| 1. |
- Elmusrati, M, et al.
(författare)
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Wireless automation : opportunities and challenges
- 2007
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Ingår i: Finnish Automation Days.
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Konferensbidrag (refereegranskat)abstract
- In this paper we discuss the opportunities of replacing wirelines by wireless connections in automation systems.However, there are several challenges inherently associated with these opportunities. One of the major challengesis how to select a proper wireless connection protocol that achieves at least the minimum requirements ofthe automation system. These system requirements are discussed in the paper. Some wireless communicationsystems which could be used for wireless automation are briefly revised. Finally, we discuss the applicability ofcontemporary wireless protocols for wireless automation and whether a new wireless protocol needs to be definedfor wireless automation systems. The augmentation of wireless technology to automation systems will improvethe performance of those systems and also many new applications may be defined.
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| 2. |
- Hussein, T., et al.
(författare)
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Evaluation and modeling of the size fractionated aerosol particle number concentration measurements nearby a major road in Helsinki - Part II : Aerosol measurements within the SAPPHIRE project
- 2007
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 7:15, s. 4081-4094
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Tidskriftsartikel (refereegranskat)abstract
- This study presents an evaluation and modeling exercise of the size fractionated aerosol particle number concentrations measured nearby a major road in Helsinki during 23 August-19 September 2003 and 14 January-11 February 2004. The available information also included electronic traffic counts, on-site meteorological measurements, and urban background particle number size distribution measurement. The ultrafine particle (UFP, diameter < 100 nm) number concentrations at the roadside site were approximately an order of magnitude higher than those at the urban background site during daytime and downwind conditions. Both the modal structure analysis of the particle number size distributions and the statistical correlation between the traffic density and the UFP number concentrations indicate that the UFP were evidently from traffic related emissions. The modeling exercise included the evolution of the particle number size distribution nearby the road during downwind conditions. The model simulation results revealed that the evaluation of the emission factors of aerosol particles might not be valid for the same site during different time.
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| 3. |
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| 4. |
- Isaksson, E, et al.
(författare)
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Ice cores from Svalbard :useful archives of past climate and pollution history.
- 2003
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Ingår i: Physics and chemistry of the earth. Part A. - : Elsevier BV. - 1464-1895 .- 1873-4642 .- 1474-7065. ; 28:28-32, s. 1217-1228
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Tidskriftsartikel (refereegranskat)abstract
- Ice cores from the relatively low-lying ice caps in Svalbard have not been widely exploited in climatic and environmental studies due to uncertainties about the effect of melt water percolation. However, results from two recent Svalbard ice cores, at Lomonosovfonna (1250 m asl) and Austfonna (750 m asl), have shown that with careful site selection, high-resolution sampling and multiple chemical analyses, it is possible to recover ice cores with partly preserved annual signals. These cores are estimated to cover at least the past 600 years and have been dated using a combination of known reference horizons and glacial modeling. The δ18O data from both Lomonosovfonna and Austfonna ice cores suggest that the 20th century was the warmest during the past 600 years. A comparison of the ice core and sea ice records from this period suggests that sea ice extent and Austfonna δ18O are linked over the past 400 years. This may reflect the position of the storm tracks and their direct influence on the relatively low altitude Austfonna. Lomonosovfonna may be less sensitive to such changes and primarily record atmospheric changes due to its higher elevation. The anthropogenic influence on Svalbard environment is illustrated by increased levels of non-sea-salt sulphate, nitrate, acidity, fly-ash and organic contaminants particularly during the second half of 1900s. Decreased concentrations of some components in recent decades most likely reflect emission and use restrictions. However, some current-use organic pesticide compounds show growing concentrations in near surface layers.
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| 5. |
- Pohjola, M. A., et al.
