cssi/SciSciGPT-SciSciNet huggingface dataset:
On lower complexity bounds for large-scale smooth convex optimization

We derive lower bounds on the black-box oracle complexity of large-scale smooth convex minimization problems, with emphasis on minimizing smooth (with Holder continuous, with a given exponent and constant, gradient) convex functions over high-dimensional ? ? ? p -balls, 1 ? p ? ∞ . Our bounds turn out to be tight (up to logarithmic in the design dimension factors), and can be viewed as a substantial extension of the existing lower complexity bounds for large-scale convex minimization covering the nonsmooth case and the "Euclidean" smooth case (minimization of convex functions with Lipschitz continuous gradients over Euclidean balls). As a byproduct of our results, we demonstrate that the classical Conditional Gradient algorithm is near-optimal, in the sense of Information-Based Complexity Theory, when minimizing smooth convex functions over high-dimensional ? ? ? ∞ -balls and their matrix analogies-spectral norm balls in the spaces of square matrices.
A versatile one-pot procedure for the insertion of a 3-substituent into 2-cycloalkenones

Abstract 1-Trimethylsilylbenzotriazole was used to form 1,4-adducts with 2-cycloalkenones which were treated in situ with base and electrophile to give, upon hydrolysis, a variety of 3-substituted 2-cycloalkenones in moderate yield.
Applications of wavelet transform for analysis of freeway traffic: Bottlenecks, transient traffic, and traffic oscillations

This paper demonstrates the capabilities of wavelet transform (WT) for analyzing important features related to bottleneck activations and traffic oscillations in congested traffic in a systematic manner. In particular, the analysis of loop detector data from a freeway shows that the use of wavelet-based energy can effectively identify the location of an active bottleneck, the arrival time of the resulting queue at each upstream sensor location, and the start and end of a transition during the onset of a queue. Vehicle trajectories were also analyzed using WT and our analysis shows that the wavelet-based energies of individual vehicles can effectively detect the origins of deceleration waves and shed light on possible triggers (e.g., lane-changing). The spatiotemporal propagations of oscillations identified by tracing wavelet-based energy peaks from vehicle to vehicle enable analysis of oscillation amplitude, duration and intensity.
KNOTS WITH INFINITELY MANY INCOMPRESSIBLE SEIFERT SURFACES

We show that a knot in S3 with an infinite number of incompressible Seifert surfaces contains a closed non-peripheral incompressible surface in its complement.
Control during Corporate Crisis: Asbestos and the Manville Bankruptcy:

Chapter 11 bankruptcy provides an opportunity for addressing issues of power and control during corporate crisis. A broad notion of power is essential in understanding the complex events that led to the Chapter 11 filing of the Manville Corporation, formerly the nation's leading asbestos manufacturer. The theory of finance hegemony places this case in an entirely new light by taking into account the power of the financial community. The Manville bankruptcy illuminates several mechanisms by which this hegemony operates. From this perspective, Chapter 11 bankruptcy is viewed as a choice made from a set of options severely constrained by other powerful institutions, rather than a result of managerial incompetence or market failure.
Observations of quantum dynamics by solution-state NMR spectroscopy

NMR is emerging as a valuable testbed for the investigation of foundational questions in quantum mechanics. The present article outlines the preparation of a class of mixed states, called pseudo-pure states, that emulate pure quantum states in highly mixed solution-state NMR samples. It also describes the NMR observation of spinor behavior in spin ½ nuclei, the simulation of wave function collapse using a magnetic field gradient, the creation of entangled (i.e., Bell) pseudo-pure states, and a brief discussion of quantum computing logic gates including the Quantum Fourier Transform. These experiments show that solution-state NMR can be used to demonstrate quantum dynamics at a level suitable for laboratory exercises. ©1999 John Wiley & Sons, Inc. Concepts Magn Reson 11: 225–238, 1999
The "Regulatory Compact" and Implicit Contracts: Should Stranded Costs be Recoverable?

Progress toward electricity market deregulation has brought controversy over whether or not utilities are entitled to compensation for "stranded costs", i.e., costs utilities will not be able to recover due to the advent of competition in their markets. This paper uses a legal and economic analysis of contracts to address the desirability of utility cost recovery. First, underlying principles of law are reviewed to determine whether or not there is a legal presumption of recovery. Then, the analysis considers whether or not an implicit "regulatory compact n between utilities and regulators follows from principles in the economic analysis of law, particularly theories of efficient breach and implicit contracts. The paper concludes that recovery should occur in only a proscribed set of circumstances and that, when called for, compensation should be partial, rather than full.
Does Crime Pay? A Classroom Demonstration of Monitoring and Enforcement

This article presents a classroom game in which students choose whether or not to comply with pollution regulations. By varying the level of monitoring and fines for noncompliance, the game shows students how the probability and severity of enforcement affects incentives for compliance. The game can be adapted for settings other than environmental regulation and can be used in a variety of classes including regulation, law and economics, environmental economics, public economics, or economics of crime classes. It can easily be conducted in a 50-minute class period.
Novel aspheric surfaces for optical design

