cssi/SciSciGPT-SciSciNet huggingface dataset:
Transformer Computer Design Aid for Higher Frequency Switching Power Supplies

A transformer computer design aid is presented that was developed for use at switching frequencies above 100 kHz where the classical method of using the saturation constraint results in an over-heated transformer due to excessive core loss. Flux density is selected instead by an optimization procedure that minimizes total transformer losses. Key equations used in the design procedure are developed. Emphasis is placed on the algorithm used in the transformer design procedure.
Action potential duration restitution and ventricular fibrillation due to rapid focal excitation

The focal source hypothesis of ventricular fibrillation (VF) posits that rapid activation from a focal source, rather than action potential duration (APD) restitution properties, is responsible for...
Adaptive fuzzy temperature control for hydronic heating systems

In a hydronic heating system, a boiler heats hot water that is pumped through pipes to radiators throughout the dwelling. This article describes an alternative to a traditional PI algorithm for hydronic heating system control. The control algorithm described is an adaptive fuzzy control (AFC) algorithm. It compactly combines a unique adaptation algorithm that automatically learns the steady-state radiator valve positions for different operating set points with a simple rule-based fuzzy controller. Laboratory test results comparing the performance of the AFC with a variable-gain PI algorithm demonstrate that the AFC combines better temperature control with dramatically reduced battery consumption.
Novel fragmentation of 3-lithio-3,6-dihydro-1,2-oxazines : synthesis of 2,5-dihydro-2-furanylamines

Abstract N-Cbz or N-Boc protected 3,6-dihydro-1,2-oxazines 1 on treatment with LDA at −78°C undergo a novel rearrangement to provide synthetically useful N-Cbz or N-Boc protected dihydro-2-furanylamines 2.
Unemployment insurance in a sticky-price model with worker moral hazard

Abstract This paper studies the role of unemployment insurance in a sticky-price model that features an efficiency-wage view of the labor market based on unobservable effort. The risk-sharing mechanism central to the model permits, but does not force, agents to be fully insured. Structural parameters are estimated using a maximum-likelihood procedure on US data. Formal hypothesis tests reveal that the data favor a model in which agents only partially insure each other against employment risk. The results also show that limited risk sharing helps the model capture many salient properties of the business cycle that a restricted version with full insurance fails to explain.
Cyclocarboamination of Alkynes with Aziridines: Synthesis of 2,3-Dihydropyrroles by a Catalyzed Formal [3 + 2] Cycloaddition

An efficient cyclocarboamination reaction of nonactivated alkynes with aziridines, catalyzed by Lewis or Bronsted acids, to form 2,3-dihydropyrroles through a formal [3+2] cycloaddition, is described. The reaction provides a wide range of polysubstituted dihydropyrroles in a highly regioselective manner, is scalable, proceeds under mild reaction conditions, and uses low catalyst loadings.
Systems of conservation laws

Abstract : In this paper a wide class of difference equations is described for approximating discontinuous time dependent solutions, with prescribed initial data, of hyperbolic systems of nonlinear conservation laws. Among these schemes we determine the best ones, i.e., those which have the smallest truncation error and in which the discontinuities are confined to a narrow band of 2-3 meshpoints. These schemes are tested for stability and are found to be stable under a mild strengthening of the Courant-Friedrichs-Levy criterion. Test calculations of one dimensional flows of compressible fluids with shocks, rarefaction waves and contact discontinuities show excellent agreement with exact solutions. In particular, when Lagrange coordinates are used, there is no smearing of interfaces. The additional terms introduced into the difference scheme for the purpose of keeping the shock transition narrow are similar to, although not identical with, the artificial viscosity terms, and the like of them introduced by Richtmyer and von Neumann and elaborated by other workers in this field.
Design and Use of Fault Simulation for Saturn Computer Design

A system of IBM 7090 Data Processing System computer programs was developed for the purpose of normal and/or fault simulation of the Saturn computer. This paper will describe the design of the simulator and cite several applications in the development of the Saturn computer. The architecture, plus several important characteristics of the simulator, are presented. These include the Design Automation input interface, the logic selection procedure, failure injection, the compilation procedure, logical simulation and functional simulation. The ability to simulate up to 4000 Saturn instructions in either normal and/or fault environments (up to 33 faults per IBM 7090 run) will be demonstrated. Simulation of single, multiple, solid or intermittent faults, plus an automated statistical analysis of intermittent fault simulation results, will be presented. The IBM 7090 execution time of a compiled logic simulator can be prohibitive. To minimize running time several programming techniques were utilized, including logic block ordering (to allow single pass simulation), parallel fault simulation, stimulus bypassing, and functional simulation. These techniques are described. Several special forms of simulator output were developed. The use of this output and the applications of the simulator are presented, including design verfication, test program evaluation, generation of a test point catalog, disagreement detector network evaluation, disagreement detector placement, intermittent failure analysis.
Dynamics of one-dimensional self-gravitating systems using Hermite–Legendre polynomials

