398 research outputs found

    Table 1. Quick reference data Symbol Parameter Conditions Min Typ Max Unit VDS drain-source voltage Tj = 25 °C

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    1. General description P-channel enhancement mode Field-Effect Transistor (FET) in a leadless ultra small DFN1010D-3 (SOT1215) Surface-Mounted Device (SMD) plastic package using Trench MOSFET technology. 2. Features and benefits • Trench MOSFET technology • Leadless ultra small and ultra thin SMD plastic package: 1.1 × 1.0 × 0.37 mm • Exposed drain pad for excellent thermal conduction • ElectroStatic Discharge (ESD) protection 1 kV HBM • Drain-source on-state resistance RDSon = 100 m

    A laboratory based system for Laue micro x-ray diffraction

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    A laboratory diffraction system capable of illuminating individual grains in a polycrystalline matrix is described. Using a microfocus x-ray source equipped with a tungsten anode and prefigured monocapillary optic, a micro-x-ray diffraction system with a 10 mum beam was developed. The beam profile generated by the ellipsoidal capillary was determined using the"knife edge" approach. Measurement of the capillary performance, indicated a beam divergence of 14 mrad and a useable energy bandpass from 5.5 to 19 keV. Utilizing the polychromatic nature of the incident x-ray beam and application of the Laue indexing software package X-Ray Micro-Diffraction Analysis Software, the orientation and deviatoric strain of single grains in a polycrystalline material can be studied. To highlight the system potential the grain orientation and strain distribution of individual grains in a polycrystalline magnesium alloy (Mg 0.2 wt percent Nd) was mapped before and after tensile loading. A basal (0002) orientation was identified in the as-rolled annealed alloy; after tensile loading some grains were observed to undergo an orientation change of 30 degrees with respect to (0002). The applied uniaxial load was measured as an increase in the deviatoric tensile strain parallel to the load axis (37 References)

    Comment on Viscous Stability of Relativistic Keplerian Accretion Disks

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    Recently Ghosh (1998) reported a new regime of instability in Keplerian accretion disks which is caused by relativistic effects. This instability appears in the gas pressure dominated region when all relativistic corrections to the disk structure equations are taken into account. We show that he uses the stability criterion in completely wrong way leading to inappropriate conclusions. We perform a standard stability analysis to show that no unstable region can be found when the relativistic disk is gas pressure dominated.Comment: 9 pages, 4 figures, uses aasms4.sty, submitted for ApJ Letter

    Global survey of the frequency of atrial fibrillation-associated stroke: embolic stroke of undetermined source global registry

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    Background and Purpose—Atrial fibrillation (AF) is increasingly recognized as the single most important cause of disabling ischemic stroke in the elderly. We undertook an international survey to characterize the frequency of AF-associated stroke, methods of AF detection, and patient features. Methods—Consecutive patients hospitalized for ischemic stroke in 2013 to 2014 were surveyed from 19 stroke research centers in 19 different countries. Data were analyzed by global regions and World Bank income levels. Results—Of 2144 patients with ischemic stroke, 590 (28%; 95% confidence interval, 25.6–29.5) had AF-associated stroke, with highest frequencies in North America (35%) and Europe (33%) and lowest in Latin America (17%). Most had a history of AF before stroke (15%) or newly detected AF on electrocardiography (10%); only 2% of patients with ischemic stroke had unsuspected AF detected by poststroke cardiac rhythm monitoring. The mean age and 30-day mortality rate of patients with AF-associated stroke (75 years; SD, 11.5 years; 10%; 95% confidence interval, 7.6–12.6, respectively) were substantially higher than those of patients without AF (64 years; SD, 15.58 years; 4%; 95% confidence interval, 3.3–5.4; P<0.001 for both comparisons). There was a strong positive correlation between the mean age and the frequency of AF (r=0.76; P=0.0002). Conclusions—This cross-sectional global sample of patients with recent ischemic stroke shows a substantial frequency of AF-associated stroke throughout the world in proportion to the mean age of the stroke population. Most AF is identified by history or electrocardiography; the yield of conventional short-duration cardiac rhythm monitoring is relatively low. Patients with AF-associated stroke were typically elderly (>75 years old) and more often women

    An Empirical Study of Bots in Software Development -- Characteristics and Challenges from a Practitioner's Perspective

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    Software engineering bots - automated tools that handle tedious tasks - are increasingly used by industrial and open source projects to improve developer productivity. Current research in this area is held back by a lack of consensus of what software engineering bots (DevBots) actually are, what characteristics distinguish them from other tools, and what benefits and challenges are associated with DevBot usage. In this paper we report on a mixed-method empirical study of DevBot usage in industrial practice. We report on findings from interviewing 21 and surveying a total of 111 developers. We identify three different personas among DevBot users (focusing on autonomy, chat interfaces, and "smartness"), each with different definitions of what a DevBot is, why developers use them, and what they struggle with. We conclude that future DevBot research should situate their work within our framework, to clearly identify what type of bot the work targets, and what advantages practitioners can expect. Further, we find that there currently is a lack of general purpose "smart" bots that go beyond simple automation tools or chat interfaces. This is problematic, as we have seen that such bots, if available, can have a transformative effect on the projects that use them.Comment: To be published at the ACM Joint European Software Engineering Conference and Symposium on the Foundations of Software Engineering (ESEC/FSE

    Ascertaining the notion of board accountability in Chinese listed companies

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    Accountability is a concept that has been frequently referred to in Anglo-American systems and in the OECD’s corporate governance documents, as well as in the English translations of corporate governance documents from non-English speaking jurisdictions. It is in the Anglo-American literature, in particular, where the word finds prominence. It has been suggested in China that accountability is one of the basic principles of corporate governance that needs to be consistently enforced. But does this mean that board accountability, as it has been provided for in the Anglo-American system, is actually an element of Chinese corporate governance? If not, should it be adopted? Or should China develop a concept that is more appropriately included as a critical part of its own particular corporate governance needs? The paper aims to address these matters in order to ascertain where Chinese corporate governance stands on accountability as far as the boards of large listed companies are concerned, and what it should do. We opine that while there are elements of accountability in Chinese corporate governance, it does not have the form of accountability embraced in Anglo-American systems. But, it is argued, as China moves from having a system totally based on administrative governance to one that is based more on economic governance the kind of approach that applies in Anglo-American jurisdictions is likely to become more relevant. Within a hybrid corporate governance system combining elements of both administrative and economic governance, we develop a unique “wenze system” with forms and characters of accountability that is likely to develop to address the needs of corporate governance in China and the fostering of its listed companies
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