cssi/SciSciGPT-SciSciNet huggingface dataset:
Nonadiabatic geometric phase in quaternionic Hilbert space

We develop the theory of the nonadiabatic geometric phase, in both the Abelian and non-Abelian cases, in quaternionic Hilbert space.
Intercomparison of Electromagnetic Models for Passive Microwave Remote Sensing of Snow

Electromagnetic models can be used for understanding the interaction between electromagnetic waves and matter, interpreting experimental data, and retrieving geophysical parameters. Comparing the results of different snow models, when driven with the same set of input parameters, can benefit remote sensing of snow. Microwave brightness temperatures of snow at 19 and 37 GHz for six different classes of snow (prairie, tundra, taiga, alpine, maritime, and ephemeral) are simulated by means of four different electromagnetic models: the Helsinki University of Technology snow emission model, the microwave emission model of layered snowpacks, a dense-medium radiative-transfer theory model, and a strong fluctuation theory model. The frequency behavior of the extinction coefficients obtained with the different models between 5 and 90 GHz is also studied. The four models are also driven with inputs derived from snow-pit data, and the outputs are compared with ground-based measurements of brightness temperatures at 18.7 and 36.5 GHz. Significant differences among the brightness temperatures and the extinction coefficients simulated with the four models in the cases of the six classes of snow are observed. Moreover, no particular model is found to be able to systematically reproduce all of the experimental data. The results highlight the need to more closely examine the relationships relating mean grain size and correlation length, introduce multiple layers in each model, and to perform controlled laboratory measurements on materials with well-known electromagnetic properties in order to improve the understanding of the causes of the observed differences and to improve model performance
Highly Enantioselective Aldol Reaction: Development of a New Chiral Auxiliary from cis-1-Amino-2-hydroxyindan.

Boron enolates obtained from optically active oxazolidinone derivative of cis-1-amino-2-hydroxyindan are reacted with various aldehydes to provide highly enantioselective aldol products in good yields.
Invariances and equations of motion in double field theory

We investigate the full set of equations of motion in double field theory and discuss their O(D,D) symmetry and gauge transformation properties. We obtain a Ricci-like tensor, its associated Bianchi identities, and relate our results to those with a generalized metric formulation.
JML’s rich, inherited specifications for behavioral subtypes

The Java Modeling Language (JML) is used to specify detailed designs for Java classes and interfaces. It has a particularly rich set of features for specifying methods. This paper describes those features, with particular emphasis on the features related to specification inheritance. It shows how specification inheritance in JML forces behavioral subtyping, through a discussion of semantics and examples. It also describes a notion of modular reasoning based on static type information, supertype abstraction, which is made valid in JML by methodological restrictions on invariants, history constraints, and initially clauses and by behavioral subtyping.
Immediate Impact of Hurricane Sandy on People Who Inject Drugs in New York City

Over the eight months following Hurricane Sandy, of October 2012, we interviewed 300 people who inject drugs in New York City. During the week after the storm, 28% rescued others or volunteered with aid groups; 60% experienced withdrawal; 27% shared drug injection or preparation equipment, or injected with people they normally would not inject with; 70% of those on opioid maintenance therapy could not obtain sufficient doses; and 43% of HIV-positive participants missed HIV medication doses. Although relatively brief, a hurricane can be viewed as a Big Event that can alter drug environments and behaviors, and may have lasting impact. The study's limitations are noted and future needed research is suggested.
UNDERSTANDING PRAGMATICALLY ILL-FORMED INPUT

An utterance may be syntactically and semantically well-formed yet violate the pragmatic rules of the world model. This paper presents a context-based strategy for constructing a cooperative but limited response to pragmatically ill-formed queries. Suggestion heuristics use a context model of the speaker's task inferred from the preceding dialogue to propose revisions to the speaker's ill-formed query. Selection heuristics then evaluate these suggestions based upon semantic and relevance criteria.
Amine‐Free Approach toward N‐Toluenesulfonyl Amidine Construction: A Phosphite‐Mediated Beckmann‐Like Coupling of Oximes and p‐Toluenesulfonyl Azide

Atom hopping: A chlorophosphite-mediated Beckmann ligation of oximes and p-toluenesulfonyl azide gives access to N-sulfonyl phosphoramidines in good to excellent yields. The reaction proceeds under exceptionally mild conditions and constitutes a bioorthogonal approach toward amidines by avoiding the use of amines and transition-metal catalysts. dmp-ol=3,3-dimethylpropanediol.
Measuring Positive Externalities from Unobservable Victim Precaution: An Empirical Analysis of Lojack

Lojack is a hidden radio-transmitter device used for retrieving stolen vehicles. Because there is no external indication that Lojack has been installed, it does not directly affect the likelihood that a protected car will be stolen. There may, however, be positive externalities due to general deterrence. We find that the availability of Lojack is associated with a sharp fall in auto theft. Rates of other crime do not change appreciably. At least historically, the marginal social benefit of an additional unit of Lojack has been fifteen times greater than the marginal social cost in high crime areas. Those who install Lojack, however, obtain less than 10 percent of the total social benefits, leading to underprovision by the market.
Does it make sense to use scents to enhance brand memory

