cssi/SciSciGPT-SciSciNet huggingface dataset:
Measurements of flows in the DIII-D divertor by Mach probes

First measurements of Mach number of background plasma in the DIII-D divertor are presented in conjunction with temperature T{sub e} and density n{sub e} using a fast scanning probe array. To validate the probe measurements, the authors compared the T{sub e}, n{sub e} and J{sub sat} data to Thomson scattering data and find good overall agreement in attached discharges and some discrepancy for T{sub e} and n{sub e} in detached discharges. The discrepancy is mostly due to the effect of large fluctuations present during detached plasmas on the probe characteristic; the particle flux is accurately measured in every case. A composite 2-D map of measured flows is presented for an ELMing H-mode discharge and they focus on some of the details. They have also documented the temperature, density and Mach number in the private flux region of the divertor and the vicinity of the X-point, which are important transition regions that have been little studied or modeled. Background parallel plasma flows and electric fields in the divertor region show a complex structure.
Palladium-Catalyzed Borylation of Aryl and Heteroaryl Halides Utilizing Tetrakis(dimethylamino)diboron: One Step Greener

The palladium-catalyzed borylation of aryl and heteroaryl halides with a novel borylating agent, tetrakis(dimethylamino)diboron [(Me2N)2B–B(NMe2)2], is reported. The method is complementary to the previously reported method utilizing bis-boronic acid (BBA) in that certain substrates perform better under one set of optimized reaction conditions than the other. Because tetrakis(dimethylamino)diboron is the synthetic precursor to both BBA and bis(pinacolato)diboron (B2Pin2), the new method represents a more atom-economical and efficient approach to current borylation methods.
Toward an Epistemology of Practice

Higher and postexperience education in many parts of the world have unfortunately overlooked what practice can contribute to our knowledge base interactively with and distinctly from classroom educ...
Equation-of-state data of synthetic uranus

Abstract New equation-of-state data for the liquid mixture we call synthetic Uranus is discussed. This liquid was double-shocked to 220 GPa and 3 g/cm2. These data are coincident with the adiabat of Uranus calculated by Hubbard and Marley.
Controlling film growth with selective excitation: Chemical vapor deposition growth of silicon

We propose a method of controlling the growth mode in an epitaxial system. It takes advantage of differences in the vibrational frequencies of adatom–substrate bonds at terraces and steps. With a properly tuned infrared laser, one can selectively excite only the adatom–substrate bonds at steps and enhance the mobility of these adatoms, consequently promoting step-flow growth and reducing film roughness. The feasibility of this method is shown theoretically with respect to the prototype system of chemical vapor deposition growth of silicon.
Aggregation and multi-level control in discrete event dynamic systems

In this paper we consider higher-level aggregate modelling and control of discrete-event dynamic systems (DEDS). The higher-level models considered correspond to associating specified sequences of events in the original system to single macroscopic events in the higher-level model. We also consider the problem of designing a compensator that can be used to restrict microscopic behavior so that the system will only produce strings of these primitive sequences or tasks. With this lower level control in place we can construct higher-level models which typically have many fewer states and events than the original system. A complete treatment of the topics presented here can be found in [5].
Posterior Cloaca: A Unique Defect

The authors present nine cases of a unique defect in which urethra and vagina are fused together forming a urogenital sinus that deviates posteriorly and opens in the anterior rectal wall at the anus or immediately anterior to it. The rectum is essentially normal or may be minimally anteriorly mislocated. The authors call this defect posterior cloaca. The diagnosis requires a suspicious observer and a meticulous examination of the female genitalia. A complete urologic evaluation is mandatory because 88% of these patients have important associated urologic defects. Our patients were operated on via a posterior sagittal transanorectal approach, which allowed a full dissection and mobilization of urethra and vagina together to be placed in a normal location. Rectal dissection and mobilization was avoided to preserve bowel control. Seven patients enjoy bowel and urinary control. One patient was lost to follow-up, and one patient with a severely dysplastic sacrum suffers from fecal and urinary incontinence.
Examples of relative deformation spaces that are not locally connected

We provide an infinite family of pared manifolds with the property that the relative deformation spaces of hyperbolic structures on these manifolds are not locally connected. This is a natural extension of the recent result of Bromberg that shows the space of Kleinian punctured torus groups is not locally connected.
Disparities in Labor Market Outcomes across Geopolitical Regions in Nigeria. Fact or Fantasy

