Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Chemistry (856)
- Environmental Sciences (754)
- Computer Sciences (735)
- Engineering (696)
- Physics (679)
-
- Mathematics (453)
- Life Sciences (450)
- Earth Sciences (423)
- Natural Resources and Conservation (357)
- Electrical and Computer Engineering (322)
- Optics (301)
- Statistics and Probability (286)
- Electromagnetics and Photonics (270)
- Oceanography and Atmospheric Sciences and Meteorology (215)
- Social and Behavioral Sciences (206)
- Geology (152)
- Applied Mathematics (139)
- Organic Chemistry (139)
- Ecology and Evolutionary Biology (131)
- Analytical Chemistry (122)
- Artificial Intelligence and Robotics (115)
- Natural Resources Management and Policy (107)
- Animal Sciences (105)
- Oceanography (105)
- Water Resource Management (104)
- Climate (76)
- Discrete Mathematics and Combinatorics (73)
- Geography (72)
- Applied Statistics (70)
- Institution
- Keyword
-
- Daniel Felix Ritchie School of Engineering and Computer Science (83)
- Machine learning (65)
- College of Natual Science and Mathematics (62)
- Chemistry and Biochemistry (50)
- ETD (48)
-
- Computer Science (41)
- Graph theory (39)
- Mathematics (39)
- College of Natural Science and Mathematics (38)
- Morgridge College of Education (37)
- Climate change (34)
- Research Methods and Information Science (33)
- Research Methods and Statistics (32)
- Physics and Astronomy (29)
- Nanoparticles (27)
- Machine Learning (24)
- Remote sensing (23)
- Artificial intelligence (22)
- Catalysis (21)
- Geographic information systems (20)
- Simulation (20)
- Statistics (20)
- Chemistry (19)
- Optics (19)
- Nonlinear optics (18)
- Computer vision (17)
- Deep learning (16)
- Domination (15)
- GIS (15)
- Geology (15)
- Publication Year
- File Type
Articles 1831 - 1860 of 4195
Full-Text Articles in Physical Sciences and Mathematics
The Physical Properties And Composition Of Main-Belt Asteroids From Infrared Spectroscopy, Zoe Landsman
The Physical Properties And Composition Of Main-Belt Asteroids From Infrared Spectroscopy, Zoe Landsman
Electronic Theses and Dissertations
Asteroids are the remnants of planet formation, and as such, they represent a record of the physical and chemical conditions in the early solar system and its evolution over the past 4.6 billion years. Asteroids are relatively accessible by spacecraft, and thus may be a source of the raw materials necessary for future human exploration and settlement of space. Those on Earth-crossing orbits pose impact hazards for which mitigation strategies must be developed. For these reasons, several missions to asteroids are in progress or planned with the support of the National Aeronautics and Space Administration (NASA) and other national space …
Noise, Stability, And Linewidth Performance Of 10-Ghz Optical Frequency Combs Generated From The Nested Cavity Architecture, Kristina Bagnell
Noise, Stability, And Linewidth Performance Of 10-Ghz Optical Frequency Combs Generated From The Nested Cavity Architecture, Kristina Bagnell
Electronic Theses and Dissertations
Optical frequency combs with wide mode spacing and low timing jitter are relied upon for both time domain and frequency domain applications. It has been previously demonstrated that surrounding a low-Q semiconductor laser chip with a long external fiber cavity and inserting a high finesse Fabry–Pérot etalon into this cavity can produce a mode-locked laser with the desired high repetition rate and narrow optical mode linewidths which are of benefit to applications like photonic analog-to-digital conversion and astronomical spectrograph calibration. With this nested cavity architecture, the quality factor of the resonator is effectively determined by the product of the individual …
Reproductive Life History And Signal Evolution In A Multi-Species Assemblage Of Electric Fish, Joseph Waddell
Reproductive Life History And Signal Evolution In A Multi-Species Assemblage Of Electric Fish, Joseph Waddell
Electronic Theses and Dissertations
Animals that co-occur in sympatry with multiple closely-related species use reproductive mate attraction signals not only to assess the quality of a potential conspecific mate (sexual selection), but also to discriminate conspecifics from heterospecifics (species recognition). However, the extent to which sexual selection and species recognition may interact, or even conflict, is poorly known. Neotropical electric fish offer unrivaled opportunities for understanding this problem. They generate simple, stereotyped mate attraction signals that are easy to record and quantify, and that are well-understood from the neurobiological perspective. Additionally, they live in electrically-crowded environments, where multiple congeners live and reproduce in close …
