cssi/SciSciGPT-SciSciNet huggingface dataset:
Active self-sensing scheme development for structural health monitoring

Smart materials such as lead zirconate titanate (PZT) have been widely used for generating and measuring guided waves in solid media. The guided waves are then used to detect local defects for structural health monitoring (SHM) applications. In this study, a self-sensing system, composed of self-sensing algorithms and a self-sensing circuit equivalent to a charge amplifier, is developed so that a single PZT wafer can be used for simultaneous actuation and sensing. First, a PZT wafer is modeled as a single capacitor and a voltage source, and a so-called scaling factor, defined as the ratio of the PZT capacitance to the capacitance of the feedback capacitor in the self-sensing circuit, is estimated by applying known waveforms to the PZT wafer. Then, the mechanical response of the PZT wafer coupled with the host structure's response is extracted from the measured PZT output voltage when an arbitrary excitation is applied to the same PZT wafer. While existing self-sensing techniques focus on vibration controls, the proposed self-sensing scheme attempts to improve the accuracy of extracted sensing signals in the time domain. The simplicity, adaptability and autonomous nature of the proposed self-sensing scheme make it attractive for continuous monitoring of structures in the field. The effectiveness of the proposed self-sensing scheme is investigated through numerical simulations and experiments on a cantilever beam.
DEMAND SYSTEMS WITH NONSTATIONARY PRICES

Relative prices are nonstationary and standard root-T inference is invalid for demand systems. But demand systems are nonlinear functions of relative prices, and standard methods for dealing with nonstationarity in linear models cannot be used. Demand system residuals are also frequently found to be highly persistent, further complicating estimation and inference. We propose a variant of the translog demand system, the NTLOG, and an associated estimator that can be applied in the presence of nonstationary prices with possibly nonstationary errors. The errors in the NTLOG can be interpreted as random utility parameters. The estimates have classical root-T limiting distributions. We also propose an explanation for the observed nonstationarity of aggregate demand errors, based on aggregation of consumers with heterogeneous preferences in a slowly changing population. Estimates using U.S. data are provided.
Unfaulting and unfolding 3D seismic images

ABSTRACTIdentifying and extracting geologic horizons is useful for interpretation of stratigraphic features as well as analysis of structural deformation. To extract horizons from a seismic image, we developed methods for automatically unfaulting and unfolding an image to restore all horizons to an undeformed, horizontal state. First, using fault surfaces and dip-separation vectors estimated from an image, we interpolated dip-separation vectors at locations between fault surfaces, and then we used the interpolated dip-separation vectors to unfault an image. Then, using a method for automatic seismic image flattening, we unfolded the unfaulted image to obtain a new image in which sedimentary layering is horizontal and also aligned across faults. From this unfaulted and unfolded image, we automatically extracted geologic horizons.
Robust control of nonlinear systems by estimating time variant uncertainties

In this paper, robust control design is considered for nonlinear systems with time-variant uncertainties. Instead of assuming that the bounding function on uncertainties is either known or parameterizable in terms of unknown constants, uncertainties or their bounding functions are estimated. It is shown that bounded uncertainties from a known or partially known exo-system can be estimated as a part of a globally stabilizing robust control. The proposed method extends the existing results of adaptive robust control, and it makes robust control more applicable by requiring less information on uncertainties.
A continuum theory of thermoelectric bodies and effective properties of thermoelectric composites

Abstract We develop a continuum theory for thermoelectric bodies following the framework of continuum mechanics and conforming to general principles of thermodynamics. For steady states, the governing equations for local fields are intrinsically nonlinear. However, under conditions of small variations of electrochemical potential, temperature and their gradients, the governing equations can be reduced to a linear elliptic system and conveniently solved to determine local fields in thermoelectric bodies. The linear theory is further applied to predict effective properties of thermoelectric composites. In particular, explicit formula of effective properties are obtained for simple microstructures of laminates and periodic E-inclusions, which imply useful design principles for engineering thermoelectric composites.
As real as real? Macroeconomic behavior in a large-scale virtual world:

This article proposes an empirical test of whether aggregate economic behavior maps from the real to the virtual. Transaction data from a large commercial virtual world — the first such data set provided to outside researchers — is used to calculate metrics for production, consumption and money supply based on real-world definitions. Movements in these metrics over time were examined for consistency with common theories of macroeconomic change. The results indicated that virtual economic behavior follows real-world patterns. Moreover, a natural experiment occurred, in that a new version of the virtual world with the same rules came online during the study. The new world's macroeconomic aggregates quickly grew to be nearly exact replicas of those of the existing worlds, suggesting that `Code is Law': macroeconomic outcomes in a virtual world may be explained largely by design structure.
On Bott-Chern forms and their applications