Questions focused on understanding Africa's lack of growth are not new in economics research. Ethnic fragmentation is one of the many reasons suggested for lack of growth of many developing countries especially in Africa. This is because many countries that are ethnically fragmentized find it difficult agreeing on societal goals and instead, focus on achieving dominance in the political arena of the country. These actions usually lead to: ethnic conflict, corruption, instability and other factors that hamper growth in the long-run. Nigeria is no stranger to the scenario described above. The basis of most ethnic and regional conflicts is claims of the marginalization of particular groups. Documented and anecdotal evidence of marked differences in basic economic and social indicators are usually the starting point for these assertions. However, general perception and beliefs play a role in solidifying these claims. In this paper, evidence of labor market disparities in Nigeria is sought first using descriptive analysis of the data. Subsequently, I test the null hypothesis that there are no significant differences in labor market outcomes across geopolitical regions using econometric techniques. By means of an instrument first suggested by Osilli and Long (2003) but constructed similarly to Uwaifo (2006), I estimate the returns to education using two stage least squares. This instrument is based on the exogenous implementation and withdrawal of free education across regions and states in Nigeria over time. I derive estimates for both Northern and Southern Nigeria.
Magnetic reconnection with asymmetry in the outflow direction

[1] Magnetic reconnection with asymmetry in the outflow direction occurs in the Earth's magnetotail, coronal mass ejections, flux cancellation events, astrophysical disks, spheromak merging experiments, and elsewhere in nature and the laboratory. A control volume analysis is performed for the case of steady antiparallel magnetic reconnection with asymmetric downstream pressure to derive scaling relations for the outflow velocity from each side of the current sheet and the reconnection rate. Simple relationships for outflow velocity are presented for the incompressible case and the case of symmetric downstream pressure but asymmetric downstream density. Asymmetry alone is not found to greatly affect the reconnection rate. The flow stagnation point and magnetic field null do not coincide in a steady state unless the pressure gradient is negligible at the flow stagnation point. The predictions of the model are compared with resistive MHD simulations of driven reconnection with asymmetry in the outflow direction.
A new method for quadratic curve detection using K-RANSAC with acceleration techniques

Abstract In this paper, we propose several K-RANSAC algorithms for quadratic curve detection based on random sample consensus [M.A. Fischler and R.C. Bolles, Commun. ACM 24, 381–395 (1981)]. The proposed K-RANSAC algorithms are memory efficient and allow the user to project a probability of success in detection. It is shown that at the cost of a small probability of failure, running time of the proposed algorithms can be attractive. Moreover, the proposed algorithms treat the detection problem in the image space; thus, tolerance can be accurately compensated. Geometric properties of the quadratic curves are exploited to provide speed-up for the basic random sample consensus algorithms. Random pre-sampling provides further speed-up. Throughout the paper, experiments are conducted to illustrate the new algorithms.
Theoretical versus practical explanation in political economy and economic sociology: the case of Tocqueville

This article represents an attempt to show the relevance of Tocqueville’s analyses of economic phenomena to modern political economy and economic sociology. The entry point is his approach to explanation, which is midway between value neutrality (Weber) and the idea that explanations must lead to social change (Marx). Tocqueville instead argues that the analyst (here of economic phenomena) should focus on as well as encourage the actors’sense of freedom. This argument is illustrated with the help of Tocqueville’s analysis of the economy in Democracy in America, Recollections and The Old Regime and the Revolution.
Social network predictors of latrine ownership.

Abstract Poor sanitation, including the lack of clean functioning toilets, is a major factor contributing to morbidity and mortality from infectious diseases in the developing world. We examine correlates of latrine ownership in rural India with a focus on social network predictors. Participants from 75 villages provided the names of their social contacts as well as their own relevant demographic and household characteristics. Using these measures, we test whether the latrine ownership of an individual's social contacts is a significant predictor of individual latrine ownership. We also investigate whether network centrality significantly predicts latrine ownership, and if so, whether it moderates the relationship between the latrine ownership of the individual and that of her social contacts. Our results show that, controlling for the standard predictors of latrine ownership such as caste, education, and income, individuals are more likely to own latrines if their social contacts own latrines. Interaction models suggest that this relationship is stronger among those of the same caste, the same education, and those with stronger social ties. We also find that more central individuals are more likely to own latrines, but the correlation in latrine ownership between social contacts is strongest among individuals on the periphery of the network. Although more data is needed to determine how much the clustering of latrine ownership may be caused by social influence, the results here suggest that interventions designed to promote latrine ownership should consider focusing on those at the periphery of the network. The reason is that they are 1) less likely to own latrines and 2) more likely to exhibit the same behavior as their social contacts, possibly as a result of the spread of latrine adoption from one person to another.
First Science Observations with SOFIA/FORCAST: The FORCAST Mid-infrared Camera

The Stratospheric Observatory For Infrared Astronomy (SOFIA) completed its first light flight in May of 2010 using the facility mid-infrared instrument FORCAST. Since then, FORCAST has successfully completed 13 science flights on SOFIA. In this Letter, we describe the design, operation, and performance of FORCAST as it relates to the initial three Short Science flights. FORCAST was able to achieve near-diffraction-limited images for λ > 30 μm allowing unique science results from the start with SOFIA. We also describe ongoing and future modifications that will improve overall capabilities and performance of FORCAST.
Fast power routing through HVDC

