cssi/SciSciGPT-SciSciNet huggingface dataset:
Investment dynamics in markets with endogenous demand

I examine entry into markets where demand is an increasing function of past sales because of learning, networks, or fashion. Demand is initially unknown (with firms learning in Bayesian fashion) and grows endogenously over time. The competitive expansion path and the efficient/monopoly solution differ not only with respect to levels (the market’s investment is too low), but also time patterns: externalities contribute to S-shaped diffusion. There is also path-dependence: small initial differences may determine whether the market will grow or not open. Policy arguments for subsidizing entry into new markets, especially in infant export industries, are examined.
Total Synthesis of the Congested Propellane Alkaloid (−)‐Acutumine

The enantioselective total synthesis of (-)-acutumine is described. The synthetic strategy was inspired by the premise that the cyclohexenone ring could be derived from an aromatic precursor. After successful construction of a propellane model system, an initial attempt to prepare the spirocyclic subunit was thwarted by incorrect regioselectivity in a radical cyclization. A second-generation approach involving a radical-polar crossover reaction was successful, and the chemistry developed in the aforementioned model system was then applied to synthesize the natural product. Key reactions included a phenolic oxidation, a diastereoselective ketone allylation utilizing Nakamura's chiral allylzinc reagent, an anionic oxy-Cope rearrangement, an acid-promoted cyclization of a secondary amine onto an α,β-unsaturated ketal, and a regioselective methyl enol etherification of a 1,3-diketone.
Special relativity: A Centenary perspective

This article is a partly pedagogical, partly historical and partly technical review of special relativity and its experimental foundations, in honor of the centenary of Einstein's annus mirabilis.
Highly Accurate CAD Tools for Cranial Implants

Prefabricated patient-specific cranial implants are especially useful for large cranial defects. We present CAD tools for large cranial implants that include validation of fit prior to rapid prototype fabrication. Our CAD process first determines whether the prototype implant surface intersects adjacent soft-tissue structures via collision detection. If so, we measure the volume of both the intersected dura and unoccupied area under the implant. These data are used to determine whether the prototype implant requires modification. If modification is necessary, we deform the prototype implant surface via a thin plate spline warp. Second, we interactively create and verify the implant taper surface that connects the external and internal implant surfaces. The taper surface seats the implant onto the patient’s cranial defect site. The taper and patient’s skull surfaces may contact but must not intersect one another. Results from tests on five patient data sets show our CAD and validation methods result in implant designs which are an improvement over, and not feasible by, current manual implant preparation methods.
The Relationship of Cataract and Cataract Extraction to Age-related Macular Degeneration: The Beaver Dam Eye Study

Objective To examine the associations of cataract and cataract surgery with early and late age-related macular degeneration (AMD) over a 20-year interval. Design Longitudinal population-based study of age-related eye diseases. Participants Beaver Dam Eye Study participants. Methods Persons aged 43 to 86 years participated in the baseline examination in 1988–1990. Participants were followed up at 5-year intervals after the baseline examination. Examinations consisted of ocular examination with lens and fundus photography, medical history, measurements of blood pressure, height, and weight. Values of risk variables were updated, and incidences of early and late AMD were calculated for each 5-year interval. Odds ratios were computed using discrete linear logistic regression modeling with generalized estimating equation methods to account for correlation between the eyes and multiple intervals. Main Outcome Measures Age-related macular degeneration. Results After adjusting for age and sex, neither cataract nor cataract surgery was associated with increased odds for developing early AMD. Further adjusting for high-risk gene alleles ( CFH and ARMS2 ) and other possible risk factors did not materially affect the odds ratio (OR). However, cataract surgery was associated with incidence of late AMD (OR 1.93; 95% confidence interval [CI], 1.28–2.90). This OR was not materially altered by further adjusting for high-risk alleles ( CFH Y402H , ARMS2 ) or other risk factors. The OR for late AMD was higher for cataract surgery performed 5 or more years prior compared with less than 5 years prior. Conclusions These data strongly support the past findings of an association of cataract surgery with late AMD independent of other risk factors, including high-risk genetic status, and suggest the importance of considering these findings when counseling patients regarding cataract surgery. These findings should provide further impetus for the search for measures to prevent or delay the development of age-related cataract. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Bottom-Up and Top-Down Context-Sensitive Summary-Based Pointer Analysis

