1,410 research outputs found
Efficient wideband electromagnetic scattering computation for frequency dependent lossy dielectrics using WCAWE
This paper presents a model order reduction algorithm for the volume electric field integral equation (EFIE) formulation, that achieves fast and accurate frequency sweep calculations of electromagnetic wave scattering. An inhomogeneous, two-dimensional, lossy dielectric object whose material is characterized by a complex permittivity which varies with frequency is considered. The variation in the dielectric properties of the ceramic BaxLa4Ti 2+xO 12+3x in the <1 GHz frequency range is investigated for various values of x in a frequency sweep analysis. We apply the well-conditioned asymptotic waveform evaluation (WCAWE) method to circumvent the computational complexity associated with the numerical solution of such formulations. A multipoint automatic WCAWE method is also demonstrated which can produce an accurate solution over a much broader bandwidth. Several numerical examples are given on order to illustrate the accuracy and robustness of the proposed methods
Arnoldi model order reduction for electromagnetic wave scattering computation
This paper presents a model order reduction (MOR) algorithm for the volume integral equation formulation of electromagnetic wave scattering. We apply the Arnoldi algorithm to circumvent the computational complexity associated with the numerical solution of such formulations. An approximate extension of the Arnoldi algorithm to the problem of wave scattering from an inhomogeneous body is introduced and implemented. Numerical examples are presented to demonstrate the accuracy of our approximate extension
Accelerated source-sweep analysis using a reduced-order model approach
This paper is concerned with the development of a model-order reduction (MOR) approach for the acceleration of a source-sweep analysis using the volume electric field integral equation (EFIE) formulation. In particular, we address the prohibitive computational burden associated with the repeated solution of the two-dimensional electromagnetic wave scattering problem for source-sweep analysis. The method described within is a variant of the Krylov subspace approach to MOR, that captures at an early stage of the iteration the essential features of the original system. As such these approaches are capable of creating very accurate low-order models. Numerical examples are provided that demonstrate the speed-up achieved by utilising these MOR approaches when compared against a method of
moments (MoM) solution accelerated by use of the Fast Fourier Transform (FFT)
Approved and investigational fluorescent optical imaging agents for disease detection in surgery
Fluorescent optical imaging is becoming an increasingly attractive imaging tool that physicians can utilise as it can detect previously 'unseen' changes in tissue at a cellular level that are consistent with disease. This is possible using a range of fluorescently labelled imaging agents that, once excited by specific wavelengths of light, can illuminate damaged and diseased tissues. For surgeons, such agents can permit dynamic, intraoperative imaging providing a real-time guide as they resect diseased tissue
COVID-19 profit warnings: Delivering bad news in a time of crisis
Abstract
Profit warnings (large negative earnings surprises) are important corporate reporting documents for delivering bad news and a distinctive corporate communication genre. The 2020 COVID-19 exogenous shock provides a unique worldwide crisis context for company disclosure of bad news.
The research develops a genre-based typology/analytical framework for assessing COVID-19 profit warningsâ quality comprising: (1) Four profit warning/forecast quality characteristics and (2) Eight profit warning/forecast disclosures. For a sample of 160 profit-warning documents, the research manually analyses their content, culminating in a disclosure quality score/index. The research tests a model of the factors influencing disclosure quality.
