cssi/SciSciGPT-SciSciNet huggingface dataset:
Structures of the gauche conformers of some substituted dimethyl ethers. Effect of adjacent atom lone pairs on methyl group asymmetry

Abstract The complete equilibrium structures of CH 3 OCH 3 and of the gauche conformers of CH 3 0CH 2 F, HOCH,F, CH,OCH,Cl and CH,OCH,CN have been determined by ab initio gradient computation at the Hartree-Fock, double zeta-plus-polarization level. The very large asymmetries in CH bond distances previously reported from microwave substitution structures are shown to be non-existent in the equilibrium structures and are presumably artifacts. Small differences, different in direction from those reported from the experiments and nearly an order of magnitude smaller in size, do exist. They reflect three factors: (1) a lengthening of a CH bond which is trans to a lone pair on an adjacent atom, (2) a general shortening of CH bonds originating at a carbon atom bearing a highly electronegative substituent, and (3) a specific interaction in which a CX substituent shortens the nearly parallel CH bond on the other methyl group. The last interaction, not previously reported, is mediated by withdrawal of electron density from the oxygen lone pair which is trans to both groups. Other structural features derived from the microwave studies are supported by the new results. Inclusion of polarization functions in the basis set for oxygen is essential for correct determination of the COC angle and the dihedral angles. The dihedral angles of CH 3 OCH 2 F and HOCH 2 F are not correctly determined by the computation even at this level, although the computed values are improved when d functions are used for oxygen and still more by use of two sets of oxygen d functions. Polarization functions on carbon or on fluorine have no effect on the computed torsional angles. There is no problem in computing the correct dihedral angles with the CI or CN derivatives.
Hydrogen safety problems

Abstract Consideration of use of hydrogen as a common fuel always raises questions on the matter of safety. The hazardous properties of hydrogen should not disqualify it for widespread use. Hydrogen has been used as a transmissible fuel for 150 yr (mixed with carbon monoxide in water gas) and as a portable fuel in cryogenic form within this generation. The accident experience with hydrogen, other than its use in lighter-than-air craft, has not been inordinately worse than the accident experience with more commonly used fuels. Hydrogen has unique properties which require special treatment to lessen risk: broad combustible range, low energy for ignition, rapid diffusion rate and, as a cryogen, the capability to create high pressures if confined without available relief, and the ability to condense all other gases except helium.
Methods for controlling the regioselection in the reaction of 3-amino-5-benzylthio-1,2,4-triazole with acetylacetaldehyde dimethyl acetal

The reaction of 3-amino-5-benzylthio-1,2,4-triazole with acetylacetaldehyde dimethyl acetal affords 2-benzylthio-5-methyl-1,2,4-triazolo [1,5a] pyrimidine or 2-benzylthio-7-methyl-1,2,4-triazolo [1,5a] pyrimidine regioselectively depending on the reaction conditions
Decomposing the Induced Income Changes in Input-Output Models

This paper demonstrates formally that type I and type II income multipliers are proportional across all sectors and that in any input-output model, the difference between the multipliers can range from zero to a maximum of the reciprocal of one less the propensity to consume locally. The conditions which lead to these two extreme values are discussed. For intermediate situations, the difference is decomposed into proportions attributable to final payments and imports. Input-output (I-O) models are used to estimate impacts of economic development, public investment, or other change in public policy on output, employment, and income (e.g., Bills and Barr; Schreiner, Muncrief, and Davis; McKusic). One topic frequently discussed in empirical work and in the classroom is the reduction in the secondary economic impacts caused by leakage from an open economy. Much of the work describes these impacts in qualitative terms or estimates the magnitude of the reductions for a particular empirical application (e.g., Little and Doeksen 1968, 1973). Mustafa provides a general expression for leakage as "the direct plus indirect import requirement for different sectors" (p. 681), but makes no attempt to account for reductions in the economic impacts from other spending streams that go to exogenous final payments sectors rather than being respent locally. This paper analyzes these effects by decomposing analytically the relationship between type I and type II income multipliers. Sandoval and Bradley and Gander show that for a given I-O system, type II multipliers for all sectors are a constant multiple of the corresponding type I multipliers but they do not demonstrate how this multiple is related to the propensity to consume locally and to imports or other final payments. This latter relationship is developed below and is helpful in understanding how sensitive empirical results are to particular I-O coefficients. It is also a rigorous method by which one can demonstrate interactions among production, income, and consumption, and leakages in an I-O model. This paper begins with definitions of terms. A second section outlines briefly Bradley and Gander's derivation, while the third reinterprets this derivation in terms of local propensities to consume, imports, and exogenous final payments.
Simulation of a modified Hubbard model with a chemical potential using a meron-cluster algorithm

Abstract We show how a variant of the Hubbard model can be simulated using a meron-cluster algorithm. This provides a major improvement in our ability to determine the behavior of these types of models. We also present some results that clearly demonstrate the existence of a superconducting state in this model.
EHD Induction Pumping in Annuli

