cssi/SciSciGPT-SciSciNet huggingface dataset:
Is ENSO a cycle or a series of events

[1] After early ideas that saw El Ninos as isolated events, the advent of coupled models brought the conception of ENSO as a cycle in which each phase led to the next in a self-sustained oscillation. Twenty-two years of observations that represent the El Nino and La Nina peaks (east Pacific SST) and the memory of the system (zonal mean warm water volume) suggest a distinct break in the cycle, in which the coupled system is able to remain in a weak La Nina state for up to two years, so that memory of previous influences would be lost. Similarly, while the amplitude of anomalies persists from the onset of a warm event through its termination, there is no such persistence across the La Nina break. These observations suggest that El Ninos are in fact event-like disturbances to a stable basic state, requiring an initiating impulse not contained in the dynamics of the cycle itself.
Risk‐Off Episodes and Swiss Franc Appreciation: The Role of Capital Flows

During episodes of increased global risk aversion, or risk-off episodes, safe haven currencies such as the Swiss franc tend to appreciate. The immediate impact of a risk-off shock is an increase in net private inflows to Switzerland, mostly driven by a reduction in Swiss residents’ net purchases of foreign debt securities and reduced foreign exposure by Swiss banks. Given that the bulk of capital movements related to risk-off episodes is driven by decisions of Swiss residents, capital flow management policies that discriminate based on the residency of the investor (capital controls) are not likely to be effective at reducing the impact of risk-off episodes. However, prudential policies that limit leveraging or foreign exposure by Swiss banks may diminish the volatility of capital flows during risk-off episodes.
Improving explicit congestion notification with the mark-front strategy

Delivering congestion signals is essential to the performance of networks. Current TCP/IP networks use packet losses to signal congestion. Packet losses not only reduces TCP performance, but also adds large delay. Explicit Congestion Notification (ECN) delivers a faster indication of congestion and has better performance. However, current ECN implementations mark the packet from the tail of the queue. In this paper, we propose the mark-front strategy to send an even faster congestion signal. We show that mark-front strategy reduces buffer size requirement, improves link efficiency and provides better fairness among users. Simulation results that verify our analysis are also presented.
The effects of anions on hydrogen electrosorption on platinum single-crystal electrodes

Abstract Hydrogen adsorption on the low index planes of single crystal Pt has been investigated using a technique which involves annealing in a H2 flame and transfer through the air into the electrolyte. The results are compared with those obtained with a special vacuum transfer system. The effects of adsorbed anions such as NO−3 and Cl− are very pronounced. This paper discusses several of the factors controlling hydrogen adsorption on Pt and particularly anion effects.
Reductive C-alkylation of barbituric acid derivatives with carbonyl compounds in the presence of platinum and palladium catalysts ☆

Abstract Effective synthetic procedures for the preparation of mono- and di-C-alkylated barbituric acid derivatives through palladium and platinum catalytic hydrogenation of solutions of barbituric acids (unsubstituted, N-mono, and N,N′-disubstituted barbituric acids) and carbonyl compounds (aliphatic and aromatic aldehydes and ketones).
The nature of sociological knowledge

This collection of papers materialized in response to the American Sociological Association’s call for centennial plenary sessions in 2004 as it prepared for the 2005 annual meeting in Philadelphia. Three of the nearly two-dozen centennial plenary sessions selected for the conference proceedings focused on the subject of sociological knowledge. One of these plenary sessions was organized by me; the other two, originally intended to be one session but divided in order to accommodate the large number of proposed presenters, was organized by Barbara Schneider. Shortly after the sessions were confirmed, I contacted Barbara to determine her interest in publishing some of the presentations as a collection that offered multiple perspectives on the nature of sociological knowledge. Based on the initial interest expressed by both Barbara and the presenters, I contacted Larry Nichols to determine if he might have an interest in publishing a special issue of The American Sociologist on this topic. Upon his consent, work proceeded forward on this special issue.
Series representation of the Riemann zeta function and other results: Complements to a paper of Crandall

We supplement a very recent paper of R. Crandall concerned with the multiprecision computation of several important special functions and numbers. We show an alternative series representation for the Riemann and Hurwitz zeta functions providing analytic continuation through out the whole complex plane. Additionally we demonstrate some series representations for the initial Stieltjes constants appearing in the Laurent expansion of the Hurwitz zeta function. A particular point of elaboration in these developments is the hypergeometric form and its equivalents for certain derivatives of the incomplete Gamma function. Finally, we evaluate certain integrals including $\int_{\tiny{Re} s=c} {{\zeta(s)} \over s} ds$ and $\int_{\tiny{Re} s=c} {{\eta(s)} \over s} ds$, with $\zeta$ the Riemann zeta function and $\eta$ its alternating form.
Microwave imaging reflectometry for the visualization of turbulence in tokamaks

