cssi/SciSciGPT-SciSciNet huggingface dataset:
Experimental flowfield visualization of a high alpha wing at Mach 1.62

Experimental oil-flow and tuft patterns and vapor-screen flow-visualization data were obtained on a cambered wing model at Mach = 1.62 for an angle-of attack range of 0-14 deg. These data were used as flow diagnostic tools along with surface-pressure and force data and full-potential theory calculations. A large separation bubble was found on the lower wing surface at low angle of attack. The high-angle-of-attack flowfield was characterized by a large attached-flow leading-edge expansion followed by a crossflow shock. At alpha = 14 deg the crossflow shock apparently induced discrete regions of streamwise separated flow, which were clearly indicated in the vapor-screen and oil-flow photographs.
CCF: Collaborative Computing Frameworks

CCF (Collaborative Computing Frameworks) is a suite of software systems, communications protocols, and tools that enable collaborative, computer-based cooperative work. CCF constructs a virtual work environment on multiple computer systems connected over the Internet, to form a Collaboratory. In this setting, participants interact with each other, simultaneously access and operate computer applications, refer to global data repositories or archives, collectively create and manipulate documents or other artifacts, perform computational transformations, and conduct a number of other activities via telepresence. Research issues addressed in this project include problem solving environments and methodologies for laboratory and instrument-based scientific disciplines, and computer science issues in heterogeneous distributed systems. New approaches are being investigated and developed for fast multiway communication, robust geographically distributed data management methodologies, high-performance computational transforms inlined within collaboration sessions, and related auxiliary issues such as active documents, security, archival storage, and experiment management and control. In this paper, we discuss the design philosophy and systems rationale behind CCF, describe the major subsystems of the collaborative computing environment, and discuss the salient features of the system.
Price leadership and firm size asymmetry: an experimental analysis

We use laboratory experiments to examine the effect of firm size asymmetry on the emergence of price leadership in a price-setting duopoly with capacity constraints. Independent of the level of size asymmetry, the unique subgame perfect equilibrium of our timing game predicts that the large firm is the price leader. Experimental data show that price leadership by the large firm is frequent, but simultaneous moves are also often observed. Profit outcomes in the previous period affect the subjects’ decisions to announce or wait in a way that hampers convergence to the equilibrium. Furthermore, while both small and large firms display a strong tendency to wait to announce their price when firm size asymmetry is low, they often set prices early when size asymmetry is high. Prices are higher when price setting is sequential rather than simultaneous and when firm size asymmetry is high. Hence, price leadership by either type of firm has an anti-competitive effect that is more pronounced when the size difference between firms is large.
Particle Dynamics Simulations in Inlet Separator with an Experimentally Based Bounce Model

This article presents a probabilistic simulation methodology for the particle dynamics through a helicopter engine's inlet separator with an experimentall y based particle bounce model. The flowfield is determined from the numerical solution of the compressible Navier-Stokes equations with a two-equation turbulence model. The probabilistic simulations of the particle dynamics take into consideration the experimentally measured variance in the particle bounce conditions after surface interactions. Results are presented for the particle trajectories through the inlet and for the separator effectiveness over a range of sand particle sizes, and also for C-spec. sand.
Hydrogen-Free Alkene Reduction in Continuous Flow

The first continuous hydrogenation that requires neither H2 nor metal catalysis generates diimide by a novel reagent combination. The simple flow reactor employed minimizes residence time by enabling safe operation at elevated temperature.
What explains skill upgrading in less developed countries

Abstract Although many developing countries have experienced growing income inequality and an increase in the relative demand for skilled workers during the 1980s, the sources of this trend remain a puzzle. This paper examines whether investment and adoption of skill-biased technology have contributed to within-industry skill upgrading in Chilean plants. Using semiparametric and parametric approaches, I investigate whether plant-level measures of capital and investment, the use of imported materials, foreign technical assistance, and patented technology affect the relative demand for skilled workers. I find that some of the increased relative demand for skilled workers can be attributed to capital deepening. However, the relationship between skill upgrading and the three technology measures disappears once I control for unobserved plant characteristics. These results suggest that plant adoption of foreign technology is not associated with plant skill upgrading.
Synthesis of block, graft and star polymers from inorganic macroinitiators

