Engineering Commons^™

Simulation On Aviation Maintenance Support System Based On Goal-Driven, Jiping Cong, Lijie Cui, Ding Gang, Ren Bo

Journal of System Simulation

Abstract: Aiming at the large investment and long time for optimization in aviation maintenance support model practice, for the first time, based on Netlogo platform, the multi-agent aviation maintenance support simulation system is constructed, which provides a reference to adapt the current support tasks and improve the evaluation efficiency. Selecting the annual mission flight time, echelon status, aircraft intact rate, and mission completion rate as the goal drivers, the simulation on different aviation maintenance support process is carried out, which displays the changes in flight arrangements, aircraft status, personnel, support equipment, etc. The simulation experiment shows that the multi-agent …

Modeling And Simulation On Optimum Maneuver Control Surface Configuration Of Aircraft In Low Altitude Penetration Mode, Huzi Wu, Wang Jin, Wantao Qi, Kaibao Jin

Journal of System Simulation

Abstract: Optimum maneuver control surface can ensure the safety flight cability of aircraft in low altitude penetration mode, and it is of great siginifcance to establish the valid and effective numerical simulation model. The numerical differential equations with muti-constraints is adopted for the first time, to construct the simulaton model for the aircraft with small wing load and mutifunctional and combined CS in low altitude manuever, the schemes of different maneuver CS considering the obstacle, the limit of angle of bank, the graident of climb are built. The simulation results show that the model is effective for solving the …

Research On Simulation Object Interfaces Oriented To Plug-In-Play Pattern, Zhongwei Lin, Xiuhe Li, Yiping Yao, Shen Yang, Shaoqi Dai, Qianqian Shi

Journal of System Simulation

Abstract: Models and simulation engines provide services mainly in the format of executable files in cloud environment, thus plug-in-play pattern becomes the first choice of simulation, which needs necessitating interfaces to connect the model processing logics and the simulation engine control logics. A set of simulation object interfaces that covers the simulation full life cycle of initialization, event scheduling, processing and cancel, publish and processing of subscription, roll-back and termination is proposed, and then defined in C++ language. Two examples show the process of the interfaces and the effectiveness of constructing the simulation objects. With the instantiation and disposal …

Research And Implementation Of A High Performance Distributed Object-Oriented Simulation Engine, Xiaodong Huang, Kongshu Xie

Journal of System Simulation

Abstract: Simulation engine is the core of simulation platform and the operating system of simulation field. On the basis of the reflection-based object-oriented simulation modeling framework and programing specification, aiming at the developing integration and operation requirements for the large-scale multi-granularity computation intensive simulation system, a High-performance Distributed Object-oriented Simulation Engine (HDOSE) is developed. Combined with the brief review of HDOSE development, on the basis of expounding the HDOSE function services and architecture, the key technology, large-scale multi-granularity parallel computation, programming model and interface, parameterized componentized modeling and so on are mainly introduced. The HDOSE typical application cases …

Whole Ship Simulation Training Platform Based On Virtual Reality, Jiawen Sun, Hongxiang Ren, Fangbing Xiao, Xiaobin Jiang

Journal of System Simulation

Abstract: Under the current navigation education mode, it is common that trainees lack the overall navigation knowledge and the operation practice on onboard equipment and instruments. It is necessary to develop a whole ship simulation training platform that is not limited by time and sites. The six-degree freedom mathematical model of ship motion is established by using the separation modeling theory of ship maneuverability. The flexible object simulation technology, the modeling and rendering of ocean wave technology, and the reverse dynamics technology are adopted to realize the ship scene roaming and equipment interaction. The simulation results show that …

Evolutionary Simulation Of Medical Products Export Safety Supervision Considering Regulation Of Importing Country, Xiaoli Li, Cejun Cao, Fanshun Zhang

Journal of System Simulation

Abstract: In order to investigate the impacts of the regulation of importing country on export safety supervision regarding medical products in the COVID-19 epidemic situation, an evolutionary game model considering the relation between export enterprise and supervision of government is constructed. Based on MATLAB simulation, the influences of different factors including regulation level of importing country, punishment mechanism on export safety supervision of medical products are analyzed. Results show that the illegal behaviors of the export enterprises of medical products can be restrained when the regulation level of importing country reaches a certain threshold. But that would fuel the passively …

