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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Civil Disobedience as a Radical Flank in the Mountain Valley Pipeline Resistance Movement

Baller, Cameron Reid 19 May 2023 (has links)
Communities of resistance are increasingly turning to radical tactics, including acts of civil disobedience, to fight back against encroaching fossil fuel infrastructure. The fight against the Mountain Valley Pipeline (MVP) is no exception. The MVP is a 303-mile long proposed fracked gas pipeline in Virginia and West Virginia. I apply radical flank effect (RFE) theory and the theory of movement dynamism to understand the role of civil disobedience, as a radical flank, in the MVP resistance movement. I contribute to the literature on RFEs by focusing primarily on how the radical flank of this movement has affected within-movement social dynamics, like trust, unity, and interpersonal relations. I rely on 15 semi-structured interviews with pipeline fighters, both those who have and have not participated in acts of civil disobedience, to gain insight into the use of civil disobedience, as a radical flank in the movement. This movement has used diverse tactics to challenge construction of the MVP, making it a strong case for understanding the role of radical tactics, and their relationship to moderate tactics. I find several positive RFEs (energizing effects, connecting effects, engaging effects, uniting effects, and movement outcome effects) and some potential negative RFEs (conflict/alienation, fear of consequences and organizational risks). I also find evidence of movement dynamism in the form of an ecosystem of tactics which emerged in the MVP resistance movement. Movement actors kept moderate and radical flanks publicly separate for strategic reasons while overlapping membership bridged the social dynamics of the movement, encouraging cohesion and collective movement identity. / Master of Science / Communities concerned about climate change are increasingly breaking the law in order to make their voices heard and stop dangerous coal, oil and natural gas projects. These actions are called civil disobedience and they have been used for decades in the United States, most prominently in the Civil Rights Movement. One such example in the fight against climate change is the resistance to the Mountain Valley Pipeline, a 303-mile long proposed natural gas pipeline in Virginia and West Virginia. I use social movement theories to understand the role that civil disobedience has played in the Mountain Valley Pipeline resistance movement. Specifically, I look at how the use of civil disobedience in this movement has affected the social dynamics of the movement, like trust, unity, or relationships in the movement. I spoke with 15 community members who have been active in fighting this pipeline to learn more. This movement has involved a wide range of different tactics, including civil disobedience, so it is a strong example to study for this research. My interviews with the community members revealed several positive effects as a result of the use of civil disobedience in the movement as well as a few potential risks/dangers. I also found that civil disobedience was able to work together with other types of tactics in a vibrant ecosystem that included mutual benefit. At the same time, I find that community members sought to keep some of the illegal tactics separate from more moderate tactics, like lawsuits or public comment submissions, in order to keep the moderate tactics safe. Despite this separation, I find that significant overlap of community members across different types of tactics was able to maintain a cohesive, common identity and unify people who were participating in different tactics, but fighting the same pipeline.
182

Improving the prediction of scour around submarine pipelines

Zhang, Z., Shi, B., Guo, Yakun, Chen, D. 29 November 2016 (has links)
Yes / Local scour around submarine pipelines can affect the stability of the pipeline. The accurate estimation of the scour around submarine pipelines has been a hot topic of research among marine engineers. This paper presents results from a numerical study of clear-water scour depth below a submarine pipeline for a range of the steady flow conditions. The flow field around the pipeline under scour equilibrium condition is numerically simulated by solving the Reynolds-Averaged Navier-Stokes (RANS) equations with the standard k-ε turbulence closure. The flow discharge through the scour hole for various flow conditions is investigated. The results are used to establish the relationship between the flow discharge and the maximum scour depth. Incorporated with the Colebrook-White equation, the bed shear stress is obtained and an iterative method is proposed to predict the scour depth around the submarine pipeline. The calculated scour depths using the present method agree well with the laboratory measurements, with the average absolute relative error being smaller than that using previous methods, indicating that the proposed method can be used to predict the clear-water scour around the submarine pipeline with satisfactory accuracy. / National Nature Science Fund of China (Grant No.50879084, 51279189), the Open Fund from the State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University (SKHL1302),China Scholarship Council, Public Projects of Zhejiang Province (2016C33095) and the Natural Science Fund of Zhejiang Province (LQ16E090004).
183

