Operations Research, Systems Engineering and Industrial Engineering Commons^™

Framework And Methodology For Logistics Simulation Based On Fidelity Theory, Yukun Liu, Fu Yu, Mengrui Shan

Journal of System Simulation

Abstract: The quality issue of simulation was studied from the perspective of fidelity. The basic concepts and dimension structures of simulation fidelity and simulation utility were defined according to the features of discrete event logistics system (DELS) simulation after a relationship analysis between fidelity and problems in DELS simulation. A fidelity-based four-stage lifecycle framework with prescriptive contents for each stage was constructed to improve the quality of simulation implementation. A simulation fidelity management process model (FMPM) was built to ensure three processes: pre-control of fidelity design, in-process fidelity management, and afterward fidelity evaluation. Operable methods and tools such …

Design And Implementation Of Real Confrontation Oriented Simulation Models For Artillery Firepower, Baoyu Xu, Hongjun Zhang, Guo Hong, Guangming Xu

Journal of System Simulation

Abstract: Aiming at the training requirement of real confrontation, a simulation method based on real equipment for artillery firepower was proposed on the basis of the analysis of artillery firepower attacking behavior characteristics. By comprehensive use of the sensor, exterior ballistic calculation, satellite positioning, geographic information and damage assessment technology, using a embedded simulation method, a simulation model of artillery firepower fused information collection of artillery firing data, ballistic endpoint simulation and damage assessment was built, which could reflect systematically and comprehensively artillery firepower attacking process and the result of the strike in the actual combat environment. The model …

Qos-Aware Scheduling For Data Intensive Workflow, Wan Cong, Cuirong Wang, Wang Cong

Journal of System Simulation

Abstract: The development of technology enables people to access resources from different data centers. Resource management and scheduling of applications, such as workflow, that are deployed on the cloud computing environment have already become a hot spot. A QoS-aware scheduling algorithm for data intensive workflow on multiple data center environment was proposed. Scheduling data intensive workflow on multiple data center environment has two characteristics: A large amount of data is distributed in different geographical locations, the process of data migration will consume a large amount of time and bandwidth; secondly, the data centers have different price and resources. Data migration …

Analysis Of Rubber Conveyor Belt Sag Resistance Experiment Table Dynamics, Mao Jun, Wang Xin, Hongyue Chen

Journal of System Simulation

Abstract: To study the dynamic characteristics of rubber conveyor belt sag resistance bench working process, by hydraulic cylinder pressure, roll eccentricity error and st2000 conveyor belt thickness error as system incentive, a 3-DOF dynamics sag resistance test bench dynamic model was established. The model was solved by using Simulink. The results show that: as provided by the hydraulic cylinder pressure force of 10, 000 N, in the time domain, the vibration of the idler roller and pass roller slants big, which need to improve the connection stiffness. In the frequency domain, the excitation frequency and the natural frequency have larger …

Computational Investigation Into Thermal-Mechanical Coupling Characteristics Of Disc Brake Under Anti-Lock Braking Condition, Lijun Zhang, He Zhen, Dejian Meng

Journal of System Simulation

Abstract: The braking condition has great influence on the thermal-mechanical coupling characteristics of disc brake. A three-degree-of-freedom dynamic model of braking vehicle was built. The braking force was determined by an anti-lock braking system (ABS) which adopted the threshold-logical control strategy of wheel slip rate. With the model, anti-lock braking processes on dry and wet were simulated. In the meantime, for the sake of comparison, non-anti-lock braking processes were simulated on corresponding road. A thermal-mechanical coupling finite element model of a ventilated disc brake was established. Thermal-mechanical coupling characteristics of brake disc and brake lining were calculated under different braking …

Study On Aircraft Scheduling Optimization Based On Improved Genetic Algorithm, Yaohua Li, Wang Lei

Journal of System Simulation

Abstract: Aircraft scheduling was studied, and an optimization model of aircraft assignment based on the objective function of maximize total profit was suggested. It considered its cost and benefits by combining fleet and aircraft. In the view of the feature of this model, the innovation of genetic algorithm chromosome was carried on, and these chromosomes formatted chromosome groups. The groups interior could cross over and mutate, and the probability of crossover and mutation could dynamically adjust in accordance with adaptive values to accelerate the convergence speed, the model was resolved fast in this way. In the process of simulation with …

Control Allocation Method For Split-Drag-Rudders With Asymmetrical Deflection, Xiaobo Qu, Weiguo Zhang, Jingping Shi