Complex Affect Recognition In The Wild, Behnaz Nojavanasghari
Complex Affect Recognition In The Wild, Behnaz Nojavanasghari
Electronic Theses and Dissertations
Artificial social intelligence is a step towards human-like human-computer interaction. One important milestone towards building socially intelligent systems is enabling computers with the ability to process and interpret the social signals of humans in the real world. Social signals include a wide range of emotional responses from a simple smile to expressions of complex affects. This dissertation revolves around computational models for social signal processing in the wild, using multimodal signals with an emphasis on the visual modality. We primarily focus on complex affect recognition with a strong interest in curiosity. In this dissertation,we ?rst present our collected dataset, EmoReact. …
Computational Approach To Electrocatalysis, Nagendra Dhakal
Computational Approach To Electrocatalysis, Nagendra Dhakal
Electronic Theses and Dissertations
The main objective of this work is to understand the theoretical basis of the working principle of the Hydrogen fuel cell. We seek the physical basis of the Rational Design Technique, the smart way of preselecting materials from the material-pool, implemented in our study anticipating highly promising electrocatalysts for promoting the conversion of chemical energy stored in hydrogen molecules into the electrical energy. It needs the understanding of the relationship among the compositions of the materials under consideration, their electronic structure and catalytic activities. We performed the first principle DFT calculations to achieve the goal. Our work is focused first …
Enhancement Of Bandwidth And Laser Deflection Angle Of Acousto-Optic Deflectors By Dynamic Two-Dimensional Refractive Index Modulation, Tiansi Wang
Electronic Theses and Dissertations
Acousto-Optic Deflectors (AODs) are inertialess optical solid state devices that have advantages over conventional mechanically controlled mirror-based deflectors in numerous scientific and industrial applications. These applications include fluorescence microscopy, sensing, variable-focus lens, photolithography and laser materials processing. AODs are currently operated with a single piezoelectric transducer that modulates the refractive index only in one direction. This operating principle limits the performance of AODs to a narrow acoustic bandwidth of the transducer and a small angle of laser deflection governed by the Bragg diffraction. To overcome these two limitations, the operation of AODs with phased array ultrasonic transducers is analyzed in …
The Role Of The Y-Chromosome In The Evolution Of Autosomally Coded Traits, Ian Kutch
The Role Of The Y-Chromosome In The Evolution Of Autosomally Coded Traits, Ian Kutch
Electronic Theses and Dissertations
Recent work indicates that the Y-chromosome of the fruit fly Drosophila melanogaster can influence gene regulation on the autosomes and X chromosome. This newly discovered function of the Y has the potential to dramatically shape the regulatory evolution of numerous genes that reside throughout the genome; even for genes that code for both male and female traits. Given that the mechanism underlying the Y-linked influence on gene expression in D. melanogaster appears to exist in other independently evolved heterogametic sex chromosomes, the evolutionary implications of Y-linked regulatory variation (YRV) deserves to be explored. These implications include the potential for Y-chromosomes …
Filtering Problems In Stochastic Tomography, Tyler Gomez
Filtering Problems In Stochastic Tomography, Tyler Gomez
Electronic Theses and Dissertations
Distinguishing signal from noise has always been a major goal in probabilistic analysis of data. Such is no less the case in the field of medical imaging, where both the processes of photon emission and their rate of absorption by the body behave as random variables. We explore methods by which to extricate solid conclusions from noisy data involving an X-ray transform, long the mathematical mainstay of such tools as computed axial tomography (CAT scans). Working on the assumption of having some prior probabilities assigned to various states a body can be found in, we introduce and make rigorous an …
