cssi/SciSciGPT-SciSciNet huggingface dataset:
Adaptive servoregulation of a projectile fin using piezoelectric actuator

This brief paper treats the question of adaptive control of a projectile fin using a piezoelectric actuator. The hollow projectile fin is rigid, within which a flexible cantilever beam with a piezoelectric active layer is mounted. The model of the fin-beam system includes the aerodynamic moment, which is a function of angle of attack of the projectile. The rotation angle of the fin is controlled by deforming the flexible beam, which is hinged at the tip of the rigid fin. An adaptive servoregulator is designed for the control of the fin angle using the fin angle and its derivative for feedback. Interestingly, the knowledge of the dimension and parameters of the system is not essenstial for the synthesis of the control law. In the closed-loop system, the fin angle asymptotically converges to the desired set point and the elastic modes converge to their equilibrium values. Computer simulation and laboratory test results are presented to show the performance of the controller.
The Quest to Understand the Pioneer Anomaly

The Pioneer 10/11 missions, launched in 1972 and 1973, and their navigation are reviewed. Beginning in about 1980 an unmodeled force of {approx} 8 x 10{sup -8} cm/s{sup 2} appeared in the tracking data, it later being verified. The cause remains unknown, although radiant heat remains a likely origin. A set of efforts to find the solution are underway: (a) analyzing in detail all available data, (b) using data from the New Horizons mission, and (c) considering an ESA dedicated mission.
Oxygen consumption and temperature acclimation in the northern prairie swift Sceloporus undulatus garmani from Kansas

1. 1. O2 consumption rates of Sceloporus undulatus garmani were determined diurnally and nocturnally at acclimation temperatures of 20, 25, 30 and 35°C. 2. 2. Day and night rates increased significantly with increases in temperature except between 30 and 35°C, where Q10s were 1.2 and 1.8 respectively. 3. 3. Partial metabolic compensation between 30 and 35°C corresponded with the northern prairie swift's range (30–37°C) of diurnal body temperatures during its seasonal active period (May–October). 4. 4. Daytime rates were significantly higher (X = 1.85 times) than night-time rates at all temperatures.
Synthesis and characterization of 1,2-bis(2'-pyrazineethynyl) benzene palladium(II) dichloride and its catalysis of the Suzuki coupling reaction

Abstract We report the synthesis and characterization of a new palladium complex, 1,2‐bis(2′‐pyrazineethynyl)benzene palladium(II) dichloride, and the catalysis of the Suzuki coupling reaction with this complex.
Investigation of electrodeless conductivity as a technique for monitoring sulfate levels during production of wet-process phosphoric acid.

In the production of wet-process phosphoric acid (WPA), sulfate concentrations influence both the crystal form and growth rate of calcium sulfate and hence the filtration rate for separating calcium sulfate from the product WPA. The filtration rate must be rapid to maintain high rates for the production of WPA. One approach for continuously monitoring sulfate concentrations during production of WPA is to measure the electrical conductivity, temperature, and specific gravity of WPA, and then relate these data to the sulfate concentration using regression equations. An electrodeless conductivity probe was used to provide reproducible conductivity measurements in return acids (12–32% P2O5) used for the production of WPA (24–36% P2O5). The effect of iron, aluminum, and magnesium impurities on the conductivity measurements was also evaluated. Regression equations were developed from the data which can be used to accurately calculate P2O5 and sulfate concentrations in return acids within a specified temperature range.
A second look at the geologic map of China: The "Sloss approach"

A key tool for geologic or tectonic reconstruction is the geologic map. When one attempts to understand an area as large and complicated as China, this tool contains more information than is optimal. The presence of too much detail can obscure important general trends. To facilitate the understanding of the major tectonic events that took place in China during the Phanerozoic, the geologic and tectonic maps of China are simplified and recast in an easily interpretable format. A methodology is presented that is similar to the one introduced by L. L. Sloss in the early days of plate tectonics and sequence stratigraphy. Each tectonic zone of China is represented by one "Sloss curve," which is a time-series representation of the geologic map. The curve shape reflects the geological response to tectonic changes. Patterns emerge when the "Sloss curves" are compared and correlated between the tectonic zones. The compiled "Sloss map" can be used as a low-pass filter of tectonic events. Two events clearly stand ou...
Building scalable and robust peer-to-peer overlay networks for broadcasting using network coding

We propose a scheme for building peer-to-peer overlay networks for broadcasting using network coding. The scheme addresses many practical issues such as scalability, robustness, constraints on bandwidth, and locality of decisions. We analyze the system theoretically and prove near optimal bounds on the parameters defining robustness and scalability. As a result we show that the effects of failures are contained locally, allowing the network to grow exponentially with server load. We also argue that adversarial failures are no more harmful than random failures.
The design of a meta-system

