This document presents a novel representation and evaluation framework for organizational structures. The SES Enterprise Alternative Evaluator (SEAE), while adhering to the broader focus of developing a design environment for manufacturing system configurations, will be used to design and evaluate a single product process. Enterprise representation, normally approached through the categorical qualitative and quantitative descriptive attributes of evaluation objectives, did not have a framework specifically focused on hierarchical enterprise design prior to this dissertation. The SES, in representing the manufacturing enterprise, includes alternative manufacturing system components within the design structure through entity specialization. SEAE enumeration produces the best set of these alternatives relative to the objectives during enterprise evaluation. The motivation for this research was two-fold. A primary consideration was to provide enterprise designers with a modular, flexible tool, incorporating current state-of-the-art modeling and simulation capabilities for use in hypothesis testing, development, and analysis. Enterprise modeling is presently devoid of a framework for simultaneously combining the strategic, tactical, and financial enterprise design considerations along the lines of common organization function hierarchical decompositions. The present approach is to provide a design structure, usually to combine prescriptive and descriptive methods, to achieve the representation. Preliminary results of this tool's use are presented for designing and evaluating Terrasun L. L. C.'s manufacturing system.

Cellular manufacturing has been extensively adopted as a measure to reduce cycle time, increase productivity, and improve product quality. The past research in cellular manufacturing has focused on the methodology for identification of machine groups, part families, and determination of processing routes while the relocation of existent workers into cells and their training for cellular manufacturing environment have been ignored. However, several industrial surveys show that human and administrative issues are a major unsolved problem in implementing cells. Human issues in the cell formation process have received little attention in the literature. This dissertation develops methods for guiding the assignment of workers to cells and determination of training plans and task assignments for workers. An integer programming model is first proposed to determine the assignment of workers to cells and the aggregate training needs for each cell with consideration of meeting the technical and administrative skill requirements in each cell. In addition to the technical and administrative skills, team synergy level predicted on the basis of the combination of individual personality-related traits, and individual job fitness are then included in the consideration for building high performance teams. A mixed integer programming model is formulated with objective to create effective manufacturing teams meeting cell requirements with low training cost, high team synergy level, and compatibility between workers and tasks. Several solution methods including greedy heuristics, beam search, filtered beam search, and simulated annealing techniques are developed for solving the mathematical models. They are tested and compared to a standard optimization software for a set of test problems. Results indicate that problem size, initial mix of skills, and the skill requirements of cells in the data set impact the difficulty of obtaining good solutions. Nevertheless, it appears that heuristics such as beam search are capable of obtaining good solutions with reasonable computational effort. Directions for future work are discussed at the conclusion of this dissertation.

<p> Sensing and site data acquisition are active areas of research for industrial applications, particularly, for construction engineering and management. A number of research initiatives around the globe are focused on noble sensing applications for managing site safety, productivity improvements, progress monitoring, site lay out planning, and for innovative approaches to supply chain management. Time of Flight (TOF) cameras and laser scanners are the tools of choice for real time and near real time decision making on jobsites. However, most of these applications are limited to academic research and limited field trials have been carried out. A number of operational decisions are necessary before sensing equipment can be deployed. These decisions are challenging for companies and researchers alike as there is limited test data available regarding the performance characteristics for the various equipment options. Recently with technological advances, Microsoft introduced a very affordable new TOF sensor, Xbox Kinect for video games. The objective of this research is to investigate potential industrial applications of this device to monitor industrial environment for safety and modeling purposes. First we conducted designed experiments and characterized the accuracy and resolution of Xbox Kinect sensors as well as the interference between multiple Xbox Kinect sensors. The experiments provided quantitative knowledge about the performance of XBOX Kinect sensors in terms of spatial modeling. Second, using the experimental results as the baseline for Kinect performance, we developed optimal placement methods of Kinect sensors to maximize detection area or performance using fuzzy and heuristic algorithms. Third, we investigated the application of Kinect sensors for 3D reconstruction and rapid modeling and reported its performance in comparison with two other methods..</p>

<p> The United States (US) military conducts frequent Humanitarian Assistance missions. In terms of numbers of operations, the US military has conducted more of these missions since the end of the Cold War than it has traditional war-fighting missions. Despite the frequency of these operations, the performance of the military is often criticized for not understanding the humanitarian operating environment or failing to make the best use of available assets and resources. </p><p> This research develops models of the information requirements, internal organization and processes that military staffs use when conducting a war-fighting operation and then when conducting a Humanitarian Assistance Operation. The models are then analyzed to determine how the staffs develop Situation Awareness in each case. Specifically, for each case it is determined how the staff perceives, or gathers, information required for performance of the mission; how well the staff comprehends or understands this information; and then how the staff uses the information to predict or project the impact of military actions on the future state of the environment. </p><p> Based on the results of the analysis, proposed changes to the current Humanitarian Assistance model are developed to enable the staff to achieve the same level of Situation Awareness as the staff conducting a war-fighting mission. Additionally, proposals are made for how a staff conducting a war-fighting operation with humanitarian aspects, such as a counter-insurgency operation, can leverage aspects of Situation Awareness development from the Humanitarian Assistance Model.</p>

