Engineering Commons^™

In Situ Micro-Scale High-Speed Imaging For Evaluation Of Fracture Propagation And Fracture Toughness Of Thermoplastic Laminates Subjected To Impact, H. Wafai, A. Yudhanto, G. Lubineau, M. Mulle, T. Alghamdi, S. T. Thoroddsen, R. Yaldiz, N. Verghese

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Measuring parameters related to each damage mode of composites subjected to impact is very challenging because of the complex damage phenomenology. Here, we developed an experimental methodology for evaluating the micro-scale fracture characteristics of two principal damage modes, i.e., transverse crack and delamination, and providing the corresponding fracture toughness. We demonstrated the capability of the method by comparing and providing additional insights about two materials, namely homopolymer-based (ductile) and copolymer-based (less-ductile) glass/polypropylene thermoplastic composites. We found that (i) transverse crack behavior of both composites is similar as indicated by a small difference in their fracture toughness, (ii) delamination growth in …

Evaluation Of Flow Line Structure Of Hospital With Spatial Cognitive Agent, Yunfeng Wang

Journal of System Simulation

Abstract: Hospital flow line is the result of the mutual adaptation of its spatial layout and business process, which should be regarded as an independent analysis unit in the spatial layout design. Aiming at the phenomenon that the flow lines have the characteristics of both space and flow and are difficult to analyze, a spatial cognitive process of agents is established by introducing structural elements from the spatial syntax analysis as the knowledge coding language of agents. Evaluation indexes of hospital flow line structure based on computational experiment are proposed and implemented. The framework of flow line analysis combining flow …

Evaluation And Modeling Of Visual Fatigue In 3d Display Based On Ecg, Danli Wang, Xinpan Yang, Yue Kang, Haichen Hu

Journal of System Simulation

Abstract: This study investigates and models the correlation between visual fatigue and ECG data by collecting the ECG data of the participants during watching 3D movies, combining with the subjective scores, the reaction time, and the questionnaires before and after the experiment. ECG data of 12 subjects were analyzed in both time and frequency domain. The results showed that subjective score and HR increased with the duration of viewing, while PNN50 decreased. Linear model of subjective score is established, and the R² of model is 0.930. Subjective questionnaires show significant changes in overall visual fatigue, dry eyes and nausea symptoms …

Centroidal Voronoi Tessellation With Local Optimization, Tianyu Ye, Yiqun Wang, Dongming Yan, Junhai Yong

Journal of System Simulation

Abstract: Centroidal Voronoi tessellation is a special geometric structure, which has many applications in various fields such as geographical information system, signal processing, mesh generation/optimization, visualization and so on. Due to the highly non-convex nature of the CVT energy function, the existing methods for computing CVT have several drawbacks, which always trap into local minima. We propose generation optimization and stochastic optimization schemes for further reducing the CVT energy. Experimental results show that the proposed method improves both quality and efficiency compared to the recent approaches.

Satellite Formation Keeping And Its Stability Analysis Based On Artificial Potential Field Method, Shengqing Yang, Wenyu Ye, Yubin He, Yabin Wan

Journal of System Simulation

Abstract: In this paper, a control method of satellite formation keeping is investigated based on artificial potential field. Since the N-body problem doesn’t have analytical solutions, a leader-follower formation is proposed as a restricted N-body problem. The stable structure has infinite possible pairs of coordinates in the inertial frame, therefore the Jacobian matrix of the corresponding error dynamic system at the equilibrium point is unsolvable. By introducing a transformation of coordinates from inertial frame to a specific reference frame, the stability analysis of error dynamic system is only related to the structure of formation. By the reduction of error …

Structure Optimization Analysis Of Distillation Kettle Based On Elastic-Plastic Mechanics, Xiaodong Hu, Liu Ning, Xiangsong Qi, Jianpeng Wang

