cssi/SciSciGPT-SciSciNet huggingface dataset:
Explorations in parallel distributed processing: a handbook of models, programs, and exercises

This book presents the official, formal definition of the programming language ML including the rules for grammar and static and dynamic semantics. ML is the most well-developed and prominent of a new group of functional programming languages. On the cutting edge of theoretical computer science, ML embodies the ideas of static typing and polymorphism and has also contributed a number of novel ideas to the design of programming languages.Contents: Syntax of the Core. Syntax of Modules. Static Semantics for the Core. Static Semantics for Modules. Dynamic Semantics for Modules. Programs.Appendixes: Derived Forms. Full Grammar. The Initial Static Basis. The Initial Dynamic Basis. The Development of ML.
Forecasting currency prices using a genetically evolved neural network architecture

Abstract In this paper, a hybrid system combining neural networks and genetic training is designed to forecast the three-month spot rate of exchange for four currencies: the British pound, the German mark, the Japanese yen, and the Swiss franc. The networks' forecasts are compared to the predictions made by the forward and futures rates, and are evaluated based on their degree of accuracy and their ability to correctly forecast the direction of the change in the exchange rate movement.
Standard definitions for sound levels in the ocean

Measurements and calculations in underwater and bio-acoustics should use for the units of the primary reference quantities the International System of Units commonly referred to as SI metric. Relative levels are important quantities provided the reference is clearly specified and the modifier to the term level is consistent with the units of the reference quantity. In particular it is necessary to distinguish between pressure, power, and energy references. These reference quantities should have clearly defined SI-metric (mks) units. The absolute value of the power or intensity should be parenthetically included. >
A Novel Power-Bearing Approach and Asymptotically Optimum Estimator for Target Motion Analysis

The problem of target motion analysis (TMA) has been extensively investigated using bearing-only (BO), Doppler-bearing (DB), and other measurement data. For radio frequency (RF) emitters, signal powers follow the well-known path loss law that can be utilized to aid localization and target tracking in BO-TMA, leading to the novel power-bearing (PB) approach as proposed in this paper. Our main contribution lies in the proof of the asymptotic optimality of the total least-squares (TLS) algorithm for PB-TMA under some mild condition. The Cramer-Rao lower bound (CRLB) is employed to demonstrate the performance improvements of the PB-TMA over the BO-TMA. Our work shows the promise of the PB-TMA approach for RF signals.
Optimal Defaults and Active Decisions

Defaults often have a large influence on consumer decisions. We identify an overlooked but practical alternative to defaults: requiring individuals to make an explicit choice for themselves. We study such "active decisions" in the context of 401(k) saving. We find that compelling new hires to make active decisions about 401(k) enrollment raises the initial fraction that enroll by 28 percentage points relative to a standard opt-in enrollment procedure, producing a savings distribution three months after hire that would take 30 months to achieve under standard enrollment. We also present a model of 401(k) enrollment and derive conditions under which the optimal enrollment regime is automatic enrollment (i.e., default enrollment), standard enrollment (i.e., default non-enrollment), or active decisions (i.e., no default and compulsory choice). Active decisions are optimal when consumers have a strong propensity to procrastinate and savings preferences are highly heterogeneous. Financial illiteracy, however, favors default enrollment over active decision enrollment.
Sums and differences of correlated random sets

Many questions in additive number theory (Goldbach's conjecture, Fermat's Last Theorem, the Twin Primes conjecture) can be expressed in the language of sum and difference sets. As a typical pair contributes one sum and two differences, we expect |A−A|>|A+A|for finite sets A. However, Martin and O'Bryant showed a positive proportion of subsets of {0,…,n} are sum-dominant. We generalize previous work and study sums and differences of pairs of correlated sets (A,B)(a∈{0,…,n} is in A with probability p, and a goes in B with probability_(ρ1) if a∈A and probability_(ρ2)if a∉A). If |A+B|>|(A−B)∪(B−A)|, we call (A,B) a sum-dominant (p,_(ρ1,ρ2))-pair. We prove for any fixed ρ→=(p,ρ1,ρ2) in (0,1)^3, (A,B) is a sum-dominant (p,_(ρ1,ρ2))-pair with positive probability, which approaches a limit P(ρ→). We investigate p decaying with n, generalizing results of Hegarty–Miller on phase transitions, and find the smallest sizes of MSTD pairs.
Effect of Fuel Moisture Content on Biomass-IGCC Performance

The moisture level in biomass fuels potentially impacts efficiency in conversion to power. This paper examines the efficiency and net power output of a fluidized bed gasifier-combined cycle with flue gas drying for a range of as-received raw biomass moisture contents and levels of pregasification drying. Due to the lack of empirical data available, a modeling approach is used to simulate the effect ofvarying moisture content in the gasifier feed biomass. For a specified as-received biomass moisture content, drying prior to gasification increases overall efficiency, but the gains in efficiency decrease with increasing levels of drying. For a specified post-dryer gasifier feed moisture content, cycle efficiency and power output increase with decreasing as-received biomass moisture down to 30 percent, below which the change in cycle performance is negligible.
Rhodium(III)-catalyzed intramolecular hydroarylation, amidoarylation, and Heck-type reaction: three distinct pathways determined by an amide directing group.

