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- Conte, Rosaria, et al.
(författare)
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Minding Norms : Mechanisms and dynamics of social order in agent societies
- 2013
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Bok (refereegranskat)abstract
- The book presents theoretical, methodological, and technical advances in the study of norms in societies of autonomous intelligent agents, based on a collaboration among social, computational, and cognitive scientists. By conceptualizing norms as social and cognitive phenomena undergoing a complex dynamics, and thanks to a computational, agent-based approach, contributors address three sets of questions: (a) What are norms, and how may we differentiate them from social conformism on one hand and acquiescence under menace on the other? (b) How do norms emerge and change? An innovative answer is found in the interplay between the mental and social dynamics of norms. (c) How can we characterize the agents from among which norms emerge, why and how people represent norms and abide with or violate them in a non-necessarily deliberative way? Throughout the book, the surprise is that conformity is only the tip of the normative iceberg. Norms emerge in society while “immerging” into the mind. Their mental dynamics, occurring beneath the line of observation, allows all the sets of questions to be answered: a special agent architecture is needed for norm immergence, which in turn allows us to account for how norm-based behavior emerges as a special form of social regularity. After a review of different approaches, the volume presents a dynamic model of norms, the normative agent architecture, a simulation platform, and the artificial experiments testing the view of norms and the architecture proposed against a number of more or less realistic social scenarios.
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- Al-Okshi, Ayman, et al.
(författare)
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Dose optimization for assessment of periodontal structures in cone beam CT examinations
- 2016
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Ingår i: Dento-Maxillo-Facial Radiology. - : British institute of radiology. - 0250-832X .- 1476-542X. ; 46:3
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To investigate the relationship between dose and image quality for a dedicated dental CBCT scanner using different scanning protocols and to set up an optimal imaging protocol for assessment of periodontal structures. METHODS: Radiation dose and image quality measurements were made using 3D Accuitomo 170 (J. Morita, Kyoto, Japan) dental CBCT scanner. The SedentexCT IQ phantom was used to investigate the relationship between contrast-to-noise ratio (CNR) and dose-area product. Subjective image quality assessment was achieved using a small adult skull phantom for the same range of exposure settings. Five independent observers assessed the images for three anatomical landmarks using a three-point visual grade analysis. RESULTS: When correlating the CNR of each scanning protocol to the exposure parameters used to obtain it, CNR decreased as these parameters decreased, especially current-exposure time product. When correlating to subjective image quality, the CNR level remained acceptable when 5 mA and 17.5 s or greater was selected and 80 kV could be used without compromising the CNR. CONCLUSIONS: For a dedicated CBCT unit, changing the rotation angle from 360 degrees to 180 degrees degrades image quality. By altering tube potential and current for the 360 degrees rotation protocol, assessment of periodontal structures can be performed with a smaller dose without substantially affecting visualization.
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- Al-Okshi, Ayman, et al.
(författare)
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Effective dose of cone beam computed tomography (CBCT) of the facial skeleton : a systematic review
- 2015
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Ingår i: British Journal of Radiology. - : British Institute of Radiology. - 0007-1285 .- 1748-880X. ; 88:1045
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Forskningsöversikt (refereegranskat)abstract
- Objective: To estimate effective dose of cone beam CT (CBCT) of the facial skeleton with focus on measurement methods and scanning protocols. Methods: A systematic review, which adhered to the preferred reporting items for systematic reviews (PRISMA) Statement, of the literature up to April 2014 was conducted. Data sources included MEDLINE®, The Cochrane Library and Web of Science. A model was developed to underpin data extraction from 38 included studies. Results: Technical specifications of the CBCT units were insufficiently described. Heterogeneity in measurement methods and scanning protocols between studies made comparisons of effective doses of different CBCT units and scanning protocols difficult. Few studies related doses to image quality. Reported effective dose varied across studies, ranging between 9.7 and 197.0 mSv for field of views (FOVs) with height #5cm, between 3.9 and 674.0 mSv for FOVs of heights 5.1–10.0 cm and between 8.8 and 1073.0 mSv for FOVs .10 cm. There was an inconsistency regarding reported effective dose of studies of the same CBCT unit with the same FOV dimensions. Conclusion: The review reveals a need for studies on radiation dosages related to image quality. Reporting quality of future studies has to be improved to facilitate comparison of effective doses obtained from examinations with different CBCT units and scanning protocols. A model with minimum data set on important parameters based on this observation is proposed. Advances in knowledge: Data important when estimating effective dose were insufficiently reported in most studies. A model with minimum data based on this observation is proposed. Few studies related effective dose to image quality.
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- Eek, Frida, et al.
(författare)
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Attitude and flexibility are the most important work place factors for working parents' mental wellbeing, stress, and work engagement.