<p> The process of capturing solid geometry as 3 dimensional data requires the use of laser based reverse engineering hardware, known as a digitizer. Many digitizers exist as articulated coordinate measuring machines augmented with a laser, which forces the operator into many postures that are not ergonomically sound, particularly in the operator's upper body. This study analyzes the traditional method of laser digitizing using modern methods and technologies. An alternative user interface using an occluded head-mounted monocular display is hypothesized and evaluated.</p>

The aim of this work was to devise and investigate a solvent extraction system for rhodium, from aqueous chloride solutions, having potential industrial applicability. The extractant investigated was Kelex 100, a commercially available derivative of 8-hydroxyquinoline. Ultimately, two different systems were developed. Both are based on an initial complexation reaction between the aqueous rhodium chloride complexes, (RhCl$ rm sb{6-n}(H sb2O) sb{n} rbrack sp{(3-n)-}$ and stannous chloride, referred to as the activation stage, but the two systems use a different Sn:Rh molar ratio. In both cases, the Rh-Sn complexes, either (Rh(SnCl$ sb3) sb5 rbrack sp{4-}$ or (RhCl$ rm sb3(SnCl sb3) sb3 rbrack sp{3-},$ respond well to extraction with Kelex 100. One of the main differences between the two systems is in the stripping medium which is used to transfer the rhodium from the loaded organic phase back into an aqueous phase. In the case of the high Sn:Rh ratio feeds, the stripping stage is based on sulfuric acid, whereas in the case of low Sn:Rh ratio feeds, the rhodium is stripped from the organic phase using a sulfite containing hydrochloric acid solution. / The two systems were characterized in terms of their equilibrium and kinetic behaviour during all three stages; activation, extraction, and stripping. Activation was found to proceed either at room temperature or at elevated temperatures and the above-mentioned expected Rh-Sn complexes were identified through $ sp{119}$Sn NMR and Raman spectroscopy. The extraction stage was found to be quantitative for rhodium and it was also found to be very rapid, with contact times of less than five minutes sufficient for rhodium extraction. The extraction mechanism was determined to be ion-pair formation with the protonated Kelex 100 molecules at a stoichiometry such that the overall charge in the organic phase is neutral, i.e., three Kelex 100 molecules for (RhCl$ rm sb3(SnCl sb3) sb3 rbrack sp{3-}$ and four for (Rh(SnCl$ sb3) sb5 rbrack sp{4-}.$ / The stripping stages were the most problematic for both systems. In one case, the system was eventually abandoned due to limitations in the amount of rhodium which could be transferred to the sulfuric acid strip solution. For the low Sn:Rh system, reasonable rhodium transfer and concentration level were obtained. The rhodium complex in the strip solution has been proposed to be (RhCl$ rm sb2(SO sb3) rbrack sp{3-}.$ Strip solutions up to $4 times10 sp{-2}$M in rhodium concentration have been produced, from initial feed solutions having a rhodium concentration of about $4 times10 sp{-3}$M. Preliminary flowsheets are proposed for further refinement for both systems, although only the second system, the low Sn:Rh ratio system which uses sulfite stripping, is advocated for further development.