We use Chern–Weil theory for Hermitian holomorphic vector bundles with canonical connections for explicit computation of the Chern forms of trivial bundles with special non-diagonal Hermitian metrics. We prove that every \(\bar{\partial }\partial \)-exact real form of the type \((k,k)\) on an \(n\)-dimensional complex manifold \(X\) arises as a difference of the Chern character forms of trivial Hermitian vector bundles with canonical connections, and that modulo \(\mathrm {Im}\,\partial +\mathrm {Im}\,\bar{\partial }\) every real form of type \((k,k)\), \(k<n\), arises as a Bott–Chern form for two Hermitian metrics on some trivial vector bundle over \(X\). The latter result is a complex manifold analogue of Proposition 2.6 in the paper by Simons and Sullivan (Am Math Soc 11:579–599, 2010). As an application, we obtain an explicit formula for the Bott–Chern form of a short exact sequence of holomorphic vector bundles considered by Bott and Chern (Acta Math 114:71–112, 1965), for the case when the first term is a line bundle.
Geologic Mapping of Vesta from 1994 Hubble Space Telescope Images

We utilize the 56 images of Asteroid 4 Vesta obtained through four mineralogically diagnostic filters by the Hubble Space Telescope (Zellneret al.1997,Icarus) to construct a geologic map. Vesta's surface is found to be geologically diverse and to be dichotomous at a hemispheric scale. The eastern hemisphere (longitude definition from Thomaset al.1997,Icarus) is dominated by units interpreted to be impact excavated plutonic material composed of magnesium-rich and calcium-poor pyroxene. The mineralogy of this region is most analogous to diogenite meteorites. Several eastern hemisphere units which have the deepest and broadest 1 μm absorption bands may contain a substantial olivine component. The locations of these units are consistent with a previous map based on rotationally resolved groundbased spectroscopy (Gaffey 1997,Icarus). The western hemisphere is dominated by units interpreted to consist of a single component of iron-rich and relatively calcium-rich pyroxene, analogous to surface basalts such as eucrite meteorites. We investigate the spectral properties of 20 representative surface regions and find a correlation between the 1 μm absorption band depth and albedo: the units with lower albedos have shallower band depths. Such a relation could arise from differences in lithologies, differences in surface particle sizes, or from a weathering effect which decreases albedo and band depth over time. Because of Vesta's geologic diversity and hemispheric dichotomy, it is apparent that any major impact events, such as those possibly related to the formation of the Vesta family (Binzel and Xu 1993,Science260,186–191) did not globally resurface the planet. The spectral evidence for remnants of a basaltic crust implies that the oldest units on the surface date back to the time of their emplacement, most likely ∼4.5 byr ago. If a weathering process exists which alters the albedo, then the lowest albedo units, such as the feature with the proposed name “Olbers,” most likely represent remnants of Vesta's ancient basaltic crust.
The Correlation of Wealth Across Generations

In this paper, we find that the age‐adjusted elasticity of child wealth with respect to parental wealth is 0.37 before the transfer of bequests. Lifetime income and asset ownership jointly explain nearly two‐thirds of the wealth elasticity. Education, past parental transfers, and expected future bequests account for little of the remaining elasticity. Survey measures of risk correlate strongly between parents and children. However, they explain little of the intergenerational similarity in the propensity to own different assets, suggesting that children’s savings propensities are determined by mimicking their parents’ behavior, or the inheritance of preferences not related to risk tolerance. Our results imply that while parents do pass on human capital and saving propensities to their children, the level of intergenerational fluidity is much greater than that suggested by recent accounts in the popular press.
Structural characterization of the first hydrothermally synthesized plutonium compound, PuO2(IO3)2·H2O

Single crystals of PuO2(IO3)2 x H2O were synthesized under hydrothermal conditions (180 degrees C) representing the first structurally characterized transuranium iodate.
Potassium sodium tin selenide, K3NaSn3Se8

The title compound, tripotassium sodium tritin octaselenide, K3NaSn3Se8, has a molecular (zero-dimensional) structure containing trimeric [Sn3Se8]4− units which consist of three edge-sharing SnSe4 tetrahedra. The [Sn3Se8]4− anions and the tetrahedrally coordinated Na+ cations are arranged in an alternating fashion along the c axis to form SiS2-like chains, which are then separated by eight-coordinate K+ cations. The Sn—Se bond distances are normal, being in the range 2.477 (1)–2.612 (1) A.
Design of a high temperature oven for an ECR source for the production of uranium ion beams

VENUS is the superconducting electron cyclotron resonance (ECR) ion source at the Lawrence Berkeley National Lab's 88-Inch Cyclotron. To generate neutral atoms for ionization, the source utilizes a resistively- heated high temperature oven that is located in a magnetic field of up to 4 Tesla and operates at temperatures up to about 2000degC. However, temperatures between 2100- 2300degC are required to produce the desired 280 emuA of high charge state uranium ion beams, and increased thermal and structural effects, combined with elevated chemical reactivity significantly reduce the oven's ability to operate in this envelope. The oven has been redesigned with higher thermal efficiency, improved structural strength and chemically compatible species in order to produce the desired high intensity, high charge state uranium beams. Aspects of the engineering development are presented.
The Intraday Behavior of Bid-Ask Spreads for NYSE Stocks and CBOE Options

