Dissertations / Theses on the topic 'Electrically large analysis'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Electrically large analysis.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Keghie, Jules Alliance Fernand [Verfasser]. "Simplified Analysis of Electrically Large Multi-room Systems / Jules Alliance Fernand Keghie." Aachen : Shaker, 2014. http://d-nb.info/1050342194/34.
Full textZhao, Kezhong. "A domain decomposition method for solving electrically large electromagnetic problems." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1189694496.
Full textTseng, Huan-Wan. "Hybrid analysis of em radiation and scattering by composite slot-blade cavity backed antennas on the surface of electrically large smooth convex cylinders /." The Ohio State University, 1998. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487949508371203.
Full textZhang, Richard Yi. "Robust stability analysis for large-scale power systems." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/108846.
Full textThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 145-154).
Innovations in electric power systems, such as renewable energy, demand-side participation, and electric vehicles, are all expected to increase variability and uncertainty, making stability verification more challenging. This thesis extends the technique of robust stability analysis to large-scale electric power systems under uncertainty. In the first part of this thesis, we examine the use of the technique to solve real problems faced by grid operators. We present two case studies: small-signal stability for distributed renewables on the IEEE 118-bus test system, and large-signal stability for a microgrid system. In each case study, we show that robust stability analysis can be used to compute stability margins for entire collections of uncertain scenarios. In the second part of this thesis, we develop scalable algorithms to solve robust stability analysis problems on large-scale power systems. We use preconditioned iterative methods to solve the Newton direction computation in the interior-point method, in order to avoid the O(n6) time complexity associated with a dense-matrix approach. The per-iteration costs of the iterative methods are reduced to O(n3) through a hierarchical block-diagonal-plus-low-rank structure in the data matrices. We provide evidence that the methods converge to an [epsilon]-accurate solution in O(1=[square root of ] [epsilon]) iterations, and characterize two broad classes of problems for which the enhanced convergence is guaranteed.
by Richard Yi Zhang.
Ph. D.
Hu, Xin 1979. "Full-wave analysis of large conductor systems over substrate." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/35597.
Full textIncludes bibliographical references (leaves 137-145).
Designers of high-performance integrated circuits are paying ever-increasing attention to minimizing problems associated with interconnects such as noise, signal delay, crosstalk, etc., many of which are caused by the presence of a conductive substrate. The severity of these problems increases as integrated circuit clock frequencies rise into the multiple gigahertz range. In this thesis, a simulation tool is presented for the extraction of full-wave interconnect impedances in the presence of a conducting substrate. The substrate effects are accounted for through the use of full-wave layered Green's functions in a mixed-potential integral equation (MPIE) formulation. Particularly, the choice of implementation for the layered Green's function kernels motivates the development of accelerated techniques for both their 3D volume and 2D surface integrations, where each integration type can be reduced to a sum of D line integrals. In addition, a set of high-order, frequency-independent basis functions is developed with the ability to parameterize the frequency-dependent nature of the solution space, hence reducing the number of unknowns required to capture the interconnects' frequency-variant behavior.
(cont.) Moreover, a pre-corrected FFT acceleration technique, conventional for the treatment of scalar Green's function kernels, is extended in the solver to accommodate the dyadic Green's function kernels encountered in the substrate modeling problem. Overall, the integral-equation solver, combined with its numerous acceleration techniques, serves as a viable solution to full-wave substrate impedance extractions of large and complex interconnect structures.
by Xin Hu.
Ph.D.
Palmer, Nathan Patrick. "Data mining techniques for large-scale gene expression analysis." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/68493.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (p. 238-256).
Modern computational biology is awash in large-scale data mining problems. Several high-throughput technologies have been developed that enable us, with relative ease and little expense, to evaluate the coordinated expression levels of tens of thousands of genes, evaluate hundreds of thousands of single-nucleotide polymorphisms, and sequence individual genomes. The data produced by these assays has provided the research and commercial communities with the opportunity to derive improved clinical prognostic indicators, as well as develop an understanding, at the molecular level, of the systemic underpinnings of a variety of diseases. Aside from the statistical methods used to evaluate these assays, another, more subtle challenge is emerging. Despite the explosive growth in the amount of data being generated and submitted to the various publicly available data repositories, very little attention has been paid to managing the phenotypic characterization of their samples (i.e., managing class labels in a controlled fashion). If sense is to be made of the underlying assay data, the samples' descriptive metadata must first be standardized in a machine-readable format. In this thesis, we explore these issues, specifically within the context of curating and analyzing a large DNA microarray database. We address three main challenges. First, we acquire a large subset of a publicly available microarray repository and develop a principled method for extracting phenotype information from freetext sample labels, then use that information to generate an index of the sample's medically-relevant annotation. The indexing method we develop, Concordia, incorporates pre-existing expert knowledge relating to the hierarchical relationships between medical terms, allowing queries of arbitrary specificity to be efficiently answered. Second, we describe a highly flexible approach to answering the question: "Given a previously unseen gene expression sample, how can we compute its similarity to all of the labeled samples in our database, and how can we utilize those similarity scores to predict the phenotype of the new sample?" Third, we describe a method for identifying phenotype-specific transcriptional profiles within the context of this database, and explore a method for measuring the relative strength of those signatures across the rest of the database, allowing us to identify molecular signatures that are shared across various tissues ad diseases. These shared fingerprints may form a quantitative basis for optimal therapy selection and drug repositioning for a variety of diseases.
