cssi/SciSciGPT-SciSciNet huggingface dataset:
THE EFFECT OF LOCAL ECONOMIC DEVELOPMENT POLICY ON EMPLOYMENT GROWTH IN RURAL COUNTIES IN THE MID-ATLANTIC REGION

The research objective of this paper is to examine the effect of the local economic development activities of nonmetro counties in Delaware, Maryland, Pennsylvania, Virginia and West Virginia on local employment growth.
An Introduction to Decision Theory

This introduction to decision theory offers comprehensive and accessible discussions of decision-making under ignorance and risk, the foundations of utility theory, the debate over subjective and objective probability, Bayesianism, causal decision theory, game theory, and social choice theory. No mathematical skills are assumed, and all concepts and results are explained in non-technical and intuitive as well as more formal ways. There are over 100 exercises with solutions, and a glossary of key terms and concepts. An emphasis on foundational aspects of normative decision theory (rather than descriptive decision theory) makes the book particularly useful for philosophy students, but it will appeal to readers in a range of disciplines including economics, psychology, political science and computer science.
Trade Policy and Economic Performance in Sub-Saharan Africa

This study focuses on the role of trade and trade policy in achieving sustained long-term growth in Africa. One major conclusion is that trade policy in Sub-Saharan Africa works much the same way that it does elsewhere. High levels of trade restrictions have been an important obstacle to exports in the past, and their reduction can be expected to result in significantly improved trade performance in the region. There is little ground for pessimism in this respect, or for concern that Africa's different conditions poor infrastructure, geography, or dependence on a limited number of primary products make it a special case in which exports are not responsive to prices or to the traditional instruments of commercial policy. At the same time, the effects of trade policy on economic growth seem to be indirect and much more modest. The fundamentals for long-term growth are human resources, physical infrastructure, macroeconomic stability, and the rule of law.
NDE for Characterizing Oxidation Damage in Reinforced Carbon-Carbon Used on the NASA Space Shuttle Thermal Protection System

In this study, a coated reinforced carbon-carbon (RCC) sample of the same structure and composition as that from the NASA space shuttle orbiter's thermal protection system was fabricated to have predictable oxidation damage. The sample was fabricated by drilling holes to the bottom of the coating and oxidizing the sample to create cavities in the carbon substrate underneath the coating as oxygen reacted with the carbon and resulted in its consumption. The cavities varied in diameter from approximately 1.4 to 3 mill (as measured optically). The sample was used as a standard to determine capabilities of state-of-the-art nondestructive evaluation (NDE) methods for detecting and sizing oxidation damage beneath a mostly intact coating in RCC. Both one and two-sided NDE methods are used. One-sided methods are practical for on-wing inspection, while two-sided methods might be applicable in situations where RCC panel removal is possible. Comparisons of diameter and depth obtained from NDE measurements with those from optically-measured void sizes are shown.
Funding Universal Service Obligations

One of the many challenges facing policy-makers is fostering competition in postal markets while, at the same time, preserving universal service. This is a difficult undertaking, for to declare the need for a universal service policy is to admit that the unsubsidized competitive marketplace will fail to deliver a politically acceptable level of service at a politically acceptable price. But, competition and subsidization are like oil and water; they can be mixed only with great care.
Fast Algorithms for the Maximum Clique Problem on Massive Graphs with Applications to Overlapping Community Detection

The maximum clique problem is a well-known NP-hard problem with applications in data mining, network analysis, information retrieval, and many other areas related to the World Wide Web. There exist several algorithms for the problem, with acceptable runtimes for certain classes of graphs, but many of them are infeasible for massive graphs. We present a new exact algorithm that employs novel pruning techniques and is able to find maximum cliques in very large, sparse graphs quickly. Extensive experiments on different kinds of synthetic and real-world graphs show that our new algorithm can be orders of magnitude faster than existing algorithms. We also present a heuristic that runs orders of magnitude faster than the exact algorithm while providing optimal or near-optimal solutions. We illustrate a simple application of the algorithms in developing methods for detection of overlapping communities in networks.
Cox's theorem revisited

The assumptions needed to prove Cox's Theorem are discussed and examined. Various sets of assumptions under which a Cox-style theorem can be proved are provided, although all are rather strong and, arguably, not natural.
Aspects in the progression of materials and processes for 256Mb-DRAM and beyond

It's has been the general opinion of device manufacturers that deep ultraviolet imaging will be the imaging method required to produce 250nm and sub-250nm geometries for 256Mb-DRAM's and related logic technology. Traditional Wine lithography may not capable of manufacturing at these geometries and the use of deep UV radiation with "chemically amplified" photoresists will be required for these device programs. Issues regarding the problems that researchers are combating or have not yet considered in the evolutionary chain of deep ultraviolet photoresist development and implementation will be discussed. As researchers continue developing environmentally stable materials, there is a series of issues that device manufacturers need to resolve today as new quarter micron fabs are currently under construction. Fab designers may need to consider additional space for specialty tools or processes in order to produce quarter micron lithography. The issues concerning materials, process, reflectivity control, manufacturing facilities, quality control, photoresist manufacturing, photoresist cost and a proposed roadmap for the next several years of development will be discussed. The author will also provide a brief overview of current Mine photoresists and their capability to the 300= geometry region along with some basic chemistry regarding the principles of DNQ's and chemically amplified photoresists.
Erosion and sedimentation.

