Miracle-dz/UniFAR-FTUs huggingface dataset:
Preliminary and Incomplete

Theory suggests the financial decisions of durable goods makers can impose externalities on their consumers. Namely, the consumption stream that durable goods provide frequently depends on services provided by the manufacturer itself (e.g., warranties, spare parts availability, maintenance and upgrades). Manufacturer bankruptcy, or even the possibility thereof, threatens this service provision and as a result can substantially reduce the value of its products to their current owners. We test whether this hypothesis holds in one of the largest durable goods markets, automobiles. We use data on prices of millions of used cars sold at wholesale auctions around the U.S. during 2006-8. We find that an increase in an auto manufacturer’s financial distress (as measured by an increase in its CDS spread) does result in a contemporaneous drop in the prices of its cars at auction, controlling for a host of other influences on price. The estimated effects are statistically and economically significant. Furthermore, cars with longer expected service lives (those within manufacturer warranty, having lower mileage, or in better condition) see larger price declines than those with shorter remaining lives. These patterns do not seem to be driven solely by reduced demand from auto dealers affiliated with the troubled manufacturers. Our estimates also imply a potentially large indirect cost of financial distress on car manufacturers. ∗ Preliminary and incomplete. Contact information: Hortaçsu: Department of Economics, University of Chicago, 1126 E. 59 St., Chicago, IL 60637. ; Matvos and Syverson: University of Chicago Booth School of Business, 5807 S. Woodlawn Ave., Chicago, IL 60637; Venkataraman: Goizueta Business School, Emory University, 1300 Clifton Road NE, Atlanta, Georgia 30322.
HIGH FREQUENCY IDENTIFICATION OF MONETARY NON-NEUTRALITY

We present estimates of monetary non-neutrality based on evidence from high-frequency responses of nominal and real interest rates. Our identifying assumption is that unexpected changes in interest rates in a 30-minute window surrounding scheduled Federal Reserve announcements arises from news about monetary policy. At these times, nominal and real interest rates respond roughly one-for-one, several years out into the term structure, while the response of expected inflation is small. We use this evidence to estimate key parameters of a workhorse New Keynesian model. The implied degree of monetary non-neutrality is large. Moreover, we find evidence of a "Fed information effect": FOMC announcements affect expectations not only about the evolution of monetary policy but also about future economic fundamentals.
DISSIPATIVE PARTICLE DYNAMICS SIMULATION OF MULTIPLE DEFORMABLE RED BLOOD CELLS IN A VESSEL

The blood flow properties in microvessels were examined through simulating the dynamics of deform- able red blood cells suspended in plasma using dissipative particle dynamics. The cell membrane was considered as a spring-based triangulated network and the intercellular interaction was modeled by a Morse potential function. The cell distribution in the cross section indicated that red blood cells migrate away from the wall to the tube center, resulting in a cell-free layer near the wall and blunt velocity profile. The findings also showed that the bluntness of velocity profile increases with increasing hema- tocrit. In addition, the Fahraeus and Fahraeus–Lindqvist effects were captured through investigating the effects of tube diameter and hematocrit on the discharge hematocrit and relative apparent viscosity. It appears that this flow model can capture the blood flow behaviors under physiological and pathological conditions.
College Attrition and the Dynamics of Information Revelation

This paper investigates the role played by informational frictions in college and the workplace. We estimate a dynamic structural model of schooling and work decisions, where individuals have imperfect information about their schooling ability and labor market productivity. We take into account the heterogeneity in schooling investments by distinguishing between two- and four-year colleges, graduate school, as well as science and non-science majors for four-year colleges. Individuals may also choose whether to work full-time, part-time, or not at all. A key feature of our approach is to account for correlated learning through college grades and wages, whereby individuals may leave or re-enter college as a result of the arrival of new information on their ability and productivity. Our findings indicate that the elimination of informational frictions would increase the college graduation rate by 9 percentage points, and would increase the college wage premium by 32.7 percentage points through increased sorting on ability.
A Century of Capital Structure : The Leveraging of Corporate America *