- 2013
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Ingår i: Scandinavian Journal of Public Health. - : SAGE Publications. - 1651-1905 .- 1403-4948. ; 41:7, s. 692-705
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Tidskriftsartikel (refereegranskat)abstract
- Aims: The need to combine active employment and parenthood is a reality for many parents today. Knowing more about which work place factors are associated with better or worse health could help employers to form a work environment that provides optimal conditions to maintain or increase health and work engagement in this group. The aim of this study was to explore possible associations between different subjective and objective work factors and benefits, and a range of outcome variables such as stress, symptom report, wellbeing, work-related fatigue, work engagement, and work-family conflict among working mothers and fathers with small children. Methods: Cross-sectional analyses of associations between work place factors categorised into three different dimensions; flexibility, benefits, and attitude and the outcome measures were performed, including questionnaire responses from 1562 working parents. Results: The results showed that work place factors related to flexibility and, especially among women, attitude to parenthood appear to have the strongest effect on working parents' subjective stress and wellbeing, while benefits appear to have less impact. Except regarding factors related to attitudes at the work place, most associations were similar among men and women. Conclusions: Most likely, different factors are better suited or more important for some individuals than others depending on their total work, as well as family situation and also depending on individual factors such as personality and priorities. A positive attitude towards parenthood and a flexible work situation seem, however, beneficial for the general wellbeing and work engagement among working parents.
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- Gurung, Ram B., et al.
(författare)
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Learning Random Forest from Histogram Data Using Split Specific Axis Rotation
- 2018
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Ingår i: International Journal of Machine Learning and Computing. - : EJournal Publishing. - 2010-3700. ; 8:1, s. 74-79
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Tidskriftsartikel (refereegranskat)abstract
- Machine learning algorithms for data containing histogram variables have not been explored to any major extent. In this paper, an adapted version of the random forest algorithm is proposed to handle variables of this type, assuming identical structure of the histograms across observations, i.e., the histograms for a variable all use the same number and width of the bins. The standard approach of representing bins as separate variables, may lead to that the learning algorithm overlooks the underlying dependencies. In contrast, the proposed algorithm handles each histogram as a unit. When performing split evaluation of a histogram variable during tree growth, a sliding window of fixed size is employed by the proposed algorithm to constrain the sets of bins that are considered together. A small number of all possible set of bins are randomly selected and principal component analysis (PCA) is applied locally on all examples in a node. Split evaluation is then performed on each principal component. Results from applying the algorithm to both synthetic and real world data are presented, showing that the proposed algorithm outperforms the standard approach of using random forests together with bins represented as separate variables, with respect to both AUC and accuracy. In addition to introducing the new algorithm, we elaborate on how real world data for predicting NOx sensor failure in heavy duty trucks was prepared, demonstrating that predictive performance can be further improved by adding variables that represent changes of the histograms over time.
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- Huvila, Isto, Professor, 1976-
(författare)
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Revisiting Metagames and Metagaming : Theoretical and Methodological Considerations
- 2023
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Ingår i: Informatio. - : Information Institute of the School of Information and Communication of the Uruguayan State University. - 2301-1378. ; 28:1, s. 336-370
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Tidskriftsartikel (refereegranskat)abstract
- In the context of information behaviour, metagames and metagaming have been used to refer to information work related second-order activities that go beyond the expected ‘game’ of informational undertakings. This paper continues earlier discussion on informational metagames and metagaming by revisiting the two concepts. It inquires further into how to theorise informational metagames and metagaming in terms of and in relation to what they do to information work, and discuss briefly issues relating to how to study informational metagames and metagaming empirically. It is proposed that metagaming can be conceived as a form of resistance, repair and extension of information work. As an often-invisible activity, the empirical study of metagaming is complicated by the difficulties to identify them, make them visible and to demarcate when an activity qualifies as a metagame. Some of the potential benefit of using metagaming as a lens to inquire into information activities are that it can help to shed light on the constituents and underpinnings of both games and their related metagames and to showcase and explicate the complexity and multi-normativity of information work related second-order activities.
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- Karsten, Stanislav L., et al.
(författare)
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Two distinct deletions in the IDS gene and the gene W : a novel type of mutation associated with the Hunter syndrome
- 1997
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Ingår i: Genomics. - : Elsevier BV. - 0888-7543 .- 1089-8646. ; 43:2, s. 123-129
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Tidskriftsartikel (refereegranskat)abstract
- A novel mutation has been identified in a patient with the Hunter syndrome (mucopolysaccharidosis type II), in whom the disorder is associated with two distinct deletions separated by 30 kb. The deletions were characterized by Southern blot and PCR analyses, and the nucleotide sequences at both junctions were determined. The first deletion, corresponding to a loss of 3152 bp of DNA, included exons 5 and 6 of the iduronate-2-sulfatase (IDS) gene. The second deletion was 3603 bp long and included exons 3 and 4 of geneW, which is located in the DXS466 locus telomeric of theIDSgene. Both deletions are the result of nonhomologous (illegitimate) recombination events between short direct repeats at the deletion breakpoints. An interesting finding was the presence of the heptamer sequence 5′-TACTCTA-3′ present at both deletion junctions, suggesting that this motif might be a hot spot for recombination. We propose that the double deletion is the result of homology-associated nonhomologous recombinations caused by the presence of large duplicated regions in Xq27.3–q28.
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