Understanding the mechanism of anomalous transport in magnetically confined plasmas requires the use of sophisticated diagnostic tools for the measurement of turbulent fluctuations. The article describes the results of an extensive numerical study of microwave reflectometry in tokamaks showing that the two dimensional structure of plasma fluctuations near the cut-off can be obtained from the phase of reflected waves. This requires the latter to be collected by an optical system making an image of the reflecting layer onto an array of microwave receivers, and the amplitude of fluctuations to be below a threshold that is set by the spectrum of poloidal wavenumbers. The conceptual design of an experimental scheme for the global visualization of turbulent fluctuations in tokamaks is described.
Iterative elimination of weakly dominated strategies in binary voting agendas with sequential voting

This paper describes the correspondences between the results given by backward induction (BI) and iterative elimination of weakly dominated strategies (IEWDS) in binary voting agendas with sequential voting. When the voters have strict preferences over all candidates, the strategies that survive IEWDS all select the unique candidate selected by the BI strategy profiles. But if some voters are indifferent, this result no longer holds. However, when there are only two candidates, it is possible to demonstrate strong relationships between the results given by BI and IEWDS, even when some voters have indifferences.
Collecting cyclic distributed garbage by controlled migration

Distributed systems with a large number of nodes use internode reference counting for timely and fault-tolerant garbage collection. However, this fails to collect cyclic garbage distributed across nodes. One fix is to migrate all objects on a garbage cycle to a single node, where they can be collected by the tracing-based local collector. Existing proposals based on this technique have practical problems due to unnecessary migration of objects. We propose a scheme that avoids migration of live objects, batches objects to avoid a cascade of migration messages, and short-cuts the migration path to avoid multiple migrations. We use simple estimates to detect objects that are highly likely to be cyclic garbage and to select a node to which such objects are migrated. The scheme collects all distributed cyclic garbage, has low overhead, and preserves the decentralized and fault-tolerant nature of distributed reference counting and migration.
Nanospring formation—unexpected catalyst mediated growth

Nanosprings are a new form of nanowires that have potential applications in nanoelectronics, nanomechanics, and nanoelectromechanical systems. In this review we will examine the growth mechanism of these novel nanostructures. The synthesis of nanowires by the vapour–liquid–solid growth mechanism, first proposed by Wagner and Ellis, will be explored and then extended to the development of a model to explain the formation of nanosprings.
Anomalous Reorganization Free Energies in Optical Electron Transfer in Solution.

Autoionization bands are observed in the photoelectron emission spectroscopy of aqueous solutions of cyanometalate complexes (Mn, Fe, W, Mo), anions (NO3, CIO−4 and cations (Ag+ TI+. Reorganization free energies for autoionization bands are anomalously low in absolute value (by≈1 eV) in comparison with direct transitions to the continuum. Interpretation is based on potential energy profiles and model calculations for the reorganization free energy.
Quantum Mechanics on Hilbert Manifolds: The Principle of Functional Relativity

Quantum mechanics is formulated as a geometric theory on a Hilbert manifold. Images of charts on the manifold are allowed to belong to arbitrary Hilbert spaces of functions including spaces of generalized functions. Tensor equations in this setting, also called functional tensor equations, describe families of functional equations on various Hilbert spaces of functions. The principle of functional relativity is introduced which states that quantum theory (QT) is indeed a functional tensor theory, i.e., it can be described by functional tensor equations. The main equations of QT are shown to be compatible with the principle of functional relativity. By accepting the principle as a hypothesis, we then explain the origin of physical dimensions, provide a geometric interpretation of Planck’s constant, and find a simple model of the two-slit experiment and the process of measurement.
Entropy based nearest neighbor search in high dimensions

In this paper we study the problem of finding the approximate nearest neighbor of a query point in the high dimensional space, focusing on the Euclidean space. The earlier approaches use locality-preserving hash functions (that tend to map nearby points to the same value) to construct several hash tables to ensure that the query point hashes to the same bucket as its nearest neighbor in at least one table. Our approach is different - we use one (or a few) hash table and hash several randomly chosen points in the neighborhood of the query point showing that at least one of them will hash to the bucket containing its nearest neighbor. We show that the number of randomly chosen points in the neighborhood of the query point q required depends on the entropy of the hash value h(p) of a random point p at the same distance from q at its nearest neighbor, given q and the locality preserving hash function h chosen randomly from the hash family. Precisely, we show that if the entropy I(h(p)|q, h) = M and g is a bound on the probability that two far-off points will hash to the same bucket, then we can find the approximate nearest neighbor in O(np) time and near linear O(n) space where p = M/log(1/g). Alternatively we can build a data structure of size O(n1/(1-p)) to answer queries in O(d) time. By applying this analysis to the locality preserving hash functions in [17, 21, 6] and adjusting the parameters we show that the c nearest neighbor can be computed in time O(np) and near linear space where p a 2.06/c as c becomes large.
A Two-dimensional, Self-consistent Model of Galactic Cosmic Rays in the Heliosphere