Journal of System Simulation

Abstract: The split drag rudders (SDRs) were usually used for the yaw control of tailless flying wing aircraft with the symmetric deflection mode. This approach was simple and effective, but the upper and lower deflectors of the SDRs were constrained to deflect symmetrically, limiting the distribution and control mode of the deflectors, reducing the maximum available moment in pitch axis and roll axis, affecting the handling performance of the aircraft flying at low speed. A certain flying wing UAV was used as the study model. The CFD method was adopt to investigate the aerodynamic characteristic of SDRs operating in either …

Mixed H2/H∞ Optimal Pid Control For Superheated Steam Temperature System, Weiping Liang, Jiarong Wang

Journal of System Simulation

Abstract: Aiming at the non-linear, large inertial, uncertain parameters and multi-disturbances of the main steam temperature object in power plants, a mixed H₂/H_∞ optimal PID control scheme was designed. The multiplicative perturbed boundary of the H_∞ and the effective range of the PID controller parameters were given under the system being closed-loop stability. An improved gravitational search algorithm was proposed in order to obtain optimum performance indicators. The effectiveness of the algorithm was supported through testing on typical test functions, then the algorithm was applied to optimize the parameters of the main steam temperature system Mixed …

Modeling Method Based On Reachable Set For Safety Path In Autonomous Vehicle Obstacle Avoidance, Cao Kai, Xiaoxiao Huang, Yu Yun, Liu Chun

Journal of System Simulation

Abstract: In view of problem in all possible uncertain behavior of vehicle unable existed by the traditional path planning algorithm, a modeling method was proposed which deemed a moving vehicle as a hybrid system switching dynamically between continuous and discrete mode, modeled an optimal trajectory for vehicle obstacle avoidance by using a single security target location, and built a safe state reachable set based on the trajectory beam of multiple security target locations. On this basis, the condition of the inevitable collision of vehicle was analyzed, and the optimal control problem with loose constraints for the vehicle obstacle avoidance was …

Orthogonal Experimental Optimization Design For Improving Aerodynamic Characteristics Of Hovering Air Vehicle, Yanan Yu

Journal of System Simulation

Abstract: Vertical hovering MAV model with flexible aerodynamic shape was proposed. The passive adaptive deformation that produced on the aerodynamic shape was designed to absorb disturbance from outside airflow pressure, and furthermore to improve aircraft's disturbance resistance ability. Multiple factors' effects for aircraft's aerodynamic characteristics were analyzed, such as structural geometrical parameters, candidate material properties, and environmental parameters. The orthogonal experimental analysis of aircraft aerodynamic forces was accomplished, which include the forces produced in the horizontal and vertical direction. The significant factors effecting on the flight performance were discussed and the best response value in the selected parameter range was …

Spring Unit Equivalent Model Of Steam Turbo-Generator Radial Fixture, Shouqun Sun, Huifang Wei, Haihui Xu

Journal of System Simulation

Abstract: The fixed structure of turbo-generator stator end was studied. Bottom-up modelling method was applied to establish the finite element model. The method calculating the combined stiffness of the connection structure and effective contact area was proposed, which used conical symmetric mid plane. Combined with spring-damper unit, insulated screw was analysed by finite element simulation. The stator winding end as a whole system was for modal analysis. Corresponding natural frequency and vibration model were acquired. Hammering test method and modal testing system were applied to calculate the steam turbine end natural frequency. Compared with the experimental result, the text given …

Dynamic Stochastic Relay Selection Algorithm In Peer-To-Peer Networks, Chengwei Zhang, Wenqing Cheng, Hei Xiaojun

Journal of System Simulation

Abstract: A stochastic routing algorithm for selecting appropriate relay nodes in peer-to-peer networks was proposed. This algorithm was constructed using a stochastic programming framework by leveraging the actual delay of local links and the statistical delay distributions of non-local overlay links. In order to approximate the statistical delay distribution of non-local overlay links, the historical delay values of each link were utilized to approximate the link delay distribution. This algorithm was fully distributed and the stochastic link measurement data could be updated between neighboring nodes at a longer time granularity to reduce routing overhead. This algorithm and …

Bifurcation Multi-Path Grooming Algorithm In Multi-Granularity Transport Network, Guangwei Lei, Xingwei Wang, Huang Min, Zhao Yue

Journal of System Simulation

Abstract: Recent years, with the rapid development and wide use of multi-granularity transport network, the pressure of backbone transmission network has been alleviated to some extent. However, the growing user demands to the Internet make network power consumption and bandwidth still face severe challenge. To deal with it, a bifurcation multi-path grooming algorithm was proposed and its associated bandwidth allocation strategy was devised to reduce power consumption and blocking rate. The proposed algorithm has been implemented by simulation and the evaluation results show that its performance is better than that of the benchmark.

