cssi/SciSciGPT-SciSciNet huggingface dataset:
A Definitive Measurement of Time Dilation in the Spectral Evolution of the Moderate-Redshift Type Ia Supernova 1997ex

We have obtained high-quality Keck optical spectra at three epochs of the Type Ia supernova 1997ex, whose redshift z is 0.361. The elapsed calendar time between the first two spectra was 24.88 days, and that between the first and third spectra was 30.95 days. In an expanding universe where 1 + z represents the factor by which space has expanded between the emission and detection of light, the amount of aging in the supernova rest frame should be a factor of 1/(1 + z) smaller than the observed-frame aging; thus, we expect SN 1997ex to have aged 18.28 and 22.74 days between the first epoch and the second and third epochs, respectively. The quantitative method for determining the spectral-feature age of an SN Ia reveals that the corresponding elapsed times in the supernova rest frame were 16.97 ± 2.75 and 18.01 ± 3.14 days, respectively. This result is inconsistent with no time dilation with a significance level of 99.0%, providing evidence against "tired light" and other hypotheses in which no time dilation is expected. Moreover, the observed timescale of spectral evolution is inconsistent with that expected in the "variable mass theory." The result is within ~1 σ of the aging expected from a universe in which redshift is produced by cosmic expansion.
Inflow-Outflow Model with Conduction and Self-Consistent Feeding for Sgr A*

We propose a two-temperature radial inow-outow model near Sgr A* with self-consistent feeding and conduction. Stellar winds from individual stars are considered to nd the rates of mass injection and energy injection. These source terms help to partially eliminate the boundary conditions on the inow. Electron thermal conduction is crucial for inhibiting the accretion. Energy diuses out from several gravitational radii, unbinding more gas at several arcseconds and limiting the accretion rate to < 1% of Bondi rate. We successfully t the X-Ray surface brightness prole found from the extensive Chandra observations and reveal the X-Ray point source in the center. The super-resolution technique allows us to infer the presence and estimate the unabsorbed luminosity L 4 10 32 erg s 1 of the point source. The employed relativistic heat capacity and direct heating of electrons naturally lead to low electron temperature Te 4 10 10 K near the black hole. Within the same model we t 86 GHz optically thick emission and obtain the order of magnitude agreement of Faraday rotation measure, thus achieving a single accretion model suitable at all radii. Subject headings: accretion, accretion disks | conduction | Galaxy: center | stars: winds, outows
Drag in paired electron-hole layers.

We investigate transresistance effects in electron-hole double-layer systems with a superfluid electron-hole condensate. Our theory is based on the use of a minimum dissipation premise to fix the current carried by the condensate. We find that the drag resistance jumps discontinuously at the condensation temperature and diverges as the temperature approaches zero.
Entropy of contracting universe in cyclic cosmology

Following up a recent proposal1 for a cyclic model based on phantom dark energy, we examine the content of the contracting universe (cu) and its entropy Scu. We find that beyond dark energy, the universe contains on average zero or an unlikely single photon which if present immediately after turnaround would have infinitesimal energy that blue shifts eventually to produce e+e- pairs. These statements are independent of the equation of state ω = p/ρ of dark energy provided ω < -1. Thus Scu = 0 and if observations confirm ω < -1, the entropy problem is solved. We discuss the absence of a theoretical lower bound on ϕ = |ω+1|, then describe an anthropic fine tuning argument that renders unlikely extremely small ϕ. The present bound ϕ ≲ 0.1 already implies a time until turnaround of (tT - t0) ≳ 100 Gy.
Truth and Memory: Linking Instantaneous and Retrospective Self-Reported Cigarette Consumption

Studies of smoking behavior commonly use the time-line follow-back (TLFB) method, or periodic retrospective recall, to gather data on daily cigarette consumption. TLFB is considered adequate for identifying periods of abstinence and lapse but not for measurement of daily cigarette consumption, thanks to substantial recall and digit preference biases. With the development of the hand-held electronic diary (ED), it has become possible to collect cigarette consumption data using ecological momentary assessment (EMA), or the instantaneous recording of each cigarette as it is smoked. EMA data, because they do not rely on retrospective recall, are thought to more accurately measure cigarette consumption. In this article we present an analysis of consumption data collected simultaneously by both methods from 236 active smokers in the pre-quit phase of a smoking cessation study. We define a statistical model that describes the genesis of the TLFB records as a two-stage process of mis-remembering and rounding, including fixed and random effects at each stage. We use Bayesian methods to estimate the model, and we evaluate its adequacy by studying histograms of imputed values of the latent remembered cigarette count. Our analysis suggests that both mis-remembering and heaping contribute substantially to the distortion of self-reported cigarette counts. Higher nicotine dependence, white ethnicity and male sex are associated with greater remembered smoking given the EMA count. The model is potentially useful in other applications where it is desirable to understand the process by which subjects remember and report true observations.
The Productivity of Working Hours

