Digital Commons Network^™

Teddi: Tamper Event Detection On Distributed Cyber-Physical Systems, Jason O. Reeves

Dartmouth College Ph.D Dissertations

Edge devices, or embedded devices installed along the periphery of a power grid SCADA network, pose a significant threat to the grid, as they give attackers a convenient entry point to access and cause damage to other essential equipment in substations and control centers. Grid defenders would like to protect these edge devices from being accessed and tampered with, but they are hindered by the grid defender's dilemma; more specifically, the range and nature of tamper events faced by the grid (particularly distributed events), the prioritization of grid availability, the high costs of improper responses, and the resource constraints of …

Constraint-Based Robot Knot Tying, Weifu Wang

Dartmouth College Ph.D Dissertations

In this thesis, we present different approaches to tying knots using robots by enforcing different types of constraints. We attack the problem from three different directions; mechanical design, motion planning with simple control strategies, and theoretical analysis. We present the first complete generalized fixture based knot tying approach that is able to arrange and tighten knots, building on Matthew Bell’s work on arranging simple knots using fixtures [Bel10]. Physical constraints are provided by these fixtures to reduce the possible string deformation during knot tying. Fixtures are designed automatically using proposed design principles, and constructed based on the designs using 3D …

Optical Tracking And Spectral Characterization Of Cubesats For Operational Missions, Forrest Gasdia

Doctoral Dissertations and Master's Theses

Orbital debris in low Earth orbit is of growing concern to operational satellites from the government and commercial sector. With an uptick in worldwide satellite launches and the growing adoption of the CubeSat standard, the number of small objects in orbit are increasing at a faster pace than ever. As a result, a cascading collision event seems inevitable in the near future.

The United States Strategic Command tracks and determines the orbit of resident space objects using a worldwide network of radar and optical sensors. However, in order to better protect space assets, there has been increased interest in not …

Vibration Analysis Of A Composite Wing Box With Arbitrarily Shaped Spars And Ribs, Rossana R. Fernandes

Doctoral Dissertations and Master's Theses

In this research, the free vibration analysis of composite wing boxes with curvilinear spars and ribs is performed. Modern manufacturing technologies, such as Electron Beam Freeform Fabrication and Friction Stir Welding, have allowed the manufacturing of arbitrarily shaped stiffeners. Curvilinear stiffeners provide flexibility in design as they can assume an infinite number of paths. Curvilinear spars and ribs can in some instances provide a better vibration and static response than their straight counterparts while reducing the overall mass of the structure. An equivalent continuum plate model of a wing box using energy formulations is proposed at the preliminary design stage …

Magneto-Rheological Fluid Device As Artificial Feel Force System On Aircraft Control Stick, Vignesh Manoharan

Doctoral Dissertations and Master's Theses

The conventional feel system in any aircraft occupies large space in the cockpit and has complicated designs. The primary objective of this research is to develop an artificial feel force system that can overcome some drawbacks of the current feel force system. A novel feel system using magneto-rheological (MR) fluid is constructed to precisely control the shear stress under the magnetic field. To validate the functionality of the MR artificial feel system, the final system is fabricated and multiple tests are performed to acquire force-velocity characteristics that are compared to the mathematical model derived. In addition, the reference model of …

Features And Algorithms For Visual Parsing Of Handwritten Mathematical Expressions, Lei Hu

Theses

Math expressions are an essential part of scientific documents. Handwritten math expressions recognition can benefit human-computer interaction especially in the education domain and is a critical part of document recognition and analysis.