We present initial results from our new two-dimensional (radius and latitude), self-consistent model of galactic cosmic rays in the heliosphere. We focus on the latitudinal variations in the solar wind flow caused by the energetic particles. Among other things, our results show that the cosmic rays significantly modify the latitudinal structure of the solar wind flow downstream of the termination shock. Specifically, for A > 0 (corresponding to the present solar minimum) the wind beyond the shock is driven toward the equator, resulting in a faster wind flow near the current sheet, while for A < 0 the effect is reversed and the wind turns toward the pole, with a faster flow at high latitudes. We attribute this effect to the latitudinal gradients in the cosmic-ray pressure, caused by drifts, that squeeze the flow toward the ecliptic plane or the pole.
Information optics concepts applied to image formation in highly scattering media

We describe a number of methods for imaging into and through highly scattering media, all based in optical imaging processing methods. We describe methods that describe image formation in scattering media in new ways that complement transport theory and other traditional ways.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
On Asymptotic Dimension of Groups Acting on Trees

We prove the following. THEOREM. Let π be the fundamental group of a finite graph of groups with finitely generated vertex groups G v having asdim G v ≤n for all vertices v. Then asdim π≤n+1. This gives the best possible estimate for the asymptotic dimension of an HNN extension and the amalgamated product.
Measuring and monitoring soil organic carbon stocks in agricultural lands for climate mitigation

Policies that encourage greenhouse-gas emitters to mitigate emissions through terrestrial carbon (C) offsets – C sequestration in soils or biomass – will promote practices that reduce erosion and build soil fertility, while fostering adaptation to climate change, agricultural development, and rehabilitation of degraded soils. However, none of these benefits will be possible until changes in C stocks can be documented accurately and cost-effectively. This is particularly challenging when dealing with changes in soil organic C (SOC) stocks. Precise methods for measuring C in soil samples are well established, but spatial variability in the factors that determine SOC stocks makes it difficult to document change. Widespread interest in the benefits of SOC sequestration has brought this issue to the fore in the development of US and international climate policy. Here, we review the challenges to documenting changes in SOC stocks, how policy decisions influence offset documentation requirements, and the benefit...
Isolating Geometry in Weak-Lensing Measurements

Given a foreground galaxy-density field or shear field, its cross-correlation with the shear field from a background population of source galaxies scales with the source redshift in a way that is specific to lensing. Such a source scaling can be exploited to effectively measure geometrical distances as a function of redshift and thereby constrain dark energy properties, free of any assumptions about the galaxy-mass/mass power spectrum (its shape, amplitude, or growth). Such a geometrical method can yield a ~(0.03-0.07)f measurement on the dark energy abundance and equation of state for a photometric redshift accuracy of Δz ~ 0.01-0.05 and a survey with a median redshift of ~1. While these constraints are weaker than conventional weak-lensing methods, they provide an important consistency check, because the geometrical method carries less theoretical baggage: there is no need to assume any structure formation model (e.g., CDM). The geometrical method is at the most conservative end of a whole spectrum of methods that obtain smaller error bars by making more restrictive assumptions—we discuss some examples. Our geometrical approach differs from previous investigations along similar lines in three respects. First, the source scaling we propose to use is less demanding on the photometric redshift accuracy. Second, the scaling works for both galaxy-shear and shear-shear correlations. Third, we find that previous studies underestimate the statistical errors associated with similar geometrical methods, the origin of which is discussed.
Real-time presentation of reduced wind-tunnel data

The effective use of wind-tunnel testing in determining aerodynamic properties of a body is very much dependent upon the reliability and speed with which wind-tunnel data can be reduced. The ability to provide reduced aerodynamic coefficients in real time, or on-line, greatly increases the operating efficiency of the wind tunnels and thereby reduces expensive wind-tunnel time required for each test. This paper describes a system for presenting reduced wind-tunnel data in real time for the two wind tunnels at the Jet Propulsion Laboratory (JPL).
1‐(Mercaptomethyl)benzotriazole: Preparation, reactivity and synthetic utility

A convenient synthesis is reported for 1-(mercaptomethyl)benzotriazole (89%) and its reactivity is examined.
Analysis of Error in Pavement Ground Truth Indicators for Evaluating the Accuracy of Automated Image Collection and Analysis System

The main purpose of this paper is to present the Automated Image Collection System (AICS) and Manual Image Analysis System (MIAS) as “ground-truth” for evaluating Automated Image Collection System (AICS) and Automated Image Analysis System (AIAS) for highway asset management. The proposed “ground-truth” is evaluated with respect to its repeatability against a traditional “ground-truth” procedure based on Manual Distress Collection System (MDCS) and Manual Distress Analysis System (MDAS). To capture digital images automatically, a vehicle mounted with a digital video camera was driven on the pavement test section. To determine the repeatability of MIAS, the images were evaluated by three individuals twice per individual. To determine the repeatability of MDCS/MDAS, the same individuals were asked to evaluate the same pavement section in the field twice per individual. Repeatability on three crack types was evaluated for two survey methods and three individuals. Overall, the average relative precisions of AICS/MIAS-based procedure by three individuals were 10, 8, and 19 % for longitudinal, transverse, and block cracks, respectively, whereas those of MDCS/MDAS-based procedure were 43, 45, and 41 % for longitudinal, transverse, and block cracks, respectively. In conclusion, the proposed AICS/MIAS-based “ground-truth” measurements can be considered as more repeatable by human operators than MDCS/MDAS-based “ground-truth” measurements.
An analytical study of the impulsive approximation.