New functional representations are needed for describing aspheric surfaces that can compensate for a high degree of wavefront asphericity and represent steeply sloped surfaces as the surface normal becomes perpendicular to the optical axis. The explicit definition of the standard aspheric surface limits the range of surfaces that it can properly describe. This paper presents both a parametrically defined surface approach and an implicitly defined surface approach. The utility of these novel approaches is demonstrated using examples of current interest. Additionally, this work shows that a Fourier series is not a useful optical surface.
Illiquidity Risk in Non-Listed Funds: Evidence from REIT Fund Exits and Redemption Suspensions

Managerial incentives are skewed in non-listed funds under finite horizons. Compensation structures are only indirectly related to shareholder wealth maximization when share prices are unobservable. Liquidity options for investors are limited in the absence of an exchange listing. Using a hand-collected database for public non-listed REITs, an empirical sequence considers the impact of management compensation contracts on equity fundraising and success in capital deployment. Evidence is provided that high asset management fees and high acquisition fees diminish managerial success at generating revenue from invested capital. Successful revenue flows are deterministic factor in the level of distributions paid and the likelihood of achieving a fund exit. Closing the gate on share redemption plans is synchronized with the slowdown in new equity flows. Retail investors are insensitive to maligned compensation structures that heighten illiquidity risk, even when observable in the prospectus.
High Redshift Galaxies in the Hubble Ultra Deep Field

My dissertation presents results from three recent investigations in the Hubble Ultra Deep Field (HUDF) focusing on understanding structural and physical properties of high redshift galaxies. Here I summarize results from these studies. Thesis work conducted at: Arizona State University, Tempe, AZ 85287 Ph.D. Thesis directed by: Rogier Windhorst and Sangeeta Malhotra Ph.D. Degree awarded: August 2008 Subject headings: Dissertation Summary
A Tale of Two Communities: Explaining Deforestation in Mexico

Summary Deforestation policies in Mexico need to recognize heterogeneity in community’s management schemes. In communities that extract wood from the forest for profit, forestry projects generate funds whose investment in public goods increases the value of standing forest to those not receiving direct dividends from the projects. Increases in such investment help decrease deforestation. In communities with other livelihoods, deforestation decreases with the community’s ability to form a coalition that cooperates in reducing forest clearing. This is easier in smaller communities with more experienced leaders. Analysis using data collected in 2002 combined with satellite imagery verifies the models’ predictions.
Eigenstates of the Atom–Field Interaction and the Binding of Light in Photonic Crystals

Abstract We give a particle description of atom–field eigenstates in a three-dimensional spherical geometry of infinite volume by mapping the problem onto the anisotropic Kondo model. The spectrum has a rich bound state structure in comparison with models where the rotating wave approximation is made. It is shown how to obtain the Jaynes–Cummings model states in the limit of weak coupling. Nonperturbative Lamb shifts and decay rates are computed. The massive Kondo model is introduced to model light localization in the form of photon–atom bound states in photonic crystals.
A short total synthesis of (+)-furanomycin.

Furanomycin is a Streptomyces metabolite that substitutes for isoleucine in protein translation. We report a concise and modular synthesis starting from the Garner aldehyde and proceeding in seven ...
Bispherical constrained lens antennas

A bispherical constrained lens having two surfaces of equal radii has been known to provide multiple beams with true time delay and no feed blockage. A generalized bispherical constrained lens with the radii of its two surfaces being allowed to vary is described. This additional degree of freedom can be used in limited coverage applications to make the lens more compact, in terms of total lens surface, compared to the equal radii case.
Whole crustal response to late Tertiary extension near Prince Rupert, British Columbia

Crust-penetrating multichannel seismic data imaged crustal features of late Tertiary extension in east Dixon Entrance, British Columbia. The data show grabens as much as 3 km deep, mid-crustal west-dipping refl ecting packages interpreted as normal sense shear zones, middle to lower crustal subhorizontal refl ecting horizons, a generally refl ective Moho, and arches of the Moho with relief of as much as 3 km (Moho depths 24.8‐ 27.5 km). Based on dated extension-related features reported for the region, east-west extension occurred between 40 and 20 Ma and may have been concentrated between 25 and 20 Ma. If the pre‐late Tertiary crustal thickness of east Dixon Entrance was the same as that of the mainland to the east (34 km), the minimum amount of crustal thinning in the study area was 30%. Thinning of the whole crust above a stronger mantle lithosphere is implied by the extension-related features that we describe from the brittle upper crust down through the ductile lower crust to the Moho. Our data confi rm and extend the interpretation of crustal extension by Lowe and Dehler and Dehler et al. for Hecate Strait and Queen Charlotte Sound. Integration of our results with the geologic history across the study area leads to a conclusion that preexisting zones of weakness may have controlled the pattern of crustal thinning during the extension.
An aerobot for global in situ exploration of Titan

