Browsing by Subject "Distribution"
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Item Cita : a feminist open-access digital library and print-on-demand publisher(2018-05-07) Castro Varón, Juliana; Park, Jiwon, M.F.A.; Gorman, CarmaMost of the nineteenth century’s feminist literature is now in the public domain, but many of these writings are not being republished by commercial publishers. When publishers do reprint public-domain texts, they rarely do so in open-access book formats. Because commercial publishers invest in curating and marketing well designed collections of reprints, they frequently commission original annotations or introductions from scholars, which in turn enables them to copyright and profit from their new editions. In contrast, Internet-based archives such as Google Books, HathiTrust, and Archive.org make an enormous corpus of public-domain books available for free online, but do so as scans or in poorly designed digital formats. Moreover, internet archives usually do not make their collections particularly navigable or appealing to non-scholarly audiences, nor do they make it properly designed and easy to print. Responding to the lack of well designed, affordable public-domain reprints, Cita is an open-access feminist digital library and print-on-demand publisher that promotes and distributes the writings of female authors whose works are open-licensed or in the public domain. Cita’s network of scholars and designers works to make and distribute free, high-quality editions that readers can view online using any device, or download, print, and—following simple instructions—bind for personal, library, museum, or school use.Item Consumer-Data Approach to Assess the Effect of Residential Grid-Tied Photovoltaic Systems and Electric Vehicles on Distribution Transformers(IEEE, 2014-06) Uriarte, F. M.; Toliyat, A.; Kwasinski, A.; Hebner, R. E.The authors examine the impact of residential photovoltaic arrays and electric vehicles on distribution transformers by using 3-D surface and 2-D filled contour plots. These visualizations, somewhat unorthodox to power distribution analysis, elucidate the impact of hundreds of assets on distribution transformers on a single view. The visualizations are created with a smart grid computer model that accepts residential electrical recordings in one minute intervals. An analysis of simulation results shows that the electrical footprint experienced by a residential community and its distribution transformers stems from photovoltaic arrays rather than from electric vehicles. Additionally, the results indicate the existing distribution assets may be ready to support the proliferation of photovoltaic arrays and electric vehicles, a common concern across utilities in the United States.Item Did Rififi... really mean trouble?(2022-05-05) Geffard, Alexander N.; Frick, Caroline; Fuller-Seeley, KathrynThis paper uses archival research of American trade magazines to provide a chronicle of the articles concerning the worldwide and United States releases of Jules Dassin’s 1955 French heist film Rififi. It explores the popular critical discourses published by journalists, critics, editors, and readers over the course of three years in light of the fact that the film was made by an American director who was blacklisted as a Communist by the House Un-American Activities Committee. In addition, the study highlights Rififi’s relevancy with the evolving distribution business relationship between the United States and the European countries across the Atlantic.Item The energy-water nexus : energetic analysis of water and wastewater treatment, distribution and collection(2014-12) Kjellsson, Jill Blosk; Webber, Michael E., 1971-The water sector is responsible for a significant portion of energy use. Energy is required for water treatment, water distribution, wastewater collection and wastewater treatment. There is significant benefit to water utilities that can be gained by understanding how much energy, what type of energy, and at what time of day energy is being used. The Austin Water Utility (AWU) is a useful testbed for examining the energy use for each specific step of the process due to the availability of data and the fact that the majority of Texas (both in terms of population and land area) is serviced by a single electric grid. This research examines the type and quantity of energy used by AWU. From an electricity supply perspective, electric utilities work year round to ensure that there is enough electricity in their generation portfolios to meet the high loads that their customers demand, and to assure that the electric distribution grid is capable of providing the transmission requirements of that electricity. System peak demand is the largest amount of electricity consumed by a utility's customers at any given time. Therefore electric utilities, such as Austin Energy, create and market their energy efficiency programs to help reduce this peak and avoid the need to build new generation capacity which can be expensive. Because AWU is one of Austin Energy's largest customers, AWU's ability to shift its energy use from on-peak to mid-peak and off-peak time periods can contribute towards reducing the peak, and can help avoid