cssi/SciSciGPT-SciSciNet huggingface dataset:
On the role of government in a stochastically growing open economy

Abstract The relationship between the size of government, economic growth, and volatility in a small open economy is analyzed. First, we characterize the stochastic equilibrium for a centrally planned economy, contrasting it with a closed economy. The role of government consumption expenditure both as a stabilizing and a destabilizing factor is discussed. The optimal size of government is derived and we find that an open economy will have a larger government if and only if it is a net creditor. Second, the stochastic equilibrium in a decentralized economy is characterized and the optimal tax structure derived. Finally, the role of government production expenditure and its impact on risk is briefly discussed.
Research highlights: microfluidics and magnets

In this highlight we present a snapshot of recent work using magnetic forces and particles to perform lab on a chip operations. Magnetic micro- & nanoparticles have been widely used for separations in cell biology & clinical diagnostics and as solid phase supports for reactions and chemical assays. Microscale approaches to control and manipulate magnetic particles can enable new functionality; allowing parallel and complex automation of assays, manipulation of fluids themselves, and precise separations based on small differences in magnetic properties. Here we discuss recent work demonstrating advances in these three areas.
Data-driven co-clustering model of internet usage in large mobile societies

Design and simulation of future mobile networks will center around human interests and behavior. We propose a design paradigm for mobile networks driven by realistic models of users' on-line behavior, based on mining of billions of wireless-LAN records. We introduce a systematic method for large-scale multi-dimensional co-clustering of web activity for thousands of mobile users at 79 locations. We find surprisingly that users can be consistently modeled using ten clusters with disjoint profiles. Access patterns from multiple locations show differential user behavior. This is the first study to obtain such detailed results for mobile Internet usage.
Noise predictive belief propagation

We introduce iterative noise whitening for belief-propagation-based channel detectors over intersymbol interference channels with correlated additive noise. In particular, we consider longitudinal magnetic recording systems. The proposed "noise predictive belief propagation" (NPBP) detector iteratively whitens the noise samples by modifying the edge probability computation. NPBP detectors based on finite impulse response and infinite impulse response prediction filters are developed. In addition, we introduce a novel prediction filter optimization method leading to a better noise whitening performance. Simulation results for both coded and uncoded systems show that significant improvements can be obtained.
Condensed rare-earth metal-rich tellurides. Extension of layered Sc6PdTe2-type compounds to yttrium and lutetium analogues and to Y7Te2, the limiting binary member

Abstract Six isotypic R6ZTe2 phases have been synthesized in Ta at elevated temperatures and characterized by single crystal X-ray refinements for R=Y, Z=Rh, Pd, Ag, Y and for R=Lu, Z=Cu, Ag. All crystallize in the Sc6PdTe2-type structure, Pnma, Z=4, a∼21.5 A, b∼4.1 A, c∼11.4 A. The results can be viewed as the replacement of Te3 atoms in the parent isotypic Sc2Te (or in the hypothetical Y2Te or Lu2Te analogues) by the above the Z, the Y example giving the new binary phase Y7Te2. The shorter (and stronger) metal-metal bonds concentrate in the region of metal (Z, Y) substitution, as revealed by larger integrated crystal orbital Hamilton population (ICOHP) values derived from linear muffin-tin-orbital (LMTO) calculations. Partial densities-of-states data for Y7Te2 reflect a similar behavior. Individual R–R bond distances are seen to deviate appreciably from the more fundamental overlap population measures for each.
Virtual reality in scientific visualization

Immersing the user in the solution, virtual reality reveals the spatially complex structures in computational science in a way that makes them easy to understand and study. But beyond adding a 3D interface, virtual reality also means greater computational complexity.
Pragmatism, adaptation, and total quality management: philosophy and science in the service of managing continuous improvement

Today's engineering managers who use total quality management (TQM) face the challenge of moving it from adoption to seamless incorporation into their organizations. Both the application and the theory of TQM can be advanced through an examination of the philosophy of pragmatism and the sciences of adaptation. Pragmatism provides a philosophy that establishes a theory for incorporating TQM into engineers' management practice; it derives its epistemology from actual experience. In essence, pragmatism suggests that practical experience, such as that gained from the continuous improvement of and experimentation with TQM, provides the basis for successful organizational performance. The sciences of adaptation identify the characteristics of organizations that promote successful adaptation. They suggest that incremental adjustments to ongoing change are keys to effective and successful growth. This paper explores both philosophy and science to identify actions and attitudes that can enable the success of TQM in an organization.
Nanotechnology: applications and potentials for heterogeneous catalysis

