cssi/SciSciGPT-SciSciNet huggingface dataset:
Analog/hybrid: what it was, what it is, what it may be

The history of the analog computer goes back to antiquity, where tax maps were first reported being used for assessments and surveying. However, I shall confine this paper to the analog computer as it evolved from World War II to the present time. For those interested in the history of the analog computer, from antiquity to World War II, I refer the reader to an excellent introductory article by J. Roedel, Reference 1. The "Palimpsest" in which Roedel's history of the analog computing art is included is in itself an excellent history of analog computers in the early days dating from World War II to about 1954. From page 4 of the Palimpsest, I would like to show a diagram of computing devices as visualized by George Philbrick for an article in Industrial Laboratories in May, 1952. Of interest to us in this diagram on the analog side, is the separation, at the bottom, between fast and slow analog which I will discuss shortly. We will also note the presence of hybrid at the very top, and this article was written in 1952! Of course, Mr. Philbrick's "hybrid" was reserved for the use of the analog computer first to obtain a ball-park idea of a solution, then followed by a separate digital solution to obtain a more accurate answer to the same problem. I am certain that very few people thought of this as being hybrid computation at the time. However, consider this definition in the light of later work reported by Mark Connelly (Reference 2) in his use of a "skeleton" representation of a problem on the analog in conjunction with a more accurate representation of the problem on the digital.
Dense error correction via l1-minimization

We study the problem of recovering a non-negative sparse signal x ∈ ℝn from highly corrupted linear measurements y = Ax+e ∈ ℝm, where e is an unknown (and unbounded) error. Motivated by an observation from computer vision, we prove that for highly correlated dictionaries A, any non-negative, sufficiently sparse signal x can be recovered by solving an l1-minimization problem: min ‖x‖ 1 + ‖e‖ 1 subject to y = Ax + e. If the fraction ρ of errors is bounded away from one and the support of x grows sublinearly in the dimension m of the observation, for large m, the above l1-minimization recovers all sparse signals x from almost all sign-and-support patterns of e. This suggests that accurate and efficient recovery of sparse signals is possible even with nearly 100% of the observations corrupted.
Low-Temperature Polyol Synthesis of AuCuSn2 and AuNiSn2: Using Solution Chemistry to Access Ternary Intermetallic Compounds as Nanocrystals

Ternary intermetallic compounds, which possess a wide variety of important properties with both academic and technological relevance, are typically synthesized using traditional high-temperature me...
The Effect of Vesical Volume on Valsalva Leak-Point Pressures in Women With Genuine Stress Urinary Incontinence

Objective To determine the effect of increasing vesical volume on the Valsalva leak-point pressure, examine the relationship between leakage at a given volume and clinical incontinence severity, and evaluate the relationships between leakage at a given volume and other measures of urethral resistance. Methods One hundred twenty women with genuine stress urinary incontinence (GSI) underwent serial Valsalva leak-point pressure determinations at vesical volumes of 100, 200, and 300 mL, and at maximum cystometric capacity. Urinary diary data, quantitative pad testing, and passive and dynamic urethral profilometry were also performed. Results Thirty-three women had leakage starting at a vesical volume of 100 mL, 18 at 200 mL, and 19 at 300 mL, and 17 had leakage only at maximum cystometric capacity. The mean first positive Valsalva leak-point pressures were significantly higher than Valsalva leak-point pressures at maximum capacity in all groups: in women who began to leak at 100 mL, 57 versus 36 cm H 2 O ( P 2 O ( P 2 O ( P = .01). Women who had leakage at lower vesical volumes had worse measures of clinical incontinence severity and lower maximum urethral closure pressures ( P 2 O) and pure intrinsic sphincteric deficiency (low urethral pressure and the lack of urethral hypermobility), but the specificities were 63 and 50%, respectively. Conclusions Women with GSI are more likely to leak during Valsalva with increasing vesical volume. Valsalva leak-point pressures decrease significantly with bladder filling. The volume at which leakage occurs correlates inversely with clinical severity and directly with maximum urethral closure pressure. A negative Valsalva leak-point pressure at 300 mL excludes the presence of low urethral pressure and pure intrinsic sphincteric deficiency; however, the specificity and positive predictive value are inadequate for making a clinical diagnosis of either condition.
Message Dropping Attacks in Overlay Networks: Attack Detection and Attacker Identification

Overlay multicast networks are used by service providers to distribute contents such as Web pages, static and streaming multimedia data, or security updates to a large number of users. However, such networks are extremely vulnerable to message-dropping attacks by malicious or selfish nodes that intentionally drop the packets they are required to forward to others. It is difficult to detect such attacks both efficiently and effectively and to further identify the attackers, especially when members in the overlay switch between online/offline statuses frequently. In this article, we consider various attacking strategies of an attacker and propose an optimal sampling-based scheme to detect such attacks in the overlay network. We analyze the detection problem from a game-theoretical viewpoint and show that our scheme outperforms a random sampling-based scheme in terms of detection rate. In addition, based on a reputation system, we propose a sampling-based path-resolving scheme to identify compromised or selfish nodes. Unlike other existing approaches, our schemes do not assume global knowledge of the overlay hierarchy and work for dynamic overlay networks as well. Extensive analysis and simulation results show that besides being band width efficient, our schemes have high detection and identification rates and low false-positive rates.
Integrating decision support systems software into the curriculum for the master's degree in business administration