Parsing the spatial arrangement of symbols is an essential part of math expression recognition. A variety of parsing techniques have been developed during the past three decades, and fall into two groups. The first group is graph-based parsing. It selects a path or sub-graph which obeys some rule to form a possible interpretation for the given expression. The second group is grammar driven parsing. Grammars and related parameters …

Image Description Using Deep Neural Networks, Ram Manohar Oruganti

Theses

Current research in computer vision and machine learning has demonstrated some great abilities at detecting and recognizing objects in natural images. Current state-of-the-art results in object detection, classification and localization in ImageNet Challenges have the validation accuracy for top 5 predictions for classification to be at 3.08% while similar classification experiments run by trained humans report an accuracy of 5.1%. While some people might argue that human accuracy is a function of training time it can be said with great confidence that automated classification models are at least as good as trained humans in classification problems. The ability of these …

Validating Color Doppler Ultrasound Performance Via A Quantitative Comparison With Particle Image Velocimetry, Allan Alexander Andranikian

Theses

Color Doppler Ultrasound (CDUS) is a method of non-invasive fluid velocity measurement that is used for regular cardiac screenings as well as during complex surgeries such as valve replacements. A Color Doppler image is a contour map of the velocity field and can thereby indicate the presence of abnormal flows or be used to quantitatively measure velocities. CDUS is inexpensive and completely non-invasive. It is for these same reasons that CDUS has the potential to be a powerful tool not only in the medical field, but in the industrial and engineering research fields as well. While there are many devices …

Sampling And Counting Crossing-Free Matchings, Wenbo Sun

Theses

Sampling of combinatorial structures is an important statistical tool used in applications in a number of areas ranging from statistical physics, data mining, to biological sciences. Of comparable importance is the computation of the cor- responding partition function, which, in the case of the uniform distribution, is equivalent to the problem of counting all such structures. For self-reducible combinatorial structures, once we can produce an almost uniform sample from them, then we can approximately count them.

Using a Markov chain Monte Carlo method, this thesis presents polynomial-time algorithms to approximately count and almost uniformly sample crossing-free matchings for certain input …

A Scalable Flash-Based Hardware Architecture For The Hierarchical Temporal Memory Spatial Pooler, Lennard G. Streat

Theses

Hierarchical temporal memory (HTM) is a biomimetic machine learning algorithm focused upon modeling the structural and algorithmic properties of the neocortex. It is comprised of two components, realizing pattern recognition of spatial and temporal data, respectively. HTM research has gained momentum in recent years, leading to both hardware and software exploration of its algorithmic formulation. Previous work on HTM has centered on addressing performance concerns; however, the memory-bound operation of HTM presents significant challenges to scalability.

In this work, a scalable flash-based storage processor unit, Flash-HTM (FHTM), is presented along with a detailed analysis of its potential scalability. FHTM leverages …

Random Subspace Learning On Outlier Detection And Classification With Minimum Covariance Determinant Estimator, Bohan Liu

Theses

The questions brought by high dimensional data is interesting and challenging. Our study is targeting on the particular type of data in this situation that namely “large p, small n”. Since the dimensionality is massively larger than the number of observations in the data, any measurement of covariance and its inverse will be miserably affected. The definition of high dimension in statistics has been changed throughout decades. Modern datasets with over thousands of dimensions are demanding the ability to gain deeper understanding but hindered by the curse of dimensionality. We decide to review and explore further to negotiate with the …

Structuring Statistical Tests For Validating Encryption: An Array-Based Approach, Kevin Hoyt

Theses

The technological advancements made in recent years regarding the transfer of personal data have brought along an imperative need for increased security and encryption capabilities. Information sent across these electronic platforms is most often intended to be delivered to and received by specific individuals. However, the notion that these selected individuals are the only people that are able to come into contact with the information is flawed. A more realistic assumption, and the assumption that is currently demonstrated, is that the information sent can and will be intercepted. This means that successful encryption of the data is an invaluable part …

Low-Resource And Fast Elliptic Curve Implementations Over Binary Edwards Curves, Brian Koziel

