| 1. |
- Rydell, Jens, et al.
(författare)
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Testing the performances of automated identification of bat echolocation calls : A request for prudence
- 2017
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Ingår i: Ecological Indicators. - : Elsevier BV. - 1470-160X. ; 78, s. 416-420
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Tidskriftsartikel (refereegranskat)abstract
- Echolocating bats are surveyed and studied acoustically with bat detectors routinely and worldwide, yet identification of species from calls often remains ambiguous or impossible due to intraspecific call variation and/or interspecific overlap in call design. To overcome such difficulties and to reduce workload, automated classifiers of echolocation calls have become popular, but their performance has not been tested sufficiently in the field. We examined the absolute performance of two commercially available programs (SonoChiro and Kaleidoscope) and one freeware package (BatClassify). We recorded noise from rain and calls of seven common bat species with Pettersson real-time full spectrum detectors in Sweden. The programs could always (100%) distinguish rain from bat calls, usually (68–100%) identify bats to group (Nyctalus/Vespertilio/Eptesicus, Pipistrellus, Myotis, Plecotus, Barbastella) and usually (83–99%) recognize typical calls of some species whose echolocation pulses are structurally distinct (Pipistrellus pygmaeus, Barbastella barbastellus). Species with less characteristic echolocation calls were not identified reliably, including Vespertilio murinus (16–26%), Myotis spp. (4–93%) and Plecotus auritus (0–89%). All programs showed major although different shortcomings and the often poor performance raising serious concerns about the use of automated classifiers for identification to species level in research and surveys. We highlight the importance of validating output from automated classifiers, and restricting their use to specific situations where identification can be made with high confidence. For comparison we also present the result of a manual identification test on a random subset of the files used to test the programs. It showed a higher classification success but performances were still low for more problematic taxa.
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| 2. |
- Ekdahl, Bertil, et al.
(författare)
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A general architecture for autonomous agents
- 2003
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Ingår i: Proceedings IEEE/WIC International Conference on Intelligent Agent Technology (IAT 2003). - 0769519318 ; , s. 419-423
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Konferensbidrag (refereegranskat)abstract
- Being autonomous (or being an agent) does not describe an effective process and even if we succeeded in characterizing the conditions for being autonomous it would be of no use. Instead, it is the conditions of acting autonomously that should be of concern and the interest should be directed towards systems in which we can find, and possibly define, such acting processes. It turns out that anticipatory systems are the only systems where autonomy is a determining factor. The anticipatory systems are further categorized into two disjoint classes: true anticipatory which systems have a model of their surroundings and semi-anticipatory which systems possess only a description of their surroundings. Here model is used in its semantic sense. It is argued that the only way to catch is to define them as semi-anticipatory. Defining software agent in this way gives a precise characterization of the concept
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| 3. |
- Johansson, Gerd, et al.
(författare)
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A Study of Indoor Aerosol Size Distribution and Attachment of Radon Daughters
- 1983
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Ingår i: Journal of Aerosol Science. - : Elsevier BV. - 0021-8502. ; 14:3, s. 455-458
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Konferensbidrag (refereegranskat)abstract
- The particle size distribution in 11 different dwellings was studied during 5-7 days, samples being taken every 15 min. Large variation in the aerosol concentration has been found. Also the size distribution of the aerosol varies depending on the level of activity in the home, e.g. smoking and cooking. The average area median diameter found in the dwellings was 0.2 ,am. A technique for the measurement of radon daughter distribution on different airborne matter was developed and tested. The method is based on the use of an electrical mobility analyzer and alpha-spectrometry of the radon daughters collected on a fluoropore filter. Some results are presented and discussed.
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