Nanotechnology offers the potential to design, synthesize, and control at nanometer length scale. While the catalysis community has many techniques at their disposal to synthesize catalytic materials at such a scale, the ability to fully design and control is still lacking. Examples are presented to illustrate what can nanotechnology do for heterogeneous catalysis to help achieve the goal of designing catalysts for perfect selectivity in a chemical reaction. Some current state-of-the-art approaches and potential limitations are discussed. Some examples of what can catalysis do for nanotechnology are also presented. However, this aspect is much less studied, although it offers rich opportunities for the catalysis community.
Joint transmitter adaptation and power control in multi-user wireless systems with fading channels

Transmitter adaptation in conjunction with power control enables individual users in multi-user wireless systems to meet specific quality of service (QoS) constraints imposed in terms of target values for the users' signal-to-interference+noise-ratio (SINR) at their intended receiver. Existing algorithms for joint transmitter adaptation and power control require knowledge of channel state information (CSI) which is in general difficult to acquire in wireless environments that are subject to fading. In this paper we study the performance of incremental algorithms for joint transmitter adaptation and power control with fading channels by formally defining a probability of outage measure and evaluating it through Monte-Carlo simulations in specific scenarios.
Spectral beam combining of 2 μm Tm fiber laser systems

Abstract Output beams from three independently frequency-stabilized thulium master-oscillator power-amplifier fiber laser systems were spectrally combined using a plane-ruled metal diffraction grating. Two laser channels were frequency-stabilized with guided mode resonance filters and the third was stabilized using a plane-ruled metal diffraction grating. The systems had output wavelengths between 1984 and 2015 nm, each with a spectral width of 100–450 pm and output powers between 40–120 W. The combined beam had powers up to 49 W and was 32% efficient with respect to the launched pump power.
Algorithms for Capacitated Vehicle Routing

Given n identical objects (pegs), placed at arbitrary initial locations, we consider the problem of transporting them efficiently to n target locations (slots) with a vehicle that can carry at most k pegs at a time. This problem is referred to as k-delivery TSP, and it is a generalization of the traveling salesman problem. We give a 5-approximation algorithm for the problem of minimizing the total distance traveled by the vehicle. There are two kinds of transportations possible---one that could drop pegs at intermediate locations and pick them up later in the route for delivery (preemptive) and one that transports pegs to their targets directly (nonpreemptive). In the former case, by exploiting the freedom to drop, one may be able to find a shorter delivery route. We construct a nonpreemptive tour that is within a factor 5 of the optimal preemptive tour. In addition we show that the ratio of the distances traveled by an optimal nonpreemptive tour versus a preemptive tour is bounded by 4.
The hyperbolic meaning of the Milnor–Wood inequality

Abstract We introduce a notion of the twist of an isometry of the hyperbolic plane. This twist function is defined on the universal covering group of orientation-preserving isometries of the hyperbolic plane, at each point in the plane. We relate this function to a function defined by Milnor and generalised by Wood. We deduce various properties of the twist function, and use it to give new proofs of several well-known results, including the Milnor–Wood inequality, using purely hyperbolic-geometric methods. Our methods express inequalities in Milnor’s function as equalities, with the deficiency from equality given by an area in the hyperbolic plane. We find that the twist of certain products found in surface group presentations is equal to the area of certain hyperbolic polygons arising as their fundamental domains.
Where Is the Inner Edge of an Accretion Disk around a Black Hole

What is meant by the "inner edge" of an accretion disk around a black hole depends on the property that defines the edge. We discuss four such definitions, using data from recent high-resolution numerical simulations. These are (1) the "turbulence edge," where flux-freezing becomes more important than turbulence in determining the magnetic field structure; (2) the "stress edge," where plunging matter loses dynamical contact with the outer accretion flow; (3) the "reflection edge," the smallest radius capable of producing significant X-ray reflection features; and (4) the "radiation edge," the innermost place from which significant luminosity emerges. All these edges are dependent on the accretion rate and are nonaxisymmetric and time-variable. Although all are generally located in the vicinity of the marginally stable orbit, significant displacements can occur, and data interpretations placing the disk edge precisely at this point can be misleading. If observations are to be used successfully as diagnostics of accretion in strong gravity, the models used to interpret them must take careful account of these distinctions.
Winner-pay contests

We analyze winner-pay contests in which players select bids, the winner is determined probabilistically through a contest success function, and only the winner must pay her bid. We show that a pure-strategy Nash equilibrium exists and is unique under weak assumptions on the contest success function. We determine the Nash equilibrium for several examples. We also consider how equilibrium bids are influenced by private information about the value of winning the contest.
The gravitational field at spatial infinity

This paper treats the formulation of the gravitational field variables and the equations obeyed by them at spatial infinity. The variables consist of a three-dimensional tensor and a scalar, which satisfy separate field equations, which in turn can be obtained from two distinct Lagrangians. Aside from Lorentz rotations, the symmetry operations include an Abelian gauge group and an Abelian Lie group, leading to a number of conservation laws and to differential identities between the field equations.
Scholarly use of internet-based electronic resources

