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Magnus Carlsson

Bio: Magnus Carlsson is an academic researcher from Chalmers University of Technology. The author has contributed to research in topics: Functional programming & Fudgets. The author has an hindex of 16, co-authored 37 publications receiving 808 citations. Previous affiliations of Magnus Carlsson include Saab Automobile AB & Oregon Health & Science University.

Papers
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Proceedings ArticleDOI
01 Jul 1993
TL;DR: This paper describes an implementation of a small windowbased graphical user interface toolkit for X Windows written in the lazy functional language LML, and suggests how the fudgets can evaluate in parallel.
Abstract: This paper describes an implementation of a small windowbased graphical user interface toolkit for X Windows written in the lazy functional language LML. By using this toolkit, a H askell or LML programmer can crest e a user interface with menus, buttons and other graphical interface objects, without conforming to more or less imperative programming paradigms imposed if she were to use a traditional (imperative) toolkit. Instead, the power of the abstraction methods provided by Haskell or LML are used. The main abstraction we use is the fr.dget. Fudgets are combined in a hierarchical structure, and they interact by message passing, The current implementation is baaed on a sequential evaluator, but by using non-determinism and oracles, we suggest how the fudgets can evaluate in parallel. We believe that the toolkit can be extended to a full-feathered and practically useful high level graphical toolkit.

104 citations

Journal ArticleDOI
TL;DR: It is concluded that brown trout show individual variation in habitat preference, which appears to be linked with their investment in territorial defence, which suggests that understanding and modelling of animal contests could benefit from considering how territorial defence is influenced by individual habitat preference and specialisation.
Abstract: The striking ability of territory owners to repel intruders has generated a number of theoretical explanations as well as experimental studies in many animal species. However, effects of individual habitat preferences on territorial defence have rarely been studied. From the territory value hypothesis, we predicted that owners of preferred habitats should invest more resources in defence than owners of non-preferred habitats. We tested this prediction with young territorial brown trout in a two-stage experiment. First, trout were allowed to choose individually between gravel and a uniform bright substrate. As expected, they showed a significant (79%) preference for gravel. However, there was considerable variation between individuals in substrate preference, with a few fish preferring the bright substrate. Half of the tested fish were then transferred to a gravel substrate and the rest to a bright substrate, manipulating habitat type in relation to preference. Territory owners were then staged against size-matched intruders whereupon contest aggression was observed and the winner of each contest determined. Overall, owners won most of the contests. Satisfied owners won 86% and owners of less preferred territories, 74% of the contests. Furthermore, more satisfied owners attacked sooner and were more aggressive relative to the intruders. We conclude that brown trout show individual variation in habitat preference, which appears to be linked with their investment in territorial defence. These results suggest that understanding and modelling of animal contests could benefit from considering how territorial defence is influenced by individual habitat preference and specialisation.

80 citations

Journal ArticleDOI
TL;DR: MDS is quite common among elderly people and there is no evidence for a rising incidence during the last 15 years, as well as similar data on acute myeloid leukaemia.
Abstract: The myelodysplastic syndromes (MDS) have attracted great interest during the last decade. Unfortunately there is not much material published concerning the incidence of these conditions. We present epidemiologic data on MDS based on case registration of patients in a well-defined population and as a comparison similar data on acute myeloid leukaemia (AML). Between the years 1978–1992 we registered 120 cases of MDS and 146 cases of AML. The median age for all the MDS cases was 74.1 years for men and 78.2 years for women. Among haematologists there is a suspicion that the incidence of MDS is rising. Our study does not support this opinion. We have divided the study period into 5-year periods and the crude incidence has been 3.2, 4.1 and 3.5/100 000/year for each period. In the age group over 70 years MDS was more frequent than AML and in the last 5-year period the incidence was 15.0/100 000/year for MDS compared to 10.2/100 000/year for AML. In conclusion MDS is quite common among elderly people and there is no evidence for a rising incidence during the last 15 years.

69 citations

Proceedings ArticleDOI
17 Sep 2002
TL;DR: A monadic variant of that library, written in Haskell extended with first-class references, able to provide a purely functional interface to the library, the types also enforce "correct usage" without having to resort to any type-system extension.
Abstract: This paper presents a monadic approach to incremental computation, suitable for purely functional languages such as Haskell. A program that uses incremental computation is able to perform an incremental amount of computation to accommodate for changes in input data. Recently, Acar, Blelloch and Harper presented a small Standard ML library that supports efficient, high-level incremental computations [1]. Here, we present a monadic variant of that library, written in Haskell extended with first-class references. By using monads, not only are we able to provide a purely functional interface to the library, the types also enforce "correct usage" without having to resort to any type-system extension. We also find optimization opportunities based on standard monadic combinators.This is an exercise in putting to work monad transformers with environments, references, and continuations.

