cssi/SciSciGPT-SciSciNet huggingface dataset:
Time consistency of optimal monetary and fiscal policy in a small open economy

Abstract This paper characterizes conditions under which optimal monetary and fiscal policy is time consistent in a stylized small open economy with a flexible foreign exchange rate regime. It shows that these conditions depend on the way in which leisure is assumed to enter preferences and/or on the process which productivity is assumed to follow. This paper further argues that these conditions may fail to be sufficient if the small open economy implements a fixed foreign exchange rate regime. Thus, a credible fixed exchange rate regime does not necessarily help render optimal policy time consistent.
AN ELEMENTARY PROOF OF THE RESTRICTED INVERTIBILITY THEOREM

We give an elementary proof of a generalization of Bourgain and Tzafriri’s Restricted Invertibility Theorem, which says roughly that any matrix with columns of unit length and bounded operator norm has a large coordinate subspace on which it is well-invertible. Our proof gives the tightest known form of this result, is constructive, and provides a deterministic polynomial time algorithm for finding the desired subspace.
From Brownian-Time Brownian Sheet to a Fourth Order and a Kuramoto–Sivashinsky-Variant Interacting PDEs Systems

We introduce n-parameter ℝ d -valued Brownian-time Brownian sheet (BTBS): a Brownian sheet where each “time” parameter is replaced with the modulus of an independent Brownian motion. We then connect BTBS to a new system of n linear, fourth order, and interacting PDEs and to a corresponding fourth order interacting nonlinear PDE. The coupling phenomenon is a result of the interaction between the Brownian sheet, through its variance, and the Brownian motions in the BTBS; and it leads to an intricate, intriguing, and random field generalization of our earlier Brownian-time-processes (BTPs) connection to fourth order linear PDEs. Our BTBS does not belong to the classical theory of random fields; and to prove our new PDEs connections, we generalize our BTP approach in [4, 5] and we mix it with the Brownian sheet connection to a linear PDE system, which we also give along with its corresponding nonlinear second order PDE and a 2nth order linear PDE that we also connect to Brownian sheet. In addition, we introdu...
Syntheses of nitrogen heterocycles by means of amine-directed carbonylation and hydrocarbonylation

Abstract Amine-directed carbonylation of 2-allylpiperidine ( 5 ) gives 8-methyl-1-azabicyclo[4.3.0]nonan-9-one ( 7 ) with extremely high regio-and stereosel
A facile route to homochiral sulfoxides

Abstract Biocatalytic resolutions of methyl sulfinylacetates fford sulfoxides (R)-( 1 ) - ( 6 ) in very high optical yields; the products have been used in a systematic study of the “SPAC” reaction, an asymmetric synthesis of γ-hydroxy-α,β-unsaturated esters.
Enhanced gauge symmetry in type II and F-theory compactifications: Dynkin diagrams from polyhedra

We explain the observation by Candelas and Font that the Dynkin diagrams of non-abelian gauge groups occurring in type IIA and F-theory can be read off from the polyhedron Δ∗ that provides the toric description of the Calabi-Yau manifold used for compactification. We show how the intersection pattern of toric divisors corresponding to the degeneration of elliptic fibers follows the ADE classification of singularities and the Kodaira classification of degenerations. We treat in detail the cases of elliptic K3 surfaces and K3 fibered threefolds where the fiber is again elliptic. We also explain how even the occurrence of monodromy and non-simply laced groups in the latter case is visible in the toric picture. These methods also work in the fourfold case.
Processing Ranger and Mariner Photography

A discussion of the "Lunar Television Image Converter" (Lunar-TIC) will be presented. This is the system utilized for the digital processing of the RANGER and the MARINER pictures. Digitizing requirements and 'tradeoffs' will be covered as they apply to this process which employs a magnetic analog tape as the data source, converts the data for processing in a 7094 computer and then converts it to picture form. Some of the RANGER and MARINER pictures which have been processed in the IPL digital computer will be shown and the various techniques used will be discussed. Samples will also be shown of the capability of Lunar-TIC to scan, digitize, and reconstruct photographic transparencies.
Extramammary paget's disease of the vulva

Fourteen patients with extramammary Paget's disease of the vulva treated at Yale-New Haven Medical Center from 1982 through 1993 were reviewed to evaluate the accuracy of methods used to delineate surgical margins and to determine if radical operations or surgical margin status was associated with likelihood of recurrence. These 14 patients underwent at total of 25 operations for extramammary Paget's disease. In 8 operations, a total of 44 separate frozen-section biopsies were performed to determine extent of disease with a mean of 5.5 biopsies per patient. Visual judgment alone was used to determine margin status in 17 operations. The ability to delineate free surgical margins on permanent sections was not different, whether judged visually or by frozen-section analysis. Frozen-section analysis was misleading in 3/8 (37.5%) cases, while visual judgment was in error in 6/17 (35%) cases. Moreover, permanent margin status was not found to be predictive of disease recurrence. Two of 5 (40%) patients with positive margins recurred after initial surgery compared with 3 of 9 (33%) patients with negative margins. Of the 14 primary operations, there were 8 wide local excisions, 3 simple vulvectomies, and 3 modified radical vulvectomies. The radicality of the operation as initial treatment did not statistically correlate with disease recurrence.
THE HOMFLY POLYNOMIAL FOR LINKS IN RATIONAL HOMOLOGY 3-SPHERES

