Engineering Commons^™

Adaptive Multi-Scale Place Cell Representations And Replay For Spatial Navigation And Learning In Autonomous Robots, Pablo Scleidorovich

USF Tampa Graduate Theses and Dissertations

Place cells are one of the most widely studied neurons thought to play a vital role in spatial cognition. Extensive studies show that their activity in the rodent hippocampus is highly correlated with the animal’s spatial location, forming “place fields” of smaller sizes near the dorsal pole and larger sizes near the ventral pole. Despite advances, it is yet unclear how this multi-scale representation enables navigation in complex environments.

In this dissertation, we analyze the place cell representation from a computational point of view, evaluating how multi-scale place fields impact navigation in large and cluttered environments. The objectives are to …

Study Into The Sensitity Of The G-H Method To Blending Distance, Cory Goates, Doug Hunsaker

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A numerical lifting-line method (implemented in an open-source software package) is presented which can accurately estimate the aerodynamics of wings with arbitrary sweep, dihedral, and twist. Previous numerical lifting-line methods have suffered from grid convergence challenges and limitations in accurately modeling the effects of sweep, or have relied on empirical relations for swept-wing parameters and have been limited in their application to typical wing geometries. This work presents novel improvements in accuracy, flexibility, and speed for complex geometries over previous methods. In the current work, thin-airfoil theory is used to correct section lift coefficients for sweep, providing a more general …

Investigation Of Polymer Nanocomposites With Silicon Dioxide Fillers As Helium Cooled High-Temperature Superconducting Cable Dielectrics, Jordan Thomas Cook

Theses and Dissertations

In this thesis, three polymer nanocomposite configurations are fabricated for investigation as dielectrics in helium-cooled high-temperature superconducting (HTS) cables. Polyimide, polyamide, and polymethyl methacrylate are utilized as host polymers. The composite samples are synthesized through an in situ process, dispersing silicon dioxide nanoparticles throughout the polymer hosts. Fourier transform infrared spectroscopy and scanning electron microscopy were employed to validate the synthesis of each composite configuration. Thin film samples of each configuration were also tested for their dielectric strength at both room (300 K) and cryogenic (92 K) temperatures. When going from room to cryogenic temperatures, all materials demonstrated a significant …

Film-Terminated Fibrillar Microstructures With Improved Adhesion On Skin-Like Surfaces, Gabriela Moreira Lana, Xuan Zhang, Christian Müller, René Hensel, Eduard Arzt

Chemical and Biochemical Engineering Faculty Research & Creative Works

Adhesives for interaction with human skin and tissues are needed for multiple applications. Micropatterned dry adhesives are potential candidates, allowing for a conformal contact and glue-free adhesion based on van der Waals interactions. In this study, we investigate the superior adhesion of film-terminated fibrillar microstructures (fibril diameter, 60 μm; aspect ratio, 3) in contact with surfaces of skin-like roughness (Rz 50 μm). Adhesion decays only moderately with increasing roughness, in contrast to unstructured samples. Sinusoidal model surfaces adhere when their wavelengths exceed about four fibril diameters. The film-terminated microstructure exhibits a saturation of the compressive force during application, implying a …

Calorific Value Calculation For Natural Gas -Hydrogen Blend, Utkarsha Chavan

Other resources

This is a sample calculation for the natural gas -hydrogen blend for two different gas samples. The composition of two natural gas samples is provided in two sheets. The calorific value is calculated for a blend with a molar composition of hydrogen varying from 0 to 20%. Along with calorific value (MJ/m3), Wobbe index (MJ/m3) and specific gravity are also calculated.

Feasibility Assessment Of Warm Mix Asphalt In Arkansas, Mohammad Najmush Sakib Oyan

Student Theses and Dissertations

The future of Warm Mix Asphalt (WMA) technologies is promising in the U.S. However, the Arkansas Department of Transportation (ARDOT) does not have any specific guidelines to implement them in the field. This research aims to provide necessary baseline data for WMA as a proof of concept. In this study, three ARDOT approved Performance Grade (PG) binders namely PG 64-22, PG 70-22, and PG 76-22 were investigated. Each of these binders was obtained from two different sources. They were modified by varying doses of four selected additives: Sasobit®, Advera®, Evotherm®, and Rediset®. Additionally, four different types of aggregates (sandstone, limestone, …

