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Articles 70261 - 70290 of 302581

Full-Text Articles in Physical Sciences and Mathematics

High-Frequency Data Reveal Differential Dissolved And Suspended Solids Behavior From A Mixed Restored Prairie And Agricultural Catchment, Andrew Miller, Ashlee L. Dere, Tracy Coleman Aug 2020

High-Frequency Data Reveal Differential Dissolved And Suspended Solids Behavior From A Mixed Restored Prairie And Agricultural Catchment, Andrew Miller, Ashlee L. Dere, Tracy Coleman

Chemistry Faculty Publications

Quantifying temporal variability and fluxes within hydrologic catchments is critical to understanding the underlying chemical and physical processes leading to material transport. Measuring variability and fluxes requires sampling at time scales similar to the time scale of process occurrence. This demand has led to the development of automated sampling systems designed to sample at high frequencies, on the order of minutes. While widely deployed in a variety of systems, we installed two high-frequency sampling devices in a single drainage comprised of restored prairie and agricultural land uses in temperate Eastern Nebraska. The sampling systems determined flow rate, conductivity, and turbidity …

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Numerical Model Of A Radio Frequency Ion Source For Fusion Plasma Using Particle-In-Cell And Finite Difference Time Domain, Augustin L. Griswold Aug 2020

Numerical Model Of A Radio Frequency Ion Source For Fusion Plasma Using Particle-In-Cell And Finite Difference Time Domain, Augustin L. Griswold

University Honors Theses

Radio frequency (RF) plasma sources are common tool for application and study, and of particular interest for inertial electrostatic (IEC) fusion. Computational analysis is often carried out using particle in cell (PIC) methods or finite difference time domain (FDTD). However, a more holistic analysis is necessary as the particle distribution is highly dependant on the fields created by the plasma source. Herein, an analysis of a particular planar RF electrode with deuterium gas is provided which covers the fields and the particle behaviour using first FDTD then PIC. Further applications are discussed as well as further directions for this study.

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Short And Long Term Effects Of Lime And Gypsum Applications On Acid Soils In A Water-Limited Environment: 1. Grain Yield Response And Nutrient Concentration, Geoff Anderson, Shahab Pathan, James Easton, David Hall, Rajesh Sharma Aug 2020

Short And Long Term Effects Of Lime And Gypsum Applications On Acid Soils In A Water-Limited Environment: 1. Grain Yield Response And Nutrient Concentration, Geoff Anderson, Shahab Pathan, James Easton, David Hall, Rajesh Sharma

Grain and Other Field Crops Research Articles

Surface (0–10 cm) and subsoil (soil layers below 10 cm) acidity and resulting aluminum (Al) toxicity reduce crop grain yields. In South Western Australia (SWA), these constraints affect 14.2 million hectares or 53% of the agricultural area. Both lime (L, CaCO3) and gypsum (G, CaSO4) application can decrease the toxic effect of Al, leading to an increase in crop grain yields. Within the region, it is unclear if G alone or the combined use of L and G has a role in alleviating soil acidity in SWA, due to low sulfate S (SO4–S) sorption properties of the soil. We present …

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High Ethanol Concentration (77 G/L) Of Industrial Hemp Biomass Achieved Through Optimizing The Relationship Between Ethanol Yield/Concentration And Solid Loading, Jikai Zhao, Youjie Xu, Weiqun Wang, Jason Griffin, Donghai Wang Aug 2020

High Ethanol Concentration (77 G/L) Of Industrial Hemp Biomass Achieved Through Optimizing The Relationship Between Ethanol Yield/Concentration And Solid Loading, Jikai Zhao, Youjie Xu, Weiqun Wang, Jason Griffin, Donghai Wang

