cssi/SciSciGPT-SciSciNet huggingface dataset:
Scramjet integration on hypersonic research airplane concepts

Several rocket-boosted research airplane concepts were evaluated with a research scramjet engine to determine their potential to provide research on critical aspects of airframe-integrated hypersonic systems. Extensive calculations to determine the force and moment contributions of the scramjet inlet, combustor, nozzle, and airframe were conducted to evaluate the overall performance of the combined engine/airframe system at hypersonic speeds. Results of both wind-tunnel tests and analysis indicate that it is possible to develop a research airplane configuration that will cruise at hypersonic speed on scramjet power alone, and will also have acceptable low-speed aerodynamic characteristics for landing.
Synthesis and characterization of a dimeric tris(arsino)gallane containing a nonplanar (Ga−As)2 ring: crystal structure of {[(Me3SiCH2)2As]3Ga}2

Abstract The dimer {[(Me 3 SiCH 2 ) 2 As] 3 Ga} 2 , only the second tris(arsino)gallane to be completely characterized, has been prepared by the reaction of (Me 3 SiCH 2 ) 2 AsLi with GaCl 3 ; X-ray crystallographic analysis shows it to be the first example of a compound containing a distinctly nonplanar four-membered ring of alternating four-coordinate Ga and As atoms.
Time and Pressure Measurements in the Corona

Pressure Effects Due to the Corona Discharge in Dry Air.---The discharge took place from a fine wire inside a concentric tube. By means of a sensitive differential gage it was found that the pressure at the tube was 0.004 cm. of water higher than at the wire, for both $A.C$. and $D.C$. discharges. Studies made with a recording mica diaphragm gage showed that on starting the D.C. discharge the pressure rose gradually, reaching in about 1\textonehalf{} seconds a limiting value proportional to the current. The curves for A.C. discharges were the same except that superposed on the D.C. curves were periodic pressure changes with twice the frequency of the alternating voltage and with an amplitude of 0.3 cm. of water. When the wire was heated without the discharge, with either A.C. or D.C. current, the pressure curve took about 20 seconds to reach its limiting value and showed no periodic variations. If when the steady state was reached the corona discharge was started, the pressure either decreased to a lower limiting value, or increased to a maximum and then decreased to a limiting value lower than before or higher than before, depending on the voltage of the discharge. Evidently several effects are superposed in this case. The experiments show the existence of characteristic pressures in the corona in addition to the pressure due to the heating of the gas by the current through the wire.
Curvature estimates for the Ricci flow II

In this paper we present several curvature estimates and convergence results for solutions of the Ricci flow, including the volume normalized Ricci flow and the normalized Kahler-Ricci flow. The curvature estimates depend on smallness of certain local space-time integrals of the norm of the Riemann curvature tensor, while the convergence results require finiteness of space-time integrals of this norm. These results also serve as characterization of blow-up singularities.
An experimental data base for the computational fluid dynamics of combustors

A model axisymmetric gas-fired can combustor is used to establish the sensitivity of the aerodynamic and thermal structure to inlet boundary conditions, and thereby establish a demanding and comprehensive data base for the computational fluid dynamics of combustors. The parameters varied include fuel injection angle and inlet configuration. Detailed characterizations of the aerodynamic and thermal flowfields are accomplished using two-color laser anemometry and a Type R thermocouple, respectively. Specific results show that the reactor operation is especially sensitive to modest changes in both the inlet geometry and fuel injection angle.
Calix[2]bipyrrole[2]furan and calix[2]bipyrrole[2]thiophene: new pyrrolic receptors exhibiting a preference for carboxylate anions.

Heterocycles other than pyrrole, specifically bipyrrole, furan, and thiophene, have been used to construct two new, calixpyrrole-like anion receptors; binding studies, carried out by ITC in CH3CN, reveal a selectivity for “Y-shaped” anions, such as benzoate, over spherical ones, such as chloride.
Implications of a Higgs discovery at LEP

Abstract If the Higgs boson has a mass below 130 GeV, then the standard model vacuum is unstable; if it has a mass below 90 GeV (i.e. within reach of LEP within the next two years), then the instability will occur at a scale between 800 GeV and 10 TeV. We show that precise determinations of the Higgs and top quark masses as well as more detailed effective potential calculations will enable one to pin down the location of the instability to an accuracy of about 25 percent. It is often said that “the standard model must break down” or “new physics must enter” by that scale. However, by considering a toy model for the new physics, we argue that it is possible that the effects of such new physics would not be detectable until energies as much as an order of magnitude greater than the location of the instability are reached.
A Test Time Theorem and its Applications