The design and implementation of multiprogrammed, time-sharing computer systems continues long after the system is put to use. A tool is needed that will measure and evaluate the computer system while it is in operation, as an aid to further development or optimization for a particular usage. Research into the possibility of developing this tool was undertaken at the University of Pennsylvania's Moore School of Electrical Engineering. The research led to the design of the tool, which is presented in this report. It is called the Meta-system.
Designing Polymer Blends Using Neural Networks, Genetic Algorithms, and Markov Chains

In this paper we present a new technique to simulate polymer blends that overcomes the shortcomings in polymer system modeling. This method has an inherent advantage in that the vast existing information on polymer systems forms a critical part in the design process. The stages in the design begin with selecting potential candidates for blending using Neural Networks. Generally the parent polymers of the blend need to have certain properties and if the blend is miscible then it will reflect the properties of the parents. Once this step is finished the entire problem is encoded into a genetic algorithm using various models as fitness functions. We select the lattice fluid model of Sanchez and Lacombe (J. Polym. Sci. Polym. Lett. Ed., vol. 15, p. 71, 1977), which allows for a compressible lattice. After reaching a steady-state with the genetic algorithm we transform the now stochastic problem that satisfies detailed balance and the condition of ergodicity to a Markov Chain of states. This is done by first creating a transition matrix, and then using it on the incidence vector obtained from the final populations of the genetic algorithm. The resulting vector is converted back into a population of individuals that can be searched to find the individuals with the best fitness values. A high degree of convergence not seen using the genetic algorithm alone is obtained. We check this method with known systems that are miscible and then use it to predict miscibility on several unknown systems.
Finite element analysis of the LOLA receiver telescope lens

This paper presents the finite element stress and distortion analysis completed on the receiver telescope lens of the Lunar Orbiter Laser Altimeter (LOLA). LOLA is one of six instruments on the Lunar Reconnaissance Orbiter (LRO), scheduled to launch in 2008. LOLA's main objective is to produce a high-resolution global lunar topographic model to aid in safe landings and enhance surface mobility in future exploration missions. A receiver telescope captures the laser pulses transmitted through a diffractive optical element (DOE) and reflected off the lunar surface. The largest lens of the receiver telescope was modeled with solid elements and constrained in a manner consistent with the behavior of the mounting configuration. Twenty-one temperature load cases were mapped to the nodes based on thermal analysis completed by LOLA's lead thermal analyst, and loads were applied to simulate the preload applied from the ring flexure. The thermal environment of the baseline design produces large radial and axial gradients in the lens. These large gradients create internal stresses that may lead to part failure, as well as significant bending that degrades optical performance. The high stresses and large distortions shown in the analysis precipitated a design change from BK7 glass to sapphire.
Diffusive-to-ballistic transition in grain boundary motion studied by atomistic simulations

An adapted simulation method is used to systematically study grain boundary motion at velocities and driving forces across more than five orders of magnitude. This analysis reveals that grain boundary migration can occur in two modes, depending upon the temperature ($T$) and applied driving force ($P$). At low $P$ and $T$, grain boundary motion is diffusional, exhibiting the kinetics of a thermally activated system controlled by grain boundary self-diffusion. At high $P$ and $T$, grain boundary migration exhibits the characteristic kinetic scaling behavior of a ballistic process. A rather broad transition range in both $P$ and $T$ lies between the regimes of diffusive and ballistic grain boundary motion, and is charted here in detail. The recognition and delineation of these two distinct modes of grain boundary migration also leads to the suggestion that many prior atomistic simulations might have probed a different kinetic regime of grain boundary motion (ballistic) as compared to that revealed in most experimental studies (diffusional).
Locality principle revisited: A probability-based quantitative approach

Abstract This paper revisits the fundamental concept of the locality of references and proposes to quantify it as a conditional probability: in an address stream, given the condition that an address is accessed, how likely the same address (temporal locality) or an address within its neighborhood (spatial locality) will be accessed in the near future. Previous works use reuse distance histograms as a measure of temporal locality. For spatial locality, some ad hoc metrics have been proposed as a quantitative measure. In contrast, our conditional probability-based locality measure has a clear mathematical meaning and provides a theoretically sound and unified way to quantify both temporal and spatial locality. We showcase that our quantified locality measure can be used to evaluate compiler optimizations, to analyze the locality at different levels of memory hierarchy, to optimize the cache architecture to effectively leverage the locality, and to examine the effect of data prefetching mechanisms.
Embedding pointed curves in K3 surfaces

We analyze morphisms from pointed curves to K3 surfaces with a distinguished rational curve, such that the marked points are taken to the rational curve, perhaps with specified cross ratios. This builds on work of Mukai and others characterizing embeddings of curves into K3 surfaces via non-abelian Brill–Noether theory. Our study leads naturally to enumerative problems, which we solve in several specific cases. These have applications to the existence of sections of del Pezzo fibrations with prescribed invariants.
The CAPMAP instrument and its first season