Abstract This paper describes the design and component testing of an aerobot that would be capable of global in situ exploration of Saturn’s moon, Titan, over a 6–12 month mission lifetime. The proposed aerobot is a propeller-driven, buoyant vehicle that resembles terrestrial airships. However, the extremely cold Titan environment requires the use of cryogenic materials of construction and careful thermal design for protection of temperature-sensitive payload elements. Multiple candidate balloon materials have been identified based on extensive laboratory testing at 77 K. The most promising materials to date are laminates comprised of polyester fabrics and/or films with areal densities in the range of 40–100 g/m 2 . The aerobot hull is a streamlined ellipsoid 14 m in length with a maximum diameter of 3 m. The enclosed volume of 60 m 3 is sufficient to float a mass of 234 kg at a maximum altitude of 8 km at Titan. Forward and aft ballonets are located inside the hull to enable the aerobot to descend to the surface while preserving a fully inflated streamlined shape. Altitude changes are effected primarily through thrust vectoring of the twin main propellers, with pressure modulated buoyancy change via the ballonets available as a slower backup option. A total of 100 W of electrical power is provided to the vehicle by a radioisotope power supply. Up to half of this power is available to the propulsion system to generate a top flight speed in the range of 1–2 m/s. This speed is expected to be greater than the near surface winds at Titan, enabling the aerobot to fly to and hover over targets of interest. A preliminary science payload has been devised for the aerobot to give it the capability for aerial imaging of the surface, atmospheric observations and sampling, and surface sample acquisition and analysis. Targeting, hovering, surface sample acquisition and vehicle health monitoring and automatic safing actions will all require significant on-board autonomy due to the over 2 h round trip light time between Titan and Earth. An autonomy architecture and a core set of perception, reasoning and control technologies is under development using a free-flying airship testbed of approximately the same size as the proposed Titan aerobot. Data volume from the Titan science mission is expected to be on the order of 100–300 Mbit per day transmitted either direct to Earth through an 0.8 m high gain antenna or via an orbiter relay using an omni-directional antenna on the aerobot.
Ameliorating mental mistakes in tradeoff studies

Tradeoff studies are broadly recognized and mandated as the method for simultaneously considering multiple alternatives with many criteria, and as such are recommended in the Capability Maturity Model Integration (CMMI) Decision Analysis and Resolution (DAR) process. Tradeoff studies, which involve human numerical judgment, calibration, and data updating, are often approached with under confidence by analysts and are often distrusted by decision makers. The decision-making fields of Judgment and Decision Making, Cognitive Science and Experimental Economics have built up a large body of research on human biases and errors in considering numerical and criteria-based choices. Relationships between experiments in these fields and the elements of tradeoff studies show that tradeoff studies are susceptible to human mental mistakes: This paper indicates ways to eliminate the presence, or ameliorate the effects of mental mistakes on tradeoff studies. © 2007 Wiley Periodicals, Inc. Syst Eng 10: 222–240, 2007 This work was supported by the Air Force Office of Scientific Research under AFOSR/MURI F49620-03-1-0377.
Perverse Sheaves on affine Grassmannians and Langlands Duality

This is an expanded version of the text ``Perverse Sheaves on Loop Grassmannians and Langlands Duality'', AG/9703010. The main new result is a topological realization of algebraic representations of reductive groups over arbitrary rings. We outline a proof of a geometric version of the Satake isomorphism. Given a connected, complex algebraic reductive group G we show that the tensor category of representations of the Langlands dual group is naturally equivalent to a certain category of perverse sheaves on the loop Grassmannian of G. The above result has been announced by Ginsburg in and some of the arguments are borrowed from his approach. However, we use a more "natural" commutativity constraint for the convolution product, due to Drinfeld. Secondly, we give a direct proof that the global cohomology functor is exact and decompose this cohomology functor into a direct sum of weights. The geometry underlying our arguments leads to a construction of a canonical basis of Weyl modules given by algebraic cycles and an explicit construction of the group algebra of the dual group in terms of the affine Grassmannian. We completely avoid the use of the decomposition theorem which makes our techniques applicable to perverse sheaves with coefficients over an arbitrary commutative ring. We deduce the classical Satake isomorphism using the affine Grassmannian defined over a finite field. This note contains indications of proofs of some of the results. The details will appear elsewhere.
Quantum random number generators and their use in cryptography

Random number generators (RNG) are an important resource in many areas: cryptography (both quantum and classical), probabilistic computation (Monte Carlo methods), numerical simulations, industrial testing and labeling, hazard games, scientific research, etc. Because today's computers are deterministic, they can not create random numbers unless complemented with a RNG. Randomness of a RNG can be precisely, scientifically characterized and measured. Especially valuable is the information-theoretic provable RNG (True RNG — TRNG) which, at state of the art, seem to be possible only by use of physical randomness inherent to certain (simple) quantum systems. On the other hand, current industry standard dictates use of RNG's based on free running oscillators (FRO) whose randomness is derived from electronics noise present in logic circuits and which cannot be strictly proven. This approach is currently used in 3-rd and 4-th generation FPGA and ASIC hardware, unsuitable for realization of quantum TRNG. We compare weak and strong aspects of the two approaches and discuss possibility of building quantum TRNG in the recently appeared Mixed Signal FPGA technology. Finally, we discuss several examples where use of a TRNG is critical and show how it can significantly improve security of cryptographic systems.
Some Families of Directed Strongly Regular Graphs Obtained from Certain Finite Incidence Structures