This paper addresses scalability and accuracy of summary-based context-sensitive pointer analysis formulated as a two-phase computation. The first phase, or bottom-up phase, propagates procedure summaries from callees to callers. Then, the second phase, or top-down phase, computes the actual pointer information. These two phases can be independently context-sensitive. Having observed the problems that procedural side effects cause, we developed a bottom-up phase that constructs concise procedure summaries in a manner that permits their subsequent removal. This transformation results in an efficient two-phase pointer analysis in the style of Andersen [1] that is simultaneously bottom-up and top-down context-sensitive. Context sensitivity becomes inherent to even a context-insensitive analysis allowing for an accurate and efficient top-down phase. The implemented context-sensitive analysis exhibits scalability comparable to that of its context-insensitive counterpart. For instance, to analyze 176.gcc, the largest C benchmark in SPEC 2000, our analysis takes 190 seconds as opposed to 44 seconds for the context-insensitive analysis. Given the common practice of treating recursive subgraphs context-insensitively, its accuracy is equivalent to an analysis which completely inlines all procedure calls.
Discovery and characterization of chromatin states for systematic annotation of the human genome

A plethora of epigenetic modifications have been described in the human genome and shown to play diverse roles in gene regulation, cellular differentiation and the onset of disease. Although individual modifications have been linked to the activity levels of various genetic functional elements, their combinatorial patterns are still unresolved and their potential for systematic de novo genome annotation remains untapped. Here, we use a multivariate Hidden Markov Model to reveal chromatin states in human T cells, based on recurrent and spatially coherent combinations of chromatin marks.We define 51 distinct chromatin states, including promoter-associated, transcription-associated, active intergenic, largescale repressed and repeat-associated states. Each chromatin state shows specific enrichments in functional annotations, sequence motifs and specific experimentally observed characteristics, suggesting distinct biological roles. This approach provides a complementary functional annotation of the human genome that reveals the genome-wide locations of diverse classes of epigenetic function.
Performance characteristics of a cosmology package on leading HPC architectures

The Cosmic Microwave Background (CMB) is a snapshot of the Universe some 400,000 years after the Big Bang The pattern of anisotropies in the CMB carries a wealth of information about the fundamental parameters of cosmology Extracting this information is an extremely computationally expensive endeavor, requiring massively parallel computers and software packages capable of exploiting them One such package is the Microwave Anisotropy Dataset Computational Analysis Package (MADCAP) which has been used to analyze data from a number of CMB experiments In this work, we compare MADCAP performance on the vector-based Earth Simulator (ES) and Cray X1 architectures and two leading superscalar systems, the IBM Power3 and Power4 Our results highlight the complex interplay between the problem size, architectural paradigm, interconnect, and vendor-supplied numerical libraries, while isolating the I/O filesystem as the key bottleneck across all the platforms.
Dynamics in atmospheric physics

Preface 1. Introductory remarks 2. Simple energy balance climate models 3. Effect of transport on composition 4. 'Statics' of a rotating system 5. Observed atmospheric structures 6. Equations of motion 7. Symmetric circulation models 8. Internal gravity waves, 1 9. Atmospheric tides 10. Internal gravity waves, 2 11. Rissby waves and the Gulf stream 12. Vorticity and quasi-geostrophy 13. The generation of eddies by instability, 1 14. Instability 2: energetics and climate implications Postscripts Appendix - Gravity wave program References.
Raising the quality of secondary education in East Asia

The author seeks to broaden our understanding of the determinants of student achievement among East Asian economies using the TIMSS-R data set and, in the process, to remedy some of the ambiguities in the literature to date. These ambiguities are frequently due to the sparseness of detailed data on students, teachers, and schools. The TIMSS-R data set offers detailed information on these variables, which is not typically available from other sources, allowing the author to isolate the impact of various factors affecting student achievement, while controlling for specific characteristics of the students, teachers, and schools surveyed. The results indicate that the most consistent factors affecting student performance are characteristics associated with students (innate abilities and home resources). Moreover, the author does not find any consistent relationship between the performance of students and school resources or teacher autonomy, both of which are often advocated in the discussion of education reform.
Elements of a Theory of Simulation

Artificial Life and the more general area of Complex Systems does not have a unified theoretical framework although most theoretical work in these areas is based on simulation. This is primarily due to an insufficient representational power of the classical mathematical frameworks for the description of discrete dynamical systems of interacting objects with often complex internal states.
GALGO: a genetic algorithm decision support tool for complex uncertain systems modeled with Bayesian belief networks

Bayesian belief networks can be used to represent and to reason about complex systems with uncertain, incomplete and conflicting information. Belief networks are graphs encoding and quantifying probabilistic variables. One type of reasoning of interest in diagnosis is called abductive inference (determination of the global most probable system description given the values of any partial subset of variables). In some cases, abductive inference can be performed with exact algorithms using distributed network computations but it is an NP-hard problem and complexity increases drastically with the lxesence of undirected cycles, number of discrete states per variable, and number of variables in the network. This paper describes an approximate method based on genetic algorithms to perform abductive inference in large, multiply connected networks for which complexity is a concern when using most exact methods and for which systematic search methods are not feasible. The theoretical adequacy of the method is discussed and preliminary experimental results are presented.
Second-kind integral solvers for TE and TM problems of diffraction by open arcs

