Physical Sciences and Mathematics Commons^™

A Strategy To Identify Event Specific Hospitalizations In Large Health Claims Databases, Joshua Lambert, Harpal Sandhu, Emily Kean, Teenu Xavier, Aviv Brokman, Zachary Steckler, Lee Park, Arnold Stromberg

Statistics Faculty Publications

Background: Health insurance claims data offer a unique opportunity to study disease distribution on a large scale. Challenges arise in the process of accurately analyzing these raw data. One important challenge to overcome is the accurate classification of study outcomes. For example, using claims data, there is no clear way of classifying hospitalizations due to a specific event. This is because of the inherent disjointedness and lack of context that typically come with raw claims data.

Methods: In this paper, we propose a framework for classifying hospitalizations due to a specific event. We then tested this framework in …

Pronounced Changes In Thermal Signals Associated With The Madoi (China) M 7.3 Earthquake From Passive Microwave And Infrared Satellite Data, Feng Jing, Lu Zhang, Ramesh P. Singh

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Thermal variations in surface and atmosphere observed from multiple satellites prior to strong earthquakes have been widely reported ever since seismic thermal anomalies were discovered three decades ago. These thermal changes are related to stress accumulation caused by the tectonic activities in the final stage of earthquake preparation. In the present paper, we focused on the thermal changes associated with the 2021 Madoi M 7.3 earthquake in China and analyzed the temporal and spatial evolution of the Index of Microwave Radiation Anomaly (IMRA) and the Index of Longwave Radiation Anomaly (ILRA) based on 8-year microwave brightness temperature (MWBT) and 14-year …

Segmentation Of Infant Brain Using Nonnegative Matrix Factorization, Norah Saleh Alghamdi, Fatma Taher, Heba Kandil, Ahmed Sharafeldeen, Ahmed Elnakib, Ahmed Soliman, Yaser Elnakieb, Ali Mahmoud, Mohammed Ghazal, Ayman El-Baz

All Works

This study develops an atlas-based automated framework for segmenting infants' brains from magnetic resonance imaging (MRI). For the accurate segmentation of different structures of an infant's brain at the isointense age (6-12 months), our framework integrates features of diffusion tensor imaging (DTI) (e.g., the fractional anisotropy (FA)). A brain diffusion tensor (DT) image and its region map are considered samples of a Markov-Gibbs random field (MGRF) that jointly models visual appearance, shape, and spatial homogeneity of a goal structure. The visual appearance is modeled with an empirical distribution of the probability of the DTI features, fused by their nonnegative matrix …

A Course In Data Science: R And Prediction Modeling, Adam Kapelner

Open Educational Resources

This is a self-contained course in data science and machine learning using R. It covers philosophy of modeling with data, prediction via linear models, machine learning including support vector machines and random forests, probability estimation and asymmetric costs using logistic regression and probit regression, underfitting vs. overfitting, model validation, handling missingness and much more. There is formal instruction of data manipulation using dplyr and data.table, visualization using ggplot2 and statistical computing.

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 …

Uav Formation Recovery And Consistency Simulation Based On Improved Potential Field, Ning Wang, Jiyang Dai, Jin Ying

Journal of System Simulation

Abstract: Aiming at the problems of multi-UAV formation collision avoidance, formation recovery and the consistency of position and velocity convergence, a distributed cooperative formation control algorithm based on the improved potential field principle and consistency theory is proposed. The static obstacle model, UAV particle model and the second-order system dynamic model are established; the coordination potential field function with coordination factors and communication weights is defined, which can achieve the control objectives of collision avoidance and formation recovery; on the basic consistency protocol, the formation center reference vector, expected speed and speed stabilization items are introduced to achieve the convergence …

Multi-Objective Optimization Configuration Of Agv System Based On Response Surface And Nsga-Ii, Jianlin Fu, Guofu Ding, Jian Zhang, Haifan Jiang, Peipei Guo