The objective of this paper is to investigate the fast power-routing capability of line current commutating (LCC)-HVDC. Such capability is most desired in future grids with high penetration of renewable energy sources (e.g., wind and solar). The technology presented in this paper replaces the traditional LCC-HVDC rectifier power order control by an ac voltage-mode control. This technology enables the HVDC rectifier ac bus to act as an infinite bus and absorb fluctuating wind power. A study system consisting of an ac system, an LCC-HVDC, and a doubly fed induction generator-based wind farm is built in Matlab/SimPowersystems. Simulation studies are carried out to demonstrate the proposed HVDC rectifier control in routing fluctuating wind power and load change. Parameters of the proposed voltage-mode control are investigated to show their impact on HVDC power routing and ac fault recovery.
Architecting noncooperative networks

In noncooperative networks users make control decisions that optimize their individual performance measure. Focusing on routing, two methodologies for architecting noncooperative networks are devised, that improve the overall network performance. These methodologies are motivated by problem settings arising in the provisioning and the run time phases of the network. For either phase, Nash equilibria characterize the operating point of the network. The goal in the provisioning phase is to allocate link capacities that lead to systemwide efficient Nash equilibria. The solution of such design problems is, in general, counterintuitive, since adding link capacity might lead to degradation of user performance. For systems of parallel links, it is shown that such paradoxes cannot occur and that the optimal solution coincides with the solution in the single-user case. Extensions to general network topologies are derived. During the run time phase, a manager controls the routing of part of the network flow. The manager is aware of the noncooperative behavior of the users and makes its routing decisions based on this information while aiming at improving the overall system performance. We obtain necessary and sufficient conditions for enforcing an equilibrium that coincides with the global network optimum, and indicate that these conditions are met in many cases of interest. >
Inequality and public good provision: An experimental analysis

Abstract Recent studies report that economic inequality is associated with reduced government expenditures on social programs. Several prominent social scientists, including Putman (Putnam, R., 2000. Bowling Alone. Simon and Schuster, New York), attribute this to the detrimental “psychosocial effects” of group heterogeneity on cooperation. We test the hypothesis that inequality within a group reduces individual contributions in a public goods experiment. Unlike previous examinations of inequality and public good provision, we introduce inequality by manipulating the levels and distributions of fixed payments given to subjects. When made salient through public information about each individual's standing within the group, inequality reduces contributions to the public good for all group members.
Discovery of dysprosium, holmium, erbium, thulium and ytterbium isotopes

Currently, 31 dysprosium, 32 holmium, 32 erbium, 33 thulium and 31 ytterbium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the rst refereed publication, including the production and identication method, is presented.
Gravitational lensing of anisotropic sources

In strong gravitational lensing, the multiple images we see correspond to light rays that leave the source in slightly different directions. If the source emission is anisotropic, the images may differ from conventional lensing predictions (which assume isotropy). To identify scales on which source anisotropy may be important, we study the angle delta between the light rays emerging from the source, for different lensing configurations. If the lens has a power law profile M propto R^gamma, the angle delta initially increases with lens redshift and then either diverges (for a steep profile gamma<1), remains constant (for an isothermal profile gamma=1), or vanishes (for a shallow profile gamma>1) as zl approaches zs. The scaling with lens mass is roughly delta propto M^(1/(2-gamma)). The results for an NFW profile are qualitatively similar to those for a shallow power law, with delta peaking at about half the redshift of the source (not half the distance). In practice, beaming could modify the statistics of beamed sources lensed by massive clusters: for an opening angle theta_jet, there is a probability as high as P ~ 0.02-0.07 (theta_jet/{0.5} deg)^-1 that one of the lensed images may be missed (for 2 < zs < 6). Differential absorption within Active Galactic Nuclei could modify the flux ratios of AGNs lensed by clusters; a sample of AGNs lensed by clusters could provide further constraints on the sizes of absorbing regions. Source anisotropy is not likely to be a significant effect in galaxy-scale strong lensing.
PSF anisotropy and systematic errors in weak lensing surveys

Given the basic parameters of a cosmic shear weak lensing survey, how well can systematic errors due to anisotropy in the point spread function (PSF) be corrected? The largest source of error in this correction to date has been the interpolation of the PSF to the locations of the galaxies. To address this error, we separate the PSF patterns into components that recur in multiple exposures/pointings and those that vary randomly between different exposures (such as those due to the atmosphere). In an earlier study we developed a principal component approach to correct the recurring PSF patterns. In this paper we show how randomly varying PSF patterns can also be circumvented in the measurement of shear correlations. For the two-point correlation function this is done by simply using pairs of galaxy shapes measured in different exposures. Combining the two techniques allows us to tackle generic combinations of PSF anisotropy patterns. The second goal of this paper is to give a formalism for quantifying residual systematic errors due to PSF patterns. We show how the main PSF corrections improve with increasing survey area (and thus can stay below the reduced statistical errors), and we identify the residual errors which do not scale with survey area. Our formalism can be applied both to planned lensing surveys to optimize survey strategy and to actual lensing data to quantify residual errors.
Two-klystron binary pulse compression at SLAC