Investigation on scour protection of submarine piggyback pipeline

Yang, S., Shi, B., Guo, Yakun, Yang, L. 08 May 2019 (has links)
Yes / This paper presents the results of laboratory experiments and numerical simulations to investigate the effect of different piggyback pipeline configuration on the morphology of local seabed scour subject to steady currents. Piggyback pipeline configuration investigated includes the commonly used piggyback pipeline, namely a small pipe attached on the top of large pipe and new form of piggyback pipeline proposed in this study in which a small pipe is attached to the large pipe on the upstream and downstream side, respectively. Pressure gradient, drag coefficient, lift coefficient and scour extent around pipelines are measured and analyzed for a range of pipelines and current conditions. Results show that the vortex strength downstream of the commonly used piggyback pipeline is larger than that for a single as well as the new piggyback pipeline under the same condition. This new type piggyback pipeline can effectively reduce the depth and width of the scour hole. In particular, when the ratio of the small pipe diameter over the large pipe diameter is greater than 0.3, little scour under this new type piggyback pipeline occurs for the test conditions. The bed topography downstream of the pipe has also been altered to favor the backfill. / National Natural Science Foundation of China (No. 51279189).
184

Excavations and survey at Coats Hill, near Moffat, 1990-1

Dunwell, A.J., Armit, Ian, Ralston, I., Clarke, A. January 2000 (has links)
This report describes the results of the survey and sample excavations of small cairns, annular structures and other remains on Coats Hill, near Moffat. The difficulties of assessing the dates and functions of certain of the structures are discussed. The project formed part of the archaeological studies for the North Western Ethylene Pipeline (NWEP) Project for Shell Chemicals UK Ltd, which wholly funded the archaeological work and the publication of this report.
185

Comparison of Particle System Performance : In Object-Space and Image-Space Within a DirectX11 Implementation

Ohlson, Martin January 2024 (has links)
Background. Particle systems render groups of points in space that are used to add various effects to a scene. When rendering particles, there are various advantages and disadvantages for rendering an effect in either object-space or image-space. The former uses calculations in a 3D environment, while the latter adds particles to a 2D image. There is a lack of existing research to understand the trade-off in performance and in effort when applying these two techniques. Objectives. This thesis aims to compare the performance difference between particle systems in object-space versus image-space. The intent is to do this using a C++ DirectX11 implementation. Methods. The primary methodology of this thesis was an implementation complemented by a performance evaluation. Two particle systems were made to render the same particle effect. The systems were run at five different particle amounts and the FPS was recorded for 30 seconds while the simulations ran. Results. The data presented displays the average FPS recorded, with different line graphs for the various particle amounts. The results show an overall better performance of the O-system. Conclusions. While the O-system performed better, the various techniques and optimizations available to particle systems that render in image-space would allow avastly different result. This thesis would be well complemented with further research. It would also be furthered by comparing performance while additional geometry interacts with the particles.
186

Automatic detection of AI-generated source code in programming courses / Automatisk detektering av AI-genererad källkod i programmeringskurser

Pirntke, Erik, Rindebrant, Wictor January 2024 (has links)
Universities worldwide struggle with maintaining academic integrity due to the rise of advanced large language models (LLM) capable of generating flawless source code. Teachers need to be able to identify artificial intelligence (AI)-generated source code in student submissions accurately. There are already multiple different tools for detecting AI-generated content. Yet teachers are not using these tools. For this reason, this case study will focus on creating a prototype for automating the process of checking for AI-generated source code in submitted assignments in programming courses. Teachers at Linnaeus University (LNU) are using GitLab for submissions of programming assignments. The prototype in this case study will be created on GitLab and tested on submitted test assignments using the same structure utilized by teachers at LNU for their programming courses. The automated process will be accomplished using continuous integration (CI) pipelines on GitLab that will execute Python files that send and receive data to and from the AI-detection tool’s application programming interface (API). The received data will be represented on GitLab for teachers and students to see.
187

An integrated numerical model for wave-soil-pipeline interactions

Lin, Z., Guo, Yakun, Jeng, D-S., Liao, C.C., Rey, N. 03 November 2015 (has links)
Yes / An integrated Finite Element Method (FEM) model is proposed to investigate the dynamic seabed response for several specific pipeline layouts and to simulate the pipeline stability under waves loading. In the present model, the Reynolds-Averaged Navier-Stokes (RANS) equations are used to describe the wave motion in a fluid domain, while the seabed domain is described using the Biot’s poro-elastic theory. The interface between water and air is tracked by conservative Level Set method (LSM). The FEM and backward differentiation formula (BDF) are applied for spatial and temporal discretization respectively in the present model. One-way coupling is used to integrate flow and seabed models. The present model is firstly validated using several available laboratory experiments. It is then further extended to practical engineering applications, including the dynamic seabed response for the pipeline mounted on a flat seabed or inside a trench. The results show that the pipeline buried to a certain depth is better protected than that under partially buried in terms of transient liquefaction. / Energy Technology Partnership (ETP), Wood Group Kenny
188

