cssi/SciSciGPT-SciSciNet huggingface dataset:
Yield curve in an estimated nonlinear macro model

This paper estimates a sticky price macro model with US macro and term structure data using Bayesian methods. The model is solved by a nonlinear method. The posterior distribution of the parameters in the model is found to be bi-modal. The degree of nominal rigidity is high at one mode (“sticky price mode”) but is low at the other mode (“flexible price mode”). I find that the degree of nominal rigidity is important for identifying macro shocks that affect the yield curve. When prices are more flexible, a slowly varying inflation target of the central bank is the main driver of the overall level of the yield curve by changing long-run inflation expectations. In contrast, when prices are more sticky, a highly persistent markup shock is the main driver. The posterior probability of each mode is sensitive to the use of observed proxies for inflation expectations. Ignoring additional information from survey data on inflation expectations significantly reduces the posterior probability of the flexible price mode. Incorporating this additional information suggests that yield curve fluctuations can be better understood by focusing on the flexible price mode. Considering nonlinearities of the model solution also increases the posterior probability of the flexible price mode, although to a lesser degree than using survey data information.
Divergence and quasimorphisms of right-angled Artin groups

We give a group theoretic characterization of geodesics with superlinear divergence in the Cayley graph of a right-angled Artin group AΓ with connected defining graph. We use this to prove that the divergence of AΓ is linear if Γ is a join and quadratic otherwise. As an application, we give a complete description of the cut points in any asymptotic cone of AΓ. We also show that every non-abelian subgroup of AΓ has an infinite-dimensional space of non-trivial quasimorphisms.
Modeling of Atmospheric Turbulence as Disturbances for Control Design and Evaluation of High Speed Propulsion Systems

Atmospheric turbulence models are necessary for the design of both inlet/engine and flight controls, as well as for studying integrated couplings between the propulsion and the vehicle structural dynamics for supersonic vehicles. Models based on the Kolmogorov spectrum have been previously utilized to model atmospheric turbulence. In this paper, a more accurate model is developed in its representative fractional order form, typical of atmospheric disturbances. This is accomplished by first scaling the Kolmogorov spectral to convert them into finite energy von Karman forms. Then a generalized formulation is developed in frequency domain for these scale models that approximates the fractional order with the products of first order transfer functions. Given the parameters describing the conditions of atmospheric disturbances and utilizing the derived formulations, the objective is to directly compute the transfer functions that describe these disturbances for acoustic velocity, temperature, pressure and density. Utilizing these computed transfer functions and choosing the disturbance frequencies of interest, time domain simulations of these representative atmospheric turbulences can be developed. These disturbance representations are then used to first develop considerations for disturbance rejection specifications for the design of the propulsion control system, and then to evaluate the closed-loop performance.
Help your patient downsize with bariatric surgery.

Your patient has probably tried everything else. Now she's chosen to have weight-loss surgery. Do you know how to help her succeed?
The topology of rationally and polynomially convex domains

We give in this article necessary and sufficient conditions on the topology of a compact domain with smooth boundary in \({\mathbb {C}}^n\), \(n\ge 3\), to be isotopic to a rationally or polynomially convex domain.
Compress-and-forward scheme for a relay network: Approximate optimality and connection to algebraic flows

We study a wireless relay network, with a single source and a single destination. Our main result is to show that an appropriate compress-and-forward scheme supports essentially the same reliable data rate as the quantize-map-and-forward and noisy network coding schemes [1], [2]; thus, it is approximately optimal - in the sense the data rate is a universal constant away from the cut-set upper bound. We characterize the compress-and-forward scheme through an abstract flow formulation, a generalization of flow on linking systems. This characterization allows for efficient computation of the minimal amount of information that has to flow through each node in the network.
Robust weighted LAD regression

The least squares linear regression estimator is well-known to be highly sensitive to unusual observations in the data, and as a result many more robust estimators have been proposed as alternatives. One of the earliest proposals was least-sum of absolute deviations (LAD) regression, where the regression coefficients are estimated through minimization of the sum of the absolute values of the residuals. LAD regression has been largely ignored as a robust alternative to least squares, since it can be strongly affected by a single observation (that is, it has a breakdown point of 1/n, where n is the sample size). In this paper we show that judicious choice of weights can result in a weighted LAD estimator with much higher breakdown point. We discuss the properties of the weighted LAD estimator, and show via simulation that its performance is competitive with that of high breakdown regression estimators, particularly in the presence of outliers located at leverage points. We also apply the estimator to several data sets. ets.
Covering orthogonal polygons with star polygons: the perfect graph approach