Abstract Can pleasant ambient scents enhance consumer memory for branded products? If so, why? The authors examine the effects of ambient scent on recall and recognition of brands in two studies. In the first (i.e., encoding) phase of each study, subjects are asked to evaluate familiar and unfamiliar brands while viewing digital photographs of products on a computer screen; stimulus viewing times are measured covertly on the computer. Ambient scent is manipulated in the experiment room through a diffuser. In the second (i.e., retrieval) phase, conducted 24-hours later, brand recall and recognition accuracy are assessed. In both studies, ambient scent improves both recall and recognition of familiar and unfamiliar brands. This pattern emerges whether or not the scent is congruent with the product category (Study 1), and the enhancement in brand memory is due to the presence of ambient scent during encoding rather than retrieval (Study 2). Although ambient scent apparently did not alter subjects’ self-asses...
Coherence of Teleseismic P and S waves across the Transportable Array

Abstract Design of large‐aperture broadband arrays and array stacking of waveforms for receiver function studies critically depend on the coherence of waveforms across an array. The coherence of teleseismic P and S waves in the 0.05–1.6 Hz frequency band has been examined using high signal‐to‐noise teleseisms recorded by the USArray Transportable Array. Instrument‐corrected, time‐windowed, and rotated P and S waves were filtered in five, single‐octave frequency bands and then correlated to determine coherence in each band. The normalized correlation coefficient is used as a measure of relative coherence and plotted as a function of interstation distance, which is used as a proxy for horizontal wavelength. Up to ∼100,000 unique station correlation pairs can be found for vertical component P and transverse component S . Coherence of teleseismic P waves across the USArray is seen to be uniformly high in the frequency band between 0.05 and 0.4 Hz, with average correlation coefficients of 0.8 or greater for over 10 horizontal wavelengths. P ‐wave coherence degrades at higher frequency, although coherence is still higher than 0.6 for lower mantle propagation paths. S ‐wave coherence is relatively less robust but is greater than 0.8 for the 0.05–0.2 Hz frequency band, again for lower mantle propagation paths. Average coherence drops for both P and S waves for frequency bands greater than 0.2 Hz at station distances influenced by wave propagation through the upper mantle. This characteristic of wave propagation in the Earth can be used to design high‐resolution broadband phased arrays for detailed studies of large earthquake sources and Earth structure and increases confidence in using vertical stacks of P waves as effective source functions in regional receiver function analysis.
Analytic Continuation of Dirichlet Series with Almost Periodic Coefficients

We consider Dirichlet series \({\zeta_{g,\alpha}(s)=\sum_{n=1}^\infty g(n\alpha) e^{-\lambda_n s}}\) for fixed irrational α and periodic functions g. We demonstrate that for Diophantine α and smooth g, the line Re(s) = 0 is a natural boundary in the Taylor series case λn = n, so that the unit circle is the maximal domain of holomorphy for the almost periodic Taylor series \({\sum_{n=1}^{\infty} g(n\alpha) z^n}\). We prove that a Dirichlet series \({\zeta_{g,\alpha}(s) = \sum_{n=1}^{\infty} g(n \alpha)/n^s}\) has an abscissa of convergence σ0 = 0 if g is odd and real analytic and α is Diophantine. We show that if g is odd and has bounded variation and α is of bounded Diophantine type r, the abscissa of convergence σ0 satisfies σ0 ≤ 1 − 1/r. Using a polylogarithm expansion, we prove that if g is odd and real analytic and α is Diophantine, then the Dirichlet series ζg,α(s) has an analytic continuation to the entire complex plane.
A six-phase multilevel inverter for MEMS electrostatic induction micromotors

The construction of miniaturized rotating electric machines through microfabrication techniques is becoming a reality. Applications of such micromotors include miniaturized pumps, compressors, fans, coolers, and turbogenerators. However, the characteristics of these devices make the design of power electronics for them challenging. These characteristics include high-voltage and high frequency operation, tightly constrained operating waveforms and timing, and capacitive input impedances. This paper explores the design of power electronics for microfabricated electrostatic induction machines. We describe the structure and operation of these machines, and establish the operating requirements of power converters for them. We provide a comparison of inverter topologies for this application, and propose an appropriate architecture. The design and experimental evaluation of a prototype six-phase, five-level inverter for this application is presented. The inverter operates at frequencies up to 2 MHz and at voltages up to 300 V, and meets the stringent waveform and timing constraints posed by this application.
Delta modulation strategies for resonant link inverters

The suitability of delta modulation strategies for resonant link inverters is explored in detail. The control and spectral characteristics of various delta modulators are examined in an effort to develop a model for the same. The more fundamental question of comparing delta modulation systems with conventional pulse-width-modulated (PWM) systems, given similar devices, is addressed, and it shown that the former provides a viable high-performance alternative. As the resonant DC link topology allows at least an order of magnitude increase in the switching frequency, Sigma Delta M systems using a given family of devices are capable of better spectral response than a conventional PWM inverter. >
Accounting for product substitution in the analysis of food taxes targeting obesity

