cssi/SciSciGPT-SciSciNet huggingface dataset:
Formal-Language-Constrained Path Problems

Given an alphabet $\Sigma$, a (directed) graph G whose edges are weighted and $\Sigma$-labeled, and a formal language $L\subseteq\Sigma^*$, the formal-language-constrained shortest/simple path problem consists of finding a shortest (simple) path p in G complying with the additional constraint that l(p) \in L$. Here l(p) denotes the unique word obtained by concatenating the $\Sigma$-labels of the edges along the path p. The main contributions of this paper include the following: We show that the formal-language-constrained shortest path problem is solvable efficiently in polynomial time when L is restricted to be a context-free language (CFL). When L is specified as a regular language we provide algorithms with improved space and time bounds. In contrast, we show that the problem of finding a simple path between a source and a given destination is NP-hard, even when L is restricted to fixed simple regular languages and to very simple classes of graphs (e.g., complete grids). For the class of treewidth-bounded graphs, we show that (i) the problem of finding a regular-language-constrained simple path between source and destination is solvable in polynomial time and (ii) the extension to finding CFL-constrained simple paths is NP-complete. Our results extend the previous results in [SIAM J. Comput., 24 (1995), pp. 1235--1258; Proceedings of the 76th Annual Meeting of the Transportation Research Board, 1997; and Proceedings of the 9th ACM SIGACT-SIGMOD-SIGART Symposium on Database Systems, 1990, pp. 230--242]. Several additional extensions and applications of our results in the context of transportation problems are presented. For instance, as a corollary of our results, we obtain a polynomial-time algorithm for the best k-similar path problem studied in Proceedings of the 76th Annual Meeting of the Transportation Reasearch Board, 1997]. The previous best algorithm was given by [ Proceedings of the 76th Annual Meeting of the Transportation Research Board, 1997] and takes exponential time in the worst case.
Graded Causation and Defaults

Recent work in psychology and experimental philosophy has shown that judgments of actual causation are often influenced by consideration of defaults, typicality, and normality. A number of philosophers and computer scientists have also suggested that an appeal to such factors can help deal with problems facing existing accounts of actual causation. This article develops a flexible formal framework for incorporating defaults, typicality, and normality into an account of actual causation. The resulting account takes actual causation to be both graded and comparative. We then show how our account would handle a number of standard cases.
Vote elicitation: complexity and strategy-proofness

Preference elicitation is a central problem in AI, and has received significant attention in single-agent settings. It is also a key problem in multiagent systems, but has received little attention here so far. In this setting, the agents may have different preferences that often must be aggregated using voting. This leads to interesting issues because what, if any, information should be elicited from an agent depends on what other agents have revealed about their preferences so far. In this paper we study effective elicitation, and its impediments, for the most common voting protocols. It turns out that in the Single Transferable Vote protocol, even knowing when to terminate elicitation is N P-complete, while this is easy for all the other protocols under study. Even for these protocols, determining how to elicit effectively is N P-complete, even with perfect suspicions about how the agents will vote. The exception is the Plurality protocol where such effective elicitation is easy. We also show that elicitation introduces additional opportunities for strategic manipulation by the voters. We demonstrate how to curtail the space of elicitation schemes so that no such additional strategic issues arise.
A Framework for the Integrated Optimization of Charging and Power Management in Plug-in Hybrid Electric Vehicles

This paper develops a dynamic programming (DP)-based framework for simultaneously optimizing the charging and power management of a plug-in hybrid electric vehicle (PHEV). These two optimal control problems relate to activities of the PHEV on the electric grid (i.e., charging) and on the road (i.e., power management). The proposed framework solves these two problems simultaneously to avoid loss of optimality resulting from solving them separately. The framework furnishes optimal trajectories of PHEV states and control inputs over a 24-h period. We demonstrate the framework for 24-h scenarios with two driving trips and different power grid generation mixes. The results show that addressing the aforementioned optimization problems simultaneously can elucidate valuable insights. For example, for the chosen daily driving scenario, grid generation mixes, and optimization objective, it is shown that it is not always optimal to completely charge a battery before each driving trip. In addition, reduction in CO2 resulting from the synergistic interaction of PHEVs with an electric grid containing a significant amount of wind power is studied. The main contribution of this paper to the literature is a framework that makes it possible to evaluate tradeoffs between charging and on-road power management decisions.
Path-dependent and path-breaking change: reconfiguring business resources following acquisitions in the U.S. medical sector, 1978–1995

This paper studies how firms use acquisitions to achieve long-term business reconfiguration. We base the study in a routine-based perspective on business dynamics. We develop and test hypotheses concerning the relative extent of change by acquiring and non-acquiring businesses, focusing on product line addition, retention, and deletion as forms of changing resources. We develop and test hypotheses that compare and contrast resource-deepening and resource extension arguments. We test the hypotheses with data from more than 3000 firms that offered more than 200 product lines in the U.S. medical sector between 1978 and 1995. We find that acquisitions play a major role in business reconfiguration, offering opportunities for firms to both build on existing resources and obtain substantially different resources. Copyright © 2000 John Wiley & Sons, Ltd.
Dirac's Cosmology and Mach's Principle

