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Numerical three-dimensional modeling of earthen dam piping failure
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作者 Zhengang Wang 《Water Science and Engineering》 EI CAS CSCD 2024年第1期72-82,共11页
A physically-based numerical three-dimensional earthen dam piping failure model is developed for homogeneous and zoned soil dams.This model is an erosion model,coupled with force/moment equilibrium analyses.Orifice fl... A physically-based numerical three-dimensional earthen dam piping failure model is developed for homogeneous and zoned soil dams.This model is an erosion model,coupled with force/moment equilibrium analyses.Orifice flow and two-dimensional(2D)shallow water equations(SWE)are solved to simulate dam break flows at different breaching stages.Erosion rates of different soils with different construction compaction efforts are calculated using corresponding erosion formulae.The dam's real shape,soil properties,and surrounding area are programmed.Large outer 2D-SWE grids are used to control upstream and downstream hydraulic conditions and control the boundary conditions of orifice flow,and inner 2D-SWE flow is used to scour soil and perform force/moment equilibrium analyses.This model is validated using the European Commission IMPACT(Investigation of Extreme Flood Processes and Uncertainty)Test#5 in Norway,Teton Dam failure in Idaho,USA,and Quail Creek Dike failure in Utah,USA.All calculated peak outflows are within 10%errors of observed values.Simulation results show that,for a V-shaped dam like Teton Dam,a piping breach location at the abutment tends to result in a smaller peak breach outflow than the piping breach location at the dam's center;and if Teton Dam had broken from its center for internal erosion,a peak outflow of 117851 m'/s,which is 81%larger than the peak outflow of 65120 m3/s released from its right abutment,would have been released from Teton Dam.A lower piping inlet elevation tends to cause a faster/earlier piping breach than a higher piping inlet elevation. 展开更多
关键词 3D dam breach model 2D shallow water equations 3D slope stability analysis Piping failure Teton Dam Quail Creek Dike
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Application of Convolutional Neural Networks in Classification of GBM for Enhanced Prognosis
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作者 Rithik Samanthula 《Advances in Bioscience and Biotechnology》 CAS 2024年第2期91-99,共9页
The lethal brain tumor “Glioblastoma” has the propensity to grow over time. To improve patient outcomes, it is essential to classify GBM accurately and promptly in order to provide a focused and individualized treat... The lethal brain tumor “Glioblastoma” has the propensity to grow over time. To improve patient outcomes, it is essential to classify GBM accurately and promptly in order to provide a focused and individualized treatment plan. Despite this, deep learning methods, particularly Convolutional Neural Networks (CNNs), have demonstrated a high level of accuracy in a myriad of medical image analysis applications as a result of recent technical breakthroughs. The overall aim of the research is to investigate how CNNs can be used to classify GBMs using data from medical imaging, to improve prognosis precision and effectiveness. This research study will demonstrate a suggested methodology that makes use of the CNN architecture and is trained using a database of MRI pictures with this tumor. The constructed model will be assessed based on its overall performance. Extensive experiments and comparisons with conventional machine learning techniques and existing classification methods will also be made. It will be crucial to emphasize the possibility of early and accurate prediction in a clinical workflow because it can have a big impact on treatment planning and patient outcomes. The paramount objective is to not only address the classification challenge but also to outline a clear pathway towards enhancing prognosis precision and treatment effectiveness. 展开更多
关键词 GLIOBLASTOMA Machine Learning Artificial Intelligence Neural Networks Brain Tumor Cancer Tensorflow LAYERS CYTOARCHITECTURE Deep Learning Deep Neural Network Training Batches
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The application of open standards to enhance the interoperability of geoscience information 被引量:3
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作者 G.Percivall 《International Journal of Digital Earth》 SCIE 2010年第S01期14-30,共17页
We can adequately study broad global issues and policies only by taking geosciences into account.Our research and decision-making must share and make effective use of interdisciplinary data sources,models,and processe... We can adequately study broad global issues and policies only by taking geosciences into account.Our research and decision-making must share and make effective use of interdisciplinary data sources,models,and processes.Noninteroperability impedes sharing of data and computing resources.Standards from the Open Geospatial Consortium(OGC)and other organizations are the basis for successfully deploying a seamless,distributed information infrastructure for the geosciences.Several specifications now adopted by the OGC consensus process are the result of OGC interoperability initiatives.The OGC standards,deployment architectures,and interoperability initiatives are described showing how the OGC standards baseline has been developed and applies to the geosciences. 展开更多
关键词 GEOSCIENCES INTEROPERABILITY open standards Open Geospatial Consortium GEOINFORMATICS geospatial data integration Digital Earth architecture spatial data infrastructure data exchange models
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Observing the reconnection region in a transequatorial loop system 被引量:2
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作者 Rui Liu Tong-Jiang Wang +4 位作者 Jeongwoo Lee Guillermo Stenborg Chang Liu Sung-Hong Park Hai-Min Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2011年第10期1209-1228,共20页
