Evaluation of a volunteered geographical information trust measure in the case of OpenStreetMap

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.The presence of Volunteered Geographical Information is attracting research because its high availability and diversity make it an interesting source of information. For many organisations it is important that quality of geographical information is of a certain level. Recent developments in studies related to VGI direct towards the estimation of its quality through the notion of trust as a proxy. For this thesis is investigated which factors have an important influence on trust and a simple approach was used to come up with an indication of trust levels for geographical features. The indicators were selected based on a literature review and on a dataset extracted from the open mapping project OpenStreetMap. Numbers of users, versions and confirmations were counted or calculated and involved as positive indicators, while numbers of various corrections were treated as indicators having a negative influence on the development of trust in information. Analysis of the dataset and thinking about how to incorporate what in the trust measure showed for example how ideas about time decay could be different. Importance of tags was determined based on a method adopted from documentation studies and applied on the dataset. It allowed for generating lists of tags to be described when publishing information about particular features. This was of importance for assessing information completeness in measuring the quality of the data. The results of the trust measure have been compared to those if the quality measure and an evaluation of this comparison shows significant signs of support for the hypothesis that VGI data quality can be estimated based on a trust model that incorporates data provenance. On the other hand there is also a significant number of features of which both measures show opposite indications of quality. Various single assumptions, simplifications and the relatively small size of the dataset restricted the possibilities for obtaining more accurate results. Confirmation or denial of the ideas that resulted from this research can be made by enlarging the dataset and experimenting with different methods. Automating all the data processing would be necessary

Relationship between formaldehyde and quaternium-15 contact allergy. Influence of strength of patch test reactions

Objectives: To test our hypothesis that patients with stronger patch test reactions to formaldehyde are more likely to react to quaternium-15, attesting to the aetiological role for formaldehyde in such co-reactivity. Methods: Retrospective analysis of all patients patch tested with formaldehyde and quaternium-15 in the European baseline series between 1994 and 2009 (TRUE test (R)). Results: In a group of 86 patients allergic to formaldehyde, 73% co-reacted to quaternium-15; in the subgroup of 70 women, the percentage was 83. In both groups, more reactions were observed to quaternium-15 in the patients with a ++ reaction compared to the patients with a + reaction to formaldehyde. Conversely, stronger reactions to quaternium-15 were significantly more often associated with formaldehyde sensitivity in a group of 107 patients reacting to quaternium-15 and a subgroup of 88 women. In men, such effects were not observed and only 5 of 16 (31%) men allergic to formaldehyde also reacted to quaternium-15. Conclusions: In women, but not in men, stronger reactions to formaldehyde lead to more positive quaternium-15 patch tests

The effect of therapist characteristics on the use and outcome of systematic client feedback in outpatient mental healthcare

ObjectiveTherapist characteristics are known to affect treatment outcome in general and could also influence the use of systematic client feedback (SCF). The current study explores the effect of feedback orientation, regulatory focus, self-efficacy, attitude towards feedback resources and perceived feedback validity on the use and outcome of SCF in outpatient mental healthcare.MethodThe data of therapists (n = 12) and patients (n = 504) of two outpatient centres offering brief psychological treatment were analysed when SCF, based on the Partners for Change Outcome Management System (PCOMS), was added to treatment as usual. The data of therapists were obtained through a therapist questionnaire composed of relevant characteristics from feedback studies in social and organizational psychology. The effect on the use of SCF was analysed using logistic regression; whereas, the effect on outcome was assessed using a two-level multilevel analysis. Regular use of SCF and the Outcome Questionnaire (OQ-45) were used as outcome variables. DSM-classification, sex and age of each patient were included as covariates.ResultsHigh perceived feedback validity significantly increased the use of SCF. No significant therapist characteristics effects were found on outcome, but high promotion focus was associated with treating more complex patients.ConclusionsThe perceived feedback validity of SCF is likely to have an influence on its use and is probably affected by the changes in the organizational climate

Shear Viscosities from the Chapman-Enskog and the Relaxation Time Approaches

The interpretation of the measured elliptic and higher order collective flows in heavy-ion collisions in terms of viscous hydrodynamics depends sensitively on the ratio of shear viscosity to entropy density. Here we perform a quantitative comparison between the results of shear viscosities from the Chapman-Enskog and relaxation time methods for selected test cases with specified elastic differential cross sections: (i) The non-relativistic, relativistic and ultra-relativistic hard sphere gas with angle and energy independent differential cross section (ii) The Maxwell gas, (iii) chiral pions and (iv) massive pions for which the differential elastic cross section is taken from experiments. Our quantitative results reveal that (i) the extent of agreement (or disagreement) depends sensitively on the energy dependence of the differential cross sections employed, and (ii) stress the need to perform quantum molecular dynamical (URQMD) simulations that employ Green-Kubo techniques with similar cross sections to validate the codes employed and to test the accuracy of other methods.Comment: To be submitted to PR