THE dimensionless gravitational coupling constant with mp the mass of some elementary particle, for definiteness taken as the proton, is such a small number that its significance has long been questioned. Thus Eddington1 considered that all the dimensionless physical constants, including this one, could be evaluated as simple mathematical expressions. Dirac2 considered that such an odd number must be related to other numbers of similar size, characterizing the structure of the universe. However, most physicists seem to believe that a dimensionless constant, such as (1), is provided by Nature, cannot be calculated, and is not in any way related to other numbers.
FROM M-THEORY TO F-THEORY, WITH BRANES

Abstract A duality relationship between certain brane configurations in type HA and type IIB string theory is explored by exploiting the geometrical origins of each theory in M-theory. The configurations are dual ways of realizing the non-perturbative dynamics of four-dimensional N = 2 supersymmetric SU (2) gauge theory with four or fewer flavours of quark, and the spectral curve which organizes these dynamics plays a prominent role in each case. This is an illustration of how non-trivial F-theory backgrounds follow from M-theory ones, hopefully demystifying somewhat the origins of the former.
Asymmetric fluorination of enolates with N-fluoro 2,10- (3,3-dichlorocamphorsultam)

Abstract Asymmetric fluorination of enolates with nonracemic N-fluoro dichlorocamphorsultam 2b affords α-fluoro carbonyl compounds in good yield and up to 75% ee.
Liquidity of the treasury bill market and the term structure of interest rates

Abstract We model the term structure of interest rates on Treasury bills as attributable to transaction cost, in particular to the bid-ask spread on T-bills. Since the bid-ask spread on a bill is increasing in maturity, part of the term premium can be modeled as a premium for differential liquidity, the transaction cost difference between bills of different maturity. Empirical results show that the bid-ask spread on Treasury bills is priced in the bill market and accounts for a substantial portion of the term premium, sometimes to the exclusion of a risk premium in the term structure.
Conical Casimir pistons with hybrid boundary conditions

In this paper, we compute the Casimir energy and force for massless scalar fields endowed with hybrid boundary conditions, in the setting of the bounded generalized cone. By using spectral zeta function regularization methods, we obtain explicit expressions for the Casimir energy and force in arbitrary dimensions in terms of the zeta function defined on the piston. Our general formulas are, subsequently, specialized to the case in which the piston is modeled by a d-dimensional sphere. In this particular situation, explicit results are given for d = 2, 3, 4, 5.
Stereoselective synthesis of cis-substituted azetidinones from penicillin: A formal total synthesis of loracarbef

Abstract A new method for the synthesis of chiral azetidinones bearing a carbon-carbon bond at the 4-position is described. The preparation involves a stereoselective alkylation-reduction of a silylated 4-phenylsulfonyl azetidinone. The utility of this method was demonstrated by a formal total synthesis of loracarbef.
Internal control reporting differences among public and governmental auditors: The case of city and county Circular A-133 audits

Abstract We investigate potential differences in audit reporting outcomes between Circular A-133 audits performed by governmental auditors vs. those performed by certified public accounting (CPA) firms. Specifically, we investigate the association between auditor type and the likelihood of auditor-disclosed internal control concerns. We employ a cross-sectional sample of 13,386 single audit reports of US cities and counties during 2004–2006. In contrast to prior literature, the results indicate that in the post-Sarbanes–Oxley environment, CPA firms appear more likely to issue audit reports that identify internal control concerns than are governmental auditors in the context of Circular A-133 audits. The differences are more pronounced for larger CPA firms.
Implicit motivation to control prejudice.

Abstract This research examines whether spontaneous, unintentional discriminatory behavior can be moderated by an implicit (nonconscious) motivation to control prejudice. We operationalize implicit motivation to control prejudice (IMCP) in terms of an implicit negative attitude toward prejudice (NAP) and an implicit belief that oneself is prejudiced (BOP). In the present experiment, an implicit stereotypic association of Blacks (vs. Whites) with weapons was positively correlated with the tendency to “shoot” armed Black men faster than armed White men (the “Shooter Bias”) in a computer simulation. However, participants relatively high in implicit negative attitude toward prejudice showed no relation between the race-weapons stereotype and the shooter bias. Implicit belief that oneself is prejudiced had no direct effect on this relation, but the interaction of NAP and BOP did. Participants who had a strong association between self and prejudice (high BOP) but a weak association between prejudice and bad (low NAP) showed the strongest relation between the implicit race-weapons stereotype and the Shooter Bias, suggesting that these individuals freely employed their stereotypes in their behavior.
Hemispheric asymmetries in the longitudinal structure of the low‐latitude nighttime ionosphere