Emulsification behaviour caused by gas bubbles rising through a slag/metal interface was studied in both a thin-slice model and a three-dimensional model using low temperature oil/aqueous and oil/mercury analogues. A generalized model characterizing the transitional volume of droplets entrained in the upper phase in the emulsification process was developed. The transient volume of "metal" entrained, $ rm V sb{d}(t),$ following the start of bubbling followed the relation $ rm V sb{d}(t)=V sb{ propto}(1-e sp{-t/ tau}).$ Based on this model, the birth rate and mean residence time of droplets dispersed by rising bubbles could be quantified. Dimensional analysis was used to express the volume of lower liquid carried up into the emulsion per bubble, thereby allowing better estimates of the droplet birth rate in a practical emulsification process induced by bottom blowing. Emulsification behaviour in industrial in-bath smelting processes were interpreted with the present modelling results. / Slag foaming in "in-bath" iron smelting was modelled by injecting gas through a porous disc into a vertical cylinder containing a variety of low temperature liquids. Based on experimental evidence and theoretical arguments, difficulties with previous studies characterizing foam height as a function of fluid properties were addressed, and an alternative analysis in the form of a general relationship was developed. The fractional volume of gas holdup, $ varepsilon,$ in foaming slags containing large spherical cap bubbles could be expressed as $ rm varepsilon=U sb{g}/ lbrack U sb{g}+(0.5gd sb{b}) sp{0.5} rbrack.$ The average bubble size in the foaming slag of the AISI pilot trials on the smelting reduction of iron ores was estimated to be 10-25 cm equivalent diameter, suggesting that significant coalescence of small bubbles (such as CO) occurs in the process. / In modelling the mixing behaviour of ferroalloy additions in intensively stirred reactors, the AOD process was used to simulate slag chrome oxide reduction period by ferro-silicon additions. These phenomena were examined with the aid of a two dimensional slice model and then a three dimensional model using low temperature oil/aqueous analogues. Based on these modelling studies, it was observed that the ascending gas/liquid plume created two asymmetric mixing zones: a smaller mixing zone near the side wall fitted with tuyeres and a larger main mixing zone away from it. In "slag free" experiments, a dead zone formed at the far surface corner opposite the tuyeres. There, the particles simulating ferro-alloy additions accumulated. However, in the "slag covered" model experiments, the injected gas generated an emulsified "slag/metal" phase of lower apparent density which lead to the entrainment of the buoyant ferro-silicon alloy additions. This, in conjunction with the significantly modified flow patterns, and absence of any dead zones, allowed the particles simulating ferroalloy additions to be readily entrained within the recirculation flow. These results suggest that the mixing-in of such additions into the molten slag during the chrome oxide reduction period can be accomplished efficiently.

In this research, entropy is proposed as a measure of flexibility. First, entropy is presented by tracing its origins in thermodynamics to its role in information theory. Properties of entropy that make it a suitable measure of flexibility are outlined. After that, the strategic importance of flexibility is established. Then, previous research on definitions of flexibility and different measures of flexibility are discussed, as well as entropic measures developed by other researchers. This leads to proposing a entropy as general measure of process flexibility that can be used on a dynamic basis, i.e., along a time continuum. A mathematical model is developed as well as the application of entropy within the model. A computer simulation of a job shop model is used to test the measure through a number of different scenarios. Results of the simulation show that entropy succeeds in measuring flexibility when the relative demands of products change, but is not successful when the relative demands do not change or change a little. It is concluded that entropy is a relative measure that can be used to monitor process flexibility with time, but needs to be combined with other parameters to be of more practical use.

Mathematical and stochastic computer models were built to simulate concurrent engineering processes (CE) in order to study how different process mechanisms contribute to new product development (NPD) performance. Micro-models of various phenomena which occur in concurrent engineering processes, such as functional participation, overlapping, decision-making, rework, and learning, were included, and their effects on the overall NPD process were related to process span time and effort. The study focused on determining under what conditions CE processes are more favorable than sequential processes, in terms of expected payoff, span time, and effort, as dependent variables of functional participation and overlapping, and the corresponding trade-offs between more upfront effort versus span time reduction.

<p> Vascularization of thick engineered tissue and organ constructs like the heart, liver, pancreas or kidney remains a major challenge in tissue engineering. Vascularization is needed to supply oxygen and nutrients and remove waste in living tissues and organs through a network that should possess high perfusion ability and significant mechanical strength and elasticity. In this thesis, we introduce a fabrication process to print vascular conduits directly, where conduits were reinforced with carbon nanotubes (CNTs) to enhance their mechanical properties and bioprintability. The generation of vascular conduit with a natural polymer hydrogel such as alginate needs to have improved mechanical properties in order to biomimic the natural vascular system. Carbon nanotube (CNT) is one of the best candidates for this goal because it is known as the strongest material and possesses a simple structure. </p><p> In this thesis, multi-wall carbon nanotube (MWCNT) is dispersed homogenously in the hydrogel and fabricated through an extrusion-based system.In vitro evaluation of printed conduits encapsulated in human coronary artery smooth muscle cells was performed to characterize the effects of CNT reinforcement on the mechanical, perfusion and biological performance of the conduits. Perfusion and permeability, cell viability, extracellular matrix formation and tissue histology were assessed and discussed, and it was concluded that CNT-reinforced vascular conduits provided a foundation for mechanically appealing constructs where CNTs could be replaced with natural protein nanofibers for further integration of these conduits in large-scale tissue fabrication. It was concluded that MWCNT has a significant effect on mechanical properties, vascular conduit swelling ratio and biological characterization in short-term and long-term cellular viability.</p>