Engineering Commons^™

Simulation Activity Diagrams, John Ryan, Cathal Heavey

Conference papers

This paper presents a technique, Simulation Activity Diagrams (SAD), developed to lessen the modelling burden during the initial requirements gathering phases of a simulation project. The technique also allows the capture and visual communication of detailed information, to manufacturing personnel, which may otherwise be lost in detailed programming code.

An Industrial Food Processing Plant Automation Using A Hybrid Of Pi And Fuzzy Logic Control, Ganesh K. Venayagamoorthy, D. Naidoo, P. Govender

Electrical and Computer Engineering Faculty Research & Creative Works

An industrial food processing plant consisting of nonlinear dynamics requires pressure and temperature controllers to be nonlinear. In this paper, nonlinear controllers are designed using fuzzy logic to augment the conventional pressure and temperature PI controllers for an industrial food processing plant. Simulation results are presented to show improvement in the plant response with the hybrid controllers.

Evaluation Of Scheduling Strategies On The Performance Of A Flexible Manufacturing Cell:A Simulation Study, Amr Arisha, Paul Young, Mohie El Baradie

Conference papers

The current trend in semiconductor manufacturing is characterized by expanding product variety, decreasing lead times from order to delivery, exacting standards of quality, and competitive prices. One possible means of achieving this is in the form of increased flexibility. Providing flexibility is typically an expensive proposition so, industrial engineers aim to provide more economic approaches to enable flexible manufacturing cells and related equipment to operate appropriately in an efficient manner. It is essential to characterize these tools in detail before the production plans are finalized. Using state-of-the-art computer simulation, a generic model of photolithography tools has been developed. The model …

Development Of Vehicle Platoon Distribution Models And Simulation Of Platoon Movements On Indiana Rural Corridors, Yi Jiang, Shou Li, Daniel E. Shamo

JTRP Technical Reports

Since the 1980s, traffic volumes have experienced a rapid growth of approximately 30% in Indiana. Traffic data indicates that more than 70% of vehicles travel in platoons on Indiana highway corridors in the vicinity of urban areas. At a rural highway intersection consisting of a major road with high traffic volume and a minor road with low traffic volume, it is very common that the green time cannot be used efficiently, especially when the vehicle detectors on the major road are imbedded close to the intersection. In Indiana, most of the traffic signal timing systems operate well. However, these systems …

Somos Simulation/Optimization Modeling System, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

SOMOS (Simulation / Optimization Modeling System) is a family of simulation / optimization (S/O) modules to aid in optimally managing water resources. SOMOS results from twenty years experience developing optimization models and applying them to real-world problems, including 11 pump-and-treat (PAT) systems and numerous water supply problems. SOMOS significantly improves water management or designs and saves money. Its user’s manual provides excellent training in principles of applying optimization to managing aquifer and stream-aquifer systems. It is being incorporated with powerful groundwater modeling and visualization packages.

Practical Simulation /Optimization Modeling For Groundwater Quality And Quantity Management, Richard C. Peralta, Ineke M. Kalwij, Shengjun Wu

Civil and Environmental Engineering Faculty Publications

Software for mathematically optimizing groundwater management has improved significantly in recent years. The SOMOS code can readily handle large complex plume and water management problems. Most recently, it developed a least-cost $40.82M 30-yr pumping strategy for the 6.58 mile long Blaine NAD plume. That strategy was 19 percent better than the strategy developed simultaneously by an experienced consultant using normal trial and error simulation procedures. The management problem involved 60 stress periods, and well installation and pumping rates that could change every 10 periods. The optimal strategy employed 10 new wells. At a simpler site, SOMOS helped select robust strategies …

Field Testing And Computer Modeling To Characterize The Energy Impacts Of Air Handler Leakage, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

In order to determine the impact of air handler location upon heating and cooling energy use, the amount of air leakage which occurs in the air handler cabinet needs to be known. Also, the leakage which occurs at the connections between the air handler cabinet and the return and supply plenums needs to be known as well because these connection leaks would also be located in the attic or any other location.

