cssi/SciSciGPT-SciSciNet huggingface dataset:
A Note on the Simple Algebra of the Shared Prosperity Indicator

One of the two goals of the World Bank Group's new strategy is to promote shared prosperity, defined as the income growth of the bottom 40 percent of the population. The simple monitoring indicator then is the income per capita of the bottom 40 percent of the population. The growth of this indicator can be decomposed into two components: the change in the share of total income accruing to the bottom 40 percent and the growth of the average income of the total population. This paper presents: (i) a brief discussion of the properties of the indicator; (ii) the simple decomposition in algebraic form; (iii) a graphical method for displaying the combinations of the two components of the decomposition; (iv) simulations of the decomposition for hypothetical countries; and (v) some illustrative data.
Postseismic deformation due to subcrustal viscoelastic relaxation following dip-slip earthquakes

The deformation of the Earth following a dip-slip earthquake is calculated using a three layer rheological model and finite element techniques. The three layers are an elastic upper lithosphere, a standard linear solid lower lithosphere, and a Maxwell viscoelastic asthenosphere-a model previously analyzed in the strike-clip case (Cohen, 1981, 1982). Attention is focused on the magnitude of the postseismic subsidence and the width of the subsidence zone that can develop due to the viscoelastic response to coseismic reverse slip. Detailed analysis for a fault extending from the surface to 15 km with a 45 deg dip reveals that postseismic subsidence is sensitive to the depth to the asthenosphere but is only weakly dependent on lower lithosphere depth. The greatest subsidence occurs when the elastic lithosphere is about 30 km thick and the asthenosphere lies just below this layer (asthenosphere depth = 2 times the fault depth). The extremum in the subsidence pattern occurs at about 5 km from the surface trace of the fault and lies over the slip plane. In a typical case after a time t = 30 tau (tau = Maxwell time) following the earthquake the subsidence at this point is 60% of the coseismic uplift. Unlike the horizontal deformation following a strike slip earthquake, significant vertical deformation due to asthenosphere flow persists for many times tau and the magnitude of the vertical deformation is not necessarily enhanced by having a partially relaxing lower lithosphere.
General tridiagonal random matrix models, limiting distributions and fluctuations

In this paper we discuss general tridiagonal matrix models which are natural extensions of the ones given in Dumitriu and Edelman (J. Math. Phys. 43(11): 5830–5847, 2002; J. Math. Phys. 47(11):5830–5847, 2006). We prove here the convergence of the distribution of the eigenvalues and compute the limiting distributions in some particular cases. We also discuss the limit of fluctuations, which, in a general context, turn out to be Gaussian. For the case of several random matrices, we prove the convergence of the joint moments and the convergence of the fluctuations to a Gaussian family. The methods involved are based on an elementary result on sequences of real numbers and a judicious counting of levels of paths.
Structurally and Stereochemically Diverse Tetrahydropyran Synthesis through Oxidative C ? H Bond Activation

Tetrahydropyrans are core units within a multitude of biologically active natural products, [1] and methods to prepare these structures, which utilize C–H bond functionalization as a prelude to C–C bond-formation are desirable. This approach is both step[2] and atom[3] economical, because the substrate preparation and reactive intermediate generation employ unreactive C–H bonds, rather than conventional leaving groups. We have shown that heterocycles can be formed with high levels of diastereocontrol from benzylic and allylic ethers through the DDQ-mediated (2,3-dichloro-5,6-dicyano-1,4-benzoquinone) oxocarbenium ion formation, and subsequent intramolecular nucleophilic addition. [4] This method is highly complementary to Prins-based methods in the preparation of tetrahydropyrans, [5] and has been validated through its application to natural product synthesis. [6] Additional strategic benefits of this approach include the tolerance of acid labile functional groups towards oxidative conditions, [7] the application of facile etherification reactions to form stable linkages in segment coupling reactions, and the access to versatile unsaturated products. We have shown that this unsaturation provides a route towards a range of structurally and stereochemically diverse tetrahydropyrans through post-cyclization manipulations. Vinylsilane- and alkyne-containing products serve as useful moieties for application in target- and diversity-oriented synthesis.
Small peptides as ligands for catalytic asymmetric alkylations of olefins. Rational design of catalysts or of searches that lead to them

Amino acid-based chiral ligands have been developed for use in Cu-catalyzed enantioselective allylic alkylations and conjugate additions that allow access to optically enriched compounds that are otherwise difficult to prepare. These chiral ligands are easily modified and have been identified through mechanism-based library screening. The data presented point to the significance of the availability of a collection of catalysts, since subtle variations in substrate or nucleophile structure often call for a different optimal chiral ligand. Can a catalyst be truly “rationally designed” or do we design our search pathway that eventually leads us to such a catalyst? What is meant by a “general catalyst”? Do we need a class of effective catalysts instead? These and related questions are addressed in the context of the above studies.
Robust affine structure matching for 3D object recognition