We extend the existing literature on food taxes targeting obesity. We systematically incorporate the implicit substitution between added sugars and solid fats into a comprehensive food demand system and evaluate the effect of taxes on sugars and fats. The approach conditions how food and obesity taxes affect total calorie intake. The proposed methodology accounts for the ability of consumers to substitute leaner low-fat and low-sugar items for rich food items within the same food group. This substitution is integrated into a calibrated demand system in addition to the substitution among food groups, using recent food intake data and existing demand elasticities. Simulations of taxes on added sugars and solid fat show that their impact on consumption patterns is understated and the induced welfare loss is overstated when abstracting from the substitution possibilities within food groups.
Deoxygenation of Aromatic Ketones Using Transfer Hydrogenolysis with Raney Nickel in 2-Propanol

Abstract Aryl ketones are readily deoxygenated to their corresponding aryl alkanes upon treatment with Raney nickel catalyst in boiling 2-propanol.
Chiral bis(oxazoline) copper(II) complexes: versatile catalysts for enantioselective cycloaddition, Aldol, Michael, and carbonyl ene reactions.

A bis(oxazoline) (box) copper(II) complex and its hydrated counterpart (1 and 2) function as enantioselective Lewis acid catalysts for carbocyclic and hetero Diels−Alder, aldol, Michael, ene, and amination reactions with substrates capable of chelation through six- and five-membered rings. X-ray crystallography of the chiral complexes reveals a propensity for the formation of distorted square planar or square pyramidal geometries. The sense of asymmetric induction is identical for all the processes catalyzed by [Cu((S,S)-t-Bu-box)](X)2 complexes 1 and 2 (X = OTf and SbF) resulting from the intervention of a distorted square planar catalyst-substrate binary complex. These catalyzed processes exhibit excellent temperature−selectivity profiles. Reactions catalyzed by [Cu(S,S-Ph-pybox)](SbF6)2 and their derived chelation complexes are also discussed.
A Hydrothermal Investigation of the 1/2V2O5−H2C2O4/H3PO4/NH4OH System: Synthesis and Structures of (NH4)VOPO4·1.5H2O, (NH4)0.5VOPO4·1.5H2O, (NH4)2[VO(H2O)3]2[VO(H2O)][VO(PO4)2]2·3H2O, and (NH4)2[VO(HPO4)]2(C2O4)·5H2O

The 1/2V2O5−H2C2O4/H3PO4/NH4OH system was investigated using hydrothermal techniques. Four new phases, (NH4)VOPO4·1.5H2O (1), (NH4)0.5VOPO4·1.5H2O (2), (NH4)2[VO(H2O)3]2[VO(H2O)][VO(PO4)2]2·3H2O (3), and (NH4)2[VO(HPO4)]2(C2O4)·H2O (4), have been prepared and structurally characterized. Compounds 1 and 2 have layered structures closely related to VOPO4·2H2O and A0.5VOPO4·yH2O (A = mono- or divalent metals), whereas 3 has a 3D open-framework structure. Compound 4 has a layered structure and contains both oxalate and phosphate anions coordinated to vanadium cations. Crystal data: (NH4)VOPO4·1.5H2O, tetragonal (I), space group I4/mmm (No. 139), a = 6.3160(5) A, c = 13.540(2) A, Z = 4; (NH4)0.5VOPO4·1.5H2O, monoclinic, space group P21/m (No. 11), a = 6.9669(6) A, b = 17.663(2) A, c = 8.9304(8) A, β = 105.347(1)°, Z = 8; (NH4)2[VO(H2O)3]2[VO(H2O)][VO(PO4)2]2·3H2O, triclinic, space group P1 (No. 2), a = 10.2523(9) A, b = 12.263(1) A, c = 12.362(1) A, α = 69.041(2)°, β = 65.653(2)°, γ = 87.789(2)°, Z = 2; (NH4...
2‐Methylhopanoids are maximally produced in akinetes of Nostoc punctiforme: geobiological implications

2-Methylhopanes, molecular fossils of 2-methylbacteriohopanepolyol (2-MeBHP) lipids, have been proposed as biomarkers for cyanobacteria, and by extension, oxygenic photosynthesis. However, the robustness of this interpretation is unclear, as 2-methylhopanoids occur in organisms besides cyanobacteria and their physiological functions are unknown. As a first step toward understanding the role of 2-MeBHP in cyanobacteria, we examined the expression and intercellular localization of hopanoids in the three cell types of Nostoc punctiforme: vegetative cells, akinetes, and heterocysts. Cultures in which N. punctiforme had differentiated into akinetes contained approximately 10-fold higher concentrations of 2-methylhopanoids than did cultures that contained only vegetative cells. In contrast, 2-methylhopanoids were only present at very low concentrations in heterocysts. Hopanoid production initially increased threefold in cells starved of nitrogen but returned to levels consistent with vegetative cells within 2 weeks. Vegetative and akinete cell types were separated into cytoplasmic, thylakoid, and outer membrane fractions; the increase in hopanoid expression observed in akinetes was due to a 34-fold enrichment of hopanoid content in their outer membrane relative to vegetative cells. Akinetes formed in response either to low light or phosphorus limitation, exhibited the same 2-methylhopanoid localization and concentration, demonstrating that 2-methylhopanoids are associated with the akinete cell type per se. Because akinetes are resting cells that are not photosynthetically active, 2-methylhopanoids cannot be functionally linked to oxygenic photosynthesis in N. punctiforme.
Branching rules in the ring of superclass functions of unipotent upper-triangular matrices