Abstract We use intrinsic 3-manifold topology to construct formal power series invariants for links in a large class of rational homology 3-spheres, which generalizes the 2-variable Jones polynomial (HOMFLY). As a consequence, we show that a certain completion of the HOMFLY skein module of a homotopy 3-sphere is isomorphic to that of the genuine 3-sphere.
Hydrogen bonds in molecular assemblies of natural, synthetic and ‘designer’ peptides

Abstract The initial folding of the backbone of peptides and the subsequent arrangement of the molecules into a supramolecular assembly is primarily associated with NH⋯OC hydrogen bonds where the N⋯O distance is 2.8–3.0 A and to a lesser extent with water molecules that act as donors and acceptors for hydrogen bonds, both within a peptide molecule and between peptide molecules. In helical peptides, the transition between 3 10 -helices (with 10 atoms in a hydrogen-bond ring) and α-helices (with 13 atoms in a hydrogen bond ring) merely requires a shift from one CO to an adjacent CO and is often quite facile. Among examples to be presented are two crystal structures of a heptapeptide wherein the helices are the 3 10 -type when the amino end group is Boc and the α-type when the amino end is Ac. A new type of regular helix was synthesized and characterized by x-ray diffraction analysis using β-amino acid residues, rather than α-amino acid residues. The new helix was named β-foldamer and it is characterized by 14-atom hydrogen-bond rings rather than the 13-atom rings present in α-helices. An NH group will not always form a hydrogen bond with any CO (or H 2 O) that is present in a crystal. Examples are shown in which the N⋯O distance is > 3.30 A and also examples of structures in which there is no O acceptor or any other kind of acceptor within possible reach of an available NH. Assemblies with ‘free’ NH groups are presented in which there is no possibility for a ‘cooperative hydrogen bond’ between NH and the center of a phenyl group, although other structures with a close NH⋯phenyl approach will be discussed.
How important is global industry shock in explaining the relative performance of global industries

Purpose – The purpose of this paper is to examine the effects of exchange rate and global industry shocks on the relative performance of global industries.Design/methodology/approach – In addition to SUR approach, we also use GARCH approach to control for heteroskedasticity.Findings – Using industry data from Japan and the USA, the authors find that although both exchange rate and global industry shocks are statistically significant in explaining the performance of these industries relative to their domestic markets, economically the global industry shock plays the major role in determining this performance.Research limitations/implications – The authors' findings are only based on two countries, the USA and Japan, so future researchers can use the authors' empirical models to test if their results hold using data from other countries.Practical implications – Investors should focus more on the performance of global industries instead of exchange rate changes when creating their portfolios.Originality/valu...
Homology and derived series of groups II: Dwyer’s Theorem

We give new information about the relationship between the low-dimensional homology of a space and the derived series of its fundamental group. Applications are given to detecting when a set of elements of a group generates a subgroup “large enough” to map onto a nonabelian free solvable group, and to concordance and grope cobordism of classical links. We also greatly generalize several key homological results employed in recent work of Cochran‐Orr‐Teichner in the context of classical knot concordance. In 1963 J Stallings established a strong relationship between the low-dimensional homology of a group and its lower central series quotients. In 1975 W Dwyer extended Stallings’ theorem by weakening the hypothesis on H2 . In 2003 the second author introduced a new characteristic series, G .n/ H , associated to the derived series, called the torsion-free derived series. The authors previously established a precise analogue, for the torsion-free derived series, of Stallings’ theorem. Here our main result is the analogue of Dwyer’s theorem for the torsion-free derived series. We also prove a version of Dwyer’s theorem for the rational lower central series. We apply these to give new results on the Cochran‐Orr‐Teichner filtration of the classical link concordance group. 57M07; 20J06, 55P60
Recruiting Agricultural Economics Graduate Students: Student Demand for Program Attributes

We use data from an Internet and traditional print mail survey to determine student demand for graduate program attributes. Results reveal that students value graduate program ranking more than stipend level, geographic location, or office/computer facilities. Higher ranked programs, as a whole, may be able to offer substantially lower stipends to students and remain competitive with lower ranked programs. Results also suggest that students might be willing to accept higher stipends or office space to attend lower ranked schools. The results may provide graduate program leaders with information to improve their recruitment efforts and/or potentially reduce graduate program expenditures.
Substituent effects on the gas-phase acidity of silane

