Monitoring and Analysis of Galileo Services Performance using GalTeC

H. Su,W. Ehret,H. Blomenhofer,E. Blomenhofer 한국항해항만학회 2006 한국항해항만학회 학술대회논문집 Vol.1 No.-

The paper will give an overview of the mission of GalTeC and then concentrate on two main aspects. The first more detailed aspect, is the analysis of the key performance parameters for the Galileo system services and presenting a technical overview of methods and algorithms used. The second more detailed aspect, is the service volume prediction including service dimensioning using the Prediction tool. In order to monitor and validate the Galileo SIS performance for Open Service (OS) and Safety Of Life services (SOL) regarding the key performance parameters, different analyses in the SIS domain and User domain are considered. In the SIS domain, the validation of Signal-in-Space Accuracy SISA and Signal-in-Space Monitoring Accuracy SISMA is performed. For this purpose first of all an independent OD&TS and Integrity determination and processing software is developed to generate the key reference performance parameters named as SISRE (Signal In Space Reference Errors) and related over-bounding statistical information SISRA (Signal In Space Reference Accuracy) based on raw measurements from independent sites (e.g. IGS), Galileo Ground Sensor Stations (GSS) or an own regional monitoring network. Secondly, the differences of orbits and satellite clock corrections between Galileo broadcast ephemeris and the precise reference ephemeris generated by GalTeC will also be compared to check the SIS accuracy. Thirdly, in the user domain, SIS based navigation solution PVT on reference sites using Galileo broadcast ephemeris and the precise ephemeris generated by GalTeC are also used to check key performance parameters. In order to demonstrate the GalTeC performance and the methods mentioned above, the paper presents an initial test result using GPS raw data and GPS broadcast ephemeris. In the tests, some Galileo typical performance parameters are used for GPS system. For example, the maximum URA for one day for one GPS satellite from GPS broadcast ephemeris is used as substitution of SISA to check GPS ephemeris accuracy. Using GalTeC OD&TS and GPS raw data from IGS reference sites, a 10 cm-level of precise orbit determination can be reached. Based on these precise GPS orbits from GalTeC, monitoring and validation of GPS performance can be achieved with a high confidence level. It can be concluded that one of the GalTeC missions is to provide the capability to assess Galileo and general GNSS performance and prediction methods based on a regional and global monitoring networks. Some capability, of which first results are shown in the paper, will be demonstrated further during the planned Galileo IOV phase, the Full Galileo constellation phase and for the different services particularly the Open Services and the Safety Of Life services based on the Galileo Integrity concept.

In-situ surface analysis of AuPd(110) under elevated pressure of CO

Languille, M.A.,Ehret, E.,Lee, H.C.,Jeong, C.K.,Toyoshima, R.,Kondoh, H.,Mase, K.,Jugnet, Y.,Bertolini, J.C.,Aires, F.J.C.S.,Mun, B.S. Elsevier Science Publishers 2016 CATALYSIS TODAY - Vol.260 No.-

<P>With the combination of various in-situ surface science tools, surface chemical and structural properties of bimetallic AuPd(1 1 0) alloys are characterized under elevated CO pressure. Under 1 Torr of CO gas pressure, STM images show the formation of nano-sized surface rice-grains along the index direction of [1-10] while PM-IRRAS shows new CO vibrational band. This new vibrational band of PM-IRRAS is confirmed as the CO molecules attached to atop site of Pd with the results of ambient pressure XPS. In the case of adsorption of CO on AuPd(1 1 0) alloys, the so-called 'pressure gap' exists and the surface morphology and its chemical states change at elevated pressure conditions. (C) 2015 Elsevier B.V. All rights reserved.</P>

Evaluation of removal forces of implant-supported zirconia copings depending on abutment geometry, luting agent and cleaning method during re-cementation

Rodiger, Matthias,Rinke, Sven,Ehret-Kleinau, Fenja,Pohlmeyer, Franziska,Lange, Katharina,Burgers, Ralf,Gersdorff, Nikolaus The Korean Academy of Prosthodonitics 2014 The Journal of Advanced Prosthodontics Vol.6 No.3

