cssi/SciSciGPT-SciSciNet huggingface dataset:
Identifying Demand with Multidimensional Unobservables: A Random Functions Approach

We explore the identification of nonseparable models without relying on the property that the model can be inverted in the econometric unobservables. In particular, we allow for infinite dimensional unobservables. In the context of a demand system, this allows each product to have multiple unobservables. We identify the distribution of demand both unconditional and conditional on market observables, which allows us to identify several quantities of economic interest such as the (conditional and unconditional) distributions of elasticities and the distribution of price effects following a merger. Our approach is based on a significant generalization of the linear in random coefficients model that only restricts the random functions to be analytic in the endogenous variables, which is satisfied by several standard demand models used in practice. We assume an (unknown) countable support for the the distribution of the infinite dimensional unobservables.
Computer-Based Monitoring in the American Workplace: Surveillance Technologies and Legal Challenges

With the explosion in information technology, deploying desktop Internet access for corporations is becoming common place. Corporate managers are dealing with issues of protecting their corporations from legal exposure, especially in relation to downloading of pornographic or racist material, and from unwanted content. While the reasons offered by employers for doing computer-based monitoring may appear ethical and legal, employers who aggressively monitor must stay current on the laws because they may be liable for multiple violations of federal and state laws. This paper reviews surveillance technologies and discusses different arguments of computer-based monitoring. This is followed by the discussion of related federal and state laws and judicial decisions. The paper concludes with guidelines for developing computer-based monitoring policies.
Arrangements of equal minors in the positive Grassmannian

Abstract We discuss arrangements of equal minors of totally positive matrices. More precisely, we investigate the structure of equalities and inequalities between the minors. We show that arrangements of equal minors of largest value are in bijection with sorted sets, which earlier appeared in the context of alcoved polytopes and Grobner bases. Maximal arrangements of this form correspond to simplices of the alcoved triangulation of the hypersimplex; and the number of such arrangements equals the Eulerian number. On the other hand, we prove in many cases that arrangements of equal minors of smallest value are weakly separated sets. Weakly separated sets, originally introduced by Leclerc and Zelevinsky, are closely related to the positive Grassmannian and the associated cluster algebra. However, we also construct examples of arrangements of smallest minors which are not weakly separated using chain reactions of mutations of plabic graphs.
When is inter-transaction time informative?

Abstract This paper estimates the role of inter-transaction time in price discovery for 100 NYSE-listed firms between 1993 and 2003. We find faster arriving trades move prices more than slower arriving trades across stocks and across time. We further document that the information content of inter-transaction time varies with trading activity, and is weakest for the most actively traded stocks. We then distinguish trades in the same direction as the previous trade from trades in the reverse direction. Our empirical findings document that inter-transaction time is informative for both types of trades, but in opposite directions. Faster arriving trades in the same direction are more informative, whereas faster arriving trades in opposite directions are less informative.
An empirical study of w-cutset sampling for bayesian networks

The paper studies empirically the time-space trade-off between sampling and inference in the cutser sampling algorithm. The algorithm samples over a subset of nodes in a Bayesian network and applies exact inference over the rest. As the size of the sampling space decreases, requiring less samples for convergence, the time for generating each single sample increases. Algorithm w-cutset sampling selects a sampling set such that the induced-width of the network when the sampling set is observed is bounded by w, thus requiring inference whose complexity is exponentially bounded by w. In this paper, we investigate the performance of w-cutset sampling as a function of w. Our experiments over a range of randomly generated and real benchmarks, demonstrate the power of the cutset sampling idea and in particular show that an optimal balance between inference and sampling benefits substantially from restricting the cutset size, even at the cost of more complex inference.
CEO pay and firm performance: dynamics, asymmetries and alternative performance measures

This study explores the dynamic structure of the pay-for- performance relationship in CEO compensation and quantifies the effect of introducing a more complex model of firm financial performance on the estimated performance sensitivity of executive pay. The results suggest that current compensation responds to past performance outcomes, but that the effect decays considerably within two years. This contrasts sharply with models of infinitely persistent performance effects implicitly assumed in much of the empirical compensation literature. We find that both accounting and market performance measures influence compensation and that the salary and bonus component of pay as well as total compensation have become more sensitive to firm financial performance over the past two decades. There is no evidence that boards fail to penalize CEOs for poor financial performance or reward them disproportionately well for good performance. Finally, the data suggest that boards may discount extreme performance outcomes -both high and low - relative to performance that lies within some `normal' band in setting compensation.
Who’s Who? Challenges in Biometric Authentication