In a previous paper, the gas-phase acidities of XH{sub n} compounds (X = C, N, O, F, Si, P, S, Cl) were predicted with ab initio wave functions. At the MP4{sup 2} level of theory with extended basis sets acidities for these species were determined to be within 2 kcal/mol of experimental value. In the present work, with 6-31G(d) geometries and full MP4/MC-311++G{sup 6}(3df,2pd) energies, the effects of CH{sub 3}, NH{sub 2}, OH, F, SiH{sub 3}, PH{sub 2}, SH, and Cl on the gas-phase acidity of silane are examined. Only a few related calculations have been carried out. All calculations were performed with Gaussian86, and all structures were verified as minima by diagonalizing the analytically determined hessians. Only the valence electrons were correlated in the perturbation theory calculations.
A Mechanism for Land–Atmosphere Feedback Involving Planetary Wave Structures

While the ability of land surface conditions to influence the atmosphere has been demonstrated in various modeling and observational studies, the precise mechanisms by which land-atmosphere feedback occurs are still largely unknown particularly the mechanisms that allow land moisture state in one region to affect atmospheric conditions in another. Such remote impacts are examined here in the context of atmospheric general circulation model (AGCM) simulations, leading to the identification of one potential mechanism: the phase-locking and amplification of a planetary wave through the imposition of a spatial pattern of soil moisture at the land surface. This mechanism, shown here to be relevant in the AGCM, apparently also operates in nature, as suggested by supporting evidence found in reanalysis data.
Gravitational waves, black holes and cosmic strings in cylindrical symmetry

Gravitational waves in cylindrically symmetric Einstein gravity are described by an effective energy tensor with the same form as that of a massless Klein-Gordon field, in terms of a gravitational potential generalizing the Newtonian potential. Energy-momentum vectors for the gravitational waves and matter are defined with respect to a canonical flow of time. The combined energy-momentum is covariantly conserved, the corresponding charge being the modified Thorne energy. Energy conservation is formulated as the first law expressing the gradient of the energy as work and energy-supply terms, including the energy flux of the gravitational waves. Projecting this equation along a trapping horizon yields a first law of black-hole dynamics containing the expected term involving area and surface gravity, where the dynamic surface gravity is defined with respect to the canonical flow of time. A first law for dynamic cosmic strings also follows. The Einstein equation is written as three wave equations plus the first law, each with sources determined by the combined energy tensor of the matter and gravitational waves.
The Origin of the Young Stars in the Nucleus of M31

The triple nucleus of M31 consists of a population of old red stars in an eccentric disk (P1 and P2) and another population of younger A stars in a circular disk (P3) around M31’s central supermassive black hole (SMBH). We argue that P1 and P2 determine the maximal radial extent of the younger A star population and provide the gas that fueled the starburst that generated P3. The eccentric stellar disk creates an m = 1 non-axisymmetric perturbation to the potential. This perturbed potential drives gas into the inner parsec around the SMBH, if the pattern speed of the eccentric stellar disk is p . 3 − 10kms −1 pc −1 . We show that stellar mass loss from P1 and P2 is sufficient to create a gravitationally unstable gaseous disk of ∼ 10 5 M⊙ every 0.1 −1 Gyrs, consistent with the 200 Myr age of P3. Similar processes may act in other systems to produce very compact nuclear starbursts. Subject headings: galaxies: individual (M31) – galaxies: nuclei – galaxies: starburst
A Geometric View of Rational Landen Transformations

In this paper, a geometric interpretation is provided of a new rational Landen transformation. The convergence of its iterates is also established.
Does federal funds futures rate contain information about the treasury bill rate

In this article, we use high-frequency daily data to examine the dynamic relationship between the federal funds futures rate and the 3-month treasury (T)-bill rate. Our results show that 1-month federal funds futures rate is co-integrated with the 3-month T-bill rate, and thus move together in the long run. We find that any deviation of the 1-month federal funds futures rate and the T-bill rate from their long-run equilibrium is corrected by the subsequent movements in both federal funds futures rate and T-bill rate. Decomposing the federal funds futures rate and the T-bill rate into a trend and cycle using the multivariate Beveridge–Nelson methodology, we find that there was a big positive cycle in the federal funds futures rate before 2008 implying a future downward movement in federal funds futures rate. We also find a negative cycle in T-bill market during the financial crisis implying that the yield on T-bill was below the long-run trend.
Total synthesis of marinomycins A-C and of their monomeric counterparts monomarinomycin A and iso-monomarinomycin A.

Marinomycins A−C (1−3), and their monomeric analogues monomarinomycin A (m-1) and iso-monomarinomycin A (m-2), were synthesized by a convergent strategy from key building blocks ketophosphonate 5, aldehyde 6, and dienyl bromide carboxylic acid 7. The first attempt to construct marinomycin A [1, convertible to marinomycins B (2) and C (3) by light] by direct Suzuki-type dimerization/cyclization of boronic acid dienyl bromide 4 led to premature ring closure to afford, after global desilylation, monomarinomycin A (m-1) and iso-monomarinomycin A (m-2) in good yield and only small amounts (≤2%) of the desired product. A subsequent stepwise approach based on Suzuki-type couplings improved considerably the overall yield of marinomycin A (1), and hence of marinomycins B (2) and C (3). Alternative direct dimerization approaches based on the Stille and Heck coupling reactions also led to monomarinomycins A (m-1 and m-2), but failed to deliver useful amounts of marinomycin A (1).
Line Asymmetry of Solar p-Modes: Properties of Acoustic Sources

