This qualitative, inductive study analyzed online recruiting information posted at the websites of five major aerospace and defense corporations to recruit college juniors, seniors, and recent graduates. Recruitment of this group is critical to staff the personnel for the scientific, technical, and management needs of aerospace and defense industries. The study sought: (1) to determine the use of multiple recruitment factors inferred from the literature and recommended for successful recruitment of college graduates, (2) to determine use of online social media (Facebook, Twitter, LinkedIn) to recruit this population, and (3) to explore commonalities among these corporations regarding online recruiting information to determine if a model for online recruitment now exists. A matrix of recruitment factors was developed from a review of the literature on the personnel needs of this industry and on effective recruiting factors for this group. Content analysis involved filtering information at each website with the matrix. Conclusions of this study include: (1) the matrix of recruitment factors and the rating scale developed for the purposes of this study provide a tool for researching, documenting, and comparing recruitment information on the internet; (2) that while these corporations represent the latest applications in technology in their manufacturing processes and products, they do not use social networking technology to the extent the popular and scholarly literature indicate is typical for the target group. Given that the current generation exhibits extensive use of social media, several of these corporations’ websites appear not to utilize this networking technology. Informally, these corporations argue that cyber-security prevents extensive use of social networking sites. Thus, these corporations must determine how to maintain cyber-security while at the same time adopting more accepted use of social networking platforms.

In already optimized processes it may be challenging to find room for further improvement. The solution can be found in the advanced software and tools that support the digital manufacturing, all the way from planning and design to in-machining and machining analysis. This project the- sis focuses on developing a process methodology to transcribe Sandvik Coromant’s theories and knowledge about machining operation grooving into machine-readable formats. Various software development models have been analysed and a particular model inspired by the incremental and iterative process model was developed to match the context of this project. This project thesis describes the working methodology for gathering theories and translating them into machine-interpretable format. A working methodology developed in this project thesis succeeded in transcribing different human- readable theories such as people’s minds (experts within the field) and handbooks into a machine- interpretable format. The proposed algorithms for tool path generation was developed and imple- mented successfully through the integration of mathematical modelling. MATLAB and Siemens NX has been used to build a proof of concept environment.

Sexual minorities consistently report more alcohol use than heterosexual individuals, and sexual minority women tend to report more alcohol use than sexual minority men (Amadio, 2006; Kerr et al., 2015; Rosario et al., 2014). Some evidence suggests that this disparity in comparison to heterosexuals may be problematic drinking, such as binge drinking and alcohol dependence, rather than just higher consumption of alcohol. Thus, it is important to examine which variables are related to problematic drinking among sexual minority women. One factor that may explain problematic drinking for sexual minority women is proximal minority stress, such as anticipated stigma (expectations of unfair treatment) and internalized stigma (negative attitudes toward the self about one’s sexual orientation) (Meyer, 2003). Previous research has found that internalized stigma predicts more problematic drinking (Feinstein & Newcomb, 2016; Lea et al., 2014). Additionally, proximal minority stress may be indirectly related to problematic drinking through variables like depression, social support, and drinking motives (Lehavot & Simoni, 2011; Lewis et al., 2016). However, findings on anticipated stigma have inconsistently shown a relationship with problematic drinking (Hatzenbuehler et al., 2008; Reisner et al., 2015). The current study tested a path analysis model examining how proximal minority stress may be related to problematic drinking among sexual minority women. Participants included 101 women who identified as lesbian, bisexual, and other non-heterosexual orientations. Participants were mainly white, and came from all regions of the United States (Northeast, South, Midwest, West). They completed the following measures: the Internalized Stigma Subscale of the Perceived Stigma Scale (Mickelson, 2001), the Discrimination Scale (adapted from Williams, 1997), the Multidimensional Scale of Perceived Social Support (Zimet et al., 1988), the Center for Epidemiological Studies Depression Scale (Radloff, 1977), the Drinking Motives Questionnaire (Cooper, 1994), and the AUDIT (Saunders et al., 1993). The final model tested anticipated stigma and internalized stigma as predictors of social support and depression; depression significantly predicted coping and enhancement motives, which in turn predicted problematic drinking. Age, living in the Northeast, and being a racial/ethnic minority were covariates of depression, internalized stigma and social support respectively. A path analysis conducted via EQS determined that the model had good fit (Chi-square/df = 1.10, p = 0.32, CFI = .988, SRMR = 0.082, RMSEA = .032 (90% CI [0.001, 0.082]). These results support the hypotheses that minority stress is related to more problematic drinking through depression and substance use motives. Findings could suggest that future research and interventions should examine the replacement of negative coping mechanisms, like drinking, with more positive coping mechanisms among sexual minority women.

