| 51. |
- Löfgren, Johan, 1983
(author)
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Local Sea Level Observations Using Reflected GNSS Signals
- 2014
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Doctoral thesis (other academic/artistic)abstract
- Sea level rise due to global warming is predicted to have a large impact on human society, especially for populations living in coastal regions and on islands. It is therefore of great importance to monitor the sea level and to increase the understanding of the local hydrodynamic and meteorological responses to a global sea level rise.The focus of this thesis is to estimate the local sea level using Global Navigation Satellite System (GNSS) signals reflected off the sea surface. These signals were recorded in two different ways using a GNSS tide gauge at the Onsala Space Observatory, consisting of standard geodetic-type commercially off-the-shelf GNSS equipment. First, the phase-delay of the reflected GNSS signals were recorded directly with a receiver connected to a nadir-looking antenna. Together with the phase-delay of the direct signals, recorded with a receiver connected to a zenith-looking antenna, standard geodetic analysis provided GNSS sea level observations. Second, the Signal-to-Noise Ratio (SNR) recorded with the receiver connected to the zenith-looking antenna, provided an indirect measurement of the reflected GNSS signals, as the reflected signals interfered with the direct GNSS signals and affected the recorded observables. From analysis of the multipath oscillations, an additional type of sea level observation was possible. Furthermore, the SNR-analysis method allowed other GNSS stations, located close to the ocean, in different parts of the world to become GNSS tide gauges.The GNSS-derived sea level from the GNSS tide gauge at the observatory was compared with independent observations of sea level from co-located traditional tide gauges, showing a high level of agreement with correlation coefficients of 0.89-0.99. The sea level results from the phase-delay analysis performed better with respect to the traditional sea level records than the results from the SNR-analysis. As an example, the Root-Mean-Square (RMS) differences from 1 month of observations between the GNSS-derived sea level (using frequency band L1) and the sea level from the co-located tide gauge were 3.2-3.5 cm and 4.0-4.7 cm for the phase-delay analysis and the SNR-analysis, respectively.Sea level results applying the SNR-analysis for data of 5 different GNSS stations around the world were compared to independent co-located traditional tide gauge records. The results showed RMS differences on the order of 6.2 cm for stations with low tidal ranges (up to 165 cm) and 43 cm for stations with high tidal ranges (up to 772 cm). In this case, an extended SNR-analysis approach was applied, modelling a time dependent sea level.
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| 52. |
- Cullinane, Kevin
(author)
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Targeting the Environmental Sustainability of European Shipping: The Need for Innovation in Policy and Technology
- 2014
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Reports (other academic/artistic)abstract
- At their Summit meeting in Gothenburg in June 2001, Europe’s heads of state and government reached agreement on a European strategy for sustainable development. The social and economic dimensions of the Lisbon strategy were complemented by an environmental dimension. Thus, the Gothenburg Summit represents a breakthrough for sustainable development in the European Union (EU). The University of Gothenburg and Chalmers University of Technology made a commitment to serve, through the joint Centre for Environment and Sustainability (GMV), as a hub for research and scientific follow up of the EU sustainable development strategy. In order to fulfill this commitment, the two universities have established a European Panel for Sustainable Development (EPSD), together with Lund University. In addition, individual members from other universities and research institutes contribute to the work of the Panel. The Centre for Environment and Sustainability (GMV) in Gothenburg is the lead organization in the EPSD. The first report produced by the Panel in 2004 was “From Here to Sustainability – Is the Lisbon/Gothenburg Agenda Delivering?” This was put forward as an independent contribution from academics to the mid-term review of the Lisbon strategy for growth, competitiveness and jobs. The second report “Make the Kok-report sustainable” was produced by the EPSD as a reflection on, and a response to, the mid-term review on the Lisbon strategy chaired by the former Prime Minister of the Netherlands, Wim Kok. The third report “Towards a Smart Growth Strategy for Sustainable Development” aimed to contribute