The Binary Pulse Compression system installed at SLAC was tested using two klystrons, one with 10 MW and the other with 34 MW output. By compressing 560 ns klystron pulses into 70 ns, the measured BPC output was 175 MW, limited by the available power from the two klystrons. This output was used to provide 100-MW input to a 30-cell X-band structure in which a 100-MV/m gradient was obtained. This system, using the higher klystron outputs expected in the future has the potential to deliver the 350 MW needed to obtain 100 MV/m gradients in the 1.8-m NLC prototype structure. This note describes the timing, triggering, and phase coding used in the two-klystron experiment, and the expected and measured network response to three- or two-stage modulation. >
Finite element modeling of self-loosening of bolted joints

A three-dimensional finite element (FE) model with the consideration of the helix angle of the threads was developed to simulate the second stage self-loosening of a bolted joint. The second stage self-loosening refers to the gradual reduction in clamping force due to the back-off of the nut. The simulations were conducted for two plates jointed by a bolt and a nut and the joint was subjected to transverse or shear loading. An M12 X 1.75 bolt was used. The application of the preload was simulated by using an orthogonal temperature expansion method. FE simulations were conducted for several loading conditions with different preloads and relative displacements between the two clamped plates. It was found that due to the application of the cyclic transverse load, microslip occurred between the contacting surfaces of the engaged threads of the bolt and the nut. In addition, a cyclic bending moment was introduced on the bolted joint. The cyclic bending moment resulted in an oscillation of the contact pressure on the contacting surfaces of the engaged threads. The microslip between the engaged threads and the variation of the contact pressure were identified to be the major mechanisms responsible for the self-loosening of a bolted joint. Simplified finite element models were developed that confirmed the mechanisms discovered. The major self-loosening behavior of a bolted joint can be properly reproduced with the FE model developed. The results obtained agree quantitatively with the experimental observations.
Human capital, migration strategy, and brain drain

Abstract This research was motivated by the increasing number of foreign students and scientists who are in the United States on temporary visas and who are able to change their status to permanent immigrant. Origin countries, among them industrialized western European nations, are concerned about losing many of their best-educated and most talented citizens. This article modifies and extends a theoretical model of optimal human capital investment before and after migration to shed new light on the emigration/immigration of the highly skilled, and explores some possible implications for the study of the so-called ‘brain drain’ phenomenon.
Isocyanate and carbodiimide synthesis by nitrene-group-transfer from a nickel(II) imido complex

The imido complex (dtbpe)Ni{N(2,6-(CHMe2)2C6H3)} reacts with CO and CNCH2Ph with addition at the Ni–N bond to give (dtbpe)Ni{C,N:η2-C(O)N(2,6-(CHMe2)2C6H3)} and (dtbpe)Ni{C,N:η2-C(NCH2Ph)N(2,6-(CHMe2)2C6H3)}; both complexes react further with CO to liberate the isocyanate and carbodiimide ligands with formation of (dtbpe)Ni(CO)2.
Phase-space quantization of field theory.

In this lecture, a limited introduction of gauge invariance in phase-space is provided, predicated on canonical transformations in quantum phase-space. Exact characteristic trajectories are also specified for the time-propagating Wigner phase-space distribution function: they are especially simple--indeed, classical--for the quantized simple harmonic oscillator. This serves as the underpinning of the field theoretic Wigner functional formulation introduced. Scalar field theory is thus reformulated in terms of distributions in field phase-space. This is a pedagogical selection from work published and reported at the Yukawa Institute Workshop ''Gauge Theory and Integrable Models'', 26-29 January, 1999.
Autonomic QoS Optimization of Real-Time Internet Audio Using Loss Prediction and Stochastic Control

Quality of Internet audio is highly sensitive to packet loss caused by congestion in links. Packet loss for audio is normally rectified by adding redundancy using Forward Error Correction (FEC). Alternatively, path diversity mechanisms are used to improve reliability and thus session quality. To achieve optimized receiver audio quality for transmissions using single or multiple paths, the authors propose a self-adaptive joint Error and Rate Control framework based on packet loss prediction and on-line quality assessment. The Error Control chooses appropriate FEC proactively to preserve quality with optimal bandwidth, using a Markov Decision Process (MDP) and a stochastic inventory control, a novel approach for multimedia error recovery. The Rate Control uses a quality optimization model to determine the optimal dispersion over single or multiple paths. This paper will present results using simulation and Internet experiments to show the superiority of this mechanism over other similar techniques.
Sovereign debt distress and corporate spillover impacts