A wide variety of systems require reliable personal recognition schemes to either confirm or determine the identity of an individual requesting their services. The purpose of such schemes is to ensure that only a legitimate user, and not anyone else, accesses the rendered services. Examples of such applications include secure access to buildings, computer systems, laptops, cellular phones and ATMs. In the absence of robust personal recognition schemes, these systems are vulnerable to the wiles of an impostor. Biometric recognition, or simply biometrics, refers to the automatic recognition of individuals based on their physiological and/or behavioral characteristics. By using biometrics it is possible to confirm or establish an individual’s identity based on “who she is”, rather than by “what she possesses” (e.g., an ID card) or “what she remembers” (e.g., a password). Current biometric systems make use of fingerprints, hand geometry, iris, retina, face, hand vein, facial thermograms, signature, voice characteristics, palmprint, gait, etc. to establish a person’s identity [1]. Besides bolstering security and discouraging identity fraud, biometric systems also introduce an aspect of user convenience that may not be possible using traditional security techniques. For example, they alleviate the need for a user to “remember” the PINS and passwords associated with multiple applications.
DETERMINANTS OF PARTICIPATION AND CONSUMPTION: THE CASE OF CRAWFISH IN SOUTH LOUISIANA

This study investigates the determinants of crawfish consumption m South Louisiana using a generalized limited dependent variable model that accounts for both participation and consumption decisions. Income, Catholic, white, and household size increase the likelihood of crawfish consumption but not the conditional level of consumption. Education and employment status are among the other household characteristics that determine the conditional level of consumption.
Regulatory Agency Discretion among Competing Industries: Inside the FDA

This article develops a theoretical framework to analyze the variability in Food and Drug Administration (FDA) approval decisions among competing industries, specifically those that produce new brand-name drugs, generic drugs, and medical devices. The theory provides a framework to test empirically for the determinants of FDA approval decisions. These determinants include the agency's budget, congressional preferences, and several proxies for industry interests and consumer interests. Results from the analysis suggest that the agency's response to these determinants varies among the three different industries' approval activities. The patter of variation implies that bureaucratic discretion is highest for the products with the greatest regulatory stringency. This variation in agency responsiveness further suggests that no single theory of regulation can explain the agency's approval decisions among the three industries. Instead, different theories of regulation-such as public interest, capture, or congressional control-are needed to explain different industry approval activities.
From inflation targeting to the euro-peg: A model of monetary convergence for transition economies

Abstract This study proposes a sequence of monetary convergence to the eurozone, based on autonomous monetary policy rather than on an early application of the euro-peg. The gradual adjustment process begins with a relatively strict variant of inflation targeting, followed by flexible inflation targeting, and ends with exchange rate targeting. A model outlining the optimal mode of policy adjustment is presented. The analysis warns against a premature peg to the euro, which may instigate real currency appreciation, large capital inflows and their costly sterilization. The euro-peg can be introduced only when the candidates’ monetary authorities reach a certain degree of “foundational credibility”. The model of monetary convergence is followed by the empirical assessment of inflation targeting in the Czech Republic and Poland.
Confusion of Relative and Absolute Risk in Valuation

Subjects were less willing to pay for government medical insurance for diseases when the number of people who could not be cured was higher, holding constant the number who could be cured. In a second experiment, willingness to pay (from a hypothetical government windfall) for risk reduction was unaffected by whether the risk was described in terms of percentage or number of lives saved, even though subjects knew that the risks in question differed in prevalence. These results are consistent with the findings of Fetherstonhaugh et al., Jenni and Loewenstein, and others. I suggest that these results can be explained in terms of a general tendency to confuse proportions and differences, a confusion that is analogous to other confusions of quantitative dimensions in children, adults, the news media, and perhaps even the epidemiological literature.
A 5-Axis Mini Direct Drive Robot for Teleoperation and Biotechnology

Publisher Summary In recent years, teleoperation has greatly expanded its scope of applications from its beginnings in the nuclear industry and its early expansion into undersea operations. Space and terrestrial biomedical applications are now attracting increasing attention. In both of these areas, in addition to the desirability of removing humans from sources of physical risk, there is increasing interest in miniaturization. In space, economic and other pressures are shifting the emphasis from relatively heavy, high-cost and complex systems, toward low-mass, low-cost systems with fewer functions and higher launch frequency. In surgery, similar pressures are encouraging replacement of traditional operations with endoscopic ones, which are much less invasive. In both space and medical applications, communication links and time delays will play a key role in the overall system design. The design of the UW mini direct-drive robot has been described. The mechanics and electronics are now complete, and closed-loop control of each axis, employing the analog encoder signals, has been demonstrated. Three-axis mini direct-drive robot has been enhanced with two additional direct-drive axes for general positioning and orientation of an axially symmetric tool. The arm has a work volume of about 120 cm 3 and 5-10 μm or better resolution and repeatability. The arm forms an initial prototype for the NASA/University of Washington MicroTrex flight-telerobotics experiment. The contemplated terrestrial applications include handling sub-microliter liquid samples for electrophoresis and micromanipulation with scaled force reflection.
Sensitivity of full-sky experiments to large scale cosmic ray anisotropies

