| 1. |
- Al-Dhaqm, Arafat, et al.
(författare)
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Face validation of database forensic investigation metamodel
- 2021
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Ingår i: Infrastructures. - Basel : MDPI. - 2412-3811. ; 6:2, s. 1-19
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Tidskriftsartikel (refereegranskat)abstract
- Using a face validity approach, this paper provides a validation of the Database Forensic Investigation Metamodel (DBFIM). The DBFIM was developed to solve interoperability, heterogeneity, complexity, and ambiguity in the database forensic investigation (DBFI) field, where several models were identified, collected, and reviewed to develop DBFIM. However, the developed DBFIM lacked the face validity-based approach that could ensure DBFIM’s applicability in the DBFI field. The completeness, usefulness, and logic of the developed DBFIM needed to be validated by experts. Therefore, the objective of this paper is to perform the validation of the developed DBFIM using the qualitative face validity approach. The face validity method is a common way of validating metamodels through subject expert inquiry on the domain application of the metamodel to assess whether the metamodel is reasonable and compatible based on the outcomes. For this purpose, six experts were nominated and selected to validate the developed DBFIM. From the expert review, the developed DBFIM was found to be complete, coherent, logical, scalable, interoperable, and useful for the DBFI field.
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| 2. |
- Alawadi, Sadi, et al.
(författare)
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A Federated Interactive Learning IoT-Based Health Monitoring Platform
- 2021
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Ingår i: New Trends in Database and Information Systems. - Cham : Springer. ; , s. 235-246, s. 235-246
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Konferensbidrag (refereegranskat)abstract
- Remote health monitoring is a trend for better health management which necessitates the need for secure monitoring and privacy-preservation of patient data. Moreover, accurate and continuous monitoring of personal health status may require expert validation in an active learning strategy. As a result, this paper proposes a Federated Interactive Learning IoT-based Health Monitoring Platform (FIL-IoT-HMP) which incorporates multi-expert feedback as ‘Human-in-the-loop’ in an active learning strategy in order to improve the clients’ Machine Learning (ML) models. The authors have proposed an architecture and conducted an experiment as a proof of concept. Federated learning approach has been preferred in this context given that it strengthens privacy by allowing the global model to be trained while sensitive data is retained at the local edge nodes. Also, each model’s accuracy is improved while privacy and security of data has been upheld.
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| 3. |
- Alkebro, Jesper, et al.
(författare)
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Modeling high-energy ball milling in the alumina-yttria system
- 2002
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Ingår i: Journal of Solid State Chemistry. - : Elsevier BV. - 0022-4596 .- 1095-726X. ; 164:1, s. 88-97
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Tidskriftsartikel (refereegranskat)abstract
- Experimental results from high-energy ball milling of alumina-yttria powder mixtures have been analyzed with models collected from the literature. Depending on the milling conditions, either there is formation of an intermediate phase in the alumina-yttria system (yttrium aluminum perovskite, YAP), or the sample becomes mostly amorphous. Variations due to milling tool material can be accounted for by local models based on the Hertzian theory of elastic bodies, but the effects of changing mills are poorly accounted for by published models. Therefore, the concept of an impact frequency distribution over the energy spectrum is introduced as a tool for studying the characteristics of the mills. The pressure on the powder trapped between two colliding bodies has been found to be the factor deciding the outcome of the process. The threshold behavior of the system yields an amorphous structure for low pressures, and formation of YAP when impact pressures exceed the threshold value.
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| 4. |
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| 5. |
- Axelsson, Malin, et al.
(författare)
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Differences in diagnostic patterns of obstructive airway disease between areas and sex in Sweden and Finland : The Nordic EpiLung Study
- 2021
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Ingår i: Journal of Asthma. - : Taylor & Francis. - 0277-0903 .- 1532-4303. ; 58:9, s. 1196-1207
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate the current prevalence of physician-diagnosed obstructive airway diseases by respiratory symptoms and by sex in Sweden and Finland. Method: In 2016, a postal questionnaire was answered by 34,072 randomly selected adults in four study areas: Västra Götaland and Norrbotten in Sweden, and Seinäjoki-Vaasa and Helsinki in Finland. Results: The prevalence of asthma symptoms was higher in Norrbotten (13.2%), Seinäjoki-Vaasa (14.8%) and Helsinki (14.4%) than in Västra Götaland (10.7%), and physician-diagnosed asthma was highest in Norrbotten (13.0%) and least in Västra Götaland (10.1%). Chronic productive cough was most common in the Finnish areas (7.7-8.2 % versus 6.3-6.7 %) while the prevalence of physician-diagnosed chronic bronchitis (CB) or chronic obstructive pulmonary disease (COPD) varied between 1.7-2.7% in the four areas. Among individuals with respiratory symptoms, the prevalence of asthma was most common in Norrbotten, while a diagnosis of COPD or CB was most common in Västra Götaland and Seinäjoki-Vaasa. More women than men with respiratory symptoms reported a diagnosis of asthma in Sweden and Seinäjoki-Vaasa but there were no sex differences in Helsinki. In Sweden, more women than men with symptoms of cough or phlegm reported a diagnosis of CB or COPD, while in Finland the opposite was found. Conclusion: The prevalence of respiratory symptoms and corresponding diagnoses varied between and within the countries. The proportion reporting a diagnosis of obstructive airway disease among individuals with respiratory symptoms varied, indicating differences in diagnostic patterns both between areas and by sex.