Mountain Lion (Puma Concolor) Population Characteristics And Resource Selection In The North Dakota Badlands, Randy D. Johnson
Mountain Lion (Puma Concolor) Population Characteristics And Resource Selection In The North Dakota Badlands, Randy D. Johnson
Electronic Theses and Dissertations
Mountain lions (Puma concolor) have significant ecological impacts on the ecosystems they inhabit, leading to both biological and social ramifications. Yet, due to the relatively recent natural recolonization by mountain lions of the Little Missouri Badlands Region of western North Dakota, detailed data regarding many aspects of this population have been lacking. Therefore, we studied mountain lions occupying the Badlands Region to improve our understanding of mountain lion population ecology, resource selection, and occurrence in North Dakota. Our objectives were to: 1) improve the accuracy of home range size, subadult movement, and survival estimates of mountain lions in …
Smart Image Search System Using Personalized Semantic Search Method, Fangyu Zhang
Smart Image Search System Using Personalized Semantic Search Method, Fangyu Zhang
Electronic Theses and Dissertations
Due to the emerge in huge numbers of information on the internet nowadays, search technologies are widely used in various fields. Achieving the most relevant search result for the users becomes a big challenge now. While the traditional semantic search technologies seem to achieve the most relevant search result, however, it faces two problems: one is the one-size-fits-all problem, and another is low efficiency. The purpose of this research is to build a Smart Image Search System by using the personalized semantic search method to solve those problems. The personalized semantic search method makes the search system avoids the one-size-fits-all …
Designer Metasurfaces For On Demand Optical Responses, Matthew S. Lepain
Designer Metasurfaces For On Demand Optical Responses, Matthew S. Lepain
Electronic Theses and Dissertations
Nanostructured materials are one of the leading areas in photonics currently. These structures offer almost limitless possibilities in the manipulation of light. Using two different semi-analytical simulation methods, I show a few of the possible properties that these nanostructures possess, including polarization rotation and coupling with electronics.
Quasi-Random Action Selection In Markov Decision Processes, Samuel D. Walker
Quasi-Random Action Selection In Markov Decision Processes, Samuel D. Walker
Electronic Theses and Dissertations
In Markov decision processes an operator exploits known data regarding the environment it inhabits. The information exploited is learned from random exploration of the state-action space. This paper proposes to optimize exploration through the implementation of quasi-random sequences in both discrete and continuous state-action spaces. For the discrete case a permutation is applied to the indices of the action space to avoid repetitive behavior. In the continuous case sequences of low discrepancy, such as Halton sequences, are utilized to disperse the actions more uniformly.
Modeling Volatility Of Financial Time Series Using Arc Length, Benjamin H. Hoerlein
Modeling Volatility Of Financial Time Series Using Arc Length, Benjamin H. Hoerlein
Electronic Theses and Dissertations
This thesis explores how arc length can be modeled and used to measure the risk involved with a financial time series. Having arc length as a measure of volatility can help an investor in sorting which stocks are safer/riskier to invest in. A Gamma autoregressive model of order one(GAR(1)) is proposed to model arc length series. Kernel regression based bias correction is studied when model parameters are estimated using method of moment procedure. As an application, a model-based clustering involving thirty different stocks is presented using k-means++ and hierarchical clustering techniques.
A Journey To Fuzzy Rings, Brett T. Ernst
A Journey To Fuzzy Rings, Brett T. Ernst
Electronic Theses and Dissertations
Enumerative geometry is a very old branch of algebraic geometry. In this thesis, we will describe several classical problems in enumerative geometry and their solutions in order to motivate the introduction of tropical geometry. Finally, fuzzy rings, a powerful algebraic framework for tropical and algebraic geometry is introduced.