We consider model-based object localization based on local geometric feature matching between the model and the image data. The method is based on geometric constraint analysis, working in transformation space. We present a formal method which guarantees finding all feasible matchings in polynomial time. From there we develop more computationally feasible algorithms based on conservative approximations of the formal method. Additionally, our formalism relates object localization, affine model indexing, and structure from multiple views to one another.
Localization for Wilson Loops in Chern-Simons Theory

We reconsider Chern–Simons gauge theory on a Seifert manifold $M$, which is the total space of a non-trivial circle bundle over a Riemann surface $\Sigma$, possibly with orbifold points. As shown in previous work with Witten, the path integral technique of non-abelian localization can be used to express the partition function of Chern–Simons theory in terms of the equivariant cohomology of the moduli space of flat connections on $M$. Here we extend this result to apply to the expectation values of Wilson loop operators that wrap the circle fibers of $M$ over $\Sigma$. Under localization, such a Wilson loop operator reduces naturally to the Chern character of an associated universal bundle over the moduli space. Along the way, we demonstrate that the stationary-phase approximation to the Wilson loop path integral is exact for torus knots in $S^3$, an observation made empirically by Lawrence and Rozansky prior to this work.
Comparing the Contribution of Teacher Versus Tutor Ratings of Inattentive Behavior in Predicting Mathematics Achievement

The purpose of this study was to assess the relative contribution of teacher and tutor ratings of inattentive behavior in two different instructional settings in predicting students’ performance on fraction concepts and whole-number calculations. Classroom teachers rated each student’s attentive behavior in a whole-class setting and tutors rated each student’s attentive behavior in an intensive small-group setting. The sample was 131 fourth-grade students identified as at risk for developing mathematics difficulties (MD) and randomly assigned to fraction tutoring. Teachers and tutors rated each student’s inattentive behavior in the 10th week of the 12-week intervention period. On average, tutors rated students as more attentive than teachers. Also, tutor ratings had greater predictive power than teacher ratings on fraction concepts, but neither set of ratings uniquely predicted performance on whole-number calculations. Possible explanations for findings and directions for future research are discussed.
A visual investigation of turbulence in stagnation flow about a circular cylinder

A visual investigation of turbulence in stagnation flow around a circular cylinder was carried out in order to gain a physical insight into the model advocated by the corticity-amplification theory. Motion pictures were taken from three different viewpoints, and a frame by frame examination of selected movie strips was conducted. Qualitative and quantitative analyses of the flow events focused on tracing the temporal and spatial evolution of a cross-vortex tube outlined by the entrained smoke filaments. The visualization supplied evidence verifying: (1) the selective stretching of cross-vortex tubes which is responsible for the amplification of cross vorticity and, hence, of streamwise turbulence; (2) the streamwise tilting of stretched cross-vortex tubes; (3) the existence of a coherent array of vortices near the stagnation zone; (4) the interaction of the amplified vorticity with the body laminar boundary layer; and, (5) the growth of a turbulent boundary layer.
PKS and NRPS release mechanisms

Covering: up to September 2009 This review covers the recent literature on the release mechanisms for polyketides and nonribosomal peptides produced by microorganisms. The emphasis is on the novel enzymology and mechanistic insights revealed by the biosynthetic studies of new natural products.
Paleoceanography: A review for the GSA Centennial

The central problem of paleoceanography is the history of the circulation of the ocean. Although speculation about ancient oceanic circulation goes back to the past century, the field of paleoceanography was founded in the 1950s as oxygen-isotope studies suggested that oceanic deep waters were warmer in the past than they are today. Extensive coring of deep-sea sediments by numerous expeditions after World War II was followed by the ocean drilling programs, providing a rich data base. Paleoceanographic interpretations have tried to explain the most obvious changes in sea-floor sediments and their contained fossils: changing paleotemperatures indicated by oxygen isotopes, fluctuations in the calcium carbonate compensation depth, accumulations of organic carbon-rich sediments, and the unexpected abundance of hiatuses in a setting which had been thought to be the ultimate sedimentary sink. The result has been the intriguing discovery that although the positions and circulation of the major surface gyres is generally stable, the deep circulation of the ocean may reverse on a variety of time scales. It has been suggested that formation of North Atlantic Deep Water, which causes the uneven distribution of nutrients, alkalinity, and oxygen in the deep sea today, may have been replaced by formation of North Pacific Deep Water during the last deglaciation, reversing the concentration gradients of nutrients, alkalinity, and oxygen. On a longer time scale, the present general circulation, which is dominated by production of oxygen-rich cold deep water in the subpolar regions today, may have replaced a pre-Oligocene general circulation in which warm, saline, oxygen-poor deep waters were formed in warm seas in the arid zones. Paleoceanography is still in its infancy; many new clues to the history of the ocean are being discovered, and many new ideas about conditions in the past are being developed. The beginning of the next century should see continuing rapid growth and maturation in this exciting new field.
Submilliampere threshold buried-heterostructure InGaAs/GaAs single quantum well lasers grown by selective-area epitaxy