We present many new directed strongly regular graphs by direct construction. We construct these graphs on the collections of antiflags of certain finite incidence structures. In this way, we confirm the feasibility of infinitely many parameter sets that was previously undetermined. We describe some examples of graphs together with their isomorphism classes to demonstrate the fact that our construction method is capable of producing many graphs with same parameters.
Viscous relaxation of impact crater relief on Venus: Constraints on crustal thickness and thermal gradient

Models for the viscous relaxation of impact crater topography are used to constrain the crustal thickness (H) and the mean lithospheric thermal gradient beneath the craters on Venus. A general formulation for gravity-driven flow in a linearly viscous fluid has been obtained which incorporates the densities and temperature-dependent effective viscosities of distinct crust and mantle layers. An upper limit to the crustal volume of Venus of 10 to the 10th cu km is obtained which implies either that the average rate of crustal generation has been much smaller on Venus than on earth or that some form of crustal recycling has occurred on Venus.
Molecular Mixing in a Turbulent Flow: Some Fundamental Considerations

Abstract A transport or evolution equation for the joint PDF of a reacting scalar and the gradient of that scalar is developed and presented. The derivation clearly indicates the relationship between the transport equation for the PDF of a reacting scalar and the transport equation for the joint PDF. It also demonstrates why molecular mixing cannot be modelled exactly in the simpler equation governing the PDF. Transport in scalar space due to chemical reaction and molecular mixing and transport in scalar gradient space due to chemical reaction are represented exactly. The molecular mixing results in an inverse diffusion process in time. Transport in scalar gradient space due to molecular mixing and vortex dynamics is identified and modelled via physical arguments. Nondimensionalization of the equation yields the important nondimensional groupings and demonstrates the multi-time scale nature of the problem
The Kinetic Limit of a System of Coagulating Brownian Particles

We consider a random model of diffusion and coagulation. A large number of small particles is randomly scattered in \(\mathbb{R}^d\) at an initial time. Each particle has some integer mass and moves as a Brownian motion whose rate of diffusion is determined by that mass. When any two particles are close, they are liable to combine into a single particle that bears the mass of each of them. The range of interaction between pairs of particles is chosen so that a typical particle is liable to interact with a unit order of other particles in a unit of time. We determine the macroscopic evolution of the system, in any dimension d ≧ 3. The density of particles evolves according to the Smoluchowski system of partial differential equations, indexed by the mass parameter, in which the interaction term is a sum of products of densities. Central to the proof is the task of establishing the so-called Stosszahlansatz, which asserts that, at any given time, the presence of particles of two given masses at any given point in macroscopic space is asymptotically independent, as the initial number of particles is taken to be high. Nonetheless, there is, in a microscopic region about each particle, a reduced probability of finding another particle. Determining this deficit precisely is necessary in computing the coefficients appearing in the interaction terms of the Smoluchowski partial differential equation.
How geography affects quality

Abstract This paper connects the quality of product-level bilateral trade flows with the geographic position of the exporter. Theoretically we show that, in addition to commonly used importer characteristics, quality increases (i) in trade-weighted specific transportation cost to destinations other than the importer and (ii) in trade-weighted preference for quality of destinations other than the importer. These two channels extend the familiar Alchian–Allen and Linder theories to the multilateral setting. The data confirm the theoretical prediction. Non-OECD exporters who face a stronger demand for quality from richer countries charge about 10% more for all destinations. At the same time, countries whose demand is especially distorted by the Alchian–Allen effect charge 58% more. Moreover, geography is more significant to the quality choice of developing countries. Multilateral geographic factors explain 13% of the price variation for non-OECD exporters, 3% for small OECD exporters, and are not significant for OECD exporters overall.
Venture Creation and the Enterprising Individual: A Review and Synthesis

Venture creation is at the heart of entrepreneurship. Enterprising individuals or groups start new ventures and, thus, we must understand the role of individuals if we are to understand venture creation. In this article, we review and critique the venture creation literature that has examined the role of the individual, with an eye toward identifying under-researched topics and improving research designs. We then highlight individual judgment as a particularly important future direction for research on the role of enterprising individuals in venture creation. We also discuss techniques for accessing entrepreneurs and for evaluating entrepreneurial judgments.
AXION-DILATON BLACK HOLES.

