cssi/SciSciGPT-SciSciNet huggingface dataset:
Preventing DoS attacks in peer-to-peer media streaming systems

This paper presents a framework for preventing both selfishness and denial-of-service attacks in peer-to-peer media streaming systems. Our framework, called Oversight, achieves prevention of these undesirable activities by running a separate peer-to-peer download rate enforcement protocol along with the underlying peer-to-peer media streaming protocol. This separate Oversight protocol enforces download rate limitations on each participating peer. These limitations prevent selfish or malicious nodes from downloading an overwhelming amount of media stream data that could potentially exhaust the entire system. Since Oversight is based on a peer-to-peer architecture, it can accomplish this enforcement functionality in a scalable, efficient, and decentralized way that fits better with peer-to-peer media streaming systems compared to other solutions based on central server architectures. As peer-to-peer media streaming systems continue to grow in popularity, the threat of selfish and malicious peers participating in such large peer-to-peer networks will continue to grow as well. For example, since peer-to-peer media streaming systems allow users to send small request messages that result in the streaming of large media objects, these systems provide an opportunity for malicious users to exhaust resources in the system with little effort expended on their part. However, Oversight addresses these threats associated with selfish or malicious peers who cause such disruptions with excessive download requests. We evaluated our Oversight solution through simulations and our results show that applying Oversight to peer-to-peer media streaming systems can prevent both selfishness and denial-of-service attacks by effectively limiting the download rates of all nodes in the system.
Synthesis of 2-amino-5-hydroxy-4-pyrimidones and 5,6-biheteroaryls using p-nitrophenyl 3-bromo-2,2-diethoxypropionate (NPBDP)

Abstract The reaction of NPBDP with various guanidines affords, after formic acid hydrolysis, 2-amino-5-hydroxy-4-pyrimidones. Reaction of NPBDP with o-aminoheterocycles gives similar results. NPBDP is readily converted to the 3-amino-2-alkenenitrile, 10, a key building block for the synthesis of 5,6-biheteroaryls.
Temporal filtering for point target detection in staring IR imagery: II. Recursive variance filter

We describe a recursive temporal filter based on a running estimate of the temporal variance followed by removal of the baseline variance of each pixel. The algorithm is designed for detection/tracking of 'point' targets moving at sub- pixel/frame velocities, 0.02 to 0.50 p/f, in noise-dominated scenarios on staring IR camera data. The technique responds to targets of either polarity. A preprocessing technique, morphological in origin but implemented by median filters, further improves the S/N sensitivity of the algorithm while restricting the result to positive contrast targets. The computationally simple algorithm has been implemented in hardware and real-time operation is in evaluation. The performance is characterized by some specific examples as well as plots over our extensive database of real data. Detection down to S/N approximately 3 or less and sensitivity to the appropriate range of velocities is demonstrated.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The economics of envy

Abstract Equity theory in psychology, observed responses to reform in socialist countries, and studies in the field of organizational behaviour all suggests that envy can play an important role in economic behaviour. This paper incorporates envy into the standard economic choice framework. The model provides a natural extension of the theory of equity in psychology. It is used to analyze how agents' innovating, retaliating, sabotaging, and sharing behaviour are jointly determined by legal institutions and agents' propensities for envy. Implications for the economics of organization and the reform of socialist economies are discussed.
Open string theory in (1+1)-dimensions

Abstract We show that tree level open two dimensional string theory is exactly solvable; the solution exhibits some unusual features, and is qualitatively different from the closed case. The open string “tachyon” S -matrix describes free fermions, which can be interpreted as the quarks at the ends of the string. These “quarks” live naturally on a lattice in space-time. We also find an exact vacuum solution of the theory, corresponding to a charged black hole.
Tight Contact Structures on Lens Spaces

In this paper we develop a method for studying tight contact structures on lens spaces. We then derive uniqueness and non-existence statements for tight contact structures with certain (half) Euler classes on lens spaces.
Modular Pyridinyl Peptide Ligands in Asymmetric Catalysis: Enantioselective Synthesis of Quaternary Carbon Atoms Through Copper-Catalyzed Allylic Substitutions

Highest enantioselectivities so far with dialkylzinc reagents! Quaternary carbon centers are formed enantioselectively through a Cu-catalyzed allylic substitution reaction that is promoted by pyridinyl peptide-based ligands in the presence of dialkylzinc reagents. The modularity of this new class of chiral ligands is exploited for reactivity and selectivity optimization.
The interaction between a pulsed astrophysical jet and small-scale heterogeneous media

We have performed two-dimensional hydrodynamic simulations of a pulsed astrophysical jet propagating through a medium that is populated with circular inhomogeneities, or clumps, which are smaller than the jet width. The clumps are seen to affect the jet in several ways, such as impeding jet propagation and deflecting the jet off-axis. While there has been some debate as to the prevalence of these types of condensations in the ISM or in molecular clouds, the exploration of this region of parameter space nonetheless both shows the potential for these clumps to disrupt astrophysical jets and yields results which recover aspects of recent observations of Herbig-Haro objects. We find that the propagation of the jet and the vorticity induced in the clump/ambient medium correlate well with a dynamic filling function -->fd across all the simulations.
Strategic equilibria and decisive set structures for social choice mechanisms

