Physical Sciences and Mathematics Commons^™

Enhancement Of Margrave Deconvolution And Q Estimation In Highly Attenuating Media Using The Modified S-Transform, Adnan Djeffal

Dissertations, Master's Theses and Master's Reports

We evaluate the performance of the Margrave deconvolution and spectral ratio methods using the Gabor, S-, and modified S transforms in highly attenuating media, where the quality factor changes with depth dramatically. Our results substantiate that the modified S-transform deconvolution is more robust in terms of generating fewer artifacts and providing better estimates of reflectivities than the Gabor transform. The results also show that using the modified S-transform in the spectral ratio method produces better Q estimates than the S-transform and the Fourier transform that is conventionally used in the spectral ratio method. This improvement in the estimates of reflectivities …

Reservoir Characterization Through Pre-Stack Seismic Analysis And Inversion In The Thrace Basin, Northwest Turkey, Emre Doguturk

Dissertations, Master's Theses and Master's Reports

This study analyzes hydrocarbon reservoirs by using Amplitude-Versus-Offset (AVO) analysis and different inversion methods to investigate hydrocarbon reservoir in the Thrace Basin which is located in northwest Turkey.

A 3D seismic survey containing prestack data was provided by Turkish Petroleum Corporation as true amplitude NMO corrected 3D gathers.

The quality of this land data was poor for AVO applications, and steps were taken to make it useful. Radon filtering proved to be extremely useful for this purpose. Although application of this filter affected the AVO characteristics differently depending on the parameters selected for the filter, relative AVO characteristics remained useful …

Can Seismic Velocity Stacking Errors Result In The Low-Frequency Shadow?, Umit Serhan Inan

Dissertations, Master's Theses and Master's Reports

The low-frequency shadow is the area on reflection seismic data, underneath gas reservoirs, that exhibits anomalously low frequency. This phenomenon has been related to the highly attenuating nature of the gas reservoir, which could explain the low-frequency shadows observed underneath extremely thick reservoirs, but not the ones underneath thin reservoirs. There are several other mechanisms that could be responsible, however detailed analysis of these possible explanations is yet to be found in the literature.

The main focus of this research is to test the possible contribution of stacking of offset seismic data, namely, their mis-stacking, to the generation of the …

Communication Patterns And Strategies In Software Development Communities Of Practice, Shreya Kumar

Dissertations, Master's Theses and Master's Reports

Some of the greatest challenges in the relatively new field of software development lie in the decidedly old technology of communication between humans. Software projects require sophisticated and varied communication skills because software developers work in a world of incomplete, imperfect information where teams evolve rapidly in response to evolving requirements and changing collaborators. While prescriptive models for software process such as Agile suggest ways of doing, in reality these codified practices must adapt to the complexities of a real workplace. Patterns, rather than rules of behavior within software process are more suitable to the varied and mutable nature of …

Single Particle-Inductively Coupled Plasma-Mass Spectrometry Technology Development For Metallic Nanoparticle Characterization In Complex Matrices, Yongbo Dan

Doctoral Dissertations

"As the rapid growing of nanotechnology, the release of engineered nanoparticles (ENPs) into the environment is inevitable. After entering the real environment, ENPs tend to react with different components of the ecosystem (e.g. water, soil, air, plants) and make their characterization difficult. Analyzing ENPs in these complex matrices still remains as a grand challenge. ENPs characterization is normally the first step of risk assessment. Current analytical techniques have shown some limitations in revealing the unique characteristics of ENPs in complex matrices and reliable analytical techniques are in urgent need. Single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) is an emerging …

Modeling Daily Electricity Load Curve Using Cubic Splines And Functional Principal Components, Abdelmonaem Salem Jornaz

Doctoral Dissertations

"Forecasting electricity load is very important to the electric utilities as well as producers of power because accurate predictions can cut down costs by avoiding power shortages or surpluses. Of specific interest is the 24-hour daily electricity load profile, which provides insight into periods of high demand and periods where the use of electricity is at a minimum. Researchers have proposed many approaches to modeling electricity prices, real-time load, and day-ahead demand, with varying success. In this dissertation three new approaches to modeling and forecasting the 24-hour daily electricity load profiles are presented. The application of the proposed methods is …

