Digital Commons Network^™

The Moderating Influence Of Stress Appraisals And Affect On Performance Under Fatigue, Regina M. Schmidt

Browse all Theses and Dissertations

This study demonstrated that in a group of seventeen active duty soldiers, performance on an attack combat simulation significantly degraded after approximately 30 h of sleep deprivation. In addition, individual differences were identified, as approximately half of the participants maintained performance throughout the sleep deprivation period, while other participants degraded in performance. The main objective of this study was to test the efficacy of micro-level cognitive performance and subject state factors to account for this dichotomy in performance that was particular to the last testing session. Results showed that performance on a decision making test with rapid reaction time constraints …

The Dynamics Of Workplace Harassment And Revenge: Mediation And Moderation Effects, Qiang Wang

Browse all Theses and Dissertations

This study examined the mediating role of rumination, state anger, and blame attribution, and the moderating role of trait forgiveness in the relationship between workplace harassment and revenge behavior. Results based on a sample of 310 employed students suggested that workplace harassment is positively associated with both major revenge and minor revenge. Also, the multiple mediation test showed that rumination, state anger, and blame attribution completely mediate the proposed relationships between workplace harassment and both types of revenge behavior. In addition, as proposed, trait forgiveness moderated the relationship between two internal states (i.e., state anger and blame attribution) and major …

Analysis And Transformation Of Post-Conditions, Abhinav Vasikarla

Browse all Theses and Dissertations

Software engineers have been trying for years to develop a software synthesis system that can transform a formal specification model to a design model from which executable code can be generated. AFIT wide spectrum object modeling environment (AWESOME) is one result of their research. AWESOME presents a formal model as an abstract syntax tree. This model consists mainly of object class specifications. The methods in these classes are specified using pre and post-conditions. The intent of this thesis is to support the transformation of post-conditions to code statements. A post-condition is first categorized as dependent or independent relative to other …

Analytic-Holistic Thinking, Information Use, And Sensemaking During Unfolding Events, Mei-Hua Lin

Browse all Theses and Dissertations

In complex domains such as commerce, military operations, transportation, and humanitarian efforts, practitioners are sometimes overwhelmed by uncertain, contradictory, and dynamic information. They must obtain, organize, interpret, and use this information often under time pressure and high stakes during sensemaking. While sensemaking is a gateway to information management, sensemaking also depends on information management; the gathering and use of information provides the raw material for sensemaking. These processes work together to help people understand complex situations but are vulnerable to cultural as well as individual variation in cognition. This study investigated individual cognitive and personality differences that may affect information …

Fpga Design Of A Hardware Efficient Pipelined Fft Processor, Ryan T. Bone

Browse all Theses and Dissertations

Digital receivers involve fast Fourier transform (FFT) computations that require a large amount of arithmetic operations. The implementation of a FFT processor is one of the most challenging parts in the realization of a wideband receiver and its hardware complexity is very high. Hence, kernel function FFT processors have been proposed to meet real-time processing requirements and to reduce hardware complexity by rounding the kernel function to predetermined kernel points so as to eliminate the multipliers and use only shifters and adders or subtractors. Because of the nonlinear nature of this approximation by the rounding errors, spurious responses are generated …

Exploration Of Gradient-Type Poly(Arylene Ether)S Via An Abb' Monomer System, Alex V. Dolgov

Browse all Theses and Dissertations

Evidence shows that a gradient like copolymer can be synthesized using nucleophilic aromatic substitution, NAS, chemistry. Using the 4-chloro-3-fluoro-4'hydroxydiphenylsulfone monomer, 5, it is possible to control the ratios of the leaving groups, in this case the fluorine and the chlorine, with the right solvent and temperature. Alternating the temperatures will alter the substitution of the leaving groups, thus forming a polymer backbone of gradient characteristics. Initial reactions to determine the relative rates of displacement of the chlorine and fluorine atoms were carried out using a model compound, 1, which possessed the chlorine and fluorine leaving groups, but not the phenol …

