cssi/SciSciGPT-SciSciNet huggingface dataset:
Numerical simulations of convection in Europa's ice shell: Implications for surface features

[1] Europa's icy surface displays numerous small (5- to 30-km-diameter) pits, spots, and uplifts that have been suggested to result from convection in the ice shell. To test this hypothesis, we present numerical simulations of convection in Europa's ice shell, including temperature-dependent viscosity and tidal heating. Ice shells 15 and 50 km thick are considered, consistent with several estimates of the shell thickness on Europa. The convection produces deep pits (consistent with some of the observed features) when the lithospheric viscosity is 103–105 times greater than that of the underlying ice, but greater viscosity contrasts lead to topography insufficient to explain the observed pits. If ductile creep is the only deformation mechanism, these results imply that convection cannot produce the observed pits and uplifts because in that case the predicted surface viscosity exceeds that of the warm underlying ice by at least a factor of 1010. However, the strength of Europa's surface may be low enough for plastic deformation to play a role in the convection, opening the possibility that convection could produce some of Europa's pits. For plausible viscosities (1013 Pa s at the melting temperature), the pits are 100–300 m deep and 10–20 km in diameter; greater or lesser viscosities lead to wider or narrower pits, respectively. None of our simulations produced isolated uplifts of any diameter, however, so these probably formed by another mechanism. The convection can induce surface stresses >1 bar, which exceeds the inferred strength of Europa's crust and indicates the likelihood of surface disruption. The maximum tidal heat fluxes that can be transported by convection at realistic ice viscosities are 0.05–0.07 W m−2.
Iterative restoration of fast-moving objects in dynamic image sequences

If a point on an object passes over two or more photoreceptors during image acquisition, a blur will occur. Under these conditions, an object or scene is said to move fast relative to the camera's ability to capture the motion. In this work, we consider the iterative restoration of images blurred by distinct, fast moving objects in the frames of a (video) image sequence. Even in the simplest case of fast object motion, the degradation is spatially variant with respect to the image scene. Rather than segmenting the image into regions where the degradation can be considered space invariant, we allow the blur to vary at each pixel and perform iterative restoration. Our approach requires complete knowledge of the blur point spread function (PSF) to restore the scene. The blur of fast moving object in a single frame is under specified. With the appropriate assumptions, an estimate of the blur PSF can be specified to within a constant scaling factor using motion information provided by a displacement vector field (DVF). A robust iterative restoration approach is followed which allows for the incorporation of prior knowledge of the scene structure into the algorithm to facilitate the restoration of difficult scenes. A bilinear approximation to the continuous PSF derived from the motion estimate is proposed to obtain results for real and synthetic sequences. We found this approach suitable for restoring motion degradations in a wide range of digital video applications. The results of this work reinforced the well known flexibility of the iterative approach to restoration and its application as an off-line image sequence restoration method.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A perspective on multiaccess channels

The information theoretic approach and the collision resolution approach to multiaccess channels are reviewed in terms of the underlying communication problems that both are modeling. Some perspective on the strengths and weakness of these approaches is given, and the need of a more combined approach focused on coding and decoding techniques is argued.
Existence of Dicritical Divisors Revisited

We characterize the dicriticals of special pencils. We also initiate higher dimensional dicritical theory.
Design study of a microwave driver for a relativistic klystron two-beam accelerator

In two-beam accelerators, the reacceleration of a modulated drive beam can enable high conversion efficiency of electron beam energy to rf energy. However, the stability issues involved with the transport of high current electron beams through rf extraction structures and induction accelerator cells are critical. We report on theoretical studies and computer simulations of a two-beam accelerator design using traveling-wave extraction structures. Specific issues addressed include regenerative and cumulative transverse instabilities. >
Lessons from participatory design with adolescents on the autism spectrum

Participatory user interface design with adolescent users on the autism spectrum presents a number of unique challenges and opportunities. Through our work developing a system to help autistic adolescents learn to recognize facial expressions, we have learned valuable lessons about software and hardware design issues for this population. These lessons may also be helpful in assimilating iterative user input to customize technology for other populations with special needs.
In-network monitoring and control policy for DVFS of CMP networks-on-chip and last level caches

In chip design today and for a foreseeable future, the last-level cache and on-chip interconnect is not only performance critical but also a substantial power consumer. This work focuses on employing dynamic voltage and frequency scaling (DVFS) policies for networks-on-chip (NoC) and shared, distributed last-level caches (LLC). In particular, we consider a practical system architecture where the distributed LLC and the NoC share a voltage/frequency domain that is separate from the core domain. This architecture enables the control of the relative speed between the cores and memory hierarchy without introducing synchronization delays within the NoC. DVFS for this architecture is more complex than individual link/core-based DVFS since it involves spatially distributed monitoring and control. We propose an average memory access time (AMAT)-based monitoring technique and integrate it with DVFS based on PID control theory. Simulations on PARSEC benchmarks yield a 27p energy savings with a negligible impact on system performance.
Database Development Methodology and Organization

