulae for calculating the acceleration error due to the discreteness of particles and softened gravity, which are validated by direct N-body force calculations. We estimate that current state-of-the-art halo simulations suffer 6% acceleration error at 1% of the halo virial radius. The error grows rapidly toward the center and could contribute significantly to the uncertainties of inner halo properties.
DETECTION OF NETWORK STRUCTURE IN THE LAS CAMPANAS REDSHIFT SURVEY

We employ a percolation technique developed for pointwise distributions to analyze two-dimensional projections of the three northern and three southern slices in the Las Campanas Redshift Survey. One of the goals of this paper is to compare the visual impressions of the structure within distributions with objective statistical analysis. We track the growth of the largest cluster as an indicator of the network structure. We restrict our analysis to volume-limited subsamples in the regions from 200 to 400 h-1 Mpc, where the number density of galaxies is the highest. As a major result, we report a measurement of an unambiguous signal, with a high signal-to-noise ratio (at least at the level of a few σ), indicating significant connectivity of the galaxy distribution which in two dimensions is indicative of a filamentary distribution. This is in general agreement with the visual impression and typical for the standard theory of the large-scale structure formation based on gravitational instability of initially Gaussian density fluctuations.
The Supergroup U(M/N) with Regard to Electronic Hamiltonians

We study the U(M/N) supergroup keeping in mind its connection with electronic Hamiltonians. It is explicitly shown that the generators of the supergroup U(N/N) can be expressed by Clifford operators or Fermi operators. A multi-band supersymmetric electronic model is suggested.
A roadmap for NASA's search for other Earths

The President has identified the search for Earth-like planets around nearby stars as a critical part of NASA's long term Vision for Space Exploration. A suite of space-based missions will determine the incidence of Earth-like planets, detect and characterize the nearest planets, search for signs of life in their atmosphere, as well as make great advances in our understanding of how planetary systems form and evolve. A detailed roadmap lays out the required technology developments, the precursor scientific knowledge, and the capabilities of the relevant missions.
Visualizing molecular wavefunctions using Monte Carlo methods

Using explicitly correlated wavefunctions and variational Monte Carlo we calculate the electron density, the electron density difference, the intracule density, the extracule density, two forms of the kinetic energy density, the Laplacian of the electron density, the Laplacian of the intracule density, and the Laplacian of the extracule density on a dense grid of points for the ground state of the hydrogen molecule at three internuclear distances (0.6, 1.4, 8.0). With these values we construct a contour plot of each function and describe how it can be used to visualize the distribution of electrons in this molecule. We also examine the influence of electron correlation on each expectation value by calculating each function with a Hartree–Fock wavefunction and then comparing these values with our explicitly correlated values. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Baryonic Mass Fraction in Rich Clusters and the Total Mass Density in the Cosmos

Direct observations of the supposedly universal primordial deuterium abundance imply a relatively large baryon density ΩB = (0.019-0.030) h-2 = (0.029-0.10) (95% confidence limit, hereafter CL) for Hubble constant H0 ≡ 100 h = (70 ± 15) km-1 s-1 Mpc-1. From new observations of both the X-ray bremsstrahlung and the Sunyaev-Zeldovich effect, we obtain the baryon fraction in rich clusters, fB = (0.13 ± 0.03)(62/H0)1.4. Together with the observed baryon density this implies that rich clusters are a fair sample of the universe (baryon enhancement ~ 1) and that the cosmic total mass density Ωm = (0.3-0.9) (95% CL). This conclusion agrees with dynamical measures of Ωm on large scales. Conversely, this dynamically measured Ωm > 0.3 (2.4 σ) and the rich cluster limit fB > 0.1 imply ΩB > 0.025 for h < 0.7, ~ 1. This relatively large baryon density is consistent with standard big bang nucleosynthesis and some recent 4He abundance observations.
Sorption-Enhanced Hydrogen Production: A Review

In the sorption-enhanced hydrogen production process, hydrocarbon reforming, water gas shift, and CO2 separation reactions occur simultaneously in a single reaction step over a reforming catalyst mixed with a CO2 sorbent. Transferring CO2 as it is formed from the gas to the solid phase shifts the normal equilibrium restrictions and allows both the reforming and water gas shift reactions to approach completion. Depending on reaction conditions, the product (dry basis) may contain as much as 98% H2 and only ppmv levels of CO and CO2, thereby minimizing the final H2 purification step or even eliminating it for some applications. A number of CO2 sorbents have been studied including calcium-based oxides, K-promoted hydrotalcite, and mixed metal oxides of lithium and sodium. The sorbent is consumed during H2 production so that the process is intrinsically unsteady state. Process economics requires that the sorbent be regenerable and used in many reaction−regeneration cycles. Regeneration may occur via temperatu...
HYPERELLIPTIC JACOBIANS WITHOUT COMPLEX MULTIPLICATION

has only trivial endomorphisms over an algebraic closure of the ground field K if the Galois group Gal(f) of the polynomial f ∈ K[x] is “very big”. More precisely, if f is a polynomial of degree n ≥ 5 and Gal(f) is either the symmetric group Sn or the alternating group An then End(J(C)) = Z. Notice that it easily follows that the ring of K-endomorphisms of J(C) coincides with Z and the real problem is how to prove that every endomorphism of J(C) is defined over K. There are some results of this type in the literature. Previously Mori [8], [9] has constructed explicit examples (in all characteristics) of hyperelliptic jacobians without nontrivial endomorphisms. In particular, he provided examples over Q with semistable Cf and big (doubly transitive) Gal(f) [9]. The semistability of Cf implies the semistability of J(Cf ) and, thanks to a theorem of Ribet [14], all endomorphisms of J(Cf ) are defined over Q. (Applying to Cf/Q the Shafarevich conjecture [17] (proven by Fontaine [3] and independently by Abrashkin [1], [2]) and using Lemma 4.4.3 and arguments on p. 42 of [16], one may prove that the Galois group Gal(f) of the polynomial f involved is S2g+1 where deg(f) = 2g + 1.) Andre ([7], pp. 294-295) observed that results of Katz ([5], [6]) give rise to examples of hyperelliptic jacobians J(Cf ) over the field of rational function C(z) with End(J(Cf )) = Z. Namely, one may take f(x) = h(x)−z where h(x) ∈ C[x] is a Morse function. In particular, this explains Mori’s example [8]
Indirect Impact of Atmospheric Aerosols in Idealized Simulations of Convective–Radiative Quasi Equilibrium

Abstract This paper discusses a cloud-resolving modeling study concerning the impact of warm-rain microphysics on convective–radiative quasi equilibrium with fixed surface characteristics and prescribed solar input, both mimicking the mean conditions on earth. Two limits of the concentration of cloud droplets, either 100 cm−3 (referred to as “pristine”) or 1000 cm−3 (referred to as “polluted”), are considered. In addition, three formulations of the effective radius of water droplets in diluted cloudy volumes are used, corresponding to the homogeneous, intermediate, and extremely inhomogeneous mixing scenarios. The assumed concentration of cloud droplets, together with the assumed mixing scenario, affects the local value of the effective radius of cloud droplets (the first indirect aerosol effect, also known as the Twomey effect) and the transfer of cloud water into drizzle and rain, which can affect the mean cloudiness and the hydrologic cycle (the second indirect effect). The convective–radiative quasi e...
Smart rooms, desks, and clothes

We are working to develop smart networked environments thatcan help people in their homes, offices, cars, and when walking about. Our research is aimed at giving rooms, desks, and clothes the perceptual and cognitive intelligence needed to become active helpers.