Otimização da programação de curto prazo de duto bidirecional de derivados de petróleo. / Short-term scheduling optimization of derivative petroleum bidirectional pipeline.

Hassimotto, Marcelo Kenji 21 November 2007 (has links)
Sistemas dutoviários desempenham um papel fundamental na cadeia de suprimento da indústria de petróleo. Este tipo de sistema é responsável pelo transporte da maior parte do volume de petróleo e seus derivados. Sistemas de dutos transportam uma grande quantidade de diferentes tipos de petróleo e seus derivados a custo mais baixo que outros tipos de modais. Dutos interligam campos de produção de petróleo, portos, refinarias, centros de distribuição (ou depósitos), e mercado consumidor. O problema estudado neste trabalho é baseado em um sistema que é composto por uma refinaria que pode transferir vários produtos para um terminal (depósito) através de um único duto. Os produtos são conjuntos de derivados de petróleo que devem ser transferidos da refinaria para o terminal ou do terminal para a refinaria. Ambos, refinaria e terminal estão conectados a outras refinarias, terminais e mercados consumidores e com isto formam uma complexa rede de dutos. Por outro lado há um conjunto de demandas externas e internas. Esta última demanda decorre da necessidade de processamento de produtos intermediários que são misturas compostas de várias correntes intermediárias, tais como diluentes de óleos combustíveis, propano intermediário, e diesel intermediário. Com o objetivo de obter vantagens sobre a estrutura da rede de transporte, torna-se benéfica e mesmo necessária a operação do duto em ambas as direções para atender tanto à demanda externa quanto à interna. O objetivo deste trabalho é desenvolver um modelo matemático para a programação de um sistema de poliduto. A formulação para a programação deve considerar a possibilidade de trocar o sentido do poliduto. Neste contexto, a programação de um poliduto envolve decisões tais como sentido de operação, quantidade, temporização e seqüências de produtos, com objetivo de obter uma solução ótima, considerando todas as restrições de demanda, perfil de produção, estoques e custos. O modelo de programação é baseado em uma representação de tempo discreto e composto da área de tancagem da refinaria, um terminal, e um poliduto. Além disto o duto é dividido em segmentos de volumes iguais como em Rejowski Jr e Pinto (2003). As principais variáveis de decisão são a direção da movimentação do duto (da refinaria para terminal ou do terminal para refinaria) e o que está sendo movimentado a cada intervalo. Estas decisões são formuladas através de uma representação disjuntiva. As disjunções são transformadas em uma formulação baseada em programação matemática mista-inteira, a partir da representação Convex-hull. A função objetivo considera os custos de estocagem, movimentação e interface de produtos. O modelo é aplicado inicialmente a um caso protótipo e posteriormente aplicado a um sistema real composto pelos terminais de São Sebastião e Guararema e o poliduto OSPLAN. Neste caso ao todo quatro famílias de produtos são transportadas: gasolina, querosene, nafta e diesel. A programação é gerada para o período de uma semana. / Pipeline systems play a major role in the supply chain of the petroleum industry. These systems are responsible for the transportation of most of the crude oil and petroleum derivatives. Pipeline systems transfer large amounts of different petroleum types and their products at a lower cost than any other transportation mode. Pipelines interconnect oil fields, ports, refineries, distribution centers (or depots), and consumer markets. The problem addressed is this work is based on a system that is composed by an oil refinery that must transfer multiple products through a single pipeline connected to one depot. The products are a set of petroleum derivatives that must be either transported from the refinery to the depot or from the depot to the refinery. Both depot and refinery also connect other refineries as well as other depots and customers, thus forming a complex transportation network. On the other hand, there are several demands that arise either from external customers or from refineries. The latter demand is due from the need of processing intermediate streams with components mixtures such as diluents, propane and diesel. In order to take advantage of the structure of the transportation network, it becomes beneficial and even necessary to operate the pipeline in both directions so that internal and external demands are satisfied. The objective of this work is to develop a mathematical model for the short term scheduling of a multiproduct pipeline system. The scheduling formulation must account for the bidirectionality of the multiproduct pipeline. In this context, the scheduling a multiproduct pipeline involves the from-to decision, the product amounts, their sequence and timing, in the optimal sense, considering all constrains on demands, production rates, inventories, and costs. The scheduling model is based on a discrete time representation and is composed by one refinery tank farm, one depot and one multiproduct pipeline. Moreover, the pipeline is divided into segments of equal volume, as in Rejowski Jr and Pinto (2003). The main decisions variables are the directions of transfer (refinery to depot or depot to refinery) and the types of products at each time interval. These decisions are formulated with a disjunctive representation. The disjunctions are represented in mixed integer formulation based on the convex-hull approach. The objective function involves inventory, transfer and product interface costs. The model is first applied to a prototype case and after applied to a real-world system that is composed of the São Sebastião and Guararema depot and the OSPLAN pipeline. Overall four families of products are transported: gasoline, kerosene, naphtha and oil diesel. These are scheduled over a period of one week.
189