by Nathan Patrick Palmer.
Ph.D.
Ford, Logan H. "Large-scale acoustic scene analysis with deep residual networks." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/123026.
Full textThesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2019
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 63-66).
Many of the recent advances in audio event detection, particularly on the AudioSet dataset, have focused on improving performance using the released embeddings produced by a pre-trained model. In this work, we instead study the task of training a multi-label event classifier directly from the audio recordings of AudioSet. Using the audio recordings, not only are we able to reproduce results from prior work, we have also confirmed improvements of other proposed additions, such as an attention module. Moreover, by training the embedding network jointly with the additions, we achieve a mean Average Precision (mAP) of 0.392 and an area under ROC curve (AUC) of 0.971, surpassing the state-of-the-art without transfer learning from a large dataset. We also analyze the output activations of the network and find that the models are able to localize audio events when a finer time resolution is needed. In addition, we use this model in exploring multimodal learning, transfer learning, and realtime sound event detection tasks.
by Logan H. Ford.
M. Eng.
M.Eng. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science
Sridharan, Ramesh. "Visualization and analysis of large medical image collections using pipelines." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/99849.
Full textTitle as it appears in MIT Commencement Exercises program, June 5, 2015: Visualization and analysis of computational pipelines for large medical image collections. Cataloged from PDF version of thesis.
Includes bibliographical references (pages 80-100).
Medical image analysis often requires developing elaborate algorithms that are implemented as computational pipelines. A growing number of large medical imaging studies necessitate development of robust and flexible pipelines. In this thesis, we present contributions of two kinds: (1) an open source framework for building pipelines to analyze large scale medical imaging data that addresses these challenges, and (2) two case studies of large scale analyses of medical image collections using our tool. Our medical image analysis pipeline construction tool, PipeBuilder, is designed for constructing pipelines to analyze complex data where iterative refinement and development are necessary. We provide a lightweight scripting framework that enables the use of existing and novel algorithms in pipelines. We also provide a set of tools to visualize the pipeline's structure, data processing status, and intermediate and final outputs. These visualizations enable interactive analysis and quality control, facilitating computation on large collections of heterogeneous images. We employ PipeBuilder first to analyze white matter hyperintensity in stroke patients. Our study of this cerebrovascular pathology consists of three main components: accurate registration to enable data fusion and population analysis, segmentation to automatically delineate pathology from the images, and statistical analysis to extract clinical insight using the images and the derived measures. Our analysis explores the relationship between the spatial distribution, quantity, and growth of white matter hyperintensity. Our next application of PipeBuilder is to a neuroimaging study of Alzheimer's patients, where we explicitly characterize changes over time using longitudinal data. As with the previous application, we introduce a workflow that involves registration, segmentation, and statistical analysis. Our registration pipeline aligns the large, heterogeneous group of populations while still accurately characterizing small changes in each patient over time. The statistical analysis exploits this alignment to explore the change in white matter hyperintensity over time.
by Ramesh Sridharan.
Ph. D.
Lucas, Christopher G. "Patent semantics : analysis, search and visualization of large text corpora." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/33146.
Full textIncludes bibliographical references (leaves 47-48).
Patent Semantics is system for processing text documents by extracting features capturing their semantic content, and searching, clustering, and relating them by those same features. It is set apart from existing methodologies by combining a visualization scheme that integrates retrieval and clustering, providing a variety of ways to find and relate documents depending on their goals. In addition, the system provides an explanatory mechanism that makes the retrieval an understandable process rather than a black box. The domain in which the system currently works is biochemistry and molecular biology patents but it is not intrinsically constrained to any document set.
by Christopher G. Lucas.
M.Eng.and S.B.
Gorham, LeRoy A. "Large Scene SAR Image Formation." Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1452031174.
