cssi/SciSciGPT-SciSciNet huggingface dataset:
Geometric and renormalized entropy in conformal field theory

Abstract In statistical physics, useful notions of entropy are defined with respect to some coarse-graining procedure over a microscopic model. Here we consider some special problems that arise when the microscopic model is taken to be relativistic quantum field theory. These problems are associated with the existence of an infinite number of degrees of freedom per unit volume. Because of these the microscopic entropy can, and typically does, diverge for sharply localized states. However, the difference in the entropy between two such states is better behaved, and for most purposes it is the useful quantity to consider. In particular, a renormalized entropy can be defined as the entropy relative to the ground state. We make these remarks quantitative and precise in a simple model situation: the states of a conformal quantum field theory excited by a moving mirror. From this work, we attempt to draw some lessons concerning the “information problem” in black hole physics.
Molecular Dynamics and First-Principles Computations of Ga adlayers on GaN(0001)

Structural models for Ga adlayer(s) on GaN(0001) are investigated using both molecular dynamics and first-principles computations. An energetically favourable model is deduced that is consistent with observed low-energy electron diffraction data. The model contains regions of uniaxial contraction of the topmost Ga adlayer on the surface (rather than uniform biaxial contraction, as in previous models), multiple domains of which form a hexagonal arrangement on the surface. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Global Non-Iterative Design Optimization Using Monotonicity Analysis

The numerical techniques used in conventional optimization may not work for engineering design problems, which often present peculiar difficulties. Monotonicity analysis can identify a global optimum without any special computations and also prevent acceptance of false solutions generated by the numerical techniques. In the present paper, these advantages are demonstrated in a problem taken from the literature, for which diverse numerical solutions have been obtained. Monotonicity analysis identifies and proves the global optimum. Its application may require some algebraic rearrangement of the problem statement.
COVERING A SET OF POINTS WITH A MINIMUM NUMBER OF TURNS

Given a finite set of points in Euclidean space, we can ask what is the minimum number of times a piecewise-linear path must change direction in order to pass through all of them. We prove some new upper and lower bounds for the rectilinear version of this problem in which all motion is orthogonal to the coordinate axes. We also consider the more general case of arbitrary directions.
Multinational Firms, FDI Flows and Imperfect Capital Markets

This paper examines how costly financial contracting and weak investor protection influence the cross-border operational, financing, and investment decisions of firms. We develop a model in which product developers can play a useful role in monitoring the deployment of their technology abroad. The analysis demonstrates that when firms want to exploit technologies abroad, multinational firm (MNC) activity and foreign direct investment (FDI) flows arise endogenously when monitoring is nonverifiable and financial frictions exist. The mechanism generating MNC activity is not the risk of technological expropriation by local partners but the demands of external funders who require MNC participation to ensure value maximization by local entrepreneurs. The model demonstrates that weak investor protections limit the scale of MNC activity, increase the reliance on FDI flows, and alter the decision to deploy technology through FDI as opposed to arm's length technology transfers. Several distinctive predictions for the impact of weak investor protection on MNC activity and FDI flows are tested and confirmed using firm-level data.
Welfare Gains under Tradable CO2 Permits

lost environmentalists favor the reduction in CO2 emissions but oppose international trade in emISSIOns permits Although economic theory provides a strong case in favor of trade in permits) there is little ernpirical evidence of the size of potential benefits. "Ve estimate the benefits of this trade for OECD countries.
Synthesis of the first difunctional N-fluoro perfluoroalkylsulfonylimides, CF3SO2NFSO2(CF2)nSO2NFSO2CF3

Synthesis of difunctional N,N′-difluoro perfluoroalkylsulfonamides, CF3SO2NFSO2(CF2)nSO2NFSO2CF3, where n=4, 6 is reported. A related compound with an oxygen linkage CF3SO2NFSO2(CF2)2O(CF2)2SO2NFSO2CF3 has also been prepared. These reagents showed good activity for electrophilic fluorination.
Optimal Population Transfers in a Quantum System for Large Transfer Time

Transferring a quantum system to a final state with given populations is an important problem with applications to quantum chemistry and atomic physics. In this paper, we consider such transfers that minimize L2 the norm of the control. This problem is challenging, both analytically and numerically. With the exception of the simplest cases, there is no general understanding of the nature of optimal controls and trajectories. We find that, by examining the limit of large transfer times, we can uncover such general properties. In particular, for transfer times large with respect to the time scale of the free dynamics of the quantum system, the optimal control is a sum of terms, each being a Bohr frequency sinusoid modulated by a slow amplitude, i.e., a profile that changes considerably only on the scale of the transfer time. Moreover, we show that the optimal trajectory follows a ldquomeanrdquo evolution modulated by the fast free dynamics of the system. The calculation of the ldquomeanrdquo optimal trajectory and the slow control profiles is done via an ldquoaveragedrdquo two-point boundary value problem that we derive and which is much easier to solve than the one expressing the necessary conditions for optimality of the original optimal transfer problem.
A Unified Approach to Regularity Problems for the 3D Navier-Stokes and Euler Equations: the Use of Kolmogorov’s Dissipation Range