Theses

Elliptic curve cryptography (ECC) is an ideal choice for low-resource applications because it provides the same level of security with smaller key sizes than other existing public key encryption schemes. For low-resource applications, designing efficient functional units for elliptic curve computations over binary fields results in an effective platform for an embedded co-processor. This thesis investigates co-processor designs for area-constrained devices. Particularly, we discuss an implementation utilizing state of the art binary Edwards curve equations over mixed point addition and doubling. The binary Edwards curve offers the security advantage that it is complete and is, therefore, immune to the exceptional …

Phenotypic Studies Of Pho13Δ In Saccharomyces Cerevisiae, Courtney Kellogg

Theses

PHO13 in Saccharomyces cerevisiae (budding yeast) is a para-nitrophenyl phosphatase (pNppase) of the haloacid dehalogenase (HAD) superfamily. A biological substrate for PHO13 had remained undiscovered while a knockout phenotype has only been observed in strains engineered to grow on D-xylose. The purified enzyme has been identified in our lab to specifically hydrolyze 2-phosphoglycolate, classifying it as a phosphoglycolate phosphatase (PGPase). In photosynthetic organisms, 2-phosphoglycolate (2-PG) is generated by the oxygenation reaction of ribulose-1,5-bisphosphate carboxylase (RuBisCO) in the Calvin Cycle. To be recycled back into general metabolism, photosynthetic PGPase converts 2-PG to glycolate. In non-photosynthetic yeast, 2-PG must be generated by …

Fusion Of Mini-Deep Nets, Sai Prasad Nooka

Theses

Image classification and object recognition are some of the most prominent problems in computer vision. The difficult nature of finding objects regardless of pose and occlusions requires a large number of compute resources. Recent advancements in technology have made great strides towards solving this problem, and in particular, deep learning has revolutionized this field in the last few years.

The classification of large datasets, such as the popular ImageNet dataset, requires a network with millions of weights. Learning each of these weights using back propagation requires a compute intensive training phase with many training samples. Recent compute technology has proven …

Synthesis, Characterization, And Electronic Properties Of Novel 2d Materials : Transition Metal Dichalcogenides And Phosphorene., George Anderson

Electronic Theses and Dissertations

Scaling electronic devices has become paramount. The current work builds upon scaling efforts by developing novel synthesis methods and next generation sensing devices based on 2D materials. A new combination method utilizing thermal evaporation and chemical vapor deposition was developed and analyzed to show the possibilities of Transition Metal Dichalcogenide monolayers and heterostructures. The materials produced from the above process showed high degrees of compositional control in both spatial dimensions and chemical structure. Characterization shows controlled fabrication of heterostructures, which may pave the way for future band gap engineering possibilities. In addition, Phosphorene based field effect transistors, photodetectors, and gas …

A Log Rank Test For Clustered Data Under Informative Within-Cluster Group Size., Mary Elizabeth Gregg

Electronic Theses and Dissertations

The log rank test is a popular nonparametric test for comparing the marginal survival distribution of two groups. When data are organized within clusters and the size of clusters or the distribution of group membership within a cluster is related to an outcome of interest, traditional methods of data analysis can be biased. In this thesis, we develop a within-cluster group weighted log rank test to compare marginal survival time distributions between groups from clustered data, correcting for cluster size and intra-cluster group size informativeness. The performance of this new test is compared with the unweighted and cluster-weighted log rank …

Integrated Analysis Of Mirna/Mrna Expression And Gene Methylation Using Sparse Canonical Correlation Analysis., Dake Yang

Electronic Theses and Dissertations

MicroRNAs (miRNAs) are a large number of small endogenous non-coding RNA molecules (18-25 nucleotides in length) which regulate expression of genes post-transcriptionally. While a variety of algorithms exist for determining the targets of miRNAs, they are generally based on sequence information and frequently produce lists consisting of thousands of genes. Canonical correlation analysis (CCA) is a multivariate statistical method that can be used to find linear relationships between two data sets, and here we apply CCA to find the linear combination of differentially expressed miRNAs and their corresponding target genes having maximal negative correlation. Due to the high dimensionality, sparse …