Unregulated U.S. corporations dramatically increased their debt usage over the past century. Aggregate leverage – low and stable before 1945 – more than tripled between 1945 and 1970 from 11% to 35%, eventually reaching 47% by the early 1990s. The median firm in 1946 had no debt, but by 1970 had a leverage ratio of 31%. This increase occurred in all unregulated industries and affected firms of all sizes. Changing firm characteristics are unable to account for this increase. Rather, changes in government borrowing, macroeconomic uncertainty, and financial sector development play a more prominent role. Despite this increase among regulated firms, a combination of stable debt usage among regulated firms and a decrease in the fraction of aggregate assets held by regulated firms over this period resulted in a relatively stable economy-wide leverage ratio during the 1900s.
Track Layouts of Graphs

A \emph{$(k,t)$-track layout} of a graph $G$ consists of a (proper) vertex $t$-colouring of $G$, a total order of each vertex colour class, and a (non-proper) edge $k$-colouring such that between each pair of colour classes no two monochromatic edges cross. This structure has recently arisen in the study of three-dimensional graph drawings. This paper presents the beginnings of a theory of track layouts. First we determine the maximum number of edges in a $(k,t)$-track layout, and show how to colour the edges given fixed linear orderings of the vertex colour classes. We then describe methods for the manipulation of track layouts. For example, we show how to decrease the number of edge colours in a track layout at the expense of increasing the number of tracks, and vice versa. We then study the relationship between track layouts and other models of graph layout, namely stack and queue layouts, and geometric thickness. One of our principle results is that the queue-number and track-number of a graph are tied, in the sense that one is bounded by a function of the other. As corollaries we prove that acyclic chromatic number is bounded by both queue-number and stack-number. Finally we consider track layouts of planar graphs. While it is an open problem whether planar graphs have bounded track-number, we prove bounds on the track-number of outerplanar graphs, and give the best known lower bound on the track-number of planar graphs.
Localized and adaptive soft sensor based on an extreme learning machine with automated self‐correction strategies

A novel, nonlinear soft sensor based on a localized, adaptive single‐layer feedforward neural network with random hidden layer weights, also called an extreme learning machine, combined with the recursive partial least squares algorithm to update the linear output layer weights, is explored. The soft sensor is highly adaptive with minimal operator input, and automated mechanisms are included to self‐correct numerous aspects of the underlying model. For instance, mechanisms are put in place to automatically select an optimized local model region describing the current process dynamics from the historical data when the current prediction error reaches an adaptively computed threshold. Additionally, the new soft sensor simultaneously employs an ensemble of models with diverse recursive partial least squares forgetting factors with automated and adaptive reweighting of the models in the ensemble, thus enabling real‐time model memory adjustment. The validity of the method is shown by comparison with numerous other soft sensor methods for the prediction of the activity of a polymerization catalyst.
CERTIFAI: Counterfactual Explanations for Robustness, Transparency, Interpretability, and Fairness of Artificial Intelligence models

As artificial intelligence plays an increasingly important role in our society, there are ethical and moral obligations for both businesses and researchers to ensure that their machine learning models are designed, deployed, and maintained responsibly. These models need to be rigorously audited for fairness, robustness, transparency, and interpretability. A variety of methods have been developed that focus on these issues in isolation, however, managing these methods in conjunction with model development can be cumbersome and timeconsuming. In this paper, we introduce a unified and model-agnostic approach to address these issues: Counterfactual Explanations for Robustness, Transparency, Interpretability, and Fairness of Artificial Intelligence models (CERTIFAI). Unlike previous methods in this domain, CERTIFAI is a general tool that can be applied to any black-box model and any type of input data. Given a model and an input instance, CERTIFAI uses a custom genetic algorithm to generate counterfactuals: instances close to the input that change the prediction of the model. We demonstrate how these counterfactuals can be used to examine issues of robustness, interpretability, transparency, and fairness. Additionally, we introduce CERScore, the first black-box model robustness score that performs comparably to methods that have access to model internals.
Quantile regression: applications and current research areas