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

In this study, the relationships between ethanol yield/concentration and solid loading (6–21%) were investigated to enhance ethanol titer and avoid a random choice of solid loading for simultaneous saccharification and fermentation (SSF). Alkali-pretreated hemp biomass was used for SSF in four scenarios including Case I: 30 filter paper unit (FPU)-cellulase and 140 fungal xylanase unit (FXU)-hemicellulase/g-solid; Case II: 40 FPU-cellulase and 140 FXU-hemicellulase/g-solid; Case III: 30 FPU-cellulase and 140 FXU-hemicellulase/g-solid with 1% Tween80; and Case IV: 30 FPU-cellulase and 140 FXU-hemicellulase/g-solid with particle size reduction (R2 = 0.76–0.93) and quadratic (R2 = 0.96–0.99) correlation with solid loading (6–21%), …

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N‐P‐K Balance In A Milk Production System On A C. Nlemfuensis Grassland And A Biomass Bank Of P. Purpureum Ct‐115 Clone, Gustavo Crespo, Idalmis Rodríguez, Omar Martínez Aug 2020

N‐P‐K Balance In A Milk Production System On A C. Nlemfuensis Grassland And A Biomass Bank Of P. Purpureum Ct‐115 Clone, Gustavo Crespo, Idalmis Rodríguez, Omar Martínez

IGC Proceedings (1993-2023)

No abstract provided.

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Effect Of Silicon Application On Water Use Efficiency Of Alfalfa Plants, Zhenggang Guo, Huixia Liu, Suomin Wang Aug 2020

Effect Of Silicon Application On Water Use Efficiency Of Alfalfa Plants, Zhenggang Guo, Huixia Liu, Suomin Wang

IGC Proceedings (1993-2023)

No abstract provided.

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Estimation Of Plant N, P And K Contents In The Inner Mongolia Steppe Using Spad Value, Wa Gao, En Wu, N. Ishikawa, Qi Xing, M. Goto Aug 2020

Estimation Of Plant N, P And K Contents In The Inner Mongolia Steppe Using Spad Value, Wa Gao, En Wu, N. Ishikawa, Qi Xing, M. Goto

IGC Proceedings (1993-2023)

No abstract provided.

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Biological Absorbing Capacity Of Nutrient Elements By Some Temperate Tame Grasses, Zhanchi Du, J. W. Fan, H. P. Zhang Aug 2020

Biological Absorbing Capacity Of Nutrient Elements By Some Temperate Tame Grasses, Zhanchi Du, J. W. Fan, H. P. Zhang

IGC Proceedings (1993-2023)

No abstract provided.

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General Product Formula Of Multiple Integrals Of Lévy Process, Nishant Agrawal, Yaozhong Hu, Neha Sharma Aug 2020

General Product Formula Of Multiple Integrals Of Lévy Process, Nishant Agrawal, Yaozhong Hu, Neha Sharma

Journal of Stochastic Analysis

No abstract provided.

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Continuous Dependence On The Coefficients For Mean-Field Fractional Stochastic Delay Evolution Equations, Brahim Boufoussi, Salah Hajji Aug 2020

Continuous Dependence On The Coefficients For Mean-Field Fractional Stochastic Delay Evolution Equations, Brahim Boufoussi, Salah Hajji

Journal of Stochastic Analysis

No abstract provided.

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Dem Clustering Simplification Algorithm Based On Fractal Dimension, Zhang Fan, Xiaoyang Li, Liu Huan, Hu Wei, Li Wei Aug 2020

Dem Clustering Simplification Algorithm Based On Fractal Dimension, Zhang Fan, Xiaoyang Li, Liu Huan, Hu Wei, Li Wei

Journal of System Simulation

Abstract: Fractal is the essential characteristic of natural scenes. It can describe the irregular extent of surface topography, so it is used for digital terrain generation. As the inverse process of terrain generation, digital terrain simplification usually uses geometric properties such as curvature index as a measure to reduce the grid to improve the efficiency of electromagnetic solver calculations, flood modeling, visual simulation and other issues, while ignoring the fractal nature of the terrain features. Since a traditional simplification algorithm of DEM is difficult to identify the characteristics of complex topography, a new clustering simplification algorithm based on fractal dimension …

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Cellular Automata Model Of Non-Motor Vehicle Flow Considering Reverse Vehicles, Xianyan Kuang, Weihua Cao, Wu Yun Aug 2020