This research examines the use of Internet-based electronic resources (e-sources) by a group of library and information science (LIS) scholars. It focuses particularly on how scholars use, cite, and evaluate e-sources during the research process. This research also explores the problems scholars encounter and concerns they have when using e-sources for research. The following approaches were used to collect data for the investigation: (a) a longitudinal analysis of e-source citations in eight LIS journals from 1991 through 1998; (b) a survey of editors of the eight journals; and (c) a survey of 201 authors with articles to be published in the eight journals. The longitudinal analysis of e-source citations shows that there has been a notable increase in the number and proportion of authors who cite e-sources in their research articles over the 8-year period, although at the time of this study, e-sources were still cited much less frequently than print sources. This result provides empirical evidence that e-sources are increasingly used among scholars. Complementing the citation data, the results from the author survey show that e-sources are becoming an important component in scholars' research, and are serving a wide range of purposes and functions. The number of access points and self-perceived overall ability to use the Internet are identified as the two significant variables affecting frequency of e-source use. The results of this study also suggest that a limited number of criteria can be implemented in practice for scholars to evaluate electronic sources and systems. When citing e-sources, scholars consider some factors that are unique to e-sources, in addition to the factors they consider for print sources. Although the advantages of e-sources promote citing, some drawbacks of e-sources at this stage serve as a barrier. The survey of editors also reveals a lack of clearly stated editorial policies regarding citing e-sources. The major problems and concerns reported by scholars regarding using e-sources are summarized, and both the theoretical implications and practical applications of the findings are discussed.
Palladium- and Copper-Catalyzed Arylation of Carbon-Hydrogen Bonds

The transition-metal-catalyzed functionalization of C-H bonds is a powerful method for generating carbon-carbon bonds. Although significant advances to this field have been reported during the past decade, many challenges remain. First, most of the methods are substrate-specific and thus cannot be generalized. Second, conversions of unactivated (i.e., not benzylic or alpha to heteroatom) sp(3) C-H bonds to C-C bonds are rare, with most examples limited to t-butyl groups, a conversion that is inherently simple because there are no beta-hydrogens that can be eliminated. Finally, the palladium, rhodium, and ruthenium catalysts routinely used for the conversion of C-H bonds to C-C bonds are expensive. Catalytically active metals that are cheaper and less exotic (e.g., copper, iron, and manganese) are rarely used. This Account describes our attempts to provide solutions to these three problems. We have developed a general method for directing-group-containing arene arylation by aryl iodides. Using palladium acetate as the catalyst, we arylated anilides, benzamides, benzoic acids, benzylamines, and 2-substituted pyridine derivatives under nearly identical conditions. We have also developed a method for the palladium-catalyzed auxiliary-assisted arylation of unactivated sp(3) C-H bonds. This procedure allows for the beta-arylation of carboxylic acid derivatives and the gamma-arylation of amine derivatives. Furthermore, copper catalysis can be used to mediate the arylation of acidic arene C-H bonds (i.e., those with pK(a) values <35 in DMSO). Using a copper iodide catalyst in combination with a base and a phenanthroline ligand, we successfully arylated electron-rich and electron-deficient heterocycles and electron-poor arenes possessing at least two electron-withdrawing groups. The reaction exhibits unusual regioselectivity: arylation occurs at the most hindered position. This copper-catalyzed method supplements the well-known C-H activation/borylation methodology, in which functionalization usually occurs at the least hindered position. We also describe preliminary investigations to determine the mechanisms of these transformations. We anticipate that other transition metals, including iron, nickel, cobalt, and silver, will also be able to facilitate deprotonation/arylation reaction sequences.
Comparison of a very high frequency 148 MHz inductively coupled plasma to a 27 MHz ICP

Abstract Physical parameters and analytical performance are determined for an analytical ICP operated at 148 MHz, a frequency nearly three times higher than any previously reported. The iron(I) excitation temperatures are approximately 1.5 times lower and the electron densities are five times lower than at 27 MHz. The consequences of these changes are lower analyte and background continuum emission intensities, such that the signal to background ratios are decreased at the higher frequency. Freedom from interferences and working curve linearity are unaffected while ease of sample introduction is improved. A shift towards atomic emission indicates a deviation farther from LTE at 148 MHz. These effects are attributed to the decrease in skin depth with increasing frequency.
Marine Geomagnetic Anomalies

The critieron for separating the earth's main field from magnetic anomalies of crustal origin is reviewed. A concise resume of the nature of magnetic anomalies over the Mid-Atlantic Ridge, the anomalies caused by great elongated but unidentified bodies and the magnetic anomalies over seamounts is presented.
Race and the Likelihood of Managing in Major League Baseball