1. Introduction to erosion and dedimentation 2. Physical properties and dimensional analysis 3. Mechanics of sediment-laden flows 4. Particle motion in inviscid fluids 5. Particle motion in Newtonian fluids 6. Turbulent velocity profiles 7. Incipient motion 8. Bedforms 9. Bedload 10. Suspended load 11. Total load 12. Reservoir sedimentation.
“Are You with Me?” – Using Accelerometers to Determine If Two Devices Are Carried by the Same Person

As the proliferation of pervasive and ubiquitous computing devices continues, users will carry more devices. Without the ability for these devices to unobtrusively interact with one another, the user’s attention will be spent on coordinating, rather than using, these devices. We present a method to determine if two devices are carried by the same person, by analyzing walking data recorded by low-cost MEMS accelerometers using the coherence function, a measure of linear correlation in the frequency domain. We also show that these low-cost sensors perform similarly to more expensive accelerometers for the frequency range of human motion, 0 to 10Hz. We also present results from a large test group illustrating the algorithm’s robustness and its ability to withstand real world time delays, crucial for wireless technologies like Bluetooth and 802.11. We present results that show that our technique is 100% accurate using a sliding window of 8 seconds of data when the devices are carried in the same location on the body, is tolerant to inter-device communication latencies, and requires little communication bandwidth. In addition we present results for when devices are carried on different parts of the body.
Theories of hydrophobic effects and the description of free volume in complex liquids

Recent progress on molecular theories of hydration of nonpolar solutes in liquid aqueous solution has lead to new ways to thinking about the old issue of free volume in liquids. This article surveys the principal new results with particular attention to the context of general issues of packing in liquids.
Poverty and the spatial distribution of rural population

According to global spatial data sets in 2000 more than one-third of the rural population in developing countries was located on less favored agricultural land and areas. Less favored agricultural lands are susceptible to low productivity and degradation, because their agricultural potential is constrained biophysically by terrain, poor soil quality, or limited rainfall. Less favored agricultural areas include less favored agricultural lands plus favorable agricultural land that is remote, that is, land in rural areas with high agricultural potential but with limited access. The paper presents tests of whether these spatial distributions of rural population influence poverty directly or indirectly via income growth in 83 developing countries from 2000 to 2012. The analysis finds no evidence of a direct impact on poverty, but there is a significant indirect impact via the elasticity of poverty reduction with respect to growth. Reducing poverty requires targeting rural populations in less favored lands and remote areas, in addition to encouraging out-migration in some areas.
Classical approximation schemes for the ground-state energy of quantum and classical ising spin hamiltonians on planar graphs

We describe a classical approximation algorithm for evaluating the ground state energy of the classical Ising Hamiltonian with linear terms on an arbitrary planar graph. The running time of the algorithm grows linearly with the number of spins and exponentially with 1/∈, where ∈ is the worst-case relative error. This result contrasts the well known fact that exact computation of the ground state energy for the two-dimensional Ising spin glass model is NP-hard. We also present a classical approximation algorithm for the quantum Local Hamiltonian Problem or Quantum Ising Spin Glass problem on a planar graph with bounded degree which is known to be a QMA-complete problem. Using a different technique we find a classical approximation algorithm for the quantum Ising spin glass problem on the simplest planar graph with unbounded degree, the star graph.
Evaluating Cartogram Effectiveness

Cartograms are maps in which areas of geographic regions, such as countries and states, appear in proportion to some variable of interest, such as population or income. Cartograms are popular visualizations for geo-referenced data that have been used for over a century to illustrate patterns and trends in the world around us. Despite the popularity of cartograms, and the large number of cartogram types, there are few studies evaluating the effectiveness of cartograms in conveying information. Based on a recent task taxonomy for cartograms, we evaluate four major types of cartograms: contiguous, non-contiguous, rectangular, and Dorling cartograms. We first evaluate the effectiveness of these cartogram types by quantitative performance analysis (time and error). Second, we collect qualitative data with an attitude study and by analyzing subjective preferences. Third, we compare the quantitative and qualitative results with the results of a metrics-based cartogram evaluation. Fourth, we analyze the results of our study in the context of cartography, geography, visual perception, and demography. Finally, we consider implications for design and possible improvements.
TESTING OF ACCELERATOR DIPOLES IN PRESSURIZED SUPERFLUID HELIUM