We study the intraday behavior of bid-ask spreads for actively traded CBOE options and for their NYSE-traded underlying stocks. We confirm previous findings that stocks have a U-shaped spread pattern; however, the options display a very different intraday pattern—one that declines sharply after the open, and then levels off. Our results suggest that both the degree of competition in market making and the extent of informed trading are important for understanding the intraday behavior of spreads.
Combined Pressure and Subcooling Effects on Pool Boiling From a PPGA Chip Package

This study presents a detailed experimental investigation of the combined effects of pressure and subcooling on nucleate pool boiling and critical heat flux (CHF) for degassed fluorocarbon FC-72 boiling on a plastic pin-grid-array (PPGA) chip package. In these experiments pressure was varied between 101.3 and 303.9 kPa and the subcooling ranged from 0 to 65°C. As expected, lower wall superheats resulted from increases in pressure, while subcooling had a minimal effect on fully developed pool boiling. However, the superheat reductions and CHF enhancements were found to be smaller than those predicted by existing models. The CHF for saturated liquid conditions increased by nearly 17 percent for an increase in pressure from 101.3 to 202.7 kPa. In experiments with both FC-72 and FC-87 further increases in pressure did not produce any significant increase in CHF. At a pressure of 101.3 kPa a subcooling of 30°C increased CHF on horizontal upward-facing chips by approximately 50 percent, as compared to 70 percent on vertically oriented packages. The enhancement in CHF due to subcooling decreased rapidly with increasing pressure, and the data showed that the influence of pressure and subcooling on CHF is not additive. A correlation to predict pool boiling CHF under the combined effects of pressure and subcooling is proposed.
Current mechanistic understanding of thiamin diphosphate-dependent enzymatic reactions.

Covering: 1990–2002The mechanism of thiamin diphosphate-dependent enzymatic reactions is discussed, concentrating on two enzymes involved in decarboxylating pyruvic acid, the yeast pyruvate decarboxylase and the pyruvate dehydrogenase multienzyme complex from Escherichia coli. The availability of high-resolution X-ray structures for several thiamin diphosphate-dependent enzymes, the use of site-specifically substituted protein variants (resulting from site-directed mutagenesis), the development of model reactions for the various putative intermediates, and the application of new mechanistic tools in solution have all contributed to a much better understanding of the role of the protein component in catalysis. Perhaps the most important advance in our understanding of these mechanisms concerns the role of the 4′-aminopyrimidine component of the coenzyme, widely ignored prior to the publication of the X-ray results. The current view is that the two aromatic rings both contribute to catalysis, perhaps carrying out an intramolecular proton transfer to initiate the various reactions, an ability that makes this coenzyme virtually unique among coenzymes.
Effects of Marketing Decisions on Net Present Value of Pork Production for Independent and Allied Swine Producers

Competitive environments in swine production make management strategies that increase profitability important. An open-coded model to evaluate the economic impact of two marketing strategies is developed for swine finishing operations. Higher profits are realized for a fixed-date marketing strategy in allied production than for a fixed-target-weight marketing strategy in independent production. Producing pigs to weights heavier than the average market weight also increases profits. Shipping pigs over a shortened time from a barn and decreasing time between batches of pigs improves profits if it can be done with a tighter weight distribution of pigs produced.
Using Bayesian Multilevel Whole Genome Regression Models for Partial Pooling of Training Sets in Genomic Prediction

Training set size is an important determinant of genomic prediction accuracy. Plant breeding programs are characterized by a high degree of structuring, particularly into populations. This hampers the establishment of large training sets for each population. Pooling populations increases training set size but ignores unique genetic characteristics of each. A possible solution is partial pooling with multilevel models, which allows estimating population-specific marker effects while still leveraging information across populations. We developed a Bayesian multilevel whole-genome regression model and compared its performance with that of the popular BayesA model applied to each population separately (no pooling) and to the joined data set (complete pooling). As an example, we analyzed a wide array of traits from the nested association mapping maize population. There we show that for small population sizes (e.g., <50), partial pooling increased prediction accuracy over no or complete pooling for populations represented in the training set. No pooling was superior; however, when populations were large. In another example data set of interconnected biparental maize populations either partial or complete pooling was superior, depending on the trait. A simulation showed that no pooling is superior when differences in genetic effects among populations are large and partial pooling when they are intermediate. With small differences, partial and complete pooling achieved equally high accuracy. For prediction of new populations, partial and complete pooling had very similar accuracy in all cases. We conclude that partial pooling with multilevel models can maximize the potential of pooling by making optimal use of information in pooled training sets.
Designed to ‘effectively frustrate’: copyright, technology and the agency of users

This research was assisted by a grant from the Digital Cultural Institutions Project of the Social Science Research Council, with funds provided by the Rockefeller Foundation.
Exponential Tilting with Weak Instruments: Estimation and Testing

