cssi/SciSciGPT-SciSciNet huggingface dataset:
Party Fragmentation and Presidential Elections in Post-Communist Democracies

Despite its controversial status as a stable governmental form, many of today's societies attempting to make the transition to democracy have or will, for a variety of reasons, choose presidentialism. Meanwhile, the evidence suggests that the combination of presidentialism and multipartism is especially dangerous for democratic stability (Mainwaring 1994). The question this essay addresses, though, is whether presidential elections themselves serve to encourage a fragmented party system, at least in the initial stages of democratization. In transitional political systems presidential elections encourage party fragmentation, but in a way different from that of highly proportional purely parliamentary mechanisms. Specifically, parties proliferate to support the presidential aspirations of political elites. Multivariate regression analysis on cross-sectional aggregate electoral data, supported by extensive outliers diagnostics and assessments of the role of country-specific effects is applied. A nested model is used to discriminate among the secondary hypotheses. Controls include: parliamentary election rules (district magnitude, threshold for representation, adjustment districts, ballot structure), relative timing of presidential and parliamentary elections, and basic societal cleavage structure. Using as our data source the recent elections in East and Central Europe and the European part of the former Soviet Union, we show that presidential elections consistently significantly increase party fragmentation. At the same time, the data are consistent with the hypothesis that presidentialism does encourage the overall consolidation in party systems through voters' abandonment of some parties, akin to Duverger's 'psychological effect'.
Azimuthal asymmetries at HERA: theoretical aspects

Abstract We comment on theoretical aspects of the measurement of azimuthal asymmetries in semi-inclusive charged particle production, made recently by the ZEUS Collaboration at HERA. By taking the ratio of the two measured asymmetries, we find good agreement between the perturbative QCD prediction and the experimental data. To separate the perturbative and nonperturbative contributions to the asymmetries, we suggest that the azimuthal asymmetries of the transverse energy flow be measured as a function of a variable q T related to the pseudorapidity of the energy flow.
Dense medium radiative transfer theory: comparison with experiment and application to microwave remote sensing and polarimetry

The dense medium radiative transfer theory is used to study the multiple scattering of electromagnetic waves in a slab containing densely distributed spherical particles overlying a homogeneous half-space. This theory is used to explain phenomena observed in a controlled laboratory experiment. The experimental data indicate that, in a dense medium with small particles, both the coherent attenuation rate and bistatic intensities first increase with the volume fraction of the particles until a maximum is reached, and then decrease when the volume fraction further increases. Thus, attenuation rates and bistatic scattering exhibit a peak as a function of the concentration of particles. The magnitudes of both are also less than those predicted by the independent scattering assumption and the conventional radiative transfer theory. These phenomena cannot be explained by the conventional radiative transfer theory. It is shown that the dense medium radiative transfer theory is in agreement with these experimental features. >
Ultrafast switching of a nanomagnet by a combined out-of-plane and in-plane polarized spin current pulse

We report on spin valve devices that incorporate both an out-of-plane polarizer (OPP) to quickly excite spin torque (ST) switching and an in-plane polarizer/analyzer (IPP). For pulses <200 ps, we observe reliable precessional switching due largely to ST from the OPP. Compared to a conventional spin valve, for a given current amplitude from ∼2 to 3 times the zero-thermal-fluctuation critical current (Ic0), the addition of the OPP can decrease the pulse width necessary for switching by a factor of 10 or more. The effect of the IPP also has beneficial ST consequences for the short pulse switching behavior.
Efficient Sonogashira Reactions of Aryl Bromides with Alkynylsilanes Catalyzed by a Palladium/Imidazolium Salt System

A palladium/imidazolium chloride system has been used to mediate the cross-coupling reaction of aryl halides with alkynylsilanes. The combination of 3 mol % Pd(OAc)2 and 6 mol % IMes·HCl in the presence of Cs2CO3 as base proves to be a highly efficient system in assisting coupling of aryl bromides with alkynylsilanes.
Management Turnover Following Auditor Resignations

We investigate chief executive officer (CEO) and chief financial officer (CFO) changes in firms that experience an auditor resignation. We argue that boards of directors have incentives to replace these managers following an auditor resignation both to improve financial reporting performance and to restore reporting credibility. We use two control samples, one matched on industry and size and the other comprising firms that experienced client-initiated auditor changes. We observe higher turnover in both CEO and CFO positions following auditor resignations than in either of the two control samples. The incidence in CEO and CFO turnover increases for firms filing auditor resignation-related reportable events.
A hybrid method for modeling polarized radiative transfer in a spherical-shell planetary atmosphere

Abstract The Markov chain method is developed for polarized radiative transfer in a pseudo-spherical atmosphere with solar illumination. This solution is then used as an initial guess of the radiation field for a spherical atmosphere. By use of the short characteristic method, a convergent radiation field throughout the atmosphere is achieved after a few Picard iterations. We verified this hybrid method by comparing numerical results to those obtained by a backward Monte Carlo calculation. We carried out a demonstration calculation by simulating the Titan haze reflected intensity I and Stokes parameter Q, and degree of linear polarization at 934.8 nm wavelength. Comparison of the I and Q images to those measured by the Imaging Science Subsystem instrument on the Cassini spacecraft shows the hybrid method to be useful for radiative transfer analyses for (both optically and physically) thick spherical atmospheres.
Elongation of planar boron clusters by hydrogenation: boron analogues of polyenes.