Three different Rh(III)-catalyzed reaction pathways of a wide variety of tethered alkenes can be accessed through the change of the amide directing group. This provides an efficient route to a myriad of complex polycyclic products, many containing newly-formed all-carbon quaternary centers. Amidoarylations can highly diastereoselectively deliver products with up to three contiguous stereocenters.
An almost linear time algorithm for finding Hamilton cycles in sparse random graphs with minimum degree at least three

We describe an algorithm for finding Hamilton cycles in random graphs. Our model is the random graph G=Gn,mi¾?i¾?3. In this model G is drawn uniformly from graphs with vertex set [n], m edges and minimum degree at least three. We focus on the case where m = cn for constant c. If c is sufficiently large then our algorithm runs in On1+o1 time and succeeds w.h.p. © 2014 Wiley Periodicals, Inc. Random Struct. Alg., 47, 73-98, 2015
The Gulf Stream Voyage: using real time data in the classroom

The Gulf Stream Voyage is an Internet-based multidisciplinary project which utilizes both real time data and primary source materials to help guide students to discover the science and history of the Gulf Stream. There are several advantages of using real time data in the classroom including: the infusion of inquiry-based learning, fostering problem solving skills, addressing several learning styles, and student relevance.
Limit results on pattern entropy

We determine the entropy rate of patterns of certain random processes including all finite-entropy stationary processes. For independent and identically distributed (i.i.d.) processes, we also bound the speed at which the per-symbol pattern entropy converges to this rate, and show that patterns satisfy an asymptotic equipartition property. To derive some of these results we upper bound the probability that the nth variable in a random process differs from all preceding ones.
Emerging Supramolecular Chemistry of Gases

Molecular recognition of gases is an emerging area of chemistry. Supramolecular chemistry helps us to understand how gases interact with biological molecules and offers delicate insights into the mechanisms of their physiological activity. Principles of molecular recognition have been used for gas sensing, and have provided fundamental knowledge about the structure and dynamics of receptor-analyte complexes, and novel materials for gas sensing and storage have been developed. Supramolecular chemistry is also enabling us to learn how to transform gases into synthetically useful reagents. The rational design of novel catalysts for gas conversion and, more recently, encapsulation complexes with gases open novel directions in preparative synthetic chemistry.
Bayesian implementation in exchange economies with state dependent preferences and feasible sets

This paper considers Bayesian and Nash implementation in exchange economic environments with state dependent preferences and feasible sets. We fully characterize Bayesian implementability for both diffuse and non-diffuse information structures. We show that, in exchange economic environments with three or more individuals, a social choice set is Bayesian implementable if and only if closure, non-confiscatority, Bayesian monotonicity, and Bayesian incentive compatibility are satisfied. As such, it improves upon and contains as special cases previously known results about Nash and Bayesian implementation in exchange economic environments. We show that the individual rationality and continuity conditions, imposed in Hurwicz et al. [12], can be weakened to the non-confiscatority and can be dropped, respectively, for Nash implementation. Thus we also give a full characterization for Nash implementation when endowments and preferences are both unknown to the designer.
Applications of the MEVVA high current metal ion source

A new kind of ion source has been developed in which a MEtal Vapor Vacuum Arc (MEVVA) is used to produce the plasma from which the ion beam is extracted. The novel and exciting feture of this source is the very high metal ion beam current attainable. A total ion beam current of over 1 Ae has been extracted from the embodiment of the concept that we are presently using, and this is not a limit of the method. The source was developed to upgrade the uranium ion beam intensity of the Bevatron, LBL's heavy ion synchrotron, for basic nuclear physics research. Other important applications include its use within the Heavy Ion Fusion research effort; for ion implantation; and for other basic research uses. In this paper the source is described briefly, its performance outlined, and its potential and limitations for a variety of applications is discussed.
Poroelastic fluid effects on shear for rocks with soft anisotropy