[1] Observations performed with the Low Resolution Airglow and Aurora Spectrograph (LORAAS), which flew aboard the Advanced Research and Global Observation Satellite (ARGOS), show evidence of wave number four longitudinal variations in the nighttime equatorial anomaly during March 2001 and March 2002. LORAAS limb scans of O I 135.6 nm emission features are used to reconstruct electron density profiles from which maps of the monthly average peak F region electron densities and heights at 0230 LT are generated. The longitudinal structure is nearly identical in both years. The locations of the longitudinal maxima in the Northern Hemisphere match that of previous studies, but the LORAAS data show a pronounced hemispheric asymmetry in the locations of the maxima in the Southern Hemisphere. The LORAAS results are compared with the International Reference Ionosphere (IRI-90) to show the derived electron densities and peak altitudes are consistent with the climatology, but that the observed longitudinal structure is not. A physics-based model of the ionosphere (Sami is Another Model of the Ionosphere (SAMI2)) is used to study the role of thermospheric neutral winds in generating the observed longitudinal pattern. It is demonstrated that longitudinally varying F region winds along with effects due to the offset of the geographic and magnetic equator are the plausible cause of the hemispheric asymmetry. Together, the effects enhance the observed wave number four pattern in the nighttime ionosphere.
Rating the rating agencies: Anticipating currency crises or debt crises?

Abstract We revisit the question whether sovereign ratings predict financial crises. In line with previous studies, we find that ratings do not predict currency crises and are instead downgraded ex-post. However, the likelihood of currency crisis and the implied probability of sovereign default are not closely linked in emerging markets post-1994. When debt crises are defined as sovereign distress – when spreads are higher than 1000 basis points or 10 percentage points – we find that access to international capital markets is reduced by half. In addition, although sovereign distress events last for typically 5.2 consecutive months, they can persist for longer periods up to nine quarters. Finally, lagged ratings and ratings changes, including negative outlooks and credit watches, are useful in anticipating sovereign distress.
Neurokinematic modeling of complex swimming patterns of the larval zebrafish

Larval zebrafish exhibit a variety of complex undulatory swimming patterns. This repertoire is controlled by the 300 neurons projecting from brain into spinal cord. Understanding how descending control signals shape the output of spinal circuits, however, is nontrivial. We have therefore developed a segmental oscillator model (using NEURON ) to investigate this system. We found that adjusting the strength of NMDA and glycinergic synapses enabled the generation of oscillation (tail-beat) frequencies over the range exhibited in different larval swim patterns. In addition, we developed a kinematic model to visualize the more complex axial bending patterns used during prey capture.
Minimal distortion morphs generated by time-dependent vector fields

Abstract A morph between two Riemannian n -manifolds is an isotopy between them together with the set of all intermediate manifolds equipped with Riemannian metrics. We propose measures of the distortion produced by some classes of morphs and diffeomorphisms between two isotopic Riemannian n -manifolds and, with respect to these classes, prove the existence of minimal distortion morphs and diffeomorphisms. In particular, we consider the class of time-dependent vector fields (on an open subset Ω of R n + 1 in which the manifolds are embedded) that generate morphs between two manifolds M and N via an evolution equation, define the bending and the morphing distortion energies for these morphs, and prove the existence of minimizers of the corresponding functionals in the set of time-dependent vector fields that generate morphs between M and N and are L 2 functions from [ 0 , 1 ] to the Sobolev space W 0 k , 2 ( Ω , R n + 1 ) .
Raiders of the lost AdS

We demonstrate that under certain conditions a theory of conformal quantum mechanics will exhibit the symmetries of two half-Virasoro algebras. We further demonstrate the conditions under which these algebras combine to form a single-Virasoro algebra, and comment on the connection between this result and the AdS2/CFT1 correspondence.
Synthesis of 2-imidazolones and 2-iminoimidazoles

Convenient methods for the direct conversion of imidazolium salts to the corresponding 2-imidazolone or 2-imino imidazole derivatives have been developed. Treatment of the salt with commercial bleach leads to effective oxidation at C2 and the formation of the corresponding imidazolone. Alternatively, treatment of the salt with an N-chloro amide affords the corresponding protected 2-amino derivative in good yield.
Highly Stereoselective Synthesis of cis-Alkenyl Pinacolboronates and Potassium cis-Alkenyltrifluoroborates via a Hydroboration/ Protodeboronation Approach

A number of alkynyl pinacolboronates bearing various functional groups were synthesized according to literature methods. These were then stereoselectively reduced to the cis-alkenyl pinacolboronates via hydroboration with dicyclohexylborane followed by chemoselective protodeboronation using acetic acid. Treatment with potassium hydrogen fluoride smoothly converted these to the corresponding potassium organotrifluoroborates.
Discovery of Some of the Biological Effects of Nitric Oxide and Its Role in Cell Signaling (Nobel Lecture)

A unique simple molecule with an array of signaling functions: NO. The free radical nitric oxide not only mediates a long list of biological effects by activating guanylyl cyclase and increasing cyclic GMP synthesis from GTP, but can also interact with transition metals such as iron, thiol groups, other free radicals, oxygen, superoxide anion, unsaturated fatty acids, and other molecules. Furthermore, NO can function as an intracellular messenger, an autacoid, a paracrine substance, a neurotransmitter, or a hormone that can be carried to distant sites for effects.
Spatial correlation of the topological charge in pure SU(3) gauge theory and in QCD

