cssi/SciSciGPT-SciSciNet huggingface dataset:
On a Symmetry of Turbulence

This paper presents results on symmetries of the spectrum of singularities for random cascades found in the statistical theory of turbulence. It is shown that empirical dimension curves possess a natural symmetry whose presence restricts the class of allowable probability distributions of the cascade generator in a simple manner. In particular, necessary and sufficient conditions on the probability distribution of the generator are obtained for symmetry of the singularity spectrum within a large class of cascade models.
Simultaneous parameter estimation and image segmentation for image sequence coding

We previously proposed and demonstrated the feasibility of a method for segmenting an image in a sequence of images into regions of stationary, moving, and uncovered background pixels and simultaneously estimating parameters of each region. The basis of our method is the expectation-maximization (EM) algorithm for maximum-likelihood estimation. We view the intensity difference between image frames as the incomplete data and the intensity difference with the region identifier as the complete data. Our previous work focused primarily on the viability of the method and considered only moving and stationary pixels. In particular, we estimated the DCT coefficients of the motion field for the moving pixels allowing motion- compensated reconstruction of image frames. In this paper we extend our previous formulation to include uncovered background pixels, and we present results showing image segmentation and parameter convergence.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
An Approach to Mining Crime Patterns

This paper presents a knowledge discovery effort to retrieve meaningful information about crime from a U.S. state database. The raw data were preprocessed, and data cubes were created using Structured Query Language (SQL). The data cubes then were used in deriving quantitative generalizations and for further analysis of the data. An entropy-based attribute relevance study was undertaken to determine the relevant attributes. A machine learning software called WEKA was used for mining association rules, developing a decision tree, and clustering. SOM was used to view multidimensional clusters on a regular two-dimensional grid.
Notes on nonabelian (0,2) theories and dualities

In this paper we explore basic aspects of nonabelian (0,2) GLSMs in two dimen- sions for unitary gauge groups, an arena that until recently has largely been unexplored. We begin by discussing general aspects of (0,2) theories, including checks of dynamical super- symmetry breaking, spectators and weak coupling limits, and also build some toy models of (0,2) theories for bundles on Grassmannians, which gives us an opportunity to relate physical anomalies and trace conditions to mathematical properties. We apply these ideas to study (0,2) theories on Pfaffians, applying recent perturbative constructions of Pfaffians of Jockers et al. . We discuss how existing dualities in (2,2) nonabelian gauge theories have a simple mathematical understanding, and make predictions for additional dualities in (2,2) and (0,2) gauge theories. Finally, we outline how duality works in open strings in unitary gauge theories, and also describe why, in general terms, we expect analogous dualities in (0,2) theories to be comparatively rare.
Triggering on hard probes in heavy-ion collisions with CMS

We present a study of the CMS trigger system in heavy-ion collisions. Concentrating on two physics channels, dimuons from decays of quarkonia and single jets, we evaluate a possible trigger strategy for Pb + Pb running that relies on event selection solely in the high-level trigger (HLT). The study is based on measurements of the timing performance of the offline algorithms and event-size distributions using full simulations. Using a trigger simulation chain, we compare the physics reach for the jet and dimuon channels using online selection in the HLT to minimum bias running. The results demonstrate the crucial role the HLT will play for CMS heavy-ion physics.
Computational requirements for hypersonic flight performance estimates

The computational requirements for hypersonic flight performance estimates are discussed and a procedure for fulfilling these requirements is presented. In order to effectively use computational fluid dynamics in design, especially for estimating performance quantities, consideration should be given to the credibility of CFD, design sensitivities, test uncertainties, risk assessment, and consistency in determination. It is found that a design-specific computational technology developed with programmatic research can be used in the design of hypervelocity vehicles.
STAR FORMATION LAWS: THE EFFECTS OF GAS CLOUD SAMPLING

Recent observational results indicate that the functional shape of the spatially resolved star formation-molecular gas density relation depends on the spatial scale considered. These results may indicate a fundamental role of sampling effects on scales that are typically only a few times larger than those of the largest molecular clouds. To investigate the impact of this effect, we construct simple models for the distribution of molecular clouds in a typical star-forming spiral galaxy and, assuming a power-law relation between star formation rate (SFR) and cloud mass, explore a range of input parameters. We confirm that the slope and the scatter of the simulated SFR-molecular gas surface density relation depend on the size of the sub-galactic region considered, due to stochastic sampling of the molecular cloud mass function, and the effect is larger for steeper relations between SFR and molecular gas. There is a general trend for all slope values to tend to ~unity for region sizes larger than 1-2?kpc, irrespective of the input SFR-cloud relation. The region size of 1-2?kpc corresponds to the area where the cloud mass function becomes fully sampled. We quantify the effects of selection biases in data tracing the SFR, either as thresholds (i.e., clouds smaller than a given mass value do not form stars) or as backgrounds (e.g., diffuse emission unrelated to current star formation is counted toward the SFR). Apparently discordant observational results are brought into agreement via this simple model, and the comparison of our simulations with data for a few galaxies supports a steep (>1) power-law index between SFR and molecular gas.
Optimum critical impulse for snap-through in systems of one degree of freedom.

