cssi/SciSciGPT-SciSciNet huggingface dataset:
Gamma-ray burst afterglow: Polarization and analytic light curves

Gamma-ray burst afterglow polarization is discussed. We find an observable, up to ~10%, polarization, if the magnetic field coherence length grows at about the speed of light after the field is generated at the shock front. Detection of a polarized afterglow would show that collisionless ultrarelativistic shocks can generate strong large-scale magnetic fields and confirm the synchrotron afterglow model. Nondetection, at the ~1% level, would imply that either the synchrotron emission model is incorrect or that strong magnetic fields, after they are generated in the shock, somehow manage to stay undissipated at "microscopic," skin depth, scales. Analytic light curves of synchrotron emission from an ultrarelativistic self-similar blast wave are obtained for an arbitrary electron distribution function, taking into account the effects of synchrotron cooling. The peak synchrotron flux and the flux at frequencies much smaller than the peak frequency are insensitive to the details of the electron distribution function; hence, their observational determination would provide strong constraints on blast-wave parameters.
Spatial gradients in particle reinforced polymers characterized by X-ray attenuation and laser confocal microscopy

The goal of this work is to develop techniques for measuring gradients in particle concentration within filled polymers, such as thermosetting polymer encapsulants. A high concentration of filler particles is added to such materials to tailor physical properties such as thermal expansion coefficient. Sedimentation and flow-induced migration of particles can produce concentration gradients that are most severe near boundaries. Therefore, techniques for measuring local particle concentration should be accurate near boundaries. Particle gradients in an alumina-filled epoxy resin are measured with a spatial resolution of 0.2 mm using an X-ray beam attenuation technique, but an artifact reduces accuracy near the specimen's edge. Local particle concentration near an edge can be measured more reliably using microscopy coupled with image analysis. This is illustrated by measuring concentration profiles of glass particles having 40 μm median diameter using images acquired with a confocal laser fluorescence microscope. The mean of the measured profiles of volume fraction agrees to better than 3% with the expected value and the shape of the profiles agrees qualitatively with simple theory for sedimentation of monodisperse particles. Evidence that the microscopic method can be extended to smaller particles is provided by local concentration measurements on an epoxy polymer containing particles having diameters of the order of 1 μm.
Double implementation of Lindahl allocations by a pure mechanism

This paper considers the issue of designing mechanisms whose Nash allocations and strong Nash allocations coincide with Lindahl allocations for public goods economies when coalition patterns, preferences, and endowments are unknown to the designer. It will be noted that the mechanism presented here is feasible and continuous, and the implementation result is obtained without defining an artificial preference profile on prices announced by individuals. In addition, unlike most existing Nash-implementing mechanisms which need to distinguish the case of two agents from that of three or more agents, this paper provides a unified mechanism which is irrespective of the number of agents.
Remarks on Countable Tightness

Abstract Countable tightness may be destroyed by countably closed forcing. We characterize the indestructibility of countable tightness under countably closed forcing by combinatorial statements similar to the ones Tall used to characterize indestructibility of the Lindelof property under countably closed forcing. We consider the behavior of countable tightness in generic extensions obtained by adding Cohen reals. We show that certain classes of well-studied topological spaces are indestructibly countably tight. Stronger versions of countable tightness, including selective versions of separability, are further explored.
Normal Investors, Then and Now

Investors were “normal” in 1945 when the first issue of the Financial Analysts Journal was published, and they remain normal today, 60 years later. But in between was a long period, starting in the late 1950s, when investors were described as “rational.” The portrait of investors as rational is the first foundation block of standard finance. Other foundation blocks are market efficiency, mean–variance portfolio theory, and the capital asset pricing model. This article provides descriptions of normal investors as they were portrayed in the FAJ and other finance journals before standard finance was introduced and as they have emerged recently in behavioral finance.
Delaying satisfiability for random 2SAT

Let (C1,C′(*)),(C2,C′(*)),…,(C m,C′(*)) be a sequence of ordered pairs of 2CNF clauses chosen uniformly at random (with replacement) from the set of all 4 clauses on n variables. Choosing exactly one clause from each pair defines a probability distribution over 2CNF formulas. The choice at each step must be made on-line, without backtracking, but may depend on the clauses chosen previously. We show that there exists an on-line choice algorithm in the above process which results whp in a satisfiable 2CNF formula as long as m/n ≤ (1000/999)1/4. This contrasts with the well-known fact that a random m -clause formula constructed without the choice of two clauses at each step is unsatisfiable whp whenever m/n > 1. Thus the choice algorithm is able to delay satisfiability of a random 2CNF formula beyond the classical satisfiability threshold. Choice processes of this kind in random structures are known as “Achlioptas processes.” This paper joins a series of previous results studying Achlioptas processes in different settings, such as delaying the appearance of a giant component or a Hamilton cycle in a random graph. In addition to the on-line setting above, we also consider an off-line version in which all m clause-pairs are presented in advance, and the algorithm chooses one clause from each pair with knowledge of all pairs. For the off-line setting, we show that the two-choice satisfiability threshold for k -SAT for any fixed k coincides with the standard satisfiability threshold for random 2k -SAT.© 2012 Wiley Periodicals, Inc. Random Struct. Alg., 2013
Restructuring Industries: The Carrot and the Stick

