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See detailEvaluation of a regional real-time precise positioning system based on GPS/BeiDou observations in Australia
Ding, Wenwu UL; Tan, Bingfeng; Chen, Yongchang et al

in Advances in Space Research (2018)

The performance of real-time (RT) precise positioning can be improved by utilizing observations from multiple Global Navigation Satellite Systems (GNSS) instead of one particular system. Since the end of ... [more ▼]

The performance of real-time (RT) precise positioning can be improved by utilizing observations from multiple Global Navigation Satellite Systems (GNSS) instead of one particular system. Since the end of 2012, BeiDou, independently established by China, began to provide operational services for users in the Asia-Pacific regions. In this study, an regional RT precise positioning system in Australia is developed to evaluate the performance of GPS/BeiDou observations in providing high precision positioning services for users. Fixing three hourly updated satellite orbits, RT correction messages are generated and broadcasted by processing RT observation/navigation data streams from AUSCORS at the server side. At the user side, RT PPP is realized by processing RT data streams and the RT correction messages received. RT clock offsets, for which the accuracy reached 0.07 and 0.25 ns for GPS and BeiDou, respectively, can be determined. Based on these corrections, an accuracy of 12.2, 30.0 and 45.6 cm in the North, East and Up directions was achieved for the BeiDou-only solution after 30 minutes while the GPS-only solution reached 5.1, 15.3 and 15.5 cm for the same components at the same time. A further improvement of 43.7, 36.9 and 45.0 percent in the three directions, respectively, was achieved for the combined GPS/BeiDou solution. After the initialization process, the North, East and Up positioning accuracies were 5.2, 8.1 and 17.8 cm, respectively, for the BeiDou-only solution, while 1.5, 3.0, and 4.7 cm for the GPS-only solution. However, we only noticed a 20.9% improvement in the East direction was obtained for the GPS/BeiDou solution, while no improvements in the other directions were detected. It is expected that such improvements may become bigger with the increasing accuracy of the BeiDou-only solution. [less ▲]

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See detailEvaluation of an anatomically augmented Statistical Shape Model of the scapula: Clinical validation and reliability of landmark selection. Submited to
Borotikar, Bhushan; Ghorbel, Enjie UL; Lempereur, Mathieu et al

in Computer Methods in Biomechanics and Biomedical Engineering. Imaging and Visualization (2015)

Detailed reference viewed: 50 (1 UL)
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See detailEvaluation of an antagonistic model of self-controlled skill learning
Bund, Andreas UL; Ferwagner, Dirk

Poster (2006, July)

Detailed reference viewed: 24 (0 UL)
Peer Reviewed
See detailThe evaluation of an educational system toward its monitoring and piloting
Houssemand, Claude UL; Wanlin, P

Poster (2007, September)

Detailed reference viewed: 25 (1 UL)
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See detailEvaluation of basic motor competencies in primary school children: Development of a test instrument
Scheuer, Claude; Bund, Andreas UL; Herrmann, Christian

in Revista Espanola de Educación Física y Deporte (2015, July), 410 (Supl.)(3), 486

Detailed reference viewed: 63 (4 UL)
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See detailEvaluation of Cell Line Suitability for Disease Specific Perturbation Experiments.
Biryukov, Maria UL; Antony, Paul UL; Krishna, Abhimanyu UL et al

in Lausen, Berthold; Krolak-Schwerdt, Sabine; Böhmer, Matthias (Eds.) Data Science, Learning by Latent Structures, and Knowledge Discovery (2015, February 20)

Cell lines are widely used in translational biomedical research to study the genetic basis of diseases. A major approach for experimental disease modeling are genetic perturbation experiments that aim to ... [more ▼]

Cell lines are widely used in translational biomedical research to study the genetic basis of diseases. A major approach for experimental disease modeling are genetic perturbation experiments that aim to trigger selected cellular disease states. In this type of experiments it is crucial to ensure that the targeted disease- related genes and pathways are intact in the used cell line. In this work we are developing a framework which integrates genetic sequence information and disease- specific network analysis for evaluating disease-specific cell line suitability. [less ▲]

Detailed reference viewed: 198 (23 UL)
See detailEvaluation of cognitive ability in heterogeneous student populations: Development of the Test of Cognitive Potential
Muller, Claire UL

Doctoral thesis (2016)

