Operations Research, Systems Engineering and Industrial Engineering Commons^™

Synergistic Decision-Making Systems: Using Models Of Decision-Making Behaviors And Resources To Design Better Decision-Making System, Ronald R. Carter

Masters Theses

Despite advances in decision-making systems, many practical issues remain unaddressed and much of the computer's potential for supporting decisions is unrealized. The existing systems are often limited to specific decision-making activities or domains, and they force the decision-maker to adopt a closed and inflexible way of doing things. What is needed is a new approach to building decision-making systems, one that is not focused on how decisions should be made, but on the behaviors and resources involved in decision-making and how they affect the results. This paper explores such an approach. It examines how models of decision-making behaviors and resources …

Preparing The Leaders For Mechatronics Education, Sema E. Alptekin

Industrial and Manufacturing Engineering

Mechatronics is the synergetic combination of precision mechanical engineering, electronic control and systems thinking in the design of products and processes. There is a need to develop interdisciplinary programs in Mechatronics that better prepare our graduates to design, build, and operate the products and systems of today and tomorrow. To address this need, National Science Foundation funded a project entitled "Preparing the Leaders for Mechatronics Education" undertaken by Cal Poly in 1995 - 1996. In this paper, the activities that took place during this two-year program is outlined. Several courses and course modules have already been developed and implemented by …

A Comparison Of Traffic Models: Part 1, Framework, Hong Lo, Wei-Hua Lin, Lawrence Liao, Elbert Chang, Jacob Tsao

Faculty Publications

This report defines a framework for comparing dynamic traffic models. It emphasizes four dimensions: functionality, traffic dynamics, route choice dy namics, and overall network performance. The first dimension compares the models through a check-list of model functions. Regarding the last three comparison dimensions, a total of five networks and twelve scenarios are defined. These test scenarios are designed to accentuate model properties and differences. Also included in the report are a list of performance measures for comparison purpose, and a discussion of the interpretation of results.

Dynamic Traffic Assignment For Automated Highway Systems: A Two-Lane Highway With Speed Constancy, H.-S. Jacob Tsao

Faculty Publications

Dynamic traffic assignment through analytical modeling and optimization has been widely accepted by the IVHS R&D community as a promising traffic control tool for understanding and relieving traffic congestion on conventional highways and city streets. Due to the completely controlled nature of AHS traffic, dynamic assignment of AHS traffic is even more promising. One added dimension of complexity associated with AHS dynamic traffic assignment is lane assignment. Lane changes, for fully utilizing AHS capacity or for exiting, incur disturbances to and hence reduction of longitudinal flow. Intelligent lane assignment is necessary to ensure a high rate of successful exiting, to …

Applications Of Artificial Neural Networks In Interactive Simulation, Payman Jula

Masters Theses

Although there have been many improvements in simulation technology over the past few years, it still suffers from many limitations. Simulation methods are usually time consuming and hence not suitable for the interactive decision making processes.

In this project, applications of Artificial Neural Networks (ANNs) to simulate manufacturing systems have been studied. The backpropagation Multiple Layer Perceptrons (MLPs) have been applied to simulate manufacturing systems. Some guidelines for developing appropriate ANNs have been presented. The results of ANN approach have been compared to those of conventional simulation methods.

An Artificial Life Model Of Engineering Attrition Contemplation: Why Do Federally Employed Civilian Engineers Think Of Quitting?, John William Herweg

Engineering Management & Systems Engineering Theses & Dissertations

The research objective is, using engineer turnover, to develop an Artificial Life (A-Life) model and simulation methodology useful for studying behavioral variables of individuals in an organization.

One consequence of work stress is burnout, and its extreme expression is quitting or turnover. Various models have been used to explain and predict this behavior. Behavior models are useful tools to explore the ability of organizational policies to reduce stress levels and turnover. Advancing the usefulness of models is a goal which assists all research on human behavior. A-Life offers a new and different methodology for this purpose. It provides an ability …

Dynamic Lot Sizing And Scheduling In A Multi-Item Production System, Padmanabhan Soundar

Engineering Management & Systems Engineering Theses & Dissertations

In this research, algorithms are developed to address the problem of dynamic lot sizing and scheduling in a single level (or single operation) production system. This research deviates from previous research in this area in that it does not have the kind of assumptions regarding the real world production system that normally were made to reduce the complexity of the problem. Specifically, this research explicitly considers finite capacity, multiple items, known deterministic dynamic demand, sequence dependent setup times and setup costs, setup carryover and variable backlogging. The objective is to simultaneously determine the lot size and the sequence of production …

