cssi/SciSciGPT-SciSciNet huggingface dataset:
Asymptotic and finite sample distribution theory for IV estimators and tests in partially identified structural equations

Abstract General formulae for the finite sample and asymptotic distributions of the instrumental variable estimators and the Wald statistics in a simultaneous equation model are derived. It is assumed that the coefficient vectors of both endogenous and exogenous variables are only partially identified, even though the order condition for identification is satisfied. This work extends previous results in Phillips (1989) where the coefficient vector of the exogenous variables is partially identified and that of the endogenous variables is totally unidentified. The effect of partial identification on the finite sample and asymptotic distributions of the estimators and the Wald statistics is analyzed by isolating identifiable parts of the coefficient vectors using a rotation of the coordinate system developed in Phillips (1989). The pdf's of the estimators and the Wald statistics are illustrated using simulation and compared with their respective asymptotic distributions.
Tracer Diffusion and Electrical Conductivity in Sodium‐Rubidium Silicon Sulfide Glasses

The tracer diffusion coefficients of 22Na and 86Rb and electrical conductivity were measured in a series of 0.56(Na, Rb)2S.0.44SiS2 glasses as a function of the Rb/Na ratio and temperature. The data were used to calculate the Haven ratio as a function of the Rb/Na ratio. The Haven ratio at 149.6°C increases from ∼0.3 in single-alkali glasses to ∼0.80 for intermediate compositions. The results are consistent with a single jump mechanism involving jumps of alkali ions between unoccupied sites. The observed correlation effects arise through interactions between alkali ions and charge-compensating centers in the glass network. The charge-compensating centers are thought to correspond to non-bridging oxygen ions in some oxide glasses and to nonbridging sulfur ions in sodium-rubidium silicon sulfide glasses.
Lunar magma transport phenomena

An outline of magma transport theory relevant to the evolution of a possible Lunar Magma Ocean and the origin and transport history of the later phase of mare basaltic volcanism is presented. A simple model is proposed to evaluate the extent of fractionation as magma traverses the cold lunar lithosphere. If Apollo green glasses are primitive and have not undergone significant fractionation en route to the surface, then mean ascent rates of 10 m/s and cracks of widths greater than 40 m are indicated. Lunar tephra and vesiculated basalts suggest that a volatile component plays a role in eruption dynamics. The predominant vapor species appear to be CO CO2, and COS. Near the lunar surface, the vapor fraction expands enormously and vapor internal energy is converted to mixture kinetic energy with the concomitant high-speed ejection of vapor and pyroclasts to form lunary fire fountain deposits such as the Apollo 17 orange and black glasses and Apollo 15 green glass.
Equivariant-constructible Koszul duality for dual toric varieties

Abstract For affine toric varieties X and X ˇ defined by dual cones, we define an equivalence of categories between mixed versions of the equivariant derived category D T b ( X ) and the derived category of sheaves on X ˇ which are locally constant with unipotent monodromy on each orbit. This equivalence satisfies the Koszul duality formalism of Beilinson, Ginzburg, and Soergel.
Methanol on Enceladus

Near infrared spectra of the surface of Enceladus returned by Cassini show the presence of an absorption feature at 3.53 μm, ascribed by Brown et al. (2006) to “short chain organics,” and by Newman et al. (2007) to hydrogen peroxide. We assign this feature tentatively to methanol. Variations in the peak position of the feature suggest that methanol in the “tiger stripes” region may be segregated from the water ice, and not homogeneously distributed in the ice matrix. The photolytic destruction of methanol implies that methane or methanol itself must be continually deposited on the surface. On Enceladus, methanol may be generated photochemically from a mixed methane/water ice, or deposited from the plume itself. The variation in the concentration of methanol over the surface could be used to distinguish between these two processes.
The old boy (and girl) network: Social network formation on university campuses

This paper documents the structure and composition of social networks on university campuses and investigates the processes that lead to their formation. Using administrative data and information from Facebook.com, we document the factors that are the strongest predictors of whether two students are friends. Race is strongly related to social ties, even after controlling for a variety of measures of socioeconomic background, ability, and college activities. We develop a model of the formation of social networks that decomposes the formation of social links into effects based upon the exogenous school environment and effects of endogenous choice arising from preferences for certain characteristics in one's friends. We use student-level data from an actual social network to calibrate the model. We simulate the social network under alternative university policies aimed at reducing social segmentation. We find that changes in the school environment that affect the likelihood that two students interact have only a limited potential to reduce the racial segmentation of the social network.
Estimation of aquifer transport parameters from resistivity monitoring data within a coupled inversion framework

