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Articles 69631 - 69660 of 302480

Full-Text Articles in Physical Sciences and Mathematics

Making A Bee-Line For Food With Octopamine, Lauren E. Nadler Sep 2020

Making A Bee-Line For Food With Octopamine, Lauren E. Nadler

Marine & Environmental Sciences Faculty Articles

No abstract provided.


Seasonal Movements And Habitat Use Of Juvenile Smooth Hammerhead Sharks In The Western North Atlantic Ocean And Significance For Management, Ryan K. Logan, Jeremy Vaudo, Lara L. Sousa, Mark Sampson, Bradley M. Wetherbee, Mahmood S. Shivji Sep 2020

Seasonal Movements And Habitat Use Of Juvenile Smooth Hammerhead Sharks In The Western North Atlantic Ocean And Significance For Management, Ryan K. Logan, Jeremy Vaudo, Lara L. Sousa, Mark Sampson, Bradley M. Wetherbee, Mahmood S. Shivji

Marine & Environmental Sciences Faculty Articles

Upper trophic level predators dramatically impacted by fisheries include the large-bodied hammerhead sharks, which have become species of conservation concern worldwide. Implementing spatial management for conservation of hammerhead populations requires knowledge of temporal distribution patterns and habitat use, identification of essential habitat for protection, and quantification of interactions with human activities. There is little such information for the smooth hammerhead shark, Sphyrna zygaena. We used fin-mounted satellite tags to examine the movements and habitat use of juvenile smooth hammerheads, a demographic segment particularly threatened by exploitation. Six sharks were tagged off the US mid-Atlantic and tracked for 49–441 days …


Is The Transit Industry Prepared For The Cyber Revolution? Policy Recommendations To Enhance Surface Transit Cyber Preparedness, Scott Belcher, Terri Belcher, Eric Greenwald, Brandon Thomas Sep 2020

Is The Transit Industry Prepared For The Cyber Revolution? Policy Recommendations To Enhance Surface Transit Cyber Preparedness, Scott Belcher, Terri Belcher, Eric Greenwald, Brandon Thomas

Mineta Transportation Institute

The intent of this study is to assess the readiness, resourcing, and structure of public transit agencies to identify, protect from, detect, respond to, and recover from cybersecurity vulnerabilities and threats. Given the multitude of connected devices already in use by the transit industry and the vast amount of data generated (with more coming online soon), the transit industry is vulnerable to malicious cyber-attack and other cybersecurity-related threats. This study reviews the state of best cybersecurity practices in public surface transit; outlines U.S. public surface transit operators’ cybersecurity operations; assesses U.S. policy on cybersecurity in public surface transportation; and provides …


Slab Dehydration And Mantle Upwelling In The Vicinity Of The Sumatra Subduction Zone: Evidence From Receiver Function Imaging Of Mantle Transition Zone Discontinuities, Fansheng Kong, Stephen S. Gao, Kelly H. Liu, Weiwei Ding, Jiabiao Li Sep 2020

Slab Dehydration And Mantle Upwelling In The Vicinity Of The Sumatra Subduction Zone: Evidence From Receiver Function Imaging Of Mantle Transition Zone Discontinuities, Fansheng Kong, Stephen S. Gao, Kelly H. Liu, Weiwei Ding, Jiabiao Li

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

A total of 10,586 P-to-S radial receiver functions recorded by 64 broadband seismic stations were utilized to image the 410 and 660 km discontinuities (d410 and d660, respectively) bordering the mantle transition zone (MTZ) beneath the Sumatra Island, the Malay Peninsula, and the western margin of the South China Sea. The d410 and d660 were imaged by stacking receiver functions in successive circular bins with a radius of 1°, after moveout corrections based on the 1-D IASP91 Earth model. The resulting apparent depths of the discontinuities exhibit significant and spatially systematic variations. The apparent depths of the d410 and d660 …


Yellowstone National Park - Feat Snowmobile Measurements, University Of Denver Sep 2020

