Engineering Commons^™

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 …

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. …

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 …

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 …

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.

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 …

Influence Of Aggregates In Concrete On Fiber-Optic Based Thermal Integrity Profiling Analysis Of Concrete Structures, Ruoyu Zhong, Wen Deng

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Fiber-optic sensor has drawn wide attention in the non-destructive testing and evaluation of civil engineering materials due to its high accuracy and resolution as well as cost-efficiency. Currently, using optical fiber as the temperature sensor is proposed to conduct the thermal integrity profiling (TIP) of concrete structures. However, concrete is not a thermally homogeneous material as assumed in current studies of concrete TIP. Its essential components, such as aggregates may cause thermal inhomogeneity problems when implementing fiber-optic sensors for TIP. In this paper, we use the concrete structures with different grades of aggregates to conduct numerical simulation for non-destructive thermal …

First-Principles Investigation Of Doping And Alloying Of Β-Ga2o3, Ben Tattersfield

McKelvey School of Engineering Graduate Student Theses & Dissertations

β-Ga₂O₃ is an emergent semiconductor for power electronics applications. It has a wide band gap of 4.8 eV and is transparent on the whole spectrum of visible light up to deep ultraviolet. It has a high Baliga figure of merit (BFOM) — a weighted numerical combination of the dielectric constant, charge carrier mobility, and critical breakdown field —, which is commonly used for a quantitative comparison of semiconductors for high-current operation and power switching applications. β-Ga₂O₃ can be grown as thin films or as large single crystals by melt growth-techniques, which is …

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

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 …

Digital Simulation And Synthesis Of Yunnan Out-Of-Print Woodcuts Based On Nicks, Li Jie, Jianxia Hou, Xuesong Wang, Xu Dan, Yuanyuan Pu

Journal of System Simulation

Abstract: Woodcut printing is a painting, in which knife and wood block are used instead of pen and paper. Yunnan out-of-print woodcut is an extension of the woodcut printing. By working with a single block and multiple printings, Yunnan out-of-print woodcut can produce special effects of color overlap. Following the working process of it, an automatic method was studied based on nicks to synthesize a virtual Yunnan out-of-print woodcut. Image was sliced out by using color clustering. A global orientation field was got which reflected the gradient information. Real nicks guided by streamlines was placed based on orientation field. The …

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 …

Flow Visualization Based On Enhanced Streamline Line Integral Convolution, Han Min, Haichao Zhang, Maosong Bian, Danchen Zheng

Journal of System Simulation

Abstract: In order to show the flow information clearly and reduce the calculation of linear integral convolution, an enhanced streamline linear integral convolution algorithm was proposed. The generation of streamlines were improved. Critical points were detected and the points’ area with a gradient fill was generated. Combined two integration methods in different areas, the integration step was updated adaptively. Utilizing the parallelism of GPU and GLSL (OpenGL shading language), the algorithm further improved the sharpness of the output image. Experiments show that the improved linear integral convolution algorithm posses both the speedability and the precision. And the flow visualization of …

Research On Characteristics Of City Agglomeration Compound Traffic Network, Chengbing Li, Wei Lei, Yucheng Hao

Journal of System Simulation

Abstract: In order to serve the economic development of city agglomeration, revealing the characteristics of city agglomeration compound traffic network was focused on. The model of city agglomeration compound traffic network was built using the site mapping method based on analysis of the structure of city agglomeration compound traffic network. The characteristics and specific calculation method based on complex network theory were put forward. Compound traffic network of road and rail traffic network was generated through an empirical study of Hu-Bao-E city group, and node degree, node degree distribution, average path length, clustering coefficient of this network be computed …

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

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 …

Grey Wolf Optimizer For Parameters Identification Of Induction Motor With Improved Model, Xiaoyi Lü, Huang Song, Wang Yan, Zhicheng Ji

Journal of System Simulation

Abstract: According to the problems of inaccurate parameters estimation of the induction motor in high-performance control, a grey wolf optimizer was used to identify the parameters of the induction motor. Grey wolf optimizer is a new meta-heuristic. It is simple and flexible to implement, and has fewer parameters to tune. Considering that two typical dynamic mathematical models have different identification precision on different parameters, the improved identification model of the induction motor was proposed. Compared with typical model, simulation results show that the proposed model obviously improves the identification performance of resistances especially stator resistance, verifying the validity …

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 …

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 …

Modeling And Simulation Of Boiler Superheated Steam Temperature System Based On System Dynamics, Le Wei, Yuanyuan Yan

Journal of System Simulation

Abstract: Based on the principle of system dynamics, from the perspective of mass and energy conservation, taking the causal loop diagrams and the stock and flow diagrams as the carriers, and starting from the running mechanism of the system, the system dynamics model for the boiler superheated steam temperature system was established. This model has clear structure and reasonable complexity. By using the high temperature super-heater of the 300 MW boiler-turbine unit of Hebei Qingyuan Power Plant as the research object, simulation studies were carried out in Vensim PLE environment. The simulation curves were compared with the curves of …

Routing Optimization In Heterogeneous Wireless Networks For Space And Mission-Driven Internet Of Things (Iot) Environments, Sara El Alaoui

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

As technological advances have made it possible to build cheap devices with more processing power and storage, and that are capable of continuously generating large amounts of data, the network has to undergo significant changes as well. The rising number of vendors and variety in platforms and wireless communication technologies have introduced heterogeneity to networks compromising the efficiency of existing routing algorithms. Furthermore, most of the existing solutions assume and require connection to the backbone network and involve changes to the infrastructures, which are not always possible -- a 2018 report by the Federal Communications Commission shows that over 31% …

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

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

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 …

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

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.

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 …

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

Publications

No abstract provided.

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 …

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 …