The development of intelligent systems has provided opportunities to integrate decision support system (DSS) software into the Master's degree in Business Administration (MBA) curriculum. This study addresses the relationship between MBA education and DSS technology. DSS software can be integrated into the MBA curriculum to facilitate the instructional process and the learning environment. Where-to-support, what-to-support, and how-to-support concepts are addressed. A prototyping process is suggested. The potential impact of DSS software on the MBA teaching environment is examined. Obstacles are also discussed.
The Domino Way to Heterocycles

Sequential transformations enable the facile synthesis of complex target molecules from simple building blocks in a single preparative step. Their value is amplified if they also create multiple stereogenic centers. In the ongoing search for new domino processes, emphasis is usually placed on sequential reactions which occur cleanly and without forming by-products. As a prerequisite for an ideally proceeding one-pot sequential transformation, the reactivity pattern of all participating components has to be such that each building block gets involved in a reaction only when it is supposed to do so. The development of sequences that combine transformations of fundamentally different mechanisms broadens the scope of such procedures in synthetic chemistry. This mini review contains a representative sampling from the last 15 years on the kinds of reactions that have been sequenced into cascades to produce heterocyclic molecules.
Novel characteristics of VUV insertion device beamlines at the advanced light source

Abstract The design of VUV beamlines for the Advanced Light Source is discussed. Features of the design serve to illustrate the careful attention required in order to preserve the performance of the low emittance “third-generation” storage ring, operating with insertion devices.
ABO blood type, factor VIII, and incident cognitive impairment in the REGARDS cohort

Objective: To assess the relationships among ABO group, factor VIII (FVIII), and incident cognitive impairment in a large, prospective cohort study of black and white adults in the United States using a nested case-control design. Methods: Incident cognitive impairment was defined using cognitive domain tests over a mean follow-up of 3.4 years. ABO blood group was measured by genotyping in a nested case-control sample of 495 cases with cognitive impairment and 587 controls. Results: Those with blood group AB and those with higher FVIII had an increased risk of cognitive impairment, adjusting for age, race, region, and sex (respective odds ratios 1.82, 95% confidence interval [CI] 1.15–2.90; and 1.24, 95% CI 1.10–1.38 for 40 IU/dL higher FVIII). Mean FVIII was higher in those with blood type AB (142 IU/dL; 95% CI 119–165) compared with O (104 IU/dL; 95% CI 101–107), and FVIII mediated 18% of the association between AB group and incident cognitive impairment (95% CI for mediation −30% to 68%). Conclusions: Blood group AB and higher FVIII were associated with increased incidence of cognitive impairment in this prospective study. The association of blood group AB with incident cognitive impairment was not significantly mediated by FVIII levels.
A GENERALIZED AFFINE ISOPERIMETRIC INEQUALITY

A purely analytic proof is given for an inequality that has as a direct consequence the two most important affine isoperimetric inequalities of plane convex geometry: The Blaschke-Santalo inequality and the affine isoperimetric inequality of affine differential geometry.
Einstein solid state spectrometer observation of the peculiar red dwarf Wolf 630 AB

Wolf 630 AB is a double and perhaps triple star with a predominant dM 3.5e spectrum. It is one of the relatively strong red dwarf X-ray sources. The 0.5 to 4 keV spectral data for a steady, non-flaring flux are interpreted in terms of emission from thin thermal plasma with a dominant temperature of approximately 6,500,000 K. Both in temperature and average surface flux the quiescent corona is similar to that of the low temperature component found for RS Canum Venaticorum binaries. There is an indication of additional emission above 10 to the 7th power K, but the ratio of high to low temperature emission is smaller than for typical RS CVn systems. The solid state spectrometer observed the spectrum of only one other red dwarf, Ad Leo, which is very similar to that observed for Wolf 630 AB.
Syn-selective additions of acetylide anions to α-alkoxyaldehydes

Abstract 1-Alkynyl zinc bromide reagents were found to add to α-benzyloxyaldehydes in ether solvent with good to excellent syn selectivity. A chelate model is proposed to explain these results.
Atomic and molecular properties of elements 112, 114, and 118.