A fundamental understanding of ultrafast nonequilibrium dynamical processes in molecular aggregates is crucially important for the design of nanodevices that utilize quantum mechanical effects. However, understanding the coupled electron-phonon dynamics of such high-dimensional systems remains a challenging issue. As a result of the ever-growing computational power that is available, realistic parameterization of model Hamiltonians and implementation of sophisticated quantum dynamics algorithms have become indispensable tools for gaining insight into these processes. The focus of this dissertation is the development and implementation of approximate path integral-based methods to compute the time-evolution as well as linear and nonlinear spectroscopic signals of molecular aggregates following photo-excitation. The developments and applications presented here are geared toward gaining a better understanding of the role that electron-phonon coupling plays in framing ultrafast excitation energy transfer networks in photosynthetic light-harvesting complexes. The ultrafast excitation energy transfer dynamics that occurs upon photo-excitation of a network of electronically coupled chromophores is remarkably sensitive to the strength of electronic coupling as well as the frequencies and coupling strengths that characterize electron-phonon interactions. Based on approximations to the diabatic representation of molecular Hamiltonians, energetic models of condensed phase molecular aggregates can be parameterized from a first principles description. Often times, computational parameterization of these models reveals comparable magnitudes for intermolecular electronic couplings and electron-phonon couplings, negating the applicability of popular perturbative algorithms (such as those based on Forster or Redfield theory) for describing their time-evolution. Moreover, non-perturbative exact methods (e.g. stochastic Schrodinger equations and the Hierarchical Equations of Motion) are generally inefficient for all but a few specific limiting forms of electron-phonon coupling, or make assumptions about autocorrelation timescales of the vibrational environment. Because of the failure of the energetic parameters determined through recent ab initio studies of natural molecular aggregates to abide by the rather restrictive requirements for efficient application of the above-mentioned methods, the development of approximate non-perturbative algorithms for predicting nonequilibrium dynamical properties of such systems is a central theme in this dissertation. Following a general introductory section describing the basic concepts that are fundamental to the remainder of the thesis, the derivation of path integral dynamics methods is presented. These include a cartesian phase space path integral derivation of the truncated Wigner approximation as applied to the Meyer-Miller-Stock-Thoss mapping model for describing vibronic systems as well as a novel derivation of the Partially Linearized Density Matrix algorithm, highlighting its emergence as a leading order approximation to an, in principle, exact expression for the density matrix. An algorithm for computing the nonlinear response function for higher-order optical spectroscopy signals is presented within the framework of the partially linearized density matrix formalism. Time-resolved two-dimensional electronic spectra are computed and compared with exact results as well as standard perturbation theory-based results, highlighting the accuracy and efficiency of the developed method. Additionally, the recently popularized symmetrical quasi-classical method for computing the reduced density matrix dynamics is extended for computing linear optical spectroscopy signals, and compared with results from the partially linearized density matrix treatment. A generalization of the model Hamiltonian form utilized in recent ab initio studies is presented, allowing for direct vibrational energy relaxation due to coupling between intramolecular normal modes and their environment. The consequences of including these interactions within a model Hamiltonian that is inspired by energetic parameters found in studies of a photosynthetic light-harvesting complex are highlighted in the context of density matrix dynamics and time-resolved two-dimensional electronic spectroscopy. The results indicate that this physical process can be utilized as a means of optimizing the efficiency of excitation energy transfer and localization. Inspired by ab initio characterization of model Hamiltonians for molecular aggregates, a new approximate semiclassical propagator for describing the time-evolution of a system consisting of discrete electronic states in the presence of both high-frequency harmonic vibrational modes as well as slow environmental DOFs with arbitrary potentials is presented. Results indicate that this algorithm provides a more accurate description in this parameter regime than standard linearized path integral methods such as the partially linearized density matrix algorithm and the truncated Wigner approximation. Finally, preliminary results of dynamics involving non-perturbative field-matter interactions is presented with emphasis on strategically shaped pulses, field design through optimal control, and non-perturbative pump-probe spectroscopy.