Recent advances in the synthesis of block, graft and star polymers containing inorganic macromolecular species are described. Anionic copolymerization techniques were used in the formation of diblock copolymers of poly(styreneblock-methylphenylsilylene) and poly(isopreneblock-methylphenylsilylene) by the ring-opening polymerization of 1,2,3,4-tetramethyl-1,2,3,4tetraphenylcyclotetrasilane initiated by living anionic polystyrene and isoprene respectively. Hydrosilation of an attachable initiator onto telechelic vinyl- or hydrosilyl-terminal or -pendant poly(dimethylsiloxane) (PDMS) yielded a PDMS macroinitiator. This macroinitiator was used in atom transfer radical polymerization (ATRP) of styrene and isobornyl acrylate to produce ABA triblock copolymers. As a model for graft copolymers from a polyphosphazene backbone, chemical transformation of hexachlorocyclotriphosphazene resulted in hexafunctional molecules containing either benzyl bromide or bromopropionyl moieties. The initiator 1,1,3,3,5,5-hexakis[4-(2bromopropionyloxymethyl)phenoxy]cyclotriphosphazene was used in the ATRP of styrene to yield a polymer with a narrow, monomodal molecular weight distribution. Chain extension of this star polymer with isobornyl acrylate is also described. # 1998 John Wiley & Sons, Ltd.
Insecurity of Property Rights and Matching in the Tenancy Market

This paper analyzes the functioning of land rental markets in the Dominican Republic using a new data set collected specifically to characterize the entire market. We analyze the choice of the landlords and the tenants in the search for the optimal partner. We show how insecure property rights leads to segmentation in the tenancy markets along socio-economic group and hence severely limits access to land for the rural poor.
Optical flares from the tidal disruption of stars by massive black holes

A star that wanders too close to a massive black hole (BH) is shredded by the BH’s tidal gravity. Stellar gas falls back to the BH at a rate initially exceeding the Eddington rate, releasing a flare of energy. In anticipation of upcoming transient surveys, we predict the light curves and spectra of tidal flares as a function of time, highlighting the unique signatures of tidal flares at optical and near-infrared wavelengths. A reasonable fraction of the gas initially bound to the BH is likely blown away when the fallback rate is super-Eddington at early times. This outflow produces an optical luminosity comparable to that of a supernova; such events have durations of � 10 days and may have been missed in supernova searches that exclude the nuclear regions of galaxies. When the fallback rate subsides below Eddington, the gas accretes onto the BH via a thin disk whose emission peaks in the UV to soft X-rays. Some of this emission is reprocessed by the unbound stellar debris, producing a spectrum of very broad emission lines (with no corresponding narrow forbidden lines). These lines are the strongest for BHs with MBH � 10 5 10 6 M⊙ and thus optical surveys are particularly sensitive to the lowest mass BHs in galactic nuclei. Calibrating our models to ROSAT and GALEX observations, we predict detection rates for Pan-STARRS, PTF, and LSST and highlight some of the observational challenges associated with studying tidal disruption events in the optical. Upcoming surveys such as Pan-STARRS should detect at least tens of events per year, and may detect many more if current models of outflows during super-Eddington accretion are reasonably accurate. These surveys will significantly improve our knowledge of stellar dynamics in galactic nuclei, the physics of super-Eddington accretion, the demography of intermediate mass BHs, and the role of tidal disruption in the growth of massive BHs.
Scalable Kernel Methods via Doubly Stochastic Gradients

The general perception is that kernel methods are not scalable, so neural nets become the choice for large-scale nonlinear learning problems. Have we tried hard enough for kernel methods? In this paper, we propose an approach that scales up kernel methods using a novel concept called "doubly stochastic functional gradients". Based on the fact that many kernel methods can be expressed as convex optimization problems, our approach solves the optimization problems by making two unbiased stochastic approximations to the functional gradient—one using random training points and another using random features associated with the kernel—and performing descent steps with this noisy functional gradient. Our algorithm is simple, need no commit to a preset number of random features, and allows the flexibility of the function class to grow as we see more incoming data in the streaming setting. We demonstrate that a function learned by this procedure after t iterations converges to the optimal function in the reproducing kernel Hilbert space in rate O(1/t), and achieves a generalization bound of O(1/√t). Our approach can readily scale kernel methods up to the regimes which are dominated by neural nets. We show competitive performances of our approach as compared to neural nets in datasets such as 2.3 million energy materials from MolecularSpace, 8 million handwritten digits from MNIST, and 1 million photos from ImageNet using convolution features.
Efficient reconfiguration algorithms for degradable VLSI/WSI arrays

The development of efficient algorithms for constructing a flawless subarray from a defective VLSI/WSI (wafer scale integration) array is discussed. The array consists of identical elements such as processors or memory cells embedded in a switch lattice in the form of a rectangular grid, in contrast to the redundancy approach in which some elements are dedicated as spares, all the elements in the degradation approach are treated in a uniform way. Each element can be either fault-free or defective, and a subarray which contains no faulty element is derived under constraints of switching and routing mechanisms. Although extensive literature exists concerning spare allocation and reconfiguration in arrays with redundancy, little research has been published on optimal reconfiguration in a degradable array. A graph formulation is used to describe the problem, and reconfiguration is found to relate to finding an independent set of a graph. Efficient heuristic algorithms are presented to determine a target subarray from the defective host array. >
A positron emission tomograph designed for 3/4 mm resolution

