cssi/SciSciGPT-SciSciNet huggingface dataset:
The Subduction Zone Flow Field from Seismic Anisotropy: A Global View

Although the morphologies of subducting slabs have been relatively well characterized, the character of the mantle flow field that accompanies subduction remains poorly understood. To analyze this pattern of flow, we compiled observations of seismic anisotropy, as manifested by shear wave splitting. Data from 13 subduction zones reveal systematic variations in both mantle-wedge and subslab anisotropy with the magnitude of trench migration velocity |Vt|. These variations can be explained by flow along the strike of the trench induced by trench motion. This flow dominates beneath the slab, where its magnitude scales with |Vt|. In the mantle wedge, this flow interacts with classical corner flow produced by the convergence velocity Vc; their relative influence is governed by the relative magnitude of |Vt| and Vc.
The geometric Weil representation

We construct a geometric analogue of the Weil representation over a finite field. Our construction is principally invariant, not choosing any specific realization. This eliminates most of the unpleasant formulas that appear in the traditional (non-invariant) approaches, and puts in the forefront some delicate geometric phenomena which underlie this representation.
Synthesis of Monolayer-Capped GaAs Nanoparticles

This paper reports the preliminary results of an investigation of the synthesis of monolayer-capped GaAs nanoparticles using different surface capping molecules. Our approach focuses on the surface encapsulation using alkanethiolates. The organic shell can effectively block the aggregation during nanoparticle synthesis, providing molecular-level control of the core-shell structure. The results have demonstrated the effect of surface alkanethiolate modification on the interparticle spatial properties and particle sizes, which upon further refinement could lead to the ability in controlling the size of GaAs nanoparticles.
How resilient and countercyclical were emerging economies to the global financial crisis

During the crises of the 1990s, emerging economies usually lacked the policy tools to deal with external shocks that were available to advanced economies. Worldwide turbulent episodes found most emerging economies unable to perform countercyclical policies and, in many cases, their own vulnerabilities and poor institutional frameworks amplified negative external shocks leading to sharper recessions. This paper shows that the 2008-2009 global financial crisis represents a structural break in the way emerging economies conduct their policies, with more countercyclical policies pursued before and during the global crisis. Moreover, breaking with the past, emerging economies did not fall more than developed economies during the global financial crisis, thus becoming more similar to developed economies. The resilience of emerging economies during the 2008-2009 crisis might be partly attributed to a combination of sounder macroeconomic and financial policy frameworks with a shift towards safer domestic and international financial stances.
Strategic gaming in electric power markets

Abstract This paper presents an overview of strategic gaming used for understanding the effective company and regulatory strategies for various market participants under alternative scenarios on pricing and institutional structures for electric power. Utilizing the England and Wales (E&W) power pool as a testbed, we develop an aggregate model of payoffs for various stakeholders, under specified demand and supply scenarios, with strategic moves by these stakeholders as the key input to be evaluated. The use of this type of model in a strategic gaming setting is then examined, together with a discussion of experience in using this approach in evaluating a particular decision problem regarding network investment strategies in the E&W power market.
Propositional games with explicit strategies

This paper presents a game semantics for LP, Artemov's Logic of Proofs. The language of LP extends that of propositional logic by adding formula-labeling terms, permitting us to take a term t and an LP formula A and form the new formula tA. We define a game semantics for this logic that interprets terms as winning strategies on the formulas they label, so tA may be read as ''t is a winning strategy on A.''LP may thus be seen as a logic containing in-language descriptions of winning strategies on its own formulas. We apply our semantics to show how winnable instances of certain extensive games with perfect information may be embedded into LP. This allows us to use LP to derive a winning strategy on the embedding, from which we can extract a winning strategy on the original, non-embedded game. As a concrete illustration of this method, we compute a winning strategy for a winnable instance of the well-known game Nim.
Optimum frequency-domain partial response encoding in OFDM system

Time variance of wireless channels destroys the orthogonality among subchannels in orthogonal frequency-division multiplexing (OFDM) systems and causes interchannel interference (ICI), which results in an error floor. In this paper, we study frequency-domain partial-response coding (PRC) for reducing the effect of the ICI. Based on the general expression of the ICI power for OFDM with PRC, the optimum weights for PRC that minimize the ICI power are derived. From the numerical and simulation results, optimum PRC for OFDM can reduce the ICI effectively by 4.0 dB for two-tap PRC and 6.2 dB for three-tap PRC, respectively.
Network Sensitivity Solutions for Regional Moment-Tensor Inversions