The results of calculations outlining aspects of the chemistry of element 112, element 114, and element 118 are compared to those for their 6th row analogues Hg, Pb, and Rn, respectively. Element 112 and element 114 are found to be relatively inert as compared to Hg and Pb, while element 118 is much more active than radon. Spin−orbit coupling plays a dominant role in this behavior.
Natural gas demand by agriculture in the USA

Abstract This study sets out to determine whether agricultural consumers of natural gas are responsive to changes in the relative prices of different types of energy. A demand model is specified and estimated. The conclusions strongly suggest that not only is the price of natural gas a factor impacting the quantity of natural gas demanded by agriculture, but that other types of energy are substitutes for natural gas and that income and weather (measured by heating degree days) likewise affect natural gas demand.
X-ray spectroscopy of E2 and M3 transitions in Ni-like W

The electric quadrupole (E2) and magnetic octupole (M3) ground-state transitions in Ni-like W46+ have been measured using high-resolution crystal spectroscopy at the LLNL electron-beam ion trap facility. The lines fall in the soft x-ray region near 7.93 angstrom and were originally observed as an unresolved feature in tokamak plasmas. Using flat ammonium dihydrogen phosphate and quartz crystals, the wavelengths, intensities, and polarizations of the two lines have been measured for various electron-beam energies and compared to intensity and polarization calculations performed using the Flexible Atomic Code (FAC).
Measurements of thermophysical properties of molten silicon by a high-temperature electrostatic levitator

Several thermophysical properties of molten silicon measured by the high-temperature electrostatic levitator at JPL are presented. They are density, constant-pressure specific heat capacity, hemispherical total emissivity, and surface tension. Over the temperature range investigated (1350 less than T(sub m) less than 1825 K), the measured liquid density (in g/cc) can be expressed by a quadratic function, pi(P) = p(sub m) - 1.69 x 10(exp -4)(T - T(sub m)) - 1.75 x 10(exp -7)((T - T(sub m))(exp 2) with T(sub m) and p(sub m) being 1687 K and 2.56 g/cc, respectively. The hemispherical total emissivity of molten silicon at the melting temperature was determined to be 0.18, and the constant-pressure specific heat was evaluated as a function of temperature. The surface tension (in 10(exp -3) N/m) of molten silicon over a similar temperature range can be expressed by sigma(T) = 875 - 0.22( T - T(sub m)).
Do neutrinos have mass only within matter

Abstract We look at the possibility that appreciable neutrino masses and flavor mixing occur only within material media, driven by an interaction between leptons and a very light scalar particle. Limits are placed on the scalar particle mass and coupling constants from a number of experimental and astrophysical considerations.
Site occupancy in erbium-iron-manganese-boron alloys

Abstract The importance of the Nd 2 Fe 14 B tetragonal phase to permanent magnet technology has led to the study of systems with rare earth and transition metal substitutions. We have performed neutron diffraction experiments on such alloys formed by replacing iron with manganese in the Er 2 Fe 14 B system. Samples of Er 2 Fe 14− x Mn x B for x = 2, 3, 4, 6, 8 and 9 were prepared by induction melting and annealing at 1225 K for 100 h. Powder neutron diffraction at 393 K (above the Curie temperatures of each of these concentrations) revealed that manganese has a strong preference for the j 2 sites, which become essentially fully occupied with manganese for x = 9 (64%). As the j 2 sites saturate with manganese, the j 1 sites abruptly increase in manganese concentration. The remaining transition metal sites have fractional occupations of manganese which are below the overall stoichiometry.
ANTENNA LQG CONTROLLERS: PROPERTIES, LIMITS OF PERFORMANCE, AND TUNING PROCEDURE

Abstract The LQG controllers significantly improve antenna tracking precision, but their tuning is a trial-and-error process. A control engineer has two tools to tune an LQG controller: the choice of coordinate system of the controller, and the selection of weights of the LQG performance index. The paper selects the coordinates of the open-loop model that simplify the shaping of the closed-loop performance, and analyzes the impact of the weights on the antenna closed-loop bandwidth, disturbance rejection properties, and antenna acceleration. Finally, it presents the LQG controller tuning procedure that rationally shapes the closed-loop performance.
Selected-area deposition of multiple active films for conductometric microsensor arrays

Abstract A new generation of planar conductometric gas sensors is being developed which combines active semiconducting oxide films with Si-micromachined ‘micro-hotplate’ array structures. These devices are tailored for a variety of applications by tuning both the composition of multiple types of active films and the temperature cycles programmed for individual elements within an array. In this paper we described and demonstrate the approach, and present results for, a chemical vapor deposition (CVD)-based self-lithographic microfabrication method. This method is being examined as a highly efficient and compatible means of depositing oxide films and low-coverage catalytic metal overlayers on the microsensor elements of micro-hotplate arrays. Real-time monitoring of the film growth processe is provided by conductance measurements, and surveys of processing/property relationships can be performed in a very effective manner to determine optimal fabrication methods for multiple-active material arrays.
A Hierarchical Bayesian Procedure for Two-Mode Cluster Analysis.

