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  • 1. Fundinger, Danny
    et al.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Osipenko, George
    On the appearance of multiple attractors in discrete food-chains2007In: Applied Mathematics and Computation, ISSN 0096-3003, E-ISSN 1873-5649, Vol. 184, p. 429-444Article in journal (Refereed)
  • 2. Gyllenberg, Mats
    et al.
    Hanski, Ilkka
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    A predator-prey model with optimal suppression of reproduction in the prey1996In: Mathematical Biosciences, Vol. 139, p. 119-152Article in journal (Refereed)
  • 3.
    Gyllenberg, Mats
    et al.
    University of Helsinki, Finland.
    Hanski, Ilkka
    University of Helsinki, Finland.
    Lindström, Torsten
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Conditional reproductive strategies under variable environmental conditions2017In: Annales Zoologici Fennici, ISSN 0003-455X, E-ISSN 1797-2450, Vol. 54, no 1-4, p. 193-204Article in journal (Refereed)
    Abstract [en]

    Within the framework of adaptive dynamics we consider the evolution by natural selection of reproductive strategies in which individualsmay adjust their reproductive behaviour in response to changing environmental conditions. As a specific example we consider a discrete-time model in which possible fluctuations in the environmental conditions are caused by predator-prey interaction. Our main findings include: 1) Coexistence between two fixed strategies (i.e., strategies that do not adjust to changing environmental conditions) is impossible. There exists a best fixed strategy, which invades and ousts all other fixed strategies. 2) A necessary condition for conditional (adjustable) strategies to evolve is that there are fluctuations in the environmental conditions. Predator-prey interactions may cause such fluctuations and under natural assumptions there exists an optimal conditional strategy which is uninvadable and invades and ousts allother strategies.

  • 4. Gyllenberg, Mats
    et al.
    Hanski, Ilkka
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Continuous versus discrete single species models with adjustable reproductive strategies1997In: Bulletin of mathematical biology, Vol. 59, no 4, p. 679-705Article in journal (Refereed)
  • 5.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    A generalized uniqueness theorem for limit cycles in a predator-prey system1989In: Acta Academiae Aboensis, Vol. 49, no 2, p. 1-9Article in journal (Other academic)
  • 6.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Dependencies between Competition and Predation - and their Consequenses for Initial Value Sensitivity1999In: SIAM Journal of Applied Mathematics, Vol. 59(4):1468-1486, no 4, p. 1468-1486Article in journal (Refereed)
  • 7.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Detecting chaos requires careful analysis of nearly periodic data2009In: Chaos, Solitons & Fractals, ISSN 0960-0779, E-ISSN 1873-2887, Vol. 42, no 1, p. 212-223Article in journal (Refereed)
    Abstract [en]

    We show that models fitted to data in many cases fit unstable periodic solutions in attracting periodic solutions of the 'true model' that generated the data. An attracting solution containing the neighborhood of the fitted unstable solution in its domain of attraction may possess entirely different dynamical properties. Thus, an attracting chaotic solution with positive Lyapunov exponent may describe periodic solutions with negative Lyapunov exponents and vice versa. These problems can in principle be remedied, if the fitted models would be allowed to contain an arbitrary complexity and if an infinite amount of data would be available. We claim that we stay far from such limits in ecology, for instance. Therefore, we think our approach is essential to bear in mind when making data-based predictions concerning dynamical behavior. Our general conclusion is that less data is required in nearly periodic cases than in chaotic cases for rejecting models not allowing complex behavior.

  • 8.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Detecting chaos requires careful analysis of periodic data (extended abstract)2008In: University of Kalmar 6th International Conference on Technologies from Waste and Wastewater Treatment, Energy from Waste, Remediation of Contaminated Sites, and Emissions Related to Climate / [ed] Fabio Kaczala, Jeanger Juanga, William Hogland, Marcia Marques, and Eva Vinrot, Kalmar, Sweden, 2008Conference paper (Other academic)
  • 9.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Discrete models and Fisher's maximum principle in ecology2003In: Discrete and continuous dynamical systems Expanded volume for the Wilmington Meeting, May 24-27, 2003 / [ed] Wei Feng, Shouchuan Hu, and Xin Lu, Springfield, USA, 2003Conference paper (Refereed)
  • 10.
    Lindström, Torsten
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Dynamical properties of maps fitted to data in the noise-free limit2013In: Journal of Biological Dynamics, ISSN 1751-3758, E-ISSN 1751-3766, Vol. 7, no S1, p. 108-116Article in journal (Refereed)
    Abstract [en]

    We argue that any attempt to classify dynamical properties from nonlinear finite time-series data requires a mechanistic model fitting the data better than piecewise linear models according to standard model selection criteria. Such a procedure seems necessary but still not sufficient.