Review On Ecological Construction Of Domestic High-Performance Parallel Application Software In Post Moore Era, Chunye Gong, Jie Liu, Weimin Bao, Dongmei Pan, Xinbiao Gan, Shengguo Li, Xuguang Chen, Tiaojie Xiao, Bo Yang, Ruibo Wang

Journal of System Simulation

Abstract: Domestic high performance computing (HPC) system is world-leading and the system chip architectures are in varied forms. The system operation relied on National Supercomputing Center has a good development trend. Several technical key points of domestic high-performance parallel application software are word-leading and the application supporting environment is developing fast. But industrial software and team building are facing huge challenges. In post Moore era, based on the progress of human civilization, it is necessary to promote the ecological development of parallel application software, and from the viewpoint of software products the industrial software must be aim foreign commercial software …

Research On Improved Feature Pyramid Algorithm Integrating Border Supervision Strategy, Hong Sun, Yuelan Ling, Yuxiang Zhang

Journal of System Simulation

Abstract: Aiming at the inaccurate boundary division in semantic segmentation and the existence of multi-scale targets, an improved feature pyramid algorithm fused with boundary supervision strategies is proposed. By fusing the boundary supervision strategy and the improved feature pyramid algorithm, the problems of inaccurate boundary division and the existence of multi-scale targets are sloved respectively, and an attention mechanism is added in the upsampling process to further improve the segmentation effect. The experimental results show that the algorithm can reach 58.69% and 78.59% MIOU (mean intersection over union) indicators on the Camvid and PASCAL VOC2012 data sets respectively, and has …

Real-Time Scheduling Method For Railway Passenger Station Operations Based On Digital Twin, Bisheng He, Peng Chen, Hongxiang Zhang, Gongyuan Lu, Chunhui Zhang

Journal of System Simulation

Abstract: To improve the operation scheduling of railway passenger stations and reduce the train delays, digital twin technology is used to establish a railway passenger station operation model. Through real-time data acquisition, based on the operation time prediction of random forest method, operation simulation and decision-making, a real-time scheduling method of railway passenger station operations based on digital twin is proposed, and applied in a real railway passenger station. The experimental results show that the method can effectively forecast and simulate the actual operation. Three kinds of digital twin scheduling rules have been used, which can reduce the delay time …

A Quantum Krill Herd Fusion Algorithm And Its Application, Zengxi Feng, Jintong Zhao, Shiyan Li, Yalong Yang, Haiyue Chen, Cong Zhang

Journal of System Simulation

Abstract: Aiming at the defects of krill herd algorithm and quantum evolutionary algorithm, a quantum krill herd fusion algorithm (QKH) is proposed. The algorithm uses double-chain real numbers to encode the krill position, which can speed up the convergence speed, and avoids the randomness and complexity of quantum observations. The dynamically adjusted quantum krill herd rotation phase update strategy improves the convergence accuracy, and the efficiency of determining the quantum rotation phase. The introduction of an improved quantum full interference crossover strategy can prevent the fusion algorithm from falling into a local optimum, and can improve the optimization efficienal. The …

Control Of Quadruped Robot Based On Impedance And Virtual Model, Chikun Gong, Xunwei Wu, Lipeng Yuan

Journal of System Simulation

Abstract: In order to improve the motion stability of quadruped robot, a control method based on impedance and virtual model is proposed. The force-based impedance control method is used to control the leg swing phase to realize the more accurate trajectory tracking and leg compliance control. The virtual model control method is used to control the support phase to realize the attitude control of the robot body and the stable walking of the quadruped robot. Combined with the lateral stride strategy and the yaw angle control strategy based on virtual model, a robot anti-lateral impact control method is proposed, which …

Adaptive Crowd Evacuation Simulation Model Based On Bounded Rationality Constraints, Liqiang Zhao, Mengqian Guo, Shuixiong Tang, Jinjin Tang

Journal of System Simulation

Abstract: To effectively improve the accuracy of evacuation simulation of a crowded environment, an adaptive crowd evacuation simulation model based on social force model and bounded rationality constraints is proposed. The desired direction and desired speed of the self-driving force that affects the pedestrian movement in the traditional social force model is improved. The adaptive calculation is used in the optimization of direction and speed of pedestrian in an obstacle avoidance situation. The rational route decision mechanism is proposed to describe the route selection behavior of pedestrians in a congested state more accurately. The results show that the proposed model …

Research On Modeling And Simulation Of Optimization Deployment For Cooperative Localization By Multiple Detection Sensors In Complex Environment, Gongguo Xu, Libing Cai, Peibing Du, Yu Liu