Observations on munition workers, most of them women, are organised to examine the relationship between their output and their working hours. The relationship is non-linear: below an hour's threshold, output is proportional to hours; above a threshold, output rises at a decreasing rate as hours increase. Implications of this finding for the estimation of labour supply functions are considered. The findings also link up with the current research on the effects of long working hours on accidents and injuries.
Non-analytic magnetic field dependence of quasi-particle properties of two-dimensional metals

We show that in a weak external magnetic field H the quasi-particle residue and the renormalized electron Lande factor of two-dimensional Fermi liquids exhibit a non-analytic magnetic field dependence proportional to | H | which is due to electron-electron interactions and the Zeeman effect. We explicitly calculate the corresponding prefactors to second order in the interaction and show that they are determined by low-energy scattering processes involving only momenta close to the Fermi surface. These non-analytic terms appear in measurable quantities such as the density of states and the magnetoconductivity.
Application of motion-compensated prediction to coding ultrasound video

ABSTRACT B-mode ultrasound video is a very effective diagnostic modality. Popular image sequence coding techniquesbased on motion compensation such as MPEG and H.263 give poor results when applied to ultrasound video,because of the noisy nature of the signal. By using motion compensation in conjunction with a model-based ultrasound representation, we improve the quality of reconstructed images significantly. Keywords: telemedicine, ultrasound, video coding, motion compensation. 1 INTRODUCTION Telemedicine is a relatively new area in which digital signal processing is making inroads. Advances in thisarea can have great impact on the quality of health care throughout the world. Within this general field, weconsider the problem of transmitting in real time digital ultrasound video of the heart at low bit rates over con-ventional telephone and ISDN lines—a problem we are investigating with the Medical college of Georgia. Froma health care perspective, this is important because it allows rural hospitals (of which most do NOT employ a
An Enantioselective Synthesis of cis‐4‐tert‐Butoxycarbamoyl‐1‐methoxycarbonyl‐2‐cyclopentene—A Useful, General Building Block

The amino acid derivative in the title represents an important building block for the synthesis of a number of biologically important targets such as the antiviral carbanucleosides and amidinomycin. By using asymmetric palladium-catalyzed desymmetrization of meso-2-ene-1,4-diols, cis-1,4-dibenzoyloxy-2-cyclopentene can be converted to the enantiomerically pure title compound in only four steps. Chemoselective ester reduction allows entry into the domain of carbanucleosides, whereas double-bond reduction provides the precursor for amidinomycin. In an ancillary study, a facile diastereoselective cis-hydroxylation provides aminocyclopentitols, compounds that have proven to be potent glycosidase inhibitors.
Additives in rubber processing

Abstract This paper reviews the different classes of processing aids and disfcusses a concept which rationalizes their behaviour, differentiating between products acting as external and as internal lubricants. Capillary rheometry can be used to demonstrate differences between these modes of action in relation to viscosity and to extrudate swell. Laboratory testing has shown liquid natural rubbers to be the most effective bulk-viscosity modifiers. Information of this type can assist the compounder in short-listing the number of formulations necessary for factory trials in relation to both processing characteristics and final performance.
Approximation Algorithms for Wavelet Transform Coding of Data Streams

This paper addresses the problem of finding a B-term wavelet representation of a given discrete function fepsiRn whose distance from is minimized. The problem is well understood when we seek to minimize the Euclidean distance between f and its representation. The first-known algorithms for finding provably approximate representations minimizing general lp distances (including linfin) under a wide variety of compactly supported wavelet bases are presented in this paper. For the Haar basis, a polynomial time approximation scheme is demonstrated. These algorithms are applicable in the one-pass sublinear-space data stream model of computation. They generalize naturally to multiple dimensions and weighted norms. A universal representation that provides a provable approximation guarantee under all mu-norms simultaneously; and the first approximation algorithms for bit-budget versions of the problem, known as adaptive quantization, are also presented. Further, it is shown that the algorithms presented here can be used to select a basis from a tree-structured dictionary of bases and find a B-term representation of the given function that provably approximates its best dictionary-basis representation.
NEW CYCLIC AND POLYMERIC PHOSPHAZENES DERIVED FROM N-SILYLPHOSPHORANIMINES

Silicon-nitrogen-phosphorus compounds of the type Me 3 SiN═PR(R′)X(X= Cl, Br, OCH2CF 3 , OPh), known as N-silylphosphoranimines,are useful precursors to both cyclic and polymeric phosphazenes.Depending on the leaving group (X), thermolysis reactions afford either cyclic trimers, [N═PR(R′)] 3 (when X = Cl, Br), or linear polymers,[N═PR(R′)]n (when X = OCH 2 CF 3 or OPh). Treatment of the P-trifluoroethoxy and P-phenoxy derivatives, Me 3 SiN═PR(R′)X (X = OCH 2 CF 3 , OPh), with alcohols at lower temperature usually results in the formation of cyclic phosphazene trimers via silyl ether elimination. Recently, we have applied these synthetic methods to the preparation of some new phosphazene systems including a series of 4-aryl-functionalized trimers and polymers and a variety of non-geminal, mixed-substituent cyclic trimers. Representative examples of the synthesis, structural characterization, and reactivity of these new phosphazenes and their Si─N─P precursors are reported here.
Evolutionary multiobjective optimization in water resources: The past, present, and future

