Alarm Forecasting in Natural Gas Pipelines

This thesis examines alarm forecasting methods for a natural gas production pipeline to assure the efficient transportation of high-quality natural gas. Natural gas production companies use pipelines to transport natural gas from the extraction well to a distribution point. Forecasting natural gas pipeline pressure alarms helps control room operators maintain a functioning pipeline and avoid costly down time. As gas enters the pipeline and travels to the distribution point, it is expected that the gas meets certain specifications set in place by either state law or the customer receiving the gas. If the gas meets these standards and is accepted at the distribution point, the pipeline is referred to as being in a steady-state. If the gas does not meet these standards, the production company runs the risk of being shut-in, or being unable to flow any more gas through the distribution point until the poor-quality gas is removed.Sensors are used to collect real-time gas quality information from within the pipe, and alarms are used to alert the control operators when a threshold is exceeded. If operators fail to keep the pipeline’s gas quality within an acceptable range, the company risks being shut¬¬-in or rupturing the pipeline. Predicting gas quality alarms enables operators to act earlier to avoid being shut-in and is a form of predictive maintenance. We forecast alarms by using a 10th-order autoregressive model, autoregressive model with exogenous variable, simple exponential smoothing with drift (Theta Method) and an artificial neural network with alarm thresholds. The alarm thresholds are defined by the production company and are occasionally adjusted to meet current environment conditions. The results of the alarm forecasting method show that we accurately forecast natural gas pipeline alarms up to a 30-minute time horizon. This translates into sensitivity rates that drop from around 100% at one minute to 82.7% at a 30-minute forecast horizon. This means that at 30 minutes, we correctly forecast 82.7% of the alarms. All alarm forecasting models outperform the state-or-the-art forecaster used by the production company, with the artificial neural network performing the best

Ecological interactions involving plant selenium hyperaccumulation

2010 Summer.Includes bibliographic references.Covers not scanned.Print version deaccessioned 2022.To view the abstract, please see the full text of the document

Effects of Exercise Training and Doxorubicin on Myogenic Regulatory Factors

Doxorubicin (DOX) is a widely used anthracycline antibiotic used to treat a number of hematological and solid tumor cancers. Dosage; however, is limited due to its toxic effects in healthy tissues. Negative consequences include myotoxicity in skeletal muscle, which may limit mobility and activities of daily living. The capacity for skeletal muscular regeneration relies heavily of the activity of myogenic regulatory factor (MRF) proteins. In vitro experiments with DOX depress expression of MRFs but in vivo treatment may elicit different responses. Endurance exercise has been shown to elevate MRF expression, and may preserve MRFs following in vivo DOX-treatment. Purpose: To determine the effect of short-term endurance training and acute DOX administration of skeletal muscle force production and fatigue resistance, levels of lipid peroxidation, and expression of MRFs. Methods: Ten week old male Sprague-Dawley rats were randomly assigned to one of four groups: sedentary + saline (SED-SAL), SED- DOX, endurance exercise training + saline (EXER-SAL), or EXER-DOX. Animals remained sedentary or performed treadmill training for two weeks. Twenty four hours after the activity period, animals were injected with a bolus 15 mg/kg i.p. injection of DOX or SAL. Twenty four hours after injection, soleus (SOL) and extensor digitorum longus (EDL) skeletal muscles were removed for ex vivo function measures. Analyses of lipid peroxidation as malondialdehyde and 4-hydroxyalkenals (MDA + 4-HAE) and Western blotting for concentration for MRFs (Myf5, MyoD, myogenin, Mrf4) were performed on contralateral muscles. Results: Endurance exercise significantly elevated Myf5 and Mrf4 in the SOL (p\u3c0.05). No significant differences existed in MRF expression levels in the EDL. No significant muscle force production or fatigue resistance differences were identified due to drug or activity treatment. MDA + 4-HAE was higher in the SOL of SAL animals (p\u3c0.05) and EDL of EXER animals (p\u3c0.05). Conclusion: Short-term endurance exercise effectively elevated Myf5 and Mrf4 in slow, oxidative muscle after acute DOX treatment. Endurance exercise prior to chemotherapy may augment skeletal muscles’ regenerative capacity following treatment, when loss of muscle mass is common

Visualizing probabilistic models: Intensive Principal Component Analysis

Unsupervised learning makes manifest the underlying structure of data without curated training and specific problem definitions. However, the inference of relationships between data points is frustrated by the `curse of dimensionality' in high-dimensions. Inspired by replica theory from statistical mechanics, we consider replicas of the system to tune the dimensionality and take the limit as the number of replicas goes to zero. The result is the intensive embedding, which is not only isometric (preserving local distances) but allows global structure to be more transparently visualized. We develop the Intensive Principal Component Analysis (InPCA) and demonstrate clear improvements in visualizations of the Ising model of magnetic spins, a neural network, and the dark energy cold dark matter ({\Lambda}CDM) model as applied to the Cosmic Microwave Background.Comment: 6 pages, 5 figure

The Crucible of Complexity: Community Organization and Social Change in Bronze Age Transylvania (2700-1320 BC)

