Silicon carbide (SiC) vertical-diffused metal oxide field transistor (VDMOSFET) is an important power device for aerospace application. However, it is sensitive to heavy particles radiation in space ...which can cause catastrophic single-event effects (SEEs). In this article, a method of SEE hardening at a high linear energy transfer (LET) value range is studied to the 1.2 kV-rated SiC VDMOSFET by the 2-D numerical simulator SILVACO TCAD. Simulation results illustrate that, compared with the VDMOSFET which only has four buffer (FB-VDMOSFET) layers, the improved MOSFET could increase the abilities of single-event burnout (SEB) and the single-event gate rupture (SEGR) of the device effectively. At the same time, the proposed MOSFET has the lower specific ON-resistance (<inline-formula> <tex-math notation="LaTeX">{R}_{\text {on, sp}} </tex-math></inline-formula>) at room temperature. As a result, the gate oxide of the FB-VDMOSFET has reached 7.5 MV/cm and the maximum temperature reached 2480 K at a voltage of 600 V and an LET value of 0.5 pC/<inline-formula> <tex-math notation="LaTeX">\mu \text{m} </tex-math></inline-formula>. However, the maximum temperature of the improved VDMOSFET is 2150 K when <inline-formula> <tex-math notation="LaTeX">{V}_{\mathrm {DS}} </tex-math></inline-formula> = 950 V.
This research analysed the Gold Coast 2018 Commonwealth Games (GC2018) as a Field Configuring Event (FCE). The research develops understanding around the key actors, processes and products of field ...configuration prompted in the host community of a major event. A qualitative single-case study research design was used that relied on interview data, participant observations, and organisational documents. Findings demonstrated how boundary work by GC2018 field-level governance actors yielded a focus on achieving legacy outcomes for a select few host community stakeholders. This study adds new insight on the persistence of “the legacy rhetoric” in event management. Recognition of the exclusionary nature of boundary work associated with field governance around major events emerged as a key prerequisite for shifting thinking beyond the legacy rhetoric and towards a more holistic leveraging perspective.
In this study, the consensus problem is investigated for the multi-agent systems with antagonistic interactions and communication delay under the event-triggered control protocol. For the directed ...signed networks, an event-based interaction protocol is first proposed. Then it is shown that with the proposed protocol, bipartite consensus can be realised for the structurally balanced signed networks with distributed communication delay. As for the structurally unbalanced signed networks with communication delay, it is proved that consensus can also be reached under the proposed event-triggered scheme and the final consensus value is zero. It should be emphasised that the proposed event-triggered controllers depend only on the local information. Furthermore, Zero phenomenon can be excluded, and the positive lower bound of the inter-event times is simultaneously provided. Finally, the effectiveness of proposed event-triggered schemes is demonstrated by one numerical example.
The Event Horizon Telescope (EHT) collaboration has recently released the first image of a black hole (BH), opening a new window onto tests of general relativity in the strong field regime. In this ...paper, we derive constraints on the nature of M87* (the supermassive object at the center of the galaxy M87), exploiting the fact that its shadow appears to be highly circular, and using measurements of its angular size. We first consider the simple case where M87* is assumed to be a Kerr BH. We find that the inferred circularity of M87* excludes Kerr BHs with observation angle θobs≳45° for dimensionless rotational parameter 0.95≲a*≤1 whereas the observation angle is unbounded for a*≲0.9. We then consider the possibility that M87* might be a superspinar, i.e., an object described by the Kerr solution and spinning so fast that it violates the Kerr bound by having |a*|>1. We find that, within certain regions of parameter space, the inferred circularity and size of the shadow of M87* do not exclude the possibility that this object might be a superspinar.
Experimental heavy-ion responses of silicon carbide (SiC) junction barrier Schottky (JBS) diodes are presented. Measured data indicate that heavy ions having range less than the epitaxial thickness ...do not cause degradation or catastrophic failure, even with the device biased above the rated breakdown voltage. Measured data also indicate that when the heavy ions have range longer than the epitaxial layer thickness, the devices exhibit degradation as single-event leakage current (SELC), as well as catastrophic single-event burnout (SEB) at biases less than half of the rated breakdown voltage. Device failure was observed when irradiating with high-energy ions having long ranges, but not when irradiating with low-energy ions that stop in the epitaxial layer. Mechanisms of observed heavy-ion effects are examined with technology computer aided design (TCAD) device modeling.