In this talk some essential features of stringy black holes are described. We consider charged four-dimensional axion-dilaton black holes. The Hawking temperature and the entropy of all solutions are shown to be simple functions of the squares of supercharges, defining the positivity bounds. Spherically symmetric and multi black hole solutions are presented. The extreme solutions have some unbroken supersymmetries. Axion-dilaton black holes with zero entropy and zero area of the horizon form a family of stable particle-like objects, which we call holons. We discuss the possibility of splitting of nearly extreme black holes into holons.
Techniques used in the F-14 variable-sweep transition flight experiment

This paper discusses and evaluates the test measurement techniques used to determine the laminar-to-turbulent boundary layer transition location in the F-14 variable-sweep transition flight experiment (VSTFE). The main objective of the VSTFE was to determine the effects of wing sweep on the laminar-to-turbulent transition location at conditions representative of transport aircraft. Four methods were used to determine the transition location: (1) a hot-film anemometer system; (2) two boundary-layer rakes; (3) surface pitot tubes; and (4) liquid crystals for flow visualization. Of the four methods, the hot-film anemometer system was the most reliable indicator of transition.
New integrable systems from unitary matrix models

Abstract We show that the one-dimensional unitary matrix model with potential of the form aU + bU 2 +h.c. is integrable. By reduction to the dynamics of the eigenvalues, we establish the integrability of a system of particles in one space dimension in an external potential of the form a cos( x + α )+ b cos(2 x + β ) and interacting though two-body potentials of the inverse sine square type. This system constitutes a generalization of the Sutherland model in the presence of external potentials. The positive-definite matrix model, obtained by analytic continuation, is also integrable, which leads to the integrability of a system of particles in hyperbolic potentials interacting through two-body potentials of the inverse hyperbolic sine square type.
Para-H2 to ortho-H2 conversion in a full-scale automotive cryogenic pressurized hydrogen storage up to 345 bar

Abstract Hydrogen vehicles offer the potential to improve energy independence and lower emissions but suffer from reduced driving range. Cryogenic pressure vessel storage (also known as cryo-compressed storage) offers the advantage of higher densities than room temperature compressed although it has the disadvantage of cryogenic operating temperatures which results in boil-off when the temperature of the gas increases. In order to understand and optimize the time prior to boil-off, we have examined heat absorption from the transition between the two quantum states of the hydrogen molecule (para–ortho) in a full-scale (151 L internal volume) automotive cryogenic pressure vessel at pressures and temperatures up to 345 bar and 300 K, and densities between 14 and 67 g/L (2.1–10.1 kg H 2 ). The relative concentration of the two species was measured using rotational Raman scattering and verified by calorimetry. In fifteen experiments spanning a full year, we repeatedly filled the vessel with saturated LH 2 at near ambient pressure (2–3 bar), very low temperatures (20.3–25 K), varying densities, and very high para-H 2 fraction (99.7%). We subsequently monitored vessel pressure and temperature while performing periodic ortho-H 2 concentration measurements with rotational Raman scattering as the vessel warmed up and pressurized due to environmental heat entry. Experiments show that para–ortho H 2 conversion typically becomes active after 10–15 days of dormancy (“initiation” stage), when H 2 temperature reaches 70–80 K. Para–ortho H 2 conversion then approaches completion (equilibrium) in 25–30 days, when the vessel reaches 100–120 K at ∼50 g/L density. Warmer temperatures are necessary for conversion at lower densities, but the number of days remains unchanged. Vessel dormancy (time that the vessel can absorb heat from the environment before having to vent fuel to avoid exceeding vessel rating) increased between 3 and 7 days depending on hydrogen density, therefore indicating a potentially large benefit for reduced fuel venting in cryogenic pressurized hydrogen storage.
Noncausal effects in relativistic wave equations

Manifestly covariant wave equations describing particles with a unique mass and spin can, for certain types of external-field interactions, possess noncausal solutions. The paper reports a procedure for applying Pierce decomposition of all six couplings expressed in the Duffin-Kemmer-Petiau spin-0 formula. This treatment converts the equation to a form in which the causal properties are apparent. The conditions under which the causal properties of higher-spin equations can be made manifest are discussed.
Optimal trade, industrial, and privatization policies in a mixed duopoly with strategic managerial incentives

Abstract This paper examines optimal trade, industrial, and privatization policies in a home-market model of mixed international duopoly with strategic managerial incentives. Under linear demand and constant marginal costs, the optimal degree of privatization is shown to depend crucially on cost and demand parameters and on the availability of strategic trade and industrial policies. If both firms are equally efficient, optimal trade and industrial policies drive out the foreign firm and the privatization policy loses its effect on national welfare; however, if the home firm is less efficient, then full privatization combined with an import tariff and a production subsidy is optimal for the home country, while an export subsidy is optimal for the foreign country. If trade and industrial policies are unavailable and if both firms are equally efficient, full state-ownership, which drives out the foreign firm, becomes optimal; however, if the home firm is less efficient, only partial privatization is optimal...
The diastereofacial selectivity in the intramolecular 1,4-conjugate additions generating substituted tetrahydrothiopyrans follows the Cieplak model