Summary Despite the fact that electrical resistivity surveys are increasingly used to monitor solute migration in porous media, there is limited experience in how these data can be used to characterize aquifer transport parameters. In this study we evaluate whether electrical resistivity monitoring data can constrain the hydraulic conductivity, porosity, and dispersivity of a homogenous aquifer within the framework of coupled inversion. We focus on voltage responses from a single set of current electrodes to provide insights into the information content of these measurements and motivate future work in designing optimal surveys for monitoring groundwater transport processes. We have found that even in this simple system two distinct types of tradeoffs exist that could confound the direct estimation of transport parameters. First, different values of porosity and hydraulic conductivity can produce the same plume velocity, thereby leading to identical concentration distributions in the subsurface. In ideal cases this hydrologic non-uniqueness can be resolved by electrical data because electrical resistivity is dependent on both solute concentration and porosity, but this discrimination will only be possible when the rock physics relationship between concentration and resistivity can be accurately determined. The second type of non-uniqueness occurs when different concentration plumes produce equivalent electrical responses. In this case, tradeoffs between plume velocity and dispersivity cause shifts in the position and mass of solute relative to the electrodes that result in equivalent values of subsurface apparent resistivity. This non-uniqueness contributes to poor discriminating power when using an objective function based on the magnitude of voltage changes. However, the problem can be overcome by explicitly recognizing that different information about transport processes is captured by the timing versus magnitude of the electrical response in monitoring data. Though we have investigated a homogenous system, we argue that the insights here can also be applied to the estimation of effective transport parameters for heterogeneous systems.
Relations that preserve compact filters

Many classes of maps are characterized as (possibly multi-valued) maps preserving particular types of compact filters.
Spatial Mismatch and the Structure of American Metropolitan Areas, 1970–2000

. This paper analyzes the impact of employment and population shifts in U.S. metropolitan areas from 1970 to 2000 on a spatial mismatch index to determine how metropolitan residents reacted to changes in metropolitan employment distributions. In particular, it seeks to determine whether suburban employment growth created new areas to which access is valued or whether it repelled metropolitan residents and sparked population growth in more distant suburban locations. The results show that residents tended to move away from areas gaining jobs. Black residents, on the other hand, appeared to be attracted to areas that are experiencing employment growth.
Abeliants and their application to an elementary construction of Jacobians

Abstract The abeliant is a polynomial rule which to each n×n by n+2 array with entries in a commutative ring with unit associates an n×n matrix with entries in the same ring. The theory of abeliants, first introduced in an earlier paper of the author, is simplified and extended here. Now let J be the Jacobian of a nonsingular projective algebraic curve defined over an algebraically closed field. With the aid of the theory of abeliants we obtain explicit defining equations for J and its group law.
Carl Nielsen unmasked: Art and popular musical styles in Maskarade

Abstract Although Carl Nielsen's international reputation rests on his symphonies, in his homeland he is equally beloved for his songs. Over the course of his life, the former increased in complexity as the latter grew more folk‐like, so that Nielsen developed into a Janus‐faced composer, a master of both art and popular styles. These genres typically have been studied in isolation so that, though many scholars note that Nielsen's music is full of contrast, few show that this depends on the opposition of two specific styles. Nor has a parallel been drawn between this musical tension and the conflicts Nielsen faced in his personal life, not the least of which was the insidious Law of Jante ("Thou shalt not believe thou art something") that has plagued many an artist from a “peripheral” nation. Nowhere is Nielsen's opposition of art and popular styles more effective than in Maskarade (1904–1906), arguably the Danes’ favorite among his compositions, in which the two styles represent conflicting dramatic them...
A Solvable toy model for tachyon condensation in string field theory

The lump solution of 3 field theory provides a toy model for unstable D-branes of bosonic string theory. The field theory living on this lump is itself a cubic field theory involving a tachyon, two additional scalar fields, and a scalar field continuum. Its action can be written explicitly because the fluctuation spectrum of the lump turns out to be governed by a solvable Schroedinger equation; the = 3 case of a series of reflectionless potentials. We study the multiscalar tachyon potential both exactly and in the level expansion, obtaining insight into issues of convergence, branches of the solution space, and the mechanism for removal of states after condensation. In particular we find an interpretation for the puzzling finite domain of definition of string field marginal parameters.
Towards adaptive Web sites: conceptual framework and case study

The creation of a complex Web site is a thorny problem in user interface design. In this paper we explore the notion of adaptive Web sites: sites that semi-automatically improve their organization and presentation by learning from visitor access patterns. It is easy to imagine and implement Web sites that offer shortcuts to popular pages. Are more sophisticated adaptive Web sites feasible? What degree of automation can we achieve? To address the questions above, we describe the design space of adaptive Web sites and consider a case study: the problem of synthesizing new index pages that facilitate navigation of a Web site. We present the PageGather algorithm, which automatically identifies candidate link sets to include in index pages based on user access logs. We demonstrate experimentally that PageGather outperforms the Apriori data mining algorithm on this task. In addition, we compare PageGather’s link sets to pre-existing, human-authored index pages. © 1999 Published by Elsevier Science B.V. All rights reserved.
Strongly Interacting Matter at High Energy Density

