cssi/SciSciGPT-SciSciNet huggingface dataset:
Investigating causal relations by econometric models and cross-spectral methods

There occurs on some occasions a difficulty in deciding the direction of causality between two related variables and also whether or not feedback is occurring. Testable definitions of causality and feedback are proposed and illustrated by use of simple two-variable models. The important problem of apparent instantaneous causality is discussed and it is suggested that the problem often arises due to slowness in recordhag information or because a sufficiently wide class of possible causal variables has not been used. It can be shown that the cross spectrum between two variables can be decomposed into two parts, each relating to a single causal arm of a feedback situation. Measures of causal lag and causal strength can then be constructed. A generalization of this result with the partial cross spectrum is suggested.The object of this paper is to throw light on the relationships between certain classes of econometric models involving feedback and the functions arising in spectral analysis, particularly the cross spectrum and the partial cross spectrum. Causality and feedback are here defined in an explicit and testable fashion. It is shown that in the two-variable case the feedback mechanism can be broken down into two causal relations and that the cross spectrum can be considered as the sum of two cross spectra, each closely connected with one of the causations. The next three sections of the paper briefly introduce those aspects of spectral methods, model building, and causality which are required later. Section IV presents the results for the two-variable case and Section V generalizes these results for three variables.
Introduction to Theory and Practice in Marketing Conference Special Section of Marketing Science

This special section is the result of an effort by several scholars to move marketing academic research toward greater practical relevance. This initiative, called Theory + Practice in Marketing TPM, started with a conference at Columbia Business School in 2011, and the five papers published in this special section were presented at the second TPM conference held at Harvard Business School in 2012.
Exact thermodynamics of pairing and charge–spin separation crossovers in small Hubbard nanoclusters

Abstract The exact numerical diagonalization and thermodynamics in an ensemble of small Hubbard clusters in the ground state and finite temperatures reveal intriguing insights into the nascent charge and spin pairings, Bose condensation and ferromagnetism in nanoclusters. The phase diagram off half filling strongly suggests the existence of quantum critical points and subsequent transitions from electron pairing into unsaturated and saturated ferromagnetic Mott–Hubbard like insulators, driven by electron repulsion. Rigorous criteria for the existence of quantum critical points and crossover temperatures are formulated. The phase diagram for 2 × 4 -site clusters illustrates how these features are scaled with cluster size. The phase separation and electron pairing, monitored by a magnetic field and electron doping, surprisingly resemble phase diagrams in the family of doped high- T c cuprates.
Segmentation of nerve bundles and ganglia in spine MRI using particle filters

Automatic segmentation of spinal nerve bundles that originate within the dural sac and exit the spinal canal is important for diagnosis and surgical planning. The variability in intensity, contrast, shape and direction of nerves seen in high resolution myelographic MR images makes segmentation a challenging task. In this paper, we present an automatic tracking method for nerve segmentation based on particle filters. We develop a novel approach to particle representation and dynamics, based on Bezier splines. Moreover, we introduce a robust image likelihood model that enables delineation of nerve bundles and ganglia from the surrounding anatomical structures. We demonstrate accurate and fast nerve tracking and compare it to expert manual segmentation.
The role of the range parameter for estimation and prediction in geostatistics

SUMMARY Two canonical problems in geostatistics are estimating the parameters in a specified family of stochastic process models and predicting the process at new locations. We show that asymptotic results for a Gaussian process over a fixed domain with Mat´ ern covariance function, previously proven only in the case of a fixed range parameter, can be extended to the case of jointly estimating the range and the variance of the process. Moreover, we show that intuition and approximations derived from asymptotics using a fixed range parameter can be problematic when applied to finite samples, even for large sample sizes. In contrast, we show via simulation that performance is improved and asymptotic approximations are applicable for smaller sample sizes when the parameters are jointly estimated. These effects are particularly apparent when the process is mean square differentiable or the effective range of spatial correlation is small.
Mars microrover navigation: performance evaluation and enhancement

In 1996, NASA will launch the Mars Pathfinder spacecraft, which will carry an 11 kg rover to explore the immediate vicinity of the lander. To assess the capabilities of the rover, the authors have constructed a new microrover testbed consisting of the Rocky 3.2 vehicle and an indoor test arena containing Mars analog terrain and overhead cameras for automatic, real-time tracking of the true rover position and heading. In this paper, the authors present initial performance evaluation results obtained with this testbed. The authors first decompose rover navigation into four major functions: goal designation, rover localization, hazard detection, and path selection. The authors then describe the Mars Pathfinder approach to each function, present results to date of evaluating the performance of each function, and outline their approach to enhancing performance for future missions. The results show key limitations in the quality of rover localization, the speed of hazard detection, and the ability of behavior control algorithms for path selection to negotiate the rock frequencies likely to be encountered on Mars.
Quantum cryptographic ranging

