cssi/SciSciGPT-SciSciNet huggingface dataset:
Mechanically alloyed Al-I composite materials

Abstract Mechanically alloyed aluminum–iodine composites with iodine concentrations from 4 to 17 wt% were prepared from elemental aluminum and iodine. A reference sample was prepared from aluminum and AlI3. A shaker mill and an attritor mill, operating at both room temperature and liquid nitrogen temperature, were used for preparation. Materials were characterized by electron microscopy and X-ray diffraction. The iodine release upon heating was studied using thermogravimetry. Mechanical alloying was found to be effective for preparation of Al–I composites that do not release iodine until the material is brought to high temperatures. Mechanical alloying in nitrogen gas at liquid nitrogen temperature was more effective in preparing stabilized Al–I composites than milling at room temperature. Iodine was not retained in materials milled directly in liquid nitrogen. In addition to poorly crystalline AlI3, other iodine compounds were present in the products. Assuming that the products are similar to other mechanically alloyed materials, it is expected that iodine is mixed with aluminum on the atomic scale, forming metastable Al–I compounds where iodine may be bonded to aluminum more strongly than in AlI3, explaining why their thermal decomposition and respective iodine release occur at higher temperatures compared to decomposition and boiling of AlI3.
Constrained Discounted Markov Decision Processes and Hamiltonian Cycles

This paper establishes new links between stochastic and discrete optimization. We consider the following three problems for discrete time Markov Decision Processes with finite states and action sets: i find an optimal deterministic policy for a discounted problem with constraints, ii find an optimal stationary policy for a weighted discounted problem with constraints, iii find an optimal deterministic policy for a weighted discounted problem with constraints. We formulate mathematical programs for problems i--iii and show that the Hamiltonian Cycle Problem is a special case of each of these problems. Therefore problems i--iii are NP-hard. We also provide new mathematical programming formulations for the Hamiltonian Cycle and Traveling Salesman Problems.
Glacial deep ocean sequestration of CO2 driven by the eastern equatorial Pacific biologic pump

Abstract The potential influence of low latitude ocean primary productivity on glacial atmospheric carbon dioxide levels has proven challenging to deduce using mass accumulation rates (MARs) of biogenic particulates in deep sea sediment cores. Benthic foraminiferal B/Ca serves as a proxy for past seawater calcite saturation state, and thereby provides a fresh perspective on this outstanding paleoceanographic problem. Here we employ Cibicidoides wuellerstorfi B/Ca in the Panama Basin region of the eastern equatorial Pacific (EEP) to investigate the nature of deep tropical Pacific carbon storage over the past 50 ka BP. We present evidence for persistently lower deep Panama Basin calcite saturation state, reflecting an increase in total carbon dioxide storage, during the last ice age relative to the Holocene. These results reflect the modification of inflowing deep waters by overlying export productivity, and support the concept of an invigorated glacial EEP soft-tissue pump possibly driven by oceanic nutrient (iron and silica) redistribution. Benthic Cibicidoides spp. carbon-13 is consistent with this conclusion by exhibiting substantially lighter values during glacial time, reflecting the accumulation of metabolic carbon dioxide in the deep tropical Pacific. Counterintuitively, downcore application of the Globorotalia menardii calcite fragmentation index (MFI) reveals enhanced glacial sedimentary calcite preservation in the Panama Basin. Together these results point towards a systematic decoupling of bottom water chemistry from biogenic burial fluxes: the crux of the aforementioned traditional paleoproductivity problem.
Gas phase chemistry of neutral metal clusters: Distribution, reactivity and catalysis

Abstract Recent work on gas phase distribution, reactivity, and catalysis of neutral metal, metal oxide/carbide/sulfide clusters, investigated by single photon ionization coupled with time-of-flight mass spectrometry, is reviewed. Oxidation–reduction and bond activation reactions catalyzed by neutral metal and metal compound clusters are investigated, in order to understand the catalytic process at a molecular level, and reveal possible full catalytic cycles for related condensed phase reactivity and processes. Density functional theory calculations for these systems enable exploration of the geometric and electronic structures of clusters and determination of reaction intermediates and transition states, as well as reaction mechanisms, by comparing the results of theoretical calculations and experimental observations. Reactivity of metal oxide clusters with small gas phase molecules (CO, SO2, and hydrocarbons), which is associated with the oxygen-rich or -deficient nature of the cluster, is discussed in terms of bond enthalpy, cluster spin state, and unpaired spin density of the clusters. For bond activation catalytic reactions on metal and metal compound clusters, we describe how adsorption of reactant molecules on active metal sites of clusters, association energy between reactant molecules and clusters, and activation energy (barriers) on the reaction potential energy surface can be constructed and compared to generate a reaction mechanism. Experimental and theoretical studies shown in this review also provide unique insights into how the application of gas phase neutral metal cluster chemistry is instructive in the understanding of important fundamental aspects of practical catalysis in the condensed phase.
Improving cost effectiveness in an existing product line using component product platforms

