Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailAn evaluation of real-time troposphere estimation based on GNSS Precise Point Positioning
Ding, Wenwu; Teferle, Felix Norman UL; Kazmierski, Kamil et al

in Journal of Geophysical Research: Atmospheres (2017), 122(5), 2779--2790

It is anticipated that the performance of real-time (RT) GNSS meteorology can be further improved by incorporating observations from multiple Global Navigation Satellite System (GNSS), including GPS ... [more ▼]

It is anticipated that the performance of real-time (RT) GNSS meteorology can be further improved by incorporating observations from multiple Global Navigation Satellite System (GNSS), including GPS, GLONASS, Galileo, and BeiDou. In this paper, an operational RT system for extracting zenith troposphere delay (ZTD) using a modified version of the Precise Point Positioning With Integer and Zero-difference Ambiguity Resolution Demonstrator (PPP-WIZARD) was established. GNSS, including GPS, GLONASS, and Galileo, observation streams were processed using RT Precise Point Positioning (PPP) strategy based on RT satellite orbit/clock products from the Centre National d'Etudes Spatiales. An experiment covering 30 days was conducted, in which the observation streams of 20 globally distributed stations were processed. The initialization time and accuracy of the RT troposphere results using single-system and multisystem observations were evaluated. The effect of PPP ambiguity resolution was also evaluated. Results reveal that RT troposphere estimates based on single-system observations can both be applied in weather nowcasting, in which the GPS-only solution is better than the GLONASS-only solution. The performance can also be improved by PPP ambiguity resolution and utilizing GNSS observations. Specifically, we notice that ambiguity resolution is more effective in improving the accuracy of ZTD, whereas the initialization process can be better accelerated by GNSS observations. Combining all techniques, the RT troposphere results with an average accuracy of about 8 mm in ZTD can be achieved after an initialization process of approximately 8.5 min, which demonstrates superior results for applying GNSS observations and ambiguity resolution for RT meteorological applications. [less ▲]

Detailed reference viewed: 168 (8 UL)
Full Text
See detailAn Evaluation of Real-Time Zenith Total Delay Estimates
Ahmed, Furqan UL; Teferle, Felix Norman UL; Bingley, Richard

Poster (2012, December)

Detailed reference viewed: 53 (3 UL)
Full Text
Peer Reviewed
See detailEvaluation of Resource-based App Repackaging Detection in Android
Gadyatskaya, Olga UL; Lezza, A.-L.; Zhauniarovich, Y.

in Proc. of NordSec (2016)

Android app repackaging threatens the health of application markets, as repackaged apps, besides stealing revenue for honest developers, are also a source of malware distribution. Techniques that rely on ... [more ▼]

Android app repackaging threatens the health of application markets, as repackaged apps, besides stealing revenue for honest developers, are also a source of malware distribution. Techniques that rely on visual similarity of Android apps recently emerged as a way to tackle the repackaging detection problem, as code-based detection techniques often fail in terms of effi ciency, and e ffectiveness when obfuscation is applied [19,21]. Among such techniques, the resource-based repackaging detection approach that compares sets of files included in apks has arguably the best performance [20,17,10]. Yet, this approach has not been previously validated on a dataset of repackaged apps. In this paper we report on our evaluation of the approach, and present substantial improvements to it. Our experiments show that the state-of-art tools applying this technique rely on too restrictive thresholds. Indeed, we demonstrate that a very low proportion of identical resource files in two apps is a reliable evidence for repackaging. Furthermore, we have shown that the Overlap similarity score performs better than the Jaccard similarity coe fficient used in previous works. By applying machine learning techniques, we give evidence that considering separately the included resource fi le types signi cantly improves the detection accuracy of the method. Experimenting with a balanced dataset of more than 2700 app pairs, we show that with our enhancements it is possible to achieve the F-measure of 0.9919. [less ▲]

Detailed reference viewed: 117 (6 UL)
Full Text
Peer Reviewed
See detailEvaluation of school tasks in the light of sustainability education: Textbook research in science education in Luxembourgish primary schools
Andersen, Katja Natalie UL

in Environmental Education Research (2017), 24(9), 1301-1319

This article describes a research project that aimed to classify different types of sustainability-related school tasks in terms of two central approaches in primary school education: action-based and ... [more ▼]

This article describes a research project that aimed to classify different types of sustainability-related school tasks in terms of two central approaches in primary school education: action-based and task-based learning. Using a textbook analysis approach, the article clarifies implicit and explicit forms of sustainability education in school tasks in Luxembourgish science textbooks for Grades 1 to 6. The study uses a two-step analysis: first, scanning textbooks on content relating to sustainability; and, second, evaluating the teaching practices associated with this content apparent in the textbooks. Step one identifies the school tasks in which sustainability content is implicitly or explicitly addressed while step two analyzes which forms of action-based and task-based learning occur in these sustainability-related school tasks. Based on the results two claims can be made: first, that there is very little sustainability-related content in Luxembourgish primary science textbooks, and those topics raised mostly relate to sustainability only indirectly; secondly, action-based and task-based learning are undervalued in the context of sustainability-related school tasks; neither of the two was commonly found in school tasks in sustainability education. [less ▲]

