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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Using statistical process control to monitor inventory accuracy

Huschka, Kyle January 1900 (has links)
Master of Science / Department of Industrial & Manufacturing Systems Engineering / John R. English / Inventory accuracy is critical for almost all industrial environments such as distribution, warehousing, and retail. It is quite common for companies with exceptional inventory accuracy to use a technique called cycle counting. For many organizations, the time and resources to complete cycle counting are limited or not available. In this work, we promote statistical process control (SPC) to monitor inventory accuracy. Specifically, we model the complex underlying environments with mixture distributions to demonstrate sampling from a mixed but stationary process. For our particular application, we concern ourselves with data that result from inventory adjustments at the stock keeping unit (SKU) level when a given SKU is found to be inaccurate. We provide estimates of both the Type I and Type II errors when a classic c chart is used. In these estimations, we use both analytical as well as simulation results, and the findings demonstrate the environments that might be conducive for SPC approaches.
2

Theoretically and computationally improving branch and bound through multivariate branching with internal cutting planes

Lee, Jin Hua January 1900 (has links)
Master of Science / Department of Industrial & Manufacturing Systems Engineering / Todd W. Easton / Integer Programs (IP) are a class of discrete optimization problems that are utilized commercially to improve the function of various systems. Implementation is often aimed at reaching optimal financial objectives with constraints on resources and operation. While incredibly beneficial, IPs are NP-complete, with many IP models being unsolvable. Branch and bound (BB) is the primary method employed to solve IPs to optimality. BB is an exhaustive approach to enumerating all potential integer solutions for a given IP. By utilizing a hierarchical tree structure to tabulate progression of enumeration, BB can guarantee an optimal solution in finite time. However, BB can take an exponential number of iterations to solve an IP. Computationally, this can result in a tree structure that exceeds a computer’s memory capacity, or a prohibitively long solution time. This thesis introduces a modified version of BB call the Quaternary Hyperplane Branching Algorithm (QHBA). QHBA employs a quaternary branching scheme, utilizes hyperplane branching constraints, and generates internal cutting planes to increase efficiency. Implementation of these advancements theoretically improves QHBA in comparison to traditional BB. It can also be shown that QHBA guarantees an optimal solution in a finite number of iterations. A short computational study shows that QHBA results in a 26.7% decrease in solution times when compared to CPLEX, a commercially available IP solver.
3

Optimizing defensive alignments in baseball through integer programming and simulation

Becker, Kyle William January 1900 (has links)
Master of Science / Department of Industrial & Manufacturing Systems Engineering / Todd W. Easton / Baseball is an incredibly complex game where the managers of the baseball teams have numerous decisions to make. The managers are in control of the offense and defense of a team. Some managers have ruined their teams’ chances of a victory by removing their star pitcher too soon in a game or leaving them in too long; managers also choose to pinch hit for batters or pinch run for base runners in order to set up a “favorable match-up” such as a left handed pitcher versus a right handed batter. This research’s goal is to aid managers by providing an optimal positioning of defensive players on the field for a particular batter. In baseball, every ball that is hit onto the field of play can be an out if the fielders are positioned correctly. By positioning the fielders in an optimal manner a team will directly reduce the number of runs that it gives up, which increases the chances of a win. This research describes an integer program that can determine the optimal location of defensive players. This integer program is based off of a random set of hits that the player has produced in the past. The integer program attempts to minimize the expected costs associated with each hit where the cost is defined by a penalty (single, double or triple) or benefit (out) of the person’s hit. By solving this integer program in Opl Studio 4.2, a commercial integer programming software, an optimal defensive positioning is derived for use against this batter. To test this defense against other standard defenses that teams in the MLB currently use, a simulation was created. This simulation uses Derek Jeter’s actual statistics; including his 2009 regular season hit chart. The simulation selects a hit at random according to his hit chart and determines the outcome of the hit (single, double, out, double play, etc.). Once this simulation is complete a printout shows the batter’s statistics; including his average and slugging percentage. VI By comparing the optimized defensive alignment with some commonly used major league alignments, it can be shown that this optimal alignment would decrease Jeter’s average by nearly 13% and decrease his slugging by 35%. It is my opinion that managers should use this tool to help them win more games. These defenses can be seamlessly implemented by any coach or team.
4