Research on event-based processing and analysis of media is receiving an increasing attention from the scientific community due to its relevance for an abundance of applications, from consumer video ...management and video surveillance to lifelogging and social media. Events have the ability to semantically encode relationships of different informational modalities, such as visual–audio–text, time, involved agents and objects, with the spatio-temporal component of events being a key feature for contextual analysis. This unveils an enormous potential for exploiting new information sources and opening new research directions. In this paper, we survey the existing literature in this field. We extensively review the employed conceptualization of the notion of event in multimedia, the techniques for event representation and modeling, the feature representation and event inference approaches for the problems of event detection in audio, visual, and textual content. Furthermore, we review some key event-based multimedia applications, and various benchmarking activities that provide solid frameworks for measuring the performance of different event processing and analysis systems. We provide an in-depth discussion of the insights obtained from reviewing the literature and identify future directions and challenges.
•We survey the literature in event-based media processing and analysis.•We examine the different definitions of events.•We study various techniques for event representation and modeling.•We survey feature representation, event inference approaches in multimedia content.•We review event-based multimedia applications and various benchmarking activities.
This document describes the radiation environments, physical mechanisms, and test philosophies that underpin radiation hardness assurance test methodologies. The natural space radiation environment ...is presented, including the contributions of both trapped and transient particles. The effects of shielding on radiation environments are briefly discussed. Laboratory radiation sources used to simulate radiation environments are covered, including how to choose appropriate sources to mimic environments of interest. The fundamental interactions of radiation with materials via direct and indirect ionization are summarized. Some general test considerations are covered, followed by in-depth discussions of physical mechanisms and issues for total dose and single-event effects testing. The purpose of this document is to describe why the test protocols we use are constructed the way they are. In other words, to answer the question: "Why do we test it that way"?
Motivated by the risen linkage between events and Bitcoin return, this paper first defines Bitcoin-related events (BREs) based on the change points analysis and then divides these events into two ...categories. Furthermore, we model the impact of BREs on the Bitcoin market activities, using an event study methodology and a GARCH-X model. Empirical results show that the shock directions of Bitcoin-related events on Bitcoin price are heavily correlative with types of events. Additionally, there is a significant positive influence of domestic events on reaction volatility, whereas the foreign events impose their influences on both the expectations of market reactions and volatility.
•This paper firstly identifies the Bitcoin-related events based on the change points analysis and divided these events into two categories.•We further explore the Bitcoin price reactions to Bitcoin-related events.•Bitcoin-related events, views as a real change of Bitcoin return, are very frequent in the year 2013 or 2017.•The shock directions of Bitcoin-related events on Bitcoin price are heavily correlative with types of events.•The role of Bitcoin-related events information in influencing market reactions are significant and heterogeneous.
This study contributes to the extant literature on the leveraging of event portfolios, by applying the Model of Event Portfolio Tourism Leverage to a case study of the Volvo Ocean Race in Cardiff, ...UK. Through an examination of the various components of the model, the research demonstrates
the value of the strategies and tactics it proposes, including the amplification of visitor numbers, diversification of tourism offerings, extension of the tourism season, fostering of event tourism networks, consolidation of destination assets, and bolstering of destination authenticity.
Empirical data collected from three separate surveys, strategy documents, and feedback from stakeholders are analyzed to support this argument. The study also acknowledges some challenges to strategic portfolio management, particularly due to the fragmented nature of events suppliers in destinations
and the difficulty in assessing the impact of leveraging actions, in the absence of benchmark data related to event visitors.
This conceptual article argues for a broader view of the role of events in social systems. When analyzed as social phenomena, events can be seen as social actors that have the potential to both ...sustain and transform social systems. The maintenance of social systems is often reliant
on iterative events, regularly occurring celebrations that tend to confirm social structures. In contrast, pulsar events have the potential to transform social structures. In this sense events can be seen as actors that have important influences on social systems, particularly in linking localized
small world networks with the global space of flows. These ideas are explored through the case of Barcelona, which illustrates the interplay between these different types of events in their total portfolio, and how the extension of ritual in the sense of Collins can also contribute to the
generation of new relationships and practices in the contemporary network society. Barcelona is examined as an eventful city in which the alternation of continuity through iterative events and change through pulsar events contributes to increasing the network effects of events.
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