the basis of the Abel-Tauber theorems, that elasticity bounds on effective moduli can be transcribed into bounds on viscoelastic effective relaxation moduli at times zero and infinity, simply by replacement of phase elastic moduli in the bound expressions, by initial and ultimate values of the phase relaxation moduli. Consequently, the bounds on G<x*E* can be used to find bounds on G 23*£(0) and G23*(°°) of a composite cylinder assemblage. If results for intermediate times are needed, the following observation may be of some value. It has been shown4 that a lower bound for GM*E of a fiber reinforced material, with arbitrary fiber shapes, is given by the expression [\/(GfE - GmE)] + [(k mE + 2GmE}vm/2GmE(kE + GmE)] (6.5) It may be shown that (6.5) is always between the bounds for G<x*E of a cylinder assemblage which has been derived in Ref. 2. Furthermore, for v/ very close to zero or very close to unity, these bounds coincide and reduce to (6.5). Therefore, if the bounds for the elastic case are reasonably close, there may be some merit in replacing the phase moduli in (6.5) by TD phase moduli and inverting into the time domain. It may be hoped then that the resulting expression will give Gw*E(t) of a composite cylinder assemblage, approximately. 7. Conclusion The analysis that has been given here may be regarded as a first step in the theoretical prediction of the viscoelastic properties of fiber reinforced materials. The composite
Heteroaromatic taxol analogues : the chemistry and biological activities of 3'-furyl and 3'-pyridyl substituted taxanes

Abstract A series of novel heterocyclic taxol analogues has been synthesized utilizing 2-azetidinones derived from the ester enolate-imine cyclocondensation. 2-Azetidinones possessing stereochemistry complementary to that of taxol's phenylisoserine side chain were synthesized in fair to high enantiomeric purity utilizing the chiral glycolate derived from Oppolzer's chiral auxiliary and the appropriate N-trimethylsilylaldimines. These novel analogues were evaluated in the microtubule assembly assay as well as tested for cytotoxicity against B16 melanoma cells. The 2-furyl analoug e 29 proved to be more active than the parent, taxol.
Complete problems and strong polynomial reducibilities

A set A is m-reducible to a set B if and only if there is a polynomial-time computable function f such that for all x, $x \in A \Leftrightarrow f(x) \in B$. A set C is m-complete for a class S if $C \in S$ and all sets in S are m-reducible to C. One-reducibility and one-completeness can be defined by requiring f to be one–one. Two sets A and B are p-isomorphic if the function f can be taken one-to-one, onto, and polynomially invertible. In this paper it is shown that all the m-complete sets are one–one complete for ${\operatorname{DTIME}}(2^{\mathcal{O}(n)} )$, ${\operatorname{NTIME}}(2^{\mathcal{O}(n)} )$, and the class of recursively enumerable sets. Further, all the sets complete for ${\operatorname{NTIME}}(2^{\mathcal{O}(n)} )$ under 1–L (or two-way DFA) reductions are p-isomorphic. All the m-complete sets for ${\operatorname{DTIME}}(2^{\mathcal{O}(n)} )$ are p-isomorphic if and only if all the m-complete sets for DTIME($2^{{\text{poly}}} $) are p-isomorphic.
Separation of Powers and Appointee Ideology

The traditional view of appointments to executive agencies is that the president has virtual carte blanche in the selection of personnel for his "team." Yet many formal models of appointment suggest that presidents must accommodate the policy preferences of senators when making nominations. Several empirical studies have confirmed that legislative preferences are a significant determinant of the ideology of appointees, but these studies have focused on appointments to the federal judiciary; the research has not addressed appointments to executive agencies. Appointments to executive agencies from 1936 to 1996 are examined, by employing a special sample of appointees to those positions--those who have served in Congress at some point in their careers. For these "bridging" individuals, it is possible to analyze strictly comparable measures of ideology for the appointees, their nominating presidents, and the senators who voted to confirm them. A linear regression analysis provides significant support for the hypothesis that appointee ideology is affected by variation in the ideological tilt in Congress. Copyright 2004, Oxford University Press.
Evidence of the FIP Effect in the Coronae of Late-Type Giants