Restructuring brings market incentives into formerly monopolized network industries and raises a host of questions about whether the carrot of profit seeking can be disciplined by the stick of competition. In the telephone industry access pricing is an issue, and major problems are illustrated. In the electricity industry other problems are described and possible solutions are briefly sketched.
Product Form and Local Balance in Queueing Networks

A new property of queueing discipline, station balance, seems to explain why some disciplines yield product form solutions for queues and networks using nonexponential service disciplines and other disciplines do not. A queueing discipline satisfies station balance if rates at which customers receive service at each position of the queue are proportional to the probability that a customer arrives at that position. Station and local balance in queues and networks of queues are investigated. In addition to characterizing local balance and product form, the results of the paper generalize previous results on local balance to arbitrary differentiable service distribution functions.
Centers of Hodge groups of superelliptic Jacobians

We give lower bounds for dimensions of the centers of Hodge groups of superelliptic Jacobians. In the “generic case” this bound is precise. We also discuss dimensions of simple abelian subvarieties of superelliptic Jacobians.
Personal identity and the Phineas Gage effect

Phineas Gage’s story is typically offered as a paradigm example supporting the view that part of what matters for personal identity is a certain magnitude of similarity between earlier and later individuals. Yet, reconsidering a slight variant of Phineas Gage’s story indicates that it is not just magnitude of similarity, but also the direction of change that affects personal identity judgments; in some cases, changes for the worse are more seen as identity-severing than changes for the better of comparable magnitude. Ironically, thinking carefully about Phineas Gage’s story tells against the thesis it is typically taken to support
BAN THE BOX TO PROMOTE EX-OFFENDER EMPLOYMENT

It is close to a criminological truism that the lack of a legitimate job fosters criminality and, conversely, that holding a legitimate job diminishes criminal conduct. Consequently, many criminologists and social reformers have long advocated programs to expand employment opportunities for ex-offenders, particularly for those who have served prison time. Strategies for improving employability of ex-offenders include providing ex-offenders with basic education and job-specific training, assisting in identifying potential employment opportunities, interceding on the job seeker’s behalf with prospective employers, and eliminating de jure and de facto employment discrimination against ex-offenders. Many federal and state laws make ex-offenders, or at least certain categories of ex-offenders, ineligible to obtain employment licenses or to work in organizations serving children, the elderly, and other vulnerable populations (Love, 2006). In fact, such laws have proliferated during the past two decades on account of tough-on-crime politics and heightened post-9/11 security concerns. The reentry movement has cast a bright light on these collateral consequences of conviction and has urged a wholesale review and reform of them (American Bar Association, 2004; Travis, 2005). We agree with reentry proponents that de jure prohibitions on exoffender employment are far too overbroad and that many should be repealed. In this article, however, we focus on de facto discrimination to highlight a recent trend for cities to voluntarily stop asking for criminal background information from applicants seeking city employment and, in some instances, employment with vendors who contract with the city (National Employment Law Project (NELP), 2007). By recognizing that society has much to lose by excluding ex-offenders from legitimate employment opportunities, several cities such as Boston, San Francisco, and Minneapolis have agreed to “ban the box” on initial job applications that ask applicants about past criminal convictions. These cities have committed themselves not to discriminate against ex-offenders and not to consider an applicant’s prior criminal record unless it is clearly related to the requirements of a particular position. This welcome step, if successful, might persuade other public and private employers to stop discriminating against job applicants with a criminal record.
Nanoscale optofluidic sensor arrays for Dengue virus detection

In this paper we present our work towards the development of nanoscale optofluidic sensor arrays (NOSAs) for Dengue virus detection. Our approach is based on the use of optically resonant devices whose resonant wavelength is shifted due to a local change in refractive index caused by a positive binding event between a surface bound molecule and it solution phase target. A special two stage micro-/nanofluidics architecture is used to first functionalize the devices and then to deliver the targets. Experimental results measuring the bulk sensitivity of the device are shown to agree extremely well with theory. Preliminary data showing the successful detection of one of the four Dengue virus serotypes is also presented. The primary advantage of these devices over the state of the art is that they combine the extensive property sensitivity (mass limit of detection) of nanosensor devices with the parallelism of the microarray format.
Scissors congruence as $K$-theory

Scissors congruence groups have traditionally been expressed algebraically in terms of group homology. We give an alternate construction of these groups by producing them as the $0$-level in the algebraic $K$-theory of a Waldhausen category.
The composition and horizontal homogeneity of E region plasma layers

