Numerical Analysis and Scientific Computing Commons^™

Multi-Stage Multi-Agv Path Planning With Walk Under Shelves For Robotic Mobile Fulfillment Systems, Teng Li, Peipei Ding, Jinfang Liu

Journal of System Simulation

Abstract: Aiming at the problem of increasing travel time due to turning and obstacle avoidance in robotic mobile fulfillment systems(RMFS) with large-scale multi-AGV path planning, a path planning model with the shortest task completion time is established. A path planning model considering no-load AGV that can pass through the shelf is proposed, and the model is solved by an improving A* algorithm. The AGV operation stage is divided, an turning penalty value is introduced into the A* algorithm to reduce the turning times, and the obstacle avoidance priority with the obstacle avoidance waiting time is set. The simulation results show …

Design And Simulation Of Ts Fuzzy Based Cooperative Control Of Missile Formation, Yexin Zhang, Yu Cheng, Hongyan Yan, Xuwei Fan, Xu Zhang, Yi Tian

Journal of System Simulation

Abstract: Aiming at the requirement of cooperative operation of multi-missile formation, a cooperative control algorithm of multi-missile formation based on Takagi-Sugeno(TS) fuzzy control theory is proposed.The flight speed, trajectory angle and trajectory deflection angle of the missile are taken as parameters in the leader-follower mode missile formation flying system.The local asymptotically stable controller is designed by using the systemlocal linearization of multiple groups of equilibrium pointsduring the whole flight process.Through the expert experience method,the membership function and fuzzy rules for the system are designedwith TS fuzzy theory, and the whole multi-missile cooperative control system is completed and the stability …

Fiesta And Shock-Driven Flows, Brian E. Romero

Mechanical Engineering ETDs

In this study, the interaction of a shock with various gas and particle interfaces is analyzed through simulations using a new, GPU capable, multi-species flow solver, FIESTA (Fast, Interface Evolution, Shocks, and Transport in the Atmosphere), de- veloped for this research. The cases studied include the interaction between a shock and i) a two-dimensional (2D), circular cloud of a dense gas; ii) a 2D curtain of a dense gas; iii) a three-dimensional (3D) cylinder of a dense gas, and iv) a 3D curtain of solid particles.

In simulations of a 2D gas curtain and a 3D gas column, the curtain …

Neutron Interferometry Using A Single Modulated Phase Grating, Ivan J. Hidrovo Giler

LSU Master's Theses

Neutron grating interferometry provides information on phase and small-angle scatter in addition to attenuation. Previously, phase grating moiré interferometers (PGMI) with two or three phase gratings have been developed. These phase-grating systems use the moiré far-field technique to avoid the need for high-aspect absorption gratings used in Talbot-Lau interferometers (TLI) which reduce the neutron flux reaching the detector. We demonstrate through simulations a novel phase grating interferometer system for cold neutrons that requires a single modulated phase grating (MPG) for phase-contrast imaging, as opposed to the two or three phase gratings in previously employed PGMI systems. We compare the MPG …

Robust Sensor Design For The Novel Reduced Models Of The Mead-Marcus Sandwich Beam Equation, Ahmet Aydin

Masters Theses & Specialist Projects

Novel space-discretized Finite Differences-based model reductions are proposed for the partial differential equations (PDE) model of a multi-layer Mead-Marcus-type beam with (i) hinged-hinged and (ii) clamped-free boundary conditions. The PDE model describes transverse vibrations for a sandwich beam whose alternating outer elastic layers constrain viscoelastic core layers, which allow transverse shear. The major goal of this project is to design a single boundary sensor, placed at the tip of the beam, to control the overall dynamics on the beam.

For (i), it is first shown that the PDE model is exactly observable by the so-called nonharmonic Fourier series approach. However, …

Order Constraints In Optimal Transport, Fabian Lim, Laura Wynter, Shiau Hong Lim

Research Collection School Of Computing and Information Systems

Optimal transport is a framework for comparing measures whereby a cost is incurred for transporting one measure to another. Recent works have aimed to improve optimal transport plans through the introduction of various forms of structure. We introduce novel order constraints into the optimal transport formulation to allow for the incorporation of structure. We define an efficient method for obtaining explainable solutions to the new formulation that scales far better than standard approaches. The theoretical properties of the method are provided. We demonstrate experimentally that order constraints improve explainability using the e-SNLI (Stanford Natural Language Inference) dataset that includes human-annotated …

