Engineering Commons^™

Design And Realization Of 6-Dof Parachuting Simulation Training System, Xiaoguang Zhou, Peng Zhu, Yuanyuan Zhang, Huan Lu, Yuan Zhou

Journal of System Simulation

Abstract: Aiming at restoring the 6-DOF motion process of each stage during parachuting, a 6-DOF parachuting simulation training system is designed and implemented. The architecture of the simulator is designed, and the realization of the sub-systems such as the motion calculation, 6-DOF motion platform, control loading system, virtual reality scene, somatosensory system and management console is explained. Compared with the same type of parachute simulator, this system has introduced a 6-DOF motion platform which can drive the trainees to simulate the various postures of parachuting. It can also help the trainees master the control methods of parachute and enhance the …

A High Spectral-Efficiency Maritime Very-High-Frequency Communication Technology And Simulation, Xinyu Dou, Xiaohui Chen, Dequn Liang, Bin Lin

Journal of System Simulation

Abstract: Marine communications cannot follow the development route on land of developing high frequency resources and high spectral-efficiency modulation technologies in 5G and 6G high-speed communication. The data rate and spectral-efficiency of maritime communications are low and are difficult to be improved. A high spectral-efficiency maritime very-high-frequency (VHF) communication technology based on multi-carrier time-delay overlapping modulation (MC-TDOP) is proposed. The core is delaying the subcarriers in turn and directly overlapping them in time domain. The orthogonality between the subcarriers can be neglected, thus the spectral-efficiency can be further enhanced from the fundamental information modulations. The results show that the proposed …

Simulation Method Of Virtual Human Pose Optimization Based On Vr Peripherals, Muqing Wang, Lei Zhang, Xiumin Fan, Xiaomeng Luo, Wenmin Zhu

Journal of System Simulation

Abstract: The commonly used VR peripheral is the position tracker worn on the operator body and is not very convenient. Focus on the problem, a visual sensor combination-based scheme is proposed to realize the simple and real-time unmarked virtual human driven simulation. On the basis of the parameterized human model SMPL, by minimizing the objective function of multiple error terms, the driven accuracy of the virtual human is improved, and the fitted human body model conforming to the operator form and posture is calculated and the ergonomic evaluation is realized. The module is verified by a case of evaluation in …

Multi-Person Interactive Globe System Based On Ar Technology, Yiling Sun, Yi Chen, Guihua Shan, Xiaoxing Li

Journal of System Simulation

Abstract: The characteristic of multi-source, high-dimensional, time-varying and massive of the Earth big data is difficult to be understood and analyzed. Aiming at this problem and for the science popularization needs, an AR-based multi-person interactive globe system is proposed and implemented. A system architecture integrating AR technology is proposed to realize the seamless overlay combination effect of the virtual information and the physical globe. A data visualization display scheme is designed to realize the visualization of the Earth big data in three-dimensional space. A lightweight multi-person multi-terminal collaboration mechanism is proposed to improve the practicality and interestingness of the system. …

Multi-Agent Simulation For Online Fresh Food Autonomous Delivery, Miaojia Lu, Chengyuan Huang, Jing Teng

Journal of System Simulation

Abstract: Autonomous delivery can solve the last-mile delivery problems of low efficiency, high manual cost, and potential safety hazard. The autonomous delivery of the online fresh food in urban communities is discussed and a data-driven agent-based platform with the actual spatial-temporal demand is built. Three kinds of agents including the autonomous vehicles, customers, and distribution center and the simulation environment based on the actual road network are construct. To achieve the objectives of the minimum total operating costs and maximum customer satisfaction, the different static and dynamic order dispatch strategies and the route planning strategies with the principle of …

Denoising Algorithm Based On Multi-Feature Non-Local Mean Filtering For Monte Carlo Rendered Images, Kai Yang, Chunyi Chen, Xiaojuan Hu, Haiyang Yu

Journal of System Simulation

Abstract: Aiming at the rendering noise in Monte Carlo synthesized images induced by the low light-path sampling rate, a denoising algorithm based on the multi-feature non-local-mean filtering is proposed. The gradient image of the scene's albedo information is calculatedwith the canny operator, and a guided filter together with the said gradient image is employed to prefilter the normal vector image. The structural similarity of the sub-blocks in the prefiltered normal vector image is calculated and the improved weights of the non-local mean filter are computed according to the logarithmic value of the reciprocal of the structural similarity. The improved …