Database development methodologies are a subset of full life cycle methodologies that can be used to build databases from the requirements phase through to implementation. Database development methodologies that are iterative, with extensive user involvement and that are packaged with reusable templates or deliverables offer a good opportunity for success. When selecting one for an organization, find one that is simple to learn, simple to use, and electronically deployed for quick access by project teams.
Coordinated Control and Range Imaging for Mobile Manipulation

Mobile manipulators currently deployed for explosive ordinance disposal are typically controlled via crude forms of teleoperation.Manipulator joints are actuated individually in joint space, making precise motions in state space difficult. Scene understanding is limited, as monocular cameras provide little (if any) depth information. Furthermore, the operator must manually coordinate the manipulator articulation with the positioning of the mobile base. These limitations place greater demands on the operator, decrease task efficiency and can increase exposure in dangerous environments.
Block Kaczmarz Method with Inequalities

The randomized Kaczmarz method is an iterative algorithm that solves systems of linear equations. Recently, the randomized method was extended to systems of equalities and inequalities by Leventhal and Lewis. Even more recently, Needell and Tropp provided an analysis of a block version of this randomized method for systems of linear equations. This paper considers the use of a block type method for systems of mixed equalities and inequalities, bridging these two bodies of work. We show that utilizing a matrix paving over the equalities of the system can lead to significantly improved convergence, and prove a linear convergence rate as in the standard block method. We also demonstrate that using blocks of inequalities offers similar improvement only when the system satisfies a certain geometric property. We support the theoretical analysis with several experimental results.
On the evolution of optimizing behavior

Abstract We investigate whether replicator dynamics justify “survival of the fittest” when players inherit pure strategies, mixed strategies, or rules for choosing strategies. A strategy that never is a best reply can survive replicator dynamics if only pure strategies are heritable, but only rationalizable strategies survive if mixed strategies are heritable. Now suppose agents can inherit the rule of choosing a best reply to the last period's population, rather than inheriting a strategy itself. Such optimizers need not drive out players who inherit a dominated strategy. If we interpret replicator dynamics as a learning process, this means that non-optimizing behavior can survive.
THE DUOPOLISTIC FIRM WITH ENDOGENOUS RISK CONTROL CASE OF PERSUASIVE ADVERTISING AND PRODUCT DIFFERENTIATION

In this paper, a two-period game is constructed, where duopoly firms choose advertising strategies in the first period and compete in price or quantity in the second period by maximizing the value of firm equity. Using certainty equivalence, we demonstrate the impacts of uncertainty and modes of competition on duopoly firms' optimal pricing, production, and advertising strategies. Equilibrium price and quantity outcomes emerge as significantly different from the standard industrial organization model of profit maximization. It turns out that the common measurement of market power, the Lerner index, is generally mis-stated. In contrast to the literature, we also find that firms will optimally switch from quantity to price competition either when advertising costs are low, demand is high, or if idiosyncratic risk is reduced. A series of simulations confirm these findings.
Synthetic chemistry fuels interdisciplinary approaches to the production of artemisinin.

Covering: up to 2014 In the developing world, multi-drug resistant malaria caused by the parasite Plasmodium falciparum is an epidemic that claims the lives of 1–3 million people per year. Artemisinin, a naturally occurring small molecule that has seen little resistance from malarial parasites, is a valuable weapon in the fight against this disease. Several easily accessible artemisinin derivatives, including artesunate and artemether, display potent antimalarial activity against drug-resistant malaria strains; however, the global supply of artemisinin from natural sources alone remains highly inconsistent and unreliable. As a result, several approaches to artemisinin production have been developed, spanning areas such as total synthesis, flow chemistry, synthetic biology, and semi-synthesis. This review highlights achievements in all areas, in addition to the interplay between synthetic biology and synthetic chemistry that has fueled the recent industrial-scale production of artemisinin.
A critical analysis of the feasibility of pure strain-actuated giant magnetostrictive nanoscale memories

Concepts for memories based on the manipulation of giant magnetostrictivenanomagnets by stress pulses have garnered recent attention due to their potential for ultra-low energy operation in the high storage density limit. Here, we discuss the feasibility of making such memories in light of the fact that the Gilbert damping of such materials is typically quite high. We report the results of numerical simulations for several classes of toggle precessional and non-toggle dissipative magnetoelastic switching modes. Material candidates for each of the several classes are analyzed and forms for the anisotropy energy density and ranges of material parameters appropriate for each material class are employed. Our study indicates that the Gilbert damping as well as the anisotropy and demagnetization energies are all crucial for determining the feasibility of magnetoelastic toggle-mode precessional switching schemes. The roles of thermal stability and thermal fluctuations for stress-pulse switching of giant magnetostrictivenanomagnets are also discussed in detail and are shown to be important in the viability, design, and footprint of magnetostrictive switching schemes.
High energy leptons from muons in transit

