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2020

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Articles 2971 - 3000 of 10642

Full-Text Articles in Engineering

Research Of Non-Dead-Time Control Method On Single-Phase Off-Grid Inverter Based On H6 Topology, Kun Xia, Li Jing, Ge Yue, Lirong Shen, Yiming Wang, Xu Po Aug 2020

Research Of Non-Dead-Time Control Method On Single-Phase Off-Grid Inverter Based On H6 Topology, Kun Xia, Li Jing, Ge Yue, Lirong Shen, Yiming Wang, Xu Po

Journal of System Simulation

Abstract: A novel non-dead-time control strategy based on H6 topology was proposed. Through detecting the value and direction of the output voltage and current of inductor, the power switches of bridge arm were modulated if they were in the same direction, and the freewheeling switches were modulated if they were opposite. In order to protect the DC bus voltage from shorting out, the dead time should be added during the zero-crossing of voltage and current. And the states of switches were adjusted by calculation of the control module. Then most dead time could be eliminated. The simulation model for the …


Effective T2fpso-Based T2fsvm Scene Classification Algorithm, Shuqiong Xu, Conggui Yuan Aug 2020

Effective T2fpso-Based T2fsvm Scene Classification Algorithm, Shuqiong Xu, Conggui Yuan

Journal of System Simulation

Abstract: A systematic design methodology of Type-2 Fuzzy Particle Swarm Optimization (T2FPSO) based Type-2 Fuzzy Support Vector Machine (T2FSVM) classification system was proposed for scene image to improve selectivity and robustness in the machine vision. In the novel classification system, the T2FSVM model was presented to realize a comprehensive learning of the correct class and show the superiority of the generalization capability for classification problem. Furthermore, in order to improve the performance of PSO on complex uncertain environments, the type-2 fuzzy concept was incorporated to PSO to construct T2FPSO searching algorithm, in which the interval type-2 fuzzy inertia weight …


Modular 3d Printer System Software For Research Environments, Clayton D. Ramstedt Aug 2020

Modular 3d Printer System Software For Research Environments, Clayton D. Ramstedt

Theses and Dissertations

The Nordin group at Brigham Young University has been focused on developing 3D printing technology for fabrication of lab-on-a-chip (microfluidic) devices since 2013. As we showed in 2015, commercial 3D printers and resins have not been developed to meet the highly specialized needs of microfluidic device fabrication. We have therefore created custom 3D printers and resins specifically designed to meet these needs. As part of this development process, ad hoc 3D printer control software has been developed. However, the software is difficult to modify and maintain to support the numerous experimental iterations of hardware used in our custom 3D printers. …


Investigation Of Hybrid Positioning Algorithm Based On Wifi, Fucheng Yin, Wu Dong, Wang Yan, Zhicheng Ji Aug 2020

Investigation Of Hybrid Positioning Algorithm Based On Wifi, Fucheng Yin, Wu Dong, Wang Yan, Zhicheng Ji

Journal of System Simulation

Abstract: TDOA(Time Difference of Arrival) and AOA(Angel of Arrival) methods require additional sensing mechanisms and have poor positioning accuracy used in WiFi environment, so a novel TDOAAOE hybrid positioning algorithm was proposed. The proposed algorithm used the AOE (Angle of Emission) information instead of AOA information to estimate the position of a WiFi-based mobile terminal. In this method, access points emitted signals with angle information encoded in beacon packets through directional antennas; which was rotated by motors. WiFi-based mobile devices estimated angles of the access points by receiving and decoding these beacon packets, which calculated the position themselves. This method …


Self-Adaptive Multi-Swarm Particle Swarm Optimization Algorithm, Xuewen Xia, Bojian Wang, Jin Chang, Guoliang He, Chengwang Xie, Wei Bo Aug 2020

Self-Adaptive Multi-Swarm Particle Swarm Optimization Algorithm, Xuewen Xia, Bojian Wang, Jin Chang, Guoliang He, Chengwang Xie, Wei Bo