Design Of Iaas Mode “Cloud Training” System, Zhijia Chen, Yuanchang Zhu, Yanqiang Di, Shaochong Feng Sep 2020

Design Of Iaas Mode “Cloud Training” System, Zhijia Chen, Yuanchang Zhu, Yanqiang Di, Shaochong Feng

Journal of System Simulation

Abstract: There are some problems in equipment web simulating training, including poor sense of reality, low efficiency of training and high difficulty of management. To solve those problems, Infrastructure as a Service mode “cloud training” was proposed. The architecture and operation flow were explained in detail and the key technologies of “cloud training” were focused on. By GPU virtualization technology, the problem of client 3D image processing capability was solved. According to the characters of simulation training, the user requirement model was established. Fuzzy algorithm was introduced to realize resource dynamic scheduling. To assure the stability and reliability, …


Optimization Design For A New Type Throttle Valve Of Managed Pressure Drilling Based On Response Surface Methodology, Guorong Wang, Chu Fei, Hongkang Fan, Siyu Tao, Zhu Hao, Jiang Long Sep 2020

Optimization Design For A New Type Throttle Valve Of Managed Pressure Drilling Based On Response Surface Methodology, Guorong Wang, Chu Fei, Hongkang Fan, Siyu Tao, Zhu Hao, Jiang Long

Journal of System Simulation

Abstract: The Kriging response surface of single parameter and double parameters versus mass loss of valve spool about bonnet length, bonnet external radius and chamber inner radius of a new type throttle valve used in Managed Pressure Drilling was carried out by using CFX and ANSYS-Design Exploration. The results show that these dimensions have significant influence on erosion mass loss of valve spool. In order to improve the anti-erosion ability of the spool and enhance the service life of the whole valve, the multi-objective genetic algorithm was used for dimensional optimization design of the mentioned variables. After optimization …


Call To Action: Sars-Cov-2 And Cerebrovascular Disorders (Cascade), Shahram Abootalebi, Benjamin M. Aertker, Mohammad Sobhan Andalibi, Negar Asdaghi, Ozlem Aykac, M. Reza Azarpazhooh, M. Cecilia Bahit, Kristian Barlinn, Hamidon Basri, Reza Bavarsad Shahripour, Anna Bersano, Jose Biller, Afshin Borhani-Haghighi, Robert D. Brown, Bruce Cv Campbell, Salvador Cruz-Flores, Deidre Anne De Silva, Mario Di Napoli, Afshin A. Divani, Randall C. Edgell, Johanna T. Fifi, Abdoreza Ghoreishi, Teruyuki Hirano, Keun Sik Hong, Chung Y. Hsu, Josephine F. Huang, Manabu Inoue, Amanda L. Jagolino, Moira Kapral, Hoo Fan Kee, Zafer Keser, Rakesh Khatri Sep 2020

Call To Action: Sars-Cov-2 And Cerebrovascular Disorders (Cascade), Shahram Abootalebi, Benjamin M. Aertker, Mohammad Sobhan Andalibi, Negar Asdaghi, Ozlem Aykac, M. Reza Azarpazhooh, M. Cecilia Bahit, Kristian Barlinn, Hamidon Basri, Reza Bavarsad Shahripour, Anna Bersano, Jose Biller, Afshin Borhani-Haghighi, Robert D. Brown, Bruce Cv Campbell, Salvador Cruz-Flores, Deidre Anne De Silva, Mario Di Napoli, Afshin A. Divani, Randall C. Edgell, Johanna T. Fifi, Abdoreza Ghoreishi, Teruyuki Hirano, Keun Sik Hong, Chung Y. Hsu, Josephine F. Huang, Manabu Inoue, Amanda L. Jagolino, Moira Kapral, Hoo Fan Kee, Zafer Keser, Rakesh Khatri