Two factors of the design for a positron tomograph affect the magnitude of the tomograph spatial resolution: the gamma ray detector width and the analogue measurement of the scintillator location. In the tomograph design reported here the analogue measurement is eliminated and the detector transaxial width factor is reduced to 3/4 mm. The analogue measurement is eliminated by transmitting the scintillation light from each individual scintillator through optical fibers to four photomultipliers (PMT's); the identities of the PMT's then provide a digital address for the scintillation location. Plastic scintillators are used to provide enough scintillation light for transmission through the optical fibers. Bonuses from the use of plastic scintillators are first, the reduction of the scintillator dead time to about 10 nsec, second, a large reduction of crosstalk between neighboring scintillators, third, the reduction of resolution loss from off-axis gamma rays and, fourth, the ability to sample the axial image at one-eighth the axial resolution distance of 2.5 mm. The designed tomograph incorporates 20 rings. Two of the 32 tomograph 20-ring modules have been constructed to measure the resolution and other characteristics of the tomograph. >
Monetary and Macroprudential Policy Rules in a Model with House Price Booms

Using a dynamic stochastic general equilibrium (DSGE) model with housing, this paper shows that strong monetary reactions to accelerator mechanisms that push up credit growth and house prices can help macroeconomic stability. In addition, using a macroprudential instrument specifically designed to dampen credit market cycles would also provide stabilization benefits when an economy faces financial sector or housing demand shocks. However, the optimal macroprudential rule under productivity shocks is to not intervene. Therefore, it is crucial to understand the source of house price booms for the design of monetary and macroprudential policy.
Materials by design—A perspective from atoms to structures

Biological materials are effectively synthesized, controlled, and used for a variety of purposes in Nature—in spite of limitations in energy, quality, and quantity of their building blocks. Whereas the chemical composition of materials in the living world plays some role in achieving functional properties, the way components are connected at different length scales defines what material properties can be achieved, how they can be altered to meet functional requirements, and how they fail in disease states and other extreme conditions. Recent work has demonstrated this using large-scale computer simulations to predict materials properties from fundamental molecular principles, combined with experimental work and new mathematical techniques to categorize complex structure-property relationships into a systematic framework. Enabled by such categorization, we discuss opportunities based on the exploitation of concepts from distinct hierarchical systems that share common principles in how function is created, even linking music to materials science.
Where Are The Health Care Entrepreneurs? The Failure of Organizational Innovation in Health Care

Executive Summary Medical care is characterized by enormous inefficiency. Costs are higher and outcomes worse than almost all analyses of the industry suggest should occur. In other industries characterized by inefficiency, efficient firms expand to take over the market, or new firms enter to eliminate inefficiencies. This has not happened in medical care, however. This paper explores the reasons for this failure of innovation. I identify two factors as being particularly important in organizational stagnation: public insurance programs that are oriented to volume of care and not value and inadequate information about quality of care. Recent reforms have aspects that bear on these problems.
Dual Averaging for Distributed Optimization: Convergence Analysis and Network Scaling

The goal of decentralized optimization over a network is to optimize a global objective formed by a sum of local (possibly nonsmooth) convex functions using only local computation and communication. It arises in various application domains, including distributed tracking and localization, multi-agent coordination, estimation in sensor networks, and large-scale machine learning. We develop and analyze distributed algorithms based on dual subgradient averaging, and we provide sharp bounds on their convergence rates as a function of the network size and topology. Our analysis allows us to clearly separate the convergence of the optimization algorithm itself and the effects of communication dependent on the network structure. We show that the number of iterations required by our algorithm scales inversely in the spectral gap of the network, and confirm this prediction's sharpness both by theoretical lower bounds and simulations for various networks. Our approach includes the cases of deterministic optimization and communication, as well as problems with stochastic optimization and/or communication.
Conservation of helical asymmetry in chiral interactions

A theory for chiral molecular recognition and induction is presented that attributes enantioselection to electronic interactions. It assigns helicities to chiral molecules and has a chiral host or catalyst preferentially recognize or induce chirality of the same helicity. This principle of conservation of helical asymmetry agrees well with many experiments, accommodates results that conventional steric reasoning cannot, and promises predictive power. The work suggests that helical electronic effects may generally exert greater control than steric effects in enantioselection.
The Reaction of Thio Acids with Azides: A New Mechanism and New Synthetic Applications

A new amide synthesis strategy based on a fundamental mechanistic revision of the reaction of thio acids and organic azides is presented. The data demonstrate that amines are not formed as intermediates in this reaction. Alternative mechanisms proceeding through a thiatriazoline intermediate are suggested. The reaction has been applied to the preparation of simple and architecturally complex amides that are difficult to access using conventional methods. The reaction is chemoselective, effective for unprotected substrates, and compatible with aprotic and protic solvents, including water.
How much can taxes help selfish routing