SUMMARY A general analysis of poroelasticity for vertical transverse isotropy (VTI) shows that four eigenvectors are pure shear modes with no coupling to the pore-fluid mechanics. The remaining two eigenvectors are linear combinations of pure compression and uniaxial shear, both of which are coupled to the fluid mechanics. After reducing the problem to a 2 × 2 system, the analysis shows in a relatively elementary fashion how a poroelastic system with isotropic solid elastic frame, but with anisotropy introduced only through the poroelastic coefficients (and, therefore, termed soft anisotropy), interacts with the mechanics of the pore fluid and produces shear dependence on fluid properties in the overall poroelastic system. The analysis shows, for example, that this effect is always present (though sometimes small in magnitude) in the systems studied and can be comparatively large (on the order of 10 to 20 per cent) for wave propagation studies in some rocks, including Sierra White granite and Spirit River sandstone. Some of the results quoted here are obtained by using a new product formula relating local bulk and uniaxial shear energy to the product of the two eigenvalues that are coupled to the fluid mechanics. This product formula was first derived in prior work. The results obtained here are observed to be useful both for explaining difficult to reconcile laboratory wave propagation (especially ultrasonic) data showing that the shear modulus exhibits clear dependence on fluid content and also for benchmarking of poroelastic codes.
Eliminating redundant primitives from set-theoretic solid models by a consideration of constituents

Set-theoretic solid models often contain redundant primitives, which slow down rendering and other processes. They are not simple to remove, especially as there can be alternative eliminations that may not be equally desirable. Existing techniques for eliminating such redundant primitives do not fully consider the possibilities and rely on repeated evaluation of parts of the object's boundary, a process that is likely to be very slow. A technique that allows alternative eliminations to be examined is proposed and a potentially efficient, but geometrically approximate, method of implementation is outlined. >
Low-energy electron reflectivity from graphene: First-principles computations and approximate models

A computational method is developed whereby the reflectivity of low-energy electrons from a surface can be obtained from a first-principles solution of the electronic structure of the system. The method is applied to multilayer graphene. Two bands of reflectivity minima are found, one at 0–8 eV and the other at 14–22 eV above the vacuum level. For a free-standing slab with n layers of graphene, each band contains n� 1 zeroes in the reflectivity. Two additional image-potential type states form at the ends of the graphene slab, with energies just below the vacuum level, hence producing a total of 2n states. A tightbinding model is developed, with basis functions localized in the spaces between the graphene planes (and at the ends of the slab). The spectrum of states produced by the tight-binding model is found to be in good agreement with the zeros of reflectivity (i.e. transmission resonances) of the first-principles results. & 2013 Elsevier B.V. All rights reserved.
TinkerCell: modular CAD tool for synthetic biology.

Synthetic biology brings together concepts and techniques from engineering and biology. In this field, computer-aided design (CAD) is necessary in order to bridge the gap between computational modeling and biological data. Using a CAD application, it would be possible to construct models using available biological "parts" and directly generate the DNA sequence that represents the model, thus increasing the efficiency of design and construction of synthetic networks. An application named TinkerCell has been developed in order to serve as a CAD tool for synthetic biology. TinkerCell is a visual modeling tool that supports a hierarchy of biological parts. Each part in this hierarchy consists of a set of attributes that define the part, such as sequence or rate constants. Models that are constructed using these parts can be analyzed using various third-party C and Python programs that are hosted by TinkerCell via an extensive C and Python application programming interface (API). TinkerCell supports the notion of a module, which are networks with interfaces. Such modules can be connected to each other, forming larger modular networks. TinkerCell is a free and open-source project under the Berkeley Software Distribution license. Downloads, documentation, and tutorials are available at http://www.tinkercell.com . An ideal CAD application for engineering biological systems would provide features such as: building and simulating networks, analyzing robustness of networks, and searching databases for components that meet the design criteria. At the current state of synthetic biology, there are no established methods for measuring robustness or identifying components that fit a design. The same is true for databases of biological parts. TinkerCell's flexible modeling framework allows it to cope with changes in the field. Such changes may involve the way parts are characterized or the way synthetic networks are modeled and analyzed computationally. TinkerCell can readily accept third-party algorithms, allowing it to serve as a platform for testing different methods relevant to synthetic biology.
Intermediate Traces and Intermediate Learners: Evidence for the Use of Intermediate Structure during Sentence Processing in Second Language French.