Two superconducting accelerator dipole magnets, with different internal construction features, have been tested in pressurized superfluid helium (1.8K, 1.2 atmosphere) as well as in regular pool boiling helium (4.4K, 1.2 atmosphere) helium. The coils of one magnet were moderately pre-stressed, and 4.2 K design performance was rapidly achieved in the superfluid. The other magnet had very low coil pre-stress, reduced helium ventilation, and displayed degraded performance, even in the superfluid helium.
Deterministic sampling-based motion planning: Optimality, complexity, and performance:

Probabilistic sampling-based algorithms, such as the probabilistic roadmap (PRM) and the rapidly-exploring random tree (RRT) algorithms, represent one of the most successful approaches to robotic motion planning, due to their strong theoretical properties (in terms of probabilistic completeness or even asymptotic optimality) and remarkable practical performance. Such algorithms are probabilistic in that they compute a path by connecting independent and identically distributed (i.i.d.) random points in the configuration space. Their randomization aspect, however, makes several tasks challenging, including certification for safety-critical applications and use of offline computation to improve real-time execution. Hence, an important open question is whether similar (or better) theoretical guarantees and practical performance could be obtained by considering deterministic, as opposed to random sampling sequences. The objective of this paper is to provide a rigorous answer to this question. The focus is on the PRM algorithm—our results, however, generalize to other batch-processing algorithms such as \(\text {FMT}^*\). Specifically, we first show that PRM, for a certain selection of tuning parameters and deterministic low-dispersion sampling sequences, is deterministically asymptotically optimal, i.e., it returns a path whose cost converges deterministically to the optimal one as the number of points goes to infinity. Second, we characterize the convergence rate, and we find that the factor of sub-optimality can be very explicitly upper-bounded in terms of the \(\ell _2\)-dispersion of the sampling sequence and the connection radius of PRM. Third, we show that an asymptotically optimal version of PRM exists with computational and space complexity arbitrarily close to O(n) (the theoretical lower bound), where n is the number of points in the sequence. This is in stark contrast to the \(O(n\, \log n)\) complexity results for existing asymptotically-optimal probabilistic planners. Finally, through numerical experiments, we show that planning with deterministic low-dispersion sampling generally provides superior performance in terms of path cost and success rate.
The Fundamental Surface of quad lenses

In a quadruply imaged lens system, the angular distribution of images around the lens centre is completely described by three relative angles. We show empirically that in the three-dimensional space of these angles, spanning 180°× 180°× 90°, quads from simple twofold symmetric lenses of arbitrary radial density profile and arbitrary radially dependent ellipticity or external shear define a nearly invariant two-dimensional surface. We give a fitting formula for the surface using the SIS+elliptical lensing potential. Various circularly symmetric mass distributions with shear up to γ∼ 0.4 deviate from it by typically an rmsof ∼01, while elliptical mass distributions with ellipticity of up to e∼ 0.4 deviate from it by rms ∼15. The existence of a near-invariant surface gives a new insight into the lensing theory and provides a framework for studying quads. It also allows one to gain information about the lens mass distribution from the image positions alone, without any recourse to mass modelling. As an illustration, we show that about 3/4 of observed galaxy-lens quads do not belong to this surface within observational error, and so require additional external shear or substructure to be modelled adequately.
On-line correction of in-pack processing of foods and validation of automated processes to improve product quality

Publisher Summary This chapter addresses the on-line correction of in-pack processing of foods, presenting a short review of the work done on batch retorts and a description of new developments on continuous retorts. The primary purpose of on-line correction of process temperature deviations is to automatically vary the process time to ensure that all containers receive the heat treatment necessary to achieve the required sterilization at the cold spot (the slowest heating point) of the food product. The critical part of the control system, specifically for batch retort operations, is to implement a fast method for accurately determining the new process time necessary to compensate for the process temperature deviations. In an on-line correction algorithm, the target process lethality is the most important constraint utilized to calculate the required new processing time. The traditional approach to evaluate the efficacy of a thermal process is based on the assumption that the inactivation of microbial cells and spores follows a first-order kinetic model. However, there is a growing concern about its validity because curvilinear isothermal survival curves are frequently observed. The Weibull model has been shown to be able to provide a more accurate estimation of microbial inactivation by heat and also by other inactivation sources: pressure and chemical agents. This model is of special interest to thermal processes of low-acid canned foods. Given the importance of non-linear kinetics in the evaluation of thermal processes, the chapter discusses on-line correction strategies for continuous retorts by using both first-order kinetics and the Weibull model.
EQUILIBRIUM DISTRIBUTION OF ZEROS OF RANDOM POLYNOMIALS