Abstract This paper studies the combinatorial structure of visibility in orthogonal polygons. We show that the visibility graph for the problem of minimally covering simple orthogonal polygons with star polygons is perfect . A star polygon contains a point p , such that for every point q in the star polygon, there is an orthogonally convex polygon containing p and q . This perfectness property implies a polynomial algorithm for the above polygon covering problem. It further provides us with an interesting duality relationship. We first establish that a minimum clique cover of the visibility graph of a simple orthogonal polygon corresponds exactly to a minimum star cover of the polygon. In general, simple orthogonal polygons can have concavities (dents) with four possible orientations. In this case, we show that the visibility graph is weakly triangulated. We thus obtain an O(n 8 ) algorithm. Since weakly triangulated graphs are perfect, we also obtain an interesting duality relationship. In the case where the polygon has at most three dent orientations, we show that the visibility graph is triangulated or chordal. This gives us an O(n 3 ) algorithm.
Low energy excitations in graphite: The role of dimensionality and lattice defects

Abstract In this paper, we present a high resolution angle resolved photoemission spectroscopy (ARPES) study of the electronic properties of graphite. We found that the nature of the low energy excitations in graphite is particularly sensitive to interlayer coupling as well as lattice disorder. As a consequence of the interlayer coupling, we observed for the first time the splitting of the π bands by ≈0.7 eV near the Brillouin zone corner K. At low binding energy, we observed signatures of massless Dirac fermions with linear dispersion (as in the case of graphene), coexisting with quasiparticles characterized by parabolic dispersion and finite effective mass. We also report the first ARPES signatures of electron–phonon interaction in graphite: a kink in the dispersion and a sudden increase in the scattering rate. Moreover, the lattice disorder strongly affects the low energy excitations, giving rise to new localized states near the Fermi level. These results provide new insights on the unusual nature of the electronic and transport properties of graphite.
On generalized van der Waerden triples

Van der Waerden's classical theorem on arithmetic progressions states that for any positive integers k and r, there exists a least positive integer, w(k,r), such that any r-coloring of {1,2 .... ,w(k,r)} must contain a monochromatic k-term arithmetic progression {x,x + d, x + 2d,...,x + (k - 1)d}. We investigate the following generalization of w(3,r). For fixed positive integers a and b with a ≤ b, define N(a,b;r) to be the least positive integer, if it exists, such that any r-coloring of {1,2,...,N(a,b;r)} must contain a monochromatic set of the form {x, ax + d, bx + 2d}. We show that N(a, b; 2) exists if and only if b ≠ 2a, and provide upper and lower bounds for it. We then show that for a large class of pairs (a,b), N(a,b;r) does not exist for r sufficiently large. We also give a result on sets of the form {x,ax + d,ax + 2d ..... ax + (k - 1 )d}.
Butter and guns: Complementarity between economic and military competition

This paper analyses a general-equilibrium model of the complementarity between economic competition for the allegiance of subjects and military competition for the control of land. In our model economic competition between rival rulers for the allegiance of subjects results in their subjects, whether they are producers or soldiers, receiving incomes equal to the value of the marginal product of a producer. Furthermore, abstracting from destruction, military competition for the control of land, to the extent that it shifts some subjects from producing to soldiering, increases the value of the marginal product of a producer. Consequently, as long as military competition is not too destructive, the subjects of rival rulers have higher incomes with both military and economic competition than with economic competition alone. Economic competition for the allegiance of subjects causes rival rulers to bear all of the cost of allocating production to military competition and to bear more than the cost of the foregone production of soldiers.
Barriers to implementation of unconventional intersection designs: A survey of transportation professionals

Numerous unconventional intersection and interchange designs (UIIDs) exist with documented benefits, but implementation is slow. There are public, professional, and political barriers. Numerous papers explain the benefits of one design or compare designs, but few identify common barriers. This research surveyed transportation professionals to identify the barriers inhibiting the implementation of promising UIIDs and to identify solutions. Engineers believe that the public's main concerns are driver confusion and fear of the unknown. Survey results highlight education as important, and that public opinion generally improves once an UIID is constructed. Professionals and politicians want proof that a design will work and are reluctant to try nonstandard designs. An important political consideration is cost, but the life cycle cost can be competitive. We need guidelines to assist designers, increased focus on alternatives analysis, and inclusion of UIIDs in planning. This will make the designs more familiar to the public and decrease opposition. Language: en
The NASA airborne astronomy program - A perspective on its contributions to science, technology, and education

The scientific, educational, and instrumental contributions from NASA's airborne observatories are deduced from the program's publication record (789 citations, excluding abstracts, involving 580 authors at 128 institutions in the United States and abroad between 1967-1990).
Electrothermal Vaporization for Sample Introduction in Plasma Source Spectrometry

Abstract Electrothermal vaporization (ETV) as a sample introduction technique for plasma source spectrometry offers several advantages over traditional solution nebulization sample introduction methods. Because volatilization of the analyte occurs in the ETV device, the plasma is not required to desolvate the sample and, therefore, the plasma has greater energy available for atomization, ionization, and excitation. The furnace also offers the ability to separate sample matrix components from the analyte of interest, which causes a reduction in interferences in the emission or mass spectrum. Both of these advantages allow for improved detectability for most elements. ETV also allows for the analysis of solid samples with minimum sample pretreatment, which broadens the numbers of samples amenable to analysis by plasma spectrometry. In the nearly 20 years that have followed the first report of ETV as a sample introduction method for plasma sources, there has been extensive research improving the design of th...
Gas-phase perspective on the thermodynamics and kinetics of heterogeneous catalysis