The stars β Cet, 31 Com, and μ Vel represent the main stages through which late-type giants evolve during their lifetime (the Hertzsprung gap [31 Com], the rapid braking zone [μ Vel], and the core helium burning "clump" phase [β Cet]). An analysis of their high-resolution Chandra X-ray spectra reveals similar coronal characteristics in terms of both temperature structure and element abundances for the more evolved stars (μ Vel and β Cet), with slight differences for the "younger" giant (31 Com). The coronal temperature structure of 31 Com is significantly hotter, showing a clear peak, while β Cet and μ Vel show a plateau. β Cet and μ Vel show evidence for a FIP effect in which coronae are depleted in high-FIP elements relative to their photospheres by a factor of ~2. In contrast, 31 Com is characterized by a lack of FIP effect. In other words, neither depletion nor enhancement relative to stellar photospheric values is found. We conclude that the structural changes during the evolution of late-type giants could be responsible for the observed differences in coronal abundances and temperature structure. In particular, the size of the convection zone coupled with the rotation rate seem obvious choices for playing a key role in determining coronal characteristics.
AN INTEGRATED GPS/IRS DESIGN APPROACH

Development and testing of a prototype GPS receiver housed in a commercial inertial reference system has recently been completed. A flight test program in 1986 demonstrated dynamic performance in maneuvering flight, operation in low signal/noise environments, and operation at zero degree satellite elevation angles with 20–30 m typical accuracies using the Block I GPS satellites. The effects of altitude and clock aiding were also demonstrated. Many of the recognized limitations of an inertial system (including unbounded position error and pilot initialization as well as stand-alone GPS limitations such as poor satellite geometry, dynamic noise and satellite masking) are overcome with this integrated design approach. This paper describes the advantages of GPS/IRS integration as well as a design approach that utilizes them. The paper also summarizes some test results of the prototype GPS receiver.
Choice of technology in outsourcing: an endogenous information structure

Abstract We study a monopsonist-supplier model in which each party has its own technology for production. The supplier may use its own or be required to adopt the buyer's technology. Because the efficiency of each technology is unknown to the other party, the choice of technology determines the informed party. We find that using the buyer's technology reduces not only the supplier's incentive to misrepresent, but sometimes the buyer's as well. As a result, when equally efficient, the buyer's technology is adopted. In cases where each technology has several states of efficiency, the less efficient technology may be assigned in the optimal contract.
Total Synthesis of (−)-Lycoperine A

Lycoperine A was synthesized through a highly convergent route in which a double alkylation of 2,6-dicyano-N-benzylpiperidine with the octahydroquinoline moiety gave the lycoperine skeleton. The octahydroquinoline was prepared by a desymmetrization reaction of 5-methylcyclohexane-1,3-dione. Hydrolysis, reductive amination, and cyclization gave lycoperine A in 13 steps and 3% overall yield. The absolute configuration of lycoperine A was assigned as 6R,6′R,8R,8′R,13S,17R.
Symptomatic age-related macular degeneration in Asian patients.

PURPOSE To characterize retinal and fluorescein angiographic findings of Asian patients with symptoms secondary to age-related macular degeneration (ARMD). METHODS We retrospectively reviewed 453 consecutive medical records corresponding to fluorescein angiograms performed between November 1992 and November 1995 to identify Asian patients with symptomatic ARMD. Presenting visual symptoms, best-corrected Snellen visual acuities, and retinal examination findings were determined from the medical records. Fundus photos and fluorescein angiograms were reviewed. RESULTS There were 26 symptomatic eyes in 19 Asian patients with a median age of 73 years. Presenting visual symptoms included decreased visual acuity (19 eyes), metamorphopsia (5 eyes), or scotoma (2 eyes). Retinal findings included occult choroidal neovascularization (CNV) in 5 (19%) eyes, serous pigment epithelial detachment (PED) in 8 (31%) eyes, PED with CNV in 5 (19%) eyes, drusen in 5 (19%) eyes, retinal pigment epithelial atrophy in 1 (4%) eye, vitreous hemorrhage in 1 (4%) eye, and a disciform scar in 1 (4%) eye. CONCLUSION In this cohort of Asian patients with ARMD, the majority of symptomatic eyes had either CNV (46%) or serous PED (31%).
Experimental investigation of a three-dimensional bluff-body wake

The flowfield behind the wavy-cylinder geometry has been examined using flow visualization, total pressure surveys, and two-component laser Doppler anemometry. The topology of the boundary-layer separation line is linked to the subsequent three-dimensional development of the mean and turbulent structures of the wake. The formation of trailing streamwise vortices behind the nodal points of separation results in a locally narrower wake, a more rapid wake velocity recovery, and suppression of the turbulence development within the separated boundary layer. The dynamic behavior of the trailing vortices suggests that vortex pairing is suppressed by the presence of an axial strain field
Dynamics of flexible bodies in tree topology - A computer oriented approach

An approach suited for automatic generation of the equations of motion for large mechanical systems (i.e., large space structures, mechanisms, robots, etc.) is presented. The system topology is restricted to a tree configuration. The tree is defined as an arbitrary set of rigid and flexible bodies connected by hinges characterizing relative translations and rotations of two adjoining bodies. The equations of motion are derived via Kane's method. The resulting equation set is of minimum dimension. Dynamical equations are imbedded in a computer program called TREETOPS. Extensive control simulation capability is built in the TREETOPS program. The simulation is driven by an interactive set-up program resulting in an easy to use analysis tool.
In situ surface monitoring system for synchrotron mirrors under high heat load

