Sökning: "Waveform"

Visar resultat 1 - 5 av 132 avhandlingar innehållade ordet Waveform.

1. 1. Quantifying the Seismic Response of Underground Structures via Seismic Full Waveform Inversion : Experiences from Case Studies and Synthetic Benchmarks

   Författare :Fengjiao Zhang; Christopher Juhlin; Ari Tryggvason; Yanghua Wang; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; full waveform inversion; waveform tomography; CO2 monitoring; CO2 sequestration; time lapse seismic; Inversion; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

   Sammanfattning : Seismic full waveform inversion (waveform tomography) is a method to reconstruct the underground velocity field in high resolution using seismic data. The method was first introduced during the 1980’s and became computationally feasible during the late 1990’s when the method was implemented in the frequency domain. LÄS MER

3. 2. Fiber-based all-optical sampling for ultrafast waveform monitoring

   Författare :Mathias Westlund; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polarization independent; waveform monitoring; software synchronization; four-wave mixing; all-optical sampling;

   Sammanfattning : Digital sampling is a technique to visualize a time-varying waveform by capturing quasi-instantaneous snapshots of a signal via a sampling gate. The gate is opened and closed by narrow pulses in a pulse train having a well defined repetitive behaviour such that all parts of the waveform are measured. LÄS MER

4. 3. Waveform and Receiver Filter Selection for Wideband Radar Applications

   Författare :Marie Ström; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; interference suppression.; detection; waveform design; receiver filter design; Wideband radar; performance evaluation;

   Sammanfattning : This thesis concerns the design of transmitter-receiver chains for widebandradar systems. The transmitter side employs one, or several, highly flexiblesignal generators, which are able to generate signals with a large bandwidth. LÄS MER

5. 4. Robust Transceiver Design and Waveform Synthesis for Wideband MIMO Radar

   Författare :Marie Ström; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wideband radar; Robust analysis; Interference; Waveform synthesis; Transmit–receive filter design; MIMO radar;

   Sammanfattning : This thesis deals with the problem of designing and synthesizing waveforms that are optimal, both in a signal-to-noise-and-interference ratio (SNIR), and in a system hardware design perspective, i.e., to synthesize time domain waveforms with a low peak-to-average power ratio (PAPR), or even constant modulus. LÄS MER

7. 5. Electrothermal Simulation in a Concurrent Waveform Relaxation Based Circuit Simulator

   Författare :Magnus Wiklund; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Circuit synthesis; Bond graphs; Nullor; Circuit theory; Analog simulation; Circuit simulation; Multiprocessor computer; CONCISE; Parallel computation; Waveform relaxation; Thermal models; Transistor models; Electro-thermal simulation; Electro-thermal modeling; Translinear circuits; Electronics; Elektronik; Electrical engineering; Elektroteknik;

   Sammanfattning : The main purpose of this work is to study methods to simulate electro-thermal effects in integrated circuits using CONCISE a waveform relaxation based circuit simulator. WR is a method that is suitable to run on a multi-computer with state of the art computing power. Especially CMOS VLSI circuits have been simulated successfully with WR. LÄS MER