Spectroscopic And Spectro-Astrometric Analysis Of T Tauri Stars, Logan Ryan Brown

Doctoral Dissertations

"To understand our own solar origins, we must investigate the composition of the protoplanetary disk from which the solar system formed. To infer this, we study analogs to the early solar system called T Tauri stars. These objects are low-mass, pre-main sequence stars surrounded by circumstellar disks of material from which planets are believed to form. We present high-resolution, near-infrared spectroscopic data for the T Tauri stars DR Tau and AA Tau using NIRSPEC at the Keck II telescope. For DR Tau, a spectro-astrometric analysis was performed, obtaining sub-seeing spatial information on water emission. Alongside a disk model, we constrained …

Unconventional Phase Transitions In Random Systems, Hatem Nuri Barghathi

Doctoral Dissertations

"In this thesis we study the effects of different types of disorder and quasiperiodic modulations on quantum, classical and nonequilibrium phase transitions. After a brief introduction, we examine the effect of topological disorder on phase transitions and explain a host of violations of the Harris and Imry-Ma criteria that predict the fate of disordered phase transitions. We identify a class of random and quasiperiodic lattices in which a topological constraint introduces strong anticorrelations leading to modifications of the Harris and Imry-Ma criteria for such lattices. We investigate whether or not the Imry-Ma criterion, that predicts that random field disorder destroys …

Properties Of Amorphous Transparent Conducting And Semiconducting Oxides From First Principles, Rabi Khanal

Doctoral Dissertations

"Amorphous transparent conducting and semiconducting oxides possess properties superior or comparable to their crystalline counterparts. The structure-property relationship in amorphous oxides is not nearly as well understood as in the case of the crystalline transparent conducting oxides. We have employedab initio molecular dynamics and a liquid quench approach to simulate amorphous oxide structures and performed density functional-based calculations to study the electronic properties of several amorphous conducting and semiconducting oxides with various cation compositions.

The effect of amorphization in oxides was investigated by taking indium oxide as a progenitor of the system. From the thorough study it was confirmed …

Seismic Reflection, Well Log, And Gravity Analysis Of The Thrace Basin, Northwestern Turkey, Murat Kuvanc

Graduate Theses/Dissertations

The Thrace basin is located between the Paleogene the Istranca and Rhdope massifs in the northwestern part of Turkey. Sediments in the Thrace basin accumulated during the early Eocene to the late Miocene, and the basin includes normal and strike-slip faults that were mainly formed in the Miocene. The hydrocarbon potential of the Thrace basin has been investigated by analyzing seismic reflection, well log, and gravity data since the 1930s; the basin has a huge gas reservoir potential and contains the first gas production field in Turkey. To determine the geologic and geophysics features of a portion of the basin …

พอลิเมอร์ผสมของพอลิแล็กทิกแอซิดและเซลลูโลสแอซีเทตจากผักตบชวา, กรองกาญจน์ อมตาริยกุล

Chulalongkorn University Theses and Dissertations (Chula ETD)

