Digital Commons Network^™

Mantle Flow And Lithosphere-Asthenosphere Coupling Beneath The Southwestern Edge Of The North American Craton: Constraints From Shear-Wave Splitting Measurements, Hesham A. Refayee

Doctoral Dissertations

"High-quality broadband seismic data recorded by the USArray and other stations in the southwestern United States provide a unique opportunity to test different models of anisotropy-forming mechanisms in the vicinity of a cratonic edge. Systematic spatial variations of anisotropic characteristics are revealed by 3027 pairs of splitting parameters measured at 547 broadband seismic stations. The western and southern edges of the North American craton show edge-parallel fast directions with larger-than-normal splitting times, and the continental interior is characterized by smaller splitting times spatially consistent fast directions that are mostly parallel to the absolute plate motion direction of North America. Except …

Meso-Scale Fluidic Devices With Chemical Sensors For Biological Applications, Satya Gowthami Achanta

Doctoral Dissertations

"Molecular oxygen and humidity are some of the major environmental quantities being measured for various industrial and commercial applications. This dissertation focuses on the design, fabrication and characterization of optofluidic biosensor systems for oxygen and humidity quantification using color charge-coupled device (CCD) camera as a photodetector and LED panel as an excitation source. Meso-scale fluidic devices with integrated oxygen and humidity sensors for potential applications to hydrotropic and oxytropic studies of small plant roots have been investigated in this study. Meso-scale sensor platform was fabricated using porphyrine complex as the sensitive dye embedded within Ethyl Cellulose (EC) polymer matrix. Green …

Nitrification Performance Of Activated Sludge Under Low Dissolved Oxygen Conditions, Guoqiang Liu

Doctoral Dissertations

"The combined effects of solids retention time (SRT) and dissolved oxygen (DO) concentration on nitrification, nitrifying bacterial communities, and aeration needs in the activated sludge process were studied. Nitrification was almost completed in the 10, 20, and 40-day SRT reactors with a minimum DO of 0.37, 0.25, and 0.16 mg/L, respectively. Under long-term low DO conditions, the endogenous decay of nitrifiers was slowed down and then nitirfier biomass concentration increased, thereby reducing the adverse effect of low DO on nitrification. Under long-term low DO conditions, the oxygen affinity of nitrite-oxidizing bacteria (NOB) increased significantly and as a result, NOB became …

Plate Kinematics Of The Afro-Arabian Rift System With An Emphasis On The Afar Depression, Helen Carrie Bottenberg

Doctoral Dissertations

This work utilizes the Four-Dimensional Plates (4DPlates) software, and Differential Interferometric Synthetic Aperture Radar (DInSAR) to examine plate-scale, regional-scale and local-scale kinematics of the Afro-Arabian Rift System with emphasis on the Afar Depression in Ethiopia. First, the 4DPlates is used to restore the Red Sea, the Gulf of Aden, the Afar Depression and the Main Ethiopian Rift to development of a new model that adopts two poles of rotation for Arabia. Second, the 4DPlates is used to model regional-scale and local-scale kinematics within the Afar Depression. Most plate reconstruction models of the Afro-Arabian Rift System relies on considering the Afar …

Role Of Alloy Additions On Strengthening In 17-4 Ph Stainless Steel, Arpana S. Murthy

Doctoral Dissertations

"Alloy modifications by addition of niobium (Nb ), vanadium (V), nitrogen (N) and cobalt (Co) to cast 17-4 PH steel were investigated to determine the effect on mechanical properties. Additions of Nb, V, and N increased the yield strength from 1120 MPa to 1310 MPa while decreased the room temperature charpy V notch (CVN) toughness from 20 J to four Joules. The addition of Co to cast 17-4 PH steel enhanced the yield strength and CVN toughness from 1140 MPa to 1290 MPa and from 3.7 J to 5.5 J, respectively. In the base 17-4 PH steel, an increase in …

Spatial-Temporal Reasoning Applications Of Computational Intelligence In The Game Of Go And Computer Networks, Tae-Hyung Kim

Doctoral Dissertations

"Spatial-temporal reasoning is the ability to reason with spatial images or information about space over time. In this dissertation, computational intelligence techniques are applied to computer Go and computer network applications. Among four experiments, the first three are related to the game of Go, and the last one concerns the routing problem in computer networks.