We present a system to measure the distance between two parties that allows only trusted people to access the result. The security of the protocol is guaranteed by the complementarity principle in quantum mechanics. The protocol can be realized with available technology, at least as a proof of principle experiment.
#AdvocatingForChange: The Strategic Use of Hashtags in Social Media Advocacy

Social media continues to change how advocacy organizations mobilize, educate, and connect with their constituents. One of the most unique yet understudied tools available on social media platforms is the hashtag. Little research exists on how social work and advocacy organizations use hashtags, much less on how such use can be effective. This study examines the hashtag use by 105 constituent members of the National Health Council, a national US-based patient/health advocacy coalition. The study presents an inductive coding scheme of the types of hashtags employed, analyzes inter-sectoral differences in hashtag usage, and examines the relationship between hashtag use and measures of the effectiveness of social media messages.
Enantioselective Ag-Catalyzed Allylation of Aldimines.

A highly enantioselective synthesis of homoallylic amines, using allyltrimethoxysilane under AgI catalytic conditions, has been developed. Among the chiral ligands investigated, a remarkable difference in the resulting AgI complexes was observed. Under mild conditions and low catalyst loadings, homoallylamines were produced in high ee values (up to 80 %) and good yields. The methodology can be further extended to a diastere- and enantioselective crotylation of aldimines.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Aggregate and Firm-Level Measures of Systemic Risk from a Structural Model of Default

The breadth and dynamics of the recent financial crisis have led to efforts to develop forward-looking tools to monitor systemic risk. In this article, the authors propose a new measure that is an extension of the absorption ratio (AR) introduced in 2010 by Kritzman, Li, Page, and Rigobon. Using principal component analysis (as in the original AR methodology) in conjunction with a structural model of default, the authors develop a measure of systemic risk that may be calculated using only publicly available data. They call the new measure the credit absorption ratio (CAR) and find that increases in the CAR preceded periods of financial distress during the recent crisis. The CAR may be interpreted economically: it highlights states of the financial system during which the credit fundamentals of institutions and markets exhibit heightened coupling and higher potential for cascading distress. The authors also demonstrate that a byproduct of CAR analysis provides a measure of the degree to which specific financial institutions are exposed to systemic risk factors at any point in time. They find that a number of the institutions that exhibited, under the CAR measure, high potential exposure during the lead-up to the recent crisis subsequently experienced higher levels of distress or required external assistance.
Performance analysis of broadcast protocols in ad hoc networks based on self-pruning

Self-pruning is an effective scheme for efficient broadcasting in ad hoc wireless networks. In a self-pruning broadcast protocol, a node may not forward a broadcast packet if a certain self-pruning condition is satisfied based on the neighborhood information. In a static network with an ideal MAC layer, only a subset of nodes forward the broadcast packet and still guarantee the complete network delivery. Various protocols have been proposed with different self-pruning conditions. Recently, a generic self-pruning protocol was proposed by Wu and Dai (2003), which combines the strength of previous conditions and is more effective. In this paper, we first propose an enhanced version of the generic protocol, which is more elegant in interpreting existing protocols and has a simpler correctness proof. Then, we evaluate the performance of the family of self-pruning protocols under various network situations with ns2. The objective is to observe the efficiency and reliability of these protocols as a function of network density, congestion, and mobility, and provide a guideline of implementation in the "real world". Our performance analysis reveals that the protocol reliability is barely affected by packet collision. However, most self-pruning protocols suffer from low delivery ratio in highly mobile networks. We further explore various techniques that improve the delivery ratio and show that both high efficiency and reliability can be achieved in highly mobile networks.
Model-free model-fitting and predictive distributions

The problem of prediction is revisited with a view towards going beyond the typical nonparametric setting and reaching a fully model-free environment for predictive inference, i.e., point predictors and predictive intervals. A basic principle of model-free prediction is laid out based on the notion of transforming a given setup into one that is easier to work with, namely i.i.d. or Gaussian. As an application, the problem of nonparametric regression is addressed in detail; the model-free predictors are worked out, and shown to be applicable under minimal assumptions. Interestingly, model-free prediction in regression is a totally automatic technique that does not necessitate the search for an optimal data transformation before model fitting. The resulting model-free predictive distributions and intervals are compared to their corresponding model-based analogs, and the use of cross-validation is extensively discussed. As an aside, improved prediction intervals in linear regression are also obtained.
Fiscal Decentralization and Public Sector Size in Australia

This paper examines the impact ofjiscaldecentralization and intergovernmental collusion, and the resultingjiscal dependence, on the size of the public sector in Australia Contrary to evidence for the United States. fscal decentralization is found to have no impact on public sector sue in Australia Three possible explanations for this finding were suggested the relatively small number of lowerlevel government$. the economic insignifiance of local governments; und the relative immobility of citizens Fiscal dependence of State governments on the Commonwealth proves a signifKant determinant of public sector size, consistent with fwdings for the United States.
Preparation of Functionalized Alkylmagnesium Derivatives Using an I/Mg-Exchange

