Engineering Commons^™

Machining Stability Of Wire Edm Of Titanium, Farnaz Nourbakhsh

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

This work presents an experimental investigation of wire electro-discharge machining (WEDM) of titanium alloy. The outstanding characteristics of titanium alloys such as their compatibility and noticeable physical, mechanical and biological performances has led to increased application of them in various industries especially in biomedical industries over the last 50 years. However, due to low thermal conductivity of titanium and its alloys and their reactivity with cobalt in most tool materials, there are some difficulties in machining titanium and its alloys by conventional machining. On the other hand, unconventional machining processes especially Wire Electrical Discharge Machining (WEDM) are more appropriate techniques …

Three-Dimensional Indoor Rfid Localization System, Jiaqing Wu

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

Radio Frequency Identification (RFID) is an information exchange technology based on radio waves communication. It is also a possible solution to indoor localization. Due to multipath propagation and anisotropic interference in the indoor environment, theoretical propagation models are generally not sufficient for RFID-based localization. In fact, the radio frequency (RF) signal distribution may not even be monotonic and this makes range-based localization algorithms less accurate. On the other hand, range free localization algorithms, such as k Nearest-Neighbor (kNN), require reference tags to be spread throughout the whole three-dimensional (3D) space which is simply not practical. In this work, a hybrid …

Healthcare Quality: Waiting Room Issues, Vineeth R. Yeddula

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

In today’s hyper-competitive market, customers are faced with many different options when deciding on a specific healthcare provider. Due to the varying options, quality and service stand out as two essential elements that influence the selection process. If the quality is not met, the healthcare organizations have to face several issues such as customer retention, value, safety, litigation, and reputation. Patient satisfaction has emerged as an increasingly important parameter in the assessment of health care quality. Waiting time is considered to be an important determinant of patient satisfaction. As patients experience a greater squeeze on their time, short waits seem …

A Model For Optimizing The Allocation Of Ethanol Production In The U.S., Anali Huggins

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

In the last five years, fuel prices have fluctuated from 2.86$/gallon to 3.87$/gallon which represents an increase of 35%. This situation has collocated the ethanol manufacturing in an advantageous situation. However, a major problem that is faced by the ethanol producers is the high cost of transportation. The objective of this thesis study is to determine the optimal allocation of ethanol production in the U.S. in 2009 that minimizes the transportation cost. This thesis is based on the application of a linear programing model. The thesis is focused on two questions. The first is the optimal allocation of ethanol between …

Simulation Of Tax Revenues From Individuals Receiving Advanced College Degrees, Dejing Kong

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

State governments always want graduates who received higher education in universities and colleges to stimulate the economic growth of the state. Many state universities want to contribute more to the state’s economy as well, and state universities frequently have relevant economic development activities and offices. The state universities normally receive annual budgeted financial support and occasional special funding from the state government while the state expects contributions to the economic growth and an educated citizen in return. In this research, the economic impact of a graduate degree funded by the state government was considered in the state of Nebraska.

Simulation …

An Investigation Of Medical Device Design And Physical Ergonomics In Healthcare, Adam E. De Laveaga

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

Human factors and process engineering are becoming a prominent area of research and application for industrial engineering principles as healthcare providers seek to improve patient safety, quality the optimization of resources. Human factors engineering and ergonomics play a crucial role in the pursuit of operational excellence and patient safety in healthcare. These disciplines contain the tools required to develop instrumentation, technology and training that can improve the usability of medical technology and the quality of care that patients receive. Designing tasks, tools and processes for optimal human use can enhance performance, reduce errors and improve safety. This thesis encompasses three …

Experimental Investigation Of Hard And Brittle Materials Machining Using Micro Rotary Ultrasonic Machining, Amey V. Patwardhan

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

The demand for miniaturized device and components is rapidly increasing in fields of aerospace, energy, optics, electronics and communication, automation and medical. Rotary Ultrasonic Machining (RUM) is capable of machining hard and brittle materials such as advanced ceramics, glass and silicon used in many industries. Rotary Ultrasonic Machining (RUM) is a hybrid machining process in which material is removed by conventional grinding and ultrasonic machining. Micro RUM is a downscaled version of a macro RUM and is similar to micro Ultrasonic Machining (micro USM), where the vibration takes place in work piece instead of tool.