to the re-launch of the EU sustainable development strategy. It contained a critical assessment of “A Platform for Action”, the proposal for an updated strategy put forward by the European Commission. The fourth report “TAKING CHILDREN SERIOUSLY – How the EU can Invest in Early Childhood Education for a Sustainable Future” presented research on children’s interest and ability to understand questions on the social, economic and environmental dimensions of sustainable development. The present report “Targeting the Environmental Sustainability of European Shipping: The Need for Innovation in Policy and Technology” has emerged from a background survey with the aim of mapping what is being done on sustainable shipping within the European Union. A wide scope of strategic EU policy sectors and documents, including existing directives, legislation and regulations on shipping were scrutinized to describe the actual knowledge framework. The background study defines areas where new research could contribute in closing knowledge gaps, and gives a compilation of directives and policy documents concerning sustainable shipping in a European perspective. Based on a definition of sustainable shipping that include all three pillars of sustainable development, the present report presents a holistic view and strategies for achieving a sustainable shipping industry. The report provides scientifically based knowledge of various aspects that affect sustainability at sea, such as particles, greenhouse gases, ship wrecks, ship recycling, and intermodality, as well as a comprehensive overview and updates on regulations. These various areas are presented as separate chapters and solid recommendations are presented on future actions (on EU and international level) to make the shipping industry in Europe a sustainable business. The main author of the report was Prof. Kevin Cullinane, Edinburgh Napier University, UK. The separate chapters in the report were written by Lars Barregård, University of Gothenburg, Erik Fridell, Hulda Winnes, IVL Swedish Environmental Research Institute (Particle emission from ships); Hannes Johnson 1 , Chalmers University of Technology (GHG Emissions and the Energy Efficiency Gap in Shipping); Peter Domini, Stena Metall (Ship Recycling: A Global Issue); Lars Barregård, University of Gothenburg (The Health Risks Associated with the Ship Breaking Industry); Ida-Maja Hassellöv, Chalmers University of Technology (Potentially Polluting Shipwrecks); Abhinayan Basu Bal, University of Gothenburg (Sustainable Intermodal Transport with Short Sea Shipping in the EU); A number of researchers and knowledgeable persons have constituted a reference group and further contributed to the report: Katarina Gårdfeldt, Maria Svane, Dan Strömberg, and Jonas Norrman, GMV, Gothenburg; Karin Andersson, Björn Södahl, Josefin Borg, and Oliver Lindqvist, Chalmers University of Technology; Lars Göran Malmberg, Johan Boman, Johan Woxenius, and Mattias Hallquist, University of Gothenburg, Christer Forsgren, Stena Metall; Anders Carlberg, Vgregion; Carl Carlsson, Swedish Shipowners Association, and Axel Wenblad, Former GD National Board of Fisheries. Dan Strömberg, and Maria Svane, University of Gothenburg, have been invaluable during the course of the project and as editors of the publication. The report has been endorsed by the EPSD. Bo Samuelsson Chairman of EPSD
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| 53. |
- Löfgren, Johan, 1983, et al.
(author)
-
High-rate local sea level monitoring with a GNSS-based tide gauge
- 2010
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In: Proceedings of the 2010 IEEE International Geoscience and Remote Sensing Symposium, Proceedings DVD-ROM. - 9781424495665 ; , s. 3616-3619
-
Conference paper (other academic/artistic)abstract
- We present first results from the analysis of high-rate observations with a GNSS-based tide gauge at the Onsala Space Observatory. The goal is to determine local sea level with high temporal resolution. The GNSS-based tide gauge makes use of right-hand circular polarized GNSS signals that are directly received and left-hand circular polarized GNSS signals that are reflected from the sea surface. An experimental setup of the GNSS-based tide gauge was operated in the spring of 2010 and data were recorded with a sampling rate of 20 Hz.We analyzed data decimated to 1 Hz using different temporal resolution between 5 and 240 seconds, and the resulting time series of local sea level were compared to each other and to results from two stilling well gauges. The comparison with the data from the stilling well gauges shows a common trend.The comparison of the results from analyses with different temporal resolution show consistent results. There is also an indication that the GNSS-based tide gauge might be able to give information on the sea surface state.