Abstract : A general procedure is derived for evaluation of the optimum load history which can cause the snap-through of a nonlinear, dissipative dynamical system of one degree of freedom in such a manner that the total impulse delivered by the load is a minimum. For systems in which dissipative force either is absent or else depends linearly on velocity, the optimum load history for minimum impulse is shown to be an ideal (Dirac-delta function) impulse applied to the system at rest. For nonlinear dissipation, however, the optimum load history has, in general, loads of finite magnitude acting over finite time. A general procedure to determine the optimum load history and the minimum total impulse for nonlinear dissipation is developed. This procedure is illustrated by application to two problems: the circulation of a single pendulum with damping; the snap-through of a simple, nonlinearly viscoelastic truss. (Author)
Artificial heart ventricular design having space and performance characteristics comparable to the heart

Abstract This paper is a report on the development of a complete artificial ventricle assembly having a size comparable to the existing human heart, with an indicated overall hydrodynamic performance equal to, or better than, the healthy heart and with blood passages characterized by obstruction-free and stagnation-free flow. Further, internal automatic flow control of each individual ventricle output must be provided on a pulse by pulse basis, insensitive to position and comparable in response and sensitivity to the intact heart.
Power-law scaling for the adiabatic algorithm for search-engine ranking

An important method for search engine result ranking works by finding the principal eigenvector of the ``Google matrix.'' Recently, a quantum algorithm for generating this eigenvector as a quantum state was presented, with evidence of an exponential speedup of this process for some scale-free networks. Here we show that the run time depends on features of the graphs other than the degree distribution, and can be altered sufficiently to rule out a general exponential speedup. According to our simulations, for a sample of graphs with degree distributions that are scale-free, with parameters thought to closely resemble the Web, the proposed algorithm for eigenvector preparation does not appear to run exponentially faster than the classical case.
An interior-point sequential approximate optimization methodology

The use of optimization in a simulation-based design environment has become a common trend in industry today. Computer simulation tools are commonplace in many engineering disciplines, providing the designers with tools to evaluate a design’s performance without building a physical prototype. This has triggered the development of optimization techniques suitable for dealing with such simulations. One of these approaches is known as sequential approximate optimization. In sequential approximate minimization a sequence of optimizations are performed over local response surface approximations of the system. This paper details the development of an interior-point approach for trust-region-managed sequential approximate optimization. The interior-point approach will ensure that approximate feasibility is maintained throughout the optimization process. This facilitates the delivery of a usable design at each iteration when subject to reduced design cycle time constraints. In order to deal with infeasible starting points, homotopy methods are used to relax constraints and push designs toward feasibility. Results of application studies are presented, illustrating the applicability of the proposed algorithm.
Manifolds with Boundary and of Bounded Geometry

For non–compact manifolds with boundary we prove that bounded geometry defined by coordinate–free curvature bounds is equivalent to bounded geometry defined using bounds on the metric tensor in geodesic coordinates. We produce a nice atlas with subordinate partition of unity on manifolds with boundary of bounded geometry and we study the change of geodesic coordinate maps.
Translation and/or representation

Thinking, looking at, drawing, building... architecture is always proposing shifts from abstract territories (digital or mental) to material bodies. This inf...
Free product von Neumann algebras associated to graphs, and Guionnet, Jones, Shlyakhtenko subfactors in infinite depth

Abstract Given a subfactor planar algebra P , Guionnet, Jones and Shlyakhtenko give a diagrammatic construction of a II 1 subfactor whose planar algebra is P . They showed that if P is finite-depth, then the factors are interpolated free group factors, and they identified the parameters. We prove that if P is infinite-depth, then the factors are isomorphic to L ( F ∞ ) .
Sleep and Epilepsy

Quality sleep is essential for patients with epilepsy, but this aspect of their treatment is frequently overlooked. Sleep disturbance can result in daytime drowsiness, worsening memory, and deteriorating seizure control. In a few patients, recognition and treatment of a coexisting sleep disorder can make the difference between complete seizure control and refractory epilepsy. Sleep has effects on interictal epileptiform discharges, with particular implications for diagnostic studies. Sleep disorders can coexist with epilepsy, leading to errors in diagnosis and worsening of seizures. Some specific syndromes demonstrate unique properties related to sleep. Seizures themselves disrupt sleep, even when occurring during the day, with the potential for persistent drowsiness and, perhaps, further memory dysfunction. Finally, most patients with epilepsy are treated with anticonvulsant drugs, some of which can have adverse (or beneficial) effects on sleep.
Vibronic analysis of circular dichroism spectra of dimeric systems. Chiral molecules consisting of two polyacene chromophores

