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Articles 1441 - 1470 of 2141

Full-Text Articles in Operations Research, Systems Engineering and Industrial Engineering

An Unstable Balance: Exploration, Exploitation, And Innovation Decline During Development, Craig Randall Jan 2012

An Unstable Balance: Exploration, Exploitation, And Innovation Decline During Development, Craig Randall

2012

he ability to innovate is considered central to firm performance and the consensus is that firms should balance exploration and exploitation innovation to succeed. Studies using an exploration/exploitation perspective have gained increasing interest, and have generally concluded that exploration innovation rates are too low. Researchers have concentrated on the early aspects of the innovation planning process: the Search, Portfolio Selection, and Design Phase, and have also studied the benefits of pursuing a serial or parallel pursuit of exploration and exploitation. Largely missing from exploration/exploitation innovation literature, however, is the development phase—which is among the longest and resource intensive phases of …


A System Dynamics Model For Simulating Ambulatory Health Care Demands, Rafael Diaz, Joshua G. Behr, Mandar Tulpule Jan 2012

A System Dynamics Model For Simulating Ambulatory Health Care Demands, Rafael Diaz, Joshua G. Behr, Mandar Tulpule

VMASC Publications

Introduction: This article demonstrates the utility of the system dynamics approach to model and simulate US demand for ambulatory health care service both for the general population and for specific cohort subpopulations over the 5-year period, from 2003 to 2008. A system dynamics approach that is shown to meaningfully project demand for services has implications for health resource planning and for generating knowledge that is critical to assessing interventions.

Methods: The study uses a cohort-component method in combination with structural modeling to simulate ambulatory health care utilization. Data are drawn from the National Ambulatory Medical Care Survey and the National …


Epistemic Uncertainty Analysis: An Approach Using Expert Judgment And Evidential Credibility, Patrick Hester Jan 2012

Epistemic Uncertainty Analysis: An Approach Using Expert Judgment And Evidential Credibility, Patrick Hester

Engineering Management & Systems Engineering Faculty Publications

When dealing with complex systems, all decision making occurs under some level of uncertainty. This is due to the physical attributes of the system being analyzed, the environment in which the system operates, and the individuals which operate the system. Techniques for decision making that rely on traditional probability theory have been extensively pursued to incorporate these inherent aleatory uncertainties. However, complex problems also typically include epistemic uncertainties that result from lack of knowledge. These problems are fundamentally different and cannot be addressed in the same fashion. In these instances, decision makers typically use subject matter expert judgment to assist …


Designing Optimal Aviation Baggage Screening Strategies Using The Monkey Search Algorithm, Edgar Ivan Jimenez Jan 2012

Designing Optimal Aviation Baggage Screening Strategies Using The Monkey Search Algorithm, Edgar Ivan Jimenez

Open Access Theses & Dissertations

This thesis addresses the aviation baggage screening design problem considering several baggage screening devices which may be used for system implementation, the devices have different false clear and false alarm rates, throughput and purchase costs. In the present research, a comprehensive cost function which not only includes the cost associated with purchase and operation of baggage security devices, but also includes the indirect costs associated with device errors is used. A new monkey search based evolutionary algorithm is presented to determine the best selection of baggage screening security devices in order to minimize the expected annual total cost. The final …


Multi-Objective System Design Optimization Considering Environmental Emissions, Olivia Carolina Moreno Jan 2012

Multi-Objective System Design Optimization Considering Environmental Emissions, Olivia Carolina Moreno

Open Access Theses & Dissertations

The well-known reliability optimization problem, the redundancy allocation problem (RAP) involves the simultaneous selection of system components and a design level configuration that can meet several design constraints in order to optimize the predefined objective function(s). The RAP has been predominantly solved as a single objective optimization problem with the reliability of the system to be maximized or system design cost to be minimized. When considered as a multiple objective reliability optimization problem, the system reliability is maximized and the cost and weight of the system are minimized. In this work, the RAP was formulated as a multiple objective optimization …