This article analyses exponential tilting estimator with weak instruments in a nonlinear framework. Our paper differs from the previous literature in the context of consistency proof. Tests that are robust to the identification problem are also analysed. These are Anderson–Rubin and Kleibergen types of test statistics. We also conduct a simulation study wherein we compare empirical likelihood and continuous updating-based tests with exponential tilting (ET)-based ones. The designs involve GARCH(1,1) and contaminated structural errors. We find that ET-based Kleibergen test has the best size among these competitors.
Low‐Temperature Sintering of Aluminum Oxide

A fine-sized (∼0.1 μm), agglomerate-free Al2O3 dispersion was used to prepare homogeneous green bodies with ∼69% relative density and ∼10-nm median pore radius. Samples could be sintered at 1150°C to a relative density >99.5% and an average grain size of 0.25 μm.
Simple spin networks as Feynman graphs

We show how spin networks can be described and evaluated as Feynman integrals over an internal space. This description can, in particular, be applied to the so-called simple SO(D) spin networks that are of importance for higher-dimensional generalizations of loop quantum gravity. As an illustration of the power of the new formalism, we use it to obtain the asymptotics of an amplitude for the D simplex and show that its oscillatory part is given by the Regge action.
Vanishing theorems on toric varieties

We use Cox's description for sheaves on toric varieties and results about local cohomology with respect to monomial ideals to give a characteristic-free approach to vanishing results on toric varieties. As an application, we give a proof of a strong version of Fujita's Conjecture in the case of toric varieties. We also prove that every sheaf on a toric variety corresponds to a module over the homogeneous coordinate ring, generalizing Cox's result for the simplicial case.
Placement Optimization of Distributed-Sensing Fiber-Optic Sensors Using Genetic Algorithms

In this paper, we present methodology for the placement optimization of both discretely and continuously distributed fiber-optic sensors in which many point or quasi-point sensors can be multiplexed along a single optical fiber. A unified sensor performance metric is defined for vibration monitoring and fault detection as the integration/ summation of a weighted functional of some strain measure over the optical fiber length for both discretely and continuously distributed fiber-optic sensors. The optical fiber is represented by a nonuniform rational B-splines curve. The design variables include the control point coordinates of the nonuniform rational B-splines curve and the arclength coordinates of the point sensing element positions along the fiber. The constraints common to all kinds of optical sensors include the maximum fiber length and maximum allowed initial curvature. The constraints are treated as the exact penalty functions in the fitness function for any genetic algorithm. For discretely distributed fiber-optic sensors, we briefly show by an example how to use a genetic algorithm-based traveling salesman problem solver to optimally connect those optimally distributed sensors using one single optical fiber by minimizing the total fiber length. For continuously distributed fiber-optic sensors, two sets of examples are given as applications to fluttering or vibrating panels in aerospace engineering and a clinical smart bed for patient vital signal monitoring in biomedical engineering. In both cases, the integrating bend-sensing fiber-optic sensors are used.
Denominator Identity for Twisted Affine Lie Superalgebras

The study of denominator identities for Lie superalgebras was recently developed by M. Gorelik, V.G. Kac, P.Moseneder Frajria, I. Musson, P. Papi, M. Wakimoto and the author. In this paper we generalize these identities to the twisted affine case, completing the result to all affine Lie superalgebras.
An Arnoldi approach for generation of reduced-order models for turbomachinery

Abstract A linear reduced-order aerodynamic model is developed for aeroelastic analysis of turbomachines. The basis vectors are constructed using a block Arnoldi method. Although the model is cast in the time domain in state-space form, the spatial periodicity of the problem is exploited in the frequency domain to obtain these vectors efficiently. The frequency domain proper orthogonal decomposition is identified as a special case of the Arnoldi method. We show an application where the aerodynamic model is coupled with a simple structural model that has two degrees of freedom for each blade. The technique is applicable to viscous and three-dimensional problems as well as multi-stage problems with inlet and exit disturbance flows, although here results are presented for two-dimensional, inviscid flow through a 20-blade single-stage rotor. In this case, the number of states of the model is on the order of 10 per blade passage, making it appropriate for control applications.
Chirp and click evoked auditory steady state responses

In this study, Auditory Steady State Responses (ASSR) to 100 /spl mu/sec clicks and 4 msec cochlear chirps are recorded in adult subjects at repetition rates of 20 to 100 Hz in 10 Hz increments. Response characteristics of ASSRs are compared in the frequency domain. Results show that response amplitudes to both stimuli peak in the proximity of 40 Hz and 80 Hz, but chirps generate responses with larger amplitudes at all repetition rates. The responses at 40 Hz repetition rates for both clicks and chirps are larger than the corresponding responses at 80 Hz stimuli in awake adults. The 40 Hz responses, however, show greater variability than the 80 Hz responses depending on the subject's state of consciousness. The predictions of the ASSR waveforms at each repetition rate were then synthesized by superimposing the suitably shifted Middle Latency Response (MLR) waveforms that were recorded during the same session with a stimulus repetition rate of 10 Hz for both click and chirp recordings. This part of the study was undertaken to Investigate the validity of the hypothesis which states that the steady state responses are simply the linear additions of transient MLRs. The results showed that the synthesized waveforms resembled the real recordings to some extent, but consistently had larger amplitudes. This difference is assumed to be a result of the adaptation effects of higher stimulus rates.
Global attractor for a nonlocal model for biological aggregation

