University of Idaho Library Digital Initiatives
Not a member yet
54971 research outputs found
Sort by
Methodology for Transient Stability Analysis of an Interconnected Power Grid from a Reduced Order System Model
No full textToday, the power system of the Baltic States (comprised of Lithuania, Latvia, and Estonia) is synchronized with the Integrated/Unified Power System (IPS/UPS) of Russia and Belarus. It is planned that by 2025 they desynchronize from the IPS/UPS system and to join the largest interconnection in the world, Continental Europe. The goal of this master thesis is to delve further into planned out-year operations in the European power grid with the synchronized connection of the Baltic States. To understand this topology, there needs to be a methodology for performing the power system analyses of the interconnected large power grid, particularly the case when the smaller grid is being connected to a large power system and when the models available are limited in terms of fidelity and completeness. The focus of this research is threefold: 1) develop a procedure on how to find an AC solution from an approximated DC solution; 2) present a methodology for building the transmission system model from scratch using only publicly available data and 3) conduct dynamic studies to ensure reliable operation of the interconnected system. In this research, an open-source European grid model will be used, however, the available model was only built to study simple DC power flow solutions. The process of finding an AC solution from a DC one has been a difficult topic for the power system industry, and a new methodology on how to achieve this is proposed and will be discussed and demonstrated. The Baltic States transmission power grid equivalent will be added by using publicly available data for the transmission system topology, generation capacity, and load distribution. Finally, dynamic generation machine and control models are going to be introduced and assigned to the model, based upon the type of generation that exists at each location (or large-scale equivalent). The built model of the integrated grid will allow a wide range of studies, from steady state to dynamic and it will help in the development of the new control and protection schemes to assist in increased system stability. To demonstrate the value of the developed model, a transient stability analysis will be performed on the interconnected model to analyze both the impact of the Baltic States on the dynamic stability of the interconnected grid, and the impact of events in the European grid on the Baltic States through the synchronous connection.masters, M.S., Electrical and Computer Engineering -- University of Idaho - College of Graduate Studies, 2020-1
A Survey of Firmware Analysis Techniques and Tools
No full textThis thesis attempts to cover many aspects concerning analysis, reverse engineering, and provenance attribution of firmware from embedded devices. The intended reader of this thesis is someone familiar with, or at least aware of, the software build process, the analysis of software, and reverse engineering of software. This thesis discusses some of the differences between firmware and traditional software and may serve as a bridge for those readers that may be more familiar working in a software environment and are interested in analyzing embedded devices. The thesis will include strategies for retrieving firmware binaries from a target device, reverse engineering with the intent to provide provenance information about the firmware, and briefly cover future work of using machine learning to analyze firmware.masters, M.S., Computer Science -- University of Idaho - College of Graduate Studies, 2020-0
A Coevolutionary Community Ecology
No full textSpecies in the wild exhibit an immense diversity of forms, functions and abundances. To understand this diversity we must consider the processes that have shaped it along with the biological details these processes emerge from. For example, species are often found interacting with other species in an ecological community and these interspecific interactions can lead to a wide variety of ecological and evolutionary processes. The frequency of interspecific interactions across a set of species is determined in part by the abundance of each species. More abundant species tend to interact more often. However, the fluctuations in species abundance is itself determined in part by interspecific interactions. The combination of these two causal pathways creates a feedback loop between the patterns of interspecific interactions among species and the patterns of species abundance. Although classical community ecology has largely focused on studying patterns of diversity through the lense of feedbacks between interspecific interactions and species abundances, much of this work has ignored an important aspect of species. In particular, species are not monolithic entities, but are comprised of diverse sets of individuals. Furthermore, these individuals are characterized by suites of behavioural and morphological traits that mediate the outcomes of interactions with other individuals, including lifetime reproductive output (i.e., fitness). When particular trait values are associated with increased fitness, the species experiences selection for those trait values. If those trait values are also heritable, so that offspring traits resemble parental traits, they will tend to increase in frequency. Hence, interactions among individuals provide building blocks from which both ecological and evolutionary processes emerge. In turn, the evolution of traits mediating interactions can modify the patterns and outcomes of interactions, generating feedbacks between the ecological and evolutionary processes emerging from individual interactions. Thus, to understand the patterns and dynamics of species and the ecological communities they compose, we must consider a holistic framework that treats the evolutionary and ecological responses of species to their interactions as the products of a common underlying phenomenon; interactions among individuals. In this dissertation I introduce a novel mathematical framework rigorously derived from biological first principles that accomplishes this goal. Using this framework to investigate communities of species competing along a resource gradient, I find a positive correlation between the strength of selection and the strength of competition across interacting species pairs. I then apply this framework to study the consequences of coevolutionary races for the stability of mutualistic interactions, demonstrating that the tendency for mutualisms to disintegrate into parasitisms depends on the phenotypic interface of the interaction. Finally, I introduce a new statistical method to measure the strength of coevolution between pairs of species in the wild. Applying this method to two well studied cases, I find support for the role of coevolution in both cases and calculate first ever estimates for the strength of coevolution in the wild. Overall, this work contributes to a coevolutionary theory of community ecology by developing rigorous mathematical tools that embrace the interwoven nature of ecological and evolutionary processes, deriving novel results on the consequences of coevolution in shaping interspecific interactions, and introducing a new statistical method to infer the coevolutionary process from empirical patterns. Future research based on this work may lead to a deeper synthetic understanding of the diverse and dynamical nature of life along with methods to forecast the responses of wild populations to our changing world.doctoral, Ph.D., Bioinformatics & Computational Biology -- University of Idaho - College of Graduate Studies, 2020-0
Additions and Improvements to the Mechanical Design of the FINGER Exoskeleton
No full textRehabilitation robots are important tools for post stroke movement training and efficacy quantification. The Finger INdividuating Grasp and Exercise Robot (FINGER) is a robotic exoskeleton designed to administer and study finger movement training. Developed nearly a decade ago and used for numerous investigative studies, the FINGER exoskeleton is currently in the process of being updated. This thesis covers design improvements to the FINGER 8-bar mechanisms, development of novel finger cuffs, and initial solid-model design prototyping of a spherical 5-bar mechanism for thumb training. The 8-bar mechanisms that FINGER uses to actuate the index and middle fingers were redesigned with thicker links to increase rigidity and to reduce high stress concentrations. The joints of the mechanism were modified to use larger bearings with an extended inner race, allowing them to be easily spaced without the need for shims. The mechanism was also modified to extend an additional fifteen degrees to allow the user to fully open their index and middle fingers. Feedback from patients and clinicians about the fit and function of FINGER has been used to redesign the finger cuffs to be more comfortable, and to be easier to don and doff. This was achieved by adding BOA® ratchet dials which use braided metal cables that size the cuffs; the cables loop over a hook on the opposite side. The cable is covered by a leather strap which increases comfort, keeps the cable properly aligned, and prevents direct contact between the cable and the skin. Thumb trajectory information, recorded using a marker-based motion capture system, was used for the kinematic design of a spherical 5-bar mechanism. This mechanism will be actuated by the same linear actuators as FINGER, which are fixed to a platform on which FINGER is secured. A proposed design, including the location of these actuators, is presented. The thumb is connected to the mechanism through a cuff with a BOA® dial and a leather strap, similar to the finger cuffs. The thumb cuff rotates freely so the thumb can assume a comfortable orientation.masters, M.S., Mechanical Engineering -- University of Idaho - College of Graduate Studies, 2020-0
Allowing Distributed Generation to Improve Power System Stability By Applying Virtual Synchronous Machine Approach
