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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.
71

A Tool Wear Comparative Study in Turning Versus Computer Simulation in 1018 Steel

Miner, Woodrow D. 17 March 2005 (has links) (PDF)
The material removal process uses cutting tools in order to produce the desired shape of the workpiece. Tool wear has been a problem for cutting tools, since cutting tools wear and break. Research has been accomplished in the tool wear field for tool life and more recently tool wear. The computer generation has created a method to simulate the material removal process. These computer simulations model the cutting tool reaction with the workpiece. Many of the simulation models use finite element analysis to calculate the reaction of the cutting tool. Different finite element models are being used throughout the world for research. This thesis used an updated Lagrangian model in conjunction with Archard's law to predict the wear of the cutting tool. This research used experimental data to correlate with simulation data to see whether or not Archard's law was a good approximation for tool wear. The research used different side rake angles and cutting surface speed to test the simulation. Shear angle, contact length, cutting ratio, and force are used to provide output values to compare the experimental and computer simulation data. The comparative results showed good trends between the experimental and computer simulation data in every comparison. The results also showed a good approximation for the force and contact length values. Archard's law can be used to model wear on cutting tools with further research.
72

Correlating Factors Between Student Participation and Student Learning Via a Service Learning Project in Secondary Education: A Case Study

Jensen, Shawn V. 18 January 2006 (has links) (PDF)
In this study a service-learning project was conducted with secondary students in a construction technology based course. Three research questions were considered; (1) does service learning projects help to engage student participation, (2) can students learn the course curriculum while participating in a service learning project, and (3) is there a correlation between student participation and student learning as it pertains to service learning projects? The data was collected through surveys, observations, interviews, and evaluations. The researcher concluded the following from the study; 92% of the students were actively participating in the two week service project, 76% of the students learned the curriculum for the unit in a satisfactory manner, and it was determined that there is a significant correlation between students participation or commitment to the service learning project with how well the students learned the curriculum for that unit.
73

Automated Manipulation for the Lotus Filament Winding Process

Anderson, Jeffrey V. 17 March 2006 (has links) (PDF)
The filament-winding process produces quality consistent composite parts for many industries. Filament winding allows for consistent quality parts by automating the winding process. A recent development of filament winding is the Lotus process. The Lotus process reverses conventional filament winding by leaving the mandrel stationary and winding composite fiber around the mandrel. The automated Lotus filament-winding machine is controlled by four-axis control manipulating the Lotus ring around a fixed mandrel. This allows Lotus filament winding to wind parts that do not have a linear axis. Lotus filament winding is in its early stages of development. As a second step in the development of Lotus filament winding a method of automatic part-to-machine manipulation has been developed. Parts wound on the new automatic-manipulated Lotus machine have comparable quality and appearance to those made by conventional winding.
74

The Role of the Architect: Changes of the Past, Practices of the Present, and Indications of the Future

Jones, Chad B. 19 March 2006 (has links) (PDF)
For centuries the architect was the master builder; the one who was responsible for both the design and the construction of a project with sufficient construction expertise to oversee the project from inception to completion. Eventually, complexity of projects required a higher level of specialization leading to the separation of the designer and the builder. Since that separation, the role of the designer, or architect, has continued to shift and evolve. In recent history, the architect has been the one selected by a building owner, at the inception of the project, as the professional who is able to assist and represent the owner throughout the duration of the project. Today however, the role of the architect is once again shifting and leading the architect in a different direction. Building owners are beginning to approach the builder through a design-build or construction manager delivery method first and relying upon them for the overall project and construction expertise instead of the architect. The architect will continue to carry the responsibility of creating the building's design and producing the construction documents. It is very unlikely that this role will change. Any of its other construction related roles, however, are being assumed by the build team. If the architect remains on its current path, it will continue to become more specialized with design and production and carry less responsibility. While the exact role of the architect of today is unclear and heading in a negative direction, the entire construction process continues to evolve and provide new opportunities. The successful architect to come is going to be the one who looks at ways to reclaim its lost responsibilities, explore new alternative services, and promote a higher level of collaboration with the build team.
75