EHD pumps will normally be enclosed in circular pipes, but previous analysis of such pumps was most often undertaken in two-dimensional geometries which cannot represent the curvature and finite size associated with a pipe. One practical version of an EHD induction pump includes an active travelling wave electrode running along the center of a grounded cylindrical pipe. Laminar flow which takes place in the annulus between pipe and electrode is modeled theoretially in terms of an induced charge layer situated at an arbitrary distance from the center electrode. If a hetero-charge layer is present, attraction pumping, in which the fluid follows the electric field wave, results. For a homo-charge layer, repulsion pumping occurs. Calculation of flow rates for various choices of electrical excitation and geometry are given as functions of voltage, frequency, and location of the charge layer. The attraction pump and the heavily loaded repulsion pump both give maximum flow rates at a single non-zero frequency, but the lightly loaded repulsion pump operates best at dc. The implications of these results are discussed in the context of several applications.
Catalytic and stereoselective iodination of prochiral C-H bonds

Oxazolines were employed as cyclic chiral directing groups for stereoselective C–H activation. Oxazoline-directed cleavage of the β-C–H bonds followed by reaction with I2 gave a wide range of iodinated products. A large range of functional groups are tolerated. PdI2 was isolated in the reaction and found to be converted to Pd(OAc)2 upon treatment with a combination of I2 and PhI(OAc)2 in situ to achieve catalytic turnover. Diastereoselective iodination of prochiral C–H bonds were also investigated.
Divergent diastereoselectivity in the addition of nucleophiles to tetrahydrofuran-derived oxonium ions

Abstract Alkyl substituted lactol acetates have been found to undergo highly stereoselective substitution reactions mediated by tin (IV) bromide. The highest selectivity is observed in the case of 4,4-di-isopropyl, 2-methyl substitution in which the selectivity depends on the nucleophile. Allyltrimethylsilane adds with high (95:5) 1,2- syn selectivity while 2-methyl-trimethylsiloxy propene adds with high (>98:2) anti selectivity. These results can be rationalized through conformational analysis of the oxonium ion intermediate.
Hayek’s Nobel after 40 years

This paper serves as the Introduction to the symposium celebrating the 40th anniversary of F.A. Hayek’s Nobel Memorial Prize in Economic Science. The symposium papers were presented at a public event held in October 2014 in Arlington, VA and explore the relevance of Hayek’s research program for the past and future of the economics discipline.
Buckling mode localization in elastic plates due to misplacement in the stiffener location

This paper deals with the buckling of the stiffened plate under uni-axial compression. The direct integration of the governing differential equation is performed and the exact solution to the problem is obtained. As examples, a square plate with single stiffener, and a stiffened three-span, continuous plate are investigated, with special attention given to the influence of stiffener misplacement on the buckling load and mode shape of the plate. It is found that a small misplacement of the stiffeners from the nominal configuration may change the buckling mode from a global one to a highly localized one.
Finite generators for countable group actions in the Borel and Baire category settings

Abstract For a continuous action of a countable discrete group G on a Polish space X, a countable Borel partition P of X is called a generator if G P : = { g P : g ∈ G , P ∈ P } generates the Borel σ-algebra of X. For G = Z , the Kolmogorov–Sinai theorem gives a measure-theoretic obstruction to the existence of finite generators: they do not exist in the presence of an invariant probability measure with infinite entropy. It was asked by Benjamin Weiss in the late 1980s whether the nonexistence of any invariant probability measure guarantees the existence of a finite generator. We show that the answer is positive (in fact, there is a 32-generator) for an arbitrary countable group G and σ-compact X (in particular, for locally compact X). We also show that for aperiodic actions there is always a 4-generator on a comeager set, thus giving a positive answer to a question of Alexander Kechris asked the mid-1990s. Furthermore, assuming a positive answer to Weiss's question for arbitrary Polish spaces and G = Z , we prove the following dichotomy: every aperiodic Borel action of Z on a Polish space X admits either an invariant probability measure of infinite entropy or a finite generator. As an auxiliary lemma, we prove the following statement, which may be of independent interest: every aperiodic Borel action of a countable group G on a Polish space X admits a G-equivariant Borel map to the aperiodic part of the shift action G ↷ 2 G . We also obtain a number of other related results, among which is a criterion for the nonexistence of non-meager weakly wandering sets for continuous actions of Z . A consequence of this is a negative answer to a question asked by Eigen–Hajian–Nadkarni, which was also independently answered by Benjamin Miller.
Balanced line bundles and equivariant compactifications of homogeneous spaces

Manin's conjecture predicts an asymptotic formula for the number of rational points of bounded height on a smooth projective variety in terms of its global geometric invariants. The strongest form of the conjecture implies certain inequalities among geometric invariants of the variety and of its subvarieties. We provide a general geometric framework explaining these phenomena, via the notion of balanced line bundles, and prove the required inequalities for a large class of equivariant compactifications of homogeneous spaces.
Calcite dissolution kinetics in saline waters