In much of the standard corporate finance literature in which sovereign debt is treated as a risk free asset, corporate bond prices are seen to depend on idiosyncratic risk factors specific to the issuing company, with public debt playing an indirect role to the extent that it affects the term structure of interest rates. In the corporate world, however, the ability of a borrower to access international capital markets and the terms according to which it can raise capital depend not only on its own creditworthiness, but also on the financial health of its home-country sovereign. In times of financial stress, when investors lose confidence in the government's ability to use public finances to stabilize the economy or provide a safety net for corporations in distress, markets' assessment of private credit risk takes on a completely different dynamic than during normal times, incorporating an additional risk premium to compensate investors for the potential consequences of sovereign default. Using a new database that covers nearly every emerging-market corporate and sovereign entity that has issued bonds on global markets between 1995 and 2009, this paper investigates the degree to which heightened sovereign default risk perceptions during times of market turmoil influence the determination of corporate bond yield spreads, controlling for specific bond attributes and common global risk factors. Econometric evidence presented confirms that investors' perceptions of sovereign debt problems translate into higher costs of capital for private corporate issuers, with the magnitude of such costs increasing at times when sovereign bonds trade at spreads exceeding a threshold of 1000 bps. The key policy recommendation emerging from the analysis relates to the need to improve sovereign creditworthiness in order to prevent a loss in investor confidence that could trigger a panicky sell-off in sovereign debt with adverse macroeconomic and fiscal consequences. Implications for future research point to the need to develop better models of corporate bond pricing and valuation, recognizing explicitly the role of sovereign credit risk.
Rhodium-catalyzed cyclopropanations of 2-aryl-2H-chromenes with dialkyl malonate esters. A comparison of α-diazo derivatives and phenyliodonium ylides

Abstract Rhodium-catalyzed reactions of 2-aryl-substituted 2H-chromenes with α-diazo esters prepared from dimethyl and tert-butyl methyl malonates were investigated, and the results were compared with reactions carried out with phenyliodonium ylides prepared from the same esters. The phenyliodonium ylide prepared from dimethyl malonate was found to give superior yields of cyclopropane products compared to the corresponding α-diazo equivalent. However, this result was reversed with tert-butyl methyl malonate when Rh2(S-TBSP)4 was used to decompose the diazo compound. All reactions gave 1,1-cyclopropane diesters as single diastereomers.
From reference frames to relativistic experiments: Absolute and relative radio astrometry

Reference systems and frames are crucial for high precision absolute astrometric work, and their foundations must be well-defined. The current frame, the International Celestial Reference Frame, will be discussed: its history, the use of the group delay as the measured quantity, the positional accuracy of 0.3 mas, and possible future improvements. On the other hand, for the determination of the motion of celestial objects, accuracies approaching 0.01 mas can be obtained by measuring the differential position between the target object and nearby stationary sources. This relative astrometric technique uses phase referencing, and the current techniques and limitations are discussed, usingthe results from four experiments. Brief comments are included on the interpretation of the Jupiter gravity deflection experiment of September 2002.
Catastrophe Insurance, Capital Markets, and Uninsurable Risks

This article addresses the question why private insurance companies in the United States are not willing to provide insurance against catastrophic events (such as earthquakes, hurricanes, and floods). One expects such a market to exist, since the demand for catastrophe insurance is high and the traditional reasons for risks to be "uninsurable" (such as moral hazard) are not present. We argue that catastrophic risks require insurers to hold large amounts of liquid capital, but institutional factors (accounting, tax, and takeover risk) make insurers reluctant to do this. In other words, the basic problem rests in the capital markets, not in the insurance markets. Instruments such as Act of God bonds and catastrophe futures and options contracts are being developed to solve the problem. Nevertheless, it appears that the government will continue to be an essential player in catastrophe insurance markets.
An optimal control approach to the multi-agent persistent monitoring problem in two-dimensional spaces

We address the persistent monitoring problem in two-dimensional mission spaces where the objective is to control the trajectories of multiple cooperating agents to minimize an uncertainty metric. In a one-dimensional mission space, we have shown that the optimal solution is for each agent to move at maximal speed and switch direction at specific points, possibly waiting some time at each such point before switching. In a two-dimensional mission space, such simple solutions can no longer be derived. An alternative is to optimally assign each agent a linear trajectory, motivated by the one-dimensional analysis. We prove, however, that elliptical trajectories outperform linear ones. With this motivation, we formulate a parametric optimization problem in which we seek to determine such trajectories. We show that the problem can be solved using Infinitesimal Perturbation Analysis (IPA) to obtain performance gradients on line and obtain a complete and scalable solution. Since the solutions obtained are generally locally optimal, we incorporate a stochastic comparison algorithm for deriving globally optimal elliptical trajectories. Numerical examples are included to illustrate the main result, allow for uncertainties modeled as stochastic processes, and compare our proposed scalable approach to trajectories obtained through off-line computationally intensive solutions.
From agile software development to agile businesses