Payback Information: It's Effect on Home Buyers Regarding Energy Efficiency

Sparti, Steven E. 20 June 2006 (has links) (PDF)
This study was conducted to find out how payback analysis would affect consumer decision making with regards to home energy efficient upgrade packages. Three different home plans were obtained from a local builder and seven different energy efficient packages were created. Using Hot2000 the heating and cooling loads were calculated for each building, with each energy efficient package, in each of the four major cardinal directions. The averages were taken and the payback information was calculated. The payback information included the increased cost of the package, the increase in the mortgage payment, the annual savings from heating and cooling bills, the monthly savings, the positive or negative monthly cash flow, the amount of time and interest saved if the monthly savings were added to the mortgage principle, the number of years required to pay back the original investment, the rate of return and the increased home value. A survey was taken to see how the subjects would react to viewing the payback information. The subjects were individuals looking to buy a home in the next 12 months somewhere along the Wasatch Front area in Utah. Depending on the size of the home the subjects were looking for, the subjects were shown the different packages with their accompanying cost increase and how that would affect the subjects monthly mortgage payment. The subjects then chose the package they would want for their home, based on their knowledge of construction materials, the additional cost, and how it would affect their mortgage. They were then shown the payback information for the home that was chosen and asked if they would change their mind concerning the previous decision. They were then asked what parts of the payback information they found to be most useful. This study shows that payback information is indeed useful and would help builders to attract new customers, increase profits, and provide customers with powerful information that will empower them to make better decisions about home energy efficiency.
76

Contractor Variability in Construction of Cement Treated Base Layers

Rogers, Maile Anne 19 July 2006 (has links) (PDF)
The primary purposes of this research were to identify construction factors most correlated to specific mechanical properties of cement-treated base (CTB) layers and to determine which construction factors exhibit comparatively high variability within individual construction sections of the two pavement reconstruction projects included in this study. In addition, differences between construction sections tested in this research were evaluated. The research focused on the construction of CTB layers in two pavement reconstruction projects in northern Utah, one along Interstate 84 (I-84) near Morgan and one along U.S. Highway 91 (US-91) near Richmond. The significant predictor variables associated with California bearing ratio (CBR), Clegg impact value (CIV), 7-day unconfined compressive strength (UCS), and 28-day UCS at the I-84 sites include reclaimed asphalt pavement (RAP) content; cement content; amounts of aggregate particles finer than the No. 8, No. 50, and No. 200 sieves; 7-day moisture content, and 28-day moisture content. The significant predictors of the same response variables on US-91 were in-situ moisture content, cement content, amount of aggregate particles finer than the No. 50 sieve, time between mixing and compaction in the field, dry density in the field, 7-day dry density, 7-day moisture content, 28-day dry density, and 28-day moisture content. The factors that were found to be the most variable on both I-84 and US-91 were CBR, cement content, time between mixing and compaction in the field, and time between mixing and compaction for each of the manually compacted specimens. On I-84, 16 of 27 factors were found to be significantly different between the sites, while 17 of 26 factors were found to be significantly different between the sites on US-91. The results of this research suggest that tighter specifications are warranted with respect to RAP content, cement content, and time between mixing and compaction. Concerning full depth recycling (FDR) projects, milling plans should be utilized to achieve improved uniformity in RAP content, and inspection protocols for encouraging improved control of cement content should be implemented during construction to ensure high-quality work. Compaction should be performed as soon as possible after mixing to minimize the adverse effects of cement hydration on the ability to achieve maximum dry density in the field.
77

Comparing Time and Accuracy of Building Information Modeling to On-Screen Takeoff for a Quantity Takeoff of a Conceptual Estimate

Alder, Morgan A. 19 July 2006 (has links) (PDF)
Estimating is a critical aspect of every construction project. The most tedious component of an estimate is the quantity takeoff. Different tools are available to improve an estimator's productivity for a quantity takeoff. Faster quantity takeoffs enable estimator to bid more jobs. This study analyzed the time and accuracy of performing quantity takeoffs when using building information modeling (BIM) through a comparison study using Revit (BIM software) and On-Center's OST. In preparation for the study the researcher conducted a pilot study. Participants of the study were asked to perform a quantity takeoff using both Revit and OST. Their resulting data was then, analyzed comparing both the time and accuracy of each item taken off. The subjects' perspectives on the two different methods of performing takeoff are also included in the findings of this study. This study focused on a conceptual estimate takeoff for a small commercial building. The results of the study showed that, on average, those using BIM were able to perform the overall takeoff faster than those using OST while still maintaining equivalent accuracy. This study includes methods to improve productivity for quantity takeoff through an analysis of the takeoffs of counts, areas, and lengths. Findings of this study include methods, techniques, and cautions for performing a quantity takeoff using BIM.
78