This manuscript introduces a new Bayesian finite mixture methodology for the joint clustering of row and column stimuli/objects associated with two-mode asymmetric proximity, dominance, or profile data. That is, common clusters are derived which partition both the row and column stimuli/objects simultaneously into the same derived set of clusters. In this manner, interrelationships between both sets of entities (rows and columns) are easily ascertained. We describe the technical details of the proposed two-mode clustering methodology including its Bayesian mixture formulation and a Bayes factor heuristic for model selection. We present a modest Monte Carlo analysis to investigate the performance of the proposed Bayesian two-mode clustering procedure with respect to synthetically created data whose structure and parameters are known. Next, a consumer psychology application is provided examining physician pharmaceutical prescription behavior for various brands of prescription drugs in the neuroscience health market. We conclude by discussing several fertile areas for future research.
Infrared Nebulae around Young Stellar Objects

We present a K-band atlas of 106 reflection nebulae, 41 of which are new discoveries. We observed these nebulae with the University of Hawaii 2.2 m telescope in the course of an imaging survey of 197 objects that were selected as nearby young Class I sources. K-band images and flux-calibrated surface brightness contour plots of each nebula are presented. We found that the near-IR luminosities and physical sizes of the nebulae increase with the bolometric luminosity of the illuminating sources. Only 22 nebulae, about 10% of these candidate Class I sources, have indications of shocked H2 emission. The great variety of nebulae that we observed prevented us from classifying them based on morphology. However, we note that as the spectral index decreases, the central star is more frequently visible at K band, and the flux from the central star tends to be dominant over the flux from the nebula. For objects that have a higher spectral index, most of the K-band flux is from the reflection nebula, and the central star is less frequently visible. The nebula around IRAS 05450+0019 has a unique morphology, and we speculate that it may be an example of a disk shadow being projected into the surrounding cloud. We present J-, H-, and K-band images of this object with surface brightness contours, as well as its spectral energy distribution from 1.2 to 100 μm.
Hawking's chronology protection conjecture: singularity structure of the quantum stress-energy tensor

Abstract The recent renaissance of wormhole physics has led to a very disturbing observation: If traversable wormholes exist then it appears to be rather easy to transform such wormholes into time machines. This extremely disturbing state of affairs has lead Hawking to promulgate his chronology protection conjecture. This paper continues a program begun in an earlier paper. An explicit calculation of the vacuum expectation value of the renormalized stress-energy tensor in wormhole spacetimes is presented. Point-splitting techniques are utilized. Particular attention is paid to computation of the Green function (in its Hadamard form), and the structural form of the stress-energy tensor near short self-intersecting spacelike geodesics. Detailed comparisons with previous calculations are presented, leading to a pleasingly unified overview of the situation.
From Ritual to Reality: Demography, Ideology, and Decoupling in a Post-Communist Government Agency

Decoupling—the creation of gaps between formal policies and actual practices—is ubiquitous in organizations. Yet little research has examined how decoupling unfolds over time. This qualitative case study of a post-Communist government agency develops process models of what precedes and what follows the decision to decouple. I show that the demography and ideology of powerful organization members influence whether decoupling occurs, how it unfolds, and whether it is sustainable. Further, I suggest decoupling may carry seeds of its own decay: under certain conditions, the decision to decouple can trigger demographic changes that eventually erode decoupling.
Evolution of the discrepancy between a universe and its model

We study a fundamental issue in cosmology: whether we can rely on a cosmological model to understand the real history of the Universe. This fundamental, still unresolved issue is often called the 'model-fitting problem (or averaging problem) in cosmology'. Here we analyse this issue with the help of the spectral scheme prepared in the preceding studies. Choosing two specific spatial geometries , and, ' that are very close to each other, we investigate explicitly the time evolution of the spectral distance between them; as two spatial geometries , and, ', we choose a flat 3-torus and a perturbed geometry around it, mimicking the relation of a 'model universe' and the 'real Universe'. Then we estimate the spectral distance between them, dN(, '), and investigate its time evolution explicitly. This analysis is done efficiently by making use of the basic results of the standard linear structure-formation theory. We observe that, as far as the linear approximation of the geometrical perturbation is valid, dN(, ') does not increase with time prominently, rather it shows a tendency to decrease. This result is compatible with the general belief in the reliability of describing the Universe by means of a model and calls for more detailed studies along the same lines including the investigation of a wider class of spacetimes and analysis beyond the linear regime.
Sections of Calabi-Yau threefolds with K3 fibration

We study sections of a Calabi-Yau threefold fibered over a curve by K3 surfaces. We show that there exist infinitely many isolated sections on certain K3 fibered Calabi-Yau threefolds and the subgroup of the N\'eron-Severi group generated by these sections is not finitely generated. This also gives examples of K3 surfaces over the function field F of a complex curve with Zariski dense F-rational points, whose geometric model is Calabi-Yau.
Maximizing job completions online

We consider the problem of maximizing the number of jobs completed by their deadline in an online single processor system where the jobs are preemptable and have release times. So in the standard three field scheduling notation, this is the online version of the problem 1 |ri; pmtn| Σ(1 - Ui). We present a deterministic algorithm Lax, and show that for every instance I, it is the case that either Lax, or the well-known deterministic algorithm SRPT (Shortest Remaining Processing Time), is constant competitive on I. An immediate consequence of this result is a constant competitive randomized algorithm for this problem. It is known that no constant competitive deterministic algorithm exists for this problem.
Shape memory alloy fracture as a deployment actuator

