| 1. |
- Grönlund, Rasmus, et al.
(författare)
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Fluorescence lidar multispectral imaging for diagnosis of historical monuments - Övedskloster, a Swedish case study
- 2007
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Ingår i: Springer Proceedings in Physics. - 0930-8989. ; 116, s. 583-591
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Konferensbidrag (refereegranskat)abstract
- A fluorescence lidar measurement has been performed on the castle Övedskloster in Sweden. A mobile system from the Lund University was placed at ~40 m distance from the sandstone façade. The lidar system, which uses a frequency-tripled Nd:YAG laser with a 355-nm pulsed beam, induces fluorescence in each target point. Areas were studied by using whisk-broom scans. The possibility of detecting biodeteriogens on the surface and characterization of materials was confirmed. The method can be a tool for conservation planning and status control of the architectural heritage where fluorescence light can point out features that are not normally visible under natural illumination.
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| 2. |
- Grönlund, Rasmus, et al.
(författare)
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Laser-Induced Fluorescence for Assessment of Cultural Heritage
- 2006
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Konferensbidrag (refereegranskat)abstract
- Remote imaging measurements of laser-induced fluorescence have been performed, with application towards cultural heritage. Measurement campaigns have been performed at, e.g., the Coliseum in Rome. Differences in fluorescence spectra from different points were found and images corresponding to different features could be produced for thematic mapping.
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| 3. |
- Grönlund, Rasmus, et al.
(författare)
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Laser-induced fluorescence imaging for studies of cultural heritage - art. no. 66180P
- 2007
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Ingår i: O3A: Optics for Arts, Architecture, and Archaeology. - : SPIE. - 1996-756X .- 0277-786X. - 9780819467607 ; 6618, s. 6180-6180
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Konferensbidrag (refereegranskat)abstract
- Laser-induced fluorescence for remote imaging of historical monuments is an established technique, which in this work has been used in measurement campaigns at the Coliseum and the Baptistery of San Giovanni in Laterano in Rome, Italy. The results presented here are examples that show that biodeteriogens can be monitored and that. materials can be identified. Also, cleaned and soiled areas on the stone can be localized and differences between soiling can be found, which may be useful in the sustainable conservation for mapping and evaluation.
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| 4. |
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| 5. |
- Grönlund, Rasmus, et al.
(författare)
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Remote laser-induced fluorescence imaging for assessment of cultural heritage
- 2005
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Ingår i: 2005 Conference on Lasers and Electro-Optics Europe. - 0780389743 ; , s. 685-685
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Konferensbidrag (refereegranskat)abstract
- In this paper, we propose to perform remote laser-induced fluorescence imaging for assessment of cultural heritage. The experiments are performed using the lidar system consist of frequency-tripled Nd:YAG laser at 355 nm with a spot size of ~4 cm diameter and the signal is collected using a coaxial 40-cm-diameter Newtonian telescope. The fluorescence light is focused into an optical fibre and guided a time-gated optical multichannel analyser system, where the fluorescence spectrum is recorded. Then the laser directed to the next point and thus a fluorescence image can be produced
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| 6. |
- Grönlund, Rasmus, et al.
(författare)
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Remote Multicolor Excitation Laser-Induced Fluorescence Imaging
- 2006
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Ingår i: Laser Chemistry. - : Hindawi Limited. - 0278-6273 .- 1476-3516. ; 2006, s. 57934-57934
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Tidskriftsartikel (refereegranskat)abstract
- Remote laser-induced fluorescence of stone materials was performed with application towards cultural heritage. Fluorescence was induced in targets ∼60 m from a mobile lidar laboratory by ultraviolet laser light, either from a frequency-tripled Nd:YAG laser or from an optical parametric oscillator system. Analysis was performed on combined spectra from the different excitation wavelengths and it was noted that important additional information can be gained when using several excitation wavelengths.
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| 7. |
- Hällström, Elin, et al.
