| 1. |
- Andersson, Martin, 1974, et al.
(författare)
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Use of Self-Assembled Surfactants for Nanomaterials Synthesis
- 2009
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Ingår i: Particulate Systems in Nano- and Biotechnologies. ; , s. 27-51
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Synthesis of inorganic materials with nanosized dimensions can take advantage of the ability of surfactants to self-assemble into well-defined structures. These structures are used as a kind of template for the synthesis. This approach of nanomaterials preparation has triggered substantial interest both in the surface chemistry and the materials chemistry community. The accuracy and reproducibility of the self-assembly process has been seen as means of achieving control of materials architecture on the nanometer scale. This is a biomimetic approach; a wide variety of biological structural materials are made by a templating process with the use of surface active compounds—primarily surface active polymers but also low molecular weight polar lipids. The number of papers dealing with surfactant-templated synthesis of inorganic materials has increased dramatically in recent years and several review papers deal with various aspects of the technique (1-12). Existing and potential applications for the synthesized materials range from biomaterials (e.g., artificial bone), to technical products such as catalysts, magnetic particles, and pigments.
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| 2. |
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| 3. |
- Andreasson, Henrik, 1977-, et al.
(författare)
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A Minimalistic Approach to Appearance-Based Visual SLAM
- 2008
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Ingår i: IEEE Transactions on Robotics. - New York, NY, USA : IEEE. - 1552-3098. ; 24:5, s. 991-1001
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a vision-based approach to SLAM in indoor / outdoor environments with minimalistic sensing and computational requirements. The approach is based on a graph representation of robot poses, using a relaxation algorithm to obtain a globally consistent map. Each link corresponds to a relative measurement of the spatial relation between the two nodes it connects. The links describe the likelihood distribution of the relative pose as a Gaussian distribution. To estimate the covariance matrix for links obtained from an omni-directional vision sensor, a novel method is introduced based on the relative similarity of neighbouring images. This new method does not require determining distances to image features using multiple view geometry, for example. Combined indoor and outdoor experiments demonstrate that the approach can handle qualitatively different environments (without modification of the parameters), that it can cope with violations of the “flat floor assumption” to some degree, and that it scales well with increasing size of the environment, producing topologically correct and geometrically accurate maps at low computational cost. Further experiments demonstrate that the approach is also suitable for combining multiple overlapping maps, e.g. for solving the multi-robot SLAM problem with unknown initial poses.
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| 4. |
- Andreasson, Henrik, 1977-, et al.
(författare)
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Drive the Drive : From Discrete Motion Plans to Smooth Drivable Trajectories
- 2014
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Ingår i: Robotics. - Basel, Switzerland : M D P I AG. - 2218-6581. ; 3:4, s. 400-416
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Tidskriftsartikel (refereegranskat)abstract
- Autonomous navigation in real-world industrial environments is a challenging task in many respects. One of the key open challenges is fast planning and execution of trajectories to reach arbitrary target positions and orientations with high accuracy and precision, while taking into account non-holonomic vehicle constraints. In recent years, lattice-based motion planners have been successfully used to generate kinematically and kinodynamically feasible motions for non-holonomic vehicles. However, the discretized nature of these algorithms induces discontinuities in both state and control space of the obtained trajectories, resulting in a mismatch between the achieved and the target end pose of the vehicle. As endpose accuracy is critical for the successful loading and unloading of cargo in typical industrial applications, automatically planned paths have not been widely adopted in commercial AGV systems. The main contribution of this paper is a path smoothing approach, which builds on the output of a lattice-based motion planner to generate smooth drivable trajectories for non-holonomic industrial vehicles. The proposed approach is evaluated in several industrially relevant scenarios and found to be both fast (less than 2 s per vehicle trajectory) and accurate (end-point pose errors below 0.01 m in translation and 0.005 radians in orientation).
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| 5. |
- Andreasson, Henrik, 1977-, et al.