We investigate the long term behavior in terms of global attractors, as time goes to infinity, of solutions to a continuum model for biological aggregations in which individuals experience long-range social attraction and short range dispersal. We consider the aggregation equation with both degenerate and non-degenerate diffusion in a bounded domain subject to various boundary conditions. In the degenerate case, we prove the existence of the global attractor and derive some optimal regularity results. Furthermore, in the non-degenerate case we give a complete structural characterization of the global attractor, and also discuss the convergence of any bounded solutions to steady states. In particular, under suitable assumptions on the parameters of the problem, we establish the convergence of the bounded solution u(t) to a single steady state u(*), and the rate of convergence parallel to u(t)-u(*)parallel to(Lp(Omega)) similar to (1+t)(-rho), as t -> infinity for any p> 1, and some rho=rho(u(*),rho)is an element of(0,1). Finally, the existence of an exponential attractor is also demonstrated for sufficiently smooth kernels in the case of non-degenerate diffusion. Our analysis extends and complements the analysis from [17] and many other fundamental works.
Adaptive learning, endogenous uncertainty, and asymmetric dynamics

Abstract I present a simple model where forecasting confidence affects aggregate demand. It is shown that this model has similar stability properties, under statistical and evolutionary learning, as a model without a confidence affect. From this setup, I introduce “Expectational Business Cycles” where output fluctuates due to learning, heterogeneous forecasting models and random changes in the efficient forecasting model. Agents use one of two forecasting models to forecast future variables while heterogeneity is dictated via an evolutionary process. Increased uncertainty, due to a shock to the structure of the economy, may result in a sudden decrease in output. As agents learn the equilibrium, output slowly increases to its equilibrium value. Expectational business cycles tend to arrive faster, last longer and are more severe as agents possess less information.
NGOs, International Donors, and the Postmaterial Disjuncture in Latin America

NGOs have proliferated in the developing world, assuming key political roles as intermediary organizations representing public interests. Yet at least in the three Latin American countries examined here, the proportion of the NGO sector focused on postmaterial issues massively outpaces the proportion of the mass public that considers these issues highly salient. This article demonstrates this “postmaterial disjuncture” and theorizes that international donors help drive it by favoring NGOs that pursue postmaterial issues. This hypothesis is evaluated by analyzing a unique dataset containing information on over 700 NGOs. Organizations pursuing postmaterial issues are more than three times likely to receive international funding than are otherwise identical NGOs pursuing material issues. While international donors may be well intentioned, their postmaterial agendas shape the issue orientation of the NGO sector, resulting in potentially adverse consequences for its ability to effectively represent mass interests.
Reliability Modeling of Lead-Free Solder Joints in Wafer-Level Chip Scale Packages

Board-level thermomechanical fatigue lifetimes of five different wafer-level chip scale packages (WCSPs) with lead-free solder joints were studied by both experiment and finite element method modeling. The effect of three different constitutive laws of the lead-free solder, namely Anand viscoplasticity, power law break-down creep, and time-hardening creep are also investigated for each of the five packages. The fatigue correlation parameters based on the increment of volume-averaged inelastic strain energy density are deduced for each of the corresponding three constitutive laws. It is demonstrated that the relative error of the predicted lifetime for WCSP with lead-free solder joints can be within 10% compared with experiment. It is found that the fatigue correlation parameters depend strongly on the specific constitutive law. Another important finding is that the fatigue correlation parameters depend on the specific package family. It is also demonstrated that when fatigue correlation parameters calibrated for other package families are applied to WCSPs, the error in predicted lifetimes is consistently large.
Adaptive control of systems with nonsmooth input and output nonlinearities

Adaptive control schemes are developed for plants with unknown nonsmooth nonlinearities at both the input and output of a linear dynamics. New controller parameterizations with nonlinearity inverses for parameterized nonlinearities are employed. When implemented with true parameters and properly initialized, the inverse controller ensures closed-loop signal boundedness and output tracking. Adaptive laws are designed to update the parameter estimates to implement adaptive inverse controllers for unknown nonlinearities in two cases: the linear part known and the linear part unknown.
Rethinking the Sociological Measurement of Poverty

