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- Genre: Masters Thesis
- Creators: Arizona State University
- Creators: Chakraborty, Bijeta
- Member of: ASU Electronic Theses and Dissertations
Description
Utilizing the Arizona State University's Performance Based Studies Research Group, and their PIPS program, a roofing materials manufacturing company can evaluate performance of representatives, products and contractors. Service life of the systems can be tracked and customer satisfaction measured it provides an objective viable tool for the consumer to choose a quality product and contractor without the distractions of marketing, promises, or a salesman's hype. Facilities purchasing a new roof system, can benefit from the information gathered as a guide in making sound, value based decisions. Creating a historical, concise and accurate documentation of roofing systems is a benefit to all involved. The procurement process, installation and longevity of the roofing systems can be tracked and graded.
ContributorsGreenfeld, Larry (Author) / Kashiwagi, Dean T. (Thesis advisor) / Sullivan, Kenneth T. (Committee member) / Badger, William W. (Committee member) / Arizona State University (Publisher)
Created2013
Description
Efficiency of components is an ever increasing area of importance to portable applications, where a finite battery means finite operating time. Higher efficiency devices need to be designed that don't compromise on the performance that the consumer has come to expect. Class D amplifiers deliver on the goal of increased efficiency, but at the cost of distortion. Class AB amplifiers have low efficiency, but high linearity. By modulating the supply voltage of a Class AB amplifier to make a Class H amplifier, the efficiency can increase while still maintaining the Class AB level of linearity. A 92dB Power Supply Rejection Ratio (PSRR) Class AB amplifier and a Class H amplifier were designed in a 0.24um process for portable audio applications. Using a multiphase buck converter increased the efficiency of the Class H amplifier while still maintaining a fast response time to respond to audio frequencies. The Class H amplifier had an efficiency above the Class AB amplifier by 5-7% from 5-30mW of output power without affecting the total harmonic distortion (THD) at the design specifications. The Class H amplifier design met all design specifications and showed performance comparable to the designed Class AB amplifier across 1kHz-20kHz and 0.01mW-30mW. The Class H design was able to output 30mW into 16Ohms without any increase in THD. This design shows that Class H amplifiers merit more research into their potential for increasing efficiency of audio amplifiers and that even simple designs can give significant increases in efficiency without compromising linearity.
ContributorsPeterson, Cory (Author) / Bakkaloglu, Bertan (Thesis advisor) / Barnaby, Hugh (Committee member) / Kiaei, Sayfe (Committee member) / Arizona State University (Publisher)
Created2013
Description
The current paradigm to addressing the marginal increases in productivity and quality in the construction industry is to embrace new technologies and new programs designed to increase productivity. While both pursuits are justifiable and worthwhile they overlook a crucial element, the human element. If the individuals and teams operating the new technologies or executing the new programs lack all of the necessary skills the efforts are still doomed for, at best, mediocrity. But over the past two decades researchers and practitioners have been exploring and experimenting with a softer set of skills that are producing hard figures showing real improvements in performance.
ContributorsMischung, Joshua (Author) / Sullivan, Kenneth T. (Thesis advisor) / El Asmar, Mounir (Committee member) / Wiezel, Avi (Committee member) / Arizona State University (Publisher)
Created2014
Description
Class D Amplifiers are widely used in portable systems such as mobile phones to achieve high efficiency. The demands of portable electronics for low power consumption to extend battery life and reduce heat dissipation mandate efficient, high-performance audio amplifiers. The high efficiency of Class D amplifiers (CDAs) makes them particularly attractive for portable applications. The Digital class D amplifier is an interesting solution to increase the efficiency of embedded systems. However, this solution is not good enough in terms of PWM stage linearity and power supply rejection. An efficient control is needed to correct the error sources in order to get a high fidelity sound quality in the whole audio range of frequencies. A fundamental analysis on various error sources due to non idealities in the power stage have been discussed here with key focus on Power supply perturbations driving the Power stage of a Class D Audio Amplifier. Two types of closed loop Digital Class D architecture for PSRR improvement have been proposed and modeled. Double sided uniform sampling modulation has been used. One of the architecture uses feedback around the power stage and the second architecture uses feedback into digital domain. Simulation & experimental results confirm that the closed loop PSRR & PS-IMD improve by around 30-40 dB and 25 dB respectively.
