Sökning: "Ge Zhang"

Visar resultat 1 - 5 av 18 avhandlingar innehållade orden Ge Zhang.

1. 1. Towards Secure SIP Signalling Service for VoIP applications : Performance-related Attacks and Preventions

   Författare :Ge Zhang; Simone Fischer-Hübner; Costas Lambrinoudakis; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; SIP; VoIP; Security; Computer science; Datavetenskap; Datavetenskap; Computer Science;

   Sammanfattning : Current Voice over IP (VoIP) services are regarded less secure than the traditional public switched telephone network (PSTN). This is due to the fact that VoIP services are frequently deployed in an relatively open environment so that VoIP infrastructures can be easily accessed by potential attackers. LÄS MER

3. 2. Unwanted Traffic and Information Disclosure in VoIP Networks : Threats and Countermeasures

   Författare :Ge Zhang; Simone Fischer-Huebner; Costas Lambrinoudakis; Karlstads universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SIP; VoIP; security; Denial of Service; Vulnerability analysis; timing attacks; Spam; DTMF; SIP; RTP; Computer Science; Datavetenskap;

   Sammanfattning : The success of the Internet has brought significant changes to the telecommunication industry. One of the remarkable outcomes of this evolution is Voice over IP (VoIP), which enables realtime voice communications over packet switched networks for a lower cost than traditional public switched telephone networks (PSTN). LÄS MER

4. 3. Electronic and atomic structure of metal induced reconstructionson Si(lll) and Ge(lll) surfaces studied by PES and STM

   Författare :Hanmin M. Zhang; Hanno H. Weitering; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Deposition of metal atoms on semiconductors leads in many cases to reconstructed surfaces. The lack of symmetry in the direction normal to the surface allows for a large variety in the atomic arrangements of the surface reconstructions. In the case of silicon, more than 300 kinds of adsorbate-induced surface reconstructions have been found. LÄS MER

5. 4. Thin Mn silicide and germanide layers studied by photoemission and STM

   Författare :Joakim Hirvonen Grytzelius; Lars Johansson; Hanmin Zhang; Leif Johansson; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Semiconductor surfaces; Si 111 ; Ge 111 ; manganese; Mn; silicides; germanides; atomic structure; electronic structure; magnetic properties; LEED; ARPES; XPS; core-level spectroscopy; STM; STS; XMCD; Physics; Fysik;

   Sammanfattning : The research presented in this thesis concerns experimental studies of thin manganese silicide and germanide layers, grown by solid phase epitaxy on the Si(111)7×7 and the Ge(111)c(2×8) surfaces, respectively. The atomic and electronic structures, as well as growth modes of the epitaxial Mn-Si and Mn-Ge layers, were investigated by low-energy electron diffraction (LEED), angle-resolved photoelectron spectroscopy (ARPES), core-level spectroscopy (CLS), and scanning tunneling microscopy and spectroscopy (STM and STS). LÄS MER

7. 5. Contributions to Variable Fidelity MDO Framework for Collaborative and Integrated Aircraft Design

   Författare :Zhang Mengmeng; Arthur Rizzi; Leifsson Leifur; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aerospace Engineering; Flyg- och rymdteknik;

   Sammanfattning : The thesis develops computational tools for early stages of the aircraft design process. The work focuses on a framework which allows several design teams concurrently to develop a baseline concept into a configuration which meets requirements and whose aerodynamics has been assessed by flight simulation. LÄS MER