Motivated by Kolmogorov’s theory of turbulence we present a unified approach to the regularity problems for the 3D Navier-Stokes and Euler equations. We introduce a dissipation wavenumber $${\Lambda(t)}$$ that separates low modes where the Euler dynamics is predominant from the high modes where the viscous forces take over. Then using an indifferent to the viscosity technique we obtain a new regularity criterion which is weaker than every Ladyzhenskaya-Prodi-Serrin condition in the viscous case, and reduces to the Beale-Kato-Majda criterion in the inviscid case. In the viscous case we prove that Leray-Hopf solutions are regular provided $${\Lambda \in L^{5/2}}$$ , which improves our previous $${\Lambda \in L^\infty}$$ condition. We also show that $${\Lambda \in L^1}$$ for all Leray-Hopf solutions. Finally, we prove that Leray-Hopf solutions are regular when the time-averaged spatial intermittency is small, i.e., close to Kolmogorov’s regime.
Composite octet searches with jet substructure

Many new physics models with strongly interacting sectors predict a mass hierarchy between the lightest vector meson and the lightest pseudoscalar mesons. We examine the power of jet substructure tools to extend the 7 TeV LHC sensitivity to these new states for the case of QCD octet mesons, considering both two gluon and two b-jet decay modes for the pseudoscalar mesons. We develop both a simple dijet search using only the jet mass and a more sophisticated jet substructure analysis, both of which can discover the composite octets in a dijet-like signature. The reach depends on the mass hierarchy between the vector and pseudoscalar mesons. We find that for the pseudoscalar-to-vector meson mass ratio below approximately 0.2 the simple jet mass analysis provides the best discovery limit; for a ratio between 0.2 and the QCD-like value of 0.3, the sophisticated jet substructure analysis has the best discovery potential; for a ratio above approximately 0.3, the standard four-jet analysis is more suitable.
The dynamics of genetic draft in rapidly adapting populations.

The accumulation of beneficial mutations on competing genetic backgrounds in rapidly adapting populations has a striking impact on evolutionary dynamics. This effect, known as clonal interference, causes erratic fluctuations in the frequencies of observed mutations, randomizes the fixation times of successful mutations, and leaves distinct signatures on patterns of genetic variation. Here, we show how this form of “genetic draft” affects the forward-time dynamics of site frequencies in rapidly adapting asexual populations. We calculate the probability that mutations at individual sites shift in frequency over a characteristic timescale, extending Gillespie’s original model of draft to the case where many strongly selected beneficial mutations segregate simultaneously. We then derive the sojourn time of mutant alleles, the expected fixation time of successful mutants, and the site frequency spectrum of beneficial and neutral mutations. Finally, we show how this form of draft affects inferences in the McDonald–Kreitman test and how it relates to recent observations that some aspects of genetic diversity are described by the Bolthausen–Sznitman coalescent in the limit of very rapid adaptation.
Nonspinning black holes in alternative theories of gravity

We study two large classes of alternative theories, modifying the action through algebraic, quadratic curvature invariants coupled to scalar fields. We find one class that admits solutions that solve the vacuum Einstein equations and another that does not. In the latter, we find a deformation to the Schwarzschild metric that solves the modified field equations in the small-coupling approximation. We calculate the event horizon shift, the innermost stable circular orbit shift, and corrections to gravitational waves, mapping them to the parametrized post-Einsteinian framework.
Marine chemical ecology

This review covers the recent marine chemical ecology literature for benthic cyanobacteria, macroalgae, sponges, octocorals, molluscs, other benthic invertebrates, fish and seabirds.
Evidence of early Holocene glacial advances in southern South America from cosmogenic surface-exposure dating

Cosmogenic nuclide surface-exposure dating reveals that glaciers in southern South America (46°S) advanced at ca. 8.5 and 6.2 ka, likely as a result of a northward migration of the Southern Westerlies that caused an increase in precipitation and/or a decrease in temperature at this latitude. The older advance precedes the currently accepted initiation of Holocene glacial activity in southern South America by ~3000 yr. Both of these advances are temporally synchronous with Holocene climate oscillations that occurred in Greenland and the rest of the world. If there are causal links between these events, then rapid climate changes appear to be either externally forced (e.g., solar variability) or are rapidly propagated around the globe (e.g., atmospheric processes).
Magnetic domination of recollimation boundary layers in relativistic jets

