Avancerad sökning

Visar resultat 1 - 5 av 804 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Distance Protection of Transmission Lines with High Levels of Series Compensation : A study on frequency and time domain communication independent distance protection for series compensated lines

   Författare :Md Tanbhir Hoq; Nathaniel Taylor; Jianping Wang; Claus Leth Bak; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Series capacitor; Series compensation; Transmission line; Distance protection; Incremental quantity; Lissajous curve; RL model; RLC model; Seriekondensator; Seriekompensation; Transmissionslinje; Distansskydd; Inkrementell kvantitet; Lissajous-kurva; RL-modell; RLC-modell; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Series capacitors are used in electric transmission lines to increase their power transfer capacity. They compensate for the inductive reactance of the line. They offer a useful alternative to building new lines, in view of economic and environmental constraints. LÄS MER

3. 2. Data driven modeling in the presence of time series structure: : Improved bounds and effective algorithms

   Författare :Othmane Mazhar; Boualem Djehiche; Munther Dahleh; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Time series; Non-asymptotic estimation; Minimax; Change point detection; Hidden Markov model; State space model; Least square; Penalized Regression; Random covariance matrix; Concentration inequality; Chaining integral; Self-normalized martingale inequality; Cramér-Rao inequality; van Trees inequality; Matematisk statistik; Mathematical Statistics;

   Sammanfattning : This thesis consists of five appended papers devoted to modeling tasks where the desired models are learned from data sets with an underlying time series structure. We develop a statistical methodology for providing efficient estimators and analyzing their non-asymptotic behavior. LÄS MER

4. 3. Essays on Time Series Analysis : With Applications to Financial Econometrics

   Författare :Daniel Preve; Rolf Larsson; Bent Nielsen; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; non-Gaussian time series; nonnegative autoregression; robust estimation; strong convergence; realized volatility; volatility forecast; forecast comparison; Diebold-Mariano test; Statistics; Statistik;

   Sammanfattning : This doctoral thesis is comprised of four papers that all relate to the subject of Time Series Analysis.The first paper of the thesis considers point estimation in a nonnegative, hence non-Gaussian, AR(1) model. The parameter estimation is carried out using a type of extreme value estimators (EVEs). LÄS MER

5. 4. Long-Term Simulation of Coastal Evolution

   Författare :Hoan Le Xuan; Avdelningen för Teknisk vattenresurslära; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; tidal inlet; inlet shoal; sediment transport; spit growth; shoreline change; spit model; inlet model; mathematical model; numerical model; shoreline model;

   Sammanfattning : There is a strong relationship between regional sediment transport and the local processes at tidal inlets and around coastal structures. Many coastal projects require quantitative understanding of these processes and the interactions between them. LÄS MER

7. 5. Model Reduction for Linear Time-Varying Systems

   Författare :Henrik Sandberg; Anders Rantzer; Sanjay Lall; Institutionen för reglerteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Automation; robotics; control engineering; Performance limitations; Convergence analysis; Frequency-domain analysis; Error bounds; Time-varying systems; Model reduction; Linear systems; Automatiska system; robotteknik; reglerteknik; Model reduction;

   Sammanfattning : The thesis treats model reduction for linear time-varying systems. Time-varying models appear in many fields, including power systems, chemical engineering, aeronautics, and computational science. They can also be used for approximation of time-invariant nonlinear models. Model reduction is a topic that deals with simplification of complex models. LÄS MER