Dihydrogenated boron clusters, H2Bn– (n = 7–12), were produced and characterized using photoelectron spectroscopy and computational chemistry to have ladderlike structures terminated by a hydrogen atom on each end. The two rows of boron atoms in the dihydrides are bonded by delocalized three-, four-, or five-center σ and π bonds. The π bonding patterns in these boron nanoladders bear similarities to those in conjugated alkenes: H2B7–, H2B8, and H2B9–, each with two π bonds, are similar to butadiene, while H2B102–, H2B11–, and H2B12, each with three π bonds, are analogous to 1,3,5-hexatriene. The boron cluster dihydrides can thus be considered as polyene analogues, or “polyboroenes”. Long polyboroenes with conjugated π bonds (analogous to polyacetylenes), which may form a new class of molecular wires, should exist.
Regiospecific conversion of terminal alkynes to ketol phosphates with an iodine (III)-phosphate reagent

Abstract Terminal alkynes undergo regiospecific conversion to ketol phosphates when treated with the iodine(III)-phosphate 2 in acetonitrile containing water.
LOW MACH NUMBER MODELING OF TYPE I X-RAY BURST DEFLAGRATIONS

The low Mach number approximation (LMNA) is applied to two-dimensional hydrodynamic modeling of type I X-ray bursts on a rectangular patch on the surface of a nonrotating neutron star. Because such phenomena involve decidedly subsonic flows, the time step increase offered by the LMNA makes routine simulations of these deflagrations feasible in an environment where strong gravity produces significant stratification, while allowing for potentially significant lateral differences in temperature and density. The model is employed to simulate the heating, peak, and initial cooling stages in the deep envelope layers of a burst. During the deflagration, Benard-like cells naturally fill up a vertically expanding convective layer. The Mach number is always less than 0.15 throughout the simulation, thus justifying the low Mach number approximation. While the convective layer is superadiabatic on average, significant fluctuations in adiabaticity occur within it on subconvective timescales. Due to convective layer expansion, significant compositional mixing naturally occurs, but tracer particle penetration through the convective layer boundaries on convective timescales is temporary and spatially limited. Thus, mixing occurs on the relatively slow burst timescale through thermal expansion of the convective layer rather than from mass penetration of the convective layer boundary through particle convection. At the convective layer boundaries where mixing is less efficient, the actual temperature gradient more closely follows the Ledoux criterion.
Synthesis, spectral analyses and X-ray diffraction studies of 1:1 (Sc,In)(OH)3

Abstract The crystal structure of 1:1 (Sc,In)(OH)3 was determined by X-ray diffraction techniques. The compound crystallizes in the cubic space group Im3 (Th5, No. 204) with a = 7.9510(1) A obtained from powder diffractometry, F25 = 71(0.007,50) and M20 = 186.6. A single-crystal analysis employing a full-matrix least-squares refinement yielded R = 0.042 and Rw = 0.047. The scandium and indium atoms share the same site with 0.49(1) and 0.50(1) occupancies respectively. Each metal (M) atom is octahedrally coordinated to six oxygen atoms. (Sc,In)(OH)3 forms a polyhedral framework consisting of two slightly distorted pentagonal dodecahedra and 12 heptahedra per unit cell in a body-centered cubic (b.c.c) system. IR and X-ray fluorescence spectral analyses provided additional data. The important bond and contact distances are M-O = 2.148(3) A and O…O ( intermolecular ) = 2.731(14) and 2.905(14) A .
A Dynamical Queue Approach to Intelligent Task Management for Human Operators

Formal methods for task management for human operators are gathering increasing attention to improve efficiency of human-in-the-loop systems. In this paper, we consider a novel dynamical queue approach to intelligent task management for human operators. We consider a model of a dynamical queue, where the service time depends on the server utilization history. The proposed queueing model is motivated by, but not restricted to, widely accepted empirical laws describing human performance as a function of mental arousal. The focus of the paper is to characterize the throughput of the dynamical queue and design corresponding maximally stabilizing task release control policies, assuming deterministic arrivals. We focus extensively on threshold policies that release a task to the server only when the server state is less than a certain threshold. When every task brings in the same deterministic amount of work, we give an exact characterization of the throughput and show that an appropriate threshold policy is maximally stabilizing. The technical approach exploits the optimality of the one-task equilibria class associated with the server dynamics. When the amount of work associated with the tasks is an independent identically distributed (i.i.d.) random variable with finite support, we show that the maximum throughput increases in comparison to the case where the tasks have the same deterministic amount of work. Finally, we provide preliminary empirical evidence in support of the applicability of the proposed approach to systems with human operators.
Low-dimensional structure and magnetism of the quantum antiferromagnet Rb4Cu(MoO4)3 and the structure of Rb4Zn(MoO4)3.

