Engineering Commons^™

Passive Radar Simulation And Evaluation System Based On Raw Signals, Xiaofeng Ai, Yonghu Zeng, Liandong Wang, Guangyong Zheng, Xiaoyang Wang, Manxi Wang

Journal of System Simulation

Abstract: Detection ability of the passive radar is very closely related with many factors in the real aplication. A method was proposed based on the raw data and the dynamic characteristics of a specific target. In this method, the reference and the surveillance channels' signals were obtained through the actual passive radar receiving system. The direct-path signal was reconstructed by using the reference signal. The target echo was obtained by modulating the direct-path signal with the echo power, delay and Doppler parameters, which was calculated with the move and scattering characteristics of target. Adding the target echo to surveillance channel, …

Segmentation And Recognition Of Hand-Drawn Situation Maps, Deng Wei, Lingda Wu, Yougen Zhang, Yang Chao

Journal of System Simulation

Abstract: Most of current research on online sketched military symbol recognition concerns the isolated samples. In pen-based situation marking systems, users prefer segmenting and recognizing the full sketched situation maps. However, it is a more difficult problem. The characteristics of hand-drawn situation maps and difficulties to segment them were analyzed, and a dynamic programming-based approach was proposed. A hand-drawn situation map was segmented coarsely by minimum spanning tree-based stroke clustering. The candidate segmentation path was evaluated by synthesizing geometric analysis and isolated symbol classifier together, using confidence transformation and fusion. The dynamic programming algorithm was used to search the …

Robust Steerable Frequency Invariant Beamformer Design Based On Srv-Cls, Suting Chen, Zhang Wei

Journal of System Simulation

Abstract: The frequency invariant beamformer (FIB) has important applications in wideband array signal processing. Conventional FIB design approaches are usually proposed without considering the mismatches in microphone array characteristic, which leads to the performance of the FIBs degrading in practical applications. Therefore, a robust steerable frequency invariant beamformer design approach based on spatial response variation constrained least squares (SRV-CLS) was proposed. It combined the SRV-CLS FIB design approach with classical robust beamforming algorithm, and added the microphone characteristics as robust favor in the cost function. The proposed approach could work well in the presence of microphone mismatches, ensured the frequency …

Dynamic Arrival Sequencing & Scheduling Based On Branch & Bound Algorithm, Junfeng Zhang, Wang Fei, Tengteng Ge

Journal of System Simulation

Abstract: Optimization of arrival sequencing and scheduling is not only the prerequisite for properly allocating and fully utilizing the runway resource, but also the fundamental element for improving terminal operation efficiency. Dynamic arrival sequencing was obtained by time-triggered sliding time window method. On the basis of accurate 4D trajectory prediction, branch and bound algorithm was adopted to generate an optimal sequence, combined with the actual operation constraints. Taking Shanghai Pudong Airport as an example for simulation, the optimization results were compared with the actual landing time and simulation results based on first come first serve strategy. The results indicate that …

Simulation Study On External Explode Of Large Equivalent Charge On Large Buildings, Weiping Zhao, Xiankun Ge, Chuanwu Liu, Fengchun Zhu

Journal of System Simulation

Abstract: The particle algorithm in AUTODYN, Smoothed Particle Hydrodynamics (SPH), was used to simulate dynamic damage of the external explosion on large buildings, which provided a visual effect. The dynamic damage details of reinforced concrete and brick masonry structure at different time were proposed by the simulation of single component. Additionally, the overpressure of shock wave, caving velocity and kinetic energy were obtained. It shows that the caving can speed up to a maximum value of 152 m/s with the kinetic energy of 18 000 J, that means a great damage to personnel and equipment in the building. Under …

Study Of Cognitive Model For Survivable System Based On High-Order Multi-Type Π Calculus, Guosheng Zhao, Zhang Nan, Wang Jian

Journal of System Simulation

Abstract: A cognitive model for survivable system with a multilayer cognitive ability was proposed, and based on high-order multi-type π calculus, combining formal modeling of cognitive model with quantitative analysis of cognitive performance, thus can obtain the quantitative evaluation of system cognitive performance after formal modeling of system operation state, system service and internal structure. A cognitive model for survivable system with a multilayer cognitive ability was proposed. Based on high-order multi-type π calculus, formal modeling of cognitive model for survivable system in two aspects was taken. By using the tool MWB, the tests were achieved about system availability, instantaneous …