(författare)
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Non-iterative Vision-based Interpolation of 3D Laser Scans
- 2007
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Ingår i: Autonomos Agents and Robots. - Berlin/Heidelberg, Germany : Springer. - 9783540734239 ; , s. 83-90
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- 3D range sensors, particularly 3D laser range scanners, enjoy a rising popularity and are used nowadays for many different applications. The resolution 3D range sensors provide in the image plane is typically much lower than the resolution of a modern colour camera. In this chapter we focus on methods to derive a highresolution depth image from a low-resolution 3D range sensor and a colour image. The main idea is to use colour similarity as an indication of depth similarity, based on the observation that depth discontinuities in the scene often correspond to colour or brightness changes in the camera image. We present five interpolation methods and compare them with an independently proposed method based on Markov random fields. The proposed algorithms are non-iterative and include a parameter-free vision-based interpolation method. In contrast to previous work, we present ground truth evaluation with real world data and analyse both indoor and outdoor data.
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| 6. |
- Birgisson, Björn, et al.
(författare)
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Determination and Prediction of Crack Patterns in Asphalt Mixture under Static Loading
- 2006
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Ingår i: International Conference on CRACK PATHS (CP 2006).
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Konferensbidrag (refereegranskat)abstract
- This paper presents a comparison between predicted and measured crack patterns developing in asphalt mixtures during static loading. Two different state configuration were investigated performing the Indirect Tensile Test (IDT) and the Semi-Circular Bending Test (SCB). A Digital Image Correlation System was applied to obtain a dense and accurate displacement/strain field of asphalt mixtures and for describing the cracking behavior. The resulting fracture behavior in the tests was predicted using a displacement discontinuity boundary element method to explicitly model the microstructure of asphalt mixtures. The predicted crack initiation and crack propagation patterns are consistent with observed cracking behavior. The results also imply that fracture in mixtures can be modeled effectively using a micromechanical approach that allows for crack growth both along aggregate surfaces, as well as through aggregates.
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| 7. |
- Bjernhager, Lisa, 1956-, et al.
(författare)
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Medierande verktyg som stöttning av studenters skrivande i högre utbildning
- 2022
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Ingår i: Journal of Teaching and Learning in Higher Education (JoTL). - : Malmö universitet. - 2004-4097. ; 3:1
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Utifrån ett sociokulturellt perspektiv på lärande och teorier om medierande verktyg och utvecklingszoner (Säljö, 2000, 2005; Vygotsky, 1978), är syftet med artikeln att bidra med kunskap inom forskningsfältet ämnesintegrerat skrivande. Utgångspunkten är att studenters skrivande är socialt situerat (Lillis, 2001) och att undervisning om akademisk litteracitet måste ske i de sammanhang där ämneskunskapen kommuniceras (Wingate, 2015). Pedagogiska aktiviteter som diskuteras utgår huvudsakligen från projektet Hållbar pedagogisk grund för studenters läs- och skrivfärdigheter. Denna aktionsbaserade forskning, som genomfördes i kollaborativt samarbete mellan kritiska vänner och ämneslärare, resulterade i förändrade medierande verktyg i form av tre olika stöttningsformer, strukturella, praktiska och konceptuella. Studien visar på behovet av att utveckla medierande verktyg som inledningsvis synliggör studenternas befintliga syn på och grundläggande kunskaper om akademiskt skrivande för att därefter introducera stöttor med fokus på att utveckla det ämnesintegrerade skrivandet. Noga överväganden krävs angående vilka stöttningsformer som ska användas samt hur och när de ska appliceras under en kurs eller utifrån ett progressionsperspektiv i ett utbildningsprogram.
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| 8. |
- Casetti, C., et al.