The impact of race on the likelihood of former Major League Baseball players becoming managers is analyzed using data from 1975 to 2008. The multivariate probit model presented controls for the effects of race, performance, star status, education, coaching, minor league managing, and playing experience. Marginally significant evidence is found that black former players are 74 % less likely to become managers at the major league level than observationally equivalent white former players. It is also observed that former catchers and shortstops are the most likely to become coaches or managers. Historically, black players have been underrepresented at the catcher and shortstop positions and overrepresented at the outfield positions. This provides evidence that historical differences in position played may have contributed to the relatively small number of black managers in Major League Baseball. Significant evidence is found that Hispanic former players are 66 and 69 % less likely to coach in the major leagues and manage in the minor leagues than observationally equivalent white former players. Coaching and minor league managing experience increase the likelihood of managing in the major leagues. Therefore, discrimination at these levels may lead to a lower number of Hispanic major league managers. It should be noted that while this study does control for education it does not directly control for English language skills. If Hispanic players are less likely to speak English than white players this may contribute to the negative effect found in this analysis. It is also shown that all star status reduces the likelihood of coaching or managing while seasons spent in the majors increase the likelihood of coaching or managing. This implies that players with long but unexceptional careers are most likely to become managers. This finding may reflect the greater opportunities available to star players after retirement.
Novel QCD Effects in the Production and Decay of Quarkonium

There are many outstanding discrepancies comparing the predictions of perturbative QCD and measurements of the rate of production and decay of heavy quark systems. The problems include the J/ψ → ρπ puzzle, leading charmed particle effects, the anomalous behavior of the heavy quark sea components of structure functions, anomalous nuclear target effects, and the large rates observed for single and double quarkonium production at large xF and large pT. I argue that these anomalies may be associated with nonperturbative effects in the higher Fock structure of hadron wavefunctions.
Adoption of Bundled Services with Network Externalities and Correlated Affinities

The goal of this article is to develop a principled understanding of when it is beneficial to bundle technologies or services whose value is heavily dependent on the size of their user base, that is, exhibits positive exernalities. Of interest is how the joint distribution, and in particular the correlation, of the values users assign to components of a bundle affect its odds of success. The results offer insight and guidelines for deciding when bundling new Internet technologies or services can help improve their overall adoption. In particular, successful outcomes appear to require a minimum level of value correlation.Categories and Subject Descriptors (2012): Networks -- Network Algorithms -- Network economics; Networks -- Network properties -- Network dynamics; Information systems -- Information systems applications -- Collaborative and social computing systems and tools; Security and privacy -- Human and societal aspects of security and privacy; Human-centered computing -- Collaborative and social computing theory, concepts and paradigms
Pharmacogenomics in cardiovascular diseases.

Abstract Considerable heterogeneity exists in the way individuals respond to medications, in terms of both efficacy and safety. Inherited differences in the absorption, metabolism, excretion, and target for drug therapy have important effects on drug efficacy and safety. Pharmacogenomics aims to discover new therapeutic targets and understand genetic polymorphisms that determine the safety and efficacy of medications. The goal of pharmacogenomics is customization of drug therapy with administration of a medication in an optimum dose that will be safe and effective with reduction in morbidity and mortality.
Chromospheric Variability in Early F-type Stars

Using precise measurements of the helium D3 line, we have searched for statistically significant variations in the strength of chromospheric activity in 13 early F-type stars and two late F-type stars. In two early F-type stars, we find short-term (hours to days) variability based on ~25 observations over the course of a week. In an additional two cases we find significant differences between observations taken years apart, but we can most likely explain this apparent long-term variation as an artifact of probable short-term variations. The evidence suggests that pure rotational modulation of discrete active regions is not responsible for the short-term variations in the early F-type stars and that either a more global process is at work or we are seeing large number of small active regions spread across the star. In contrast, the two late F-type stars in the sample show strength and/or wavelength variations that are consistent with "solar-type" activity typified by the rotational modulation of active regions. Our results suggest that variability does not cause the wide range in activity levels observed within the early F-type stars.
Automated trust negotiation using cryptographic credentials

In automated trust negotiation (ATN), two parties exchange digitally signed credentials that contain attribute information to establish trust and make access control decisions. Because the information in question is often sensitive, credentials are protected according to access control policies. In traditional ATN, credentials are transmitted either in their entirety or not at all. This approach can at times fail unnecessarily, either because a cyclic dependency makes neither negotiator willing to reveal her credential before her opponent because the opponent must be authorized for all attributes packaged together in a credential to receive any of them, or because it is necessary to disclose the precise attribute values, rather than merely proving they satisfy some predicate (such as being over 21 years of age). Recently, several cryptographic credential schemes and associated protocols have been developed to address these and other problems. However, they can be used only as fragments of an ATN process. This article introduces a framework for ATN in which the diverse credential schemes and protocols can be combined, integrated, and used as needed. A policy language is introduced that enables negotiators to specify authorization requirements that must be met by an opponent to receive various amounts of information about certified attributes and the credentials that contain it. The language also supports the use of uncertified attributes, allowing them to be required as part of policy satisfaction, and to place their (automatic) disclosure under policy control.
Coronal Structures as Tracers of Sub-Surface Processes