Summary. Quantile regression offers a more complete statistical model than mean regression and now has widespread applications. Consequently, we provide a review of this technique. We begin with an introduction to and motivation for quantile regression. We then discuss some typical application areas. Next we outline various approaches to estimation. We finish by briefly summarizing some recent research areas.
The Hyperbolic Consumption Model: Calibration, Simulation, and Empirical Evaluation

O ur preferences for the long run tend to conflict with our short-run behavior. When planning for the long run, we intend to meet our deadlines, exercise regularly, and eat healthfully. But in the short run, we have little interest in revising manuscripts, jogging on the StairMaster, and skipping the chocolate soufflé a ` la mode. Delay of gratification is a nice long-term goal, but instant gratification is disconcertingly tempting. This gap between long-run intentions and short-run actions is apparent across a wide range of behaviors, including saving choices. A 1997 survey found that 76 percent of respondents believe they should be saving more for retirement. Looking only at respondents who believed they were at an age where " you should be seriously saving already, " the survey found that 55 percent reported being " Behind " in their savings and only 6 percent reported being " Ahead " (Farkas and Johnson, 1997). The report on the survey concluded: " [T]he gaps between people's attitudes , intentions, and behavior are troubling and threaten increased insecurity and dissatisfaction for people when they retire. Americans are simply not doing what logic—and their own reasoning—suggests they should be doing. " A 1993 Luntz Webber/Merrill Lynch survey found similar answers when baby boomers were asked: " What percentage of your annual household income do you think you should save for retirement? " and " What percentage of your annual
New aspects of particle acceleration in collapsing magnetic traps

Collapsing magnetic traps (CMTs) have been suggested as one of the mechanisms that could contribute to particle energisation in solar flares. The basic idea behind CMTs is that charged particles will be trapped on the magnetic field lines below the reconnection region of a flare. This thesis discusses a number of important new aspects in particle energisation processes in CMTs, based on the model by Giuliani et al. (2005). In particular, we extend previous studies of particle acceleration in this CMT model to the relativistic regime and compare our results obtained using relativistic guiding centre theory with results obtained using the non-relativistic guiding centre theory. The similarities and differences found are discussed. We then present a detailed study of the question, what leads to the trapping or escape of particle orbits from CMTs. The answer to this question is investigated by using results from the non-relativistic orbit calculations with guiding centre theory and a number of simple models for particle energy gain in CMTs. We find that there is a critical pitch angle dividing trapped particle orbits from the escaping particle orbits and that this critical pitch angle does not coincide with the initial loss cone angle. Furthermore, we also present a calculation of the time evolution of an anisotropic pressure tensor and of the plasma density under the assumptions that they evolve in line with our kinematic MHD CMT model and that the pressure tensor satisfies the double-adiabatic Chew-GoldburgerLow (CGL) theory. Finally, we make a first step to introduce Coulomb scattering by a Maxwellian background plasma into our guiding centre equations by changing them into a set of stochastic differential equations. We study the influence of a static background plasma onto selected particle orbits by pitch angle scattering and energy losses, and look at its effect on the particle energy and the trapping conditions.
Do Patent Pools Encourage Innovation? Evidence from the 19th-Century Sewing Machine Industry

