Sökning: "Block 2007"

Visar resultat 6 - 10 av 51 avhandlingar innehållade orden Block 2007.

1. 6. Cross-layer Aspects in OFMDA Systems : Feedback, Scheduling and Beamforming

   Författare :Patrick Svedman; Björn Ottersten; Ana I. Pérez-Neira; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Telecommunication; Telekommunikation;

   Sammanfattning : This thesis mainly studies the downlink of a wireless multiuser system, where the transmitter has limited knowledge about the communication channels of the users. Key techniques to improve the performance of such systems are, for instance, multiple antennas, multiuser diversity and orthogonal frequency-division multiple access (OFDMA). LÄS MER

3. 7. Ionic Transport in Metal Oxides Studied in situ by Impedance Spectroscopy and Cyclic Voltammetry

   Författare :Johan Öijerholm; Jinshan Pan; Jürgen Fleig; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ionic transport; alumina; zirconia; in situ impedance spectroscopy; molecular dynamics; high temperature cyclic voltammetry; spark plasma sintering; initial oxidation; FeCrAl alloy; grain size; space charge model.; Electrochemistry; Elektrokemi;

   Sammanfattning : Ionic transport in metal oxides is crucial for the functioning of a broad range of different components, such as heat resistant alloys designed for high temperature applications and oxide electrolytes in solid oxide fuel cells. This thesis presents results from in situ electrochemical studies of properties related to ionic transport in metal oxides that are important for their applications as protective oxides and ionic conductors. LÄS MER

4. 8. Ro52 antibodies and susceptibility genes in congenital heart block

   Författare :Linn S Strandberg; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :;

   Sammanfattning : Congenital heart block (CHB) develops in fetuses of Ro/SSA and La/SSB positive women. During pregnancy, the autoantibodies cross the placenta and affect the fetus in which a potentially lethal atrioventricular (AV) block may develop. LÄS MER

5. 9. Robust Preconditioners Based on the Finite Element Framework

   Författare :Erik Bängtsson; Maya Neytcheva; Per Lötstedt; Svetozar Margenov; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; FEM; iterative solution method; algebraic multilevel preconditioner; sparse approximate inverse; block preconditioner; Schur complement approximation; nonsymmetric saddle point matrix; isostatic glacial adjustment; pre-stress advection; elasticity; viscoelasticity; in compressible solid; ABAQUS; BEM DDM; Scientific Computing; Beräkningsvetenskap;

   Sammanfattning : Robust preconditioners on block-triangular and block-factorized form for three types of linear systems of two-by-two block form are studied in this thesis. The first type of linear systems, which are dense, arise from a boundary element type of discretization of crack propagation problems. LÄS MER

7. 10. Algorithms for a Partially Regularized Least Squares Problem

   Författare :Ingegerd Skoglund; Tommy Elfving; Inge Söderkvist; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Least squares; Regularization; Block-matrices; Conjugate gradient; QR-factorization; Cross-validation; Numerical analysis; Numerisk analys;

   Sammanfattning : Vid analys av vattenprover tagna från t.ex. ett vattendrag betäms halten av olika ämnen. Dessa halter är ofta beroende av vattenföringen. LÄS MER