Abstract The connections between strategy selecting functions for social choice mechanisms and the power structure of the associated collections of decisive sets are investigated. Equilibrium conditions are presented that give rise to filters (oligarchies), prefilters (collegial polities), and acyclic majorities. The results broaden the dictatorship theorems of Gibbard and Satterthwaite and resolve open questions about conditions that lead to more democratic power structures.
Synthetic Studies on Nogarol Anthracyclines. Enantioselective Total Synthesis of an Aminohydroxy Epoxybenzoxocin

A chiral synthesis of the aminohydroxy expoxybenzoxocin 6 is described. Enantioselective Friedel-Crafts coupling using a chiral titanium catalyst was employed to produce the optically active atrolactic ester 16a from the phenol 11 and l-menthyl pyruvate (12). The phenolic group in 16a was protected as the benzyl ether and the t-alcohol functionality as the MEM ether to give 20, which after sequential reduction/oxidation provided the aldehyde 22. Addition of the acetylide anion of propargyl aldehyde diethyl acetal (23) to aldehyde 22, followed by oxidation of the resultant diastereoisomeric carbinols, gave the acetylenic ketone 24. Lindlar reduction of 24 afforded the trans-enone 26. Reaction of 26 with thiophenylate anion furnished 27, which was then cyclized to the alpha-methyl pyranoside 29. Oxidation of 29 to the sulfoxide and subsequent thermolysis afforded the hexenulose 30. Sequential epoxidation of 30, reduction of the keto epoxide 31, and reaction of the resultant epoxycarbinol 32 with dimethylamine produced the aminohydroxy pyranose 33a. Debenzylation of 33a to the phenol 33b, followed by intramolecular cyclization, completed the fabrication of the optically active aminohydroxy epoxybenzoxocin 6. The 17-step sequence from the phenol 11 to 6 was achieved in 22% overall yield.
Institutional innovation, contingency and war: A review

For over forty years, Douglass North has sought in his work to determine those conditions that favor economic growth. In his most recent writings he has emphasized the institutional innovations of the state and how these are often preceded, or accompanied, by transformations in beliefs and constitutional structures. This review of North's work also discusses the efforts of a younger generation of scholars in economic and political history to apply the tools of public choice theory in constructing “institutional narratives”. Such narratives often focus on the nature of constitutional quandaries that polities have faced in the past. The conclusion suggests that the study of such quandaries can lead to a better understanding of how and why states fight wars. Indeed, it might be possible to use the insights so gained to design international institutions to foster economic growth and preserve peace.
Cationic bis(oxazoline)Cu(II) Lewis acid catalysts. Enantioselective furan Diels-Alder reaction in the synthesis of ent-shikimic acid

Abstract The highly enantioselective Diels-Alder reaction between acryloyl oxazolidinone and furan, catalyzed by cationic bis(4-tert-butyloxazoline)Cu(II) complex 1, is presented. Though the reaction equilibrates rapidly at −20 °C, reaction at −78 °C permits isolation of the kinetic product mixture. The synthetic utility of the reaction is demonstrated by the conversion of the cycloadduct to ent-shikimic acid.
Financial Determinants of Domestic Investment in Sub-Saharan Africa: Evidence from Panel Data

Abstract This study investigates the effects of financial development on domestic investment in a sample of 30 sub-Saharan African countries. It is based on a dynamic serial-correlation investment model including various indicators of financial development, controlling for country-specific fixed effects and nonfinancial factors of investment. The results indicate a positive relationship between domestic investment (total investment and private investment) and various indicators of financial development. Higher financial development leads to higher future levels of investment, implying a potent long-run effect of financial development on domestic investment. The findings imply that financial development can stimulate economic growth through capital accumulation.
M theory and singularities of exceptional holonomy manifolds

M theory compactifications on G_2 holonomy manifolds, whilst supersymmetric, require singularities in order to obtain non-Abelian gauge groups, chiral fermions and other properties necessary for a realistic model of particle physics. We review recent progress in understanding the physics of such singularities. Our main aim is to describe the techniques which have been used to develop our understanding of M theory physics near these singularities. In parallel, we also describe similar sorts of singularities in Spin(7) holonomy manifolds which correspond to the properties of three dimensional field theories. As an application, we review how various aspects of strongly coupled gauge theories, such as confinement, mass gap and non-perturbative phase transitions may be given a simple explanation in M theory.
A Model for the Stray-Light Contamination of the UVCS Instrument on SOHO