Journal of System Simulation

Abstract: Automated guided vehicle(AGV) system plays an important role in the production flexibility and efficiency in manufacturing systems. Due to the dynamic and stochastic characteristics of AGV system with many variables, its optimal configuration is relatively complex. A method combining system simulation, mathematical analysis and multi-objective optimization is proposed to optimize the configuration of AGV system. The discrete event simulation is used to simulate the operation of AGV system, the sensitivity analysis is used to separate design variables, the factorial experiments and response surface methods are used to build the fitting multi-objective optimization mathematical model, and the non-dominated sorting genetic …

Study On The Scale Characteristics Of Permeability Of Tpms Porous Materials, Tong Wu, Qinghui Wang, Zhijia Xu

Journal of System Simulation

Abstract: Triply Periodic Minimal Surface (TPMS) has been widely used in the design of porous materials, however, there is insufficient research on the scale characteristics of permeability. Four commonly used TPMS units are chosen as the research object, based on the introduction of their mathematical models and porosity control methods, a numerical simulation model based on CFD (computational fluid dynamics) is established; TPMS units and cubic porous structures with different porosities are analyzed, the quantitative correlation between their scales and permeability is clarified, i.e., within the selected scale range, the permeability of various TPMS units and cubic porous structures is …

Triangular Mesh Boolean Operation Method For Finite Element Analysis, Yufei Guo, Kang Zhao, Yongqing Hai

Journal of System Simulation

Abstract: To shorten the cycle of finite element analysis (FEA), an adaptive triangular mesh Boolean operation method for finite element analysis is proposed. The ADT (alternating digital tree) data structure is applied to the intersection calculation of triangular meshes, which improves the efficiency of the intersection calculation of Boolean operations. A sphere packing algorithm and a node addition/deletion algorithm are used to remesh some remeshing regions, which ensures the efficiency of the method and the high-quality of remeshed meshes. An improved octree background grid is used to record and smooth the size field, which can generate size-adaptive meshes. The size …

Cellular Automata Model Of Mixed Traffic Flow Composed Of Intelligent Connected Vehicles’ Platoon, Yangsheng Jiang, Sichen Wang, Kuan Gao, Meng Liu, Zhihong Yao

Journal of System Simulation

Abstract: To solve the existing cellular automata model of automatic-manual driving that does not consider the behavior of vehicle platoon, a cellular automata model of mixed traffic flow with the intelligent connected vehicles platoon is proposed, and the characteristics of mixed traffic flow are analyzed. The existing car-following behaviors in mixed traffic flow are analyzed. Based on the characteristics of the car-following behaviors, the cellular automata rules of human-driven vehicles (HDV), adaptive cruise control (ACC), and cooperative adaptive cruise control (CACC) are developed, respectively. Based on the numerical simulation experiments, the mixed traffic flow characteristics and congestion conditions are analyzed …

Water Body Extraction From High Resolution Remote Sensing Images Based On Fused Visual Word Bags, Xin Wang, Mingjun Xu, Jian Xiao, Lizhong Xu

Journal of System Simulation

Abstract: Aiming at the problem that water body extraction is easily influenced by shadow or light in high resolution remote sensing images, an improved algorithm based on fusion of visual word bags is proposed. Based on the deep analysis of the characteristics of remote sensing water body targets, a spectral feature extraction approach is designed. To enhance the description ability of water body targets, a novel visual word bag fusion model based on local binary pattern and spectral feature is constructed. Based on the proposed visual word bag fusion model, a water body target classifier is presented. …

Study On Building Fire Evacuation Path Planning Based On Improved Ant Colony Algorithm, Jiangtao Liang, Huiqin Wang

Journal of System Simulation

Abstract: Aiming at the problem of dynamic planning of evacuation paths in comprehensive building fires, with the shortest escape time required for evacuees as the goal, considering the impact of fire products and crowd density on the evacuation speed of personnel, an evacuation path planning model based on improved ant colony algorithm is constructed. A evacuation network data model composed of an obstacle vertex grid is established, the inspiration function of the ant colony algorithm and the deadlock processing strategy are improved, the explosion operator in the fireworks algorithm is introduced to optimize the ant path, and a comprehensive building …