Strained-layer InGaAs-GaAs-AlGaAs single quantum well buried heterostructure lasers grown by selective-area MOCVD are described. Threshold currents of 2.65 mA for an uncoated device and 0.97 mA for a coated device have been obtained. A peak optical output power of 170 mW per uncoated facet for a device with a 4 /spl mu/m active region width was also achieved. Peak emissions wavelengths range from 0.956 to 1.032 /spl mu/m. >
The Death of Socialist Law

Before the collapse of socialism, Western comparative lawyers more or less agreed that socialist law was different from the law of capitalist legal systems. But was it different enough no longer to have a place in the new democracies of Eastern Europe? This review looks at the socialist features of pre-1989 East European law and suggests that Marxist law never existed in the first place; that the Stalinist aspects of socialist law, while not extinct, were not confined to the law of Eastern Europe and thus not necessarily socialist; and that the parental qualities of law in the former Soviet Bloc correspond well not only with the needs of unsettled and impoverished populations in Eastern Europe, but with the modern welfare state in general.
Multiplier ideal sheaves in complex and algebraic geometry

The application of the method of multiplier ideal sheaves to effective problems in algebraic geometry is briefly discussed. Then its application to the deformational invariance of plurigenera for general compact algebraic manifolds is presented and discussed. Finally its application to the conjecture of the finite generation of the canonical ring is explored, and the use of complex algebraic geometry in complex Neumann estimates is discussed.
Bijections Between Multiparking Functions, Dirichlet Configurations, and Descending R-Traversals

There are several combinatorial objects that are known to be in bijection with the spanning trees of a graph G. These objects include G-parking functions, critical configurations of G, and descending traversals of G. In this paper, we extend the bijections to generalizations of all three objects.
Brief psychodynamic treatment of PTSD.

This article describes a brief psychodynamic psychotherapy for adults suffering from PTSD following exposure to a single traumatic event, such as tragic bereavement, assault, or loss of a body part through surgery. It uses a supportive therapeutic relationship to uncover what the specific event and circumstances that follow mean to the individual and the obstacles to normal psychological processing of these events. Using this 12-session treatment model, therapists pay particular attention to the individual's current phase of response and the typical ways that the individual avoids threatening information. Making links among the recent trauma, earlier developmental experiences that may have rendered the individual vulnerable to the development of PTSD, and ways that conflicts are reenacted in the therapeutic dyad, dynamic therapists seek to help traumatized individuals re-establish a sense of coherence and meaning in their lives. A case illustration is provided to demonstrate the phases and techniques in this approach.
Respectful cameras: detecting visual markers in real-time to address privacy concerns

To address privacy concerns with digital video surveillance cameras, we propose a practical, real-time approach that preserves the ability to observe actions while obscuring individual identities. In our proposed respectful cameras system, people who wish to remain anonymous agree to wear colored markers such as a hat or vest. The system automatically tracks these markers using statistical learning and classification to infer the location and size of each face and then inserts elliptical overlays. Our objective is to obscure the face of each individual wearing a marker, while minimizing the overlay area in order to maximize the remaining observable region of the scene. Our approach incorporates a visual color-tracker based on a 9 dimensional color-space by using a probabilistic AdaBoost classifier with axis-aligned hyperplanes as weak-learners. We then use particle filtering to incorporate interframe temporal information. We present experiments illustrating the performance of our system in both indoor and outdoor settings, where occlusions, multiple crossing targets, and lighting changes occur. Results suggest that the respectful camera system can reduce false negative rates to acceptable levels (under 2%).
Can complexity science support the engineering of critical network infrastructures

Considerable attention is now being devoted to the study of "complexity science" with the intent of discovering and applying universal laws of highly interconnected and evolved systems. This paper considers several issues related to the use of these theories in the context of critical infrastructures, particularly the Internet. Specifically, we revisit the notion of "organized complexity" and suggest that it is fundamental to our ability to understand, operate, and design next-generation infrastructure networks. We comment on the role of engineering in defining an architecture to support networked infrastructures and highlight recent advances in the theory of distributed control driven by network technologies.
Spillover Effects of Exchange Rates : A Study of the Renminbi

This paper estimates the impact of China’s exchange rate changes on exports of competitor countries in third markets, which we call the “spillover effect.” We use recent theory to develop an identification strategy in which competition between China and its developing country competitors in specific products and destinations plays a key role. We exploit the variation—afforded by disaggregated trade data—across exporters, importers, product, and time to estimate this spillover effect. We find robust evidence of a statistically and quantitatively significant spillover effect. Our estimates suggest that, on average, a 10 percent appreciation of China’s real exchange rate boosts a developing country’s exports of a typical 4-digit Harmonized System (HS) product category to third markets by about 1.5 to 2 percent. The magnitude of the spillover effect varies systematically with product characteristics as implied by theory.
Crystal growth, structures, and optical properties of the cubic double perovskites Ba2MgWO6 and Ba2ZnWO6

