With a University education in information science and electronic media technology from Ilmenau Technical University Alexander's PhD work focused on efficient, robust and quality-optimal multimedia networking protocols. In Ilmenau he was also teaching operating and distributed systems courses as well as IT security. His current research areas are advanced (3D) video processing architectures, real-time interactive media communication systems and audiovisual quality assessment methodology with a particular interest in electronic media arts, interaction design and information visualisation.

Based on the investigation and understanding of human perceptual limits and cognitive processes Alexander creates software tools which make information technology suitable for humans in particular purposes. He is also very much concerned about security and privacy risks imposed on our society by badly designed and carelessly deployed networked IT systems and ubiquitous surveillance machines.

Alexander is researcher and project manager in the Media Performance Group at Simula Research Laboratory, Norway.

Research Interests

• Advanced Video Processing
  multi-dimensional video scalability; 3D camera and display technologies, light-field coding

• Audiovisual Quality Assessment
  subjective and objective quality of experience assessment methods for scalable video coding and 3D video
  

• Multimedia Protocols and Systems
  efficient, robust and quality-optimal delivery of encoded multimedia streams over packet networks; importance estimation, selective error control and unequal error protection
  
• Scalable and High-performance System Architectures
  zero-copy buffer management, system design for multicore processor architectures, event-based concurrency, lock-free data structures; API abstractions and software architectures for middleware, I/O systems, and networking protocols to improve performance of high-throughput, low-delay and realtime applications
• Cross-Layer Coordination in System Architectures
  System-level design principles that enable generic coordination of mechanisms and strategies across multiple system layers; exploit application-level hints in content-aware transport layers to improve network efficiency and error resilience
• Security and Privacy in System Architectures
  API abstractions and software architectures for operating systems and middleware that foster the integration of security models and privacy into system architectures

Projects

• Art.on.Wires - A Laboratory for Live and Interactive Art & Technology, Initiator and Organiser
  
• Verdione - 3D video and realtime streaming for mixed reality performances, related to the World Opera
  
• PERCEVAL - Perceptual and Cognitive Quality Evaluation Techniques for Audiovisual Systems
  
• H.264/SVC Quality Assessment - a subjective field study to assess the QoE performance of SVC's multi-dimensional scalability
• Stream Router - an in-kernel video stream delivery service that combines zero-copy data passing with media-aware stream processing for Linux
• Noja Middleware - an extensible middleware platform written in C++ that provides a convenient programming model to build network-adaptive streaming applications and reuse content-aware transport protocols; the novelty of this platform is that programmers can choose the level of transparency at design-time, that is which protocol details and communication errors are visible to the application
• Noja Simulation Tools - a set of tools and C++ libraries for building and running audio/video streaming simulations on top of network simulators and real networks, including tools to encode streams, analyze bitstream structure, and assess video quality
• Dependency Model - a generic service to efficiently track and reason about dependencies in packetized media streams

Current Community Services

• IEEE International Symposium on Multimedia -TPC (ISM 2010, 13. - 15. Dec 2010, Taichung, Taiwan)
• IEEE SPS Multimedia Signal Processing Conference- TPC (MMSP 2010, October 4-6 2010, Saint-Malo, France)
  

• International Workshop on SECurity and SOCial Networking - TPC (SESOC 2011,  23. Mar 2011, Seattle, USA)

Past Community Services

• Verdikt Conference Programm Committee (3.-4. Nov 2009, Oslo, Norway, Verdikt is the IT program of the Norwegian Research Council)
  
• ACM Multimedia - TPC (19. Oct - 24. Oct 2009, Beijing, China)
• IEEE International Symposium on Multimedia -TPC (ISM 2009, 14. - 16. Dec 2009, San Diego, USA)
• International Workshop on SECurity and SOCial Networking - TPC (SESOC 2010,  29. Mar - 2. Apr 2010, Mannheim, Germany)

• Tenth International Symposium on Multimedia (ISM 2008, 15. - 17. Dec 2008, Berkeley, USA)
• International Workshop on War & Peace Driving (with the WiMob Conference 2008, 12. Oct 2008, Avignon, France)
• ACM Multimedia - Technical Demonstrations TPC (27. Oct - 1. Nov 2008, Ottawa, Canada)
• Workshop on Security in Opportunistic and Social Networks (SOSOC 2008, with SecureComm 2008, 22. Sep 2008, Istanbul, Turkey)