The differential energy distribution for electrons and taus produced from lepton pair production from muons in transit through materials is numerically evaluated. We use the differential cross section to calculate underground lepton fluxes from an incident atmospheric muon flux, considering contributions from both conventional and prompt fluxes. An approximate form for the charged current differential neutrino cross section is provided and used to calculate single lepton production from atmospheric neutrinos. We compare the fluxes of underground leptons produced from incident muons with those produced from incident neutrinos and photons from muon bremsstrahlung. We discuss their relevance for underground detectors.
THE ROLE OF RETIREE HEALTH INSURANCE IN THE EMPLOYMENT BEHAVIOR OF OLDER MEN

Using data from the Health and Retirement Survey, we estimate preference and expectations parameters of a structural model of the employment and medical care decisions of older men in order to evaluate the role of health insurance. The budget constraint incorporates detailed cost-sharing characteristics of private health insurance and Medicare as well as rules and requirements associated with Social Security and private pensions. Simulations imply that changes in health insurance, including access and restrictions to retiree health insurance and Medicare, have a modest impact on employment behavior among older males, with the greatest effect on men in bad health.
Submillimeter-wave detection with superconducting tunnel diodes

The review presents a theoretical framework for understanding submillimeter detection using an optical photodiode theory. Both gain and noise in the superconductor-insulator-superconductor (SIS) mixer are described in terms of mixing on a photodiode. The role of impedance matching in the proper design of an SIS mixer is described. A variety of methods for achieving good impedance match at submillimeter frequencies are presented. The state of the submillimeter SIS mixer art as practiced in a variety of laboratories is described and summarized. >
Breakup of electrified jets

Breakup of electrified jets is important in applications as diverse as electrospraying, electroseparations and electrospray mass spectrometry. Breakup of a perfectly conducting, incompressible Newtonian liquid jet surrounded by a passive insulating gas that is stressed by a radial electric field is studied by a temporal analysis. An initially quiescent jet is subjected to axially periodic shape perturbations and the ensuing dynamics are followed numerically until pinch-off by both a three-dimensional but axisymmetric (two-dimensional) and a one-dimensional slender-jet algorithm. Results computed with these algorithms are verified against predictions from linear theory for short times. Breakup times, ratios of the sizes of the primary to satellite drops formed at pinch-off, and the Coulombic stability of these drops are reported over a wide range of electrical Bond numbers, NE (ratio of electric to surface tension force), Ohnesorge numbers, NOh (ratio of viscous to surface tension force), and disturbance wavenumbers, k. Effect of surface charge on interface overturning is investigated. Furthermore, the influence of electrostatic stresses on the dynamics of pinch-off and the mechanisms of satellite drop formation is also addressed.
Factor Endowment, Structural Coherence, and Economic Growth

This paper studies the linkage between structural coherence and economic growth. Structural coherence is defined as the degree that a country's industrial structure optimally reflects its factor endowment fundamentals. The paper found that at least for the overall capital, the shares of capital intensive industries were significantly bigger with higher initial capital endowment and faster capital accumulation. Moreover, there is a positive relationship between a country's aggregate output growth and the degree of structural coherence. Quantitatively, the structural coherence with respect to the overall capital explains about 30% of the growth differential among sample countries.
Demutualization: Determinants and consequences of the mutual holding company choice

We investigate the determinants and consequences of the mutual holding company (MHC) structure that allows mutual thrifts to issue stock to outside shareholders while maintaining the mutual form. Capital constrained firms with greater profit opportunities are more likely to choose a full demutualization; demonstrating that the MHC choice can be used to control for over- and under-investment costs. During periods of greater regulatory constraints, MHC firms have lower offer-day returns than full demutualizations. MHC firms are also less likely to be acquired, as the MHC structure provides protection from the market for corporate control. Demonstrating a clear preference by minority shareholders for the elimination of the MHC structure, the announcement of a second-stage conversion generates a 12% return.
Differentiability implies continuity in neuronal dynamics

Recent work has identified nonlinear deterministic structure in neuronal dynamics using periodic orbit theory. Troublesome in this work were the significant periods of time where no periodic orbits were extracted — “dynamically dark” regions. Tests for periodic orbit structure typically require that the underlying dynamics are differentiable. Since continuity of a mathematical function is a necessary but insufficient condition for differentiability, regions of observed differentiability should be fully contained within regions of continuity. We here verify that this fundamental mathematical principle is reflected in observations from mammalian neuronal activity. First, we introduce a null Jacobian transformation to verify the observation of differentiable dynamics when periodic orbits are extracted. Second, we show that a less restrictive test for deterministic structure requiring only continuity demonstrates widespread nonlinear deterministic structure only partially appreciated with previous approaches. © 2001 Published by Elsevier Science B.V.
Optimal transmission switching — Sensitivity analysis and extensions