Abstract This study contributes a rigorous diagnostic assessment of state-of-the-art multiobjective evolutionary algorithms (MOEAs) and highlights key advances that the water resources field can exploit to better discover the critical tradeoffs constraining our systems. This study provides the most comprehensive diagnostic assessment of MOEAs for water resources to date, exploiting more than 100,000 MOEA runs and trillions of design evaluations. The diagnostic assessment measures the effectiveness, efficiency, reliability, and controllability of ten benchmark MOEAs for a representative suite of water resources applications addressing rainfall–runoff calibration, long-term groundwater monitoring (LTM), and risk-based water supply portfolio planning. The suite of problems encompasses a range of challenging problem properties including (1) many-objective formulations with four or more objectives, (2) multi-modality (or false optima), (3) nonlinearity, (4) discreteness, (5) severe constraints, (6) stochastic objectives, and (7) non-separability (also called epistasis). The applications are representative of the dominant problem classes that have shaped the history of MOEAs in water resources and that will be dominant foci in the future. Recommendations are given for the new algorithms that should serve as the benchmarks for innovations in the water resources literature. The future of MOEAs in water resources needs to emphasize self-adaptive search, new technologies for visualizing tradeoffs, and the next generation of computing technologies.
Random-Time Aggregation in Partial Adjustment Models

How is econometric analysis (of partial adjustment models) affected by the fact that, although data collection is done at regular, fixed intervals of time, economic decisions are made at random intervals of time? This article addresses this question by modeling the economic decision-making process as a general point process. Under random-time aggregation, (1) inference on the speed of adjustment is biased—adjustments are a function of the intensity of the point process and the proportion of adjustment—(2) inference on the correlation with exogenous variables is generally downward biased, and (3) a nonconstant intensity of the point process gives rise to a general class of regime-dependent time series models. An empirical application to test the production-smoothing-buffer-stock model of inventory behavior illustrates, in practice, the effects of random-time aggregation.
Structure of layered crystals studied by high energy ion beams

Abstract This paper reviews the use of MeV ion channeling techniques for the characterization of heteroepitaxial strained-layer structures. We present new results for the analysis of semiconductor surface layers and buried layers, and review previous results for strained-layer superlattices. Three inclined-direction channeling approaches are discussed: angular scans to measure the strain in the upper layers, axial and planar dechanneling as a function of depth to provide a depth-resolved monitor of the strain, and catastrophic dechanneling in planes to measure small strains in superlattices. Along the growth direction dechanneling by misfit dislocations is used to monitor strain relief.
Corporate self renewal

Abstract In this article President Haggerty of Texas Instruments discusses the problem: How can an organization become older and yet stay flexible and adaptable. He explains how at Texas Instruments he has tried to develop a system or framework within which continuous innovation, renewal and rebirth can occur. The system involves innovation in research and development, in production and in marketing, and means that “at Texas Instruments, the long range planning system is fundamentally a system for managing innovation”. The inception of formal planning to identify and state succinctly in writing the strategies required for growth and development, has produced a sizable increase in the production of Major Impact Strategies with a potential pay-off of $50 million net sales over five years.
Tight binding prediction of the α-Gd2S3 magnetic structure

Abstract Spin-dependent extended Huckel tight binding (EHTB) calculations were carried out for the magnetic solid Gd 2 S 3 by considering 20 different variations in the ordering of the 4 f 7 moments. The tight-binding calculations are used to interpolate the band structure of a nonmagnetic congener (Y 2 S 3 ) and the 4 f /5 d ,6 s exchange interactions are introduced as perturbations via the introduction of spin-dependent H dd and H ss parameters. The calculations predict that Gd 2 S 3 adopts an antiferromagnetic ordering of the 4 f 7 moments that is consistent with published neutron diffraction results. Our attempt to account for the calculated energies of the spin patterns using an Ising model was unsuccessful.
Highly Selective Room-Temperature Copper-Catalyzed C−N Coupling Reactions

Through the use of cyclic beta-diketones as supporting ligands, the copper-catalyzed coupling of aryl iodides with aliphatic amines occurs at room temperature in as little as 1 h. These high reaction rates allow for the coupling of a wide range of aryl and heteroaryl iodides at room temperature. This method is highly tolerant of a number of reactive functional groups, including -Br and aromatic -NH2 as well as phenolic and aliphatic -OH. The high selectivity of the CuI-beta-diketone catalyst for aliphatic amines represents a useful complement to the palladium-based methods.
Unstable Waves of Jet Flows With Density Inhomogeneity