No full textThe installed power capacity of DG is increasing; many of distributed generators are connected to a grid by inverters. The DC/AC inverters are controlled by a Phase Locked Loop (PLL) so they can be synchronized with power system frequency. If this capacity becomes larger, the grid power system become unstable, because the inverter is controlled to follow the power grid frequency. Performance of a photovoltaic generation (PV) plant with an integrated battery energy storage system (BESS) is examined under different system conditions. Although the penetration of distributed renewable energy sources into the traditional grid has risen over the past decade, the potential negative impact of this integration can never be overemphasized. The proposed scheme is evaluated in system studies under fluctuating levels of solar irradiation related to the weather conditions. As the changes in irradiation and temperature occur, the dc link voltage changes due to the changes in power produced, the inverter ac power is controlled to regulate the dc voltage. This research models are energy management system which is based on a hysteresis control algorithm for the battery, which limits the abrupt charging/discharging of the battery, thus increasing battery lifespan which also compensating for change in PV output and power system conditions. The PV source does not have significant energy storage. However, it can supply small quantity of energy for the grid system because it has dc capacitor located in the dc link. Separate energy storage, such as a battery, can work with a PV source to supply energy for the frequency control. In addition, with increasing penetration of the inverter based power generation, there is decrease in inertia due to the fast frequency tracking of the PLL, which speed up dynamic behavior and stability problems on the power grid. To mitigate this problem, the integration of virtual synchronous generators (VSG) based on the photovoltaic (PV) generation plus energy storage is proposed. This research implemented the VSG control based on the swing equation model of a synchronous generator. The VSG can be designed to aid the integration of large-scale photovoltaic generation into the power grid. Through this concept, it is plausible for the DG to exhibit the characteristics and behavior of synchronous generators (SG) such as inertia behaviour, droop functions and damping. These factors make it possible for the PV to contribute to the control and stability of the power grid. The work also presents a proposed a simple method calculating approximate for approximating battery sizing with respect to power and energy by providing emulation inertia in order to meet the target system inertia and power/frequency characteristics. Three cases were simulated in order to calculate the amount of the battery energy sizing needed to support the power grid inertia which reduces the rate of change of frequency deviation. These models are designed and simulated in the electromagnetic alternate transients program (ATP) to simulate the power system. The power grid is testing with the ATP program and validated with powerworld simulator.doctoral, Ph.D., Electrical and Computer Engineering -- University of Idaho - College of Graduate Studies, 2020-0
Life-history Evolution, Abiotic Constraints, and Climate Adaptability of Burrowing Owls (Athene cunicularia) Breeding Along a Latitudinal Gradient
No full textTwo of the most prominent contemporary goals of ecology are to: 1) understand how populations are regulated through variation in the rates of births and deaths and, 2) to elucidate, anticipate, and mitigate the impacts of climate change and other environmental changes on wildlife populations. These two objectives are inherently linked because to fully understand how populations will respond to climate change, we first need an improved understanding of how they are currently adapted to their thermal environment. However, the extent to which fitness is directly linked to the abiotic environment and the specific mechanisms that mediate those relationships are often poorly understood. Therefore, we need a more detailed understanding of the patterns and drivers of life-history variation and the ways in which such variation is driven by thermal effects. I examined intraspecific patterns and causes of life-history variation within a single widespread species, the Burrowing Owl (Athene cunicularia), breeding along a 1400-km latitudinal gradient in western North America from 2015 – 2018. My overall objectives were to: 1) document latitudinal and other patterns of variation in a large suite of life-history traits and breeding behaviors, 2) test mechanistic hypotheses to explain that variation with an emphasis on examining abiotic and thermal mechanisms, and 3) understand the complex trade-offs and interactions among traits, activities, and allocation decisions occurring at different stages of the avian reproductive cycle. We used motion-activated video recording inside of occupied Burrowing Owl nests to gain detailed data on the reproductive behaviors of Burrowing Owls across all stages of the reproductive cycle. Chapter Two documents latitudinal patterns in a suite of traits related to hatching patterns and hatching asynchrony, tests a thermally-based hypothesis to explain the cause of asynchronous hatching, and considers whether the same mechanism responsible for asynchronous