In this paper, we continue to analyze optimal dispatch of generation and transmission topology to meet load as a mixed integer program (MIP) with binary variables representing the state of the transmission element (line or transformer). Previous research showed a 25% savings by dispatching the IEEE 118 bus test case. This paper is an extension of that work. It presents how changing the topology affects nodal prices, load payment, generation revenues, cost, and rents, congestion rents, and flowgate prices. Results indicate that changing the topology to cut costs typically results in lower load payments and higher generation rents for this network. Computational issues are also discussed.
Actions and Identities on Set Partitions

A labeled set partition is a partition of a set of integers whose arcs are labeled by nonzero elements of an abelian group A. Inspired by the action of the linear characters of the unitriangular group on its supercharacters, we dene a group action of A n on the set of A-labeled partitions of an (n + 1)-set. By investigating the orbit decomposition of various families of set partitions under this action, we derive new combinatorial proofs of Coker’s identity for the Narayana polynomial and its type B analogue, and establish a number of other related identities. In return, we also prove some enumerative results concerning Andr e and Neto’s supercharacter theories of type B and D.
Well-being during a time of change : Timor-Leste on the path to independence

Countries undergoing fundamental economic and political transformations might experience differential adjustments in material well-being and empowerment. The author evaluates self-rated welfare and power changes in Timor-Leste covering the period prior to the 1999 referendum on independence from Indonesia to the eve of independence in end 2001. Drawing on the first nationally representative household survey and village census, he shows how subjective, objective, and recall information can be combined to provide a rich profile of trends in well-being from the pre- to post-conflict stage. The authors analysis shows that changes in self-rated welfare and power broadly corresponded to changes recorded by objective indicators. While economic well-being improved little, empowerment increased dramatically. The changes were not uniform across the population but some groups benefited more than others. The evidence for Timor-Leste is consistent with these hypotheses: a) Economic resources increase welfare, and more than power; b) Social resources increase power, and more than welfare; c) Welfare winners have low initial economic resources; d) Power winners have high social resources; and e) Economic shocks reduce welfare and power, but welfare more than power.
Optimality Study of Logic Synthesis for LUT-Based FPGAs

Field-programmable gate-array (FPGA) logic synthesis and technology mapping have been studied extensively over the past 15 years. However, progress within the last few years has slowed considerably (with some notable exceptions). It seems natural to then question whether the current logic-synthesis and technology-mapping algorithms for FPGA designs are producing near-optimal solutions. Although there are many empirical studies that compare different FPGA synthesis/mapping algorithms, little is known about how far these algorithms are from the optimal (recall that both logic-optimization and technology-mapping problems are NP-hard, if we consider area optimization in addition to delay/depth optimization). In this paper, we present a novel method for constructing arbitrarily large circuits that have known optimal solutions after technology mapping. Using these circuits and their derivatives (called Logic synthesis Examples with Known Optimal (LEKO) and Logic synthesis Examples with Known Upper bounds (LEKU), respectively), we show that although leading FPGA technology-mapping algorithms can produce close to optimal solutions, the results from the entire logic-synthesis flow (logicoptimization+mapping) are far from optimal. The LEKU circuits were constructed to show where the logic synthesis flow can be improved, while the LEKO circuits specifically deal with the performance of the technology mapping. The best industrial and academic FPGA synthesis flows are around 70 times larger in terms of area on average and, in some cases, as much as 500 times larger on LEKU examples. These results clearly indicate that there is much room for further research and improvement in FPGA synthesis
Are there real effects of licensing on academic research? A life cycle view

Abstract Do financial returns to licensing divert faculty from basic research? In a life cycle model in which faculty can conduct basic and/or applied research (the latter can be licensed) licensing increases applied relative to basic effort. However, leisure falls so basic research need not suffer. If applied effort also leads to publishable output, then research output and stock of knowledge are higher with licensing than without. In a tenure system licensing has a positive effect on research output unless license incentives are high. Overall results suggest a positive impact of tenure on research output over the life cycle.
On geometric path query problems

In this paper, we study several geometric path query problems. Given a scene of disjoint polygonal obstacles with totally n vertices in the plane, we construct efficient data structures that enable fast reporting of an "optimal" obstacle-avoiding path (or its length, cost, directions, etc) between two arbitrary query points s and t that are given in an on-line fashion. We consider geometric paths under several optimality criteria: Lm length, number of edges (called links), monotonicity with respect to a certain direction, and some combinations of length and links. Our methods are centered around the notion of gateways, a small number of easily identified points in the plane that control the paths we seek. We give efficient solutions for several special cases based upon new geometric observations. We also present solutions for the general cases based upon the computation of the minimum size visibility polygon for query points.
Limited Feedback Beamforming Over Temporally-Correlated Channels