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| 54. |
- Löfgren, Johan, 1983, et al.
(author)
-
Monitoring coastal sea level using reflected GNSS signals
- 2011
-
In: Advances in Space Research. - : Elsevier BV. - 1879-1948 .- 0273-1177. ; 47:2, s. 213-220
-
Journal article (peer-reviewed)abstract
- A continuous monitoring of coastal sea level changes is important for human society since it is predicted that up to 332 million people in coastal and low-lying areas will be directly affected by flooding from sea level rise by the end of the 21st century. The traditional way to observe sea level is using tide gauges that give measurements relative to the Earth’s crust. However, in order to improve the understanding of the sea level change processes it is necessary to separate the measurements into land surface height changes and sea surface height changes. These measurements should then be relative to a global reference frame. This can be done with satellite techniques, and thus a GNSS-based tide gauge is proposed. The GNSS-based tide gauge makes use of both GNSS signals that are directly received and GNSS signals that are reflected from the sea surface. An experimental installation at the Onsala Space Observatory (OSO) shows that the reflected GNSS signals have only about 3 dB less signal-to-noise-ratio than the directly received GNSS signals. Furthermore, a comparison of local sea level observations from the GNSS-based tide gauge with two stilling well gauges, located approximately 18 km and 33 km away from OSO, gives a pairwise root-mean-square agreement on the order of 4 cm. This indicates that the GNSS-based tide gauge gives valuable results for sea level monitoring.
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| 55. |
- Abarenkov, Kessy, et al.
(author)
-
Annotating public fungal ITS sequences from the built environment according to the MIxS-Built Environment standard – a report from a May 23-24, 2016 workshop (Gothenburg, Sweden)
- 2016
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In: MycoKeys. - : Pensoft Publishers. - 1314-4057 .- 1314-4049. ; 16, s. 1-15
-
Journal article (peer-reviewed)abstract
- Recent molecular studies have identified substantial fungal diversity in indoor environments. Fungi and fungal particles have been linked to a range of potentially unwanted effects in the built environment, including asthma, decay of building materials, and food spoilage. The study of the built mycobiome is hampered by a number of constraints, one of which is the poor state of the metadata annotation of fungal DNA sequences from the built environment in public databases. In order to enable precise interrogation of such data – for example, “retrieve all fungal sequences recovered from bathrooms” – a workshop was organized at the University of Gothenburg (May 23-24, 2016) to annotate public fungal barcode (ITS) sequences according to the MIxS-Built Environment annotation standard (http://gensc.org/mixs/). The 36 participants assembled a total of 45,488 data points from the published literature, including the addition of 8,430 instances of countries of collection from a total of 83 countries, 5,801 instances of building types, and 3,876 instances of surface-air contaminants. The results were implemented in the UNITE database for molecular identification of fungi (http://unite.ut.ee) and were shared with other online resources. Data obtained from human/animal pathogenic fungi will furthermore be verified on culture based metadata for subsequent inclusion in the ISHAM-ITS database (http://its.mycologylab.org).
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| 56. |
- Ruiz Zúñiga, Enrique, 1986-, et al.
(author)
-
A simulation-based multi-objective optimization approach for production and logistics considering the production layout
- 2016
-
In: Proceedings of the 7th Swedish Production Symposium.
-
Conference paper (peer-reviewed)abstract
- Manufacturing sectors in Sweden have a long tradition and represent a significant share of the national gross domestic product and the export values. Most of the Swedish manufacturing companies have gone through a modernization and adaptation process in order to be able to compete on a globalized market. Many plants, however, still have non-optimized shop floors as a consequence of the shop floors being adapted over time without redesigning its production and logistics flows and with a lack of an overall strategy. To support the optimization of shop floors, this paper suggests the combined use of Discrete-Event Simulation and Simulation-Based Multi-objective Optimization. The aim of the paper is to analyze a simulation methodology that supports the optimization of shop floors by considering production and logistics flows along with the shop floor layout. The methodology is intended to contribute to significantly increase the productivity and efficiency of the Swedish manufacturing industry and help companies to survive on the globalized market. Through a case study, the paper shows that the proposed methodology is useful in practice and that it provides a decision support system for manufacturing companies.