Abstract I describe here the new C osmic A nisotropy P olarization MAP er (CAPMAP) instrument, which performed its first season of observing between February and April 2003 from the Crawford Hill 7-m antenna in NJ. CAPMAP is based on the design for the PIQUE instrument, but has better sensitivity and superior angular resolution.
Sebaceous carcinoma arising in a benign dermoid cyst of the ovary

Sebaceous carcinoma in a ovarian dermoid cyst is a rare entity. The present patient has survived 54 months and has no evidence of recurrence after total abdominal hysterectomy, bilateral salpingoophorectomy and adjuvant chemotherapy with cisplatin, vinblastin, and bleomycin.
EXAFS study of local order in the amorphous chalcogenide semiconductor Ge2Sb2Te5

Abstract Studies of amorphous ( a -) semiconductors have been driven by technological advances as well as fundamental theories. Observation of electrical switching, for example, fueled early interest in a -chalcogenides. More recently switching of the a -chalcogenide Ge 2 Sb 2 Te 5 has been applied quite successfully to DVD technology where the quest for the discovery of better-suited materials continues. Thus, switching provides researchers today with an active arena of technological as well as fundamental study. On the theoretical front, bond constraint theory — or BCT — provides a powerful framework for understanding the structure and properties of a -materials. Applications of BCT to switching in Ge 2 Sb 2 Te 5 holds the promise of finding the best composition suited for switching applications. This work presents EXAFS data that describe local bonding configurations in as-deposited Ge 2 Sb 2 Te 5 . The data show that Ge 2 Sb 2 Te 5 may best be viewed as a random array of Ge 2 Te 3 and Sb 2 Te 3 structural units imbedded in a tissue of a -Te, 17% of which is over coordinated. In addition, a valence alternation pair defect is introduced to the model to satisfy charge conservation constraints.
Novel Sulfinyl Imine Ligands for Asymmetric Catalysis

A novel class of P,N-sulfinyl imine ligands has been prepared that incorporates chirality solely at sulfur. The Pd complex of ligand 14 catalyzes the allylic alkylation reaction with high enantioselectivity (94%), and the first crystal structure of a Pd-bound sulfinyl imine provides insight into binding mode and origins of stereoselectivity.
Application of guidelines for designing user interface software

Abstract A survey was conducted of people who had received a report on guidelines for designing user interface software. Analysis of questionnaire responses indicates that respondents considered guidelines useful, that they have used guidelines in various stages of design, and that they plan to use guidelines again. However, respondents also reported significant problems in the practical application of guidelines. Respondents had difficulty locating relevant guidelines within the report, choosing which guidelines would actually be used, establishing priorities among the selected guidelines, and translating generally worded guidelines into specific design rules.
Simulating reionization in numerical cosmology

Abstract The incorporation of radiative transfer effects into cosmological hydrodynamical simulations is essential for understanding how the intergalactic medium (IGM) makes the transition from a neutral medium to one that is almost fully ionized. Here, we present an approximate numerical method designed to study in a statistical sense, how a cosmological density field is ionized by a set of discrete point sources. A diffuse background radiation field is also computed self-consistently in our procedure. The method requires relatively few time steps and can be employed with simulations having high resolution. We describe the details of the algorithm and provide a description of how the method can be applied to the output from a pre-existing cosmological simulation to study the systematic reionization of a particular ionic species. As a first application, we compute the reionization of He II by quasars in the range 3≲ z ≲6.
The X-Ray Structure and Spectrum of the Pulsar Wind Nebula Surrounding PSR B1853+01 in W44

We present the result of a Chandra ACIS observation of the pulsar PSR B1853+01 and its associated pulsar wind nebula (PWN), embedded within the supernova remnant W44. A hard band ACIS map cleanly distinguishes the PWN from the thermal emission of W44. The nebula is extended in the north-south direction, with an extent about half that of the radio emission. Morphological differences between the X-ray and radio images are apparent. Spectral fitting reveals a clear difference in spectral index between the hard emission from PSR B1853+01 (Gamma approx. 1.4) and the extended nebula (Gamma approx. 2.2). The more accurate values for the X-ray flux and spectral index are used refine estimates for PWN parameters, including magnetic field strength, the average Lorentz factor gamma of the particles in the wind, the magnetization parameter sigma, and the ratio k of electrons to other particles.
Correlated forward-backward dissociation and neutron spectra as a luminosity monitor in heavy-ion colliders

Abstract Detection in zero degree calorimeters of the correlated forward–backward Coulomb or nuclear dissociation of two colliding nuclei is presented as a practical luminosity monitor in heavy-ion colliders. Complementary predictions are given for total correlated Coulomb plus nuclear dissociation and for correlated forward–backward single neutrons from the giant dipole peak.
Transfer of Gorenstein dimensions along ring homomorphisms