Feedback of quantized channel state information (CSI), called limited feedback, enables transmit beamforming in multiple-input-multiple-output (MIMO) wireless systems with a small amount of overhead. Due to its efficiency, beamforming with limited feedback has been adopted in several wireless communication standards. Prior work on limited feedback commonly adopts the block fading channel model where temporal correlation in wireless channels is neglected. In this paper, we consider temporally correlated channels and design single-user transmit beamforming with limited feedback. Analytical results concerning CSI feedback are derived by modeling quantized CSI as a first-order finite-state Markov chain. These results include the information rate of the CSI quantizer output, the bit rate a CSI feedback channel is required to support, and the effect of feedback delay on throughput. In particular, based on the theory of Markov chain convergence rate, feedback delay is proved to reduce the throughput gain due to CSI feedback at least exponentially. Furthermore, an algorithm is proposed for CSI feedback compression in time. Combining the results in this work leads to a new method for designing limited feedback beamforming as demonstrated by a design example.
A comparative study of municipal performance measurement systems in Ontario and Quebec, Canada

This paper is an analysis of the municipal performance measurement systems in Ontario and Quebec affecting about 2/3 of all Canadian citizens. The article describes these two systems; how the systems came to be, their goals, types of indicators, accountability and reporting requirements, data analysis, and requirements for performance reporting. After a discussion of the broad literature related to municipal performance measurement both globally and in Canada, the two cases are described in terms of political background, system components, measurement requirements, and reporting requirements. Analysis of these systems then follows comparing the two systems which are similar but unique in significant ways. This analysis has implications for these provinces as well as other jurisdictions with, or considering, mandated municipal performance systems.
Synthesis of Benzyloxybromobenzonitriles

Abstract The synthesis of four new benzyloxybromobenzonitriles including: 2‐benzyloxy‐4‐bromobenzonitrile (3), 3‐benzyloxy‐4‐bromobenzonitrile (7), 5‐benzyloxy‐2‐bromobenzonitrile (11) and 3‐benzyloxy‐2‐bromobenzonitrile (12) is reported.
Estimating Heterogeneity in the Benefits of Medical Treatment Intensity

Abstract We exploit increases in postpartum length of stay generated by legislative changes in the late 1990s to identify the impact of greater hospital care on the health of newborns. Using all births in California over the 1995–2000 period, two-stage least-square estimates show that increased treatment intensity had a modest impact on readmission probabilities for the average newborn. Allowing the treatment effect to vary by two objective measures of medical need demonstrates that the law had large impacts for those with the greatest likelihood of a readmission. The results suggest that the returns to average and marginal patients vary considerably in this context.
Cofinancing to Manage Risk in the Motion Picture Industry

Cofinancing is a term used in the movie industry to describe films for which multiple firms share the cost of production and revenues. We find that one-third of movies produced by major studios between 1987 and 2000 are cofinanced. Anecdotal evidence strongly indicates that cofinancing is for the purpose of risk management. However, the major studios are publicly traded firms, which allows investors to make their own diversification decisions, leading us to question the importance of cofinancing for risk management. Contrary to industry-claims, we find that cofinancing decisions are unrelated to the distribution of individual movie returns—studios do not appear to cofinance relatively risky films. But we do find that studios are more likely to cofinance movies that account for a large fraction of their total annual production budget, which reduces portfolio risk via the law of large numbers. Toward an alternative explanation for cofinancing, we also find that cofinancing between two major studios impacts the release dates of their other movies.
The Role of Speculation and Information in the Early Evolution of the United States Ostrich Industry: An Industry Case Study

The U.S. ostrich industry was introduced in the 1980s and experienced rapid expansion in the late 1980s and early 1990s. Breeding stock prices rose rapidly and subsequently plummeted during 1993–1995. High prices are to be expected in the introductory stage of an industry. However, the magnitude of prices in the ostrich industry is likely due to overestimates of ostrich productivity and future demand for ostrich products, as well as speculation in the ostrich market. This paper discusses the evolution of the industry from the mid-1980s to the present.
Place Matters: The Significance of Place Attachments for Children's Well-Being

Whilst the social work literature rightly pays considerable attention to the importance for children's development and well-being of their attachments to people, there has been virtually no consideration of the role which is also played by their attachments to place. Drawing on research from fields such as human geography and environmental psychology, the significance of children's place attachments for the development of their identity, security and sense of belonging is examined. Evidence is also presented about the ‘shrinking world of childhood’, in which children's independent access to their surroundings is becoming ever more restricted as a result of parental fears, and the implications of this trend for the development of children's place attachments. Government policy relevant to these issues, including strategies designed to develop more ‘child-friendly communities’, is critically reviewed, together with evidence-based practice recommendations designed to improve the well-being of looked after children by promoting their place attachments.
Pairing in the Bogoliubov-de Gennes Equations