Journal of System Simulation

Abstract: Based on the analysis of structural strength by elastic mechanics, there is a large stress singularity due to the discontinuity of the equipment structure, which makes the calculation result not consistent with the actual stress of the equipment. According to the actual design and structure of a distillation reactor, based on the theory of elastic-plastic mechanics, through modeling, meshing, loading and constraint analysis, the stress distribution of distillation kettle is analyzed; and the wall thickness and stiffener structure are optimized. The results show that the calculation results are reliable and the design of wall thickness is smaller than the …

Design Of An Energy-Aware Enhanced Cooperative Mac Protocol In Mobile Ad Hoc Networks, Jaeshin Jang, Balasubramaniam Natarajan

Journal of Marine Science and Technology–Taiwan

In this paper, we present a new energy-efficient cooperative MAC protocol, called the e2 BT-COMAC protocol for mobile ad hoc networks, and evaluate its performance. In the proposed MAC protocol, which is an enhanced version of our previous eBT-COMAC protocol, a cross-layer energy-aware strategy for cooperative communication is employed using mobile nodes. Considering a random waypoint mobility model for all mobile nodes, we compare the system throughput and network lifetime of the e2 BT-COMAC protocol with previously proposed cooperative MAC protocols. Using a new metric that is a weighted combination of normalized system throughput and lifetime, we determine optimal values …

Application Of Random Geometric Imperfection Method To Nonlinear Buckling Analysis Of Spherical Shell, Zhixin Xiong, Zhiquan Huang, Xiaochuan Yu

Journal of Marine Science and Technology–Taiwan

This paper focuses on spherical shells with random geometric imperfections under uniform external pressure. An extensive numerical investigation is performed to calculate the buckling loads of perfect and imperfect spherical shells. To discuss the effects of initial geometric imperfections, a finite element analysis model of the perfect spherical shell is considered to obtain its first 60 modes. Then, the consistent imperfect buckling analysis method is applied to analyze the nonlinear stability of the spherical shells with geometric imperfections. The shapes of the shell in the 1st to 20th eigenmode are considered. A lower buckling load is found corresponding to the …

Overview Of Image Segmentation And Registration For Spine Biological Modeling, Juping Gu, Tianyu Cheng, Hua Liang, Jianping Wang, Zhao Jian, Cao Yong

Journal of System Simulation

Abstract: The prevalence of common spinal fractures is high in this day. Spinal image segmentation and registration are the key step and prerequisite of target recognition, biomechanical modeling and finite element analysis. They are also the key technology of noninvasive surgery navigation. Aiming at the problems of spinal image processing, the classical medical image segmentation and registration algorithm is introduced. It also analyzes the defects and prospects of the future development trend of spine image processing. The research results have certain significance for further understanding of spinal medical image processing and promoting the development of rehabilitation therapy for spinal fractures.

Traffic Patterns For Intelligent Vehicles In The Intersection, Wang Jian, Feng Qi, Xiaowei Hu

Journal of System Simulation

Abstract: With the applications of GPS/DR/MM integrated positioning technology and vehicle infrastructure integration technology, three traffic patterns with which intelligent vehicles go through the intersection are put forward. These three traffic patterns include signal lights adaptive traffic pattern, vehicle self-organizing traffic pattern and vehicle infrastructure integration traffic pattern. They can reduce vehicle delay, avoid traffic conflicts, decrease the probability of traffic accidents, improve traffic efficiency and realize the barrier-free accessibility of intelligent vehicles to the intersection. According to the parameters such as vehicles arrival rate, critical velocity and the average vehicle spacing, a clearance movement model and a circular path …

Modeling And Simulation Of Car-Following On Expressway, Yuhan Jia, Jianping Wu, Yiman Du, Mingyu Liu

Journal of System Simulation

Abstract: Aiming at the high-speed following phenomenon on expressways, an improved car-following model is developed in the paper considering variable safety headway distance. The new model is calibrated and validated by the data collected using an instrumented vehicle in Beijing. Stability analysis of the new model is investigated using the control theory method. The numerical simulations are implemented and the result shows good consistency with theoretical study. The new model is integrated into the traffic simulation system of FLOWSIM. Experiment results show that the improved OV model based FLOWSIM can outperform the original system on some specific conditions.