Abstract We study the spatial correlator of the topological charge density operator in pure SU(3) gauge theory and in two flavor QCD. We show that the data for distances up to about 1 fm is consistent with a vacuum consisting of individual instantons and closely bound pairs. The percentage of paired objects is twice as large on the dynamical configurations than on the pure gauge ones, implying increased molecule formations due to fermionic interactions.
Continuous Time Markov Processes on Graphs

Abstract We study continuous time Markov processes on graphs. The notion of frequency is introduced, which serves well as a scaling factor between any Markov time of a continuous time Markov process and that of its jump chain. As an application, we study “multiperson simple random walks” on a graph G with n vertices. There are n persons distributed randomly at the vertices of G. In each step of this discrete time Markov process, a randomly selected person is moved to one of the adjacent vertices selected randomly. We give estimate on the expected number of steps for these n persons to meet all together at a specific vertex, given that they are at different vertices at the begininng. For regular graphs, our estimate is exact.
On the Effects of Dissipative Turbulence on the Narrow Emission-Line Ratios in Seyfert Galaxies

We present a photoionization model study of the effects of microturbulence and dissipative heating on emission lines for number and column densities, elemental abundances, and ionizations typical for the narrow emission line regions (NLRs) of Seyfert galaxies. Earlier studies of NLR spectra generally found good agreement between the observations and the model predictions for most strong emission lines, such as [O III] λ5007, [O II] λ3727, [N II] λ6583, [Ne III] λ3869, and the H and He recombination lines. Nevertheless, the strengths of lines from species with ionization potentials greater than that of He+ (54.4 eV), e.g., N+4 and Ne+4, were often underpredicted. Among the explanations suggested for these discrepancies were (selectively) enhanced elemental abundances and contributions from shock-heated gas. Interestingly, the NLR lines have widths of several 100 km s-1, well in excess of the thermal broadening. If this is due to microturbulence, and the turbulence dissipates within the emission-line gas, the gas can be heated in excess of that due to photoionization. We show that the combined effects of turbulence and dissipative heating can strongly enhance N V λ1240 (relative to He II λ1640), while the heating alone can boost the strength of [Ne V] λ3426. We suggest that this effect is present in the NLR, particularly within ~100 pc of the central engine. Finally, since microturbulence would make clouds robust against instabilities generated during acceleration, it is not likely to be a coincidence that the radially outflowing emission-line gas is turbulent.
Cosmic strings and electroweak symmetry restoration in the two Higgs doublet model

We investigate the region of restored electroweak symmetry around a superconducting cosmic string coupled to the Weinberg-Salam model with an extra Higgs doublet. We show that the presence of the extra Higgs fields, and in particular their CP violating relative phase, does not qualitatively affect the results of Perkins and Davis1 obtained for the standard electroweak theory. This result is necessary to ensure the validity of some recently proposed string-mediated electroweak baryogenesis scenarios.
Design and Status of a Specialized Cyclotron for Positron Tomography

A specialized, small cyclotron has been developed for the sole objective of producing the principle isotopes used in positron tomography. The following features make it advantageous for clinical applications: 1) It is capable of producing high activity levels of the proper precursor chemical forms; 2) It is much smaller than other cyclotrons, having only slightly more than half the energy of the next smallest model in general use; 3) It is automated to operate under microprocessor control; 4) Its vertical beam plane design permits the external targetry to be recessed into the floor to minimize the amount of bulky neutron shielding material that must be added to the room; 5) It is a single particle accelerator, which simplifies the design and reduces the operational requirements; and 6) The translation of the cyclotron to various target positions permits the targetry with its many plumbing, gas transfer and electrical connections to remain stationary. The cyclotron is nearly ready for its in-factory acceptance tests, and installation is expected early next year in the Division of Biophysics of the University of California at Los Angeles. Following the installation, there will be a cooperative program between the Division of Biophysics and ORBIT, Inc. in the development of a microprocessor-controlled targetry and radiopharmaceutical synthesis system.
Shared Agency in Modest Sociality

A contribution to a symposium on Michael Bratman, Shared Agency: A Planning Theory of Acting Together.
Cosine Products, Fourier Transforms, and Random Sums

(1995). Cosine Products, Fourier Transforms, and Random Sums. The American Mathematical Monthly: Vol. 102, No. 8, pp. 716-724.
Solution Synthesis of Nanocrystalline M−Zn (M = Pd, Au, Cu) Intermetallic Compounds via Chemical Conversion of Metal Nanoparticle Precursors

Alloys and intermetallic compounds offer a wide range of desirable physical and chemical properties. However, accessing these compounds as nanocrystals is not always straightforward, and the continued development of appropriate synthetic pathways is required. Developing processes that are general toward many systems can be particularly challenging, especially when trying to incorporate highly electropositive metals or metals whose precursors are difficult to reduce into alloy or intermetallic compounds using solution chemistry strategies. Here we report a generalized strategy to access nanocrystalline M−Zn intermetallics (M = Au, Cu, Pd) via the chemical conversion of metal nanoparticles using zerovalent organometallic zinc precursors. Using commercially available reagents, transition-metal nanocrystals are made in hot organoamine solvents, which can be further reacted with diethylzinc or diphenylzinc to form intermetallic AuZn, Au3Zn, Cu5Zn8, and PdZn. The reaction pathway from the single-metal precursor...
Synthesis of iodinated 3β-aryltropanes with selective binding to either the dopamine or serotonin transporters