เซลลูโลสอะซิเทดถูกสังเคราะห์โดยใช้เซลลูโลสผักตบชวาเป็นวัตถุดิบ ซึ่งส่วนที่ใช้จะเป็นส่วนของก้านขั้นตอนแรกนำเส้นใยผักตบชวาไปกำจัดสิ่งสกปรกก้านแห้งและตามมาด้วยการฟอกสีไฮโปคลอไรเซลลูโลสให้เป็นสีขาวสีขาวแล้ว หลังจากนั้นเตรียมเซลลูโลสเจลโดยใช้โซเดียมไฮดรอกไซด์ / ยูเรีย / น้ำ (7:12:81 โดยน้ำหนัก) จากนั้นนำมาผสม ปริมาณของไวนิลอะซิเตทโดยมีอัตราส่วนต่างกันคือ 3.0, 5.0, 7.0, 9.0, 11.0% โดยน้ำหนักของเซลลูโลส หลังจากนั้นส่วนผสมที่ถูกเก็บไว้ในตู้แช่แข็งเป็นเวลา 6 ชั่วโมงเพื่อให้เกิดปฏิกิริยาแอซิทิเลชันสมบูรณ์ เซลลูโลสอะซิเตทมีความสามารถในการปรับปรุงคุณสมบัติของพอลิแล็กทิกแอซิดโดยการเปลี่ยนเป็นผลึกที่สมบัติเชิงกลและสมบัติทางความร้อน จุดมุ่งหมายของการศึกษาครั้งนี้คือการสังเคราะห์ เซลลูโลสแอซิเทดจากผักตบชวาโดยใช้พอลิไวนิลอะซิเตตสารช่วยเพิมความเข้ากันได้ (Compatiblizer) จากนั้นพอลิแล็กทิกแอซิด / เซลลูโลสอะซิเทดนำไปผสมกันโดยใช้เครื่องอัดรีดเกลียว หลังจากนั้นนำไปวิเคราะผล ดังนี้ วิเคราะห์หมู่ฟังก์ชันโดยใช้ฟูเรียทรานสฟอร์มสเปกโตรสโคปี (FTIR) วิเคราห์ความเป็นผลึกด้วยเครื่องเอกซ์เรย์ดิฟแฟรกโทรมิเตอร์(XRD) และ วิเคราะห์สัณฐานวิทยาด้วยกล้องจุลทรรศน์อิเล็กตรอนแบบส่องกราด(SEM) พบว่าพอลิแล็กทิกแอซิด / เซลลูโลสอะซิเตทโดยความเข้มข้นที่เหมาะสมที่สุดของเซลลูโลสอะซิเตทสำหรับการผสมกับพอลิแล็กทิกแอซิด เป็น 11% โดยน้ำหนักและสัดส่วนของพอลิแล็กทิกแอซิด/เซลลูโลสแอซิเทดคือ 95 : 5

Higher Order Z-Ideals In Commutative Rings, Themba Dube, Oghenetega Ighedo

Mathematics, Physics, and Computer Science Faculty Articles and Research

We study ideals that resemble z-ideals in commutative rings with identity. For each positive integer n, we say an ideal of a commutative ring A is a zⁿ-ideal in case it has the property that if a and b belong to the same maximal ideals of A, and aⁿ ϵ I , then bⁿ is also in I. The set of all zⁿ-ideals of A is denoted by A --> ʒⁿ (A). This gives an ascending chain ʒ(A) < ʒ²(A) < ʒ³(A) <… of collections of ideals, starting with the collection of z-ideals. …

No Return To Classical Reality, David Jennings, Matthew S. Leifer

Mathematics, Physics, and Computer Science Faculty Articles and Research

At a fundamental level, the classical picture of the world is dead, and has been dead now for almost a century. Pinning down exactly which quantum phenomena are responsible for this has proved to be a tricky and controversial question, but a lot of progress has been made in the past few decades. We now have a range of precise statements showing that whatever the ultimate laws of Nature are, they cannot be classical. In this article, we review results on the fundamental phenomena of quantum theory that cannot be understood in classical terms. We proceed by rst granting quite …

Enabling Method To Design Versatile Biomaterial Systems From Colloidal Building Blocks, Shalini Saxena, L. Andrew Lyon

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Development of materials with fine spatial control over topographical, mechanical, or chemical features has been investigated for a variety of applications. Here we present a method to fabricate an array of polyelectrolyte constructs including two-dimensionally and three-dimensionally patterned assemblies using both compressible and incompressible colloidal building blocks. This method eliminates prior constraints associated with specific chemistries, and can be used to develop modular, multi-component, patterned assemblies. In particular, development of constructs were investigated using microgels, which are colloidally stable hydrogel microparticles, polystyrene (PS) beads, and PS-microgel core-shell building blocks in conjunction with the polycation poly(ethyleneimine) (PEI). The topography, mechanical properties, …

Success Stories And Emerging Themes In Conservation Physiology, Christine L. Madliger, Steven J. Cooke, Erica J. Crespi, Jennifer L. Funk, Kevin R. Hultine, Kathleen E. Hunt, Jason R. Rohr, Brent J. Sinclair, Cory D. Suski, Craig K. R. Willis, Oliver P. Love