Research On Direct Torque Control Of Induction Motor Based On Svpwm, Yougui Guo, Dongqing Pan, Deng Cheng, Li Hui, Wenlang Deng

Journal of System Simulation

Abstract: The traditional direct torque control of induction motor directly controls the flux and torque through hysteresis comparator, which leads to problems such as limited voltage control vectors, large flux and torque ripple. To solve the problems, adopting SVPWM-DTC, a direct toque control (DTC) method based on space vector pulse width modulation (SVPWM) was verified with a simulation. The results show that this method can improve the performances of DTC system efficiently and maintain the switch frequency constant at the same time. A practical application used in variable speed constant frequency double-fed wind power system was proposed, in which the …

Novel Material For Advanced Tissue Regeneration, Karrer Mahdi Kadum Alghazali

Theses and Dissertations

Nerve tissue damage or failure can occur for various reasons, including infection, disease, aging, and trauma. The tissue microenvironment (extracellular matrix-ECM) plays a key role in regulating the self-renewal and recovery of damaged tissue. ECM-cell interactions govern cell migration and physiology, with biochemical and biophysical boundaries being the main factors that control ECM-cell interaction. Optimizing these boundaries for the recovering tissue will create a healthy microenvironment to support and enhance the recovery rate (1, 2). We have developed a novel, multidimensional nanocomposite system that incorporates gold nanorods (AuNRs) (aspect ratio of around 3) as an artificial ECM for cell adhesion, …

Study Of Light Extraction Efficiency For Thin-Film-Flip-Chip Light-Emitting Diodes With Periodic Spheroids, Xiaojie Yu, Li Kang, Fanmin Kong, Qingyang Yue

Journal of System Simulation

Abstract: The enhancement of light extraction efficiency for thin-film-flip-chip light-emitting diodes (LED) based gallium nitride (GaN) with triangular lattice periodic ellipsoid was studied. Three dimensional finite difference time domain methods (3D-FDTD) were applied to analyze the structural parameters (the period and ellipsoid height) effects on thin-film-flip-chip LED light extraction efficiency. FDTD numerical results prove that ellipsoids structure can improve LED light extraction efficiency and impair guide mode. Method rigorous coupled wave (RCWA) is adopted to analyze diffraction characteristics. This research results show that optimization of the periodic ellipsoid can improve thin-film-flip-chip LED light extraction efficiency increased by 2.8 times.

Prediction Of Energy Efficiency Of Nc Machine Tools Based On Recursive Method With Discounted Measurements, Cai Lei, Wang Yan, Zhicheng Ji

Journal of System Simulation

Abstract: Aiming at the problem that the energy efficiency of numerical control machine tool is difficult to obtain directly, a new method combined with the recursive method with discounted measurements was presented to predict the energy efficiency of machine tool. The estimation model of the cutting power was given in view of the power balance equation of the machine tool main drive system and the additional load loss function, further taking into account the additional load loss coefficients in model could not be directly measured, the recursive method with discounted measurements was adopted to identify the additional load loss coefficients …

Invasive Weed Optimization Algorithm Combined With Chaotic Mutation And Analysis Of Its Property, Huang Xia, Chunming Ye, Cao Lei

Journal of System Simulation

Abstract: Inspired by the reproductive aggressive behavior of weeds in nature, invasive weed optimization algorithm (IWO) was developed as a novel bionic swarm intelligence optimization algorithm. An improved IWO algorithm was proposed on the basis of analyzing bionic principle and limitations of basic IWO, which applied an initialization strategy based on chaotic opposition-based learning, increased the diversity of the population through the mutation operator, and enhanced its ability to jump out of local optimal value by chaotic search around current elites. Simulation results for benchmark functions show that the proposed algorithm has improved optimization property compared with IWO, as an …

Cooperative Controller Design For Redundant Dual Arm Robot, Meiling Wang, Minzhou Luo