Evanescent Microwave Microscopy Of Porcine Skin Tissue, Richard A. Kleismit

Browse all Theses and Dissertations

This thesis describes the application of a custom designed λ/4 resonant coaxial probe to measurements of the complex permittivity of in vitro freshly excised porcine skin tissue. The dielectric properties of the organic material within the near field of the tip of the probe frustrates the electric field and measurably changes the resonant frequency and quality factor Q of the coaxial sensor, where the change in resonant frequency and quality factor of a tuned resonance is measured as a function of tip-sample separation. The design of the probe enables better spatial resolution than previously developed probes. The following studies were …

Performance And Complexity Co-Evaluations Of Mpeg4-Als Compression Standard For Low-Latency Music Compression, Isaac Kevin Matthew

Browse all Theses and Dissertations

In this thesis compression ratio and latency of different classical audio music tracks are analyzed with various encoder options of MPEG4ALS. Different tracks of audio music tracks are tested with MPEG4-ALS coder with different options to find the optimum values for various parameters to obtain maximum compression ratio with minimum CPU time (encoder and decoder time). Optimum frame length for which the compression ratio saturates for music audio is found out by analyzing the results when different classical music tracks are experimented with various frame lengths. Also music tracks with varying sampling rate are tested and the compression ratio and …

Electrochemistry Of Trinuclear Metal Clusters Of Molybdenum And Tungsten In 1-Ethyl-3- Methylimidazolium Tetrafluoroborate, Tracey Lynn Harris

Browse all Theses and Dissertations

The imidazolium based ionic liquid: 1-ethyl-3-methylimidizoliumtetrafluoroborate, (EMIBF4) was synthesized to be used as a solvent for the electrochemical investigation of molybdenum and tungsten. The electrochemical window is about 4.2V after removing traces of impurities such as Cl^- and H₂O. Electronic spectra of metal clusters [Mo₃O₂(O₂CCH₃)₆(H₂O)₃]⁺² ; [W₃O₂(O₂CCH₃)₆(H₂O)₃]⁺² ; [MoW₂O₂(O₂CCH₃)₆(H₂O)₃]⁺² and [Mo_{2 …}

Poly(Arylene Ether)S With Truly Pendant Benzene Sulfonic Acid Groups, Mohamed Moustafa Abdellatif

Browse all Theses and Dissertations

A series of new sulfonated poly(arylene ether)s containing one sulfonic acid group, located on a pendant phenyl sulfonyl moiety, at every repeat unit was synthesized using 3-sulfonated-3', 5'-difluorophenyl Sulfone, 4, and a variety of bisphenols. A conventional nucleophilic aromatic substitution (NAS) was utilized for the homopolymerization and copolymerization reactions. Polymerization reactions of 4 in NMP at 180 °C provided the corresponding linear sulfonated poly(arylene ether)s, s-PAEs, with number average molecular weight, M_n, ranging from 10,000 to 38,000 Daltons. All of the polymers were characterized by ¹H and ¹³C NMR spectroscopy, thermogravimetric analysis (TGA), and differential scanning …

Histogram-Based Template Matching Object Detection In Images With Varying Brightness And Contrast, Christina Da-Wann Schrider

Browse all Theses and Dissertations

Our challenge was to develop a semi-automatic target detection algorithm to aid human operators in locating potential targets within images. In contrast to currently available methods, our approach is relatively insensitive to image brightness, image contrast and object orientation. Working on overlapping image blocks, we used a sliding difference method of histogram matching. Incrementally sliding the histograms of the known object template and the image region of interest (ROI) together, the sum of absolute histogram differences was calculated. The minimum of the resultant array was stored in the corresponding spatial position of a response surface matrix. Local minima of the …

Model And Solution Approaches For The Equipment Scheduling Under Disruption Problems In Usps Mail Processing And Distribution Centers, Arvindkumar Ravi Chakravarthy

Browse all Theses and Dissertations

This research addresses the equipment scheduling problem under disruptions in United States Postal Service mail processing and distribution centers. These facilities contain a large variety of equipment and employ a non-homogeneous workforce that work on shifts of various lengths and start times. The scheduling of equipment (the determination of the configuration and usage of equipment to match mail arrivals) and the scheduling of workforce (the determination of the optimal size and composition of the workforce, their days off / lunch assignments, and overtime usage) to meet processing service commitment with a constantly changing demand are some of the most challenging …

The In Pulse, William L. Hall

Browse all Theses and Dissertations

A collection of poems composed as an exercise with imagination and the attempt to convey the mind as medium for experience without forgetting the reader remembers something else.