Well-resolved moment-tensor solutions reveal information about the sources of seismic waves. In this paper, we introduce a new way of assessing confidence in the regional full moment-tensor inversion via the introduction of the network sensitivity solution (NSS). The NSS takes into account the unique station distribution, frequency band, and signal-to-noise ratio of a given event scenario. The NSS compares both a hypothetical pure source (for example, an explosion or an earthquake) and the actual data with several thousand sets of synthetic data from a uniform distribution of all possible sources. The comparison with a hypothetical pure source provides the theoretically best-constrained source-type distribution for a given set of stations; and with it, one can determine whether further analysis with the data is warranted. The NSS that employs the actual data gives a direct comparison of all other source types with the best-fit source. In this way, one can choose a threshold level of fit in which the solution is comfortably constrained. The method is tested for the well-recorded nuclear test, JUNCTION, at the Nevada Test Site. Sources that fit comparably well to a hypothetical pure explosion recorded with no noise at the JUNCTION data stations have a large volumetric component and are not described well by a double-couple (DC) source. The NSS using the real data from JUNCTION is even more tightly constrained to an explosion because the data contain some energy that precludes fitting with any type of deviatoric source. We also calculate the NSS for the October 2006 North Korea test and a nearby earthquake, where the station coverage is poor and the event magnitude is small. The earthquake solution is very well fit by a DC source, and the best-fit solution to the nuclear test ( M w 4.1) is dominantly explosion.
The design of inhibitors for medicinally relevant metalloproteins

A number of metalloproteins are important medicinal targets for conditions ranging from pathogenic infections to cancer. Many but not all of these metalloproteins contain a zinc(II) ion in the protein active site. Small-molecule inhibitors of these metalloproteins are designed to bind directly to the active site metal ions. In this review several metalloproteins of interest are discussed, including matrix metalloproteinases (MMPs), histone deacetylases (HDACs), anthrax lethal factor (LF), and others. Different strategies that have been employed to design effective inhibitors against these proteins are described, with an effort to highlight the strengths and drawbacks of each approach. An emphasis is placed on examining the bioinorganic chemistry of these metal active sites and how a better understanding of the coordination chemistry in these systems may lead to improved inhibitors. It is hoped that this review will help inspire medicinal, biological, and inorganic chemists to tackle this important problem by considering all aspects of metalloprotein inhibitor design.
Symbolic Dynamics: Entropy = Dimension = Complexity

Let d be a positive integer. Let G be the additive monoid ? d or the additive group ? d . Let A be a finite set of symbols. The shift action of G on A G is given by S g (x)(h) = x(g+h) for all g, h ? G and all x ? A G . A G-subshift is defined to be a nonempty closed set X ⊆ A G such that S g (x)?X for all g ? G and all x ? X. Given a G-subshift X, the topological entropy ent(X) is defined as usual (Ruelle Trans. Am. Math. Soc. 187, 237---251, 1973). The standard metric on A G is defined by ?(x, y) = 2 ? | F n | $2^{-|F_{n}|}$ where n is as large as possible such that x?F n = y?F n . Here F n = {0, 1, ? , n} d if G = ? d , and F n = {?n, ? , ?1, 0, 1, ? , n} d if G = ? d . For any X ⊆ A G the Hausdorff dimension dim(X) and the effective Hausdorff dimension effdim(X) are defined as usual (Hausdorff Math. Ann. 79, 157---179 1919; Reimann 2004; Reimann and Stephan 2005) with respect to the standard metric. It is well known that effdim(X) = sup x?X lim inf n K(x?F n )/|F n | where K denotes Kolmogorov complexity (Downey and Hirschfeldt 2010). If X is a G-subshift, we prove that ent(X) = dim(X) = effdim(X), and ent(X) ? limsup n K(x?F n )/|F n | for all x ? X, and ent(X) = lim n K(x?F n )/|F n | for some x ? X.
Partisanship and Economic Behavior: Do Partisan Differences in Economic Forecasts Predict Real Economic Behavior?

Survey data regularly show that assessments of current and expected future economic performance are more positive when a respondent’s partisanship matches that of the president. To determine if this is a survey artifact or something deeper, we investigate whether partisanship is associated with behavioral differences in economic decisions. We construct a new data set of county-level quarterly taxable sales to examine the effect of partisanship on consumption. Consumption change following a presidential election is correlated with a county’s partisan complexion, a result consistent with partisans acting outside the domain of politics in accordance with the opinions they express in surveys. These results support an expansive view of the role of partisanship in mass politics and help validate surveys as a method for studying political behavior.
ESTIMATING THE INEQUALITY OF HOUSEHOLD INCOMES: A STATISTICAL APPROACH TO THE CREATION OF A DENSE AND CONSISTENT GLOBAL DATA SET

The deficiencies of the Deininger and Squire data set on household income inequality are well known to include sparse coverage, problematic measurements, and the combination of diverse data types into a single data set. Yet many studies have relied on this data due to the lack of available alternatives. In this paper we show how the UTIP-UNIDO measures of manufacturing pay inequality can be used, with other information, to estimate measures of household income inequality. We take advantage of the systematic relationship between the UTIP-UNIDO estimates and those of Deininger and Squire. The residuals from this exercise provide a map to problematic observations in the Deininger and Squire data, and the estimated coefficients provide a way to construct a new panel data set of estimated household income inequality. This new data set provides comparable and consistent measurements across space and through time.
Staged self-assembly and polyomino context-free grammars