An Integrated Framework For Freight Forwarders:Exploitation Of Dynamic Information For Multimodal Transportation, Farshid Azadian Jan 2012

An Integrated Framework For Freight Forwarders:Exploitation Of Dynamic Information For Multimodal Transportation, Farshid Azadian

Wayne State University Dissertations

Advent of real-time information broadcasting technologies, growth in demand for air-cargo, and increased congestion and variability on air-road network, are the main forces compelling today's air-freight forwarders to improve their operational decision-making to be more competitive and responsive to needs of customers. This research studies the air-cargo transportation on both road (short-haul) and air (long haul) network from the perspective of a mid-size freight forwarder.

We develop a routing algorithm for congestion avoidance on air-network based on historical data and introduce an innovative approach to incorporate real-time information to enable dynamic routing of cargo on a stochastic air-network. In the …


Dock Assignment And Truck Scheduling Problems At Cross-Docking Terminals, Ching-Jung Ting, Amanda G. Rodríguez López Jan 2012

Dock Assignment And Truck Scheduling Problems At Cross-Docking Terminals, Ching-Jung Ting, Amanda G. Rodríguez López

12th IMHRC Proceedings (Gardanne, France – 2012)

In this paper, we consider the integration of dock assignment and truck scheduling problem at cross-docking terminals. The problem is first formulated as a 0-1 integer programming model. Since both dock assignment and truck scheduling problems are NP-hard, its integration is more difficult to solve. Thus we propose reduced variable neighborhood search (RVNS) algorithms to solve the problem. Computational experiments are carried out on four set of instances. The results show that RVNS is capable of finding good solutions in a much shorter computation time when it is compared with optimization solver Gurobi’s solutions.


Ethnic Difference In Healthcare Delivery, Benny Mathew Varghese Dec 2011

Ethnic Difference In Healthcare Delivery, Benny Mathew Varghese

Department of Industrial and Management Systems Engineering: Dissertations, Theses, and Student Research

Quality in healthcare is a very important aspect; this is obtained when there is proper care provided to the patients without any discrimination. The healthcare system in the US can be improved in the fields of patient’s care, the amount of money spent and proper advice, if proper responsibilities are taken. Quality has been improving over the years, but the median by which there is an increase is too small. The other main factor is access to the healthcare system, which has over the year, has not progressed. Studies in healthcare quality should be conducted on a regular base, so …


Office Hour Scheduling Tool, Tyler Dunlap Dec 2011

Office Hour Scheduling Tool, Tyler Dunlap

Industrial Engineering Undergraduate Honors Theses

When an instructor (with or without student input) specifies her office hours for the semester, the informal process used often results in students experiencing conflicts with other lectures, labs, drills, or office hours. The result of this conflict is the student either scheduling individual meetings with teachers outside of their office hours or students missing the opportunity to get assistance from the instructor all together. Either outcome is undesirable, as it either takes additional faculty time from their other responsibilities or jeopardizes the performance of a student in their classes. One valid approach to solving this problem is through the …


Simulation-Based Optimisation Model For The Lean Assessment In Sme: A Case Study, Amr Arisha, Amr Mahfouz, John Shea Dec 2011

Simulation-Based Optimisation Model For The Lean Assessment In Sme: A Case Study, Amr Arisha, Amr Mahfouz, John Shea

Conference papers

Due to their space limitation and small production scale, small and medium enterprises (SME) are vulner-able to rapid changes. Lean principles are considered as effective improvement approach to eliminate sys-tem’s waste and inefficiencies. Although much of the academic materials have addressed the lean practic-es into large, global companies, they can still be adjusted to SMEs. Risks are usually associated with lean implementation process due to the drastic required changes in business policies and operations. Simulation can be successfully used to predict the impact of the proposed changes ahead of the implementation which helps to mitigate risks. Integrating simulation with optimization …


Adaptive Intensity Modulated Radiation Therapy Planning Optimization With Changing Tumor Geometry And Biology Enforcing Both Cumulative And Fraction Size Dose Constraints, Behlul Saka Dec 2011