the need for new generation capacity. This analysis finds that AWU can reduce its electricity demand during peak periods by making use of reservoir capacity, i.e. by filling its reservoirs prior to peak time and draining them during peak periods. This proposed pumping schedule could save AWU up to 29% of its monthly electricity costs under current Austin Energy time-of-use rate (as opposed to flat rate) structures at the specific pump station analyzed as part of this research. Together, state-wide water utilities provide even more opportunities for the interconnected Electric Reliability Council of Texas' (ERCOTs) grid that are also evaluated in this research.Item Hydraulic fracturing optimization : experimental investigation of multiple fracture growth homogeneity via perforation cluster distribution(2016-05) Michael, Andreas; Olson, Jon E.; Balhoff, Matthew THydraulic fracturing is a reservoir stimulation technique used in the petroleum industry since 1947. High pressure fluid composed mainly of water generates cracks near the wellbore improving the surrounding permeability and enhancing the flow of oil and gas to the surface. Advances in hydraulic fracturing coupled with developments in horizontal drilling, have unlocked vast quantities of unconventional resources, previously believed impossible to be produced. Fracture creation induces perturbations in the nearby in-situ stress regime suppressing the initiation and propagation of other fractures. Neighboring fractures are affected by this stress shadow effect, causing them to grow dissimilarly and they receive unequal portions of the injected fluid. Numerical simulation models have shown that non-uniform perforation cluster distributions with interior fractures closer to the exterior ones can balance out these stress shadow effects, promoting more homogeneous multiple fracture growth compared to uniform perforation cluster distributions. In this work, laboratory-scale tests on three perforation configurations are performed on transparent specimens using distinctly colored fracturing fluids such that fracture growth can be observed. A normal faulting stress regime is replicated with the introduction of an overburden load in a confined space. The results have shown that uniform perforation spacing configurations yields higher degree of fracture growth homogeneity, as maximum spacing minimizes stress shadow effects, compared to moving the middle perforation closer to the toe, or heel of the horizontal well. The experiments also showed a proclivity to form one dominant fracture. Time delay, neglected in most theoretical modelling studies, between fracture initiations is found to be a key parameter and is believed to be one of the major factors promoting this dominant fracture tendency along with wellbore pressure gradients. Moreover, in several cases, the injected bypassed perforation(s) to generate fracture(s) downstream. Finally, the compressibility of the fracturing fluid triggered somewhat unexpected transient pressure behavior. The understanding of the stress shadow effects and what influences them could lead to optimization of hydraulic fracturing treatment design in terms of productivity and cost. Therefore, achieving more homogeneous multiple fracture growth patterns can be pivotal on the economic feasibility of several stimulation treatments.Item Improving electrical power grid resiliency and optimizing post-storm recovery using LiDAR and machine learning(2020-02-03) Davis, Michael Andrew, II; Bajaj, ChandrajitWhile many external factors influence resiliency, weather remains the single greatest threat to the electric power grid, and the impacts caused by significant storms can be long-lasting and widespread. When damage occurs, it is very costly to identify due to the vast size of electrical transmission and distribution circuits, which can span hundreds of miles. Pinpointing a failure in a circuit requires the expensive process of dispatching human teams to “walk the line” and physically inspect the circuit to identify damage. It is proposed that this problem can be optimized through automation, by leveraging flight vehicles, light detection and ranging (LiDAR) technology, and machine learning. The goals for this project are: 1) Investigate the feasibility of, and problems associated with, developing a system to remotely inspect electrical power transmission and distribution infrastructure with lidar. 2) Investigate the feasibility of developing an automated system to classify and detect damage to terrestrial transmission and distribution assets with lidar and artificial intelligence. 