Previous work by Demaine et al. (Nat Comput 6937:100---114, 2012) developed a strong connection between smallest context-free grammars and staged self-assembly systems for one-dimensional strings and assemblies. We extend this work to two-dimensional polyominoes and assemblies, comparing staged self-assembly systems to a natural generalization of context-free grammars we call polyomino context-free grammars (PCFGs). We achieve nearly optimal bounds on the largest ratios of the smallest PCFG and staged self-assembly system for a given polyomino with $$n$$n cells. For the ratio of PCFGs over assembly systems, we show that the smallest PCFG can be an $$\varOmega (n/\log ^3{n})$$Ω(n/log3n)-factor larger than the smallest staged assembly system, even when restricted to square polyominoes. For the ratio of assembly systems over PCFGs, we show that the smallest staged assembly system is never more than a $$O(\log {n})$$O(logn)-factor larger than the smallest PCFG and is sometimes an $$\varOmega (\log {n}/\log \log {n})$$Ω(logn/loglogn)-factor larger.
Estimating and sampling graphs with multidimensional random walks

Estimating characteristics of large graphs via sampling is a vital part of the study of complex networks. Current sampling methods such as (independent) random vertex and random walks are useful but have drawbacks. Random vertex sampling may require too many resources (time, bandwidth, or money). Random walks, which normally require fewer resources per sample, can suffer from large estimation errors in the presence of disconnected or loosely connected graphs. In this work we propose a new m-dimensional random walk that uses m dependent random walkers. We show that the proposed sampling method, which we call Frontier sampling, exhibits all of the nice sampling properties of a regular random walk. At the same time, our simulations over large real world graphs show that, in the presence of disconnected or loosely connected components, Frontier sampling exhibits lower estimation errors than regular random walks. We also show that Frontier sampling is more suitable than random vertex sampling to sample the tail of the degree distribution of the graph.
The Energy Endoscope: Real-Time Detailed Energy Accounting for Wireless Sensor Nodes

This paper describes a new embedded networked sensor platform architecture that combines hardware and software tools providing detailed, fine-grained real-time energy usage information. We introduce the LEAP2 platform, a qualitative step forward over the previously developed LEAP and other similar platforms. LEAP2 is based on a new low power ASIC system and generally applicable supporting architecture that provides unprecedented capabilities for directly observing energy usage of multiple subsystems in real-time. Real-time observation with microsecond-scale time resolution enables direct accounting of energy dissipation for each computing task as well as for each hardware subsystem. The new hardware architecture is exploited with our new software tools, etop and endoscope. A series of experimental investigations provide high-resolution power information in networking, storage, memory and processing for primary embedded networked sensing applications. Using results obtained in real-time we show that for a large class of wireless sensor network nodes, there exist several interdependencies in energy consumptionbetween different subsystems. Through the use of our measurement tools we demonstrate that by carefully selecting the system operating points, energy savings of over 60% can be achieved while retaining system performance.
THE STAYING POWER OF LEVERAGED BUYOUTS

This paper documents the organizational status over time of 183 large leveraged buyouts (LBOs) completed between 1979 and 1986. As of August 1990, 63% of the LaOs are privately owned, 14% are independent public companies, and 23% are owned by other public companies As time since the LBO increases, the percentage of LBOs that have returned to public ownership increases. The (unconditional) median time LBOs remain private equals 6.70 years. This evidence suggests that the majority of LBO organizations are neither short-lived nor permanent. In addition the moderate fraction of LBOs assets owned by other (potentially related) companies implies that asset sales play a role in, but are not the primarily force motivating LBO transactions. (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was (This abstract was borrowed from another version of this item.)
The radionactive universe

In a large class of extra-dimensional models, a scalar degree of freedom known as the radion is long-lived, or even stable, on cosmological scales. In this paper we investigate the impact of radionactivity on the evolution of the universe. We demonstrate that whether the radion overcloses the universe, constitutes the dark matter, is the inflaton, the curvaton, or does not play any role in cosmology, depends crucially on the ratio between the energy densities stored in the radion and in the inflaton at the time of inflation. We discuss the general difficulties in reconciling models with low compactification scale (i.e., TeV scale) with the simple picture of inflation.
The Nature of Transition Blazars