Cellular Automata Model Of Non-Motor Vehicle Flow Considering Reverse Vehicles, Xianyan Kuang, Weihua Cao, Wu Yun

Journal of System Simulation

Abstract: The phenomenon of non-motor vehicle reverse driving in one-way non-motor vehicle road occurs in most China's cities. A cellular automata model of non-motor vehicle flow mixed with reverse driving vehicles was established, which considered the different lane-changing rules of the reverse and forward vehicle. The results of the computer numerical simulation for the model show that, in low density stage, the ratio of reverse vehicles has little effect on flow and speed, and the capacity and the avenge speed decrease as the ratio of reverse vehicles increases. Lane-changing ratio has a great influence on the mixed non-motor vehicles …

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Study Of Cognitive Model For Survivable System Based On High-Order Multi-Type Π Calculus, Guosheng Zhao, Zhang Nan, Wang Jian Aug 2020

Study Of Cognitive Model For Survivable System Based On High-Order Multi-Type Π Calculus, Guosheng Zhao, Zhang Nan, Wang Jian

Journal of System Simulation

Abstract: A cognitive model for survivable system with a multilayer cognitive ability was proposed, and based on high-order multi-type π calculus, combining formal modeling of cognitive model with quantitative analysis of cognitive performance, thus can obtain the quantitative evaluation of system cognitive performance after formal modeling of system operation state, system service and internal structure. A cognitive model for survivable system with a multilayer cognitive ability was proposed. Based on high-order multi-type π calculus, formal modeling of cognitive model for survivable system in two aspects was taken. By using the tool MWB, the tests were achieved about system availability, instantaneous …

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Coupling Sph Model For Occupant Evacuation In Fires And Simulation, Zhihong Miao, Zhihui Li Aug 2020

Coupling Sph Model For Occupant Evacuation In Fires And Simulation, Zhihong Miao, Zhihui Li

Journal of System Simulation

Abstract: Computer simulation of evacuation can be very helpful in building design for fire protection and reducing casualty in compartment fire. A coupling model for occupant evacuation building fires was proposed. A continuous model was composed by treating pedestrians movement as fluid movement, and by using Smoothed Particle Hydrodynamics method to discretize this continuous model, the model was transformed into a particle system. A method for coupling FDS into the occupant evacuation model was proposed, and the amounts of smoke density and smoke charge of pedestrian were used to determine the move direction of a pedestrian and …

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Topology Modeling Of Information Grid Network For Military Applications, Mingqing Zhang, Meilin Wei, Hongshan Kong, Shuqin Dong Aug 2020

Topology Modeling Of Information Grid Network For Military Applications, Mingqing Zhang, Meilin Wei, Hongshan Kong, Shuqin Dong

Journal of System Simulation

Abstract: For the lack of military network topology research and incomprehensive consideration of topology modeling factors, a topology modeling method of information grid network for military applications was proposed. AS-level and router level topology generation algorithms were designed. A seamless integration scheme between two topologies was proposed. Simulation experiments about meeting the conditions for the topological properties and topology model deployment strategy in network simulation environment were implemented. The simulation results show that the information grid network can be remained stable in the overall nature with considering the growth, death, “preferential attachment”, invulnerability and other factors of …

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Research And Design Of All-Purpose Simulation Platform Of Fault Injection, Wenbin Yao, Zhao Ling, Wang Zhen, Yao Xiang Aug 2020

Research And Design Of All-Purpose Simulation Platform Of Fault Injection, Wenbin Yao, Zhao Ling, Wang Zhen, Yao Xiang

Journal of System Simulation

Abstract: Focusing on the limited injection position and single target system problems existing in the simulation research of fault injection, combined with the NS2 simulation technology and fault injection method, an all-purpose simulation platform of fault injection was proposed. The layered model of the targeted information system was constructed, whose topology information and service performance information was given by the matrix, and improved the generality of the simulation platform of fault injection. Based on the configuration information, the platform constructed the fault library, which brought the cost reduction and reliability promotion of the system faults. The quadruple design of the …

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Software Technology Of Transportation Virtual Simulation Experiment Teaching Center, Shiwei He, Leishan Zhou Aug 2020

