cssi/SciSciGPT-SciSciNet huggingface dataset:
Analysis of adaptive step-size SA algorithms for parameter tracking

We present proofs and data for adaptive step-size algorithms for tracking time-varying parameters when recursive stochastic approximation type algorithms are used. A classical problem in adaptive control and communication theory concerns the tracking of the best fit of a given form when the statistics or the parameters change slowly. A major, and yet unresolved, problem has been the choice of the step sizes in the tracking algorithm. An algorithm for adapting the step size using the same system measurements which are used for the tracking was suggested by Benveniste and various examples worked out by Brossier. The numerical results were very encouraging. But proofs were lacking. These proofs are supplied here together with supporting numerical data. The proofs are based on recent results in stochastic approximation. The adaptive step-size technique works very well indeed. Much supporting analysis is presented, particularly concerning the interpretation of certain stationary processes as "stationary" pathwise derivatives. Finite difference forms are also treated. These are mathematically simpler and can be applied to a wide variety of systems, even when the system is not well modeled. The data shows that they work well. >
Open vs. Closed Access Femtocells in the Uplink

Femtocells are assuming an increasingly important role in the coverage and capacity of cellular networks. In contrast to existing cellular systems, femtocells are end-user deployed and controlled, randomly located, and rely on third party backhaul (e.g. DSL or cable modem). Femtocells can be configured to be either open access or closed access. Open access allows an arbitrary nearby cellular user to use the femtocell, whereas closed access restricts the use of the femtocell to users explicitly approved by the owner. Seemingly, the network operator would prefer an open access deployment since this provides an inexpensive way to expand their network capabilities, whereas the femtocell owner would prefer closed access, in order to keep the femtocell's capacity and backhaul to himself. We show mathematically and through simulations that the reality is more complicated for both parties, and that the best approach depends heavily on whether the multiple access scheme is orthogonal (TDMA or OFDMA, per subband) or non-orthogonal (CDMA). In a TDMA/OFDMA network, closed-access is typically preferable at high user densities, whereas in CDMA, open access can provide gains of more than 300% for the home user by reducing the near-far problem experienced by the femtocell. The results of this paper suggest that the interests of the femtocell owner and the network operator are more compatible than typically believed, and that CDMA femtocells should be configured for open access whereas OFDMA or TDMA femtocells should adapt to the cellular user density.
Three-dimensional structured networks for matrix equation solving

Two three-dimensional structured networks are developed for solving linear equations and the Lyapunov equation. The basic idea of the structured network approaches is to first represent a given equation-solving problem by a 3-D structured network so that if the network matches a desired pattern array, the weights of the linear neurons give the solution to the problem: then, train the 3-D structured network to match the desired pattern array using some training algorithms; and finally, obtain the solution to the specific problem from the converged weights of the network. The training algorithms for the two 3-D structured networks are proved to converge exponentially fast to the correct solutions. Simulations were performed to show the detailed convergence behaviors of the 3-D structured networks. >
Opportunity Cost Consideration

Normatively, consumers should incorporate opportunity costs into every decision they make, yet behavioral research suggests that consumers consider them rarely, if at all. This research addresses when consumers consider opportunity costs, who considers opportunity costs, which opportunity costs spontaneously spring to mind, and what the consequences of considering opportunity costs are. Perceived constraints cue consumers to consider opportunity costs, and consumers high in propensity to plan consider opportunity costs even when not cued by immediate constraints. The specific alternatives retrieved and the likelihood of retrieval are functions of category structures in memory. For a given resource, some uses are more typical of the category of possible uses and so are more likely to be considered as opportunity costs. Consumers who consider opportunity costs are less likely to buy focal options than those who do not when opportunity costs are appealing, but no less likely when opportunity costs are unappe...
ECO-system: Embracing the Change in Placement

In a realistic design flow, circuit and system optimizations must interact with physical aspects of the design. For example, improvements in timing and power may require replacing large modules with variants that have different power/delay trade-off, shape and connectivity. New logic may be added late in the design flow, subject to interconnect optimization, To support such flexibility in design flows we develop a robust system for performing engineering change orders (ECOs). In contrast with existing stand-alone tools that offer poor interfaces to the design flow and cannot handle a full range of modern VLSI layouts, our ECO-system reliably handles fixed objects and movable macros in instances with widely varying amounts of whitespace. It detects geometric regions and sections of the netlist that require modification and applies an adequate amount of change in each case. Given a reasonable initial placement, it applies minimal changes, but is capable of re-placing large regions to handle pathological cases. ECO-system can be used in the range from high-level synthesis, to physical synthesis and detail placement.
Cluster mass estimators from CMB temperature and polarization lensing