Journal of System Simulation

Abstract: To overcome the shortcomings of poor ability to escape a local optimal, premature convergence and low precision of the traditional particle swarm optimization algorithm (PSO), a self-adaptive multi-swarm particle swarm optimization (SMPSO) was proposed. In SMPSO, the whole population was divided into many parallel-evolution multi-swarms, the aim of which was to keep diversity of the population. Furthermore, a self-adaptive regrouping operator was proposed to reinforce the information sharing and interaction between different swarms. In addition, particles’ historical information were periodic sampling and the statistics results were used to direct the best solution to carry out a detecting …


Precisely Algorithm And Simulation Of Plurality Of Random Deployed Circulars’ Total Coverage Area, Zhang Ye, Liu Kui, Yuzhi Chen, Junyang Liu, Jianchao Du Aug 2020

Precisely Algorithm And Simulation Of Plurality Of Random Deployed Circulars’ Total Coverage Area, Zhang Ye, Liu Kui, Yuzhi Chen, Junyang Liu, Jianchao Du

Journal of System Simulation

Abstract: A precisely algorithm of total coverage area when a plurality of circulars are random deployed and overlapping with each other is needed. The key issues of the solution are the calculating principle of the overlapping area, the differentiation and enumeration of the multi-overlapping circulars, and the calculation of the multi-shaped curved edges. Based on the inclusion-exclusion principle, overlapping area was added or subtracted to the amount area. The computer calculation process was proposed. Because the circulars are random deployed, in order to ensure the area coverage, the area cover rate problem of repeatedly deployment of the circulars were …


Assessment Model Of Conflict Probability At Airport Surface Intersection, Weijun Pan, Xiaolin Luo, Kang Rui, Chenyu Huang, Zhenghong Xia, Wenbin Qiu Aug 2020

Assessment Model Of Conflict Probability At Airport Surface Intersection, Weijun Pan, Xiaolin Luo, Kang Rui, Chenyu Huang, Zhenghong Xia, Wenbin Qiu

Journal of System Simulation

Abstract: Based on aircraft characteristics, the assessment model of conflict probability at airport surface intersection was studied to ensure the safety of airport ground safety. The engine jet effect distance was introduced to expand the scope of intersection conflict, describing the process of aircraft conflict. The model with the actual operation data was verified, and the speed interval's impact on the model was analyzed and discussed. In the view of three motion states of aircraft, this model analyzed the variations in conflict probability. When speed variation range is 0.5m/s, probability analysis of the conflict is more ideal, and can improve …


Method To Calculate Multi-Objective And H2/H∞ Control Of Vehicle Vertical Vibration System, Jianjun Meng, Bai Huan, Mou Jian, Yin Ming, Xuri Guan Aug 2020

Method To Calculate Multi-Objective And H2/H∞ Control Of Vehicle Vertical Vibration System, Jianjun Meng, Bai Huan, Mou Jian, Yin Ming, Xuri Guan

Journal of System Simulation

Abstract: Aiming at the disadvantage of single object in railway vehicle damping system,the multi-objective optimal control law of railway vehicle damping system was devised to balance shock absorption control and energy saving control. To improve the riding comfortability and reduce the energy consumption, the multi-objective H2/H∞ output-feedback controller based on LMI was developed for an active suspension of 6-DOF vertical vibration model of railway vehicle. Norm H2 of the actuator output was taken as the energy consumption indexes, and norm H∞ of the vertical vibration displacement, the acceleration and the nutation angle was taken as …


New Voltage Balancing Method For Cascaded Rectifier Based On Predictive Power Model, Hongbin Pan, Linhai Liu, Zhiyong Xiao, Sicheng Ou, Maokun Zhu, Fen Xu Aug 2020

New Voltage Balancing Method For Cascaded Rectifier Based On Predictive Power Model, Hongbin Pan, Linhai Liu, Zhiyong Xiao, Sicheng Ou, Maokun Zhu, Fen Xu

Journal of System Simulation

Abstract: The dq synchronous system was built by constructing virtual orthogonal voltage and current based on second order generalized integrator. The predictive power model was derived to construct main control system of cascaded H-bridge rectifier combining the instantaneous power theory, which took the duty cycle of active and reactive power as control object. Then, a new voltage balancing control strategy was proposed dealing with the problem of DC voltage imbalance in cascaded H-bridge rectifier. The modification of active power was obtained by the voltage balance controller when the objective function of coupling effect achieves minimum and the active power was …