Abstract 2-Alkyl-3-Alkoxytetrahydrothiopyrans were prepared by intramolecular Michael additions. The predominant cis product stereochemistry is consistent with the Cieplak model. A low-energy σ ‡ ∗ orbital originating from the sulfur nucleophile was proposed. The solvent effect was also discussed.
Higher ramification loci over homogeneous spaces

We generalize the Gaffney–Lazarsfeld theorem on higher ramification loci of branched coverings of \({\mathbb{P}^{n}}\) to homogeneous spaces with Picard number one.
Computational Analysis of Centrifugal Compressor Surge Control Using Air Injection

A Navier-Stokes solver for simulating unsteady viscous e uid e ow in turbomachinery components has been developed and used to study e uid dynamic phenomena that lead to instabilities in centrifugal compressors. These studies indicate that large e ow incidence angles, at reduced e ow rates, can cause boundary-layer separation near the blade leading edge. High-pressure jets upstream of the compressor face are studied as a means of controlling compressor instabilities. Steady jets are found to alter the leading-edge e ow pattern and effectively suppress compressorinstabilities.Itisalsoobservedthatyawedjetsaremoreeffectivethanparalleljetsandthatanoptimum yaw angle exists for each compression system. Pulsed jets can yield additional performance enhancements and lead to a reduction in external air requirements for operating the jets. Jets pulsed at higher frequencies perform better than low-frequency jets. HE stable operating regime of current generation centrifugal compressors is limited at reduced mass e ow rates by two e uid dynamic phenomena: rotating stall and surge. The occurrence of these phenomena dee nes the surge limit, also referred to as stall line. When operating a compression system under these conditions, stronge uctuationsandlimitcycleoscillationscancauselargevibra- tions, leading to fatigue and damage of the entire compression unit. Unsteady e uctuations, caused by rotating stall or surge, may lead to excessive heating of the impeller blades and can produce additional periodicloadson theimpeller,resultinginincreasedoperating noise levels. If the e uctuations are left unchecked, even a complete e ow re- versal is possible, a situation that a compressor cannot tolerate. Because of the severity of these hazardous conditions, centrifugal compressors are conservatively designed to operate well below the peak pressure rise point. A safety margin of 10 -20% is generally introduced between the surge line and the design operating condi- tion. Most compressor control systems currently used in industry are based on this strategy, called avoidance control. Signie cant progress has been made in the past several years to develop reliable compressor control schemes. These schemes em- ploy fast-response-stall-detection devices, in most cases circumfer- entially distributed over thecasing walls thatmeasure e owe eld data and send e ltered signals to a controller unit. When a compressor approaches a stall-like condition, the presence of growing insta- bilities, sometimes called stall precursor waves, is measured and signaled back to the controller unit before the actual stall process begins. The control mechanism is then activated by a direct link be- tween the controller and a set of high-bandwidth actuation devices. The type of control system is often categorized by the choice of a particular actuator.
Experimental and Theoretical Methods to Investigate Extraframework Species in a Layered Material of Dodecaniobate Anions

The highly charged dodecaniobate Keggin ions [XNb12O40]-16 (X = Si, Ge) and [XNb12O40]-15 (X = P) serve as building blocks of self-assembled, low-dimensional anionic framework materials. In addition to its high charge, the Keggin ion provides optimal binding geometries that render these materials as attractive metal sorbents and ion exchangers. We describe here the synthesis and single-crystal X-ray structure of K10-x[Nb2O2][HxGeNb12O40]·11H2O (GeNb12-2d; x = ∼1−1.5), a phase featuring 2D linkage of [GeNb12O40]-16 Keggin ions interlayered with charge-balancing K+ cations and water molecules. Thermogravimetry, infrared spectroscopy (IR), 1H MAS NMR, and D2O exchange experiments as well as computational studies were used to describe the location and behavior of these interlayer, extraframework species. To model the basicity of the different types of framework oxygen sites appropriately, atomic-centered partial charges were derived from density functional theory (DFT) calculations to model the electrostatic ...
Polynomial hulls and an optimization problem

We say that a subset of Cn is hypoconvex if its complement is the union of complex hyperplanes. We say it is strictly hypoconvex if it is smoothly bounded hypoconvex and at every point of the boundary the real Hessian of its defining function is positive definite on the complex tangent space at that point. Let Bn be the open unit ball in Cn.Suppose K is a C∞ compact manifold in ∂B1 × Cn, n > 1, diffeomorphic to ∂B1 × ∂Bn, each of whose fibers Kz over ∂B1 bounds a strictly hypoconvex connected open set. Let K be the polynomialhull of K. Then we show that K∖K is the union of graphs of analytic vector valued functions on B1. This result shows that an unnatural assumption regarding the deformability of K in an earlier version of this result is unnecessary. Next, we study an H∞ optimization problem. If pis a C∞ real-valued function on ∂B1× Cn, we show that the infimum γρ = infƒ∈H ∞ (B1)n ‖ρ(z, ƒ (z))‖∞ is attained by a unique bounded ƒ provided that the set (z, w) ∈ ∂B1 × C n¦ρ(z, w) ≤ γρ has bounded connected strictly hypoconvex fibers over the circle.
Lane identification and path planning for autonomous mobile robots