A portable electro-optical system capable of real-time measurements of surface slope distortions down to 0.5 µrad is described; the system is limited primarily by its short-term stability. The system employs an angle measurement technique that, in combination with the least-squares signal extraction method, reduces system fluctuations. In addition, a multireflection technique is used to enhance the detectable resolution. Although designed for use with mirrors for synchrotron radiation sources, this system has the flexibility to be applied to other optical components. The prototype system has been tested on a sample mirror piece, and preliminary results are presented. A brief discussion about the extension of this metrology unit to adaptive optics is also given.
Self-Sensing in Fault Tolerant Magnetic Bearings

Several schemes have recently been proposed for achieving either fault tolerance or self-sensing in magnetic bearings. The present work describes the fundamental connection between ability to actuate and ability to sense in a partially failed magnetic bearing system. This relationship is then exploited to construct a self-sensing scheme which operates in the presence of detectable actuator or amplifier faults. Such an approach is advantageous in fault tolerant systems because it reduces or eliminates the need to address potential independent failure mechanisms in sensors and actuators. Based on a model reference parameter estimation mechanism, the self-sensing scheme is shown to provide acceptable position measurement accuracy and bandwidth under various actuator/amplifier faults which are actuator tolerable. Estimates of increase in noise floor and loss of bandwidth under fault conditions are provided. The issue of estimator convergence under fault conditions is examined in detail with comments on implementation complexity arising from scheduling convergence control on fault state.
Educational institutions as a “guidable” system

This essay attempts to apply a general theoretical form to the study of educational institutions. The theory's core assumption is that in conceptualizing and analyzing social dynamics one must carefully separate "change" from "guided change." (In the past, stress was often put on contrasting change with statics.) The reason for this is that if we seek to link analysis with policy making, the link must occur at the point where we separate changes which just happen, whether we desire them or not, from those we bring about deliberately. Above all, we must ask, Where are the levers? How can we guide change? But let us back step for a moment, to outline the condition we will examine. We see before us educational institutions, especially schools, charged with curricular and structural rigidities, with inability to adjust to the rapidly changing needs of the contemporary society. They are depicted as attempting to perpetuate lower-middle-class values, those closest to the hearts of teachers and small businessmen, to yesterday's America. Educational institutions are said to be unresponsive to the needs of pupils from disadvantaged backgrounds as well as alienating to upper-middleclass youths, who are no longer interested in hard work, or in adding to their affluence, but who seek a more hedonistic, reflective, cultural, or politically active life. Educational institutions are said to be slow to introduce the innovations necessary to keep the country at the forefront in scientific creativity and technological developments. Some critics go so far as to suggest doing away with education in schools and colleges, preferring the spontaneity of the streets and colleges "without walls" to contemporary "bureaucratic" education. Somewhat less extreme critics favor the establishment of a second layer of educational systems to circumvent the existing one, which is viewed as hopelessly obsolescent and "immune" to innovation. Without attempting to determine the extent to which American educational institutions have ossified, I will briefly indicate the factors which make for rigidity and the conditions under which the educational system may "loosen up." In doing so, I shall focus on those factors which are relatively movable; other factors need to be studied to gain a complete understanding of the educational world, but for policy makers and active citizens, the movable factors are of more interest.2 Limiting ourselves to these factors is possible because the movable factors are not linked to the
Phosphorus pentasulfide: A mild and versatile Catalyst/Reagent for the preparation of dithiocarboxylic esters

The reaction of carboxylic acids (1) with a variety of thiols or alcohols in the presence of phosphorus pentasulfide (P4S10) as a catalyst and reagent (20−40 mol %) proceeded effectively to afford the corresponding dithiocarboxylic esters (2) in high yields.
Photon Splitting in Soft Gamma Repeaters

The exotic quantum process of photon splittingϒ →ϒϒ has great potential to explain the softness of emission in soft gamma repeaters (SGRs) if they originate in neutron stars with surface fields above the quantum critical fieldB cr = 4.413×1013 Gauss. Splitting becomes prolific at such field strengths: its principal effect is to degrade photon energies, initiating a cascade that softens gamma-ray spectra. Uniform field cascade calculations have demonstrated that emission could be softened to the observed SGR energies for fields exceeding about 1014 Gauss. Recently, we have determined splitting attenuation lengths and maximum energies for photon escape in neutron star environments including the effects of magnetospheric dipole field geometry. Such escape energies eesc suitably approximate the peak energy of the emergent spectrum, and in this paper we present results fore esc as a function of photon emission angles for polar cap and equatorial emission regions. The escape energy is extremely insensitive to viewing perspective for equatorial emission, arguing in favour of such a site for the origin of SGR activity.
Geometric Mistuning Identification of Integrally Bladed Rotors Using Modified Modal Domain Analysis