Studies of small gas-phase transition metal cluster cations (2–18 atoms) are reviewed with an emphasis on the thermodynamic information acquired. For the metal–metal bond energies, the cluster results deviate from the bulk-phase enthalpy of vaporization in a manner than can be quantitatively described by the spherical drop model that accounts for the surface free energy using bulk-phase parameters (within 10–20%). Binding energies of atomic H and O adsorbates to such clusters are found to vary extensively for the smallest clusters and to reach values lying close to bulk-phase adsorbate energies for all five metal systems that have been investigated (V, Cr, Fe, Co, and Ni). For molecular fragments (C, CH, CH2, NH, and NH2), binding energies to clusters are also found to plateau for larger clusters (greater than about 10 atoms). These asymptotic values may be useful in estimating such quantities on surfaces. In the case of atomic N adsorbates, variations in the adsorbate energies with cluster size remain appreciable through the size range studied, which appears to be a consequence of activating the very strong N2 bond.
Development of Shyness: Relations With Children’s Fearfulness, Sex, and Maternal Behavior

The relations of childhood fearfulness (observed and adult reported) and adult-reported shyness at 18 (n = 256) and 30 (n = 230) months of age were assessed. Fear was positively related to shyness concurrently and longitudinally, but slightly more consistently at 18 months. The moderating roles of observed maternal sensitivity and children’s sex in the relation between 18-month fearfulness and 30-month shyness, and between 18- and 30-month shyness, were tested. The positive relation between mother-reported fearfulness and shyness was strongest for sons of insensitive mothers but was not significant for daughters of sensitive, average, or insensitive mothers. The positive relation between mother-reported 18- and 30-month shyness was strongest for sons of insensitive mothers and for daughters of sensitive mothers. Moreover, when using scores of fear or shyness that were independent of each other, 18-month mother-reported fearfulness continued to interact with sex and sensitivity to predict 30-month shyness; however, the positive relation between Time 1 and Time 2 shyness was consistent across sex and levels of sensitivity.
Comparison of fine structural mice via coarse iteration

Let $${\mathcal{M}}$$ M be a fine structural mouse. Let $${\mathbb{D}}$$ D be a fully backgrounded $${L[\mathbb{E}]}$$ L [ E ] -construction computed inside an iterable coarse premouse S. We describe a process comparing $${\mathcal{M}}$$ M with $${\mathbb{D}}$$ D , through forming iteration trees on $${\mathcal{M}}$$ M and on S. We then prove that this process succeeds.
Crystal Morphology Control by Melt Phase Separation in Biodegradable Polymer Blends

The effect of lower critical solution temperature (LCST) phase separation on the crystallization of poly(e-caprolactone) PCL in PCL/poly(D,L-lactide) (PDLA) blends is studied by simultaneous small-angle x-ray scattering (SAXS) and wide-angle x-ray scattering (WAXS). Phase separation is induced by controlled temperature jumps into the LCST (two-phase) region, which is above the melting temperature (60 °C) of PCL and the glass transition temperature (50 °C) of PDLA. We have followed the nanoscale structural changes (< 100 nm) during subsequent crystallization at 45 °C of critical (0.36 PCL) and off-critical (0.50 PCL) blend compositions in both one-phase and two-phase melts. The spherulite morphology (1–100 μm) is examined with optical microscopy. When crystallization follows LCST phase separation, the shape, size and distribution of the spherulites depends on the extent of melt phase separation. In our x-ray measurements, the WAXS crystallinity of PCL is less than 40 % for the temperature range of interest. We perform a correlation function and intensity model analysis of our SAXS data to obtain morphological variables that characterize the intraspherulitic morphology. These morphological variables are relatively constant during crystallization and are also independent of melt phase separation. On the other hand, the ultimate crystallinity and the crystallization rate depend on the extent of melt phase separation.
Curriculum development for digital libraries

The Virginia Tech Department of Computer Science (VT CS) and the University of North Carolina at Chapel Hill School of Information and Library Science (UNC SILS) have launched a curriculum development project in the area of digital libraries. Educational resources will be developed based on the ACM/IEEE-CS Computing Curriculum 2001. Lesson plans and modules will be developed in a variety of areas (that cover the topics of papers and conference sessions in the field), evaluated by experts in those areas, and then pilot tested in CS and LIS courses. An analysis of papers on digital library-related topics from several corpora was performed, to identify the areas in which more and less work has already been performed on these topics; this analysis will guide the initial stages of this curriculum development.
Real-time iris tracking with a smart camera