Investigating The Influences Of Climate On The High Elevation Snowpack Hydrology In The Upper Colorado Region., Claire-Louise Bode

Electronic Theses and Dissertations

A change in climate in the western United States has already affected and will continue to affect the onset of snow melt in many parts of the country. The effect of climate change on snow water equivalent, snowmelt runoff and total streamflow with respect to their elevation distribution is examined across the Colorado Headwaters Basin. This is a high altitude location within the Upper Colorado Basin region. The total streamflow of this region has a significant contribution from the spring season snow melt. An increase in air temperature in the Colorado Headwaters Basin over a few years will change the …

Operational Decision Making For Medical Clinics Through The Use Of Simulation And Multi-Attribute Utility Theory., Bo Sun

Electronic Theses and Dissertations

Currently, health care is a large industry that concerns everyone. Outpatient health care is an important part of the American health care system and is one of the strongest growth areas in the health care system. Many people pay attention to how to keep basic health care available to as many people as possible. A large health care system is usually evaluated by many performance measures. For example, the managers of a medical clinic are concerned about increasing staff utilization; both managers and patients are concerned about patient waiting time. In this dissertation, we study decision making for clinics in …

Sparse Feature Learning For Image Analysis In Segmentation, Classification, And Disease Diagnosis., Ehsan Hosseini-Asl

Electronic Theses and Dissertations

The success of machine learning algorithms generally depends on intermediate data representation, called features that disentangle the hidden factors of variation in data. Moreover, machine learning models are required to be generalized, in order to reduce the specificity or bias toward the training dataset. Unsupervised feature learning is useful in taking advantage of large amount of unlabeled data, which is available to capture these variations. However, learned features are required to capture variational patterns in data space. In this dissertation, unsupervised feature learning with sparsity is investigated for sparse and local feature extraction with application to lung segmentation, interpretable deep …

Semi-Parametric Methods For Personalized Treatment Selection And Multi-State Models., Chathura K. Siriwardhana

Electronic Theses and Dissertations

This dissertation contains three research projects on personalized medicine and a project on multi-state modelling. The idea behind personalized medicine is selecting the best treatment that maximizes interested clinical outcomes of an individual based on his or her genetic and genomic information. We propose a method for treatment assignment based on individual covariate information for a patient. Our method covers more than two treatments and it can be applied with a broad set of models and it has very desirable large sample properties. An empirical study using simulations and a real data analysis show the applicability of the proposed procedure. …

Production And Inventory Control In Complex Production Systems Using Approximate Dynamic Programming., Han Wu

Electronic Theses and Dissertations

Production systems focus not only on providing enough product to supply the market, but also on delivering the right product at the right price, while lowering the cost during the production process. The dynamics and uncertainties of modern production systems and the requirements of fast response often make its design and operation very complex. Thus, analytical models, such as those involving the use of dynamic programming, may fail to generate an optimal control policy for modern production systems. Modern production systems are often in possession of the features that allow them to produce various types of product through multiple working …

Inference For A Zero-Inflated Conway-Maxwell-Poisson Regression For Clustered Count Data., Hyoyoung Choo-Wosoba

Electronic Theses and Dissertations

This dissertation is directed toward developing a statistical methodology with applications of the Conway-Maxwell-Poisson (CMP) distribution (Conway, R. W., and Maxwell, W. L., 1962) to count data. The count data for this dissertation exhibit three different characteristics: clustering, zero inflation, and dispersion. Clustering suggests that observations within clusters are correlated, and the zero inflation phenomenon occurs when the data exhibit excessive zero counts. Dispersion implies that the mean is greater/smaller than the variance unlike a Poisson distribution. The dissertation starts with an introduction of inference for a zero-inflated clustered count data in the first chapter. Then, it presents novel methodologies …

An Adaptable Fuzzy-Based Model For Predicting Link Quality In Robot Networks., Christopher J. Lowrance