Upcoming Sunyaev–Zel'dovich surveys are expected to return ~104 intermediate mass clusters at high redshift. Their average masses must be known to the same accuracy as desired for the dark energy properties. Internal to the surveys, the cosmic microwave background (CMB) potentially provides a source for lensing mass measurements whose distance is precisely known and behind all clusters. We develop statistical mass estimators from six quadratic combinations of CMB temperature and polarization fields that can simultaneously recover large-scale structure and cluster mass profiles. The performance of these estimators on idealized Navarro–Frenk–White (NFW) clusters suggests that surveys with a ~1' beam and noise in uncontaminated temperature maps can make a ~10σ detection, or equivalently a ~10% mass measurement for each 103 set of clusters. With internal or external acoustic scale E-polarization measurements, the ET cross-correlation estimator can provide a stringent test for contaminants on a first detection at ~1/3 the significance. For surveys that reach below , the EB cross-correlation estimator should provide the most precise measurements and potentially the strongest control over contaminants.
The adaptive mesh model: a new approach to efficient option pricing

Abstract Most derivative securities must be priced by numerical techniques. These models contain “distribution error” and “nonlinearity error”. The Adaptive Mesh Model (AMM) sharply reduces nonlinearity error by grafting one or more small sections of fine high-resolution lattice onto a tree with coarser time and price steps. Three different AMM structures are presented, one for pricing ordinary options, one for barrier options, and one for computing delta and gamma efficiently. The AMM approach can be adapted to a wide variety of contingent claims. For some common problems, accuracy increases by several orders of magnitude with no increase in execution time.
Incremental reconstruction of 3D scenes from multiple, complex images

Abstract The 3D Mosaic system is a vision system that incrementally reconstructs complex 3D scenes from a sequence of images obtained from multiple viewpoints. The system encompasses several levels of the vision process, starting with images and ending with symbolic scene descriptions. This paper describes the various components of the system, including stereo analysis, monocular analysis, and constructing and updating the scene model. In addition, the representation of the scene model is described. This model is intended for tasks such as matching, display generation, planning paths through the scene, and making other decisions about the scene environment. Examples showing how the system is used to interpret complex aerial photographs of urban scenes are presented. Each view of the scene, which may be either a single image or a stereo pair, undergoes analysis which results in a 3D wire-frame description that represents portions of edges and vertices of objects. The model is a surface-based description constructed from the wire frames. With each successive view, the model is incrementally updated and gradually becomes more accurate and complete. Task-specific knowledge, involving block-shaped objects in an urban scene, is used to extract the wire frames and construct and update the model. The model is represented as a graph in terms of symbolic primitives such as faces, edges, vertices, and their topology and geometry. This permits the representation of partially complete, planar-faced objects. Because incremental modifications to the model must be easy to perform, the model contains mechanisms to (1) add primitives in a manner such that constraints on geometry imposed by these additions are propagated throughout the model, and (2) modify and delete primitives if discrepancies arise between newly derived and current information. The model also contains mechanisms that permit the generation, addition, and deletion of hypotheses for parts of the scene for which there is little data.
Practice management issues in office-based anesthesiology

Office-based anesthesiology (OBA) presents an opportunity for some anesthesiology practices to expand their scope and garner professional and financial growth opportunities. Practices that center their OBA feasibility analysis on their mission and objectives stand to be the most successful whether or not they decide to pursue an OBA venture. The steps in evaluating the risk/benefit of entry into OBA include a complete analysis of the anesthesiology practice's mission and resources, and an evaluation of the prospective office site to assure it offers a safe and financially viable practice venue. An effective OBA implementation plan deals with the attendant legal and regulatory requirements, a client satisfaction program, and development of an administrative infrastructure to support and monitor the success of the venture as defined by the practice's mission-based objectives.
Negotiating Complex Contracts

Work to date on computational models of negotiation has focused almost exclusively on defining contracts consisting of one or a few independent issues. Many real-world contracts, by contrast, consist of multiple inter-dependent issues. This paper describes a simulated annealing based approach appropriate for negotiating such complex contracts, evaluates its efficacy, and suggests potentially promising avenues for future work.
The Association between LIFO Reserve and Equity Risk: An Empirical Assessment

This study examines the association between a firm's LIFO reserve and its equity risk. We hypothesize that LIFO reserve has favorable implications for equity risk as it confers tax benefits and represents unbooked profits, which prompt firms to lower their borrowings and effectively increase equity. Consistent with this hypothesis, we document a negative association between LIFO reserve and two measures of risk: standard deviation of stock returns and beta. We document a negative association between LIFO reserve and debt, consistent with the proposition that UFO reserve and debt are tax shield substitutes. However, the negative association between LIFO reserve and equity risk remains even when the level of debt of firms is controlled. Further tests show that adjusting the denominator of the debt-equity ratio for LIFO reserve improves its explanatory power with regard to risk, consistent with the notion that LIFO reserve is viewed as a component of equity in assessing risk. Additional tests indicate that L...
Deformations of Local Systems and Eisenstein Series