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The potential benefits of physiology for conservation are well established and include greater specificity of management techniques, determination of cause–effect relationships, increased sensitivity of health and disturbance monitoring and greater capacity for predicting future change. While descriptions of the specific avenues in which conservation and physiology can be integrated are readily available and important to the continuing expansion of the discipline of ‘conservation physiology’, to date there has been no assessment of how the field has specifically contributed to conservation success. However, the goal of conservation physiology is to foster conservation solutions and it is therefore important to assess whether …

Accommodating Retrocausality With Free Will, Yakir Aharonov, Eliahu Cohen, Tomer Shushi

Mathematics, Physics, and Computer Science Faculty Articles and Research

Retrocausal models of quantum mechanics add further weight to the conflict between causality and the possible existence of free will. We analyze a simple closed causal loop ensuing from the interaction between two systems with opposing thermodynamic time arrows, such that each system can forecast future events for the other. The loop is avoided by the fact that the choice to abort an event thus forecasted leads to the destruction of the forecaster's past. Physical law therefore enables prophecy of future events only as long as this prophecy is not revealed to a free agent who can otherwise render it …

Regional Variations Of Optimal Sowing Dates Of Maize For The Southwestern U.S., Boksoon Myoung, Seung Hee Kim, Jinwon Kim, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Sowing date (SD) is sensitive to regional climate characteristics; thus, it is critical to systematically examine the effects of SD on crop yields for various temperature regimes. We performed a sensitivity study of SD for maize in the southwestern U.S. using the regionally extended version of the Agricultural Production Systems sIMulator (APSIM) model. The model was run utilizing North American Regional Reanalysis at a 32 km resolution from 1991 to 2011, with an irrigation threshold at 95% of the soil water-holding capacity. Two types of SD optimizations maximizing yield potential (Yp), varying spatially or interannually, revealed that the optimal SD …

Sensitivity Of Maize Yield Potential To Regional Climate In The Southwestern U.S., Seung Hee Kim, Boksoon Myoung, David Stack, Jinwon Kim, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

The sensitivity of maize yields to the regional climate in the Southwestern U.S. (SWUS) has been investigated by using the Agricultural Production Systems sIMulator (APSIM) model in conjunction with meteorological forcings [daily maximum and minimum temperature (Tmax and Tmin), precipitation, and radiation] from the North American Regional Reanalysis (NARR) dataset. Sensitivity experiments showed that potential crop production responded nonlinearly to variations in Tmax, Tmin, and downwelling solar radiation at the surface. Mean annual yield potential (Yp) was changed by -3.0 and 1.79 Mg ha-1 for the +1 and -1 standard deviations (σ) of Tmax variation for entire the SWUS. The …

The Spectral Theorem For Quaternionic Unbounded Normal Operators Based On The S-Spectrum, Daniel Alpay, Fabrizio Colombo, David P. Kimsey

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this paper we prove the spectral theorem for quaternionic unbounded normal operators using the notion of S-spectrum. The proof technique consists of first establishing a spectral theorem for quaternionic bounded normal operators and then using a transformation which maps a quaternionic unbounded normal operator to a quaternionic bounded normal operator. With this paper we complete the foundation of spectral analysis of quaternionic operators. The S-spectrum has been introduced to define the quaternionic functional calculus but it turns out to be the correct object also for the spectral theorem for quaternionic normal operators. The fact that the correct notion of …

Characterizations Of Rectangular (Para)-Unitary Rational Functions, Daniel Alpay, Palle Jorgensen, Izchak Lewkowicz

Mathematics, Physics, and Computer Science Faculty Articles and Research

We here present three characterizations of not necessarily causal, rational functions which are (co)-isometric on the unit circle:
(i) through the realization matrix of Schur stable systems,
(ii) the Blaschke-Potapov product, which is then employed to introduce an easy-to-use description of all these functions with dimensions and McMillan degree as parameters,
(iii) through the (not necessarily reducible) Matrix Fraction Description (MFD).
In cases (ii) and (iii) the poles of the rational functions involved may be anywhere in the complex plane, but the unit circle (including both zero and infinity). A special attention is devoted to exploring the gap between the …