The current paradigm for understanding galaxy formation in the universe depends on the existence of self-gravitating collisionless dark matter. Modeling such dark matter systems has been a major focus of astrophysicists, with much of that effort directed at computational techniques. Not surprisingly, a comprehensive understanding of the evolution of these self-gravitating systems still eludes us, since it involves the collective nonlinear dynamics of many-particle systems interacting via long-range forces described by the Vlasov equation. As a step towards developing a clearer picture of collisionless self-gravitating relaxation, we analyze the linearized dynamics of isolated one-dimensional systems near thermal equilibrium by expanding their phase space distribution functions f(x,v) in terms of Hermite functions in the velocity variable, and Legendre functions involving the position variable. This approach produces a picture of phase-space evolution in terms of expansion coefficients, rather than spatial and velocity variables. We obtain equations of motion for the expansion coefficients for both test-particle distributions and self-gravitating linear perturbations of thermal equilibrium. N-body simulations of perturbed equilibria are performed and found to be in excellent agreement with the expansion coefficient approach over a time duration that depends on the size of the expansion series used.
A single model of traversable wormholes supported by generalized phantom energy or Chaplygin gas

This paper discusses a new variable equation of state parameter leading to exact solutions of the Einstein field equations describing traversable wormholes. In addition to generalizing the notion of phantom energy, the equation of state generates a mathematical model that combines the generalized phantom energy and the generalized Chaplygin gas models.
HETEROGENEITY IN THE EFFECT OF REGULATION ON ENTREPRENEURSHIP AND ENTRY SIZE

We use cross-national harmonized micro data from a broad sample of developed and developing countries and investigate the heterogeneity of the effect of entry, contract enforcement regulation, and financial development on both the decision to become an entrepreneur and the level of employment of newly created businesses. We focus on the interaction between the level of regulation and financial development and some individual characteristics that are important determinants of entrepreneurship, such as gender, business skills, and social networks. We find that entry regulation moderates the effect of business skills, while accentuating the effect of gender, even after accounting for the level of financial development. Specifically, women are more likely to enter into entrepreneurship in countries with higher levels of entry regulation, but mainly because they cannot find better work. This effect is also more pronounced in countries that are less financially developed. Furthermore, individuals who report having business skills are less likely to enter entrepreneurship in countries with higher entry regulation. Finally, we also find that individuals who know other entrepreneurs are less likely to start large businesses in countries with higher levels of entry and contract enforcement regulation. (JEL: K23, L26, L51)
Survey of various Z-domain to S-domain transformations

The basic objective of this paper is to study the unity in diversity of the various z-domaia to s-domain transformations and find under what conditions they yield similar results. The various transformations include impulse invariant, step invariant, bilinear transformation, ramp invariant transformations, and so on. The second objective is to find out under what conditions the continuous differential equation describing the system may be approximated by a difference equation for all the various z-domaia transformations. The third objective is to find out under what assumptions the discrete version of the impulse response becomes a sampled version of the continuous response. Finally, numerical results are presented to study the degree of accuracy of various approximations as a function of the sampling rate.
The Episodic, Precessing Giant Molecular Outflow from IRAS 04239+2436 (HH 300)

We present the first set of detailed molecular-line maps of the region associated with the giant Herbig-Haro flow HH 300 from the young star IRAS 04239+2436. Our results indicate that the red lobe of the HH 300 flow is depositing a fair amount of momentum [3.2(sin i)-1 M☉ km s-1] and kinetic energy [2.6(sin i)-2 × 1043 ergs] over a notable volume (~11%) of its host dark cloud. This makes HH 300 a key player in the evolution and fate of its parent cloud. The redshifted molecular outflow lobe of HH 300 is 1.1 pc long and 0.3 pc wide and has a very clumpy structure. The density, velocity, and momentum distributions in the outflow indicate that the observed clumps arise from the prompt entrainment of ambient gas. Bow shock-shaped structures are associated with the clumps, and we hypothesize that the shocks are produced by different mass ejection episodes. Lines drawn from IRAS 04239+2436 to each of these clumps have different orientations on the plane of the sky, and we conclude that HH 300 is a precessing and episodic outflow. The observations include a map of the red lobe in the CO (2-1) line, with a beam size of 27'', and more extended maps of the outflow region in the 12CO (1-0) and 13CO (1-0) lines, with 45'' and 47'' beam sizes, respectively. Due to "contamination" by emission from another molecular cloud along the same line of sight, we are not able to study the blueshifted lobe of HH 300. The combined 12CO (1-0) and 13CO (1-0) line observations enable us to estimate the outflow mass accounting for the velocity-dependent opacity of the 12CO (1-0) line. This method is much more precise than using 12CO data alone. We obtain a steep power-law mass spectrum for HH 300, which we believe is best explained by the evolution of the outflow mass kinematics. In addition, our 13CO (1-0) observations show that the HH 300 flow has been able to redistribute (in space and velocity) considerable amounts of its surrounding medium-density (~103 cm-3) gas.
CAN THE SOLAR WIND BE DRIVEN BY MAGNETIC RECONNECTION IN THE SUN'S MAGNETIC CARPET?