Classification Of Flight Delay Based On Nonlinear Weighted Xgboost, Tang Hong, Wang Dong, Song Bo, Wenkui Chu, Linyuan He

Journal of System Simulation

Abstract: Aiming at the classification of flight delay under imbalance data, a novel method based on nonlinear weighted XGBoost (extreme gradient boosting) is proposed. The imbalance of flight delay data and the influence for classification performance caused by the data imbalance are analyzed. A heuristic nonlinear weighting method based on sample proportion is proposed, and the negative log likelihood loss function is optimized. The real flight delay dataset is used to validate the performance of the classification algorithm. The experiment results show that the proposed nonlinear weighted XGBoost algorithm can improve the classification accuracy of flight delay, while ensuing a …

Research On Benefits Of Mixed Traffic Flow Of Intelligent Connected Vehicles, Mingwei Hu, Zhiming Zhang, Xiangsheng Chen

Journal of System Simulation

Abstract: In order to study the benefits of the mixed traffic flow Intelligent Connected Vehicles (ICV) and non-connected vehicles, aiming at the intelligent and connected characteristics of ICV. Through the microscopic traffic simulation software Vissim redevelopment, ICV having the function of intelligent connected vehicles traffic flow modeling is realized. The mixed traffic flow composed of intelligent connected vehicles and non-connected vehicles under different market penetration rates is simulated. By comparing the traffic benefits at different time periods and different penetration rates, it is found that with the increase of the market penetration rate of intelligent connected vehicles, the average speed …

Visual Analysis Method Of Tobacco Quality Data Based On Dimension Reduction, Tian Dong, Guihua Shan, Xuebin Chi, Yanling Zhang, Weihua Feng, Jianwei Wang, Aiguo Wang, Wang Rui

Journal of System Simulation

Abstract: In order to meet the requirements of tobacco leaf matching across regions in tobacco material selection, a visual analysis method of tobacco leaf quality data that incorporating dimension reduction and correlation analysis methods is developed. Through the dimension reduction algorithm, the comparison algorithm and the visual interaction method based on the classification of aroma area for tobacco leaf quality data, a visual analysis method for exploring space division and correlation analysis of tobacco leaf quality data is provided. National tobacco leaf quality data analysis cases and expert demonstrations show that the method can carry out the tobacco leaf quality …

Hidden In Plain Sight: Why Sustainment Is So Critical To The Circular Supply Chains For Technical Products, Dave Peterson

Operations Management Presentations

• Technical products are typically complex, long-lived and high-cost equipment—such as: aircraft, vehicles, ships, capital equipment/machinery and utilities infrastructure. While many technical products are manufactured via traditional linear supply chains, their useful lives often rely upon sustainment systems incorporating significant aspects of circular supply chains. This webinar takes a closer look at technical products and the critical role of systems sustainment to achieve and fulfill circular supply chains. The key takeaways from this webinar are:
  • The Earth is running out of resources which will have a direct impact upon maintaining/improving our quality of life.
  • The circular economy philosophy has definite relevance …

Quantifying Time-Frequency Co-Movement Impact Of Covid-19 On U.S. And China Stock Market Toward Investor Sentiment Index, Rui Nian, Yijin Xu, Qiang Yuan, Chen Feng, Amaury Lendasse

Engineering Management and Systems Engineering Faculty Research & Creative Works

The Worldwide Spread of Covid-19 Dramatically Influences the World Economic Landscape. in This Paper, We Have Quantitatively Investigated the Time-Frequency Co-Movement Impact of Covid-19 on U.S. and China Stock Market Since Early 2020 in Terms of Daily Observation from National Association of Securities Dealers Automated Quotations Index (Ndx), Dow Jones Industrial Average (Djia), Standard & Poor's 500 Index (Spx), Shanghai Securities Composite Index (Ssec), Shenzhen Securities Component Index (Szi), in Favor of Spatiotemporal Interactions over Investor Sentiment Index, and Propose to Explore the Divisibility and the Predictability to the Volatility of Stock Market during the Development of Covid-19. We Integrate …

Applying Model-Based Systems Engineering And Fidelity Quantification To Support Fair Fight In A Distributed Simulation System, Nathaniel Erbe, David Lemmer