We present a novel approach for the numerical solution of problems of diffraction by open arcs in two dimensional space. Our methodology relies on composition of weighted versions of the classical integral operators associated with the Dirichlet and Neumann problems (TE and TM polarizations, respectively) together with a generalization to the open-arc case of the well known closed-surface Calderon formulae. When used in conjunction with spectrally accurate discretization rules and Krylov-subspace linear algebra solvers such as GMRES, the new second-kind TE and TM formulations for open arcs produce results of high accuracy in small numbers of iterations—for low and high frequencies alike.
Depth extraction from video using non-parametric sampling

We describe a technique that automatically generates plausible depth maps from videos using non-parametric depth sampling. We demonstrate our technique in cases where past methods fail (non-translating cameras and dynamic scenes). Our technique is applicable to single images as well as videos. For videos, we use local motion cues to improve the inferred depth maps, while optical flow is used to ensure temporal depth consistency. For training and evaluation, we use a Kinect-based system to collect a large dataset containing stereoscopic videos with known depths. We show that our depth estimation technique outperforms the state-of-the-art on benchmark databases. Our technique can be used to automatically convert a monoscopic video into stereo for 3D visualization, and we demonstrate this through a variety of visually pleasing results for indoor and outdoor scenes, including results from the feature film Charade.
Ownership concentration, market monitoring and performance: Evidence from the UK, the Czech Republic and Poland

Using data for publicly traded companies from the UK and two transition countries, the Czech Republic and Poland, we analyze the relationship between ownership concentration and performance while also accounting for the effect of hostile takeover threats on this relationship. Some argue that ownership concentration will improve performance by making the owners more willing or able to monitor managers. Others argue that in the presence of efficient markets, market monitoring (via the threat of hostile takeovers) will discipline the managers. Our results show that concentration is insignificant in explaining performance both in the transition countries, where market monitoring is supposedly weak, and in the UK, where market monitoring is supposedly strong.
A Buddhist Colonization?: A New Perspective on the Attempted Alliance of 1910 Between the Japanese Sōtōshū and the Korean Wŏnjong

One of the most infamous events in modern Japanese and Korean Buddhist history was the alliance attempted between the Japanese Sōtōshū (Sōtō Sect) and the Korean Wonjong (Complete Sect) in late 1910, 46 days after Japan annexed Korea. The Japanese Buddhist priests involved have been characterized as colonialists and imperialists trying to conquer Korean Buddhism on behalf of their imperial government while the Korean monks orchestrating the initiative have been cast as traitors, collaborators, and sellers of Korean Buddhism. All the key figures—Takeda (1863–1911), Yi Hoegwang (1862–1933), clergy from the Wonjong and Sōtōshū, and colonial government officials—are portrayed in historiographies as villains. But the politicized narrative of the alliance has neglected two crucial points among others. First, behind Yi and Takeda was a bilingual Korean monk named Kim Yonggi (1878–?) who played a key role in this movement. Second, the Sōtōshū was not enthusiastic about the alliance, which reveals that Takeda’s vision for the alliance was at odds with that of the heads of his sect. This article draws upon these two findings in overlooked primary sources—about the influential players, the Japanese and Korean sects’ conflicted motives, and the governments’ responses—to draw out the complex power relationships and discourses surrounding the attempted alliance.
Investment climate reform - going the last mile : the bulldozer initiative in Bosnia and Herzegovina

The author examines the Bulldozer Initiative in Bosnia and Herzegovina, an innovative reform methodology that successfully overcame the lack of political will and capacity at the government level through a bottom-up approach. Using an innovative grassroots and public awareness methodology, the initiative mobilized the local business community to bulldoze barriers by identifying concrete legislative changes and advocating for their adoption and implementation. By delivering fast results-50 reforms in 150 days-the initiative won the confidence of entrepreneurs and empowered them to institutionalize permanent grassroots reform committees. The force of this lobby group created political will by putting public pressure on the politicians to do their part to enact the reforms. Most important, it carried investment climate reform the last mile by delivering concrete, quantifiable results in all sectors of the economy. Over time, the initiative is establishing a dynamic of reform and public-private partnership that will facilitate the tackling of more complicated structural reforms. Complementing the systemic approach and framework reform efforts of governments and international agencies, competitiveness partnerships mobilize the local business community to catalog concrete problems across the full spectrum of investment climate concerns, pinpoint solutions, campaign for their adoption, and follow up on reform implementation. The author attempts to determine the applicability of competitiveness partnerships to different settings by modeling the interactions between several key success factors, thus providing a pertinent tool for development professionals, government officials, and private sector advocates who wish to establish a renewed implementation dynamic through this kind of results-oriented reform process.
The Impact of Energy Markets on the EU Agricultural Sector