  • 11.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Fitting TAR(1) models to Sheperd data2007In: Proc. Appl. Math. Mech. 7, 2007Conference paper (Refereed)
  • 12.
    Lindström, Torsten
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Friskolor - ett hot mot glesbygden2010Other (Other (popular science, discussion, etc.))
    Abstract [sv]

    "Det kostar olika mycket att driva skolor i olika områden." Torsten Lindström, docent i matematik på Linnéuniversitetet i Kalmar har synpunkter på den svenska friskolesystemet.

  • 13.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Global stability of a model for competing predators1994In: Marcel Dekker, Inc analysis, algebra, and computers in mathematical research, proceedings of the twenty-first Nordic Congress of mathematicians / [ed] Mats Gyllenberg and Lars-Erik Persson, New York, Basel, Hong Kong, 1994Conference paper (Refereed)
  • 14.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Global Stability of a model for competing predators: An extension of the Ardito & Ricciardi Lyapunov function2000In: Nonlinear Analysis, Vol. 39, p. 793-805Article in journal (Refereed)
  • 15.
    Lindström, Torsten
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Investeringar blir till konsumption2012Other (Other (popular science, discussion, etc.))
    Abstract [sv]

    Att lära sig räkna övningsexempel i matematikmed digitala hjälpmedel saknar bildningsvärde och gör kunskapen teknikberoende. Kunskapen föråldras på det här viset fort.

  • 16.
    Lindström, Torsten
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Limit cycles in planar systems of ordinary differential equations2021In: Handbook of the Mathematics in the Arts and the Sciences / [ed] Bharath Srinaman, Switzerland: Springer, 2021, 1Chapter in book (Refereed)
    Abstract [en]

    The idea of a dynamical system is predicting the future of a given system with respect to some initial conditions. If the dynamical system is formulated as a differential equation, then there is usually a direct relation between the dynamical system and the processes involved. Today, we can easily say that dynamical systems can predict a huge number of phenomena, including chaos. The real question is therefore, not whether complicated phenomena may occur, but whether restrictions on the possible dynamics exist.

    In this chapter, we commence with major theorems that are frequently used for justifying phase space analysis. We continue with simple examples that either possess limit cycles and classes of differential equations that never possess limit cycles. We end up with the ideas behind two major theorems that put bounds for the number of limit cycles from above: Sansone's (1949) theorem and Zhang's (1986) theorem. Both theorems apply to systems that have a clear mechanistic interpretation. We outline the major arguments behind the quite precise estimates used in these theorems and describe their differences. Our objective is not to formulate these theorems in their most general form, but we give references to recent extensions.

  • 17.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Lärarutbildningens utmaningar i längre perspektiv2008In: Barometern OT, no 20080502Article in journal (Other (popular science, discussion, etc.))
  • 18.
    Lindström, Torsten
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Mathematics and Recurrent Population Outbreaks2019In: Handbook of the Mathematics of the Arts and Sciences / [ed] Bharath Sriraman, Cham: Springer, 2019Chapter in book (Refereed)
    Abstract [en]

    Despite that outbreaks had been observed for hundreds of years for many populations, it took until the 1920s before the first mechanisms that did not involve human interference were suggested. Just a few mechanisms were included in the first models and the question whether the inclusion of other, very plausible, mechanisms could alter the predictions remained. In this chapter, we follow the development of models that have been proposed to explain oscillatory population dynamics from the early models suggested by Lotka (1925) and Volterra (1926) until global dynamical questions that are still open for models incorporating explicit resource dynamics, like the chemostat, cf Kuang (1989).