Let $X$ be a (smooth and complete) curve and $G$ a reductive group. In [BG] we introduced the object that we called "geometric Eisenstein series". This is a perverse sheaf $\bar{Eis}_E$ (or rather a complex of such) on the moduli stack $Bun_G(X)$ of principal $G$-bundles on $X$, which is attached to a local system $E$ on $X$ with respect to the torus $\check{T}$, Langlands dual to the Cartan subgroup $T\subset G$. In loc. cit. we showed that$\bar{Eis}_E$ corresponds to the $\check{G}$-local system induced from $E$, in the sense of the geometric Langlands correspondence. In the present paper we address the following question, suggested by V. Drinfeld: what is the perverse sheaf on $Bun_G(X)$ that corresponds to the universal deformation of $E$ as a local system with respect to the Borel subgroup $\check{B}\subset \check{G}$? We prove, following a conjecture of Drinfeld, that the resulting perverse sheaf if the classical, i.e., non-compactified Eisenstein series.
Glycosylation under Thermodynamic Control: Synthesis of the Di- and the Hexasaccharide Fragments of the O-SP of Vibrio Cholerae O:1 Serotype Ogawa from Fully Functionalized Building Blocks

The known 5-(methoxycarbonyl)pentyl α-glycoside of the hexasaccharide of the O-SP of Vibrio cholerae O:1, serotype Ogawa 31 was newly prepared from side-chain-equipped disaccharide building blocks. The intermediate tetrasaccharide 25 was prepared from the disaccharide glycosyl acceptor 11 and the (12)-linked disaccharide thioglycoside glycosyl donor 8, having a (non-participating) saccharide moiety at C-2 in the downstream end. When performed conventionally (at room or at sub 0 °C temperatures), glycosylations with 11, carried out without anchimeric assistance, showed poor stereoselectivity but the formation of the 1,2-trans-glycosidic linkage could be markedly improved through thermodynamic control. This synthetic strategy towards 31 was more efficient than the step-wise approach, which was based
Catalysis by aluminum(III) complexes of non-innocent ligands.

Non-Innocent ligand complexes of aluminum are described in this Concept article, beginning with a discussion of their synthesis, and then structural and electronic characterization. The main focus concerns the ability of the ligands in these complexes to mediate proton transfer reactions. As examples, aluminum–ligand cooperation in the activation of polar bonds is described, as is the importance of hydrogen bonding to stabilization of a transition state for β-hydride abstraction. Taken together these reactions enable catalytic processes such as the dehydrogenation of formic acid.
A high rate, low noise, X-ray silicon strip detector system

An X-ray detector system, based on a silicon strip detector wire-bonded to a low noise charge-sensitive amplifier integrated circuit, has been developed for synchrotron radiation experiments which require very high count rates and good energy resolution. Noise measurements and X-ray spectra were taken using a 6 mm long, 55 /spl mu/m pitch strip detector in conjunction with a prototype 16-channel charge-sensitive preamplifier, both fabricated using standard 1.2 /spl mu/m CMOS technology. The detector system currently achieves an energy resolution of 350 eV FWHM at 5.9 keV, 2 /spl mu/s peaking time, when cooled to -5/spl deg/C. >
Effects on galaxy evolution: pair interactions versus environment

In a hierarchical universe, mergers may be an important mechanism not only in increasing the mass of galaxies but also in driving the colour and morphological evolution of galaxies. We use a large sample of ∼1000 simulated galaxies of stellar mass greater than 109.6 M⊙ (for ∼4800 observations at multiple redshifts) from a high-resolution (0.46 h−1 kpc) cosmological simulation to determine under what circumstances being a member of a pair influences galaxy properties at z ≤ 0.2. We identify gravitationally bound pairs, and find a relative fraction of blue–blue (wet), red–red (dry) and blue–red (mixed) pairs that agrees with observations. All pairs tend to avoid the extreme environments of clusters and void centres. While pairs in groups can include galaxies that are both blue, both red, or one of each colour, in the field it is extraordinarily rare for pair galaxies to both be red. We find that physically bound pairs closer than 250 h−1 kpc tend to have higher specific star formation rates (sSFRs) than the galaxy population as a whole. However, the sSFR of a bound galaxy relative to galaxies in a comparable local density environment (determined by the distance to the fifth nearest neighbour, ρ5) differs depending on the local density. In regions of high ρ5 the bound population has a higher fraction of star-forming (bluer) galaxies, whereas there is very little difference between bound and unbound galaxies in low ρ5 regions. This effect on the star-forming fraction may be driven by the higher fraction of bound H i-rich galaxies compared to unbound galaxies, particularly at high local densities. It appears that being in a pair has an incremental, but not overwhelming, effect on the star formation rate of the paired galaxies, compared to the more pronounced trend where galaxies overall have low sSFR (red) in clusters and higher sSFR (blue) at the centre of voids. This trend depends most strongly on local galaxy density (ρ5). We find no strong evidence that pair interactions are the driver of the colour–density relation for galaxies.
Rovelli’s World