The paper reports an experimental investigation into using shape memory alloy (SMA) as a deployment actuator. SMA specimens were heated and pulled to failure or pulled and heated to failure, thus developing an environmental and structural operating envelope for application as deployment mechanisms. The experimental results strongly suggest that SMAs can be implemented as deployment actuators. Recorded data shows that SMA fracture is possible over a wide range of temperatures and strains, filling a material performance gap not found in the literature. The obtained information allows design engineers to appropriately size SMAs given the design requirements for achieving the desired deployment effects. The major conclusion of the reported work is that SMAs as actuators are strong competitors to typical existing deployment efforts that use explosive or non-explosive actuators having implementation drawbacks such as the expense associated with special handling and the volume encountered in mounting the devices.
Poised Chromatin at the ZEB1 Promoter Enables Breast Cancer Cell Plasticity and Enhances Tumorigenicity

The recent discovery that normal and neoplastic epithelial cells re-enter the stem cell state raised the intriguing possibility that the aggressiveness of carcinomas derives not from their existing content of cancer stem cells (CSCs) but from their proclivity to generate new CSCs from non-CSC populations. Here, we demonstrate that non-CSCs of human basal breast cancers are plastic cell populations that readily switch from a non-CSC to CSC state. The observed cell plasticity is dependent on ZEB1, a key regulator of the epithelial-mesenchymal transition. We find that plastic non-CSCs maintain the ZEB1 promoter in a bivalent chromatin configuration, enabling them to respond readily to microenvironmental signals, such as TGFβ. In response, the ZEB1 promoter converts from a bivalent to active chromatin configuration, ZEB1 transcription increases, and non-CSCs subsequently enter the CSC state. Our findings support a dynamic model in which interconversions between low and high tumorigenic states occur frequently, thereby increasing tumorigenic and malignant potential.
Sink or Swim? Firms' Responses to Underwater Options

We examine changes in executive compensation that firms make in response to underwater options. Using a sample of firms with underwater options in 2000, we estimate that 81 percent of firms take action to respond to them. We examine explanations for the firms' responses. Opponents argue that it rewards poor performance and transfers wealth unjustifiably from shareholders to executives. We find some support for this argument in that firms with weaker governance structures are more likely to reprice underwater options. Alternatively, firms that respond claim they do so to restore incentives, retain executives, and insulate executives from market‐wide or industry‐wide factors beyond their control. Our results find evidence in support of these arguments in that restoring incentives and retaining executives seem to be the primary drivers of firms' responses.
Orientational invariance of the rotational transition probability in the sudden approximation

Semiclassical collisions of an atom with a rigid-rotor molecule are examined in the sudden approximation. The rotational transition probability is shown to be invariant with respect to the choice of orientation for the molecular coordinate system; this fact contradicts recently reported results of a computer analysis. The present analysis may lead to an improved interpretation of recent molecular beam measurements.
Light-scattering coefficient of seawater for arbitrary concentrations of hydrosols

The scattering coefficient of water as a function of concentration of hydrosol particles is calculated. A new quantum-mechanical approach to calculate the multiple-scattering phenomenon in seawater is proposed. The approach is based on Maxwell’s equations for the light fields in stochastically scattering water with hydrosols. The water is modeled as a thermally fluctuating medium filled with the particles. It is found that at small concentrations of scatterers the scattering coefficient is linear in the concentration. At higher values of concentrations the dependence on the concentration may be approximated by a power law.
The trophic-dynamic aspect of ecology*

Recent progress in the study of aquatic food-cycle relationships invites a reappraisal of certain ecological tenets. Quantitative productivity data provide a basis for enunciating certain trophic principles, which, when applied to a series of successional stages, shed new light on the dynamics of ecological succession.
Monobromoborane–Dimethyl Sulfide—a Highly Promising Reagent for the Regio- and Chemoselective Brominative Cleavage of Terminal Epoxides into Vicinal Bromohydrins

Monobromoborane–dimethyl sulfide (BH2Br–SMe2) is a highly regio- and chemoselective reagent useful for the brominative cleavage of the epoxy moiety into bromohydrins in the presence of alkenes, alkynes, ethers, acetals, ketals, and acetonides at 0°C, besides being an excellent hydroborating reagent. Several reactive functional groups, such as chloride, ketones, esters, nitriles, nitros, and thioethers, have been accommodated during such transformations. Although the reduction of acetophenone was completely suppressed at –25°C, 4-chlorobenzaldehyde still underwent 12–13% reduction of an aldehydic group.
Three-dimensional FDTD simulation of biomaterial exposure to electromagnetic nanopulses