hatching might also explain the latitudinal variation in clutch size. We found that most traits varied clinally with latitude, but all the traits were more strongly associated with individual nest microclimates than with latitude, and all in the directions predicted by the egg viability hypothesis. These results suggest that abiotic conditions in the nest drive an important life-history tradeoff and that thermal gradients are sufficient to account for observed biogeographic and seasonal patterns in life-history strategies. Chapter Three documents latitudinal variation in egg-laying behaviors and tests hypotheses to explain variation in laying interval. Burrowing Owls laid eggs at all times of day but laid more eggs in the morning hours, and that tendency was strongest among first eggs in a clutch (i.e., nest initiation times). Laying interval duration varied dramatically, was negatively correlated with latitude, and was associated with burrow temperature and with numerous behavioral and life-history traits. Our results indicate that laying interval is not a fixed constraint on avian reproduction but rather should be considered an important life-history trait in future studies. Chapter Four documents latitudinal variation in incubation behavior, examines patterns and sources of variation in nest attentiveness, and uses a hypothetico-deductive approach to test a pair of alternative hypotheses to explain variation in incubation period length. Daily nest attentiveness, cumulative nest attendance, and incubation period duration all increased with increasing latitude, but that variation could be accounted for by predicted life-history tradeoffs. Burrowing Owls reduced their daily attentiveness on days that the average burrow temperature was within the range that is optimal for embryo development. Finally, variation in incubation periods was best explained by cumulative nest attendance instead of daily nest attentiveness suggesting that variation in incubation periods is driven by differential selection on neonate quality, as suggested by the neonate quality hypothesis. Chapter Five reviews the historical development of “Ashmole’s hypothesis” of clutch size evolution, which is based in a simple abiotic mechanism driven by seasonality of productivity. I summarize the empirical evidence in support and against Ashmole’s hypothesis, and then discuss and clarify numerous sources of confusion in the existing literature surrounding the hypothesis. As a whole, this dissertation documents numerous biogeographic patterns in avian life-histories that have heretofore been unknown or poorly documented, it provides new insights into the drivers of that variation in into the drivers of life-history variation generally, and it identifies mechanisms by which avian reproduction is adapted to the abiotic environment and may therefore respond to climate change.doctoral, Ph.D., Natural Resources -- University of Idaho - College of Graduate Studies, 2020-0
Evidence of High Relief Eocene Topography in the Southern Idaho Batholith and Constraints on Rift-related Exhumation in the Miocene Western Snake River Plain, Idaho, Using Apatite (U-Th)/He Thermochronometry
No full textThe western Snake River Plain (WSRP) in southwest Idaho has been characterized as an intracontinental rift basin but differs markedly in orientation and style from other western Cordilleran extensional structures. Understanding the rifting history of the WSRP and exhumation of its mountainous flanks can have implications for other intracontinental rift basins and for the topographic evolution of this region within the broader tectonic context. We sampled granitoid bedrock from Cretaceous and Eocene-aged plutons from the flanks of the WSRP to detail their exhumation history with apatite (U-Th)/He (AHe) thermochronometry. We present new AHe dates from seventeen samples, with cooling dates ranging from 7.9±1.4 Ma to 55±10 Ma. The majority of cooling dates for the Cretaceous plutons are Eocene, and the Eocene intrusions yield Miocene dates. The AHe dates provide thermochronological evidence of rapid cooling and exhumation of the Idaho batholith during the Eocene. This support the presence a high relief landscape in Idaho associated with regional uplift due to Farallon slab rollback and Challis magmatism. This high landscape was rapidly eroded and supplied massive amounts of sediment to Eocene basins across the Cordillera. We also find evidence for a post-Eocene decrease in relief, seen in the negative slope on date-elevation relationships in the southwest flank of the WSRP. Our AHe dates indicate limited exhumation on the flanks of the WSRP during Miocene rift formation. We interpret this to be evidence of extension dominated by magmatic intrusions and intrabasin faults rather than basin-bounding faults. Focused exhumation ~20-7 Ma seen in the Eocene pluton relates to concentrated incision along the Middle Fork Boise River in the interior of the Boise Mountains due to relative base level fall or more recent uplift due to plume-associated magmatism.masters, M.S., Geology -- University of Idaho - College of Graduate Studies, 2020-0
The dynamics ofPhysarum polycephalumfungitaxis and photoavoidance.
