Physical Sciences and Mathematics Commons^™

Influence Of Composite Materials Surface Metal Mesh On Helicopter Lightning Stroke Effects, Junling Huang, Jiayu Xie

Journal of System Simulation

Abstract: The metal wire mesh is usually adopted to prevent the lightning stroke on composite materials. The effects of different materials and different thickness of metal mesh on helicopter lightning electromagnetic effect are compared. According to the method recommended by SAE-ARP5416, a numerical simulation software is used for carrying out the high current injection simulation. The results show that the surface mount metal mesh can effectively reduce the harm of lightning electromagnetic coupling effect; the difference between aluminum and copper on anti-lightning stroke effect is not obvious; when the thickness of aluminum grid is less than 0.15 mm, the …

Modeling And Simulations Of Peptoids, Pu Du

LSU Doctoral Dissertations

Polypeptoids, or poly-N-substituted glycines, are a class of sequence defined polymers that are structural mimics of polypeptides. Polypeptoids currently have received a growing interest due to their improved thermal stability, larger chemical diversity, and easier synthetic pathways as compared to peptides. Their lack of backbone hydrogen bonding and stereochemistry coupled with their easily tunability make them an ideal prototypical model system to study the effect of secondary/non-covalent interactions on self-assembly in solution. In order to develop a molecular level understanding of the effect of secondary interactions on polypeptoid self-assembly, systematic studies were carried out using molecular dynamics simulations on several …

Recover Data In Sparse Expansion Forms Modeled By Special Basis Functions, Abdulmtalb Mohamed Hussen

Dissertations

In data analysis and signal processing, the recovery of structured functions (in terms of frequencies and coefficients) with respect to certain basis functions from the given sampling values is a fundamental problem. The original Prony method is the main tool to solve this problem, which requires the equispaced sampling values.

In this dissertation, we use the equispaced sampling values in the frequency domain after the short time Fourier transform in order to reconstruct some signal expansions, such as the exponential expansions and the cosine expansions. In particular, we consider the case that the phase of the cosine expansion is quadratic. …

Smart Design And Simulation Of Aerospace Control System Based On Digital Twin, Xiaoxiang Liu, Tang Liang, Haibo Zeng, Yubai Liu, Xinbang Zhang

Journal of System Simulation

Abstract: In accordance with the demand for intelligent development of spacecraft, and on the basis of the existing model-driven aerospace control design and simulation system, the new technological architectures using the digital twin and digital thread technique are carried out to achieve intelligent scheme design, simulation verification and in-orbit analysis. Employing the intelligent interconnection concept of cyber-physical systems, the space-ground integrated big data analysis and knowledge automation system are proposed. Based on this, the practical application scenarios are put forward through the full development flow and the entire life cycle. Not only it covers the smart application of information technology, …

Visual Simulation Of Dynamic Burning Scene Of Single Plant, Weilong Ding, Linfeng Luo, Zheng Lei, Fuli Wu, Lifeng Xu

Journal of System Simulation

Abstract: At present, the research of the interactive process between plants and the flame mainly focuses on the visual simulation of forest fire scenario, but it is lack of the study on description of the interaction of individual plants and flame in detail. Aiming at this issue, this paper proposed a visual solution to model the process of a single plant burning. We established a plant model based on the branch node relationship and used particle system to model the flame. We set up a distance temperature field around a flame by using bounding sphere, and used a collision …

Recognition Method On Two-Phase Flow Regime Based On Cross Recursive Analysis, Yongbo He, Yushan Dong, Rongrong Xue

Journal of System Simulation

Abstract: Aiming at the problems that the two-phase flow regime recognition speed is slow and the recognition accuracy is low, a flow regime recognition method is proposed based on cross recursive analysis (CRA) without imaging. The false nearest neighbors are used to analyze flow regime capacitance values measured by capacitance sensor to obtain an optimal embedding dimension; and the embedding dimension of cross recursive plot is established for several typical flow patterns. The capacitance values of the simulation flow regimes and the reference flow regimes are analyzed using cross recursion to get a set of cross recursive plots. The similarity …

Multi-Objective Operation Scheduling Optimization Of Shipborne-Equipment Based On Genetic Algorithm, Jinsong Bao, Zhiqiang Li, Yaqin Zhou

