| 1. |
- Andersen, S. J., et al.
(author)
-
Quantifying variability of Large Eddy Simulations of very large wind farms
- 2015
-
In: Wake Conference 2015. - : IOP Publishing. ; , s. 012027-
-
Conference paper (peer-reviewed)abstract
- Large Eddy Simulations are inherently dynamic as the largest scales are resolved and the smallest scales are modeled temporally. This raises challenges for simulations including very large scales such as atmospheric flows, which require very long simulation times. Simple averages fail at capturing these dynamics and potentially yield misleading interpretations concerning the capabilities of different models when tested in blind tests or in benchmarking exercises such as Wakebench, where results from different flow models are compared. This article will present results from very large wind farm simulations using Actuator Disc (AD) and Line (AL) models for two different turbine spacings with turbulent inflow. The results of each numerical flow model include a certain variability, and it will be examined if different models result in comparable probability distributions.
|
|
| 2. |
- Gudmundsson, Henrik, et al.
(author)
-
A covenant of halflings? : developing a roadmap for the european urban transport goal
- 2015
-
In: Proceedings of WCTR SIG G3.
-
Conference paper (peer-reviewed)abstract
- In the 2011 Transport Policy White Paper, the European Commission introduced ten goals for a more competitive and resource efficient transport system. One of the goal concerns urban transport, with the dual targets: “To halve the use of ‘conventionally-fuelled’ cars in urban transport by 2030; and to phase them out by 2050; and “To achieve ‘essentially CO2- free city logistics’ in major urban centres by 2030.” This paper describes how the EU FP7 project TRANSFORUM conducted a stakeholder-driven process to produce a roadmap for the urban transport goal.A main conclusion was that the implementation of a roadmap for urban transport needs to adopt a broad and open approach, given the diversity among member states and cities across Europe. Also it was found that replacing conventional vehicles and fuels is an important but not sufficient strategy to reach the goal. A roadmap to reach towards the ‘halving’ goal would need to engage many cities in shared political commitments to generate a stronger momentum for change. The notion of a ‘Covenant of Halflings’ would be one way to express this need.
|
|
| 3. |
- Gudmundsson, Henrik, et al.
(author)
-
A roadmap for the EU White Paper goal on Urban Transport
- 2015
-
In: Urban Transport XXI. - : WIT Press. - 9781845648985 ; , s. 53-64
-
Conference paper (peer-reviewed)abstract
- In its 2011 Transport Policy White Paper, the European Commission introduced ten targets to be met in order to reach a more competitive and resource efficient transport system. The following dual goal focused on urban transport and commuting: “To halve the use of ‘conventionally-fuelled’ cars in urban transport by 2030; and to phase them out by 2050; and to achieve “essentially CO2-free city logistics in major urban centres by 2030.” The question driving the research behind this paper is how to realise this dual urban transport goal for 2030, taking into consideration existing trends, available policy options, the diverse interests of stakeholders involved in urban mobility in Europe.The paper draws on data gathered in the EU FP7 TRANSFORuM project, including workshop dialogues with stakeholders representing different interests in and perspectives on urban transport and mobility. The main result is a roadmap that proposes a broad strategy to answer the question “Who has to do what, by when” to achieve the urban transport goal. The roadmap includes detailed proposals for action and milestones at different levels of decision making. This paper will describe the process of consultations and the outcomes of the roadmap process and will also discuss the perspectives for implementation.
|
|
| 4. |
- Häggström, Ida, et al.
(author)
-
The influence of time sampling scheme on kinetic parameters obtained from compartmental modeling of a dynamic PET study : a Monte Carlo study
- 2012
-
In: IEEE Nuclear Science Symposium Conference Record. - Anaheim : IEEE conference proceedings. - 9781467320306 ; , s. 3101-3107
-
Conference paper (peer-reviewed)abstract
- Compartmental modeling of dynamic PET data enables quantification of tracer kinetics in vivo, through the obtained model parameters. The dynamic data is sorted into frames during or after the acquisition, with a sampling interval usually ranging from 10 s to 300 s. In this study we wanted to investigate the effect of the chosen sampling interval on kinetic parameters obtained from a 2-tissue model, in terms of bias and standard deviation, using a complete Monte Carlo simulated dynamic F-18-FLT PET study. The results show that the bias and standard deviation in parameter K-1 is small regardless of sampling scheme or noise in the time-activity curves (TACs), and that the bias and standard deviation in k(4) is large for all cases. The bias in V-a is clearly dependent on sampling scheme, increasing for increased sampling interval. In general, a too short sampling interval results in very noisy images and a large bias of the parameter estimate, and a too long sampling interval also increases bias. Noise in the TACs is the largest source of bias.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- Karlsson, Björn, et al.
(author)
-
NORDIC COURSE DEVELOPMENT COOPERATION IN AN EMERGING FIELD OF ENGINEERING
- 2022
-
In: 18th CDIO International Conference, CDIO 2022 - Proceedings. - : Reykjavík University. - 9789935965561 ; , s. 659-669
-
Conference paper (peer-reviewed)abstract
- Four decades ago, a specific engineering BSc study program in Fire Safety Engineering was formed at Lund University, Sweden, and several Nordic universities have since included courses on such subjects in their own BSc og MSc programmes. The field of fire safety engineering encompasses topics from a wide range of engineering disciplines, including mathematics, physics, chemistry and advanced engineering courses such as heat transfer, thermodynamics and fluid dynamics. It is not immediately obvious how to balance the need for knowledge from fundamental, applied and specific courses to be taught within the discipline of fire safety engineering. Long standing cooperation across 12 Nordic universities and research institutions has made this distinction clearer and most recently this network secured Nordic funding for three years for a specific cooperation program in education, including PhD exchange programs and the development of a summer school for students of engineering, focusing on fire safety and energy. Specifically, four of these universities, through the authors of this paper, have been cooperating for a number of years within one of the key courses called "Enclosure Fire Dynamics", the study of how a fire develops in a building and how engineering methods based on classical physics and chemistry can be used to simulate the environment due to fire, allowing engineers and designers to test and compare various possible design solutions regarding building fire safety. This has required careful development of educational material in close cooperation between Nordic universities, following the CDIO principles. The fruitful cooperation has resulted in the production of comprehensive educational material such as textbooks, homework assignments, laboratory instructions and computer labs, to name a few examples of results. Most of the material is free of charge and available on the internet. This paper provides an example of how this has been achieved by a cross-Nordic collaboration on providing and developing educational material in an emerging engineering discipline.
|
|
| 9. |
|
|
| 10. |
|
|