Functionalized alkylmagnesium reagents bearing an acetal, a ketal, an ester, or a pyridine ring were prepared by an I/Mg-exchange using iPr2Mg·LiCl or ClMg(CH2)5MgCl·2LiCl starting from functionalized primary alkyl iodides.
Desperately seeking supersymmetry (SUSY)

The discovery of x-rays and radioactivity in the waning years of the 19th century led to one of the most awe-inspiring scientific eras in human history. The 20th century witnessed a level of scientific discovery never before seen or imagined. At the dawn of the 20th century only two forces of nature were known—gravity and electromagnetism. The atom was believed by chemists to be the elemental, indestructible unit of matter, coming in many unexplainably different forms. Yet J J Thomson, soon after the discovery of x-rays, had measured the charge to mass ratio of the electron, demonstrating that this carrier of electric current was ubiquitous and fundamental. All electrons could be identified by their unique charge to mass ratio.In the 20th century the mystery of the atom was unravelled, the atomic nucleus was smashed, and two new forces of nature were revealed—the weak force (responsible for radioactive β decay and the nuclear fusion reaction powering the stars) and the nuclear force binding the nucleus. Quantum mechanics enabled the understanding of the inner structure of the atom, its nucleus and further inward to quarks and gluons (the building blocks of the nucleus) and thence outward to an understanding of large biological molecules and the unity of chemistry and microbiology.Finally the myriad of new fundamental particles, including electrons, quarks, photons, neutrinos, etc and the three fundamental forces—electromagnetism and the weak and the strong nuclear forces—found a unity of description in terms of relativistic quantum field theory. These three forces of nature can be shown to be a consequence of symmetry rotations in internal spaces, and the particular interactions of each particle are solely determined by their symmetry charge. This unifying structure, describing all the present experimental observations, is known as the standard model (SM). Moreover, Einstein's theory of gravity can be shown to be a consequence of the symmetry of local translations and Lorentz transformations.As early as the 1970s, it became apparent that two new symmetries, a grand unified theory of the strong, weak and electromagnetic interactions in conjunction with supersymmetry (SUSY), might unify all the known forces and particles into one unique structure. Now 30 years later, at the dawn of a new century, experiments are on the verge of discovering (or ruling out) these possible new symmetries of nature. In this paper we try to clarify why SUSY and supersymmetric grand unified theories are the new SM of particle physics, i.e. the standard against which all other theories and experiments are measured.
Mass Balancing of Hollow Fan Blades

A typical section model is used to analytically investigate the effect of mass balancing as applied to hollow, supersonic fan blades. A procedure to determine the best configuration of an internal balancing mass to provide flutter alleviation is developed. This procedure is applied to a typical supersonic shroudless fan blade which is unstable in both the solid configuration and when it is hollow with no balancing mass. The addition of an optimized balancing mass is shown to stabilize the blade at the design condition.
Palladium-catalyzed hydrogenolysis of acyldimethylphenylsilanes to aldehydes

Abstract Syn-α,β-dialkoxy-acyldimethylphenylsilanes of structural type 1 , bearing benzyl, benzyloxymethyl (BOM) ether protecting groups can be efficiently and selectively desilated to produce the corresponding aldehydes 2 by catalytic hydrogenolysis over 10% palladium on carbon in ethanol or ethyl acetate.
Error characterization in quantum information processing: A protocol for analyzing spatial correlations and its experimental implementation

We present a protocol for error characterization and its experimental implementation with four qubits in liquid state NMR. The method is designed to retrieve information about spatial correlations and scales as $O({n}^{w})$, where $w$ is the maximum number of qubits that have non-negligible interaction. We discuss the practical aspects regarding accuracy and implementation.
Consistent representative democracy

We study axioms which define “representative democracy” in an environment in which agents vote over a finite set of alternatives. We focus on a property that states that whether votes are aggregated directly or indirectly makes no difference. We call this property representative consistency. Representative consistency formalizes the idea that a voting rule should be immune to gerrymandering. We characterize the class of rules satisfying unanimity, anonymity, and representative consistency. We call these rules “partial priority rules.” A partial priority rule can be interpreted as a rule in which each agent can “veto” certain alternatives. We investigate the implications of imposing other axioms to the list specified above. We also study the partial priority rules in the context of specific economic models.
New synthesis of IF5O

Abstract Phosphorus trifluoride oxide readily replaces two fluorine ligands in IF 7 for a doubly bonded oxygen atom, thereby providing a new and convenient synthesis for IF 5 O. Attempts to extend this method to the syntheses of either IF 3 O 2 or IFO 3 were unsuccessful due to competing deoxygenation reactions of the iodine oxyfluoride precursors. Furthermore, PF 3 O does not undergo fluorine-oxygen exchange with the NF 4 + cation.
Object-Oriented Analysis, Modeling, and Simulation of a Notional Air Defense System