The research finds companies regress to silence when investors most need guidance and poor-quality disclosure, coy ambiguous language, possibly reflecting minimal regulatory guidance on this form of corporate report. Two variables are significant â Profit warnings disclosed following Financial Reporting Council guidance are of higher quality and quality varies by industry. The paper finds faux disclosure and the performativity of disclosure, which may allow boards of directors to tick-box compliance with market abuse regulations. The paper concludes with recommendations for policymakers on improvements required to enhance the quality of these highly important corporate documents.publishedVersio
Openness, Anti-Gay Attitudes, and Intervention: Predicting the Time to Stop Anti-Gay Aggression
The language of profit warnings: a case of denial, defiance, desperation and defeat
Taking a communication perspective, the paper explores management's rhetoric in profit warnings, whose sole purpose is to disclose unexpected bad news. Design/methodology/approach Adopting a close-reading approach to text analysis, the authors analyse three profit warnings of the now-collapsed Carillion, contrasting the rhetoric with contemporaneous investor conference calls to discuss the profit warnings and board minutes recording boardroom discussions of the case company's precarious financial circumstances. The analysis applies an Aristotelian framework, focussing on logos (appealing to logic and reason), ethos (appealing to authority) and pathos (appealing to emotion) to examine how Carillion's board and management used language to persuade shareholders concerning the company's adverse circumstances. Findings As non-routine communications, the language in profit warnings displays and mimics characteristics of routine communications by appealing primarily to logos (logic and reason). The rhetorical profiles of investor conference calls and board meeting minutes differ from profit warnings, suggesting a different version of the story behind the scenes. The authors frame the three profit warnings as representing three stages of communication as follows: denial, defiance and desperation and, for our case company, ultimately, culminating in defeat. Research limitations/implications The research is limited to the study of profit warnings in one case company. Originality/value The paper views profit warnings as a communication artefact and examines the rhetoric in these corporate documents to elucidate their key features. The paper provides novel insights into the role of profit warnings as a corporate communication vehicle/genre delivering bad news.publishedVersio
Models of Inclusion in Child Care: Child Care that Works for Children with Emotional and/or Behavioral Challenges: Family Member Perceptions
Although 5-10% of employed parents care for a child with emotional or behavioral challenges (EBCs) (Emlen, 1997), family support resources are notably lacking. A recent focus group study of 41 working parents (Rosenzweig, Brennan, & Ogilvie, 2002) found child care to be particularly difficult to find and maintain for families that included children with EBCs. Participants reported a number of barriers to child care arrangements that could successfully meet their family\u27s needs. First, since few qualified providers had the expertise to meet the needs of children with EBCs, arrangements were difficult to find. A combination of the lack of quality care in general, and few qualified providers for children with emotional or behavioral problems, created a nearly impossible situation for working families looking for child care. The aim of the Models of Inclusion in Child Care study (MICC) was to identify and investigate programs and strategies that improve access for families of children with emotional or behavioral disorders to child care that is inclusive, family-centered, culturally competent, and of high quality
Openness, Anti-Gay Attitudes, and Intervention: Predicting the Time to Stop Anti-Gay Aggression
Previous research using self-report measures found that the Big-Five personality trait openness to experience was the strongest predictor of attitudes toward gay men and lesbians. A secondary data analysis was conducted to evaluate the mediation between openness levels and the time to intervene as a bystander to an anti-gay aggressive scenario. Participants (n = 65) were self-identified heterosexual male undergraduate students who witnessed a staged scene of anti-gay aggression. During the experiment, one confederate was verbally aggressive toward another, ostensibly gay, confederate; participants chose whether and when to intervene. Participants then completed a battery of measures, including the Big Five Personality Inventory (BFI), and the Attitudes Toward Lesbian and Gay Men Scale (ATLG). Openness to experience significantly predicted attitudes toward gay men, which in turn significantly predicted participantsâ the time it took participants to intervene. The results highlight the importance of examining both attitudes and personality traits in predicting bystander behavior. These findings may inform bystander intervention techniques and other programs aimed to reduce anti-gay aggression
Librarian role-playing as a method for assessing student information literacy skills
Researchers and practitioners alike have long investigated the effectiveness of information literacy instruction, addressing what to measure regarding student learning and how to measure it. The purpose of this paper is twofold. First, we review measures and methods that have been developed to assess student learning that results from information literacy instruction. We then present a study in which we employed a new research method of librarian role-playing to examine the extent to which college students are capable of demonstrating their information literacy skills while acting as an academic librarian. We also incorporated card-sorting exercises, asking about their perceived search difficulty before and after the role-playing exercise. Ten role-playing sessions were conducted by recruiting undergraduate students who had attended an information literacy instruction session 3-4-months prior as a part of their English writing course. Results showed that the librarian role-playing method provided opportunities for participants to recall and reflect upon what they learned from information literacy instruction effectively. Results also indicated that the role-playing method is potentially effective in developing studentsâ meta-cognition about their search behavior.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151962/1/pra218_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151962/2/pra218.pd
- âŠ