We consider ensembles of random polynomials of the form p(z) = P N=1 ajPj where {aj} are independent complex normal random variables and where {Pj} are the orthonormal polynomials on the boundary of a bounded simply connected analytic plane domain ⊂ C relative to an analytic weight �(z)|dz| . In the simplest case where is the unit disk and � = 1, so that Pj(z) = z j , it is known that the average distribution of zeros is the uniform measure on S 1 . We show that for any analytic (,�), the zeros of random polynomials almost surely become equidistributed relative to the equilibrium measure on @ as N → ∞. We further show that on the length scale of 1/N, the correlations have a universal scaling limit independent of (,�).
Searches for heavy exotic states at the Tevatron

We present the results of searches for Standard Model Higgs, charged stable massive particles, dijet mass resonances, and heavy neutral gauge bosons in Tevatron pp collisions at \(\sqrt s = 1.8TeV\) using the CDF and DO detectors.
Analogues of Vélu’s formulas for isogenies on alternate models of elliptic curves

Isogenies of elliptic curves have been well-studied, in part because there are several cryptographic applications. Using Velu’s formula, isogenies can be evaluated explicitly given their kernel. However, Velu’s formula applies to elliptic curves given by a Weierstrass equation. In this paper we show how to similarly evaluate isogenies on Edwards curves and Huff curves. Edwards and Huff curves are new normal forms for elliptic curves, different than the traditional Weierstrass form.
Rapid labor reallocation with a stagnant unemployment pool : the puzzle of the labor market in Lithuania

Lithuania is a transition economy undergoing rapid enterprise restructuring associated with substantial job turnover. At the same time, unemployment in Lithuania is high and of long duration. This presents a puzzle: high job turnover epitomizes labor market flexibility, while high unemployment indicates labor market rigidities. What are the reasons behind this paradox? Why do the unemployed not benefit from job opportunities created by high job turnover, which entails high rates of job creation and hiring? To answer this question, the author looks at three perspectives on labor market flexibility: 1) The macroeconomic perspective-A flexible labor market is one that facilitates full use and efficient allocation of labor resources. 2) The worker perspective-A flexible labor market means ease in finding a job paying a wage adequate to the worker's effort and skills. 3) The employer perspective-A flexible labor market does not unduly constrain the employer's ability to adjust employment and wages to changing market conditions. The author looks at all three dimensions of labor market flexibility by analyzing job reallocation, worker transitions across labor force states, wage distribution, and regulatory constraints faced by employers. He focuses on the issue of job creation and job destruction, using micro level data on all registered firms. He finds that flexibility in one dimension can concur with rigidities in the other. Specifically, employers in Lithuania have a substantial degree of flexibility with employment adjustment coupled with limited flexibility to wage adjustment due to a high statutory minimum wage. The relatively rigid wage structure locks low productivity workers who are preponderant among the unemployed. The low-skilled long-term unemployed have become marginalized and unable to successfully compete for available jobs, while the high job turnover is accounted for largely by job-to-job transitions. As a result, a dynamic labor market coincides with a stagnant unemployment pool.
On the evolution of the snow line in protoplanetary discs

We model the evolution of the snow line in a protoplanetary disc. If the magnetorotational instability (MRI) drives turbulence throughout the disc, there is a unique snow line outside of which the disc is icy. The snow line moves closer to the star as the infall accretion rate drops. Because the snow line moves inside the radius of the Earth’s orbit, the formation of our water-devoid planet is difficult with this model. However, protoplanetary discs are not likely to be sufficiently ionized to be fully turbulent. A dead zone at the mid-plane slows the flow of material through the disc and a steady state cannot be achieved. We therefore model the evolution of the snow line also in a time-dependent disc with a dead zone. As the mass is accumulating, the outer parts of the dead zone become self-gravitating, heat the massive disc and thus the outer snow line does not come inside the radius of the Earth’s orbit, contrary to the fully turbulent disc model. There is a second, inner icy region, within the dead zone, that moves inwards of the Earth’s orbit after a time of about 10 6 yr. With this model there is sufficient time and mass in the disc for the Earth to form from water-devoid planetesimals at a radius of 1 au. Furthermore, the additional inner icy region predicted by this model may allow for the formation of giant planets close to their host star without the need for much migration.
Likelihood robust optimization for data-driven problems