This study reports on a sentence processing experiment in second language (L2) French that looks for evidence of trace reactivation at clause edge and in the canonical object position in indirect object cleft sentences with complex embedding and cyclic movement. Reaction time (RT) asymmetries were examined among low (n = 20) and high (n = 20) intermediate L2 learners and native speakers (n = 15) of French in a picture-classification-during-reading task. The results show that a subgroup of learners (13 from the low intermediate and 9 from the high intermediate group) as well as the native speakers produced response patterns consistent with reactivation—with the shortest RTs for antecedent-matching probes presented concurrently with the gap—at clause edge, followed by a second reactivation in the canonical object position. This finding suggests that L2 learners may be able to process real-time input in nativelike ways, despite arguments set forth in previous research of this kind.
THE BIG BANG? AN EVENTFUL YEAR IN WORKERS' COMPENSATION

Workers' compensation in the past two years has been dominated by events in California, which have been so fundamental as to merit the term big bang. Passage of Senate Bill 899 has led to a comprehensive program of reform in access to medical care, access to rehabilitation services, temporary and permanent disability, evidence-based management, dispute resolution, and system innovation. Two noteworthy developments thus arose: a new requirement for apportionment by cause in causation analysis, and the adoption of evidence-based criteria for impairment assessment, treatment guidelines, and, soon, utilization review. Elsewhere in the United States, changes were modest, but extensive legislative activity in Texas suggests that Texas will be next to make major changes. In Canada, the Workers' Compensation Board of British Columbia has adopted an ambitious strategic initiative, and there is a Canadawide movement to establish presumption for certain diseases in firefighters. Suggestions for future directions include an increased emphasis on prevention, integration of programs, worker participation, enhancing the expertise of health care professionals, evidence-based management, process evaluation, and opportunities for innovation.
Scanning and Traversing: Maintaining Data for Traversals in a Memory Hierarchy

We study the problem of maintaining a dynamic ordered set subject to insertions, deletions, and traversals of k consecutive elements. This problem is trivially solved on a RAM and on a simple two-level memory hierarchy. We explore this traversal problem on more realistic memory models: the cache-oblivious model, which applies to unknown and multi-level memory hierarchies, and sequential-access models, where sequential block transfers are less expensive than random block transfers.
Solutions to the output regulation problem of linear singular systems

In this paper, we revisit the output regulation problem for linear singular systems and identify an important case of the general regulation problem where the measurement output is identical to the vector to be regulated. We derive a necessary and sufficient condition for the regulation problem to be solvable via either full information feedback or error feedback. Then we show how full information feedback and error feedback controllers can be constructed explicitly.
A data-centered collaboration portal to support global carbon-flux analysis

Carbon-climate, like other environmental sciences, has been changing. Large-scale synthesis studies are becoming more common. These synthesis studies are often conducted by science teams that are geographically distributed and on data sets that are global in scale. A broad array of collaboration and data analytics tools are now available that could support these science teams. However, building tools that scientists actually use is difficult. Also, moving scientists from an informal collaboration structure to one mediated by technology often exposes inconsistencies in the understanding of the rules of engagement between collaborators. We have developed a scientific collaboration portal, called fluxdata.org, which serves the community of scientists providing and analyzing the global FLUXNET carbon-flux synthesis data set. The key things we learned or re-learned during our portal development include: minimize the barrier to entry, provide features on a just-in-time basis, development of requirements is an on-going process, provide incentives to change leaders and leverage the opportunity they represent, automate as much as possible, and you can only learn how to make it better if people depend on it enough to give you feedback. In addition, we also learned that splitting the portal roles between scientists and computer scientists improved user adoption and trust. The fluxdata.org portal has now been in operation for ∼2 years and has become central to the FLUXNET synthesis efforts. Published in 2010 by John Wiley & Sons, Ltd. This article is a U.S. Government work and is in the public domain in the U.S.A.
Micro-level product-market dynamics: Shared knowledge and its relationship to market development

This work draws on consumer and psychology research to explain sociocognitive aspects of product-market dynamics at a higher level of specificity than prior research. The authors extend the field’s understanding of market-shaping shared knowledge through a theory-informed discussion of how shared product knowledge comes to exist and how it changes as product markets develop. They define shared knowledge as the aspects of product representations that are common across the minds of market actors, making it possible for them to understand one another. The authors also discuss ways to track shared knowledge content that is expressed in market narratives. As the characteristics of shared knowledge are explained and linked to stages of product-market development, the authors develop a set of researchable propositions to guide future research. The theoretical arguments and propositions in this article complement extant marketing strategy research by integrating individual-level consumer theory with market evolution models.
On the spatial nature of the groundwater pumping externality

Most existing economic analyses of optimal groundwater management use single-cell aquifer models, which assume that an aquifer responds uniformly and instantly to groundwater pumping. In this paper, we develop an economic model of groundwater management that explicitly incorporates spatial dynamic groundwater flow equations. Calibration of our model to published economic studies of specific aquifers demonstrates that existing studies generally incorrectly estimate the magnitude of the groundwater pumping externality relative to spatially explicit models. In particular, for large aquifers with surface areas of thousands of square miles, the marginal pumping externality predicted by single-cell models may be orders of magnitude less than that predicted by a spatially explicit model, even at large distances from a pumping well. Conversely, for small aquifers with areas of a few hundred square miles or less, single-cell models reasonably approximate the pumping externality. Application of single-cell models to inappropriate settings may result in misleading policy implications due to understatement of the magnitude and spatial nature of the groundwater externality.
Towards Making Random Passwords Memorable: Leveraging Users' Cognitive Ability Through Multiple Cues