The solar corona &#x2013; one of the most spectacular celestial shows and yet one of the most challenging puzzles &#x2013; exhibits a spectrum of structures related to both the quiet Sun and active regions. In spite of dramatic differences in appearance and physical processes, all these structures share a common origin: they are all related to the solar magnetic field. The origin of the field is beneath the turbulent convection zone, where the magnetic field is not a master but a slave, and one can wonder how much the coronal magnetic field &#x201C;remembers&#x201D; its dynamo origin. Surprisingly, it does. We will describe several observational phenolmena that indicate a close relationship between coronal and sub-photospheric processes.
A novel clonality assay for the assessment of canine T cell proliferations

Polymerase chain reaction (PCR) based clonality assays are an important tool to differentiate neoplastic from reactive lymphocyte populations. A recent description of the canine T cell receptor γ locus identified a large number of formerly unknown genes, and determined the locus topology consisting of 8 cassettes with up to 3 variable (V) genes, 2 joining (J) genes and one constant (C) gene each. Given that these data were not available when existing canine T cell clonality assays were developed, it is likely that they will fail to detect a subset of clonal lymphocyte populations. The objective of this study was to gauge the potential of canine T cell clonality assays to detect all rearranged T cell receptor γ genes and to develop an improved clonality assay. The primer sequences of existing clonality assays were aligned to the reference sequences of all rearranged genes and genes were scored as to the likelihood of being recognized by a primer. All four assays likely recognized subgroup Vγ2 and Vγ6 genes but 3 out of 4 assays were unlikely to detect subgroup Vγ3 and Vγ7 genes. All assays likely recognized Jγx-2 genes, but only two assays were likely to detect most Jγx-1 genes. Two assays had forward primers located as close as four nucleotides to the junctional region. A new multiplex PCR was designed with all primers combined in a single tube. An alternative primer set allowed identification of variable gene usage through gene specific forward primers. The coverage of all rearranged genes facilitated the detection of multiple clonal rearrangements per neoplastic sample. The new assay detected clonal DNA at a concentration of 5% within polyclonal background but detection thresholds were dependent on the gene usage of clonal rearrangements as well as the position of the clonal peak in respect to the polyclonal background. The new multiplex assay recognized 12/12 (100%) of confirmed neoplastic samples as compared to 2/12 (17%) by an existing assay. On a series of 60 diagnostic samples the concordance rate of both assays was 41/60 (68.3%). In 14/60 (23.3%) of the cases, the new multiplex assay yielded a clonal result while the existing assay gave a non-clonal result. In 5/60 (8.3%) of cases, the new assay yielded a non-clonal result while the existing primer set gave a clonal result. These findings suggest that the new multiplex assay has an improved sensitivity over traditional assays and is suited to reduce the rate of false-negative results.
Hartley transforms over finite fields

A general framework is presented for constructing transforms in the field of the input which have a convolution-like property. The construction is carried out over finite fields, but is shown to be valid over the real and complex fields as well. It is shown that these basefield transforms can be viewed as "projections" of the discrete Fourier transform (DFT) and that they exist for all lengths N for which the DFT is defined. The convolution property of the basefield transforms is derived and a condition for such transforms to have the self-inverse property is given. Also, fast algorithms for these basefield transforms are developed, showing gains when compared to computations using the FFT. Application of the methodology to Hartley transforms over R leads to a simple derivation of fast algorithms for computing real Hartley transforms. >
Intersection theory on Shimura surfaces

Kudla has proposed a general program to relate arithmetic intersection multiplicities of special cycles on Shimura varieties to Fourier coefficients of Eisenstein series. The lowest dimensional case, in which one intersects two codimension one cycles on the integral model of a Shimura curve, has been completed by Kudla, Rapoport and Yang. In the present paper we prove results in a higher dimensional setting. On the integral model of a Shimura surface we consider the intersection of a Shimura curve with a codimension two cycle of complex multiplication points, and relate the intersection to certain cycle classes constructed by Kudla, Rapoport and Yang. As a corollary we deduce that our intersection multiplicities appear as Fourier coefficients of a Hilbert modular form of half-integral weight.
Desafios ativistas à democracia deliberativa