Constraints On Initial Ahs Deployment And The Concept Definition Of A Shuttle Service For Ahs Debut, H.-S. Jacob Tsao

Faculty Publications

The concept of automated highway system (AHS) was motivated primarily by its potential for large capacity and safety gains without requiring significant right-of-way acquisition. However, highway automation involves a multitude of design options as well as systems issues. Compounded by the crucial dimension of evolving the current highway system towards the mature AH& there exist a large number of possible evolutionary paths to AHS. Perhaps due to the immense complexity, little attention has been paid to the evolution dimension.Particularly important and difficult in defining a deployment sequence is the very first step,i.e. the first user service involving fully automated (hands-off …

Stage Definition For Ahs Deployment And An Ahs Evolutionary Scenario, H.-S. Jacob Tsao

Faculty Publications

The concept of automated highway systems (AHS) as a means to solve the fast-worsening highway congestion problem has received renewed attention recently. Pros and cons of various mature AHS have been a subject of intense study. However, such discussions are nothing but intellectual exercises unless the issue of how to evolve the current highway systems towards these mature AHS can be resolved. There exist a large number of different possible mature AHS. The additional dimension of evolution leads to an even larger number of possible evolutionary scenarios. This paper proposes an approach to defining evolutionary scenarios and illustrates it with …

Linear Programming With Inequality Constraints Via Entropic Perturbation, Jacob Tsao, Shu-Cherng Fang

Faculty Publications

A dual convex programming approach to solving linear programs with inequality constraints through entropic perturbation is derived. The amount of perturbation required depends on the desired accuracy of the optimum. The dual program contains only non-positivity constraints. An ϵ-optimal solution to the linear program can be obtained effortlessly from the optimal solution of the dual program. Since cross-entropy minimization subject to linear inequality constraints is a special case of the perturbed linear program, the duality result becomes readily applicable. Many standard constrained optimization techniques can be specialized to solve the dual program. Such specializations, made possible by the simplicity of …

A New Creep-Fatigue Life Prediction Model, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

A published creep-fatigue life prediction model is modified in this paper and assessed with data on Inconel 718 under different test conditions. It has been shown that the method developed within the viscosity concepts correlates the low-cycle fatigue data well. This paper reports the modification over the previous model.

An Investigation Into Manufacturing Execution Systems, K. W. Duley

Theses : Honours

Hardware and software developments of this decade have exposed an hiatus between business/management applications and process control in heavy industry in the implementation of computer technology. This document examines the development of discrete manufacturing and of relevant implementations of computing. It seeks to examine and to clarify the issues involved in a perceived current drive to bridge this gap, to integrate all the systems in a manufacturing enterprise in a Manufacturing Execution System (MES) in order to address two hypotheses: I) That overseas trends towards the development of manufacturing execution systems have application in the Australian industrial context. 2) That …

Cycle Time Estimation For Simulating A Tandem Queueing Systems Using Aggregation Techniques, Paul Savory, Gerald Mackulak

Department of Industrial and Management Systems Engineering: Faculty Publications

One approach to simulating a single-server tandem queuing system is to explicitly model each of the production stages. In this paper, we apply queueing theory, a recursive algorithm, and composite random number sampling to develop an equivalent aggregate representation consisting of only a single production stage. Preliminary test results indicate that the aggregation works well for estimating the mean and variability of the total cycle time.

The Effects Of Post Inoculant Additions On Ductile Iron Fade, Travis James Frush

Dissertations and Theses @ UNI

This study involved the investigation of three specific, commercially available, post inoculants for ductile iron and their effect on the magnesium fading rate and chill reducing tendency in a low volume production environment. Although fading effects of ductile iron have been extensively investigated, in general, they apply to high volume production operations. Unfortunately, for the smaller foundry operations, many of the process solutions proposed for the prevention of the fading effects are not applicable or practical. In addition to the small production operations, new process technologies are also excluded from many of these process solutions. For this reason, a study …

Dynamic Scale Genetic Algorithm: An Enhanced Genetic Search For Discrete Optimization, Bela Dange Joshi

Engineering Management & Systems Engineering Theses & Dissertations

The minimization of operations and support resources of reusable launch vehicles is a complex task, involving discrete optimization and the simulation domain. Genetic algorithms, offering a robust search strategy suitable for integer variables and the simulation domain, can be applied to minimize these resources. This research developed an enhanced genetic algorithm for problems with a linear objective function, the most common class of discrete optimization problems. The dynamic scale genetic algorithm developed here incorporates concepts of implicit enumeration to enhance search. This is achieved by utilizing problem specific information to refine the solution space over successive generations. The utility of …

Cumulative Average Pricing Method For Estimating Average Service Life, Mahendra Babu Hosangadi