It is becoming increasingly clear that the supercharacter theory of the finite group of unipotent upper-triangular matrices has a rich combinatorial structure built on set-partitions that is analogous to the partition combinatorics of the classical representation theory of the symmetric group. This paper begins by exploring a connection to the ring of symmetric functions in non-commuting variables that mirrors the symmetric group’s relationship with the ring of symmetric functions. It then also investigates some of the representation theoretic structure constants arising from the restriction, tensor products and superinduction of supercharacters in this context.
Decision-Making Approaches and the Propensity to Default: Evidence and Implications

Abstract This paper examines heterogeneity in the responsiveness to default options in a large state retirement plan, focusing on individuals’ decision-making approaches as well as their economic and demographic characteristics. Analyses of a survey of plan participants show that procrastination and the need for cognitive closure are important determinants of the likelihood of default. This paper also explores an important implication of defaulting—individuals who default are significantly more likely to subsequently express a desire to enroll in a different plan. The desire to change plans is also correlated with numerous economic and decision-making characteristics, including procrastination.
Synthesis of indenes by the transition metal-mediated carboannulation of alkynes

The synthesis of highly substituted indenes has been achieved by three different transition metal-mediated methods. The first method involves the palladium-catalyzed carboannulation of internal alkynes. The second method utilizes a two-step approach, which involves first the palladium/copper-catalyzed cross-coupling of terminal alkynes with appropriately functionalized aryl halides, followed by copper-catalyzed intramolecular cyclization. The third method involves intermolecular palladium-catalyzed arylation of the arylalkynes formed in the first step of the second method.
Locally connected models for Julia sets

Let P be a polynomial with a connected Julia set J. We use continuum theory to show that it admits a finest monotone map φ onto a locally connected continuum J∼P, i.e. a monotone map φ:J→J∼P such that for any other monotone map ψ:J→J′ there exists a monotone map h with ψ=h∘φ. Then we extend φ onto the complex plane C (keeping the same notation) and show that φ monotonically semiconjugates P|C to a topological polynomial g:C→C. If P does not have Siegel or Cremer periodic points this gives an alternative proof of Kiwi's fundamental results on locally connected models of dynamics on the Julia sets, but the results hold for all polynomials with connected Julia sets. We also give a characterization and a useful sufficient condition for the map φ not to collapse all of J into a point.
Methodological issues in experimental IS research: experiences and recommendations

Within the last ten years the use of experimental methodology in information systems (IS) research has substantially increased. However, despite our experience with experimentation, studies continue to suffer from methodological problems. These problems have led to an accumulation of conflicting results in several areas of IS research. Moreover, future research studies will keep producing contradictory results unless researchers begin to answer questions of task and measurement validity before reporting their experimental findings. This article discusses common methodological problems in experimental IS studies and, through a description of a series of graphics experiments at the University of Minnesota, illustrates the particularly acute problem of low internal validity. Suggestions are offered to experimental IS researchers on how some of these common problems can be alleviated or even avoided, particularly in studies on the use of managerial graphics.
Physical activity reduces prostate carcinogenesis in a transgenic model.

BACKGROUND Several epidemiological studies have reported an inverse association between physical activity and the risk of prostate cancer. To date, there are few animal studies looking at physical activity and cancer incidence, although the results are consistent with the epidemiological evidence. In general, as exercise intensity increased in the rats/mice, the likelihood that physical activity inhibited carcinogenesis increased. METHODS The present study used voluntary wheel running with C3(1)Tag mice that are predisposed to prostate cancer due to the directed expression of SV40 oncogenes. After 10 weeks, the prostates were collected from run and non-run mice and histopathology performed for the presence or absence of low grade or high grade PINS. RESULTS We found that for those mice that ran >5Km/group, 83% of the dorsolateral prostates were classified as within normal levels vs. 43% for the <5 km/day group (p = 0.16). In addition, there was a relationship between average distance run and pathologic progression to high-grade PIN and local invasion, considered to be an early event in the formation of prostate adenocarcinoma. Forty three percent of dorsalateral prostates from mice that ran less than 5 km/day were classified with advanced pathology as compared to none (0) in mice that ran more than 5.0 km/day (p = 0.05). CONCLUSIONS The results presented herein indicate that prostatic cancer progression is likely delayed or diminished by wheel running activity in a dose dependent manner in transgenic mice. These findings provide further evidence that exercise acts to decrease the progression of prostate cancer and they establish a transgenic animal model for future studies to define mechanism(s). Prostate 69: 1372–1377, 2009. © 2009 Wiley-Liss, Inc.
A simple and accurate discontinuous Galerkin scheme for modeling scalar-wave propagation in media with curved interfaces