Abstract The two main advantages of space-based observation of extreme energy ( ≳ 5 × 10 19 eV ) cosmic rays (EECRs) over ground based observatories are the increased field of view and the full-sky coverage with nearly uniform systematics across the entire sky. The former guarantees increased statistics, whereas the latter enables a clean partitioning of the sky into spherical harmonics. The discovery of anisotropies would help to identify the long sought origin of EECRs. We begin an investigation of the reach of a full-sky space-based experiment such as EUSO to detect anisotropies in the extreme-energy cosmic-ray sky compared to ground based partial-sky experiments such as the Pierre Auger Observatory and Telescope Array. The technique is explained here, and simulations for a Universe with just two nonzero multipoles, monopole plus either dipole or quadrupole, are presented. These simulations quantify the advantages of space-based, all-sky coverage.
Economically Optimal Determination of the Parameters of np-Control Charts

Two production models are presented for maintaining current control of an industrial process under the surveillance of an np-control chart. The formulated cost function includes the cost of maintaining an np-control chart, search for the assignable caus..
High Frequency Laser‐Based Ultrasound

To obtain micrometer resolution of materials using acoustics requires frequencies around 1 GHz. Attenuation of such frequencies is high, limiting the thickness of the parts that can be characterized. Although acoustic microscopes can operate up to several GHz in frequency, they are used primarily as a surface characterization tool. The use of a pulsed laser for acoustic generation allows generation directly in the part, eliminating the loss of energy associated with coupling the energy from a piezoelectric transducer to the part of interest. The use of pulsed laser acoustic generation in combination with optical detection is investigated for the non‐contact characterization of materials with features that must be characterized to micrometer resolution.
Real Estate Securities and a Filter-based, Short-term Trading Strategy

Anecdotal evidence provides overwhelming support to the belief that sophisticated real estate investors profit by timing long-run real estate cycles. This article examines the investment performanc...
Toward a Normative Theory of Crop Yield Skewness

While the preponderance of empirical studies point to negative crop yield skewness in a wide variety of contexts, the literature provides few clear insights on why this is so. The purpose of this paper is to make three points on the matter. We show formally that statistical laws on aggregates do not suggest a normal yield distribution. We explain that whenever the weather-conditioned mean yield has diminishing marginal product, then there is a disposition toward negative skewness in aggregate yields. This is because a high marginal product in bad weather states stretches out the left tail of the yield distribution relative to that of the weather distribution. Turning to disaggregated yields, we decompose unconditional skewness into weather-conditioned skewness plus two other terms and study each in turn.
Linked determinantal loci and limit linear series

We study (a generalization of) the notion of linked determinantal loci recently introduced by the second author, showing that as with classical determinantal loci, they are Cohen-Macaulay whenever they have the expected codimension. We apply this to prove Cohen-Macaulayness and flatness for moduli spaces of limit linear series, and to prove a comparison result between the scheme structures of Eisenbud-Harris limit linear series and the spaces of limit linear series recently constructed by the second author. This comparison result is crucial in order to study the geometry of Brill-Noether loci via degenerations.
Transient Sulfate Aerosols as a Signature of Exoplanet Volcanism

Abstract Geological activity is thought to be important for the origin of life and for maintaining planetary habitability. We show that transient sulfate aerosols could be a signature of exoplanet volcanism and therefore of a geologically active world. A detection of transient aerosols, if linked to volcanism, could thus aid in habitability evaluations of the exoplanet. On Earth, subduction-induced explosive eruptions inject SO2 directly into the stratosphere, leading to the formation of sulfate aerosols with lifetimes of months to years. We demonstrate that the rapid increase and gradual decrease in sulfate aerosol loading associated with these eruptions may be detectable in transit transmission spectra with future large-aperture telescopes, such as the James Webb Space Telescope (JWST) and European Extremely Large Telescope (E-ELT), for a planetary system at a distance of 10 pc, assuming an Earth-like atmosphere, bulk composition, and size. Specifically, we find that a signal-to-noise ratio of 12.1 and ...
The Irreducible Spine(s) of Undirected Networks

Using closure and neighborhood concepts, we show that within every undirected network, or graph, there is a unique irreducible subgraph which we call its “spine”. The chordless cycles which comprise this irreducible core effectively characterize the connectivity structure of the network as a whole. In particular, it is shown that the center of the network, whether defined by distance or betweenness centrality, is effectively contained in this spine.
Topics in Termination

We generalize the various path orderings and the conditions under which they work, and describe an implementation of this general ordering. We look at methods for proving termination of orthogonal systems and give a new solution to a problem of Zantema's.
Optimal Policy Restrictions on Observable Outcomes