The CD spectra of (6R,15R)‐(+)‐6,15‐dihydro‐6,15‐ethanonaphtho [2,3‐c]pentaphene (DEP) and (7R,14R)‐(+)‐7,14‐dihydro‐7,14‐ethanondibenz [a,h] anthracene (DEA) are analyzed as dimers of anthracene and naphthalene, respectively. It is shown that vibronic coupling effects are essential in understanding the vibronic structure of CD spectra in these molecules. The simple molecular dimer model is shown to explain the main vibronic features of the CD spectra, but an extension of that model is needed to achieve good quantitative agreement between experimental and theoretical CD spectra for physically reasonable exciton and vibronic coupling parameters. This extended dimer model allows for a mixing of electronic states of monomers via electronic intermonomer interaction. It is shown that the CD spectrum of DEP locates the hidden 1Lb state of the anthracene molecule about 2150 cm−1 above the origin of the 1La state, and that these two states are electronically coupled in DEP. Only these two assumptions taken togeth...
Evaluation of a Modified Monotonic Neuber Relation

It has been proposed in the literature that the Neuber relation be modified to read Ke/Kt × (Kσ/Kt)m = 1 in order to improve its predictive capability when plane strain loading conditions exist. K e , K σ , and K t are respectively the strain, stress, and elastic concentration factors. The exponent m is proposed to be 1 for plane stress and 0 for plane strain. This paper reports the results of biaxial notch root strain measurements on three sets of double-notched aluminum specimens that have different thicknesses and root radiuses. Elastoplastic strains are measured over gage lengths as short as 150 micrometers with a laser-based in-plane interferometric technique. The measured strains are used to compute K e directly and K σ using the uniaxial stress-strain curve. The exponent m can then be determined for each amount of constraint. The amount of constraint is defined as the negative ratio of lateral to longitudinal strain at the notch root and determined from elastic finite element analyses. As this ratio decreases for the three cases, the values of m are found to be 0.65, 0.48, and 0.36. The modified Neuber relation is an improvement, but discrepancies still exist when plastic yielding begins at the notch root.
Thermodynamic Scaling of the Hydrological Cycle of the Last Glacial Maximum

AbstractIn climate models subject to greenhouse gas–induced warming, vertically integrated water vapor increases at nearly the same rate as its saturation value. Previous studies showed that this increase dominates circulation changes in climate models, so that precipitation minus evaporation (P − E) decreases in the subtropics and increases in the tropics and high latitudes at a rate consistent with a Clausius–Clapeyron scaling. This study examines whether the same thermodynamic scaling describes differences in the hydrological cycle between modern times and the last glacial maximum (LGM), as simulated by a suite of coupled ocean–atmosphere models. In these models, changes in water vapor between modern and LGM climates do scale with temperature according to Clausius–Clapeyron, but this thermodynamic scaling provides a poorer description of the changes in P − E. While the scaling is qualitatively consistent with simulations in the zonal mean, predicting higher P − E in the subtropics and lower P − E in th...
A Method for Near-Equilibrium Discrete-Velocity Gas Flows

We present a simulation scheme for discrete-velocity gases based on local thermodynamic equilibrium. Exploting the kinetic nature of discrete-velocity gases, in that context, results in a natural splitting of fluxes, and the resultant scheme strongly resembles the original process. The kinetic nature of the scheme and the modeling of the infinite collision rate limit, result in a small value of the coefficient of (numerical)-viscosity, the behavior of which is remarkably physical. A first-order method and two second-order methods using the total variation diminishing principle are developed and an example application is presented. Given the same computer resources, it is expected that with this approach, a much higher Reynold's number will be achievable than presently possible with either lattice gas automata or lattice Boltzmann approaches. The ideas being general, the scheme is applicable to any discrete-velocity model and to lattice gases as well.
Iridium isotopes and their nuclear spins

The hyperfine structure patterns of some of the significant are lines of iridium have been photographed using as source a hollow cathode tube already described in a paper by the authors on the isotopic constitution of platinum. An examination of the hyperfine structure data of the iridium lines leads to the result that it consists of two isotopes with nuclear spins ½h/2π and 3/2h/2π. A consideration of known facts regarding the occurrence of isotopes of different mass numbers in the various elements has led to the inference that the mass numbers of the two iridium isotopes are 191 and 193 with a relative abundance of nearly 1:2, the isotope with the higher mass number having the higher nuclear spin.
Theory of slope-dependent disjoining pressure with application to Lennard–Jones liquid films

Abstract A liquid film of thickness h 100 nm is subject to additional intermolecular forces, which are collectively called disjoining pressure Π. Since Π dominates at small film thicknesses, it determines the stability and wettability of thin films. Current theory derived for uniform films gives Π = Π ( h ) . This solution has been applied recently to non-uniform films and becomes unbounded near a contact line as h → 0 . Consequently, many different effects have been considered to eliminate or circumvent this singularity. We present a mean-field theory of Π that depends on the slope h x as well as the height h of the film. When this theory is implemented for Lennard–Jones liquid films, the new Π = Π ( h , h x ) is bounded near a contact line as h → 0 . Thus, the singularity in Π ( h ) is artificial because it results from extending a theory beyond its range of validity. We also show that the new Π can capture all three regimes of drop behavior (complete wetting, partial wetting, and pseudo-partial wetting) without altering the signs of the long and short-range interactions. We find that a drop with a precursor film is linearly stable.
Book-to-market across firm size, exchange, and seasonality: Is there an effect?