Given the choice, users produce passwords reflecting common strategies and patterns that ease recall but offer uncertain and often weak security. System-assigned passwords provide measurable security but suffer from poor memorability. To address this usability-security tension, we argue that systems should assign random passwords but also help with memorization and recall. We investigate the feasibility of this approach with CuedR, a novel cued-recognition authentication scheme that provides users with multiple cues (visual, verbal, and spatial) and lets them choose the cues that best fit their learning process for later recognition of system-assigned keywords. In our lab study, all 37 of our participants could log in within three attempts one week after registration (mean login time: 38.0 seconds). A pilot study on using multiple CuedR passwords also showed 100% recall within three attempts. Based on our results, we suggest appropriate applications for CuedR, such as financial and e-commerce accounts.
A model for motion coherence and transparency

A recent model for two-dimensional motion processing in MT has demonstrated that perceived direction can be accurately predicted by combining Fourier and non-Fourier component motion signals using a vector sum computation. The vector sum direction is computed by a neural network that weights Fourier and non-Fourier components by the cosine of the component direction relative to that of each pattern unit, after which competitive inhibition extracts the signals of the most active units. It is shown here that a minor modification of the connectivity in this network suffices to predict transitions from motion coherence to transparency under a wide range of circumstances. It is only necessary that the cosine weighting function and competitive inhibition be limited to directions within +/- 120 deg of each pattern unit's preferred direction. This network responds by signaling one pattern direction for coherent motion but two distinct directions for transparent motion. Based on this, neural networks with properties of MT and MST neurons can automatically signal motion coherence or transparency. In addition, the model accurately predicts motion repulsion under transparency conditions.
Effect of electron energy distribution function on power deposition and plasma density in an inductively coupled discharge at very low pressures

A self-consistent one-dimensional model was developed to study the effect of the electron energy distribution function (EEDF) on power deposition and plasma density profiles in a planar inductively coupled plasma (ICP) in the non-local regime (pressure ≤10 mTorr). The model consisted of three modules: (1) an EEDF module to compute the non-Maxwellian EEDF, (2) a non-local electron kinetics module to predict the non-local electron conductivity, radio frequency (RF) current, electric field and power deposition profiles in the non-uniform plasma, and (3) a heavy species transport module to solve for the ion density and velocity profiles as well as the metastable density. Results using the non-Maxwellian EEDF model were compared with predictions using a Maxwellian EEDF, under otherwise identical conditions. The RF electric field, current and power deposition profiles were different, especially at 1 mTorr, for which the electron effective mean-free-path was larger than the skin depth. The plasma density predicted by the Maxwellian EEDF was up to 93% larger for the conditions examined. Thus, the non-Maxwellian EEDF must be accounted for in modelling ICPs at very low pressures.
Electrical Resistivity Surface for FeO-Fe2O3-P2O5 Glasses

The dc electrical properties and microstructure of x(FeO-Fe2O3)-(100-x)P2O5 glasses were investigated up to a maximum of x = 75 mol %. Results indicate that, in general, the minimum resistivity of the glass does not occur at equal Fe(2+) and Fe(3+) concentrations, although for the special case where x = 55 mol % the minimum does occur at Fe(2+)/Fe total = 0.5, as reported by other investigators. Evidence presented shows that the position of the minimum resistivity is a function of total iron content. The minimum shifts to glasses richer in Fe(2+) at higher total iron concentrations.
Derivatives Pricing on Integrated Diffusion Processes: A General Perturbation Approach

Many derivatives products are directly or indirectly associated with integrated diffusion processes. We develop a general perturbation method to price those derivatives. We show that for any positive diffusion process, the hitting time of its integrated process is approximately normally distributed when the diffusion coefficient is small. This result of approximate normality enables us to reduce many derivative pricing problems to simple expectations. We illustrate the generality and accuracy of this probabilistic approach with several examples in the Heston model. Major advantages of the proposed technique include extremely fast computational speed, ease of implementation, and analytic tractability. © 2014 Wiley Periodicals, Inc. Jrl Fut Mark 35:582–595, 2015
Superconductivity in tight-binding approximation