The objective of this study is to analyze the impact of crude oil prices on the EU-27 agricultural sector in an era when the biofuels sector is expanding because of the policy initiatives taken by the EU Commission and member states. To this end, first a baseline is set up for the EU-27 ethanol, grain, and dried distillers grains markets. In the next step, two different scenarios are run. The first scenario incorporates a $10- per-barrel increase in the EU-27 crude oil price with the ethanol import tariffs in place. The second scenario incorporates the same shock with the ethanol import tariffs removed. In the first scenario, higher crude oil prices increase ethanol consumption, production, and therefore grain prices. In the second scenario, the impact of trade liberalisation is larger than the impact of the higher crude oil price. So, grain prices decline in this scenario despite an expansion in ethanol consumption. If there were a high enough crude oil price shock, which would affect the EU-27 ethanol market more than trade liberalisation, the net impact on grain, feed, and food prices from the crude oil price shock would be mitigated by the increased trade from trade liberalisation. The study shows that the impact of energy prices on the EU-27 agricultural sector is increasing with the emergence of the biofuels sector. It also illustrates the importance of trade policy in responding to higher crude oil and grain prices.
Sub-principal homomorphisms in positive characteristic

Let G be a reductive group over an algebraically closed field of characteristic p, and let uG be a unipotent element of order p. Suppose that p is a good prime for G. We show in this paper that there is a homomorphism φ:SL 2/k →G whose image contains u. This result was first obtained by D. Testerman (J. Algebra, 1995) using case considerations for each type of simple group (and using, in some cases, computer calculations with explicit representatives for the unipotent orbits). The proof we give is free of case considerations (except in its dependence on the Bala-Carter theorem). Our construction of φ generalizes the construction of a principal homomorphism made by J.-P. Serre in (Invent. Math. 1996); in particular, φ is obtained by reduction modulo 𝔭 from a homomorphism of group schemes over a valuation ring 𝒜 in a number field. This permits us to show moreover that the weight spaces of a maximal torus of φ(SL 2/k ) on Lie(G) are ``the same as in characteristic 0''; the existence of a φ with this property was previously obtained, again using case considerations, by Lawther and Testerman (Memoirs AMS, 1999) and has been applied in some recent work of G. Seitz (Invent. Math. 2000).
Loss of chromosomal integrity in human mammary epithelial cells subsequent to escape from senescence

The genomic changes that foster cancer can be either genetic or epigenetic in nature. Early studies focused on genetic changes and how mutational events contribute to changes in gene expression. These point mutations, deletions and amplifications are known to activate oncogenes and inactivate tumor suppressor genes. More recently, multiple epigenetic changes that can have a profound effect on carcinogenesis have been identified. These epigenetic events, such as the methylation of promoter sequences in genes, are under active investigation. In this review we will describe a methylation event that occurs during the propagation of human mammary epithelial cells (HMEC) in culture and detail the accompanying genetic alterations that have been observed.
iLearning: The Future of Higher Education? Student Perceptions on Learning with Mobile Tablets

The growing use of mobile technology on college campuses suggests the future of the classroom, including learning activities, research, and even student faculty communications, will rely heavily on mobile technology. Since Fall 2010, an interdisciplinary team of faculty from Indiana University – Purdue University Indianapolis (IUPUI) has experimented with the use of iPads in the classroom. This paper includes the preliminary results of a study on student impressions of mobile technology in the classroom. The paper will report both opportunities and limitations for incorporating mobile technologies in learning environments.
Using Problem Structure for Efficient Clause Learning

DPLL based clause learning algorithms for satisfiability testing are known to work very well in practice. However, like most branch-and-bound techniques, their performance depends heavily on the variable order used in making branching decisions. We propose a novel way of exploiting the underlying problem structure to guide clause learning algorithms toward faster solutions. The key idea is to use a higher level problem description, such as a graph or a PDDL specification, to generate a good branching sequence as an aid to SAT solvers. The sequence captures hierarchical structure that is lost in the CNF translation. We show that this leads to exponential speedups on grid and randomized pebbling problems. The ideas we use originate from the analysis of problem structure recently used in [1] to study clause learning from a theoretical perspective.
Nutrition, Education and Development: The Case of Vitamin D Milk

Micronutrient deficiencies that reduce the health of children risk impeding human capital investments critical for economic development. While the developed world has largely eliminated the most pernicious of these deficiencies, they remain widespread in poorer countries. This study looks at the effects of the introduction of fortified milk, which contributed to the decline of one such micronutrient deficiency in the United States: vitamin D. At the time of vitamin D milk’s introduction in the early 1930s, vitamin D deficiency, manifested most prominently in the form of rickets, affected large numbers of children. Using previously unexamined historical sources, I compile and introduce an original dataset describing the rollout of vitamin D fortified milk across the United States throughout the decade. I then use this dataset to examine the impact of fortified milk on schooling. The gradual expansion of vitamin D milk, along with natural variation in susceptibility to vitamin D deficiency due to geographic and racial factors, permits the identification of fortification’s impact from other regional and temporal trends. Using a difference-in-difference-in-difference (DDD) estimator, I find that the availability of vitamin D milk increased schooling for the group at highest risk for vitamin D deficiency: African-American children from cities with low sunlight. A variety of sensitivity tests supports the validity of the results. They indicate that large scale food fortification initiatives merit further consideration from economists and policy makers concerned with achieving development outcomes.
A sign-changing Liouville equation