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| 6. |
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| 7. |
- Azadian, Saied
(författare)
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Aspects of precipitation in alloy Inconel 718
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A study was made of the microstructure of the Ni-base alloy Inconel 718 with emphasis on the precipitation and stability of intermetallic phases as affected by heat treatments. In addition the effect of the precipitation on selected mechanical properties namely hardness, creep notch sensitivity and hot ductlity were investigated. The materials studied were a spray-formed version and three wrought versions of the alloy. The spray-formed version of the alloy was of interest since it exhibited a superior compositional homogeneity to more conventional forms of the alloy. To characterise the precipitation kinetics and to determine the associated hardening, a series of isothermal ageing treatments were carried out on both spray-formed and ring rolled material at selected temperatures between 600°C and 1025°C for up to 100h. The results were presented in the form of TTH diagrams for the two alloys. The heat treated specimens were then studied using optical microscopy, scanning electron microscopy and transmission electron microscopy. Where possible these were supplemented with quantitative metallographic measurements of volume fraction and precipitates size.The three main intermetallic precipitation phases in IN 718 are (i) gamma’ having a composition Ni3(Al,Ti), a cubic crystal structure and cubic or spherical particle shape (ii) gamma” having a composition Ni3Nb, a bct crystal structure and a lens-like disc shape (iii)delta having composition Ni3Nb, an orthorhombic crystal structure and forming as grain boundary particles and films as well as thin plates extending long distances into the grains. In thermomechanically processed material the delta-phase can also occur as shorter platelets and particles resulting from fragmentation of the original plates. In this work the rates of precipitation and the temperature ranges of their existence were determined qualitatively. Moreover the coarsening of the ganmma" precipitates was determined quantitatively. The kinetics of precipitation and dimensional coarsening of the delta-phase were also established quantitatively. Similarly, the dissolution kinetics of the delta-phase were measured in the spray-formed and three wrought versions of the alloy leading to a determination of the effect of Nb-content on the delta solvus temperature. After a standard heat treatment, the spray-formed IN 718 was found to be creep notch sensitive according to an SAE-AMS standard rupture test. It was found that notch ductility could be restored to the alloy by inserting a delta-phase precipitation treatment at 875°C-900°C prior to the standard heat treatment. This could be attributed to the formation of a more favourable delta-phase morphology than that formed during the solution treatment at 954°C in the standard heat treatment cycle. A study was made of high temperature tensile properties of a wrought version of IN 718 in particular in relation to the problem of hot cracking in repair welding. Measurements were made of the strength loss temperature on heating and the strength and ductility return temperatures on cooling. These properties provide an indication of the sensitivity of the alloy to hot cracking due to liquation. The tests were made on the alloy after various heat treatments designed to produce microstructures with two different grain sizes with and without delta-phase precipitation. Hot tensile tests were also performed on the in-situ solidified alloy in order to describe the weld metal ductility and properties. The grain size and the presence of large fractions of delta-phase precipitated at 900°C had only small effects on the strength loss temperature and brittle-ductile transition of the alloy. On the other hand, a small fraction of delta-phase precipitated in the grain boundaries at 960°C reduced the brittle-ductile transition temperature significantly. It is proposed that the reduction was associated with interaction between the grain boundary delta-phase and grain boundary boron segregation that was observed in all the heat treated materials.
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| 8. |
- Azadian, Saied, et al.