We study the collimation of relativistic magnetohydrodynamic jets by the pressure of an ambient medium, in the limit where the jet interior loses causal contact with its surroundings. This follows up a hydrodynamic study in a previous paper, adding the effects of a toroidal magnetic field threading the jet. As the ultrarelativistic jet encounters an ambient medium with a pressure profile with a radial scaling of p ∝ r−η where 2 < η < 4, it loses causal contact with its surroundings and forms a boundary layer with a large pressure gradient. By constructing self-similar solutions to the fluid equations within this boundary layer, we examine the structure of this layer as a function of the external pressure profile. We show that the boundary layer always becomes magnetically dominated far from the source, and that in the magnetic limit, physical self-similar solutions are admitted in which the total pressure within the layer decreases linearly with distance from the contact discontinuity inwards. These solutions suggest a ‘hollow-cone’ behaviour of the jet, with the boundary-layer thickness prescribed by the value of η. In contrast to the hydrodynamical case, however, the boundary layer contains an asymptotically vanishing fraction of the jet energy flux.
Classification of Doubly Excited States of Two-Electron Atoms

Doubly excited states of atoms were first detected and discussed in the 30’s,1 but their systematic study dates from the UV photoabsorption spectroscopy of helium in the early 60’s by Madden and Codling.2–3 In the spectra, two series of resonances, one intense and the other fainter and sharper, were observed. These resonances were attributed to the temporary formation of discrete states of the doubly excited intermediate, He , which eventually autoionize into He+ (N=1)+e- . It took the great insight of Fano to recognize the important implication of the observed strong contrast in the strength of the two series. Cooper, Fano and Prats argued that these doubly excited states cannot be adequately described by the independent electron model. The designation of states such as 2snp and 2pns P° would imply that the two series have nearly identical strength. They pointed out that the experimental data indicated that the two series are better approximated as 2snp+2pns and 2snp-2pns, and labelled as the ‘+’ and the ‘-’ series, respectively.
Half-Duplex Active Eavesdropping in Fast-Fading Channels: A Block-Markov Wyner Secrecy Encoding Scheme

In this paper, we study the problem of half-duplex active eavesdropping in fast-fading channels. The active eavesdropper is a more powerful adversary than the classical eavesdropper. It can choose between two functional modes: eavesdropping the transmission between the legitimate parties (Ex mode), and jamming it (Jx mode)-the active eavesdropper cannot function in full duplex mode. We consider a conservative scenario, when the active eavesdropper can choose its strategy based on the legitimate transmitter-receiver pair's strategy, and thus, the transmitter and legitimate receiver have to plan for the worst. We show that conventional physical-layer secrecy approaches perform poorly (if at all), and we introduce a novel encoding scheme, based on very limited and unsecured feedback-the Block-Markov Wyner encoding scheme-which outperforms any schemes currently available.
Formulas for ASEP with Two-Sided Bernoulli Initial Condition

For the asymmetric simple exclusion process ηt on the integer lattice with two- sided Bernoulli initial condition, we derive exact formulas for the following quantities: (1) P(ηt (x) = 1), the probability that site x is occupied at time t; (2) the correlation function P(ηt (x) = 1 ,η 0(0) = 1); (3) the distribution function for Qt , the total flux across 0 at time t, and its exponential generating function.
Andean growth and the deceleration of South American subduction: Time evolution of a coupled orogen-subduction system

article i nfo Present-day orography at the Andean margin is a result of isostasy, tectonic accretion, and erosional processes. The resulting excess mass of the Andes gives rise to frictional stresses on the seismogenic plate interface that resist the sinking of the subducting slab into the upper mantle. Thus, subduction rates should be sensitive to the time-dependent dynamics of a back-arc orogen, as well as erosional or accretional processes that affect orogen growth. Here we develop a two-dimensional coupled orogen-slab model that allows for the prediction of orogen size and plate motion in response to both tectonic and erosional forcing. We find that the frictional force exerted by the orogen on the subducting slab grows quadratically with orogen width and that the frictional resistance typically balances 10-50% of the slab pull force. The time evolution of the coupled orogen-subduction zone system is largely controlled by the rate of orogen growth, which is controlled by the rate of convergence and the erosivity of the climate state. In the case of the Andean margin, our models show that Miocene aridification leads to reduced erosion, increased orogen growth, greater frictional resistance to subduction, and, ultimately, to a ~50% reduction in the convergence rate between the Nazca and South American plates.
Vertical extrapolation of Mars magnetic potentials

