Engineering Commons^™

Search-Based System Architecture Development Using A Holistic Modeling Approach, Renzhong Wang

Doctoral Dissertations

"This dissertation presents an innovative approach to system architecting where search algorithms are used to explore design trade space for good architecture alternatives. Such an approach is achieved by integrating certain model construction, alternative generation, simulation, and assessment processes into a coherent and automated framework. This framework is facilitated by a holistic modeling approach that combines the capabilities of Object Process Methodology (OPM), Colored Petri Net (CPN), and feature model. The resultant holistic model can not only capture the structural, behavioral, and dynamic aspects of a system, allowing simulation and strong analysis methods to be applied, it can also specify …

Decreasing Time To Market For A Medical Device: New Methods For The Product Development Process, Kelly Marie Davis

Doctoral Dissertations

"Through an example, led at a leading medical device company, this dissertation will demonstrate that by applying certain lean principals and tools to the development of a medical device, shortened development times can be obtained. The two papers presented in the dissertation will fill a gap in current literature. Literature presents lean techniques and applications used in many different industries. But, due to the uniqueness of the medical device industry, these general techniques are not ideal. New methods will be used and validated at a medical device company, Covidien. Instead of trying to implement many general lean principals to their …

Dynamic Decision Making Under Uncertainty In Renewable Energy Portfolio Management And Inventory Management, Jianjun Deng

Doctoral Dissertations

"It is challenging and important for a firm to make effective decisions under uncertainties, such as random fluctuations of products prices or demands, etc. This dissertation formulates mathematic models to help decision makers in energy and retail industries make optimal timing and optimal operational decisions when facing uncertain electricity prices and demands. As for energy portfolio management, the optimal entry and dispatch strategies are investigated for an electricity generating firm to introduce a renewable power plant as an alternative method for generating electricity, with or without construction delay. In addition, the abandonment strategies of considering shutting down one of the …

Use Of Exploratory Data-Mining Techniques To Analyze Associations Between Bone-Mineral Density And Relevant Clinical Parameters Of Gaucher Disease, Tingting Fu

Browse all Theses and Dissertations

Gaucher disease (GD) is a monogenic disorder with autosomal recessive inheritance, which results from an acid lysosomal hydrolase, the beta-glucocerebrosidase deficiency. Clinical manifestations of the disease include anemia, thrombocytopenia, hepatosplenomegaly, and skeletal complications. Enzyme replacement therapy (ERT) has been used to treat type 1 GD for more than a decade, and many patients have shown remarkable clinical responses to the treatment, with normalization of blood counts, reduction in liver and spleen size, and improvement in bone symptoms. Many researchers have tried to study the effectiveness of ERT, but previous research has been mainly based on some predetermined hypotheses and traditional …

The Design And Evaluation Of Wireless Sensor Networks For Applications In Industrial Locations, Hameed Madwar

Dissertations and Theses @ UNI

In manufacturing industries, there exist many applications where Wireless Sensor Networks (WSN's) are integrated to provide wireless solution for the automated manufacturing processes. It is well known that industrial environments characterized by extreme conditions such as high temperature, pressure, and electromagnetic (EM) interference that can affect the performance of the WSN's. The key solution to overcome this performance issue is by monitoring the received Signal Strength Index (RSSI) at the received sensor of the WSN device and track frame error rate of wireless packets.

ZigBee is a wireless sensor network (WSN) standard designed for specific needs of the remote monitoring …

Using Metarules To Integrate Knowledge In Knowledge Based Systems. An Application In The Woodworking Industry, Alvaro Villavicencio

Dissertations and Theses @ UNI

The current study addresses the integration of knowledge obtained from Data Mining structures and models into existing Knowledge Based solutions. It presents a technique adapted from commonKADS and spiral methodology to develop an initial knowledge solution using a traditional approach for requirement analysis, knowledge acquisition, and implementation. After an initial prototype is created and verified, the solution is enhanced incorporating new knowledge obtained from Online Analytical Processing, specifically from Data Mining models and structures using meta rules. Every meta rule is also verified prior to being included in the selection and translation of rules into the Expert System notation. Once …

Coolant Fluid In A Turning Operation: Soybean Coolant Fluid In Different Concentrations Versus Petroleum Coolant Fluid, Mary Esther Eckman

Dissertations and Theses @ UNI

The manufacturing sector today's market felt the need to reduce costs along with the ability to be more "green."