The H∞ Functional Calculus Based On The S-Spectrum For Quaternionic Operators And For N-Tuples Of Noncommuting Operators, Daniel Alpay, Fabrizio Colombo, Tao Qian, Irene Sabadini, Tao Qian

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this paper we extend the H∞ functional calculus to quaternionic operators and to n-tuples of noncommuting operators using the theory of slice hyperholomorphic functions and the associated functional calculus, called S-functional calculus. The S-functional calculus has two versions one for quaternionic-valued functions and one for Clifford algebra-valued functions and can be considered the Riesz-Dunford functional calculus based on slice hyperholomorphicity because it shares with it the most important properties.

The S-functional calculus is based on the notion of S-spectrum which, in the case of quaternionic normal operators on a Hilbert space, is also the notion of spectrum that appears …

Wiener Algebra For The Quaternions, Daniel Alpay, Fabrizio Colombo, David P. Kimsey, Irene Sabadini

Mathematics, Physics, and Computer Science Faculty Articles and Research

We define and study the counterpart of the Wiener algebra in the quaternionic setting, both for the discrete and continuous case. We prove a Wiener-Lévy type theorem and a factorization theorem. We give applications to Toeplitz and Wiener-Hopf operators.

The Spectral Theorem For Unitary Operators Based On The S-Spectrum, Daniel Alpay, Fabrizio Colombo, David P. Kimsey, Irene Sabadini

Mathematics, Physics, and Computer Science Faculty Articles and Research

The quaternionic spectral theorem has already been considered in the literature, see e.g. [22], [31], [32], however, except for the finite dimensional case in which the notion of spectrum is associated to an eigenvalue problem, see [21], it is not specified which notion of spectrum underlies the theorem.

In this paper we prove the quaternionic spectral theorem for unitary operators using the S-spectrum. In the case of quaternionic matrices, the S-spectrum coincides with the right-spectrum and so our result recovers the well known theorem for matrices. The notion of S-spectrum is relatively new, see [17], and has been used for …

A New Realization Of Rational Functions, With Applications To Linear Combination Interpolation, Daniel Alpay, Palle Jorgensen, Izchak Lewkowicz, Dan Volok

Mathematics, Physics, and Computer Science Faculty Articles and Research

We introduce the following linear combination interpolation problem (LCI): Given N distinct numbers w1,…wN and N+1 complex numbers a1,…,aN and c, find all functions f(z) analytic in a simply connected set (depending on f) containing the points w1,…,wN such that ∑u=1Nauf(wu)=c. To this end we prove a representation theorem for such functions f in terms of an associated polynomial p(z). We first introduce the following two operations, (i) substitution of p, and (ii) multiplication by monomials zj,0≤j

Physical And Electrochemical Area Determination Of Electrodeposited Ni, Co, And Nico Thin Films, Matthew Gira, Kevin Tkacz, Jennifer R. Hampton

Faculty Publications

The surface area of electrodeposited thin films of Ni, Co, and NiCo was evaluated using electrochemical double-layer capacitance, electrochemical area measurements using the [Ru(NH₃)₆]³⁺/[Ru(NH₃)₆]²⁺ redox couple, and topographic atomic force microscopy (AFM) imaging. These three methods were compared to each other for each composition separately and for the entire set of samples regardless of composition. Double-layer capacitance measurements were found to be positively correlated to the roughness factors determined by AFM topography. Electrochemical area measurements were found to be less correlated with measured roughness factors as well as applicable …

Landmark Based Shape Analysis For Cerebellar Ataxia Classification And Cerebellar Atrophy Pattern Visualization, Zhen Yang, S. Mazdak Abulnaga, Aaron Carass, Bruno Jedynak, Chiadi U. Onyike, Jerry L. Prince, Multiple Additional Authors

Mathematics and Statistics Faculty Publications and Presentations

Cerebellar dysfunction can lead to a wide range of movement disorders. Studying the cerebellar atrophy pattern associated with different cerebellar disease types can potentially help in diagnosis, prognosis, and treatment planning. In this paper, we present a landmark based shape analysis pipeline to classify healthy control and different ataxia types and to visualize the characteristic cerebellar atrophy patterns associated with different types. A highly informative feature representation of the cerebellar structure is constructed by extracting dense homologous landmarks on the boundary surfaces of cerebellar sub-structures. A diagnosis group classifier based on this representation is built using partial least square dimension …