The physical processes that heat the solar corona and accelerate the solar wind remain unknown after many years of study. Some have suggested that the wind is driven by waves and turbulence in open magnetic flux tubes, and others have suggested that plasma is injected into the open tubes by magnetic reconnection with closed loops. In order to test the latter idea, we developed Monte Carlo simulations of the photospheric "magnetic carpet" and extrapolated the time-varying coronal field. These models were constructed for a range of different magnetic flux imbalance ratios. Completely balanced models represent quiet regions on the Sun and source regions of slow solar wind streams. Highly imbalanced models represent coronal holes and source regions of fast wind streams. The models agree with observed emergence rates, surface flux densities, and number distributions of magnetic elements. Despite having no imposed supergranular motions in the models, a realistic network of magnetic "funnels" appeared spontaneously. We computed the rate at which closed field lines open up (i.e., recycling times for open flux), and we estimated the energy flux released in reconnection events involving the opening up of closed flux tubes. For quiet regions and mixed-polarity coronal holes, these energy fluxes were found to be much lower than that which is required to accelerate the solar wind. For the most imbalanced coronal holes, the energy fluxes may be large enough to power the solar wind, but the recycling times are far longer than the time it takes the solar wind to accelerate into the low corona. Thus, it is unlikely that either the slow or fast solar wind is driven by reconnection and loop-opening processes in the magnetic carpet.
Completely positive maps and classical correlations

We expand the set of initial states of a system and its environment that are known to guarantee completely positive reduced dynamics for the system when the combined state evolves unitarily. We characterize the correlations in the initial state in terms of its quantum discord [1]. We prove that initial states that have only classical correlations lead to completely positive reduced dynamics. The induced maps can be not completely positive when quantum correlations including, but not limited to, entanglement are present.
A Conceptual Framework for Assessing Climate-Related Heat Effects on Craft Time Utilization in the Construction Industry

The nature of construction jobs often exposes construction workers to hot weather conditions. Incidence of extreme weather events is rising with climate-related changes observed globally and in the United States. Heat illness prevention strategies have unknown impacts on craft time utilization in the construction industry. A new approach, which relies on the integration of worker physiology models, sampling methods, thermal comfort theories, and meteorological knowledge, is employed in this research to develop a framework for assessing climate-related heat effects on craft time utilization. The findings of this research will provide great implications for increasing the productivity and sustainability of U.S. construction workforce.
Gas production potential of disperse low-saturation hydrate accumulations in oceanic sediments

In this paper we evaluate the gas production potential ofdisperse, low-saturation (SH<0.1) hydrate accumulations in oceanicsediments. Such hydrate-bearing sediments constitute a significantportion of the global hydrate inventory. Using numerical simulation, weestimate (a) the rates of gas production and gas release from hydratedissociation, (b) the corresponding cumulative volumes of released andproduced gas, as well as (c) the water production rate and the mass ofproduced water from disperse, low-SH hydrate-bearing sediments subject todepressurization-induced dissociation over a 10-year production period.We investigate the sensitivity of items (a) to (c) to the followinghydraulic properties, reservoir conditions, and operational parameters:intrinsic permeability, porosity, pressure, temperature, hydratesaturation, and constant pressure at which the production well is kept.The results of this study indicate that, despite wide variations in theaforementioned parameters (covering the entire spectrum of suchdeposits), gas production is very limited, never exceeding a few thousandcubic meters of gas during the 10-year production period. Such lowproduction volumes are orders of magnitude below commonly acceptedstandards of economic viability, and are further burdened with veryunfavorable gas-to-water ratios. The unequivocal conclusion from thisstudy is that disperse, low-SH hydrate accumulations in oceanic sedimentsare not promising targets for gas production by means ofdepressurization-induced dissociation, and resources for early hydrateexploitation should be focused elsewhere.
The stochastic dynamic product cycling problem

Abstract This paper studies the stochastic version of the dynamic, discrete period product cycling problem, in which several products are to be sequenced one at a time, on a single machine, to meet time-varying stochastic demands. The demand distribution for each product in each period is taken to be known, and there are variable costs incurred for holding inventory between periods, for backorders, and for production. At each changeover, fixed costs are incurred and production time is lost. All these costs can be dynamic. The problem is formulated as a multiperiod, dynamic program. A ‘restricted’ Lagrangean method is used to develop three alternative decompositions. One of these is used to investigate bounds and heuristic solutions. Preliminary numerical results on small problems are presented.
Orbifold genera, product formulas and power operations