Members of a patent pool agree to use a set of patents as if they were jointly owned by all members and license them as a package to other firms. Regulators favor pools as a means to encourage innovation: Pools are expected to reduce litigation risks for their members and lower license fees and transactions costs for other firms. This paper uses the example of the first patent pool in U.S. history, the Sewing Machine Combination (1856-1877) to perform the first empirical test of the effects of a patent pool on innovation. Contrary to theoretical predictions, the sewing machine pool appears to have discouraged patenting and innovation, in particular for the members of the pool. Data on stitches per minute, as an objectively quantifiable measure of innovation, confirm these findings. Innovation for both members and outside firms slowed as soon as the pool had been established and resumed only after it had dissolved.
There Is No Free Lunch In Adversarial Robustness (But There Are Unexpected Benefits)

We provide a new understanding of the fundamental nature of adversarially robust classiﬁers and how they differ from standard models. In particular, we show that there provably exists a trade-off between the standard accuracy of a model and its robustness to adversarial perturbations. We demonstrate an intriguing phenomenon at the root of this tension: a certain dichotomy between “robust” and “non-robust” features. We show that while robustness comes at a price, it also has some surprising beneﬁts. Robust models turn out to have interpretable gradients and feature representations that align unusually well with salient data characteristics. In fact, they yield striking feature interpolations that have thus far been possible to obtain only using generative models such as GANs.
On the Helical Structure of the Ekman Boundary Layer

The dynamic equations of a neutrally stratified boundary layer and formulas of Monin's semiem- pirical turbulence theory generalized with allowance for the helicity of the velocity field are used to calculate the mean wind velocity and one-point pair moments of velocity fluctuations in the Ekman boundary layer under steady-state conditions. Developing in the Ekman layer in a natural way, turbulent helicity is shown to reduce the turn angle of the mean wind with height as compared to classical theory and to increase the depth of the boundary layer.
C ENTRE FOR A PPLIED M ACROECONOMIC A NALYSIS S ETTING : D EVELOPING S OME E ARLY I NSIGHTS OF J OHN M AYNARD K EYNES AND J OAN R OBINSON

This paper argues that the theory of wage and price setting in macroeconomics should be broadened to include insights from behavioural economics, in particular prospect theory and loss aversion. The paper shows how broader microeconomic foundations can explain the main features of a realistic Phillips curve, which are the concurrence of a steep SRPC at low unemployment, a flat SRPC at high unemployment and speed-limit effects. The resulting macroeconomic model has the benefits of consistency with important properties of natural rate models, especially a crucial role for inflation expectations and, in determining the economy’s macroeconomic potential, for supply factors, plus the benefit of consistency with the standard IS/LM model. The paper also shows that the behavioural aspects of these broader microeconomic foundations were alluded to by Keynes and Robinson in 1936 when macroeconomics was created.
Atmospheric correction of imaging spectroscopy data using shadow-based quantification of aerosol scattering effects

The atmospheric correction accuracy strongly depends on the correct estimate of the aerosol scattering effects. This paper shows first results of a new aerosol optical thickness inversion method and its use for improved atmospheric correction of high spatial resolution imaging spectroscopy data. The approach uses small scale shadow pixels for the determination of the atmospheric scattering by inverting the shadow correction within the ATCOR® atmospheric compensation method. The detection of shadow pixels is done by a blue to red ratio which is further adjusted by the near infrared band in order to take the vegetation bias into account. On high resolution instruments with resolutions below 5 m, a decent quantity of shaded pixels can be found by this method in a reliable way. Using this shadow mask, the aerosol inversion is done. The aerosol contents are varied in a way that retrieves a correction of shaded areas to a brightness comparable to non-shaded areas, leading to the best fitting aerosol amount. The shadow based aerosol optical thickness (SHAOT) method is tested on APEX and HYSPEX airborne imaging spectroscopy data. It can be shown that the atmospheric compensation using the such derived aerosol contents are significantly improved in comparison to standard correction techniques.
ISO spectroscopy of compact HII regions in the Galaxy - II. Ionization and elemental abundances

