Digital Commons Network^™

Process Variation-Aware Timing Optimization With Load Balance Of Multiple Paths In Dynamic And Mixed-Static-Dynamic Cmos Logic, Kumar Yelamarthi

Browse all Theses and Dissertations

The semiconductor technology has been advancing rapidly over the past decade to result in the design of several innovative applications. This advancement of technology with the shrinking device has allowed for placement of billions of transistor on a single microprocessor chip. On the other hand, this shrinking device sizes has presented the design engineers with two major challenges: timing optimization at multiple giga-hertz frequencies, and reducing the daunting effects of semiconductor process variations. Failure to account for these process variations often results in loss of design productivity by one generation, and might even result in design failure.

This research presents …

Effects Of Subcutaneous Postnatal Choline Supplementation On Hippocampus-Mediated Learning And Memory In Rat Pups, Jeremy Alan Moore

Browse all Theses and Dissertations

The effects of postnatal injections of choline on the acquisition of two variants of eyeblink conditioning were examined in developing Long-Evans rat pups. Choline administration on postnatal days (PND) 15-27 was followed by evaluation of trace eyeblink conditioning (Experiment 1) and delay eyeblink conditioning (Experiment 2) on PND 28-29. The results of these experiments show that choline produced greater improvements in learning and memory during the trace condition than in the delay condition, presumably due to its effect on the hippocampus. Trace eyeblink conditioning relies heavily on an intact hippocampus but delay eyeblink conditioning does not, and it is understood …

Intelligent Spectrum Sensor Radio, Omer Mian

Browse all Theses and Dissertations

A cognitive radio is a radio with built-in intelligence that makes it able to utilize the radio frequency spectrum more efficiently by adapting to the changing conditions and frequency availability. In this thesis a spectrum sensor radio is designed that detects transmissions in FM band and determine the range of used and unused frequencies within the band. The radio then starts a transmission on a frequency among the available frequencies. This intelligent radio system design is implemented using the Universal Software Radio Peripheral and GNU Radio with a program written in python that uses a number of GNU Radio modules …

The Impact Of Nutrient Availability And Algal Community On Carbon Isotope Fractionaion In Crystal Lake, Clark County, Ohio, April R. Wisebaker

Browse all Theses and Dissertations

Crystal Lakes are a group of four interconnected lakes, located in southwestern Clark County, Ohio. Several studies have looked at separate geochemical and isotopic information at this location. However, no one has thoroughly studied the relationship between the algal community, geochemistry, and carbon isotope fractionation within Crystal Lake. The fractionation of carbon isotopes of dissolved inorganic carbonate is greatly affected by the process of photosynthesis; the amount of photosynthesis is affected by the amount of algae in the aquatic community; the amount of algae is affected by the available nutrients in system. Therefore, there should be a correlation between the …

Social Realism In Central America: The Modern Short Story Translated, James P. Geary

Browse all Theses and Dissertations

Contemporary Central America fiction writers offer realistic scenarios that often concentrate on the effects of globalization, the inevitable forces of transnational corporations, the global media, and government policy in the region. These writers show how racism and tensions between the social classes perpetuates division and alienates union between unique ethnic groups of the underprivileged majority. The dominant class in Central America, in collaboration with the United States threatens diverse cultures and causes their autonomous identities to become diluted and their very existence to become endangered. The Central American short story has a tendency to express various inequalities. It shows how …

Composite Membranes For Proton Exchange Membrane Fuel Cells, Jinjun Shi

Browse all Theses and Dissertations

Proton exchange membrane fuel cells (PEMFCs), often regarded as a green energy source, have become a promising candidate to replace traditional power sources. One of the obstacles toward commercialization of PEM fuel cells is lack of high performance and low cost proton exchange membranes. The objective of this study was to develop and evaluate higher-performance, Nafion-based composite proton exchange membranes that are suitable for operating at higher temperatures (> 85°C).