This work has been performed in conjunction with the University of Detroit Mercy's (UDM) ECE Department autonomous vehicle entry in the 2006 Intelligent Ground Vehicle Competition (www.igvc.org). The IGVC challenges engineering students to design autonomous vehicles and compete in a variety of unmanned mobility competitions. The course to be traversed in the competition consists of a lane demarcated by painted lines on grass with the possibility of one of the two lines being deliberately left out over segments of the course. The course also consists of other challenging artifacts such as sandpits, ramps, potholes, and colored tarps that alter the color composition of scenes, and obstacles set up using orange and white construction barrels. This paper describes a composite lane edge detection approach that uses three algorithms to implement noise filters enabling increased removal of noise prior to the application of image thresholding. The first algorithm uses a row-adaptive statistical filter to establish an intensity floor followed by a global threshold based on a reverse cumulative intensity histogram and a priori knowledge about lane thickness and separation. The second method first improves the contrast of the image by implementing an arithmetic combination of the blue plane (RGB format) and a modified saturation plane (HSI format). A global threshold is then applied based on the mean of the intensity image and a user-defined offset. The third method applies the horizontal component of the Sobel mask to a modified gray scale of the image, followed by a thresholding method similar to the one used in the second method. The Hough transform is applied to each of the resulting binary images to select the most probable line candidates. Finally, a heuristics-based confidence interval is determined, and the results sent on to a separate fuzzy polar-based navigation algorithm, which fuses the image data with that produced by a laser scanner (for obstacle detection).
Missed Opportunities: Clinical Antecedents in the Diagnosis of Advanced Breast Cancer

Background Locally advanced breast cancer (LABC) often requires complex treatment, and the prognosis is typically poor. We hypothesize that LABC patients engage the healthcare system with a variant pattern as compared with patients diagnosed with early stage disease.
Information Technology and Organizational Change

The profession of technical communication is in transition. While a few might argue that we are in danger of being swallowed up by large, institutional realignments, it seems more likely that the future workplace (as characterized by Senge, among others) will put communication, culture, and collaboration at the center of work. However, in order for the profession to exploit these opportunities, we must understand the impact of integrated information technology (IT) on organizations. I summarize the interaction of corporate culture, leadership/management, human resources, and advanced networking and web-based applications (more commonly called an Intranet) for the successful integration of new IT products into an established and well-defined organization. Background research for this paper was conducted as part of an Army Summer Faculty Research and Engineering grant.
Tidal dissipation, orbital evolution, and the nature of Saturn's inner satellites

Estimates of tidal damping times of the orbital eccentricities of Saturn's inner satellites place constraints on some satellite rigidities and dissipation functions Q. These constraints favor rock-like rather than ice-like properties for Mimas and probably Dione. Photometric and other observational data are consistent with relatively higher densities for these two satellites, but require lower densities for Tethys, Enceladus, and Rhea. This leads to a nonmonotonic density distribution for Saturn's inner satellites, apparently determined by different mass fractions of rocky materials. In spite of the consequences of tidal dissipation for the orbital eccentricity decay and implications for satellite compositions, tidal heating is not an important contributor to the thermal history of any Saturnian satellite.
Option Pricing in the Large Risk Aversion, Small Transaction Cost Limit

We characterize the price of a European option on several assets for a very risk-averse seller, in a market with small transaction costs as a solution of a nonlinear diffusion equation. This problem turns out to be one of asymptotic analysis of parabolic PDE, and the interesting feature is the role of a nonlinear PDE eigenvalue problem. In particular, we generalize previous work of Guy Barles and H. Mete Soner who studied this problem for a European option on a single asset.
High-resolution adaptive optics scanning laser ophthalmoscope with dual deformable mirrors for large aberration correction

Scanning laser ophthalmoscopes with adaptive optics (AOSLO) have been shown previously to provide a noninvasive, cellular-scale view of the living human retina. However, the clinical utility of these systems has been limited by the available deformable mirror technology. In this paper, we demonstrate that the use of dual deformable mirrors can effectively compensate large aberrations in the human retina, making the AOSLO system a viable, non-invasive, high-resolution imaging tool for clinical diagnostics. We used a bimorph deformable mirror to correct low-order aberrations with relatively large amplitudes. The bimorph mirror is manufactured by Aoptix, Inc. with 37 elements and 18 mm stroke in a 10 mm aperture. We used a MEMS deformable mirror to correct high-order aberrations with lower amplitudes. The MEMS mirror is manufactured by Boston Micromachine, Inc with 144 elements and 1.5 mm stroke in a 3 mm aperture. We have achieved near diffraction-limited retina images using the dual deformable mirrors to correct large aberrations up to ±3D of defocus and ±3D of cylindrical aberrations with test subjects. This increases the range of spectacle corrections by the AO systems by a factor of 10, which is crucial for use in the clinical environment. This ability for large phase compensation can eliminate accurate refractive error fitting for the patients, which greatly improves the system ease of use and efficiency in the clinical environment.
Adaptive cosine transform image coding with variable block size and constant block distortion