We study the restrictions implied by optimal policy DSGE models for the volatility of observable endogenous variables. Our approach uses a parametric family of singular models to discriminate which volatility sample outcomes have zero probability of being generated by an optimal policy. Thus the set of volatility outcomes generated by the model is not of measure zero even if there are no random deviations from optimal policymaking. This methodology is applied to a new Keynesian business cycle model widely used in the optimal monetary policy literature, and its implications for the assessment of US monetary policy performance over the 1984-2005 period are discussed.
The Castles Project

We describe the goals of the CASTLES (CfA-Arizona-Space-Telescope-LEns-Survey) project including a sample of NICMOS images of gravitational lenses and a brief list of the preliminary findings.
Proceedings of the 2010 ACM workshop on Cloud computing security workshop

Notwithstanding the latest buzzword (grid, cloud, utility computing, SaaS, IaaS, KaaS, PaaS, etc.), large-scale computing and cloud-like infrastructures are here to stay. How exactly they will look like tomorrow is still for the markets to decide, yet one thing is certain: clouds bring with them new untested deployment and associated adversarial models and vulnerabilities. Thus, it is essential that our community becomes involved at this early stage. The Cloud Computing Security Workshop (CCSW) aims to bring together researchers and practitioners in all security aspects of cloud-centric and outsourced computing. The call for papers attracted overwhelming interest from the community with over 34 submissions from Asia, Canada, Europe, and the United States. The program committee accepted 5 full and 9 short papers. Additionally, four distinguished speakers were invited: Leendert van Doorn, AMD Senior Fellow, Eric Grosse, the Google Security Engineering Director, Steve Riley, Amazon Web Services' Sr. Technical Program Manager, and Michael Waidner, IBM Security CTO.
On Hofer Energy of J-holomorphic Curves for Asymptotically Cylindrical J

In this paper, we provide a bound for the generalized Hofer energy of punctured J-holomorphic curves in almost complex manifolds with asymptotically cylindrical ends. As an application, we prove a version of Gromov’s Monotonicity Theorem with multiplicity. Namely, for a closed symplectic manifold (M,!0) with a compatible almost complex structure J and a ball B in M, there exists a constant ~ > 0, such that any J-holomorphic curve ũ passing through the center of B for k times (counted with multiplicity) with boundary mapped to @B has symplectic area ũ 1(B) ũ ⇤!0 > k~, where the constant ~ depends only on (M,!0, J) and the radius of B. As a consequence, the number of times that any closed J-holomorphic curve in M passes through a point is bounded by a constant depending only on (M,!0, J)1 and the symplectic area of ũ. Here J is any !0 compatible smooth almost complex structure on M . In particular, we do not require J to be integrable.
Simultaneous localization, mapping, and manipulation for unsupervised object discovery

We present an unsupervised framework for simultaneous appearance-based object discovery, detection, tracking and reconstruction using RGBD cameras and a robot manipulator. The system performs dense 3D simultaneous localization and mapping concurrently with unsupervised object discovery. Putative objects that are spatially and visually coherent are manipulated by the robot to gain additional motion-cues. The robot uses appearance alone, followed by structure and motion cues, to jointly discover, verify, learn and improve models of objects. Induced motion segmentation reinforces learned models which are represented implicitly as 2D and 3D level sets to capture both shape and appearance. We compare three different approaches for appearance-based object discovery and find that a novel form of spatio-temporal super-pixels gives the highest quality candidate object models in terms of precision and recall. Live experiments with a Baxter robot demonstrate a holistic pipeline capable of automatic discovery, verification, detection, tracking and reconstruction of unknown objects.
Endowments, location or luck ? evaluating the determinants of sub-national growth in decentralized Indonesia

Indonesia's "big bang" decentralization in 2001 shifted much of the responsibility for local economic development from central government to district and city governments, which today number more than 450. But the performance of these districts has varied widely. This paper attempts to understand the determinants of sub-national (district/city) growth in Indonesia and map how these determinants have changed since before the 1997/98 economic crisis. The authors exploit a rich dataset that includes a wide range of district-level characteristics, including education, population, cultural, economic, and infrastructure variables, as well as a set of variables relating to distance, to try to explain growth. The analysis finds that, after accounting for differences in other variables, poorer districts tend to grow faster than better off districts. Similarly, there is evidence of spatial divergence, in the sense that districts tend to grow faster if their neighbors are growing quickly. However, the quality of the existing district-level data makes it difficult to identify whether endowments or factors related to distance are systematically associated with growth.
Matroidal degree-bounded minimum spanning trees