Journal of System Simulation

Abstract: Multi-objective operation scheduling of shipborne equipment is a complex combinational optimization problem under multi-task system. Existing research focuses mainly on single-objective optimization while several other objectives need to be considered during real operation such as path, duration, resource, etc. Considering the operation scheduling before exporting of an amphibious landing ship as the research object, both scheduling duration and resource requirement under the precedence constraint are optimized. The mathematical model of this multi-objective operation scheduling is established and solved using genetic algorithm. A fitness function which can be self-adaptively adjusted is designed; an adapting encoding strategy, a crossover operator, and …

Trajectory Planning Method Of Overhead Crane, Xuejuan Shao, Li Yao, Jinggang Zhang, Xueliang Zhang

Journal of System Simulation

Abstract: To make the trolley of bridge crane move stably with smooth acceleration, a polynomial acceleration trajectory is proposed based on the constraint conditions of the crane and the friction between the trolley and the rail. An anti-swing plan is designed employing the dynamic coupling relationship between the motion of the trolley and the load swing. Results indicate that when the length of the rope is changed, the swing angle of the trolley is still within the limits. The stability of the system is proved by constructing Lyapunov energy equations, and the Barbalat lemma confirms that the planned reference trajectory …

Development Of Fertilizer Coatings From Polyglyoxylate-Polyester Blends Responsive To Root-Driven Ph Change., Spencer M Heuchan, Bo Fan, Jessica J Kowalski, Elizabeth R Gillies, Hugh A L Henry

Chemistry Publications

Many current controlled-release fertilizers (CRFs) are coated with nonbiodegradable polymers that can contribute to microplastic pollution. Here, coatings of self-immolative poly(ethyl glyoxylate) (PEtG) capped with a carbamate and blended with polycaprolactone (PCL) or poly(l-lactic acid) (PLA) were evaluated. They were designed to depolymerize and release fertilizers in the vicinity of plant roots, where the pH is lower than that in the surrounding environment. PEtG/PCL coatings exhibited significant temperature and pH effects, requiring 18 days at pH 5 and 30 °C, compared to 77 days at pH 7 and 22 °C, to reach 15% mass loss. Plant roots were also effective …

Postmagmatic Tectonic Evolution Of The Outer Izu‐Bonin Forearc Revealed By Sediment Basin Structure And Vein Microstructure Analysis: Implications For A 15 Ma Hiatus Between Pacific Plate Subduction Initiation And Forearc Extension, Walter Kurz, Peter Micheuz, Gail L. Christeson, M. Reagan, John W. Shervais, Steffen Kutterolf, A. Robertson, Kurt Krenn, K. Michibayashi, D. Quandt

Geosciences Faculty Publications

International Ocean Discovery Program Expedition 352 recovered sedimentary‐volcaniclastic successions and extensional structures (faults and extensional veins) that allow the reconstruction of the Izu‐Bonin forearc tectonic evolution using a combination of shipboard core data, seismic reflection images, and calcite vein microstructure analysis. The oldest recorded biostratigraphic ages within fault‐bounded sedimentary basins (Late Eocene to Early Oligocene) imply a ~15 Ma hiatus between the formation of the igneous basement (52 to 50 Ma) and the onset of sedimentation. At the upslope sites (U1439 and U1442) extension led to the formation of asymmetric basins reflecting regional stretch of ~16–19% at strain rates of …

Overview Of Digital Twins Application And Safe Development, Li Xin, Liu Xiu, Xinxin Wan

Journal of System Simulation

Abstract: The Digital Twins simulate the whole process of the manufacture, and promote the development of smart manufacturing and other fields. In view of the rapid development and application of Digital Twins, the concept and history of Digital Twins are outlined, and its related technology system is given. The main application and development trend of Digital Twins in intelligent manufacturing as while as the main characters of Digital Twins in smart cities are combed. The cyber security problem of Digital Twins is discussed for intelligent manufacturing and smart cities. The scheme and suggestion are given for ensuring the cyber security …

Multi-Projector Annular Display Based On Laser Marking Points, Shuiying Ge, Jitao Neng, Shibiao Xu, Xiaopeng Zhang

Journal of System Simulation

Abstract: This paper proposes a software method to construct a multi-projector display system. Based on the known geometric parameters of the projection curve surface such as radius, radian and the height of the circular-screen and the laser marking points, this method calculates the projection matrix of each projector to warp the image of each projector correctly. The Alpha blending and gamma rectification techniques are used to do the color blending. The experimental results show that the geometric warping and color blending effects of the seamless multi-projector display system are stable and effective.