The goal of this thesis …

Quantity And Capacity Expansion Decisions For Ethanol In Nebraska And A Medium Sized Plant, Mahsa Khoshnoud

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

Corn-based ethanol is the leader of sustainable sources of energy in the United States due to the abundance of corn and the popularity of ethanol-gasoline mixes. Over the past decade, ethanol production has risen from 1.5 million gallons in 1999 to 13 million gallons in 2011. This increase in production requires expansion of ethanol plants. Since Nebraska is the second highest producer of ethanol, we focus our research on the expansion of ethanol plants in Nebraska.

The aim of this study is to develop an optimization model for capital investments in ethanol in Nebraska and a medium sized ethanol plant …

Economic Impact On Annual Profit Of A Retail Inventory Management System When Using Rfid And Considering Discrepancy Ratio, Inaccuracy Ratio, Backorders, And Federal Income Tax, Liyuan Zhang

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

Radio Frequency Identification (RFID) emerged as an important technology with the ability to improve the efficiency and accuracy of object tracking. It has brought cost savings and added value to a wide variety of fields. Retail inventory management system is one of the beneficial fields. In order to better satisfy customers and to improve profit, retailers demand high accuracy in inventory management to service customers without redundant on-hand inventories. The RFID technology, which provides more accurate tracking, can improve retailers’ profit.

Two accuracy factors were proposed to determine the difference in the profit of a retailer inventory management system caused …

Development And Validation Of A Model For Granular Material Volume Measurements, Pourya Fasounaki

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

Keeping inventory record of packed grains in silos poses challenges since the bulk material’s different segments do not discharge uniformly, leading to formation of random peaks and valleys on the surface. To facilitate obtaining accurate volume measurement of the grains by taking into account this non-linear behavior on the surface, laser or plumb-bob level-sensing devices are employed at different part of the surface to probe the level of material under those regions.

The main goals of this research is to study the behavior of granular material in silo while discharging downward and by doing so, differentiate certain flow patterns formed …

An Energy Cost Optimization Method For A Large Scale Hybrid Central Cooling Plant With Multiple Energy Sources Under A Complex Electricity Cost Structure, Yin Guo

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

The cooling energy cost could be a significant portion of the total energy cost for a large organization or building complex during summer. A hybrid system or thermal energy storage system is usually applied to reduce the energy cost. However, without proper integration and operation, the advantage of using such systems could be limited.

This study presents a general energy cost optimization methodology and mathematical model for a hybrid cooling system under a complex electricity cost structure. The model considers the efficiency of the hybrid cooling system and multiple energy sources. The energy cost evaluation reflects a complex cost structure …

System Selection Based On Controlled Risk, Lina Wang

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

The studies of using computer simulation to address stochastic systems selection problem prevail currently. Ranking and selection procedures are statistical procedures that can be used in the field of computer simulation to select the best system or the subset that includes the best system based on a performance metric of the interest with a guaranteed correct selection. The best system is defined in the majority of selection problems as a system with the largest (or smallest) mean value. However, mean is only a measure of the average behavior. Risk, which influences the stability of a system to a large extend, …

Study Of Grinding Burn Using Design Of Experiments Approach And Advanced Kaizen Methodology, Kiruthika Devi Sundarrajan

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

Grinding burn has been one of the re-occurring issues at a leading automotive manufacturer. Historically when grinding burn occurred, trial and error was used to delicately find a set up process settings that provided good-enough-to-get-by results, but not optimal. Some changes include changing the coolant manifold to improve the coolant flow and rate, changing the grinding wheel, changing the type of coolant. The experiments have proved to introduce some improvements, however the occurrence of grinding burns have not been reduced or quantified and the cause of the grinding burn has not been identified or quantified. Grinding is a complex phenomenon …