Evaluation of cognitive potential of individuals with diverse backgrounds often presents a challenge. Individuals’ imperfect mastery of the language of instruction in particular presents a major threat to ... [more ▼]

Evaluation of cognitive potential of individuals with diverse backgrounds often presents a challenge. Individuals’ imperfect mastery of the language of instruction in particular presents a major threat to validity of results and prohibits comparison to performance with better language skills. Eliminating language from test instruction may be a solution to this problem. The present thesis presents the development and validation of the innovative Test of Cognitive Potential (TCP), a language-free, tablet-based group-assessment tool designed to measure fluid intelligence within children in grade 4 (regular age between 9 and 10). Using dynamic visual instruction videos, task requirements are presented visually, without adding any verbal clarification. In order to sample a wide array of cognitive processes on different contents (domain-general, quantitative and semantic-syntactic reasoning as well as visual processing), the TCP includes a variety of subtests. Using confirmatory factor analysis, the overall structure of the test is evaluated within student samples from Luxembourg, Germany and Brazil. In a 2x2 design, measurement invariance of a latent TCP g-factor is further shown to largely hold across combinations of verbal vs. visual dynamic instruction and tablet-based vs. paper & pencil assessment. For the target TCP version (tablet and dynamic visual instruction), only one subtest is found to present increased residual variance and thus needs revision. Overall, a strong association of the TCP with criterion measures (educational achievement and a well-established test of cognitive ability) is found across samples. Measurement of a latent TCP factor could further be shown to be invariant across students with differential opportunity to learn. No strong evidence of biased measurement is found for students with different language backgrounds and socio-economic status. The Test of Cognitive Potential proofs to be a valid and reliable tool for the measurement of general cognitive ability. It will be particularly useful for the evaluation of children with limited understanding of the local language. Avoiding language bias, the TCP may contribute to the reduction of inequalities in educational opportunities that are produced by structural characteristics of many school systems. [less ▲]

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See detailEvaluation of detemir in diabetic cats managed with a protocol for intensive blood glucose control
Roomp, Kirsten UL; Rand, Jacquie

in Journal of Feline Medicine and Surgery (2012), 14(8), 566-572

The aim of this study was to report outcomes using detemir and a protocol aimed at intensive blood glucose control with home monitoring in diabetic cats, and to compare the results with a previous study ... [more ▼]

The aim of this study was to report outcomes using detemir and a protocol aimed at intensive blood glucose control with home monitoring in diabetic cats, and to compare the results with a previous study using the same protocol with glargine. Eighteen cats diagnosed with diabetes and previously treated with other insulins were included in the study. Data was provided by owners who joined the online German Diabetes-Katzen Forum. The overall remission rate was 67%. For cats that began the protocol before or after 6 months of diagnosis, remission rates were 81% and 42%, respectively (P = 0.14). No significant differences were identified between the outcomes for the glargine and detemir studies, with the exception of three possibly interrelated factors: a slightly older median age of the detemir cohort at diabetes diagnosis, a higher rate of chronic renal disease in the detemir cohort and lower maximal dose for insulin detemir. [less ▲]

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See detailEvaluation of Different Optimization Techniques in the Design of Ad Hoc Injection Networks
Dorronsoro, Bernabé UL; Danoy, Grégoire UL; Bouvry, Pascal UL et al

in special session on Parallel and Grid Computing for Optimization as part of The 2008 International Conference High Performance Computing & Simulation (HPCS008) and in conjunction with The 22nd European Conference on Modeling and Simulation (ECMS 2008). (2008)

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See detailEvaluation of End-To-End Learning for Autonomous Driving: The Good, the Bad and the Ugly
Varisteas, Georgios UL; Frank, Raphaël UL; Sajadi Alamdari, Seyed Amin UL et al

in 2nd International Conference on Intelligent Autonomous Systems, Singapore, Feb. 28 to Mar. 2, 2019 (2019, March 01)

Detailed reference viewed: 270 (48 UL)
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See detailEvaluation of ERA-Interim for tropospheric delay and water vapour estimation in different climate zones using ground-based GNSS observations
Ahmed, Furqan; Hunegnaw, Addisu UL; Teferle, Felix Norman UL et al

Poster (2017, April 27)

Tropospheric delay and integrated water vapour (IWV) derived from climate reanalysis models, such as that of the European Centre for Medium-range Weather Forecasts (ECMWF) namely the ECMWF ReAnalysis ... [more ▼]