Carlo Rovelli’s inspiring “Relational Quantum Mechanics” serves several aims at once: it provides a new vision of what the world of quantum mechanics is like, and it offers a program to derive the theory’s formalism from a set of simple postulates pertaining to information processing. I propose here to concentrate entirely on the former, to explore the world of quantum mechanics as Rovelli depicts it. It is a fascinating world in part because of Rovelli’s reliance on the information-theory approach to the foundations of quantum mechanics, and in part because its presentation involves taking sides on a fundamental divide within philosophy itself.
A Split-Coefficient/Locally Monotonic Scheme for Multishocked Supersonic Flow

A new finite-difference technique is developed for solving three-dimensional, steady, in viscid, supersonic, equilibrium real-gas flows with embedded shock waves. The technique employs the split-coefficient matrix (SCM) method to solve the gasdynamic equations in the form of decoupled compatibility relations. In the SCM technique the coefficient matrices are split according to the sign of their eigenvalues. The derivatives associated with each split-coefficient matrix are approximated by one-sided difference operators consistent with signal propagation paths. The results demonstrate that problems of conventional finite-difference methods with nonorthogonal grids are alleviated in the SCM approach. In addition, the solutions obtained using the SCM technique show that strong crossflow gradients, including crossflow shocks, can be accurately computed. To treat flows containing embedded stream wise shock waves the SCM technique is replaced, at grid points detected to be in the vicinity of a shock, by the monotonic self-adjusting hybrid/artificial compression method (ACM). The governing equations are cast in conservation law form in the shock-capturing ACM approach with damping terms added to eliminate postshock oscillations. Streamwise shocks of sufficient strength to cause conventional shock-capturing methods to fail are resolved using the combined SCM/ACM technique.
Return-to-Work Outcomes Among Social Security Disability Insurance Program Beneficiaries

We followed a sample of working-age Social Security Disability Insurance (DI) program beneficiaries for 5 years after their first benefit award to learn how certain factors are associated with achi...
America, Defender of Democratic Legitimacy?

American exceptionalism — a belief that the United States has a unique mission to lead the world, but ought logically to be exempt from the rules it promotes — is at the root of much of the American academy's effort to rationalize the US government's increasing rejection of multilateralism as the cornerstone of modern public international law. Even American scholars who disagree fundamentally on the problems with multilateralism (Kenneth Anderson arguing that it favours anti-democratic intervention by unelected NGOs, Michael Reisman asserting that it privileges elitist state-based lawmaking in the face of more democratic non-state 'lawmaking' processes) can agree on the solution: more unilateralism by powerful states, particularly by the United States. In this critique, James Hathaway contends that the amorphous law-as-policy depictions of the problems with multilateralism disguise a determination to equate valid international law with the priorities of powerful states, and that the presumed solution of American unilateralism reflects a mistaken belief that the United States can be assumed always to operate on the basis of principle-derived autopilot. There is a restlessness in much of the American academy with the central place afforded multilateralism in modern public international law. The assault on multilateralism may be framed boldly, as in Allan Gerson's unapologetic assertion of the right of powerful states to invoke political concerns to trump formal legal commitments. 1 It may also be framed as a studiously earnest call to reconsider the virtues of unilaterialism, as exemplified by Jose Alvarez's feigned disbelief that international lawyers could for so long have been unthinking participants in a 'semi-religious crusade on behalf of internationalist agendas'. 2 Neither of these approaches seems to me to be a helpful means of coming to grips with the real dilemma
R/qtlcharts: Interactive Graphics for Quantitative Trait Locus Mapping

Every data visualization can be improved with some level of interactivity. Interactive graphics hold particular promise for the exploration of high-dimensional data. R/qtlcharts is an R package to create interactive graphics for experiments to map quantitative trait loci (QTL) (genetic loci that influence quantitative traits). R/qtlcharts serves as a companion to the R/qtl package, providing interactive versions of R/qtl’s static graphs, as well as additional interactive graphs for the exploration of high-dimensional genotype and phenotype data.
Implications of Growth in China for the U.S. and Other Countries

We investigate the effects of China's economic growth on various sectors in the United States and other countries and regions, using a multi-region Global Trade Analysis Project (GTAP) model. The results indicate that all countries and regions, except South Korea and South Asian countries, would benefit from China's rapid economic growth. The welfare gain varies significantly across the countries and regions. Hong Kong and Taiwan would benefit the most from mainland China's economic growth in terms of per capita welfare gains. U.S. bilateral trade balance with China would improve in the sectors of grain and other primary agricultural products, but it would deteriorate in the sectors of textiles and high-tech manufacturing products.
Optimal Placement of Distributed Energy Storage in Power Networks