A vertical current sheet is a crucial element in many flare/coronal mass ejection (CME) models. For the first time, Liu et al. reported a vertical current sheet directly imaged during the flare rising phase with the... A vertical current sheet is a crucial element in many flare/coronal mass ejection (CME) models. For the first time, Liu et al. reported a vertical current sheet directly imaged during the flare rising phase with the EUV Imaging Telescope (EIT) onboard the Solar and Heliospheric Observatory (SOHO). As a follow-up study, here we present the comprehensive analysis and detailed physical interpretation of the observation. The current sheet formed due to the gradual rise of a transequatorial loop system. As the loop legs approached each other, plasma flew at - 6 km s^-1 into a local area where a cusp-shaped flare loop subsequently formed and the current sheet was seen as a bright, collimated structure of global length (_〉 0.25 RQ) and macroscopic width ((5-10)× 10^3 km), extending from 50 Mm above the flaring loop to the border of the EIT field of view (FOV). The reconnection rate in terms of the Alfven Mach number is estimated to be only 0.005-0.009, albeit a halo CME was accelerated from - 400 km s- 1 to - 1300 km s- 1 within the coronagraph FOV. Drifting pulsating structures at metric frequencies were recorded during the impulsive phase, implying tearing of the current sheet in the high corona. A radio Type III burst occurred when the current sheet was clearly seen in EUV, indicative of accelerated electrons beam- ing upward from the upper tip of the current sheet. A cusp-shaped dimming region was observed to be located above the post-flare arcade during the decay phase in EIT; both the arcade and the dimming expanded with time. With the Coronal Diagnostic Spectrometer (CDS) aboard SOHO, a clear signature of chromospheric evaporation was seen during the decay phase, i.e., the cusp-shaped dimming region was associ- ated with plasma upflows detected with EUV hot emission lines, while the post-flare loop was associated with downflows detected with cold lines. This event provides a comprehensive view of the reconnection geometry and dynamics in the solar corona. 展开更多
关键词 SUN coronal mass ejections -- Sun flares -- Sun CORONA
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Modeling seasonal variations of ocean and sea ice circulation in the Beaufort and Chukchi Seas:A model-data fusion study
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作者 Wang Jia Kohei Mizobata +5 位作者 Hu Haoguo Jin Meibing Zhang Sheng Walter John-son Koji Shimada Moto Ikeda 《Chinese Journal of Polar Science》 2008年第2期168-184,共17页
A 3.8-kin Coupled Ice-Ocean Model (C1OM) was implemented to successfully reproduce many observed phenomena in the Beaufort and Chukchi seas, including the Bering-inflow-originated coastal current that splits into th... A 3.8-kin Coupled Ice-Ocean Model (C1OM) was implemented to successfully reproduce many observed phenomena in the Beaufort and Chukchi seas, including the Bering-inflow-originated coastal current that splits into three branches: Alaska Coastal Water (ACW) , Central Channel, and Herald Valley branches. Other modeled phenomena include the Beaufort Slope Current (BSC) , the Beaufort Gyre, the East Siberian Current ( ESC), mesoscale eddies, seasonal landfast ice, sea ice ridging, shear, and deformation. Many of these downscaling processes can only be captured by using a high-resolution CIOM, nested in a global climate model. The seasonal cycles for sea ice concentration, thickness, velocity, and other variables are well reproduced with Solid validation by satellite measurements. The seasonal cycles for upper ocean dynamics and thermodynamics are also well reproduced, which include the formation of the cold saline layer due to the injection of salt during sea ice formation, the BSC, and the subsurface upwelling in winter that brings up warm, even more saline Atlantic Water along the shelfbreak and shelf along the Beaufort coast. 展开更多
关键词 ocean and sea ice circulation Beaufort and Chukchi Seas model-data fusion.
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On the Model of Spectral Analysis of Optical Radiation
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作者 Surik Khudaverdyan Taron Hovhannisyan +4 位作者 Nazeli Meliqyan Narine Mehrabyan Stepan Tsaturyan Mane Khachatryan Ashok Vaseashta 《Journal of Electromagnetic Analysis and Applications》 2016年第2期23-32,共10页
A silicon photodiode structure was studied for the spectral analysis of optical radiation. The structure consists of oppositely-directed barriers. We developed a model of the electronic processes occurring in the stru... A silicon photodiode structure was studied for the spectral analysis of optical radiation. The structure consists of oppositely-directed barriers. We developed a model of the electronic processes occurring in the structure. The possibilities of the selection of separate waves from the integral flux of radiation, the wave absorption and the quantitative spectral analysis of the waves of the model for contaminated environment were investigated. An algorithm was developed for carrying out the spectral analysis without the preliminary calibration, and for promoting a possible creation of a new type of a portable semiconductor spectrophotometer. 展开更多
关键词 Spectral Analysis MONITORING PHOTOSENSITIVITY PHOTODIODE
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RESONANCE ENERGY AND PAULING BOND ORDER OF CONJUGATED HYDROCARBONS CONTAINING A FOUR-MEMBERED RING
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作者 杨丕鹏 《Chinese Science Bulletin》 SCIE EI CAS 1982年第9期961-965,共5页
There have been a few theoretical calculations of resonance energies (RE) and bond orders of conjugated hydrocarbons containing a four-membered ring. By using the structure-resonance theory Herndon calculated the RE f... There have been a few theoretical calculations of resonance energies (RE) and bond orders of conjugated hydrocarbons containing a four-membered ring. By using the structure-resonance theory Herndon calculated the RE for a wide range of conjugated hydrocarbons. Although the values calculated for a large number of compounds agree with the best SCF-MO results (the Dewar-de Llano RE), there are wide discrepancies in the case of compounds with a four-membered ring, and the 展开更多
关键词 CONJUGATED membered hydrocarbons AGREE MOIETY BONDS ORDERS Pauling substituted PAIRING
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