Despite serious methodological problems, quantitative studies of poverty by U.S. sociologists predominantly rely on the official U.S. measure. After reviewing the shortcomings of the U.S. measure, this article examines several theoretical and methodological advances in poverty measurement. After synthesizing literature on poverty measurement, I argue that ideal measures of poverty should: (1) measure comparative historical variation effectively; (2) be relative rather than absolute; (3) conceptualize poverty as social exclusion; (4) assess the impact of taxes, transfers, and state benefits; and (5) integrate the depth of poverty and the inequality among the poor. Next, this article evaluates sociological studies published since 1990 for their consideration of these criteria. Due to sociology’s neglect of these criteria, this article advocates for three alternative poverty indices: the interval measure, the ordinal measure, and the sum of ordinals measure. Finally, using the Luxembourg Income Study, I examine the empirical patterns with these three measures, across advanced capitalist democracies from 1967 to 1997. Estimates of these poverty indices are made available for future research.
Integration Of Visual Inter-word Constraints And Linguistic Knowledge In Degraded Text Recognition

Degraded text recognition is a difficult task. Given a noisy text image, a word recognizer can be applied to generate several candidates for each word image. High-level knowledge sources can then be used to select a decision from the candidate set for each word image. In this paper, we propose that visual inter-word constraints can be used to facilitate candidate selection. Visual inter-word constraints provide a way to link word images inside the text page, and to interpret them systematically.
Learning Manifolds with K-Means and K-Flats

We study the problem of estimating a manifold from random samples. In particular, we consider piecewise constant and piecewise linear estimators induced by k-means and k-flats, and analyze their performance. We extend previous results for k-means in two separate directions. First, we provide new results for k-means reconstruction on manifolds and, secondly, we prove reconstruction bounds for higher-order approximation (k-flats), for which no known results were previously available. While the results for k-means are novel, some of the technical tools are well-established in the literature. In the case of k-flats, both the results and the mathematical tools are new.
Understanding the Solar Home price premium: Electricity generation and ''Green'' social status $

This study uses a large sample of homes in the San Diego area and Sacramento, California area to provide some of the first capitalization estimates of the sales value of homes with solar panels relative to comparable homes without solar panels. Although the residential solar home market continues to grow, there is little direct evidence on the market capitalization effect. Using both hedonics and a repeat sales index approach we find that solar panels are capitalized at roughly a 3.5% premium. This premium is larger in communities with a greater share of college graduates and of registered Prius hybrid vehicles.
Incremental tradeoff resolution in qualitative probabilistic networks

Qualitative probabilistic reasoning in a Bayesian network often reveals tradeoffs: relationships that are ambiguous due to competing qualitative influences. We present two techniques that combine qualitative and numeric probabilistic reasoning to resolve such tradeoffs, inferring the qualitative relationship between nodes in a Bayesian network. The first approach incrementally marginalizes nodes that contribute to the ambiguous qualitative relationships. The second approach evaluates approximate Bayesian networks for bounds of probability distributions, and uses these bounds to determinate qualitative relationships in question. This approach is also incremental in that the algorithm refines the state spaces of random variables for tighter bounds until the qualitative relationships are resolved. Both approaches provide systematic methods for tradeoff resolution at potentially lower computational cost than application of purely numeric methods.
Level set methods for finding critical points of mountain pass type

Abstract Computing mountain passes is a standard way of finding critical points. We describe a numerical method for finding critical points that is convergent in the nonsmooth case and locally superlinearly convergent in the smooth finite dimensional case. We apply these techniques to describe a strategy for addressing the Wilkinson problem of calculating the distance from a matrix to a closest matrix with repeated eigenvalues. Finally, we relate critical points of mountain pass type to nonsmooth and metric critical point theory.
Quantitative property A, Poincaré inequalities, L p -compression and L p -distortion for metric measure spaces

We introduce a quantitative version of Property A in order to estimate the Lp-compressions of a metric measure space X. We obtain various estimates for spaces with sub-exponential volume growth. This quantitative property A also appears to be useful to yield upper bounds on the Lp-distortion of finite metric spaces. Namely, we obtain new optimal results for finite subsets of homogeneous Riemannian manifolds. We also introduce a general form of Poincare inequalities that provide constraints on compressions, and lower bounds on distortion. These inequalities are used to prove the optimality of some of our results.
KAT(ching) Metabolism by the Tail: Insight into the Links between Lysine Acetyltransferases and Metabolism

Post-translational modifications of histones elicit structural and functional changes within chromatin that regulate various epigenetic processes. Epigenetic mechanisms rely on enzymes whose activities are driven by coenzymes and metabolites from intermediary metabolism. Lysine acetyltransferases (KATs) catalyze the transfer of acetyl groups from acetyl-CoA to epsilon amino groups. Utilization of this critical metabolite suggests these enzymes are modulated by the metabolic status of the cell. This review highlights studies linking KATs to metabolism. We cover newly identified acyl modifications (propionylation and butyrylation), discuss the control of KAT activity by cellular acetyl-CoA levels, and provide insights into how acetylation regulates metabolic proteins. We conclude with a discussion of the current approaches to identifying novel KATs and their metabolic substrates.
Direct Calculation of the Radiative Efficiency of an Accretion Disk Around a Black Hole

