Sökning: "Christer Bäckström"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Christer Bäckström.

  1. 1. Reasoning about interdependent actions

    Författare :Christer Bäckström; Linköpings universitet; []
    Nyckelord :HUMANIORA; HUMANITIES;

    Sammanfattning : This thesis consists of two papers on different but related topics.The first paper is concerned with the use of logic as a tool to model mechanical assembly processes. LÄS MER

  3. 2. Computational Complexity of some Optimization Problems in Planning

    Författare :Meysam Aghighi; Peter Jonsson; Christer Bäckström; Hector Geffner; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Automated planning is known to be computationally hard in the general case. Propositional planning is PSPACE-complete and first-order planning is undecidable. One method for analyzing the computational complexity of planning is to study restricted subsets of planning instances, with the aim of differentiating instances with varying complexity. LÄS MER

  4. 3. Acute intermittent porphyria, women and sex hormones. Screening for hepatocellular carcinoma in porphyria

    Författare :Eva Innala; Christer Andersson; Marie Bixo; Torbjörn Bäckström; Raili Kauppinen; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Obstetrics and gynaecology; Obstetrik och gynekologi; obstetrik och gynekologi; Obstetrics and Gynaecology;

    Sammanfattning : Background:   Porphyrias are inherited disorders with impaired heme biosynthesis. Acute intermittent porphyria (AIP) is the most common porphyria in Sweden. AIP attacks may be life-threatening. Female sex hormones are regarded as important precipitating factors. LÄS MER

  5. 4. Strong Partial Clones and the Complexity of Constraint Satisfaction Problems : Limitations and Applications

    Författare :Victor Lagerkvist; Peter Jonsson; Christer Bäckström; Nadia Creignou; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : In this thesis we study the worst-case time complexity of the constraint satisfaction problem parameterized by a constraint language (CSP(S)), which is the problem of determining whether a conjunctive formula over S has a model. To study the complexity of CSP(S) we borrow methods from universal algebra. LÄS MER

  7. 5. Methods for Detecting Unsolvable Planning Instances using Variable Projection

    Författare :Simon Ståhlberg; Peter Jonsson; Christer Bäckström; Malte Helmert; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : In this thesis we study automated planning, a branch of artificialintelligence, which deals with construction of plans. A plan is typically an action sequence that achieves some specific goal. In particular, we study unsolvable planning instances, i.e. LÄS MER