The first experiment represents the first training of a modified cellular simultaneous recurrent network (CSRN) trained with cellular particle swarm optimization (PSO). Another contribution is the development of a comprehensive theoretical study of a 2x2 Go research platform with a certified 5 dan Go expert. …

Stability Challenges And Solutions In Current-Mode Controlled Power Electronic Converters, Seyed Mostafa Khazraei

Doctoral Dissertations

"This dissertation focuses on stability issues in single-staged and multi-staged current controlled power electronic converters. Most current-mode control (CMC) approaches suffer from sub-harmonic oscillations. An external ramp is usually added to solve this problem. However, to guarantee stability this ramp has to be designed for the worst possible case which consequently over damps the response. Adaptive slope compensation (ASC) methods are the solution for this problem. In paper 1 of this dissertation, first three ASC methods will be investigated and analyzed through their small signal models. Then, through simulation analyses and experimental test of a variable-input voltage converter the results …

Sustainable Engineering Practices In Transportation Projects, Kiran Rangarajan

Doctoral Dissertations

"Sustainability has become an important issue in transportation and infrastructure development projects. While several agencies are trying to incorporate a range of sustainability measures in their goals and missions, only a few planning agencies have been able to implement these policies and they are far from perfect. The low rate of success in implementing sustainable policies is primarily due to incomplete understanding of the system and the interaction between various elements of the system. The conventional planning efforts focuses mainly on performance measures pertaining to the system and its impact on the environment but seldom on the social and economic …

Numerical Simulations Of Fracture Propagation And Sealing: Implications For Wellbore Strengthening, Saeed Salehi

Doctoral Dissertations

"To mitigate the small tolerance between pore pressure and fracture gradients an engineering practice referred to as "wellbore strengthening" is conducted to increase the fracture gradient. The method relies on propping and/or sealing the fractures with specially designed materials. Different competing theories exist for physical wellbore strengthening mechanisms which can be categorized into two groups. The first group explains that strengthening happens as a result of increasing wellbore hoop stress when fractures are sealed while the second group emphasis is on fracture tip isolation with suitable materials and enhancing fracture propagation pressure. The numerical models and lab experiments …

Real-Time Supply Chain Predictive Metrics, William Scott Hunter

Doctoral Dissertations

"Supply chains drive the production world. Virtually all products use a supply chain to produce them and they can determine the success of companies using them. The ability to manage supply chains is currently a mix of relationship management and science, combining personal and company relationships with data analysis.

The increased dependency on supply chains has increased the need to develop and use predictive real-time metrics to manage supply chain risk, measure suppliers and drive performance. Current metrics used are reactive and stagnant in nature. Real-time metrics will allow supply chain professionals to better manage risk. Current management techniques include …

Decreasing Time To Market For A Medical Device: New Methods For The Product Development Process, Kelly Marie Davis

Doctoral Dissertations

"Through an example, led at a leading medical device company, this dissertation will demonstrate that by applying certain lean principals and tools to the development of a medical device, shortened development times can be obtained. The two papers presented in the dissertation will fill a gap in current literature. Literature presents lean techniques and applications used in many different industries. But, due to the uniqueness of the medical device industry, these general techniques are not ideal. New methods will be used and validated at a medical device company, Covidien. Instead of trying to implement many general lean principals to their …

Design And Experimental Study Of Turbo Equalization For Multiple Antenna Systems, Amirhossein Rafati