It is shown that the Bogoliubov–de Gennes equations pair the electrons in states which are linear combinations of the normal states. Accordingly, the BCS-like reduction procedure is required to choose a correct pairing. For a homogeneous system, we point out that the kernel of the self-consistency equation derived from the Bogoliubov–de Gennes equations needs to be constrained by the BCS pairing condition. In the presence of ordinary impurities, on the other hand, the Bogoliubov–de Gennes equations should be supplemented by Anderson's pairing condition to obtain the correct vacuum state by the corresponding unitary transformation. This results in localization correction to the phonon-mediated interaction.
A spectral method for parabolic differential equations

We present a spectral method for parabolic partial differential equations with zero Dirichlet boundary conditions. The region ? for the problem is assumed to be simply-connected and bounded, and its boundary is assumed to be a smooth surface. An error analysis is given, showing that spectral convergence is obtained for sufficiently smooth solution functions. Numerical examples are given in both ?2 and ?3.
DETECTION OF GRAVITATIONAL WAVES FROM INFLATION

Recent measurements of temperature fluctuations in the cosmic microwave background (CMB) indicate that the Universe is flat and that large-scale structure grew via gravitational infall from primordial adiabatic perturbations. Both od these observations seem to indicate that we are on the right track with inflation. But what is the new physics responsible for inflation? This question can be answered with observations of the polarization of the CMB. Inflation predicts robustly the existence of a stochastic background of cosmological gravitational waves with an amplitude proportional to the square of the energy scale of inflation. This gravitational-wave background induces a unique signature in the polarization of the CMB. If inflation took place at an energy scale much smaller than that of grand unification, then the signal will be too small to be detectable. However, if inflation had something to do with grand unification or Planck-scale physics, then the signal is conceivably detectable in the optimistic ...
Aircraft Turbofan Engine Health Estimation Using Constrained Kalman Filtering

ABSTRACTKalman ¯lters are often used to estimate the state variablesof a dynamic system. However, in the application of Kalman¯lters some known signal information is often either ignored ordealt with heuristically. For instance, state variable constraints(which may be based on physical considerations) are often ne-glected because they do not ¯t easily into the structure of theKalman ¯lter. This paper develops an analytic method of in-corporating state variable inequality constraints in the Kalman¯lter. The resultant ¯lter is a combination of a standard Kalman¯lter and a quadratic programming problem. The incorporationof state variable constraints increases the computational e®ort ofthe ¯lter but signi¯cantly improves its estimation accuracy. Theimprovement is proven theoretically and shown via simulationresults obtained from application to a turbofan engine model.This model contains 16 state variables, 12 measurements, and 8component health parameters. It is shown that the new algo-rithms provide improved performance in this example over un-constrained Kalman ¯ltering.INTRODUCTION
Joining of carbon-carbon composites by graphite formation

Joining of carbon-carbon (C-C) composites by graphite formation, using manganese, magnesium, and aluminum interlayers, has been investigated. The process involved the formation of a metal carbide by chemical reaction between the metal interlayer and the composite, followed by the decomposition of the carbide and evaporation of the metal at elevated temperatures. The maximum bonding temperature in these experiments was 2,200 C. Bonding of composite specimens occurred when manganese or a powder mixture of aluminum and graphite was used as interlayers. Attempts to join C-C pieces using a magnesium interlayer were unsuccessful. The double notch shear strengths of the joints produced using Mn interlayers were very low and ranged from 0.15 to 1.61 MPa at test temperatures of 1,200 and 1,400 C. The interlayer, after completion of the joining operation, consisted, in most cases, only of graphite. The joints produced with aluminum plus graphite interlayers were even weaker, with strength values of 0.11 MPa or less. The presence of aluminum could be detected in some of these joints, suggesting incomplete dissociation of Al[sub 4]C[sub 3] at the maximum bonding temperature of 2,150 C.
The link concordance invariant from Lee homology

We use the knot homology of Khovanov and Lee to construct link concordance invariants generalizing the Rasmussen s-invariant of knots. The relevant invariant for a link is a filtration on a vector space of dimension 2 jLj . The basic properties of the s-invariant all extend to the case of links; in particular, any orientable cobordism � between links induces a map between their corresponding vector spaces which is filtered of degree �(�). A corollary of this construction is that any component-preserving orientable cobordism from a Kh-thin link to a link split into k components must have genus at least b k c. In particular, no quasi-alternating link is concordant to a split link.
A Porism Concerning Cyclic Quadrilaterals