We consider optimal decision-making problems in an uncertain environment. In particular, we consider the case in which the distribution of the input is unknown, yet there is some historical data drawn from the distribution. In this paper, we propose a new type of distributionally robust optimization model called the likelihood robust optimization (LRO) model for this class of problems. In contrast to previous work on distributionally robust optimization that focuses on certain parameters (e.g., mean, variance, etc.) of the input distribution, we exploit the historical data and define the accessible distribution set to contain only those distributions that make the observed data achieve a certain level of likelihood. Then we formulate the targeting problem as one of optimizing the expected value of the objective function under the worst-case distribution in that set. Our model avoids the over-conservativeness of some prior robust approaches by ruling out unrealistic distributions while maintaining robustness of the solution for any statistically likely outcomes. We present statistical analyses of our model using Bayesian statistics and empirical likelihood theory. Specifically, we prove the asymptotic behavior of our distribution set and establish the relationship between our model and other distributionally robust models. To test the performance of our model, we apply it to the newsvendor problem and the portfolio selection problem. The test results show that the solutions of our model indeed have desirable performance.
SYNCHROTRON X-RAY MICROTOMOGRAPHY AND INTERFACIAL PARTITIONING TRACER TEST MEASUREMENTS OF NAPL-WATER INTERFACIAL AREAS.

Interfacial areas between an immiscible organic liquid (NAPL), and water were measured for two natural porous media using two methods, aqueous-phase interfacial partitioning tracer tests and synchrotron X-ray microtomography. The interfacial areas measured with the tracer tests were similar to previously reported values obtained with the method. The values were, however, significantly larger than those obtained from microtomography. Analysis of microtomography data collected before and after introduction of the interfacial tracer solution indicated that the surfactant tracer had minimal impact on fluid-phase configuration and interfacial areas under conditions associated with typical laboratory application. The disparity between the tracer test and microtomography values is attributed primarily to the inability of the microtomography method to resolve interfacial area associated with microscopic surface heterogeneity. This hypothesis is consistent with results recently reported for a comparison of microtomographic analysis and interfacial tracer tests conducted for an air-water system. The tracer test method provides a measure of effective, total (capillary and film) interfacial area, whereas microtomography can be used to determine separately both capillary-associated and film-associated interfacial areas. Both methods appear to provide useful information for given applications. A key to their effective use is recognizing the specific nature of the information provided by each,more » as well as associated limitations.« less
Hybrid processing of beliefs and constraints

This paper explores algorithms for processing probabilistic and deterministic information when the former is represented as a belief network and the latter as a set of boolean clauses. The motivating tasks are 1. evaluating belief networks having a large number of deterministic relationships and 2. evaluating probabilities of complex boolean queries or complex evidence information over a belief network. We present and analyze a variable elimination algorithm that exploits both types of information, and provide empirical evaluation demonstrating its computational benefits.
Coping with a Layoff: A Longitudinal Study of Victims

This article reports the results of a longitudinal study of layoff victims and how they cope with job loss. We examine whether the perceived fairness of layoff procedures, corporate and government assistance programs, and individual differences influence the choice of problem-focused and/or symptom-focused coping strategies. Our findings challenge traditionally held assumptions about factors that may be associated with successful coping. Specifically, perceptions of the fairness of layoff procedures and adequacy of government assistance programs were negatively related with problem-focused strategies used by layoff victims, and there was no relationship with corporate assistance programs and the choice of coping strategy. In addition, self-blame for the job loss was positively related to a symptom-focused strategy. Suggestions for future research on victims of layoffs are discussed.
Generalized quantum Fokker-Planck equation for photoinduced nonequilibrium processes with positive definiteness condition

This work provides a detailed derivation of a generalized quantum Fokker-Planck equation (GQFPE) appropriate for photo-induced quantum dynamical processes. The path integral method pioneered by Caldeira and Leggett (CL) [Physica A 121, 587 (1983)] is extended by utilizing a nonequilibrium influence functional applicable to different baths for the ground and the excited electronic states. Both nonequilibrium and non-Markovian effects are accounted for consistently by expanding the paths in the exponents of the influence functional up to the second order with respect to time. This procedure results in approximations involving only single time integrations for the exponents of the influence functional but with additional time dependent boundary terms that have been ignored in previous works. The boundary terms complicate the derivation of a time evolution equation but do not affect position dependent physical observables or the dynamics in the steady state limit. For an effective density operator with the boundary terms factored out, a time evolution equation is derived, through short time expansion of the effective action and Gaussian integration in analytically continued complex domain of space. This leads to a compact form of the GQFPE with time dependent kernels and additional terms, which renders the resulting equation to be in the Dekker form [Phys. Rep. 80, 1 (1981)]. Major terms of the equation are analyzed for the case of Ohmic spectral density with Drude cutoff, which shows that the new GQFPE satisfies the positive definiteness condition in medium to high temperature limit. Steady state limit of the GQFPE is shown to approach the well-known expression derived by CL in the high temperature and Markovian bath limit and also provides additional corrections due to quantum and non-Markovian effects of the bath.
CT of Primary and Secondary Craniocerebral Neuroblastoma