We present a detailed model of stray-light suppression in the spectrometer channels of the Ultraviolet Coronagraph Spectrometer (UVCS) on the SOHO spacecraft. The control of diffracted and scattered stray light from the bright solar disk is one of the most important tasks of a coronagraph. We compute the fractions of light that diffract past the UVCS external occulter and non-specularly pass into the spectrometer slit. The diffracted component of the stray light depends on the finite aperture of the primary mirror and on its figure. The amount of non-specular scattering depends mainly on the micro-roughness of the mirror. For reasonable choices of these quantities, the modeled stray-light fraction agrees well with measurements of stray light made both in the laboratory and during the UVCS mission. The models were constructed for the bright H i Lyα emission line, but they are applicable to other spectral lines as well.
Chemistry and Biology of Diazonamide A: First Total Synthesis and Confirmation of the True Structure

With the addition of a tenth ring, the exchange of an oxygen atom for a nitrogen in the heart of the molecule, and a different terminal residue, the revised architecture for diazonamide A (1) provided an even more challenging molecular puzzle for chemical synthesis than its predecessor. In this article, we detail the first successful total synthesis of diazonamide A, an endeavor which not only verified its proper connectivities and established the stereochemistry of its previously unassignable C-37 chiral center, but which also was attended by the development of several new synthetic strategies and tactics.
A new procedure for dynamic adaption of three-dimensional unstructured grids

A new procedure is presented for the simultaneous coarsening and refinement of three-dimensional unstructured tetrahedral meshes. This algorithm allows for localized grid adaption that is used to capture aerodynamic flow features such as vortices and shock waves in helicopter flowfield simulations. The mesh-adaption algorithm is implemented in the C programming language and uses a data structure consisting of a series of dynamically-allocated linked lists. These lists allow the mesh connectivity to be rapidly reconstructed when individual mesh points are added and/or deleted. The algorithm allows the mesh to change in an anisotropic manner in order to efficiently resolve directional flow features. The procedure has been successfully implemented on a single processor of a Cray Y-MP computer. Two sample cases are presented involving three-dimensional transonic flow. Computed results show good agreement with conventional structured-grid solutions for the Euler equations.
KATZNELSON-TZAFRIRI TYPE THEOREMS FOR INDIVIDUAL SOLUTIONS OF EVOLUTION EQUATIONS

In this paper we present an extension of the Katznelson-Tzafriri Theorem to the asymptotic behavior of individual solutions of evolution equations u'(t) = Au(t) + f(t). The obtained results do not require the uniform continuity of solutions as well as the well-posedness of the equations. The method of study is based on a recently developed approach to the spectral theory of functions that is direct and free of C 0 -semigroups.
Theory of x-ray absorption by laser-dressed atoms

An ab initio theory is devised for the x-ray photoabsorption cross section of atoms in the field of a moderately intense optical laser (800 nm, 10{sup 13} W/cm{sup 2}). The laser dresses the core-excited atomic states, which introduces a dependence of the cross section on the angle between the polarization vectors of the two linearly polarized radiation sources. We use the Hartree-Fock-Slater approximation to describe the atomic many-particle problem in conjunction with a nonrelativistic quantum-electrodynamic approach to treat the photon-electron interaction. The continuum wave functions of ejected electrons are treated with a complex absorbing potential that is derived from smooth exterior complex scaling. The solution to the two-color (x-ray plus laser) problem is discussed in terms of a direct diagonalization of the complex symmetric matrix representation of the Hamiltonian. Alternative treatments with time-independent and time-dependent non-Hermitian perturbation theories are presented that exploit the weak interaction strength between x rays and atoms. We apply the theory to study the photoabsorption cross section of krypton atoms near the K edge. A pronounced modification of the cross section is found in the presence of the optical laser.
Development of scalable space-time averaged regression rate expressions for hybrid rockets

DOI: 10.2514/1.19226 The fuel regression rate expressions reported in the hybrid literature often depend explicitly on the physical dimensions of the system such as the fuel port diameter. Typically, when these dimensional formulas are applied to systems with significantly different scales, they produce grossly inaccurate results. This paper addresses the development of scalable space–time averaged regression rate formulas for hybrid rockets. The derivation process hingesonthe assumption thatthe local instantaneous regression rateisa function of the local mass fluxandthe axial port distance in the power law format as predicted by the classical theory developed by Marxman. In this study, we have developed physics-based nondimensional formulas for the space–time averaged regression rate and used these expressions to develop a scalable regression rate law for a selected propellant combination, paraffin-based SP-1a/ GOX,fromlimitedmotordata.Initially,spaceandtimeaveragingaretreatedseparately,whichwerelatercombined to develop a technique that allows for the coupling between the spatial and time variations to predict the port diameter and mass flow rate profiles as functions of time. Finally, a comprehensive technique to estimate the systematic and random errors on the regression rate and mass flux data is also outlined.
Quantifying Uncertainty in Statistical Distribution of Small Sample Data Using Bayesian Inference of Unbounded Johnson Distribution