Abstract The effect of ionic strength (I), pCO2, and temperature on the dissolution rate of calcite was investigated in magnesium-free, phosphate-free, low calcium (mCa2+ ≈ 0.01 m) simple KCl and NaCl solutions over the undersaturation range of 0.4 ≤ Ωcalcite ≤ 0.8. First-order kinetics were found sufficient to describe the rate data where the rate constant (k) is dependent on the solution composition. Rates decreased with increasing I and were faster in KCl than NaCl solutions at the same I indicating that Na+ interacts more strongly with the calcite surface than K+ or that water is less available in NaCl solutions. Rates increased with increasing pCO2 and temperature, and their influences diminished at high I. Arrhenius plots yielded a relatively high activation energy (Ea ≈ 20 ± 2 kJ mol− 1) which indicated that dissolution was dominated by surface-controlled processes. The multiple regression model (MR) of Gledhill and Morse (2006a) was found to adequately describe the results at high I in NaCl solutions, but caution must be used when extrapolating to low I or pCO2 values. These results are consistent with the hypothesis that the mole fraction of “free” solvent (X“free”H2O) plays a significant role in the dissolution kinetics of calcite with a minimum value of ∼ 45–55% required for dissolution to proceed in undersaturated solutions at 25–55 °C and pCO2 = 0.1–1 atm. This hypothesis has been incorporated into a modified version of the MR model of Gledhill and Morse (2006a) where X“free”H2O has replaced I and the Ca2+ and Mg2+ terms have been dropped: k pred = β 0 + β 1 T + β 2 p C O 2 + β 3 X ”free”H 2 O .
Peace Processes and IDP Solutions

The forcible uprooting of people is an inevitable consequence of armed conflict. The processes by which peace agreements are negotiated and implemented will determine whether and under what conditions internally displaced persons (IDPs) will return home or whether other solutions will be necessary or possible. If countries newly emerging from conflict are able to find durable solutions for IDPs and other war-affected populations, it is a significant bellwether for the success of the overall peace process. IDP concerns arise most visibly in the humanitarian practices of government and insurgent parties prior to the conclusion of an overall peace agreement. Subsequently, the language in peace agreements about procedures for refugee returns also encompasses IDP questions. Over the long term, the integration of IDPs depends on the local, regional, and national implementation of agreed principles. International monitoring of local implementation is weak at best.
Joint debridement for osteoarthritis of the elbow through a bilateral approach

There are various surgical procedures for osteoarthritis of the elbow joint, such as, resection arthroplasty, total elbow replacement and joint debridement [2]. The indication for each procedure depends on the activities of the patient as well as the stage of the disease. Resection arthroplasty is indicated for severe osteoarthritis. It provides good mobility and relief of pain but joint instability resulting from this procedure is a defnite disadvantage, especially for the manual laborer. Total elbow replacement is also indicated for severe osteoarthritis or rheumatoid arthritis. It provides relatively good stability of the elbow joint, but there is a possibility of loosening of the implants [1, 3]. Total elbow replacement is therefore also contraindicated for a manual laborer. The principle of the joint debridement is to remove the osteophytes, which restrict elbow motion, and to release the contracted capsule in order to improve joint motion and to decrease pain. This procedure is indicated for moderate to severe osteoarthritis. The best indication for this procedure is osteoarthritis of the elbow in active patients or manual laborers. There have been some reports about the joint debridement procedure in which different approaches were used [4, 5]. Ogino developed a joint debridement procedure through a bilateral approach. A salient feature of this procedure is the preservation of the lateral and medical collateral ligaments.
Possibilities for improved supersonic inlet performance

The results from detailed large-scale inlet tests were examined to assess the penalties, in terms of vehicle cruise range, for boundary-layer bleed, less than ideal engine-face pressure recovery, inlet weight, and external cowl drag. The assessment suggested specific improvements in the design of the inlet system that may increase the range of a typical supersonic transport approximately 6.9%. While no single design improvement can account for a large increase in range, careful attention to each design detail can yield a substantial total improvement. Because of noise considerations, future engines for advanced supersonic transports may be approximately 50% larger than used for the present study, making the effects of improved inlet performance even more important.
Are surgeons capable of introspection

The traditional action-oriented surgical personality, although essential in the service of solving emergent operative dilemmas, may serve as a barrier to introspection. Certainly, challenges of the twenty-first century practice environment, including time constraints, also distract from self-reflection. Without engaging in moments of introspection, surgeons risk not only abandoning dying patients in their time of need, but leave the surgeons themselves at risk for burnout and its consequences. The increase in the number of women surgeons, as well as the less heroic image of surgeons performing laparoscopic operations, may reorient traditional extroverted behavior toward a persona of professional grace.
KEPLER ECLIPSING BINARY STARS. I. CATALOG AND PRINCIPAL CHARACTERIZATION OF 1879 ECLIPSING BINARIES IN THE FIRST DATA RELEASE