We generalize the definition of orbifold elliptic genus and introduce orbifold genera of chromatic level h, using h-tuples rather than pairs of commuting elements. We show that our genera are in fact orbifold invariants, and we prove integrality results for them. If the genus arises from an H8-map into the Morava?Lubin?Tate theory Eh, then we give a formula expressing the orbifold genus of the symmetric powers of a stably almost complex manifold M in terms of the genus of M itself. Our formula is the p-typical analogue of the Dijkgraaf?Moore?Verlinde?Verlinde formula for the orbifold elliptic genus [R. Dijkgraaf et al., Elliptic genera of symmetric products and second quantized strings Comm. Math. Phys. 185(1) (1997) 197?209]. It depends only on h and not on the genus.
Governance and Performance Changes after Accusations of Corporate Fraud

Using a sample of companies charged with government, financial reporting, or stakeholder fraud or regulatory violation in the United States during the 1978–2001 period, this study found that after the accusation of fraud, companies increased the proportion of outsider directors on their boards of directors and on the monitoring committees of the boards. Furthermore, the results show comparable long-run stock price and operating performance between companies charged with fraud and a matching sample of companies not accused of fraud. Collectively, these results suggest that improvements in internal control systems following accusations of fraud help repair a company’s damaged reputation and reinstate confidence in the company.
Two‐Photon Fluorescent Probes for Bioimaging

With the extensive use of two-photon fluorescence microscopy (2PFM) in the biomedical field, the need for development of fluorescent probes with improved two-photon fluorescence (2PF) properties has triggered extensive studies in the synthesis of new probes that undergo efficient two-photon absorption (2PA). In order to provide a more comprehensive comparison of fluorophores for 2PF bioimaging, a figure of merit (FM) was developed by normalizing the 2PA action cross-section, a commonly used parameter for characterizing bioimaging 2PF probes, by the photodecomposition quantum yield. Another important aspect of developing 2PA fluorophores is hydrophilicity. Although hydrophilic fluorophores are generally preferred in 2PFM bioimaging, hydrophobic fluorophores are typically easier to synthesize and purify, and have been used successfully in 2PFM bioimaging. The methodologies of dispersing hydrophobic fluorophores into aqueous media, such as in a DMSO/water mixture, micelles, silica nanoparticles, or forming polymer nanoparticles, are reviewed. The design and synthesis of hydrophilic 2PA fluorophores, achieved by introducing polyethylene glycol (PEG), anionic acid groups, cationic ammonium salt, and PAMAM dendrimers, is presented. Introduction of specificity to target certain biomarkers via labeling of antibodies, DNA, smallbioactive molecules, and peptides, and for the sensing of sepcific cations and pH, is also reviewed.
Memory units in the Lincoln TX-2

There are 3 high-speed live memories in TX-2; all are random access and all use ferrite cores. The largest is the 6 1/2-μsec cycle time "S" memory with 65,536 37-digit words. The "T" memory is entirely transistor driven; it has a capacity of 4096 37-digit words and a 5 1/2-μsec cycle time. The smallest and fastest is the "X" memory with a capacity of 64 19-digit words; external word selection and 2 cores per bit make possible an access time of 0.8 μsec and a cycle time of 4 μsec.
A static cost analysis for a higher-order language

We develop a static complexity analysis for a higher-order functional language with structural list recursion. The complexity of an expression is a pair consisting of a cost and a potential. The former is defined to be the size of the expression's evaluation derivation in a standard big-step operational semantics. The latter is a measure of the "future" cost of using the value of that expression. A translation function {.} maps target expressions to complexities. Our main result is the following Soundness Theorem: If {t} is a term in the target language, then the cost component of {t} is an upper bound on the cost of evaluating t. The proof of the Soundness Theorem is formalized in Coq, providing certified upper bounds on the cost of any expression in the target language.
An Extension of the Trade Restrictiveness Index to Large Economies

The Trade Restrictiveness Index (TRI) introduced by Anderson and Neary (1994) provided the first theoretically satisfying measure of a country’s tariff structure by overcoming the problem of ad hoc specification of indexing weights and the related index number problem. We observe, however, that the TRI may not exist or may not be unique when countries are large. As a remedy, we propose a simple extension.
Component groups of unipotent centralizers in good characteristic

Abstract Let G be a connected, reductive group over an algebraically closed field of good characteristic. For u ∈ G unipotent, we describe the conjugacy classes in the component group A ( u ) of the centralizer of u . Our results extend work of the second author done for simple, adjoint G over the complex numbers. When G is simple and adjoint, the previous work of the second author makes our description combinatorial and explicit; moreover, it turns out that knowledge of the conjugacy classes suffices to determine the group structure of A ( u ). Thus we obtain the result, previously known through case-checking, that the structure of the component group A ( u ) is independent of good characteristic.
Reflections on Corporate Moral Responsibility and the Problem Solving Technique of Alexander the Great

The academic debate over the propriety of attributing moral responsibility to corporations is decades old and ongoing. The conventional approach to this debate is to identify the sufficient conditions for moral agency and then attempt to determine whether corporations possess them. This article recommends abandoning the conventional approach in favor of an examination of the practical consequences of corporate moral responsibility. The article’s thesis is that such an examination reveals that attributing moral responsibility to corporations is ethically acceptable only if it does not authorize the punishment of corporations as collective entities, and further, that this renders the debate over corporate moral responsibility virtually pointless.
Paramodular cusp forms