[1] A series of four NASA sounding rockets launched from Wallops Island, VA (37.84°N, 75.48°W), on 29–30 June 2003 between the hours of 23:19 and 3:07 EST observed an intermediate layer and a plasma density enhancement possibly associated with an internal gravity wave. Ion composition measurements were made by the third payload at 2:50 EST from 80- to 220-km altitude and included observations of three separate regions having high concentrations of metallic ions: a sporadic E layer at 105 km, an intermediate layer at 118 km, and the region above 160 km. The remaining payloads measured electron densities and made TMA chemical tracer releases at 23:19, 1:41, and 3:07 EST, respectively. This sequence of measurements shows that intermediate layers cannot be treated as flat layers over a scale of hundreds of kilometers and that internal gravity waves may lead to the formation of plasma layers in the nighttime lower F and upper E region ionosphere. The composition observations demonstrate that metallic ions may be a significant source of ionization in the nighttime E and F region ionosphere at midlatitudes, and that the relative ion composition within intermediate layers may fluctuate significantly over horizontal scales of hundreds of kilometers.
An ELLAM approximation for advective–dispersive transport with nonlinear sorption

We consider an Eulerian-Lagrangian localized adjoint method (ELLAM) applied to nonlinear model equations governing solute transport and sorption in porous media. Solute transport in the aqueous phase is modeled by standard advection and hydrodynamic dispersion processes, while sorption is modeled with a nonlinear local equilibrium model. We present our implementation of finite volume ELLAM (FVELLAM) and finite element (FE-ELLAM) discretizations to the reactive transport model and evaluate their performance for several test problems containing selfsharpening fronts.
Evolutionarily stable strategies in the repeated prisoner's dilemma

Abstract Recently evolutionary game theory has been used in analyzing the repeated prisoner's dilemma and the evolution of cooperation. In this paper Selten's three different ESS definitions in extensive form games are reviewed and applied to the repeated prisoner's dilemma with discounting. It is shown that neither normal form ESS nor direct ESS (in pure or mixed strategies) exists in this game when the players do not make a mistake at any decision node. But when players make an error at every decision node with a small but positive probability, a result analogous to the Folk Theorem can be proved for the limit ESS. Several remarks on the evolutionary interpretation of Axelrod's tournament results follow.
The Dynamic Compressive Response of an Open-Cell Foam Impregnated With a Non-Newtonian Fluid

The response of a reticulated, elastomeric foam filled with colloidal silica under dynamic compression is studied. Under compression beyond local strain rates on the order of 1s 1 , the non-Newtonian, colloidal silica-based fluid undergoes dramatic shear thickening and then proceeds to shear thinning. In this regime, the viscosity of the fluid is large enough that the contribution of the foam and the fluid-structure interaction to the stress response of the fluid-filled foam can be neglected. An analytically tractable lubrication model for the stress-strain response of a non-Newtonian fluid-filled, reticulated, elastomeric foam under dynamic compression between two parallel plates at varying instantaneous strain rates is developed. The resulting lubrication model is applicable when the dimension of the foam in the direction of fluid flow (radial) is much greater than that in the direction of loading (axial). The model is found to describe experimental data well for a range of radius to height ratios 1‐4 and instantaneous strain rates of the foam (1 s 1 to 410 2 s 1 ). The applicability of this model is discussed and the range of instantaneous strain rates of the foam over which it is valid is presented. Furthermore, the utility of this model is discussed with respect to the design and development of energy absorption and blast wave protection equipment. DOI: 10.1115/1.3130825
Ultrafast electron dynamics in silver nanoparticle arrays

We present the results of ultrafast optical experiments on silver quantum dot super-lattices. Dramatic changes in the electron dynamics occur as a function of interparticle spacing due to enhanced dipolar coupling and, most importantly, electron delocalization.
An Approach for Evaluation of Gas Turbine Deposition

An approach for estimating deposition in gas turbines is described. This approach extrapolates deposition data from lower cost experiments than turbine engine or cascade tests. The purpose is a method to screen candidate fuels and turbine protection methods so that only the most promising need be evaluated in turbine tests. The deposition approach is applied to estimate deposition maintenance intervals for a tested fuel, evaluate benefits of hot gas cleanup, and provide fuel screening criteria.Copyright © 1991 by ASME
Mutual Fund Advisory Contracts: An Empirical Investigation

We investigate marginal compensation rates in mutual fund advisory contracts and find the following. Equity and foreign fund advisors receive higher marginal compensation than debt and domestic fund advisors. Advisors of funds with greater turnover receive higher marginal compensation. Also, closed-end fund advisors receive higher marginal compensation than open-end fund advisors. Finally, we find that marginal compensation is lower for advisors of large funds and members of large fund families. We argue that these differences in marginal compensation ref lect differences in advisor marginal product, differences in the difficulty of monitoring performance, differences in control environments, and scale economies.
Canonical Wnt/β‐catenin signaling is required for maintenance but not activation of Pitx2 expression in neural crest during eye development