Abstract Iodinated 3β-aryltropanes functionalized appropriately at the 2β-, 8- and aryl positions display selective binding to either the dopamine or serotonin transporters.
Supersymmetric quantum mechanical description of four dimensional black holes

By assuming the existence of a novel multipronged string state for D-particles interacting with D-brane intersections in type-IIA string theory, we are able to derive a quantum mechanical description of supersymmetric Reissner-Nordstrom black holes. A supersymmetric index calculation provides evidence for this conjecture. The quantum mechanical system becomes two decoupled conformal quantum mechanical systems in the low energy limit. The conformal quantum mechanics has expected properties of a dual description of string theory on AdS2 ? S2.
Monitoring of radiation therapy response of head and neck tumors by non-invasive optical blood flow measurements

The aim is to evaluate the usefulness of optical blood flow measurements for predicting early tumor response to radiation therapy in patients with head and neck tumors. The results suggest a correlation between tumor blood flow changes with clinical outcome.
Superficial Keratopathy in Intensive Care Unit Patients

Purpose To determine the prevalence of keratopathy in a randomly selected group of hospitalized patients in the intensive care unit and to identify factors associated with an increased incidence of corneal abnormalities. Methods We conducted bedside examinations with a portable slit lamp on 50 randomly selected patients. Evidence of superficial keratopathy was recorded. Associated factors analyzed included Glasgow Coma Scale, period in the intensive care unit, intubation status, underlying disease, and current eye care. Results Superficial keratopathy was present in 20 (40%) of the patients. Of these 20, 18 (90%) were intubated, whereas of the remaining 30 patients without corneal abnormalities, only 15 (50%) were intubated ( P P = .03). Twelve (60%) of the 20 patients with corneal abnormalities had Glasgow Coma Scale scores of 7 or less compared with seven (23%) of the 30 patients without corneal abnormalities ( P Conclusions The prevalence of corneal abnormalities in the critically ill patient reflects certain predictors of keratopathy, including the Glasgow Coma Scale, length of hospitalization, intubation, and significant metabolic derangement. More ophthalmologic attention must be given to patients in intensive care units to prevent the development of ocular disease.
Time-Variability in the Interstellar Boundary Conditions of the Heliosphere: Effect of the Solar Journey on the Galactic Cosmic Ray Flux at Earth

During the solar journey through galactic space, variations in the physical properties of the surrounding interstellar medium (ISM) modify the heliosphere and modulate the flux of galactic cosmic rays (GCR) at the surface of the Earth, with consequences for the terrestrial record of cosmogenic radionuclides. One phenomenon that needs studying is the effect on cosmogenic isotope production of changing anomalous cosmic ray fluxes at Earth due to variable interstellar ionizations. The possible range of interstellar ram pressures and ionization levels in the low density solar environment generate dramatically different possible heliosphere configurations, with a wide range of particle fluxes of interstellar neutrals, their secondary products, and GCRs arriving at Earth. Simple models of the distribution and densities of ISM in the downwind direction give cloud transition timescales that can be directly compared with cosmogenic radionuclide geologic records. Both the interstellar data and cosmogenic radionuclide data are consistent with two cloud transitions, within the past 10,000 years and a second one 20,000–30,000 years ago, with large and assumption-dependent uncertainties. The geomagnetic timeline derived from cosmic ray fluxes at Earth may require adjustment to account for the disappearance of anomalous cosmic rays when the Sun is immersed in ionized gas.
Cycloaddition of enamines with alkynylphosphonates. A route to functionalized medium sized rings

Abstract Substituted seven and eight membered rings were formed from cyclopentanone and cyclo-hexanone via cycloadditions of pyrrolidine enamines with alkynyl phosphonates. This procedure provides straightforward access to functionalized medium sized rings that could be further manipulated in the synthesis of a number of natural products.
Macroeconomic forecasts under the prism of error-correction models

Abstract When the error correction term exhibits persistence, its change may convey useful information about short-run economic dynamics which, if not taken sufficiently into account by a forecasting model, may be associated with predictable forecast errors. Such errors are documented in the DRI forecasts for the U.S. consumption, GNP and imports. The strong results, together with the very general assumptions behind the conceptual framework, suggest that similar predictable errors may be pervasive in the forecasts of other large-scale econometric models.
Global-local methodologies and their application to nonlinear analysis

An assessment is made of the potential of different global-local analysis strategies for predicting the nonlinear and postbuckling responses of structures. Two postbuckling problems of composite panels are used as benchmarks and the application of different global-local methodologies to these benchmarks is outlined. The key elements of each of the global-local strategies are discussed and future research areas needed to realize the full potential of global-local methodologies are identified.
Synthesis and properties of melt-processable hyaluronan esters