Neste artigo, Iris Young discute o papel dos protestos e da acao direta na democracia. Sua estrategia para avaliar os argumentos a favor e contra a acao direta e o dialogo hipotetico entre duas personagens, uma ativista e uma democrata deliberativa. Considerando como ambas lidam com os conflitos e desigualdades nas democracias e como definem a boa cidadania, ela discute os limites e potenciais dessas abordagens teoricas e praticas. Revelando conflitos que nao podem ser ultrapassados e possiveis continuidades entre elas, a autora destaca que os protestos sao tao necessarios as democracias quanto o dialogo e a persuasao. Faz, assim, a critica ao potencial paralisante da democracia deliberativa, em sua busca por consensos amplos.
Workplace drug abuse policy

An estimated 70 percent of illicit drug users are in the workforce. This paper studies workplace policies relating to drug abuse treatment and testing in a labor market with asymmetric information about worker proclivities to abuse drugs and to incur costs of workplace accidents. Drug abuse has a moral hazard component related to worker choice of treatment or other deterrent activities, and a selection component related to drug testing. We characterize the type and frequency of workers treated and tested in labor market equilibrium. Labor market incentives will generally lead to too little treatment and too much testing.
Some results in combustion generated noise

This paper contains some analytical results aimed toward understanding of prior experimental results in noise generated by the turbulent combustion process. It is proven that regardless of the turbulence structure the far field sound pressure is directly proportional to the first Eulerian time derivative of the chemical reaction rate integrated over the reacting volume. The characteristics of the correlation function for this reaction rate time derivative are investigated through elementary reasoning for several simple premixed turbulent flame models. Scaling rules for the sound power output are obtained and compared with experiment. The directional characteristics of the radiated sound are investigated. It is shown that preferred directionality due to the source behavior is minor and that observed directionality must be explained by other phenomena such as refraction at temperature discontinuities.
Multichannel image deconvolution by total variation regularization

The total variational (TV) regularization method was first proposed for gray scale images and was extended for vector valued images. In this work, we apply the TV regularization method to solve the multichannel image deconvolution problem. The motivation for regularizing with the TV norm is that it is extremely effective for recovering edges of images. In this paper, a fast iterative method is developed to solve the deconvolution problem. Our method involves solving linear systems and the conjugate gradient method is applied in which Fourier transform type preconditioners are used to speed up the convergence rate. Numerical experiments demonstrate the effectiveness of the TV regularization method. In this paper, we present some preliminary results on multichannel blind deconvolution with TV regularization.
Robustifying multivariate trend tests to nonstationary volatility

Abstract This article studies inference of multivariate trend model when the volatility process is nonstationary. Within a quite general framework we analyze four classes of tests based on least squares estimation, one of which is robust to both weak serial correlation and nonstationary volatility. The existing multivariate trend tests, which either use non-robust standard errors or rely on non-standard distribution theory, are generally non-pivotal involving the unknown time-varying volatility function in the limit. Two-step residual-based i.i.d. bootstrap and wild bootstrap procedures are proposed for the robust tests and are shown to be asymptotically valid. Simulations demonstrate the effects of nonstationary volatility on the trend tests and the good behavior of the robust tests in finite samples.
Universal deformation rings and fusion

Abstract We study in this paper the extent to which one can detect fusion in certain finite groups Γ from information about the universal deformation rings R ( Γ , V ) of absolutely irreducible F p Γ -modules V. The Γ we consider are extensions of either abelian or dihedral groups G of order prime to p by an elementary abelian p-group of rank 2.
Causal inference from indirect experiments

An indirect experiment is a study in which randomized control is replaced by randomized encouragement, that is, subjects are encouraged, rather than forced, to receive a given treatment program. The purpose of this paper is to bring to the attention of experimental researchers simple mathematical results that enable us to assess, from indirect experiments, the strength with which causal influences operate among variables of interest. The results reveal that despite the laxity of the encouraging instrument, data from indirect experimentation can yield significant and sometimes accurate information on the impact of a program on the population as a whole, as well as on the particular individuals who participated in the program.
Cooperative protofilament switching emerges from inter-motor interference in multiple-motor transport

Within living cells, the transport of cargo is accomplished by groups of molecular motors. Such collective transport could utilize mechanisms which emerge from inter-motor interactions in ways that are yet to be fully understood. Here we combined experimental measurements of two-kinesin transport with a theoretical framework to investigate the functional ramifications of inter-motor interactions on individual motor function and collective cargo transport. In contrast to kinesin's low sidestepping frequency when present as a single motor, with exactly two kinesins per cargo, we observed substantial motion perpendicular to the microtubule. Our model captures a surface-associated mode of kinesin, which is only accessible via inter-motor interference in groups, in which kinesin diffuses along the microtubule surface and rapidly “hops” between protofilaments without dissociating from the microtubule. Critically, each kinesin transitions dynamically between the active stepping mode and this weak surface-associated mode enhancing local exploration of the microtubule surface, possibly enabling cellular cargos to overcome macromolecular crowding and to navigate obstacles along microtubule tracks without sacrificing overall travel distance.
Two-loop computation of a finite volume running coupling on the lattice