[1] Mars Global Surveyor (MGS) measured the most strongly magnetized crust in the heavily cratered southern hemisphere of Mars. Our analysis concentrates on the magnetic lineations or patterns centered near latitude 40� S, longitude 180� W, with a range of values ±40� , using a rotated Cartesian coordinate system. We downward continued the magnetic field measured at � 400 km elevation and very closely match the corresponding component measured during the aerobraking phase at altitudes extending down to � 100 km. Using the vertical component of the magnetic field alone, we construct a unique scalar potential and independently obtain from the derivatives of this scalar potential the x and y components of the field. These derived components agree very well with the observed horizontal components. This demonstrates the validity and utility of the method and the Cartesian approximation, and also it confirms the consistency of the MGS magnetic data set. A model constructed with just 8 vertical dipoles accounts for 80% of the variance of the scalar potential at 400 km over the region analyzed, but 14 dipoles can account for only 64% of the variance at 100 km. We also construct the vector potential, the curl of which generates the three components of the magnetic field. This more complicated description may contain more physical meaning than the scalar potential. The vector potential shows abrupt changes in direction over the analyzed region, suggesting either different stages of magnetization or local demagnetization. INDEX TERMS: 5440 Planetology: Solid Surface Planets: Magnetic fields and magnetism; 5420 Planetology: Solid Surface Planets: Impact phenomena (includes cratering); 6225 Planetology: Solar System Objects: Mars; KEYWORDS: magnetic, Mars, models
Intrauterine lidocaine infusion for pain management during outpatient transcervical tubal sterilization: a randomized controlled trial.

Abstract Background The study was conducted to examine the effects of a 4% intrauterine lidocaine infusion on patient-perceived pain during transcervical sterilization. Study Design This was a randomized, double-blind, placebo-controlled trial. Subjects received standard premedication with 800 mg ibuprofen, 2 mg lorazepam, a 10-mL 1% lidocaine paracervical block and transcervical instillation of 5 mL of either 4% lidocaine or saline 3 min prior to insertion of the hysteroscope. Subjects completed a series of 100-mm visual analog scales to measure their perceived pain at set time points during and after the procedure. Serum lidocaine levels were obtained in a subset of subjects. Results Pain scores at all evaluation points did not significantly differ between groups (lidocaine n=29, saline n=29). Mean lidocaine levels did not differ between groups, and no subject demonstrated symptoms of lidocaine toxicity. The highest serum lidocaine level (4022 ng/mL) occurred 20 min after infusion in a lidocaine-treated subject. Conclusion Intrauterine lidocaine prior to outpatient transcervical sterilization does not decrease pain.
Learning to paraphrase: an unsupervised approach using multiple-sequence alignment

We address the text-to-text generation problem of sentence-level paraphrasing --- a phenomenon distinct from and more difficult than word- or phrase-level paraphrasing. Our approach applies multiple-sequence alignment to sentences gathered from unannotated comparable corpora: it learns a set of paraphrasing patterns represented by word lattice pairs and automatically determines how to apply these patterns to rewrite new sentences. The results of our evaluation experiments show that the system derives accurate paraphrases, outperforming baseline systems.
The Oxidation of Primary Alcohols to Methyl Esters and Diols to Lactones Using Trichloroisocyanuric Acid

Primary alcohols and diols are easily oxidized to methyl esters by a solution of trichloroisocyanuric acid with methyl alcohol in dichloromethane. In addition, α,ω-diols are also readily oxidized into lactones by refluxing with trichloroisocyanuric acid and pyridine in dichloromethane.
Variability of Quasars at 10 Microns

Twenty-five low-redshift quasars have been monitored for several decades at five near- and midinfrared wavelengths to detect rapid variations that would indicate that a nonthermal component was present in the "10 μm bump." Such variability has apparently been detected in several radio-loud quasars and in the radio-quiet quasar PG 1535+547. In addition, the structure function of PG 1226+023 shows that an apparently periodic component is present in its near-infrared emission.
Gain characteristics of InGaN/GaN quantum well diode lasers

We report on gain spectra of InGaN/AlGaN MQW SCH diode lasers, grown and fabricated on 6H-SiC substrates. The active medium was composed of 8 QWs with a nominal indium composition of x=0.1. The devices were index guided ridge waveguide structures with a typical cavity length of 500 /spl mu/m and a mesa width of 5 /spl mu/m. The gain studies are based on the analysis of the spontaneous emission spectra of the devices, collected normal to the resonator axis as a function of injection, while making use of fundamental connections between spontaneous emission, stimulated emission, and absorption. An example of the gain/absorption spectra in the InGaN MQW diode laser at room temperature is shown.
Gender in Job Negotiations: A Two-Level Game

We propose taking a two-level-game perspective on gender in job negotiations. At Level One, candidates negotiate with employers. At Level Two, candidates negotiate with household members. In order to illuminate the interplay between these two levels, we review research from two separate bodies of literature. Research in psychology and organizational behavior on candidate–employer negotiations sheds light on the effects of gender on Level One negotiations. Research from economics and sociology on intrahousehold bargaining elucidates how negotiations over the allocation of domestic labor at Level Two influence labor force participation at Level One. In conclusion, we integrate practical implications from these two bodies of literature to propose a set of prescriptive suggestions for candidates to approach job negotiations as a two-level game and to minimize the disadvantageous effects of gender on job negotiation outcomes.
Core extensions for non-balanced TU-games