This lecture concerns the properties of strongly interacting matter (which is described by Quantum Chromodynamics) at very high energy density. I review the properties of matter at high temperature, discussing the deconfinement phase transition. At high baryon density and low temperature, large N{sub c} arguments are developed which suggest that high baryonic density matter is a third form of matter, Quarkyonic Matter, that is distinct from confined hadronic matter and deconfined matter. I finally discuss the Color Glass Condensate which controls the high energy limit of QCD, and forms the low x part of a hadron wavefunction. The Glasma is introduced as matter formed by the Color Glass Condensate which eventually thermalizes into a Quark Gluon Plasma.
Relativistic brane scattering

Abstract We calculate relativistic phase shifts resulting from the large impact parameter scattering of 0-branes off p-branes within supergravity. Their full functional dependence on velocity agrees with that obtained by identifying the p-branes with D-branes in string theory. These processes are also described by 0-brane quantum mechanics, but only in the non-relativistic limit. We show that an improved 0-brane quantum mechanics based on a Born-Infeld-type Lagrangian also does not yield the relativistic results. The scattering of 0-branes off bound states of arbitrary numbers of 0-branes and 2-branes is analyzed in detail, and we find agreement between supergravity and string theory at large distances to all orders in velocity. Our careful treatment of this system, which embodies the 11-dimensional kinematics of 2-branes in M(atrix) theory, makes it evident that control of 1 n corrections will be necessary in order to understand our relativistic results within M(atrix) theory.
Graph based anomaly detection and description: a survey

Detecting anomalies in data is a vital task, with numerous high-impact applications in areas such as security, finance, health care, and law enforcement. While numerous techniques have been developed in past years for spotting outliers and anomalies in unstructured collections of multi-dimensional points, with graph data becoming ubiquitous, techniques for structured graph data have been of focus recently. As objects in graphs have long-range correlations, a suite of novel technology has been developed for anomaly detection in graph data. This survey aims to provide a general, comprehensive, and structured overview of the state-of-the-art methods for anomaly detection in data represented as graphs. As a key contribution, we give a general framework for the algorithms categorized under various settings: unsupervised versus (semi-)supervised approaches, for static versus dynamic graphs, for attributed versus plain graphs. We highlight the effectiveness, scalability, generality, and robustness aspects of the methods. What is more, we stress the importance of anomaly attribution and highlight the major techniques that facilitate digging out the root cause, or the `why', of the detected anomalies for further analysis and sense-making. Finally, we present several real-world applications of graph-based anomaly detection in diverse domains, including financial, auction, computer traffic, and social networks. We conclude our survey with a discussion on open theoretical and practical challenges in the field.
On Protection by Layout Randomization

Layout randomization is a powerful, popular technique for software protection. We present it and study it in programming-language terms. More specifically, we consider layout randomization as part of an implementation for a high-level programming language; the implementation translates this language to a lower-level language in which memory addresses are numbers. We analyze this implementation, by relating low-level attacks against the implementation to contexts in the high-level programming language, and by establishing full abstraction results.
Onset in magnetoplasmadynamic thrusters with finite-rate ionization

Quasi-one-dimensional self-field flow in a magnetoplasmadynamic thruster is analyzed, including the effect of nonequilibrium ionization. This theory, like the frozen flow theory, predicts the occurrence of the destructive "onset" phenomenon due to an excessive back Electromotive Force (EMF). Comparison between this theory and experiments on a straight coaxial thruster is given and is shown to be good within the limits of quasi-one-dim ensionality. The back-EMF onset mechanism is also shown here to be influenced by wall friction and heat transfer, and a choking condition incorporating these effects is derived. a a* A B B* Bt CD DH F h h* hc J J* k kb kf
Studies of the Synthesis of Rubranitrose and Crystal Structure of Methyl 2,3,6-Trideoxy-3-C-Methyl-3-Nitro-α-D-Ribo-Hexopyranoside

Abstract The branched-chain nitro sugar methyl 2,3,6-trideoxy-3-C-methyl-3-nitro-α-D-ribo-hexopyranoside 4 was investigated as a precursor to D-rubranitrose, a nitro sugar found in the antibiotic rubradirin. X-ray cyrstallographic analysis of 4 shows that the pyranose ring adopts the 4 C 1 conformation with the methoxy group at C-1 and the nitro group at C-3 in a 1,3-diaxial relationship. There is an intermolecular hydrogen bond involving a nitro group oxygen of one monosaccharide residue and the C-4 hydroxyl group of the adjacent residue in the crystal lattice. This interaction results in a helical crystal packing. A series of nucleophilic displacement reactions was carried out on the triflate derivative of 4 in an attempt to introduce an axial carbon-oxygen bond at C-4 required for rubranitrose. Displacements with acetate and propionate gave as products the monosaccharide esters with the desired D-xylo configuration.
Wolf-Rayet Mass-Loss Limits Due to Frequency Redistribution