Development Of Computational Techniques For Regulatory Dna Motif Identification Based On Big Biological Data, Jinyu Yang
Development Of Computational Techniques For Regulatory Dna Motif Identification Based On Big Biological Data, Jinyu Yang
Electronic Theses and Dissertations
Accurate regulatory DNA motif (or motif) identification plays a fundamental role in the elucidation of transcriptional regulatory mechanisms in a cell and can strongly support the regulatory network construction for both prokaryotic and eukaryotic organisms. Next-generation sequencing techniques generate a huge amount of biological data for motif identification. Specifically, Chromatin Immunoprecipitation followed by high throughput DNA sequencing (ChIP-seq) enables researchers to identify motifs on a genome scale. Recently, technological improvements have allowed for DNA structural information to be obtained in a high-throughput manner, which can provide four DNA shape features. The DNA shape has been found as a complementary factor …
Enhanced Breast Cancer Classification With Automatic Thresholding Using Support Vector Machine And Harris Corner Detection, Mohammad Taheri
Enhanced Breast Cancer Classification With Automatic Thresholding Using Support Vector Machine And Harris Corner Detection, Mohammad Taheri
Electronic Theses and Dissertations
Image classification and extracting the characteristics of a tumor are the powerful tools in medical science. In case of breast cancer medical treatment, the breast cancer classification methods can be used to classify input images as benign and malignant classes for better diagnoses and earlier detection with breast tumors. However, classification process can be challenging because of the existence of noise in the images, and complicated structures of the image. Manual classification of the images is timeconsuming, and need to be done only by medical experts. Hence using an automated medical image classification tool is useful and necessary. In addition, …
Improving Survey Methodology To Monitor Rare Grassland Birds In South Dakota, Kassondra Hendricks
Improving Survey Methodology To Monitor Rare Grassland Birds In South Dakota, Kassondra Hendricks
Electronic Theses and Dissertations
Breeding Bird Survey (BBS) data for grassland bird species has shown the most rapid population decline of any other bird group. Current roadside survey techniques, however, may fall short of providing accurate numbers of rare grassland bird species such as chestnut-collared longspur (Calcarius ornatus), lark bunting (Calamospiza melanocorys), Sprague’s pipit (Anthus spragueii), and Baird’s sparrow (Ammodramus bairdii). Trends resulting from roadside data for grassland birds are oftentimes determined to be statistically insignificant because many grassland bird species occur on too few routes, occur in low numbers per route, and show high annual fluctuations in number. It is possible roadside surveys …
Human Dimensions Of Habitat Loss In The Plains And Prairie Potholes Ecoregion, Lily A. Sweikert
Human Dimensions Of Habitat Loss In The Plains And Prairie Potholes Ecoregion, Lily A. Sweikert
Electronic Theses and Dissertations
The Plains and Prairie Potholes Ecoregion (PPPE), is located in the north-central contiguous United States and is one of the most imperiled grassland regions in the world. Most of the region is privately owned and used for the production of agricultural commodities. In addition to its direct benefits to humanity, the PPPE provides multiple ecosystem services including, soil and water quality improvements, carbon sequestration, weather amelioration, and wildlife habitat. Recent increases in expansion of row crop agriculture concerns conservation practitioners about the long-term integrity of the PPPE. Conservation practitioners are looking to improve their private landowner conservation initiatives in the …
Modeling Streamflow And Water Quality Impacts Of Grassland Establishment, Conversion, And Management In Skunk Creek Watershed, Jiyeong Hong
Modeling Streamflow And Water Quality Impacts Of Grassland Establishment, Conversion, And Management In Skunk Creek Watershed, Jiyeong Hong
Electronic Theses and Dissertations
Grassland is a valuable natural resource with many environmental benefits, which include erosion control, wildlife habitat promotion, water quality protection, and flood prevention. Conversion of grassland to cultivated cropland has been linked to environmental quality concerns. The goal of this study was to model the impacts of grassland establishment, depletion, and management on hydrology and water quality in Skunk Creek watershed in eastern South Dakota. The specific objectives are to quantify the impacts of grassland conversion and selected management regimes on streamflow and water quality, and explore the optimum grassland establishment location within a watershed to achieve water quality benefits. …