Multi-Uavs 3d Path Planning Method Based On Random Strategy Search, Sen Zhang, Mengyan Zhang, Jingping Shao, Jiexin Pu

Journal of System Simulation

Abstract: In view of the difficulty of the traditional path planning method without energy consumption constraints to meet the emergency rescue requirements in the complex mountain operation environment, a three-dimensional path planning algorithm for multi-UAVs is proposed based on LSTM-DPPO(long short-term memory-distributed proximal policy optimization) framework. The LSTM long and short-term memory neural network is used to extract the important characteristic state information sequence of the multiple unmanned aerial vehicles in their respective flight process. After repeated iteration and updating, an optimal network parameter model is obtained. Combined with the energy consumption, the optimal 3D detection path is generated. …

Simulation Of Multi-Layer Ship Evacuation System Based On Improved A* Algorithm, Dun Meng, Zhuo Hu, Huajun Zhang

Journal of System Simulation

Abstract: Aiming at the low efficiency of emergency evacuation at sea, an emergency evacuation system based on improved A* algorithm is proposed. Based on the network flow model, the traversal mode of the adjacency node is used to complete the path search, and the influence of the path personnel density and path obstacles is added to the calculation of the cost, which makes the algorithm more practical. In order to improve the efficiency of the algorithm, the node optimization of the network is carried out, and a multi-path optimal scheme is proposed in the case of single layer with multiple …

Image Center Layout Optimization Method Based On Improved Genetic Algorithm, Zhijie Li, Haoqi Shi, Changhua Li, Jie Zhang

Journal of System Simulation

Abstract: Aiming at the layout optimization methods of image center being influenced by the subjective factors and low level of automation, a method of combining systematic layout planning(SLP) with the improved genetic algorithm is proposed. The layout scheme generated by SLP improves the initial population of the genetic algorithm and increases the diversity of the initial population. In order to improve the efficiency of optimization, the improved algorithm updates the crossover probability and mutation probability adaptively according to the evolution stages and the fitness value of the individuals. On the basis of the layout area model and multi-objective optimization mathematical …

Airport Flight Transit Support Time Collaborative Planning Modeling Based On Stn, Bin Chen, Yue Liu, Yalei Yang

Journal of System Simulation

Abstract: Under the constraint of resources, the collaborative planning of airport flight transit support time is one of the effective methods to improve airport operation efficiency. Based on Simple Temporal Network (STN), a planning model of flight transit support time is established. Based on the temporal decoupling, the shortest path matrix simplification, and the distance graph solving of STN task model considering resources, the method of collaborative planning of flight transit support time for airport considering resources is obtained. The comparison results of the simulation and the actual data show that STN task model considering resources can optimize the airport …

Vehicle Detection Method Based On Multi Scale Feature Fusion, Yin Wang, Feixiang Wang, Qianlai Sun

Journal of System Simulation

Abstract: Vehicle detection is the important research content and hotspot in the intelligent transportation. Aiming at the low detection accuracy and poor small-scale recognition effect of the traditional vehicle detection algorithm, an improved detection method based on YOLOv4(you only look once v4) is proposed to improve the detection performance of small target vehicles in traffic scenes. By redesigning the YOLOv4 network, the MobileNetv2 deep separable convolution module is used to replace the traditional convolution, and the convolutional block attention module (CBAM) attention module is integrated into the feature extraction network to ensure the detection accuracy of the model and reduce …

A Hybrid Algorithm Based On Seeker Optimization Algorithm And Salp Swarm Algorithm For Pid Parameters Optimization, Shaomi Duan, Huilong Luo, Haipeng Liu

Journal of System Simulation

Abstract: Aiming at the premature convergence of seeker optimization algorithm(SOA) during optimizing the global problems, a new SOA-SSA hybrid algorithm based on seeker optimization algorithm and salp swarm algorithm (SSA) is proposed.The SOA-SSA algorithm is based on a double population evolution strategy, in which some individuals of the population are evolved by seeker optimization algorithm and the rest are evolved from salp swarm algorithm. The individuals in SOA and SSA both employ an information sharing mechanism to realize the coevolution. These strategies increase the diversity of the population and avoid the premature convergence. The experimental results show that …