Power dissipated during test is a constraint when it comes to test time reduction. In this work, we show that for a given test the minimum test application time is achieved when the total energy is dissipated evenly at the rate of the maximum allowable power for the device under test. This result, the test time theorem, leads to two alternatives for reducing test time. In the first alternative, we scale the supply voltage down to reduce power, which in turn allows us to increase the clock frequency, of course within the limit imposed by the critical path. Thus, optimum voltage and frequency can be found to minimize the test time of a fixed frequency synchronous test. In the other alternative, which also benefits from the reduced voltage, the clock period is dynamically varied so that each cycle dissipates the maximum allowable power. This test, termed aperiodic clock test, according to the theorem achieves the lower bound on test time. An illustrative example of an ISCAS'89 benchmark circuit shows a test time reductionof 71 %.
Quantifying comparisons of threshold resummations

We explore similarities and differences between widely-used threshold resummation formalisms, employing electroweak boson production as an instructive example. Resummations based on both full QCD and soft-collinear effective theory (SCET) share common underlying factorizations and resulting evolution equations. The formalisms differ primarily in their choices of boundary conditions for evolution, in moment space for many treatments based on full QCD, and in momentum space for treatments based on soft-collinear effective theory. At the level of factorized hadronic cross sections, these choices lead to quite different expressions. Nevertheless, we can identify a natural expansion for parton luminosity functions, in which SCET and full QCD resummations agree for the first term, and for which subsequent terms provide differences that are small in most cases. We also clarify the roles of the non-leading resummation constants in the two formalisms, and observe a relationship of the QCD resummation function D(α s ) to the web expansion.
Housing, Natural Hazards, and Insurance

Abstract This paper describes residential development and location choice within a community subject to future natural hazards of uncertain severity. This is accomplished by constructing an equilibrium model of housing markets in which locations are differentiated by both risk of loss due to natural hazards and distance from a central business district. In this context, households trade–off location and risk amenities, allowing for the possibility that areas within the outer boundary of the community will be left undeveloped in equilibrium. General equilibrium comparative statics are derived in economies both with and without insurance. Emphasis is placed on describing the impact of variables such as population and income on the development of hazardous areas.
Policy, values and EFT research: anatomy of a research agenda

In its Final Report of February 1977, the National Commission on Electronic Fund Transfers (NCEFT) defined EFT as:"... a payments system in which the processing and communications necessary to effect economic exchange, and the processing and communications necessary for the production and distribution of services incidental or related to economic exchange, are dependent wholly or in large part on the use of electrons."
Aerospace plane design challenge - Credible computations

Computational fluid dynamics (CFD) is necessary in the design processes of all current aerospace plane programs. Single-stage-to-orbit (SSTO) aerospace planes with air-breathing supersonic and hypersonic combustion are going to be largely designed by means of CFD. The principal challenge of the aerospace plane design is to provide credible CFD results to work from, to assess the risk associated with the use of those results, and to certify CFD codes that produce credible results. CFD uncertainties, credibility requirement, a guide for establishing credibility, and responsibility for credibility are discussed in order to establish the credibility of CFD results used in design. Quantification of CFD uncertainties helps to assess success risks and safety risks, and the development of CFD as a design tool requires code certification. This credibility challenge is managed by "designing" the designers to use CFD effectively, by teaming the computational fluid dynamicists with the designers, by ensuring continuous enhancement of credibility, and by balancing the design process to achieve a judicious balance of computations and measurements.
Intramolecular Barbier reaction of a 3-(3'-bromopropyl) bicyclo[2.2.2]oct-5-en-2-one

Intramolecular Barbier reactions, initiated with lithium or magnesium metals, were carried out on a model compound 3 and afforded four products, including the cyclic product 6 and cyclopropane-containing product 7. Single and double electron transfer sequences are proposed to explain their formation.
GOVERNMENT PUBLICATIONS AND THE LIBRARY: IMPLICATIONS FOR CHANGE

Abstract This article, based on a speech delivered in May 1977 before the Federal Publishing, Printing and Information Policy Institute, American University, notes the problems facing libraries in the acquisition and dissemination of government publications. Government publications comprise an information resource whose incorporation into the mainstream of library services should be a priority goal for both government and libraries.
The length of closed geodesics on random Riemann surfaces

Short geodesics are important in the study of the geometry and the spectra of Riemann surfaces. Bers’ theorem gives a global bound on the length of the first 3g − 3 geodesics. We use Brooks and Makover’s construction of random Riemann surfaces to investigate the distribution of short (< log(g)) geodesics on random Riemann surfaces. We calculate the expected value of the shortest geodesic, and show that if one orders geodesics by length $${\gamma_1\le \gamma_2\le \cdots \le \gamma_i ,\ldots}$$ , then for fixed k, if one allows the genus to go to infinity, the length of γ k is independent of the genus.
Heteroligated supramolecular coordination complexes formed via the halide-induced ligand rearrangement reaction.