We present a geometric theorem on a porism about cyclic quadrilaterals, namely, the existence of an infinite number of cyclic quadrilaterals through four fixed collinear points once one exists. Also, a technique of proving such properties with the use of pseudounitary traceless matrices is presented. A similar property holds for general quadrics as well as for the circle.
Regularity of Intersection Local Times of Fractional Brownian Motions

Let B αi be an (Ni ,d) -fractional Brownian motion with Hurst index αi (i = 1, 2), and let B α1 and B α2 be independent. We prove that, if N1 α1 + N2 α2 >d , then the intersection local times of B α1 and B α2 exist, and have a continuous version. We also establish Holder conditions for the intersection local times and determine the Hausdorff and packing dimensions of the sets of intersection times and intersection points. One of the main motivations of this paper is from the results of Nualart and Ortiz- Latorre (J. Theor. Probab. 20:759-767, 2007), where the existence of the intersection local times of two independent (1 ,d) -fractional Brownian motions with the same Hurst index was studied by using a different method. Our results show that anisotropy brings subtle differences into the analytic properties of the intersection local times as well as rich geometric structures into the sets of intersection times and intersection points.
The production, spectrum and evolution of cosmic strings in brane inflation

Brane inflation in superstring theory predicts that cosmic strings (but not domain walls or monopoles) are produced towards the end of the inflationary epoch. Here, we discuss the production, the spectrum and the evolution of such cosmic strings, properties that differentiate them from those coming from an abelian Higgs model. As D-branes in extra dimensions, some type of cosmic strings will dissolve rapidly in spacetime, while the stable ones appear with a spectrum of cosmic string tensions. Moreover, the presence of the extra dimensions reduces the interaction rate of the cosmic strings in some scenarios, resulting in an order of magnitude enhancement of the number/energy density of the cosmic string network when compared to the field theory case.
Hems to Hairdos: Cultural Discourse and Philadelphia Catholic High Schools in the 1920s, A Case Study

Ode to a Spring Uniform O believe me if all of the flagrant bright blue, Which to many an eye has brought hurt, Were to fade in the wash to some delicate hue, Both the blouse and the unplaited skirt. Thou wouldst then be more fit for the pupils to wear, Though thy advocates boost thee sky high, For this loud awful color is more than we'll bear If thy shade can be changed by a dye
Extragalactic Foregrounds of the Cosmic Microwave Background: Prospects for the MAP Mission

While the major contribution to the cosmic microwave background (CMB) anisotropies are the sought-after primordial fluctuations produced at the surface of last scattering, other effects produce secondary fluctuations at lower redshifts. Here we study the extragalactic foregrounds of the CMB in the context of the upcoming Microwave Anisotropy Probe (MAP) mission. We first survey the major extragalactic foregrounds and show that discrete sources, the Sunyaev-Zeldovich (SZ) effect, and gravitational lensing are the most dominant ones for MAP. We then show that MAP is expected to detect (>5 σ) about 46 discrete sources directly with 94 GHz fluxes above 2 Jy. The most prominent SZ features on the CMB sky are rich clusters of galaxies. In particular, we show that the Coma Cluster will be clearly detected and marginally resolved by MAP. We then consider a cosmological population of clusters, and show that MAP should detect (>5 σ) about 10 SZ clusters directly. The mean SZ fluxes of fainter clusters can be probed by cross-correlating MAP with cluster positions extracted from existing catalogs. For instance, a MAP-XBACs cross-correlation will be sensitive to clusters with S(94 GHz) 200 mJy, and will thus provide a test of their virialization state and a measurement of their gas fraction. Finally, we consider probing the hot gas on supercluster scales by cross-correlating the CMB with galaxy catalogs. Assuming that galaxies trace the gas, we show that a cross-correlation between the (MAP) and the Automatic Plate Measuring Facility (APM) catalog should yield a marginal detection, or at least a fourfold improvement on the COBE upper limits for the rms Compton y parameter.
The thermoelectric properties of quaternary chalcogenides

Abstract Four compounds of the general composition 12 2 36 4 have been studied to ascertain their thermoelectric properties. Measurements were performed on pressed and sintered samples. The compounds were identified by their Debye-Scherrer pattern and metallographic examination confirmed the presence of a single phase. Determinations were made of the thermoelectric power, the electrical conductivity. Hall coefficient, optical reflectivity and microhardness. The results of this investigation indicate that the bandgap in these semiconductors is less than 0.5 eV. The electronic properties are discussed in terms of alloy and ionized impurity scattering.
Synthesis of 2-Keto-anti-1,3-diols by Chemoselective Tandem Oxidation of 2-B(pin)-Substituted Allylic Alcohols†

The VO(acac)2-catalyzed oxidations proceed under neutral conditions with excellent diastereoselectivity to give the epoxides (II).
Complementary and Alternative Medicine for Posttraumatic Stress Disorder Symptoms A Systematic Review