Full textNovak, Erik Lowell 1971. "Measurement and analysis optimization of large aperture laser Fizeau interferometer." Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/282616.
Full textVatne, Åshild. "Analysis of Large Scale Adoption of Electrical Vehicles and Wind Integration in Nord-Trøndelag." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elkraftteknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18989.
Full textLandivar, Chávez José Luis. "Complexity cost analysis in a large product line." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/38551.
Full textIncludes bibliographical references (p. 73).
Hewlett-Packard's Industry Standard Servers (ISS) organization offers a large variety of server computers and accessories. The large range of options available to its customers gives way to complex processes and less than optimal resource usage. In the work presented here, a method for quantifying the costs associated with these effects is reviewed and applied to the current ISS offering. Several areas for investigation are identified including Research and Development, Sales and Marketing, Materials, Inventory, Organizational, amongst other costs that erode profits. Each area is explored through interviews and detailed modeling to arrive to a cost estimate. The end goal for estimating the costs associated with complexity is to establish a simple process for evaluating the "real" profitability of a new product introduction (NPI). Such process is enabled by implementing a set of complexity guidelines through the use of a complexity cost calculator. The end result is that HP's ISS division could see savings in the millions of dollars once the program is implemented. In the end, a set of wide reaching conclusions are drawn from the study to assist in future complexity cost analyses.
by José Luis Landivar Chávez.
M.B.A.
S.M.
Cooper, Lee Alex Donald. "High Performance Image Analysis for Large Histological Datasets." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1250004647.
Full textTan, Vincent Yan Fu. "Large-deviation analysis and applications Of learning tree-structured graphical models." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/64486.
Full textThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 213-228).
The design and analysis of complexity-reduced representations for multivariate data is important in many scientific and engineering domains. This thesis explores such representations from two different perspectives: deriving and analyzing performance measures for learning tree-structured graphical models and salient feature subset selection for discrimination. Graphical models have proven to be a flexible class of probabilistic models for approximating high-dimensional data. Learning the structure of such models from data is an important generic task. It is known that if the data are drawn from tree-structured distributions, then the algorithm of Chow and Liu (1968) provides an efficient algorithm for finding the tree that maximizes the likelihood of the data. We leverage this algorithm and the theory of large deviations to derive the error exponent of structure learning for discrete and Gaussian graphical models. We determine the extremal tree structures for learning, that is, the structures that lead to the highest and lowest exponents. We prove that the star minimizes the exponent and the chain maximizes the exponent, which means that among all unlabeled trees, the star and the chain are the worst and best for learning respectively. The analysis is also extended to learning foreststructured graphical models by augmenting the Chow-Liu algorithm with a thresholding procedure. We prove scaling laws on the number of samples and the number variables for structure learning to remain consistent in high-dimensions. The next part of the thesis is concerned with discrimination. We design computationally efficient tree-based algorithms to learn pairs of distributions that are specifically adapted to the task of discrimination and show that they perform well on various datasets vis-`a-vis existing tree-based algorithms. We define the notion of a salient set for discrimination using information-theoretic quantities and derive scaling laws on the number of samples so that the salient set can be recovered asymptotically.
by Vincent Yan Fu Tan.
Ph.D.
Preciado, Víctor Manuel. "Spectral analysis for stochastic models of large-scale complex dynamical networks." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45873.
Full textIncludes bibliographical references (p. 179-196).
Research on large-scale complex networks has important applications in diverse systems of current interest, including the Internet, the World-Wide Web, social, biological, and chemical networks. The growing availability of massive databases, computing facilities, and reliable data analysis tools has provided a powerful framework to explore structural properties of such real-world networks. However, one cannot efficiently retrieve and store the exact or full topology for many large-scale networks. As an alternative, several stochastic network models have been proposed that attempt to capture essential characteristics of such complex topologies. Network researchers then use these stochastic models to generate topologies similar to the complex network of interest and use these topologies to test, for example, the behavior of dynamical processes in the network. In general, the topological properties of a network are not directly evident in the behavior of dynamical processes running on it. On the other hand, the eigenvalue spectra of certain matricial representations of the network topology do relate quite directly to the behavior of many dynamical processes of interest, such as random walks, Markov processes, virus/rumor spreading, or synchronization of oscillators in a network. This thesis studies spectral properties of popular stochastic network models proposed in recent years. In particular, we develop several methods to determine or estimate the spectral moments of these models. We also present a variety of techniques to extract relevant spectral information from a finite sequence of spectral moments. A range of numerical examples throughout the thesis confirms the efficacy of our approach. Our ultimate objective is to use such results to understand and predict the behavior of dynamical processes taking place in large-scale networks.
by Víctor Manuel Preciado.