ABSTRACTConventional high-order discontinuous Galerkin (DG) schemes suffer from interface errors caused by the misalignment between straight-sided elements and curved material interfaces. We have developed a novel DG scheme to reduce those errors. Our new scheme uses the correct normal vectors to the curved interfaces, whereas the conventional scheme uses the normal vectors to the element edge. We modify the numerical fluxes to account for the curved interface. Our numerical modeling examples demonstrate that our new discontinuous Galerkin scheme gives errors with much smaller magnitudes compared with the conventional scheme, although both schemes have second-order convergence. Moreover, our method significantly suppresses the spurious diffractions seen in the results obtained using the conventional scheme. The computational cost of our scheme is similar to that of the conventional scheme. The new DG scheme we developed is, thus, particularly useful for large-scale scalar-wave modeling involving complex s...
The Case for Restricting Fiscal Policy Discretion

This paper studies the effects of discretionary fiscal policy on output volatility and economic growth. Using data for 91 countries, we isolate three empirical regularities: (1) governments that use fiscal policy aggressively induce significant macroeconomic instability; (2) the volatility of output caused by discretionary fiscal policy lowers economic growth by more than 0.8 percentage points for every percentage point increase in volatility; (3) prudent use of fiscal policy is explained to a large extent by the presence of political constraints and other political and institutional variables. The evidence in the paper supports arguments for constraining discretion by imposing institutional restrictions on governments as a way to reduce output volatility and increase the rate of economic growth.
What Can the Cosmic Microwave Background Tell Us about the Outer Solar System

We discuss two new observational techniques that use observations of the cosmic microwave background (CMB) to place constraints on the mass, distance, and size distribution of small objects in the Kuiper Belt and inner Oort Cloud, collectively known as trans-Neptunian objects (TNOs). The first new technique considers the spectral distortion of the isotropic, or monopole, CMB by TNOs that have been heated by solar radiation to temperatures above that of the CMB. We apply this technique to the spectral measurements of the CMB by the Far Infrared Absolute Spectrophotometer on the Cosmic Background Explorer. The second technique utilizes the change in amplitude of the TNO signal due to the orbital motion of the observer to separate the TNO signal from the invariant extragalactic CMB and construct a map of the mass distribution in the outer solar system. We estimate the ability of future CMB experiments to create such a map.
Asymptotic stability of the Toda m-soliton

We prove that multi-soliton solutions of the Toda lattice are both linearly and nonlinearly stable. Our proof uses neither the inverse spectral method nor the Lax pair of the model but
Sparse factor analysis for learning and content analytics

We develop a new model and algorithms for machine learning-based learning analytics, which estimate a learner's knowledge of the concepts underlying a domain, and content analytics, which estimate the relationships among a collection of questions and those concepts. Our model represents the probability that a learner provides the correct response to a question in terms of three factors: their understanding of a set of underlying concepts, the concepts involved in each question, and each question's intrinsic difficulty. We estimate these factors given the graded responses to a collection of questions. The underlying estimation problem is ill-posed in general, especially when only a subset of the questions are answered. The key observation that enables a well-posed solution is the fact that typical educational domains of interest involve only a small number of key concepts. Leveraging this observation, we develop both a bi-convex maximum-likelihood-based solution and a Bayesian solution to the resulting SPARse Factor Analysis (SPARFA) problem. We also incorporate user-defined tags on questions to facilitate the interpretability of the estimated factors. Experiments with synthetic and real-world data demonstrate the efficacy of our approach. Finally, we make a connection between SPARFA and noisy, binary-valued (1-bit) dictionary learning that is of independent interest.
Rolling Manipulation with a Single Control

Underactuated manipulation is the process of controlling several object degrees-of-freedom with fewer robot actuators. Underactuated manipulation allows us to build dexterous robots with only a few...
Directional multiscale modeling of images using the contourlet transform

The contourlet transform is a new two-dimensional extension of the wavelet transform using multiscale and directional filter banks. The contourlet expansion is composed of basis images oriented at various directions in multiple scales, with flexible aspect ratios. Given this rich set of basis images, the contourlet transform effectively captures smooth contours that are the dominant feature in natural images. We begin with a detailed study on the statistics of the contourlet coefficients of natural images: using histograms to estimate the marginal and joint distributions and mutual information to measure the dependencies between coefficients. This study reveals the highly non-Gaussian marginal statistics and strong interlocation, interscale, and interdirection dependencies of contourlet coefficients. We also find that conditioned on the magnitudes of their generalized neighborhood coefficients, contourlet coefficients can be approximately modeled as Gaussian random variables. Based on these findings, we model contourlet coefficients using a hidden Markov tree (HMT) model with Gaussian mixtures that can capture all interscale, interdirection, and interlocation dependencies. We present experimental results using this model in image denoising and texture retrieval applications. In denoising, the contourlet HMT outperforms other wavelet methods in terms of visual quality, especially around edges. In texture retrieval, it shows improvements in performance for various oriented textures.
Stochastic fluid modulus inversion