Blazars are classically divided into the BL Lacertae (BLL) and flat-spectrum radio quasar (FSRQ) subclasses, corresponding to radiatively inefficient and efficient accretion regimes, respectively, largely based on the equivalent width (EW) of their optical broad emission lines (BELs). However, EW-based classification criteria are not physically motivated, and a few blazars have previously transitioned' from one subclass to the other. We present the first systematic search for these transition blazars in a sample of 602 unique pairs of repeat spectra of 354 blazars in the Sloan Digital Sky Survey, finding six clear cases. These transition blazars have bolometric Eddington ratios of ∼0.3 and low-frequency synchrotron peaks, and are thus FSRQ-like. We show that the strong EW variability (up to an unprecedented factor of >60) is due to swamping of the BELs from variability in jet continuum emission, which is stronger in amplitude and shorter in timescale than typical blazars. Although these transition blazars appear to switch between FSRQ and BLL according to the phenomenologically based EW scheme, we show that they are most likely rare cases of FSRQs with radiatively efficient accretion flows and especially strongly beamed jets. These results have implications for the decrease of the apparent BLL population atmore » high redshifts, and may lend credence to claims of a negative BLL redshift evolution.« less
Pulmonary emphysema decreases hamster skeletal muscle oxidative enzyme capacity

Skeletal muscle oxidative enzyme capacity is impaired in patients suffering from emphysema and chronic obstructive pulmonary disease. This effect may result as a consequence of the physiological de...
Carbon Sequestration in Agricultural Soils: Discounting for Uncertainty

The study presents a conceptual model of an aggregator who selectively pays farmers for altering farming practices in exchange for carbon offsets that the change in practices generates. Under the assumption that the offsets are stochastic and that the aggregator maximizes the sum of the offsets from the purchase that he/she can rightfully claim with a specified level of confidence subject to a budget constraint, we investigate the optimal discounting of expected carbon offsets. We use the model to empirically estimate of the optimal discounting levels and costs for a hypothetical carbon purchasing project in the Upper Iowa River basin. La pr´ ´ porte sur un mod`
Overview of synchrotron radiation facilities

There are 32 laboratories in 12 countries engaged in the operation, construction, or planning of electron storage rings, ranging from a few hundred megaelectronvolts to above 10 GeV, as sources of synchrotron radiation for basic and applied research. More than 6000 scientists now use radiation from 27 operational rings in a wide range of studies in biology, chemistry, and physics and their numerous subfields. About ten more rings intended for research are in construction or design. The new rings are mostly designed with low electron beam emittance and many straight sections to optimize the performance of undulator insertion magnets. In addition, companies in England, Germany, Japan, and the United States are designing and constructing storage rings to produce high fluxes of soft X-rays around 1 keV for the production of integrated circuits with line features of 0.25 mu m or less using the X-ray lithographic process. If, as expected, X-ray lithography becomes the technique of choice for the production of submicron structures, perhaps 100 storage rings in the 0.5- to 1-GeV range will be needed by industry. It is also possible that present programs using synchrotron radiation above 30 keV to develop less invasive procedures for coronary angiography will lead to a need for many multigigaelectronvolt rings designed for this purpose. >
Intellectual Property Rights and the World Trade Organization: Retrospect and Prospects

This paper analyzes the main economic issues of intellectual property rights (IPRs) protection in the context of the World Trade Organization (WTO). A retrospective view on the establishment of the TRIPS (trade-related aspects of intellectual property rights) Agreement, a still controversial accomplishment of the Uruguay Round of trade liberalization, is provided. The paper reviews the economic rationale for the harmonization of IPRs, drawing both on economic theory considerations as well as emerging empirical evidence. The logic of linking IPR protection and trade in the context of the WTO is also re-examined. Some specific attention is devoted to the implications of TRIPS for agricultural and biotechnology innovations. The impact that IPR protection can have in promoting growth and development, and the relation of IPRs with other economic policies, is discussed. The paper concludes with an analysis of the prospects for more (or less) IPRs-related consensus in the current round of WTO negotiations.
The galaxies of nonstandard enlargements of infinite and transfinite graphs

The galaxies of the nonstandard enlargements of connected, conventionally infinite graphs as well as of walk-connected transfinite graphs are defined, analyzed, and illustrated by some examples. It is then shown that any such enlargement either has exactly one galaxy, its principal one, or it has infinitely many galaxies. In the latter case, the galaxies are partially ordered by their ''closeness'' to the principal galaxy. If an enlargement has a galaxy @C different from its principal galaxy, then it has a two-way infinite sequence of galaxies that contains @C and is totally ordered according to that ''closeness'' property. There may be many such totally ordered sequences. Furthermore, a walk-connected graph G^1 of transfinite rank 1 consists in general of connected conventional graphs (graphs of rank 0, called 0-sections) that are walk-connected together at their infinite extremities. The enlargement *G^1 of G^1 consists of the enlargement of G^1, as well as of the enlargements of its 0-sections. The latter enlargements are all contained within the principal galaxy of *G^1. Moreover, *G^1 may have other galaxies of rank 1; these too are partially and totally ordered as before. These results extend to the enlargements of transfinite graphs of ranks greater than 1.
Strongly Correlated Materials