Probabilistic analysis of physical systems requires information on the distributions of random variables. Distributions are typically obtained from testing or field data. In engineering design where tests are expensive, the sample size of such data is small O(10). Identifying correct distributions with small number of samples is difficult. Furthermore, parameters of assumed distributions obtained from small sample data themselves contain some uncertainty. In this study a Johnson SU family distribution function is used to identify shape, location and scale parameters of distribution that can best fit small sample data. A Bayesian inference procedure is used to determine distributions of the parameters. We show that the procedure correctly bounds the tail regions of the distributions and is less conservative than bounds obtained using bootstrap methods.
Gender of Siblings and Choice of College Major

In this study, we analyze whether the gender of a student’s siblings affects the choice of college major. A family with same-gender siblings may encourage academic choices that are less gender stereotyped. We use a unique dataset covering 30,000 Italian students who graduated from high school between 1985 and 2005 that allows us to identify siblings. We follow their academic careers from high school to college graduation. We find that mixed-gender siblings tend to choose college majors following a stronger genderstereotypical specialization: males have higher probability of choosing ‘male dominated’ majors such as Engineering and Economics. Same-gender siblings, on the other hand, have higher probability of making non-gender-stereotypical choices. This college major choice is not driven by the choice of high school academic curriculum, which appears to be mainly function of geographical proximity to schools. (JEL codes: I21, J12, J16, Z18).
Heavy baryons in a quark model

A quark model is applied to the spectrum of baryons containing heavy quarks. The model gives masses for the known heavy baryons that are in agreement with experiment, but for the doubly-charmed baryon Ξcc, the model prediction is too heavy. Mixing between the ΞQ and Ξ′Q states is examined and is found to be small for the lowest lying states. In contrast with this, mixing between the Ξbc and Ξ′bc states is found to be large, and the implication of this mixing for properties of these states is briefly discussed. We also examine heavy-quark spin-symmetry multiplets, and find that many states in the model can be placed in such multiplets. We compare our predictions with those of a number of other authors.
Wasserstein Continuity of Entropy and Outer Bounds for Interference Channels

It is shown that under suitable regularity conditions, differential entropy is $O(\sqrt {n})$ -Lipschitz as a function of probability distributions on $ \mathbb {R}^{n}$ with respect to the quadratic Wasserstein distance. Under similar conditions, (discrete) Shannon entropy is shown to be $O(n)$ -Lipschitz in distributions over the product space with respect to Ornstein’s $\bar d$ -distance (Wasserstein distance corresponding to the Hamming distance). These results together with Talagrand’s and Marton’s transportation-information inequalities allow one to replace the unknown multi-user interference with its independent identically distributed approximations. As an application, a new outer bound for the two-user Gaussian interference channel is proved, which, in particular, settles the missing corner point problem of Costa (1985).
Update on the Argonne positron accumulator ring

The injector for the Advanced Photon Source incorporates a 450-MeV positron accumulator ring (PAR) to decrease the filling time with the 2-Hz synchrotron. In addition to accumulating positrons from the linac, the PAR damps the beam and reduces the bunch length. The PAR lattice has been redesigned to use zero-gradient dipoles, while retaining essentially the same damping partition. Extensive simulations have been performed to set tolerances that will give high capture efficiency, in spite of the large momentum spread of the incoming positron beam. >
If only I had the time! The impact of time salience on consumers' evaluations of product offers

We explore consumers' consideration of their time budgets when evaluating product offers in a context in which we expect those budgets are most easily ignored—product giveaways. Across three studies, we manipulate the salience of time for participants considering free seminars (Study 1a) and free vacations (Studies 1b and 2) to be received in the near or distant future. Beginning with Study 1, we demonstrate that when time is made salient to them, consumers consider slack in their time budgets when evaluating near-future but not distant-future product giveaways. Otherwise, consumers appear to largely ignore time budget slack when evaluating free offers. In Study 2, we replicate these basic effects while providing evidence that consumers' consider slack in their time budgets at the point they commit to a giveaway rather than at the point when they will receive the product. We discuss these findings in terms of both their theoretical and marketing implications. Copyright © 2013 John Wiley & Sons, Ltd.
An imino Nazarov cyclization

Abstract α-Aminocyclopentenones are available in a single operation from α,β-unsaturated nitriles and (methoxy)methoxyallenes. The cyclization is equivalent to an imino Nazarov reaction.
The effects of hypertext glosses on L2 vocabulary acquisition: a meta-analysis