Approximate Statistical Solutions To The Forensic Identification Of Source Problem, Danica M. Ommen
Approximate Statistical Solutions To The Forensic Identification Of Source Problem, Danica M. Ommen
Electronic Theses and Dissertations
Currently in forensic science, the statistical methods for solving the identification of source problems are inherently subjective and generally ad-hoc. The formal Bayesian decision framework provides the most statistically rigorous foundation for these problems to date. However, computing a solution under this framework, which relies on a Bayes Factor, tends to be computationally intensive and highly sensitive to the subjective choice of prior distributions for the parameters. Therefore, this dissertation aims to develop statistical solutions to the forensic identification of source problems which are less subjective, but which retain the statistical rigor of the Bayesian solution. First, this dissertation focuses …
U-Statistics For Characterizing Forensic Sufficiency Studies, Cami Fuglsby
U-Statistics For Characterizing Forensic Sufficiency Studies, Cami Fuglsby
Electronic Theses and Dissertations
One of the main metrics for deciding if a given forensic modality is useful across a broad spectrum of cases, within a given population, is the Random Match Probability (RMP), or the corresponding discriminating power. Traditionally, the RMP of a given modality is studied by comparing full `templates' and estimating the rate at which pairs of templates 'match' in a given population. This strategy leads to a natural U-statistic of degree two. However, in questioned document examination, the RMP is studied as a function of the amount of handwriting contained in the two documents being compared; turning the U-statistic into …
Identifying Predictors Of Weight Loss And Drop-Out Using Joint Modeling, Valerie Bares
Identifying Predictors Of Weight Loss And Drop-Out Using Joint Modeling, Valerie Bares
Electronic Theses and Dissertations
Profile by Sanford is a membership based weight loss program that helps its members make lifestyle changes with diet, exercise, and one-on-one interactions with a weight loss coach. Discovery of characteristics and behaviors influencing weight loss will benefit current and future members of Profile. This research utilizes massive data from Profile by Sanford to analyze member behavior. Fourteen data sets are evaluated, some containing millions of observations. All data is combined into one comprehensive table of 33,487 members. Members of Profile by Sanford are 77% female and two-thirds of all members start the program classified as obese. Attending meetings with …
On Zero-Sum Rado Numbers For The Equation Ax_1 + X_2 = X_3, Nicholas Brown
On Zero-Sum Rado Numbers For The Equation Ax_1 + X_2 = X_3, Nicholas Brown
Electronic Theses and Dissertations
For every positive integer $a$, let $n = R_{ZS}(a)$ be the least integer, provided it exists, such that for every coloring \[ \Delta : \{1, 2, ..., n\} \rightarrow \{0, 1, 2\},\] there exist three integers $x_1, x_2, x_3$ (not necessarily distinct) such that \[ \Delta(x_1) + \Delta(x_2) + \Delta(x_3) \equiv 0\ (mod\ 3) \] and \[ ax_1 +x_2 = x_3.\] If such an integer does not exist, then $R_{ZS}(a) = \infty.$ The main results of this paper are \[R_{ZS}(2) = 12\] and a lower bound is found for $R_{ZS}(a)$ where $a \geq 2$.
Threshold Models For Genome-Wide Association Mapping Of Familial Breast Cancer Incidence In Humans, Nasir Elmesmari
Threshold Models For Genome-Wide Association Mapping Of Familial Breast Cancer Incidence In Humans, Nasir Elmesmari
Electronic Theses and Dissertations
Breast cancer is the second most fatal cancer in the world and one of the most highly harmful cancers from which people suffer. Breast cancer studies have been able to uncover some knowledge about genetic susceptibility for familial breast cancer in humans. Hence, determining genetic factors may potentially help track the disease, as well as discover the cancer in early stages, or perhaps before it starts. In addition, this may allow early determination of possible treatment strategies which will make it easier to prevent the disease. In this context, it is important to determine whether the heritability of breast cancer …
Measuring Aquatic Organism Responses To Grassland Restoration: Does The Field Of Dreams Really Exist?, David A. Schumann
Measuring Aquatic Organism Responses To Grassland Restoration: Does The Field Of Dreams Really Exist?, David A. Schumann
Electronic Theses and Dissertations
