SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "hsv:(NATURVETENSKAP) hsv:(Matematik) hsv:(Matematisk analys) "

Sökning: hsv:(NATURVETENSKAP) hsv:(Matematik) hsv:(Matematisk analys)

  • Resultat 2601-2610 av 4632
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
2601.
  • Gyllenberg, Mats, et al. (författare)
  • Non-uniqueness of numerical taxonomic structures
  • 1993
  • Ingår i: Binary Computing in Microbiology. - 0266-304X. ; 5:4, s. 138-144
  • Tidskriftsartikel (refereegranskat)abstract
    • The most important methods of numerical taxonomy in microbiology are based on so called reference matrices giving the frequencies of positive binary features of the different taxa. Microbiologists seem to have been tacitly assuming that every well-defined classification method, that is, every algorithm for constructing a reference matrix from data, leads to a unique classification (reference matrix). We use a mathematical result-that a finite mixture of multivariate Bernoulli distributions is always unidentifiable-to disprove this assumption. We show that the same classification method applied to the same data can always lead to different classifications. This result is of importance for the foundations of computational microbial taxonomy. It is illustrated by simple examples from the two main methods of classification and identification: the one where classification is performed first and then followed by identification, and cumulative classification where classification and identification are carried out simultaneously. The consequences of the non-uniqueness result for microbiological practice are discussed
  •  
2602.
  • Gyllenberg, Mats, et al. (författare)
  • Null recurrence in a stochastic Ricker model
  • 1994
  • Ingår i: Analysis, algebra, and computers in mathematical research. - New York : Marcel Dekker Incorporated. - 0824792173 ; , s. 147-164
  • Konferensbidrag (refereegranskat)abstract
    • We consider a nonlinear first order stochastic difference equation which may be viewed as a stochastic perturbation of {\it W. E. Ricker's} [J. Fish. Res. Bd. Can. 11, 559-623 (1954)] deterministic model of population growth. Numerical experiments seem to suggest that the corresponding Markov process has a stationary probability distribution but this is shown to be false by proving that the process is in fact null recurrent
  •  
2603.
  • Gyllenberg, Mats, et al. (författare)
  • Population models with environmental stochasticity
  • 1994
  • Ingår i: Journal of Mathematical Biology. - 0303-6812 .- 1432-1416. ; 32:2, s. 93-108
  • Tidskriftsartikel (refereegranskat)abstract
    • Two discrete population models, one with stochasticity in the carrying capacity and one with stochasticity in the per capita growth rate, are investigated. Conditions under which the corresponding Markov processes are null recurrent and positively recurrent are derived
  •  
2604.
  • Gyllenberg, Mats, et al. (författare)
  • Quasi-stationary distributions of a stochastic metapopulation model
  • 1994
  • Ingår i: Journal of Mathematical Biology. - 0303-6812 .- 1432-1416. ; 33:1, s. 35-70
  • Tidskriftsartikel (refereegranskat)abstract
    • A stochastic metapopulation model which explicitly considers first order interactions between local populations is constructed. The model takes the spatial arrangement of patches into account and keeps track of which patches are occupied and which are empty. The time-evolution of the meta-population is governed by a Markov chain with finite state space. We give a detailed description of the long term behaviour of the Markov chain. Many interesting biological issues can be addressed using the model. As an especially important example we discuss the so-called core and satellite species hypothesis in the light of the model.
  •  
2605.
  • Gyllenberg, Mats, et al. (författare)
  • Single-species metapopulation dynamics : A structured model
  • 1992
  • Ingår i: Theoretical Population Biology. - 0040-5809 .- 1096-0325. ; 42:1, s. 35-61
  • Tidskriftsartikel (refereegranskat)abstract
    • We describe and analyse a general metapopulation model, which consists of a model of local dynamics within a habitat patch, and balance equations for dispersing individuals and the metapopulation. The model includes the effects of emigration and immigration on local dynamics. We derive the equilibrium population size distribution, which is skewed towards either small or large populations, depending on the relative magnitudes of local and metapopulation time scales. The model predicts a generally positive relationship between the fraction of occupied patches and the average local population size. Such a relationship has been commonly observed in nature. The model allows alternative stable equilibria, not found in models which ignore the effect of dispersal on local dynamics. We discuss the implications of our results for biological invasions and conservation biology
  •  
2606.
  •  
2607.
  •  
2608.
  •  
2609.
  •  
2610.