We consider the minimum spanning tree (MST) problem under the restriction that for every vertex v, the edges of the tree that are adjacent to v satisfy a given family of constraints. A famous example thereof is the classical degree-bounded MST problem, where for every vertex v, a simple upper bound on the degree is imposed. Iterative rounding/relaxation algorithms became the tool of choice for degree-constrained network design problems. A cornerstone for this development was the work of Singh and Lau [19], who showed that for the degree-bounded MST problem, one can find a spanning tree violating each degree bound by at most one unit and with cost at most the cost of an optimal solution that respects the degree bounds.However, current iterative rounding approaches face several limits when dealing with more general degree constraints, where several linear constraints are imposed on the edges adjacent to a vertex v. For example, when a partition of the edges adjacent to v is given and only a fixed number of elements can be chosen out of each set of the partition, current approaches might violate each of the constraints at v by a constant, instead of violating the whole family of constraints at v by at most a constant number of edges. Furthermore, previous iterative rounding approaches are not suited for degree constraints where some edges are in a super-constant number of constraints.We extend iterative rounding/relaxation approaches, both conceptually as well as in their analysis, to address these limitations. Based on these extensions, we present an algorithm for the degree-constrained MST problem where for every vertex v, the edges adjacent to v have to be independent in a given matroid. The algorithm returns a spanning tree of cost at most OPT, such that for every vertex v, it suffices to remove at most 8 edges from the spanning tree to satisfy the matroidal degree constraint at v.
Flight Research and Validation Overview

An overview of the content and status of the "Flight Research and Validation" technical challenge area of the Fundamental Aeronautics Program (FAP) Supersonics Project is presented.
Cointegration and Price Discovery between Equity and Mortgage REITs

This study analyzes the relationship between equity and mortgage real estate investment trust (REIT) stock prices by performing cointegration tests and causality tests, and estimating an error corr...
Coupling between microstrip lines embedded in polyimide layers for 3D-MMICs on Si

Three-dimensional circuits built upon multiple layers of polyimide are required for constructing Si-SiGe monolithic microwave/millimeter-wave integrated circuits on CMOS (low resistivity) Si wafers. However, the closely spaced transmission lines are susceptible to high levels of coupling, which degrades circuit performance. In this paper, Finite Difference Time Domain (FDTD) analysis and measured characteristics of novel shielding structures that significantly reduce coupling between embedded microstrip lines are presented.
Facets of the balanced minimal evolution polytope

The balanced minimal evolution (BME) method of creating phylogenetic trees can be formulated as a linear programming problem, minimizing an inner product over the vertices of the BME polytope. In this paper we undertake the project of describing the facets of this polytope. We classify and identify the combinatorial structure and geometry (facet inequalities) of all the facets in dimensions up to five, and classify even more facets in all dimensions. A full set of facet inequalities would allow a full implementation of the simplex method for finding the BME tree-although there are reasons to think this an unreachable goal. However, our results provide the crucial first steps for a more likely-to-be-successful program: finding efficient relaxations of the BME polytope.
Age-Related Changes in MicroRNA Expression and Pharmacogenes in Human Liver.

Developmental changes in the liver can significantly impact drug disposition. Due to the emergence of microRNAs (miRNAs) as important regulators of drug disposition gene expression, we studied age-dependent changes in miRNA expression. Expression of 533 miRNAs was measured in 90 human liver tissues (fetal, pediatric (1-17 years), and adult (28-80 years); n=30 each). 114 miRNAs were upregulated and 72 were downregulated from fetal to pediatric, and 2 and 3, respectively, from pediatric to adult. Among the developmentally changing miRNAs, 99 miRNA-mRNA interactions were predicted or experimentally validated (e.g. hsamiR-125b-5p-CYP1A1; hsa-miR-34a-5p-HNF4A). In human liver samples (n=10 each), analyzed by RNA-sequencing, significant negative correlations were observed between the expression of >1000 miRNAs and mRNAs of drug disposition and regulatory genes. Our data suggest a mechanism for the marked changes in hepatic gene expression between the fetal and pediatric developmental periods, and support a role for these age-dependent miRNAs in regulating drug disposition.
Are men shortchanged on health? Perspective on life expectancy, morbidity, and mortality in men and women in the United States

Summary Background: Significant gender disparities exist in life expectancy and major disease morbidity. There is an urgent need to understand the major issues related to men’s health that contributes to these significant disparities. It is hypothesized that men have higher and earlier morbidities, in addition to behavioral factors that contribute to their lower life expectancy. Methods: Data was collected from CDC: Health United States, 2007; American Heart Association, American Obesity Association, and American Cancer Society. Results: Men have lower life expectancy than women in most countries around the world including United States. This gender disparity is consistent regardless of geography, race and ethnicity. More men die of 12 out of the 15 leading causes of death than women. In addition, men have higher morbidity and mortality in coronary heart disease (CHD), hypertension, diabetes, and cancer. Conclusions: Men’s lower life expectancy may be explained by biological and clinical factors such as the higher incidence of cardiovascular metabolic disease and cancer. In the context of public health, raising awareness of cardiovascular and metabolic health is needed to reduce the gender disparity. In addition, consideration of preventive and early detection/intervention programs may improve men’s health.
A Test of the Particle Paradigm in N-Body Simulations