Single crystals of the quantum low-dimensional antiferromagnet Rb4Cu(MoO4)3 and the nonmagnetic analogue Ru4Zn(MoO4)3 have been synthesized by a flux-growth method. Detailed structural studies indi...
D-branes and matrix theory in curved space

Abstract We discuss the relation between supersymmetric gauge theory of branes and supergravity; as it was discovered in D-brane physics, and as it appears in Matrix theory, with emphasis on motion in curved backgrounds. We argue that gauged sigma model Lagrangians can be used as definitions of Matrix theory in curved space.
An Improved Algorithm for Constructing kth-Order Voronoi Diagrams

The kth-order Voronoi diagram of a finite set of sites in the Euclidean plane E2 subdivides E2 into maximal regions such that all points within a given region have the same k nearest sites. Two versions of an algorithm are developed for constructing the kth-order Voronoi diagram of a set of n sites in O(n2 log n + k(n - k) log2 n) time, O(k(n - k)) storage, and in O(n2 + k(n - k) log2 n) time, O(n2) storage, respectively.
Persuasive and Informative Advertising: A Classroom Experiment

The authors outline a pair of classroom activities designed to provide an intuitive foundation to the theoretical introduction of advertising in monopoly markets. The roles of both informative and persuasive advertising are covered. Each student acts as a monopolist and chooses the number of (costly) advertisements and the price. The experiments are intended for intermediate microeconomics or industrial organization courses, but might be used in any course that covers advertising models.
Electron heat flux instabilities in coronal holes: Implications for ion heating

[1] There is growing evidence that the heating of the ions in solar coronal holes and the resulting generation of the fast solar wind is due to cyclotron-resonant damping of ion cyclotron waves. At the same time, the origin of these waves is not understood. In this paper, it is suggested that the waves in the proton cyclotron frequency range are generated by a plasma microinstability due to a heat flux coming from the Sun. A new view is used according to which heat flux is launched intermittently by small-scale reconnection events (nanoflares) at the coronal base. This allows the heat flux to be sporadically large enough to drive the instabilities, while at the same time satisfying the time-averaged energy requirements of the solar wind. It is shown that in a low-beta coronal plasma an electrostatic heat-flux instability has a comparable threshold and much greater growth rate than a shear Alfven heat flux instability. The implications of these instabilities for the ion heating in the coronal holes are discussed.
Daily patterns of ethanol drinking in adolescent and adult, male and female, high alcohol drinking (HAD) replicate lines of rats.

The rationale for our study was to determine the pattern of ethanol drinking by the high alcohol-drinking (HAD) replicate lines of rats during adolescence and adulthood in both male and female rats. Rats were given 30 days of 24 h free-choice access to ethanol (15%, v/v) and water, with ad lib access to food, starting at the beginning of adolescence (PND 30) or adulthood (PND 90). Water and alcohol drinking patterns were monitored 22 h/day with a “lickometer” set-up. The results indicated that adolescent HAD-1 and HAD-2 males consumed the greatest levels of ethanol and had the most well defined ethanol licking binges among the age and sex groups with increasing levels of ethanol consumption throughout adolescence. In addition, following the first week of adolescence, male and female HAD-1 and HAD-2 rats differed in both ethanol consumption levels and ethanol licking behavior. Adult HAD-1 male and female rats did not differ from one another and their ethanol intake or licking behaviors did not change significantly over weeks. Adult HAD-2 male rats maintained a relatively constant level of ethanol consumption across weeks, whereas adult HAD-2 female rats increased ethanol consumption levels over weeks, peaking during the third week when they consumed more than their adult male counterparts. The results indicate that the HAD rat lines could be used as an effective animal model to examine the development of ethanol consumption and binge drinking in adolescent male and female rats providing information on the long-range consequences of adolescent alcohol drinking.
Transonic Limit Cycle Oscillation Analysis Using Reduced Order Aerodynamic Models

Limit cycle oscillations have been observed in flight operations of modern aircraft, wind tunnel experiments and mathematical models. Both fluid and structural nonlinearities are thought to contribute to these phenomena. With recent advances in reduced order aerodynamic modeling, it is now feasible to analyze limit cycle oscillations that may occur in transonic flow including the effects of structural and fluid nonlinearities. In this paper an airfoil with control surface freeplay (a common structural nonlinearity) is used to investigate transonic flutter and limit cycle oscillations. The reduced order aerodynamic model used in this paper assumes the shock motion is small and in proportion to the structural motions.
A framework for autonomy