A series of melt-processable hyaluronan (HA) esters were synthesized for potential biomedical applications (e.g., hot molding with thermoplastic ultra high molecular weight polyethylene for total joint replacements or molding tissue engineering scaffold). A silylated complex of HA with cetyltrimethylammonium cations (silyl HA-CTA) was used as the starting material. The reactions were performed with acid chlorides as the acylation agents in xylenes or no solvent other than the acid chloride. The disappearance of all characteristic FT-IR vibration bands associated with the –OSi(CH3)3 groups and the appearance of the strong ester carbonyl peak at 1753 cm− 1 demonstrated the success of esterification. Thermoplasticity was achieved when the length of aliphatic chains in the HA esters was equal to or greater than 10 carbon atoms. It was found that the longer the ester chain, the lower the melting point; thus, to meet various needs different melting temperatures can be obtained by adjusting the acid chloride chain length.
Spherically Symmetric Model Atmospheres for Low-Mass Pre-Main-Sequence Stars with Effective Temperatures between 2000 and 6800 K

We present a grid of spherically symmetric model atmospheres for young pre-MS stars. This grid spans the parameter range 2000 K ≤ Teff ≤ 6800 K and 2.0 ≤ log g ≤ 3.5 for M = 0.1 M☉, appropriate for low-mass stars and brown dwarfs. A major improvement is the replacement of TiO and H2O line lists with the newer line list, calculated by the NASA-Ames group, for TiO (about 175 million lines of five isotopes) and for H2O (about 350 million lines in two isotopes). We provide the model structures, spectra, and broadband colors in standard filters in electronic form.
Stabilized carbanions by alkyllithium-induced decarboxylation of non-enolizable carboxylic acids. An anionic equivalent to the hunsdiecker reaction

Abstract Intermediate dianions formed by nucleophilic attack of methyllithium on α-phenyl or α-phenylthio carboxylate salts fragment in highly coordinating solvents to produce stabilized carbanions. Once formed, these anions may be conveniently functionalized with various electrophilic reagents.
Droplet vaporization in supercritical pressure environments

Abstract For most liquid-fueled combustion systems the behavior of the fuel as it is introduced to the combustion zone, often by spray injection, will have a significant impact on combustion. The subsequent combustion may be affected to a considerable degree by the initial spread of the liquid, break-up of larger fuel sheets and droplets into droplets of various sizes, droplet vaporization, and diffusion of gaseous fuel. Among the many factors which affect spray break-up and droplet vaporization are the environmental conditions into which the spray is introduced. For both diesel engines and rockets the environment pressure and temperature may be above the critical pressure and temperature of the injected fuel. In a compression-ignition internal combustion engine, the environment consists primarily of air, at pressures from 20 to 100 atmospheres and temperatures ranging from 900 to 1500 K. Even higher pressures are encountered in turbocharged diesels. A typical diesel reference fuel, dodecane, has a thermodynamic critical pressure of about 17 atmospheres, and a critical temperature of 600 K. Fuel is injected into a diesel engine environment in which ambient pressures exceed the critical pressure. While droplet temperatures are subcritical at first, they may rise to the critical temperature or higher. This paper will survey current understanding of supercritical pressure droplet vaporization. Specifically, the topics covered will include: liquid phase behavior; vapor phase behavior; thermodynamic and transport properties; droplet distribution and break-up; micro-explosions; and effects of microgravity.
Growing distributed networks with arbitrary degree distributions

We consider distributed networks, such as peer-to-peer networks, whose structure can be manipulated by adjusting the rules by which vertices enter and leave the network. We focus in particular on degree distributions and show that, with some mild constraints, it is possible by a suitable choice of rules to arrange for the network to have any degree distribution we desire. We also describe a mechanism based on biased random walks by which appropriate rules could be implemented in practice. As an example application, we describe and simulate the construction of a peer-to-peer network optimized to minimize search times and bandwidth requirements.
Constructing and estimating a realistic optimizing model of monetary policy

Abstract A dynamic stochastic general-equilibrium (DSGE) model with real and nominal, both price and wage, rigidities succeeds in capturing some key nominal features of U.S. business cycles. Additive technology shocks, as well as multiplicative shocks, are introduced and shown to be crucial. Monetary policy is specified as an interest rate targeting rule following developments in the structural vector autoregression (VAR) literature. The interaction between real and nominal rigidities is essential to reproduce the liquidity effect of monetary policy. The model is estimated by maximum likelihood on U.S. data, and its fit is comparable to that of an unrestricted first-order VAR. Besides producing reasonable impulse responses and second moments, this model replicates a feature of U.S. business cycles, never captured by previous research with DSGE models, that an increase in interest rates predicts a decrease in output two to six quarters in the future.
The Johnson-Lindenstrauss Transform Itself Preserves Differential Privacy