Three set inequalities in integer programming

McAdoo, Michael John January 1900 (has links)
Master of Science / Department of Industrial & Manufacturing Systems Engineering / Todd W. Easton / Integer programming is a useful tool for modeling and optimizing real world problems. Unfortunately, the time required to solve integer programs is exponential, so real world problems often cannot be solved. The knapsack problem is a form of integer programming that has only one constraint and can be used to strengthen cutting planes for general integer programs. These facts make finding new classes of facet-defining inequalities for the knapsack problem an extremely important area of research. This thesis introduces three set inequalities (TSI) and an algorithm for finding them. Theoretical results show that these inequalities will be of dimension at least 2, and can be facet defining for the knapsack problem under certain conditions. Another interesting aspect of these inequalities is that TSIs are some of the first facet-defining inequalities for knapsack problems that are not based on covers. Furthermore, the algorithm can be extended to generate multiple inequalities by implementing an enumerative branching tree. A small computational study is provided to demonstrate the effectiveness of three set inequalities. The study compares running times of solving integer programs with and without three set inequalities, and is inconclusive.
5

Evaluation of different safety aspects of centerline rumble strips

VijayaKumar, Arun January 1900 (has links)
Master of Science / Department of Industrial & Manufacturing Systems Engineering / Malgorzata J. Rys / In this thesis, various safety aspects of center line rumble strips were evaluated. Based on the literature review center line rumble strips (CLRS) are considered to be effective safety countermeasure for reducing crossover accidents on two-lane, two-way roadways. CLRS are indentations milled into the center line of undivided two-lane, two-way roadways to warn driver of drifting into upcoming traffic. Researchers at Kansas State University (KSU) have conducted studies on CLRS and retroreflective pavement markings (RRPM) installed over them. Based on the literature review and the survey conducted on motorcycle riders it can be concluded that majority of riders believe in the effectiveness of CLRS and they recommend the KDOT to implement CLRS in more locations. From the survey conducted on residents of US 40 it can be concluded that RRPM help them in providing visual guidance. They also noticed that there is considerable deterioration of RRPM over CLRS on US 40. From the studies conducted on US 24, US 50 and US 40 it can be concluded that wet retroreflectivity of pavement markings installed over CLRS is considerably lower than dry retroreflectivity. In locations without CLRS wet retroreflectivity of RRPM is higher than dry retroreflectivity. Also, the analysis performed on retroreflectivity measurements from US 24, US 50 and US 40 show that retroreflectivity follows a linear reduction in performance over time. In addition, a new methodology was developed for evaluating RRPM over CLRS. Various tests and analysis were performed and the new method seems effective.
6

Evaluation of external noise produced by vehicles crossing over centerline rumble strips on undivided highways in Kansas

Makarla, Rohit January 1900 (has links)
Master of Science / Department of Industrial & Manufacturing Systems Engineering / Malgorzata J. Rys / Centerline rumble strips (CLRS) are raised or indented patterns installed in the center of undivided rural two-lane highways. Their main function is to alert drivers who are encroaching or leaving the intended travel lane, by producing vibration and noise when crossed by vehicles’ tires. CLRS have been demonstrated to be an effective way in reducing head on and opposite direction sideswipe on two-lane highways (cross-over accidents). However, there are some disadvantages in their utilization, such as the exterior noise created by the strips, which may disturb residents in the highway vicinity. The objective of this study was to verify if the amount of noise created by CLRS is enough to impact negatively on residences and businesses, and to discover if the mean level of noise created by CLRS is statistically different than the noise generated by vehicles driving over smooth pavement. Two types of vehicles were driven over two different patterns of milled-in CLRS (rectangular and football-shaped) and over smooth asphalt pavement, at two different speeds. Researchers collected the noise levels at three distances 50, 100, and 150 feet, measured orthogonally from the center line, in 8 different open space locations. Results indicate that vehicle type, vehicle speed, pavement type, location and distances affect the levels of noise. In addition, both football and rectangular CLRS produced significantly higher levels of noise as compared to the smooth asphalt pavement. A 15 passenger van produced higher levels of noise in comparison with a sedan. Moreover, lower the vehicle speed, noise levels were lower. At every 50 feet of distance, the noise levels dropped significantly. CLRS do increase levels of noise relative to smooth pavement at distances up to 150 feet.
7