This paper presents a real-time iris detection procedure for gray intensity images. Typical applications for iris detection utilize template and feature based methods. These methods are generally time and memory intensive and not applicable for all practical real-time embedded realizations. Here, we propose a method that utilizes a simple algorithm that is time-efficient with high detection and low error rates that is implemented in a smart camera. The system used for this research involves a National Instruments smart camera with LabVIEW Real-Time Module. First, the images are analyzed to determine the region of interest (face). The iris location is determined by applying a convolution-based algorithm on the edge image and then using the Hough Transform. The edge-based less complex and less computationally expensive algorithm results in an efficient analysis method. The extracted iris location information is stored in the camera's image buffer, and used to model one specific eye pattern. The location of the iris thus determined is used as a reference to reduce the search region for the iris in the subsequent images. The iris detection algorithm has been applied at different frame rates. The results demonstrate the speed of this algorithm allows the tracking of the iris when the eyes or the subject is moving in front of the camera at reasonable speeds and with limited occlusions.
Photometric Redshifts and Photometry Errors

We examine the impact of non-Gaussian photometry errors on photometric redshift performance. We find that they greatly increase the scatter, but this can be mitigated to some extent by incorporating the correct noise model into the photometric redshift estimation process. However, the remaining scatter is still equivalent to that of a much shallower survey with Gaussian photometry errors. We also estimate the impact of non-Gaussian errors on the spectroscopic sample size required to verify the photometric redshift rms scatter to a given precision. Even with Gaussian photometry errors, photometric redshift errors are sufficiently non-Gaussian to require an order of magnitude larger sample than simple Gaussian statistics would indicate. The requirements increase from this baseline if non-Gaussian photometry errors are included. Again the impact can be mitigated by incorporating the correct noise model, but only to the equivalent of a survey with much larger Gaussian photometry errors. However, these requirements may well be overestimates because they are based on a need to know the rms, which is particularly sensitive to tails. Other parameterizations of the distribution may require smaller samples.
A Study of Differential Rotation on II Pegasi via Photometric Starspot Imaging

We present the results of a study of differential rotation on the K2 IV primary of the RS CVn binary II Pegasi (HD 224085) performed by inverting light curves to produce images of the dark starspots on its surface. The data were obtained in the standard Johnson B and V filter passbands via the Tennessee State University T3 0.4 m Automated Photometric Telescope from JD 2447115.8086-2455222.6238 (1987 November 16-2010 January 26). The observations were subdivided into 79 data sets consisting of pairs of B and V light curves, which were then inverted using a constrained nonlinear inversion algorithm that makes no a priori assumptions regarding the number of spots or their shapes. The resulting surface images were then assigned to 24 groups corresponding to time intervals over which we could observe the evolution of a given group of spots (except for three groups consisting of single data sets). Of these 24 groups, six showed convincing evidence of differential rotation over time intervals of several months. For the others, the spot configuration was such that differential rotation was neither exhibited nor contraindicated. The differential rotation we infer is in the same sense as that on the Sun: lower latitudes have shortermore » rotation periods. From plots of the range in longitude spanned by the spotted regions versus time, we obtain estimates of the differential rotation coefficient k defined as in earlier work by Henry et al. and show that our results for its value are consistent with the value obtained therein.« less
A class of logarithmic integrals

We present a systematic study of integrals of the form $$I_{Q}=\int_{0}^{1}Q(x)\log\log\frac{1}{x}dx,$$ where Q is a rational function.
THE LITHIUM-ROTATION CORRELATION IN THE PLEIADES REVISITED

The dispersion in lithium abundance at fixed effective temperature in young cool stars like the Pleiades has proved a difficult challenge for stellar evolution theory. We propose that Li abundances relative to a mean temperature trend, rather than the absolute abundances, should be used to analyze the spread in abundance. We present evidence that the dispersion in Li equivalent widths at fixed color in cool single Pleiades stars is at least partially caused by stellar atmosphere effects (most likely departures from ionization predictions of model photospheres) rather than being completely explained by genuine abundance differences. We find that effective temperature estimates from different colors yield systematically different values for active stars. There is also a strong correlation between stellar activity and Li excess, but not a one-to-one mapping between unprojected stellar rotation (from photometric periods) and Li excess. Thus, it is unlikely that rotation is the main cause for the dispersion in the Li abundances. Finally, there is a significant correlation between detrended Li excess and potassium excess but not calcium—perhaps supporting incomplete radiative transfer calculations (and overionization effects in particular) as an important source of the Li scatter. Other mechanisms, such as very small metallicity variations and magnetic fields, which influence pre–main-sequence Li burning may also play a role. Finally, we find no statistical evidence for a decrease in dispersion in the coolest Pleiades stars, contrary to some previous work.
EMP Simulators for Various Types of Nuclear EMP Environments: An Interim Categorization

Nuclear EMP environments have various forms depending on the location of the nuclear detonation and the location of the system exposed to the EMP environment. One can simulate these environments with various degrees of completeness on such systems. A simulator produces an EMP environment on a system of interest in a manner which can be related to the type of nuclear weapon detonation being simulated. There are many types of EMP simulators, some of which have been realized in one or more existing EMP simulators. Some types of EMP simulators only exist conceptually at the present time. This note discusses the basic types or categories of EMP simulators. Such categories are based on the electromagnetic geometry of the simulator structure and electrical sources, including the location of the system under test and other nearby materials significantly influencing the electromagnetic fields. The various types of simulators are suitable for simulating different types of nuclear EMP environments. A particular type of EMP environment can be simulated with different degrees of completeness depending on the type of simulator used. In this note we only consider nonnuclear types of ernegy sources, and in some cases high energy photon and electron sources. The EMP simulators considered range from ones which illuminate entire systems, down to ones which drive individual penetrations into systems. Not considered here are techniques for testing individual components or "black boxes" or driving the system at some intermediate point along an internal cuppling path.
The adrenarche: prolactin, gonadotropins, adrenal androgens, and cortisol.

