An Online Multistep-Forward Voltage-Prediction Approach Based on an LSTM-TD Model and KF Algorithm

Computer ◽  
2021 ◽  
Vol 54 (8) ◽  
pp. 56-65
Author(s):  
Ye Ni ◽  
Zhilong Xia ◽  
Fangtong Zhao ◽  
Chunrong Fang ◽  
Zhenyu Chen
Author(s):  
Bhanu P. Sood ◽  
Michael Pecht ◽  
John Miker ◽  
Tom Wanek

Abstract Schottky diodes are semiconductor switching devices with low forward voltage drops and very fast switching speeds. This paper provides an overview of the common failure modes in Schottky diodes and corresponding failure mechanisms associated with each failure mode. Results of material level evaluation on diodes and packages as well as manufacturing and assembly processes are analyzed to identify a set of possible failure sites with associated failure modes, mechanisms, and causes. A case study is then presented to illustrate the application of a systematic FMMEA methodology to the analysis of a specific failure in a Schottky diode package.


Author(s):  
J. Zimmer ◽  
D. Nielsen ◽  
T.A. Anderson ◽  
M. Schade ◽  
N. Saha ◽  
...  

Abstract The p-n junction of a GaAs light emitting diode is fabricated using liquid phase epitaxy (LPE). The junction is grown on a Si doped (~1018/cm3) GaAs substrate. Intermittent yield loss due to forward voltage snapback was observed. Historically, out of specification forward voltage (Vf) parameters have been correlated to abnormalities in the junction formation. Scanning electron (SEM) and optical microscopy of cleaved and stained samples revealed a continuous layer of material approximately 2.5 to 3.0 urn thick at the n-epi/substrate interface. Characterization of a defective wafer via secondary ion mass spectroscopy (SIMS) revealed an elevated concentration of O throughout the region containing the defect. X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES) data taken from a wafer prior to growth of the epi layers did not reveal any unusual oxidation or contamination. Extensive review of the processing data suggested LPE furnace pressure was the obvious source of variability. Processing wafers through the LPE furnace with a slight positive H2 gas pressure has greatly reduced the occurrence of this defect.


2017 ◽  
Vol 68 (4) ◽  
pp. 858-863
Author(s):  
Mihaela Oprea ◽  
Marius Olteanu ◽  
Radu Teodor Ianache

Fine particulate matter with a diameter less than 2.5 �m (i.e. PM2.5) is an air pollutant of special concern for urban areas due to its potential significant negative effects on human health, especially on children and elderly people. In order to reduce these effects, new tools based on PM2.5 monitoring infrastructures tailored to specific urban regions are needed by the local and regional environmental management systems for the provision of an expert support to decision makers in air quality planning for cities and also, to inform in real time the vulnerable population when PM2.5 related air pollution episodes occur. The paper focuses on urban air pollution early warning based on PM2.5 prediction. It describes the methodology used, the prediction approach, and the experimental system developed under the ROKIDAIR project for the analysis of PM2.5 air pollution level, health impact assessment and early warning of sensitive people in the Ploiesti city. The PM2.5 concentration evolution prediction is correlated with PM2.5 air pollution and health effects analysis, and the final result is processed by the ROKIDAIR Early Warning System (EWS) and sent as a message to the affected population via email or SMS. ROKIDAIR EWS is included in the ROKIDAIR decision support system.


2018 ◽  
Vol 27 (1) ◽  
pp. 53-70
Author(s):  
Ahmed Sedik ◽  
Turky Alotaiby ◽  
Heba El-Khobby ◽  
Mahmoud Atea ◽  
Saleh A. Alshebeili ◽  
...  

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 19550-19563 ◽  
Author(s):  
Ling Huang ◽  
Chang-Dong Wang ◽  
Hong-Yang Chao ◽  
Jian-Huang Lai ◽  
Philip S. Yu

2017 ◽  
Vol 21 (3) ◽  
pp. 1573-1591 ◽  
Author(s):  
Louise Crochemore ◽  
Maria-Helena Ramos ◽  
Florian Pappenberger ◽  
Charles Perrin

Abstract. Many fields, such as drought-risk assessment or reservoir management, can benefit from long-range streamflow forecasts. Climatology has long been used in long-range streamflow forecasting. Conditioning methods have been proposed to select or weight relevant historical time series from climatology. They are often based on general circulation model (GCM) outputs that are specific to the forecast date due to the initialisation of GCMs on current conditions. This study investigates the impact of conditioning methods on the performance of seasonal streamflow forecasts. Four conditioning statistics based on seasonal forecasts of cumulative precipitation and the standardised precipitation index were used to select relevant traces within historical streamflows and precipitation respectively. This resulted in eight conditioned streamflow forecast scenarios. These scenarios were compared to the climatology of historical streamflows, the ensemble streamflow prediction approach and the streamflow forecasts obtained from ECMWF System 4 precipitation forecasts. The impact of conditioning was assessed in terms of forecast sharpness (spread), reliability, overall performance and low-flow event detection. Results showed that conditioning past observations on seasonal precipitation indices generally improves forecast sharpness, but may reduce reliability, with respect to climatology. Conversely, conditioned ensembles were more reliable but less sharp than streamflow forecasts derived from System 4 precipitation. Forecast attributes from conditioned and unconditioned ensembles are illustrated for a case of drought-risk forecasting: the 2003 drought in France. In the case of low-flow forecasting, conditioning results in ensembles that can better assess weekly deficit volumes and durations over a wider range of lead times.


Author(s):  
Akihiro Tatsuta ◽  
Yasunori Shimazaki ◽  
Teppei Emura ◽  
Takuya Asada ◽  
Taichi Hamabe

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 421
Author(s):  
Chang-Hwan Lee ◽  
Iman Mansouri ◽  
Jaehoon Bae ◽  
Jaeho Ryu

A new type of composite voided slab, the TUBEDECK (TD), which utilizes the structural function of profiled steel decks, has recently been proposed. Previous studies have confirmed that the flexural strength of TD slabs can be calculated based on the full composite contribution of the steel deck, but for long-span flexural members, the deflection serviceability requirement is often dominant. Herein, we derived a novel deflection prediction approach using the results of flexural tests on slab specimens, focusing on TD slabs. First, deflection prediction based on modifications of the current code was proposed. Results revealed that TD slabs exhibited smaller long-term deflections and at least 10% longer maximum span lengths than solid slabs, indicating their greater efficiency. Second, a novel rational method was derived for predicting deflections without computing the effective moment of inertia. The ultimate deflections predicted by the proposed method correlated closely with the deflection under maximum bending moments. To calculate immediate deflections, variation functions for the concrete strain at the extreme compression fiber and neutral axis depth were assumed with predictions in good agreement with experiments. The proposed procedure has important implications in highlighting a new perspective on the deflection prediction of reinforced concrete and composite flexural members.


Sign in / Sign up

Export Citation Format

Share Document