The Kepler space mission is devoted to finding Earth-size planets orbiting other stars in their habitable zones. Its large, 105 deg2 field of view features over 156,000 stars that are observed continuously to detect and characterize planet transits. Yet, this high-precision instrument holds great promise for other types of objects as well. Here we present a comprehensive catalog of eclipsing binary stars observed by Kepler in the first 44 days of operation, the data being publicly available through MAST as of 2010 June 15. The catalog contains 1879 unique objects. For each object, we provide its Kepler ID (KID), ephemeris (BJD0, P 0), morphology type, physical parameters (T eff, log g, E(B – V)), the estimate of third light contamination (crowding), and principal parameters (T 2/T 1, q, fillout factor, and sin i for overcontacts, and T 2/T 1, (R 1 + R 2)/a, esin ω, ecos ω, and sin i for detached binaries). We present statistics based on the determined periods and measure the average occurrence rate of eclipsing binaries to be ~1.2% across the Kepler field. We further discuss the distribution of binaries as a function of galactic latitude and thoroughly explain the application of artificial intelligence to obtain principal parameters in a matter of seconds for the whole sample. The catalog was envisioned to serve as a bridge between the now public Kepler data and the scientific community interested in eclipsing binary stars.
Convergence of Fixed-Point Continuation Algorithms for Matrix Rank Minimization

The matrix rank minimization problem has applications in many fields, such as system identification, optimal control, low-dimensional embedding, etc. As this problem is NP-hard in general, its convex relaxation, the nuclear norm minimization problem, is often solved instead. Recently, Ma, Goldfarb and Chen proposed a fixed-point continuation algorithm for solving the nuclear norm minimization problem (Math. Program., doi: 10.1007/s10107-009-0306-5, 2009). By incorporating an approximate singular value decomposition technique in this algorithm, the solution to the matrix rank minimization problem is usually obtained. In this paper, we study the convergence/recoverability properties of the fixed-point continuation algorithm and its variants for matrix rank minimization. Heuristics for determining the rank of the matrix when its true rank is not known are also proposed. Some of these algorithms are closely related to greedy algorithms in compressed sensing. Numerical results for these algorithms for solving affinely constrained matrix rank minimization problems are reported.
Tweets, hashtags and virality: Marketing the Affordable Care Act in social media

To help offset the costs brought on by insuring previously uninsurable consumers, the Affordable Care Act (ACA) needed adequate enrolments of millennials. To engage with this tech-savvy cohort, the Obama administration had to think outside traditional media and build a robust presence in social media. The present article provides a historical account of how the ACA was promoted to millennials using social media. In turn, it provides an example of how social media platforms, including Twitter, Facebook and YouTube, and strategies, including hashtag and virality campaigns, can be used to promote public policy adoption.
Synthesis and structure of Li3Ba2TaN4

A new quaternary nitride, Li3Ba2TaN4, has been synthesized from Li, Ba and Ta metals under flowing N2 at high temperature. The structure, as determined by single crystal X-ray diffraction techniques, is monoclinic, space group C2c, Z=4, with lattice parameters a=11.294(2) A, b=5.678(1) A, c=11.350(2) A, and β=121.407(7)°. Refinement based upon F2 yielded R2=0.052 and wR2=0.074 (for comparison, a refinement based upon F yielded R1=0.032). The Ta and one of the two independent Li ions are tetrahedrally coordinated by N anions; the Li tetrahedra are distorted. By sharing edges, the Ta and Li tetrahedra form chains which are linked together by the remaining Li ions to form the three-dimensional structure.
Conformational stability, barriers to internal rotation, normal coordinate analyses, and vibrational assignments of bromoacetyl halides

Abstract The Raman (3200-10 cm −1 ) and IR (3200-30 cm −1 ) spectra of bromoacetyl fluoride, bromoacetyl chloride and bromoacetyl bromide in the gaseous and annealed solid phases have been recorded. Additionally, the Raman spectra and the qualitative depolarization measurements for each molecule in the liquid phase have been obtained. All of these data indicate that these bromoacetyl halides exist in mixtures of two conformers, with the trans rotamer (halogen atoms oriented trans to one another) being the thermodynamically preferred, and the gauche conformation being the high energy form. From the studies of Raman spectra at different temperatures, the enthalpy differences have been determined for the gaseous and liquid phases, respectively, to be 185 ± 23 cm −1 (0.53 ± 0.06 kcal mol −1 ) and 249 ± 27 cm −1 (0.71 ± 0.08 kcal mol −1 ) for bromoacetyl fluoride, 391 ± 130 cm −1 (1.12 ± 0.37 kcal mol −1 ) and 317 ± 27 cm −1 (0.91 ± 0.08 kcal mol −1 ) for bromoacetyl chloride, and 341 ± 48 cm −1 (0.98 ± 0.14 kcal mol −1 ) and 286 ± 26 cm −1 (0.82 ± 0.07 kcal mol −1 ) for bromoacetyl bromide. Potential functions have been calculated for the fluoride and chloride from the observed asymmetric torsional frequencies and values of 580 ± 11 cm −1 (1.66 ± 0.03 kcal mol −1 ), 359 ± 8 cm −1 (1.03 ± 0.02 kcal mol −1 ), and 387 ± 16 cm −1 (1.11 ± 0.04 kcal mol −1 ) for the trans to gauche, gauche to gauche to gauche and gauche to trans barrier, respectively, were determined for bromoacetyl fluoride. The corresponding quantities were 967 ± 30 cm −1 (2.76 ± 0.08 kcal mol −1 ), 696 ± 67 cm −1 (1.99 ± 0.19 kcal mol −1 ), and 663 ± 30 cm −1 (1.61 ± 0.08 kcal mol −1 ) for bromoacetyl chloride. These potential functions are consistent with the dihedral angle of the gauche conformation being 120° and 117° for the fluoride and chloride, respectively. Complete vibrational assignments have been carried out based on the observed IR band contours, the depolarization ratios, and group frequencies. The results are compared to those for other haloacetyl halides.
Privatization Incidence, Ownership Forms, and Firm Performance: Evidence from Slovenia☆☆☆