Epidemiology and Biostatistics Publications

Background and purpose: The novel severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2), now named coronavirus disease 2019 (COVID-19), may change the risk of stroke through an enhanced systemic inflammatory response, hypercoagulable state, and endothelial damage in the cerebrovascular system. Moreover, due to the current pandemic, some countries have prioritized health resources towards COVID-19 management, making it more challenging to appropriately care for other potentially disabling and fatal diseases such as stroke. The aim of this study is to identify and describe changes in stroke epidemiological trends before, during, and after the COVID-19 pandemic. Methods: This is an international, multicenter, hospital-based …


Late-Holocene Shoreline Responses To Competing Shelf, Bay, And Beach Accommodation Spaces Under Conditions Of Relative Sea Level Change, And The Potential For Future Catastrophic Beach Retreat In The Columbia River Littoral Cell, Washington And Oregon, Usa, Curt D. Peterson, Tamara C. Linde, Sandy Vanderburgh Sep 2020

Late-Holocene Shoreline Responses To Competing Shelf, Bay, And Beach Accommodation Spaces Under Conditions Of Relative Sea Level Change, And The Potential For Future Catastrophic Beach Retreat In The Columbia River Littoral Cell, Washington And Oregon, Usa, Curt D. Peterson, Tamara C. Linde, Sandy Vanderburgh

Geology Faculty Publications and Presentations

The Columbia River Littoral Cell (CRLC) (160 km in length) provides opportunities to compare competing accommodation space relations under different conditions of relative sea level change. The CRLC system includes abundant littoral sand supply from the large Columbia River, late-Holocene prograded beach plains and barrier spits (0.5–5 km in width), two large marine-dominated estuaries (Willapa Bay and Grays Harbor), and a high-wave-energy inner-shelf. Littoral sand accumulation rates in prograded beach plains and barrier deposits are based on paleo-shoreline positions that are dated by great-earthquake catastrophic beach retreat scarps (n = 10) from 0.3 to 5.0 ka. The retreat scarp timelines …


Benefits And Tradeoffs Of Reduced Tillage And Manure Application Methods In A Zea Mays Silage System, Kyle M. Dittmer, Heather M. Darby, Tyler R. Goeschel, E. Carol Adair Sep 2020

Benefits And Tradeoffs Of Reduced Tillage And Manure Application Methods In A Zea Mays Silage System, Kyle M. Dittmer, Heather M. Darby, Tyler R. Goeschel, E. Carol Adair

College of Agriculture and Life Sciences Faculty Publications

A critical question is whether there are agricultural management practices that can attain the multiple management goals of increasing yields, preventing nutrient losses, and suppressing greenhouse gas (GHG) emissions. No-till and manure application methods, such as manure injection, can enhance nutrient retention, but both may also enhance emissions of nitrous oxide (N2O), a powerful GHG. We assessed differences in soil N2O and carbon dioxide (CO2) emissions, nitrate and ammonium retention, and crop yield and protein content under combinations of vertical-till, no-till, manure injection, and manure broadcast without incorporation in a corn (Zea mays L.) silage system. During the growing seasons …


A Genetic Algorithm To Minimise Number Of Vehicles In An Electric Vehicle Routing Problem, Kiian Leong Bertran Queck, Hoong Chuin Lau Sep 2020

A Genetic Algorithm To Minimise Number Of Vehicles In An Electric Vehicle Routing Problem, Kiian Leong Bertran Queck, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

Electric Vehicles (EVs) and charging infrastructure are starting to become commonplace in major cities around the world. For logistics providers to adopt an EV fleet, there are many factors up for consideration, such as route planning for EVs with limited travel range as well as long-term planning of fleet size. In this paper, we present a genetic algorithm to perform route planning that minimises the number of vehicles required. Specifically, we discuss the challenges on the violations of constraints in the EV routing problem (EVRP) arising from applying genetic algorithm operators. To overcome the challenges, techniques specific to addressing the …


Towards Interpreting Recurrent Neural Networks Through Probabilistic Abstraction, Guoliang Dong, Jingyi Wang, Jun Sun, Yang Zhang, Xinyu Wang, Ting Dai, Jin Song Dong, Xingen Wang Sep 2020