Global Optimized Photovoltaic Mppt Algorithm Based On Pso And Incremental Conductance Method, Yunjun Yu, Liu Tao, Shisheng Wang, Jianbo Xin, Xiaohua Nie Aug 2020

Global Optimized Photovoltaic Mppt Algorithm Based On Pso And Incremental Conductance Method, Yunjun Yu, Liu Tao, Shisheng Wang, Jianbo Xin, Xiaohua Nie

Journal of System Simulation

Abstract: The P-V array characteristic curve exhibits a plurality of local maximum power point under conditions of partial shading. The incremental conductance method maybe track an extreme value point that is not the largest power point, thus lead to tracking failure. The PSO algorithm has the characteristics of global optimization, but its tracking precision is deficient. A global MPPT algorithm based on PSO algorithm by incremental conductance method was proposed, PSO algorithm could quickly locate to the approximate global MPP, INC could further precise the MPP. Compared to the traditional incremental conductance method Simulink simulation and the research when …


Viability Control Of Rigid Body Wheeled Robots For High Speed Obstacle Avoidance, Liu Lei, Gao Yan, Yuepeng Wu Aug 2020

Viability Control Of Rigid Body Wheeled Robots For High Speed Obstacle Avoidance, Liu Lei, Gao Yan, Yuepeng Wu

Journal of System Simulation

Abstract: The robot is taken as a point during most existing obstacle avoidance control methods for wheeled robot. These methods have limitations in actual situation. When a robot is considered as a rigid body, in order to get high speed performance, the relationship between robot model, contour and obstacle should be considered in detail. An approach to avoiding obstacle with high speed based on viability theory was proposed for wheeled robots. The line features were extracted from the obstacles, and then high dimension viability boundaries were designed via these features, rigid body contours and states of the robot. According to …


Energy Efficiency Optimization For Discrete Manufacturing Workshop Based On Discrete Teaching-Learning-Based Optimization Algorithm, Junhui Xu, Wang Yan Aug 2020

Energy Efficiency Optimization For Discrete Manufacturing Workshop Based On Discrete Teaching-Learning-Based Optimization Algorithm, Junhui Xu, Wang Yan

Journal of System Simulation

Abstract: Because the discrete manufacturing workshop is multi-objective and multi-constraint, an energy efficiency optimization model whose optimization objective was to minimize the total energy consumption was built for discrete manufacturing workshop. Besides, an improved teaching-learningbased (TLBO) optimization algorithm for discrete energy efficiency workshop optimization was proposed. This improved algorithm introduced adaptive parameter in training phase to improve the learning efficiency and adaptability of the algorithm. In addition, second discrete process was introduced in the teaching stage and learning stage, respectively. This algorithm could be applied to the optimization of discrete manufacturing workshop under the precondition of ensuring the …


Simulation Technology Research On Streak Tube Imaging Lidar, Wenze Xia, Shaokun Han, Jingya Cao Aug 2020

Simulation Technology Research On Streak Tube Imaging Lidar, Wenze Xia, Shaokun Han, Jingya Cao

Journal of System Simulation

Abstract: A simulation model on streak tube imaging lidar was introduced. The range equation of lidar, the pulse model of illuminating laser and the scanning equation were used in the model. The system noise was analyzed. The experiment result shows the effectiveness of proposed simulation model. The effect of the pulse laser peak power on distance precision of reconstructed range image was analyzed. This method provided theoretical guidance and desired result inspection for designing of the streak tube imaging lidar.