Proton exchange membranes were prepared by adding silica and heteropolyacids (HPAs) to a proton-conducting polymer matrix, Nafion. The added silica powder particles, either by direct mixing or sol-gel reaction, were …

System Design Of Undersea Vehicles With Multiple Sources Of Uncertainty, Todd W. Benanzer

Browse all Theses and Dissertations

The work performed investigates the system design and optimization of an undersea vehicle. The system design is driven by the available components, the missions the vehicle is required to perform, and the performance the system configuration yields. The system design consists of three design modules: path planning, component selection and sizing, and structural analysis. The path planning module uses a novel application of the Particle Swarm Optimization algorithm named Path Planning by Additive Freedom. Additionally, the unknown aspects of the mission space through which the path propagates are dealt with using an uncertainty quantification method known as Evidence Theory. Component …

Algorithmic Techniques Employed In The Isolation Of Codon Usage Biases In Prokaryotic Genomes, Douglas W. Raiford Iii

Browse all Theses and Dissertations

While genomic sequencing projects are an abundant source of information for biological studies ranging from the molecular to the ecological in scale, much of the information present may yet be hidden from casual analysis. One such information domain, trends in codon usage, can provide a wealth of information about an organism's genes and their expression. Degeneracy in the genetic code allows more than one triplet codon to code for the same amino acid, and usage of these codons is often biased such that one or more of these synonymous codons is preferred. Isolation of translational efficiency bias can have important …

The Influence Of Family In The Preservation Of Appalachian Traditional Music: From The Front Porch To Performance, Kathy Q. Hayes

Browse all Theses and Dissertations

The purpose of this project was to extend the literature on the influence of family in the preservation of Appalachian traditional music since few scholars have focused their research on this topic. The family was the first institution in the Appalachian Mountain area, and families preserved the music by performing in their homes for themselves and friends. Families preserved the traditional music, passing it down to future generations. The music was a part of the everyday life of the Appalachian people, and it was performed, remembered, and taken with them wherever they went. Even though the music changed as the …

Stress Reducing Effects Of Oxytocin In A Maternal Separation Paradigm, Keely Jane O'Connell

Browse all Theses and Dissertations

This study compared the effects of centrally and peripherally administered oxytocin (OT) on HPA axis activity and the presence of both stress-induced active and passive behaviors in female guinea pig pups (Cavia porcellus) after 180-min of isolation . In Experiment 1, one dose of oxytocin (10μg/.2ml) was injected subcutaneously into the periphery. Plasma cortisol levels were reduced after 180-min of isolation and two passive behaviors, eye-closure and crouch, were reduced as well with the administration of oxytocin. In Experiment 2, two different doses (10μg/.2ml and 20μg/.2ml) were injected into the periphery with no significant results. In Experiment 3 one dose …

Sensitization To Trail-Induced Apoptosis In K-Ras 12 Mutant Pancreatic Cancer Cells By Bitc, Christina Ann Wicker

Browse all Theses and Dissertations

Pancreatic adenocarcinoma is an aggressive cancer with a greater than 95% mortality rate and short survival after diagnosis. Chemotherapeutic resistance hinders successful treatment. This resistance is associated with mutations within codon 12 of the K-Ras gene (K-Ras 12), which is present in over 90% of all pancreatic adenocarcinomas. Codon 12 mutations maintain Ras in a constitutively active state leading to continuous cellular proliferation. Our study determined if TRAIL resistance in pancreatic adenocarcinomas with K-Ras 12 mutations could be overcome by first sensitizing the cells with Benzyl isothiocyanate (BITC). BITC is a component of cruciferous vegetable extracts and a cell cycle …

Mdm2 Amplification In Nih3t3l1 Preadipocytes Leads To Mdm2 Elevation In Terminal Adipogenesis, Vaughn Litteral

Browse all Theses and Dissertations

The p53 protein is a tumor suppressor protein that is mutated or non-functional in nearly all cancers. The Mdm2 protein has the ability to functionally inactivate p53 and these two proteins have been studied extensively in the context of cellular proliferation. In this study, expression of the murine double minute 2 (mdm2) gene was examined in the mouse NIH3T3L1 cell line. Under the proper conditions, the immortalized NIH3T3L1 cells have the ability to differentiate from fibroblasts to adipocytes (Green et al., 1975). This well characterized cell line provides an excellent model to study mdm2 in differentiation. While evaluating the regulation …

The Effects Of Nutritional Supplement, Mass Fx™, On Muscular Strength, Body Composition, And Blood Chemistries In Resistance Trained Adult Males, Patrick S. Dib