In pure SU(2) gauge theory we compute the two-loop coefficient in the relation between the lattice bare coupling and the running coupling defined through the Schrodinger functional. This result is required to relate the latter to the MS ¯ − coupling in our programme to compute α. In addition it allows us to implement O(a) improvement of the Schrodinger functional to two-loop order. The two-loop β-function is verified in a perturbative computation on the lattice, and the behavior of expansions in the standard and in the Parisi-improved bare couplings are investigated beyond one loop.
Homoallylically controlled epoxidation of Δ4-cis-1,2-disubstituted cyclohexenes

Abstract Stereochemical control during the epoxidation of cis -1-[N-Cbz]-2-[hydroxymethyl]-cyclohex-4-enes with MCPBA is dependent on hydroxyl functionalization which apparently determines ring conformation. Unprotected or acetate-derivatized compounds afford exclusively syn epoxide products. Silyl ether protected analogs furnish predominantly products derived from anti delivery of oxygen. Respective 2-carbomethoxy and benzyl carbamate-protected aminomethyl derivatives show stereospecificity similar to the free hydroxyl and acetate-protected substrates.
INSTABILITY OF THE GRAVITATIONAL N-BODY PROBLEM IN THE LARGE-N LIMIT

We use a systolic N-body algorithm to evaluate the linear stability of the gravitational N-body problem for N up to 1.3 × 105, 2 orders of magnitude greater than in previous experiments. For the first time, a clear N-dependence of the perturbation growth rate is seen, μe ~ ln N. The e-folding time for N = 105 is roughly 1/20 of a crossing time.
Spatially resolved In and As distributions in InGaAs/GaP and InGaAs/GaAs quantum dot systems

InGaAs quantum dots (QDs) on GaP are promising for monolithic integration of optoelectronics with Si technology. To understand and improve the optical properties of InGaAs/GaP QD systems, detailed measurements of the QD atomic structure as well as the spatial distributions of each element at high resolution are crucial. This is because the QD band structure, band alignment, and optical properties are determined by the atomic structure and elemental composition. Here, we directly measure the inhomogeneous distributions of In and As in InGaAs QDs grown on GaAs and GaP substrates at the nanoscale using energy dispersive x-ray spectral mapping in a scanning transmission electron microscope. We find that the In distribution is broader on GaP than on GaAs, and as a result, the QDs appear to be In-poor using a GaP matrix. Our findings challenge some of the assumptions made for the concentrations and distributions of In within InGaAs/GaAs or InGaAs/GaP QD systems and provide detailed structural and elemental information to modify the current band structure understanding. In particular, the findings of In deficiency and inhomogeneous distribution in InGaAs/GaP QD systems help to explain photoluminescence spectral differences between InGaAs/GaAs and InGaAs/GaP QD systems.
Compact, Low Profile, Common Aperture Polarization, and Pattern Diversity Antennas

This paper presents compact and low profile two-port antennas that can provide polarization or pattern diversity schemes from a common aperture. The proposed antennas make use of a novel small microstrip antenna topology with an open area at its waist. The two sections of the small-size microstrip antenna are connected through a magnetic coupling mechanism facilitated by two vertical metallic strips connecting the top plates to the ground plane. This allows for placement of another small antenna element within the same aperture having either polarization or pattern that is orthogonal to the microstrip antenna with low envelope correlation. Topologies of polarization and pattern-diversity antennas are optimized for size reduction and minimum envelope correlation. Although the proposed diversity antenna consists of two antenna elements with different polarizations or radiation patterns, they just occupy about 30% of the area of a conventional microstrip antenna over the same substrate. It is shown that the envelope correlation between radiation patterns of the two antenna elements is lower than -30 dB over the 10-dB return loss bandwidth of the proposed antenna.
De Haas-Van Alphen effect in silicon inversion layers

The dHvA effect was observed in a Si inversion layer by a modulation technique for constant magnetic field up to 15 T. The expected periodic spikes in dMdn between Landau levels were discerned. However, the predicted quantum plateaus with step of hem∗c are not yet observed.
Physics at an upgraded proton driver at Fermilab