Eleven children with craniocerebral neuroblastoma (three primary and eight metastatic) were examined by computed tomography (CT). The findings in both primary and secondary neuroblastoma correlate well with the known neuropathologic findings. Primary cerebral neuroblastoma originates in the brain parenchyma of the supratentorial space, and may extend into the cerebrospinal fluid pathways. Secondary neuroblastoma is confined to the osseous structures of the calvarium and orbit, and adjacent subperiosteal spaces (epidural and epicranial). In both forms of neuroblastoma, intratumoral hemorrhage is frequent. Separation of the cranial sutures often relates to epidural deposits of tumor extending to the sutural margins. In this form of sutural diastasis, intracranial pressure is not elevated. When elevated intracranial pressure accompanies sutural diastatis, CT findings reveal epidural deposits compressing the major dural venous sinuses in the region of their confluence.
Interstellar Krypton Abundances: The Detection of Kiloparsec-scale Differences in Galactic Nucleosynthetic History*

We present an analysis of Kr I λ1236 line measurements from 50 sight lines in the Hubble Space Telescope Space Telescope Imaging Spectrograph and Goddard High Resolution Spectrograph data archives that have sufficiently high resolution and signal-to-noise ratio to permit reliable krypton-to-hydrogen abundance ratio determinations. The distribution of Kr/H ratios in this sample is consistent with a single value for the ISM within 5900 pc of the Sun, log10(Kr/H) = −9.02 ± 0.02, apart from a rough annulus from between ~600 and 2500 pc distant. The Kr/H ratio toward stars within this annulus is elevated by approximately 0.11 dex, similar to previously noted elevations of O/H and Cu/H gas-phase abundances beyond ~800 pc. A significant drop in the gas-phase N/O ratio in the same region suggests that this is an artifact of nucleosynthetic history. Since the physical scale of the annulus' inner edge is comparable to the radius of the Gould Belt and the outer limit of heliocentric distances where the D/H abundance ratio is highly variable, these phenomena may be related to the Gould Belt's origins.
The F-signature of an affine semigroup ring

Abstract We prove that the F-signature of an affine semigroup ring of positive characteristic is always a rational number, and describe a method for computing this number. We use this method to determine the F-signature of Segre products of polynomial rings, and of Veronese subrings of polynomial rings. Our technique involves expressing the F-signature of an affine semigroup ring as the difference of the Hilbert-Kunz multiplicities of two monomial ideals, and then using Watanabe's result that these Hilbert-Kunz multiplicities are rational numbers.
Interphase cytogenetics in mammographically detected breast lesions

Abstract Chromosomal aneuploidy in 25 mammographically detected breast lesions (MDBL) were determined on cytological smears using directly labeled pericentromeric probes for chromosomes 7 to 12, 17, 18, and X. The lesions included seven nonproliferative (NP) lesions, seven atypical hyperplasias (AHs), and 11 carcinomas (CAs). No other significant histological findings were identified in the remaining specimens except in two mammographically detected NP lesions, where foci of AH were present in adjacent sections; therefore, these two specimens were included in the AH lesion group (moderately increased risk lesions). Corresponding tissue sections were evaluated, and the results were correlated with fluorescent in situ hybridization (FISH) results. Monosomy was defined as the loss of one signal in ⩾ 15% of cells, and trisomy or tetrasomy was defined by the presence of three or more signals in ⩾ 3% of cells. Chromosomal aberrations were detected in 2 of 5 NP, 9 of 9 AH, and 11 of 11 CA groups. The mean number of cells with three or more signals, for all chromosomes, was 1.04 ± 0.9 in the NP group, 8.5 ± 9.4 in the AH group, and 20.2 ± 5.4 in the CAs. A significant statistical difference was noted between the different groups ( P = .0001). Chromo somal gain was the most common aberration and involved all chromosomes. The X chromosome was the only individual chromosome with significant differences in NP, AH, and CA groups. Chromosomal loss was observed in five specimens (20%) and involved chromosomes 8, 10, 17, and 18. The authors conclude (1) significant chromosomal aberrations can be detected in AH lesions and in NP epithelium from patients with moderately increased risk lesions; (2) numerical chromosomal aberrations tend to increase with progression of disease; (3) the frequent chromosomal gains/losses involving AH suggest that some AH may display submicroscopic features of malignancy; and (4) combined chromosomal aberrations allow for significant categorization of breast lesions, especially in cytology specimens.
Dynamic scaling function at the quasiperiodic transition to chaos

Abstract We obtain a five-step approximation to the quasiperiodic dynamic scaling function for experimental Rayleigh-Benard convection data. When errors are taken into account in the experiment, the f(α) spectrum of scalings is equivalent to just two of these five scales. To overcome this limitation, we develop a robust technique for extracting the scaling function from experimental data by reconstructing the dynamics of the experiment.
Temporal response of atmospheric turbulence compensation

The temporal kernel for the phase error variance due to atmospheric turbulence is calculated. This kernel, convolved with the servo transfer function, determines the temporal error of any turbulence compensation scheme.
Model studies of lantibiotic biogenesis