This study examines (1) the effects of hypertext gloss use on L2 vocabulary acquisition in computerized reading contexts; (2) which specific combination of either text-only (single) or text + visual (multiple) hypertext glosses is more effective on L2 vocabulary acquisition; and (3) potential moderators to systematically account for between study variation. In addition, it aims to synthesize characteristics of studies, technology use, and research methods from empirical research studies for a comprehensible and insightful review of the effect of hypertext glosses on L2 vocabulary acquisition. Meta-analysis was conducted to synthesize overall findings of empirical studies by calculating a standardized mean difference effect size. On the basis of 35 weighted mean effect sizes, the magnitude of text + visual (multiple) hypertext gloss combination was moderately effective on L2 vocabulary acquisition when L2 learners were given two conditions: text-only and text + visual hypertext glosses. The results reveale...
A simple model of inequality, occupational choice, and development

Abstract We analyze a simple and tractable model of occupational choice in the presence of credit market imperfections. We examine the effect of parameters governing technology and transaction costs, and history, in terms of the initial wealth distribution, in determining the long-term wealth distribution and the level of per capita income of an economy.
Algorithms for closed under rational behavior (CURB) sets

We provide a series of algorithms demonstrating that solutions according to the fundamental game-theoretic solution concept of closed under rational behavior (CURB) sets in two-player, normal-form games can be computed in polynomial time (we also discuss extensions to n-player games). First, we describe an algorithm that identifies all of a player's best responses conditioned on the belief that the other player will play from within a given subset of its strategy space. This algorithm serves as a subroutine in a series of polynomial-time algorithms for finding all minimal CURB sets, one minimal CURB set, and the smallest minimal CURB set in a game. We then show that the complexity of finding a Nash equilibrium can be exponential only in the size of a game's smallest CURB set. Related to this, we show that the smallest CURB set can be an arbitrarily small portion of the game, but it can also be arbitrarily larger than the supports of its only enclosed Nash equilibrium. We test our algorithms empirically and find that most commonly studied academic games tend to have either very large or very small minimal CURB sets.
Synthesis of manufacturable analog circuits

We describe a synthesis system that takes operating range constraints and inter- and intra-circuit parametric manufacturing variations into account while designing a sized and biased analog circuit. Previous approaches to CAD for analog circuit synthesis have concentrated on nominal analog circuit design, and subsequent optimization of these circuits for statistical fluctuations and operating point ranges. Our approach simultaneously synthesizes and optimizes for operating and manufacturing variations by mapping the circuit design problem into an Infinite Programming problem and solving it using an annealing within annealing formulation. We present circuits designed by this integrated synthesis system, and show that they indeed meet their operating range and parametric manufacturing constraints.
Si-based sensor for virus detection

This paper describes the development of a sensor for the detection of viruses. The detection scheme uses sense and dummy capacitors and a sense amplifier circuit to compare capacitance values. The presence of sufficient biological material within the sense capacitor alters the sense amplifier output. This promising approach has the potential to more rapidly test for the presence of virus using an IC platform.
A simulation based performance comparison study of stability-based routing, power-aware routing and load-balancing on-demand routing protocols for mobile ad hoc networks

The high-level contribution of this paper is a simulation-based detailed performance comparison of three different classes of on-demand routing protocols for mobile ad hoc networks: stability-based routing, power-aware routing and load-balanced routing. We choose the Flow-Oriented Routing protocol (FORP), Min-Max Battery Cost Routing (MMBCR) and the traffic interference based Load Balancing Routing (LBR) protocol as representatives of the stability-based routing, power-aware routing and load-balancing routing protocols respectively. FORP incurs the least number of route transitions; while LBR incurs the smallest hop count and lowest end-to-end delay per data packet. Energy consumed per data packet is the least for LBR, closely followed by MMBCR. FORP incurs the maximum energy consumed per data packet, both in the absence and presence of power control. Nevertheless, in the presence of power control, the end-to-end delay per data packet and energy consumed per data packet incurred by FORP are significantly reduced compared to the scenario without power control. MMBCR is the most fair in terms of node usage and incurs the largest time for first node failure. FORP tends to repeatedly use nodes lying on the stable path and hence is the most unfair of the three routing protocols. FORP also incurs the smallest value for the time of first node failure.
Reassessing the Cost of the Death Penalty Using Quasi-Experimental Methods: Evidence from Maryland

Extant research on the cost of the death penalty consistently finds that pursuit of a death sentence adds costs to case processing. However, these studies have important limitations in either the sampling frame or in their failure to include adequate statistical controls. This research draws upon a rich dataset of capital-eligible cases in Maryland to estimate the additional cost of filing a death notice. Multivariate models are used to control for selection into capital case processing and for competing explanations of cost. We find that filing a death notice is associated with an additional one million dollars in costs.
Enantioselective total synthesis of the antitumor macrolide rhizoxin D.