The development of autonomous planning and control system software often results in a custom design concept and software specific to a particular control application. This paper describes a software framework for orchestrating the planning and execution of autonomous activities of an unmanned vehicle, or a group of cooperating vehicles, that can apply to a wide range of autonomy applications. The framework supports an arbitrary span of autonomous capability, ranging from simple low level tasking, requiring much human intervention, to higher level mission-oriented tasking, requiring much less. The approach integrates the four basic functions of all intelligent devises or agents (plan development, plan monitoring, plan diagnosing, and plan execution), with the mathematical discipline of hierarchical planning and control. The result is a domain-independent software framework, to which domain-dependent modules for planning, monitoring, and diagnosing are easily added. This framework for autonomy, combined with the requisite logic for vehicle control, can then be deployed to realize the desired level of autonomous vehicle operation.
RAAGs in Ham

We prove that every RAAG (a Right-Angled Artin Group) embeds in the group of Hamiltonian symplectomorphisms of the 2-sphere.
Two Algorithms in Search of a Type-System

The authors’ $\mathsf{ATR}$programming formalism is a version of call-by-value $\mathsf{PCF}$under a complexity-theoretically motivated type system. $\mathsf{ATR}$programs run in type-2 polynomial-time and all standard type-2 basic feasible functionals are $\mathsf{ATR}$-definable ( $\mathsf{ATR}$types are confined to levels 0, 1, and 2). A limitation of the original version of $\mathsf{ATR}$is that the only directly expressible recursions are tail-recursions. Here we extend $\mathsf{ATR}$so that a broad range of affine recursions are directly expressible. In particular, the revised $\mathsf{ATR}$can fairly naturally express the classic insertion- and selection-sort algorithms, thus overcoming a sticking point of most prior implicit-complexity-based formalisms. The paper’s main work is in refining the original time-complexity semantics for $\mathsf{ATR}$to show that these new recursion schemes do not lead out of the realm of feasibility.
Confusion of Diffuse Objects in the X-Ray Sky

Most of the baryons in the present-day universe are thought to reside in intergalactic space at temperatures of 105-107 K. X-ray emission from these baryons contributes a modest (~10%) fraction of the ~1 keV background whose prominence within the large-scale cosmic web depends on the amount of nongravitational energy injected into intergalactic space by supernovae and active galactic nuclei. Here we show that the virialized regions of groups and clusters cover over a third of the sky, creating a source-confusion problem that may hinder X-ray searches for individual intercluster filaments and contaminate observations of distant groups.
Label Routing Protocol: A New Cross‐Layer Protocol for Multi‐Hop Ad Hoc Wireless Networks

Compared to the traditional wireless network, the multi‐hop ad hoc wireless network is self‐configurable, dynamic, and distributed. During the past few years, many routing protocols have been proposed for this particular network environment. While in wired and optical networks, multi‐protocol label switching (MPLS) has clearly shown its advantages in routing and switching such as flexibility, high efficiency, scalability, and low cost. However MPLS is complex and does not consider the mobility issue for wireless networks, especially for ad hoc wireless networks. This paper migrates the label concept into the ad hoc network and provides a framework for the efficient label routing protocol(LRP) in such a network. The MAC layer is also optimized with LRP for shorter delay, power saving, and higher efficiency. The simulation results show that the delay is improved significantly with this cross‐layer routing protocol.
Palladium-Catalyzed Polyene Cyclizations of Trienyl Triflates

Synthese de derives d'hexahydro methylene-3 spiro [cyclopentane-1:1'-indenone-4] ou spiro [cyclohexane-1:1'-indenone-4'] a partir de dimethoxy-2,4 cyclohexadiene-1,4, de la trifluoro methanesulfonamide et d'iodo-2' ethyl-6 heptadiene-1,4
Segmentation of 3D range images using pyramidal data structures

Abstract Given a 3D range image of a scene containing multiple arbitrarily shaped objects, we segment the scene into homogeneous surface patches. A new modular framework for the segmentation task has been proposed. In the first module, oversegmentation is achieved using zeroth and first-order local surface properties. The segmentation is then refined in the second module using high order surface representations dictated by the upper level vision tasks. The procedure has been applied successfully to many range images obtained from various institutions, 11 of which are presented here.
A COMMENT ON "PRICE DISPERSION, INFLATION, AND WELFARE" BY A. HEAD AND A. KUMAR ∗

The principal results of Head and Kumar’s article are derived under the natural assumption that the number of price offers received per period by buyers is distributed Poisson. This case is of interest for two reasons. First, because the infinite sums and integrals that enter the equilibrium conditions can be solved in closed form, the derivations of the model’s implications are straightforward. Second, by regarding the arrival rate as the relevant measure of search intensity, the analysis of endogenous search effort is simplified. The empirical relationship between the rate of inflation and cross seller variation in prices has a long history. However, it is primarily empirical work without a theory. The article by Head and Kumar (2005) provides an insightful theoretical foundation for the relationship with empirical content. The primary purpose of this comment is to derive the principal results of the article using a special but natural assumption about the distribution of the number of price quotes received by buyers. Wherever possible, the authors’ notation is utilized. Any new variables are introduced in the text. 2. THE MODEL The model studied is a synthesis of the monetary exchange model proposed by Shi, on one hand, and the price setting model of Burdett and Judd on the other. In the Burdett‐Judd model, each sellers sets its price to maximize expected profit given those of others, the set of prices are described by a price offer c.d.f. F(p), and each buyer observes a random sample of offers from this distribution each period. The number of offers, k ,i sitself a random variable. Let qk represent the probability that k offers will be received by any buyer. In the article, the authors assume that at least one price offer is always received. It will be useful to extend the analysis here slightly by assuming that receiving no offer is a possibility, i.e., q0 ≥ 0.
A general approach to the electromagnetic origin of cosmic ray energy