Previously, we introduced a new method for improving commonality in a highly customised, low volume product line using component product platforms. The method provides a bottom-up platform approach to redesign family members originally developed one-at-a-time to meet specific customer requirements. In this paper, we extend the method with an activity-based costing (ABC) model to specifically capture the manufacturing costs in the product line, including the cost associated with implementing a platform strategy. The valve yoke example is revisited in this paper, the customised ABC model is defined, two design strategy alternatives are addressed, and the new method is used to determine which alternative is better at resolving the trade-off between commonality, total cost, and product performance. The proposed method shows promise for creating a product platform portfolio from a set of candidate component platforms that is most cost-effective within an existing product line. The proposed method allows for ar...
Reduced energy decoding of MPEG streams

Long battery life and high performance multimedia decoding are competing design goals for portable appliances. For a target level of QoS, the achievable battery life can be increased by dynamically adjusting the supply voltage throughout execution. In this paper, an efficient offline scheduling algorithm is proposed for preprocessing stored MPEG audio and video streams. It computes the order and voltage settings at which the appliance's CPU decodes the frames, reducing energy consumption without violating timing or buffering constraints. Our experimental results elucidate the trade-off between QoS and energy consumption. They demonstrate that the scheduler reduces CPU energy consumption by 19%, without any sacrifice of quality, and by nearly 50%, with only slightly reduced quality. The results also evaluate how the QoS/energy trade-off is affected by buffering and processor speed.
Narrow band noise as a model of time-dependent accelerations - Study of the stability of a fluid surface in a microgravity environment

We introduce a stochastic model to analyze in quantitative detail the effect of the high frequency components of the residual accelerations onboard spacecraft (often called g-jitter) on fluid motion. The residual acceleration field is modeled as a narrow band noise characterized by three independent parameters: its intensity G squared, a dominant frequency Omega, and a characteristic spectral width tau exp -1. The white noise limit corresponds to Omega tau goes to O, with G squared tau finite, and the limit of a periodic g-jitter (or deterministic limit) can be recovered for Omega tau goes to infinity, G squared finite. The analysis of the response of a fluid surface subjected to a fluctuating gravitational field leads to the stochastic Mathieu equation driven by both additive and multiplicative noise. We discuss the stability of the solutions of this equation in the two limits of white noise and deterministic forcing, and in the general case of narrow band noise. The results are then applied to typical microgravity conditions.
Low-Velocity Intense Source of Atoms from a Magneto-optical Trap.

We have produced and characterized an intense, slow, and highly collimated atomic beam extracted from a standard vapor cell magneto-optical trap (MOT). The technique used is dramatically simpler than previous methods for producing very cold atomic beams. We have created a 0.6 mm diameter rubidium atomic beam with a continuous flux of $5\ifmmode\times\else\texttimes\fi{}{10}^{9}/\mathrm{s}$ and a pulsed flux 10 times greater. Its longitudinal velocity distribution is centered at 14 m/s with a FWHM of 2.7 m/s. Through an efficient recycling process, 70% of the atoms trapped in the MOT are loaded into the atomic beam.
Mesons in a collinear QCD model

A phenomenological model for the quark structure of mesons is considered. The model is based on the tube model for QCD, where all quanta with nonzero transverse momenta are neglected. In the limit that the mass term of the gluons goes to infinity, the model is equivalent to a combination of the {close_quote}t Hooft and Gross-Neveu models and can be solved semianalytically. The model has the properties of confinement, chiral symmetry breaking, and asymptotic freedom and thus resembles QCD in three key respects. Spectra, distribution amplitudes, and form factors of mesons are analyzed. {copyright} {ital 1997} {ital The American Physical Society}
Probing plasma properties and dynamics inside the Sun

Abstract Helioseismology experiment MDI on board the SOHO spacecraft has provided tremendous amount of new information about the thermodynamic properties and dynamics of plasma in the Sun’s interior, uncovering remarkable new perspectives for studying complex interactions between turbulent convection, rotation and magnetism below the solar surface, and their relationship to solar irradiance variations and coronal activity. In particular, the new results have revealed the deep structure of sunspots and associated complicated patterns of plasma flows, the dynamics of the emerging magnetic flux and formation of active regions, the supergranular structure and dynamics of the upper convection zone, as well as the global structures and circulation patterns in the deep interior, evolving with the activity cycle. In addition, first attempts are made to find the links between the internal dynamics and processes of magnetic energy release in the solar corona. Understanding these results, often puzzling and counter-intuitive, is a major challenge for MHD theories of astrophysical plasma.
Systems Theory and Thinking as a Foundational Theory in Human Resource Development—A Myth or Reality?