The convergent, highly enantioselective synthesis of rhizoxin D, a natural product possessing potent antitumor and antifungal bioactivity, is described. The C(1)−C(9) fragment of the molecule was synthesized utilizing a threefold pseudosymmetric intermediate ultimately derived from γ-butyrolactone. The central core of rhizoxin D was prepared via a chiral resolution/asymmetric aldol protocol. Several methods for the generation of the polyene fragment were explored, and the side-chain was ultimately prepared from serine in six steps. The unification of the left and right wings of the molecule was achieved using a one-step olefination protocol, and the macrocyclization was carried out using a Horner−Emmons olefination at the C(2)−C(3) olefin.
Optimal Monetary Stabilization Policy

Abstract This chapter reviews the theory of optimal monetary stabilization policy in New Keynesian models, with particular emphasis on developments since the treatment of this topic in Woodford (2003). The primary emphasis of the chapter is on methods of analysis that are useful in this area, rather than on final conclusions about the ideal conduct of policy (that are obviously model-dependent, and hence dependent on the stand that one might take on many issues that remain controversial), and on general themes that have been found to be important under a range of possible model specifications. 1 With regard to methodology, some of the central themes of this review will be the application of the method of Ramsey policy analysis to the problem of the optimal conduct of monetary policy, and the connection that can be established between utility maximization and linear-quadratic policy problems of the sort often considered in the central banking literature. With regard to the structure of a desirable decision framework for monetary policy deliberations, some of the central themes will be the importance of commitment for a superior stabilization outcome, and more generally, the importance of advance signals about the future conduct of policy, the advantages of history-dependent policies over purely forward-looking approaches, and the usefulness of a target criterion as a way of characterizing a central bank's policy commitment.
Dynamics and control of high duty counter-current heat exchangers

In this paper, we analyze a class of high duty counter-current heat exchangers. A high duty counter-current heat exchanger is modeled by two first order stiff PDEs, which show a potential of multi-time scale dynamics. Using singular perturbations, a non-stiff reduced model capturing the slow time scale dynamics is derived. Input/output linearizing controllers are derived based on both the full model and the reduced model, and the advantages of using the controller based on the reduced model are documented via simulations.
Fragment class analysis for testing of polymorphism in Java software

Testing of polymorphism in object-oriented software may require coverage of all possible bindings of receiver classes and target methods at call sites. Tools that measure this coverage need to use class analysis to compute the coverage requirements. However, traditional whole-program class analysis cannot be used when testing incomplete programs. To solve this problem, we present a general approach for adapting whole-program class analyses to operate on program fragments. Furthermore, since analysis precision is critical for coverage tools, we provide precision measurements for several analyses by determining which of the computed coverage requirements are actually feasible for a set of subject components. Our work enables the use of whole-program class analyses for testing of polymorphism in partial programs, and identifies analyses that potentially are good candidates for use in coverage tools.
Mixing fraction of inner solar system material in comet 81P/Wild2

The presence of crystalline silicates in the comae of comets, inferred through infrared observations, has been a long-standing puzzle. Crystalline silicates are unexpected if comets are composed of pristine interstellar material, since interstellar silicates are almost entirely amorphous. Heating to >1100 K can anneal silicates to crystallinity, but no protoplanetary heating sources have been identified that were sufficiently strong to heat materials in the outer nebula to such high temperatures. This conundrum led to the suggestion that large-scale mixing was important in the protoplanetary disk. Reports of refractory calcium-aluminum-rich inclusion-like objects and large concentrations of noble gases in Stardust samples underscore the need for such mixing. However, the evidence from the Stardust samples until now has been largely anecdotal, and it has not been possible to place quantitative constraints on the mixing fraction. Here we report synchrotron-based X-ray microprobe measurements of the relative concentrations of the chemical state of iron in material from a known comet, the Jupiter-family comet 81P/Wild2. We find that the comet is rich in iron sulfides. The elemental S/Fe ratio based on the sulfide concentration, S/Fe > 0.31(2σ), is higher than in most chondritic meteorites. We also found that Fe-bearing silicates are at least 50% crystalline. Based on these measurements, we estimate the fraction ψ of inner nebular material in 81P/Wild2. With the lower bound on the crystalline Fe-bearing silicate fraction, we find that ψ > 0.5. If the observed S depletion in the inner solar system predated or was contemporaneous with large-scale mixing, our lower bound on the S/Fe ratio gives an upper bound on ψ of ~0.65. This measurement may be used to test mixing models of the early solar system.
An efficient A* stack decoder algorithm for continuous speech recognition with a stochastic language model

The stack decoder is an attractive algorithm for controlling the acoustic and language model matching in a continuous speech recognizer. The author previously described a near-optimal admissible Viterbi A* search algorithm for use with non-crossword acoustic models and no-grammar language models (1991). This algorithm is extended to include unigram language models, and a modified version of the algorithm which includes the full (forward) decoder, cross-word acoustic models and longer-span language models is described. The resultant algorithm is not admissible, but has been demonstrated to have a low probability of search error and to be very efficient. >
The Curse of the Smartphone: Electronic Multitasking in Negotiations

In this study, we have explored the use of mobile phones during negotiations. Specifically, we examined the effects that multitasking — reading messages on a mobile phone while negotiating face to face — had on the outcome achieved in a negotiation, as well as on perceptions of professionalism, trustworthiness, and satisfaction. Using an experimental design in a face-to-face dyadic negotiation, we found that multitasking negotiators achieved lower payoffs and were perceived as less professional and less trustworthy by their partners.
The lasting impact of childhood health and circumstance