This paper describes the analysis, modeling, and simulation of a notional air defense system using SMOOCHES (State Machines for Object-Oriented, Concurrent, Hierarchical Engineering Specifications)...
Client Perceptions of MAS Quality as Measured by a Marketing-Based Service Quality Model

Management Advisory Services (MAS) are an increasingly important part of the service mix for CPA firms. The growth of MAS relative to audit has been phenomenal over the past two decades. However, little research has been conducted on MAS provided by CPA firms. The primary purpose of this study was to examine the determinants of MAS quality from the client's perspective. To achieve this objective, 305 controllers of U.S. companies responded to a questionnaire regarding MAS provided by CPA firms. The questionnaire was designed using determinants from marketing and audit literature. Using these client perception dimensions, two types of MAS engagements were compared: those with an increase in cost during the engagement, and those with no increase in cost. Descriptive and statistical results indicate that a 13‐item service quality scale significantly differentiates client perceptions of MAS quality. The results also reflect dimensions of service quality that are similar to existing marketing and auditing stud...
Removing Impediments to Sustainable Economic Development: The Case of Corruption

This paper examines causes and consequences of corruption within the process of economic development. It starts by reviewing some of the factors that, over the past couple of decades, have transformed corruption from a subject on the sidelines of economic research to a central preoccupation of policy makers and donors in many countries. Drawing on a vast treasure trove of experiences and insights accumulated during the postwar period and reflected in a growing body of academic research, the paper analyzes many of the institutional mechanisms that sustain corruption and the impact of corruption on development. This paper argues that many forms of corruption stem from the distributional attributes of the state in its role as the economy's central agent of resource allocation. What is the impact of corruption on public finances and on the characteristics and performance of the private sector? What distortions does corruption introduce in the allocation of resources and in the relationships among economic agents in the marketplace? The paper also addresses the question of what can be done about corruption and discusses the role of economic policies in developing the right sorts of incentives and institutions to reduce the incidence of corruption. Particular attention is paid to business regulation, subsidies, the budget process, international conventions, and the role of new technologies. The paper concludes with some thoughts on the moral dimensions of corruption.
The Changing Role of Nominal Government Bonds in Asset Allocation

The covariance between nominal bonds and stocks has varied considerably over recent decades and has even switched sign. It has been predominantly positive in periods such as the late 1970s and early 1980s when the economy has experienced supply shocks and the central bank has lacked credibility. It has been predominantly negative in periods such as the 2000s when investors have feared weak aggregate demand and deflation. Nominal bonds are attractive to short-term equity investors when these bonds are negatively correlated with stocks, as has been the case during the 2000s and especially during the downturn of 2007–2008. They are attractive to conservative long-term investors when long-term inflationary expectations are stable, for then these bonds are close substitutes for inflation-indexed bonds that are riskless in the long term.
A Fractional Analogue of Brooks' Theorem

Let $\Delta(G)$ be the maximum degree of a graph G. Brooks' theorem states that the only connected graphs with chromatic number $\chi(G)=\Delta(G)+1$ are complete graphs and odd cycles. We prove a fractional analogue of Brooks' theorem in this paper. Namely, we classify all connected graphs G such that the fractional chromatic number $\chi_f(G)$ is at least $\Delta(G)$. These graphs are complete graphs, odd cycles, $C^2_8$, $C_5\boxtimes K_2$, and graphs whose clique number $\omega(G)$ equals the maximum degree $\Delta(G)$. Among the two sporadic graphs, the graph $C^2_8$ is the square graph of cycle $C_8$, while the other graph $C_5\boxtimes K_2$ is the strong product of $C_5$ and $K_2$. In fact, we prove a stronger result: If a connected graph G with $\Delta(G)\geq 4$ is not one of the graphs listed above, then we have $\chi_f(G)\leq \Delta(G)- \frac{2}{67}$.
Automated Construction of Sparse Bayesian Networks from Unstructured Probabilistic Models and Domain Information

Abstract An algorithm for automated construction of a sparse Bayesian network given an unstructured probabilistic model and causal domain information from an expert has been developed and implemented. The goal is to obtain a network that explicitly reveals as much information regarding conditional independence as possible. The network is built incrementally adding one node at a time. The expert's information and a greedy heuristic that tries to keep the number of arcs added at each step to a minimum are used to guide the search for the next node to add. The probabilistic model is a predicate that can answer queries about independencies in the domain. In practice the model can be implemented in various ways. For example, the model could be a statistical independence test operating on empirical data or a deductive prover operating on a set of independence statements about the domain.
OpenMG: A New Multigrid Implementation in Python