Doctoral Dissertations

"Multiple-input multiple-output (MIMO) wireless communication systems have attracted a lot of interest in the past decade due to their capability in delivering high spectral efficiency as well as their robust performance against fading. In MIMO inter-symbol interference (lSI) channels, a severe interference problem occurs due to the lSI and co-channel interference. Thus, the error propagation problem becomes more serious, and its mitigation has to be considered when designing the receiver. In this regard, a turbo equalizer which exchanges soft information between the equalizer and the decoder has been shown to be an effective method to combat the lSI caused by …

Influence Of Temperature And Microstructural Modification On Formability Of Magnesium Alloys, Arun Mohan

Doctoral Dissertations

"The ß-precipitate free AZ31, ß-precipitate rich AZ91 and a few Mg-Y-Zn alloys were studied to understand the dependence of Mg formability on microstructural condition and temperature. Friction stir processing (FSP) was used to refine the grain size and to obtain desirable distribution of precipitates in the matrix. Since Mg alloys exhibit challenges in achieving room temperature formability, superplastic deformation was utilized. This work focused on high strain rate superplasticity (HSRS, ≥10⁻² s⁻¹) which is more attractive for industrial applications as compared to the slower rates of conventional superplasticity.

Thermally stable fine grains and pinning particles at HSRS temperatures were essential …

Handel's Maser-Solution Theory Of Ball Lightning: The Creation Of Stable Three-Dimensional Cavitons By An Atmospheric Maser With An Open Resonator, Glenn Andrew Carlson

Doctoral Dissertations

"This dissertation develops details of Handel's Maser-Soliton Theory of ball lightning. The atmosphere between a thundercloud and the Earth's surface is modeled as an idealized stable open resonator with water vapor as the active medium and the thundercloud and Earth's surface as reflecting surfaces. The stable resonator generates a maser beam that narrows to the beam waist at the Earth's surface, which is assumed to be planar. Two candidate rotational transitions are identified within the v₁v₂v₃ = 010 vibrational band of water having wavelengths of 13.9 cm and 1.12 cm, and relevant spectroscopic parameters are retrieved from the HITRAN 2008 …

Investigation Of Different Approaches To Combine Cable Information And Near-Field Scan Data For Radiated-Field Estimation, Keong W. Kam

Doctoral Dissertations

"Near-field scanning is often used to solve EMC problems. Aside from the purpose of visualization of near-fields, measured near-field data can be used to estimate far-field. One of many challenges associated with using near-field to far-field transform (NFFFT) technique for EMC application is the handling of attached cables. The objective of this investigation is to evaluate different methods to add cable information to the near-field data for far-field estimation. The investigation is carried out using numerical experiments in EMCoS EMC studio, which is a commercial MoM (Method of Moment) tool for EM simulation. Measurement results from a test structure are …

Small Sample Inference For Exponential Survival Times With Heavy Right-Censoring, Noroharivelo Volaniaina Randrianampy

Doctoral Dissertations

"We develop a saddlepoint-based method and several generalized Bartholomew methods for generating confidence intervals about the rate parameter of an exponential distribution in the presence of heavy random right-censoring. Butler's conditional moment generating function formula is used to derive the relevant moment generating function for the rate parameter score function which provides access to a saddlepoint-based bootstrap method. Moment generating functions also play a key role in the generalized Bartholomew methods we develop. Since heavy censoring is assumed, the possible non-existence of the rate parameter maximum likelihood estimate (MLE) is nonignorable. The overwhelming majority of existing methods condition upon the …

Yin Yang Bipolar Atom - An Eastern Road Toward Quantum Gravity, Wen-Ran Zhang

Computing: Faculty Publications

Based on bipolar dynamic logic and bipolar quantum linear algebra, a causal theory of YinYang bipolar atom is introduced in a completely background independent geometry that transcends spacetime. The causal theory leads to an equilibrium-based super symmetrical quantum cosmology of negative-positive energies. It is contended that the new theory has opened an Eastern road toward quantum gravity with bipolar logical unifications of particle and wave, matter and antimatter, relativity and quantum entanglement. Information recovery after a black hole is discussed. It is shown that not only can the new theory be applied in physical worlds but also in logical, mental, …