Modeling And Simulation Of Offshore Support Vessel Anchoring Operation, Hongbo Sun, Chaojian Shi, Wenjin Lin Aug 2020

Modeling And Simulation Of Offshore Support Vessel Anchoring Operation, Hongbo Sun, Chaojian Shi, Wenjin Lin

Journal of System Simulation

Abstract: In order to understand the configurations of mooring line and working wire, tension variation at release point of working wire and the influence of the offshore support vessel during anchoring operation, a mathematical models of OSV anchoring operation was established. According to the MMG (Ship Manoeuvring Mathematical Model Group) ship motion mathematical modeling theory, a 6dof ship motion mathematical model was built. And a 6dof cable motion mathematical model was established with finite difference method. A coupling ship-cable-anchor-cable system model was established. The system motion simulations were carried out, and the results indicate that the model …


Energy Consumption Analysis Of Discrete Manufacturing Based On Improved Principal Component Analysis Method, Chen Yan, Wang Yan Aug 2020

Energy Consumption Analysis Of Discrete Manufacturing Based On Improved Principal Component Analysis Method, Chen Yan, Wang Yan

Journal of System Simulation

Abstract: Due to the complexity of energy consumption of the discrete manufacturing system and the interaction between energy consumption indexes, the result of energy consumption analysis is hard to obtain, establishing energy efficiency evaluation index of discrete system, based on the three levels of energy consumption of products, equipment energy efficiency, the energy efficiency of task process. Furthermore, a method was proposed to analyze the discrete manufacturing process energy consumption based on improved principal component analysis method. The method introduced importance weights, overcame the shortcoming of traditional component analysis, which only emphasized the information weights, combined the subjective and …


Isolation And Characterization Of Bacteria In A Toluene-Producing Enrichment Culture Derived From Contaminated Groundwater At A Louisiana Superfund Site, Madison Mikes Aug 2020

Isolation And Characterization Of Bacteria In A Toluene-Producing Enrichment Culture Derived From Contaminated Groundwater At A Louisiana Superfund Site, Madison Mikes

LSU Master's Theses

In an effort to better understand the role that various microbes may play in toluene production, bacteria from a toluene-producing enrichment culture derived from contaminated groundwater at a Superfund site were cultivated and isolated on low nutrient solid media. A total of 14 solid medium formulations containing varying pH ranges, carbon sources, solidifying agents, and incubation gas headspaces were used to obtain 278 isolates in pure culture. Isolated bacteria, identified using partial 16S rRNA gene sequences, were most closely related with the genera Anoxybacillus, Azospira, Bacillus, Bradyrhizobium, Cellulosimicrobium, Micrococcus, and Propionicimonas.

Further attempts …


Ronald E. Mcnair Scholars Program Profiles And Abstracts 2020, Mcnair Scholars Program Aug 2020

Ronald E. Mcnair Scholars Program Profiles And Abstracts 2020, Mcnair Scholars Program

McNair Symposium

This is the complete event program and provides presentation abstracts and biographies of McNair scholars and their mentors.


Studies Of Two-Phase Flow With Soluble Surfactant, Ryan Peter Atwater Aug 2020

Studies Of Two-Phase Flow With Soluble Surfactant, Ryan Peter Atwater

Dissertations

Numerical methods are developed for accurate solution of two-phase flow in the zero Reynolds number limit of Stokes flow, when surfactant is present on a drop interface and in its bulk phase interior. The methods are designed to achieve high accuracy when the bulk Péclet number is large, or equivalently when the bulk phase surfactant has small diffusivity

In the limit of infinite bulk Péclet number the advection-diffusion equation that governs evolution of surfactant concentration in the bulk is singularly perturbed, indicating a separation of spatial scales. A hybrid numerical method based on a leading order asymptotic reduction in this …


Photovoltaic Systems On Dairy Farms: Financial And Renewable Multi-Objective Optimization (Farmoo) Analysis, Michael Breen, J. Upton, Michael D. Murphy Aug 2020

Photovoltaic Systems On Dairy Farms: Financial And Renewable Multi-Objective Optimization (Farmoo) Analysis, Michael Breen, J. Upton, Michael D. Murphy

Publications

No abstract provided.