This study reviews systems theory and thinking (ST&T) as a foundational discipline or theory in human resource development (HRD) research and practice. Using systematic evidence review (SER) of the...
Applying weighted PageRank to author citation networks

This article aims to identify whether different weighted PageRank algorithms can be applied to author citation networks to measure the popularity and prestige of a scholar from a citation perspective. Information retrieval (IR) was selected as a test field and data from 1956–2008 were collected from Web of Science. Weighted PageRank with citation and publication as weighted vectors were calculated on author citation networks. The results indicate that both popularity rank and prestige rank were highly correlated with the weighted PageRank. Principal component analysis was conducted to detect relationships among these different measures. For capturing prize winners within the IR field, prestige rank outperformed all the other measures. © 2011 Wiley Periodicals, Inc.
Biogeochemical controls and isotopic signatures of nitrous oxide production by a marine ammonia-oxidizing bacterium

Abstract. Nitrous oxide (N2O) is a trace gas that contributes to the greenhouse effect and stratospheric ozone depletion. The N2O yield from nitrification (moles N2O-N produced per mole ammonium-N consumed) has been used to estimate marine N2O production rates from measured nitrification rates and global estimates of oceanic export production. However, the N2O yield from nitrification is not constant. Previous culture-based measurements indicate that N2O yield increases as oxygen (O2) concentration decreases and as nitrite (NO2−) concentration increases. Here, we have measured yields of N2O from cultures of the marine β-proteobacterium Nitrosomonas marina C-113a as they grew on low-ammonium (50 μM) media. These yields, which were typically between 4 × 10−4 and 7 × 10−4 for cultures with cell densities between 2 × 102 and 2.1 × 104 cells ml−1, were lower than previous reports for ammonia-oxidizing bacteria. The observed impact of O2 concentration on yield was also smaller than previously reported under all conditions except at high starting cell densities (1.5 × 106 cells ml−1), where 160-fold higher yields were observed at 0.5% O2 (5.1 μM dissolved O2) compared with 20% O2 (203 μM dissolved O2). At lower cell densities (2 × 102 and 2.1 × 104 cells ml−1), cultures grown under 0.5% O2 had yields that were only 1.25- to 1.73-fold higher than cultures grown under 20% O2. Thus, previously reported many-fold increases in N2O yield with dropping O2 could be reproduced only at cell densities that far exceeded those of ammonia oxidizers in the ocean. The presence of excess NO2− (up to 1 mM) in the growth medium also increased N2O yields by an average of 70% to 87% depending on O2 concentration. We made stable isotopic measurements on N2O from these cultures to identify the biochemical mechanisms behind variations in N2O yield. Based on measurements of δ15Nbulk, site preference (SP = δ15Nα−δ15Nβ), and δ18O of N2O (δ18O-N2O), we estimate that nitrifier-denitrification produced between 11% and 26% of N2O from cultures grown under 20% O2 and 43% to 87% under 0.5% O2. We also demonstrate that a positive correlation between SP and δ18O-N2O is expected when nitrifying bacteria produce N2O. A positive relationship between SP and δ18O-N2O has been observed in environmental N2O datasets, but until now, explanations for the observation invoked only denitrification. Such interpretations may overestimate the role of heterotrophic denitrification and underestimate the role of ammonia oxidation in environmental N2O production.
Strings as solitons & black holes as strings

Abstract Supersymmetric closed string theories contain an infinite tower of BPS-saturated, oscillating, macroscopic strings in the perturbative spectrum. When these theories have dual formulations, this tower of states must exist nonperturbatively as solitons in the dual theories. We present a general class of exact solutions of low-energy supergravity that corresponds to all these states. After dimensional reduction they can be interpreted as supersymmetric black holes with a degeneracy related to the degeneracy of the string states. For example, in four dimensions we obtain a point-like solution which is asymptotic to a stationary, rotating, electrically-charged black hole with Regge-bounded angular momentum and with the usual ring-singularity replaced by a string source. This further supports the idea that the entropy of supersymmetric black holes can be understood in terms of counting of string states. We also discuss some applications of these solutions to string duality.
A Moving Finite Element Model of the Tokamak Scrapeoff Layer

Most numerical simulations of the tokamak scrapeoff layer use a mapping to flux coordinates and a piecewise equidistributed grid in those coordinates to resolve multiple length scales and anisotropy. We have developed an alternative numerical method using simple cylindrical coordinates with a complex adaptive grid scheme, based on an unstructured grid of triangles which move adaptively, aligning themselves with the magnetic field and concentrating in regions of sharp gradients.
ASYMPTOTIC STABILITY OF TRAVELING WAVE SOLUTIONS FOR PERTURBATIONS WITH ALGEBRAIC DECAY

Abstract For a class of scalar partial differential equations that incorporate convection, diffusion, and possibly dispersion in one space and one time dimension, the stability of traveling wave solutions is investigated. If the initial perturbation of the traveling wave profile decays at an algebraic rate, then the solution is shown to converge to a shifted wave profile at a corresponding temporal algebraic rate, and optimal intermediate results that combine temporal and spatial decay are obtained. The proofs are based on a general interpolation principle which says that algebraic decay results of this form always follow if exponential temporal decay holds for perturbation with exponential spatial decay and the wave profile is stable for general perturbations.
Peristaltic Pumping of Solid Particles Immersed in a Viscoelastic Fluid