Pitx2 is a paired-like homeodomain gene that acts as a key regulator of eye development. Despite its significance, upstream regulation of Pitx2 expression during eye development remains incompletely understood. We use neural crest-specific ablation of Ctnnb1 to demonstrate that canonical Wnt signaling is not required for initial activation of Pitx2 in neural crest. However, canonical Wnt signaling is subsequently required to maintain Pitx2 expression in the neural crest. Eye development in Ctnnb1-null mice appears grossly normal early but significant phenotypes emerge following loss of Pitx2 expression. LEF-1 and β-catenin bind Pitx2 promoter sequences in ocular neural crest, indicating a likely direct effect of canonical Wnt signaling on Pitx2 expression. Combining our data with previous reports, we propose a model wherein a sequential code of retinoic acid followed by canonical Wnt signaling are required for activation and maintenance of Pitx2 expression, respectively. Other key transcription factors in the neural crest, including Foxc1, do not require intact canonical Wnt signaling. Developmental Dynamics 239:3215–3225, 2010. © 2010 Wiley-Liss, Inc.
Superparamagnetic nanoparticle-supported enzymatic resolution of racemic carboxylates

Candida rugosa lipase immobilized on maghemite nanoparticles demonstrated high stereoselectivity in kinetic resolution of racemic carboxylates and improved long-term stability over its parent free enzyme, allowing the supported enzyme to be repeatedly used for a series of chiral resolution reactions.
Wedge sampling for computing clustering coefficients and triangle counts on large graphs

Graphs are used to model interactions in a variety of contexts, and there is a growing need to quickly assess the structure of such graphs. Some of the most useful graph metrics are based on triangles, such as those measuring social cohesion. Algorithms to compute them can be extremely expensive, even for moderately sized graphs with only millions of edges. Previous work has considered node and edge sampling; in contrast, we consider wedge sampling, which provides faster and more accurate approximations than competing techniques. Additionally, wedge sampling enables estimating local clustering coefficients, degree-wise clustering coefficients, uniform triangle sampling, and directed triangle counts. Our methods come with provable and practical probabilistic error estimates for all computations. We provide extensive results that show our methods are both more accurate and faster than state-of-the-art alternatives.
A biomolecular implementation of logically reversible computation with minimal energy dissipation

Energy dissipation associated with logic operations imposes a fundamental physical limit on computation and is generated by the entropic cost of information erasure, which is a consequence of irreversible logic elements. We show how to encode information in DNA and use DNA amplification to implement a logically reversible gate that comprises a complete set of operators capable of universal computation. We also propose a method using this design to connect, or 'wire', these gates together in a biochemical fashion to create a logic network, allowing complex parallel computations to be executed. The architecture of the system permits highly parallel operations and has properties that resemble well known genetic regulatory systems.
An Investigation of the Dislocation Structure of the NI/AG Phase Boundary

The Ni/Ag interphase boundary structure in the parallel cube-on-cube orientation was studied for the boundary planes (001) and (011). Coarsely spaced dislocations were found in all annealed interfaces; the origin of these was apparently differential thermal expansion of the bicrystal film. A detailed search for intrinsic periodic structure consistent with the O-lattice construction was made using X-ray diffraction, electron diffraction and transmission electron microscopy . No evidence for this could be found; such a relaxation, if present, is very weak. It is unlikely that such a small relaxation could account for the relative energy minimum associated with the parallel cube-on-cube orientation found by previous investigators.
Multivariate Ensemble Sensitivity with Localization

AbstractEnsemble sensitivities have proven a useful alternative to adjoint sensitivities for large-scale dynamics, but their performance in multiscale flows has not been thoroughly examined. When computing sensitivities, the analysis covariance is usually approximated with the corresponding diagonal matrix, leading to a simple univariate regression problem rather than a more general multivariate regression problem. Sensitivity estimates are affected by sampling error arising from a finite ensemble and can lead to an overestimated response to an analysis perturbation. When forecasts depend on many details of an analysis, it is reasonable to expect that the diagonal approximation is too severe. Because spurious covariances are more likely when correlations are weak, computing the sensitivity with a multivariate regression that retains the full analysis covariance may increase the need for sampling error mitigation. The purpose of this work is to clarify the effects of the diagonal approximation, and investi...
ASN Presidential Address 2013: Innovation and Individualization—The Path Forward for Nephrology

Welcome to the 47th Annual Meeting of the American Society of Nephrology (ASN)—Kidney Week 2013. Thank you for helping to lead the fight against kidney disease in the United States and across the globe. As ASN President, I would like to thank you for the opportunity to lead this outstanding
Structure of unstable light nuclei

Abstract The structure of light nuclei out to the drip lines and beyond up to Z∼8 is interpreted in terms of the shell model. Special emphasis is given to the underlying supermultiplet symmetry of the p -shell nuclei which form cores for neutrons and protons added in sd -shell orbits. Detailed results are given on the wave functions, widths, and Coulomb energy shifts for a wide range of non-normal parity states in the p -shell.
Predictors of bleeding disorders in children with epistaxis: value of preoperative tests and clinical screening.