In many large-scale computations, systems of equations arise in the form Au= b, where A is a linear operation to be performed on the unknown data u, producing the known right-hand side, b, which represents some constraint of known or assumed behavior of the system being modeled. Since such systems can be very large, solving them directly can be too slow. In contrast, a multigrid solver solves partially at full resolution, and then solves directly only at low resolution. This creates a correction vector, which is then interpolated to full resolution, where it corrects the partial solution. This project aims to create an open-source multigrid solver called OpenMG, written only in Python. The exist- ing PyAMG multigrid implementation is a highly versatile, configurable, black- box solver, but is difficult to read and modify due to its C core. Our proposed OpenMG is a pure Python experimentation environment for testing multigrid concepts, not a production solver. By making the code simple and modular, we make the algorithmic details clear. We thereby create an opportunity for education and experimentation with the partial solver (Jacobi, Gauss Seidel, SOR, etc.), the restriction mechanism, the prolongation mechanism, and the direct solver, or the use of GPGPUs, multiple CPUs, MPI, or grid computing. The resulting solver is tested on an implicit pressure reservoir simulation problem with satisfactory results.
Carbon chains and rings in the laboratory and in space.

Abstract Seventy-seven reactive organic molecules of astrophysical interest have been identified in a supersonic molecular beam, 73 in the radio band by Fourier-transform microwave spectroscopy, four in the optical by laser cavity ringdown spectroscopy. Most are linear carbon chains, but six consist of carbon chains attached to the compact, highly polar C3 ring, and two are rhomboidal cyclic configurations of SiC3. The laboratory astrophysics of the radio molecules is complete for the time being, in the sense that essentially all the rotational transitions of current interest to radio astronomy (including hyperfine structure when present) can now be calculated to a small fraction of 1 km s-1 in equivalent radial velocity; six of the radio molecules have already been detected in space on the basis of the present data. The FTM spectrometer employed in this work is far from fundamental limits of sensitivity, so many more molecules can probably be found by refinements of present techniques. The density of reactive molecules in our supersonic beam is generally high by the standards of laser spectroscopy, and many of the radio molecules probably have detectable optical transitions which we are attempting to find, largely motivated by the long-standing problem of the diffuse interstellar bands. Our most interesting result to date is the detection of a fairly strong molecular band at 443 nm in a benzene discharge, in exact coincidence with the strongest and best known interstellar band. Isotopic shifts measured with partially and totally deuterated benzene suggest that the carrier of the laboratory band is a hydrocarbon molecule with the elemental formula CnH5, with n most likely in the range 3–6.
1,4-Diazabicyclo[2.2.2]octane as an Efficient Catalyst for a Clean, One-Pot Synthesis of Tetrahydrobenzo[b]pyran Derivatives via Multicomponent Reaction in Aqueous Media

Abstract 1,4-Diazabicyclo[2.2.2]octane (DABCO) has been used as a mild and efficient catalyst for the synthesis of various tetrahydrobenzo[b]pyran derivatives via a one-pot, three component condensation of aromatic aldehydes, dimedone, and active methylene compounds. This method provides several advantages: a simple workup procedure, environmental friendliness, neutral conditions, and good yields. In addition, water or 50% aqueous ethanol was chosen as a green solvent.
Security and the Political Economy of International Migration

How does migration affect the security of advanced industrial states and how does the security environment shape the way states deal with international migration? Migration rests at the nexus of three dimensions of security including geopolitical interests material production and internal security. I argue that migration policy is an integral instrument of state grand strategy in this context and that examining levels of threat on each facet of security at a given point in time can largely explain variation in policy. I test a series of hypotheses drawn from this security framework using a case-study method that examines policy development in four advanced industrial states including the United States Germany France and Great Britain in the period 1945-present. (authors)
Rozansky–Witten invariants via Atiyah classes

Recently, L. Rozansky and E. Witten associated to any hyper-Kahler manifold X a system of ‘weights’ (numbers, one for each trivalent graph) and used them to construct invariants of topological 3-manifolds. We give a simple cohomological definition of these weights in terms of the Atiyah class of X (the obstruction to the existence of a holomorphic connection). We show that the analogy between the tensor of curvature of a hyper-Kahler metric and the tensor of structure constants of a Lie algebra observed by Rozansky and Witten, holds in fact for any complex manifold, if we work at the level of cohomology and for any Kahler manifold, if we work at the level of Dolbeault cochains. As an outcome of our considerations, we give a formula for Rozansky–Witten classes using any Kahler metric on a holomorphic symplectic manifold.
Is assortative matching efficient