Abstract : The problem to be considered concerns linear unstable waves of axisymmetric jet flows in the presence of density inhomogeneities. Such flow phenomena occur when a jet is discharged into a stratified medium, e.g., pollutants and industrial waste discharged into the environment, cooling water discharged from power plants into rivers and lakes, and flow patterns generated by vehicles moving in the ocean. Investigating the instability characteristics of the flow can mean controlling the flow-patterns, for example, produced by vehicles moving in the ocean. As in the case of two-dimensional shear flows, axisymmetric jet flows may possess amplified waves due to the Kelvin-Helmhholtz mechanism except that the formulation for jet flows is complicated by the absence of the Squire transformation and the consideration of cylindrical geometry. Keywords: Jet flow, Fluid mechanics, Waste water, Effluvia, Power plants, Waste disposal.
Multi-rate analysis and design of visual feedback digital servo-control system

This paper addresses the analysis and design of digital motion control system with machine vision as a feedback measurement in the servo loop. The camera vision is modeled as a discrete time-delayed sensor. A multirate formulation is proposed based on the fact that vision update rate is slower than the digital servo-control update rate and is analyzed through the lifting technique which converts the periodic time varying multirate system to a time invariant one. Some interesting properties of this specific multirate system are found and are utilized in control system design. An l-1 norm optimal control problem is formulated to minimize the maximum time domain error, which has direct connection to camera field of view and mechanical tolerance
Wall-crossing, Toric divisor and Seiberg duality

We study the wall-crossing phenomena of BPS D4-D2-D0 states on the conifold and orbifold $ {{{{{\mathbb{C}}^2}}} \left/ {{{{\mathbb{Z}}_2}}} \right.} $ , from the viewpoint of the quiver quantum mechanics on the D-branes. The Kahler moduli dependence of the BPS index is translated into the FI parameter dependence of the Witten index. The wall-crossing phenomena are related to the Seiberg dualities of the quiver quantum mechanics. All the differences from the D6-D2-D0 case arise from the additional superpotential and “anti-quark” induced by the D4-brane. When the D-branes are on the conifold, the flop transition changes the duality cascade. When the D-branes are on the orbifold $ {{{{{\mathbb{C}}^2}}} \left/ {{{{\mathbb{Z}}_2}}} \right.} $ , the generating function of the Witten index is always given by a character of the affine SU(2) algebra. Both are consistent with the wall-crossing formula for BPS indices.
Kinetic regimes and cross-over times in many-particle reacting systems

We study kinetics of single-species reactions ("A + A → ∅") for general local reactivity Q and dynamical exponent z (rms displacement xt ~ t1/z.) For small molecules z = 2, whilst z = 4,8 for certain polymer systems. For dimensions d above the critical value dc = z, kinetics are always mean field (MF). Below dc, the density nt initially follows MF decay, n0 − nt ~ n02Qt. A 2-body diffusion-controlled regime follows for strongly reactive systems (Q > Q* ~ n0(z − d)/d) with n0 − nt ≈ n02xtd. For Q < Q*, MF kinetics persist, with nt ~ 1/Qt. In all cases nt ≈ 1/xtd at the longest times. Our analysis avoids decoupling approximations by instead postulating weak physically motivated bounds on correlation functions.
Stochastic current switching in bistable resonant tunneling systems

Current-voltage characteristics of resonant-tunneling structures often exhibit intrinsic bistabilities. In the bistable region of the I-V curve one of the two current states is metastable. The system switches from the metastable state to the stable one at a random moment in time. The mean switching time t depends exponentially on the bias measured from the boundary of the bistable region Vth. We find full expressions for t sincluding prefactorsd as functions of bias, sample geometry, and in-plane conductivity. Our results take universal form upon appropriate renormalization of the threshold voltage Vth. We also show that in large samples the switching initiates inside, at the edge, or at a corner of the sample depending on the parameters of the system.
Pulsed laser treatment of plasma sprayed coatings

A pulsed CO2-TEA laser was used to melt the surface of plasma-sprayed coatings. An analysis of the laser parameters on the heat transfer is made: the melt depth and the surface temperature were calculated for different laser inputs. It was found that the pulse length must be in the range of 20 to 40 µ s in order to fill up the pores of the coating and to keep the surface temperature below the boiling range. Experimental results on surface modification are explained in terms of power density.
The Rights of the Guilty Punishment and Political Legitimacy

In this essay I develop and defend a theory of state punishment within a wider conception of political legitimacy. While many moral theories of punishment focus on what is deserved by criminals, I theorize punishment within the specific context of the state's relationship to its citizens. Central to my account is Rawls's “liberal principle of legitimacy,” which requires that all state coercion be justifiable to all citizens. I extend this idea to the justification of political coercion to criminals qua citizens. I argue that the liberal principle of legitimacy implicitly requires states to respect the basic political rights of those who are guilty of committing crimes, thus prohibiting capital punishment.
The effect of the Asian financial crisis on the performance of Korean nationwide banks

The Asian financial crisis spread its effect quickly across a number of countries. Korea faced serious problems in her financial and corporate sectors. This study considers the performance of Korean nationwide banks before and immediately after the Asian financial crisis. The performance of Korean nationwide banks took a big hit in 1998. Most banks recovered somewhat in 1999 with the notable exception of the further deterioration of Seoul. Several factors possess strong correlations with bank performance. Among other standard findings, equity to assets correlates positively with bank performance, even when the government recapitalized a number of institutions that performed poorly. The Asian crisis did not affect the normal rules of good bank management. The government, however, directly intervened in the banking sector on a large scale to limit the scope of the crisis in the Korean economy.
Verifying programs by algebraic and logical reduction