Beyond Spacetime Geometry – The Death Of Philosophy And Its Quantum Reincarnation, Wen-Ran Zhang

Computing: Faculty Publications

Contrary to the “end” and “death” assertions on philosophy, this paper predicts an equilibrium-based and harmony-centered scientific reincarnation of philosophy. Logically, the reincarnation is backed by a formal system and a background independent geometry that transcends spacetime. Physically, it is supported by definable quantum causality and bipolar logical unifications of matter and antimatter, particle and wave, big bang and black hole, relativity and quantum entanglement. Philosophically, it is distinguished from Western metaphysics and dialectics as well as the Dao of Laozi. It is named a quantum reincarnation for its central claim that YinYang bipolar quantum entanglement is the source of …

Theoretical Studies Of Few-Body Problems, Uttam Chowdhury

Doctoral Dissertations

"Heavy ion collisions with atomic and molecular targets produce many outcomes. The Schrödinger equation is not analytically soluble for more than two mutually interacting particles. As a result, theory must resort to using approximations, the validity of which is determined by comparison with experiment. This work is focused on finding better approximations to describe ionization and capture processes in proton collisions.

Proton-impact ionization of molecular hydrogen is treated as a 3-body problem. Usually the target is treated as an atomic target and the results are multiplied by an ad hoc factor to account for the molecular structure. Measured cross sections …

Underground Mine Fire Simulation Using Multiscale Modeling Approach, Xichen Zhang

Doctoral Dissertations

"Underground mine fires have always been a major concern. Past events show that fire poses a severe safety hazard to mine workers, and causes tremendous economic loss to the mine and surrounding communities. A good understanding of the interaction between a mine fire and the mine ventilation network is crucial for effective fire emergency planning and hazard control. Unfortunately our understanding of a fire is still limited due to the complex nature of mine fires and a lack of adequate resource for studying them.

A new multiscale modeling approach coupling conventional 1D and 3D techniques has shown to be a …

Visualizing And Modeling Interior Spaces Of Dangerous Structures Using Lidar, Norbert H. Maerz, T. K. Assebaum, Dustin J. Williams, K. Shea, Yongjian Xi, Xiaoling Li, Ye Duan

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

LIght Detection and Ranging (LIDAR) scanning can be used to safely and remotely provide intelligence on the interior of dangerous structures for use by first responders that need to enter these structures. By scanning into structures through windows and other openings or moving the LIDAR scanning into the structure, in both cases carried by a remote controlled robotic crawler, the presence of dangerous items or personnel can be confi rmed or denied. Entry and egress pathways can be determined in advance, and potential hiding/ambush locations identifi ed. This paper describes an integrated system of a robotic crawler and LIDAR scanner. …

Distributed And Collaborative Watermarking In Relational Data, Prakash Kumar

Masters Theses

"Watermarking relational data is an important topic in the field of copyright protection, given the increasing prevalence of piracy and illegal duplication of databases. While there exists solutions for watermarking relational data, the problems that arise due to multiple ownership (two or more) of databases have not been acknowledged. This research focuses on developing a novel watermarking scheme to counter the problems. The watermarking scheme proposed necessitates the owners of the database in consideration to come together to perform the watermarking process. The scheme can be applied to insert watermarks in both numerical and categorical data. The watermarking scheme is …

Meaning, Purpose, And Cause In The Law Of Deception, Gregory Klass

Georgetown Law Faculty Publications and Other Works

Laws designed to affect the flow of information take many forms: rules against misrepresentation, disclosure requirements, secrecy requirements, rules governing the formatting or packaging of information, and interpretive rules designed to give people new reasons to share information. Together these and similar rules constitute the law of deception: laws that aim to prevent or cure deception. One encounters similar problems of design, function and justification throughout the law of deception. Yet very little has been written about the category as a whole. This article begins to sketch a general theory. It identifies three regulatory approaches. Interpretive laws, such as common …