Tropospheric delay and integrated water vapour (IWV) derived from climate reanalysis models, such as that of the European Centre for Medium-range Weather Forecasts (ECMWF) namely the ECMWF ReAnalysis-Interim (ERA-Interim), are widely used in many geodetic and atmospheric applications. Therefore, it is of interest to assess the quality of these reanalysis products using available observations. Observations from Global Navigation Satellite Systems (GNSS) are, as of now, available for a period of over 2 decades and their global availability make it possible to validate the zenith total delay (ZTD) and IWV obtained from climate reanalysis models in different geographical and climatic regions. In this study, a 5-year long homogeneously reprocessed GNSS data set based on double differenced positioning strategy and containing over 400 globally distributed ground-based GNSS stations has been used as a reference to validate the ZTD estimates obtained from the ERA-Interim climate reanalysis model in 25 different climate zones. It has been studied how the difference between the ERA-Interim ZTD and the GNSS-derived ZTD varies with respect to the different climate zones as well as the topographic variations in a particular climate zone. Periodicity in the ZTD residuals in different climate zones has been analyzed. Furthermore, the variation of the ZTD differences with respect to latitude has been presented. Finally, for one GNSS station in each of the 25 climate zones, IWV derived from ERA-Interim has been compared to the IWV derived using GNSS observations. [less ▲]

Detailed reference viewed: 181 (11 UL)
See detailEvaluation of global ocean tide models based on tidal gravity observations in China
Tan, H.; Francis, Olivier UL; Shen, C. et al

Scientific Conference (2019)

Solid Earth is affected by tidal cycles triggered by the gravity attraction of the celestial bodies. However, about 70% the Earth is covered with seawater which is also affected by the tidal forces. In ... [more ▼]

Solid Earth is affected by tidal cycles triggered by the gravity attraction of the celestial bodies. However, about 70% the Earth is covered with seawater which is also affected by the tidal forces. In the coastal areas, the ocean tidal loading (OTL) can reach up to 10% of the earth tide, 90% for tilt, and 25% for strain (Farrell, 1972). Since 2007, a high-precision continuous gravity observation network in China has been established with 78 stations. The long-term high-precision tidal data of the network can be used to validate, verifying and even improve the ocean tidal model (OTM). In this paper, tidal parameters of each station were extracted using the harmonic analysis method after a careful editing of the data. 8 OTMs were used for calculating the OTL. The results show that the Root-Mean-Square of the tidal residuals (M0) vary between 0.078-1.77 μgal, and the average errors as function of the distance from the sea for near(0-60km), middle(60-1000km) and far(>1000km) stations are 0.76, 0.30 and 0.21 μgal. The total final gravity residuals (Tx) of the 8 major constituents (M2, S2, N2, K2, K1, O1, P1, Q1) for the best OTM has amplitude ranging from 0.14 to 3.45 μgal. The average efficiency for O1 is 77.0%, while 73.1%, 59.6% and 62.6% for K1, M2 and Tx. FES2014b provides the best corrections for O1 at 12 stations, while SCHW provides the best for K1 ,M2 and Tx at 12 , 8 and 9 stations. For the 11 costal stations, there is not an obvious best OTM. The models of DTU10, EOT11a and TPXO8 look a litter better than FES2014b, HAMTIDE and SCHW. For the 17 middle distance stations, SCHW is the best OTM obviously. For the 7 far distance stations, FES2014b and SCHW model are the best models. But the correction efficiency is worse than the near and middle stations'. The outcome is mixed: none of the recent OTMs performs the best for all tidal waves at all stations. Surprisingly, the Schwiderski's model although is 40 years old with a coarse resolution of 1° x 1° is performing relative well with respect to the more recent OTM. Similar results are obtained in Southeast Asia (Francis and van Dam, 2014). It could be due to systematic errors in the surroundings seas affecting all the ocean tides models. It's difficult to detect, but invert the gravity attraction and loading effect to map the ocean tides in the vicinity of China would be one way. [less ▲]

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See detailEvaluation of GNSS as a Tool for Monitoring Tropospheric Water Vapour
Ahmed, Furqan UL

Bachelor/master dissertation (2010)

Global Navigation Satellite Systems have the potential to become a significant tool in climate research ... [more ▼]

Global Navigation Satellite Systems have the potential to become a significant tool in climate research due to the fact that GNSS data can be processed in order to estimate the propagation delay experienced by the signal in atmosphere. If the ground pressure and temperature is known, the signal propagation path delay can be related to the amount of water vapour in the atmosphere. This thesis project focuses on the evaluation of GNSS as a tool for atmospheric water vapour estimation. In the first part of the project, various GNSS data processing software packages were compared by processing the same set of data and performing a statistical comparison of the estimates of zenith total delay obtained by each package. The software packages compared are GIPSY‐OASIS, Bernese GNSS Processing Software, GAMIT and magicGNSS. Also different strategies and methods, such as double‐differencing and precise point positioning,  are  investigated.  The  output from the  packages  is  validated  using  delay measurements obtained from ECMWF and RCA numerical models. It was observed that the output from climate models agrees with that from the software packages and the output from various software packages have a similarity between each other within 3 millimeters. In the second part of the project, simulations of new GNSS are carried out using in‐house software developed at Chalmers and SP Technical Research Institute of Sweden in order to investigate new methods and possible future improvements. The effect of local errors on atmospheric delay estimates from GPS, GLONASS and Galileo was studied through simulations. A hypothetical system formed by combination of the constellations of GPS, GLONASS and Galileo was also simulated and it was found to be least susceptible to local errors. Simulations were performed by varying some Keplerian orbital elements for Galileo system and it was observed that an orbit inclination between 60 degree and 65 degree would have been optimum for Galileo system. [less ▲]

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See detailEvaluation of heat transfer on a backward acting grate
Peters, Bernhard UL; Džiugys

in MECHANIKA (2014), 20

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See detailAn evaluation of high-throughput approaches to QTL mapping in Saccharomyces cerevisiae
Wilkening, Stefan; Lin, Gen; Fritsch, Emilie S. et al

in Genetics (2014), 196(3), 853-65

Dissecting the molecular basis of quantitative traits is a significant challenge and is essential for understanding complex diseases. Even in model organisms, precisely determining causative genes and ... [more ▼]

Dissecting the molecular basis of quantitative traits is a significant challenge and is essential for understanding complex diseases. Even in model organisms, precisely determining causative genes and their interactions has remained elusive, due in part to difficulty in narrowing intervals to single genes and in detecting epistasis or linked quantitative trait loci. These difficulties are exacerbated by limitations in experimental design, such as low numbers of analyzed individuals or of polymorphisms between parental genomes. We address these challenges by applying three independent high-throughput approaches for QTL mapping to map the genetic variants underlying 11 phenotypes in two genetically distant Saccharomyces cerevisiae strains, namely (1) individual analysis of >700 meiotic segregants, (2) bulk segregant analysis, and (3) reciprocal hemizygosity scanning, a new genome-wide method that we developed. We reveal differences in the performance of each approach and, by combining them, identify eight polymorphic genes that affect eight different phenotypes: colony shape, flocculation, growth on two nonfermentable carbon sources, and resistance to two drugs, salt, and high temperature. Our results demonstrate the power of individual segregant analysis to dissect QTL and address the underestimated contribution of interactions between variants. We also reveal confounding factors like mutations and aneuploidy in pooled approaches, providing valuable lessons for future designs of complex trait mapping studies. [less ▲]

Detailed reference viewed: 86 (1 UL)
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See detailEvaluation of intensive blood glucose control using glargine in diabetic cats
Roomp, Kirsten UL; Rand, J.S.

in Journal of Veterinary Internal Medicine (2008), 22(3), 790

Detailed reference viewed: 25 (1 UL)
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See detailEvaluation of intervention strategies for a road link in the Netherlands
Adey, Bryan Tyrone; Lethanh, Nam; Hartmann, Andreas et al

in Built Environment Project and Asset Management (2014), 4(2), 180-198

Purpose – The purpose of this paper is to investigate the use of the impact hierarchy and the optimization model to determine the optimal intervention strategy for a road link composed of multiple objects ... [more ▼]