Ph.D.
Chen, Yu Ju. "A comprehensive electromagnetic analysis of AC losses in large superconducting cables." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/41418.
Full textWebster, Mort David. "Analysis of uncertainty in large models with application to climate policy." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/11028.
Full textIncludes bibliographical references (p. 115-118).
by Mort David Webster.
M.S.
Janpugdee, Panuwat. "An Efficient Discrete Fourier Transform Based Ray Analysis of Large Finite Planar Phased Arrays." The Ohio State University, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=osu1392817276.
Full textShah, Shahil. "Small and Large Signal Impedance Modeling for Stability Analysis of Grid-connected Voltage Source Converters." Thesis, Rensselaer Polytechnic Institute, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10786614.
Full textInteractions between grid-connected converters and the networks at their terminals have resulted in stability and resonance problems in converter-based power systems, particularly in applications ranging from wind and PV farms to electric traction and HVDC transmission networks. Impedance-based modeling and analysis methods have found wide acceptance for the evaluation of these resonance problems.
This thesis presents small and large signal impedance modeling of grid-connected single and three phase voltage source converters (VSC) to enable the analysis of resonance conditions involving multiple frequency components, and both the ac and dc power systems at the VSC terminals. A modular impedance modeling approach is proposed by defining the VSC impedance as transfer matrix, which captures the frequency cross-coupling effects and also the coupling between the ac and dc power systems interfaced by the VSC. Ac and dc impedance models are developed for a VSC including the reflection of the network on the other side of the VSC. Signal-flow graphs for linear time-periodic (LTP) systems are proposed to streamline and visually describe the linearization of grid-connected converters including the frequency cross-coupling effects. Relationships between the impedance modeling in dq, sequence, and phasor domains are also developed. The phasor-domain impedance formulation links the impedance methods with the phasor-based state-space modeling approach generally used for bulk power systems. A large-signal impedance based method is developed for predicting the amplitude or severity of resonance under different grid conditions. The small-signal harmonic linearization method is extended for the large-signal impedance modeling of grid-connected converters. It is shown that the large-signal impedance of a converter is predominantly shaped by hard nonlinearities in the converter control system such as PWM saturation and limiters.
This thesis also deals with the problem of synchronizing a generator or microgrid with another power system. A VSC-based synchronizer is proposed for active phase synchronization and a distributed synchronization method is developed for microgrids.
Dey, Sourav. "Large-Signal Analysis of Buck and Interleaved Buck DC-AC Converters." Wright State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wright1409578634.
Full textJiao, Yu Ming. "MPI parallel computing on eigensystems of small signal stability analysis for large interconnected power grids." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=95151.
Full textL'analyse des valeurs propres est largement utilisée dans les études de stabilité des réseaux électriques. En utilisant les ordinateurs personnels disponibles aujourd'hui, le calcul de la totalité des valeurs propres de plusieurs grands réseaux électriques interconnectés requiert beaucoup de temps. Étant donné que les lignes de transport d'électricité sont connectées et déconnectées et que les charges ne cessent de varier, le suivi des valeurs propres en temps réel nécessite des calculs en parallèles. Récemment, une méthode de calcul en parallèle des valeurs propres, la Break et Bind (B & B), a été proposée par le Dr. H. M. Banakar à l'Université McGill. Cette méthode voit la connexion de deux sous-réseaux isolés comme étant équivalent à une modification de rang un de la matrice de raideur et considère les deux sous-réseaux comme une entité entière. La recherche de cette thèse consiste à implanter la méthode B & B avec une programmation parallèle en #C basé sur l'interface Message Passing Interface (MPI). Le code de programmation développé en MPI a été exécuté avec des superordinateurs - Krylov de CLUMEQ et Mammouth série II de RQCHP. Les résultats des tests ont démontrés que les valeurs propres d'un système composé d'environ 4,000 alternateurs peuvent être calculées à l'intérieur de deux secondes.
Shisha, Samer. "Analysis of Inverter-fed Losses on the Solid Rotor of Large-scale Synchronous Machines." Licentiate thesis, KTH, Elektriska maskiner och effektelektronik (stängd 20110930), 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-64142.
Full textWang, Xiaochuan. "A Domain Decomposition Method for Analysis of Three-Dimensional Large-Scale Electromagnetic Compatibility Problems." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1338376950.
Full textPlanthaber, Gary Lee Jr. "MODBASE : a SciDB-powered system for large-scale distributed storage and analysis of MODIS earth remote sensing data." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/77035.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (p. 80-81).