Modified modal domain analysis (MMDA) is a novel method for the development of a reduced order model of a bladed rotor with geometric mistuning. This method utilizes proper orthogonal decomposition (POD) of coordinate measurement machine (CMM) data on blades' geometries, and sector analyses using ansys and solid modeling. In a recent paper, MMDA has been extended to use second order Taylor series approximations of perturbations in mass and stiffness matrices (δM and δK) instead of exact δM and δK. Taylor series expansions of deviations in mass and stiffness matrices due to geometric mistuning give a direct approach for generating the reduced order model from the components of POD features of spatial variations in blades' geometries. Reversing the process, algorithms for mistuning identification based on MMDA are presented in this paper to calculate the geometric mistuning parameters. Two types of algorithm, one based on modal analyses and the other on the forced responses, are presented. The validity of these methods are then verified through a mistuned academic rotor.
Total synthesis of (±) indolmycin

A practical and short synthesis of a novel antibiotic, (±) indolmycin, has been accomplished. The overall process requires only 4 chemical steps by starting from gramine derivative 3 and oxazolinone 2.
TESTING LONG-HORIZON PREDICTIVE ABILITY WITH HIGH PERSISTENCE, AND THE MEESE¿ROGOFF PUZZLE

A well-known puzzle in the international finance literature is that a random walk predicts exchange rates better than economic models (Meese and Rogoff, 1983a,b and 1988). This paper offers a potential explanation for this finding. When exchange rates and fundamentals are highly persistent, long-horizon forecasts of economic models are asymptotically biased by the estimation error in the parameter that measures the persistence. When this bias outweighs the benefits from exploiting economic information, the random walk model will forecast better. This happens even if the economic model is the true data generating process. The reason is that a random walk model imposes a unit root, rather than estimates it. The paper thus proposes a test for equal predictive ability in the presence of highly persistent variables. When applied to the Meese-Rogoff exercise, this test shows that the poor forecasting ability of economic models does not imply that the models are not a good description of the data.
Caustics, Cold Flows, and Annual Modulation

We discuss the formation of dark matter caustics, and their possible detection by future dark matter experiments. The annual modulation expected in the recoil rate measured by a dark matter detector is discussed. We consider the example of dark matter particles with a Maxwell-Boltzmann velocity distribution modified by a cold stream due to a nearby caustic. It is shown that the effect of the caustic flow is potentially detectable, even when the density enhancement due to the caustic is small. This makes the annual modulation effect an excellent probe of inner caustics. We also show that the phase of the annual modulation at low recoil energies does not constrain the particle mass unless the velocity distribution of particles in the solar neighborhood is known.
Normative ecological rationality: normative rationality in the fast-and-frugal-heuristics research program

The purpose of this paper is to examine the normative interpretation of the fast-and-frugal research program and in particular to contrast it with the normative reading of rational choice theory and behavioral economics. The ecological rationality of fast-and-frugal heuristics is admittedly a form of normative naturalism (Gigerenzer and Sturm 2012) – it derives what agents “ought” to do from that which “is” ecologically rational – and the paper will examine how this differs from the normative rationality associated with rational choice theory. I will also attempt to assess the relative adequacy of normative ecological rationality.
Theory of Moves: Overview and Examples:

“We discussed what the Soviet reaction would be to any possible move by the United States, what our reaction with them would have to be to that Soviet reaction, and so on, trying to follow each of those roads to their ultimate conclusion.” Theodore C. Sorensen about the deliberations of the Executive Committee during the October 1962 Cuban missile crisis (Holsti, Brody, and North, 1964: 188). “What are you going to do after that? Look ahead, look ahead-two or three or four steps ahead.” Mikhail S. Gorbachev to emissaries of the junta that staged the August 1991 attempted coup in the Soviet Union (Clines, 1991).
A semigroup proof of the bounded degree case of S.B. Rao's Conjecture on degree sequences and a bipartite analogue

S.B. Rao conjectured in 1980 that graphic degree sequences are well quasi ordered by a relation @? defined in terms of the induced subgraph relation (Rao, 1981 [7]). In 2008, M. Chudnovsky and P. Seymour proved this longstanding conjecture by giving structure theorems for graphic degree sequences (Chudnovsky and Seymour, in preparation [2]). In this paper, we prove and use a semigroup lemma to give a short proof of the bounded degree case of [email protected]?s Conjecture that is independent of the Chudnovsky-Seymour structure theory. In fact, we affirmatively answer two questions of N. Robertson (2006) [8], the first of which implies the bounded degree case of [email protected]?s Conjecture.
Crystallographic texture evolution in high-density polyethylene during uniaxial tension