Supramolecular coordination chemistry allows researchers to synthesize higher-order structures that approach the nanoscale dimensions of small enzymes. Frequently, such structures have highly symmetric macrocyclic square or cage shapes. To build functional structures that mimic the complex recognition, catalytic, and allosteric properties of enzymes, researchers must do more than synthesize highly symmetric nanoscale structures. They must also simultaneously incorporate different functionalities into these structures and learn how to regulate their relative arrangement with respect to each other. Designing such heteroligated coordination complexes remains a significant challenge for supramolecular chemists. This Account focuses on the discovery and development of a novel supramolecular reaction known as the halide-induced ligand rearrangement (HILR) reaction. Two hemilabile ligands with different binding strengths combine with d8 transition metal precursors that contain halide ions. The reaction spontaneo...
Titanium(IV)-mediated tandem deprotection-cyclodehydration of protected cysteine N-amides: biomimetic syntheses of thiazoline- and thiazole-containing heterocycles.

The scope and limitations of TiCl4-mediated Δ2-thiazoline synthesis via tandem deprotection−dehydrocyclization of trityl-protected cysteine N-amides is presented. While chemical yields are acceptable (53−96%), the stereochemical outcomes vary on the basis of structural considerations and reaction conditions (22−99% ee). Racemization at the C(2)-exomethine position limits the utility of this method for the formation of a thiazoline within a peptide. Treatment of a tritylated Cys-Cys dipeptide with TiCl4 afforded the corresponding thiazole−thiazoline heterocycle 12 (38% yield, 97% ee).
On Connecting Modules Together Uniformly to Form a Modular Computer

A modular computer may be informally defined to be a device consisting of a large (or infinite) number of identical circuit modules connected together in some uniform manner. This paper is concerned with making the concept of ``connected together in a uniform manner'' mathematically precise. Uniformity of connection in a modular device is first defined in terms of the linear graph whose vertices correspond to the modules and whose edges correspond to the cables connecting them. It is shown that the class of graphs satisfying the definition is precisely the class of group-graphs; that is, the vertices correspond to the elements of a group G, and there is a finite subset G 0 of G? (1 ? G 0 ) such that {g, g?} is an edge of the graph if, and only if, there exists g 0 in G 0 such that g?. = gg 0 . It is then shown that restricting the group G to be Abelian restricts the patterns of simultaneous activity which may occur within the computer.
On Einstein Causality and Time Asymmetry in Quantum Physics

A theorem of Hegerfeldt shows that if the spectrum of the Hamiltonian is bounded from below, then the propagation speed of certain probabilities does not have an upper bound. We prove a theorem analogous to Hegerfeldt's that appertains to asymmetric time evolutions given by a semigroup of operators. As an application, we consider a characterization of relativistic quasistable states by irreducible representations of the causal Poincare semigroup and study the implications of the new theorem for this special case.
Ignition of Lean Methane-Based Fuel Blends at Gas Turbine Pressures

Shock-tube experiments and chemical kinetics modeling were performed to further understand the ignition and oxidation kinetics of lean methane-based fuel blends at gas turbine pressures. Such data are required because the likelihood of gas turbine engines operating on CH 4 -based fuel blends with significant (>10%) amounts of hydrogen, ethane, and other hydrocarbons is very high. Ignition delay times were obtained behind reflected shock waves for fuel mixtures consisting of CH 4 , CH 4 /H 2 , CH 4 /C 2 H 6 , and CH 4 /C 3 H 8 in ratios ranging from 90/10% to 60/40%. Lean fuel/air equivalence ratios (Φ=0.5) were utilized, and the test pressures ranged from 0.54 to 30.0 atm. The test temperatures were from 1090 K to 2001 K. Significant reductions in ignition delay time were seen with the fuel blends relative to the CH 4 -only mixtures at all conditions. However, the temperature dependence (i.e., activation energy) of the ignition times was little affected by the additives for the range of mixtures and temperatures of this study. In general, the activation energy of ignition for all mixtures except the CH 4 /C 3 H 8 one was smaller at temperatures below approximately 1300 K (∼27 kcal/mol) than at temperatures above this value (∼41 kcal/mol). A methane/hydrocarbon-oxidation chemical kinetics mechanism developed in a recent study was able to reproduce the high-pressure, fuel-lean data for the fuel/air mixtures. The results herein extend the ignition delay time database for lean methane blends to higher pressures (30 atm) and lower temperatures (1100 K) than considered previously and represent a major step toward understanding the oxidation chemistry of such mixtures at gas turbine pressures. Extrapolation of the results to gas turbine premixer conditions at temperatures less than 800 K should be avoided however because the temperature dependence of the ignition time may change dramatically from that obtained herein.
A CONSISTENT MARKOV PARTITION PROCESS GENERATED FROM THE PAINTBOX PROCESS