Abstract Objective To identify prevalence of previously undiagnosed bleeding disorders in children with severe epistaxis who failed medical therapy requiring intraoperative nasal cautery. Study design Retrospective chart review 10/15/2006–12/31/2010. Setting Single provider outpatient otolaryngology clinic. Subjects and methods Inclusion criteria: children ( Results Of 248 subjects referred for epistaxis, 47(19%) met inclusion criteria (mean age 9.2 ± 0.5 years; 61.7% male). 31.9% (15/47) had abnormal coagulation studies but on repeat testing only 2 patients had persistent coagulation abnormalities. 15 patients were referred to hematology, 5 were diagnosed with a bleeding disorder (3 – type 1 von Willebrand's disease, 1 – platelet aggregation disorder, 1 – mild factor VII deficiency). Out of the entire cohort 10.6% (5/47) had a bleeding diathesis. Clinical predictive factors for having a bleeding diathesis were explored and included previous emergency room visits for epistaxis (p = 0.04). A trend was found in those presenting with epistaxis at a younger age (p = 0.07). Conclusion Children with recurrent epistaxis despite medical therapy are at higher risk of having a bleeding disorder. In this highly selected group of patients 10.6% (5/47) were found to have a bleeding disorder. Screening coagulation studies (PT, PTT) only revealed 20% (1/5) of patients with a bleeding disorder. Only a subsequent comprehensive hematology evaluation revealed the diagnosis in the majority of patients.
Calpain- and talin-dependent control of microvascular pericyte contractility and cellular stiffness

Pericytes surround capillary endothelial cells and exert contractile forces modulating microvascular tone and endothelial growth. We previously described pericyte contractile phenotype to be Rho GTPase- and α-smooth muscle actin (αSMA)-dependent. However, mechanisms mediating adhesion-dependent shape changes and contractile force transduction remain largely equivocal. We now report that the neutral cysteine protease, calpain, modulates pericyte contractility and cellular stiffness via talin, an integrin-binding and F-actin associating protein. Digital imaging and quantitative analyses of living cells reveal significant perturbations in contractile force transduction detected via deformation of silicone substrata, as well as perturbations of mechanical stiffness in cellular contractile subdomains quantified via atomic force microscope (AFM)-enabled nanoindentation. Pericytes overexpressing GFP-tagged talin show significantly enhanced contractility (~two-fold), which is mitigated when either the calpain-cleavage resistant mutant talin L432G or vinculin are expressed. Moreover, the cell-penetrating, calpain-specific inhibitor termed CALPASTAT reverses talin-enhanced, but not Rho GTP-dependent, contractility. Interestingly, our analysis revealed that CALPASTAT, but not its inactive mutant, alters contractile cell-driven substrata deformations while increasing mechanical stiffness of subcellular contractile regions of these pericytes. Altogether, our results reveal that calpain-dependent cleavage of talin modulates cell contractile dynamics, which in pericytes may prove instrumental in controlling normal capillary function or microvascular pathophysiology.
A METHOD FOR GENERATING VOLUMETRIC FEATURES FROM SURFACE FEATURES

Form features may be represented both as faces and as volumes. Feature volumes are necessary in automated process planning for relating a feature to the extent of material to be removed from a part, and for capturing the global characteristics of a part, such as tool accessibility. In this paper, a method will be presented for generating a feature volume from a set of feature faces, based on the technique of face extension. The implementation is currently limited to polyhedral parts. Examples will be given to illustrate the algorithm.
Progress in the Next Linear Collider Design

An electron/positron linear collider with a center-of-mass energy between 0.5 and 1 TeV would be an important complement to the physics program of the LHC. The Next Linear Collider (NLC) is being designed by a US collaboration (FNAL, LBNL, LLNL, and SLAC) which is working closely with the Japanese collaboration that is designing the Japanese Linear Collider (JLC). The NLC main linacs are based on normal conducting 11 GHz rf. This paper will discuss the technical difficulties encountered as well as the many changes that have been made to the NLC design over the last year. These changes include improvements to the X-band rf system as well as modifications to the injector and the beam delivery system. They are based on new conceptual solutions as well as results from the R&D programs which have exceeded initial specifications. The net effect has been to reduce the length of the collider from about 32 km to 25 km and to reduce the number of klystrons and modulators by a factor of two. Together these lead to s...
Redefining Social Network Services: A Solution to Personal Information and Knowledge Management