Strongly correlated materials are profoundly affected by the repulsive electron-electron interaction. This stands in contrast to many commonly used materials such as silicon and aluminum, whose properties are comparatively unaffected by the Coulomb repulsion. Correlated materials often have remarkable properties and transitions between distinct, competing phases with dramatically different electronic and magnetic orders. These rich phenomena are fascinating from the basic science perspective and offer possibilities for technological applications. This article looks at these materials through the lens of research performed at Rice University. Topics examined include: Quantum phase transitions and quantum criticality in "heavy fermion" materials and the iron pnictide high temperature superconductors; computational ab initio methods to examine strongly correlated materials and their interface with analytical theory techniques; layered dichalcogenides as example correlated materials with rich phases (charge density waves, superconductivity, hard ferromagnetism) that may be tuned by composition, pressure, and magnetic field; and nanostructure methods applied to the correlated oxides VO₂ and Fe₃O₄, where metal-insulator transitions can be manipulated by doping at the nanoscale or driving the system out of equilibrium. We conclude with a discussion of the exciting prospects for this class of materials.
Synthesis and metal binding properties of salicylate-, catecholate-, and hydroxypyridinonate-functionalized dendrimers.

The synthesis, characteriza- tion, and metal-binding studies of che- late-functionalized dendrimers is report- ed. Salicylate, catecholate, and hydroxy- pyridinonate bidentate chelators have been coupled to the surface of both poly(propyleneimine) (Astramol) and poly(amidoamine) (Starburst, PA- MAM) dendrimers up to the fifth gen- eration (64 endgroups). A general meth- od has been developed for the facile and high quality chromatographic purifica- tion of poly(propyleneimine) and poly- (amidoamine) dendrimer derivatives. One- and two-dimensional (TOCSY) 1 H NMR experiments and electrospray ionization mass spectrometry (ESI-MS) have confirmed the exhaustive coupling of these chelators to the primary amine functionalities of the dendrimers. Spec- trophotometric titrations were used to investigate the metal binding ability of these macrochelates. Spectral analysis shows that ferric iron binding to these ligands is localized to the chelating endgroups. The ability of these dendritic polymers to bind large numbers of metal ions may lead to applications as metal sequestering agents for waste remedia- tion technologies.
Contact/Impact in Hybrid Parameter Multiple Body Mechanical Systems

The multiple motion regime (free/constrained) dynamics of hybrid parameter multiple body (HPMB) systems is addressed. Impact response has characteristically been analyzed using impulse-momentum techniques. Unfortunately, the classical methods for modeling complex HPMB systems are energy based and have proven ineffectual at modeling impact. The problems are exacerbated by the problematic nature of time varying constraint conditions. This paper outlines the reformulation of a recently developed HPMB system modeling methodology into an impulse-momentum formulation, which systematically handles the constraints and impact. The starting point for this reformulation is a variational calculus based methodology. The variational roots of the methodology allows rigorous equation formulation which includes the complete nonlinear hybrid differential equations and boundary conditions. Because the methodology presented in this paper is formulated in the constraint-free subspace of the configuration space, both holonomic and nonholonomic constraints are automatically satisfied. As a result, the constraint-addition/deletion algorithms are not needed. Generalized forces of constraint can be directly calculated via the methodology, so the condition for switching from one motion regime to another is readily determined. The resulting equations provides a means to determine after impact velocities (and velocity fields for distributed bodies) which provide the after collision initial conditions. Finally the paper demonstrates, via example, how to apply the methodology to contact/impact in robotic manipulators and structural systems.
A bonding model of entanglement for N-qubit graph states

The class of entangled N-qubit states known as graph states, and the corresponding stabilizer groups of N-qubit Pauli observables, have found a wide range of applications in quantum information processing and the foundations of quantum mechanics. A review of the properties of graph states is given and core spaces of graph states are introduced and discussed. A bonding model of entanglement for generalized graph states is then presented, in which the presence or absence of a bond between two qubits unequivocally specifies whether or not they are entangled. A physical interpretation of these bonds is given, along with a characterization of how they can be created or destroyed by entangling unitary operations and how they can be destroyed by local Pauli measurements. It is shown that local unitary operations do not affect the bond structure of a graph state, and therefore that if two graph states have nonisomorphic bond structures, then local unitary operations and/or reordering of qubits cannot change one into the other. Color multigraphs are introduced to depict the bond structures of graph states and to make some of their properties more apparent.
Who Is Governing Whom? Executives, Governance, and the Structure of Generosity in Large U.S. Firms

We examine how organizational structure influences strategies over which corporate leaders have significant discretion. Corporate philanthropy is a strategic activity commonly managed through a specific, differentiated organizational structure—the corporate foundation—that formalizes and constrains the influence of individual senior managers and directors on corporate strategy. Our analysis of Fortune 500 firms from 1996 to 2006 shows that characteristics of senior management and directors affect corporate philanthropic contributions. We also find that organizational structure constrains the philanthropic influence of board members, but not of senior managers, a result contrary to what existing theory would predict. We discuss how these findings advance understanding of how organizational structure and corporate leadership interact and how organizations can more effectively realize the strategic value of corporate social responsibility activities.
Magnetic Torquer Attitude Control via Asymptotic Periodic Linear Quadratic Regulation