Fama and French (1992) report that size and the book-to-market ratio capture the cross-sectional variation of average stock returns for the universe of NYSE, Amex, and Nasdaq securities. This paper, in providing an exhaustive exploration of book-to-market across the dimensions of firm size, exchange listing, and calendar seasonally, reports that Fama and French's empirical findings are driven by two features of the data: a January seasonal in the book-to-market effect, and exceptionally low returns on small, young, growth stocks. In the largest size quintile of all firms (accounting for 73% of the total market value of all publicly traded firms), book-to-market has no significant explanatory power on the cross-section of realized returns during the 1963–1995 period. Thus, book-to-market as such would have less importance to money managers than the literature would have led us to believe.
AMP: a science-driven web-based application for the TeraGrid

The Asteroseismic Modeling Portal (AMP) provides a web-based interface for astronomers to run and view simulations that derive the properties of Sun-like stars from observations of their pulsation frequencies. In this paper, we describe the architecture and implementation of AMP, highlighting the lightweight design principles and tools used to produce a functional fully-custom web-based science application in less than a year. Targeted as a TeraGrid science gateway, AMP's architecture and implementation are intended to simplify its orchestration of TeraGrid computational resources. AMP's web-based interface was developed as a traditional standalone database-backed web application using the Python-based Django web development framework, allowing us to leverage the Django framework's capabilities while cleanly separating the user interface development from the grid interface development. We have found this combination of tools flexible and effective for rapid gateway development and deployment.
CHALLENGER: FINE-TUNING THE ODDS UNTIL SOMETHING BREAKS

The Challenger disaster illustrates the effects of repeated successes, gradual acclimatization, and the differing responsibilities of engineers and managers. Past successes and acclimatization alter decision-makers’ beliefs about probabilities of future success. Fine-tuning processes result from engineers’ and managers’ pursuing partially inconsistent goals while trying to learn from their experiences. Fine-tuning reduces probabilities of success, and it continues until a serious failure occurs.
Recursion relations from space-time supersymmetry

We describe a method for obtaining relations between higher derivative interactions in supersymmetric effective actions. The method extends to all orders in the momentum expansion. As an application, we consider the string coupling dependence of the 2kλ16 interaction in type IIB string theory. Using supersymmetry, we show that each of these interactions satisfies a Poisson equation on the moduli space with sources determined by lower momentum interactions. We argue that these protected couplings are only renormalized by a finite number of string loops together with non-perturbative terms. Finally, we explore some consequences of the Poisson equation for low values of k.
SILICON AND OXYGEN ABUNDANCES IN PLANET-HOST STARS

The positive correlation between planet detection rate and host star iron abundance lends strong support to the core accretion theory of planet formation. However, iron is not the most significant mass contributor to the cores of giant planets. Since giant planet cores are thought to grow from silicate grains with icy mantles, the likelihood of gas giant formation should depend heavily on the oxygen and silicon abundance of the planet formation environment. Here we compare the silicon and oxygen abundances of a set of 76 planet hosts and a control sample of 80 metal-rich stars without any known giant planets. Our new, independent analysis was conducted using high resolution, high signal-to-noise data obtained at McDonald Observatory. Because we do not wish to simply reproduce the known planet-metallicity correlation, we have devised a statistical method for matching the underlying [Fe/H] distributions of our two sets of stars. We find a 99% probability that planet detection rate depends on the silicon abundance of the host star, over and above the observed planet-metallicity correlation. We do not detect any such correlation for oxygen. Our results would thus seem to suggest that grain nucleation, rather than subsequent icy mantle growth, is the important limiting factor in forming giant planets via core accretion. Based on our results and interpretation, we predict that planet detection should correlate with host star abundance for refractory elements responsible for grain nucleation and that no such trends should exist for the most abundant volatile elements responsible for icy mantle growth.
Fabrication of Surface Plasmon Resonators by Nanoskiving Single-Crystalline Gold Microplates

This paper demonstrates the sectioning of chemically synthesized, single-crystalline microplates of gold with an ultramicrotome (nanoskiving) to produce single-crystalline nanowires; these nanowires act as low-loss surface plasmon resonators. This method produces collinearly aligned nanostructures with small, regular changes in dimension with each consecutive cross-section: a single microplate thus can produce a number of “quasi-copies” (delicately modulated variations) of a nanowire. The diamond knife cuts cleanly through microplates 35 μm in diameter and 100 nm thick without bending the resulting nanowire and cuts through the sharp edges of a crystal without deformation to generate nanoscale tips. This paper compares the influence of sharp tips and blunt tips on the resonator modes in these nanowires.
Epidemiology of hepatitis C