Ultra-wideband (UWB) electromagnetic pulses of nanosecond duration, or nanopulses, have recently been approved by the Federal Communications Commission for a number of different applications. They are also being explored for applications in biotechnology and medicine. The simulation of the propagation of a nanopulse through biological matter, previously performed using a two-dimensional finite-difference time-domain (FDTD) method, has been extended here into a full three-dimensional computation. To account for the UWB frequency range, the geometrical resolution of the exposed sample was 0.25 mm and the dielectric properties of biological matter were accurately described in terms of the Debye model. The results obtained from the three-dimensional computation support the previously obtained results: the electromagnetic field inside a biological tissue depends on the incident pulse rise time and width, with increased importance of the rise time as the conductivity increases; no thermal effects are possible for the low pulse repetition rates, supported by recent experiments. New results show that the dielectric sample exposed to nanopulses behaves as a dielectric resonator. For a sample in a cuvette, we obtained the dominant resonant frequency and the Q-factor of the resonator.
Synthesis of 1,2- and 1,3-Dicarboxylic Acids via Pd(II)-Catalyzed Carboxylation of Aryl and Vinyl C−H Bonds

A Pd(II)-catalyzed reaction protocol for the direct carboxylation of benzoic and phenylacetic acid derivatives to form dicarboxylic acids has been developed. The reaction conditions are also applicable for the carboxylation of vinyl C-H bonds. The first C-H insertion Pd-aryl complex from carboxylic acids has been characterized by X-ray crystallography.
Optimality conditions in generalized geometric programming

Generalizations of the Kuhn-Tucker optimality conditions are given, as are the fundamental theorems having to do with their necessity and sufficiency.
Gamma-Ray Bursts with Continuous Energy Injection and Their Afterglow Signature

We consider generically the problem of a gamma-ray burst (GRB) fireball with an additional energy injection, either in the form of a Poynting-flux-dominated outflow or a kinetic-energy-dominated matter shell injected after the burst. Generally, a total injection energy comparable to that of the impulsive energy in the initial fireball is required to make a detectable signature in the afterglow light curves. When this criterion is met in the case of Poynting-flux-dominated injection, this leads to a gradual achromatic bump appearing in the otherwise power-law afterglow light curve. Alternatively, in the case when the injection is kinetic-energy-dominated, the results depend on whether the collision between the rear (injected) and the forward shell is mild or violent. If the relative velocity between the colliding shells does not exceed a critical value defined by their energy ratio, the collision is mild, and the injection may be analogous to the Poynting-flux injection case. Otherwise, the injection is violent, and an additional pair of strong shocks will form at the discontinuity between two colliding shells, so that there are altogether three shock-heated regions from which the emission contributes to the final light curves. We describe the shell-merging process in detail, including collision and relaxation, by taking into account the dynamical evolution and the emission from the various shocks involved. Assuming synchrotron emission, we calculate afterglow light curves in the X-ray, optical, and radio bands for the various cases. The injection signatures due to violent matter-dominated collisions are abrupt and complicated, because of the emission from any of the three emitting regions and depending on the injection parameters and the observed energy bands. This differs from the gradual bump signature found in the Poynting-flux injection case. In both the Poynting-flux-dominated and the kinetic-energy-dominated cases, the energetics of the fireball as well as the absolute afterglow flux level after the injection are boosted with respect to the one without postburst injection. Identifying the different injection signatures from future early afterglow observations may provide diagnostics about the nature of the fireball and of the central engine.
Well-corrected Two-element Telescope with a Flat Image

The three element Schmidt-Cassegrain telescope is a well-known catadioptric system that can be corrected for spherical aberration, coma, astigmatism and Petzval curvature. This paper describes a ve...
Energy vs the environment

Optimal development programs that explicitly account for the environmental impacts of extracting and consuming energy resources are analyzed. Following Lee and Orr (1975), we allow for the possibility of storing the resource above ground once it has been extracted. When environmental disruption results from resource extraction (as in the case of strip mining) or there are environmental costs associated with resource consumption (for example, the social costs of air pollution from fuel consumption), then the socially optimal rates of resource consumption and extraction depend on the severity of the environmental impact and on the prospects of storing the resource above ground.
Walverine: a Walrasian trading agent

TAC-02 was the third in a series of Trading Agent Competition events fostering research in automating trading strategies by showcasing alternate approaches in an open-invitation market game. TAC presents a challenging travel-shopping scenario where agents must satisfy client preferences for complementary and substitutable goods by interacting through a variety of market types. Michigan's entry, Walverine, bases its decisions on a competitive (Walrasian) analysis of the TAC travel economy. Using this Walrasian model, we construct a decision-theoretic formulation of the optimal bidding problem, which Walverine solves in each round of bidding for each good. Walverine's optimal bidding approach, as well as several other features of its overall strategy, are potentially applicable in a broad class of trading environments.
The multi-objective constrained assignment problem