Masters Theses

The study determined if accuracy of estimation of retirement price of industrial equipment was affected by using a cumulative average pricing (CAP) method at varying conditions of inflation rate, service life, and life characteristics. The study also determined the accuracy of estimating the average life of unaged data by simulated plant record (SPR) method. Thirty-six experiments were conducted at varying conditions of inflation rate, curve type and average life. The study was conducted for two left modal curves, two symmetrical modal curves and two right modal curves at 20 and 40 years average life using three different inflation rates: 3%, …

Using Mathematica To Aid Simulation Analysis, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

As computer power has increased, so has the capability of software developers to write programs that assist people with time-consuming tasks. Mathematica is such a program. The objective of this paper is to demonstrate how Mathematica, a symbolic programming environment, can be used to aid simulation analysis. In addition to a general discussion of Mathematica’s uses, advantages, and disadvantages, several examples will be presented. The examples include using Mathematica for distribution fitting, queueing analysis, random number generation, and creating a surface plot for optimization.

A Psychological Perspective On Service Segmentation Models: The Significance Of Accounting For Consumers' Perceptions Of Waiting And Service, Ziv Carmon, J. George Shanthikumar, Tali F. Carmon

Industrial and Manufacturing Engineering

We examine how service should be divided and scheduled when it can be provided in multiple separate segments. We analyze variants of this problem using a model with a conventional function describing the waiting cost, that is modified to account for some aspects of the psychological cost of waiting in line. We show that consideration of the psychological cost can result in prescriptions that are inconsistent with the common wisdom of queuing theorists derived according to the conventional approach (e.g., equal load assignments). More generally, our intention in this paper is to illustrate that aspects of the psychological cost of …

System Dynamic Modeling Of Activity And Flow Relationships In Plant Layout Problems, Gary Allen Weaver

Engineering Management & Systems Engineering Theses & Dissertations

The problem of determining an optimal plant layout involves the distribution of machinery, service areas, and storage spaces. The solution is usually determined for a specific period of time and static in nature. Planning for the plant layout is normally performed at the onset of new construction, or major refurbishment of an existing facility. In addition, plant layouts are renewed when a significant productivity decrease is experienced over long periods of time and linked to material flow problems, and when an expanding company plans for major capital expenditures in equipment and space. Due to the dynamic nature of business the …

A Comparison Of Consistent Versus Inconsistent Scheduling Rules In A Flow Shop Environment, Nicola Gismondi

Theses and Dissertations

A consistent scheduling rule is one which will ensure a job's priority (relative to all other job's) will remain constant as it moves from queue to queue in a production system. Previous research concerning flow shop priority scheduling rules focused on comparison of either consistent or inconsistent rules. Conversely, this study sought to provide additional insight by comprising consistent and inconsistent rules in a flow shop environment The Air Force uses both types of rules in maintenance and logistics scheduling. Time and money can be saved if the scheduling managers can better understand the effect of consistency on a system. …

Just In Time Manufacturing: A Migration From Materials Requirements Planning, Scott A. Koehler

Theses and Dissertations

Manufacturing planning and control systems play an important role in an organization's effectiveness. Over the past twenty to thirty years, U.S. manufacturing companies have faced increasing competition for market share from Japanese and other Pacific rim countries. This thesis will investigate the evolutionary path followed by manufacturing companies that have implemented various manufacturing planning and control systems. Specifically, Materials Requirements Planning (MRP) and Just In Time (JIT) production will be analyzed. MRP is a means of convening demand for the final product into a requirements schedule for the various components comprising that product. The JIT philosophy calls for continuously improving …

Traffic Control For Automated Highway Systems: A Conceptual Framework, H.-S. Jacob Tsao

Faculty Publications

This paper proposes a conceptual framework for designing a traffic control scheme. It adopts a top-down approach to defining major design steps starting with high-level feature definition. With the desired features defined, the top-down approach then identifies and defines moves and related planning and movement functions that are required for supporting the desired features. The paper takes a systems view and identifies the safety issues regarding the movement coordination of the large number of vehicles on an Automated Highway System (AHS).