We present results of tests of the evolution of small "fluid elements" in cosmological N-body simulations, to examine the validity of their treatment as particles. We find that even very small elements typically collapse along one axis while expanding along another, often to twice or more their initial comoving diameter. This represents a possible problem for high-resolution uses of such simulations.
Optimal realizations of controlled unitary gates

The controlled-not gate and the single qubit gates are considered elementary gates in quantum computing. It is natural to ask how many such elementary gates are needed to implement more elaborate gates or circuits. Recall that a controlled-U gate can be realized with two controlled-not gates and four single qubit gates. We prove that this implementation is optimal if and only if the matrix U satisfies the conditions tr U ≠ 0, tr(UX) ≠ 0, and det U ≠ 1. We also derive optimal implementations in the remaining non-generic cases.
On Quantum Statistical Mechanics of a Schwarzschild Black Hole

Quantum theory of geometry, developed recently in the framework of non-perturbative quantum gravity, is used in an attempt to explain thermodynamics of Schwarzschild black holes on the basis of a microscopical (quantum) description of the system. We work with the formulation of thermodynamics in which the black hole is enclosed by a spherical surface B and a macroscopic state of the system is specified by two parameters: the area of the boundary surface and a quasilocal energy contained within it. To derive thermodynamical properties of the system from its microscopics we use the standard statistical mechanical method of Gibbs. Under a certain number of assumptions on the quantum behavior of the system, we find that its microscopic (quantum) states are described by states of quantum Chern-Simons theory defined by sets of points on B with spins attached. The level of the Chern-Simons theory turns out to be proportional to the horizon area of the black hole measured in Planck units. The statistical mechanical analysis turns out to be especially simple in the case when the entire interior of B is occupied by a black hole. We find in this case that the entropy contained within B, that is, the black hole entropy, is proportional to the horizon surface area.
A Class of Continued Radicals

We compute the limits of a class of continued radicals, extending the results of a previous note in which only periodic radicals of the class were considered.
Immunotherapy for Alzheimer’s disease

In the year 1999, a vaccine approach was found to reduce amyloid deposits in transgenic mice overproducing the amyloid precursor protein. This was followed closely by demonstrations that vaccines or passive immunotherapy could rescue memory deficits in these mice. Initial human clinical trials revealed apparent autoimmune reactions in a subset of patients, but also some cases of cognitive benefit and amyloid clearance. Further work with passive immunotherapy in mouse models confirmed exceptional clearing abilities of anti-amyloid antibodies even in older mice. However, in parallel with parenchymal amyloid clearance was the appearance of microhaemorrhages and increased vascular amyloid deposition. Additional clinical trials with passive immunotherapy confirmed occasional appearance of microhaemorrhage and occurrence of vasogenic oedema in some patients, particularly those with the apolipoprotein E4 genotype. Recent data with positron emission tomography demonstrates trial participants passively immunized with anti-As antibodies have reduced signals with amyloid binding ligands after 18 months of therapy. Several anti-As immunotherapies have reached phase 3 testing, and immunotherapy is likely to be the first test of the amyloid hypothesis of Alzheimer's disease. Identifying antibody variants that retain amyloid clearance with fewer adverse reactions remains a major focus of translational research in this area.
Symmetry principles for string theory

The gauge symmetries that underlie string theory arise from inner automorphisms of the algebra of observables of the associated conformal field theory. In this way it is possible to study broken and unbroken symmetries on the same footing, and exhibit an infinite-dimensional supersymmetry algebra that includes space-time diffeomorphisms and an infinite number of spontaneously broken level-mixing symmetries. We review progress in this area, culminating in the identification of a weighted tensor algebra as a subalgebra of the full symmetry. We also briefly describe outstanding problems. Talk presented at the Gursey memorial conference, Istanbul, Turkey, June, 1994.
Optimal generation dispatch with high penetration of photovoltaic generation

Power system operation practices are changing with the addition of renewable energy resources such as photovoltaic (PV) sources. The diverse and intermittent nature of these resources demands new operation strategies to ensure system reliability. As more PV units are added to power systems, the power generated by conventional generation resources should be reduced to accommodate these new resources. The reduction in fossil-fired generation allows realization of benefits in the sustainability of the generation mix. While some of the conventional generating units are retired, some should be retained for system reliability. This paper investigates the impact of generation redispatch or generation displacement in systems with high PV penetration. Comparing various study scenarios, a method based on regression techniques and Chebyshev's inequality is introduced in this paper. This method is used to calculate the dispatch or displacement ratio of the conventional generators for optimal steady state and transient response of the system. Recommendations are formulated based on an actual large-scale power system in the western United States.
Functorial data migration