Journal of System Simulation

Abstract: Cooperative operation for a redundant dual arm robot can be divided into three modes, namely, independent mode, full constrained cooperative working mode and partly constrained cooperative working mode. The dynamic equations of both dual arms and the interactions between dual arms and the operating objects were established and derived based on the three modes, and a unified formulation was obtained. With focus on motion and force of the desired task being operated, a unified controller was designed which could be carried out based on two dynamic model based controllers, namely feedforward controller and computer torque controller. Simulations of dual …

Modeling And Motion Analysis Of Multi-Bodies Dynamic Of Unmaned Parafoil Vehicle, Zhang Hao, Zili Chen, Jingang Qiu

Journal of System Simulation

Abstract: Unmanned Parafoil Vehicle (UPV) has gradually become a hotspot in the flexible wing vehicle research filed for its superior fight performance and advantages in application. An eight degrees of freedom (DOF) nonlinear dynamic model of UPV in mechanism law was proposed, aiming at the structure characteristics of the two flexible connections, and considering the added mass of canopy and the relative motion of two bodies. The response of model to different levels of thrust changes was simulated and analyzed, pulling a single steering line and pulling the left and right steering lines of canopy symmetrically on the steady state …

Wood Structure Nondestructive Detection Based On Singular Spectrum Analysis And Svm, Guoxiong Zhou, Aibin Chen, Xianyan Zhou

Journal of System Simulation

Abstract: In view of unknown defect of wood component defect, a method of wood structure nondestructive recognition based on Singular spectrum analysis and SVM was proposed. The wood specimen was tested to obtain the test signal by ultrasonic testing instrument. In order to eliminate the testing effect of the tester gain control and defect size, angle variation on the test defect echo amplitude, the abnormal fluctuation was to filter and characteristic of the original signal was extracted by singular spectrum analysis, and SVM could train the parameters and distinguish the wood defects. Simulation results show that the proposed method …

Analysis And Simulation Of A Class Of Time-Varying Wireless Networked Control Systems, Weihua Deng, Minrui Fei

Journal of System Simulation

Abstract: The problem of stabilization was investigated for a class of discrete time-varying systems over a physical IEEE 802.11b wireless channel. The wireless network-induced delays were characterized by an inverse Gaussian distribution model (IGDM) and the time-varying nature was depicted by uncertain parameter model. The model-based state feedback controller was designed to compensate the influence of delays and time-varying nature. And the stochastic stabilisability of discrete time-varying networked control system was analyzed and the solution of controller was given in the form of linear matrix inequalities (LMIs). The effectiveness of the proposed methods was illustrated by numerical simulation examples.

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

• Computer Lab Availability for Commuting Students

Improving Energy Savings And Peak Demand Reduction Estimates Using Ami Data For Utility Commercial Rebate Programs, Florida Solar Energy Center, Karen Fenaughty

FSEC Energy Research Center®

Solar reflective, or cool roofs, are a demonstrated method of reducing air conditioning energy, particularly in cooling-dominated climates. Similarly, efficient lighting or mechanical equipment replacement programs have a reputation for achieving large savings in c01mnercial buildings. Savings estimates for such measures have historically used monthly utility bills, which only provide a macroscopic view of utility program savings. Advanced Metering Infrastructure (AMI) is commonly used in the U.S. by utilities for residential and commercial customers and provides not only a valuable record of changing premise energy use and demand profiles but in much greater detail than utility bills, if desired.

Partnering …

Characterization Of Mechanical Ventilation Systems In New Us Homes: What Types Of Systems Are Out There And Are They Functioning As Intended?, Florida Solar Energy Center, Eric Martin

FSEC Energy Research Center®

As the airtightness of homes improves to meet energy efficiency goals, it becomes more important for mechanical ventilation systems to help maintain a comfortable and healthy indoor air environment. ASHRAE Standard 62.2 provides national guidance for mechanical ventilation system design and installation, however adoption of those guidelines into local building codes has occurred at different rates. Once provisions for mechanical ventilation are adopted in a local code, are mechanical ventilation systems properly designed, installed, commissioned and operated according to code or above-code program requirements? This paper presents results from field studies that include characterization of whole house mechanical ventilation (WHMV) …