  • 19.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Med focus på linjär algebra2005 (ed. 1)Book (Other academic)
  • 20.
    Lindström, Torsten
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Med fokus på linjär algebra2017 (ed. 3)Book (Other academic)
    Abstract [sv]

    Den linjära algebran innehåller i dag ett rikt spektrum av metoder som används och en förståelse för dessa metoder krävs inom nästanalla samhällsområden som använder datorer, beräkningar,bildbehandling eller liknande. Även om verkligheten ofta är ickelinjär, så kräver icke-linjär analys ofta mycket god förståelse av de linjära specialfallen. Få delområden i matematiken kan på en lika elementär nivå klargöra skillnaderna mellan effektiva och mindre effektiva algoritmer och åskådliggöra vilken potential matematiken ger för en fortsatt samhällsutveckling.

    Denna bok riktar sig till den grupp av studenter, som behöverkomma in på egenvärden och egenvektorer redan efter enförhållandevis kort kurs i linjär algebra. Vid urvalet av stoff har det tagits hänsyn till att vissa studenter kommer att välja att läsa mer linjär algebra efter denna kurs, medan andra inte kommer att göra det.

    Denna upplaga har kompletterats med nya avsnitt om bland annat minsta kvadratmetoden och ett stort antal övningar. Gamla tentamensuppgifter förekommer bland dessa. Videoinspelningar av undervisning som ansluter sig till delar av bokens texter och övningar existerar.

  • 21.
    Lindström, Torsten
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Med Fokus på Linjär Algebra2014 (ed. 2)Book (Other academic)
    Abstract [sv]

    Den linjära algebran innehåller i dag ett rikt spektrum av metoder som används och en förståelse för dessa metoder krävs inom nästan alla samhällsområden som använder datorer, beräkningar, bildbehandling eller liknande. Även om verkligheten ofta är icke-linjär, så kräver icke-linjär analys ofta mycket god förståelse av de linjära specialfallen. Få delområden i matematiken kan på en lika elementär nivå klargöra skillnaderna mellan effektiva och mindre effektiva algoritmer och åskådliggöra vilken potential mate­ma­tiken ger för en fortsatt samhällsutveckling.Denna bok riktar sig till den grupp av studenter, som behöver komma in på egenvärden och egenvektorer redan efter en för­hållandevis kort kurs i linjär algebra. Vid urvalet av stoff har det tagits hänsyn till att vissa studenter kommer att välja att läsa mer linjär algebra efter denna kurs, medan andra inte kommer att göra det.Denna upplaga har kompletterats bland annat med ett stort antal övningar. Gamla tentamensuppgifter förekommer bland dessa. Videoinspelningar av undervisning som ansluter sig till delar av bokens texter och övningar existerar.

  • 22.
    Lindström, Torsten
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Monotone dynamics or not?: Dynamical consequences of various mechanisms for delayed logistic growth2017In: Differential Equations & Applications, ISSN 1847-120X, Vol. 9, no 3, p. 379-382Article in journal (Refereed)
    Abstract [en]

    In this paper we interpret the global stability properties of the delayed single species chemostat in terms of monotone dynamics on an asymptotically invariant hyperplane in the state space. The consequence is a translation of advanced analysis and delay differential equations into sign checks and ordinary differential equations for an important single species model with explicit resource dynamics. Complete proofs are included, since the limiting behavior at asymptotically invariant sets may not agree with the limiting behavior of the original system even in the finite dimensional case (Thieme (1992)). A delayed logistic equation based on explicit resource dynamics falls out as a limiting case of the chemostat and we claim this to be a new mechanistic interpretation of delayed logistic models. We continue by comparing these results to several other delayed logistic models that has been mechanistically justified in the literature. We conclude that monotone dynamics apply in several cases. We improve one global stability result that cannot be obtained with by the use of monotone dynamics and end up by pointing out the dynamical differences between Hutchinson’s (1948) delayed logistic equation and those with mechanistic interpretations.