In order to assess this leakage, testing was performed on a total of 69 air conditioning systems. Thirty systems were tested in the year 2001 under funding from …

A Simulation Study To Investigate Runway Capacity Using Taam, Prakash Subramanian

Master's Theses - Daytona Beach

This study outlines a method to evaluate runway layouts using simulation, to aid in the airport planning and decision making process. As a sample study, the maximum throughput capacities of proposed expansion alternatives at Philadelphia International Airport (PHL), constrained at varying levels, are identified. The objective is to compare the ultimate airport capacities achievable for each of the different layouts to estimate their respective efficiencies in terms of runway system utilization. Given its capabilities for modeling at a very high level of detail and closely representing reality in terms of applicable separation standards and air traffic control procedures, TAAM (Total …

Critical Loading Events For The Assessment Of Medium Span Bridges, Colin C. Caprani, S. A. Grave, E. J. O'Brien, A. J. O'Connor

Conference papers

This paper describes the simulation of free-flowing traffic across bridges to predict the characteristic values for bridge load effects such as bending moment and shear force. The results of these simulations are then used to demonstrate that, in predicting the characteristic extreme load effects to which a bridge may be subjected, it is not sufficient to solely model one-or two-truck presence events. It is shown that loading events involving three or more trucks may need be included in the model for short to medium spans. The critical loading events for a particular load effect are strongly dependent on the span …

Flow Shop Scheduling Problem: A Computational Study, Amr Arisha, Paul Young, Mohie El Baradie

Conference papers

A computational study has been developed to obtain optimal / near optimal solution for the flow shop scheduling problem with make-span minimization as the primary criterion and the minimization of either the mean completion time, total waiting time or total idle time as the secondary criterion. The objective is to determine a sequence of operations in which to process ‘n’ jobs on ‘m’ machines in same order (flow shop environment) where skipping is allowed. The Simulation approach for deterministic and stochastic flow shop scheduling has been developed. It reads and manipulates data for 500 jobs on 500 machines. Different factorial …

A Physically Based Two-Dimensional Infiltration Model For Furrow Irrigation, Christopher J. Skonard, Derrel L. Martin

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

A two-dimensional physically based infiltration model was developed for furrow
irrigation. Infiltration was simulated using the Green-Ampt infiltration method. The Green-Ampt infiltration parameters are available from numerous sources, unlike the Kostiakov infiltration parameters. Simulation tests showed the two-dimensional model capable of estimating cumulative infiltration volume within 8% compared to simulated infiltration using the finite element model, Hydrus-2D. Application of the two-dimensional model in a surface irrigation advance model allows irrigation performance parameters to be predicted without extensive soil experiments.

Physical-Statistical Modeling And Optimization Of Cardiovascular Systems, Dongping Du

USF Tampa Graduate Theses and Dissertations

Heart disease remains the No.1 leading cause of death in U.S. and in the world. To improve cardiac care services, there is an urgent need of developing early diagnosis of heart diseases and optimal intervention strategies. As such, it calls upon a better understanding of the pathology of heart diseases.

Computer simulation and modeling have been widely applied to overcome many practical and ethical limitations in in-vivo, ex-vivo, and whole-animal experiments. Computer experiments provide physiologists and cardiologists an indispensable tool to characterize, model and analyze cardiac function both in healthy and in diseased heart. Most importantly, simulation modeling empowers the …

Bayesian Updating Of Simulated Household Travel Survey Data For Small/Medium Metropolitan Areas, Sirisha Murthy Kothuri

LSU Master's Theses

This thesis tests an approach for generating simulated travel survey data that has local characteristics incorporated in it. Travel survey data are generally required for estimating and calibrating travel demand models for a region. The high cost associated with travel surveys puts them beyond the budget of most small/medium MPOs. Therefore simulation of travel survey data provides a viable alternative for these data starved regions to generate data. The simulated data is produced by combining socio-demographic data along with a national survey data set. Updating the simulated data distributions with the distributions obtained by surveying a small sample of local …

Combining Activity-Based Costing With The Simulation Of A Cellular Manufacturing System, Paul Savory, Robert Williams, Rodney Rassmuseun

Department of Industrial and Management Systems Engineering: Faculty Publications

This paper presents an integrated simulation and activity-based management approach for determining the best sequencing scheme for processing a part family through a manufacturing cell. The integration is illustrated on a loop or U-shaped manufacturing cell and a part family consisting of four part types (A, B, C, and D). Production requirements for the cell demand that part batches be processed one type at a time. For example, all part A’s are processed until weekly demand is met, then part B’s, etc. The objective of this example is to determine the best part sequence (e.g., ABCD, DCBA or CABD). In …

Combining Activity-Based Costing With The Simulation Of A Cellular Manufacturing System, Paul Savory, Robert Williams, Rodney Rassmuseun

Department of Industrial and Management Systems Engineering: Faculty Publications

Discrete-event simulation is one of the most effective techniques for analyzing a manufacturing system. Unfortunately, little attention is given to using simulation models to estimate the economic impact of a proposed system configuration. This paper defines how activity-based costing (ABC) concepts can be incorporated into a discrete-event simulation model. Special emphasis is on demonstrating how decision making can be aided by having the simulation create a detailed “Bill of Activity” describing costs associated with manufacturing a part. The integration of ABC and simulation is illustrated by evaluating the impact of a proposed manufacturing cell configuration. The additional costing information aids …