MODBASE, a collection of tools and practices built around the open source SciDB multidimensional data management and analytics software system, provides the Earth Science community with a powerful foundation for direct, ad-hoc analysis of large volumes of Level-1B data produced by the NASA Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. This paper details the reasons for building the MODBASE system, its design and implementation, and puts it to the test on a series of practical Earth Science benchmarks using standard MODIS data granules.
by Gary Lee Planthaber, Jr.
M.Eng.
Sakr, Daniel. "Smart Grid deployment and use in a large-scale demonstrator of the Smart and Sustainable City (SunRise) : comprehensive analysis of the electrical consumption." Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10088/document.
Full textThe Smart City and Smart Grids constitute a great opportunity to meet the environmental challenges and to build inclusive cities that focus on the quality of life of citizens. However, these concepts are complex and recent. Their implementation requires learning from large experimentations. This work concerns this issue. It is carried within the large-scale demonstrator of the Smart City (SunRise) which is conducted at the Scientific Campus of the University of Lille. It includes three parts:The first part focuses on literature review of researches and achievements in the field of the Smart City and Smart Grids. It presents the city challenges such as the population growth, energy consumption, greenhouse emission and climate change. Then it discusses the digital mutation and its potential role in transforming the City into a Smart City and the conventional Electrical Grid into a Smart Grid. The second part describes the Electrical Grid of the Scientific Campus. It presents the project SunRise, that consists in the construction of a demonstrator of smart urban networks at the Scientific Campus, which is equivalent of a town with around 25 000 inhabitants. Then, it presents the electrical system of the campus as well as its management.The last part concerns analysis of the electrical consumption of the campus. It presents the methodology developed for data analysis including (i) record of the electrical consumption and transmission to the server, (ii) Data transmission, (iii) Data cleaning, (iv) construction of buildings’ consumption profiles and consumption analysis. This methodology is applied for analysis of the global consumption of the campus and three buildings
Jimenez, Saldana Cristhian Carim. "Large Scale Analysis of Massive Deployment of Converter-based Generation equipped with Grid- forming Strategies." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-292690.
Full textFör att minska koldioxidutsläppet och uppnå energimålen med avseende på hållbarhet krävs integrering av hållbara energikällor. Därmed, under de föregående och kommande åren kommer stort fokus riktas mot forskning kring ökad penetration av kraftelektronikomriktare i kraftsystemet. När kraftelektronikomriktare ersätter traditionella generationsenheter uppkommer nya utmaningar och problem som behöver lösas för att upprätthålla systemets stabilitet och pålitlighet med avseende på tillvägagångssätt för systemansvariga för överföringssystemet. Avhandlingens huvudmål är att analysera och implementera strömbegränsande metoder för kraftelektronikomriktare av typen voltage source converters med en nätformande (”grid- forming”) funktionalitet. Strömbegränsaren ska säkerställa att kraftelektronikomriktaren skyddas under allvarliga transienta händelser och att kraftelektronikomriktaren förblir ansluten till nätet under händelsen. Modellen av kraftelektronikomriktaren med nätformande egenskaper är beskrivna tillsammans med nätformande kontrollstrategier, virtuella synkronmaskniner (VSM) och användande av avsändande virtuell oscillerande kontroll i den yttre slingan. Den låga trögheten och noll-tröghetssystemet i IEEE 9-Bus test-system visade sig vara motståndskraftig mot trefasfel eftersom testsystemets beteende visade varken signifikanta oscillationer under och efter felet eller märkbar förändring i dess prestanda beroende på var felet inträffade. I denna testsystemsmodell var strömbegränsande tekniker validerade och de analyserande resultaten visade på god effektivitet för strömmen och för frekvensen. Hydro-Québec nätverks-modellen användes för att få en mer praktisk inriktning med hänsyn till beteendet hos strömbegränsarna där olika strategier har använts. Felpositionen och andelen av kraftelektronikomriktare i energigenereringen var två huvudsakliga scenarion, där de föreslagna kontrollstrategierna för att begränsa strömmen fungerade men kräver samtidigt att en lämplig kontroll för att behålla systemets stabilitet.
Rahman, Brian M. "Sensor Placement for Diagnosis of Large-Scale, Complex Systems: Advancement of Structural Methods." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1562859497638274.
Full textHawash, Maher Mofeid. "Methods for Efficient Synthesis of Large Reversible Binary and Ternary Quantum Circuits and Applications of Linear Nearest Neighbor Model." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/1090.
Full textHenriet, Simon. "On solving the non intrusive load monitoring problem in large buildings : analyses, simulations and factorization based unsupervised learning." Electronic Thesis or Diss., Institut polytechnique de Paris, 2020. http://www.theses.fr/2020IPPAT007.