Objectives.To (1) characterize complementary and alternative medicine studies for posttraumatic stress disorder symptoms, (2) evaluate the quality of these studies, and (3) systematically grade the scientific evidence for individual CAM modalities for posttraumatic stress disorder.Design.Systematic review. Eight data sources were searched. Selection criteria included any study design assessing posttraumatic stress disorder outcomes and any complementary and alternative medicine intervention. The body of evidence for each modality was assessed with the Natural Standard evidence-based, validated grading rationale.Results and Conclusions.Thirty-three studies (n = 1329) were reviewed. Scientific evidence of benefit for posttraumatic stress disorder was strong for repetitive transcranial magnetic stimulation and good for acupuncture, hypnotherapy, meditation, and visualization. Evidence was unclear or conflicting for biofeedback, relaxation, Emotional Freedom and Thought Field therapies, yoga, and natural prod...
Markets, governments, and HMO development in the 1990s.

This article examines the impact of population demographics, health market characteristics, and government purchasing and regulation on the development of the HMO industry in the 1990s. I focus on two facets of development-HMO market share and the number of HMOs in operation in metropolitan areas. My central findings are threefold: Population size is a critical determinant of development. Health market characteristics such as hospital expenditures and physician supply affect development, but often in ways that differ from previous periods (e.g., development is greater in areas with relatively large numbers of specialists). Both government purchasing and regulation affect development, but in ways that may be contradictory in motivation and outcome (e.g., state officials seek to contain costs through Medicaid and Medicare managed care and to enhance consumer protection and satisfaction through regulations such as coverage requirements). These results imply that in a period in which development is increasingly occurring in areas that may have unfavorable markets, policy makers (unlike in earlier eras) influence HMO supply and demand, through their roles both as purchasers and as regulators of managed care.
Equatorial superrotation on tidally locked exoplanets

The increasing richness of exoplanet observations has motivated a variety of three-dimensional (3D) atmospheric circulation models of these planets. Under strongly irradiated conditions, models of tidally locked, short-period planets (both hot Jupiters and terrestrial planets) tend to exhibit a circulation dominated by a fast eastward, or 'superrotating', jet stream at the equator. When the radiative and advection timescales are comparable, this phenomenon can cause the hottest regions to be displaced eastward from the substellar point by tens of degrees longitude. Such an offset has been subsequently observed on HD 189733b, supporting the possibility of equatorial jets on short-period exoplanets. Despite its relevance, however, the dynamical mechanisms responsible for generating the equatorial superrotation in such models have not been identified. Here, we show that the equatorial jet results from the interaction of the mean flow with standing Rossby waves induced by the day-night thermal forcing. The strong longitudinal variations in radiative heating-namely intense dayside heating and nightside cooling-trigger the formation of standing, planetary-scale equatorial Rossby and Kelvin waves. The Rossby waves develop phase tilts that pump eastward momentum from high latitudes to the equator, thereby inducing equatorial superrotation. We present an analytic theory demonstrating this mechanism and explore its properties inmore » a hierarchy of one-layer (shallow-water) calculations and fully 3D models. The wave-mean-flow interaction produces an equatorial jet whose latitudinal width is comparable to that of the Rossby waves, namely the equatorial Rossby deformation radius modified by radiative and frictional effects. For conditions typical of synchronously rotating hot Jupiters, this length is comparable to a planetary radius, explaining the broad scale of the equatorial jet obtained in most hot-Jupiter models. Our theory illuminates the dependence of the equatorial jet speed on forcing amplitude, strength of friction, and other parameters, as well as the conditions under which jets can form at all.« less
The reconstruction of analog signals from the sign of their noisy samples

The reconstruction of a continuous-time signal s(t) from the sign of its (deliberately) contaminated samples is considered. Sequential, generally nonlinear estimates of s(t) are established and their performance is studied; error bounds and convergence rates are derived. The signal s(t) need not be band-limited. The convergence rates obtained here are faster than those obtained previously for nonsequential estimates. The degradation in the reconstruction of the signal, due to transmission over a noisy channel, is also investigated, and bounds on the additional error are obtained.
Motivational and Emotional Aspects of the Self

Recent theory and research are reviewed regarding self-related motives (self-enhancement, self-verification, and self-expansion) and self-conscious emotions (guilt, shame, pride, social anxiety, and embarrassment), with an emphasis on how these motivational and emotional aspects of the self might be related. Specifically, these motives and emotions appear to function to protect people’s social well-being. The motives to self-enhance, self-verify, and self-expand are partly rooted in people’s concerns with social approval and acceptance, and self-conscious emotions arise in response to events that have real or imagined implications for others’ judgments of the individual. Thus, these motives and emotions do not operate to maintain certain states of the self, as some have suggested, but rather to facilitate people’s social interactions and relationships.