Abstract No piece of matter can, under ordinary circumstances, contain, in any form, enough energy to provide cosmic ray energies for its particles. However, by evolving a magnetic field, matter can provide a means by which a small amount of ionized matter shot from the region of the magnetic field can, by carrying the magnetic field with it, store up an amount of energy which, estimated per particle, is enormous and of cosmic-ray magnitude. This energy has, in the last analysis, been stolen from a large amount of matter by the small amount. The electromagnetic theorem having to do with the relation between rate of change of electromagnetic energy and rate of doing work on the particles shows that, under suitable conditions, all of the electromagnetic energy, if destroyed, will go into kinetic energy of the particles. The matter is illustrated by considering a ring of gas shot out from a region containing a magnetic field. The ring carries the flux with it, and the corresponding electromagnetic energy becomes destroyed by the subsequent motion of the particles to infinity, to be thought of roughly as a result of the repulsion of the current elements, and more exactly as a result of the electrodynamic forces operating on free particle motion.
The effect of perforating conditions on well performance.

The productivity of a perforated gas well is affected strongly by non-Darcy or turbulent flow through the compacted zone around each perforation. The turbulence coefficient depends on the permeability of this compacted zone. This permeability, a function of perforation condition, can be used with perforation dimensions to predict gas well performance.
Guaranteed quality tetrahedral Delaunay meshing for medical images

In this paper, we present a Delaunay refinement algorithm for meshing 3D medical images. Given that the surface of the represented object is a smooth 2-manifold without boundary, we prove that (a) all the tetrahedra of the output mesh have radius-edge ratio less than 3+2(~1.93), (b) all the boundary facets have planar angles larger than 30 degrees, (c) the symmetric (2-sided) Hausdorff distance between the object surface and mesh boundary is bounded from above by a user-specified parameter, and (d) the mesh boundary is ambient isotopic to the object surface. The first two guarantees assure that our algorithm produces elements of bounded radius-edge ratio. The last two guarantees assure that the mesh boundary is a good geometric and topological approximation of the object surface. Our method also offers control over the size of tetrahedra in the final mesh. Experimental evaluation of our algorithm on synthetic and real medical data illustrates the theory and shows the effectiveness of our method.
Nephrotic syndrome in the second decade of life

In 22 (13 females, 9 males) of 224 patients presenting with nephrotic syndrome, onset occurred during the second decade of life. Lipoid nephrosis and its variants (nil, focal segmental, or focal global glomerulosclerosis and mesangial proliferative) accounted for the disease in the majority of patients (13 patients). In all with nil change (7 patients) and one of the 4 with mesangial proliferation the disease completely resolved with steroids. Forty-one percent of patients had nephrotic syndrome as the result of other forms of glomerulone-phritis: 1 patient had nephrotic syndrome secondary to poststreptococcal glomerulonephritis which resolved spontaneously. Three patients had membranoproliferative glomerulonephritis and developed renal insufficiency. Proteinuria decreased or disappeared in 4 patients with systemic lupus erythematosus. One patient had membranous nephropathy that was steroid resistant. Presenting symptoms and laboratory data failed to separate nil change from the more severe glomerular lesions. Early biopsy for diagnosis is suggested for patients presenting with de novo nephrotic syndrome in the second decade of life.
Improving the performance of weighted Lagrange-multiplier methods for nonlinear constrained optimization

Abstract Nonlinear constrained optimization problems in discrete and continuous spaces are an important class of problems studied extensively in artificial intelligence and operations research. These problems can be solved by a Lagrange-multiplier method in continuous space and by an extended discrete Lagrange-multiplier method in discrete space. When constraints are satisfied, these methods rely on gradient descents in the objective space to find high-quality solutions. On the other hand, when constraints are violated, these methods rely on gradient ascents in the Lagrange-multiplier space in order to increase the penalties on unsatisfied constraints and to force the constraints into satisfaction. The balance between gradient descents and gradient ascents depends on the relative weights between the objective function and the constraints, which indirectly control the convergence speed and solution quality of the Lagrangian method. To improve convergence speed without degrading solution quality, we propose an algorithm to dynamically control the relative weights between the objective and the constraints. Starting from an initial weight, the algorithm automatically adjusts the weights based on the behavior of the search progress. With this strategy, we are able to eliminate divergence, reduce oscillation, and speed up convergence. We show improved convergence behavior of our proposed algorithm on both nonlinear continuous and discrete problems.
Dual Catalysis in Enantioselective Oxidopyrylium-Based [5+2] Cycloadditions