A probabilistic inversion approach is used with Gassmann's equation to determine pore fluid modulus using elastic wave velocity without reference information from a rock saturated with a second fluid of known modulus. Numerical examples show that even when uncertainties in input parameters are relatively large, useful estimates of fluid modulus can be obtained. For a well‐log data example, water saturation derived from the inverted fluid modulus compares favorably to saturations derived from well log analysis.
Energy Coupon: A Mean Field Game Perspective on Demand Response in Smart Grids

We consider the problem of a Load Serving Entity (LSE) trying to reduce its exposure to electricity market volatility by incentivizing demand response in a Smart Grid setting. We focus on the day-ahead electricity market, wherein the LSE has a good estimate of the statistics of the wholesale price of electricity at different hours in the next day, and wishes its customers to move a part of their power consumption to times of low mean and variance in price. Based on the time of usage, the LSE awards a differential number of "Energy Coupons" to each customer in proportion to the customer's electricity usage at that time. A lottery is held periodically in which the coupons held by all the customers are used as lottery tickets. Our study takes the form of a Mean Field Game, wherein each customer models the number of coupons that each of its opponents possesses via a distribution, and plays a best response pattern of electricity usage by trading off the utility of winning at the lottery versus the discomfort suffered by changing its usage pattern. The system is at a Mean Field Equilibrium (MFE) if the number of coupons that the customer receives is itself a sample drawn from the assumed distribution. We show the existence of an MFE, and characterize the mean field customer policy as having a multiple-threshold structure in which customers who have won too frequently or infrequently have low incentives to participate. We then numerically study the system with a candidate application of air conditioning during the summer months in the state of Texas. Besides verifying our analytical results, we show that the LSE can potentially attain quite substantial savings using our scheme. Our techniques can also be applied to resource sharing problems in other \emph{societal} networks such as transportation or communication.
Foreign aid and rent-seeking

To address the relationship between concessional assistance, corruption, and other types of rent-seeking activities, the author provides a simple game-theoretic rent-seeking model. Insights with interesting implications emerge from the analysis: 1) An increase in government revenue (from windfalls, for example, or from increased foreign aid) does not necessarily lead to the provision of more public goods and in certain circumstances may reduce it. 2) The mere expectation of aid may suffice to increase rent-dissipation and reduce productive public spending. But if the donor community can enter into a binding policy commitment, this result may be reversed. The author provides some preliminary empirical evidence in support of the hypothesis that windfalls and foreign aid, in countries suffering from a divided policy process, are on average associated with more extensive corruption. He finds no evidence that donors systematically allocate aid to countries with less corruption. The results accords with recent empirical findings that aid is more effective, the greater the effort to direct it to good performers. But such a regime shift may involve an aid policy that in the short run provides more assistance to countries in less need and less aid to those in most need. Enforcing such a regime shift might be difficult.
Early Response-to-Intervention Measures and Criteria as Predictors of Reading Disability in the Beginning of Third Grade

We explored the usefulness of first and second grade reading measures and responsiveness criteria collected within a response-to-intervention (RtI) framework for predicting reading disability (RD) in third grade. We used existing data from 387 linguistically diverse students who had participated in a longitudinal RtI study. Model-based predictors of RD were analyzed using logistic regression; isolated measure/criteria combinations for predicting RD were analyzed using classification analysis. Models yielded superior classification rates compared to single measure approaches and did not systematically misclassify English learners. However, particular first and second grade measure/criteria combinations also showed promise as isolated predictors of RD in word reading/text fluency. Model-based approaches were required for acceptable classification of students with RD in comprehension. Although the former finding is promising for early identification of students in need of more intensive instruction in lexical or fluency-based skills, the latter finding reaffirms literature attesting to the complexity of RD in comprehension and difficulty of predicting deficits using early measures of reading, which primarily assess word reading skill. Results replicated well with an independent sample, thus enhancing confidence in study conclusions. Implications regarding the use of RtI for predicting RD are discussed.
Analysis and parameter selection for an adaptive random search algorithm

This paper presents an analysis of an adaptive random search (ARS) algorithm, a global minimization method. A probability model is introduced to characterize the statistical properties of the number of iterations required to find an acceptable solution. Moreover, based on this probability model, a new stopping criterion is introduced to predict the maximum number of iterations required to find an acceptable solution with a pre-specified level of confidence. Finally, this paper presents a systematic procedure for choosing the user-specified parameters in the ARS algorithm for fastest convergence. The results, which are valid for search spaces of arbitrary dimensions, are illustrated on a simple three-dimensional example.
Co-channel interference mitigation in the time-scale domain: the CIMTS algorithm