Contours Of Virtual Enfreakment In Fighting Game Characters, Sercan Sengun, Peter Mawhorter, James Bowie-Wilson, Yusef Audeh, Haewoon Kwak, D. Fox Harrell

Research Collection School Of Computing and Information Systems

Characters in fighting videogames1 such as Street Fighter V and Tekken7 typically reveal a phenomenon that we define as virtual enfreakment: their bodies, costumes, and fighting styles are exaggerated (1) in a manner that emphasizes perceived exoticism and (2) to enable them to be easily visually and conceptually distinguishable from one another. Here, using both quantitative and qualitative methods, including crowd-sourced surveys and analyses of game mechanics, we report on the contours of virtual enfreakment in those games. We specifically examine differences in character design across gender, national-origin, and skin-color lines. Disappointingly but not surprisingly, we find racism and sexism …

Robustness And Personalization In Federated Learning: A Unified Approach Via Regularization, Achintya Kundu, Pengqian Yu, Laura Wynter, Shiau Hong Lim

Research Collection School Of Computing and Information Systems

We present a class of methods for robust, personalized federated learning, called Fed+, that unifies many federated learning algorithms. The principal advantage of this class of methods is to better accommodate the real-world characteristics found in federated training, such as the lack of IID data across parties, the need for robustness to outliers or stragglers, and the requirement to perform well on party-specific datasets. We achieve this through a problem formulation that allows the central server to employ robust ways of aggregating the local models while keeping the structure of local computation intact. Without making any statistical assumption on the …

Data-Driven Retail Decision-Making Using Spatial Partitioning And Delineation Of Communities, Ming Hui Tan, Kar Way Tan

Research Collection School Of Computing and Information Systems

Urbanisation is resulting in rapid growth in road networks within cities. The evolution of road networks can be indicative of a city's economic growth and it is a field of research gaining prominence in recent years. This paper proposes a framework for spatial partition of large scale road networks that produces appropriately sized geospatial units in order to identify the type of community they serve. To this end, we have developed a three-stage procedure which first partitions the road network using Louvain method, followed by outlining the boundary of each partition using Uber H3 grids before classifying each partition using …

Positive Rate-Dependent Action Potential Prolongation By Modulating Potassium Ion Channels, Candido Cabo

Publications and Research

Pharmacological agents that prolong action potential duration (APD) to a larger extent at slow rates than at the fast excitation rates typical of ventricular tachycardia exhibit reverse rate dependence. Reverse rate dependence has been linked to the lack of efficacy of class III agents at preventing arrhythmias because the doses required to have an anti-arrhythmic effect at fast rates may have pro-arrhythmic effects at slow rates due to an excessive APD prolongation. In this report we show that, in computer models of the ventricular action potential, APD prolongation by accelerating phase 2 repolarization (by increasing I_Ks) and decelerating …

Research And Simulation Of Internet Of Vehicles Task Offloading Based On Mobile Edge Computing, Peng Cheng, Wenzhu Zhang, Shuhan Xie, Zixuan Yang

Journal of System Simulation

Abstract: In order to use the computing resources of edge devices to provide high-quality services, a joint resource allocation and task offloading mechanism is designed for the Internet of Vehicles architecture based on mobile edge computing. In the mechanism, the original problem is decomposed into two sub-problems of resource allocation and offloading decision. The original problem is simplified into the resource allocation of maximizing system capacity, and the initial offloading set is obtained through the proportional resource allocation algorithm; the above problem is solved by the joint offloading decision-making and resource allocation mechanism. The stable experimental results are obtained …

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 …

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 …

An Unsupervised Deep Neural Network For Image Fusion, Peipei Zhou, Xinglin Hou

Journal of System Simulation

Abstract: Due to the low dynamic range of camera, can not be expressed in the different region of the high dynamic scene a single-exposure image. An unsupervised depth neural network is constructed to fuse the multi-exposure images into a high dynamic image. Based on the VGG-Net, encoding and decoding sub-networks are designed. Guided by the structural similarity of the images before and after fusion, a loss function suitable for image fusion is designed by introducing the weight factors based on the local image information, and the valid information of the different input images is given consideration. Compared with the …

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 …

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 …

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. …

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 …