No description available.

No description available.

No description available.

No description available.

No description available.

A methodology for the design of operational control aspects of an Automatic Guided Vehicle (AGV) based material handling system is presented. The methodology, which is composed of an integrated model of an AGV based system, was implemented using simulation techniques. The model views a manufacturing function as consisting of machining, queueing, and moving of parts in a shop and that these components of manufacturing must be integrated and coordinated if the production objectives of an enterprise are to be realized. A machining center is modeled as a physical region of a plant and it consists of machines for part processing and capacitated queues in which inbound and outbound parts reside, queueing for machining or handling resources. Automatic guided vehicles provide the transport mechanism required to interface the machining centers. A network approach is employed to represent the layout of the facility, including the location of departments, input and output queues in each department, and the layout of the guidance system on which the AGVs operate. The network approach, along with the coordinate system are employed for modeling the actual translation of vehicles and parts through the shop. The travel time of vehicles and parts between points depends on vehicle speed and the prevailing traffic condition along the path of travel. Several shop control strategies in the application of AGVs have been modeled, implemented, and their effects on shop performance demonstrated. Among these factors are vehicle dispatching, vehicle routing, unit load size selection, job sequencing, shop loading, queue constraints, and capacity constraints due to vehicles and machines. A job in the shop is considered to consist of one or more parts grouped in portable unit load sizes. Therefore, it is unit loads rather than jobs that make the flow transitions. The results of the simulation experiments conducted indicated vital control elements in the design of AGV systems. Through a series of output statistics on system performance, the model provides an easy to use tool to analyze, evaluate, and design of AGV based manufacturing system. / Ph. D.

Stem profile models which allow for both taper and form changes (Gray 1956) were constructed and evaluated. Gray defined form to be the basic shape of the tree, e.g. cone or parabolid, and taper to be the rate of narrowing in diameter given a tree form. Ormerod's stem profile model was selected as the basic model since its parameters were readily interpretable in terms of Gray's taper and form definitions. Two stage modeling procedures were used to relate individual tree taper and form parameters to tree and stand characteristics. Two second-stage parameter estimation alternatives were evaluated. Parameter estimates for both techniques, ordinary least squares and random function analysis, were similar. Characteristics used to predict stem form were total tree height, crown ratio, height to the live crown, site index, and tree age. The taper parameter was related to diameter at breast height, crown ratio and site index. Error evaluations suggest that substantial gains in predicting stem diameters were not made using the variable taper and form stem profile models. Two methods were proposed for modeling whole stem inside-bark diameter or cross-sectional area increment. Whole stem increment models were derived from several stem profile models and Presseler's hypothesis on the vertical distribution of cross-sectional area growth. Stem profile models evaluated for constructing compatible increment models were Kozak and others (1969), Ormerod (1973), Goulding and Murray (1976), Max and Burkhart (1976), Cao and others (1980), and Amidon (1984). The increment model based on Presseler's hypothesis was derived as a generalization of the work of Mitchell (1975). Evaluations, with limited increment data, consistently showed that the models based on Presseler's hypothesis predict inside-bark diameter increment with less error than do the profile model compatible increment models. This may be due to the lack of crown information currently used in stem profile models. / Ph. D.

Recent interest in passive solar design has led to numerous analytic methods for including energy concerns in design decisions. These methods characteristically address specific, existing problems or classes of problems. In contrast, this project investigated the incorporation of passive solar issues in design methodology by addressing fundamental concepts of general problem solving. A methodological structure which provides flexible modeling and simulation capability was constructed through the use of various notations -- english, math and Iverson notation (APL). English and math were used in the text of the thesis to communicate theory to the reader. Two APL workspaces, "THERM" and "THERM2," were created to communicate with a computer; and hence, enable the application of the methodological structure to real, complex problems. / M. Arch.

This work presents an investigation of a piezoelectric sensor based energy harvesting system, which collects energy from the surrounding environment. Increasing costs and scarcity of fossil fuels is a great concern today for supplying power to electronic devices. Furthermore, generating electricity by ordinary methods is a complicated process. Disposal of chemical batteries and cables is polluting the nature every day. Due to these reasons, research on energy harvesting from renewable resources has become mandatory in order to achieve improved methods and strategies of generating and storing electricity. Many low power devices being used in everyday life can be powered by harvesting energy from natural energy resources. Power overhead and power energy efficiency is of prime concern in electronic circuits. In this work, an energy harvester is modeled and simulated in Simscape™ for the functional analysis and comparison of achieved outcomes with previous work. Results demonstrate that the harvester produces power in the 0 μW to 100 μW range, which is an adequate amount to provide supply to low power devices. Power efficiency calculations also demonstrate that the implemented harvester is capable of generating and storing power for low power pervasive applications.

Due to increasing diversity and shifting demographics nationally, many professional organizations have called upon nursing education to prepare future generations of nurses to provide culturally appropriate care to diverse patient populations. It is crucial to use evidence-based pedagogical strategies to teach nursing students to tailor care to meet the diverse needs of patients. Simulation has been widely used in nursing education as an effective pedagogical strategy. A study was undertaken to explore the differences between using a high-fidelity manikin versus a standardized patient in simulation on cultural humility and cultural self-efficacy in second- and fourth-year baccalaureate nursing students. Second-year (n = 39) and fourth-year (n = 58) students were equally distributed into two groups. The intervention group participated in a simulation using a standardized patient and the comparison group used a high-fidelity manikin. Mean scores on the Cultural Humility Scale (Foronda, 2020) were used to measure cultural humility, and mean scores on the Cultural Self-Efficacy Scale (Bernal & Froman, 1987) were used to measure cultural self-efficacy. A researcher-developed 5-item demographic survey was used to collect demographic information from participants. The simulation sessions were conducted over 7 weeks from the end of February to mid-April in the spring semester of 2024. Students participated in the simulation session as a clinical group of 4-9 students on their assigned clinical day. Participants completed a pretest before the simulation, posttest 1 immediately after the simulation, and posttest 2 at the end of the semester in May. The pretest and posttests consisted of the Cultural Humility Scale, the Cultural Self-Efficacy Scale, and the demographics survey. Data analysis revealed that although there was a statistically significant improvement in cultural humility and cultural self-efficacy immediately and over time after the simulation for both groups, there was no statistically significant difference between high-fidelity manikin simulation or SP simulation on either cultural humility, F(1,95) = 1.26, p = .27, ηp2 = .002, or cultural self-efficacy, F(1,95) = .11, p = .74, ηp2 = .001. Also, there were no differences in cultural humility or cultural self-efficacy based on the year of enrollment before or after the simulation. As no difference was found between using a manikin and using a standardized patient, nursing programs have a choice of using either approach based on the feasibility, cost, and available resources. Future research should include replications of this study as well as comparisons of other teaching modalities in simulation to increase cultural humility and cultural self-efficacy. Keywords: Cultural humility, cultural self-efficacy, nursing education, nursing students, clinical simulation, cultural humility scale, and cultural self-efficacy scale.