Methods for verifying programs written in a higher level programming language are devised and implemented. The system can verify programs written in a subset of PASCAL, which may have data structures such as ARRAY, POINTER, and RECORD and control structures such as WHILE, REPEAT, FOR, PROCEDURE, FUNCTION and COROUTINE. The process of creation of verification conditions is an extension of the work done by lgarashi, London and Luckham (1972) which is based on the deductive theory by Hoare (1969). Verification conditions are proved using specialized simplification and proof techniques, which consist of an arithmetic simplifier, equality replacement rules, fast algorithm for simplifying formulas using propositional truth value evaluation, and a depth first proof search process. The basis of deduction mechanism used in this prover is Gentzen-type formal system. Several sorting programs including Floyd's TREESORT3 and Hoare's FIND are verified. It is shown that the resulting array is not only ordered but also a permutation of the input arrayThis research was supported in part by the Advanced Research Projects Agency of the Office of the Secretary of Defence under contract DAHC 15-73-C-0435.
BROADCASTING IN AD HOC NETWORKS BASED ON SELF-PRUNING

We propose a general framework for broadcasting in ad hoc networks through self-pruning. The approach is based on selecting a small subset of hosts (also called nodes) to form a forward node set on carry out a broadcast process. Each node, upon receiving a broadcast packet, determines whether to forward the packet or not based on two neighborhood coverage conditions proposed in this paper. These coverage conditions depend on neighbor connectivity and history of visited nodes, and in general, resort to global network information. Using local information such as k-hop neighborhood information, the forward node set is selected through a distributed and local pruning process. The forward node set can be constructed and maintained through either a proactive process (i.e., "up-to-date") or a reactive process (i.e., "on-the-fly"). Several existing broadcast algorithms can be viewed as special cases of the coverage conditions with k-hop neighborhood information. Simulation results show that new algorithms, which are more efficient than existing ones, can be derived from the coverage conditions, and self-pruning based on 2- or 3-hop neighborhood information is relatively more cost-effective.
An Analysis of Regional Economic Growth in the U.S. Midwest

In this paper, we examine more closely some of the forces that underlie economic growth at the county level. In an effort to describe a much more comprehensive regional economic growth model, we address a variety of different hypotheses by introducing a large number of growth-related variables. When formulating our hypotheses and specifying our growth model, we make liberal use of geographic mapping software to describe the data so as to “paint” a picture of where growth spots exist. Our empirical estimation indicates amenities, state and local tax burdens, population density, amount of primary agriculture activity, and demographics have important impacts on economic growth.
ABR Core examination preparation: results of a survey of fourth-year radiology residents who took the 2013 examination.

Rationale and Objectives A survey was administered to fourth-year radiology residents after receiving their results from the first American Board of Radiology (ABR) Core examination in 2013. The purpose was to gather information regarding resources and study strategies to share with program directors and future resident classes. Materials and Methods An online survey was distributed to examinees nationwide. The survey included free-response and multiple choice questions that covered examination results, perceived value of enumerated study resources, case-based and didactic teaching conferences, board reviews, study materials for noninterpretive skills, multidisciplinary conference attendance, and free-form comments. Results Two hundred sixty-six of 1186 residents who took the Core examination responded to the survey. Some resources demonstrated a significant difference in perceived value between residents who passed the examination and residents who failed, including internal board reviews (1.10, P Conclusions Radiology residents and residency programs have adapted their preparations for the ABR Core examination in a variety of ways. Certain practices and study tools, including daily conferences and internal board reviews, had greater perceived value by residents who passed the examination than by residents who failed. This survey provides insights that can be used to assess and modify current preparation strategies for the ABR Core examination.
Bankers, Industrialists, and their Cliques: Elite Networks in Mexico and Brazil during Early Industrialization

The historiographies of Mexico and Brazil have implicitly stated that business networks were crucial for the initial industrialization of these two countries. Recently, differing visions on the importance of business networks have arisen. In the case of Mexico, the literature argues that entrepreneurs relied heavily on an informal institutional structure to obtain necessary resources and information. In contrast, the recent historiography of Brazil suggests that after 1890 the network of corporate relations became less important for entrepreneurs trying to obtain capital and concessions, once the institutions promoted financial markets and easy entry for new businesses. Did entrepreneurs in Brazil and Mexico organize their networks differently to deal with the different institutional settings? We examine whether in Mexico businessmen relied more on networks of interlocking boards of directors and other informal arrangements to do business than in Brazil. Our hypothesis is confirmed by three related results: (1) the total number of connections (i.e., the density of the network) was higher in Mexico than Brazil; (2) in Mexico, there was one dense core network, while in Brazil we find fairly dispersed clusters of corporate board interlocks; and most importantly, (3) politicians played a more important role in the Mexican network of corporate directors than their counterparts in Brazil. Interestingly, even though Brazil and Mexico relied on very different institutional structures, both countries had similar rates of growth between 1890 and 1913. However, the dense and exclusive Mexican network might have ended up increasing the social and political tensions that led to the Mexican Revolution (1910–1920).
On the complementarity of F-theory, orientifolds, and heterotic strings