(författare)
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Delta Phase Precipitation in Inconel 718
- 2004
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Ingår i: Materials Characterization. - : Elsevier. - 1044-5803 .- 1873-4189. ; :52, s. 7-16
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Tidskriftsartikel (refereegranskat)abstract
- The precipitation and dissolution kinetics of the δ-phase were studied in three wrought versions and one spray-formed (SF) version of the nickel alloy, Inconel 718. The precipitation in the spray-formed version and one wrought version was followed during isothermal ageing for up to 100 h between 700 and 1000 °C. The δ-phase precipitates in the form of nonuniformly distributed thin platelets and an alternative method of measuring volume fraction of this precipitate morphology is proposed. At and above 800 °C, the precipitation was measured quantitatively in terms of the volume fraction and platelet thickness distribution. The maximum rate of precipitation occurred at approximately 900 °C. The solvus temperature lay between 1005 and 1015 °C for Nb contents of 5.06 and 5.41 wt.%, respectively. A study was made of the dissolution of the δ-phase in all four alloys using isochronal treatments and this confirmed the above solvus temperature range. The effect of δ-phase and its dissolution on the grain growth of the alloys was also determined.
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| 9. |
- Backman, Helena, et al.
(författare)
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Decreased COPD prevalence in Sweden after decades of decrease in smoking
- 2020
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Ingår i: Respiratory Research. - : Springer Nature. - 1465-9921 .- 1465-993X. ; 21
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundCOPD has increased in prevalence worldwide over several decades until the first decade after the millennium shift. Evidence from a few recent population studies indicate that the prevalence may be levelling or even decreasing in some areas in Europe. Since the 1970s, a substantial and ongoing decrease in smoking prevalence has been observed in several European countries including Sweden. The aim of the current study was to estimate the prevalence, characteristics and risk factors for COPD in the Swedish general population. A further aim was to estimate the prevalence trend of COPD in Northern Sweden from 1994 to 2009.MethodsTwo large random population samples were invited to spirometry with bronchodilator testing and structured interviews in 2009–2012, one in south-western and one in northern Sweden, n = 1839 participants in total. The results from northern Sweden were compared to a study performed 15 years earlier in the same area and age-span. The diagnosis of COPD required both chronic airway obstruction (CAO) and the presence of respiratory symptoms, in line with the GOLD documents since 2017. CAO was defined as post-bronchodilator FEV1/FVC < 0.70, with sensitivity analyses based on the FEV1/FVC < lower limit of normal (LLN) criterion.ResultsBased on the fixed ratio definition, the prevalence of COPD was 7.0% (men 8.3%; women 5.8%) in 2009–2012. The prevalence of moderate to severe (GOLD ≥ 2) COPD was 3.5%. The LLN based results were about 30% lower. Smoking, occupational exposures, and older age were risk factors for COPD, whereof smoking was the most dominating risk factor. In northern Sweden the prevalence of COPD, particularly moderate to severe COPD, decreased significantly from 1994 to 2009, and the decrease followed a decrease in smoking.ConclusionsThe prevalence of COPD has decreased in Sweden, and the prevalence of moderate to severe COPD was particularly low. The decrease follows a major decrease in smoking prevalence over several decades, but smoking remained the dominating risk factor for COPD.
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| 10. |
- Barai, Manas, et al.
(författare)
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Physicochemical Studies on Amino Acid Based Metallosurfactants in Combination with Phospholipid
- 2024
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Ingår i: Chemistry - An Asian Journal. - : John Wiley & Sons. - 1861-4728 .- 1861-471X.
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Tidskriftsartikel (refereegranskat)abstract
- Dicarboxylate metallosurfactants (AASM), synthesized by mixing N-dodecyl aminomalonate, -aspartate and -glutamate with CaCl2, MnCl2 and CdCl2, were characterized by XRD, FTIR, and NMR spectroscopy. Layered structures, formed by metallosurfactants, were evidenced from differential scanning calorimetry and thermogravimetric analyses. Solvent-spread monolayer of AASM in combination with soyphosphatidylcholine (SPC) and cholesterol (CHOL) were studied using Langmuir surface balance. With increasing mole fraction of AASM mean molecular area increased and passed through maxima at ~60 mol% of AASMs, indicating molecular packing reorganization. Systems with 20 and 60 mol% AASM exhibited positive deviations from ideal behavior signifying repulsive interaction between the AASM and SPC, while synergistic interactions were established from the negative deviation at other combinations. Dynamic surface elasticity increased with increasing surface pressure signifying formation of rigid monolayer. Transition of monolayer from gaseous to liquid expanded to liquid condensed state was established by Brewster angle microscopic studies. Stability of the hybrid vesicles, formed by AASM+SPC+CHOL, was established by monitoring their size, zeta potential and polydispersity index values over 100 days. Size and spherical morphology of hybrid vesicles were confirmed by transmission electron microscopic studies. Biocompatibility of the hybrid vesicles were established by cytotoxicity studies revealing their possible applications in drug delivery and imaging.
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