We classify Siegel modular cusp forms of weight two for the paramodular group K(p) for primes p< 600. We find that weight two Hecke eigenforms beyond the Gritsenko lifts correspond to certain abelian varieties defined over the rationals of conductor p. The arithmetic classification is in a companion article by A. Brumer and K. Kramer. The Paramodular Conjecture, supported by these computations and consistent with the Langlands philosophy and the work of H. Yoshida, is a partial extension to degree 2 of the Shimura-Taniyama Conjecture. These nonlift Hecke eigenforms share Euler factors with the corresponding abelian variety $A$ and satisfy congruences modulo \ell with Gritsenko lifts, whenever $A$ has rational \ell-torsion.
Unscented Filtering for Spacecraft Attitude Estimation

A new spacecraft attitude estimation approach based on the unscented filter is derived. For nonlinear systems the unscented filter uses a carefully selected set of sample points to map the probability distribution more accurately than the linearization of the standard extended Kalman filter, leading to faster convergence from inaccurate initial conditions in attitude estimation problems. The filter formulation is based on standard attitude-vector measurements using a gyro-based model for attitude propagation. The global attitude parameterization is given by a quaternion, whereas a generalized three-dimensional attitude representation is used to define the local attitude error. A multiplicative quaternion-error approach is derived from the local attitude error, which guarantees that quaternion normalization is maintained in the filter. Simulation results indicate that the unscented filter is more robust than the extended Kalman filter under realistic initial attitude-error conditions.
Modular, portable, and easily simulated ESD protection networks for advanced CMOS technologies

Abstract This paper introduces a new distributed active MOSFET rail clamp network that offers surprising advantages in layout area efficiency, bus resistance tolerance, design modularity, and ease of reuse. SPICE simulation results using an extended vertical PNP bipolar transistor compact model and a new method for optimizing distributed rail clamp networks are presented along with chip-level test results.
A Construction of Critical GJMS Operators Using Wodzicki's Residue

For an even dimensional, compact, conformal manifold without boundary we construct a conformally invariant differential operator of order the dimension of the manifold. In the conformally flat case, this operator coincides with the critical GJMS operator of Graham-Jenne-Mason-Sparling. We use the Wodzicki residue of a pseudo-differential operator of order −2, originally defined by A. Connes, acting on middle dimension forms.
Outlet types and the Canadian Consumer Price Index

Recent phenomenal growth in popularity of large warehouse/discount stores has important implications for price measurement. Consumer substitution to such outlets could produce a bias in consumer price indexes (CPIs), which may be exacerbated by unrepresentative sampling and discount outlets’ apparent slower rates of price increases. It is shown that in 1990-96 unit value indexes rose at a lower rate than the corresponding Canadian CPI subaggregate indexes for other household equipment, non-prescribed medicines, and audio equipment, and biases arising from unrepresentative sampling and differential rates of price increases across outlets have resulted in an additional overstatement for these subaggregates. La croissance dans la popularite des magasins/entrepots a forts escomptes au cours des der;chnieres annees a ete fort importante et a eu des effets importants sur la mesure des prix. Le comportement du consommateur qui choisit ces magasins pourrait entrainer un biais dans la mesure des indices de prix a la consommation. Un echantillonage non representatif et le fait que ces magasins semblent avoir des augmentations de prix plus faibles dans le temps peuvent biaiser encore plus les indices. Cette recherche montre que entre 1990 et 1996 les indices de la valeur unitaire ont cru a un taux plus faible que les indices correspondant de prix a la consommation pour des sous-agregats comme autre ´equipement des menages, medicaments non-prescrit, et ´equipement audio. Il semble que les biais engendres par les differentiels de croissance des prix entre magasins et un echantillonnage non representatif se soient traduits par un biais a la hausse dans ces sous-agregats
Selective, catalytic carbon-carbon bond activation and functionalization promoted by late transition metal catalysts.

The selective catalytic activation and functionalization of carbon−carbon bonds in a series of substituted cyclopropane substrates has been developed using commercially available transition metal catalysts. Catalytic hydrogenation and olefination procedures, tolerant of a range of functional groups, have been discovered. Introduction of a chelate-assisting substituent such as [PPh2] is effective in altering the kinetic selectivity and lowering the activation barrier for the catalytic processes.
Variables Associated with the Early Failure of Nasal CPAP in Very Low Birth Weight Infants