The hypothesis that CAK-type line driving is responsible for the large observed Wolf-Rayet (W-R) mass-loss rates has been called into question in recent theoretical studies. The purpose of this paper is to reconsider the plausibility of line driving of W-R winds within the standard approach using the Sobolev approximation while advancing the conceptual understanding of this topic. Due to the multiple scattering required in this context, of particular importance is the role of photon frequency redistribution into spectral gaps, which in the extreme limit yields the statistical Sobolev-Rosseland (SSR) mean approximation. Interesting limits to constrain are the extremes of no frequency redistribution, in which the small radii and corresponding high W-R surface temperature induces up to twice the mass-loss rate relative to cooler stars, and the SSR limit, in which the reduced efficiency of the driving drops the mass flux by as much as an order of magnitude whenever there exist significant gaps in the spectral line distribution. To see how this efficiency drop might be sufficiently avoided to permit high W-R mass loss, we explore the suggestion that ionization stratification may serve to fill the gaps globally over the wind. We find that global ionization changes can only fill the gaps sufficiently to cause about a 25% increase in the mass-loss rate over the local SSR limit. Higher temperatures and more ionization states (especially of iron) may be needed to achieve optically thick W-R winds, unless strong clumping corrections eliminate the need for such winds.
Rings of Dark Matter in Collisions Between Clusters of Galaxies

Several lines of evidence suggest that the galaxy cluster Cl0024+17, an apparently relaxed system, is actually a collision of two clusters, the interaction occurring along our line of sight. Recent lensing observations suggest the presence of a ringlike dark matter structure, which has been interpreted as the result of such a collision. In this paper, we present N-body simulations of cluster collisions along the line of sight to investigate the detectability of such features. We use realistic dark matter density profiles as determined from cosmological simulations. Our simulations show a 'shoulder' in the dark matter distribution after the collision, but no ring feature even when the initial particle velocity distribution is highly tangentially anisotropic ({sigma}{sub {theta}}/{sigma} {sub r} >> 1). Only when the initial particle velocity distribution is circular do our simulations show such a feature. Even modestly anisotropic velocity distributions are inconsistent with the halo velocity distributions seen in cosmological simulations and would require highly fine-tuned initial conditions. Our investigation leaves us without an explanation for the dark matter ringlike feature in Cl0024+17 suggested by lensing observations.
GPS‐Based System for Satellite Tracking and Geodesy

High-performance receivers and data processing systems developed for GPS are reviewed. The GPS Inferred Positioning System (GIPSY) and the Orbiter Analysis and Simulation Software (OASIS) are described. The OASIS software is used to assess GPS system performance using GIPSY for data processing. Consideration is given to parameter estimation for multiday arcs, orbit repeatability, orbit prediction, daily baseline repeatability, agreement with VLBI, and ambiguity resolution. Also, the dual-frequency Rogue receiver, which can track up to eight GPS satellites simultaneously, is discussed.
Nuclear Power Reactors: A Study in Technological Lock-in

Recent theory has predicted that if competing technologies operate under dynamic increasing returns, one, possibly inferior, technology will dominate the market. The history of nuclear power technology is used to illustrate these results. Light water is considered inferior to other technologies, yet it dominates the market for power reactors. This is largely due to the early adoption and heavy development by the U.S. Navy of light water for submarine propulsion. When a market for civilian power emerged, light water had a large head start, and by the time other technologies were ready to enter the market, light water was entrenched.
Stable stem enabled Shannon entropies distinguish non-coding RNAs from random backgrounds

The computational identification of RNAs in genomic sequences requires the identification of signals of RNA sequences. Shannon base pairing entropy is an indicator for RNA secondary structure fold certainty in detection of structural, non-coding RNAs (ncRNAs). Under the Boltzmann ensemble of secondary structures, the probability of a base pair is estimated from its frequency across all the alternative equilibrium structures. However, such an entropy has yet to deliver the desired performance for distinguishing ncRNAs from random sequences. Developing novel methods to improve the entropy measure performance may result in more effective ncRNA gene finding based on structure detection. This paper shows that the measuring performance of base pairing entropy can be significantly improved with a constrained secondary structure ensemble in which only canonical base pairs are assumed to occur in energetically stable stems in a fold. This constraint actually reduces the space of the secondary structure and may lower the probabilities of base pairs unfavorable to the native fold. Indeed, base pairing entropies computed with this constrained model demonstrate substantially narrowed gaps of Z-scores between ncRNAs, as well as drastic increases in the Z-score for all 13 tested ncRNA sets, compared to shuffled sequences. These results suggest the viability of developing effective structure-based ncRNA gene finding methods by investigating secondary structure ensembles of ncRNAs.
Parasomnias of childhood.