Abstract An interpretation of Barisic's relation for transition elements between the d-electron contribution to the cohesive energy and the local atomic parameter η is presented. We extend this relation to a lattice with more than one atom per unit cell in the tight-binding approximation of rigid ions. It is conjectured that Barisic's relation is correct to first order approximation for transition metal alloys, provided the phonon induced d-d coupling is the dominant mechanism for superconductivity.
Proportional Mens Rea

This Essay makes the case for "proportional mens rea," a proportionality-based approach to mens rea selection. Proportional mens rea would provide proportionality safeguards that are otherwise entirely lacking in substantive criminal law and,as a practical matter, unavailable in constitutional law. Creating implied mens rea requirements, where necessary to ensure proportional punishment, is not a judicial usurpation of a legislative function. Rather, it is to take seriously the role that courts play, under both constitutional and substantive criminal law, to ensure that punishment "fits" the crime. Moreover, proportional mens rea would represent a needed counterweight to prosecutorial behavior whereas current doctrine does not. Given that federal prosecutors do not seek to charge morally blameless people, mens rea doctrine aimed only at protecting moral blamelessness from punishment will largely be redundant of prosecutorial discretion. Proportionality of punishment, however, is a concern that federal prosecutors -- bound by longstanding Executive Branch mandates to seek the maximum supportable penalty in every case and oppose lenient exercises of judicial sentencing discretion--routinely ignore. Judicial mens rea selection, therefore, has a substant substantial contribution to make to the achievement of proportionality of punishment.
Further Evidence on Equity Market Contagion: the FSLIC's Solvency and the Liquidity Crisis of Financial Corporation of America

Whether pure contagion is more likely to occur when a federal deposit insurer is severely undercapitalized is an unanswered question. This paper provides evidence on this issue by examining the stock market reaction of savings and loans (S&Ls) to the crisis of Financial Corporation of America (FCA) in 1984, when the Federal Savings and Loan Insurance Corporation was fiscally unsound. Consistent with a contingent insurance guarantee hypothesis, the results show large, significant negative abnormal returns (ARs) for a portfolio of high insured deposit S&Ls during FCA's crisis.
Democracy, Diversification and Growth Reversals*

There exists convincing evidence that democratic countries are less volatile. This conclusion is usually reached with respect to volatility as measured by the standard deviation of annual growth rates of per capita GDP which includes both low and high frequency fluctuations. However, recently several studies have documented that significant changes in trend-growth, such as growth accelerations that last a decade or similar periods of negative growth, are quite common. In this paper we ask whether democracy also has a stabilizing effect on trend-volatility, i.e. whether more democratic countries experience fewer and milder swings of trend-growth. We find a common phenomenon medium term reversals of growth, that is periods of exceptionally high growth are, on average, followed by periods of exceptionally low growth, and vice versa. The propensity to experience large swings of trend growth is not uniform across countries-less democratic countries are more susceptible to it. When compared with factors commonly associated with volatility such as measures of quality of institutions, macroeconomic policies and financial development, we find that democracy is the most robust predictor of a country's propensity for growth reversals. We construct a model in which non-democracies have high barriers of entry for new firms. This leads to less sectoral diversification: fewer sectors are operated but more resources are channeled to each. In an uncertain environment this leads to infrequent but large growth accelerations when one of the few sectors operated is successful. However, these accelerations are followed by large declines when fortunes change in favor of the missing sectors. We present empirical evidence that confirms the positive relationship between democracy and industrial diversification.
Market-Making Behavior in Futures Markets

This paper examines voluntary market-making behavior, namely scalping, in futures markets. Specifically, this paper studies what factors determine scalpers' entry and exit, and how scalping affects market liquidity and price volatility. The data used for the analysis are time-stamped electronic transaction data marked with traders' identities from the Dalian Futures Exchanges in China. The contributions of this paper are: (1) to give detailed analysis of scalping behavior and its impact on market liquidity; (2) to develop new econometric tools for analyzing time-series count data; (3) to propose a new measure of liquidity.
Whether or not to open Pandora's box

I study a single-agent sequential search problem as in Weitzman (1979). Contrary to Weitzman, conditional on stopping, the agent may take any uninspected box without first inspecting its contents. This introduces a new trade-off. By taking a box without inspection, the agent saves on its inspection costs. However, by inspecting it, he may discover that its contents are lower than he anticipated. I identify sufficient conditions on the parameters of the environment under which I characterize the optimal policy. Both the order in which boxes are inspected and the stopping rule may differ from that in Weitzman's model. Moreover, I provide additional results that partially characterize the optimal policy when these conditions fail.
X-CAPM: An Extrapolative Capital Asset Pricing Model