Abstract A six residue polypeptide has been synthesized to study the proposed biosynthesis of lanthionine. It is shown that this peptide spontaneously cyclizes in a biomimetic fashion via a completely stereoselective intramolecular Michael addition to form (2s, 6R)-lanthionine, as found in naturally occurring lantibiotics.
Asymmetric Risk Measures and Real Estate Returns

Rational investors distinguish between extremely high and extremely low returns. The measures of investment risk should reflect such asymmetric risk perception. This study presents six asymmetric risk metrics and empirically tests their abilities in explaining the cross-sectional variations of real estate returns. It finds strong evidence that systematic downside risk is associated with a risk premium, and skewness provides significant explanatory power to the variation of cross-sectional property returns. On the other hand, co-skewness does not explain real estate returns well and is not a good systematic risk measure.
Generalization of the Coddington equations to include hybrid diffractive surfaces

Coddington Equations are used to calculate the astigmatic images of a small bundle of rays centered on a ray commonly known as the principal ray. Some authors generalize it such that for a refractive or reflective surface of any shape to the 2nd order, and an incident wavefront of any shape to the 2nd order, the refracted or reflected wavefront can be calculated to the 2nd order. We extend it further such that it applies to the diffractive surface as well. The derivation is based on the general Snell's law and differential ray tracing approach. We present these generalized Coddington Equations in two forms: matrix formalism and explicit expressions. The equations are verified with explicit ray tracing using a commercial lens design program. The relations are applied to evaluate the imaging performance for null testing of aspheric surfaces using computer generated holograms.
Recent advances in the API quality program

The API now has more than 3 years' operating experience in licensing manufacturers under the API Quality Program. The API evaluation procedures, described in this paper, provide consistency in evaluation and should allow full participation of petroleum equipment suppliers in the worldwide market during the 1990's and into the 21st century. The program's flexibility will allow it to cope with significant changes resulting from the planned European Common Market's Global Approach to Certification and Testing scheduled to occur in 1992.
Rural Amenity Values and Length of Residency

New residents of rural communities are often assumed to have preferences for development and conservation that differ from those of longer-term residents. However, the literature offers little to quantify presumed preference heterogeneity. This article assesses whether stated preferences differ according to length of residency. Results are based on a conjoint (choice experiment) survey of Rhode Island rural residents. Heterogeneity—according to length of town residency—is modeled using dummy variables, multiplicative interactions, and Lagrangian interpolation polynomials. Results are compared across the three models, and identify a range of attributes for which willingness to pay depends on length of residency.
Thermonuclear Operation Space Lift

The “Project Orion” small fission bomb propulsion concept proposed the one-stage launching of large payloads into low Earth orbit, but it was abandoned because of the radioactive fallout into Earth’s atmosphere. The idea is here revived by the replacement of the small fission bombs with pure deuterium–tritium fusion bombs, and the pusher plate of Project Orion with a large magnetic mirror. The ignition of the thermonuclear fusion reaction is done by the transient formation of keV super-explosives under the high pressure of a convergent shock wave launched into liquid hydrogen propellant by a conventional high explosive.
Hierarchy of gene expression data is predictive of future breast cancer outcome

We calculate measures of hierarchy in gene and tissue networks of breast cancer patients. We find that the likelihood of metastasis in the future is correlated with increased values of network hierarchy for expression networks of cancer-associated genes, due to the correlated expression of cancer-specific pathways. Conversely, future metastasis and quick relapse times are negatively correlated with the values of network hierarchy in the expression network of all genes, due to the dedifferentiation of gene pathways and circuits. These results suggest that the hierarchy of gene expression may be useful as an additional biomarker for breast cancer prognosis.
Optimal currency crises

Abstract Flawed government policies have been offered as an explanation for currency crises in most of the previous literature. With few exceptions, the role of the banking system is ignored. Empirical evidence suggests that in recent decades banking crises and currency crises have been linked. A model is developed here where the “twin” crises result from low asset returns. Large movements in exchange rates are desirable to the extent that they allow better risk-sharing between a country's bank depositors and the international bond market. The rationale for using short-term debt denominated in a foreign reserve currency is also investigated.
Optimal disturbances in compressible boundary layers

The problem of transient growth in compressible boundary layers is considered within the scope of partial differential equations including the nonparallel flow effects. As follows from previous investigations, the optimal disturbances correspond to steady counter-rotating streamwise vortices. The corresponding scaling of the perturbations leads to the governing equations for a Gortler-type of instability, with the Gortler number equal to zero. The iteration procedure employs back and forth marching solutions of the adjoint and original systems of equations
An experimental investigation of the theory of electrostatic deflections