In many communication systems, the problem of co-channel interference is encountered when along with the signal of interest (SOI), and one or more interfering signals are present in a common receiver. The SOI and the interference are correlated, possess similar characteristics and power, and share the same region of support both in the time and frequency domains. In this paper, we present co-channel interference mitigation in the time-scale domain (CIMTS) algorithm (for MPSK signals) which estimates the SOI and the interfering signal from their superposition in the presence of additive noise. This method is inspired by the reconstruction of interference from the null space of the SOI in the time-scale domain. Once the null space of the SOI is determined, the interfering signal is reconstructed via a set of linear operations. Therefore, the SOI is estimated by a simple subtraction of the estimated interference from the observations.
Using linear time-invariant system theory to estimate kinetic parameters directly from projection measurements

It is common practice to estimate kinetic parameters from dynamically acquired tomographic data by first reconstructing a dynamic sequence of three-dimensional reconstructions and then fitting the parameters to time activity curves generated from the time-varying reconstructed images. However, in SPECT, the pharmaceutical distribution can change during the acquisition of a complete tomographic data set, which can bias the estimated kinetic parameters. It is hypothesized that more accurate estimates of the kinetic parameters can be obtained by fitting to the projection measurements instead of the reconstructed time sequence. Estimation from projections requires the knowledge of their relationship between the tissue regions of interest or voxels with particular kinetic parameters and the projection measurements, which results in a complicated nonlinear estimation problem with a series of exponential factors with multiplicative coefficients. A technique is presented in this paper where the exponential decay parameters are estimated separately using linear time-invariant system theory. Once the exponential factors are known, the coefficients of the exponentials can be estimated using linear estimation techniques. Computer simulations demonstrate that estimation of the kinetic parameters directly from the projections is more accurate than the estimation from the reconstructed images.
Ocean mediation of tropospheric response to reflecting and absorbing aerosols

Abstract. Radiative forcing by reflecting (e.g., sulfate, SO4) and absorbing (e.g., black carbon, BC) aerosols is distinct: the former cools the planet by reducing solar radiation at the top of the atmosphere and the surface, without largely affecting the atmospheric column, while the latter heats the atmosphere directly. Despite the fundamental difference in forcing, here we show that the structure of the tropospheric response is remarkably similar between the two types of aerosols, featuring a deep vertical structure of temperature change (of opposite sign) at the Northern Hemisphere (NH) mid-latitudes. The deep temperature structure is anchored by the slow response of the ocean, as a large meridional sea surface temperature (SST) gradient drives an anomalous inter-hemispheric Hadley circulation in the tropics and induces atmospheric eddy adjustments at the NH mid-latitudes. The tropospheric warming in response to projected future decline in reflecting aerosols poses additional threats to the stability of mountain glaciers in the NH. Additionally, robust tropospheric response is unique to aerosol forcing and absent in the CO2 response, which can be exploited for climate change attribution.
Efficient Garbling from a Fixed-Key Blockcipher

We advocate schemes based on fixed-key AES as the best route to highly efficient circuit-garbling. We provide such schemes making only one AES call per garbled-gate evaluation. On the theoretical side, we justify the security of these methods in the random-permutation model, where parties have access to a public random permutation. On the practical side, we provide the Just Garble system, which implements our schemes. Just Garble evaluates moderate-sized garbled-circuits at an amortized cost of 23.2 cycles per gate (7.25 nsec), far faster than any prior reported results.
Stability of mid-latitude snowpacks on Mars

Abstract Christensen [2003. Nature 422, 45–48] suggested that runoff from melting snowpacks on martian slopes might be responsible for carving gullies. He also suggested that snowpacks currently exist on Mars, for example on the walls of Dao Valles (approximately 33° S). Such snowpacks were presumably formed during the last obliquity cycle, which occurred about 70,000 years ago. In this paper we investigate a specific scenario under conditions we believe are favorable for snowpack melting. We model the rate at which a snowpack located at 33° S on a poleward-facing slope sublimates and melts on Mars, as well as the temperature profile within the snowpack. Our model includes the energy and mass balance of a snowpack experiencing diurnal variations in insolation. Our results indicate that a dirty snowpack would quickly sublimate and melt under current martian climate conditions. For example a 1 m thick dusty snowpack of moderate density (550 kg/m3) and albedo (0.39) would sublimate in less than two seasons, producing a small amount of meltwater runoff. Similarly, a cleaner snowpack (albedo 0.53) would disappear in less than 9 seasons. These results suggest that the putative snowpack almost certainly could not have survived for 70,000 years. For most of the parameter settings snowpack interior temperatures at this latitude and slope do reach the melting point. Under most conditions melting occurs when the snowpack is less than 10 cm thick. The modeled snowpack will not melt if it is covered by a 1 cm dust lag. In general, these findings raise interesting possibilities regarding gully formation, but perhaps mostly during a past climate regime when snowfall was expected to have occurred. If there currently are exposed snowpacks on martian mid-latitude slopes, then these ice sheets cannot last long. Hence they might be time variable features on Mars and should be searched for.
Preparation of Cyan Dyes from 6-Diethylaminobenzo[b]furan-2-carboxaldehyde