Simulating traffic flow for emergency evacuation in Manhattan, KS using Rockwell ARENA

Davis, Kathryn January 1900 (has links)
Master of Science / Department of Industrial & Manufacturing Systems Engineering / Malgorzata J. Rys / The community of Manhattan, Kansas was recently chosen as the future site of the National Bio- and Agro-Defense Facility (NBAF). At this site, research of agricultural and animal diseases and pathogens will take place. Due to the fact that the site will be in close proximity to a university, as well as many residents, a risk assessment must be completed to determine whether or not the current road infrastructure would be sufficient for evacuating the city in the event of an emergency. It should be noted that while NBAF is a large concern for this report, risk management is important in other scenarios as well, such as natural disasters or chemical spills, and this information can be applied to such events. This paper discusses the creation and analysis of a discrete-event simulation using ARENA software. The simulation described several scenarios. They were a base case scenario with only campus traffic evacuating; a scenario in which campus and outside traffic evacuate; a case with increased outside traffic; a case in which a vehicle breaks down; a case which includes guardians of children attending campus childcare are re-routed to pick up their children before evacuating; a case which accounts for reduced traveling speeds due to cell phone usage; and a case which closes a direction outside of Manhattan due to wind direction. Such simulations are an ideal performance measure of traffic flow under certain conditions due to the fact that physical resources are not needed to make a realistic comparison between each of them. Each of the situations described above were compared based on percentage of traffic leaving Manhattan and arriving at a defined safe zone each hour. Based on the findings, those involved with disaster management planning can determine if the percentages of vehicles leaving the system per hour are acceptable. They should be evaluated against potential spread rates of diseases to ensure that all residents may evacuate without the danger of becoming infected. For applications outside of NBAF, the results give insight into the degree of change in evacuation percentage that changes within the system may cause, and change any routing accordingly.
8

Consensus in group decision making under linguistic assessments

Chen, Zhifeng January 1900 (has links)
Doctor of Philosophy / Department of Industrial and Manufacturing Systems Engineering / David Ben-Arieh / Group decision-making is an essential activity is many domains such as financial, engineering, and medical fields. Group decision-making basically solicits opinions from experts and combines these judgments into a coherent group decision. Experts typically express their opinion in many different formats belonging to two categories: quantitative evaluations and qualitative ones. Many times experts cannot express judgment in accurate numerical terms and use linguistic labels or fuzzy preferences. The use of linguistic labels makes expert judgment more reliable and informative for decisionmaking. In this research, a new linguistic label fusion operator has been developed. The operator helps mapping one set of linguistic labels into another. This gives decision makers more freedom to choose their own linguistic preference labels with different granularities and/or associated membership functions. Three new consensus measure methods have been developed for group decision making problem in this research. One is a Markov chain based consensus measure method, the other is order based, and the last one is a similarity based consensus measure approach. Also, in this research, the author extended the concept of Ordered Weighted Average (OWA) into a fuzzy linguistic OWA (FLOWA). This aggregation operator is more detailed and includes more information about the aggregate than existing direct methods. After measuring the current consensus, we provide a method for experts to modify their evaluations to improve the consensus level. A cost based analysis gives the least cost suggestion for this modification, and generates a least cost of group consensus. In addition, in this research I developed an optimization method to maximize two types of consensus under a budget constraint. Finally considering utilization of the consensus provides a practical recommendation to the desired level of consensus, considering its cost benefits.
9