Numerical simulation of magnetohydrodynamic (MHD) turbulence makes it possible to study accretion dynamics in detail. However, special effort is required to connect inflow dynamics (dependent largely on angular momentum transport) to radiation (dependent largely on thermodynamics and photon diffusion). To this end, we extend the flux-conservative, general relativistic MHD (GRMHD) code HARM from axisymmetry to full three dimensions. The use of an energy conserving algorithm allows the energy dissipated in the course of relativistic accretion to be captured as heat. The inclusion of a simple optically thin cooling function permits explicit control of the simulated disk's geometric thickness as well as a direct calculation of both the amplitude and location of the radiative cooling associated with the accretion stresses. Fully relativistic ray-tracing is used to compute the luminosity received by distant observers. For a disk with aspect ratio H/r 0.1 accreting onto a black hole with spin parameter a/M = 0.9, we find that there is significant dissipation beyond that predicted by the classical Novikov-Thorne model. However, much of it occurs deep in the potential, where photon capture and gravitational redshifting can strongly limit the net photon energy escaping to infinity. In addition, with these parameters and this radiation model, significant thermal and magnetic energy remains with the gas and is accreted by the black hole. In our model, the net luminosity reaching infinity is 6% greater than the Novikov-Thorne prediction. If the accreted thermal energy were wholly radiated, the total luminosity of the accretion flow would be 20% greater than the Novikov-Thorne value.
Enantioselective synthesis of boron-substituted quaternary carbon stereogenic centers through NHC-catalyzed conjugate additions of (pinacolato)boron units to enones.

The first examples of Lewis base catalyzed enantioselective boryl conjugate additions (BCAs) that generate products containing boron-substituted quaternary carbon stereogenic centers are disclosed. Reactions are performed in the presence of 1.0–5.0 mol % of a readily accessible chiral accessible N-heterocyclic carbene (NHC) and commercially available bis(pinacolato)diboron; cyclic or linear α,β-unsaturated ketones can be used and rigorous exclusion of air or moisture is not necessary. The desired products are obtained in 63–95 % yield and 91:9 to >99:1 enantiomeric ratio (e.r.). The special utility of the NHC-catalyzed approach is demonstrated in the context of an enantioselective synthesis of natural product antifungal (−)-crassinervic acid.
Planning by rewriting

Domain-independent planning is a hard combinatorial problem. Taking into account plan quality makes the task even more dificult. This article introduces Planning by Rewriting (PbR), a new paradigm for efficient high-quality domain-independent planning. PbR exploits declarative plan-rewriting rules and efficient local search techniques to transform an easy-to-generate, but possibly suboptimal, initial plan into a high-quality plan. In addition to addressing the issues of planning efficiency and plan quality, this framework offers a new anytime planning algorithm. We have implemented this planner and applied it to several existing domains. The experimental results show that the PbR approach provides significant savings in planning effort while generating high-quality plans.
NEW CHIRAL SYNTHONS FROM THE MICROBIAL OXIDATION OF BROMONAPHTHALENES

Abstract 1-Bromo- and 2-bromonaphthalene were subjected to bio-oxidation with whole cells of Pseudomonas putida NCIB 9816-11. The major metabolites were isolated and spectroscopically characterized as (+)- cis -( 1R,2S )-Dihydroxy-1,2-dihydro-8-bromonaphthalene 1 , (+)- cis -( 1R,2S -Dihydroxy-1,2-dihydro-5-bromonaphthalene 2 from 1-bromo-naphthalene and (+)- cis -( 1R,2S )-Dihydroxy-1,2-dihydro-7-bromonaphthalene 8 from 2-bromonaphthalene. The absolute stereochemistry and enantiomeric excess were determined by conversion of each metabolite to the known (−)- cis -tetrahydronaphthalene diol 6 .
Numerical Study of an Evaporating Meniscus on a Moving Heated Surface

The present study is performed to numerically analyze an evaporating meniscus bounded between the advancing and receding interfaces on a moving heated surface. The numerical scheme developed for analyzing interface motion during bubble growth in pool boiling has been applied. A column of liquid is placed between a nozzle outlet and a moving wall, and calculations are done in two dimensions with a fixed distance between the nozzle and the wall. The results show that the wall velocity creates a circulation near the meniscus base, resulting in transient heat conduction. The local wall heat transfer is found to vary significantly along the meniscus base, the highest being near the advancing contact line. The heat transfer coefficient is found to depend on the advancing contact angle and wall velocity but is independent of the wall superheat. Reasonable agreement is observed when the meniscus profile and heat transfer results obtained from the numerical simulation are compared to the experimental data.
Surprisingly high diastereoselection in the aldol reactions of sodium enolates of α-amino methyl ketones