A method of using magnetic torque rods to do 3axis spacecraft attitude control has been developed. The goal of this system is to achieve a nadir pointing accuracy on the order of 0.1 to 1.0 deg without the need for thrusters or wheels. The open-loop system is under-actuated because magnetic torque rods cannot torque about the local magnetic field direction. This direction moves in space as the spacecraft moves along an inclined orbit, and the resulting system is roughly periodic. Periodic controllers are designed using an asymptotic linear quadratic regulator technique. The control laws include integral action and saturation logic. This system's performance has been studied via analysis and simulation. The resulting closed-loop systems are robust with respect to parametric modeling uncertainty. They converge from initial attitude errors of 30 deg per axis, and they achieve steady-state pointing errors on the order of 0.5 to 1.0 deg in the presence of drag torques and unmodeled residual dipole moments.
Techniques for interactive audience participation

At SIGGRAPH in 1991, Loren and Rachel Carpenter unveiled an interactive entertainment system that allowed members of a large audience to control an onscreen game using red and green reflective paddles. In the spirit of this approach, we present a new set of techniques that enable members of an audience to participate, either cooperatively or competitively, in shared entertainment experiences. Our techniques allow audiences with hundreds of people to control onscreen activity by (1) leaning left and right in their seats, (2) batting a beach ball while its shadow is used as a pointing device, and (3) pointing laser pointers at the screen. All of these techniques can be implemented with inexpensive, off the shelf hardware. Me have tested these techniques with a variety of audiences; in this paper we describe both the computer vision based implementation and the lessons we learned about designing effective content for interactive audience participation.
The Density Profiles of Massive, Relaxed Galaxy Clusters. II. Separating Luminous and Dark Matter in Cluster Cores

We present stellar and dark matter (DM) density profiles for a sample of seven massive, relaxed galaxy clusters derived from strong and weak gravitational lensing and resolved stellar kinematic observations within the centrally located brightest cluster galaxies (BCGs). In Paper I of the series, we demonstrated that the total density profile derived from these data, which span three decades in radius, is consistent with numerical DM-only simulations at radii ≳5-10 kpc, despite the significant contribution of stellar material in the core. Here, we decompose the inner mass profiles of these clusters into stellar and dark components. Parameterizing the DM density profile as a power law ρ_(DM) ∝ r^(–β) on small scales, we find a mean slope (β) = 0.50 ± 0.10(random)^(+0.14)_(–0.13)(systematic). Alternatively, cored Navarro-Frenk-White (NFW) profiles with (log r_(core)/kpc) = 1.14 ± 0.13^(+0.14)_(–0.22) provide an equally good description. These density profiles are significantly shallower than canonical NFW models at radii ≾30 kpc, comparable to the effective radii of the BCGs. The inner DM profile is correlated with the distribution of stars in the BCG, suggesting a connection between the inner halo and the assembly of stars in the central galaxy. The stellar mass-to-light ratio inferred from lensing and stellar dynamics is consistent with that inferred using stellar population synthesis models if a Salpeter initial mass function is adopted. We compare these results to theories describing the interaction between baryons and DM in cluster cores, including adiabatic contraction models and the possible effects of galaxy mergers and active galactic nucleus feedback, and evaluate possible signatures of alternative DM candidates.
The Sources of Regional Variation in the Severity of the Great Depression: Evidence from U.S. Manufacturing, 1919-1937

The impact of the Great Depression was milder in the South Atlantic states, more severe in the Mountain states, and surprisingly uniform across other regions of the country -despite large differences in industrial structure. Employing data on 20 manufacturing industries disaggregated by state, we analyze the relative contributions of industiy mix and location to regional variations in economic performance. Industrial composition had a significant impact on employment growth, with regions that concentrated on durable goods or inputs to construction faring worse than others. Long-run trends also mattered, and explain much of the South Atlantic's more favorable perfonnance. T he Great Depression was a global crisis, but its severity varied both spatially and sectorally. Within the United States, the severity of the 1929 to 1933 contraction differed substantially across regions and cities. Although all regions suffered considerable employment losses, the contraction was relatively milder and shorter in the South Atlantic states and more severe and prolonged in the Rocky Mountain states. The severity of the contraction also varied dramatically across sectors of the economy, with employment falling most in such industries as construction and durables manufacturing, more modestly in the service sector and nondurables manufacturing. The economic fates of regions and industries were clearly linked. Regional economies that were more dependent on cyclically volatile industries were bound to suffer a relatively more severe contraction of economic activity during the Depression. But there may also have been a local component to economic shocks or their propagation that affected all or most industries within a region. A wave of bank failures in a specific region, for example, was a disruption to the region's capital markets that could affect any industry that depended on local sources of capital.
Heterogeneous expectations, adaptive learning, and evolutionary dynamics