Based on the ISO spectral catalogue of compact H ii regions by Peeters et al. (2002), we present a rst analysis of the hydrogen recombination and atomic ne-structure lines originated in the ionized gas. The sample consists of 34 H ii regions located at galactocentric distances between RGal = 0 and 15 kpc. The SWS H i recombination lines between 2 and 8 m are used to estimate the extinction law at these wavelengths for 14 H ii regions. An extinction in the K band between 0 and 3 mag has been derived. The ne-structure lines of N, O, Ne, S and Ar are detected in most of the sources. Most of these elements are observed in two dierent ionization stages probing a range in ionization potential up to 41 eV. The ISO data, by itself or combined with radio data taken from the literature, is used to derive the elemental abundances relative to hydrogen. The present data thus allow us to describe for each source its elemental abundance, its state of ionization and to constrain the properties of the ionizing star(s). The main results of this study are as follows. The ionization ratios Ar ++ /Ar + ,N ++ /N + ,S +3 /S ++ and Ne ++ /Ne + , which measure the degree of ionization and to rst order, the hardness of the stellar radiation, seem to increase with RGal. These ionization ratios correlate well with each other, implying that the spectral hardening aects equally the full range of ionizing energies. A Galactocentric gradient of N/O (log N= O= 0:056 0:009 dex kpc 1 ) is observed in the sense of a decreasing abundance ratio with RGal in agreement with previous studies. Abundance gradients for neon and argon are derived of the form log Ne= H= 0:039 0:007 dex kpc 1 and log Ar= H= 0:045 0:011 dex kpc 1 . These elemental gradients could be enlarged by the existing Galactic Te gradient. Adopting a Te gradient of approximately 330 K kpc 1 , the slopes in the Ne/H and Ar/H gradients become 0:06 and 0:07 dex kpc 1 , respectively. Lower limits for
The Fine Page

Much of the dogma regarding systemic corticosteroids (CS) is derived either from empiricism and or personal bias. While rational treatment regimens based on physiologic and pharmacologic properties of these drugs have been proposed, viz. single daily a,m. dose or alternate-day dosage,^'^ they are often ignored either for the sake of convenience or because of honest misconceptions based on anecdotal experiences. There are pitifully few well controlled studies using systemic CS in the treatment of patients with inflammatory diseases that involve large numbers of patients followed for prolonged periods of time. In a recent publication Kyle and Hazleman reported their experience treating patients with polymyalgia rheumatica and temporal arteritis with systemic CS, They studied two groups of patients, one followed prospectively and one retrospectively. The incidence of side effects in both groups were similar, about one third rising to two thirds when minor changes (skin, weight gain) were included. The follow-up period was relatively short (mean, 18 months) in the prospective patients, thus the reason for including the retrospective group,^ In the prospective arm 35 patients were followed at least 18 months. Side effects were specifically related to the initial daily dose, 30 mg or more of prednisolone, and to the cumulative dose, which was 70% higher in those patients who developed side effects. The mean daily dose was slightly higher (11 mg vs. 10 mg) in those patients who developed side effects in this group. In the retrospective group 74 patients were followed for a mean period of 17 months. Side effects were related both to the maximum daily dose of
Experimental and numerical study on transient air–water mixing flows in viscoelastic pipes

ABSTRACT Air–water mixing flows are commonly formed in pressurized water supply pipes due to dissolved air from the water under low pressure conditions, and air injected through system controls and associated valves and pumps. This paper investigates transient behaviours of air–water mixing flows in viscoelastic pipes through laboratory experimental tests, numerical modelling and theoretical analysis. Two numerical schemes – the discrete vaporous cavity model (DVCM) and the discrete gas cavity model (DGCM), which are firstly calibrated and validated by the experimental data gained in this study, are adopted for comparative study for their validity and accuracy for modelling transient air–water mixing flows in viscoelastic pipes. With the validated model, the results of systematic analysis show that the effect of pipe-wall viscoelasticity on transient amplitude damping decreases with the increase of air content, and the frequency shifting rate of viscoelastic effect is negligible in comparison with that of air content.