The observed solar p-mode velocity power spectra are compared with theoretically calculated power spectra over a range of mode degree and frequency. The shape of the theoretical power spectra depends on the depth of acoustic sources responsible for the excitation of p-modes and also on the multipole nature of the source. We vary the source depth to obtain the best fit to the observed spectra. We find that quadrupole acoustic sources provide a good fit to the observed spectra provided that the sources are located between 700 and 1050 km below the top of the convection zone. The dipole sources give a good fit for a significantly shallower source, with a source depth of between 120 and 350 km. The main uncertainty in the determination of depth arises because of poor knowledge of the nature of power leakages from modes with adjacent degrees and the background in the observed spectra.
Sonoporation of monolayer cells by diagnostic ultrasound activation of contrast-agent gas bodies.

Human (A431 epidermoid carcinoma) cells were grown as monolayers on 5 microm thick Mylar sheets, which formed the upper window for a 1-mm thick, 23-mm diameter disc-shaped exposure chamber. A 3.5-MHz curved linear-array transducer was aimed upward at the chamber, 7 cm away, in a 37 degrees C water bath. The chamber contained phosphate-buffered saline (PBS) with 10 mg/mL fluorescent dextran and 1% Optison ultrasound (US) contrast agent. Significant fluorescent cell counts, indicative of membrane damage (i.e., sonoporation), up to about 10% of cells within a 1-mm diameter field of view, were noted for spectral Doppler and two-dimensional (2-D) scan mode with or without a tissue-mimicking phantom. The effect was only weakly dependent on pulse-repetition frequency or exposure duration, but was strongly dependent on contrast agent concentration below 2%. Thus, diagnostic US activation of contrast-agent gas bodies can produce cell membrane damage.
Computing Dirichlet character sums to a power-full modulus

Abstract The Postnikov character formula is used to express large portions of a Dirichlet character sum in terms of quadratic exponential sums. The quadratic sums are then computed using an analytic algorithm previously derived by the author. This leads to a power-saving if the modulus is smooth enough. As an application, a fast, and potentially practical, method to compute Dirichlet L-functions with complexity exponent 1/3 for smooth enough moduli is derived.
Ensuring predictable contact opportunity for scalable vehicular internet access on the go

With increasing popularity of media-enabled hand-helds and their integration with the in-vehicle entertainment systems, the need for high-data-rate services for mobile users on the go is evident. This ever-increasing demand of data is constantly surpassing what cellular networks can economically support. Large-scale wireless local area networks (WLANs) can provide such a service, but they are expensive to deploy and maintain. Open WLAN access points, on the other hand, need no new deployments, but can offer only opportunistic services, lacking any performance guarantees. In contrast, a carefully planned sparse deployment of roadside WiFi provides an economically scalable infrastructure with quality-of-service assurance to mobile users. In this paper, we present a new metric, called Contact Opportunity, to closely model the quality of data service that a mobile user might experience when driving through the system. We then present efficient deployment algorithms for minimizing the cost for ensuring a required level of contact opportunity. We further extend this concept and the deployment techniques to a more intuitive metric---the average throughput---by taking various dynamic elements into account. Simulations over a real road network and experimental results show that our approach achieves significantly better cost versus throughput tradeoff in both the worst case and average case compared to some commonly used deployment algorithms.
Surfaces for computer-aided aircraft design.

A simple but general way is described to define freeform surfaces such as airplane fuselages, wings, fillets, ducts, and other shapes by means of man-machine graphical interaction with a computer. In the past, much attention has been directed toward fitting mathematical functions to surfaces already defined by a mesh of points. The present discussion centers around the philosophy that in the preliminary phase of shape description the computer's aid should be enlisted at the very beginning and that in this way the results of preliminary surface design become the first "master dimensions" of the airplane directly, without the necessity of refairing or other subsequent treatment. These surfaces and curve formulations can be incorporated into computer data structures, where they will serve as the skeleton upon which other associated data can be hung, such as velocity fields, pressures, temperatures, forces, and other physical quantities that arise in connection with analytical and design procedures.
Pebble game algorithms and sparse graphs

A multi-graph $G$ on n vertices is $(k,l)$-sparse if every subset of $n'≤n$ vertices spans at most $kn'-l$ edges, $0 ≤l < 2k$. $G$ is tight if, in addition, it has exactly $kn - l$ edges. We characterize $(k,l)$-sparse graphs via a family of simple, elegant and efficient algorithms called the $(k,l)$-pebble games. As applications, we use the pebble games for computing components (maximal tight subgraphs) in sparse graphs, to obtain inductive (Henneberg) constructions, and, when $l=k$, edge-disjoint tree decompositions.
Development of an Automated SMILES Pattern Matching Program To Facilitate the Prediction of Thermophysical Properties by Group Contribution Methods