65 citations

Proceedings ArticleDOI
11 Aug 2003
TL;DR: This paper is an initial report on flight experiments with a small, unmanned helicopter using a state dependent Riccati Equation (SDRE) controller for autonomous, agile maneuvering.
Abstract: This paper is an initial report on flight experiments with a small, unmanned helicopter using a state dependent Riccati Equation (SDRE) controller for autonomous, agile maneuvering. The control design is based upon a full, 6-DoF, analytic nonlinear dynamic model, which is manipulated into a pseudo-linear form in which system matrices are given explicitly as a function of the current state. A standard Riccati equation is then solved numerically in each frame of a 50 Hz. control loop to design the state feedback control law on-line. Several flights have been flown with the helicopter to evaluate the accuracy of tracking under SDRE control in comparison with simulation results.

55 citations


Cited by
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01 Jan 2004
TL;DR: This work has consistently shown that there are large performance benefits to be gained by applying Sigma-Point Kalman filters to areas where EKFs have been used as the de facto standard in the past, as well as in new areas where the use of the EKF is impossible.
Abstract: Probabilistic inference is the problem of estimating the hidden variables (states or parameters) of a system in an optimal and consistent fashion as a set of noisy or incomplete observations of the system becomes available online. The optimal solution to this problem is given by the recursive Bayesian estimation algorithm which recursively updates the posterior density of the system state as new observations arrive. This posterior density constitutes the complete solution to the probabilistic inference problem, and allows us to calculate any “optimal” estimate of the state. Unfortunately, for most real-world problems, the optimal Bayesian recursion is intractable and approximate solutions must be used. Within the space of approximate solutions, the extended Kalman filter (EKF) has become one of the most widely used algorithms with applications in state, parameter and dual estimation. Unfortunately, the EKF is based on a sub-optimal implementation of the recursive Bayesian estimation framework applied to Gaussian random variables. This can seriously affect the accuracy or even lead to divergence of any inference system that is based on the EKF or that uses the EKF as a component part. Recently a number of related novel, more accurate and theoretically better motivated algorithmic alternatives to the EKF have surfaced in the literature, with specific application to state estimation for automatic control. We have extended these algorithms, all based on derivativeless deterministic sampling based approximations of the relevant Gaussian statistics, to a family of algorithms called Sigma-Point Kalman Filters (SPKF). Furthermore, we successfully expanded the use of this group of algorithms (SPKFs) within the general field of probabilistic inference and machine learning, both as stand-alone filters and as subcomponents of more powerful sequential Monte Carlo methods (particle filters). We have consistently shown that there are large performance benefits to be gained by applying Sigma-Point Kalman filters to areas where EKFs have been used as the de facto standard in the past, as well as in new areas where the use of the EKF is impossible.

1,116 citations

Journal ArticleDOI
01 Jul 2008-Blood
TL;DR: MDS incidence rates significantly increased with calendar year in 2001 through 2004, and only 4% of patients were reported to registries by physicians' offices, suggesting that MDS disease burden in the United States may be underestimated.

586 citations

Journal ArticleDOI
24 Oct 2013-Blood
TL;DR: Within the myelodysplastic syndrome (MDS) work package of the European LeukemiaNet, an Expert Panel was selected according to the framework elements of the National Institutes of Health Consensus Development Program and Guidelines were developed on the basis of a list of patient- and therapy-oriented questions.

537 citations

Journal ArticleDOI
01 May 2000
TL;DR: The paper shows how many of the techniques of monadic programming generalise to the new setting, and gives examples to show that the greater generality is useful, and proposes a generalisation of monads, which I call arrows, with significantly wider applicability.
Abstract: Monads have become very popular for structuring functional programs since Wadler introduced their use in 1990. In particular, libraries of combinators are often based on a monadic type. Such libraries share (in part) a common interface, from which numerous benefits flow, such as the possibility to write generic code which works together with any library. But, several interesting and useful libraries are fundamentally incompatible with the monadic interface. In this paper I propose a generalisation of monads, which I call arrows, with significantly wider applicability. The paper shows how many of the techniques of monadic programming generalise to the new setting, and gives examples to show that the greater generality is useful. In particular, three non-monadic libraries for efficient parsing, building graphical user interfaces, and programming active web pages fit naturally into the new framework.

501 citations

01 Dec 2004
TL;DR: In this article, a probabilistic framework called Sigma-Point Kalman Filters (SPKF) was applied to the problem domain addressed by the extended Kalman Filter (EKF).
Abstract: A probabilistic framework, called Sigma-point Kalman Filters (SPKF) was applied to the problem domain addressed by the extended Kalman Filter (EKF). SPKF methods are superior to the standard EKF based estimation approaches, as an SPKF achieves second-order or higher accuracy. The SPKF has also been applied to the integrated navigation problem as it relates to unmanned aerial vehicle (UAV) autonomy. The SPKF-based sensor latency compensation technique is used to demonstrate the lagged GPS measurements.

353 citations