Journal of System Simulation

Abstract: Aiming at the difficulty of accurate cooperative localization by multi-sensor network in complex environment, an optimization deployment method is proposed. The GDOP evaluation index of target positioning accuracy is constructed based on PCRLB. The influence of undulating terrain, clutter jamming and illumination on sensor detection and positioning ability in complex environment is analyzed. An optimization deployment model of multi-sensor cooperative location is built and the intelligent optimization algorithm is used to quickly solve the model. Simulation results show that the proposed method can effectively improve the cooperative localization ability of multi-sensor network and can guide the multi-sensor cooperative …

Tactical Maneuver Strategy Learning From Land Wargame Replay Based On Convolutional Neural Network, Jiale Xu, Haidong Zhang, Donghai Zhao, Wancheng Ni

Journal of System Simulation

Abstract: Aiming at collecting the high valuable knowledge of action decisions in "man-in-the-loop" wargame's replay data, a method of using convolutional neural network to learn the tactical maneuver strategy model from the replay data of wargame is proposed. In this method, the tactical maneuver strategy is modeled as a classification problem of making a good choice from the target candidate locations under the influence of current situation. The key factors affecting commander's decision-making are summarized, and the basic situation features are defined, which are composed of seven attributes such as "maneuverability range and observation range". The feature dataset with positive …

Weighted Local Complexity Invariance For Time Series Classification, Yitong Li, Xiaotao Liu, Jing Liu, Kai Wu

Journal of System Simulation

Abstract: Aiming at the misclassification of existing algorithms for long or unevenly distributed time series, the local complexity information is extracted and weighted local complexity-invariant distance (WLCID) is proposed, which includes the local complexity representation model and the weighted global complexity integration model. Sliding window is used to split up time series, and combined with the complexity-invariant distance, the local complexity information can be extracted. As to the class representation model, the integration weights are quantified with the normalized cumulative between-class distance, with the perspective that the subsequence contributes more greatly with larger between-class distance. Compared with other …

A K-Modes Clustering Method Based On Maximal Information Coefficient Data Preprocessing, Mingmei Li, Chenglin Wen, Shaolin Hu

Journal of System Simulation

Abstract: The existing k-modes clustering method ignores the weak correlation of variable attributes, which often results in poor clustering performance in practical applications. A new k-modes clustering method that includes the weak correlation of attributes is proposed. Maximum information coefficient (MIC) is introduced to measure the correlation of variable attributes in the data set. The obtained MIC value is merged with the original distance to establish a new measurement method containing weak attribute correlation information to enhance the completeness of related information of variable attributes, and a more refined k-modes clustering method is established. Three different data sets are used …

Research On Satellite Navigation Confrontation Deduction Model For Wargame System, Runqing Yang, Xi Wu

Journal of System Simulation

Abstract: Following the increasing reliance on space-based time-space metric of information warfare, satellite navigation confrontation becomes the major combat operation of competing for superiority in space-based position, navigation, and timing. Aiming at building a satellite navigation operation deduction model, on the basis of analyzing the relevant research, the navigation information environment computing model and the navigation deduction operation simulation model are designed, and the way to realize the visualization of navigation information environment of the wargame system and a substitution of high-resolution simulation computing model low-resolution probability effect model are explored, which support the pre-war planning and wartime evaluation …

Wind Power Primary Frequency Regulation Simulation Based On Wind Speed Prediction Model, Zhenyu Zhao, Xu Ma, Geriletu Bao

Journal of System Simulation

Abstract: To furtherly improve the accuracy of wind speed prediction, considering the coupled comprehensive features of data internal structure external influencing factors, and the characteristics of wind turbines power, a BP-ARIMA combined prediction model is constructed and the wind speed of wind farms is simulated. Compared with the actual data, the high prediction accuracy of the model is verified. Bases on the curve of typical power characteristic of wind turbine, the optimal configuration of energy storage device capacity and the stability of wind turbine are considered, and the MATLAB-SIMULINK platform is applied to simulate the primary frequency regulation of …

Multi-Sensory Fusion Method For Power Transformer Virtual Assembly, Xuqiang Shao, Haowei Zhang, Xiaohua Feng