No full textIn my thesis I have tried to answer the following questions: What effects do different patterns and amounts of light exposure have on Physarum fungitaxis and morphogenesis? Are the dynamics of Physarum and yeast interaction modulated by light? Can we characterize the Physarum light response and its interactions with a red yeast such that we can input a sequence of light into Physarum's environment such that we can increase or decrease the rate at which it consumes a red yeast (we have not genotyped this micro-organism). Physarum morphogenesis and fungitaxis(how it interacts with a red yeast) were measured using several week-long image sequences taken with flatbed scanners. These images were segmented using the semi-supervised iterative pipeline of U-Net and Ilastik. These semantic (as in we defined elements of the image that should be labeled by the network) segmentations were used to measure the mass and morphology of yeast, oats, and Physarum in all images. With these measurements, we analyzed the interactions shared between Physarum and red yeast. We find that these interactions occur at specific spatial scales. Running our data through the FNN-LSTM autoencoder help us to better understand the dynamics of these interactions. We find that Physarum and yeast interactions are succesional. Physarum maintains yeast as a periodic food source by depositing a nutritive slime trail after it consumes most of the yeast. With these observations we moved on to the other component of our research program, how Physarum morphogenesis is influenced by light exposure. To answer this question we trained a triplet loss embedding (a supervised clustering algorithm that works on user defined/semantic labels). We were unable to generate satisfactory clusters with this embeddinga/clustering algorithm. Individual plasmodia clustered with each other in temporally coherent sequences within the latent space. Instead of constructing a latent space with which we could understand photomorphogenesis and photomovement we found a pathological feature of the Triplet embedding algorithm. With this failure in mind, we tried to construct a morphospace of Physarum morphogenesis. With this morphometric approach, we were unable to find evidence that photoexposure itself shapes Physarum morphogenesis over the course of a week. This observation in some ways contradicts the existing literature in which Physarum avoids blue light and the peristaltic pumping that drives Physarum movement is disrupted by light exposure. It is possible that Physarum habituates to the regime of light exposure and loses sensitivity during the course of an experiment. To investigate this hypothesis, we propose new experiments to better understand the temporal dynamics of photoavoidance (how Physarum avoids a particular region of light) in contrast to photomorphogenesis where its whole environment is illuminated. With these new observations, we may be able to better understand Physarum photoavoidance and its relationship with fungitaxis. We may also be able to characterize a decay in the Physarum photoavoidance response that would in itself be an important result.masters, M.S., Bioinformatics & Computational Biology -- University of Idaho - College of Graduate Studies, 2020-1
Orientation-Dependent Analysis in Mineralogy: Methods and Practice
No full textThe central theme of this dissertation is the importance of orientation when analyzing an anisotropic mineral. Whether this is for identifying the mineral or for characterizing composition or structure, information about the orientation of a particular characteristic can provide unique information about the mineral. For example, in visible light optics of anisotropic minerals, a crystal will have differing refractive indices based on the incoming wavelength and orientation in which light is vibrating through the crystal. These properties are dictated by the chemical composition and structure of the mineral, and when combined with other information about the crystal, such as the locations of crystallographic planes, absorption characteristics, and relative refractive indices, an unknown mineral can be narrowed down often to a particular species using optical mineralogy alone. If a crystal contains proper rotational symmetry, these axes will also correspond with the rotational symmetry of the optical indicatrix, which can be used in crystal structure determination. In absorption spectroscopy, there is evidence that polarization effects from anisotropic crystals influence relative absorption magnitudes outside of the visible light spectrum, even at X-ray wavelengths. In high resolution transmission electron microscopy, image resolution is markedly improved by imaging sections viewing down zone axes, where atomic columns are largely in line. Additionally, electron diffraction patterns viewing down zone axes provide more information about symmetry and structural periodicities. By knowing the orientation of a crystal in thin section, TEM mounts can target specific zone axis orientations of a crystal to obtain meaningful structural information. With knowledge of orientation, precession electron diffraction tomography is expedited when collecting intensity maxima near zone axes, which supplements ab initio structural determination of difficult structures, such as strongly disordered and/or modulated crystal structures. The contents of this dissertation proceed with calculations and methods for orienting crystals by their crystallographic and optical orientations. Using these methods, the remainder of this dissertation outline applications of these methods applied to optical characterization and identification of minerals, an orientation and ferric content model for iron K X-ray absorption in pyroxenes, and a study on structural variation and defects in serpentine minerals and amphiboles from Western Idaho, and their relation to geology and asbestiform mineral occurrences.doctoral, Ph.D., Geology -- University of Idaho - College of Graduate Studies, 2020-0