Gradient-Based Layout Optimization Of Large Wind Farms: Coupled Turbine Design, Variable Reduction, And Fatigue Constraints, Andrew P. J. Stanley Aug 2020

Gradient-Based Layout Optimization Of Large Wind Farms: Coupled Turbine Design, Variable Reduction, And Fatigue Constraints, Andrew P. J. Stanley

Theses and Dissertations

Wind farm layout optimization can greatly improve wind farm performance. However, past wind farm design has been limited in several ways. Wind farm design usually assumes that all the turbines throughout the farm should be exactly the same. Oftentimes, the location of every turbine is optimized individually, which is computationally expensive. Furthermore, designers fail to consider turbine loads during layout optimization. This dissertation presents four studies which provide partial solutions to these limitations and greatly improve wind farm layout optimization. Two studies explore differing turbine designs in wind farms. In these studies, Wind farm layouts are optimized simultaneously with turbine …


Large Face Shield, Michael Stieven, Dylan Huddleston, Timothy Bragg Aug 2020

Large Face Shield, Michael Stieven, Dylan Huddleston, Timothy Bragg

Washington University / UMSL Mechanical Engineering Design Project JME 4110

The large face shield is designed to help stop the spread of COVID-19 Coronavirus in occupational environments where close contact is necessary.


Resonance Of Droplets In Constricted Capillary Tubes: Critical Factors And Nonlinearity, Chao Zeng, Wen Deng, M. Bayani Cardenas Aug 2020

Resonance Of Droplets In Constricted Capillary Tubes: Critical Factors And Nonlinearity, Chao Zeng, Wen Deng, M. Bayani Cardenas

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Resonance of droplets in constricted capillary tubes responding to external vibratory excitation can be theoretically characterized by the abstract coefficients such as resonant frequency and rate of damping. A physically sound model, however, is needed to relate these abstract coefficients to the fluid properties of two-phase fluid, geometric properties of tube, and features of excited waves. A hydrodynamic model, based on the moving-boundary control volume concept and the transient oscillatory velocity profile, was developed to characterize the resonance of droplets. This model was validated against computational fluid dynamics simulation results expressed in both time and frequency domains. Dominant factors including …


Modeling And Simulation On Dynamics Of Epidemic Disease Based On Social Division Of Labor, Haibin Li Aug 2020

Modeling And Simulation On Dynamics Of Epidemic Disease Based On Social Division Of Labor, Haibin Li

Journal of System Simulation

Abstract: Prediction is an essential part of the epidemic prevention and control system, and it is of great significance to accurately establish a dynamic model of epidemiological evolution. The existing epidemiological modeling methods rarely consider the social division of labor of different groups. The entire group is divided into three subgroups, the ordinary residents, the social service personnel, and the front-line medical workers. Based on the heterogeneous uniform mixing theory, the subgroup adjacency matrix is used to represent the contact relationship between individuals, and a time-lapse dynamic model of epidemic spread and evolution is established. The simulation results show that …


Designerly Living Labs: Early-Stage Exploration Of Future Sustainable Concepts, Martin Sjöman, Mia Hesselgren Aug 2020

Designerly Living Labs: Early-Stage Exploration Of Future Sustainable Concepts, Martin Sjöman, Mia Hesselgren

DRS Biennial Conference Series

It is increasingly clear that the sustainable transitions needed to counter climate change depend on lifestyle changes. However, the task of encouraging a shift to more sustainable lifestyles is highly complex. This paper describes an emerging design research method to explore possible pathways towards such sustainable transitions. We describe a living labs-approach based on design practice, developed within [Author affiliation], a design and sustainability research group at [Author affiliation]. We refer to this method as Designerly Living Labs. Based on empirical learnings from four such Living Labs we present eight key characteristics. We then highlight some important aspects that affect …


Near Simultaneous Laser Scanning Confocal And Atomic Force Microscopy (Conpokal) On Live Cells, Joree N. Sandin, Surya P. Aryal, Thomas E. Wilkop, Christopher I. Richards, Martha E. Grady Aug 2020

Near Simultaneous Laser Scanning Confocal And Atomic Force Microscopy (Conpokal) On Live Cells, Joree N. Sandin, Surya P. Aryal, Thomas E. Wilkop, Christopher I. Richards, Martha E. Grady

Physiology Faculty Publications

Techniques available for micro- and nano-scale mechanical characterization have exploded in the last few decades. From further development of the scanning and transmission electron microscope, to the invention of atomic force microscopy, and advances in fluorescent imaging, there have been substantial gains in technologies that enable the study of small materials. Conpokal is a portmanteau that combines confocal microscopy with atomic force microscopy (AFM), where a probe "pokes" the surface. Although each technique is extremely effective for the qualitative and/or quantitative image collection on their own, Conpokal provides the capability to test with blended fluorescence imaging and mechanical characterization. Designed …


Measurement And Simulation Of Head Impacts In Mixed Martial Arts, Aidan Meagher Aug 2020

Measurement And Simulation Of Head Impacts In Mixed Martial Arts, Aidan Meagher

Doctoral

No abstract provided.