Peristaltic pumping of fluid is a fundamental method of transport in many biological processes. In some instances, particles of appreciable size are transported along with the fluid, such as ovum transport in the oviduct or kidney stones in the ureter. In some of these biological settings, the fluid may be viscoelastic. In such a case, a nonlinear constitutive equation to describe the evolution of the viscoelastic contribution to the stress tensor must be included in the govern- ing equations. Here we use an immersed boundary framework to study peristaltic transport of a macroscopic solid particle in a viscoelastic fluid governed by a Navier-Stokes/Oldroyd-B model. Numerical simulations of peristaltic pumping as a function of Weissenberg number are presented. We examine the spatial and temporal evolution of the polymer stress field, and also find that the viscoelasticity of the fluid does hamper the overall transport of the particle in the direction of the wave.
Efficient synthesis of highly functionalized tetrahydropyridopyrimidines by a novel three-component coupling reaction

We report the development of a novel three-component coupling reaction (3CC) for the synthesis of alkoxy tetrahydropyridopyrimidines. Systematic optimization of reaction parameters identified 3CC conditions tolerant of a wide array of functionality at all three sites of diversity, providing densely functionalized products in moderate to excellent yields. The newly developed chemistry has since been applied to the lead optimization process on a novel drug discovery program, facilitating rapid compound advancement.
Supersymmetry algebra and BPS states of super Yang-Mills theories on noncommutative tori

Abstract We consider 10-dimensional super Yang–Mills theory with topological terms compactified on a noncommutative torus. We calculate supersymmetry algebra and derive BPS energy spectra from it. The cases of d-dimensional tori with d=2,3,4 are considered in full detail. SO(d,d, Z ) -invariance of the BPS spectrum and relation of new results to the previous work in this direction are discussed.
Recent developments in the accessibility of presidential papers and other presidential historical materials

Abstract The past decade has seen a significant expansion in the accessibility of presidential papers and other historical materials. Amendments to the Freedom of Information Act, the issuance of a new Executive Order on the declassification of documents, the rulings of the Supreme Court on the papers and tape recordings of President Nixon, the passage by Congress of the Presidential Records Act of 1978 and the new developments in presidential libraries are examined to discern their impact on increasing the access to presidential records.
Asset Trading Volume with Dynamically Complete Markets and Heterogeneous Agents

Trading volume of infinitely lived securities, such as equity, is generically zero in Lucas asset pricing models with heterogeneous agents. More generally, the end-of-period portfolio of all securities is constant over time and states in the generic economy. General equilibrium restrictions rule out trading of equity after an initial period. This result contrasts the prediction of portfolio allocation analyses that portfolio rebalancing motives produce nontrivial trade volume. Therefore, other causes of trade must be present in asset markets with large trading volume.
Financing of Growth in Agricultural Cooperatives

This study examines the hypothesis that cooperatives suffer from a shortage of equity capital because of ownership structure and nonmarketability of cooperative equity. The empirical findings indicate that agricultural cooperatives finance nearly half their growth with equity. Contrary to theoretical expectations, the equity financing proportion of cooperatives is found to be statistically indistinguishable from the national average of nonfinancial corporations for 1973-1983 and is higher than the national average since 1984. Cooperatives are observed to raise new debt mainly through short-term borrowing. This indicates that banks may be reluctant to lend long-term to cooperatives because of their "unorthodox" ownership structure.
Growth diagrams for the Schubert multiplication

We present a partial generalization of the classical Littlewood-Richardson rule (in its version based on Schutzenberger's jeu de taquin) to Schubert calculus on flag varieties. More precisely, we describe certain structure constants expressing the product of a Schubert and a Schur polynomial. We use a generalization of Fomin's growth diagrams (for chains in Young's lattice of partitions) to chains of permutations in the so-called k-Bruhat order. Our work is based on the recent thesis of Beligan, in which he generalizes the classical plactic structure on words to chains in certain intervals in k-Bruhat order. Potential applications of our work include the generalization of the S"3-symmetric Littlewood-Richardson rule due to Thomas and Yong, which is based on Fomin's growth diagrams.
La ciudad jardín en los suburbios del desierto de Sonora

Resumen es: Convencidos de la necesidad de incorporar criterios de economia, y controlar la tendencia al consumo y a la explotacion de recursos que parece regir nues...
Variational and Geometric Structures of Discrete Dirac Mechanics