Evaluation Method Of Imminent Battle Situation In Air Combat, Huimin Cao, Anxiang Huang, Lei Xiang

Journal of System Simulation

Abstract: In the state of air combat, the situation change rapidly. Quick and accurate assessment of the current situation and making decisions is the key to the victory of air combat and the preservation of own strength. Based on the specialty of the modern air battle and pelagic operation, this article adds the political factor, the pilot individual actual combat ability, and the formation cooperative tactical task to fight against the single constraint into the evaluation index system. This makes the evaluation more reasonable and comprehensive and closer to the actual combat, so as to provide more accurate basis for …

3d Flight Trajectory Simulation Generator Based On Track Constraints, Shuguang Sun, Cheng Peng

Journal of System Simulation

Abstract: The airborne navigation equipment needs accurate flight trajectory data to test its performance. According to the requirements of the Beidou receivers, considering the constraint of trajectory and flight performance, a flight trajectory generator is designed using iteration like method. The flight trajectory generator can generate the whole trajectory data and the flight parameters of the aircraft based on the actual flight procedures, and display the data and parameters in real time. The whole flight trajectory simulation data from Beijing International Capital Airport to Guangzhou Baiyun International Airport is generated. The result shows that the flight trajectory generator can generate …

Modular Design Method Of Integrated Avionics Simulation System, Mingbo Zhao, Pan Long, Longwei Jiang, Wang Gang, Guangxing Zhao

Journal of System Simulation

Abstract: In the past, there were some problems in the software design for the flight simulation avionics system such as the decentralized structure and the low degree of modularization. Aiming at these problems, a hierarchical, modular integrated avionics system is constructed. The logic part dispersed in each function module is independent to form the integrated logic module. Each task function module and its sub module are responsible for the calculation of the relevant task function algorithm. Modular design is carried out in a deeper level. By dataflow analysis, each module in this design has strong cohesion and weak coupling and …

Rehabilitation Training System Based On Brain Computer Interface, Banghua Yang, Li Bo

Journal of System Simulation

Abstract: Brain-computer interface (BCI) is a new communication and control method. The BCI rehabilitation training system was developed for rehabilitation training of post-stroke patients by using MATLAB and VC++ hybrid programming method. By decoding the EEG signal, the patient's movement intention can be recognized accurately in real time, then the work of the rehabilitation peripheral is triggered to give feedback from the visual, auditory, and tactile. The patient's active rehabilitation is achieved through the system. The system has the characteristics of user-friendly interface, modular algorithm, high online recognition rate; and it can be used as a reference for BCI-based …

Modeling And Simulation Of Inter-City Passenger Travel Service Flow Based On Petri Net, Qipeng Sun, Guo Xin, Ma Fei

Journal of System Simulation

Abstract: On the basis of inter-city passenger travel chain, the inter-city passenger transport service process is studied; the Petri net language is used for establishing and simulating the model of inter-city passenger transport service process based on the Visual Object Net++; and the simulation results are used for verifying the reliability of the established model with the theory of petri net, while the model is transformed into a homogeneous Markov chain with the process. The detailed analysis on the city subway of the inter-city passenger transport service process was carried out. By modeling and simulating, the derived value of …

High-Pass Difference Features Based Image Quality Assessment, Wang Rui, Li Ping, Bin Sheng, Congbin Qiao, Lizhuang Ma, Enhua Wu

Journal of System Simulation

Abstract: Current methods of image quality assessment only can assess the quality of images under the same type of image distortion. In order to fix such weaknesses, this paper is designed based on the image features of natural scene statistics and proposes a new metric method using high-pass filter for detecting features. The approach computes locally the normalized luminance; selects features such as the difference of RGB channels via high-pass filter, image gradient, sharpness, contrast, etc.; and analyzes and gathers features in the metric method trained by logistic regression. Experimental results show that the proposed method can work efficiently under …