3) Develop a proof of concept of such a system, including a simulation of real-time lidar data collection and damage assessmentItem Invasion risk and impacts of a popular aquarium trade fish and the implications for policy and conservation management(2014-05) Dugan, Laura Elizabeth; Hendrickson, Dean; Parmesan, Camille, 1961-Invasive species, a top threat affecting global biodiversity, become invasive through a process including four stages: transport, establishment, spread, impact and integration. Species currently in this process provide opportunities to empirically derive the mechanisms driving each of these stages, make predictions based on these mechanisms and then to test these predictions. This research examines the current invaded distribution, potential invasion and community-level impacts of a popular aquarium trade fish (Hemichromis guttatus Günther, 1862) in an endemic hotspot, Cuatro Ciénegas, in Coahuila, México and discusses the policy and conservation management implications of these findings. In Chapter 1, the problem of invasive species, the study site and the focal species of this work are introduced. In Chapter 2, the critical thermal minimum and maximum temperature limits and temperature preference of H. guttatus are identified because temperature is hypothesized to be an important factor controlling this fish’s distribution. The results indicate that H. guttatus has a wide temperature tolerance range (a characteristic of a ‘good’ invader), that preference is a more informative metric for predicting invasion than absolute tolerances, and that resource-poor environments may promote searching behaviors that cause an invasive fish to increase its range. In Chapter 3, the results of a field survey are analyzed and temperature, pH, depth and the presence of vegetation are all found to be related to H. guttatus presence. Invasion risk of several as-of-yet uninvaded sites in Cuatro Ciénegas is assessed. In Chapter 4, competitive and predatory interactions of H. guttatus on an endemic, threatened cichlid (Herichthys minckleyi) and a macroinvertebrate community respectively are investigated. The results suggest that while H. guttatus does not directly impact H. minckleyi through competition in these conditions, it may inhibit reproduction and alter H. minckleyi’s behavior through aggressive interactions. In Chapter 5, all results are synthesized and a determination of the invasive status of H. guttatus in Cuatro Ciénegas is made. The results presented here will be useful in identifying areas with a high risk of invasion by this popular ornamental fish, thus allowing the implementation of policy and management actions to prevent or at least ameliorate the impacts of an invasion and will add to the growing knowledge of how invasive species affect native systems.Item Learning to write in (networked) public: children and the delivery of writing online(2014-12) Roach, Audra Katherine; Bomer, Randy; Hoffman, Jim; Maloch, Beth; Schallert, Diane; Hodgson, JustinThis investigation explored how three children (together with parents) developed networked publics that were diverse, well-connected, and powerful in the world. It was framed in response to calls in the field to better understand the new literacies young writers develop online and outside of school, and to increase literacy educators’ attention to the role of public audiences in writing and how writing is circulated. Performative case study methodology, ethnographic methods, and digital methods were employed to track and describe the online networks of three children (ages 11-13). These focal children were actively involved with their parents in social media, and had developed widespread networks with shared interests in children’s books and book reviews (Case 1), baseball (Case 2), and helping the homeless (Case 3). The children’s online networks were conceptualized as networked publics, drawing on Warner’s (2002) notion of publics as ongoing discursive relations among strangers, and on Actor-Network Theory’s notion of networks as assemblages of diverse interests that mobilize toward a common goal (Callon, 1986) and that develop stability in relation to ongoing circulations of texts (Latour, 1986; Spinuzzi, 2008). Research questions were framed broadly around the rhetorical canon of delivery [now digital delivery (Porter, 2009)], and were concerned with how writers distributed texts online, how those texts circulated, how the networked publics become more stable and powerful, and what instabilities children and parents had to negotiate in order to accomplish all of this. Data sources included interviews with 15 children and 28 adults, and fieldnotes observations of approximately 1,700 screen-captured webpages and other online artifacts. Findings showed that the young writers and their parents initiated and sustained networked publics through distribution practices that were oriented toward building trust; their texts displayed: interest, appreciation, reliability, service, credibility, and responsiveness. Both grassroots and commercial entities circulated texts in these networks, as they were sources of the ongoing renewal these different groups all needed in order to thrive. Sources of instability included conflicts over standards of writing quality, matters of profit, and the constancy of the demand to generate new interest and writing online. Children and their parents responded to these instabilities by welcoming and negotiating heterogeneous perspectives and partnerships. Implications of the study call for further research and teaching about the art of networked public discourse and digital delivery.Item Residential PVs and EVs: Before and After(0000-00-00) Uriarte, F. M.; Hebner, R. E.Power distribution systems are experiencing higher load levels, unbalanced distributed generation, a wealth of load diversity, and more