In geometry we will consider n-dimensional generalizations of the Power of a Point Theorem and of Pascal's Hexagon Theorem. In generalizing the Power of a Point Theorem, we will consider collections of cones determined by the intersections of an (n-1)-sphere and a pair of hyperplanes. We will then use these constructions to produce an n-dimensional generalization of Pascal's Hexagon Theorem, a classical plane geometry result which states that "Given a hexagon inscribed in a conic section, the three pairs of continuations of opposite sides meet on a straight line." Our generalization of this theorem will consider a pair of n-simplices intersecting an (n-1)-sphere, and will conclude with the intersections of corresponding faces lying in a hyperplane. In graph theory we will explore the interaction between zero forcing and cut-sets. The color change rule which lies at the center of zero forcing says "Suppose that each of the vertices of a graph are colored either blue or white. If u is a blue vertex and v is its only white neighbor, then u can force v to change to blue." The concept of zero forcing was introduced by the AIM Minimum Rank - Special Graphs Work Group in 2007 as a way of determining bounds on the minimum rank of graphs. Later, Darren Row established results concerning the zero forcing numbers of graphs with a cut-vertex. We will extend his work by considering graphs with arbitrarily large cut-sets, and the collections of components they yield, to determine results for the zero forcing numbers of these graphs.

A grid graph is a finite embedded subgraph of the infinite integer grid. A solid grid graph is a grid graph without holes, i.e., each bounded face of the graph is a unit square. The reconfiguration problem for Hamiltonian cycle or path in a sold grid graph G asks the following question: given two Hamiltonian cycles (or paths) of G, can we transform one cycle (or path) to the other using some "operation" such that we get a Hamiltonian cycle (or path) of G in the intermediate steps (i.e., after each application of the operation)? In this thesis, we investigate reconfiguration problems for Hamiltonian cycles and paths in the context of two types of solid graphs: rectangular grid graphs, which have a rectangular outer boundary, and L- shaped grid graphs, which have a single reflex corner on the outer boundary, under three operations we define, flip, transpose and switch, that are local in the grid. Reconfiguration of Hamiltonian cycles and paths in embedded grid graphs has potential applications in path planning, robot navigation, minimizing turn costs in milling problems, minimizing angle costs in TSP, additive manufacturing and 3D printing, and in polymer science. In this thesis, we introduce a complexity measure called bend complexity for Hamiltonian paths and cycles in grid graphs, and using those measures we measure complexity of a grid graph G and give upper and lower bounds on the maximum bend complexity of an mxn grid graph. We define three local operations, flip, transpose and switch, where local means that the operations are applied on vertices that are close in the grid graph but may not be close on the path or cycle. We show that any Hamiltonian cycle or path can be reconfigured to any other Hamiltonian cycle or path in an mxn rectangular grid graph, where m <= 4, using O(|G|) flips and transposes, regardless of the bend complexities of the two cycles. We give algorithms to reconfigure 1-complex Hamiltonian cycles in a rectangular or L-shaped grid graph G using O(|G|) flips and transposes, where the intermediate steps are also 1-complex Hamiltonian cycles. Finally, we establish the structure of 1-complex Hamiltonian paths between diagonally opposite corners s and t of a rectangular grid graph, and then provide a strategy, based on work in progress, for designing an algorithm to reconfigure between any two 1-complex s, t Hamiltonian paths using switch operations. / Graduate