We study economic incentives for influencing selfish behavior in networks. We consider a model of selfish routing in which the latency experienced by network traffic on an edge of the network is a function of the edge congestion, and network users are assumed to selfishly route traffic on minimum-latency paths. The quality of a routing of traffic is historically measured by the sum of all travel times, also called the total latency. It is well known that the outcome of selfish routing (a flow at Nash equilibrium) does not minimize the total latency, and that marginal cost pricing-charging each network user for the congestion effects caused by its presence-eliminates the inefficiency of selfish routing. However, the principle of marginal cost pricing assumes that taxes cause no disutility to network users; this is appropriate only when collected taxes can be feasibly returned (directly or indirectly) to the users. If this assumption does not hold and we wish to minimize the total user disutility (latency plus taxes paid)-the total cost-how should we price the network edges? Intuition may suggest that taxes can never improve the cost of a Nash equilibrium, but the famous Braess's Paradox shows this intuition to be incorrect. We consider strategies for pricing network edges to reduce the cost of a Nash equilibrium. Since levying a sufficiently large tax on an edge effectively removes it from the network, our study generalizes previous work on designing networks for selfish users [T. Roughgarden, Designing networks for selfish users is hard, in: Proceedings of the 42nd Annual Symposium on Foundations of Computer Science (FOCS), 2001, pp. 472-481 (full version to appear in Journal of Computer and System Sciences)]. In this paper, we prove the following results.*In a large class of networks-including all networks with linear latency functions-marginal cost taxes do not improve the cost of a Nash equilibrium. *The largest-possible benefit from taxes does not exceed that from edge removals. In every network with linear latency functions, the benefit of taxes cannot exceed that of removing edges. There are networks with nonlinear latency functions, however, in which taxes are radically more powerful than edge removals. *For every @e>0, there is no ([email protected])-approximation algorithm for computing optimal taxes, even in networks with linear latency functions (assuming P NP).
NgViz: detecting DNS tunnels through n-gram visualization and quantitative analysis

This paper introduced NgViz, a tool that examines DNS traffic and shows anomalies in n-gram frequencies. This is accomplished by comparing input files against a fingerprint of legitimate traffic. Both quantitative analysis and visual aids are provided that allow the user to make determinations about the legitimacy of the DNS traffic.
Public-Key Cryptosystems from the Worst-Case Shortest Vector Problem

We construct public-key cryptosystems that are secure assuming the *worst-case* hardness of approximating the shortest vector problem on lattices. Prior cryptosystems with worst-case connections (e.g., the Ajtai-Dwork system) were based either on a *special case* of the shortest vector problem, or on the conjectured hardness of lattice problems for *quantum* algorithms. Our main technical innovation is a reduction from certain variants of the shortest vector problem to corresponding versions of the "learning with errors" (LWE) problem; previously, only a quantum reduction of this kind was known. In addition, we construct new cryptosystems based on LWE, including a very natural chosen ciphertext-secure system that has a much simpler description and tighter underlying worst-case approximation factor than prior constructions. (Duration: 30 minutes, on or before Wednesday.)
The Influence of Self-Construal on Impulsive Consumption

Three studies investigated the impact of self-construal on impulsive consumption. Independents exhibited more impulsive consumption tendencies than did interdependents. A chronically accessible independent self-construal was positively associated with country-level beer consumption (study 1a) and state-level problem alcohol consumption (study 1b). Experimentally primed independents reported more positive attitudes toward immediate beer consumption than did interdependents, and this effect was mediated by state impulsivity. Peer presence increased impulsive consumption tendencies for independents but decreased them for interdependents (studies 2 and 3). The moderating effect of self-construal was linked to greater motivation to suppress impulsive tendencies for interdependents than for independents (study 3).
Space-time trellis code design based on super QOSTBC with minimum decoding complexity

We propose a new family of space-time trellis codes, which are constructed by combining a super set of QOSTBC with minimum decoding complexity and an outer MTCM encoder. A systematic set-partitioning method for QAM constellations is given. The proposed scheme can be used for systems with four and more than four transmit antennas. Furthermore, its decoding complexity is low because branch metric calculations can be done in a symbol-wise way. Several design examples are presented. Simulation results demonstrate that the proposed scheme has a comparable performance as super quasi-orthogonal space-time trellis codes presented by Jafarkhani and Hassanpour while providing a lower decoding complexity.
A Comparison of Two Alternative Approaches to Modeling Level Shifts in the Presence of Outliers

We study alternative models for capturing abrupt structural changes (level shifts) in a times series. The problem is confounded by the presence of transient outliers. We compare the performance of non-Gaussian time-varying parameter models and multiprocess mixture models within a Monte Carlo experimental setup. Our findings suggest that once we incorporate shocks with thick-tailed probability distributions, the superiority of the multiprocess mixture models over the time-varying parameter models, reported in an earlier study, disappears. The behavior of the two models, both in adapting to level shifts and in reacting to transient outliers, is very similar.
Stability of Peakons for the Degasperis-Procesi Equation