Prototype Instrument Development For Measuring Directionality Of Aerosol Light Scattering, Esther K. Monroe

McKelvey School of Engineering Graduate Student Theses & Dissertations

Investigation of aerosol interactions with electromagnetic waves provides insights into the scattering particles. Aerosol phase function, an angular distribution of scattered light, is a value required to calculate parameters used in direct radiative forcing (DRF) models in the atmosphere. Currently no direct measurement of phase function is available hence it is estimated from ground observations such as backscatter fraction b and subsequently relating the parameters via Henyey-Greenstein (HG) approximation. This method has shown to introduce errors in radiation transfer models. HG phase function, in particular, does not account for particle microphysical properties such as shape and refractive index. Given the …

Signals In The Soil: An Introduction To Wireless Underground Communications, Abdul Salam, Usman Raza

Computer Information Technology Faculty Publications

In this chapter, wireless underground (UG) communications are introduced. A detailed overview of WUC is given. A comprehensive review of research challenges in WUC is presented. The evolution of underground wireless is also discussed. Moreover, different component of UG communications is wireless. The WUC system architecture is explained with a detailed discussion of the anatomy of an underground mote. The examples of UG wireless communication systems are explored. Furthermore, the differences of UG wireless and over-the-air wireless are debated. Different types of wireless underground channel (e.g., In-Soil, Soil-to-Air, and Air-to-Soil) are reported as well.

Cellular Automata Model Of Non-Motor Vehicle Flow Considering Reverse Vehicles, Xianyan Kuang, Weihua Cao, Wu Yun

Journal of System Simulation

Abstract: The phenomenon of non-motor vehicle reverse driving in one-way non-motor vehicle road occurs in most China's cities. A cellular automata model of non-motor vehicle flow mixed with reverse driving vehicles was established, which considered the different lane-changing rules of the reverse and forward vehicle. The results of the computer numerical simulation for the model show that, in low density stage, the ratio of reverse vehicles has little effect on flow and speed, and the capacity and the avenge speed decrease as the ratio of reverse vehicles increases. Lane-changing ratio has a great influence on the mixed non-motor vehicles …

General Modeling Method Of Aircraft Constant-Altitude Flight, Xiaowen Duan, Xiaoguang Gao, Li Bo

Journal of System Simulation

Abstract: An algorithm for the aircraft constant-altitude long-distance flight consider earth curvature studied. The required overload was calculated using the error between the real position and the ideal trajectory for two basic long-distance flight styles, i.e. great circle flight and circular flight, the simulation model of the two basic constant-altitude flight styles was established. On this basis, taking the modeling of constant-altitude box maneuvering and 8-shape constant-altitude flight as an example, the modeling process of constant-altitude combined model was studied. The simulation result shows the constant-altitude flight model can be widely used, easily implemented and easily expanded. Meanwhile, the model …

Signaling Game Analysis And Simulation On Network Decoy Defense Strategies, Leyi Shi, Junnan Zhao, Li Qin, Wen Xiao, Liu Xin

Journal of System Simulation

Abstract: The network decoy confrontation is regarded as a kind of observable behavior of a multi-stage signaling game. Four types of gaming models for decoy confrontation process were constructed step by step using signaling game theory, i.e. the normal service, the mixed system of normal service and honeypot, the mixed system with two kinds of signaling, and the mixed system with two kinds of signaling and three actions. In these signaling game models, the server sent a normal signaling or honeypot signaling as the sender, while the attacker chose to access, give up or access in condition as the …

Research And Simulation On Trajectory Control Of Telescopic Boom Aerial Work Platform For Hull Spray Painting, Wang Xin, Lingchong Gao, Zhaoqiu Huang, Yuchen Xiao

Journal of System Simulation

Abstract: Telescopic boom aerial work platform, which has been widely applied in ship building field, is taken as research object. An intelligent method of spray painting, continuous spray painting along hull's contour was proposed. Correspondence between position vector of boom's top and drive-space vector was established. A path planning strategy of continuous spray painting was designed, and the variation of driving-space vector was acquired when the path was known. The trajectory control system of intelligent spray painting was modeled in Simulink environment based on the transfer function of electro-hydraulic proportional position control system. The correction link made of …