This paper presents a linear self-referential macroeconomic model with the possibility of multiple equilibria where agents have the choice of using one of two forecasting models (one of minimum state variable form and the other of sunspot form) to form expectations of current and future prices. Endogenous predictor selection is modeled as an evolutionary game where individuals choose among the forecasting models based on relative performance. Some Nash solutions are not relevant as they are not stable under evolutionary or adaptive learning. Finally, it is shown that the sunspot equilibrium is fragile against temporary shocks to information costs.
Kinetics of imidization and crosslinking in PMR-polyimide resin

Infrared spectroscopy and differential scanning calorimetry were employed to study the imidization and crosslinking kinetics of norbornenyl-capped, addition-type polyimide resins (designated PMR for polymerization of monomer reactants). The spectral and thermal analyses were performed on resin specimens which had been isothermally aged at temperatures appropriate for imidization (120 to 204 C) and crosslinking (275 to 325 C). Imidization occurs rapidly (approximately 0.01/min) at short times, while at times longer than approximately 0.5 hour, the rate decreases significantly (approximately 0.0001/min). The crosslinking reaction exhibits first order kinetics during the initial portion of the reaction and its rate appears to be limited by the reversion of the norbornenyl Diels-Alder adduct. The total heat evolved per mole of endcap during crosslinking shows an inverse dependence on the molecular weight of the imide prepolymers. This reflects the effect of endcap dilution and decreased mobility of the larger oligomers.
Conditional Stability of Unstable Viscous Shock Waves in Compressible Gas Dynamics and MHD

Extending our previous work in the strictly parabolic case, we show that a linearly unstable Lax-type viscous shock solution of a general quasilinear hyperbolic–parabolic system of conservation laws possesses a translation-invariant center stable manifold within which it is nonlinearly orbitally stable with respect to small L1 ∩ H3 perturbations, converging time asymptotically to a translate of the unperturbed wave. That is, for a shock with p unstable eigenvalues, we establish conditional stability on a codimension-p manifold of initial data, with sharp rates of decay in all Lp. For p = 0, we recover the result of unconditional stability obtained by Mascia and Zumbrun. The main new difficulty in the hyperbolic–parabolic case is to construct an invariant manifold in the absence of parabolic smoothing.
The universal relation between scaling exponents in first-passage percolation

It has been conjectured in numerous physics papers that in ordinary rst-passage percolation on integer lattices, the uctuation exponent and the wandering exponent are related through the universal relation = 2 1, irrespective of the dimension. This is sometimes called the KPZ relation between the two exponents. This article gives a rigorous proof of this conjecture assuming that the exponents exist in a certain sense.
The Effects of Minimum Wages on Food Stamp Enrollment and Expenditures

We provide the first causal analysis of how minimum wages affects enrollments and expenditures in the Supplemental Nutrition Assistance Program (SNAP). Exploiting state- and federal-level variation in minimum-wage policy between 1990 and 2012, and incorporating local controls in our specifications, we find that a 10 percent minimum wage increase reduces SNAP enrollment between 2.4 and 3.2 percent, and reduces program expenditures an estimated 1.9 percent. If the federal minimum wage were increased from $7.25 to $10.10, enrollment would fall between 7.5 and 8.7 percent (3.1 to 3.6 million persons) relative to 2012 levels, and annual expenditures would decrease 6 percent ($4.6 billion)
Trifluoromethoxylation of Arenes: Synthesis of ortho‐Trifluoromethoxylated Aniline Derivatives by OCF3 Migration

Aryl trifluoromethoxylation by a two-step sequence of O-trifluoromethylation of N-aryl-N-hydroxylamine derivatives and intramolecular OCF3 migration is presented. This protocol allows easy access to a wide range of synthetically useful ortho-OCF3 aniline derivatives. In addition, it utilizes bench-stable reagents, is operationally simple, shows high functional-group tolerance, and is amenable to gram-scale as well as one-pot synthesis. A reaction mechanism of a heterolytic cleavage of the NOCF3 bond followed by recombination of the resulting nitrenium ion and trifluoromethoxide is proposed for the OCF3-migration reaction.
THE REVOLVING DOOR: DURATION AND RECIDIVISM IN IMF PROGRAMS