Research On Modeling Of Pump Model Based On Rbf Neural Network, Qinghui Wu, Qinghuan Shen, Xinjun Wang

Journal of System Simulation

Abstract: On the basis of research on pump characteristics and pump model, a modeling method based on RBF neural network with K-means clustering algorithm was proposed. With k-means clustering algorithm the center vector and base width parameters, in which lie in the hidden layer, were optimized by input data sample. The weights between the hidden layer and the output layer were optimized by input-output data sample with least squares method. The neural network models of the pump characteristic and pump comprehensive model were separately trained and checked using the detected data. Its results suggest that reasonably choosing the number of …

Recent Advances In Finite Element Simulation Of Machining Processes, Caixu Yu, Chunbin Cai, Huang Cui, Erliang Liu

Journal of System Simulation

Abstract: Recently, the finite element simulation technology has been widely applied in machining simulation and has played an irreplaceable role in the investigations of machining mechanism of metal and composite materials, optimization of cutting parameters,etc. The importance of finite element simulation, commonly used software and material constitutive model were introduced. The latest research progress of the finite element simulation of cutting at home and abroad was summarized, including the simulation of chip morphology, the simulation of cutting force and cutting temperature, tool wear simulation, the machined surface integrity, simulation of the effect of multi-steps cutting on cutting process and finite …

Models For Data Analysis In Accelerated Reliability Growth, Cesar Alexander Ruiz Torres

Graduate Theses and Dissertations

This work develops new methodologies for analyzing accelerated testing data in the context of a reliability growth program for a complex multi-component system. Each component has multiple failure modes and the growth program consists of multiple test-fix stages with corrective actions applied at the end of each stage. The first group of methods considers time-to-failure data and test covariates for predicting the final reliability of the system. The time-to-failure of each failure mode is assumed to follow a Weibull distribution with rate parameter proportional to an acceleration factor. Acceleration factors are specific to each failure mode and test covariates. We …

Deep Learning Based Poisson Solver In Particle Simulation Of Pn Junction With Transient Esd Excitation, Ling Zhang, Wenchang Huang, Zeyi Sun, Nicholas Erickson, Ryan From, Jun Fan

Engineering Management and Systems Engineering Faculty Research & Creative Works

In particle simulations of semiconductor devices for electro-static discharge (ESD) study at the microscopic level, solving Poisson's equation is an inevitable but time-consuming step. In this work, a deep learning technique is utilized to resolve Poisson's equation for a PN junction under an ESD event, namely using a trained deep neural network (DNN) to predict the potential distribution according to the charge distribution and the boundary condition under a transient ESD excitation. To improve the generalization performance of the DNN, multiple typical ESD curves with different parameters are used as the excitation boundary to generate large amounts of training data …

Combining Machine Learning And Empirical Engineering Methods Towards Improving Oil Production Forecasting, Andrew J. Allen

Master's Theses

Current methods of production forecasting such as decline curve analysis (DCA) or numerical simulation require years of historical production data, and their accuracy is limited by the choice of model parameters. Unconventional resources have proven challenging to apply traditional methods of production forecasting because they lack long production histories and have extremely variable model parameters. This research proposes a data-driven alternative to reservoir simulation and production forecasting techniques. We create a proxy-well model for predicting cumulative oil production by selecting statistically significant well completion parameters and reservoir information as independent predictor variables in regression-based models. Then, principal component analysis (PCA) …

Study On New Sampling Plans And Optimal Integration With Proactive Maintenance In Production Systems, Sinan Obaidat

Graduate Theses and Dissertations

Sampling plans are statistical process control (SPC) tools used mainly in production processes. They are employed to control processes by monitoring the quality of produced products and alerting for necessary adjustments or maintenance. Sampling is used when an undesirable change (shift) in a process is unobservable and needs time to discover. Basically, the shift occurs when an assignable cause affects the process. Wrong setups, defective raw materials, degraded components are examples of assignable causes. The assignable cause causes a variable (or attribute) quality characteristic to shift from the desired state to an undesired state.

The main concern of sampling is …

Gender Differences And Cockpit Design, Susan Archer, Heidi Brewer, Stacie Fain, Stephanie Smith

Student Works

The design project reported in this paper examined female pilots’ experiences with how well or poorly cockpit design allowed them to safely accomplish their flying missions. The general aviation aircraft cockpit is not designed for female pilots, often causing them to find ways to adapt to the cockpit in order to operate the aircraft safely. Two primary focal areas for adaptations address issues with accessibility of controls and “viewability” inside and outside the cockpit. The design team used a Situation Awareness-Oriented Interface Design (SAOD) approach in preparing cockpit design recommendations for general aviation aircraft that would accommodate female pilots.