Single crystals of the tungstates Ba2MgWO6 and Ba2ZnWO6 have been grown for the first time. The crystals were prepared with molten potassium carbonate acting as a flux. According to the single-crystal X-ray diffraction structure determination, the compounds crystallize in space group Fm3¯m of the cubic system with a double perovskite structure, A2BB′O6. These structural findings were confirmed with neutron diffraction on polycrystalline samples synthesized by a high-temperature solid-state route. Both sets of diffraction data reveal that the M2+ and W6+ cations are fully ordered on the B and B′ sites. Ba2MgWO6 and Ba2ZnWO6 exhibit room-temperature luminescence with green and yellow emissions, respectively.
Combinatorial Miller-Morita-Mumford classes and Witten cycles

We obtain a combinatorial formula for the Miller-Morita-Mum- ford classes for the mapping class group of punctured surfaces and prove Witten's conjecture that they are proportional to the dual to the Witten cycles. The proportionality constant is shown to be exactly as conjectured by Arbarello and Cornalba (1). We also verify their conjectured formula for the leading coefficient of the polynomial expressing the Kontsevich cycles in terms of the Miller-Morita-Mumford classes. AMS Classification 57N05; 55R40, 57M15
Symmetric Textures in SO(10) and LMA Solution for Solar Neutrinos

A model based on SUSY SO(10) combined with SU(2) family symmetry is constructed. In contrast with the commonly used effective operator approach, 126‐dimensional Higgs fields are utilized to construct the Yukawa sector. R‐parity symmetry is thus preserved at low energies. The symmetric mass textures arising from the left‐right symmetry breaking chain of SO(10) give rise to very good predictions for quark and lepton masses and mixings. The prediction for sin 2β agrees with the average of current bounds from BaBar and Belle. In the neutrino sector, our predictions are in good agreement with results from atmospheric neutrino experiments. Our model accommodates the LMA solution to the solar neutrino anomaly. The prediction of our model for the |Uev3| element in the MNS matrix is close to the sensitivity of current experiments; thus the validity of our model can be tested in the near future. We also investigate the correlation between the |Uev3| element and tan2 θ⊙ in a general two‐zero neutrino mass texture.
Pediatric research regulations under legal scrutiny: Grimes narrows their interpretation.

In Grimes v. Kennedy Krieger Institute, the Maryland Court of Appeals (Maryland’s highest court) considered whether it is possible for investigators or research entities to have a special relationship with subjects, thereby creating a duty of care that could, if breached, give rise to an action in negligence. The research under review, the Lead Abatement and Repair & Maintenance Study, was conducted from 1993 to 1996 by investigators at the Kennedy Krieger Institute (KKI), an affiliate of Johns Hopkins University. After briefly discussing the case at the center of this ruling, I consider how ambiguities within the federal research regulations at 45 C.F.R. § 46 contribute to disagreements among reasonable and informed people of good will about what studies should be approved. I argue that Grimes may be understood as placing restrictions on how these regulations may be interpreted and used.
The Effectiveness of Mass Communication to Change Public Behavior

This article provides an overview of the ways in which mass communication has been used—or can be used—to promote beneficial changes in behavior among members of populations. We use an ecological perspective to examine the ways in which mass media interventions can be used to influence public behavior both directly and indirectly. Mass media interventions that seek to influence people directly—by directly targeting the people burdened by the public health problem of concern and/or the people who influence them—have a long basis in public health history, and recent reviews have clarified our expectations about what can be expected from such approaches. Mass media interventions that seek to influence people indirectly—by creating beneficial changes in the places (or environments) in which people live and work—have equal if not greater potential to promote beneficial changes in population health behaviors, but these are currently less explored options. To have the greatest possible beneficial influence on pu...
Centralization vs. Decentralization in a Multi-Unit Organization: A Computational Model of a Retail Chain as a Multi-Agent Adaptive System

A computational model of a retail chain is developed in which store managers continually search for better practices. Search takes place over a rugged landscape defined over the space of store practices. The main objective of this research is to determine how the amount of discretion given to store managers as to how they run their stores influences the rate of innovation at the store level. We find that greater decentralization enhances firm performance when stores' markets are sufficiently different, the horizon is sufficiently long, and markets are sufficiently stable.
Organizational Management in Workflow Applications – Issues and Perspectives