The Degasperis-Procesi equation can be derived as a member of a oneparameter family of asymptotic shallow water approximations to the Euler equations with the same asymptotic accuracy as that of the CamassaHolm equation. In this paper, we study the orbital stability problem of the peaked solitons to the Degasperis-Procesi equation on the line. By constructing a Liapunov function, we prove that the shapes of these peakon solitons are stable under small perturbations.
Analysis of the X‐ray emission of nine Swift afterglows

The X-ray light curves of nine Swift XRT afterglows (050126, 050128, 050219A, 050315, 050318, 050319, 050401, 050408 and 050505) display a complex behaviour: a steep t −3.0±0.3 decay until ∼400 s, followed by a significantly slower t −0.65±0.20 fall-off, which at 0.2‐ 2 day after the burst evolves into a t −1.7±0.5 decay. We consider three possible models for the geometry of relativistic blast-waves (spherical outflows, non-spreading jets and spreading jets), two possible dynamical regimes for the forward shock (adiabatic and fully radiative), and we take into account a possible angular structure of the outflow and delayed energy injection in the blast-wave to identify the models which reconcile the X-ray light-curve decay with the slope of the X-ray continuum for each of the above three afterglow phases. By piecing together the various models for each phase in a way that makes physical sense, we identify possible models for the entire X-ray afterglow. The major conclusion of this work is that a long-lived episode of energy injection in the blast-wave, during which the shock energy increases at t 1.0±0.5 , is required for five afterglows and could be at work in the other four as well. For some afterglows, there may be other mechanisms that can explain the t < 400 s fast falling-off X-ray light curve (e.g. the large-angle gamma-ray burst emission), the 400 s to 5 h slow decay (e.g. a structured outflow), or the steepening at 0.2‐2 day (e.g. a jet-break, a collimated outflow transiting from a wind with a r −3 radial density profile to a homogeneous or outward-increasing density region). Optical observations in conjunction with the X-ray can distinguish among these various models. Our simple tests allow the determination of the location of the cooling frequency relative to the X-ray domain and, thus, of the index of the electron power-law distribution with energy in the blast-wave. The resulting indices are clearly inconsistent with a universal value.
USING KUIPER BELT BINARIES TO CONSTRAIN NEPTUNE'S MIGRATION HISTORY

Approximately 10‐20% of all Kuiper belt objects (KBOs) occupy mean-motion resonances with Neptune. This dynamical configuration likely resulted from resonance capture as Neptune migrated outward during the late stages of planet formation. The details of Neptune’s planetesimal-driven migration, including its radial extent and the concurrent eccentricity evolution of the planet, are the subject of considerable debate. Two qualitatively di! erent proposals for resonance capture have been proposed—migration-induced capture driven by smooth outward evolution of Neptune’s orbit and chaotic capture driven by damping of the planet’s eccentricity near its current semi-major axis. We demonstrate that the distribution of comparable-mass, wide-separation binaries occupying resonant orbits can di! erentiate between these two scenarios. If migration-induced capture occurred, this fraction records information about the formation locations of di! erent populations of KBOs. Chaotic capture, in contrast, randomizes the orbits of bodies as they are placed in resonance. In particular, if KBO binaries formed by dynamical capture in a protoplanetary disk with a surface mass density typical of observed extrasolar disks, then migration-induced capture produces the following signatures. The 2:1 resonance should contain a dynamically cold component, with inclinations less than 5‐10 ! , having a binary fraction comparable to that among cold classical KBOs. If the 3:2 resonance also hosts a cold component, its binary fraction should be 20‐30% lower than in the cold classical belt. Among cold 2:1 (and if present 3:2) KBOs, objects with eccentricities e 0.2. Other binary formation scenarios and disk surface density profiles can generate analogous signatures but produce quantitatively di! erent results. Searches for cold components in the binary fractions of resonant KBOs are currently practical. The additional migration-generated trends described here may be distinguished with objects discovered by LSST. Subject headings: celestial mechanics — Kuiper belt: general — planet-disk interactions — planets and satellites: formation
Modeling of a 1700-MHz cluster cavity of planar triodes

The authors present the modeling and design of a 1700-MHz cluster-cavity vacuum tube amplifier. They used a three-dimensional finite-difference code to characterize the modes that the structure would support and to modify the cavity design in order to select the desired mode. The characteristics of the tube are described, including performance predictions. The feasibility of a resonant structure is considered that supports a combination of four planar triodes without external combiners. Only the output resonator is described. The design locates the planar triodes in sections of rectangular waveguide with movable end walls that provide each tube with an independent loading adjustment. In addition, the waveguide sections help to increase the resonant frequency of the dipole and quadrupole modes with respect to a cylindrical structure of comparable size. A number of planar triodes can be combined in a resonant structure to increase the power level of vacuum tube amplifiers at high frequencies, resulting in a low-cost source of RF for medium-power applications. >
Outlier elimination for robust ellipse and ellipsoid fitting