Abstract There is active debate in transition economies about the extent to which employee and foreign ownership ought to be encouraged or discouraged in privatization, but empirical evidence is scarce. This paper employs a unique data set on Slovene firms during an early period of “spontaneous privatization.” Characteristics of the incidence of employee and foreign ownership and associated firm performance are examined. The paper controls for simultaneity between privatization and firm performance using a two-stage Tobit least-squares procedure. An elasticity of output with respect to ownership type is estimated. A percentage point increase in foreign ownership is associated with about a 3.9% increase in value-added and for employee ownership with about a 1.4% increase; there is evidence of diminishing marginal productivity gains for both forms of ownership. J. Comp. Econom., October 1997, 25 (2), pp. 158–179. George Washington University, Washington, DC 20052; Academy of Entrepreneurship, Slovenia, and World Bank, Washington, DC 20433.
Intermetallic Compounds with 1D Infinite Tunnels. Syntheses and Structures of AAu4In2 (A = K, Rb)

Four intermetallic compounds KxRb1-xAu4In2 (x = 0−1) synthesized by high-temperature solid-state reactions display 1D infinite tunnel constructions with Au−In frameworks. These compounds show small but different cation displacements in the tunnels and are also air and moisture inert at room temperature, even in concentrated HCl(aq).
The shape parameter in the Gaussian function

This is the fifth of our series of works about the shape parameter. We now explore the parameter @b contained in the famous Gaussian function e^-^@b^|^x^|^^^2,[email protected]?R^n. In the theory of radial basis functions (RBFs), the Gaussian is frequently used in virtue of its good error bound and numerical tractability. However, the optimal choice of @b has been unknown. People conversant with RBFs know that @b is very influential, but do not have a reliable criterion of its choice. The purpose of this paper is to uncover its mystery. In particular, we have greatly improved the result of Madych (1992) in [15], and we present a concrete function of @b which shows the influence of @b in the error estimate of Gaussian interpolation and with which the optimal @b can always be found.
A note on (no) firewalls: the entropy argument

United States. Dept. of Energy. Office of High Energy and Nuclear Physics (Contracts DE-FG02-05ER41360 and DE-AC02-05CH11231)
Renormalized gauge propagator in hot gauge theories

Abstract The spectral representation of the renormalized gauge propagator is calculated perturbatively in the limit of high temperature. The interaction of an abelian field with an external current is also determined.
Water-trapped Worlds

Although tidally locked habitable planets orbiting nearby M-dwarf stars are among the best astronomical targets to search for extrasolar life, they may also be deficient in volatiles and water. Climate models for this class of planets show atmospheric transport of water from the dayside to the nightside, where it is precipitated as snow and trapped as ice. Since ice only slowly flows back to the dayside upon accumulation, the resulting hydrological cycle can trap a large amount of water in the form of nightside ice. Using ice sheet dynamical and thermodynamical constraints, I illustrate how planets with less than about a quarter the Earth's oceans could trap most of their surface water on the nightside. This would leave their dayside, where habitable conditions are met, potentially dry. The amount and distribution of residual liquid water on the dayside depend on a variety of geophysical factors, including the efficiency of rock weathering at regulating atmospheric CO2 as dayside ocean basins dry up. Water-trapped worlds with dry daysides may offer similar advantages as land planets for habitability, by contrast with worlds where more abundant water freely flows around the globe.
A TRIPARTITE CLUSTERING ANALYSIS ON MICRORNA, GENE AND DISEASE MODEL

Alteration of gene expression in response to regulatory molecules or mutations could lead to different diseases. MicroRNAs (miRNAs) have been discovered to be involved in regulation of gene expression and a wide variety of diseases. In a tripartite biological network of human miRNAs, their predicted target genes and the diseases caused by altered expressions of these genes, valuable knowledge about the pathogenicity of miRNAs, involved genes and related disease classes can be revealed by co-clustering miRNAs, target genes and diseases simultaneously. Tripartite co-clustering can lead to more informative results than traditional co-clustering with only two kinds of members and pass the hidden relational information along the relation chain by considering multi-type members. Here we report a spectral co-clustering algorithm for k-partite graph to find clusters with heterogeneous members. We use the method to explore the potential relationships among miRNAs, genes and diseases. The clusters obtained from the algorithm have significantly higher density than randomly selected clusters, which means members in the same cluster are more likely to have common connections. Results also show that miRNAs in the same family based on the hairpin sequences tend to belong to the same cluster. We also validate the clustering results by checking the correlation of enriched gene functions and disease classes in the same cluster. Finally, widely studied miR-17-92 and its paralogs are analyzed as a case study to reveal that genes and diseases co-clustered with the miRNAs are in accordance with current research findings.
How many random edges make a dense graph Hamiltonian