A new method for effecting catalytic enantioselective intramolecular [5 + 2] cycloadditions based on oxidopyrylium intermediates is reported. The dual catalyst system consists of a chiral primary aminothiourea and a second achiral thiourea. Experimental evidence points to a new type of cooperative catalysis with each species being necessary to generate a reactive pyrylium ion pair that undergoes subsequent cycloaddition with high enantioselectivity.
A Direct Approach to Computing Spatially Averaged Outage Probability

This letter describes a direct method for computing the spatially averaged outage probability of a network with interferers located according to a point process and signals subject to fading. Unlike most common approaches, it does not require transforms such as a Laplace transform. Examples show how to directly obtain the outage probability in the presence of Rayleigh fading in networks whose interferers are drawn from binomial and Poisson point processes defined over arbitrary regions. We furthermore show that, by extending the arbitrary region to the entire plane, the result for Poisson point processes converges to the same expression found by Baccelli et al.
Exchange Rate Variability and the Slowdown in Growth of International Trade

The growth rate of international trade among industrial countries has declined by more than half since the inception of floating exchange rates. To explain the slowdown, the effects of exchange rate volatility are separated from those of other shocks since 1973--in particular, changes in oil prices and in trade regimes. The paper focuses on the effects of exchange rate variability with lags longer than a few months or quarters.
Head-Mounted Photometric Stereo for Performance Capture

Head-mounted cameras are an increasingly important tool for capturing facial performances to drive virtual characters. They provide a fixed, unoccluded view of the face, useful for observing motion capture dots or as input to video analysis. However, the 2D imagery captured with these systems is typically affected by ambient light and generally fails to record subtle 3D shape changes as the face performs. We have developed a system that augments a head-mounted camera with LED-based photometric stereo. The system allows observation of the face independent of the ambient light and generates per-pixel surface normals so that the performance is recorded dynamically in 3D. The resulting data can be used for facial relighting or as better input to machine learning algorithms for driving an animated face.
Utility of quantitative ultrasound for tracking the progression of polycystic kidney disease

We are combining techniques of quantitative ultrasonic imaging to study polycystic kidney disease (PKD) as the disease progresses to renal failure. Our goal is to use ultrasound noninvasively to detect morphological changes early in the disease process when interventions are most likely to be successful and prior to a significant loss in renal function. We are examining the kidneys of normal rats and those with PKD at various ages with several techniques to obtain comprehensive knowledge of the disease progression. The Han:SPRD rat inherits PKD as an autosomal dominant trait (ADPKD) that closely mimics ADPKD in humans. Changes in renal function are assessed using tracer kinetics (DTPA) and IOH clearance). Ultrasonic techniques, based on measurements of acoustic backscatter coefficients and parameters derived from these measurements, are sensitive to microscopic changes in the tissue morphology. Elasticity imaging is used to study the changes in the tissue macrostructure. All acoustic measurements are made using a state-of-the-art clinical imaging system (Siemens Elegra). Our results show that ultrasonic techniques are very sensitive to early changes in renal microstructure and macrostructure. Ultrasound can be used to detect changes in the renal cortex long before there is a measurable loss of renal function. These techniques are also useful for monitoring the progression of the disease. Most importantly, these techniques are noninvasive and directly applicable to humans.
Calibration of a digital hadron calorimeter with muons

The calibration procedure of a finely granulated digital hadron calorimeter with Resistive Plate Chambers as the active elements is described. Results obtained with a stack of nine layers exposed to muons from the Fermilab test beam are presented.
Poincaré complex diagonals

Let M be a Poincare duality space of dimension d ≥ 4. In this paper we describe a complete obstruction to realizing the diagonal map M → M × M by a Poincare embedding. The obstruction group depends only on the fundamental group and the parity of d.
On the relation between descriptional complexity and algorithmic probability

Abstract Several results in Algorithmic Information Theory establish upper bounds on the difference between descriptional complexity and the logarithm of ‘a priori probability’. It was conjectured that these two quantities coincide to within an additive constant. Here, we disprove this conjecture and show that the known overall upper bound on the difference is exact. The proof uses a two-person memory-allocation game between players called User and Server. User sends incremental requests of memory space for certain structured items, Server allocates this space in a write-once memory. For each item, some of the allocated space is required to be in one piece, in order to give a short address. We also present some related results.
Average error rate of NCFSK with multi‐branch post‐detection switched diversity

We investigate the performance of non-coherent frequency shift keying (NCFSK) with multi-branch post-detection switched diversity systems. After an appropriate statistical description of the square-law detector output, we derive generic formulas for the symbol/bit error probability of NCFSK for both switch and stay combining (SSC) and switch and examine combining (SEC) schemes. We show that while the SSC scheme does not benefit from more than two diversity paths when the paths are identically distributed, the error performance of SEC improves as the number of antenna paths increases. We consider two detection schemes for NCFSK, one for M-ary FSK and another limited to only BFSK. We show that the second scheme leads to lower error probability performance when both are used to detect binary signals. The mathematical formalism is illustrated with a number of selected numerical examples. Copyright © 2004 John Wiley & Sons, Ltd.
Rocket Vehicle Targeting for the PLACES Ionospheric Plasma Test Series