A family of core extensions for cooperative TU-games is introduced. These solution concepts are non-empty when applied to non-balanced games yet coincide with the core whenever the core is non-empty. The extensions suggest how an exogenous regulator can sustain a stable and efficient outcome, financing a subsidy via individual taxes. Economic and geometric properties of the solution concepts are studied. When taxes are proportional, the proportional prenucleolus is proposed as a single-valued selection device. An application of these concepts to the decentralization of a public goods economy is discussed.
Rough solutions of the Einstein constraints on closed manifolds without near-CMC conditions

We consider the conformal decomposition of Einstein’s constraint equations introduced by Lichnerowicz and York, on a closed manifold. We establish existence of non-CMC weak solutions using a combination of priori estimates for the individual Hamiltonian and momentum constraints, barrier constructions and fixed-point techniques for the Hamiltonian constraint, Riesz-Schauder theory for the momentum constraint, together with a topological fixed-point argument for the coupled system. Although we present general existence results for non-CMC weak solutions when the rescaled background metric is in any of the three Yamabe classes, an important new feature of the results we present for the positive Yamabe class is the absence of the near-CMC assumption, if the freely specifiable part of the data given by the traceless-transverse part of the rescaled extrinsic curvature and the matter fields are sufficiently small, and if the energy density of matter is not identically zero. In this case, the mean extrinsic curvature can be taken to be an arbitrary smooth function without restrictions on the size of its spatial derivatives, so that it can be arbitrarily far from constant, giving what is apparently the first existence results for non-CMC solutions without the near-CMC assumption. Using a coupled topological fixed-point argument that avoids near-CMC conditions, we establish existence of coupled non-CMC weak solutions with (positive) conformal factor ϕ ∈ W s,p , where p ∈ (1,∞) and s(p) ∈ (1 + 3/p,∞). In the CMC case, the regularity can be reduced to p ∈ (1,∞) and s(p) ∈ (3/p, ∞) ∩ [1,∞). In the case of s = 2, we reproduce the CMC existence results of Choquet-Bruhat [10], and in the case p = 2, we reproduce the CMC existence results of Maxwell [33], but with a proof that goes through the same analysis framework that we use to obtain the non-CMC results. The non-CMC results on closed manifolds here extend the 1996 non-CMC result of Isenberg and Moncrief in three ways: (1) the near-CMC assumption is removed in the case of the positive Yamabe class; (2) regularity is extended down to the maximum allowed by the background metric and the matter; and (3) the result holds for all three Yamabe classes. This last extension was also accomplished recently by Allen, Clausen and Isenberg, although their result is restricted to the near-CMC case and to smoother background metrics and data.
Teacher opinions on performance incentives : evidence from the Kyrgyz Republic

This paper uses data from a post-hoc evaluation of a performance-based teacher incentive program in the Kyrgyz Republic to examine the opinions of teachers receiving different pay bonuses based on their performance as assessed by external evaluators. Overall, teacher opinions of the program were favorable, although teachers who received lower performance ratings held less favorable opinions about the motivational aspects of the program. Despite this, lower-rated teachers were more likely to report that they used what they learned to evaluate their own teaching, as compared with more highly rated teachers, and were more likely to take professional development courses in the years following the program's implementation.
Low-cost and small footprint solution for testing low-voltage differential signal video displays

In recent years, liquid crystal displays (LCD) have almost completely replaced older technologies such as cathode ray tube displays in many industrial, commercial, aerospace, and military applications due to their increased efficiency, decreased weight, and smaller size. Likewise, the technology used to transmit video signals to LCD displays has evolved from analog standards such as the National Television Standards Council's (NTSC) RS-170 standard and the Phase Alternating Line (PAL) standard to higher speed digital standards such as the Digital Visual Interface standard, High-Definition Multimedia Interface standard, and low-voltage differential signaling (LVDS) standard. This evolution of video standards has created a need for the test environments and test generation devices used to test video displays to mature as well.
Global QCD Analysis and Hadron Collider Physics

The role of global QCD analysis of parton distribution functions (PDFs) in collider physics at the Tevatron and LHC is surveyed. Current status of PDF analyses are reviewed, emphasizing the uncertainties and the open issues. The stability of NLO QCD global analysis and its prediction on "standard candle" W/Z cross sections at hadron colliders are discussed. The importance of the precise measurement of various W/Z cross sections at the Tevatron in advancing our knowledge of PDFs, hence in enhancing the capabilities of making significant progress in W mass and top quark parameter measurements, as well as the discovery potentials of Higgs and New Physics at the Tevatron and LHC, is emphasized.
A hybrid pulse shape discrimination technique with enhanced performance at neutron energies below 500 keV