We formulate the optimal placement, sizing and control of storage devices in a power network to minimize generation costs with the intent of load shifting. We assume deterministic demand, a linearized DC approximated power flow model and a fixed available storage budget. Our main result proves that when the generation costs are convex and nondecreasing, there always exists an optimal storage capacity allocation that places zero storage at generation-only buses that connect to the rest of the network via single links. This holds regardless of the demand profiles, generation capacities, line-flow limits and characteristics of the storage technologies. Through a counterexample, we illustrate that this result is not generally true for generation buses with multiple connections. For specific network topologies, we also characterize the dependence of the optimal generation cost on the available storage budget, generation capacities and flow constraints.
Segmenting Point Sets

Extracting features from point sets is becoming increasingly important for purposes like model classification, matching, and exploration. We introduce a technique for segmenting a point-sampled surface into distinct features without explicit construction of a mesh or other surface representation. Our approach achieves computational efficiency through a three-phase segmentation process. The first phase of the process uses a topo-logical approach to define features and coarsens the input, resulting in a set of supernodes, each one representing a collection of input points. A graph cut is employed in the second phase to bisect the set of supernodes. Similarity between supernodes is computed as a weighted combination of geodesic distances and connectivity. Repeated application of the graph cut results in a hierarchical segmentation of the point input. In the last phase, a segmentation of the original point set is constructed by refining the segmentation of the supernodes based on their associated feature sizes. We apply our segmentation algorithm on laser-scanned models to evaluate its ability to capture geometric features in complex data sets
CLAM- an open system for graphical user interfaces

CLAM is an object-oriented system designed to support the building of extensible graphical user interfaces. CLAM provides a basic windowing environment with the ability to extend its functions using dynamically loaded C++ classes. The dynamically loaded classes allow for performance tuning (by transparently loading the class in either the client or the CLAM server) and for sharing of new functions.In addition to the traditionally layering of output abstractions, CLAM allows the programmer to easily layer input abstractions. The input functions include providing distributed upward calls through the layers, an light weight processes to support asynchronous input.CLAM is currently running under 4.3BSD UNIX on a MicroVax-II workstation.
Lutz–Kelker bias in pulsar parallax measurements

Lutz and Kelker showed that parallax measurements are systematically overestimated because they do not properly account for the larger volume of space that is sampled at smaller parallax values. We apply their analysis to neutron stars, incorporating the bias introduced by the intrinsic radio luminosity function and a realistic Galactic population model for neutron stars. We estimate the bias for all published neutron star parallax measurements and find that measurements with less than ∼95 per cent certainty are likely to be significantly biased. Through inspection of historic parallax measurements, we confirm the described effects in optical and radio measurements as well as in distance estimates based on interstellar dispersion measures. The potential impact on future tests of relativistic gravity through pulsar timing and on X-ray-based estimates of neutron star radii is briefly discussed.
Faulty Communication: Some Variations on the Electronic Mail Game

The electronic mail game of Rubinstein (1989) showed that a lack of common knowledge generated by faulty communication can make coordinated action impossible. This paper shows how this conclusion is robust to having a more realistic timing structure of messages, more than two players who meet publicly but not as a plenary group, and may be robust to strategic decisions about whether to communicate.
Personality Traits and the Consumption of Political Information

In this article, we examine the relationship between dispositional personality traits (the Big Five) and the consumption of political information. We present detailed hypotheses about the characteristics of the political environment that are likely to affect the appeal of politics and political information in general for individuals with different personalities as well as hypotheses about how personality affects the attractiveness of particular sources of political information. We find that the Big Five traits are significant predictors of political interest and knowledge as well as consumption of different types of political media. Openness (the degree to which a person needs intellectual stimulation and variety) and Emotional Stability (characterized by low levels of anxiety) are associated with a broad range of engagement with political information and political knowledge. The other three Big Five traits, Conscientiousness, Agreeableness, and Extraversion, are associated only with consumption of specif...
Resisting the Canon: Feminist Cultural Studies, Sport, and Technologies of the Body

In this paper, I argue that contemporary critical theories as well as shifts in culture have produced a crisis in sport studies by displacing and challenging the "object of knowledge" as it has bee...
NANOMETER SCALE SPONTANEOUS VIBRATIONS IN A DEPLOYABLE TRUSS UNDER MECHANICAL LOADING