Business processes automation requires the specification of process structures as well as the definition of resources involved in the execution of these processes. While the modeling of business processes and workflows is well researched, the link between the organizational elements and process activities is less well understood, and current developments in the web services choreography area completely neglect the organizational aspect of workflow applications. The purpose of this paper is to give an overview of the organizational aspects of workflow technology in the context of the workflow life cycle, to provide a review of existing work, and to develop guidelines for the design of a workflow-enabled organization, which can be used by both workflow vendors and users.
Wireless hotspots: current challenges and future directions

In recent years, wireless Interact service providers (WISPs) have established Wi-Fi hotspots in increasing numbers at public venues, providing local coverage to traveling users and empowering them with the ability to access email, Web, and other Internet applications on the move. In this paper, we observe that while the mobile computing landscape has changed both in terms of number and type of hotspot venues, there are several technological and deployment challenges remaining before hotspots can become an ubiquitous infrastructure. These challenges include authentication, security, coverage, management, location services, billing, and interoperability. We discuss existing research, the work of standards bodies, and the experience of commercial hotspot providers in these areas, and then describe compelling open research questions that remain.
Collaborative filtering with information-rich and information-sparse entities

In this paper, we consider a popular model for collaborative filtering in recommender systems. In particular, we consider both the clustering model, where only users (or items) are clustered, and the co-clustering model, where both users and items are clustered, and further, we assume that some users rate many items (information-rich users) and some users rate only a few items (information-sparse users). When users (or items) are clustered, our algorithm can recover the rating matrix with $$\omega (MK \log M)$$?(MKlogM) noisy entries while $$MK$$MK entries are necessary, where $$K$$K is the number of clusters and $$M$$M is the number of items. In the case of co-clustering, we prove that $$K^2$$K2 entries are necessary for recovering the rating matrix, and our algorithm achieves this lower bound within a logarithmic factor when $$K$$K is sufficiently large. Extensive simulations on Netflix and MovieLens data show that our algorithm outperforms the alternating minimization and the popularity-among-friends algorithm. The performance difference increases even more when noise is added to the datasets.
CP Violation in b → s Decays and New Physics Phases

We present new measurements of CP-violation parameters in B0 → ϕK0, , , , , , and decays based on a sample of pairs collected at the ϒ(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. One neutral B meson is fully reconstructed in one of the specified decay channels, and the flavor of the accompanying B meson is identified from its decay products. CP-violation parameters for each of the decay modes are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays. All results are preliminary.
Eigenvalues and Eigenfunctions of the Scalar Laplace Operator on Calabi-Yau Manifolds

A numerical algorithm for explicitly computing the spectrum of the Laplace-Beltrami operator on Calabi-Yau threefolds is presented. The requisite Ricci-flat metrics are calculated using a method introduced in previous papers. To illustrate our algorithm, the eigenvalues and eigenfunctions of the Laplacian are computed numerically on two different quintic hypersurfaces, some 5 × 5 quotients of quintics, and the Calabi-Yau threefold with Z3 × 3 fundamental group of a heterotic standard model. The multiplicities of the eigenvalues are explained in detail in terms of the irreducible representations of the finite isometry groups of the threefolds.
Explicit Versus Implicit Income Insurance

By supplementing income explicitly through payments or implicitly through taxes collected, income-based taxes and transfers make disposable income less variable. Because disposable income determines consumption, policies that smooth disposable income also create welfare improving consumption insurance. With data from the Panel Study of Income Dynamics we find that annual consumption variation is reduced by almost 20 percent due to explicit and implicit income smoothing. Consumption insurance is as important economically as private health or automobile insurance. Although taxes have become an increasingly important source of consumption insurance, the 2001 income-tax reform legislation should have little effect on implicit consumption insurance.
Geographical Diversification in Agriculture: An Applied Case to Western U.S. Wheat Growers

Yield correlations between 380 different counties are calculated for non-irrigated wheat. Using this data, a function is estimated that shows the relationship between correlation and changes in geographic and climate data. In addition movement variables are included added to the specification to capture the impact of moving from one production region to another. A negative relationship was found between changes in latitude, longitude, precipitation, elevation, and temperature. Correlations and longitude and precipitation showed downward sloping concave relationship, whereas correlations and latitude showed downward sloping convex relationships. Changes in latitude and longitude are found to have greatest impact on correlation with elasticities of -1.54 and -1.
Symmetric Subgroups of Gauged Supergravities and AdS String Theory Vertex Operators

We show how the gauge symmetry representations of the massless particle content of gauged supergravities that arise in the AdS/CFT correspondences can be derived from symmetric subgroups to be carried by string theory vertex operators, although explicit vertex operator constructions of the IIB string on AdS remain elusive. Our symmetry mechanism parallels the construction of representations of the Monster group and affine algebras in terms of twisted conformal field theories, and may serve as a guide to a perturbative description of the IIB string on AdS.
Industrial Sponsored Design Projects Addressed by Student Design Teams