Detailed reference viewed: 106 (9 UL)
Full Text
See detailAn Evaluation of the Accuracy of Real-Time Zenith Total Delay Estimates
Ahmed, Furqan UL; Teferle, Felix Norman UL; Bingley, Richard et al

Scientific Conference (2013, April 12)

The continuous evolution of Global Navigation Satellite Systems (GNSS) meteorology has lead to an increased use of associated observations for operational meteorology worldwide. In order to enhance short ... [more ▼]

The continuous evolution of Global Navigation Satellite Systems (GNSS) meteorology has lead to an increased use of associated observations for operational meteorology worldwide. In order to enhance short-term weather forecasts meteorological institutions use modern low-latency Numerical Weather Prediction (NWP) models which assimilate GNSS-derived Zenith Total Delay (ZTD) estimates. For such NWP models a number of GNSS processing strategies allow the provision of these ZTDs with the required accuracy (up to a few millimetres) and latency (hourly). However, meteorological now-casting applications, e.g. for storm tracking, require higher update rates for the ZTDs of 10 or even 5 min, which can be achieved, but only at a loss in accuracy. Using the IGS Real-Time Service orbit and clock products together with an appropriate GNSS software, it is possible to estimate the ZTDs in real-time. Available software packages either use GNSS processing strategies based on differenced or un-differenced observations, such as Precise Point Positioning (PPP). While PPP has clear advantages for efficiently processing data streams from large GNSS networks this strategy is more affected by inaccuracies in the real-time products than when using differenced observations. On the other hand, recent advances in PPP integer ambiguity resolution nowadays provide this strategy with the benefits of ambiguity-fixed solutions. In this study, we present an evaluation of the accuracy of real-time ZTD estimates obtained from several GNSS processing systems through comparison to those obtained from a near real-time and a post-processing system. [less ▲]

Detailed reference viewed: 98 (22 UL)
Full Text
Peer Reviewed
See detailEvaluation of the bridge Champangshiel by using static assessment methods
Scherbaum, Frank; Mahowald, Jean; Waldmann, Danièle UL

in KIT Scientific Publishing, No. 026a, p. 323-329 (2012, July)

Detailed reference viewed: 57 (9 UL)
Full Text
Peer Reviewed
See detailEvaluation of the EGM2008 by Comparison with Global and Local Gravity Solutions from CHAMP
Weigelt, Matthias UL; Sneeuw, N.; Keller, W.

in Mertikas, S. P. (Ed.) Gravity, Geoid and Earth Observation (2010, June)

Detailed reference viewed: 43 (0 UL)
Full Text
Peer Reviewed
See detailEvaluation of the expectations osteoarthritis patients have concerning healthcare, and their implications for practitioners
Baumann, Michèle UL; Euller-Ziegler, L.; Guillemin, F.

in Clinical and Experimental Rheumatology (2007), 25

The expectations of patients with osteoarthritis are essential for health care provision and may be used to improve the patient-doctor relationship. Methods: A total of 96 osteoarthritis patients aged 42 ... [more ▼]

The expectations of patients with osteoarthritis are essential for health care provision and may be used to improve the patient-doctor relationship. Methods: A total of 96 osteoarthritis patients aged 42-89 years (mean = 65; 81% female) were recruited among customers of 10 pharmacies in 10 towns in 10 regions (selected at random from the 22 French regions). Ten focus groups were organized looking at three categories of expectation: 1) Information about and understanding of osteoarthritis; its impact on lifestyle, and its treatment, consequences, and outlook; 2) Communication skills, attitudes of practitioners and communication between health professionals; 3) Support available from doctors, family circle and society. Results: The patient-practitioner relationship begins with a dialogue. Participants suggested that its quality can be improved by: Developing greater trust: patients expect communication skills and expressions of sympathy that practitioners seem ill-prepared to provide. Strengthening involvement: general practitioners in particular should act as mediators and facilitators to improve recognition and understanding of osteoarthritis by employers and public decision-makers. Conclusions: The present study enabled patients to express their expectations. Meeting those expectations could markedly improve the therapeutic process, but the question arises of whether practitioners are ready to agree that there is a need to reconsider and modify the care they provide for their patients. [less ▲]

Detailed reference viewed: 54 (4 UL)
Peer Reviewed
See detailEvaluation of the gamma-synuclein gene in German Parkinson's disease patients.
Krüger, Rejko UL; Schols, L.; Muller, T. et al

in Neuroscience letters (2001), 310(2-3), 191-3

Mutations in the alpha-synuclein gene are responsible for an autosomal-dominantly inherited form of Parkinson's disease (PD) and alpha-synuclein was found to be the major component of Lewy bodies in PD ... [more ▼]