Abstract We study F-theory duals of six-dimensional heterotic vacua in extreme regions of moduli space where the heterotic string is very strongly coupled. We demonstrate how to use orientifold limits of these F-theory duals to regain a perturbative string description. As an example, we reproduce the spectrum of a T 4 / Z 4 orientifold as an F-theory vacuum with a singular K3 fibration. We relate this vacuum to previously studied heterotic E8 × E8 compactifications on K3.
Error bounds in the averaging of hybrid systems

The authors analyze the error introduced by the averaging of hybrid systems. These systems involve linear systems which can take a number of different realizations based on the state of an underlying finite state process. The averaging technique (based on a formula from Lie algebras known as the Backer-Campbell-Hausdorff (BCH) formula) provides a single system matrix as an approximation to the hybrid system. The two errors discussed are: (1) the error induced by the truncation of the BCH series expansion and (2) the error between the actual hybrid system and its average. A simple sufficient stability test is proposed to check the asymptotic behavior of this error. In addition, conditions are derived that allow the use of state feedback instead of averaging to arrive at a time-invariant system matrix. >
Evolving a Roving Eye for Go

Go remains a challenge for artificial intelligence. Currently, most machine learning methods tackle Go by playing on a specific fixed board size, usually smaller than the standard 19×19 board of the complete game. Because such techniques are designed to process only one board size, the knowledge gained through experience cannot be applied on larger boards. In this paper, a roving eye neural network is evolved to solve this problem. The network has a small input field that can scan boards of any size. Experiments demonstrate that (1) The same roving eye architecture can play on different board sizes, and (2) experience gained by playing on a small board provides an advantage for further learning on a larger board. These results suggest a potentially powerful new methodology for computer Go: It may be possible to scale up by learning on incrementally larger boards, each time building on knowledge acquired on the prior board.
Representative Bureaucracy, Ethnicity, and Public Schools Examining the Link Between Representation and Performance

Demographic changes in the United States have led to challenges for public organizations that are tasked to serve shifting target populations. Many arguments exist for including greater numbers of ...
Two-Way Coupled Fluid Structure Interaction Simulation of a Propeller Turbine

During the operation of a hydro turbine the fluid mechanical pressure loading on the turbine blades provides the driving torque on the turbine shaft. This fluid loading results in a structural load on the component which in turn causes the turbine blade to deflect. Classically, these mechanical stresses and deflections are calculated by means of finite element analysis (FEA) which applies the pressure distribution on the blade surface calculated by computational fluid dynamics (CFD) as a major boundary condition. Such an approach can be seen as a one-way coupled simulation of the fluid structure interaction (FSI) problem. In this analysis the reverse influence of the deformation on the fluid is generally neglected. Especially in axial machines the blade deformation can result in a significant impact on the turbine performance. The present paper analyzes this influence by means of fully two-way coupled FSI simulations of a propeller turbine utilizing two different approaches. The configuration has been simulated by coupling the two commercial solvers ANSYS CFX for the fluid mechanical simulation with ANSYS Classic for the structure mechanical simulation. A detailed comparison of the results for various blade stiffness by means of changing Young`s Modulus are presented. The influence of the blade deformation on the runner discharge and performance will be discussed and shows for the configuration investigated no significant influence under normal structural conditions. This study also highlights that a two-way coupled fluid structure interaction simulation of a real engineering configuration is still a challenging task for today`s commercially available simulation tools.
The Arc-Weighted Version of the Second Neighborhood Conjecture

Seymour conjectured that every oriented simple graph contains a vertex whose second neighborhood is at least as large as its first. Seymour's conjecture has been verified in several special cases, most notably for tournaments by Fisheri��. One extension of the conjecture that has been used by several researchers is to consider vertex-weighted digraphs. In this article we introduce a version of the conjecture for arc-weighted digraphs. We prove the conjecture in the special case of arc-weighted tournaments, strengthening Fisher's theorem. Our proof does not rely on Fisher's result, and thus can be seen as an alternate proof of said theorem.
Limiting nature of continuum generation in silicon

The generation of spectral continuum in silicon is studied experimentally and theoretically. The dynamics of the free carriers generated through two photon absorption (TPA) is found to limit the extent of the generated continuum.
Synthesis of the putative l-arginine metabolite L-NG-hydroxyarginine

Abstract Syntheses of L-NG-hydroxyarginine (1), the putative biosynthetic precursor of nitric oxide, and the 15N labelled analogs 9 and 10 using L-ornithine as the enantiopure starting material is reported.
Cerium (III) chloride mediated nitrile aldol reactions: Enhanced diastereoselectivities using a chiral organocerium complex