Quarterly evidence on participation in IMF programs for the period 1974-2003 is examined statistically using the techniques of hazard analysis and error-correction estimation. Three hypotheses are proposed and tested, and the results support a “revolving door” explanation of participation in IMF programs. First, an increase in cumulative prior participation in IMF programs is found to cause a reduction on average in the length of a new spell of participation. Second, the length of time between participation spells is reduced significantly with an increase in cumulative prior participation in IMF programs. Third, the evolution of reserve adequacy is shown to be significantly and positively affected by participation in IMF programs. The results depict a revolving door to IMF participation, and for those countries with prior participation the door revolves more rapidly. This result is shown to depend critically upon the mix of countries considered. The increase in recidivism is a phenomenon most strongly observed among the least developed countries, while the reduction in duration is more strongly observed in the emerging and transition economies. These results are derived while controlling for country-specific unobserved heterogeneity, year-specific demand effects, external shocks, and pre-existing policy distortions.
Detection of Gauss–Markov Random Fields With Nearest-Neighbor Dependency

The problem of hypothesis testing against independence for a Gauss-Markov random field (GMRF) is analyzed. Assuming an acyclic dependency graph, an expression for the log-likelihood ratio of detection is derived. Assuming random placement of nodes over a large region according to the Poisson or uniform distribution and nearest-neighbor dependency graph, the error exponent of the Neyman-Pearson detector is derived using large-deviations theory. The error exponent is expressed as a dependency-graph functional and the limit is evaluated through a special law of large numbers for stabilizing graph functionals. The exponent is analyzed for different values of the variance ratio and correlation. It is found that a more correlated GMRF has a higher exponent at low values of the variance ratio whereas the situation is reversed at high values of the variance ratio.
Biofuels: Potential Production Capacity, Effects on Grain and Livestock Sectors, and Implications for Food Prices and Consumers

We examined four evolution paths of the biofuel sector using a partial equilibrium world agricultural sector model in CARD that includes the new RFS in the 2007 EISA, a two-way relationship between fossil energy and biofuel markets, and a new trend toward corn oil extraction in ethanol plants. At one extreme, one scenario eliminates all support to the biofuel sector when the energy price is low, while the other extreme assumes no distribution bottleneck in ethanol demand growth when the energy price is high. The third scenario considers a pure market force driving ethanol demand growth because of the high energy price, while the last is a policy-induced shock with removal of the biofuel tax credit when the energy price is high. Standard results hold where the biofuel sector expands with higher energy price, raising the prices of most agricultural commodities through demand side adjustment channels for primary feedstocks and supply side adjustment channels for substitute crops and livestock. On the other hand, the biofuel sector shrinks coupled with opposite impacts on agricultural commodities with the removal of all support including the tax credit. Also, we find that given distribution bottlenecks, cellulosic ethanol crowds marketing channels resulting in a corn-based ethanol price that is discounted. The blenders’ credit and consumption mandates provide a price floor for ethanol and for corn. Finally, the tight linkage between the energy and agricultural sectors resulting from the expanding biofuel sector may raise the possibility of spillover effects of OPEC’s market power on the agricultural sector.
Signaling Performance Over a Piecewise Linear Limited Channel in the Presence of Interference and Gaussian Noise

Presented here are a model and the analysis for evaluating bit error probability of a BPSK signal transmitted through a band-limited piecewise linear (PWL) limited satellite channel subject to continuous wave (CW) interference as well as additive Gaussian noise. The CW interference is assumed to have a random phase over ( 0, 2\pi ) and a fixed frequency f j which may be either in or out of the signal band. The analysis is carried out by first formulating a conditional error probability on the uplink channel noise and the CW interference phase and then averaging over the appropriate random variables through conventional Gaussian quadrature formulas and the moment technique used in [2]. Numerical results for the error rate performance are compared to those of hard-limited channels. The results indicate that a PWL limited channel outperforms a hard-limited channel when the out-of-band CW interference power is close to or greater than the desired signal.
On the Determination of the Worst Allowable Persistent Bounded Disturbance for a System With Constraints

The problem of explicitly determining the worst persistent input disturbance that a closed-loop system can tolerate under prespecified state and control constraints is studied. Verification of designs specifically aimed at maximizing the size of persistent bounded disturbances while satisfying system constraints, typically requires extensive simulations because the exact nature of the worst input is not known. In this paper the exact nature ofthe worst input is completely characterized for both SISO and MIMO cases. A finite number of specific impulse responses of the closed-loop system determines the worst persistent input disturbance. In the case of a SISO with n state constraints (x i ≤ β i ), a control constraint (u ≤ β u ) and an output constraint (y ≤ β 0 ), n + 2 impulse responses are generally needed. With this new result the large number of simulations that is typically needed for design verification can be significantly reduced. Two examples illustrate how the new characterization can be utilized.
Adjuvant Epidermal Growth Factor Receptor Inhibitors in Non-Small Cell Lung Cancer

Nonrandomized studies have suggested a potential benefit with use of an EGFR tyrosine kinase inhibitor in the adjuvant setting in patients with EGFR-mutated non-small cell lung cancer. These nonrandomized studies cannot substitute for well-conducted, adequately powered, prospectively randomized phase III trials. Such trials are under way, and their results are eagerly anticipated.