We examine periodic solutions to an initial boundary value problem for a Liouville equation with sign-changing weight. A representation formula is derived for both singular and nonsingular boundary data, including data arising from fractional linear maps. In the case of singular boundary data, we study the effects that the induced singularity has on the interior regularity of solutions. Regularity criteria are also found for a generalized form of the equation.
Food regulation and trade under the WTO: ten years in perspective

This article reviews the performance of the World Trade Organization in the oversight of national regulatory decisions affecting agricultural and food trade. A picture emerges of modest international disciplines on the regulatory decisions of sovereign nations and the need for ongoing improvements. A road map to regulations is presented and empirical assessments of the effects of technical regulation on trade are reviewed. Conflicts over sanitary and phytosanitary barriers raised in the relevant World Trade Organization committee are summarized and formal dispute settlement cases involving technical trade barriers are evaluated. Drawing on these reviews, suggestions are made for improving international food regulation.
Using probability-density functions in the framework of evidential reasoning

To develop an approach to utilizing continuous statistical information within the Dempster-Shafer framework, we combine methods proposed by Strat and by Shafer. We first derive continuous possibility and mass functions from probability-density functions. Then we propose a rule for combining such evidence that is simpler and can be computed more efficiently than Dempster's rule. We discuss the relationship between Dempster's rule and our proposed rule for combining evidence over continuous frames.
HRS/NSA 2014 survey of atrial fibrillation and stroke: Gaps in knowledge and perspective, opportunities for improvement

Background The prevalence of atrial fibrillation (AF) is substantial and increasing. Stroke is common in AF and can have devastating consequences. Oral anticoagulants are effective in reducing stroke risk, but are underutilized. Objective We sought to characterize the impact of stroke on AF patients and their caregivers, gaps in knowledge and perspective between physicians and patients, and barriers to effective communication and optimal anticoagulation use. Methods A survey was administered to AF patients with and without history of stroke, caregivers of stroke survivors, and physicians across the range of specialties caring for AF and stroke patients. Results While AF patients (n = 499) had limited knowledge about stroke, they expressed great desire to learn more and take action to reduce their risk. They were often dissatisfied with the education they had received and desired high-quality written materials. Stroke survivors (n = 251) had poor functional outcomes and often underestimated the burden of caring for them. Caregivers (n = 203) also wished they had received more information about reducing stroke risk before their survivor's event. They commonly felt overwhelmed and socially isolated. Physicians (n = 504) did not prescribe anticoagulants as frequently as recommended by guidelines. Concerns about monitoring anticoagulation and patient compliance were commonly reported barriers. Physicians may underestimate patient willingness to take anticoagulants. Conclusion We identified significant knowledge gaps among patients, caregivers, and physicians in relation to AF and stroke. Furthermore, gaps in perspective often lead to suboptimal communication and decision making. Increased education and better communication between all stakeholders are needed to reduce the impact of stroke in AF.
Studies in High Current Density Ion Sources for Heavy Ion Fusion Applications

This dissertation develops diverse research on small (diameter {approx} few mm), high current density (J {approx} several tens of mA/cm{sup 2}) heavy ion sources. The research has been developed in the context of a programmatic interest within the Heavy Ion Fusion (HIF) Program to explore alternative architectures in the beam injection systems that use the merging of small, bright beams. An ion gun was designed and built for these experiments. Results of average current density yield ( ) at different operating conditions are presented for K{sup +} and Cs{sup +} contact ionization sources and potassium aluminum silicate sources. Maximum values for a K{sup +} beam of {approx}90 mA/cm{sup 2} were observed in 2.3 {micro}s pulses. Measurements of beam intensity profiles and emittances are included. Measurements of neutral particle desorption are presented at different operating conditions which lead to a better understanding of the underlying atomic diffusion processes that determine the lifetime of the emitter. Estimates of diffusion times consistent with measurements are presented, as well as estimates of maximum repetition rates achievable. Diverse studies performed on the composition and preparation of alkali aluminosilicate ion sources are also presented. In addition, this work includes preliminary work carried out exploring the viability of an argon plasma ion source and a bismuth metal vapor vacuum arc (MEVVA) ion source. For the former ion source, fast rise-times ({approx} 1 {micro}s), high current densities ({approx} 100 mA/cm{sup 2}) and low operating pressures (< 2 mtorr) were verified. For the latter, high but acceptable levels of beam emittance were measured ({var_epsilon}{sub n} {le} 0.006 {pi} mm {center_dot} mrad) although measured currents differed from the desired ones (I {approx} 5mA) by about a factor of 10.
Trees with convex faces and optimal angles