We quantify the lasting effects of childhood health and economic circumstances on adult health, employment and socioeconomic status, using data from a birth cohort that has been followed from birth into middle age. Controlling for parental income, education and social class, children who experience poor health have significantly lower educational attainment, poorer health, and lower social status as adults. Childhood health and circumstance appear to operate both through their impact on initial adult health and economic status, and through a continuing direct effect of prenatal and childhood health in middle age. Overall, our findings suggest more attention be paid to health as a potential mechanism through which intergenerational transmission of economic status takes place: cohort members born into poorer families experienced poorer childhood health, lower investments in human capital and poorer health in early adulthood, all of which are associated with lower earnings in middle age-the years in which they themselves become parents.
The Information Content of the Deferred Tax Valuation Allowance

An event study demonstrates that disclosures of changes in deferred tax valuation allowances (VA) provide information beyond contemporaneous earnings reports. Prior research shows that, in setting VA, managers consider the extent that taxable income is available from various sources for the realization of deferred tax assets (DTA). Our evidence supports a characterization where investors use VA disclosures to infer management's expectations about DTA, its realizability, and future taxable income available for realization. These findings are more generally relevant for assessing the consequences of reporting standards that require or permit management judgment, especially about future outcomes. In particular, they support the view that discretion can be a vehicle for management to communicate expectations to the benefit of investors.
Chisholm's Paradox and Conditional Oughts

Since it was presented in 1963, Chisholm’s paradox has attracted constant attention in the deontic logic literature, but without the emergence of any definitive solution. We claim this is due to its having no single solution. The paradox actually presents many challenges to the formalization of deontic statements, including (1) context sensitivity of unconditional oughts, (2) formalizing conditional oughts, and (3) distinguishing generic from nongeneric oughts. Using the practical interpretation of ‘ought’ as a guideline, we propose a linguistically motivated logical solution to each of these problems, and explain the relation of the solution to the problem of contrary-to-duty obligations.
Source Inversion for Contaminant Plume Dispersion in Urban Environments Using Building-Resolving Simulations

Abstract The ability to determine the source of a contaminant plume in urban environments is crucial for emergency-response applications. Locating the source and determining its strength based on downwind concentration measurements, however, are complicated by the presence of buildings that can divert flow in unexpected directions. High-resolution flow simulations are now possible for predicting plume evolution in complex urban geometries, where contaminant dispersion is affected by the flow around individual buildings. Using Bayesian inference via stochastic sampling algorithms with a high-resolution computational fluid dynamics model, an atmospheric release event can be reconstructed to determine the plume source and release rate based on point measurements of concentration. Event-reconstruction algorithms are applied first for flow around a prototype isolated building (a cube) and then using observations and flow conditions from Oklahoma City, Oklahoma, during the Joint Urban 2003 field campaign. Stoch...
Multidimensional Separations-Based Shotgun Proteomics

The proteome refers to the collection of proteins in a given biological organism or system under a particular set of environmental conditions. The study of proteins, referred to as proteomics, is performed to identify the components of a particular proteome and analyze global changes in protein expression in response to different stimuli. This leads to an understanding of physiological and pathological states of an organism through a comprehensive analysis of biological processes. From a protein complex to whole cell, proteome analysis deals with highly complex mixtures, requiring more than one analytical dimension to achieve the high resolving power necessary for reliable analysis. In 1975, O’Farrell and Klose described two-dimensional polyacrylamide gel electrophoresis (2D-PAGE)1,2 that could resolve complex protein mixtures into thousands of spots. Years later, upon the development of matrix-assisted laser desorption ionization (MALDI)3 and electrospray ionization (ESI),4,5 combined with database searching,6-9 the field of proteomics began to grow dramatically. Researchers were able to characterize complex mixtures of proteins and gain novel biological insights. Despite the longstanding success of 2D-PAGE coupled with mass spectrometry, several fundamental issues with the technology, including the challenges of identifying low-abundance proteins,10-12 membrane proteins,13 and proteins with extremes in isoelectric point (pI) and molecular weight (MW),14,15 drove researchers to develop alternative approaches for the separation of complex mixtures. This led to the emergence of shotgun proteomics based on the coupling of high-performance liquid chromatography (HPLC) and mass spectrometry (MS). Similar to the shotgun genomic sequencing approach in which DNA is broken into smaller pieces prior to sequencing and reassembled in silico, proteins are first digested into peptides and then analyzed by multidimensional chromatography coupled to tandem mass spectrometry (MS/MS). Thousands of tandem mass spectra are then compared to theoretical tandem mass spectra using database searching algorithms for the identification of proteins in the sample (Figure 1b). The inability of one-dimensional (1D) separation techniques to resolve complex biological samples for shotgun proteomics has required the development of multidimensional separation methods. A multidimensional separation includes two or more independent separation techniques (i.e., ion exchange, size exclusion, reversed phase, and affinity) coupled together for the analysis of a single sample. * Address correspondence to this author at the Stowers Institute for Medical Research, 1000 E. 50th St., Kansas City, MO 64110 [telephone (816) 9264457; fax (816) 926-4694; e-mail mpw@stowers-institute.org]. † These authors contributed equally to this work. 3654 Chem. Rev. 2007, 107, 3654−3686
Asymmetric reduction of ethynyl ketones and ethynylketoesters by secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus

Secondary alcohol dehydrogenase (SADH) from Thermoanaerobacter ethanolicus, an NADP-dependent, thermostable oxidoreductase, reduces ethynyl ketones and ethynylketoesters enantioselectively to the corresponding propargyl (propargyl = prop-2-ynyl) alcohols. Ethynyl ketones, in general, are reduced with moderate enantioselectivity (with the exception of 4-methylpent-1-yn-3-one, which gives the (S)-alcohol with >98% ee). Although ethynyl ketones bearing a small (up to n-propyl) alkyl substituent are reduced to (S)-alcohols, larger ethynyl ketones give (R)-alcohols. In contrast, ethynylketoesters are converted to (R)-ethynylhydroxyesters of excellent optical purity. Unexpectedly, isopropyl ethynylketoesters give higher chemical yields and higher enantioselectivities of ethynylhydroxyesters than methyl or ethyl ethynylketoesters. The optically pure ethynylhydroxyesters may serve as useful chiral building blocks for asymmetric synthesis.
Revealed Preferences in a Heterogeneous Population

This paper explores the empirical content of the weak axiom of revealed preference (WARP) for repeated cross-sections. In a heterogeneous population, the fraction of consumers who violate WARP is not point identified but can be bounded. These bounds, as well as some nonparametric refinements, correspond to intuitive behavioral assumptions if there are two goods. With three or more goods, such intuitions break down, and plausible assumptions can have counterintuitive implications. We also provide estimators and confidence regions. The empirical application reveals that in the British Family Expenditure Survey, upper bounds are frequently positive but lower bounds are not significantly so.
“To Give Good Science”: Doing Qualitative Research in the Afterward

This article explores the “afterward” for qualitative research in the ruins of NCLB and its failure to deliver. In the space opened up “after” the dominance of the gold standard bullying and “metric mania” of neo-positivism, I articulate a post-retirement project on the weight of sports in U.S. secondary schools out of a re-engagement with the work of Walter Benjamin. Here my interest is to imagine forward out of troubling the narrow scientism of the recent past of educational research toward a post-qualitative future.
Nonlinear optimal control of spacecraft approaching a tumbling target

Abstract This paper investigates the control of spacecraft to approach to and align with a tumbling target. The potential application is to perform on-orbit autonomous satellite servicing. In order to complete the task, the spacecraft is required to perform large position and attitude maneuvers with sufficient accuracy. In addition, the flexible motion induced by large angular maneuvers needs to be minimized. The primary contribution of this work is to consider the control of position and attitude of rigid body and suppression of flexural deformation in one optimal control framework. The 6-DOF rigid body dynamics and coupled flexible structure dynamics are highly nonlinear and lead to a challenging control problem. The θ – D nonlinear optimal control technique is employed to design a closed-form feedback controller for this problem by finding an approximate solution to the Hamilton–Jacobi–Bellman (HJB) equation through a perturbation process. The closed-form controller offered by this approach is easy to implement onboard especially for this problem with a large state-space. Numerical results show that the proposed controller exhibits good tracking performance even under large moment of inertia uncertainties.
High quality actinide targets

We prepare high quality actinide targets for studies of neutron-induced and charged-particle-induced fission. I report on our efforts to measure fragment energy loss in the target backings and to diagnose the “crud” problem frequently found in 248Cm and 252Cf sources and targets. I discuss the preparation of multi-isotopic targets for the FissionTPC and our efforts to measure the pointing resolution of this device. The issues of target uniformity, chemical composition and radiation stability of the targets are discussed along with problems of high/low specific activity regions in a single target.
Computation of Reinforcing Steel Corrosion Distribution in Concrete Marine Bridge Substructures

Abstract Corrosion conditions prevalent in the partially submerged, reinforced concrete substructures of marine bridges were incorporated into a computer model. The modeled system was an axisymmetr...
Smart Growth and the Transportation-Land Use Connection: What Does the Research Tell Us?

This paper looks at the connection that transportation and land use share and the role this connection has in smart growth efforts. Four assumptions are presented that discuss the impact the highway construction and capacity might have on growth, on congestion, the impact that light rail transit may have on density, and the impact of new urbanism design strategies on automobile use. The paper provides an overview of the theory, research efforts, and current debates associated with the assumptions.