In this paper, we develop the theoretical foundations of discrete Dirac mechanics, that is, discrete mechanics of degenerate Lagrangian/Hamiltonian systems with constraints. We first construct discrete analogues of Tulczyjew’s triple and induced Dirac structures by considering the geometry of symplectic maps and their associated generating functions. We demonstrate that this framework provides a means of deriving discrete Lagrange–Dirac and nonholonomic Hamiltonian systems. In particular, this yields nonholonomic Lagrangian and Hamiltonian integrators. We also introduce discrete Lagrange–d’Alembert–Pontryagin and Hamilton–d’Alembert variational principles, which provide an alternative derivation of the same set of integration algorithms. The paper provides a unified treatment of discrete Lagrangian and Hamiltonian mechanics in the more general setting of discrete Dirac mechanics, as well as a generalization of symplectic and Poisson integrators to the broader category of Dirac integrators.
Surface Stress Effects On Fracture

The effects of surface stress on fracture are reviewed. Calculations by Thomson et al. seem to suggest that surface stresses do not affect cleavage fracture when the crack propagates in a self similar manner even though the surface stress can lead to large stresses near the crack tip. However, surface stresses may have an important effect on dislocation emission near the crack tip. A simple analysis is offered to show how these effects may be incorporated into a modified Rice ductile-brittle fracture criterion by adding a term to the unstable stacking energy that takes into account the energy to form an incipient ledge.
Optimization of nested XQuery expressions with orderby clauses

XQuery, the defacto XML query language, is a functional language with operational semantics, which precludes the direct application of classical query optimization techniques. The features of XQuery, such as nested expressions and ordered semantics, further aggravate this situation. The appropriate extension of existing optimization techniques to XQuery processing hence represents an important and non-trivial task. We propose an algebraic rewriting technique of nested XQuery expressions containing explicit orderby clauses. Unlike prior work, this technique enables the optimization of nested XQuery expressions not only with set but also with ordered sequence semantics. Our technique is based on two steps. First, we perform order-sensitive algebraic query unnesting. Second, we apply query minimization techniques that exploit pairwise XPath set containment after pulling up order-sensitive operations. We illustrate how our proposed technique is able to not only successfully tackle the XQuery logical optimization problem solved in the NEXT framework, but also to correctly support ordered semantics. We have implemented the proposed optimization techniques on top of the XAT algebraic framework in our RainbowCore project. We show the performance gain achievable by our approach using an experimental study with the RainbowCore engine.
Extremal branes as elementary particles

Abstract The supersymmetric p -branes of type II string theory can be interpreted after compactification as extremal black holes with zero entropy and infinite temperature. We show how the p -branes avoid this apparent, catastrophic instability by developing an infinite mass gap. Equivalently, these black holes behave like elementary particles: they are dressed by effective potentials that prevent absorption of impinging particles. In contrast, configurations with 2, 3, and 4 intersecting branes and their non-extremal extensions, behave increasingly like conventional black holes. These results extend and clarify earlier work by Holzhey and Wilczek in the context of four-dimensional dilaton gravity.
Prediction of Vortex Breakdown in Leading Edge Vortices Above Slender Delta Wings

This paper applies a recent theory on the axisymmetric vortex breakdown process to experimental flow profiles of leading edge vortices above slender delta wings at high angles of attack. Using several simplifying assumptions about the nature of the vortex generation process and its swirl ratio dependence on angle of attack, the necessary conditions for the breakdown of the vortices are calculated. The computations show good agreement with the available experimental data and, thus, provide an efficient method to accurately predict the burst locations as function of angle of attack along a delta wing. Specifically, this can be predicted out of a single set of measurements at a lower angle of attack where no sign of breakdown yet exists. In addition, the calculation of the swirl ratio based on the ratio of the maximum circumferential speed over the maximum axial speed, at the breakdown conditions reveals that it is almost independent of both the angle of attack and location along the wing chord, having an average value of 0.58. This swirl ratio may, therefore, serve as a simple universal criterion for the appearance of breakdown along leading edge vortices above slender wings with sharp edges. Nomenclature
A predictability analysis of network traffic

Abstract This paper assesses the predictability of network traffic by considering two metrics: (1) how far into the future a traffic rate process can be predicted with bounded error; (2) what the minimum prediction error is over a specified prediction time interval. The assessment is based on two stationary traffic models: the auto-regressive moving average and the Markov-modulated poisson process. In this paper, we do not aim to propose the best traffic (prediction) model, which is obviously a hard and arguable issue. Instead, we focus on the constrained predictability estimation with assumption and discussion about the modeling accuracy. The specific time scale or bandwidth utilization target of a predictive network control actually forms the constraint. We argue that the two models, though both short-range dependent, can capture statistics of (self-similar) traffic quite accurately for the limited time scales of interests in measurement-based traffic management. This argument, in mathematical terms, simply reflects the fact that the summarized exponential (correlation) functions may approximate a hyperbolical one very well. Our study reveals that the applicability of traffic prediction is limited by the deteriorating prediction accuracy with increasing prediction interval. From both analytical and numerical studies, we explore the different roles of traffic statistics, either at the 1st-order or the 2nd-order, in traffic predictability. Particularly, the statistical multiplexing and proper measurement (e.g. sampling/filtering) of traffic show positive effects. Experimental results suggest promising backbone traffic prediction, and generally enhanced predictability if small time-scale traffic variations, which are usually of less importance to bandwidth allocation and call admission control, have been filtered out. The numerical results in the paper provide quantized reference to the optimal online traffic predictability for network control purposes.
Palladium-Catalyzed Carboamination of Alkenes Promoted by N-Fluorobenzenesulfonimide via C−H Activation of Arenes