Adaptive Backstepping Control Based Closed-Loop I/F Control Of Sensorless Permanent Magnet Synchronous Generator, Chang Da, Yu Yang, Zengqiang Mi, Xiaoming Zheng, Chenjun Sun

Journal of System Simulation

Abstract: A novel strategy applied closed-loop adaptive back-stepping control to permanent magnet synchronous generator (PMSG) is proposed targeting the problem of the modification of torque for mechanical elastic energy storage (MEES) system utilizing PSMG as power source. This paper establishes the mathematical model of MEES system and PMSG, and presents the closed-loop adaptive backstepping control which makes the angle between the dq axis oriented by the current of stator and the dq axis oriented by the rotor a constant value via the speed and current closed-loop based on the analysis of open-loop I/f control. The closed-loop adaptive back-stepping control can …

Research And Simulation Verification Of Integrated Access Technology For Electrical Equipment Based On Edge Computing, Zou Ping, Ruijie Shi, Xike Wu, Chuang Li, Yilin Zhang, Huang Jian, Li Lin

Journal of System Simulation

Abstract: In order to solve the problem of information islands existing in the production process of traditional electrical equipment, this paper proposes a technology for equipment integration into the industrial internet cloud platform. Based on the edge computing and WebService technologies, two models of device integration direct access and indirect access were established. The direct access model was verified by application simulation in a production workshop, which realized the high-speed and stable data transmission between the equipment and the industrial internet cloud platform. The results show that the technology is feasible and effective. The application of this device integration …

Two-Machine Co-Simulation Based On Mobile Augmented Reality, Zhili Zhang, Wang Chao, Long Yong, Shaodi Wang

Journal of System Simulation

Abstract: Aiming at the problems that virtual training system was not convenient and was only performed in a single operation at present, a dual-machine collaborative system based on mobile augmented reality was designed. A portable augmented reality system was developed on the Unity3D platform with Tango technology. The photon server and LAN architecture were built on the basis. The client was built on the mobile platform of Lenovo PHAB2 Pro, and the co-simulation on dual-machine was implemented. Resultof the simulation proved the feasibility of combining augmented reality with photon server, and provided a set of practical development solutions for …

Parameter Optimization Analysis For Double Reheat Units Based On Particle Swarm Optimization, Wenfeng Fu, Haiwen Chen, Lanjing Wang

Journal of System Simulation

Abstract: The thermodynamic system parameter optimization was established for double reheat ultra-supercritical units. Taking a 660MW unit as an example, some vital parameters including feedwater enthalpy rise distribution, feedwater temperature, reheat steam pressure, number of feedwater heaters and main steam parameter were analyzed based on particle swarm optimization. The result shows the unit thermal efficiency can be further improved by optimizing apparatus interface parameters. The second reheat pressure has more influence on the unit thermal efficiency than the first reheat pressure. When adding the number of feedwater heaters, low pressure heater is a better choice for improving unit thermal efficiency. …

Locally Weighted Learning Control For Dynamic Restricted Manipulators, Wang Gang, Tairen Sun, Shengpei Ding

Journal of System Simulation

Abstract: This paper proposes a locally weighted learning control law for a manipulator with state and input constraints and modeling uncertainties. By visualizing the control input as an extended state, the control problem is converted into control design for a state-constraint uncertain nonlinear system. Barrier Lyapunov functions are introduced into a backstepping procedure and a locally weighted learning control is designed, which ensures the exponential convergence of the barrier functions to a small neighborhood of zero and then guarantees satisfaction of system constraints and the tracking error convergence. The control feasibility and effectiveness is validated by theoretical analysis and …

Encoder Fault Detection And Fault Tolerant Control Of 3d Stage Wire System Based On Fdre, Li Wei, Zhenfu Ge, Fuyuan Shen, Jianxing Gong

Journal of System Simulation

Abstract: Aimed at the problem of encoder fault of 3D stage wire system, combined with LADRC, two kinds of fault tolerant control strategiesare presented based on fault diagnosis reliability evaluation (FDRE) to prevent the spread of fault effects in the system and causing accidents. Based on this, the soft and hard smooth transition soft redundant switching mechanism is designed. The simulation results show that the control strategy can ensure encoder fault detection in a timely and reliable manner, and effectively improve the safety and reliability of 3D stage wire system.