Remediation Simulation/Optimization Demonstrations, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Applications of simulation/optimization (S/0) software to develop contamination remediation strategies include formal remediation optimization using heads and gradients (hydraulics-based) and concentrations (risk-based) constraints. The six reported cases involve pump and treat systems, or pump, treat and re-inject systems, together termed PAT systems. We used S/0 modeling to perform hydraulic optimization for two of the sites and transport optimization for four. For four of the six sites, other parties used normal simulation (S) modeling alone to develop pumping strategies. Comparing the S/0 model-developed strategies with the S model-developed strategies showed S/0 modeling benefits ranging up to: (a) 25 percent reduction in …

Simulation/Optimization Applications And Software For Optimal Ground-Water And Conjunctive Water Management, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Diverse water management simulation/optimization (S/O) experiences promoted the development of many S/O modeling approaches and models. Several of these are being incorporated within the Simulation/Optimization Modeling System (SOMOS). Non-modeler water scientists or engineers can apply one SOMOS module to optimize field-scale groundwater and conjunctive water management. Experienced groundwater modelers can apply other modules to optimally manage complex heterogeneous aquifer and stream-aquifer systems. SOMOS employs a variety of simulation models and approaches and optimization algorithms to optimize flow and contaminant management. SOMOS or its precursor modules have been well proven in real-world projects. Designed for use by consultants, students, academics, and …

Simulation Study And Instability Of Adaptive Control, Zhongshan Wu

LSU Master's Theses

The Minimum-degree Pole Placement algorithm for Self-tuning Regulator design and the Recursive Least-square method and the projection algorithm for plant estimation are studied first in this thesis. Simulation studies for the estimator and controller algorithms are mainly undertaken after describing how to use MATLAB S-function in detail. Not only do Simulation experiments illustrates how and how well the MDPP and RLS algorithms work, but also show how to write and debug MATLAB codes for S-function programs. The robustness of the adaptive control system is intensively discussed subsequently. By using an estimator resistant to the noise contamination, the adaptive control system …

A Web-Based Interface For Storing And Executing Simulation Models, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

The dominance of the Internet in the development of information and communication technology has made Web-based distributed solutions increasingly attractive. Apart from providing other services, the World Wide Web is being looked upon as an environment for hosting modeling and simulation applications. SIMAN is a simulation language that allows users to simulate discrete and continuous systems. In this research, a web-based interface or toolkit has been developed for storing and executing SIMAN simulation models over the Internet. This toolkit consists of a World Wide Web interface to SIMAN and a web-accessible database for storing user models. It provides users an …

A Web-Based Interface For Storing And Executing Simulation Model, Ashu Guru, Paul Savory, Robert Williams

Department of Industrial and Management Systems Engineering: Faculty Publications

The dominance of the Internet in the development ofinformation and communication technology has madeWeb-based distributed solutions increasingly attractive.Apart from providing other services, the World Wide Webis being looked upon as an environment for hostingmodeling and simulation applications. SIMAN is asimulation language that allows users to simulate discreteand continuous systems. In this research, a web-basedinterface or toolkit has been developed for storing andexecuting SIMAN simulation models over the Internet.This toolkit consists of a World Wide Web interface toSIMAN and a web-accessible database for storing usermodels. It provides users an easy-to-use environment fordeveloping text-based simulation models using the SIMANsimulation language. It also …

Rit Process And Device Simulation With Microtec, Charles R. Overbeck

Journal of the Microelectronic Engineering Conference

Microtec, a diffusion-drift model simulator by Siborg Systems, Inc., was used to simulate RIT’s process for a 2-micron NFET (Long Channel), a scaled down NFET (Short Channel), and our new advanced CMOS Process NFET. The accuracy of the simulator was tested with voltage threshold curves, sub-threshold characteristic tests, potential distribution plots, doping profiles, and oxide growth measurements. Microtec proved to be able to easily model RIT’s device performance and process characteristics with only a small amount of modification.