6-Diethylaminobenzo[b]furan-2-carboxaldehyde was synthesized in four steps and 48% overall yield starting from 4-diethylaminosalicylaldehyde. Five cyan dyes were made from this aldehyde using malononitrile dimer and 2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran. The crystal structures of two dyes are included.
Density theorems for bipartite graphs and related Ramsey-type results

In this paper, we present several density-type theorems which show how to find a copy of a sparse bipartite graph in a graph of positive density. Our results imply several new bounds for classical problems in graph Ramsey theory and improve and generalize earlier results of various researchers. The proofs combine probabilistic arguments with some combinatorial ideas. In addition, these techniques can be used to study properties of graphs with a forbidden induced subgraph, edge intersection patterns in topological graphs, and to obtain several other Ramsey-type statements.
SN2′ addition/1,2-elimination of dimethylsulfonium methylide with epoxy vinyl sulfones: synthesis of exocyclic cross-conjugated dienyl sulfones

Dimethylsulfonium methylide undergoes SN2′ addition/1,2-elimination with epoxy vinyl sulfones to generate enantiopure six and seven membered cross-conjugated hydroxy vinyl sulfones. Moderate to excellent yields were obtained for both six and seven membered substrates.
Chemical Vapor Deposition Modeling for High Temperature Materials

The formalism for the accurate modeling of chemical vapor deposition (CVD) processes has matured based on the well established principles of transport phenomena and chemical kinetics in the gas phase and on surfaces. The utility and limitations of such models are discussed in practical applications for high temperature structural materials. Attention is drawn to the complexities and uncertainties in chemical kinetics. Traditional approaches based on only equilibrium thermochemistry and/or transport phenomena are defended as useful tools, within their validity, for engineering purposes. The role of modeling is discussed within the context of establishing the link between CVD process parameters and material microstructures/ properties. It is argued that CVD modeling is an essential part of designing CVD equipment and controlling/optimizing CVD processes for the production and/or coating of high performance structural materials.
Hicksian Welfare Measures and the Normative Endowment Effect

C corresponds to the consumer’s willingness to pay (WTP) to effectuate the welfare change, while the equivalent variation E measures the consumer’s willingness to accept (WTA) to reverse the welfare change. In the interesting case where both measures are finite, the changes in the consumer’s income prescribed by C and E exactly offset the welfare change either before or after it takes place. The monetary variations mea sure the income effect of the welfare change, either from an ex ante or an ex post perspective. More generally, both of these Hicksian welfare measures can be used for the evaluation of any change of state (which implies a change of welfare ), as long as the agent’s indirect utility for income is well-defined before and after the change. Our aim is to examine the properties of WTA and WTP as a function of income and to clarify the normative relationship between them. The latter helps in refocussing empirical efforts to measure the well-known endowment effect. We provide an exact relation between compensating and equivalent variation (Proposition 2); one can be obtained from the other by evaluating it at a suit
Can Agent Cheap Talk Mitigate Agency Problems in the Presence of a Noisy Performance Measure? An Experimental Test in a Single- and Multi-Period Setting

ABSTRACT: Given traditional agency theory assumptions and unobservable effort in a single-period setting, a moral hazard arises in which the agent is expected to shirk and provide the minimal possible effort after contracting with the principal. Traditional solutions to this agency problem include paying the agent a financial incentive tied to some noisy measure of performance or allowing the agent to develop a reputation over multiple periods. As the noisiness of the performance measure increases, however, these traditional solutions become increasingly costly and ineffective. In many single- and multi-period agency settings in the firm, however, the agent can communicate a promised level of effort to the principal prior to contracting. We document that this pre-contract communication, which is non-enforceable and therefore considered “cheap talk” by traditional economic theory, can be highly effective in mitigating the moral hazard problem in agency theory. In a repeating single-period experimental set...
Observing a Black Hole Event Horizon: (Sub)Millimeter VLBI of Sgr A*

Very strong evidence suggests that Sagittarius A*, a compact radio source at the center of the Milky Way, marks the position of a super massive black hole. The proximity of Sgr A* in combination with its mass makes its apparent event horizon the largest of any black hole candidate in the universe and presents us with a unique opportunity to observe strong-field GR effects. Recent millimeter very long baseline interferometric observations of Sgr A* have demonstrated the existence of structures on scales comparable to the Schwarzschild radius. These observations already provide strong evidence in support of the existence of an event horizon. (Sub)Millimeter VLBI observations in the near future will combine the angular resolution necessary to identify the overall morphology of quiescent emission, such as an accretion disk or outflow, with a fine enough time resolution to detect possible periodicity in the variable component of emission. In the next few years, it may be possible to identify the spin of the black hole in Sgr A*, either by detecting the periodic signature of hot spots at the innermost stable circular orbit or parameter estimation in models of the quiescent emission. Longer term, a (sub)millimeter VLBI “Event Horizon Telescope” will be able to produce images of the Galactic center emission to the see the silhouette predicted by general relativistic lensing. These techniques are also applicable to the black hole in M87, where black hole spin may be key to understanding the jet-launching region.