We have developed and implemented a four-quarter design sequence starting in the spring of the junior year. The first course focuses on having teams of students take an industrial based project from inception through a conceptual design process culminating in a final design specification. The senior year sequence is structured to have three-five member teams function as a type of “engineering consultant firm” to address externally sponsored projects. The teams initially work with the sponsor to develop a “Product Design Specification (PDS)” as the foundation of the project. The teams then develop the conceptual design of the project during the fall quarter in order to get sponsor approval to move toward final implementation or prototype development during the winter and early spring teams. The course culminates with a day long symposium where each team makes formal presentations of their project and designs to the campus community, the sponsor representatives, and invited guests from the local community and potential industrial sponsors. The paper will present the specifics of the Junior and Senior level courses, brief overviews of the related Sophomore and Junior prerequisite courses, the method of obtaining the industrial sponsors, team formation process, sample projects, and assessment results from the first two offerings of the sequence.
A Model for the Thermodynamic Growth of Sea Ice in Numerical Investigations of Climate

Abstract A model is presented whereby the thickness and extent of sea ice may be predicted in climate simulations. A basic one-dimensional diffusion process is taken to act in the ice, with modifications due to penetration of solar radiation, melting of internal brine pockets, and accumulation of an insulating snow cover. This formulation is similar to that of a previous study by Maykut and Untersteiner, but the introduction of a streamlined numerical method makes the model more suitable for use at each grid point of a coupled atmosphere-ocean model. In spite of its simplicity, the ice model accurately reproduces the results of Maykut and Untersteiner for a wide variety of environmental conditions. In 25 paired experiments, annual average equilibrium thicknesses of ice agree within 24 cm for 75% of the cases; and the average absolute error for all cases is 22 cm. The new model has fewer computational requirements than one layer of ocean in the polar regions, and it can be further simplified if additional ...
Trunk congestion control in heterogeneous circuit switched networks

A circuit-switched network with two types of traffic is modeled as a finite two-dimensional Markov chain. The problem of trunk congestion under different routing schemes is analyzed. It is shown that the trunk reservation technique can be used to alleviate trunk congestion in this heterogeneous traffic environment. It is also shown that two control schemes, namely, the restricted access and preemption, when properly applied, may minimize the blocking of one type of traffic while keeping that of the other at a certain level. Some numerical examples are presented. >
Demonstration of Adaptive Extended Kalman Filter for Low-Earth-Orbit Formation Estimation Using CDGPS

Carrier-phase Di®erential GPS is an ideal sensor for formation °ying missions in low Earth orbit since it provides a direct measure of the relative positions and velocities of the vehicles in the °eet. This paper presents results for a relative navigationlter that achieves centimeter-level precision using measurements from a customized GPS receiver. This work uses a precise, robust extended Kalmanlter that is based on rela- tively simple measurement models and a linear Kep- lerian propagation model. To increase the robustness of thelter in the face of environment uncertainty, the ¯lter is adapted using MMLE algorithms. The adap- tivelter is used to accurately identify the process noise and sensor noise covariance for the system. De- spite the simplicity of thelter, hardware-in-the-loop simulations performed on the Formation Flying Test- bed at the Goddard Space Flight Center demonstrate that thislter can achieve ¼2 cm relative position ac- curacy and <0.5 mm/s relative velocity accuracy for a range of Low Earth Orbit formations.
Behavior in Second-Price Auctions by Highly Experienced eBay Buyers and Sellers

We report on sealed-bid second-price auctions that we conducted on the Internet using subjects with substantial prior experience: they were highly experienced participants in eBay auctions. Unlike the novice bidders in previous (laboratory) experiments, the experienced bidders exhibited no greater tendency to overbid than to underbid. However, even subjects with substantial prior experience tended not to bid their values, suggesting that the non-optimal bidding of novice subjects is robust to substantial experience in non-experimental auctions. We found that auction revenue was not significantly different from the expected revenue the auction would generate if bidders bid their values. Auction efficiency, as measured by the percentage of surplus captured, was substantially lower in our SPAs than in previous laboratory experiments.
THE NATURE OF INTERSTELLAR GAS TOWARD THE PLEIADES REVEALED IN ABSORPTION LINES

We present high-resolution, high signal-to-noise ratio absorption-line observations of CN, Ca ii ,C ai ,C H + ,a nd CH along 20 lines of sight toward members of the Pleiades. The acquired data enable the most detailed study to date of the interaction between cluster stars and the surrounding interstellar gas. Total equivalent widths are consistent with previous investigations, except where weaker features are detected owing to our greater sensitivity. Mean b-values for themolecularspeciesindicatethattowardmostofthePleiades,CHisassociatedwiththeproductionofCH + ratherthan CN. An analysis of radial velocities reveals a kinematic distinction between ionized atomic gas and molecular and neutralgas.Molecularcomponentsarefoundwithvelocitiesinthelocalstandardofrestofeither � +7or � +9.5kms � 1 , withthehighervelocitycomponentsbeingassociatedwiththestrongest absorption. AtomicgastracedbyCaii showsa strong central component at vLSR �þ 7k m s � 1 , exhibiting velocity gradients indicative of cloud-cluster interactions. GasdensityestimatesderivedfrommeasuredCH/CH + columndensityratiosshowgoodagreement withthoseinferred from H2 rotational populations, yieldingtypical values ofn � 50 cm � 3 . Our models donot include the important timedependent effects on CH + formation, which may ultimately be needed to extract physical conditions in these clouds. Subject headingg ISM: abundances — ISM: kinematics and dynamics — ISM: molecules — open clusters and associations: individual (Pleiades)
Do Taxes Explain European Employment? Indivisible Labor, Human Capital, Lotteries, and Savings