This paper proves that an """"old dog"""", namely -- the classical Johnson-Linden Strauss transform, """"performs new tricks"""" -- it gives a novel way of preserving differential privacy. We show that if we take two databases, D and D', such that (i) D'-D is a rank-1 matrix of bounded norm and (ii) all singular values of D and D' are sufficiently large, then multiplying either D or D' with a vector of iid normal Gaussians yields two statistically close distributions in the sense of differential privacy. Furthermore, a small, deterministic and public alteration of the input is enough to assert that all singular values of D are large. We apply the Johnson-Linden Strauss transform to the task of approximating cut-queries: the number of edges crossing a (S, \bar S)-cut in a graph. We show that the JL transform allows us to publish a sanitized graph that preserves edge differential privacy (where two graphs are neighbors if they differ on a single edge) while adding only O(|S|/\epsilon) random noise to any given query (w.h.p). Comparing the additive noise of our algorithm to existing algorithms for answering cut-queries in a differentially private manner, we outperform all others on small cuts (|S| = o(n)). We also apply our technique to the task of estimating the variance of a given matrix in any given direction. The JL transform allows us to publish a sanitized covariance matrix that preserves differential privacy w.r.t bounded changes (each row in the matrix can change by at most a norm-1 vector) while adding random noise of magnitude independent of the size of the matrix (w.h.p). In contrast, existing algorithms introduce an error which depends on the matrix dimensions.
Use of HEPA filters to control ionizing radiation

This study summarizes the results of tests carried out at the Mackay School of Mines ventilation laboratory to determine the efficiency of dry filters to collect sub-micron size radioactive particles. In the study, two types of filters were tested: HEPA and fabric filters. The factors studied include the filter thickness and the pressure difference across the filter. The study discusses the results obtained and the effect of each factor on the filter efficiency.
On testing for sphericity with non-normality in a fixed effects panel data model

Abstract Building upon the work of Chen et al. (2010), this paper proposes a test for sphericity of the variance–covariance matrix in a fixed effects panel data regression model without the normality assumption on the disturbances.
On the exponentials of some structured matrices

This paper provides explicit techniques to compute the exponentials of a variety of structured 4 × 4 matrices. The procedures are fully algorithmic and can be used to find the desired exponentials in closed form. With one exception, they require no spectral information about the matrix being exponentiated. They rely on a mixture of Lie theory and one particular Clifford algebra isomorphism. These can be extended, in some cases, to higher dimensions when combined with techniques such as Givens rotations.
PHYSICAL PROPERTIES OF YOUNG BROWN DWARFS AND VERY LOW MASS STARS INFERRED FROM HIGH-RESOLUTION MODEL SPECTRA

By comparing near-infrared spectra with atmospheric models, we infer the effective temperature, surface gravity, projected rotational velocity, and radial velocity for 21 very low mass stars and brown dwarfs. The unique sample consists of two sequences in spectral type from M6-M9, one of 5-10 Myr objects and one of >1 Gyr field objects. A third sequence is comprised of only ~M6 objects with ages ranging from 1 Gyr. Spectra were obtained in the J band at medium (R ~ 2000) and high (R ~ 20,000) resolutions with NIRSPEC on the Keck II telescope. Synthetic spectra were generated from atmospheric structures calculated with the PHOENIX model atmosphere code. Using multi-dimensional least-squares fitting and Monte Carlo routines we determine the best-fit model parameters for each observed spectrum and note which spectral regions provide consistent results. We identify successes in the reproduction of observed features by atmospheric models, including pressure-broadened K I lines, and investigate deficiencies in the models, particularly missing FeH opacity, that will need to be addressed in order to extend our analysis to cooler objects. The precision that can be obtained for each parameter using medium- and high-resolution near-infrared spectra is estimated and the implications for future studies of very low mass stars and brown dwarfs are discussed.
Strength criteria for anisotropic brittle materials

On considere le critere de resistance des milieux anisotropes propose par Gol'deublat et Kopnov. On utilise les invariants ayant une symetrie isotrope transverse du materiau pour formuler un critere rationnel de resistance avec les effets de la contrainte hydrostatique et de Baushinger. Une fonction de resistance quadratique est formulee explicitement pour le milieu en terme de resistances de l'engineering. Exemple numerique
Using mixture-tuned match filtering to measure changes in subpixel vegetation area in Las Vegas, Nevada

In desert cities, accurate measurements of vegetation area within residential lots are necessary to understand drivers of change in water consumption. Most residential lots are smaller than an individual 30-m pixel from Landsat satellite images and have a mixture of vegetation and other land covers. Quantifying vegetation change in this environment requires estimating subpixel vegetation area. Mixture-tuned match filtering (MTMF) has been successfully used for subpixel target detection. There have been few successful applications of MTMF to subpixel abundance estimation because the relationship observed between MTMF estimates and ground measurements of abundance is noisy. We use a groundtruth dataset over 10times larger thanthat available for any previous MTMF application to estimate the bias between ground data and MTMF results. We find thatMTMFunderestimatesthe fractionalarea ofvegetationby5%to10% and show that averaging over multiple pixels is necessary to reduce noise in the dataset. We conclude that MTMF is a viable technique for fractional area estimation when a large dataset is available for calibration. When this method is applied to estimating vegetation area in Las Vegas, Nevada, spatial and temporal trends are consistent with expectations from known population growth and policy changes.©2014Society of Photo-Optical Instrumentation Engineers (SPIE) (DOI: 10.1117/1.JRS.8.083660)
Scalar Mesons, Glueballs, Instantons and the Glueball/Sigma