This dissertation examines the development of regional polities with institutionalized inequality in Bronze Age Transylvania, Romania (2700-1320 BC). During the Bronze Age, southwest Transylvania became one of the most important mining regions in Europe, providing the copper, tin, and gold that funded the establishment of permanent social hierarchies across the continent. Through a holistic approach across social, economic, and ideological institutions, I document how communities living in these metal-rich mountains participated in, and were effected by, these social, political, economic, and ideological transformations. Specifically, I focus on two interrelated research questions: (1) How were communities in the mining districts of southwest Transylvania organized during the Bronze Age, and (2) How did community organization in southwest Transylvania change throughout the Bronze Age? This study makes two important contribution to the culture history of the Transylvanian Bronze Age. First, I develop an absolute chronology for the Transylvanian Bronze Age based on the largest corpus of dates yet published. Second, I present a regional survey and spatial analyses conducted in Transylvania to document changes in community organization at multiple scales. This study develops the first historical trajectory of the organization of economic, political, social, and ideological institutions in Bronze Age Transylvania. More broadly, this dissertation builds on existing frameworks for studying community organization in middle-range societies in two key ways. First, it moves beyond political economic approaches to incorporate alternative pathways towards hierarchical complexity. In addition to economic and political realms, ideologies, identities, and how they are materialized are important factors in the institutionalization of inequality. Different institutions, however, will not always be organized the same way. I argue that the coherence and dissonance in the presence of inequalities across institutions is a critical attribute of social organization. Second, it further problematizes the study of change in community organization in middle-range societies. The proposed framework distinguishes qualitative and quantitative changes in how institutions are organized, how they articulate, and social forms that emerge out of human action and institutional conditions. Through examination of settlement, mortuary, chronological, and artifactual evidence, I argue that inequality became institutionalized only during the Late Bronze Age, centuries later than previously assumed. Throughout the Early and Middle Bronze Ages, there was dissonance across multiple institutions in how inequality was made, marked, and masked. Many institutional changes that occurred throughout the Early and Middle Bronze Age set the stage for Late Bronze Age social transformations. In particular, the expansion of long-distance trade, a diversification in burial rites that emphasized intra-community difference, and an increase in the venues for signaling identities and inequalities provided opportunities for Late Bronze Age communities to reorganize hierarchically. These institutional changes were incremental, and unintentionally created the context in which historically specific events and processes ultimately led to the emergence of complex regional polities. The social history of communities in southwest Transylvania challenges how archaeologists conceptualize mining districts in Bronze Age Europe. In regions with rich ore sources, more than just metal procurement mattered. In southwest Transylvania, changes in social organization throughout the Bronze Age involved ideological, political, social, and economic institutions beyond metal procurement. The archaeology of pre-state societies in mining districts is uniquely positioned to contribute a deep historical perspective to the origin and evolution of the dynamics of resource extraction.PHDAnthropologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/138470/1/cpquinn_1.pd

Modelling the Performance of Irish Credit Unions, 2002 to 2010

This study undertakes a modeling based performance assessment of all Irish credit unions between 2002 and 2010, a particularly turbulent period in their history. The analysis explicitly addresses the current challenges faced by credit unions in that the modeling approach used rewards credit unions for reducing undesirable outputs (impaired loans and investments) as well as for increasing desirable outputs (loans, earning assets and members’ funds) and decreasing inputs (labour expenditure, capital expenditure and fund expenses). The main findings are: credit unions are subject to increasing returns to scale; technical regression occurred in the years after 2007; there is significant scope for an improvement in efficiency through expansion of desirable outputs and contraction of undesirable outputs and inputs; and that larger credit unions, that are better capitalised and pay a higher dividend to members are more efficient than their smaller, less capitalised, and lower dividend paying counterparts

Organic-Conventional Dairy Systems Trial in New Zealand: Four Years’ Results

The Organic-Conventional Comparative Dairy Systems trial at Massey University began in August 2001, and the organic farmlet achieved certification in August 2003. The trial is unique because it is the only comparative grassland-based open grazing dairy study in the world. The organic and conventional systems are managed individually according to best practice, and both are intensively monitored for production, animal health, and environmental impacts. The systems remained similar for the first two years, but began to diverge in the third and fourth years. Production has been 10-20% lower on the organic farm, but environmental impacts appear to be less than on the conventional unit, and net incomes would be similar given a 20% price premium for the organic product. Animal health issues have been manageable on the organic farmlet, and not too dissimilar from the conventional farmlet. Full results after four years of the trial will be available and presented at the conference

Selenium Hyperaccumulators Facilitate Selenium-Tolerant Neighbors via Phytoenrichment and Reduced Herbivory

SummaryBackgroundSoil surrounding selenium (Se) hyperaccumulator plants was shown earlier to be enriched in Se, impairing the growth of Se-sensitive plant species. Because Se levels in neighbors of hyperaccumulators were higher and Se has been shown to protect plants from herbivory, we investigate here the potential facilitating effect of Se hyperaccumulators on Se-tolerant neighboring species in the field.ResultsWe measured growth and herbivory of Artemisia ludoviciana and Symphyotrichum ericoides as a function of their Se concentration and proximity to hyperaccumulators Astragalus bisulcatus and Stanleya pinnata. When growing next to hyperaccumulators, A. ludoviciana and S. ericoides contained 10- to 20-fold higher Se levels (800–2,000 mg kg−1 DW) than when growing next to nonaccumulators. The roots of both species were predominantly (70%–90%) directed toward hyperaccumulator neighbors, not toward other neighbors. Moreover, neighbors of hyperaccumulators were 2-fold bigger, showed 2-fold less herbivory damage, and harbored 3- to 4-fold fewer arthropods. When used in laboratory choice and nonchoice grasshopper herbivory experiments, Se-rich neighbors of hyperaccumulators experienced less herbivory and caused higher grasshopper Se accumulation (10-fold) and mortality (4-fold).ConclusionsEnhanced soil Se levels around hyperaccumulators can facilitate growth of Se-tolerant plant species through reduced herbivory and enhanced growth. This study is the first to show facilitation via enrichment with a nonessential element. It is interesting that Se enrichment of hyperaccumulator neighbors may affect competition in two ways, by reducing growth of Se-sensitive neighbors while facilitating Se-tolerant neighbors. Via these competitive and facilitating effects, Se hyperaccumulators may affect plant community composition and, consequently, higher trophic levels