Sökning: "A Cheng"

Visar resultat 1 - 5 av 61 avhandlingar innehållade orden A Cheng.

1. 1. Factors modifying cellular response to ionizing radiation

   Författare :Lei Cheng; Andrzej Wojcik; Siamak Haghdoost; Lovisa Lundholm; Penelope A. Jeggo; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Radiation biology; DNA damage; gene expression; alpha particles; X-rays; mixed beams; gamma rays; hypothermia; dose rate.; molekylär biovetenskap; Molecular Bioscience;

   Sammanfattning : Many physical factors influence the biological effect of exposure to ionizing radiation, including radiation quality, dose rate and temperature. This thesis focuses on how these factors influence the outcome of exposure and the mechanisms behind the cellular response. LÄS MER

3. 2. Online trajectory planning and observer based control

   Författare :David A. Anisi; Xiaoming Hu; Daizhan Cheng; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Computational Optimal Control; Receding Horizon Control; Mission Uncertainty; Safety; Task Completion; Consensus Problem; Simultaneous Arrival; Adaptive Grid Methods; Missile Guidance; Nonlinear Observer Design; Active Observers; Non--uniformly Observable Systems; Mobile Robotic Systems; Intrinsic Observers; Differential Geometric Methods; Euler-Lagrange Systems; Contraction Analysis.; Optimization; systems theory; Optimeringslära; systemteori;

   Sammanfattning : The main body of this thesis consists of four appended papers. The first two consider different aspects of the trajectory planning problem, while the last two deal with observer design for mobile robotic and Euler-Lagrange systems respectively. LÄS MER

4. 3. A Segmented Silicon Strip Detector for Photon-Counting Spectral Computed Tomography

   Författare :Cheng Xu; Hans Bornefalk; Mats Danielsson; Ami Altman; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; photon counting; spectral computed tomography; silicon strip detector; ASIC; energy resolution; cadmium telluride; charge sharing; Monte Carlo simulation; synchrotron;

   Sammanfattning : Spectral computed tomography with energy-resolving detectors has a potential to improve the detectability of images and correspondingly reduce the radiation dose to patients by extracting and properly using the energy information in the broad x-ray spectrum. A silicon photon-counting detector has been developed for spectral CT and it has successfully solved the problem of high photon flux in clinical CT applications by adopting the segmented detector structure and operating the detector in edge-on geometry. LÄS MER

5. 4. Community involvement & ecomuseums : towards a mutual approach to ecomuseology and landscape studies

   Författare :Cheng Chang; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

   Sammanfattning : Ecomuseums are museums for, by, and about people at home in their own environment (Keyes, 1992). Since their establishment in 1971, community involvement has been a defining characteristic of ecomuseums. Such community involvement does not just preserve artefacts, but also protects and creates its own physical environment in the form of landscape. LÄS MER

7. 5. Ultrafast Photoionization Dynamics Studied with Coincidence Momentum Imaging Spectrometers

   Författare :Yu-Chen Cheng; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Photoionization; High-order Harmonic Generation; Extreme Ultraviolet; Free-Electron Laser; Molecular Dissociation; Charge Transfer; Coincidence Measurement; Momentum Imaging; Electron Wave Packet; Fysicumarkivet A:2019:Cheng;

   Sammanfattning : The time scale of the dynamics in atoms and molecules varies from attoseconds (10-18) to picoseconds (10-12) depending on the size of the particles. To study such dynamics, ultrafast light pulses are needed to trigger and capture the reaction. One of the most direct methods consists in ionizing the system and observing the following response. LÄS MER