Agile software development has proven to be a good fit for knowledge work in environments of high change rates, often resulting in hyper-productive teams. The bottom line seems to be that applying agile methods to software development projects reduces risk and time-to-market while high quality is achieved at the same time. We show how agility can be useful well beyond the context of individual projects, first, when managing a portfolio of projects of a company and second, when maneuvering a company in the marketplace. Companies can become more demand-driven and value-driven by embracing agility on these three levels and benefit from agility over a wider spectrum. Agile businesses react fast on changed circumstances, are flexible, bring response to the market as fast as possible, are proactive, and sense the change.
Some Aspects of Fan Noise Suppression Using High Mach Number Inlets

The results of a systematic study on the suppression of transonic fan noise by high velocity inlets or the socalled accelerating inlets are presented. The issues pertinent to the design of such fan-inlet systems are first examined in terms of a simplified model evolved from the well-known Morfey and Fisher theory.4 These issues are then examined in terms of the aero-acoustic data obtained from three distinct fan test facilities. It is found that the noise reduction due to an accelerating inlet correlates best with the geometric throat one-dimensional Mach number rather than, say, the peak wall Mach number. A typical reduction of 5 PNdb was measured with an inlet operating at a Mach number of about 0.72.
White Dwarf-Red Dwarf Systems Resolved with the Hubble Space Telescope. I. First Results

First results are presented for a Hubble Space Telescope (HST) Advanced Camera for Surveys snapshot study of white dwarfs with likely red dwarf companions. Of 48 targets observed and analyzed so far, 27 are totally or partially resolved into two or more components, while an additional 15 systems are almost certainly unresolved binaries. These results provide the first direct empirical evidence for a bimodal distribution of orbital separations among binary systems containing at least one white dwarf.
Pulsed Laser Deposition of Thin Silicon Nitride Films

Pulsed laser deposition of compressed Si3N4 powder has been used to grow thin SiNx films on a variety of substrates at substrate temperatures ranging from room temperature to 350°C. Film composition was analyzed by Auger electron spectroscopy. The SiN0.33 films have a band gap of 5.60 eV as measured by UV absorption. The FT-IR spectrum shows an absorption characteristic of Si-N. The Si/N ratio in the deposited films corresponding to various substrate temperatures has also been determined.
Adaptive stabilization of mobile manipulators

This paper considers the motion control problem for uncertain mobile manipulator systems comprised of a robotic arm mounted on a wheeled mobile platform; more specifically, we address the problem of stabilizing mobile manipulators in the presence of uncertainty regarding the system dynamic model. It is proposed that a simple and effective solution to this problem can be obtained by combining ideas from homogeneous system theory and adaptive control theory. Thus the proposed control system consists of two subsystems: a (homogeneous) kinematic stabilization strategy which generates a desired velocity trajectory for the mobile manipulator, and an adaptive control scheme which ensures that this velocity trajectory is accurately tracked. This approach is shown to provide arbitrarily accurate exponential stabilization to any desired configuration, and can be implemented without knowledge of the system dynamic model.
Leakage-Aware Interconnect for On-Chip Network

On-chip networks have been proposed as the interconnect fabric for future systems-on-chip and multi-processors on chip. Power is one of the main constraints of these systems and the interconnect consumes a significant portion of the power budget. In this paper, we propose four leakage-aware interconnect schemes. Our schemes achieve 10.13%-63.57% active leakage savings and 12.35%-95.96% standby leakage savings across schemes while the delay penalty ranges from 0% to 4.69%.
On the Invariance of the Rate of Return to Convex Adjustment Costs

Abstract The modified golden rule, which relates the rate of return on capital and the growth rate of the capital stock along long-run growth paths that maximize the utility of a representative infinitely lived consumer, is invariant to the introduction of convex capital adjustment costs. Therefore, along balanced growth paths in neoclassical optimal growth models with an exogenous long-run growth rate of capital, the rate of return is invariant to the introduction of convex adjustment costs, though the capital–labor ratio is reduced along such paths. In AK models, convex adjustment costs reduce the growth rate and rate of return on capital. Journal of Economic Literature Classification Number: E2.
Ex Ante Capacity Effects in Evolutionary Labor Markets with Adaptive Search

This study reports on computational experiments for an agent-based labor market model with adaptive choice and refusal of worksite partners and with endogenously evolving worksite behaviors. Two treatment factors are experimentally varied: market structure; and ex ante capacity constraints on potential work offers and job openings. Particular attention is focused on experimentally determined correlations between treatment factors and the formation of contractual networks among workers and employers, and between contractual network formation and the types of worksite interactions and welfare outcomes that these contractual networks support.
Testing Relativity with Solar System Dynamics