Abstract A hybrid pulse shape discrimination (PSD) method is presented that combines a charge-integration PSD method with a reference-pulses PSD method. The reference-pulses PSD method uses detailed knowledge of the average, energy-dependent detector response to radiation. To obtain the reference-pulses, a large number of neutron and gamma-ray pulses was averaged in several pulse height regions. The reference neutron and gamma-ray pulses were then used in the new PSD method for the classification of a large number of measured pulses. The reference-pulses PSD method was applied below 70 keVee, whereas the standard charge-integration PSD method was used above 70 keVee. This new hybrid PSD method proves to be more accurate than the standard charge-integration PSD method for classification of neutrons and gamma rays. Specifically, the improvement is approximately 30% for neutrons in the smallest pulse height bin considered, which was between 20 and 30 keVee (corresponding to approximately 150 and 225 keV neutron energy deposited, respectively). For this pulse height bin, approximately 72% of the neutrons were correctly classified by the hybrid PSD method. The average number of correctly classified neutrons is approximately 88% for the hybrid PSD method between 20 and 100 keVee (corresponding to approximately 150 and 670 keV neutron energy deposited, respectively) as opposed to 83% for the charge-integration PSD method.
Fuzzy logic based collision avoidance for a mobile robot

Navigation and collision avoidance are major areas of research in mobile robotics that involve varying degrees of uncertainty. In general, the problem consists of achieving sensor based motion control of a mobile robot among obstacles in structured and/or unstructured environments with collision-free motion as the priority. A fuzzy logic based intelligent control strategy has been developed here to computationally implement the approximate reasoning necessary for handling the uncertainty inherent in the collision avoidance problem. The fuzzy controller was tested on a mobile robot system in an indoor environment and found to perform satisfactorily despite having crude sensors and minimal sensory feedback.
GROUP INVARIANT SOLUTIONS WITHOUT TRANSVERSALITY

We present a generalization of Lie's method for finding the group invariant solutions to a system of partial differential equations. Our generalization relaxes the standard transversality assumption and encompasses the common situation where the reduced differential equations for the group invariant solutions involve both fewer dependent and independent variables. The theoretical basis for our method is provided by a general existence theorem for the invariant sections, both local and global, of a bundle on which a finite dimensional Lie group acts. A simple and natural extension of our characterization of invariant sections leads to an intrinsic characterization of the reduced equations for the group invariant solutions for a system of differential equations. The char- acterization of both the invariant sections and the reduced equations are summarized schematically by the kinematic and dynamic reduction diagrams and are illustrated by a number of examples from fluid mechanics, harmonic maps, and general relativity. This work also provides the theoretical foundations for a further detailed study of the reduced equations for group invariant solutions.
Urban Poverty and Juvenile Crime: Evidence from a Randomized Housing-Mobility Experiment

This paper uses data from a randomized housing-mobility experiment to study the effects of relocating families from high- to low-poverty neighborhoods on juvenile crime. Outcome measures come from juvenile arrest records taken from government administrative data. Our e ndings seem to suggest that providing families with the opportunity to move to lower-poverty neighborhoods reduces violent criminal behavior by teens.
THE RETURN ON INVESTMENT FROM PROPORTIONAL PORTFOLIO STRATEGIES

Dynamic asset allocation strategies that are continuously rebalanced so as to always keep a xed constant proportion of wealth invested in the various assets at each point in time play a fundamental role in the theory of optimal portfolio strategies. In this paper we study the rate of return on investment, dened here as the net gain in wealth divided by the cumulative investment, for such investment strategies in continuous time. Among other results, we prove that the limiting distribution of this measure of return is a gamma distribution. This limit theorem allows for comparisons of dierent strategies. For example, the mean return on investment is maximized by the same strategy that maximizes logarithmic utility, which is also known to maximize the exponential rate at which wealth grows. The return from this policy turns out to have other stochastic dominance properties as well. We also study the return on the risky investment alone, dened here as the present value of the gain from investment divided by the present value of the cumulative investment in the risky asset needed to achieve the gain. We show that for the log-optimal, or optimal growth policy, this return tends to an exponential distribution. We compare the return from the optimal growth policy with the return from a policy that invests a constant amount in the risky stock. We show that for the case of a single risky investment, the constant investor’s expected return is twice that of the optimal growth policy. This dierence can be considered the cost for insuring that the proportional investor does not go bankrupt.
Segmentation in episodic tremor and slip all along Cascadia