Browse all Theses and Dissertations

The purpose of this study was to determine the effects of a nutritional supplement, Mass FX, on muscular strength, body composition, and blood chemistries in resistance-trained adult males. Eight subjects, mean age 25 +/- 3.02 years, were randomly assigned to two groups (n=4). Each group was given either Mass FX or a Placebo in a double-blind manner to be taken orally for six weeks (4caps/day regardless of bodyweight). For the duration of the study, both groups were following the same training program and a diet customized to each subject's bodyweight in conjunction to the supplementation. Data were analyzed using Analysis …

Energy Efficient Image Video Sensor Networks, Paul Anthony Bender

Browse all Theses and Dissertations

Image Video Sensor Networks are emerging applications for sensor network technologies. The relatively large size of the data collected by image video sensors presents new challenges for the sensor network in terms of energy consumption and channel capacity. We address each of these issues through the use of a high density network deployment utilizing some nodes as dedicated relay nodes.

A high density network allows network nodes to reduce their transmission power. This reduction in transmission power allows each node to conserve power and simultaneously increases the potential for spatially concurrent transmissions within the network, resulting in improved network throughputs. …

A Study Of Multi-Echelon Inventory Systems With Stochastic Capacity And Intermediate Product Demand, Suman Niranjan

Browse all Theses and Dissertations

The research in this dissertation involves the study of several multi-echelon inventory systems with stochastic capacity and intermediate product demand. Specifically we analyze the behavior of the system which consists of several intermediate product demands. The analysis is primarily three fold i) developed update (relational) equations for all the multi-echelon inventory systems under several inventory allocation policies, ii) develop two simulation optimization approaches 1) OptQuest framework, and 2) IPA (Infinitesimal Perturbation Analysis) framework, used to minimize the total cost of the inventory systems that satisfy the desired customer service level, iii) obtain numerical results for all the multi-echelon inventory systems …

Shore Wives: The Lives Of British Naval Officers' Wives And Widows, 1750-1815, Amy Lynn Smallwood

Browse all Theses and Dissertations

This thesis provides an analysis of the lives of mid- to late-eighteenth century Royal Navy officers'wives and widows, including how they coped with the challenges of being separated from their husbands for extended periods of time. This separation forced them to accept additional financial and management responsibilities. By successfully managing these tasks, they proved that women were capable of managing money, purchasing property, rearing and educating children, working the patronage system, being political activists, dealing with bureaucracy, and networking. Shore wives performed these duties with the very real fear that their husbands might never come home alive. By taking up …

How Openness To Experience And Prejudicial Attitudes Shape Diversity Training Outcomes, Suzanne L. Dean

Browse all Theses and Dissertations

This study investigated the effectiveness of diversity training on a diversity training outcome measure when considering participant levels of Openness to Experience, sexism, and racism. Because past literature has demonstrated a positive relationship between Openness to Experience and training outcomes and a negative relationship between prejudicial attitudes and diversity training outcomes, these variables were treated as main effects in Multiple Regression equations. This study demonstrated that diversity awareness training increases participant understanding of legal issues related to workplace diversity. However, diversity training outcomes were not greatly affected by implicit or explicit prejudicial attitudes or Openness to Experience.

Creating A New Guatemala: The 1952 Agrarian Reform Law, Tiffany Kwader Harbour

Browse all Theses and Dissertations

In 1952, Guatemala enacted the Agrarian Reform Law Decree 900. The Decree became an instrument for national development through land redistribution and the development of agrarian rights. Although the law was only upheld for eighteen months, the Decree influenced land and labor legislation through today. Struggles for agrarian rights continued throughout the military dictatorship and civil war which plagued Guatemala until the signing of the 1996 Peace Accords. Ideals for land reform originating in the 1952 law continue to have a pervasive influence on the Guatemalan land reform movement. This study is further contextualized and framed with quotes and analysis …

Evaluation Of Overlay/Underlay Waveform Via Sd-Smse Framework For Enhancing Spectrum Efficiency, Vasu D. Chakravarthy

Browse all Theses and Dissertations

Recent studies have suggested that spectrum congestion is mainly due to the inefficient use of spectrum rather than its unavailability. Dynamic Spectrum Access (DSA) and Cognitive Radio (CR) are two terminologies which are used in the context of improved spectrum efficiency and usage. The DSA concept has been around for quite some time while the advent of CR has created a paradigm shift in wireless communications and instigated a change in FCC policy towards spectrum regulations. DSA can be broadly categorized as using a 1) Dynamic Exclusive Use Model, 2) Spectrum Commons or Open sharing model or 3) Hierarchical Access …

Object Similarity Through Correlated Third-Party Objects, Ting Sa

Browse all Theses and Dissertations

Given a pair of objects, it is of interest to know how they are related to each other and the strength of their similarity. Many previous studies focused on two types of similarity measures: The first type is based on closeness of attribute values of two given objects, and the second type is based on how often the two objects co-occur in transactions/tuples.