uncorrelated events than ever before. To provide quantitative information regarding the changes, this paper contrasts the electrical state of the largest Smart Grid residential community in Austin, Texas before and after the proliferation of its PVs and EVs. This community is the research focus of the authors, local utilities, and many others attempting to hinder detrimental consequences of the uncontrolled, fast proliferation of residential assets on the grid. The authors use surface and filled contour plots to show new electrical footprints, and show its impact on transformer utilization, feeder demand, current unbalance, and distribution losses.Item Scaling and certifying symbolic execution(2016-12) Qiu, Rui, active 21st century; Khurshid, Sarfraz; Gligoric, Milos; Pasareanu, Corina S.; Perry, Dewayne E.; Yang, GuoweiSymbolic execution is a powerful, systematic program analysis approach that has received much visibility in the last decade. The key idea in symbolic execution is to explore all execution paths up to a bound on the path length, build path conditions that represent constraints on inputs that execute the corresponding paths, and solve the constraints using off-the-shelf constraint solvers to determine path feasibility (where possible). While systematic path exploration enables symbolic execution to find subtle bugs, scaling the approach remains a key challenge. Our thesis is that novel compositional, certifying, and distribution techniques can enhance the efficacy of symbolic execution. This dissertation designs, develops, and evaluates three techniques based on the primitives of composition, certification, and distribution in program analysis to enhance symbolic execution. Our composition technique CompoSE allows the overall symbolic execution results to be computed by composing intermediate results with respect to individual methods, rather than treating the entire program monolithically as is done traditionally. CompoSE first summarizes each method as a memoization tree that represents the key elements of symbolic execution of that method, and then uses these trees to efficiently replay the symbolic execution of the corresponding methods with respect to their calling contexts. The key novelty of CompoSE is that it allows composition in the presence of complex operations on the program heap. Our certification technique CertifiedSE allows symbolic execution analysis to be performed by one party, the producer, and utilized by another party, the consumer. The producer creates a certificate that can be checked efficiently by the consumer to validate the correctness of symbolic execution results. The key novelty of CertifiedSE is that it introduces the idea of certification in the context of symbolic execution, which enables a number of ways to enhance how symbolic execution is performed and used. Our distribution technique SynergiSE enhances symbolic execution in a novel two-fold integration approach. One, it integrates distributed analysis and constraint re-use to enhance symbolic execution using feasible ranges, which allows sharing of constraint solving results among different workers without communicating or sharing potentially large constraint databases (as required traditionally). Two, it integrates complementary techniques for test input generation, e.g., search-based generation and symbolic execution, for creating higher quality tests using unexplored ranges, which allows symbolic execution to re-use tests created by another technique for effective distribution of exploration of previously unexplored paths. The key novelty of Synergise is that it significantly reduces the amount of communication among different symbolic execution workers and enables an effective integration of heuristics-based and systematic approaches for test generation. We embody our techniques into prototypes based on the Symbolic PathFinder tool for analyzing Java programs. Experimental results using a variety of subjects show that our techniques can significantly improve symbolic execution.Item Social documentary in the era of the popular front : The Plow That Broke the Plains, alternative filmmaking, and the struggle for independent distribution in the United States, 1935-37(2015-05) Altenberg, Benjamin Creed; Fuller-Seeley, Kathryn; Stein, LauraIn the time before World War II in the United States, a generation was radicalized by the Great Depression and inspired to challenge cultural conventions across many forms of media. In the area of film, a peculiar instance of alternative production and distribution sprouted out of the United States government in the form of a 2-reel documentary entitled The Plow That Broke the Plains, originally released in 1936. Funded by a relief agency, directed by a man with no experience, and shot by radical leftist artists out of New York City, the film was an unusual challenge to the status quo of the prevailing classical Hollywood model. It was so jarring, in fact, that Hollywood studios denounced the effort publicly and prevented the mainstream theatres that they controlled from showing the picture. The following efforts to distribute the film in spite of this mainstream opposition allowed the film to be seen by an alternative set of audiences