Software Technology Of Transportation Virtual Simulation Experiment Teaching Center, Shiwei He, Leishan Zhou

Journal of System Simulation

Abstract: The general architecture and experiments of Transportation National Virtual Simulation Experiment Teaching Center (TNVSETC) were introduced. The features of simulation platforms which include “huge, multi-sources, iomerous” big-data platform, “whole procedure, semi-object, virtual reality” railway planning, design and operation integrated simulation platform, roadway planning, design, control and operations evaluation simulation platform were analyzed. The main modeling techniques and technique characteristics of simulation software including traffic circumstance construction technology, vehicle behavior model, pedestrian behavior model, transporation supplying model and management methods were summarized. The advice on the future development of TNVSETC simulation software was proposed.

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Simulated Training System Of Shipborne Helicopter Deck-Landing Command, Jianguo Wang, Qun E, Xiaogang Xu, Keming Yao, Xinlong Wan Aug 2020

Simulated Training System Of Shipborne Helicopter Deck-Landing Command, Jianguo Wang, Qun E, Xiaogang Xu, Keming Yao, Xinlong Wan

Journal of System Simulation

Abstract: Ship borne helicopter landing on the deck is a complex and dangerous process, and the capability of the deck landing commanders has much influence to the helicopter landing safety. The environment system of ship borne helicopter deck landing was constructed, such as wave simulation, ship rocking simulation and assist deck landing lighting system. The ship borne helicopter landing simulation training system was designed and realized, including command gesture data acquisition, gesture recognition, etc. According to the characteristic of ship borne helicopter landing command, the system applied the gesture capture technology to the landing command training. The application indicates that …

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Research On Radar Anti-Jamming Performance Evaluation Index System Based On Rough Set Theory, Zongfeng Qi, Han Shan, Jianxun Li Aug 2020

Research On Radar Anti-Jamming Performance Evaluation Index System Based On Rough Set Theory, Zongfeng Qi, Han Shan, Jianxun Li

Journal of System Simulation

Abstract: The applications of generalized rough set theory were researched for the construction and optimization of radar anti-jamming performance evaluation index system. A mass of real-valued data was converted to some interval-valued data to avoid the difficulty of classification. The H'- information entropy-based information filling technique was employed to solve the problem of missing evaluation data. The E-condition entropy-based heuristic algorithm was applied to make attribute reduction, optimize evaluation index system, and extract final decision rules. The feasibility, validity and practicability of proposed method were testified by a simulation example.

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Simulation & Analysis Of Liquid Metal Conical Helical Antenna, Zhou Yun, Shaojun Fang, Shiqiang Fu, Zhongbao Wang Aug 2020

Simulation & Analysis Of Liquid Metal Conical Helical Antenna, Zhou Yun, Shaojun Fang, Shiqiang Fu, Zhongbao Wang

Journal of System Simulation

Abstract: In order to replace the solid metal antenna, a novel liquid metal conical helical antenna was presented. The antenna is easy to adjust its shape. The circularly polarized antenna has the characteristics of small size, high gain, wide bandwidth, and it is easy to reconstruct. Taking maritime satellite communications as an example, the proposed antenna was designed, simulated and optimized for antenna impedance matching with HFSS software, and a good circularly polarized radiation and impedance characteristics for the antenna were obtained. The simulated results show that: in the entire maritime satellite communication work band (1 525-1 660.5 …

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Signaling Game Analysis And Simulation On Network Decoy Defense Strategies, Leyi Shi, Junnan Zhao, Li Qin, Wen Xiao, Liu Xin Aug 2020

Signaling Game Analysis And Simulation On Network Decoy Defense Strategies, Leyi Shi, Junnan Zhao, Li Qin, Wen Xiao, Liu Xin

Journal of System Simulation

Abstract: The network decoy confrontation is regarded as a kind of observable behavior of a multi-stage signaling game. Four types of gaming models for decoy confrontation process were constructed step by step using signaling game theory, i.e. the normal service, the mixed system of normal service and honeypot, the mixed system with two kinds of signaling, and the mixed system with two kinds of signaling and three actions. In these signaling game models, the server sent a normal signaling or honeypot signaling as the sender, while the attacker chose to access, give up or access in condition as the …