In this thesis we study a new behavior-based similarity measure, which evaluates similarity between two objects by considering how similar their correlated third-party object sets are. Behavior-based similarity can help us find pairs of objects that have …

Transformation Of Object-Oriented Associations And Embedded References To Them, Sneha Swamy

Browse all Theses and Dissertations

AFIT Wide Spectrum Object Modeling Environment (AWSOME) automatically generates executable code by applying transforms to the formal specifications developed from the domain knowledge. AWSOME uses the specification language called as AFIT Wide Spectrum Language (AWL). All the transforms developed for AWSOME depend on and manipulate Abstract Syntax Trees (ASTs) created by parsing the formal specifications of a model. The main idea is to speed the process of creating error free code, to aid reusability of code and also to make the maintenance changes to be consistent and correct. The AWSOME metamodel contains the structural (object) model, the functional (operations) model …

The Effect Of Dissolved Air On The Cooling Performance Of A Partially-Confined Fc-72 Spray, Rebekah Lee Puterbaugh

Browse all Theses and Dissertations

The objective of this thesis is to investigate the heat transfer performance of a partially-confined FC-72 spray with varying dissolved air concentrations. An experimental test rig consisting of a spray chamber coupled to a fluid delivery loop system was used to obtain temperature, pressure, and critical heat flux (CHF) data. A downward facing nozzle within the spray chamber allowed the FC-72 fluid to be sprayed onto an upward facing, thick-film, resistor heater. The heater was mounted onto a glass post, with a sump system to allow removal of excess fluid. Type-E thermocouples were imbedded in the post to obtain temperature …

Exploration Of Synthetic Routes To The Sulfoxide And Sulfone Derivatives Of Benzotrithiophenes, Tiffany M. Hall

Browse all Theses and Dissertations

The synthesis of new organic materials that have the potential to be utilized in a thermoelectric application are in demand because they are able to convert thermal energy directly into electrical energy. The "end-on" sulfoxide and sulfone derivatives of Benzo[1,2-c:3,4-c':5,6-c'']trithiophene 1 were synthesized for this reason. The "end-on" mode sulfoxide derivative 13 of Benzo[1,2-c:3,4-c':5,6-c'']trithiophene 1 was prepared by utilizing 3-Carboxypyridinium Chlorochromate (CPCC) 16 and AlCl₃, as an oxidizing system. The ¹H NMR (DMSO-d₆) spectrum displayed a singlet peak at 5.03 ppm, and the IR spectrum displayed an absorption at 1059.33cm^-1, which confirmed its …

Design Of A Cmos Rf Front End Receiver In 0.18Μm Technology, Vishwas Kudur Sastry

Browse all Theses and Dissertations

An RF front end receiver system refers to the analog down conversion stages of the wireless communication system. The Digital base-band signals cannot be transmitted directly through wireless channels due to the properties of electromagnetic waves. The baseband signals need to be converted to analog through a digital-to-analog converter (DAC), up converted to higher frequency using an up conversion mixer and then transmitted through the channel. The received signals are down converted to base band frequency and then converted to digital again using the analog to digital converter (ADC). The processes which the analog signal undergoes at the RF front …

Paleoenvironment And Lateral Extent Of An Exposed Carbonate Build-Up: Horry County, South Carolina, Lisa A. Raterink

Browse all Theses and Dissertations

A carbonate build-up exposed in the Intracoastal Waterway in Horry County, South Carolina is estimated to be Pleistocene to Pliocene in age. The carbonate build-up discontinuously spans approximately 12 kilometers of the waterway. Prominent formations in the area consist of the Waccamaw and the Canepatch Formation. A distinct sand layer is present laterally between the build-up and the excavated waterway bank, which consists primarily of well preserved fossil molluscs and echinoderms.

Field observations show that the carbonate build-up is bluish-gray in color and composed of shell fragments, predominantly mollusc, in a mud matrix. Thin sections analyzed, using a petrographic microscope, …

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 …