Some identities on derangement and degenerate derangement polynomials

In combinatorics, a derangement is a permutation that has no fixed points. The number of derangements of an n-element set is called the n-th derangement number. In this paper, as natural companions to derangement numbers and degenerate versions of the companions we introduce derangement polynomials and degenerate derangement polynomials. We give some of their properties, recurrence relations and identities for those polynomials which are related to some special numbers and polynomials.Comment: 12 page

Does Mandatory IFRS Adoption Impact Audit Fees?: Theory and Evidence

Concurrent sessions 4C - Auditing / AuditThis study examines the impact of International Financial Reporting Standards (IFRS) adoption on audit fee. We first build an analytical audit fee model to analyze the impact on audit fee of the change in both audit complexity and financial reporting quality brought about by IFRS adoption. We then develop our hypotheses based on the model’s predictions, and test the hypotheses using audit fee data from European Union countries that mandated IFRS adoption in 2005. We find that mandatory IFRS adoption has led to an increase in audit fees. We also find that the IFRS-related audit fee premium increases with the increase in audit complexity brought about by IFRS adoption, and decreases with the improvement in financial reporting quality arising from IFRS adoption. Finally, we find some evidence that the IFRS-related audit fee premium is lower in countries with strong legal regimes. Our results are robust to a variety of sensitivity checks.published_or_final_versio

ATHENA: Mathematical Reasoning with Thought Expansion

Solving math word problems depends on how to articulate the problems, the lens through which models view human linguistic expressions. Real-world settings count on such a method even more due to the diverse practices of the same mathematical operations. Earlier works constrain available thinking processes by limited prediction strategies without considering their significance in acquiring mathematical knowledge. We introduce Attention-based THought Expansion Network Architecture (ATHENA) to tackle the challenges of real-world practices by mimicking human thought expansion mechanisms in the form of neural network propagation. A thought expansion recurrently generates the candidates carrying the thoughts of possible math expressions driven from the previous step and yields reasonable thoughts by selecting the valid pathways to the goal. Our experiments show that ATHENA achieves a new state-of-the-art stage toward the ideal model that is compelling in variant questions even when the informativeness in training examples is restricted.Comment: EMNLP 2023 (main); 13 pages, 5 figures, 8 table

Preparation of titanium dioxide (TiO<inf>2</inf>) from sludge produced by titanium tetrachloride (TiCl<inf>4</inf>) flocculation of wastewater

Sludge disposal is one of the most costly and environmentally problematic challenges of modern wastewater treatment worldwide. In this study, a new process was developed, which has a significant potential for lower cost of waste disposal, protection of the environment and public health, and yield of economically useful byproducts. Titanium oxide (TiO2), which is the most widely used metal oxide, was produced from the wastewater sludge generated by the flocculation of secondary wastewater with titanium tetrachloride (TiCl4). Detailed analyses were conducted to compare TiCl 4, ferric chloride (FeCl3), and aluminum sulfate (Al 2(SO4)3) flocculation. Removal of organic matter and different molecular sizes by Ti-salt flocculation was similar to that of the most widely used Fe- and Al-salt flocculation. The mean size of Ti-, Fe-, and Al-salt flocs was 47.5, 42.5, and 16.9 μm, respectively. The decantability of the settled flocs by TiCl4 coagulant was similar to that by FeCl3 coagulant and much higher than that of Al 2(SO4)3. The photocatalyst from wastewater (PFW) produced by TiCl4 flocculation was characterized by X-ray diffraction, BET surface area, scanning electron microscopy/energy dispersive X-ray, transmission electron microscopy, photocatalytic activity, and X-ray photoelectron spectroscopy. The resulting PFW was found to be superior to commercial TiO2 (P-25) in terms of photocatalytic activity and surface area. The PFW was also found to be mainly doped with C and P atoms. The atomic percentage of the PFW was TiO1.42C0.44P 0.14. © 2007 American Chemical Society

Atomic-scale depth selectivity of soft x-ray resonant Kerr effect

A study was performed to demonstrate that soft x-ray Kerr rotation, ??K, versus incident grazing angle, ??, and energy, hv, measurements provide an extremely large depth selectivity on the atomic scales even in an ultrathin single layer, simply by choosing appropriate ?? and hv around the resonant regions. Both the experimental and simulation results of ?? vs ??K measurements were considered for depth-varying magnetization reversals in a 3.5-nm-thick Co layer of NiFe/FeMn/Co/Pd films.open161