Abstract A central problem in the theory of Gorenstein dimensions over commutative noetherian rings is to find resolution-free characterizations of the modules for which these invariants are finite. Over local rings, this problem was recently solved for the Gorenstein flat and the Gorenstein projective dimensions; here we give a solution for the Gorenstein injective dimension. Moreover, we establish two formulas for the Gorenstein injective dimension of modules in terms of the depth invariant; they extend formulas for the injective dimension due to Bass and Chouinard.
Simple Systems with Anomalous Dissipation and Energy Cascade

We analyze a class of dynamical systems of the type \(\dot a_n(t) = c_{n-1} a_{n-1}(t) - c_n a_{n+1}(t) + f_n(t), n \epsilon {{\mathbb{N}}}, a_0=0,\) where fn(t) is a forcing term with \(f_n(t)\not = 0\) only for \(n\le n_\star < \infty\) and the coupling coefficients cn satisfy a condition ensuring the formal conservation of energy \(\frac12\sum_n |a_n(t)|^2\) . Despite being formally conservative, we show that these dynamical systems support dissipative solutions (suitably defined) and, as a result, may admit unique (statistical) steady states when the forcing term fn(t) is nonzero. This claim is demonstrated via the complete characterization of the solutions of the system above for specific choices of the coupling coefficients cn. The mechanism of anomalous dissipations is shown to arise via a cascade of the energy towards the modes with higher n; this is responsible for solutions with interesting energy spectra, namely \(\mathbb{E} |a_n|^2\) scales as \(n^{-\alpha}\) as n→∞. Here the exponents α depend on the coupling coefficients cn and \(\mathbb{E}\) denotes expectation with respect to the equilibrium measure. This is reminiscent of the conjectured properties of the solutions of the Navier-Stokes equations in the inviscid limit and their accepted relationship with fully developed turbulence. Hence, these simple models illustrate some of the heuristic ideas that have been advanced to characterize turbulence, similar in that respect to the random passive scalar or random Burgers equation, but even simpler and fully solvable.
Effects of professorial tenure on undergraduate ratings of teaching performance

This study estimates the effect of professorial tenure on undergraduate ratings of learning, instructor quality, and course quality at the University of California, San Diego from Summer 2004 to Spring 2012. During this eight-year period, 120 assistant professors received tenure and 83 associate professors attained full rank. A differences-in-differences model controlling for teaching experience, study hours, response rate, and unobserved heterogeneity among terms, courses, and professors suggests that for a given professor, tenure does not have a significant impact on student ratings of teaching performance, at least in the immediate years after advancement. The results are similar for the promotion from associate to full professor.
An approximate logic for measures

We present a logical framework for formalizing connections between finitary combinatorics and measure theory or ergodic theory that have appeared in various places throughout the literature. We develop the basic syntax and semantics of this logic and give applications, showing that the method can express the classic Furstenberg correspondence and to give short proofs of the Szemeredi Regularity Lemma and the hypergraph removal lemma. We also derive some connections between the modeltheoretic notion of stability and the Gowers uniformity norms from combinatorics.
Effect of Music on Patients Undergoing Colonoscopy: A Meta-Analysis of Randomized Controlled Trials

Purpose Music has been utilized as a therapeutic tool during colonoscopy, but various randomized controlled trials (RCTs) have been inconsistent. We conducted a meta-analysis to analyze the effect of music on patients undergoing colonoscopy. Patients and Methods Multiple medical databases were searched (12/06). Only RCTs on adult subjects that compared music versus no music during colonoscopy were included. Meta-analysis was analyzed for total procedure time, dose of sedative medications (midazolam and mepiridine), and patients’ pain scores, experience, and willingness to repeat the same procedure in the future. Results Eight studies (N = 712) met the inclusion criteria. Patients’ overall experience scores (P < 0.01) were significantly improved with music. No significant differences were noted for patients’ pain scores (P = 0.09), mean doses of midazolam (P = 0.10), mean doses of meperidine (P = 0.23), procedure times (P = 0.06), and willingness to repeat the same procedure in future (P = 0.10). Conclusions Music improves patients’ overall experience with colonoscopy.
The Lyconadins: Enantioselective Total Syntheses of (+)-Lyconadin A and (−)-Lyconadin B

A full account of the enantioselective total syntheses of (+)-lyconadin A (1) and (−)-lyconadin B (2) is presented. Central to this venture was recognition and deployment of a key strategy-level in...
Contextual Control Modes During an Airline Rescheduling Task