This paper investigates the number of random edges required to add to an arbitrary dense graph in order to make the resulting graph Hamiltonian with high probability. Adding Θ(n) random edges is both necessary and sufficient to ensure this for all such dense graphs. If, however, the original graph contains no large independent set, then many fewer random edges are required. We prove a similar result for directed graphs.
MDSL: a Microcomputer Design and Simulation Language

MDSL, which stands for Microcomputer Design and Simulation Language, is one of an ever growing number of computer hardware design (or description) languages or CHDL's. The introduction of any new language, particularly a new CHDL, is accompanied by a number of WHYs. Why should anyone bother to develop a CHDL? Why did we bother to develop a new one? Why did MDSL take the form it did?
E and S0 galaxies in the central part of the Coma cluster: ages, metal abundances and dark matter

Mean ages and metal abundances are estimated for the stellar populations in a sample of 115 E and S0 galaxies in the central 64 arcmin × 70 arcmin of the Coma cluster. The estimates are based on the absorption line indices Mg2, and HβG, and the mass-to-light ratios (M/L). Single stellar population models from Vazdekis et al. were used to transform from the measured line indices and M/L ratios to mean ages and mean metal abundances ([Mg/H] and [Fe/H]). The non-solar abundance ratios [Mg/Fe] were taken into account by assuming that for a given age and iron abundance, a [Mg/Fe] different from solar will affect the Mg2 index but not the M/L ratio or the and HβG indices. The derived ages and abundances are the luminosity-weighted mean values for the stellar populations in the galaxies. By comparing the mean ages derived from the Mg2–HβG diagram with those derived from the Mg2–M/L diagram, we estimate the variations of the fraction of dark matter. Alternatively, the difference between the two estimates of the mean age may be caused by variations in the initial mass function or any non-homology of the galaxies. The distributions of the derived mean ages and abundances show that there are real variations in both the mean ages and the abundances. We find an intrinsic rms scatter of [Mg/H], [Fe/H] and [Mg/Fe] of 0.2 dex, and an intrinsic rms scatter of the derived ages of 0.17 dex. The magnesium abundances [Mg/H] and the abundance ratios [Mg/Fe] are both strongly correlated with the central velocity dispersions of the galaxies, while the iron abundances [Fe/H] are uncorrelated with the velocity dispersions. Further, [Mg/H] and [Fe/H] are strongly anticorrelated with the mean ages of the galaxies. This is not the case for [Mg/Fe]. We have tested whether the slopes of the scaling relations between the global parameters for the galaxies (the Mg2–σ relation, the –σ relation, the HβG–σ relation and the Fundamental Plane) are consistent with the relation between the ages, the abundances and the velocity dispersions. We find that all the slopes, except the slope of the Fundamental Plane, can be explained in a consistent way as resulting from a combination between variations of the mean ages and the mean abundances as functions of the velocity dispersions. The slope of the Fundamental Plane is ‘steeper’ than predicted from the variations in the ages and abundances. Because of the correlation between the mean ages and the mean abundances, substantial variations in the ages and the abundances are possible while maintaining a low scatter of all the scaling relations. When this correlation is taken into account, the observed scatter of the scaling relations is consistent with the rms scatter in the derived ages and abundances at a given velocity dispersion.
Evaluation of a multiple-beam defect inspection platform using an integrated reference mask

Many inspection tools generate massive false defects in the presence of radical OPC decorations or sub spec line widths causing system aborts and retries. We have defined the inspectivity (or runability) of a tool as the ability to complete inspections in the presence of challenging geometry, while still maintaining high defect sensitivity. A new UV wavelength multiple beam reticle inspection tool has been designed to dramatically reduce inspection time with improved inspectivity. Comprehensive inspection system capability evaluation should include both sensitivity and runability (i.e., ability to inspect various pattern types and sizes). An integrated reference mask was designed previously in order to quantify runability. The mask contains several typical industry feature types at multiple technology nodes. Detailed sensitivity and runability information for two inspection systems has been analyzed and is presented here. The test results provide direction for future improvements by identifying the strengths and weaknesses of inspection systems and their algorithms. In this study we have compared the sensitivity and runability of the KLA-Tencor 365UV-HR to that of the new TeraSTAR™ multiple beam inspection tool.
Consistent scenarios for cosmic-ray excesses from Sommerfeld-enhanced dark matter annihilation

Anomalies in direct and indirect detection have motivated models of dark matter consisting of a multiplet of nearly-degenerate states, coupled by a new GeV-scale interaction. We perform a careful analysis of the thermal freezeout of dark matter annihilation in such a scenario. We compute the range of ``boost factors'' arising from Sommerfeld enhancement in the local halo for models which produce the correct relic density, and show the effect of including constraints on the saturated enhancement from the cosmic microwave background (CMB). We find that boost factors from Sommerfeld enhancement of up to ~ 800 are possible in the local halo. When the CMB bounds on the saturated enhancement are applied, the maximal boost factor is reduced to ~ 400 for 1?2 TeV dark matter and sub-GeV force carriers, but remains large enough to explain the observed Fermi and PAMELA electronic signals. We describe regions in the DM mass-boost factor plane where the cosmic ray data is well fit for a range of final states, and show that Sommerfeld enhancement alone is enough to provide the large annihilation cross sections required to fit the data, although for light mediator masses (m200 MeV) there is tension with the CMB constraints in the absence of astrophysical boost factors from substructure. Additionally, we consider the circumstances under which WIMPonium formation is relevant and find for heavy WIMPs (2TeV) and soft-spectrum annihilation channels it can be an important consideration; we find regions with m?2.8TeV that are consistent with the CMB bounds with (600?700) present-day boost factors.
The evolution of debt and equity markets in economic development