The recent discovery of episodic tremor and slip (ETS) in subduction zones is based on slow slip episodes visible in global positioning system observations correlated with nonvolcanic tremor signals on seismometers. ETS occurs just inboard from a region capable of great megathrust earthquakes; however, whether there is any communication between these two processes remains unknown. In this study we use new single-station methods to compile an ETS catalog for the entire Cascadia subduction zone, offshore western North America, and compare the patterns with a variety of along-strike trends for the subducting and overriding plates. Correlated ground vibrations and strain observations are found all along the subduction zone, demonstrating that ETS is an inherent part of the subduction process. There are three broad (300–500 km), coherent zones with different recurrence intervals (14 ± 2, 19 ± 4, 10 ± 2 months), where the interval duration is inversely proportional to upper plate topography and the spatial extent correlates with geologic terranes. These zones are further divided into segments of ETS that occur at times typically offset from each other. The seven largest (100– 200 km) segments appear to be located immediately landward from forearc basins interpreted as manifestations of megathrust asperities, implying that there is a spatial link between ETS and earthquake behavior. It is not yet clear if any temporal link exists, but the regional time between ETS episodes could be controlled by strength variations due to composition of geologic terranes.
Fate of the Born–Infeld Solution in String Theory

We argue that the Born–Infeld solution on the D9-brane is unstable under inclusion of derivative corrections to Born–Infeld theory coming from string theory. More specifically, we find no electrostatic solutions to the first-order corrected Born–Infeld theory on the D9-brane which give a finite value for the Lagrangian.
Analysis and implementation of hybrid switching

The switching scheme of a point-to-point network determines how packets flow through each node, and is a primary element in determining the network's performance. In this paper, we present and evaluate a new switching scheme called hybrid switching. Hybrid switching dynamically combines both virtual cut-through and wormhole switching to provide higher achievable throughput than wormhole alone, while significantly reducing the buffer space required at intermediate nodes when compared to virtual cut-through. This scheme is motivated by a comparison of virtual cut-through and wormhole switching through cycle-level simulations, and then evaluated using the same methods. To show the feasibility of hybrid switching, as well as to provide a common base for simulating and implementing a variety of routing and switching schemes, we have designed SPIDER, a communication adapter built around a custom ASIC called the programmable routing controller (PRC).
Approximate Privacy: Foundations and Quantification

The proliferation of online sensitive data about individuals and organizations makes concern about the privacy of these data a top priority. There have been many formulations of privacy and, unfortunately, many negative results about the feasibility of maintaining privacy of sensitive data in realistic networked environments. We formulate communication-complexity-based definitions, both worst case and average case, of a problem’s privacy-approximation ratio. We use our definitions to investigate the extent to which approximate privacy is achievable in a number of standard problems: the 2nd-price Vickrey auction, Yao’s millionaires problem, the public-good problem, and the set-theoretic disjointness and intersection problems.For both the 2nd-price Vickrey auction and the millionaires problem, we show that not only is perfect privacy impossible or infeasibly costly to achieve, but even close approximations of perfect privacy suffer from the same lower bounds. By contrast, if the inputs are drawn uniformly at random from l 0,…, 2k-1r, then, for both problems, simple and natural communication protocols have privacy-approximation ratios that are linear in k (i.e., logarithmic in the size of the input space). We also demonstrate tradeoffs between privacy and communication in a family of auction protocols.We show that the privacy-approximation ratio provided by any protocol for the disjointness and intersection problems is necessarily exponential (in k). We also use these ratios to argue that one protocol for each of these problems is significantly fairer than the others we consider (in the sense of relative effects on the privacy of the different players).
Small molecule control of bacterial biofilms

Bacterial biofilms are defined as a surface attached community of bacteria embedded in a matrix of extracellular polymeric substances that they have produced. When in the biofilm state, bacteria are more resistant to antibiotics and the host immune response than are their planktonic counterparts. Biofilms are increasingly recognized as being significant in human disease, accounting for 80% of bacterial infections in the body and diseases associated with bacterial biofilms include: lung infections of cystic fibrosis patients, colitis, urethritis, conjunctivitis, otitis, endocarditis and periodontitis. Additionally, biofilm infections of indwelling medical devices are of particular concern, as once the device is colonized infection is virtually impossible to eradicate. Given the prominence of biofilms in infectious diseases, there has been an increased effort toward the development of small molecules that will modulate bacterial biofilm development and maintenance. In this review, we highlight the development of small molecules that inhibit and/or disperse bacterial biofilms through non-microbicidal mechanisms. The review discuses the numerous approaches that have been applied to the discovery of lead small molecules that mediate biofilm development. These approaches are grouped into: (1) the identification and development of small molecules that target one of the bacterial signaling pathways involved in biofilm regulation, (2) chemical library screening for compounds with anti-biofilm activity, and (3) the identification of natural products that possess anti-biofilm activity, and the chemical manipulation of these natural products to obtain analogues with increased activity.
Inorganic Fibers—A Literature Review

A review of inorganic fibers other than asbestos, glass, and carbon fibers and optical and hollow fibers. Special emphasis is placed on high-performance fibers. The manufacture, structure, properties, and uses of the selected fibers are discussed.
Predicting Counterproductive Work Behavior from Guilt Proneness