Abstract The addition of anhydrous cerium chloride to nitrile aldol reactions has been found to provide high yields of β-hydroxynitriles. Also, the aldol reaction of α,β-unsaturated carbonyl compounds with nitrile enolates in the presence of cerium chloride affords 1, 2 addition exclusively in good to excellent yields. The organocerium complexes of R-(+)-1,1′-bi-2-naphthol have successfully mediated the aldol addition of lithio alkyl and arylacetonitriles to aldehydes, and the reaction gives β-hydroxynitriles in good yields with moderate to good diastereoselectivity.
The evolution of binary fractions in globular clusters

We study the evolution of binary stars in globular clusters using a new Monte Carlo approach combining a population synthesis code (StarTrack), and a simple treatment of dynamical interactions in the dense cluster core using a new tool for computing 3-body and 4-body interactions (Fewbody). We find that the combination of stellar evolution and dynamical interactions (binary–single and binary–binary) leads to a rapid depletion of the binary population in the cluster core. The maximum binary fraction today in the core of a typical dense cluster like 47 Tuc, assuming an initial binary fraction of 100%, is only about 5–10%. We show that this is in good agreement with recent HST observations of close binaries in the core of 47 Tuc, provided that a realistic distribution of binary periods is used to interpret the results. Our findings also have important consequences for the dynamical modeling of globular clusters, suggesting that “realistic models” should incorporate much larger initial binary fractions than has usually been done in the past.
GENERALIZED FIBONACCI NUMBERS AND DIMER STATISTICS

We establish new product identities involving the q-analogue of the Fibonacci numbers. We show that the identities lead to alternate expressions of generating functions for close-packed dimers on non-orientable surfaces.
Synthesis, Structure Determination, and Aqueous Durability of Cs2ZrSi3O9

The structure of Cs2ZrSi3O9 synthesized using a sol–gel method was determined from the Rietveld refinement of experimental powder X-ray diffraction data. The refinement confirmed that this compound was isostructural with wadeite: its structure was hexagonal (space group P63/m), and its lattice parameters were a= 7.2303(2) A and c= 10.2682(4) A. The aqueous durability of Cs2ZrSi3O9 varied, depending on the solution conditions. In modified leach tests with buffered (pH 7) and unbuffered solutions, the 7-d cesium release rates were <1.2 × 10−4 g·(m2·day)−1, which indicated high aqueous durability. However, in unsaturated, unbuffered solutions with a pH of 9–10, the durability was much lower, with 7-d cesium release rates of 2.2 × 10−3 g·(m2·day)−1. The ability of this material to retain cesium in aqueous environments can be explained by its condensed ring structure, in which the size of the channel openings is smaller than the diameter of a Cs+ ion. However, dissolution of the network silicate occurred at high pH, which resulted in the release of cesium.
From the Debt Crisis Toward Economic Stability: An Analysis of the Consistency of Macroeconomic Policies in Mexico

This paper uses a simple framework based on the government budget constraint to analyze the consistency of macroeconomic policies undertaken in Mexico during the period 1978 to mid-1991. It was found that the interaction between the actual implementation of economic policies and economic agents` perceptions about the sustainability of those policies can account, to a large extent, for the behavior of key macroeconomic variables during the period under study. The paper also highlights the costs of adjustment involved in the most recent Mexican stabilization program arising from concerns about the sustainability of the announced policies.
Progress in absorber R&D 2: windows

A program is under way to develop liquid-hydrogen energy absorbers for ionization cooling of muon-beam transverse emittance. Minimization of multiple-scattering-induced beam heating requires thin windows. The first window prototype has been destructively tested, validating the finite-element-analysis model and the design approach.
Local systems over complements of hyperplanes and the Kac-Kazhdan conditions for singular vectors

In this paper we strenghten a theorem by Esnault-Schechtman-Viehweg, [3], which states that one can compute the cohomology of a complement of hyperplanes in a complex affine space with coefficients in a local system using only logarithmic global differential forms, provided certain ”Aomoto non-resonance conditions” for monodromies are fulfilled at some ”edges” (intersections of hyperplanes). We prove that it is enough to check these conditions on a smaller subset of edges, see Theorem 4.1. We show that for certain known one dimensional local systems over configuration spaces of points in a projective line defined by a root system and a finite set of affine weights (these local systems arise in the geometric study of Knizhnik-Zamolodchikov differential equations, cf. [8]), the Aomoto resonance conditions at non-diagonal edges coincide with Kac-Kazhdan conditions of reducibility of Verma modules over affine Lie algebras, see Theorem 7.1.
Sequence Requirements for Localization of Human Cytomegalovirus Tegument Protein pp28 to the Virus Assembly Compartment and for Assembly of Infectious Virus