Instead of aiming at the augmentation of human communication abilities as other social software does, social network services (SNS) provide better chances for people to enhance their abilities to handle interpersonal relationships, by deriving their theoretical foundation from social network theory. However, they are far from working perfectly as reflected by the defects in the networks - distrust, fragmentation, and duplication. This paper addresses such problems innovatively in the context of personal information and knowledge management (PIKM), which involves a series of activities in our daily life and work that can be well supported by restructured SNS. While our future efforts target an operable SNS system as the solution to PIKM, our research at current stage gives full consideration to the identified problems, and achieves an initial system model with four primary modules: Personal Profile, Collaboration Workspace, Knowledge Network of Practice, and Platform.
Hemodynamic Effects of Prostaglandin E2

Prostaglandin (PG)E 2 has been used in obstetrics for several years as a mid-trimester abortifacient. The known side effects of PGE 2 include an increase in heart rate, pyrexia in 40% of patients, and tachypnea, which are well known to obstetricians. Although the central and peripheral effects of PGE 2 have been studied in animals, the potentially significant hemodynamic changes detectable by monitoring with a pulmonary-artery catheter are minimally explored in humans. We report our observations in a patient with the diagnosis of preeclampsia monitored with a pulmonary-artery catheter during treatment with PGE 2
Estimation of energy consumption in speed-independent control circuits

We describe a technique to estimate the energy consumed by speed-independent asynchronous (clock-less) control circuits. Because speed-independent circuits are hazard-free under all possible combinations of gate delays, we prove that an accurate estimate of their energy consumption is independent of relative component gate delays and can be determined by simulating only a small number of input patterns proportional to the size of the circuit's Signal Transition Graph specification. Specifically, we calculate the average energy per external signal transition consumed by a circuit. This can be used to compare the energy consumption between two different circuit implementations of the same specification, to calculate average energy for a given high-level operation, and to provide average circuit power when combined with delay information.
Energy efficiency in multiaccess fading channels under QoS constraints

In this paper, transmission over multiaccess fading channels under QoS constraints is studied in the low power regime. QoS constraints are imposed as limitations on the buffer violation probability. The effective capacity, which characterizes the maximum constant arrival rates in the presence of such statistical QoS constraints, is employed as the performance metric. The minimum received bit energy levels and wideband slope regions are characterized for different transmission and reception strategies, namely time-division multiple-access (TDMA), superposition coding with fixed decoding order, and superposition coding with variable decoding order. It is shown that the minimum received bit energies achieved by these different strategies are the same and independent of the QoS constraints. When wideband slope regions are considered, the suboptimality of TDMA with respect to superposition schemes is shown. For the case of superposition coding, it is proven that varying the decoding order at the receiver with the fading realizations does not enlarge the wideband slope region.
Solving k-Nearest Neighbor Problem on Multiple Graphics Processors

A recommendation system is a software system to predict customers' unknown preferences from known preferences. In a recommendation system, customers' preferences are encoded into vectors, and finding the nearest vectors to each vector is an essential part. This vector-searching part of the problem is called a $k$-nearest neighbor problem. We give an effective algorithm to solve this problem on multiple graphics processor units (GPUs). Our algorithm consists of two parts: an $N$-body problem and a partial sort. For a algorithm of the $N$-body problem, we applied the idea of a known algorithm for the $N$-body problem in physics, although another trick is need to overcome the problem of small sized shared memory. For the partial sort, we give a novel GPU algorithm which is effective for small $k$. In our partial sort algorithm, a heap is accessed in parallel by threads with a low cost of synchronization. Both of these two parts of our algorithm utilize maximal power of coalesced memory access, so that a full bandwidth is achieved. By an experiment, we show that when the size of the problem is large, an implementation of the algorithm on two GPUs runs more than 330 times faster than a single core implementation on a latest CPU. We also show that our algorithm scales well with respect to the number of GPUs.
Law enforcement agency defibrillation (LEA-D): proceedings of the National Center for Early Defibrillation Police AED Issues Forum.

proceedings of the National Center for Early Defibrillation police AED issues forum , Vincent N. Mosesso, Jr. *, Mary M. Newman , Joseph P. Ornato , Paul M. Paris , The National Center for Early Defibrillation Police AED Issues Forum 1 a National Center for Early Defibrillation, Department of Emergency Medicine, University of Pittsburgh, 230 McKee Place, Pittsburgh, PA 15213, USA b Medical College of Virginia, Richmond, VA, USA
MAFIA: a maximal frequent itemset algorithm for transactional databases

We present a new algorithm for mining maximal frequent itemsets from a transactional database. Our algorithm is especially efficient when the itemsets in the database are very long. The search strategy of our algorithm integrates a depth-first traversal of the itemset lattice with effective pruning mechanisms. Our implementation of the search strategy combines a vertical bitmap representation of the database with an efficient relative bitmap compression schema. In a thorough experimental analysis of our algorithm on real data, we isolate the effect of the individual components of the algorithm. Our performance numbers show that our algorithm outperforms previous work by a factor of three to five.
Topics in Multiple-Loop Regulators and Current-Mode Programming