Teaching-Learning-Based Optimization Algorithm For Permutation Flowshop Scheduling, Qiwen Zhang, Bin Zhang

Journal of System Simulation

Abstract: A multi-classes teaching-learning-based optimization (MCTLBO) algorithm is proposed for the permutation flowshop scheduling problem (PFSP) by combining continuous algorithm with discrete strategy. An improved nawaz enscore ham (NEH) population initialization method based on permutation mutation is adopted, which takes into account the quality and diversity of initial solutions. In the teaching stage, discrete adaptive teaching with duplicate removal is introduced to avoid meaningless teaching processes. A new self-learning strategy based on Levy flight is added, and the self-learning in discrete stage is simulated by variable neighborhood search. Learner phase and class communication are combined to improve the efficiency of …

Supply Chain Delivery Model And Simulation Based On Product Experience, Genshang Xing, Fang Lu, Shushan Li, Dingti Luo

Journal of System Simulation

Abstract: With the higher demand of consumers for delivery time of products purchased online, it is becoming more important for retailers to determine the delivery time of products based on product experience and market position. By constructing a supply chain delivery model under the three channel rights structure, the impact of product experience on the optimal delivery time, the retailer’s decision mode selection considering the delivery time and the supply chain profit after delivery are analyzed, and the correctness and reliability of the model are verified by numerical simulation. Research shows that the optimal product delivery time of retailers …

Murals Super-Resolution Reconstruction With The Stable Enhanced Generative Adversarial Network, Jianfang Cao, Yiming Jia, Minmin Yan, Xiaodong Tian

Journal of System Simulation

Abstract: Aiming at the problems of low resolution and unclear texture details of ancient murals, which led to insufficient viewing of murals and low research value, a stable enhanced super-resolution generative adversarial networks (SESRGAN) reconstruction algorithm is proposed. Based on the generative adversarial network, the generative network uses dense residual blocks to extract mural features, and uses the visual geometry group (VGG) network as the basic framework of the discriminating network to determine the authenticity of the input mural, and introduces perception loss, content loss and penalty loss to jointly optimize the model. Experimental results show that, compared with other …

Design Of Variable Stiffness Energy Storage Walking Assist Hip Exoskeleton And Simulation Of Assistance Effect, Bingshan Hu, Ke Cheng, Sheng Lu, Hongliu Yu

Journal of System Simulation

Abstract: Passive energy storage walking assist exoskeleton makes full use of the human’s own energy, reducing energy consumption when walking. Aiming at the present passive energy storage walking assist exoskeleton adopts fixed stiffness joint, a passive variable stiffness energy storage walking assist hip exoskeleton is designed, on the base of joint energy flow characteristics in the process of people walking and the change of stiffness characteristics. The human-exoskeletons coupling model is established, and the optimal stiffness that minimizes the power consumption of the human body walking on a flat surface, as well as the total metabolism and the main thigh …

Robot Path Planning Based On Bidirectional Aggregation Ant Colony Optimization, Xiangyang Deng, Limin Zhang, Wei Fang, Miao Tang

Journal of System Simulation

Abstract: Path planning is a key theoretical issue of the autonomous mobile robot technology. This paper utilizes an improved grid method to establish environment model, which involves a new priori advantage azimuth structure that includes two parts of the primary dominant grid cell and the subprime grid cell. It improves the pheromone mark ant colony optimization algorithm by putting forward a novel pheromone update strategy based on secondary path cognitive method, which is called bidirectional guidance strategies. It repeats an alternation of the starting point and the target point in each new round of iteration. The experimental results show that …

Research On Parametric Modeling And Deformation Method Of Human Muscle, Na Ni, Kunjin He, Xincheng Zhu, Zhengming Chen