Processamento de vídeo estereoscópico em tempo real para extração de mapa de disparidades / Real-time disparity map extraction in a dual head stereo vision system

Calin, Gabriel 18 April 2007 (has links)
A análise em tempo real de pares de imagens estereoscópicas para extração de características dimensionais da cena tem apresentado crescente interesse, possibilitando robusta navegação robótica e identificação de objetos em cenários dinâmicos. A presente dissertação propõe um método que emprega a análise pixel a pixel e observação de janelas, em pares de imagens estereoscópicas, para extração de denso mapa de disparidades. A arquitetura de processamento proposta é única em sua constituição, misturando elementos de processamento concorrente e seqüencial. O algoritmo estrutura-se em processamento pipeline, permitindo sua implementação em dispositivos de lógica programável e obtenção de resultados em tempo real. / Real-time analysis of stereo images for extraction of dimensional features has been focus of great interest, providing means for autonomous robot navigation and identification of objects in dynamic environments. This work describes a method based in pixel-to-pixel and windows based matching analysis, in stereo images, for constructing dense disparity maps. The proposed processing structure is unique, mixing concurrent and sequential elements. Pipelines structure is employed, targeting implementation in FPGA devices and enabling real-time results.
190

[en] RELIEF TEXTURES USING PER PIXEL LIGHTING AND PARALLEL PROCESSING / [pt] TEXTURAS COM RELEVO UTILIZANDO ILUMINAÇÃO POR PIXEL E PROCESSAMENTO PARALELO

FRANCISCO MAURO ALVES FONSECA 19 March 2004 (has links)
[pt] A principal motivação para realização deste trabalho é verificar a viabilidade de uso da técnica de mapeamento de textura com relevo em aplicações que exijam interação em tempo real como, por exemplo, jogos eletrônicos. Esta dissertação apresenta uma extensão ao mapeamento de textura com relevo que suporta a representação de efeitos dependentes do ponto de vista e da direção de iluminação, que antes não eram possíveis de serem representados. Além disso, propõe uma forma de paralelizar tal mapeamento entre CPU e GPU (Graphic Processor Unit), utilizando-se para isto da tecnologia de Hyper-Threading. Nesta nova abordagem, cada amostra pertencente a uma textura com relevo é aumentada para incluir três valores escalares representando o vetor normal à superfície reproduzida pela textura. Desta forma, o cálculo de iluminação pode ser efetuado por pixel. A paralelização do processo de mapeamento de textura com relevo demonstra-se favorável uma vez que são obtidos ganhos de até 37% em relação ao tempo de processamento da abordagem convencional. / [en] The main motivation for this work is to verify the feasibility of using relief texture mapping in high-demand real-time applications, such as computer games. This dissertation presents an extension to relief texture mapping that supports the representation of effects that depend of viewpoint and illumination direction, which could not be represented with previous techniques. Moreover, it proposes a way to parallelize relief texture mapping between CPU and GPU, using Hyper-Threading technology. In this new approach, each element that belongs to a relief texture is augmented to include three scalar values representing the normal vector of the reproduced surface. So, the illumination can be calculated per pixel. In the proposed approach, the parallelization of the relief texture mapping represents an acceleration of up to 37% when compared to conventional techniques.

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