66 research outputs found

    Der verteilte Fahrerinteraktionsraum

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    Fahrrelevante und unterhaltungsbezogene Informationen werden, historisch betrachtet, rĂ€umlich getrennt im Fahrzeuginnenraum angeordnet: FĂŒr die Fahraufgabe notwendige Anzeigen befinden sich direkt vor dem Fahrer (Kombiinstrument und Head-Up Display) und Inhalte des Fahrerinformationssystems in der Mittelkonsole (zentrales Informationsdisplay). Aktuell ist eine Auflösung dieser strikten Trennung zu beobachten. Beispielsweise werden im Kombiinstrument TeilumfĂ€nge der Infotainmentinhalte abgerufen und bedient. Um dem Fahrer einen sicheren Umgang mit den zunehmenden Infotainmentinhalten zu ermöglichen, die KomplexitĂ€t des Fahrerinteraktionsraumes zu reduzieren und den Kundennutzen zu steigern, betrachtet die vorliegende Arbeit die derzeit isolierten Displays ganzheitlich und lotet die Grenzen der momentan strikten Informationsverteilung neu aus. Es werden Grundlagen fĂŒr die verkehrsgerechte Bedienung und Darstellung verteilter Informationen abhĂ€ngig von deren AnzeigeflĂ€che gelegt, Konzepte zur nutzerinitiierten Individualisierung entwickelt und das Zusammenspiel von unterschiedlichen AnzeigeflĂ€chen evaluiert. Die in dieser Arbeit durchgefĂŒhrten Studien zeigen, dass der rĂ€umlich verteilte Fahrerinteraktionsraum die Bedienung des Fahrerinformationssystems fĂŒr den Nutzer sicherer und attraktiver gestaltet

    Size Effects in Residual Stress Formation during Quenching of Cylinders Made of Hot-Work Tool Steel

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    The present work investigates the residual stress formation and the evolution of phase fractions during the quenching process of cylindrical specimens of different sizes. The cylinders are made of hot-work tool steel grade X36CrMoV5-1. A phase transformation kinetic model in combination with a thermomechanical model is used to describe the quenching process. Two phase transformations are considered for developing a modelling scheme: the austenite-to-martensite transformation and the austenite-to-bainite transformation. The focus lies on the complex austenite-to-bainite transformation which can be observed at low cooling rates. For an appropriate description of the phase transformation behaviour nucleation and growth of bainite are taken into account. The thermomechanical model contains thermophysical data and flow curves for each phase. Transformation induced plasticity (TRIP) is modelled by considering phase dependent Greenwood-Johnson parameters for martensite and bainite, respectively. The influence of component size on residual stress formation is investigated by the finite element package Abaqus. Finally, for one cylinder size the simulation results are validated by X-ray stress measurements

    Role of Adjuvant Multimodality Therapy After Curative-Intent Resection of Ampullary Carcinoma

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    Importance: Ampullary adenocarcinoma is a rare malignant neoplasm that arises within the duodenal ampullary complex. The role of adjuvant therapy (AT) in the treatment of ampullary adenocarcinoma has not been clearly defined. Objective: To determine if long-term survival after curative-intent resection of ampullary adenocarcinoma may be improved by selection of patients for AT directed by histologic subtype. Design, setting, and participants: This multinational, retrospective cohort study was conducted at 12 institutions from April 1, 2000, to July 31, 2017, among 357 patients with resected, nonmetastatic ampullary adenocarcinoma receiving surgery alone or AT. Cox proportional hazards regression was used to identify covariates associated with overall survival. The surgery alone and AT cohorts were matched 1:1 by propensity scores based on the likelihood of receiving AT or by survival hazard from Cox modeling. Overall survival was compared with Kaplan-Meier estimates. Exposures: Adjuvant chemotherapy (fluorouracil- or gemcitabine-based) with or without radiotherapy. Main outcomes and measures: Overall survival. Results: A total of 357 patients (156 women and 201 men; median age, 65.8 years [interquartile range, 58-74 years]) underwent curative-intent resection of ampullary adenocarcinoma. Patients with intestinal subtype had a longer median overall survival compared with those with pancreatobiliary subtype (77 vs 54 months; P = .05). Histologic subtype was not associated with AT administration (intestinal, 52.9% [101 of 191]; and pancreatobiliary, 59.5% [78 of 131]; P = .24). Patients with pancreatobiliary histologic subtype most commonly received gemcitabine-based regimens (71.0% [22 of 31]) or combinations of gemcitabine and fluorouracil (12.9% [4 of 31]), whereas treatment of those with intestinal histologic subtype was more varied (fluorouracil, 50.0% [17 of 34]; gemcitabine, 44.1% [15 of 34]; P = .01). In the propensity score-matched cohort, AT was not associated with a survival benefit for either histologic subtype (intestinal: hazard ratio, 1.21; 95% CI, 0.67-2.16; P = .53; pancreatobiliary: hazard ratio, 1.35; 95% CI, 0.66-2.76; P = .41). Conclusions and relevance: Adjuvant therapy was more frequently used in patients with poor prognostic factors but was not associated with demonstrable improvements in survival, regardless of tumor histologic subtype. The value of a multimodality regimen remains poorly defined
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