Group-contribution methods produce estimates of thermophysical properties from correlations that include summative contributions for the functional groups that make up a molecule. Accurately dividing or parsing a molecule into its constituent functional groups, as intended by the authors of group-contribution methods, can be tedious and error prone. An automated parsing algorithm, which accepts SMILES formulas of compounds and accurately parses these into constituent functional groups, has been developed to facilitate the use, comparison, and development of group-contribution methods. The algorithm is described with particular attention to the difficulties inherent in parsing large, multiring compounds. The methodology will be useful to others who are developing, testing, and using prediction techniques.
Redox-active radical scavenging nanomaterials

Reactive oxygen and nitrogen species play a critical role in many degenerative diseases and in aging. Nanomaterials, especially modified fullerenes and cerium oxide nanoparticles, have been shown to effectively protect mammalian cells against damage caused by increased reactive oxygen or nitrogen species, likely through their direct reaction with superoxide radical, since each of these materials has been shown to act as effective superoxide dismutase mimetics in vitro. This critical review discusses the chemistry of these nanomaterials and the context in which their radical scavenging activities have been studied in biological model systems. Current studies are focused on determining the uptake, metabolism, distribution, toxicity and fate of these nanomaterials in cell and animal model systems. Ultimately if shown to be safe, these nanomaterials have the potential to be used to reduce the damaging effects of radicals in biological systems (101 references).
Rare-earth elements in groundwaters from the Osamu Utsumi mine and Morro do Ferro analogue study sites, Poços de Caldas, Brazil

Abstract Data are presented on rare-earth elements (REE) in prefiltered ( 450 nm) from the Osamu Utsumi uranium mine and the Morro do Ferro thorium-REE-deposit. Groundwaters from both sites typically contain between 1–50 μg/l of total REE, but can reach values of up to 160 μg/l in the deepest borehole F4 (U-Mine: 150–415 m). Even higher REE concentrations of up to 29 mg/l were measured in acidic, sulfate-rich near-surface waters of the same site. The chondrite-normalized REE patterns in deeper, more reducing groundwaters and in their corresponding suspended particle fractions are similar to those observed in the bedrock (phonolites), indicating that bedrock leaching and secondary mineral sorption occurred without significant fractionation between these elements, in accordance with the only small variations in the stability constants of the expected REE-sulfate complexes in these waters. Groundwaters from the unsaturated zone of both sites show a very characteristic cerium depletion (less pronounced than that observed in the corresponding suspended particulate fractions), which is most probably related to the oxidation of Ce (III) under the prevailing E h -conditions of these waters (600 to 800 mV), and to sorption/precipitation reactions of the much less soluble Ce(IV) species. Coarse particulate matter (>450 nm ), composed mainly of amorphous ferric hydrous oxides, has a strong capacity for sorption of REE. This is shown by its very high REE concentrations, in some boreholes > 8,000 μg/g (total REE), and by the calculated association ratios R a (ml/g), which are in the order of 10 5 to 10 6 . The implications of these findings for the migration behavior of REE in both environments are discussed.
Myth and Reality in Chinese Financial Cliques in 1936

Much of current scholarly work argues that China and Chinese communities are distinguished by a culturally specific and unique pattern of networking based on personal relations (guanxi), but there is little agreement about whether such personal relations produce discrete factions or more disbursed, weblike connections. The literature on banking networks is similarly unclear, and most discussion has focused on regional groups, such as a clique made up of natives from Zhejiang and Jiangsu provinces, or shared professional values among bankers. None of these approaches adequately describes actual connections, and this case study provides a new and empirically broad approach that applies tools of network analysis to interlocking bank directorships in 1936. This analysis shows the existence of twenty-four isolated banks; three very small, discrete, and regionally based groups; and one huge, diffuse, and weblike bank network that included virtually all Chinese bank assets and extended to most of China's economically developed regions. This network had a multicenter core made up of densely linked large banks and a number of small start-ups associated with prominent individuals. Diffuse connections also characterized networks of individual bankers, though dense ties existed either among the most important bankers who each sat on numerous boards of directors (suggesting associations based on business ties, professional interests, and the importance of banks) or among individuals who shared common native place, defined at the level of adjacent counties (suggesting the simultaneous existence of strong but very local guanxi ties). In the end, bank networks arose as much from historical contingency as from cultural predisposition.
Antitumor phospholipids: A one-pot introduction of a phosphocholine moiety into lipid hydroxy acceptors

Abstract A high-yielding, 3-step, one-pot conversion of lipid hydroxy acceptors 2 into clinically useful alkylphosphocholines 1 is reported. Reaction of 2 with ethylene chlorophosphite gave phosphite 3 , which underwent oxidation and ring opening with bromine in CH 2 Cl 2 to give (2-bromoethyl)phosphate ester 4 ; hydrolysis of the PBr bond and quaternization of 4 with aqueous trimethylamine generated 1 .
Overview of three-dimension integration for Point-of-Load converters