In this paper, an outlier elimination algorithm for ellipse/ellipsoid fitting is proposed. This two-stage algorithm employs a proximity-based outlier detection algorithm (using the graph Laplacian), followed by a model-based outlier detection algorithm similar to random sample consensus (RANSAC). These two stages compensate for each other so that outliers of various types can be eliminated with reasonable computation. The outlier elimination algorithm considerably improves the robustness of ellipse/ellipsoid fitting as demonstrated by simulations.
Drag-Modulation Flight-Control System Options for Planetary Aerocapture

Drag-modulation flight control may provide a simple method for controlling energy during aerocapture. Several drag-modulation flight-control system options are discussed and evaluated, including single-stage jettison, two-stage jettison, and continuously variable drag-modulation systems. Performance is assessed using numeric simulation with real-time guidance and targeting algorithms. Monte Carlo simulation is used to evaluate system robustness to expected day-of-flight uncertainties. Results indicate that drag-modulation flight control is an attractive option for aerocapture systems at Mars, where low peak heat rates enable the use of lightweight inflatable drag areas. Aerocapture using drag modulation at Titan is found to require large drag areas to limit peak heat rates to nonablative thermal-protection system limits or advanced lightweight ablators. The large gravity well and high peak heat rates experienced during aerocapture at Venus make drag-modulation flight control unattractive when combined wit...
Euro area inflation persistence

This paper presents evidence on the lag between monetary policy actions and the response of inflation in the euro area as a whole as well as in some of its core countries, notably Germany, Italy and France. In line with previous findings for the US and the UK, results here show that it takes over a year before monetary policy actions have their maximum effect on inflation both in the euro area and in individual countries and that a lag of this length has existed in Europe at least since the collapse of the Bretton Woods system, despite the numerous changes in European monetary policy regime thereafter. Results based on alternative definitions of inflation persistence support these findings and indicate, if any, that transmission lags could be in fact much longer for individual countries and the euro area as a whole, although, at the country level, there is strong evidence over time of a drop in German inflation persistence and a sizeable shift in the mean of inflation – particularly in Italy and France. An examination based on results from this paper reveals that euro area inflation persistence could well be an intrinsic phenomenon rather than a ‘statistical fluke’ due to aggregation.
Fast and reliable collision culling using graphics hardware

We present a reliable culling algorithm that enables fast and accurate collision detection between triangulated models in a complex environment. Our algorithm performs fast visibility queries on the GPUs for eliminating a subset of primitives that are not in close proximity. In order to overcome the accuracy problems caused by the limited viewport resolution, we compute the Minkowski sum of each primitive with a sphere and perform reliable 2.5D overlap tests between the primitives. We are able to achieve more effective collision culling as compared to prior object-space culling algorithms. We integrate our culling algorithm with CULLIDE and use it to perform reliable GPU-based collision queries at interactive rates on all types of models, including nonmanifold geometry, deformable models, and breaking objects.
INEX simulations of the Los Alamos HIBAF free-electron laser MOPA experiment

Abstract We present results of Integrated Numerical Experiment (INEX) simulations of the performance of a 1 m untapered wiggler FEL oscillator driving a 2 m wiggler FEL amplifier for the new HIBAF (high-brightness accelerator free-electron laser) facility at Los Alamos. INEX simulations utilize a numerically generated electron micropulse, from ISIS/PARMELA calculations of the photoinjector/ linac/beam-transport system, in the 3D FEL simulation code FELEX.
Phase-space distributions of chemical abundances in Milky Way-type Galaxy halos.

Motivated by upcoming data from astrometric and spectroscopic surveys of the Galaxy, we explore the chemical abundance properties and phase-space distributions in hierarchically formed stellar halo simulations set in a CDM universe.Our stellar halometallicities increase with stellar halo mass. Theslope of the ½Fe/H � -Mtrend mimics that of the satellite galaxies that were destroyed to build the halos, implying that the relation propagates hierarchically. All simulatedhaloscontainasignificantfractionofoldstellarpopulationsaccretedmorethan10Gyrago,andinafewcases some intermediate-age populations exist. In contrast with the Milky Way, many of our simulated stellar halos contain old stellar populations that are metal-rich, originating in the early accretion of massive satellites (M� � 10 9 M� ). We suggest that the (metal-rich) stellar halo of M31 falls into this category, while the more metal-poor halo of the Milky Way is lacking in early massive accretion events. Interestingly, our hierarchically formed stellar halos often have nonnegligible metallicity gradients in both (Fe/H) and (� /Fe). These gradients extend a few tens of kiloparsecs, and can beas large as 0.5dex in(Fe/H) and 0.2dex in (� /Fe), with the most metal-poor halo stars typicallyburied within the central � 5 kpc of the galaxy. Finally, we find that chemical abundances can act as a rough substitute for time of accretion of satellite galaxies, and, based on this finding, we propose a criterion for identifying tidal streams spatially by selecting stars with (� /Fe) ratios below solar. Subject headingg cosmology: theory — galaxies: abundances — galaxies: evolution
A Fuzzy Logic Based Algorithm for Finding Astronomical Objects in Wide-Angle Frames