The human cytomegalovirus UL99 open reading frame encodes a 190-amino-acid (aa) tegument protein, pp28, that is myristoylated and phosphorylated. pp28 is essential for assembly of infectious virus, and nonenveloped virions accumulate in the cytoplasm of cells infected with recombinant viruses with a UL99 deletion. pp28 is localized to the endoplasmic reticulum-Golgi intermediate compartment (ERGIC) in transfected cells, while in infected cells, it is localized together with other virion proteins in a juxtanuclear compartment termed the assembly compartment (AC). We investigated the sequence requirements for pp28 trafficking to the AC and assembly of infectious virus. Our studies indicated that the first 30 to 35 aa were required for localization of pp28 to the ERGIC in transfected cells. Mutant forms of pp28 containing only the first 35 aa localized with other virion structural proteins to cytoplasmic compartments early in infection, but localization to the AC at late times required a minimum of 50 aa. In agreement with previous reports, we demonstrated that the deletion of a cluster of acidic amino acids (aa 44 to 59) prevented wild-type trafficking of pp28 and recovery of infectious virus. A recombinant virus expressing only the first 50 aa was replication competent, and this mutant, pp28, localized to the AC in cells infected with this virus. These findings argued that localization of pp28 to the AC was essential for assembly of infectious virus and raised the possibility that amino acids in the amino terminus of pp28 have additional roles in the envelopment and assembly of the virion other than simply localizing pp28 to the AC.
AN ASSESSMENT OF DYNAMIC BEHAVIOR IN THE U.S. CATFISH MARKET: AN APPLICATION OF THE GENERALIZED DYNAMIC ROTTERDAM MODEL

The generalized dynamic Rotterdam model was used in estimating U.S. demand for disaggregated catfish. The overall goal was to examine habit persistence in consumption and to determine the adjustment process in demand. Results indicated that it took up to 1 month for catfish-product demand to fully adjust to changes in expenditures and prices. Additionally, habit persistence played a role in demand where present consumption of a given product was positively affected by past consumption of that product. Consequently, U.S. catfish demand was significantly more elastic in the long-ran.
Niche products, generic products, and consumer search

We endogenize product design in a model of sequential search with random firm-consumer match value a la Wolinsky (Quart J Econ 96:493–511, 1986) and Anderson and Renault (RAND J Econ 30:719–735, 1999). We focus on a product design choice by which a firm can control the dispersion of consumer valuations for its product; we interpret low-dispersion products as “generic” and high-dispersion products as “nichy.” Equilibrium product design depends on a feedback loop: when reservation utility is high (low), the marginal customer’s match improves (worsens) with more nichy products, encouraging high (low) differentiation by firms. In turn, when firms offer more nichy products, this induces more intense search; depending on search costs, this could raise or lower consumers’ reservation utility. Remarkably, when the match distribution satisfies a hazard rate condition, firm and consumer interests align: equilibrium product design always adjusts to the level that maximizes utility. When this condition is not met, either multiple equilibria (one nichy, the other generic) or one asymmetric equilibrium (generic and nichy firms coexist) can arise; we argue that the former is more likely for common specifications of consumer preferences.
Convergence of a balancing domain decomposition by constraints and energy minimization

A convergence theory is presented for a substructuring preconditioner based on constrained energy minimization concepts. The substructure spaces consist of local functions with zero values of the constraints, while the coarse space consists of minimal energy functions with the constraint values continuous across substructure interfaces. In applications, the constraints include values at corners and optionally averages on edges and faces. The preconditioner is reformulated as an additive Schwarz method and analysed by building on existing results for balancing domain decomposition. The main result is a bound on the condition number based on inequalities involving the matrices of the preconditioner. Estimates of the form C(1+log2(H/h)) are obtained under the standard assumptions of substructuring theory. Computational results demonstrating the performance of method are included. Published in 2003 by John Wiley & Sons, Ltd.
MEDIA CAPTURE AND INFORMATION MONOPOLIZATION IN JAPAN

In this paper, we investigate the unique institution of the Japanese press industry called kisha club system, which is deemed as the symbol of media capture by the government, and collusion in the media industry. By tracing through its history, we show how the institution has developed as a result of the government's attempt to control the media, and the media's incentive to use the alluring opportunity provided by the government to limit the rivalry within the industry. We find that the distribution of political power is a major factor behind the collusive press-politics relationship. By providing a simple model that links the distribution of political power and the media capture, we explain why this institutional arrangement has been so persistent in Japan.
On the spectrum of Wenger graphs

Abstract Let q = p e , where p is a prime and e ⩾ 1 is an integer. For m ⩾ 1 , let P and L be two copies of the ( m + 1 ) -dimensional vector spaces over the finite field F q . Consider the bipartite graph W m ( q ) with partite sets P and L defined as follows: a point ( p ) = ( p 1 , p 2 , … , p m + 1 ) ∈ P is adjacent to a line [ l ] = [ l 1 , l 2 , … , l m + 1 ] ∈ L if and only if the following m equalities hold: l i + 1 + p i + 1 = l i p 1 for i = 1 , … , m . We call the graphs W m ( q ) Wenger graphs. In this paper, we determine all distinct eigenvalues of the adjacency matrix of W m ( q ) and their multiplicities. We also survey results on Wenger graphs.