Development Of Closed Loop System Evaluation Equipment And Procedures, Eric J. Nelson, Montasir Abbas, Gary E. Shoup, Darcy M. Bullock

JTRP Technical Reports

Modern traffic control systems are complex entities whose performance should be thoroughly quantified prior to deployment. However, many of the advanced features available with this control equipment, such as preemption and real-time control strategies, are typically proprietary in nature, and therefore not incorporated into standard simulation models. Since it is not desirable for the engineer to learn in a field environment, under live traffic conditions, this research presents a rational procedure for evaluating and validating such control strategies in a laboratory setting. This document explores three aspects of traffic signal systems, which include the advanced control settings for single controller …

The Use Of Two Mixture Fractions To Treat Coal Combustion Products In Turbulent Pulverized-Coal Flames, Daniel V. Flores, Thomas H. Fletcher

Faculty Publications

Previous coal combustion models using assumed-shape PDF's to treat turbulence-chemistry interactions have used only one progress variable to treat products from coal reactions. This assumes that the products of all coal reactions have the same composition. However. the composition of the combustion products of coal particles is known to vary with burnout, especially between devclatilization and char oxidation. In this work, two progress variables were implemented which distinguish between the products of devolatilization and those of char oxidation. This new approach requires as input the specified volatile content and elemental release during devolatilization. The values for these parameters were estimated …

The Dayton Its Demonstration Project: Simulating Existing Conditions, Jill A. Swaynos, Nikiforos Stamatiadis

Kentucky Transportation Center Research Report

The Miami Valley Regional Planning Commission is incorporating an Advanced Traveler Information System to alleviate real-time traffic problems associated with special events at the Ervin J. Nutter Center of the Wright State University. This study of the existing conditions is part of the evaluation plan and addresses two tasks: 1) documentation of the existing conditions; and 2) definition of measures of effectiveness. The existing conditions were depicted with the use of a computer simulation software package, Traffic Software Integrated System and separate scenarios were modeled for three existing conditions: ingress and egress for a special event and a major shopping …

Conversion Of New Circle Road To A Limited Access Highway, Steven M. Henderson, Nikiforos Stamatiadis

Kentucky Transportation Center Research Report

The objectives of this study were to first evaluate the existing traffic conditions along the NE part of New Circle Road and investigate the use of unconventional left turn treatments, as well as other access restrictions to improve the operating conditions of New Circle Road. The alternatives examined include a do-nothing alternative, the addition of one through lane per direction, the use of median U-turns at various locations, and combinations of them. Restrictive left turn strategies proved to be a more successful tool for traffic management on New Circle Road than simply adding a lane in each direction. Using median …

Simulation Modeling Presentations: The Life Cycle, Edward Yellig, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

A typical large scale simulation modeling project spans many months and encompasses activities such as problem definition, data collection, model development, experimentation, and scenario analysis. During the life cycle of a simulation project, numerous presentations are made to many different types of audiences. The purpose of these presentations will vary from seeking project approval, requesting information, discussing simulation model features, verifying the model, validating the model, presenting the experimental results, and offering model conclusions. This paper will discuss presentation techniques we used during a year-long simulation-modeling project. We will highlight techniques used for defining the purpose of each presentation, identifying …

The Effect Of Registration Errors On Tracking In A Networked Radar System, Bradley J. Mortenson

Theses and Dissertations

To successfully combine information from distributed radar sensors, it is essential that each sensor be correctly referenced in a global coordinate system. If there are biases in the reported position of these sensors, the reported target position will also be biased and the ensuing global estimate of the target position will be degraded. Furthermore, any biases in range or azimuth measurements of these sensors will likewise be reflected in the degradation of global estimate of target position. Registration is the process of ensuring that these errors do not result in the creation of an additional redundant target when only a …

8 Bit Analog-To-Digital Converter Design And Simulation, Alberto J. Reyes

Journal of the Microelectronic Engineering Conference

The purpose of this study is to present and characterize an 8 bit AD converter implemented with flash architecture. Flash architecture provides with one of the fastest and easiest ways to convert analog input signals to digital outputs. Analog-to-digital conversion is the process in which a continuously varying analog signal is transformed into a multilevel digital signal. Analogue electrical waveforms are applied to the converter and are sampled at a fixed rate. Sample values are then expressed as a binary number consisting of 0’s and l’s. The resulting digital code can be used to encode digital audio, applications in video …

Road Rescue Implements A Continuous Process Improvement Framework, John Olson, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

Continuous improvement programs traditionally focus on making small incremental improvements to a system. Unfortunately, their success can be limited due to the rapid changing environment within which most small companies operate. Improvement efforts should be flexible enough to capitalize on incremental and radical changes to a system. This paper presents a case analysis of how Road Rescue, an ambulance manufacturer, uses a continuous improvement framework to capitalize on both radical and incremental improvement opportunities. Results include a 10% increase in throughput, reduced cycle time of 44%, increased customer satisfaction, and higher quality.

Using Simulation To Derive Activity-Based Costing Estimates, Paul Savory, Robert Williams

Department of Industrial and Management Systems Engineering: Faculty Publications

This presentation showcases integrating activity based costing into the development of a SIMAN simulation of a manufacturing system.