Landscape homogenization and the degradation of riparian areas has greatly impaired stream ecosystems throughout North America. Conservation programs may repair riparian ecosystems to indirectly improve water quality and instream habitat heterogeneity in hopes to elicit biological responses. However, focused manipulations on isolated stream fragments have rarely achieved biological goals. Prairie streams with restored riparian areas were appraised (chemical, physical, and biological variables) to quantify the indirect effects of prevalent grassland conservation practices on aquatic resources. Riparian rehabilitation, via passive methods, promoted bank-stabilizing vegetation along all conservation stream reaches. Riparian vegetation and function quickly recovered from previous agricultural disturbances at conservation …
Simulation Of Magnetically Confined Inductively Coupled Plasma, Sina Javadpour
Simulation Of Magnetically Confined Inductively Coupled Plasma, Sina Javadpour
Electronic Theses and Dissertations
In this work, a new parallel coil design was presented to address the need for high density inductively coupled plasmas with enhanced properties and a more uniform and consistent distribution, suitable for large-area material processing. Fluid model simulations of 3D argon inductively coupled plasma (ICP) were performed in COMSOL for the proposed coil and a conventional single cylindrical coil with the same impedance to be used as reference, to compare and evaluate the performance of this new halftoroidal parallel coil design and study its effects on the main variables of the generated plasma. Through different comparisons of the simulations results, …
Deep Eutectic Solvents Synthesis, Characterization And Applications In Pretreatment Of Lignocellulosic Biomass, Ganesh Degam
Deep Eutectic Solvents Synthesis, Characterization And Applications In Pretreatment Of Lignocellulosic Biomass, Ganesh Degam
Electronic Theses and Dissertations
There has been an increased interest in green solvents and biofuels with the growing environmental awareness across the globe. Conventional methods of biofuel production involve the use of large quantities of molecular solvents and ionic liquids (ILs), but they have the drawbacks of high vapor pressure (organic solvents), toxicity, and recyclability in terms of a sustainability point of view. Deep eutectic solvents (DESs) have recently emerged as green alternatives to molecular solvents and ionic liquids (ILs). They are defined as eutectic mixtures formed between quaternary ammonium, phosphonium or sulfonium salts and hydrogen bond donors (HBDs) with the freezing temperature lower …
Response Surface Methodology And Its Application In Optimizing The Efficiency Of Organic Solar Cells, Rajab Suliman
Response Surface Methodology And Its Application In Optimizing The Efficiency Of Organic Solar Cells, Rajab Suliman
Electronic Theses and Dissertations
Response surface methodology (RSM) is a ubiquitous optimization approach used in a wide variety of scientific research studies. The philosophy behind a response surface method is to sequentially run relatively simple experiments or models in order to optimize a response variable of interest. In other words, we run a small number of experiments sequentially that can provide a large amount of information upon augmentation. In this dissertation, the RSM technique is utilized in order to find the optimum fabrication condition of a polymer solar cell that maximizes the cell efficiency. The optimal device performance was achieved using 10.25 mg/ml polymer …
Mechanistic Insights Into The Radical S-Adenosyl L-Methionine Enzyme Mftc, Bulat Khaliullin
Mechanistic Insights Into The Radical S-Adenosyl L-Methionine Enzyme Mftc, Bulat Khaliullin
Electronic Theses and Dissertations
Mycofactocin is a putative peptide-derived redox cofactor in Mycobacterium family. Its putative biosynthetic pathway is encoded by the operon mftABCDEF. The initial step of this pathway is a posttranslational modification of a peptide precursor MftA, which is catalyzed by MftC enzyme. This modification only occurs in the presence of chaperone MftB. Here, we demonstrate that MftC is a radical S-adenosyl L-methionine (SAM) enzyme and we examine its catalytic mechanism. We show that the modification of MftA requires two equivalents of SAM and is implemented in two steps: (i) the decarboxylation of a C-terminal tyrosine, resulting in formation of an …
Implementation Of Refining Statements In Openjml And Verification Of Higher Order Methods With Model Program Specifications, Sai Chandesh Gurramkonda
Implementation Of Refining Statements In Openjml And Verification Of Higher Order Methods With Model Program Specifications, Sai Chandesh Gurramkonda
Electronic Theses and Dissertations
The Java Modeling Language (JML) describes the functional behavior of Java classes and methods using pre- and postconditions. However, standard pre- and postcondition specifications cannot verify calls to higher order methods (HOMs). JML uses model program specifications to reason about HOMs. This thesis describes the implementation of model programs in the OpenJML tool. The implementation includes parsing, type checking, and matching of model program specifications against the code.