Towards Interpreting Recurrent Neural Networks Through Probabilistic Abstraction, Guoliang Dong, Jingyi Wang, Jun Sun, Yang Zhang, Xinyu Wang, Ting Dai, Jin Song Dong, Xingen Wang

Research Collection School Of Computing and Information Systems

Neural networks are becoming a popular tool for solving many realworld problems such as object recognition and machine translation, thanks to its exceptional performance as an end-to-end solution. However, neural networks are complex black-box models, which hinders humans from interpreting and consequently trusting them in making critical decisions. Towards interpreting neural networks, several approaches have been proposed to extract simple deterministic models from neural networks. The results are not encouraging (e.g., low accuracy and limited scalability), fundamentally due to the limited expressiveness of such simple models.In this work, we propose an approach to extract probabilistic automata for interpreting an important …


Top–Down Control On Eruptive Style At Masaya Volcano Inferred From Melt Composition, Lisa Hlinka Sep 2020

Top–Down Control On Eruptive Style At Masaya Volcano Inferred From Melt Composition, Lisa Hlinka

Student Theses

Highly explosive, Plinian-type eruptions of basaltic magma are enigmatic because basaltic melts have lower viscosities than more silicic melts which have traditionally been considered essential for such explosive eruption style. Masaya volcano, Nicaragua, is one of the few basaltic volcanoes to have generated a wide range of eruptive styles, from effusive lava lake activity to voluminous Plinian fall deposits. This volcano thus offers a unique case study to better constrain ideas on basaltic eruption style controls.

We analyze olivine-, plagioclase- and clinopyroxene-hosted melt inclusions as well as matrix glasses from lava lake (LL) ejecta and two Plinian tephra deposits—the 2.1 …


Valid Time Rdf, Hsien-Tseng Wang Sep 2020

Valid Time Rdf, Hsien-Tseng Wang

Dissertations, Theses, and Capstone Projects

The Semantic Web aims at building a foundation of semantic-based data models and languages for not only manipulating data and knowledge, but also supporting decision making by machines. Naturally, time-varying data and knowledge are required in Semantic Web applications to incorporate time and further reason about it. However, the original specifications of Resource Description Framework (RDF) and Web Ontology Language (OWL) do not include constructs for handling time-varying data and knowledge. For simplicity, RDF model is confined to binary predicates, hence some form of reification is needed to represent higher-arity predicates. To this date, there are many proposals extending RDF …


A Data Exploration Of Jeopardy! From 1984 To The Present, Brian S. Hamilton Sep 2020

A Data Exploration Of Jeopardy! From 1984 To The Present, Brian S. Hamilton

Dissertations, Theses, and Capstone Projects

The gameshow Jeopardy! has been around in its current iteration—hosted by Alex Trebek—since 1984. During this time, it has accumulated data on clues, contestants, and possible strategies on how to win. Using a crowd-sourced archive called J! Archive, this project seeks to find trends in the topics that the game covers and take a deeper look into the performance of its contestants. It employs topic modeling, a text-analysis method, to organize the hundreds of thousands of archived clues and statistical analysis to rate the performance of contestants by gender. Using web-based visualization tools, the data is shown in an …


Jmasm 54: A Comparison Of Four Different Estimation Approaches For Prognostic Survival Oral Cancer Model, Wan Muhamad Amir, Muhammad Azeem, Masitah Hayati Harun, Zalila Ali, Mohamad Shafiq Sep 2020

Jmasm 54: A Comparison Of Four Different Estimation Approaches For Prognostic Survival Oral Cancer Model, Wan Muhamad Amir, Muhammad Azeem, Masitah Hayati Harun, Zalila Ali, Mohamad Shafiq

Journal of Modern Applied Statistical Methods

Four types of estimation approaches for prognostic survival oral cancer model building are considered via a SAS algorithm: Efron’s Method, Exact Method, Breslow’s Method, and Discrete Method. Each method is illustrated separately and compared according to their coefficient parameter. An approach is considered by adding a bootstrapping technique for each handling ties method and a complete SAS algorithm is supplied for each proposed method, including methods for handling ties.