across multiple kinds of exhibition spaces, including educational assemblies and striking labor unions. Using a plethora of primary and secondary historical sources, as well as a framework developed by Chris Atton for studying alternative media, this thesis analyzes the production and distribution processes of the film to help elucidate how a work functioning outside of the dominant commercial industry could attain national recognition and reach audiences across urban, suburban, and rural areas of the country at a time when other such alternative cinematic endeavors never accessed many viewers outside of a bourgeois elite cultural sphere.Item Study of methane hydrate formation and distribution in Arctic regions : from pore scale to field scale(2011-08) Peng, Yao, 1983-; Bryant, Steven L.; Prodanović, Maša; DiCarlo, David; Sharma, Mukul M.; Flemings, PeterWe study hydrate formation and distribution in two scales. Pore-scale network modeling for drainage and imbibition and 1D field-scale sedimentological model are proposed for such purpose. The network modeling is applied in a novel way to obtain the possible hydrate and fluid saturations in the porous medium. The sedimentological model later uses these results to predict field-scale hydrate distribution. In the model proposed by (Behseresht et al., 2009a), gas charge in the reservoir firstly takes place when BGHSZ (Base of Gas Hydrate Stability Zone) is still above the reservoir. Methane gas migrates from deep source and is contained in the reservoir by the capillary barrier. The gas saturation distribution is determined by gas/water capillary pressure, and is modeled by network modeling of drainage. When gas charge is complete, the gas column in the reservoir is assumed to be disconnected from the deep source, and BGHSZ begins to descend. Hydrate formation is assumed to occur only at BGHSZ. At the microscopic scale it first occurs at the methane/water interface. A review of the possible modes of growth leads to the assumption that hydrate grows into the gaseous phase. It is assumed that the hydrate formation at the pore scale follows the path of imbibition process (displacement of gas phase by aqueous phase), and can be predicted by the network modeling of imbibition. Two scenarios, corresponding to slow and fast influx of water to the BGHSZ, are proposed to give the maximum and minimum hydrate saturations, respectively. The volume of hydrate is smaller than the total volume of gas and water that are converted at fixed temperature and pressure. Therefore, vacancy is created to draw free gas from below the BGHSZ and water into the BGHSZ. BGHSZ keeps descending and converting all the gas at BGHSZ into hydrate. The final hydrate profile has a characteristic pattern, in which a region of high hydrate saturation sits on top of a region with low hydrate saturation. This pattern agrees with the observation in Mount Elbert and Mallik sites. The low hydrate saturation in certain regions with good lithology shows that hydrate distribution is not only controlled by the quality of lithology, but also the gas redistribution during hydrate formation.Item Tango with the global, national, and local : new multi-functional organizations in the Chinese independent documentary ecosystem(2011-08) Yang, Jing; Schatz, Thomas, 1948-; Chang, Sung-sheng, 1951-Compared to the early days of China’s New Documentary Movement in the 1990s, Chinese independent documentary in the past decade has become more diverse in topic and style, thanks to technologies such as digital video cameras and the internet. Independent documentaries capture a fast-changing China in progress, and have thus drawn scholarly attention from cultural or social studies perspectives. However, industrial development in the past decade has often been neglected in favor of textual analysis of films. Since the marketization of independent documentaries in the 1990s was mainly through international film festivals, and a domestic industry has been lacking, it is easy to assume that Chinese independent documentarians today still have to follow the same path as their counterparts in the 1990s. However, my research on the Chinese independent documentary scene in Beijing in 2009 showed me a picture of a burgeoning domestic industry for independent documentaries, with a handful of newly emerged multi-functional independent film organizations practicing production, distribution and exhibition. Since a real industry has not yet formed, I use “ecosystem” instead of “industry” in the context of Chinese independent documentary. This study compares three representative organizations which are different from each other in nature and emphases, from their birth and evolution to their work and strategies. I argue that these organizations have created new possibilities and opportunities for today’s Chinese independent documentaries, through their different strategies in balancing themselves in a three-legged system of the global, national and local forces and resources.Item Tree ferns of Central Veracruz : harvest and conservation implications(2011-08) Vázquez-Domínguez, Othoniel; Doolittle, William Emery; Knapp, Gregory W.; Miller, Jennifer A.Tree ferns are listed as endangered species under Mexican