Search for dissertations about: "Lennart Johnsson"

Found 4 swedish dissertations containing the words Lennart Johnsson.

  2. 1. On-demand Restricted Delegation : A Framework for Dynamic, Context-Aware, Least-Privilege Delegation in Grids

    Author : Mehran Ahsant; Lennart Johnsson; Marty Humphrey; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Grid Security; Restricted and Context-Aware Delegation; Delegation Protocol; On-demand Delegation; Dynamic Trust Federation; Grid Interoperability; Credential Mapping; Computer science; Datalogi;

    Abstract : In grids, delegation is a key facility that can be used to authenticate and authorize requests on behalf of disconnected users. In current grid systems,delegation is either performed dynamically, in an unrestricted manner, or by a secure but static method. READ MORE

  4. 2. Unobtrusive Augmentation  of Physical Environments : Interaction Techniques, Spatial Displays and Ubiquitous Sensing

    Author : Alex Olwal; Steven Feiner; Lennart Johnsson; Yngve Sundblad; Mark Billinghurst; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Computer science; Datalogi;

    Abstract : The fundamental idea of Augmented Reality (AR) is to improve and enhance our perception of the surroundings, through the use of sensing, computing and display systems that make it possible to augment the physical environment with virtual computer graphics. AR is, however, often associated with user-worn equipment, whose current complexity and lack of comfort limit its applicability in many scenarios. READ MORE

  5. 3. Modeling, Control and Protection of Low-Voltage DC Microgrids

    Author : Daniel Salomonsson; Lennart Söder; Brian K. Johnsson; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; circuit transient analysis; dc power systems; dispersed storage and generation; load modeling; power conversion; power distribution control; power distribution faults; power distribution protection; power electronics; Electric power engineering; Elkraftteknik;

    Abstract : Current trends in electric power consumption indicate an increasing use of dc in end-user equipment, such as computers and other electronic appliances used in households and offices. With a dc power system, ac/dc conversion within these loads can be avoided, and losses reduced. READ MORE

  6. 4. Managing Service Levels in Grid Computing Systems : Quota Policy and Computational Market Approaches

    Author : Thomas Sandholm; Lennart Johnsson; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Grid Market; Computational Grid; Service Level Management; QoS; HPC; Grid Middleware; Computer science; Datavetenskap;

    Abstract : We study techniques to enforce and provision differentiated service levels in Computational Grid systems. The Grid offers simplified provisioning of peak-capacity for applications with computational requirements beyond local machines and clusters, by sharing resources across organizational boundaries. READ MORE