  • 23.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    On oral examination techniques when engineering mathematics2006In: CED Utvecklingskonferensen för högre utbildning, Proceedings 2005 / [ed] Ingrid Järnefelt, Lund, Sweden, 2006Conference paper (Refereed)
  • 24.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    On oral examination techniques when teaching engineering mathematics2003In: Nordic Pre-conference to ICME10 at Växjö University, Sweden, May 9-11, 2003, Växjö, Sweden, 2003Conference paper (Refereed)
  • 25.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    On the dynamics of discrete food-chains: Low- and high-frequency behavior and optimality of chaos2002In: Journal of Mathematical Biology, Springer, Vol. 45, p. 396-418Article in journal (Refereed)
  • 26.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Oral assessment techniques for mathematics teaching that include elements of learning2007In: Växjö University, Växjö, Sweden, 2007Conference paper (Other academic)
  • 27.
    Lindström, Torsten
    Luleå University of Technology.
    Predator-Prey systems and Applications1991Licentiate thesis, monograph (Other academic)
  • 28.
    Lindström, Torsten
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Problems in relating various tasks and their samplesolutions to Bloom’s taxonomy2017In: The Montana Mathematics Enthusiast, ISSN 1551-3440, E-ISSN 1551-3440, Vol. 14, no 1-3, p. 15-28Article in journal (Refereed)
    Abstract [en]

    In this paper we analyze sample solutions of a number of problems and relate them to their level as prescribed by Bloom’s taxonomy. We relate these solutions to a number of other frameworks, too. Our key message is that it remains insufficient to analyze written forms of these tasks. We emphasize careful observations of how different students approach a solution before finally assessing the level of tasks used. We take the arithmetic series as our starting point and point out that the objective of the discussion of the examples here in no way is to indicate an optimal way towards a solution. Instead, our intent is to demonstrate the potential of well selected tasks and the variation that could be observed as students develop their solutions. A large part of this work is devoted to an analysis of the richness of the square triangular number problem.

  • 29.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Qualitative analysis of a predator-prey system with limit cycles1993In: Journal of Mathematical Biology, Vol. 31, p. 541-561Article in journal (Refereed)
  • 30.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Recent progress in discrete population dynamics2009In: Nonlinear Analysis 71, 2009Conference paper (Refereed)
  • 31.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Relations between statistically and mechanistically derived models1999Report (Other academic)
  • 32.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Risktagande med stora belopp2008In: Barometern-OT, no 20081022Article in journal (Other (popular science, discussion, etc.))
  • 33.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Skolor för bättre folks sämre barn?2006In: Barometern OT, Vol. 20060901Article in journal (Other (popular science, discussion, etc.))
  • 34.
    Lindström, Torsten
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Skrivstilen som försvann2013Other (Other (popular science, discussion, etc.))
    Abstract [sv]

    Förmågan att ta anteckningar vid högre studier är något som måste tränas under skoltiden. Man måste lära sig skrivstil. Det ger ett aktivt förhållningssätt till studierna, till skillnad från att bara passivt lyssna på inspelade föreläsningar, skriver professor Torsten Lindström

  • 35.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Stability switches in discrete food-chain problems2009In: International Journal of Bifurcation and Chaos in Applied Sciences and Engineering, ISSN 0218-1274, Vol. 19, no 9, p. 3067-3085Article in journal (Refereed)
    Abstract [en]

    In an already classical paper, May [ 1976] pointed out that simple nonlinear models in ecology can possess complicated dynamics. A long debate concerning the possible existence of chaotic ecologies has followed the appearance of this paper. Morris [ 1990] stressed that several problems exist when making conclusions regarding chaotic or nonchaotic dynamics as models are fitted to ecological data. Takens' theorem [ 1981] should, in principle, provide tools for solving some of these problems, but in reality essential assertions are most often violated. First, limits regarding the length of the used time-series must be assumed. Second, the theorem can be applied for evaluating positive Lyapunov exponents only, and is hence not applicable for distinguishing nonchaotic dynamics from chaotic. We use a deterministic food-chain model that possesses a wide range of different dynamical patterns to demonstrate the existence of cases that are misclassified with respect to chaotic or nonchaotic motion as models are fitted to data in the various dynamical regimes. Our results are valid regardless of what finite data size is assumed. The results are best understood for high-periodic cases in the noise-free limit. If the relevant phase-space is not sufficiently well-populated with data in the vicinity of the periodic orbit, then sufficient complexity of the models are not supported by standard model selection criteria like AIC or GCV. Thus, the fitted models only in the best cases contain information concerning both the location of the periodic orbit and the eigenvalues of the Jacobians evaluated along the periodic orbit. If the space is moderately well populated with data, then the data is often described by an unstable periodic orbit of the fitted model. The attractor that was to be described by the fitted model was destabilized and is now a repeller. We call this phenomenon stability switches. It reminds about the noise-induced phenomenon reported by Rand and Wilson [ 1992], but we point out that the problem reported here is caused by the fitting procedure itself, not by the added noise. The repeller that has been created by the model-fitting procedure can be located in the basins of attraction of some fixed point, the infinity, or some periodic or chaotic attractors of the fitted models. The situation seems similar when periodic attractors are not well enough populated with data for describing their location and when chaotic attractors are to be described by data. Similar stability switches occur and the dynamics of models fitted to data may differ or coincide with the dynamics of the attractor that generated the data in an unpredictable manner.