Accurate automatic identification of astronomical objects in an imperfect world of non-linear wide-angle optics, imperfect optics, inaccurately pointed telescopes, and defect-ridden cameras is not always a trivial first step. In the past few years, this problem has been exacerbated by the rise of digital imaging, providing vast digital streams of astronomical images and data. In the modern age of increasing bandwidth, human identifications are many times impracticably slow. In order to perform an automatic computer-based analysis of astronomical frames, a quick and accurate identification of astronomical objects is required. Such identification must follow a rigorous transformation from topocentric celestial coordinates into image coordinates on a CCD frame. This paper presents a fuzzy logic based algorithm that estimates needed coordinate transformations in a practical setting. Using a training set of reference stars, the algorithm statically builds a fuzzy logic model. At runtime, the algorithm uses this model to associate stellar objects visible in the frames to known cataloged objects, and generates files that contain photometry information of objects visible in the frame. Use of this algorithm facilitates real-time monitoring of stars and bright transients, allowing identifications and alerts to be issued more reliably. The algorithm is being implemented by the Night Sky Live all-sky monitoring global network and has shown itself significantly more reliable than the previously used non-fuzzy logic algorithm.
The Supreme Court and Public Opinion: Judicial Decision Making in the Post- New Deal Period

The countermajoritarian activism of the Supreme Court is usually assessed in terms of the willingness of the Court to overturn legislation and/or to protect minorities. Using these criteria, the post-New Deal Supreme Court emerges as an exceptionally active countermajoritarian decision-making institution. It is also important, however, to examine the relationship between the Court's decisions and public opinion. Such an examination reveals that the Court's decisions overturning legislation and/or protecting minority rights were often supported by the distribution or at least the trend of nationwide public opinion and that when such support was lacking, the Court seemed reluctant to act. Thus, the policymaking activism of the post-New Deal Supreme Court was perhaps more consistent with majoritarian principles than is sometimes supposed.
Syntheses, structures and properties of primarily nanosized homo/heterometallic palladium CO/PR3-ligated clusters

Syntheses, properties and structures of nanosized palladium CO/PR(3)-ligated homo- and heterometallic clusters containing up to 165 metal atoms are the focus of this review. The work discussed is primarily that of the authors and their coworkers. We propose that the unparalleled variety of structural types and the distinctive reactivities of neutral Pd(n)(CO)(x)(PR(3))(y) clusters composed of zerovalent Pd atoms are a consequence of relatively weak Pd-L(ligand) and Pd(0)-Pd(0) interactions that result from the stable 5s(0)4d(10) closed-shell electron configuration of atomic Pd in its ground state.
A cyclic switching strategy for parameter-adaptive control

This paper introduces a new strategy, called "cyclic switching," to deal with the well-known certainty equivalence control synthesis problem which arises in the design of identifier-based adaptive controllers because of the existence of points in parameter space where the design model /spl Sigma//sub D/, upon which certainty equivalence synthesis is based, loses stabilizability. Unlike most previously suggested methods for handling this problem, the technique proposed here can be employed with or without process excitation. For the technique to work it is not necessary for there to be a mechanism for moving tuned parameters away from values at which /spl Sigma//sub D/ loses stabilizability, and no such mechanism is used. >
Smart rooms, smart clothes

To change inanimate objects like offices, houses, cars, or glasses into smart, active helpmates they need to have perceptual intelligence. They need to begin paying attention to people and the surrounding situation the way another person would. That way they can begin to adapt their behavior to us, rather than the other way around. We have developed computer systems that can follow people's actions, recognizing their faces, gestures, and expressions. Using this technology we have begun to make "smart rooms" and "smart clothes" that can help people in day-to-day life, have the potential to recognize people, understand their speech, allow them to control computer displays without wires or keyboards, communicate by sign language, and warn them they are about to make a mistake.
Orthogonal rendezvous routing protocol for wireless mesh networks

Routing in multi-hop wireless networks involves the indirection from a persistent name (or ID) to a locator. Concepts such as coordinate space embedding help reduce the number and dynamism complexity of bindings and state needed for this indirection. Routing protocols which do not use such concepts often tend to flood packets during route discovery or dissemination, and hence have limited scalability. In this paper, we introduce Orthogonal Rendezvous Routing Protocol (ORRP) for meshed wireless networks. ORRP is a lightweight-but-scalable routing protocol utilizing directional communications (such as directional antennas or free-space-optical transceivers) to relax information requirements such as coordinate space embedding and node localization. The ORRP source and ORRP destination send route discovery and route dissemination packets respectively in locally-chosen orthogonal directions. Connectivity happens when these paths intersect (i.e., rendezvous). We show that ORRP achieves connectivity with high probability even in sparse networks with voids. ORRP scales well without imposing DHT-like graph structures (eg: trees, rings, torus etc). The total state information required is O(N3/2) for N-node networks, and the state is uniformly distributed. ORRP does not resort to flooding either in route discovery or dissemination. The price paid by ORRP is suboptimality in terms of path stretch compared to the shortest path; however we characterize the average penalty and find that it is not severe.
Superconductivity, diamagnetism, and the mean inner potential of solids