Modeling, analysis, and experimental investigations of grinding processes

Li, Zhichao January 1900 (has links)
Doctor of Philosophy / Department of Industrial & Manufacturing Systems Engineering / Zhijian Pei / Grinding is one of the important operations employed in modern manufacturing industry to remove materials and achieve desired geometry and surface finish. Simultaneous double side grinding (SDSG) and ultrasonic vibration assisted grinding (UVAG) are two typical cost-effective grinding processes which are utilized to grind semiconductor materials and high performance ceramic materials, respectively. The objectives of this research are to investigate several technical issues in modern grinding processes by using theoretical, numerical, and experimental research approaches. Those technical issues are related to SDSG and UVAG, which have been chosen as two typical grinding processes for this research. This thesis reviews the literature on SDSG (covering process applications, modeling of grinding marks, and modeling of wafer shapes) and UVAG (covering process applications, edge chipping, and coolant effects, etc). The theoretical research work of this thesis is conducted by developing mathematical models for grinding marks and wafers shapes in SDSG of silicon wafers. These developed models are then used to study the effects of SDSG parameters on the curvature of the grinding marks, the distance between adjacent grinding marks, and the wafer shapes. The numerical research work of this thesis is done by conducting a three dimensional (3-D) finite element analysis (FEA) of UVAG process. A 3-D FEA model is developed to study the edge chipping commonly observed in UVAG of ceramics. Edge chippings not only compromises geometric accuracy but also possibly causes an increase in machining cost. A solution to reduce the edge chipping is proposed based upon the FEA simulations and validated by pilot experiments. Several experimental studies are conducted to provide new knowledge for the UVAG process. Firstly, a novel coolant delivery system is explored for UVAG machine system. Secondly, UVAG is introduced into machining of fiber-reinforced ceramic matrix composites (CMC). Results of a feasibility study and a designed experimental investigation show that UVAG is a promising process for CMC machining. Finally, an experimental study on cutting forces during UVAG of zirconia/alumina composites is conducted. The feasibility to machine different zirconia/alumina composites using UVAG is also investigated and discussed. The findings in this thesis will provide theoretical and practical guidance for modern grinding processes especially for SDSG and UVAG.
10

Applying ergonomics to dental scalers

Ahern, Stacey January 1900 (has links)
Master of Science / Department of Industrial & Manufacturing Systems Engineering / Malgorzata J. Rys / The current state of the dental industry shows an increasing number of dentists and dental hygienists who are reducing hours and retiring early due to the injuries sustained while working. These injuries, or cumulative trauma disorders, can be reduced by applying ergonomics in dental tool design. The goal of ergonomics is to reduce current injuries but also prevent future ones. In addition, population demographics have shown an increasing trend in female dentists. With a shift from the male dominated field, design for different anthropometric measurements needs to be investigated. In order to pinpoint sources of pain, a survey was designed and distributed to dentists in Kansas, Missouri, and Texas. Even with a small sample size (n=24), results confirmed past studies in the dental industry of pain originating in the neck, shoulder, lower back, and wrist/hand region. The reasons stemmed from the repetitive motions and forces applied during dental procedures. Responses also found that ergonomic principles need to be applied to the handle and grip portion of dental scaler design. Dental scaling is the procedure to remove deposits on teeth, such as plaque and calculus, most commonly performed by dental hygienists. First, the history of dental tools, angulation, tool weight, and materials currently utilized were researched before looking into specific design factors for modification. Currently, the handle grip area on all dental tools range in size, but a 10 mm grip has been proven to be optimal. The optimal tool weight has yet to be determined as 15 grams is the lowest weight to be tested. Most tools are made of stainless steel and resins, which are not compressible. An experiment was designed to test a new dental scaler (A) made of a titanium rod with added compressibility in the precision grip area. The aim was to help reduce pressure on the fingers and hand muscles and increase comfort during scaling. The experiment utilized a Hu-Friedy sickle scaler (B) and a Practicon Montana Jack scaler (C) as controls to show two design spectrums, weight and material. The subjects (n=23) were taught the basics of scaling and required to scale using a typodont. The change in grip strength (Δ GS), pinch strength (Δ PS), and steadiness of the subjects hand were tested. An absolute and relative rating technique was utilized pinpointing that the new dental scaler was preferred with the eigenvector (A=0.8615, B=0.1279, C=0.0106). Statistical analysis confirmed this tool preference while also finding the interaction of gender and tool and Δ GS Tool A versus Tool B for males to be significant.

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