Assignment problems are a common area of research in operational research and computer science. Military applications include military personnel assignment, combat radio frequency assignment, and weapon target assignment. In general, assignment problems can be found in a wide array of areas, from modular placement to resource scheduling. Many of these problems are very similar to one another. This paper models and compares some of the assignment problems in literature. These similar problems are then generalized into a generalized multi-objective problem, the constrained assignment problem. Using a multi-objective genetic algorithm, we solve an example of a constrained assignment problem called the airman assignment problem. Results show that good solutions along the interior portion of the Pareto front are found in earlier generations and later generations produce more exterior points.
Palomar/Las Campanas Imaging Atlas of Blue Compact Dwarf Galaxies. II. Surface Photometry and the Properties of the Underlying Stellar Population

We present the results from an analysis of surface photometry of B, R, and Hα images of a total of 114 nearby galaxies (v_helio < 4000 km s^-1) drawn from the Palomar/Las Campanas Imaging Atlas of blue compact dwarf (BCD) galaxies. Surface brightness and color profiles for the complete sample have been obtained. We determine the exponential and Sersic profiles that best fit the surface brightness distribution of the underlying stellar population detected in these galaxies. We also compute the (B - R) color and total absolute magnitude of the underlying stellar population and compared them to the integrated properties of the galaxies in the sample. Our analysis shows that the (B - R) color of the underlying population is systematically redder than the integrated color, except in those galaxies where the integrated colors are strongly contaminated by line and nebular-continuum emission. We also find that galaxies with relatively red underlying stellar populations [typically (B - R) ≥ 1 mag] show structural properties compatible with those of dwarf elliptical galaxies (i.e., a smooth light distribution, fainter extrapolated central surface brightness, and larger scale lengths than BCD galaxies with blue underlying stellar populations). At least ~15% of the galaxies in the sample are compatible with being dwarf elliptical (dE) galaxies experiencing a burst of star formation. For the remaining BCD galaxies in the sample we do not find any correlation between the recent star formation activity and their structural differences with respect to other types of dwarf galaxies.
The circular RFQ storage ring

This paper presents a novel idea of storage ring for the accumulation of intense beams of light and heavy ions at low energy. The new concept is a natural development of the combined features of conventional storage rings and ion traps, and is basically a linear RFQ bent on itself. The advantages are: smaller beam dimensions, higher beam intensity, and a more compact storage device.
Tardiness bounds under global EDF scheduling on a multiprocessor

We consider the scheduling of a sporadic real-time task system on an identical multiprocessor. Though Pfair algorithms are theoretically optimal for such task systems, in practice, their runtime overheads can significantly reduce the amount of useful work that is accomplished. On the other hand, if all deadlines need to be met, then every known non-Pfair algorithm requires restrictions on total system utilization that can approach approximately 50% of the available processing capacity. This may be overkill for soft real-time systems, which can tolerate occasional or bounded deadline misses (i.e. bounded tardiness). In this paper we derive tardiness bounds under preemptive and non-preemptive global $\mathsf{EDF}$ when the total system utilization is not restricted, except that it not exceed the available processing capacity. Hence, processor utilization can be improved for soft real-time systems on multiprocessors. Our tardiness bounds depend on the total system utilization and per-task utilizations and execution costs--the lower these values, the lower the tardiness bounds. As a final remark, we note that global $\mathsf{EDF}$ may be superior to partitioned $\mathsf{EDF}$ for multiprocessor-based soft real-time systems in that the latter does not offer any scope to improve system utilization even if bounded tardiness can be tolerated.
Identity-Based Encryption from the Weil Pairing

We propose a fully functional identity-based encryption (IBE) scheme. The scheme has chosen ciphertext security in the random oracle model assuming a variant of the computational Diffie--Hellman problem. Our system is based on bilinear maps between groups. The Weil pairing on elliptic curves is an example of such a map. We give precise definitions for secure IBE schemes and give several applications for such systems.
Interfacing interactive data analysis tools with the grid: The PPDG CS-11 activity

For today's physicists, who work in large geographically distributed collaborations, the data grid promises significantly greater capabilities for analysis of experimental data and production of physics results than is possible with today's ''remote access'' technologies. The goal of letting scientists at their home institutions interact with and analyze data as if they were physically present at the major laboratory that houses their detector and computer center has yet to be accomplished. The Particle Physics DataGrid project (www.ppdg.net) has recently embarked on an effort to ''Interface and Integrate Interactive Data Analysis Tools with the grid and identify Common Components and Services.'' The initial activities are to collect known and identify new requirements for grid services and analysis tools from a range of current and future experiments (ALICE, ATLAS, BaBar, D0, CMS, JLab, STAR, others welcome), to determine if existing plans for tools and services meet these requirements. Follow-on activities will foster the interaction between grid service developers, analysis tool developers, experiment analysis frame work developers and end user physicists, and will identify and carry out specific development/integration work so that interactive analysis tools utilizing grid services actually provide the capabilities that users need. This talk will summarize what we know ofmore » requirements for analysis tools and grid services, as well as describe the identified areas where more development work is needed.« less
AFM's path to atomic resolution