Bots And Humans On Social Media, Lale Madahali Sep 2020

Bots And Humans On Social Media, Lale Madahali

Interdisciplinary Informatics Faculty Proceedings & Presentations

Social networks are an important part of today’s life. They are used for entertainment, getting the news, advertisements, and branding for businesses and individuals alike. Research shows that automated accounts, also known as bots, contribute to the content spread on social media allowing the the environment pollution and public opinion manipulation. This research aims at investigating bots’ behavior on Twitter and examine how different and similar they are compared to humans. I will investigate their underlying network, whether it is an information network or social network. In the second step, I attempt to answer whether they follow the structure of …


Allostery In Oligomeric Receptor Models, Gregory D. Conradi Smith Sep 2020

Allostery In Oligomeric Receptor Models, Gregory D. Conradi Smith

Arts & Sciences Articles

We show how equilibrium binding curves of receptor homodimers can be expressed as rational polynomial functions of the equilibrium binding curves of the constituent monomers, without approximation and without assuming independence of receptor monomers. Using a distinguished spanning tree construction for reduced graph powers, the method properly accounts for thermodynamic constraints and allosteric interactions between receptor monomers (i.e. conformational coupling). The method is completely general; it begins with an arbitrary undirected graph representing the topology of a monomer state-transition diagram and ends with an algebraic expression for the equilibrium binding curve of a receptor oligomer composed of two or more …


Reducing A Class Of Two-Dimensional Integrals To One-Dimension With An Application To Gaussian Transforms, Jack C. Straton Sep 2020

Reducing A Class Of Two-Dimensional Integrals To One-Dimension With An Application To Gaussian Transforms, Jack C. Straton

Physics Faculty Publications and Presentations

Quantum theory is awash in multidimensional integrals that contain exponentials in the integration variables, their inverses, and inverse polynomials of those variables. The present paper introduces a means to reduce pairs of such integrals to one dimension when the integrand contains powers multiplied by an arbitrary function of xy/ (x + y) multiplying various combinations of exponentials. In some cases these exponentials arise directly from transition-amplitudes involving products of plane waves, hydrogenic wave functions, and Yukawa and/or Coulomb potentials. In other cases these exponentials arise from Gaussian transforms of such functions.


College Of Natural Sciences Newsletter, September 2020, College Of Natural Sciences Sep 2020

College Of Natural Sciences Newsletter, September 2020, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Issue 1. Volume 8

Contents:

Dean’s Update P.1
Awards & Recognition P.2
Interest in Science | Competitions P.3
Open PRAIRIE | ODFS Recap P.4
ODFS Recap | Research Spotlight P.5
Spring 2020 Dean’s List P.6-7


Analyzing Sensor-Based Individual And Population Behavior Patterns Via Inverse Reinforcement Learning, Beiyu Lin, Diane J. Cook Sep 2020

Analyzing Sensor-Based Individual And Population Behavior Patterns Via Inverse Reinforcement Learning, Beiyu Lin, Diane J. Cook

Computer Science Faculty Publications and Presentations

Digital markers of behavior can be continuously created, in everyday settings, using time series data collected by ambient sensors. The goal of this work was to perform individual- and population-level behavior analysis from such time series sensor data. In this paper, we introduce a novel algorithm-Resident Relative Entropy-Inverse Reinforcement Learning (RRE-IRL)-to perform an analysis of a single smart home resident or a group of residents, using inverse reinforcement learning. By employing this method, we learnt an individual's behavioral routine preferences. We then analyzed daily routines for an individual and for eight smart home residents grouped by health diagnoses. We observed …


Control Of Molecular Energetics And Transport Via Strong Light-Matter Interaction, Rong Wu Sep 2020

Control Of Molecular Energetics And Transport Via Strong Light-Matter Interaction, Rong Wu

Dissertations, Theses, and Capstone Projects

Strong light-matter coupling in excitonic systems results in the formation of half-light half-matter quasiparticles called exciton polaritons. These hybrid quasiparticles take on the best of both systems, namely, the long-range propagation and coherence arising from the photonic component and the nonlinear interaction from the excitonic component. We develop methods for making high quality factor cavities and investigate the potential applications of these strongly coupled states arising specifically in organic molecular systems.