Investigating Alaskan Methane And Carbon Dioxide Fluxes Using Measurements From The Carve Tower, Anna Karion, Colm Sweeney Colm Sweeney, John B. Miller John B. Miller, Arlyn E. Andrews, Roisin Commane, Steven Dinardo, John M. Henderson, Jacob Lindaas, John C. Lin, Kristina Luus, Tim Newberger, Pieter Tans Pieter Tans, Steven C. Wofsy, Sonja Wolter, Charles E. Miller

Articles

Northern high-latitude carbon sources and sinks, including those resulting from degrading permafrost, are thought to be sensitive to the rapidly warming climate. Because the near-surface atmosphere integrates surface fluxes over large ( ∼ 500–1000 km) scales, atmospheric monitoring of carbon dioxide (CO2) and methane (CH4) mole fractions in the daytime mixed layer is a promising method for detecting change in the carbon cycle throughout boreal Alaska. Here we use CO2 and CH4 measurements from a NOAA tower 17 km north of Fairbanks, AK, established as part of NASA's Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE), to investigate regional fluxes of …

Variation In Summer Nitrogen And Phosphorus Uptake Among Siberian Headwater Streams, John D. Schade, Erin C. Seybold, Travis Drake, Seth Spawn, William V. Sobczak, Karen E. Frey, Robert M. Holmes, Nikita Zimov

Geography

Arctic streams are likely to receive increased inputs of dissolved nutrients and organic matter from thawing permafrost as climate warms. Documenting how Arctic streams process inorganic nutrients is necessary to understand mechanisms that regulate watershed fluxes of permafrost-derived materials to downstream ecosystems. We report on summer nitrogen (N) and phosphorus (P) uptake in streams draining upland soils from the Pleistocene, and lowland floodplain soils from the Holocene, in Siberia's Kolyma River watershed. Uptake of N and P differed between upland and floodplain streams, suggesting topographic variation in nutrient limitation. In floodplain streams, P uptake rate and uptake velocity were higher …

Regional Effects Of Streptozotocin-Induced Diabetes On Shortening And Calcium Transport In Epicardial And Endocardial Myocytes From Rat Left Ventricle, Manal M.A. Smaill, Muhammad A. Qureshi, Anatoliy Shmygol, Murat Oz, Jaipaul Singh, Vadym Sydorenko, Alya Arabi, Frank C. Howarth, Lina Al Kury

All Works

© 2016 The Authors. In the heart, the left ventricle pumps blood at higher pressure than the right ventricle. Within the left ventricle, the electromechanical properties of ventricular cardiac myocytes vary transmurally and this may be related to the gradients of stress and strain experienced in vivo across the ventricular wall. Diabetes is also associated with alterations in hemodynamic function. The aim of this study was to investigate shortening and Ca2+ transport in epicardial (EPI) and endocardial (ENDO) left ventricular myocytes in the streptozotocin (STZ)-induced diabetic rat. Shortening, intracellular Ca2+ and L-type Ca2+ current (ICa,L) were measured by video detection, …

Combining Weights Of Evidence Analysis With Feature Extraction - A Case Study From The Hauraki Goldfield, New Zealand, Leonardo Feltrin, João Gabriel Motta, Feras Al-Obeidat, Farhi Marir, Martina Bertelli

All Works

© 2016 The Authors. In this contribution we combine different image processing and pattern recognition methodologies to map the probability of discovering epithermal mineral deposits in the northern part of the Coromandel peninsula, in New Zealand. The objective of this work is to propose a case-study where the substitution of structural geology GIS themes (commonly developed by humans) with products derived by image processing, computer-based, semi-automatic edge detection analyses, is carried out to reduce subjective input in the prospectivity analysis. Semi-automated lineament extraction results introduced in the mineral favourability statistical modelling can more easily reveal unexpected potentially mineralised target domains, …