Abstract This paper presents experimental measurements of crystallographic texture evolution in high-density polyethylene subjected to very large strains in uniaxial tension (up to a true strain of 2.1). The measurements presented here differ from prior studies in three important aspects: (1) The initial texture in the sample is quite strong with a large fraction of the crystallites oriented in an unstable orientation with the crystal c-axis perpendicular to the tensile axis of the sample. (2) Rigorous methods of texture analyses, based on spherical harmonics, have been applied to produce “complete, recalculated” pole figures based on diffraction data from five incomplete pole figures. (3) The measurements were performed while the samples were kept in the deformed state. The results presented here provide several new insights into texture development in tensile straining of high-density polyethylene to large strains. There are at least three distinct preferred orientations: (i) a component with (001) aligned along the extension axis, (ii) a component with (011) aligned close to the extension axis, and (iii) a component with (010) aligned along the extension axis. Note that only the first component has been reported to be stable at high strains in previous studies. The rate of texture evolution in the present study is significantly lower than that reported in previous studies. It was also observed that the natural relaxation of strain following the tensile loading had a significant impact on the texture in the sample. It was observed that the relaxation process mitigated or eliminated the second and third preferred texture components described above, while strengthening the first.
FKBP51 controls cellular adipogenesis through p38 kinase-mediated phosphorylation of GRα and PPARγ.

Glucocorticoid receptor-α (GRα) and peroxisome proliferator–activated receptor-γ (PPARγ) are critical regulators of adipogenic responses. We have shown that FK506-binding protein 51 (FKBP51) represses the Akt-p38 kinase pathway to reciprocally inhibit GRα but stimulate PPARγ by targeting serine 112 (PPARγ) and serines 220 and 234 (GRα). Here, this mechanism is shown to be essential for GRα and PPARγ control of cellular adipogenesis. In 3T3-L1 cells, FKBP51 was a prominent marker of the differentiated state and knockdown of FKBP51 showed reduced lipid accumulation and expression of adipogenic genes. Compared with wild-type (WT), FKBP51 knockout (51KO) mouse embryonic fibroblasts (MEFs) showed dramatic resistance to differentiation, with almost no lipid accumulation and greatly reduced adipogenic gene expression. These features were rescued by reexpression of FKBP51 in 51KO cells. 51KO MEFs exhibited reduced fatty acid synthase activity, increased sensitivity to GRα-induced lipolysis, and reduced PPARγ acti...
Explaining Agricultural Land Expansion and Deforestation in Developing Countries

In developing economies, especially those without oil and natural gas reserves, the most important source of natural wealth is agricultural land. In these economies, the agricultural land base is expanding rapidly through conversion of forests, wetlands, and other natural habitat (Barbier). Lopez identifies most of sub-Saharan Africa, parts of East and South East Asia, and the tropical forests of South America as regions with "abundant land" and open-access resource conditions that are prone to agricultural expansion. Widespread land and resource conversion is occurring in many of these areas, mainly due to the high degree of integration of rural areas with the national and international economy as well as population pressures. Agricultural land expansion in many tropical regions is also spurred by the poor intensification of agriculture in many tropical developing countries, where use of irrigation and fertilizer is low (FAO 1997; FAO 2003). This article explores further the economic factors underlying agricultural land expansion and tropical deforestation in developing countries. The main focus is on land-use change in the tropics, as this is where the majority of the world's poorest countries are located.1 The paper first provides a brief summary of
Cigarette prices and illicit drug use: is there a connection?

Using cross-sectional data from the United States, this study examines the effects of cigarette prices on the use of marijuana and illicit drugs (including marijuana, cocaine, heroin, inhalants, hallucinogens or any prescription drugs for nonmedical use). Five primary contributions of this work are: First, it provides evidence on the cross-relation between cigarettes and marijuana and illicit drugs. Second, besides the ‘standard’ control variables used in demand studies (namely, price, education and income), we also control for the influence of employment status and health insurance coverage. Third, this research provides new evidence on the price elasticity of cigarette demand for a recent time period. Fourth, the data used in this study are the latest available. Five, based on our results, implications for drug use policy are provided. Several key points may be noted from our results: (i) Cigarette demand seems to have become elastic in recent years. This is in contrast to findings in earlier years; (ii...
Controllability of open quantum systems with Kraus-map dynamics

This paper presents a constructive proof of complete kinematic state controllability of finite-dimensional open quantum systems whose dynamics are represented by Kraus maps. For any pair of states (pure or mixed) on the Hilbert space of the system, we explicitly show how to construct a Kraus map that transforms one state into another. Moreover, we prove by construction the existence of a Kraus map that transforms all initial states into a predefined target state (such a process may be used, for example, in quantum information dilution). Thus, in sharp contrast to unitary control, Kraus-map dynamics allows for the design of controls which are robust to variations in the initial state of the system. The capabilities of non-unitary control for population transfer between pure states illustrated for an example of a two-level system by constructing a family of non-unitary Kraus maps to transform one pure state into another. The problem of dynamic state controllability of open quantum systems (i.e., controllability of state-to-state transformations, given a set of available dynamical resources such as coherent controls, incoherent interactions with the environment, and measurements) is also discussed.