Sökning: "high-rate theory"

Visar resultat 1 - 5 av 24 avhandlingar innehållade orden high-rate theory.

1. 1. Simulation of dynamic instabilities during high rate deformation of ductile bars and plates

   Författare :Kristina Nilsson; Mekanik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; numerical simulation; non-linear; wave propagation; multiple necking; necking; buckling; fracture; Mechanical engineering; Maskinteknik; finite elements; cohesive elements; dynamic; J2-flow theory; J2-deformation theory; viscoplastic; background inertia;

   Sammanfattning : In this thesis, some of the phenomena occurring in plates and cylindrical bars subjected to dynamic loading are investigated. Numerical simulations using a dynamic finite element code are performed for a number of different sized specimens with various initial surface imperfections. Typically imposed loading velocities are in the range 10m/s.. LÄS MER

3. 2. Source and Channel Coding for Audiovisual Communication Systems

   Författare :Moo Young Kim; Bastiaan Kleijn; Richard Heusdens; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Telekommunikation; Information theory; high-rate theory; source coding; channel coding; quantization; Telekommunikation; Telecommunication; Telekommunikation;

   Sammanfattning : Topics in source and channel coding for audiovisual communication systems are studied. The goal of source coding is to represent a source with the lowest possible rate to achieve a particular distortion, or with the lowest possible distortion at a given rate. Channel coding adds redundancy to quantized source information to recover channel errors. LÄS MER

4. 3. Constitutive equations for concrete materials subjected to high rate of loading

   Författare :Mattias Unosson; Larsgunnar Nilsson; Lars Olovsson; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Continuum mechanics; Numerical analysis; Drop weight testing; Electrical engineering; Elektroteknik;

   Sammanfattning : Continuum mechanics is used to model the mechanical behaviour of concrete structures subjected to high rates of loading in defence applications. Large deformation theory is used and an isotropic elastic-plastic constitutive equation with isotropic hardening, damage and strain rate dependent loading surface. LÄS MER

5. 4. Towards Asymptotic Vector Quantization

   Författare :Jonas Samuelsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; EM algorithm; parametric models; expectation maximization; spectrum coding; Gaussian mixture models; fast search; bounded support; multidimensional companding; vector quantization; high rate quantization;

   Sammanfattning : We study topics in source coding, and vector quantization (VQ) in particular. We approach VQ from two directions: a theoretical starting point based on high rate quantization theory, and a practical based on a database desription of the signal source. LÄS MER

7. 5. Redox Reactions of NO and O2 in Iron Enzymes : A Density Functional Theory Study

   Författare :Mattias Blomberg; Per Siegbahn; Adrian Mulholland; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; enzyme catalysis; redox reactions; cytochrome oxidase; nitric oxide reductase; hyponitrous acid anhydride; peroxynitrite; myoglobin; prostaglandin synthase; PGHS; NO; N2O; O2; CO; Chemical physics; Kemisk fysik;

   Sammanfattning : In the present thesis the density functional B3LYP has been used to study reactions of NO and O2 in redox active enzymes.Reduction of nitric oxide (NO) to nitrous oxide (N2O) is an important part in the bacterial energy conservation (denitrification). LÄS MER