Abstract To identify risk factors and neonatal outcomes associated with the early failure of “bubble” nasal continuous positive airway pressure (CPAP) in very low birth weight (VLBW) infants with respiratory distress syndrome (RDS). Following resuscitation and stabilization at delivery, a cohort of 261 consecutively inborn infants (birth weight #1250 g) was divided into three groups based on the initial respiratory support modality and outcome at 72 hours of age: “ventilator-started” group, “CPAP-failure” group, and “CPAP-success” group. CPAP was successful in 76% of infants #1250 g birth weight and 50% of infants ≤750 g birth weight. In analyses adjusted for postmenstrual age (PMA) and small for gestational age (SGA), CPAP failure was associated with need for positive pressure ventilation (PPV) at delivery, alveolar-arterial oxygen tension gradient (A-a DO 2 ) >180 mmHg on the first arterial blood gas (ABG), and severe RDS on the initial chest x-ray (adjusted odds ratio [95% CI] = 2.37 [1.02, 5.52], 2.91 [1.30, 6.55] and 6.42 [2.75, 15.0], respectively). The positive predictive value of these variables ranged from 43% to 55%. In analyses adjusted for PMA and severe RDS, rates of mortality and common premature morbidities were higher in the CPAP-failure group than in the CPAP-success group. Although several variables available near birth were strongly associated with early CPAP failure, they proved weak predictors of failure. A prospective controlled trial is needed to determine if extremely premature spontaneously breathing infants are better served by initial management with CPAP or mechanical ventilation.
On Access Checking in Capability-Based Systems

Public descriptions of capability-based system designs often do not clarify the necessary details concerning the propagation of access rights within the systems. A casual reader may assume that it is adequate for capabilities to be passed in accordance with the rules for data copying. A system using such a rule cannot enforce either the military security policy or the Bell and LaPadula rules. The paper shows why this problem arises and provides a taxonomy of capability-based designs. Within the space of design options defined by the taxonomy we identify a class of designs that cannot enforce the Bell-LaPadula rules and two designs that do allow their enforcement.
Effects of neutron spatial distributions on atomic parity nonconservation in cesium

Abstract We have examined modifications to the nuclear weak charge due to small differences between the spatial distributions of neutrons and protons in the Cs nucleus. We derive approximate formulae to estimate the value and uncertainty of this modification based only on nuclear rms neutron and proton radii. Present uncertainties in neutron distributions in Cs are difficult to quantify, but we conclude that they should not be neglected when using atomic parity nonconservation experiments as a means to test the Standard Model.
The sonar of dolphins

Introduction The Receiver System Characteristics of the Receiver for Simple Signals Characteristics of the Receiver for Complex Signals The Sonar Signal Transmission System Characteristics of the Transmission System Characteristics of Dolphin Sonar Signals Capabilities of the Active Sonar System Biosonar Discrimination and Target Recognition Biosonar Signal Processing Models A Comparison Between the Sonar of Bats and Dolphins A Road Map for Future Research
Review of methods to probe single cell metabolism and bioenergetics

Single cell investigations have enabled unexpected discoveries, such as the existence of biological noise and phenotypic switching in infection, metabolism and treatment. Herein, we review methods that enable such single cell investigations specific to metabolism and bioenergetics. Firstly, we discuss how to isolate and immobilize individuals from a cell suspension, including both permanent and reversible approaches. We also highlight specific advances in microbiology for its implications in metabolic engineering. Methods for probing single cell physiology and metabolism are subsequently reviewed. The primary focus therein is on dynamic and high-content profiling strategies based on label-free and fluorescence microspectroscopy and microscopy. Non-dynamic approaches, such as mass spectrometry and nuclear magnetic resonance, are also briefly discussed.
3D simulations of Einstein's equations: Symmetric hyperbolicity, live gauges, and dynamic control of the constraints

We present three-dimensional simulations of Einstein's equations implementing a symmetric hyperbolic system of equations with dynamical lapse. The numerical implementation makes use of techniques that guarantee linear numerical stability for the associated initial-boundary value problem. The code is first tested with a gauge wave solution, where rather larger amplitudes and for significantly longer times are obtained with respect to other state of the art implementations. Additionally, by minimizing a suitably defined energy for the constraints in terms of free constraint-functions in the formulation one can dynamically single out preferred values of these functions for the problem at hand. We apply the technique to fully three-dimensional simulations of a stationary black hole spacetime with excision of the singularity, considerably extending the lifetime of the simulations.
Location of modeling errors using modal test data

The method uses the cross-unity check between a flexibility matrix derived from modal test data and the analytical stiffness matrix to locate the errors; the method cannot determine the changes needed to correct the errors. Sensitivity of the method to lack of orthogonality in measured modes is discussed
The first tris(n-butyl) transition metal complex. Synthesis and structures of the fifteen electron chromium(III) alkyls [ButSi(CH2PMe2)3]CrMe3 and [ButSi(CH2PMe2)3]CrBun3

Reaction of the phosphine adduct [ButSi(CH2PMe2)3]CrCl3 with alkyl-lithium reagents gives the first octahedral chromium(III) trialkyls [ButSi(CH2PMe2)3]CrR3(R = Me, Bun); both compounds have been crystallographically characterized and the n-butyl compound is found to be remarkably resistant to β-elimination.
Three-dimensional inviscid analysis of the scramjet inlet flow field