Electronic Theses and Dissertations

It is often essential for robots to maintain wireless connectivity with other systems so that commands, sensor data, and other situational information can be exchanged. Unfortunately, maintaining sufficient connection quality between these systems can be problematic. Robot mobility, combined with the attenuation and rapid dynamics associated with radio wave propagation, can cause frequent link quality (LQ) issues such as degraded throughput, temporary disconnects, or even link failure. In order to proactively mitigate such problems, robots must possess the capability, at the application layer, to gauge the quality of their wireless connections. However, many of the existing approaches lack adaptability or …

Urban Flooding And Sewer Inundation On The University Of Louisville Belknap Campus., Justin T. Hall

Electronic Theses and Dissertations

Over the past few decades on the University of Louisville Belknap campus urban flooding has become more frequent as a result of surface water runoff and sewer inundation. This urban flooding is a result of ongoing watershed urbanization and rapid expansion of the local sewer system to accommodate the expanding city of Louisville. However little research has been conducted on this issue, despite continued flooding on and adjacent to campus. Using the EPA Storm Water Management Model (SWMM) we applied a dual drainage modeling approach that combines both surface and subsurface drainage data to produce a flood hydrograph at the …

Adaptive Schools : Investigating Impact, Continuity, And Change In One School District., Winn Crenshaw Wheeler

Electronic Theses and Dissertations

This dissertation is an examination of the work of Adaptive Schools in Smith County Schools. It begins by explaining how the work of Adaptive Schools is relevant in the larger context of school reform. To explore this relevance, a qualitative analysis of Smith County was conducted. Smith County was selected based on systematic implementation of the work of Adaptive Schools. Analysis of interview data focused on: the impact of the work of Adaptive Schools within Smith County and the degree to which Adaptive Schools intersected with themes of continuity and change. Further analysis explores emergent questions about: (a) the function …

Mixing And Mean Age In Multiphase Systems., David Chandler Russ

Electronic Theses and Dissertations

Mean age theory is a useful tool for analyzing mixing by providing spatial distributions of time based data for material inside a system using a steady-state CFD approach, but has been limited to single phase systems. Mean age theory was extended here to multiphase systems by defining the scalar tracer concentration independently for individual phases, which allows mean age to be solved at steady-state for each phase independently within a multiphase system. The theory was validated by comparing multiphase mean age (MMA) distributions extracted from spatial distributions determined computationally at two locations where RTDs were experimentally measured in a water-oil …

Examining The Effectiveness Of Implementing Orton-Gillingham Reading Intervention On Student Engagement For Elementary Students With Challenging Behaviors., Lauren L. Evanovich

Electronic Theses and Dissertations

Providing support to students with challenging behaviors is a critical focus of classroom teachers’ success. Finding ways to prevent and mediate academic and behavioral difficulties is a high priority area for both research and practice. The focus of this dissertation is on the effects of implementation of Orton-Gillingham Reading intervention strategies on active engagement for students with challenging behaviors. This study is a single-subject alternating treatments design across 3 elementary school classrooms, that examined the effects of increasing the rate of teachers’ positive feedback and OTRs on students’ engagement as measured direct observations for students identified with challenging behaviors. Dissertation …

Green Logistic Network Design : Intermodal Transportation Planning And Vehicle Routing Problems., Xiaoren Duan

Electronic Theses and Dissertations

Due to earth's climate change and global warming, environmental consideration in the design of logistic systems is accelerating in recent years. In this research we aim to design an efficient and environmentally friendly logistical system to satisfy both government and carriers. In particular, we considered three problems in this dissertation: intermodal network design, deterministic green vehicle routing problem and stochastic green vehicle routing problem. The first problem aims to design an economic and efficient intermodal network including three transportation modes: railway, highway and inland waterway. The intent of this problem is to increase the utilization percentage of waterway system in …