302 research outputs found

    Wave Propagation Analysis using High-Order Finite Element Methods: Spurious Oscillations excited by Internal Element Eigenfrequencies

    Get PDF
    From a computational point of view, the numerical analysis of ultrasonic guided waves is still a very demanding task. Because of the high-frequency regime both a fine spatial and temporal discretization is required. To minimize the numerical costs, efficient and robust algorithms ought to be developed. One promising idea is therefore to focus on high-order finite element methods (ho-FEM).The current article investigates the behavior of the p-version of the finite element method (p-FEM) and the spectral element method (SEM) with respect to the existence of spurious oscillations in the solution. Convergence studies have shown that it is possible to observe non-physical oscillations under certain conditions. These parasitic vibrations, however, significantly deteriorate the accuracy of the simulation. For this reason, we analyse this phenomenon in detail and propose solutions to avoid its occurrence.Without loss of generality, we employ a two-dimensional plane strain model to derive a guideline as to how to avoid these spurious oscillations, placing a special emphasis on the relation between the element size, the polynomial degree of the high-order shape functions and the excitation frequency.Our results show that accurate simulations are possible if the model is generated according to the proposed methodology. Moreover, the implementation of the guideline into an existing finite element software is straightforward; these properties turn the method into a useful tool for practical wave propagation analyses

    A systematic examination of actor and trainee interviewer behaviour during Joint Investigative Interviewing Training

    Get PDF
    This study is the first systematic examination of trainee interviewer and actor behaviour during Joint Investigative Interviewing Training (JIIT) simulations across two training sites in Scotland. As expected, interviewers were poor at adhering to best practice interview guidelines in the pre-substantive and closure phases of the interviews. Although invitations were used within the range of best practice, they were not used more often and did not elicit more allegation-related details than directive questions. Critically, actors’ responses to invitations were less informative than their responses to all other question types. Furthermore, large differences were observed between the two training sites in the number of questions asked and amount of information elicited by interviewers. Our results show that 1) trainee interviewers are not utilising simulations to practice all required interviewing skills, 2) adult actors are not reinforcing interviewers’ use of invitations as intended, and 3) trainee interviewers are not being afforded the same opportunities to practice their skills due to variation in resources across Scotland. We recommend improvements to the JIIT programme to address these concerns

    An experimental examination of the effects of alcohol consumption and exposure to misleading post event information on remembering a hypothetical rape scenario

    Get PDF
    We experimentally examined the effects of alcohol consumption and exposure to misleading post event information on memory for a hypothetical interactive rape scenario. We used a 2 beverage (alcohol versus tonic water) x 2 expectancy (told alcohol versus told tonic) factorial design. Participants (N = 80) were randomly assigned to conditions. They consumed alcohol (mean BAC = .06%) or tonic water before engaging in the scenario. Alcohol expectancy was controlled by telling participants they were consuming alcohol or tonic water alone, irrespective of the actual beverage they were consuming. Approximately a week later, participants were exposed to a misleading post event narrative and then recalled the scenario and took a recognition test. Participants who were told that they had consumed alcohol rather than tonic reported fewer correct details; but, they were no more likely to report incorrect or misleading information. The confidence-accuracy relationship for control and misled items was similar across groups, and there was some evidence that metacognitive discrimination was better for participants who were told that they had consumed alcohol compared to those told they had tonic water. Implications for interviewing rape victims are discussed

    Berechnung der Verformung des Gestells einer Werkzeugmaschine

    Get PDF
      &nbsp

    Growth inhibition in clonal subpopulations of a human epithelioid sarcoma cell line by retinoic acid and tumour necrosis factor alpha.

    Get PDF
    Epithelioid sarcoma is a highly malignant soft tissue tumour that is refractory to conventional chemotherapy and irradiation. Since permanent cell lines of this tumour are extremely rare, in vitro data on compounds with significant antiproliferative effects are still lacking. Therefore, we investigated the effects of retinoic acid (RA) and tumour necrosis factor alpha (TNF-alpha) on tumour cell proliferation of three different clonal subpopulations (GRU-1A, GRU-1B, GRU-1C) derived from the same human epithelioid sarcoma cell line, GRU-1. In GRU-1A both RA (P=0.01) and TNF-alpha (P=0.002) exhibited highly significant and dose-dependent growth inhibitory effects, which could further be increased by a combined application of both compounds (P<0.006). GRU-1B proved to be sensitive to RA (P=0.006), whereas no response to TNF-alpha was observed. GRU-1C was resistant to both RA and TNF-alpha. The antiproliferative effect of TNF-alpha was mediated by TNF receptor 1(TNF-R1) and correlated positively with both the number of TNF-R1 per cell and receptor affinity. No correlation was detected between RA-induced growth inhibition and the expression pattern of the RA receptors (RARs) RAR-alpha, RAR-beta, and RAR-gamma. Plating efficiency, however, could exclusively be reduced by RA in GRU-1B, the only cell line expressing RAR-alpha. Taken together, these data are the first showing significant antiproliferative effects in human epithelioid sarcoma by RA and TNF-alpha. Whereas the TNF-alpha response seems to depend on the expression of TNF-R1, no simple correlation could be found between RA sensitivity and the expression pattern of RARs

    The ABCD of usability testing

    Get PDF
    We introduce a methodology for tracking and auditing feedback, errors and suggestions for software packages. This short paper describes how we innovate on the evaluation mechanism, introducing an (Antecedent, Barrier, Consequence and Development) ABCD form, embedded within an eParticipation platform to enable end users to easily report on any usability issues. This methodology will be utilised to improve the STEP cloud eParticipation platform (part of the current STEP Horizon2020 project http://step4youth.eu. The platform is currently being piloted in real life contexts, with the participation of public authorities that are integrating the eParticipation platform into their regular decision-making practices. The project is involving young people, through engagement and motivation strategies and giving them a voice in Environmental decision making at the local level. The pilot evaluation aims to demonstrate how open engagement needs to be embedded within public sector processes and the usability methodology reported here will help to identify the key barriers for wide scale deployment of the platform
    • …
    corecore