In order to study the adrenarche, serum concentrations of PRL, FSH, LH, androstenedione, 11β-hydroxyandrostenedione (11βA), dehydroepiandrosterone, dehydroepiandrosterone sulfate, and cortisol were quantified in 106 children from 2–12 years of age and in adults. PRL and 11βA have not previously been reported in a large group of prepubertal children with respect to age. PRL, cortisol, and 11βA showed no significant changes during these years. Androstenedione was present in relatively high concentrations at the youngest ages and increased gradually, whereas FSH and LH rose peripubertally at ages 11 and 12. In contrast, dehydroepiandrosterone and its sulfate showed aprogressive increase with age in boys and a 2-phase increase in girls, with the greatest relative change in the dehydroepiandrosterone sulfate concentration occurring between ages 2 and 5 in girls. These data indicate that significant changes in adrenal androgen secretion occur well before the gonadal changes of puberty in both sexes. The Δ4stero...
Linear Stability Analysis of Nose Bluntness Effects on Hypersonic Boundary Layer Transition

conduct a linear stability analysis on Stetson andRushton’s Mach 5.5experiments in which the reversalis observed. Three cones with nose radiiof 0.156, 0.5,and 1.5 in.,covering both the small andlarge bluntness regions, are used to study the effect of nose bluntness on stability and transition. It is found that, if only the second-mode instabilities are considered, the onset of instability is always delayed as the nose bluntness increases. The linear stability theory calculations show no reversal on the growth of the second-mode instability.
Combinatorial Interpretation of General Eulerian Numbers

Since the 1950s, mathematicians have successfully interpreted the traditional Eulerian numbers and -Eulerian numbers combinatorially. In this paper, the authors give a combinatorial interpretation to the general Eulerian numbers defined on general arithmetic progressions .
Design and Control of the IBM Power 775 Supercomputer Water Conditioning Unit

In 2011 IBM announced the Power 775 Supercomputing node/system which, for the time, was a significant increase in computing performance and energy efficiency. The system was designed from the start with water cooling in mind. The result: a system with greater than 95% of its heat load conducted directly to water and a system that, together with a rear door heat exchanger, removes 100% of its heat load to water with no requirement for room air conditioning. In addition to direct water cooling the processor, the memory, power conversion, and I/O electronics also conduct their heat directly to water. Also included within the framework of the system is a disk storage unit (i.e. disc enclosure) containing an interboard air-to-water heat exchanger.The heart of the water cooling system is the Water Conditioning Unit (WCU). The WCU circulates system water at a controlled temperature and flow rate while also transferring the electronics heat load to the data center facility (building chilled water) system. The brain for this system is the motor drive and control assembly (MDA-WCU). In addition to the pump motor drive function, the MDA-WCU contains the control circuitry and associated firmware that maintains system water at a prescribed temperature above the room dew point irrespective of system and or facilities thermal/flow transients. It is also capable of error detection and fault isolation that, together with higher level system firmware, facilitates serviceability and availability. The paper will present the WCU and MDA-WCU design with an emphasis on the control methodologies and algorithms.Copyright © 2013 by ASME
On simultaneous approximation and interpolation which preserves the norm

Motivated by Wolibner's theorem, we consider the following more general problem. Let M bes. dense subspace of the real normed linear space X, and let {x*, • • • , #*} be a finite subset of the dual space X*. The triple (X, M, {xf, • • • , x*}) will be said to have property SAIN (simultaneous approximation and interpolation which is norm-preserving) provided that the following condition is satisfied: For each x £ X and each €>0 there exists a y£ilf such that ||#—;y|| <e, x*(y)=x*(x) (i = l, • • • , w), and \\y\\= \\x\\. In this note we shall outline some of the main results we have obtained regarding property SAIN. Detailed proofs and related matter will appear elsewhere.
Tobyhanna army depot Automated Test System modernization