Adding generous government supplied benefits to Prescott’s (2002) model with employment lotteries and private consumption insurance causes employment to implode and prevents the model from matching outcomes observed in Europe. To understand the role of a ‘not-so-well-known aggregation theory’ that Prescott uses to rationalize the high labor supply elasticity that underlies his finding that higher taxes on labor have depressed Europe relative to the U.S., this paper compares aggregate outcomes for economies with two arrangements for coping with indivisible labor: (1) employment lotteries plus complete consumption insurance, and (2) individual consumption smoothing via borrowing and lending at a risk-free interest rate. The two arrangements support equivalent outcomes when human capital is not present; when it is present, allocations differ because households’ reliance on personal savings in the incomplete markets model constrains the ‘career choices’ that are implicit in their human capital acquisition plans relative to those that can be supported by lotteries and consumption insurance in the complete markets model. Nevertheless, the responses of aggregate outcomes to changes in tax rates are quantitatively similar across the two market structures. Thus, under both aggregation theories, the high disutility that Prescott assigns to labor is an impediment to explaining European nonemployment and benefits levels. Moreover, while the identities of the nonemployed under Prescott’s tax hypothesis differ between the two aggregation theories, they all seem counterfactual.
IRAS 11590–6452 in BHR 71: A Binary Protostellar System?

New Anglo-Australian Telescope near-infrared and Swedish-ESO Submillimetre Telescope 12CO J = 2 → 1 observations are combined with existing Infrared Space Observatory mid-infrared and Australia Telescope Compact Array centimeter radio continuum observations to examine the protostellar content of the Bok globule BHR 71. Together with observations of Herbig-Haro objects, these data show the following: (1) Two protostellar sources, IRS 1 and IRS 2, with a separation of ~17'' (3400 AU) are located within BHR 71. (2) Each protostar is driving its own molecular outflow. The outflow from IRS 1 is much larger in extent, is more massive, and dominates the CO emission. (3) Both protostars are associated with Herbig-Haro objects and shock-excited 2.122 μm H2 v = 1-0 S(1) emission, which coincide spatially with their CO outflows. (4) IRS 1 is associated with centimeter continuum emission, with a flat or rising spectrum, which is consistent with free-free emission, a signpost of protostellar origin.
Intangible assets: how the interaction of computers and organizational structure affects stock market valuations

An important theme in information systems research is that organizational factors are critical to the success of computer investments. This paper provides broad statistical evidence for this proposition. For our analysis, we have compiled a unique data set of over 1,000 firms which includes the total stock market value of firms, their installed base of computer capital, detailed measures of the organizational structures, and a battery of other factors. Using a theoretically-grounded model, we find that a one dollar increase in a firm’s installed computer capital is associated with an increase in the firm’s stock market valuation of over five dollars, while controlling for all other tangible assets. For this to be equilibrium, the financial markets must believe that each dollar of computer capital is accompanied by an average of over four dollars of intangible assets. We then identify a candidate for these intangible assets: certain organizational characteristics, involving the structure of decisionmaking and the nature of job design, are highly correlated with computer investments. While these organizational characteristics do not appear on a firm’s balance sheet, we find that they lead to higher stock market valuations. Strikingly, firms that combine higher computer investments with these organizational characteristics have disproportionate increases in their market valuations. Our findings are quite robust to a variety of alternative models and the results are generally strengthened when we control for potential reverse causality. We conclude that the contribution of computers to a firm’s market value is increased when they are combined with certain intangible assets, specifically including the cluster of organizational changes that we have identified.
On the translation invariance of wavelet subspaces

An examination of the translation invariance of V0 under dyadic rationals is presented, generating a new equivalence relation on the collection of wavelets. The equivalence classes under this relation are completely characterized in terms of the support of the Fourier transform of the wavelet. Using operator interpolation, it is shown that several equivalence classes are non-empty.
Design of a Wide Input Range DC–DC Converter With a Robust Power Control Scheme Suitable for Fuel Cell Power Conversion