As noted by Gurley and Shaw, there is a typical pattern of economic development in which the evolution of the financial system is an essential aspect of the growth process. We focus on one component of this evolution: the increasing importance of equity markets as an economy grows. We develop a growth model where capital accumulation is financed externally through a combination of debt and equity. We illustrate why equity market activity might grow – often very rapidly – as an economy develops. We also illustrate why access to equity markets may not be needed in the early stages of economic development.
Can a light technipion be discovered at the Tevatron if it decays to two gluons

Abstract In multiscale and topcolor-assisted models of walking technicolor, light, spin-one technihadrons can exist with masses of a few hundred GeV; they are expected to decay as ρT→WπT. For M ρ T ≃200 GeV and M π T ≃100 GeV , the process p p →ρ T →Wπ T has a cross section of about a picobarn at the Tevatron. We demonstrate the detectability of this process with simulations appropriate to Run II conditions, for the challenging case where the technipion decays dominantly into two gluons.
The shadow price of information in continuous time decision problems

We formulate a continuous time stochastic control problem and establish the existence of the shadow price of information. This shadow price is the Lagrange multiplier for the constraint that the control be adapted or predictable; it is a stochastic process of integrable variation, and, in one formulation, it is a martingale. The results are applied to problems of security investment, selling an asset, and economic growth. In the last application, it is shown that the existence of the shadow price of information implies the validity of the stochastic maximum principle
Recent advances in the Langlands Program

These are the notes for the lecture given by the author at the “Mathematical Current Events” Special Session of the AMS meeting in Baltimore on January 17, 2003. Topics reviewed include the Langlands correspondence for GL(n) in the function field case and its proof by V. Drinfeld and L. Lafforgue; the geometric Langlands correspondence for GL(n) and its proof by D. Gaitsgory, K. Vilonen and the author; and the work of A. Beilinson and V. Drinfeld on the quantization of the Hitchin system and the Langlands correspondence for an arbitrary semisimple algebraic group.
Connectivity of Millimeter Wave Networks With Multi-Hop Relaying

This letter presents a novel stochastic geometry approach to the connectivity of milimeter wave (mmWave) networks with multi-hop relaying. The random positions and shapes of obstacles in the radio environment are modeled as a Boolean model, whose germs are distributed according to a Poisson point process and grains are random rectangles. The derived analytical results shed light on how the connectivity of mmWave networks depends on key system parameters such as the density and size of obstacles as well as relaying route window —the range of distances in which routing relays are selected. We find that multi-hop relaying can greatly improve the connectivity versus single hop mmWave transmission. We show that to obtain near-optimal connectivity the relaying route window should be about the size of the obstacles.
Superconductivity solves the monopole problem for Alice strings

Abstract Alice strings are cosmic strings that turn matter into antimatter. Although they arise naturally in many GUTs, it has long been believed that because of the monopole problem they can have no cosmological effects. We show this conclusion to be false; by using the Langacker-Pi mechanism, monopoles can in fact be annihilated while Alice strings are left intact. This opens up the possibility that they can after all contribute to cosmology, and we mention some particularly important examples.
Performance analysis of k-fold multicast networks

Multicast involves transmitting information from a single source to multiple destinations, and is an important operation in high-performance networks. A k-fold multicast network was recently proposed as a cost-effective solution to providing better quality-of-service functions in supporting real-world multicast applications. To give a quantitative basis for network designers to determine the suitable value of system parameter k under different traffic loads, in this paper, we propose an analytical model for the performance of k-fold multicast networks under Poisson traffic. We first give the stationary distribution of network states, and then derive the throughput and blocking probability of the network. We also conduct extensive simulations to validate the analytical model, and the results show that the analytical model is very accurate under the assumptions made. The analytical and simulation results reveal that by increasing the fold of the network, network throughput increases very fast when the fanouts of multicast connections are relatively small, compared with the network size.
Equation of motion for the process matrix: Hamiltonian identification and dynamical control of open quantum systems

We develop a general approach for monitoring and controlling evolution of open quantum systems. In contrast to the master equations describing time evolution of density operators, here, we formulate a dynamical equation for the evolution of the process matrix acting on a system. This equation is applicable to non-Markovian and/or strong-coupling regimes. We propose two distinct applications for this dynamical equation. We first demonstrate identification of quantum Hamiltonians generating dynamics of closed or open systems via performing process tomography. In particular, we argue how one can efficiently estimate certain classes of sparse Hamiltonians by performing partial tomography schemes. In addition, we introduce an optimal control theoretic setting for manipulating quantum dynamics of Hamiltonian systems, specifically for the task of decoherence suppression.
Functional enrichment analyses and construction of functional similarity networks with high confidence function prediction by PFP