The PLACES (Position Location and Communication Effects Simulations) test program, conducted in December 1980 at Elgin Gulf Test Range, involved a series of ionospheric releases of barium/barium-nitrate vapor. The program investigated effects of a structured ionospheric plasma (similar to that produced by a highaltitude nuclear detonation) on satellite rf links and provided in situ measurement of the plasma structure. Terrier-Tomahawk rocket systems boosted the barium carrier payloads, beacon payloads (plasma occultation experiment), and probe payloads (plasma in situ measurement). Drifting plasma tracking procedures, beaconand probe-vehicle targeting procedures, and vehicle flight test results are presented.
Kondo Insulator: p -wave Bose Condensate of Excitons

In the Anderson lattice model for a mixed-valent system, the $d\ensuremath{-}f$ hybridization can possess a $p$-wave symmetry. The strongly correlated insulating phase in the mean-field approximation is shown to be a $p$-wave Bose condensate of excitons with a spontaneous lattice deformation. We study the equilibrium and linear response properties across the insulator-metal transition. Our theory supports the empirical correlation between the lattice deformation and the magnetic susceptibility and predicts measurable ultrasonic and high-frequency phonon behavior in mixed-valent semiconductors.
Use of a lifting upper stage to achieve large offsets during ascent to orbit.

Aerodynamic maneuvers performed by a lifting spacecraft boosted to near orbital velocity were studied as a means of reducing tbe velocity requirements for the offset maneuver necessary when the desired final orbit plane does not pass through the launch site. When the aerodynamic maneuvers are performed during gliding flight, a gradient technique used with a digital trajectory simulation showed the optimum bank angle to be near zero at the beginning of the glide and to increase gradually until the desired orbit plane is attained. This is the inverse of the decreasing bank program obtained by investigators of the maximum re-entry cross-range problem. Analytic calculations based on great and minor circle flight approximated the digital velocity requirements (but not bank programs). Effective velocity requirements determined analytically for a constant-speed cruise maneuver were found to be competitive with the glide results. Compared with the conventional impulsive maneuver performed outside the atmosphere, substantial decreases in velocity requirement for either aerodynamic flight mode were realized for a lift-to-drag ratio of 1.3 or greater. Scramjet propulsion for the cruising type of flight was considered as a means of providing the velocity requirement at modest propellant fraction requirements.
Reactor-pumped laser experimental results

Reactor pumped lasers have the potential to be scaled to multi-megawatt power levels with long run times. In proposed designs, the laser will be capable of output powers of several megawatts of power for run times of several hours. Such a laser would have many diverse applications such as material processing, space debris removal and power beaming to geosynchronous satellites or the moon. However, before such systems can be designed, fundamental laser parameters such as small signal gain, saturation intensity and efficiency must be determined over a wide operational parameter space. We have recently measured fundamental laser parameters for a selection of nuclear pumped visible and near IR laser transitions in atomic neon, argon and xenon. An overview of the results of this investigation are presented.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Time-Marching Analysis of Steady Transonic Flow in Turbomachinery Cascades Using the Hopscotch Method

A rapid, time-marching, numerical scheme based on the hopscotch method is presented for solution of steady, two-dimensional, transonic flow in turbomachinery cascades. The scheme is applied to the strong-conservation form of the unsteady Euler equations written in arbitrary curvilinear coordinates. Cascade solutions are obtained on an orthogonal, body-centered coordinate system. Numerical solution results for two turbine cascades are presented and compared with experimental data to demonstrate the accuracy and computational efficiency of the analysis method.Copyright © 1982 by ASME
Bayesian model robustness via disparities

This paper develops a methodology for robust Bayesian inference through the use of disparities. Metrics such as Hellinger distance and negative exponential disparity have a long history in robust estimation in frequentist inference. We demonstrate that an equivalent robustification may be made in Bayesian inference by substituting an appropriately scaled disparity for the log likelihood to which standard Monte Carlo Markov Chain methods may be applied. A particularly appealing property of minimum-disparity methods is that while they yield robustness with a breakdown point of 1/2, the resulting parameter estimates are also efficient when the posited probabilistic model is correct. We demonstrate that a similar property holds for disparity-based Bayesian inference. We further show that in the Bayesian setting, it is also possible to extend these methods to robustify regression models, random effects distributions and other hierarchical models. These models require integrating out a random effect; this is achieved via MCMC but would otherwise be numerically challenging. The methods are demonstrated on real-world data.
Race, Gender, and Class in the Persistence of the Mariel Stigma Twenty Years after the Exodus from Cuba