Adaptive Intensity Modulated Radiation Therapy Planning Optimization With Changing Tumor Geometry And Biology Enforcing Both Cumulative And Fraction Size Dose Constraints, Behlul Saka

Graduate Theses and Dissertations

Intensity Modulated Radiation Therapy (IMRT) is a modern technique of delivering radiation treatments to cancer patients. In IMRT technology, intensities must be chosen for the many small unit grids into which the beams are divided to produce a desired distribution of dose at points throughout the body with the goal of maximizing dose delivered to the tumor while sparing healthy tissues from excessive radiation and keeping dose homogeneous across the tumor. Although IMRT plans are optimized as a single overall treatment plan, they are delivered over 30-50 treatment sessions (fractions) and both cumulative and per-fraction dose constraints apply. The extended …


Improvements On Just-About-Right (Jar) Scales As Product Optimization Tools Using Kano Modeling Concepts, Bangde Li Dec 2011

Improvements On Just-About-Right (Jar) Scales As Product Optimization Tools Using Kano Modeling Concepts, Bangde Li

Graduate Theses and Dissertations

Attribute Kano characteristics are useful in product design to prioritize development efforts. However, attribute Kano characteristics have not been discussed and applied to product optimization when using Just-About-Right (JAR) scales. Product optimizations without identifying attributes Kano characteristics can be misleading. The two objectives in this research were: 1. Determine attribute Kano categories using a modified classic Kano classification methodology. 2. Propose a method to measure attribute performance and identify attribute Kano characteristics to direct product optimization. Two methodologies of attribute Kano classification were investigated. In experiment one, a modified classic Kano methodology was employed to determine attribute Kano categories through …


Inventory Models For Intermittent Highly Variable Demand And Policy Parameter Adjustments To Meet Desired Service Level Requirements, Yasin Unlu Dec 2011

Inventory Models For Intermittent Highly Variable Demand And Policy Parameter Adjustments To Meet Desired Service Level Requirements, Yasin Unlu

Graduate Theses and Dissertations

This dissertation consists of three assays. The first assay examines the robustness of lead time demand models for the continuous review (r;Q) inventory policy. A number of classic distributions as well as distribution selection rules are examined under a wide variety of demand conditions. First, the models are compared to each other by assuming a known demand process and evaluating the errors associated with using a different model. Then, the models are examined using a large sample of simulated demand conditions. Approximation results of inventory performance measures - ready, rate excepted number of backorders and on-hand inventory levels are reported. …


Identification And Classification Of Player Types In Massive Multiplayer Online Games Using Avatar Behavior, Earl M. Bednar Sep 2011

Identification And Classification Of Player Types In Massive Multiplayer Online Games Using Avatar Behavior, Earl M. Bednar

Theses and Dissertations

The purpose of our research is to develop an improved methodology for classifying players (identifying deviant players such as terrorists) through multivariate analysis of data from avatar characteristics and behaviors in massive multiplayer online games (MMOGs). To build our classification models, we developed three significant enhancements to the standard Generalized Regression Neural Networks (GRNN) modeling method. The first enhancement is a feature selection technique based on GRNNs, allowing us to tailor our feature set to be best modeled by GRNNs. The second enhancement is a hybrid GRNN which allows each feature to be modeled by a GRNN tailored to its …


Modeling And Analysis Of High Energy Laser Weapon System Performance In Varying Atmospheric Conditions, Megan P. Melin Sep 2011

Modeling And Analysis Of High Energy Laser Weapon System Performance In Varying Atmospheric Conditions, Megan P. Melin

Theses and Dissertations

This thesis addresses two primary concerns relating to Directed Energy (DE) models and tests: need for more use of Design of Experiment (DOE) in structuring DE models and tests, and lack of modeling atmospheric variability in High Energy Laser (HEL) weapon system propagation models and tests. To address these concerns we use a DOE factorial design to capture main, interaction, and non-linear effects between modeled weapon design and environmental factors in a well defined simulated Air-to-Ground HEL engagement scenario. The scenario modeled considers a B1-B aircraft in the 2022 timeframe equipped with an HEL weapon, irradiating a ground target from …