Evidence is reported of spontaneous vibrations of a deployable spacecraft structure at optical levels of motion under mechanical loads. In these experiments a truss was mechanically loaded while in a thermally and vibrationally stabilized test environment. The applied loads were smaller, by a factor of 20, than the load that would have caused gross slippage in the frictional interfaces of the structure. Even so, results indicate that infrequent, spontaneous vibrations occurred. Most of these vibrations occurred after the application and removal of a mechanical load. The response spectra of the vibrations occurred in narrow bandwidths around the dominant modal frequencies of the structure. The vibrations ranged in amplitude from 4 to 20 nm and in velocity from 2 to 8 μ/s. Potential error sources are eliminated, including unmeasured environmental excitations and sensor errors. These vibrations are presumed to arise from the sudden release of strain energy stored in the hysteretic mechanisms and materials of the structure. An analysis based on this hypothesis shows that the amplitude of the observed vibrations is quantitatively consistent with this theory.
An Economic Framework for Forecasting Land-Use and Ecosystem Change

11/26/08 Abstract: This paper develops a joint econometric-simulation framework to forecast detailed empirical distributions of the spatial pattern of land-use and ecosystem change. In-sample and out-of-sample forecasting tests are used to examine the performance of the parcel-scale econometric and simulation models, and the importance of multiple forecasting challenges is assessed. The econometric-simulation method is integrated with an ecological model to generate forecasts of the probability of localized extinctions of an amphibian species. The paper demonstrates the potential of integrating economic and ecological models to generate ecological forecasts in the presence of alternative market conditions and land-use policy constraints.
Sketching and Streaming Entropy via Approximation Theory

We give near-optimal sketching and streaming algorithms for estimating Shannon entropy in the most general streaming model, with arbitrary insertions and deletions. This improves on prior results that obtain suboptimal space bounds in the general model, and near-optimal bounds in the insertion-only model without sketching. Our high-level approach is simple: we give algorithms to estimate Tsallis entropy, and use them to extrapolate an estimate of Shannon entropy. The accuracy of our estimates is proven using approximation theory arguments and extremal properties of Chebyshev polynomials. Our work also yields the best-known and near-optimal additive approximations for entropy, and hence also for conditional entropy and mutual information.
Evaluation of model-simulated source contributions to tropospheric ozone with aircraft observations in the factor-projected space

Trace gas measurements of TOPSE and TRACE- P experiments and corresponding global GEOS-Chem model simulations are analyzed with the Positive Matrix Factoriza- tion (PMF) method for model evaluation purposes. Specially, we evaluate the model simulated contributions to O3 vari- ability from stratospheric transport, intercontinental trans- port, and production from urban/industry and biomass burn- ing/biogenic sources. We select a suite of relatively long- lived tracers, including 7 chemicals (O3, NOy, PAN, CO, C3H8, CH3Cl, and 7 Be) and 1 dynamic tracer (potential tem- perature). The largest discrepancy is found in the strato- spheric contribution to 7 Be. The model underestimates this contribution by a factor of 2-3, corresponding well to a re- duction of 7 Be source by the same magnitude in the default setup of the standard GEOS-Chem model. In contrast, we find that the simulated O 3 contributions from stratospheric transport are in reasonable agreement with those derived from the measurements. However, the springtime increasing trend over North America derived from the measurements are largely underestimated in the model, indicating that the magnitude of simulated stratospheric O3 source is reasonable but the temporal distribution needs improvement. The sim- ulated O3 contributions from long-range transport and pro- duction from urban/industry and biomass burning/biogenic emissions are also in reasonable agreement with those de- rived from the measurements, although significant discrep- ancies are found for some regions.
The equity premium: a deeper puzzle

Traditional pre-1929 consumption measures understate the extent of serial correlation in the US annual real growth rate of per capita consumption of non-durables and services due to measurement limitations in the construction of their major components. Under alternative measures proposed in this study, the serial correlation of consumption growth is $$0.42$$ for the $$1899$$ – $$2012$$ , contrary to the estimate of $$-0.15$$ under the traditional measures. This new evidence implies that the class of economies studied by Mehra and Prescott (J Monet Econ 15(2):145–161, 1985) generates a negative equity premium for reasonable risk aversion levels, thus, further exacerbating the equity premium puzzle.
Energy extraction from boosted black holes: Penrose process, jets, and the membrane at infinity

Numerical simulations indicate that black holes carrying linear momentum and/or orbital momentum can power jets. The jets extract the kinetic energy stored in the black hole's motion. This could provide an important electromagnetic counterpart to gravitational wave searches. We develop the theory underlying these jets. In particular, we derive the analogues of the Penrose process and the Blandford-Znajek jet power prediction for boosted black holes. The jet power we find is $(v/2M{)}^{2}{\mathrm{\ensuremath{\Phi}}}^{2}/(4\ensuremath{\pi})$, where $v$ is the hole's velocity, $M$ is its mass, and $\mathrm{\ensuremath{\Phi}}$ is the magnetic flux. We show that energy extraction from boosted black holes is conceptually similar to energy extraction from spinning black holes. However, we highlight two key technical differences: in the boosted case, jet power is no longer defined with respect to a Killing vector, and the relevant notion of black hole mass is observer dependent. We derive a new version of the membrane paradigm in which the membrane lives at infinity rather than the horizon and we show that this is useful for interpreting jets from boosted black holes. Our jet power prediction and the assumptions behind it can be tested with future numerical simulations.
Library fingerprints: a novel approach to the screening of virtual libraries.

