| 1. |
- Angelsmark, Ola, 1972-, et al.
(författare)
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Determining the Number of Solutions to Binary CSP Instances
- 2002
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Ingår i: Principles and Practice of Constraint Programming, 8th International Conference CP-2002,2002. - Heidelberg : Springer Verlag. ; , s. 327-
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Konferensbidrag (refereegranskat)abstract
- Counting the number of solutions to CSP instances has applications in several areas, ranging from statistical physics to artificial intelligence. We give an algorithm for counting the number of solutions to binary CSPs, which works by transforming the problem into a number of 2-SAT instances, where the total number of solutions to these instances is the same as those of the original problem. The algorithm consists of two main cases, depending on whether the domain size d is even, in which case the algorithm runs in O(1.3247^n*(d/2)^n) time, or odd, in which case it runs in O(1.3247^n*((d^2+d+2)/4)^(n/2)) if d=4*k+1, and O(1.3247^n*((d^2+d)/4)^(n/2)) if d=4*k+3. We also give an algorithm for counting the number of possible 3-colourings of a given graph, which runs in O(1.8171^n), an improvement over our general algorithm gained by using problem specific knowledge.
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| 2. |
- Angelsmark, Ola, 1972-, et al.
(författare)
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Finite Domain Constraint Satisfaction Using Quantum Computation
- 2002
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Ingår i: Mathematical Foundations of Computer Science, 27th International Symposium MFCS-2002,2002. - Heidelberg : Springer Verlag. ; , s. 93-
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Konferensbidrag (refereegranskat)abstract
- We present a quantum algorithm for finite domain constraint solving, where the constraints have arity 2. It is complete and runs in time, where d is size of the domain of the variables and n the number of variables. For the case of d=3 we provide a method to obtain an upper time bound of . Also for d=5 the upper bound has been improved. Using this method in a slightly different way we can decide 3-colourability in O(1.2185^n) time.
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| 3. |
- Angelsmark, Ola, et al.
(författare)
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Improved algorithms for counting solutions in constraint satisfaction problems
- 2003
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Ingår i: Principles and Practice of Constraint Programming, 9th International Conference CP 2003,2003. - Berlin, Heidelberg : Springer. ; , s. 81-95
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Konferensbidrag (refereegranskat)abstract
- Counting the number of solutions to CSP instances has vast applications in several areas ranging from statistical physics to artificial intelligence. We provide a new algorithm for counting the number of solutions to binary CSP s which has a time complexity ranging from O ((d/4 . alpha(4))(n)) to O((alpha + alpha(5) + [d/4 - 1] . alpha(4))(n)) (where alpha approximate to 1.2561) depending on the domain size d greater than or equal to 3. This is substantially faster than previous algorithms, especially for small d. We also provide an algorithm for counting k-colourings in graphs and its running time ranges from O ([log(2) k](n)) to O ([log(2) k + 1](n)) depending on k greater than or equal to 4. Previously, only an O(1.8171(n)) time algorithm for counting 3-colourings were known, and we improve this upper bound to O(1.7879(n)).
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| 4. |
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| 5. |
- Hallencreutz, Daniel
(författare)
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Populärmusik, kluster och industriell konkurrenskraft : En ekonomisk-geografisk studie av svensk musikindustri
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The economic importance of design-intensive and cultural-products industries has grown in recent decades. One case in point is Sweden, where internationally competitive industries have emerged in areas such as multimedia, fashion, and music. During the 1990s, research in economic geography and related disciplines concerned with the link between geographical location and competitive advantage has found an important source of inspiration in the cluster approach. The thesis examines the relationship between spatial clustering and industrial competitive-ness by undertaking a series of empirical studies that explore various dimensions of the Swedish music industry. The thesis demonstrates that the Swedish music industry embraces a multitude of actors in a complex, spatially clustered production system characterised by dense social networks, which transcend individual firms. Processes and mechanisms that have enhanced the creation and diffusion of strategic knowledge as well as co-operative competition further promote the competitiveness of this cluster. Moreover, the thesis demonstrates that it is necessary to carefully consider the relation between the local milieu and the global music industrial production and distribution system in order to fully understand competitiveness in the music industry. Finally, the thesis examines how the cluster concept has been put into practice in Swedish industrial and regional policies concerning cultural industries.
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| 6. |
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| 7. |
- Jonsson, Ola, et al.
(författare)
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ICT and the Geography of Innovative Firms
- 2003
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Ingår i: Intelligent Management in the Knowledge Economy. - 184376 4717 ; , s. 244-256
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 8. |
- Jonsson, Ola
(författare)
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Innovation processes and proximity: The case of IDEON firms in Lund, Sweden
- 2002
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Ingår i: European Planning Studies. - : Informa UK Limited. - 1469-5944 .- 0965-4313. ; 10:6, s. 705-722
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Tidskriftsartikel (refereegranskat)abstract
- Increasing pressure on innovativeness and collaboration is supposed to strengthen the importance of geographical proximity in innovation systems. But simultaneously there are;globalization forces' and information and communication technology (ICT) developments that stress wider contexts and different dependencies to place and distance. With case studies of innovative firms at IDEON Science Park in Lund, the article presents analyses of the importance of proximity, related to the kind of knowledge and collaborative arrangements involved in innovation processes. Scope for 'untraded interdependencies' is discussed as well as the possible ICT impact of these collaborative relations. Argument for a three tier innovation system is put forward and its implications for regional innovation strategies are, concludingly, discussed.
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| 9. |
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| 10. |
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