Purpose – The purpose of this paper is to investigate the use of the impact hierarchy and the optimization model to determine the optimal intervention strategy for a road link composed of multiple objects. The paper focusses on the results of a case study of intervention project on A20 road link in Rotterdam, the Netherlands. Design/methodology/approach – The study was a case study research. It describes briefly the impact hierarchy and its link to the optimization model, and then focussed on analyzing the results obtained from running the model. In order to understand the influence of various factors affecting the results of optimization, sensitivity analysis was performed. Findings – The proposed hierarchy is suitable to be used to support the determination of optimal intervention strategies (OISs) for public road. From the case study, it was also realized that optimal intervention strategy can be changed due to not only intervention costs incurred by the owner, but also due to the setup of traffic configuration during the execution of interventions since the impacts incurred to users, directly affected public, and indirectly affected public are significantly different from one traffic configuration to the others. The optimal intervention strategy also depends greatly on the factors of deterioration during the operation of the infrastructure objects. Research limitations/implications – In the impact hierarchy, some impact factors are difficult to be quantified, e.g., the long-term economic impacts on the region where having intervention projects. The use of only exponential function for impacts could be oversimplified the actual behavior of the impacts. Other functional form should be investigated to be used within the framework of the optimization model. Practical implications – The proposed hierarchy and the optimization model could be used in practical situation for determination of OISs for multiple objects within a road link. Originality/value – This paper contributes to the body of knowledge of stakeholder analysis in the field of infrastructure asset management. It also gives a guideline and tool for infrastructure administrators to select the OISs for their infrastructure network. [less ▲]

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See detailEvaluation of laser braze-welded dissimilar Al-Cu joints
Schmalen, Pascal Guy UL; Plapper, Peter UL

in Physics Procedia (2016), 83

The thermal joining of Aluminum and Copper is a promising technology towards automotive battery manufacturing. The dissimilar metals Al-Cu are difficult to weld due to their different physicochemical ... [more ▼]

The thermal joining of Aluminum and Copper is a promising technology towards automotive battery manufacturing. The dissimilar metals Al-Cu are difficult to weld due to their different physicochemical characteristics and the formation of intermetallic compounds (IMC), which have reduced mechanical and electric properties. There is a critical thickness of the IMCs where the favored mechanical properties of the base material can be preserved. The laser braze welding principle uses a position and power oscillated laser-beam to reduce the energy input and the intermixture of both materials and therefore achieves minimized IMCs thickness. The evaluation of the weld seam is important to improve the joint performance and enhance the welding process. This paper is focused on the characterization and quantification of the IMCs. Mechanical, electrical and metallurgical methods are presented and performed on Al1050 and SF-Cu joints and precise weld criteria are developed. [less ▲]

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See detailAn evaluation of low-cost consumer-grade UAS systems for 3D reality capture
Backes, Dietmar UL; Teasdale, Oliver; Eloff, Jacques

Poster (2016, September 22)

During the last years, small lightweight and low cost remotely piloted aerial systems (RPAS) commonly referred as Drones have rapidly developed into capable low-cost Unmanned Aerial Systems (UAS). Fuelled ... [more ▼]

During the last years, small lightweight and low cost remotely piloted aerial systems (RPAS) commonly referred as Drones have rapidly developed into capable low-cost Unmanned Aerial Systems (UAS). Fuelled by a vibrant community of scientists, professionals and hobby enthusiasts enabling technologies have matured quickly, and prices of consumer grade as well as semi-professional systems fell sharply. Especially multirotor vertical take-off and landing (VTOL) UAS have proven to be versatile and flexible platforms which can be equipped with a range of sensors capable of capturing aerial data for a variety of 2D and 3D mapping applications. Consumer grade, low weight systems as the DJI Phantom or 3DR Solo have a limited payload and can carry low weight action cameras like the GoPro Hero models which are capable of collecting video as well as still RGB and near-infrared imagery. Applying traditional Photogrammetric methods to imagery from low-cost UAS systems proved complex and impractical in the past. However modern the state-of-the-art structure from motion algorithms implemented in off the shelf software packages (sometimes referred as new Photogrammetry), cloud processing environments and available via open source libraries promise to generate dense 3D point clouds, textured models and orthomosaics in high quality and without much effort. How accurate and how reliable are data products generated from such systems? Expanding from a preliminary study (BACKES & TEASDALE 2015) we review the every progressing capabilities and features of COTS (commercial of the shelf) user and semi-professional UAS systems under the aspects of deployable sensors, ease of use, reliability as well as safety. We show the workflow from flight planning, data collection to dense pointclould matching using a range of software products. The resulting point clouds are evaluated and benchmarked using a highly accurate and dense reference data acquired via geodetic terrestrial survey and Laserscanning. The results of this evaluations allow conclusions on the current accuracy capabilities of this such low-cost systems. [less ▲]

Detailed reference viewed: 91 (22 UL)