Quantifying Engagement with Citations on Wikipedia

Wikipedia, the free online encyclopedia that anyone can edit, is one of the most visited sites on the Web and a common source of information for many users. As an encyclopedia, Wikipedia is not a source of original information, but was conceived as a gateway to secondary sources: according to Wikipedia's guidelines, facts must be backed up by reliable sources that reflect the full spectrum of views on the topic. Although citations lie at the very heart of Wikipedia, little is known about how users interact with them. To close this gap, we built client-side instrumentation for logging all interactions with links leading from English Wikipedia articles to cited references during one month, and conducted the first analysis of readers' interaction with citations on Wikipedia. We find that overall engagement with citations is low: about one in 300 page views results in a reference click (0.29% overall; 0.56% on desktop; 0.13% on mobile). Matched observational studies of the factors associated with reference clicking reveal that clicks occur more frequently on shorter pages and on pages of lower quality, suggesting that references are consulted more commonly when Wikipedia itself does not contain the information sought by the user. Moreover, we observe that recent content, open access sources and references about life events (births, deaths, marriages, etc) are particularly popular. Taken together, our findings open the door to a deeper understanding of Wikipedia's role in a global information economy where reliability is ever less certain, and source attribution ever more vital.Comment: The Web Conference WWW 2020, 10 page

Frequency fluctuations in silicon nanoresonators

Frequency stability is key to performance of nanoresonators. This stability is thought to reach a limit with the resonator's ability to resolve thermally-induced vibrations. Although measurements and predictions of resonator stability usually disregard fluctuations in the mechanical frequency response, these fluctuations have recently attracted considerable theoretical interest. However, their existence is very difficult to demonstrate experimentally. Here, through a literature review, we show that all studies of frequency stability report values several orders of magnitude larger than the limit imposed by thermomechanical noise. We studied a monocrystalline silicon nanoresonator at room temperature, and found a similar discrepancy. We propose a new method to show this was due to the presence of frequency fluctuations, of unexpected level. The fluctuations were not due to the instrumentation system, or to any other of the known sources investigated. These results challenge our current understanding of frequency fluctuations and call for a change in practices

Numerical Analysis for Spread Option Pricing Model in Illiquid underlying Asset Market: Full Feedback Model

This paper performs the numerical analysis and the computation of a Spread option in a market with imperfect liquidity. The number of shares traded in the stock market has a direct impact on the stock’s price. Thus, we consider a full-feedback model in which price impact is fully incorporated into the model. The price of a Spread option is characterized by a nonlinear partial differential equation. This is reduced to linear equations by asymptotic expansions. The Peaceman-Rachford scheme, as an alternating direction implicit method, is employed to solve the linear equations numerically. We discuss the stability and the convergence of the numerical scheme. Illustrative examples are included to demonstrate the validity and applicability of the presented method. Finally we provide a numerical analysis of the illiquidity effect in replicating an European Spread option; compared to the Black-Scholes model the price of the option is higher in the model with price impact

Cardiovascular responses to orotracheal intubation in patients undergoing coronary artery bypass grafting surgery: Comparing fiberoptic bronchoscopy with direct laryngoscopy

Background: The intubation by using fiberoptic brochoscop (FOB) can avoid the mechanical stimulus to oropharyngolaryngeal structures thereby it is likely to attenuate hemodynamic response during orotracheal intubation. Based on this hypothesis, we compared the hemodynamic responses to orotracheal intubation using an FOB and direct laryngoscope (DLS) in patients undergoing general anesthesia for coronary artery bypass grafting (CABG) surgery. Methods: Fifty patients with ASA physical status II and Mallampati score I and II were scheduled for elective CABG surgery under general anesthesia requiring orotracheal intubation were randomly allocated to either DLS group (n = 25) or FOB group (n = 25). The same protocol of anesthetic medications was used. Invasive systolic and diastolic blood pressure (SBP & DBP) and heart rate (HR) were recorded before and after anesthesia induction, during intubation and in the first and second minutes after intubation. The differences among the hemodynamic variables recorded over time and differences in the circulatory variables between the two study groups were compared. Results: Duration of intubation was shorter in DLS group (19.3 ± 4.7 sec) compared with FOB group (34.9 ± 9.8 sec; p = 0.0001). In both study groups basic SBP and DBP and HR were not significantly different (P >0.05). During the observation, there were no significant differences between the two groups in BP or HR at any time points or in their maximal values (all p values >0.05). Conclusion: We conclude that the FOB had no advantage in attenuating the hemodynamic responses to orotracheal intubation in patients undergoing CABG surgery

On Tikhonov Regularization Method in Calibration of Volatility Term-structure

Abstract: In this paper, we consider inverse problem arising in calibration of time-dependent volatility function from the Black-Scholes model and analyze its ill-posedness phenomena. The forward operator of the inverse problem under some consideration decomposes into an inner linear convolution operator and an outer nonlinear Nemytskii operator given by a Black-Scholes function. Using Chebyshev collocation method, we transfer the inner linear operator to a linear system. Since the resulting matrix equation is badly ill-conditioned, a regularized solution is obtained by employing the Tikhonov regularization method, while the choice of the regularization parameter are based on generalized cross-validation(GCV) and L-curve criterions. Numerical case studies illustrate the efficiency and accuracy of the presented method

On the radar: Predicting near-future surges in skills’ hiring demand to provide early warning to educators

10.1016/j.caeai.2021.100043Computers and Education: Artificial Intelligence3100043-10004