957 research outputs found
The DV-Xα molecular-orbital calculation method
No full textThis multi-author contributed volume contains chapters featuring the development of the DV-Xα method and its application to a variety of problems in Materials Science and Spectroscopy written by leaders of the respective fields. The volume contains a Foreword written by the Chairs of Japanese and Korea DV-X alpha Societies. This book is aimed at individuals working in Quantum Chemistry
The Improvement Based on the DV-Hop Localization Algorithm for Wireless Sensor Networks
No full textAs the problems of lower localization accuracy appeared in the traditional DV-Hop algorithm，the
author analyzed three main factors that influence the localization accuracy of original DV-Hop algorithm which
started from the calculation of the average jump distance in algorithm and the calculation of node coordinates. The
author then proposed the calculation method of average jump distance based on the weighted correction of the ＲSSI
( Ｒeceive Signal Strength Indicator ) and the calculation method of unknown node coordinates based on the
correction of the total least squares ( TLS) . The simulation result shows that compared to the traditional DV-Hop
algorithm，the accuracy of the improved algorithm increased by about 30% in distance measurement as well as rose
approximately by 35% in relative localization precision
DV kagaishiya rinsho: Risk assessment [Domestic violence offenders intervention approach: Risk assessment] [In press]
No full textQuantitative IC-DV diagnostics
No full textThis MATLAB app is for quantitative diagnostics of degradation in lithium batteries. From the initial discharge curve and post-aged discharge curve, it calculates 1) loss of lithium inventory (LLI), 2) loss of active materials (LAM) in anode during lithiation, 3) LAM in anode during delithiation, 4) LAM in cathode during lithiation and 5) LAM in cathode during delithiation. To use the app, first run the peak locator app to identify peak positions and then input the peak positions in the IC-DV app. Our journal article manuscript can be downloaded here: http://hdl.handle.net/10044/1/92598Contact UsFor code inquiry: [email protected]; [email protected] author for the journal article and Principle Investigator of the project: [email protected] DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
Evaluation of turn-off dV/dt controllability and switching characteristics of 1.2 kV GaN polarisation superjunction heterostructure field-effect transistors
No full textJapanese Journal of Applied Physics
The Japan Society of Applied Physics, find out more
REGULAR PAPER • THE FOLLOWING ARTICLE ISOPEN ACCESS
Evaluation of turn-off dV/dt controllability and switching characteristics of 1.2 kV GaN polarisation superjunction heterostructure field-effect transistors
Alireza Sheikhan1, Sankara Narayanan Ekkanath Madathil1, Hiroji Kawai2, Shuichi Yagi2 and Hironobu Narui2
Published 5 July 2023 • © 2023 The Author(s). Published on behalf of The Japan Society of Applied Physics by IOP Publishing Ltd
Japanese Journal of Applied Physics, Volume 62, Number 6
Citation Alireza Sheikhan et al 2023 Jpn. J. Appl. Phys. 62 064502
DOI 10.35848/1347-4065/acd975
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1 Department of Electronic and Electrical Engineering, The University of Sheffield, Sheffield, United Kingdom
2 Powdec K.K. Oyama, Tochigi, Japan
ORCID iDs
Alireza Sheikhan https://orcid.org/0000-0002-2207-1593
Dates
Received 16 April 2023
Revised 18 May 2023
Accepted 26 May 2023
Published 5 July 2023
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Abstract
Gallium nitride (GaN) devices inherently offer many advantages over silicon power devices, including a higher operating frequency, lower on-state resistance and higher operating temperature capabilities, which can enable higher power density and more efficient power electronics. Turn-off dV/dt controllability plays a key role in determining common-mode voltage in electrical drives and traction inverter applications. The fast-switching edges of GaN can introduce challenges such as electromagnetic interference, premature insulation failure and high overshoot voltages. In this paper, the device working principle, characteristics and dV/dt controllability of 1.2 kV GaN polarisation superjunction (PSJ) heterostructure FETs (HFETs) are presented. The effect of gate driving parameters and load conditions on turn-off dV/dt are investigated. It is shown that in PSJ HFETs the dV/dt can be effectively controlled to as low as 1 kV μs−1 by controlling the gate, with a minimum increase in switching losses. These results are highly encouraging for the application of the devices in motor drives
Quantitative Incremental Capacity - Differential Voltage (IC-DV) diagnostics
No full textThis MATLAB app is for quantitative diagnostics of degradation in lithium batteries based on Incremental Capacity Analysis (ICA) and Differential Voltage Analysis (DVA). From the initial discharge curve and post-aged discharge curve, it calculates 1) loss of lithium inventory (LLI), 2) loss of active materials (LAM) in anode during lithiation, 3) LAM in anode during delithiation, 4) LAM in cathode during lithiation and 5) LAM in cathode during delithiation. To use the app, first run the peak locator app to identify peak positions and then input the peak positions in the IC-DV app. Our journal article manuscript can be downloaded here: http://hdl.handle.net/10044/1/92598Contact UsFor code inquiry: [email protected]; [email protected] author for the journal article and Principle Investigator of the project: [email protected] DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
Performance of triggered multi gap plasma closing switches filled with air, nitrogen and a nitrogen/oxygen mixture
No full textThis paper presents an experimental investigation into operation of a triggered, two electrode switch energised with a HV impulses superimposed over a DC charging voltage. A sphere-sphere topology with an electrode separation of 2 mm was DC energised to 6 kV, 7 kV and 8 kV and triggering impulses of varying dV/dt have been used. Breakdown voltage, time delay to breakdown and jitter have been measured for air, nitrogen and a 60% nitrogen/40% oxygen mixture. It is shown that higher dV/dt and higher DC energisation provide more stable and shorter time delays to breakdown
Accelerated image reconstruction by a combined dual-matrix dual-voxel approach
No full textToday, versatile emission computed tomography (VECTor) technology using dedicated high-energy collimation enables simultaneous positron emission tomography (PET) and single photon emission computed tomography (SPECT) down to 0.6 mm and 0.4 mm resolution in mice, respectively. We recently showed that for optimal resolution and quantitative accuracy of PET images the long tails of the 511 keV point spread functions (PSFs) need to be fully modelled during image reconstruction. This, however, leads to very time consuming reconstructions and thus significant acceleration in reconstruction speed is highly desirable. To this end we propose and validate a combined dual-matrix dual-voxel (DM-DV) approach: for the forward projection the slowly varying PSF tails are modelled on a three times rougher voxel grid than the central parts of the PSFs, while in the backprojection only parts of the PSF tails are included. DM-DV reconstruction is implemented in pixel-based ordered subsets expectation maximization (POSEM) and in a recently proposed accelerated pixel-based similarity-regulated ordered subsets expectation maximization (SROSEM). Both a visual assessment and a quantitative contrast-noise analysis confirm that images of a hot-rod phantom are practically identical when reconstructed with standard POSEM, DM-DV-POSEM or DM-DV-SROSEM. However, compared to POSEM, DM-DV-POSEM can reach the same contrast 5.0 times faster, while with DM-DV-SROSEM this acceleration factor increases to 11.5. Furthermore, mouse cardiac and bone images reconstructed with DM-DV-SROSEM are visually almost indistinguishable from POSEM reconstructed images but typically need an order of magnitude less reconstruction time.RST/Biomedical ImagingRST/Technici Poo
DV kagaishiya tono kakawari kata [Approaches to working with men who are violent and abusive to their partners?]
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