Some general considerations about multiple-loop feedback are discussed, and it is concluded that incorporation of a current-programmed power stage into a ``new'' power stage model is both justified and useful. A new circuit-oriented model of the current feedback path is derived which augments the well-known power stage canonical circuit model. The current loop gain, though wide-band, is always stable if the conventional stabilizing ramp is employed but has a relatively small low-frequency value. Consequently, the ``new'' power stage is more usefully modeled by a y-parameter model in which the current loop is not explicit. Expressions for the y parameters are given that are extensions of those previously derived. Another form of the model resembles the original canonical form for duty ratio programming, and shows that current programming effectively introduces lossless series damping that separates widely the two poles of the power stage LC filter. Therefore, although current programming tends to make the power stage output behave as a current source, the contol-to-output voltage transfer function exhibits, in addition to the familiar dominant pole, a second pole at the current loop gain crossover frequency, which may lie anywhere from one-sixth to two-thirds of the switching frequency.
Life is Unfair in Latin America, But Does it Matter for Growth?

Summary I analyze the effect of inequality on economic growth in Latin America, where inequality is measured as the area of family farms as a percentage of the total area of agricultural holdings. Using data from 18 Latin American countries during 1960–2004, I find that inequality has a nonlinear effect on economic growth. Overall, for the countries included in this analysis, the share of family farms has a positive significant effect on economic growth. These findings are robust to controlling for several factors, using a different indicator of inequality (land Gini), and addressing for endogeneity.
A Simulation-Based Welfare Loss Calculation for Labor Taxes with Piecewise-Linear Budgets

Graduated income tax rates and transfer programs create piecewise-linear budget constraints that consist of budget segments and kink points. With any change in these tax rules, each individual may switch between a kink point and a budget segment, between two budget segments, or between two kink points. With errors in the estimated labor supply equation, the new choice is uncertain, and so the welfare effects of a tax change are uncertain. We propose a simulation-based method to compute expected welfare effects that is easy to implement and that fully accounts for uncertainties about choices around kink points. Our method also provides information about expected changes in working hours. D 2003 Elsevier B.V. All rights reserved.
Managing from the boundary: The effective leadership of self-managing work teams

We used in-depth critical incident interviews with the external leaders of self-managing work teams and their team members, and interviews and surveys provided by managers, to understand how effective leader behaviors and strategies unfold over time. Content analyses of the data produced a process model showing that effective external leaders move back and forth across boundaries to build relationships, scout necessary information, persuade their teams and outside constituents to support one another, and empower their teams to achieve success.
Recovery of burner acoustic source structure from far-field sound spectra

A method is presented that permits the thermal-acoustic efficiency spectrum in a long turbulent burner to be recovered from the corresponding far-field sound spectrum. An acoustic source/propagation model is used based on the perturbation solution of the equations describing the unsteady one-dimensional flow of an inviscid ideal gas with a distributed heat source. The technique is applied to a long cylindrical hydrogen-flame burner operating over power levels of 4.5-22.3 kW. The results show that the thermal-acoustic efficiency at a given frequency, defined as the fraction of the total burner power converted to acoustic energy at that frequency, is rather insensitive to burner power, having a maximum value on the order of 10 to the -4th at 150 Hz and rolling off steeply with increasing frequency. Evidence is presented that acoustic agitation of the flame at low frequencies enhances the mixing of the unburned fuel and air with the hot products of combustion. The paper establishes the potential of the technique as a useful tool for characterizing the acoustic source structure in any burner, such as a gas turbine combustor, for which a reasonable acoustic propagation model can be postulated.
Beyond C60: the higher fullerenes

This account describes the isolation and separation of stable higher fullerenes. The spectral data which support the structural assignments for these carbon spheres are compared to the data for C[sub 60] and C[sub 70]. Finally, perspectives of future research on higher fullerenes beyond C[sub 60] are outlined.
Thick-Section Weldments in 21-6-9 and 316LN Stainless Steel for Fusion Energy Applications

The Burning Plasma Experiment (BPX), formerly known as the Compact Ignition Tokomak, will be a major advance in the design of a fusion reactor. The successful construction of fusion reactors will require extensive welding of thick-section stainless steel plates. Severe service conditions will be experienced by the structure. Operating temperatures will range from room temperature (300 K) to liquid nitrogen temperature (77 K), and perhaps even lower. The structure will be highly stressed, and subject to sudden impact loads if plasma disruptions occur. This demands a combination of high strength and high toughness from the weldments. Significant portions of the welding will be done in the field, so preweld and postweld heat treatments will be difficult. The thick sections to be welded will require a high deposition rate process, and will result in significant residual stresses in the materials. Inspection of these thick sections in complex geometries will be very difficult. All of these constraints make it essential that the welding procedures and alloys be well understood, and the mechanical properties of the welds and their heat-affected zones must be adequately characterized.
Gold‐Catalyzed Cyclization Leads to a Bridged Tetracyclic Indolenine that Represses β‐Lactam Resistance