ContributorsChakraborty, Bijeta (Author) / Bakkaloglu, Bertan (Thesis advisor) / Garrity, Douglas (Committee member) / Ozev, Sule (Committee member) / Arizona State University (Publisher)
Created2012
Description
In this thesis, a digital input class D audio amplifier system which has the ability
to reject the power supply noise and nonlinearly of the output stage is presented. The main digital class D feed-forward path is using the fully-digital sigma-delta PWM open loop topology. Feedback loop is used to suppress the power supply noise and harmonic distortions. The design is using global foundry 0.18um technology.
Based on simulation, the power supply rejection at 200Hz is about -49dB with
81dB dynamic range and -70dB THD+N. The full scale output power can reach as high as 27mW and still keep minimum -68dB THD+N. The system efficiency at full scale is about 82%.
to reject the power supply noise and nonlinearly of the output stage is presented. The main digital class D feed-forward path is using the fully-digital sigma-delta PWM open loop topology. Feedback loop is used to suppress the power supply noise and harmonic distortions. The design is using global foundry 0.18um technology.
Based on simulation, the power supply rejection at 200Hz is about -49dB with
81dB dynamic range and -70dB THD+N. The full scale output power can reach as high as 27mW and still keep minimum -68dB THD+N. The system efficiency at full scale is about 82%.
ContributorsBai, Jing (Author) / Bakkaloglu, Bertan (Thesis advisor) / Arizona State University (Publisher)
Created2015
Description
ABSTRACT
As the execution of facilities management becomes ever more sophisticated, specialized skill in managing specific types of buildings has become necessary. The sector of maintaining historic structures and sites readily falls into this type of specialized classification. This paper is a case study review of the unique “best practices” at the Nauvoo Historic Site located in Nauvoo, Illinois. It outlines a facilities management model of common core practices that was developed by the author following an assessment of various similar historic preservation campuses and their responsibilities to accurately display historic culture while observing modern-day facilities management techniques. Although these best practices are of great value in Nauvoo, they are proposed to be valuable to other sites as well because of their effectiveness. As a part of the description of best practices, an overview of the unique history of Nauvoo that generated the modern-day interest in the site will be reviewed. Additionally, the Nauvoo Facilities Management (NFM) organization will be detailed and will focus on the unique challenges associated with historic restored and reconstructed structures. Finally, the paper will also examine the use of specific facilities management techniques, management of large-scale visitor events, livestock supervision, workforce dynamics, finance and capital improvements, managing NFM within the corporate structure of a worldwide religious organization, and the part that NFM plays in community relations.
As the execution of facilities management becomes ever more sophisticated, specialized skill in managing specific types of buildings has become necessary. The sector of maintaining historic structures and sites readily falls into this type of specialized classification. This paper is a case study review of the unique “best practices” at the Nauvoo Historic Site located in Nauvoo, Illinois. It outlines a facilities management model of common core practices that was developed by the author following an assessment of various similar historic preservation campuses and their responsibilities to accurately display historic culture while observing modern-day facilities management techniques. Although these best practices are of great value in Nauvoo, they are proposed to be valuable to other sites as well because of their effectiveness. As a part of the description of best practices, an overview of the unique history of Nauvoo that generated the modern-day interest in the site will be reviewed. Additionally, the Nauvoo Facilities Management (NFM) organization will be detailed and will focus on the unique challenges associated with historic restored and reconstructed structures. Finally, the paper will also examine the use of specific facilities management techniques, management of large-scale visitor events, livestock supervision, workforce dynamics, finance and capital improvements, managing NFM within the corporate structure of a worldwide religious organization, and the part that NFM plays in community relations.
ContributorsCluff, Casey (Author) / Sullivan, Kenneth T. (Thesis advisor) / Smithwick, Jake (Committee member) / Stone, Brian (Committee member) / Arizona State University (Publisher)
Created2017
Description
This thesis presents a literature research analyzing the cost overrun of the construction industry worldwide, exploring documented causes for cost overrun, and documented parties responsible for the inefficiency. The analysis looks at a comparison between the metrics of construction projects in different continents and regions. Multiple publication databases were used to look into over 300 papers. It is shown that although construction demands are increasing, cost overrun on these projects is not decreasing at the same rate around the world. This thesis also presents a possible solution to improve cost overrun in the construction industry, through the use of the Best Value Performance Information Procurement System (BV PIPS). This is a system that has been utilized in various countries around the world, and has documented evidence that it may be able to alleviate the overrun occurring in the construction industry.