This report describes a unique Pd-catalyzed oxidative carboamination of protected aminoalkenes in which inexpensive unactivated nucleophilic arenes are incorporated to give carboamination products in good yields. A variety of protected amide and carbamate groups are tolerated, and various five-, six-, and seven-membered rings are formed in good yields. Under these conditions, halobenzenes are activated at the C−H bond rather than the C−X bond, and very high regioselectivity for the para substitution product is observed in all cases. We propose that this carboamination takes place via electrophilic aromatic substitution of a Pd(IV) alkyl intermediate.
Economic policy and income distribution in China.

Abstract Using the Kakwani interpolation method to reconstruct rural and urban size distributions, the authors present Lorenz curve estimates for Chinese income distribution by period 1952–1986. The level of inequality is one of the lowest in the world. The change in inequality over time conforms to the experience of other less-developed countries. Although rural inequality increased after 1978, national inequality fell, due to a reduction in the rural-urban income gap.
Power spectrum calculation for the Cornell Wiggler A SASE experiment at BNL

Abstract Recently, we showed (Yu, Phys. Rev. E 58 (1998) 4991) that the widely used simulation code TDA3D, even though a single-frequency code, can be used to determine the power spectrum in the SASE process with excellent approximation in the exponential growth regime. In this paper, we apply this method to the BNL Cornell Wiggler A SASE experiment as an example. When the gain is not very high, there are many modes in the radiation, which seems to make the analytical calculation very difficult. However, we show that the increment of the radiation due to SASE over the spontaneous radiation can be expanded in terms of guided modes with rapid convergence. Thus when the spontaneous radiation is subtracted from the SASE power during the calculation, there is a good agreement between the analytical theory and the numerical simulation.
Analysis of Thomsen parameters for finely layered VTI media

Since the work of Postma and Backus, much has been learned about elastic constants in vertical transversely isotropic (VTI) media when the anisotropy is due to fine layering of isotropic elastic materials. Nevertheless, there has continued to be some uncertainty about the possible range of Thomsen's anisotropy parameters {epsilon} and {delta} for such media. The authors use both Monte Carlo studies and detailed analysis of Backus' equations for both two- and three-component layered media to establish the results presented. They show that {epsilon} lies in the range {minus}3/8 {le}{epsilon}{le}1/2[(v{sub p}{sup 2})(vp2{sup {minus}2})-1], for finely layered media; smaller positive and all negative values of {epsilon} occur for media with large fluctuations in the Lame parameter {lambda} in the component layers. They show that {delta} can also be either positive or negative, and that for constant density media, sign ({delta}) = sign ((v{sub p}{sup {minus}2}) - (v{sub s}{sup {minus}2})(v{sub s}{sup 2}/v{sub p}{sup 2})). Monte Carlo simulations show that among all theoretically possible random media, positive and negative {delta} are equally likely in finely layered media. (Of course, the {delta}s associated with real earth materials may span some smaller subset of those that are theoretically possible, but answering this important question is beyondmore » the authors present scope.) Layered media having large fluctuations in {lambda} are those more likely to have positive {delta}. This is somewhat surprising since {epsilon} is often negative or a small positive number for such media, and the authors have the general constraining that {epsilon} - {delta}{gt}0 for layered VTI media. Since Gassmann's results for fluid-saturated porous media show that the mechanical effects of fluids influence only the Lame parameter {lambda}, not the shear modulus {mu}, these results suggest that small positive {delta} occurring together with small positive {epsilon} (but somewhat larger than {delta}) may be indicative of changing fluid content in a layered earth.« less
Learning in two languages: Spanish‐English immersion in U.S. public schools

Observes that, in some public schools in the USA, dual language instead of English only is being promoted as a plus and not the drawback it was once seen to be. Stresses there is still opposition to dual language or other languages being used in the US. Reckons that educated parents are the likeliest to seek dual‐language education for their children. Uses tables and figures to show the dual language options and variances. Concludes that there is potential for two‐way immersion to expand.
On spaces of modular forms spanned by eta-quotients

Abstract An eta-quotient of level N is a modular form of the shape f ( z ) = ∏ δ | N η ( δ z ) r δ . We study the problem of determining levels N for which the graded ring of holomorphic modular forms for Γ 0 ( N ) is generated by (holomorphic, respectively weakly holomorphic) eta-quotients of level N. In addition, we prove that if f ( z ) is a holomorphic modular form that is non-vanishing on the upper half plane and has integer Fourier coefficients at infinity, then f ( z ) is an integer multiple of an eta-quotient. Finally, we use our results to determine the structure of the cuspidal subgroup of J 0 ( 2 k ) ( Q ) .
Magic spinor product methods in loop integrals