Characterization Of Key Process Parameters In Injection Blow Molding For Improving Quality, Aspen D'Costa Aug 2011

Characterization Of Key Process Parameters In Injection Blow Molding For Improving Quality, Aspen D'Costa

Online Journal for Workforce Education and Development

The purpose of this study was to discover the performance of significant process parameters in manufacturing 20 oz. plastic beverage bottles. An experimental methodology was carefully designed to examine the characteristics of key variables such as ambient and operating temperatures, process line operators, resin types, resin colors and operating lines associated with a plastic bottle manufacturing line. More explicitly, this study seeks to identify the definitive relationship between the selected process parameters for the production machine (Sidel™) and the ensuing product quality. Also, this study was conducted to evaluate the performance characteristics of Post Consumer Resin (PCR), virgin resin and …


Face Recognition Via Ensemble Sift Matching Of Uncorrelated Hyperspectral Bands And Spectral Pcts, Mohd Fairul Mohd-Zaid Jun 2011

Face Recognition Via Ensemble Sift Matching Of Uncorrelated Hyperspectral Bands And Spectral Pcts, Mohd Fairul Mohd-Zaid

Theses and Dissertations

Face recognition is not a new area of study, but facial recognition using through hyperspectral images is a somewhat new concept which is still in its infancy. Although the conventional method of face recognition using Red-Green-Blue (RGB) or grayscale images has been advanced over the last twenty years, these methods are still shown to have weak performance whenever there are variations or changes in lighting, pose, or temporal aspect of the subjects. A hyperspectral representation of an image captures more information that is available within a scene than a RGB image therefore it is beneficial to study the performance of …


An Optimization Approach To Employee Scheduling Using Fuzzy Logic, William G. Spence Jun 2011

An Optimization Approach To Employee Scheduling Using Fuzzy Logic, William G. Spence

Master's Theses

An Optimization Approach to Employee Scheduling Using Fuzzy Logic

William G. Spence

Selection of sales employees is critical because the sales employees represent the company’s image, competitive advantage, technology, and values. In many service systems the majority of consumer contact is with the sales department. Since there are different types of customers, scheduling quality salespersons who can adequately help consumers may affect revenue.

This thesis proposes a new methodology for the scheduling of employees in a service system. The methodology uses Fuzzy Logic to calculate possible sales and Linear Programming to create an optimal schedule. This approach enables the rating …


A Method To Improve The Sustainment Of Systems Based On Probability And Consequences, Michael Ashton Gaintner Apr 2011

A Method To Improve The Sustainment Of Systems Based On Probability And Consequences, Michael Ashton Gaintner

Engineering Management & Systems Engineering Theses & Dissertations

The FROST Method is presented which improves the efficiency of long-term sustainment of hardware systems. The FROST Method makes sustainment and scheduling decisions based on the minimization of the expected value of current and future costs. This differs from current methods which tend to base decisions not on the expected value of costs, but on the expected inventory demand found through projections using data which is often inaccurate.

Distributions are used to account for randomness and inaccuracy in inputs such as failure rates and vendor-claimed dates for end of production. A Monte Carlo technique is then used to convert these …


A Hybrid Lehmer Code Genetic Algorithm And Its Application On Traveling Salesman Problems, Jun Zhang Apr 2011

A Hybrid Lehmer Code Genetic Algorithm And Its Application On Traveling Salesman Problems, Jun Zhang

Engineering Management & Systems Engineering Theses & Dissertations

Traveling Salesman Problems (TSP) is a widely studied combinatorial optimization problem. The goal of the TSP is to find a tour which begins in a specific city, visits each of the remaining cities once and returns to the initial cities such that the objective functions are optimized, typically involving minimizing functions like total distance traveled, total time used or total cost.