This paper examines how humans choose and organize the many activities required in accomplishing tasks in a complex, dynamic environment. These activities include information seeking, communicating, coordinating, judging, decision making, and implementing decisions. A range of contextual control modes (CCMs) as described by Hollnagel--strategic, tactical, opportunistic, and scrambled--are used in this investigation. These CCMs are viewed as responses to contextual features, such as time limits and task demand. The authors specifically examine CCMs during an airline schedule adherence task and evaluate potential measures of these tasks in a controlled experiment using student participants. In the first portion of the experiment, the time limits were varied. In the second, a sudden increase in task demand was introduced. Information-seeking behaviors and participant solutions were recorded. National Aeronautics and Space Administration task load index (TLX) workload ratings and participant self-assessments of contextual control mode were assessed. Participants reported operating in and transitioning between different CCMs in response to time limits and task changes. Results showed that CCMs did not correlate with TLX ratings of demand and effort but did correlate with TLX-frustration and TLX-performance ratings and with time limits. Since similar good performance may be achieved with several CCMs, support systems should be designed to support the behaviors associated with a likely CCM rather than just assuming a strategic CCM.
Systematic Errors of the FSU Global Spectral Model

Abstract Three 20-day winter forecasts have been carried out using the Florida State University Global Spectral Model to examine the systematic errors of the model. Most general circulation models and global forecast models exhibit the same kind of error patterns even though the model formulations vary somewhat between them. Some of the dominant errors are a breakdown of the trade winds in the low latitudes, an overprediction of the subtropical jets accompanied by an upward and poleward shift of the jets, an error in the mean sea level pressure with overintensification of the quasi-stationary oceanic lows and continental highs, and a warming of the tropical mid- and upper troposphere. In this study, a number of sensitivity experiments have been performed for which orography and model physics are considered as possible causes of these errors. A parameterization of the vertical distribution of momentum due to the subgrid scale orography has been implemented in the model to address the model deficiencies ass...
Radioactive Probes of the Supernova-contaminated Solar Nebula: Evidence that the Sun Was Born in a Cluster

We construct a simple model for radioisotopic enrichment of the protosolar nebula by injection from a nearby supernova, based on the inverse square law for ejecta dispersion. In this parameter study, the presolar radioisotopic abundances (i.e., in solar masses) demand a nearby supernova: its distance D can be no larger than 66 times the radius of the protosolar nebula, at a 90% confidence level, assuming 1 M☉ of protosolar material. The relevant size of the nebula depends on its state of evolution at the time of radioactivity injection. In one scenario, a collection of low-mass stars, including our Sun, formed in a group or cluster with a high-mass star that ended its life as a supernova while our Sun was still a protostar, a starless core, or perhaps a diffuse cloud. Using recent observations of protostars to estimate the size of the protosolar nebula constrains the distance of the supernova to D ~ 0.02-1.6 pc. This supernova distance limit is consistent with the scales of low-mass star formation around one or more massive stars, but it is closer than expected were the Sun formed in an isolated, solitary state. Consequently, if any presolar radioactivities originated via supernova injection, we must conclude that our Sun was a member of such a group or cluster that has since dispersed; thus, solar system formation should be understood in this context. The temporal choreography from supernova ejecta to meteorites is important, as the modeled timescale is ≤1.8 Myr. Finally, the model does not distinguish between progenitor masses from 15 to 25 M☉, although the 20 M☉ model is somewhat preferred.
The Weingarten model a la Polyakov

The Weingarten lattice gauge model of Nambu-Goto strings is generalized to allow for fluctuations of an intrinsic worldsheet metric through a dynamical quadrilation. The continuum limit is taken for c≤1 matter, reproducing the results of Hermitian matrix models to all orders in the genus expansion. For the compact c=1 case the vortices are Wilson lines, whose exclusion leads to the theory of non-interacting fermions. As a by-product of the analysis one finds the critical behavior of SOS and vertex models coupled to 2D quantum gravity.
Large-Signal Network Analysis. Overview of the measurement capabilities of a Large-Signal Network Analyzer

This article explains the rationale of performing ?large-signal network analysis? and the basic concepts involved. The focus is on the measurement technology required to perform fully calibrated measurements on nonlinear devices in a versatile environment (different bias, source and load mismatch conditions, continuous wave or modulation). Furthermore this technology is compared to existing approaches. Finally a readily available measurement system is described, which represents the latest developments from Agilent Technologies in the domain of large-signal network analysis.
Transient titanium enolate aldol condensations

Abstract A convenient method is described for the generation and subsequent reaction of a proposed titanium enolate with aromatic aldehydes.
Nash problem for stable toric varieties

The main result of this paper is the proof of the Nash conjecture for stable toric varieties. We also introduce the Nash problem for pairs and prove it in the case of pairs (X, Y) of a toric variety X and a proper closed T -invariant subset Y containing Sing(X) (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Exact N = 2 Landau-Ginzburg flows