  • 36.
    Lindström, Torsten
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Torsås framtid en valfråga2012In: Barometern OT, ISSN 1103-906XArticle in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    Få barnfamiljer väljer att flytta till orter där inte skola finns för mer än något år framåt. Om man stryper inflyttningen så finns snart inga skolor alls kvar där. Och vilken annan verksamhet kommer då att finns kvar?

  • 37.
    Lindström, Torsten
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Torsås, Lärarjobben och Avundsjukan2010Other (Other (popular science, discussion, etc.))
    Abstract [sv]

    Skolområdet borde undantas från blockpolitik. Det är långsiktiga överenskommelser kombinerat med gedigna utbildningskrav för lärare som ger resultat. Det skriver Torsten Lindström, lektor på Linnéuniversitetet i Kalmar, och åberopar både finska framgångar på skolområdet och läget i Torsås kommun.

  • 38.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Tänk om alla har fel om klimatet2008In: Barometern OT, no 20080514Article in journal (Other (popular science, discussion, etc.))
  • 39.
    Lindström, Torsten
    Luleå University of Technology.
    Why Do Rodent Populations Fluctuate? Stability and Bifurcation Analysis of Some Discrete and Continuous Predator-Prey Models1995Doctoral thesis, monograph (Other academic)
  • 40.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Är profilering den rätta nya skolreligionen?2008In: Barometern-OT, no 20080714Article in journal (Other (popular science, discussion, etc.))
  • 41.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Är profilering en ny religion?2008In: Barometern OT, no 20080610Article in journal (Other (popular science, discussion, etc.))
  • 42.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Övningar och MatLab-laborationer till Med fokus på Linjär Algebra2006Other (Other (popular science, discussion, etc.))
  • 43.
    Lindström, Torsten
    et al.
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Cheng, Yuanji
    Malmö University.
    A Rosenzweig-MacArthur (1963) Criterion for the Chemostat2016In: Scientific World Journal, ISSN 1537-744X, E-ISSN 1537-744X, article id 5626980Article in journal (Refereed)
    Abstract [en]

    The Rosenzweig-MacArthur (1963) criterion is a graphical criterion that has been widely used for elucidating the local stability properties of the Gause (1934) type predator-prey systems. It has not been stated whether a similar criterion holds for models with explicit resource dynamics (Kooi et al. (1998)), like the chemostat model. In this paper we use the implicit function theorem and implicit derivatives for proving that a similar graphical criterion holds under chemostat conditions, too. 

  • 44.
    Lindström, Torsten
    et al.
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Cheng, Yuanji
    Malmö University.
    Uniqueness of limit cycles for a limiting case of the chemostat: does it justify the use of logistic growth rates?2015In: Electronic journal on the qualitative theory of differential equations, ISSN 1417-3875, E-ISSN 1417-3875, no 47, p. 1-14Article in journal (Refereed)
    Abstract [en]

    On infinitesimally short time intervals various processes contributing to population change tend to operate independently so that we can simply add their contributions (Metz and Diekmann, The dynamics of physiologically structured populations, 1986, p. 3). This is one of the cornerstones for differential equations modeling in general. Complicated models for processes interacting in a complex manner may be built up, and not only in population dynamics. The principle holds as long as the various contributions are taken into account exactly. In this paper we discuss commonly used approximations that may lead to non-removable dependency terms potentially affecting the long run qualitative behavior of the involved equations. We prove that these terms do not produce such effects in the simplest and most interesting biological case, but the general case is left open. Our main result is a rather complete analysis of an important limiting case. Once complete knowledge of the qualitative properties of simple models is obtained, it greatly facilitates further studies of more complex models. A consequence of our analysis is that standard methods can be applied. However, the application of those methods is far from straightforward and require non-trivial estimates in order to make them valid for all values of the parameters. We focus on making these proofs as elementary as possible.