Journal of System Simulation

Abstract: Virtual assembly technology is to truly restore the equipments and physical scenarios. In the real world, people can interact with the physical world through visual, auditory, tactile and other sense organ. Aiming at the existing virtual assembly system being limited the single sense human-computer interaction mode, so a multi-sense fusion information interaction method is proposed to improve the sense of immersion and operability. An improved AABB Octree bounding box collision detection algorithm of large size diffidence component to be assembled is proposed, which can greatly reduce the amount of calculation and improve the calculation accuracy. The experimental result verifies …

Reinforcement-Learning-Based Adaptive Tracking Control For A Space Continuum Robot Based On Reinforcement Learning, Da Jiang, Zhiqin Cai, Zhongzhen Liu, Haijun Peng, Zhigang Wu

Journal of System Simulation

Abstract: Aiming at the tracking control for three-arm space continuum robot in space active debris removal manipulation, an adaptive sliding mode control algorithm based on deep reinforcement learning is proposed. Through BP network, a data-driven dynamic model is developed as the predictive model to guide the reinforcement learning to adjust the sliding mode controller's parameters online, and finally realize a real-time tracking control. Simulation results show that the proposed data-driven predictive model can accurately predict the robot's dynamic characteristics with the relative error within ±1% to random trajectories. Compared with the fixed-parameter sliding mode controller, the proposed adaptive controller …

Simulation Research On Aerodynamic Characteristics Of A Miniature Munition, Haisen Wang, Junfang Fan

Journal of System Simulation

Abstract: Aiming at the existing constraints of layout design of miniature munition, a new layout optimization scheme is proposed. Based on the normal layout structure, a three-dimensional aerodynamic model of munition is established, and the aerodynamic hydrodynamics simulation of miniature munition is carried out, and the influence of wing size on static stability of munition is studied. To verify the feasibility of the design scheme, the aerodynamic simulation calculation is carried out, and the lift, drag and pitching moment parameters of miniature munition are obtained through simulated aerodynamic calculation under different flight conditions, and the lift-drag ratio …

Fatigue Detection Method Based On Facial Features And Head Posture, Rongxiu Lu, Bihao Zhang, Zhenlong Mo

Journal of System Simulation

Abstract: Aiming at the of the single fatigue characteristics, low robustness and inability to customize fatigue thresholds for different drivers of fatigue detection methods, a method based on facial features and head posture is proposed. In face detection and face key point positioning HOG feature operator and regression tree algorithm are used. In head posture estimation, head posture Euler angle is estimated by combining the face key points with the coordinate system transformation. In fatigue feature extraction, a deep residual neural network model is established to extract the eye fatigue features, which the eye, mouth aspect ratio and head posture …

Task Allocation Method For Multi-Uav Cooperative Reconnaissance In Complex Environment, Fuzhen Zhang, Yaoqin Zhu

Journal of System Simulation

Abstract: The existing cooperative planning methods of multiple UAVs often carry out path planning and task allocation separatly, which causes the cooperative scheme not being the best in a complex environment. The cost matrix of multi-UAV cooperative reconnaissance on heterogeneous targets is established. Aiming at the various obstacle constraints and the characteristics of UAV motion and track in complex environment, an improved PSO-AFSA is used to solve the single UAV track planning model. Hungarian algorithm is used to complete the cooperative allocation of reconnaissance tasks of UAVs. The simulation results show that the algorithm can make the flying range of …

Simulation Of Emergency Medical Materials Collaborative Distribution Considering Supplier Clustering, Zhe Wang, Hongyuan Shao, Zihao Cong, Wenwen Ma

Journal of System Simulation

Abstract: Aiming at the insufficient local government medical material reserves and low distribution efficiency to public health emergencies, consider supplier clustering a two-stage emergency medical supplies public-private collaborative location and alloation model is designed. In for disaster preparedness, fuzzy clustering algorithm to realize supplier clustering, and a cooperation mechanism with the government is establish realize the joint storage of emergency medical supplies; In the early stage of rescue, relying on the government and various suppliers' material storage and transportation capabilities, a location allocation simulation model to minimize the weighted sum of total logistics cost and demand unsatisfied rate is …

Research On High-Performance Emulation Technology Of Starlink Constellation Based On Cloud Platform, Yuan Liu, Xinyi Xue, Xiaofeng Wang

Journal of System Simulation

Abstract: Network emulation on Starlink constellation is an important verification and evaluation tool for the design and construction of low earth orbit constellations in the future. Aiming at the characteristics of large-scale and complex structure of the Starlink network, a high-performance satellite network emulation system is designed. Based on the distributed network emulation architecture of cloud platform, through the development of STK Engine underlying interface, satellite model library storage optimization and asynchronous message transmission technology, the rapid deployment of Starlink constellation is carried out, and has good scalability. The experimental results show that the proposed method can carry out …