In the United States, the annual number of newly acquired acute hepatitis C virus (HCV) infections has declined from an estimated 180,000 in the mid 1980s to an estimated 28,000 in 1995. Approximately 25% to 30% of these infections are clinically apparent cases that are sufficiently symptomatic to gain medical attention. Deaths from fulminant hepatitis C are rare. The prevalence of antibody to HCV (anti-HCV) in the general population of the United States is 1.8%, corresponding to an estimated 3.9 million Americans infected with HCV, and an estimated 8,000 to 10,000 deaths each year result from HCV-associated chronic liver disease. HCV infection affects persons of all ages, but most acute cases of hepatitis C and the highest prevalence of anti-HCV are found among young adults. The highest proportion both of incident cases and prevalent infections is among whites, but the highest incidence and prevalence rates are among non-white racial/ethnic groups. In the past, transfusion of blood and blood products was an important source of HCV transmission, but currently, high-risk drug and sexual exposures account for most HCV transmission. Although the incidence of acute hepatitis C has declined, there is a large reservoir of chronically infected Americans who can serve as a source of transmission to others and who are at risk of the severe consequences of chronic liver disease.
Comparing Treatments across Labor Markets: An Assessment of Nonexperimental Multiple-Treatment Strategies

We study the effectiveness of nonexperimental strategies in adjusting for comparison group differences when using data from several programs, each implemented at a different location, to compare their effect if implemented at alternative locations. First, we adjust for individual characteristics differences simultaneously across all groups using unconfoundedness-based and conditional difference-in-difference methods for multiple treatments. Second, we adjust for differences in local economic conditions and stress their role after program participation. Our results show that it is critical to have sufficient overlap across locations in both dimensions and illustrate the difficulty of adjusting for local economic conditions that differ greatly across locations.
Native capillary isoelectric focusing for the separation of protein complex isoforms and subcomplexes

Here we report the use of capillary isoelectric focusing under native conditions for the separation of protein complex isoforms and subcomplexes. Using biologically relevant HIS-tag and FLAG-tag purified protein complexes, we demonstrate the separations of protein complex isoforms of the mammalian target of rapamycin complex (mTORC1 and 2) and the subcomplexes and different phosphorylation states of the Dam1 complex. The high efficiency capillary isoelectric focusing separation allowed for resolution of protein complexes and subcomplexes similar in size and biochemical composition. By performing separations with native buffers and reduced temperature (15 °C) we were able to maintain the complex integrity of the more thermolabile mTORC2 during isoelectric focusing and detection (<45 min). Increasing the separation temperature allowed us to monitor dissociation of the Dam1 complex into its subcomplexes (25 °C) and eventually its individual protein components (30 °C). The separation of two different phosphor...
The geography problem for 4-manifolds with specified fundamental group

For any class M of 4-manifolds, for instance the class M(G) of closed oriented manifolds with π 1 (M) ≅ G for a fixed group G, the geography of M is the set of integer pairs {(σ(M),χ(M)) | M ∈ M}, where σ and χ denote the signature and Euler characteristic. This paper explores general properties of the geography of M(G) and undertakes an extended study of M(Z n ).
Settlement with Multiple Plaintiffs: The Role of Insolvency

This article considers settlement negotiations between one defendant and two plaintiffs when the defendant's assets are limited. Bargaining externalities exist: the acceptance of a settlement offer by one plaintiff may either increase or decrease the other plaintiff's expected payoff at trial. Negotiations fail when the two plaintiffs bargain independently of one another and their payoffs at trial are sufficiently correlated. Collective bargaining, where the plaintiffs accept offers that are in their mutual interest, leads to higher private and social welfare. For intermediate degrees of correlation, collective bargaining shifts bargaining surplus from the plaintiffs to the defendant. For low degrees of correlation, collective bargaining shifts surplus from the defendant to the plaintiffs. (Risk dominance is used to refine the set of equilibria in this last case.) The desirability of plaintiff opt-outs, limited-fund class actions under Rule 23(b)(1)(B), and Chapter 11 bankruptcy law are discussed. Copyright 2002, Oxford University Press.
Using controlled disorder to distinguish s ± and s + + gap structure in Fe-based superconductors

We reconsider the effect of disorder on the properties of a superconductor characterized by a sign-changing order parameter appropriate for Fe-based materials. Within a simple two band model, we calculate simultaneously $T_c$, the change in residual resistivity $\Delta \rho_0$, and the zero-energy density of states, and show how these results change for various types of gap structures and assumptions regarding the impurity scattering. The rate of $T_c$ suppression is shown to vary dramatically according to details of the impurity model considered. We search therefore for a practical, experimentally oriented signature of a gap of the $s_\pm$ type, and propose that observation of particular evolution of the penetration depth, nuclear magnetic resonance relaxation rate, or thermal conductivity temperature dependence with disorder would suffice.
Time-series expansion for reaction processes.