On November 20, 1982, the Mutch Memorial Station (Viking Lander 1) on the surface of Mars interrupted its transmission to Earth due to a loss of the information in its antenna pointing table. It was not heard from again. However, in over six years of operation since its landing in July, 1976, it and Viking Lander 2 have provided a set of ranging data which are sufficiently accurate to enable the Earth-Mars distance to be modeled to ±10m during that period. This unprecedented accuracy in a Solar System data set has been responsible for a major breakthrough in the accuracy of Solar System dynamical tests of relativistic gravity. It is the purpose of this talk to explain the data which are used in the solutions for the relativistic effects (Section 2), to explain the Solar System model which is used to fit the data and the process by which such fits are performed (Section 3), and to discuss the results (Section 4, see also Hellings et al., 1983) of our tests for the effects of the following: 1. The Large Numbers Hypothesis and a time-varying gravitational constant, 2. PPN parameters β,γ, and α1 along with the value of the solar quadrupole moment J2, 3. Moffat’s Nonsymmetric Gravitational Theory (which does not fall into the formalism of the PPN).
Confluent drawings: visualizing non-planar diagrams in a planar way.

We introduce a new approach for drawing diagrams. Our approach is to use a technique we call confluent drawing for visualizing non-planar graphs in a planar way. This approach allows us to draw, in a crossing-free manner, graphs—such as software interaction diagrams—that would normally have many crossings. The main idea of this approach is quite simple: we allow groups of edges to be merged together and drawn as “tracks” (similar to train tracks). Producing such confluent diagrams automatically from a graph with many crossings is quite challenging, however, so we offer two heuristic algorithms to test if a non-planar graph can be drawn efficiently in a confluent way. In addition, we identify several large classes of graphs that can be completely categorized as being either confluently drawable or confluently non-drawable.
Significant Life Experiences Revisited: A Review of Research on Sources of Environmental Sensitivity.

Summary Beginning with the study of significant life experiences initiated by Tanner, this article reviews a growing body of related research in the form of surveys, interviews, and questionnaires that explore people's accounts of the sources of their environmental interest, concern, and action. The questions, methods, and results of studies in this field are closely compared. In conclusion, the article notes that the experiences that people describe can be understood as exchanges between the ‘outer environment’ of the physical and social world and the ‘inner environment’ of people's own interests, aptitudes, and temperament, and that more attention needs to be paid to the influence of this ‘inner environment’ of individual differences.
Portrait of the American Agitator

Based on a study of techniques developed by far-right activists in the mid-1940s in the United States, the authors provide a detailed exploration of the theoretical motivations used by these agitators to build up their audiences. This exploration highlights the features of agitation, a form of political expression closely linked to fascist logics. Drawing on the social malaise that is its business, far-right agitation mobilizes a range of grievances that arouse destructive emotions in those that it targets: mistrust, dependence, exclusion, anxiety and disillusionment. Unlike reformist or revolutionary activism, it does not aim for real social change but instead urges audiences to focus their anger on personified targets, without challenging the social, economic and political status quo.
Accelerator for the production of tritium (APT)

A collaborative study by Los Alamos and Brookhaven National Laboratories investigating a facility to produce tritium for the USA's defense needs indicates that a 1.6-GeV, 250-mA proton accelerator is required. A reference design of this accelerator starts with two parallel 125-keV injectors feeding the 350-MHz radio-frequency quadrupoles that funnel at 2.5-MeV into a 700-MHz drift-tube linac. This then injects at 100 MeV into a 1400-MHz side-coupled linac. The accelerator will cost about $1.2B and require 746 MW of electricity. The accelerator components, the control and diagnostics, and the accelerator facility are discussed, and design considerations are presented. >
A Robust Controller Interpolation Design Technique

Switching or blending among controllers is termed controller interpolation. This paper investigates a robust controller interpolation technique and applies it to an experimental test bed. Although an interpolated controller is composed of linear time-invariant (LTI) controllers stabilizing the LTI plant, closed-loop performance and stability are not guaranteed. Thus, it is of interest to design the interpolated controller to guarantee closed-loop stability and a performance level for all interpolation signals describing controller switching sequences and combinations. The performance metric that is under investigation in this paper is the H ? norm. A suboptimal robust interpolated-controller design algorithm is framed in terms of bilinear matrix inequalities. The motivating example demonstrates the efficacy of the robust interpolated-controller design.
Congress and the Presidency as News in the Nineteenth Century