Soft x-ray resonant magneto-optical Kerr effect as a depth-sensitive probe of magnetic heterogeneity: Its application to resolve helical spin structures using linear p polarization

We have calculated the soft x-ray resonant Kerr intensities as a function of the incident grazing angle of linearly p-polarized waves from the model spin structures, where the chirality (handedness) of the spin spirals (twist in depth) in a magnetic layer and the periodicity of a unit spiral are designed to vary. Variations in the chirality and the periodicity lead to noticeable changes in the Kerr intensity versus the grazing angle, which is due not only to a large sensitivity of the Kerr intensity of the linear p polarization to both the magnitude and direction of the transverse components of magnetizations, but also to a large dependence of the depth sensitivity on the grazing angle at the resonance regions. The measurement and analysis of the specular Kerr intensity are relatively straightforward in determining the inhomogeneous spin structures in depth, compared to those of the Kerr rotation and ellipticity. This is proven to be a convenient and useful probe to determine the handedness of spin spiral structures, as well as to resolve the detailed magnetic heterostructures in depth in ultrathin-layered films.open4

Accounting conservatism and bankruptcy risk

Date posted: June 6, 2010 ; Last revised: July 14, 2015This study examines the relation between accounting conservatism and bankruptcy risk using a large sample of U.S listed firms from fiscal year 1989 to 2007. We present evidence that unconditional and conditional conservatism generally mitigate subsequent bankruptcy risk by creating cushions for bad times and reducing information asymmetry about bad news. We identify two channels for accounting conservatism to mitigate bankruptcy risk: enhancing cash holdings and constraining earnings management. The effect of accounting conservatism does not change for firms with extreme distress and income smoothing, but weakens for firms with debt contracts referenced by credit default swaps (CDS), consistent with CDS lowering debtholder monitoring. Results are robust to reverse causality, relations between unconditional and conditional conservatism, and alternative measures of bankruptcy risk and accounting conservatism. These findings extend research on accounting conservatism, bankruptcy risk and debt contracting, and help inform debates regarding conservatism's role as a pervasive property and long-standing tenet of financial accounting.postprin

Magnetoresistive biosensors with on-chip pulsed excitation and magnetic correlated double sampling.

Giant magnetoresistive (GMR) sensors have been shown to be among the most sensitive biosensors reported. While high-density and scalable sensor arrays are desirable for achieving multiplex detection, scalability remains challenging because of long data acquisition time using conventional readout methods. In this paper, we present a scalable magnetoresistive biosensor array with an on-chip magnetic field generator and a high-speed data acquisition method. The on-chip field generators enable magnetic correlated double sampling (MCDS) and global chopper stabilization to suppress 1/f noise and offset. A measurement with the proposed system takes only 20 ms, approximately 50× faster than conventional frequency domain analysis. A corresponding time domain temperature correction technique is also presented and shown to be able to remove temperature dependence from the measured signal without extra measurements or reference sensors. Measurements demonstrate detection of magnetic nanoparticles (MNPs) at a signal level as low as 6.92 ppm. The small form factor enables the proposed platform to be portable as well as having high sensitivity and rapid readout, desirable features for next generation diagnostic systems, especially in point-of-care (POC) settings

Soft x-ray resonant magneto-optical Kerr effect as a depth-sensitive probe of magnetic heterogeneity: A simulation approach

We report a noticeable depth sensitivity of soft x-ray resonant magneto-optical Kerr effect able to resolve depth-varying magnetic heterostructures in ultrathin multilayer films. For various models of depth-varying magnetization orientations in an ultrathin Co layer of realistic complex layered structures, we have calculated the Kerr rotation, ellipticity, intensity spectra versus grazing incidence angle ??, and their hysteresis loops at different values of ?? for various photon energies ?? 's near the Co resonance regions. It is found from the simulation results that the Kerr effect has a much improved depth sensitivity and that its sensitivity varies remarkably with ?? and ?? in the vicinity of the resonance regions. These properties originate from a rich variety of wave interference effects superimposed with noticeable features of the refractive and absorptive optical effects near the resonance regions. Consequently, these allow us to resolve depth-varying magnetizations and their reversals varying with depth in a single magnetic layer and allow us to distinguish interface magnetism from the bulk properties in multilayer films. In this paper, the depth sensitivity of the Kerr effect with an atomic-scale resolution is demonstrated and discussed in details in several manners with the help of model simulations for various depth-varying spin configurations.open9