An adaptive discrete cosine transform (DCT) image coding system is implemented with the same average distortion designated for each variable size image block. The variable block size segmentation is performed using a quadtree data structure by dividing the perceptually more important regions of an image into smaller size blocks compared to the size of blocks containing lesser amounts of spatial activity. Due to the nonstationarity of real-world images, each image block is described by a space-varying nonstationary Gauss-Markov random field. The space-varying autoregressive parameters are estimated using an on-line modified least- squares estimator. For each assumed space-varying nonstationary image block, a constant average distortion is assigned and the code rate for each image block is allowed to vary in order to meet the fixed distortion criterion. Simulation results show that reconstructed images coded at low average distortion, based on an assumed space-varying nonstationary image model, using variable size blocks and with variable bit rate per block possess high-quality subjective (visual) and objective (measured) quality at low average bit rates. Performance gains are achieved due to the distortion being distributed more uniformly among the blocks as compared with fixed-rate, stationary image transform coding schemes.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Palladium-Catalyzed Cyclization/Carboalkoxylation of Alkenyl Indoles

Reaction of 1-methyl-2-(4-pentenyl)indole with a catalytic amount of PdCl2(CH3CN)2 (5 mol %) and a stoichiometric amount of CuCl2 (3 equiv) in methanol under CO (1 atm) at room temperature for 30 min led to cyclization/carboalkoxylation to form the corresponding tetrahydrocarbazole in 83% isolated yield as a single regioisomer. Palladium-catalyzed cyclization/carboalkoxylation of 2-(4-pentenyl)indoles tolerated substitution along the alkenyl chain and at the internal and cis-terminal olefinic positions. Palladium-catalyzed cyclization/carboalkoxylation tolerated a range of alcohols and was effective for the cyclization of 2-(3-butenyl)indoles, 3-(3-butenyl)indoles, 3-(4-pentenyl)indoles, and 2-(5-hexenyl)indoles.
Synthesis of Pterocarpan-Type Heterocycles via Oxidative Cycloadditions of Phenols and Electron-Rich Arenes

Abstract Oxidation of 4-alkoxyphenols or 4-methoxynaphthol with phenyl iodonium(bis)trifluoroacetate (PIFA) in the presence of electron rich 2H-chromenes or dihydronaphthalenes affords pterocarpans or 5-carbapterocarpans via a formal [3 + 2] cycloaddition process. Acid-catalyzed ionization of quinone dimethylmonoacetal in the presence of 7-methoxy-2H-chromene gave similar results, suggesting a phenoxonium ion intermediate in the oxidative process.
A Role for Repressive Histone Methylation in Cocaine-Induced Vulnerability to Stress

Substance abuse increases an individual's vulnerability to stress-related illnesses, which is presumably mediated by drug-induced neural adaptations that alter subsequent responses to stress. Here, we identify repressive histone methylation in nucleus accumbens (NAc), an important brain reward region, as a key mechanism linking cocaine exposure to increased stress vulnerability. Repeated cocaine administration prior to subchronic social defeat stress potentiated depressive-like behaviors in mice through decreased levels of histone H3 lysine 9 dimethylation in NAc. Cre-mediated reduction of the histone methyltransferase, G9a, in NAc promoted increased susceptibility to social stress, similar to that observed with repeated cocaine. Conversely, G9a overexpression in NAc after repeated cocaine protected mice from the consequences of subsequent stress. This resilience was mediated, in part, through repression of BDNF-TrkB-CREB signaling, which was induced after repeated cocaine or stress. Identifying such common regulatory mechanisms may aid in the development of new therapies for addiction and depression.
The Generalized Method of Moments for Electromagnetic Boundary Integral Equations

The generalized method of moments (GMM) is a partition of unity based technique for solving electromagnetic and acoustic boundary integral equations. Past work on GMM for electromagnetics was confined to geometries modeled by piecewise flat tessellations and suffered from spurious internal line charges. In the present article, we redesign the GMM scheme and demonstrate its ability to model scattering from PEC scatterers composed of mixtures of smooth and non-smooth geometrical features. Furthermore, we demonstrate that because the partition of unity provides both functional and effective geometrical continuity between patches, GMM permits mixtures of local geometry descriptions and approximation function spaces with significantly more freedom than traditional moment methods.
Diastereoselective addition of alkynylstannanes to alpha stannyl substituted mixed acetals: Synthesis of precursors for allenyl carbinols

Abstract The regio- and stereoselective addition of alkynylstannanes to stannyl substituted mixed acetals results in propargylic ether derivatives in excellent yields.
Regioselective palladium-catalyzed arylation of 2-furaldehyde.

An efficient regioselective method for the direct arylation of 2-furaldehyde to provide a range of π-diverse 5-aryl-2-formylfuran derivatives is described. The method employs functionalized aryl halides and a catalytic amount of palladium(II) chloride under relatively mild conditions.