The Distinctiveness Of Appellate Adjudication, Heidi Li Feldman

Georgetown Law Faculty Publications and Other Works

This paper concerns two topics which, I hope to show, are vitally connected. One is the distinctive importance of appellate adjudication in the legal system of United States. The other is the workings of entangled concepts in the law. That appellate adjudication is important in some sense may seem obvious to everybody (to a few it will seem obvious that appellate adjudication is unimportant). My point will be that via appellate adjudication courts engineer entangled legal concepts, and it is this aspect of appellate adjudication that is both crucial and unique to it, at least in the U.S. legal system. …

Depoliticizing Federalism, Louis Michael Seidman

Georgetown Law Faculty Publications and Other Works

In his great biography of President Andrew Jackson, Arthur Schlesinger, Jr. celebrated Jackson’s defense of the rights of states and opposition to federal power. Yet as a mid-twentieth century liberal, Schlesinger was a strong supporter of the federal government and an opponent of states’ rights. Was Schlesinger’s position inconsistent? He did not think so, and neither does the author. In Jackson’s time, an entrenched economic elite controlled the federal government and used federal power to dominate the lower classes. State governments served as a focal point for opposition to this domination. By mid-twentieth century, the federal government was an engine …

Judicial Engagement Through The Lens Of Lee Optical, Randy E. Barnett

Georgetown Law Faculty Publications and Other Works

Keynote remarks at the symposium on "Judicial Engagement and the Role of Judges in Enforcing the Constitution", delivered on March 22, 2012 at the George Mason University School of Law.

Advisory Adjudication, Girardeau A. Spann

Georgetown Law Faculty Publications and Other Works

The Supreme Court decision in Camreta v. Greene is revealing. The Court first issues an opinion authorizing appeals by prevailing parties in qualified immunity cases, even though doing so entails the issuance of an advisory opinion that is not necessary to resolution of the dispute between the parties. And the Court then declines to reach the merits of the underlying constitutional claim in the case, because doing so would entail the issuance of an advisory opinion that was not necessary to the resolution of the dispute between the parties. The Court's decision, therefore, has the paradoxical effect of both honoring …

The Eye Alone Is The Judge: Images And Design Patents, Rebecca Tushnet

Georgetown Law Faculty Publications and Other Works

Design patents are an area of intellectual property law focused entirely on the visual, unlike copyright, patent, trademark, trade secret, or the various sui generis protections that have occasionally been enacted for specific types of innovation. Judges and lawyers in general are highly uncomfortable with images, yet design patents force direct legal engagement with images. This short piece offers an outsider’s view of what design patent law has to say about the use of images as legal tools, why tests for design patent infringement are likely to stay unsatisfactory, and what lessons other fields of intellectual property, specifically copyright, might …

A Decision Theory Of Statutory Interpretation: Legislative History By The Rules, Victoria Nourse

Georgetown Law Faculty Publications and Other Works

We have a law of civil procedure, criminal procedure, and administrative procedure, but we have no law of legislative procedure. This failure has serious consequences in the field of statutory interpretation. Using simple rules garnered from Congress itself, this Article argues that those rules are capable of transforming the field of statutory interpretation. Addressing canonical cases in the field, from Holy Trinity to Bock Laundry, from Weber to Public Citizen, this article shows how cases studied by vast numbers of law students are made substantially more manageable, and in some cases quite simple, through knowledge of congressional procedure. …

Lessons From Social Psychology For Complex Operations, Rosa Brooks

Georgetown Law Faculty Publications and Other Works

This short essay looks at several social forces that powerfully affect human behavior, often trumping individual “character,” personality, knowledge, and even deeply held moral beliefs. Specifically, this essay looks briefly at issues of obedience, conformity, and group polarization, discussing the ways in which they can affect and distort individual behavior. Ultimately, this essay suggests, understanding these dynamics can have important implications for how we think about counterinsurgency and stability operations.