A gold-catalyzed desilylative cyclization was developed for facile synthesis of bridged tetracyclic indolenines, a common motif in many natural indole alkaloids. An antimicrobial screen of the cyclization products identified one compound which selectively potentiates β-lactam antibiotics in methicillin-resistant S. aureus (MRSA), and re-sensitizes a variety of MRSA strains to β-lactams.
C-METHYLATION OF PHENOLS, TYROSINE DERIVATIVES, AND A TYROSINE CONTAINING PEPTIDE

Abstract A two step procedure is reported for the efficient C-methylation of phenolic compounds using a Stille reaction. This procedure requires no phenol protection and is tolerant to a wide variety of functional groups.
Closed-form Grammians and model reduction for flexible space structures

The author derives analytical expressions for the Grammians of a model given in modal coordinates for the dynamics of a flexible space structure (FSS). These expressions are then used as the basis for a new algorithm to compute a dominant reduced-order model for such a system in an efficient manner. The resulting reduced-order model is obtained directly rather than by truncating a balanced model of the entire system, thus giving rise to significant efficiency gains for the typical FSS case where the reduced-order model is of very much lower order than the original system. >
Mixing Time of Critical Ising Model on Trees is Polynomial in the Height

In the heat-bath Glauber dynamics for the Ising model on the lattice, physicists believe that the spectral gap of the continuous-time chain exhibits the following behavior. For some critical inverse-temperature β c , the inverse-gap is O(1) for β < β c , polynomial in the surface area for β = β c and exponential in it for β > β c . This has been proved for $${\mathbb{Z}^2}$$ except at criticality. So far, the only underlying geometry where the critical behavior has been confirmed is the complete graph. Recently, the dynamics for the Ising model on a regular tree, also known as the Bethe lattice, has been intensively studied. The facts that the inverse-gap is bounded for β < β c and exponential for β > β c were established, where β c is the critical spin-glass parameter, and the tree-height h plays the role of the surface area. In this work, we complete the picture for the inverse-gap of the Ising model on the b-ary tree, by showing that it is indeed polynomial in h at criticality. The degree of our polynomial bound does not depend on b, and furthermore, this result holds under any boundary condition. We also obtain analogous bounds for the mixing-time of the chain. In addition, we study the near critical behavior, and show that for β > β c , the inverse-gap and mixing-time are both exp[Θ((β − β c )h)].
A dynamic model system of household car ownership, trip generation, and modal split: model development and simulation experiment

A dynamic model of household car ownership and mode use is developed and applied to demand forecasting. The model system consists of three interrelated components: car ownership, mechanized trip generation, and modal split. The level of household car ownership is represented as a function of household attributes and mobility measures from the preceding observation time point using an ordered-response probit model. The trip generation model predicts the weekly number of trips made by household members using car or public transit, and the modal split model predicts the fraction of trips that are made by public transit. Household car ownership is a major determinant in the latter two model components. A simulation experiment is conducted using sample households from the Dutch National Mobility Panel data set and applying the model system to predict household car ownership and mode use under different scenarios on future household income, employment, and drivers’ license holding. Policy implications of the simulation results are discussed.
Diffusion of Particles in the Extracellular Matrix: The Effect of Repulsive Electrostatic Interactions

Diffusive transport of macromolecules and nanoparticles in charged fibrous media is of interest in many biological applications, including drug delivery and separation processes. Experimental findings have shown that diffusion can be significantly hindered by electrostatic interactions between the diffusing particle and charged components of the extracellular matrix. The implications, however, have not been analyzed rigorously. Here, we present a mathematical framework to study the effect of charge on the diffusive transport of macromolecules and nanoparticles in the extracellular matrix of biological tissues. The model takes into account steric, hydrodynamic, and electrostatic interactions. We show that when the fiber size is comparable to the Debye length, electrostatic forces between the fibers and the particles result in slowed diffusion. However, as the fiber diameter increases the repulsive forces become less important. Our results explain the experimental observations that neutral particles diffuse faster than charged particles. Taken together, we conclude that optimal particles for delivery to tumors should be initially cationic to target the tumor vessels and then change to neutral charge after exiting the blood vessels.
A Generalized Zames-Falb Multiplier

Lur'e systems represent feedback interconnections of a Linear Time-Invariant system with a nonlinear operator. The Zames-Falb criterion is a powerful tool to determine the stability of a Lur'e system when the nonlinear operator is defined by a monotonic, odd and single-valued function. The article provides a generalization of the Zames-Falb criterion for the analysis of stability of a Lur'e system for nonlinear static operators that are “approximately” monotonic and odd. This result extends the standard Zames-Falb criterion with an additional notion of “robustness”.