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Fusion Comparing Visualization Method For Pesticide Residue Detection Data, Hongqian Chen, Li Hui, Fang Yi, Qixian Liu, Chen Yi Aug 2020

Fusion Comparing Visualization Method For Pesticide Residue Detection Data, Hongqian Chen, Li Hui, Fang Yi, Qixian Liu, Chen Yi

Journal of System Simulation

Abstract: To express efficiently the association and difference among cities, categories and standards in pesticide residue detection data analysis, a fusion visualization method based on data statistic and OpenGL graphics library was proposed. The method can accelerate the dataset comparing and selecting for the expert interaction and data analysis. The method firstly summarizes the detection data in pesticide residue detection database according to its various category and belonging region. All the data are shown in one fusion visualization result. The result can assist expert to compare efficiently and analysis intuitionally the dataset. The data of the selected dataset in …

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Modeling And Control Of Shaking Motion Of Aerial Refueling Hose-Drogue, Zhang Jin, Suozhong Yuan, Quanquan Gong Aug 2020

Modeling And Control Of Shaking Motion Of Aerial Refueling Hose-Drogue, Zhang Jin, Suozhong Yuan, Quanquan Gong

Journal of System Simulation

Abstract: Hose-Drogue fly with the tanker in the air can produce shaking motion which increases the difficulty of coupling with a refueling drogue for a receiver plane safely and accurately. A mathematical model of shaking motion of aerial refueling hose drogue under the tanker wake and atmospheric turbulence was proposed by the method of rigid multibody dynamics. Then the balance drag wake of hose-drogue and the atmospheric turbulence on hose-drogue in different flight conditions were analyzed based on this model. To reduce the movement amplitude of the hose-drogue in the air, the controller to the motion of the hose-drogue …

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Characteristics Study Of Internal Gas-Liquid Two Phase Flow Field Of Three Layers Of Air Stirred Tank Reactor, Xiaodong Hu, Dexin Zhang, Jiang Rong, Zenghui Wu, Tian Qiang Aug 2020

Characteristics Study Of Internal Gas-Liquid Two Phase Flow Field Of Three Layers Of Air Stirred Tank Reactor, Xiaodong Hu, Dexin Zhang, Jiang Rong, Zenghui Wu, Tian Qiang

Journal of System Simulation

Abstract: The fluid dynamics and the gas-liquid distribution character in a three-layer stirred tank reactor with 2KSX (four wide blade propeller type stirrer) and PDT (parabolic disc turbine) were analyzed with the MRE (multi-reference frame) method based on Euler-Euler and population balance models. The total and local gas-hold were calculated. The conclusions show that: axial flow was produced by double stir upper KSX with radial flow produced by the third layer of PDT, gas-hold was improved with double-upper-layer stirrers axial driven and the lowest stirrer axial driven, gas-hold increased with the stirred time going on, which would not be extended …

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Modeling And Simulation Of Multi-Nozzle Ejector Based On Flowmaster, Lan Jiang, Zhu Lei, Jingquan Zhao Aug 2020

Modeling And Simulation Of Multi-Nozzle Ejector Based On Flowmaster, Lan Jiang, Zhu Lei, Jingquan Zhao

Journal of System Simulation

Abstract: A mathematical model of multi-nozzle ejector was established according to the mass conservation, energy conservation and momentum conservation, and a modification was achieved with the introduction of momentum correction coefficient and discharge coefficient. On this basis, linear coefficients used in the fluid network method were determined, then a system-level simulation model of multi-nozzle ejector was first developed with C# language on the fluid system simulation software of Flowmaster. The simulation and experimental results of the multi-nozzle ejector in an aircraft environmental control system shows that the entrainment ratio decreases with the increasing pressure ratio of primary and secondary flow. …

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Simulation And Optimization For Bulk Terminal Yard Scheduling, Dongbo Hu, Li Pan, Binbin Zhang, Guozhi Liang Aug 2020

Simulation And Optimization For Bulk Terminal Yard Scheduling, Dongbo Hu, Li Pan, Binbin Zhang, Guozhi Liang

Journal of System Simulation

Abstract: Yard is the central part of the operation process of the whole terminal. In fact, the operation of lots of bulk terminal is unscientific, which severely restricts the turnover efficiency and the throughput of the terminal. Taking the coal terminal as an example and based on its operation process, the dispatching simulation model involving all parts of the operation was established and the rules of use of the yard grids was brought forward. By optimizing the operation strategy and related parameters, it is significant to improve the input quantity of bulk terminal and the turnover efficiency.