Geologic Mapping Of The Changgo Dome In Southern Tibet Using Aster Imagery, Andrew Paul Folfas

Browse all Theses and Dissertations

Within the thick TSS, south of the Indus-Tsangpo Suture, a series of granitic intrusions and gneissic domes crop out along the NHA. These culminations are common features that are seen in orogenic belts; therefore, understanding the nature and development of these features is an integral part of this study and other collisional orogenic studies. Changgo Dome is a granitic dominated feature that is characterized by the presence of two spectrally similar Tertiary granites. This zone is nearly inaccessible for ground mapping, thus it is an ideal setting for the use of satellite imagery as a cartographic medium. In a previous …

In Search For New P53 Regulated Genes, Meldrick Daniel Mpagi

Browse all Theses and Dissertations

The p53 tumor suppressor protein has the ability to transactivate its target genes whose gene products are involved in carrying out cell cycle arrest, apoptosis, DNA repair, and senescence. Here, I report that two genes may be p53 regulated. Utilizing a microarray method to search for novel p53 target genes, I was able to identify a possible transcriptional target of p53 being solute carrier family 1a1 (SLC1a1). Along with that finding I also identified an E2F-target gene, minichromosome maintenance 10 (MCM10), as being p53 regulated. Gene expression profiling of MCF7 breast cancer cells treated with RNAi targeting Hdm2 and HdmX …

A Construct Validation Of The Neutral Objects Satisfaction Questionnaire (Nosq), Kevin J. Eschleman

Browse all Theses and Dissertations

The current study is a construct validation of the Neutral Objects Satisfaction Questionnaire (NOSQ). The study includes tests of convergent and discriminant validity. Specifically, the NOSQ had more empirical overlap with affective-oriented dispositions (i.e., positive affectivity, negative affectivity, neuroticism, extraversion, trait anxiety, trait anger, trait depression, and cheerfulness) than with cognitive-oriented dispositions (i.e., need for cognition, general self-efficacy, and locus of control). In addition, the NOSQ had greater empirical overlap with the aforementioned affective-oriented dispositions than with a measure of temporal affect (i.e., mood). Correlations between the NOSQ and both job satisfaction and job cognitions were also compared, but no …

A Stochastic Production Planning Model Under Uncertain Demand, Meenakshi Prajapati

Browse all Theses and Dissertations

Production planning plays a vital role in the management of manufacturingfacilities. The problem is to determine the production loading plan consisting of the quantity of production and the workforce level - to fulfill a future demand. Although the deterministic version of the problem has been widely studied in the literature, the stochastic production planning problem has not. The application of production planning models could be limited if the stochastic nature of the problem, for example, uncertainty in future demand, is not addressed. This study addresses such a stochastic production planning problem under uncertain demand and its application in an enclosure …

Biomechanical Evaluation Of Locked And Non-Locked Constructs Under Axial And Torsion Loading, Vinit A. Patel

Browse all Theses and Dissertations

Locking compression plates are proven to be safe for use in open reduction and internal fixation (ORIF). The ORIF is a procedure performed to treat fractures. It has various combination of holes, the system provides more options for clinicians to use either locking screw or non-locking screws. This thesis investigates and determines the best construct with special locking and non-locking screws under both axial and torsion loading. Twenty femur constructs were assembled with 2 cm osteotomy gap between femur shaft and condyle, bridged with 4.5 mm - 10 holes condyle plates. Femurs were divided in to 4 groups according to …

Dynamic Characterization Of A Pneumatic Muscle Actuator And Its Application To A Resistive Training Device, Jennifer L. Serres