Full textWith the increasing awareness about the problem of climate change and the high level of energy consumption, a need for energy efficiency has emerged especially for electric power consumptions in buildings. To spur energy savings, industrials have been looking for measurement methods to monitor power consumptions. Appliance load monitoring has thus become an active research field. Monitoring and understanding the electrical consumption of appliances can also be useful for predictive maintenance, power quality analyses, demand forecasting or occupancy detection. Thirty years ago, a method called Non Intrusive Load Monitoring (NILM) has been introduced. It consists of estimating individual appliance energy consumptions from the measurement of the total consumption of the building. Its main advantage over traditional sub-metering methods is to use a single electric power meter at the main breaker of the building and then use a disaggregation algorithm to separate the contributions of each appliance. The goal of this thesis is to address the algorithmic challenge offered by NILM. The NILM problem can be formulated as a source separation problem, where the sources are the individual electric consumptions and the mixed observation is simply the sum of individual consumptions. Its main difficulties are: (i) the standardization of the formulation, (ii) the ill-posedness of the problem, (iii) the lack of knowledge and (iv) the machine learning algorithm design. All our contributions follow from the principal objective that is to solve the NILM problem for huge systems such as commercial or industrial buildings using high frequency current and voltage measurements. However, houses and the specific equipment found inside these buildings are not excluded of the study. This thesis is split into two parts.In the first part, we tackle the lack of knowledge and datasets for NILM in commercial buildings. First of all, the NILM community has mostly focused on both residential NILM application and using low frequency data provided by power meter installed by utility providers. To tackle the lack of knowledge on higher frequency data and on other kind of buildings such as commercial or industrial installations, we propose a statistical analysis based on public and private datasets. Our study on the rank of current matrix conducted for individual devices will serve as the base of a new device taxonomy and to prior assumptions on the rest of this thesis. Secondly, we address the lack of datasets especially for commercial buildings by developping an algorithm for generating synthetic current data based on a modelization of the current flowing through an electrical device. To encourage research on commercial buildings we release a synthesized dataset called SHED that can be used to evaluate NILM algorithms.In the second part, we deal with the NILM software challenges by exploring unsupervised source separation techniques. To overcome the unaddressed difficulties of processing high frequency current signals that are measured in large buildings, we propose a novel technique called Independent-Variation Matrix Factorization (IVMF), which expresses an observation matrix as the product of two matrices: the "signature" and the "activation". Motivated by the nature of the current signals, it uses a regularization term on the temporal variations of the activation matrix and a positivity constraint, and the columns of the signature matrix are constrained to lie in a specific set. To solve the resulting optimization problem, we rely on an alternating minimization strategy involving dual optimization and quasi-Newton algorithms. IVMF is the first proposed algorithm especially designed for high frequency NILM in huge buildings. We finally show that IVMF outperforms competing methods (Independent Component Analysis, Semi Non-negative Matrix Factorization) on NILM datasets
Maalik, Abdul. "Novel Characteristic-Mode-Based Synthesis and Analysis Method for Reflectarray Antennas." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1593684814222685.
Full textTulpule, Pinak J. "Control and optimization of energy flow in hybrid large scale systems - A microgrid for photovoltaic based PEV charging station." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1313522717.
Full textChadha, Ankit. "Tapped-Inductor Buck DC-DC Converter." Wright State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=wright1578488939749599.
Full textEriksson, Ina, and Lina Fredriksson. "Data-driven methods for estimation of dynamic OD matrices." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-177782.
Full textExamensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet
Foghammar, Nömtak Carl. "Automatic SLAMS detection and magnetospheric classification in MMS data." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-285533.