During the last four decades the number of Automated Test Systems (ATS) has experienced tremendous growth at Tobyhanna Army Depot (TYAD). This is characterized in the proliferation through Base Realignment and Closure acquisition and in-house development of a wide variety of general and special-purpose ATS - to date, there are 94 unique ATS and a total of 230 ATS. With advancing technology and increasingly complex electronic systems, unique ATS has become a problem of maintenance test strategies at the depot; given the high costs of modernizing or replacing ATS and its potential effect on meeting mission success requirements. The aging testers at TYAD are becoming increasingly out-of-date and more difficult to support. When the testers do not work properly, maintenance can suffer and mission readiness can be adversely affected. This will analyze the problem and present a plan for modernization of ATS at TYAD that satisfies Army Regulation, AR750-43, and DoD ATS acquisition policy.
Synthesis of an optically active octahydro-2H-pyrido[1,2-a]pyrazine based CNS agent

Abstract A synthesis of an optically active octahydro-2H-pyrido[1,2-a]pyrazine is presented. The key sequence involved the equilibration of an optically active cis-aldehyde to give the thermodynamic trans-aldehyde that was trapped by nitromethane anion.
Use of fluorous silica gel to separate fluorous thiol quenching derivatives in solution-phase parallel synthesis

A general fluorous thiol quenching method is introduced. Excess α-bromoketones or benzyl bromides in parallel N-alkylation reactions are quenched with a fluorous thiol (C6F13CH2CH2SH). The resulting fluorous derivatives can be separated from the reaction mixture by a solid phase extraction on fluorous silica gel.
On helping by robust oracle machines

Abstract The concept of helping by robust oracle Turing machines, introduced recently by Schoning, is extended to the notion of ‘one-sided helping’ and its relations to the structural properties of NP sets are investigated. Various results on who can help whom have been obtained on sets in BPP, in R, in UP and sparse sets. Sets which do not help any set are studied and two types of sets defined by structural properties are demonstrated to help no sets except those in P. Sest which help themselves are also studied and are shown to be related to self-reducible sets. Several previously known structural results on NP sets are reproved from the point of view of helping.
How the Performance of a Superconducting Magnet Is Affected by the Connection Between a Small Cooler and the Magnet

As low temperature cryocoolers become more frequently used to cool superconducting magnets, it becomes increasingly apparent that the connection between the cooler and the magnet has an effect on the design and performance of the magnet. In general, the use of small coolers can be considered in two different temperature ranges; 1) from 3.8 to 4.8 K for magnet fabricated with LTS conductor and 2) from 18 to 35 K for magnets fabricated using HTS conductor. In general, both temperature ranges call for the use of a two-stage cooler. The best method for connecting a cooler to the magnet depends on a number of factors. The factors include: 1) whether the cooler must be used to cool down the magnet from room temperature, 2) whether the magnet must have one or more reservoirs of liquid cryogen to keep the magnet cold during a loss of cooling, and 3) constraints on the distance from the cooler cold heads and the magnet and its shield. Two methods for connecting low temperature coolers to superconducting magnets have been studied. The first method uses a cold strap to connect the cold heads directly to the loads. This method is commonly used for cryogen-free magnets. The second method uses a thermal siphon and liquid cryogens to make the connection between the load being cooled and the cold head. The two methods of transferring heat from the magnet to the cooler low temperature cold head are compared for the two temperature ranges given above
Construction of the Keck Observatory

The W.M. Keck Observatory and its Ten-Meter Telescope are nearing completion at the summit of Mauna Kea. The 10-m diameter primary mirror has a 17.5-m focal length and is composed of 36 hexagonal segments. There will be seven Ritchey-Chretien f/15 foci: two of them at Nasmyth foci, one at Cassegrain focus, and four at bent Cassegrain foci on the elevation ring. There will also be an f/25 IR focal plane at the intersection of the optical and elevation axes, whose focus will be chopped by a beryllium secondary mirror. Image quality with a FWHM of the order of about 0.25 arcsec, and an 80-percent enclosed energy diameter of about 0.40 arcsec, are anticipated.
The economics of biomass collection and transportation and its supply to Indiana cellulosic and electric utility facilities

With cellulosic energy production from biomass becoming popular in renewable energy research, agricultural producers may be called upon to plant and collect corn stover or harvest switchgrass to supply feedstocks to nearby facilities. Determining the production and transportation cost to the producer of corn stover or switchgrass and the amount available within a given distance from the plant will result in a per metric ton cost the plant will need to pay producers in order to receive sufficient quantities of biomass. This research computes up-to-date biomass production costs using recent prices for all important cost components including seed, fertilizer, herbicide, mowing/shredding, raking, baling, storage, handling, and transportation. The cost estimates also include nutrient replacement for corn stover. The total per metric ton cost is a combination of these cost components depending on whether equipment is owned or custom hired, what baling options are used, the size of the farm, and the transport distance. Total costs per dry metric ton for biomass with a transportation distance of 60 km ranges between $63 and $75 for corn stover and $80 and $96 for switchgrass. Using the county quantity data and this cost information, we then estimate biomass supply curves for three Indiana coal-fired electric utilities. This supply framework can be applied to plants of any size, location, and type, such as future cellulosic ethanol plants. Finally, greenhouse gas emissions reductions are estimated from using biomass instead of coal for part of the utility energy and also the carbon tax required to make the biomass and coal costs equivalent. Depending on the assumed CO2 price, the use of biomass instead of coal is found to decrease overall costs in most cases.
Feasible proofs and computations: partnership and fusion