In the first project we investigate the potential of organic dye molecules to undergo condensation in an optical cavity at room temperature. The second study involves the use of …


Matrix Low Rank Approximation At Sublinear Cost, Qi Luan Sep 2020

Matrix Low Rank Approximation At Sublinear Cost, Qi Luan

Dissertations, Theses, and Capstone Projects

A matrix algorithm runs at sublinear cost if the number of arithmetic operations involved is far fewer than the number of entries of the input matrix. Such algorithms are especially crucial for applications in the field of Big Data, where input matrices are so immense that one can only store a fraction of the entire matrix in memory of modern machines. Typically, such matrices admit Low Rank Approximation (LRA) that can be stored and processed at sublinear cost. Can we compute LRA at sublinear cost? Our counter example presented in Appendix C shows that no sublinear cost algorithm can compute …


Barriers And Facilitators In Implementing A Pilot, Pragmatic, Telemedicine-Delivered Healthy Lifestyle Program For Obesity Management In A Rural, Academic Obesity Clinic, John A. Batsis, Auden C. Mcclure, Aaron B. Weintraub, Diane Sette, Sivan Rotenberg, Courtney J. Stevens, Diane Gilbert-Diamond, David Kotz, Stephen Bartels, Summer B. Cook, Richard I. Rothstein Sep 2020

Barriers And Facilitators In Implementing A Pilot, Pragmatic, Telemedicine-Delivered Healthy Lifestyle Program For Obesity Management In A Rural, Academic Obesity Clinic, John A. Batsis, Auden C. Mcclure, Aaron B. Weintraub, Diane Sette, Sivan Rotenberg, Courtney J. Stevens, Diane Gilbert-Diamond, David Kotz, Stephen Bartels, Summer B. Cook, Richard I. Rothstein

Dartmouth Scholarship

Few evidence-based strategies are specifically tailored for disparity populations such as rural adults. Two-way video-conferencing using telemedicine can potentially surmount geographic barriers that impede participation in high-intensity treatment programs offering frequent visits to clinic facilities. We aimed to understand barriers and facilitators of implementing a telemedicine-delivered tertiary-care, rural academic weight-loss program for the management of obesity.


Low Complexity Method Based On Fc-Ce-Slm For Papr Reduction In Ofdm System, Ce Ji, Lijuan Wang Sep 2020

Low Complexity Method Based On Fc-Ce-Slm For Papr Reduction In Ofdm System, Ce Ji, Lijuan Wang

Journal of System Simulation

Abstract: Selected mapping (SLM) algorithm uses Cross Entropy (CE) algorithm to get the most optimal sign sequence so that SLM can make the effect of PAPR Reduction achieve optimum. However, it needs too many times iterative computations, so it will increase the complexity of the algorithm. In order to solve this problem, a fast convergence factor in the CE-SLM algorithm was introduced to make the sampling probability converge to 0 or 1 quickly in the system, which reduced the iterative times of getting the optimal sign sequence. Computer simulation results show that the approved algorithm reduces the iterative times of …


Three-Dimensional Fuzzy Control Of Catheter Robotic In Endovascular Master-Slave Interventional Surgery, Ximei Zhao, Jiankang You, Liu Hao, Hongyi Li Sep 2020

Three-Dimensional Fuzzy Control Of Catheter Robotic In Endovascular Master-Slave Interventional Surgery, Ximei Zhao, Jiankang You, Liu Hao, Hongyi Li