We present an approach to higher point loop integrals using Chinese magic in the virtual loop integration variable. We show, using the five point function in the important ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}f\overline{f}+\ensuremath{\gamma}$ process for initial state radiation as a pedagogical vehicle, that we get an expression for it directly reduced to one scalar 5-point function and 4-, 3-, and 2- point integrals, thereby avoiding the computation of the usual three tensor 5-pt Passarino-Veltman reduction. We argue that this offers potential for greater numerical stability.
N-alkylation of pyridylalanine and pyridinecarboxylic acids and their use in synthesis of GnRH antagonists

Abstract A mild N-alkylation method has been developed for the synthesis of N-alkylated pyridiniumcarboxylic acids, using Ag2O-H2O catalysis to enhance the low-reactivity of pyridinecarboxylic acids. Two approaches were undertaken for the synthesis of a series of GnRH antagonists containing pyridinium moieties at the side chain: (1) incorporation of Npy-alkylated D-pyridylalanine during solid phase peptide chain assembly, and (2) coupling of the N-alkylated pyridinium-carboxylic acid to the resin-bound e-amino group of a D-lysine on a solid support.
Asymptotics of Barrier Option Pricing Under the CEV Process

Abstract We apply a singular perturbation analysis to some option pricing models. To illustrate the technique we first consider the European put option under the standard Black–Scholes model, with or without barriers. Then we consider the same option under the constant elasticity of variance (CEV) assumption, which is also called the square root process. In the CEV model the variability effects in the evolution of the asset, on which the option is based, are proportional to the square root of the asset value. We also consider the CEV model with barriers, and this leads to a rich asymptotic structure. The analysis assumes that the variability is small and employs the ray method of geometrical optics and matched asymptotic expansions.
Sensitivity of atmospheric neutrinos in Super-Kamiokande to Lorentz violation

This talk, given at CPT'13, showed Super-Kamiokande atmospheric-neutrino Monte Carlo sensitivity to Lorentz-violation effects using the perturbative model derived from the Standard-Model Extension.
Hepatitis C: A review and update☆☆☆★

Abstract The hepatitis C virus is an RNA virus that is a major cause of acute and chronic hepatitis. It is contracted chiefly through parenteral exposure to infected material such as blood transfusions or injections with dirty needles. Those at highest risk for development of hepatitis C are injection-drug users, people who snort cocaine with shared straws, and health care workers who are at risk for needle-stick and other exposures. Although the incidence of acute hepatitis C infection has fallen dramatically in the United States during the past decade, the prevalence of infection remains high (approximately 2.7 million Americans) because chronic hepatitis C develops in about 75% of those infected. Both acute and chronic hepatitis C are asymptomatic in most patients. However, chronic hepatitis C is a slowly progressive disease and results in severe morbidity in 20% to 30% of infected persons. Chronic hepatitis C is associated with a host of extrahepatic manifestations, many of which may be seen by dermatologists. The most frequent of these are mixed cryoglobulinemia with leukocytoclastic vasculitis and porphyria cutanea tarda. (J Am Acad Dermatol 2001;44:159-79.)
Robust performance for fixed inputs

We address the problem of robust performance analysis when the exogenous input is assumed to be fixed and known. This differs from standard approaches in the literature which assume that the exogenous input is an unknown element in a class of norm bounded signals. When the performance is measured by the l/sub /spl infin// norm, and the nominal plant is perturbed by LTV perturbations of bounded l/sub /spl infin// induced norm, we propose upper and lower bounds for the measure of robust performance. Two upper bounds are derived. The first one can have direct application in robust performance synthesis problems. The second one provides a tighter bound. Both conditions are (usually) much less conservative than the condition resulting from assuming a worst case exogenous input. The necessary condition follows from the result of Khammash for robust steady state performance. For certain classes of input signals, these upper and the lower bounds coincide, providing a necessary and sufficient condition. >
Adaptive stack filtering under the mean absolute error criterion

An adaptive filter algorithm is developed for the class of stack filters, which is a class of nonlinear filters obeying a weak superposition property. The adaptation algorithm can be interpreted as a learning algorithm for a group of decision-making units, the decisions of which are subject to a set of constraints called the stacking constraints. Under a rather weak statistical assumption on the training inputs, the decision strategy adopted by the group, which evolves according to the proposed learning algorithm, is shown to converge to an optimal strategy in the sense that it corresponds to an optimal stack filter under the mean absolute error-criterion, this adaptive algorithm requires only increment, decrement, and comparison operations and only local interconnections between the learning units. Implementation of the algorithm in hardware is therefore very feasible. An example is provided to show how the adaptive stack filtering algorithm can be used in an application in image processing. >
Optimizing Intensive Care Unit Discharge Decisions with Patient Readmissions