Abstract We include instanton effects in QCD sum rules for coupled scalar glueballs and mesons. We find a 400–600 MeV glueball as in earlier studies without instantons, and a possible explanation in terms of high-dimensional condensates for current lattice calculations not finding this glueball/sigma. In the 1–2 GeV region we now find that lightest I=0 meson, in the region of the f0(1370), has no direct glueball mixing, with the instanton loop replacing the glueball component. The lightest scalar mainly glueball in the region of the f0(1500) is sensitive to the choice of nonperturbative gluonic parameters.
Evidence and Implications of Pressure Fluctuations in the ISM

A recent survey of the fine-structure excitation of neutral carbon reveals that the interstellar medium in the Galactic plane exhibits a thermal pressure, nT/k, that ranges from about 103 to 104cm−3K from one location to the next, with occasional excursions in excess of about 105 cm−3 K. The large excitations for small amounts of gas indicate that some regions are either subjected to shocks or must be pressurized within time scales much shorter than the time needed to reach thermal equilibrium. These rapid fluctuations probably arise from the cascade of macroscopic mechanical energy to small scales through a turbulent cascade. One consequence of this effect is that changes in gas temperature can arise from near adiabatic compressions and expansions, and this may explain why investigations of 21-cm emission and absorption reveal the presence of hydrogen at temperatures well below the expected values derived from the balance of various known heating and cooling processes.
LIGHT QUARK MASSES AND MIXING ANGLES

I review the present state of our knowledge about the masses and weak mixing elements of the u, d, s quarks. This is the written version of lectures given at the 1993 Theoretical Advanced Study Institute (TASI).
EMBEDDING OF CYCLES AND GRIDS IN STAR GRAPHS

The use of the star graph as a viable interconnection scheme for parallel computers has been examined by a number of authors in recent times. An attractive feature of this class of graphs is that it has sublogarithmic diameter and has a great deal of symmetry akin to the binary hypercube. In this paper we describe a new class of algorithms for embedding (a) Hamiltonian cycle (b) the set of all even cycles and (c) a variety of two- and multi-dimensional grids in a star graph. In addition, we also derive an algorithm for the ranking and the unranking problem with respect to the Hamiltonian cycle.
The Tracking Index: A Generalized Parameter for α-β and α-β-γ Target Trackers

A generalized, optimal filtering solution is presented for the target tracking problem. Applying optimal filtering theory to the target tracking problem, the tracking index, a generalized parameter proportional to the ratio of the position uncertainty due to the target maneuverability to that due to the sensor measurement, is found to have a fundamental role not only in the optimal steady-state solution of the stochastic regulation tracking problem, but also in the track initiation process. Depending on the order of the tracking model, the tracking index solution yields a closed form, consistent set of generalized tracking gains, relationships, and performances. Using the tracking index parameter, an initializing and tracking procedure in recursive form, realizes the accuracy of the Kalman filter with an algorithm as simple as the well-known α-β filter or α-β-γ filter depending on the tracking order.
EVERY BCG WITH A STRONG RADIO AGN HAS AN X-RAY COOL CORE: IS THE COOL CORE-NONCOOL CORE DICHOTOMY TOO SIMPLE?

The radio active galactic nucleus (AGN) feedback in X-ray cool cores has been proposed as a crucial ingredient in the evolution of baryonic structures. However, it has long been known that strong radio AGNs also exist in "noncool core" clusters, which brings up the question whether an X-ray cool core is always required for the radio feedback. In this work, we present a systematic analysis of brightest cluster galaxies (BCGs) and strong radio AGNs in 152 groups and clusters from the Chandra archive. All 69 BCGs with radio AGN more luminous than 2 × 1023 W Hz–1 at 1.4 GHz are found to have X-ray cool cores. BCG cool cores can be divided into two classes: the large cool core (LCC) class and the corona class. Small coronae, easily overlooked at z > 0.1, can trigger strong heating episodes in groups and clusters, long before LCCs are formed. Strong radio outbursts triggered by coronae may destroy embryonic LCCs and thus provide another mechanism to prevent the formation of LCCs. However, it is unclear whether coronae are decoupled from the radio feedback cycles as they have to be largely immune to strong radio outbursts. Our sample study also shows the absence of groups with a luminous cool core while hosting a strong radio AGN, which is not observed in clusters. This points to a greater impact of radio heating on low-mass systems than clusters. Few L 1.4 GHz > 1024 W Hz–1 radio AGNs (~16%) host an L 0.5-10 keV > 1042 erg s–1 X-ray AGN, while above these thresholds, all X-ray AGNs in BCGs are also radio AGNs. As examples of the corona class, we also present detailed analyses of a BCG corona associated with a strong radio AGN (ESO 137-006 in A3627) and one of the faintest coronae known (NGC 4709 in the Centaurus cluster). Our results suggest that the traditional cool core/noncool core dichotomy is too simple. A better alternative is the cool core distribution function, with the enclosed X-ray luminosity or gas mass.