Abstract Kinetic enolates of a number of α-(N,N-dibenzyl)amino methyl ketones were allowed to react with a variety of aldehydes. High diastereoselectivity was observed for sodium enolates compared to their lithium counterparts.
Low-loss high-speed speckle reduction using a colloidal dispersion

We present a simple and robust approach to reduce laser speckle, which has limited the adoption of lasers in imaging and display applications. We use colloidal solutions that can quickly reduce speckle contrast due to the Brownian motion of the scattering particles. The high insertion loss associated with propagation through a colloidal solution was overcome by using white paint to cover the sides of the cuvette and an optical fiber to deliver the laser light deep into the colloidal solution, enabling transmission greater than 90%. The diffused laser output followed a Lambertian distribution and produced speckle contrast below 4% at an integration time of 129 μs. The ability for colloidal solutions to achieve fast speckle reduction without power consumption while maintaining high transmission, low cost, a compact size, and a long lifetime makes our approach useful for a wide range of laser imaging and projection applications.
FLAME: a program to flexibly align molecules.

Herein, we describe a method to flexibly align molecules (FLAME = FLexibly Align MolEcules). FLAME aligns two molecules by first finding maximum common pharmacophores between them using a genetic algorithm. The resulting alignments are then subjected to simultaneous optimizations of their internal energies and an alignment score. The utility of the method in pairwise alignment, multiple molecule flexible alignment, and database searching was examined. For pairwise alignment, two carboxypeptidase ligands (Protein Data Bank codes 1cbx and 3cpa), two estrogen receptor ligands (1err and 3ert), and two thrombin ligands (1dwe and 1dwd) were used as test sets. Alignments generated by FLAME starting from CONCORD structures compared very well to the X-ray structures (average root-mean-square deviation = 0.36 A) even without further minimization in the presence of the protein. For multiple flexible alignments, five structurally diverse D3 receptor ligands were used as a test set. The FLAME alignment automatically i...
Sigma-point Kalman filtering for integrated GPS and inertial navigation

A sigma-point Kalman filter is derived for integrating GPS measurements with inertial measurements from gyros and accelerometers to determine both the position and the attitude of a moving vehicle. Sigma-point filters use a carefully selected set of sample points to more accurately map the probability distribution than the linearization of the standard extended Kalman filter (KKF), leading to faster convergence from inaccurate initial conditions in position/attitude estimation problems. The filter formulation is based on standard inertial navigation equations. The global attitude parameterization is given by a quaternion, while a generalized three-dimensional attitude representation is used to define the local attitude error. A multiplicative quaternion-error approach is used to guarantee that quaternion normalization is maintained in the filter. Simulation and experimental results are shown to compare the performance of the sigma-point filter with a standard EKF approach.
Positron annihilation — a localized probe of lattice defects in metals☆

It is evident that positron annihilation spectroscopy has become a valuable technique for the study of metals. Owing to the ability of the positron to localize in a variety of metal defects where its subsequent annihilation yields information regarding its local electronic environment, we now have a new and unique tool available with which to probe the nature of lattice defects in metals, which supplements previously available methods. Many new PAS experimental and theoretical techniques and additional applications to problems concerning defects and microstructures in metals are evolving in this rapidly developing area. It seems clear that in the future, the usefulness of PAS for the study of defects in metals will continue to increase.
A 900-MHz/1.8-GHz CMOS transmitter for dual-band applications

The design of a radio-frequency transmitter that can operate in two bands while employing a minimal number of external components entails many challenges at both the architecture and the circuit levels. This paper describes the design of a 900-MHz/1.8-GHz transmitter implemented in CMOS technology for dual-band applications. Configured as a two-step architecture, the circuit generates the first upconverted signal in quadrature form and subsequently performs single-sideband modulation to produce the output in two bands. Fabricated in a 0.6-/spl mu/m digital CMOS technology, the transmitter exhibits unwanted spurs 40 dB below the carrier while drawing 75 mW from a 3-V supply.
Minimizing hidden-node network interference by optimizing SISO and MIMO spectral efficiency

In this paper, the optimal spectral efficiency (data rate divided by the message bandwidth) that minimizes the probability of causing disruptive interference for ad hoc wireless networks or cognitive radios is investigated. Two basic problem constraints are considered: a given message size, or fixed data rate. Implicitly, the trade being optimized is between longer transmit duration and wider bandwidth versus higher transmit power. Both single-input single-output (SISO) and multiple-input multiple-output (MIMO) links are considered. Here, a link optimizes its spectral efficiency to be a “good neighbor.” The probability of interference is characterized by the probability that the signal power received by a hidden node in a wireless network exceeds some threshold. The optimized spectral efficiency is a function of the transmitter-to-hidden-node channel exponent, exclusively. It is shown that for typical channel exponents a spectral efficiency of slightly greater than 1 b/s/Hz per antenna is optimal. It is also shown that the optimal spectral efficiency is valid in the environment with multiple hidden nodes. Also explicit evaluations of the probability of collisions is presented as a function of spectral efficiency.