Incorporating Behavioral Theory In Design Ideation For Changing Sustainability Behaviors, Aysha Alwazzan, G. Mauricio Mejía, Yumeng Xie, Daniel Fischer Aug 2020

Incorporating Behavioral Theory In Design Ideation For Changing Sustainability Behaviors, Aysha Alwazzan, G. Mauricio Mejía, Yumeng Xie, Daniel Fischer

DRS Biennial Conference Series

As design research develops, theory is increasingly available for designers. However, there is a limited understanding of how practitioners incorporate theory in activities such as ideation. This exploratory study aims to understand how novice designers respond to and incorporate theory in the ideation phase of the design process. A theory from behavioral economics – nudging – was introduced to the participants while ideating in problems of changing sustainability behaviors. Data collected included focused observations and interviews. Participants appeared to understand some behavioral theoretical concepts, which can be explained in the current pervasive use of human-centered approaches. While there were some …


Modeling And Effects Of Non-Homogeneous Infiltration On Material Properties Of Carbon-Infiltrated Carbon Nanotube Forests, Daniel Owens Snow Aug 2020

Modeling And Effects Of Non-Homogeneous Infiltration On Material Properties Of Carbon-Infiltrated Carbon Nanotube Forests, Daniel Owens Snow

Theses and Dissertations

This work investigates the material properties and production parameters of carbon infiltrated carbon nanotube structures (CI-CNT's). The impact of non homogeneous infiltration and the porosity of cross section regions, coupled with changes in designed geometry, in this case beam width, on the density and modulus of elasticity are compared. Three potential geometric models of beam cross section are proposed and evaluated. 3-point bending, SEM images, and numerical optimization are used to assess the validity of each model and the implications they have for future CI-CNT material applications. Carbon capping near exterior beam surfaces is observed and determined to be a …


Gas Chromatography Micro-Chip With High Temperature Interface And Silk Screen Heaters, Carlos R. Vilorio Aug 2020

Gas Chromatography Micro-Chip With High Temperature Interface And Silk Screen Heaters, Carlos R. Vilorio

Theses and Dissertations

There has been substantial market demand for a portable Gas Chromatography (GC) system. Throughout the years, much progress has been made on fabricating a micro system that works as well as a benchtop system. Unfortunately, even though many substrates, channel types, channel widths, temperature control systems, and interface solutions have been attempted, existing versions of the micro-GC still fall short of the ideal. This thesis presents the design, fabrication, and testing of a silicon based micro-GC column that presents a solution for interfacing and heating of the chip. A polyimide resin is used to create a durable high temperature low …


A Review Paper: Analysis Of Weka Data Mining Techniques For Heart Disease Prediction System, Basma Jumaa Saleh, Ahmed Yousif Falih Saedi, Ali Talib Qasim Al-Aqbi, Lamees Abdalhasan Salman Aug 2020

A Review Paper: Analysis Of Weka Data Mining Techniques For Heart Disease Prediction System, Basma Jumaa Saleh, Ahmed Yousif Falih Saedi, Ali Talib Qasim Al-Aqbi, Lamees Abdalhasan Salman

Library Philosophy and Practice (e-journal)

Data mining is characterized as searching for useful information through very large data sets. Some of the key and most common techniques for data mining are association rules, classification, clustering, prediction, and sequential models. For a wide range of applications, data mining techniques are used. Data mining plays a significant role in disease detection in the health care industry. The patient should be needed to detect a number of tests for the disease. However, the number of tests should be reduced by using data mining techniques. In time and performance, this reduced test plays an important role. Heart disease is …