Analysis And Research On End-To-End Optical Image Quality Of Large Aperture Off-Axis Space Telescope, Zhang Ban, Xiaobo Li, Xun Yang, Yuxi Jiang

Journal of System Simulation

Abstract: In order to evaluate the image quality of space on orbit telescope under the comprehensive constraints, the chain calculation analysis method is adopted. The main error factors of the optical image quality degradation are divided into six static errors and two dynamic errors. After calculation, the optical system wavefront aberration under the static loading error is reduced to 0.057λ on average. Under the influence of the static and dynamic errors, the 80% energy concentration of point spread function increases gradually. The method can be used to analyze and evaluate the influence of image stabilization control and precise temperature …

Fabricating 3-Dimensional Human Brown Adipose Microtissues For Transplantation Studies, Ou Wang, Li Han, Haishuang Lin, Mingmei Tian, Shuyang Zhang, Bin Duan, Soonkyu Chung, Chi Zhang, Xiaojun Lian, Yong Wang, Yuguo Lei

Department of Chemical and Biomolecular Engineering: Faculty Publications

Transplanting cell cultured brown adipocytes (BAs) represents a promising approach to prevent and treat obesity (OB) and its associated metabolic disorders, including type 2 diabetes mellitus (T2DM). However, transplanted BAs have a very low survival rate in vivo. The enzymatic dissociation during the harvest of fully differentiated BAs also loses significant cells. There is a critical need for novel methods that can avoid cell death during cell preparation, transplantation, and in vivo. Here, we reported that preparing BAs as injectable microtissues could overcome the problem. We found that 3D culture promoted BA differentiation and UCP-1 expression, and the optimal initial …

Computational Simulations Of The Effects Of Gravity On Lymphatic Transport, Huabing Li, Huajian Wei, Timothy P. Padera, James W. Baish, Lance L. Munn

Faculty Journal Articles

Physical forces, including mechanical stretch, fluid pressure, and shear forces alter lymphatic vessel contractions and lymph flow. Gravitational forces can affect these forces, resulting in altered lymphatic transport, but the mechanisms involved have not been studied in detail. Here, we combine a lattice Boltzmann-based fluid dynamics computational model with known lymphatic mechanobiological mechanisms to investigate the movement of fluid through a lymphatic vessel under the effects of gravity that may either oppose or assist flow. Regularly spaced, mechanical bi-leaflet valves in the vessel enforce net positive flow as the vessel walls contract autonomously in response to calcium and nitric oxide …

Insight Into Nano-Chemical Enhanced Oil Recovery From Carbonate Reservoirs Using Environmentally Friendly Nanomaterials, Ali Ahmadi, Abbas Khaksar Manshad, Jagar A. Ali, Stefan Iglauer, S. Mohammad Sajadi, Alireza Keshavarz, Amir H. Mohammadi

Research outputs 2022 to 2026

The use of nanoparticles (NPs) in enhanced oil recovery (EOR) processes is very effective in reducing the interfacial tension (IFT) and surface tension (ST) and altering the wettability of reservoir rocks. The main purpose of this study was to use the newly synthesized nanocomposites (KCl / SiO₂ / Xanthan NCs) in EOR applications. Several analytical techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscope (SEM) were applied to confirm the validity of the synthesized NCs. From the synthesized NCs, nanofluids were prepared at different concentrations of 100-2000 ppm and characterized using electrical conductivity, IFT, …

A Study Into Proton Exchange Membrane Fuel Cell Power And Voltage Prediction Using Artificial Neural Network, Tabbi Wilberforce, Mohammad Biswas

Mechanical Engineering Faculty Publications and Presentations

Polymer Electrolyte Membrane fuel cell (PEMFC) uses hydrogen as fuel to generate electricity and by-product water at relatively low operating temperatures, which is environmentally friendly. Since PEMFC performance characteristics are inherently nonlinear and related, predicting the best performance for the different operating conditions is essential to improve the system's efficiency. Thus, modeling using artificial neural networks (ANN) to predict its performance can significantly improve the capabilities of handling multi-variable nonlinear performance of the PEMFC. This paper predicts the electrical performance of a PEMFC stack under various operating conditions. The four input terms for the 5 W PEMFC include anode and …