We investigated the relationship between guilt proneness and counterproductive work behavior (CWB) using a diverse sample of employed adults working in a variety of different industries at various levels in their organizations. CWB refers to behaviors that harm or are intended to harm organizations or people in organizations. Guilt proneness is a personality trait characterized by a predisposition to experience negative feelings about personal wrongdoing. CWB was engaged in less frequently by individuals high in guilt proneness compared to those low in guilt proneness, controlling for other known correlates of CWB. CWB was also predicted by gender, age, intention to turnover, interpersonal conflict at work, and negative affect at work. Given the detrimental impact of CWB on people and organizations, it may be wise for employers to consider guilt proneness when making hiring decisions.
Rimage: Safeguarding Intellectual Property in China

Rimage was an on-demand digital publishing company based in Minnesota, USA. Since 1992, Rimage had been internationalizing its business in Europe, Scandinavia, Africa, Middle East, and Russia. By 2004, its products had penetrated Japanese market. Encouraged by its success in Japan, Rimage considered entry into China. The initial market assessment identified opportunities in China, but also risk. As a technology driven company, Rimage's main management dilemma was how to set up operations in China while keeping its intellectual property secure. Manny Almeida, Rimage's Chief Operating Officer, carefully pondered the company's entry into China. Did the opportunities outweigh the risks? This decisional case is based on field research. There is an epilogue detailing the steps Rimage took to protect its intellectual property in China. The case aims to provide insight for international business in safeguarding intellectual property rights.
Javaniside, a novel DNA cleavage agent from Alangium javanicum having an unusual oxindole skeleton

Bioassay-guided fractionation of an extract prepared from Alangium javanicum using an assay to monitor Cu2+-dependent DNA strand scission led to the isolation of javaniside, a new type of oxindole glycoside.
A New Approach to Estimating the Probability of Winning the Presidency

As the 2000 election so vividly showed, it is Electoral College standings rather than national popular votes that determine who becomes President. But current pre-election polls focus almost exclusively on the popular vote. Here we present a method by which pollsters can achieve both point estimates and margins of error for a presidential candidate's electoral-vote total. We use data from both the 2000 and 1988 elections to illustrate the approach. Moreover, we indicate that the sample sizes needed for reliable inferences are similar to those now used in popular-vote polling.
Causes and Consequences of Food Retailing Innovation in Developing Countries: Supermarkets in Vietnam

I examine the modernization of food retailing in developing economies, focusing on the early stages of retail modernization in Vietnam. This modernization represents innovation that is sought by the host country and that depends on knowledge transfer. Retail modernization has profound effects on the host country and its food system. Innovation at the consumption (retail) end of the food supply chain warrants attention similar to that devoted to knowledge transfer at the production (farming) end of the chain.
FISCAL STABILIZATION WITH PARTIAL EXCHANGE RATE PASS-THROUGH

This paper examines the role of fiscal stabilization policy in a two-country framework that allows for a general degree of exchange rate pass-through. I derive analytical solutions for optimal monetary and fiscal policy which are shown to depend on the degree of passthrough. In the case of partial pass-through, an optimizing policy maker uses counter-cyclical fiscal stabilization in addition to monetary stabilization. However, in the extreme cases of complete or zero pass-through, the fiscal stabilization instrument is not employed. There is also no additional gain from the fiscal instrument in the case of coordination between the two countries. These results are due to the specific way the optimal fiscal policy rule affects marginal costs: Rather than being a substitute for monetary policy, fiscal policy complements it by increasing the correlation of the marginal cost terms within and across countries. This in turn makes monetary policy more effective at stabilizing them.
Time Preference and the Distributions of Wealth and Income

This paper presents a dynamic competitive equilibrium model in which heterogeneity in time preferences alone can generate the observed patterns of wealth and income inequality in the United States. This model generalizes the standard deterministic neoclassical growth model by introducing (i) a direct preference for wealth by the consumers and (ii) human capital formation. The first feature prevents the wealth distribution from collapsing into a degenerate distribution. The second feature generates a strong positive correlation between earnings and wealth across agents. A calibrated version of this model is able to replicate the wealth and income distributions of the United States.
Thermal Homogenization in Spherical Reservoir by Electrohydrodynamic Conduction Phenomenon

Effect of electric conduction phenomenon on the mixing mechanism is studied numerically to thermally homogenize a dielectric liquid with an initial nonuniform temperature distribution. The fluid is stored in a spherical reservoir, and the electrodes are embedded on the reservoir surface such that the resultant local electric body forces mix the fiuid. The electric field and electric body force distributions along with the resultant velocity field at the final steady-state condition are presented. The mixing mechanism is illustrated by the time evolution of temperature distribution inside the reservoir. The effects of primary dimensionless numbers on the mixing time are studied.