Abstract Survey evidence suggests that many investors form beliefs about future stock market returns by extrapolating past returns. Such beliefs are hard to reconcile with existing models of the aggregate stock market. We study a consumption-based asset pricing model in which some investors form beliefs about future price changes in the stock market by extrapolating past price changes, while other investors hold fully rational beliefs. We find that the model captures many features of actual prices and returns; importantly, however, it is also consistent with the survey evidence on investor expectations.
Density functional calculations of nanoscale conductance

Density functional calculations for the electronic conductance of single molecules are now common. We examine the methodology from a rigorous point of view, discussing where it can be expected to work, and where it should fail. When molecules are weakly coupled to leads, local and gradient-corrected approximations fail, as the Kohn–Sham levels are misaligned. In the weak bias regime, exchange–correlation corrections to the current are missed by the standard methodology. For finite bias, a new methodology for performing calculations can be rigorously derived using an extension of time-dependent current density functional theory from the Schrodinger equation to a master equation.
Solar surveillance zone population strategies with picosatellites using halo and distant retrograde orbits

Abstract Solar surveillance missions that provide ample warning time of impending solar storms to satellite users in earth orbit are naturally designed to allow the weather forecasting spacecraft to wander as far away from the earth as possible, in the direction of the sun. Vehicles positioned on the L 1 halo orbits do not provide more than an hour of warning time due to the fact that the L 1 equilibrium point of the sun–earth system is located at some 1.5 million km from the earth. In order to increase this warning time by a factor of two or more, use is made in this paper of distant retrograde orbits which allow compact sensorcraft to remain in the vicinity of the earth but at substantially larger distances from it than the L 1 point. However, the sensorcraft transit periodically and only for a limited time inside the surveillance zone centered on the sun–earth axis, such that a certain number of such sensorcraft is needed for continuous surveillance capability. An alternative scheme produces a finite number of passes through the surveillance zone with some transits reaching much further out toward the sun, over several years. Another scheme utilizes a series of miniature probes released from a multi-probe carrier vehicle from a parking halo orbit, to travel on that halo orbit invariant unstable manifold in successive single passes through the surveillance zone, requiring continuing replenishment. This paper shows several sensorcraft and sensor probes release strategies and their associated trajectories for both the distant retrograde orbit and the halo orbit cases. It also provides an estimate of the minimum number of probes needed for continuous coverage for a given time span.
Jet energy calibration at the LHC

Jets are one of the most prominent physics signatures of high energy proton–proton (p–p) collisions at the Large Hadron Collider (LHC). They are key physics objects for precision measurements and searches for new phenomena. This review provides an overview of the reconstruction and calibration of jets at the LHC during its first Run. ATLAS and CMS developed different approaches for the reconstruction of jets, but use similar methods for the energy calibration. ATLAS reconstructs jets utilizing input signals from their calorimeters and use charged particle tracks to refine their energy measurement and suppress the effects of multiple p–p interactions (pileup). CMS, instead, combines calorimeter and tracking information to build jets from particle flow objects. Jets are calibrated using Monte Carlo (MC) simulations and a residual in situ calibration derived from collision data is applied to correct for the differences in jet response between data and Monte Carlo. Large samples of dijet, Z+jets, and γ+events at the LHC allowed the calibration of jets with high precision, leading to very small systematic uncertainties. Both ATLAS and CMS achieved a jet energy calibration uncertainty of about 1% in the central detector region and for jets with transverse momentum pT > 100GeV. At low jet pT, the jet energy calibration uncertainty is less than 4%, with dominant contributions from pileup, differences in energy scale between quark and gluon jets, and jet flavor composition.
The Impact of Historical and Regional Linkages on Free Trade in the Americas: A Gravity Model Analysis Across Sectors

This paper estimates the impact of regional linkages (i.e. regional trading agreements) and historical linkages (i.e. neo-colonial trade ties) on trade pattern in the Western Hemisphere using the gravity model of international trade. The estimation is made at the aggregate trade level as well as on the disaggregated level by using trade data corresponding to food products and manufactured goods respectively. The evidence suggests that significant distortions of trade patterns due to regional and historical linkages exist. It seems that smaller economies are more receptive to the effects of regionalism than larger ones and that the food sector is more affected by distortions than the manufactured goods sector.
Early-stage software design for usability

In spite of the goodwill and best efforts of software engineers and usability professionals, systems continue to be built and released with glaring usability flaws that are costly and difficult to fix after the system has been designed and/or built. Although user interface (UI) designers, be they usability or design experts, communicate usability requirements to software development teams, seemingly obvious usability features often fail to be implemented as expected. If, as seems likely, software developers intend to implement what UI designers specify and simply do not know how to interpret the architectural ramifications of usability requirements, then Usability-Supporting Architectural Patterns (USAPs) will help to bridge the gap between UI designers and software engineers to produce software architecture solutions that successfully address usability requirements. USAPs will achieve this goal by embedding usability concepts in templates that can be used procedurally to guide software engineers' thinking and reduce memory load during the complex task of software architecture design.
Possible futures of electroweak precision: ILC, FCC-ee, and CEPC

