97 research outputs found

    High-frequency equivalent circuit of GaAs FET's for large-signal applications

    Get PDF
    The application of GaAs field effect transistors in digital circuits requires a valid description by an equivalent circuit at all possible gate and drain bias voltages for all frequencies from DC up to the gigahertz range. An equivalent circuit is presented which takes into account the gate current of positively biased transistors as well as the symmetrical nature of the devices at low drain voltages. A fast method of determining the elements of the equivalent circuit at all bias points without frequency limitations is presented. Direct computation from analytical expressions, without iteration, allows this parameter extraction procedure to be used for real-time on-wafer parameter extraction. Large-signal calculations are possible by inserting the voltage dependences evaluation for the elements into suitable simulation programs, such as SPICE

    Frequency dependent CV measurements of GaAs/AlGaAs heterostructures

    Get PDF
    A procedure is described to determine the carrier density profile in the channel of a FET by evaluating S-parameters measured over a broad frequency range. Applying this method to GaAs/AlGaAs heterostructures, a frequency dispersion of the gate capacitance has been found, which is attributed to a parasitic conducting channel

    VIVACE: A framework for the systematic evaluation of variability support in process-aware information systems

    Full text link
    Context: The increasing adoption of process-aware information systems (PAISs) such as workflow management systems, enterprise resource planning systems, or case management systems, together with the high variability in business processes (e.g., sales processes may vary depending on the respective products and countries), has resulted in large industrial process model repositories. To cope with this business process variability, the proper management of process variants along the entire process lifecycle becomes crucial. Objective: The goal of this paper is to develop a fundamental understanding of business process variability. In particular, the paper will provide a framework for assessing and comparing process variability approaches and the support they provide for the different phases of the business process lifecycle (i.e., process analysis and design, configuration, enactment, diagnosis, and evolution). Method: We conducted a systematic literature review (SLR) in order to discover how process variability is supported by existing approaches. Results: The SLR resulted in 63 primary studies which were deeply analyzed. Based on this analysis, we derived the VIVACE framework. VIVACE allows assessing the expressiveness of a process modeling language regarding the explicit specification of process variability. Furthermore, the support provided by a process-aware information system to properly deal with process model variants can be assessed with VIVACE as well. Conclusions: VIVACE provides an empirically-grounded framework for process engineers that enables them to evaluate existing process variability approaches as well as to select that variability approach meeting their requirements best. Finally, it helps process engineers in implementing PAISs supporting process variability along the entire process lifecycle. (C) 2014 Elsevier B.V. All rights reserved.This work has been developed with the support of MICINN under the project EVERYWARE TIN2010-18011.Ayora Esteras, C.; Torres Bosch, MV.; Weber, B.; Reichert, M.; Pelechano Ferragud, V. (2015). VIVACE: A framework for the systematic evaluation of variability support in process-aware information systems. Information and Software Technology. 57:248-276. https://doi.org/10.1016/j.infsof.2014.05.009S2482765

    Towards Certifiable Fault-Tolerant Actuation Architectures for UAVs

    Get PDF
    There is an increasing demand for integrating unmanned aerial vehicles (UAVs) into civilian airspaces. Consequently, onboard systems should be evaluated for possible threats to human life. This paper discusses future certification requirements for flight control actuators. A scheme is proposed for evaluating reliability requirements for flight control electro-mechanical actuators (EMAs) considering different flight control configurations. This work is part of the TEMA-UAV project, which aims at developing certifiable fault-tolerant actuation for future UAVs

    An 18-34-GHz dynamic frequency divider based on 0.2-μm AlGaAs/GaAs/AlGaAs quantum-well transistors

    Get PDF
    The design and performance of a dynamic frequency divider was presented. This digital IC demonstrates the ability of the authors' AlGaAs/GaAs/AlGaAs quantum-well FETs with gate lengths of 0.2 μm. Stable operation was achieved in the frequency range from 18 GHz up to 34 GHz with a power consumption of 250 mW. To the authors' knowledge, this is the best result ever reported for HEMT circuits, and is similar to the frequency limit achieved by use of AlGaAs/GaAs HBTs

    Correction to: First results on survival from a large Phase 3 clinical trial of an autologous dendritic cell vaccine in newly diagnosed glioblastoma

    Get PDF
    Following publication of the original article [1], the authors reported an error in the spelling of one of the author names. In this Correction the incorrect and correct author names are indicated and the author name has been updated in the original publication. The authors also reported an error in the Methods section of the original article. In this Correction the incorrect and correct versions of the affected sentence are indicated. The original article has not been updated with regards to the error in the Methods section.https://deepblue.lib.umich.edu/bitstream/2027.42/144529/1/12967_2018_Article_1552.pd

    Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors

    Get PDF
    Background Suicide is a leading cause of death worldwide, and nonfatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium (ISGC). The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via multitrait-based conditional and joint analysis, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders, and other known risk factors. Results Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, the latter of which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking behavior, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking behavior, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status, and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with nonpsychiatric traits remained largely unchanged. Conclusions Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.Peer reviewe
    corecore