Parasomnias occur in all children, especially in those of the preschool age. The clinical manifestations vary with time of onset relative to the wake–sleep interface or the type of sleep behavior disorders – rapid eye movement sleep or nonrapid eye movement sleep behavior disorders. It is important for the practitioner to be able to differentiate sleepwalking, sleep terrors, and confusional arousals from nocturnal seizures and panic attacks. Diagnostic issues and management of childhood parasomnias are discussed.
Sample Splitting and Threshold Estimation

.Threshold models have a wide variety of applications in economics. Direct applications include models of separating and multiple equilibria. Other applications include empirical sample splitting when the sample split is based on a continuously-distributed variable such as firm size. In addition, threshold models may be used as a parsimonious strategy for nonparametric function estimation. For example, the threshold autoregressive model .TAR is popular in the nonlinear time series literature. Threshold models also emerge as special cases of more complex statistical frameworks, such as mixture models, switching models, Markov switching models, and smooth transition threshold models. It may be important to understand the statistical properties of threshold models as a preliminary step in the development of statistical tools to handle these more complicated structures. Despite the large number of potential applications, the statistical theory of threshold estimation is undeveloped. It is known that threshold estimates are super-consistent, but a distribution theory useful for testing and inference has yet to be provided. This paper develops a statistical theory for threshold estimation in the regression context. We allow for either cross-section or time series observations. Least squares estimation of the regression parameters is considered. An asymptotic distribution theory . for the regression estimates the threshold and the regression slopes is developed. It is found that the distribution of the threshold estimate is nonstandard. A method to construct asymptotic confidence intervals is developed by inverting the likelihood ratio statistic. It is shown that this yields asymptotically conservative confidence regions. Monte Carlo simulations are presented to assess the accuracy of the asymptotic approximations. The empirical relevance of the theory is illustrated through an application to the multiple . equilibria growth model of Durlauf and Johnson 1995 .
Search for different links with the same Jones' type polynomials: Ideas from graph theory and statistical mechanics

We describe in this talk three methods of constructing different links with the same Jones type invariant. All three can be thought as generalizations of mutation. The first combines the satellite construction with mutation. The second uses the notion of rotant, taken from the graph theory, the third, invented by Jones, transplants into knot theory the idea of the Yang-Baxter equation with the spectral parameter (idea employed by Baxter in the theory of solvable models in statistical mechanics). We extend the Jones result and relate it to Traczyk’s work on rotors of links. We also show further applications of the Jones idea, e.g. to 3-string links in the solid torus. We stress the fact that ideas coming from various areas of mathematics (and theoretical physics) has been fruitfully used in knot theory, and vice versa. 0. Introduction. Exactly ten year ago, at spring of 1984, Vaughan Jones introduced his (Laurent) polynomial invariant of links, VL(t). He checked immediately that it distinguishes many knots which were not taken apart by the Alexander polynomial, e.g. the right handed trefoil knot from the left handed trefoil knot, and the square knot from the granny knot; Fig. 0.1. 1991 Mathematics Subject Classification: Primary: 57M25. Secondary: 82B.
DO MOTIVATED INSTITUTIONAL INVESTORS MONITOR FIRM PAYOUT AND PERFORMANCE

We document a positive relation between shareholder monitoring and total payout to shareholders using two monitoring proxies that jointly consider an investor's ability and incentive to monitor. We find that this relation is even stronger for firms with poor growth options and with greater potential for agency problems. Unlike traditional proxies, our two proxies do not exhibit any endogeneity with payout policy. We further show that monitoring is positively associated with future improvements in payout and operating performance. These findings are consistent with the prediction that shareholder monitoring leads to higher payout through increased efficiency and reduced agency costs.
Iterative correction of Hi-C data reveals hallmarks of chromosome organization

Extracting biologically meaningful information from chromosomal interactions obtained with genome-wide chromosome conformation capture (3C) analyses requires elimination of systematic biases. We present a pipeline that integrates a strategy for mapping of sequencing reads and a data-driven method for iterative correction of biases, yielding genome-wide maps of relative contact probabilities. We validate ICE (Iterative Correction and Eigenvector decomposition) on published Hi-C data, and demonstrate that eigenvector decomposition of the obtained maps provides insights into local chromatin states, global patterns of chromosomal interactions, and the conserved organization of human and mouse chromosomes.
Experimental and computational studies on the formation of cyanate from early metal terminal nitrido ligands and carbon monoxide