We study a family of Markov processes on P(k), the space of partitions of the natural numbers with at most k blocks. The process can be constructed from a Poisson point process on R+ x ∏i=1kP(k) with intensity dt ⊗ ϱν(k), where ϱν is the distribution of the paintbox based on the probability measure ν on Pm, the set of ranked-mass partitions of 1, and ϱν(k) is the product measure on ∏i=1kP(k). We show that these processes possess a unique stationary measure, and we discuss a particular set of reversible processes for which transition probabilities can be written down explicitly.
A polyethylene-bound ruthenium(II) catalyst for inter- and intramolecular kharasch reactions

Abstract The preparation of a soluble, recoverable polyethylene-bound ruthenium(II) catalyst which is effective for both inter- and intramolecular additions of halocarbons to olefins (Kharasch reaction) is outlined.
Cyclization of a cysteine conjugate of N‐(3,5‐Dichlorophenyl)succinimide

N-(3,5-Dichlorophenyl)-2-cysteinylsuccinimide methyl ester hydrochloride (5) was prepared from N-(3,5-dichlorophenyl)maleimide (3) and cysteinyl methyl ester hydrochloride. Attempted neutralization of the cysteine conjugate salt with triethylamine resulted in spontaneous cyclization of 5 to form the more stable 2-(N-3,5-dichlorophenylcarbamoylmethyl)-5-carbomethoxy-1,4-thiazine- 3-one (6). Similar results might be expected in vivo should these metabolites of succinimides be formed.
Boron-Bridged Group-4 ansa-Metallocene Complexes

Boron-bridged group-4 ansa-metallocene complexes are newcomers to the field of metallocene-mediated olefin polymerization catalysis. Because of the Lewis acidity of the boron bridge, it is more reactive than the more common carbon and silicon bridges. It is also more vulnerable to cleavage from the ligand framework by nucleophilic agents. A primary goal of our work is to involve the boron bridge more actively in the reaction chemistry of the metallocene while keeping the bridge intact.
Microemulsion polymerization of styrene

Initiation of polymerization in styrene oil-in-water microemulsions by water-soluble potassium persulfate of oil-soluble 2,2′-azobis-(2-methyl butyronitrile) at 70°C gave stable latexes which were bluish and less translucent than the original microemulsions. The effects of initiator concentration, polymerization temperature, and monomer concentration on the kinetics, particle size distributions, and molecular weight distributions were investigated. The kinetics of polymerization were measured by dilatometry. In all cases, the polymerization rate shows only two intervals, which increased to a maximum and then decreased. There was no apparent constant rate period and no gel effect. A longer nucleation period was found for polymerizations initiated by potassium persulfate as compared to 2,2′-azobis-(2-methyl butyronitrile). The small latex particle size (20–30 nm) and high polymer molecular weight (1–2 × 106) implies that each latex particle consists of two or three polystyrene molecules. The maximum polymerization rate and number of particles varied with the 0.47 and 0.40 powers of potassium persulfate concentration, and the 0.39 and 0.38 powers of 2,2′-azobis-(2-methyl butyronitrile) concentration, respectively. This is consistent with the 0.4 power predicted by Smith–Ewart Case 2 kinetics. Microemulsion polymerizations of styrene–toluene mixtures at the same oil-water phase ratio gave lower polymerization rates and lower molecular weights, but the same latex particle size as with styrene alone. A mechanism is proposed, which comprised initiation and polymerization in the microemulsion droplets, by comparing the kinetics of microemulsion polymerization with conventional emulsion and miniemulsion polymerization systems.
Randomness in arithmetic and the decline and fall of reductionism in pure mathematics

Lecture given Thursday 22 October 1992 at a Mathematics-Computer Science Colloquium at the University of New Mexico. The lecture was videotaped; this is an edited transcript.
Duality-invariant non-extreme black holes in toroidally compactified string theory

Abstract We present a duality-invariant structure of the thermodynamic quantities of non-extreme black hole solutions of toroidally compactified Type II (M-theory) and heterotic string in five and four dimensions. These quantities are parametrized by duality-invariant combination of charges and the non-extremality parameter, which measures a deviation from the BPS-saturated limit. In particular, in D = 5 we find explicit S - and T -duality- [ U -duality-invariant expressions for solutions of toroidally compactified heterotic string [Type II string]. In D = 4, we consider general S -duality-invariant expressions for non-extreme solutions of pure N = 4 supergravity and find to the leading order in non-extremality parameter the T - and S -duality-invariant expressions of toroidally compactified heterotic string. General non-extreme solutions of toroidally compactified string in D = 4 are awaiting further investigation.
The lack of rotation in the Trouton?Noble experiment

The absence of any tendency toward rotation in the Trouton?Noble experiment is given a simple explanation.
Magnetoresistance of the double-tunnel-junction Coulomb blockade with magnetic metals