This paper develops some general conditions under which complementarities between individual agents imply that assortative matching is efficient. Our analysis has four main findings. First, when agents are organized into equal-sized groups, just as in Becker (1973), the presence of within-group complementarities is sufficient for stratification to be efficient. Second, if group sizes vary, assortative matching may not be efficient even though complementarities are present, unless particular functional form assumptions are imposed. Third, the connection between assortative matching, complementarities and efficiency reemerges if one considers sequences of replications of the economy in which individual coalitions are uniformly bounded in size. Fourth, the presence of feedbacks from the composition of group memberships has important effects on efficient allocations and breaks any simple link between assortative matching and efficiency. Together, these results suggest that the characterization of the cross-section evolution of an efficiently sorted economy is likely to be highly complex.
Design guidelines for landmarks to support navigation in virtual environments

Unfamiliar, large-scale virtual environments are difficult to navigate. This paper presents design guidelines to ease navigation in such virtual environments. The guidelines presented here focus on the design and placement of landmarks in virtual environments. Moreover, the guidelines are based primarily on the extensive empirical literature on navigation in the real world. A rationale for this approach is provided by the similarities between navigational behavior in real and virtual environments.
Multiscale Fields of Patterns

We describe a framework for defining high-order image models that can be used in a variety of applications. The approach involves modeling local patterns in a multiscale representation of an image. Local properties of a coarsened image reflect non-local properties of the original image. In the case of binary images local properties are defined by the binary patterns observed over small neighborhoods around each pixel. With the multiscale representation we capture the frequency of patterns observed at different scales of resolution. This framework leads to expressive priors that depend on a relatively small number of parameters. For inference and learning we use an MCMC method for block sampling with very large blocks. We evaluate the approach with two example applications. One involves contour detection. The other involves binary segmentation.
Optimal array pattern synthesis using semidefinite programming

We present algorithms for the solution of two problems in array pattern synthesis. The first is the design of nonuniform arrays with a desired magnitude response. The second is that of robust design, i.e., design in the presence of uncertainties. Constraints such as power limitation can be addressed with both problems. The algorithms that we present are based on semidefinite programming, for which efficient software is readily available. We present examples that illustrate the effectiveness of our approach.
Rights of Animals, Perceptions of Science, and Political Activism: Profile of American Animal Rights Activists

This article reports original research examining characteristics of the active followers of the American animal rights movement. Typical respondents were Caucasian, highly educated urban professional women approximately thirty years old with a median income of $33,000 (1989). Most activists think of themselves as Democrats or as Independents, and have moderate to liberal political views. They were often suspicious of science and made no distinction between basic and applied science, or public versus private animal-based research. The research suggests that animal rights activism is part of a symbolic manifestation of egalitarian social and political views concerning scientific and technological change.
Financial integration, housing, and economic volatility

Abstract The Great Recession illustrates the sensitivity of the economy to housing. This paper shows that financial integration, fostered by securitization and nationwide branching, amplified the positive effect of housing price shocks on the economy during the 1994–2006 period. We exploit variation in credit supply subsidies across local markets from government-sponsored enterprises to measure housing price changes unrelated to fundamentals. Using this instrument, we find that house price shocks spur economic growth. The effect is larger in localities more financially integrated, through both secondary loan market and bank branch networks. Financial integration thus raised the effect of collateral shocks on local economies, increasing economic volatility.
Multi-armed bandits in metric spaces

In a multi-armed bandit problem, an online algorithm chooses from a set of strategies in a sequence of $n$ trials so as to maximize the total payoff of the chosen strategies. While the performance of bandit algorithms with a small finite strategy set is quite well understood, bandit problems with large strategy sets are still a topic of very active investigation, motivated by practical applications such as online auctions and web advertisement. The goal of such research is to identify broad and natural classes of strategy sets and payoff functions which enable the design of efficient solutions. In this work we study a very general setting for the multi-armed bandit problem in which the strategies form a metric space, and the payoff function satisfies a Lipschitz condition with respect to the metric. We refer to this problem as the "Lipschitz MAB problem". We present a complete solution for the multi-armed problem in this setting. That is, for every metric space (L,X) we define an isometry invariant Max Min COV(X) which bounds from below the performance of Lipschitz MAB algorithms for $X$, and we present an algorithm which comes arbitrarily close to meeting this bound. Furthermore, our technique gives even better results for benign payoff functions.
Strain-Free Sextet-Resonant Benzenoids and Their Antisextet Dualists

By introducing antisextet dualists of sextet-resonant benzenoids that have only "full" and "empty" rings as defined by Clar, it was possible to devise a simple algorithm for an exhaustive enumeration of such sextet-resonant benzenoids (SRBs). Several relationships between invariants of such SRBs are described. All possible SRBs with up to 10 sextet rings are enumerated. A unique coding of SRBs is presented, based on the peripheral "sextet-polyphenyl-necklace" formed by the benzenoid rings circumscribing the SRB.
Reversible simulation of bipartite product Hamiltonians