The mean inner potential of a solid is known to be proportional to its diamagnetic susceptibility. Superconductors exhibit giant diamagnetism. What does this say about the connection between superconductivity and mean inner potential? Nothing, according to the conventional theory of superconductivity. Instead, it is proposed that a deep connection exists between the mean inner potential, diamagnetism, and superconductivity: that they are all intimately linked to the fundamental charge asymmetry of matter. It is discussed how this physics can be probed experimentally and what the implications of different experimental findings would be for the understanding of superconductivity.
Optimally Dense Packings of Hyperbolic Space

In previous work, a probabilistic approach to controlling difficulties of density in hyperbolic space led to a workable notion of optimal density for packings of bodies. In this paper we extend an ergodic theorem of Nevo to provide an appropriate definition of those packings to be considered optimally dense. Examples are given to illustrate various aspects of the density problem, in particular the shift in emphasis from the analysis of individual pack- ings to spaces of packings.
Total synthesis of atroviridin

Abstract A total synthesis of atroviridin ( 1 ) based on biosynthetic principles is presented. The tetracyclic xanthone structure of the natural product was constructed by coupling aryl bromide 8 with aldehyde 7 and subsequent intramolecular conjugate addition on a quinone precursor. Bromide 8 was produced from aldehyde 9 via a sequence of steps involving Baeyer–Villiger oxidation and Claisen cyclization.
An efficient protocol for call setup and path migration in IEEE 802.6 based personal communication networks

Recently, DQDB (IEEE 802.6) MAN has been proposed as a component of Personal Communication Networks, in which base stations of wireless infrastructures are connected by a number of DQDBs which in turn are connected via bridges. We propose a protocol for call setup and path migration in a cluster of DQDBs. The protocol uses a link-state-like routing method for path selection and a source-routing-based scheme for path establishment. In addition, we propose a labeling scheme that makes it possible to carry the path information needed by the source routing protocol in a single 53-octet DQDB slot. Without such a labeling scheme, source routing would be inefficient for our purpose.
Designing experiments to measure spillover effects

This paper formalizes the design of experiments intended specifically to study spillover effects. By first randomizing the intensity of treatment within clusters and then randomly assigning individual treatment conditional on this cluster-level intensity, a novel set of treatment effects can be identified. The paper develops a formal framework for consistent estimation of these effects, provides explicit expressions for power calculations, and shows that the power to detect average treatment effects declines precisely with the quantity that identifies the novel treatment effects. A demonstration of the technique is provided using a cash transfer program in Malawi.
The Wall of the cave

In this article old and new relations between gauge fields and strings are discussed. We add new arguments that the Yang–Mills theories must be described by the noncritical strings in the five-dimensional curved space. The physical meaning of the fifth dimension is that of the renormalization scale represented by the Liouville field. We analyze the meaning of the zigzag symmetry and show that it is likely to be present if there is a minimal supersymmetry on the world sheet. We also present the new string backgrounds which may be relevant for the description of the ordinary bosonic Yang–Mills theories. The article is written on the occasion of the 40th anniversary of the IHES.
Liouville theory: Ward identities for generating functional and modular geometry

We continue the study of quantum Liouville theory through Polyakov’s functional integral,1,2 started in Ref. 3. We derive the perturbation expansion for Schwinger’s generating functional for connected multi-point correlation functions involving stress-energy tensor, give the “dynamical” proof of the Virasoro symmetry of the theory and compute the value of the central charge, confirming previous calculation in Ref. 3. We show that conformal Ward identities for these correlation functions contain such basic facts from Kahler geometry of moduli spaces of Riemann surfaces, as relation between accessory parameters for the Fuchsian uniformization, Liouville action and Eichler integrals, Kahler potential for the Weil-Petersson metric, and local index theorem. These results affirm the fundamental role that universal Ward identities for the generating functional play in Friedan-Shenker modular geometry.4
Observations on chytridiaceous parasites of phanerogams

A reexamination of Physoderma maculare Wallroth the type species of the genus, on Alisma, confirms Clinton's (1902) account of the production of an epibiotic stage from resting spore zoospores. The latter on mature host tissue may also give rise to the endobiotic stage which bears resting spores. On seedlings, however, resting spore zoospores produce only epibiotic sporangia. The fungus could not successfully infect Sagittaria, a closely related host.