Modeling And Simulation Of Multi-Nozzle Ejector Based On Flowmaster, Lan Jiang, Zhu Lei, Jingquan Zhao

Journal of System Simulation

Abstract: A mathematical model of multi-nozzle ejector was established according to the mass conservation, energy conservation and momentum conservation, and a modification was achieved with the introduction of momentum correction coefficient and discharge coefficient. On this basis, linear coefficients used in the fluid network method were determined, then a system-level simulation model of multi-nozzle ejector was first developed with C# language on the fluid system simulation software of Flowmaster. The simulation and experimental results of the multi-nozzle ejector in an aircraft environmental control system shows that the entrainment ratio decreases with the increasing pressure ratio of primary and secondary flow. …

Evaluation Method Of Training Simulation Result Based On Grey Clustering And Analytic Hierarchy Process, Zhaobin Wu, Chen Li, Chunxia Zhao

Journal of System Simulation

Abstract: An evaluation method based on grey relational analytic hierarchy process was proposed in order to improve rationality of evaluation training result of portable anti-air missile training simulation system. The evaluating indicators including definitions and calculation equations were proposed from three aspects including accuracy, rapidity and stationarity. The weights of the evaluating indicators were calculated by analytic hierarchy process of multiple experts, and the scores of the evaluating indicators were given by 0-1 process and grey clustering evaluation, and using the weights and scores of the evaluating indicators the training score could be obtained. An example of evaluation training result …

Simulation And Optimization For Bulk Terminal Yard Scheduling, Dongbo Hu, Li Pan, Binbin Zhang, Guozhi Liang

Journal of System Simulation

Abstract: Yard is the central part of the operation process of the whole terminal. In fact, the operation of lots of bulk terminal is unscientific, which severely restricts the turnover efficiency and the throughput of the terminal. Taking the coal terminal as an example and based on its operation process, the dispatching simulation model involving all parts of the operation was established and the rules of use of the yard grids was brought forward. By optimizing the operation strategy and related parameters, it is significant to improve the input quantity of bulk terminal and the turnover efficiency.

Simulation On Aircraft Infrared Exposed Range And Detection Probability, Yunfei Zhang, Mengyue Hu, Dexiong Lai, Gengjun Ma

Journal of System Simulation

Abstract: According to the infrared-detector operating range equation, the method used to simulate the infrared detection probability and exposure of an aircraft was established, with the use of atmospheric transmission rate calculation method, the critical radiation strength calculation method and the detection probability calculation method. The physical meaning of the exposed range was analyzed, and an infrared detection simulation system was established. The system could be used to assess the infrared stealth performance of an aircraft, which includes the curve of detection probability and the curve of exposed range, giving the flight route and the infrared radiation intensity distribution of …

Novel Modeling Of Memristive Cellular Neural Network And Its Circuit Simulation, Xiaohong Zhang, Linyu Liao, Lianghua Yu

Journal of System Simulation

Abstract: The memristor as the fourth fundamental circuit component included along with the resistor, capacitor and inductor could simulate the storage memory function of brain neural network. A traditional three-dimensional CNN was designed, and the output function was implemented with the nonlinear characteristics of a flux-controlled memristor. The conventional electronic devices in Multisim were utilized to simulate flux-controlled memristor which simplified the output function part of the circuits. To compare with the CNN system which has chaotic behaviors, the circuits of novel memristive cellular neural network not only can show a chaos attractors phenomenon, but also the inner magnetic energy …

Using Raster Lattices To Build Terrain Attribute Of Wargame Map, Jinming Zhang

Journal of System Simulation

Abstract: Wargame map is a sketchy description of geographical environment under certain conditions. It is used to assist commanders or operational models to locate spatial positions and to determine spatial attributes. The former process is called geometric modeling and the latter attribute modeling, and the combination of which is known as Wargame Map Modeling. A Raster Lattice Algorithm for attribute modeling was proposed, which could effectively reduce modeling complexity and improve modeling efficiency. The basic process of attribute modeling and discussing its difficulty was described, i.e., the calculation of the covered areal ratio between hexagon and the geographical environment element. …