We have studied the junction magnetoresistance (JMR) and the differential junction magnetoresistance (DJMR) for double tunnel junctions with magnetic metals in the Coulomb blockade regime. Spikes are seen in both the JMR and the DJMR vs voltage curves. They occur at those places where the current increases by a step. In all cases the large bias limit can be obtained by adding the resistances of each of the junctions in series. The JMR is positive in all the cases we studied, whereas the DJMR can be positive or negative as a function of the voltage. Moreover, the relative variation of the DJMR as a function of the voltage is larger than the variation of the JMR with the voltage.
The Length of the Longest Increasing Subsequence of a Random Mallows Permutation

The Mallows measure on the symmetric group S n is the probability measure such that each permutation has probability proportional to q raised to the power of the number of inversions, where q is a positive parameter and the number of inversions of π is equal to the number of pairs i<j such that π i >π j . We prove a weak law of large numbers for the length of the longest increasing subsequence for Mallows distributed random permutations, in the limit that n→∞ and q→1 in such a way that n(1−q) has a limit in R.
The no-core shell model with general radial bases

Calculations in the ab initio no-core shell model (NCSM) have conventionally been carried out using the harmonic-oscillator many-body basis. However, the rapid falloff (Gaussian asymptotics) of the oscillator functions at large radius makes them poorly suited for the description of the asymptotic properties of the nuclear wavefunction. We establish the foundations for carrying out no-core configuration interaction (NCCI) calculations using a basis built from general radial functions and discuss some of the considerations which enter into using such a basis. In particular, we consider the Coulomb-Sturmian basis, which provides a complete set of functions with a realistic (exponential) radial fallof.
A Cross-Section Analysis of the Income Elasticity of Housing Demand in Spain: Is There a Real Estate Bubble?

Much attention has been given to claims that real estate prices in Spain are overvalued in relation to income and how plummeting house prices can jeopardize the economy (The Economist, 2003 and IMF, 2004). The measure of income elasticity on housing expenditure is often of considerable interest to applied researchers and policy makers in real estate economics, but the problem of omitted variables in some estimation techniques can lead to severe biases. In this paper we estimate the income elasticity of the demand for housing in Spain based on the cross-section of prices and income in fifty Spanish provinces from 1996 to 2002. In comparison to long-run equilibrium models fitted with time-series data, our results show a much weaker role of income growth as a vehicle for house price increases in the long run. According to our estimates, the rate of growth of house prices in Spain between 1998 and 2003 points to a real estate bubble with prices above the long-term equilibrium level.
Enantioselective synthesis of cyclic enol ethers and all-carbon quaternary stereogenic centers through catalytic asymmetric ring-closing metathesis.

The first examples of catalytic asymmetric ring-closing metathesis (ARCM) reactions of enol ethers are reported. To identify the most effective catalysts, various chiral Mo- and Ru-based catalysts were screened. Although chiral Ru catalysts (those that do not bear a phosphine ligand) promote ARCM in some cases, such transformations proceed in 98%).
Doping Golden Buckyballs: Cu@Au16− and Cu@Au17− Cluster Anions

The discovery of the unique catalytic effects of gold nanoparticles on oxide substrates has stimulated a flurry of research into the structures and properties of free gold nanoclusters, which may hold the key to elucidating the catalytic mechanisms of supported gold clusters. One of the most remarkable results has been the discovery of planar gold cluster anions (Aun_) of up to twelve gold atoms and the 2D to 3D transition for clusters with n larger than 12. Among larger gold clusters, Au20 has been found to be a perfect tetrahedron. A more recent study of the structures of Aun_ cluster anions in the medium size range (n=15–19) has shown that clusters with n=16–18 possess unprecedented empty cage structures. In particular, the Au16_ cluster anion has an interesting tetrahedral structure with an inner diameter of about 5.5 0 and can be compared to the fullerenes (buckyballs). Although Au32 was first suggested to be a “24- carat golden fullerene”, subsequent studies showed that the Au32_ ion is in fact a low-symmetry compact 3D structure. Other larger gold cage clusters have also been proposed computationally, but none has been observed or is expected to be the global minimum. The cage structures of themore » cluster anions Au16_ and Au17_ have recently been confirmed by electron diffraction and thus they are the first experimentally confirmed and the smallest possible gold cages. The large empty space inside these cage clusters immediately suggested that they can be doped with a foreign atom to produce a new class of endohedral gold cages analogous to endohedral fullerenes.« less
Effect of physical inactivity on major non-communicable diseases worldwide: an analysis of burden of disease and life expectancy