Full textKorta magnetiska strukturer med hög amplitud (SLAMS) har observeratsav satelliter nära jordens kvasi-parallella bogchock. En kortoch plötslig höjning av magnetfältsstyrkan är ett typiskt drag förSLAMS, vanligtvis med en faktor 2 eller mer. Forskning om SLAMShar tidigare varit begränsad till mindre fallstudier eftersom SLAMSidentifierats genom manuell inspektion av satellitdata. Detta gör detsvårt att dra generella slutsatser och det subjektiva elementet försvårarsamarbetet mellan forskare. En lösning till detta problem presenteras idenna avhandling; en automatisk identifieringsalgoritm för SLAMS. Viundersöker flera metoder och mäter deras prestanda på en uppsättningmanuellt identifierade SLAMS. Den bästa algoritmen används sedan föratt identifiera 98406 SLAMS i data från MMS-uppdraget. Av dessa upptäcktes66210 SLAMS när FPI-instrumentet var aktivt. Vi är dessutomintresserade av att veta om en upptäckt SLAMS finns i förshocken ellermagnetoskiktet. Därför implementerar vi en Gaussisk klassificeraresom bygger på hierarkisk klustring av FPI-data. Den kan separerade fyra distinkta regionerna av magnetosfären som MMS observerar;magnetosfär, magnetoskikt, solvind och (jon) förchock. De identifieradeSLAMS:en sammanställs till en databas som innehåller deras start- ochstoppdatum, positionskoordinater, B-fältsinformation och informationfrån magnetosfärsklassificeraren för att möjliggöra enkel filtrering tillen specifik SLAMS-population. För att visa potentialen av databasenutför vi en preliminär statistisk undersökning av hur egenskapernaav SLAMS påverkas av deras rumsliga och/eller magnetosfäriska position.Databasen och Matlab-implementationen är tillgängliga på Github:https://github.com/cfognom/MMS_SLAMS_detection_and_magnetospheric_classification.
Chen, Wei-Liang, and 陳威良. "Analysis of the Electrically Large Structure by Using FEKO." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/26941210628613039493.
Full textWu, Wei-Yang, and 吳維揚. "The Analysis of Electrically Large Left-Handed Metamaterial Based on Mushroom Structure Using FDTD Approach." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/06595476396464472991.
Full text國立中山大學
電機工程學系研究所
94
A full wave finite-difference time-domain method (FDTD) combined with thin-wire and thin-slot algorithms to analyze a metamaterial fabricated with periodic mushroom structures, is proposed in this dissertation. This proposed method is suitable for analyzing problems involving large structures with fine structural details. A periodic analysis for mushroom structures is presented. Only a single unit mushroom cell is required to present the phenomena of infinite periodicity with the help of periodic boundary conditions (PBCs). The composite right-/left-handed (CRLH) transmission line (TL) approach is introduced and used to approximate CRLH metamaterial through lumped L and C. Finally, several CRLH metamaterial mushroom-based structures are investigated. A 19 by 8 flat microwave lens and a parabolic microwave lens structure composed of 410 unit mushroom cells are investigated. These structures demonstrate negative refractive index (NRI) characteristics while operate in the left-hand (LH) region. The simulation and measurement results of one- and two-dimensional CRLH mushroom-based structures are compared.
"Modeling and Large Signal Stability Analysis of A DC/AC Microgrid." Master's thesis, 2018. http://hdl.handle.net/2286/R.I.50493.
Full textDissertation/Thesis
Masters Thesis Engineering 2018
Zhong, Yu. "Fast algorithms for the design and analysis of large power grids /." 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3314956.
Full textSource: Dissertation Abstracts International, Volume: 69-05, Section: B, page: 3199. Adviser: Martin D. F. Wong. Includes bibliographical references (leaves 89-93) Available on microfilm from Pro Quest Information and Learning.
Cortes-Medellin, German. "Analysis of segmented reflector antenna for a large millimeter wave radio telescope." 1993. https://scholarworks.umass.edu/dissertations/AAI9329588.
Full textTsao, Shu-Wei, and 曹書瑋. "Electrical Analysis & Fabricated Investigation of Amorphous Active Layer Thin Film Transistor for Large Size Display Application." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/56670949870823913179.