Theses and Dissertations

Current 5th and 6th generation fighter aircraft capabilities, and the DoD's push towards digital engineering have created an environment in which simulated testing using live, virtual, and constructive assets has increasing utility. These simulations need to be credible in the eyes of the stakeholders, which for distributed simulation systems includes establishing fair fight between simulation services. Fair fight is when multiple simulations interoperate without generating one-sided systematic advantages. Issues that impede fair fight can be categorized into interoperability issues at the simulations implementation level and incompatible representations of reality between underlying models. This research used model-based systems engineering to generate …

New Methods In Wavelet Analysis For Applications Of The Wavelet Transform, Jeffrey D. Williams

Theses and Dissertations

A commonality in the many applications and domains where signal processing (SP)is applied is the detection of events. Detection in SP requires the identification of the occurrence of an event, within a signal, and distinguishing the occurrence from no event. In a classical application of SP, seismologists seek to detect abnormalities in an electromagnetic (EM) signal to detect or not detect the occurrence of an earthquake, represented as an anomalous EM pulse. Since many signals are noisy, such as those produced by a seismograph, it can be challenging to distinguish a significant EM pulse from incident noise. In SP, smoothing …

Wavelet Methods For Very-Short Term Forecasting Of Functional Time Series, Jared K. Nystrom

Theses and Dissertations

Space launch operations at Kennedy Space Center and Cape Canaveral Space Force Station (KSC/CCSFS) are complicated by unique requirements for near-real time determination of risk from lightning. Lightning forecast weather sensor networks produce data that are noisy, high volume, and high frequency time series for which traditional forecasting methods are often ill-suited. Current approaches result in significant residual uncertainties and consequentially may result in forecasting operational policies that are excessively conservative or inefficient. This work proposes a new methodology of wavelet-enabled semiparametric modeling to develop accurate and timely forecasts robust against chaotic functional data. Wavelets methods are first used to …

Collaborative All-Source Navigation With Integrity, Jonathon S. Gipson

Theses and Dissertations

The novel ARMAS-SOM framework fuses collaborative all-source sensor information in a resilient manner with fault detection, exclusion, and integrity solutions recognizable to a GNSS user. This framework uses a multi-filter residual monitoring approach for fault detection and exclusion and is augmented with an additional "observability" EKF sub-layer for resilience. We monitor the a posteriori state covariances in this sub-layer to provide intrinsic awareness when navigation state observability assumptions required for integrity are in danger. This is used to selectively augment the framework with offboard information to preserve resilience. By maintaining split parallel collaborative and proprioceptive estimation instances and employing a …

Interdependent Infrastructure Recovery Using Multilayered Networks And Optimization, Brigham A. Moore

Theses and Dissertations

Interdependent infrastructure recovery modeling and simulation are complicated due to various interdependent connections and complexities. Current efforts have identified both operational and restoration interdependency subtypes and coupling strategies that have not been integrated into one comprehensive model. This research presents a model which simultaneously integrates nine interdependency subtypes and four coupling strategies in a multi-objective format to provide the most tailorable and comprehensive network-based recovery model available. This research also created a defense-centric interdependent infrastructure database by modifying the existing CLARC database. This research then addressed assumptions regarding recovery work management in order to address the impact of work crew …

Requirements Analysis And Architecture For An Operational Study Of Fatigue In Usaf Mobility Aircrew, Jonathan F. Mecham

Theses and Dissertations

Aircrew fatigue in flight operations is a known hazard that has driven the creation of fatigue-reducing regulation and fatigue risk management systems industry wide. In addition, biomathematical models have been created and tested to forecast the effectiveness of aircrew under conditions of time-zone shifts and long duty days. However, limited operational studies exist to validate these models or to help understand how individual factors can affect them. Operational studies have a variety of limitations that make gathering typical data regarding fatigue or sleep difficult. This research takes systems requirement analysis approach to design a study that measures effects of circadian …

Performance Improvement Through Better Understanding Of Supply Chain Resilience, Amanda L. Femano

Theses and Dissertations

Businesses operate every day in a disruptive environment. Supply and demand uncertainty, natural disasters, global pandemics, and mishaps can all cause chaos to a supply chain’s flow. It is impossible to predict every disruption a supply chain may encounter. The best an organization can do to protect network performance is to build resilience in the supply chain and life-blood of its operations. Ensuring that a supply chain has the proper built-in mechanisms to resist and recover from disruptions is referred to as Supply Chain Resilience (SCR). While it is generally agreed that SCR can be improved through the implementation of …