ContributorsGoyal, Abhinav (Author) / Kashiwagi, Jacob (Thesis advisor) / Kashiwagi, Dean (Committee member) / Chong, Oswald (Committee member) / Arizona State University (Publisher)
Created2017
Description
The higher education sector is always changing and seeks for robust methodologies to make education more effective and produce higher quality products which are the future professionals. While each student has different preference in learning, numerous forms of instructional strategies are adopted to engage students in varied ways. Existing literature has studied the impacts of various teaching strategies on students’ performance. Previous studies did not figure out if personal characteristics such as honestly, emotionality, etc. have any impacts on the students’ academic performance. This master thesis uses the detailed information gathered through surveying construction students and analyses such data to determine the relationship between various personal factors and understand if there is any relation between students’ academic performance and personal characteristics. This work has used HEXACO factor scales and Emotional Intelligence (EI) as a basis of its analysis. Results of this analysis indicated that there is no significant correlation between students’ academic performance and HEXACO and EI criteria. Although the analysis process tried to provide the most accurate and robust results, but findings could potentially be affected by a number of factors such as excluding some survey responses from data analysis due to confusing responses or being outlier.
ContributorsDadvar, Atefeh (Author) / Sullivan, Kenneth (Thesis advisor) / Smithwick, Jake (Committee member) / Lines, Brian (Committee member) / Arizona State University (Publisher)
Created2017
Description
During the rapid growth of infrastructure projects globally, countries pay high environmental and social costs as a result of the impacts caused from utilizing the traditional open-cut utility installation method that still widely being used in Egypt. For that, it was essential to have alternatives to reduce these environmental impacts and social costs; however, there are some obstacles that prevent the implementation and the realization of these alternatives.This research is conducted mainly to evaluate the environmental impacts of open-cut excavation vs. trenchless technology in Egypt, through two main methodologies. Firstly, a field survey that aims to measure knowledge of people working in the Egyptian construction industry of trenchless technology, and the harms caused from keeping utilizing open-cut for installing all kinds of underground utilities. In addition to investigating the reasons behind not relying on trenchless technology as a safe alternative for open-cut in Egypt.
Furthermore, in order to compare the greenhouse gases emissions resulted from both open-cut vs trenchless technology, a real case study is applied quantifying the amounts of the resulted greenhouse gases from each method. The results show that greenhouse gases emissions generated from open-cut were extremely higher than that of horizontal directional drilling as a trenchless installation method.
ContributorsKhedr, Ahmed Mossad Saeed Hafez (Author) / Ariaratnam, Samuel (Thesis advisor) / El Asmar, Mounir (Committee member) / Chong, Oswald (Committee member) / Arizona State University (Publisher)
Created2023
Description
Many public agencies and/or private owners have no standards that help them to select the most suitable delivery method for their capital projects; hence, in some cases, this results in selecting the inappropriate project delivery method. This adversely impacts the project performance and leads to many negative consequences; starting with schedule growth, cost overrun, and may end up in an epic failure of the project. This research mainly focuses on developing a guideline to help owners make the decision on selecting the most appropriate delivery method for their capital projects. This research goes through three stages: Stage 1 - An extensive literature review of past research is conducted to conclude the selection factors considered in the decision-making process and the decision analysis technique and the project delivery methods; Stage 2 - This stage includes building up the selection model and setting out its guidelines; Stage 3 - This is the final stage of the research thread and includes the validation of the selection model through applying this model on some case study projects by industry practitioners, then evaluating the final results. The owner’s guideline for project delivery method selection, developed within this research, is designed to help owners increase the project success likelihood by selecting the suitable project delivery methods during the pre-construction phase (planning phase of the project life cycle).
ContributorsSallam, Omar Mohamed (Author) / Sullivan, Kenneth (Thesis advisor) / Hurtado, Kristen (Committee member) / Kutz, Barry (Committee member) / Arizona State University (Publisher)
Created2021