law and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Despite this status, tree ferns are currently being harvested by rural communities, and sold in the form of handicrafts, traditional medicines, and household ornaments In the state of Veracruz, some authors argue that the harvesting of tree fern caudexes (trunks) to obtain a material made out of the fern’s adventitious roots called maquique poses a major threat to tree fern conservation. This thesis systematically explores the effect of harvesting activities on the distribution of tree fern species in the tropical montane cloud forest’s fragmented landscape using vegetative regeneration as a proxy for maquique harvesting. The study was conducted in El Zapotal in the municipality of Acajete and El Riscal in the municipality of Coatepec, two small communities with different land use histories. A census was performed at each site to georeference and document all tree fern individuals, including information on diameter, height and presence/absence of vegetative regenerations due to maquique harvesting per individual tree fern. Four species were present in the study: Alsophila firma, A. tryoniana, Cyathea bicrenata, and C. fulva. ArcGIS Desktop was used to calculate distances from individual tree ferns to trails and rivers, which were regarded as points of access for maquique harvesters. These data were used to infer how and whether maquique affects the distribution and abundance of tree fern species at the two studied sites. This study reports for the first time different forms of vegetative regenerations in Mexican tree fern species such as the resprouting of multiple branches from a single tree fern trunk and also documents different forms of harvesting like the “C cut”. Contrary to common conservation arguments, the study shows that tree ferns can continue to thrive even after a severe environmental modification, such as forest clearing and the establishment of tree plantations. Other results suggest that maquique harvesters operating clandestinely are more likely to target tree ferns with maquique closer to points of access (trails or rivers) rather than according to size. In the long run, this pattern of tree fern harvesting could modify the distribution of tree ferns as they are displaced from areas closer to human access, despite the ability of some tree fern species to regenerate in highly disturbed environments. The discovery of tree fern regenerative properties offers potential for the management of certain tree fern species as umbrella species for conservation in central Veracruz. It suggests that maquique harvesting might be sustainable given careful management and government regulation based on scientific data.Item Zero to sixty hertz : electrifying the transportation sector and enhancing the reliability of the bulk power system(2015-08) Legatt, Michael Elazar; Baldick, Ross; Webber, Michael EA revolution is underway in the energy sector. Traditional approaches for managing a bulk power system are beginning to give way to a "smart grid" world, in which controllers may have bidirectional communications, with engaged users. At the same time a second transformation has been underway and growing in strength, namely the transition from petroleum as a transportation fuel source towards natural gas for large fleet vehicles, and electricity for consumer vehicles. This thesis focuses primarily on the synergy between the "smart grid" and vehicle electrification transitions. Moving the transportation sector to electricity as a fuel source, at least in Texas, has a myriad of benefits: Charging an electric vehicle without significant growth in renewable or lower-emitting SOFC technologies leads to very significant (80% per mile, 58% per neighborhood) reductions in CO₂ emissions, as well as significant reductions in NO[subscript X] (41% per mile, 17% per neighborhood), PM₁₀ (73% / 62%), PM₂.₅ and UFPM (62% / 55%). SO[subscript X] levels rose by 37%, but could be mitigated with controlled EV charging strategies. Vehicle charging strategies also significantly improved the neighborhood's total emissions profile. Adding in distributed energy resources, microgrid generation and intelligent charging, when optimally allocated, can further reduce these emissions. Vehicle charging schemes that respond dynamically to distributed renewable generation can even be thought of as having zero emissions due to the continual balance of PV generation and EV load on the low side of the distribution transformer. This thesis argues that there may be additionally significant societal benefits by shifting vehicle transportation to electricity, likely far in excess of what could be achieved by controlling power plant emissions alone. Based on an analysis of the ERCOT region, this shift would be expected to produce significant cost reductions for overall energy, improve health (due primarily to the relocation of UFPM far away from major population centers), and lower societal costs. Further gains can be considered as electric vehicles are significantly more energy efficient than their ICE counterparts. Also, on a larger scale, it’s generally easier to reduce emissions from hundreds of fixed power plants than millions of moving ICE vehicles.