A computer code has been developed to analyze the inviscid flow field in a supersonic combustion ramjet (scramjet) inlet. The code uses the three-dimensional Euler equations in full conservation form to describe the inlet flow. An algebraic numerical coordinate transformation is used to generate a set of boundary-fitted curvilinear coordinates. The governing equations are solved by a time-asymptotic, unsplit, two-step, finite-difference method. This method is highly efficient on the vector processing computers for which the current code is written. Detailed results are presented for two scramjet inlet configurations over a range of Mach numbers. The calculated results are compared with the available experimental and theoretical results.
Who changes the string coupling

Abstract In general bosonic closed string backgrounds the ghost-dilaton is not the only state in the semi-relative BRST cohomology that can change the dimensionless string coupling. This fact is used to establish complete dilaton theorems in closed string field theory. The ghost-dilaton, however, is the crucial state: for backgrounds where it becomes BRST trivial we prove that the string coupling becomes an unobservable parameter of the string action. For backgrounds where the matter CFT includes free uncompactified bosons we introduce a refined BRST problem by including the zero-modes “ x ” of the bosons as legal operators on the complex. We argue that string field theory can be defined on this enlarged complex and that the BRST cohomology captures accurately the notion of a string background. In this complex the ghost-dilaton appears to be the only BRST-physical state changing the string coupling.
T self-dual transverse space and gravity trapping

Abstract We advocate that the orbifold Z 2 symmetry of the gravity trapping model proposed by Randall and Sundrum can be seen, in appropriate coordinates, as a symmetry that exchanges the short distances with the large ones. Using diffeomorphism invariance, we construct extensions defined by patch glued together. A singularity occurs at the junction and it is interpreted as a brane, the jump brane, of codimension one. We give explicit realization in ten and eleven dimensional supergravity and show that the lower dimensional Planck scale on the brane is finite. The standard model would be trapped on a supersymmetric brane located at the origin whereas the jump brane would surround it at a finite distance. The bulk interactions could transmit the supersymmetry breaking from the jump brane to the SM brane.
Distributed Protocols for Interference Management in Cooperative Networks

In scenarios where devices are too small to support MIMO antenna arrays, symbol-level cooperation may be used to pool the resources of distributed single-antenna devices to create a virtual MIMO antenna array. We address design fundamentals for distributed cooperative protocols where relays have an incomplete view of network information. A key issue in distributed networks is potential loss in spatial reuse due to the increased radio footprint of flows with cooperative relays. Hence, local gains from cooperation have to balance against network level losses. By using a novel binary network model that simplifies the space over which cooperative protocols must be designed, we develop a mechanism for the systematic and computational development of cooperative protocols as functions of the amount of network state information available at relay nodes. Through extensive network analysis and simulations, we demonstrate the successful application of this method to a series of protocols that span a range of network information availability at cooperative relays.
Levelling the road ahead: guidelines for the creation of WWW pages accessible to blind and visually handicapped users

Traditionally, it has been the role of the librarian to locate, select, organize, and disseminate mainly print information resources. With the advent of online services, this role is now being extended to include providing information about electronic resources.
Cyclization of benzyne-tethered alkyllithiums: preparation of 3-substituted benzocyclobutenes and 5-substituted tetralins

Abstract A five-step, one-pot preparation of isomerically pure 3-substituted benzocyclobutenes or 5-substituted tetralins in 20–40% yield from the appropriate α-(2-fluorophenyl)-ω-iodoalkane, involving generation and subsequent 4- or 6-exo cyclization of a benzyne-tethered alkyllithium, is described.
Detecting a Network Failure

Measuring the properties of a large, unstructured network can be difficult: One may not have full knowledge of the network topology, and detailed global measurements may be infeasible. A valuable approach to such problems is to take measurements from selected locations within the network and then aggregate them to infer large-scale properties. One sees this notion applied in settings that range from Internet topology discovery tools to remote software agents that estimate the download times of popular web pages. Some of the most basic questions about this type of approach, however, are largely unresolved at an analytical level. How reliable are the results? How much does the choice of measurement locations affect the aggregate information one infers about the network? We describe algorithms that yield provable guarantees for a particular problem of this type: detecting a network failure. Suppose we want to detect events of the following form in an n-node network: An adversary destroys up to k nodes or edg...
GENESIS AND EVOLUTION OF THE SKYRME MODEL FROM 1954 TO THE PRESENT

Not widely known facts on the genesis of the Skyrme model are presented in a historical survey, based on Skyrme's earliest papers and on his own published remembrance. We consider the evolution of Skyrme's model description of nuclear matter from the "Mesonic Fluid" model up to its final version, known as the baryon model. We pay special tribute to some well-known ideas in contemporary particle physics which one can find in Skyrme's earlier papers, such as: Nuclear Democracy, the Solitonic Mechanism, the Nonlinear Realization of Chiral Symmetry, Topological Charges, Fermi–Bose Transmutations, etc. It is curious to note in the final version of the Skyrme model gleams of Kelvin's "Vortex Atoms" theory. In conclusion we make a brief analysis of the validity of Skyrme's conjectures in view of recent results and pinpoint some questions which still remain.
Chiral Oxazaborolidine−Aluminum Bromide Complexes Are Unusually Powerful and Effective Catalysts for Enantioselective Diels−Alder Reactions