This work examines the impact of discharge decisions under uncertainty in a capacity-constrained high-risk setting: the intensive care unit ICU. New arrivals to an ICU are typically very high-priority patients and, should the ICU be full upon their arrival, discharging a patient currently residing in the ICU may be required to accommodate a newly admitted patient. Patients so discharged risk physiologic deterioration, which might ultimately require readmission; models of these risks are currently unavailable to providers. These readmissions in turn impose an additional load on the capacity-limited ICU resources. We study the impact of several different ICU discharge strategies on patient mortality and total readmission load. We focus on discharge rules that prioritize patients based on some measure of criticality assuming the availability of a model of readmission risk. We use empirical data from over 5,000 actual ICU patient flows to calibrate our model. The empirical study suggests that a predictive model of the readmission risks associated with discharge decisions, in tandem with simple index policies of the type proposed, can provide very meaningful throughput gains in actual ICUs while at the same time maintaining, or even improving upon, mortality rates. We explicitly provide a discharge policy that accomplishes this. In addition to our empirical work, we conduct a rigorous performance analysis for the family of discharge policies we consider. We show that our policy is optimal in certain regimes, and is otherwise guaranteed to incur readmission related costs no larger than a factor of $\hat{\rho}+1$ of an optimal discharge strategy, where $\hat{\rho}$ is a certain natural measure of system utilization.
Preparation of 5-Alkylthio and 5-Arylthiotetrazoles from Thiocyanates Using Phase Transfer Catalysis

Abstract A very efficient method of preparation for 5-alkyl and 5-arylthiotetrazoles from the corresponding alkyl or aryl halides is described. The halides are first transformed into thiocyanates which further react with azide, yielding the corresponding tetrazoles with [2+3] polar cycloaddition. All synthetic transformations are performed under phase transfer catalytic conditions. The yields vary from good to excellent except for the preparation of 5-benzylthiotetrazole, where the reaction between benzyl thiocyanate and azide [2+3] cycloaddition is in competition with nucleophilic substitution, with benzyl azide as product.
Dispersion-managed solitons at normal average dispersion

We find that in a dispersion-managed fiber, in which the strength of the dispersion management is above some threshold, solitons can exist with normal average dispersion. When the normal average dispersion is below some limiting value there exist two soliton solutions with the same pulse duration and different pulse energies. When the normal average dispersion is above this limiting value, no soliton exists. Both higher-energy and lower-energy solitons are dynamically stable in the parameter range that we considered.
Intended and Unintended Consequences of Prison Reform

Since the 1970s, U.S. federal courts have issued court orders condemning state prison crowding. However, the impact of these court orders on prison spending and prison conditions is theoretically ambiguous because it is unclear if these court orders are enforceable. We examine states’ responses to court interventions and show that these interventions generate higher per inmate incarceration costs, lower inmate mortality rates, and a reduction in prisoners per capita. If states seek to minimize the cost of crime through deterrence, an increase in prison costs should lead states to shift resources from corrections to other means of deterring crime such as welfare and education spending. However, we flnd that court interventions, that are associated with higher corrections expenditures, lead to lower welfare expenditures. This suggests that the burden of increased correctional spending is borne by the poor. Furthermore, states do not increase welfare spending after their release from court order; making the reduction in welfare spending permanent. Thus, our results suggest that states do not respond to prison reform in the manner prescribed by the deterrence model. States’ responses to prison reform are most consistent with the predictions in the empirical public flnance literature that indicate stickiness in expenditure categories and that increases in spending in programs that afiect the poor generate declines in expenditures in other program that are also targeted to the poor.
High-Dimensional Sparse Additive Hazards Regression

High-dimensional sparse modeling with censored survival data is of great practical importance, as exemplified by modern applications in high-throughput genomic data analysis and credit risk analysis. In this article, we propose a class of regularization methods for simultaneous variable selection and estimation in the additive hazards model, by combining the nonconcave penalized likelihood approach and the pseudoscore method. In a high-dimensional setting where the dimensionality can grow fast, polynomially or nonpolynomially, with the sample size, we establish the weak oracle property and oracle property under mild, interpretable conditions, thus providing strong performance guarantees for the proposed methodology. Moreover, we show that the regularity conditions required by the L 1 method are substantially relaxed by a certain class of sparsity-inducing concave penalties. As a result, concave penalties such as the smoothly clipped absolute deviation, minimax concave penalty, and smooth integration of co...
On maximum contention-free interleavers and permutation polynomials over integer rings

An interleaver is a critical component for the channel coding performance of turbo codes. Algebraic constructions are of particular interest because they admit analytical designs and simple, practical hardware implementation. Contention-free interleavers have been recently shown to be suitable for parallel decoding of turbo codes. In this correspondence, it is shown that permutation polynomials generate maximum contention-free interleavers, i.e., every factor of the interleaver length becomes a possible degree of parallel processing of the decoder. Further, it is shown by computer simulations that turbo codes using these interleavers perform very well for the Third Generation Partnership Project (3GPP) standard