Enterprise Resource Allocation For Intruder Detection And Interception, Adam B. Haywood

Theses and Dissertations

This research considers the problem of an intruder attempting to traverse a defender's territory in which the defender locates and employs disparate sets of resources to lower the probability of a successful intrusion. The research is conducted in the form of three related research components. The first component examines the problem in which the defender subdivides their territory into spatial stages and knows the plan of intrusion. Alternative resource-probability modeling techniques as well as variable bounding techniques are examined to improve the convergence of global solvers for this nonlinear, nonconvex optimization problem. The second component studies a similar problem but …

Deep Learning For Weather Clustering And Forecasting, Nathaniel R. Beveridge

Theses and Dissertations

Clustering weather data is a valuable endeavor in multiple respects. The results can be used in various ways within a larger weather prediction framework or could simply serve as an analytical tool for characterizing climatic differences of a particular region of interest. This research proposes a methodology for clustering geographic locations based on the similarity in shape of their temperature time series over a long time horizon of approximately 11 months. To this end an emerging and powerful class of clustering techniques that leverages deep learning, called deep representation clustering (DRC), are utilized. Moreover, a time series specific DRC algorithm …

Subnational Map Of Poverty Generated From Remote-Sensing Data In Africa: Using Machine Learning Models And Advanced Regression Methods For Poverty Estimation, Lionel N. Hanke

Master's Theses

According to the 2020 poverty estimates from the World Bank, it is estimated that 9.1% - 9.4% of the global population lived on less than $1.90 per day. It is estimated that the Covid-19 pandemic further aggravated the issue by pushing more than 1% of the global population below the international poverty line of $1.90 per day (WorldBank, 2020). To provide help and formulate effective measures, poverty needs to be located as exact as possible. For this purpose, it was investigated whether regression methods with aggregated remote-sensing data could be used to estimate poverty in Africa. Therefore, five distinct regression …

We Are On The Way: Analysis Of On-Demand Ride-Hailing Systems, Guiyun Feng, Guangwen Kong, Zizhuo Wang

Research Collection Lee Kong Chian School Of Business

Problem definition: Recently, there has been a rapid rise of on-demand ride-hailing platforms, such as Uber and Didi, which allow passengers with smartphones to submit trip requests and match them to drivers based on their locations and drivers’ availability. This increased demand has raised questions about how such a new matching mechanism will affect the efficiency of the transportation system—in particular, whether it will help reduce passengers’ average waiting time compared with traditional street-hailing systems. Academic/practical relevance: The on-demand ride-hailing problem has gained much academic interest recently. The results we find in the ride-hailing system have a significant …

Routing Policy Choice Prediction In A Stochastic Network: Recursive Model And Solution Algorithm, Tien Mai, Xinlian Yu, Song Gao, Emma Frejinger

Research Collection School Of Computing and Information Systems

We propose a Recursive Logit (STD-RL) model for routing policy choice in a stochastic time-dependent (STD) network, where a routing policy is a mapping from states to actions on which link to take next, and a state is defined by node, time and information. A routing policy encapsulates travelers’ adaptation to revealed traffic conditions when making route choices. The STD-RL model circumvents choice set generation, a procedure with known issues related to estimation and prediction. In a given state, travelers make their link choice maximizing the sum of the utility of the outgoing link and the expected maximum utility until …

A Learning And Optimization Framework For Collaborative Urban Delivery Problems With Alliances, Jingfeng Yang, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

The emergence of e-Commerce imposes a tremendous strain on urban logistics which in turn raises concerns on environmental sustainability if not performed efficiently. While large logistics service providers (LSPs) can perform fulfillment sustainably as they operate extensive logistic networks, last-mile logistics are typically performed by small LSPs who need to form alliances to reduce delivery costs and improve efficiency, and to compete with large players. In this paper, we consider a multi-alliance multi-depot pickup and delivery problem with time windows (MAD-PDPTW) and formulate it as a mixed-integer programming (MIP) model. To cope with large-scale problem instances, we propose a two-stage …