Quantity Optimization Of Aircraft Ground Deicing Equipment Based On Flight Dynamics, Bin Chen, Liwen Wang

Journal of System Simulation

Abstract: Flight delays and deicing equipment parameter optimization questions were studied aiming at two kinds of typical airport. The formation mechanism of deicing flight delay queue was studied, and the flight delay queue model was proposed corresponding to the departure dynamics of triangle and parabolic shape function. An optimization model of deicing nozzle quantity demand for two typical flight departure dynamics was established aiming at minimizing the flight delay and deicing cost. The nozzle quantity demand optimization model was simulated and verified using deicing flight dynamic data of Beijing International Airport and Harbin Taiping Airport. Simulation results are close to …

Extending Lifetime Of Sensor Networks Based On Sleep-Scheduled Routing Algorithm, Zhuojin Pan, Stuart D., Luo Zhen, Yang Hua

Journal of System Simulation

Abstract: In order to minimize energy consumption of sensor nodes in wireless sensor networks, this paper presents an Energy Efficient Sleep-Scheduled Tree-Based Routing Protocol (EESSTBRP) that modifies the chain formation in PEGASIS to create a set of paired and unpaired nodes in the network based on a distance and sensing range threshold. The paired nodes switch between active and sleep modes so as to remove redundant data and save battery power. To minimize energy consumption as nodes switching between the modes, this scheme considers the transitioning to be done based on a point of near depletion of the nodes’ residual …

Cloud-End Cooperative Manufacturing And Simulation Application In Electrical Equipment Industry, Ruijie Shi, Zou Ping, Xike Wu, Liu Gang, Gao Chen, Junyuan Zhang, Li Lin, Guo Li

Journal of System Simulation

Abstract: Electrical equipment manufacturing industry hopes to achieve cloud-end cooperative manufacturing of the whole industry chain services by means of national network e-commerce cloud platform. On the basis of explaining the role of simulation in cloud-end cooperative manufacturing, this paper analyses the practical problems faced by enterprises in electrical equipment industry to realize cloud-end cooperative manufacturing, and presents effective solutions and overall solution; all kinds of the necessary application services are provided, which coincide with the actual requirement of electrical equipment manufacturing industry; and the research results of the key problems for realization about them are introduced. The overall industry …

Modeling And Simulation Of Missile Trajectory Based On Practical Sampling, Wu Shuai, Xiaohua Zhou, Lili Wang, Xingzhong Yao

Journal of System Simulation

Abstract: Aiming at the problem of lacking the proper simulation method for missile trajectory in combat simulation training, this paper analyzes the limitations of the 6D and 3D simulation models, proposes a method of trajectory simulation with missile kinematics model and history measured data, and taking an air-to-surface ballistic missile with midcourse-terminal guidance as an example, describes the model construction process in detail. Through the verification, validation and simulation experiments, it shows that this method can simulate various types of missile trajectory with high confidence on both sides of “red and blue”, which has an important reference meaning for missile …

Adaptively Resampling 3d Mesh Models Based On Editable Features, Jiajia Dai, Lipeng Fan, Mingyong Pang

Journal of System Simulation

Abstract: We propose a hybrid algorithm for adaptively resampling 3D triangulations by user-defined editable features. The method parameterizes a 3D mesh model into 2D parameter plane, and the geometric properties of the original model is calculated and represented on a planar domain. According to a constructed geometric image of the original model and user-defined editing information, the method creates a global density function for the resampled model. The sampling density function is employed to control distribution of samples in the 2D parameter domain. The method uses centroidal Voronoi tessellation technique to further optimize local distribution of the sampled points. The …

Design And Implementation Of Asd Children’S Cognitive Education System Based On Unity3d, Xuejing Gu, Kaifeng Zhang, Yucheng Guo, Zhiliang Wang