We consider drawings of trees in which all edges incident to leaves can be extended to infinite rays without crossing, partitioning the plane into infinite convex polygons. Among all such drawings we seek the one maximizing the angular resolution of the drawing. We find linear time algorithms for solving this problem, both for plane trees and for trees without a fixed embedding. In any such drawing, the edge lengths may be set independently of the angles, without crossing; we describe multiple strategies for setting these lengths.
Results from the AGS Booster transverse damper

To reach the design intensity of 1.5/spl times/10/sup 13/ protons per pulse in the AGS Booster, transverse coupled bunch instabilities with an estimated growth rate of 1500s/sup -1/ have to be dampened. A prototype transverse damper has been tested successfully using a one turn digital delay and closed orbit suppression implemented in a programmable gate array. An updated damper, which includes an algorithm to optimize damping for a changing betatron tune, will also be presented. >
A study of B6 stars

A study of the spectra of zeta Draconis (B6 III), beta Sextantis (B6 V), and alpha Leonis (B7 V), was made from high dispersion spectrograms which cover the spectral region 3100 A to 6700 A and from OAO 2 spectral scans covering the spectral region 1100 A to 3600 A. Profiles, equivalent widths and central intensities of many lines in the spectrum of zeta Draconis are presented, as well as for the major lines of beta Sextantis. Alpha Leonis rotates too rapidly for these measurements to be made from high resolution spectrograms. Flux envelopes for zeta Draconis and alpha Leonis, from 1100 A to 6050 A, were derived from published spectrum scans and from new scans obtained with OAO 2. Estimates of the radii and masses of these single stars are presented.
Derivation of the High Field Semiconductor Equations

Electron and hole densities evolve in x — z phase space according to Boltzmann equations. When the mean free path of the particles is short and the electric force on the particles is weak, a well-known expansion (the Hilbert expansion) can be used to solve the Boltzmann equation. This asymptotic solution shows that the spatial density of electrons and holes evolves according to diffusion-drift equations. In fact, the Hilbert expansion leads directly to the Basic Semiconductor (van Roosbroeck) Equations.
The Structure of the Solar Wind at Large Heliocentric Distances: CIRs and their Successors

Co-rotating interaction regions (CIRs) and their associated shock pairs are dominant structures in the solar wind between the heliocentric distances of 2 and 8 AU. At larger heliocentric distances, these structures undergo a qualitative change. Shocks decay to a point where they are often difficult to detect, and may have little influence on the dynamics of the solar wind. Interaction regions spread and merge, though they appear to retain their identity to surprisingly large distances from the Sun. Solar wind and IMF data from the Pioneer 10, Pioneer 11, and Voyager 2 spacecraft were used to conduct a comprehensive survey of CIRs and their successors between heliocentric distances of 1 and 55 AU over the last two solar cycles. The structure of the solar wind varied in a consistent fashion with heliocentric distance. Similar structures were observed at similar heliocentric distances by all three spacecraft during different portions of the solar cycle.
Lower Bounds for Embedding into Distributions over Excluded Minor Graph Families

It was shown recently by Fakcharoenphol et al. [7] that arbitrary finite metrics can be embedded into distributions over tree metrics with distortion O(log n). It is also known that this bound is tight since there are expander graphs which cannot be embedded into distributions over trees with better than Ω(log n) distortion.
Monte Carlo Simulation

Monte Carlo simulation is one of the most important tools in all fields of science. Monte Carlo methods use samples of numbers that appear to be random, although the numbers are generated by deterministic computer algorithms. These “pseudorandom” samples can be used in solving a wide range of problems, including both deterministic problems such as evaluating a definite integral and problems in which there is a random component such as studying and comparing the performance of statistical procedures under various assumptions about the underlying distribution. Keywords: Monte Carlo simulation; quadrature; Monte Carlo test; variance reduction
Flipping Tiles: Concentration Independent Coin Flips in Tile Self-Assembly