Summary Background Strong evidence shows that physical inactivity increases the risk of many adverse health conditions, including major non-communicable diseases such as coronary heart disease, type 2 diabetes, and breast and colon cancers, and shortens life expectancy. Because much of the world's population is inactive, this link presents a major public health issue. We aimed to quantify the effect of physical inactivity on these major non-communicable diseases by estimating how much disease could be averted if inactive people were to become active and to estimate gain in life expectancy at the population level. Methods For our analysis of burden of disease, we calculated population attributable fractions (PAFs) associated with physical inactivity using conservative assumptions for each of the major non-communicable diseases, by country, to estimate how much disease could be averted if physical inactivity were eliminated. We used life-table analysis to estimate gains in life expectancy of the population. Findings Worldwide, we estimate that physical inactivity causes 6% (ranging from 3·2% in southeast Asia to 7·8% in the eastern Mediterranean region) of the burden of disease from coronary heart disease, 7% (3·9–9·6) of type 2 diabetes, 10% (5·6–14·1) of breast cancer, and 10% (5·7–13·8) of colon cancer. Inactivity causes 9% (range 5·1–12·5) of premature mortality, or more than 5·3 million of the 57 million deaths that occurred worldwide in 2008. If inactivity were not eliminated, but decreased instead by 10% or 25%, more than 533 000 and more than 1·3 million deaths, respectively, could be averted every year. We estimated that elimination of physical inactivity would increase the life expectancy of the world's population by 0·68 (range 0·41–0·95) years. Interpretation Physical inactivity has a major health effect worldwide. Decrease in or removal of this unhealthy behaviour could improve health substantially. Funding None.
Stable scheduling policies for fading wireless channels

We study the problem of stable scheduling for a class of wireless networks. The goal is to stabilize the queues holding information to be transmitted over a fading channel. Few assumptions are made on the arrival process statistics other than the assumption that their mean values lie within the capacity region and that they satisfy a version of the law of large numbers. We prove that, for any mean arrival rate that lies in the capacity region, the queues will be stable under our policy. Moreover, we show that it is easy to incorporate imperfect queue length information and other approximations that can simplify the implementation of our policy.
Effects of simultaneous switching noise on the tapered buffer design

Complementary metal-oxide-semiconductor (CMOS) output buffers, comprised of a series of tapered inverters, are used to drive large off-chip capacitances. The ratio of the size of transistors between two consecutive stages is the buffer taper factor. With higher frequency of operation and simultaneous switching of the output drivers, the parasitic inductance present at the pin-pad-package interface results in significant switching noise on the power lines. A comprehensive analysis and estimate of simultaneous switching noise (SSN) including the velocity saturation effects seen in the submicron transistors during the switching of output drivers is presented. The effect of SSN on the overall buffer propagation delay and transition time is discussed. The presence of SSN results in an increase in the optimum taper factor between inverter stages for a given capacitive load. Beyond a critical value, the output transition time of a tapered buffer increases with reducing taper factor due to SSN. SSN can be reduced by skewing the switching of output buffers, SPICE simulation results show that skewing buffer switching with additional inverter stages reduces SSN and increases buffer propagation delay.
THE COSMIC BARYON BUDGET

We present an estimate of the global budget of baryons in all states, with conservative estimates of the uncertainties, based on all relevant information we have been able to marshal. Most of the baryons today are still in the form of ionized gas, which contributes a mean density uncertain by a factor of about 4. Stars and their remnants are a relatively minor component, comprising for our best-guess plasma density only about 17% of the baryons, while populations contributing most of the blue starlight comprise less than 5%. The formation of galaxies and of stars within them appears to be a globally inefficient process. The sum over our budget, expressed as a fraction of the critical EinsteinEde Sitter density, is in the range with a best guess of (at Hubble constant 70 km 0.007 ( ) B ( 0.041, ) B D 0.021 s~1 Mpc~1). The central value agrees with the prediction from the theory of light element production and with measures of the density of intergalactic plasma at redshift z D 3. This apparent concordance suggests that we may be close to a complete survey of the major states of the baryons. Subject headings: cosmology: observations E elementary particles E galaxies: fundamental parameters
The complexity of social coordination

Coordination is a challenging everyday task; just think of the last time you organized a party or a meeting involving several people. As a growing part of our social and professional life goes online, an opportunity for an improved coordination process arises. Recently, Gupta et al. proposed entangled queries as a declarative abstraction for data-driven coordination, where the difficulty of the coordination task is shifted from the user to the database.Unfortunately, evaluating entangled queries is very hard, and thus previous work considered only a restricted class of queries that satisfy safety (the coordination partners are fixed) and uniqueness (all queries need to be satisfied).In this paper we significantly extend the class of feasible entangled queries beyond uniqueness and safety. First, we show that we can simply drop uniqueness and still efficiently evaluate a set of safe entangled queries. Second, we show that as long as all users coordinate on the same set of attributes, we can give an efficient algorithm for coordination even if the set of queries does not satisfy safety. In an experimental evaluation we show that our algorithms are feasible for a wide spectrum of coordination scenarios.
Unusual band dispersion in Pb films on Si(111)

Atomically uniform Pb films are prepared on Si(111), and the quantum-well states corresponding to confined valence electrons in the film are probed by angle-resolved photoemission. The subband structure shows a free-electron-like dispersion near the zone center, but the dispersion turns sharply toward higher binding energies at larger in-plane momenta. The effective mass at the zone center shows large variations of up to a factor of 7, and in one instance, the sign of the effective mass is reversed. These anomalous results are explained in terms of the bulk band structures of Pb and Si and an anticrossing coupling.
In situ acoustic estimates of the swimbladder volume of Atlantic herring (Clupea harengus)