High density integrated Point-of-Load (POL) converter is today's industry trend for portable electronic applications. In the past 10 years, Center for Power Electronics Systems (CPES) spent tremendous research efforts in this area and has successfully demonstrated a three-dimension (3D) integration method using magnetic as a substrate to achieve a very high power density at a high current level. CPES not only proposed a series of methods to reduce parasitic inductance of active layer for high frequency operation, but also developed several advanced low profile magnetic structures for 3D integration. This paper gives an overview of CPES's 10-year research efforts on high density 3D integrated POL converters. With CPES's latest technologies, a 20A POL converter with GaN devices was demonstrated with power density as high as 1000W/in3, which is a factor of 10 improvements compared to industry products.
BARYON SPECTROSCOPY ON THE LATTICE

Quantum Chromodynamics (QCD) provides an excellent description of nature; however, the theory suffers from divergences that must be removed to render it finite. Lattice QCD provides an apriori non-perturbative regularization of QCD that makes it amenable to analytic and computational methods. No model assumptions other than QCD itself are needed to formulate the theory. This review surveys the rapidly evolving work in using Lattice QCD for calculations of baryon spectroscopy. Along the way, sources of systematic uncertainties in calculations are described and future directions are outlined.
Global Dynamics of Charged Dust Particles in Planetary Magnetospheres

We study the global stability of charged dust grains orbiting an axisymmetric planet. The corotating magnetic field and induced electric field are described in an inertial frame using the magnetic stream function and a two-dimensional effective potential ${U}^{e}$, parametrized by the conserved angular momentum ${p}_{\ensuremath{\varphi}}$. Stable equilibria form the centers of complex potential wells, so that a particle which loses local stability can still be trapped globally. Applying the results to Saturn, we find that nonequatorial ``halo'' orbits are dominated by positively charged grains.
Optical information capacity of silicon

We have established bounds on information capacity of silicon and have identified new types of noise from which the bounds originate. Our results suggest solutions to extending the limit via coding and coherent signaling.
LARGE-VOLUME STRING COMPACTIFICATIONS, REVISITED

Abstract We reconsider the issue of large-volume compactifications of the heterotic string in light of the recent discoveries about strongly coupled string theories. Our conclusion remains firmly negative with respect to classical compactifications of the ten-dimensional field theory, albeit for a new reason: When the internal sixfold becomes large in heterotic units, the theory acquires an additional threshold at energies much less then the naive Kaluza-Klein scale. It is this additional threshold that imposes the ultimate limit on the compactification scale M KK > 4 × 10 7 GeV for any compactification ; for most compactifications, the actual limit is much higher. (Generically, M KK ≳ α GUT M Plank in either SO (32) or E 8 × E ′ 8 heterotic string.)
Variable-complexity aerodynamic optimization of a high-speed civil transport wing

A new approach for combining conceptual and preliminary design techniques for wing optimization is presented for the high-speed civil transport (HSCT). A wing-shape parametrization procedure is developed which allows the linking of planform and airfoil design variables. Variable-complexity design strategies are used to combine conceptual and preliminary-design approaches, both to preserve interdisciplinary design influences and to reduce computational expense. In the study, conceptual-design-level algebraic equations are used to estimate aircraft weight, supersonic wave drag, friction drag, and drag due to lift. The drag due to lift and wave drag are also evaluated using more detailed, preliminary-design-level techniques. The methodology is applied to the minimization of the gross weight of an HSCT that flies at Mach 3 with a range of 6500 mi.
Exponential formulas for the Jacobians and Jacobian matrices of analytic maps

Abstract Let F =( F 1 , F 2 ,…, F n ) be an n -tuple of formal power series in n variables of the form F ( z )= z + O (| z | 2 ). It is known that there exists a unique formal differential operator A= ∑ i=1 n a i (z)∂/∂z i such that F ( z )=exp( A ) z as formal series. In this article, we show the Jacobian J (F) and the Jacobian matrix J ( F ) of F can also be given by some exponential formulas. Namely, J (F)= exp (A+▽A)·1 , where ▽A(z)= ∑ i=1 n (∂a i /∂z i )(z) , and J ( F )=exp( A + R Ja )· I n × n , where I n × n is the identity matrix and R Ja is the multiplication operator by Ja for the right. As an immediate consequence, we get an elementary proof for the known result that J (F)≡1 if and only if ▽ A =0. Some consequences and applications of the exponential formulas as well as their relations with the well-known Jacobian Conjecture are also discussed.
Characterization and assessment of HTML style guides

This paper describes a study in which HTML style guides were characterized, compared to established HCI style guides, and evaluated against findings from HCI reviews of web paces and applications. Findings showed little consistency among the 21 HTML style guides assessed, with 75% of recommendations appearing in only one style guide. While there was some overlap, only 20% of HTML relevant recommendations from established style guides were found in HTML style guides. HTML style guides emphasized common look and feel, information display, and navigation issues with little mention of many issues prominent in established style guides such as help, message boxes and data entry. This difference is reinforced by other results showing that HTML style guides addressed concerns of web information content pages with much greater success than web-based applications. It is concluded that while the WWW represents a unique HCI environment, development of HTML style guides has been less rigorous, with issues associated with web-based applications largely ignored.
Regularity of Harmonic functions for a class of singular stable-like processes