In this paper we introduce the robust coin flip problem in which one must design an abstract tile assembly system aTAM system whose terminal assemblies can be partitioned such that the final assembly lies within either partition with exactly probability 1/2, regardless of what relative concentration assignment is given to the tile types of the system. We show that robust coin flipping is possible within the aTAM, and that such systems can guarantee a worst case $$\mathcal {O}1$$O1 space usage. As an application, we then combine our coin-flip system with the result of Chandran, Gopalkrishnan, and Reifi¾?[3] to show that for any positive integer n, there exists a $$\mathcal {O}\log n$$Ologn tile system that assembles a constant-width linear assembly of expected length n that works for all concentration assignments. We accompany our primary construction with variants that show trade-offs in space complexity, initial seed size, temperature, tile complexity, bias, and extensibility, and also prove some negative results. Further, we consider the harder scenario in which tile concentrations change arbitrarily at each assembly step and show that while this is not solvable in the aTAM, this version of the problem can be solved by more exotic tile assembly models from the literature.
Inferring robot task plans from human team meetings: a generative modeling approach with logic-based prior

We aim to reduce the burden of programming and deploying autonomous systems to work in concert with people in time-critical domains, such as military field operations and disaster response. Deployment plans for these operations are frequently negotiated on-the-fly by teams of human planners. A human operator then translates the agreed upon plan into machine instructions for the robots. We present an algorithm that reduces this translation burden by inferring the final plan from a processed form of the human team's planning conversation. Our approach combines probabilistic generative modeling with logical plan validation used to compute a highly structured prior over possible plans. This hybrid approach enables us to overcome the challenge of performing inference over the large solution space with only a small amount of noisy data from the team planning session. We validate the algorithm through human subject experimentation and show we are able to infer a human team's final plan with 83% accuracy on average. We also describe a robot demonstration in which two people plan and execute a first-response collaborative task with a PR2 robot. To the best of our knowledge, this is the first work that integrates a logical planning technique within a generative model to perform plan inference.
Distributed control of the Laplacian spectral moments of a network

It is well-known that the eigenvalue spectrum of the Laplacian matrix of a network contains valuable information about the network structure and the behavior of many dynamical processes run on it. In this paper, we propose a fully decentralized algorithm that iteratively modifies the structure of a network of agents in order to control the moments of the Laplacian eigenvalue spectrum. Although the individual agents have knowledge of their local network structure only (i.e., myopic information), they are collectively able to aggregate this local information and decide on what links are most beneficial to be added or removed at each time step. Our approach relies on gossip algorithms to distributively compute the spectral moments of the Laplacian matrix, as well as ensure network connectivity in the presence of link deletions. We illustrate our approach in nontrivial computer simulations and show that a good final approximation of the spectral moments of the target Laplacian matrix is achieved for many cases of interest.
Virtual moduli cycles and Gromov-Witten invariants of algebraic varieties

We introduce a method of constructing the virtual cycle of any scheme associated with a tangent-obstruction complex. We apply this method to constructing the virtual moduli cycle of the moduli of stable maps from n-pointed genus g curves to any smooth projective variety. As an application, we give an algebraic definition of GW-invariants for any smooth projective variety.
Parallel Wavelet Tree Construction

We present parallel algorithms for wavelet tree construction with polylogarithmic depth, improving upon the linear depth of the recent parallel algorithms by Fuentes-Sepulveda et al. We experimentally show that on a 40-core machine with two-way hyper-threading, we outperform the existing parallel algorithms by 1.3--5.6x and achieve up to 27x speedup over the sequential algorithm on a variety of real-world and artificial inputs. Our algorithms show good scalability with increasing thread count, input size and alphabet size. We also discuss extensions to variants of the standard wavelet tree.
Filter Diagonalization Methods for Time-Domain Signals

The sections in this article are 1 Introduction 2 Formulation of the Problems 3 Parameter and Spectral Estimation by 1D FDM 4 mD FDM 5 Practical Considerations 6 Selected Applications 7 Remaining Problems 8 Acknowledgements 9 Biographical Sketches
Evolution of the X-ray properties of clusters of galaxies.

The evolution of X-ray properties of clusters of galaxies with cosmic epoch puts constraints on the primordial density fluctuation spectrum. Luminosity evolution is quite well etablished. Evolution of the gas temperature is also seen but at low confidence.
Stage level, volume and time-frequency information content of Lake Tana using stochastic and wavelet analysis methods

Lake Tana is the largest fresh water body situated in the north-western highlands of Ethiopia. In addition to its ecological services, it serves for local transport, electric power generation, fishing, recreational purposes, and source of dry season irrigation water supply. Evidence shows that the lake has dried at least once at about 15,000–17,000 before present owing to a combination of high evaporation and low precipitation events. Past attempts to understand and simulate historical fluctuation of Lake Tana based on simplistic water balance approach of inflow, outflow, and storage have failed to capture well-known events of drawdown and rise of the lake that have happened in the last 44 years. This study tested different stochastic methods of lake level and volume simulation for supporting Lake Tana operational planning decision support. Three stochastic methods (perturbations approach, Monte Carlo methods, and wavelet analysis) were employed for lake level and volume simulation, and the results were compared with the stage level measurements. Forty-four years of daily, monthly, and mean annual lake level data have shown a Gaussian variation with goodness of fit at 0.01 significant levels of the Kolmogorov–Smirnov test. The stochastic simulations predicted the lake stage level of the 1972, 1984, and 2002/2003 historical droughts 99% of the time. The information content (frequency) of fluctuation of Lake Tana for various periods was resolved using Wigner's Time-Frequency Decomposition method. The wavelet analysis agreed with the perturbations and Monte Carlo simulations resolving the time (1970s, 1980s, and 2000s) in which low frequency and high spectral power fluctuation has occurred. The Monte Carlo method has shown its superiority for risk analysis over perturbation and deterministic method whereas wavelet analysis reconstructed historical record of lake stage level at daily and monthly time scales. Copyright © 2012 John Wiley & Sons, Ltd.
Fourteen months of observations of the possible super-Chandrasekhar mass Type Ia Supernova 2009dc