Genetic algorithms were first proposed by John Holland (1975). It uses an iterative procedure to find the optimal solutions to optimization problems.

This research proposed a hybrid Lehmer code Genetic Algorithm. To compensate for the weaknesses of traditional genetic …


Examination Timetabling With Mathematical Programming An Application In Turkish Air Force Academy, Emrah Koksalmis Apr 2011

Examination Timetabling With Mathematical Programming An Application In Turkish Air Force Academy, Emrah Koksalmis

Engineering Management & Systems Engineering Theses & Dissertations

The focus of this thesis is the educational timetabling problem, which is a very challenging problem to solve especially with a high number of the departments, branches, classes, and students. Due to the large scale of educational timetabling problems and preferences of the stakeholders, it is almost impossible to form a general model that solves all of the timetabling problems in the literature. This resulted in the need to develop and employ specific models for specific institutions.

The purpose of this study is to develop a mathematical programming model that solves the examination timetabling problem in Turkish Air Force Academy …


Improving Compressed Air Energy Efficiency In Automotive Plants: Practical Examples And Implementation, Nasr Alkadi, J. Kelly Kissock Apr 2011

Improving Compressed Air Energy Efficiency In Automotive Plants: Practical Examples And Implementation, Nasr Alkadi, J. Kelly Kissock

Mechanical and Aerospace Engineering Faculty Publications

The automotive industry is the largest industry in the United States in terms of the dollar value of production [1]. U.S. automakers face tremendous pressure from foreign competitors, which have an increasing manufacturing presence in this country. The Big Three North American Original Equipment Manufacturers (OEMs)-General Motors, Ford, and Chrysler-are reacting to declining sales figures and economic strain by working more efficiently and seeking out opportunities to reduce production costs without negatively affecting the production volume or the quality of the product. Successful, cost-effective investment and implementation of the energy efficiency technologies and practices meet the challenge of maintaining the …


Optimization Models And Approximate Algorithms For The Aerial Refueling Scheduling And Rescheduling Problems, Sezgin Kaplan Apr 2011

Optimization Models And Approximate Algorithms For The Aerial Refueling Scheduling And Rescheduling Problems, Sezgin Kaplan

Engineering Management & Systems Engineering Theses & Dissertations

The Aerial Refueling Scheduling Problem (ARSP) can be defined as determining the refueling completion times for fighter aircrafts (jobs) on multiple tankers (machines) to minimize the total weighted tardiness. ARSP can be modeled as a parallel machine scheduling with release times and due date-to-deadline window. ARSP assumes that the jobs have different release times, due dates, and due date-to-deadline windows between the refueling due date and a deadline to return without refueling. The Aerial Refueling Rescheduling Problem (ARRP), on the other hand, can be defined as updating the existing AR schedule after being disrupted by job related events including the …


Optimizing Ground Times For Amc Aircraft In Afghanistan, Eric W. Bucheit Jr. Mar 2011

Optimizing Ground Times For Amc Aircraft In Afghanistan, Eric W. Bucheit Jr.

Theses and Dissertations

This research provides insight into the cargo unloading and loading process and times at three airfields in Afghanistan. Using a linear regression model and its prediction capability, a more stabilized environment is produced. This uses the times from seven historical months of continuous operations in Afghanistan and uses this information for the prediction expressions. Using this model, no throughput is lowered and early and late times are lowered by an average of seven minutes per mission. Over the course of a month, this increases planning stability by 74.1 hours. This not only impacts the planning at the downrange location, but …


Utilizing Social Network Analysis In Support Of Nation Building, Brandon J. Bernardoni Mar 2011

Utilizing Social Network Analysis In Support Of Nation Building, Brandon J. Bernardoni