Acoustic measurements at 1.5-5 kHz on fish in the Gulf of Maine showed a swimbladder-resonance peak near 2.5 kHz at 160-190-m depth. Midwater trawls confirmed that the fish were likely to be Atlantic herring (Clupea harengus) of 19-29 cm length. Calculation using a model of swimbladder resonance gives swimbladder volumes of 1.2% of fish weight at 160-190 m. Extrapolation of this volume of gas using Boyle's Law suggests that at the sea surface, these herring would need to inflate their swimbladders by up to five to six times the volume required for neutral buoyancy. If these fish were to maintain this volume of gas with surface “gulping”, they would need to submerge from the sea surface with a 30% excess buoyancy. In general, swimbladders of the Clupeidae may have greater volumes of gas than if the fish were neutrally buoyant at the sea surface and the interpretation of HF-echosounder surveys may be additionally complex when the volume of gas and swimbladder volume are difficult to predict. Mechanisms of how herring obtain additional swimbladder gas are discussed.
Molecular weight dependence of the sintering‐flow behavior for particulate polystyrenes

A series of particulate anionic PSs having Mn values from 1900 to 350,000 has been observed visually on a hot-stage microscope at heating rates from 0.2 to 10 K/min. The temperature range over which the particles sinter, coalesce, and flow onto the glass slide is relatively narrow and reproducible. The temperature corresponding to a specific optical appearance is designated Tf (for flow temperature) and appears to represent an isoviscous state. It decreases as Mn−1 below Mc, and increases as Mn (or possibly Mw above Mc, where Mc is the entanglement molecular weight Tf values at 10 K/min are only slightly below TII temperatures observed by DSC and by torsional braid analysis. A plot of log heating rate versus Tf−1 with only five points for Mn = 17,100 is clearly non-Arrhenius and appears to follow a Vogel or WLF-type equation. Tf is greater than and distinct from Tg at all heating rates except as Mn becomes less than about 2000 where the two processes tend to merge. Tf is independent of the several substrates tested: glass, Mylar, carbon, mica, Al, Al2O3, and PS. Globule formation which occurs just below Tf is probably a surface tension phenomenon. Its temperature, Tg1, decreases as Mn−2/3 at Mn > Mc. It appears to represent an iso-surface tension state. Origins of the endothermic peak observed by DSC on powder on first heating and the endothermic slope change found with melted films on subsequent heatings are proposed. Observations of Tg1 and Tf were made on poly(p-methylstyrene) and poly(p-tert-butylstyrene) but will be reported elsewhere.
A self-reconfigurable camera array

This paper presents a self-reconfigurable camera array system that captures video sequences from an array of mobile cameras, renders novel views on the fly and reconfigures the camera positions to achieve better rendering quality. The system is composed of 48 cameras mounted on mobile platforms. The contribution of this paper is twofold. First, we propose an efficient algorithm that is capable of rendering high-quality novel views from the captured images. The algorithm reconstructs a view-dependent multi-resolution 2D mesh model of the scene geometry on the fly and uses it for rendering. The algorithm combines region of interest (ROI) identification, JPEG image decompression, lens distortion correction, scene geometry reconstruction and novel view synthesis seamlessly on a single Intel Xeon 2.4 GHz processor, which is capable of generating novel views at 4–10 frames per second (fps). Second, we present a view-dependent adaptive capturing scheme that moves the cameras in order to show even better rendering results. Such camera reconfiguration naturally leads to a nonuniform arrangement of the cameras on the camera plane, which is both view-dependent and scene-dependent.
Randomly Generated Nonlinear Transformations for Pattern Recognition

In many mathematical and engineering problems the solution is simpler after a transformation has been applied. A general method is proposed to find suitable transformations for discrete data in information processing problems. The main feature of the method is random perturbation of the data subject to constraints which ensure that, in the transformed space, the problem is in some sense simpler and that the local structure of the data is preserved. An application of this technique to pattern recognition is discussed where a transformation is found for the feature space such that classes, which are not linearly separable in the original space, become so in the transformed space. The transformation considerably simplifies the problem and allows well-developed linear discriminant techniques to be applied. This application was implemented and tested with a number of examples which are described.
An introduction to multichannel analyzers

Abstract A survey of the state of the art of multichannel pulse analysis is presented, intended chiefly for the reader with little prior knowledge of the field. There is no attempt to treat any topic in depth. The general principles of analysis of pulse height and time of flight are outlined, with consideration given both to single-parameter and multiparameter instruments. Memory systems, analog-to-digital conversion, and readout devices are discussed. Some of the features and limitations of modern analyzers are noted and typical performance specifications are given. Although the main emphasis is on instrumentation, mention is made of some of the applications of single- and multiparameter analysis.
AN IMPROVED SYNTHESIS OF HYPERICIN AND RELATED COMPOUNDS