In this paper, we present and analyse optical photometry and spectra of the extremely luminous and slowly evolving Type Ia supernova (SN Ia) 2009dc, and offer evidence that it is a super-Chandrasekhar mass (SC) SN Ia and thus has a SC white dwarf (WD) progenitor. Optical spectra of SN 2007if, a similar object, are also shown. SN 2009dc had one of the most slowly evolving light curves ever observed for a SN Ia, with a rise time of ~23 d and Δm 15 (B) = 0.72 mag. We calculate a lower limit to the peak bolometric luminosity of ~2.4 x 10 43 erg s -1 , though the actual value is likely almost 40 per cent larger. Optical spectra of SN 2009dc and SN 2007if obtained near maximum brightness exhibit strong C II features (indicative of a significant amount of unburned material), and the post-maximum spectra are dominated by iron-group elements (IGEs). All of our spectra of SN 2009dc and SN 2007if also show low expansion velocities. However, we see no strong evidence in SN 2009dc for a velocity 'plateau' near maximum light like the one seen in SN 2007if. The high luminosity and low expansion velocities of SN 2009dc lead us to derive a possible WD progenitor mass of more than 2 M ⊙ and a 56 Ni mass of about 1.4-1.7 M ⊙ . We propose that the host galaxy of SN 2009dc underwent a gravitational interaction with a neighbouring galaxy in the relatively recent past. This may have led to a sudden burst of star formation which could have produced the SC WD progenitor of SN 2009dc and likely turned the neighbouring galaxy into a 'post-starburst galaxy'. No published model seems to match the extreme values observed in SN 2009dc, but simulations do show that such massive progenitors can exist (likely as a result of the merger of two WDs) and can possibly explode as SC SNe Ia.
Controls on Soil Organic Carbon and Nitrogen in Inner Mongolia, China: A Cross-Continental Comparison of Temperate Grasslands

[1] Most global ecosystem models assume that controls over soil organic matter are alike in climatically similar regions. In this study, we tested the generality of controls over soil organic carbon (SOC) and soil organic nitrogen (SON) in temperate grasslands. We measured organic matter pools in Inner Mongolia, China, along the Northeast China Transect, and analyzed the relationship of SOC and SON to climate, soil texture, and land use variables. We then compared our data to values simulated by a regression model developed in the U.S. Great Plains and also to Century model simulations. We found that, as in the U.S. Great Plains, climate and soil texture variables could explain a large proportion of variation in observed SOC and SON, but a regression model developed in the Great Plains overestimated SOC and underestimated SON in Inner Mongolia. Using Century, we found that simulated SOC and SON values were sensitive to both inclusion of altered land use and changes in N deposition and that the model that best fit our data included higher-intensity grazing and N deposition values higher than that in the Great Plains. This model also produced aboveground net primary production (ANPP) values comparable with values observed in the literature for Inner Mongolian grasslands, but these values were higher than ANPP predicted by previously published regression models. These results suggest that different controls over SOC and SON cycling in Inner Mongolia may affect our ability to predict SOC and SON pool sizes using relationships in other regional models.
A Matter of Principle: The Principles of Quantum Theory, Dirac's Equation, and Quantum Information

This article is concerned with the role of fundamental principles in theoretical physics, especially quantum theory. The fundamental principles of relativity will be addressed as well, in view of their role in quantum electrodynamics and quantum field theory, specifically Dirac’s work, which, in particular Dirac’s derivation of his relativistic equation of the electron from the principles of relativity and quantum theory, is the main focus of this article. I shall also consider Heisenberg’s earlier work leading him to the discovery of quantum mechanics, which inspired Dirac’s work. I argue that Heisenberg’s and Dirac’s work was guided by their adherence to and their confidence in the fundamental principles of quantum theory. The final section of the article discusses the recent work by D’Ariano and coworkers on the principles of quantum information theory, which extend quantum theory and its principles in a new direction. This extension enabled them to offer a new derivation of Dirac’s equations from these principles alone, without using the principles of relativity.