An important challenge in the artificial fixation of N2 is to find atom efficient transformations that yield value-added products. Here we explore the coordination complex mediated conversion of ubiquitous species, CO and N2, into isocyanate. We have conceptually split the process into three steps: (1) the six-electron splitting of dinitrogen into terminal metal nitrido ligands, (2) the reduction of the complex by two electrons with CO to form an isocyanate linkage, and (3) the one electron reduction of the metal isocyanate complex to regenerate the starting metal complex and release the product. These steps are explored separately in an attempt to understand the limitations of each step and what is required of a coordination complex in order to facilitate a catalytic cycle. The possibility of this cyanate cycle was explored with both Mo and V complexes which have previously been shown to perform select steps in the sequence. Experimental results demonstrate the feasibility of some of the steps and DFT calculations suggest that, although the reduction of the terminal metal nitride complex by carbon monoxide should be thermodynamically favorable, there is a large kinetic barrier associated with the change in spin state which can be avoided in the case of the V complexes by an initial binding of the CO to the metal center followed by rearrangement. This mandates certain minimal design principles for the metal complex: the metal center should be sterically accessible for CO binding and the ligands should not readily succumb to CO insertion reactions.
Kinetic State Tracking for a Class of Singularly Perturbed Systems

The trajectory-following control problem for a general class of nonlinear multi-input, multi-output two-time scale system is revisited. While most earlier works used singular perturbation theory and assumed that an isolated real root exists for the nonlinear set of algebraic equations that constitute the slow subsystem, here two-time scale systems are analyzed in the context of integral manifolds. This accounts for the existence of multiple roots. It is shown that the slow subsystem has a center manifold, and for small values of the slow state, an approximate solution of the nonlinear set of transcendental equations can be computed. Geometric singular perturbation theory is used as the model reduction technique, and dynamic inversion is used to formulate stabilizing control laws for slow state tracking. The control laws are independent of the scalar perturbation parameter, and an upper bound for it is determined such that boundedness of all the closed-loop signals is guaranteed. The methodology is validated through numerical simulation of a generic twodegree of freedom kinetic model and a nonlinear, coupled, six degree-of-freedom model of the F/A-18A Hornet. Results presented in the paper show that this methodology permits close tracking of the reference trajectory while maintaining all the control signals well within their specied bounds.
Temperature- and pH- Sensitive Hydrogels for Controlled Release of Antithrombotic Agents

Polymeric hydrogels capable of reversible swelling with changes in environmental temperature and pH were synthesized and studied as matrix systems capable of controlled release of antithrombotic drugs to the site of a blood clot. Monomers N-isopropylacrylamide (NIPAAm) and methacrylic acid (MAA) were chosen for the temperature- and pHdependent swelling characteristics of their polymers, respectively. Equilibrium swelling studies were performed as functions of pH and of temperature, and kinetic swelling studies were performed on the thermally responsive gels as a function of time after the gel was subjected to a step-change in temperature. Experimental results indicate that P(NIPAAmco- MAA) hydrogels can be synthesized so that they are either pH- or temperaturesensitive, depending upon the composition of the network. The pure PNIPAAm gels showed a lower critical solubility temperature (LCST) of around 32°C, below which the gel was in its swollen state, and above which the gel collapsed. As the amount of methacrylic acid in the gels was increased, the degree of swelling in deionized water decreased and the temperature sensitivity was lost. The hydrogels containing MAA displayed a transition in swelling behavior between pH 4 and 6. The mesh sizes of the hydrogel networks were calculated from the results of the swelling studies by Flory-Rehner theory. A kinetic experiment on the temperature-sensitive pure PNIPAAm hydrogel showed that the polymer network collapsed rapidly upon temperature changes across the LCST.
Designing Public Participation Processes

The purpose of this Theory to Practice article is to present a systematic, cross-disciplinary, and accessible synthesis of relevant research and to offer explicit evidence-based design guidelines to help practitioners design better participation processes. From the research literature, the authors glean suggestions for iteratively creating, managing, and evaluating public participation activities. The article takes an evidence-based and design science approach, suggesting that effective public participation processes are grounded in analyzing the context closely, identifying the purposes of the participation effort, and iteratively designing and redesigning the process accordingly.
Bolt-Bearing Fatigue of a Graphite/Epoxy Laminate

Graphite/epoxy laminates (T300/5208) were tested under bolt-bearing loads for a range of bolt clampup torques and for several test conditions involving water. High clampup torque improved both the static strength and fatigue limit by about 100 percent compared to a simple pin-bearing case, which had no through-the-thickness constraint. The static strength improvement was explained in terms of failure modes. Bolt clampup also influenced the hole elongation that developed before failure. For both the static and fatigue tests, the hole elongations were much larger for the low-torque-clampup case than for the pin-bearing case or for tests with moderate clampup torques. Tests in water degraded static bearing strength only slightly, but reduced the fatigue limit about 40 percent below that for tests conducted in air.
Non-LTE Models and Theoretical Spectra of Accretion Disks in Active Galactic Nuclei. II. Vertical Structure of the Disk