Browse all Theses and Dissertations

Research described in this dissertation expands the use of a biomechanical phenomenological model to a commercially available pneumatic muscle actuator (PMA). Due to the nonlinearities of the device, achieving accurate control is challenging. Experiments have been conducted that define boundaries of operation where linear approximations can be used to describe the dynamics of the PMA. Empirical data presented in this dissertation show that nonlinearities exist more prevalently at higher loads (on average >70% contractile force value). When the PMA is under high loads, low displacement occurs. Therefore, these regions are of less interest to design engineers. Once conditions of nonlinearities …

A Novel Accurate Approximation Method Of Lognormal Sum Random Variables, Xue Li

Browse all Theses and Dissertations

Sums of lognormal random variables occur in many problems in wireless communications due to large-scale signal shadowing from multiple transmitters. With the emerging of cognitive radio technology, accurate analysis of interferences from multiple primary users and multiple secondary users is required. Such interferences are well modeled by the lognormal sum distribution. The lognormal sum distribution is known to have no close-form and is difficult to compute numerically. Several approximations to the lognormal sum distribution have been proposed and employed in literature. However, these approximation methods are not without their drawbacks. Some widely used approximation methods are not accurate at the …

Availability And Toxicity Of Nickel To Lotic Periphyton And Macroinvertebrates, Stephanie Marie Bessom

Browse all Theses and Dissertations

There is a lack of information regarding the bioaccumulation and toxicity of nickel (Ni) to lotic ecosystems. The objective of this study was to investigate the source, uptake, and toxicity of Ni by periphyton and macroinvertebrates (Hyalella azteca and Daphnia magna) in simulated stream ecosystems that included sediment and water. Periphyton were exposed to two types of sediment, a low-organic sandy mixture and a high organic silt, treated with varying levels of Ni. After 96 h, Ni levels in overlying water and periphyton were related to those in sediments, although differences existed between sediment types. Tests with 64Ni added to …

Motion-Control System Of Bench-Top Ct Scanner, Tarpit Kaushikbhai Patel

Browse all Theses and Dissertations

Computed Tomography (CT) imaging has found applications in many areas such as diagnostic visualization, quantitative estimation, and therapeutic verification. In this wide range of applications, a CT scanner that can provide the data collection schemes of both second- and third-generation data-collection geometries will be an asset for laboratory research. In this thesis project, we developed a mechanical design and constructed a dual-generation CT scanner that provides flexibility in accommodating a wide range of object sizes with minimum scan time. Using 3-D graphical design software, models of the current second-generation CT scanner and possible solutions for modification were simulated. Based on …

Exploring Team Dynamics: The Evolution Of Coordination In A Complex Command And Control Environment, Daniel H. Schwartz

Browse all Theses and Dissertations

The present study explores the dynamic and emergent behavior of two teams, separately working through a synthetic task environment representing a battle management command and control domain under two levels of organizational centralization. While the manipulation of centralization had minimal effects on overall performance, evidence suggested that the need to seek authorization for actions from a central authority was a source of frustration. Both teams adapted over time, changing patterns of coordination to better meet the task demands. The results are discussed in the context of the concepts of normal accidents, high reliability organizations, and self-organization in complex organizations. Specific …

Finite Element Optimization Of Hip Implant Geometrical Parameters To Determine Safe Zones And Resist Dislocation, Himanshu K. Bhatt

Browse all Theses and Dissertations

A computational study was performed using finite element analysis (FEA) of three dimensional solid hip implant models. Twelve different hip implant models were designed to investigate the performance of geometrical parameters affecting hip stability. The parameters examined were head diameter, neck diameter, head-to-neck ratio, neck angle and acetabular liner thickness. Component orientations included cup anatomical inclination and cup anteversion, which should be accounted for during total hip implant design as well as in the practice of arthroplasties. A static analysis was performed for all 12 hip designs using stainless steel 316L. von Mises stress, contact stress, contact penetration, and sliding …

Two Dimensional Localization Of Passive Uhf Rfid Tags, Bhavik Contractor

Browse all Theses and Dissertations

The advent of GPS has redefined the need of a positioning system in today*#8217;s ubiquitous computing world. While GPS works satisfactorily and is quite a norm in an outdoor environment, it fails to work indoors due to the inherent complexity of an indoor environment. There is an ever increasing need to develop an indoor positioning system and a lot of research has been done to solve the problem of indoor localization. These solutions differ on the basis of cost, dependency on environment, line of sight requirements and so on.