(författare)
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Context-aware information dissemination in vehicular networks
- 2011
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Ingår i: EURO-NGI Conf. Next Gener. Internet Networks, NGI - Proc.. - 9781457709173
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Konferensbidrag (refereegranskat)abstract
- With the proliferation of mobile devices and vehicular onboard-units mobility is becoming a key factor in determining the performance of networked systems: both the performance of the infrastructure (e.g., the amount of control traffic) and the performance perceived by the end-users (e.g., access latency, throughput) are influenced by mobility. Mobility, as a manifestation of the physical world, transforms content distribution systems into cyber-physical systems. The efficient design and operation of cyber-physical systems, in general, requires an understanding of the characteristics and of the interactions between the components of the system.
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| 9. |
- Casey, Ashley, et al.
(författare)
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Between hope and happening : Problematizing the M and the P in models-based practice
- 2021
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Ingår i: Physical Education and Sport Pedagogy. - : Taylor & Francis Group. - 1740-8989 .- 1742-5786. ; 26:2, s. 111-122
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Tidskriftsartikel (refereegranskat)abstract
- Background: Advocacy through the work of many scholars in physical education and sport pedagogy highlights a significant direction towards which physical education is moving in light of calls for change. Importantly, and despite the 'newness' of the terms, 'pedagogical models' and 'Models-based Practice' (MbP) are beginning to shape the vocabulary of physical education and sport pedagogy. Purpose: To ask what happens if we take some of the 'good stuff associated with models and apply it in a different way while also taking some of the critical points raised towards models into consideration. Put simply, we (as scholars with different views on MbP) want to step off the beaten track to take a road less travelled and engage in a respectful, agonistic debate about the 'M' and the 'P' in MbP. Key arguments: From a practical perspective, the diversity of the language used in describing models and practices in physical education indicates both a growing excellence and tradition in the field and a degree of confusion. A number of phrases are currently used to identify the same concept with individuals unaware of alternative language use. At the heart of this paper lies the manner in which one interprets the use of the terms 'model', 'practice' and 'practise'. Discussion: Given the 'hope' inherent in pedagogical model development and implementation, we acknowledge that many of the negative or unintended consequences often arise as a result of the 'happening' both in research and in practice. However, by thinking in terms of what it is in students' actions that teachers and researchers should pay attention to in order for them to see what students learn, and in what direction this learning is developing, we are better able to see the outcomes of using MbP. In this way, the hope embedded in the chosen model, and the happenings teachers or researchers aspire to see, could be better aligned. Modelling and practicing through the focus on adaption and negotiation in various complex contexts has the potential to expand the field more than blueprints that potentially narrow the field. Conclusions: By recognising the dangers inherent in an essentialist notion of models (i.e. by nouning or proper nouning them), and by remembering the roles set aside for teachers in the development of pedagogical models, it is important that the practising of MbP always retains a very real sense of becoming. By continuing to problematize the M and the P, and by engaging in respectful and agonistic debate, we are better able to unite the hope and the happening of MbP.
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| 10. |
- Casey, Ashley, et al.
(författare)
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Cooperative learning in physical education encountering Dewey’s educational theory
- 2020
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Ingår i: European Physical Education Review. - : Sage Publications. - 1356-336X .- 1741-2749. ; 26:4, s. 1023-1037
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Tidskriftsartikel (refereegranskat)abstract
- Cooperative learning can be considered as an umbrella term for a number of classroom practices. In this paper we consider the educative nature of cooperative learning in physical education, and we have challenged ourselves to examine how cooperative learning can enhance the education of young people. We do this by revisiting cooperative learning’s Deweyan foundations and hold that such a move would be a constructive way forward for cooperative learning in physical education. We argue that there is a risk, in not going back to its educational roots, that cooperative learning might just become another way to teach, for example, games or sports, and that it currently puts too much emphasis on destination rather than journey. We suggest that using Dewey’s idea of education and experience would add: a situational element, a directional element, a temporal element, a communal element and an educative element. In this way, the use of cooperative learning in physical education can move away from exclusively developing students’ skills, towards an open-ended process of becoming where a diversity of students transform and are being transformed by one another.
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