However successful some recent presidents have been in exploiting their newsworthiness to define the national agenda and promote their politics before Congress, the available evidence suggests that presidents have enjoyed an advantage in press coverage over Congress throughout the twentieth century. The research reported here extends the comparative study of news about these institutions back into the early nineteenth century. A content analysis of 3,335 news articles in the Cleveland press for ten selected years from 1820 to 1876 reveals that the president did not always enjoy such an advantage. Rather, news during this era tended to be bifurcated, with presidents receiving most of the election-related reporting and Congress most of the news on the daily affairs of government. Congress's predominance in this latter realm persisted even as the volume of news about national affairs increased sharply in the 1870s. We conclude with the speculation that changes in the pattern of news coverage early in this ce...
Materiality Decisions and the Correction of Accounting Errors

ABSTRACT: We test conjectures about the determinants of materiality judgments by examining a financial reporting choice made by firms that discover errors in prior years' financial statements. From late 2004 to mid‐2006, more than 250 U.S. firms uncovered and corrected operating lease accounting errors either by formal restatement—required for errors deemed material—or by a less visible current‐period “catch‐up” adjustment. We test the role of materiality considerations outlined in SAB No. 99 as well as factors outside authoritative guidance in explaining the correction method chosen. Although both quantitative and qualitative materiality considerations cited in the guidance explain a large portion of the variation in firms' error correction decisions, we find that the prior actions of other firms also appear to play a major role. We also find that clerical considerations, but not strategic disclosure concerns, help explain cross‐sectional variation in the timing of firms' error correction announcements.
Design considerations for integrated electronic devices

Some fundamental factors affecting the design of integrated electronic devices are discussed, particularly the influence of shrinkage. It is concluded that the considerable advantages of integrated devices compared to conventional devices, such as very small volume and weight, and reduced number of metallic connections, has to be paid for by higher shrinkage in fabrication. The resulting increase in cost may be made very small if the design of the integrated device allows the extent of integration to be adjusted to the shrinkage rate. Two considerations are advanced to reduce partially this higher shrinkage. One is that the resultant high cost of the integrated device justifies a higher investment in the fabrication process of the integrated device than for the individual units. The other is that methods of doctoring integrated devices may be effectively used to reduce the shrinkage.
Distinguishing partitions of complete multipartite graphs

A distinguishing partition of a set X with automorphism group aut( X ) is a partition of X that is fixed by no nontrivial element of aut( X ) . In the event that X is a complete multipartite graph with its automorphism group, the existence of a distinguishing partition is equivalent to the existence of an asymmetric hypergraph with prescribed edge sizes. An asymptotic result is proven on the existence of a distinguishing partition when X is a complete multipartite graph with m 1 parts of size n 1 and m 2 parts of size n 2 for small n 1 , m 2 and large m 1 , n 2 . A key tool in making the estimate is counting the number of trees of particular classes.
Retrieval of snow parameters by iterative inversion of a neural network

The inversion of snow parameters from passive microwave remote sensing measurements is performed, using an iterative inversion of a neural network (NN) trained with a dense-media multiple-scattering model. Inversion of four parameters is performed based on five brightness temperatures. The four parameters are mean grain size of ice particles in snow, snow density, snow temperature, and snow depth. Iterative inversion of a data-driven forward NN model is justified on a theoretical and methodological basis. An error analysis is performed, comparing iterative inversion of a forward model with the use of an explicit inverse for the retrieval of independent snow parameters from their corresponding measurements. The NN iterative inversion algorithm is further illustrated by reconstructing a synthetic terrain of snow parameters from their corresponding measurements, inverting all four parameters simultaneously. The reconstructed parameter contours are in good agreement with the original synthetic parameter contours. >
Laser pyrolysis studies of OH reaction rates with several butenes at 1200 K

Using a laser pyrolysis/laser fluorescence method, we have measured the rate constants for OH reacting with 1-butene, t-2-butene, isobutene, and 2,3-dimethyl-2-butene near 1200 K. The butene rate constants are large, ranging from 2.0–3.7 × 10−11 cm−3 s−1, and increase with the number of allylic hydrogens. Transition-state theory considerations indicate these allylic hydrogens are easily abstracted, in contrast to prior observations on propene.
STUDENT AID SIMPLIFICATION: LOOKING BACK AND LOOKING AHEAD

Each year, 14 million households seeking federal aid for college complete a detailed questionnaire about their fi nances, the Free Application for Federal Student Aid (FAFSA). With 116 questions, the FAFSA is almost as long as IRS Form 1040 and substantially longer than Forms 1040EZ and 1040A. Aid for college is intended to increase college attendance by reducing its price and loosening liquidity constraints. Economic theory, empirical evidence, and common sense suggest that complexity in applying for aid could undermine its ability to affect schooling decisions. In 2006, Dynarski and Scott-Clayton published in this journal an analysis of complexity in the aid system that generated considerable discussion in academic and policy circles. Over the next few years, complexity in the aid system drew the attention of the media, advocacy groups, presidential candidates, the National Economic Council, and the Council of Economic Advisers. A fl urry of legislative and agency activity followed. In this article, we provide a fi ve-year retrospective of what has changed in the aid application process, what has not, and the possibilities for future reform.