We propose a novel method to prioritize libraries for combinatorial synthesis and high-throughput screening that assesses the viability of a particular library on the basis of the aggregate physical-chemical properties of the compounds using a naive Bayesian classifier. This approach prioritizes collections of related compounds according to the aggregate values of their physical-chemical parameters in contrast to single-compound screening. The method is also shown to be useful in screening existing noncombinatorial libraries when the compounds in these libraries have been previously clustered according to their molecular graphs. We show that the method used here is comparable or superior to the single-compound virtual screening of combinatorial libraries and noncombinatorial libraries and is superior to the pairwise Tanimoto similarity searching of a collection of combinatorial libraries.
Efficiently computing and representing aspect graphs of polyhedral objects

An efficient algorithm and a data structure for computing and representing the aspect graph of polyhedral objects under orthographic projection are presented. The aspect graph is an approach to representing 3-D objects by a set of 2-D views, for the purpose of object recognition. In this approach the viewpoint space is partitioned into regions such that in each region the qualitative structure of the line drawing does not change. The viewing data of an object is the partition of the viewpoint space together with a representative view in each region. The algorithm computes the viewing data for line drawings of polyhedral objects under orthographic projection. >
Quantum quivers and Hall / hole halos

Two pictures of BPS bound states in Calabi-Yau compactifications of type II string theory exist, one as a set of particles at equilibrium separations from each other, the other as a fusion of D-branes at a single point of space. We show how quiver quantum mechanics smoothly interpolates between the two, and use this, together with recent mathematical results on the cohomology of quiver varieties, to solve some nontrivial ground state counting problems in multi-particle quantum mechanics, including one arising in the setup of the spherical quantum Hall effect, and to count ground state degeneracies of certain dyons in supersymmetric Yang-Mills theories. A crucial ingredient is a non-renormalization theorem in N = 4 quantum mechanics for the first order part of the Lagrangian in an expansion in powers of velocity.
Defect Structure and Dielectric Properties of Nd2O3-Modified BaTiO3

The defect structure and dielectric properties of BaTiO3 with 1 to 10 mol% Nd2O3 additions were studied. The results indicated that neodymium occupies the barium site and charge compensation takes place by creation of titanium vacancies. The dependence of inverse electric susceptibility, spontaneous polarization, and specific heat on temperature for samples containing more than 2 mol% of Nd2O3 were characteristic of a diffuse transformation resulting from a disordering of defects. The addition of Nd2O3 leads to a very drastic sfiift in the Curie temperature (Tc) of BaTiO3; 3 mel% Nd2O3 addition moves Tc below room temperature.
Three-dimensional atmospheric entry problem using method of matched asymptotic expansions

A composite solution consisting of an outer solution, an inner solution, and a common solution is obtained. The outer solution arises from the gravitationally dominant region, whereas the aerodynamically dominant region contributes to the inner solution. The common solution accounts for the overlap between the outer and inner regions. In contrast to previous work, this simplified methodology yields explicit analytical expressions for various compounds of the composite solution without resorting to any type of transcendental equation that can be solved only by numerical methods. The present method is application for obtained autonomous guides and control strategies for a variety of aerospace vehicles. >
Multidimensional coherent photocurrent spectroscopy of a semiconductor nanostructure

Multidimensional Coherent Optical Photocurrent Spectroscopy (MD-COPS) is implemented using unstabilized interferometers. Photocurrent from a semiconductor sample is generated using a sequence of four excitation pulses in a collinear geometry. Each pulse is frequency shifted by a unique radio frequency through acousto-optical modulation; the Four-Wave Mixing (FWM) signal is then selected in the frequency domain. The interference of an auxiliary continuous wave laser, which is sent through the same interferometers as the excitation pulses, is used to synthesize reference frequencies for lock-in detection of the photocurrent FWM signal. This scheme enables the partial compensation of mechanical fluctuations in the setup, achieving sufficient phase stability without the need for active stabilization. The method intrinsically provides both the real and imaginary parts of the FWM signal as a function of inter-pulse delays. This signal is subsequently Fourier transformed to create a multi-dimensional spectrum. Measurements made on the excitonic resonance in a double InGaAs quantum well embedded in a p-i-n diode demonstrate the technique.
Learning Parameterized Skills

We introduce a method for constructing skills capable of solving tasks drawn from a distribution of parameterized reinforcement learning problems. The method draws example tasks from a distribution of interest and uses the corresponding learned policies to estimate the topology of the lower-dimensional piecewise-smooth manifold on which the skill policies lie. This manifold models how policy parameters change as task parameters vary. The method identifies the number of charts that compose the manifold and then applies non-linear regression in each chart to construct a parameterized skill by predicting policy parameters from task parameters. We evaluate our method on an underactuated simulated robotic arm tasked with learning to accurately throw darts at a parameterized target location.
Will the Federal Reserve Monetize U.S. Government Debt