Application Of Improved Q Learning Algorithm In Job Shop Scheduling Problem, Yejian Zhao, Yanhong Wang, Jun Zhang, Hongxia Yu, Zhongda Tian

Journal of System Simulation

Abstract: Aiming at the job shop scheduling in a dynamic environment, a dynamic scheduling algorithm based on an improved Q learning algorithm and dispatching rules is proposed. The state space of the dynamic scheduling algorithm is described with the concept of "the urgency of remaining tasks" and a reward function with the purpose of "the higher the slack, the higher the penalty" is disigned. In view of the problem that the greedy strategy will select the sub-optimal actions in the later stage of learning, the traditional Q learning algorithm is improved by introducing an action selection strategy based on the …

Visual Inspection Model Of Uav Cluster Based On Improved Pigeon Flock Hierarchy, Qi Chen, Haoyang Cui

Journal of System Simulation

Abstract: Aim at UAV being vulnerable to the environmental interference and the low efficiency of the traditional single-person-UAV model in the transmission line inspection, a visual inspection model for the power line by UAV is proposed based on the improved pigeon flock hierarchy. The initial landmark point of the UAV is generated based on GPS coordinates of the aircraft-carrying vehicle and the tower to be inspected, and the movement trajectory is planned. The return point of the UAV is used to update the initial landmark of onward UAV, which realizes the dynamic handover between the work-exchanging UAV, and the landmark …

Design Of Interactive Simulated Water Gun Fire Fighting Training System Based On Steam Vr, Cheng Lu, Xuesheng Jin

Journal of System Simulation

Abstract: In order to save the fire fighting training resources and increase the immersion and experience of VR training, an interactive simulated water gun fire fighting training system based on Steam VR is designed. By using the Hall sensors and signal conversion circuit boards to collect and transmit the signal of the simulated water gun, and by using the Unity3D engine combined with the VIVE head-mounted display to build and present VR fire scene. The gun is controlled through C# programming to complete the interaction with the virtual fire scene. The system is evaluated by a post-questionnaire survey …

Application Of Observability In Performance Evaluation Of Photosynthesis Model, Hongnai Gao, Lijiang Fu, Qian Xia, Ya Guo

Journal of System Simulation

Abstract: The photochemical reaction of photosynthesis involves a variety of physiological substances that cannot be directly measured. By modeling the control system, the state of these physiological substances can be es-timated based on the chlorophyll fluorescence, but the reliability of the state estimation is not given in all the reference documents. In response to this problem, based on the photochemical reaction kinetic model, the observability of the nonlinear system is introduced to evaluate the reliability of the state estimation. Aiming at the existing observability methods lacking the direct comparability due to the different dimensions of the components of different states, …

Fuzzy Super-Twisting Second Order Sliding Mode Trajectory Tracking Control For Robotic Manipulator, Baolin Du, Dachang Zhu, Yihua Pan

Journal of System Simulation

Abstract: A fuzzy super-twisting second order sliding mode control method is proposed for the uncertainties of the model error and external disturbance on the trajectory tracking accuracy of robotic manipulator. Based on the dynamic model of the robotic, a new non-singular terminal sliding mode manifold is designed, and an improved super-twisting algorithm is used to design the second order sliding mode controller. In order to solve the problem that the matching disturbance can only be compensated under the condition of the known disturbance boundary in the sliding mode control, the fuzzy logic algorithm is used to carryout the online compensation …

Research On Fire Emergency Evacuation Simulation Based On Cooperative Deep Reinforcement Learning, Lingjia Ni, Xiaoxia Huang, Hongga Li, Zibo Zhang

Journal of System Simulation

Abstract: The fire accident is a major threat to the public safety, in which the high temperature, toxic and harmful gases seriously interfer the selection of the evacuation routes. Deep reinforcement learning is introduced into the research of emergency evacuation simulation, and a cooperative double deep Q network algorithm is proposed for the multi-agent environment. A fire scene model that changes dynamically over time is established to provide the real-time information on the distribution of the dangerous areas for the evacuation. The independent agent neural networks are integrated and the multi-agent unified deep neural network is established to realize the …