Design And Research On Simulation Model Of Limestone-Wet Flue Gas Desulfurization Absorption Tower, Zhang Yue, Han Pu, Zhang Xiang

Journal of System Simulation

Abstract: The mass transfer and chemical reaction processes of wet flue gas desulfurization (FGD) are very complex. It is helpful to improve the operation level of desulfurization site by studying the internal mechanism and establishing a high precision mechanism model. The absorption tower is divided into some regions, and the modeling targets in different regions are determined. The sulfur dioxide absorption region is divided into different heights of the "cell" by the slurry droplet falling distance and exposure time. According to the motion characteristics and mass transfer process, the desulfurization efficiency and pressure drop are calculated, and the absorption efficiency …

Indoor Scene Generation Based On Case-Based Reasoning And Collaborative Filtering, Peihua Song, Jinyuan Jia

Journal of System Simulation

Abstract: To solve the problem of time-consuming and single scene generation in indoor scene generation, we propose an indoor scene generation algorithm based on case-based reasoning and collaborative filtering techniques. The algorithm of functional area division is performed on the two-dimensional room floor plan. Thecase-based reasoning is used to generate 3D scenes; and the collaborative filtering is used to generate diverse indoor scenes. A scene evaluation method based on user feedback information is proposed. Experiments were carried out on the living room and bedroom to generate scenes. The experimental results show that the proposed algorithm is effective. The running time …

Simulation Algorithm Of Streak Tube Multi-Spectral Laser 3d Imaging System, Jingya Cao, Shaokun Han, Wenze Xia, Wang Liang

Journal of System Simulation

Abstract: The streak tube laser three-dimensional imaging system is one of the most promising practical laser imaging systems, because of its high precision, large field of view and high frame frequency. A multispectral imaging simulation algorithm for multi-slit streak tube is proposed based on the research of the multi-spectral imaging. The derivation of the main structural parameters is given. The influence of the number of different detectors on the time resolution and spatial resolution of the system is analyzed. In the model of the simulation system, the laser echo signals of multiple wavelength bands are fed into the photocathode of …

Visualization Platform Of Lightweight Toxic Gases Dispersion, Jinyuan Jia, Xinzhi Zhao, Panjing Li

Journal of System Simulation

Abstract: The sudden accidents usually emit large quantities of toxic gases and harmful pollutants in a short time. It is very necessary and meaningful to predict and visualize the dispersing trend of those toxic gases over Internet as accurate and fast as possible for people to evacuate safely and immediately. We propose a lightweight simulation for air pollution dispersion based on the Gaussian puff model. With this method, we can visualize the procedure of toxic gas dispersing on a webpage in real-time. we can also estimate the pollution of toxic gas dispersion trend and analyze their further pollution effects on …

Hardware-In-The-Loop Simulation Method For Laser Active Imaging Guidance, Zhang Qing, Yijie Li

Journal of System Simulation

Abstract: The system of laser active imaging guidance hardware-in-the-loop simulation is a significant system for testing and validating the capability of laser active imaging guidance and control, it also means a lot in practical applications. The composition of guidance and control system for the laser active imaging aerocraft is analyzed, and the purpose and test flow for the hardware-in-the-loop simulation system are introduced. The integrated project for laser active imaging guidance hardware-in-the-loop simulation system is designed. The functions and elements for the crucial simulation equipment of laser active imaging echo simulator are analyzed; the elements of model composition and …

Improved Dv-Hop Localization Scheme Based On The Best Path Matching Strategy, Qinqin Shi, Xu Qiang, Jianping Zhang

Journal of System Simulation

Abstract: Improvement strategies are provided in view of the fact that the original DV-Hop (Distance, Vector-Hop) method has great error in distance estimation due to the network anisotropy in practical applications and the sensitivity of its location derivation algorithm to the range error. In the distance estimation step, a strategy of computing path similarity parameter is proposed to find out the most similar beacon-beacon path to beacon-node path; in the position calculation step, a modified PSO (Particle Swarm Optimization) algorithm is added after the initial position of an unknown node being derived using Lateration algorithm. Simulation shows that compared with …