Abstract We find exactly solvable N = 2-supersymmetric flows whose infrared fixed point sare the N = 2 minimal models. The exact S -matrices and the Casimir energy (a c -function) are determined along the entire renormalization-group trajectory. The c -functions run from c = 3 (asymptotically) to the N = 2 minimal-model values, leading us to interpret these theories as the Landau-Ginzburg models with superpotential X k +2 . The calculation of the elliptic genus is consistent with this interpretation. We also find an integrable model in this hierarchy with spontaneously broken supersymmetry and superpotential X , and a series of integrable models with (0,2) supersymmetry. The flows exhibit interesting behavior in the UV, including a relation to the N = 2 super sine-Gordon model. We speculate about the relation between the kinetic term and the cigar target-space metric.
Reputation-based trust for a cooperative agent-based backup protection scheme

This paper explores integrating a reputation-based trust mechanism with an agent-based backup protection system to help protect against malicious or byzantine failures. A distributed cooperative trust system has the potential to add an additional layer of protection designed to operate with greater autonomy. This trust component enables the agents in the system to make assessments using an estimate of the trustworthiness of cooperating protection agents based on their responsiveness and the consistency of their responses when compared with their peers. Results illustrate the improved decision-making capability of agents who incorporate this cooperative trust method in the presence of failures in neighboring relays.
Phenomenology of a stabilized modulus

We explore the phenomenology of a stabilized modulus field in the Randall-Sundrum scenario. It is found that if the large separation between branes arises from a small bulk scalar mass then the modulus (i.e. radion) is likely to be lighter than the lowest Kaluza-Klein excitations of bulk fields, and consequently may be the first direct signature of the model. Four-dimensional general covariance completely determines the couplings of the modulus to Standard Model fields. The strength of these couplings is determined by a single parameter which is set by the TeV rather than the Planck scale.
d-Wave superconductivity in doped Mott insulators

Abstract The effect of proximity to a Mott insulating phase on the charge transport properties of a superconductor is determined. An action describing the low energy physics is formulated and different scenarios for the approach to the Mott phase are distinguished by different variation with doping of the parameters in the action. A crucial issue is found to be the doping dependence of the quasiparticle charge which is defined here and which controls the temperature and field dependence of the electromagnetic response functions. Presently available data on high- T c superconductors are analyzed. The data, while neither complete nor entirely consistent, suggest that neither the quasiparticle velocity nor the quasiparticle charge vanish as the Mott phase is approached, in contradiction to the predictions of several widely studied theories of lightly doped Mott insulators. Implications of the results for the structure of vortices in high- T c superconductors are determined.
A new proof of Gromov's theorem on groups of polynomial growth

We give a new proof of Gromov’s theorem that any finitely generated group of polynomial growth has a finite index nilpotent subgroup. The proof does not rely on the MontgomeryZippin-Yamabe structure theory of locally compact groups.
Rate control using spline-interpolated R-D characteristics

Digital video's increased popularity has been driven to an extent by a flurry of recently proposed international standards. In most standards, the rate control scheme, which plays an important role for improving and stabilizing the decoding and play-back quality, is usually not defined. Several techniques have been proposed to aim at the best possible quality for a given channel rate and buffer size. These approaches are complex in that they require the R-D characteristics of the input data to be measured. In this paper, we propose a method to approximate the rate and distortion functions to reduce the complexity of the optimization procedures while making a minimal number of a priori assumptions on the source data. In the proposed method, the R-D of image frames is approximated by spline interpolation functions, and inter-frame dependency (for P or B frames in MPEG) are modelled by a linear-constant function. The application to gradient-based rate-control scheme for MPEG shows that, for a typical MPEG encoder, by using the proposed model, the same performance can be achieved with only about 10 to 15 percent of computation cost.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Imaging protoplanetary disks with a square kilometer array

Abstract The recent detections of extrasolar giant planets has revealed a surprising diversity of planetary system architectures, with many very unlike our Solar System. Understanding the origin of this diversity requires multi-wavelength studies of the structure and evolution of the protoplanetary disks that surround young stars. Radio astronomy and the square kilometer array (SKA) will play a unique role in these studies by imaging thermal dust emission in a representative sample of protoplanetary disks at unprecedented sub-AU scales in the innermost regions, including the “habitable zone” that lies within a few AU of the central stars. Radio observations will probe the evolution of dust grains up to centimeter-sized “pebbles”, the critical first step in assembling giant planet cores and terrestrial planets, through the wavelength dependence of dust emissivity, which provides a diagnostic of particle size. High resolution images of dust emission will show directly mass concentrations and features in disk surface density related to planet building, in particular the radial gaps opened by tidal interactions between planets and disks, and spiral waves driven by embedded protoplanets. Moreover, because orbital timescales are short in the inner disk, synoptic studies over months and years will show proper motions and allow for the tracking of secular changes in disk structure. SKA imaging of protoplanetary disks will reach into the realm of rocky planets for the first time, and they will help clarify the effects of the formation of giant planets on their terrestrial counterparts.
Vibration analysis of heated anisotropic plates with free edge conditions