Training Thinner And Deeper Neural Networks: Jumpstart Regularization, Carles Riera, Camilo Rey, Thiago Serra, Eloi Puertas, Oriol Pujol

Faculty Conference Papers and Presentations

Neural networks are more expressive when they have multiple layers. In turn, conventional training methods are only successful if the depth does not lead to numerical issues such as exploding or vanishing gradients, which occur less frequently when the layers are sufficiently wide. However, increasing width to attain greater depth entails the use of heavier computational resources and leads to overparameterized models. These subsequent issues have been partially addressed by model compression methods such as quantization and pruning, some of which relying on normalization-based regularization of the loss function to make the effect of most parameters negligible. In this work, …

Monofacial Vs Bifacial Solar Photovoltaic Systems In Snowy Environments, Koami Soulemane Hayibo, Aliaksei Petsiuk, Pierce Mayville, Laura Brown, Joshua M. Pearce

Electrical and Computer Engineering Publications

There has been a recent surge in interest in the more accurate snow loss estimates for solar photovoltaic (PV) systems as large-scale deployments move into northern latitudes. Preliminary results show bifacial modules may clear snow faster than monofacial PV. This study analyzes snow losses on these two types of systems using empirical hourly data including energy, solar irradiation and albedo, and open-source image processing methods from images of the arrays in a northern environment in the winter. Projection transformations based on reference anchor points and snowless ground truth images provide reliable masking and optical distortion correction with fixed surveillance cameras. …

Single-Pass Inline Pipeline 3d Reconstruction Using Depth Camera Array, Zhexiong Shang, Zhigang Shen

Department of Construction Engineering and Management: Faculty Publications

A novel inline inspection (ILI) approach using depth cameras array (DCA) is introduced to create high-fidelity, dense 3D pipeline models. A new camera calibration method is introduced to register the color and the depth information of the cameras into a unified pipe model. By incorporating the calibration outcomes into a robust camera motion estimation approach, dense and complete 3D pipe surface reconstruction is achieved by using only the inline image data collected by a self-powered ILI rover in a single pass through a straight pipeline. The outcomes of the laboratory experiments demonstrate one-millimeter geometrical accuracy and 0.1-pixel photometric accuracy. …

Officers: Operational Framework For Intelligent Crime-And-Emergency Response Scheduling, Jonathan David Chase, Siong Thye Goh, Tran Phong, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

In the quest to achieve better response times in dense urban environments, law enforcement agencies are seeking AI-driven planning systems to inform their patrol strategies. In this paper, we present a framework, OFFICERS, for deployment planning that learns from historical data to generate deployment schedules on a daily basis. We accurately predict incidents using ST-ResNet, a deep learning technique that captures wide-ranging spatio-temporal dependencies, and solve a large-scale optimization problem to schedule deployment, significantly improving its scalability through a simulated annealing solver. Methodologically, our approach outperforms our previous works where prediction was done using Generative Adversarial Networks, and optimization was …

A Unified View Of A Human Digital Twin, Michael Miller, Emily Spatz

Faculty Publications

The term human digital twin has recently been applied in many domains, including medical and manufacturing. This term extends the digital twin concept, which has been illustrated to provide enhanced system performance as it combines system models and analyses with real-time measurements for an individual system to improve system maintenance. Human digital twins have the potential to change the practice of human system integration as these systems employ real-time sensing and feedback to tightly couple measurements of human performance, behavior, and environmental influences throughout a product’s life cycle to human models to improve system design and performance. However, as this …

One-Stage Blind Source Separation Via A Sparse Autoencoder Framework, Jason Anthony Dabin

Dissertations

Blind source separation (BSS) is the process of recovering individual source transmissions from a received mixture of co-channel signals without a priori knowledge of the channel mixing matrix or transmitted source signals. The received co-channel composite signal is considered to be captured across an antenna array or sensor network and is assumed to contain sparse transmissions, as users are active and inactive aperiodically over time. An unsupervised machine learning approach using an artificial feedforward neural network sparse autoencoder with one hidden layer is formulated for blindly recovering the channel matrix and source activity of co-channel transmissions. The BSS sparse autoencoder …