Journal of System Simulation

Abstract: ASD (autism spectrum disorder) is a broad sense of autism. In order to improve cognitive deficits of children with ASD, promote cognitive generalization in ASD children, an education system was designed using Unity3D. The built-in physical engine of Unity3D was used to create a game environment which conformed to the physical laws of the real world by simulating the effects of gravity, buoyancy and collision. The Agent technology and state machine were used to realize the representation and control of virtual scene. Camera and face detection technology were used to realize facial imitative cognitive training. The preliminary test showed …

Design Of Adaptive Predictive Controller For Superheated Steam Temperature Control, Qian Hong, Yuqing Feng

Journal of System Simulation

Abstract: An adaptive model predictive controller for overheating steam temperature control of thermal power plants is designed, which is based on the control object with large delay, large inertia, nonlinearity and strong time-varying properties. Through the on-line identification and control of different models, compared with predictive controllers in a general model, in terms of adjusting the superheat steam temperature, the adjusting time can be shortened drastically, the overshoot can be reduced or even eliminated, and the dynamic performance is improved greatly when applying in adaptive model predictive controller. The results show that the adaptive model predictive controller, because of its …

Thai Language Names, Place Names And Organization Names Entity Recognition, Hongbin Wang, Hongkui Gao, Shen Qiang, Yantuan Xian

Journal of System Simulation

Abstract: Named entity recognition in Thai language is aimed to identify the names of a person, a locality,an organization or an institution,and so on. Due to the complexity of Thai word formation method and grammar rules, to solve this problem, the idea of the approach proposed is to treat the task of named entity recognition in Thai language as labeling the sign of a series of words in Thai sentence. Given the characteristics of Thai language itself, certain features in the context of the samples in the Thai entity recognition corpus are extracted to train the hidden Markov model and …

2-Local Derivations On Virasoro Algebras, Shavkat Ayupov, Bakhtiyor Yusupov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

The present paper is devoted to study 2-local derivations on infinite-dimensional Lie algebras over a field of characteristic zero. We show that every derivation on Virasoro algebra is inner and prove that all 2-local derivations on this algebra is a derivation. We give an example of infinite-dimensional Lie algebra with a 2-local derivation which is not a derivation.

An Updated Review Of Atmospheric Mercury, Seth N. Lyman, Irene Cheng, Lynne E. Gratz, Peter Weiss-Penzias, Leiming Zhang

Chemistry and Biochemistry Faculty Publications

The atmosphere is a key component of the biogeochemical cycle of mercury, acting as a reservoir, transport mechanism, and facilitator of chemical reactions. The chemical and physical behavior of atmospheric mercury determines how, when, and where emitted mercury pollution impacts ecosystems. In this review, we provide current information about what is known and what remains uncertain regarding mercury in the atmosphere. We discuss new ambient, laboratory, and theoretical information about the chemistry of mercury in various atmospheric media. We review what is known about mercury in and on solid- and liquid-phase aerosols. We present recent findings related to wet and …

Signal Control Strategy And Simulation For Vehicles Alternatively Passing Construction Area Of Two-Lane Road, Haipeng Shao, Binbin Zheng, Linxu Long

Journal of System Simulation

Abstract: The construction area of the two-lane roads can form the road bottlenecks easily, leading to the capacity of the road reducing. Aiming to keep the vehicle passing the construction area safely and efficiently, we added the strategy of signal control in the construction area. We built a suitable signal control model for the construction area of the two-lane road. By using the simulation software of Vissim, we established the related simulation models. By using the control variable method to change the simulation parameters and by changing the arrival traffic and speed, we got the influences and rules to the …

Semantic Value-Driven 3d Upright Posture Figure Model Transformation, Yangfu Ren, Yuanyuan Pu, Xu Dan, Wenhua Qian

Journal of System Simulation

Abstract: In medical equipment, clothing design, film production and computer games, 3D human body model is an indispensable element, but directly obtaining it by means of scanning the human body model does not directly apply in many environments, so we need to moderate deformation model according to the environment. The operation difficulty of the model of deformation is considered, and the deformation effect is achieved. For studying the 3D human body model deformation problem, the deformation of semantic driven model is introduced. Semantic values of height, leg length and shoulder height were obtained by measuring the position of joint points …