The temporal evolution of reactive systems is studied by means of the exact enumeration of all states of the system for short times. An algorithm for the evaluation of the power series for the basic quantities of interest is presented. In addition, a consistent method of estimating the asymptotic behavior of the series is suggested. This approach is applied to two reaction schemes, ballistic annihilation and diffusive-driven three-species annihilation, where previous Monte Carlo simulations suggest power-law decays for the concentration. In both cases, reasonable estimates for the decay exponents are obtained.
Some observations on Dyson's new symmetries of partitions

We utilize Dyson's concept of the adjoint of a partition to derive an infinite family of new polynomial analogs of Euler's Pentagonal Number Theorem. We streamline Dyson's bijection relating partitions with crank ≤ k and those with k in the Rank-Set of partitions. Also, we extend Dyson's adjoint of a partition to MacMahon's "modular" partitions with modulus 2. This way we find a new combinatorial proof of Gauss's famous identity. We give a direct combinatorial proof that for n > 1 the partitions of n with crank k are equinumerous with partitions of n with crank -k.
On detecting pollution attacks in inter-session network coding

Dealing with pollution attacks in inter-session network coding is challenging due to the fact that sources, in addition to intermediate nodes, can be malicious. In this work, we first define precisely corrupted packets in inter-session pollution based on the commitment of the source packets. We then propose three detection schemes: one hash-based and two MAC-based schemes: InterM acCPK and SpaceMac PM . Inter MacCPK is the first multi-source homomorphic MAC scheme that supports multiple keys. Both MAC schemes can replace traditional MACs, e.g., HMAC, in networks that employ inter-session coding. All three schemes provide in-network detection, are collusion-resistant, and have very low online bandwidth and computation overhead.
Remote sensing of mars' ionosphere and solar wind interaction: Lessons from venus

Although the Phobos spacecraft will make some limited in situ measurements of Mars' upper ionosphere during its transfer orbits, the major part of the mission will be limited to remote sensing by radio occultation and topside sounding methods. To 'calibrate' the former as a means of studying the ionosphere and solar wind interaction, the Pioneer Venus Orbiter radio occultation experiment results are examined in light of what is known from in situ plasma and magnetic field data. This calibration can be used to reassess the data from previous Mars missions and to provide a basis for interpreting data from the upcoming Phobos mission.
Structure and reactivity studies of transition metals ligated by tBuSi3X (X = O, NH, N, S, and CC).

Use of the tBu3Si group can sterically protect O, N, S, and acetylide donors, enabling chemistry at low-coordinate transition metal centers. This article provides examples from these laboratories on the utilization of tBu3SiO−, tBu3SiNH−, tBu3SiN2−, tBu3SiS− and tBu3SiCC− as ligands in exploratory synthesis and reactivity studies of transition metal complexes.
The Externalities of Strong Social Capital: Post-Tsunami Recovery in Southeast India

Much research has implied that social capital functions as an unqualified ‘public good’, enhancing governance, economic performance, and quality-of-life. Scholars of disaster have extended this concept to posit that social capital provides non-excludable benefits to whole communities after major crises. Using qualitative methods to analyse data from villages in Tamil Nadu, India following the 2004 Indian Ocean tsunami, this article demonstrates that high levels of social capital simultaneously provided strong benefits and equally strong negative externalities, especially to those already on the periphery of society. In these villages, high levels of social capital reduced barriers to collective action for members of the uur panchayats (hamlet councils) and parish councils, speeding up their recovery and connecting them to aid organizations, but at the same time reinforced obstacles to recovery for women, Dalits, migrants, and Muslims. These localized findings have important implications for academic studi...
Hydrothermal and postsynthesis surface modification of cubic, MCM-48, and ultralarge pore SBA-15 mesoporous silica with titanium

We describe the introduction of titanium centers to cubic MCM-48 and SBA-15 mesoporous silica by hydrothermal and postsynthetic grafting techniques. MCM-48 was hydrothermally prepared with a gemini surfactant that favors the cubic phase and leads to a high degree of long-range pore ordering. This phase was chosen due to its high surface area (1100−1300 m2/g) and its three-dimensional, bicontinuous pore array. SBA-15, synthesized with a block copolymer template under acidic conditions, has a surface area from 600 to 900 m2/g and an average pore diameter of 69 A, compared to 24−27 A for MCM-48. Alkoxide precursors of titanium were used to prepare samples of Ti-MCM-48 and Ti-SBA-15. We have detailed the bulk and molecular structure of both the silica framework and the local bonding environment of the titanium ions within each matrix. X-ray powder diffraction and nitrogen adsorption shows the pore structure is maintained despite some shrinkage of the pore diameter at high Ti loadings by grafting methods. UV−v...
Highly selective reducing agents. Reduction of nitrobenzene to aniline in the presence of aldehydes, alkyl halides, and acid halides.