Purchases of U.S. Treasury securities by the U.S. Federal Reserve in 2009 have prompted concerns that the Fed may monetize debt issued by the federal government, an act with potentially inflationary consequences. Whether such concerns are warranted depends in large part on the amount of Treasury securities the Fed purchases. So long as the Fed’s total ownership of Treasury securities does not exceed the amount of currency in circulation, the Federal Reserve will not be monetizing the federal government’s debt.
Organometallic Photonucleases: Synthesis and DNA-Cleavage Studies of Cyclopentadienyl Metal-Substituted Dendrimers Designed To Increase Double-Strand Scission

A series of metal complex-substituted polyamine dendrimers have been synthesized and examined for their ability to cleave plasmid DNA in a double-stranded manner. While photolysis of the dimetallic spermine derivative and the tetrametallic DAB-Am-4 complex led to double-strand scission, in the larger DAB-Am-8 and DAB-Am-16 systems, DNA aggregation/precipitation was the predominant competing process observed.
Copper Salt-Catalyzed Azide-[3 + 2] Cycloadditions of Ynamides and Bis-Ynamides

A one-pot synthesis of amide-substituted triazoles from alkyl bromides and ynamides is described here along with syntheses of novel bis-ynamides and their applications in [3+2] cycloadditions with azides to construct unique bis-triazoles.
Revisiting the Paxos Algorithm

The Paxos algorithm is an efficient and highly fault-tolerant algorithm, devised by Lamport, for reaching consensus in a distributed system. Although it appears to be practical, it seems to be not widely known or understood. This thesis contains a new presentation of the Paxos algorithm, based on a formal decomposition into several interacting components. It also contains a correctness proof and a time performance and fault-tolerance analysis. The presentation is built upon a general timed automaton (GTA) model. The correctness proof uses automaton composition and invariant assertion methods. The time performance and fault-tolerance analysis is conditional on the stabilization of the underlying physical system behavior starting from some point in an execution. In order to formalize this stabilization, a special type of GTA called a Clock GTA is defined.
How much of the web is archived

The Memento Project's archive access additions to HTTP have enabled development of new web archive access user interfaces. After experiencing this web time travel, the in- evitable question that comes to mind is "How much of the Web is archived?" This question is studied by approximating the Web via sampling URIs from DMOZ, Delicious, Bitly, and search engine indexes and measuring number of archive copies available in various public web archives. The results indicate that 35%-90% of URIs have at least one archived copy, 17%-49% have two to five copies, 1%-8% have six to ten copies, and 8%-63% at least ten copies. The number of URI copies varies as a function of time, but only 14.6-31.3% of URIs are archived more than once per month.
A Frattini Theory for Leibniz Algebras

A Frattini theory for non-associative algebras was developed in [13] and results for particular classes of algebras have appeared in various articles. Especially plentiful are results on Lie algebras. It is the purpose of this paper to extend some of the Lie algebra results to Leibniz algebras.
Faster numerical algorithms via exception handling

An attractive paradigm for building fast numerical algorithms is the following: 1) try a fast but occasionally unstable algorithm, 2) test the accuracy of the computed answer, and 3) recompute the answer slowly and accurately in the unlikely event it is necessary. This is especially attractive on parallel machines where the fastest algorithms may be less stable than the best serial algorithms. Since unstable algorithms can overflow or cause other exceptions, exception handling is needed to implement this paradigm safely. To implement it efficiently, exception handling cannot be too slow. We illustrate this paradigm with numerical linear algebra algorithms from the LAPACK library. >
Optimal Fiscal Policy with Robust Control

Abstract This paper analyzes how consumer uncertainty affects optimal fiscal policy in the Lucas and Stokey (1983) framework. The consumers, lacking confidence in their knowledge of the stochastic environment, endogenously tilt their subjective probability model away from an approximating probability model. The government, though, is confident that the approximating probability model characterizes the stochastic environment. This confidence dichotomy reveals a range of possible objective functions for an altruistic government. I assume that the government maximizes the consumers' expected utility under the consumers' own subjective probability model. It is found that this government relies less heavily on labor taxes to absorb the fiscal shock than would be optimal if consumers were fully confident in their probability model. This policy helps mitigate the direct welfare cost associated with consumer uncertainty. I compare this policy to the one implemented by a government that maximizes the consumers' expected utility under the approximating probability model.
Aeff-enlarged pure-silica-core fiber having ring-core profile

Pure-silica-core fiber with ring-core profile is designed to have the larger ratio of Aeff to MFD than with step-core, and realized Aeff of 135μm2 and transmission loss of 0.160dB/km with improved splicing loss onto SSMF.