We consider the system of stochastic differential equations $$ dX_t=A(X_{t-})\, dZ_t, $$ where Zt1 , . . . , Zdt are independent one-dimensional symmetric stable processes of order α, and the matrix-valued function A is bounded, continuous and everywhere non-degenerate. We show that bounded harmonic functions associated with X are Holder continuous, but a Harnack inequality need not hold. The Levy measure associated with the vector-valued process Z is highly singular.
Normal and sinkless Petri nets

We examine both the modeling power of normal and sinkless Petri nets and the computational complexities of various classical decision problems with respect to these two classes. We argue that although neither normal nor sinkless Petri nets are strictly more powerful than persistent Petri nets, they nonetheless are both capable of modeling a more interesting class of problems. On the other hand, we give strong evidence that normal and sinkless Petri nets are easier to analyze than persistent Petri nets. In so doing, we apply techniques originally developed for conflict-free Petri nets — a class defined solely in terms of the structure of the net — to sinkless Petri nets — a class defined in terms of the behavior of the net. As a result, we give the first comprehensive complexity analysis of a class of potentially unbounded Petri nets defined in terms of their behavior.
Are Oil Shocks Inflationary?: Asymmetric and Nonlinear Specifications versus Changes in Regime

This paper identifies a structural break in core U.S. inflation Phillips curves such that oil prices contributed substantially before 1981, but since that time pass-through has been negligible. This characterization is robust to a variety of re-specifications and fits the data better than asymmetric and nonlinear oil price alternatives. Evidence does not support the hypotheses that declining energy intensity or deregulation of energy-producing and -consuming industries played an important role. Monetary policy did not itself become less accommodative of oil shocks, but may have helped create a regime where inflation is less sensitive to price shocks more generally.
Design Concepts for Low-Cost Composite Engine Frames

Design concepts for low-cost, lightweight composite engine frames were applied to the design requirements for the frame of commercial, high-bypass turbine engines. The concepts consist of generic-type components and subcomponents that could be adapted for use in different locations in the engine and to different engine sizes. A variety of materials and manufacturing methods were assessed with a goal of having the lowest number of parts possible at the lowest possible cost. The evaluation of the design concepts resulted in the identification of a hybrid composite frame which would weigh about 70 percent of the state-of-the-art metal frame and cost would be about 60 percent.
Pectus Excavatum : Simple Autogenous Tissue Support to Keep Sternum Elevated

The deformity of pectus excavatum causes no organic disease or functional impairment ordinarily, but it does cause a greater or lesser degree of psychologic problems. It should be repaired for the cosmetic effect and for prevention and/or relief of the psychologic problems. It is best to treat the patient at about two years of age, but can be done at any age. The deformed costal cartilages that have been freed in a subperichondral manner are used to fix the sternum in a normal position once the sternum has been elevated to a normal position. A simple, easy, safe operative procedure certain of correcting the deformity has been described using only autogenous tissue for support of the sternum in the elevated position.
Garbage and Recycling with Endogenous Local Policy

Abstract This paper estimates the impact of garbage fees and curbside recycling programs on garbage and recycling amounts. Without correction for endogenous policy, a price per bag of garbage has a negative effect on garbage and a positive cross-price effect on recycling. Correction for endogenous local policy increases the effect of the user fee on garbage and the effect of curbside recycling collection on recycling. Introducing a fee of $1 per bag is estimated to reduce garbage by 412 pounds per person per year (44%), but to increase recycling by only 30 pounds per person per year.
Approach, avoidance and weight-related testing: An investigation of frontal EEG asymmetry.

Two motivational systems underlie behaviour and affective responses – an inhibition/avoidance system and an activation/approach system. The purpose of the present study was to explore if individual differences in these motivational systems would occur in response to common weight and body composition testing within a sample of young, adult women. Electroencephalogram was used to distinguish approach or avoidance orientations via frontal asymmetry before and after testing sessions. Clear distinctions in motivational response were found, with 65% of the sample responding with an approach motivation, while 35% responded with an avoidance motivation. Even though all participants, on average, experienced a negative affective response, only the avoidance group self-reported a subsequent increase in “comfort food” consumption of desserts and snacks the week following the testing session. As shown with other stressors, clear individual differences exist in motivational responses to common weight and body composit...
Extracting templates from radiology reports using sequence alignment

Health care providers often dictate their reports by filling in slots in templates. These slots can be filled with a variety of different procedures, measurements, or findings. Many radiologists currently create their own personalised templates, costing time and leading to inconsistencies across physicians. We present a sequence alignment method Radiology Content Alignment (RADICAL) that uses dynamic programming to efficiently extract templates that are common across sets of reports, and give examples of the extracted templates and the contents of their slots.
On the endogeneity of telecommunications and economic growth: evidence from Asia