Treatment of the chiral oxazaborolidine 1 with AlBr3 generates the 1:1 complex 3, which is an even more potent Lewis acid catalyst than protonated 1 (i.e., 2) for enantioselective Diels−Alder reactions. Only 4 mol % of catalyst 3 is required to achieve yields and enantiomeric purities of 90% over a broad range of achiral dienes and dienophiles. The ligand from which 3 is derived can be recovered easily and with high efficiency. The method is illustrated by 22 examples.
Asset Allocation Models and Market Volatility

Asset allocation and risk management models assume at least short–term stability of the covariance structure of asset returns, but actual covariance and correlation relationships fluctuate dramatically. Moreover, correlations tend to increase in volatile periods, which reduces the power of diversification when it might most be desired. We propose a framework to both explain these phenomena and to predict changes in correlation structure. We model correlations between assets as resulting from the common dependence of returns on a marketwide factor. Through this link, an increase in market volatility increases the relative importance of systematic risk compared with the unsystematic component of returns. The increase in the importance of systematic risk results, in turn, in an increase in asset correlations. We report that a large portion of the variation in correlation structures can be attributed to variation in market volatility. Moreover, market volatility contains enough predictability to construct use...
Prescribed Pattern Transformation in Swelling Gel Tubes by Elastic Instability

We present a study on swelling-induced circumferential buckling of tubular shaped gels. Inhomogeneous stress develops as the gel swells under mechanical constraints, which gives rise to spontaneous buckling instability without an external force. Full control over the postbuckling pattern is experimentally demonstrated. A simple analytical model is developed using elastic energy to predict stability and postbuckling patterns upon swelling. Analysis reveals that the height to diameter ratio is the most critical design parameter to determine the buckling pattern, which agrees well with experimental and numerical results.
Liberalization of the Capital Account: Experiences and Issues

This paper reviews the experience with capital controls in industrial and developing countries, considers the policy issues raised when the effectiveness of capital controls diminishes, examines the medium-term benefits and costs of an open capital account, and analyzes the policy measures that could help sustain capital account convertibility. As the effectiveness of capital controls eroded more rapidly in the 1980s than in earlier periods, new constraints were placed on the formulation of stabilization and structural reform programs. However, experience suggests that certain macroeconomic, financial, and risk management policies would allow countries to attain the benefits of capital account convertibility and reduce the financial risks created by an open capital account.
Finding communities in linear time: a physics approach

We present a method that allows for the discovery of communities within graphs of arbitrary size in times that scale linearly with their size. This method avoids edge cutting and is based on notions of voltage drops across networks that are both intuitive and easy to solve regardless of the complexity of the graph involved. We additionally show how this algorithm allows for the swift discovery of the community surrounding a given node without having to extract all the communities out of a graph.
Genome Justice: Genetics and Group Rights

An introduction to the Journal of Law, Medicine & Ethic’s volume based on the 2004 conference titled “Bioethics, Genetics and Group Rights,” held at Arizona State University and sponsored by the Lincoln Center for Applied Ethics. The introduction gives an overview of the conference topic and the author’s papers. The accelerated rate of innovation within biotechnology and increasing importance of human genetic information has triggered complex and compelling issues for researchers, lawyers, health professionals, and bioethicists. Although biotechnology can and does hold great capacity for improvements in individual health care, genomic research on populations has increasingly inspired controversy because of the implications of such research for particular groups. The various articles within this symposium develop an understanding of the key issues that surround competing claims for ownership of human genetic materials and technological innovations derived from these materials. The contributors to this symposium maintain a commitment to identifying current scientific issues and also identifying standards for developing transformative ethical and legal frameworks to consider these issues. This symposium demonstrates that the standard frameworks for analysis within contemporary bioethics and law must be adapted to better address the emerging cultural, social, and political conflicts over the use of human genetic material. Together, the articles in this symposium provide a rich theoretical context within which to formulate new constructs of law and ethics that can inform our domestic policies in the area of genomics research.
Monaural Auditory Adaptation as Measured by Simple Reaction Time

Pre- and post-reaction time measures were compared following 7 min of monaural auditory adaptation. The adapting stimulus utilised was a 500 Hz pure tone presented at an intensity level of 50 dB SPL for a period of 7 minutes. The pre- and post-adaptation reaction time measures were obtained for the frequences 400, 8000, and 10,000 Hz at intensity levels of 50, 60, and 70 dB SPL. The results revealed a significant increase in the post-adaptation reaction time measures for all of the frequencies and intensities tested and would suggest that reaction time measures can be utilised in the study of auditory adaptation phenomena.