A new paradigm of biological investigation takes advantage of technologies that produce large high throughput datasets, including genome sequences, interactions of proteins, and gene expression. The ability of biologists to analyze and interpret such data relies on functional annotation of the included proteins, but even in highly characterized organisms many proteins can lack the functional evidence necessary to infer their biological relevance. Here we have applied high confidence function predictions from our automated prediction system, PFP, to three genome sequences, Escherichia coli, Saccharomyces cerevisiae, and Plasmodium falciparum (malaria). The number of annotated genes is increased by PFP to over 90% for all of the genomes. Using the large coverage of the function annotation, we introduced the functional similarity networks which represent the functional space of the proteomes. Four different functional similarity networks are constructed for each proteome, one each by considering similarity in a single Gene Ontology (GO) category, i.e. Biological Process, Cellular Component, and Molecular Function, and another one by considering overall similarity with the funSim score. The functional similarity networks are shown to have higher modularity than the protein-protein interaction network. Moreover, the funSim score network is distinct from the single GO-score networks by showing a higher clustering degree exponent value and thus has a higher tendency to be hierarchical. In addition, examining function assignments to the protein-protein interaction network and local regions of genomes has identified numerous cases where subnetworks or local regions have functionally coherent proteins. These results will help interpreting interactions of proteins and gene orders in a genome. Several examples of both analyses are highlighted. The analyses demonstrate that applying high confidence predictions from PFP can have a significant impact on a researchers' ability to interpret the immense biological data that are being generated today. The newly introduced functional similarity networks of the three organisms show different network properties as compared with the protein-protein interaction networks.
Almost tight upper bounds for lower envelopes in higher dimensions

We consider the problem of bounding the combinatorial complexity of the lower envelope ofn surfaces or surface patches ind-space (d?3), all algebraic of constant degree, and bounded by algebraic surfaces of constant degree. We show that the complexity of the lower envelope ofn such surface patches isO(nd?1+?), for any ?>0; the constant of proportionality depends on ?, ond, ons, the maximum number of intersections among anyd-tuple of the given surfaces, and on the shape and degree of the surface patches and of their boundaries. This is the first nontrivial general upper bound for this problem, and it almost establishes a long-standing conjecture that the complexity of the envelope isO(nd-2?q(n)) for some constantq depending on the shape and degree of the surfaces (where ?q(n) is the maximum length of (n, q) Davenport-Schinzel sequences). We also present a randomized algorithm for computing the envelope in three dimensions, with expected running timeO(n2+?), and give several applications of the new bounds.
Oil-Based Drilling Mud as a Gas-Hydrates Inhibitor

Gas-hydrates formation must be considered when petroleum reservoirs are developed in arctic regions and deepwater environments. This paper demonstrates that gas hydrates can form in oil-based muds, but that two major components - oil and dissolved solids in the aqueous phase - significantly inhibit this formation. This work identifies two major components in oil-based drilling mud that affect gas-hydrates formation. The temperature and extent of gas-hydrates formation both can be inhibited significantly, but not necessarily prevented, in oil-based drilling muds. A system that contained 20-vol % water and has an oil-continuous phase inhibited gas-hydrates formation 5 to 10{degrees} F. Dissolved solids in a 19.22-wt% calcium chloride (CaCl{sub 2}) brine inhibited gas-hydrates formation 20 to 25{degrees} F and significantly reduced the extent of formation. Gas-hydrates formation in an oil-based drilling mud, prepared with 20-vol%, 19.22-wt% brine, was inhibited more than 30{degrees} F over the pressure range studied, 500 to 4,500 psig. In most cases, oil-based mud can be prepared with sufficient concentrations of dissolved solids to prevent gas-hydrates formation under downhole conditions. Mud samples should be tested to determine the temperature of gas-hydrates formation before field use.
FLUORINATED TRIS(PYRAZOLYL)BORATES AND SILVER(I) COMPLEXES OF GROUP 14 LIGANDS

This review presents an overview of fluorinated tris(pyrazolyl)borate ligands and their role in the development of silver adducts containing group 14 ligands. Tris(pyrazolyl)borates bearing fluorocarbon substituents are sterically somewhat similar but electronically very different from their hydrocarbon counterparts. They have weakly donating nitrogen sites. Fluorinated hydridotris(pyrazolyl)borates also have less reducing B-H groups. These mono-anionic, nitrogen-based donors are ideal supporting ligands to stabilize silver complexes bearing labile donors. For example, fluorinated tris(pyrazolyl)borates have enabled the isolation of thermally stable Ag(I)-CO, Ag(I)-ethylene, and Ag(I)-acetylene adducts. Compounds with unsupported Ag(I)-Ge(II) and Ag(I)-Sn(II) bonds have also been synthesized. Most of these contain easily removable halide groups and silver atoms in the same molecule, but do not show the silver-halide metathesis. Fluorinated tris(pyrazolyl)borate ligands without the problematic B-H moiety h...