Traditionally petroleum based fluids are used in the manufacturing industry. However they are environmentally more harmful as well as cause significant hazards to the operator. This thesis will provide a case study for this sector to become more environmentally friendly with the use of a soybean based cutting fluid. To prove the point a number of tests were performed turning 4140 steel on a CNC turning center. A number of tests were conducted to provide a comparative study of dry, petroleum …

An Investigation On In-Process Spc Sampling Frequency For Shaft Bearing Turning Process, Jiaxu Chu

Dissertations and Theses @ UNI

The machining processes have the uniqueness of discrete production and flexible scheduling as cellular manufacturing design. To ensure the quality of machining products, control charts for Statistical Process Control (SPC) has been implemented in the company to monitor the machining process. Sampling is an essential part of data collection for SPC control charts and sampling should be done for machining processes becomes an issue in the company.

This study focused on the investigation of SPC sampling frequencies for shaft bearing turning process using the technique of Average Production Length (APL). The purpose of the study was to identify the SPC …

The Integration Of Wind Energy In The Electrical Grid During The Contingencies, Islam Ali

Dissertations and Theses @ UNI

As wind energy expansion develops, there are also many problems and challenges to connect the wind farms to the grid. There are many different interactions during the connection like the voltage flicker, harmonics, transient, short circuit current, frequency, and safety protection. Those problems may affect the performance of the grid and may cause serious problems. This study investigates the grid-connection problems for the wind turbines and offers appropriate solutions. This study provides a simulation for the power system during the faults. The electrical grid in the simulation contains generators and wind turbines which are connected to the grid. It also …

Modeling And Analysis Of Grid-Connected Solar-Wind Hybrid Power System, Sultan Altamimi

Dissertations and Theses @ UNI

Renewable energies are considered to be a significant part of the energy mix to assist the existing electricity demand and the future of electrical generation. Electrical power simulation software is increasingly being used to answer and determine the source of potential problems in the actual power system. To have a better understanding of an electrical power system, it is essential to validate all the components through simulation within an environment that allows accurate modeling of all power system components. This research presents modeling and analysis of an actual grid-connected solar-wind hybrid system at University of Northern Iowa campus in Cedar …

Robotic Manufacturing Cell: An Analysis Of Variables Affecting Performance, Elvis Alicic

Dissertations and Theses @ UNI

Analyzing the performance of manufacturing cells is a well established concept. The justification for conducting thorough analyses of manufacturing cells comes from the known advantages it can provide, including performance improvement and production planning improvement, both current and future. This study focuses on assessing the variables affecting performance of a robotic manufacturing cell through the measure of throughput. Initially, simulation modeling is utilized to model an existing robotic cell and compare the output to actual production output from the same cell. Additionally, general regression modeling is employed to analyze the following variables and their effect on throughput: machine downtime, off-plan …

Ergonomics Evaluation Of Task Demands Among Kitchen Staff, Jaqueline Pereira Da Silva

Dissertations and Theses @ UNI

The purpose of this study was to evaluate the workplace demands faced by a group of kitchen staff at six dining centers and to survey musculoskeletal complaints among this sample of workers. The dining centers were located in six different public elementary and middle schools in a city in the south of Brazil. This research was developed following qualitative research design, and the researcher made use of the “Activity Oriented Ergonomics (AOE) methodology.

The AOE focuses on the work analysis that evaluates real work situations that allows a reassessment of work demands. In this case the chosen methodology was a …

Decision Rule Induction For Service Sector Using Data Mining- A Rough Set Theory Approach, Zhonghua Hu

Open Access Theses & Dissertations

Nowadays, data mining is more widely used than ever before; not only by the academic area, but also in the industry and business area. Apart from execution of business processes, the creation of knowledge base and its utilization for the benefit of the organization is becoming a strategy tool to compete. Despite of having ever growing data bases, the problem is that the finance company fails to fully capitalize the true benefits which can be gained from this great wealth of information. The data mining technology instead of classic statistical analysis is developed to help the people to discover the …