(författare)
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Evaluation and modelling of the size fractionated aerosol particle number concentration measurements nearby a major road in Helsinki - Part I : Modelling results within the LIPIKA project
- 2007
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 7:15, s. 4065-4080
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Tidskriftsartikel (refereegranskat)abstract
- A field measurement campaign was conducted near a major road ""Itavayla in an urban area in Helsinki in 17-20 February 2003. Aerosol measurements were conducted using a mobile laboratory ""Sniffer"" at various distances from the road, and at an urban background location. Measurements included particle size distribution in the size range of 7 nm-10 mu m (aerodynamic diameter) by the Electrical Low Pressure Impactor (ELPI) and in the size range of 3-50 nm ( mobility diameter) by Scanning Mobility Particle Sizer (SMPS), total number concentration of particles larger than 3 nm detected by an ultrafine condensation particle counter (UCPC), temperature, relative humidity, wind speed and direction, driving route of the mobile laboratory, and traffic density on the studied road. In this study, we have compared measured concentration data with the predictions of the road network dispersion model CAR-FMI used in combination with an aerosol process model MONO32. For model comparison purposes, one of the cases was additionally computed using the aerosol process model UHMA, combined with the CAR-FMI model. The vehicular exhaust emissions, and atmospheric dispersion and transformation of fine and ultrafine particles was evaluated within the distance scale of 200m (corresponding to a time scale of a couple of minutes). We computed the temporal evolution of the number concentrations, size distributions and chemical compositions of various particle size classes. The atmospheric dilution rate of particles is obtained from the roadside dispersion model CAR-FMI. Considering the evolution of total number concentration, dilution was shown to be the most important process. The influence of coagulation and condensation on the number concentrations of particle size modes was found to be negligible on this distance scale. Condensation was found to affect the evolution of particle diameter in the two smallest particle modes. The assumed value of the concentration of condensable organic vapour of 10(12) molecules cm(-3) was shown to be in a disagreement with the measured particle size evolution, while the modelling runs with the concentration of condensable organic vapour of 10(9)-10(10) molecules cm(-3) resulted in particle sizes that were closest to the measured values.
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| 6. |
- van der Wel, Gerko, et al.
(författare)
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Using high-resolution tritium profiles to quantify the effects of melt on two Spitsbergen ice cores
- 2011
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Ingår i: Journal of Glaciology. - : International Glaciological Society. - 0022-1430 .- 1727-5652. ; 57:206, s. 1087-1097
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Tidskriftsartikel (refereegranskat)abstract
- Ice cores from small ice caps provide valuable climatic information, additional to that of Greenland and Antarctica. However, their integrity is usually compromised by summer meltwater percolation. To determine to what extent this can affect such ice cores, we performed high-resolution tritium measurements on samples from two ice cores from Spitsbergen covering the period AD1955-75. The very sharp and distinct peaks in the tritium precipitation record are subject to several post-depositional processes. We developed a model that uses the precipitation record as input and incorporates the three most important processes (radioactive decay, isotope diffusion and meltwater percolation). Results are compared with measured tritium and density profiles. Both ice-core records contain sharp bomb peaks in the pre-1963 period. It is shown that these peaks would be much smoother in the absence of melt. In this case the main effect of melt and the refreezing of percolation water is the formation of ice layers that form barriers for firn diffusion; thus melt paradoxically results in better preservation of the annual isotope signals. Conversely, for the period after 1963 the main effect of melt is a stronger smoothing of the tritium profiles.
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| 7. |
- Den Ouden, M. A. G., et al.