The study examines the mediating effects of gender, race, and class in the Mariel Cuban immigrant adaptation process. It explores the significance of the Mariel identity by comparing the experiences of pre-1980 arrivals with those of the Mariel cohort (1980–1981) and post-Mariel arrivals (1982–1990, 1990–2000). The central question of the study is the extent to which the Marielitos’ experience as a group with stigmatization and being labeled as “different” and pathological has persisted in having a different effect on their adaptation to the U.S. from that of other Cuban arrivals before and after Mariel. This study bases its definition of stigma on sociologically grounded theoretical orientation of the construction of a social identity in which a dominant group(s) attribute an undesired difference from what was anticipated to an out-group such that it leads to varieties of discrimination that reduce one's life chances.
ConverSS: A Hybrid MAC/Routing Solution for Small-Scale, Convergecast Wireless Networks

In applications involving networks of sensor-equipped autonomous vehicles, it is crucial to have an energy-efficient communication protocol due to the limited on-board batteries. Unlike traditional sensor networks, vehicle sensor networks typically consist of only a small number of nodes. We exploit this fact in our protocol design by optimizing specifically for these mobile small-scale networks. Our proposed solution, ConverSS, is a hybrid MAC/routing protocol that is energy-efficient for vehicle sensor networks. We have evaluated the protocol through simulation in ns-2 and verified its operation in a testbed network deployment. The results show that ConverSS is robust to real-world link impairments and that it outperforms common layered solutions by as much as a factor of 10.
A new neural network control technique for robot manipulators

A new neural network (NN) control technique for robot manipulators is introduced in this paper. The fundamental robot control technique is the model-based computed-torque control which is subjected to performance degradation due. to model uncertainty. NN controllers have been traditionally used to generate a compensating joint torque to account for the effects of the uncertainties. The proposed NN control approach is conceptually different in that it is aimed at prefiltering the desired joint trajectories before they are used to command the computed-torque-controlled robot system (the plant) to counteract performance degradation due to plant uncertainties. In this framework, the NN controller serves as the inverse model of the plant, which can be trained on-line using joint tracking error. Several variations of this basic technique is introduced; Back-propagation training algorithms for the NN controller have been developed. Simulation results have demonstrated the excellent tracking performance of the proposed control technique.
Dependence of the stereochemistries of intramolecular [8+2] cycloadditions of alkenylheptafulvenes on tetraenophile stereochemistry

Abstract The stereochemistries of intramolecular [8+2] cycloadditions of isomeric alkenylheptafulvenes are described. The observed stereoselectivity is consistent with expectation based upon consideration of secondary orbital interactions.
Small Aircraft Transportation System Higher Volume Operations Flight Experiment

This paper summarizes findings from the Small Aircraft Transportation System Higher Volume Operations Flight Experiment. The higher volume operations concept improves efficiency at nontowered, nonradar airports in instrument meteorological conditions. The success of the higher volume operations concept is based on pilot acceptability as determined through objective and subjective assessments when compared with the procedural control operations in use today at nontowered, nonradar-controlled airfields in instrument meteorological conditions. Flight experiment data indicate that the concept is viable. The experiment, flown on a general aviation aircraft, used a subset of the Higher Volume Operations Simulation Experiment scenarios and evaluation pilots to validate the simulation experiment results. Results reveal that all 12 low-time instrument-rated pilots preferred Small Aircraft Transportation System Higher Volume Operations when compared with current procedural separation operations. These pilots also flew the higher volume operations procedures safely and proficiently without additional workload in comparison to today's system. Detailed results of pilot flight technical error and their subjective assessments of workload and situation awareness are presented.
Convenient one-pot synthesis of trans-1,2-diaryloxiranes from the direct coupling of benzyl halides

trans-1,2-Diaryloxiranes were conveniently prepared in an one-pot reaction by the direct coupling of benzyl halides in the presence of silver oxide and DMSO under mild conditions.
Population: Past growth and future control

This paper is the opening chapter and demographic context of a forthcoming book onThe World's Food. It offers a summation of the Malthusian perception of food and population, an overview of population growth in history and the role of the demographic transition. The varying experiences of developing countries in bringing down the birth rate are examined and used as a basis for projecting future population growth.
Fluid circulation in an enclosure generated by electrohydrodynamic conduction phenomenon

Fluid circulation/mixing inside an enclosure, nonmechanically, is of significant importance in various applications. This study investigates, theoretically, the circulation of an isothermal dielectric liquid inside an enclosure based on the electrohydrodynamic (EHD) conduction phenomenon. The theoretical model and the numerical solutions are presented in dimensionless forms to illustrate the effects of the controlling parameters on the induced flow. The EHD induced flow, based on the conduction phenomenon, is associated with the process of dissociation of the neutral electrolytic species and recombination of the generated ions. The charges generated by dissociation are redistributed in the region by the applied electric field resulting in heterocharge layers in the immediate vicinity of the electrodes. The Coulombic attraction between a given electrode and the charges within the corresponding heterocharge layer induces a fluid motion near that electrode. With a proper electrode design, a significant flow circulation/mixing can be achieved within an enclosure based on the conduction phenomenon.