A computation or a proof is called feasible if it obeys prescribed bounds on the resources consumed during its execution. It turns out that when restricted to this world of feasibility, proofs and computations become extremely tightly interrelated, sometimes even indistinguishable. Moreover, many of these rich relations, underlying concepts, techniques etc. look very different from their "'classical" counterparts, or simply do not have any. This paper is intended as a very informal and popular (highly biased as well) attempt to illustrate these fascinating connections by several related developments in the modern complexity theory.
Effect of Sun's magnetic field polarity on interplanetary magnetic field Bz

[1] The results of a statistical study of interplanetary magnetic field IMF Bz are presented for two minima of solar activity for the periods of 1985–1987 and 1995–1997, related to negative and positive polarity of the Sun's magnetic field, respectively, for low sunspot numbers and relatively quiet solar wind conditions. The negative and positive polarities correspond to conditions when the Sun's magnetic field in the northern hemisphere is directed toward and outward the Sun, respectively. We found that IMF Bz is dependent on the magnitude of IMF horizontal (Bx) component, IMF orientation, and Sun's magnetic field polarity. The correlation between IMF Bz and ∣Bx∣ is positive for positive polarity and negative for negative polarity. Another interesting result is the fact that positive and negative IMF Bz tend to occur predominantly during IMF orientations significantly different from the Parker spiral at the angle ϕ* ≈ ±60° where ϕ* is the acute angle measured counterclockwise from Parker spiral direction to IMF vector in the horizontal plane. The effect of Sun's magnetic field polarity is especially evident for large IMF ∣Bx∣ > 4 nT. In this case, IMF Bz are predominantly negative for negative polarity and positive for positive polarity, and the difference between average IMF Bz for positive and negative Sun's magnetic field polarities is ∼2 nT. Correlation coefficient characterizing the dependence of IMF Bz on Sun's magnetic field polarity is about 0.5 and increases with increasing IMF ∣Bx∣. The observed features of IMF Bz may be caused by decreasing solar wind speed near the HCS. As a result, portions of disturbed magnetic field lines slow down while approaching the HCS. This leads to the rotation of IMF vector in the vertical and horizontal planes. The observed dependences of IMF Bz on IMF ∣Bx∣, IMF orientation, and Sun's magnetic field polarity are qualitatively consistent with this hypothesis.
The DEEP2 galaxy redshift survey: Redshift identification of single-line emission galaxies

We present two methods for determining spectroscopic redshifts of galaxies in the DEEP2 survey which display only one identifiable feature, an emission line, in the observed spectrum ("single-line galaxies"). First, we assume each single line is one of the four brightest lines accessible to DEEP2: Hα, [O III] λ5007, Hβ, or [O II] λ3727. Then, we supplement spectral information with BRI photometry. The first method, parameter-space proximity (PSP), calculates the distance of a single-line galaxy to galaxies of known redshift in (B - R), (R - I), R, λobserved parameter space. The second method is an artificial neural network (ANN). Prior information, such as allowable line widths and ratios, rules out one or more of the four lines for some galaxies in both methods. Based on analyses of evaluation sets, both methods are nearly perfect at identifying blended [O II] doublets. Of the lines identified as Hα in the PSP and ANN methods, 91.4% and 94.2%, respectively, are accurate. Although the methods are not this accurate at discriminating between [O III] and Hβ, they can identify a single line as one of the two, and the ANN method in particular unambiguously identifies many [O III] lines. From a sample of 640 single-line spectra, the methods determine the identities of 401 (62.7%) and 472 (73.8%) single lines, respectively, at accuracies similar to those found in the evaluation sets.
The political economy of Central America since 1920

List of figures List of tables Preface List of acronyms Table of official exchange rate parities to US dollar Map: Central America 1. A century of independence: foundations of export-led growth 2. Central America in the 1920s: reform and consolidation 3. The 1929 depression 4. Economic recovery and political reaction in the 1930s 5. Central America and the Second World War 6. Post-war economic recovery 7. The struggle for democracy, the Cold War and the Labour movement in the first post-war decade 8. The foundations of modern export-led growth, 1954-60 9. The illusion of a golden age, 1960-70 10. External shocks and the challenge to the social order, 1970-9 11. The descent into regional crisis 12. Conclusions Methodological appendix Statistical appendix Notes Bibliography Index.
On the Two Components of Turbulent Mixing Noise from Supersonic Jets