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| 57. |
- Ruiz Zúñiga, Enrique, 1986-, et al.
(author)
-
Production Logistics Design and Development Support : A Simulation-Based Optimization Case Study (WIP)
- 2016
-
In: SummerSim'16, 2016 July 24-27, Palais des congres de Montreal (Montreal Convention Center) | Montreal, Quebec, Canada. - : The Society for Modeling and Simulation International. - 9781510824249 ; , s. 56:1-56:6
-
Conference paper (peer-reviewed)abstract
- Manufacturing sectors in Sweden have a long history that leads to common non-optimized flows on the shop floor. Especially when having a really high product mix and a low-volume of customized products, a great deal of effort with respect to flow optimization is needed to stay present and compete in the globalized market. The goal of this project is to support the design and development of the implementation of new production systems and logistics flows considering the shop floor plant layout of a Swedish middle-size water pumps factory. In this paper, with the help of different types of simulation models and optimization, some results of a new technologically adapted production line are analyzed and relevant information and potential improvements in the production are found. The further development of optimization studies using the exiting simulation models is stated as ongoing and future work. The obtained and potential results can serve for decision makers and stakeholders to apply changes and adaptations in the system considering the mid and long term goals of the company.
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| 58. |
- Sandberg, David, 1980, et al.
(author)
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The impact of sleepiness on lane positioning in truck driving
- 2013. - 1
-
In: Driver Distraction and Inattention. - Farnham : Ashgate. - 9781409425854 - 9781315578156 ; , s. 405-416, s. 405-416
-
Book chapter (peer-reviewed)abstract
- This chapter concerns the detection of sleepiness in truck drivers. Data obtained from a driver sleepiness study involving real-world driving are used in order to analyse the performance of several sleepiness indicators based on driving behavior; such as, for example, variability in lateral position and heading angle. Contrary to the results obtained for passenger cars, for heavy trucks it is found that indicators based on variability provide little or no information; their performance does not rise significantly above chance levels.However, the data indicate that there is a significant difference in the average lane position for sleepy and alert drivers, respectively, such that a sleepy driver generally places the vehicle closer (by about 0.2 m) to the centre of the road than an alert driver. The analysis also shows a significant, monotonous, increase in average lateral position (measured from the right, outer, lane boundary towards the lane centre) between the four cases of (i) daytime alert driving, (ii) daytime sleepy driving, (iii) night-time alert driving and (iv) nighttime sleepy driving.
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| 59. |
- Khodadad, Davood, et al.
(author)
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Single shot dual-wavelength digital holography : calibration based on speckle displacements
- 2014
-
In: International Journal of Optomechatronics. - : Informa UK Limited. - 1559-9612 .- 1559-9620. ; 8:4, s. 326-339
-
Journal article (peer-reviewed)abstract
- We present a calibration method which allows single shot dual wavelength online shape measurement in a disturbed environment. Effects of uncontrolled carrier frequency filtering are discussed as well. We demonstrate that phase maps and speckle displacements can be recovered free of chromatic aberrations. To our knowledge, this is the first time that a single shot dual wavelength calibration is reported by defining a criteria to make the spatial filtering automatic avoiding the problems of manual methods. The procedure is shown to give shape accuracy of 35 µm with negligible systematic errors using a synthetic wavelength of 1.1 mm.
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| 60. |
- Blennow, Kristina, et al.
(author)
-
Societal impacts of storm damage
- 2013
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In: Living with Storm Damage to Forests. What science can tell us. - 9789525980097 ; :3, s. 70-77
-
Book chapter (other academic/artistic)
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