A Self-Learning Intersection Control System For Connected And Automated Vehicles, Ardeshir Mirbakhsh

Dissertations

This study proposes a Decentralized Sparse Coordination Learning System (DSCLS) based on Deep Reinforcement Learning (DRL) to control intersections under the Connected and Automated Vehicles (CAVs) environment. In this approach, roadway sections are divided into small areas; vehicles try to reserve their desired area ahead of time, based on having a common desired area with other CAVs; the vehicles would be in an independent or coordinated state. Individual CAVs are set accountable for decision-making at each step in both coordinated and independent states. In the training process, CAVs learn to minimize the overall delay at the intersection. Due to the …

Local Learning Algorithms For Stochastic Spiking Neural Networks, Bleema Rosenfeld

Dissertations

This dissertation focuses on the development of machine learning algorithms for spiking neural networks, with an emphasis on local three-factor learning rules that are in keeping with the constraints imposed by current neuromorphic hardware. Spiking neural networks (SNNs) are an alternative to artificial neural networks (ANNs) that follow a similar graphical structure but use a processing paradigm more closely modeled after the biological brain in an effort to harness its low power processing capability. SNNs use an event based processing scheme which leads to significant power savings when implemented in dedicated neuromorphic hardware such as Intel’s Loihi chip.

This work …

Un-Fair Trojan: Targeted Backdoor Attacks Against Model Fairness, Nicholas Furth

Theses

Machine learning models have been shown to be vulnerable against various backdoor and data poisoning attacks that adversely affect model behavior. Additionally, these attacks have been shown to make unfair predictions with respect to certain protected features. In federated learning, multiple local models contribute to a single global model communicating only using local gradients, the issue of attacks become more prevalent and complex. Previously published works revolve around solving these issues both individually and jointly. However, there has been little study on the effects of attacks against model fairness. Demonstrated in this work, a flexible attack, which we call Un-Fair …

Collaborative Design And Simulation Integrated Method Of Civil Aircraft Take-Off Scenarios Based On X Language, Pengfei Gu, Lin Zhang, Zhen Chen, Junjie Ye

Journal of System Simulation

Abstract: For the large and complex products, the current traditional model-based systems engineering (MBSE) method of the integrated implementation of multiple modeling and simulation languages and platforms for system design and simulation verification can not ensure the efficient and accurate feedback of system design to realize the quick design optimization. X language, a new generation of integrated modeling and simulation language based on complex systems and supporting MBSE, is used to realize the integrated modeling and simulation on cross-domain subsystems of civil aircraft for the take-off scenarios. From the demand analysis of the take-off process of civil aircraft, the system-level …

Cross Level Switching Technology For Multi-Resolution Model Of Complex Products, Wei Li, Wenjia Zhang, Heming Zhang

Journal of System Simulation

Abstract: In the R&D of complex products, different design stages have different design goals and different simulation tasks, which need different resolution complex products simulation models. The models and interfaces for the multi-resolution characteristics are defined and thus the resolution control mechanism is studied. The description mechanisms for the system structure status and model resolution state are established separately, the control mechanism for the system resolution is proposed, and a cross level switching technology is sorted out. The experimental results show that the method can effectively solve the problem of model resolution switching, which ensures the simulation accuracy, improves …

A Cyber-Physical Integrated Modeling Method Oriented For Motion Simulation Of Complex Systems, Wenzheng Liu, Heming Zhang

Journal of System Simulation

Abstract: The traditional virtual modeling of motion simulation lacks the dynamic modeling of cyber subsystems and physical subsystems in complex systems. The advantages of the traditional kinematic virtual modeling and cyber calculation are combined, and aiming at the problem that the accuracy and real-time property of motion simulation cannot meet the actual industrial manufacturing requirements, a cyber physical integrated modeling method for the motion simulation of complex systems is proposed. The inconsistency between real robotic driving and virtual robot motion is solved, which is verified by a case study of mechanical arm motion control. A virtuality-reality mapping platform for complex …