Addition Of Automatic Dimensioning Feature To D-M-E’S Ultimate Mold Base Design Software, Cori L. Brown

Masters Theses

There have been many improvements in the plastics industry over the past few years. One of these areas is in the design of injection molds. This area has been enhanced by the use of Computer-Aided Design systems and furthered by the creation of specialized mold design software. The Ultimate^® design system from D-M-E has made a mold designer's job much easier by automating much of this process. This project extends the function of this software by adding an automatic dimensioning feature that will make the mold design process less tedious and less time consuming. This addition will also standardize …

Development Of A Mold Trial Procedure For Establishing A Robust Process, Marc R. Vander Kooi

Masters Theses

To reduce variation in the injection molding process it is essential to understand the effect of process, mold, and material variables on critical part characteristics. Gaining a thorough understanding of these variables is often difficult due to the limited time manufacturers typically have available for mold trials. To address this issue, the Premier Class Injection Molding consortium (PCIM) has performed numerous experiments relating to shot-to-shot repeatability. Using the PCIM data set and experimentation procedures as a base, a procedure was developed to collect data during a mold trial. Incorporating small experiments and statistical analysis, the new procedure allows meaningful data …

Analysis Of A Design For Its Quality Manufacturability In Terms Of Misalignments And Fastener Related Problems, Abhinav Dhar

Theses

This study analyzes the relationship between design parameters established at the initial stage of the design process and the manufacturing quality problems that manifest themselves during production. Specifically, we study the relationship between design features and the occurrence of misalignment defects and fastener related problems.

This outcome of this work is a methodology, Design for Quality Manufacturability (DFQM). DFQM addresses the likelihood that defects will occur during the manufacture of a product in a standard plant. This is based on the premise that defects in assembled products are often influenced by some features of the design and/or assembly process. These …

Effects Of Ergonomic Worksite Changes On Risks For Cumulative Trauma Disorders Of The Upper Body In An Assembly And Press Operation Job, David B. Mahone

Theses

Cumulative trauma of the upper body is associated with a variety of individual and job factors. An effort to optimize the human-hardware interface to minimize cumulative trauma is favored. Workers in a set of jobs had complained about hand/wrist and shoulder discomfort. One job was selected for testing alternate machine controls and worksite layout. Electromyography was used to test muscle activity, and photogoniometry was used to measure posture.

For the group of ten worker-subjects, statistically significant decreases in hand/wrist and shoulder muscle activity were found. A marginal, but significant increase in neck muscle activity was also found. When one subject …

Development Of A Knowledge-Based System For Generating Process Plans Using Group Technology: A Study For Norfolk Naval Shipyard, William P. Keene Jr.

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this research was to study and analyze the Norfolk Naval Shipyard's manufacturing methods of determining part families and generating part process plans for parts in the machine shop. A knowledge-based decision support system was designed based on knowledge acquired from machinist experts and documented sources of the Norfolk Naval Shipyard. The system interprets specific part information provided by the user, categorizes parts into part families and generates process plans to manufacture the parts. The system was evaluated and tested for parts provided by Norfolk Naval Shipyard.

A Discrete Single Server Queue With Markovian Arrivals And Phase Type Group Services, Attahiru Sule Alfa, K. Laurie Dolhun, Srinivas R. Chakravarthy

Industrial & Manufacturing Engineering Publications

We consider a single-server discrete queueing system in which arrivals occur according to a Markovian arrival process. Service is provided in groups of size no more than M customers. The service times are assumed to follow a discrete phase type distribution, whose representation may depend on the group size. Under a probabilistic service rule, which depends on the number of customers waiting in the queue, this system is studied as a Markov process. This type of queueing system is encountered in the operations of an automatic storage retrieval system. The steady-state probability vector is shown to be of (modified) matrix-geometric …

A Staggered-Diamond Design For Automated/Manual-Hov Highway-To-Highway Interchanges And Constraints On Ahs Design For Accommodating Automated Highway Change, Jacob Tsao

Faculty Publications

This paper consists of two components. The First component addresses a key AHS infrastructure support issue—providing eight extra connector ramps, in addition to the eight existing highway-to-highway connector ramps for the conventional manual traffic, at a highway-to-highway interchange for accommodating continuous automated driving from one highway to the crossing highway. The proposed staggered-diamond design requires only four, instead of eight, separate structures and hence greatly increases the feasibility of AHS infrastructure support. However, the reduced infrastructure complexity at such interchanges could still constrain considerably the design, operation and evolution of AHS. This is the focus of the second component. The …

Stage Definition For Ahs Deployment And An Ahs Evolutionary Scenario, Jacob Tsao

Faculty Publications

Pros and cons of various mature Automated Highway Systems (AHS) have been a subject of intense study. However, such discussions are nothing but intellectual exercises unless the issue of how to evolve, in a planned and managed fashion, the current highway systems towards these mature AHS is also addressed. Since full functionality of a mature AHS cannot be realized suddenly, discrete functional steps must be identified and optimized. This paper defines an evolutionary stage towards a mature AHS as any discernible functional increment whose realization may encounter considerable difficulties requiring a significant amount of conscious effort to overcome. A good …