We have calculated several representative models of vertical structure of an accretion disk around a supermassive Kerr black hole. The interaction of radiation and matter is treated self-consistently, taking into account departures from LTE for calculating both the disk structure and the radiation -eld. The structural equations are described in detail, and various approximations are discussed. We have demon- strated that departures from LTE are very important for determining the disk structure, even at the midplane, as well as the emergent radiation, particularly for hot and electron-scatteringEdominated disks. We have shown that at least for the disk parameters studied in this paper, non-LTE e†ects tend to reduce the value of the Lyman jump with respect to the LTE predictions, regardless whether LTE pre- dicts an emission or absorption jump. We have studied the e†ects of various values of viscosity on the model structure and predicted spectral energy distribution. The viscosity is parameterized through a parameter that describes the vertically averaged viscous stress, two power-law exponents, and a 0 f 0 f 1 , and the division point between these two forms. The disk structure and emergent radiation is sensi- m d tive mainly to the values of while the other parameters inNuence the disk structure to a much lesser a 0 , extent. However, although the detailed shape of the predicted spectrum is sensitive to adopted value of the overall appearance of the spectrum is quite similar. a 0 , Subject headings: accretion, accretion disks E galaxies: active E galaxies: nuclei E radiative transfer
Informed Trading and the Market Reaction to Accounting Restatements

ABSTRACT We examine how informed trading activities affect the market reaction to accounting restatements. We find significantly less negative reactions to accounting restatements when managers are net purchasers of stock before the restatement, and significantly more negative market reactions when managers are net sellers. Similar patterns characterize corporate trading, where prior stock repurchases dampen negative reactions and prior equity issuances increase negative reactions to the restatement. We address the possibility of reverse causality in which informed trades are undertaken because of the expected market reaction by examining the difference between disclosed and non-disclosed trades, finding that the market reaction is concentrated in the disclosed trades. Our results are incremental to general return patterns associated with insider trading and corporate equity transactions, and hold after controlling for other determinants of the market reaction to restatements. Taken together, these findin...
CONSTRAINTS ON THE EFFECTS OF LOCALLY BIASED GALAXY FORMATION

While it is well known that "" biased galaxy formation II can increase the strength of galaxy clustering, it is less clear whether straightforward biasing schemes can change the shape of the galaxy correlation function on large scales. Here we consider "" local II biasing models, in which the galaxy density -eld at d g a point x is a function of the matter-density -eld d at that point: We consider both determin- d g \ f (d). istic biasing, where f is simply a function, and stochastic biasing, in which the galaxy-density is a d g random variable whose distribution depends on the matter density: We show that even when d g \ X(d). this mapping is performed on a highly nonlinear density -eld with a hierarchical correlation structure, the correlation function m is simply scaled up by a constant, as long as m > 1. In stochastic biasing models, the galaxy autocorrelation function behaves exactly as in deterministic models, with (the X(d) mean value of X for a given value of d) taking the role of the deterministic bias function. We extend our results to the power spectrum P(k), showing that for sufficiently small k the e†ect of local biasing is equivalent to the multiplication of P(k) by a constant, with the addition of a constant term. If a cosmo- logical model predicts a large-scale mass correlation function in conNict with the shape of the observed galaxy correlation function, then the model cannot be rescued by appealing to a complicated but local relation between galaxies and mass. Subject headings: galaxies: clusters: general E galaxies: formation E large-scale structure of universe
C–H oxidation by platinum group metal oxo or peroxo species

While C–H oxidation by ruthenium oxo compounds has been broadly applied in organic synthesis, examples of C–H oxidation by metal oxo complexes from the rest of the platinum group are still rare. We survey the preparation and reactivity of these late-transition metal oxo and peroxo complexes in this tutorial review.
Risk-based sensor management for integrated detection and estimation

In this paper, we develop a risk-based sensor management scheme for unknown object detection and process estimation under limited sensory resources. Bayesian sequential detection and estimation methods are utilized for risk analysis. The objective is to find every object of interest in the mission domain and satisfactorily estimate the associated process dynamics with minimum risks. Two types of costs are taken into account for risk evaluation, i.e., the cost of making an erroneous decision regarding object existence or its estimates, and the cost of taking more observations for a possibly better decision. The Renyi information divergence is investigated to measure the information loss in making a suboptimal sensor allocation decision, which is used to formulate the observation cost. A set of simulation results are provided to confirm the effectiveness of the proposed sensor management scheme.
Palladium-Catalyzed Regioselective Hydrodebromination of Dibromoindoles: Application to the Enantioselective Synthesis of Indolodioxane U86192A

A novel approach to the selective preparation of 4-bromoindoles was developed via Pd(OAc)2/rac-BINAP catalytic reactions. A variety of 4,6-dibromoindoles were transformed to 4-bromoindoles with high regioselectivity. This methodology, along with C−N and C−O bond-forming reactions developed in our laboratory, was applied to the enantioselective synthesis of indolodioxane U86192A, an antihypertensive agent.
Design of optics for the Final Focus Test Beam at SLAC