It is argued that because of the lack of intrinsic length and time scales in the core part of the jet flow, the radiated noise spectrum of a high-speed jet should exhibit similarity. A careful analysis of all the axisymmetric supersonic jet noise spectra in the data-bank of the Jet Noise Laboratory of the NASA Langley Research Center has been carried out. Two similarity spectra, one for the noise from the large turbulence structures/instability waves of the jet flow, the other for the noise from the fine-scale turbulence, are identified. The two similarity spectra appear to be universal spectra for axisymmetric jets. They fit all the measured data including those from subsonic jets. Experimental evidence are presented showing that regardless of whether a jet is supersonic or subsonic the noise characteristics and generation mechanisms are the same. There is large turbulence structures/instability waves noise from subsonic jets. This noise component can be seen prominently inside the cone of silence of the fine-scale turbulence noise near the jet axis. For imperfectly expanded supersonic jets, a shock cell structure is formed inside the jet plume. Measured spectra are provided to demonstrate that the presence of a shock cell structure has little effect on the radiated turbulent mixing noise. The shape of the noise spectrum as well as the noise intensity remain practically the same as those of a fully expanded jet. However, for jets undergoing strong screeching, there is broadband noise amplification for both turbulent mixing noise components. It is discovered through a pilot study of the noise spectrum of rectangular and elliptic supersonic jets that the turbulent mixing noise of these jets is also made up of the same two noise components found in axisymmetric jets. The spectrum of each individual noise component also fits the corresponding similarity spectrum of axisymmetric jets.
Non-Commutative Martingale Transforms

Abstract We prove that non-commutative martingale transforms are of weak type (1,1). More precisely, there is an absolute constant C such that if M is a semi-finite von Neumann algebra and ( M n ) n =1 ∞ is an increasing filtration of von Neumann subalgebras of M then for any non-commutative martingale x =( x n ) n =1 ∞ in L 1 ( M ), adapted to ( M n ) n =1 ∞ , and any sequence of signs (e n ) n =1 ∞ , ∥e 1 x 1 + ∑ n=2 N e n (x n −x n−1 )∥ 1,∞ ⩽C∥x N ∥ 1 for every N ⩾2. This generalizes a result of Burkholder from classical martingale theory to non-commutative setting and answers positively a question of Pisier and Xu. As applications, we get the optimal order of the unconditional Martingale differences (UMD)-constants of the Schatten class S p when p→∞. Similarly, we prove that the UMD-constant of the finite-dimensional Schatten class S n 1 is of order log( n +1). We also discuss the Pisier–Xu non-commutative Burkholder–Gundy inequalities.
Salicylate Accumulation Kinetics in Man

Abstract The plateau level of salicylate in the body attained by repetitive administration of fixed doses of aspirin or sodium salicylate at constant intervals increases more than proportionately with increasing dosages. The time required to attain the plateau increases with increasing dose. These unusual accumulation characteristics account for the pronounced effects of relatively small changes in maintenance dosage on salicylate concentrations in body fluids and on the pharmacologic effects of this drug. It is thus important to make upward adjustments of dosage cautiously, allowing sufficient time for body levels to reach the new steady state before the dosage is increased still further.
A family of N = 2 gauge theories with exact S-duality

We study an infinite family of N = 2 Sp(2n) gauge theories that naturally arise from the D3-brane probe dynamics in F-theory. The matter sector consists of four fundamental and one antisymmetric tensor hypermultiplets. We propose that, in the limit of vanishing bare masses, the theory has exact SO(8) ⋉ SL(2, Z) duality. We examine the semiclassical BPS spectrum in the Coulomb phase by quantizing various monopole moduli space dynamics, and show that it is indeed consistent with the exact S-duality.
Adaptive hard handoff algorithms

The design of hard handoff algorithms based on optimizing the tradeoff between link quality and rate of handoffs is considered. For handoff algorithms based on this criterion, adaptation is precisely defined in terms of remaining on a locus of desirable operating points as system parameters (such as mobile velocity) change. A rule based on a linear cost criterion is used to select desirable operating points. For this rule, it is shown that the optimal handoff algorithm, which is impractical, is easily adapted by fixing a single tradeoff parameter at an appropriate value. The same adaptation property is shown to hold for an easily implementable approximation to the optimal algorithm, the locally optimal (LO) handoff algorithm. This is in contrast to the poor adaptation of hysteresis based approaches which require lookup tables for adaptation. Practical estimators for all relevant system parameters based on a short window of pilot signal strength measurements are also discussed. It is shown that the LO algorithm adapts well when these simple estimators are used. A hysteresis-threshold approximation to the adaptive LO algorithm is also developed.
Measuring invisible particle masses using a single short decay chain

We consider the mass measurement at hadron colliders for a decay chain of two steps, which ends with a missing particle. Such a topology appears as a subprocess of signal events of many new physics models which contain a dark matter candidate. From the two visible particles coming from the decay chain, only one invariant mass combination can be formed and hence it is naively expected that the masses of the three invisible particles in the decay chain cannot be determined from a single end point of the invariant mass distribution. We show that the event distribution in the log(E 1T /E 2T ) vs. invariant mass-squared plane, where E 1T , E 2T are the transverse energies of the two visible particles, contains the information of all three invisible particle masses and allows them to be extracted individually. The experimental smearing and combinatorial issues pose challenges to the mass measurements. However, in many cases the three invisible particle masses in the decay chain can be determined with reasonable accuracies.