Search for dissertations about: "computational complexity"

Showing result 6 - 10 of 525 swedish dissertations containing the words computational complexity.

2. 6. Optimization of Joint Cell, Channel and Power Allocation in Wireless Communication Networks

   Author : Mikael Fallgren; Anders Forsgren; Zhi-Quan (Tom) Luo; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wireless multicell networks; Optimization; OFDMA; Shannon capacity; Complexity; NP-hard; Relays; Allocation problems; Heuristic algorithms;

   Abstract : In this thesis we formulate joint cell, channel and power allocation problems within wireless communication networks. The objectives are to maximize the user with mini- mum data throughput (Shannon capacity) or to maximize the total system throughput, referred to as the max-min and max-sum problem respectively. READ MORE

4. 7. Constructing Evolutionary Trees - Algorithms and Complexity

   Author : Anna Östlin; Institutionen för datavetenskap; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Computer science; Maximum homeomorphic subtrees; Consensus trees; Experiment model; Evolutionary trees; Complexity; Computational biology; Algorithms; Data structures; numerical analysis; systems; control; Datalogi; numerisk analys; system; kontroll; Biology; Biologi;

   Abstract : In this thesis three general problems concerning construction of evolutionary trees are considered. Algorithms for the problems are presented and the complexity of the problems is investigated. The thesis consists of three corresponding parts. The first part is devoted to the problem of constructing evolutionary trees in the experiment model. READ MORE

5. 8. Polyhedral and complexity studies in integer optimization, with applications to maintenance planning and location–routing problems

   Author : Adam Wojciechowski; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; integer linear programming; complexity theory; polyhedral analysis; stochastic programming; maintenance optimization; Hamiltonian p-median problem; maintenance optimization;

   Abstract : This thesis develops integer linear programming models for and studies the complexity of problems in the areas of maintenance optimization and location–routing. We study how well the polyhedra defined by the linear programming relaxation of themodels approximate the convex hull of the integer feasible solutions. READ MORE

6. 9. Managers' Cooperative Work Practices in Computational Artefacts-Supported Library Systems

   Author : Niki Chatzipanagiotou; Anita Mirijamdotter; Jaime Campos; Christina Mörtberg; Ulrika Lund Snis; Linnéuniversitetet; []
   Keywords : SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Work Practice; Cooperative Work; Cooperative Work Practices; Computational Artefacts; Computer-Supported Cooperative Work; Articulation Work; Awareness; Appropriation; Ethnography; Focused-Ethnography; Fieldwork; Vignettes; Complexity; Managers; Management; Libraries; Academic Library; Academic Library Managers; Informatik; Information Systems;

   Abstract : The dissertation presents understandings of the complex, contextual, cooperative everyday work practices of academic library managers supported by computational artefacts, as well as challenges disrupting their practices and thereby computational artefacts usage. The doctoral research approaches and conceptualises managers’ work as ‘everyday cooperative practice’, in this way adopting the computer-supported cooperative work (CSCW) approach. READ MORE

7. 10. Algorithms and Complexity for Temporal and Spatial Formalisms

   Author : Thomas Drakengren; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : The problem of computing with temporal information was early recognised within the area of artificial intelligence, most notably the temporal interval algebra by Allen has become a widely used formalism for representing and computing with qualitative knowledge about relations between temporal intervals. However, the computational properties of the algebra and related-formalisms are known to be bad: most problems (like satisfiability) are NP-hard. READ MORE