PURPOSE. To evaluate the effects of different abutment geometries in combination with varying luting agents and the effectiveness of different cleaning methods (prior to re-cementation) regarding the retentiveness of zirconia copings on implants. MATERIALS AND METHODS. Implants were embedded in resin blocks. Three groups of titanium abutments (pre-fabricated, height: 7.5 mm, taper: $5.7^{\circ}$; customized-long, height: 6.79 mm, taper: $4.8^{\circ}$; customized-short, height: 4.31 mm, taper: $4.8^{\circ}$) were used for luting of CAD/CAM-fabricated zirconia copings with a semi-permanent (Telio CS) and a provisional cement (TempBond NE). Retention forces were evaluated using a universal testing machine. Furthermore, the influence of cleaning methods (manually, manually in combination with ultrasonic bath or sandblasting) prior to re-cementation with a provisional cement (TempBond NE) was investigated with the pre-fabricated titanium abutments (height: 7.5 mm, taper: $5.7^{\circ}$) and SEM-analysis of inner surfaces of the copings was performed. Significant differences were determined via two-way ANOVA. RESULTS. Significant interactions between abutment geometry and luting agent were observed. TempBond NE showed the highest level of retentiveness on customized-long abutments, but was negatively affected by other abutment geometries. In contrast, luting with Telio CS demonstrated consistent results irrespective of the varying abutment geometries. Manual cleaning in combination with an ultrasonic bath was the only cleaning method tested prior to re-cementation that revealed retentiveness levels not inferior to primary cementation. CONCLUSION. No superiority for one of the two cements could be demonstrated because their influences on retentive strength are also depending on abutment geometry. Only manual cleaning in combination with an ultrasonic bath offers retentiveness levels after re-cementation comparable to those of primary luting.

Evaluation of Industry 4.0 Data formats for Digital Twin of Optical Components

Arno Schmetz,Tae Hun Lee,Maximilian Hoeren,Marvin Berger,Susanne Ehret,Daniel Zontar,Soo-Hong Min,Sung-Hoon Ahn,Christian Brecher 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.3

A wide range of software and hardware components are present in today’s production systems and plants using a variety of interfaces and data formats for information exchange on diff erent levels of the system. To increase the traceability, the lifecycle management and providing a single point of source of component-specifi c data, the Digital Twin technology is proposed, linking diff erent data sets tailored to the requirements of diff erent kind of users (e.g., machines, technicians, logistics, manufacturing execution systems). The data exchange between entities in the manufacturing network relies on machine-readable, fl exible and self-describing data formats. When implementing or integrating diff erent components into complex systems, the interoperability challenge is a major concern to address by the system designers and becomes a central task for the creation and integration of Digital Twin technology. In this paper, we evaluate diff erent formats that are used in real environments and create a requirements framework for an ideal format for exchanging fl exible and self-describing data in context of optical components manufacturing process and their special requirements.

Evaluation of removal forces of implant-supported zirconia copings depending on abutment geometry, luting agent and cleaning method during re-cementation

Franziska Pohlmeyer,Katharina Lange,Ralf Burger Nikolaus Gersdorff,Fenja Ehret-Kleinau,Sven Rinke,Matthias ROdiger 대한치과보철학회 2014 The Journal of Advanced Prosthodontics Vol.6 No.3

PURPOSE To evaluate the effects of different abutment geometries in combination with varying luting agents and the effectiveness of different cleaning methods (prior to re-cementation) regarding the retentiveness of zirconia copings on implants. MATERIALS AND METHODS Implants were embedded in resin blocks. Three groups of titanium abutments (pre-fabricated, height: 7.5 mm, taper: 5.7°; customized-long, height: 6.79 mm, taper: 4.8°; customized-short, height: 4.31 mm, taper: 4.8°) were used for luting of CAD/CAM-fabricated zirconia copings with a semi-permanent (Telio CS) and a provisional cement (TempBond NE). Retention forces were evaluated using a universal testing machine. Furthermore, the influence of cleaning methods (manually, manually in combination with ultrasonic bath or sandblasting) prior to re-cementation with a provisional cement (TempBond NE) was investigated with the pre-fabricated titanium abutments (height: 7.5 mm, taper: 5.7°) and SEM-analysis of inner surfaces of the copings was performed. Significant differences were determined via two-way ANOVA. RESULTS Significant interactions between abutment geometry and luting agent were observed. TempBond NE showed the highest level of retentiveness on customized-long abutments, but was negatively affected by other abutment geometries. In contrast, luting with Telio CS demonstrated consistent results irrespective of the varying abutment geometries. Manual cleaning in combination with an ultrasonic bath was the only cleaning method tested prior to re-cementation that revealed retentiveness levels not inferior to primary cementation. CONCLUSION No superiority for one of the two cements could be demonstrated because their influences on retentive strength are also depending on abutment geometry. Only manual cleaning in combination with an ultrasonic bath offers retentiveness levels after re-cementation comparable to those of primary luting.