(författare)
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Stand-alone single-frequency GPS ice velocity observations on Nordenskiöldbreen, Svalbard
- 2010
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Ingår i: The Cryosphere. - : Copernicus GmbH. - 1994-0416 .- 1994-0424. ; 4:4, s. 593-604
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Tidskriftsartikel (refereegranskat)abstract
- Precise measurements of ice-flow velocities are necessary for a proper understanding of the dynamics of glaciers and their response to climate change. We use stand-alone single-frequency GPS receivers for this purpose. They are designed to operate unattended for 1–3 years, allowing uninterrupted measurements for long periods with hourly temporal resolution. We present the system and illustrate its functioning using data from 9 GPS receivers deployed on Nordenskiöldbreen, Svalbard, for the period 2006–2009. The accuracy of the receivers is 1.62 m based on the standard deviation in the average location of a stationary reference station (NBRef). Both the location of NBRef and the observed flow velocities agree within one standard deviation with DGPS measurements. Periodicity (6, 8, 12, 24 h) in the NBRef data is largely explained by the atmospheric, mainly ionospheric, influence on the GPS signal. A (weighed) running-average on the observed locations significantly reduces the standard deviation and removes high frequency periodicities, but also reduces the temporal resolution. Results show annual average velocities varying between 40 and 55 m yr−1 at stations on the central flow-line. On weekly to monthly time-scales we observe a peak in the flow velocities (from 60 to 90 m yr−1) at the beginning of July related to increased melt-rates. No significant lag is observed between the timing of the maximum speed between different stations. This is likely due to the limited temporal resolution after averaging in combination with the relatively small distance (max. ±13 km) between the stations.
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| 8. |
- Helenius, K., et al.
(författare)
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Overlap between EEC and AEC syndrome and immunodeficiency in a preterm infant with a TP63 variant
- 2023
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Ingår i: European Journal of Medical Genetics. - : Elsevier BV. - 1769-7212. ; 66:5
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Tidskriftsartikel (refereegranskat)abstract
- Pathogenic variants in the transcription factor TP63 gene cause a variety of clinical phenotypes, such as ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome and ankyloblepharon-ectodermal dysplasia-clefting (AEC) syndrome. Historically, TP63-related phenotypes have been divided into several syndromes based on both the clinical presentation and location of the pathogenic variant on the TP63 gene. This division is complicated by significant overlap between syndromes.Here we describe a patient with clinical characteristics of different TP63-associated syndromes (cleft lip and palate, split feet, ectropion, erosions of the skin and corneas), associated with a de novo heterozygous pathogenic variant c.1681 T>C, p.(Cys561Arg) in exon 13 of the TP63 gene. Our patient also developed enlargement of the left-sided cardiac compartments and secondary mitral insufficiency, which is a novel finding, and immune deficiency, which has only rarely been reported. The clinical course was further complicated by prematurity and very low birth weight. We illustrate the overlapping features of EEC and AEC syndrome and multidisciplinary care needed to address the various clinical challenges.
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| 9. |
- Kanabar, Hrutvik, et al.
(författare)
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PureCake: A Verified Compiler for a Lazy Functional Language
- 2023
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Ingår i: Proceedings of the ACM on Programming Languages. - 2475-1421. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- We present PureCake, a mechanically-verified compiler for PureLang, a lazy, purely functional programming language with monadic effects. PureLang syntax is Haskell-like and indentation-sensitive, and its constraint-based Hindley-Milner type system guarantees safe execution. We derive sound equational reasoning principles over its operational semantics, dramatically simplifying some proofs. We prove end-To-end correctness for the compilation of PureLang down to machine code-The first such result for any lazy language-by targeting CakeML and composing with its verified compiler. Multiple optimisation passes are necessary to handle realistic lazy idioms effectively. We develop PureCake entirely within the HOL4 interactive theorem prover.
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| 10. |
- Pohjola, Johannes Åman, et al.
(författare)
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Kalas: A Verified, End-To-End Compiler for a Choreographic Language
- 2022
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Ingår i: Leibniz International Proceedings in Informatics, LIPIcs. - 1868-8969. ; 237
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Konferensbidrag (refereegranskat)abstract
- Choreographies are an abstraction for globally describing deadlock-free communicating systems. A choreography can be compiled into multiple endpoints preserving the global behavior, providing a path for concrete system implementations. Of course, the soundness of this approach hinges on the correctness of the compilation function. In this paper, we present a verified compiler for Kalas, a choreographic language. Its machine-checked end-to-end proof of correctness ensures all generated endpoints adhere to the system description, preserving the top-level communication guarantees. This work uses the verified CakeML compiler and Hol4 proof assistant, allowing for concrete executable implementations and statements of correctness at the machine code level for multiple architectures.
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