Passive RFID (Radio Frequency Identification) tags pose an interesting solution to …

A Low-Cost Acoustic Array For Detecting And Tracking Multiple Acoustic Targets, Ellen E. Case

Browse all Theses and Dissertations

A wide variety of real-world targets emit distinct acoustic signatures that not only distinguish them from one another but also provide spectral separation from background clutter. While acoustic signatures are distinct, they can also be highly variable, even for an individual target, making detection and tracking a challenging problem. This thesis presents a low-cost acoustic array using commercial off-the shelf (COTS) hardware to detect and track multiple small, moving, acoustic targets. It implements a cross-correlation method for calibration, delay-and-sum beamforming, CA-CFAR detection, a discrete Kalman filter for tracking, and nearest neighbor data association. In addition, the array is designed to …

Effects Of Forest Fragmentation And Honeysuckle Invasion On Forest Lepidoptera In Southwest Ohio, Annie Lynn Doyle

Browse all Theses and Dissertations

Habitat loss and exotic species invasion is a rapidly growing threat facing forest animal communities worldwide. The goal of the current study is to assess the impact of forest fragmentation and the associated invasion of honeysuckle on immature tree-feeding Lepidoptera communities in southwestern Ohio. Caterpillar abundance, richness, and honeysuckle density were sampled along 100 meter transects conducted in ten forest fragments. Generalized linear models were developed to determine the effects of fragment area, landscape forest cover, and honeysuckle density on caterpillar abundance and richness. Caterpillar abundance and richness was positively related to landscape forest cover and fragment area. However, these …

An Algorithm For The Detection Of Handguns In Terahertz Images, Andrew J. Lingg

Browse all Theses and Dissertations

This paper presents an algorithm for detecting handguns in terahertz images. Terahertz radiation is capable of penetrating certain materials which are opaque atoptical wavelengths, such as clothing, without the harmful effects of ionizing radiation. The approach taken is to segment objects of interest and classify them based on shape. We use a modified version of an active contour algorithm found in the open literature. Modifications include: a pre-processing step that includes clutter filtering and seeding of an initial contour; and a post-processing step that removes clutter pixels from the segmentation. The features used for classification are moment-based and Fourier shape …

Automated Analysis Of Metacarpal Cortical Thickness In Serial Hand Radiographs, Aarti Raheja

Browse all Theses and Dissertations

To understand the roles of various genes that influence skeletal bone accumulation and loss, accurate measurement of bone mineralization is needed. However, it is a challenging task to accurately assess bone growth over a person's lifetime. Traditionally, manual analysis of hand radiographs has been used to quantify bone growth, but these measurements are tedious and may be impractical for a large-scale growth study. The aim of this project was to develop a tool to automate the measurement of metacarpal cortical bone thickness in standard hand-wrist radiographs of humans aged 3 months to 70+ years that would be more accurate, precise …

Investigating Nickel Flux And Toxicity In Clay Sediments With Batch And Stream Recirculating Flume Experiments, Christina Elizabeth Cloran

Browse all Theses and Dissertations

Using batch and stream recirculating flume experiments to compare and contrast one clayey sediment (Warden Ditch) and two analytical grade clay minerals (montmorillonite and kaolinite), the dynamic interactions between two aquatic stressors (suspended solids and nickel) were explored. Aldrich humic acid was incorporated to demonstrate the mitigating effects of dissolved organic carbon (DOC) on Ni toxicity. The flux of Ni between compartments (dissolved and sorbed) was quantified as a partition/distribution coefficient. The USEPA test organism Daphnia magna (neonates, < 24 h) was utilized to evaluate toxicity in dynamic non-renewal, short-term bioassays. Generally, toxicity showed a linear relationship with turbidity level. Conversely, sorption coefficients were experiment specific, making them difficult to predict and assess. Clay functioned as an adsorbent, scavenging Ni. Results support the hypotheses that solids and metals act as stressors in streams, DOC attenuates the toxicity of Ni, and Ni fluxes quickly between system compartments.