  • 45.
    Lindström, Torsten
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Lindberg, A Michael
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Nammari, Diauddin R
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Stolte, Willem
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Nonlinear Deterministic modelling of ecological communuities - typical predictions and limitations2004In: Proceedings of ECO-TECH' 03, RFVs UTVECKLINGSSATSNING DEPONERING 2 / [ed] William Hogland and Nadja Kuznetsova, Kalmar, Sweden, 2004Conference paper (Other academic)
  • 46.
    Lindström, Torsten
    et al.
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Nilsson, Marcus
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Låt eleverna ta eget ansvar2015In: Smålandsposten, , p. 1article id 27 janArticle in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    Hittills har man från politiskt håll kommit med få förslag som berör annat än rent organisatoriska åtgärder för skolan (mindre klasser, när betyg ska ges, läxor eller inte). Enligt vår mening är det viktigare att diskutera hur betygen sätts och hur läxorna ges skriver Marcus Nilsson, prefekt för Institutionen för matematik och Torsten Lindström, professor i matematik.

  • 47.
    Lindström, Torsten
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Söderbacka, Gunnar
    Högskolan i Finnmark.
    On the stability-complexity relation for unsaturated semelpareous discrete food-chains2011In: Studies in mathematical sciences, ISSN 1923-8444, E-ISSN 1923-8452, Vol. 2, no 1, p. 157-182Article in journal (Refereed)
    Abstract [en]

    In this paper we formally prove that invading carnivores in thediscrete food-chain derived and preliminary analyzed inLindström (2002) always makes thesystem less stable and thus, limit the food-chain length in thecorresponding system. Hence, invading unsaturated carnivores arenot able to stabilize oscillatory dynamics.

    What we prove constitutes a significant difference betweendiscrete and continuous food-chains. Actually, Freedman andWaltman (1977) related the stabilizingproperties of an invading carnivore in continuous food-chains to absence of saturation: An unsaturated carnivore keeps at least oneinterior equilibrium - if one exists - locally stable.

    One consequence is that the dynamics of unsaturated discretefood-chains display similarities with saturated continuousfood-chains. Indeed, discrete dynamics seem to have a similardestabilizing impact on the dynamics as saturation has.

  • 48.
    Lindström, Torsten
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Thunberg, Hans
    An elementary approach to dynamics and bifurcations of skew tent maps2008In: Journal of difference equations and applications (Print), ISSN 1023-6198, E-ISSN 1563-5120, Vol. 14, no 8, p. 819-833Article in journal (Refereed)
  • 49.
    Melin, Jan
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Hultgren, Anders
    University of Kalmar, Department of Technology.
    Lindström, Torsten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Two types of Limit Cycles of a Resonant Converter modelled by a three-dimensional system2008In: Nonlinear Analysis: Hybrid Systems, ISSN 1751-570X, Vol. 2, no 4, p. 1275-1286Article in journal (Refereed)
  • 50.
    Nilsson, Per
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Lindström, Torsten
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Connecting Swedish compolsory schoolteachers' content knowledge of probability to their level of education, teaching years and self-assessments of probability concepts2012Conference paper (Refereed)
    Abstract [en]

    This paper reports on a survey on teachers’ content knowledge of probability and with connecting such knowledge to the teachers’ level of education, teaching years and self-assessments of probability concepts. Twenty-nine teachers in compulsory school answered a questionnaire calling for reflection on these issues. The teachers’ responses disclose that the teachers find probability to be a difficult subject. The survey reports that the teachers have low confidence in understanding key concepts of probability and that they have difficulties in applying the concepts in probability tasks. The test indicates no correlation between teaching years and confidence or between teaching years and results on the probability tasks. 

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