Journal of System Simulation

Abstract: Due to the volume preserving constraint of human muscle in the deformation process, and the lack of three-dimensional multi-angle representation of muscle motion, a parametric modeling and deformation method of human muscle is proposed. Based on MRI (magnetic resonance imaging) data, the external contour line is extracted from the slice image generated by MRI data to construct a three-dimensional muscle model; muscle features are defined hierarchically, and the mapping relationship between semantic parameters is established to realize the volume preserving deformation of muscle; by establishing a vector-valued dynamic fourth-order differential equation, the feature curve dynamically simulates the process …

State Prediction Of Poverty Alleviation Objects Based On Hmm And Multidimensional Data, Jun He, Sunyan Hong, Yifang Zhou, Shikai Shen, Muquan Zou

Journal of System Simulation

Abstract: In order to solve the problems of inaccurate prediction of poverty, poverty reduction and poverty returen, and the difficulty in identifying the key factors affecting the state transition, 8 key features and 22 observed states are extracted from the poverty reduction basic data and multi-industry data. The relationship between observed state and implied state is constructed, and the hidden markov model (HMM) of poverty alleviation is established. Data of a deep poverty county for three consecutive years are used as samples for parameter training, test experiment and result verification. The results show that the method has a strong …

Simulation Of Navigation Process Based On Nonlinear Observer, Zhiwei Wang, Jizong Hu, Fengjie Wang, Jie Huang

Journal of System Simulation

Abstract: In order to solve the problem that the scope of using thetraditional observers is limited by assumptions, in the process of establishing the observer, a parameter projection relationship is designed and added to the observer to keep it under the condition of not being constrained by the assumptions. It is semi-globally stable, and the estimation process is more direct, which makes the parameter estimation process under nonlinear conditions converge faster. The simulation results show that the computational complexity of the nonlinear observer is reduced by nearly 80% compared with the multiplicative extended Kalman filter. The experimental results show that …

A Visual Analytics Of Urban Traffic Events Using Social Media Data, Xiangping Wu, Lijun Ping, Dongshi Xu

Journal of System Simulation

Abstract: Traffic text data in social media can supplement traffic flow information, for which a visual analysis method for traffic events is proposed. A text processing model is designed to process the social media data and extract the description information of traffic event. The vector representation of road node attributes is learned based on graph embedding algorithm, and a road similarity model is estbalished. A prediction model of the traffic event is built based on the road similarity and the kernel density model. An interactive visual analysis system is designed to carry out visual analysis. Though traffic …

Research On Visual Inspection Algorithm Of Crimping Appearance Defects For Wiring Harness Terminals, Bingan Yuan, Mingen Zhong, Jingxin Ni

Journal of System Simulation

Abstract: Aiming at the low efficiency and high missing rate of wiring harness terminals, an image detection method based on machine vision is proposed. The characteristic parameters of five typical defects in three main parts of wiring harness terminals are analyzed and defined. Tthe algorithms of extracting positioning datum, segmenting inspected-parts adaptively, extracting the defect features and calculating the characteristic parameters are designed respectively, and the defects criterions are given. The experimental results show that the algorithms are suitable for single defect and multi-class defects, both the miss detection rate and the false positiveness rate are low. The accuracy and …

Phased Array Radar Doa Estimation Simulation System Designed With Interactive Control, Fan Yu, Dongqi Luo, Binqiang Si, Jihong Zhu

Journal of System Simulation

Abstract: For the problem of simulation, evaluation and verification of phased array radar the direction of arrival (DOA) estimation of phased array radar, the modeling and evaluation of phased array radar DOA estimation is discussed. A real-time simulation system based on interactive control is designed. The simulation system can be used to model and simulate the interactive target & environment, phased array and target detection efficiency evaluation model. The signal generation, free space propagation, echo signal acquisition, signal processing and other processes can be simulated during the detection of real-time flying target, and the effect of DOA estimation can be …

Research On Immersive Virtual Reality Interactive System For Flow Visualization, Shijian Xu, Dan Zhao, Chengyu Su, Fupan Wang, Xiaorong Zhang, Fang Wang, Yadong Wu

Journal of System Simulation

Abstract: Aiming at the problem of low interaction efficiency due to the lack of depth information in the current desktop flow visualization application based on the two-dimensional display interaction environment, virtual reality technology is introduced to design and implement an immersive flow visualization system with diversified interaction methods. Based on the gaze and gesture interaction technology, the system designs and implements gesture-based navigation methods and three-dimensional interactive widgets based on user requirements, as well as immersive interactive panels based on user gaze and gestures. We designed and implemented an immersive interactive management method based on visual scenes and a visual …

Within‑Marsh And Landscape Features Structure Ribbed Mussel Distribution In Georgia, Usa, Marshes, William K. Annis, Elizabeth A. Hunter, John M. Carroll

United States Geological Survey: Staff Publications

Ribbed mussels, Geukensia demissa, are marsh fauna that are used in coastal management and restoration due to the ecosystem services they provide. Ribbed mussel restoration efforts may be improved with a greater understanding of the environmental drivers of ribbed mussel distribution at multiple spatial scales to predict areas where restoration could be successful. This study sought to estimate the effects of within-marsh (4 m) and landscape (500 m) factors on ribbed mussel distribution. Ribbed mussel densities were surveyed at 11 sites along the coast of Georgia, USA, and overlaid with spatial data for within-marsh factors (elevation, distance to marsh …

The Mitogenome Relationships And Phylogeography Of Barn Swallows (Hirundo Rustica), Gianluca Lombardo, Nicola Rambaldi Migliore, Giulia Colombo, Marco Rosario Capodiferro, Giulio Formenti, Manuela Caprioli, Elisabetta Moroni, Leonardo Caporali, Hovirag Lancioni, Simona Secomandi, Cristina Cereda, Valerio Carelli, Lauren Gillespie, Yang Liu, Yosef Kiat, Alfonso Marzal, Cosme López-Calderón, Javier Balbontín, Timothy Mousseau, Piotr Matyjasiak, Anders Pape Møller, Et. Al.

Faculty Publications

The barn swallow (Hirundo rustica) poses a number of fascinating scientific questions, including the taxonomic status of postulated subspecies. Here, we obtained and assessed the sequence variation of 411 complete mitogenomes, mainly from the European H. r. rustica, but other subspecies as well. In almost every case, we observed subspecies-specific haplogroups, which we employed together with estimated radiation times to postulate a model for the geographical and temporal worldwide spread of the species. The female barn swallow carrying the Hirundo rustica ancestral mitogenome left Africa (or its vicinity) around 280 thousand years ago (kya), and her descendants …

Nanopore Structure And Surface Roughness In Brittle Tectonically Deformed Coals Explored By Atomic Force Microscopy, Zhang Ningyuan, Yao Suping

Coal Geology & Exploration

The pore structure of coal is the key to coalbed methane (CBM) exploration and exploitation, and coal mining safety. Compared to primary coals, tectonically deformed coals (TDCs) have stronger heterogeneity and are of great importance in coal reservoir study. Here, the pore structure and surface roughness of brittle TDCs were obtained with atomic force microscopy (AFM) and NanoScope Analysis and Gwyddion software. The results show that tectonic deformation generally promotes the pore development in brittle TDCs, but the extent of tectonic impact varies greatly among different brittle TDCs. As a result, two stages in brittle TDCs were identified: weak brittle …

Preliminary Investigation Of Uranium Resource Evaluation Method Based On Natural Gamma Logging Data：A Case Study Of The Pengyang Uranium Deposit In Ordos Basin, Yu Reng’An, Sun Dapeng, Zhou Xiaoxi, Deng Fan, Si Qinghong, Hu Yongxing

Coal Geology & Exploration

“Coal and uranium exploration” and “oil and uranium exploration” are current research hotspots. Using logging data of coal and oilfield drilling to further evaluate uranium resources remains a difficult problem. Taking the Pengyang uranium deposit in the Ordos Basin as an example, this article explores the method of evaluating uranium resources based on natural gamma logging data. According to the remarkable features of the natural gamma anomaly response in the sandstone-type uranium reservoirs in the study area, the natural gamma logging regression model of the quantitative gamma logging value of the uranium deposit in the Pengyang area was studied by …