The so-called “pull-in” instability is a ubiquitous feature of electrostatic actuation. In systems where an applied voltage is used to actuate or move mechanical components, it is observed that when the applied voltage exceeds a critical value, electrostatic forces become dominant over elastic forces and the mechanical components “pull-in” or collapse into one another. Here, key theoretical results concerning this instability are surveyed and compared to a new experimental study of electrostatic deflections. Gaps between theory and experiment are uncovered and directions for future modeling and analysis indicated.
PHOTOSPHERIC SIGNATURES OF GRANULAR-SCALE FLUX EMERGENCE AND CANCELLATION AT THE PENUMBRAL BOUNDARY

We studied flux emergence events of sub-granular scale in a solar active region. The New Solar Telescope (NST) of the Big Bear Solar Observatory made it possible to clearly observe the photospheric signature of flux emergence with very high spatial (0.''11 at 7057 A) and temporal (15 s) resolution. From TiO observations with the pixel scale of 0.''0375, we found several elongated granule-like features (GLFs) stretching from the penumbral filaments of a sunspot at a relatively high speed of over 4 km s{sup -1}. After a slender arched darkening appeared at the tip of a penumbral filament, a bright point (BP) developed and quickly moved away from the filament, forming and stretching a GLF. The size of a GLF was approximately 0.''5 wide and 3'' long. The moving BP encountered nearby structures after several minutes of stretching, and the well-defined elongated shape of the GLF faded away. Magnetograms from the Solar Dynamics Observatory/Helioseismic and Magnetic Imager and NST/InfraRed Imaging Magnetograph revealed that those GLFs are photospheric indicators of small-scale flux emergence, and their disappearance is related to magnetic cancellation. From two well-observed events, we describe detailed development of the sub-structures of GLFs and different cancellation processes that each of themore » two GLFs underwent.« less
Predicting software reliability with neural network ensembles

Software reliability is an important factor for quantitatively characterizing software quality and estimating the duration of software testing period. Traditional parametric software reliability growth models (SRGMs) such as nonhomogeneous Poisson process (NHPP) models have been successfully utilized in practical software reliability engineering. However, no single such parametric model can obtain accurate prediction for all cases. In addition to the parametric models, non-parametric models like neural network have shown to be effective alternative techniques for software reliability prediction. In this paper, we propose a non-parametric software reliability prediction system based on neural network ensembles. The effects of system architecture on the performance are investigated. The comparative studies between the proposed system with the single neural network based system and three parametric NHPP models are carried out. The experimental results demonstrate that the system predictability can be significantly improved by combing multiple neural networks.
Homogeneity of Gd-based garnet transparent ceramic scintillators for gamma spectroscopy

Abstract Transparent polycrystalline ceramic scintillators based on the composition Gd 1.49 Y 1.49 Ce 0.02 Ga 2.2 Al 2.8 O 12 are being developed for gamma spectroscopy detectors. Scintillator light yield and energy resolution depend on the details of various processing steps, including powder calcination, green body formation, and sintering atmosphere. We have found that gallium sublimation during vacuum sintering creates compositional gradients in the ceramic and can degrade the energy resolution. While sintering in oxygen produces ceramics with uniform composition and little afterglow, light yields are reduced, compared to vacuum sintering. By controlling the atmosphere during the various process steps, we were able to minimize the gallium sublimation, resulting in a more homogeneous composition and improved gamma spectroscopy performance.
Impact of Epidural Failures on the Results of a Prospective, Randomized Trial.

Introduction We conducted a prospective randomized trial to evaluate the merits of two established postoperative pain management strategies: thoracic epidural (EPI) versus patient-controlled analgesia (PCA) with intravenous narcotics after minimally invasive repair of pectus excavatum. Pain scores favored the EPI group for the first two postoperative days only. Critics of the trial suggest that if the epidural failure rate was not so high, results may have favored the EPI group. Therefore, we performed a subset analysis of the EPI group to evaluate the impact of these failures. Methods Patients for whom epidural catheter could not be placed or whose catheters were removed early owing to dysfunction were compared with those with well-functioning catheters. Those with well-functioning catheters were also compared with the PCA group. A two-tailed independent Student t-test and a two-tailed Fisher exact test were used where appropriate. Results Of 55 patients in the EPI group, 12 patients (21.8%) had failed placement or required early removal. Comparing those with failed placements with the rest of the group, there was no difference in daily visual analogue scale pain scores or measures of hospital course. Likewise, comparing those with well-functioning catheters only to those in the PCA group, the results of the trial are replicated in terms of pain scores, hospital course, and length of stay. Conclusion In patients with failed epidural therapy, there is no significant difference in postoperative hospital course. Comparing those with well-functioning catheters to those in the PCA group, trial results are replicated—that is, no significant difference in length of stay, time to regular diet, or time to transition to oral medications. Therefore, failure rate in the EPI group did not influence the results of the trial.