Abstract Although the anionic hydride [HFe(CO) 4 ] − is capable of reducing ketones and aldehydes under acidic conditions, it also selectively reduces nitrobenzene to aniline, even in the presence of benzaldehyde, benzyl chloride, or benzoyl chloride.
Patterns of occupational mobility among Negro men

The survey of “Occupational Changes in a Generation,” conducted by the United States Bureau of the Census in March, 1962, gives tables on intergenerational mobility (father's occupation to first job and father's occupation to 1962 occupation) and on intragenerational mobility (first job to 1962 occupation). The mobility tables for Negro and non-Negro men aged 25–64 years reveal pronounced contrasts. The majority of Negro men, regardless of their social origins, found themselves in lower manual jobs (operatives, service workers, or laborers) in 1962. For them, it was only a slight advantage to have grown up in a family whose head was a higher white-collar (professional, managerial, proprietor) worker. For the majority of non-Negro men (overwhelmingly white), by contrast, such favorable origins meant that they remained at the higher white-collar level, and a near majority of white men who originated at the lower white-collar level moved up to the higher level. Negro men who originated at the lower levels were likely to remain there; white men were likely to move up. Negro men who originated at the higher levels were likely to move down; white men were likely to stay there. Although Negro social origins are not as favorable as those of whites, this is the lesser part of the explanation of racial differences in occupation achievement. The greater part of the explanation lies in inequalities within the process of mobility itself.
Substitution elasticities between durable and nondurable goods in the United States: New evidence from the dynamic Laurent system

This paper uses the dynamic Laurent demand system to jointly estimate the service flows from durable and nondurable goods. The parameter estimates are used to obtain the Morishima elasticity of substitution between goods for the United States from 1960:1 to 1991:4. One of the significant results of this study is that the Morishima elasticities of substitution vary over time instead of being constant. This result implies that the use of the CES functional form gives a poor approximation of the demand system for the data used in this paper. Another important result is that consumers adjust to their long-run equilibrium holding of consumption goods slowly rather than quickly.
Bonding and Reactivity of Heavier Group 14 Element Alkyne Analogues

In this short review recent developments in the synthesis and spectroscopic characterization, as well as the bonding and reactivity, of heavier group 14 element alkyne analogues (REER, R = large aryl or silyl group; E = Si−Pb) are summarized. Stable1 examples of such compounds have been known only since 2000, although their bonding has been studied by theoretical methods since the early 1980s. The use of very large substituents has enabled their isolation and the study of their reactions at room temperature. All the currently known compounds possess trans-bent planar core structures and nonbonded electron density at the tetrel (group 14 element). The bending increases with increasing atomic number, and when E = Pb the triple bonding seen in the lighter carbon homologue has been transformed into a single bond and two nonbonded electron pairs. To a crude approximation the bond order decreases by ca. 0.5 of a unit between elements upon descending the group. Currently available reactivity data show that the s...
Jointly clustering rows and columns of binary matrices: algorithms and trade-offs

In standard clustering problems, data points are represented by vectors, and by stacking them together, one forms a data matrix with row or column cluster structure. In this paper, we consider a class of binary matrices, arising in many applications, which exhibit both row and column cluster structure, and our goal is to exactly recover the underlying row and column clusters by observing only a small fraction of noisy entries. We first derive a lower bound on the minimum number of observations needed for exact cluster recovery. Then, we study three algorithms with different running time and compare the number of observations needed by them for successful cluster recovery. Our analytical results show smooth time-data trade offs: one can gradually reduce the computational complexity when increasingly more observations are available.
SKED: A Course Scheduling and Advising Software

Each year at the beginning of a new academic semester, most advisors face a very common and particularly tedious and time consuming problem: deciding for each student what course schedule would be ideal for the following semester so that the student would graduate in the fastest possible time and also have his / her specific preferences and pre-requisites satisfied. The factors that have to be considered vary from school specific requirements such as course pre-requisites, co-requisites, spring and fall offerings, to student specific ones, such as transferred credits or the subjective desire to choose or not a given choice. While some advisors might be able to derive reasonable solutions in reasonable amount of time, the process takes most of the advising time. The student will have to "trust" the advisor that the given schedule is the best choice, and in many cases the results will later on prove that the student could have actually graduated faster, or that specific school requirements have been violated or imply that the student's load and preference could have been balanced better. This paper presents a software application that can completely solve the presented problem. Once the school specific data and requirements have been set, for any specific student information, the application will search and output the schedules that will allow the student to graduate in the fastest number of semesters / quarters possible. Depending on the factors and data considered, the execution time varies from few seconds to few minutes. Currently, we have successfully tested and implemented the application at the University of Bridgeport, CT, USA.
Effective Count-Rates for PET Scanners with Reduced and Extended Axial Field of View