In this paper, an analysis and design of a wide input range dc-dc converter is proposed along with a robust power control scheme. The proposed converter and its control are designed to be compatible with a fuel cell power source, which exhibits 2 : 1 voltage variation as well as a slow transient response. The proposed approach consists of two stages: a three-level boost converter stage cascaded with a current-fed two-inductor boost converter topology, which has a higher voltage gain and provides galvanic isolation from the input source. The function of the front-end boost converter stage is to maintain a constant voltage at the input of the cascaded dc-dc converter to ensure optimal performance characteristics and high efficiency. At the output of the first boost converter, a battery or ultracapacitor energy storage is connected to handle slow transient response of the fuel cell (200 W/min). The robust features of the proposed control system ensure a constant output dc voltage for a variety of load fluctuations, thus limiting the power being delivered by the fuel cell during a load transient. Moreover, the proposed configuration simplifies power management and can interact with the fuel cell controller. Simulation and the experimental results confirm the feasibility of the proposed system.
Hawking radiation via anomaly cancellation for the black holes of five-dimensional minimal gauged supergravity

The anomaly cancellation method proposed by Wilczek et al. is applied to the general charged rotating black holes in five-dimensional minimal gauged supergravity. Thus Hawking temperature and fluxes are found. The Hawking temperature obtained agrees with the surface gravity formula. The black holes have charge and two unequal angular momenta, and these give rise to appropriate terms in the effective U(1) gauge field of the reduced (1+1)-dimensional theory. In particular, it is found that the terms in this U(1) gauge field correspond exactly to the correct electrostatic potential and the two angular velocities on the horizon of the black holes, and so the results for the Hawking fluxes derived here from the anomaly cancellation method are in complete agreement with the ones obtained from integrating the Planck distribution.
Small-scale convection in the subduction zone mantle wedge

Abstract Small-scale convection in the upper mantle can appreciably influence large-scale mantle dynamics and has important implications for geophysical observables such as seismic anisotropy and surface heat flow. We develop numerical models to evaluate the likelihood of small-scale convection in the mantle wedge above subducting slabs. The characteristics of small-scale convection are analyzed using the 3-D single-mode approximation, in which one characteristic wavenumber represents small-scale convective motions with rotational axes parallel to the convergence direction. Numerical simulations are run for a range of characteristic wavenumbers, Rayleigh numbers, and subduction parameters (e.g., slab dip angle, convergence velocity, and downgoing plate age). For each simulation, we quantify the excitation due to small-scale convection and determine under what conditions and characteristic wavenumbers this excitation is maximized. We find that of the parameters examined, mantle wedge viscosity plays the most significant role in dictating the occurrence and strength of small-scale convective motions in the mantle wedge. Numerical models run with subduction parameters similar to that of northeast Japan, where it has been proposed that small-scale convection may be occurring in the mantle wedge, require a mantle wedge viscosity of ∼ 10 18 Pa s for significant small-scale convection to occur.
Statistical inference, Occam's razor, and statistical mechanics on the space of probability distributions

The task of parametric model selection is cast in terms of a statistical mechanics on the space of probability distributions. Using the techniques of low-temperature expansions, I arrive at a systematic series for the Bayesian posterior probability of a model family that significantly extends known results in the literature. In particular, I arrive at a precise understanding of how Occam’s razor, the principle that simpler models should be preferred until the data justify more complex models, is automatically embodied by probability theory. These results require a measure on the space of model parameters and I derive and discuss an interpretation of Jeffreys’ prior distribution as a uniform prior over the distributions indexed by a family. Finally, I derive a theoretical index of the complexity of a parametric family relative to some true distribution that I call the razor of the model. The form of the razor immediately suggests several interesting questions in the theory of learning that can be studied using the techniques of statistical mechanics.
Vocalic context as a condition for nasal coda emergence: aerodynamic evidence

Nasal coda emergence (NCE) (sometimes referred to as ‘restoration’) is the process by which a nasal vowel develops an excrescent nasal coda which may or may not have been present in an earlier form of the spoken language. NCE is operative in the Carioca (Rio de Janeiro) dialect of Brazilian Portuguese (CBP), an Ibero-Romance language with five phonemically nasal vowels. The output of NCE (in this language) is usually a velar nasal. It has been suggested that the process may be a function of tongue position (Hajek 1991: 262). To test the null hypothesis that NCE does not correlate with vowel height or anteriority, aerodynamic (nasal and oral flow) signals were obtained from three speakers of CBP. The speakers uttered words ending in nasal vowels while wearing a circumferentially-vented pneumotach split-flow air mask. For comparative purposes, parallel data were gathered from a Hindi and a French speaker as well. The maximum nasal percentage of total flow and the maximum real nasal flow (in ml/s) were measured for each token, averaged across vowels and, in the case of CBP, across speakers. For CBP, the null hypothesis is rejected, lending support to the alternative: vowel height and posteriority indeed condition the emergence of NCE. This suggests a role for the lowered velum and/or raised tongue body in the development of coda obstruents on nasal vowels.