In this paper we present a simple database definition language: that of categories and functors. A database schema is a small category and an instance is a set-valued functor on it. We show that morphisms of schemas induce three ''data migration functors'', which translate instances from one schema to the other in canonical ways. These functors parameterize projections, unions, and joins over all tables simultaneously and can be used in place of conjunctive and disjunctive queries. We also show how to connect a database and a functional programming language by introducing a functorial connection between the schema and the category of types for that language. We begin the paper with a multitude of examples to motivate the definitions, and near the end we provide a dictionary whereby one can translate database concepts into category-theoretic concepts and vice versa.
Large-Scale Fission Product Containment Tests

The Containment Systems Experiment (CSE) program is reviewed, with emphasis on the inherent processes that remove fission products from containment atmospheres and reduce their leakage to the envir...
Will Jets Identify the Progenitors of Type Ia Supernovae

We use the fact that a Type Ia supernova has been serendipitously discovered near the jet of the active galaxy 3C 78 to examine the question of whether jets can enhance accretion onto white dwarfs. One interesting outcome of such a jet-induced accretion process is an enhanced rate of novae in the vicinity of jets. We present results of observations of the jet in M87, which appear to have indeed discovered 11 novae in close proximity to the jet. We show that a confirmation of the relation between jets and novae and Type Ia supernovae can finally identify the elusive progenitors of Type Ia supernovae.
Enhancing and Implementing Fully Transparent Internet Voting

Voting over the internet has been the focus of significant research with the potential to solve many problems. Current implementations typically suffer from a lack of transparency, where the connection between vote casting and result tallying is seen as a black box by voters. A new protocol was recently proposed that allows full transparency, never obfuscating any step of the process, and splits authority between mutually-constraining conflicting parties. Achieving such transparency brings with it challenging issues. In this paper we propose an efficient algorithm for generating unique, anonymous identifiers (voting locations) that is based on the Chinese Remainder Theorem, we extend the functionality of an election to allow for races with multiple winners, and we introduce a prototype of this voting system implemented as a multiplatform web application.
Aspirations, health and the cost of inequality

How does inequality motivate people and at what cost? In a model of perpetual youth, people have heterogeneous upward-looking aspirations. They value their consumption relative to the conditional mean of those above them in the distribution; their survival depends on health capital produced from time investment and health goods. Higher fundamental inequality, working through the aspirations gap, motivates people to work and save more. Economic outcomes improve but income and consumption inequality worsen because the poor have less capacity to respond on the labor market. By diverting resources from health production, aspirations also worsen mortality, especially for the poor. Though relative income has a strong negative effect on personal health, inequality has a weak effect on population health, explaining an empirical puzzle on the relative income and health gradient.
Quantum communication complexity of block-composed functions

A major open problem in communication complexity is whether or not quantum protocolscan be exponentially more efficient than classical ones for computing a total Booleanfunction in the two-party interactive model. Razborov's result (Izvestiya: Mathematics,67(1):145-159, 2002) implies the conjectured negative answer for functions F of thefollowing form: F(x, y) = fn(x1 ċ y1, x2 ċ y2, ..., xn ċ yn), where fn is a symmetric Booleanfunction on n Boolean inputs, and xi, yi are the i'th bit of x and y, respectively. Hisproof critically depends on the symmetry of fn. We develop a lower-bound method that does not require symmetry and prove theconjecture for a broader class of functions. Each of those functions F is the "block-composition" of a "building block" gk : {0, 1}k × {0, 1}k → {0, 1}, and an fn : {0, 1}n →{0, 1}, such that F(x, y) = fn(gk(x1, y1), gk(x2, y2), ..., gk(xn, yn)), where xi and xi arethe i'th k-bit block of x, y ∈ {0, 1}nk, respectively. We show that as long as gk itselfis "hard" enough, its block-composition with an arbitrary fn has polynomially relatedquantum and classical communication complexities. For example, when gk is the InnerProduct function with k = Ω(log n), the deterministic communication complexity of itsblock-composition with any fn is asymptotically at most the quantum complexity to thepower of 7.
Combinatorial Interpretations for Rank-Two Cluster Algebras of Affine Type

Fomin and Zelevinsky show that a certain two-parameter family of rational recurrence relations, here called the $(b,c)$ family, possesses the Laurentness property: for all $b,c$, each term of the $(b,c)$ sequence can be expressed as a Laurent polynomial in the two initial terms. In the case where the positive integers $b,c$ satisfy $bc 4$, the recurrence is related to Kac-Moody rank $2$ Lie algebras of general type. Here we investigate the borderline cases $bc=4$, corresponding to Kac-Moody Lie algebras of affine type. In these cases, we show that the Laurent polynomials arising from the recurence can be viewed as generating functions that enumerate the perfect matchings of certain graphs. By providing combinatorial interpretations of the individual coefficients of these Laurent polynomials, we establish their positivity.
Bounding search space size via (Hyper)tree decompositions