Traffic Dynamic Regulation And Control Technology In The Central Area Of Nanning City, Yiman Du, Hongfan Su, Jianping Wu, Chen Yu, Huang Lin, Longfei Liu

Journal of System Simulation

Abstract: As the transportation develops rapidly, the traffic burden increases in downtown areas, especially in the areas of convention center, government building, and business & financial center, which exacerbates traffic congestion nearby. Conventional traffic control measures taken include stagger shifts, congestion charging, and tail number limit. Interests of multi aspects are involved in these measures, which has broad effect. The traffic managers now begin to ameliorate traffic burden by technical methods. A feedback-gate control based regional traffic volume control method was proposed and a microscopic simulation was adopted. This reasearch aims to ameliorate traffic pressure and balance traffic flow through …

Gesture Recognition Method Based On Multi-Feature Fusion, Yuanming Wang, Zhang Jun, Yuanhui Qin, Xiujuan Chai

Journal of System Simulation

Abstract: Aiming at the specific application requirements of command gesture for flight deck, a gesture recognition method based on multi-feature fusion is proposed. The 3D trajectory feature vector and hand sparse representation are established from two aspects of the trajectory and posture based on the visual information collected by depth camera. On the one hand, the gesture is recognized through normalization resampling and alignment based on the trajectory feature. On the other hand, the gesture is recognized through sparse representation alignment based on the HOG feature. The recognition results are fused effectively. The experimental results indicate that our …

The Santa Clara, 2019-02-14, Santa Clara University

The Santa Clara

No abstract provided.

Hard, Soft And Off-The-Shelf Foot Orthoses And Their Effect On The Angle Of The Medial Longitudinal Arch: A Biplane Fluoroscopy Study, Megan E.R. Balsdon, Colin E. Dombroski, Kristen Bushey, Thomas Jenkyn

Mechanical and Materials Engineering Publications

Background: Foot orthoses have proven to be effective for conservative management of various pathologies. Pathologies of the lower limb can be caused by abnormal biomechanics such as abnormal foot structure and alignment, leading to inadequate support. Objectives: To compare biomechanical effects of different foot orthoses on the medial longitudinal arch (MLA) during dynamic gait using skeletal kinematics. Study Design: Prospective, cross-sectional study design. Methods: The MLA angle was measured for 12 participants among three groups: pes planus, pes cavus and normal arch. Five conditions were compared: three orthotic devices (hard custom foot orthosis (CFO), soft CFO, and off-the-shelf Barefoot Science©), …

Idea Factory Expands After Just One Year | College Of Engineering, Utah State University

College of Engineering News

The College of Engineering expanded its Idea Factory to make more space for the growing number of student users.

Substrate-Dependent Photoconductivity Dynamics In A High-Efficiency Hybrid Perovskite Alloy, Ali Moeed Tirmzi, Jeffrey A. Christians, Ryan P. Dwyer, David T. Moore, John A. Marohn

Faculty Publications

Films of (FA_0.79MA_0.16Cs_0.05)_0.97Pb(I_0.84Br_0.16)_2.97 were grown over TiO₂, SnO₂, indium tin oxide (ITO), and NiO. Film conductivity was interrogated by measuring the in-phase and out-of-phase forces acting between the film and a charged microcantilever. We followed the films’ conductivity versus time, frequency, light intensity, and temperature (233−312 K). Perovskite conductivity was high and light-independent over ITO and NiO. Over TiO₂ and SnO₂, the conductivity was low in the dark,increased with light intensity, and persisted for 10’s of seconds after the light …

College Of Engineering News, Georgia Southern University

College of Engineering & Computing: News & Publications (2010-2023)

• MSCE student Mariah Peart honored as one of 10 new Faces of Civil Engineering