Mutations in the alpha-synuclein gene are responsible for an autosomal-dominantly inherited form of Parkinson's disease (PD) and alpha-synuclein was found to be the major component of Lewy bodies in PD. Because of the high homology to alpha-synuclein and the abundance in neuronal tissues, we investigated the gamma-synuclein gene in PD. We analyzed 262 German PD patients and 179 healthy German controls via two polymorphisms in the gamma-synuclein gene. No significant differences in the allelic or genotypic distributions of the investigated polymorphisms were observed between patients and controls. In addition no evidence for an increased risk of combined genotypes of polymorphisms in the gamma-synuclein and the alpha-synuclein gene was found. Therefore, our results do not support a major role of the gamma-synuclein gene in PD. [less ▲]

Detailed reference viewed: 53 (0 UL)
Peer Reviewed
See detailEvaluation of the information processing and mood effects of a transdermal nicotine patch.
Warburton, D. M.; Mancuso, Giovanna UL

in Psychopharmacology (1998), 135(3), 305-10

The purpose of this study was to determine whether a transdermal nicotine patch will produce the same effects on performance and mood as cigarette smoking. The nicotine patch improved attentional ... [more ▼]

The purpose of this study was to determine whether a transdermal nicotine patch will produce the same effects on performance and mood as cigarette smoking. The nicotine patch improved attentional processing and produced some improvements in memory. It produced the calming effects of smoking and induced feelings of happiness which were increased with smoking. These effects were obtained 6 h after application of the patch, showing that acute tolerance for these behavioural effects had not developed completely, if at all, after exposure to nicotine, although it is still possible that tolerance might occur with longer exposure. [less ▲]

Detailed reference viewed: 76 (0 UL)
Full Text
Peer Reviewed
See detailEvaluation of the interaction between LRRK2 and PARK16 loci in determining risk of Parkinson's disease: analysis of a large multicenter study.
Wang, Lisa; Heckman, Michael G.; Aasly, Jan O. et al

in Neurobiology of aging (2017), 49

A recent study MacLeod et al. has shown that an interaction between variants at the LRRK2 and PARK16 loci influences risk of development of Parkinson's disease (PD). Our study examines the proposed ... [more ▼]

A recent study MacLeod et al. has shown that an interaction between variants at the LRRK2 and PARK16 loci influences risk of development of Parkinson's disease (PD). Our study examines the proposed interaction between LRRK2 and PARK16 variants in modifying PD risk using a large multicenter series of PD patients (7715) and controls (8261) from sites participating in the Genetic Epidemiology of Parkinson's Disease Consortium. Our data does not support a strong direct interaction between LRRK2 and PARK16 variants; however, given the role of retromer and lysosomal pathways in PD, further studies are warranted. [less ▲]

Detailed reference viewed: 98 (3 UL)
See detailThe evaluation of the Luxemburgish Youth Pact as an instrument for cross-sectoral youth policy
Residori, Caroline UL; Reichert, Claudine; Willems, Helmut UL

Conference given outside the academic context (2015)

Detailed reference viewed: 65 (23 UL)
Full Text
Peer Reviewed
See detailEvaluation of the precision of using absolute gravimeters to calibrate superconducting gravimeters
Francis, Olivier UL; van Dam, Tonie UL

in Metrologia (2002), 39(5), 485-488

We present an experiment in which four different FG5 absolute gravimeters (AG) were operated simultaneously alongside a superconducting relative gravimeter (SG). We demonstrate that 0.1 % precision can be ... [more ▼]

We present an experiment in which four different FG5 absolute gravimeters (AG) were operated simultaneously alongside a superconducting relative gravimeter (SG). We demonstrate that 0.1 % precision can be achieved on the calibration factor of the SG by comparison with AG measurements, independently of the FG5 instrument used for the calibration and of the offsets among the FG5 absolute values. This experiment demonstrates the robustness of using any FG5 absolute gravimeter to calibrate any SG. This result is of value to geoscientists analysing data from (a) globally distributed SGs which most probably have been calibrated using different instruments; or (b) any individual SG calibrated with different FG5 absolute gravimeters. [less ▲]

Detailed reference viewed: 98 (4 UL)
Peer Reviewed
See detailEvaluation of the residence time of a moving fuel bed on a forward acting grate.
Peters, Bernhard UL; Dzingys, A.; Hunsinger, H. et al

in Granular Matter (2006)

Detailed reference viewed: 115 (0 UL)
Full Text
See detailEvaluation of the use of new technologies in order to facilitate democracy in Europe
Kies, Raphaël UL; Mendez, Fernando; Schmitter, Philippe et al

Report (2004)

Detailed reference viewed: 85 (1 UL)
Full Text
Peer Reviewed
See detailEvaluation of Tracking Algorithms using Heterogeneous Technologies
Sottile, Francesco; Spirito, Maurizio A.; Closas, Pau et al

in IEEE GLOBECOM, Miami, Florida, 6-10 December, 2010. (2010)

Detailed reference viewed: 46 (3 UL)