Consider two quantum systems A and B interacting according to a product Hamiltonian H=H/sub A//spl ominus/H/sub B/. We show that any two such Hamiltonians can be used to simulate each other reversibly (i.e., without efficiency losses) with the help of local unitary operations and local ancillas. Accordingly, all nonlocal features of a product Hamiltonian - including the rate at which it can be used to produce entanglement, transmit classical or quantum information, or simulate other Hamiltonians - depend only upon a single parameter. We identify this parameter and use it to obtain an explicit expression for the entanglement capacity of all product Hamiltonians. Finally, we show how the notion of simulation leads to a natural formulation of measures of the strength of a nonlocal Hamiltonian.
Interview Interruption and Responses to Questions About Domestic Violence in India

This article uses the National Family Health Survey 2005-2006 (NFHS-3) of India to examine the relationship between interview interruption and the reporting of domestic violence. A sample of 65,610 currently married women was used to compare reported acts of physical and sexual violence among women who had been interrupted during their interview and those who had not. Logistic regression analyses indicated that women whose interviews were interrupted by either an adult man or woman were significantly more likely to report intimate partner violence.
Reproductive Issues in Women with Turner Syndrome

Turner syndrome is one of the most common chromosomal abnormalities affecting female infants. The severity of clinical manifestations varies and it affects multiple organ systems. Women with Turner syndrome have a 3-fold increase in mortality, which becomes even more pronounced in pregnancy. Reproductive options include adoption or surrogacy, assisted reproductive techniques, and in rare cases spontaneous pregnancy. Risks for women with Turner syndrome during pregnancy include aortic disorders, hepatic disease, thyroid disease, type 2 diabetes, and cesarean section delivery. Providers must be familiar with the risks and recommendations in caring for women with Turner syndrome of reproductive age.
High-Output Generation of Aerosols with Narrow Size Distributions

AbstractTwo aerosol generators–a small particle generator (SPG) and a large particle generator (LPG)–were designed and fabricated to produce water-soluble particles with high mass output and narrow size distributions. The mass median aerodynamic diameter (MMAD) of solid particles produced could be varied by changing operation conditions and using different concentrations of sodium chloride (NaCl) solutions. The aerosol generation rate varied from about 0.2 to 24 mg/min depending upon the particle size produced as the geometric standard deviation (GSD) was maintained below 1.5. The SPG employed a Collison-type nebulizer with multiple nozzles and a solid-plate impactor, which removes generating droplets larger than the cutpoint diameter for the production of submicrometer aerosols with GSD < 1.5. Different combinations of nebulization pressure/cutpoint diameter were selected to produce solid particles with MMAD in the range of 0.13–1.0 μm. The LPG was consisted of a Delavan simplex nozzle installed at the b...
Minimum Cost Distributed Source Coding Over a Network

This paper considers the problem of transmitting multiple compressible sources over a network at minimum cost. The aim is to find the optimal rates at which the sources should be compressed and the network flows using which they should be transmitted so that the cost of the transmission is minimal. We consider networks with capacity constraints and linear cost functions. The problem is complicated by the fact that the description of the feasible rate region of distributed source coding problems typically has a number of constraints that is exponential in the number of sources. This renders general purpose solvers inefficient. We present a framework in which these problems can be solved efficiently by exploiting the structure of the feasible rate regions coupled with dual decomposition and optimization techniques such as the subgradient method and the proximal bundle method.
On the steady nature of line-driven disk winds

We perform an analytic investigation of the steady nature of line-driven disk winds, independent of hydrodynamic simulations. Our motive is to determine whether line-driven disk winds can account for the wide/broad UV resonance absorption lines seen in cataclysmic variables (CVs) and quasi-stellar objects (QSOs). In both CVs and QSOs, observations generally indicate that the absorption arising in the outflowing winds has a steady velocity structure on timescales exceeding years (for CVs) and decades (for QSOs). However, published results from hydrodynamic simulations of line-driven disk winds are mixed, with some researchers claiming that the models are inherently unsteady, while other models produce steady winds. The analytic investigation presented here shows that the line-driven disk winds can be steady if the accretion disk is steady and capable of locally supplying the corresponding mass flow. In particular, we show that a gravitational force initially increasing along the wind streamline, which is characteristic of disk winds, does not imply an unsteady wind. The steady nature of line-driven disk winds is consistent with the one-dimensional streamline disk wind models of Murray and collaborators and the 2.5-dimensional time-dependent models of Pereyra and collaborators. This paper emphasizes the underlying physics behind the steady nature of line-driven disk winds using mathematically simple models that mimic the disk environment.
Ranking tweets considering trust and relevance