(2000). AN IMPROVED SYNTHESIS OF HYPERICIN AND RELATED COMPOUNDS. Organic Preparations and Procedures International: Vol. 32, No. 1, pp. 57-61.
Optical frequency measurement and standards

This paper celebrates the progress in optical frequency standards and measurement, won by the 40 years of dedicated work of world-wide teams working in frequency standards and frequency measurement. Amazingly, after this time interval, the field is now simply exploding with new measurements and major advances of convenience and precision, with the best fractional frequency stability and potential frequency accuracy now being offered by optical systems. The new "magic" technology underlying the RF/optical connection is the capability of using femtosecond (fs) laser pulses to produce optical pulses so short their Fourier spectrum covers an octave bandwidth in the visible. These "white light" pulses are repeated at stable rates (/spl sim/100 MHz to 1 GHz, set by design), leading to an optical "comb" of frequencies with excellent phase coherence and stability and containing some millions of stable coherent optical frequencies. Optical-heterodyned differences between comb lines provides a frequency-related RF or microwave output with remarkably low added phase noise, such that in an optically-based atomic clock, the phase noise of the standards-grade microwave frequency reference dominates over that of optical reference and the fs "gear-box".
Dual algebraic structures for the two-level pairing model

Duality relations are explicitly established relating the Hamiltonians and basis classification schemes associated with the number-conserving unitary and number-nonconserving quasispin algebras for the two-level system with pairing interactions. These relations are obtained in a unified formulation for both bosonic and fermionic systems, with arbitrary and, in general, unequal degeneracies for the two levels. Illustrative calculations are carried out comparing the bosonic and fermionic quantum phase transitions.
DOES MARKET INCOMPLETENESS MATTER FOR ASSET PRICES

In this paper we argue that market incompleteness resulting from limited stock market participation is important for understanding the behavior of asset prices. (JEL: E32, E44, G12)
Torsion-Free Sheaves and Moduli of Generalized Spin Curves

This article treats compactifications of the space of generalized spin curves. Generalized spin curves, or r-spin curves, are pairs (X,L) with X a smooth curve and L a line bundle whose rth tensor power is isomorphic to the canonical bundle of X. These are a natural generalization of 2-spin curves (algebraic curves with a theta-characteristic), which have been of interest recently, in part because of their applications to fermionic string theory. Three different compactifications over Z[1/r], all using torsion-free sheaves, are constructed. All three yield algebraic stacks, one of which is shown to have Gorenstein singularities that can be described explicitly, and one of which is smooth. All three compactifications generalize constructions of Deligne and Cornalba done for the case when r=2.
METEOR-S WSDI: A Scalable P2P Infrastructure of Registries for Semantic Publication and Discovery of Web Services

Web services are the new paradigm for distributed computing. They have much to offer towards interoperability of applications and integration of large scale distributed systems. To make Web services accessible to users, service providers use Web service registries to publish them. Current infrastructure of registries requires replication of all Web service publications in all Universal Business Registries. Large growth in number of Web services as well as the growth in the number of registries would make this replication impractical. In addition, the current Web service discovery mechanism is inefficient, as it does not support discovery based on the capabilities of the services, leading to a lot of irrelevant matches. Semantic discovery or matching of services is a promising approach to address this challenge. In this paper, we present a scalable, high performance environment for Web service publication and discovery among multiple registries. This work uses an ontology-based approach to organize registries into domains, enabling domain based classification of all Web services. Each of these registries supports semantic publication and discovery of Web services. We believe that the semantic approach suggested in this paper will significantly improve Web service publication and discovery involving a large number of registries. This paper describes the implementation and architecture of the METEOR-S Web Service Discovery Infrastructure, which leverages peer-to-peer computing as a scalable solution.
Effects of Voltage: Unbalance and System Harmonics on the Performance of Doubly Fed Induction Wind Generators

Renewable energy harvesting is of prime interest in lieu of increasing demand for energy and high price of fossil fuels. Albeit the diminishing resources of petroleum and natural gas has given a renewed attention to the topic. Wind energy is by far the most accessible and efficient form of renewable energy forms given the state of technology in other renewable resources i.e., solar, fuel cells, etc. Over the past decade there have been significant advances on capturing wind energy using doubly fed induction generators (DFIG). The versatility of the DFIG in providing a controllable flow of active and reactive power to the system as well as its inherent low cost and minimum size power electronic converters has been the driving force in superior adequacy of this family of generators. However, as it has been noted in the literature, voltage unbalance and system harmonics can deteriorate the performance of DFIG by introducing unwanted torque harmonics and inaccuracy in generation of commanded active/reactive power. The present article will address this phenomenon from an electromagnetic and system analysis points of view. Simulation results are given to validate the claims.