Journal of System Simulation

Abstract: In minimally invasive endovascular interventional surgery, catheter was vulnerable to be interfered by uncertain factors such as heartbeat and breathing of patients during catheter robot of slave side conveyed catheter. In order to retrain impact on catheter transport of these factors and realize that slave side of catheter robot system tracked control command of master side accurately and quickly, kinematic model of catheter distal bending section was established, and catheter robot system based on three-dimensional fuzzy controller was designed. Three-dimensional fuzzy controller that introduced the function of rate of error change on the basis of two-dimensional fuzzy controller …


Decoupling Control Research Of Neutral Buoyancy Plant Based On Cmac, Peilong Li, Wang Lei, Gaofeng Li Sep 2020

Decoupling Control Research Of Neutral Buoyancy Plant Based On Cmac, Peilong Li, Wang Lei, Gaofeng Li

Journal of System Simulation

Abstract: To solve the control problem of neutral buoyancy plant, a dynamic decoupling and multidimensional compound control agorithm was proposed. By the plant force situation analysis, its six degree motion control model was developed. Then a dynamic decoupling neural network was designed with the merit of adaptation of the dynamic changing coupling situation. CMAC (Cerebellar Model Articulation Controller) and PID compound control was adopted in single channel control, whose advantage is that it combines the rapidity of CMAC feedforward control and anti-interference of PID feedback control. MATLAB simulation results show that the algorithm can control the plant's position and posture …


Research Of Noise Mitigation Method Based On Dspwvd-Tfpf In Communication System, Lingdong Su, Mingyue Zhai Sep 2020

Research Of Noise Mitigation Method Based On Dspwvd-Tfpf In Communication System, Lingdong Su, Mingyue Zhai

Journal of System Simulation

Abstract: In the case of low SNR, the quality of the communication system will be decreased and the traditional TFPF on time-frequency clustering and noise suppression will descend. In order to overcome these, a new family of TF distribution, namely, the joint directionally smoothing Wigner-Ville distribution was presented to achieve instantaneous frequency estimation. This new TF distributions is based on the definition of the directionally smoothed pseudo Wigner-Ville distribution (DSPWVD) and point wise adaptive weight averaging of a bank of DSPWVD with different directions. The simulation shows that at low SNR, compared to traditional TFPF, DSPWVD-TFPF algorithm can better …


Construction Of Virtual Atmospheric Environment Based On Mm5 And Sedris, Lianlei Lin, Ding Wei Sep 2020

Construction Of Virtual Atmospheric Environment Based On Mm5 And Sedris, Lianlei Lin, Ding Wei

Journal of System Simulation

Abstract: The new virtual test for virtual atmosphere environment puts forward higher requirements, such as providing complex atmospheric environment which includes a variety of atmospheric parameters and improving usability and reusability of atmospheric environment data. A method to construct virtual atmospheric environment based on MM5 and SEDRIS was proposed which met the above demands. The original data of complex atmospheric environment in any region and scale was generated by using MM5 model. According to the characteristics as well as the dynamic relationship between time and space of grid of atmospheric data, SEDRIS was selected to regulate appropriate DRM class, SRF …


Large Eddy Simulation Of Effect Of Geometric Parameters On Low Pressure Of Turbulent Flow Over Gate Slot, Shihua He, Lixiang Zhang Sep 2020

Large Eddy Simulation Of Effect Of Geometric Parameters On Low Pressure Of Turbulent Flow Over Gate Slot, Shihua He, Lixiang Zhang

Journal of System Simulation

Abstract: The turbulent flow over the hydraulic plane gate slot was studied using large eddy simulation method. The effects of geometric parameters including width-to-depth ratio, stagger ratio, slope ratio and fillet ratio on hydraulic characteristics within and near the gate slot were simulated systematically. According to the vulnerable cavitation locations of the flow over the slot, the pressure distributions in swirl area and the separation zone at the rear of downstream corner of the slot were investigated emphatically. The results show that the effects of width-to-depth ratios and stagger ratios on the pressure distribution of the flow are significantly. …