Theses and Dissertations

Social network analysis is a powerful set of techniques used by social scientists to study the formal and informal interrelations in a community. Since 9/11 these techniques have been increasingly utilized by the defense and intelligence communities to analyze terrorist networks to aid in thwarting our foes. This study investigates the use of social networks and structural holes to facilitate nation building in failed and failing states. Investigation of the underlying social structure of a community, identifying st ructural holes and gaps within the government, Security Stabilization Transition and Reconstruction Operations (SSTRO) efforts can be focused to strengthen the host …


Determining Pilot Manning For Bomber Longevity, Jason S. Hamilton Mar 2011

Determining Pilot Manning For Bomber Longevity, Jason S. Hamilton

Theses and Dissertations

In support of US Air Force efforts to conserve resources without sacrificing capability, this research examines the question of whether the 509th Bomb Wing could continue to provide maximum combat capability with fewer assigned pilots. During peacetime, pilot proficiency training comprises the majority of annual flying hours for the small B-2 bomber fleet. Optimal pilot manning will decrease the accumulation of excess wear on the airframes; helping to extend the viable life of the B-2 fleet and preserve the deterrent and combat capabilities that it provides to the United States. The operations and maintenance activity flows for B-2 aircraft and …


Tailoring The Statistical Experimental Design Process For Lvc Experiments, Casey L. Haase Mar 2011

Tailoring The Statistical Experimental Design Process For Lvc Experiments, Casey L. Haase

Theses and Dissertations

The use of Live, Virtual and Constructive (LVC) Simulation environments are increasingly being examined for potential analytical use particularly in test and evaluation. The LVC simulation environments provide a mechanism for conducting joint mission testing and system of systems testing when scale and resource limitations prevent the accumulation of the necessary density and diversity of assets required for these complex and comprehensive tests. The statistical experimental design process is re-examined for potential application to LVC experiments and several additional considerations are identified to augment the experimental design process for use with LVC. This augmented statistical experimental design process is demonstrated …


Measure Of Effectiveness For Jstars Ground Moving Target Indicator: A Value Focused Thinking Approach, Gardner J. Joyner Mar 2011

Measure Of Effectiveness For Jstars Ground Moving Target Indicator: A Value Focused Thinking Approach, Gardner J. Joyner

Theses and Dissertations

As the nature of warfare has shifted from a conventional approach to more guerilla type warfare, intelligence has become more important than at any other time in the history of the United States Military. With the stochastic nature of intelligence gathering, it is almost impossible to know with any degree of certainty where and when the next piece of information that could possibly change the course of the battle or war will be obtained. US intelligence gathering assets have long been plagued with using useless measures of performance rather than measures of effectiveness to determine their worth. This research uses …


A Methodology Using Simulation Results For Test And Evaluation, Jonathon S. Hosket Mar 2011

A Methodology Using Simulation Results For Test And Evaluation, Jonathon S. Hosket

Theses and Dissertations

Each year the Air Force spends billions of dollars on Test and Evaluation to ensure acquisition programs roll out the best possible products. In 1997, the National Research Council assembled to evaluate the overall procedure used in procuring various platforms with system planning, research, development and engineering (SPRDE) and program management (PM) processes. In their final report, they claimed that the full advantages of statistical practices, simulation, model-test-models, and incorporation of prior test information into current test practices have not been fully utilized. To examine one of the report's recommendations, this thesis defines and explores a methodology using simulation to …


Optimal Ch-47 And C-130 Workload Balance, Dustin P. Jones Mar 2011

Optimal Ch-47 And C-130 Workload Balance, Dustin P. Jones

Theses and Dissertations

The Air Force can save thousands of dollars by reducing the number of blade hours on the CH-47 through finding an optimal mixture of CH-47s and C-130s to conduct current operations in Afghanistan and Iraq. Ultimately these savings will relieve maintenance operations for the CH-47 and lengthen the lifespan of the CH-47 airframe. Moreover, incorporating C-130s into the operations will reduce cargo transit time from supply depots. This study looks at the involvement of the C-130 in CH-47 airlift operations to reduce CH-47 usage and increase supply efficiency. The research focus is narrowed to current airlift operations in Afghanistan and …