This thesis is concerned with the problem of planning paths for autonomous cars through a smart traffic intersection. In this thesis, we describe existing concepts for solving this problem and discuss the possibilities of approaching intersection problems theoretically. Then, we choose one specific approach and design a declarative model for solving the problem. We use that model to perform a series of theoretical experiments to test the throughput and the quality of intersection paths described by different graphs. After that, we translate theoretical plans to actions for real robots and run it. In these experiments, we measure the degree of robots desynchronization and performance success of the plans based on the collision rate. We also describe how to improve action translation to achieve better performance than that for real robots following the straightforward plans.

In the event of a disaster, first responders must rapidly gain situational awareness about the environment in order to plan effective response operations. Unmanned ground vehicles are well suited for this task but often require a strong communication link to a remote ground station to effectively relay information. When considering an obstacle-rich environment, non-line-of-sight conditions and naive navigation strategies can cause substantial degradations in radio link quality. Therefore, this thesis incorporates an unmanned aerial vehicle as a radio repeating node and presents a path planning strategy to cooperatively navigate the vehicle team so that radio link health is maintained. This navigation technique is formulated as an A*-based search and this thesis presents the formulation of this path planner as well as an investigation into strategies that provide computational efficiency to the search process. The path planner uses predictions of radio signal health at different vehicle configurations to effectively navigate the vehicles and simulations have shown that the path planner produces favorable results in comparison to several conceivable naive radio repeating variants. The results also show that the radio repeating path planner has outperformed the naive variants in both simulated environments and in field testing where a Yamaha RMAX unmanned helicopter and a ground vehicle were used as the vehicle team. Since A* is a general search process, this thesis also presents a roadway detection algorithm using A* and edge detection image processing techniques. This algorithm can supplement unmanned vehicle operations and has shown favorable performance for images with well-defined roadways. / Master of Science

In this thesis, strategies for navigating a crowded area using an autonomous holonomic robot are discussed and evaluated. The focus is set on path planning and the topic is therefore largely decoupled from the prediction (i.e. machine learning) and control theory techniques needed for a practical implementation outside of the simulated environment. Existing methods and algorithms for path planning in highly dynamic environments are compared using several measures via computer simulations in different environments. A new, effective, and yet simple, algorithm is introduced and proven to be useful in certain scenarios. This algorithm, ART, predicts the future states of the crowd and using these predictions finds better paths to the goal than traditional algorithms. / I detta examensarbete utvärderas och diskuteras strategier för navigering bland folk med hjälp av en självstyrd holonomisk robot. Fokus är satt på navigeringsproblemet i sig och närliggande ämnen som maskininlärning och reglerteknik behandlas ej även om en fördjupning på dessa områden vore nödvändigt för en praktisk implementation utanför den simulerade världen. Existerande strategier och algoritmer för navigering av dynamiska miljöer utvärderas genom datorsimuleringar i varierande miljöer. En ny algorithm presenteras och visar sig vara användbar i vissa situationer. Denna algoritm, ART, förutser folkmassans rörelser och använder denna information för att hitta bättre vägar till målet.

This thesis consists of two projects in the field of machine learning. Previous research in the OSCAR UNT lab based on KMeans color quantization is further developed and applied to individual color channels and segmented input images to explore compression rates while still maintaining high output image quality. The second project implements a small-scale dual path network for image classifiaction utilizing the CIFAR-10 dataset containing 60,000 32x32 pixel images ranging across ten categories.