(författare)
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Narrative retells in Swedish school-aged children – a clinical pilot study
- 2023
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Ingår i: Logopedics, Phoniatrics, Vocology. - : Taylor & Francis. - 1401-5439 .- 1651-2022. ; 48:1, s. 12-22
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Tidskriftsartikel (refereegranskat)abstract
- AimThe aim of this pilot study was to evaluate two new retelling tasks intended for clinical use in terms of language sample size, effects of picture support, and order of presentation.MethodsForty Swedish-speaking children in grades 4–6 participated in the study, 31 children with typical language development (TLD, mean age 11;1), and nine children with developmental language disorder (DLD, mean age 11;5). Two oral retells, one with and one without picture support, were analyzed with regards to productivity, syntactic complexity, basic Story Grammar (SG) units, and Internal Responses (IR).ResultsResults showed no systematic order effects in the TLD group, although this needs to be investigated further, and good inter-rater reliability. Both tasks elicited sufficiently large language samples, except from one participant with DLD whose samples were excluded from subsequent comparisons. When appropriate, data were analyzed with ANOVA (productivity, mean length of C-unit/MLCU), otherwise t-tests (TLD-group) or non-parametric tests (DLD-group) were used. As expected, retells from participants with DLD were shorter, with shorter MLCU and fewer SG units compared to the TLD group. There were also task effects: in the task with picture support, all participants had longer MLCU, and participants with TLD also showed a higher proportion of subordinate clauses, indicating that pictures may function as a support for syntactic complexity. The task without picture support, on the other hand, elicited more C-units indicated by a significant main effect, and more SG units, which was a significant effect in the TLD group.ConclusionsWe conclude that both tasks might be useful for Swedish speech-language pathologists.
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| 8. |
- Hällström, Jenny, et al.
(författare)
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Documentation of soiled and biodeteriorated facades: a case study on the Coliseum, Rome, using hyperspectral imaging fluorescence lidars
- 2009
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Ingår i: Journal of Cultural Heritage. - : Elsevier BV. - 1778-3674 .- 1296-2074. ; 10:1, s. 106-115
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Tidskriftsartikel (refereegranskat)abstract
- Non-invasive documentation of historic façades with fluorescence lidar techniques can provide helpful information for the cultural heritage sector, especially when large areas outdoors are to be examined. This paper presents a case study on the Coliseum, Rome, where both cleaned and heavily soiled areas of the monument were scanned and analysed with two fluorescence lidar systems. Biodeterioration processes have also been addressed during the experiment with the aim of assessing the colonisation extent on selected areas of the monument. Results show the usefulness of a mobile fluorescence lidar system for documentation and survey of large surfaces with complex conditions without limiting the public access to the monument.
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| 9. |
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| 10. |
- Hällström, Jenny, et al.
(författare)
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Fluorescence lidar multispectral imaging for historical monuments, the Lateran Baptistery interdisciplinary project
- 2006
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Ingår i: [Host publication title missing].
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Konferensbidrag (refereegranskat)abstract
- Introduction For the future conservation, restoration and daily maintenance the need for developing non-destructive and in-situ investigations is vital. At Lund University in Sweden an interdisciplinary research project is being held aiming at, with the help of a mobile system of remote fluorescence lidar, survey and study the facades of historic monuments, and to develop the method and its application for the cultural heritage sector. Earlier studies using the fluorescence lidar technique has been undertaken at, for example, Parma, Lund and Pisa Cathedral. During the winter 2005 two field studies were performed in Rome, one on parts of the Flavian Amphitheatre Coliseum, and the other on parts of the Lateran Baptistery. The studies were performed from remote and with no need for taking samples. The aim was to identify different materials, different biodeteriogens and other objectives not yet visible for the human eye. Objectives for the project The primary aim of the research project is to analyse the potential of the fluorescence lidar technique in building investigation. Furthermore, to establish a scientific remote-sensing method for surveying and analysing the historical facade that is non-destructive and takes place in-situ. The aim of the fluorescence lidar method is to use point-monitoring and scanning of areas which can provide multispectral images in order to identify different types of stones, their origin, different biodeteriogens and conservation chemicals. A specific aim of the project is to develop the method in comparison with existing documentation methods, to improve the understanding of the built heritage and to provide a basis for new interventions, documentation and maintenance. Methods Fluorescence techniques make it possible to extend the application of fluorescence spectroscopy to the outdoor environment (remote sensing), with sometimes large distances and uncontrollable background light. The ultra-violet laser pulse used in the experiments (usually 355 nm and 308 nm) is directed to the point of interest, exciting atoms and molecules in the material, which then relax emitting fluorescence light. The unique fluorescence spectra from each point taken can then be analysed and identified. By applying a function to the different spectra, each point is assigned a value, and from this a false-colour coded image can be produced, indicating points with different properties, revealing e.g. different materials and earlier treatments. Lateran Baptistery field study The study of the Lateran Baptistery in Rome is a co-operation between Lund University, the Swedish Institute in Rome, CNR-IFAC in Florence, and the research project led by Dr. O. Brandt and Dr. G. Eriksdotter, from the Swedish Institute, the Vatican Museums and the Pontifical Institute of Christian Archaeology, also involving Italian and Swedish archaeology students who has performed a stratigraphic analysis during 2005. The Baptistery, part of the San Giovanni in Lateran church complex, dates back to the fourth hundred-century AC. The analysis from the lidar campaign and the stratigraphic studies are now being cross-examined and the analysis aims to identify brick material and if possible distinguish different building and restoration phases of the baptistery.
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