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Study On Comprehensive Performance Of Roadheader Shovel Based On Simulation Optimization Method, Dayong Wang, Wang Hui Aug 2020

Study On Comprehensive Performance Of Roadheader Shovel Based On Simulation Optimization Method, Dayong Wang, Wang Hui

Journal of System Simulation

Abstract: An improved genetic algorithm that integrates into non-uniform mutation operator and niching technology, which could run toward the optimal solution effectively, and to better maintain the diversity of the solution and high convergence speed was proposed. Meanwhile, taking shovel width and shovel dip for design variables optimizes loading capacity, shovel grubbing force and shovel coaming thickness of roadheader shovel. Optimization results show that: shovel width is reduced by 1.33%, shovel dip is reduced by 9.47%, and Shovel coaming thickness is increased by 11.4%, which has a significant effect on the overall stability of roadheader and the shovel strength. …

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Simulation On Aircraft Infrared Exposed Range And Detection Probability, Yunfei Zhang, Mengyue Hu, Dexiong Lai, Gengjun Ma Aug 2020

Simulation On Aircraft Infrared Exposed Range And Detection Probability, Yunfei Zhang, Mengyue Hu, Dexiong Lai, Gengjun Ma

Journal of System Simulation

Abstract: According to the infrared-detector operating range equation, the method used to simulate the infrared detection probability and exposure of an aircraft was established, with the use of atmospheric transmission rate calculation method, the critical radiation strength calculation method and the detection probability calculation method. The physical meaning of the exposed range was analyzed, and an infrared detection simulation system was established. The system could be used to assess the infrared stealth performance of an aircraft, which includes the curve of detection probability and the curve of exposed range, giving the flight route and the infrared radiation intensity distribution of …

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New Energy-Saving Control Of Induction Motor Considering Core Loss, Bulai Wang, Wei Biao, Zhang Fan, Zhenzhen Huang, Yunfei Zhang Aug 2020

New Energy-Saving Control Of Induction Motor Considering Core Loss, Bulai Wang, Wei Biao, Zhang Fan, Zhenzhen Huang, Yunfei Zhang

Journal of System Simulation

Abstract: In order to further improve the running efficiency of induction motor, a new energy-saving control method was proposed. Considering the influence of varied flux, a control strategy coordinating the optimal flux with the optimal slip angular frequency based on the slip angular frequency control was built. The mathematical model of induction motor considering core loss was established. The expression of the optimal flux and slip angular frequency was obtained according to the Lagrange multiplier method when system was the highest efficiency. By using MATLAB simulation platform, a simulation model of the energy saving control system was built doing a …

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Dgetmw: Motion Video Tracking Based On Memory Watershed Disc Gradient Expansion Template, Wei Wei, Kongping Wu, Laigong Guo, Qin Meng Aug 2020

Dgetmw: Motion Video Tracking Based On Memory Watershed Disc Gradient Expansion Template, Wei Wei, Kongping Wu, Laigong Guo, Qin Meng

Journal of System Simulation

Abstract: In order to obtain ideal detection results of moving object, a new video moving object detection algorithm based on labeling watershed and detection algorithm and morphology were proposed. The image was pre-processed by diffusion model to eliminate noise interference on object detection, and the difference algorithm was used to extract outline of moving object.. Morphological operations were used to process the target outline, and marked watershed algorithm was used to segment moving object and performance was tested by simulation experiments. The simulation results show that the proposed algorithm can prevent over segmentation problems and accurately detect moving object …

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