Tabular and plotted results are presented (as a function of lamination angle and temperature) for the first two vibration frequencies and mode shapes of a heated, single-layer Boron/epoxy laminate. A Ritz formulation is used to determine the thermally induced in-plane forces and the out-of-plane vibration frequencies. This approach is formulated in terms of the out-of-plane displacement and the in-plane stress function; both the displacement and the stress function are expressed as simple algebraic polynomials modified to satisfy the essential boundary conditions. Heating is applied as a steady-state temperature distribution; material properties are considered to be temperature-dependent. To establish the correctness and effectiveness of the method, the in-plane forces are compared with Fourier series analytical results.
Regioselective allene hydroarylation via one-pot allene hydrosilylation/Pd-catalyzed cross-coupling

Advances in hydroarylation have been achieved by the development of a one-pot regioselective allene hydrosilylation/Pd(0)-catalyzed cross-coupling protocol. The regioselectivity is primarily governed by N-heterocyclic carbene (NHC) ligand identity in the hydrosilylation step and is preserved in the subsequent cross-coupling reaction. This methodology affords streamlined access to functionalized 1,1-disubstituted alkenes with excellent regiocontrol.
Anonymity in securities markets

Abstract We analyze how the anonymous trading of uninformed agents affects the characterization of security market equilibrium. We show that the degree of anonymity provided by a market alters the distribution of wealth across agents, the depth of the market, and the incentive agents have to acquire private information about a security's fundamental value. Moreover, the nature of these effects depends on the type of information about uninformed trading that is revealed to market participants. Our results have implications for sunshine trading, dual trading, brokerage relationships, automation and decentralization of markets, and firms' security listing choices. G10, L10.
An arbitrary curvilinear-coordinate method for particle-in-cell modeling

A new approach to kinetic simulation of plasmas in complex geometries, based on the particle-in-cell (PIC) simulation method, is explored. In the two-dimensional (2D) electrostatic version of our method, called the arbitrary curvilinear-coordinate PIC method, all essential PIC operations are carried out in 2D on a uniform grid on the unit square logical domain, and mapped to a nonuniform boundary-fitted grid on the physical domain. As the resulting logical grid equations of motion are not separable, we have developed an extension of the semi-implicit modified leapfrog integration technique to preserve the symplectic nature of the logical grid particle mover. A generalized, curvilinear-coordinate formulation of Poisson's equations to solve for the electrostatic fields on the uniform logical grid is also developed. By our formulation, we compute the plasma charge density on the logical grid based on the particles' positions on the logical domain. That is, the plasma particles are weighted to the uniform logical grid and the self-consistent mean electrostatic fields obtained from the solution of the logical grid Poisson equation are interpolated to the particle positions on the logical grid. This process eliminates the complexity associated with the weighting and interpolation processes on the nonuniform physical grid and allows us to run the PIC method on arbitrary boundary-fitted meshes.
On the choice of subgoals for learning control systems

A subgoal problem is defined as the problem of choosing a subgoal or on-line performance evaluator compatible with reinforcement-type learning control systems. The subgoal must evaluate each control decision separately and direct the learning process toward the optimum with respect to the primary goal or performance index. Analytical results are presented for an unconstrained control, including an M-decision evaluator. This general subgoal fails to satisfy the conditions of per-decision evaluation except when M is 1, but might prove useful with different learning algorithms. A method is presented for "doing the best with what you have." That is, a priori information might be used either to design a fixed controller or to choose the subgoal for a learning controller. Analytical and experimental results demonstrate that as a general rule the learning controller makes the best use of the a priori knowledge.
High-precision thermodynamics and Hagedorn density of states

We compute the entropy density of the confined phase of QCD without quarks on the lattice to very high accuracy. The results are compared to the entropy density of free glueballs, where we include all the known glueball states below the two-particle threshold. We find that an excellent, parameter-free description of the entropy density between $0.7{T}_{c}$ and ${T}_{c}$ is obtained by extending the spectrum with the exponential spectrum of the closed bosonic string.
Nepotism, incentives and the academic success of college students

Abstract This study investigates the role of parent-owned businesses on children's college success and post-college aspirations by using a unique data set from a private university in Turkey. The data set matches college students' administrative records with survey responses. The presence of self-employed parents and family businesses has a strong negative association with college success even after accounting for observed ability, parental background, and various individual characteristics. An explanation for the lower GPAs of the children of self-employed parents is that in the presence of parent-owned businesses students have a larger set of post-graduation options and are more likely to plan on becoming self-employed due to intergenerational transfer of self-employment. Hence, these students may not exert as much effort in acquiring the task-specific career-oriented human capital taught in college. In line with expectations, we find that the children of self-employed parents are more likely to have entrepreneurial intent and are less likely to plan to attend graduate school.
Effect of Surface Roughness on Film Cooling Performance

Etude experimentale par la technique du transfert de masse. On etudie deux geometries d'injection et 6 types de rugosite. Etude de l'influence du type de rugosite sur l'efficacite moyenne et sur l'uniformite laterale de l'efficacite
VERY LARGE ARRAY DETECTION OF THE 36 GHz ZEEMAN EFFECT IN DR21W REVISITED