We investigated the relationship between noise equivalent count (NEC) and axial field of view (AFOV) for PET scanners with AFOVs ranging from one-half to twice those of current clinical scanners. PET scanners with longer or shorter AFOVs could fulfill different clinical needs depending on exam volumes and site economics. Using previously validated Monte Carlo simulations, we modeled true, scattered and random coincidence counting rates for a PET ring diameter of 88 cm with 2, 4, 6, and 8 rings of detector blocks (AFOV 7.8, 15.5, 23.3, and 31.0 cm). Fully 3D acquisition mode was compared to full collimation (2D) and partial collimation (2.5D) modes. Counting rates were estimated for a 200 cm long version of the 20 cm diameter NEMA count-rate phantom and for an anthropomorphic object based on a patient scan. We estimated the live-time characteristics of the scanner from measured count-rate data and applied that estimate to the simulated results to obtain NEC as a function of object activity. We found NEC increased as a quadratic function of AFOV for 3D mode, and linearly in 2D mode. Partial collimation provided the highest overall NEC on the 2-block system and fully 3D mode provided the highest NEC on the 8-block system for clinically relevant activities. On the 4-, and 6-block systems 3D mode NEC was highest up to ~300 MBq in the anthropomorphic phantom, above which 3D NEC dropped rapidly, and 2.5D NEC was highest. Projected total scan time to achieve NEC-density that matches current clinical practice in a typical oncology exam averaged 9, 15, 24, and 61 min for the 8-, 6-, 4-, and 2-block ring systems, when using optimal collimation. Increasing the AFOV should provide a greater than proportional increase in NEC, potentially benefiting patient throughput-to-cost ratio. Conversely, by using appropriate collimation, a two-ring (7.8 cm AFOV) system could acquire whole-body scans achieving NEC-density levels comparable to current standards within long, but feasible, scan times.
Rhodium-Catalyzed [3 + 2] Annulation of Indoles

An effective Rh2(S-DOSP)4-catalyzed asymmetric cyclopentannulation of indolyl rings has been developed. Depending on the substitution pattern of the indole, two distinct regioisomeric products can be generated. These studies demonstrate that rhodium-catalyzed reactions of donor/acceptor carbenoids proceeding by means of zwitterionic intermediates can be carried out with very high asymmetric induction.
Minimal normal-form method for discrete maps

Normal-form methods for solving nonlinear differential equations are reviewed and the comparative merits of three methods are evaluated. The method of minimal normal forms is then extended to apply to the evaluation of discrete maps of an accelerator or storage ring. Such an extension, as suggested in this paper, is more suited for accelerator-based applications than a formulation utilizing continuous differential equations. A computer code has been generated to implement systematically various normal-form formulations for maps in two-dimensional phase space. Specific examples of quadratic and cubic nonlinear fields were used and solved by the method developed. The minimal normal-form method shown here gives good results using relatively-low-order expansions.
Effect of Bulk-Reacting Liners on Wave Propagation in Ducts

An analysis is presented for the effect of bulk-reacting liners on the wave propagation and attenuation in twodimensional and circular ducts carrying sheared mean flow. The wave propagation in an isotropic porous material lining the walls is coupled with wave propagation in the duct. The results indicate that the porosity and structure factor of the porous material have a non-negligible effect on the attenuation rate. The attenuation rate does not increase monotonically with either the liner thickness or resistivity. Considerable error may be introduced by treating a bulk-reacting liner as a point-reacting liner.
Efficacy of home glucose monitoring in diabetic pregnancy

A randomized, prospective study was performed to evaluate the efficacy of daily home glucose monitoring on the outcome of pregnancies in women with insulin-dependent diabetes mellitus. Home glucose monitoring was compared with a weekly venipuncture protocol. No differences were observed between groups in clinical features (age, parity, White's classification) or representative delivery outcomes (method of delivery, weeks' gestation, or weight at birth). No statistically significant differences were observed between the groups in several aspects of perinatal morbidity. However, home glucose monitoring was associated with fewer readmissions for diabetic control (p = 0.05), fewer days in the hospital (p less than 0.01), and decreased total patient expense (p less than 0.05).
Homogenization for nonlinear PDEs in general domains with oscillatory Neumann boundary data

Abstract In this article we investigate averaging properties of fully nonlinear PDEs in bounded domains with oscillatory Neumann boundary data. The oscillation is periodic and is present both in the operator and in the Neumann data. Our main result states that, when the domain does not have flat boundary parts and when the homogenized operator is rotation invariant, the solutions uniformly converge to the homogenized solution solving a Neumann boundary problem. Furthermore we show that the homogenized Neumann data is continuous with respect to the normal direction of the boundary. Our result is the nonlinear version of the classical result in [3] for divergence-form operators with co-normal boundary data. The main ingredients in our analysis are the estimate on the oscillation on the solutions in half-spaces (Theorem 3.1), and the estimate on the mode of convergence of the solutions as the normal of the half-space varies over irrational directions (Theorem 4.1).