Integrating Value Stream Mapping and Simulation

Scullin, Michelle E. 07 July 2005 (has links) (PDF)
An important principle in Lean manufacturing, value stream mapping (VSM) can be helpful in understanding how process flow and information flow affect each other. A VSM is a static picture of a process that allows the user to see where value is added into the value stream. Simulation is used to evaluate the behavioral issues of processes. In a manufacturing realm this means simulation shows how each operation affects other operations so determinations can be made about where bottlenecks or other problems exist in the process. Theoretically, the integration of VSM and Simulation can aide in process improvement by showing both the static and behavioral characteristics of a process. Determining the feasibility of such an integration is the basis for this thesis. Using research performed by Jack McClellan at BullFrog Spa, a comparative study was conducted by two test groups. One used the traditional simulation approach and the other the integrated simulation approach. The test groups were formed from nine students taking the Manufacturing Systems course fall semester 2004. The traditional simulation approach used the ProModel simulation software to perform a test using a paper form of a VSM. The integrated simulation approach used Process Simulator simulation software, which created a simulation from a VSM created in Microsoft Visio. After completion of the tests, the students filled out surveys comparing their results with McClellan's results for verification of their simulations. The results from the study indicated that the students were able to create a working simulation using both approaches and there was no significant difference between times that it took to create the simulations. It was also discovered that a VSM helps increase understanding of a process, but cannot be the sole source of information to create a simulation. More behavioral information about the process is needed.
79

Improved Signal Integrity in IEEE 1149.1 Boundary Scan Designs

Taboada, Efren De Jesus Rangel 04 November 2004 (has links) (PDF)
This work is an analysis of solutions to problems derived from inherent timing and signal integrity issues in the use and application of the IEEE 1149.1 Standard at the board level in conjunction with its test system. Setup or hold times violations may occur in a boundary scan chain using IEEE 1149.1 compliant devices. A practical study of the TDI-TDO scan data path has been conducted to show where problems may arise in relationship to a particular board topology and test system. This work points to differences between passing and failing scan path tests for problem characterization. Serial data flow is then analyzed and suitability is discussed. Within certain conditions, a solution is proposed. This work has been shown to work on the test system. Recommendations are made based on this experimental approach.
80

Assessing Construction Management Higher Education Strategies: Increased Demand, Limited Resources, and Over-Enrollment

Wynn, Kristen Lea 15 August 2005 (has links) (PDF)
The purpose of this research was to see how Baccalaureate Construction Management Programs accredited by the American Council for Construction Education (ACCE) were managing increased enrollments within their programs. The review of literature identified related topics, comparable studies, and relevant issues surrounding over-enrollment. Forty-nine of the 53 accredited ACCE programs responded to the survey instrument. Over two-thirds of the respondents stated that they were either approaching, or were at the limits of enrollment capacities. Most of the respondents listed limited enrollment, the use of adjunct faculty, and funding from industry as leading strategies for managing or obtaining resources. Because CM programs will not be willing to sacrifice quality, more and more CM programs will implement limited enrollment controls. The demand for Construction Management graduates will continue to increase. As more CM programs initiate enrollment controls, it will become increasingly difficult for the construction industry to fill entry level positions with college graduates. Limited enrollment will create a deficit of qualified CM graduates needed by the industry. Because CM programs are having difficulties acquiring resources through the university, it may be necessary to acquire additional resources through industry. According to a number of program directors, one of the best ways to raise funds within industry is through the use of Industry Advisory Boards. Industry Advisory Boards can help in another critical aspect to the future expansion of CM programs; improve university perceptions about Construction Management education

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