The goal of the Final Focus Test Beam experiment (FFTB) is to produce an electron beam spot of 1 mu m by 60 nm in transverse dimensions. Considering its future application to the TLC (TeV Linear Collider) the beam optics are designed so that the beta functions and the pole-tip field of the final quadrupole are the same as the TLC parameters. Previously, a very flat beam was regarded as suitable for the TLC. Thus, a method with single-family sextupoles was sufficient to correct the chromaticity. Recent studies however, reveal that e/sup +/e/sup -/-pair productions during beam collision generate a huge amount of background. In order to get out of the background, the 'crab-crossing' scheme is necessary. As a result, the optimum aspect ratio of the beta functions is reduced to less than 100, and chromaticity corrections for both planes become inevitable. In the design chosen, a new chromaticity correction scheme with noninterlaced two-family sextupoles is used. Optimization of the system is described, and tolerances and tuning methods are considered. >
High-speed videography using a dense camera array

We demonstrate a system for capturing multi-thousand frame-per-second (fps) video using a dense array of cheap 30 fps CMOS image sensors. A benefit of using a camera array to capture high-speed video is that we can scale to higher speeds by simply adding more cameras. Even at extremely high frame rates, our array architecture supports continuous streaming to disk from all of the cameras. This allows us to record unpredictable events, in which nothing occurs before the event of interest that could be used to trigger the beginning of recording. Synthesizing one high-speed video sequence using images from an array of cameras requires methods to calibrate and correct those cameras' varying radiometric and geometric properties. We assume that our scene is either relatively planar or is very far away from the camera and that the images can therefore be aligned using projective transforms. We analyze the errors from this assumption and present methods to make them less visually objectionable. We also present a new method to automatically color match our sensors. Finally, we demonstrate how to compensate for spatial and temporal distortions caused by the electronic rolling shutter, a common feature of low-end CMOS sensors.
The fundamental theorem of information theory from the sampling theorem point of view

The authors investigate the relationship between the nonuniform sampling theorem and the fundamental theorem of information theory. This analysis leads to an alternative method of error correction. They propose not to correct for the lost samples but rather to reconstruct the original signal from the rest of the samples using nonuniform sampling reconstruction techniques. This idea can be generalized to additive noise where the binary digits are in error but there is no erasure. >
On Dark Energy, Weyl’s Geometry, Different Derivations of the Vacuum Energy Density and the Pioneer Anomaly

Two different derivations of the observed vacuum energy density are presented. One is based on a class of proper and novel generalizations of the (Anti) de Sitter solutions in terms of a family of radial functions R(r) that provides an explicit formula for the cosmological constant along with a natural explanation of the ultraviolet/infrared (UV/IR) entanglement required to solve this problem. A nonvanishing value of the vacuum energy density of the order of $${10^{- 123} M_{\rm Planck}^4}$$ is derived in agreement with the experimental observations. A correct lower estimate of the mass of the observable universe related to the Dirac–Eddington–Weyl’s large number N = 1080 is also obtained. The presence of the radial function R(r) is instrumental to understand why the cosmological constant is not zero and why it is so tiny. Finally, we rigorously prove why the proper use of Weyl’s Geometry within the context of Friedman–Lemaitre–Robertson–Walker cosmological models can account for both the origins and the value of the observed vacuum energy density (dark energy). The source of dark energy is just the dilaton-like Jordan–Brans–Dicke scalar field that is required to implement Weyl invariance of the most simple of all possible actions. The full theory involving the dynamics of Weyl’s gauge field Aμ is very rich and may explain also the anomalous Pioneer acceleration and the temporal variations (over cosmological scales) of the fundamental constants resulting from the expansion of the Universe. This is consistent with Dirac’s old idea of the plausible variation of the physical constants but with the advantage that it is not necessary to invoke extra dimensions.
RNA structure generates natural cooperativity between single-stranded RNA binding proteins targeting 5′ and 3′UTRs

In post-transcriptional regulation, an mRNA molecule is bound by many proteins and/or miRNAs to modulate its function. To enable combinatorial gene regulation, these binding partners of an RNA must communicate with each other, exhibiting cooperativity. Even in the absence of direct physical interactions between the binding partners, such cooperativity can be mediated through RNA secondary structures, since they affect the accessibility of the binding sites. Here we propose a quantitative measure of this structure-mediated cooperativity that can be numerically calculated for an arbitrary RNA sequence. Focusing on an RNA with two binding sites, we derive a characteristic difference of free energy differences, i.e. ΔΔG, as a measure of the effect of the occupancy of one binding site on the binding strength of another. We apply this measure to a large number of human and Caenorhabditis elegans mRNAs, and find that structure-mediated cooperativity is a generic feature. Interestingly, this cooperativity not only affects binding sites in close proximity along the sequence but also configurations in which one binding site is located in the 5'UTR and the other is located in the 3'UTR of the mRNA. Furthermore, we find that this end-to-end cooperativity is determined by the UTR sequences while the sequences of the coding regions are irrelevant.