The accelerator-based particle physics program in the US is entering a period of transition. This is particularly true at Fermilab which for more than two decades has been the home of the Tevatron Proton-Antiproton Collider, the World's highest energy hadron collider. In a few years time the energy frontier will move to the LHC at CERN. Hence, if an accelerator-based program is to survive at Fermilab, it must evolve. Fermilab is fortunate in that, in addition to hosting the Tevatron Collider, the laboratory also hosts the US accelerator-based neutrino program. The recent discovery that neutrino flavors oscillate has opened a new exciting world for us to explore, and has created an opportunity for the Fermilab accelerator complex to continue to address the cutting-edge questions of particle physics beyond the Tevatron Collider era. The presently foreseen neutrino oscillation experiments at Fermilab (MiniBooNE [1] and MINOS [2]) will enable the laboratory to begin contributing to the Global oscillation physics program in the near future, and will help us better understand the basic parameters describing the oscillations. However, this is only a first step. To be able to pin down all of the oscillation parameters, and hopefully make new discoveries along the way,more » we will need high statistics experiments, which will require a very intense neutrino beam, and one or more very massive detectors. In particular we will require new MW-scale primary proton beams and perhaps ultimately a Neutrino Factory [3]. Plans to upgrade the Fermilab Proton Driver are presently being developed [4]. The upgrade project would replace the Fermilab Booster with a new 8 GeV accelerator with 0.5-2 MW beam power, a factor of 15-60 more than the current Booster. It would also make the modifications needed to the Fermilab Main Injector (MI) to upgrade it to simultaneously provide 120 GeV beams of 2 MW. This would enable a factor of 5-10 increase in neutrino beam intensities at the MI, while also supporting a vigorous 8 GeV fixed-target program. In addition, a Proton Driver might also serve as a stepping-stone to future accelerators, both as an R&D test bed and as an injector, with connections to the Linear Collider, Neutrino Factories, and a VLHC. Hence, although neutrino physics would provide the main thrust for the science program at an upgraded Fermilab proton source, the new facility would also offer exciting opportunities for other fixed-target particle physics (kaons, muons, neutrons, antiprotons, etc.) and a path towards new accelerators in the future.« less
Ab Initio Molecular Orbital Calculations of Ring Opening of Cyclopropylcarbinyl Radicals

Ab initio molecular orbital calculations have been performed on the ring-opening reactions of the cyclopropylcarbinyl radical and analogs containing methyl substitution on the ring. The barrier height and heat of reaction for the cyclopropylcarbinyl radical ring opening calculated at the G2 level of theory are in good agreement with experiment. Barrier heights for the ring opening of substituted cyclopropylcarbinyl radicals and relative rate constants were computed at HF, UMP2, and PMP2 levels of theory using the 6-31G* basis set. The calculated relative rates are in good agreement with the experimental data available, and the trends in the kinetics can be explained primarily by steric interactions.
Analysis of multithreaded microprocessors under multiprogramming

We examine multithreading to improve uniprocessor cost/performance on multiple processes. Processor utilization and cache behavior are studied analytically and under simulation by interleaving reference traces to model timesharing and multithreading. Multithreading a small number of threads is superior with large on-chip caches and significant memory latency. The switch need not be extremely fast. Surprisingly, miss ratios under multithreading may be lower than under timesharing, because switch-on-miss multithreading favors processes with better cache behavior.
Localization and entanglement of two interacting electrons in a quantum-dot molecule

The localization of two interacting electrons in a coupled-quantum-dots semiconductor structure is demonstrated through numerical calculations of the time evolution of the two-electron wave function including the Coulomb interaction between the electrons. The transition from the ground state to a localized state is induced by an external, time-dependent, uniform electric field. It is found that while an appropriate constant field can localize both electrons in one of the wells, oscillatory fields can induce roughly equal probabilities for both electrons to be localized in either well, generating an interesting type of localized and entangled state. We also show that shifting the field suddenly to an appropriate constant value can maintain in time both types of localization.
Lefschetz properties and basic constructions on simplicial spheres

The well known g-conjecture for homology spheres follows from the stronger conjecture that the face ring over the reals of a homology sphere, modulo a linear system of parameters, admits the strong-Lefschetz property. We prove that the strong-Lefschetz property is preserved under the following constructions on homology spheres: join, connected sum, and stellar subdivisions. The last construction is a step towards proving the g-conjecture for piecewise-linear spheres.
The discourse functions of Italian subjects: a centering approach

This paper examines the discourse functions that different types of subjects perform in Italian within the centering framework (Grosz et al., 1995). I build on my previous work (Di Eugenio, 1990) that accounted for the alternation of null and strong pronouns in subject position. I extend my previous analysis in several ways: for example, I refine the notion of CONTINUE and discuss the centering functions of full NPs.
Quantum-mechanical interpretation of time-dependent density-functional theory☆

Abstract In this paper we derive the differential virial theorem for both time-dependent (TD) Schrodinger theory and Kohn-Sham (KS) density-functional theory. As such we obtain an exact integral expression for the TD electron-interaction potential of KS theory that is independent of the choice of action. The expression, valid for general TD phenomena other than the ionization or scattering process, is afforded the physical interpretation at each instant of time as being the work done to move an electron in a conservative field. The field is a sum of four component fields representative of Pauli and Coulomb correlations, correlation-kinetic effects, and as discovered here, correlations due to the difference in current densities of the KS and Schrodinger systems. The interpretation further reduces to that for the corresponding electron-interaction potential of stationary-state KS theory for time-independent external potentials.