We review progress in improving the spatial resolution of atomic force microscopy (AFM) under vacuum. After an introduction to the basic imaging principle and a conceptual comparison to scanning tunneling microscopy (STM), we outline the main challenges of AFM as well as the solutions that have evolved in the first 20 years of its existence. Some crucial steps along AFM's path toward higher resolution are discussed, followed by an outlook on current and future applications.
Decoding Spatial Complexity in Strongly Correlated Electronic Systems

Inside the metals, semiconductors, and magnets of our everyday experience, electrons are uniformly distributed throughout the material. By contrast, electrons often form clumpy patterns inside of strongly correlated electronic systems (SCES) such as colossal magnetoresistance materials and high temperature superconductors. In copper-oxide-based high temperature superconductors, scanning tunneling microscopy (STM) has detected an electron nematic on the surface of the material in which the electrons form nanoscale structures which break the rotational symmetry of the host crystal. These structures may hold the key to unlocking the mystery of high temperature superconductivity in these materials, but only if the nematic also exists throughout the entire bulk of the material. Using newly developed methods for decoding these surface structures, we find that the nematic indeed persists throughout the bulk of the material. We furthermore find that the intricate pattern formation is set by a delicate balance among disorder, interactions, and material anisotropy, leading to a fractal nature of the cluster pattern. The methods we have developed can be extended to many other surface probes and materials, enabling surface probes to determine whether surface structures are confined only to the surface or whether they extend throughout the material.
A “strange” vector-valued quantum modular form

Since their definition in 2010 by Zagier, quantum modular forms have been connected to numerous topics such as strongly unimodal sequences, ranks, cranks, and asymptotics for mock theta functions near roots of unity. These are functions that are not necessarily defined on the upper half plane but a priori are defined only on a subset of \({\mathbb{Q}}\), and whose obstruction to modularity is some analytically “nice” function. Motivated by Zagier’s example of the quantum modularity of Kontsevich’s “strange” function F(q), we revisit work of Andrews, Jimenez-Urroz, and Ono to construct a natural vector-valued quantum modular form whose components are similarly “strange”.
Voltage-controlled magnetic anisotropy in spintronic devices

Electric-field-control of magnetism can dramatically improve the energy efficiency of spintronic devices and enhance the performance of magnetic memories. More generally, it expands the range of applications of nonvolatile spintronic devices, by making them energetically competitive compared to conventional semiconductor solutions for logic and computation, thereby potentially enabling a new generation of ultralow-power nonvolatile spintronic systems. This paper reviews recent experiments on the voltage-controlled magnetic anisotropy (VCMA) effect in thin magnetic films, and their device implications. The interfacial perpendicular anisotropy in layered magnetic material stacks, as well as its modulation by voltage, are discussed. Ferromagnetic resonance experiments and VCMA-induced high-frequency magnetization dynamics are reviewed. Finally, we discuss recent progress on voltage-induced switching of magnetic tunnel junction devices and its potential applications to magnetic random access memory (MRAM).
Comparison theorems, numerical integration and satellite orbits

A comparison theorem estimating the difference between solutions of a perturbed and unperturbed equation is obtained. This is then applied to obtain error estimates in numerical integration problems, in particular, those problems involving computation of satellite orbits. The main result is a proof of the intuitive notion that the error in numerically integrating a stable equation grows less rapidly than for an unstable equation.
Turbomachine Blade Row Interaction Predictions with a Three-Dimensional Finite Element Method

High-cycle fatigue (HCF) is a key issue for the advancement of gas-turbine performance and endurance. Models simulating the cyclic aerodynamic forces experienced by gas-turbine vanes are necessary to make quantitative predictions of HCF during design. Although such models exist, there is an urgent need to compare them with benchmark data to assess their accuracy and reliability. In this study, TAM-ALE3D is utilized to simulate the inlet guide vane (IGV) and rotor blade rows in the Purdue Transonic Compressor at both part-speed and design-speed conditions. Of particular interest is the unsteady flow in the IGV row generated by the part-speed potential field and the design-speed shock system generated by the downstream rotor. To assess the accuracy of the TAM-ALE3D predictions, the 90% span instantaneous IGV vane-to-vane flowfield and vane surface pressures are correlated with appropriate state-of-the-art data.
Transition from collisional to kinetic regimes in large-scale reconnection layers

Using first-principles fully kinetic simulations with a Fokker-Planck collision operator, it is demonstrated that Sweet-Parker reconnection layers are unstable to a chain of plasmoids (secondary islands) for Lundquist numbers beyond S >{approx} 1000. The instability is increasingly violent at higher Lundquist number, both in terms of the number of plasmoids produced and the super-Alfvenic growth rate. A dramatic enhancement in the reconnection rate is observed when the half-thickness of the current sheet between two plasmoids approaches the ion inertial length. During this transition, the reconnection electric field rapidly exceeds the runaway limit, resulting in the formation of electron-scale current layers that are unstable to the continual formation of new plasmoids.