We report on the observation of the 36 GHz methanol maser line in the star-forming region DR21W to accurately measure the Zeeman effect. The Zeeman signature reported by Fish et al. became suspicious after an instrumental effect was discovered in the early days of the commissioning of the Very Large Array Wide-band Digital Architecture correlator. We conclude that the previously reported magnetic field strength of 58 mG (1.7 Hz mG–1/z) is instrumental in nature and thus incorrect. With the improved performance of the array, we now deduce a 3σ limit of –4.7 to +0.4 mG (1.7 Hz mG–1/z) for the line-of-sight component of the magnetic field strength in DR21W.
Economic implications of thermal energy storage for concentrated solar thermal power

Abstract Solar energy is an attractive renewable energy source because the sun's energy is plentiful and carbon-free. However, solar energy is intermittent and not suitable for base load electricity generation without an energy backup system. Concentrated solar power (CSP) is unique among other renewable energy options because it can approach base load generation with molten salt thermal energy storage (TES). This paper describes the development of an engineering economic model that directly compares the performance, cost, and profit of a 110-MW parabolic trough CSP plant operating with a TES system, natural gas-fired backup system, and no backup system. Model results are presented for 0–12 h backup capacities with and without current U.S. subsidies. TES increased the annual capacity factor from around 30% with no backup to up to 55% with 12 h of storage when the solar field area was selected to provide the lowest levelized cost of energy (LCOE). Using TES instead of a natural gas-fired heat transfer fluid heater (NG) increased total plant capital costs but decreased annual operation and maintenance costs. These three effects led to an increase in the LCOE for PT plants with TES and NG backup compared with no backup. LCOE increased with increasing backup capacity for plants with TES and NG backup. For small backup capacities (1–4 h), plants with TES had slightly lower LCOE values than plants with NG backup. For larger backup capacities (5–12 h), plants with TES had slightly higher LCOE values than plants with NG backup. At these costs, current U.S. federal tax incentives were not sufficient to make PT profitable in a market with variable electricity pricing. Current U.S. incentives combined with a fixed electricity price of $200/MWh made PT plants with larger backup capacities more profitable than PT plants with no backup or with smaller backup capacities. In the absence of incentives, a carbon price of $100–$160/tonne CO2eq would be required for these PT plants to compete with new coal-fired power plants in the U.S. If the long-term goal is to increase renewable base load electricity generation, additional incentives are needed to encourage new CSP plants to use thermal energy storage in the U.S.
A neural network for locating the primary vertex in a pixel detector

Abstract Using simulated collider data for p + p → 2Jets interactions in a two-barrel pixel detector, a neural network is trained to construct the coordinate of the primary vertex to a high degree of accuracy. Three other estimates of this coordinate are also considered and compared to that of the neural network. It is shown that the network can match the best of the traditional estimates.
Extreme-scale computer architecture: energy efficiency from the ground up

As we move to integration levels of 1,000-core processor chips, it is clear that energy and power consumption are the most formidable obstacles. To construct such a chip, we need to rethink the whole compute stack from the ground up for energy efficiency --- and attain Extreme-Scale Computing. First of all, we want to operate at low voltage, since this is the point of maximum energy efficiency. Unfortunately, in such an environment, we have to tackle substantial process variation. Hence, it is important to design efficient voltage regulation, so that each region of the chip can operate at the most efficient voltage and frequency point. At the architecture level, we require simple cores organized in a hierarchy of clusters. Moreover, we also need techniques to reduce the leakage of on-chip memories and to lower the voltage guardbands of logic. Finally, data movement should be minimized, through both hardware and software techniques. With a systematic approach that cuts across multiple layers of the computing stack, we can deliver the required energy efficiencies.
A three-parameter elastic foundation model for interface stresses in curved beams externally strengthened by a thin FRP plate

Abstract Externally bonding of fiber reinforced polymer (FRP) plates or sheets has become a popular method for strengthening reinforced concrete structures. Stresses along the FRP–concrete interface are of great importance to the effectiveness of this type of strengthening because high stress concentration along the FRP–concrete interface can lead to the FRP debonding from the concrete beam. In this study, we develop an analytical solution of interface stresses in a curved structural beam bonded with a thin plate. A novel three-parameter elastic foundation model is used to describe the behavior of the adhesive layer. This adhesive layer model is an extension of the two-parameter elastic foundation commonly used in existing studies. It assumes that the shear stress in the adhesive layer is constant through the thickness, and the interface normal stresses along two concrete/adhesive and adhesive/FRP interfaces are different. Closed-form solutions are obtained for these two interfacial normal stresses, shear stress within the adhesive layer, and beam forces. The validation of these solutions is confirmed by finite element analysis.