Full text國立中山大學
光電工程學系研究所
99
In this dissertation, the electrical characteristics of generally used hydrogenated amorphous silicon (a-Si:H) TFTs in LCD and newly risen amorphous indium-gallium-zinc oxide (a-IGZO) TFTs were studied. For modern mobile display and large-size flat panel display application, the traditional thin-film transistor-liquid crystal display (TFT-LCD) technology confronts with a lot of challenges and problems. In general, flexible displays must exhibit some bending ability; however, bending applies mechanical strain to electronic circuits and affects device characteristics. Therefore, the electrical characteristics of a-Si:H TFTs fabricated on stainless steel foil substrates with uniaxial bending were investigated at different temperatures. Experimental results showed that the on-state current and threshold voltage degraded under outward bending. This is because outward bending will induce the increase of band tail states, affecting the transport mechanism at different temperatures. In addition, for practical operation, the electrical characteristics of a-Si:H TFTs under flat and bending situations after AC/DC stress at different temperatures were studied. It was found that high temperature and mechanical bending played important roles under AC stress. The dependence between the accumulated sum of bias rising and falling time and the threshold voltage shifts under AC stress was also observed. Because a-Si:H is a photosensitive material, the high intensity backlight illumination will degrade the performance of a-Si:H TFTs. Thus, the photo-leakage current of a-Si:H TFTs under illumination was investigated at different temperatures. Experimental results showed that a-Si:H TFTs exhibited a pool performance at lower temperatures. The indirect recombination rate and the parasitic resistance (Rp) are responsible for the different photo-leakage-current trends of a-Si:H TFTs under varied temperature operations. To investigate the photo-leakage current, the a-Si:H TFTs were exposed to ultraviolet (UV) light irradiation. It was found that the photo current of a-Si:H TFTs was reduced after UV light irradiation. The detail mechanisms on reducing/increasing photo-leakage current by UV light irradiation were discussed. Recently, the oxide-based semiconductor TFT, especially a-IGZO TFT, is considered as one of promising candidates for active matrix flat-panel display. However, the a-IGZO TFT exists significant electrical instability issue and manufacturing problems. As a consequence, we investigated the effect of hydrogen incorporation on a-IGZO TFTs to reduce interface states between active layer and insulator. Experimental results showed that the electrical characteristics of hydrogen-incorporated a-IGZO TFTs were improved. The threshold voltage shift (ΔVth) in hysteresis loop is suppressed from 4 V to 2 V due to the hydrogen-induced passivation of the interface trap states. Finally, we reported the effect of ambient environment on a-IGZO TFT instability. As a-IGZO TFTs were stored in atmosphere environment for 40 days, the transfer characteristics accompanying strange hump were observed during bias-stress. The hump phenomenon is attributed to the absorption of H2O molecule. Additionally, the sufficient electric field is also necessary to cause this anomalous transfer characteristic.
"Modal analysis of large-scale power systems' voltage stability and voltage collapse." Tulane University, 1992.
Find full textacase@tulane.edu
Ke, Huajie. "Fabrication, characterization and analysis of patterned nano-sized material with large magnetic permeability at high frequency." 2013. https://scholarworks.umass.edu/dissertations/AAI3603105.
Full textLi, Yujia. "Development and application of the FETI-DPEM algorithm for analysis of three-dimensional large-scale electromagnetic problems /." 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3363018.
Full textSource: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3691. Adviser: Jianming Jin. Includes bibliographical references (leaves 156-162) Available on microfilm from Pro Quest Information and Learning.
(7023038), Thomas E. Craddock. "Ensuring Large-Displacement Stability in ac Microgrids." Thesis, 2019.
Find full textChiang, Chung-Hua, and 江俊華. "Analysis of Schedule Risk Management and Prevention on Large Mechanical and Electrical Engineering Project - Taking Kaohsiung Underground Railway Project as an Example." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/e3w69g.
Full text國立高雄應用科技大學
工業工程與管理系碩士在職專班
104
Project risk management in the implementation of the project life cycle is very important to the progress of construction projects. In the construction process, uncertainties are often encountered. If project risks are not identified, quantified and controlled, these risks are likely to cause project difficulties, and the project will not be completed within contract deadline requirements. As a result, it cannot create the best interests of the project objectives. This study adapted AHP construction questionnaire. Through filling out questionnaires that involve decision-making problems with multiple evaluation criteria by experts in project management fields, assessment factors for priority can be obtained through a systematic approach. By preventing making bad decisions, the purpose of project risk control is achieved. This study uses Electrical and Mechanical Engineering Project of Kaohsiung Railway Underground Program as an example to identify the common seen engineering project risk factors in the aspects of project planning. It is found that subject company uses these 5 items including bad cash flow、unqualified engineer、procurement omission、construction sequence error、imcompliance of as-built and design as main influences factors for planning risk control for an engineering project. By analyzing the important factors and proposing methods to improvement, the purpose of prevention and risk control can be achieved.
Pereira, Mário Pascoal Santos. "Operational Analysis of Distribution Systems Featuring Large-scale Variable RES: Contributions of Energy Storage Systems and Switchable Capacitor Banks." Master's thesis, 2017. https://repositorio-aberto.up.pt/handle/10216/105327.
Full textPereira, Mário Pascoal Santos. "Operational Analysis of Distribution Systems Featuring Large-scale Variable RES: Contributions of Energy Storage Systems and Switchable Capacitor Banks." Dissertação, 2017. https://repositorio-aberto.up.pt/handle/10216/105327.
Full text(7485122), Miaomiao Ma. "Accuracy Explicitly Controlled H2-Matrix Arithmetic in Linear Complexity and Fast Direct Solutions for Large-Scale Electromagnetic Analysis." Thesis, 2019.
Find full textShah, Kalpesh. "Power Grid Analysis In VLSI Designs." Thesis, 2007. http://hdl.handle.net/2005/503.
Full text