The Empathetic Car: Exploring Emotion Inference Via Driver Behaviour And Traffic Context, Shu Liu, Kevin Koch, Zimu Zhou, Simon Foll, Xiaoxi He, Tina Menke, Elgar Fleisch, Felix Wortmann

Research Collection School Of Computing and Information Systems

An empathetic car that is capable of reading the driver’s emotions has been envisioned by many car manufacturers. Emotion inference enables in-vehicle applications to improve driver comfort, well-being, and safety. Available emotion inference approaches use physiological, facial, and speech-related data to infer emotions during driving trips. However, existing solutions have two major limitations: Relying on sensors that are not built into the vehicle restricts emotion inference to those people leveraging corresponding devices (e.g., smartwatches). Relying on modalities such as facial expressions and speech raises privacy concerns. By contrast, researchers in mobile health have been able to infer affective states (e.g., …

Multi-Stage Stochastic Optimization And Reinforcement Learning For Forestry Epidemic And Covid-19 Control Planning, Sabah Bushaj

Dissertations

This dissertation focuses on developing new modeling and solution approaches based on multi-stage stochastic programming and reinforcement learning for tackling biological invasions in forests and human populations. Emerald Ash Borer (EAB) is the nemesis of ash trees. This research introduces a multi-stage stochastic mixed-integer programming model to assist forest agencies in managing emerald ash borer insects throughout the U.S. and maximize the public benets of preserving healthy ash trees. This work is then extended to present the first risk-averse multi-stage stochastic mixed-integer program in the invasive species management literature to account for extreme events. Significant computational achievements are obtained using …

Stochastic Programming And Agent-Based Simulation Approaches For Epidemics Control And Logistics Planning, Xuecheng Yin

Dissertations

This dissertation addresses the resource allocation challenges of fighting against infectious disease outbreaks. The goal of this dissertation is to formulate multi-stage stochastic programming and agent-based models to address the limitations of former literature in optimizing resource allocation for preventing and controlling epidemics and pandemics. In the first study, a multi-stage stochastic programming compartmental model is presented to integrate the uncertain disease progression and the logistics of resource allocation to control a highly contagious infectious disease. The proposed multi-stage stochastic program, which involves various disease growth scenarios, optimizes the distribution of treatment centers and resources while minimizing the total expected …

Constructive Solution Methodologies To The Capacitated Newsvendor Problem And Surrogate Extension, Pinyuan Shan

Dissertations

The newsvendor problem is a single-period stochastic model used to determine the order quantity of perishable product that maximizes/minimizes the profit/cost of the vendor under uncertain demand. The goal is to fmd an initial order quantity that can offset the impact of backlog or shortage caused by mismatch between the procurement amount and uncertain demand. If there are multiple products and substitution between them is feasible, overstocking and understocking can be further reduced and hence, the vendor's overall profit is improved compared to the standard problem. When there are one or more resource constraints, such as budget, volume or weight, …

Problems Of Modeling And Control Of The Technological Process Of Ore Grinding, Djalolitdin Pakhritdinovich Mukhitdinov, Sanjar Boybutayev

Chemical Technology, Control and Management

The article analyzes the methods of mathematical modeling of the closed-loop process of fine grinding of ore in order to predict the composition of the crushed raw material. Analyzed modeling methods that consider the control of classification of crushed raw materials and finished products by the size of the recirculating load, simulation modeling methods, methods that use neuro-phase netthe research apparatus, in which the fuzzy logic apparatus serves as a fundamental component for the formation of conclusions. The materials presented in the article reflect the theoretical substantiation and generalization of the accumulated practical experience in modeling and control of the …

Structural-Parametric Analysis And Synthesis Of Control Systems With Two Degrees Of Freedom, Azizbek Nodirbekovich Yusupbekov, Khurshid Salim Ugli Turayev

Chemical Technology, Control and Management

Automatic tuning of the parameters of PID - regulators is proposed by means of a modified experiment that takes into account the influence of elements and circuits in the form of additive uncertainty. The use of a multiply connected control scheme with two degrees of freedom for decoupling is proposed in order to facilitate the implementation of a mechanism for combating the phenomenon of integral saturation. Equations are derived for the transition from a circuit with one degree of freedom to a circuit with two degrees of freedom for the general and special cases of a two-dimensional system, which makes …