The future of high-precision electroweak physics lies in e + e − collider measurements of properties of the Z boson, the W boson, the Higgs boson, and the top quark. We estimate the expected performance of three possible future colliders: the ILC, FCC-ee (formerly known as TLEP), and CEPC. In particular, we present the first estimates of the possible reach of CEPC, China’s proposed Circular Electron-Positron Collider, for the oblique parameters S and T and for seven-parameter fits of Higgs couplings. These results allow the physics potential for CEPC to be compared with that of the ILC and FCC-ee. We also show how the constraints on S and T would evolve as the uncertainties on each of the most important input measurements change separately. This clarifies the basic physics goals for future colliders. To improve on the current precision, the highest priorities are improving the uncertainties on m W and sin2 θ eff . At the same time, improved measurements of the top mass, the Z mass, the running of α, and the Z width will offer further improvement which will determine the ultimate reach. Each of the possible future colliders we consider has strong prospects for probing TeV-scale electroweak physics.
Three bimodules for Mansfield's imprimitivity theorem

For a maximal coaction δ of a discrete group G on a C*-algebra A and a normal subgroup N of G, there are at least three natural A × G ×δ| N - A ×δ|1 G/N imprimitivity bimodules: Mansfield's bimodule ; the bimodule assembled by Ng from Green's imprimitivity bimodule and Katayama duality; and the bimodule assembled from and the crossed-product Mansfield bimodule . We show that all three of these are isomorphic, so that the corresponding inducing maps on representations are identical. This can be interpreted as saying that Mansfield and Green induction are inverses of one another ‘modulo Katayama duality’. These results pass to twisted coactions; dual results starting with an action are also given.
Generalized Quantity Competition for Multiple Products and Loss of Efficiency

We study a generalized model of quantity (Cournot) oligopolistic competition. The impact of competition on social surplus and firms' profit is analyzed. Firms produce multiple differentiated products and face production constraints. We compare the social surplus produced by competing firms and by colluding firms with the maximum achievable total surplus in the market. Similarly, we quantify the loss of profit that firms incur by competing instead of colluding. Our goal is to understand how the presence of competition affects the firms and society as a whole, but also to determine what are the key drivers of the inefficiencies that arise due to competition.
Calculation of transonic internal flows using an efficient high-resolution upwind scheme

A new efficient upwind scheme based on the concept of convective upwind and split pressure is developed. The upwinding of the convective term and the pressure split are consistent with their characteristic directions. The scheme has low diffusion to resolve accurately wall boundary layers and is able to capture crisp shock waves and exact contact discontinuities. The accuracy of the scheme is compared with other popularly used schemes including the Roe scheme, the Liou's latest advection upstream splitting method scheme (AUSM + ), the Van Leer scheme, and the Van Leer-Hanel scheme. The new scheme is tested for the one-dimensional Sod shock tube problem, one-dimensional slowly moving contact surface, supersonic flat plate laminar boundary layer, a transonic nozzle with oblique shock waves and reflections that do not align with the mesh lines, and a transonic inlet diffuser with shock wave/turbulent boundary-layer interaction
An X-Ray Survey of Galaxies in Pairs

Results are reported from the first survey of X-ray emission from galaxies in pairs. The sample consists of 52 pairs of galaxies from the Catalog of Paired Galaxies whose coordinates overlap the ROSAT Position Sensitive Proportional Counter pointed observations. The mean observed loglX for early-type pairs is 41.35±0.21, while the mean loglX predicted using the lX-lb relationship for isolated early-type galaxies is 42.10±0.19. With 95% confidence, the galaxies in pairs are underluminous in the X-ray, compared with isolated galaxies, for the same lb. A significant fraction of the mixed pair sample also appears similarly underluminous. A spatial analysis shows that the X-ray emission from pairs of both types typically has an extent of ~10-50 kpc, much smaller than the group intergalactic medium, and thus likely originates from the galaxies. CPG 564, the most X-ray luminous early-type pair, 4.7×1042 ergs s-1, is an exception. The extent of its X-ray emission, greater than 169 kpc, and HWHM, ~80 kpc, is comparable to that expected from an intergalactic medium. The sample shows only a weak correlation, ~81% confidence, between lX and lb, presumably due to variations in gas content within the galaxies. No correlation between lX and the pair velocity difference (Δv), separation (Δr), or far-infrared luminosity (lfir) is found, although the detection rate is low, 22%.