This paper develops a measure for bounding the performance of AND/OR search algorithms for solving a variety of queries over graphical models. We show how drawing a connection to the recent notion of hypertree decompositions allows to exploit determinism in the problem specification and produce tighter bounds. We demonstrate on a variety of practical problem instances that we are often able to improve upon existing bounds by several orders of magnitude.
Changes in the Appalachian Wage Gap, 1970 to 2000

Since at least 1960, Appalachia has had lower wages, employment rates, and educational attainment than the rest of the country. Using a sample from the Integrated Public Use Microdata Series Census project, the author identifies factors affecting the wage gap between 1970 and 2000. The author finds that increases in educational attainment in Appalachia are counterbalanced by increasing returns to observable and unobservable skill, the decline of the manufacturing industry, and rising wage dispersion, leaving the wage gap for full-time workers in 2000 at essentially the same levels as 1970.
Human resource information systems: a current assessment

Human resource information systems (HRIS) have become a major MIS subfunction within the personnel areas of many large corporations. This article traces the development of HRIS as an entity independent of centralized MIS, assesses its current operation and technological base, and considers its future role in the firm, especially its relationship to the centralized MIS function. The results of a survey of HRIS professionals from 171 U.S. corporations are described in order to provide an overview of the current design, operations, and effectiveness of HRIS. The findings of the survey are discussed in terms of their implications for management of human resource information systems.
Two additions to the new class of low accretion rate magnetic binaries

Two new magnetic white dwarf accretion binaries with extremely low mass transfer rates have been discovered in the course of the Sloan Digital Sky Survey. Measured magnetic fields are 42 and 57 MG, and one system orbits with a period of just 82 minutes. The new systems therefore significantly expand the range in properties exhibited by the small class. The measured accretion rates are very low, 0.6-5 × 10-13 M☉ yr-1, and multiple visits spanning more than a year confirm that this is not a short-lived characteristic. It is becoming increasingly clear that the low- magnetic white dwarf binaries accrete by nearly complete magnetic capture of the stellar wind from the secondary star rather than by Roche lobe overflow. The accretion rates therefore provide some of the first realistic estimates of the total wind loss rates from M dwarfs. Although one or more of the eight systems known to date may be interrupted or possibly even extinct Polars, several lines of evidence suggest that most are pre-Polars whose evolution has not yet brought the secondaries into contact with their Roche surfaces. Considering the difficulties of identifying binaries over a wide range in field strength and accretion rate, it is quite possible that the space density of wind-accreting magnetic binaries exceeds that of the classical X-ray-emitting, Roche lobe overflow Polars.
Subalgebras of the Fomin---Kirillov algebra

The Fomin---Kirillov algebra $${\mathcal {E}}_n$$En is a noncommutative quadratic algebra with a generator for every edge of the complete graph on n vertices. For any graph G on n vertices, we define $${{\mathcal {E}}_G}$$EG to be the subalgebra of $${\mathcal {E}}_n$$En generated by the edges of G. We show that these algebras have many parallels with Coxeter groups and their nil-Coxeter algebras: for instance, $${\mathcal {E}}_G$$EG is a free $${\mathcal {E}}_H$$EH-module for any $$H\subseteq G$$H⊆G, and if $${\mathcal {E}}_G$$EG is finite-dimensional, then its Hilbert series has symmetric coefficients. We determine explicit monomial bases and Hilbert series for $${\mathcal {E}}_G$$EG when G is a simply laced finite Dynkin diagram or a cycle, in particular showing that $${\mathcal {E}}_G$$EG is finite-dimensional in these cases. We also present conjectures for the Hilbert series of $${\mathcal {E}}_{\tilde{D}_n}$$ED~n, $${\mathcal {E}}_{\tilde{E}_6}$$EE~6, and $${\mathcal {E}}_{\tilde{E}_7}$$EE~7, as well as the graphs G on six vertices for which $$\mathcal {E}_G$$EG is finite-dimensional.
Four types of integration in disability identity development

Integration is a recurrent theme in classic theories of personality development, reflecting the perennial human struggle to resolve opposing pulls toward separation and unity. Identity development is examined in this paper as a particular case of the striving for integration on both individual and group levels. In the context of minority identity development, the steps toward achieving a sound disabiltiy identity are discussed with respect to intrapsychic, interpersonal, and social dynamics. Four types of integration underlying disability identity development are delineated with examples: (1) 'coming to feel we belong' (integrating into society); (2) 'coming home' (integrating with the disability community); (3) 'coming together' (internally integrating our sameness and differentness); and (4) 'coming out' (integrating how we feel with how we present ourselves). The paper ends with a discussion of the significance of this integration process for personal empowerment and disability rights activism. © 1997 Elsevier Science Ireland Ltd.