The increasing popularity of Twitter and other microblogs makes improved trustworthiness and relevance assessment of microblogs evermore important. We propose a method of ranking of tweets considering trustworthiness and content based popularity. The analysis of trustworthiness and popularity exploits the implicit relationships between the tweets. We model microblog ecosystem as a three-layer graph consisting of: (i) users (ii) tweets and (iii) web pages. We propose to derive trust and popularity scores of entities in these three layers, and propagate the scores to tweets considering the inter-layer relations. Our preliminary evaluations show improvement in precision and trustworthiness over the baseline methods and acceptable computation timings.
New indenyl phosphinooxazoline complexes of iron and their catalytic activity in the Mukaiyama aldol reaction

Abstract New phosphinooxazoline (PHOX) η 5 -indenyl complexes of iron were synthesized and applied as catalysts in the Mukaiyama aldol reaction. Reaction of three different PHOX ligands with [Fe(η 5 -Ind)I(CO) 2 ] afforded the iodide salts of three complexes of the general formula [Fe(η 5 -Ind)(CO)(PHOX)] + in 73–81% isolated yields. The molecular structure of one of the new complexes was determined, revealing a pseudo octahedral coordination geometry about the iron center. The iron complexes are catalytically active in the Mukaiyama aldol reaction between aldehydes and 1-( tert -butyldimethylsilyloxy)-1-methoxyethene to give the corresponding aldol adducts (3 mol % catalyst, 15 min, room temperature, 48–83% isolated yields). A previously synthesized iron complex of the general formula [Fe(η 5 -Cp)(CO)(PHOX)] + was found to be catalytically active in the title reaction as well, but needed three hours at room temperature to convert the starting materials to the products.
TURBULENT FLOW CALCULATIONS USING UNSTRUCTURED AND ADAPTIVE MESHES

A method of efficiently computing turbulent compressible flow over complex two dimensional configurations is presented. The method makes use of fully unstructured meshes throughout the entire flow-field, thus enabling the treatment of arbitrarily complex geometries and the use of adaptive meshing techniques throughout both viscous and inviscid regions of flow-field. Mesh generation is based on a locally mapped Delaunay technique in order to generate unstructured meshes with highly-stretched elements in the viscous regions. The flow equations are discretized using a finite element Navier-Stokes solver, and rapid convergence to steady-state is achieved using an unstructured multigrid algorithm. Turbulence modeling is performed using an inexpensive algebraic model, implemented for use on unstructured and adaptive meshes. Compressible turbulent flow solutions about multiple-element airfoil geometries are computed and compared with experimental data.
High-valent organometallic copper and palladium in catalysis

Advances in the chemistry of high-oxidation-state copper and palladium demonstrate their great potential as catalysts. Homogeneous copper and palladium catalysts are used to synthesize a broad range of organic molecules, including pharmaceuticals, commodity chemicals and polymers. Improvements in the activity, selectivity and scope of these catalysts have the potential to increase their usefulness and reduce the environmental impact of the chemical reactions. In this Review, Amanda Hickman and Melanie Sanford summarize recent advances by organometallic chemists working with a subset of catalysts that operate through an intermediate containing palladium in the +3 or +4 oxidation state or copper in the +3 oxidation state. Copper and palladium catalysts are critically important in numerous commercial chemical processes. Improvements in the activity, selectivity and scope of these catalysts could drastically reduce the environmental impact, and increase the sustainability, of chemical reactions. One rapidly developing strategy for achieving these goals is to use ‘high-valent’ organometallic copper and palladium intermediates in catalysis. Here we describe recent advances involving both the fundamental chemistry and the applications of these high-valent metal complexes in numerous synthetically useful catalytic transformations.
Second-harmonic generation in single-crystal films of an organic material.

Single-crystal films of 2-cyclooctylamino-5-nitropyridine have been prepared by the shear method, and the second-order susceptibility has been measured by second-harmonic generation. Polarization-dependent measurements in an a plate show that the maximum value of deff (~56 pm/V) is approximately 10 times larger than that of LiNbO3 and that the ratio d32/d33 is approximately −4 at a 1064-nm wavelength. This material has a phase-matching direction (type I only) for propagation parallel to the plane of the a plate. The results of these measurements are important for phase-matched second-harmonic generation in waveguides of this material.
Structured Data on the Web

Though search on the World-Wide Web has focused mostly on unstructured text, there is an increasing amount of structured data on the Web and growing interest in harnessing such data. Moreover, structured data is starting to play a greater role in many of the social movements enabled by the Web, such as citizen participation in government. I will describe several current projects at Google whose overall goal is enable people to create and share structured data on the Web and to leverage structured data in Web search.I will describe our system for crawling millions of ”deep-web” sites, that offer access to high-quality data through HTML forms and the WebTables and Octopus Systems that leverage structured data in HTML tables and lists on the surface web and enable users to piece together multiple datasets. Finally, I’ll describe Fusion Tables, a recently launched data-management service that lets users create and visualize structured and easily and emphasizes the ability to collaborate with other data owners.