The impact of mobile and fixed telephones on economic growth has been the subject of increasing scrutiny in the literature on economic development. It is even of interest to theoretical macroeconomists, as it provides a useful test of the positive network externalities that should be present if endogenous growth theory is correct. We study the relationship between teledensity and growth in Asia, as the countries there have experienced wildly different levels of telephone penetration per capita , and of rates of growth of GDP per capita . We estimate several econometric models, one which explicitly treats telecom as strictly exogenous, and others which treat it as endogenous. Our conclusions are robust to the econometric specification. We find that the impact of teledensity on growth is positive, and increases with the level of telephone penetration. This provides support for endogenous growth theory.
Constraints on dark matter particles charged under a hidden gauge group from primordial black holes

In order to accommodate increasingly tighter observational constraints on dark matter, several models have been proposed recently in which dark matter particles are charged under some hidden gauge group. Hidden gauge charges are invisible for the standard model particles, hence such scenarios are very difficult to constrain directly. However black holes are sensitive to all gauge charges, whether they belong to the standard model or not. Here, we examine the constraints on the possible values of the dark matter particle mass and hidden gauge charge from the evolution of primordial black holes. We find that the existence of the primordial black holes with reasonable mass is incompatible with dark matter particles whose charge to mass ratio is of the order of one. For dark matter particles whose charge to mass ratio is much less than one, we are able to exclude only heavy dark matter in the mass range of 1011?GeV?1016?GeV. Finally, for dark matter particles whose charge to mass ratio is much greater than one, there are no useful limits coming from primordial black holes.
Combined Experimental/Numerical Development of Propulsor Evaluation Capability

Propulsor design methods utilize Computational Fluid Dynamics (CFD) to develop initial propulsor configurations and predict the full-scale in-water performance of these optimal designs. However, like all numerical models, these CFD models need experimental validation to provide a sufficient level of confidence in the design. The actual data needed to validate CFD models include propulsor inflow velocities and thrust and are impractical to collect for full-scale vehicles. As a result, the in-water propulsor performance can be significantly different than CFD predictions. Another approach in the propulsor design process is to experimentally test a subscale version of the vehicle and appropriately scale results. This scaling is often unreliable due to differences between open water conditions and the flow in the laboratory facility. This paper presents a method to combine CFD modeling with subscale experiments to improve full-scale propulsor performance prediction. Laboratory experiments were conducted on subscale generic torpedo models in the 12″ × 12″ water tunnel located at the Naval Undersea Warfare Center in Newport, Rhode Island. This model included an operational ducted post-swirl propulsor. Laser Doppler Velocimetry was used to measure several velocity profiles along the torpedo hull. The experimental data were used in this project to validate the CFD models constructed using the commercial CFD software, Fluent®. Initially, axisymmetric two-dimensional simulations investigated the bare body, hull only case, and a shrouded body without the propulsor. These models were selected to understand the axisymmetric flow development and investigate methods to best match the propulsor inflow. A variety of turbulence models including the realizable k-epsilon model and the Spallart-Almaras model were investigated and ultimately the numerical and experimental velocity profiles were found to match within 3%. Based on these water tunnel simulations, differences between the flow in the facility and open water could then be characterized. These differences quantified both the effect of Reynolds number as well as local flow acceleration due to tunnel blockage effects. Full 3-D flow simulations were then conducted with an operating propulsor and compared with the corresponding subscale experimental data. Finally, simulations were conducted for full-scale tests and compared with actual in-water data. While the in-water data was limited to propulsor rpm and vehicle velocity, the operating advance ratio could be determined as well as the estimated vehicle thrust. This provided a method to utilize CFD/experiments to bridge the gap between subscale and full-scale tests. The predicted in-water advance ratio of 1.87 was very close to the measured value of 1.75.
Diffuse Galactic Emission from Spinning Dust Grains

Spinning interstellar dust grains produce detectable rotational emission in the 10-100 GHz frequency range. We calculate the emission spectrum and show that this emission can account for the "anomalous" Galactic background component, which correlates with 100 μm thermal emission from dust. Free-free emission cannot account for the anomalous component. Implications for cosmic background studies are discussed.
Cooperative radar and communications signaling: The estimation and information theory odd couple

We investigate cooperative radar and communications signaling. While each system typically considers the other system a source of interference, by considering the radar and communications operations to be a single joint system, the performance of both systems can, under certain conditions, be improved by the existence of the other. As an initial demonstration, we focus on the radar as relay scenario and present an approach denoted multiuser detection radar (MUDR). A novel joint estimation and information theoretic bound formulation is constructed for a receiver that observes communications and radar return in the same frequency allocation. The joint performance bound is presented in terms of the communication rate and the estimation rate of the system.
Time-dependent quantum scattering in 2+1 dimensional gravity

The propagation of a localized wave packet in the conical space-time created by a pointlike massive source in 2+1 dimensional gravity is analyzed. The scattering amplitude is determined and shown to be finite along the classical scattering directions due to interference between the scattered and the transmitted wave functions. The analogy with diffraction theory is emphasized.