  • Hagendorf, Christian, et al. (författare)
  • Nearest-Neighbour Correlation Functions for the Supersymmetric XYZ Spin Chain and Painlevé VI
  • 2024
  • Ingår i: Communications in Mathematical Physics. - 0010-3616 .- 1432-0916. ; 405
  • Tidskriftsartikel (refereegranskat)abstract
    • We study nearest-neighbour correlation functions for the ground state of the supersymmetric XYZ spin chain with odd length and periodic boundary conditions. Under a technical assumption related to the Q-operator of the corresponding eight-vertex model, we show that they can be expressed exactly in terms of the Painlevé VI tau functions sn and s¯n introduced by Bazhanov and Mangazeev. Furthermore, we give an interpretation of the correlation functions in terms of the Painlevé VI Hamiltonian.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 2601-2610 av 4632
Typ av publikation
tidskriftsartikel (3207)
konferensbidrag (436)
annan publikation (246)
doktorsavhandling (200)
rapport (150)
bokkapitel (147)
visa fler...
licentiatavhandling (117)
bok (82)
samlingsverk (redaktörskap) (28)
forskningsöversikt (10)
proceedings (redaktörskap) (4)
recension (3)
patent (2)
visa färre...
Typ av innehåll
refereegranskat (3690)
övrigt vetenskapligt/konstnärligt (913)
populärvet., debatt m.m. (29)
Författare/redaktör
Persson, Lars-Erik (393)
Maligranda, Lech (215)
Wall, Peter (117)
Ibragimov, Nail H. (83)
Euler, Norbert (80)
Toft, Joachim, 1964- (56)
visa fler...
Rozenblioum, Grigori ... (53)
Andersson, Mats, 195 ... (51)
Björn, Jana (45)
Kavallaris, Nikos I. (44)
Muntean, Adrian, 197 ... (42)
Sjögren, Peter, 1948 (39)
Maligranda, Lech, 19 ... (39)
Grip, Niklas (39)
Silvestrov, Sergei, ... (38)
Samko, Natasha (38)
Lukkassen, Dag (38)
Björn, Anders (37)
Euler, Marianna (36)
Wennberg, Bernt, 196 ... (34)
Nyström, Kaj, 1969- (34)
Byström, Johan (34)
Strömberg, Thomas (33)
Tephnadze, George (33)
Kruglyak, Natan (32)
Tkachev, Vladimir (31)
Johansson, Maria (30)
Almqvist, Andreas (30)
Fabricius, John (30)
Zhang, Genkai, 1963 (30)
Toft, Joachim (30)
Shahgholian, Henrik (28)
Lärkäng, Richard, 19 ... (28)
Staubach, Wolfgang (28)
Lennerstad, Håkan (27)
Turowska, Lyudmila, ... (27)
Mazya, Vladimir (27)
Lenells, Jonatan, 19 ... (26)
Wulcan, Elizabeth, 1 ... (25)
Samuelsson Kalm, Håk ... (24)
Wedestig, Anna (23)
Kufner, Alois (23)
Andreasson, Håkan, 1 ... (22)
Berman, Robert, 1976 (22)
Wahlberg, Patrik, 19 ... (22)
Roginskaya, Maria, 1 ... (22)
Silvestrov, Sergei, ... (21)
Kovacs, Mihaly, 1977 (21)
Goffeng, Magnus C H ... (21)
Steeb, Willi-Hans (21)
visa färre...
Lärosäte
Luleå tekniska universitet (1277)
Chalmers tekniska högskola (1181)
Göteborgs universitet (824)
Uppsala universitet (398)
Kungliga Tekniska Högskolan (383)
Linköpings universitet (290)
visa fler...
Lunds universitet (279)
Stockholms universitet (187)
Karlstads universitet (180)
Umeå universitet (174)
Blekinge Tekniska Högskola (174)
Linnéuniversitetet (151)
Mälardalens universitet (120)
Örebro universitet (42)
Mittuniversitetet (29)
Malmö universitet (28)
Högskolan i Gävle (24)
Sveriges Lantbruksuniversitet (18)
Högskolan i Halmstad (16)
Högskolan Väst (14)
Högskolan i Borås (13)
Jönköping University (11)
Karolinska Institutet (10)
Handelshögskolan i Stockholm (8)
VTI - Statens väg- och transportforskningsinstitut (5)
RISE (4)
Högskolan i Skövde (3)
Södertörns högskola (1)
Försvarshögskolan (1)
IVL Svenska Miljöinstitutet (1)
visa färre...
Språk
Engelska (4490)
Polska (47)
Svenska (46)
Ryska (33)
Tyska (4)
Franska (4)
visa fler...
Spanska (3)
Kinesiska (2)
Danska (1)
Norska (1)
Estniska (1)
visa färre...
Forskningsämne (UKÄ/SCB)
Naturvetenskap (4632)
Teknik (371)
Samhällsvetenskap (81)
Medicin och hälsovetenskap (24)
Humaniora (18)
Lantbruksvetenskap (4)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy